Mechanisms of growth arrest by zinc ribbon domain-containing 1 in gastric cancer cells

MicroRNA-4316 inhibits gastric cancer proliferation and migration via directly targeting VEGF-A

Background and aims

microRNAs (miRNAs) have been reported to regulate proliferation and migration by down-regulating the expression of target genes. The aims of this study were to investigate whether miR-4316 inhibited proliferation and migration by downregulating vascular endothelial growth factor A (VEGF-A) and its clinical significance in gastric cancer (GC).

Methods

The clinical tissues of the GC patients for miR-4316 and VEGF-A were detected by qRT-PCR. The protein levels of VEGF-A and c-Met were determined by western blotting. Cell Proliferation, migration, and colony forming assays were conducted to show whether miR-4316 affects proliferation by CCK-8, migration by transwell, wound healing and colony formation assays. The bioinformatic methods and luciferase reporter assay were applied to detect the relationship between miRNA and VEGF-A on its targeting 3-untranslated regions (3-UTRs). CCK-8, colony formation, wound healing, and transwell assay were performed to explore the function of miR-4316.

Results

The results of qRT-PCR indicated that miR-4316 expression level was significantly downregulated in human GC tissues and GC cell lines compared with their control. miR-4316 inhibited proliferation, migration and colony formation in GC cell lines by reducing VEGF-A. And western blot results indicated that miR-4316 significantly inhibited GC through repressing VEGF-A and c-Met. The investigation of Luciferase assay indicated that VEGF-A is a direct target gene of miR-4316.

Conclusions

miR-4316 suppressed proliferation and migration of GC through the VEGF-A gene. MiR-4316 acts as a tumor suppressor by targeting VEGF-A and this indicated that MiR-4316 might be a potential therapeutic target for GC.

Genome-wide association study identified new susceptible genetic variants in HLA class I region for hepatitis B virus-related hepatocellular carcinoma

We have performed a genome-wide association study (GWAS) including 473 Japanese HBV (hepatitis B virus)-positive HCC (hepatocellular carcinoma) patients and 516 HBV carriers including chronic hepatitis and asymptomatic carrier individuals to identify new host genetic factors associated with HBV-derived HCC in Japanese and other East Asian populations. We identified 65 SNPs with P values < 10-4 located within the HLA class I region and three SNPs were genotyped in three independent population-based replication sets. Meta-analysis confirmed the association of the three SNPs (rs2523961: OR = 1.73, P = 7.50 × 10-12; rs1110446: OR = 1.79, P = 1.66 × 10-13; and rs3094137: OR = 1.73, P = 7.09 × 10-9). We then performed two-field HLA genotype imputation for six HLA loci using genotyping data to investigate the association between HLA alleles and HCC. HLA allele association testing revealed that HLA-A * 33:03 (OR = 1.97, P = 4.58 × 10-4) was significantly associated with disease progression to HCC. Conditioning analysis of each of the three SNPs on the HLA class I region abolished the association of HLA-A*33:03 with disease progression to HCC. However, conditioning the HLA allele could not eliminate the association of the three SNPs, suggesting that additional genetic factors may exist in the HLA class I region.

Single nucleotide polymorphisms in ZNRD1-AS1 increase cancer risk in an Asian population

Single nucleotide polymorphisms (SNPs) in human zinc ribbon domain containing 1 antisense RNA 1 (ZNRD1-AS1) have been associated with cancer development. In this meta-analysis, we more precisely estimated the associations between three expression quantitative trait loci SNPs in ZNRD1-AS1 (rs3757328, rs6940552, and rs9261204) and cancer susceptibility. The data for three SNPs were extracted from eligible studies, which included 5,293 patients and 5,440 controls. Overall, no significant associations between SNPs in ZNRD1-AS1 (rs3757328, rs6940552, and rs9261204) and cancer risk were observed. However, in further subgroup analyses based on cancer type, we found that the A allele of rs3757328 increased the risk of some cancer in both allele contrast (OR = 1.15, 95% CI = 1.05 – 1.25) and recessive models (OR = 1.79; 95% CI = 1.33 – 2.41). The A allele of rs6940552 and the G allele of rs9261204 also increased the risk of some cancer in an Asian population in allele contrast (OR = 1.17, 95% CI = 1.08 – 1.26, and OR = 1.25, 95% CI = 1.16 – 1.34, respectively) and recessive models (OR = 1.44, 95% CI = 1.18 – 1.77, and OR = 1.49; 95% CI = 1.23 – 1.80, respectively). Thus, rs3757328, rs6940552, and rs9261204 in ZNRD1-AS1 are all associated with increased some cancer risk in an Asian population.

Hepatitis B virus genotypes, expression quantitative trait loci for ZNRD1-AS1 and their interactions in hepatocellular carcinoma

Genetic variants in zinc ribbon domain-containing 1 antisense RNA 1 (ZNRD1-AS1) have been reported to be associated with development of hepatocellular carcinoma (HCC). We sought to determine the influences of ZNRD1-AS1 polymorphisms and their interactions with Hepatitis B virus (HBV) genotypes on the risk of HCC. In this study, we conducted a large population case-control study with 1,507 HBV-related HCC cases and 1,560 HBV persistent carriers. Three single-nucleotide polymorphisms (SNPs) in ZNRD1-AS1 (rs3757328, rs6940552 and rs9261204) were genotyped using a TaqMan allelic discrimination assay, and the HBV genotypes were identified by multiplex PCR. We found consistently significant associations between the ZNRD1-AS1 rs6940552 and rs9261204 SNPs with an increased risk of HCC (additive genetic model: adjusted OR = 1.16, 95% CI = 1.03-1.32 for rs6940552; adjusted OR =1.20, 95% CI = 1.06-1.35 for rs9261204) and found a borderline association between rs3757328 and HCC risk. Besides, we observed a dose-dependent relationship between increasing numbers of variant alleles of the SNPs and HCC risk (P for trend <0.001). Moreover, we observed a stronger combined effect of the three SNPs on HCC risk among the subjects infected with non-B genotype HBV (adjusted OR = 1.26, 95% CI = 1.05-1.50) compared with HBV B-related genotypes (adjusted OR = 0.89, 95% CI = 0.69-1.15; P= 0.029 for heterogeneity test). We also found that a multiplicative interaction between the variant alleles and the HBV genotype significantly affected HCC susceptibility (P = 0.030). Together, these results indicate that ZNRD1-AS1 may influence HCC risk accompanied by HBV genotypes.

Immune regulation and anti-inflammatory effects of isogarcinol extracted from Garcinia mangostana L. against collagen-induced arthritis

Isogarcinol is a natural compound that we extracted from Garcinia mangostana L., and we were the first to report that it is a new immunosuppressant. In the present study, we investigated the immune regulation and anti-inflammatory effects of isogarcinol on collagen-induced arthritis (CIA) and explored its potential mechanism in the treatment of rheumatoid arthritis. The oral administration of isogarcinol significantly reduced clinical scores, alleviated cartilage and bone erosion, and reduced the levels of serum inflammatory cytokines in CIA mice. Isogarcinol inhibited xylene-induced mouse ear edema in vivo. In vitro, isogarcinol decreased iNOS and COX-2 mRNA expression and NO content by inhibiting NF-κB expression. Furthermore, isogarcinol decreased the activity of NFAT and inhibited IL-2 expression. The mechanism of action of isogarcinol is associated with down-regulation of both autoimmune and inflammatory reactions.

Variants in ZNRD1 gene predict HIV-1/AIDS disease progression in a Han Chinese population in Taiwan

Patients demonstrate notable variations in disease progression following human immunodeficiency virus (HIV) infection. We aimed to identify ZNRD1 and RNF39 genetic variants linked to AIDS progression. We conducted a genetic association study in HIV-1-infected Han Chinese patients residing in Taiwan. The clinical characteristics of 143 HIV-1-infected patients were measured, and patients were split into 2 groups: AIDS progression and AIDS non-progression. Genotyping of ZNRD1 and RNF39 was performed in all participants. We found that patients in the AIDS progression group had higher HIV-1 viral loads and lower CD4 cell counts than did patients in the AIDS non-progression group. The frequency of the AA genotype of ZNRD1 (rs16896970) was lower in the AIDS progression group than in the AIDS non-progression group. Patients with AA genotypes had lower levels of HIV-1 viral loads and higher levels of CD4 cell counts than did patients with AG+GG genotypes. AIDS progression in patients with the AA group is significantly different from that in patients with the AG and GG groups by using Kaplan-Meier survival analysis. The hazard ratio for progression was lower in the AA group than in the AG and GG groups. We identified a SNP that contributes to AIDS progression in HIV-1-infected patients in this population. This SNP had a significant protective influence on AIDS progression, and polymorphisms of the ZNRD1 gene may play a role in the pathogenesis of HIV-1 infection.

A novel monoclonal antibody specific to mouse IL-17

IL-17 is secreted by T helper (Th) 17 cells, and might play important roles in host defense against extracellular bacterial infection and fungal infection and contribute to the pathogenesis of various autoimmune inflammatory diseases. Here we have, for the first time, generated the monoclonal antibody against the rat IL-17 protein, which is secreted by T helper (Th) 17 cells. Enzyme-linked immunosorbent assay (ELISA) and Western immunoblotting were used to screen the hybridomas. As a result, one MAb named Y11 (IgG1) was characterized, which was effective in detecting the recombinant and the cellular protein. Then the MAb was used to detect the expression of IL-17 in rat intestine graft tissues by immunohistochemical analysis. Thus, Y11 could be considered a useful tool for studies of IL-17 expression and function.

ROS-activated p38 MAPK/ERK-Akt cascade plays a central role in palmitic acid-stimulated hepatocyte proliferation

In the past years, free fatty acids (FFAs) and obesity have been reported to play an important role in cancer development. Palmitic acid (PA) is the most prevalent saturated FFA in circulation. However, the mechanism underlying the effect of PA on cell proliferation is still to be elucidated. In this report, we, for the first time, investigate the signaling pathway in human normal hepatocytes (QZG) responsible for PA-induced proliferation. The results demonstrate that PA promotes cell cycle progression, accelerates cell proliferation, and induces a transient and sequential activation of a series of kinases. The employment of several inhibitors and antioxidants indicates that a ROS-induced stress-sensitive p38 MAPK/ERK-Akt cascade plays a critical role in the regulation of PA on cell cycle and cell proliferation. Moreover, PA dose and time dependently activates Nrf2 and this activation relies on ROS-induced stimulation of p38 MAPK/ERK-Akt signaling, demonstrating that Nrf2 activation may be associated with the regulation of PA on cell cycle transition and proliferation. In conclusion, our study elucidates the importance of PA metabolism on cell proliferation, and suggests that PA stimulates hepatocyte proliferation through activating the ROS-p38 MAPK/ERK-Akt cascade which is intersected with the activation of Nrf2 and that the effect of ROS on signal transduction is in a dose- and time-dependent manner. All the above noted provide a new clue for the central role of ROS in cell proliferation and tumorigenesis.

Role of ZNRD1 (zinc ribbon domain-containing 1) in angiogenesis of leukaemia cells

Here, we have first investigated the roles of ZNRD1 in angiogenesis of leukaemia. The leukaemia cell line K562 was transfected with the vector that included the full-length cDNA of ZNRD1, then the growth and angiogenesis of cells were detected. Up-regulation of ZNRD1 could significantly inhibit the growth of cells, reduce tumour microvessel densities and inhibit the VEGF (vascular endothelial growth factor) production. The results of human miRNA array and real-time PCR showed that ZNRD1 could significantly up-regulate the expression of miR-214 and down-regulate the expression of miR-296. Taken together, ZNRD1 might inhibit tumour angiogenesis and could be considered as a target for leukaemia therapy.

The function and mechanism of COX-2 in angiogenesis of gastric cancer cells

BACKGROUND

Here we aimed to investigate the effect of COX-2 siRNA on proliferation and angiogenesis of gastric cancer cells.

METHODS

The gastric cancer cell line SGC7901 was transfected with COX-2 siRNA, then the growth and angiogenesis of cells were detected by in vitro and in vivo assay. Human microarray, RT-PCR and western blot were used to identify differentially expressed angiogenesis-related molecules in cells with decreased expression of COX-2.

RESULTS

Down-regulation of COX-2 could significantly inhibit the in vitro and in vivo growth of gastric cancer cells, and suppress the migration and tube formation of human umbilical vein endothelial cells. Totally 23 angiogenesis-related molecules were found involved in COX-2-induced angiogenesis suppression. The results of RT-PCR and western blot showed that down-regulation of COX-2 might inhibit VEGF, Flt-1, Flk-1/KDR, angiopoietin-1, tie-2, MMP2 and OPN.

CONCLUSIONS

COX-2 might mediate tumor angiogenesis and growth, and could be considered as a target for gastric cancer therapy.

Monoclonal antibodies MC3 and MC5 can be used as a tool for screening colorectal cancer

MC3 and MC5 are both colorectal cancer-specific MAbs previously prepared in our laboratory that can detect colorectal cancer with high sensitivity and specificity. Thus far the distribution of MC3-Ag and MC5-Ag in colorectal cancer remains largely unknown. In the present study, we have firstly found that the expression of MC3-Ag and MC5-Ag was higher in moderate-differentiated and poor-differentiated colorectal cancer tissue than that in well-differentiated colorectal cancer tissue by immunohistochemistry. The expression of MC5-Ag in colorectal cancer tissue without metastasis was found to be significantly less than that in tissue accompanied with metastasis. However, the expression of MC3-Ag in colorectal cancer tissue without metastasis was found similar to that in tissue accompanied with metastasis. The results showed that MC3-Ag and MC5-Ag might play important roles in colorectal carcinogenesis and that MC3 and MC5 could be used as a tool for screening colorectal cancer.

Expression and prognostic value of ZNRD1 in esophageal squamous cell carcinoma

The expression of ZNRD1 in esophageal cancer was first investigated by immunohistochemical analysis, RT-PCR and real-time PCR. The ZNRD1 antibody produced a consistently cytoplasmic staining pattern in all epithelial cells. The expression of ZNRD1 was statistically correlated with differentiation, depth of invasion, lymph node metastasis, pathological stage, lymphatic invasion, and vascular invasion. The survival rates of patients with ZNRD1-negative tumors tended to be statistically lower than those with ZNRD1-positive tumors. ZNRD1 expression was also confirmed to be down-regulated in esophageal cancer tissues compared to adjacent non-neoplastic tissues. The results showed that ZNRD1 might play an important role in esophageal carcinogenesis.

Advances in gastroma angiogenesis and antiangiogenesis treatment for gastric carcinoma

As a component of tumor stroma, tumor angiogenesis is not only essential to primary tumor growth but also one of the requisites to disseminate. Ultrastructural organization and immunohistochemisty have shown that density and quantity of blood vessels has a close association with the potentiality of tumor invasion and metastasis. Some recent studies confirm correlation between angiogenesis and invasion of gastric tumor, and some other studies prove that antiangiogenesis can significantly inhibit tumor growth and metastasis, which has demonstrated a promising application perspective for gastric carcinoma treatment.

DARPP-32 mediates multidrug resistance of gastric cancer through regulation of P-gp and ZNRD1

Here, we firstly investigated the roles of DARPP-32 in multidrug resistance of gastric cancer cells. Inhibition of DARPP-32 by small interfering RNA led to decreased sensitivity of cells to chemotherapeutic drugs, accompanied by increased capacity of cells to efflux adriamycin. Inhibition of DARPP-32 expression could significantly up-regulate the expression of permeability glycoprotein (P-gp) and zinc ribbon domain-containing 1 (ZNRD1), but not alter the expression of multidrug resistance-associated protein or glutathione transferase. The DARPP-32 siRNA-mediated MDR could be reversed by inhibitor of P-gp or siRNA of ZNRD1, indicating DARPP-32 might mediate MDR of gastric cancer through regulation of P-gp and ZNRD1.