Cell Penetrating Peptide Inhibitor of FoxM1 in Hepatocellular Carcinoma Treatment

描述（由申请人提供）：人肝细胞癌（HCC）是第五大常见癌症，但它是世界范围内最致命的癌症之一，因为晚期检测和高频率的肿瘤复发使目前的HCC治疗无效。我们先前表明，小鼠肝细胞增殖特异性叉头盒ml（Foxm 1）转录因子缺陷（-/-）对二乙基亚硝胺（DEN）/苯巴比妥（PB）诱导的肝癌具有高度抗性，并且Foxm 1转录活性受到ARF肿瘤抑制因子氨基酸26至44的抑制。我们还开发了转基因（TG）小鼠，其中Rosa 26启动子用于驱动人FoxM 1b 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。在DEN/PB暴露33周后，ARF-/- Rosa-26 FoxM 1b TG小鼠肝脏坏死，并发生转移到肺部的侵袭性HCC。在Aiml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，并确定这些肝肿瘤是否表现出肝枯否细胞和星状细胞的坏死和活化。在初步研究中，我们通过每天注射细胞穿透ARF 24至46肽，使DEN/PB治疗的野生型（WT）小鼠体内HCC中的Foxm 1活性降低。在这种ARF肽治疗4周后。HCC区域显示减少的细胞增殖和血管生成，并具有HCC的选择性凋亡。然而，这种ARF 26-44肽是否也有效地防止肝癌转移到肺仍有待确定。在Aim 2中，我们提出检验用细胞穿透性ARF 26-44肽治疗ARF -/-Rosa 26 FoxM 1b TG肝肿瘤将抑制HCC生长和肺转移的假设。我们已经开发了一种新的TG小鼠系，在出生后的肝细胞中有条件地表达活化的H-Ras。我们将使用这些小鼠来检查活化的H-Ras是否刺激Rosa 26-FoxM 1b TG小鼠和ARF -/-Rosa 26-FoxM 1b TG小鼠中DEN诱导的肝肿瘤的进展，以及细胞穿透ARF 26-44肽是否是限制这些肝肿瘤生长和进展的有效治疗。完成拟议的研究将表征侵袭性转移性肝癌的新小鼠模型，并确定细胞穿透WT ARF 26-44肽是否是预防肝癌转移到肺的有效治疗。这些研究将有助于开发一个合理的设计，为未来的翻译研究，在人类肝癌的治疗与这种ARF肽抑制剂的FoxM 1转录因子。

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.