Prognostic value of the TGFß1 rs4803455 single nucleotide polymorphism in small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) is one of the greatest therapeutic challenges of oncology. Potential associations between single nucleotide polymorphisms in heat shock protein ß1 (HSPB1) and transforming growth factor ß1 (TGFß1) and survival have been investigated. METHODS: A prospective multicenter study of 94 patients with SCLC treated between 2013 and 2016 was conducted. Clinical, tumour-related, therapeutic, and genetic (9 SNPs of TGFß1 gene and 5 of HSPB1 gene) variables were analyzed. RESULTS: The cohort included 77 men and 17 women with a median age of 61 years. Eighty percent presented with limited stage at diagnosis and received thoracic radiation with a median dose of 45 Gy (twice-daily radiation in 42%). Forty-seven percent received concurrent platinum-based chemotherapy and 57% received prophylactic cranial irradiation (PCI). Overall survival (OS) was 34% at 2 years and 16% at 3 years. In multivariate analysis, the rs4803455:CA genotype of the TGFß1 gene showed a statistically significant association with lower disease-free survival (DFS; hazard ratio [HR] 3.13; confidence interval [CI] 1.19-8.17; p = 0.020) and higher local recurrence (HR 3.80; CI 1.37-10.5; p = 0.048), and a marginal association with lower OS (HR 1.94; CI 0.98-3.83; p = 0.057). A combined analysis showed that patients receiving PCI and carrying the rs4803455:CA genotype had statistically significant lower OS (p < 0.001) and DFS (p < 0.001) than patients receiving PCI and carrying the rs4803455:AA genotype. CONCLUSIONS: Genetic analysis showed the CA genotype of TGFß1 SNP rs4803455 was associated with worse prognosis in patients with SCLC and could be considered as a potential biomarker.

Association of single nucleotide polymorphisms at HSPB1 rs7459185 and TGFB1 rs11466353 with radiation esophagitis in lung cancer.

BACKGROUND AND PURPOSE: Radiochemotherapy (RCT) success in lung cancer (LC) can be limited due to the onset of adverse effects in the adjacent normal tissue such as radiation-induced esophageal toxicity (RIET). Therefore, specific biomarkers to customize the RCT dose administration and esophageal toxicity prediction are necessary to improve treatment effectiveness. MATERIALS AND METHODS: 247 LC patients prospectively recruited between 2012 and 2016 from 3 institutions were genotyped for 7 SNPs along TGFB1 and HSPB1 genes seeking an association with RIET risk development. Kaplan-Meier cumulative probability and Cox proportional hazards analyses were used to evaluate the effect of TGFB1 and HSPB1 genotypes on such risk. RESULTS: Multivariate analyses showed that patients carrying the HSPB1 rs7459185 CC genotype were associated with a significantly higher risk of acute grade 3 RIET than those carrying the GG/GC genotypes (HR = 17.73; 95% CI = 2.896-108.49; p = 0.002). LC patients who received higher (>median) volume of esophagus exposed to 30 Gy and harboring the rs7459185 GG/GC genotypes showed a significantly lower RIET incidence (p < 0.001). Additionally, LC patients carrying the TGFB1 rs11466353 GG genotype were found to be associated with a lower risk of late grade 2 RIET compared with those with the TT/TG genotypes (HR = 0.29; 95% CI = 0.103-0.830; p = 0.021). Patients receiving a high (>60 Gy) radiation dose who presented the rs11466353 GG genotype had a significantly lower RIET incidence (p = 0.025). CONCLUSION: The presence of different rs7459185/rs11466353 genotypes in LC patients associated with RIET risk and may be useful biomarkers along with other risk factors for guiding therapy intensity in an individualized therapy.

Identification of different mechanisms leading to PAX6 down-regulation as potential events contributing to the onset of Hirschsprung disease.

Hirschsprung disease (HSCR) is attributed to a failure of neural crest derived cells to migrate, proliferate, differentiate or survive in the bowel wall during embryonic Enteric Nervous System (ENS) development. This process requires a wide and complex variety of molecules and signaling pathways which are activated by transcription factors. In an effort to better understand the etiology of HSCR, we have designed a study to identify new transcription factors participating in different stages of the colonization process. A differential expression study has been performed on a set of transcription factors using Neurosphere-like bodies from both HSCR and control patients. Differential expression levels were found for CDYL, MEIS1, STAT3 and PAX6. A significantly lower expression level for PAX6 in HSCR patients, would suit with the finding of an over-representation of the larger tandem (AC)m(AG)n repeats within the PAX6 promoter in HSCR patients, with the subsequent loss of protein P300 binding. Alternatively, PAX6 is a target for DNMT3B-dependant methylation, a process already proposed as a mechanism with a role in HSCR. Such decrease in PAX6 expression may influence in the proper function of signaling pathways involved in ENS with the confluence of additional genetic factors to the manifestation of HSCR phenotype.

Involvement of DNMT3B in the pathogenesis of Hirschsprung disease and its possible role as a regulator of neurogenesis in the human enteric nervous system.

PURPOSE: Hirschsprung disease (OMIM 142623) is a neurocristopathy attributed to a failure of cell proliferation or migration and/or failure of the enteric precursors along the gut to differentiate during embryonic development. Although some genes involved in this pathology are well characterized, many aspects remain poorly understood. In this study, we aimed to identify novel genes implicated in the pathogenesis of Hirschsprung disease. METHODS: We compared the expression patterns of genes involved in human stem cell pluripotency between enteric precursors from controls and Hirschsprung disease patients. We further evaluated the role of DNMT3B in the context of Hirschsprung disease by inmunocytochemistry, global DNA methylation assays, and mutational screening. RESULTS: Seven differentially expressed genes were identified. We focused on DNMT3B, which encodes a DNA methyltransferase that performs de novo DNA methylation during embryonic development. DNMT3B mutational analysis in our Hirschsprung disease series revealed the presence of potentially pathogenic mutations (p.Gly25Arg, p.Arg190Cys, and p.Gly198Trp). CONCLUSION: DNMT3B may be regulating enteric nervous system development through DNA methylation in the neural crest cells, suggesting that aberrant methylation patterns could have a relevant role in Hirschsprung disease. Moreover, the synergistic effect of mutations in both DNMT3B and other Hirschsprung disease-related genes may be contributing to a more severe phenotype in our Hirschsprung disease patients.

Comprehensive analysis of NRG1 common and rare variants in Hirschsprung patients.

Hirschsprung disease (HSCR, OMIM 142623) is a developmental disorder characterized by the absence of ganglion cells along variable lengths of the distal gastrointestinal tract, which results in tonic contraction of the aganglionic gut segment and functional intestinal obstruction. The RET proto-oncogene is the major gene for HSCR with differential contributions of its rare and common, coding and noncoding mutations to the multifactorial nature of this pathology. Many other genes have been described to be associated with the pathology, as NRG1 gene (8p12), encoding neuregulin 1, which is implicated in the development of the enteric nervous system (ENS), and seems to contribute by both common and rare variants. Here we present the results of a comprehensive analysis of the NRG1 gene in the context of the disease in a series of 207 Spanish HSCR patients, by both mutational screening of its coding sequence and evaluation of 3 common tag SNPs as low penetrance susceptibility factors, finding some potentially damaging variants which we have functionally characterized. All of them were found to be associated with a significant reduction of the normal NRG1 protein levels. The fact that those mutations analyzed alter NRG1 protein would suggest that they would be related with HSCR disease not only in Chinese but also in a Caucasian population, which reinforces the implication of NRG1 gene in this pathology.