MTH1 expression is required for effective transformation by oncogenic HRAS

Autor: Priyamvada Rai, Anisleidys Munoz, Maria G. Giribaldi, Asmita Patel, Katherine Halvorsen
Rok vydání: 2014
Předmět:
Zdroj: Oncotarget
ISSN: 1949-2553
Popis: // Maria G. Giribaldi 1, 2 , Anisleidys Munoz 1 , Katherine Halvorsen 1, 3 , Asmita Patel 1, 4 , Priyamvada Rai 1, 5 1 Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA 2 University of California, San Diego, CA, USA 3 OPKA-CURNA, Miami, FL, USA 4 Beckman-Coulter Lifesciences, Indianapolis, IN, USA 5 Sylvester Comprehensive Cancer Center, University of Miami, FL, USA Correspondence to: Priyamvada Rai, e-mail: prai@med.miami.edu Keywords: MTH1, oncogenic RAS, transformation, EMT, glycolysis Received: July 22, 2014 Accepted: February 24, 2015 Published: March 19, 2015 ABSTRACT Due to sustaining elevated reactive oxygen species (ROS), oncogenic RAS-transformed cells upregulate redox-protective genes, among them the mammalian 8-oxodGTPase, MutT Homolog 1 (MTH1). We previously showed MTH1 abrogates RAS oncogene-induced senescence (OIS) in normal cells and that its inhibition compromises the tumorigenicity of established oncogenic RAS-harboring cancer cells. Here, we investigated how pre-transformation MTH1 levels in immortalized cells influence HRASV12-induced oncogenic transformation. We find MTH1 suppression prior to HRASV12 transduction into BEAS2B immortalized epithelial cells compromised maintenance of high RASV12- and oncogenic ROS-expressing cell populations. Furthermore, pre-transformation MTH1 levels modulated the efficiency of HRASV12-mediated soft agar colony formation. Downstream transformation-associated traits such as the epithelial-mesenchymal transition (EMT) were also compromised by MTH1 inhibition. These collective effects were observed to a greater degree in cells harboring high vs. low RASV12 levels, suggesting MTH1 is required for tumor cells to accumulate RAS oncoprotein. This is significant as, a priori , one cannot ascertain whether tumor-promoting adaptations wrought by introducing oncogenic RAS into an immortalized cell are capable of overcoming pre-transformation deficiencies. Our results suggest nucleotide pool sanitization comprises an important transformation-promoting requirement that, if compromised, cannot be adequately compensated post-transformation and thus is likely to affect optimal development and progression of RAS-driven tumors.
Databáze: OpenAIRE