Suppression of MMP-9 activity by NDRG2 expression inhibits clear cell renal cell carcinoma invasion

Members of the NDRG (N-Myc downstream-regulated) gene family have been shown to play a variety of roles in human malignancies. Recently, it was shown decreased expression in clear cell renal cell carcinoma (CCRCC) and inhibited cell proliferation, but the role of the NDRG2 in CCRCC invasion has not been described. We examined the expression of NDRG2 protein in CCRCC samples and the association between NDRG2 expression and CCRCC patients survival. Real-time RT-PCR and immunohistochemical analysis were used to measure NDRG2 expression in 60 paired CCRCC and adjacent normal tissues. Changes in cell invasion were detected by up- or down-regulating NDRG2 by adenovirus or siRNA. We found that NDRG2 expression is significantly down-regulated in CCRCC at mRNA and protein levels in a manner negatively associated with aggressive tumor behaviors, such as TNM stage (P?=?0.003), Fuhrman??s grade (P?=?0.024), tumor invasion (P?=?0.001) and tumor recurrence (P?=?0.004), as well as shorter patient survival rates (P?=?0.0041). Furthermore, NDRG2 could suppress CCRCC cell invasion through regulating MMP-9 expression and activity. So, these results suggest that NDRG2 can inhibit extracellular matrix-based tumor cell invasion and thereby play important roles in suppressing tumor metastasis in CCRCC. NDRG2 expression may also be a significant prognostic indicator for CCRCC.     

MYC pathway is activated in clear cell renal cell carcinoma and essential for proliferation of clear cell renal cell carcinoma cells

Bone morphogenetic protein 7 (BMP7) is a signaling molecule originally identified based on its ability to form bone. It is essential during development, and more recently has also been implicated in cancer pathogenesis. We have recently shown that BMP7 is overexpressed in breast cancer, and that this increased expression is associated with early bone metastasis formation. In the present study, we explored the possible contribution of BMP7 function to the breast cancer cell phenotype. A two-way approach was applied in which BMP7 was silenced using RNA interference in three cell lines with high endogenous expression or, conversely, exogenous BMP7 was added to the growth medium of five cell lines with low or no BMP7 expression. These manipulations led to diverse cell line-specific phenotypic responses. BMP7 manipulation increased cell growth in two cell lines (BT-474, MDA-MB-231), and BMP7 treatment led to reduced growth in four cell lines (HCC1954, MDA-MB-361, T-47D, and ZR-75-30). Growth changes were due to distinct mechanisms since BMP7 silencing led to growth inhibition via G1 arrest in BT-474 cells, whereas BMP7 treatment protected MDA-MB-231 cells from apoptosis. Furthermore, BMP7 stimulation altered the MDA-MB-231 phenotype by inducing a distinct 2.3-fold increase in cell migration and an even more dramatic 3.9-fold increase in cell invasion. In conclusion, BMP7 can promote and inhibit cell growth in breast cancer cell lines and, in a suitable environment, can also considerably induce breast cancer cell migration and invasion.     

MYC pathway is activated in clear cell renal cell carcinoma and essential for proliferation of clear cell renal cell carcinoma cells

Clear cell renal cell carcinoma (ccRCC) is the major and aggressive subtype of RCC. Previously, we identified 383 differentially expressed genes by analyzing full-length cDNA libraries of ccRCC and normal kidney tissues. In this study, we applied functional network analysis to the differentially expressed genes for identifying deregulated molecular pathways in ccRCC, and the results indicated that MYC showed a prominent role in the highest scoring network. The upregulation of MYC expression was validated in ccRCC tissues and cell lines. Furthermore, Knockdown of MYC expression by MYC-specific siRNA significantly inhibited the abilities of uncontrolled proliferation, anchorage-independent growth and arrested cell cycle in the G0/G1 phase in ccRCC cells. Moreover, we found that 37 differentially expressed genes were shown to be MYC-target genes, and the upregulation of the MYC-target genes BCL2, CCND1, PCNA, PGK1, and VEGFA were demonstrated. The expression of these MYC-target genes was significantly correlated with the expression of MYC in ccRCC tissues, and knockdown of MYC also suppressed the expression of these MYC-target genes in ccRCC cells. The recruitment of MYC to the promoter regions of BCL2, CCND1, PCNA, PGK1, and VEGFA was shown by Chromatin immunoprecipitation assay. These results suggest that MYC pathway is activated and plays an essential role in the proliferation of ccRCC cells.     

沉默EMMPRIN对肾透明细胞癌增殖的影响

目的:探讨细胞外基质金属蛋白酶诱导因子（EMMPRIN）在肾透明细胞癌增殖中的作用。方法:利用免疫组化、实时定量PCR(RT-PCR)和蛋白印迹(Western blot)等方法检测肾癌组织与肾透明细胞癌细胞株中EMMPRIN的表达情况。通过小分子干扰核糖核酸（siRNA）EMMPRIN在786-O细胞中的表达,研究EMMPRIN下调后对786-O肾癌细胞株生物学功能的影响。结果:EMMPRIN在肾癌组织中高表达,肾癌细胞系中EMMPRIN的表达高于正常的肾小管上皮细胞。通过小干扰RNA来敲除EMMPRIN的表达,并影响肾透明细胞癌的增殖。结论:EMMPRIN在肾肿瘤组织和肾癌细胞株中皆呈现出过表达的状态。下调其表达可以降低肾细胞癌的增殖水平,表明EMMPRIN的高表达可能是肾细胞癌患者预后较差的指标,可被视为肾癌治疗的潜在靶点。     

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.     

miR-1271-5p在肾细胞癌组织和细胞中的表达及其对A-498 细胞增殖及凋亡的影响

目的:探讨miR-1271-5p 在肾细胞癌（renal cell carcinoma,RCC）组织和细胞系中的表达及其对RCC细胞株A-498 增殖及凋亡的影响。方法：用实时荧光定量PCR（qPCR）检测手术切除并经病理确诊为RCC组织和癌旁组织,以及RCC细胞系ACHN、A498、HK-2、786-O、CaKi-1 和人胚肾细胞株HEK293 中miR-1271-5p 的表达水平。用miR-1271-5p（实验组）和miR-NC（对照组）分别转染A-498 细胞。通过生物信息学预测鸟嘌呤交换因子DOCK1 为miR-1271-5p 可能的靶基因,构建DOCK1 基因的3’UTR 野生型及突变体序列双荧光素酶报告基因载体并进行荧光素酶活性检测,qPCR检测两组细胞中DOCK1 mRNA表达水平,Western blotting 检测两组细胞中DOCK1、p-ERK、p-AKT、Bcl-2 和Bax蛋白的表达情况,MTS法、集落形成实验和流式细胞术检测A-489 细胞增殖、集落形成数目和凋亡情况。结果：RCC组织和细胞系中miR-1271-5p 表达水平显著低于癌旁组织和人胚肾HEK293 细胞（均P<0.01）。双荧光素酶报告基因系统结果显示DOCK1 是miR-1271-5p 的靶基因(P<0.01)。与miR-NC组细胞相比,miR-1271-5p 组A-498 细胞中DOCK1 mRNA的表达水平显著下降(P<0.01);DOCK1、p-ERK、p-AKT、Bcl-2 蛋白表达水平显著下调(P<0.05),Bax 蛋白明显上调(P<0.05);A-498 细胞增殖活力显著降低(P<0.01);集落形成数显著减少(P<0.05);细胞凋亡率显著增高(P<0.01)。结论：RCC组织和细胞系中miR-1271-5p 表达下调,通过干扰DOCK1 基因表达能明显抑制A-489 细胞的增殖及诱导其凋亡,miR-1271-5p 可能成为未来RCC治疗的分子靶标。     

Sirtuin 6 regulates the proliferation and survival of clear cell renal cell carcinoma cells via B-cell lymphoma 2

Sirtuin 6 (SIRT6) is a member of the third family of longevity proteins (SIRTs) that is involved in the development of different types of cancer. However, the potential role of SIRT6 in clear cell renal cell carcinoma (ccRCC) and its molecular mechanism have not yet been fully elucidated. Therefore, the present study aimed to investigate the association between SIRT6 and ccRCC, and to further examine the underlying mechanism of its effect on ccRCC proliferation, using bioinformatics analysis, and in vitro and in vivo experiments. The results of the present study demonstrated that SIRT6 was upregulated in ccRCC tissues. In addition, bioinformatics analysis revealed that high SIRT6 expression was closely associated with poor prognosis of patients with ccRCC. In vitro experiments demonstrated that silencing SIRT6 expression in ccRCC-derived 769-P and 786-O cells significantly inhibited their proliferation, migration and invasion. Consistent with these results, in vivo assays demonstrated that SIRT6 knockdown markedly attenuated tumor growth arising from 769-P cells. Furthermore, depletion of SIRT6 enhanced the sensitivity of ccRCC cells to cisplatin. Notably, silencing SIRT6 expression decreased B-cell lymphoma 2 (Bcl-2) expression and increased Bax expression, respectively. Taken together, these results suggest that SIRT6 acts as a proto-oncogene in ccRCC through the augmentation of the Bcl-2-dependent pro-survival pathway, and may be used as a therapeutic target for patients with ccRCC.     

肾透明细胞癌组织SMO表达与肾癌细胞增殖和凋亡的相关性

目的 Hedgehog信号通路参与了肿瘤的发生发展,本研究探讨该通路关键信号分子Smoothened(SMO)在肾透明细胞癌中的表达及对肾癌细胞增殖和凋亡的影响.方法 选取2012-01-01-2013-06-30青岛大学附属医院泌尿外科,行手术治疗的80例肾透明细胞癌患者的临床及病理资料,采用免疫组织化学方法检测SMO在肾透明细胞癌组织中的表达并分析其与临床病理特征间的关系.采用小干扰RNA下调SMO在人肾癌细胞786-O中的表达,分别应用CCK-8法、流式细胞术及蛋白质印迹法检测下调SMO表达对细胞增殖、凋亡及Gli1和Gli2表达的影响.结果 SMO在73例(91.25％)肾透明细胞癌组织中有表达,其在高级别肾癌中表达(80.49％)较低级别(56.41％)显著升高,x2 =5.39,P=0.02.RT-PCR 检测结果显示,SMO在人肾癌细胞系786-O中表达量为0.704±0.059;蛋白质印迹结果显示,SMO在786-O中表达量为0.651±0.074.在786-O细胞中应用小干扰RNA沉默SMO表达后,实验组细胞相较于对照组其活力百分比在48、72和96 h分别为92.7％、80.9％和79.9％,3个时间点差异有统计学意义(P=0.003),细胞凋亡显著增加,t=-29.2,P＜0.001;与空白对照组和阴性对照组相比,其下游分子Gli1和Gli2蛋白表达明显减少(Gli1:3.2 vs 2.9 vs1;Gli2:2.5 vs 2.1vs 1).结论 SMO可能通过调控细胞增殖和凋亡,以及调节Gli蛋白表达参与了肾癌的发生发展.     

Biomarkers in clear cell renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has evolved significantly following the identification of the von Hippel–Lindau (VHL) gene and the function of its protein, and subsequent development of antiangiogenic therapies. A series of clinical trials resulted in the approval of three new agents with significant activity in this disease. Additional studies are now underway to identify subsets of patients most likely to benefit. This article reviews the current therapy for advanced RCC and the development of biomarkers in RCC. This requires the identification of disease characteristics at a clinical, genetic and molecular level associated with response and/or surrogate measures of clinical benefit. Currently, a variety of prognostic factors (lactate dehydrogenase, performance status, disease-free interval, hemoglobin and calcium levels) are utilized to predict the survival of RCC patients. The use of validated biomarkers in either serum/plasma, urine or tissue could enhance this process, as well as define at the molecular and genetic levels, factors associated with response to therapy and/or the development of resistance. Examples include plasma VEGF levels, VHL gene mutation status and carbonic anhydrase IX levels in tumor tissue, among others. Validation of such biomarkers is crucial in order for them to be clinically useful.     

Biomarkers in clear cell renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has evolved significantly following the identification of the von Hippel-Lindau (VHL) gene and the function of its protein, and subsequent development of antiangiogenic therapies. A series of clinical trials resulted in the approval of three new agents with significant activity in this disease. Additional studies are now underway to identify subsets of patients most likely to benefit. This article reviews the current therapy for advanced RCC and the development of biomarkers in RCC. This requires the identification of disease characteristics at a clinical, genetic and molecular level associated with response and/or surrogate measures of clinical benefit. Currently, a variety of prognostic factors (lactate dehydrogenase, performance status, disease-free interval, hemoglobin and calcium levels) are utilized to predict the survival of RCC patients. The use of validated biomarkers in either serum/plasma, urine or tissue could enhance this process, as well as define at the molecular and genetic levels, factors associated with response to therapy and/or the development of resistance. Examples include plasma VEGF levels, VHL gene mutation status and carbonic anhydrase IX levels in tumor tissue, among others. Validation of such biomarkers is crucial in order for them to be clinically useful.     

透明细胞乳头状肾细胞癌临床病理特征分析

目的:探讨透明细胞乳头状肾细胞癌（CCPRCC）的临床及病理学特征。方法:回顾性分析6例CCPRCC的临床特征、组织学特点及免疫表型,并复习相关文献。结果:6例肿瘤均位于肾皮质内,肿瘤边界清晰,有纤维性包膜,切面灰红或灰黄色,部分呈囊性改变。镜下肿瘤呈乳头状、管状、囊性及实性混合性生长,胞浆透明,细胞核远离基底膜,世界卫生组织（World Health Organization,WHO）/国际泌尿病理协会（International Society of Urological Pathology,ISUP)分级为1级或2级。免疫表型:6例肿瘤组织均表达CK7、PAX-8和34βE12,CAIX呈“杯状”或完全膜阳性表达。1例CD10部分阳性,其余5例CD10阴性。所有病例AMACR和TFE3均为阴性。结论:透明细胞乳头状肾细胞癌是一种少见的肾肿瘤,呈惰性生物学行为。形态上应与具有透明细胞和乳头状结构的肾细胞癌鉴别,可借助免疫组织化学和分子遗传学检测予以鉴别。     

The renal clear cell carcinoma immune landscape

A comprehensive evaluation of the clear cell renal cell carcinoma (ccRCC) immune landscape was found using 584 RNA-sequencing datasets from The Cancer Genome Atlas (TCGA), we identified 17 key dysregulated immune-associated genes in ccRCC based on association with clinical variables and important immune pathways. Of the numerous findings from our analyses, we found that several of the 17 key dysregulated genes are heavily involved in interleukin and NF-kB signaling and that somatic copy number alteration (SCNA) hotspots may be causally associated with gene dysregulation. More importantly, we also found that key immune-associated genes and pathways are strongly upregulated in ccRCC. Our study may lend novel insights into the clinical implications of immune dysregulation in ccRCC and suggests potential immunotherapeutic targets for further evaluation.     

Transmembrane protein ADAM29 facilitates cell proliferation,invasion and migration in clear cell renal cell carcinoma

Abnormal expression of ADAM29 has been frequently reported in several cancers, however, its role in clear cell renal cell carcinoma (ccRCC) has not evaluated in detail. Herein, we attempt to determine the biological role and the action mechanism of ADAM29 in ccRCC. Bioinformatics analysis based on the ccRCC RNA-Seq dataset from TCGA database revealed that ADAM29 was up-expressed in ccRCC tissues by comparison with normal tissues. And a significant increase of ADAM29 expression was also observed in 3 ccRCC cell lines (UT33A, Caki-1, and786-O) in comparison with normal cell line. Besides, high level of ADAM29 was found to be connected with the poor prognosis and could be considered as an independent prognosticator for patients with ccRCC. Furthermore, functional experiments in vitro demonstrated that ADAM29 promoted the growth, invasion and migration of ccRCC cells. Moreover, Western blot assays indicated that ADAM29 was positively correlated with the level of proliferation-related proteins Cyclin D1 and PCNA and motion-related proteins MMP9 and Snail. Our data indicate that ADAM29 acts as an oncogene that increases tumour cells proliferation, invasion and migration partly by regulating the expression of Cyclin D1/PCNA/MMP9/Snail, suggesting that ADAM29 may become a prognosticator and therapeutic candidate for ccRCC.     

Impaired expression of the cell cycle regulator BTG2 is common in clear cell renal cell carcinoma

The prognosis of patients with renal cell carcinoma (RCC) is poor. A full understanding of the molecular genetics and signaling pathways involved in renal cancer development and in the metastatic process is of central importance for developing innovative and novel treatment options. In this study, BD Atlas Human Cancer 1.2 cDNA microarrays were used to identify genes involved in renal tumorigenesis. By analyzing gene expression patterns of four clear cell RCC (cRCC) cell lines and normal renal tissue, 25 genes were found differentially expressed. To determine the relevance of these genes, RNA in situ hybridization was performed on a tissue microarray generated from 61 snap-frozen primary renal cell carcinomas and 12 normal renal cortex biopsies. B-cell translocation gene 2 (BTG2), a negative cell cycle regulator, which was expressed in normal renal tissue but down-regulated in cRCC cell lines and primary cRCCs, was selected for additional experiments. Quantitative BTG2 mRNA expression analysis in 42 primary cRCCs and 18 normal renal cortex biopsies revealed up to 44-fold reduced expression in the tumor tissues. Decrease of BTG2 expression was not associated with tumor stage, grade, and survival. Cell culture experiments demonstrated that BTG2 expression was weakly inducible by the phorbolester 12-O-tetradecanoylphorbol-13-acetate in one of four cRCC cell lines. In contrast, increasing cell density led to elevated BTG2 mRNA expression in three of four cRCC cell lines. In both experiments, BTG2 mRNA levels did not reach values observed in normal renal tissue. These data suggest that down-regulation of BTG2 is an important step in renal cancer development.     

Combination drug regimens for metastatic clear cell renal cell carcinoma

Renal cell carcinomas (RCC) make up about 90% of kidney cancers, of which 80% are of the clear cell subtype. About 20% of patients are already metastatic at the time of diagnosis. Initial treatment is often cytoreductive nephrectomy, but systemic therapy is required for advanced RCC. Single agent targeted therapies are moderately toxic and only somewhat effective, leading to development of immunotherapies and combination therapies. This review identifies limitations of monotherapies for metastatic renal cell carcinoma, discusses recent advances in combination therapies, and highlights therapeutic options under development. The goal behind combining various modalities of systemic therapy is to potentiate a synergistic antitumor effect. However, combining targeted therapies may cause increased toxicity. The initial attempts to create therapeutic combinations based on inhibition of the vascular endothelial growth factor or mammalian target of rapamycin pathways were largely unsuccessful in achieving a profile of increased synergy without increased toxicity. To date, five combination therapies have been approved by the U.S. Food and Drug Administration, with the most recently approved therapies being a combination of checkpoint inhibition plus targeted therapy. Several other combination therapies are under development, including some in the phase 3 stage. The new wave of combination therapies for metastatic RCC has the potential to increase response rates and improve survival outcomes while maintaining tolerable side effect profiles.     

Expression of NDRG2 in esophageal squamous cell carcinoma

N‐Myc downstream‐regulated gene 2 (NDRG2), a new member of the N‐Myc downstream‐regulated gene family, has been found to be a differentially expressed gene involved in a variety of cancers. The present study aimed to investigate the expression of NDRG2 in esophageal squamous cell carcinoma (ESCC). Immunohistochemistry was performed in 154 samples from patients with ESCC to detect the expression level of NDRG2 and C‐MYC. Results indicated that the expression level of NDRG2 in the cancer samples was significantly lower than that in normal tissues; the trend of C‐MYC was the reverse. The Wilcoxon–Mann–Whitney test showed significant difference in the expression of NDRG2 in patients with different T stage, TNM stage, and differentiation degree of cancers (P = 0.036, 0.031, 0.001, respectively). Patients in stages I and II were followed up for 5 consecutive years and Kaplan–Meier survival analysis demonstrated that the survival time of ESCC patients with high expression of NDRG2 was longer than those with low expression during the 5‐year follow‐up period (P = 0.0018). Cox regression analysis indicated that low expression of NDRG2, cancer stage of pT1, and distant organ metastasis (pM1) were the independent poor prognostic factors of ESCC (P = 0.004, 0.019, 0.0013, respectively). Furthermore, up‐regulation of NDRG2 was introduced to ESCC cell lines (EC9706 and EC109) by plasmid transfection. In vivo and in vitro studies indicated that overexpression of NDRG2 markedly reduced proliferation and promoted the apoptosis of EC9706 and EC109 cells. In summary, our results demonstrated that NDRG2 played an important role in the proliferation of ESCC cells and the expression of NDRG2 in ESCC was closely related with the prognosis. (Cancer Sci 2010; 101: 1292–1299)