Current Cancer Drug Targets - Volume 23, Issue 6, 2023

Ovarian cancer has become the largest cause of gynaecological cancer-related mortality. It is typically diagnosed at a late stage and has no effective screening strategy. Ovarian cancer is a highly heterogeneous disease that can be subdivided into several molecular subsets. As a result of a greater understanding of molecular pathways involved in carcinogenesis and tumor growth, targeted agents have been approved or are in several stages of development. Poly(ADP-ribose) polymerase (PARP) inhibitors and the anti-vascular endothelial growth factor (VEGF)-A antibodies are two types of approved and most effective targeted drugs for ovarian cancer at present. With the success of bevacizumab, tyrosine kinase inhibitors which could target alternate angiogenic pathways are being studied. Furthermore, many treatments targeting the PI3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways, are being developed or are already in clinical studies. MicroRNAs have also become novel biomarkers for the therapy and clinical diagnosis of ovarian cancer. This manuscript reviews the molecular, preclinical and clinical evidence supporting the targeting of growth-dependent pathways in ovarian cancer and assesses current data related to targeted treatments beyond PARP inhibitors.

Background: Hepatocarcinoma is the third leading cause of cancer-related deaths around the world. Recently, some studies have reported that Epigallocatechin-3-gallate (EGCG) may have the anti-cancer potential. However, the affection and putative mechanisms of cytotoxicity induced by EGCG in HepG2 cells remain unknown. Based on the above, the present study evaluated the effect of EGCG on the cytotoxic and anti-cancer mechanisms of HepG2 cells. Methods: The effect of EGCG on the apoptosis of Hep-G2 cells and its mechanism were studied by cell counting kit-8, mitochondrial membrane potential assay with JC-1, Annexin V-FITC apoptosis detection, cell cycle, and apoptosis analysis, one step TUNEL apoptosis assay, caspase 3 activity assay, caspase 9 activity Assay, Reactive Oxygen Species assay, and Western blot. Results: EGCG-induced HepG2 cell apoptosis was confirmed by accumulation of the sub-G1 cells population, translocation of phosphatidylserine, depletion of mitochondrial membrane potential, DNA fragmentation, caspase-3 activation, caspase-9 activation, and poly (ADP-ribose) polymerase cleavage. Furthermore, EGCG enhanced cytotoxic effects on HepG2 cells and triggered intracellular reactive oxygen species; the signaling pathways of AKT, JNK, and p53 were activated to advance cell apoptosis. Conclusion: The results reveal that EGCG may provide useful information on EGCG-induced HepG2 cell apoptosis and be an appropriate candidate for cancer chemotherapy.

Aim: This study aimed to investigate the biological functions of miRNAs in hepatobiliary tumors as the focus of targeted therapy research. Background: Hepatobiliary tumors are among the leading causes of cancer-related deaths worldwide. Many microRNAs (miRNAs) play an important regulatory role in tumor progression. Our study aims to explore some biologically functional miRNAs from different datasets of hepatobiliary tumors for disease diagnosis or treatment. Objective: In this study, we tried to filter out differentially expressed miRNAs in different tumor datasets from the GEO database. Methods: In this study, we first perform analyses in different GEO data sets. After taking the intersection, the initial scope is limited to several differential RNAs. Then, combined with the existing research results from Kaplan-Meier survival analysis and literature, the candidate molecule was finally identified to be studied. Furthermore, the biological characteristics analysis of the candidate molecule was performed on the basis of Cancermirnome online tool, including expression levels in tumors, KEGG and GO analysis, ROC analysis, and target gene prediction. Furthermore, the effect of the candidate molecule on the biological functions of liver cancer was verified by In Vitroassay. Results: The preliminary analysis of bioinformatics shows that 16 differentially expressed miRNAs may play an important role in HCC or ICC. Ultimately, we identified miRNA-99a-5p as the only molecule to study. The results showed that miRNA-99a-5p is abnormally expressed in many tumors, and in liver cancer, its level of expression in tumor tissue is significantly lower than that in normal tissue. Then, the KEGG and GO analysis found that it functions in multiple pathways. At the same time, the ROC analysis found that it showed great potential for prognostic prediction in HCC and we also predicted that RUNDC3B is the most likely target to which it binds. Finally, the experimental results of overexpression and knockdown confirmed that miRNA-99a-5p could inhibit cell proliferation in HCC, which also suggested that it may be an important tumor suppressor in HCC. Conclusion: MiRNA-99a-5p was negatively correlated with HCC progression and could act as a novel therapeutic target for HCC.

Background: Thyroid carcinoma (TC) is a common malignant tumor in human and its incidence has been increasing in recent years. Studies have shown that receptor type protein tyrosine phosphatase epsilon (PTPRE) is a key regulator of tumorigenesis in cancer progression, but its role in TC has not been revealed. Objective: Here, in this work, we explored the essential role of PTPRE in TC progression. Methods: The expression of PTPRE in TC clinical samples and cell lines was detected by RT-qPCR and Western blot. Cell proliferation was measured by MTT and cell cycle analysis. Cell migration, invasion and epithelial-mesenchymal transition (EMT) were analyzed by wound healing, transwell, and immunofluorescent staining assays. AKT and ERK1/2 signaling pathway related protein level was analyzed by Western blot. Results: PTPRE was highly expressed in TC clinical samples and cell lines, especially anaplastic thyroid carcinoma (ATC). High level of PTPRE was associated with tumor size and TNM stage. Upregulated PTPRE promoted cell proliferation, and enhanced the migration, invasion and EMT of TC cells, whereas the knockdown of PTPRE suppressed these behaviors. Importantly, we confirmed that the AKT and ERK1/2 signaling pathways were activated by PTPRE, reflected by the enhanced protein level of phosphorylated AKT and ERK1/2. Conclusion: Accordingly, we indicated that PTPRE plays an oncogenic role in TC progression via activating the AKT and ERK1/2 signaling pathway. These findings indicated that modulation of PTPRE expression may as a potential strategy to interfere with the progression of TC.

Purpose: The study aimed to assess the effect of p-ATR inhibitor VE-822 in the combination chemotherapy with cisplatin of head and neck squamous cell carcinoma and to explore the possible mechanism. Methods: The DNA damage levels were determined by comet assay and western blot experiments in cisplatin-resistant and sensitive cell lines. The IC50 value changes after combination treatment with VE-822 in cisplatin sensitive and resistant cell lines were detected by the CCK-8 test. The effects of VE-822 combined with cisplatin on proliferation ability, colony formation ability, migration ability, cell apoptosis and cell cycle changes were observed in vitro. In vivoI, the combination treatment effect was verified in the subcutaneous xenograft models of nude mice. Besides, the mechanism of VE-822 assisting cisplatin in chemotherapy was explored by comet assay, western blotting and immunohistochemical experiments. Results: The increased expression of the p-ATR protein was related to the DNA damage repair pathway in head and neck squamous cell carcinoma cisplatin-resistant cells. VE-822 inhibited cell proliferation, colony formation and migration abilities and improved the cisplatin chemotherapeutic effects in subcutaneous xenograft models of nude mice by inhibiting the p-ATR expression and blocking DNA damage repair pathway. Conclusions: The p-ATR expression increased in head and neck squamous cell carcinoma cisplatinresistant cells. VE-822 significantly enhanced the therapeutic effect in cisplatin resistant head and neck squamous cell carcinoma by inhibiting p-ATR expression in vivoand in vitro.

Background: Protein kinase, membrane-associated tyrosine/threonine 1 (PKMYT1) contributes to the proliferative, migratory, invasive and colony-forming capabilities of oncocytes. Dysregulated expression of PKMYT1 is associated with numerous malignancies. However, at present, the functional role of PKMYT1 in osteosarcoma is still not clarified. Objective: The present study, therefore, aimed to investigate the prognostic value of PKMYT1 in osteosarcoma, and to explore the underlying molecular mechanism(s). Methods: To meet this end, the expression level of PKMYT1 in osteosarcoma was measured by immunohistochemical analysis. The prognostic value of PKMYT1 in osteosarcoma was analyzed on the basis of R2: Genomics Analysis and Visualization Platform. The functional role of PKMYT1 was subsequently investigated in MG63 cells by knocking down PKMYT1 expression vialentivirus encoding shRNA. MTT assay, scratch-wound and Transwell assays were then used to determine whether PKMYT1 fulfills a role in the proliferative and invasive capabilities of the MG63 cells. Subsequently, the role of PKMYT1 in the apoptosis of the cells was assessed using western blot and immunofluorescence analyses. Finally, to determine whether PKMYT1 exerts its role through the NF-ΚB pathway, fibroblast-stimulating lipopeptide-1 (FSL-1) was used as an NF-ΚB activator. Results: Compared with normal tissues, osteosarcoma tissues showed a significantly increased level of PKMYT1 expression. The clinical survival analysis indicated that patients with high PKMYT1 expression were associated with lower probabilities of overall survival and metastasis-free survival compared with those with low PKMYT1 expression levels. Knockdown of PKMYT1 inhibited the migratory and invasive capabilities of the MG63 cells, and also facilitated their apoptosis. Moreover, the knockdown of PKMYT1 restrained the NF-ΚB pathway in MG63 cells, whereas activating the NF- ΚB pathway ameliorated the effects of silencing PKMYT1 on MG63 cells, suggesting that PKMYT1 functions viathe NF-ΚB pathway in MG63 cells. Conclusion: Taken together, the results of the present study have shown that a high expression level of PKMYT1 is associated with poor prognosis of osteosarcoma, and that PKMYT1 is able to aggravate the malignant progression of MG63 cells vianegatively regulating the NF-ΚB pathway, suggesting that PKMYT1 may be a potential molecular therapeutic target for the treatment of osteosarcoma.