Functional characterization of 2q22.1 deletion in oral squamous cell carcinoma

口腔鳞状细胞癌2q22.1缺失的功能特征

• 批准号: 10669010
• 负责人: Ramin Farhad
• 金额: $ 5.35万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-02 至 2024-09-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10669010
• 关键词: 17p; Affect; Alcohol consumption; Apoptotic; Behavior; Biochemical; Biological Assay; CASP3 gene; CDKN2A gene; CRISPR/Cas technology; Cell Cycle; Cell Line; Cell Separation; Cells; Cervix Uteri; Chromosome Deletion; Clinical; Copy Number Polymorphism; DNA; Data; Development; Disease; Elements; Esophagus; Event; Frequencies; Gene Expression; Genes; Genetic Transcription; Growth; Human; Human Papillomavirus; Immunotherapy; In Vitro; Infection; Intervention; Investigation; LDL-Receptor Related Protein 1; Lung; Maintenance; Malignant Neoplasms; Modality; Molecular Biology Techniques; Mutation; Normal Cell; Operative Surgical Procedures; Oral; Oral cavity; Outcome; Patients; Pattern; Phenotype; Point Mutation; Population; Proliferating; Property; Radiation; Reporting; Sampling; Series; Site; Smoking; Sorting; Squamous Epithelium; Squamous cell carcinoma; TP53 gene; Therapeutic; Tissue-Specific Gene Expression; Tumor Suppression; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tumorigenicity; cancer cell; carcinogenesis; chemotherapy; genomic locus; high risk; in vitro Assay; keratinocyte; malignant mouth neoplasm; mortality; mouth squamous cell carcinoma; novel strategies; novel therapeutics; oral behavior; transcriptome sequencing; tumor; tumorigenic

PROJECT SUMMARY/ABSTRACT Oral squamous cell carcinoma (OSCC) affects approximately 350,000 patients worldwide. The primary causes of OSCC include smoking, consumption of alcoholic beverages, and infections with high-risk human papillomaviruses (HPV). Currently, the main therapeutic modalities offered to patients include surgery, radiation, chemotherapy, and immunotherapy. Despite the existing clinical interventions, the mortality for this disease remains approximately 20% and is greater for higher grade tumors. OSCC tumors are genetically heterogenous with a high rate of point mutations and somatic copy number variations (CNVs). Similar CNV patterns are commonly observed in other squamous cell carcinomas such as those arising from the lung, cervix, and esophagus. The CNVs also have a high propensity for co-occurring with inactivating mutations of tumor suppressor genes. However, despite discoveries documenting the presence of various genomic loci undergoing copy number alterations, the mechanistic contributions of these CNVs to OSCC carcinogenesis have yet to be determined. The early and most frequent genetic alterations in OSCC include loss of tumor suppressors CDKN2A (residing at 9p) in conjunction with mutations in TP53 (residing at 17p). Additionally, one of the most commonly deleted sites within OSCC tumors is located at 2q22.1. This deletion is entirely contained within the low-density lipoprotein receptor-related protein 1B gene, LRP1B, which has been implicated as a tumor suppressor in other cancers but has not been characterized in OSCC. Although deletions at this locus occur more frequently than would be expected by chance, inactivating point mutations within this gene are not common. Moreover, LRP1B is not expressed in oral keratinocytes, raising the question as to why the deletions at this locus occur at such a high frequency, despite the lack of gene expression. This suggests these deletions act by a mechanism that is independent of interfering with LRP1B function. Therefore, I hypothesize that chromosomal deletions at 2q22.1 act as driver events in OSCC progression via alteration of intragenic elements that function in tumor suppression. This proposal will address my hypothesis via three specific aims: 1) Determine the impact of 2q22.1 chromosomal deletions on the tumorigenic behavior of keratinocytes in vitro, 2) Identify mechanisms downstream of 2q22.1 deletion responsible for tumorigenic behavior, and 3) Identify the minimal critical region responsible for the observed phenotypic changes. These aims will be achieved utilizing a combination of biochemical and molecular biology techniques to create the deletions observed in patient samples in wild type keratinocytes and assess their contribution to tumorigenic behavior. Outcomes from this investigation will be used in the development of novel therapeutic applications for suppression of OSCC and potentially various other cancers that originate from the squamous epithelium.

项目摘要/摘要 口服鳞状细胞癌（OSCC）影响了全球约35万名患者。主要原因 OSCC的包括吸烟，含酒精饮料以及具有高风险人类的感染 乳头瘤病毒（HPV）。目前，提供给患者的主要治疗方式包括手术，辐射， 化学疗法和免疫疗法。尽管现有的临床干预措施，但这种疾病的死亡率 保持大约20％，对于高级肿瘤而言更大。 OSCC肿瘤是遗传异质的 点突变率很高和体拷贝数变化（CNV）。类似的CNV模式是 通常在其他鳞状细胞癌中观察到，例如由肺，子宫颈和 食管。 CNV还具有高倾向，可与肿瘤的灭活突变共同出现 抑制基因。然而，尽管有发现存在各种基因组基因局的发现 拷贝数改变，这些CNV对OSCC致癌的机理贡献尚未 决定。 OSCC中早期和最常见的遗传改变包括抑制肿瘤的丧失 CDKN2A（居住在9p）与TP53中的突变（居住在17p）。另外，其中之一 OSCC肿瘤中通常被删除的位点位于2q22.1。此删除完全包含 低密度脂蛋白受体相关蛋白1B基因LRP1B，该基因已与肿瘤有关 其他癌症中的抑制剂，但尚未在OSCC中进行表征。虽然在此删除了 比偶然预期的要多的频率，该基因内的灭活点突变并不常见。 此外，LRP1b在口服角质形成细胞中没有表达 尽管缺乏基因表达，但仍以如此高的频率发生。这表明这些删除行为 独立于干扰LRP1B功能的机制。因此，我假设染色体 2q22.1的删除通过改变基因内元素的驱动程序事件 抑制肿瘤的功能。该建议将通过三个特定目的解决我的假设：1）确定 2q22.1染色体缺失对角质形成细胞的致瘤行为的影响，2）确定 2q22.1删除负责肿瘤行为的机制，3）确定最小的 关键区域负责观察到的表型变化。这些目标将通过 生化和分子生物学技术的组合，以创建在患者样品中观察到的缺失 在野生型角质形成细胞中，并评估其对肿瘤行为的贡献。这项调查的结果 将用于开发新的治疗应用，以抑制OSCC及其潜在的各种 其他起源于鳞状上皮的癌症。