Role of a Two-Factor Genetic Circuit Regulating Stemness in Colorectal Cancer

调节干性的双因素遗传回路在结直肠癌中的作用

• 批准号: 10364645
• 负责人: Sofia Hu
• 金额: $ 5.18万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-10-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10364645
• 关键词: Address; Affect; Automobile Driving; Binding; Biological Assay; CRISPR/Cas technology; Cancer Etiology; Cells; Cessation of life; ChIP-seq; Chemoresistance; Clustered Regularly Interspaced Short Palindromic Repeats; Colon; Colorectal Adenocarcinoma; Colorectal Cancer; Colorectal Neoplasms; Data; Development; Embryo; Enhancers; Equilibrium; Gene Targeting; Genes; Genetic; Genetic Transcription; Genomics; Growth; Heterogeneity; Homologous Gene; Human; Immunocompromised Host; Knock-out; Light; Malignant - descriptor; Malignant Neoplasms; Measures; Modeling; Molecular; Mucous Membrane; Mus; Nature; Neoplasm Metastasis; Neoplasm Transplantation; Oncogenes; Organoids; Patient-Focused Outcomes; Phenotype; Play; Proliferating; Reporter; Research; Role; Serial Passage; Site; Source; Tamoxifen; Testing; Transplantation; Tumor Suppressor Proteins; Tumorigenicity; cancer biomarkers; cancer cell; cancer initiation; cancer stem cell; colon cancer cell line; colorectal cancer treatment; embryonic stem cell; epigenetic marker; epithelial to mesenchymal transition; experimental study; in vivo; insight; neoplastic cell; new therapeutic target; pluripotency factor; programs; promoter; single-cell RNA sequencing; stem; stem cell therapy; stem cells; stemness; targeted cancer therapy; transcription factor; tumor; tumor growth; tumor initiation; tumorigenesis

Project Summary Colorectal cancer (CRC) is the third leading cause of cancer death worldwide. Cancer stem cells (CSCs) in the colon are the source of tumor initiation, proliferation, chemoresistance, and metastasis, and are therefore considered to adversely impact patient outcome. However, there are no therapies targeting CSCs for treatment of CRC. Pluripotency factors have been proposed to drive stemness in CSCs, but the molecular mechanisms remain unclear. Understanding the molecular regulators that enable stemness and tumorigenicity in CSCs will identify novel therapeutic targets. The role of pluripotency factors is best understood in embryonic stem cells (ESCs), where their interplay has been proposed to drive heterogeneity. We recently identified a potential transcriptional circuit between pluripotency factors Klf4 and Zfp281 that we hypothesize enables ESCs to switch between specific stem cell states and thus generate transcriptional heterogeneity. Notably, in CRC, Klf4 and Zfp281 have also implicated as a tumor suppressor and pro-proliferative agent, respectively. Klf4 inhibits proliferation and expression of Bmi1, an epigenetic marker that we previously identified as required for CRC tumorigenesis, whereas Zfp281 is often co-expressed with Bmi1. Klf4 and Zfp281 display reciprocal expression in both ESCs and CRC cells, but their correlation with stemness is reversed in the two contexts, such that Klf4 is associated with more stem-like ESCs but more differentiated CRC cells. The role of pluripotency factor circuits has not been addressed in CSCs, and the precise interplay between Klf4 and Zfp281 is unknown in either ESCs or CRCs. I hypothesize that during both embryonic and cancer development, Klf4 and Zfp281 oppose each other, forming a genetic circuit that modulates the balance between stemness and differentiation. I further propose that perturbing this genetic circuit will restrict stemness and tumorigenicity. In this proposal, I will investigate how Klf4 and Zfp281 interact and regulate stemness in embryonic and tumor development. Aim 1 will define the interactions of Klf4 and Zfp281 that generate opposing stem cell states in cultured ESCs. Aims 2 and 3 will examine the role, and consequences of perturbation, of Klf4 and Zfp281 in regulating stemness and tumorgenicity of CRC cells. Specifically, Aim 2 will use CRC lines and organoids to determine whether Klf4 and Zfp281 knockout restricts the differentiation capacity and expression of stemness programs in CSCs. Aim 3 will establish the interplay of Klf4 and Zfp281 with each other, and also Bmi1, in CRC and determine how these contribute to tumorgenicity in vivo. This project will establish the role of Klf4 and Zfp281 in stemness and tumorigenicity and the nature of the circuit between them. The molecular and mechanistic insights of this project will further our understanding of how CSCs initiate and grow tumors, as well as identify novel therapeutic targets for CRC treatment.

项目概要 结直肠癌（CRC）是全球第三大癌症死亡原因。癌症干细胞 结肠中的 CSC（CSC）是肿瘤发生、增殖、化疗耐药和转移的根源， 因此被认为会对患者的治疗结果产生不利影响。然而，目前还没有针对 CSC 用于治疗 CRC。已提出多能因子可驱动 CSC 的干性，但 分子机制仍不清楚。了解使干性和 CSC 的致瘤性将确定新的治疗靶点。 多能因子的作用在胚胎干细胞 (ESC) 中得到了最好的理解，它们之间的相互作用 已提出驱动异质性。我们最近发现了一个潜在的转录回路 我们假设多能因子 Klf4 和 Zfp281 使 ESC 能够在特定干细胞之间切换 状态，从而产生转录异质性。值得注意的是，在 CRC 中，Klf4 和 Zfp281 也涉及 分别作为肿瘤抑制剂和促增殖剂。 Klf4 抑制增殖和表达 Bmi1，我们之前确定的 CRC 肿瘤发生所需的表观遗传标记，而 Zfp281 通常与 Bmi1 共表达。 Klf4 和 Zfp281 在 ESC 和 CRC 中显示相反的表达 细胞，但它们与干细胞的相关性在这两种情况下是相反的，因此 Klf4 与更多细胞相关 类似干细胞的 ESC，但分化程度更高的 CRC 细胞。多能因子电路的作用尚未被阐明 在 CSC 中得到解决，而 Klf4 和 Zfp281 之间的精确相互作用在 ESC 或 CRC 中尚不清楚。我 假设在胚胎和癌症发育过程中，Klf4 和 Zfp281 相互对抗， 形成调节干性和分化之间平衡的遗传回路。我进一步 提出扰乱这种遗传回路将限制干性和致瘤性。 在本提案中，我将研究 Klf4 和 Zfp281 如何相互作用并调节胚胎和胚胎干细胞的干性。 肿瘤的发展。目标 1 将定义 Klf4 和 Zfp281 的相互作用，从而产生相反的干细胞 培养的 ESC 中的状态。目标 2 和 3 将研究 Klf4 和 Klf4 的作用和扰动的后果 Zfp281 调节 CRC 细胞的干性和致瘤性。具体来说，目标 2 将使用 CRC 线并且 类器官以确定 Klf4 和 Zfp281 敲除是否限制分化能力和表达 CSC 中的干性计划。 Aim 3 将建立 Klf4 和 Zfp281 之间的相互作用，并且 Bmi1，在 CRC 中并确定它们如何促进体内致瘤性。该项目将建立 Klf4 和 Zfp281 在干性和致瘤性中的作用以及它们之间电路的性质。这 该项目的分子和机制见解将进一步加深我们对 CSC 如何启动和生长的理解 肿瘤，以及确定结直肠癌治疗的新治疗靶点。