Silencing CD44v6 Expression Prevents Intestinal Tumor Growth

沉默 CD44v6 表达可防止肠道肿瘤生长

• 批准号: 8633018
• 负责人: SUNITI MISRA
• 金额: $ 7.25万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-06 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8633018
• 关键词: ALCAM gene; Address; Agar; Basic Science; Behavior; Binding; Biological Markers; CD44 gene; Cancer Detection; Cancer Etiology; Cell Survival; Cells; Cessation of life; Chemoprevention; Chemopreventive Agent; Colon; Colon Carcinoma; Colonic Adenoma; Colonic Neoplasms; Companions; Cytoplasm; Development; Diagnosis; Dinoprostone; Drug Kinetics; Drug resistance; Environment; Exons; Glycoproteins; Growth; Health; Hyaluronan; In Vitro; Incidence; Integral Membrane Protein; Intestinal Neoplasms; Intestines; Lead; Lesion; Ligands; Malignant Neoplasms; Measurement; Mediator of activation protein; Molecular; Morbidity - disease rate; Mus; Normal Cell; Oncogenic; Outcome; PTEN gene; PTGS2 gene; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacodynamics; Phenotype; Physiological; Plasmids; Play; Population; Preventive; Process; Property; Proteins; Proto-Oncogene Proteins c-akt; Rectal Cancer; Regimen; Regulation; Role; Serum; Serum Markers; Signal Pathway; Signal Transduction; Sorting - Cell Movement; System; Testing; Time; Tissues; Transfection; Translating; United States; Work; adenoma; base; cancer chemoprevention; cancer stem cell; cell growth; dosage; hyaluronan synthase 1; improved; in vivo; knock-down; meetings; mortality; mouse model; nanoparticle; neoplastic cell; novel; overexpression; prevent; protein expression; public health relevance; small hairpin RNA; stem cell population; tool; tumor; tumor growth; tumor progression; tumorigenic

DESCRIPTION (provided by applicant): Colon cancer is the second common cause of mortality and morbidity in the United States. Despite recent advances in the treatment of colon cancer, there are no effective chemopreventive treatments available at this time and the outcome tends to be poor in these available strategies for a high number of patients. The work described in this proposal explores a novel chemopreventive approach which targets pro-oncogenic CD44v6 protein expressions that block the development of colon cancer. We have developed a novel nanoparticle delivery system that selectively directs CD44v6shRNA to intestine/colon cells and blocks adenoma formation. This approach is supported by the following observations: (1) CD44v6 is overexpressed in adenoma cells compared to normal cells. (2) CD44v6 is a specific cancer stem cell marker than total CD44, and can be used in conjunction with CD166 or CD133 to isolate cancer stem cells. (3) Knocking down CD44v6 expression in vivo reduces the size and number of adenomas in the Apc Min/+ mouse model, in which adenomas grow spontaneously. 4) Knocking down CD44v6 in sorted cancer stem cells reverses their drug resistance and the growth in soft agar. 5) Knocking down CD44v6 in pre-adenoma Apc10.1 cells inhibits signaling downstream from the binding of HA to CD44v6, and the binding of HGF to CD44v6 and c-Met. These observations suggest the hypothesis that CD44v6 is a key transmembrane protein in the regulation of intestine/colon tumor cell growth initiation and progression: we postulate that blocking CD44v6 expression by CD44v6shRNA delivered "early" (before adenomas develop) via nanoparticles into weanling Apc Min/+ mice will effectively prevent adenoma formation. We also postulate that tissue-specific delivery of CD44v6shRNA/nanoparticles provide a novel tissue targeted chemopreventive approach. We have two aims: Aim 1) To determine the efficacy and pharmacokinetics of CD44v6shRNA in intestinal adenomas using a weanling Apc Min/+ mouse model. Efficacy will be defined as effects of CD44v6shRNA on adenoma size/number. Pharmacokinetics of CD44v6shRNA will be determined by studying the distribution of CD44v6shRNA as well as Cre plasmid in the targeted intestine adenomas in comparison with that of normal intestine/colon tissues. Aim 2) To determine the effect of CD44v6shRNA on: pharmacodynamic markers (components of the CD44v6- induced c-Met signaling cascade) in adenoma tissue; biomarkers of adenoma formation and progression (HGF, HA, PGE2 and soluble CD44v6) in serum; and cancer stem cell markers (CD44v6, CD166, CD133 and p- PTEN) in early intestinal adenomas in the Apc Min/+ mouse model. The proposed studies will advance the potential of CD44v6shRNA as a chemopreventive agent to alter the behavior of cancer precursor lesions.

描述（由申请人提供）：结肠癌是美国死亡率和发病率的第二个常见原因。尽管最近在结肠癌治疗方面取得了进步，但目前尚无有效的化学预防治疗，对于大量患者，这些可用策略的结果往往很差。该提案中描述的工作探讨了一种新型的化学预防方法，该方法靶向促进性CD44V6蛋白表达，阻断结肠癌的发展。我们已经开发了一种新型的纳米粒子递送系统，该系统有选择地将CD44V6SHRNA定向到肠/结肠细胞并阻止腺瘤形成。这种方法得到以下观察结果的支持：（1）与正常细胞相比，腺瘤细胞中CD44V6过表达。 （2）CD44V6是比总CD44的特定癌症干细胞标记物，可与CD166或CD133结合使用以分离癌症干细胞。 （3）在体内敲低CD44V6的表达可减少APC最小/+小鼠模型中腺瘤中腺瘤的大小和数量，其中腺瘤自发生长。 4）在排序的癌症干细胞中敲低CD44V6会逆转其耐药性和软琼脂的生长。 5）在添加腺瘤前APC10.1细胞中击倒CD44V6会抑制从HA与CD44V6结合的下游信号传导，以及HGF与CD44V6和C-MET的结合。这些观察结果表明，CD44V6是调节肠/结肠肿瘤细胞生长的开始和进展的关键跨膜蛋白：我们假设，通过CD44V6SHRNA的CD44V6表达“早期”（通过adenomas在Adenomas开发）通过Nanaparticles向Weeanling Apc Mine构建，将CD44V6表达为“早期”。我们还假设CD44V6SHRNA/纳米颗粒的组织特异性递送提供了一种新型的组织靶向化学预防方法。我们有两个目的：目标1）确定使用断奶APC最小/+小鼠模型在肠道腺瘤中CD44V6SHRNA的功效和药代动力学。功效将定义为CD44V6SHRNA对腺瘤大小/数量的影响。与正常肠道/结肠组织相比，CD44V6SHRNA的药代动力学将通过研究靶向肠腺瘤中CD44V6SHRNA以及CRE质粒的分布来确定。目标2）确定CD44V6SHRNA对：药效学标记物（CD44V6诱导的C-MET信号级联的成分）在腺瘤组织中的影响；血清中腺瘤形成和进展的生物标志物（HGF，HA，PGE2和可溶性CD44V6）；和癌细胞标记（CD44V6，CD166，CD133和P-PTEN）在APC最小/+小鼠模型中的早期肠道腺瘤中。拟议的研究将提高CD44V6SHRNA作为化学预防剂的潜力，以改变癌症前体病变的行为。