Mutations in two short noncoding mononucleotide repeats in most microsatellite-unstable colorectal cancers.

DNA mismatch repair (MMR)-deficient cells typically accumulate mutations in short repetitive DNA tracts. This microsatellite instability (MSI) facilitates malignant transformation when affecting genes with growth-related and caretaker functions. To date, several putative MSI target genes have been proposed mainly based on high mutation frequency within their coding regions. However, some intronic repeat mutations have also been suggested to associate with MSI tumorigenesis, indicating the need for additional analyses on noncoding repeats. Here we have analyzed an intronic T9 repeat of semenogelin I (SEMG1) and report mutation frequencies of 51% (75 of 146) and 62% (8 of 13) in MMR-deficient primary colorectal cancers and cell lines, respectively. The putative effect of the SEMG1 mutations was assessed by RNA and protein level analyses, but no differences were detected between colorectal cancer cell lines with different SEMG1 status. Subsequently, the general background mutation frequency of MSI colorectal cancers was assessed by screening for intergenic T9 repeat alterations. One of 10 examined repeats was mutated in 70% (102 of 145) of the colorectal cancers evaluated. The frequencies observed here are notably higher than previously published in noncoding repeats shorter than 10 bp in MMR-deficient primary tumors. Our results indicate that high mutation frequencies, similar or higher than those observed in proposed and approved target genes, can be detected in repeat tracts of MSI tumors without any apparent selection pressure. These data call for urgent and thorough large-scale evaluation of mutation frequencies in neutral short repetitive sequences in MMR-deficient tumors.

[1]  L. Aaltonen,et al.  Screening for microsatellite instability target genes in colorectal cancers , 2002, Journal of medical genetics.

[2]  M. Merino,et al.  Semenogelins are ectopically expressed in small cell lung carcinoma. , 2001, Clinical cancer research : an official journal of the American Association for Cancer Research.

[3]  H. Lilja,et al.  Isolation and characterization of the major gel proteins in human semen, semenogelin I and semenogelin II. , 1996, European journal of biochemistry.

[4]  N. Copeland,et al.  The human mutator gene homolog MSH2 and its association with hereditary nonpolyposis colon cancer. , 1993, Cell.

[5]  Alessandra Viel,et al.  Human MRE11 is inactivated in mismatch repair‐deficient cancers , 2002, EMBO reports.

[6]  K. Kinzler,et al.  Inactivation of the type II TGF-beta receptor in colon cancer cells with microsatellite instability. , 1995, Science.

[7]  M. Koike,et al.  Germline mutation of MSH6 as the cause of hereditary nonpolyposis colorectal cancer , 1997, Nature Genetics.

[8]  Andrew J. Wilson,et al.  c-Myc overexpression sensitises colon cancer cells to camptothecin-induced apoptosis , 2003, British Journal of Cancer.

[9]  L. Aaltonen,et al.  Population-based molecular detection of hereditary nonpolyposis colorectal cancer. , 2000, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[10]  M. Perucho,et al.  Low mutation incidence in polymorphic noncoding short mononucleotide repeats in gastrointestinal cancer of the microsatellite mutator phenotype pathway. , 2002, Cancer research.

[11]  Luzhe Sun,et al.  Demonstration That Mutation of the Type II Transforming Growth Factor β Receptor Inactivates Its Tumor Suppressor Activity in Replication Error-positive Colon Carcinoma Cells (*) , 1995, The Journal of Biological Chemistry.

[12]  H. Lilja,et al.  Liquefaction of coagulated human semen. , 1984, Scandinavian journal of clinical and laboratory investigation.

[13]  R. Fleischmann,et al.  Mutation of a mutL homolog in hereditary colon cancer. , 1994, Science.

[14]  Hoguen Kim,et al.  Chromosomal imbalances in the colorectal carcinomas with microsatellite instability. , 2003, The American journal of pathology.

[15]  Y. Yuasa,et al.  Germ-line mutation of the hMSH6/GTBP gene in an atypical hereditary nonpolyposis colorectal cancer kindred. , 1997, Cancer research.

[16]  Darryl Shibata,et al.  Ubiquitous somatic mutations in simple repeated sequences reveal a new mechanism for colonic carcinogenesis , 1993, Nature.

[17]  S Srivastava,et al.  A National Cancer Institute Workshop on Microsatellite Instability for cancer detection and familial predisposition: development of international criteria for the determination of microsatellite instability in colorectal cancer. , 1998, Cancer research.

[18]  S. Thibodeau,et al.  Neurofibromatosis type 1 gene as a mutational target in a mismatch repair-deficient cell type , 2003, Human Genetics.

[19]  L. Aaltonen,et al.  Incidence of hereditary nonpolyposis colorectal cancer and the feasibility of molecular screening for the disease. , 1998, The New England journal of medicine.

[20]  A. Duval,et al.  Comparative analysis of mutation frequency of coding and non coding short mononucleotide repeats in mismatch repair deficient colorectal cancers , 2002, Oncogene.

[21]  J. Ku,et al.  Mutations of the Birt-Hogg-Dubé (BHD) gene in sporadic colorectal carcinomas and colorectal carcinoma cell lines with microsatellite instability , 2003, Journal of medical genetics.

[22]  R. Fleischmann,et al.  Mutations of two P/WS homologues in hereditary nonpolyposis colon cancer , 1994, Nature.

[23]  Hoguen Kim,et al.  Identification of MARCKS, FLJ11383 and TAF1B as putative novel target genes in colorectal carcinomas with microsatellite instability , 2002, Oncogene.

[24]  K. Kinzler,et al.  Short mononucleotide repeat sequence variability in mismatch repair-deficient cancers. , 2001, Cancer research.

[25]  Robin J. Leach,et al.  Mutations of a mutS homolog in hereditary nonpolyposis colorectal cancer , 1993, Cell.

[26]  K. Kinzler,et al.  Cancer genes and the pathways they control , 2004, Nature Medicine.

[27]  M. Perucho,et al.  Frameshift mutations in Fas, Apaf-1, and Bcl-10 in gastro-intestinal cancer of the microsatellite mutator phenotype , 2000, Cell Death and Differentiation.

[28]  F. Giles,et al.  Pattern of Gene Expression and Immune Responses to Semenogelin 1 in Chronic Hematologic Malignancies , 2003, Journal of immunotherapy.

[29]  L. Naldini,et al.  Deletion in a (T)8 microsatellite abrogates expression regulation by 3'-UTR. , 2003, Nucleic acids research.

[30]  Lichun Yang,et al.  Aberrant splicing of the ATM gene associated with shortening of the intronic mononucleotide tract in human colon tumor cell lines: A novel mutation target of microsatellite instability , 2000, International journal of cancer.

[31]  Hai-Ri Li,et al.  Topoisomerase II gene mutations in tumors and tumor cell lines with microsatellite instability. , 2004, Cancer letters.

[32]  J. Malm,et al.  Semenogelin I and II, the predominant human seminal plasma proteins, are also expressed in non-genital tissues. , 2002, Molecular human reproduction.

[33]  Y. Ionov,et al.  A role for p300/CREB binding protein genes in promoting cancer progression in colon cancer cell lines with microsatellite instability. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[34]  A. Duval,et al.  Mutations at coding repeat sequences in mismatch repair-deficient human cancers: toward a new concept of target genes for instability. , 2002, Cancer research.

[35]  Yan P. Yuan,et al.  Pathogenesis of DNA repair-deficient cancers: a statistical meta-analysis of putative Real Common Target genes , 2003, Oncogene.

[36]  D. Glavač,et al.  Identification of novel genes with somatic frameshift mutations within coding mononucleotide repeats in colorectal tumors with high microsatellite instability , 2003, Genes, chromosomes & cancer.

[37]  L. Aaltonen,et al.  Microsatellite marker analysis in screening for hereditary nonpolyposis colorectal cancer (HNPCC). , 2001, Cancer research.

[38]  H. Yamamoto,et al.  Germline and somatic mutations in hMSH6 and hMSH3 in gastrointestinal cancers of the microsatellite mutator phenotype. , 2001, Gene.

[39]  H. Lilja,et al.  A frequent allele codes for a truncated variant of semenogelin I, the major protein component of human semen coagulum. , 2003, Molecular human reproduction.

[40]  K. Kinzler,et al.  Clues to the pathogenesis of familial colorectal cancer. , 1993, Science.

[41]  H. Koistinen,et al.  Monoclonal Antibodies, Immunofluorometric Assay, and Detection of Human Semenogelin in Male Reproductive Tract: No Association with In Vitro Fertilizing Capacity of Sperm1 , 2002, Biology of reproduction.

[42]  J C Reed,et al.  Somatic Frameshift Mutations in the BAX Gene in Colon Cancers of the Microsatellite Mutator Phenotype , 1997, Science.

[43]  J. Zucman‐Rossi,et al.  Frequent mutations of hepatocyte nuclear factor 1 in colorectal cancer with microsatellite instability. , 2003, Gastroenterology.

[44]  H. Lilja,et al.  Isolation and Characterization of the Major Gel Proteins in Human Semen, Semenogen I and Semenogen II , 1996 .