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Long noncoding RNAs (lncRNAs) serve pivotal roles in cancer biology. The present study investigated the oncogenic roles of lncRNAs in renal cell carcinoma (RCC) and their potential as prognostic biomarkers. The lncRNA leucine‑rich repeat containing 75 A‑antisense RNA1 (LRRC75A‑AS1) was identified through lncRNA microarray as a potential lncRNA that may predict the efficacy of immune checkpoint inhibitor therapy and cancer progression in RCC. The present study subsequently assessed the expression of LRRC75A‑AS1 in 212 patients with clear cell RCC (ccRCC) who underwent nephrectomy, and performed in vitro functional analysis of LRRC75A‑AS1 in RCC cell lines. Additionally, the interactions between LRRC75A‑AS1, microRNA (miR)‑370‑5p and ADAMTS5 were explored. LRRC75A‑AS1 was revealed to be significantly upregulated in ccRCC tissues compared with in adjacent normal tissues, and high LRRC75A‑AS1 expression was associated with poor prognosis, including lower progression‑free survival, in patients with RCC. The knockdown of LRRC75A‑AS1 in RCC cell lines resulted in reduced cell proliferation and invasion, highlighting its role in promoting tumorigenesis. Furthermore, the interaction among LRRC75A‑AS1, miR‑370‑5p and ADAMTS5 was suggested as a regulatory mechanism underlying RCC progression. These findings indicated that LRRC75A‑AS1 may function as an oncogene in RCC, promoting cell proliferation and invasion. Its significant upregulation in ccRCC tissues and association with poor prognosis underscore its potential as a prognostic biomarker for RCC. Understanding the regulatory interactions among LRRC75A‑AS1, miR‑370‑5p and ADAMTS5 may provide new insights into the molecular mechanisms underlying RCC and facilitate the identification of novel therapeutic targets.

Although axitinib shows a good objective response rate and acceptable tolerability for advanced renal cell carcinoma, substantial differences in drug concentrations among individuals have hampered the reliable administration of the drug in a neoadjuvant setting. This study aimed to evaluate the relationship between axitinib pharmacokinetics and clinical efficacy in patients with advanced renal cell carcinoma treated in a neoadjuvant setting. We retrospectively reviewed 16 patients who underwent neoadjuvant axitinib treatment from prospective phase 2 study cohorts treated with axitinib and assessed whether the drug concentration was associated with clinical efficacy for primary tumors of advanced metastatic/oligometastatic clear cell renal cell carcinoma. Axitinib was administered orally at a starting dose of 5 mg twice daily for 2 months in principle before the operation, and the axitinib pharmacokinetics were examined. Best response, reduction rate, adverse events (AEs), and surgical complication were assessed. Four patients (25.0%) showed a partial response, and 12 (75.0%) had stable disease, with a mean reduction rate of 22.8%. No progressive disease was noted, and 9 of the 16 patinets (56.3%) showed downstaging. The trough level of axitinib significantly correlated with the objective response rate (P = .0052) and best tumor reduction (P = .0128). All AEs could be safely managed until termination of the dosing period. With respect to perioperative complications, grade 2 anemia was observed. Neoadjuvant axitinib treatment showed acceptable antitumor activity and safety profile for advanced renal cell carcinoma. The pharmacokinetics of neoadjuvant axitinib influenced the efficacy in patients with advanced renal cell carcinoma., (© 2019, The American College of Clinical Pharmacology.)

Background: Cytochrome P450 1B1 (CYP1B1) has been shown to be up-regulated in many types of cancer including renal cell carcinoma (RCC). Several reports have shown that CYP1B1 can influence the regulation of tumor development; however, its role in RCC has not been well investigated. The aim of the present study was to determine the functional effects of CYP1B1 gene on tumorigenesis in RCC., Methods: Expression of CYP1B1 was determined in RCC cell lines, and tissue microarrays of 96 RCC and 25 normal tissues. To determine the biological significance of CYP1B1 in RCC progression, we silenced the gene in Caki-1 and 769-P cells by RNA interference and performed various functional analyses., Results: First, we confirmed that CYP1B1 protein expression was significantly higher in RCC cell lines compared to normal kidney tissue. This trend was also observed in RCC samples (p < 0.01). Interestingly, CYP1B1 expression was associated with tumor grade and stage. Next, we silenced the gene in Caki-1 and 769-P cells by RNA interference and performed various functional analyses to determine the biological significance of CYP1B1 in RCC progression. Inhibition of CYP1B1 expression resulted in decreased cell proliferation, migration and invasion of RCC cells. In addition, reduction of CYP1B1 induced cellular apoptosis in Caki-1. We also found that these anti-tumor effects on RCC cells caused by CYP1B1 depletion may be due to alteration of CDC20 and DAPK1 expression based on gene microarray and confirmed by real-time PCR. Interestingly, CYP1B1 expression was associated with CDC20 and DAPK1 expression in clinical samples., Conclusions: CYP1B1 may promote RCC development by inducing CDC20 expression and inhibiting apoptosis through the down-regulation of DAPK1. Our results demonstrate that CYP1B1 can be a potential tumor biomarker and a target for anticancer therapy in RCC.

We investigated whether impaired regulation of bone morphogenetic protein-2 (BMP-2) via epigenetic pathways is associated with renal cell carcinoma (RCC) pathogenesis. Expression and CpG methylation of the BMP-2 gene were analyzed using RCC cell lines, and 96 matched RCC and normal renal tissues. We also performed functional analysis using BMP-2 restored RCC cells. A significant association of BMP-2 mRNA expression was also found with advanced tumor stage and lymph node involvement, while lower BMP-2 mRNA expression was significantly associated with poor overall survival after radical nephrectomy. In RCC cells, BMP-2 restoration significantly inhibited cell proliferation, migration, invasion, and colony formation. In addition, BMP-2 overexpression induced p21(WAF1/CIP1) and p27(KIP1) expression, and cellular apoptosis in RCC cells. BMP-2 mRNA expression was significantly enhanced in RCC cells by 5-aza-2'-deoxycitidine treatment. The prevalence of BMP-2 promoter methylation was significantly greater and BMP-2 mRNA expression was significantly lower in RCC samples as compared to normal kidney samples. Furthermore, a significant correlation was found between BMP-2 promoter methylation and mRNA transcription in tumors. Aberrant BMP-2 methylation and the resultant loss of BMP-2 expression may be a useful molecular marker for designing improved diagnostic and therapeutic strategies for RCC.

Recently, long noncoding RNAs (lncRNA) have emerged as new gene regulators and prognostic markers in several cancers, including renal cell carcinoma (RCC). In this study, we investigated the contributions of the lncRNA MALAT1 in RCC with a specific focus on its transcriptional regulation and its interactions with Ezh2 and miR-205. We found that MALAT1 expression was higher in human RCC tissues, where it was associated with reduced patient survival. MALAT1 silencing decreased RCC cell proliferation and invasion and increased apoptosis. Mechanistic investigations showed that MALAT1 was transcriptionally activated by c-Fos and that it interacted with Ezh2. After MALAT1 silencing, E-cadherin expression was increased, whereas β-catenin expression was decreased through Ezh2. Reciprocal interaction between MALAT1 and miR-205 was also observed. Lastly, MALAT1 bound Ezh2 and oncogenesis facilitated by MALAT1 was inhibited by Ezh2 depletion, thereby blocking epithelial-mesenchymal transition via E-cadherin recovery and β-catenin downregulation. Overall, our findings illuminate how overexpression of MALAT1 confers an oncogenic function in RCC that may offer a novel theranostic marker in this disease., (©2015 American Association for Cancer Research.)

The cytochrome P450 1B1 (CYP1B1) enzyme activates xenobiotics to reactive forms as well as convert estradiol to 4-hydroxy-estradiol that has been shown to play a role in the carcinogenesis process of the kidney in male but not female animals. Prior reports show polymorphic variants of CYP1B1 to alter catalytic activity, and thus, we hypothesize that polymorphisms of the CYP1B1 gene are involved in the malignant transformation of the renal cell in men. The genetic distributions of five CYP1B1 polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism in 480 normal healthy subjects and 403 sporadic renal cell carcinoma cases. All subjects were Caucasian men. The sites evaluated were codons 48 (C → G, Arg → Gly, rs10012), 119 (G → T, Ala → Ser, rs1056827), 432 (C → G, Leu → Val, rs1056836), 449 (C → T, Asp, rs1056837), and 453 (A → G, Asn → Ser, rs1800440). A trend was demonstrated for the 432 Val/Val (χ2, P = 0.06) and 449 T/T (χ2, P = 0.1) genotypes to play a protective role against renal cancer. Odds ratio (95 % confidence interval) for Val/Val compared to Leu/Leu at codon 432 was 0.65 (0.44-0.95) and T/T compared to C/C at codon 449 was 0.67 (0.45-0.99). Codons 432 and 449 were observed to be linked (D = 0.24), and haplotype involving 432 Val and 449 T was significantly reduced in cancer cases (P = 0.04). No association was found, however, when analyzing polymorphic sites with clinical stage of cancer. These results demonstrate polymorphisms of CYP1B1 to be associated with renal carcinogenesis and are of importance in understanding their role in the pathogenesis of renal cell carcinoma.

Background: Wnt-signalling has an important role in renal cancer and it is modulated by genistein in other cancers. Recently, microRNAs (miRNAs) have emerged as new regulators of gene expression. Thus, we focused on miRNAs to examine the regulatory mechanism of genistein on the Wnt-signalling pathway in renal cell carcinoma (RCC)., Methods: Initially, we investigated the effect of genistein on Wnt-signalling (TOPflash reporter assay (TCF reporter assays)) in renal cancer cells, and using microarray identified candidate miRNAs whose expression was decreased by genistein. We performed functional analyses and investigated the relationship between miRNA expression and renal cancer patient outcomes. We also did 3'UTR luciferase assays to look at direct miRNA regulation of Wnt-signalling-related genes., Results: Genistein promoted apoptosis while inhibiting RCC cell proliferation and invasion. Genistein also decreased TCF reporter activity in RCC cells. We found that miR-1260b was highly expressed and significantly downregulated by genistein in RCC cells. The expression of miR-1260b was significantly higher in renal cancer tissues compared with normal, and significantly related to overall shorter survival. In addition, miR-1260b promoted renal cancer cell proliferation and invasion in RCC cells. The 3'UTR luciferase activity of target genes (sFRP1, Dkk2, Smad4) was significantly decreased and their protein expression significantly upregulated in miR-1260b inhibitor-transfected renal cancer cells., Conclusion: Our data suggest that genistein inhibited Wnt-signalling by regulating miR-1260b expression in renal cancer cells.

The aim of this project is to identify new therapeutic microRNAs (miRNAs) for von Hippel-Lindau (VHL)-inactivated renal cancer cells. We initially identified several potential miRNAs targeting CTNNB1 and MEK1 using several targets scan algorithms. Only miR-1826 was found to target CTNNB1 and MEK1. Therefore, we focused on miRNA-1826 and performed 3' untranslated region (UTR) luciferase assay, functional analyses and association study between miR-1826 expression and renal cancer patient outcomes. miR-1826 expression was significantly lower in renal cancer tissues compared with non-neoplastic areas and lower expression was significantly associated with overall shorter survival and earlier recurrence after radical nephrectomy. Following miR-1826 transfection, 3' UTR luciferase activity and protein expression of beta-catenin and MEK1 were significantly downregulated in renal cancer cells. Introduction of miR-1826 also inhibited renal cancer cell proliferation, invasion and migration. Additionally, miR-1826 promoted apoptosis and G(1) arrest in VHL-inactivated renal cancer cells. Knockdowns of CTNNB1 and MEK1 by small interfering RNAs reproduced the tumor-suppressive effect of miR-1826. Our data suggest that the miR-1826 plays an important role as a tumor suppressor by downregulating beta-catenin and MEK1 in VHL-inactivated renal cancers.

We investigated the functional effects of microRNA-34a (miR-34a) on c-Myc transcriptional complexes in renal cell carcinoma. miR-34a down-regulated expression of multiple oncogenes including c-Myc by targeting its 3' untranslated region, which was revealed by luciferase reporter assays. miR-34a was also found to repress RhoA expression by suppressing the c-Myc-Skp2-Miz1 transcriptional complex that activates RhoA. Overexpression of c-Myc reversed miR-34a suppression of RhoA expression and inhibition of cell invasion, suggesting that miR-34a inhibits invasion by suppressing RhoA through c-Myc. miR-34a was also found to repress the c-Myc-P-TEFb transcription elongation complex, indicating one of the mechanisms by which miR-34a has profound effects on cellular functions. Our results demonstrate that miR-34a suppresses assembly and function of the c-Myc complex that activates or elongates transcription, indicating a novel role of miR-34a in the regulation of transcription by c-Myc.

Background: miR-23b is located on chromosome number 9 and plays different roles in different organs especially with regards to cancer development. However, the functional significance of miR-23b-3p in renal cell carcinoma (RCC) has not been reported., Methods and Results: We measured miR-23b-3p levels in 29 pairs of renal cell carcinoma and their normal matched tissues using real-time PCR. The expression level of miR-23b-3p was correlated with the 5 year survival rate of renal cancer patients. In 15 cases (52%), miR-23b-3p expression was found to be high. All patients with moderate to low miR-23b-3p expression survived 5 years, while those with high miR-23b-3p expression, only 50% survived. After knocking down miRNA-23b-3p expression in RCC cell lines, there was an induction of apoptosis and reduced invasive capabilities. MiR-23b-3p was shown to directly target PTEN gene through 3'UTR reporter assays. Inhibition of miR-23b-3p induces PTEN gene expression with a concomitant reduction in PI3-kinase, total Akt and IL-32. Immunohistochemistry showed the lack of PTEN protein expression in cancerous regions of tissue samples where the expression of miR-23b-3p was high. We studied the in vitro effects of the dietary chemo preventive agent genistein on miR-23b-3p expression and found that it inhibited expression of miR-23b-3p in RCC cell lines., Conclusions: The current study shows that miR-23b-3p is an oncogenic miRNA and inhibits PTEN tumor suppressor gene in RCC. Therefore, inhibition of miR-23b-3p may be a useful therapeutic target for the treatment of renal cell carcinoma.

Background: MicroRNA-21 is up-regulated in a variety of cancers like, breast, colorectal, lung, head and neck etc. However, the regulation of miR-21 in renal cell carcinoma (RCC) has not yet been studied systematically., Methods and Results: We measured miR-21 levels in 54 pairs of kidney cancers and their normal matched tissues by real-time PCR. The expression level of miR-21 was correlated with 5 year survival and the pathological stage. Functional studies were done after inhibiting miR-21 in RCC cell lines. We studied in vitro and in vivo effects of the chemo preventive agent genistein on miR-21 expression. In 48 cases (90%), miR-21 was increased. All patients with low miR-21 expression survived 5 years, while with high miR-21 expression, only 50% survived. Higher expression of miR-21 is associated with an increase in the stage of renal cancer. Functional studies after inhibiting miRNA-21 in RCC cell lines show cell cycle arrest, induction of apoptosis and reduced invasive and migratory capabilities. Western blot analysis showed an increase in the expression of p21 and p38 MAP kinase genes and a reduction in cyclin E2. Genistein inhibited the expression of miR-21 in A-498 cells and in the tumors formed after injecting genistein treated A-498 cells in nude mice besides inhibiting tumor formation., Conclusions: The current study shows a clear correlation between miR-21 expression and clinical characteristics of renal cancer. Thus we believe that miR-21 can be used as a tumor marker and its inhibition may prove to be useful in controlling cancers with up-regulated miR-21.

Cancer pathogenesis is restricted by stresses that compromise cell division and survival. In this study, we identify miR-708, a little studied member of a set of microRNAs that have been implicated in stress control, as an important tumor suppressor in renal cell carcinoma (RCC). miR-708 expression was attenuated widely in human RCC specimens. Restoration of miR-708 expression in RCC cell lines decreased cell growth, clonability, invasion, and migration and elicited a dramatic increase in apoptosis. Moreover, intratumoral delivery of miR-708 was sufficient to trigger in vivo regression of established tumors in murine xenograft models of human RCC. Investigation of the targets of miR-708 identified the inhibitor of apoptosis protein survivin as important. siRNA-mediated knockdown of survivin partially phenocopied miR-708 overexpression suggesting that the proapoptotic role of miR-708 may be mediated primarily through survivin regulation. Additionally, we identified the E-cadherin regulators ZEB2 and BMI1 as likely miR-708 targets. Taken together, our findings define a major tumor suppressive role for miR-708, which may offer an attractive new target for prognostic and therapeutic intervention in RCC.

The Wnt signaling pathway is activated in most cancers while Wnt antagonist genes are inactivated. However, the functional significance and mechanisms of inactivation of Wnt antagonist Dkk-3 gene in renal cell carcinoma (RCC) has not been reported. In this study, we examined potential epigenetic mechanisms regulating Dkk-3 expression in RCC cells and whether Dkk-3 expression affects cell growth and apoptosis. The expression of Dkk-3 is regulated by histone modification rather than CpG island DNA methylation in renal cancer cells. Renal cancer cell proliferation was significantly inhibited and apoptosis was promoted in Dkk-3 transfected renal cancer cells. Dkk-3 did not inhibit the Wnt/beta-catenin signaling pathway but induced apoptosis via the noncanonical JNK pathway in renal cancer cells. Expression of p21, MDM-2, and Puma genes were increased after transfecting RCC cell lines with a Dkk-3 expression plasmid. Overexpression of Dkk-3 induced G(0)/G(1) arrest together with an increase in p21 expression. Growth of stable Dkk-3 transfected cells in nude mice was decreased compared to controls. Our data show for the first time that mRNA expression of Dkk-3 is regulated by histone modification and that Dkk-3 inhibits renal cancer growth through modulation of cell cycle and apoptotic pathways., (Copyright © 2011 Wiley-Liss, Inc.)

The functional significance of Wnt antagonist DKK1 has not been investigated in renal cell carcinoma (RCC). Therefore, we hypothesized that DKK1 may be a tumor suppressor gene and is epigenetically silenced, thus decreased DKK1 may cause progression of RCC. To assess the function of DKK1, we established stable DKK1 transfected cells and monitored them regarding cell viability, colony formation, apoptosis, cell cycle, and invasive capability. RCC cell lines had decreased levels of DKK1, which were increased after treatment with 5-Aza-2'-deoxycytidine and trichostatin A. In chromatin immunoprecipitation assay, the level of dimethyl H3K9 and trimethyl H3K27 was decreased after 5-Aza-2'-deoxycytidine/trichostatin A treatment in RCC cell lines. Increased methylation was also associated with higher pathological stages in primary RCC tissues. T-cell factor/lymphoid enhancer factor activity and nuclear beta-catenin expression were not changed in DKK1 transfectants. Also the expression of cyclinD1 and c-Myc was not changed in DKK1 transfectants. These results suggest that DKK1 may not be involved in the beta-catenin dependent pathway. We also evaluated the expression of various related genes. Cleaved caspase3, p53, p21 and puma expression were significantly upregulated in the DKK1 transfected cells. The population of apoptotic cells was increased in stable DKK1 cells and tumor growth suppression was also observed in nude mice with DKK1 transfected cells. In conclusion, this is the first report to show that DKK1 expression is epigenetically silenced in kidney cancer and its reexpression induces apoptosis and cell cycle arrest in RCC., (Copyright © 2010 UICC.)

Background: To the authors' knowledge, the functional significance of the Wnt antagonist dickkopf homolog 4 (DKK4) has not been investigated previously in renal cancer., Methods: The authors initially observed that the expression of DKK4 was significantly higher in renal cancer tissues compared with adjacent normal kidney tissues. To assess the function of DKK4, stable DKK4-transfected cells were established, and functional analyses were performed, including a T-cell factor/lymphoid enhancer factor (TCF/LEF) reporter assay and tests for cell viability, colony formation, apoptosis, cell cycle, invasive capability, wound-healing capability, and in vivo tumor growth., Results: The relative TCF/LEF activity was significantly lower in DKK4-transfected cells compared with empty vector, and nuclear β-catenin expression was decreased in DKK4 transfectants. In addition, expression levels of the β-catenin downstream effector proteins cyclin D1 and c-Myc were decreased in DKK4 transfectants. However, greater invasiveness and migration were observed in stably transfected DKK4 cells. Increased growth of DKK4-transfected tumors also was observed in nude mice. Members of the Wnt noncanonical/c-Jun-NH2 kinase (JNK) signaling pathway also were effected, such as c-Jun, which had significantly increased expression and phosphorylation in DKK4-stable transfectants, and matrix metalloproteinase-2, which had significantly increased expression in DKK4-stable transfectants., Conclusions: This is the first study to indicate that DKK4 expression is increased in renal cancer tissues and that DKK4 activates the noncanonical JNK signaling pathway while inhibiting the Wnt-canonical pathway., (Copyright © 2010 American Cancer Society.)

The Src family of protein kinases (SFK) plays key roles in regulating fundamental cellular processes, including cell growth, differentiation, cell shape, migration, and survival, and specialized cell signals in various malignancies. The pleiotropic functions of SFKs in cancer make them promising targets for intervention. Here, we sought to investigate the role of microRNA-205 (miR-205) in inhibition of Src-mediated oncogenic pathways in renal cancer. We report that expression of miR-205 was significantly suppressed in renal cancer cell lines and tumors when compared with normal tissues and a nonmalignant cell line and is correlated inversely with the expression of SFKs. miR-205 significantly suppressed the luciferase activity of reporter plasmids containing the 3'-UTR (untranslated region) sequences complementary to either Src, Lyn, or Yes, which was abolished by mutations in these 3'-UTR regions. Overexpression of miR-205 in A498 cells reduced Src, Lyn, and Yes expression, both at mRNA and protein levels. Proliferation of renal cancer cells was suppressed by miR-205, mediated by the phospho-Src-regulated ERK1/2 pathway. Cell motility factor FAK (focal adhesion kinase) and STAT3 activation were also inhibited by miR-205. Transient and stable overexpression of miR-205 in A498 cells resulted in induction of G₀/G₁ cell-cycle arrest and apoptosis, as indicated by decreased levels of cyclin D1 and c-Myc, suppressed cell proliferation, colony formation, migration, and invasion in renal cancer cells. miR-205 also inhibited tumor cell growth in vivo. This is the first study showing that miR-205 inhibits proto-oncogenic SFKs, indicating a therapeutic potential of miR-205 in the treatment of renal cancer.

Secreted frizzled-related protein-5 (sFRP-5) has been identified as 1 of the secreted antagonists that bind Wnt protein. However, the functional significance of sFRP-5 in renal cell cancer (RCC) has not been reported. We hypothesized that sFRP-5 may be epigenetically downregulated through DNA methylation and histone modification and function as a tumor suppressor gene in RCC. Using tissue microarray and real-time RT-PCR, we found that sFRP-5 was significantly downregulated in kidney cancer tissues and cell lines, respectively. DNA bisulfite sequencing of the sFRP-5 promoter region in RCC cell lines showed it to be densely methylated, whereas there was few promoter methylation in normal kidney. The sFRP-5 expression was restored and the acetylation of H3 and H4 histones associated with the sFRP-5 promoter region were significantly increased after treatment with demethylation agent (5-Aza-dc) and histone deacetylase inhibitor (TSA). When RCC cells were transfected with the sFRP-5 gene, significant inhibition of anchorage independent colony formation and cell invasion were observed compared to controls. The sFRP-5 transfection also significantly induced apoptosis in RCC cells. In conclusion, this is the first report documenting that the sFRP-5 is downregulated by promoter methylation and histone acetylation and functions as a tumor suppressor gene by inducing apoptosis in RCC cells.

Background: The purpose of this study was to identify new tumour suppressor microRNAs (miRs) in clear cell renal cell carcinoma (ccRCC), carry out functional analysis of their suppressive role and identify their specific target genes., Methods: To explore suppressor miRs in RCC, miR microarray and real-time PCR were performed using HK-2 and A-498 cells. Cell viability, invasion and wound healing assays were carried out for functional analysis after miR transfection. To determine target genes of miR, we used messenger RNA (mRNA) microarray and target scan algorithms to identify target oncogenes. A 3'UTR luciferase assay was also performed. Protein expression of target genes in ccRCC tissues was confirmed by immunohistochemistry and was compared with miR-584 expression in ccRCC tissues., Results: Expression of miR-584 in RCC (A-498 and 769-P) cells was downregulated compared with HK-2 cells. Transfection of miR-584 dramatically decreased cell motility. The ROCK-1 mRNA was inhibited by miR-584 and predicted to be target gene. The miR-584 decreased 3'UTR luciferase activity of ROCK-1 and ROCK-1 protein expression. Low expression of miR-584 in ccRCC tissues was correlated with high expression of ROCK-1 protein. The knockdown of ROCK-1 by siRNA inhibited cell motility., Conclusion: miR-584 is a new tumour suppressor miR in ccRCC and inhibits cell motility through downregulation of ROCK-1.

The secreted Frizzled-related proteins (sFRP) are modulators of the Wnt signaling pathway, which is involved in embryonic development and tumor progression. The functions of sFRP2 have not been studied in renal cancer. Transient transfection of sFRP2 promoted cell growth in renal carcinoma cells, whereby the largest effect was observed in A498 cells. To further study the functions of sFRP2 gene in renal carcinoma cells, we established A498 renal cancer cell lines, which stably expressed sFRP2. Stably expressed sFRP2 significantly promoted cell proliferation in vitro and in vivo tumor growth. The stably expressed sFRP2 cells were also found to have reduced UV-induced apoptosis and increased G(2) phase of the cell cycle. The phosphorylation level at Ser(33/37)/Thr(41) of beta-catenin was lower in the stable sFRP2 cell lines compared with the control cell line. sFRP2 significantly activated T-cell factor/lymphoid enhancer factor transcriptional activity. In the stable sFRP2 cell line, expression of c-Fos, Bcl2, Bcl-w, cyclin B2, and cyclin E2 genes was significantly increased and p53 expression was decreased. This is the first report documenting that sFRP2 activates the canonical Wnt pathway and promotes cell growth by evoking diverse signaling cascades in renal cancer cells. This study may provide better strategies for the management of renal cancer through regulation of sFRP2 pathways.

The secreted frizzled-related protein (sFRP) family plays an important role in the inhibition of the Wnt signaling pathway in various cancers. The functional significance of Wnt antagonist sFRP3 has not been investigated in renal cancer. We performed tissue microarray and found that the level of sFRP3 protein was high in normal kidney, low in primary renal cancer tissues, and high in metastatic renal cancer tissues. Therefore, we hypothesized that sFRP3 may play an important role in metastatic renal cancer. To test this hypothesis, we performed a series of experiments to determine the role of sFRP3 using primary and metastatic renal cancer cell lines. Functional analysis showed increased numbers of viable and invaded cells and tube formation and decreased numbers of apoptotic cells in the sFRP3-transfected renal cancer cell line A498. Promotion of tumor growth was also observed in nude mice injected with sFRP3-transfected A498 cells. In contrast, the number of viable cells and invasive cells was decreased in sFRP3 mRNA knockdown metastatic cells (ACHN and Hs891.T). To investigate the mechanism of sFRP3 function, we performed microarray analysis to see which genes were upregulated or downregulated by sFRP3 expression. Among these genes, MMP-3 and ANGPT1 were significantly upregulated in sFRP3-transfected cells. In conclusion, this is the first report to show that sFRP3 expression promotes cell growth, invasion, and inhibition of apoptosis in renal cancer cells.

Wnt inhibitory factor-1 (WIF-1) has been identified as one of the secreted antagonists that bind Wnt protein. WIF-1 has been described as a tumor suppressor in various types of cancer. However, the molecular function of WIF-1 gene has never been examined in human renal cell carcinoma (RCC). Therefore, we hypothesized that WIF-1 functions as a tumor suppressor gene and overexpression of this gene may induce apoptosis and inhibit tumor growth in RCC cells. Immunohistochemistry and real-time reverse transcription-PCR revealed that WIF-1 was significantly downregulated in RCC samples and RCC cell lines, respectively. Bisulfite sequencing of the WIF-1 promoter region in RCC cell lines showed it to be densely methylated, whereas there was no methylation of WIF-1 promoter in normal kidney. Significant inhibition of cell growth and colony formation in WIF-1-transfected cells compared with controls were observed. WIF-1 transfection significantly induced apoptosis and suppressed in vivo tumor growth. Also, Wnt signaling activity and beta-catenin expression were reduced by WIF-1 transfection. In conclusion, this is the first report documenting that the WIF-1 is downregulated by promoter methylation and functions as a tumor suppressor gene by inducing apoptosis in RCC cells.

Background: Epigenetic silencing of several wingless-type mouse mammary tumor virus integration site (Wnt) pathway-related genes has been reported in renal cancer. Except for the T-cell factor 4 gene TCF4, there are no reports regarding Wnt pathway gene polymorphisms in renal cancer. Therefore, the authors of this report hypothesized that the polymorphisms in Wnt signaling genes may be risk factors for renal cancer., Methods: In total, 210 patients (145 men and 65 women) with pathologically confirmed renal cell carcinoma (RCC) and 200 age-matched and sex-matched control individuals were enrolled in this study. We genotyped 14 single nucleotide polymorphisms (SNPs) in 6 genes. including Dickkopf 2 (DKK2) (reference SNP identification number 17037102 [rs17037102], rs419558, and rs447372), DKK3 (rs3206824, rs11022095, rs1472189, rs7396187, and rs2291599), DKK4 (rs2073664), secreted frizzled-related protein 4 (sFRP4) (rs1802073 and rs1802074), mothers against decapentaplegic homolog (SMAD) family member 7 or SMAD7 (rs12953717), and disheveled associated activator of morphogenesis 2 or DAAM2 (rs6937133 and rs2504106) using polymerase chain reaction-restriction fragment length polymorphism analysis and direct sequencing in the patients with RCC and in the healthy, age-matched control group. The relations also were tested between these polymorphisms and clinicopathologic data, including sex, tumor grade, tumor stage, lymph node involvement, distant metastasis, and overall survival., Results: A significant decrease in the frequency of the guanine/adenine (G/A) + A/A genotypes in the DKK3 codon 335 rs3206824 was observed in the patients with RCC compared with the control group. The frequency of the rs3206824 (G/A) A-rs7396187 (guanine/cytosine [G/C]) C haplotype was significantly lower in patients with RCC compared with other haplotypes. In addition, DKK3 rs1472189 cytosine/thymine (C/T) was associated with distant metastasis, and, DKK2 rs17037102 G-homozygous patients had a decreased risk for death in multivariate Cox regression analysis., Conclusions: To the authors' knowledge, this is the first report documenting that DKK3 polymorphisms are associated with RCC and that the DKK2 rs17037102 polymorphism may be a predictor for survival in patients with RCC after radical nephrectomy., (2009 American Cancer Society.)

Purpose: Wnt/beta-catenin signaling is involved in renal cancer. DKK2, a Wnt antagonist, is silenced in some cancers, although its function has not been investigated. We hypothesized that DKK2 may be epigenetically silenced and inhibits progression of renal cell carcinoma (RCC)., Experimental Design: RCC cell lines and a normal kidney cell line were used for methylation and chromatin immunoprecipitation assays. To assess various functions of DKK2, we established stable DKK2-transfected cells and examined them with regard to cell viability, colony formation, apoptosis, cell cycle, and invasive capability. A total of 52 patients with confirmed conventional RCC were enrolled in this study., Results: RCC cell lines had decreased levels of DKK2, which were significantly increased after treatment with 5-Aza-2'-deoxycytidine alone or 5-Aza-2'-deoxycytidine and trichostatin A. In chromatin immunoprecipitation assay, the levels of acetyl H3, acetyl H4, and dimethylated H3K4 were decreased, whereas the level of dimethylated H3K9 was increased in RCC cell lines compared with HK2 cells. Increased methylation in RCC tissues was associated with higher grades, pathologic stages, and pathologic tumor in RCC. Functional analysis showed that the numbers of viable A498 cells were significantly decreased in DKK2-transfected cells compared with mock cells. The number of apoptotic cells and S/G(2)-M phase cells was significantly increased and decreased after DKK2 transfection, respectively. Corresponding to these results, Bcl2 and cyclin D1 expression were also decreased in DKK2-overexpressing cells., Conclusion: DKK2 is epigenetically silenced by methylation in higher grades and stages of RCC. These results suggest that DKK2 inhibits renal cancer progression through apoptotic and cell cycle pathways.

The secreted Frizzled-related protein 1 (SFRP1) is a Wingless-type (Wnt) antagonist that has been associated with various malignancies, including renal cell carcinomas (RCC). However, the functional significance of SFRP1 has never been investigated in metastatic RCC. Here, we investigated the role of this molecule in kidney cancer progression and metastasis. Using Wnt pathway-focused cDNA expression profiling in normal renal, primary RCC, and metastatic RCC cell lines, we identified that SFRP1 is up-regulated in metastatic RCC. SFRP1 overexpression in metastatic RCC was confirmed by immunostaining in renal tissues. We explored the molecular mechanisms underlying SFRP1 up-regulation by analyzing DNA methylation and histone modification patterns on SFRP1 promoter. We found that this gene is unmethylated/hypomethylated and enriched in activating histone modifications in metastatic RCC. To understand the functional significance of SFRP1 overexpression in metastatic RCC with regard to tumorigenesis, we used a small interfering RNA-mediated approach to knockdown the gene and monitored cellular proliferation, apoptosis, and metastatic behavior. Proliferation was unaltered and apoptosis increased on attenuation of SFRP1 expression. Also, SFRP1 depletion decreased the invasive potential of the metastatic RCC cell line, suggesting that the overexpression of this Wnt antagonist may be related to invasiveness and metastatic behavior in RCC. We investigated the molecular basis of the role of SFRP1 in invasion and metastasis and found that matrix metalloproteinase MMP10 is regulated by SFRP1. In conclusion, our data suggest that SFRP1 plays a role in the metastatic potential of RCC. The present findings may be important in the design of treatment modalities for metastatic RCC.

Purpose: A single nucleotide polymorphism (-938C/A, rs2279115) was found in the bcl2 gene, whose -938A allele is significantly associated with increased Bcl2 expression compared with that of the C allele. Bcl2 up-regulation was reported to be associated with longer survival in patients with renal cancer. However, to our knowledge there is currently no information on the role of the bcl2-938C/A single nucleotide polymorphism in renal cell carcinoma cases. Therefore, we investigated the polymorphism at the bcl2 -938C/A site and its effects on clinical characteristics in patients with renal cell carcinoma., Materials and Methods: We genotyped the bcl2-938C/A single nucleotide polymorphism in 216 patients with renal cancer, and in 209 healthy age and gender matched controls. We also investigated the relationship between the bcl2 -938C/A polymorphism, Bcl2 expression, proliferation and apoptosis status in renal cell carcinoma tissues using immunohistochemistry and TUNEL assay. The association of the bcl2 -938C/A single nucleotide polymorphism with survival in patients with renal cell carcinoma was also analyzed by Kaplan-Meier curves., Results: Survival in Bcl2 positive cases was significantly longer than in negative cases. On univariate and multivariate analyses the bcl2 -938CC genotype was independently associated with poor prognosis. Kaplan-Meier analysis showed that survival in patients with CC genotypes was significantly worse than in those with CA+AA genotypes. CC genotype carriers had significantly lower Bcl2 expression and higher proliferative activity in renal cancer tissues than CA+AA genotype carriers., Conclusions: To our knowledge this is the first report to show that the bcl2 -938C/C genotype has worse prognosis and lower survival in patients with renal cell carcinoma. In addition, the bcl2 -938C/A single nucleotide polymorphism was shown to be an independent adverse prognostic factor for renal cell carcinoma.

BTG3/ANA/APRO4 has been reported to be a tumor suppressor gene in some malignancies. It constitutes important negative regulatory mechanism for Src-mediated signaling, a negative regulator of the cell cycle and inhibits transcription factor E2F1. We report that BTG3 is downregulated in renal cancer and that the mechanism of inactivation is through promoter hypermethylation. Quantitative real-time polymerase chain reaction (PCR) showed that BTG3 was downregulated in cancer tissues and cells. Genistein and 5-aza-2'-deoxycytidine (5Aza-C) induced BTG3 messenger RNA (mRNA) expression in A498, ACHN and HEK-293 renal cell carcinoma (RCC) cell lines. Bisulfite-modified PCR and DNA sequencing results showed complete methylation of BTG3 promoter in tumor samples and cancer cell lines. Genistein and 5Aza-C treatment significantly decreased promoter methylation, reactivating BTG3 expression. Chromatin immunoprecipitation assay revealed that genistein and 5Aza-C increased levels of acetylated histones 3, 4, 2H3K4, 3H3K4 and RNA polymerase II at the BTG3 promoter indicative of active histone modifications. Enzymatic assays showed genistein and 5Aza-C decreased DNA Methyltransferase, methyl-CpG-binding domain 2 activity and increased HAT activity. Cell cycle and 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide cell proliferation assays showed that genistein has antiproliferative effect on cancer cell growth through induction of cell cycle arrest. This is the first report to show that BTG3 is epigenetically silenced in RCC and can be reactivated by genistein-induced promoter demethylation and active histone modification. Genistein had similar effects to that of 5Aza-C, which is a potent demethylating agent with high toxicity and instability. Genistein being a natural, non-toxic, dietary isoflavone is effective in retarding the growth of RCC cells, making it a promising candidate for epigenetic therapy in renal carcinoma.

Secreted frizzled-related protein 2 (sFRP2) is a negative modulator of the Wingless-type (Wnt) signaling pathway, and shown to be inactivated in renal cell carcinoma (RCC). However, the molecular mechanism of silencing of sFRP2 is not fully understood. Our study was designed to elucidate the silencing mechanism of sFRP2 in RCC. Expression of sFRP2 was examined in 20 pairs of primary cancers by immunohistochemistry. Kidney cell lines (HK-2, Caki-1, Caki-2, A-498 and ACHN) were analyzed for sFRP2 expression using real-time RT-PCR and Western blotting. The methylation status at 46 CpG sites of the 2 CpG islands in the sFRP2 promoter was characterized by bisulfite DNA sequencing. Histone modifications were assessed by chromatin immunoprecipitation (ChIP) assay using antibodies against AcH3, AcH4, H3K4 and H3K9. sFRP2 was frequently repressed in primary cancers and in RCC cells. The majority of sFRP2 negative cells had a methylated promoter. Meanwhile, sFRP2 expression was repressed by a hypomethylated promoter in Caki-1 cells, and these cells had a repressive histone modification at the promoter. In Caki-1 cells, sFRP2 was reactivated by trichostatin A (TSA). Repressive histone modifications were also observed in RCC cells with hypermethylated promoters, but sFRP2 was reactivated only by 5-aza-2'-deoxycytidine (DAC) and not by TSA. However, the activation of the silenced sFRP2 gene could be achieved in all cells using a combination of DAC and TSA. This is the first report indicating that aberrant DNA methylation and histone modifications work together to silence the sFRP2 gene in RCC cells.

Purpose: MDM2 is a major negative regulator of p53, and a single nucleotide polymorphism in the MDM2 promoter region SNP309 (rs2279744) has been shown to increase the affinity of the transcriptional activator Sp1, resulting in elevated MDM2 transcription and expression in some cancers. There is currently no information about the role of MDM2 polymorphism in renal cell carcinoma (RCC). We investigated polymorphisms in p53-related genes, including MDM2, and their interactions in renal cancer., Experimental Design: We genotyped three single nucleotide polymorphisms of three genes (p53 Arg(72)Pro, p21 Ser(31)Arg, and MDM2 SNP309) in 200 patients with renal cancer and 200 age- and gender-matched healthy subjects. Genotyping was confirmed by direct DNA sequencing. Samples that showed significant polymorphic variants were analyzed for MDM2 expression by immunohistochemistry. Association of polymorphic variants on survival of RCC patients was analyzed by Kaplan-Meier curves., Results: A significant increase in the GG genotype of the MDM2 SNP309 was observed in RCC patients compared with healthy controls (odds ratio, 1.80; 95% confidence interval, 1.14-2.84). To investigate the effect of the MDM2 SNP309 polymorphism on MDM2 expression, immunohistochemistry was done in genotyped RCC tissues. Positive staining for MDM2 was detected in 2 of 15 (13%) TT genotype, 4 of 15 (26%) TG genotype, and 5 of 10 (50%) GG genotype carriers. The frequency of MDM2 expression in GG genotype carriers was significantly higher than that in TT genotype carriers. Polymorphisms of p53 Arg(72)Pro and p21 Ser(31)Arg did not show significant association with RCC. In univariate and multivariate analysis, MDM2 SNP309 GG genotype was independently associated with poor prognosis. Kaplan-Meier curve analysis showed that survival of patients with GG carriers was significantly worse than that of carriers with TG + TT genotypes., Conclusions: This is the first report to show a significant association between functional polymorphisms in MDM2 and increased risk of developing renal cancer. In addition, the MDM2 polymorphism was shown to be an independent adverse prognostic factor for RCC. Patients with MDM2 309GG genotype showed worse prognosis and low survival.

The estrogen metabolite, 4-hydroxy-estrogen, has been shown to play a role in malignant transformation of male kidneys. To counteract the effects of this catechol-estrogen, the catechol-O-methyltransferase (COMT) enzyme is capable of neutralizing the genotoxic effects of this compound. A polymorphic variant of COMT has been shown to have a reduced enzyme activity, and thus, we hypothesize that single nucleotide polymorphisms of the COMT gene can be a risk factor for renal cell cancer (RCC). To determine this hypothesis, a study of a Japanese male population was used and the genetic distributions of COMT polymorphisms at codons 62 (C-->T), 72 (G-->T), and 158 (G-->A) were analyzed in 157 normal healthy subjects and 123 sporadic RCC (clear cell type) samples by using a sequence-specific PCR technique. These experiments show that the variant genotype (P = 0.025) and allele (P = 0.011) at codon 62 is a risk factor for RCC. The odds ratio and 95% confidence interval for cancer were 3.16 and 1.29 to 7.73, respectively, for the T/T genotype as compared with wild-type. No associations for renal cancer were found at either codons 72 or 158 in this Japanese male population. However, codons 62 and 158 were observed to be in linkage disequilibrium, and haplotype analysis shows the combined forms of T-A, T-G, and C-A to be associated with RCC as compared with C-G (P < 0.001). When evaluating the risk of COMT polymorphisms with grade of cancer, no associations were observed for any of the genotypes. This study is the first to report COMT polymorphism to be associated with RCC. These results are important in understanding the role of COMT polymorphisms in the pathogenesis of RCC.

Purpose: We hypothesized that combined methylation analysis of Wnt antagonist genes could serve as a panel of biomarkers for diagnosis, staging, and prognosis in renal cell carcinoma (RCC)., Experimental Design: Samples (n = 62) of RCC and corresponding normal renal tissue (NRT) were analyzed using methylation-specific PCR for methylation of six Wnt antagonist genes (sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wif-1, and Dkk-3). To increase the sensitivity/specificity of RCC detection, the methylation score (M score) for multigene methylation analysis was developed. Receiver operator characteristic curve analysis was used to determine the optimal sensitivity/specificity of the M score. In addition, the M score was compared with the clinicopathologic outcome. Thirty-three serum DNA samples were also used to investigate the methylation status of Wnt antagonist genes., Results: The methylation levels of all Wnt antagonists were significantly higher in RCC than in NRT. In multivariate regression analysis, the methylation level of sFRP-1 was a significant independent predictor of RCC, whereas for sFRP-2 and sFRP-4 there was a trend toward significance as independent predictors. The M score of Wnt antagonist genes was significantly higher in RCC than in NRT. Overall, the M score had a sensitivity of 79.0% and a specificity of 75.8% (area under the curve, 0.808) as a diagnostic biomarker. In addition, the M score could significantly distinguish grade, pT category, M category, and overall survival of RCC patients. The M score was independent of age and gender in predicting overall survival by the Cox proportional hazards model. In RCC patients, 72.7% of the methylation-specific PCR results had identical methylation in samples of tumor and serum DNA. No serum DNA in normal controls showed aberrant methylation of the Wnt antagonist genes. In addition, the methylation status of Wnt antagonist genes in serum DNA was significantly correlated with tumor grade and stage., Conclusions: This is the first report showing that M score analysis of Wnt antagonist genes can serve as an excellent epigenetic biomarker panel for detection, staging, and prognosis of RCC using serum DNA.

DNA repair gene alterations have been shown to cause a reduction in DNA repair capacity and may influence an individual's susceptibility to carcinogenesis. Single nucleotide polymorphisms (SNPs) of DNA repair genes have been shown to cause a reduction in repair activity. We hypothesized that SNPs of DNA repair genes may be a risk factor for renal cell carcinoma (RCC). To test this hypothesis, DNA samples from 112 cases of renal cell cancer and healthy controls (n=180) were analyzed by PCR-RFLP to determine the genotypic frequency of six different polymorphic loci on five DNA repair genes (XRCC1, XPC, ERCC1, XRCC3, and XRCC7). The chi(2) test was applied to compare the genotype frequency between patients and controls. We found that the frequency of 399Gln variant at XRCC1 Arg399Gln was significantly higher in RCC cases than in controls (OR=2.83, 95%CI=1.24-6.49, P=0.01). The frequency of T-A haplotype of XRCC1 194 Trp and XRCC1 399Gln was significantly higher in RCC than controls. No differences in genotypes were observed at the other sites. This is the first report on SNPs of DNA repair genes in renal cell carcinoma that suggests XRCC1 399Gln polymorphism may be a risk factor for RCC. Our present data suggest that the XRCC1 399Gln allele may be linked to susceptibility for RCC.

Loss of heterozygosity (LOH) is frequently associated with the inactivation of tumor suppressor genes. 18q LOH has been frequently reported in colorectal cancer and lung cancer; however, allelic loss on 18q has not been investigated in renal cell carcinoma (RCC). We evaluated LOH on 18q using nine microsatellite markers in 126 with conventional RCC (cRCC). LOH was observed in more than one 18q microsatellite locus in 24 cRCC (19%). We found the highest frequency of LOH (13.5%) at 18q21.3, where the DCC gene is located. We also assessed the relationship between LOH frequency and patient clinical parameters. Patients with a family history of cancer had a significantly higher frequency of 18q LOH than those without such a history (P=0.0017). No associations were found with other parameters, including gender, tumor grade, tumor stage, smoking status, and body mass index. The results suggest that inactivation of tumor suppressor genes at 18q21.3, including DCC and SMAD4 as candidates, may be involved in the tumorigenesis of some conventional RCCs.

Breast cancer resistance protein (BCRP), the second member of the ATP-binding cassette membrane transporter family, has a single nucleotide polymorphism, C421A (resulting in Q141K), that is of functional importance. Our aim was to explore the relationship between this polymorphism of the BCRP gene and the risk of renal cell carcinoma (RCC) development. For a case-control study, DNA samples from 200 nonpapillary RCC patients and 200 healthy control subjects were analyzed using the TaqMan technique. The genotypic frequencies of the BCRP C421A polymorphism were compared between RCC patients and control subjects. The frequency of the C/C genotype was significantly higher in RCC patients than in control subjects (age- and gender-adjusted OR = 1.96, 95% CI 1.32-2.93). No associations were observed between the BCRP C421A polymorphism and clinicopathologic or epidemiologic factors, including age, gender, tumor grade, stage, cigarette smoking, family history of cancer and body mass index. Carriers with the C/C genotype of the BCRP C421A polymorphism are at risk of developing nonpapillary RCC. These data suggest that BCRP is a candidate RCC susceptibility gene., ((c) 2005 Wiley-Liss, Inc.)

The aim of this study was to examine the relationship between allelic imbalance (AI) on chromosome 5q and clinico-pathologic parameters, including cigarette smoking. We examined the AI on chromosome 5q in 119 clear-cell renal cell carcinomas (CRCC) by a fluorescent polymerase chain reaction technique using nine microsatellite markers. AI of one or more loci was found in 43 cases (36.1%). The most frequent AI was observed at chromosome 5q23.1 (D5S467), where the LOX gene is located. The minimally involved region ranged from 5q22.1 to 5q23.2, with a possible breakpoint between 5q22 and 5q22.1. Regarding the relationships between the frequency of AI and the clinico-pathologic and environmental backgrounds, smokers had a significantly higher frequency of AI of 5q22.2 approximately q22.3 (D5S471) than nonsmokers (P = 0.013). No other significant associations were found between AI of specific loci and other parameters. Our results suggest that AI at 5q plays an important role in the genesis of CRCC. In addition, smoking may cause genetic alterations at 5q22.2 approximately q23.1, where the LOX gene is located.

Little is known about the clinical significance at the frequent association of 3p loss with 5q gain/loss in conventional renal cell carcinoma (RCC). We analyzed the clinical significance of copy number gain and loss at 5q21 approximately q23 combined with allelic loss of 3p25 (including the VHL gene). Fifty RCCs were examined by dual-color fluorescence in situ hybridization with DNA probes for D3Z1 (3cen), cCI3-865 (3p25.1 approximately p25.3), D5S23 (5p15.2), cCI5-243 (5q21.2 approximately q21.3), and cCI5-215 (5q22.3 approximately q23.2). In patients who had 3p loss, there was a significant association of loss at 5q22.3 approximately q23.2 with large tumors (>7 cm) and high-grade tumors (both P < 0.05), whereas gain at 5q22.3 approximately q23.2 was associated with low-grade tumors (P < 0.05). There was also a significant association loss at 5q21.2 approximately q21.3 high-grade tumors in patients with 3p loss (P < 0.05). Patients with 3p loss and gain at 5q22.3 approximately q23.2 had a significantly better disease-specific survival than those who had 3p loss without such gain (P < 0.05). Allelic loss of 3p25 including the VHL gene is thought to be an immediate event in the development of conventional RCC. Copy number gains or losses of 5q21 approximately q23 are thought to be events that lead to tumor progression although the clinical significance of either gains or losses is not well known.

Objective: To identify the role of lymph node dissection in renal cell carcinoma (RCC)., Material and Methods: A total of 100 patients (66 males, 34 females) were enrolled in the study. The mean age and tumor size were 61.4 years and 5.8 cm, respectively. A total of 41 patients (41%) had tumors <4 cm in diameter. The pathological status was pT1, pT2 and pT3 in 60, 11 and 29 patients, respectively., Results: In total, lymph node metastases were found in seven cases (7%). Of 40 patients with pT1a tumors (tumor size <4 cm), one (2.5%) had lymph node metastasis. Patients with lymph node metastases had significantly larger tumors than those without (8.9 vs 5.5 cm; p<0.05). Regarding patient outcome, 33 (33%) had tumor progression (alive with disease, n=14; disease-specific death, n=19) after a median follow-up period of 54.0 months. In univariate analysis, 15/18 prognostic markers [tumor size, tumor grade, pT, pN and M categories, stage, microscopic venous invasion (V category), microscopic lymphatic invasion (Ly category), pathological tumor infiltration pattern (INF category), plasma fibrinogen, C-reactive protein, immunosuppressive acidic protein, alpha-2 globulin and erythrocyte sedimentation rates at 1 and 2 h] were common significant predictors of tumor progression. A Cox hazard model revealed tumor size, tumor grade and pathological stage to be independent prognostic factors., Conclusions: Tumor size is a crucial prognostic factor for tumor progression, and lymph node dissection may be omitted in T1a tumors.

It has been shown that the matrix metalloproteinase (MMP)-1 promoter polymorphism 1G/2G is associated with an increased risk of developing various cancers including renal cell carcinoma (RCC), and is in linkage disequilibrium (LD) with the MMP-3 promoter polymorphism 5A/6A. These two genes are localized in 11q22 adjacent to each other. However, the relationship between the MMP-3 5A/6A polymorphism and susceptibility to cancer remains ambiguous. In this study, we genotyped eight polymorphisms in the region containing the MMP-1 and MMP-3 genes in 177 healthy subjects, and explored the relationships between RCC and these polymorphisms or haplotypes in 156 RCC cases and 230 age- and gender-matched controls. All the subjects studied were of Japanese descent. There were three polymorphisms that showed stronger LD with the MMP-1 1G/2G promoter variant than with the MMP-3 5A/6A promoter variant. One of these three polymorphisms was present in exon 2 of the MMP-3 gene and caused an amino acid change, Glu45Lys (G/A). When the genotype distribution of Glu45Lys was compared between RCC patients and controls, the frequency of the G/G genotype was significantly higher in the patients [age- and gender-adjusted odds ratio (OR) = 1.81, 95% confidence interval (CI) = 1.20-2.74]. A significant increase in the frequency of the 2G/2G genotype of the MMP-1 1G/2G polymorphism was also observed in the patients (age- and gender-adjusted OR = 1.86, CI = 1.23-2.82), whereas there was no significant difference for the MMP-3 5A/6A polymorphism. As expected based on these genotype-level results, the frequency of the 2G-G haplotype of MMP-1 1G/2G and MMP-3 Glu45Lys (G/A) polymorphisms was significantly higher in the patients than in the controls (crude OR = 1.95, CI = 1.31-2.91). These findings suggest that this haplotype of MMP-1 and MMP-3 variants may be associated with the risk of developing RCC.

Matrix metalloproteinase (MMP)-1 is associated with tumor cell invasion and metastasis, and its promoter polymorphism has been shown to influence the transcriptional level. Our study explored the association between this polymorphism and renal cell carcinoma in a Japanese population. DNA was extracted from peripheral blood and normal tissue of 119 patients with conventional renal cell carcinoma (RCC) and from 210 age- and sex-matched healthy volunteers. Genotyping was carried out using direct sequencing. In the MMP-1 gene promoter polymorphism, it was demonstrated that the frequency of the 2G/2G genotype, which is associated with higher enzyme activity, was significantly higher in patients with RCC than in controls (p = 0.0015; OR = 2.082; 95% CI 1.317-3.293). When stratified for gender, only men showed a significant association of the polymorphism with RCC (p = 0.0028; OR = 2.307; 95% CI 1.333-3.990). However, no significant association was observed between the 2G/2G genotype and clinicopathologic parameters including age, gender, tumor grade and pathologic stage. Our present data suggest that the MMP-1 promoter polymorphism may be linked to susceptibility for conventional RCC., (Copyright 2003 Wiley-Liss, Inc.)