2026-11-092026-11-09https://scholars.csmu.edu.tw/handle/123456789/37922Exposure to environmental tobacco smoke (ETS) and cooking oil fume (COF) are suggested to be the risk factors of female lung cancer in Taiwan. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and trans-trans-2,4-decadienal (tt-DDE) are respectively the abundant carcinogen/mutagen found in ETS and COF. In addition, benzo[a]pyrene (BaP), a ligand for aryl hydrocarbon receptor (AhR), is one of these carcinogens found in ETS and COF. AhR was reported to interact with estrogen receptor. Estrogen receptor beta (ERbeta) expressed in the lung was shown to be responsive to estrogens. Androgens were demonstrated to affect pulmonary surfactant production and lung morphology. In this project, we propose that exposure to ETS and COF may alter activity and expression of AhR and steroid hormone receptors. WE found that BaP activated AhR, induced CYP1A1 but reduced AhR protein levels in lung cell lines and primary culture of small airway epithelial cells. BaP reduced both AR protein and mRNA levels, and testosterone-induced AR expression in male lung adenocarcinoma cells H1355. BaP only reduced ERbeta protein levels, but not mRNA levels, in female lung adenocarcinoma cells CL5. Antagonizing with alpha-naphthoflavone, an AhR antagonist and CYP1 inhibitor, prevented BaP-induced AR and ERbeta reduction. Inhibiting CYP1B1 activity with 2,4,3？？,5？？-tetramethoxystilbene or tyrosine phosphorylation with genestein only prevented BaP-induced AR reduction, but not ERbeta reduction. Treatment with BPDE, a carcinogenic metabolite of BaP, also reduced AR protein levels in H1355 cells. These results suggested that BaP might interfere AhR, AR and ERbeta function in the lung. The impact of AhR reduction will be investigated with a RNAi system. We will further examine effect of BaP on androgen and estrogen-responsive genes in lung cells. Since BaP increases CYP1A1 and CYP1B1 expression, we showed that BaP increased the conversion of 17beta-estradiol into 2-hydroxy- and 4-hydroxyeastradiol in bronchial epithelial cells. 2-Hydroxyestradiol was shown to produce DNA adducts and 4-hydroxyestradiol is an animal carcinogen. The effects of BaP on receptors expression and estrogen metabolism will be confirmed in human small airway epithelial cells. NNK and tt-DDE had no similar effects on these receptors. tt-DDE induced intracellular oxidative stress and oxidative DNA damage in lung cells. Furthermore, treatment with 10mM tt-DDE selectively reduced viable cell numbers in normal human bronchial epithelial cells, but not in lung cancer cells. But long-term exposure (30 days) to 1mM tt-DDE significantly increased cell growth of immortalized human bronchial epithelial cells. We will further characterize growth rate and transformation ability of 1mM tt-DDE-treated cells, and identify gene expression altered by the treatment.許多流行病學研究指出，暴露二手煙及烹飪油煙為台灣女性罹患肺癌之危險因子。4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) 及 trans-trans-2,4-decadienal (tt-DDE)分別是二手煙及烹飪油煙中被發現之致癌物或致突變物。Benzo[a]pyrene (BaP)是一種aryl hydrocarbon receptor (AhR) ligand，目前已被發現於二手煙及烹飪油煙中。本計劃以人類氣管上皮細胞 BEAS-2B，女性肺腺癌細胞CL5，男性肺腺癌細胞NCI-H1355及正常人類細支氣管上皮細胞（SAEC）為研究材料，目的為探討暴露二手煙及烹飪油煙對多環芳香烴類受器(AhR) ，荷爾蒙受器表現(AR, ER, GR)及雌性素代謝之影響。目前我們發現在所有肺細胞中BaP均能增加CYP1A1基因表現，但是降低AhR蛋白；於H1355細胞中BaP降低AR蛋白及基因表現，而AhR、CYP1B1及tyrosine phosphorylation抑制劑能阻斷此作用，直接處理BaP致癌性代謝物-BPDE也會降低AR蛋白及基因表現；於CL5細胞中BaP會降低ERbeta蛋白量，但不影響ERbeta mRNA量。由這些結果推測BaP可能影響AhR, AR and ERbeta在肺細胞之生理功能。我們將進一步以RNAi系統探討降低AhR量對細胞基因表現及生長之影響；另外也於肺細胞中探討BaP對雄性素及雌性素誘導基因表現能力之影響。既然BaP增加CYP1A1 and CYP1B1表現，我們也證實BaP在BEAS-2B細胞中能促使雌性素水解而形成2-OHE2 and 4-OHE2。其中2-OHE2已被證實會形成DNA adducts，而4-OHE2為已知之動物致癌物。將來我們打算在SAEC細胞中確認BaP對雌性素代謝及receptors之作用。接著我們證實NNK and tt-DDE對receptors並無相同作用。然而我們發現tt-DDE增加細胞內氧化緊迫及氧化性DNA傷害，接著tt-DDE選擇性殺死正常細胞，而非肺癌細胞。以1mM tt-DDE處理BEAS-2B細胞30天後反而增加細胞生長速度，我們將進一步確定經tt-DDE長期處理後之BEAS-2B細胞是否發生轉型？哪些基因表現發生改變?二手煙烹飪油煙benzo[a]pyrene多環芳香烴受器荷爾蒙受器benzo[a]pyrene4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonetrans-trans-24-decadienalaryl hydrocarbon receptorandrogen receptorestrogen receptorProject