Differential utilization of the SV40 enhancer and early promoter in various human lung carcinoma cell lines

Cell lines derived from the major morphological types of human lung cancer were tested for their ability to utilize the SV40 enhancer/early promoter. These cell lines were transfected with a recombinant plasmid containing a reporter gene, coding for chloramphenicol acetyltransferase (CAT), under the control of the SV40 enhancer/early promoter. The transfected cells were then assayed for CAT activity. Non-small-cell carcinomas, especially squamous carcinomas, were found to be 2-3 orders of magnitude more efficient in utilizing the SV40 enhancer/early promoter than small-cell carcinomas. The presence of different SV40 enhancer/early promoter specific DNA-binding nuclear factors in squamous and small-cell carcinomas was demonstrated in gel mobility shift experiments. These observations seem to suggest that the set of transcriptional regulatory factors associated with squamous carcinomas may be distinct from that associated with small-cell carcinomas.