Glycolytic signaling of p38gamma in breast cancer

三阴性乳腺癌不表达雌激素受体(ER)、孕激素受体(PR) 和Her2作为治疗靶点，因此在所有类型的乳腺癌中预后最差。 代谢重新编程朝向有氧糖酵解(也称为沃堡效应)是癌症的一个标志， 它在TNBC中被进一步激活。尽管有氧糖酵解可能在治疗上具有靶向性，但可用药 途径尚未确定。P38是一种tnbc癌基因，可刺激葡萄糖摄取和代谢。 适应。这一提议将检验p38通过刺激促进肿瘤细胞发生的假设。 依赖于PFKFB3/GLUT1的有氧糖酵解。 这一假设基于以下发现：1)p38刺激葡萄糖转运蛋白1(GLUT1) 表达并增加葡萄糖摄取；2)p38促进肿瘤发生；3)TNBCs高度 P38与糖酵解关键激活剂pFKFB3结合 而它与糖酵解三个家族成员(PFKFB1，2和4)在非 5)MS/MS分析鉴定p38使pFKFB3在S467处磷酸化，从而使其稳定， 而公共数据库的数据显示p38基因表达与侵袭性GLUT1相关 乳腺癌组织；6)条件性p38基因敲除(KO)抑制肿瘤细胞样PYMT小鼠的肿瘤形成 遗传性乳腺癌模型及pFKFB3/GLUT1的表达下调；7)p38在肿瘤细胞中的过表达 细胞增加了PFKFB3/GLUT1的丰度，促进了它们的相互作用，并刺激了ECAR(一种 糖酵解)，表明其通过形成三元络合物刺激有氧糖酵解的活性；以及8) 药理p38和pFKFB3抑制剂协同降低p-pFKFB3/pFKFB3/GLUT1水平和 以依赖p38的方式抑制肿瘤细胞生长。这些结果共同表明p38链接 通过激活PFKFB3和GLUT1的有氧糖酵解和TNBC肿瘤发生。 我们将通过以下目标来验证这一假设：目标1将调查p38是否与有氧 糖酵解与PFKFB3相互作用及对PFKFB3的刺激与TNBC致癌 AIM2将决定p38是否与pFKFB3和GLUT1协同促进 通过刺激S467依赖的三元复合体的有氧糖酵解和TNBC致癌作用；AIM 3将 确定p38-pFKFB3激酶级联是否为肿瘤的治疗靶点，以及p38/pFKFB3/Glut1是否为治疗靶点 P-PFKFB3升高共同上调可确定临床上预后较差的TNBC亚型。这些 研究将证明p38-pFKFB3激酶级联是否为肿瘤的新治疗靶点，并揭示 如果联合应用p38/pFKFB3药物抑制剂是一种潜在的有效治疗方法 将影响TNBC临床结果和退伍军人医疗保健的战略。

Triple-negative breast cancer (TNBC) does not express estrogen receptor (ER), progesterone receptor (PR) and Her2 as therapeutic targets and consequently has the worst prognosis among all types of breast cancers. Metabolic reprogramming toward aerobic glycolysis (also called the Warburg effect) is a hallmark of cancer, which is further activated in TNBC. Although aerobic glycolysis may be therapeutically targeted, the druggable pathway has not been identified. p38 is a TNBC oncogene and stimulates glucose uptake and metabolic adaption. This proposal will test the hypothesis that p38 promotes TNBC oncogenesis by stimulating PFKFB3/GLUT1-dependent aerobic glycolysis. This hypothesis is based on the following findings: 1) p38 stimulates glucose transporter 1 (GLUT1) expression and increases glucose uptake; 2) p38 promotes TNBC oncogenesis; 3) TNBCs are highly glycolytic with elevated PFKFB3 and GLUT1 expression; 4) p38 binds PFKFB3, a key glycolytic activator, in TNBC cells, whereas it interacts with much less glycolytic three family members (PFKFB1, 2 and 4) in non- TNBC cells; 5) MS/MS analysis identifies that p38 phosphorylates PFKFB3 at S467 leading to its stabilization, whereas data from public data-base shows that p38 gene expression is correlated with GLUT1 in invasive breast cancer tissues; 6) conditional p38 knockout (KO) inhibits tumorigenesis in a TNBC-like PyMT mouse genetic breast cancer model and decreases PFKFB3/GLUT1 expression; 7) p38 overexpression in TNBC cells increases PFKFB3/GLUT1 abundance, promotes their interaction, and stimulates ECAR (an indicator of glycolysis), indicating its activity of stimulating aerobic glycolysis by forming a ternary complex; and 8) pharmacological p38 and PFKFB3 inhibitors cooperatively decrease p-PFKFB3/PFKFB3/GLUT1 levels and inhibit TNBC growth in a manner dependent on p38. These results together indicate that p38 links aerobic glycolysis and TNBC oncogenesis through activating PFKFB3 and GLUT1. We will test this hypothesis by targeting the following aims: AIM 1 will investigate if p38 links aerobic glycolysis and TNBC oncogenesis through interaction with PFKFB3 and stimulating of PFKFB3 phosphorylation at S467; AIM 2 will determine if p38 cooperates with both PFKFB3 and GLUT1 to promote aerobic glycolysis and TNBC oncogenesis by stimulating a S467-dependent ternary-complex; and AIM 3 will determine if the p38-PFKFB3 kinase cascade is a therapeutic target for TNBC and if the p38/PFKFB3/Glut1 co-upregulation with elevated p-PFKFB3 identifies a subgroup of TNBC with a worse prognosis in clinic. These studies will demonstrate if the p38-PFKFB3 kinase cascade is a novel therapeutic target for TNBC and reveal if a combined application of p38/PFKFB3 pharmacological inhibitors is a potential effective therapeutic strategy that will impact TNBC clinical outcome and veteran health care.