楊 翠 徐 瑜 胡義德
二甲雙胍對肺腺癌耐厄洛替尼細(xì)胞株A549ER的耐藥逆轉(zhuǎn)作用
楊 翠1徐 瑜2胡義德1
目的探討二甲雙胍對人肺腺癌耐厄洛替尼細(xì)胞株A549ER的耐藥逆轉(zhuǎn)作用。方法將人肺腺癌細(xì)胞株A549細(xì)胞設(shè)為親本組;將耐厄洛替尼細(xì)胞株A549ER細(xì)胞分為空白對照組、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組(厄洛替尼+二甲雙胍組),采用CCK8法檢測不同濃度藥物作用下各組細(xì)胞的50%抑制濃度(IC50),計算耐藥倍數(shù)和逆轉(zhuǎn)倍數(shù)。采用流式細(xì)胞術(shù)檢測各組A549ER細(xì)胞的凋亡率和細(xì)胞周期,計算增殖指數(shù)。結(jié)果在0~20 mmol/L濃度范圍內(nèi),二甲雙胍對A549細(xì)胞及A549ER細(xì)胞均有生長抑制作用,抑制率隨二甲雙胍濃度升高而增加。厄洛替尼對A549細(xì)胞和A549ER的IC50分別為15.15 μmol/L和118.8 μmol/L,A549ER的耐藥倍數(shù)為7.84。聯(lián)合用藥組A549ER細(xì)胞IC50為73.55 μmol/L,耐藥倍數(shù)為4.85。二甲雙胍對A549ER厄洛替尼耐藥性的逆轉(zhuǎn)倍數(shù)為1.62??瞻讓φ战M、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組的凋亡率分別為(5.53±3.00)%、(7.51±3.73)%、(10.25±4.23)%和(16.92±1.20)%。根據(jù)細(xì)胞周期結(jié)果計算空白對照組、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組的增殖指數(shù)分別為0.84±0.15、0.78±0.10、0.73±0.08和0.60±0.09。結(jié)論A549ER細(xì)胞較A549細(xì)胞對厄洛替尼有明顯的耐藥性;二甲雙胍對A549ER細(xì)胞厄洛替尼的耐藥性具有逆轉(zhuǎn)作用;二甲雙胍通過抑制細(xì)胞生長、促進(jìn)細(xì)胞凋亡、減緩細(xì)胞周期進(jìn)程等途徑逆轉(zhuǎn)A549ER細(xì)胞耐藥。
腺癌,肺; 二甲雙胍; 厄洛替尼; 耐藥; 逆轉(zhuǎn)
肺癌是最常見的惡性腫瘤之一,也是目前癌癥相關(guān)死亡的主要原因之一[1-2]。近年來,靶向治療藥物如表皮生長因子受體酪氨酸激酶抑制劑(EGFR-TKI)厄洛替尼等在肺癌的治療中取得了良好的效果,甚至被推薦作為一線治療藥物使用[3-5]。然而,部分患者在治療過程中逐漸產(chǎn)生耐藥直接影響后期的治療效果[6]。二甲雙胍是一種胰島素增敏劑,被廣泛用于2型糖尿病的治療。但最近的研究表明,二甲雙胍能抑制腫瘤細(xì)胞的增殖,增強(qiáng)化療藥物的敏感性[7]。本研究擬探討聯(lián)合使用二甲雙胍是否能逆轉(zhuǎn)耐厄洛替尼肺癌細(xì)胞株對厄洛替尼的耐藥性。
一、實驗材料
1.細(xì)胞株:人肺腺癌 A549細(xì)胞株及耐厄洛替尼細(xì)胞株A549ER由第三軍醫(yī)大學(xué)新橋醫(yī)院全軍腫瘤研究所提供[8]。
2.藥品與試劑:厄洛替尼為南京安格醫(yī)藥化工有限公司產(chǎn)品;二甲雙胍為sigma公司產(chǎn)品;RPMI1640培養(yǎng)基和青霉素鏈霉素溶液-雙抗均為Hyclone公司產(chǎn)品;胎牛血清為Gibco公司產(chǎn)品;CCK-8為廣州奕源生物科技有限公司產(chǎn)品;細(xì)胞凋亡試劑盒和細(xì)胞周期試劑盒均為BD公司產(chǎn)品。
二、實驗方法
1.細(xì)胞培養(yǎng):A549細(xì)胞培養(yǎng)在含10%胎牛血清的RPMI1640培養(yǎng)基中。A549ER細(xì)胞培養(yǎng)在含10%胎牛血清、25 μmol/L厄洛替尼(維持濃度)的RPMI1640培養(yǎng)基中。細(xì)胞置于37 ℃、 5% CO2培養(yǎng)箱中培養(yǎng)。培養(yǎng)基變黃換液,細(xì)胞鋪滿培養(yǎng)瓶底90%以上時0.25%胰酶消化傳代。取對數(shù)生長期細(xì)胞為實驗對象。
2.細(xì)胞分組:將培養(yǎng)在普通血清培養(yǎng)基中的A549細(xì)胞設(shè)為親本組。將A549ER細(xì)胞分為空白對照組、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組,分別給予不含藥物的血清培養(yǎng)基、含25 μmol/L厄洛替尼的血清培養(yǎng)基、含5 mmol/L二甲雙胍的血清培養(yǎng)基、含25 μmol/L厄洛替尼和5 mmol/L二甲雙胍的血清培養(yǎng)基培養(yǎng)。
3. CCK-8法檢測二甲雙胍對A549和A549ER的生長抑制作用:0.25%胰酶消化、血清培養(yǎng)基重懸A549細(xì)胞及A549ER細(xì)胞并計數(shù),分別按5000個/孔接種于96孔板,置于37 ℃、 5% CO2培養(yǎng)箱中培養(yǎng)。12 h后細(xì)胞貼壁,吸除孔內(nèi)培養(yǎng)液,分別加入含不同濃度二甲雙胍 (1 mmol/L, 2.5 mmol/L, 5 mmol/L, 7.5 mmol/L, 10 mmol/L, 12.5 mmol/L, 15 mmol/L, 20 mmol/L) 的血清培養(yǎng)基,同時設(shè)置空白孔(僅有培養(yǎng)基,無細(xì)胞)和對照孔(僅有培養(yǎng)基和細(xì)胞,未加藥),每組設(shè)置4個復(fù)孔。置于37 ℃、 5% CO2培養(yǎng)箱中繼續(xù)培養(yǎng)48 h。48 h后吸除孔內(nèi)培養(yǎng)液,分別加入100 μl血清培養(yǎng)基和10 μl CCK8,置于37 ℃、 5% CO2培養(yǎng)箱中繼續(xù)培養(yǎng)3 h。酶標(biāo)儀測定450 nm處各孔吸光度。按公式計算抑制率。
抑制率=[1-(實驗組OD值-空白組OD值)/(對照組OD值-空白組OD值)]×100%
4. CCK-8法檢測厄洛替尼對親本組A549細(xì)胞、厄洛替尼組A549ER細(xì)胞及聯(lián)合用藥組A549ER細(xì)胞的IC50:消化、血清培養(yǎng)基重懸各組細(xì)胞并計數(shù),按5000個/孔接種于96孔板,培養(yǎng)箱中繼續(xù)培養(yǎng)。12 h后細(xì)胞貼壁,吸除孔內(nèi)培養(yǎng)液,分別加入含不同濃度厄洛替尼 (0.01 μmol/L, 0.1 μmol/L, 1 μmol/L, 10 μmol/L, 100 μmol/L) 的血清培養(yǎng)基,同時設(shè)置空白孔(有培養(yǎng)基,無細(xì)胞)和對照孔(僅有培養(yǎng)基和細(xì)胞,未加藥),每組設(shè)置5個復(fù)孔。置于37 ℃、 5% CO2培養(yǎng)箱中繼續(xù)培養(yǎng)48 h。48 h后吸除孔內(nèi)培養(yǎng)液,分別加入100 μl血清培養(yǎng)基和10 μl CCK8,置于37 ℃、5% CO2培養(yǎng)箱中繼續(xù)培養(yǎng)3 h。酶標(biāo)儀測定450 nm處各孔吸光度。根據(jù)公式計算相應(yīng)的細(xì)胞生長抑制率,計算出IC50、耐藥倍數(shù)和逆轉(zhuǎn)倍數(shù)。
耐藥倍數(shù)=耐藥細(xì)胞株IC50/親本細(xì)胞株IC50
逆轉(zhuǎn)倍數(shù)=使用逆轉(zhuǎn)劑前IC50/使用逆轉(zhuǎn)劑后IC50
5. 流式細(xì)胞術(shù)檢測各組A549ER細(xì)胞周期:消化收集各組細(xì)胞,PBS洗滌2次,加入預(yù)冷處理的70%乙醇溶液4 ℃固定過夜,PBS洗滌除去乙醇,加PI染液(終濃度為50 μg/ml,含50 μg/ml RNase)在室溫避光條件下孵育30 min。流式細(xì)胞儀檢測細(xì)胞周期。按公式計算細(xì)胞增殖指數(shù)。
增殖指數(shù)=(S期百分比+G2/M期百分比)/(G0/G1期百分比)
6. 流式細(xì)胞術(shù)檢測各組A549ER細(xì)胞凋亡率:消化收集各組細(xì)胞,預(yù)冷的PBS洗滌2次,PBS重懸并計數(shù)細(xì)胞,使100 μl懸液中含約5×105個細(xì)胞,離心棄上清,加入400μl 1×Annexin V Binding Buffer懸浮細(xì)胞,加入5 μl的Annexin V-FITC混勻后,避光室溫孵育10 min。加入5 μl Propidium Iodide染色,避光室溫孵育5 min。流式細(xì)胞儀檢測細(xì)胞凋亡率。
三、統(tǒng)計學(xué)方法
一、二甲雙胍對A549細(xì)胞和A549ER細(xì)胞的生長抑制作用
在0至20 mmol/L濃度范圍內(nèi),二甲雙胍對A549細(xì)胞及A549ER細(xì)胞均有生長抑制作用,抑制率隨二甲雙胍濃度升高而增加。當(dāng)濃度≤5 mmol/L時,二甲雙胍對A549細(xì)胞和A549ER細(xì)胞的抑制率無差異;當(dāng)濃度>5 mmol/L時,二甲雙胍對A549ER細(xì)胞的抑制率高于A549細(xì)胞(P<0.01),見表1,圖1。
圖1 二甲雙胍對A549細(xì)胞和A549ER細(xì)胞的抑制曲線
二、厄洛替尼對各組細(xì)胞的抑制作用
不同濃度厄洛替尼對親本組A549細(xì)胞、厄洛替尼組A549ER細(xì)胞及聯(lián)合用藥組A549ER細(xì)胞的抑制率見表2。根據(jù)GraphPad.Prism.v5.01軟件計算親本組A549細(xì)胞IC50為15.15 μmol/L,厄洛替尼組A549ER細(xì)胞IC50為118.8 μmol/L,聯(lián)合用藥組A549ER細(xì)胞IC50為73.55 μmol/L。根據(jù)公式計算厄洛替尼組A549ER細(xì)胞對厄洛替尼的耐藥倍數(shù)為7.84,聯(lián)合用藥組A549ER細(xì)胞對厄洛替尼的耐藥倍數(shù)為4.85。二甲雙胍對A549ER細(xì)胞對厄洛替尼耐藥性的逆轉(zhuǎn)倍數(shù)為1.62。
表1 二甲雙胍對A549細(xì)胞和A549ER細(xì)胞的抑制率
表2 CCK8法檢測不同濃度厄洛替尼對各組細(xì)胞的抑制率
三、各組A549ER細(xì)胞周期結(jié)果及增殖指數(shù)
流式細(xì)胞術(shù)檢測各組A549ER細(xì)胞周期結(jié)果如表3所示。根據(jù)細(xì)胞周期結(jié)果計算空白對照組、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組的增殖指數(shù)分別為0.84±0.15、0.78±0.10、0.73±0.08和0.60±0.09。聯(lián)合用藥組增殖指數(shù)較其他三組均降低,但僅與空白對照組的差異有統(tǒng)計學(xué)意義(P<0.05)。
表3 各組A549ER細(xì)胞周期結(jié)果及增殖指數(shù)
四、各組A549ER細(xì)胞凋亡率
流式細(xì)胞術(shù)檢測空白對照組、厄洛替尼組、二甲雙胍組和聯(lián)合用藥組的凋亡率分別為(5.53±3.00)%、(7.51±3.73)%、(10.25±4.23)%和(16.92±1.20)%。聯(lián)合用藥組凋亡率較其他三組均顯著升高(P<0.01、P<0.01、P<0.05),見圖2。
注:A:空白對照組;B:厄洛替尼組;C:二甲雙胍組;D:聯(lián)合用藥組
靶向治療為肺癌的治療提供了新的方法。厄洛替尼作為主要的靶向治療藥物之一,被越來越廣泛地應(yīng)用于肺癌的治療中并取得了良好的治療效果[9]。然而,耐藥的產(chǎn)生成為影響厄洛替尼治療效果的重要因素,對厄洛替尼耐藥機(jī)制的研究成為了新的熱點(diǎn)[6]。最新研究表明,在肺癌中特定miRNA能夠調(diào)節(jié)Axl介導(dǎo)的EGFR-TKI耐藥性[10]。另一項研究也表明,在非小細(xì)胞肺癌中改變miR-21/PTEN的表達(dá)能夠調(diào)節(jié)肺癌細(xì)胞對EGFR-TKI的耐藥性[11]。而在小細(xì)胞肺癌中,miR-200b能夠通過調(diào)節(jié)ZEB2來調(diào)整多藥耐藥性[12]。對于本研究所采用的A549肺腺癌細(xì)胞,研究顯示核糖體蛋白l39-L可能在細(xì)胞耐藥機(jī)制中發(fā)揮重要作用[13]。
近年來二甲雙胍被發(fā)現(xiàn)能抑制腫瘤細(xì)胞的增殖,增強(qiáng)化療藥物的敏感性,這提示二甲雙胍可能將在肺癌的預(yù)防、治療中發(fā)揮重要作用[7]。因此,研究二甲雙胍能否逆轉(zhuǎn)厄洛替尼耐藥性具有重要的臨床價值。
本實驗采用CCK8法檢測二甲雙胍對人肺腺癌細(xì)胞株A549及耐厄洛替尼細(xì)胞株A549ER的生長抑制作用。發(fā)現(xiàn)二甲雙胍對兩株細(xì)胞均有明顯的生長抑制作用,且當(dāng)二甲雙胍濃度不超過5 mmol/L時,二甲雙胍對兩株細(xì)胞的生長抑制率無顯著差異。結(jié)合之前的文獻(xiàn)報道,我們選擇5 mmol/L的二甲雙胍濃度進(jìn)行后續(xù)實驗[14]。
CCK8法測得A549與A549ER細(xì)胞對厄洛替尼的IC50分別為15.15 μmol/L和118.8 μmol/L,與之前的文獻(xiàn)報道基本一致[8]。我們先將A549ER細(xì)胞在含厄洛替尼和二甲雙胍的培養(yǎng)基中培養(yǎng),然后再采用CCK8法測定A549ER細(xì)胞對厄洛替尼的IC50,新的IC50為73.55 μmol/L,較前降低,利用公式計算得到的耐藥倍數(shù)也較使用二甲雙胍前明顯降低,A549ER細(xì)胞對厄洛替尼的耐藥性明顯逆轉(zhuǎn),逆轉(zhuǎn)倍數(shù)為1.62。在我們的實驗方案中,先將A549ER細(xì)胞在含二甲雙胍和厄洛替尼的培養(yǎng)基中培養(yǎng),再使用僅含有不同濃度厄洛替尼的培養(yǎng)基測定IC50。這樣新測得的IC50就排除了聯(lián)合二甲雙胍協(xié)同抑制作用的影響。得到的結(jié)果更加能說明二甲雙胍對厄洛替尼耐藥性的逆轉(zhuǎn)作用。
我們的實驗結(jié)果提示二甲雙胍聯(lián)合化療后能提高A549ER細(xì)胞G0/G1期比例,這與文獻(xiàn)報道相一致[15-16],見圖3。且依據(jù)細(xì)胞周期結(jié)果計算得到的增殖指數(shù)也明顯降低,提示二甲雙胍聯(lián)合化療能抑制細(xì)胞增殖生長,也與之前的幾項報道相一致[14-17]。采用流式細(xì)胞術(shù)測定細(xì)胞凋亡發(fā)現(xiàn)經(jīng)二甲雙胍聯(lián)合化療處理的A549ER細(xì)胞凋亡率明顯升高,這在之前的文獻(xiàn)中也見有報道[15-16]。有研究報道二甲雙胍可能是通過激活JNK/p38 MAPK通路和GADD153基因來誘導(dǎo)肺癌細(xì)胞凋亡的[18]。通過我們的研究證實二甲雙胍對肺腺癌耐厄洛替尼細(xì)胞株的耐藥性具有逆轉(zhuǎn)作用,可能正是通過抑制細(xì)胞生長、促進(jìn)細(xì)胞凋亡、減緩細(xì)胞周期進(jìn)程和抑制細(xì)胞增殖等途徑起到發(fā)揮逆轉(zhuǎn)耐藥性的作用。二甲雙胍聯(lián)合化療可能是延緩或逆轉(zhuǎn)腫瘤化療藥物耐藥性的有效手段。
注:A:空白對照組;B:厄洛替尼組;C:二甲雙胍組;D:聯(lián)合用藥組
1 李 羲, 錢桂生. 肺癌臨床的罕見表現(xiàn)[J/CD]. 中華肺部疾病雜志: 電子版, 2013, 6(1): 4-7.
2 Jemal A, Bray F, Center MM, et al. Global cancer statistics[J]. CA Cancer J Clin, 2011, 61(2): 69-90.
3 D′Arcangelo M, Cappuzzo F. Erlotinib in the first-line treatment of non-small-cell lung cancer[J]. Expert Rev Anticancer Ther, 2013, 13(5): 523-533.
4 Nguyen KS, Neal JW. First-line treatment of EGFR-mutant non-small- cell lung cancer: the role of erlotinib and other tyrosine kinase inhibitors[J]. Biologics, 2012, 6: 337-345.
5 Tan BX, Yao WX, Ge J, et al. Prognostic influence of metformin as first-line chemotherapy for advanced nonsmall cell lung cancer in patients with type 2 diabetes[J]. Cancer, 2011, 117(22): 5103-5111.
6 Jackman D, Pao W, Riely GJ, et al. Clinical definition of acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non-small-cell lung cancer[J]. J Clin Oncol, 2010, 28(2): 357-360.
7 Gallagher EJ, LeRoith D. Diabetes, cancer, and metformin: connections of metabolism and cell proliferation[J]. Ann N Y Acad Sci, 2011, 1243: 54-68.
8 徐 睿, 孫建國, 陳正堂. 自噬在A549肺腺癌細(xì)胞耐厄洛替尼中的作用研究[J]. 重慶醫(yī)學(xué), 2013, 42(12): 1324-1329.
9 Li W, Zhou F, Zhou C. Role of erlotinib in the targeted treatment of non-small-cell lung cancer in Chinese patients[J]. Onco Targets Ther, 2014, 7: 253-261.
10 Wang Y, Xia H, Zhuang Z, et al. Axl-altered microRNAs regulate tumorigenicity and gefitinib resistance in lung cancer[J]. Cell Death Dis, 2014, 5: e1227.
11 Shen H, Zhu F, Liu J, et al. Alteration in Mir-21/PTEN Expression Modulates Gefitinib Resistance in Non-Small Cell Lung Cancer[J]. PLoS One, 2014, 9(7): e103305.
12 Fang S, Zeng X, Zhu W, et al. Zinc finger E-box-binding homeobox 2 (ZEB2) regulated by miR-200b contributes to multi-drug resistance of small cell lung cancer[J]. Exp Mol Pathol, 2014, 96(3): 438-444.
13 Liu HS, Tan WB, Yang N, et al. Effects of ribosomal protein l39-L on the drug resistance mechanisms of lung cancer A549 cells[J]. Asian Pac J Cancer Prev, 2014, 15(7): 3093-3097.
14 Wang Y, Dai W, Chu X, et al. Metformin inhibits lung cancer cells proliferation through repressing microRNA-222[J]. Biotechnol Lett, 2013, 35(12): 2013-2019.
15 Ashinuma H, Takiguchi Y, Kitazono S, et al. Antiproliferative action of metformin in human lung cancer cell lines[J]. Oncol Rep, 2012, 28(1): 8-14.
16 Storozhuk Y, Hopmans SN, Sanli T, et al. Metformin inhibits growth and enhances radiation response of non-small cell lung cancer (NSCLC) through ATM and AMPK[J]. Br J Cancer, 2013, 108(10): 2021-2032.
17 Teixeira SF, Guimarǎes Idos S, Madeira KP, et al. Metformin synergistically enhances antiproliferative effects of cisplatin and etoposide in NCI-H460 humanlung cancer cells[J]. J Bras Pneumol, 2013, 39(6): 644-649.
18 Wu N, Gu C, Gu H, et al. Metformin induces apoptosis of lung cancer cells through activating JNK/p38 MAPK pathway and GADD153[J]. Neoplasma, 2011, 58(6): 482-490.
(本文編輯:王亞南)
楊 翠,徐 瑜,胡義德. 二甲雙胍對肺腺癌耐厄洛替尼細(xì)胞株A549ER的耐藥逆轉(zhuǎn)作用[J/CD]. 中華肺部疾病雜志: 電子版, 2014, 7(5): 507-511.
Metformin reverses the resistance of erlotinib-resistant human lung adenocarcinoma cell line A549ER in vitro
YangCui1,XuYu2,HuYide1
(1DepartmentofOncology,XinqiaoHospital,ThirdMilitaryMedicalUniversity,Chongqing400037,China;2InstituteofRespitationDiseases,XinqiaoHospital,ThirdMilitaryMedicalUniversity,Chongqing400037,China)
HuYide,Email:huyide_mit@aliyun.com
Objective To detect the resistance reversal effects of metformin on erlotinib-resistant human lung adenocarcinoma cell line A549ER. Methods The human lung adenocarcinoma cell line A549 was defined as parental group. The erlotinib-resistant human lung adenocarcinoma cell line A549ER was set as blank group. A549ER treated with erlotinib alone was erlotinib group. A549ER treated metformin alone was metformin group. A549ER treated with erlotinib and metformin was combination group. The growth inhibitory effects of erlotinib on parental group A549 cell, erlotinib group A549ER cell and combination group A549ER cell were detected with CCK8 assay, and the half maximal inhibitory concentration (IC50), resistance index and reversal index were calculated. The cell cycle and cell apoptosis of blank group, erlotinib group, metformin group and combination group A549ER cell were detected with flow cytometry, and the proliferation index were calculated. Results The metformin inhibit growth of A549 and A549ER and the inhibition increased with increasing concentration. The IC50 of erlotinib on parental group A549 cell, erlotinib group A549ER cell and combination group A549ER cell were 15.15μmol/L, 118.8 μmol/L and 73.55μmol/L, respectively. The resistance index of erlotinib group A549ER cell and combination group A549ER cell were 7.84 and 4.85, respectively. The reversal index of metformin on the resistance of erlotinib was 1.62. The cell apoptosis rates of blank group A549ER cell, erlotinib group A549ER cell, metformin group A549ER cell and combination group A549ER cell were (5.53±3.00)%, (7.51±3.73)%, (10.25±4.23)% and (16.92±1.20)%, respectively. The cell apoptosis rate of combination group A549ER cell was significant higher compared with the other there groups (P<0.05). The proliferation index of blank group A549ER cell, erlotinib group A549ER cell, metformin group A549ER cell and combination group A549ER cell were 0.84±0.15, 0.78±0.10, 0.73±0.08 and 0.60±0.09, respectively. Conclusions A549ER has significant higher resistance of erlotinib compared with A549. The metformin reversed the resistance of erlotinib of A549ER. The metformin inhibited the cell proliferation, and promoted cell apoptosis in A549ER cells.
Lung adenocarcinoma; Metformin; Erlotinib; Resistance; Reversal
10.3877/cma.j.issn.1674-6902.2014.05.008
國家自然科學(xué)基金面上項目 (81372340)
1400037 重慶,第三軍醫(yī)大學(xué)新橋醫(yī)院腫瘤研究所2400037 重慶,第三軍醫(yī)大學(xué)新橋醫(yī)院呼吸研究所
胡義德, Email:huyide_mit@aliyun.com
R734
A
2014-06-26)