Clinical significance of expression of p21 and p53 proteins and proliferating cell nuclear antigen in pancreatic cancer

Objective: To study the clinical significance and effect of p21, p53 protein as well as proliferating cell nuc- lear antigen (PCNA) on the occurrence and develop- ment of pancreatic carcinoma. Method: p21, p53 protein and PCNA expressions were detected in specimens from 30 patients with pancreatic carcinoma and 3 samples of normal pan- creatic tissue by immunohistochemistry. The data were analyzed together with clinical findings. Results: The positive expression rates of p21 and p53 proteins were 75.0% and 57.3% respectively in pan- creatic carcinoma, which were significantly different from those in the normal tissue (P<0.05). p21 and p53 proteins were positively correlated (P<0.05). The positive expression of PCNA was 43.33%± 17.99%, that was significantly higher than that in the normal pancreatic tissue (P<0.05). The expres- sion of PCNA was correlated with the histological grade (P<0.05). The positive expression rate was consistent with the exacerbation of cancer. The ex- pression was also correlated significantly with prog- nosis and p53 expression (P<0.05). Conclusions: The occurrence and development of pancreatic cancer are the result of associated function for many oncogenes and antioncogenes. PCNA may be helpful to identify malignant degree and prognosis of pancreatic cancer.

THE STUDY ON RELATIONSHIP BETWEEN CIGARETTE SMOKING AND THE p53 PROTEIN AND P21 PROTEIN EXPRESSION IN NON-SMALL LUNG CANCER

This paper discusses the relationship between cigarette smoking and the p53 protein and P21 protein expression by the immunohistochemical analysis in 93 cases with lung cancer in which squamous cell carcinoma accounted for 45 cases, adenocarcinoma 48 cases. The results showed that positive proportion of p53 protein expression was 74.20% (28 of 37 squamous cell carcinoma, 21 of 30 adenocarcinomas) in cigarette smoking group with lung cancers, and 38.46% (3 of 8 squamous cell carcinoma, 7 of 18 adenocarcinomas) in nonsmoking group with lung cancers. The difference was statistically significant. Odds ratio was 4.14 and confidence limits for OR was 1.42-12.52. A dose-related presents in the p53 protein expression for the smoking amount and smoking years. The positive proportion of P21 protein expression was 79.31% (21 of 28 squamous cell carcinoma, 25 of 30 adenocarcinomas) in cigarette smoking group with lung cancers, and 82.75% (10 of 11 squamous, 14 of 18 adenocarcinomas) in nonsmoking group with lung cancers, the difference was not statistically significant. But their positive proportion of P21 protein expression were very high in both groups. It was indicated that no relationship between cigarette smoking and the P21 protein expression. We suggest that the p53 gene could be a common target of tobacco-associated carcinogenesis in lung cancer.

Clinical significance of immunohistochemica study of P53 protein in colorectal carcinoma

AIMS To determine the clinical significance of P53 protein ex-pression in colorectal carcinoma.METHODS The expression of P53 protein in 92 colorectal car-cinomas was examined using the monoclonal antibody PAb 1801.Correlation between P53 protein expression and prognosis in col-orectal carcinoma was analyzed using log-rank test.RESULTS The frequency of P53 protein expression was 57.61%,corresponding with Dukes’ staging.Analysis of survivordata demonstrated that the survival rate of colorectal carcinomawith positive P53 protein group was lower than that of negativeP53 protein group.CONCLUSIONS We conclude that the expression of P53 pro-tein is correlated with poor prognosis in colorectal carcinoma.

The Effect of Helicobacter pylori Infection on hMSH2 and P53 Proteins in Gastric Carcinogenesis

OBJECTIVE To investigate the effect of Helicobacter pylori （H pylon） infection on expression of hMSH2 and P53 and its possible carcinogenic mechanism. METHODS H pylori infection was detected using a rapid urease test and haematoxylin and eosin （H＆E） staining. The hMSH2 and P53 proteins in gastric cancer （GC） tissue, its adjacent mucosa, gastritic mucosa and normal gastric mucosa were detected by the immunohistochemical SP method. RESULTS （1） The positive rate of hMSH2 expression in GC tissue （62.7%）was higher than those in non-cancer tissues （P〈0.001）; the positive rate of hMSH2 expression in poorly differentiated adenocarcinoma （76.4%） was higher than that in other carcinomas （P〈0.05）. The positive rate of P53 expression in GC tissue （51.9%） was higher than that in noncancer tissues （P〈0.001）; the positive rate of P53 expression in well-differentiated adenocarcinoma （32.6 %） was lower than that in other carcinomas （P〈0.01）. （2） The positive rate of hMSH2 expression in GC tissue with H pylori infection was lower than that without the infection （52.8% vs. 74.5%; P〈0.05）. The positive rate of P53 expression in GC tissue with H pylori infection was higher than that without the infection （61.4% vs. 40.6%; P〈0.05）.（3） The expression of hMSH2 and P53 in GC tissue correlated positively （r=0.457, P〈0.01）. CONCLUSION High expression of hMSH2 and P53 as well as their interaction may be involved in gastric carcinogenesis; H pylori infection affecting expression of hMSH2 and P53 may be one of its carcinogenic mechanisms.

Clinicopathological significance of p53 and mdm2 protein expression in human pancreatic cancer

AIM: To study the clinicopathological significance of p53 and mdm2 protein expression in human pancreatic cancer. METHODS: To investigate the expression of p53 and mdm2 in pancreatic cancer by immunohistochemistry, and the relationships between the p53 and mdm2 protein expression and clinicopathological parameters in pancreatic cancer.RESULTS: The positive expression of p53 protein was found in 40 of 59 patients (67.8%) and that of mdm2 protein in 17 of 59 patients (28.8%). No obvious relationships were found between p53 as well as mdm2 expression and sex, tumor site, TNM staging and histological differentiation. p53 expression was increased in patients younger than 65 years old, while mdm2 had no relationship with age. The survival time of the patients with the positive expression of p53 and mdm2 proteins was obviously shorter than the other groups. CONCLUSION: Both p53 and mdm2 presented relatively high expression in human pancreatic cancer. The overexpression of p53 and mdm2 might reflect the malignant proliferation of pancreatic cancer and their co-expression might be helpful to evaluate the prognosis of the patients with pancreatic cancer.

p53 MUTATIONS AND PROTEIN OVEREXPRESSION IN PRIMARY COLORECTAL CANCER AND ITS LIVER METASTASIS

Objective: To compare p53 status in primary and hepatic metastatic colorectal cancer in 34 patients. Methods: p53 gene status (exons 5–9) was examined by PCR, denaturing gradient gel electrophoresis (DGGE) and automated sequencing. P53 protein was detected by immunohistochemistry using monoclonal antibody DO-7. Results: p53 mutations were found in exons 5 through 9 in 21 of 34 patients (61.8%). Among them, 5 patients had mutation in liver metastasis but not in their primary tumors while in the other patients the same mutations were found in both primary and metastatic colorectal cancers. In no patients was p53 mutation exclusively found in the primary colorectal tumors. Moreover, additional mutation was detected in the metastatic lesions in two cases. Of the 37 mutations within the exons examined, 73% was missense mutation and 16% was nonsense mutation. There were 4 microinsertions. p53 protein was overexpressed in both primary and metastatic colorectal cancers with p53 gene mutations. The presence of p53 mutation significantly correlated with p53 protein accumulation (r=0.96,P<0.001). However, in 4 patients with p53 nonsense mutation, immunohistochemical staining was negative. In three patients who showed no p53 mutation of the primary tumor, p53 protein was consistently overexpressed. Conclusion: In colorectal cancers, p53 gene mutation usually appears first in the primary tumor and maintains as such but is more prominent when metastasized to the liver. However, p53 gene mutation may occur only after being metastasized. Although p53 gene mutation and p53 protein overexpression correlate with each other, either parameter examined alone may lead to false positive or negative results.

Study on the p53 Protein Expression in Gastric Cancer and Precancerous Lesions by Flow Cytometry

At present, p53 gene and its product p53 protein are the hot spot in the field of cancer research. 50% human malignant tumors are associated with p53 alteration. p53 gene mutation is the most common mutation, which can lead to regulation disturbance of cell proliferation. Gastric cancer is the most common disease in China. Its incidence is the second among various malignant tumors.There were reports about p53 protein expression and gastric cancer progression but few report on p53 protein expression in different stages of precancerous lesions was available. In this study,we analyzed p53 protein expression in gastric cancer and precancerous lesions by flow cytometry to evaluate the role of p53 protein in the pathogenesis of gastric cancer.

Down-expression of tumor protein p53-induced nuclear protein 1 in human gastric cancer

AIM： Overexpression of tumor protein p53-induced nudear protein 1 （TP53INP1） induces G1 cell cycle arrest and increases p53-mediated apoptosis. To clarify the clinical importance of TP53INP1, we analyzed TP53INP1 and p53 expression in gastric cancer, METHODS： TP53INP1 and p53 expression were examined using immunohistochemistry in 142 cases of gastric cancer. The apoptosis of gastric cancer cells was analyzed using the TUNEL method. The relationship between the expression of TP53INP1 and clinicopathological factors was statistically analyzed. RESULTS： TP53INP1 was expressed in 98% （139/142 cases） of non-cancerous gastric tissues and was downexpressed in 64% （91/142 cases） of gastric cancer lesions from the same patients. TP53INP1 expression was significantly decreased （43.9%） in poorly differentiated adenocarcinoma compared with well or moderately differentiated adenocarcinoma （81.6%）. Cancers invading the submucosa or deeper showed lower positively （59.1%） compared with mucosal cancers （85.2%）. Decrease or loss of TP53INP1 expression was significantly correlated with lymphatic invasion （54.3% vs 82.0% without lymphatic invasion） and node-positive patients （31.3% vs 68.3% in node-negative patients）. P53 was expressed in 68 （47.9%） patients of gastric cancer, whereas it was absent in normal gastric tissues. A significant association was also observed between TP53INP1 status and the level of apoptosis in tumor cells： the apoptotic index in TP53INP1-positive tissues was significantly higher than that in TP53INP41-negative portions. Finally, when survival data were analyzed, loss of TP53INP1 expression had a significant effect in predicting a poor prognosis （P= 0.0006）.CONCLUSION： TPS3INP1-positive rate decreases with the progression of gastric cancer. TPS3INP1 protein negativity is significantly associated with aggressive pathological phenotypes of gastric cancer. TPS3INP1 is related to the apoptosis of gastric cancer cells. The decreased expression of the TPS3INP1 protein may reflect the malignant grade of gastric cancer and is regarded as an adverse prognostic factor.

Expression of the chemoresistance-related proteins and p53 gene as a predictor of chemotherapy response and a prognostic factor in patients with ovarian cancer at the stages of II-IV

Objective To clarify the prognostic significance of histologic subtype and its correlation to expression of chemoresistance-related proteins （CRPs） in ovarian cancer. Methods A total of 107 stage II-IV ovarian cancers, where the proportion of serous, endometrioid, mucinous, and clear cell subtype was 62.6%, 15.9%, 14.0%, and 7.5%, respectively, were investigated for glutathione Stransferase-pi （GST-pi）, MDR （multidrug resistance）-l, and p53 expression using immunohistochemistry. Results GST-pi expression was detected in 62.6% of the tumors and was not related to histologic subtype of tumor. MDR-1 expression was observed in 52.3% of the tumors tested and was more frequently detected in serous adenocarcinomas than other histologic subtypes of tumor （P〈0.001）. P53 expression was found in 43.3% of serous, 35.3% of endometrioid, 40.0% of mucinous adenocarcinomas and 37.5% of clear cell adenocarcinomas. In univariate analysis, there are direct correlations between CRPs and overall survival. In multivariate analysis, GST-pi expression （P=0.0052）, MDR-1 expression （P=0.0058）, histologic subtype （P=0.0067）, FIGO stage （P=0.0089）, and residual tumor （P=0.0041） were found to be significant independent prognostic factors. Conclusion Histologic subtype proved to be the significant independent prognostic factor in addition to FlGO stage and residual tumor in stage II-IV ovarian cancer. GST-pi, MDR-1, and p53 expression pattern is closely related to histologic subtype of ovarian cancer, at the same time they are the significant predictors of survival.

Effect of Boschniakia rossica on expression of GSTP,p53 and p21^(ras)proteins in early stage of chemical hepatocarcinogenesis and its anti-inflammatory activities in rats

AIM To investigate the effect of Boschniakiarossica（BR）extract on expression of GST-P,p53 and p21rasproteins in early stage of chemicalhepatocarcinogenesis in rats and its anti-inflammatory activities.METHODS The expression of tumor marker-placental form glutathione S-transferase（GST-P）,p53 and p21rasproteins were investigated byimmunohistochemical techniques and ABCmethod.Anti-inflammatory activities of BR werestudied by xylene and croton oil-induced mouseear edema,carrageenin,histamine and hotscald-induced rat pow edema,adjuvant-inducedrat arthritis and cotton pellet-induced mousegranuloma formation methods.RESULTS The 500 mg/kg of BR-H2O extractfractionated from BR-Methanol extract hadinhibitory effect on the formation of DEN-inducedGST-P-positive foci in rat liver（GST-P stainingwas 78% positive in DEN+AAF group vs 20%positive in DEN+AAF+BR group,P【0.05）andthe expression of mutant p53 and p21rasproteinwas lower than that of hepatic preneoplasticlesions（33% and 22% positive respectively inDEN+AAF group vs negative in DEN+AAF+BRgroup）.Both CH2Cl2 and H2O extracts from BRhad anti-inflamatory effect in xylene and crotonoil-induced mouse ear edema（inhibitory rateswere 26%-29% and 35%-59%,respectively）. BR-H2O extract exhibited inhibitory effect incarrageenin,histamine and hot scald-inducedhind paw edema and adjuvant-induced arthritis inrats and cotton pellet-induced granulomaformation in mice.CONCLUSION BR extract exhibited inhibitory effect on formation of preneoplastic hepatic foci in early stage of rat chemical hepato-carcinogenesis. Both CH2CI2 and H2O extracts from BR exerted anti-inflammatory effect in rats and mice.

Correlation of p53 over-expression and alteration in p53 gene detected by polymerase chain reaction-single strand conformation polymorphism in adenocarcinoma of gastric cancer patients from India

AIM： To study the alterations in p53 gene among Indian gastric cancer patients and to correlate them with the various clinicopathological parameters. METHODS： A total of 103 gastric cancer patients were included in this study. The p53 alterations were studied by both immunohistochemical method as well as polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） analysis. We only studied four （exon 5, 6, 7, and 8） of the 11 ,p53 exons. The alterations in p53 were also correlated with respect to various clinicopathological parameters. RESULTS： Among 103 cases, p53 over-expression and alteration were detected in 37 （35.92%） and 19 （18.44%） cases, respectively. Most of the ,p53 alterations were found at exon 5 （31.54%）, followed by exon 6 （26.31%）, exon 7 （21.04%） and exon 8 （21.04%）. A significant correlation of p53 overexpression was found with p53 alteration （P = 0.000）. Concordance between ,p53 alteration （as detected by SSCP） and over-expression [as detected by immunohistochemistry （IHC）] was found in 75% cases. We found that IHC-positive/SSCP-negative cases accounted for 21% of cases and IHC-negative/SSCP- positive cases accounted for remaining 4% cases. CONCLUSION： Our results show that p53 gene mutations are significantly correlated with p53 protein over-expression, with 75% concordance in over-expression and alteration in the p53 gene, but 25% disconcordance also cautions against the assumption that p53 over-expression is always associated with a gene mutation. There may be other mechanisms responsible for stabilization and accumulation of p53 protein with no evidence of gene mutation that reflect an accumulation of a non-mutated protein, or a false negative SSCP result.

Using p53-immunostained large specimens to determine the distal intramural spread margin of rectal cancer

AIM： To determine the distal intramural spread （DIS） margin of rectal cancer.METHODS： Sixty-one p53-positive specimens of rectal cancer were used. After conventional hematoxylin and eosin （H＆E） staining, the DIS margin of rectal cancer in large specimens was examined by immunohistochemistry. The patients were divided into A, B, C, and D groups. After a long-term follow-up, the survival curves of the four groups were estimated using the life table. RESULTS： Fifty-one of the sixty-one cases （83.6%） had DIS. The extent of DIS ranged 0.11-3.5 cm; meanwhile the.mean of DIS measured by H＆E staining was 0.13 cm. The significant difference was found between the means （t=5.622, P〈0.0001）. Only 1 of 51 patients had DIS greater than 3 cm. The DIS was less than 1.0 cm in most rectal cancer patients. The long-term results indicated that the survival rate of the patients whose DIS was greater than 1.0 cm was lower than that of the patients whose DIS was less than 0.5 cm. CONCLUSION： Rectal cancer patients with DIS greater than 1.0 cm have poor prognosis.

Relationship between somatostatin receptor subtype expression and clinicopathology,Ki-67,Bcl-2 and p53 in colorectal cancer

AIM： To study the SSTR1, 2, 3, 4, 5 expression and their relationships with clinico-pathological factors, cell proliferation, Bcl-2 and p53 expression in colorectal cancer cells. METHODS： Immunohistochemical staining of five SSTR subtypes, Ki-67, Bcl-2 and p53 was performed by the standard streptavidin-peroxidase （SP） technique for the paraffin sections of 127 colorectal cancers, and expression of five SSTR subtypes in 40 specimens of normal colorectal mucosae was detected with the same method. RESULTS： Positive staining for five SSTR subtypes was observed in colorectal cancer cells and normal colorectal mucosae. SSTR1 was the most predominant subtype in both colorectal cancer and normal colorectal mucosa, and the second was SSTR5 or SSTR2. As compared with normal colorectal mucosa, SSTR4 was more frequently expressed in colorectal cancer cells （2.5% vs 18.9%, P〈 0.05）; the expression of SSTR2, 4, 5 in moderately to well differentiated colorectal adenocarcinoma was significantly higher than that in poorly differentiated ones （P〈 0.05）, the SSTR1 expression in colorectal cancer with positive lymph node metastasis was significantly higher than that with negative lymph node metastasis （72.2% and 54.5%, P〈 0.05）. In addition, in the ulcerative type of colorectal cancer, SSTR2 expression was obviously decreased （P 〈 0.05）; the correlation did not reach a statistical significance between the five SSTR subtypes expression and Dukes＇stages （P〉 0.05）, but the frequency of SSTR1 expression increased with Dukes＇ stage, while SSTR3 and SSTR5 expression decreased with Dukes＇ stage. Moreover, there was no correlation between expression of the five SSTR subtypes and other clinicopathological factors such as age, sex, tumor site, tumor depth, distant metastasis. The proliferative indexes in colorectal cancer cells with negative expression of SSTR2 and SSTR3 were significantly higher than that with positive expression （P〈0.05）. The Bcl-2 expression in colorectal cancer cells with positive expression of SSTR1, 2, 3, 5 was significantly lower than that with negative expression （P〈 0.05）. There was no correlation between five SSTR subtypes and p53 expression. CONCLUSION： The most predominant SSTR subtype is SSTR1, and the second is SSTR2 or SSTR5, Five SSTR subtypes play different roles in the development of colorectal cancer, SSTR2 and SSTR3 can inhibit the proliferation and promote apoptosis of tumor cells.

Expression of p27kip1, Rb protein and proliferating cell nuclear antigen and its relationship with clinicopathology in human pancreatic cancer

OBJECTIVE: To investigate the effect of inhibiting factor of cell cycle regulation p27kipl,retinoblastinoma protein （Rb protein）, and proliferating cell nuclear antigen （PCNA） on the genesis andprogression of human pancreatic cancer.METHODS: The expression of p27kipl, Rb protein and PCNA in the tumor tissue and adjacent tissue of32 patients with pancreatic cancer was detected by SP immunohistochemical technique.RESULTS: The p27kipl protein positive-expression rate in the tumor tissue of pancreatic cancer was56.25%, which was lower than that in the adjacent pancreatic tissue （P【0.05）. p27kipl proteinpositive-expression was correlated significantly with tumor cell differentiation and lymph node metastasis（P【0.05）. The Rb gene protein positive-expression rate in the tumor tissue was 50%, which was alsolower than that in the adjacent pancreatic tissue （P【0.05 ）. The PCNA positive-expression rate was71.87%, which was higher than that in the adjacent pancreatic tissue （P【0.05）. PCNA positive-expression was also correlated significantly with tumor cell differentiation and lymph node metastasis（P【0.05）.CONCLUSION: The decreased expression of p27kipl, Rb protein and over-expression of PCNA may playan important role in the genesis and progression of pancreatic cancer.

EXPRESSION OF FRAGILE HISTIDINE TRIAD AND P53 IN NON-SMALL CELL LUNG CANCER

Objective： To investigate the expression offragile histidine triad （FHIT） and p53 protein in non-small cell lung cancer （NSCLC） and explore the relationship between their expressions and the clinicopathological features. Methods： FHIT protein and p53 protein were detected by immunohistochemistry in 76 cases of NSCLCs and matched normal lung tissues. Results： Fifty-one cases （67.1%） showed negative expression of FHIT （apparent reduction or loss） and thirty-seven cases （48.7%） showed p53 positive expression （overexpression）. The difference was significant （P=0.04）. However, there was no significant difference in FHIT expression between the p53-positive group and the p53-negative group （64.9% versus 69.2%, P=0.686）. The negative rate of FHIT protein expression was higher in squamous cell carcinoma than in adenocarcinoma, in moderately and poorly differentiated carcinoma than in well-differentiated carcinoma, and in cases with smoking history than in cases without smoking history （P〈0.05）. There was no relationship between FHIT expression and clinical stage or lymph node metastasis. The negative FHIT expression was not an independent predictor of overall survival （P=0.338）. Conclusion： The frequency of negative expression of FHIT protein is higher than that of positive expression of p53 in NSCLCs. The negative expression of FHIT is independent of the expression of p53. The change of expression of FHIT may play a role in the smoking related lung tumorigenesis while it may have no relationship with the progress of NSCLC or prognosis of the patients.

MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

BACKGROUND Radiotherapy stands as a promising therapeutic modality for colorectal cancer(CRC);yet,the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.AIM To elucidate the role played by microRNA-298(miR-298)in CRC radio-resistance.METHODS To establish a radio-resistant CRC cell line,HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period.The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR,and protein expression determination was realized through Western blotting.Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay.Radio-induced apoptosis was discerned through flow cytometry analysis.RESULTS We observed a marked upregulation of miR-298 in radio-resistant CRC cells.MiR-298 emerged as a key determinant of cell survival following radiation exposure,as its overexpression led to a notable reduction in radiation-induced apoptosis.Intriguingly,miR-298 expression exhibited a strong correlation with CRC cell viability.Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A(DYRK1A)as miR-298’s direct target.CONCLUSION Taken together,our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation,thereby positioning miR-298 as a promising candidate for mitigating radioresistance in CRC.

The Effect of Helicobacter Pylori Infection on Expression of hMSH2, hMLH1 and p53 in Gastric Carcinogenesis

Objective： To detect the expression of hMSH2, hMLH1 and p53 in gastric epithelial cells with and without Helicobactcr pylori （H. pylori） infection and investigate the relationship between H. pylori infection and these genes in gastric carcinogenesis. Methods： H. pylori infection was detected by rapid urease tests. Expression of hMSH2, hMLHland p53 in gastric cancer （GC） tissue, its adjacent mucosa, gastritic mucosa and normal mucosa was assessed by immunohistochemistry SP method. Results： Positive expression rate of hMSH2 in GC tissue （62.7%） was higher than those in adjacent mucosa （29.4%）, gastritic mucosa （32.4%） and normal mucosa （30.0%） （P〈0.001）. Positive rate of hMSH2 in poorly differentiated adenocarcinoma （76.4%） was higher than those in other carcinomas （54.3%, 53.1%） （P〈0.05）. Positive expression rate of hMLH1 in GC tissue （64.3%） mucosa （82.4%） and normal mucosa （80.0%） was lower than those in adjacent mucosa （84.4%）, gastritic （P〈0.01）. Positive rate of hMLH1 in mucoid carcinoma （43.7%） was lower than those in other carcinomas （78.2%, 64.7%） （P〈0.01）. Positive expression rate of p53 in GC tissue （51.9%） was higher than those in adjacent mucosa （3.1%）, gastritic mucosa （0.0%） and normal mucosa （0.0%） （P〈0.001）. Positive rate of p53 in well differentiated adenocarcinoma （32.6%） was lower than those in other carcinomas （58.8%, 68.7%） （P〈0.01）. Positive rates of hMSH2 and hMLH1 in GC with H. pylori infection were lower than those without the infection, respectively （P〈0.05）. Positive rate of p53 in GC with H. pylori infection （61.4%） was higher than that without the infection （40.6%） （P〈0.05）. Conclusion： Gastric carcinogenesis may be associated with abnormal expression of hMSH2, hMLH1 and p53; H. pylori infection affecting expression of these genes may be one of its carcinogenic mechanisms.

THE OVEREXPRESSION AND SIGNIFICANCE OF CYCLIN D1 AND P53 IN CERVICAL SQUAMOUS CELL CARCINOMAS

Objective To investigate the significance of overexpresson of cyclin D1 and P53 protein in cervical squamous cell carcinomas.Methods Fifty cases of invasive cervical squamous cell carcinomas and 10 cases of normal cervical squamous epithelia were investigated with immunihistochemical technique. Results The overexpression of cyclin D1 and P53 in invasive cervical carcinomas was 70% and 50%, respectively. There was no overexpression of them in the control group. The overexpression of cyclin D1 in grade Ⅱ and Ⅲ was much higher than that in gradeⅠ(P<0.05). The overexpresson of cyclin D1 in stage Ⅲ of cervical carcinoma was significantly higher than that in stage Ⅱ (P<0.05). The overexpression of P53 in grade Ⅱ and grade Ⅲ of cervical carcinoma was remarkably higher than that in grade Ⅰ (P<0.05).Conclusion The action point of both cyclin D1 and P53 may be at G1/S transition. The overexpression of them was associated with development and progression of cervical carcinoma probably in different mechanisms and different pathways.

肺未分化癌p53基因蛋白的表达和预后相关性的研究

采用ＡＢＣ免疫组织化学法对６０例肺未分化癌进行ｐ５３蛋白阳性表达的研究。结果显示ｐ５３蛋白在肺大、小细胞癌的表达率皆为６３．３％，两者间无差异。在大细胞癌病例中，ｐ５３核浆型阳性者１年生存期较胞浆为主型阳性者为长，两者间无统计学意义。肺未分化癌ｐ５３过度表达者，其１年及半年生存率有增加倾向，但无统计学意义。大细胞癌ｐ５３阳性者其淋巴结转移率为８７．５％，两者呈正相关（Ｐ＜０．０５）。大小细胞癌中ｐ５３蛋白阳性者均易有远处转移，提示ｐ５３蛋白与肿瘤的晚期发展有关。同时，还证明癌旁的原位癌及不典型增生的肺泡上皮亦可呈ｐ５３蛋白阳性，而在正常组织则未见ｐ５３蛋白表达。作者认为ｐ５３蛋白有可能作为早期诊断的一个参考指标。

CIN和子宫颈鳞癌的HPV16/18感染与p53、MDM2蛋白表达的关系

目的研究子宫颈鳞癌及C IN的HPV感染、p53蛋白和M DM 2蛋白的表达及三者之间的相互关系。方法选取子宫颈鳞癌61例、C IN 47例、正常子宫颈组织54例,分别采用原位杂交技术检测HPV 16/18感染,用免疫组化技术S-P法检测p53蛋白和M DM 2蛋白。结果HPV 16/18感染率鳞癌组为62.3%(38/61),C IN组为70.2%(33/47),对照组为16.7%(9/54)。C IN组和鳞癌组的HPV 16/18的感染率均显著高于对照组(P值均<0.05)。而C IN组与鳞癌组的HPV 16/18感染率差异无显著性(P>0.05)。C IN组、鳞癌组、对照组的p53阳性率分别为19.1%(9/47)、26.2%(16/61)、3.7%(2/54)。C IN组、鳞癌组、对照组的M DM 2阳性率分别为14.9%(7/47)、26.2%(16/61)、7.4%(4/54)。C IN组和鳞癌组的p53阳性率均显著高于对照组(P值均<0.05),C IN组与鳞癌组比较差异无显著性(P>0.05)。M DM 2阳性率鳞癌组显著高于对照组(P<0.05),而在C IN组和鳞癌组之间、C IN组和对照组之间差异均无显著性(P值均>0.05)。在本实验各组中,p53与M DM 2之间的阳性率均无统计学相关(P值均>0.05)。p53阳性率和HPV 16/18感染之间差异无显著性(P值均>0.05),而M DM 2的阳性率与HPV 16/18感染仅在子宫颈鳞癌组呈正相关(P<0.05)。结论C IN及子宫颈鳞癌与HPV 16/18感染关系密切;p53和M DM 2均参与子宫颈癌及癌前病变的发生,但p53的突变、M DM 2的扩增和过表达均不占主导地位。