Low intensity ultrasound-induced apoptosis in human gastric carcinoma cells

AIM： To investigate the low intensity ultrasound （US）- induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. METHODS： Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry （FCM） with double staining of fiuorescein isothiocyanate （FITC）- Annexin V/propidium iodide （PI）. Two-dimensional electrophoresis （2DE） was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis. RESULTS： The percentage of apoptotic cells increased about 10% after US irradiation （12.0 W/cm^2, 12 h culture）, The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h.Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins （HSPs） were found to be associated with the signal process simulating the apoptosis of cells. CONCLUSION： Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum （ER） stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.

Paclitaxel induces apoptosis in human gastric carcinoma cells

AIM;To investigate the apoptosis in gastric cancer cells induced by paclitaxel,and the relation between this apoptosis and expression of Bcl-2 and Bax. METHODS:In in vitro experiments,MTT assay was used to determine the cell growth inhibitory rate.Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paclitaxel treatment.Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2 and Bax. RESULTS:Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner. Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics,including morphological changes of chromatin condensation,chromatin crescent formation,nucleus fragmentation and apoptotic body formation.Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2,and improve the expression of apoptosis-regulated gene Bax. CONCLUSION:Paclitaxel is able to induce the apoptosis in gastric cancer.This apoptosis may be mediated by down- expression of apoptosis-regulated gene Bcl-2 and up- expression of apoptosis-regulated gene Bax.

Growth-inhibiting and Apoptosis-inducing Effects of Tanshinone ⅡA on Human Gastric Carcinoma Cells

To explore the effects of Tanshinone Ⅱ A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone Ⅱ A on MKN-45 cells. The effect of Tanshinone Ⅱ A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide （PI） staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the ex- pression of p53 and bcl-2 gene after exposure to Tanshinone Ⅱ A in MKN-45 cells. The results showed that Tanshinone Ⅱ A significantly inhibited the growth and proliferation of MKN-45 cells in a dose- and time-dependent manner （P〈0.05）. Tanshinone Ⅱ A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of Go/G1 phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 lag/mL Tanshinone Ⅱ A for 96 h. It was also found that Tanshinone Ⅱ A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone Ⅱ A makes it a promising anticancer agent for the treatment of gastric carcinoma.

Genistein inhibits invasive potential of human hepatocellular carcinoma by altering cell cycle, apoptosis, and angiogenesis

AIM： To study the in vitro and in vivo inhibitory effects of genistein on invasive potential of Bel 7402 hepatocellular carcinoma （HCC） cells and to explore the underlying mechanism. METHODS： Bel 7402 HCC cells were exposed to genistein. The invasive activity of tumor cells was assayed in transwell cell culture chamber, p125^FAK expression and cell cycle were evaluated by a functional assay. Cell apoptosis analysis was performed with TUNEL method. In addition, bilateral subrenal capsule xenograft transplantation of HCC was performed in 10 nude mice. Genistein was injected and the invasion of HCC into the renal parenchyma was observed. Nicrovessels with immunohistochemical staining were detected. RESULTS： Genistein significantly inhibited the growth of Bel 7402 cells, the inhibitory rate of tumor cells was 26 -42%. The invasive potential of Bel 7402 cells in vitro was significantly inhibited, the inhibitory rate was 11- 28%. Genistein caused G2/M cell cycle arrest, S phase decreased significantly. The occurrence of apoptosis in genistein group increased significantly. The expression of p125^FAK in 5 μg/mL genistein group （15.26±0.16%） and 10 μg/mL genistein group （12.89±0.36%） was significantly lower than that in the control group （19.75± 1.12%, P〈0.05）. Tumor growth in genistein-treated nude mice was significantly retarded in comparison to control mice, the inhibitory rate of tumor growth was about 20%. Genistein also significantly inhibited the invasion of Bel 7402 cells into the renal parenchyma of nude mice with xenograft transplant. The positive unit value of microvessels in genistein-treated group （10.422 ±0.807） was significantly lower than that in control group （22.330 ± 5.696, P〈 0.01）. CONCLUSION： Genistein can effectively inhibit the invasive potential of Bel 7402 HCC cells by altering cell cycle, apoptosis and angiogenesis, inhibition of focal adhesion kinase may play a significant role in this process.

Blocking effects of genistein on cell proliferation and possible mechanism in human gastric carcinoma

AIM: To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism. METHODS: MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution. Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D_1, cyclin B_1 and p21^(waf1/cip1). RESULTS: Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901). Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 μg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7% respectively and cell cycles were arrested at the G(2)/ M phase. Genistein decreased cyclin D_1 protein expression and enhanced cyclin B_1 and p21^(waf1/cip1) protein expression in a concentration-dependent manner. CONCLUSION: The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle, with reduced expression of cyclin D_1 and enhanced expression of cyclin B_1 and p21^(waf1/cip1) protein in the concentration range of 0-20 μg/mL.

Cell cycle arrest and apoptotic cell death in cultured human gastric carcinoma cells mediated by arsenic trioxide

AIM: To investigate the effect of arsenic trioxide on human gastric cancer cell line MKN45 with respect to both cytotoxicity and induction of apoptosis in vitro. METHODS: MKN45 cells were treated with arsenic trioxide (As2O3) at the concentration of 1, 5, and 10 μmol/L, respectively, for three successive days. Cell growth and proliferation were observed by cell counting and trypan blue exclusion. Cytotoxicity of As2O3 was determined by MTT assay. Morphologic changes were studied with light microscopy. Flow cytometry was used to assay cell DNA distribution and apoptotic cells were confirmed with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and DNA electrophoresis. RESULTS: The growth of MKN45 cells was significantly inhibited by As2O3 which was confirmed by colony-forming assay. After 7 d of culture with various concentrations of As2O3, colony-forming capacity of MKN45 cells decreased with As2O3 increment in comparison with that of control group. The inhibitory rate of colony-formation was 38.5%, 99.1%, and 99.5% when the concentration of As2O3 was 1, 5, and 10 μmol/L in culture medium, respectively. The cell number of a single colony in drug treatment groups was less than that of control group. The cell-killing rate of As2O3 to MKN45 cells was both dose- and time-dependent with an IC50 of (11.05±0.25) μmol/L After incubation in 10 μmol/L As2O3 for 24 h, the cell-killing rate was 27.1%, and it was close to 50% after 48 h. The results showed that As2O3 induced time- and dose-dependent apoptosis in MKN45 cells, blocked at G2/M phase. The apoptotic peak (sub-G1 phase) appeared and cell apoptotic rate in MKN45 cells was 18.3-32.5% after treatment by 10 umol/L As2O3 for 48 h. The percentage of G2/M cell of the experimental groups was 2.0-5.0 times than that of the control group. Gel electrophoresis of DNA from cells treated with each concentration of As2O3 for 48 h revealed a 'ladder' pattern, indicating preferential DNA degradation at the internucleosomal, linker DNA sections. TUNEL also demonstrated strand breaks in DNA of MKN45 cells treated with As2O3, while control cells showed negative labeling. CONCLUSION: As2O3 can induce apoptosis of human gastric carcinoma cells MKN45, which is the basis of its effectiveness. It shows great potential in the treatment of gastric carcinoma.

Expression of E-selectin, integrinβ_1 and immunoglobulin superfamily member in human gastric carcinoma cells and its clinicopathologic significance

AIM： To study the expression levels of E-selectin, integrin β1 and immunoglobulin supperfamily memberintercellular adhesion molecule-1 （ICAM-1） in human gastric carcinoma cells, and to explore the relationship between these three kinds of cell adhesion molecules and gastric carcinoma. METHODS： The serum contents of E-selectin, integrin β1 and ICAM-1 were detected by enzyme-linked immunosorbent assay （ELISA）, in 47 healthy individuals （control group） and in 57 patients with gastric carcinoma （gastric carcinoma group） respectively prior to operation and 7 d after operation. RESULTS： The serum E-selectin, ECAM-1 and integrin β1 were found to be expressed in both control and gastric carcinoma groups. However, they were highly expressed in patients with gastric carcinoma patients before operation or with unresectable tumours. The expression levels of ICAM-1 and integrin β1 were significantly higher in gastric carcinoma patients than in controls （P 〈 0.01）. A comparison of the E-selectin levels between the two groups showed statistically insignificant differnce （P = 0.64）. In addition, the expression levels were all decreased substantially in the postoperative patients subjected to radical resection of the tumours, indicating that the high level expressions of these compounds might be the important factor for predicting the prognosis of these patients. CONCLUSION： Serum E-selectin, ICAM-1 and integrin β1 expression levels are probably related to the metastasis and relapse of gastric cancer.

siRNA of ADAM17 gene induces apoptosis,proliferation inhibition and enhances the effects of genistein on HepG2 cells

Objective：To investigate the effects of siRNA of ADAM17 gene and genistein on apoptosis and the inhibition of proliferation in HepG2 cells in an attempt to seek an effective therapy for hepatocellular carinoma. Methods：Cells were divided into control groups and experimental groups and siRNA was used to silence the ADAM17 gene, alone and in combination with genistein. Cells were harvested at several time periods and assessed for proliferation and apoptosis. Proliferation was assayed by MTT at 24, 48, 72 and 96 hours following treatment and apoptosis was assessed by flow cytometric analysis at 48 hours. Results：In siRNA groups, proliferation of cells was significantly inhibited compared to the control groups at 24, 48 and 72 hours（P 〈 0.05）, and apoptosis was significantly increased at 48 hours（P〈 0.01）; In genistein groups, proliferation was inhibited at 24, 48, 72 and 96 hours, and the apoptosis ratio was significantly increased at 48 hours（P〈 0.01）; while in the groups that received the combination of siRNA transfection and genistein treatment, there was a further significant decrease of proliferation and increase in apoptosis compared with either treatment alone. Conclusion：The ADAM17 gene could be an effective target, and genistein could be a useful agent, in the treatment of hepatocellular carcinoma, siRNA of ADAM17 gene and genistein both inhibited HepG2 cells proliferation and promoted apoptosis, and further, the combination of these treatments had a greater effect than either treatment alone.

Paris Saponin Ⅰ Induces G_2/M Cell Cycle Arrest and Apoptosis in Human Gastric Carcinoma SGC7901 Cells

The aim of this study was to investigate the effect of Paris saponin I （PSI ） on human gastric carcinoma cell growth and apoptosis and to explore the potential mechanisms. The proliferation of SGC7901 cells was monitored by the MTT cell viability assay, while the nuclear morphology of apoptotic cells was assessed by Hoechst 33258 staining. Flow cytometry was performed to analyze the cell cycle progression of propidium iodide （PI）-stained SGC7901 cells and the apoptotic rate of annexin V/PI-stained ceils. Western blotting was used to examine the expression of several cell cycle proteins, including cyclin 131 and Cdkl, and the apoptosis-regulated proteins Bcl-2, Bax, cytochrome c, procaspase-9, and procaspase-3. The MTT assay demonstrated that PSI could induce significant dose- and time-dependent inhibition of SGC7901 cell proliferation. Marked morphological changes, including condensation of chromatin, nuclear fragmentation and apoptotic bodies were clearly shown on Hoechst 33258 staining. PS I treatment also resulted in the disruption of the cell cycle at Gz/M and the induction of apoptosis. Following PSI treatment, the cell cycle-related proteins cyclin B 1 and Cdkl were down- regulated. Expression of the pro-apoptotic protein Bax was increased, while anti-apoptotic protein Bcl-2 decreased. PSI treatment resulted in elevated cytoplasmic cytochrome c and activation of the apoptotic proteases caspase-9 and caspase-3. These data indicate that PS I acts as an inhibitor of proliferation in SGC7901 cells by inducing cell cycle arrest and mitochondria-dependent apoptosis. PSI is a potential therapeutic agent against human gastric carcinoma.

Induction of apoptosis and G2/M cell cycle arrest by oridonin in human gastric cancer BGC-823 cells

Aim To investigate in vitro apoptosis-induction effects of oridonin on gastric tumor cells BGC-823 and its effects on cell cycle, mitochondrial membrane potential and intracellular Ca^2＋ to shed light on the mode of its anticancer action. Methods The MTT method was used to investigate the inhibitory effect of oridonin on BGC-823 cells. The apoptosis-induction effect was evaluated by confocal laser microscopy and flow cytometry. The change of mitochondrial membrane potential and the increase of intracellular Ca^2＋ were assessed by fluorescence probe rhodamine123 and Fluo 3-AM, respectively, with flow cytometry. The expression of apoptosis and cell cycle related proteins was studied using western blotting. Results Oridonin inhibited BGC-823 cells growth with IC50 of 22.21 p, mol.L^-1. It induced apoptosis in a dose-dependent manner. In addition, it decreased mitochondria membrane potential, increased intracellular Ca^2＋, and activated pro-caspase 3. BGC-823 cells were arrested in G2/M cell cycle phase with lower expression of cyclin A protein. The up-regulation of p53 was observed before apoptosis and cell cycle arrest occurred. Conclusion Oridonin inhibits the proliferation of BGC-823 cells through G2/M cell cycle arrest and apoptosis induction, which is mediated by influx of Ca^2＋, up-regulation of p53, activation of caspase-3, and down-regulation of cyclin A.

The Effect of Sodium Nitrite on Induction of Apoptosis in Human Gastric Adenocarcinoma Epithelia (AGS) Cells

To examine the cytocidal effect of sodium nitrite on the cancer cell, we subjected human gastric adenocarcinoma epithelia (AGS) cells to various experimentation following exposure to sodium nitrite, and measured the resulting changes in the levels of cell death, lactate dehydrogenase (LDH) release, and caspase-3, -6, -8, and -9 activities. Our data revealed that, in AGS cells, treatment with ≥6.25 mM sodium nitrite for 8 h resulted in an obvious increase in cell death. LDH release was also markedly increased following sodium nitrite treatment, but at a concentration of ≥6.25 mM for 24 h. This increasing trend showed a positive correlation (r = 0.9564, P < 0.05). In addition, we detected pronounced increases in caspase activities with various concentrations of sodium nitrite: caspase-3 at ≥25 mM for 1 h, ≥12.5 mM for 3 h and 6 h;caspase-9 at 50 mM for 1 h and 3 h, and ≥6.25 mM for 6 h;and caspase-6 at 50 mM for 1 h and 3 h. We did not however, detect any observable increase in the activity of caspase-8 following sodium nitrite treatment at any concentration or for any duration of treatment in this study. This data demonstrates that, in AGS cells, higher concentrations or longer durations of treatment with sodium nitrite could exhibit a cytocidal effect, and that sodium nitrite could induce apoptosis via activation of the caspase-9, caspase-3 cascade (intrinsic pathway) and caspase-6.

Genistein体外抑瘤效应及其对不同细胞作用选择性的研究

目的 研究Genistein与放射是否具有协同抑瘤作用及其毒副作用如何。方法 利用MTT法和集落计数研究Genistein对 5种不同细胞的选择性抗增殖作用 ,在此基础上运用活细胞计数、3H TdR掺入法、流式仪检测等技术分析Genistein和 /或放射对肿瘤细胞增殖的影响及可能的机制。结果 与对造血等正常细胞比较 ,Genistein对肿瘤细胞有较好的选择性 ;Genistein照后给药可引起明显的G2 M细胞周期阻滞 ,并诱发大量细胞凋亡 ,其抑瘤作用大于两单一措施之和 ,并显著高于照前给药组。结论 Genistein对骨髓造血细胞有着突出的安全低毒的优点 ,其照后给药与γ射线具有协同抑瘤效应。

Genistein对唾液腺腺样囊性癌细胞株SACC-83的体外抗增殖作用

目的:研究酪氨酸蛋白激酶抑制剂Genistein(4',5,7-三羟基异黄酮)对人唾液腺腺样囊性癌细胞株SACC-83的体外抗增殖作用及其对细胞增殖周期的影响。方法:用Genistein处理体外培养的SACC-83细胞,采用MTT检测法计算细胞存活率,显微照相记录细胞生长状态及形态学的改变,流式细胞仪测定细胞周期,AnnexinⅤ/PI法定量检测细胞凋亡,采用SPSS11.5统计软件对结果进行统计方差分析。结果:Genistein对SACC-83细胞有一定的抗增殖作用,且当其作用到一定时间、达到一定的浓度后,该作用与浓度及时间呈依赖关系;细胞形态发生改变,体积缩小,悬浮细胞逐渐增多;SACC-83细胞经220μmol/LGenistein作用3d,其生长受到明显抑制,阻断细胞生长于G2/M期,并明显诱导细胞凋亡(P<0.01)。结论:Genistein可以显著抑制人唾液腺腺样囊性癌细胞株SACC-83的生长,阻断细胞周期于G2/M期,并诱导细胞凋亡;提示酪氨酸蛋白激酶在唾液腺腺样囊性癌的发生、发展中起着重要作用。

Genistein对腺样囊性癌细胞SACC-83中细胞凋亡相关蛋白表达的影响

目的:研究酪氨酸蛋白激酶抑制剂Genistein诱导人唾液腺腺样囊性癌细胞株SACC-83细胞凋亡的分子机制。方法:用Genistein处理体外培养的SACC-83细胞,采用Western印迹技术检测bax、bcl-2和survivin蛋白的表达,并利用电泳凝胶成像分析软件,对其结果进行量化分析,采用SPSS11.5软件包对结果进行方差分析。结果:随着Genistein作用时间的延长和浓度的增加,bax蛋白的表达明显增加,bcl-2和survivin蛋白的表达明显减少。SACC-83细胞经220μmol/LGenistein作用3d,其bax蛋白的表达量是对照组的3.43倍(P<0.01),而bcl-2和survivin蛋白的表达量分别是对照组的85%(P<0.05)和35%(P<0.01)。结论:Genistein诱导SACC-83细胞凋亡,与其上调bax蛋白的表达,以及下调bcl-2和survivin蛋白的表达有关。

Growth inhibition and apoptosis induction Sulindac on Human gastric cancer cells

AIM: To evaluate the effects of sulindac in inducing growth inhibition and apoptosis of human gastric cancer cells in comparison with human hepatocellular carcinoma (HCC) cells. METHODS: The human gastric cancer cell lines MKN45 and MKN28 and human hepatocellular carcinoma cell lines HepG(2) and SMMC7721 were used for the study. Anti-proliferative effect was measured by MTT assay, and apoptosis was determined by Hoechst-33258 staining, electronography and DNA fragmentation. The protein of cyclooxygenase-2 (COX-2) and Bcl-2 were detected by Western dot blotting. RESULTS: Sulindac could initiate growth inhibition and apoptosis of MKN45, MKN28, HepG(2) and SMMC7721 cells in a dose-and time-dependent manner. Growth inhibitory activity and apoptosis were more sensitive in HepG(2) cells than in SMMC7721 cells, MKN45 and MKN28 cells. After 24 hours incubation with sulindac at 2mmol x L(-1) and 4mmol x L(-1), the level of COX-2 and Bcl-2 protein were lowered in MKN45, SMMC7721 and HepG(2) cells but not in MKN28 cells. CONCLUSION: Sulindac could inhibit the growth of gastric cancer cells and HCC cells effectively in vitro by apoptosis induction, which was associated with regression of COX-2 and Bcl-2 expression. The growth inhibition and apoptosis of HCC cells were greater than that of human gastric cancer cells. The different effects of apoptosis in gastric cancer cells may be related to the differentiation of the cells.

Expression of Bcl-2 inhibited Fas-mediated apoptosis in human hepatocellular carcinoma BEL-7404 cells

Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of "Death factor" family, the transfection experiments with expression vectors pcDNA3-fl and pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl-2. The data showed that the expression of FasL in pcDNA3-fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3-bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fl transient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hepatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.

Genistein对人尿道鳞癌细胞增殖和凋亡的影响

目的 观察Genistein(GEN)对人尿道鳞癌细胞系HUS 98细胞增殖和凋亡的影响。方法 MTT法检测细胞增殖 ,碘化丙啶 (PI)和AnnexinV FITC双染色的流式细胞分析方法检测凋亡 ,台盼蓝拒染法测定淋巴细胞活力 ,免疫细胞化学检测雌激素受体 (ER)蛋白的表达。结果 低浓度 (1× 10 11～ 1× 10 8mol/L)GEN促进HUS 98细胞的生长 ,处理 3d时 ,1× 10 8mol/L组的细胞数比对照组的增加 9% (P <0 .0 1) ;高浓度 (1× 10 7mol/L～ 5× 10 4mol/L)GEN则浓度依赖性地引起HUS 98细胞数目逐日减少 ,但是除 5× 10 4mol/L外的其余浓度对正常淋巴细胞的生长没有影响。 1× 10 6mol/LGEN作用于HUS 98细胞 2 4～ 4 8h ,凋亡细胞和坏死细胞的比率均增加 ,且有时间依赖性。HUS 98细胞表达ER蛋白。结论 高浓度GEN具有抑制ER阳性的人尿道鳞癌细胞的生长和诱导凋亡及坏死的作用 ,为今后用于尿道鳞癌的治疗提供了实验依据。

18β-glycyrrhetinic Acid-induced Apoptosis and Relation with Intracellular Ca^2＋ Release in Human Breast Carcinoma Cells

Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.

Effect of heparin on apoptosis in human nasopharyngeal carcinoma CNE2 cells

In order to study the mechanism of the effect of heparin on apoptosis in carcinoma cells, the nasopharyngeal carcinoma cell line CNE2 was used to identify the effect of heparin on apoptosis associated with the expression of c-myc, bax, bcl-2 proteins by use of Hoechst 33258 staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), agarose gel electrophoresis, and flow cytometry, as well as Western blot analysis. The results showed that heparin induced apoptosis of CNE2 cells including the morphologic changes such as reduction in the volume, and the nuclear chromatin condensation, as well as the 'ladder pattern' revealed by agarose gel electrophoresis of DNA in a concentration-dependent manner. The number of TUNEL-positive cells was dramatically increased to 33.6+/-1.2% from 2.8+/-0.3% by treatment with heparin in different concentrations (10 to approximately 40 kU/L). The apoptotic index was increased to 32.5% from 3.5% by detecting SubG1 peaks on flow cytometry. Western blot analysis showed that levels of bcl-2, bax and c-myc were significantly overexpressed by treatment with the increase of heparin concentrations. These results suggest that heparin induces apoptosis of CNE2 cells, which may be regulated by differential expression of apoptosis-related genes.

Effect of amlodipine on apoptosis of human breast carcinoma MDA-MB-231 cells

Objective： To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods： Light microscopy was used to determine the effects of amlodipine on cell morphology; Flow cytometry was used to quantitate cells undergoing apoptosis; the expression of a cell cycle-related protein, proliferating cell nuclear antigen （PCNA） and an antiapoptosis protein, Bcl-2 were assessed by immunocytochemistry. Results： Amlodipine concentration of 8.25umol/L （1/2 of ICs0） affected the morphology, decreased the expression of PCNA and Bcl-2 and induced apoptosis of human breast carcinoma MDA-MB-231 cells. Conclusion： The effect of amlodipine on the antiproliferation of human breast carcinoma MDA-MB-231 cells is related to inducement of apoptosis, and the decrease of the expression of Bcl-2 and PCNA may be the possible mechanism for proliferation inhibitory and inducement of apoptosis.