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.
By this study, a regulatory loop is proposed, wherein, ODC silencing in Y79 cells to result in decreased polyamine levels, thereby, leading to altered protein levels of Lin28b, MMP-2 and MMP-9, which falls in line with earlier studies in neuroblastoma.
We also found that the combination of polymorphisms in CASC15, LIN28B, and LMO1 may be used to predict neuroblastoma risk (AUC=0.63, 95% CI=0.59-0.67).
In vitro experiments using NB cell lines, BE(2)-C, SMS-KCNR, and CHLA90 show that DFMO treatment reduced LIN28B and MYCN protein levels and increased Let-7 miRNA and decreased neurosphere formation.
Taken together, these data show that common variants in HACE1 and LIN28B influence neuroblastoma susceptibility and indicate that both genes likely have a role in disease progression.
In a genome-wide association study, we identified single-nucleotide polymorphisms (SNP) associated with neuroblastoma at the CASC15, BARD1, LMO1, DUSP12, HSD17B12, HACE1, and LIN28B gene loci, but these explain only a small fraction of neuroblastoma heritability.
Several neuroblastoma (NB) susceptibility loci have been identified within LINC00340, BARD1, LMO1, DUSP12, HSD17B12, DDX4, IL31RA, HACE1 and LIN28B by genome-wide association (GWA) studies including European American individuals.
The results also establish that LIN28B overexpression supports neuroblastoma onset and the metastatic potential of malignant cells through let-7a-dependent and let-7a-independent mechanisms.
These findings were fully recapitulated in a mouse model in which LIN28B expression in the sympathetic adrenergic lineage induced development of neuroblastomas marked by low let-7 miRNA levels and high MYCN protein expression.
We set out to determine whether the analysis of TH (tyrosine hydroxylase), PHOX2B (paired-like homeobox 2b), and DCX (doublecortin) transcripts using quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) could be used to detect NB contamination in ovarian tissue.
Furthermore, it has been observed that neuronal differentiation in neuroblastoma is dependent on down-regulation of <i>PHOX2B</i> expression, which confirms that PHOX2B expression may be considered a target in neuroblastoma.
For instance, discoveries in familial NBL have identified genetic aberrations in Phox2b and Alk that predispose to NBL, while advances in epigenetics and MYCN regulation have also offered insight into NBL pathogenesis and future treatment.
We did not find any conclusive association of the polymorphisms or mutations in PHOX2b with the development of NB, although the large confidence intervals neither substantiate nor exclude a role for this gene in the tumor etiology.
Therefore, post-transcriptional down-regulation of the PHOX2B gene takes place in NB cell lines and miRNA-204 participates in such a 3'UTR mediated control.
In the present study, we validated the ability of 14 commonly used real-time RT-PCR markers to detect MRD based on their expression in neuroblastoma TICs, and we developed a novel MRD detection protocol, which scored the samples as MRD-positive when the expression of one of the 11 real-time RT-PCR markers (CHRNA3, CRMP1, DBH, DCX, DDC, GABRB3, GAP43, ISL1, KIF1A, PHOX2B and TH) exceeded the normal range.
We also report a germline PHOX2B mutation in one patient treated for Hirschsprung's disease who subsequently developed a multifocal neuroblastoma in infancy.
In neuroblastoma (NB) patients, minimal residual disease (MRD) can be detected by real-time quantitative PCR (qPCR) using NB-specific target genes, such as PHOX2B and TH.
The PHOX2B gene is implicated in the development of the autonomic nervous system and has been found to be infrequently mutated in sporadic neuroblastoma tumours and in some patients with hereditary neuroblastoma.
Recent studies have shown that 1) PHOX2B is the main disease-causing gene for congenital central hypoventilation syndrome, an autosomal dominant disorder with incomplete penetrance; 2) PHOX2B is the first gene for which germline mutations have been demonstrated to predispose to neuroblastoma; and 3) Hirschsprung disease was associated with an intronic single-nucleotide polymorphism of the PHOX2B gene in a case-control study.
This case highlights the need to consider neuroblastoma in patients with CCHS and the longest PHOX2B PARMs and to individualize treatment based on co-morbidities.
Transient transfections and electrophoretic-mobility-shift assays suggested that PHOX2B is able to bind the cell-specific element in the 5' regulatory region of the TLX2 gene, determining its transactivation in neuroblastoma cells.
Starting from these observations, we have performed in vitro drug screening approaches targeting PHOX2B overexpression as a potential pharmacological means in NB.