評估併用Meloxicam和Doxorubicin於體外培養犬乳腺瘤細胞株(CMT-1)的效果

Abstract

化學治療應用於治療已轉移之犬乳腺腫瘤的療效仍未完全確定。然而，近期有許多研究指出應用COX-2拮抗劑於犬乳腺腫瘤細胞時具有抗腫瘤的效果。本研究的目的在於體外培養的犬乳腺腫瘤細胞環境中，評估合併使用COX-2拮抗劑和Doxorubicin的藥理作用及抗腫瘤效果。將Meloxicam的濃度分別調配為1、2、4、10、50、100和200 μM，Doxorubicin的濃度分別調配為62.5、125、250、500、1000和2000 nM，添加兩種不同濃度藥物至已貼附犬乳腺瘤細胞的96孔盤內繼續培養72小時後，研究各個不同濃度的藥物下對犬乳腺腫瘤細胞抑制生長的效果。將各個不同濃度的Meloxicam及Doxorubicin交互混合成42種不同濃度的組合，同樣的也培養72小時後評估對犬乳腺腫瘤細胞的抑制效果。細胞存活分析是透過MTT來做檢測。Meloxicam及Doxorubicin組別的IC50 分別為93.57 μM及343.94 nM。然而，發現Meloxicam及Doxorubicin的IC50濃度之間的藥理相互作用為相加的藥理作用。低劑量的Meloxicam不僅單獨使用時沒有抑制乳腺腫瘤細胞生長的效果，而在比較併用低劑量的Meloxicam和各個Doxorubicin濃度與單用Doxorubicin的效果時，發現並沒有顯著差異的作用。只有高劑量的Meloxicam濃度單獨使用下有抑制乳腺腫瘤細胞生長的效果，而高劑量的Meloxicam濃度併用各個Doxorubicin濃度下皆有具有顯著差異的相加效果。

Efficacy of chemotherapy in treatment of canine metastatic mammary gland tumor (MGT) has not been well established yet. However, many studies had documented COX-2 inhibitor used alone has shown antitumor activity in canine MGT recently. The purpose of present report is to evaluate the pharmacological and tumoricidal effect of the combination of COX-2 inhibitor with doxorubicin on established canine MGT cell lines and hypothesize the combination would have synergistic effect. To study the effect of different concentration of meloxicam (1, 2, 4, 10, 50, 100 and 200 μM), and doxorubicin (62.5, 125, 250, 500, 1000 and 2000 nM) on the proliferation of MGT cells, both groups are cultured for 72 hours. All concentrations of meloxicam and doxorubicin are combined to result in 42 different concentration combinations and incubated for 72 hours. Cell proliferation is assessed using a standard MTT assay. The IC50 of meloxicam and doxorubicin is 93.57μM and 343.94 nM, respectively. Exposure of tumor cells to IC50 combinations of meloxicam and doxorubicin reveal only sub-additive effect. The result of cell proliferation in the lower concentration of meloxicam group does not show inhibitive effect in CMT-1 cell line. The combination effect of lower concentration of meloxicam and any concentration of doxorubicin compared with the doxorubicin group do not reveal statistically significant effect in CMT-1 cell line. However, the result of cell proliferation in the higher concentration of meloxicam group shows statistically significant inhibitive effect in CMT-1 cell line, and the combination effect of higher concentration of meloxicam and any concentration of doxorubicin revealed statistically significant sub-additive effect with using doxorubicin alone.