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Supplementary Data from Enhanced Susceptibility to Chemical Induction of Ovarian Tumors in Mice with a Germ Line p53 Mutation

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Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP).Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members.Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels.Conclusion:RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25.

Translation on this Article from Fine Mapping of Chromosome 6q23-25 Region in Familial Lung Cancer Families Reveals RGS17 as a Likely Candidate Gene

Supplementary Figure 1 from Identification of a Novel Tumor Suppressor Gene p34 on Human Chromosome 6q25.1

In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25. [Cancer Res 2007;67(1):93–9]

To identify the genetic determinants of colon tumorigenesis, 268 male mice from 33 inbred strains derived from different genealogies were treated with azoxymethane (AOM; 10 mg/kg) once a week for six weeks to induce colon tumors. Tumors were localized exclusively within the distal colon in each of the strains examined. Inbred mouse strains exhibit a large variability in genetic susceptibility to AOM-induced colon tumorigenesis. The mean colon tumor multiplicity ranged from 0 to 38.6 (mean = 6.5 ± 8.6) and tumor volume ranged from 0 to 706.5 mm3 (mean = 87.4 ± 181.9) at 24 weeks after the first dose of AOM. AOM-induced colon tumor phenotypes are highly heritable in inbred mice, and 68.8% and 71.3% of total phenotypic variation in colon tumor multiplicity and tumor volume, respectively, are attributable to strain-dependent genetic background. Using 97,854 single-nucleotide polymorphisms, we carried out a genome-wide association study (GWAS) of AOM-induced colon tumorigenesis and identified a novel susceptibility locus on chromosome 15 (rs32359607, P = 6.31 × 10–6). Subsequent fine mapping confirmed five (Scc3, Scc2, Scc12, Scc8, and Ccs1) of 16 linkage regions previously found to be associated with colon tumor susceptibility. These five loci were refined to less than 1 Mb genomic regions of interest. Major candidates in these loci are Sema5a, Fmn2, Grem2, Fap, Gsg1l, Xpo6, Rabep2, Eif3c, Unc5d, and Gpr65. In particular, the refined Scc3 locus shows high concordance with the human GWAS locus that underlies hereditary mixed polyposis syndrome. These findings increase our understanding of the complex genetics of colon tumorigenesis, and provide important insights into the pathways of colorectal cancer development and might ultimately lead to more effective individually targeted cancer prevention strategies. Mol Cancer Res; 10(1); 66–74. ©2011 AACR.

Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undeter- mined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology ofLung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis ofmatched tumor and normal human tissues, we f that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. Conclusion: RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25. Lung cancer can occur sporadically in people with no known family history of lung cancer or it can be familial, occurring in multiple members of the same family. Initial evidence of a genetic basis for susceptibility to lung cancer came from

Mice with a germ line p53 mutation (p53Ala135Val/wt) display increased susceptibility to lung, skin, and colon carcinogenesis. Here, we show that p53Ala135Val/wt mice developed ovarian tumors significantly more rapidly than their wild-type littermates after 7,12-dimethylbenz(a)anthracene (DMBA) treatment. Approximately 50% of the ovarian tumors in p53wt/wt mice and 23% in p53Ala135Val/wt mice are adenocarcinomas and the remaining tumors were adenocarcinoma mixed with sarcoma or ovarian sarcomas. All of the p53Ala135Val/wt mice had died of ovarian tumors 25 weeks after the initial DMBA treatment, whereas >50% of p53wt/wt mice were still alive. These mice not only have a shortened tumor latency but also closely resemble a subset of human ovarian tumors containing the p53 mutation. Microarray and GenMAPP analyses revealed that the mutant p53 (Ala135Val) affected several cellular processes, including the cell cycle, apoptosis, and Wnt pathways. These findings indicate that a germ line p53 mutation significantly enhanced DMBA-induced ovarian tumor development and progression. (Mol Cancer Res 2008;6(1):99–109)

In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25. [Cancer Res 2007;67(1):93–9]