RhoGDI2蛋白的高表达与结直肠癌侵袭和转移的相关性分析

目的通过检测RhoGTP酶解离抑制因子2（RhoGTPase dissociation inhibitor 2,RhoGDI2）在结直肠癌和癌旁组织中的表达并结合临床病理特点进行分析,探讨RhoGDI2的蛋白表达水平与结直肠癌侵袭转移的关系及在肿瘤发生发展中的作用。 方法选取山东省医学科学院附属医院2012年07月至2014年07月采取手术切除的153例结直肠癌病例,采用免疫组织化学检测153例肿瘤组织标本和癌旁标本中RhoGDI2蛋白的表达水平。 结果RhoGDI2蛋白在结肠癌组织中呈阳性表达,且主要在胞浆中表达;但在癌旁正常组织中无阳性表达（57.5% vs 0.00%）。结直肠癌组织中RhoGDI2蛋白的表达在低分化组显著高于高中分化组（χ²=2.090,P<0.05）。RhoGDI2的阳性表达与结直肠肿瘤的大小呈正相关,肿瘤越大阳性表达率越高（χ²=4.293,P<0.05）,并随着肿瘤浸润深度阳性表达率增加（χ²=1.711,P<0.05）,其在有淋巴结转移者表达显著高于无淋巴结转移者（χ²=5.925,P<0.05）、有远处转移者显著高于无远处转移者（χ²=5.519,P<0.05）,并且与临床分期密切相关,分期较晚的显著高于分期较早的（χ²=5.683,P<0.05）。RhoGDI2在结直肠癌中的阳性表达与年龄（<60 years vs ≥60 years）（χ²=0.054,P>0.05）,性别（χ²=0.037,P>0.05）无相关性。 结论RhoGDI2在结直肠癌中高表达,并且与结直肠癌的局部侵袭和远处转移呈正相关。RhoGDI2可能在结直肠的发生发展和侵袭转移过程中起着重要的作用。     

Overexpression of cyclooxygenase-2 in non-small cell lung cancer

Evidence is accumulating to suggest that the inducible isoenzyme of cyclooxygenase (COX)-2 is up-regulated in human cancers and epidemiological studies indicate that COX inhibitors may have a protective effect on the development of lung cancer. We used immunohistochemistry and Western blotting to investigate COX expression in lung tumour specimens and three lung cancer cell lines. Sixty-five archival lung tissue samples, including 46 squamous cell and 6 adenocarcinoma lung resections, and 13 small cell lung cancer (SCLC) biopsies were studied. Dense and intense cytoplasmic COX-2 staining was found in all 52 resections from non-small cell lung cancer (NSCLC). The staining was diffuse and much stronger than adjacent respiratory epithelium. COX-2 staining was relatively weak in the majority of the SCLC samples. The bronchial and bronchiolar epithelium in the surrounding normal lung structures showed uniform COX immunoreactivity with apical concentration of the stain. There was no increase in COX-1 staining in any tumour type. Western blot analysis of the cancer lines revealed significantly higher expression of COX-1 in CORL23 line and COX-2 in two NSCLC cell lines (MOR/P; A549) compared with the expression of COX-1 and COX-2 in cultured normal bronchial epithelial cells. Our findings demonstrated COX-2 overexpression in NSCLC.     

Progastrin and cyclooxygenase-2 in colorectal cancer

Colorectal cancers (CRCs) are one of the most common forms of cancer in Poland and one of the leading causes of death. The tumors have been attributed to genetic, dietary, and other environmental factors, but recently growth factors such as gastrin have also been implicated in the carcinogenesis. The relationship between plasma amidated and nonamidated gastrin in CRCs is controversial. This study was designed (1) to determine the plasma levels of progastrin and amidated gastrin in 50 CRC patients before and 3–6 months after removal of the tumor, (2) to determine the tumor concentrations of these gastrin peptides and the level of expression for gastrin mRNA and gastrin/CCK_B receptor mRNA, (3) to examine the expression of cyclooxygenase COX-1 and COX-2 mRNA in CRC tissue, and (4) to compare the prevalence of Hp and its cytotoxic protein, CagA, and cytokines (TNF, IL-1, and IL-8) in CRCs, before and after removal of tumor. It was found that the CRC, its resection margin, and the plasma contained severalfold higher levels of progastrin than of amidated gastrins and that the removal of the CRC tumor resulted in a marked reduction in plasma progastrin level without a significant alteration in plasma levels of amidated gastrins. Both gastrin and CCK_B-R mRNA were detected in the cancer tissue and resection margin by RT-PCR, and similarly, COX-1 and COX-2 mRNA were expressed in these tissues of most CRCs. The seroprevalence of Hp, especially that expressing CagA, and levels of IL-1, but not other cytokines, were significantly higher in CRC patients than in 100 age-, gender-, and profession-matched controls and did not change significantly about 3–6 months after tumor resection. We conclude that (1) the CRC and its margin contain large amounts of progastrin and show gene expression of gastrin, CCK_B-R, and COX-2; (2) removal of the CRC markedly reduces the plasma concentrations of progastrin; (3) the Hp infection rate is higher in CRC, and this may contribute to colorectal cancerogenesis via enhancement of progastrin and gastrin release; and (4) plasma progastrin concentrations might serve as a biomarker of CRC.     

Overexpression of Lgr5 correlates with resistance to 5-FU-based chemotherapy in colorectal cancer

Background

The leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) is an adult intestinal stem cell marker frequently detected in human colorectal cancers (CRCs). However, the value of Lgr5 level in CRC prognosis and treatment prediction has not been well characterized.

Methods

We examined Lgr5 expression in 384 formalin-fixed paraffin-embedded CRC specimens from 296 CRC patients, including 64 patients treated with 5-fluorouracil (5-FU)-based chemotherapy. The effects of Lgr5 on cell proliferation, survival, and drug resistance were examined in cultured CRC cells.

Results

Elevated expression of Lgr5 was observed in CRC tissues, and Lgr5 protein levels were significantly correlated with an advanced American Joint Committee on Cancer stage (P?<?0.001), T stage (P?<?0.001), N stage (P?<?0.001), and distant metastasis (P?<?0.001). High expression levels of Lgr5 were significantly associated with shorter disease-free survival (P?<?0.001) and shorter cancer-specific survival (P?=?0.007) in CRC patients. Among the chemotherapy-treated subgroups, patients with low Lgr5 level showed a better response rate (65 %) than patients with high Lgr5 level (37 %) towards 5-FU-based treatment (P?=?0.025). In cultured CRC cell lines, knocking down Lgr5 suppressed cell proliferation and colony formation ability, while it enhanced apoptosis and rendered cells more sensitive to chemotherapeutic agents. In contrast, overexpression of Lgr5 increased cell proliferation and enhanced chemoresistance.

Conclusion

These results suggest that elevated Lgr5 level is associated with CRC progression and treatment response and has the potential to serve as a therapeutic target in CRC patients.     

Overexpression of cyclooxygenase-2 and tumor angiogenesis in human gastric cancer

BACKGROUND/AIMS: Cyclooxygenase-2 (COX-2) protein is overexpressed in various cancers, including esophageal, gastric, colon, and pancreatic. To better comprehend the role of COX-2 in gastric cancer, especially with regard to angiogenesis, we investigated COX-2 and vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) in 108 patients with gastric cancer. METHODOLOGY: We used immunohistochemical analysis of formalin-fixed tissues of gastric cancer. RESULTS: Expression of COX-2 showed diffuse staining in the cytoplasm of tumor cells, however, no staining in normal epithelial cells. Of the 108 tumors examined, 71 (65%) were positive for COX-2 expression, the VEGF-positive cases numbered 43 of 108 cases (39.8%). The intensity of COX-2 expression did not correlate with any clinicopathological characteristics. The positive rate of VEGF expression in COX-2-positive cases was significantly higher than in COX-2-negative ones (47.9% vs. 24.3%, P<0.05). MVD in COX-2-positive cases was significantly higher than in COX-2-negative ones (22.0+/-7.8 vs. 18.5+/-7.5/1 mm2; P<0.05). CONCLUSIONS: Our study provides evidence that COX-2 is closely related with angiogenesis.     

COX-2基因多态性与结直肠癌发病风险的关系研究

目的 探讨环氧合酶-2(COX-2)-765G＞C、-1195G＞A、8473T＞C基因多态性与结直肠癌(CRC)遗传易感性的关系,同时评估COX-2基因多态性与某些因素共同作用对CRC发病风险的影响.方法 采用病例对照研究方法,入选CRC患者130例及健康非肿瘤人群120例.PCR-RFLP方法检测病例组和对照组COX-2基因的3个多态基因型,结果采用非条件logistic回归分析,用比值比(OR)及95％可信区间(CI)评估研究因素对疾病危险度的作用.结果 病例组COX-2-765G＞C、-1195G＞A、8473T＞C基因型频率与对照组间的差异均无统计学意义.根据体重指数(BMI)将研究对象分层后,发现-765GG基因型与CRC发病风险的相关性具有统计学意义,与正常BMI(＜23)相比,携带-765GG基因型且超重或肥胖者(BMI≥23)患CRC风险增高(OR=2.024,95％CI:1.089～3.760,P=0.024).此外,还发现吸烟可增加患CRC的风险,与不吸烟人群相比,吸烟人群中的8473TT基因型携带者患CRC的风险明显增高(OR=1.938,95％CI:1.021～3.677,P=0.042).结论 虽然COX-2 765G＞C、-1195G＞A、8473T＞C基因多态性与CRC遗传易感性之间没有相关性,但是携带-765GG基因型的高BMI人群或携带8473TT基因型的吸烟人群的CRC发生风险显著增高.对COX-2基因多态性位点的检测将有助于预防CRC的发生.     

Role of cyclooxygenase-2 in the angiogenesis of colorectal cancer

BACKGROUND: Cyclooxygenase (COX) is the rate-limiting enzyme in the synthesis of prostaglandins. It exists in two isoforms: COX-1 which is constitutively expressed and COX-2 which is an inducible form activated by a variety of cytokines during inflammation. DISCUSSION: Interest in this enzyme arose in the early 1990s when, following epidemiological studies, aspirin (which is a COX inhibitor) was found to reduce the risk of colorectal cancer. Since then various studies to decipher the mechanisms by which COX reduces the development of colorectal cancer have been undertaken. One of the mechanisms being studied is its role in the angiogenesis of colorectal cancer. Angiogenesis of its own has been well established as a key factor in the development of tumours. Agents that specifically inhibit COX-2 are now in clinical development and have been licensed to be used in patients with familial adenomatosis polyposis. CONCLUSION: What needs to be determined is whether the antiangiogenic effects of COX-2 inhibitors can be used in the prevention and/or treatment of colorectal cancer and its metastases.     

Role of cyclooxygenase-2 in pathogenesis and prevention of colorectal cancer

Chemoprevention of colorectal cancer is a promising science that has particular importance due to the limited success of current treatments for most advanced common malignancies. Many chemopreventive agents have been studied including cyclooxygenase (COX) inhibitors. Two isoforms of the COX enzymes are COX-1 and COX-2. COX-1 is constitutively expressed in normal tissue, serving an important role in tissue homeostasis, whereas COX-2 is an inducible enzyme, which is markedly overexpressed at sites of inflammation and colorectal neoplasms. The preventive efficacy of traditional nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit COX-1 and/or COX-2, has considerable support from animal and epidemiological studies; however, there are well-documented toxicities associated with NSAID use. These adverse effects are attributed to NSAIDs' inhibition of COX-1. The development of COX-2 specific inhibitors gave hopes of bypassing the associated traditional NSAID toxicities while better targeting tissues sustaining inflammation and neoplasia. The PrsSAP, APC and APPROVe trials demonstrated the efficacy of COX-2 specific inhibitors in preventing the recurrence of sporadic colorectal polyps. However, the trials were terminated early due to discovery of significant cardiovascular toxicity, although the exact extent of this toxicity remains unclear. The exact mechanisms through which NSAIDs exert their cancer preventing effects are currently unknown; inhibition of COX-2 is of great importance, but COX-2 independent pathways exist as well. In addition, the efficacy of NSAID use for cancer prevention can differ significantly between individuals. Personalized medicine in this field is also greatly anticipated. Combination therapy is under extensive research in order to improve efficacy while reducing toxicity profiles. Chemoprevention of colorectal cancer is largely possible, but the ultimate drug and proper patient selection, among other elements of the cancer prevention equation, are still needed.     

Expression of cyclooxygenase-2 in colorectal cancer and its clinical significance

AIM: To clarify the clinicopathologic significance of COX-2 expression in human colorectal cancer. METHODS: A total of 128 surgically resected colorectal cancer specimens were immunohistochemically analyzed with the use of anti-COX-2, anti-VEGF and anti-MMP-2 antibodies. The relationship between the cyclooxygenase-2 expression in primary lesions of colorectal cancer and clinicopathoiogic parameters was evaluated by chi-square test. RESULTS: Among 128 cases of colorectal cancer, 87 (67.9%) were positive for cyclooxygenase-2. The expression of cyclooxygenase-2 was significantly correlated with the depth of invasion, stage of disease, and metastasis (lymph node and liver). Patients in T3-T4, stages Ⅲ-Ⅳand with metastasis had much higher expression of cyclooxygenase-2 than ones in T1-T2, stages Ⅰ-Ⅱ and without metastasis (P<0.05). Among 45 cases of colorectal cancer with lymph node metastasis, the COX-2-positive rate was 86.7% (39/45) for primary lesions and diffuse cytoplasmic staining for COX-2 protein was detected in cancer cells in 100% of metastatic lesions of the lymph nodes. VEGF expression was detected in 49 tumors (38.3%), and VEGF expression was closely correlated with COX-2 expression. The positive expression rate of VEGF (81.6%) in the cyclooxygenase-2-positive group was higher than that in the cyclooxygenase-2-negative group (18.4%, P<0.05). MMP-2 expression was detected in 88 tumors (68.8%), and MMP-2 expression was closely correlated with COX-2 expression. The positive expression rate of MMP-2 (79.6%) in the positive COX-2 group was higher than that in the negative COX-2 group (20.4%, P<0.05). CONCLUSION: Cyclooxygenase-2 may be associated with tumor progression by modulating the angiogenesis and cancer cell motility and invasive potential in colorectal cancer and it can be used as a possible biomarker.     

Loss of Bcl-2 expression correlates with tumour recurrence in colorectal cancer

Aims—To investigate the associationbetween immunohistochemical expression of Bcl-2 and p53 in colorectalcancer and tumour recurrence following surgery.
Methods—Sixty six cases of Dukes'B colorectal carcinoma were studied. All tumours were moderatelydifferentiated and were shown to be histologically clear of theresection margins. Immunohistochemistry was performed on formalin fixedparaffin wax embedded tissue using monoclonal antibodies for p53 andBcl-2. The Bcl-2 staining was assessed separately for relativeintensity of staining and percentage of positive tumour cells and givena final score which combined the two factors. The p53 staining wasassessed on number of positive tumour cells only. The patterns ofimmunostaining of those cases in which there had been tumour recurrencewere compared with those cases in which there was no tumour recurrence (controls).
Results—A statistically significantinverse association was found between Bcl-2 score and tumour recurrence(median Bcl-2 score of 6 (interquartile range (IQR) 2-9) in patientswith recurrent disease; median Bcl-2 score of 8 (IQR 6-10) in thosewithout recurrence; p=0.03). When examined separately, both theintensity of expression and percentage of positive tumour cells weresignificantly associated with tumour recurrence (p=0.04 in each case).There was no association between p53 staining and tumour recurrence.
Conclusion—Results suggest that,when controlled for differentiation, Bcl-2 expression is a prognosticmarker and may be useful as an adjunctive test in clinical decision making.

Keywords:colorectal cancer; tumour recurrence; Bcl-2; p53; Jass grouping

     

环氧合酶-2抑制剂吡罗昔康对结肠癌细胞生长的影响

目的观察非甾体类抗炎药、环氧合酶(COX)-2抑制剂吡罗昔康(Piroxicam)对结肠癌细胞的影响，并结合COX-2蛋白表达和细胞凋亡情况探讨结肠癌的预防。方法细胞株选用SW1116结肠腺癌细胞；细胞增殖实验时，用MTT法测定细胞增殖活性；用免疫组化及Western Blot方法检测细胞内COX-2蛋白表达；用DNA云梯电泳法检测细胞凋亡。结果吡罗昔康能够抑制结肠腺癌细胞的增殖，其效应与浓度呈正相关；浓度≥1．0mmol／L时呈现细胞毒作用。吡罗昔康作用12h即可显著抑制COX-2蛋白的表达；作用24h后，蛋白水平恢复程度与浓度成负相关。吡罗昔康浓度≥0．1mmol／L时可以诱导SW1116细胞的凋亡。结论吡罗昔康抑制结肠腺癌细胞的增殖与抑制COX-2过度表达和促进细胞凋亡有关，由于吡罗昔康的效应呈现浓度和时间依赖性，在进行预防或治疗结肠癌的临床研究时，要考虑其有效剂量和用药间隔。     

Overexpression of cyclooxygenase-2 in multiple myeloma: association with reduced survival

Cyclooxygenases (COX) are key enzymes in the conversion of arachidonic acid to prostaglandins. Several studies have shown a relation between angiogenesis and COX-2 expression. Elevated expression of cyclooxygenase-2 (COX-2), however, has not been reported in multiple myeloma (MM) in the literature. The aim of this study is to investigate COX-2 expression in MM as well as its correlation with prognostic factors and estimated survival rates. Immunohistochemical staining of the paraffin-embedded bone marrow biopsy tissues (n = 51) was performed using isoform-specific COX-2 polyclonal antisera (Santa Cruz Biotechnology, Santa Cruz, CA). Results were correlated with recognized clinical parameters, which were retrospectively obtained from patients' files. There were 15, 19, and 17 bone marrow biopsy specimens with negative, weak-moderate, and strong COX-2 immunostaining, respectively. According to univariate analysis, beta2-microglobulin, age, stage, COX-2 expression, and serum lactate dehydrogenase levels were significant prognostic factors for survival in patients with multiple myeloma. COX-2 expression, age, and serum lactate dehydrogenase levels (greater than 1x normal level) were significant prognostic factors by multivariate analysis. Kaplan-Meier overall survival estimate of those patients with negative or weak-moderate COX-2 immunoreactivity in myeloma cells was significantly better than that of patients with strong COX-2 immunoreactivity (log-rank chi(2) = 21,43, P < 0.001). COX-2 overexpression was associated with reduced estimated survival. Poor prognostic factors such as LDH, age, and beta2-microglobulin were also correlated with COX-2 expression. Potent, specific COX-2 inhibitors showing evident antiangiogenic and antitumor effects on cancers could provide new therapeutic strategies in the treatment of MM.     

Bcl-2 expression significantly correlates with thymidylate synthase expression in colorectal cancer patients

AIM： To examine the expression of thymidylate synthase （TS） and oncoprotein Bcl-2 in advanced colorectal cancer （CRC） patients, and to determine their mutual relationship, association to therapeutic response and impact on disease outcome. METHODS： Tumor samples from 67 patients with CRC, who were treated at advanced stage with either irinotecan alone or in combination with 5-fluorouracil/ leucovorin, were analyzed for expression of TS and Bcl-2 using immunohistochemistry. RESULTS： A significant linear correlation between lower expression levels of Bcl-2 and lower levels of TS expression was found （P = 0.033）. Patients with high levels of both TS and Bcl-2 expression had a significantly longer disease-free survival （DFS） （42.6 mo vs 5.4 mo, n = 25） than those with low TS/Bcl-2 index （P = 0.001）. Tumors with low levels of both TS and Bcl-2 were associated with a longer survival with metastasis （WMS） interval in the whole patients group （n = 67, P = 0.035）. TS/Bcl-2 index was not significantly related to disease-specific survival. CONCLUSION： The present data suggest that CRC patients with low TS/Bcl-2 demonstrate a significantly shorter DFS and longer WMS.     

Overexpression of HER2/neu oncogene in pancreatic cancer correlates with shortened survival

Summary For the purpose of determining the prognostic significance of HER2/neu oncogene in pancreatic and ampullary cancers, 21 pancreatic cancers of ductal origin and six cancers of the ampulla of Vater were studied immunohistochemically using the monoclonal antibody (MAb) CB11, specifically reactive with HER2/neu product. Staining of the epithelium of the normal duct and acini was negative or weakly positive. Moderately and strongly positive reactions indicated the overexpression of this gene, and were found in 10 of 21 (47.6%) pancreatic cancers of ductal origin and in 2 of 6 (33.3%) ampullary adenocarcinomas. Overexpression of HER2/neu was closely and inversely related to the survival of the patients with pancreatic cancer of ductal origin: 19.1±11.7 mo for those not overexpressing vs 7.3±3.8 mo for the overexpressors (p<0.01). Among the pancreatic cancer group, 11 patients underwent cancer resection. The average survival for the 7 with nonoverexpressing cancer was 21.4±14.3 mo vs 10.5±3.6 mo for those with the overexpressing tumor. Among those not undergoing resection, the average survival for the 4 with nonoverexpressing cancer was 15.0 ±3.8 mo as contrasted to 5.2±2.1 mo for the overexpressors (p<0.01). Although the number of patients is small, these findings duggest that the overexpression of HER2/neu gene product may be frequently found in pancreatic cancer of ductal origin and may be one of the useful prognostic biomarkers for this cancer.     

E-cadherin expression correlates with tumor differentiation in colorectal cancer

BACKGROUND/AIMS: Epithelial cadherin (E-cadherin) is the main cell-cell adhesion molecule in all epithelia. Aberrant expression of this molecule has been implicated in tumor invasion and metastasis. We evaluated E-cadherin expression and cellular localization in colorectal cancer and investigated its relationship to histopathological features. METHODOLOGY: The expression of E-cadherin was evaluated in 57 formalin-fixed, paraffin-embedded specimens of colorectal cancer by immunohistochemistry. RESULTS: In normal colonic mucosa, E-cadherin was expressed uniformly at the cell membrane. Abnormal E-cadherin expression and/or cellular distribution was found in 46% of tumors. There was a significant correlation between E-cadherin expression and tumor grade with a trend towards reduced E-cadherin expression as the tumor grade increased. The association between E-cadherin expression and tumor stage was not significant. CONCLUSIONS: Abnormal E-cadherin expression in colorectal cancer correlates with loss of differentiation.     

Expression of cyclooxygenase-2 protein in colorectal carcinomas

Summary Background. Overexpression of cyclooxygenase-2 (COX-2) has been demonstrated in various human cancers, including colorectal cancer. Thus, overexpression of COX-2 may be involved in the growth and progression of cancer, and this may have prognostic significance. Aim. The aim of our study is to evaluate the expression of COX-2 in colorectal cancer tissue, and to examine the relationship of its expression to various clinicopathological parameters and patient survival. Methods. Formalin-fixed, paraffin-embedded tissue blocks were obtained from 60 patients who underwent surgery for colorectal carcinoma in 1995 at the Chonnam National University Hospital in Gwangju, Korea. We have used an immunohistochemical technique to localize COX-2 in colorectal carcinoma tissues. Results. Immunohistochemical staining of the colorectal cancer specimens demonstrated that COX-2 expression was localized to the carcinoma cells and was not detectable in the stromal compartment of the cancers. The COX-2 immunostaining pattern was predominantly homogenous, and perinuclear cytoplasmic within the tumors. Normal colonic epithelium adjacent to the tumor showed no staining for COX-2. The COX-2 protein was detected in 70% (42/60) of colorectal carcinoma tissues. However, no significant correlation was found between COX-2 expression and various clinicopathological parameters, including histologic grade, tumor size, depth of invasion, lymph node metastasis, distant metastasis, or stage. Furthermore, COX-2 expression did not correlate with patient survival (p=0.401). Conclusion. These results suggest that COX-2 expression may play an important role in the evolution of colon carcinogenesis. However, further studies are needed to determine the prognostic relevance of COX-2.