Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
【Abstract】Objective To investigate whether SUMO-1 enhances the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells. Methods The HepG2 cells were transfected respectively or simultaneouly with the following expressional plasmids as pcDNA3-wtp53（pwtp53，including human wild-type p53 gene），pCMV-HDM1B（pMDM2，including HDM2 gene， homologous gene as murine double minute gene 2），pcDNA3-His6-SUMO-1（pSUMO-1 ，including small ubiquitin-like modifier1 gene）and plasmid pcDNA3.The proteins expressed in cells were detected by means of Western blotting and the apoptosis rates of cells were measured by flow cytometry. Results The protein bands of p53 and MDM2 could be seen in cells transfected with pwtp53 and pMDM2. Meanwhile，the relative larger molecular weight bands were also seen in cells transfected with pSUMO-1 which represented the p53 and MDM2 protein modification by SUMO-1. Merely the trace of p53 protein was detected in cells not transfected with any plasmid or only transfected with empty plasmid and pSUMO-1. In cells transfected with pwtp53 and pwtp53+pSUMO-1，the apoptosis rates were (16.79±1.62)%and (18.15±1.36)%. When transfected with pwtp53+pMDM2，the rate decreased to (5.17±1.23)%. The apoptosis rate would come up again to (14.06±1.84)% after transfected with pwtp53+pMDM2+pSUMO-1 and the difference of rates were significant compared to the cells transfected with pwtp53+pMDM2 (PH＜0.01）. The apoptosis rates in other cells were less than 2% and had no significant difference. Conclusion SUMO-1 could increase the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells through combining to p53 protein or its post-translational modification and inhibiting p53 degradation by MDM2.
Objective To explore the progress of the relationship between the tumor suppressor gene p53 and oncogene c-erbB-2 and gastric cancer in recent years. Methods Relevant literatures about p53 and c-erbB-2 in gastric cancer were collected and analyzed. Results The mutation of p53 gene and the over-expression of c-erbB-2 gene were a common event in gastric cancer. The mutation of p53 gene was correlated with the location of gastric cancer and its aggressive biological behavior. The over-expression of c-erbB-2 gene could be used as an independent prognostic parameter in gastric cancer. The drugs targeted on p53 and c-erbB-2 gene were being developed. Conclusion Further research on the role of p53 and c-erbB-2 gene in the development of gastric cancer is helpful to understand the biological behavior and provide theoretical basis for gene therapy.
Objective To explore the effect of exogenous estrogen receptor β1 (ERβ1) gene on the expression of p53 as well as the changes of apoptosis in MDA-MB-231 cell line and to investigate the biological role of ERβ1 in breast cancer. Methods Recombinant eukaryotic expressing vector containing ERβ1 cDNA was transfected into human breast cancer cell MDA-MB-231 by using cationic liposome LipofectamineTM 2000. The expression levels of p53 and ERβ1 in mRNA and protein were evaluated by real-time PCR and Western blot, respectively. Cell growth curve was used to detect the changes of cell proliferation ability. Cell apoptosis was detected by flow cytometry. Results After transfected with vector containing ERβ1 cDNA, proliferation ability of MDA-MB-231 cell decreased and the expression levels of both ERβ1 and p53 in both mRNA and protein increased (Plt;0.01). Rate of cell apoptosis increased in ERβ1 upregulation groups （Plt;0.01）. Conclusion ERβ1 can induce apoptosis and inhibit the growth of MDA-MB-231 cells by upregulating p53 expression.
Objective To investigate the possible interaction between the ras and p53 genes overexpression in thyroid carcinoma, and whether there is correlation between the ras and p53 overexpression and clinico-pathological criteria. Methods Thyroid lesions from eighty patients were examined for expression of ras and p53 genes by the LSAB immunohistochemistic method. Of these patients, 54 were diagnosed as malignant lesions and 26 benign nodular thyroid disorders. Results The positive immunostain rate for ras and p53 genes was 90.7%, 23.0% and 55.5%, 30.7% in carcinoma and benign lesions respectively with statistically significance between thyroid carcinomas and benign disorders (Ｐ＜0.05). Both ras and p53 overexpressions coexisted in 30 thyroid carcinomas and follow-up showed that 3 of them died and 5 of them had recurrence within 4 years.Conclusion Activation of ras gene and inactivation of p53 gene are cooperatively associated in thyroid tumorigenesis. The concurrent overexpression of ras and p53 could result in a poor prognosis.
ObjectiveTo explore the expressions of survivin, p53, and Ki67 in recurrence or metastasis breast cancer tissue, and explore their correlations and clinical significance. MethodsEighty-six patients with the chest wall local recurrence, axillary or supraclavicular lymph node metastases get treated in this hospital between January 2005 and January 2010 were excised and the expressions of survivin, p53, and Ki67 were detected by immunohistochemistry test, then compared them between the recurrence and metastasis breast cancer tissues and the primary breast cancer tissues. ResultsThe positive expression rate of survivin, p53, and Ki67 in the recurrence and metastasis breast cancer tissues were significantly higher than those in the primary breast cancer tissues, survivin: 90.70% (78/86) versus 61.63% (53/86), χ2=20.014 895, Plt;0.001; p53: 68.60% (59/86) versus 52.33% (45/86), χ2=4.766 968, Plt;0.05; Ki67: 62.79% (54/86) versus 46.51% (40/86), χ2=4.597 927，Plt;0.05. The positive expression rates of survivin in the recurrence and metastasis patients with p53, Ki67 negative expression were significantly higher than those of the primary breast cancer tissue (70.37% versus 24.39%, χ2=14.071 113, Plt;0.05; 75.00% versus 39.13%, χ2=6.540 373, Plt;0.05). The correlation coefficient of survivin with p53 and Ki67 positive expressions in the recurrence and metastasis breast cancer tissue and the primary breast cancer tissue were 0.876 214, 0.773 643 and 0.725 164, 0.698 112, respectively, Plt;0.05. ConclusionThe positive expression rates of survivin, p53, and Ki67 which increase in recurrence and metastasis breast cancer tissue indicate bad prognosis.
Objective To explore the expression of survivin gene in retinoblastoma (RB) and its relationship with the stages and histodifferentiation degree of RB and the expression of p53、bcl-2 proteins. Methods Expression of survivin, p53 and bcl-2 proteins in 38 RB conventional paraffin samples were detected with survivin, p53 and bcl-2 monoclonal antibodies respectively by immunohistochemical assay. The expression of survivin of normal retina in 6 control samples was observed. Results In 38 cases of RB, positive expression of survivin was found in 20 (52.6%); while none of the 6 normal retinal tissue expressed survivin, which had significant difference between the two group (P＜0.05). The positive expression of survivin did not correlate with sex of patient, disease stages and histological type (P＞0.05). In 38 RB cases, positive expression of p53 was in 25 with the rate of 65.8%, and of bcl-2 in 18 with the rate of 47.4%. The positive-expressed rates were much higher in positive-expressed p53 and bcl-2 group than those in the negative-expressed p53 and bcl-2 group(P＜0.05). Conclusion The increase of the expression of survivin implies that it may take part in the occurrence and development of RB; the interaction among survivin, p53 and bcl-2 may participate in the access and the course of RB. (Chin J Ocul Fundus Dis，2004，20：215-217)
ObjectiveTo explore the relationship between p53 mutation in 5-8 exons and type of epithelial ovarian cancer (EOC) pathogenesis of Han nationality women.
MethodsFrom August 2011 to December 2012, 45 patients with primary EOC (Han nationality women from Sichuan Province) diagnosed surgically and pathologically were selected. Using direct DNA sequencing, we analyzed the mutations of p53 in 5-8 exons of all cases, and the EOC patients were divided into two types according dualism and the pathogenesis results. The p53 mutation of the different types in EOC patients were analyzed.
ResultsThe frequency and efficiency of p53 mutation in type-ⅡEOC patients were significantly higher than that in typeⅠ(P < 0.01). And the codon 175 might be a mutational hotspot of type-ⅡEOC. The malignant degree and oviduct involved frequency of type-ⅡEOC were obviously higher than that of type-I EOC; p53 mutation frequency in high malignant patients increased significantly.
Conclusionsp53 mutation plays an important role in the development of type-ⅡEOC. The codon 175 might be a mutational hotspot of type-ⅡEOC.
Objective To investigate the relationship of p53 codon 72 polymorphism and susceptibility to gastric cancer in high incidence area of Hexi area of Gansu province. Methods The Arg/Pro polymorphism of p53 gene was detected by real-time PCR in 140 patients with gastric cancer, 110 patients with gastric precancerous lesion and 125 healthy controls; Helicobacter pylori (Hp) infection was detected by Warthin-Starry silver method． Results The Pro allele frequencies of p53 gene in gastric cancer cases (0.543) were higher than those in gastric precancerous lesion (0.482) and controls (0.472). The Pro genotype had a more than 1.846 fold increased risk of gastric cancer 〔OR=1.846; 95% 〗CI (1.006-3.387); P =0.046〕． With statistical analysis， the genotype of p53 gene was correlated with location and Laurens histological type （ P ＜ 0.05）. A significantly higher risk of gastric cancer was also seen in cases with p53 Pro genotype, food, Hp infection, positive mind factor and positive family history． Conclusion There is a b correlation between the p53 gene codon 72 Arg/Pro polymophism and susceptibility to gastric cancer in Hexi area of Gansu province and the Pro/Pro genotype may be one of the major risk factors in patients with gastric cancer.
Objective To study the association and the effect of the expression of p16 and p53 protein on the occurence and development of gallbladder carcinoma. Methods The expression of p16 and p53 protein were detected in 40 cases of gallbladder carcinoma with immunohistochemical method. Results The expressions of p16 and p53 protein were closely correlated to the tumor pathological grade, lymph mode metastasis and prognosis. p16 protein was correlated to the Nevin classifications. Conclusion The results indicate that the low expression rate of p16 protein occurred in the advanced stage of gallbladder carcinoma. The expression of p16 and p53 protein are helpful in judging the malignant degree and prognosis of primary gallbladder cancer.
