Lung cancer cells induce senescence and apoptosis of pleural mesothelial cells via transforming growth factor-beta1
- 299 Downloads
Pleural dissemination is commonly associated with metastatic advanced lung cancer. The injury of pleural mesothelial cells (PMCs) by soluble factors, such as transforming growth factor-beta1 (TGF-β1), is a major driver of lung cancer pleural dissemination (LCPD). In this study, we examine the effects of TGF-β1 on PMC injury and the ability of TGF-β1 inhibition to alleviate this effect both in vitro and in vivo. PMCs were co-cultured with the high TGF-β1-expressing lung cancer cell line A549 and with various TGF-β1 signaling inhibitors. Expression of cleaved-caspase 3, cleaved-caspase 9, p21, and p16 were evaluated by Western blot and immunofluorescent confocal imaging. Apoptosis was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltrazoliumbromide assay and AnnexinV-propidium iodide (PI) staining. PMC senescence was assessed by staining for senescence-associated β-galactosidase (SA-β-Gal). The ability of lung cancer cells (LCCs) to adhere to injured PMCs was investigated using an LCC-PMC adhesion assay. In our mouse model, PMC injury status was monitored by hematoxylin–eosin (H&E) and Masson’s trichrome staining. LCCs expressing high levels of TGF-β1 induce apoptosis and senescence of PMCs in a co-culture system. Injured PMCs adhere to LCCs, which may further promote LCPD. Importantly, PMC monolayer injury could be reversed with TGF-β1 inhibitors. This was consistent with our in vivo data showing that the TGF-β1 inhibitor SB-431542 attenuated PMC barrier injury induced by A549 culture medium in our mouse model. Our study highlights the importance of TGF-β1 signaling in LCPD and establishes this signaling pathway as a potential therapeutic target in the disease.
KeywordsLung cancer Pleural metastasis TGF-β1 Mesothelial cells Senescence Apoptosis
We thank Prof. Feng Li for technical guidance and assistance. This work was supported by the National Science Foundation of China (Nos. 81272718 and 81302125).
Conflicts of interest
- 2.Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, et al. GLOBOCAN 2012 v1.0, Cancer incidence and mortality worldwide: IARC CancerBase No. 11. Lyon, France: International Agency for Research on Cancer 2013. http://globocan.iarc.fr.
- 3.Goldstraw P, Crowley J, Chansky K, Giroux DJ, Groome PA, Rami-Porta R, et al. International Association for the Study of Lung Cancer International Staging Committee; participating institutions. The IASLC lung cancer staging project: proposals for the revision of the TNM stage groupings in the forthcoming (seventh) edition of the TNM Classification of malignant tumours. J Thorac Oncol. 2007;2:706–14.CrossRefPubMedGoogle Scholar
- 4.Postmus PE, Brambilla E, Chansky K, Crowley J, Goldstraw P, Patz Jr EF, et al. International Association for the Study of Lung Cancer International Staging Committee; cancer research and biostatistics; observers to the committee; participating institutions. The IASLC lung cancer staging project: proposals for revision of the M descriptors in the forthcoming (seventh) edition of the TNM classification of lung cancer. J Thorac Oncol. 2007;2:686–93.CrossRefPubMedGoogle Scholar
- 18.Pineda JR, Daynac M, Chicheportiche A, Cebrian-Silla A, Sii Felice K, Garcia-Verdugo JM, et al. Vascular-derived TGF-β increases in the stem cell niche and perturbs neurogenesis during aging and following irradiation in the adult mouse brain. EMBO Mol Med. 2013;5:548–62.CrossRefPubMedPubMedCentralGoogle Scholar