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Progression Stages (progression + stage)
Selected AbstractsSignificance of Fas expression alteration during tumor progression of renal cell carcinomaINTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2006TAKEHIRO SEJIMA Background:, In order to characterize the alteration of apoptotic regulatory molecule expression during tumor progression of renal cell carcinoma (RCC), we compared the expression between tumor and normal tissues, and evaluated the relationship of the expression in tumors with pathological and clinical characteristics. Methods:, Competitive reverse transcription,polymerase chain reaction (RT,PCR) and immunohistochemistry (IHC) allowed the determination of Fas and bcl-2 mRNA and protein expression in surgically resected tumor and normal tissue of 50 RCC. Results:, The mRNA expression of Fas and bcl-2 in RCC was significantly reduced compared to that in normal tissues. An IHC analysis was supportive of the RT,PCR results. In terms of relationships with pathological and clinical characteristics, the mRNA and protein expression of Fas in high-stage or high-grade tumors was significantly higher than that in low-stage or low-grade tumors. Moreover, a statistically poor prognosis was observed in tumor cases expressing a high amount of mRNA. In bcl-2 analysis, the mRNA and protein expression was significantly reduced in clear cell tumors compared to chromophobe cell tumors. Conclusion:, It is suggested that the reduced expression of Fas and bcl-2 in RCC compared with the expression in normal kidney is a prominent alteration of apoptotic regulatory molecules. The alteration of the up-regulated Fas expression might be characterized during the tumor progression stage. It is also suggested that the effect of alteration of bcl-2 expression might be minimal during the tumor progression stage because of the reduced expression in tumors of the clear cell type, which is the most dominant cell type in RCC. [source] Proteomic analysis of membrane rafts of melanoma cells identifies protein patterns characteristic of the tumor progression stagePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 22 2008Frédérique Baruthio Abstract The molecular mechanisms controlling the progression of melanoma from a localized tumor to an invasive and metastatic disease are poorly understood. In the attempt to start defining a functional protein profile of melanoma progression, we have analyzed by LC-MS/MS the proteins associated with detergent resistant membranes (DRMs), which are enriched in cholesterol/sphingolipids-containing membrane rafts, of melanoma cell lines derived from tumors at different stages of progression. Since membrane rafts are involved in several biological processes, including signal transduction and protein trafficking, we hypothesized that the association of proteins with rafts can be regulated during melanoma development and affect protein function and disease progression. We have identified a total of 177 proteins in the DRMs of the cell lines examined. Among these, we have found groups of proteins preferentially associated with DRMs of either less malignant radial growth phase/vertical growth phase (VGP) cells, or aggressive VGP and metastatic cells suggesting that melanoma cells with different degrees of malignancy have different DRM profiles. Moreover, some proteins were found in DRMs of only some cell lines despite being expressed at similar levels in all the cell lines examined, suggesting the existence of mechanisms controlling their association with DRMs. We expect that understanding the mechanisms regulating DRM targeting and the activity of the proteins differentially associated with DRMs in relation to cell malignancy will help identify new molecular determinants of melanoma progression. [source] Protein expression of melanocyte growth factors (bFGF, SCF) and their receptors (FGFR-1, c-kit) in nevi and melanomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2007K. A. Giehl Background:, Basic fibroblast growth factor (bFGF) and stem cell factor (SCF) are essential growth factors for melanocytes which carry the receptors FGFR-1 for bFGF and c-kit for SCF. Because both factors may be involved in melanoma development, the expression of bFGF/FGFR-1 and SCF/c-kit was investigated in melanocytic tumors of different progression stages. Methods:, Fifty primary melanomas and 44 melanocytic nevi were analyzed for the expression of SCF, c-kit, bFGF, and FGFR-1 by immunohistochemistry. Results:, In melanoma, SCF and c-kit were expressed in 76 and 84%, respectively, and coexpressed in 66%. bFGF and FGFR-1 were expressed in 45 and 86%, respectively, and coexpressed in 46%. In melanocytic nevi, SCF was expressed in 23% and c-kit in 70% while coexpression was more common in dysplastic (39%) than non-dysplastic subtypes (8%). bFGF and FGFR-1 were expressed in 55 and 67%, respectively, while coexpression was found in 47% but varied considerably between different histological subtypes. Conclusions:, SCF and c-kit were frequently expressed by melanomas and dysplastic nevi suggesting an autocrine growth mechanism as described for bFGF. In both nevi and melanoma, c-kit was almost exclusively found in the epidermis while bFGF was more common in the dermis. Thus the growth factor/receptor expression seems to depend on the cutaneous localization of the melanocytic tumors. [source] Extraction and chromatographic separation of anticarcinogenic fractions from cacao bean huskBIOFACTORS, Issue 3 2005Ki Won Lee Abstract The utilization of cacao bean husk (CBH), a by-product of chocolate manufacture, would be both environmentally and economically beneficial. For this purpose, a process for effectively separating and fractionating CBH fractions having cancer preventive potential was developed in this study. For screening the fractions with potent cancer preventive activity, we examined the effect of extracts and fractions of CBH on the inhibition of gap-junction intercellular communication (GJIC) and the DNA synthesis of cancer cells, both of which are characteristics of the promotion and progression stages in carcinogenesis. The extracts of CBH (especially, the 60% ethanol fraction after extraction with 50% acetone) containing 43 wt.% polyphenol exerted an excellent protective effect on H2O2 -induced inhibition of GJIC in WB-F344 rat liver epithelial cells as determined by the scrape-loading/dye transfer assay. The enhancement of GJIC by the extracts of CBH was approximately 10-fold higher than that of a well-known dietary chemopreventive component, vitamin C. The extracts of CBH (especially, the 60% ethanol fraction) also suppressed DNA synthesis in all liver, stomach, and colon cancer cells as demonstrated by the 3H-thymidine incorporation assay, by approximately four-fold higher than that of vitamin C. These results imply that the polyphenol extracts and fractions of CBH are effective functional materials to be used in either preventing or inhibiting cancer. [source] Molecular footprints of human lung cancer progressionCANCER SCIENCE, Issue 3 2004Jun Yokota Lung cancer is the leading cause of cancer-related death in the world. To understand the molecular processes and pathways of, and contributing factors to lung cancer progression, genetic alterations in various progression stages of lung cancer cells have been studied, since these alterations can be regarded as molecular footprints representing the individual processes of multistage lung carcinogenesis. The results indicate that defects in both the p53 and RB/p16 pathways are essential for the malignant transformation of lung epithelial cells. Several other genes, such as K- ras, PTEN and MYO18B, are genetically altered less frequently than p53 and RB/p16 in lung cancer cells, suggesting that alterations in these genes are associated with further malignant progression or unique phenotypes in a subset of lung cancer cells. However, it is still unclear what genes control the metastatic potential of lung cancer cells. Further analyses of molecular footprints in lung cancer cells, in particular in the cells of metastatic sites, will give us valuable information to fully understand the process of lung cancer progression, and to find novel ways of controlling it. Molecular footprints at the sites of p53 mutations and p16 deletions further indicate that DNA repair activities for G:C to T:A transversion and non-homologous end-joining of DNA double-strand breaks play important roles in the accumulation of genetic alterations in lung cancer cells. Thus, identification of environmental as well as genetic factors inducing or suppressing the occurrence of such alterations would be a clue to find novel ways of lung cancer prevention. [source] | ||||||||||