FAM60A在生殖細胞癌的分化以及生長中所扮演的角色

Abstract

生殖細胞腫瘤（GCT）是由生殖細胞產生的腫瘤。生殖細胞腫瘤可以是良性或惡性的，通常發生在性腺 (卵巢和睾丸)內，性腺外的生殖細胞腫瘤常是胚胎的發育過程中，錯誤細胞遷移過程所產生的結果。 高達80％的惡性生殖細胞腫瘤具有12p 的iso-chromosome，它是生殖細胞腫瘤的特定遺傳標記。我們搜索了the Human Protein Altas，以尋找在染色體12p 可能的oncogene。我們發現FAM60A位於12p11.21，並且只表現在睾丸生殖細胞。在此研究中，我們探討FAM60A在生殖細胞癌的生長以及分化中扮演的角色。我們的研究發現，在生殖細胞腫瘤細胞株Ntera2 D1使用核糖核酸干擾（RNA interference）抑制FAM60A的表現量會抑制細胞增生、聚球（sphere formation）能力和移動的能力。此外，也會造成細胞周期停滯和細胞淍亡增加。另外，我們在Ntera2 D1細胞株穩定表現FAM60A會增加細胞移動以及聚球（sphere formation）能力。FAM60A的表現不影響Ntera2 D1的神經分化。以螢光素酶報告基因檢測系統分析，我們證實FAM60A是轉錄抑制子。透過微陣列基因表現分析結果，我們發現Nodal可能是受FAM60A調控的基因。此外，我們發現GCT比其他癌症細胞株更適用HDAC抑制劑panobinostat和belinostat 治療。

Germ cell tumors (GCTs) are a neoplasm derived from germ cells. Germ cell tumors can be benign or malignant. They usually occur in the gonads (ovary and testis). Germ cell tumors that originate outside the gonads are due to faulty cell migration during development of the embryo. Up to 80% of malignant GCTs have isochromosome 12p. Iso-chromosome 12p is a specific genetic marker of GCTs. Because the high frequency of gain of genetic material of 12p in testicular GCTs, we searched the Human Protein Atlas for the identification of the candidate oncogene in chromosome 12p. We identified a gene Family with Sequence Similarity 60 Member A (FAM60A) is a testicular germ cell-specific gene located at 12p11.21. In this study, we examined the roles of FAM60A in GCT growth and differentiation. We found that knockdown of FAM60A in GCT cell line Ntera2 D1 by shRNA suppressed cell proliferation, cell migration and sphere formation in vitro. Besides, it also caused cell cycle arrest and apoptosis. Ntera2 D1 cells stably transfected with FAM60A-expressing plasmid (Ntera2 D1-FAM60A) had enhanced cell migration and sphere formation ability as compared to vector control. The expression of FAM60A did not affect ability of neuronal differentiation in Ntera2 D1 cells. By using a luciferase reporter system, we found that FAM60A is a transcription repressor. Through microarray analysis, we identified that Nodal is a candidate gene regulated by FAM60A. We also found that GCTs are more susceptible to histone deacetylase (HDAC) inhibitors panobinostat and belinostat.