Targeting cholesterol metabolism and replication stress response in cancer therapy

癌症治疗中针对胆固醇代谢和复制应激反应

• 批准号: 10548830
• 负责人: Junran Zhang
• 金额: $ 34.97万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10548830
• 关键词: ATM function; Address; Affect; Antifungal Agents; Biological; Biological Assay; CHEK1 gene; CRISPR/Cas technology; Ca(2+)-Calmodulin Dependent Protein Kinase; Cancer Etiology; Cancer Patient; Cell Death; Cell Line; Cell Survival; Cells; Cessation of life; Cholesterol; Cholesterol Homeostasis; Clinical; Clinical Trials; Complex; Cytogenetics; DNA; DNA Damage; DNA Repair; DNA Repair Disorder; DNA biosynthesis; DNA replication fork; Data; Defect; Disease; Drug Targeting; Endoplasmic Reticulum; Enzymes; Event; FDA approved; Fiber; Fura-2; Goals; Human; Immunotherapy; Impairment; In Vitro; Interruption; Lead; Malignant Neoplasms; Malignant neoplasm of lung; Mediating; Movement; Non-Small-Cell Lung Carcinoma; Oncogenic; Pathway interactions; Phosphoric Monoester Hydrolases; Phosphotransferases; Prognosis; Proteins; Reporter; Reporting; Role; Signal Transduction; Squalene; Techniques; Testing; Woman; anticancer research; antitumor effect; ataxia telangiectasia mutated protein; biological adaptation to stress; cancer cell; cancer diagnosis; cancer therapy; cell growth; cholesterol biosynthesis; cholesterol control; efficacy evaluation; endoplasmic reticulum stress; epoxidase; genome-wide; homologous recombination; improved; in vitro Assay; inhibitor; innovation; knock-down; live cell imaging; loss of function; lung cancer cell; men; mouse model; multimodality; neoplastic cell; novel; novel strategies; novel therapeutic intervention; overexpression; patient derived xenograft model; pharmacologic; prevent; protein expression; ratiometric; repaired; replication stress; response; screening; small hairpin RNA; synergism; synthetic lethal interaction; targeted treatment; therapy resistant; treatment strategy; tumor growth

Project Summary: Lung cancer is the leading cause of cancer deaths in both men and women. Non-small cell lung cancer (NSCLC) accounts for large majority of lung cancer diagnoses, and novel treatment strategies for this disease are urgently needed. ATR and its downstream effector CHK1 are key component of replication stress (RS) response that specifically deal with the stalled replication forks during DNA replication and are critical for cell survival under RS. Inhibitors targeting ATR and CHK1 are currently being tested in clinical trials. However, only limited efficacy has been observed when those agents are combined with standard therapy. Identifying the new synergistic conditions that render cells sensitive to ATR/CHK1 inhibitors will be key to improving the efficacy of these agents. Squalene epoxidase (SQLE), an enzyme controlling cholesterol biosynthesis by converting squalene to oxidosqualene in endoplasmic reticulum (ER), is frequently overexpressed in human cancers, including lung cancer. High expression of SQLE is associated with poor prognosis. Our recent genome-wide loss of function screen discovered that SQLE reduction led to enhanced sensitivity to a CHK1 inhibitor. Thus, the goal of this application is to determine whether SQLE inhibition sensitizes NSCLC cells to ATR and CHK1 inhibitors and whether high SQLE-expressing NSCLC cancer can be specifically targeted by the combined inhibition of SQLE and ATR/CHK1. Our preliminary data suggest that SQLE inhibition by shRNA knockdown causes RS and activates ATR/CHK1 activation. In addition, SQLE inhibition lead to increased protein expression of WIP1, a phosphatase that suppress the activity of ATM, a master DNA damage response protein controlling DNA repair. We hypothesize that SQLE inhibition leads to increased RS by suppressing DNA repair, rendering cells sensitive to ATR and CHK1 inhibition. Thus, co-administration of an SQLE inhibitor and an ATR or CHK1 inhibitor could synergistically suppress tumor growth. To test our hypothesis, three Specific Aims are proposed. Specific Aim 1 will interrogate the mechanism by which SQLE inhibition leads to increased WIP1 expression. Specific Aim 2 will determine whether SQLE inhibition leads to increased RS by impairing DNA repair, particularly homologous recombination, a major repair pathway that prevents and antagonizes RS. Specific Aim 3 will assess the efficacy of combined SQLE inhibition and ATR/CHK1 inhibition in suppressing tumor cell growth using in vitro assays as well as cell line-based and patient-derived xenograft (PDX) models of NSCLC. If successful, our studies will reveal a new synthetic lethal interaction between inhibition of SQLE and ATR/CHK1 and will have a significant impact on improving the survival of lung cancer patients by identifying novel therapeutic approaches.

项目概要： 肺癌是男性和女性癌症死亡的主要原因。非小细胞肺癌（NSCLC） 占肺癌诊断的绝大多数，并且迫切需要针对这种疾病的新治疗策略。 needed. ATR及其下游效应物CHK 1是复制应激（RS）反应的关键组分， 专门处理DNA复制过程中停滞的复制叉，对细胞在 卢比靶向ATR和CHK 1的抑制剂目前正在临床试验中进行测试。然而，只有有限的功效 当这些药物与标准疗法联合使用时，确定新的协同增效措施 使细胞对ATR/CHK 1抑制剂敏感的条件将是改善这些药剂功效的关键。 角鲨烯环氧酶（SQLE），一种通过将角鲨烯转化为胆固醇来控制胆固醇生物合成的酶。 内质网（ER）中的氧化角鲨烯经常在人类癌症（包括肺癌）中过表达。 癌SQLE高表达与预后不良相关。我们最近的基因组功能丧失 筛选发现SQLE减少导致对CHK 1抑制剂的敏感性增强。因此， 本申请的目的是确定SQLE抑制是否使NSCLC细胞对ATR和CHK 1抑制剂敏感， 高SQLE表达的NSCLC癌症是否可以通过SQLE的联合抑制而特异性靶向 ATR/CHK1。我们的初步数据表明，通过shRNA敲低抑制SQLE导致RS， 激活ATR/CHK 1激活。此外，SQLE抑制导致WIP 1蛋白表达增加， 它抑制ATM的活性，ATM是一种控制DNA修复的主要DNA损伤反应蛋白。 我们假设SQLE抑制通过抑制DNA修复导致RS增加，使细胞敏感 ATR和CHK 1抑制。因此，SQLE抑制剂和ATR或CHK 1抑制剂的共同给药可 协同抑制肿瘤生长。为了验证我们的假设，提出了三个具体目标。具体目标1 将询问SQLE抑制导致WIP 1表达增加的机制。具体目标2将 确定SQLE抑制是否通过损害DNA修复，特别是同源修复， 重组，一个主要的修复途径，防止和拮抗RS。具体目标3将评估疗效 使用体外测定， 以及基于细胞系和患者来源的NSCLC异种移植（PDX）模型。如果成功，我们的研究将 揭示了抑制SQLE和ATR/CHK 1之间的新的合成致死相互作用，并将具有显著的 通过确定新的治疗方法对提高肺癌患者生存率的影响。