Lemur Tyrosine Kinase 2, a novel target in prostate cancer therapy
ONCOTARGET
Authors: Shah, Kalpit; Bradbury, Neil A.
Abstract
Progression from early forms of prostate cancer to castration-resistant disease is associated with an increase in signal transduction activity. The majority of castration-resistance cancers persist in the expression of the androgen receptor (AR), as well as androgen-dependent genes. The AR is regulated not only by it associated steroid hormone, but also by manifold regulatory and signaling molecules, including several kinases. We undertook evaluation of the role of Lemur Tyrosine Kinase 2 (LMTK2) in modulating AR activity, as several Genome Wide Association Studies (GWAS) have shown a marked association of LMTK2 activity with the development of prostate cancer. We confirm that not only is LMTK2 mRNA reduced in prostate cancer tissue, but also LMTK2 protein levels are markedly diminished. Knockdown of LMTK2 protein in prostate cell lines greatly increased the transcription of androgen-responsive genes. In addition, LMTK2 knockdown led to an increase in prostate cancer stem cell populations in LNCaP cells, indicative of increased tumorogenicity. Using multiple approaches, we also demonstrate that LMTK2 interacts with the AR, thus putting LMTK2 as a component of a signaling complex modulating AR activity. Our finding that LMTK2 is a negative regulator of AR activity defines a novel cellular pathway for activation of AR-responsive genes in castrate resistant-prostate cancer. Moreover, pharmacologic manipulation of LMTK2 activity will provide a novel therapeutic target for more effective treatments for patients with castrate-resistant prostate cancer.
Multiple newly identified loci associated with prostate cancer susceptibility
NATURE GENETICS
Authors: Eeles, Rosalind A.; Kote-Jarai, Zsofia; Giles, Graham G.; Al Olama, Ali Amin; Guy, Michelle; Jugurnauth, Sarah K.; Mulholland, Shani; Leongamornlert, Daniel A.; Edwards, Stephen M.; Morrison, Jonathan; Field, Helen I.; Southey, Melissa C.; Severi, Gianluca; Donovan, Jenny L.; Hamdy, Freddie C.; Dearnaley, David P.; Muir, Kenneth R.; Smith, Charmaine; Bagnato, Melisa; Ardern-Jones, Audrey T.; Hall, Amanda L.; O'Brien, Lynne T.; Gehr-Swain, Beatrice N.; Wilkinson, Rosemary A.; Cox, Angie; Lewis, Sarah; Brown, Paul M.; Jhavar, Sameer G.; Tymrakiewicz, Malgorzata; Lophatananon, Artitaya; Bryant, Sarah L.; Horwich, Alan; Huddart, Robert A.; Khoo, Vincent S.; Parker, Christopher C.; Woodhouse, Christopher J.; Thompson, Alan; Christmas, Tim; Ogden, Chris; Fisher, Cyril; Jamieson, Charles; Cooper, Colin S.; English, Dallas R.; Hopper, John L.; Neal, David E.; Easton, Douglas F.
Abstract
Prostate cancer is the most common cancer affecting males in developed countries. It shows consistent evidence of familial aggregation, but the causes of this aggregation are mostly unknown. To identify common alleles associated with prostate cancer risk, we conducted a genome-wide association study (GWAS) using blood DNA samples from 1,854 individuals with clinically detected prostate cancer diagnosed at <= 60 years or with a family history of disease, and 1,894 population-screened controls with a low prostate-specific antigen (PSA) concentration (< 0.5 ng/ml). We analyzed these samples for 541,129 SNPs using the Illumina Infinium platform. Initial putative associations were confirmed using a further 3,268 cases and 3,366 controls. We identified seven loci associated with prostate cancer on chromosomes 3, 6, 7, 10, 11, 19 and X (P = 2.7 x 10(-8) to P = 8.7 x 10(-29)). We confirmed previous reports of common loci associated with prostate cancer at 8q24 and 17q. Moreover, we found that three of the newly identified loci contain candidate susceptibility genes: MSMB, LMTK2 and KLK3.