HYPOXIA AND GENE EXPRESSION IN HUMAN TUMORS

人类肿瘤中的缺氧和基因表达

• 批准号: 6287363
• 负责人: JAMES ARTHUR RALEIGH
• 金额: $ 24.13万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6287363
• 关键词: BCL2 gene /protein; apoptosis; complementary DNA; gene expression; human tissue; hypoxia; in situ hybridization; keratin; metallothionein; microarray technology; neoplasm /cancer genetics; neoplastic growth; proliferating cell nuclear antigen; squamous cell carcinoma

Human cancers vary markedly from patient to patient with respect to growth, aggressiveness and response to radiation therapy, chemotherapy and surgery. This might be due to the effect that microenvironmental factors such as hypoxia has on the expression of oncogenes, cytokines and angiogenic factors. This has led to a number of oxygen regulated protein expression in tumor cell lines in vitro and in vivo. However, the results do not adequately account for the expression of oxygen regulated proteins (ORPs) such as vascular endothelial growth factor and metallothionein (MT) in human squamous cell carcinomas in clinical studies. Evidence is presented here that hypoxic cells in squamous cell carcinomas (SCCs) exhibit signs of terminal differentiation and it is hypothesized that genetic controls associated with terminal differentiation exert collateral control on the expression of oxygen regulated genes. The hypothesis will be tested in both specific and general ways. A specific test will use in situ hybridization analysis of MT mRNA isoform expression which changes from inducible MT-I mRNA to non-inducible MT-IV mRNA during epithelial cell differentiation. It is predicted that hMT-IV mRNA will be expressed in hypoxic cells of SCCs thereby accounting for the general lack of MTI(II) protein expression in these cells. A general test of the hypothesis will use powerful new DNA array technology. Gene expression for oxygen regulated proteins and energy metabolism, among others, will be compared in hypoxic and oxic regions of SCCs that have been microdissected from tissue sections. It is predicted that hypoxic cells in regions of terminal differentiation in SCCs will not express the ORP genes that are observed in hypoxic tumor cell lines in vitro. Pimonidazole binding will be used to identify regions of hypoxia; proliferating cell nuclear antigen (PCNA) will be used to locate regions of proliferation; and, involucrin will be used to identify regions of terminal differentiation in SCC tissue sections. While of interest to all cancer therapies, it is believed that the results of this study will be of particular relevance to conventional radiation therapy and radiation therapies that include adjuvants designed to deal with tumor hypoxia.

人类癌症在生长、侵袭性和对放射疗法、化学疗法和手术的反应方面因患者而异。这可能是由于微环境因素如缺氧对癌基因、细胞因子和血管生成因子表达的影响。这导致了许多氧调节蛋白在体外和体内肿瘤细胞系中的表达。然而，在临床研究中，这些结果并不能充分解释人类鳞状细胞癌中氧调节蛋白（ORP）如血管内皮生长因子和金属硫蛋白（MT）的表达。这里提出的证据表明，在鳞状细胞癌（SCC）的缺氧细胞表现出终末分化的迹象，它是假设，与终末分化相关的遗传控制施加并行控制的氧调节基因的表达。该假设将以具体和一般的方式进行检验。一项特异性试验将使用MT mRNA同种型表达的原位杂交分析，其在上皮细胞分化期间从诱导型MT-I mRNA变为非诱导型MT-IV mRNA。据预测，hMT-IV mRNA将在SCC的缺氧细胞中表达，从而解释了这些细胞中MTI（II）蛋白表达的普遍缺乏。对这一假设的一般性检验将使用强大的新DNA阵列技术。氧调节蛋白和能量代谢的基因表达，除其他外，将比较在低氧和有氧地区的SCC已显微解剖的组织切片。据预测，SCC中终末分化区域中的缺氧细胞将不表达在体外缺氧肿瘤细胞系中观察到的ORP基因。匹莫硝唑结合将用于识别缺氧区域;增殖细胞核抗原（PCNA）将用于定位增殖区域;并且，外皮蛋白将用于识别SCC组织切片中的终末分化区域。虽然对所有癌症疗法都感兴趣，但据信本研究的结果将与常规放射疗法和包括设计用于处理肿瘤缺氧的佐剂的放射疗法特别相关。