利用斑馬魚胚胎模式探討抗癌藥物imatinib的毒性

Abstract

Imatinib是一種被廣泛運用於治療慢性顆粒性白血病的標靶藥物，其作用機轉是透過抑制白血病病人體內突變的BCR-ABL基因產生的酪氨酸激酶，進而抑制不正常白血球的增生，以達到治療白血病的用途。由於imatinib被大量使用，已經環境中被檢測出，加上imatinib結構非常穩定不易分解，對水生生物是潛在的危害風險。Imatinib在臨床上的副作用有皮膚毒性與眼毒性，但對於水生生物是否會產生類似毒性仍未被研究。本研究以斑馬魚胚胎為模式，探討imatinib對胚胎所產生的致死與亞致死毒性。胚胎以0、50、100、200、300、400、500 μM imatinib進行96小時暴露，發現濃度高於400 μM imatinib會大量死亡，並且觀察到胚胎皮膚角質細胞受損剝落，推測是主要致死原因。雖然在低於死亡濃度並未發現胚胎在形態上出現異常，但imatinib濃度高於200 μM會導致側線毛細胞數量減少。利用RNA定序技術發現，300 μM的imatinib處理後會導致胚胎許多視覺相關基因表現下降，並使胚胎視覺運動反應異常。此外，研究發現水中鈣離子濃度會影響胚胎表皮細胞對imatinib的耐受性，高鈣環境可以降低imatinib所造成的角質細胞與毛細胞損傷，而低鈣環境則會增加imatinib造成的損傷。本研究發現高濃度的imatinib可能會對魚類造成潛在危害，以及水中鈣離子濃度對魚類皮膚細胞的重要性。此外，imatinib對斑馬魚的毒性發現或許可以應用在降低臨床上的副作用。

Imatinib is a targeted drug that is widely used in the treatment of chronic granular leukemia. The mechanism is to inhibit the proliferation of abnormal white blood cells by inhibiting the tyrosine kinase produced by the mutated BCR-ABL gene in leukemia patients. Since imatinib is widely used and has been detected in the environment, and the structure of imatinib isvery stable and difficult to decompose, it is a potential hazard to aquatic organisms. The clinical side effects of imatinib include skin toxicity and ocular toxicity, but whether similar toxicity to aquatic organisms organisms has not been studied. In this study, zebrafish embryos were used as a model to investigate the lethal and sublethal toxicity of imatinib to embryos. Embryos were exposed to 0, 50, 100, 200, 300, 400, and 500 μM imatinib for 96 hours. It was found that the concentration of imatinib higher than 400 μM would cause a large number of deaths, and the damage of embryo keratinocytes which was presumed to be the leading caus e of death. No morphological abnormalities were found in embryos below lethal concentrations, while the concentration of imatinib higher than 200 μM reduced lateral line hair cell numbers. Using RNA-sequencing technology, it was found that treatment with 300 μM imatinib reduced the expression of many vision-related genes in embryos and caused abnormal optomotor responses in embryos. In addition, the study found that Ca2+ concentration affects the tolerance of embryonic epidermal cells to imatinib. A high Ca2+ environment can reduce the damage to keratinocytes and hair cells caused by imatinib, while a low Ca2+ environment can increase the damage caused by imatinib. This study found the potential hazard of high concentrations of imatinib to fish and the importance of Ca2+ concentration for fish skin cells. In addition, the toxicity findings of imatinib in zebrafish may be applied to reduce side effects in the clinic.