Carnitine Palmitoyltransferase 1 Regulates Prostate Cancer Growth under Hypoxia

Cancers

Yixin Su¹  Susy Kim¹  Pawan Kumar¹  Gagan Deep¹  Liang Liu¹  Sangeeta Singh¹  Leslimar Rios-Colon¹  Nalexus Stocks¹  Mitu Sharma¹  Ashish Kumar¹  Isabel R. Schlaepfer²  Molishree Joshi³  Deepak Kumar⁴ 

[1] Department of Cancer Biology, Wake Forest Baptist Medical Center, Winston-Salem, NC 27157, USA;Division of Medical Oncology, University of Colorado Anschutz Medical Center, Aurora, CO 80045, USA;Functional Genomics Facility, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, NC 27707, USA;

关键词: prostate cancer;    hypoxia;    carnitine palmitoyltransferase;    sphere;    xenograft;   

DOI  :  10.3390/cancers13246302

来源: DOAJ

【 摘 要 】

Hypoxia and hypoxia-related biomarkers are the major determinants of prostate cancer (PCa) aggressiveness. Therefore, a better understanding of molecular players involved in PCa cell survival under hypoxia could offer novel therapeutic targets. We previously reported a central role of mitochondrial protein carnitine palmitoyltransferase (CPT1A) in PCa progression, but its role in regulating PCa survival under hypoxia remains unknown. Here, we employed PCa cells (22Rv1 and MDA-PCa-2b) with knockdown or overexpression of CPT1A and assessed their survival under hypoxia, both in cell culture and in vivo models. The results showed that CPT1A knockdown in PCa cells significantly reduced their viability, clonogenicity, and sphere formation under hypoxia, while its overexpression increased their proliferation, clonogenicity, and sphere formation. In nude mice, 22Rv1 xenografts with CPT1A knockdown grew significantly slower compared to vector control cells (~59% reduction in tumor volume at day 29). On the contrary, CPT1A-overexpressing 22Rv1 xenografts showed higher tumor growth compared to vector control cells (~58% higher tumor volume at day 40). Pathological analyses revealed lesser necrotic areas in CPT1A knockdown tumors and higher necrotic areas in CPT1A overexpressing tumors. Immunofluorescence analysis of tumors showed that CPT1A knockdown strongly compromised the hypoxic areas (pimonidazole+), while CPT1A overexpression resulted in more hypoxia areas with strong expression of proliferation biomarkers (Ki67 and cyclin D1). Finally, IHC analysis of tumors revealed a significant decrease in VEGF or VEGF-D expression but without significant changes in biomarkers associated with microvessel density. These results suggest that CPT1A regulates PCa survival in hypoxic conditions and might contribute to their aggressiveness.

【 授权许可】

Unknown