| Transforming growth factorα (TGFα) is a polypeptide growth factor produced mainly by a variety of malignant cel types ( renal carcinoma, melanoma, etc.) and known to bind the epidermal growth factor receptor (EGFR) on cell surface in due form of autocrine mechanism. Elevation of the TGFα in body fluids may suggest the possible presence of tumor growth. However, the pathological significance of TGFα in human glioma seems to be paradoxical in so far reported literatures. Therefore. it is important to find out further any changes in TGFα and related genes in glioma and to correct them by biotechnological approaches for therapeutic purpose. IIn this report, a plasmid phTGF-1 —10—925. consisting of pBR327 vectorwith a 925 bp TGFα cDNA fragment cloned at its EcoRI site, was first digested with EcoRI and EcoRI plus PstI respectively. This plasmid, proved to be correct by the restriction pattern was taken as a template for the polymerase chain reaction (PCR) of TGFα -IV exon fragment. DNA sequencing of the PCR product demonstrated the fidelity of the amplified fragment.Using phTGF-1-10-925 and phc-myc as probes, the gene changes of TGFα and c-myc in two glioma cell lines, BT325 and SHG44, as well as several surgical specimens of human glioma were observed. The results indicated that TGFα gene was overexpressed rather than amplified in glioma, whereas there were amplification, rearrangement, and overexpression of c-myc protooncogene. The expression levels of these two genes were shown to be parallel.A N-terminal hepta-peptide of TGFα(VVSHFND) was chemically synthesized and coupled with BSA to form a complete antigen. Antibodies were prepared by immunizing rabbits with this conjugate, and immunoassay showed that the immunoabsorbed antiserum recognized only the single epitope of hepta-peptide. No cross reaction with EGF was observed. By adding this antiserum into cell...
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