中藥複方PC—SPES Ⅱ抑製人前列腺癌細胞LNCaP增殖及其對AR, PSA表達的影響
藥理
作者:張碧嚴等
[摘要] 基於雄激素受體(AR)信號通路探討中藥複方PC-SPES Ⅱ抑製人前列腺癌細胞LNCaP增殖的作用。采用MTT法檢測PC-SPES Ⅱ對LNCaP細胞增殖的影響,顯示PC-SPES Ⅱ質量濃度為180~1 440 mg·L-1時能顯著抑製LNCaP細胞增殖,PC-SPES Ⅱ作用24,48 h的IC50分別為311.48,199.01 mg·L-1;流式細胞儀檢測細胞周期分布的變化發現240 mg·L-1 PC-SPES Ⅱ能阻滯細胞於G2/M期,在G0/G1峰前出現明顯的凋亡峰,隨作用時間的增加而升高;同時采用Hoechst 33258染色觀察凋亡細胞形態和Annexin V-FITC/PI雙染流式細胞儀檢測凋亡細胞比例,PC-SPESⅡ質量濃度為480 mg·L-1時凋亡細胞比率增加,作用效果均呈一定劑量依賴性;通過ELISA法檢測LNCaP細胞分泌PSA的水平,以25 mg·L-1 Bic作為陽性對照藥,發現480 mg·L-1PC-SPES Ⅱ能顯著降低細胞分泌PSA;采用qRT-PCR和Western blot方法檢測AR,PSA mRNA和蛋白表達的變化,結果顯示以人工合成雄激素25 μg·L-1R1881誘導LNCaP細胞後,240~480 mg·L-1 PC-SPES Ⅱ能顯著下調AR,PSA mRNA和蛋白表達,抑製AR由細胞質轉移入細胞核。以上結果表明,PC-SPES Ⅱ對LNCaP細胞體外增殖有抑製作用,阻滯細胞周期於G2/M期並誘導細胞凋亡,其機製可能與下調AR,PSA的表達,抑製AR核轉位有關。
[關鍵詞] 前列腺癌;PC-SPES Ⅱ;LNCaP細胞;抑製增殖;雄激素受體;前列腺特異性抗原
[Abstract] To investigate the effect of compound Chinese traditional medicine PC-SPES Ⅱ I in inhibiting proliferation of human prostate cancer cell LNCaP based on the androgen receptor (AR) signaling pathway. The effect of PC-SPES Ⅱ on LNCaP cell proliferation was detected by MTT assay. According to the findings, at the mass concentration of 180-1 440 mg·L-1, PC-SPES Ⅱ significantly inhibited the proliferation of LNCaP cells; the IC50 of PC-SPES Ⅱ at 24 h and 48 h were 311.48, 199.01 mg·L-1, respectively. The flow Cytometry detection showed 240 mg·L-1 PC-SPES Ⅱ arrested cells in G2/M phase, and an obvious apoptotic peak appeared before G0/G1 peak and rose over time. Meanwhile, Hoechst 33258 staining revealed apoptotic cellular morphology. Annexin V-FITC/PI staining manifested an increase in apoptotic cell ratio at the PC-SPES Ⅱ concentration of 480 mg·L-1 in a dose dependent manner. The prostate specific antigen (PSA) secretion of LNCaP cells was tested by PSA ELISA kit. Besides, compared with 25 mg·L-1 Bic, 480 mg·L-1 PC-SPES Ⅱ significantly reduced the cell secretion of PSA. The AR and PSA mRNA and protein expressions were detected by qRT-PCR and Western blot. According to the results, after the induction of LNCaP cells with synthetic androgen 25 μg·L-1 R1881, 240-480 mg·L-1 PC-SPES Ⅱ _disibledevent=(A實驗組-A空白組)/(A陰性對照組-A空白組)×100%。
2.4 流式細胞儀檢測細胞周期分布 取對數生長期的LNCaP細胞經胰酶消化後, 以5×105個/孔的細胞數接種於6孔板中,每孔2 mL。待細胞貼壁後,陰性對照組加入含0.1%乙醇的培養液,實驗組加入終質量濃度為240 mg·L-1 PC-SPES Ⅱ,分別於37 ℃,5%CO2培養箱中培養0,12,24,48 h後,消化收集細胞,用預冷PBS洗1次,加入預冷70%乙醇固定細胞,4 ℃過夜。離心棄上清,用預冷PBS洗1次,加入0.5 mL PI/RNase Staining Buffer,室溫孵育15 min。使用流式細胞儀檢測細胞周期分布。
2.5 Hoechst 33258染色觀察凋亡細胞形態 取對數生長期的LNCaP細胞經胰酶消化後, 以1×105個/孔的細胞數接種於24孔板中,每孔1 mL。待細胞貼壁後,陰性對照組加入含0.1%乙醇的培養液,實驗組加入終質量濃度為480 mg·L-1 PC-SPES Ⅱ,分別於37 ℃,5%CO2培養箱中培養0,12,24,48 h後,棄培養上清,用預冷PBS洗1次,加入預冷95%乙醇固定細胞,4 ℃過夜。棄固定液,用預冷PBS洗2次,加入Hoechst 33258,37 ℃染色15 min,用預冷PBS洗2次,於倒置熒光顯微鏡下觀察拍照。
2.6 Annexin V-FITC/PI雙染流式細胞儀檢測細胞凋亡 取對數生長期的LNCaP細胞經胰酶消化後, 以5×105個/孔的細胞數接種於6孔板中,每孔2 mL。待細胞貼壁後,陰性對照組加入含0.1%乙醇的培養液,實驗組加入終質量濃度為480 mg·L-1 PC-SPES Ⅱ,分別於37 ℃,5%CO2培養箱中培養0,24,48 h後,胰酶(不含EDTA)消化收集細胞,用預冷PBS洗2次,重懸細胞於Binding buffer中,按照試劑盒說明加入Annexin V-FITC和PI各5 μL,室溫孵育15 min。使用流式細胞儀檢測細胞凋亡率,其中Annexin V陽性,PI陰性代表早期凋亡細胞,Annexin V陽性,PI陽性代表晚期凋亡細胞。
2.7 ELISA法測定細胞分泌PSA水平 取對數生長期的LNCaP細胞經胰酶消化後, 分別以1×105個/孔細胞傳於24孔板中,每孔1 mL。待細胞貼壁後,陰性對照組加入含0.1%乙醇的培養液,陽性對照組加入終質量濃度為25 mg·L-1Bic,實驗組加入終質量濃度為480 mg·L-1PC-SPES Ⅱ,培養0,12,24,48 h後,分別收集每孔細胞培養上清,按照人前列腺特異性抗原ELISA試劑盒說明操作,多功能酶標儀在450 nm處檢測吸光度A。
2.8 qRT-PCR檢測細胞AR,PSA mRNA的表達 取對數生長期的LNCaP細胞經胰酶消化後, 以5×105個/孔的細胞數接種於6孔板中,每孔2 mL。待細胞貼壁後,陰性對照組加入含0.1%乙醇的培養液,實驗組均加入終質量濃度25 μg·L-1R1881,分別加入終質量濃度為240,480 mg·L-1 PC-SPES Ⅱ或25 mg·L-1 Bic,於2%FBS RPMI-1640中培養24 h後,消化收集細胞。按照Trizol試劑說明提取細胞總RNA,所提取的RNA用NanoDrop 2000(美國Thermo公司)測定濃度,並根據A260/A280(1.8~2.0)確定總RNA提取的純度。根據RNA濃度取1 μg RNA逆轉錄,合成cDNA,所得逆轉錄產物用於PCR擴增。通過Primer-Blast和Primer Premier 5.0設計引物,引物序列及擴增產物長度,引物由上海生工合成。qPCR反應條件為95 ℃預變性10 s;95 ℃變性15 s,60 ℃退火60 s,72 ℃延伸30 s,40個循環。β-actin作為內參基因,目的基因的相對表達量根據2-ΔΔCt計算,同時參考溶解曲線確保擴增產物的特異性。