Identification of Estrogen-responsive Genes in p53+/- Knockout and Isogenic Wild-type Parent Strain Mice by CDNA Macroarray Analysis
Mohd. Nazil Salleh,
Yun Hin Taufiq-Yap
To identify putative genetic targets for p53 in vivo, in this research applied the cDNA macroarray gene expression profiles associated with apoptosis by comparing p53+/- knockout mice and wild-type mice on the uterus of female mice. p53+/- knockout mice and wild-type mice were treatedwith DES (500 μmole kg-1) or vehicle i.p once daily for 4 days. Total RNAs were obtained from uterus of control and DES-treated. The signal intensities of individual gene spots on the membrane were quantified and normalised to the expression level of the GAPDH gene as an internal control. Present results demonstrated that sixteen genes; bad, bax, bcl-2, bcl-w, bcl-x, caspase-3, caspase-7, caspase-8, c-myc, E124, GADD45, mdm2, NKκb1, p53, p21, Rb and trail were up-regulated and six genes; caspase-1, caspase-2, DR5, E2F1, FasL and iNOS did not changed in response to DES treatment in wild-type mice compared to p53+/- knockout mice. Most genes are involved in cell cycle regulation, signal transduction, apoptosis, or transcription. The greatest changes were seen in bad, bcl-x, mdm2, p53 and p21 gene expression in wild-type mice compared to p53+/- knockout mice. In comparing p53 and p21 gene expression in wild-type mice and p53+/- knockout mice, there was a 2.1-fold versus 8.3-fold; 16-fold versus 5.5-fold an increment in induction, respectively. RT-PCR was used to confirm the biggest changes of p21, p53 and bax genes. Using this approach, present study identified apoptosis associated genes regulated in response to DES and have revealed putative differences between the isogenic parent strain and p53+/- knockout mice, which will contribute to a better understanding of toxicity/carcinogenicity mechanisms in this model.
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