Cell Penetrating Peptide Inhibitor of FoxM1 in Hepatocellular Carcinoma Treatment

描述（由申请人提供）：人类肝细胞癌（HCC）是第五大常见癌症，但它是世界上最致命的癌症之一，因为肝癌的晚期发现和高复发频率使得目前的HCC治疗无效。我们之前的研究表明，增殖特异性Forkhead Box ml （Foxm1）转录因子缺乏（-/-）的小鼠肝细胞对二乙基亚硝胺(DEN)/苯巴比多（PB）诱导的肝癌具有高度抗性，并且Foxm1的转录活性被ARF肿瘤抑制因子的氨基酸26至44抑制。我们还开发了转基因（TG）小鼠，其中Rosa26启动子用于驱动人类FoxM1b cDNA转基因的普遍表达。我们开发了一种新的侵袭性转移性肝癌小鼠模型。暴露于DEN/PB 33周后，ARF-/- Rosa-26 FoxM1b TG小鼠肝脏坏死，并发展为转移到肺部的侵袭性HCC。在目的中，我们建议进一步表征这种侵袭性肝癌的增殖、发展和转移，并确定这些肝脏肿瘤是否表现出坏死和肝库普弗和星状细胞的活化。在初步研究中，我们通过给DEN/PB处理的野生型（WT）小鼠每天注射一种穿透细胞的ARF 24 - 46肽，从药理学上降低了Foxm1在体内HCC中的活性。经过4周的ARF肽治疗。肝细胞癌区域表现为细胞增殖和血管生成减少，肝细胞癌选择性凋亡。然而，这种ARF 26-44肽是否也能有效防止肝癌向肺转移还有待研究。在Aim2中，我们提出用细胞穿透性ARF 26-44肽治疗ARF -/- Rosa26 FoxM1b TG肝肿瘤可以抑制HCC生长和肺转移的假设。我们开发了一种新的TG小鼠系，在出生后肝细胞中有条件地表达活化的H-Ras。我们将用这些小鼠来检验活化的H-Ras是否会刺激DEN诱导的Rosa26-FoxM1b TG小鼠和ARF -/- Rosa26-FoxM1b TG小鼠的肝脏肿瘤的进展，以及细胞穿透ARF 26-44肽是否是限制这些肝脏肿瘤生长和进展的有效治疗方法。上述研究的完成将表征新的侵袭性转移性肝癌小鼠模型，并确定细胞穿透WT ARF 26-44肽是否是防止肝癌向肺转移的有效治疗方法。这些研究将为未来使用FoxM1转录因子的ARF肽抑制剂治疗人类肝癌的翻译研究提供合理的设计。

DESCRIPTION (provided by applicant): Human hepatocellular carcinoma (HCC) is the fifth most common cancer, yet it is among the most lethal cancers world wide because late detection and high frequency of tumor recurrence render current HCC therapy ineffective. We previously showed that mouse hepatocytes deficient (-/-) in the proliferation-specific Forkhead Box ml (Foxm1) transcription factor are highly resistant to developing Diethylnitrosamine (DEN)/Phenobarbital (PB) induced liver cancer and that FoxM1 transcriptional activity is inhibited by amino acids 26 to 44 from the ARF tumor suppressor. We also developed transgenic (TG) mice in which the Rosa26 promoter was used to drive ubiquitous expression of the human FoxM1b cDNA transgene. We have developed a new mouse model of aggressive metastatic liver cancer. After 33 weeks of DEN/PB exposure, ARF-/- Rosa-26 FoxM1b TG mouse livers are necrotic and develop aggressive HCC that metastasized to the lungs. In Aiml, we propose to further characterize the proliferation, development and metastasis of this aggressive liver cancer and determine whether these hepatic tumors exhibit necrosis and activation of hepatic Kupffer and stellate cells. In preliminary studies, we pharmacologically reduced Foxm1 activity in HCC in vivo by subjecting DEN/PB treated wild type (WT) mice to daily injections of a cell penetrating ARF 24 to 46 peptide. After 4 weeks of this ARF peptide treatment. HCC regions display reduced cell proliferation and angiogenesis with a selective apoptosis of HCC. However, whether this ARF 26-44 peptide is also effective in preventing metastasis of liver cancer to the lung remains to be determined. In Aim2, we propose to test the hypothesis that treatment of ARF -/- Rosa26 FoxM1b TG liver tumors with the cell penetrating ARF 26-44 peptide will inhibit HCC growth and lung metastasis. We have developed a new TG mouse line that conditionally expresses activated H-Ras in postnatal hepatocytes. We will use these mice to examine whether activated H-Ras stimulates progression of DEN induced liver tumors in both Rosa26-FoxM1b TG mice and ARF -/- Rosa26-FoxM1b TG mice and whether the cell penetrating ARF 26-44 peptide is an effective treatment to limit growth and progression of these liver tumors. Completion of the proposed studies will characterize new mouse models of aggressive metastatic liver cancer and determine whether the cell penetrating WT ARF 26-44 peptide is an effective treatment to prevent metastasis of liver cancer to the lung. These studies will facilitate development of a rational design for future translational research in the treatment of human liver cancer with this ARF peptide inhibitor of the FoxM1 transcription factor.