D-松醇缓解胰岛素抵抗降低诱发癌症风险的作用机制研究

According to the epidemiology data, diabetes has a closely association with some highly occurred cancers, and the diabetes patients have a higher risk to have cancer than the normal people. It is possibly because of the excessive accumulation of insulin-like growth factor-1 receptor (IGF-1R). D-pinitol is a kind of natural compound with many bioactivity functions. In our previously study, we found that D-pinitol could relieve insulin resistance and decrease the insulin level in serum, finally reduce the blood glucose level. However, whether D-pinitol can decrease the tumorigenesis risk by relieving insulin resistance and through which molecular mechanism is still unclear. In this project, we will firstly prove whether D-pinitol could prevent insulin resistance cells phenotype to change worse. And then using LC-MS, Co-IP and shRNA transfection techniques to reveal the relationship between D-pinitol and IGF-1R. Finally, type 2 diabetes mellitus (T2DM) animal model will be performed to testify whether D-pinitol could lower the tumorigenesis risk in T2DM rats. The purpose of this project is to demonstrate whether D-pinitol can restraint cells phenotype become worse in high insulin concentration surroundings, and try to investigate its molecular mechanism, in order to give a basic support to the conjecture that D-pinitol can prevent diabetes patients to be attacked by cancer.

据流行病学数据统计，糖尿病患者比正常人更具有患癌风险，其诱发机制可能与胰岛素样生长因子-1受体（IGF-1R）的过量积累有关。D-松醇是一种具有多种生物活性功能的天然物质，在前期的研究中我们发现D-松醇可以缓解机体胰岛素抵抗，降低血清胰岛素含量，从而起到改善糖尿病病症的作用。然而，D-松醇能否通过缓解胰岛素抵抗，降低细胞的恶性转化以及其作用机制如何还尚不清楚。本课题拟首先在细胞水平验证D-松醇能否降低胰岛素抵抗细胞的恶性转化，并通过质谱分析，免疫共沉淀，shRNA技术进一步明确高浓度胰岛素环境下，D-松醇与IGF-1R的关系，最后，通过糖尿病动物模型在体内观察D-松醇能否降低糖尿病动物的患癌风险及其作用机制。本课题旨在明确高浓度胰岛素环境下，D-松醇能否降低胰岛素抵抗细胞的恶性转化，并阐明其在细胞发生恶性转化中的作用机制，为D-松醇在降低临床糖尿病患者患癌风险的应用提供理论依据。

据流行病学数据统计，糖尿病患者比正常人具有更高的患癌风险，其诱发机制可能与机体长时间处于高血糖环境有关。D-松醇是一种具有多种生物活性功能的天然化合物，在早期的研究中我们发现其可以缓解机体胰岛素抵抗、降低空腹血糖水平（FBS）和血清胰岛素含量（FINS），从而起到改善糖尿病病症的作用。因此本项目以此为立项依据，考察D-松醇是否能够降低胰岛素抵抗患者患癌症的风险。本研究以患肝癌的风险为研究目标，在体外实验中建立了肝癌细胞胰岛素抵抗细胞模型，发现给予200ug/mL和400ug/mL的D-松醇可以有效的抑制多种肝癌细胞的增殖、克隆形成和迁移能力，缓解了肝癌细胞的表型恶化。在体内实验中，选用ZDF Ⅱ型糖尿病疾病鼠作为研究对象，建造胰岛素抵抗模型。在给予一段时间D-松醇干预后，200mg/kg剂量组大鼠糖尿病病症及生理生化指标得以显著性改善。Elisa试剂盒检测大鼠血清中炎症因子发现D-松醇可以有效降低血清中IL-6和TNF-α的表达，同时升高IGF-1的表达。在胰岛素抵抗大鼠肝脏组织转录组测序数据分析结果中，发现多种肝癌相关基因出现异常表达。RT-PCR验证结果表明D-松醇可以有效的缓解由胰岛素抵抗引发的炎症因子IL-6、TNF-α异常表达；以及改善肝癌相关因子Foxp1、Asph、Hipk2和Rassf6的异常表达。说明了D-松醇具有降低胰岛素抵抗大鼠患肝癌风险的作用，其机理可能是通过负调节胰岛素抵抗大鼠体内过高的炎症相关因子的表达水平，从而起到诱发癌症风险的效果。本研究为后续深入研究奠定了理论基础，为以D-松醇治疗由胰岛素抵抗引发的炎症反应的药物开发提供了理论依据。