Journal article
Effect of Disrupting Seven-in-Absentia Homolog 2 Function on Lung Cancer Cell Growth
JNCI : Journal of the National Cancer Institute, Vol.100(22), pp.1606-1629
11/19/2008
DOI: 10.1093/jnci/djn365
PMCID: PMC2720765
PMID: 19001609
Abstract
Hyperactivated epidermal growth factor receptor (EGFR) and/or RAS signaling drives cellular transformation and tumorigenesis in human lung cancers, but agents that block activated EGFR and RAS signaling have not yet been demonstrated to substantially extend patients' lives. The human homolog of Drosophila seven-in-absentia-SIAH-1 and SIAH-2-are ubiquitin E3 ligases and conserved downstream components of the RAS pathway that are required for mammalian RAS signal transduction. We examined whether inhibiting SIAH-2 function blocks lung cancer growth.
The antiproliferative and antitumorigenic effects of lentiviral expression of anti-SIAH-2 molecules (ie, a dominant-negative protease-deficient mutant of SIAH-2 [SIAH-2(PD)] and short hairpin RNA [shRNA]-mediated gene knockdown against SIAH-2) were assayed in normal human lung epithelial BEAS-2B cells and in human lung cancer BZR, A549, H727, and UMC11 cells by measuring cell proliferation rates, by assessing MAPK and other activated downstream components of the RAS pathway by immunoblotting, assessing apoptosis by terminal deoxynucleotidyltransferase-mediated UTP end-labeling (TUNEL) assay, quantifying anchorage-independent cell growth in soft agar, and assessing A549 cell-derived tumor growth in athymic nude mice (groups of 10 mice, with two injections of 1 x 10(6) cells each at the dorsal left and right scapular areas). All statistical tests were two-sided.
SIAH-2 deficiency in human lung cancer cell lines reduced MAPK signaling and statistically significantly inhibited cell proliferation compared with those in SIAH-proficient cells (P < .001) and increased apoptosis (TUNEL-positive A549 cells 3 days after lentivirus infection: SIAH-2(PD) vs control, 30.1% vs 0.0%, difference = 30.1%, 95% confidence interval [CI] = 23.1% to 37.0%, P < .001; SIAH-2-shRNA#6 vs control shRNA, 27.9% vs 0.0%, difference = 27.9%, 95% CI = 23.1% to 32.6%, P < .001). SIAH-2 deficiency also reduced anchorage-independent growth of A549 cells in soft agar (mean number of colonies: SIAH-2(PD) vs control, 124.7 vs 57.3, difference = 67.3, 95% CI = 49.4 to 85.3, P < .001; shRNA-SIAH-2#6 vs shRNA control: 27.0 vs 119.7, difference = 92.7, 95% CI = 69.8 to 115.5, P < .001), and blocked the growth of A549 cell-derived tumors in nude mice (mean tumor volume on day 36 after A549 cell injection: SIAH-2(PD) infected vs uninfected, 191.0 vs 558.5 mm(3), difference = 367.5 mm(3), 95% CI = 237.6 to 497.4 mm(3), P < .001; SIAH-2(PD) infected vs control infected, 191.0 vs 418.3 mm(3), difference = 227.5 mm(3), 95% CI = 87.4 to 367.1 mm(3), P = .003; mean resected tumor weight: SIAH-2(PD) infected vs uninfected, 0.12 vs 0.48 g, difference = 0.36 g, 95% CI = 0.23 to 0.50 g, P < .001; SIAH-2(PD) infected vs control infected, 0.12 vs 0.29 g, difference = 0.17 g, 95% CI = 0.04 to 0.31 g, P = .016).
SIAH-2 may be a viable target for novel anti-RAS and anticancer agents aimed at inhibiting EGFR and/or RAS-mediated tumorigenesis.
Details
- Title: Subtitle
- Effect of Disrupting Seven-in-Absentia Homolog 2 Function on Lung Cancer Cell Growth
- Creators
- Atique U. Ahmed - Mayo ClinicRebecca L. Schmidt - Mayo ClinicCheol Hong Park - Mayo ClinicNanette R. Reed - Mayo ClinicShayla E. Hesse - Mayo ClinicCharles F. Thomas - Mayo ClinicJulian R. Molina - Mayo ClinicClaude Deschamps - Mayo ClinicPing Yang - Mayo ClinicMarie C. Aubry - Mayo ClinicAmy H. Tang - Mayo Clinic in Arizona
- Resource Type
- Journal article
- Publication Details
- JNCI : Journal of the National Cancer Institute, Vol.100(22), pp.1606-1629
- Publisher
- Oxford Univ Press
- DOI
- 10.1093/jnci/djn365
- PMID
- 19001609
- PMCID
- PMC2720765
- ISSN
- 0027-8874
- eISSN
- 1460-2105
- Number of pages
- 24
- Grant note
- Mayo Clinic Clinician-Investigator Training Program Hartz Foundation Young Investigator Fellowship Mayo Foundation R01GM069922 / NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of General Medical Sciences (NIGMS) Mayo Clinic Pobanz Family Predoctoral Research R01CA080127; R03CA077118 / NATIONAL CANCER INSTITUTE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI) CA77118; CA80127 / National Cancer Institute; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI) GM 069922 / National Institutes of Health; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA
- Language
- English
- Date published
- 11/19/2008
- Academic Unit
- Surgery
- Record Identifier
- 9984701648902771
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