具潛力之第一型葡萄糖轉運蛋白抑制劑與順鉑合併使用於乳癌細胞協同機轉之研究

乳癌在全世界無論是癌症發生率或致死率都居高不下。順鉑為乳癌化療之常見用藥。然而，因順鉑產生之眾多嚴重副作用，併用療法可能為可同時減少副作用並增強抗癌活性之策略。日前研究中發現由於 Warburg effect ，第一型葡萄糖轉運蛋白可能為癌症治療之新標靶。此研究目的為探討順鉑與由高通量篩選出具潛力之葡萄糖轉運蛋白抑制劑， #43合併使用於 MCF-7 乳癌細胞株之協同作用及其機轉。研究過程中發現順鉑與 #43併用會藉由細胞凋亡路徑增加細胞毒性，且順鉑與 #43 會分別造成細胞週期停滯於 S 、 G2/M 及 G0/G1。此外，藥物合併使用也觀察到細胞中活性含氧物之提升及粒線體膜電位之損失。因順鉑對於 DNA 的破壞性，實驗結果顯示合併處理藥物使 Chk1、Chk2 磷酸化及 -H2AX 上升且增加 p53 表現及活化，顯示出 #43 可增強順鉑之 DNA 破壞性。MAPK 訊息傳導調控細胞增殖、細胞分化及細胞凋亡。特別的是 #43 單獨使用使促進對於細胞存活重要之 MEK1/2 及 ERK1/2 磷酸化上升。但當與順鉑合併使用時此效果會被消去且磷酸化之 MEK1/2 及 ERK1/2 甚至與控制組相比更加減少。另一方面，p38 磷酸化於順鉑及 #43 合併使用時增加。Akt/mTOR 訊息傳遞路徑與細胞生長、細胞增殖及細胞代謝皆有相關性。此路徑之下游蛋白 p70S6K 及 4EBP1 之磷酸化於合併使用順鉑與 #43 之情形下被抑制，顯示其細胞生長抑制作用之效果。總結來說， MAPK 訊息傳遞路徑、Akt/mTOR 訊息傳遞路徑、氧化壓力及細胞凋亡皆可能於順鉑及 #43 在 MCF-7 細胞株之協同作用扮演重要的角色。

關鍵字

順鉑；第一型葡萄糖轉運蛋白抑制劑；乳癌； MAPK 訊息傳遞路徑； PI3K/Akt/mTOR 訊息傳遞路徑； DNA 損傷；氧化壓力

並列摘要

Breast cancer remains within the top position when it comes to the cancer incidence and mortality rate worldwide. Cisplatin is a commonly used chemotherapeutic drug for breast cancer. However, owing to the serious side effects of cisplatin, drug combination may be an effective strategy to reduce side effects and increase the anticancer activities simultaneously. In recent studies, it was found that GLUT1 may be a target for cancer treatment because of the Warburg effect. The purpose of this study was to determine whether the combination of a potential GLUT1 inhibitor #43 (obtained from a high throughput screening) and cisplatin exerted a synergistic anticancer effect in MCF 7 breast cancer cells and to investigate the underlying mechanisms. In the present study, we found that #43 could enhance the cytotoxicity of cisplatin via induction of apoptosis, and that cisplatin and #43 cause S, G2/M and G0/G1 arrest, respectively. Moreover, an increase in intracellular ROS and the loss of mitochondrial membrane potential were also observed. Cisplatin is a DNA damaging agent. We found that phosphorylation of DNA damage checkpoint kinases Chk1 and Chk2, and DNA damage marker, -H2AX were increased and p53 was also induced and activated by the combination treatment, suggesting that #43 may enhance the DNA damaging effect of cisplatin. The MAPK pathway regulates cell proliferation, differentiation and apoptosis. Interestingly, #43 alone induced phosphorylation of MEK1/2 and ERK1/2, which may be involved in cell survival. When combined with cisplatin, the effects were reversed and both p-MEK1/2 and p-ERK1/2 were even downregulated compared to the untreated controls. On the other hand, p38 phosphorylation was increased by the combination of cisplatin and #43. The Akt/mTOR signaling pathway is involved in cell growth, proliferation and metabolism. Phosphorylation of p70S6K and 4EBP1, downstream effectors of this pathway, was inhibited by the combination treatment, indicating a growth inhibitory effect. In conclusion, our data indicate that the MAPK pathway, Akt/mTOR pathway, oxidative stress and apoptosis may be involved in the synergism of cisplatin and #43 in MCF-7 breast cancer cells.

並列關鍵字

Cisplatin ； GLUT1 inhibitor ； breast cancer ； MAPK pathway ； PI3K/Akt/mTOR pathway ； DNA damage ； oxidative stress

參考文獻

1. Bray, F., Ferlay, J., Soerjomataram, I., Siegel, R. L., Torre, L. A. and Jemal, A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2018, 68, 394-424.