The Principal Genetic Determinants for Nasopharyngeal Carcinoma in China Involve the HLA Class I Antigen Recognition Groove

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy facilitated by Epstein-Barr Virus infection. Here we resolve the major genetic influences for NPC incidence using a genome-wide association study (GWAS), independent cohort replication, and high-resolution molecular HLA class I gene typing including 4,055 study participants from the Guangxi Zhuang Autonomous Region and Guangdong province of southern China. We detect and replicate strong association signals involving SNPs, HLA alleles, and amino acid (aa) variants across the major histocompatibility complex-HLA-A, HLA –B, and HLA -C class I genes (PHLA-A-aa-site-62 = 7.4×10−29; P HLA-B-aa-site-116 = 6.5×10−19; P HLA-C-aa-site-156 = 6.8×10−8 respectively). Over 250 NPC-HLA associated variants within HLA were analyzed in concert to resolve separate and largely independent HLA-A, -B, and -C gene influences. Multivariate logistical regression analysis collapsed significant associations in adjacent genes spanning 500 kb (OR2H1, GABBR1, HLA-F, and HCG9) as proxies for peptide binding motifs carried by HLA- A*11:01. A similar analysis resolved an independent association signal driven by HLA-B*13:01, B*38:02, and B*55:02 alleles together. NPC resistance alleles carrying the strongly associated amino acid variants implicate specific class I peptide recognition motifs in HLA-A and -B peptide binding groove as conferring strong genetic influence on the development of NPC in China

Analytical “Bake-Off” of Whole Genome Sequencing Quality for the Genome Russia Project Using a Small Cohort for Autoimmune Hepatitis

A comparative analysis of whole genome sequencing (WGS) and genotype calling was initiated for ten human genome samples sequenced by St. Petersburg State University Peterhof Sequencing Center and by three commercial sequencing centers outside of Russia. The sequence quality, efficiency of DNA variant and genotype calling were compared with each other and with DNA microarrays for each of ten study subjects. We assessed calling of SNPs, indels, copy number variation, and the speed of WGS throughput promised. Twenty separate QC analyses showed high similarities among the sequence quality and called genotypes. The ten genomes tested by the centers included eight American patients afflicted with autoimmune hepatitis (AIH), plus one case’s unaffected parents, in a prelude to discovering genetic influences in this rare disease of unknown etiology. The detailed internal replication and parallel analyses allowed the observation of two of eight AIH cases carrying a rare allele genotype for a previously described AIH-associated gene (FTCD), plus multiple occurrences of known HLA-DRB1 alleles associated with AIH (HLA-DRB1-03:01:01, 13:01:01 and 7:01:01). We also list putative SNVs in other genes as suggestive in AIH influence

Signal Localization: A New Approach in Signal Discovery

A new approach for statistical association signal identification is developed in this paper. We consider a strategy for nonprecise signal identification by extending the well-known signal detection and signal identification methods applicable to the multiple testing problem. Collection of statistical instruments under the presented approach is much broader than under the traditional signal identification methods, allowing more efficient signal discovery. Further assessments of maximal value and average statistics in signal discovery are improved. While our method does not attempt to detect individual predictors, it instead detects sets of predictors that are jointly associated with the outcome. Therefore, an important application would be in genome wide association study (GWAS), where it can be used to detect genes which influence the phenotype but do not contain any individually significant single nucleotide polymorphism (SNP). We compare power of the signal identification method based on extremes of single p-values with the signal localization method based on average statistics for logarithms of p-values. A simulation analysis informs the application of signal localization using the average statistics for wide signals discovery in Gaussian white noise process. We apply average statistics and the localization method to GWAS to discover better gene influences of regulating loci in a Chinese cohort developed for risk of nasopharyngeal carcinoma (NPC)

Prognostic Significance of Neutrophil to Lymphocyte Ratio, Lymphocyte to Monocyte Ratio, and Platelet to Lymphocyte Ratio in Patients with Nasopharyngeal Carcinoma

The peripheral blood neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), and platelet to lymphocyte ratio (PLR) have been reported to correlate with the prognosis of many malignancies. This study evaluated the prognostic value of pretreatment NLR, LMR, and PLR in nasopharyngeal carcinoma (NPC). A retrospective analysis of clinical and pathological data of 140 NPC patients without distant metastasis during initial treatment was conducted to identify correlations between NLR, LMR, and PLR and clinicopathological features, overall survival, and progression-free survival. Cox proportional hazard regression analysis was used to reveal the independent factors affecting the prognosis of NPC patients. NLR was associated with T staging, N staging, and overall clinical stage grouping of the NPC patients (P<0.05). NLR ≥ 2.28, LMR < 2.26, and PLR ≥ 174 were significantly associated with a relatively short overall survival (P<0.05). In addition, NLR ≥ 2.28 was significantly associated with a relatively short progression-free survival (P<0.05). Cox proportional hazard regression analysis showed that NLR was an independent prognostic factor in NPC. Pretreatment NLR, LMR, and PLR might be a useful complement to TNM staging in the prognostic assessment of NPC patients

Expression and Prognostic Significance of Macrophage Inflammatory Protein-3 Alpha and Cystatin A in Nasopharyngeal Carcinoma

This study aims to investigate the expression of macrophage inflammatory protein-3 alpha (MIP-3α) and cystatin A in nasopharyngeal carcinoma (NPC) and their association with clinical characteristics and prognosis. Primary tumor specimens from 114 NPC patients and associated clinical follow-up data were collected, and the expression of MIP-3α and cystatin A proteins was investigated by immunohistochemistry. Expression of MIP-3α was significantly associated with TNM stage in patients with NPC (P<0.05). NPC patients with positive expression of MIP-3α exhibited shorter median overall survival (OS) and distant metastasis-free survival (DMFS), compared with patients with negative expression (OS: 50.5 months versus 59.0 months, P=0.013; DMFS: 50.1 months versus 60.2 months, P=0.003). NPC patients with positive expression of cystatin A exhibited shorter median OS, local recurrence-free survival (LRFS), and DMFS, compared with patients with negative expression (OS: 51.1 months versus 60.0 months, P=0.004; LRFS: 54.5 months versus 59.5 months, P=0.036; DMFS: 52.3 months versus 58.8 months, P=0.036). Both MIP-3α and cystatin A overexpressions in NPC tumor tissues were strong independent factors of poor prognosis in NPC patients. MIP-3α and cystatin A expressions may be valuable prognostic markers in NPC patients

Evaluation and Integration of Genetic Signature for Prediction Risk of Nasopharyngeal Carcinoma in Southern China

Genetic factors, as well as environmental factors, play a role in development of nasopharyngeal carcinoma (NPC). A number of single nucleotide polymorphisms (SNPs) have been reported to be associated with NPC. To confirm these genetic associations with NPC, two independent case-control studies from Southern China comprising 1166 NPC cases and 2340 controls were conducted. Seven SNPs in ITGA9 at 3p21.3 and 9 SNPs within the 6p21.3 HLA region were genotyped. To explore the potential clinical application of these genetic markers in NPC, we further evaluate the predictive/diagnostic role of significant SNPs by calculating the area under the curve (AUC). Results. The reported associations between ITGA9 variants and NPC were not replicated. Multiple loci of GABBR1, HLA-F, HLA-A, and HCG9 were statistically significant in both cohorts (Pcombined range from 5.96 × 10−17 to 0.02). We show for the first time that these factors influence NPC development independent of environmental risk factors. This study also indicated that the SNP alone cannot serve as a predictive/diagnostic marker for NPC. Integrating the most significant SNP with IgA antibodies status to EBV, which is presently used as screening/diagnostic marker for NPC in Chinese populations, did not improve the AUC estimate for diagnosis of NPC