MUC1 mucin stabilizes and activates hypoxia-inducible factor 1 alpha to regulate metabolism in pancreatic cancer

Authors

Nina V. Chaika, University of Nebraska Medical CenterFollow
Teklab Gebregiworgis, University of Nebraska-LincolnFollow
Michelle E. Lewallen, University of Nebraska Medical Center
Vinee Purohit, University of Nebraska Medical Center
Prakash Radhakrishnan, University of Nebraska Medical CenterFollow
Xiang Liu, University of Nebraska Medical Center
Bo Zhang, University of Nebraska-LincolnFollow
Kamiya Mehla, University of Nebraska Medical CenterFollow
Roger B. Brown, University of Nebraska Medical Center
Thomas Caffrey, University of Nebraska Medical Center
Fang Yu, University of Nebraska Medical CenterFollow
Keith R. Johnson, University of Nebraska Medical Center
Robert Powers, University of Nebraska-LincolnFollow
Michael A. Hollingsworth, University of Nebraska Medical Center
Pankaj K. Singh, University of Nebraska Medical CenterFollow

Date of this Version

2012

Citation

PNAS August 21, 2012 vol. 109 no. 34 13787–13792

Abstract

Aberrant glucose metabolism is one of the hallmarks of cancer that facilitates cancer cell survival and proliferation. Here, we demonstrate that MUC1, a large, type I transmembrane protein that is overexpressed in several carcinomas including pancreatic adenocarcinoma, modulates cancer cell metabolism to facilitate growth properties of cancer cells. MUC1 occupies the promoter elements of multiple genes directly involved in glucose metabolism and regulates their expression. Furthermore, MUC1 expression enhances glycolytic activity in pancreatic cancer cells. We also demonstrate that MUC1 expression enhances in vivo glucose uptake and expression of genes involved in glucose uptake and metabolism in orthotopic implantation models of pancreatic cancer. The MUC1 cytoplasmic tail is known to activate multiple signaling pathways through its interactions with several transcription factors/coregulators at the promoter elements of various genes. Our results indicate that MUC1 acts as a modulator of the hypoxic response in pancreatic cancer cells by regulating the expression/stability and activity of hypoxia-inducible factor-1α (HIF-1α). MUC1 physically interacts with HIF-1α and p300 and stabilizes the former at the protein level. By using a ChIP assay, we demonstrate that MUC1 facilitates recruitment of HIF-1α and p300 on glycolytic gene promoters in a hypoxia-dependent manner. Also, by metabolomic studies, we demonstrate that MUC1 regulates multiple metabolite intermediates in the glucose and amino acid metabolic pathways. Thus, our studies indicate that MUC1 acts as a master regulator of the metabolic program and facilitates metabolic alterations in the hypoxic environments that help tumor cells survive and proliferate under such conditions.