Expression profile comparison between paired tumor- and normal tissue-associated MSCs from lung carcinoma patients

Lung cancer is a highly malignant tumor and the majority of cancer-related deaths are due to metastasis. The tumor microenvironment (TME) plays a fundamental role in the metastatic spread of tumor cells. Among other stromal cells, mesenchymal stem cells (MSCs) are known to be present within the TME and to be involved in cancer progression. However the majority of previous studies have been performed on bone marrow-derived MSCs. To investigate the role of the TME on the pulmonary MSC phenotype, we compared the expression profile of paired MSCs isolated from lung tumor (T-) and normal adjacent tissues (N-) from lung carcinoma patients. We used microarray data to find differentially expressed genes between N- and T-MSCs and identified several genes associated with poor prognosis that are more highly expressed in T- than in N-MSCs and potentially involved in the MSC promotion of lung cancer metastasis. MSCs were isolated from paired lung tumor (T-) and normal tissues (N-) from 9 patients diagnosed with lung carcinoma and characterized for surface expression markers and differentiation potential. RNA was extracted at culture passage 5 or 6 from fresh MSCs (frozen in DMSO-FBS10%) to be sure to have pure MSC cell culture representative of the pathophysiological characteristics of the primary samples. Paired N- and T-MSC expression profiles were analyzed using Affymetrix microarrays. We sought to identify differentially expressed genes between N- and T-MSCs to gain insight into the mechanisms whereby the stroma promotes lung cancer metastasis.