Downregulation of PTEN/MMAC/TEP1 expression in human prostate cancer cell line DU145 by growth stimuli.
Genetic alterations and/or deletion of the tumor suppressor gene PTEN/MMAC/TEP1 occur in many types of human cancer including prostate cancer. We describe the production of monoclonal antibody against recombinant human PTEN and the study of PTEN gene and protein expression in three commercially available human prostate cancer cell lines, PC-3, LNCaP, and DU 145. Northern blotting analyses showed that LNCaP and DU145 but not PC-3 cells expressed PTEN mRNA. However, Western blotting analyses using a monoclonal antibody against PTEN demonstrated the expression of PTEN protein in DU145 but not LNCaP cells. In DU 145 cells, PTEN expression at both the mRNA and protein levels inversely correlated with serum concentrations and levels of PKB/Akt phosphorylation. In addition, the basal activity of PKB/Akt as indicated by level of phosphorylation was higher in prostate cancer cells which do not express PTEN than that in the cells expressing wild type PTEN. Thus, PTEN may play a critical role in regulating cellular signaling in prostate cancer cells.
Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha 68198-4525, USA.
Dhundy R
DR
Bastola
Gurcharan S
GS
Pahwa
Ming-Fong
MF
Lin
Pi-Wan
PW
Cheng
D000911:Antibodies, Monoclonal / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D018076:DNA, Complementary / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D008297:Male; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis* / Q000737:chemistry / Q000502:physiology*; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000502:physiology*
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human