Molecular mechanism of bitter melon juice efficacy against pancreatic cancer.

描述（由申请人提供）：胰腺癌（PanC）是一种侵袭性疾病；PanC患者诊断后的中位生存期<6个月，总5年生存率为3-5%。吉西他滨是治疗PanC的一线化疗药物，可有效消除大量PanC细胞；然而，癌症干细胞（CSC）导致癌症复发和侵袭性。总之，很明显，迫切需要额外的策略来有效降低PanC发病率，靶向CSC以控制PanC复发和相关死亡率。值得注意的是，PanC是一种具有多种突变组合的复杂疾病，因此有必要确定具有多靶点的药物来控制PanC生长和csc相关的PanC复发。我们发表的和初步的研究表明，苦瓜汁（BMJ）显著降低人PanC细胞系的活力并诱导强烈的凋亡，这与AMPK的强大激活有关，因为AMPK抑制剂和siRNA都逆转了BMJ引起的细胞凋亡。此外，BMJ抑制PanC细胞的糖酵解和氧化磷酸化速率。综上所述，这些结果表明PanC细胞中的BMJ发生了“代谢转变”。BMJ还能强烈抑制PanC CSCs的球形形成，提示其抗PanC作用也针对CSC。最值得注意的是，仅以5mg剂量/只/天灌胃BMJ，对裸鼠MIA PaCa-2异种移植物生长有60%的抑制作用，没有任何明显的副作用或毒性。异种移植物的免疫组织化学分析表明，BMJ还能抑制增殖和CSC生物标志物，诱导细胞凋亡，并激活AMPK。总之，基于这些和其他研究结果，我们假设BMJ通过营养应激、AMPK激活和抑制与代谢和增殖相关的信号分子导致PanC细胞的代谢转变，从而导致PanC细胞特异性的强烈生长抑制和凋亡。此外，BMJ靶向Notch/ Hedgehog信号通路，有效消除PanC CSC群体；从而产生对PanC的强活性。提出的具体目的是：1)进一步明确BMJ靶向代谢并影响ampk介导的PanC细胞生长抑制和凋亡的机制；II)进一步明确BMJ靶向Notch和Hedgehog通路并有效抑制PanC中CSC群体的机制；III)进一步建立PDX1-Cre中特定目的I和II所定义的BMJ分子机制；LSL-KRASG12D转基因小鼠模型。这里需要强调的是，苦瓜作为蔬菜和果汁被广泛食用，尤其是在亚洲国家；具有抗糖尿病、抗炎等多种保健功效。最值得注意的是，苦瓜有

DESCRIPTION (provided by applicant): Pancreatic cancer (PanC) is an aggressive disease; median life of PanC patients post-diagnosis is <6 months and overall 5-year survival rate is 3-5%. Gemcitabine is the frontline chemotherapy for PanC that effectively eliminates bulk PanC cells; however spares cancer stem cell (CSC) population which causes cancer relapse as well as aggressiveness. Together, it is clear that additional strategies are urgently warranted to effectively lower PanC incidence, target CSC to control PanC relapse, and associated mortality. Noteworthy, PanC is a complex disease with multiple combinations of mutations, and therefore it is necessary to identify the agents with multiple targets to control both PanC growth and CSC-associated PanC relapse. Our published and preliminary studies show that bitter melon (Momordica charantia) juice (BMJ) significantly decreases the viability and induces strong apoptotic death of human PanC cell lines, which was associated with a robust AMPK activation, as both AMPK inhibitor and siRNA reversed BMJ-caused apoptosis. Furthermore, BMJ inhibited glycolysis and oxidative phosphorylation rate in PanC cells. Together these results suggested a 'metabolic shift' by BMJ in PanC cells. BMJ also strongly inhibited the sphere formation by PanC CSCs suggesting that it also targets CSC for its anti-PanC efficacy. Most notably, BMJ feeding by oral gavage at only 5mg dose/mouse/day resulted in 60% inhibition in MIA PaCa-2 xenograft growth in nude mice without any noticeable side effects or toxicity. Immunohistochemical analysis of xenografts showed that BMJ also inhibits proliferation and CSC biomarkers, induces apoptosis, and activates AMPK in vivo. Together, based on these and other findings, we hypothesize that BMJ causes metabolic shift in PanC cells through nutrient stress, AMPK activation and inhibiting signaling molecules related to metabolism and proliferation, which leads to strong growth inhibition and apoptosis specifically in PanC cells. Additionally, BMJ targets Notch/ Hedgehog signaling to effectively eliminate PanC CSC population; resulting in strong activity against PanC. The specific aims proposed are: I) To further define the mechanisms by which BMJ targets metabolism and affects AMPK-mediated growth inhibition and apoptosis in PanC cells; II) To further define the mechanisms by which BMJ targets Notch and Hedgehog pathways and effectively inhibits CSC population in PanC; and III) To further establish BMJ molecular mechanisms defined in specific aims I and II in PDX1-Cre; LSL-KRASG12D transgenic mouse model. It is important to highlight here that bitter melon is widely consumed as vegetable as well as juice especially in Asian countries; and has been attributed with multiple health beneficial properties such as anti-diabetic, anti-inflammatory, etc. Most notably, bitter melon has been tested in several clinical trials for its anti-diabetic effects and has plenty of human safety data. We, therefore, anticipate that the positive outcomes from the proposed studies will provide compelling rationale for initiating clinical trials to establish BMJ activity against human pancreatic cancer.