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Objective To analyze the correlation between P73 gene G4C14-to-A4T14 double nucleotide polymorphism and the risk of lung cancer in Guangdong population. Methods Genotype analysis of P73 gene polymorphism in peripheral blood of 642 patients with lung cancers (including 450 NSCLC patients and 192 SCLC patients) and 354 normal controls was performed with HRM method (high-resolution fusion curve). Results HRM genotyping results showed that the distribution of P73 genotypes in 450 NSCLC patients was as follows: GC/GC 280 (62.3%), GC/AT 155 (34.4%), and AT/AT 15 (3.3%). P73 genotypes in 192 SCLC patients were 118 GC/GC (61.5%), 67 GC/AT (34.9%) and 7 AT/AT (3.6%). The P73 genotypes of 354 normal controls were 192 GC/GC (53.1%), 136 GC/AT (38.5%), and 26 AT/AT (8.4%). AT/AT homozygous genotypes significantly reduced the risk of NSCLC (OR=0.393；95% CI:0.037-0.873；P=0.001) and SCLC (OR=0.428；95%CI:0.050-0.880；P<0.001) compared with non-carriers. Conclusion The results of the present study indicated that the polymorphism of P73 G4C14-A4T14 may be a modification factor for the susceptibility of lung cancer in Guangdong province, and the increased GC content in the P73 gene may increase the risk of lung cancer.
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Objective To analyze the correlation between polymorphisms at position 4 and 14 in exon 2 of the p73 gene and susceptibility to human papillomavirus (HPV) infection.Methods Tissue specimens were obtained from the lesions of 83 patients with condyloma acuminatum and 11 patients with bowenoid papulosis,and blood samples from all the patients as well as 150 health checkup examinees with high risk for sexually transmitted diseases (STDs) at STD clinics (negative control group).PCR was performed to detect HPV DNA in lesional tissue specimens,followed by direct sequencing and nucleotide alignment using the BLAST program for the determination of HPV genotypes.To assess polymorphisms at position 4 and 14 in exon 2 of the p73 gene,DNA was extracted from all the blood samples,and the p73 gene was amplified by PCR with the primer shP73 followed by gene sequencing.The association between the polymorphisms and susceptibility to HPV infection was analyzed.Results Of the 83 tissue specimens from patients with condyloma acuminatum,42.2％ (35/83) were positive for HPV 6,and 41.0％ (34/83) for HPV 11.Among the 11 tisssue specimens from bowenoid papulosis lesions,5 were positive for HPV 16,and 3 for HPV 6.The p73 gene was successfully amplified and sequenced from all the patients with condyloma acuminatum or bowenoid papulosis as well as from 132 out of 150 health checkup examinees.There were three genotypes at position 4 and 14 in exon 2 of the p73 gene,including A4T14/G4C14,A4T14/A4T14,G4C14/G4C14,of which,A4T14/A4T14 was associated with a higher risk for condyloma acuminatum (OR 4.89,95％ CI 1.50-15.91) as well as bowenoid papulosis (OR 7.11,95％ CI 1.144-44.20),and G4C14/G4C14 with a lower risk for bowenoid papulosis (OR 0.16,95％ CI0.04-0.65),in patients with HPV infection.Conclusions The A4T14 allele in exon 2 of the p73 gene increases the risk for bowenoid papulosis and condyloma acuminatum,but no significant correlation is found between the susceptibility to high-or low-risk HPV infection and polymorphisms at the two positions in the p73 gene.
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Objective To study the effect of triptolide (TP) on the proliferation of breast carcinoma cell line MCF-7 and its association with P53/P73 gene expression and methylation. Methods MCF-7 cells were treated with different concentrations of TP (10 ng/ml, 20 ng/ml, and 40 ng/ml), and the proliferation of MCF-7 cells was measured by MTT method. The expressions of methyltransferase DNMT1, DNMT3a and DNMT3b mRNA were measured by RT-PCR in MCF-7 cells, P53/P73 gene methylation was analyzed by methylation specific PCR, and the protein expression of p53/P73 in MCF-7 cells was examined by Western blotting assay. Results TP inhibited the proliferation of MCF-7 cells in a dose-dependent manner (P< 0. 05, P<0. 01), with the inhibitory rate being (70. 1 ± 3. 52)% at 40 ng/ml TP, and the IC50 of TP was 20 ng/ml. TP significantly inhibited DNMT1, DNMT3a, and DNMT3b mRNA expression in MCF-7 cells (P<0. 05, P<0. 01), and it also significantly inhibited methylation of P53 promoter region. TP increased P53 gene expression at 20 ng/ml and the increase was significant at 40 ng/ml (P<0. 01). TP reversed the hypermethylation of P73 gene in MCF-7 cells; it also significantly increased P73 mRNA expression at 10 ng/ml (P<0. 05), and the increase was in a dose-dependent manner. Western blotting analysis showed that TP (20 ng/ml) increased the protein expression of P53 and P73 in MCF-7 cells. Conclusion TP can promote the expression of P53 and P73 genes through inhibiting methyltransferase-dependent gene methylation, and further inhibit the proliferation of MCF-7 cells.
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Objective To investigate the relationship between the expression of p63, p73 proteins and the development of hemangioma. Methods The immunohistochemical technique and quantitative image analysis were used to detect the expression of p63 and p73 proteins in 40 cases of capillary hemangioma and 20 specimens of normal skin. Results The absorbance value (mean ? SD) of p63 and p73 expression in normal skin tissue, proliferative phase of hemangioma and involuting phase of hemangioma were 0.923 ? 0.191 and 0.953 ? 0.120, 8.271 ? 1.953 and 6.408 ? 2.151, 0.920 ? 0.187 and 1.073 ? 0.516, respectively. The expression of p63 and p73 in proliferative phase of hemangioma was significantly increased as compared with those in involuting phase of hemangioma and normal skin tissue (P 0.05). Conclusions It is suggested that p63 gene is not a tumor suppressor gene but an oncogene in hemangioma and may contribute to the proliferation of endothelial cell and be associated with angiogenesis, and p73 may play an important role in the proliferation of hemangioma.