Medicine and Health Sciences Commons^™

Upregulation Of Cpt1a Is Essential For The Tumor-Promoting Effect Of Adipocytes In Colon Cancer, Xiaopeng Xiong, Yang-An Wen, Rachelle Fairchild, Yekaterina Y. Zaytseva, Heidi L. Weiss, B. Mark Evers, Tianyan Gao

Markey Cancer Center Faculty Publications

Colon tumors grow in an adipose tissue-enriched microenvironment. Locally advanced colon cancers often invade into surrounding adipose tissue with a direct contact with adipocytes. We have previously shown that adipocytes promote tumor growth by modulating cellular metabolism. Here we demonstrate that carnitine palmitoyltransferase I (CPT1A), a key enzyme controlling fatty acid oxidation (FAO), was upregulated in colon cancer cells upon exposure to adipocytes or fatty acids. In addition, CPT1A expression was increased in invasive tumor cells within the adipose tissue compared to tumors without direct contact with adipocytes. Silencing CPT1A abolished the protective effect provided by fatty acids against nutrient …

Downregulation Of Srebp Inhibits Tumor Growth And Initiation By Altering Cellular Metabolism In Colon Cancer, Yang-An Wen, Xiaopeng Xiong, Yekaterina Y. Zaytseva, Dana L. Napier, Emma Vallee, Austin T. Li, Chi Wang, Heidi L. Weiss, B. Mark Evers, Tianyan Gao

Markey Cancer Center Faculty Publications

Sterol regulatory element-binding proteins (SREBPs) belong to a family of transcription factors that regulate the expression of genes required for the synthesis of fatty acids and cholesterol. Three SREBP isoforms, SREBP1a, SREBP1c, and SREBP2, have been identified in mammalian cells. SREBP1a and SREBP1c are derived from a single gene through the use of alternative transcription start sites. Here we investigated the role of SREBP-mediated lipogenesis in regulating tumor growth and initiation in colon cancer. Knockdown of either SREBP1 or SREBP2 decreased levels of fatty acids as a result of decreased expression of SREBP target genes required for lipid biosynthesis in …

Adipocytes Activate Mitochondrial Fatty Acid Oxidation And Autophagy To Promote Tumor Growth In Colon Cancer, Yang-An Wen, Xiaopeng Xing, Jennifer W. Harris, Yekaterina Y. Zaytseva, Mihail I. Mitov, Dana L. Napier, Heidi L. Weiss, B. Mark Evers, Tianyan Gao

Markey Cancer Center Faculty Publications

Obesity has been associated with increased incidence and mortality of a wide variety of human cancers including colorectal cancer. However, the molecular mechanism by which adipocytes regulate the metabolism of colon cancer cells remains elusive. In this study, we showed that adipocytes isolated from adipose tissues of colon cancer patients have an important role in modulating cellular metabolism to support tumor growth and survival. Abundant adipocytes were found in close association with invasive tumor cells in colon cancer patients. Co-culture of adipocytes with colon cancer cells led to a transfer of free fatty acids that released from the adipocytes to …

Phlpp Regulates Hexokinase 2-Dependent Glucose Metabolism In Colon Cancer Cells, Xiaopeng Xiong, Yang-An Wen, Mihail I. Mitov, Mary C. Oaks, Shigeki Miyamoto, Tianyan Gao

Markey Cancer Center Faculty Publications

Increased glucose metabolism is considered as one of the most important metabolic alterations adapted by cancer cells in order to generate energy as well as high levels of glycolytic intermediates to support rapid proliferation. PH domain leucine-rich repeat protein phosphatase (PHLPP) belongs to a novel family of Ser/Thr protein phosphatases that function as tumor suppressors in various types of human cancer. Here we determined the role of PHLPP in regulating glucose metabolism in colon cancer cells. Knockdown of PHLPP increased the rate of glucose consumption and lactate production, whereas overexpression of PHLPP had the opposite effect. Bioenergetic analysis using Seahorse …

No Association Of Obesity And Type 2 Diabetes Mellitus Related Genetic Variants With Colon Cancer, Cheryl L. Thompson, Sarah J. Plummer, Thomas C. Tucker, Graham Casey, Li Li

Markey Cancer Center Faculty Publications

Background: Obesity and type 2 diabetes mellitus (T2D) are known risk factors for colon cancer. Recent reports from a number of genome wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with obesity and T2D. Here we tested the hypothesis that these SNPs may also be associated with risk of colon cancer.

Methods: We genotyped nine SNPs reported in GWAS of obesity and/or T2D, including SNPs in HHEX, KCNJ11, SLC30A8, FTO, CDKN2, CDKAL1, TCF2, and the rs9300039 SNP in an intergenic region, in 561 colon cancer cases and 721 population controls.

Results: None of these SNPs were …