A 700-kb physical and transcription map of the cervical cancer tumor suppressor gene locus on chromosome 11q13.
A 700-kb physical and transcription map of the cervical cancer tumor suppressor gene locus on chromosome 11q13.
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DOI：
10.1016/j.ygeno.2005.02.014
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发表时间：
2005-06
期刊：
影响因子：
4.4
通讯作者：
K. Zainabadi;Payam Benyamini;R. Chakrabarti;M. Veena;S. Chandrasekharappa;R. Gatti;E. Srivatsan
中科院分区：
文献类型：
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作者：
K. Zainabadi;Payam Benyamini;R. Chakrabarti;M. Veena;S. Chandrasekharappa;R. Gatti;E. Srivatsan
染色体11q13序列的非随机缺失在许多人类肿瘤中是一个重要的事件。我们最近在原发性宫颈肿瘤中发现了一个300 kb的最小缺失区域，与内分泌和鼻咽肿瘤中观察到的缺失重叠。我们还在HeLa细胞（一种宫颈癌细胞系）、HeLa细胞衍生的致瘤性杂交细胞和原发性宫颈肿瘤中观察到5.7 kb的纯合缺失，表明该区域存在肿瘤抑制基因。在本研究中，我们利用人类基因组序列数据库构建了包含300 kb缺失的700 kb的序列图，并使用来自该地区的各种STS标记对该图谱进行了验证。我们的图谱还显示了先前发表的罕见的、可遗传的脆性位点FRA11A与宫颈癌缺失位点的重叠。映射区域包含高度重复的GC-poor序列。我们已经从缺失的内部和周围的序列中鉴定并表征了8种不同的多态微卫星标记。此外，对位于纯合缺失位点附近的18种不同ESTs进行的表达研究显示，只有其中一种ESTs的转录本AA282789存在。纯合缺失中的EST定位也在HeLa细胞中表达，从而排除了EST作为假定的肿瘤抑制基因的可能性。此外，对来自该区域的四个候选基因（SF3B2、BRMS1、RIN1和RAB1B）的分析显示，在非致瘤性和致瘤性HeLa细胞杂种中都表达了预期的大小信息，从而排除了它们作为推定的肿瘤抑制基因的可能性。然而，利用定位于缺失/FRA11A重叠区域的第五个候选基因PACS1（磷酸氟酸簇分选蛋白）进行Northern blot分析显示，除了预期的4.5 kb转录物外，HeLa和其他五种肿瘤细胞系中还表达了8 kb的转录物。由于该基因在正常组织中大量表达，而在肿瘤细胞系中观察到转录改变，我们假设该基因可能代表假定的肿瘤抑制基因序列。最后，我们在与神经退行性疾病脊髓小脑性共济失调相关的标记物D11S913近端观察到一个完美的48 bp CAG/CCG重复序列。11q13染色体700-kb区域的物理图谱、转录图谱和微卫星标记将有助于宫颈癌抑癌基因的克隆。
Nonrandom deletion of chromosome 11q13 sequences is a significant event in a number of human tumors. We have recently identified a 300-kb minimal area of deletion in primary cervical tumors that overlaps with deletions observed in endocrine and nasopharyngeal tumors. We have also observed a 5.7-kb homozygous deletion within this interval in HeLa cells (a cervical cancer cell line), HeLa cell-derived tumorigenic hybrids, and a primary cervical tumor, suggesting the presence of a tumor suppressor gene in this region. In the present investigation, we have constructed a 700-kb contig map encompassing the 300-kb deletion using the human genome sequence database and confirmed the map using various STS markers from the region. Our map also shows the overlap of a previously published rare, heritable fragile site, FRA11A, with the cervical cancer deletion locus. The mapped region contains highly repetitive GC-poor sequences. We have identified and characterized eight different polymorphic microsatellite markers from the sequences within and surrounding the deletion. Further, expression studies performed with 18 different ESTs localized adjacent to the homozygous deletion showed the presence of a transcript for only one of the ESTs, AA282789. This EST mapping within the homozygous deletion is also expressed in HeLa cells, thereby excluding the EST as the putative tumor suppressor gene. Additionally, analysis of four candidate genes (SF3B2, BRMS1, RIN1, and RAB1B) from the region showed expression of the expected size message in both the nontumorigenic and the tumorigenic HeLa cell hybrids, thereby excluding them as the putative tumor suppressor gene(s). However, Northern blot analysis with a fifth candidate gene, PACS1 (phosphofurin acidic cluster sorting protein), mapped to the deletion/FRA11A overlap region showed the expression of an 8-kb transcript in HeLa and five other tumor cell lines in addition to the expected 4.5-kb transcript. Since the gene shows abundant expression in normal tissues and an altered transcript is observed in tumor cell lines, we hypothesize that this gene could represent sequences of the putative tumor suppressor gene. Finally, we have observed a perfect 48-bp CAG/CCG repeat 99 kb proximal to D11S913, the marker linked to the neurodegenerative disorder spinocerebellar ataxia 5. The physical and transcription maps and the microsatellite markers of the 700-kb region of chromosome 11q13 should be helpful in the cloning of the cervical cancer tumor suppressor gene.