Molecular Genetics of Prostate Cancer

前列腺癌的分子遗传学

• 批准号: 6558695
• 负责人: William Marston Linehan
• 金额: --
• 依托单位: DIVISION OF CLINICAL SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6558695
• 关键词: biopsy; carcinogenesis; cell line; cellular oncology; chromosome deletion; clinical research; dissection; genetic library; genetic mapping; genetic markers; human genetic material tag; human subject; lasers; male; metastasis; molecular oncology; neoplasm /cancer genetics; neoplastic process; nucleic acid sequence; prostate neoplasms; prostate surgery

In order to investigate the genetic events associated with the initiation and progression of prostate cancer, scientists from the Urologic Oncology Branch (UOB) and the Laboratory of Pathology (LOP) at the NCI have made use of a number of innovative methodologies centered around the procurement of highly purified prostatic cancer cells from heterogeneous tissue. Novel microdissection techniques which allow such procurement were developed in the LOP; the most recent such technique involving laser capture of cells greatly increased the speed and purity of dissection.Chromosomal deletions are often found in the vicinity of genes that protect cells from becoming cancerous. Using DNA prepared from 99 microdissected tumors, scientists in the UOB analyzed 45 genetic markers spanning a number of chromosomal regions that had been previously implicated in prostate carcinogenesis. The highest rate of deletion was observed on human chromosome 8, where the overall rate of loss was 86%. Approximately 80% of the cancers shared a common region of deletion within chromosome 8 (8p21). This region also overlaps a region recently identified as a locus for familial breast cancer.Human prostate cancer is thought to progress through a pre-malignant phase called prostatic intraepithelial neoplasia (PIN) prior to evolving into invasive cancer. In the region of chromosome 8 commonly deleted in cancer, deletions were also found in 63% of PIN lesions. This result suggests that abnormalities on 8p21 may be associated with early stages of prostate cancer development.A physical map of the region is currently being constructed in the UOB, and the UOB and LOP teams have begun analyzing candidate genes which reside in this area.Scientists in the LOP found that microdissected prostate samples also yielded good quality RNA, which has allowed them and the UOB team to analyze differences in gene expression in normal vs. tumor tissue. In addition to looking directly for expression of various genes in specific cell populations, libraries containing expressed genetic sequences were constructed as part of the multidisciplinary Cancer Genome Anatomy Project (CGAP). Twenty prostate libraries were constructed covering a spectrum of biology from normal to pre-malignant to localized and metastatic cancer. These libraries were sequenced at the Genome Sequencing Center at Washington University and found to exhibit high quality representation of both known and heretofore undiscovered genes. Data from large scale library sequencing allows for identification and comparison of genes expressed at distinct stages of tumor progression. The information generated is being used to guide the selection of candidate genes which map to 8p21.Finally, in order to expand upon the available resources for examination of prostate cancer in living cells, cell lines were established by scientists from the UOB and the Surgery Branch. The lines were generated from tissue from nine patients who underwent radical prostatectomy and four patients with advanced prostate cancer who underwent biopsy at the NCI. These lines will allow for future in vitro growth studies.

为了研究与前列腺癌发生和进展相关的遗传事件，NCI 泌尿肿瘤科 (UOB) 和病理学实验室 (LOP) 的科学家利用了许多围绕采购的创新方法。来自异质组织的高度纯化的前列腺癌细胞。 LOP 开发了允许此类采购的新型显微切割技术；最近的此类技术涉及激光捕获细胞，大大提高了解剖的速度和纯度。染色体缺失经常发现在保护细胞免于癌变的基因附近。 UOB 的科学家利用从 99 个显微解剖肿瘤中制备的 DNA，分析了跨越多个染色体区域的 45 个遗传标记，这些区域先前与前列腺癌发生有关。人类8号染色体的缺失率最高，总体缺失率为86%。大约 80% 的癌症在 8 号染色体 (8p21) 内有一个共同的缺失区域。该区域也与最近被确定为家族性乳腺癌位点的区域重叠。人类前列腺癌被认为在演变成浸润性癌症之前会经历一个称为前列腺上皮内瘤变 (PIN) 的癌前阶段。在癌症中常见缺失的 8 号染色体区域中，63% 的 PIN 病变中也发现了缺失。这一结果表明，8p21 的异常可能与前列腺癌发展的早期阶段有关。UOB 目前正在构建该区域的物理图谱，UOB 和 LOP 团队已开始分析该区域的候选基因。 LOP 发现显微解剖的前列腺样本也产生了高质量的 RNA，这使得他们和 UOB 团队能够分析正常组织与肿瘤组织中基因表达的差异。除了直接寻找特定细胞群中各种基因的表达之外，还构建了包含表达基因序列的文库，作为多学科癌症基因组解剖计划（CGAP）的一部分。构建了二十个前列腺文库，涵盖从正常癌到癌前癌到局部癌和转移性癌的生物学谱系。这些文库在华盛顿大学基因组测序中心进行了测序，发现它们表现出已知和迄今未发现的基因的高质量代表性。来自大规模文库测序的数据可以识别和比较在肿瘤进展的不同阶段表达的基因。生成的信息用于指导映射到 8p21 的候选基因的选择。最后，为了扩展活细胞中前列腺癌检查的可用资源，来自 UOB 和外科部门的科学家建立了细胞系。这些细胞系是从 9 名接受根治性前列腺切除术的患者和 4 名在 NCI 接受活检的晚期前列腺癌患者的组织中生成的。这些生产线将允许未来的体外生长研究。