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Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc

Tongzhong Ju1, Grainger S Lanneau, Tripti Gautam

  • 1Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, USA. tju@emory.edu

Cancer Research
|March 15, 2008
PubMed

Insights

Somatic mutations in the Cosmc gene cause loss-of-function, leading to altered cell surface carbohydrate antigen expression. This discovery impacts understanding of tumor-associated antigens like Tn and sialyl Tn (STn) in various cancers.

Area of Science:

  • Biochemistry
  • Oncology
  • Glycobiology

Background:

  • Neoplastic lesions express specific carbohydrate antigens on glycoproteins.
  • These antigens, like Tn and sialyl Tn (STn), are epigenetically controlled and can be lost under therapeutic pressure.

Purpose of the Study:

  • To investigate the genetic basis for the expression of Tn and sialyl Tn (STn) tumor-associated carbohydrate antigens.
  • To identify the molecular mechanisms underlying global alterations in cell surface carbohydrate antigen expression in cancer.

Main Methods:

  • Analysis of somatic mutations in the Cosmc gene in cancer cell lines and patient specimens.
  • Assessment of Tn and STn antigen expression.
  • Investigation of Cosmc locus integrity and heterozygosity.

Main Results:

  • Loss-of-function mutations in the Cosmc gene were identified as the cause of Tn and STn antigen expression in colon cancer and melanoma cell lines.
  • Human cervical cancer specimens with Tn/STn expression also showed Cosmc mutations and loss of heterozygosity.
  • This study demonstrates somatic mutations in Cosmc lead to global changes in cell surface carbohydrate antigen expression across diverse cancers.

Conclusions:

  • Somatic mutations in Cosmc are responsible for the aberrant expression of Tn and STn antigens in various cancers.
  • The findings provide a molecular explanation for altered cell surface glycosylation in neoplastic lesions.
  • This research offers new insights into the epigenetic regulation and therapeutic implications of tumor-associated carbohydrate antigens.

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