AMPK失活介导肿瘤细胞脂代谢重组促进胰腺癌神经浸润

Perineural invasion (PNI) usually causes recurrence and poor prognosis of postoperative pancreatic cancer patients, but its pathogenesis is unclear.Our preliminary study demonstrated that the metabolism disorders elevates pancreatic cancer cell invasion and metastasis ability and is closely related to the degree of PNI. AMP-activated protein kinase (AMPK) considered to be“cellular energy sensor” plays a crucial role in the regulation of cellular energy metabolism and inhibition of tumor progression . Thus we hypothesized that: AMPK deactivation promotes lipid metabolic disorder in pancreatic cancer which could stimulates nerve growth factor secretion and neural growth. To confirm this hypothesis, we will analyze the relationship between AMPK/lipogenesis and PNI in clinical features of pancreatic cancer patients. Then cell experiments, construction of PNI model in vitro and in vivo, KPC spontaneous pancreatic cancer mouse model are used to to observe the effects of lipogensis and PNI of pancreatic cancer under different conditions of AMPK. In addition, cell culture and molecular biology related technologies will be used to explore the underlying molecular mechanism. This project will reveal the role of AMPK/lipogenesis signaling pathway in PNI process, and undoubtedly will have theoretical significance and clinical applications, and will provide a new idea and target for drug treatment of PNI in pancreatic cancer.

神经浸润（PNI）是胰腺癌复发、预后差的重要原因，但其机制不明。课题组前期研究证实，体内体外能量代谢异常时胰腺癌细胞侵袭转移能力增强，并促进胰腺癌神经浸润; AMPK作为“细胞内能量调节器”，调控肿瘤细胞脂质代谢重组抑制胰腺癌进展。我们推测：胰腺癌细胞和组织AMPK失活通过介导脂质代谢紊乱，促进神经生长因子分泌和释放使神经突起迷乱性生长，从而加速肿瘤的生长和侵袭转移。本实验拟通过检测胰腺癌临床标本中AMPKα的表达并结合其临床病理特征、利用胰腺癌细胞-背根神经节共培养、裸鼠坐骨神经胰腺癌PNI模型、KPC胰腺癌转基因小鼠模型，从组织学、细胞学、分子生物学水平检测肿瘤组织AMPKα失活和干预后的活化状态、脂质代谢关键酶表达情况及对神经营养因子相关指标表达的影响，揭示AMPK/脂代谢重组途径在胰腺癌PNI中的作用机制。为胰腺癌PNI的治疗提供一种新思路。

神经浸润（PNI）是胰腺癌复发、预后差的重要原因，但其机制不明。课题组既往研究证实，体内体外能量代谢异常时胰腺癌细胞侵袭转移能力增强，并促进胰腺癌神经浸润；AMPK作为“细胞内能量调节器”，调控肿瘤细胞脂质代谢重组抑制胰腺癌进展；SREBP1作为细胞脂质代谢调节核心，其功能对胰腺癌的侵袭迁移意义重大。因此，我们推测：胰腺癌细胞和组织AMPK失活通过激活SREBP1，进而介导脂质代谢紊乱，促进神经生长因子分泌和释放使神经突起迷乱性生长，从而加速肿瘤的生长和侵袭转移。为证实该假说，本实验通过检测胰腺癌临床标本中AMPKα的表达并结合其临床病理特征、利用胰腺癌细胞-背根神经节共培养、裸鼠坐骨神经胰腺癌PNI模型、KPC胰腺癌转基因小鼠模型，拟从组织学、细胞学、分子生物学水平检测肿瘤组织AMPKα/SREBP1失活和干预后的活化状态、脂质代谢关键酶表达情况及对神经营养因子相关指标表达的影响，揭示AMPK-SREBP1轴介导的脂代谢重组途径在胰腺癌PNI中的作用机制。结果表明：临床病理染色显示p-AMPK在胰腺癌中低表达且低表达p-AMPK与胰腺癌的不良预后显著相关；体外胰腺癌细胞transwell和划痕实验证明，AMPK激活能和SREBP1敲低能显著抑制胰腺癌细胞的侵袭迁移，进一步，体外胰腺癌细胞-背根神经节共培养模型显示，AMPK激活和SREBP1敲低能显著抑制胰腺癌细胞的神经趋向性生长和脊髓背根神经节神经丝的迷乱性生长；值得一提的，AMPK对胰腺癌细胞侵袭迁移和PNI的影响是由SREBP1所介导；此外，体内实验亦证实AMPK激活能显著抑制胰腺癌细胞延神经的侵袭性生长和KPC小鼠胰腺肿瘤的生长与侵袭迁移。综上结果，我们得出结论：AMPK失活介导肿瘤细胞SREBP1活化促进胰腺癌神经浸润。