In the 21st century, thanks to advances in biotechnology and developing pharmaceutical technology, significant progress is being made in effective drug design. Drug targeting aims to ensure that the drug acts only in the pathological area; it is defined as the ability to accumulate selectively and quantitatively in the target tissue or organ, regardless of the chemical structure of the active drug substance and the method of administration. With drug targeting, conventional, biotechnological and gene-derived drugs target the body's organs, tissues, and cells that can be selectively transported to specific regions. These systems serve as drug carriers and regulate the timing of release. Despite having many advantageous features, these systems have limitations in thoroughly treating complex diseases such as cancer. Therefore, combining these systems with nanoparticle technologies is imperative to treat cancer at both local and systemic levels effectively. The nanocarrier-based drug delivery method involves encapsulating target-specific drug molecules into polymeric or vesicular systems. Various drug delivery systems (DDS) were investigated and discussed in this review article. The first part discussed active and passive delivery systems, hydrogels, thermoplastics, microdevices and transdermal-based drug delivery systems. The second part discussed drug carrier systems in nanobiotechnology (carbon nanotubes, nanoparticles, coated, pegylated, solid lipid nanoparticles and smart polymeric nanogels). In the third part, drug targeting advantages were discussed, and finally, market research of commercial drugs used in cancer nanotechnological approaches was included.

Atypical cyclins have recently emerged as a new subfamily of cyclins characterized by common structural features and interactor pattern. Interestingly, atypical cyclins are phylogenetically close to canonical cyclins, which have well-established roles in cell cycle regulation and cancer. Therefore, although the function of atypical cyclins is still poorly characterized, it seems likely that they are involved in cancer pathogenesis as well. Here, we coupled gene expression and prognostic significance analysis to bibliographic search in order to provide new insights into the role of atypical cyclins in cancer. The information gathered suggests that atypical cyclins intervene in critical processes to sustain cancer growth and have potential to become novel prognostic markers and drug targets in cancer.

Protein-protein interactions (PPIs) represent promising drug targets of broad-spectrum therapeutic interests due to their critical implications in both health and disease circumstances. Hence, they are widely accepted as the Holy Grail of drug development. Historically, PPIs were rendered "undruggable" for their large, flat, and pocket-less structures. Current attempts to drug these "intractable" targets include orthosteric and allosteric methodologies. Previous efforts employing orthosteric approaches like protein therapeutics and orthosteric small molecules frequently suffered from poor performance caused by the difficulties in directly targeting PPI interfaces. As structural biology progresses rapidly, allosteric modulators, which direct to the allosteric regulatory sites remote to the PPI surfaces, have gradually established as a potential solution. Allosteric pockets are topologically distal from the PPI orthosteric sites, and their ligands do not need to compete with the PPI partners, which helps to improve the physiochemical and pharmacological properties of allosteric PPI modulators. Thus, exploiting allostery to tailor PPIs is regarded as a tempting strategy in future PPI drug discovery. Here, we provide a comprehensive review of our representative achievements along the way we utilize allosteric effects to tame the difficult PPI systems into druggable targets. Importantly, we provide an in-depth mechanistic analysis of this success, which will be instructive to future related lead optimizations and drug design. Finally, we discuss the current challenges in allosteric PPI drug discovery. Their solutions as well as future perspectives are also presented.

Cyclin-dependent kinase 2 (CDK2) drives the progression of cells into the S- and M-phases of the cell cycle. CDK2 activity is largely dispensable for normal development, but it is critically associated with tumor growth in multiple cancer types. Although the role of CDK2 in tumorigenesis has been controversial, emerging evidence proposes that selective CDK2 inhibition may provide a therapeutic benefit against certain tumors, and it continues to appeal as a strategy to exploit in anticancer drug development. Several small-molecule CDK2 inhibitors have progressed to the clinical trials. However, a CDK2-selective inhibitor is yet to be discovered. Here, we discuss the latest understandings of the role of CDK2 in normal and cancer cells, review the core pharmacophores used to target CDK2, and outline strategies for the rational design of CDK2 inhibitors. We attempt to provide an outlook on how CDK2-selective inhibitors may open new avenues for cancer therapy.

7-hydroxy-5,4'-dimethoxy-2-arylbenzofuran (Ary) is purified from Livistona. It has been demonstrated to have anticancer activity to various tumors in including cervical cancer, but its mechanism is still unclear. In the present, we show that Ary induces cervical cancer cells apoptosis through mitochondria degradation and mediates cervical cancer cell arrest. Further, Ary-inducing cell cycle G1/S-phase arrest is associated with increased cyclin A2 and cyclin dependent kinase 2 (Cdk2) proteins. Knockdown of cyclin A2 using small interfering RNA (siRNA), and inhibiting Cdk2 activity with flavopiridol, strikingly reduced G1/S-phase arrest. Moreover, Ary sustainedly induced phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). And ERK1/2 phosphorylation inhibition using specific inhibitor U0126 effectively suppressed cyclin A2 expression, and reduced G1/S-phase arrest induced by Ary. All the experiments in vitro and in vivo verified that Ary has an anticancer effect on cervical cancer. These data provide novel evidences that Ary induces cervical cancer cells apoptosis through mitochondria degradation and cell G1/S-phase arrest. These findings also suggest that ERK-mediated Cdk2/cyclin A signaling pathway is involved in Ary-induced G1/S-phase arrest.

Pelargonidin is an anthocyanidin isolated from plant resources. It shows strong cytotoxicity toward various cancer cell lines, even though the carcinogenesis-modulating pathway of pelargonidin is not yet known. One of our previous reports showed that pelargonidin arrests the cell cycle and induces apoptosis in HT29 cells. Flowcytometry and immunoblot analysis confirmed that pelargonidin specifically inhibits the activation of CDK1 and blocks the G2-M transition of the cell cycle. In addition, DNA fragmentation was observed along with induction of cytochrome c release-mediated apoptosis. Hence, the aim of the present study was to investigate the molecular mechanism of pelargonidin's action on cell cycle regulators CDK1, CDK4, and CDK6 as well as the substrate-binding domain of DNMT1 and DNMT3A, which regulate the epigenetic signals related to DNA methylation. The results of docking analysis, binding free energy calculation, and molecular dynamics simulation correlated with the experimental results, and pelargonidin showed a specific interaction with CDK1. In this context, pelargonidin may also inhibit the recognition of DNA and catalytic binding by DNMT1 and DNMT3A. The HOMO-LUMO analysis mapped the functional groups of pelargonidin. Prediction of pharmacological descriptors suggested that pelargonidin can serve as a multitarget inhibitor for cancer treatment.

Colorectal cancer accounts for a significant proportion of cancer deaths worldwide. The need to develop more chemotherapeutic agents to combat this disease is critical. Cyclin dependent kinases (CDKs), along with its binding partner cyclins, serve to control the growth of cells through the cell cycle. A new class of drugs, termed CDK inhibitors, has been studied in preclinical and now clinical trials. These inhibitors are believed to act as an anti-cancer drug by blocking CDKs to block the uncontrolled cellular proliferation that is hallmark of cancers like colorectal cancer. CDK article provides overview of the emerging drug class of CDK inhibitors and provides a list of ones that are currently in clinical trials.

Serine/threonine-specific cyclin-dependent kinases (CDKs) are key regulatory elements in eukaryotic cell cycle progression, and the dysregulation of CDKs has been implicated in cancers. Therefore, CDKs have been identified as anti-cancer targets for the development of small-molecule drugs. In this Letter, virtual screening and biological evaluation were performed to identify novel lead structures that allosterically disrupt the interaction between CDK2 and cyclin A3, which are directed toward a noncatalytic binding pocket of CDK2. Ultimately, B2 was identified as exhibiting superior CDK2/cyclin A3 inhibition activity. In addition, our results indicated that B2 exhibited antiproliferative activities against a broad spectrum of human cancer cell lines. Significantly, B2 certainly interrupted the interaction between CDK2 and cyclin A3 and exhibited a concentration-dependent trend. In summary, our results suggest that B2 is the first effective allosteric chemical small-molecule CDK2 inhibitor to be discovered, and further lead optimization may result in a series of novel anti-CDK2 agents.