CD24, a signal-transducing molecule expressed on human B cells, is a major surface antigen on small cell lung carcinomas

Cancer Res. 1992 Oct 1;52(19):5264-70.

Abstract

Cell lines derived from human small cell carcinoma of the lung express high levels of a surface polypeptide termed the cluster-w4 antigen, which was previously identified as a potential target for toxin-based immunotherapy of lung cancer. We have cloned a complementary DNA encoding the cluster-w4 antigen from COS-1 fibroblasts transfected with a SW2 small cell carcinoma library, by panning with a mixture of the cluster-w4-specific monoclonal antibodies SWA11, SWA21, and SWA22. The sequence of the cluster-w4 complementary DNA encodes an unusually short (80-amino acid) protein identical to that recently reported for the leukocyte activation molecule CD24 except for a single valine-alanine substitution due to a single-base polymorphism within the region of the gene coding for the extracellular domain. Biochemical analyses of the cloned cluster-w4 antigen confirmed both the presence of the phosphatidylinositol tail and the extensive glycosylation reported for the CD24 molecule. Furthermore, the cloned cluster-w4 antigen expressed on COS cells was shown to react with a comprehensive panel of CD24-specific monoclonal antibodies, as assessed by indirect immunofluorescence staining. Northern blot hybridization indicated the presence of several transcript sizes for the cluster-w4 antigen that were greatly overexpressed in small cell carcinoma cell lines, compared with normal hemopoietic cells and CD24-positive cell lines. Southern blot hybridization of restriction digests of genomic DNA identified a complex pattern of bands consistent with either a complex gene structure containing many exons or the presence of a family of closely related genes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / genetics
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal
  • Antigens, CD / genetics*
  • Antigens, CD / physiology
  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / physiology
  • Antigens, Surface / genetics*
  • B-Lymphocytes / immunology
  • B-Lymphocytes / physiology*
  • Base Sequence
  • CD24 Antigen
  • Carcinoma, Small Cell / genetics
  • Carcinoma, Small Cell / immunology*
  • Cloning, Molecular
  • DNA, Neoplasm / genetics
  • DNA, Neoplasm / isolation & purification
  • Humans
  • Lung Neoplasms / genetics
  • Lung Neoplasms / immunology*
  • Membrane Glycoproteins*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Molecular Weight
  • Sequence Homology
  • Signal Transduction / physiology*
  • Valine / genetics

Substances

  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, Neoplasm
  • Antigens, Surface
  • CD24 Antigen
  • CD24 protein, human
  • Cd24a protein, mouse
  • DNA, Neoplasm
  • Membrane Glycoproteins
  • Valine
  • Alanine

Associated data

  • GENBANK/S44888
  • GENBANK/S72766
  • GENBANK/S72767
  • GENBANK/S72768
  • GENBANK/S72769
  • GENBANK/S72771
  • GENBANK/S94172
  • GENBANK/S94173
  • GENBANK/X63098
  • GENBANK/X68640