HLA antigens in colorectal tumours--low expression of HLA class I antigens in mucinous colorectal carcinomas

Expression of HLA antigens and beta 2-microglobulin was studied by immunoperoxidase staining of frozen sections of 9 mucinous and 10 nonmucinous colorectal adenocarcinomas, 1 cloacogenic carcinoma, 12 colorectal adenomas and 4 samples of normal colorectal mucosa using monoclonal antibodies (MAbs). Staining results were related to histopathological features. HLA Class I antigens were strongly expressed in morphologically normal colorectal epithelium, in all adenomas tested and in all non-mucinous carcinomas. In contrast, expression of HLA class I antigens by the majority of tumour cells was present in only 2 of the 9 mucinous carcinomas, whereas 2 of these mucinous carcinomas were completely negative. In the mucinous carcinomas a striking scarcity of mononuclear inflammatory infiltrate, especially around the mucus accumulations, was observed. HLA class II antigen expression was not detected in normal epithelium and was only focally present in 1 of the 12 adenomas. In 6 out of the 20 carcinomas tested between 20% and 90% of the tumour cells were stained by MAbs against HLA class II antigens. Apart from the low expression of HLA class I antigens in mucinous carcinomas no relationship was found between expression of HLA antigens and histological features of the tumours. The relative poor prognosis of mucinous colorectal carcinoma as reported in the literature may be associated with low expression of HLA class I antigens and scant mononuclear inflammatory infiltrate, which may be a reflection of a weak immune response to the tumour cells.     

Bcl2 expression and its correlation with neuroendocrine differentiation in colon carcinomas

AIMS AND BACKGROUND: In this study we investigated the association between BCL2 expression and neuroendocrine differentiation in tubular adenomas and colon carcinomas. We also evaluated the prognostic significance of BCL2 expression and neuroendocrine differentiation in the carcinoma group. METHODS: Forty-eight colon carcinomas and twelve tubular adenomas were stained immunohistochemically with BCL2 and chromogranin A (CgA). Staining patterns were scored semiquantitatively and correlated with tumor type, tumor grade, Dukes stage, and survival time. RESULTS: BCL2 expression was detected in 7 of 12 (58.3%) adenomas and 37 of 48 (77.0%) carcinomas. In normal mucosa we observed positive staining only in the basal portions of the crypts. However, diffuse positivity was observed in the adenomas and carcinomas. Carcinomas had significantly higher BCL2 scores than the normal group, but we did not observe any significant differences either between the adenoma and carcinoma group or between the adenoma and normal group. BCL2 scores were higher in stage B than in stage C tumors, and in adenocarcinomas than in mucinous carcinomas. CgA positivity was observed in 24 of 48 (50%) carcinomas. It was not detected in adenomas. We did not find a significant correlation between CgA expression and any of the clinicopathological parameters. CONCLUSION: On consecutive sections BCL2 and CgA positivity closely paralleled each other and a significant positive correlation was observed between CgA and BCL2 expression. These findings suggest a close association between BCL2 expression and neuroendocrine differentiation and indicate that BCL2 may be involved in neuroendocrine differentiation in addition to its role in protecting cells from apoptosis.     

Immunohistochemical detection of p53 and Bcl-2 in colorectal carcinoma: no evidence for prognostic significance.

To evaluate the prognostic significance of immunohistochemically detected p53 and Bcl-2 proteins in colorectal cancer, tissue sections from 238 paraffin-embedded colorectal carcinomas were immunostained for p53 (MAb DO-7 and CM-1 antiserum) and Bcl-2 (MAb Bcl-2:124). Staining patterns were assessed semiquantitatively and correlated with each other and with sex, age, tumour site, Dukes'' classification, tumour differentiation, mucinous characteristics, lymphocyte and eosinophilic granulocyte infiltration, and patient survival. In our series, 35% of carcinomas showed no nuclear staining and 34% (DO-7) to 40% (CM-1) showed staining in over 30% of tumour cell nuclei. A majority of carcinomas that had been immunostained with CM-1 showed cytoplasmic staining, but this was not observed with DO-7. With respect to Bcl-2, 51% of tumours were completely negative, 32% displayed weak and 15% moderate staining; only 3% showed strong positive staining. No evidence was found for reciprocity between Bcl-2 expression and nuclear p53 accumulation. From 13 cases containing tumour-associated adenoma, four were Bcl-2 negative in premalignant and malignant cells, in another four cases these cells showed similar staining intensities and in the remaining cases only the malignant colorectal cells were Bcl-2 negative. Therefore, our data indicate that Bcl-2 is dispensable in the progression towards carcinoma. Except for an association between nuclear p53 accumulation and mucinous tumours (P = 0.01), no significant correlation was found between the clinicopathological parameters mentioned above and immunostaining pattern of (nuclear or cytoplasmic) p53 or Bcl-2.     

Correlation of bcl-2 oncoprotein immunohistochemical expression with proliferation index and histopathologic parameters in colorectal neoplasia

Thebcl-2oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18), and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly valuated by MIB1, a monoclonal antibody to Ki67 proliferation antigen. Immuno-histochemical (IHC) staining expression of bcl-2 and Ki67 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas according to the avidin-biotin-complex method. The aim of the study was twofold: 1) to investigate any correlation between MIB1 and bcl-2 immunostaining expression in colonic adenomas and carcinomas, 2) to identify any relationship between either marker and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angio-lymphatic invasion, tumor grade and differentiation in colon carcinomas. Bcl-2 was consistently higher in adenomas than in carcinomas. There were 44/56 (78.6%) adenomas, and 27/52 (51.9%) carcinomas positive for bcl-2 (p=0.004).The mean Ki67 labeling index (LI) was 30.05+/-7.6 and 38.12+/-11.01 in adenomas and carcinomas, respectively (p=0.0001). Expression of bcl-2 in carcinoma was significantly associated with a lower mean Ki67 LI and with favorable histopathologic parameters. We conclude that bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with a favorable clinical course. Furthermore, an inverse relationship exists between bcl-2 and Ki67 in colonic neoplasia. Evaluation of bcl-2 and Ki67 IHC expression in colonic carcinoma should be performed prospectively to determine if their expression is of value in predicting the clinical course in these patients.     

Quantification of MET and hepatocyte growth factor/scatter factor expression in colorectal adenomas, carcinomas and non-neoplastic epithelia by quantitative laser scanning microscopy

Hepatocyte growth factor (HGF)-MET signalling in cancer biology has been well characterized in multiple organ systems. Numerous investigations have described an up-regulation of c-met mRNA in human colorectal adenomas and carcinomas. However, a quantitative immunohistochemical analysis of MET and HGF protein levels in tumor tissues has not been reported previously. Formalin-fixed and paraffin-embedded tissues from 41 colorectal adenomas and 49 colorectal carcinomas were characterized by immunofluorescent staining using HGF- and MET-specific antibodies. The immunoreactivity was evaluated by confocal laser scanning microscopy, computer-based image analysis and appropriate statistical tests. Normal colorectal mucosa, adenomas and carcinomas exhibited comparable levels of MET and HGF proteins. MET expression in carcinomas, although statistically not significant, demonstrated a tendency to correlate with the grade of differentiation. Correlations of MET and HGF with other clinico-pathological variables including the extent of the mucinous component and the pTNM stage were not observed. The ratio of HGF in carcinoma vs. non-neoplastic tissue was significantly different between high and low carcinoma stage. Alterations of absolute levels of MET and HGF protein during the colorectal adenoma-carcinoma sequence were not significant. The presumed role of MET-HGF interactions in large bowel carcinogenesis may therefore be a result of or depend upon other regulatory factors involved in MET-mediated signalling pathways.     

热休克蛋白10在大肠癌的表达及其临床病理意义

目的研究热休克蛋白10(heat shock protein 10,HSP10)在大肠癌发生、发展过程中的表达规律,了解其与大肠癌临床病理特征和术后生存期的关系。方法应用免疫组化EnVision二步法,检测HSP10在大肠正常黏膜、腺瘤和腺癌中的表达,及其与临床病理表现和术后生存期的相关性。结果HSP10在大肠正常黏膜、腺瘤和腺癌中均有表达,在腺瘤、腺癌中的表达明显强于正常黏膜(P<0.001);HSP10的阳性表达与大肠癌患者的年龄、性别、肿瘤浸润深度、局部淋巴结转移、远处转移、临床分期、组织学分化程度等临床病理特征和术后生存期均无关。结论HSP10在大肠腺瘤和腺癌的高表达,提示可能与大肠癌的发生发展有关;HSP10的阳性表达与大肠癌的临床病理特征和术后生存期无关。     

环氧合酶-2在大肠癌中的表达及其与预后的关系

目的探讨环氧合酶-2（COX-2）在大肠癌组织中的表达及其意义。方法应用S-P免疫组化法检测40例大肠癌石蜡标本、20例正常大肠组织中COX-2的表达。结果COX-2蛋自在40例大肠癌组织中高表达（36／40）,阳性表达率90％,与正常大肠组织相比差异非常显著（P〈0．01）;COX．2蛋白的表达与Dukes分期呈正相关（P〈0．05）;淋巴结有转移组与无转移组也有显著性差异（P〈0．05）。结论COX-2在大肠癌的发生及转移过程中发挥着重要作用,可作为预测大肠癌预后的临床指标之一。     

热休克蛋白10在大肠癌的表达及其临床病理意义

Objective： To investigate the expression of heat shock protein 10 （HSPIO） during genesis and development of large bowel carcinoma and discuss the clinical significance about its expression. Methods： The expression of HSPIO was observed in specimens from normal colonic mucosa （NC）, colorectal adenomas （CA） and colorectal adenocarcinomas （CAC） by immunohistochemistry EnVisionTM. Its correlations to clinicopathologic features, as well as to postoperative survival time of large bowel carcinoma patients were analyzed. Results： The expression of HSPIO was common in normal colonic mucosa, colorectal adenomas and adenocarcinomas and more intensive in colorectal adenomas and adenocarcinomas than that in normal colonic mucosa （P 〈 0.001）. The positive expression of HSPIO had no correlation to clinicopathologic features, including age, gender, primary tumor, infiltrating of regional lymph node, metastasis, clinical stage and histopathology of large bowel carcinoma patients, as well as to their postoperative survival time. Conclusion： HSPIO was overexpressed in the early stage of colorectal adenocarcinoma suggesting that it could serve as an index for early diagnosis of large bowl carcinoma. The positive expression of HSPIO had no correlation to clinicopathologic features or postoperative survival time of large bowel carcinoma patients.     

Correlation of Skp2 with carcinogenesis, invasion, metastasis, and prognosis in colorectal tumors

In colorectal tumors, S-phase kinase-associated protein 2 (Skp2) still has numerous important questions unanswered: its expression in adenomas, its correlation with key clinicopathological indices, its association with patient prognosis, its variation in lymph node metastases, and its association with many cell-cycle regulators. To answer these questions in colorectal tumors, Skp2, cyclin A, cyclin B1, cyclin E, CDK2, and Ki67 were immunohistochemically stained in 12 normal mucosa, 36 adenomas, 11 carcinomas in adenomas, 102 primary carcinomas, and 12 paired lymph node metastases; and Skp2 was examined by Western blot in 8 pairs of normal mucosa and carcinomas. Situated in nuclei, Skp2 expression significantly increased from normal mucosa through adenoma to primary carcinoma (p<0.0001), from mild through moderate to severe dysplasia in adenomas (p=0.038), from peripheral adenoma to paired central carcinoma (p=0.0033), and from primary carcinoma to lymph node metastasis (p=0.015), and these increases were confirmed by Western blot. Expression, however, relatively declined significantly in the primary carcinomas showing deep invasion (p=0.0113), lymph nodal metastases (p=0.0268), and poor prognosis for all (p=0.0104) or stage III patients (p=0.0119). High Skp2 was also significantly linked with elevated cyclin A, cyclin B1, cyclin E, CDK2 (in primary carcinomas only), and Ki67 in both adenomas and primary carcinomas. Thus, overexpression of Skp2 is associated with colorectal carcinogenesis and late metastasis to lymph nodes, whereas relative reduction of Skp2 is correlated with local invasion of primary carcinoma.     

Cyclin B1, unlike cyclin G1, increases significantly during colorectal carcinogenesis and during later metastasis to lymph nodes

In collaboration with p53, cyclins B1 and G1 regulate the G2/M transition, a key checkpoint in the active cell cycle, which can be monitored by Ki67. However, the cyclin B1 expression remains unclear during colorectal carcinogenesis and during later metastasis to lymph nodes, and cyclin G1 expression is not clear in colorectal tumors. To clarify the variations of the two cyclins in colorectal tumors, cyclin B1, cyclin G1, p53, and Ki67 were immunohistochemically stained in 22 normal mucosa, 62 adenomas, 17 carcinomas in adenomas, 194 primary carcinomas, and 21 lymph node metastases; and the two cyclins were examined by Western blot in other 10 pairs of normal mucosa and primary carcinomas. Located in cytoplasms, nuclei or both, cyclin B1 expression increased significantly from normal mucosa through adenomas to primary carcinomas, from adenomas with mild dysplasia through those with moderate to those with severe, from peripheral adenomas to their central carcinomas, and from primary to metastatic foci. These increased expressions were confirmed by Western blot. Cyclin B1 expression, however, declined significantly in primary carcinomas showing large size, mucinous type, deep invasion, or short postoperative-patient-survival time. High cyclin B1 was linked to high p53 in adenomas, and to high Ki67 in adenomas and primary carcinomas. In contrast, found limited to nuclei, cyclin G1 expression did not vary significantly from normal mucosa through to metastatic carcinomas, and was not associated with clinicopathological parameters, p53 or Ki67. The unchanged expressions were confirmed by Western blot. Thus, increased cyclin B1, but not cyclin G1, may promote colorectal carcinogenesis and later metastasis to lymph nodes.     

大肠肿瘤中bcl—2及PCNA表达及其意义

目的：研究ｂｃｌ－２及ＰＣＮＡ在大肠肿瘤肆生中的作用及其临床意义。方法：应用免疫组化Ｓ－Ｐ法分别检测大肠正常粘膜、腺瘤及腺癌中ｂｃ；－２及ＰＣＮＡ表达。结果：Ｂｃｌ－２在正常粘膜基底部上皮细胞表达，在腺瘤（７７．５％）和腺癌中（５６．３％）ｂｃｌ－２表达差异显（Ｐ〈０．０５）。高分化腺癌ｂｃｌ－２表达率（６８．４％）显高于差分化腺癌（４１．７％），ＰＣＮＡ表达在正常粘膜，腺瘤及腺癌中依次递增，     

Evaluation of the secretory component as a prognostic variable in colorectal carcinoma

Expression of the secretory component (SC) of IgA was investigated in normal colonic mucosa, in adenomas and in 188 colon carcinomas. Of the carcinoma patients, 149 underwent potentially curative surgical treatment. In particular, it was of interest to determine whether pathohistological or clinical parameters showed any association with the mode of SC expression in carcinomas. Irrespective of anatomical site, normal colon mucosa was generally SC-positive. Normal epithelium, however, displayed microheterogeneity in SC content, which was related to columnar and goblet-cell type and micro-topographical site, implying a subtle regulatory mechanism. In contrast to adenomas, which were evenly SC-positive and showed focally weak SC expression in only 2 out of 20 cases, carcinomas were rather heterogeneous in their SC-expression pattern. In all, 48 carcinomas were entirely positive, 48 were completely negative and the remaining 92 showed various patterns of heterogeneous SC expression. The mode of SC expression was correlated with tumor staging, i.e., complete absence of SC was more often found in Dukes' C and D groups. In addition, the presence of SC in carcinomas was statistically correlated with the mucinous type. The mode of SC expression was not correlated with tumor grading and tumor location. The rate of disease-free survival and the risk of tumor-related death revealed a significant correlation with the mode of SC expression when patients who had received potentially curative or non-curative treatment were included in the log-rank test. Absence or low levels of SC expression were more frequent in the group that suffered a tumor relapse than in the recurrence-free cohort. Tumor-related death was more frequent when primaries were characterized by absence or low levels of SC expression. We conclude that absence or low levels of SC expression are an unfavorable prognostic variable in colorectal carcinoma. © 1994 Wiley-Liss, Inc.     

CD44V6在结直肠癌组织中的表达及临床意义

目的：探讨CD44V6表达与结直肠癌发生、发展及转移的关系。方法：采用S－P免疫组织化学方法，检测78例原发性结直肠腺癌、14例结直肠腺瘤癌变、57例结直肠腺瘤、30例结直肠增生性息肉和24例结直肠正常黏膜中CD44V6的表达情况。结果：腺瘤、腺瘤癌变和腺癌组织中CD44V6阳性表达率分别为78．95％、100．00％和56．41％，明显高于增生性息肉和正常黏膜组织的阳性表达率（14．81％）。CD44V6阳性表达与腺癌淋巴结转移、Dukes分期和病理分级无相关性。结论：CD44V6表达与结直肠癌的发生有关，可作为诊断结直肠癌前病变和早期癌的生物学指标。     

Expression of MUC2-mucin in colorectal adenomas and carcinomas of different histological types

The expression of mucin MUC2 was investigated in normal colonic tissue, in colonic adenomas and in carcinomas of the mucinous and non-mucinous type. The latter were subdivided into carcinomas originating from the adenoma-carcinoma sequence (ACS) and de novo (DN) carcinomas. The expression was assayed by immunohistochemistry with the monoclonal anti-MUC2 antibody CCP58 and by mRNA semiquantitation. MUC2 protein epitope CCP58 was strongly expressed in 21 % of normal colonic tissues, in 40% of villous and in 48% of tubular adenomas. Mucinous carcinomas exhibited strong expression in 72%, ACS carcinomas in 21 % and DN adenocarcinomas in none of the tumors investigated. Compared with the adjacent non malignant tissue (transitional mucosa), CCP58 epitope expression in the tumor was higher in 74% of mucinous carcinomas, but equal or lower in 69% of ACS carcinomas and in 100% of de novo carcinomas. The alterations of MUC2 expression detected by immunohistochemistry in adenocarcinomas were confirmed on mRNA level. These data indicate that the MUC2 expression pattern is different in the 3 carcinoma types investigated. MUC2 over-expression occurs in the adenomatous tissue. It is always maintained in mucinous carcinomas, but frequently decreased in non-mucinous ACS carcinomas. DN carcinomas are most frequently associated with decreased expression of MUC2. © 1994 Wiley-Liss, Inc.     

c-erbB-2、ras、p53基因产物在大肠癌及癌前病变中的表达

目的：探讨c－erbB－2、ras、p53基因的表达与大肠癌发生发展的关系以及其对大肠癌早期诊断、预后判断的价值。方法：对45例大肠癌及36例癌旁非腺瘤型不典型增生、17例大肠腺瘤，用免疫组化方法检测基因产物的表达。结果：p53在大肠癌的阳性表达率为57．8％，p53蛋白高表达的癌旁非腺瘤型不典型增生及大肠腺瘤均为中度或高度不典型增生。p53蛋白表达与大肠癌的组织分化程度、淋巴结转移有关（P＜0．05）。p21、p185蛋白表达与大肠癌组织学分型、癌组织浸润程度、淋巴结转移无关，而与癌组织分化程度有关（P＜0．05）。结论：p53蛋白表达可能是大肠病变恶性倾向的一个独立标志。p53、p21、p185蛋白对大肠癌的发生、发展起重要作用。     

EphA2蛋白表达与结直肠癌浸润性及微血管生成的关系

目的：探讨酪氨酸蛋白激酶受体EphA2表达与大肠癌浸润及其与大肠癌微血管生成之间的关系。方法：应用免疫组化方法检测70例大肠癌标本和相应正常大肠黏膜组织中EphA2蛋白的表达情况,分析E-phA2表达与大肠癌临床病理学因素及微血管生成之间的关系。结果：EphA2蛋白在癌组织中的表达明显高于相应正常大肠黏膜组织（P〈0.001）。EphA2蛋白高表达与癌分化程度、生长方式、浸润深度和肿瘤体积相关（P〈0.05）,而与患者的年龄、性别、淋巴结和血行性转移无关（P〉0.05）。免疫组化结果还发现,肿瘤组织内微血管内皮细胞也有EphA2受体蛋白表达。CD34染色后大肠癌的微血管密度（microvessel density,MVD）与EphA2表达水平有显著相关,EphA2阳性表达强度高的肿瘤区域有较高的微血管密度。结论：E-phA2蛋白的高表达与大肠癌的发生和浸润有关。     

Increased expression of cyclooxygenase-2 in human pancreatic neoplasms and potential for chemoprevention by cyclooxygenase inhibitors

BACKGROUND: Cyclooxygenase-2 (COX-2) is thought to be linked to carcinogenesis; however, very little is known about its expression in pancreatic neoplasms. The authors studied the expression of COX-2 in human pancreatic neoplasms and investigated the effect of COX inhibitors on the growth of human pancreatic carcinoma cells. METHODS: Expression of COX-2 protein was immunohistochemically examined in 42 human pancreatic duct cell carcinomas (PDCs) and in 29 intraductal papillary mucinous tumors (IPMTs [adenomas, 19; carcinomas, 10]) of the pancreas that were resected surgically at the National Cancer Center Hospital in Tokyo. The growth of four human pancreatic carcinoma cell lines also was evaluated in the presence of COX inhibitors. RESULTS: Marked COX-2 expression was observed in 57% (24 of 42) of PDCs, in 58% (11 of 19) of adenomas, and in 70% (7 of 10) of adenocarcinomas of IPMTs. However, there was no correlation between COX-2 expression and clinicopathologic indices of the patients. All four pancreatic cancer cell lines expressed COX-2 protein weakly or strongly, and the inhibitory effect of aspirin on cell growth was correlated with the expression of COX-2. CONCLUSIONS: COX-2 was expressed in adenomas of IPMTs as well as in carcinomas and might have played a role in the development of pancreatic tumors. In this study, COX inhibitors, as nonsteroidal anti-inflammatory drugs, were shown to be possible preventive agents against pancreatic neoplasms.     

Significance of immunohistochemical c-ErbB-2 product localisation pattern for prognosis in human breast cancer

Breast cancer is an increasingly important cause of illness and death among women. In recent years several novel prognostic determinants of breast cancer have been identified, including c-ErbB-2. In this study, expression of c-ErbB-2 in breast carcinoma was correlated with axillary lymph node metastases and disease outcome. The expression of c-ErbB-2 oncoprotein was analysed in 315 tumor specimens of infiltrating ductal carcinoma of breast. They were categorized according to the modified Bloom and Richardson criteria into three histological grades. These patients also had axillary lymph nodes sampling. The expression of c-ErbB-2 oncoprotein was analysed immunohistochemically. Over expression of c-ErbB-2 were observed in 39.36% tumors. Axillary lymph node metastasis had significant correlation with intensified positivity of c-ErbB-2. C-ErbB-2 positive patients did show resistance to chemotherapy when compared for recurrence and distant metastases following surgery (p< 0.05). At a median follow-up of 48 months in c-ErbB-2 positive patients, the overall survival was 3.0 years and disease free survival was 2.5 years. c-ErbB-2 negative tumor patients showed a far better survival. In this group the overall survival was 4.44 years and the disease free survival was 3.78 years. These findings reinforce the view that c-ErbB-2 immunohistochemical detection is of help in detecting a subgroup of breast carcinoma patients who are at high risk. This may also be of particular relevance in decisions regarding adjuvant chemotherapy to these patients.     

大肠癌组织中Bcl-2表达与临床病理参数相关性的研究

目的：探讨抑制凋亡基因Bcl-2在大肠癌及癌旁组织中的表达及意义。方法：应用免疫组化S-P法检测72例大肠癌组织和48例癌旁组织中Bcl-2的表达情况。结果：Bcl-2在癌组织与癌旁组织的表达率分别是54．17％（39／72）和20．83％（10／48），二者差异有统计学意义，P〈0.001。Bcl-2在高、中和低分化腺癌组织中表达分别是66．67％、47．06％和35．71％，统计学分析高、低分化腺癌之间差异有统计学意义，P=0．016。大肠癌组织Bcl-2表达与年龄、性别和瘤体大体分型等临床病理参数无关，P〉0．05。在伴有淋巴结转移癌组织中Bel-2表达率为34．78％，无淋巴结转移者为63．27％，统计学分析差异有统计学意义，P-0．024。DukeD期Bcl-2表达率显著低于A、B、C期，P〈0．05。结论：Bcl-2蛋白参与了大肠癌的发生，其表达高低与肿瘤细胞的病理分级、Duke临床分期和淋巴结转移密切相关。