长链非编码RNA EVADR促进人结直肠癌细胞系增殖及迁移

目的探讨lncRNA EVADR对人结直肠癌HCT116和LOVO细胞系的增殖和迁移的影响以及其作用机制。方法利用慢病毒感染方式分别构建稳定过表达lncRNA EVADR的HCT116和LOVO细胞系;用CCK-8检测细胞的增殖;Transwell小室法检测细胞迁移能力,Western blot检测E-cadherin的表达,实时荧光定量PCR检测Snail、Slug、ZEB1和ZEB2 mRNA的表达。结果成功构建了稳定过表达lncRNA EVADR的结直肠癌HCT116和LOVO细胞系。与HCT116-NC和LOVO-NC细胞组对比,HCT116-EVADR与LOVO-EVADR细胞组的增殖和迁移能力明显提高(P<0.05)。同时,上皮标志物E-cadherin表达明显降低,而Snail、Slug、ZEB1和ZEB2间质化标志物的表达升高。结论过表达lncRNA EVADR具有促进结直肠癌HCT116和LOVO细胞的增殖与迁移能力,可能通过调节结直肠癌细胞上皮间质转化(EMT)发挥作用。     

PXMP4促进结直肠癌细胞增殖、迁移和侵袭

目的 探讨过氧化物酶体膜蛋白4(peroxisomal membrane protein 4,PXMP4)对结直肠癌细胞增殖、迁移和侵袭能力的影响.方法 采用生物信息学分析65例配对结直肠癌组织中PXMP4 mRNA的表达.应用免疫组化检测112例配对结直肠癌组织中PXMP4的表达,并进行临床病理相关分析;利用RT-P...     

Metastatic and non-metastatic colorectal cancer (CRC) cells induce host metalloproteinase production in vivo

Numerous studies have demonstrated the persistent localization of matrix metalloproteinase (MMP) expression to the interface between invading human colorectal cancer (CRC) cells and surrounding stroma supporting a role for MMPs in CRC invasion and metastasis. The present study sought to determine whether CRC cells of varying metastatic potential would have differential effects on host MMP release. Subcutaneous CRC tumors were generated in BALB/c nude mice using three CRC cell lines: SW480, SW620, and the highly metastatic SW620S5 clone. Representative samples from the subcutaneous CRC were then orthotopically implanted on the cecum of recipient nude mice. Subcutaneous and cecal tumors were analyzed for MMP expression via zymography, western blot, and RT-PCR. In vitro, none of the three cell lines expressed MMP-2 nor MMP-9. In contradistinction, the subcutaneous tumors expressed limited amounts of MMP-2 and MMP-9 while the cecal tumors expressed significant amounts of MMP-2 and MMP-9 as well as other smaller members of the MMP family. MMP-9 mRNA and protein was confirmed as host in origin by RT-PCR with mouse specific primers and a mouse MMP-9 molecular weight of 105 kDa as determined by zymography and western blot analysis. In situ hybridization also localized the mRNA for MMP-9 to the host stromal cells. In conclusion, CRC cells appear incapable of producing MMP-2 and MMP-9 in vitro but are capable of up-regulating host MMP production in vivo. Enhanced host MMP-9 production in metastatic CRC cell-derived subcutaneous and cecal tumors suggests that metastatic colon cells may acquire the expression of important MMP regulating factor(s) in vivo.     

黄芩素抑制胃癌MGC-803细胞增殖和迁移

目的:探讨黄芩素(BAI)对胃癌MGC-803细胞增殖和迁移的作用及机制。方法:MGC-803细胞用不同浓度BAI处理后,采用MTT法检测细胞的存活率;平板集落形成实验检测细胞的集落形成能力;划痕愈合实验和Transwell小室迁移实验检测细胞的迁移能力;ELISA检测12-羟基二十碳四烯酸(12-HETE)的浓度;Western blot实验检测血小板型12-脂氧合酶(p12-LOX)、血管内皮生长因子(VEGF)、p-ezrin和上皮-间充质转化(EMT)标志物蛋白的表达。结果:BAI可显著抑制MGC-803细胞的增殖、平板集落形成及迁移(P0.05或P0.01),显著下调p12-LOX代谢产物12-HETE的浓度(P0.05或P0.01),并显著下调p12-LOX、VEGF、p-ezrin、vimentin和Snail蛋白的表达水平(P0.05或P0.01),上调E-cadherin蛋白的表达水平(P0.01)。结论:BAI可有效抑制胃癌MGC-803细胞的增殖和迁移,其机制与BAI调控p12-LOX、VEGF、p-ezrin及EMT相关蛋白的表达变化有关。     

CTHRC1 promotes human colorectal cancer cell proliferation and invasiveness by activating Wnt/PCP signaling

Collagen triple helix repeats containing 1 (CTHRC1) participates in vascular remodeling, bone formation, and developmental morphogenesis. Recently, CTHRC1 has been found up-regulated in many solid tumors and contributes to tumorigenesis, but its role in the progression of human colorectal cancer (CRC), remains unclear. In this study, CTHRC1 expression in human CRC cell lines was evaluated by quantitative real-time PCR and immunoblot analyses. The role of CTHRC1 in CRC cell proliferation and extracellular matrix invasion in vitro was analyzed by gene over-expression and recombinant protein. Reporter luciferase assay was used to reveal key relevant signaling pathways involved in CRC cells. The results show that CTHRC1 is secreted both by colorectal epithelia cells and stromal fibroblasts. Recombinant CTHRC1 promotes CRC cell migration and invasion dose-dependently. CTHRC1 overexpression promotes CRC cell migration, invasion and proliferation in vitro. Wnt/PCP signaling but not Wnt/catenin signaling was activates by CTHRC1 in CRC cells. Together, CTHRC1 promotes CRC cell proliferation, migration and invasion in vitro, which is possibly mediated by activating Wnt/PCP pathway.     

Expression profiling and interferon-beta regulation of liver metastases in colorectal cancer cells

Liver metastasis is the major cause of death among colorectal cancer patients. Many gene products have been associated with the colon cancer cells' ability to metastasize to the liver, including carcinoembryonic antigen (CEA) and mucins. In this study we examined changes in expression of 384 genes in a model of human colorectal cancer metastasis in nude mice. Using DNA microarrays, we compared expression between MIP-101 cells, a poorly metastatic human colon cancer cell line, with an interferon-beta (IFN-β) resistant subline of MIP-101 (β-MIP) that is metastatic to the liver. Treatment of β-MIP cells with increasing concentrations of IFN-β caused a reversion to the non-metastatic phenotype. The array data showed down-regulation of genes involved in apoptosis in β-MIP cells and their return to the MIP-101 pattern upon IFN-β treatment. Cluster analysis also showed involvement of genes belonging to cell cycle, angiogenesis and invasion pathways. Selected genes were chosen to validate the microarray data by semi-quantitative RT-PCR. Association between gene expression pattern and metastatic phenotype was verified by intra-splenic injection in nude mice. The number of genes examined in this study was small, but carefully selected. Significant changes associated with cell growth and survival were observed, which gave the metastatic cells an advantage to grow in the liver. This information may help identifying new markers for colorectal cancer prognosis as well as aid the development of new therapeutic approaches. This revised version was published online in July 2006 with corrections to the Cover Date.     

MicroRNAs in colorectal cancer metastasis

Metastatic disease is the major cause of death in colorectal cancer (CRC) patients. The metastatic process is highly inefficient and comprises multiple sequential steps. While many genetic factors relevant in this process have already been identified, the epigenetic factors underlying each step still remain obscure. MicroRNAs (miRNAs) are key regulators in tumourigenesis, but their role in the development of cancer metastasis is poorly investigated. The majority of miRNAs involved in the metastatic process have been identified in breast cancer cell lines, and in CRC less data are available. We review the role of miRNAs in the metastatic pathway of CRC, including escape of apoptosis, epithelial-mesenchymal transition (EMT), angiogenesis, and invasion. Better understanding of the complex role of miRNAs in the development of CRC metastases may provide new insights that could be of therapeutic consequence.     

循环癌细胞p53表达在大肠癌患者检测中的临床意义

目的探讨从大肠癌患者外周血检测循环癌细胞胡表达的临床意义。方法用流式细胞术，对术前128例大肠癌患者外周血循环癌细胞胡异常表达进行检测，实验数据用SPSS统计软件处理。结果大肠癌外周血循环癌细胞胡异常表达与患者淋巴结转移显著相关（P〈0．01）；p53异常表达与患者肿瘤分化程度密切并呈正相关（r=0．8476，P〈0．05）；p53异常表达与淋巴结转移在左右结肠癌病例中差异具有统计学意义（P〈0．05）。结论外周血中可检出大肠肿瘤细胞生物学标志物胡突变表达，这可为大肠痛预测复发及远端微转移提供了一个有效的手段。     

Knockdown of KDM1B inhibits cell proliferation and induces apoptosis of pancreatic cancer cells

Pancreatic cancer (PC) is one of the common malignant tumors in digestive tract with a high fatality rate. The oncogenic role of lysine-specific demethylase1 (LSD1/KDM1?A) has been well recognized in PC. While, the role of its homolog LSD2 (KDM1B) in regulating PC progression is poorly understood. In this study, we attempted to evaluate the functional role of KDM1B in PC cells. The expression of KDM1B was detected by immunohistochemistry and immunoblotting in PC tissues and cells. Lentivirus-mediated shRNA was applied to silence KDM1B in PANC-1 and SW1990 cells. Cell proliferation was measured by MTT and Celigo assay. Cell apoptosis was determined by both Caspase-Glo^®3/7 assay and Flow cytometry. Intracellular signaling molecules were detected using a PathScan intracellular signaling array kit. In this study, we found KDM1B was highly expressed in PC tissues compared to paracancerous tissues. Moreover, elevated expression of KDM1B was detected in PC cell lines (BxPC-3, CFPAC-1, PANC-1 and SW1990) as compared with a normal human pancreatic duct epithelial cell line (HPDE6-C7). Further investigations revealed that KDM1B knockdown significantly inhibited PC cell proliferation. Furthermore, the apoptosis of PANC-1 and SW1990 cells was significantly increased after KDM1B knockdown. Notably, the activations of p-ERK1/2, p-Smad2, p-p53, cleaved PARP, cleaved Caspase-3, cleaved Caspase-7, p-eIF2a and Survivin were promoted by KDM1B knockdown, while IkBa was suppressed. Taken together, our findings provided new insights into the critical and multifaceted roles of KDM1B in the regulation of cell proliferation and apoptosis, and offered a potentially novel target in preventing the progression of PC.     

MicroRNA-145 suppresses cell migration and invasion by targeting paxillin in human colorectal cancer cells

A number of cancers show increased expression of paxillin which plays a central role in tumor progression, including colorectal cancer. However, the mechanisms causing paxillin upregulation remains unclear. In our study, bioinformatics analyses suggested that paxillin is predicted to be a direct target of miR-145. We firstly identified paxillin as a new target of miR-145 and demonstrated that miR-145 inhibits paxillin expression by binding to the paxillin mRNA 3’UTR. Therefore, we assume overexpression of paxillin induced by suppression of miR-145 may promote cell migration and invasion. We detected the expression of paxillin and miR-145 in human colorectal cancer tissues by real-time quantitative PCR. Higher expression of paxillin and lower expression of miR-145 was observed in colorectal cancer tissues than corresponding paracancerous tissue. Moreover, the expression of paxillin was negatively correlated with miR-145 expression. A dual-luciferase reporter assay was used to confirm that paxillin was a direct target of miR-145. In CRC cell lines, overexpression of miR-145 could downregulate paxillin protein expression levels, and ectopic overexpression of miR-145 mimics or inhibitor could inhibit or promote cell migration, invasion, proliferation and clone formation in vitro. Taken together, these data suggested that miR-145 plays a pivotal role in colon cancer through inhibiting cell proliferation migration and invasion, and miR-145 may serve as a tumor suppressor by targeting paxillin gene.     

Knockdown of TMEM45A inhibits the proliferation,migration and invasion of glioma cells

Gliomas are the most common and aggressive type of primary adult brain tumor. Although high expression and prognostic value of TMEM45A has been recently reported in various types of human tumors, the association of TMEM45A expression and glioma is still unknown. Here, we reported that TMEM45A was significantly overexpressed in glioma tissues compared to non-tumorous brain tissues. Furthermore, TMEM45A mRNA levels were gradually increased with the increasing severity of histological grade of glioma. Moreover, high TMEM45A expression level was correlated with short survival time of glioma patients. Down-regulation of TMEM45A in two glioma cell lines, U251 and U373 by transected with TMEM45A siRNA resulted in a significant reduction of cell proliferation and G1-phase arrest. Additionally, we found that suppressing of TMEM45A expression in glioma cells remarkably suppressed cell migration and cell invasion. More importantly, TMEM45A siRNA treatment significantly down-regulated the proteins promoting cell cycles transition (Cyclin D1, CDK4 and PCNA) and cell invasion (MMP-2 and MMP-9), which indicted a possible mechanism underlying its functions on glioma. In summary, our study suggests that TMEM45A may work as an oncogene and a new effective therapeutic target for glioma treatment.     

Genetic imbalances with impact on survival in colorectal cancer patients

AIMS: To investigate the prognostic significance of chromosomal alterations in colorectal cancer patients. Histopathological tumour classification is still considered to be the gold standard for the characterization of solid tumours. However, it is well known that such established parameters do not satisfactorily predict the clinical outcome in individual cases. Markers that reliably predict survival are needed. These markers should guide the clinical treatment of neoplastic disease. METHODS AND RESULTS: Chromosomal imbalances in 61 colorectal carcinoma specimens in 37 patients determined by comparative genomic hybridization were correlated with patient survival using custom-made computer software which enabled the assessment of individual chromosomal loci. Kaplan-Meier analysis revealed that over-representations of 2p14-15, 6q23-6q24, 15q22-15q23, 22q11.2 and deletions of 1p36.1-36.2, 4q31.3, 4q35, 8q12-q21, 8p11.2 and 9p22 were significantly associated with shorter disease-specific survival, whereas over-expression of 20q13.3 and deletion of 18q11.2 were significantly associated with longer disease-specific survival in this collection of colorectal cancers. Multivariate Cox proportional hazards regression models consistently identified gains of 2p14-15, 15q22-23, 22q11.2 and losses of 1p36.1-36.2 and 4q35 as independent markers of shorter patient survival carrying greater significance than the classical clinicopathological parameters of nodal status and tumour grade. CONCLUSIONS: These five markers allow a molecular categorization of patients into high and low clinical risk groups. Thus, the genomic data have refined the histopathological classification highlighting the necessity for a supplementary genetically based stratification of colorectal cancer.     

体外骨形态发生蛋白4抑制乳腺癌细胞的增殖和迁移

目的:研究骨形态发生蛋白4(BMP4)对乳腺癌细胞MCF-7增殖、迁移和侵袭能力的影响.方法:将重组慢病毒Lv-BMP4及干扰慢病毒Lv-shBMP4感染MCF-7细胞,构建MCF-7/Lv-BMP4过表达组及MCF-7/Lv-shBMP4干扰实验组,同时设空白组(Blank)、慢病毒空载对照组(Lv-NC)、 过表达...     

RILP inhibits proliferation,migration, and invasion of PC3 prostate cancer cells

RILP (Rab-interacting lysosomal protein) is a key regulator of lysosomal transport and a potential tumor suppressor. However, the role of RILP in prostate cancer and the underlying mechanism of RILP in regulating the proliferation, migration, and invasion of prostate cancer cells remain to be studied. In this study, we confirmed RalGDS (Ral guanine nucleotide dissociation stimulator) as the interaction partner of RILP in PC3 prostate cancer cells. Immunofluorescence microscopy showed that RILP recruits RalGDS to the lysosomal compartment. We found that RILP inhibits the activation of RalA and downstream effector RalBP1, and negatively regulates the downstream molecular phosphorylation of Ras. We showed that RILP inhibits the proliferation, migration, and invasion of PC3 prostate cancer cells, which may give rise to novel ideas for cancer treatment.     

Less aggressive features of colorectal cancer with liver metastases showing macroscopic intrabiliary extension

We have previously reported the frequent occurrence of bile duct invasion by liver metastases from colorectal cancer. We found that patients with macroscopic intrabiliary cancer growth survive longer after hepatectomy than those without this feature. In the present study, we analyzed the clinicopathological features of primary colorectal cancer showing macroscopic intrabiliary extension of liver metastases. We reviewed 217 patients who underwent initial hepatic resection for colorectal liver metastasis between 1992 and 1998, and analyzed the corresponding primary colorectal cancers clinicopathologically. Microscopic bile duct invasion was found in 89 of 217 cases (40.6%) and, of these cases, 23 (10.6%) had macroscopic intrabiliary extension. Histological sections of the corresponding primary colorectal cancer were available in eight (group A) of these 23 cases. These were compared with 20 cases, selected randomly, of colorectal cancer that did not show bile duct invasion and were diagnosed as liver metastases. These patients underwent hepatectomy during the same period as group A and were used as a control (group B). The histology of the primary tumors revealed well-differentiated adenocarcinoma in 100% of group A and in 25% of group B. The average maximum diameter of the primary tumor was 5.32 cm in group A and 3.61 cm in group B. Venous invasion was detected in 25% of group A and in 90% of group B (P < 0.01), while the incidences of lymphatic vessel invasion and lymph node metastases were similar between the groups. These data suggest that macroscopic intrabiliary extension could be a good indicator of a unique subgroup of colorectal cancers showing less aggressive features even though they develop liver metastases. Careful histological evaluation is important even for metastatic tumors.     

Trypsin in colorectal cancer: molecular biological mechanisms of proliferation, invasion, and metastasis

Trypsin is involved in colorectal carcinogenesis and promotes proliferation, invasion, and metastasis. Although a well-known pancreatic digestive enzyme, trypsin has also been found in other tissues and various cancers, most importantly of the colorectum. Moreover, colorectal cancers with trypsin expression have a poor prognosis and shorter disease-free survival. Biological understanding of how trypsin causes cancer progression is emerging. It seems to act both directly and indirectly through a 'proteinase-antiproteinase-system', and by activation of other proteinase cascades. Invasion of the basal membrane by cancer cells may be promoted directly by trypsin digestion of type I collagen. Trypsin activates, and is co-expressed with matrix metalloproteinases (MMPs), which are known to facilitate invasion and metastasis. MMP-2, MMP-7, and MMP-9 are co-expressed together with trypsin and seem to be of particular importance in proliferation, progression, and invasion. MMPs may play a role in both conversion from adenoma to carcinoma, and in the initiation of invasion and metastasis. Co-segregation of trypsin and MMPs within the tumour environment is important for the activation of MMPs, and may explain the deleterious effect of trypsin on prognosis in colorectal cancer. Trypsin and proteinase-activated receptor 2 (PAR-2) act together in an autocrine loop that promotes proliferation, invasion, and metastasis through various mechanisms, of which prostaglandin synthesis is important. Stimulated by trypsin, both MMP and PAR-2 may activate the mitogenic MAPK-ERK pathway through activation of the epidermal growth factor receptor. Experimental trypsin inhibition is feasible but not very effective, and trypsin as a target for clinical therapy is unlikely to be successful owing to its universal distribution. However, as the pathways of trypsin and co-activated protein cascades emerge, biological understanding of colorectal carcinogenesis will be further illuminated and may pave the way for prognosticators, predictors, and novel targets of therapy.     

Quantitative measurement of venous invasion of colorectal cancer with metachronous liver metastasis

Aims: Many studies have proven the importance of venous invasion in colorectal cancer with synchronous liver metastasis. The aim was to clarify the relationship between venous invasion and metachronous liver metastasis, which is not fully understood. Methods and results: A histological study of venous invasion in colorectal carcinoma was performed using a total of 156 patients, of whom 52 survived without recurrence for 5 years (Group A); 47 had metachronous liver metastasis (Group B), and 57 had synchronous liver metastasis (Group C). The number and the maximum area of venous invasion were estimated in each case per ×40 field of cancerous lesions, which were divided into intramural and extramural lesions. A high incidence and high average number of foci of venous invasion appeared in Groups B and C. The average maximum areas of extramural venous invasion were much larger in Groups B and C than in Group A. Conclusions: The average number of foci of venous invasion by colorectal cancer with metachronous liver metastasis did not differ significantly from that with synchronous ones. Furthermore, invasion into extramural large veins appeared to be associated with liver metastasis.     

Cyclooxygenase-2 expression in colorectal cancer liver metastases

Cyclooxygenase-2 (COX-2) is up-regulated in 85-90% of primary human colorectal cancers and is a putative target for the chemopreventative activity of non-steroidal anti-inflammatory drugs. However, COX-2 expression by human colorectal cancer liver metastases has been poorly characterized. We studied a consecutive series of 38 patients who underwent liver resection for metastatic disease, for whom long-term (up to 57 months), prospective follow-up data were available. Semi-quantitative immunohistochemistry for COX-2 was performed on 54 metastases from 35 patients, for whom adequate histological material was available. Diffuse cytoplasmic staining for COX-2 protein was detected in cancer cells in 100% of metastases (COX-2 score 1, n=25; score 2, n=29). There was no relationship between metastasis size or differentiation grade and the level of COX-2 protein expression. There was no difference in colorectal cancer-free or overall survival between patients with high (score 2) and low (score 1) COX-2 scores (Kaplan–Meier survival analysis and log rank test, both P=0.97). Multivariate Cox regression analysis identified age, incomplete resection and presence of extra-hepatic disease as independent predictors of disease-free and overall survival following surgery. COX-2 protein was also localized to a subset of stromal fibroblasts and mononuclear cells within metastases as well as hepatocytes from resection specimens. COX-2 protein was expressed by cancer cells in all human colorectal cancer liver metastases which were studied. Investigation of the effect of selective COX-2 inhibition on metastasis growth and metastasis cancer cell proliferation/apoptosis in vivo are warranted.