Determination of proliferative activity using Ki67 and expression of p53 in colorectal cancer

BACKGROUNDS AND PURPOSE: Classically, neoplasia has been considered a disturbance in the regulation of proliferation. In the search of a prognostic discriminant, the distribution of Ki67 as a marker of cell proliferation and the expression of p53 was studied in patients with colorectal cancer, to see whether this marker correlate with clinicopathological aspects. PATIENTS AND METHODS: Formalin-fixed paraffin-embedded tissues from 38 surgically resected adenocarcinomas of colon and rectal (5 Dukes A, 15 B and 18 C) were examined for p53 and Ki67 reactivity by immunohistochemistry (Dako). Nuclear staining of 5% of the cells was the criterion for a positive p53 reaction. For the study of Ki67 10 or more fields were chosen until 1000 nuclei per specimen were counted. The Ki67 labelling indices was determined by the number of positive nuclei/1000 cells. Correlation was done with the Dukes stage, grade of differentiation and percentual of recurrence. RESULTS: The mean Ki67 labelling indices was 40. The p53 was positive in 79% of the patients. The mean of Ki67-Li was higher in the positive p53 patients. However we did not lymphatic find differences between Ki67 or p53 expression and sex, age, Dukes stage, grade of differentiation, neural, venous or lymphatic invasion or recurrence. CONCLUSION: Ki67 and p53 could not be correlated to clinical and pathologic parameters in this study and was of limited use as a prognostic discriminant. The positive p53 cancers have more proliferative activity detected by a higher index of Ki67.     

Apoptosis of colon cancer: Comparison with Ki-67 proliferative activity and expression of p53

The role of apoptosis in colon cancer was investigated in terms of control of growth and expression of p53, using the nick-ended-DNA labelling method and immunohistochemistry. The apoptotic labeling index was highest in the T1 stage (24 cases), as was the proliferative activity, assessed in terms of the Ki-67 labeling index. Both labeling indices demonstrated similar overall incidence curves for the total 95 colon cancer cases, and examination of individual cases revealed a statistically significant correlation (P=0.01). However, neither index had any relation to p53. The results thus suggest that apoptosis in colon cancers has a linkage with proliferative activity that can be assessed by Ki-67 labeling, but is not regulated by the p53 system. This might contribute to the diversity of colon cancer growth.     

A p53 genetic polymorphism of gastric cancer: Difference between early gastric cancer and advanced gastric cancer

AIM: To investigate the role of the polymorphism of p53 codon 72 in early gastric cancer (EGC) and advanced gastric cancer (AGC) in Korean patients.METHODS:DNA was extracted from blood samples of gastric cancer patients (n = 291) and controls (n=216).tn the p53 codon 72 genotypes were determined by PCR-RFLP.RESULTS: Patients with gastric cancer had a significantly higher frequency of the homozygous proline (Pro) allele than the control (P=0.032). Patients with AGC had a significantly higher frequency of the Arg/Arg (arginine)allele (P=0.038) than EGC and a similar Pro/Pro allele.The signet ring cell type had a higher frequency of the Pro/Pro allele than other types (P=0.031). The Pro/Pro genotype carries a 3.9-fold increased risk of developing gastric cancer (95% CI,1.3-15.4,P=0.039)when compared to Arg/Arg and Arg/Pro genotypes and to develop EGC is a 5.25 fold increased risk (95% CI,1.8-19.6,P=0.021).CONCLUSION: The Pro/Pro genotype of the p53 codon 72 polymorphism carries a higher risk for gastric cancer in general and is also associated with a much higher risk for EGC than AGC.     

A p53 genetic polymorphism of gastric cancer： Difference between early gastric cancer and advanced gastric cancer

INTRODUCTIONGastric cancer is one of the most common malignancies worldwide,although the overall incidence of gastric cancer has been decreasing over the past few decades.Chronic H pylori infection and dietary factors,such as those high in salt or nitrate…     

p53 protein expression in resected invasive esophageal cancer

Many studies have reported the increased expression of p53 protein in various human malignancies and its accumulation have been considered an intermediate biomarker in multistage carcinogenesis. This study was designed to evaluate p53 expression by immunohistochemistry using Dako p53, D0-7 monoclonal antibody in 33 resected invasive squamous cell esophageal cancers (SqCC). The relationship between p53 immunoreactivity and clinicopathologic parameters was determined by the Chi-square test and Student's t test. p53 protein overexpression (more then 10% positive staining cancer cells) was found in 15 out of 33 (45%) tumors. Positive test was found in 38% cases in Stage IIA, 57% in Stage IIB, 45% in Stage III and 50% cases in Stage IV. p53 overexpression was observed in 48% of tumors with lymph nodes metastases, and 41% of tumors without lymph nodes metastases. In respect of tumor differentiation, cases graded as G1, G2 and G3 were positive in 50%, 50% and 40%, respectively. Thirteen per cent of patients with p53 protein overexpression and 16% of patients without p53 protein overexpression survived more than 3 years. There was no correlation between p53 overexpression and stage, tumor differentiation, lymph nodes metastases, and patients survival. In conclusion our results showed that p53 overexpression did not correlate with clinicopathologic feature of invasive SqCC of the esophagus and p53 protein overexpression was unsuitable for predicting the outcome of patients after surgical resection.     

Epithelial cell turnover, p53 and bcl-2 protein expression during oncogenesis of early and advanced gastric cancer in a Western population

OBJECTIVES: To investigate epithelial cell turnover alterations, and p53, bcl-2 protein expression during development of early and advanced gastric cancer in a Western population. METHODS: We investigated cell apoptosis and proliferation rates, p53 and bcl-2 protein expression in 17 early and 34 advanced gastric carcinomas and in the adjacent non-dysplastic mucosa. Cell proliferation, p53 and bcl-2 expression were detected immunohistochemically using MIB-1, anti-p53 and anti-bcl-2 monoclonal antibodies. Apoptosis was measured by TUNEL. The rate of the positive stained cells (labelling index) was count using image analysis technique. RESULTS: No difference was observed of either apoptotic (10 vs. 11) or proliferation (35 vs. 25) index between early and advanced cancers. However, the apoptotic index was significantly higher in intestinal type advanced tumors. While both apoptotic and proliferation indices were significantly higher in tumors than in the adjacent mucosa, no difference was observed of either apoptotic (2 vs. 2) or proliferation (8 vs. 13) index between the tissues adjacent to early and advanced tumors. p53 protein expression was significantly higher in advanced cancers (7 vs. 5, p=0.001) and in the non-dysplastic tissue adjacent to advanced tumors (3.5 vs. 2, p=0.001). bcl-2 labelling index was significantly higher in the mucosa adjacent to advanced carcinomas (15 vs. 5, p=0.016) but this difference did not reach significance in the tumors (20 vs. 15, p=0.37). CONCLUSIONS: Our data indicate similar cell turnover during tumorigenesis of early and advanced cancer. p53 and bcl-2 protein accumulation is more intense in gastric mucosa adjacent to advanced tumors and p53 immunoreactivity peaks in advanced carcinomas.     

Prognostic significance of Bcl-2 and p53 expression in gastric cancer

Background and aims Apoptosis regulates cell death and influences cell proliferation and therefore may play an important role in development or growth of various malignant tumors. The Bcl-2 and p53 are closely linked in the regulation of apoptosis. We investigated the prognostic significance of Bcl-2 and p53 expression in patients with gastric cancer.Patients and methods Immunohistochemistry was used to study Bcl-2 and p53 expression in 308 consecutive patients with gastric cancer.Results Bcl-2 expression was positive in 39 patients (12.7%) and showed a significant negative correlation with depth of invasion and lymph node metastasis. p53 expression was observed in 105 patients (34.1%) and was significantly associated with depth of invasion, lymph node metastasis, distant metastasis, and intestinal type. Patients with Bcl-2⁺ tumors showed a trend to better 5-year survival rate (81%) than those with Bcl-2^– negative tumors (71%). The 5-year survival rate in p53 positive cases (60%) was significantly lower than that in p53-negative cases (78%). In addition, p53 expression showed a significantly poorer prognosis in both diffuse and intestinal types. In multivariate analysis restricted to patients with R0 resection p53 expression was an independent prognostic factor (relative risk: 2.063). In combined assessment of p53 and Bcl-2 expression the group with p53⁺/Bcl-2^– tumors showed significantly worse 5-year survival (57%) than the other groups, while best survival was seen in the group with p53⁺/Bcl-2⁺ tumors (100%).Conclusion p53 expression is an unfavorable prognostic factor in gastric cancer. Bcl-2 expression may have possible prognostic value when combined with p53 expression.     

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

AIM: Overexpression of tumor protein p53-induced nuclear 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 down-expressed 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 TP53INP1-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: TP53INP1-positive rate decreases with the progression of gastric cancer. TP53INP1 protein negativity is significantly associated with aggressive pathological phenotypes of gastric cancer. TP53INP1 is related to the apoptosis of gastric cancer cells. The decreased expression of the TP53INP1 protein may reflect the malignant grade of gastric cancer and is regarded as an adverse prognostic factor.     

Anti-p53 antibodies and p53 protein expression in cholangiocarcinoma

BACKGROUND/AIMS: Mutations of p53 are found in the majority of human malignancies. The accumulated mutant p53 can be detected in tumor sections by immunohistochemical methods. The abnormal accumulation of the defective p53 protein can induce the host to develop anti-p53 antibodies in sera of cancer patients. This study aimed to investigate the presence of anti-p53 antibodies in sera of patients with cholangiocarcinoma and to evaluate the correlation between such antibodies and p53 protein accumulation. METHODOLOGY: The presence of serum anti-p53 antibodies in 49 patients with cholangiocarcinoma was determined by ELISA kit (Pharma Cell, France). Immunohistochemical detection of p53 protein expression was examined in available tissue samples of 36 patients. RESULTS: Serum anti-p53 antibodies were detected in 6 of 49 patients with cholangiocarcinoma (12.2%). Immunostaining of p53 was found in 15 of 36 patients (41.6%) and 4 of these 15 patients (26.7%) were positive for anti-p53 antibodies. The association between anti-p53 antibodies and p53 protein expression was statistically significant (P=0.023). No correlation was found between the presence of anti-p53 antibodies and sex, age, histological grade, site and stage of tumor (P>0.05). CONCLUSIONS: The majority of serum anti-p53 antibodies detected in cholangiocarcinoma were specifically associated with the accumulation of p53 protein in tumor tissues. However, antibody generation against the p53 protein is a relatively uncommon event in cholangiocarcinoma.     

Correlation between cyclooxygenase-2, proliferative activity,and mucin phenotype in human advanced gastric cancer

Background Recent studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of gastrointestinal cancer, and that cyclooxygenase-2 (COX-2) may be a target enzyme for the prevention or regression of cancer by the use of NSAIDs. Mucin histochemistry has made possible a clear distinction between the differentiated characteristics of gastrointestinal epithelial cells, and the possibility that phenotypic shifts from gastric- to intestinal-type in gastric carcinoma progression has been suggested. To evaluate the role of COX-2 in gastric cancer progression, we immunohistochemically investigated COX-2 expression, and examined its relationship to proliferative activity, mucin phenotype, and clinicopathological parameters in human advanced gastric carcinomas.Methods Forty-five surgical specimens of advanced gastric carcinomas (invaded the muscularis propria or subserosa) were examined. Immunohistochemical staining was performed with monoclonal antibodies against COX-2, Ki-67, CD10 (brush border), MUC-2 (goblet-cell mucin), MUC-5AC (gastric foveolar mucin), and MUC-6 (pyloric mucin). COX-2 expression was scored by the percentage of COX-2-positive neoplastic cells, and proliferative activity was assessed by the Ki-67 labeling index at the deepest area of invasion. The mucin phenotype of the carcinomas was classified into three categories; gastric, intestinal, and unclassified.Results COX-2 staining was restricted to the cytoplasm, not only in cancer cells but also in intestinal metaplasia and some inflammatory cells and COX-2 expression in cancer cells varied greatly, but the staining in some samples was preferentially found at the invasive front. COX-2 positivity was found to correlate with Ki-67 labeling. The mean COX-2 scores were 2.29%, 2.71%, and 2.75%; and the Ki-67 labeling indices were 23.6%, 40.6%, and 56.5%, in gastric-, intestinal-, and unclassified- type carcinomas, respectively.Conclusions A close relationship between COX-2 expression and proliferative activity was confirmed in the deepest areas of advanced gastric carcinoma, and the proliferative activity increased from gastric- to intestinal- and to unclassified- type gastric carcinoma, suggesting a role for COX-2 expression and differences in biological behavior according to mucin phenotype expression during gastric cancer progression.     

p53 C-myc和P-gp蛋白在胃癌细胞中表达

目的研究胃癌组织中ｐ５３和Ｃｍｙｃ的表达与多药耐药性（ＭＤＲ）的关系．方法应用ＬＳＡＢ免疫组织化学方法研究６７例（男４１例，女２６例，平均年龄４６±１５８岁）胃癌标本中ｐ５３，Ｃｍｙｃ和Ｐｇｐ的表达．结果本组胃癌中ｐ５３阳性３２例（４７８％），Ｃｍｙｃ阳性３７例（５５２％），Ｐｇｐ阳性３９例（５８２％）．淋巴结转移阳性胃癌ｐ５３阳性率（５６９％）和Ｃｍｙｃ阳性率（６４７％）显著高于淋巴结转移阴性的胃癌（Ｐ＜００５）．ｐ５３的异常表达与ｍｄｒ１基因表达呈显著正相关（ｒ＝０６３，Ｐ＜００５），而Ｃｍｙｃ和ｍｄｒ１的表达无明显相关．结论ｐ５３异常表达可增加ｍｄｒ１基因的表达，从而使胃癌细胞获得ＭＤＲ表型     

原发性胃癌p53基因突变

目的 p53基因是当前抑癌基因研究中的热点之一。迄今,有关 p53基因异常与胃癌临床病理学参数如大体类型、临床分期、组织分化程度,浸润深度及淋巴结转移之间的关系尚无定论。Tumura 报告p53基因改变主要发生于异倍体瘤,国内尚无报道。本实验目的主要是分析中国人原发性胃癌 p53基因突变与这些病理参数,包括 DNA 倍体之间的关系。方法用聚合酶链式反应—单构象多态分析(PCR—SSCP)技术对20例原发性胃癌 p53基因外显子5—8突变进行检测。结果 8例(40%)发生了突变,其中2例发生在外显子7,4例发生在外显子8。0至Ⅲ期均有突变存在。66.7%(6/9)的异倍体瘤检测到了p53突变,而二倍体瘤中只有18.2%(2/11)发生了 p53突变。结论 p53基因突变与胃癌临床病理参数如大体类型、分期、组织分化程度、浸润深度及淋巴结转移之间无明显关系,而与胃癌 DNA 倍体改变有关。     

组织微阵列技术对胃癌组织p53和MDM2蛋白表达的同步检测与对应分析

目的:探讨胃癌组织中p53和MDM2蛋白表达的相互关系.方法:47例石蜡包埋胃癌组织制成组织阵列,应用免疫组织化学方法检测其p53和MDM2蛋白表达,并运用统计软件SPSS11.5对两个蛋白之间的相互关系进行对应分析.结果:p53与MDM2蛋白阳性表达率分别为34.0%(16/47)和42.5%(20/47).p53蛋白与MDM2蛋白表达呈负相关(P=0.012).结论:p53突变是胃癌发生发展中重要的一步,MDM2可能在胃癌的恶性增生过程中起重要作用.     

The function of apoptosis and protein expression of bcl-2, p53 and C-myc inthe development of gastric cancer

AIM To understand the rule and possible function of apoptosis and protein expression of bcl-2, p53 and C-myc in chronic gastritis, gastric ulcer, non-classic proliferation of gastric mucosa and gastric cancer.METHODS Apoptosis was detected by using in situ terminal labelling (TUNEL). The protein expression ofbcl-2, p53 and C-myc was detected by immunohistochemical method.RESULTS The indexes of apoptosis in chronic active gastritis, gastric ulcer, mild and severe non-classicproliferation of gastric mucosa, early and progressive gastric cancer were 16.8%±12.3%, 24.1%±20.0%,19.3%±16.4%, 15.7%±15.2%, 10.1%±9.1% and 6.3%±6.0%, respectively. The index of progressivegastric cancer was lower than that of early gastric cancer and non-classic proliferation of gastric mucosa(P<0.05). The positive rate of bcl-2 protein was 9.4%, 27.6%, 52.9%, 75.0%, 83.3% and 46.7%,respectively. The positive rate of bcl-2 of early gastric cancer was higher than that of progressive gastriccancer. The positive rates of p53 protein of severe non-classic proliferation, early and progressive gastriccancer were 25.0%, 33.3% and 63.3%, respectively. The positive rate of p53 of progressive gastric cancerwas higher than that of early gastric cancer and non-classic proliferation (P<0.05). In Lauren types, theindex of apoptosis, protein expression rates of bcl-2, p53 and C-myc of intestinal type were 8.3%±7.2%,38.9%, 77.7% and 56.6%, while that of diffuse type were 5.1%±4.9%, 58.3%, 50.0% and 8.3%,respectively. All markers had statistical difference between two types (P<0.05).CONCLUSION Apoptosis was inhibited stepwise in the development of non-classic proliferation of gastricmucosa to early gastric cancer and then to progressive gastric cancer. The high expression of bcl-2, p53 andC-myc was related to the development of gastric cancer, bcl-2 might play an important role in early gastriccancer while p53 and C-myc act mostly in middle and late stage gastric cancer. The Lauren typing of gastriccancer is closely related to the index of apoptosis and expression of bcl-2, p53 and C-myc.     

p53与胃癌研究进展

p53基因突变与人类很多肿瘤有关,在正常细胞及组织中,p53蛋白的半衰期很短,浓度很低,不能用免疫组化（immunohistochemistry,IHC)法测出。相反,肿瘤中有突变体p53蛋白,其稳定性增强,量积聚,可用免疫组化法测出,一般认为,胃癌组织中p53的积聚是恶性程度高的表现,用免疫组化法测定p53,结合其它常规的检查,可用来更好地设计合理的治疗方案。     

p53、PCNA和PTEN在胃癌组织中的表达及其临床意义

目的探讨p53、PCNA和PTEN蛋白在胃癌组织中的表达及其临床意义。方法随访经手术治疗的胃癌患者,应用免疫组织化学染色方法,检测有随访资料的胃癌组织中p53、PCNA和PTEN的表达情况。结果胃癌组织中,p53阳性表达率58.2%,PCNA强阳性表达率52.7%,PTEN表达缺失率52.7%;p53、PCNA和PTEN的表达与胃癌浸润深度、有无淋巴结转移有关(P<0.05),与胃癌分化程度无关(P>0.05);胃癌患者术后5年生存率比较:p53阳性表达患者低于阴性表达患者(P<0.05),PCNA强阳性表达患者低于弱阳性表达患者(P<0.05),PTEN阳性表达患者高于阴性表达患者(P<0.05)。结论 p53、PCNA、PTEN的表达均与胃癌浸润深度、淋巴结转移显著相关;p53阳性表达、PCNA强阳性表达或PTEN阴性表达的胃癌患者具有较差的预后。检测胃癌组织中p53、PCNA和PTEN的表达情况,可作为胃癌患者预后的判定指标。     

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.     

Increased expression of p53 protein in human leukemia cells.

We examined synthesis of the cellular phosphoprotein p53 in fresh bone marrow or peripheral blood cells from normal donors and from patients with leukemia, preleukemia, or other hematopoietic disorders. Lysates of cells labeled with [35S]methionine were immunoprecipitated with monoclonal antibodies to p53, and the immunoprecipitates were analyzed by NaDodSO4/polyacrylamide gel electrophoresis and autoradiography. Bone marrow or peripheral blood cells from 8 of 33 patients with hematopoietic disorders showed increased p53, seven of the eight occurring in cells of patients with preleukemia or acute myelogenous leukemia. Increased p53 synthesis was not associated with p53 gene amplification, as shown by Southern blot analysis. Synthesis of p53 was not increased in any of nine normal human bone marrow samples or eight normal human peripheral blood granulocyte, macrophage, and lymphocyte samples. The hematopoietic cells of patients in remission or with chronic forms of leukemia did not generally synthesize elevated levels of p53. In addition, we found negligible p53 mRNA and protein expression in a variety of human myeloid leukemia lines blocked at different stages of differentiation. Southern blot analysis showed that, except for the HL-60 cells, the p53 gene of the myeloid cell lines was intact. In view of recent evidence implicating p53 in transformation of cultured cells, our results using fresh leukemia cells suggest that p53 may contribute to the phenotype of certain leukemias in vivo.