MicroRNA-21 (miR-21) Post-Transcriptionally Downregulates Tumor Suppressor PDCD4 and Promotes Cell Transformation, Proliferation, and Metastasis in Renal Cell Carcinoma

Objectives: MiR-21 induces neoplastic transformation, cell proliferation, and metastasis and downregulates programmed cell death4 (PDCD4) in some cancers. The aim of this study was to investigate the roles and interactions of PDCD4 and miR-21 in human renal cell carcinoma (RCC). Materials and Methods: A total of 32 paired tumor and normal tissue specimens from RCC patients as well as three renal cancer cell lines (786-O, A498, caki-1) and one normal epithelial kidney cell line (HK-2) were studied. The expression levels of PDCD4 (protein and mRNA) and miR-21 were examined by Western blot analysis and by qRT-PCR and luciferase reporter assays. Furthermore, we transfected 786-O cells with pre-miR-21 (mimics) and anti-miR-21 (inhibitor) and then again analyzed the expression of PDCD4 protein and mRNA, and determined cell proliferation and transformation capabilities by EDU and soft agar colony formation assay. Results: MiR-21 expression was significantly upregulated in RCC, metastatic RCC specimens and renal cancer cell lines (A498, 786-O, caki-1) compared to normal non-metastatic RCC specimens and HK-2 cells (PPP>0.05). Moreover, we observed a significant reduction in PDCD4 protein levels in miR-21mimic-transfected cells, but a significant increase in miR-21inhibitor-transfected cells (PP>0.05). Furthermore, miR-21mimic-transfected cells exhibited increased cell proliferation and transformation capacity according to EDU analysis and soft agar formation assay, whereas miR-21inhibitor-transfected cells exhibited the opposite phenomenon(PConclusions: MiR-21 not only promoted cancer cell hyperplasia and contributed to tumor cell transformation and metastasis, but also post-transcriptionally downregulated PDCD4 protein expression. PDCD4 and miR-21 expression levels potentially play an important role in renal cell cancer

Effect of AQP9 Expression in Androgen-Independent Prostate Cancer Cell PC3

It is known that aquaporin 9 (AQP9) in the prostate was strictly upregulated by androgen and may represent a novel therapeutic target for several cancers, but whether AQP9 plays a role in the regulation of androgen-independent prostate cancer still remains unclear. In the present study, AQP9 was determined in prostate cancer and adjacent cancer tissues; AQP9-siRNA was applied to silencing AQP9 in androgen-independent prostate cancer cell PC3 cell line. Western blot and flow cytometry analysis were employed to detect changes in related-function of control and AQP9-siRNA groups. The results showed that AQP9 is significantly induced in cancer tissues than that in adjacent cancer tissues. Moreover, knockdown of AQP9 in PC3 androgen-independent prostate cancer cell prostate cancer cells increased inhibition rates of proliferation. In addition, knockdown of AQP9 resulted in a significant decrease in the expression of the Bcl-2 and with a notable increase in the expression of Bax and cleaved caspase 3, indicated that AQP9 knockdown promoted apoptosis in prostate cancer cells. From wound healing assay and matrigel invasion, we suggested that AQP9 expression affects the motility and invasiveness of prostate cancer cells. Moreover, In order to explore the pathway may be involved in AQP9-mediated motility and invasion of prostate cancer cells, the phosphorylation of ERK1/2 was significant suppressed in AQP9 siRNA-transfected cells compared with that in control cells, suggesting that AQP9 is involved in the activation of the ERK pathway in androgen-independent prostate cancer cells

KLF4, a miR-32-5p targeted gene, promotes cisplatin-induced apoptosis by upregulating BIK expression in prostate cancer

Abstract Background Chemotherapeutic insensitivity remains a big challenge in prostate cancer treatment. Recently, increasing evidence has indicated that KLF4 plays a key role in prostate cancer. However, the potential biological role of KLF4 in Chemotherapeutic insensitivity of prostate cancer is still unknown. Methods The role of KLF4 in cisplatin-induced apoptosis was detected by western blotting and a cell counting kit (CCK8). The potential molecular mechanism of KLF4 in regulating prostate cancer chemosensitivity was investigated by RNA sequencing analysis, q-RT-PCR, western blotting and chromatin immunoprecipitation (ChIP). The expression level of KLF4 mediated by miR-32-5p was confirmed by bioinformatic analysis and luciferase assays. Results Here, we found that KLF4 was induced by cisplatin in prostate cancer cells and that the increase in KLF4 promoted cell apoptosis. Further mechanistic studies revealed that KLF4 directly bound to the promoter of BIK, facilitating its transcription. Additionally, we also found that the gene encoding KLF4 was a direct target of miR-32-5p. The downregulation of miR-32-5p in response to cisplatin treatment promoted KLF4 expression, which resulted in a increase in the chemosensitivity of prostate cancer. Conclusion Thus, our data revealed that KLF4 is an essential regulator in cisplatin-induced apoptosis, and the miR-32-5p-KLF4-BIK signalling axis plays an important role in prostate cancer chemosensitivity

Is Overexpression of Ki-67 a Prognostic Biomarker of Upper Tract Urinary Carcinoma? A Retrospective Cohort Study and Meta-Analysis

Background: Upper tract urinary carcinoma (UTUC) is a relatively uncommon but aggressive disease. The Ki-67 antigen is a classic marker of cellular proliferation, but there is still controversy regarding the significance and importance of Ki-67 in tumor progression. Methods: In this study, we first detected Ki-67 expression in UTUC patients by immunohistochemistry (IHC). Subsequently, we quantitatively combined the results with those from the published literature in a meta-analysis after searching several databases. Results: IHC results demonstrated that patients with muscle-invasive tumors (T2-T4) had higher Ki-67 expression than those with non-muscle-invasive tumors (Tis-T1), suggesting that high Ki-67 expression may be associated with the aggressive form of UTUC. Kaplan-Meier curves showed that patients with high Ki-67 expression had significantly poorer cancer-specific survival (CSS) and disease-free survival (DFS). Furthermore, multivariate analysis suggested that Ki-67 expression was an independent prognostic factor for CSS (hazard ratio, HR=3.196) and DFS (HR=3.517) in UTUC patients. Then, a meta-analysis of the published literature investigating Ki-67 expression and its effects on UTUC prognosis was conducted. After searching the PubMed, Medline, Embase, Cochrane Library and Scopus databases, 12 articles met the eligibility criteria for this analysis. The eligible studies included a total of 1740 patients with a mean number of 82 patients per study (range, 38-475). The combined results showed that increased Ki-67 levels were associated with poor survival and disease progression, with a pooled HR estimate of 2.081 and 2.791, respectively. In subgroup analysis, the pooled HR was statistically significant for cancer-specific survival (HR=2.276), metastasis-free survival (HR=3.008) and disease-free survival (HR=6.336). Conclusions: In conclusion, high Ki-67 expression was associated with poor survival in patients with UTUC, as well as a high risk of disease progression, although these findings need to be interpreted with caution. Large-scale, adequately designed, prospective trials are needed to further confirm the value of Ki-67 in prognosis of UTUC patients