The effect of AIP mutations on the apoptotic RET pathway in pituitary adenomas

AIP突变对垂体腺瘤细胞凋亡RET通路的影响

• 批准号: MR/M018539/1
• 负责人: Marta Korbonits
• 金额: $ 52万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FM018539%2F1
• 关键词: effect; AIP; mutations; apoptotic; RET

Pituitary adenomas are benign tumours of the pituitary, an endocrine gland located at the base of the brain. If an adenoma develops here it can cause problems either because of its size, where it can damage the surrounding crucial structures (e.g. optic nerve), or due to excess hormone release. Recently mutations in a gene called AIP have been identified which predisposes to childhood or young-adult onset adenomas often leading to a devastating condition called gigantism. Despite the AIP protein being present in every cell of the body, a unique feature of patients with germline AIP mutations is that they only develop pituitary adenoma, most commonly from the growth hormone (GH)-secreting cells of the pituitary gland. The overall aim of our study is to identify the mechanism by which AIP-related tumours develop. Based on our preliminary data this proposal aims to clarify the role of the RET protein, an important regulator of cell growth and death, and its pathway members in the mechanism of the AIP-related tumorigenesis. Over the last few years it has been revealed that stem cells constantly provide new differentiated endocrine cells throughout a person's life and there is a control mechanism, apoptosis, removing cells to maintain the number of cells in the normal pituitary gland. In the pituitary gland RET is predominantly expressed in the growth hormone cells and contributes to this apoptotic process. The apoptotic RET pathway, responsible for controlled cell death, provides the first physiological pathway contributing to pituitary cell turnover in GH cells. This project will explore the possibility that disruption of the apoptotic RET pathway contributes to AIP-related tumorigenesis in humans. We will use a somatotroph cell line to study these pathways as well as cells from rat and mouse pituitary glands as they resemble physiological growth hormone-secreting cells better than the cell line. We will transfect the cells with mutant AIP or we will knock down the cell's own AIP (therefore making the cell deficient in AIP) and will study resulting changes in RET pathway members such RET, Caspase 3 activity, PKCdelta, CREB, JNK, p53 and Pit-1 proteins. We will also explore if AIP, as a partner to the heat-shock protein 90, plays a 'chaperone' role in RET biogenesis, trafficking or degradation. In addition, we will study pituitary tumour samples removed during surgery from patients with AIP mutations and compare data to human adenoma samples without AIP mutation. We have created a mouse model which does not express AIP in the pituitary gland and we will use this to study the development of the pituitary gland both before and after birth including at puberty, when humans with AIP mutations often develop adenomas. In the final part of the project we will microinject virus particles containing mutant or wild type, naturally occurring AIP (wt-AIP), into the pituitary gland of newborn and pubescent animals and will study their impact on pituitary gland and body growth.We hope that identifying the role of AIP in the RET-regulated proliferation and cell death pathways will help to identify new therapeutic targets for patients.

垂体腺瘤是垂体的良性肿瘤，垂体是位于大脑底部的内分泌腺。如果腺瘤在这里生长，它可能会引起问题，要么是因为它的大小，它会损害周围的关键结构（如视神经），要么是因为过量的激素释放。最近，一种名为AIP的基因突变被发现，这种基因易导致儿童或青年发病的腺瘤，通常会导致一种叫做巨人症的毁灭性疾病。尽管AIP蛋白存在于身体的每个细胞中，但种系AIP突变患者的一个独特特征是他们只发展为垂体腺瘤，最常见的是垂体分泌生长激素（GH）的细胞。我们研究的总体目的是确定aip相关肿瘤发展的机制。基于我们的初步数据，本研究旨在阐明作为细胞生长和死亡重要调控因子的RET蛋白及其通路成员在aip相关肿瘤发生机制中的作用。在过去的几年里，人们发现干细胞在人的一生中不断提供新的分化的内分泌细胞，并且存在一种控制机制，即凋亡，清除细胞以维持正常垂体细胞的数量。在垂体中，RET主要在生长激素细胞中表达，并参与了这一凋亡过程。凋亡的RET通路负责控制细胞死亡，是促进GH细胞中垂体细胞更新的第一个生理通路。本项目将探索细胞凋亡RET通路的破坏是否有助于人类aip相关肿瘤的发生。我们将使用生长营养细胞系来研究这些途径以及来自大鼠和小鼠垂体的细胞，因为它们比细胞系更像生理生长激素分泌细胞。我们将用突变的AIP转染细胞，或者我们将敲除细胞自身的AIP（因此使细胞缺乏AIP），并将研究RET通路成员的变化，如RET、Caspase 3活性、PKCdelta、CREB、JNK、p53和Pit-1蛋白。我们还将探讨AIP作为热休克蛋白90的伙伴，是否在RET的生物发生、运输或降解中起“伴侣”作用。此外，我们将研究手术中切除的AIP突变患者的垂体肿瘤样本，并将数据与未发生AIP突变的人腺瘤样本进行比较。我们已经创建了一个在脑垂体中不表达AIP的小鼠模型，我们将用它来研究脑垂体在出生前后的发育，包括青春期，当AIP突变的人经常发生腺瘤时。在项目的最后一部分，我们将把含有突变型或野生型自然发生的AIP （wt-AIP）的病毒颗粒微注射到新生和短毛动物的脑垂体中，研究它们对脑垂体和身体生长的影响。我们希望确定AIP在ret调控的增殖和细胞死亡途径中的作用将有助于为患者确定新的治疗靶点。

项目成果

Genetics of Acromegaly and Gigantism.

• DOI: 10.3390/jcm10071377
• 发表时间: 2021-03-29
• 期刊: Journal of clinical medicine
• 影响因子: 3.9
• 作者: Bogusławska A;Korbonits M
• 通讯作者: Korbonits M

Posterior pituitary tumours: patient outcomes and determinants of disease recurrence or persistence.

• DOI: 10.1530/ec-20-0621
• 发表时间: 2021-04
• 期刊: Endocrine connections
• 影响因子: 2.9
• 作者: Das L;Vaiphei K;Rai A;Ahuja CK;Singh P;Mohapatra I;Chhabra R;Bhansali A;Radotra BD;Grossman AB;Korbonits M;Dutta P
• 通讯作者: Dutta P

Temozolomide Nonresponsiveness in Aggressive Prolactinomas and Carcinomas: Management and Outcomes.

• DOI: 10.1210/jendso/bvab190
• 发表时间: 2022-02-01
• 期刊: Journal of the Endocrine Society
• 影响因子: 4.1
• 作者: Das L;Rai A;Salunke P;Ahuja CK;Sood A;Radotra BD;Sood R;Korbonits M;Dutta P
• 通讯作者: Dutta P

Risk category system to identify pituitary adenoma patients with AIP mutations.

• DOI: 10.1136/jmedgenet-2017-104957
• 发表时间: 2018-04
• 期刊: Journal of medical genetics
• 影响因子: 4
• 作者: Caimari F;Hernández-Ramírez LC;Dang MN;Gabrovska P;Iacovazzo D;Stals K;Ellard S;Korbonits M;International FIPA consortium
• 通讯作者: International FIPA consortium

In vivo bioassay to test the pathogenicity of missense human AIP variants.

• DOI: 10.1136/jmedgenet-2017-105191
• 发表时间: 2018-08
• 期刊: Journal of medical genetics
• 影响因子: 4
• 作者: Aflorei ED;Klapholz B;Chen C;Radian S;Dragu AN;Moderau N;Prodromou C;Ribeiro PS;Stanewsky R;Korbonits M
• 通讯作者: Korbonits M