Endometriosis affects nearly 10 % of reproductive-age women and is characterized by the growth of endometrial-like tissues outside the uterus. This disease poses significant diagnostic and therapeutic challenges due to its unknown origins and complex pathophysiology. Our study investigates how epithelial-mesenchymal transition (EMT) contributes to the dysregulation of estradiol metabolism by suppressing hydroxysteroid 17β dehydrogenase 2 (HSD17B2) expression in endometriotic epithelial cells. We used Gene Set Variation Analysis (GSVA) on public microarray data to correlate EMT scores with HSD17B2 levels. This approach revealed a significant correlation, showing that EMT is linked to reduced HSD17B2 expression in endometriotic tissues. Furthermore, our qPCR and immunoblotting results showed that TGF-β-induced EMT significantly reduced HSD17B2 expression in human endometriotic 12Z epithelial cells. Additionally, our data showed that Snail, an EMT-related transcription factor, acts on the E-box motif in the HSD17B2 promoter to suppress transcription. Our findings show that EMT is associated with decreased HSD17B2 expression in endometriotic tissues. This downregulation disrupts estradiol metabolism, possibly contributing to endometriosis pathogenesis. Our study offers critical insights into the molecular mechanisms of endometriosis and suggests that targeting EMT, especially the TGF-β/Snail axis, could provide a new therapeutic approach.

Several studies have linked chemerin/chemokine-like receptor 1 (CMKLR1) to inflammation, leukocyte recruitment, and obesity. Reduced cellular activation may reduce inflammation in adipose tissues. High-throughput screening identified a novel antagonist (VU0514009), which was optimized to compound 16 as a full and competitive antagonist (IC50 = 37 μM). Mutagenesis studies elucidated relevant interactions of compound 16 at CMKLR1 residues Y6.51 and L7.35 as well as F7.31, S7.32, and T7.39 forming the binding pocket. Based on active CMKLR1/chemerin-9 structures and the inactive AlphaFold model, in silico docking was performed in the inactive model, with compound 16 most likely binding orthosterically. Considering the sequence similarity of CMKLR1 and GPR1, compound 16 was docked to GPR1, indicating a similar binding. At GPR1, compound 16 showed a slightly lower effect on chemerin-9-mediated arrestin recruitment and internalization.

Conventional therapies for metastatic cancers have limited efficacy. Recently, cancer therapies targeting noncancerous cells in tumor microenvironments have shown improved clinical outcomes in patients. However, further advances in our understanding of the metastatic tumor microenvironment are required to improve treatment outcomes. Adipocytes are distributed throughout the body, and as a part of the metastatic tumor microenvironment, they interact with cancer cells in almost all organs. Adipocytes secrete various factors that are reported to exert clinical effects on cancer progression, including engraftment, survival, and expansion at the metastatic sites. However, only a few studies have comprehensively examined their impact on cancer cells. In this review, we examined the impact of adipocytes on cancer by describing the adipocyte-secreted factors that are involved in controlling metastatic cancer, focusing on adipokines, such as adiponectin, leptin, visfatin, chemerin, resistin, apelin, and omentin. Adipocyte-secreted factors promote cancer metastasis and contribute to various biological functions of cancer cells, including migration, invasion, proliferation, immune evasion, and drug resistance at the metastatic sites. We propose the establishment and expansion of "adipo-oncology" as a research field to enhance the comprehensive understanding of the role of adipocytes in metastatic cancers and the development of more robust metastatic cancer treatments.

Digestive system infiltrating endometriosis (DSIE) is an uncommon form of endometriosis in the digestive system. DSIE often occurs in the intestines (especially the sigmoid rectum), liver, gallbladder and pancreas. Clinically, DSIE presents with the same symptoms as endometriosis, including cyclic pain, bleeding and infertility, in addition to specific biliary/intestinal obstruction and gastrointestinal bleeding. Compared to general endometriosis, DSIE has unique biological behaviour and pathophysiological mechanisms. Most DSIEs are deep invasive endometrioses, characterized by metastasis to the lymph nodes and lymphatic vessels, angiogenesis, peripheral nerve recruitment, fibrosis and invasion of surrounding tissues. DSIE-related peripheral angiogenesis is divided into three patterns: angiogenesis, vasculogenesis and inosculation. These patterns are regulated by interactions between multiple hypoxia-hormone cytokines. The nerve growth factors regulate the extensive neurofibril recruitment in DSIE lesions, which accounts for severe symptoms of deep pain. They are also associated with fibrosis and the aggressiveness of DSIE. Cyclic changes in DSIE lesions, recurrent inflammation and oxidative stress promote repeated tissue injury and repair (ReTIAR) mechanisms in the lesions, accelerating fibril formation and cancer-related mutations. Similar to malignant tumours, DSIE can also exhibit aggressiveness derived from collective cell migration mediated by E-cadherin and N-cadherin. This often makes DSIE misdiagnosed as a malignant tumour of the digestive system in clinical practice. In addition to surgery, novel treatments are urgently required to effectively eradicate this lesion.