To investigate the role of CXCR4 in response to teriparatide (TPTD) treatment in osteoblasts and osteoclasts.

Primary murine and human osteoblasts and osteoclasts, MC3T3 cell lines, and hMSC-TERT4 cell lines were treated with TPTD and/or AMD3100, a pharmacological inhibitor of CXCR4. Changes in gene expression, osteoblast viability, mobility, mineralization capacity, and alkaline phosphatase activity were investigated. Osteoclastogenesis and cell fusion were also assessed in response to both treatments.

TPTD increased messenger RNA levels of CXCR4 in all stages of both murine and human osteoblast differentiation. Mineralization analysis showed that CXCR4 was involved in bone matrix formation in response to TPTD. Alkaline phosphatase activity was also impaired by CXCR4 inhibition at early stages of osteoblast differentiation, while it was promoted at late stages, suggesting that CXCR4 could produce a delay in osteoblast maturation. Moreover, we also found a direct activation of osteoclastogenesis after TPTD treatment in murine and human osteoclasts. This process seems to involve CXCR4 activity, since AMD3100-induced CXCR4 inhibition led to a reduction in both murine and human osteoclastogenesis. This process, however, could not be prevented by TPTD treatment.

Our results suggest that CXCR4 is a responsive gene to TPTD treatment, involved in the regulation of osteoblast and osteoclast generation and function. Further in vivo studies are required to confirm this role, and to determine whether pharmacological strategies targeting CXCR4 could potentially improve the treatment outcome for osteoporotic patients.

The therapeutic efficacy of immune checkpoint blockade (ICB) is critically compromised by inadequate T lymphocyte infiltration, low T cell-induced pro-inflammatory responses, and the accumulation of immunosuppressive cells within the tumor microenvironment (TME). In this work, a chimeric peptide-engineered immunomodulatory nanomedicine (designated as CXNP-CeBM) is developed for photodynamic amplified ICB therapy against breast cancer. CXNP-CeBM is composed of a CXCR4-targeting peptide ((C16)2-KLGASWHRPDK) loaded with the photosensitizer of Ce6 and the PD-1/PD-L1 inhibitor of BMS8. CXNP-CeBM specifically recognizes CXCR4 on breast cancer, thus suppressing CXCR4-mediated signaling pathways and enhancing the intracellular delivery of therapeutic agents. The photodynamic therapy (PDT) of CXNP-CeBM damages primary tumor cells to initiate immunogenic cell death (ICD), leading to the release of high mobility group box 1 (HMGB1) and the exposure of calreticulin (CRT). Simultaneously, the interruption of CXCR4 signaling reduces tumor fibrosis, promotes T-cell infiltration, and decreases the number of immunosuppressive cells, thereby enhancing the immunotherapeutic effect of ICB. Treatment with CXNP-CeBM would activate systemic anti-tumor immunity, leading to effective inhibition of both primary and lung metastatic tumors, while maintaining low systemic toxicity. This work provides a reliable strategy for the delivery of multi-synergistic agents, effectively activating breast cancer immunity through a multifaceted mechanism. STATEMENT OF SIGNIFICANCE: Although immune checkpoint blockade (ICB) has shown great potential for malignant tumor therapy, its efficacy is compromised by immunosuppressive microenvironments. Herein, a CXCR4-targeted immunomodulatory nanomedicine (CXNP-CeBM) was constructed for photodynamic amplified ICB therapy of breast cancer. CXNP-CeBM could selectively deliver photosensitizers and PD-1/PD-L1 inhibitors to breast cancer cells that overexpressed the chemokine receptor CXCR4, while interrupting CXCR4 signaling to reduce tumor fibrosis, promote T-cell infiltration, and decrease the number of immunosuppressive cells. Moreover, CXNP-CeBM induced photodynamic therapy to trigger immunogenic cell death while downregulating the PD-L1 level to destroy immune evasion mechanisms, thus activating immunological cascades to treat both primary and lung metastatic tumors. This study provided a multi-synergistic strategy for breast cancer immunotherapy through a multifaceted mechanism.

Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment (TME) and play a crucial role in tumor progression. The biological properties of tumors, such as drug resistance, vascularization, immunosuppression, and metastasis are closely associated with CAFs. During tumor development, CAFs contribute to tumor progression by remodeling the extracellular matrix (ECM), inhibiting immune cell function, promoting angiogenesis, and facilitating tumor cell growth, invasion, and metastasis. Studies have shown that CAFs can promote endothelial cell proliferation by directly secreting cytokines such as vascular endothelial growth factor (VEGF) and fibroblast Growth Factor (FGF), as well as through exosomes. CAFs also secrete the chemokine stromal cell-derived factor 1 (SDF-1) to recruit endothelial progenitor cells (EPCs) into the peripheral blood and guide their migration to the tumor periphery. Additionally, CAFs can induce tumor cells to transform into "endothelial cells" that participate in vascular wall formation. However, the precise mechanisms remain to be further investigated. Due to their widespread presence in various solid tumors and their tumor-promoting function, CAFs are emerging as therapeutic targets. In this review, we summarize the specific mechanisms through which CAFs promote angiogenesis and outline current therapeutic strategies targeting CAF-induced vascularization, ongoing clinical trials targeting CAFs, and discuss potential future treatment approaches. We hope this will contribute to the advancement of CAF-targeted tumor treatment strategies.

Oral cancer remains a significant public health concern, with many patients diagnosed at advanced stages and facing poor prognoses. Despite advances in cancer research, diagnosis has seen only limited improvements, with biopsies still being the primary reliable method. This systematic review investigates the role of chemokines as potential biomarkers for early detection, prognosis, and metastasis in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs). Through an extensive literature search of MEDLINE, EMBASE, PubMed, and Scopus, 3350 articles were initially identified. After eliminating duplicates and screening for eligibility, 50 high-quality studies were included, offering a comprehensive overview of chemokine research in OSCC and OPMDs. Key findings indicate that CCR7 shows significant promise as a diagnostic, prognostic, and metastatic marker, although its function in precancerous conditions remains inadequately understood. CXCL10 and CCL22 were also highlighted for their strong prognostic and metastatic relevance, while CXCR4 and CXCL12 were identified as critical indicators of OSCC metastasis. Other chemokines, such as CXCR2, CCR4, XCR1, CXCL13, and CCL2 can aid OSCC differentiation and staging. However, the review emphasises the limitations of small patient cohorts and the lack of longitudinal research, stressing the need for further studies. Additionally, there is a pressing gap in research addressing chemokines as biomarkers for OPMDs. Rigorous validation is crucial to establish these biomarkers' reliability and clinical utility across various stages of oral cancer development.

The only subtype of breast cancer (BC) without specific therapy is triple-negative breast cancer (TNBC), which represents 15-20% of incidence cases of BC. TNBC encompasses transformed and nonmalignant cells, including cancer-associated fibroblasts (CAF), endothelial vasculature, and tumor-infiltrating cells. These nonmalignant cells, soluble factors (e.g., cytokines), and the extracellular matrix (ECM) form the tumor microenvironment (TME). The TME is made up of these nonmalignant cells, ECM, and soluble components, including cytokines. Direct cell-to-cell contact and soluble substances like cytokines (e.g., chemokines) may facilitate interaction between cancer cells and the surrounding TME. Through growth-promoting cytokines, TME not only enables the development of cancer but also confers therapy resistance. New treatment targets will probably be suggested by comprehending the processes behind tumor development and progression as well as the functions of chemokines in TNBC. In this light, several investigations have shown the pivotal function of the C-X-C motif chemokine ligand 12 (CXCL12 or SDF-1) axis and chemokine receptor type 4 (CXCR4) in the pathophysiology of TNBC. This review provides an overview of the CXCR4/CXCL12 axis' function in TNBC development, metastasis, angiogenesis, and treatment resistance. A synopsis of current literature on targeting the CXCR4/CXCL12 axis for treating and managing TNBC has also been provided.

The metastatic cascade is a complicated process where cancer cells travel across multiple organs distant from their primary site of onset. Despite the wide acceptance of the 'seed and soil' theory, mechanisms driving metastasis organotropism remain mystery. Using breast cancer of different subtypes as the disease model, we characterized the 'metastatic profile of cancer cells' and the 'redox status of the organ microenvironment' as the primary determinants of cancer metastasis organotropism. Mechanically, we identified a positive correlation between cancer metabolic plasticity and stemness, and proposed oxidative stress as the selection power of cancer cells succeeding the metastasis cascade. Therapeutically, we proposed the use of pro-oxidative therapeutics in ablating cancer cells taking advantages of this fragile moment during metastasis. We comprehensively reviewed current pro-oxidative strategies for treating cancers that cover the first line chemo- and radio-therapies, approaches relying on naturally existing power including magnetic field, electric field, light and sound, nanoparticle-based anti-cancer composites obtained through artificial design, as well as cold atmospheric plasma as an innovative pro-oxidative multi-modal modality. We discussed possible combinations of pro-oxidative approaches with existing therapeutics in oncology prior to the forecast of future research directions. This paper identified the fundamental mechanics driving metastasis organotropism and proposed intervention strategies accordingly. Insights provided here may offer clues for the design of innovative solutions that may open a new paradigm for cancer treatment.

The immunosuppressive microenvironment plays a crucial role in driving and accelerating tumor metastasis. S100A8/A9, produced by myeloid-derived suppressor cells, is a potential therapeutic target for metastatic cancer due to its role in promoting premetastatic niche formation. Previous studies have revealed that the S100A9-targeted peptide (H6, MEWSLEKGYTIK) fused to the Fc region of mouse IgG2b antibodies exhibits antitumor effects; however, the mechanism remains unclear. Here, dual-function peptide nanofibers (H6-Q11) were constructed, consisting of peptide H6 and self-assembly peptide (Q11, QQKFQFQFEQQ), which achieved high avidity for S100A9. In vivo studies showed that H6-Q11 nanofibers significantly prolonged lung retention and inhibited pulmonary metastasis from melanoma and breast cancer without obvious toxicity. Immunological analyses indicated that treatment with H6-Q11 nanofibers decreased the infiltration of immunosuppressive cells while promoting the recruitment of immune effector cells to the lungs, potentially correlated with disturbances of S100A8/A9-NCF1 signaling in the tumor microenvironment. Our findings support a potential clinical application of S100A9-targeted peptide nanofibers as candidate nanomedicine for inhibiting tumor metastasis.

[68Ga]PentixaFor detects C-X-C chemokine receptor type 4 (CXCR4) overexpression in various malignancies, such as multiple myeloma and non-Hodgkin lymphomas, as well as in endocrine and inflammatory disorders. This study aimed to develop an Al18F-labeled radiotracer derived from LY2510924 for CXCR4-targeted imaging, leveraging the physical and logistical advantages of fluorine-18.

We designed a CXCR4-specific radioprobe, [18F]AlF-NOTA-SC, based on LY2510924 by incorporating a triglutamate linker and NOTA chelator to enable Al18F-labeling. The in vitro CXCR4 affinity was assessed using cell-based binding assays. Subsequently, in vivo pharmacokinetics and tumor uptake of [18F]AlF-NOTA-SC were assessed in naïve mice and mice with xenografts derived from U87.CD4/U87.CD4.CXCR4 and MM.1 S cells. Finally, biodistribution was determined in a non-human primate using PET-MR.

Compared to Ga-PentixaFor, AlF-NOTA-SC demonstrated similar in vitro affinity for human CXCR4. [18F]AlF-NOTA-SC was produced with a decay-corrected radiochemical yield of 21.0 ± 7.1% and an apparent molar activity of 16.4 ± 3.6 GBq/µmol. In [18F]AlF-NOTA-SC binding assays on U87.CD4.CXCR4 cells, the total bound fraction was 7.1 ± 0.5% (58% blocking by AMD3100). In naïve mice, the radiotracer did not accumulate in any organs; however, it showed a significant CXCR4-specific uptake in xenografted tumors (SUVmeanU87.CD4 = 0.04 ± 0.00 (n = 3); SUVmeanU87.CD4.CXCR4 = 3.04 ± 0.65 (n = 3); SUVmeanMM.1 S = 1.95 ± 0.11 (n = 3)). In a non-human primate, [18F]AlF-NOTA-SC accumulated in CXCR4 expressing organs, such as the spleen and bone marrow.

[18F]AlF-NOTA-SC exhibited CXCR4-specific uptake in vitro and in vivo, with fast and persistent tumor accumulation, making it a strong candidate for clinical translation as an 18F-alternative to [68Ga]PentixaFor.

Natural killer (NK) cells are prototypic cytotoxic innate lymphocytes that can kill target cells, such as tumor cells, in the absence of antigen-restriction. Peripheral NK cells exhibit a high degree of heterogeneity. Here, we set out to broadly assess intrinsic modulators of NK cell degranulation in an unbiased manner. We stimulated human primary blood-borne NK cells pre-treated with different cytokine regimens with the HCT116 human colon cancer cell line and used detection of lysosome-associated membrane glycoprotein 1 (LAMP1) as an identifier of rapid NK cell degranulation. RNA sequencing of FACS-sorted LAMP1hi NK cells showed CXCR4 and S1PR5 were top down-regulated genes. Using compounds that modulate activity of CXCR4 and S1P receptor family members S1P1 and S1P5, we confirmed they play an important immunosuppressive role in NK cell cytotoxicity. Mechanistically, engagement of CXCR4 and S1P1/5 receptors triggered phosphorylation of p42 and Ca2+ influx. CXCR4 activation promoted S1P5 upregulation and vice versa, and joint activation of both receptors amplified the defect NK cell degranulation. Intriguingly, in tumor samples the expression of both receptors and the synthesis of their ligands themselves appear to be coordinately regulated. Together, these data suggest that specifically and simultaneously targeting CXCR4 and S1P5 activity in the tumor microenvironment (TME) could be a beneficial strategy to unleash full cytotoxic potential of cytotoxic NK effector cells in the tumor.

Cancer, a leading cause of premature death, arises from genetic and epigenetic mutations that transform normal cells into tumor cells, enabling them to proliferate, evade cell death, and stimulate angiogenesis. Recent evidence indicates that chemokines are essential in tumor development, activating receptors that promote proliferation, invasion, and metastasis. The CXCR4/CXCL12 signaling pathway is gaining attention as a promising target for cancer therapy. CXCR4, a chemokine receptor, is often overexpressed in various types of cancer, including kidney, lung, brain, prostate, breast, pancreas, ovarian, and melanomas. When it binds to its endogenous ligand, CXCL12, it promotes cell survival, proliferation, and migration, crucial mechanisms for the retention of hematopoietic stem cells in the bone marrow and the movement of lymphocytes. The extensive expression of CXCR4 in cancer, coupled with the constant presence of CXCL12 in various organs, drives the activation of this axis, which in turn facilitates angiogenesis, tumor progression, and metastasis. Given the detrimental role of the CXCR4/CXCL12 axis, the search for drugs acting selectively against this protein represents an open challenge. This review aims to summarize the recent advancements in the design and development of CXCR4 antagonists as potential anticancer agents.

We investigated the CXCL12/CXCR4 signaling pathway as a regulator of adipose-derived stem cell (ADSC) self-assembling toroidal constructs using collagen hydrogels. ADSCs formed toroid rings when cultured on hydrogel surfaces but failed to do so when mixed within the matrix. Gene expression profiling revealed significant upregulation of the CXCL12/CXCR4 pathway in toroid-forming conditions, supported by immunofluorescence studies that confirmed CXCL12 presence in toroids but not in mixed-in cultures. Early toroid formation was marked by the emergence of CXCL12 expression, correlating with cell migration. Targeted inhibition experiments identified the PI3K pathway as a critical regulator, delaying cell migration by ∼16 h, while N-Cadherin, Ras/Raf, and ERK1/2 inhibition either reduced or halted migration over extended periods. Through Western blot analysis, altered expression of α-Smooth muscle actin and focal adhesion kinase under PI3K inhibition was highlighted thus emphasizing their roles in toroid formation. Lastly, initial coculture studies with 4T1 breast cancer cells unexpectedly showed CXCL12 localization primarily in 4T1 cells within mixed toroids, suggesting modified chemotactic signaling. Our findings establish CXCL12/CXCR4 as crucial for ADSC toroid formation and reveal the pathway's complex involvement in cellular organization and migration, presenting a robust model for exploring cell-cell and cell-matrix interactions relevant to tissue engineering and cancer research.

The current study outlines a consistent and reproducible protocol for the routine clinical dose preparation of [68Ga]Ga-Pentixafor using the Eckert and Ziegler 'Modular-Lab Standard' non-cassette based automated module, that can be effectively used in the hospital radiopharmacy unit of a high volume nuclear medicine centre. The pre-clinical studies (including in-vitro cell line studies, in-vivo PET/CT imaging and pre-clinical dosimetry) were conducted to show the promising potential of the product for clinical use in targeting CXCR4 tumor overexpression. PET/CT image of SCID mouse bearing lymphoma xenograft tumor, at 2 h post-injection, clearly delineated the tumor. The pre-clinical dosimetry results show the suitability of the product for clinical use in patients. [68Ga]Ga-Pentixafor when administered to patients with primary aldosteronism exhibited distinct uptake in the adrenal nodules. The clinical PET/CT scan of the patients demonstrated the potential use of CXCR4 targeted imaging as a promising surgical decision-making tool for patients with primary aldosteronism.

➢ Skeletal stem cells (SSCs) continually replenish mature cell populations to support skeletal homeostasis.➢ SSCs repopulate by self-renewal, have multilineage potential, and are long-lived in vivo.➢ SSCs express specific combinations of cell surface markers that reflect their lineage identity.➢ SSCs adapt to their anatomic environment to support regional differences in skeletal behavior and pathology.

Cancer-associated fibroblasts (CAFs) secrete and synthesize fibroblast activation protein (FAP), which could promote proliferation and immunosuppression of multiple cancers including esophageal squamous cell carcinoma (ESCC). CXCL12/CXCR4 signaling could be revitalized by CAFs in cancer cells. Nevertheless, the significance of this interaction in ESCC has yet to be elucidated. Herein, we investigated whether FAP+ CAF cells could promote ESCC cells proliferation, migration and regulate immunity through the CXCL12/CXCR4 pathway in vitro and in vivo. The protein expression level of FSP1, FAP, CD8+ and Ki-67 in different sample was estimated by IHC and western blot. qPCR was used to quantify the mRNA level of FSP1, FAP, CD8+ and Ki-67 in different sample. The cell viability, proliferation, migration and invasion of different sample were evaluated by CCK-8, EdU staining, wound healing assay and Transwell assay, respectively. The ELISA was carried out to measure the protein level of IFN-γ, TNF-α, GZMB and IL-2. ESCC xenograft mice model was established to assess the impact of FAP+ CAF. FSP1, FAP, CD8+ and Ki-67 are greatly up-regulated in hESCC tissues. Through CXCL12/CXCR4 axis, FAP-positive CAF was capable of promoting the cell proliferation, migration and invasion of ESCC tumor cells and preventing the CD8+ T cells from secreting cytokine. Blocking this signaling with selective CXCR4 antagonist could counteract the effects caused by high-expression of FAP. FAP+ CAFs could inhibit the occurrence and development of tumors. These results indicated that FAP-positive CAF have an impact on cell proliferation migration and immunoregulation of ESCC through the CXCL12/CXCR4 axis.

Activation of the chemokine receptor CXCR4 by its chemokine ligand CXCL12 regulates diverse cellular processes. Previously reported crystal structures of CXCR4 revealed the architecture of an inactive, homodimeric receptor. However, many structural aspects of CXCR4 remain poorly understood. Here, we use cryo-electron microscopy to investigate various modes of human CXCR4 regulation. CXCL12 activates CXCR4 by inserting its N terminus deep into the CXCR4 orthosteric pocket. The binding of US Food and Drug Administration-approved antagonist AMD3100 is stabilized by electrostatic interactions with acidic residues in the seven-transmembrane-helix bundle. A potent antibody blocker, REGN7663, binds across the extracellular face of CXCR4 and inserts its complementarity-determining region H3 loop into the orthosteric pocket. Trimeric and tetrameric structures of CXCR4 reveal modes of G-protein-coupled receptor oligomerization. We show that CXCR4 adopts distinct subunit conformations in trimeric and tetrameric assemblies, highlighting how oligomerization could allosterically regulate chemokine receptor function.

The present study aimed to identify hub genes associated with the treatment and control of active and inactive Crohn's disease (CD).

Differentially expressed genes (DEGs) were identified in normal, active CD, and inactive CD samples from GSE95095 dataset. Intersection genes screened by Venn diagram in DEGs. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted on the intersection genes. The protein-protein interaction (PPI) network was used to screen of hub gene. The expression and mRNA levels of CXCL12 in CD and ROC curves in GSE95095 dataset. Signaling pathways of hub genes and their correlation with immune cells were analyzed by gene set enrichment analysis (GSEA), EPIC, and ESTIMATE, respectively. Finally, immunohistochemistry (IHC) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were used to detect the expression of the hub gene in normal, inactive, and active CD tissues.

In GSE95095 dataset, CXCL12 was identified as the most hub gene by limma analysis, Venn diagram and A protein-protein interaction (PPI) network. CXCL12 expression was highest in active CD (p < 0.001) followed by inactive CD (p < 0.01). Subsequently, it was validated through IHC and RT-PCR in normal intestinal mucosal, active CD, and inactive CD. CXCL12 was overexpressed in active and inactive CD (IHC: p < 0.001 and RT-PCR: p < 0.001, respectively). CXCL12 expression in active CD was determined via analysis with receiver operating characteristic (ROC) curves. The specificity and sensitivity were 0.875 and 0.625, respectively, the accuracy was 72.92%, the area under the curve (AUC) was 0.780, and the 95% confidence interval (CI) was in the range of 0.648-0.912. CXCL12 expression was closely correlated with various immune cells.

CXCL12 is overexpressed in active CD and is closely correlated with various immune cells. We propose that CXCL12 as a potential target genes for the treatment and management of both active and inactive CD.

NK cells are endowed with tumor killing ability, nevertheless most cancers impair NK cell functionality, and cell-based therapies have limited efficacy in solid tumors. How cancers render NK cell dysfunctional is unclear, and overcoming resistance is an important immune-therapeutic aim. Here, we identify autophagy as a central regulator of NK cell anti-tumor function. Analysis of differentially expressed genes in tumor-infiltrating versus non-tumor NK cells from our previously published scRNA-seq data of advanced human prostate cancer shows deregulation of the autophagic pathway in tumor-infiltrating NK cells. We confirm this by flow cytometry in patients and in diverse cancer models in mice. We further demonstrate that exposure of NK cells to cancer deregulates the autophagic process, decreases mitochondrial polarization and impairs effector functions. Mechanistically, CCAAT enhancer binding protein beta (C/EBPβ), downstream of CXCL12-CXCR4 interaction, acts as regulator of NK cell metabolism. Accordingly, inhibition of CXCR4 and C/EBPβ restores NK cell fitness. Finally, genetic and pharmacological activation of autophagy improves NK cell effector and cytotoxic functions, which enables tumour control by NK and CAR-NK cells. In conclusion, our study identifies autophagy as an intracellular checkpoint in NK cells and introduces autophagy regulation as an approach to strengthen NK-cell-based immunotherapies.

Gliomas account for 75 % of primary malignant CNS tumors. High-grade glioma (CNS WHO grades 3 and 4) have an unfavorable treatment response and poor outcome. CXCR4 is a G protein-coupled receptor that plays an important part in the signaling pathway between cancer cells and tumor microenvironment. CXCR4 overexpression has been shown in a variety of cancers. In this study, we evaluate the potential value of [68Ga]Ga-Pentixafor as a PET/CT CXCR4-probe for in vivo assessment of CXCR4 expression in patients with high-grade glioma and its correlation with tumor grade.

[68Ga]Ga-CXCR4 PET/CT was performed in the prospective single-center study in treatment-naïve biopsy-proven patients with high-grade glioma. The acquired images were analyzed qualitatively and semi-quantitatively.

A total of 26 patients (mean age: 53.3±14.4 years, 11 women, 15 men) were enrolled. CNS WHO grade 3 pathology was seen in 19 % (5/26) of the sample. The patient-based sensitivity of 68Ga-CXCR4 was 96.2 %. Overall, 28 pathologic lesions were detected, leading to a lesion-based sensitivity of 96.4 %. The median (IQR) SUVmax of grade 4 lesions was substantially greater than the grade 3(3.03(2.5-3.7) vs. 1.51(1.2-1.8), p = 0.0145).). The highest tracer activity of organs -beside bladder as the main excretion reservoir-was in lymphoid tissue of Waldeyer's ring (mean SUVmax: 7.41), and spleen (mean SUVmax: 6.62).

In conclusion, this new application for [68Ga]Ga-Pentixafor PET tracer exhibits excellent visual and semi-quantitative diagnostic properties. Further studies are warranted.

Lymph node metastasis, the initial step in distant metastasis, represents a primary contributor to mortality in patients diagnosed with oral squamous cell carcinoma (OSCC). However, the underlying mechanisms of lymph node metastasis in OSCC remain incompletely understood. Here, the transcriptomes of 56 383 single cells derived from paired tissues of six OSCC patients are analyzed. This study founds that CXCR4+ epithelial cells, identified as highly malignant disseminated tumor cells (DTCs), exhibited a propensity for lymph node metastasis. Importantly, a distinct subset of tumor-associated macrophages (TAMs) characterized by exclusive expression of phosphoprotein 1 (SPP1) is discovered. These TAMs may remodel the metastatic lymph node microenvironment by potentially activating fibroblasts and promoting T cell exhaustion through SPP1-CD44 and CD155-CD226 ligand-receptor interactions, thereby facilitating colonization and proliferation of disseminated tumor cells. The research advanced the mechanistic understanding of metastatic tumor microenvironment (TME) and provided a foundation for the development of personalized treatments for OSCC patients with metastasis.

Ischemic stroke and cerebral amyloid angiopathy (CAA) pose significant challenges in an aging population, particularly in post-stroke recovery. Using the 5xFAD mouse model, we explore the relationship between CAA, ischemic stroke, and tissue recovery. We hypothesize that amyloid-beta accumulation worsens stroke outcomes by inducing blood-brain barrier (BBB) dysfunction, leading to impaired neurogenesis. Our findings show that CAA exacerbates stroke outcomes, with mice exhibiting constricted BBB microvessels, reduced cerebral blood flow, and impaired tissue recovery. Transcriptional analysis shows that endothelial cells and neural progenitor cells (NPCs) in the hippocampus exhibit differential gene expression in response to CAA and stroke, specifically targeting the phosphatidylinositol 3-kinase (PI3K) pathway. In vitro experiments with human NPCs validate these findings, showing that disruption of the CXCL12-PIK3C2A-CREB3L2 axis impairs neurogenesis. Notably, PI3K pathway activation restores neurogenesis, highlighting a potential therapeutic approach. These results suggest that CAA combined with stroke induces microvascular dysfunction and aberrant neurogenesis through this specific pathway.

Liver metastasis is a major cause of morbidity and mortality in patients with colorectal cancer. A better understanding of the biological mechanisms underlying liver tropism and metastasis in colorectal cancer could help to identify improved prevention and treatment strategies. In this study, we performed genome-wide CRISPR loss-of-function screening in a mouse colorectal cancer model and identified deficiency of AFDN, a protein involved in establishing and maintaining cell-cell contacts, as a driver of liver metastasis. Elevated AFDN expression was correlated with prolonged survival in patients with colorectal cancer. AFDN-deficient colorectal cancer cells preferentially metastasized to the liver but not in the lungs. AFDN loss in colorectal cancer cells at the primary site promoted cancer cell migration and invasion by disrupting tight intercellular junctions. Additionally, CXCR4 expression was increased in AFDN-deficient colorectal cancer cells via the JAK-STAT signaling pathway, which reduced the motility of AFDN-deficient colorectal cancer cells and facilitated their colonization of the liver. Collectively, these data shed light on the mechanism by which AFDN deficiency promotes liver tropism in metastatic colorectal cancer. Significance: A CRISPR screen reveals AFDN loss as a mediator of liver tropism in colorectal cancer metastasis by decreasing tight junctions in the primary tumor and increasing interactions between cancer cells and hepatocytes.

Kaposi sarcoma (KS) is defined by aberrant angiogenesis driven by Kaposi sarcoma herpesvirus (KSHV)-infected spindle cells with endothelial characteristics. KS research is hindered by rapid loss of KSHV infection upon explant culture of tumor cells. Here, we establish patient-derived KS xenografts (PDXs) upon orthotopic implantation of cutaneous KS biopsies in immunodeficient mice. KS tumors were maintained in 27/28 PDX until experimental endpoint, up to 272 days in the first passage of recipient mice. KSHV latency associated nuclear antigen (LANA)+ endothelial cell density increased by a mean 4.3-fold in 14/15 PDX analyzed by IHC at passage 1 compared to respective input biopsies, regardless of implantation variables and clinical features of patients. The Ki-67 proliferation marker colocalized with LANA more frequently in PDXs. Spatial transcriptome analysis revealed increased expression of viral transcripts from latent and lytic gene classes in the PDX. The expanded KSHV+ regions of the PDX maintained signature gene expression of KS tumors, with enrichment in pathways associated with angiogenesis and endothelium development. Cells with characteristics of tumor-associated fibroblasts derived from PDX were propagated for 15 passages. These fibroblast-like cells were permissive for de novo KSHV infection, and one lineage produced CXCL12, a cancer-promoting chemokine. Spatial analysis revealed that fibroblasts are a likely source of CXCL12 signaling to CXCR4 that was upregulated in KS regions. The reproducible expansion of KSHV-infected endothelial cells in PDX from multiple donors and recapitulation of a KS tumor gene signature supports the application of patient-derived KS mouse models for studies of pathogenesis and novel therapies.

Background: This study aimed to investigate the effect of cytoreductive nephrectomy (CN) on the survival outcomes of nivolumab used as a subsequent therapy after the failure of at least one anti-vascular endothelial growth factor (VEGF) agent in patients with metastatic clear-cell renal-cell carcinoma (ccRCC). Methods: We included 106 de novo metastatic ccRCC patients who received nivolumab after progression on at least one anti-VEGF agent. Multivariate Cox regression analysis was performed to investigate the factors affecting survival in patients receiving nivolumab. Results: Of the 106 de novo metastatic ccRCC patients, 83 (78.3%) underwent CN. There were no statistical differences between the two groups in terms of age, gender, Eastern Cooperative Oncology Group (ECOG) score, tumor size, International Metastatic RCC Database Consortium (IMDC) risk group, number of previous treatment lines, first-line anti-VEGF therapy, or metastasis sites (p = 0.137, p = 0.608, p = 0.100, p = 0.376, p = 0.185, p = 0.776, p = 0.350, and p = 0.608, respectively). The patients who received nivolumab with CN had a longer time to treatment discontinuation (TTD) [14.5 months, 95% confidence interval (CI): 8.6-20.3] than did those without CN 6.7 months (95% CI: 3.9-9.5) (p = 0.001). The median overall survival (OS) was 22.7 months (95% CI: 16.1-29.4). The patients with CN had a median OS of 22.9 months (95% CI: 16.3-29.4), while those without CN had a median OS of 8.1 months (95% CI: 5.6-10.5) (p = 0.104). In the multivariate analysis, CN [hazard ratio (HR): 0.521; 95% CI: 0.297-0.916; p = 0.024] and the IMDC risk score (p = 0.011) were statistically significant factors affecting TTD; however, the IMDC risk score (p = 0.006) was the only significant factor for overall survival. Conclusions: Our study showed that the TTD of nivolumab was longer in metastatic ccRCC patients who underwent cytoreductive nephrectomy.

Currently, immune checkpoint inhibitors (ICIs) have changed the treatment paradigm for many malignant tumors. As the most common digestive tract malignancy, colorectal cancer (CRC) shows a good response to ICIs only in a small subset of patients with MSI-H/dMMR CRC. In contrast, patients with MSS/pMMR CRC show minimal response to ICIs. The results of the REGONIVO study suggest that targeting the tumor microenvironment (TME) to improve immunotherapy outcomes in MSS/pMMR CRC patients is a feasible strategy. Therefore, this article focuses on exploring the feasibility of targeting the TME to enhance immunotherapy outcomes in CRC, collecting recent basic research on targeting the TME to enhance immunotherapy outcomes in CRC and analyzing ongoing clinical trials to provide a theoretical basis and future research directions for improving immunotherapy outcomes in MSS/pMMR CRC.

Acute myeloid leukemia (AML) is a malignancy of immature myeloid blast cells with stem-like and chemoresistant cells being retained in the bone marrow through CXCL12-CXCR4 signaling. Current CXCR4 inhibitors mobilize AML cells into the bloodstream where they become more chemosensitive have failed to improve patient survival, likely reflecting persistent receptor localization on target cells. Here we characterize the signaling properties of CXCL12-locked dimer (CXCL12-LD), a bioengineered variant of the dimeric CXCL12 structure. CXCL12-LD binding resulted in lower levels of G protein, β-arrestin, and intracellular calcium mobilization, consistent with the locked dimer being a partial agonist of CXCR4. Further, CXCL12-LD failed to induce chemotaxis in AML cells. Despite these partial agonist properties, CXCL12-LD increased CXCR4 internalization compared to wildtype and locked-monomer forms of CXCL12. Analysis of a previously published AML transcriptomic data showed CXCR4 positive AML cells co-express genes involved in chemoresistance and maintenance of a blast-like state. The CXCL12-LD partial agonist effectively mobilized stem cells into the bloodstream in mice suggesting a potential role for their use in targeting CXCR4. Together, our results suggest that enhanced internalization by CXCL12-LD partial agonist signaling can avoid pharmacodynamic tolerance and may identify new avenues to better target GPCRs.

The most devastating feature of cancer cells is their ability to metastasize to distant sites in the body. HER2 + and TN breast cancers frequently metastasize to the brain and stay potentially dormant for years until favorable conditions support their proliferation. The sheltered and delicate nature of the brain prevents, however, early disease detection and effective delivery of therapeutic drugs. Moreover, the challenges associated with the acquisition of brain biopsies add compounding difficulties to exploring the mechanistic aspects of tumor development. To provide insights into the determinants of cancer cell behavior at the brain metastatic site, this study was aimed at exploring the early response of HER2 + breast cancer cells (SKBR3) to factors present in the brain perivascular niche. The neural microenvironment was simulated by using the secretome of a set of brain cells that come first in contact with the cancer cells upon crossing the blood brain barrier, i.e., endothelial cells, astrocytes, and microglia. Cytokine microarrays were used to investigate the secretome mediators of intercellular communication, and proteomic technologies for assessing the changes in the behavior of cancer cells upon exposure to the brain cell-secreted factors. The cytokines detected in the brain secretomes were supportive of inflammatory conditions, while the SKBR3 cells secreted numerous cancer-promoting growth factors that were either absent or present in lower abundance in the brain cell cultures, indicating that upon exposure the SKBR3 cells may have been deprived of favorable conditions for optimal growth. Altogether, the results suggest that the exposure of SKBR3 cells to the brain cell-secreted factors altered their growth potential and drove them toward a state of quiescence, with broader overall outcomes that affected cellular metabolism, adhesion and immune response processes. The findings of this study underscore the key role played by the neural niche in shaping the behavior of metastasized cancer cells, provide insights into the cellular cross-talk that may lead cancer cells into dormancy, and highlight novel opportunities for the development of metastatic breast cancer therapeutic strategies.

Uveal melanoma is the most common non-cutaneous melanoma and is an intraocular malignancy affecting nearly 7,000 individuals per year worldwide. Of these, approximately 50% will progress to metastatic disease for which there are currently no effective curative therapies. Despite advances in molecular profiling and metastatic stratification of uveal melanoma tumors, little is known regarding their underlying biology of metastasis. Our group has identified a disseminated neoplastic cell population characterized by co-expression of immune and melanoma proteins, circulating hybrid cells (hybrids), in patients with uveal melanoma. Compared to circulating tumor cells, which lack expression of immune proteins, hybrids are detected at an increased prevalence in peripheral blood and can be used as a non-invasive biomarker to predict metastatic progression.

To ascertain mechanisms underlying enhanced hybrid cell dissemination we identified hybrid cells within primary uveal melanoma tumors using single cell RNA sequencing (n = 8) and evaluated their gene expression and predicted ligand-receptor interactions in relation to other melanoma and immune cells within the primary tumor. We then verified expression of upregulated hybrid pathways within patient-matched tumor and peripheral blood hybrids (n = 4) using cyclic immunofluorescence and quantified their protein expression relative to other non-hybrid tumor and disseminated tumor cells.

Among the top upregulated genes and pathways in hybrid cells were those involved in enhanced cell motility and cytoskeletal rearrangement, immune evasion, and altered cellular metabolism. In patient-matched tumor and peripheral blood, we verified gene expression by examining concordant protein expression for each pathway category: TMSB10 (cell motility), CD74 (immune evasion) and GPX1 (metabolism). Both TMSB10 and GPX1 were expressed on significantly higher numbers of disseminated hybrid cells compared to circulating tumor cells, and CD74 and GPX1 were expressed on more disseminated hybrids than tumor-resident hybrids. Lastly, we identified that hybrid cells express ligand-receptor signaling pathways implicated in promoting metastasis including GAS6-AXL, CXCL12-CXCR4, LGALS9-P4HB and IGF1-IGFR1.

These findings highlight the importance of TMSB10, GPX1 and CD74 for successful hybrid cell dissemination and survival in circulation. Our results contribute to the understanding of uveal melanoma tumor progression and interactions between tumor cells and immune cells in the tumor microenvironment that may promote metastasis.

Chemokines are small, secreted cytokines crucial in the regulation of a variety of cell functions. The binding of chemokine C-X-C motif chemokine ligand 12 (CXCL12) (stromal cell-derived factor 1) to a G-protein-coupled receptor C-X-C chemokine receptor type 4 (CXCR4) triggers downstream signaling pathways with effects on cell survival, proliferation, chemotaxis, migration, and gene expression. Intensive and extensive investigations have provided evidence suggesting that the CXCL12-CXCR4 axis plays a pivotal role in tumor development, survival, angiogenesis, metastasis, as well as in creating tumor microenvironment, thus implying that this axis is a potential target for the development of cancer therapies. The structures of CXCL12 and CXCR4 have been resolved with experimental methods such as X-ray crystallography, NMR, or cryo-EM. Therefore, it is possible to apply structure-based computational approaches to discover, design, and modify therapeutic molecules for cancer treatments. Here, we summarize the current understanding of the roles played by the CXCL12-CXCR4 signaling axis in cellular functions linking to cancer progression and metastasis. This review also provides an introduction to protein structures of CXCL12 and CXCR4 and the application of computer simulation and analysis in understanding CXCR4 activation and antagonist binding. Furthermore, examples of strategies and current progress in CXCL12-CXCR4 axis-targeted development of therapeutic anticancer inhibitors are discussed.

Poor long-term survival in localized high-risk soft tissue sarcomas (STSs) of the extremities and trunk highlights the need to identify new prognostic factors. CXCR4 is a chemokine receptor involved in tumor progression, angiogenesis, and metastasis. The aim of this study was to evaluate the association between CXCR4 expression in tumor tissue and survival in STSs patients treated with neoadjuvant therapy. CXCR4 expression was retrospectively determined by immunohistochemical analysis in serial specimens including initial biopsies, tumors post-neoadjuvant treatment, and tumors after relapse. We found that a positive cytoplasmatic expression of CXCR4 in tumors after neoadjuvant treatment was a predictor of poor recurrence-free survival (RFS) (p = 0.003) and overall survival (p = 0.019) in synovial sarcomas. We also found that positive nuclear CXCR4 expression in the initial biopsies was associated with poor RFS (p = 0.022) in undifferentiated pleomorphic sarcomas. In conclusion, our study adds to the evidence that CXCR4 expression in tumor tissue is a promising prognostic factor for STSs.

Alpha-fetoprotein elevated gastric cancer (AFPGC) got growing interests for its aggressive nature and unfavorable prognosis. Here, a phase 1 dose escalation study was conducted to evaluate safety and efficacy of zimberelimab (GLS-010, anti-PD-1) plus lenvatinib and chemotherapy (XELOX) as the first-line treatment for AFPGC.

Histologically confirmed HER2-negative, advanced GC patients with elevated serum AFP level (≥ 20 ng/ml) were screened. Using a 3 + 3 dose escalation design, patients were administered varying doses of lenvatinib (12, 16, 20 mg) with GLS-010 and XELOX. The primary endpoints were safety and determination of recommended phase II dose (RP2D). Secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and disease control rate.

Nine patients were enrolled with no dose-limiting toxicities observed. Most frequent treatment-related AEs were fatigue (55.6%), hand-foot syndrome (55.6%) and rash (55.6%), and no grade ≥ 4 AEs were reported. All patients exhibited disease control with ORR reaching 33.3%. The median PFS and OS reached 7.67 months (95% CI 4.07-11.27) and 13.17 months (95% CI 2.78-23.56), respectively. Serum AFP level was found correlated with therapeutic responses. Further 16s rRNA sequencing analysis demonstrated altered gut microbiota with elevated abundance of Lachnospiraceae bacterium-GAM79 and Roseburia hominis A2-183.

GLS-010 plus lenvatinib and XELOX demonstrated a manageable safety profile with promising efficacy for AFPGC. With RP2D of lenvatinib determined as 16 mg, further expansion cohort is now ongoing. Translational investigation suggested that serum AFP can be indictive for therapeutic responses and certain microbiota species indicating favorable responses to immunotherapy was elevated after the combinational treatment.

Chemokine receptors are members of the G protein-coupled receptor superfamily. The C-X-C chemokine receptor type 4 (CXCR4), one of the most studied chemokine receptors, is widely expressed in hematopoietic and immune cell populations. It is involved in leukocyte trafficking in lymphoid organs and inflammatory sites through its interaction with its natural ligand CXCL12. CXCR4 assumes a pivotal role in B-cell development, ranging from early progenitors to the differentiation of antibody-secreting cells. This review emphasizes the significance of CXCR4 across the various stages of B-cell development, including central tolerance, and delves into the association between CXCR4 and B cell-mediated disorders, from immunodeficiencies such as WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome to autoimmune diseases such as systemic lupus erythematosus. The potential of CXCR4 as a therapeutic target is discussed, especially through the identification of novel molecules capable of modulating specific pockets of the CXCR4 molecule. These insights provide a basis for innovative therapeutic approaches in the field.

G protein-coupled receptors (GPCRs) are well-studied and the most traceable cell surface receptors for drug discovery. One of the intriguing members of this family is G protein-coupled receptors 35 (GPR35), which belongs to the class A rhodopsin-like family of GPCRs identified over two decades ago. GPR35 presents interesting features such as ubiquitous expression and distinct isoforms. Moreover, functional and genome-wide association studies on its widespread expression have linked GPR35 with pathophysiological disease progression. Various pieces of evidence have been accumulated regarding the independent or endogenous ligand-dependent role of GPR35 in cancer progression and metastasis. In the current scenario, the relationship of this versatile receptor and its putative endogenous ligands for the activation of oncogenic signal transduction pathways at the cellular level is an active area of research. These intriguing features offered by GPR35 make it an oncological target, justifying its uniqueness at the physiological and pathophysiological levels concerning other GPCRs. For pharmacologically targeting receptor-induced signaling, few potential competitive antagonists have been discovered that offer high selectivity at a human level. In addition to its fascinating features, targeting GPR35 at rodent and human orthologue levels is distinct, thus contributing to the sub-species selectivity. Strategies to modulate these issues will help us understand and truly target GPR35 at the therapeutic level. In this article, we have provided prospects on each topic mentioned above and suggestions to overcome the challenges. This review discusses the molecular mechanism and signal transduction pathways activated by endogenous ligands or spontaneous auto-activation of GPR35 that contributes towards disease progression. Furthermore, we have highlighted the GPR35 structure, ubiquitous expression, its role in immunomodulation, and at the pathophysiological level, especially in cancer, indicating its status as a versatile receptor. Subsequently, we discussed the various proposed ligands and their mechanism of interaction with GPR35. Additionally, we have summarized the GPR35 antagonist that provides insights into the opportunities for therapeutically targeting this receptor.

High precision, image-guided radiotherapy (RT) has increased the therapeutic ratio, enabling higher tumor and lower normal tissue doses, leading to improved patient outcomes. Nevertheless, some patients remain at risk of developing serious side effects.In many clinical situations, the radiation tolerance of normal tissues close to the target volume limits the dose that can safely be delivered and thus the potential for tumor control and cure. This is particularly so in patients being re-treated for tumor progression or a second primary tumor within a previous irradiated volume, scenarios that are becoming more frequent in clinical practice.Various normal tissue 'radioprotective' drugs with the potential to reduce side effects have been studied previously. Unfortunately, most have failed to impact clinical practice because of lack of therapeutic efficacy, concern about concurrent tumor protection or excessive drug-related toxicity. This review highlights the evidence indicating that targeting the CXCL12/CXCR4 pathway can mitigate acute and late RT-induced injury and reduce treatment side effects in a manner that overcomes these previous translational challenges. Pre-clinical studies involving a broad range of normal tissues commonly affected in clinical practice, including skin, lung, the gastrointestinal tract and brain, have shown that CXCL12 signalling is upregulated by RT and attracts CXCR4-expressing inflammatory cells that exacerbate acute tissue injury and late fibrosis. These studies also provide convincing evidence that inhibition of CXCL12/CXCR4 signalling during or after RT can reduce or prevent RT side effects, warranting further evaluation in clinical studies. Greater dialogue with the pharmaceutical industry is needed to prioritize the development and availability of CXCL12/CXCR4 inhibitors for future RT studies.

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.