Moreover, inhibition of RRM2 dampened the activation of phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signaling by decreasing phosphorylated-AKT and downstream matrix metalloproteinases-2 expression. Intriguingly, reactivation of the PI3K/AKT pathway with its agonist insulin-like growth factor-1 reversed the adverse effects of RRM2 suppression on cancer cell invasion, migration and VEGF expression. Together, these findings suggest that RRM2 may act as a pro-metastatic factor to facilitate breast cancer metastasis by evoking cell invasion, migration and VEGF expression through the PI3K/AKT signaling pathway. This study may provide an attractive target for metastatic intervention in breast cancer. Copyright © 2020, Spandidos Publications.The present retrospective study aimed to investigate the expression of semaphorin-4C (Sema4C) in epithelial ovarian cancer (EOC), and to determine the association between Sema4C expression and patient clinicopathological characteristics. Sema4C mRNA expression was detected by reverse transcription-quantitative polymerase chain reaction in the tissues of 74 cases of EOC, 20 cases of ovarian epithelial benign tumor, 20 cases of ovarian borderline epithelial tumor and 15 cases of normal ovarian tissue. Immunohistochemistry was used to detect the expression and localization of Sema4C. The association between Sema4C expression level and patients clinicopathological characteristics was determined by χ2 test. The results demonstrated that Sema4C expression level in ovarian epithelial carcinoma tissues was significantly higher compared with that in benign tumors, borderline epithelial tumors and normal ovarian tissues (P less then 0.05). In addition, Sema4C expression in ovarian cancer tissues was significantly associated with the clinical and pathological stages of tumors (P less then 0.05). In conclusion, the present study demonstrated that Sema4C expression was upregulated in EOC. Copyright © 2020, Spandidos Publications.Cervical Cancer is one of the leading causes of cancer-associated mortality in women. The present study aimed to identify key genes and pathways involved in cervical cancer (CC) progression, via a comprehensive bioinformatics analysis. The GSE63514 dataset from the Gene Expression Omnibus database was analyzed for hub genes and cancer progression was divided into four phases (phases I-IV). Pathway enrichment, protein-protein interaction (PPI) and pathway crosstalk analyses were performed, to identify key genes and pathways using a criterion nodal degree ≥5. Gene pathway analysis was determined by mapping the key genes into the key pathways. https://www.selleckchem.com/products/blu-222.html Co-expression between key genes and their effect on overall survival (OS) time was assessed using The Cancer Genome Atlas database. A total of 3,446 differentially expressed genes with 107 hub genes were identified within the four phases. A total of 14 key genes with 11 key pathways were obtained, following extraction of ≥5 degree nodes from the PPI and pathway crosstalk ner research. Copyright © Yi et al.N6-methyladenosine (m6A) RNA methylation, which is related to cancer initiation and progression, is dynamically regulated by the m6A RNA methylation regulators (including 'writers', 'erasers' and 'readers'). However, the prognostic value of m6A RNA methylation regulators involved in hepatocellular carcinoma (HCC) carcinogenesis and progression remains to be elucidated. The aim of the present study was to determine the prognostic score in predicting the prognosis of HCC patients based on these regulators. In The Cancer Genome Atlas, most of the 13 major m6A RNA methylation regulators were found to be differentially expressed between HCC and normal samples (P less then 0.001). In addition, two subgroups (clusters 1/2) had also been identified by applying consensus clustering in the m6A RNA methylation regulators. As compared with the cluster 1 subgroup, the cluster 2 subgroup was correlated with a poorer prognosis, as shown by the Kaplan-Meier method (P=6.197e-4). A risk signature was constructed based on these findings using six m6A RNA methylation regulators, which could not only predict the clinicopathological features of HCCs, but also serve as an independent prognostic marker, as shown by Cox regression analysis (hazard ratio=1.219, 95% confidence interval 1.143-1.299; P less then 0.001). Data from the International Cancer Genome Consortium were used for external validation. In addition, gene set enrichment analysis identified several pathways that m6A RNA methylation regulators were closely associated with. In conclusion, the m6A RNA methylation regulators are the crucial participants in the malignant progression of HCCs, which are potentially useful for prognosis stratification and therapeutic strategy development for HCC. Copyright © Li et al.MicroRNA (miR)-21 is known to act as an oncogene in cervical cancer by promoting cell proliferation and migration; however, the underlying molecular mechanisms have remained to be fully elucidated. The present study revealed that the gene expression levels of miR-21 and epithelial-mesenchymal transition (EMT)-associated transcription factor Zinc finger E-box-binding homeobox 1 (ZEB1), in cervical cancer and lymphatic metastatic carcinoma tissues were significantly higher than those in normal tissues (P less then 0.05). Furthermore, the gene expression levels of miR-21 and ZEB1 were positively associated with muscular infiltration depth, parametrical invasion and lymph node metastasis in patients with cervical cancer. Immunohistochemistry assays indicated that the expression levels of ZEB1 and the mesenchymal cell marker Vimentin in cervical cancer tissues were significantly higher than those in normal cervical tissues (P less then 0.05). Overexpression of miR-21 in HeLa and SiHa cells caused the upregulation of the mesenchymal cell markers Vimentin and N-cadherin, and downregulation of the epithelial cell marker E-cadherin at the proteins level. In addition, overexpression of miR-21 enhanced the invasiveness of HeLa and SiHa cells. These results demonstrated that miR-21 was upregulated in cervical cancer tissues and promoted cell metastasis through modulating EMT. A better understanding of the role of miR-21 and EMT may lead to the development of more effective therapies for patients with cervical cancer. Copyright © Tang et al.