Association of a MYCL1 Single Nucleotide Polymorphism, rs3134613, with Susceptibility to Diffuse-Type Gastric Cancer and with Differentiation of Gastric Cancer in a Southeast Chinese Population

Investigation of the association between the Toll-like receptor 1 rs4833095 variation and gastric adenocarcinoma recurrence

BACKGROUND

Toll-like receptors (TLRs) are a family of transmembrane receptors that play key roles in identifying invading pathogens and activating innate immunity. TLR1 has been reported to be associated with the risk of gastric cancer (GC) but that was based on only a simple statistical analysis.

METHODS

We genotyped the TLR1 in 526 GC patients to investigate the association between the variation and gastric cancer survival by the multiplex polymerase chain reaction and sequencing method. The rs4833095 variation (chr4:38798089 [GRCh38. p14], T > C) in the TLR1 gene was genotyped in 526 patients who underwent GC resection. The associations between genotype, survival, and recurrence were investigated. The potential role of TLR1 in stomach cancer was investigated using clinical data from formalin-fixed, paraffin-embedded tissue samples.

RESULTS

Patients with the T/C and C/C genotypes of rs4833095 had a lower risk of recurrence than those with the T/T genotype. Recurrence-free periods were substantially longer in patients with the T/C or C/C genotypes (22.6 and 22.3 months, respectively) than in those with the T/T genotype (20.7 months). Patients with the T/C or C/C genotype, low expression levels of VEGF1, high expression levels of ERBB2 and ERCC1, the absence of cancer nodules, a tumor size of less than 5 cm, and poor differentiation had a considerably reduced risk of recurrence.

CONCLUSIONS

TLR1 rs4833095 was correlated with the postresection prognosis of patients with gastric cancer, suggesting that TLR1 may have a role in the onset or progression of gastric cancer.

Targeted silencing of MYCL1 by RNA interference inhibits migration and invasion of MGC-803 gastric cancer cells

MYCL1 protein expression encoded by a proto-oncogene MYCL1, a member of the MYC family, is correlated with poor prognosis in gastric cancer patients. Nevertheless, the role of MYCL1 in gastric cancer cells remains unknown. In this study, the expression levels of MYCL1 mRNA and protein were downregulated by lentiviral-mediated RNA interference (RNAi) in the MGC-803 gastric cancer cell line. Then, the influence of MYCL1 on the biological behaviour of gastric cancer cells was investigated. Finally, a stable animal model of the MGC-803 human gastric cancer tumour model in nude mice was made successfully. Functionally, silencing of MYCL1 inhibited migration and invasion of the MGC-803 line in vitro and was accompanied with some ultrastructural changes. These results provide some evidences that lentiviral-mediated MYCL1 silencing may be a novel therapeutic strategy for the treatment of gastric cancer. SIGNIFICANCE OF THE STUDY: Gastric cancer is one of the most common malignant tumours worldwide and the second leading cause of cancer-related death in China. Our previous study revealed that expression of MYCL1 in gastric cancer tissue was associated with poor prognosis of patients. However, the potential underlying mechanism is still unclear. In the current study, we displayed the influence of MYCL1 gene on invasion and migration phenotype of gastric cancer cells and provided a possible explanation from the aspect of structural alteration. Our results suggested that downregulation of MYCL1 may be a potential therapeutic strategy for gastric cancer.

Genetic variants in XDH are associated with prognosis for gastric cancer in a Chinese population

OBJECTIVE

We explored the association between single nucleotide polymorphisms (SNPs) rs207454 and rs494852 located in xanthine dehydrogenase (XDH) and gastric cancer (GC) survival.

METHODS

A total of 940 patients with gastric cancer were enrolled and genotyped using TaqMan allelic discrimination method. The Kaplan-Meier test and log-rank examine were used to assess the effect of genetic variation.

RESULTS

Patients carrying rs207454 CC genotype had a longer survival time than those with the AA genotype (P = 0.042). The similar association was detected in the recessive model (P = 0.017). We conducted expression quantitative trait loci (eQTL) analysis and found that gastric cancer patients carrying rs207454 CC genotype had significant lower XDH levels than those with AA/AC genotype, suggesting that rs207454 polymorphism effected the expression of XDH. Additionally, the Kaplan-Meier curves showed that gastric cancer patients with high expression of XDH had remarkably poor survival outcome than those with low expression (hazard ratio [HR] = 1.53, 95% confidence interval [CI] = 1.29-1.82).

CONCLUSIONS

Genetic variants in XDH were associated with the survival of gastric cancer and may act as prognostic markers for individual suffered from gastric cancer.

Expression and prognostic value of Mycl1 in gastric cancer

As a member of the Myc proto-oncogene family, MYCL1 has been found to be amplified and overexpressed in some malignancies. However, the clinical significance of Mycl1 expression in gastric cancer is still unknown. Mycl1 expression was detected on tissue microarrays of gastric cancer samples in 176 cases using immunohistochemical staining, and its association with clinicopathological factors and overall survival was also analyzed. Mycl1 showed greater expression in gastric cancer tissue than in adjacent normal tissue (62.5% vs 46.0%, respectively, P=0.002), and its expression was correlated with patient age, tumor differentiation, and TNM stage (P=0.007, 0.003, and 0.002, respectively). The Mycl1 positive group had an unfavorable outcome compared with the negative group (P<0.001). Multivariate analysis showed that Mycl1 expression was an independent prognostic factor of gastric cancer (P=0.009). These results suggest that Mycl1 expression might be useful as a biomarker to predict prognosis and is a promising therapeutic target for patients with gastric cancer.

Genetic variation in C12orf51 is associated with prognosis of intestinal-type gastric cancer in a Chinese population

Recent genome-wide association study (GWAS) on esophageal squamous-cell carcinoma (ESCC) among Chinese population has identified two novel single nucleotide polymorphisms (SNPs) rs11066280 and rs2074356 on C12orf51 gene. We hypothesized that SNPs rs11066280 and rs2074356 could influence gastric cancer survival outcomes. We genotyped the SNPs rs11066280 and rs2074356 in 940 patients with surgically resected gastric cancer. Analyses of genotype association with survival outcomes were assessed by the Kaplan-Meier method, Cox proportional hazards models and the log-rank test. There was no significant association between rs11066280 and survival of gastric cancer. However, in the stratification analysis of histology, we found that the rs11066280 TA/AA genotypes were associated with a poor survival of intestinal-type gastric cancer (log-rank P=0.041, hazard ratio [HR]=1.40, 95% confidence interval [CI]=1.02-1.93), Moreover, this hazardous effect was more prominent among patients with tumor size>5cm, no distant metastasis, chemotherapy and drinking. No significant association was observed between rs2074356 and the survival of gastric cancer. C12orf5 rs11066280 could be useful marker of survival assessment and individualized clinical therapy for gastric cancer, particularly among the intestinal-type gastric cancer.

Association of polymorphisms and haplotype in the region of TRIT1, MYCL1 and MFSD2A with the risk and clinicopathological features of gastric cancer in a southeast Chinese population

To explore the association of polymorphisms in the region of three neighboring genes TRIT1, MYCL1 and MFSD2A with risk and clinicopathological features of gastric cancer, 19 tagging SNPs in this region were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in a case-control study of 610 Chinese gastric cancer patients and 608 cancer-free controls. MFSD2A rs4233508 T>C CC genotype was associated with an increased risk of gastric cancer in younger patients and an increased risk of moderately/well-differentiated intestinal-type gastric cancer (adjusted odds ratio [OR], 1.74 and 1.50, respectively). TRIT1 rs11581557 T>G TG was associated with lymph node metastasis (TG versus TT/GG, adjusted OR, 1.64). MFSD2A rs12083239 GC genotype and TRIT1 rs2172362 or rs230310 homozygous genotype were associated with Lauren's classification (GC versus GG, adjusted OR, 1.69; GC versus GG/CC, adjusted OR, 1.74) and tumor site (rs2172362: CC versus CT, adjusted OR, 1.71; CC/TT versus CT, adjusted OR, 1.62; rs230310: CC versus CT, adjusted OR, 1.75; CC/TT versus CT, adjusted OR, 1.67) of gastric cancer, respectively. One TRIT1 haplotype, CCGT, was associated with lymph node metastasis and tumor site of gastric cancer (CCGT versus TTTT, adjusted OR, 1.91 and 1.55). This is believed to be the first report that several tagging SNPs and haplotypes in TRIT1, MYCL1 and MFSD2A region are significantly associated with risk and clinicopathological features of gastric cancer in a Chinese population. The findings might be useful for risk assessment and prognosis prediction of gastric cancer.

Genetic variation in PLCE1 is associated with gastric cancer survival in a Chinese population

BACKGROUND

Two genome-wide association studies on gastric cancer showed a previously unknown gastric cancer susceptible locus in PLCE1 at 10q23. We hypothesized that the single nucleotide polymorphism (SNP) rs2274223 A/G is associated with the survival rate of gastric cancer.

METHODS

We genotyped the above SNP in 940 gastric cancer patients to investigate the association between the polymorphism and gastric cancer survival by the TaqMan method.

RESULTS

We found that patients carrying PLCE1 rs2274223 AA genotype survived for a significantly shorter time than those carrying the AG and GG genotypes (log-rank P = 0.046). This significance was enhanced in the dominant model (AA vs. AG/GG, log-rank P = 0.014). Multivariate Cox regression analyses showed that the AG/GG genotypes were associated with a significantly decreased risk of death from gastric cancer [adjusted hazard ratio (HR) = 0.79, 95% confidence interval (CI) = 0.65-0.95]. Most of stratification analysis did not find an enhanced association between the same genotype and prognosis, except for patients with TNM stage III disease (HR = 0.63, 95% CI = 0.48-0.83).

CONCLUSION

Our findings showed that the PLCE1 SNP rs2274223 was associated with significantly improved gastric cancer survival in a Chinese population. Further functional studies are needed to validate our results.

Positive association of CC2D1A and CC2D2A gene haplotypes with mental retardation in a Han Chinese population

The CC2D1A and CC2D2A genes are involved in Ca(2+)-regulated signaling pathways and have recently been implicated in the etiology of mental retardation (MR). The aim of this study was to investigate whether CC2D1A and CC2D2A polymorphisms are associated with susceptibility to MR in a Han Chinese population using a family based association approach. The sample included 172 trios (parents and offspring), and all subjects were genotyped for several single-nucleotide polymorphisms covering CC2D1A and CC2D2A. Linkage disequilibrium (LD) analysis revealed that the rs6511901 and rs10410239 polymorphisms of CC2D1A were in strong LD (D'=0.865), and haplotype analysis showed evidence for over-transmission from parents to MR offspring (p=0.0009). The LD analysis also revealed that CC2D2A single-nucleotide polymorphisms rs10025837, rs13116304, and rs7661102 were in strong LD (D'=0.848), and haplotype analysis showed significant transmission disequilibrium (p=0.0004). The results suggest the involvement of CC2D1A and CC2D2A in MR in the Han Chinese population, and some specific haplotypes may be susceptible or protective.