Pituitary tumor transforming gene-1 haplotypes and risk of pituitary adenoma: a case-control study

Association of PTTG1 polymorphism rs1895320, rs2910200 and rs6882742 with non-functioning pituitary adenomas in Chinese Han population: a case-control study

Due to absence of clinical manifestations of hormonal hyper secretion, the treatment of Nonfunctioning pituitary adenoma (NFPA) was always delayed. PTTG1 was reported to be overexpressed in most of pituitary tumors, however, the polymorphism of PTTG1 rs1895320, rs2910200 and rs6882742 with NFPA were still not fully elucidated in NFPA. Thus, a hospital based case control study which included 79 patients and 142 healthy control participants were conducted. DNA was extracted from peripheral blood samples and genotyped by Mass Array methods. In addition, a meta-analysis of rs2910200 was also employed to further testify the conclusion. Significant difference were observed between patients and healthy controls under rs2910200 locus between allelic genotype (p = 0.0219). However, no other significant difference was observed in rs1895329 and rs6882742. In addition, a logistic regression analysis showed that the dominant model of rs2910200 were closely correlated with the NFPA susceptibility (OR = 1.951, 95% CI:1.075-3.542, p = 0.028). While no significant difference was observed in the rs1895320 and rs6882742 under dominant model, recessive model and additive model The meta-analysis results showed that the dominant model and heterozygote model can significantly increase the risk of PA (p = 0.007, OR = 1.57, 95% CI:1.14-2.18; p = 0.009, OR = 1.57, 95% CI:1.12-2.19). Whereas no significant difference were observed under the homozygous model and recessive model. In conclusion, the polymorphism of PTTG1 rs2910200 dominant model and T allelic might increase the risk of NFPA.

Are pre-miR-146a and PTTG1 associated with papillary thyroid cancer?

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy, with a steadily increasing incidence in the last few decades worldwide. The predisposition to developing this carcinoma by the heterozygous state of rs2910164 within the precursor of the miR-146a has been reported, but recently not confirmed. Interestingly, on the same chromosome, almost 50 kb separate the pre-miR-146a from the pituitary tumor-transforming gene 1 (PTTG1), a proto-oncogene involved in several tumors, including thyroid cancers. In this study, we analyzed, using a case-control design, the genetic association between PTC and the genomic region encompassing pre-miR-146a rs2910164 and PTTG1 rs1862391 and rs2910202. We enrolled 307 affected patients and 206 healthy controls. The possible presence of thyroid nodules in controls was excluded by ultrasonography. All the cases were submitted to single-nucleotide polymorphism (SNP) genotyping of pre-miR-146a and PTTG1, and risk association analyses were carried out. The genotypic and allelic frequencies of pre-miR-146a rs2910164 were not statistically different in the patients and controls, and this SNP was not in linkage disequilibrium with the investigated PTTG1 SNPs. Consistently, meta-analyses, the first including all the affected cases published to date, did not confirm the previously reported association of the heterozygous CG genotype with PTC. The PTTG1 SNPs exhibited the same allelic frequency in the patients and controls and were not associated with the disease. In conclusion, in a well-selected Italian population, neither pre-miR-146a rs2910164 nor PTTG1 rs1862391 and rs2910202 were found to be associated with the risk of developing PTC.

Pituitary adenoma pathogenesis: an update

PURPOSE OF REVIEW

To describe the recent efforts to understand the molecular and genetic mechanisms involved in the tumorigenesis of pituitary adenomas.

RECENT FINDINGS

There is rapidly accumulating evidence for the roles of molecular abnormalities in pituitary adenoma tumorigenesis, including dysregulation of the cell cycle, signal transduction pathways, oncogenes and tumor suppressor genes. MicroRNAs have been identified as important participants in gene regulation and may have a role in therapy. Stem cells have also provided novel concepts for tumorigenesis and potentially treatment.

SUMMARY

Pituitary adenomas are relatively common neoplasms, whose pathogenesis is still poorly understood. Although considered by many as benign monoclonal proliferations, their clinical spectrum is diverse including hormone hypersecretion, and various degrees of invasiveness, suggesting multiple steps and mechanisms. This review summarizes recent development in the molecular tumorigenesis of pituitary adenomas emphasizing the dysregulation of the cell cycle components, tumor suppressor genes, oncogenes, stem cells and microRNAs.