Dysregulation of Claudin family genes in colorectal cancer in a Chinese population

Claudins play an important role in tumor metastasis and in invasiveness of colorectal cancer (CRC). We have evaluated the relationship between CRC and expression of the claudin genes in Chinese patients with CRC. We measured CLDN1 and CLDN7 mRNA using quantitative PCR, and protein levels with immunohistochemistry in cancer tissues and adjacent normal tissue. Cancer tissues had significantly higher levels of CLDN1, and significantly lower levels of CLDN3, CLDN4, and CLDN7 than did normal tissue. CLDN3, CLDN4, and CLDN7 expression levels were higher in CRC of the protruded type than in CRC of the infiltrative type. Expression of CLDN7 correlated with lymph node metastasis. Stage N0 cancer tissues had higher levels of CLDN7 than did stages N1 and N2, suggesting that CLDN7 expression was closely related to the extent of lymph node metastasis. CLDN1 protein was upregulated, but CLDN7 protein was downregulated in cancer tissues when compared with expression in adjacent normal tissues. In conclusion, CLDN3, CLDN4, and CLDN7 were significantly downregulated, whereas CLDN1 was significantly upregulated in CRC. The altered expression of claudin genes may play a role in the initiation and development of CRC.     

结直肠癌中HSP60和HSP27表达的免疫组织化学研究

目的1观察热休克蛋白60和热休克蛋白27在结直肠癌中的表达及意义。方法：收集结直肠癌80例,其中淋巴结转移40例（转移组）,无淋巴结转移40例（无转移组）;另外,在结直肠癌80例中,有结直肠腺瘤（腺瘤组）以及距肿块15cm以上的正常肠粘膜（对照组）各40例。应用免疫组织化学SP法检测组织中蛋白的表达。结果：HSP60的表达主要定位在癌细胞胞浆,在对照组、腺瘤组、非转移组、转移组中的表达阳性率分别为25％、30％、57．5％、90％,组间比较发现,对照组与转移组、腺瘤组与转移组、转移组与非转移组（x^2=10．912,P〈0．001）的HSP60阳性表达率存在统计学差异;而对照组与腺瘤和非转移组间以及腺瘤与非转移组间无统计学差异。HSP27的表达主要定位在癌细胞的胞浆,在对照组、腺瘤组、非转移组、转移组的表达阳性率分别为5％,35％,50％,90％,组间比较发现,对照组分别与无淋巴结转移组、淋巴结转移组;腺瘤组分别与转移组;非转移组与转移组间存在统计学差异,腺瘤与非转移组间无统计学差异。HSP60和HSP27表达间无统计学相关。结论：HSP27表达可能与结直肠癌发生和转移相关。而HSP60的表达可能在结直肠癌转移中具有重要意义。     

Nuclear localization and Overexpression of Smoothened in Pancreatic and Colorectal Cancers

Smoothened (SMO) is a significant signalling protein which functions as a key transducer for the hedgehog signalling pathway, an important signalling mechanism with key roles in development and oncogenesis. The correlation of expression dynamics of SMO with pancreatic and colorectal cancer genesis has been known but with ambiguity. Therefore, in this study, we investigated messenger RNA (mRNA) and protein expression of SMO in pancreatic and colorectal cancers in our population and assessed relationship with various clinicopathological parameters. Surgically resected tumour and adjacent histologically normal tissues from 33 and 61 pancreatic and colorectal cancer patients were investigated in the present study. Expression of SMO was analysed by quantitative real-time polymerase chain reaction and immunohistochemistry. At mRNA level, SMO was overexpressed in 72.72% (24 of 33) and 50.81% (31 of 61) of the pancreatic and colorectal cancer cases as compared with their adjacent normal tissues. SMO immunohistochemical analysis revealed nuclear localization and overexpression was observed in 51.51% (17 of 33) and 40.98% (25 of 61) of pancreatic and colorectal cancer tissues. SMO overexpression was significantly associated with smoking, late-stage disease and lymph node metastasis in patients with Colorectal cancer. Our results showed that SMO is dysregulated in pancreatic and colorectal cancers and may be considered as a target in cancer therapeutics.     

Correlation of N-myc downstream-regulated gene 1 subcellular localization and lymph node metastases of colorectal neoplasms

In colorectal neoplasms, N-myc downstream-regulated gene 1 (NDRG1) is a primarily cytoplasmic protein, but it is also expressed on the cell membrane and in the nucleus. NDRG1 is involved in various stages of tumor development in colorectal cancer, and it is possible that the different subcellular localizations may determine the function of NDRG1 protein. Here, we attempt to clarify the characteristics of NDRG1 protein subcellular localization during the progression of colorectal cancer. We examined NDRG1 expression in 49 colorectal cancer patients in cancerous, non-cancerous, and corresponding lymph node tissues. Cytoplasmic and membrane NDRG1 expression was higher in the lymph nodes with metastases than in those without metastases (P < 0.01). Nuclear NDRG1 expression in colorectal neoplasms was significantly higher than in the normal colorectal mucosa, and yet the normal colorectal mucosa showed no nuclear expression. Furthermore, our results showed higher cytoplasmic NDRG1 expression was better for differentiation, and higher membrane NDRG1 expression resulted in a greater possibility of lymph node metastasis. These data indicate that a certain relationship between the cytoplasmic and membrane expression of NDRG1 in lymph nodes exists with lymph node metastasis. NDRG1 expression may translocate from the membrane of the colorectal cancer cells to the nucleus, where it is involved in lymph node metastasis. Combination analysis of NDRG1 subcellular expression and clinical variables will help predict the incidence of lymph node metastasis.     

抑癌基因MTUS1在结直肠癌的表达与其淋巴结转移呈负相关

微管相关肿瘤抑制基因1(MTUS1)是一个新的肿瘤抑制基因,编码血管紧张素II AT受体结合蛋白（ATIPs）. MTUS1基因表达下调可促进肿瘤细胞增殖,但MTUS1基因表达在结直肠癌转移中的作用尚不知晓.本文以接受根治性手术、经病理检查证实的50例结直肠癌患者新鲜癌组织、癌旁组织和远癌组织为材料,探索MTUS1基因表达与结直肠癌淋巴结转移的关系. 荧光定量PCR及蛋白质免疫印迹揭示,有淋巴结转移的结直肠癌患者的癌及癌旁组织MTUS1 基因表达的mRNA及蛋白质水平明显低于无淋巴结转移的患者. MTUS1 蛋白质在淋巴结转移的结直肠癌患者的癌及癌旁组织表达下调,并进一步得到免疫组织化学的验证.实验结果提示,MTUS1的表达量与肿瘤的侵润深度有明显的负相关性.结合临床资料,推断抑癌基因MTUS1在肿瘤的发生、发展及淋巴转移中发挥重要作用.     

p16基因甲基化状态与散发性大肠癌的相关性研究

为探讨p1 6基因甲基化状态与散发性大肠癌发生发展的关系 ,用甲基化特异性的聚合酶链反应 (methylati omspecificPCR ,MSP)结合测序检测散发性大肠癌及相应癌旁组织p1 6基因甲基化状态。研究发现p1 6基因在散发性大肠癌中甲基化率为 2 8 9% (1 3 4 5 ) ,有 8例癌及癌旁组织都发生了甲基化 ;有淋巴结及远处转移的甲基化率为5 0 % (8 1 6 ) ,高于无转移的甲基化率 2 0 8(5 2 4 ) (P <0 0 5 )。p1 6基因高甲基化是散发性大肠癌中常见的分子改变之一 ,大肠癌中p1 6基因高甲基化可能发生在癌变早期并与大肠癌的恶性进展有相关性     

结直肠癌COX-2表达及其与临床病理特征的相关性分析

目的:探讨结直肠癌环氧化酶-2(cyclooxygenase-2,COX-2)的表达及其与临床病理特征的相关性。方法:选择2017年8月～2019年6月在本院外科手术诊治的结直肠癌患者60例,取所有患者的病灶组织标本与癌旁组织标本,采用PCR与免疫组化法检测COX-2 mRNA与蛋白表达情况,分析其与患者的临床病理特征的相关性。结果:直肠癌组织COX-2 mRNA与蛋白表达阳性率分别为63.3%和55.0%,显著高于癌旁组织的20.0%和16.7%(P0.05)。随着结直肠癌的病理分期及分化程度的增加、淋巴结转移的发生,直肠癌组织的COX-2 mRNA、蛋白表达阳性率显著升高(P0.05)。Spearman等级相关分析显示直肠癌组织的COX-2 mRNA、蛋白表达阳性率与临床分期、组织学分化与淋巴结转移都存在显著相关性(P0.05)。Cox模型多因素分析显示临床分期、组织学分化与淋巴结转移都是影响COX-2蛋白表达的主要因素(P0.05)。结论:结直肠癌COX-2的mRNA与蛋白都呈现高表达,与患者的临床分期、组织学分化与淋巴结转移显著相关。     

Matrix metalloproteinase 2 promotes cell growth and invasion in colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the western world. In this study, we evaluated the expression of matrix metalloproteinase 2 gene (MMP2) in CRC and analyzed its correlation with clinicopathological features. We found that the expression of MMP2 was significantly higher in CRC tissues than in the colorectal tissues. In addition, high levels of MMP2 protein were positively correlated with the status of tumor size, lymph node metastasis, distant metastasis, Dukes' stage, and tumor invasion. Moreover, patients with higher MMP2 levels had markedly shorter overall survivals than those with low MMP2 levels. Multivariate analysis results suggested that the level of MMP2 expression is an independent prognostic indicator for the survival of patients with CRC. Silencing MMP2 expression in CRC cell lines with lentiviral-mediated shRNA markedly suppressed cell proliferation, colony formation, and invasion. Furthermore, we observed that vascular endothelial growth factor (VEGF) and membrane type 1 (MT1)-MMP protein levels were decreased in MMP2-down-regulated colorectal cells. Therefore, our study demonstrated that MMP2 is an important factor related to carcinogenesis and metastasis of CRC, and MMP2 promotes CRC cell growth and invasion by up-regulating VEGF and MT1-MMP expression, which makes this pathway a potential target for cancer treatment.     

NEFL mRNA expression level is a prognostic factor for early-stage breast cancer patients

Neurofilament, light polypeptide (NEFL) was demonstrated to be ectopically expressed in breast cancer tissues and decreased in lymph node metastases compared to the paired primary breast cancers in our previous study. Moreover, in several studies, NEFL was regarded as a tumor suppressor gene, and its loss of heterozygosity (LOH) was related to carcinogenesis and metastasis in several types of cancer. To explore the role of NEFL in the progression of breast cancer and to evaluate its clinical significance, we detected the NEFL mRNA level in normal breast tissues, primary breast cancer samples and lymph node metastases, and then analyzed the association between the NEFL expression level and several clinicopathological parameters and disease-free survival (DFS). NEFL mRNA was found to be expressed in 92.3% of breast malignancies and down-regulated in lymph node metastases compared to the paired primary tumors. NEFL mRNA level was lower in primary breast cancers with positive lymph nodes than in cancers with negative lymph nodes. Moreover, a low expression level of NEFL mRNA indicated a poor five-year DFS for early-stage breast cancer patients. Thus, NEFL mRNA is ectopically expressed in breast malignancies and could be a potential prognostic factor for early-stage breast cancer patients.     

Iterative local Gaussian clustering for expressed genes identification linked to malignancy of human colorectal carcinoma

Gene expression profiling plays an important role in the identification of biological and clinical properties of human solid tumors such as colorectal carcinoma. Profiling is required to reveal underlying molecular features for diagnostic and therapeutic purposes. A non-parametric density-estimation-based approach called iterative local Gaussian clustering (ILGC), was used to identify clusters of expressed genes. We used experimental data from a previous study by Muro and others consisting of 1,536 genes in 100 colorectal cancer and 11 normal tissues. In this dataset, the ILGC finds three clusters, two large and one small gene clusters, similar to their results which used Gaussian mixture clustering. The correlation of each cluster of genes and clinical properties of malignancy of human colorectal cancer was analysed for the existence of tumor or normal, the existence of distant metastasis and the existence of lymph node metastasis.     

直肠癌组织中PTEN和Notch1的表达及其与临床病理参数的关系

目的:探究直肠癌组织中PTEN和Notch1的表达及其与临床病理参数的关系。方法:收集2014年1月~2015年4月,我院肿瘤外科确诊48例直肠癌病理组织标本与20例直肠癌患者癌旁正常组织标本为研究对象,应用免疫组化链霉菌抗生物素蛋白-过氧化物酶连结法(S-P法)分析PTEN和Notch1蛋白在直肠癌病理组织和正常组织中的表达情况。结果:PTEN和Notch1主要表达于直肠癌组织细胞质中,呈现棕黄色;Notch1在直肠癌病理组织中表达率显著高于正常组织(P0.05);PTEN在正常组织表达率显著高于在直肠癌组织(P0.05);Notch1在淋巴转移、中底分化及分期为C期患者病理组织中表达率较高(P0.05);PTEN在无淋巴转移、中底分化程度及A+B期患者病理组织表达率较高(P0.05);相关性分析显示,Notch1和PTEN在直肠癌病理组织中表达呈现负相关关系(r=-0.534,P=0.000)。结论:Notch1和PTEN表达失调在直肠癌的发生、发展和淋巴结转移中有重要作用;PTEN表达可能对直肠癌的发生、发展具有抑制作用,Notch1表达可能对直肠癌的发生、发展具有促进作用。     

The ratio of splicing variants of MGC-24/CD164, a sialomucin, correlates with the metastatic potential of colorectal carcinomas

MGC-24/CD164 is a sialomucin expressed in many normal and cancerous tissues. In humans, soluble and transmembrane forms of MGC-24 are produced by alternative splicing. The total MGC-24 RNA level was found to be lower in human colorectal carcinomas as compared with the adjacent normal mucosal tissues. Lower MGC-24 mRNA levels in colon carcinomas and in the adjacent normal mucosa epithelium correlate with lymphatic vessel invasion by the carcinoma. The ratio of the soluble form to the transmembrane form of the mRNA in colorectal carcinomas was determined by ribonuclease protection assay. Higher ratios were correlated with less venous invasion and less remote metastasis, which became evident during postoperative observation.     

结直肠癌mP53 和PCNA 表达的相关性及临床意义

目的:探讨结直肠癌中突变型P53基因(mP53)和增殖细胞核抗原(PCNA)表达的相关性及临床意义。方法:应用免疫组化二步法,检测60例结直肠癌组织及20例正常肠粘膜中mP53、PCNA的表达,结合临床病理资料进行统计分析。结果:60例结直肠癌中mP53阳性表达率65.0%,PCNA阳性表达率78.3%,20例正常肠粘膜中mP53、PCNA表达均为阴性(P<0.05)。mP53和PCNA阳性表达率在低分化组、浆膜层浸润组、淋巴结转移组均较高(P均<0.05)。mP53和PCNA表达呈正相关(r=0.58,P<0.05)。结论:mP53和PCNA在结直肠癌中表达均增高,二者与结直肠癌病理学分级、浸润深度和淋巴结转移有关,可作为判断结直肠癌预后的参考指标。     

Clinical Significance of Frizzled Homolog 3 Protein in Colorectal Cancer Patients

Frizzled homolog 3 receptor was up-regulated in several gastrointestinal cancers such as esophageal and gastric cancers. Moreover, frizzled homolog 3 has recently reported to be expressed in colorectal adenoma specimens. In the present study, we investigated the clinical significance of frizzled homolog 3 protein in colorectal cancer patients. Using immunocytochemical staining, frizzled homolog 3 expression was examined in 186 colorectal cancer specimens, 79 colorectal adenoma specimens, 133 colorectal polyp specimens, 127 colorectal cancer specimens with lymph node and/or distant metastasis, 310 specimens of various non-colorectal cancer metastatic carcinomas and 40 specimens with simultaneous occurrence of colorectal cancer, colorectal adenoma and colorectal polyp. Statistical analysis was used to correlate frizzled homolog 3 protein expression to the clinicohistopathological factors, recurrence/metastasis and survival after follow-up for 42 months in colorectal cancer patients. Frizzled homolog 3 protein was expressed in 100% colorectal cancer specimens, 89% colorectal adenoma specimens, 75% colorectal polyp specimens and 69% normal colorectal epithelial tissues. Moreover, frizzled homolog 3 immunocytochemical scores were highly correlated with colorectal cancer progression. Furthermore, frizzled homolog 3 was expressed in a comparatively lower percentage of metastatic hepatocellular carcinoma and metastatic renal clear cell carcinoma with focal and very weak staining than other metastatic tumor types. On the other hand, the frizzled homolog 3 immunocytochemical scores of colorectal adenomas with synchronous colorectal carcinomas were significantly higher than those of pure colorectal adenomas. Statistical analysis showed that frizzled homolog 3 immunocytochemical scores were associated with Dukes stage and lymph node status. Finally, stratified groups of colorectal cancer patients had significant differences in their recurrence/metastasis and survival. In conclusion, the present large-scale study has clearly showed that frizzled homolog 3 protein can generate clinically important information for colorectal cancer patients.     

Overexpressed RACK1 is positively correlated with malignant degree of human colorectal carcinoma

RACK1 is a crucial scaffold and anchoring protein, which plays a vital role in multiple signaling pathways of tumorigenesis. The aim of the present study was to identify the correlation between expressions of RACK1 and malignant degrees in colorectal carcinoma (CRC) patients. All together 157 CRC patients were enrolled, and their clinical data were analyzed. Expressions of RACK1 in CRC and pericarcinous tissues in these patients were determined by RT-PCR, Western-blot, and immunohistochemistry, respectively. The correlation between RACK1 expressions and histological grades, as well as lymph node metastasis was evaluated. Results showed that the expressions of RACK1 were positively correlated with differentiation level and lymph node metastasis in CRC patients.     

Upregulation of the amino acid transporter ATB0,+ (SLC6A14) in colorectal cancer and metastasis in humans

ATB(0,+) (SLC6A14) is a Na(+)/Cl(-)-coupled arginine transporter expressed at low levels in normal colon. Arginine is an essential amino acid for tumor cells. Arginine is also the substrate for nitric oxide synthases (NOSs). Since arginine and arginine-derived nitric oxide (NO) play a critical role in cancer, we examined the expression of ATB(0,+) in colorectal cancer. Paired normal and cancer tissues from colectomy specimens of 10 patients with colorectal cancer and from the liver tissue of one patient with hepatic metastasis from a colonic primary were used for the analysis of the levels of ATB(0,+) mRNA, inducible NOS (iNOS) mRNA and the corresponding proteins. Tissues samples from the colon, liver, and lymph nodes of an additional patient with metastatic colon cancer were analyzed for ATB(0,+) protein alone. We also examined the levels of nitrotyrosylated proteins. The ATB(0,+) mRNA increased 22.9+/-3.0-fold in colorectal cancer compared to normal tissue and the increase was evident in each of the 10 cases examined. iNOS mRNA increased 5.2+/-1.1-fold in cancer specimens. The changes in mRNA levels were associated with an increase in ATB(0,+), iNOS, and nitrotyrosylated proteins. The increased expression of ATB(0,+) and iNOS was also demonstrated in liver and lymph node specimens with metastases from colonic primaries. This study strongly suggests that the upregulation of ATB(0,+) may have a pathogenic role in colorectal cancer. Since ATB(0,+) is a versatile transporter not only for arginine but also for several drugs including NOS inhibitors, these findings have significant clinical and therapeutic relevance.