El microambient tumoral a la patogènesi del càncer de pulmò: un indici sobre els agents terapèutics i la influència de la malaltia pulmonar obstructiva crònica
- Autores: Jun Tang
- Directores de la Tesis: Esther Barreiro (dir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2021
- Idioma: español
- Tribunal Calificador de la Tesis: Jaume Ferrer Sancho (presid.), Joaquin Gea Guiral (secret.), Miguel López Botet (voc.)
- Programa de doctorado: Programa de Doctorado en Medicina por la Universidad Autónoma de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Background: Lung cancer (LC) is a leading cause of death worldwide. Chronic obstructive pulmonary disease (COPD) is a highly prevalent lung disease. COPD has been well established as an independent risk factor for lung tumorigenesis in patients. However, the biological mechanisms that explain the possible associations between lung cancer and COPD remain to be fully elucidated.
Hypothesis: The tumor microenvironment components (immune profile, stroma, cytokines, and PARP activation) may differ in tumors of lung cancer patients with and without COPD. Immunotherapy may also reduce tumor burden through several biological events.
Objectives: 1) Studies in patients: to elucidate the role of the biological events: tumor microenvironment, immune cell composition, stroma characteristics, and PARP overactivation in the process of tumorigenesis in tumors of patients with and without underlying COPD; 2) Mouse study: to evaluate the effects of immunotherapy on tumor burden through the analyses of several biological mechanisms such as oxidative stress, apoptosis, and autophagy.
Methods: Two models were used: 1) Studies in patients: 90 LC patients with underlying COPD and 43 LC-only patients were recruited from 2008 to 2019 from the Lung Cancer Mar Cohort, Barcelona. Lung tumor and the surrounding non-tumor lung specimens were obtained from all study patients through thoracotomy or video-assisted thoracoscopic surgery (VATS) prior to chemotherapy and/or radiotherapy; 2) Mouse study: Two groups of wild-type BALB/C mice with experimental lung cancer (subcutaneous inoculation of LP07 adenocarcinoma cells in the left flank of mice) were established: treated and non-treated mice, n=9/group. In the treatment group, lung cancer mice were treated with a cocktail of monoclonal antibodies (intraperitoneal injection, anti-PD-L1, anti-CTLA-4, anti-CD19, and anti-CD137). Lung tumors were obtained from all mice. Biological analysis: laboratory techniques such as western-blot, immunohistochemistry, ELISA, cell culture, and immunofluorescence were used to assess the target biological markers in each study.
Results: 1) Studies in patients: lung tumors of patients with underlying COPD showed lower levels of tertiary lymphoid structures (TLSs) compared to lung cancer only patients. Moreover, lower levels of TLS and B cells in lung tumors were associated with poorer 10-year overall survival rates of patients, especially in those with underlying COPD. In tumor stroma, the presence of COPD did not elicit any significant difference in levels of extracellular matrix, cancer-associated fibroblasts or endothelial cells. In addition, DNA damage and PARP activation levels were higher only in lung tumors of patients with underlying COPD, while PARP-1 and PARP-2 enzyme expression levels were lower in lung tumors compared to non-tumor specimens irrespective of the presence of COPD. 2) Mouse study: treatment with immunotherapy reduced tumor burden through increased levels of oxidative stress, apoptosis, autophagy, and signaling pathways such as NF-kB and sirtuin-1 in tumors of the treated mice compared to tumors of non-treated animals.
Conclusions: Tumor immune microenvironment, stroma components, and PARP are differentially expressed in lung tumors of lung cancer patients with underlying COPD. The reduction in TLS and GC formation, the rise in DNA damage, and PARP overactivation probably contribute to the greater susceptibility of COPD patients to develop lung tumors. In mice treated with the combination of monoclonal antibodies, increased levels of oxidative stress along with activated apoptosis and autophagy may be part of the mechanisms whereby immunotherapy may reduce tumor burden. In conclusion, the presence of COPD should be considered when designing therapeutic strategies of lung cancer including immunotherapy as well as PARP activity inhibition.
