Pathologic T3a renal cell carcinoma: a classification in need of further refinement

The Anti-Metastatic Action of Oxyresveratrol via Suppression of Phosphoryl-ERK/-PKCα-Mediated Sp1/MMP1 Signaling in Human Renal Carcinoma Cells

Oxyresveratrol (OxyR) exerts biological and pharmacological effects in a variety of tumor cells, including antioxidant action, antitumor activity, and proapoptotic effects. However, the regulation of targeted signaling pathways by OxyR and the mechanism underlying these effects in human renal cell carcinoma (RCC) have been less studied. We observed that OxyR at noncytotoxic doses did not affect the growth of human RCC cells or normal kidney HK2 cells. OxyR inhibited ACHN and Caki-1 cell migration and invasion through targeting matrix metalloproteinase 1 (MMP1) expression. Analysis of clinical databases showed that high MMP1 expression is associated with lower overall survival (OS) in these cancers (p < 0.01). OxyR significantly inhibited the mRNA and protein expression of Sp1. Furthermore, luciferase assay results showed that OxyR inhibited Sp1 transcriptional activity. Additionally, OxyR preferentially suppressed the activation of ERK and PKCα. Treatment with U0126 (MEK inhibitor) or G06976 (PKCα inhibitor) clearly decreased Sp1 and MMP1 expression and inhibited RCC cell migration and invasion. In conclusion, OxyR may be a potential antitumor therapy for the inhibition of migration and invasion by controlling p-ERK/Sp1 and p-PKCα/Sp1-mediated MMP1 expression in RCC.

BIRC6 Modulates the Protein Stability of Axin to Regulate the Growth, Stemness, and Resistance of Renal Cancer Cells via the β-Catenin Pathway

The mechanism underlying the development of renal cell carcinoma (RCC) remains unclear, and effective prevention and therapeutic measures are lacking. BIRC6, a protein inhibitor of apoptosis, has attracted great interest. Our data indicated that overexpression of BIRC6 elevated cell growth, colony formation, migration, and invasion of cultured RCC cells, while siRNA knockdown of BIRC6 suppressed these processes. Additionally, BIRC6 was highly expressed in RCC clinical samples along with a downregulated level of Axin. Immunoprecipitation assays found that BIRC6 interacted with Axin and the two proteins colocalized within the cytoplasm of RCC cells. Overexpression of BIRC6 promoted the ubiquitination modification of Axin, while genetic knockdown of BIRC6 suppressed it. Furthermore, overexpression of BIRC6 significantly promoted the turnover of Axin, suggesting BIRC6's inhibitory effect on Axin protein stability. BIRC6 was also upregulated in cancer stem-like cells of RCC and increased the drug resistance of RCC cells against sunitinib. Western blotting assays showed that the overexpression of BIRC6 upregulated CXCR4 protein expression and activated the β-catenin pathway. Two cell lines were then constructed with BIRC6 overexpressed by lentiviruses. Pharmacological administration of a Wnt/β-catenin inhibitor, XAV-939, or genetic knockdown of β-catenin inhibited cell growth, tumor sphere formation, colony formation, migration, and invasion of BIRC6-overexpressed cells. In vivo administration of XAV-939 markedly suppressed the tumorigenesis of BIRC6-overexpressed RCC cells in nude mice. In conclusion, we propose that BIRC6 activates the β-catenin signaling pathway via mediating the ubiquitination and degradation of Axin, promoting the growth, stemness, and drug resistance of RCC cells. This project aims to elucidate the role of BIRC6 as a potential therapeutic target and provide new insights into the clinical treatment of RCC.

Imaging Features of Renal Masses to Select Optimal Candidates for Tumor Enucleation Partial Nephrectomy

PURPOSE OF REVIEW

The goal of this paper was to critically evaluate preoperative findings that optimally select candidates for renal tumor enucleation partial nephrectomy.

RECENT FINDINGS

Tumor enucleation has been widely accepted as a management option for patients with chronic kidney disease, hereditary renal cell carcinoma, or multifocal disease. Recent evidence suggests safety and efficacy in the management of routine small renal masses. With recent advances in imaging, the literature for ruling out aggressive renal cell carcinoma and selection for tumor enucleation is robust. As the incidence of renal cell carcinoma rises, partial nephrectomy continues to be the mainstay of treatment for localized renal cell carcinoma. Tumor enucleation maximizes preservation of renal parenchyma without hindering oncologic outcomes. It is important to recognize key tumor radiologic findings which urologists may use to optimize patient selection for tumor enucleation.

[Effect of small interfering RNA-mediated BIRC6 silencing on apoptosis and autophagy of renal cancer 786-O cells]

OBJECTIVE

To study the expression of BIRC6 in renal cancer tissues and investigate the effect of BIRC6 silencing on apoptosis and autophagy of 786-O cells.

METHODS

Twenty surgical specimens of renal cancer tissues and adjacent renal tissues were collected from Meizhou People's Hospital between February, 2016 and December, 2018 for detection of BIRC6 protein expression using immunohistochemistry. Renal cancer 786-O cells were transfected with a control small interfering RNA (siRNA) or BIRC6 siRNA via lipofectamine 2000, and the changes in cell proliferation and apoptosis following 5-FU treatment were assessed using CCK8 assay and flow cytometry; the expressions of autophagy-related proteins Beclin and LC3A/B were detected by Western blotting.

RESULTS

The expression of BIRC6 protein was significantly higher in renal cancer tissues than in the adjacent renal tissues. Western blotting showed that siRNA-mediated silencing of BIRC6 significantly lowered the expression of BIRC6 in 786-O cells. In the cells with BIRC6 silencing, treatment with 12.5, 25, 50, 100 and 200 μg/mL 5-FU resulted in significantly higher proliferation inhibition rates than in the cells transfected with the control siRNA (P < 0.01). BIRC6 silencing also significantly increased the apoptosis rate of 786-O cells following 5-FU treatment (P < 0.01). The results of Western blotting showed that BIRC6 silencing significantly lowered the protein expressions of Beclin and LC3A/B in 786-O cells.

CONCLUSIONS

Interference of BIRC6 mediated by siRNA can inhibit autophagy and promote 5-FU-induced apoptosis to enhance the sensitivity of 786-O cells to 5-FU.