KRAS rs7973450 A>G increases neuroblastoma risk in Chinese children: a four-center case-control study

Association between KRAS gene polymorphisms and genetic susceptibility to breast cancer in a Chinese population

OBJECTIVE

The KRAS gene has a pathophysiological role in the development of many cancers. This study aims to investigate the relationship between KRAS polymorphisms and genetic susceptibility to breast cancer.

METHOD

The rs712, rs12587 and rs9266 gene loci in the KRAS gene of 421 subjects (141 breast cancer patients, 141 benign breast tumours and 139 healthy controls) were analysed by the polymerase chain reaction and SNaPshot sequencing. Transcriptomic information on KRAS and corresponding clinical information was downloaded from the TCGA and GTEx databases. Differences in KRAS expression between breast cancer tissues and control tissues were analysed.

RESULTS

We found no significant association between KRAS rs712 and rs12587 locus gene polymorphisms and an increased risk of developing benign breast tumours and breast cancer (p > 0.05). The KRAS rs9266 locus mutation heterozygous model CT and dominant model CT + TT were significantly associated with an increased risk of breast cancer (both p < 0.05). In addition, the TAT haplotype was expressed at an increased frequency, and the GAC haplotype was expressed at a reduced frequency in breast cancer compared with controls (both p < 0.05). We found that KRAS was over expressed in breast cancer tumour tissues compared with the control tissues (p < 0.0001).

CONCLUSION

The KRAS rs9266 gene polymorphism and the TAT haplotype may be associated with an increased risk of breast cancer in Chinese women. The GAC haplotype may be a protective factor against breast cancer.

Associations of Polymorphisms Localized in the 3'UTR Regions of the KRAS, NRAS, MAPK1 Genes with Laryngeal Squamous Cell Carcinoma

Background: Genetic variations, localized in the 3′ untranslated region (UTR) in mitogen-activated protein kinase (MAPK) pathway-related genes, may alter the transcription and impact the pathogenesis of laryngeal squamous cell carcinoma (LSCC). The present study investigated the associations of single-nucleotide polymorphisms (SNP), localized in the 3′UTR) of the KRAS, NRAS, and MAPK1 genes with LSCC risk and clinicopathological features. Methods: Genomic DNA and clinical data were collected from 327 adult men with LSCC. The control group was formed from 333 healthy men. Genotyping of the SNPs was performed using TaqMan SNP genotyping assays. Five KRAS, NRAS, and MAPK1 polymorphisms were analyzed. All studied genotypes were in Hardy–Weinberg equilibrium and had the same allele distribution as the 1000 Genomes project Phase 3 dataset for the European population. Results: Significant associations of the studied SNPs with reduced LSCC risk were observed between NRAS rs14804 major genotype CC. Significant associations of the studied SNPs with clinicopathologic variables were also observed between NRAS rs14804 minor T allele and advanced tumor stage and positive lymph node status. SNP of MAPK1 rs9340 was associated with distant metastasis. Moreover, haplotype analysis of two KRAS SNPs rs712 and rs7973450 revealed that TG haplotype was associated with positive lymph node status in LSCC patients. Conclusions: According to the present study, 3′UTR SNP in the NRAS and MAPK1 genes may contribute to the identifications of patients at higher risk of LSCC lymph node and distant metastasis development.

Bioinformatics Analysis of Neuroblastoma miRNA Based on GEO Data

Objective

To analyze the changes in downstream genes, signaling pathways, and proteins based on the difference of microRNA (miRNA) expression in neuroblastoma (NB).

Methods

GSE128004 second-generation sequencing expression data were downloaded from GEO, and Limma package of R language was used to analyze differential expression, and a volcano map and heat map were drawn; the target genes corresponding to the differential miRNA were found using the miWalk web tool, and GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) were performed. The key genes were identified and verified in the TCGA database.

Results

A total of 34 differentially expressed miRNAs were screened out. Among them, 22 up-regulated miRNAs predicted 1163 target genes and 12 down-regulated miRNAs predicted 1474 target genes. Target genes were enriched and analyzed by KEGG to find the FOXO signal pathway, mTOR signal pathway, AMPK signal pathway, and other signal pathways. After GO analysis, axon formation, regulation of chemical synaptic transmitters, regulation of nerve synapses, regulation of cross-synaptic signals, and other physiological processes were assessed. A total of 16 key genes were obtained by PPI analysis, and the survival analysis of TP53 and ATM genes verified in the TCGA database showed statistical significance.

Conclusion

The 34 differential miRNAs may be related to the occurrence and development of NB. TP53 and ATM are related to the prognosis of NB. The role and mechanism of TP53 and ATM in NB need to be further verified.

Association of MYC gene polymorphisms with neuroblastoma risk in Chinese children: A four-center case-control study

BACKGROUND

Neuroblastoma is one of the most common malignant tumors in childhood. Polymorphisms in proto-oncogene MYC are implicated in many cancers, although their role in neuroblastoma remains unclear. In the present study, we attempted to investigate the association between MYC gene polymorphisms and neuroblastoma susceptibility in Chinese children.

METHODS

We included two MYC polymorphisms (rs4645943 and rs2070583) and assessed their effects on neuroblastoma risk in 505 cases and 1070 controls via the Taqman method.

RESULTS

In single and combined locus analysis, no significant association was found between the two selected polymorphisms and neuroblastoma susceptibility. In stratification analysis, the rs4645943 CT/TT genotypes were significantly associated with a decreased neuroblastoma risk in subjects with tumors originating from other sites [adjusted odds ratio (OR) = 0.42, 95% confidence interval (CI) = 0.21-0.84, p = 0.013]. Meanwhile, the presence of one or two protective genotypes was significantly associated with a decreased neuroblastoma risk in subjects with tumors arising from other sites (adjusted OR = 0.50, 95% CI = 0.26-0.96, p = 0.036).

CONCLUSIONS

The present study indicates that MYC gene polymorphisms may have a weak effect on the neuroblastoma risk, which neeeds to be verified further.