Prognostic utility of serum alpha-N-acetylgalactosaminidase and immunosuppression resulted from deglycosylation of serum Gc protein in oral cancer patients

Cancer Res. 1997 Jan 15;57(2):295-9.

Abstract

Vitamin D3-binding protein (Gc protein), a serum glycoprotein, is the precursor for the macrophage activating factor. Cancer patient sera contain alpha-N-acetylgalactosaminidase that deglycosylates Gc protein. Deglycosylated Gc protein cannot be converted to macrophage activating factor, leading to immunosuppression. Of 46 oral cancer patients with squamous cell carcinoma, approximately 22% had greatly reduced precursor activities. The precursor activity of approximately 61% of these patients was moderately reduced. The remaining patients (17%) had precursor activities equivalent to those of healthy humans. Patients with low precursor activity of serum Gc protein had high serum alpha-N-acetylgalactosaminidase activity. In contrast, patients with high precursor activity had low serum alpha-N-acetylgalactosaminidase activity. Thus, levels of serum alpha-N-acetylgalactosaminidase of individual patients have an inverse correlation with precursor activities of their serum Gc protein. Surgical removal of tumors resulted in a subtle decrease in serum alpha-N-acetylgalactosaminidase activity with concomitant increase in the precursor activity of serum Gc protein. Serum enzyme analysis of nude mice transplanted with a human oral squamous carcinoma cell line revealed that serum alpha-N-acetylgalactosaminidase activity is directly proportional to tumor burden. Thus, alpha-N-acetylgalactosaminidase activity in patient bloodstream can serve as a diagnostic/prognostic index.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Neoplasm / blood
  • Carcinoma, Squamous Cell / immunology*
  • Carcinoma, Squamous Cell / pathology
  • Female
  • Glycosylation
  • Hexosaminidases / blood*
  • Humans
  • Immunosuppression Therapy*
  • Macrophage-Activating Factors / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Mouth Neoplasms / immunology*
  • Mouth Neoplasms / metabolism*
  • Mouth Neoplasms / pathology
  • Neoplasm Proteins / blood
  • Neoplasm Proteins / metabolism*
  • Prognosis
  • Serpins*
  • Vitamin D-Binding Protein / blood
  • Vitamin D-Binding Protein / metabolism*
  • alpha-N-Acetylgalactosaminidase

Substances

  • Antigens, Neoplasm
  • Macrophage-Activating Factors
  • Neoplasm Proteins
  • Serpins
  • Vitamin D-Binding Protein
  • squamous cell carcinoma-related antigen
  • Hexosaminidases
  • NAGA protein, human
  • alpha-N-Acetylgalactosaminidase