Background/Aims: Cancer stem cells (CSCs) contribute to tumorgenesis, invasion and metastasis, and are typically resistant to chemotherapy. Recent reports showed that SIRT2 was upregulated in several cancers. However, whether SIRT2 may be a CSC marker in renal cell carcinoma (RCC) is not clear. Methods: The SIRT2 levels in both RCC samples and the corresponding normal kidney samples (NT) were assessed by RT-qPCR and ELISA. The association between SIRT2 levels and patient survival was examined using Bivariate correlation analysis by Spearman’s Rank Correlation Coefficients. The survival of the patients was analyzed using Kaplan-Meier curve. In vitro, 2 RCC cell lines were co-transduced with a lentivirus expressing both a green fluorescent protein and a luciferase reporter under a cytomegalovirus promoter, and another lentivirus expressing a nuclear red fluorescent protein reporter under the control of a SIRT2 promoter for differentiating SIRT2+ vs SIRT2- RCC cells by flow cytometry. The SIRT2+ vs SIRT2- RCC cells were examined for the potential of forming tumor sphere in a tumor sphere formation assay, resistance to fluorouracil-induced apoptosis by CCK-8 assay, and the frequency of forming tumor in vivo after serial adoptive transplantation by bioluminescence. Results: The levels of SIRT2 were higher in RCC samples than NT. The prognosis of RCC patients with high SIRT2 was worse than that of with low SIRT2. Compared to SIRT2- cells, SIRT2+ cells formed more tumor spheres, appeared to be more resistant towards fluorouracil-induced apoptosis, and generated bigger tumors with higher frequency after serial adoptive transplantation. Conclusion: SIRT2 may be highly expressed in the RCC stem-like cells and regulates cancer metastasis. Selective knockout of SIRT2 or elimination of SIRT2+ cells may improve the therapeutic outcome for patients with RCC.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent. Epigallocatechin-3-gallate (EGCG) is a polyphenolic constituent of green tea. In this study, potentiating effect of EGCG on TRAIL-induced apoptosis human renal carcinoma cell line 786-O which is relatively resistant to TRAIL was examined, and the possible mechanism was investigated. Here, we show that co-treatment with EGCG and TRAIL induced significantly more profound apoptosis in 786-O cells. Treatment of 786-O cells with EGCG and TRAIL downregulated c-FLIP, Mcl-1, and Bcl-2 proteins in a caspase-dependent pathway. Moreover, we found that pretreatment with NAC markedly inhibited the expression levels of c-FLIP, Mcl-1, and Bcl-2 downregulated by the combinatory treatment, suggesting that the regulating effect of EGCG on these above apoptosis-relevant molecules was partially mediated by generation of ROS. Taken together, the present study demonstrates that EGCG sensitizes human 786-O renal cell carcinoma cells to TRAIL-induced apoptosis by downregulation of c-FLIP, Mcl-1, and Bcl-2.

MicroRNAs (miRs) have emerged as critical modulators of tumor initiation and progression in numerous types of human cancer, including clear cell renal cell carcinoma (ccRCC), which is the most common subtype of renal cell carcinoma. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a newly characterized oncoprotein and its overexpression has been reported to promote cellular epithelial-mesenchymal transition and the tumor progression of ccRCC. The present study examined the effects of miR-218 on CIP2A expression in ccRCC cells. The results demonstrated that the expression level of miR-218 was lower in ccRCC tissues compared with that in adjacent non-tumor renal tissues. In addition, it was identified that miR-128 could directly bind to the 3′-untranslated region of CIP2A. Furthermore, a negative correlation between the expression levels of miR-218 and CIP2A was detected in ccRCC. Additionally, the downregulation of CIP2A or overexpression of miR-218 in ccRCC cells was revealed to inhibit cell proliferation and migration. In summary, these data suggest that miR-218 serves a role in the regulation of CIP2A and elucidate its consequences on tumor progression, tumor cell proliferation and migration. These results indicate that miR-218 may exhibit potential as a molecular target for the treatment of ccRCC.

PurposeTo assess the safety and efficacy of an ultramini nephrostomy tract, which we were using for the first time, combined with flexible ureterorenoscopy (URS) in the treatment of pediatric patients with multiple renal calculi.Materials and MethodsTwenty pediatric patients (age, ≤6 years) underwent ultramini percutaneous nephrolithotomy (PCNL) combined with flexible URS. The group had multiple renal calculi, which were bilateral in 3 cases and were located in a total of 23 sites. The calculi were located in 2 calyces in 10 cases, scattered in more than 2 calyces in 7 cases, and limited to 1 calyx in 3 cases. The average patient age was 37.35 months (range, 14-68 months). The average stone diameter was 2.0 cm (range, 1-3.0 cm). In all patients, an ultramini nephrostomy tract was established under ultrasound guidance (dilated to F10) with simultaneous sheath placement. The flexible URS was placed into the collecting system during holmium laser lithotripsy.ResultsWhen ultramini PCNL was combined with flexible ureterorenoscopic holmium laser lithotripsy, the complete stone-free rate was 87% (20/23). The average level of hemoglobin decreased to 1.0 g/dL after the operation. No blood transfusions were needed. Levels of blood urea nitrogen, creatinine, and C-reactive protein were not significantly different before and after the operation. The average duration of hospitalization was approximately 4.85 days, and all cases were followed up for 6 to 12 months. No complications were found.ConclusionsUltramini PCNL combined with flexible ureterorenoscopic holmium laser lithotripsy is a safe and effective treatment for children with multiple renal calculi.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for anticancer therapy. The identification of small molecules that can establish the sensitivity of prostate cancer (PCa) cells to TRAIL-induced apoptosis is crucial for the targeted treatment of PCa. PC3, DU145, JAC-1, TsuPr1, and LNCaP cells were treated with Andrographolide (Andro) and TRAIL, and the apoptosis was measured using the Annexin V/PI double staining method. Real time-polymerase chain reaction (PCR) and Western blot analysis were performed to measure the expression levels of target molecules. RNA interference technique was used to down-regulate the expression of the target protein. We established a nude mouse xenograft model of PCa, which was used to measure the caspase-3 activity in the tumor cells using flow cytometry. In this research study, our results demonstrated that Andro preferentially increased the sensitivity of PCa cells to TRAIL-induced apoptosis at subtoxic concentrations, and the regulation mechanism was related to the up-regulation of DR4. In addition, it also increased the p53 expression and led to the generation of reactive oxygen species (ROS) in the cells. Further research revealed that the DR4 inhibition, p53 expression, and ROS generation can significantly reduce the apoptosis induced by the combination of TRAIL and Andro in PCa cells. In conclusion, Andro increases the sensitivity of PCa cells to TRAIL-induced apoptosis through the generation of ROS and up-regulation of p53 and then promotes PCa cell apoptosis associated with the activation of DR4.