NF-κB信号通路介导的触珠蛋白对甲状腺乳头状癌生物学行为影响的机制研究

Haptoglobin (HP), an acute reactive protein, plays an important role in the inflammation reaction of the human body. In our previous research, we have found that HP was remarkably elevated in the serum and tumor tissues of PTC patients. Further studies have shown that HP could improve the proliferation activity and the capacity of immigration of PTC cells, which suggest that HP has an important influence on the biological behavior of PTC. However, the mechanism is unknown. NF-κB signaling pathway can be activated by inflammatory factors, and is involved in tumorgenesis by regulating many proliferation and apoptosis genes. HP ,as an acute reactive protein, is involved in an inflammatory reaction and shows remarkably high expression in PTC.We hypothesize that HP may influence the biological behavior of PTC by activating NF-κB signaling pathway..So far, there is no study examining the effects and mechanisms of HP on the biological behavior of PTC mediated by NF-κB signaling pathway. In this study, we will utilize the HP-shRNA lentivirus constructs to investigate the effects of HP on the biological behavior of PTC in vivo and in vitro. Through this study, we hope to get reliable proof of the effect of HP on the biological behavior of PTC and the mechanisms mediated by NF-κB signal pathway, which would provide foundation of HP as the molecular target for PTC.

触珠蛋白（HP）是一种急性反应蛋白，在机体炎症反应中具有重要的作用。申请人前期研究已经证实HP在甲状腺乳头状癌（PTC）患者血清和癌组织中显著高表达，且进一步研究显示：HP可促进PTC细胞的增殖和迁移，提示HP对PTC生物学行为具有重要影响，但具体机制尚未明了。NF-κB信号通路在炎症因子等刺激下发生活化，参与调控多种增殖及凋亡基因而引起肿瘤的发生。HP蛋白作为急性反应蛋白参与炎症反应并在PTC中显著高表达，推测HP对PTC生物学行为的影响可能与激活NF-κB通路有关。.目前尚未有NF-κB通路介导HP对PTC生物学行为影响机制方面的报道。本项目拟构建HP-shRNA慢病毒，通过体外体内实验研究NF-κB通路介导的HP对PTC生物学影响的机制。通过本课题的研究，可望获得HP对PTC生物学行为影响的可靠证据及NF-κB通路介导的分子机制，为进一步确立HP作为PTC的分子靶点奠定基础。

我国最新统计资料显示，近10年来，甲状腺癌的发病率增长了4.6倍，美国2013年新增甲状腺癌病例约为62,980，该恶性肿瘤已成为近20年来癌症谱中女性恶性肿瘤上升速度最快的肿瘤。PTC是甲状腺癌最常见的类型，约占甲状腺癌的80%。早期正确的诊断、及时合理的治疗对提高乳头状甲状腺癌长期生存率具有重要意义。.我们前期在筛选PTC分子标记物时，发现HP在PTC患者血清和癌组织中呈明显高表达。本课题在前期研究的基础上，进一步扩大样本量，检测HP在PTC患者癌组织及人PTC细胞株CGTH W3中的表达。随后构建HP-shRNA慢病毒质粒，通过感染人CGTH W3细胞株，获取HP稳定沉默的细胞单克隆，检测发现HP的阻断可抑制CGTH W3细胞的增殖、促进CGTH W3细胞的凋亡及抑制其迁移能力。此外，通过对NF-κB信号通路下游靶基因的检测，发现与未经干预的肿瘤细胞和感染阴性对照shRNA慢病毒的肿瘤细胞相比，感染有效HP-shRNA慢病毒的肿瘤细胞中与凋亡相关基因的表达显著增强，而肿瘤血管生成相关基因和细胞转移相关基因的表达显著降低。随后构建人PTC荷瘤裸鼠模型，进一步通过体内实验验证了HP的阻断对PTC生物学行为的影响及NF-κB信号通路介导的分子机制。.本研究发现HP对PTC生物学行为的影响与NF-κB信号通路密切相关。目前认为免疫过程中发生的炎症反应可能是促进癌症发生的一个关键因素，而HP作为急性反应蛋白参与了机体的许多炎症及免疫过程，此外，NF-κB信号通路介导了多种肿瘤与炎症间的分子联系，并且可被典型的炎症因子所激活。结合本研究结果，我们认为NF-κB信号通路介导了HP影响PTC生物学行为的分子事件，为PTC的早期诊断、寻找靶向分子标记，进而为恶性肿瘤的彻底治愈提供重要理论基础。