LIN28B polymorphism could modulate the relationship between childhood obesity and age at menarche

The correlation between LIN28B gene potentially functional variants and Wilms tumor susceptibility in Chinese children

BACKGROUND

Wilms tumor (WT) is the most common urologic cancer in children. However, genetic bases underlying WT remain largely unknown. Previous studies indicated that Lin28 homolog B (LIN28B) level is significantly elevated in some WTs. Enforced expression of Lin28b during kidney development could induce WT. Genetic variations in the LIN28B gene may be related to WT susceptibility.

METHOD

In this study, we aimed to assess the association between LIN28B gene polymorphisms and WT susceptibility in Chinese children. Four potentially functional polymorphisms in the LIN28B gene (rs314276 C>A, rs221634 A>T, rs221635 T>C and rs9404590 T>G) were genotyped in 145 cases and 531 cancer-free controls, using Taqman method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations.

RESULTS

Our results showed that the rs314276 CA genotype was associated with a decreased WT risk (CA vs CC: adjusted OR=0.65, 95% CI=0.43-0.98, P=.042). Moreover, we found that carriers of the 1-3 risk genotypes had a significantly increased WT risk when compared to the non-carriers (adjusted OR=1.51, 95% CI=1.03-2.20, P=.035). The association with risk genotypes was more predominant in children 18 month old or younger and in females.

CONCLUSION

In summary, these results indicated that the LIN28B gene rs314276 C>A polymorphism alone and three combined polymorphisms may be able to modify WT susceptibility in Southern Chinese children. Our findings call for further validation in large studies with different ethnicities involved.

Association study of LIN28B in girls with precocious puberty

BACKGROUND

Central precocious puberty (CPP), predominant in girls, is defined by early development of secondary sexual characteristics driven by the early secretion of hypothalamic gonadotropin releasing hormone (GnRH) and subsequent gonadotropin. Recent studies have shown variation in the LIN28B gene is associated with timing of puberty, but only a few have show it to be associated with CPP.

METHODS

This study attempted to investigate the relation between single-nucleotide polymorphisms (SNPs) in LIN28B and girls with precocious puberty. Genotype and alleles frequencies of selected SNPs were compared between 116 girls with CPP and 102 controls.

RESULTS

We found genotype frequencies in rs314276 and rs221634 were significantly correlated with girls with CPP; while the C allele frequency in rs314276 showed the dominant trait. Standard deviation score (SDS) of weight and body mass index (BMI) were higher in CC homozygotes of rs314276 in girls with CPP.

CONCLUSIONS

Our results demonstrate that the genotype of rs314276 in LIN28B is associated with girls with CPP, carrying dominant trait in the C allele.

Potentially functional polymorphisms in the LIN28B gene contribute to neuroblastoma susceptibility in Chinese children

Neuroblastoma is the most commonly diagnosed solid tumour outside the central nervous system in children. However, genetic factors underlying neuroblastoma remain largely unclear. Previous genome-wide association study indicated that lin-28 homolog B (LIN28B) might play an important role in the development of neuroblastoma and also contributed to its poor overall survival. With the purpose to evaluate the association between LIN28B gene polymorphisms and neuroblastoma susceptibility in Southern Chinese population, we conducted this study with 256 neuroblastoma cases and 531 cancer-free controls. Four potentially functional polymorphisms (rs221634 A>T, rs221635 T>C, rs314276 C>A and rs9404590 T>G) were genotyped using Taqman method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the associations between the selected single nucleotide polymorphisms (SNPs) and neuroblastoma susceptibility. We also performed genotype-phenotype association analysis to explore the effects of the selected SNPs on LIN28B gene transcripts. Our results indicated that the rs221634 TT genotype was associated with an increased neuroblastoma risk (TT versus

AA/AT

adjusted OR = 1.50, 95% CI = 1.04-2.17). The association was more pronounced in males, patients with tumour of mediastinum origin, as well as patients in early clinical stages. Moreover, overall analysis and stratified analysis also showed an increased risk of neuroblastoma for carrier of the 2-4 risk genotypes. In summary, these results indicated that the LIN28B rs221634 A>T polymorphism was associated with an increased neuroblastoma risk in Southern Chinese children. These findings need further validation in large studies with different ethnicities involved.

The Cannabinoid Receptor 2 Q63R Variant Modulates the Relationship between Childhood Obesity and Age at Menarche

Background

The ovary is an important site where gene variants modulate pubertal timing. The cannabinoid receptor 2 (CB2) is expressed in the ovary, plays a role in folliculogenesis and ovulation, and can be modulated by estrogens. Obesity is strictly associated with early menarche and is characterized by sex hormone and endocannabinoid derangement.

Aim

In this study, we investigated the role of the CB2 receptor in determining the age at menarche in obese girls.

Methods

We studied a cohort of 240 obese girls (age 11.9±3 years; BMI z-score 2.8±0.8). The age at menarche (if it had already occurred) was recorded at the time of the visit or via phonecall. The CNR2 rs35761398 polymorphism, which leads to the CB2 Q63R variant, was detected by the TaqMan assay.

Results

In total, 105 patients were homozygous for the R63-coding allele (RR), 113 were QR and 22 were QQ. Variance analysis revealed a significantly earlier age of menarche in subjects carrying the Q63 allele, which was also found after adjusting for BMI z-score (11±1.2 vs. 11.6±1.2 years, p = 0.0003). Logistic regression analysis demonstrated that patients homozygous for the Q allele had a 2.2-fold higher risk (odds ratio = 2.2; CI1.1–3.4; p = 0.02) of presenting with an early menarche (age at menarche <12 years).

Conclusion

We demonstrated for the first time the association between the CB2 Q63R functional variant and the age at menarche in a cohort of Italian obese girls.