Enhanced expression of human β-defensin 2 in peripheral lungs of patients with chronic obstructive pulmonary disease

Human β-defensin 2 (hBD-2) has antimicrobial activity and may play a role in airway mucosal defense, but studies have not yet examined its expression in lung tissue of patients with chronic obstructive pulmonary disease (COPD). Here we investigated hBD-2 levels in lung tissues of COPD patients and analyzed their correlations with IL-8, IL-1β, cigarette smoking and lung function in order to see whether the protein may be involved in pathogenesis of the disease. Peripheral lung tissue specimens were obtained from 51 patients who underwent lung resection for peripheral lung cancer: healthy non-smokers (n = 8), healthy current smokers (n = 7), non-smokers with COPD (n = 11), and current smokers with COPD (n = 25). RT-PCR and immunohistochemical staining were used to detect expression levels of hBD-2, IL-8 and IL-1β. Expression of hBD-2 mRNA was significantly higher in COPD patients than in healthy controls, and significantly higher in current smokers than in non-smokers (p < 0.05). Among healthy controls, hBD-2 mRNA levels were similar between current smokers and non-smokers. Immunohistochemistry showed hBD-2 protein to be expressed mainly in epithelia of distal bronchioles and its expression pattern among our patient groups mirrored that of the mRNA. IL-8 mRNA levels were significantly higher in COPD patients than in healthy controls (p < 0.05), while IL-1β mRNA levels did not differ significantly among the groups. Levels of hBD-2 mRNA positively correlated with levels of IL-8 mRNA (r = 0.545, p = 0.002), and negatively correlated with FEV1/FVC ratios and with predicted FEV1% values (r = −0.406, p = 0.011). Our results indicate that hBD-2 expression is elevated in distal airways of COPD patients and that it may be involved in pathogenesis of the disease. Our data implicate cigarette smoking as a factor that may elevate hBD-2 levels in lung tissues of COPD patients.     

Inhibition of C6 rat glioma proliferation by [Ru2Cl(Ibp)4] depends on changes in p21, p27, Bax/Bcl2 ratio and mitochondrial membrane potential

The ruthenium compound [Ru₂Cl(Ibp)₄] (or RuIbp) has been reported to cause significantly greater inhibition of C6 glioma cell proliferation than the parent HIbp. The present study determined the effects of 0-72 h exposure to RuIbp upon C6 cell cycle distribution, mitochondrial membrane potential, reactive species generation and mRNA and protein expression of E2F1, cyclin D1, c-myc, pRb, p21, p27, p53, Ku70, Ku80, Bax, Bcl2, cyclooxygenase 1 and 2 (COX1 and COX2). The most significant changes in mRNA and protein expression were seen for the cyclin-dependent kinase inhibitors p21 and p27 which were both increased (p < 0.05). The marked decrease in mitochondrial membrane potential (p < 0.01) and modest increase in apoptosis was accompanied by a decrease in anti-apoptotic Bcl2 expression and an increase in pro-apoptotic Bax expression (p < 0.05). Interestingly, COX1 expression was increased in response to a significant loss of prostaglandin E₂ production (p < 0.001), most likely due to the intracellular action of Ibp. Future studies will investigate the efficacy of this novel ruthenium-ibuprofen complex in human glioma cell lines in vitro and both rat and human glioma cells growing under orthotopic conditions in vivo.     

Eurycomanone suppresses expression of lung cancer cell tumor markers, prohibitin, annexin 1 and endoplasmic reticulum protein 28

Bioactive compounds from the medicinal plant, Eurycoma longifolia Jack have been shown to promote anti-proliferative effects on various cancer cell lines. Here we examined the effects of purified eurycomanone, a quassinoid found in Eurycoma longifolia Jack extract, on the expression of selected genes of the A549 lung cancer cells. Eurycomanone inhibited A549 lung cancer cell proliferation in a dose-dependent manner at concentrations ranging from 5 to 20 μg/ml. The concentration that inhibited 50% of cell growth (GI₅₀) was 5.1 μg/ml. The anti-proliferative effects were not fully reversible following the removal of eurycomanone, in which 30% of cell inhibition still remained (p < 0.0001, T-test). At 8 μg/ml (GI₇₀), eurycomanone suppressed anchorage-independent growth of A549 cells by >25% (p < 0.05, T-test, n = 8) as determined using soft agar colony formation assay. Cisplatin, a chemotherapy drug used for the treatment of non small cell lung cancer on the other hand, inhibited A549 cells proliferation at concentrations ranging from 0.2 μg/ml to 15 μg/ml with a GI₅₀ of 0.58 μg/ml. The treatment with eurycomanone reduced the abundance expression of the lung cancer markers, heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1, p53 tumor suppressor protein and other cancer-associated genes including prohibitin (PHB), annexin 1 (ANX1) and endoplasmic reticulum protein 28 (ERp28) but not the house keeping genes. The mRNA expressions of all genes with the exception of PHB were significantly downregulated, 72 h after treatment (p < 0.05, T-test, n = 9). These findings suggest that eurycomanone at viable therapeutic concentrations of 5-20 μg/ml exhibited significant anti-proliferative and anti-clonogenic cell growth effects on A549 lung cancer cells. The treatment also resulted in suppression of the lung cancer cell tumor markers and several known cancer cell growth-associated genes.     

Overexpression of the Interferon regulatory factor 4-binding protein in human colorectal cancer and its clinical significance

Background: IFN regulatory factor 4-binding protein (IBP) is a novel type of activator of Rho GTPases. It has been linked with differentiation and apoptosis of lymphocytes, but its function in oncogenesis remains unclear. Here we studied the expression of endogenous IBP in four human colorectal cancer cell lines, normal, adenoma and tumor colorectal tissues. Methods: Molecular (Western blot and RT-PCR), and confocal analyses were used to investigate IBP expression in human colorectal cancer cell lines. Matched normal and tumor tissue sections of 63 patients and 15 adenoma tissue sections were analyzed for IBP expression by immunohistochemistry (IHC). Results: IBP was ubiquitely expressed in human colorectal cancer cell lines. The expression of IBP can be detected at both the mRNA and protein level in SW480, SW620 and HT29 cells. Clinically, IBP were elevated in human colorectal cancer specimens in comparison to normal colorectal tissues. Substantial high expression of IBP was observed in colorectal cancer tissues (67%), whereas corresponding normal tissues and 15 adenoma tissues showed consistently absent immunoreactivity of IBP. Moreover, IBP expression is correlated with the differentiation level of colorectal cancer cells (p < 0.05) and clinical stage of patients (p < 0.01). Conclusions: Our data show, for the first time, a dysregulated expression of IBP in human colorectal cancer, offering new perspectives for its role in cancer development and progression. IBP may be a novel tumor marker and a therapeutic target for colorectal cancer.     

The clinicopathological significance of REIC expression in colorectal carcinomas

REIC is down-regulated in immortalized cell lines compared with the parental normal counterparts, and could inhibit colony formation, tumor growth and induce apoptosis. Here, its expression was examined by immunohistochemistry on tissue microarray containing colorectal non-neoplastic mucosa (NNM), adenoma and adenocarcinoma. Colorectal carcinoma tissue and cell lines were studied for REIC expression or its secretory level by Western blot, RT-PCR or enzyme-linked immunosorbent assay (ELISA). The results demonstrated that REIC was differentially expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620, and WiDr with its secretion concentration less than 300 pg/mL. Carcinomas showed statistically lower REIC expression than matched NNM with no difference for protein content. Immunohistochemically, REIC expression was significantly decreased from NNM, adenoma to adenocarcinoma (p<0.05). REIC expression was negatively correlated with depth of invasion, TNM staging, dedifferentiation, Capase-3 and nuclear inhibitor of growth 5 (ING5) expression (p<0.05), while not with age, sex, tumor size, lymphatic or venous invasion, or lymph node metastasis (p>0.05). Kaplan-Meier analysis indicated that REIC expression was not associated with the prognosis of colorectal carcinomas (p>0.05). Cox's analysis demonstrated that lymphatic and venous invasion, lymph node metastasis, and UICC staging were independent prognostic factors for carcinoma (p<0.05). Our study indicated that down-regulated REIC expression might play an important role in colorectal adenoma-adenocarcinoma sequence and subsequent progression. Aberrant REIC expression might be employed as a good marker of pathogenesis and development of colorectal carcinomas.     

Ursolic acid inhibits tumor angiogenesis and induces apoptosis through mitochondrial-dependent pathway in Ehrlich ascites carcinoma tumor

Ursolic acid (UA) is a pentacyclic triterpene naturally occurring in many plant foods. In the present study, we investigated anti-cancer activity of UA in vivo in Ehrlich ascites carcinoma (EAC) tumor. 15 × 10⁶ EAC cells were implanted intraperitoneally (i.p., ascitic tumor) and subcutaneous (s.c., solid tumor) in Swiss albino mice. Mice with established tumors received UA i.p. at 25, 50 and 100 mg/kg bw for 14 d in ascitic and 100 mg/kg bw in solid tumor for 30 d. On day 15, blood samples were collected for hematological assessment of hemoglobin (Hb%), RBCs, WBCs and PCV. Tumor volume, cell viability, angiogenic, anti-angiogenic, anti-inflammatory factors and antioxidant parameters were determined. Immunohistochemistry analysis for VEGF, iNOS, CD31, caspase-3 and Bax were also performed. UA significantly inhibited tumor growth, cell viability, in both ascites and solid tumor model in vivo (p < 0·001). The anti-angiogenic effects were accompanied with decreased VEGF, iNOS, TNF-α and increased IL-12 levels. UA at 100 mg/kg bw dose significantly increased SOD and CAT activity (p < 0.01). GSH and TBARS were increased as compared to control group (p < 0.001). Furthermore, UA increased total RBCs, WBCs as well as Hb% significantly (p < 0.05) compared to cyclophosphamide (CP). Histopathological examination of tumor cells in the treated group demonstrated signs of apoptosis with chromatin condensation and cell shrinkage. Decreased peritoneal angiogenesis showed the anti-angiogenic potential. UA downregulated VEGF & iNOS expression whereas bax and caspase-3 expressions were upregulated suggesting drug induced tumor cell apoptosis through activating the pro-apoptotic bcl-2 family and caspase-3 and downregulation of VEGF. The present study sheds light on the potent antitumor property of the UA and can be extended further to develop therapeutic protocols for treatment of cancer.     

Decreased circulating miR-375: A potential biomarker for patients with non-small-cell lung cancer

MicroRNAs (miRNAs) are directly involved in cancer initiation, progression and metastasis. Alterations of miRNAs expression in cancer tissue may be reflected in circulation. We attempted to investigate the expression and clinical significance of plasma miR-20a, miR-31 and miR-375 in patients with non-small cell lung cancer (NSCLC). The plasma levels of miR-20a, miR-31 and miR-375 in 164 NSCLC patients and 164 healthy controls (discovery cohort) were evaluated and compared among various clinicopathological characteristics. The relationship between miRNA expression and clinical outcome of NSCLC patients was examined in an independent cohort (53 cases and 53 controls). The expression level of miR-375 in tissue was also examined. Plasma miR-375 levels in NSCLC patients were significantly decreased in both patient cohorts (P < 0.05). In addition, patients with metastatic NSCLC had lower plasma miR-375 expression than those with non-metastatic NSCLC (P < 0.05). Survival analysis showed that patients with low miR-375 expression had worse overall survival rates than those with high miR-375 expression (hazard ratios (HR) = 1.537 (1.046–2.258), P = 0.029). This association was independently validated in a separate cohort of 53 NSCLC patients (HR = 2.406, 95% CI 1.170–4.945, P = 0.017). The expression level of miR-375 was also found to be significantly down-regulated in NSCLC tissues compared with paracancerous tissues (P < 0.001). These findings indicate that miR-375 has an important role in NSCLC initiation and progression, and may be an independent poor prognostic factor in NSCLC patients.     

Prediction value of intercellular adhesion molecule-1 gene polymorphisms for epithelial ovarian cancer risk,clinical features,and prognosis

Intercellular adhesion molecule-1 (ICAM-1, encoded by ICAM-1) is implicated in tumorigenesis and tumor progression. ICAM-1 modulates the susceptibility to several types of cancer and the disease prognosis; however, its role in epithelial ovarian cancer (EOC) is unclear. Here, we evaluate single nucleotide polymorphisms (SNPs) in ICAM-1 as predictors of EOC risk and prognosis. Six ICAM-1 polymorphisms were genotyped in 408 patients with EOC and 520 controls using the MassARRAY system. The ICAM-1 mRNA levels in 89 EOC tissues and 35 normal ovarian tissues were examined using quantitative PCR. The ICAM-1 rs5498 G allele was associated with increased tumor grade (OR = 2.650) and EOC risk (OR = 1.405). This risk was more evident in females who had first-degree relatives (FDRs) with a tumor (OR = 3.475) or who experienced early menarche (OR = 2.774). The ICAM-1 expression in the cancerous tissue was elevated compared with that of normal ovarian tissues (p < 0.0001), and it was associated with an rs5498 genotype (p = 0.0002). ICAM-1 SNPs did not significantly predict the overall EOC survival (p > 0.05). However, the rs5498 G allele correlated with EOC survival time in patients whose FDRs suffered from a tumor (p = 0.001). ICAM-1 rs5498 likely confers a high risk for EOC in G allele carriers accompanied by up-regulation of ICAM-1 expression during carcinogenesis. The combination of ICAM-1 rs5498 and tumor history predicts the EOC prognosis.     

Genetic deletion of mPGES-1 accelerates intestinal tumorigenesis in APC(Min/+) mice

The induced synthesis of bioactive prostanoids downstream of cyclooxygenase-2 (COX-2) and prostaglandin H₂ (PGH₂) exerts a critical event in colorectal carcinogenesis. Here we demonstrate that APC^Min/+ mice with genetic deletion of microsomal prostaglandin E synthase-1 (mPGES-1), which catalyses the terminal conversion of PGH₂ into PGE₂, surprisingly develop more and generally larger intestinal tumors than do mPGES-1 wild type littermates (mean number of tumors/intestine 80 vs. 38, p < 0.0005, mean tumor diameter 1.64 vs. 1.12 mm, p < 0.0005). No deviation regarding the expression of other PGE₂ related enzymes (COX-1, COX-2, mPGES-2, cPGES, and 15-PGDH) or receptors (EP1-4) was obvious among the mPGES-1 deficient mice. PGE₂ levels were suppressed in tumors of mPGES-1 deficient animals, but the concentrations of other PGH₂ derived prostanoids were generally enhanced, being most prominent for TxA₂ and PGD₂. Thus, we hypothesise that a redirected synthesis towards other lipid mediators might (over)compensate for loss of mPGES-1/PGE₂ during intestinal tumorigenesis. Nevertheless, our results question the suitability for mPGES-1 targeting therapy in the treatment or prevention of colorectal cancer.     

Adrenomedullin production is increased in colorectal adenocarcinomas; its relation to matrix metalloproteinase-9

Adrenomedullin (AM) is highly expressed in various cancer cell lines, suggesting a possible association with cancer growth. In the present study, we examined the expression and/or concentration of AM, its related peptide, adrenomedullin2/intermedin (AM2/IMD) and their receptors in human colorectal cancer and the surrounding normal tissue. In addition, we assessed the correlation between the expression of AM and AM2/IMD with that of vascular endothelial growth factor (VEGF)-A and matrix metalloproteinase (MMP)-9. Using a specific immunoradiometric assay, we found that AM concentrations were 2-11-fold higher in colorectal cancer tissues than in the surrounding normal tissues. Moreover, real-time quantitative RT-PCR showed that the expression levels of preproAM (+548%), preproAM2/IMD (+2674%), calcitonin receptor-like receptor (CLR) (+518%), receptor activity modifying protein (RAMP)2 (+281%), RAMP3 (+178%), VEGF-A (+277%) and MMP-9 (+864%) mRNAs were significantly higher in cancer tissues than in the surrounding normal tissues, and there was a positive correlation between the gene expressions of MMP-9 and preproAM (r = 0.352; p = 0.005), but not with preproAM2/IMD (r = 0.041, p = 0.406). Both AM and AM2/IMD immunoreactivity were detected mainly within cancer cells, whereas MMP-9 immunoreactivity was mostly seen in the surrounding stroma. These findings suggest that AM produced in colorectal tumors acts in concert with MMP-9 in the stroma to contribute to the pathogenesis of colorectal cancer.     

Expression of Duffy antigen receptor for chemokines (DARC) is down-regulated in colorectal cancer

Abstract

Duffy antigen receptor for chemokines (DARC) is a silent chemokine receptor which selectively binds angiogenic chemokines without inducing conventional signaling responses. DARC has been reported to inhibit the development of multiple cancers through clearance of angiogenic chemokines. However, its role in colorectal cancer (CRC) remains unclear. We investigated the expression of DARC in CRC and explored correlation of DARC expression with clinical pathological features and microvessel density (MVD). The protein expression levels of DARC were detected by immunohistochemistry in 90 CRC and 64 paired unaffected tissues. The mRNA levels of DARC were detected by quantitative real-time PCR in 15 CRC and paired unaffected tissues. MVD in CRC was also assessed by immunohistochemistry of CD34. We found that the mRNA and protein expression levels of DARC were significantly lower in CRC than in the unaffected tissues (p?<?0.05). The DARC protein expression levels were positively correlated with DARC mRNA expression levels in both CRC (p?<?0.001) and unaffected tissues (p?<?0.001). We also found that DARC expression was significantly correlated with tumor differentiation (p?<?0.001), lymph node metastasis (p?<?0.01) and TNM stage (p?<?0.05). Moreover, we observed a strong negative relationship between DARC expression and MVD in CRC (p?<?0.001). We showed that DARC expression is down-regulated in CRC and associated with clinical pathological features and MVD of CRC. DARC might be involved in tumorigenesis, progression, angiogenesis, and metastasis of CRC.     

ZIC1 is downregulated through promoter hypermethylation in gastric cancer

As one of major epigenetic changes responsible for tumor suppressor gene inactivation in the development of cancer, promoter hypermethylation was proposed as a marker to define novel tumor suppressor genes. In the current study we identified ZIC1 (Zic family member 1, odd-paired Drosophila homolog) as a novel tumor suppressor gene silenced through promoter hypermethylation in gastric cancer, the second leading cause of cancer death worldwide. In all of gastric cancer cells lines examined, ZIC1 expression was downregulated and such downregulation was accompanied with the hypermethylation of ZIC1 promoter. Demethylation treatment with 5-aza-2′-deoxycytidine (Aza) reversed ZIC1 downregulation, highlighting the importance of promoter methylation to ZIC1 downregulation in gastric cancer cells. Notably, ZIC1 expression was significantly downregulated in primary gastric carcinoma tissues in comparison with non-tumor adjacent gastric tissues (p < 0.01). Accordingly, promoter methylation of ZIC1 was frequently detected in primary gastric carcinoma tissues (94.6%, 35/37) but not normal gastric tissues, indicating that promoter hypermethylation mediated ZIC1 downregulation may play an important role in gastric carcinogenesis. Indeed, ectopic expression of ZIC1 led to the growth inhibition of gastric cancer cells through the induction of S-phase cell cycle arrest (p < 0.01). Our results revealed ZIC1 as a novel candidate tumor suppressor gene downregulated through promoter hypermethylation in gastric cancer.