FSTL1调控PI3K/Akt信号通路在宫颈癌细胞增殖和侵袭中的作用及机制研究

Cervical cancer is one of most common malignant tumors in women.Infection with oncogenic human papillomavirus (HPV) is the major risk factor for invasive cervical cancer . The pathogenesis of cervical cancer is not yet completely understood. Our previous studies found that miR-9 was actived by HPV-16 E6 and involved the proliferation and invasion of cancer cells. Follistatin-related protein 1( FSTL1) was identified as the target of miR-9, which was decreased expression in cervical cancer tissues and inhibited cancer cells invasion.However, the role and molecular mechanism of FSTL1 on development of cervical cancer is not clear. Studies have indicated phosphatidylinositol-3-kinase/proteinkinase B(PI3K/Akt) signal pathway regulates tumor cell proliferation, apoptosis ,invasion and plays an important role in the development of cervical cancer. We hypothesise FSTL1 may act as a tumor suppressor gene on cervical cancer devolpment by regulating PI3K/Akt signal pathway. In this study, we will detect the expression of FSTL1 in cervical cancer tissues and analyze the association between FSTL1 and clinicopathologic feature as well as prognosis. Then we will determinate the function of FSTL1 on cervial cancer cells in vitro and in vivo experiment through the inhibition or overexpression of FSTL1. Furthermore, we will examine the activity of the signaling pathway and expression of downstream target genes. This study aims to clarify the role and regulatory mechanism of FSTL1 gene in cervical cancer proliferation and invasive so as to provide novel therapeutic strategies for cervical cancer.

宫颈癌是常见的妇科恶性肿瘤。它的发生与高危型HPV感染有关，但它的发病机制尚未完全阐明。我们前期研究显示HPV-16 E6通过激活miR-9促进宫颈癌细胞的增殖和迁移， FSTL1为miR-9的靶基因，在宫颈癌组织中低表达，能抑制宫颈癌细胞的迁移，而FSTL1在宫颈癌中的作用机制尚不清楚。已有研究显示PI3K/Akt 信号通路调节肿瘤细胞的增殖、凋亡和侵袭，在宫颈癌发展中起重要作用。我们推测FSTL1可能作为抑癌基因负性调控PI3K/Akt信号通路在宫颈癌发生发展中起作用。本项目将分析FSTL1在宫颈癌组织中的表达及在临床及预后中的判断价值；通过体内体外实验观察FSTL1对宫颈癌细胞生物学功能的影响；通过FSTL1过表达或RNA干扰，检测其对PI3K/Akt信号通路蛋白活性及下游相关蛋白表达的影响。本研究旨在阐明FSTL1在宫颈癌增殖侵袭中的作用及分子调控机制，为宫颈癌的治疗提供新的思路。

宫颈癌是最常见的妇科恶性肿瘤，它的发生与高危型HPV感染有关，然而它的发病机制尚未完全阐明。本研究探讨了卵泡抑素样蛋白1(FSTL1)在宫颈癌发生发展中的作用及机制，结果发现：1.通过运用实时荧光定量PCR（qRT-PCR）及免疫组化技术检测宫颈癌组织中FSTL1mRNA和蛋白的表达及与临床病理的关系，发现FSTL在宫颈癌组织中低表达，且FSTL1的低表达与宫颈癌患者的深度浸润、低分化、肿瘤大、FIGO分期晚有关；2.FSTL1mRNA在高危型HPV阳性组中的表达量低于HPV阴性组；利用小干扰RNA（siRNA）技术，HeLa细胞转染HPV18E6/E7siRNA后，FSTL1mRNA的表达明显上调。提示FSTL1表达与高危型HPV感染相关，HPV18E6、E7癌蛋白基因可以抑制FSTL1mRNA的表达。3.通过在宫颈癌HeLa和SiHa细胞中过表达或抑制FSTL1检测FSTL1对宫颈癌细胞生物学功能及体内稞鼠移植瘤生长的影响，结果显示FSTL1可以抑制宫颈癌细胞HeLa和SiHa的增殖、侵袭、迁移能力和促进凋亡，并能抑制裸鼠皮下移植瘤的生长。4.通过基因芯片、生物信息学分析及Western blotting技术分析FSTL1对下游基因的影响及对PI3K/Akt信号通路蛋白活性及下游相关蛋白表达的影响，显示FSTL1的下游基因富集于转录调控、细胞增殖、凋亡、黏附等生物学过程，FSTL1通过下调IGF-1R/PI3K/AKT/BCL-2/BAX信号通路，抑制宫颈癌细胞增殖和侵袭能力。. 以上研究证实宫颈癌组织中FSTL1的低表达与不良的预后因素及高危型HPV感染有关；FSTL1在宫颈癌发生发展中作为抑癌基因起作用，FSTL1通过下调PI3K/Akt信号通路抑制宫颈癌的增殖、侵袭。本研究为宫颈癌的靶向治疗提供了理论基础。