Polycomb group molecule PHC3 regulates polycomb complex composition and prognosis of osteosarcoma
Polycomb group molecule PHC3 regulates polycomb complex composition and prognosis of osteosarcoma
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DOI：
10.1111/j.1349-7006.2010.01586.x
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发表时间：
2010-07-01
期刊：
影响因子：
5.7
通讯作者：
Kamijo, Takehiko
中科院分区：
文献类型：
--
作者：
Iwata, Shintaro;Takenobu, Hisanori;Kamijo, Takehiko
多同源异型同源物 3 (PHC 3) 是人类多梳复合物的成员，被认为是骨肉瘤的候选肿瘤抑制因子。在本文中，我们使用 10 个骨肉瘤细胞系和 42 个原发性骨肉瘤样本，通过定量实时 PCR 进行了突变调查和 PHC3 表达分析。将临床样本的相对 PHC3 表达值与临床结果进行分析，表明 PHC3 表达较低的患者总体生存率显着较差。临床样本的PHC3相对值低于正常骨组织，而高于细胞系。通过变性高效液相色谱分析和直接测序，我们在U2OS细胞中发现了PHC3错义突变，导致精氨酸56被脯氨酸取代。 42 个原发性骨肉瘤样本中有 4 个存在相同的点突变。在功能分析方面，PHC3的表达显着抑制了肿瘤细胞的集落形成。有趣的是，多梳抑制复合体 1 成员 Bmi1 和 Ring1b 蛋白在表达 PHC3 的骨肉瘤细胞中减少。缺失突变体PHC3表达表明PHC3的羧基末端具有抑制作用；上述PHC3的点突变也失去了抑制活性。相反，Bmi1表达在mRNA水平上降低PHC3并诱导骨肉瘤细胞增殖。综上所述，我们证实了PHC3在骨肉瘤细胞中作为肿瘤抑制因子的作用，并发现PHC3依赖性肿瘤抑制可能是通过改变癌细胞中多梳抑制复合物1的组成而引起的。 （癌症科学 2010）。
Polyhomeotic homolog 3 (PHC 3) is a member of the human polycomb complex and has been regarded as a candidate tumor suppressor of osteosarcoma. In the present paper, we performed a mutation survey and PHC3 expression analysis by quantitative real-time PCR using 10 osteosarcoma cell lines and 42 primary osteosarcoma samples. Relative PHC3 expression values of clinical samples were analyzed with clinical outcomes, and it was suggested that lower PHC3-expressing patients had significantly worse overall survival. Relative PHC3 values of clinical samples were less than those of normal bone tissues, whereas they were greater than those of cell lines. By denaturing high performance liquid chromatography analysis and direct sequencing, we found a PHC3 missense mutation in U2OS cells, which resulted in arginine56 to proline substitution. The same point mutation existed in four of 42 primary osteosarcoma samples. Regarding functional analysis, PHC3 expression significantly suppressed the colony formation of tumor cells. Intriguingly, polycomb repressive complex 1 members, Bmi1 and Ring1b proteins, were reduced in PHC3-expressing osteosarcoma cells. Deletion mutant PHC3 expression suggested that the carboxyl terminus of PHC3 has a role in suppression; the above-mentioned point mutation of PHC3 also lost inhibitory activities. Conversely, Bmi1 expression reduced PHC3 at the mRNA level and induced the proliferation of osteosarcoma cells. Taken together, we confirmed the role of PHC3 as a tumor suppressor in osteosarcoma cells and found that PHC3-dependent tumor suppression may be caused by modification of the composition of polycomb repressive complex 1 in cancer cells. (Cancer Sci 2010).