Thyroid hormone receptor α1 acts as a new squamous cell lung cancer diagnostic marker and poor prognosis predictor: Can it be a novel therapeutic target?

e20508 Background: Lung cancer is considered the first cause of cancer-related death worldwide. Unfortunately, all therapeutic regimens used in lung cancer treatment showed relatively equivalent efficacy. The search and subsequent testing of new therapeutic targets that can be used alternative to, after the failure of or in association with the currently used therapeutics to improve the prognosis is an urgent demand and consequently a very interesting era of oncological lung research. Up to date, it is known that Thyroid hormones and Thyroid hormone receptors (THRs) controls many tumors progression, nevertheless, its role in non-Small Cell Lung cancer (NSCLC) is not yet defineltly understood. This study investigated the expression of Thyroid hormone receptor alpha 1 (THRα1) in NSCLC cases. Methods: Immunohistochemistry using THRα1 antibody was performed on tissue sections collected from 80 patients diagnosed with NSCLC. We also analyzed the expression of THRα gene in Microarrays of squamous cell lung carcinoma (SCC) and adenocarcinoma (AC) patients by using GEO datasets on https://www.ncbi.nlm.nih.gov. Results: We showed, for the first time, the expression of THRa1 in NSCLC. Intermediate and high THRa1 expression was detected in (25% and 66.7%) of SCC cases respectively. High THRa1 expression was associated with shorter OS and poor prognosis. On the other hand, 86.7% of AC cases revealed low THRa1expression. By analyzing GEO data sets, a significant increase in THRa gene value was found in SCC compared to AC cases. Inflammatory cells in SCC cases showed high THRα1 expression. Conclusions: Our study is shedding a new light on the relevance of THRα1 in lung cancer not only as a possible prognostic marker but also as an innovative diagnostic additive tool for lung squamous cell carcinoma which could be tested as a therapeutic target as well.