The role of membrane lipid remodeling in cancer cell ferroptosis sensitivity

项目摘要 磷脂是生物膜的主要成分，是所有细胞生命所必需的。 肿瘤细胞的磷脂代谢发生改变。然而，目前还没有批准的抗癌药物 以磷脂代谢酶为靶标。抑制促进生存的磷脂代谢酶 将提出一种诱导癌细胞死亡的新策略。铁下垂是细胞死亡的一种形式， 依赖于膜磷脂的组成。铁性下垂是由膜直接损伤引起的。 由活性氧基(ROS)产生的磷脂。我们的团队和其他人发现，这些尾巴群 磷脂可以决定细胞对铁性下垂的敏感度。具有多个双键的尾基 (多不饱和脂肪酸，PUFA)比那些只有一个双键的更容易被氧化 (单不饱和脂肪酸，MUFA)因此，多不饱和脂肪酸水平较高的细胞更容易死亡 通过铁性下垂，而MUFAs水平较高的细胞抵抗铁性下垂。这与癌症尤其相关。 治疗是因为诱导铁下垂正在成为一种有效的杀死癌细胞的策略。在预赛中 研究发现，膜结合O-酰基转移酶1(MBOAT1)是一个新的铁下垂调控基因。 MBOAT1是一种将多不饱和脂肪酸结合到磷脂中的脂类代谢基因。MBOAT1基因表达或 拷贝数在多种肿瘤类型中升高，且MBOAT1高表达与差相关 胰腺癌患者的预后。我发现抑制MBOAT1增加了癌细胞对 铁性下垂。因此，MBOAT1代表了癌症治疗的新靶点。基于这些发现，我 假设MBOAT1的抑制通过改变磷脂使细胞对铁性下垂敏感 新陈代谢。在目标1中，我将阐明MBOAT1在铁下垂敏感性和磷脂中的作用 新陈代谢。然后，在目标2中，我将测试MBOAT1抑制和铁下垂诱导的组合作为一种新的 体内治疗癌症的策略。总体而言，这项工作将具有生物学意义，通过表征 MBOAT1的功能和调控及其作为新靶点的临床意义 在癌细胞中诱导铁性下垂。

Project Summary Phospholipids are the major component of biological membranes and are essential for all cellular life. Phospholipid metabolism is altered in tumor cells. However, there are currently no approved anti-cancer drugs that target phospholipid metabolic enzymes. Inhibition of survival-promoting phospholipid metabolic enzymes would present a novel strategy to induce cell death in cancer cells. Ferroptosis is a form of cell death that is dependent on membrane phospholipid composition. Ferroptosis is caused by direct damage to membrane phospholipids by reactive oxygen species (ROS). Our group and others have found that the tail groups of phospholipids can determine a cell’s sensitivity to ferroptosis. Tail groups with multiple double-bonds (polyunsaturated fatty acids, PUFAs) are more likely to be oxidized than those with only one double bond (monounsaturated fatty acid, MUFA). Therefore, cells with greater levels of PUFAs are more susceptible to death by ferroptosis, whereas cells with greater levels of MUFAs resist ferroptosis. This is particularly relevant in cancer treatment because induction of ferroptosis is emerging as an effective strategy to kill cancer cells. In preliminary studies, I find that Membrane-Bound O-Acyltransferase 1 (MBOAT1) is a novel ferroptosis regulating gene. MBOAT1 is a lipid metabolic gene that incorporates MUFAs into phospholipids. MBOAT1 gene expression or copy number is elevated in multiple tumor types, and higher expression of MBOAT1 is correlated with poor prognosis in pancreatic cancer patients. I find that inhibiting MBOAT1 increases cancer cells’ susceptibility to ferroptosis. Therefore, MBOAT1 represents a novel target for cancer treatment. Based on these findings, I hypothesize that inhibition of MBOAT1 sensitizes cells to ferroptosis by altering phospholipid metabolism. In Aim 1, I will elucidate the role of MBOAT1 in ferroptosis sensitivity and in phospholipid metabolism. Then in Aim 2, I will test the combination of MBOAT1 inhibition and ferroptosis induction as a novel strategy for the treatment of cancer in vivo. Overall, this work will have biological significance by characterizing the function and regulation of MBOAT1, and clinical significance by establishing MBOAT1 as a novel target to induce ferroptosis in cancer cells.