title: Prostate specific membrane antigen knockdown impairs the tumorigenicity of LNCaP prostate cancer cells by inhibiting the phosphatidylinositol 3-kinase/Akt signaling pathway.
abstract: BACKGROUND
  Prostate specific membrane antigen (PSMA) can facilitate the growth, migration, and invasion of the LNCaP prostate cancer cell lines, but the underlying molecular mechanisms have not yet been clearly defined. Here, we investigated whether PSMA serves as a novel regulator of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling by employing PSMA knockdown model and PI3K pharmacological inhibitor (LY294002) in LNCaP prostate cancer cells.
  
  
  METHODS
  PSMA knockdown had been stably established by transfecting with lentivirus-mediated siRNA in our previous study. Then, LNCaP cells were divided into interference, non-interference, and blank groups. We first testified the efficacy of PSMA knockdown in our LNCaP cell line. Then, we compared the expression of PSMA and total/activated Akt by Western blotting in the above three groups with or without LY294002 treatment. Furthermore, immunocytochemistry was performed to confirm the changes of activated Akt (p-Akt, Ser473) in groups. Besides, cell proliferation, migration, and cell cycle were measured by CCK-8 assay, Transwell analysis, and Flow cytometry respectively.
  
  
  RESULTS
  After PSMA knockdown, the level of p-Akt (Ser473) but not of total-Akt (Akt1/2) was significantly decreased when compared with the non-interference and blank groups. However, LY294002 administration significantly reduced the expression of p-Akt (Ser473) in all the three groups. The results of immunocytochemistry further confirmed that PSMA knockdown or LY294002 treatment was associated with p-Akt (Ser473) down-regulation. Decrease of cell proliferation, migration, and survival were also observed upon PSMA knockdown and LY294002 treatment.
  
  
  CONCLUSIONS
  Taken together, our results reveal that PI3K/Akt signaling pathway inhibition may serve as a novel molecular mechanism in LNCaP prostate cancer cells of PSMA knockdown and suggest that Akt (Ser473) may play a critical role as a downstream signaling target effector of PSMA in this cellular model.
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Zhenghui
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Prenatal Diagnosis Center, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Du
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Jieqing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Liangkuan
authors.initials: L
authors.lastname: Bi
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Tianxin
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Urology, General Hospital of Guangzhou Military Command of People's Liberation Army, Guangzhou, Guangdong 510000, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Kewei
authors.initials: K
authors.lastname: Xu
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Jinli
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yatsen University, Guangzhou, Guangdong 510120, China. Email: huanghai257@126.com.
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
mesh_terms: D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D043425:Glutamate Carboxypeptidase II / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000628:therapy*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D034622:RNA Interference; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
chemical_list: D000954:Antigens, Surface; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II