National Urological Cancer Center

Beijing, China

National Urological Cancer Center

Beijing, China

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Gong Y.,Peking University | Gong Y.,National Urological Cancer Center | Wang D.,University of Pittsburgh | Dar J.A.,University of Pittsburgh | And 10 more authors.
Endocrinology | Year: 2012

Androgen receptor (AR) plays a key role in prostate development and carcinogenesis. Increased expression and/or stability of AR is associated with sensitization of prostate cancer cells to low levels of androgens, leading to castration resistance. Hence, understanding the mechanisms regulating AR protein stability is clinically relevant and may lead to new approaches to prevent and/or treat prostate cancer. Using fluorescence microscopy, Western blot, and pulse chase assay, we showed that nuclear export signal (NES)AR, a nuclear export signal in the ligand binding domain (LBD) of AR, can significantly enhance the degradation of fusion protein constructs in PC3 prostate cancer cells. The half-life of GFP-NESAR was less than 3 h, which was 10 times shorter than that of green fluorescent protein (GFP) control. Further analysis showed that NESAR can signal for polyubiquitination and that degradation of NESAR-containing fusion proteins can be blocked by proteasome inhibitor MG132. Ubiquitination of GFP-AR or GFP-LBD was suppressed in the presence of dihydrotestosterone, which isknownto suppress NESAR while inducing nuclear localization signal 2 in AR or LBD, suggesting that the export activity of NESAR is required for NES AR-mediated polyubiquitination. Treatment with MG132 also induced aggresome formation of NESAR-containing fusion proteins in perinuclear regions of the transfected PC3 cells, indicating a role for NES AR in inducing unfolded protein responses. The above observations suggest that NESAR plays a key role in AR ubiquitination and proteasome-dependent degradation in prostate cancer cells. Copyright © 2012 by The Endocrine Society.


He W.,Peking University | He W.,National Urological Cancer Center | Li X.,Peking University | Li X.,National Urological Cancer Center | And 15 more authors.
Biochemical and Biophysical Research Communications | Year: 2013

Cell adhesion molecules (CADMs) comprise a protein family whose functions include maintenance of cell polarity and tumor suppression. In this report, we show that the CADM2 gene is repressed in human clear renal cell carcinoma by DNA promoter hypermethylation and/or loss of heterozygosity. Moreover, the loss of CADM2 expression is associated with a higher tumor pathology stage (. p<. 0.05). The re-expression of CADM2 in the renal cancer cell line 786-O significantly suppressed tumor cell growth in vitro and in mouse xenografts by a G1 phase cell cycle arrest and the induction of apoptosis. Lentivirus-mediated CADM2 expression also significantly suppressed cancer cell anchorage-independent growth and invasion. Furthermore, the inhibition of endogenous CADM2 expression using siRNAs induced a tumorigenic phenotype in polarized non-tumorigenic MDCK cells. Thus, we conclude that CADM2 functions as a novel tumor suppressor and may serve as a potential therapeutic target for human renal cell carcinoma. © 2013 Elsevier Inc.


Su B.,Peking University | Su B.,National Urological Cancer Center | Shi B.,Peking University | Tang Y.,Peking University | And 11 more authors.
Prostate | Year: 2015

BACKGROUND. High Mobility Group N (HMGN) proteins are a family of chromatin structural proteins that specifically bind to nucleosome core particles. HMGN5 is a novel and characteristic member of the HMGN protein family. We have previously found that HMGN5 is upregulated in prostate cancer and its downregulation had been demonstrated to induce apoptosis and G2-M cell cycle arrest.METHODS. The radiosensitization effect of HMGN5 knockdown on PC3 and DU145 cells was assessed using clonogenic assay, flow cytometry, and comet assay. The DNA doublestrand break (DSB) repair kinetics of HMGN5 knockdown and control cells after radiation exposure was evaluated using immunocytofluorescence. The mitochondrial reactive oxygen species (ROS) levels were estimated using Dihydrorhodamine 123 (DHR 123) probes. Expression of mitochondrial antioxidant MnSOD was measured by real-time PCR andWestern blot. The expression of antiapoptotic proteins Bcl-2 and Bcl-xL as well as cleavage of caspase-3, caspase-9, and PARP were also measured using Western blot.RESULTS. HMGN5 knockdown cells exhibit decreased clonogenic survival and increased apoptosis rate in response to 2-8 Gy ionizing radiation (IR). Loss of HMGN5 does not affect the DSB repair kinetics after radiation exposure. HMGN5 knockdown cells demonstrated increased mitochondrial ROS level and suppressed induction of MnSOD upon radiation compared with control cells upon radiation. Further, MnSOD knockdown resulted in inhibited cell viability as well as increased mitochondrial ROS level and apoptosis upon radiation in PC3 and DU145 cells. Finally, HMGN5 knockdown cells showed significantly decreased levels of antiapoptotic proteins Bcl-2 and Bcl-xL as well as increased cleavage of caspase-3, caspase-9, and PARP compared with control cells after radiation.CONCLUSIONS. HMGN5 knockdown sensitizes prostate cancer cells to ionizing radiation, and the radiosensitization effect may be partially mediated through suppressed induction of MnSOD and enhanced activation of apoptosis pathway in response to IR. © 2014Wiley Periodicals, Inc.


Qiu W.,Peking University | Qiu W.,National Urological Cancer Center | Su M.,Peking Union Medical College | Xie F.,Peking University | And 12 more authors.
Cell Death and Disease | Year: 2014

Lysosomes are acidic organelles that have a crucial role in degrading intracellular macromolecules and organelles during the final stage of autophagy. Tetrandrine (Tet), a bisbenzylisoquinoline alkaloid, was reported as an autophagy activator. Here, in contrast with previous studies, we show that Tet is a potent lysosomal deacidification agent and is able to block autophagic flux in the degradation stage. Single-agent Tet induces significant apoptosis both in vitro and in xenograft models. In the presence of Tet, apoptosis was preceded by a robust accumulation of autophagosomes and an increased level of microtubule-associated protein 1 light chain 3, type II (LC3-II). However, Tet increased the level of sequestosome 1 and decreased the turnover of LC3, indicating the blockade of autophagic flux in the degradation stage. As blockade of autophagic flux decreases the recycling of cellular fuels, Tet reduces the uptake of glucose in cancer cells. These effects lead to insufficient substrates for tricarboxylic acid (TCA) cycle and impaired oxidative phosphorylation. Blunting autophagosome formation using 3-methyladenine or genetic knockdown of Beclin-1 failed to rescue cells upon Tet treatment. By contrast, addition of methyl pyruvate to supplement TCA substrates protected Tet-treated tumor cells. These results demonstrate that energetic impairment is required in Tet-induced apoptosis. Tet, as a potent lysosomal inhibitor, is translatable to the treatment of malignant tumor patients. © 2014 Macmillan Publishers Limited All rights reserved.


Su B.,Peking University | Su B.,National Urological Cancer Center | Zhao W.,Peking University | Shi B.,Peking University | And 18 more authors.
Molecular Cancer | Year: 2014

Background: MicroRNAs are endogenous small noncoding RNAs that are functionally involved in numerous critical cellular processes including tumorigenesis. Data mining using a microRNA array database suggested that let-7d microRNA may be associated with renal cell carcinoma (RCC) malignant progression. Here, we performed further analyses to determine whether let-7d is functionally linked to RCC malignancy. Methods: Quantitative real-time PCR was used to determine the level of mature let-7d in RCC clinical specimens and its correlation with clinicopathological data. Immunohistochemical staining was conducted to characterize the stroma of RCC. Let-7d overexpressing RCC cell lines combined with mouse models bearing cell-derived xenografts and patient-derived xenografts were used to assess the functional role of let-7d in vitro and in vivo. Results: Downregulation of let-7d in clinical RCC samples was associated with advanced tumor grade and T stage and increased vascular invasion. An inverse relationship between let-7d expression and macrophage infiltration was found in clinical RCC samples. Functional studies indicated that ectopic expression of let-7d significantly inhibited RCC cell proliferation, migration, and peripheral blood monocyte (PBMC) recruitment in vitro, as well as tumor growth, metastasis, and tumor macrophage infiltration in vivo. In silico analysis and subsequent experimental validation confirmed collagen, type III, alpha 1 (COL3A1) and C-C subfamily chemokine member CCL7 as direct let-7d target genes. The addition of COL3A1 and CCL7 counteracted the inhibitory effects of let-7d on RCC cell proliferation, migration, and PBMC recruitment. The inhibition of let-7d increased cell proliferation, migration, and PBMC recruitment by the enhanced expression of COL3A1 and CCL7 genes in vitro. The mRNA levels of COL3A1 and CCL7 were inversely correlated with let-7d level in RCC clinical specimens. Conclusions: These results suggest that let-7d may suppress RCC growth, metastasis, and tumor macrophage infiltration at least partially through targeting COL3A1 and CCL7. © 2014 Su et al.; licensee BioMed Central Ltd.


Zhang B.,Peking University | Zhang B.,National Urological Cancer Center | Shen C.,Peking University | Shen C.,National Urological Cancer Center | And 4 more authors.
Transplantation | Year: 2014

BACKGROUND: Urothelial carcinoma (UC) is a common complication after renal replacement therapy (RRT) among Chinese end-stage renal disease (ESRD) patients. It is unclear whether there are any differences in the clinicopathologic characteristics of UC between renal transplantation (RT) and dialysis patients; such differences could impact RRT modality selection. METHODS: We retrospectively reviewed clinicopathologic data for 27 RT patients and 40 dialysis patients who were diagnosed with UC in our center to explore differences in the clinicopathologic characteristics of UC and prognoses between the two groups. RESULTS: The median follow-up period was 92 months (2-137) for the RT group and 71 months (18-155) for the dialysis group. The demographic and baseline data showed no significant differences between the two groups. Upper urinary tract UC (UUC) occurred more frequently in the RT group (22 UUCs in 39 UCs), whereas bladder UC (BUC) predominated in the dialysis group (33 BUCs in 49 UCs) (P=0.025). The pathologic grading in the RT group was significantly higher than that in the dialysis group (P=0.046 for WHO1973 grading, P=0.026 for WHO2004 grading), whereas the difference in tumor stage was not significant (P=0.089). The RT group manifested a higher recurrence rate than the dialysis group (P=0.024). However, the overall and cancer-specific survival rates between the two groups were not significantly different (P=0.239 and P=0.818, respectively). CONCLUSION: Certain traits of UC, including tumor site, pathologic grading, and recurrence-free survival, were notably different between RT and dialysis patients, but the overall and cancer-specific survival rates were similar. © 2014 by Lippincott Williams and Wilkins.


Wu P.,Peking University | Wu P.,National Urological Cancer Center | Zhang N.,Capital University of Medicine Science | Wang X.,Peking University | And 8 more authors.
Journal of Human Genetics | Year: 2012

Von Hippel-Lindau (VHL) disease is an autosomal dominant familial cancer syndrome caused by germline mutations in VHL tumor suppressor gene. It is characterized by hemangioblastoma in central nervous system and retina, renal cell carcinoma or cyst, pheochromocytoma, pancreatic cyst and tumor, endolymphatic-sac tumor, and papillary cystadenoma in epididymis and broad ligament. Here, we used PCR-direct sequencing and universal primer quantitative fluorescent multiplex PCR (UPQFM-PCR) to detect VHL mutations in 16 patients clinically diagnosed with VHL disease. PCR-direct sequencing detected 12 germline mutations (75%, 12/16), in which a novel mutation of c.451A>T/p.Ile151Phe found in one proband had not been reported previously. UPQFM-PCR found two large deletions (12.5%, 2/16). The two remaining patients carried non-typical disease-causing mutations, including one silent mutation (c.481C>A/p.Arg161Arg) and one mutation in 3′-UTR (c.642+70C>A). Remarkably, 56.3% (9/16) probands did not have family history of VHL disease, suggesting the higher frequency of de novo mutations in Chinese patients. We also summarized Chinese VHL disease patients with VHL mutation findings published in the literature to provide information about the spectrum of VHL mutations in Chinese VHL disease patients. © 2012 The Japan Society of Human Genetics All rights reserved.


Ji S.-Q.,Peking University | Ji S.-Q.,National Urological Cancer Center | Yao L.,Peking University | Yao L.,National Urological Cancer Center | And 6 more authors.
Journal of Experimental and Clinical Cancer Research | Year: 2012

Background: The nucleosome binding protein 1 (HMGN5/NSBP1) is a member of the HMGN protein family and is highly expressed in several kinds of cancer. Nevertheless, the role of NSBP1 in clear cell renal cell carcinoma (ccRCC) remains unclear. This study aimed to confirm the oncogenic role of NSBP1 in ccRCC using in vitro and in vivo models and explore the mechanism by which NSBP1 contributes to ccRCC tumorigenesis. Methods. NSBP1 expression was detected in renal tissues from 152 ccRCC patients by immunohistochemistry, and examined in ccRCC cell lines by RT-PCR and Western blot analysis. ccRCC cells were transfected by NSBP1 RNAi and cell viability, apoptosis and invasion were detected by cell vitality test, flow cytometry and transwell assay in vitro. Xenograft in nude mice was also employed to examine the tumorigenesis of ccRCC cells depleted of NSBP1. Results: Immunohistostaining showed strong immunoreactivity of NSBP1 in all ccRCC tissues and NSBP1 expression level was associated with tumor grade (p = 0.04). NSBP1 expression at mRNA and protein levels was high in ccRCC cell lines. Knockdown of NSBP1 induced cell cycle arrest and apoptosis, and inhibited invasion in 786-O cells. Western blot analysis demonstrated increased expression of Bax and decreased expression of Bcl-2, CyclinB1, VEGF, VEGFR-2, MMP-2, MMP-9, c-fos and c-jun in 786-O cells depleted of NSBP1. In vivo study further showed that knockdown of NSBP1 affected the tumorigenesis of ccRCC cells in nude mice. Conclusions: NSBP1 plays oncogenic role in ccRCCs by promoting cell proliferation and invasion, and could be exploited as a target for ccRCC treatment. © 2012 Ji et al; licensee BioMed Central Ltd.


Xie F.,Peking University | Xie F.,National Urological Cancer Center | Su M.,Peking Union Medical College | Qiu W.,Peking University | And 12 more authors.
International Journal of Molecular Sciences | Year: 2013

Kaempferol (Kae), a natural flavonoid, is widely distributed in fruits and vegetables. Previous studies have identified Kae as a possible cancer preventive and therapeutic agent. We found Kae to exhibit potent antiproliferation and anti-migration effects in human bladder cancer EJ cells. Kaempferol robustly induced apoptosis in EJ cells in a dose-dependent manner, as evidenced by increased cleavage of caspase-3. Furthermore, we found Kae-induced apoptosis in EJ cells to be associated with phosphatase and the tensin homolog deleted on the chromosome 10 (PTEN)/PI3K/Akt pathway. Kae significantly increased PTEN and decreased Akt phosphorylation. Kae-induced apoptosis was partially attenuated in PTEN-knockdown cells. Our findings indicate that Kae could be an alternative medicine for bladder cancer, based on a PTEN activation mechanism. © 2013 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | National Research Center for Genitourinary Oncology, National Urological Cancer Center and Peking University
Type: Journal Article | Journal: PloS one | Year: 2016

Cyclin D2 (CCND2) is a member of the D-type cyclins, which plays a pivotal role in cell cycle regulation, differentiation and malignant transformation. However, its expression status and relative regulation mechanism remains unclear in renal cell cancer (RCC). In our study, the mRNA expression level of CCND2 is down-regulated in 22/23 paired RCC tissues (p<0.05). In addition, its protein expression level is also decreased in 43/43 RCC tumor tissues compared with its corresponding non-malignant tissues (p<0.001). We further detected that CCND2 was down-regulated or silenced in 6/7 RCC cell lines, but expressed in normal human proximal tubular (HK-2) cell line. Subsequently, MSP and BGS results showed that the methylation status in CCND2 promoter region is closely associated with its expression level in RCC cell lines. Treatment with 5-Aza with or without TSA restored CCND2 expression in several methylated RCC cell lines. Among the 102 RCC tumors, methylation of CCND2 was detected in 29/102 (28%) cases. Only 2/23 (8.7%) adjacent non-malignant tissues showed methylation. We then analyzed the correlation of clinical features and its promoter methylation. Collectively, our data suggested that loss of CCND2 expression is closely associated with the promoter aberrant methylation.

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