干擾素α2b為近年來重要的抗病毒與抗癌用藥，然而，利用中國倉鼠卵巢細胞表現人類干擾素α2b，卻產生表現量低的問題。以產量1毫克來說，就需要用到1.1 x 1011 個細胞生產，規模相當於367個T75培養瓶所培養的細胞數目。對於干擾素α2b處理中國倉鼠卵巢細胞，進而探討干擾素所引起的細胞毒性，我們發現無明顯的生長抑制現象產生。因此，我們推測干擾素α2b在中國倉鼠卵巢細胞表現量低的原因，可能導因於轉錄效率或轉譯效率的不良。為了深入了解人類干擾素α2b表現量低是否由低轉錄效率所導致，本文首先以人類干擾素α2b與綠螢光蛋白進行轉錄效率比較分析。結果顯示，在細胞整體與細胞核的RNA總數上，人類干擾素α2b高於綠螢光蛋白4倍；其次，在細胞質及細胞核mRNA的數量上，人類干擾素α2b與綠螢光蛋白並無明顯差異；最後，在蛋白質表現量方面，人類干擾素α2b遠比綠螢光蛋白低。另外，在過去文獻上曾提及RNA splicing能有效提高蛋白質產量，當我們利用RNA splicing改善人類干擾素α2b表現時，也發現到mRNA的增加無法明顯增加蛋白質的表現量。所以，人類干擾素α2b在中國倉鼠卵巢細胞表現量低的原因可能不在於轉錄效率，而是mRNA的轉譯起始效率或轉譯的中間過程。未來，深入的研究與探討可朝蛋白質轉譯起始效率與合成速度方面進行，並搭配動力學分析人類干擾素α2b在中國倉鼠卵巢細胞表現的反應瓶頸，進而解決表現效率不佳的問題。

Most recently, IFN-α2b has become an important anti-virus and anti-cancer drug. However, expressed human IFN-α2b (HuIFN-α2b) at low levels in Chinese hamster ovary (CHO) cells were observed. 1 mg of IFN-α2b production will require 1.1 x 1011 cells which are equivalent to cultured cells in 367 of T75 flasks. For the cytotoxicity of CHO cells induced by HuIFN-α2b, the growth inhibition still has not been observed notably after HuIFN-α2b treatment. Hence, the problem that expressed HuIFN-α2b at very low levels in CHO cells results from inefficient transcription or translation is considered. In results, firstly, copies of HuIFN-α2b is 4- fold higher than that of EGFP reporter in comparison of the cell total and nuclear RNA. Secondly, the copy number difference between HuIFN-α2b and enhanced green fluorescence protein (EGFP) was not distinguished markedly in comparison of cytoplasmic mRNA and nuclear mRNA. Finally, the amount of expressed HuIFN-α2b was significantly lower than that of EGFP in CHO cells. On the other hand, effects of splicing on enhancing protein expression have been demonstrated in the published paper. In spite of the increase in the amount of mRNA levels, HuIFN-α2b expression could not be raised markedly as splicing was employed. Therefore, the reason expressed HuIFN-α2b at low levels in CHO cells might be mRNA inefficient translational initiation or the middle process of translation rather than the transcriptional efficiency. In the future, the translational initiation efficiency and the synthesis rate of HuIFN-α2b in CHO cells will be further studied. The bottleneck in this overall HuIFN-α2b expression process in CHO cells will also be analyzed by kinetics to optimize the expression efficiency.

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