Inactivating germ-line and somatic mutations in polypeptide N-acetylgalactosaminyltransferase 12 in human colon cancers

Kishore Guda, Helen Moinova, Jian He, Oliver Jamison, Lakshmeswari Ravi, Leanna Natale, James Lutterbaugh, Earl Lawrence, Susan Lewis, James K.V. Willson, John B. Lowe, Georgia L. Wiesner, Giovanni Parmigiani, Jill Barnholtz-Sloan, Dawn W. Dawson, Victor E. Velculescu, Kenneth W. Kinzler, Nikolas Papadopoulos, Bert Vogelstein, Joseph WillisThomas A. Gerken, Sanford D. Markowitz

Research output: Contribution to journalArticlepeer-review

103 Scopus citations


Aberrant glycosylation is a pathological alteration that is widespread in colon cancer, and usually accompanies the onset and progression of the disease. To date, the molecular mechanisms underlying aberrant glycosylation remain largely unknown. In this study, we identify somatic and germ-line mutations in the gene encoding for polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12) in individuals with colon cancer. Biochemical analyses demonstrate that each of the 8 GALNT12 mutations identified inactivates the normal function of the GALNT enzyme in initiating mucin type O-linked protein glycosylation. Two of these inactivating GALNT12 mutations were identi-fied as acquired somatic mutations in a set of 30 microsatellite stable colon tumors. Relative to background gene mutation rates, finding these somatic GALNT12 mutations was statistically significant at P < 0.001. Six additional inactivating GALNT12 mutations were detected as germ-line changes carried by patients with colon cancer; however, no inactivating variants were detected among cancer-free controls (P = 0.005). Notably, in 3 of the 6 individuals harboring inactivating germ-line GALNT12 mutations, both a colon cancer and a second independent epithelial cancer had developed. These findings suggest that genetic defects in the O-glycosylation pathway in part underlie aberrant glycosylation in colon cancers, and they contribute to the development of a subset of these malignancies.

Original languageEnglish (US)
Pages (from-to)12921-12925
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number31
StatePublished - Aug 4 2009


  • Cancer
  • Glycosylation

ASJC Scopus subject areas

  • General


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