输卵管来源卵巢低级别浆液性癌动物模型建立及HOXA5相关分子通路在其发生发展中的作用和机制研究

Ovarian cancer is highly heterogeneous malignancy. There has been no significant progress in the diagnosis and treatment of ovarian cancer in the last 50 years. This dismal state of affairs is mainly due to the fact that the origin and pathogenesis of ovarian cancer are unclear. Therefore, understanding the origin of ovarian cancer is the basis for further research. At present, more and more evidence suggests that ovarian high-grade serous carcinomas mainly originate from fallopian tube. But the origin of ovarian low-grade serous carcinoma is still unclear. Based on our previous study of immunology and molecular biology, we will establish ovarian low-grade serous carcinoma from fallopian tube in mice model to identify the origin of it. Meanwhile, we analyzed the differential expression of mRNA between ovarian low-grade serous carcinoma and fallopian tube and showed that HOXA5 was significantly different between the two. Then, we will determine the functional effect of HOXA5 on ovarian low-grade serous carcinoma in vitro and in vivo. Subsequently, ChIP-Seq, luciferase assay and bioinformatics analysis will be used to identify the downstream targets of HOXA5. Finally, we will further explore the mechanism of HOXA5 and its associated molecular pathway in ovarian low-grade serous carcinoma. This research will confirm the origin of ovarian low-grade serous carcinoma and will help to reveal the development mechanism of it, providing new strategies for early diagnosis and targeted treatment of ovarian low-grade serous carcinoma.

卵巢癌为高度异质性恶性肿瘤，近半个世纪卵巢癌诊治未取得明显进展，主要原因在于卵巢癌起源不明与发病机制不清，明确卵巢癌起源是进一步研究的基础。目前越来越多的证据表明卵巢高级别浆液性癌起源于输卵管，而卵巢低级别浆液性癌起源仍未明。本课题拟在前期免疫学和分子学研究的基础上建立输卵管来源卵巢低级别浆液性癌动物模型，明确其起源。同时，对卵巢低级别浆液性癌和输卵管上皮mRNA表达谱进行差异表达分析，进一步验证显示HOXA5在二者间表达具有明显差异，随后拟利用体外和体内实验明确HOXA5在卵巢低级别浆液性癌中的生物学功能；利用ChIP-Seq、luciferase及生物信息学等方法筛选和鉴定HOXA5下游关键分子；并进一步分析HOXA5及下游关键分子通路在卵巢低级别浆液性癌中的作用机制。本研究将明确卵巢低级别浆液性癌起源，有助于揭示其发生发展机制，以期为本病早期诊断和靶向治疗提供新的策略。

卵巢癌为高度异质性恶性肿瘤，病死率位居妇科恶行肿瘤之首。近半个世纪卵巢癌诊治未取得明显进展，主要原因在于卵巢癌起源不明与发病机制不清。绝大多数卵巢癌为浆液性癌，既往研究表明高级别浆液性癌（HGSC）主要起源于浆液性输卵管上皮内癌，而低级别浆液性癌（LGSC）起源仍存在争议。本课题组前期研究显示LGSC可能主要来源于正常输卵管上皮，经过包涵体囊肿-良性浆液性囊腺瘤-交界性浆液性肿瘤-低级别浆液性癌这一渐进性过程发展形成。本课题基于前期研究基础进一步探索了LGSC发生发展相关分子机制。对卵巢低级别浆液性癌和输卵管上皮mRNA表达谱进行差异表达分析，明确了HOXA5在二者间表达具有明显差异，通过免疫组化染色显示HOXA5在LGSC中明显低表达，并与患者不良预后相关。体内外功能实验证实干扰HOXA5表达明显促进肿瘤的增殖、克隆形成、细胞周期进展，抑制细胞凋亡，HOXA5过表达明显抑制肿瘤的增殖、克隆形成、细胞周期进展，促进细胞凋亡，表明HOXA5在LGSC中发挥显著的抑癌作用。在LGSC细胞系HOC7和PEO14中给予全反式维甲酸（ATRA）明显促进HOXA5表达，抑制细胞增殖、克隆形成、细胞周期，促进细胞凋亡，在LGSC的PDX模型中给予ATRA明显抑制小鼠体内肿瘤的生长。此外，RNA-seq结合ChIP-seq联合分析显示在LGSC中HOXA5可能转录调控下游靶基因CDKN1C。qRT-PCR和Western Blot进一步验证表明在PEO14细胞中HOXA5可影响CDKN1C的表达，且CDKN1C在LGSC中的表达明显低于输卵管上皮，提示HOXA5可能通过调控CDKN1C表达发挥抑癌作用。该研究为LGSC的治疗提供新的靶点，全反式维甲酸有望成为LGSC有效的维持治疗药物，实现LGSC的慢病管理。