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)
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.
ObjectiveTo observe the expression and mechanism of hypoxia-inducible factor-1α (HIF-1α) and p53 protein at the altitude of 5000 meter plateau hypoxia environment in rats, as well as the effect of Astragalus injection. MethodsSixty Sprague Dawley rats were randomly divided into the Astragalus injection intervention group and normal saline control group, 30 rats in each group. Astragalus injection group rats were intraperitoneal injected of Astragalus injection (15 ml/kg) before 30 minutes into the plateau environment simulation cabin, normal saline group rats were intraperitoneal injected with the same volume of saline. 30 minutes after injection, rats in each group were reared in the plateau experiment cabin which simulated altitude of 5000 m (oxygen partial pressure 11.3 kPa) for 2, 6, 8, 12, 24 hours, each time period of 6 rats. When get out, the rats were executed immediately and eyes were harvested. Retinal sections were studied by hematoxylin eosin stain, and immunohistochemical method for HIF-1α and p53 expression. ResultsFor control rats, after 2 hours in the cabin, there was edema in retinal layers. HIF-1α and p53 were expressed mainly in the cytoplasm of retinal layers. When the periods in cabin extended, there was atrophy of retinal nerve fiber layer, swelling and degeneration of ganglion cells. The expression of HIF-1α and p53 was increased. Compared with the control group, the intervention group rat had similar but less severe retinal changes, and the expression of HIF-1α and p53 was significantly decreased (P<0.05). ConclusionAstragalus injection can reduce pathological retinal damage in rats at high altitude environment, and its mechanism may be associated with reduced HIF-1α, p53 expression.
Objective To understand the molecular mechanism of HBx in the carcinogenesis of hepatitis B virus (HBV) related hepatocellular carcinoma (HCC).Methods The literatures published in the past 5 years which are mainly about HBx and hepatocellular carcinoma were reviewed. Results HBx had many functions, such as cell malignant transformation, inhibiting DNA repair, trans-activation, inhibiting p53 and apoptosis. These functions together with its Fas/Fas-L interfering and caspase-3 inhibiting could contribute to the carcinogenesis and development of HBV relatde HCC. Conclusion HBx has broad spectrum of biological functions, which contribute to the carcinogenesis and development of HBV related HCC.
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.
【Abstract】Objective To investigate the expression of inducible nitric oxide synthase (iNOS) and p53 protein in hepatocellular carcinoma (HCC) and their relationship with angiogenesis. Methods Immunohistochemical method and image analysis technique were used to detect the expression of iNOS and p53 protein in tumor tissue sections of 59 HCC patients. Microvessel density (MVD) was counted by immunohistochemical staining with anti-CD34 antibody.Results ①The expression rates of iNOS and p53 were 81.4%(48/59), 64.4%(38/59) in HCC patients, respectively. The expression intensities of iNOS and p53 were 5 635±1 287, 3 352±873 in HCC patients, respectively. ②MVD was 32.5±2.73 in the tumor tissue of HCC patients. ③The expression of iNOS was correlated with the expression of p53 and MVD in HCC patients (P＜0.05); The expression of p53 was also correlated with the MVD in HCC patients (P＜0.05). Conclusion iNOS and p53 are highly expressed in HCC and may play a key role in angiogenesis of HCC.
Objective To clarify the correlation of p53 codon 72 polymorphism in peripheral blood with keloid susceptibility in Chinese population. Methods All the literatures of case-control research on the correlation between p53 codon 72 polymorphism in peripheral blood and keloid in Chinese population were searched in PubMed, EBSCO, CNKI, CBM, and WanFang Data from their establishment to August 2010. Meta-analyses were performed to detect whether there were differences between the keloid group and the control group about the distribution of genotypes of p53 codon 72 in peripheral blood, such as, Pro/Pro vs. Arg/Arg, Pro/Pro vs. Pro/Arg, and alleles Pro vs. Arg. Results Five studies involving 328 keloid patients and 420 patients in the control group were included. The results of meta-analyses showed that the population having the genotype Pro/Pro presented no increased keloid risk compared to that with the genotypes Arg/Arg (OR=2.17, 95%CI 0.86 to 5.47) or Pro/Arg (OR=1.90, 95%CI 0.92 to 3.93), while the allele Pro showed significant association with increased keloid risk compared to the allele Arg (OR=1.86, 95%CI 1.03 to 3.35). Conclusion The allele Pro of p53 codon 72 in peripheral blood of Chinese population is significantly associated with increased keloid risk.
【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 study the effect of 5-fluorouracil (5-FU) induced apoptosis of the rectal carcinoma cell line HR8348 in vitro and the relationship between apoptosis induced by 5-FU and the expression of bcl-2，bcl-xl，bax and p53,and to investigate the possible mechanism of apoptosis of rectal carcinoma cell line HR8348 induced by 5-FU.Methods After treatment with 5-FU for 24 h,the apoptotic index was detected by methyl green and pyronine Y staining and by terminal deoxynucleotidyl transferase (TdT)mediated dUTP nick end labeling (TUNEL).The bcl-2,bcl-xl,bax and p53 gene expression of HR8348 cells were examined by immunohistochemical method.Results After treatment with 5-FU,the apoptotic index of experiment group was significantly increased,there was significant difference as compared with the control.Exposed to 5-FU for 12 h,24 h and 36 h,the expression of bcl-2 of HR8348 cell line remained unchanged,but the expression of bcl-xl slightly diminished,while the expression of bax was remarkly increased,the expression of p53 was not detected in both experiment and control groups.Conclusion This results indicate that 5-FU may induce apoptosis of rectal carcinoma cell line HR8348 and the possible mechanism of apoptosis induction is through upregulation of bax expression and the change of bax to bcl-xl ratio.
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)