BACKGROUND Metabolic reprogramming is one of the hallmarks of cancer which favours rapid energy production, biosynthetic capabilities and therapy resistance. In our previous study, we showed bitter melon extract (BME) prevents carcinogen induced mouse oral cancer. RNA sequence analysis from mouse tongue revealed a significant modulation in "Metabolic Process" by altering glycolysis and lipid metabolic pathways in BME fed group as compared to cancer group. In present study, we evaluated the effect of BME on glycolysis and lipid metabolism pathways in human oral cancer cells. METHODS Cal27 and JHU022 cells were treated with BME. RNA and protein expression were analysed for modulation of glycolytic and lipogenesis genes by quantitative real-time PCR, western blot analyses and immunofluorescence. Lactate and pyruvate level was determined by GC/MS. Extracellular acidification and glycolytic rate were measured using the Seahorse XF analyser. Shotgun lipidomics in Cal27 and JHU022 cell lines following BME treatment was performed by ESI/ MS. ROS was measured by FACS. RESULTS Treatment with BME on oral cancer cell lines significantly reduced mRNA and protein expression levels of key glycolytic genes SLC2A1 (GLUT-1), PFKP, LDHA, PKM and PDK3. Pyruvate and lactate levels and glycolysis rate were reduced in oral cancer cells following BME treatment. In lipogenesis pathway, we observed a significant reduction of genes involves in fatty acid biogenesis, ACLY, ACC1 and FASN, at the mRNA and protein levels following BME treatment. Further, BME treatment significantly reduced phosphatidylcholine, phosphatidylethanolamine, and plasmenylethanolamine, and reduced iPLA2 activity. Additionally, BME treatment inhibited lipid raft marker flotillin expression and altered its subcellular localization. ER-stress associated CHOP expression and generation of mitochondrial reactive oxygen species were induced by BME, which facilitated apoptosis. CONCLUSION Our study revealed that bitter melon extract inhibits glycolysis and lipid metabolism and induces ER and oxidative stress-mediated cell death in oral cancer. Thus, BME-mediated metabolic reprogramming of oral cancer cells will have important preventive and therapeutic implications along with conventional therapies.

中文翻译：

---

苦瓜提取物抑制口腔癌的关键代谢途径，糖酵解和脂肪生成。

背景代谢重编程是癌症的标志之一，它有利于快速产生能量、生物合成能力和治疗抗性。在我们之前的研究中，我们发现苦瓜提取物 (BME) 可预防致癌物诱发的小鼠口腔癌。小鼠舌头的 RNA 序列分析显示，与癌症组相比，BME 喂养组通过改变糖酵解和脂质代谢途径对“代谢过程”进行了显着调节。在本研究中，我们评估了 BME 对人类口腔癌细胞糖酵解和脂质代谢途径的影响。方法用BME处理Cal27和JHU022细胞。通过实时定量 PCR、蛋白质印迹分析和免疫荧光分析 RNA 和蛋白质表达以调节糖酵解和脂肪生成基因。乳酸和丙酮酸水平通过 GC/MS 测定。使用 Seahorse XF 分析仪测量细胞外酸化和糖酵解速率。BME 处理后的 Cal27 和 JHU022 细胞系中的鸟枪法脂质组学通过 ESI/MS 进行。ROS 通过 FACS 测量。结果 BME 对口腔癌细胞系的治疗显着降低了关键糖酵解基因 SLC2A1 (GLUT-1)、PFKP、LDHA、PKM 和 PDK3 的 mRNA 和蛋白质表达水平。BME 处理后，口腔癌细胞的丙酮酸和乳酸水平以及糖酵解率降低。在脂肪生成途径中，我们观察到 BME 处理后在 mRNA 和蛋白质水平上参与脂肪酸生物合成的基因 ACLY、ACC1 和 FASN 显着减少。此外，BME 处理显着减少了磷脂酰胆碱、磷脂酰乙醇胺和 plasmenylethanolamine，并降低 iPLA2 活性。此外，BME 处理抑制了脂筏标记 flotillin 的表达并改变了其亚细胞定位。BME 诱导 ER 应激相关的 CHOP 表达和线粒体活性氧的产生，从而促进细胞凋亡。结论 我们的研究表明，苦瓜提取物抑制糖酵解和脂质代谢，并诱导口腔癌中的 ER 和氧化应激介导的细胞死亡。因此，BME 介导的口腔癌细胞代谢重编程将与常规疗法一起具有重要的预防和治疗意义。BME 诱导 ER 应激相关的 CHOP 表达和线粒体活性氧的产生，从而促进细胞凋亡。结论 我们的研究表明，苦瓜提取物抑制糖酵解和脂质代谢，并诱导口腔癌中的 ER 和氧化应激介导的细胞死亡。因此，BME 介导的口腔癌细胞代谢重编程将与常规疗法一起具有重要的预防和治疗意义。BME 诱导 ER 应激相关的 CHOP 表达和线粒体活性氧的产生，从而促进细胞凋亡。结论 我们的研究表明，苦瓜提取物抑制糖酵解和脂质代谢，并诱导口腔癌中的 ER 和氧化应激介导的细胞死亡。因此，BME 介导的口腔癌细胞代谢重编程将与常规疗法一起具有重要的预防和治疗意义。