KRAS/ERK/RKIP通路在胰腺癌化疗抵抗中的作用及载砷纳米微粒的靶向调控

Our previous studies have found that diminished or lost expression of Raf kinase inhibitor protein（RKIP）was correlated strongly with pancreatic cancer metastasis, reducing chemotherapy sensitivity, and poor clinical prognosis. And RKIP was negatively correlated with KRAS expression. Furthermore, KRAS negatively regulates expressions of RKIP and its downstream tumor metastasis and cell apoptosis associate factors through ERK pathway, which suggest that KRAS/ERK/RKIP pathway exists in pancreatic cancer. In addition, arsenic trioxide (arsenic trioxide, ATO) is correlated with this pathway. Our recent research has demonstrated that ATO downregulating KRAS to induce cell apoptosis and upregulating RKIP to enhance gemcitabine (gemcitabine, Gem) cytotoxic effect. Therefore, this study was proposed to detect the important biological role of KRAS/RKIP/ERK pathway in pancreatic cancer metastasis and chemotherapy resistance, verify the mechanism and function of ATO regulating KRAS/ERK/RKIP pathway to reverse chemotherapy resistance, and construct targeted nanoparticles loading ATO and Gem to observe the synergy treatment effect on pancreatic cancer. This project illuminates that KRAS/RKIP/ERK is the key downstream pathway of KRAS to regulate pancreatic cancer metastasis and chemotherapy resistance, which can be used as the target for pancreatic cancer treatment, and ATO can be applied as sensitization agent in pancreatic cancer chemotherapy.

我们前期研究发现胰腺癌Raf激酶抑制蛋白（RKIP）表达下调或缺失促进其转移和化疗抵抗，临床预后差。且RKIP与KRAS表达呈负性相关；进一步实验显示KRAS经ERK负性调控RKIP及其下游肿瘤转移和凋亡相关通路蛋白，提示存在KRAS/ERK/RKIP通路调控胰腺癌转移和化疗抵抗。此外，三氧化二砷（arsenic trioxide, ATO）与该通路密切相关，可通过下调KRAS诱导细胞凋亡、上调RKIP增强吉西他滨（gemcitabine, Gem）细胞毒作用。本课题拟验证KRAS/ERK/RKIP通路在胰腺癌转移和化疗抵抗中作用，明确ATO调控KRAS/ERK/RKIP逆转化疗抵抗作用机制，并探讨靶向纳米微粒共载ATO和Gem协同抗胰腺癌效应。本项目阐明KRAS/ERK/RKIP是KRAS调控胰腺癌转移和化疗抵抗关键通路，可作为胰腺癌治疗新靶点，为ATO作为胰腺癌化疗增敏剂奠定理论基础。

我们前期研究发现胰腺癌Raf激酶抑制蛋白（RKIP）表达下调或缺失促进其转移和化疗抵抗，临床预后差。且RKIP与KRAS表达呈负性相关；进一步实验显示KRAS经ERK负性调控RKIP及其下游肿瘤转移和凋亡相关通路蛋白，提示存在KRAS/ERK/RKIP通路调控胰腺癌转移和吉西他滨（gemcitabine, GEM）化疗抵抗。此外，三氧化二砷（arsenic trioxide, ATO）与增强GEM细胞毒作用有关。本课题拟验证KRAS/ERK/RKIP通路在胰腺癌转移和化疗抵抗中作用，明确ATO可增强GEM化疗敏感性及逆转化疗抵抗作用机制，并探讨靶向纳米微粒共载ATO和GEM协同抗胰腺癌效应。. 本项目系统阐明KRAS经ERK负性调控RKIP从而调控胰腺癌细胞生长、转移及GEM化疗耐药。KRAS/ERK/RKIP是KRAS调控胰腺癌转移和化疗抵抗关键通路，可作为胰腺癌治疗新靶点。此外，本研究同时发现并阐明胰腺癌存在TIMP1/PI3K/AKT/mTOR通路与GEM化疗耐药相关，ATO可通过抑制TIMP1/PI3K/AKT/mTOR通路增强GEM化疗敏感性及逆转化疗耐药。体内外实验证实：ATO增强GEM对胰腺癌细胞杀伤作用，与GEM协同抑制胰腺癌肿瘤生长和转移。ATO为胰腺癌吉西他滨化疗提供新的增敏剂，实现“老药新用”。进一步，本课题构建CD44v6、MUC4、CEACAM6三种单链抗体修饰的IONPs（IONPs-PEG-MCC triple scAbs）纳米复合物，其显著降低MR成像T2序列的信号强度并靶向聚集在肿瘤区域从而实现MR肿瘤成像，体内外实验模型证实其具有抗胰腺癌效应，为包载GEM及联合包载ATO纳米微粒提供一种新的靶向纳米材料。