Oncogenic Kras drives stromal adipogenesis to promote colorectal cancer (CRC) progression

致癌 Kras 驱动基质脂肪生成，促进结直肠癌 (CRC) 进展

• 批准号: 10670996
• 负责人: Wen-Hao Hsu
• 金额: $ 4.16万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2023-11-08
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10670996
• 关键词: Address; Adipocytes; Alleles; Automobile Driving; Biological; Biological Assay; Bypass; CXCL3 gene; Cancer Model; Carcinoma; Catalogs; Cell Culture Techniques; Cell Cycle Progression; Cell Line; Cells; Chromosomal Instability; Clinic; Coculture Techniques; Colorectal Cancer; Cytokine Gene; DNA Sequence Alteration; Data; Data Set; Development; Diagnosis; Disease; Disease Progression; Drops; Embryo; Engineering; Event; Fibroblasts; Functional disorder; Gene Expression; Gene set enrichment analysis; Genes; Genetic; Genomic Instability; Genomics; Goals; Histologic; Human; Human Engineering; Immune; Impairment; KRAS oncogenesis; KRAS2 gene; KRASG12D; Lipids; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mediating; Metastatic Neoplasm to the Bone; Minority; Modeling; Molecular; Mus; Mutation; Myelogenous; Myeloid-derived suppressor cells; Nature; Neoplasm Metastasis; Oncogenes; Oncogenic; Outcome; Pathway interactions; Patients; Phase; Phenotype; Postdoctoral Fellow; Proliferating; Public Health; RNA-Directed DNA Polymerase; Recurrence; Reporter; Research; Research Project Grants; Role; Signal Transduction; Stromal Cells; Surveys; Survival Rate; TP53 gene; Telomerase; The Cancer Genome Atlas; Training; Transforming Growth Factor beta; Transgenes; Tumor Biology; Tumor Immunity; Tumor Promotion; Work; advanced disease; angiogenesis; cancer cell; cell type; colon cancer patients; colorectal cancer metastasis; colorectal cancer progression; conditional knockout; cytokine; design; genomic aberrations; in silico; in vivo; lipid biosynthesis; lymph nodes; metastatic colorectal; metastatic process; mouse model; new therapeutic target; novel; prevent; promoter; prostate cancer model; recruit; single-cell RNA sequencing; targeted treatment; telomere; therapeutic target; trait; transcription factor; tumor; tumor microenvironment; tumor progression; tumorigenesis

Project Summary While the 5-year survival rate for colorectal cancer (CRC) patients with localized stage disease (as defined by SEER) is 90%, this survival rate drops to 14% for patients diagnosed with metastatic CRC. Thus, there is an urgent need to define the mechanisms governing progression to advanced disease and its maintenance. Human CRCs harboring oncogenic mutations in the KRAS oncogene (designated hereafter as KRAS*) are 25% more likely to develop metastases. Similarly, our CRC mouse model, engineered with an inducible KRAS* transgene and conditional null alleles of APC and p53 alleles (iKAP), has revealed a role for KRAS* in driving cancer progression and metastasis. Mechanistically, KRAS*-driven cancer metastasis functions in part by activating cancer cell-intrinsic TGFβ signaling and suppressing anti-tumoral immunity via the IRF2-CXCL3 axis which recruits myeloid derived suppressor cells. Unfortunately, emerging therapies targeting either KRAS* or TGFβ pathways have shown limited efficacy in the clinic, motivating us to identify and validate additional KRAS*-driven cancer progression mechanisms with the goal of expanding the repertoire of therapeutic targets for metastatic CRC. Utilizing the iKAP model, functional gene set enrichment and histological analyses of KRAS*-expressing CRC metastases revealed a strong adipogenesis signature and preponderance of lipofibroblasts and angiogenesis in the tumor microenvironment. Correspondingly, co-culture of mouse embryonic fibroblasts with conditioned media from iKAP primary cell lines stimulated their differentiation into cells with adipocyte and fibroblast traits, i.e., “lipofibroblasts.” In the F99 phase of this proposal, I seek to define the molecular mechanisms by which KRAS*-expressing cancer cells drive lipofibrogenesis and to understand the tumor biological role of lipofibroblasts in KRAS*-driven CRC progression. As only a minority of human or mouse KRAS* CRC cases progress to metastatic disease, clearly genetic events beyond KRAS activation drive metastases. For example, patients with or without KRAS* mutation both show around a 40% lymph node metastatic rate. The study of such pro-metastasis events would be greatly facilitated by incorporating an inducible telomerase reverse transcriptase (LSL-mTERT) into our existing iAP model, thus modeling telomere-based crisis and genome instability followed by telomerase reactivation. In our telomerase-inducible mouse models of prostate cancer, crisis-telomerase sequence generates cancer-relevant genomic aberrations and increases metastatic potential. Although incorporation of genomic instability into the iAP model would not create a more human-like model, it would provide a platform to identify amplifications and deletions associated with the metastatic process. In the K00 phase of this proposal, I seek to engineer human- like telomere dynamics in the iAP model to assess the impact of telomere-based crisis and telomerase reactivation in driving metastasis and to survey the genomic alterations that may underlie the metastatic process. Such efforts may facilitate the discovery of new therapeutic targets for advanced CRC disease.

项目摘要 而具有局限期疾病的结直肠癌(CRC)患者的5年存活率(定义为 SEER)为90%时，转移性结直肠癌患者的存活率降至14%。因此，有一个 迫切需要确定进展为晚期疾病及其维持的机制。 在KRAS癌基因(以下称为KRAS*)中存在致癌突变的人CRC是 发生转移的可能性增加25%。同样，我们的CRC小鼠模型，设计了可诱导的KRAS* APC和p53等位基因的转基因和条件性零等位基因(IKAP)揭示了KRAS*在驱动中的作用 癌症的进展和转移。从机制上讲，KRAS*驱动的癌症转移功能部分是通过 通过IRF2-CXCL3轴激活癌细胞内源性转化生长因子β信号抑制抗肿瘤免疫 它招募髓系来源的抑制细胞。不幸的是，针对KRAS*或 转化生长因子β通路在临床上显示的疗效有限，这促使我们识别和验证其他 KRAS*驱动的癌症进展机制，目标是扩大治疗靶点的保留范围 用于转移性结直肠癌。利用IKAP模型，功能基因集丰富和组织学分析 表达KRAS*的结直肠癌转移瘤显示出强烈的成脂特征和优势 肿瘤微环境中的脂成纤维细胞与血管生成。相应地，小鼠的共培养 来自IKAP原代细胞系的条件培养液刺激胚胎成纤维细胞分化为 具有脂肪细胞和成纤维细胞特性的细胞，即“脂成纤维细胞”。在这项提案的F99阶段，我试图定义 表达KRAS*的癌细胞驱动脂肪纤维化的分子机制及了解 脂成纤维细胞在KRAS*驱动的结直肠癌进展中的肿瘤生物学作用。 由于只有少数人或小鼠KRAS*CRC病例进展为转移性疾病，显然是遗传的 KRAS激活以外的事件会导致转移。例如，带有或不带有KRAS*突变的患者 显示约40%的淋巴结转移率。对这种促转移事件的研究将会有很大的意义 通过将可诱导端粒酶逆转录酶(LSL-mTERT)整合到我们现有的IAP中来促进 模型，从而模拟基于端粒的危机和基因组不稳定，随后端粒酶重新激活。在我们的 端粒酶诱导的前列腺癌小鼠模型，危机-端粒酶序列产生癌症相关 基因组异常并增加转移潜能。尽管将基因组不稳定性纳入到 IAP模型不会创建一个更接近人类的模型，它将提供一个平台来识别扩增和 与转移过程相关的缺失。在这项提案的K00阶段，我寻求设计人类- 如IAP模型中的端粒动力学评估基于端粒的危机和端粒酶的影响 重新激活在驱动转移中的作用，并调查可能在转移过程中潜在的基因组变化。 这些努力可能有助于发现晚期结直肠癌的新治疗靶点。