Association of interferon-γ induced growth inhibition and modulation of epidermal growth factor receptor gene expression in squamous cell carcinoma cell lines

Interferons (IFN) possess the ability to inhibit proliferation of certain transformed cell lines. Down modulation of the abnormal expression of certain oncogenes by IFN has been associated with phenotypic reversion of src, myc, or ras transformed cells. It has already been shown that some squamous cell carcinoma (SCCa) cell lines express elevated levels of the epidermal growth factor receptor (EGFR). Previously, in A431, an SCCa cell line, it was shown that IFN-γ-induced growth inhibition was associated with both enhanced expression of EGFR and terminal differentiation. This study examines the effect of IFN-β or IFN-γ on five additional cervical SCCa cell lines. One cell line was shown to have amplification of the EGFR gene. An IFN-γ induced antiproliferative response, observed in four of the five cell lines, was associated with increased expression of EGFR mRNA and induction of the IFN-inducible genes, HLA-A3 class I antigen and 2-5 oligoadenylate synthetase. These data suggest that the increased expression of the EGFR gene in a particular SCCa may predict response to IFN-γ.