[Role of TGF-β1 in multi-drug resistance in small cell lung cancer and its clinical significance]

To investigate the role of transforming growth factor β1 (TGF-β1) in multi-drug resistance in small cell lung cancer and its clinical significance. Methods: The mRNA and protein expressions of TGF-β1 in H69 and H69AR cells were detected by real-time PCR and Western blot, respectively. After silence of TGF-β1, the sensitivity of H69AR to drugs was detected by CCK8 assay. The expressions of TGF-β1 in lung cancer and paracarcinoma tissues were examined by QRT-PCR and immunohistochemistry. The relationship of TGF-β1 expression with clinical pathological features and prognosis of patients was studied. Results: Compared to H69, the mRNA and protein expressions of TGF-β1 in H69AR cells were significantly increased by (5.93±0.47) and (8.49±1.92) folds, respectively (P<0.01). Transfection of TGF-β1 siRNA resulted in a decrease of TGF-β1 expression by 70.432% in H69AR cells (F=21.20, P<0.01) and an increase insensitivity to chemotherapeutic agents of H69AR cells (t=4.576, P<0.05). Compare with the paracarcinoma tissues, the expression of TGF-β1 was significantly increased in small cell lung cancer tissues (t=13.925, P<0.01), which was closely related with clinical stage, chemosensitivity and overall survival (all P<0.05), but not related with gender, age (both P>0.05). Conclusion: TGF-β1 is involved in the regulation of small cell lung cancer multidrug resistance, which may be a potential marker to evaluate the chemosensitivity and clinical prognostic for small cell lung cancer.