Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-12332

Schulze-Bergkamen, H; Ehrenberg, R; Hickmann, L; Vick, B; Urbanik, T; Schimanski, C C; Berger, M R; Schad, A; Weber, A; Heeger, S; Galle, P R; Moehler, M (2008). Bcl-x(L) and Myeloid cell leukaemia-1 contribute to apoptosis resistance of colorectal cancer cells. World Journal of Gastroenterology, 14(24):3829-3840.

[img] PDF - Registered users only
922kB

View at publisher

Abstract

AIM: To explore the role of Bcl-x(L) and Myeloid cell leukaemia (Mcl)-1 for the apoptosis resistance of colorectal carcinoma (CRC) cells towards current treatment modalities. METHODS: Bcl-x(L) and Mcl-1 mRNA and protein expression were analyzed in CRC cell lines as well as human CRC tissue by Western blot, quantitative PCR and immunohistochemistry. Bcl-x(L) and Mcl-1 protein expression was knocked down or increased in CRC cell lines by applying specific siRNAs or expression plasmids, respectively. After modulation of protein expression, CRC cells were treated with chemotherapeutic agents, an antagonistic epidermal growth factor receptor (EGFR1) antibody, an EGFR1 tyrosine kinase inhibitor, or with the death receptor ligand TRAIL. Apoptosis induction and cell viability were analyzed. RESULTS: Here we show that in human CRC tissue and various CRC cell lines both Bcl-x(L) and Mcl-1 are expressed. Bcl-x(L) expression was higher in CRC tissue than in surrounding non-malignant tissue, both on protein and mRNA level. Mcl-1 mRNA expression was significantly lower in malignant tissues. However, protein expression was slightly higher. Viability rates of CRC cells were significantly decreased after knock down of Bcl-x(L) expression, and, to a lower extent, after knock down of Mcl-1 expression. Furthermore, cells with reduced Bcl-x(L) or Mcl-1 expression was more sensitive towards oxaliplatin- and irinotecan-induced apoptosis, and in the case of Bcl-x(L) also towards 5-FU-induced apoptosis. On the other hand, upregulation of Bcl-x(L) by transfection of an expression plasmid decreased chemotherapeutic drug-induced apoptosis. EGF treatment clearly induced Bcl-x(L) and Mcl-1 expression in CRC cells. Apoptosis induction upon EGFR1 blockage by cetuximab or PD168393 was increased by inhibiting Mcl-1 and Bcl-x(L) expression. More strikingly, CD95- and TRAIL-induced apoptosis was increased by Bcl-x(L) knock down. CONCLUSION: Our data suggest that Bcl-x(L) and, to a lower extent, Mcl-1, are important anti-apoptotic factors in CRC. Specific downregulation of Bcl-x(L) is a promising approach to sensitize CRC cells towards chemotherapy and targeted therapy.

Citations

22 citations in Web of Science®
25 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

1 download since deposited on 04 Feb 2009
0 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Institute of Surgical Pathology
DDC:610 Medicine & health
Language:English
Date:2008
Deposited On:04 Feb 2009 10:29
Last Modified:02 Dec 2013 18:45
Publisher:WJG Press
ISSN:1007-9327
Publisher DOI:10.3748/wjg.14.3829
PubMed ID:18609706

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page