LIMS1 Promotes Pancreatic Cancer Cell Survival Under Oxygen-Glucose Deprivation Conditions by Enhancing HIF1A Protein Translation.

Purpose: Oxygen and glucose deprivation is a common feature of the solid tumor. Regulatory network underlying the adaptation of cancer cells to the harsh microenvironment remains unclear. We determined the mechanistic role of LIM and senescent cell antigen-like-containing domain protein 1 (LIMS1) in cancer cell survival under oxygen-glucose deprivation conditions. Experimental Design: The expression level of LIMS1 was determined by IHC staining and analyzing the mRNA expression profiles from The Cancer Genome Atlas of three human solid tumors. Roles of LIMS1 in cancer cell metabolism and growth were determined by molecular and cell biology methods. A jetPEI nanocarrier was used as the vehicle for anti-LIMS1 siRNAs in mouse models of cancer therapeutics. Results: LIMS1 expression was drastically elevated in pancreatic ductal adenocarcinoma (PDAC). High LIMS1 level was associated with advanced TNM stage and poor prognosis of patients with tumor. Increased LIMS1 expression was pivotal for tumor cells to survive in the oxygenglucose deprivation conditions. Mechanistically, LIMS1 enhanced GLUT1 expression and membrane translocation, which facilitated tumor cell adaptation to the glucose deprivation stress. Furthermore, LIMS1 promoted HIF1A protein translation by activating AKT/mTOR signaling, while hypoxia-inducible factor 1 (HIF1) transactivated LIMS1 transcription, thus forming a positive feedback loop in PDAC cell adaptation to oxygen deprivation stress. Inhibition of LIMS1 with jetPEI nanocarrier-delivered anti-LIMS1 siRNAs significantly increased cell death and suppressed tumor growth. Conclusions: LIMS1 promotes pancreatic cancer cell survival under oxygen-glucose deprivation conditions by activating AKT/mTOR signaling and enhancing HIF1A protein translation. LIMS1 is crucial for tumor adaptation to oxygenglucose deprivation conditions and is a promising therapeutic target for cancer treatment.