HOXA10/IL-7通过激活JAK/STAT信号通路促进铂耐药发生的分子机制研究

The mortality rate of ovarian cancer is the first place in gynecologic malignancies, while platinum resistance is an important cause of treatment failure. Our previous studies have confirmed that the hypomethylation of the promoter region of homeobox gene HOXA10 leads to over expression of HOXA10 gene and promotes the progression of ovarian cancer. The results of pre experiment showed that overexpression of HOXA10 can enhance the resistance of ovarian cancer cells to platinum drugs, the use of PCR ChIP to detect the signal pathway suggesting that JAK/STAT signaling pathway activation and downstream anti apoptotic protein Survivin and bcl-2 expression increased, further detection of JAK/STAT ligand pathway upstream of the highest expression of IL-7, bioinformatics predicted binding sites in the promoter region of IL-7 gene with HOXA10 gene. Therefore, put forward the following hypothesis: HOXA10 gene promoter methylation of the promoter region of low to high expression of HOXA10 gene, and induce IL-7 expression and increased expression of enrichment, activation of JAK/STAT signaling pathway caused by downstream anti-apoptotic protein Survivin and bcl-2, eventually led to the formation of platinum resistant phenotype of ovarian cancer cells. The research group intends to analyze the molecular mechanism of platinum resistance in ovarian cancer from multiple aspects, so as to provide new ideas and potential targets for reversing cisplatin resistance in ovarian cancer.

卵巢癌死亡率居妇科恶性肿瘤首位，而铂耐药是治疗失败的重要原因。我们前期研究证实同源盒基因HOXA10启动子区低甲基化改变导致HOXA10基因的过表达，并促进卵巢癌进展。预实验结果发现HOXA10高表达可促进卵巢癌细胞对铂药物的抵抗，运用信号通路PCR芯片检测提示JAK/STAT信号通路激活，且下游抗凋亡蛋白Survivin和bcl-2表达升高，进一步检测JAK/STAT通路上游配体分子IL-7表达最高，生物信息学预测出IL-7基因启动子区存在与HOXA10基因的结合位点。因此，提出如下假说：HOXA10基因启动子区低甲基化促使HOXA10基因的高表达，进而诱导IL-7富集表达，从而激活JAK/STAT信号通路造成下游抗凋亡蛋白Survivin和bcl-2的表达增加，最终导致卵巢癌细胞铂耐药表型的形成。课题组拟从多个层面分析卵巢癌铂类耐药的分子机制，以期为卵巢癌逆转铂耐药提供新思路和潜在靶标

卵巢癌死亡率居妇科恶性肿瘤首位，而铂耐药是治疗失败的重要原因。我们前期研究证实同源盒基因HOXA10启动子区低甲基化改变导致HOXA10基因的过表达，并促进卵巢癌进展。预实验结果发现HOXA10高表达可促进卵巢癌细胞对铂药物的抵抗。本课题探究了HOXA10在卵巢癌发生发展过程中通过上调CCNE2的表达，其可能的分子机制待后续研究探讨。为临床卵巢癌的发生机制研究提供了新的思路与视野。在研究过程中，课题组发现RNA去甲基化酶ALKBH5在卵巢癌组织中表达水平明显高于正常卵巢组织。同时检测ALKBH5在细胞水平表达情况，结果提示，ALKBH5在卵巢癌细胞株中表达水平低于正常卵巢细胞。为了深入研究肿瘤微环境中巨噬细胞与卵巢癌细胞相互作用的机制，我们采用Transwell小室方法模拟构建了体外共培养体系模型。分别将诱导后的M1和M2型巨噬细胞与卵巢癌细胞共培养，检测发现共培养后的卵巢癌细胞中TLR4表达水平升高，进一步研究分析证实TLR4通过激活NF-κB通路通路，从而促进ALKBH5高表达。采用trascriptome测序、m6A-Seq和m6A MeRIP qRT-PCR方法，分析鉴定发现肿瘤干细胞相关因子NANOG是ALKBH5介导的m6A修饰的靶标之一，NANOG mRNA发生去甲基化后高表达可能最终导致卵巢癌细胞的侵袭性增强，促进卵巢癌的发生。本研究初步验证了ALKBH5作为促癌基因在卵巢癌发生过程中发挥作用。其次通过构建M2型巨噬细胞与卵巢癌细胞共培养体系，发现TLR4富集表达可通过激活NF-κB信号通路，从而促进ALKBH5高表达，并靶向调节NANOG m6A水平，最终导致卵巢癌的发生过程。该研究揭示了表观遗传学中m6A改变在卵巢癌发生中的新作用，有望为卵巢癌发生的靶向治疗提供新思路。