Progression of malignancy in clear cell renal cell carcinomas

High SIPA-1 expression in proximal tubules of human kidneys under pathological conditions

Systemic lupus erythematosus (SLE) and clear cell renal cell carcinoma (CC-RCC) are serious disorders and usually fatal, and always accompanied with pathological changes in the kidney. Signal-induced proliferation-associated protein 1 (SIPA-1) is a Rap1GTPase activating protein (Rap1GAP) expressed in the normal distal and collecting tubules of the murine kidney. Lupus-like autoimmune disease and leukemia have been observed in SIPA-1 deficient mice, suggesting a pathological relevance of SIPA-1 to SLE and carcinoma in human being. The expression pattern of SIPA-1 is as yet undefined and the pathogenesis of these diseases in humans remains elusive. In this study, we used both immunohistochemistry and quantum dot (QD)-based immunofluorescence staining to investigate the expression of SIPA-1 in renal specimens from SLE and CC-RCC patients. MTT assay and Western blotting were employed to evaluate the effects of SIPA-1 overexpression on the proliferation and apoptosis of renal cell lines. Semi-quantitative reverse transcriptase-PCR (RT-PCR) was applied to examine the changes of hypoxia-inducible factor-1α (HIF-1α) mRNA level. Results showed that SIPA-1 was highly expressed in the proximal and collecting tubules of nephrons in SLE patients compared to normal ones, and similar results were obtained in the specimens of CC-RCC patients. Although SIPA-1 overexpression did not affect cellular proliferation and apoptosis of both human 786-O renal cell carcinoma cells and rat NRK-52E renal epithelial cell lines, RT-PCR results showed that HIF-1α mRNA level was down-regulated by SIPA-1 overexpression in 786-O cells. These findings suggest that SIPA-1 may play critical roles in the pathological changes in kidney, and might provide a new biomarker to aid in the diagnosis of SLE and CC-RCC.

Theoretical model of treatment strategies for clear cell carcinoma of the ovary: focus on perspectives

OBJECTIVES

Among epithelial ovarian cancer (EOC), clear cell carcinomas (CCC) differ from the other histologic types with respect to their clinical characteristics, carcinogenesis and prognosis. The aim of this review is to summarize the current knowledge and future perspective on the new therapeutic targets and treatment strategies for CCC.

MATERIALS AND METHODS

The present article reviews the English language literature for preclinical and clinical trials and promising molecular targets on CCC of the ovary, based on the gene expression profiling studies.

RESULTS

Here, we show that (1) the expression of the genes involved in transcription, signaling, cell cycle, adhesion, matrix, proteinase, and detoxification was greatly increased in the CCC carcinogenesis; (2) upregulation of hepatocyte nuclear factor-1beta (HNF-1beta) and Polo-like kinase (PLK)-Early mitotic inhibitor-1 (Emi1) as well as their downstream targets are specifically found in most CCC. The promising molecular targeting approach will emerge in the context of HNF-1beta and PLK-Emi1 biology; and 3) several significant common pathways observed in CCC of the ovary overlap the datasets identified in CCC of the kidney. To improve the outcome in CCC therapy, we must learn various adaptive treatment strategies for renal CCC, although it is not supported by any preliminary clinical data.

CONCLUSION

The inhibitors that target HNF-1beta and PLK-Emi1 and their downstream signaling molecules would be evaluated. In addition, the therapy currently used in renal CCC should be considered as an alternative for the present treatments or an attractive therapeutic option for ovarian CCC. The challenges accompanying the recent advance are described in this review article.

Functional annotation of IFN-alpha-stimulated gene expression profiles from sensitive and resistant renal cell carcinoma cell lines

The antiproliferative, antiviral, and immunomodulatory properties of interferons (IFNs) have led to its therapeutic implementation. IFNs effects are mediated by a complex network of signal transducers, culminating in IFN-stimulated gene (ISG) induction. This complexity leads to diverse clinical responses to IFN, from no response to complete regression of disease. Elucidation of ISG induction patterns is, therefore, essential to understand and maximize its therapeutic potential. To correlate ISG expression profiles with IFN responsiveness, two renal cell carcinoma (RCC) cell lines differing in antiviral and apoptotic response to IFN were treated with IFN-alpha for different times, and expression profiles were analyzed using a customized microarray containing 850 unique putative ISGs. Genes with similar kinetics of induction in both cell lines were clustered and analyzed for gene function. Seven sets of coordinately regulated genes were identified by k-means cluster analysis, and significant functional similarities were identified for five of the seven sets. Strikingly, expression of genes associated with transcription temporally preceded expression of those involved in signal transduction. Enhanced antiviral sensitivity to IFN was coincident with sustained expression of ISGs involved in transcriptional regulation. However, no difference in Stat1 activation was observed between the cell lines. Analysis of ISG expression patterns suggests that subtle differences in transcription profiles contribute to differences in IFN responsiveness.