miR-422a is an independent prognostic factor and functions as a potential tumor suppressor in colorectal cancer

AIM: To determine the expression of miR-422a in colorectal cancer (CRC) tissues and to further explore the prognostic value and function of miR-422a in CRC carcinogenesis.METHODS: miR-422a expression was analyzed in 102 CRC tissues and paired normal mucosa adjacent to carcinoma by quantitative real-time PCR. The relationship of miR-422a expression with clinicopathological parameters was also analyzed. Kaplan-Meier analysis and Cox multivariate analysis were performed to estimate the potential role of miR-422a. Cell proliferation, migration, and invasion were used for in vitro functional analysis of miR-422a.RESULTS: The levels of miR-422a were dramatically reduced in CRC tissues compared with normal mucosa (P < 0.05), and significantly correlated with local invasion (P = 0.004) and lymph node metastasis (P < 0.001). Kaplan-Meier survival and Cox regression multivariate analyses revealed that miR-422a expression (HR = 0.568, P = 0.015) and clinical TNM stage (HR = 2.942, P = 0.003) were independent prognostic factors for overall survival in CRC patients. Furthermore, in vitro experiments showed that overexpression of miR-422a inhibited the proliferation, migration, and invasion of SW480 and HT-29 cells.CONCLUSION: Down-regulation of miR-422a may serve as an independent prognosis factor in CRC. MiR-422a functions as a tumor suppressor and regulates progression of CRC.     

Neuroendocrine differentiation is a relevant prognostic factor in stage III-IV colorectal cancer

OBJECTIVE: To determine the prognostic relevance of neuroendocrine differentiation in colorectal cancer. METHODS: The survival of 116 patients with colorectal cancer of stages III (n = 59) and IV (n = 57) was correlated with the extent of neuroendocrine differentiation. Chromogranin A and synaptophysin were used as neuroendocrine markers. Based on the degree of immunoreactivity for these markers, tumours were classified as 0 (no expression of neuroendocrine markers), 1 (< 2% cells staining positive for neuroendocrine markers) and 2 (> 2% cells staining positive for neuroendocrine markers). Patients were followed up for more than 5 years or until death. RESULTS: Seven of 59 (11.8%) stage III cancers and 13/57 (22.8%) stage IV cancers belonged to group 2. The 96 patients of groups 0 and 1 lived for 48.9 months, whereas the 20 patients of group 2 survived for only 18.6 months (Kaplan-Meier survival curves, P < 0.001). The difference was most striking in stage III disease with 79.4 months' survival for combined groups 0 and 1, and 38.9 months' survival for group 2 (P < 0.01). Using the multivariate Cox regression model, the presence of more than 2% of cells with neuroendocrine differentiation was found to be an independent prognostic parameter for stage III and IV disease. No correlation was observed between neuroendocrine differentiation and tumour location, grade, depth of invasion or stage. CONCLUSION: Neuroendocrine differentiation is often seen in colorectal cancer. It is an independent prognostic factor in stage III-IV colorectal cancer.     

Serum laminin is an independent prognostic factor in colorectal cancer

Purpose We investigated laminin, an important extracellular matrix component, to elucidate mechanisms of invasion and metastasis in colorectal cancer, and whether preoperative serum laminin is a predictive marker of high-risk groups.Methods We measured preoperative serum laminin levels using a two-step sandwich enzymeimmunassay (EIA) method in 205 patients with colorectal cancer, 109 with colon cancer and 96 with rectal cancer, 52 with hepatic metastases, and 153 with no hepatic metastases.Results Mean serum laminin in patients with colon cancer was 606.3±260.2 ng/ml, significantly higher than that of 258.0±92.0 ng/ml in normal controls (P<0.0001). The positive rate was higher at 89.3% for laminin vs. 38.0% for carcinoembryonic antigen (CEA) and 19.5% for CA19-9. Mean serum laminin in patients with hepatic metastases was 668.0±274.7 ng/ml, significantly higher than that of 585.2±252.5 ng/ml in patients without hepatic metastases (P=0.0472). Survival rates were significantly lower in the high (520 ng/ml) than in the low laminin group (<350 ng/ml; P=0.0451). Univariate and multivariate analysis, using Coxs proportional hazard regression model, showed serum laminin is an independent prognostic factor in colorectal cancer, along with hepatic, pulmonary and peritoneal metastases.Conclusion Preoperative serum laminin levels are a useful predictive marker of high-risk groups in colorectal cancer.     

Pleiotrophin promotes perineural invasion in pancreatic cancer

Perineural invasion(PNI)in pancreatic cancer is an important cause of local recurrence,but little is known about its mechanism.Pleiotrophin(PTN)is an important neurotrophic factor.It is of interest that our recent experimental data showed its involvement in PNI of pancreatic cancer.PTN strongly presents in the cytoplasm of pancreatic cancer cells,and high expression of PTN and its receptor may contribute to the high PNI of pancreatic cancer.Correspondingly,PNI is prone to happen in PTN-positive tumors.We thus hypothesize that,as a neurite growth-promoting factor,PTN may promote PNI in pancreatic cancer.PTN is released at the time of tumor cell necrosis,and binds with its highaffinity receptor,N-syndecan on pancreatic nerves,to promote neural growth in pancreatic cancer.Furthermore,neural destruction leads to a distorted neural homeostasis.Neurons and Schwann cells produce more N-syndecan in an effort to repair the pancreatic nerves.However,the abundance of N-syndecan attracts further PTN-positive cancer cells to the site of injury,creating a vicious cycle.Ultimately,increased PTN and N-syndecan levels,due to the continuous nerve injury,may promote cancer invasion and propagation along the neural structures.Therefore,it is meaningful to discuss the relationship between PTN/N-syndecan signaling and PNI in pancreatic cancer,which may lead to a better understanding of the mechanism of PNI in pancreatic cancer.     

Polo-like kinase 1 expression is a prognostic factor in human colon cancer

AIM: To clarify the expression patterns and prognostic implications of the mitotic regulator Polo-like kinase 1 (PLKl) in colon cancer. METHODS: Expression of PLKl was investigated by immunohistochemistry (158 cases) and immunoblotting in tissue of colon adenomas and adenocarcinomas. PLKl expression patterns were correlated with clinicopathological parameters and patient prognosis. In addition, expression of PLKl was evaluated by immunoblot and PCR in colon carcinoma cell lines, and coexpression of PLKl with the proliferation marker Ki-67 was investigated. RESULTS: Weak PLKl expression was observed in normal colon mucosa and adenomas. In contrast, 66.7% of carcinomas showed strong expression of PLKl. Overexpression of PLKl correlated positively with Dukes stage (P<0.001), tumor stage (P= 0.001) and nodal status (P<0.05). Additionally, PLKl expression was a prognostic marker in univariate survival analysis (P<0.01) and had independent prognostic significance (RR = 3.3, P= 0.02) in patients with locoregional disease. Expression of PLKl mRNA and protein was detected in all cell lines investigated. Coexpression of PLKl and Ki-67 was observed in the majority of colon cancer cells, but a considerable proportion of cells showed PLKl positivity without Ki-67 expression. CONCLUSION: PLKl is a new prognostic marker for colon carcinoma patients and may be involved in tumorigenesis and progression of colon cancer. Strategies focusing on PLKl inhibition in vivo might therefore represent a promising new therapeutic approach for this tumor entity.     

Deficient mismatch repair phenotype is a prognostic factor for colorectal cancer in elderly patients

ObjectiveAbout 15% of colorectal adenocarcinomas have a deficient DNA mismatch repair phenotype. The frequency of deficient DNA mismatch repair tumours increases with age due to the hypermethylation of hMLH1 promoter. The study aimed to determine the prognostic value of deficient DNA mismatch repair phenotype in elderly patients.DesignMismatch repair phenotype was retrospectively determined by molecular analysis in consecutive resected colorectal adenocarcinoma specimens from patients over 75 years of age from 4 Oncology centres.Results231 patients (median age: 81, range: 75–100) were enrolled from 2005 to 2008. Mean prevalence of deficient DNA mismatch repair phenotype was 22.5%, and 36% for patients over 85 years. Deficient DNA mismatch repair status was significantly associated with older age, female sex, proximal colon primary and high grade tumour. For stage II tumours no deficient DNA mismatch repair tumours had a recurrence at end of follow-up compared to 17% for tumours with proficient phenotype. The proficient phenotype status was significantly associated with worse age-adjusted overall survival [HR 2.60; 95% CI 1.05–6.44; p = 0.039]. For stage III tumours a trend for less recurrence was observed for deficient DNA mismatch repair phenotype (16%) compared to proficient phenotype (36%).Conclusiondeficient DNA mismatch repair phenotype is a prognostic factor in stage II colorectal tumour in elderly patients. Our results suggest that mismatch repair phenotype should be taken in consideration for adjuvant chemotherapy decision in elderly patients.     

Cyclooxygenase－2 expression and angiogenesis in colorectal cancer

AIM: Cyclooxygenase-2 is involved in a variety of important cellular functions, including cell growth and differentiation,cancer cell motility and invasion, angiogenesis and immune function. However, the role of cyclooxygenase-2 as an angiogenic factor in colorectal cancer tissue is still unclear.We investigated the relationship between cyclooxygenase2 and angiogenesis by analyzing the expression of cyclooxygenase-2 in colorectal cancer tissue, as well as its association with vascular endothelial growth factor (VEGF)and microvascular density (MVD). METHODS: The expression of cydooxygenase-2, VEGF, as well as MVD was detected in 128 cases of colorectal cancer by immunohistochemical staining. The relationship between the cydooxygenase-2 and VEGF expression and MlVD was evaluated.Our objective was to determine the effect of cyclooxygenase2 on the angiogenesis of colorectal cancer tissue. RESULTS: Among 128 cases of colorectal cancer, 87 were positive for cyclooxygenase-2 (67.9 %), and 49 for VEGF (38.3 %), respectively. The microvessel counts ranged from 23 to 142, with a mean of 51.7 (standard deviation, 19.8). The expression of cydooxygenase-2 was correlated significantly with the depth of invasion, stage of disease, metastasis (lymph node and liver), VEGF expression and MlVD. Patients in T3-T4, stage Ⅲ-ⅣV and with metastasis had much higher expression of cydooxygenase-2 than patients in T1-T2, stage Ⅰ-Ⅱ and without metastasis (P＜0.05). 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). Also, the microvessel count (56±16) in cyclooxygenase-2 positive group was significantly higher than that in cyclooxygenase-2 negative group (43±12, P＜0.05). The microvessel count in tumors with positive cyclooxygenase-2and VEGF was the highest (60±18, 41-142, P＜0.05), whereas that in tumors with negative cyclooxygenase-2 and VEGF wasthe lowest (39±16, 23-68, P＜0.05). CONCLUSION: Cyclooxygenase-2 may be associated with tumor progression by madulating the angiogenesis in colorectal cancer tissue and used as a possible biomarker.     

High expression of anti-apoptotic protein Bcl-2 is a good prognostic factor in colorectal cancer: Result of a metaanalysis

AIM To systematically evaluate the prognostic-predictive capability of Bcl-2 in colorectal cancer(CRC).METHODS A systematic literature search was conducted using Pub Med,Web of Science and EMBASE databases. Any eligible study must meet the following criteria:(1) bcl-2 expression was evaluated in human CRC tissues by immunohistochemistry;(2) assessment of the relationships between bcl-2 expression and overall survival(OS),disease free survival(DFS),recurrent free survival(RFS) or clinic-pathological characteristics of CRC was included;(3) sufficient information was provided to estimate the hazard ratio(HR) or odds ratio and their 95% confidence intervals(CIs); and(4) the study was published in English. The impact of Bcl-2 expression on survival of CRC patients were evaluated through this meta-analysis.RESULTS A total of 40 eligible articles involving 7658 patients were enrolled in our final analysis. We drew the conclusion that Bcl-2 high expression was significantly correlated with favorable OS(pooled HR = 0.69,95%CI: 0.55-0.87,P = 0.002) and better DFS/RFS(pooled HR = 0.65,95%CI: 0.50-0.85,P = 0.001). Additionally,the subgroup analysis suggested that Bcl-2 overexpression was significantly associated withprognosis(OS) especially in patients came from Europe and America but not Asian and patients who did not receive any adjuvant therapy before surgery. Finally,our present results indicated that expression of bcl-2 protein was associated with high differentiation grade and A/B Ducks' stage. CONCLUSION Bcl-2 high expression was significantly correlated with favorable OS and better DFS/RFS. Hence,we propose that Bcl-2 may be a valuable prognostic-predictive marker in CRC.     

Expression of tissue factor and vascular endothelial growth factor is associated with angiogenesis in colorectal cancer

We examined the expression of tissue factor (TF) and vascular endothelial growth factor (VEGF) and the microvessel density (MVD) in 100 patients with colorectal cancer, and we investigated the relationship of the expression of TF or VEGF with angiogenesis. TF antigen was positive in 57.0% of all specimens. Incidence of TF expression was 41.2%, 45.5%, 52.6%, 84.6%, and 81.3% in tumors from patients in clinical stages I, II, IIIA, IIIB, and IV, respectively. TF expression was correlated with the Dukes' classification (P = 0.01) and the clinical stage of colorectal cancer (P = 0.02). VEGF antigen was positive in 64.0% of all specimens. Incidence of VEGF expression was 41.2%, 57.6%, 73.7%, 84.6%, and 75.0% in tumors from patients in clinical stages I, II, IIIA, IIIB, and IV, respectively. VEGF expression was correlated with the Dukes' classification (P = 0.01) but showed a weak association with the clinical stage (P = 0.08). MVD was significantly associated with the depth of invasion (P = 0.01), lymph node metastasis (P = 0.001), and liver metastasis (P = 0.02). The mean values of MVD were 7.5 +/- 2.8, 10.1 +/- 5.7, 14.6 +/- 5.8, 13.5 +/- 3.9, and 15.9 +/- 4.2 in tumors from patients in clinical stages I, II, IIIA, IIIB, and IV, respectively. A close relationship between VEGF and MVD (P < 0.001) and a significant correlation between TF expression and MVD were observed (P = 0.02). TF-positive carcinomas presented high MVD and VEGF expression (P < 0.001) more frequently than did TF-negative tumors. These results suggest that involvement of TF in the process of metastasis and progression of colorectal cancer may depend on increased angiogenesis.     

Upregulation of nemo-like kinase is an independent prognostic factor in colorectal cancer

AIM: To investigate the expression and oncogenic role of nemo-like kinase(NLK) in colorectal cancer.METHODS: Expression of NLK protein was assessed by immunohistochemistry in tissue specimens from 56 cases of normal colorectal mucosa, 51 cases of colorectal adenoma, and 712 cases of colorectal cancer. In addition, NLK expression was knocked down using a lentivirus carrying NLK small hairpin RNA in colorectal cancer cells. Cell viability methylthiazoletetrazolium assays, colony formation assays, flow cytometry cell cycle assays, Transwell migration assays, and gene expression assays were performed to explore its role on proliferation and migration of colorectal cancer.RESULTS: Expression of NLK protein progressively increased in tissues from the normal mucosa through adenoma to various stages of colorectal cancer. Overexpression of NLK protein was associated with advanced tumor-lymph node-metastasis stages, poor differentiation, lymph node and distant metastases, and a higher recurrence rate of colorectal cancer(P 0.05). Multivariate analyses showed that NLK expression was an independent prognostic factor to predict overallsurvival(hazard ratio 2.57, 95% confidence interval: 1.66-3.98; P 0.001) and disease-free survival(hazard ratio 1.96, 95% confidence interval: 1.40-2.74: P 0.001) of colorectal cancer patients. Furthermore, knockdown of NLK expression in colorectal cancer cell lines reduced cell viability, colony formation, and migration, and arrested tumor cells at the G0/G1 phase of the cell cycle. At the gene level, knockdown of NLK expression inhibited matrix metalloproteinase-2 expression in colorectal cancer cells. CONCLUSION: NLK overexpression is an independent prognostic factor in colorectal cancer and knockdown of NLK expression inhibits colorectal cancer progression and metastasis.     

MicroRNAs as a potential prognostic factor in gastric cancer

AIM:To compare the microRNA (miR) profiles in the primary tumor of patients with recurrent and non-recurrent gastric cancer.METHODS:The study group included 45 patients who underwent curative gastrectomies from 1995 to 2005 without adjuvant or neoadjuvant therapy and for whom adequate tumor content was available.Total RNA was extracted from formalin-fixed paraffin-embedded tumor samples,preserving the small RNA fraction.Initial profiling using miR microarrays was performed to identify potential biomarkers o...     

HER-2/neu overexpression is an independent prognostic factor in colorectal cancer

Background and aims The HER-2/neu protein is intimately involved with normal cell proliferation and tissue growth, as it is extensively homologous and is related to the epidermal growth factor receptor. This phenomenon has been most intensively studied in the context of breast carcinoma, in which its amplification and overexpression correlate with the overall course of disease and poor prognoses, and also constitute a predictive factor of poor response to chemotherapy and endocrine therapy. In this study, we investigated the relationships between the expression of HER-2/neu and the clinicopathological characteristics of colorectal cancer, including survival. This study was performed with a view toward the future introduction of Herceptin therapy for colorectal cancer patients. Patients and methods HER-2/neu overexpression and gene amplification were examined via semiquantitative standardized immunohistochemical staining and fluorescence in situ hybridization (FISH) in 137 colorectal cancer patients who underwent curative surgery at the Kangbuk Samsung Hospital. Results Sixty-five (47.4%) out of 137 patients were determined by immunohistochemistry to have overexpressed HER-2/neu protein. HER-2/neu gene amplification was detected in two patients by FISH. Tumors with HER-2/neu overexpression showed higher postoperative recurrence rate (39.3% vs 14.6%, p=0.013). Tumors with HER-2/neu overexpression were associated with poor 3-year (70.8% vs 83.7%) and 5-year survival rates (55.1% vs 78.3%, p<0.05). Advanced TNM stage, postoperative recurrence, and overexpression of HER-2/neu were found to be independently related to survival by multivariate analysis. Conclusion HER-2/neu overexpression may constitute an independent prognostic factor in colorectal cancer patients, and patients exhibiting HER-2/neu overexpression might constitute potential candidates for a new adjuvant therapy which involves the use of humanized monoclonal antibodies.     

Nuclear β-catenin expression as a prognostic factor in advanced colorectal carcinoma

AIM： To investigate the changing pattern of β-catenin expression and its prognostic value in advanced colorectal cancer （CRC）. METHODS： Archival tumor samples were analyzed for β-catenin using immunohistochemistry （IHC） in 95 patients with advanced CRC. RESULTS： Membranous β-catenin expression was found in the normal colorectal epithelium. Almost 100% of CRC cases showed membranous and cytoplasmic expression, and 55 （58%） cases showed nuclear expression. In univariate （Kaplan-Meier） survival analysis, only the nuclear index （NI） was a significant predictor of disease free survival （DFS） （P = 0.023; n = 35）, with a NI above the median associated with longer DFS （34.2 too） than those with a NI below the median （15.5 too） （P = 0.045, ANOVA）. The other indices were not significant predictors of DFS, and none of the three tested indices （for membranous, cytoplasmic, or nuclear expression） predicted diseasespecific survival （DSS）. However, when dichotomized as positive or negative nuclear expression, the former was a significant predictor of more favorable DFS （P = 0.041） and DSS （P = 0.046）. CONCLUSION： Nuclear β-catenin expression provides additional information in predicting patient outcome in advanced CRC.     

Pleiotrophin, a multifunctional angiogenic factor: mechanisms and pathways in normal and pathological angiogenesis

PURPOSE OF REVIEW: This study seeks to integrate recent studies that identify new critical mechanisms through which the 136 amino acid secreted heparin-binding cytokine pleiotrophin (PTN, Ptn) stimulates both normal and pathological angiogenesis. RECENT FINDINGS: Pleiotrophin is directly angiogenic; it initiates an angiogenic switch in different cancer models in vivo. It acts as an angiogenic factor through multiple mechanisms that include a unique signaling pathway that activates newly identified downstream tyrosine kinases through a unique mechanism, an interaction with endothelial cells to initiate proliferation, migration, and tube formation, the regulation of basic fibroblast growth factor and vascular endothelial growth factor signaling, the remodeling of the stromal microenvironment, and induction of transdifferentiation of monocytes into endothelial cells. Recently also, domains of PTN that stimulate angiogenesis and peptides that function to inhibit PTN signaling have been identified. SUMMARY: Recent studies have identified new mechanisms dependent on activation of the PTN signaling pathway that regulate angiogenesis and new targets to use PTN to both stimulate angiogenesis and block its activity to control pathological angiogenesis.     

Fas/CD95 signaling rather than angiogenesis or proliferative activity is a useful prognostic factor in patients with resected liver metastases from colorectal cancer

Background The selection of resective therapy for colorectal hepatic metastases remains controversial. The aim of this study is to investigate the prognostic factors for patients with resected liver metastases from colorectal cancer by analyzing not only clinicopathological factors but also recent immunohistological markers.Methods Eighty-five patients underwent hepatic resection for metastatic colorectal cancer over the past 20 years. Fas/CD95 expression, microvessel density, and proliferating cell nuclear antigen (PCNA) proliferative activity were assessed with immunohistochemical methods in addition to the clinicopathological factors. Survival analysis was performed using the Kaplan–Meier method and Cox proportional hazards model, both univariately and multivariately.Results Univariate and multivariate analyses revealed that the number of metastases, Fas/CD95 expression, and postoperative carcinoembryonic antigen doubling time (CEADT) were significant prognostic indicators, whereas the mode of hepatic resection, chemotherapy, and other clinicopathological factors had no influence on survival. Fas/CD95 index correlated with postoperative CEADT (p=0.039), number of metastases (p=0.018), and survival (p=0.023).Conclusions Our study confirmed the number of metastases and CEADT as prominent prognostic factors after hepatic resection for metastatic colorectal cancer. These two factors reflect the degree of Fas/CD95 signaling rather than angiogenesis or cancer growth rate.This work was presented at the meeting of The American Society of Colon and Rectal Surgeons, New Orleans, June 23 to 25, 2003     

Pleiotrophin is a neurotrophic factor for spinal motor neurons

Regeneration in the peripheral nervous system is poor after chronic denervation. Denervated Schwann cells act as a "transient target" by secreting growth factors to promote regeneration of axons but lose this ability with chronic denervation. We discovered that the mRNA for pleiotrophin (PTN) was highly up-regulated in acutely denervated distal sciatic nerves, but high levels of PTN mRNA were not maintained in chronically denervated nerves. PTN protected spinal motor neurons against chronic excitotoxic injury and caused increased outgrowth of motor axons out of the spinal cord explants and formation of "miniventral rootlets." In neonatal mice, PTN protected the facial motor neurons against cell death induced by deprivation from target-derived growth factors. Similarly, PTN significantly enhanced regeneration of myelinated axons across a graft in the transected sciatic nerve of adult rats. Our findings suggest a neurotrophic role for PTN that may lead to previously unrecognized treatment options for motor neuron disease and motor axonal regeneration.