Effects Of C-myc Antisense Oligodeoxynucleotides Or Combined With Hexamethylene Bisacetamide On The Malignant Phenotype Of Human Mucoepidermoid Carcinoma Cell MEC-1

Mucoepidermoid carcinoma is the most common malignant disease in salivary gland. By now, surgery, radiotherapy and chemotherapy still are the major approaches. With the development and application of modern molecular biology techniques, gene therapy supplies a new way to treat it.C-myc, coding a DNA-binding protein weighting 62 KD, plays an important role in cell proliferation and differentiation. It is one of immediate-early gene indispensable to cell proliferation, and its product is a trans-acting transcription factor that drives the cells from G₀/G₁ phase into S phase. Activation of c-myc is related to carcinogenesis of a lot of carcinomas. Besidespromoting cell proliferation and transformation, it also can inhibit cell differentiation. There are C-myc amplification and overexpression in mucoepidermoid carcinoma. Therefore, blocking the overexpression of c-myc with antisense oligodeoxynucleotides (ASODN) may provide new approach to treat this disease. From translation initiation region of second extron of human c-myc gene 15-Mer antisense, sense, and mismatched oligonucleotides (Oligomers) were synthesized and modified with phosphorothioate. The present study observed the effects of c-myc ASODN alone or combined with hexamethylene bisacetamide (HMBA) on the malignant phenotypes of human mucoepidermoid carcinoma MEC-1 cell with MTT assay, clonic assay, ³H-TdR incorporation assay, morphologic observation, laser scanning confocal microscope observation, immunohistochemical staining, TUNEL staining, flow cytometry,...