Browsing by Author "Becker, Volker (7102882305)"

Cadherins represent a family of calcium-dependent cell adhesion molecules with an important regulatory function for maintenance of tissue architecture. Alterations of cadherin expression have been demonstrated in the development and progression of different epithelial tumors. In renal cell carcinoma (RCC), the majority of tumors express N-cadherin and cadherin-6. Screening a series of 16 RCC cell lines for the expression of different novel type II cadherins by RT-PCR revealed a complex pattern of cadherin expression: cadherins 6 and 14 were expressed in most of the RCC cell lines, whereas cadherins 11, 12 and 13 could not be detected at all. Interestingly, cadherin-8, previously shown in mice to be restricted to the CNS and thymus during development, was detected by RT-PCR, immunofluorescence and in situ hybridization in 4 of 16 RCC cell lines as well as in paraffin sections of the corresponding human RCC biopsies. In normal renal tissue, however, cadherin-8 could be detected only during the early stages of kidney development. These results suggest that alterations of type II cadherin expression may play a role in RCC development. In particular, cadherin-8 may be involved in both kidney morphogenesis as well as tumorigenesis in some types of RCC. © 2002 Wiley-Liss, Inc.

Cadherins represent a family of calcium-dependent cell adhesion molecules with an important regulatory function for maintenance of tissue architecture. Alterations of cadherin expression have been demonstrated in the development and progression of different epithelial tumors. In renal cell carcinoma (RCC), the majority of tumors express N-cadherin and cadherin-6. Screening a series of 16 RCC cell lines for the expression of different novel type II cadherins by RT-PCR revealed a complex pattern of cadherin expression: cadherins 6 and 14 were expressed in most of the RCC cell lines, whereas cadherins 11, 12 and 13 could not be detected at all. Interestingly, cadherin-8, previously shown in mice to be restricted to the CNS and thymus during development, was detected by RT-PCR, immunofluorescence and in situ hybridization in 4 of 16 RCC cell lines as well as in paraffin sections of the corresponding human RCC biopsies. In normal renal tissue, however, cadherin-8 could be detected only during the early stages of kidney development. These results suggest that alterations of type II cadherin expression may play a role in RCC development. In particular, cadherin-8 may be involved in both kidney morphogenesis as well as tumorigenesis in some types of RCC. © 2002 Wiley-Liss, Inc.

The α-defensins human neutrophil peptides (HNPs)-1, -2, and -3 have been described as cytotoxic peptides with restricted expression in neutrophils and in some lymphocytes. In this study we report that HNPs-1, -2, and -3 are also expressed in renal cell carcinomas (RCCs). Several RCC lines were found to express mRNA as well as the specific peptides of HNP-1, -2, and -3 demonstrated by reverse transcriptase-polymerase chain reaction, mass spectrometric, and flow cytometric analyses. At physiological concentrations HNPs-1, -2, and -3 stimulated cell proliferation of selected RCC lines in vitro but at high concentrations were cytotoxic for all RCC lines tested. As in RCC lines, α-defensins were also detected in vivo in malignant epithelial cells of 31 RCC tissues in addition to their expected presence in neutrophils. In most RCC cases randomly, patchy immunostaining of α-defensins on epithelial cells surrounding neutrophils was seen, but in six tumors of higher grade malignancy all tumor cells were diffusely stained. Cellular necrosis observed in RCC tissues in association with extensive patches of HNP-1, -2, and -3, seemed to be related to high concentrations of α-defensins. The in vitro and in vivo findings suggest that α-defensins are frequent peptide constituents of malignant epithelial cells in RCC with a possible direct influence on tumor proliferation.