Inhibition of tumorigenicity in lung adenocarcinoma cells by c‐erbB‐2 antisense expression

The lung carcinoma cell line Calu3, which overexpresses the c‐erbB‐2 oncogene, was stably transfected with antisense (AS) cDNA constructs encompassing different regions of the c‐erbB‐2 gene. Transfected cells were analyzed for their tumorigenic properties in vitro and in nude mice. Two independent clones, AS F1 (low erbB‐2 expressor) and AS B12 (high erbB‐2 expressor), as well as the polyclonal Calu3/AS 5′, were selected for these analyses. In Calu3/AS 5′ transfected cells and in the AS F1 clone, c‐erbB‐2 RNA and protein levels were lower than those detected in the parental cell line and the AS B12 clone. Anchorage‐independent growth and tumor take were also significantly reduced. Furthermore, cells derived from primary tumors of Calu3/AS 5′, AS F1 and AS B12 lost the AS c‐erbB‐2 DNA insert but retained the gene for G418 resistance. Our results suggest that a correlation between c‐erbB‐2 overexpression and tumorigenicity may exist in the Calu3 lung carcinoma cell line. Int. J. Cancer 72:631–636, 1997. © 1997 Wiley‐Liss, Inc.