FOXC1通过NF-κB信号通路介导HPV阳性宫颈癌细胞恶性表型的机制研究

Mechanistic role of FOXC1 in promoting malignant phenotypes of HPV16-positive cervical cancer via NF-κB signaling pathway

  • 摘要: 背景 人乳头瘤病毒16型(HPV16)E6致癌蛋白是宫颈癌发生的关键因子,然而其介导细胞增殖与凋亡的发生机 制仍有待阐明。目的 本研究旨在探讨HPV16 E6是否通过FOXC1激活NF-κB通路,并阐明FOXC1在HPV阳性宫颈癌细 胞增殖与凋亡中的调控机制。方法 通过Western Blot检测宫颈癌组织及正常宫颈组织中FOXC1、Ki-67和Caspase-3蛋白 的表达;构建FOXC1敲低(sh-FOXC1)的HPV阳性宫颈癌细胞模型(Siha、Hela),利用Western blot检测FOXC1敲低后,细 胞内Caspase-3、Bcl-2、Bax、磷酸化NF-κB p65(p-NF-κB p65)和NF-κB p65蛋白表达变化;qRT-PCR检测FOXC1敲低后各 组细胞内NF-κB下游促炎因子IL-6、TNF-α mRNA表达水平。利用平板克隆、TUNEL凋亡检测技术分析FOXC1敲低对细 胞增殖、凋亡的影响;通过在Siha 细胞中sh-FOXC1组中过表达HPV16 E6验证HPV16 E6与FOXC1-NF-κB轴的调控关系, 通过Western blot检测各组细胞内E6、FOXC1、Caspase-3、Bcl-2、Bax、p-NF-κB p65和NF-κB p65蛋白表达变化;利用平 板克隆、TUNEL凋亡检测技术检测各组细胞增殖凋亡能力变化。结果 FOXC1蛋白表达量为正常组织的4.61倍,Ki-67表 达升高2.17倍,而凋亡标志物Caspase-3表达降低至正常组织的38.82%(P<0.01)。FOXC1蛋白在Siha、Hela细胞中的表达 量分别为C33A细胞的5.43倍和21.41倍,为永生化宫颈上皮细胞HCerEpiC的6.41倍和25.49倍(P<0.01)。Western blot结果 显示,敲低FOXC1表达后sh-FOXC1组促凋亡蛋白Caspase-3、Bax表达较对照Siha组升高1.94倍和1.66倍(P<0.05);抗凋 亡蛋白Bcl-2及p-NF-κB p65表达降低至55.41%和51.09%(P<0.05);总NF-κB p65无显著变化(P>0.05)。qRT-PCR结果显 示,与Siha组相比,sh-FOXC1细胞内NF-κB下游促炎因子IL-6、TNF-α mRNA表达降低(P<0.01)。平板克隆实验和 TUNEL凋亡检测结果显示,与sh-NON组相比,sh-FOXC1组细胞克隆形成率降至53.54%,凋亡水平升高,增加2.73倍(P <0.01),Hela细胞系的结果与其一致。在Siha 细胞中,Western blot结果显示,与sh-FOXC1组相比,sh-FOXC1-OE E6组 细胞内E6、FOXC1、p-NF-κB p65、Bcl-2蛋白表达分别回升1.36倍、4.17倍、4.26倍、3.34倍(P<0.05);Caspase-3、Bax 表达回降至61.77%和68.94%(P<0.05);细胞克隆形成的集落数量回升2.83倍(P<0.01);细胞凋亡率降低至45.54%(P< 0.01)。结论 HPV16 E6可能通过上调FOXC1激活NF-κB通路,进而促进宫颈癌细胞增殖并抑制凋亡,提示FOXC1可能成 为HPV阳性宫颈癌治疗的潜在靶点。

     

    Abstract: Background The E6 oncoprotein of human papillomavirus type 16 (HPV16) is a key factor in cervical carcinogenesis, yet its mechanisms mediating cell proliferation and apoptosis remain to be elucidated.Objective To investigate whether HPV16 E6 activates the NF-κB pathway via FOXC1 and elucidate the regulatory mechanism of FOXC1 in proliferation and apoptosis of HPV-positive cervical cancer cells.Methods Western blot was used to detect the expression of FOXC1, Ki-67 and Caspase-3 in cervical cancer and normal cervical tissue. HPV-positive cervical cancer cell models (Siha, Hela) with FOXC1 knockdown (sh-FOXC1) were constructed, and Western blot was used to detect the expression changes of Caspase-3, Bcl-2, Bax, phosphorylated NF-κB p65 (p-NF-κB p65) and NF-κB p65 in the cells after FOXC1 knockdown. qRT-PCR was used to detect the expression levels of NF-κB downstream pro-inflammatory factors IL-6 and TNF-α mRNA in each group of cells. Colony formation and TUNEL apoptosis assays were used to analyze the effects of FOXC1 knockdown on cell proliferation and apoptosis. Overexpression of HPV16 E6 in the sh-FOXC1 group of Siha cells was used to verify the regulatory relationship between HPV16 E6 and the FOXC1-NF-κB axis, and Western blot was used to detect the expression changes of E6, FOXC1, Caspase-3, Bcl-2, Bax, p-NF-κB p65 and NF-κB p65 in each group of cells. Colony formation and TUNEL apoptosis assays were used to detect the changes in cell proliferation and apoptosis ability in each group.Results FOXC1 protein expression was 4.61-fold higher in tumor tissues compared to normal controls (P<0.01), accompanied by a 2.17-fold increase in Ki-67 and a significant reduction of Caspase-3 to 38.82% of normal levels. In cell lines, FOXC1 expression showed 5.43-fold (SiHa) and 21.41-fold (HeLa) elevation versus C33A cells, and 6.41-fold/25.49-fold increases relative to immortalized HCerEpiC cells (all P<0.01). FOXC1 knockdown (sh-FOXC1) induced pro-apoptotic effects, with Caspase-3 and Bax expression increasing 1.94-fold and 1.66-fold respectively in SiHa cells (P< 0.05), while anti-apoptotic Bcl-2 and p-NF- κB p65 decreased to 55.41% and 51.09% (P<0.05). Total NF- κB p65 remained unchanged (P>0.05). Correspondingly, qRT-PCR demonstrated significant downregulation of NF-κB-dependent cytokines IL-6 and TNF-α mRNA (P<0.01). Functional assays showed sh-FOXC1 reduced colony formation by 46.46% (to 53.54% of control) and increased apoptosis 2.73-fold (P<0.01), with consistent results in HeLa cells. Rescue experiments through HPV16 E6 overexpression (sh-FOXC1-OE E6) reversed these effects: E6, FOXC1, p-NF-κB p65 and Bcl-2 rebounded 1.36-, 4.17-, 4.26- and 3.34-fold respectively (P<0.05), while Caspase-3/Bax declined to 61.77%/68.94% (P<0.05). This was associated with 2.83-fold increased colony formation (P<0.01) and reduced apoptosis to 45.54% of knockdown levels (P<0.01).Conclusion HPV16 E6 may activate the NF-κB pathway by upregulating FOXC1, thereby promoting the proliferation of cervical cancer cells and inhibiting apoptosis. These findings suggest that FOXC1 could potentially serve as a therapeutic target for HPV-positive cervical cancer.

     

/

返回文章
返回