Is BRD7 associated with spermatogenesis impairment and male infertility in humans? A case-control study in a Han Chinese population

Background

Bromodomain-containing protein 7 (BRD7), a member of the bromodomain-containing protein family, plays important roles in chromatin modification and transcriptional regulation. A recent model of Brd7-knockout mice presented azoospermia and male infertility, implying the potential role of BRD7 in spermatogenic failure in humans. This case-control study aimed to explore the association of the BRD7 gene with spermatogenic efficiency and the risk of spermatogenic defects in humans.

Results

A total of six heterozygous variants were detected in the coding and splicing regions of the BRD7 gene in patients with azoospermia. For each of four rare variants predicted to potentially damage BRD7 function, we further identified these four variants in oligozoospermia and normozoospermia as well. However, no difference in the allele and genotype frequencies of rare variants were observed between cases with spermatogenic failure and controls with normozoospermia; the sperm products of variant carriers were similar to those of noncarriers. Moreover, similar distribution of the alleles, genotypes and haplotypes of seven tag single nucleotide polymorphisms (tagSNPs) was observed between the cases with azoospermia and oligozoospermia and controls with normozoospermia; associations of tagSNP-distinguished BRD7 alleles with sperm products were not identified.

Conclusions

The lack of an association of BRD7-linked rare and common variants with spermatogenic failure implied a limited contribution of the BRD7 gene to spermatogenic efficiency and susceptibility to male infertility in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12610-021-00139-3.

The A/A Genotype of XPO1 rs4430924 Is Associated With Higher Risk of Antituberculosis Drug-Induced Hepatotoxicity in Chinese Patients

Antituberculosis (anti-TB) drug-induced hepatotoxicity may be related to the excessive reactive oxygen species induced by hepatotoxic metabolites. Antioxidant activity involves the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. The BTB domain and CNC homologue 1 (Bach1) may compete with Nrf2 for binding to transcriptional enhancers. Elimination of Bach1-mediated transcriptional repression depends on nuclear exporter exportin 1 (Xpo1). Thus, Xpo1 may indirectly affect antioxidant activity. The present study aimed to examine the role of tag single-nucleotide polymorphisms in XPO1 in Chinese anti-TB treatment patients. A 1:2 matched case-control study was conducted using 314 anti-TB drug-induced hepatotoxicity cases and 628 controls. After correcting for weight and hepatoprotectant use, conditional logistic regression analysis showed that patients carrying the AA genotype of rs4430924 in XPO1 were at higher risk of anti-TB drug-induced hepatotoxicity than those carrying the GG genotype based on the subgroup of probable cases (adjusted OR, 1.938; 95%CI, 1.035-3.628; P = .039), and marginally significant differences were also found under the recessive model (P = .048) and the additive model (P = .047). Based on this 1:2 matched case-control study, the AA genotype of rs4430924 in XPO1 may be associated with higher risk of anti-TB drug-induced hepatotoxicity in Chinese anti-TB treatment patients. Further studies in larger and more varied populations are required to validate this relationship.

Genetic variations in cancer-related significantly mutated genes and lung cancer susceptibility

Background

Cancer initiation and development are driven by key mutations in driver genes. Applying high-throughput sequencing technologies and bioinformatic analyses, The Cancer Genome Atlas (TCGA) project has identified panels of somatic mutations that contributed to the etiology of various cancers. However, there are few studies investigating the germline genetic variations in these significantly mutated genes (SMGs) and lung cancer susceptibility.

Patients and methods

We comprehensively evaluated 1655 tagged single nucleotide polymorphisms (SNPs) located in 127 SMGs identified by TCGA, and test their association with lung cancer risk in large-scale case-control study. Functional effect of the validated SNPs, gene mutation frequency and pathways were analyzed.

Results

We found 11 SNPs in 8 genes showed consistent association (P < 0.1) and 8 SNPs significantly associated with lung cancer risk (P < 0.05) in both discovery and validation phases. The most significant association was rs10412613 in PPP2R1A, with the minor G allele associated with a decreased risk of lung cancer [odds ratio = 0.91, 95% confidence interval (CI): 0.87-0.96, P = 2.3 × 10-4]. Cumulative analysis of risk score built as a weight sum of the 11 SNPs showed consistently elevated risk with increasing risk score (P for trend = 9.5 × 10-9). In stratified analyses, the association of PPP2R1A:rs10412613 and lung cancer risk appeared stronger among population of younger age at diagnosis and never smokers. The expression quantitative trait loci analysis indicated that rs10412613, rs10804682, rs635469 and rs6742399 genotypes significantly correlated with the expression of PPP2R1A, ATR, SETBP1 and ERBB4, respectively. From TCGA data, expression of the identified genes was significantly different in lung tumors compared with normal tissues, and the genes' highest mutation frequency was found in lung cancers. Integrative pathway analysis indicated the identified genes were mainly involved in AKT/NF-κB regulatory pathway suggesting the underlying biological processes.

Conclusion

This study revealed novel genetic variants in SMGs associated with lung cancer risk, which might contribute to elucidating the biological network involved in lung cancer development.

Association of TagSNP in lncRNA HOTAIR with susceptibility to noise-induced hearing loss in a Chinese population

BACKGROUND

Noise-induced hearing loss (NIHL) is a multifactorial disease, and dysregulation of oxidative stress is universally acknowledged as one crucial pathogenic factor for this disease. Recently studies have found the LncRNA HOTAIR is involved in the alteration of oxidative stress level, cell proliferation, cell cycle progression, and apoptosis. Considering the effects of lncRNA HOTAIR in cellular oxidative stress, we sought to investigate the influence of lncRNA HOTAIR variants on the risk of NIHL.

METHODS

To explore the effects of HOTAIR polymorphisms on individual susceptibility to NIHL, We performed genotyping of three tagSNPs (rs874945, rs4759314 and rs7958904) in HOTAIR gene in a Chinese population which consists of 570 NIHL cases and 570 controls. The luciferase assays were further performed to investigate the regulatory function of HOTAIR tagSNPs.

RESULTS

Our results revealed individuals with the G allele of HOTAIR tagSNP rs4759314 and the haplotype (rs874945, rs4759314 and rs7958904) are associated with an increased risk of NIHL in a Chinese population. Meanwhile, the rs4759314 G allele could significantly increase the expression of lncRNA HOTAIR.

CONCLUSIONS

The genetic polymorphism within HOTAIR gene may play a crucial role in the occurrence and development of NIHL.

Genetic association of gastric cancer with miRNA clusters including the cancer-related genes MIR29, MIR25, MIR93 and MIR106: results from the EPIC-EURGAST study

MicroRNAs (miRNAs) are post-transcriptional gene regulators involved in a wide range of biological processes including tumorigenesis. Deregulation of miRNA pathways has been associated with cancer but the contribution of their genetic variability to this disorder is poorly known. We analyzed the genetic association of gastric cancer (GC) and its anatomical and histological subtypes, with 133 single-nucleotide polymorphisms (SNPs) tagging 15 isolated miRNAs and 24 miRNA clusters potentially involved in cancer, in 365 GC cases and 1,284 matched controls within the European Prospective Investigation into Cancer and Nutrition cohort. Various SNPs were associated with GC under the log-additive model. Furthermore, several of these miRNAs passed the gene-based permutation test when analyzed according to GC subtypes: three tagSNPs of the miR-29a/miR-29b-1 cluster were associated with diffuse subtype (minimum p-value = 1.7 × 10(-4) ; odds ratio, OR = 1.72; 95% confidence interval, CI = 1.30-2.28), two tagSNPs of the miR-25/miR-93/miR-106b cluster were associated with cardia GC (minimum p-value = 5.38 × 10(-3) ; OR = 0.56, 95% CI = 0.37-0.86) and one tagSNP of the miR-363/miR-92a-2/miR-19b-2/miR-20b/miR-18b/miR-106a cluster was associated with noncardia GC (minimum p-value = 5.40 × 10(-3) ; OR = 1.41, 95% CI = 1.12-1.78). Some functionally validated target genes of these miRNAs are implicated in cancer-related processes such as methylation (DNMT3A, DNMT3B), cell cycle (E2F1, CDKN1A, CDKN1C), apoptosis (BCL2L11, MCL1), angiogenesis (VEGFA) and progression (PIK3R1, MYCN). Furthermore, we identified genetic interactions between variants tagging these miRNAs and variants in their validated target genes. Deregulation of the expression of these miRNAs in GC also supports our findings, altogether suggesting for the fist time that genetic variation in MIR29, MIR25, MIR93 and MIR106b may have a critical role in genetic susceptibility to GC and could contribute to the molecular mechanisms of gastric carcinogenesis.

Relationship between interleukin 18 polymorphisms and susceptibility to chronic hepatitis B virus infection

AIM

To identify the relationship between the tagging single nucleotide polymorphism sites (tagSNPs) of the Interleukin-18 (IL-18) gene and genetic susceptibility to chronic hepatitis B virus infection in Chinese patients.

METHODS

Five hundred and one cases of chronic hepatitis B virus (HBV) infection and 301 HBV natural clearance controls were studied. Two tagSNPs in the IL-18 gene (rs1946518A/C and rs574424C/G) were genotyped by the Multiplex Snapshot technique. The genotype and allele frequencies were calculated and analyzed.

RESULTS

In the genotypes of rs1946518, the AA type was present at a higher frequency in the patients compared to those in the controls. Odds ratio (OR) of the AA genotype for the comparison with that of the AC and the CC genotype was 1.537 (95% confidence intervals (CI): 1.116-2.218, P = 0.009 < 0.025). In phenotypes, the allele C at rs1946518 was of a significantly lower frequency in the patients with chronic hepatitis B than that in the controls (P = 0.017 < 0.025). OR of the allele A for the comparison with that of the allele C was 1.279 (95% CI: 1.045-1.567). As for the rs574424 genotypes, no significant difference in this genotype distribution or in this allele frequency between the patients and the control subjects was observed. No significant difference in the haplotype frequencies between the patients with chronic hepatitis B and HBV natural clearance individuals was displayed.

CONCLUSION

The data suggest that genotype AA and the allele A of the IL-18 at position rs1946518 are closely associated with the resistance to chronic hepatitis B and may be the dangerous gene. However, no statistical association was found between polymorphisms of rs574424 for IL-18 and hepatitis B.