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Regulation of a Family of Homeodomain Transcription Factor PAX mRNA Expression in PC‐3 Human Prostate Cancer Cells by Nutrient Limitation
Author(s) -
Zhang Zhiying,
Pan YuanXiang
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb42-d
Subject(s) - messenger rna , kinase , transcription factor , gene expression , northern blot , microbiology and biotechnology , biology , western blot , protein kinase a , mapk/erk pathway , gene , chemistry , biochemistry
Purpose: To examine the role of nutrient availability in regulating gene expression in PC‐3 cells, the expression patterns of transcription factors PAX under amino acid or glucose limitation were investigated. Materials and Methods: PC‐3 cells were incubated in MEM, or MEM free of amino acids or glucose for 0, 2, 4, 8, 12, 16 and 24 hours. Real‐time qRT‐PCR and western blot analysis were used to detect mRNA and protein expression. Results: Pax1/6/9 mRNA expression was demonstrated in PC‐3 whereas Pax2 was not detected in PC‐3 by qRT‐PCR. Deprivation of amino acids or glucose induced the expression of activating transcription factor ATF3 mRNA in PC‐3 cells, whereas Pax1/6/9 mRNA expression was reduced by both conditions, among which Pax9 exhibited the most significant down‐regulation. For Pax9, a 3 fold reduction of mRNA expression was observed from 0 to 8 hours, followed by an increased expression from 8 to 16 hours, indicating the temporal requirement of Pax9 expression in PC‐3 cells under nutrient limitation. Western blot showed the phosphorylation levels of kinases, MEK1/2 and ERK1/2, in the mitogen activated protein kinases (MAPK) pathway, increased in PC‐3 cells after amino acid deprivation for 2 to 8 hours, and then decreased after 8 hours, which correlated to the initial down‐regulation and the later recovering of Pax9 gene expression. Conclusions: These results suggest regulation of Pax gene expression is linked to MAPK pathway activation and may play an important role in the response of PC‐3 cells to the environmental changes.