Rare frequencey of point mutations for codon 12, 13 and 61 of ras gene in italian neuroblastoma

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

BACKGROUND

Neuroblastoma is one of the most common extracranial solid pediatric tumors. KRAS plays an important role in regulating cell proliferation, differentiation, and apoptosis. Single nucleotide polymorphisms (SNPs) in KRAS have been shown to modify susceptibility to multiple tumors, but no specific molecular epidemiology study was reported regarding neuroblastoma.

METHODS

We conducted a four-center case-control study to explore the association between KRAS gene polymorphisms (rs12587 G>T, rs7973450 A>G, rs7312175 G>A) and neuroblastoma susceptibility with 505 Chinese children and 1070 matched controls.

RESULTS

We found that rs7973450 A>G was associated with significantly increased neuroblastoma risk [GG vs. AA: adjusted odds ratio (OR)=4.26, 95% confidence interval (CI)=1.28-14.19, P=0.018; GG vs. AA/AG: adjusted OR=4.27, 95% CI=1.28-14.24, P=0.018]. The stratified analysis further demonstrated that rs7973450 GG genotype carriers had a higher risk to develop neuroblastoma in the subgroups of males, tumor originated from the adrenal gland and clinical stages III+IV.

CONCLUSIONS

Overall, our results suggested that rs7973450 A>G was associated with increased neuroblastoma risk.

Growth, progression and chromosome instability of Neuroblastoma: a new scenario of tumorigenesis?

BACKGROUND

Neuroblastoma is a pediatric cancer with a low survival rate of patients with metastatic stage 4 disease. Tumor aggressiveness and progression have been associated with structural copy number variations (CNVs) that are observed in malignant cells. In contrast, localized Neuroblastomas, which are associated with a low number of structural CNVs but frequent numerical CNVs, are less aggressive, and patients have good outcomes. Finally, whole-genome and whole-exome sequencing of Neuroblastoma tissues have shown few damaging mutations in these tumors.

CONCLUSIONS

In the present report it is proposed that chromosome instability (CIN) plays a major role in Neuroblastoma tumorigenesis and that CIN is already present in the early phases of tumor development. High CIN can promote several types of chromosomal damage including chromothripsis, gene deletion, amplification and rearrangements, which deregulate gene expression. Indeed, gene rearrangements have been reported as a new scenario in the development of Neuroblastoma, which supports the hypothesis that CIN is an early step preliminary to the late catastrophic events leading to tumor development.