Association between CASP-8 gene polymorphisms and cancer risk in some Asian population based on a HuGE review and meta-analysis

Murine leukemia virus (MLV) P50 protein induces cell transformation via transcriptional regulatory function

BACKGROUND

The murine leukemia virus (MLV) has been a powerful model of pathogenesis for the discovery of genes involved in cancer. Its splice donor (SD')-associated retroelement (SDARE) is important for infectivity and tumorigenesis, but the mechanism remains poorly characterized. Here, we show for the first time that P50 protein, which is produced from SDARE, acts as an accessory protein that transregulates transcription and induces cell transformation.

RESULTS

By infecting cells with MLV particles containing SDARE transcript alone (lacking genomic RNA), we show that SDARE can spread to neighbouring cells as shown by the presence of P50 in infected cells. Furthermore, a role for P50 in cell transformation was demonstrated by CCK8, TUNEL and anchorage-independent growth assays. We identified the integrase domain of P50 as being responsible for transregulation of the MLV promoter using luciferase assay and RTqPCR with P50 deleted mutants. Transcriptomic analysis furthermore revealed that the expression of hundreds of cellular RNAs involved in cancerogenesis were deregulated in the presence of P50, suggesting that P50 induces carcinogenic processes via its transcriptional regulatory function.

CONCLUSION

We propose a novel SDARE-mediated mode of propagation of the P50 accessory protein in surrounding cells. Moreover, due to its transforming properties, P50 expression could lead to a cellular and tissue microenvironment that is conducive to cancer development.

Genetic contribution of caspase-8 variants and haplotypes to breast cancer risk and prognosis: a case-control study in Iran

PURPOSE

Multiple genome-wide and candidate-gene association studies have been conducted to search for common risk variants of breast cancer. Recent large meta-analyses and consolidating evidence have highlighted the role of the caspase-8 gene in breast cancer pathogenesis. Therefore, this study aimed to identify common variations and haplotypes associated with risk and overall survival of breast cancer with respect to underlying susceptibility variants in the CASP8 gene region in a group of the Iranian population.

METHODS

In a case-control study with a total of 1008 samples (455 cases and 553 controls), genotyping of 12 candidate polymorphisms, consisting of rs3834129, rs2037815, rs7608692, rs12990906, rs3769821, rs6435074, rs3754934, rs3817578, rs10931936, rs1045485, rs1045487, and rs13113, were performed using PCR-based methods, including ARMS-PCR, AS-PCR, RFLP-PCR, HRM-PCR, and TaqMan-PCR.

RESULTS

rs3834129, rs3754934, rs12990906, and rs10931936 were associated with the risk and overall survival of breast cancer. Several haplotypes were also identified an associated with a higher risk of breast cancer, including a three-SNP haplotype rs3817578-rs10931936-rs1045485 [p < 0.001, OR = 1.78(1.32-2.41)]. rs3754934-C allele showed an association with a lower risk of death in all patients [p = 0.022; HR = 0.46(0.23-0.89)] and in the hormone-receptor-positive group [p = 0.038; HR = 0.37(0.14-0.95)], as well as CC genotype in the hormone-receptor-positive group [p = 0.002; HR = 0.09(0.02-0.43)].

CONCLUSION

The present study suggests a diagnostic and prognostic role of CASP8 gene variations in breast cancer. The risky haplotypes are likely to have one or more underlying breast cancer susceptibility alleles. Understanding the mode of action of these alleles will aid individual-level risk prediction. It also may help identify at-risk patients to provide them with better surveillance.

The Search for Cancer Biomarkers: Assessing the Distribution of INDEL Markers in Different Genetic Ancestries

Cancer is a multifactorial group of diseases, being highly incident and one of the leading causes of death worldwide. In Brazil, there is a great variation in cancer incidence and impact among the different geographic regions, partly due to the genetic heterogeneity of the population in this country, composed mainly by European (EUR), Native American (NAM), African (AFR), and Asian (ASN) ancestries. Among different populations, genetic markers commonly present diverse allelic frequencies, but in admixed populations, such as the Brazilian population, data is still limited, which is an issue that might influence cancer incidence. Therefore, we analyzed the allelic and genotypic distribution of 12 INDEL polymorphisms of interest in populations from the five Brazilian geographic regions and in populations representing EUR, NAM, AFR, and ASN, as well as tissue expression in silico. Genotypes were obtained by multiplex PCR and the statistical analyses were done using R, while data of tissue expression for each marker was extracted from GTEx portal. We highlight that all analyzed markers presented statistical differences in at least one of the population comparisons, and that we found 39 tissues to be differentially expressed depending on the genotype. Here, we point out the differences in genotype distribution and gene expression of potential biomarkers for risk of cancer development and we reinforce the importance of this type of study in populations with different genetic backgrounds.

Transcriptome based analysis of apoptosis genes in chickens co-infected with avian infectious bronchitis virus and pathogenic Escherichia coli

BACKGROUND AND OBJECTIVES

Infection with Infectious bronchitis virus (IBV) and avian pathogenic Escherichia coli (APEC) is an important respiratory infection worldwide. Apoptosis is a physiological process of cell death that occurs as part of normal development and responds to a variety of physiological and pathophysiological stimuli. The identification of molecular mechanisms of action or inaction of key apoptotic proteins is important. This study aimed to investigate apoptotic related genes in the trachea tissue of infected (IBV variant 2, and APEC serotype O78: K80) SPF chickens group compared to the control group.

MATERIALS AND METHODS

Forty SPF chickens was divided into 2 groups. Differential transcriptional profile in the infected SPF chickens trachea tissue was compared to those of control group in the early stage of infection by Illumina RNA-seq technique paired-end and strand-specific sequencing. Differentially expressed genes (DEGs) of transcriptome profiling of the trachea from the infected group were identified. Gene ontology category, KEGG pathway, and STRING analysis were analyzed to identify relationships among differentially expressed genes.

RESULTS

Twenty-eight apoptotic genes were identified. They consisted of six pathways related to cell death: the extrinsic pathway, intrinsic pathway, endoplasmic reticulum stress pathway, MAPK signaling pathway, and cell death by NFkB and activates mTOR pathway and some regulator and apoptosis inhibitors.

CONCLUSION

All of the apoptotic genes in our study were up-regulated. Among these genes, the more fold change value was for TRADD and BCL2A1 genes, and the less fold change value was for MAP3K14, NFKB1, PIK3CB, and ITPR2 genes.

Effects of dihydroartemisinin on HSP70 expression in human prostate cancer PC-3 cells

We aimed to evaluate the effects of dihydroartemisinin (DHA) on heat-shock protein 70 (HSP70) expression in human prostate cancer PC-3 cells and to examine the molecular mechanism. The viability of PC-3 cells following treatment with 25, 50, 100 and 200 μmol/L DHA for 48 hr was detected by flow cytometry and MTT assay. The expression of HSP70 mRNA was detected by RT-qPCR. The expression levels and locations of HSP70, caspase-3 and apoptosis-inducing factor (AIF) were detected with immunofluorescence assay. With 100 μmol/L HSP70 inhibitor quercetin as positive control and dimethyl sulphoxide (DMSO) as solvent control, the protein expressions of HSP70, apoptotic protease activating factor-1 (Apaf-1) and AIF were detected by Western blot. DHA promoted PC-3 cell apoptosis dose-dependently. With increasing DHA dose, the expression of HSP70 mRNA significantly decreased (p < 0.05). DHA did not change the location of HSP70 or AIF. Compared with control and DMSO groups, the expression of HSP70 protein significantly decreased, and those of Apaf-1, caspase-3 and AIF significantly increased following treatment with DHA and quercetin for 48 hr. In conclusion, DHA inhibits the expression of HSP70 and induces the apoptosis of PC-3 cells. The results provide valuable experimental evidence for prostate cancer therapies using DHA.

Association Study of the Caspase Gene Family and Psoriasis Vulgaris Susceptibility in Northeastern China

Background

Abnormal apoptosis of keratinocytes is one of the pathological changes of psoriasis. Caspases (CASPs) are the central engines of apoptosis. Studies to date have shown that some SNPs alter the expression of related genes and lead to changes in disease risk. However, no studies have investigated the associations between gene polymorphisms and the risk of psoriasis in Han population in northeast China. Therefore, we conducted a case-control study to explore this question in Han population of northeastern China.

Methods

540 patients with PsV and 612 healthy age- and sex-matched controls were enrolled in this study. We determined the genotypes of 17 single nucleotide polymorphisms (SNPs) from 11 genes of caspase family by the improved multiplex ligation detection reaction (iMLDR) method. A model-based single SNP frequentist test and haplotype association studies were performed to evaluate the association between SNPs and PsV.

Results

In the single SNP tests, rs6704688 in CASP8 was significantly associated with psoriasis vulgaris (PsV) in Han population of northeastern China (P = 0.0169, P' = 0.0179 under the additive model; P = 0.0126, P' = 0.0149 under the heterozygous model). In haplotype analyses, the CASP7 haplotype GC was found to be associated with PsV risk (case group versus control group, 47.2% versus 54.4%, respectively, p = 0.0149).

Conclusions

Our study presented that the gene polymorphisms of CASP7 and CASP8 were significantly associated with PsV in Han population of northeastern China, which implied the functional relationship between PsV and caspase genes. CASP8 and CASP7 SNPs could be new potential biomarkers for risk stratification and prevention of PsV.

Knockdown of Crispld2 in zebrafish identifies a novel network for nonsyndromic cleft lip with or without cleft palate candidate genes

Orofacial development is a multifaceted process involving tightly regulated genetic signaling networks, that when perturbed, lead to orofacial abnormalities including cleft lip and/or cleft palate. We and others have shown an association between the cysteine-rich secretory protein LCCL domain containing 2 (CRISPLD2) gene and nonsyndromic cleft lip with or without cleft palate (NSCLP). Further, we demonstrated that knockdown of Crispld2 in zebrafish alters neural crest cell migration patterns resulting in abnormal jaw and palate development. In this study, we performed RNA profiling in zebrafish embryos and identified 249 differentially expressed genes following knockdown of Crispld2. In silico pathway analysis identified a network of seven genes previously implicated in orofacial development for which differential expression was validated in three of the seven genes (CASP8, FOS, and MMP2). Single nucleotide variant (SNV) genotyping of these three genes revealed significant associations between NSCLP and FOS/rs1046117 (GRCh38 chr14:g.75746690 T > C, p = 0.0005) in our nonHispanic white (NHW) families and MMP2/rs243836 (GRCh38 chr16:g.55534236 G > A; p = 0.002) in our Hispanic families. Nominal association was found between NSCLP and CASP8/rs3769825 (GRCh38 chr2:g.202111380 C > A; p < 0.007). Overtransmission of MMP2 haplotypes were identified in the Hispanic families (p < 0.002). Significant gene-gene interactions were identified for FOS-MMP2 in the NHW families and for CASP8-FOS in the NHW simplex family subgroup (p < 0.004). Additional in silico analysis revealed a novel gene regulatory network including five of these newly identified and 23 previously reported NSCLP genes. Our results demonstrate that animal models of orofacial clefting can be powerful tools to identify novel candidate genes and gene regulatory networks underlying NSCLP.

Caspase 8 polymorphisms contribute to the prognosis of advanced lung adenocarcinoma patients after platinum-based chemotherapy

Lung cancer is the leading cause of cancer deaths in China, and about 60% of the cases are diagnosed with histological adenocarcinoma. The caspase 8 (CASP8) gene is a critical initiator of the extrinsic apoptosis pathway. To explore the relationship between tagSNPs or haplotypes of CASP8 and the efficacy of platinum-based chemotherapy in advanced lung adenocarcinoma patients of China, we recruited 555 advanced adenocarcinoma patients. We extracted the genomic DNA from patients' peripheral blood samples and sequenced tagSNPs of CASP8. We calculated the individual haplotype of CASP8 frequencies using the PHASE 2.0 program. The association between CASP8 tagSNPs and overall survival (OS) was calculated by univariate and multivariate Cox regression analysis. A univariate logistic regression analysis was done to analyze the CASP8 tagSNPs and the toxicity of platinum-based chemotherapy. The same statistical methods were used for exploring haplotypes of CASP8. Rs3769821 and rs1045494 of CASP8 were independent prognosis factors for overall survival (OS) using multivariate Cox's regression models. For the haplotype of the 7 tagSNPs, haplotype AGGAAAGA was correlated with the efficacy of platinum-based chemotherapy. The polymorphisms of CASP8, rs7608692, and haplotype AGAACAG correlated with neutropenia toxicity. The haplotype GGGGAAA was associated with thrombocytopenia toxicity. We conclude that the polymorphisms of CASP8 contribute to the prognosis of advanced lung adenocarcinoma and influence the quality of life and survival.

CASP8 -652 6N insertion/deletion polymorphism and overall cancer risk: evidence from 49 studies

The CASP8 -652 6N insertion/deletion (I/D) polymorphism reduces expression of caspase 8. We conducted a meta-analysis to clarify the relationship between this polymorphism and cancer risk. Eligible articles were retrieved from PubMed, EMBASE, CNKI, and WANFANG databases through February 2017. A total of 33 articles with 49 studies, including 33,494 cases and 36,397 controls, were analyzed. We found that the CASP8 -652 6N ins/del polymorphism was associated with decreased overall cancer risk in five genetic models [DD vs. II: odds ratio (OR)=0.76, 95% confidence interval (CI)=0.69–0.84, ID vs. II: OR=0.87, 95% CI=0.83–0.92, DD vs. ID/II: OR=0.82, 95% CI=0.75–0.89, ID/DD vs. II: OR=0.85, 95% CI=0.80–0.90, and D vs. I: OR=0.87, 95% CI=0.83–0.91]. Stratified analyses showed that the polymorphism was associated with decreased risk of colorectal, breast, esophageal, renal cell, lung, cervical, bladder, gastric, and other cancers. Overall cancer risk was reduced in Asian and Caucasian patients, both hospital- and population-based studies, and both high and low quality studies. Our results highlight the role of the CASP8 -652 6N ins/del polymorphism in decreasing cancer risk. Further studies with large-cohort populations, especially for specific cancer types and ethnic groups, are needed to confirm our findings.