Suppression of the cell proliferation in stomach cancer cells by the ZNRD1 gene

Long noncoding RNA polymorphisms in gynecological cancers

Gynecological malignancies are one of the main causes of cancer-induced mortality. Despite remarkable recent therapeutic advances, current therapeutic options are not sufficient. Regarding the effect of long noncoding RNAs (lncRNAs) on cell differentiation, proliferation and apoptosis, variations in their expression cause different anomalies, such as tumorigenesis. SNPs influence lncRNA function and expression. LncRNA polymorphisms can predict cancer risk and are effective for early diagnosis and customized therapy. In this literature review, we comprehensively investigate the effect of lncRNA polymorphisms on gynecological cancers. LncRNA-related variants are proposed to evaluate cancer incidence, early detection and management of personalized therapy. Nonetheless, more studies are required to validate the consistency of current findings in numerous samples and across various ethnic groups.

Interleukin-6 in Siberian sturgeon (Acipenser baeri): Molecular characterization and immune functional activity

Interleukin-6 (IL-6) is a pleiotropic cytokine with crucial immunoregulatory functions in both innate and adaptive immune responses. However, the IL-6 sequence and function remain unknown in sturgeon, one chondrostean fish. In the present study, we identified an interleukin-6 homolog from Siberian sturgeon (Acipenser baeri), named AbIL-6. Its open reading frame (ORF) was 657 nucleotides in length, encoding a polypeptide of 218 amino acids, which contains a signal peptide and the IL-6 family domain. Phylogenetic analysis showed that sturgeon IL-6 had close relationship with both teleost and chondrichthyes IL-6s. Abil-6 mRNA was highly expressed in spleen, brain and liver tissues of healthy sturgeon, and significantly up-regulated in the spleen, head kidney and liver by A.hydrophila (A.h) challenge. Heat-killed A.h and LPS effectively stimulated Abil-6 transcripts in primary spleen cells in vitro. In order to understand the bioactivity and influence of AbIL-6 on immune responses, recombinant AbIL-6 (rAbIL-6) was synthesized by prokaryotes and demonstrated to promote the proliferation of spleen cells and head kidney cells in vitro. Additionally, intraperitoneal injection of rAbIL-6 induced significantly higher expression of four immuno-related genes including il-1β, cxcl10, mhcIIβ and igm. rAbIL-6 improved the survival rate and reduced the tissue bacterial load after A.h infection. Taken together, these results suggest that AbIL-6 plays an important role in inflammatory responses and immune defense against bacterial infection of sturgeon.

MiR-26b suppresses hepatocellular carcinoma development by negatively regulating ZNRD1 and Wnt/β-catenin signaling

Previous studies have indicated that Zinc ribbon domain-containing 1 (ZNRD1) is attributed to the carcinogenesis of human tumors. However, the role of ZNRD1 and its regulation in hepatocellular carcinoma (HCC) are still largely unclear. In this study, we examined the expression profiles of ZNRD1 in HCC tissues by immunohistochemistry (IHC) and publicly datasets analysis. In vitro and in vivo experiments were conducted to identify the function of ZNRD1 in HCC. In addition, miRNA potentially targeting ZNRD1 was predicted by bioinformatics analysis and further verified via in vitro experiments. Our results revealed that ZNRD1 was frequently upregulated in HCC tissues compared with that in nontumor tissues. High ZNRD1 expression in HCC tissues was positively associated with advanced tumor stage and poor prognosis. Function experiments showed that knockdown of ZNRD1 inhibited cell growth and invasion in vitro, and suppressed tumor development in vivo. Moreover, ZNRD1 promoted the activation of Wnt/β-catenin signaling pathway in HCC. Importantly, miR-26b directly inhibited the transcription activity of ZNRD1. Overexpression of ZNRD1 dramatically abolished the inhibitory effects of miR-26b on HCC cells. Taken together, our results uncover a novel mechanistic role for miR-26b/ZNRD1 axis in HCC, proposing ZNRD1 inhibition as a potent therapeutic strategy for hepatocellular carcinoma.

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.

Strong evidence for LncRNA ZNRD1-AS1, and its functional Cis- eQTL locus contributing more to the susceptibility of lung cancer

Long noncoding RNAs (IncRNAs), involved in cancer biology, contributing to essential cancer cell functions such as proliferation, invasion, and metastasis, have received increasing attention recently. Human Zinc ribbon domain containing 1 (ZNRD1) has been confirmed to be involved in carcinogenesis and development of multiple cancers. ZNRD1-AS1, a lncRNA in the upstream region of ZNRD1 which could down-regulate the expression of ZNRD1, has been identified as a possible component in carcinogenesis. The underlying relations of ZNRD1-AS1 with lung cancer development and metastasis remain obscure. In current study, we first evaluated the expression ZNRD1-AS1 and ZNRD1 among lung cancer tissues and corresponding normal tissues, which showed higher expression of ZNRD1-AS1 and lower expression of ZNRD1. To reveal the underlying mechanisms, we then investigated the associations between ZNRD1 eQTLs SNPs in ZNRD1-AS1 and risk of lung cancer in Han Chinese populations. G allele of SNP rs9261204 was significantly associated with an increased risk of lung cancer when compared with A allele (OR: 1.45; 95% CI: 1.19–1.75; P = 1.06 × 10⁻⁴). A weaker, but similar effect was also observed in bladder cancer. SNP rs3757328 was also associated with increased risk of lung cancer (OR: 1.34; 95% CI: 1.07–1.67; P = 0.011). Our findings first confirmed the contribution of LncRNA ZNRD1-AS1 to the development of lung cancer in Asian population.

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.

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.

The expression of NOB1 in spiral ganglion cells of guinea pig

OBJECTIVE

NOB1 was a transcription-associated protein, consisting of one zinc ribbon domain. This study aimed to investigate the NOB1 expression in spiral ganglion cells of normal guinea pigs and deaf ones.

METHODS

Twelve guinea pigs were randomized equally into experimental group and control group. In experimental group, guinea pigs received a single intramuscular injection of gentamicin, while the control group was treated with physiological saline. Auditory brainstem responses (ABR) test was performed before and 10 days after injection, respectively. Guinea pigs of both groups were sacrificed and temporal bones were removed. The expression of NOB1 in the spiral ganglion was evaluated by immunohistochemistry.

RESULTS

NOB1 staining was found expressed in spiral ganglion cells from the basal turn to the apical turn of the cochlea. The expression of NOB1 was found significantly stronger in spiral ganglion cells of deaf guinea pigs as compared with that in normal ones.

CONCLUSIONS

The NOB1 was presented in spiral ganglions cells of the guinea pig and might play a role in hearing transduction.

Reversal of multidrug resistance of adriamycin-resistant gastric adenocarcinoma cells through the up-regulation of DARPP-32

We have investigated the roles of dopamine and cAMP-regulated phosphoprotein (DARPP-32) in the multidrug resistance (MDR) of gastric cancer cells and the possible underlying mechanisms. The up-regulation of DARPP-32 was found to significantly enhance the sensitivity of cells of human adriamycin (ADR)-resistant gastric adenocarcinoma cell line SGC7901/ADR to vincristine, ADR, 5-fludrouracil and cisplatin. The results of an in vivo drug sensitivity assay confirmed that DARPP-32 may play a specific role in the MDR of gastric cancer. DARPP-32 significantly down-regulated the expression of P-glycoprotein and zinc ribbon domain-containing 1 (ZNRD1), but did not alter the expression of MDR-associated protein or glutathione-S-transferase. The up-regulation of ZNRD1 significantly inhibited the drug sensitivity of gastric cancer cells over-expressing DARPP-32, indicating that ZNRD1 may be important in the DARPP-32-mediated MDR of gastric cancer. DARPP-32 was also able to significantly decrease the anti-apoptotic activity of SGC7901/ADR cells. Further study of the biological functions of DARPP-32 may be helpful for understanding the mechanisms of MDR of gastric cancer cells and developing possible strategies to treat gastric cancer.

Preparation and characterization of a novel monoclonal antibody specific to human EMILIN-5 protein

We aimed to establish the first monoclonal antibody (MAb) against the human EMILIN-5 protein (elastin microfibril interface located protein-5) and to investigate its distribution in normal human esophageal tissues and esophageal carcinomas. The bacterially expressed 6 His-EMILIN-5 fusion protein was induced and purified. Hybridomas were screened by indirect enzyme-linked immunosorbent assay (ELISA) using either purified 6x His-EMILIN-5 fusion proteins or purified 6x His-ZNRD1 fusion protein as a control. The EMILIN-5 protein-specific MAb was further identified by Western immunoblot analysis. The expression of EMILIN-5 was investigated in 63 cases of esophageal cancer specimens and 60 cases of normal esophageal specimens using immunohistochemical analysis. The expression of 6x His-EMILIN-5 fusion proteins was successfully induced. One MAb, H7 (IgG1), effective in detecting the recombinant and the cellular protein, was characterized. H7 bound to native EMILIN-5 protein and should be useful in studies of EMILIN-5 protein function and expression. EMILIN-5 staining was found positive in 37 cases of esophageal cancer tissues (59%) and 7 cases of normal esophageal tissues (12%). The higher-grade frequency of expression of EMILIN-5 in normal esophageal tissues was significantly lower (p < 0.01) than that in tumor tissues. We concluded that EMILIN-5 might play important roles in carcinogenesis of esophageal cancer.

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.

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

Previous studies by our laboratory indicated that zinc ribbon domain-containing 1 (ZNRD1) suppressed the growth of gastric cancer cells with a G(1) cell cycle arrest. However, the precise molecular mechanism underlying the growth-inhibitory effect of ZNRD1 remained fragmentary. In the present study, we have demonstrated that ZNRD1 could significantly inhibit the in vitro and in vivo growth of gastric cell line MKN28. Human cDNA microarray, reverse transcription-polymerase chain reaction and western blot analyses were used to identify differentially expressed cell cycle-related genes in MKN28 cells over-expressing ZNRD1. ZNRD1-induced growth suppression was found at least partially to regulate various proteins and signaling pathways controlling G(1) to S progression, including inhibition of cyclin D1 and CDK4, up-regulation of p21(CIP1/WAF1) and p27(Kip1) and acceleration of pRb dephosphorylation. Furthermore, ZNRD1 significantly inhibited the transcriptional activity of cyclin D1. p27(Kip1) might play a pivotal role in ZNRD1-induced cell cycle arrest because the p27(Kip1) anti-sense could block the cytostatic effects of ZNRD1. Moreover, ZNRD1 suppressed Skp2 expression via an increase in the protein instability, and induced significant decrease in cyclin E-CDK2 kinase activity. In addition, ZNRD1 could reduce tumor microvessel densities through inhibition of VEGF. Taken together, these results suggested that ZNRD1 might inhibit cell growth by targeting cell cycle-related genes and reducing tumor angiogenesis.

Enhanced cell survival of gastric cancer cells by a novel gene URG4

Upregulated gene 4 (URG4), a novel gene located on 7 chromosome (7p13), was found to contribute to hepatocarcinogenesis. However, the role of URG4 in the gastric carcinogenesis still remains unclear. In the present study, URG4 was found by immunohistochemistry to be upregulated in human gastric cancer tissues compared with matched adjacent nonneoplastic tissues. The proliferating cell nuclear antigen index is higher in gastric cancer tissues with high URG4 expression than in those with low URG4 expression. The growth of GES-1 cells, which are immortalized human gastric epithelial mucosa cells with baseline URG4 expression, was accelerated by URG4 induction. Downregulation of URG4 through URG4 small interfering RNA (siRNA) in SGC7901 and MKN28 cells, which had high endogenous URG4 expression, suppressed cell proliferation in both of these cells. URG4-siRNA also inhibited the proliferation of SGC7901 and MKN28 cells in soft agar and tumor formation in nude mice. Overexpression of URG4 in GES cells upregulated cyclin D1, whereas repression of URG4 in SGC7901 and MKN28 cells downregulated cyclin D1. The data suggested that URG4 played an important role in the development of human gastric cancer by regulating the expression of cyclin D1 and might be used as a potential therapeutic target for gastric cancer.

ZNRD1 mediates resistance of gastric cancer cells to methotrexate by regulation of IMPDH2 and Bcl-2

We previously showed that downregulation of a transcription-associated gene (ZNRD1) could reverse the resistant phenotype of gastric cancer cells through regulation of the transcription of multidrug resistance gene 1 (MDR1). In the present study, we determined both known and novel differentially expressed genes in VCR-induced multidrug resistant gastric cancer cell SGC7901/VCR transfected with ZNRD1 siRNA or empty vector control. Screening was performed using the Human Cancer Xpro(tm) HC-III plus arrays, containing 3072 cancer-related cDNAs. Ten genes, involved in cell cycle control, nucleic acid binding, and protein phosphorylation, among other functions, underwent more than 5-fold change. Of the downregulated genes we chose Inosine monophosphate dehydrogenase 2 (IMPDH2) for further validation by quantitative RT-PCR. In vitro and in vivo drug sensitivity analyses revealed that inhibition of ZNRD1 and IMPDH2 activity sensitized SGC7901/VCR cells to methotrexate. Additionally, inhibition of ZNRD1 could suppress adriamycin-induced apoptosis and significantly downregulate the expression of Bcl-2, but it did not alter the expression of the glutathione-S-transferase, or intracellular glutathione content. Taken together, the findings suggest that ZNRD1 could act as a modulator of methotrexate chemotherapy in gastric cancer cells through the regulation of IMPDH2 and Bcl-2.Key words: ZNRD1, IMPDH2, multidrug resistance, apoptosis, gastric cancer.

Zinc ribbon domain-containing 1 (ZNRD1) mediates multidrug resistance of leukemia cells through regulation of P-glycoprotein and Bcl-2

Here, we investigated the role of zinc ribbon domain-containing 1 (ZNRD1) in multidrug resistance (MDR) of leukemia cells and the possible underlying mechanisms. ZNRD1 was found overexpressed in the vincristine-induced MDR leukemia cell HL-60/vincristine moreso than its parental cell HL-60. Up-regulation of ZNRD1 expression could confer resistance of both P-glycoprotein (P-gp)-related and P-gp-nonrelated drugs on HL-60 cells and suppress Adriamycin-induced apoptosis accompanied by decreased accumulation and increased releasing amount of Adriamycin. ZNRD1 could significantly up-regulate the expression of P-gp, Bcl-2, and the transcription of the MDR1 gene but not alter the expression of MDR-associated protein, glutathione S-transferase activity, or intracellular glutathione content in leukemia cells. In addition, inhibition of ZNRD1 expression by RNA interference or P-gp inhibitor could partially reverse ZNRD1-mediated MDR. The further study of the biological functions of ZNRD1 may be helpful for understanding the mechanisms of MDR of leukemia and developing possible strategies to treat leukemia.

Bird's-eye view on gastric cancer research of the past 25 years

This paper provides a bird's-eye view of our 25-year research work on gastric cancer, including both exploration of pathogenesis and preclinical or clinical applications of diagnosis and treatment. Although there have been achievements and reasons for applause, there are, nonetheless, more failings and teachings. Some problems that we experienced 25 years ago are still problems we have to face today. We are absolutely not singing the same old tune. Looking back makes us wiser and our way smoother. Although it is a long and arduous way to further study gastric cancer, we are willing to devote ourselves to it.