Modulation of tumour associated antigen expressed on human squamous cell carcinoma cell lines by recombinant interferon-α

Abstract

Our earlier studies have shown that monoclonal antibody (Mab) 3F8E3 generated against a head and neck cancer cell line LICR-LON-HN₂ showed reactivity with squamous cell carcinoma (SCC) irrespective of the tissue of origin and identified antigens on SCC cell lines AW 13516 and AW 8507. The affinity constants (K_a) for binding of Mab 3F8E3 to AW 13516 and AW 8507 cell lines were 6.2 × 10⁸ and 4.3 × 10⁸ mol/l and it identified 6.8 × 10⁴ and 3.77 × 10⁴ sites/cell, respectively, as determined by Scatchard analysis. Treatment of both the cell lines with recombinant human interferon-α (rHu-IFNα) increased the binding affinity of the Mab but did not increase the number of binding sites on the SCC cell lines. Shedding of antigen recognised by the Mab in the culture supernatant of the cell lines was reduced after rHu-IFNα treatment. The results suggest that rHu-IFNα may bring about a firm anchorage of the tumour associated antigen on the SCC cells. Cells modulated with rHu-IFNα may serve as better targets for assessing cell mediated as well as Mab mediated cytotoxicity in oral cancer patients.