Analyzing the impact of the tumor microenvironment remodeling on activation of autophagy pathways in non-small cell lung cancer
Background and previous work
Autophagy is a major catabolic process, which is essential in maintaining cellular homeostasis. The role of autophagy in tumor growth is determined by the specific features of tumor cells such as tumor type, stage, differentiation, genetic/epigenetic background, and the tumor microenvironment (TME) with the overall effect being either tumor-promoting or tumor-suppressing. The TME is the complex ecosystem containing cancer cells, non-cancerous cells such as immune cells, fibroblasts, adipocytes, and endothelial cells, secretory molecules, as well as the extracellular matrix (ECM). A body of evidence shows that the TME activates autophagy to facilitate cancer cell growth, and autophagy, in turn, shapes the TME to promote tumor development. However, the precise mechanisms have not yet been clarified.
In our previous studies, we identified several autophagy proteins such as LC3I, LC3II, and beclin-1 as potential diagnostic and prognostic markers in lung cancer. Recently, we have found that the expression of lipid metabolic proteins such as fatty acid binding proteins (FABPs) and long-chain acyl-CoA synthetases (ACSLs) as well as fibroblast markers such as fibronectin were significantly associated with autophagy markers like p62, Beclin-1, LC3I, and LC3II in primary non-small cell lung cancer (NSCLC) patient samples. Co-culture of the fibroblast cell line 3T3-L1-differentiated adipocytes with NSCLC cells led to significantly altered expression levels of FABPs, p62, beclin-1, LC3I, LC3II, and bcl-2 in NSCLC cells, along with lipid metabolic reprogramming in vitro. The data suggest that lipid metabolism, extracellular matrix reorganization, and autophagy may be closely involved in the lung TME rewiring, despite that lung is not a primarily fatty organ. Therefore, our hypothesis is that interactions of adipocytes/tumor cells and fibroblasts/tumor cells may influence autophagy in the TME, leading to tumor cell progression and metastasis.
Specific aims
understand, if and how the interaction between adipogenic / fibrogenic TME and NSCLC cells influences autophagy in tumor cells and non-tumor cells within the TME.
understand, if and how the co-culture induced modulation of autophagy has influence on tumor biological behavior in NSCLC.
understand, how the interaction of tumor cells with adipocytes / fibroblasts influences the autophagic, adipogenic and fibrotic pathways.
understand, if in vitro results can be confirmed in primary lung cancer samples
Working programme
Establishing fibroblast cell line 3T3-L1-differentiated adipocytes. Co-culture of adipocytes/tumor cells and fibroblasts/tumor cells w/wo nutrient starvation
Expression analysis of autophagy markers (p62, beclin-1, LC3I/II, etc.), adipogenic proteins (FABPs, CD36, ACSLs, FASN etc.), and ECM proteins (fibronectin, integrins, tenascin, MMPs, etc.) by RT-qPCR and Western blotting
Performing cell-based functional assays (MTT, migration/invasion, seahorse, mitochondrial staining)
Analysis of the markers identified from in vitro co-culture models selectively by using immunohistochemistry and multiplexing immunofluorescence in primary lung cancer samples
References:
Ma Y, Nenkov M, Berndt A, Abubrig M, Schmidt M, Sandhaus T, Huber O, Clement JH, Lang SM, Chen Y, Gaßler N. The Diagnostic Value of ACSL1, ACSL4, and ACSL5 and the Clinical Potential of an ACSL Inhibitor in Non-Small-Cell Lung Cancer. Cancers (Basel). 2024 Mar 16;16(6):1170. doi: 10.3390/cancers16061170.
Ma Y, Nenkov M, Schröder DC, Abubrig M, Gassler N, Chen Y. Fibulin 2 Is Hypermethylated and Suppresses Tumor Cell Proliferation through Inhibition of Cell Adhesion and Extracellular Matrix Genes in Non-Small Cell Lung Cancer. Int J Mol Sci. 2021 Oct 31;22(21):11834. doi: 10.3390/ijms222111834.
Chen Y, Schnitzler K, Ma Y, Nenkov M, Theis B, Petersen I. The clinical influence of autophagy-associated proteins on human lung cancer. Disease Markers 2018; 2018:8314963. doi: 10.1155/2018/8314963.
Principal investigator
PD Dr. Y. Chen, Prof. Dr. N. Gaßler (Section Pathology of the Institute of Forensic Medicine)