title: A role for the G12 family of heterotrimeric G proteins in prostate cancer invasion.
abstract: Many studies have suggested a role for the members of the G12 family of heterotrimeric G proteins (Galpha12 and Galpha13) in oncogenesis and tumor cell growth. However, few studies have examined G12 signaling in actual human cancers. In this study, we examined the role of G12 signaling in prostate cancer. We found that expression of the G12 proteins is significantly elevated in prostate cancer. Interestingly, expression of the activated forms of Galpha12 or Galpha13 in the PC3 and DU145 prostate cancer cell lines did not promote cancer cell growth. Instead, expression of the activated forms of Galpha12 or Galpha13 in these cell lines induced cell invasion through the activation of the RhoA family of G proteins. Furthermore, inhibition of G12 signaling by expression of the RGS domain of the p115-Rho-specific guanine nucleotide exchange factor (p115-RGS) in the PC3 and DU145 cell lines did not reduce cancer cell growth. However, inhibition of G12 signaling with p115-RGS in these cell lines blocked thrombin- and thromboxane A2-stimulated cell invasion. These observations identify the G12 family proteins as important regulators of prostate cancer invasion and suggest that these proteins may be targeted to limit invasion- and metastasis-induced prostate cancer patient mortality.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kelly
authors.forename: Laura N
authors.initials: LN
authors.lastname: Stemmle
authors.forename: John F
authors.initials: JF
authors.lastname: Madden
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Fields
authors.forename: Yehia
authors.initials: Y
authors.lastname: Daaka
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Casey
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D044365:GTP-Binding Protein alpha Subunits, G12-G13 / Q000235:genetics / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness; D011467:Prostate / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology; D011897:Random Allocation; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D064067:Rho Guanine Nucleotide Exchange Factors; D015290:Second Messenger Systems / Q000502:physiology*
chemical_list: D015820:Cadherins; D020662:Guanine Nucleotide Exchange Factors; D043562:Receptors, G-Protein-Coupled; D011993:Recombinant Fusion Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; D044365:GTP-Binding Protein alpha Subunits, G12-G13