Transcriptional changes in response to 17β-estradiol, cigarette sidestream smoke particulates, and TNFα treatments in ERα-induced and uninduced CL1-5(TO-ERα) cells. Homo sapiens

This microarray analysis was designed to determine (1) the impact of ERα expression on cellular TNFα response and estrogen-TNFα signaling crosstalk and (2) whether cigarette sidestream smoke particulates had estrogen-like action in human lung adenocarcinoma cells. The lung adenocarcinoma cell line CL1-5(TO-ERα)#18 was used as a model. Expression of ERα in this cell line is under Tet-on regulation and can be induced by addition of doxycycline. For the Objective 1, we found three types of TNFα responsive genes: estrogen/ERα-dependent, estrogen/ERα-enhanced, and estrogen/ERα-independent. For the Objective 2, the microarray data revealed that cigarette sidestream smoke particulates regulated given genes via ERα as 17β-estradiol in lung adenocarcinoma cells. Some of these ERα target genes had been identified previously. Overall design: Expression of ERα in CL1-5(TO-ERα)#18 was induced 24 h before treatment by addition of 1 μg/ml doxycycline (D) to cells. To determine the TNFα response in the presence and absence of ERα (Objective 1-1), ERα-induced and uninduced CL1-5(TO-ERα)#18 cells were treated with and without 45 U/ml TNFα (T) for 24 h. 1 nM 17β-estradiol (E) was also given to ERα-induced cells by itself or together with 45 U/ml TNFα to examine the estrogen-TNFα signaling crosstalk (Objective 1-2). Transcript levels were compared among the following treatments: D-E-T-, D-E-T+, D+E-T-, D+E-T+, D+E+T-, and D+E+T+. To compare the transcriptional effecs of 17β-estradiol and cigarette sidestream smoke particulates (Objective 2), ERα-induced and uninduced CL1-5(TO-ERα)#18 cells were treated with 1 nM 17β-estradiol (E), 20 μg/ml cigarette sidestream smoke particulates (C), or neither for 24 h. The treatments for Objective 2 were labeled as D-E-T-, D-E+T-, D-C+T-, D+E-T-, D+E+T-, and D+C+T-. Each treatment had two independent samples for microarray analysis (n=2).