Cyclin E and p27 protein content in human renal cell carcinoma: clinical outcome and associations with cyclin D

Aberrations in the G1-S transition have been observed in several malignancies, suggesting that cell cycle defects are linked to the activation of oncogenes and inactivation of suppressor genes involved in the transformation process. The frequency of G1/S aberrations in human renal cell carcinoma (RCC) has not been fully clarified. We have therefore analyzed the cyclin E content, using Western blotting, in 79 RCC and 12 corresponding kidney cortex tissues as well as the fraction of p27-positive cells in 73 RCCs, using immunohistochemistry. Most of the tumors (65%) exhibited higher cyclin E levels than corresponding normal kidney cortex tissues. However, only a small fraction of the tumors (3 of 80) had excessive levels of cyclin E when cyclin E levels were compared with proliferation. Cyclin E levels higher than the median value were associated with aneuploidy (p = 0.025), high stage (p = 0.027), high grade (p = 0.013) and high erythrocyte sedimentation rate (ESR; p = 0.005). Cyclin E was further inversely correlated with cyclin D1 (p = 0.023) and positively correlated with cyclin D3 (p = 0.003). Most tumors (76%) demonstrated a normal fraction of p27-positive cells. There was an inverse correlation between p27 positivity and tumor size (p = 0.007), despite a lack of correlation between p27 and proliferation. Patients with p27 low tumors had a poor survival (p = 0.002). There was no correlation between p27 and cyclin E levels. In summary, the results suggest that protein expression of cyclin E and/or p27 is linked to tumor behavior.     

CIAPIN1 inhibits the growth and proliferation of clear cell renal cell carcinoma

Our previous studies indicated a direct correlation with loss of CIAPIN1 and carcinogenesis of tumor in human gastric cancer. Here we presented that the expression of CIAPIN1 was absent or significantly decreased in 102 cases of clear cell renal cell carcinoma (CCRCC) tissues (P < 0.05). Up-regulating CIAPIN1 by adenoviral vectors exhibited significant inhibition of CCRCC-derived cell growth in vitro and in vivo with G1 cell cycle arrest. Simultaneously, CIAPIN1-induced growth suppression was found partially to regulate various proteins, including inhibition of cyclinD1, cyclinE, cdk2, cdk4, p-Rb and VEGF, but up-regulation of p27^Kip1 and Rb.     

cyclin D1和kip1在肾细胞癌组织中的表达

目的：采用免疫组化方法检测cyclin D1和kip1在肾细胞癌中的表达,以期获得评估肾细胞癌恶性程度及预后评价的指标.方法：将肾细胞癌肿瘤组织及正常组织用免疫组化方法进行染色,按半定量方法进行结果判定,结合临床资料进行分析.结果：cyclin D1和kip1在肿瘤组织与正常组织中的表达具有显著性差异（P＜0.01）.cyclin D1和kip1在不同性别组、年龄组和直径组肿瘤患者组织中的表达对比不具有显著性差异（P＞0.05）.cyclin D1和kip1在不同病理分级组肿瘤患者组织中的表达具有显著性差异（P＜0.01）.kip1表达与肿瘤分化程度呈正相关（r=0.40）.cyclin D1表达与肿瘤分化程度呈负相关（r=0.45）.结论：cyclin D1和kip1在肿瘤细胞的表达呈现一定规律,可以作为判断肾细胞癌肿瘤细胞分化程度及预后的重要指标,同时也为靶向治疗提供了更多的靶点选择.     

Expression and regulatory effects on cancer cell behavior of NELL1 and NELL2 in human renal cell carcinoma

Neural epidermal growth factor‐like like (NELL) 1 and 2 constitute a family of multimeric and multimodular extracellular glycoproteins. Although the osteogenic effects of NELL1 and functions of NELL2 in neural development have been reported, their expression and functions in cancer are largely unknown. In this study, we examined expression of NELL1 and NELL2 in renal cell carcinoma (RCC) using clinical specimens and cell lines. We show that, whereas NELL1 and NELL2 proteins are strongly expressed in renal tubules in non‐cancerous areas of RCC specimens, their expression is significantly downregulated in cancerous areas. Silencing of NELL1 and NELL2 mRNA expression was also detected in RCC cell lines. Analysis of NELL1/2 promoter methylation status indicated that the CpG islands in the NELL1 and NELL2 genes are hypermethylated in RCC cell lines. NELL1 and NELL2 bind to RCC cells, suggesting that these cells express a receptor for NELL1 and NELL2 that can transduce signals. Furthermore, we found that both NELL1 and NELL2 inhibit RCC cell migration, and NELL1 further inhibits RCC cell adhesion. These results suggest that silencing of NELL gene expression by promoter hypermethylation plays roles in RCC progression by affecting cancer cell behavior.     

Expression of cyclin D1, D3, E,and p27 in human renal cell carcinoma analysed by tissue microarray

Aberrations in the G1/S transition of the cell cycle have been observed in many malignancies and seem to be critical in the transformation process. Few studies have delineated the presence of G1/S regulatory defects and their clinical relevance in renal cell carcinoma (RCC). Therefore, we have examined the protein contents of cyclin D1, D3, E, and p27 in 218 RCCs, using tissue microarray and immunohistochemistry. The results from a subset of tumours were confirmed by Western blotting and immunohistochemical staining of regular tissue sections. Interestingly, low protein contents of cyclin D1 and p27 were associated with high nuclear grade, large tumour size, and poor prognosis for patients with conventional tumours. We further observed substantial differences in the pattern of G1/S regulatory defects between the different RCC subtypes. The majority of both conventional and papillary cases expressed p27; however, chromophobe tumours generally lacked p27 staining. In addition, conventional RCCs often expressed high cyclin D1 protein levels, while papillary RCCs exhibited high cyclin E. In summary, we have shown that G1/S regulatory defects are present in RCC and are associated with clinico-pathological parameters. The pattern of cell cycle regulatory defects also differed between RCC subtypes.     

Knockdown of the nucleosome binding protein 1 inhibits the growth and invasion of clear cell renal cell carcinoma cells in vitro and in vivo

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.     

长链非编码RNA ARAP1-AS1在肾透明细胞癌中的表达及作用研究

背景与目的：长链非编码RNA（long non-coding RNA,lncRNA）ARAP1-AS1在多种肿瘤中异常表达,但其在肾透明细胞癌（clear cell renal cell carcinoma,ccRCC）中的作用尚不清楚。探讨ARAP1-AS1在ccRCC中的生物学作用。方法：通过GEPIA数据库分析ARAP1-AS1在ccRCC组织中的表达及其与临床病理学特征及患者生存率的关系。采用实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR）检测ccRCC组织及邻近的非肿瘤组织中ARAP1-AS1的表达水平。将患者分为ARAP1-AS1高表达组和低表达组,分析ARAP1-AS1的表达水平与患者临床病理学特征之间的关系,并进行生存分析。通过细胞计数试剂盒-8（cell counting kit-8,CCK-8）实验、transwell迁移实验及侵袭实验检测ARAP1-AS1对ccRCC细胞体外增殖、迁移及侵袭能力的影响。采用蛋白质印迹法（Western blot）检测Wnt/β-catenin信号通路相关蛋白表达变化。采用BALB/c裸小鼠移植瘤模型分析ARAP1-AS1对ccRCC细胞体内成瘤能力的影响。结果：GEPIA数据库分析结果显示,ARAP1-AS1在ccRCC中高表达,且与患者肿瘤高分期及较差的生存率相关（P均<0.05）。RTFQ-PCR显示,ARAP1-AS1在ccRCC组织及细胞系中高表达,ARAP1-AS1的高表达与肿瘤大小和分期相关（P均<0.05）。ARAP1-AS1高表达患者的总生存率较差（P<0.05）。沉默ARAP1-AS1的表达可以抑制ccRCC细胞增殖、迁移和侵袭（P均<0.05）。沉默ARAP1-AS1可以降低Wnt/β-catenin信号通路相关蛋白的表达水平（P均<0.05）。沉默ARAP1-AS1可使ccRCC细胞体内成瘤能力减弱,并使Ki-67增殖指数降低。结论：ARAP1-AS1可通过激活Wnt/β-catenin信号通路促进ccRCC的进展。     

肾透明细胞癌预后相关蛋白标志物的研究进展

肾细胞癌(renal cell carcinoma,RCC)是人类最常见的泌尿系统恶性肿瘤之一,其最常见的病理类型为肾透明细胞癌（clear cell renal cell carcinoma,ccRCC）。近年来,国内外诸多研究报道多种蛋白的表达与ccRCC的预后密切相关。本文就这些蛋白标志物在判断ccRCC患者预后方面的重要作用做一综述。     

CDK1/FBXW7 facilitates degradation and ubiquitination of MLST8 to inhibit progression of renal cell carcinoma

Recent studies have reported that MLST8 is upregulated in many malignant tumors. Nevertheless, the underlying molecular mechanism is still unclear. The aim of this work was to investigate how MLST8 contributes to the development and progression of clear cell renal cell carcinoma (ccRCC). MLST8 is an oncogenic protein in the TCGA database and ccRCC clinical specimens. We also ascertain that MLST8 interacts with FBXW7, which was universally regarded as an E3 ubiquitin ligase. MLST8 can be degraded and ubiquitinated by tumor suppressor FBXW7. FBXW7 recognizes a consensus motif (T/S) PXX (S/T/D/E) of MLST8 and triggers MLST8 degradation via the ubiquitin‐proteasome pathway. Strikingly, the activated cyclin dependent kinase 1 (CDK1) kinase engages in the MLST8 phosphorylation required for FBXW7‐mediated degradation. In vitro, we further prove that MLST8 is an essential mediator of FBXW7 inactivation‐induced tumor growth, migration, and invasion. Furthermore, the MLST8 and FBXW7 proteins are negatively correlated in human renal cancer specimens. Our findings suggest that MLST8 is a putative oncogene that functions via interaction with FBXW7, and inhibition MLST8 could be a potential future target in ccRCC treatment.     

钙结合蛋白S100A1在肾细胞肿瘤中的研究进展

不同类型的肾细胞肿瘤形态学、遗传学特征及预后均有不同,但它们在形态学上常有一定的重叠,有时得出准确的病理诊断十分困难。钙结合家族S100蛋白中的S100A1最近发现在。肾细胞肿瘤中表达,尤其在肾嫌色细胞癌及嗜酸细胞瘤的鉴别诊断中很有意义,且可能与肾细胞癌的预后有关。     

LncRNA GAS6 antisense RNA 1 facilitates the tumorigenesis of clear cell renal cell carcinoma by regulating the AMP-activated protein kinase/mTOR signaling pathway

The role of GAS6 antisense RNA 1 (GAS6-AS1) in clear cell renal cell carcinoma (ccRCC) remains unclear. The aim of the present study was to investigate the role and molecular mechanisms of GAS6-AS1 in the progression of ccRCC. GAS6-AS1 was found to be upregulated in ccRCC tissues and cell lines, and patients with high GAS6-AS1 expression levels exhibited a poor prognosis. Small interfering (si)RNA GAS6-AS1 inhibited the activity, colony formation, invasiveness and glycolysis of OSRC-2 and SW839 cells, while GAS6-AS1 overexpression promoted these functions. Moreover, si-GAS6-AS1 increased the phosphorylation level of AMP-activated protein kinase (AMPK) and decreased that of mTOR, as well as decreasing proliferating cell nuclear antigen (PCNA), MMP-2 and hexokinase-2 (HK2) expression, which were reversed by inhibiting AMPK or mTOR. In addition, the silencing of GAS6-AS1 suppressed the growth of xenografted tumors and attenuated the expression of PCNA, MMP-2 and HK2 in tumor tissues. These findings conclude that GAS6-AS1 regulated the proliferation, invasiveness and glycolysis of ccRCC cells by regulating the AMPK/mTOR signaling pathway, and suggest that GAS6-AS1 may be a potential therapeutic target for ccRCC.     

The ribosomal protein S6 in renal cell carcinoma: functional relevance and potential as biomarker

Inhibitors of the mTOR pathway, such as everolimus, are promising compounds to treat patients with renal cell carcinomas (RCCs). However, the precise mechanisms of action are far from clear, and biomarkers predicting the response to mTOR inhibitors are still missing. Here, we provide evidence that in RCCs the rpS6 protein is the major mediator of anti-tumoral effects exerted by everolimus. Inhibition of mTOR signaling results in substantially decreased clonogenicity and proliferation of RCC cells, but did not significantly induce apoptosis. Everolimus effectively blocked protein biosynthesis both in vitro and in a novel ex vivo tissue slice model using fresh vital human RCC tissue. Compared to other components of the mTOR pathway, phosphorylation of rpS6 was most effectively downregulated by everolimus. Importantly, siRNA-mediated downregulation of rpS6, but not of 4ebp1 or p27, abolished the inhibitory effects of everolimus on proliferation and protein synthesis. Moreover, we analyzed the tissue expression of phosphorylated rpS6 (p-rpS6) and non-phosphorylated rpS6 in a large collection of patients with RCCs (n=598 and n=548, respectively). Expression of both proteins qualified as independent negative prognostic markers with a substantially shorter survival of patients with RCCs exhibiting high levels of rpS6 and p-rpS6. Taken together, our functional studies identified rpS6 as a main mediator of the anti-tumoral activity of Everolimus. Therefore, further (pre-)clinical evaluations of rpS6 as a predictive marker for everolimus-based treatment for RCC patients are warranted. Finally, the combined detection of phosphorylated and non-phosphorylated rpS6 could represent a robust prognostic marker to identify patients with high risk RCCs.     

Aberrations of a cell adhesion molecule CADM4 in renal clear cell carcinoma

Renal clear cell carcinoma (RCCC) is the most frequent subpopulation of renal cell carcinoma and is derived from the proximal uriniferous tubules. We have previously reported that an actin-binding protein, 4.1B/DAL-1, is expressed in renal proximal tubules, whereas it is inactivated in 45% of RCCC by promoter methylation. In the lung and several epithelial tissues, 4.1B is shown to associate with a tumor suppressor protein, CADM1, belonging to the immunoglobulin-superfamily cell adhesion molecules. Here, we demonstrate by immunohistochemistry that another member of the CADM-family protein, CADM4, as well as 4.1B is expressed specifically in human proximal tubules, while CADM1 and 4.1N, another member of the 4.1 proteins, are expressed in the distal tubules. Immunoprecipitation analysis coupled with Western blotting revealed that CADM4 associated with 4.1B, while CADM1 associated with 4.1N in the lysate from normal human kidney, implicating that a cascade of CADM4 and 4.1B plays an important role in normal cell adhesion of the proximal tubules. On the other hand, CADM4 expression was lost or markedly reduced in 7 of 10 (70%) RCC cell lines and 28 of 40 (70%) surgically resected RCCC, including 10 of 16 (63%) tumors with T1a. CADM4 expression was more preferentially lost in RCCC with vascular infiltration (p = 0.04), suggesting that loss of CADM4 is involved in tumor invasion. Finally, introduction of CADM4 into an RCC cell line, 786-O, dramatically suppressed tumor formation in nude mice. These findings suggest that CADM4 is a novel tumor suppressor candidate in RCCC acting with its binding partner 4.1B.     

Annexin-1在肾细胞癌中的表达

目的:探讨肾细胞癌(renal cell carcinoma tissue,RCC)组织中Annexin-1的表达及意义。方法:应用免疫组织化学方法检测56例肾癌组织、20例癌旁组织和16例肾细胞组织中Annexin-1的表达情况。结果:肾癌组织、癌旁组织和肾细胞组织中Annexin-1的阳性表达率分别为21.43%(12/56)、35%(7/20)和81.25%(13/16)。结论:Annexin-1在肾癌组织、癌旁组织中的表达较肾细胞组织中的表达显著降低,检测Annexin-1有望为肾细胞癌的早期诊治提供理论依据。     

Annexin-1在肾细胞癌中的表达

目的：探讨肾细胞癌（renal cell carcinoma tissue,RCC）组织中Annexin-1的表达及意义。方法：应用免疫组织化学方法检测56例肾癌组织、20例癌旁组织和16例肾细胞组织中Annexin-1的表达情况。结果：肾癌组织、癌旁组织和肾细胞组织中Annexin-1的阳性表达率分别为21.43%（12/56）、35%（7/20）和81.25%（13/16）。结论：Annexin-1在肾癌组织、癌旁组织中的表达较肾细胞组织中的表达显著降低,检测Annexin-1有望为肾细胞癌的早期诊治提供理论依据。     

miR-27a下调肾癌细胞FOXO1表达并促进其细胞增殖

目的 探讨microRNA-27a(miR-27a)在肾癌细胞中的作用及调控机制.方法 应用miR-27a反义寡核苷酸(ASO)在体外转染786-O和Caki-1细胞;qRT-PCR法检测miR-27a及FOXO1 mRNA的表达情况,Western blot检测FOXO1蛋白的表达水平;CCK8检测miR-27a ASO对细胞增殖的影响.结果 786-O和Caki-1细胞中miR-27a表达高于HK2正常肾小管上皮细胞(P<0.05);利用miR-27a ASO抑制786-O和Caki-1细胞miR-27a表达后,发现两个细胞株FOXO1 mRNA和蛋白表达的升高及增殖能力的降低(P<0.05).结论 miR-27a 可能通过调控FOXO1表达在肾癌中起致癌作用.miR-27a ASO可抑制肾癌细胞的增殖,因此miR-27a有可能作为肾癌基因治疗的候选靶点.     

miR-27a下调肾癌细胞FOXO1表达并促进其细胞增殖

目的：探讨microRNA-27a（miR-27a）在肾癌细胞中的作用及调控机制。方法：应用miR-27a反义寡核苷酸（ASO）在体外转染786-O和Caki-1细胞;qRT-PCR法检测miR-27a及FOXO1 mRNA的表达情况,Western blot检测FOXO1蛋白的表达水平;CCK8检测miR-27a ASO对细胞增殖的影响。结果：786-O和Caki-1细胞中miR-27a表达高于HK2正常肾小管上皮细胞（P〈0.05）;利用miR-27a ASO抑制786-O和Caki-1细胞miR-27a表达后,发现两个细胞株FOXO1 mRNA和蛋白表达的升高及增殖能力的降低（P〈0.05）。结论：miR-27a可能通过调控FOXO1表达在肾癌中起致癌作用。miR-27a ASO可抑制肾癌细胞的增殖,因此miR-27a有可能作为肾癌基因治疗的候选靶点。