Identification of therapeutic sensitivities and pathways driving adrenocortical carcinoma

肾上腺皮质肿瘤相对常见，患病率为1- 10%。大多数是良性的，然而，在极少数情况下，肾上腺皮质癌（ACC）可以发展为侵袭性的，5年预后差。了解驱动ACC进展的途径对于开发更有效的治疗方法和预测个体结局至关重要。下一代测序研究揭示了人类疾病中存在的复发性改变。这些研究已经确定了WNT信号通路中的突变，包括CTNNB 1中的激活突变，是最常见的改变之一。在小鼠中的研究表明，Ctnnb 1中的激活突变可以引起肾上腺皮质中的肿瘤形成，突出了该模型研究肾上腺肿瘤发生的价值。我们已经确定HOXB 9是在肾上腺皮质发育的早期阶段表达的基因，并且在小鼠中通过激活Ctnnb 1突变驱动的肾上腺肿瘤中上调。人类ACC肿瘤也显示HOXB 9表达上调，这与WNT信号转导失调和生存频率降低相关，表明该基因在致癌作用中的作用。在初步研究中，我们已经产生了Hoxb 9在发育和成年肾上腺皮质细胞中表达升高的转基因小鼠。含有这种转基因和激活Ctnnb 1突变的小鼠显示出肿瘤发生的加速，其特征在于细胞增殖和肿瘤重量增加，以及出现具有肿瘤性未分化纺锤形表型的细胞。这些研究表明，HOXB 9可以与WNT信号通路合作，推动肾上腺肿瘤进展。该项目的目的是研究HOXB 9驱动肿瘤进展的细胞和分子机制和途径。使用在体外和体内的方法，我们将确定该基因在肾上腺皮质肿瘤细胞增殖和生存，细胞命运和分化的作用。我们将识别与HOXB 9相关的分子途径，包括其与WNT信号通路的相互作用。该项目的另一个目的是表征肾上腺皮质癌中与WNT信号通路相关的药物敏感性。使用各种ACC模型与失调的WNT信号，我们将研究药物靶向这一途径对细胞存活在体内和体外的影响。使用高通量药物库筛选，我们将确定将增加这些靶向化合物的有效性的组合疗法。在一个互补的方法，我们将使用RNA干扰筛选，以确定在WNT信号通路的关键节点，抑制时实现ACC. The最终目标的研究提出的治疗反应是确定新的途径和药物敏感性在肾上腺皮质癌的发生，将提供重要的信息，将有助于发展的临床治疗，以治疗这种罕见的侵略性疾病。

Tumours of the adrenal cortex are relatively common with a prevalence of 1-10%. Most of these are benign, however, in rare case adrenocortical carcinoma (ACC) can develop which is aggressive and has a poor 5 year prognosis. Understanding pathways that drive ACC progression is essential to the development of more effective treatments and for the prediction of individual outcomes. Next generation sequencing studies have revealed recurrent alterations present in human disease. These studies have identified mutations in the WNT signalling pathway, including activating mutations in CTNNB1, to be one of the most frequent alterations. Studies in mice have shown that activating mutations in Ctnnb1 can give rise to tumour formation in the adrenal cortex, highlighting the value of this model to study adrenal tumourigenesis. We have identified HOXB9 as a gene expressed in the early stages of adrenal cortex development and upregulated in adrenal tumours driven by activating Ctnnb1 mutations in mice. Human ACC tumours also show upregulation of HOXB9 expression that correlates with WNT signalling dysregulation and decreased survival frequency suggesting a role for this gene in carcinogenesis. In preliminary studies, we have generated transgenic mice with elevated Hoxb9 expression in developing and adult adrenal cortical cells. Mice that contain this transgene and an activating Ctnnb1 mutation showed acceleration of tumourigenesis characterised by increased cell proliferation and tumour weight and in the appearance of cells with a neoplastic undifferentiated spindle shaped phenotype. These studies indicate that HOXB9 can cooperate with the WNT signalling pathway to drive adrenal tumour progression. The aim of this project is to investigate the cellular and molecular mechanisms and pathways by which HOXB9 drives tumour progression. Using in vitro and in vivo approaches we will determine the role of this gene in adrenocortical tumour cell proliferation and survival, cell fate and differentiation. We will identify the molecular pathways associated with HOXB9, including its interaction with the WNT signalling pathway.An additional aim of this project is to characterise the drug sensitivities associated with the WNT signalling pathway in adrenocortical carcinoma. Using various ACC models with dysregulated WNT signalling we will investigate the effect of drugs targeting this pathway on cell survival in vivo and in vitro. Using high throughput drug library screens we will identify combinations therapies that will increase the effectiveness of these targeted compounds. In a complementary approach, we will use RNA interference screens to identify the key nodal points in the WNT signalling pathway that when inhibited achieve a therapeutic response in ACC. The ultimate goal of the studies proposed is to identify novel pathways and drug sensitivities in adrenocortical carcinogenesis that will provide important information that will aid in the development of clinical therapies to treat this rare and aggressive disease.