藉由魚油恢復微型核糖核酸-378以誘導抗表皮生長因子受體抗體對KRAS基因突變癌症細胞的敏感性

Induce of anti-EGFR antibody sensitivity in KRAS mutated cancer cells by restoration of miR-378 with EPAee

郭力瑋(Li-Wei Kuo)

指導教授 ： 翁文慧

國立臺北科技大學/工程學院/生物科技研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00149

摘要

KRAS或BRAF基因突變在表皮生長因子受體路徑是一個重要的角色。依循先前研究發現，當在KRAS或BRAF基因突變的大腸直腸癌細胞經月桂酸(飽和脂肪酸)培養後會使微型核糖核酸-378高表現進而增加抗表皮生長因子受體抗體對細胞的敏感性。據此，本實驗使用FDA建議可食用的魚油 (EPAee，不飽和脂肪酸)置換月桂酸並使用大腸直腸癌細胞為研究模型做為研究方向。結果發現施予40 μM魚油作用後，可使KRAS突變型大腸直腸癌細胞的微型核糖核酸-378表現量上升；此外，KRAS突變型大腸直腸癌細胞與野生型大腸直腸癌細胞的ERK1/2總表現量下降(p= 0.022~0.035)，但卻使其磷酸化上升(p= 0.006~0.047)，但在BRAF突變型大腸直腸癌細胞卻是相反結果。有趣的是，細胞先施予40 μM魚油24小時後再以0.2 μM抗表皮生長因子受體抗體作用48小時可使KRAS突變型與野生型大腸直腸癌細胞的細胞存活性下降(p= 0.006-0.013)，但BRAF突變型大腸直腸癌細胞卻無改善對抗表皮生長因子受體抗體的敏感性。實際上，利用魚油誘導微型核糖核酸-378的高表現可能使KRAS基因突變的細胞恢復對抗表皮生長因子受體抗體的敏感性。雖然魚油對大腸直腸癌細胞的分子機制影響目前仍不太明確。本篇研究結果提供未來臨床KRAS突變型患者一個具潛力性的治療與解決方案。

關鍵字

大腸直腸癌 ； 微型核糖核酸-378 ； 魚油 ； 抗表皮生長因子受體抗體

並列摘要

KRAS or BRAF mutation has an important role in the epidermal growth factor receptor pathway (EGFR pathway). According to our pervious findings, up-regulation of the expression of miR-378 by lauric acid in KRAS or BRAF mutant CRC (Colorectal cancaer) cells will further trigger the cell’s sensitivity of anti-EGFR antibody. Herein, we replaced the lauric acid (saturated fatty acid) by EPAee (unsaturated fatty acid), an FDA-approved compound, and used CRC cells as a model for this study. Our studies showed that higher expression of miR-378 could be observed in KRAS mutant CRC cells treated with 40 μM EPAee; besides, the total ERK1/2 protein levels of KRAS mutant CRC cells and wild type CRC cell were shown lower expression level (p=0.022~0.035) after treating cells with 40 μM EPAee for 24 hours, while the higher phosphorylated proteins level of ERK1/2 could be noted (p=0.006~0.047); but opposite result was shown in BRAF mutant cell. Interestingly, cells treat with 40μM EPAee fed for 24 houes and then anti-EGFR antibody for 48 hours, showed the lower cell viability in the KRAS mutant and control wild type cells (p= 0.006~0.013); but cannot improve the sensitivity of anti-EGFR antibody in EPAee-fed BRAF mutant cell. Indeed, using EPAee induce the over expression of miR-378 could further restore the sensitivity of anti-EGFR antibody in KRAS mutant cells. Although the molecular mechanism of the effect of EPAee in CRC cells is still not clear. Our findings have offered a great potential for developing a new treatment method for KRAS mutant CRC patients.

並列關鍵字

Colorectal cacner ； miR-378 ； EPAee ； anti-EGFR antibody

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