An oncogenic KRAS transcription program activates the RHOGEF ARHGEF2 to mediate transformed phenotypes in pancreatic cancer.
Activating mutations of KRAS are nearly ubiquitous in pancreatic adenocarcinomas occurring in greater than 90% of cases. Cellular transformation by oncogenic RAS requires the RHO guanine exchange factor ARHGEF2 (also known as GEF-H1) for tumor growth and survival. Here, we find oncogenic KRAS activates ARHGEF2 through a minimal RAS responsive promoter. We have determined the endogenous ARHGEF2 promoter is positively regulated by the transcription factors ELK1, ETS1, SP1 and SP3 and negatively regulated by the RAS responsive element binding protein (RREB1). We find that the panel of ARHGEF2-regulating transcription factors modulates RAS transformed phenotypes including cellular viability, anchorage-independent growth and invasion-migration of pancreatic cancer cells. RREB1 knockdown activates the amplitude and duration of RHOA via increased ARHGEF2 expression. By relieving the negative regulation of RREB1 on the ARHGEF2 promoter, we determined that ETS1 and SP3 are essential for the normal expression of ARHGEF2 and contribute to the migratory behavior of pancreatic cancer cells. Furthermore, enforced expression of ARHGEF2 rescues loss of SP3 driven invasion-migration and anchorage-independent growth defective phenotypes through restored activation of RHOA. Collectively, our results identify a transcription factor program required for RAS transformation and provide mechanistic insight into the highly metastatic behavior of pancreatic cancer.
Princess Margaret Cancer Centre, University Health Network, Toronto Medical Discovery Tower, University of Toronto, Toronto, Canada.
Oliver A
OA
Kent
Princess Margaret Cancer Centre, University Health Network, Toronto Medical Discovery Tower, University of Toronto, Toronto, Canada.
María-José
MJ
Sandí
Princess Margaret Cancer Centre, University Health Network, Toronto Medical Discovery Tower, University of Toronto, Toronto, Canada.
Helen E
HE
Burston
Donnelly Centre and Banting and Best Department of Medical Research, University of Toronto, Toronto, Canada.
Kevin R
KR
Brown
Princess Margaret Cancer Centre, University Health Network, Toronto Medical Discovery Tower, University of Toronto, Toronto, Canada.|Department of Medicine, St. Michael's Hospital, Toronto, Canada.|Department of Medical Biophysics, St. Michael's Hospital, Toronto, Canada.|Department of Immunology, St. Michael's Hospital, Toronto, Canada.|Division of Rheumatology, St. Michael's Hospital, Toronto, Canada.
Robert
R
Rottapel
D045744:Cell Line, Tumor; D002465:Cell Movement; D002470:Cell Survival; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011401:Promoter Regions, Genetic; D050784:Proto-Oncogene Protein c-ets-1 / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics* / Q000378:metabolism; D064067:Rho Guanine Nucleotide Exchange Factors / Q000235:genetics*; D015398:Signal Transduction; D051705:Sp3 Transcription Factor / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation
C577356:ARHGEF2 protein, human; D004268:DNA-Binding Proteins; C494041:ETS1 protein, human; C117307:KRAS protein, human; D050784:Proto-Oncogene Protein c-ets-1; C101743:RREB1 protein, human; D064067:Rho Guanine Nucleotide Exchange Factors; C497121:SP3 protein, human; D014157:Transcription Factors; D051705:Sp3 Transcription Factor; D016283:Proto-Oncogene Proteins p21(ras)
ARHGEF2; GEFH1; KRAS; pancreatic; transcription