BIRC6 Modulates the Protein Stability of Axin to Regulate the Growth, Stemness, and Resistance of Renal Cancer Cells via the ß-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 ß-catenin pathway. Two cell lines were then constructed with BIRC6 overexpressed by lentiviruses. Pharmacological administration of a Wnt/ß-catenin inhibitor, XAV-939, or genetic knockdown of ß-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 ß-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.

miR-200a-3p facilitates bladder cancer cell proliferation by targeting the A20 gene.

BACKGROUND: MicroRNAs (miRs) are endogenous, single-stranded, noncoding RNAs that are involved in various physiological processes, and the development and the progression of various types of cancer. Specifically, the role of miR-200a-3p has been implicated in various types of cancer in contributing to a diverse array of cancer types has been previously reported. The present study aimed to investigate the expression levels of miR-200a-3p in human bladder cancer, as well as its potential role in disease pathogenesis. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of has-mir-200a-3p and tumor necrosis factor α (TNF-α) induced protein 3 (A20) in tumor tissues and cell lines. Dual-luciferase reporter assay and combination with the expression intervention of hsa-mir-200a-3p and A20 in bladder cancer cell lines to clarify the binding relationship between hsa-mir-200a-3p and A20.After the expression intervention of hsa-mir-200a-3p and A20 in bladder cancer cells, the changes of cell proliferation, cell apoptosis, cell cycle, wound-healing ability and migration ability were detected by CCK8, flow cytometry, wound-healing and Transwell methods. Xenograft transplantation model was performed subcutaneously in nude mice by implantation of J82 and T24 cells, and then the bladder cancer growth curve was calculated from mice exposed to has-mir-200a-3p minic or minic-NC. RESULTS: Bladder cancer tissues demonstrated significantly upregulated miR-200a-3p expression levels. Moreover, increased miR-200a-3p expression was significantly associated with distant metastasis and advanced stage. In addition, compared with the miR-control (Ctr) group, miR-200a-3p overexpression promoted bladder cancer cell proliferation, migration, invasion, cell cycle, and release of inflammatory cytokines, but inhibited cell apoptosis. Mechanistically, A20 was identified as a target gene of miR-200a-3p in bladder cancer cell lines. Moreover, compared with the miR-Ctr group, the miR-200a-3p overexpression group exhibited significantly promoted tumor growth in vivo, and A20 overexpression blocked the promoting effect of miR-200a-3p on bladder cancer. CONCLUSIONS: The results of the present study indicated that miR-200a-3p might serve act as an oncogene in human bladder cancer by targeting a novel the gene A20 gene; therefore, miR-200a-3p and A20 might serve could serve as novel therapeutic targets for bladder cancer.

[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.

A Atractylodes lancea polysaccharide inhibits metastasis of human osteosarcoma U-2 OS cells by blocking sialyl Lewis X (sLex )/E-selectin binding.

In this study, a new water and alkaline-soluble polysaccharide (ALP), with an average molecular weight of 6.63 × 104  Da, was successfully purified from the rhizomes of Atractylodes lancea. GC analysis demonstrated that ALP was a kind of glucan. The effect of the ALP on the interaction between E-selectin and sialyl Lewis X (sLex ) was examined in human osteosarcoma U-2 OS cells. It was obvious that the expression of sLex antigen on the surface of U-2 OS cells was visible under fluorescence microscopy. The addition of ALP (0.5, 1 and 2 mg/mL) resulted in a marked inhibition on the adhesion, migration and invasion of U-2 OS cells to human umbilical vein endothelial cells (HUVECs), which was achieved by the decreased sLex expression on U-2 OS cells. Additionally, the induction of apoptosis can be observed in U-2 OS cells following ALP treatment using TUNEL staining and Annexin V-FITC/PI double-staining analysis on flow cytometry. In conclusion, these results indicated that ALP exerted anti-metastatic activity towards osteosarcoma cells via inhibition of sLex /E-selectin binding, which suggested that ALP could be a potent agent for human osteosarcoma intervention.

Eupatilin Inhibits Renal Cancer Growth by Downregulating MicroRNA-21 through the Activation of YAP1.

Renal cell carcinoma (RCC) is the second most common human urinary tumor. Eupatilin is the main active ingredient of the traditional Chinese medicine Artemisia asiatica. The effect of Eupatilin on RCC and the underlying mechanism remain unknown. Here, we investigated the anticancer effects and mechanisms of Eupatilin in RCC in vivo and in vitro, laying an experimental foundation for the clinical application of Eupatilin in the treatment of RCC. The results showed that Eupatilin significantly inhibited 786-O cell viability and migration and promoted apoptosis. Eupatilin inhibited the expression of miR-21 in 786-O cells, and overexpression of miR-21 suppressed the effect of Eupatilin on viability, apoptosis, and migration in 786-O cells. Eupatilin inhibited the growth of renal tumors in nude mice by downregulating miR-21. YAP1, which was identified as a target of miR-21, showed significantly lower expression in RCC tissues than in healthy tissues. miR-21 significantly inhibited YAP1 protein expression in 786-O cells and tumor tissues isolated from nude mice, and YAP1 attenuated the effect of miR-21 on the viability, apoptosis, and migration of 786-O cells. In conclusion, Eupatilin inhibited the expression of miR-21, which mediated the proapoptotic and antimigratory effects of Eupatilin by suppressing YAP1 in renal cancer cells. These results suggested that Eupatilin could be a potent agent for the treatment of RCC.

Toll-like receptor 4 promotes high glucose-induced catabolic and inflammatory responses in chondrocytes in an NF-κB-dependent manner.

Diabetes is an independent risk factor for knee osteoarthritis (OA), and hyperglycaemia-induced inflammation is considered to play an important role in their connection. The Toll-like receptor 4 (TLR4) regulates inflammatory responses in several pathological conditions including diabetes and OA. However, its role in diabetes-associated OA is poorly understood. In this study, we found that TLR4 expression was higher in OA cartilage from patients with type 2 diabetes mellitus (T2DM) than that from non-T2DM patients. Similarly, its expression was induced in primary mouse chondrocytes treated with high glucose, which suggests that TLR4 upregulation in T2DM-associated OA cartilage may originate from hyperglycaemia stimulation. We further discovered that TLR4 promoted high glucose-induced catabolic and inflammatory responses in chondrocytes, and mechanistically, these effects could be explained by the exacerbated activation of the transcription factor nuclear factor kappa B (NF-κB) pathway, since its inhibition by Bay 11-7082 abrogated TLR4 effects on high glucose-treated chondrocytes. Taken together, these findings may reveal a promotive role of TLR4 in regulating hyperglycaemia-induced catabolism and inflammation in T2DM-associated OA, and also implicate that TLR4 inhibition might be of therapeutic significance in treating T2DM-associated OA.

Receptor for advanced glycation end products (RAGE) partially mediates HMGB1-ERKs activation in clear cell renal cell carcinoma.

PURPOSE: To explore the expression of receptor for advanced glycation end products (RAGE) and high-mobility group box-1 (HMGB1) and their role in clear cell renal cell carcinoma (CCRCC) development and progression. METHODS: Expression of RAGE and HMGB1 was examined in RCC using tissue microarrays. In vitro, quiescent or RAGE-reduced RCC cells were subjected to treatment with HMGB1 and harvested for detecting ERK1/2 phosphorylation via Western blot. Further cell proliferation, migration and invasion were evaluated by Ki-67 immunostaining, wound healing and matrigel invasion assay, respectively. RESULTS: ①Elevated co-expression of RAGE and HMGB1 in CCRCC was correlated positively with patients' clinical parameters including tumor size, nuclear Fuhrman grade and clinical stage. ②HMGB1 incubation induced ERK1/2 activation in a time- and dose-dependent manner, which could be completely blocked by U0126 (MEK1/2 inhibitor) and partially reversed by RAGE knockdown. ③RAGE knockdown partially reversed the promoted effect of cell proliferation, migration and invasion induced by HMGB1. CONCLUSION: HMGB1 promotes the development and progression of CCRCC via ERK1/2 activation, which is partially mediated by RAGE.