背景:胰腺神经内分泌肿瘤(pNENs)相对罕见。低氧和脂质代谢相关基因乙酰辅酶A合成酶2(ACSS2)参与肿瘤的进展,但它在pNENs中的作用没有透露。本研究表明缺氧可上调ACSS2,其通过脂质代谢重编程在pNENs的发生和发展中起重要作用。然而,ACSS2在pNENs中的确切作用和机制尚不清楚。
方法:使用定量实时PCR(qRT-PCR)和蛋白质印迹(WB)检测ACSS2和3-羟基-3-甲基戊二酰辅酶A合成酶1(HMGCS1)的mRNA和蛋白质水平。ACSS2和HMGCS1对细胞增殖的影响采用CCK-8、集落形成试验和EdU试验,用transwell法检测了它们对细胞迁移和侵袭的影响。通过免疫共沉淀(Co-IP)实验验证了ACSS2和HMGCS1之间的相互作用,并通过裸鼠异种移植物确定体内ACSS2和HMGCS1的功能。
结果:我们证明缺氧可以上调ACSS2,而缺氧也促进pNENs的进展。ACSS2在pNEN中显著上调,ACSS2的过表达促进pNENs的进展,ACSS2和ACSS2抑制剂(ACSS2i)的敲低治疗抑制pNENs的进展。ACSS2调节pNENs中的脂质重编程和PI3K/AKT/mTOR通路,ACSS2通过PI3K/AKT/mTOR通路调节脂质代谢重编程。Co-IP实验表明HMGCS1与ACSS2在pNEN中相互作用。HMGCS1的过表达可以逆转ACSS2敲低的增强的脂质代谢重编程和促瘤作用。此外,HMGCS1的过表达逆转了ACSS2敲低对PI3K/AKT/mTOR通路的抑制作用。
结论:我们的研究表明,缺氧可以上调脂质代谢相关基因ACSS2,该基因通过激活PI3K/AKT/mTOR通路调节脂质代谢而发挥致瘤作用。此外,HMGCS1可以逆转ACSS2的致癌作用,为治疗策略提供了新的选择。
Pancreatic neuroendocrine neoplasms (pNENs) are relatively rare. Hypoxia and lipid metabolism-related gene acetyl-CoA synthetase 2 (ACSS2) is involved in tumor progression, but its role in pNENs is not revealed. This study showed that hypoxia can upregulate ACSS2, which plays an important role in the occurrence and development of pNENs through lipid metabolism reprogramming. However, the precise role and mechanisms of
ACSS2 in pNENs remain unknown.
mRNA and protein levels of ACSS2 and 3-hydroxy-3-methylglutaryl-CoA synthase1 (HMGCS1) were detected using quantitative real-time PCR (qRT-PCR) and Western blotting (WB). The effects of ACSS2 and HMGCS1 on cell proliferation were examined using CCK-8, colony formation assay and EdU assay, and their effects on cell migration and invasion were examined using transwell assay. The interaction between ACSS2 and HMGCS1 was verified by Co-immunoprecipitation (Co-IP) experiments, and the functions of ACSS2 and HMGCS1 in vivo were determined by nude mouse xenografts.
We demonstrated that hypoxia can upregulate ACSS2 while hypoxia also promoted the progression of pNENs.
ACSS2 was significantly upregulated in pNENs, and overexpression of
ACSS2 promoted the progression of pNENs and knockdown of
ACSS2 and
ACSS2 inhibitor (ACSS2i) treatment inhibited the progression of pNENs.
ACSS2 regulated lipid reprogramming and the PI3K/AKT/mTOR pathway in pNENs, and
ACSS2 regulated lipid metabolism reprogramming through the PI3K/AKT/mTOR pathway. Co-IP experiments indicated that HMGCS1 interacted with
ACSS2 in pNENs. Overexpression of HMGCS1 can reverse the enhanced lipid metabolism reprogramming and tumor-promoting effects of knockdown of ACSS2. Moreover, overexpression of HMGCS1 reversed the inhibitory effect of knockdown of ACSS2 on the PI3K/AKT/mTOR pathway.
Our study revealed that hypoxia can upregulate the lipid metabolism-related gene ACSS2, which plays a tumorigenic effect by regulating lipid metabolism through activating the PI3K/AKT/mTOR pathway. In addition, HMGCS1 can reverse the oncogenic effects of ACSS2, providing a new option for therapeutic strategy.