長期葉酸消耗對人類肝癌細胞株HepG2之細胞生長繁殖及形態變化的影響

Prolonged Folate Depletion Affects Cellular Proliferation and Morphological Alteration of Human HepG2 Cell Line

許瑞芬(Rwei-Fen S. Huang) ； 何雲秀(Yun-Hsiu Ho) ； 林慧麗(Huei-Li Lin)

《中華民國營養學會雜誌》 23卷3期 (1998/08) Pp. 297-308

https://doi.org/10.6691/JCNS.199808_23(3).0007

摘要

爲了模擬人類葉酸攝取不足，導致體內組織器官細胞的葉酸消耗至邊緣性缺乏之營養狀況，本研究乃培養人類肝癌HepG2細胞於減除外源性葉酸之培養基中，探討在長期消耗細胞內葉酸，對肝癌細胞之生長繁殖（倍增時間，相對生長率及死亡率）與形態變化之影響。葉酸消耗四週的細胞相對生長速率降低至36%，細胞繁殖倍增時間延長爲75小時。長期葉酸消耗七週可使人類肝癌細胞生長延遲至完全停滯。葉酸消耗細胞雖然生長延遲停頓，細胞卻只有輕微之死亡狀況。根據trypan blue染色評估之結果，四週葉酸消耗細胞死亡率僅爲15%。長期葉酸消耗七週之細胞，細胞死亡率也僅昇高爲26%。然而，存活細胞則有巨觀形態的變化。以倒立式顯微鏡觀察並拍照，發現葉酸消耗四週至六週的細胞脹大變形，細胞內充滿大空泡。再利用流式細胞儀(Flow Cytometer)分析葉酸消耗細胞之體積和顆粒密集度，結果顯示葉酸消耗四週的細胞，細胞體積變大而且細胞顆粒密度也變高。更有一群疑似進行程式凋亡的細胞體(apoptotic bodies)出現。長期葉酸消耗是否也會引發細胞程式凋亡，則須進一步的研究來確認。

關鍵字

葉酸消耗 ； 肝癌細胞株HepG2 ； 相對生長速率 ； 程式凋亡細胞體

並列摘要

Insufficiency of dietary folate intake leads to deplete intracellular folate levels and results in marginal or severe folate deficiency. To simulate human folate-deficient situation and to investigate the cellular consequence of such folate depletion, human HepG2 cells were cultured under the condition of prolonged folate depletion and effects of folate depletion on cellular growth rates, death rates as well as morphology were evaluated. The relative growth rates of HepG2 cells cultured in folate-depleted media for 4 weeks decreased to 36%. The cellular doubling time also increased to 75 hours. HepG2 cells exhibited complete growth arrest under prolonged folate depletion of 7 weeks. Although cells under prolonged folate depletion have growth retardation or growth arrest, most of them would still alive. By trypan blue exclusion test, the cell death rates of 4 week folate-depleted HepG2 were only 15%, wherein death rates of 7 week folate deplete cells slightly increased to 26%. However, those alive folatedepleted cells exhibited megaloblastic abnormality, which was photograghed under inverted microscopy. Using flow cytometer to analyze cellular size and cellular granularity of density, we found all cellular volume, size and granularity of density in week 4 folate-depleted HepG2 cells were increased. In addition, another subpopulation with decreased cell size and density was detectable among the prolonged folate deplete cells, which were speculated as apoptotic bodies. Further studies are needed to investigate the apoptotic induction of HepG2 cells under this prolonged folate-depleted condition.

並列關鍵字

folate depletion ； HepG2 cells ； relative growth rates ； apoptotic bodies