發(fā)布時(shí)間：2018-09-04 07:44

【摘要】：基于ROS治療腫瘤是抗癌的一種新思路,目前被認(rèn)為有可能成為腫瘤治療的一種基本手段。與正常細(xì)胞相比,腫瘤細(xì)胞處于相對(duì)較高的氧化還原態(tài),因此通過(guò)升高細(xì)胞ROS水平(促進(jìn)ROS生成或/和抑制ROS清除)可使腫瘤細(xì)胞先于正常細(xì)胞達(dá)到ROS死亡閾值,進(jìn)而死亡。在基于ROS的治療假說(shuō)中,ROS被認(rèn)為是一種選擇性殺傷腫瘤細(xì)胞的有效手段。劑量-效應(yīng)關(guān)系是藥物治療學(xué)中最基本的治療原則,而ROS劑量與細(xì)胞毒性之間是否存在劑量-效應(yīng)關(guān)系,目前尚無(wú)報(bào)道。因此,我們開展該項(xiàng)研究進(jìn)行ROS與其劑量效應(yīng)關(guān)系的探討。 在本研究中,我們隨機(jī)選擇了4種腫瘤細(xì)胞系(4T1、Bcap37、Hela、HepG2)和4例原代結(jié)直腸腫瘤細(xì)胞,利用不同氧化還原劑改變腫瘤細(xì)胞ROS水平,研究ROS改變對(duì)腫瘤細(xì)胞生長(zhǎng)增殖的影響,進(jìn)而分析ROS水平與其細(xì)胞毒性之間的相關(guān)性。結(jié)果發(fā)現(xiàn),異硫氰酸苯乙酯(PEITC)和蓽茇酰胺(PL)在升高腫瘤細(xì)胞ROS水平的同時(shí)導(dǎo)致細(xì)胞死亡；而與PEITC和PL相比,乳酸(LA)引起更高的ROS水平卻不殺傷細(xì)胞；L-丁硫氨酸-亞砜亞胺(L-BSO)比PEITC、PL能更有效地降低細(xì)胞內(nèi)GSH含量、更顯著地升高ROS水平,卻允許細(xì)胞進(jìn)行性增殖。這些結(jié)果提示腫瘤細(xì)胞增殖或死亡與ROS水平高低或GSH含量多少之間無(wú)明顯相關(guān)性。為進(jìn)一步驗(yàn)證細(xì)胞死亡與ROS是否相關(guān),我們通過(guò)還原劑氮乙酰半胱氨酸(NAC)和SOD-CAT類似物(EUK8、EUK134)降低PEITC、PL等藥物升高的ROS后,觀察細(xì)胞增殖或死亡情況。實(shí)驗(yàn)結(jié)果表明NAC (4mM)可逆轉(zhuǎn)PEITC、多柔比星(Dox)或三氧化二砷(ATO)升高的ROS,但不能阻斷它們導(dǎo)致的細(xì)胞死亡；而相反,NAC (4mM)不能逆轉(zhuǎn)PL升高的ROS,卻可完全阻斷其導(dǎo)致的細(xì)胞死亡；EUK8、EUK134均可逆轉(zhuǎn)上述藥物升高的ROS,但均不能阻斷藥物導(dǎo)致的細(xì)胞死亡。這說(shuō)明細(xì)胞死亡與否與ROS高低之間不存在相關(guān)性。最后,我們?cè)谠Y(jié)直腸腫瘤細(xì)胞中發(fā)現(xiàn),LA在顯著升高腫瘤細(xì)胞ROS水平的同時(shí)并不殺傷腫瘤細(xì)胞；而與LA相比,PEITC、PL或ATO升高的ROS水平相對(duì)較低,但均導(dǎo)致細(xì)胞死亡。 綜上所述,本研究發(fā)現(xiàn)ROS水平與其細(xì)胞毒性之間無(wú)明顯的劑量-效應(yīng)關(guān)系,如果ROS是導(dǎo)致細(xì)胞死亡的直接原因,它就應(yīng)該符合藥物治療中最基本的劑量-效應(yīng)關(guān)系原則。這是基于ROS治療腫瘤中亟待解決的關(guān)鍵問(wèn)題。
[Abstract]:Tumor therapy based on ROS is a new way of anticancer, and it is considered to be a basic method of tumor therapy. Compared with normal cells, tumor cells are in a relatively high redox state. Therefore, by increasing the level of ROS (promoting ROS production or / and inhibiting ROS clearance), tumor cells can reach ROS death threshold before normal cells and then die. Ros is considered to be an effective method to selectively kill tumor cells in the treatment hypothesis based on ROS. The dose-effect relationship is the most basic therapeutic principle in drug therapeutics, but whether there is a dose-effect relationship between the dose of ROS and cytotoxicity has not been reported. Therefore, we carried out this study to investigate the relationship between ROS and its dose effect. In this study, we randomly selected four tumor cell lines (4T1 Bcap37 Hela HepG2) and four primary colorectal cancer cells to change the ROS level of tumor cells with different oxidizing reductants, and to study the effect of ROS changes on the growth and proliferation of tumor cells. The correlation between ROS level and cytotoxicity was analyzed. The results showed that ethyl isothiocyanate (PEITC) and Piper longum (PL) increased the ROS level of tumor cells and resulted in cell death, but lactic (LA) induced higher ROS level than PEITC and PL, but did not kill the cells. Compared with PEITC,PL, L-butylthiaminine-sulfoxide (L-BSO) can decrease the GSH content more effectively and increase the ROS level more significantly, but it allows the cells to proliferate progressively. These results suggest that there is no significant correlation between proliferation or death of tumor cells and the level of ROS or the content of GSH. To further verify the correlation between cell death and ROS, we observed cell proliferation or cell death after reducing the ROS of PEITC,PL by reducing PEITC,PL (NAC) and SOD-CAT analogue (EUK8,EUK134). The results showed that NAC (4mM) could reverse the cell death induced by PEITC, doxorubicin (Dox) or arsenic trioxide (ATO), but could not block the cell death caused by (ATO), whereas 4mM (4mM) could not reverse the PL elevation of ROS, but could completely block the cell death. EUK8,EUK134 could reverse the increase of ROS, but could not block the cell death caused by the drug. This suggests that there is no correlation between cell death and ROS. Finally, we found that the ROS level of primary colorectal tumor cells was significantly increased by LLA, while the level of ROS was lower than that of LA, but both of them resulted in cell death. In conclusion, there is no significant dose-effect relationship between ROS level and cytotoxicity. If ROS is the direct cause of cell death, it should conform to the most basic dose-effect relationship principle in drug therapy. This is a key problem to be solved in the treatment of tumor based on ROS.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：R73-36

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相關(guān)期刊論文 前2條

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本文編號(hào)：2221438