Identifying a network of microRNAs and genes that regulate breast tumor metastasis

方案：确定调节乳腺肿瘤转移的miRNAs和基因网络 摘要 转移是乳腺癌患者死亡的主要原因。然而，分子机制 潜在的肿瘤发生和转移尚不清楚。我们最近发现了肿瘤起始细胞（TIC） 从人类乳腺肿瘤1，2. TIC携带干细胞的某些特性，对常规免疫更有抵抗力， 癌症治疗，并参与肿瘤转移。如何有效靶向TIC或转移启动 因此，细胞（MIC）成为最具挑战性的问题之一。内源性单链小RNA的20- 长度为22个核苷酸，称为microRNA（miRNAs，miRs），已经成为一种强大的调节因子， 肿瘤进展3-15。在这个项目中，我们的目标是表征调节人类乳腺癌的新型miR 启动和转移并鉴定其靶基因。在我们未来的努力中，我们将研究miR 在转录水平的调控机制，并进一步将我们的理解转化为临床 例如新的癌症生物标志物或治疗剂。 大多数先前的转移模型由于遗传因素而在其完全代表人类肿瘤的能力方面受到限制。 人类癌细胞系培养物中积累的变化，小鼠肿瘤模型中的遗传差异 与人类肿瘤相比，通过血液接种绕过了转移的自然步骤。这 该项目将利用我们最近建立的人鼠乳腺癌模型， 来源于临床肿瘤标本，并在发生自发性肺或淋巴结转移后 原位移植到小鼠乳腺脂肪垫中。密切监测乳腺肿瘤的发生， 在体内转移中，我们还用光学报告分子转导了原代癌细胞，并改善了肿瘤细胞的生物学特性。 通过非侵入性生物发光成像，检测灵敏度可达10个体内细胞。MiR更稳定， 比mRNA更耐分析方案，因此作为有前途的新型癌症生物标志物。此外，委员会认为， 它们是内源性小RNA，与复方药物相比毒性小，因此有望 作为创新的癌症治疗方法。 我们的长期目标是联合收割机结合我们对肿瘤发生和转移的理解， 学科技术（如化学和生物工程），以改善临床医学和减少癌症 mortality. 转录 因素 体内 肿瘤起始 转移 Future 1 新型mirna 1 未来2 体外 肿瘤生长 细胞侵袭 目标差异化 基因耐药性 临床前 生物标记 Therapeutics 2 目的示意图：（1）表征和验证miRNA候选功能，（2） 确定miRNA靶点及其在BTIC和转移中的重要性，（未来1）转录 转录因子对miRNAs的调控，以及（未来2）miRNAs的临床前研究 以及作为乳腺癌的新生物标志物和/或治疗靶点的基因。

Proposal: Identifying a network of miRNAs and genes that regulate breast tumor metastasis Abstract Metastasis is the major cause of death in breast cancer patients. However, the molecular mechanisms underlying tumor initiation and metastasis are not clear. We have recently identified tumor initiation cells (TICs) from human breast tumors 1,2. TICs carry certain properties of stem cells, are more resistant to conventional cancer therapies, and are involved in tumor metastasis. How to effectively target TICs or metastasis initiating cells (MICs) thus becomes one of the most propelling questions. Endogenous single strand small RNAs of 20- 22 nucleotides in length, known as microRNAs (miRNAs, miRs), have emerged to be powerful regulators of tumor progression 3-15. In this project, we aim to characterize novel miRs that regulate human breast cancer initiation and metastasis and identify their target genes. Then in our future endeavors, we will examine miR regulation mechanisms at the transcriptional level and further translate our understanding to clinical applications, such as novel cancer biomarkers or therapeutics. Most previous metastasis models are limited in their ability to fully represent human tumors, due to genetic changes accumulated in culture for human cancer cell lines, genetic differences in mouse tumor models compared to human tumors, and bypassing the natural steps of metastasis via bloodstream inoculations. This project will take advantage of our recently established human-in-mouse breast cancer models, which are derived from clinical tumor specimens and develop spontaneous lung or lymph node metastases upon orthotopic transplantation into mouse mammary fat pads. To closely monitor breast tumor initiation and metastasis in vivo, we have also transduced primary cancer cells with optical reporters and improved the detection sensitivity to 10 cells in vivo via non-invasive bioluminescence imaging. MiRs are more stable and resistant to analysis protocols than mRNAs, thus serving as promising novel cancer biomarkers. Furthermore, they are endogenous small RNAs with little toxicity compared to compound drugs; therefore hold the promise to be developed as innovative cancer therapeutics. Our long-term goal is to combine our understanding of tumor initiation and metastasis with knowledge in multi- disciplinary technology (such as chemistry and bioengineering) to improve clinical medicine and reduce cancer mortality. Transcription Factors In vivo Tumor initiation metastasis Future 1 Novel miRNAs 1 Future 2 In vitro Tumor growth Cell invasion Target Differentiation Genes Drug-resistance Preclinical Biomarkers Therapeutics 2 A schematic figure of aims: (1) to characterize and validate miRNA candidate functions, (2) to identify miRNA targets and their importance in BTICs and metastasis, (Future 1) transcriptional regulation of miRNAs by transcriptional factors, and (Future 2) preclinical studies of miRNAs and genes serving as novel biomarkers and/or therapeutic targets for breast cancer.