Imai Misa, Muraki Miho, Takamatsu Kiyoshi, Saito Hidekazu, Seiki Motoharu, Takahashi Yuji
Division of Reproductive Medicine, Department of Perinatal Medicine and Maternal Care, National Center for Child Health and Development, Tokyo 157-8535, Japan.
BMC Cancer. 2008 Nov 4;8:319. doi: 10.1186/1471-2407-8-319.
Granulosa cell tumours (GCTs) are frequently seen in menopausal women and are relatively indolent. Although the physiological properties of normal granulosa cells have been studied extensively, little is known about the molecular mechanism of GCT progression. Here, we characterise the unique behavioural properties of a granulosa tumour cell line, KGN cells, for the molecular analysis of GCT progression.
Population doubling was carried out to examine the proliferation capacity of KGN cells. Moreover, the invasive capacity of these cells was determined using the in vitro invasion assay. The expression level of tumour markers in KGN cells at different passages was then determined by Western blot analysis. Finally, the growth and metastasis of KGN cells injected subcutaneously (s.c.) into nude mice was observed 3 months after injection.
During in vitro culture, the advanced passage KGN cells grew 2-fold faster than the early passage cells, as determined by the population doubling assay. Moreover, we found that the advanced passage cells were 2-fold more invasive than the early passage cells. The expression pattern of tumour markers, such as p53, osteopontin, BAX and BAG-1, supported the notion that with passage, KGN cells became more aggressive. Strikingly, KGN cells at both early and advanced passages metastasized to the bowel when injected s.c. into nude mice. In addition, more tumour nodules were formed when the advanced passage cells were implanted.
KGN cells cultured in vitro acquire an aggressive phenotype, which was confirmed by the analysis of cellular activities and the expression of biomarkers. Interestingly, KGN cells injected s.c. are metastatic with nodule formation occurring mostly in the bowel. Thus, this cell line is a good model for analysing GCT progression and the mechanism of metastasis in vivo.
颗粒细胞瘤（GCTs）常见于绝经后女性，生长相对缓慢。尽管对正常颗粒细胞的生理特性已进行了广泛研究，但对GCT进展的分子机制了解甚少。在此，我们对一种颗粒肿瘤细胞系KGN细胞的独特行为特性进行表征，以用于GCT进展的分子分析。
进行群体倍增实验以检测KGN细胞的增殖能力。此外，使用体外侵袭实验测定这些细胞的侵袭能力。然后通过蛋白质免疫印迹分析确定不同传代的KGN细胞中肿瘤标志物的表达水平。最后，在注射3个月后观察皮下（s.c.）注射到裸鼠体内的KGN细胞的生长和转移情况。
在体外培养过程中，通过群体倍增实验确定，传代较后的KGN细胞生长速度比传代较早的细胞快2倍。此外，我们发现传代较后的细胞侵袭性比传代较早的细胞高2倍。肿瘤标志物如p53、骨桥蛋白、BAX和BAG-1的表达模式支持随着传代KGN细胞变得更具侵袭性这一观点。令人惊讶的是，传代早和传代后的KGN细胞皮下注射到裸鼠体内后均转移至肠道。此外，植入传代较后的细胞时形成的肿瘤结节更多。
体外培养的KGN细胞获得了侵袭性表型，这通过细胞活性分析和生物标志物表达得以证实。有趣的是，皮下注射的KGN细胞具有转移性，结节形成主要发生在肠道。因此，该细胞系是分析GCT进展及体内转移机制的良好模型。
