Cyclin dependent kinases as targets for cancer therapy

Design, synthesis and evaluation of structurally diverse ortho-acylphenol-diindolylmethane hybrids as anticancer agents

A highly efficient synthesis of structurally diverse ortho-acylphenol–diindolylmethane hybrids 3 using carboxylic acid-activated chromones as versatile synthetic building blocks is reported here for the first time, through 1,4-nucleophilic addition and followed by a decarboxylation and pyrone ring opening reaction process.

High expression of piwi-like RNA-mediated gene silencing 1 is associated with poor prognosis via regulating transforming growth factor-β receptors and cyclin-dependent kinases in breast cancer

Previous studies have demonstrated that abnormal expression levels of PIWI may serve a crucial role in tumorigenesis. However, the pathological role and its association with prognosis remains to be fully elucidated. In the present study, the expression levels of piwi‑like RNA‑mediated gene silencing 1 (HIWI) and piwi‑like RNA‑mediated gene silencing 2 (HILI) in breast cancer tissues were reported to be high. The high expression levels of HIWI are correlated with poor prognosis in detected patients. In addition, by overexpression and interference, it was demonstrated that HIWI promotes the activity of breast cancer cells while depression of HIWI may induce apoptosis of breast cancer cells. It was additionally identified that suppression of HIWI may arrest the cells at the G2/M stage. The expression levels of transforming growth factor‑β receptor (TβR)I, TβRII, cyclin‑dependent kinase (CDK)4, CDK6 and CDK8 were observed to be regulated by HIWI, which indicated a novel mechanism of HIWI in the regulation of breast cancer progression. The present study provides novel insight into the HIWI expression in breast cancer, providing a potential biomarker for assessment of prognosis and therapy of breast cancer.

Heat-shock protein 90 (Hsp90) as anticancer target for drug discovery: an ample computational perspective

There are over 100 different types of cancer, and each is classified based on the type of cell that is initially affected. If left untreated, cancer can result in serious health problems and eventually death. Recently, the paradigm of cancer chemotherapy has evolved to use a combination approach, which involves the use of multiple drugs each of which targets an individual protein. Inhibition of heat-shock protein 90 (Hsp90) is one of the novel key cancer targets. Because of its ability to target several signaling pathways, Hsp90 inhibition emerged as a useful strategy to treat a wide variety of cancers. Molecular modeling approaches and methodologies have become 'close counterparts' to experiments in drug design and discovery workflows. A wide range of molecular modeling approaches have been developed, each of which has different objectives and outcomes. In this review, we provide an up-to-date systematic overview on the different computational models implemented toward the design of Hsp90 inhibitors as anticancer agents. Although this is the main emphasis of this review, different topics such as background and current statistics of cancer, different anticancer targets including Hsp90, and the structure and function of Hsp90 from an experimental perspective, for example, X-ray and NMR, are also addressed in this report. To the best of our knowledge, this review is the first account, which comprehensively outlines various molecular modeling efforts directed toward identification of anticancer drugs targeting Hsp90. We believe that the information, methods, and perspectives highlighted in this report would assist researchers in the discovery of potential anticancer agents.

G1 arrest and caspase-mediated apoptosis in HL-60 cells by dichloromethane extract of Centrosema pubescens

Cell division and apoptosis are two crucial components of tumor biology and the importance of increased cell proliferation and reduced cell death have made them valid therapeutic targets. The plant kingdom is a relatively underexploited cache of novel drugs, and crude extracts of plants are known for their synergistic activity. The present study assessed the anti-proliferative activity of the medicinal plant Centrosema pubescens Benth. Centrosema pubescens dichloromethane extract (CPDE) inhibited the proliferation of HL-60 (promyelocytic acute leukaemia) cells with an IC₅₀ value of 5 μg/ml. Further studies also showed that CPDE induces growth arrest at the G1 phase and specifically down-regulates the expressions of cyclin E and CDK2 and up-regulates p27(CKI) levels. These events apparently lead to the induction of apoptosis, which was demonstrated qualitatively by a DNA fragmentation assay and propidium iodide staining. Quantitative assessment of the effective arrest of the cell cycle and of apoptosis was confirmed by flow cytometry. CPDE exhibited negligible cytotoxicity even at the highest dose tested (100 μg/ml) in both normal peripheral blood mononuclear cells and in an in vitro model (HL-60). Our results strongly suggest that CPDE arrests the cell cycle at the G1 phase and triggers apoptosis by caspase activation.