Speckle-type POZ protein could play a potential inhibitory role in human renal cell carcinoma.

BACKGROUND: Speckle-type POZ protein(SPOP), a substrate adaptor of Cul3 ubiquitin ligase, plays crucial roles in solid neoplasms by promoting the ubiquitination and degradation of substrates. Limited studies have shown that SPOP is overexpressed in human renal cell carcinoma (RCC) tissue. However, the exact role of SPOP in RCC remains unclear and needs to be further elucidated. The present study showed that SPOP was expressed at different levels in different RCC cell lines. The purpose of this study was to explore the roles of SPOP in the biological features of RCC cells and the expression levels of SPOP in human tissue microarray (TMA) and kidney tissues. METHODS: Here, SPOP was overexpressed by lentiviral vector transfection in ACHN and Caki-1 cells, and SPOP was knocked down in Caki-2 cells with similar transfection methods. The transfection efficiency was evaluated by quantitative PCR and western blotting analyses. The role of SPOP in the proliferation, migration, invasion and apoptosis of cell lines was determined by the MTT, wound-healing, transwell and flow cytometry assays. Moreover, the cells were treated with different drug concentrations in proliferation and apoptosis assays to investigate the effect of sunitinib and IFN-α2b on the proliferation and apoptosis of SPOP-overexpressing cells and SPOP-knockdown RCC cells. Finally, immunohistochemical staining of SPOP was performed in kidney tissues and TMAs, which included RCC tissues and corresponding adjacent normal tissues. RESULTS: Overexpression of SPOP inhibited cell proliferation, migration and invasion and increased cell apoptosis. Interestingly, sunitinib and IFN-α2b at several concentrations increased the proliferation inhibitory rate and total apoptosis rate of cells overexpressing SPOP. The findings of the present study showed that the SPOP protein was significantly expressed at low levels in most clear cell RCC (ccRCC) tissues and at relatively high levels in the majority of adjacent normal tissues and kidney tissues. Kaplan-Meier survival analysis showed that there was no statistically significant difference in cumulative survival based on the data of different SPOP expression levels in TMA and patients. CONCLUSIONS: In contrast to previous studies, our findings demonstrated that overexpression of SPOP might suppress the progression of RCC cells, which was supported by cell experiments and immunohistochemical staining. SPOP could be a potential tumour inhibitor in RCC.

High expression of TTC21A predicts unfavorable prognosis and immune infiltrates in clear cell renal cell carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC) is the most common pathological type of renal cell carcinoma. Tetratricopeptide repeat domain 21A (TTC21A), known as a component of intraflagellar transport complex A which is essential for the function of cilia, However, the role of TTC21A remains unclear in ccRCC. For the first time, we explore the role and potential mechanism of TTC21A in ccRCC based on multiple databases. Methods: TTC21A expression across all TCGA tumor was analyzed via Tumor Immune Estimation Resource (TIMER) site. The correlation between TTC21A and clinicopathologic characteristics of ccRCC was analyzed with TCGA database. The diagnostic and prognostic value of TTC21A was evaluated by receiver operation characteristic curve, Kaplan-Meier plotter and Cox regression respectively. Moreover, functional enrichment analysis of TTC21A and the co-expression genes were performed by Gene Set Enrichment Analysis. The correlation of TTC21A and immune infiltration were evaluated by single sample Gene Set Enrichment Analysis. Results: Pan-cancer analysis indicated that TTC21A was highly expressed in ccRCC and other cancer. In addition, elevated expression of TTC21A was associated with worse overall survival in ccRCC patients. Functional enrichment analysis showed that TTC21A and the co-expressed genes enriched in glucose metabolism and energy metabolism. Moreover, TTC21A expression was associated with infiltrating levels of dendritic cell, nature killer cell and other immune marker sets. Conclusion: The results of analysis indicate that expression of TTC21A is associated with poor prognosis and immune infiltrating in ccRCC, which suggested TTC21A might be used as a potential predictor and target of treatment in ccRCC.

Effect of AKT silence on malignant biological behavior of renal cell carcinoma cells.

BACKGROUND: As the most common malignant tumor of primary renal tumor, renal cell carcinoma (RCC) is the highly invasive disease with high mortality. AKT is a serine/threonine kinase that play a critical role in the phosphoinositide 3-kinase (PI3K) signaling pathway, and it is an attractive target for RCC treatment. The aim of present study was to investigate the effect of AKT silence on malignant behavior of renal cell carcinoma cells. METHODS: AKT expression was quantified by immunohistochemistry in tumor tissues and normal tissues. The human RCC cell lines Caki-2 cell were chosen for this study. The optimal silencing siRNA was subsequently selected by RT-qPCR and western blot. The effect of AKT silence on RCC cells was investigated by CCK8 assay, transwell assay, scratch test and flow cytometry. The AKT1 expression in human renal cell carcinoma tissue was detected by immunohistochemical staining. RESULTS: The AKT in Caki-2 cells was silenced successfully. The results shown AKT silence could inhibit cell proliferation, invasion, and, migration. In addition, AKT silence could promote Caki-2 cell apoptosis with prevention of RCC cells move from G1 phase to S phase. Immunohistochemical staining revealed significant difference of expression of AKT1 in RCC tissues and normal renal tissues. Taken together, AKT family members might involve in malignant growth of RCC, and might be a potential therapeutic target. CONCLUSION: Our data show that AKT silence inhibited cell proliferation, invasion, and, migration of Caki-2 cell, and promoted Caki-2 cell apoptosis. Moreover, AKT silence prevented RCC cells move from G1 phase to S phase. Therefore, AKT may act as an effective therapeutic target for RCC.

[Corrigendum] Screening of hub genes and evaluation of the growth regulatory role of CD44 in metastatic prostate cancer.

Subsequently to the publication of the above article, the authors have realized that they inadvertently included images of the same mice in Figs. 7A [the Negative Control (NC) experiment] and 8A [the 5B­3CT + Docetaxel (10 mg/kg) experiment]. After having consulted their original data, the authors have realized that these mice were correctly shown in the paper for the experiments portrayed in Fig. 7A; therefore, the corrected version of Fig. 8 is shown on the next page, showing the mice pertaining to the 5B­3CT + Docetaxel (10 mg/kg) experiment in Fig. 8A. The authors are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish a Corrigendum, and all the authors agree to this Corrigendum. Furthermore, they apologize to the readership for any inconvenience caused. [Oncology Reports 46: 196, 2021; DOI: 10.3892/or.2021.8147].

Screening of hub genes and evaluation of the growth regulatory role of CD44 in metastatic prostate cancer.

Prostate cancer (PCa) is the most common cancer type in men worldwide. Currently, the management of metastatic PCa (mPCa) remains a challenge to urologists. The analysis of hub genes and pathways may facilitate the understanding of the molecular mechanism of PCa. In the present study, to identify the hub genes in the mPCa, the three datasets GSE3325, GSE6919 and GSE38241 were downloaded from the platform of the Gene Expression Omnibus and function enrichment analysis of differentially expressed genes (DEGs) was performed. A total of 168 DEGs were obtained and the DEGs were significantly enriched in 'cell junction' and 'cell adhesion', among others. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that DEGs were enriched in three pathways including 'focal adhesion', 'renal cell carcinoma' and 'Hippo signaling pathway'. The results of the protein­protein interaction network revealed that the hub genes in mPCa were separately PTEN, Rac GTPase­activating protein 1, protein regulator of cytokinesis 1, PDZ binding kinase, centromere­associated protein E, NUF2 component of NDC80 kinetochore complex, TPX2 microtubule nucleation factor, SOX2, CD44 and ubiquitin­like with PHD and ring finger domains 1. As a hub gene, CD44 was differentially expressed in PCa, as determined by Oncomine analysis. Further experiments in vivo demonstrated that SB­3CT, a selective matrix metalloproteinase inhibitor that has been reported to block CD44 cleavage and inhibit the downstream signaling pathway, suppressed the tumorigenicity of PCa cells by decreasing the expression levels of pyruvate dehydrogenase kinase 1 and 6­phosphofructo­2­kinase/fructose­2,6­biphosphatase 4. Moreover, the combination therapy with SB­3CT and docetaxel was more effective in inhibiting PCa compared with monotherapy. In conclusion, the identification of DEGs and the in vivo experimental results helped to elucidate the molecular mechanisms of PCa and provided a potential strategy for the treatment of PCa.