肝癌转移抑制基因在8号染色体上的功能定位

Functional localization of metastasis suppressor genes for HCC on human chromosome 8

目的为进一步寻找和克隆可能的肝癌转移抑制基因奠定基础。方法以序列标签位点（STS）为路标，运用基因组物理图谱方法分析人类染色体8p上肝癌转移抑制基因相关染色体缺失状况，从NCBI的UniSTS数据库查询STS的引物序列，以微细胞杂交克隆DNA为模板（A9／C5F1和A9／C5F2为转移不抑制组，A9／C5F4、A9／C5F8和A9／C5F10为转移抑制组）进行STSPCR扩增。结果人类染色体8p上从D8S542位点起至D8S1973位点区段（位于染色体8p21．1～23．1区域，约18cM）存在转移抑制组杂交克隆STS位点不同程度的获得和转移不抑制组杂交克隆组STS位点的缺失。结论D8S542～D8S1973所在的人类染色体8p21．1～23．1区域可能存在肝癌转移抑制基因。

Objective We previously showed that introduction of a normal, neomycin-tagged human chromosome 8 reduced the metastatic capacity of C5F rat liver cancer cell line, which had high metastatic potential without affecting tumorigenicity, suggesting the presence of one or more metastasis suppressor genes encoded on human chromosome 8. We proceeded to define further the region harboring the metastasis suppressor gene（s） and to determine the random loss of human chromosome 8 by PCR amplification of sequence tag site （STS） markers. Methods The national Center for Biotechnology Information （NCBI） databases were used as references of the relative genetic distances of the STS markers. C5F genomic DNA and A9/neo8 genomic DNA were used as negative and positive controls for chromosome 8 amplification, respectively. Genomic DNA was isolated and quantified from cultured hybrid clones （A9/C5F-1 and A9/C5F- 2 microcell hybrid clones served as metastasis-unsuppressed groups; A9/C5F-4, A9/C5F-8 and A9/C5F-10 microcell hybrid clones served as metastasis suppressed groups）. STS-PCR products were separated by electrophoresis through 2% agarose gel. Results Metastasis-suppressed microcell hybrid clones （A9/C5F-4, A9/ C5F-8 and A9/C5F-10） conserved STS markers between D8S542 - D8S1973 （8p21.1-23.1）. In contrast, metastasis-unsuppressed clones （A9/C5F- 1 and A9/C5F-2） lacked several markers in this region. In attempts to refine the region retained in the microcell suppressed clones, more densely spaced STS markers in the human chromosome 8p21.1-23.1 were used. We found that the metastasis-suppressed clones retained 18cM region between D8S542 and D8S 1973 （8P21.1-23.1）, where as the metastasis-unsuppressed clones lacked the region. Conclusion Our results suggest that a metastasis suppressor gene is located within the interval between D8S542 and D8S 1973 on human chromosome 8p21.1-23.1.