Minhas Khalid M, Singh Bhuvanesh, Jiang Wei-Wen, Sidransky David, Califano Joseph A
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD, USA.
Int J Cancer. 2003 Oct 20;107(1):46-52. doi: 10.1002/ijc.11341.
Alterations in chromosomal number and structure are found in most solid malignancies including head and neck squamous cell carcinoma (HNSC), however, the presence of ongoing, chromosomal instability in HNSC and its relation to spindle assembly checkpoint defects has not been formally demonstrated. We investigated the status of chromosomal instability (CIN) in HNSC primary tumors and cell lines as well as spindle assembly checkpoint integrity in HNSC cell lines. Centromeric fluorescence in situ hybridization (FISH) was carried out on expanded single cell-derived colonies from HNSC cell lines and primary HNSC touch preparations. The deviation of chromosomes from the modal number in single cell derived colonies was 18.4-27% in 6 HNSC cell lines, and 2-3% in a control cell line, HCT116. Twelve primary tumors and 4 normal controls were also studied; all primary tumors demonstrated significant deviation from the modal chromosomal number (average 33.7%, range = 29.9-43.9%), compared to normal controls (average 4.6%, range = 3.6-5.6%). Additional characterization of the rate of chromosomal breakage was carried out by dual color FISH simultaneously using centromeric and telomeric probes for individual chromosomes on expanded singe cell-derived colonies and primary HNSC. Control HCT 116 colonies demonstrated a mean discordance between number of centromeric and telomeric hybridization signals in 21% (range = 19-23%) of cells, whereas HNSC cell line colonies demonstrated a mean discordance of 50% (range = 38-55%), with the majority of instances of discordant signal indicating telomeric loss. Similarly, touch preparations from primary HNSC demonstrated discordance in hybridization signal of centromeric vs. telomeric signal of 26.3% (range = 18.5-42%), with normal controls showing a rate of discordance of 6.4% (range = 4-8%). Finally, all 6 HNSC cell lines demonstrated partial impairment of mitotic arrest in response to nocodazole, indicating that impairment of the spindle assembly checkpoint may contribute to chromosomal instability in HNSC. Ongoing instability in chromosomal number and structure are consistent features of primary HNSC and cell lines. Spindle assembly checkpoint impairment occurs in HNSC cell lines and may contribute to chromosomal instability in HNSC.
在包括头颈部鳞状细胞癌（HNSC）在内的大多数实体恶性肿瘤中都发现了染色体数量和结构的改变，然而，HNSC中持续存在的染色体不稳定性及其与纺锤体组装检查点缺陷的关系尚未得到正式证实。我们研究了HNSC原发性肿瘤和细胞系中的染色体不稳定性（CIN）状态以及HNSC细胞系中的纺锤体组装检查点完整性。对来自HNSC细胞系的单细胞衍生集落和原发性HNSC触摸涂片进行了着丝粒荧光原位杂交（FISH）。在6个HNSC细胞系中，单细胞衍生集落中染色体与模式数的偏差为18.4 - 27%，而在对照细胞系HCT116中为2 - 3%。还研究了12个原发性肿瘤和4个正常对照；与正常对照（平均4.6%，范围 = 3.6 - 5.6%）相比，所有原发性肿瘤均显示出与模式染色体数有显著偏差（平均33.7%，范围 = 29.9 - 43.9%）。通过双色FISH对单细胞衍生集落和原发性HNSC中的单个染色体同时使用着丝粒和端粒探针，进一步表征了染色体断裂率。对照HCT 116集落在21%（范围 = 19 - 23%）的细胞中显示着丝粒和端粒杂交信号数量之间的平均不一致性，而HNSC细胞系集落显示平均不一致性为50%（范围 = 38 - 55%），大多数不一致信号的情况表明端粒丢失。同样，原发性HNSC的触摸涂片显示着丝粒与端粒信号杂交信号的不一致率为26.3%（范围 = 18.5 - 42%），正常对照的不一致率为6.4%（范围 = 4 - 8%）。最后，所有6个HNSC细胞系对诺考达唑的有丝分裂阻滞均表现出部分受损，表明纺锤体组装检查点的受损可能导致HNSC中的染色体不稳定。染色体数量和结构的持续不稳定性是原发性HNSC和细胞系的一致特征。纺锤体组装检查点受损发生在HNSC细胞系中，并可能导致HNSC中的染色体不稳定。
