title: NKX3.1 potentiates TNF-alpha/CHX-induced apoptosis of prostate cancer cells through increasing caspase-3 expression and its activity.
abstract: NKX3.1, a prostate-specific homeobox gene, plays an important role in prostate cancer and usually functions as tumor suppressor gene. Previously we have demonstrated that forced expression of NKX3.1 reduced cell growth and invasion in prostate cancer cell line PC-3. Presently, we investigated the effect of NKX3.1 on the sensitivity of the prostate cancer cells to apoptosis inducer tumor necrosis factor-alpha (TNF-alpha) and cycloheximide (CHX). PC-3 cells were transfected with NKX3.1 expression plasmid (pcDNA3.1-NKX3.1) and LNCaP cells were transfected with siRNA expression plasmid (pRNAT-RNAi1) targeting NKX3.1. The cell morphology and apoptotic rate were analyzed by Hoechst 33342 staining and Flow Cytometry in absence or presence of TNF-alpha and CHX. The activity of caspase-3 was determined using DEVD-pNA as substrate. Simultaneously, the effect of NKX3.1 on caspase-3 expression was detected using RT-PCR and Western blot. The results showed that ectopic expression of NKX3.1 promoted TNF-alpha/CHX-induced apoptosis in PC-3 cells, whereas knockdown of NKX3.1 protected LNCaP cells from apoptosis induced by TNF-alpha/CHX. The pro-apoptosis activity of NKX3.1 might partially contribute to its elevation of caspase-3 expression and activity. Manipulating NKX3.1 expression should be a promising therapeutic strategy for treating both androgen-dependent and androgen-independent prostate cancer.
authors.affiliation: Institution of Biochemistry and Molecular Biology, Medical School of Shandong University, Jinan 250012, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Pengju
authors.forename: Chen
authors.initials: C
authors.lastname: Weiwen
authors.forename: Wang
authors.initials: W
authors.lastname: Aiying
authors.forename: Chen
authors.initials: C
authors.lastname: Zhaobo
authors.forename: Ni
authors.initials: N
authors.lastname: Nana
authors.forename: Huang
authors.initials: H
authors.lastname: Zhaoqin
authors.forename: Liu
authors.initials: L
authors.lastname: Qingwei
authors.forename: Jiang
authors.initials: J
authors.lastname: Anli
mesh_terms: D017209:Apoptosis; D053148:Caspase 3 / Q000096:biosynthesis* / Q000235:genetics; D045744:Cell Line, Tumor; D003513:Cycloheximide / Q000494:pharmacology*; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D018398:Homeodomain Proteins; C491178:NKX3-1 protein, human; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; D053148:Caspase 3