Prognostic Value of Raf Kinase Inhibitor Protein in Esophageal Squamous Cell Carcinoma

Raf kinase inhibitory protein (RKIP, also PEBP1) is involved in regulation of multiple cellular signaling processes and suppressing metastasis in animal models. Downregulation of RKIP expression has been shown to promote tumor progression in a variety of human cancers. However, its role and clinical significance in resectable esophageal squamous cell carcinoma (ESCC) is still scanty. The purpose of this study was to investigate the prognostic significance of RKIP expression by immunohistochemistry in a group of patients with ESCC treated with surgical resection. RKIP expression in 233 surgically resected ESCC specimens and 49 cases of adjacent normal tissues was detected by using immunohistochemical staining. The clinical and prognostic significance of RKIP expression was statistically analyzed. Kaplan-Meier analysis was used to compare the postoperative survival between groups. Significant downregulation was noted for RKIP protein in ESCCs, compared to adjacent normal tissues (p < 0.001). A lower disease-free survival and overall survival of ESCC was found in patients whose tissues had low RKIP expression (both P < 0.001). In addition, RKIP expression could stratify the patient survival (disease-free survival/overall survival) in stage II (P = 0.01 and 0.02, repectively). The Cox proportionate hazard regression model also established that low expression of RKIP was significantly correlated with increased risk (RR = 3.572) of recurrence compared with high RKIP expression (P < 0.001). Furthermore, the results of multivariate analysis suggested that RKIP expression (P < 0.001) was an independent factor that affected overall survival. These findings suggest that the low expression of RKIP be associated with poor survival in resectable ESCC patients.     

Angiogenesis and Survival in Patients with Myelodysplastic Syndrome

Angiogenesis has been implicated in the pathogenesis and prognosis of myelodysplastic syndrome (MDS). In this study, we investigated the relationship between microvessel density (MVD), vascular endothelial growth factor (VEGF) expression, common morphological and clinical factors, and survival in patients with MDS. We examined the MVD of paraffin-embedded bone marrow sections from 70 MDS patients and 31 controls. VEGF expression was determined in 50 patients and 20 controls. The median MVD in MDS patients was significantly higher than that in controls (p = 0.025), whereas there was no difference in VEGF expression between MDS patients and controls. In univariate analysis, increased MVD was associated with a shorter survival time (p = 0.023). However, in multivariate analysis, MVD was not an independent predictor of survival. The VEGF expression did not influence survival in univariate analysis. Survival was independently influenced by platelet count (p = 0.0073), cytogenetic risk category (p = 0.022), and transfusion dependence (p = 0.0073). Neither MVD nor VEGF expression were predictors for progression to acute myeloid leukemia in univariate analysis. Progression to acute myeloid leukemia was independently influenced only by the cytogenetic risk category (p = 0.022). This study confirmed increased MVD in MDS. It does not support an independent prognostic role of angiogenesis in MDS.     

Clusterin as a Diagnostic and Prognostic Marker for Transitional Cell Carcinoma of the Bladder

We investigated the feasibility of profiling and measuring the concentration of clusterin in urine and serum for individuals with transitional cell carcinoma (TCC) of the bladder and comparing it with nontumor controls. In addition, we analyzed the correlation of expression of clusterin in specimens of TCC to various clinicopathologic parameters and prognosis of bladder cancer. Blood and urine samples were used from 68 patients with TCC of the bladder and from 61 patients with benign urological diseases. Enzyme-linked immunosorbent assays (ELISA) were performed for clusterin from serum and urine. Quantitation of clusterin mRNA was carried out in 68 bladder tumor specimens from radical cystectomy or transurethral resection and 26 normal bladder specimens from BPH patients by using RT-PCR method. Correlation for the expression of clusterin mRNA with clinicopathologic parameters was analyzed. Serum and urine clusterin was significantly higher in individuals with bladder cancer than control (p = 0.001). Sensitivity and specificity of serum and urine clusterin as a tumor marker for TCC of the bladder was found to be 80%, 91%, 87.1% and 96.7% respectively. Clusterin expression was significantly higher in TCC specimens than normal tissue specimens (P < 0.001). Expression of clusterin was significantly higher in patients with invasive TCC of the bladder than that in patients with superficial TCC and control (P < 0.001). Overexpression of clusterin mRNA was significantly associated with tumor recurrence and overall survival (p < 0.001). The recurrence-free survival time of patients with overexpression of clusterin was significantly shorter than that of patients with weak expression of clusterin (9.8 months vs. 35.2 months). Clusterin may be considered as a potential diagnostic and prognostic biomarker for bladder cancer using urine, serum and/or molecular biology techniques.     

Upregulation of Bone Morphogenetic Protein 4 is Associated with Poor Prognosis in Patients with Hepatocellular Carcinoma

Bone morphogenetic protein (BMP) 4 plays a crucial role in tumor invasion and metastasis of various human cancers. However, little is known about the correlation of BMP4 expression with clinical aggressiveness and prognosis in hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression of BMP4 in HCC and determine its correlation with tumor progression and prognosis. Immunohistochemistry assay was used to determine the expression of BMP4 in HCC and corresponding paracarcinomatous tissues from 156 patients. The potential prognostic value of BMP4 was investigated by comparing the survival rates between the BMP4-positive and BMP4-negative HCC patients. Immunohistochemically, BMP4 protein expression in the HCC tissues (120/156, 76.9%) was significantly higher than that in the paracarcinomatous tissues (19/156, 12.2%, P < 0.01). The expression of BMP4 in HCC was associated with number of tumor nodules (P = 0.02), Edmondson grade (P = 0.03), TNM stage (P = 0.009), and vascular invasion (P = 0.006). In univariate survival analysis, the significant associations of the BMP4 protein overexpression with shortened patients’ overall and disease-free survival were found (P = 0.001 and 0.006, respectively). Furthermore, its expression was found to be an independent factor for predicting both overall (P = 0.009) and disease-free survival (P = 0.022) of HCC in multivariate analysis. Our data suggest for the first time that BMP4 is overexpressed in HCC tissues and may also act as a novel marker for predicting the recurrence and prognosis of HCC patients after surgery.     

Expression of Y-Box-binding protein 1 in Chinese patients with breast cancer

The purpose of this study was to investigate the expression of Y-Box-binding protein 1 (YB-1) in breast cancer and its correlation with clinicopathological characteristics and prognosis. Paraffin sections were retrospectively collected from 239 cases of stage I–III breast cancer patients and 30 healthy females who received surgery between January 2000 and December 2004 in the Chinese People’s Liberation Army General Hospital. The protein expression of YB-1 was detected by immunohistochemistry. The expression difference between the two groups and the correlation between YB-1 expression and clinicopathological characteristics and breast cancer prognosis were analyzed. Within the breast cancer group, YB-1 was expressed in the cytoplasm in 100.0% (239/239) of cases and in the nucleus in 36.8% (88/239) of cases. Within the control group of normal breast tissue, YB-1 was expressed in the cytoplasm in 100.0% (30/30) of cases and in the nucleus in 16.7% (5/30) of cases. The expression of YB-1 in the nucleus of breast cancer cells was significantly higher than that in normal breast tissue (P = 0.029). The expression of YB-1 in the nucleus of breast cancer cells positively correlated with the Scarff–Bloom–Richardson grade (P = 0.007) and HER-2 expression (P = 0.005), negatively correlated with ER expression (P = 0.004), and was independent of the age, menstrual status, pathological type, tumor size, lymph node status, presence of thrombosis, PR expression, and EGFR expression. The 5-year disease-free survival (DFS) and overall survival (OS) of patients with positive YB-1 expression in the nucleus were significantly lower than those of patients who were negative for nuclear YB-1 expression, and the difference was statistically significant (DFS 65.9% vs. 82.1%, P = 0.000; OS 79.5% vs. 92.1%, P = 0.000). Multivariate analysis suggested that the expression of YB-1 in the nucleus is an independent prognostic factor that affects DFS and OS in breast cancer patients (DFS P = 0.015; OS P = 0.035). In conclusion, the expression of YB-1 in the nucleus is related to carcinogenesis and the development of breast cancer. Therefore, YB-1 is an important molecular marker that can be used to predict breast cancer prognosis.     

Implication of RAF and RKIP Genes in Urinary Bladder Cancer

RKIP has been shown to regulate the RAS-RAF-MEK-ERK kinase cascade acting as modulator of apoptosis and metastasis in prostate cancer. Our goal was to examine the expression of the RAF (A-RAF, B-RAF and RAF-1) and RKIP genes in urinary bladder cancer. Microarray analysis and qPCR was employed to investigate the expression of RAF and RKIP, in 30 patients with transitional cell carcinoma (TCC) of the urinary bladder vs. the corresponding levels of adjacent normal tissue. Computational analysis was also performed on Gene Expression Omnibus (GEO) datasets, to unravel differences in the expression of RAF or RKIP between tumor and control samples, and between superficial and muscle invasive tumors. Microarray analysis revealed >2-fold expression of BRAF and RKIP in T2, T3, grade III tumors vs. controls. B-RAF over-expression was verified by qPCR in pT1, grade III tumors vs. their normal counterparts (p = 0.016). qPCR revealed a significant RKIP reduction in TCC vs. normal tissue (p = 0.002 and p < 0.001 for T1, grade II and Ta-T1, grade III, respectively); All RAF genes were positively correlated among each other (A-RAF/B-RAF, p = 0.003; A-RAF/RAF-1, p < 0.001; B-RAF/RAF-1, p = 0.050), whereas B-RAF was negatively correlated with RKIP in TCC (p = 0.050). Further computational analysis revealed different expression profiles for the genes of interest, among muscle invasive carcinomas, superficial TCCs, cystectomy specimens and normal tissue. The reduced RKIP mRNA levels in TCC and the elevated levels of B-RAF in pT1, grade III tumors vs. normal tissue, corroborate that these genes are involved in the pathogenesis of urinary bladder cancer.     

Expression and Clinical Significance of Focal Adhesion Kinase in the Two Distinct Histological Types, Intestinal and Diffuse, of Human Gastric Adenocarcinoma

Focal adhesion kinase (FAK), a non-receptor tyrosine kinase protein, acts as an early modulator of integrin signaling cascade, regulating basic cellular functions. In transformed cells, unopposed FAK signaling has been considered to promote tumor growth, progression and metastasis. The aim of this study was to assess the clinical significance of FAK expression in the two distinct histological types of human gastric neoplasia. FAK expression was assessed immunohistochemically in tumoral samples of 66 gastric adenocarcinoma cases, 30 intestinal and 36 diffuse type, and was statistically analyzed in relation to various clinicopathological characteristics, tumor proliferative capacity and patients’ survival. In intestinal type carcinomas, enhanced FAK expression was significantly associated with increased tumor proliferative capacity (P = 0.012). In diffuse type carcinomas, FAK staining intensity was significantly correlated with tumor size (P = 0.026) and disease stage (P = 0.024), presenting also a borderline association with nodal status (P = 0.053). In diffuse type carcinomas, enhanced FAK expression was significantly associated with longer overall survival times (log-rank test, P = 0.014), being also identified as an independent prognostic factor in multivariate analysis (Cox regression, P = 0.016). In contrast, patients with intestinal type tumors and enhanced FAK expression were characterized by shorter overall survival times, without though reaching statistical significance (log-rank test, P = 0.092). The current data support evidence that FAK protein may be considered as a diagnostic and prognostic marker in gastric neoplasia. Further studies conducted on larger clinical samples and highlighting on the distinct impact of the two histological types are warranted to delineate the clinical significance of FAK protein in gastric neoplasia.     

Prognostic and predictive values of pERK1/2 and pAkt-1 expression in non-small cell lung cancer patients treated with adjuvant chemotherapy

Ras/ERK and PI3K/Akt pathways are reported to play a prognostic role and contribute to drug resistance in many cancers. The objective of this study was to explore associations between the expression levels of several molecules in Ras/ERK and PI3K/Akt pathways and their clinical significance in predicting the effectiveness of postoperative adjuvant chemotherapy in patients with non-small cell lung cancer (NSCLC). The expressions of K-ras, Raf-1, ERK1/2, phosphorylated ERK1/2 (pERK1/2), Akt-1, phosphorylated Akt-1 (pAkt-1), and Bcl-2 were detected by immunohistochemistry in tumor specimens from 144 NSCLC patients. The correlations between the expression levels of these molecules and the clinicopathological characteristics were analyzed. Patient survival was analyzed by Kaplan–Meier method, log-rank test, and Cox regression. The positive expression rates of K-ras, Raf-1, ERK1/2, pERK1/2, Akt-1, pAkt-1, and Bcl-2 were 21.5%, 41.7%, 59.7%, 27.1%, 50.7%, 36.1%, and 30.6%, respectively. Univariate analysis showed that patients with pERK1/2-positive (P = 0.01), Bcl-2-positive (P = 0.023), or pAkt-1 negative (P = 0.021) had significantly better recurrence-free survival (RFS) than those with pERK1/2-negative, Bcl-2-negative, or pAkt-1-positive. Multivariate analysis showed that earlier stage (P ≤ 0.001), non-adenocarcinoma (P ≤ 0.001), pERK1/2-positive (P ≤ 0.001), and pAkt-1-negative (P = 0.016) were independent prognostic factors for a better RFS in NSCLC. pERK1/2-positive and pAkt-1-negative proved to contribute to a better RFS in postoperative NSCLC patients who received adjuvant chemotherapy after taking the stage and histological subtype into account. pERK1/2 and pAkt-1 could be considered as new independent prognostic biomarkers for predicting RFS and selecting patients who are more likely to benefit from postoperative adjuvant chemotherapy.     

Abnormal Expression of Adhesion Protein Bves is Associated with Gastric Cancer Progression and Poor Survival

Although many molecular and biological studies have shown risk factors for gastric cancer, the available knowledge is still insufficient to unveil the exact mechanism of gastric cancer. To investigate the relationships between Bves expression and the clinicopathologic features of gastric cancer and whether Bves can act as prognostic indicators in gastric cancer. Tissues were obtained from the gastrectomy specimens of 306 human gastric cancer and 78 noncancerous gastric tissue at the Department of Surgery and Pathology, the Second Affiliated Hospital of Kunming Medical University from February 1996 to March 2007. The method of immunohistochemistry was used to investigate the expression of Bves in them. The relationship between Bves expression and the survival times of the patients was retrospectively analysed. Reduced expression of Bves frequently occurred in gastric cancer tissue. Low expression of Bves correlated with histologic differentiation, depth of invasion, regional lymph nodes and distant metastasis, and TNM stages (P < 0.05). Bves expression did not correlate with age, gender, location of tumor, size of tumor and histologic type (P > 0.05); Further multivariate analysis revealed that lymph node metastasis (P < 0.0001), distant metastasis (P < 0.0001), surgical treatment (P < 0.0001), and the expression of Bves (P < 0.0001) were independent prognostic factors in patients with gastric cancer; The Kaplan-Meier plot showed that survival times of patients with low Bves expression was significantly lower than those in patients with high Bves expression. Besides, low Bves expression had a much more significant effect on the survival of those patients with early stage tumors (χ2 = 131.216,P < 0.0001), highlighted by a >51.3% reduction in 3-year survival compared with that of patients with high Bves expression. In late stages, the difference was also significant (χ2 = 5.818,P = 0.016), with a 34.8% reduction in 3-year survival. Reduced expression of Bves in gastric cancer is associated with tumor progression and the patient’s poor survival. This study showed that the studied protein has further provided a basis for the development of potential biomarker for gastric cancer prognosis.     

Overexpression of G6PD is associated with poor clinical outcome in gastric cancer

This study aims to investigate the expression and significance of glucose-6-phosphate dehydrogenase (G6PD) in human gastric cancer progression and prognosis. Using immunohistochemistry and real-time RT-PCR assay, we identified abnormally elevated expression of G6PD in gastric cancer tissues compared to paired normal stomach mucosa tissues in 24 patients (p < 0.05). In order to investigate the correlations between G6PD and the clinicopathological features of gastric cancer, the expression of G6PD in 167 patients with gastric cancer were detected by immunohistochemistry, and the results showed that overexpression of G6PD was associated with the size of tumor (p = 0.039), depth of invasion (p = 0.039), lymph node metastasis (p = 0.044), distant metastasis (p = 0.003), TNM stage (p = 0.030), and survival rate (p = 0.010). Further, Cox multivariates analysis indicated that G6PD expression level was an independent prognostic factor for patients after radical resection (p = 0.013). In conclusion, overexpression of G6PD is closely related to progression of gastric cancer, and might be regarded as an independent predictor of poor prognosis for gastric cancer.     

CDH13 and FLBN3 Gene Methylation are Associated with Poor Prognosis in Colorectal Cancer

The aim of this study was to identify potential epigenetic prognostic biomarkers for colorectal cancer (CRC) in the Chinese population. The methylation status of five tumor suppressor genes (CDH13, DLEC1, FBLN3, hMHL1 and RUNX3) was determined using manual microdissection followed by methylation-specific PCR in 85 paired CRC specimens and adjacent normal tissue. The results showed that methylation frequencies in cancerous tissues were 31.8% for CDH13, 37.6% for DLEC1, 38.8% for FBLN3, 22.4% for hMHL1 and 27.1% for RUNX3, all of which were significantly higher than in corresponding normal tissue. Furthermore, CDH13 methylation was associated with poor differentiation (P = 0.019) and tended to be predominant in advanced stages (P = 0.084); FBLN3 methylation was associated with advanced stages (P = 0.027) and lymph node metastasis (P = 0.029). Accordingly, the methylation status of CDH13 (P = 0.022), FBLN3 (P = 0.008), CDH13 and/or FBLN3 (P = 0.001) predicted adverse overall survival in CRC, while hMHL1 methylation showed a protective role in survival (P = 0.046). Cox proportional hazard models further indicated that CDH13 and/or FBLN3 methylation, but not that of hMHL1, was an independent prognostic factor for CRC. In conclusion, we found CDH13 and FBLN3 gene methylation are potential biomarkers for poor prognosis in CRC.     

HER2/neu Expression: A Predictor for Differentiation and Survival in Children With Wilms Tumor

Wilms tumor is a mixed embroynal neoplasm of the kidney . HER2 is an onco-protein. Its over-expression could be implicated in the development of many tumors. The clinico-demographic and pathological data of 28 Wilms tumor patients were , reviewed. The tissue samples were examined by light Microscopy then immunohistochemical staining for HER2/neu expression. Additional 28 normal surrounding renal tissue specimens were included. There was significant differences between HER2/neu positive and HER2/neu negative Wilms tumors in relation to stage, histological phase and epithelial differentiation (P > 0.05 for all). The overall survival advantage was noticed if Wilms tumor was at early stages (I and II) (Log-rank = 13.23 and P > 0.001), homologous epithelial differentiation (Log-rank = 6.01 and P = 0.04), as well as HER2/neu positive tumors (Log-rank = 6.14 and P = 0.013). A statistical significant trend toward a longer recurrence free survival was, noticed if Wilms tumor was at early stages (Log-rank = 21.22, P > 0.0000) and if HER2/neu positive (Log-rank = 8.53, P = 0.004). HER2/neu expression in Wilms tumor could be a marker for epithelial and homologous differentiation and its expression could be a good predictor for overall survival and longer recurrence free survival.     

K-ras Mutation,HPV Infection and Smoking or Alcohol Abuse Positively Correlate with Esophageal Squamous Carcinoma

The Ras/Raf/MEK/ERK (MAPK) signal transduction cascade is an important mediator of a number of cellular fates including growth, survival and apoptosis. The aim of this study was to determine the incidence of B-raf, Kirsten-ras (K-ras) and Neuroblastoma-ras (N-ras) gene mutations in esophageal squamous cell carcinoma (ESCC) in the Greek population. DNA was extracted from 30 ESCC and 32 normal esophageal specimens and screened for V600E B-raf, and K-ras/N-ras codon 12 mutations, by PCR-RFLP based analysis. Among the genes tested, only the heterozygous K-ras mutation was detected in 5 out of the 30 ESCC specimens (16%), whereas no mutation was found in the normal esophageal tissue (P < 0.022). The normal samples were screened negative for N-ras and V600E B-raf mutations. The increased risk of esophageal cancer was correlated with tobacco use (OR = 3.5, P < 0.023) and alcohol abuse (OR = 7.22, P < 0.001), accompanied with the high incidence of the k-ras codon 12 mutation (22%, OR = 1.77 and 21%, OR = 1.52), respectively. A similar positive association was seen in human papilloma virus (HPV)-infected patients (OR = 5.66, P < 0.003). Our overall findings demonstrate that the mutational activation of the K-ras gene, HPV infection and tobacco or alcohol abuse, can be considered independently or in combination as high risk factors for ESCC development.     

Expressions of hypoxia-inducible factor-1α and hexokinase-II in gastric adenocarcinoma: the impact on prognosis and correlation to clinicopathologic features

The impact of hypoxia-inducible factor (HIF)-1α and hexokinase-II (HK-II) expression on prognosis of gastric adenocarcinoma patients has not been clearly established. We identified all patients in Cancer Center of Sun Yat-Sen University who were diagnosed as gastric adenocarcinoma and underwent radical gastrectomy between January 1999 and December 2001. We used immunohistochemistry to determine the expressions of HIF-1α protein and HK-II in the surgical sections. We identified 188 patients with gastric adenocarcinoma for the final analysis. The positive rate of HIF-1α and HK-II were 110/188 (54.6%) and 40/188 (21.3%), respectively. Both HIF-1α and HK-II were all positively correlated with tumor size, lower differentiation, and tumor stage. Univariate analysis showed that advanced tumor stages (P < 0.001), tumor size (P = 0.003), HIF-1α expression (P < 0.001), and HK-II expression (P < 0.001) were all significantly associated with shorter survival. The multivariate Cox analysis revealed that tumor stage (P < 0.001), HIF-1α expression (P < 0.001), and HK-II expression (P = 0.002) remained independent prognostic variables for survival. In addition, there was a positive correlation of HIF-1α protein expression and HK-II (P = 0.022). Both HIF-1α and HK-II were overexpressed in gastric adenocarcinoma. The multivariate Cox analysis revealed that both of them were independent factors on survival of gastric adenocarcinoma patients.     

Expression and Prognostic Value of PRL-3 in Human Intrahepatic Cholangiocarcinoma

Phosphatase of regenerating liver (PRL)-3 is involved in the metastasis of various tumors, but the expression of PRL-3 and its possible role in primary intrahepatic cholangiocarcinoma (ICC) has not been reported yet. In this study, we assessed the expression levels of PRL-3 by immunohistochemistry in 102 primary ICC samples, 62 matched lymph node metastases (LNM) and 102 adjacent normal liver tissues. Then we investigated the relationship between PRL-3 expression and clinicopathologic factors. Survival analysis was performed to determine the prognostic significance of PRL-3 expression in ICC. Immunochemistry results suggested PRL-3 expression was negative or weak in non-neoplastic intrahepatic bile ducts of adjacent liver tissue. In primary lesion and LNM high PRL-3 expression was frequently detected. Furthermore, the rate of high PRL-3 expression in LNM was higher than that in primary lesion (80.6% vs. 47.1%, P < 0.05). High expression of PRL-3 in primary tumors was significantly associated with TNM (P < 0.001), T stage (P < 0.001), vascular invasion (P = 0.002), and LNM (P < 0.001). Survival analysis results with Kaplan-Meier method and Cox proportional hazard model indicated high expression of PRL-3 was correlated with decreased overall survival and was an independent prognostic marker of overall survival. Thus, our results suggested high expression of PRL-3 was correlated with progression and metastasis of ICC and indicated negative prognostic impact. PRL-3 might serve as a novel prognostic marker for patients with ICC.     

The Behavior of Matrix Metalloproteinase-9 in Lymphocytic Colitis,Collagenous Colitis and Ulcerative Colitis

Matrix metalloproteinases play an important role in extracellular matrix remodelling. It has been proposed that matrix metalloproteinase-9 (MMP-9) is involved in epithelial damage in ulcerative colitis (UC). However, to our knowledge, no data are available in terms of MMP-9 expression in microscopic colitis. Determination of mucosal protein expression levels of MMP-9 in lymphocytic colitis (LC), collagenous colitis (CC) and UC. MMP-9 immunohistochemical expressions were analyzed in paraffin-embedded tissue samples by immunohistochemistry including patients with LC, CC, UC, active diverticulitis, inactive diverticular disease and healthy control subjects. UC was also subgrouped according to the severity of inflammation. Immunostaining was determined semiquantitatively. Independent colonic biopsies from healthy and severe UC cases were used for gene expression analyses. For further comparison MMP-9 serum antigen levels were also determined in patients with UC and control patients without macroscopic or microscopic changes during colonoscopy. MMP-9 mucosal expression was significantly higher in UC (26.7 ± 19.5%) compared to LC (6.6 ± 9.3%), CC (6.4 ± 7.6%), active diverticulitis (5.33 ± 2.4%), inactive diverticular disease (5.0 ± 2.2%) and controls (6.3 ± 2.6%) (P < 0.001). The immunohistochemical expression of MMP-9 in LC and CC was similar as compared to controls. MMP-9 expression was significantly higher in each inflammatory group of UC compared to controls (mild: 11.0 ± 2.8%, moderate: 23.9 ± 3.7%, severe UC: 52.6 ± 3.9% and 6.3 ± 2.6%, respectively, P < 0.005). The gene expression microarray data and RT-PCR results demonstrated a significantly higher expression of MMP-9 in severely active UC compared to healthy controls (P < 0.001). Significantly higher MMP-9 serum antigen concentrations were observed in UC patients compared with the control group (P < 0.05). MMP-9 seems to play no role in the inflammatory process of LC and CC. In contrast, the mucosal up-regulation of MMP-9 correlated with the severity of inflammation in UC. The increased MMP-9 expression could contribute to the severity of mucosal damage in active UC.