Effects of histamine on growth and apoptosis of human melanoma cells A375

Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis by double staining with Annexin V-FITC and PI, and active caspase-3 analysis by staining FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. StreptAvidin-Biotin Complex (SABC) immunocytochemical assays were adopted to detect Bax/Bcl-2 protein expressions.Results: Histamine inhibited proliferation of A375 cells in a dose- and time-dependent manner, and altered cell cycle distribution of A375 cells revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. Histamine induced apoptosis of A375 cells (P<0.05), elevated the cells population with detectable active caspase-3 (P<0.05), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (P<0.05). Conclusion: That histamine inhibits cell cycle progress of A375 cells is one of the possible mechanisms of proliferation arrest of A375 cells elicited by histamine. Histamine mediates apoptosis in A375 cells that may be caspase-dependent through mitochondria routine. Histamine with high concentration inhibits growth of A375 cells in vitro by interfering proliferation and inducing apoptosis of cells.

In-Vitro Inhibition of Human Melanoma (BLM) Cell Growth by Progesterone Receptor Antagonist RU-486 (Mifepristone)

RU-486 is an abortifacient which is used to terminate early pregnancy. It acts by blocking progesterone receptor. In our earlier study with progesterone, RU-486 was used as a progesterone receptor antagonist to find out the mechanism of progesterone action on melanoma cells. Results indicated that the effect of progesterone was not mediated through progesterone receptor. In the course of experiments, it was observed that RU-486 by itself inhibited mouse melanoma cell growth. Further research work with RU-486 showed a dose dependent inhibition of human melanoma cell growth. The mechanism of inhibition of cell growth was due to apoptosis and this effect of RU-486 was neither mediated through progesterone receptor nor glucocorticoid receptor. This in-vitro study suggested that melanoma also could be a target for RU-486 action, apart from breast, ovary and prostate cancers.

Apoptotic Effect of Cryptotanshinone on Human Melanoma A375 Cells

[Objectives] The aim was to investigate the effect of cryptotanshinone on apoptosis of human melanoma A375 cells and its related mechanism of mitochondrial pathway.[Methods]The cytotoxic effect of cryptotanshinone on apoptosis of human melanoma A375 cells was detected by MTT colorimetry.The apoptosis of melanoma A375 cells was detected with Annexin V-FITC/PI and observed by fluorescence inverted microscope.The expression of apoptosis-related proteins was detected by Western blotting.[Results]The viability of the A375 cells decreased with the increase of drug concentration.The fluorescence intensity of the cells increased with the treatment time.The expression of pro-apoptotic protein caspase-3 gradually increased,while the expression of apoptosis-inhibiting proteins p-AKT and Bcl-2 gradually reduced.[Conclusions]Cryptotanshinone induces apoptosis of human melanoma A375 cells via AKT signaling pathway,thus exerting a good cytotoxic effect on A375 cells.

Effect of luteolin on apoptosis and vascular endothelial growth factor in human choroidal melanoma cells

AIM:To investigate the effects of luteolin on apoptosis,the cell cycle,and the expression and secretion of vascular endothelial growth factor(VEGF)in human choroidal melanoma cells(C918 and OCM-1).METHODS:C918 and OCM-1 cells cultured in vitro were treated with various concentrations of luteolin(0,5,10,15μmol/L).Cell growth was observed with an inverted microscope,and cell cycle arrest was detected by propidium iodide(PI)staining using flow cytometry.Apoptosis was detected by Hoechst33342 staining,and apoptosis rate was determined by Annexin V-FITC/PI experiments using flow cytometry.The expression of apoptosis-related proteins Bcl-2,Bax and VEGF was analyzed using Western blots.The levels of VEGF secreted by the cells into the supernatant was analyzed using ELISA.RESULTS:After treating with 5 to 15μmol/L luteolin for 48 h,the fusion degree of C918 and OCM-1 cells decreased,and more floating apoptotic cells appeared.Luteolin treatment increased the G0-G1 phase ratio of the C918 and OCM-1 cells,blocked cell cycle progression,and increased the apoptosis rate of the C918 and OCM-1 cells.Western blot showed that luteolin decreased the expression of Bcl-2 and VEGF in the C918 and OCM-1 cells and increased the expression of Bax protein.The ELISA results showed that 10 to 15μmol/L luteolin decreased the cell secretion of VEGF.CONCLUSION:Luteolin may induce apoptosis by regulating the levels of apoptosis-related proteins in C918 and OCM-1 cells.Luteolin can induce cell cycle arrest,decrease the expression of VEGF.

Construction of Luffin A Immunotoxin and Its in vitro Inhibition Against Human Melanoma Cell M_(21)

1 Introduction In recent years, significant progress has been made in applying immunotoxin (IT)in the therapy of leukemia and marrow transplantation. By 1990, several ITs havebeen put into clinical trials under the permission of FDA (Foodand Drug Administration, USA).

ETM study of electroporation influence on cell morphology in human malignant melanoma and human primary gingival fibroblast cells

Objective:To estimate electroporation(EP) influence on malignant and normal cells.Methods: Two cell lines including human malignant melanoma(Me-43) and normal human gingival fibroblast(HCFs) were used.EP parameters were the following:230,1000,1 730,2 300 V/cm;30 μ s by 3 impulses for every case.The viability of cells after EP was estimated by MTT assay. The ullrastructural analysis was observed by transmission electron microscope(Zeiss EM 900). Results:In the current study we observed the intracellular effect following EP on Me-43 and HGF cells.At the conditions applied,we did not observe any significant damage of mitochondrial activity in both cell lines treated by EP.Conversely,we showed that EP in some conditions can stimulate cells to proliferation.Some changes induced by EP were only visible in electron microscopy.In fibroblast cells we observed significant changes in lower parameters of EP(230 and 1 000 V/cm).After applying higher electric field intensities(2 300 V/cm) we detected many vacuoles,myelin-like bodies and swallowed endoplasmic reticulum.In melanoma cells such strong pathological modifications after EP were not observed,in comparison with control cells. The ultrastructure of both treated cell lines was changed according to the applied parameters of EP.Conclusions:We can claim that EP conditions are cell line dependent.In terms of the intracellular morphology,human fibroblasts are more sensitive to electric field as compared with melanoma cells.Optimal conditions should be determined for each cell line.Summarizing our study,we can conclude that EP is not an invasive method for human normal and malignant cells. This technique can be safely applied in chemotherapy for delivering drugs into tumor cells.

Up-regulation of Human Leukocyte Antigen G Expression in Primary Cutaneous Malignant Melanoma Associated with Host-vs-tumor Immune Response

Human leukocyte antigen G （HLA-G） is one of the molecules implicated in immunotolerance. To investigate the role of HLA-G in primary cutaneous malignant melanoma （CMM）, a series of 47 skin melanocytic lesions were immunohistochemically evaluated. The correlation between HLA-G expression and CMM clinicohistopahtological data and Bcl-2 expression was also analyzed. HLA-G expression was detected in a variety of cell types. No significant difference in HLA-G expression was observed between malignant and non-malignant melanocytic lesions. HLA-G expression was significantly correlated with the inflammatory infiltration and Bcl-2 expression, whereas no significant correlation with ulceration, tumor thickness, clinical stage, histopathological subtypes were observed. HLA-G expression may be the result of host immune reaction in tumor microenvironment rather than a malignant feature of CMM.

Radioiodide uptake in melanoma cells after transfer of human NaI symporter gene

To obtain human sodium/iodide symporter gene cDNA for studying its potential ability as a radioiodide treatment for melanoma, the hNIS gene cDNA was amplified with total RNA from human thyroid tissue by RT-PCR. The hNIS cDNA was inserted into cloning vector pUCm-T and subcloned into eukaryotic expression vector pc-DNA3. The pc-DNA3-hNIS and pc-DNA3 were transduced into melanoma cells (B16) by electroporation, and two cell lines termed B16-A and B16-B respectively were established. The uptake and efflux of iodide was examined in vitro. The three cell lines (B16-A, B16-B, B16) were injected subcutaneously into the right flank of C57 mice. Biodistribution study and tumor imaging were performed when the tumor reached approximately 10mm in diameter. The cloned hNIS cDNA sequence was identical with the published sequence. Two novel cell lines named 16-A containing pc-DNA3-hNIS and B16-B containing pc-DNA3 only were established. The resultant cell line B16-A accumulated 17 and 19 times more radioiodide in vitro than B16 and B16-B respectively. The iodide uptake reached the half-maximal level within 10 min, and reached a plateau at 30 min. The efflux of iodide was also rapid (T1/2eff=10min). The imaging shows in vivo uptake in expected sites including the salivary glands, thyroid, stomach, and hNIS-transduced tumor, whereas the nontransduced tumor was not visualized. The %ID/g of B16-A tumors at 1, 2, 4, 12, and 24h after injec- tion of 125I were 12.22±0.71, 10.91±0.72, 8.73±0.99, 1.24±0.29, and 0.19±0.03, respectively, which were signifi- cantly higher percentages than those for controlling tumors, p<0.01. However, biologic T1/2 was about 6 h. Our pre- liminary data indicate that the transduction of the hNIS gene per se is sufficient to induce iodide transport in mela- noma cells both in vitro and in vivo, but T1/2eff is short.

人胎儿真皮间充质干细胞对人恶性黑色素瘤细胞增殖、迁移、侵袭的抑制作用观察

目的 观察人胎儿真皮间充质干细胞(FDMSCs)对人恶性黑色素瘤细胞(A375细胞)增殖、迁移、侵袭的抑制作用。方法 通过酶消化法从16~20孕周的人意外流产健康胎儿的背部皮肤中提取FDMSCs,并进行鉴定。选取A375细胞并分为3组,F-CM组加入FDMSCs条件培养基,A-CM组加入成人真皮成纤维细胞条件培养基,Control组加入DMEM低糖空白培养基,利用CCK-8细胞增殖实验、划痕细胞迁移实验、细胞侵袭实验测算各组细胞相对活力、细胞迁移率、侵袭细胞数。结果 FDMSCs可以从人胎儿皮肤中成功提取并体外培养,阳性表达间充质干细胞(MSCs)特异性标记CD44、CD90、CD105及胚胎组织特异性标记SSEA-4、OCT-4,且具备成脂、成骨、成软骨的多向分化能力。与Control组比较,F-CM组细胞相对活力下降,细胞迁移率低,侵袭细胞数少(P均<0.05)。结论 FDMSCs可抑制A375细胞的增殖、迁移和侵袭。

紫铆花素对人黑色素瘤细胞A375与人永生化角质形成细胞HaCaT共培养细胞生物学活性的影响

目的探讨紫铆花素对人黑色素瘤细胞A375与人永生化角质形成细胞HaCaT共培养细胞生物学活性的影响。方法建立A375细胞与HaCaT细胞的共培养细胞体系,实验分为对照组(等体积培养液),紫铆花素低、中、高剂量组(以下简称低、中、高剂量组,0.5,1.0,5.0μg/L)。采用四甲基偶氮噻唑蓝(MTT)法检测细胞活性;采用流式细胞仪检测细胞的周期分布和线粒体膜电位;采用实时荧光定量聚合酶链反应(qPCR)法检测干细胞因子(SCF)和其受体c-Kit,以及小眼畸形相关转录因子(MITF)的mRNA表达水平;采用Western blot法检测细胞酪氨酸酶相关蛋白1,2(TRP-1,TRP-2)及SCF,c-Kit,MITF的蛋白表达水平。结果与对照组比较,中、高剂量组细胞的增殖率均显著升高(P<0.01);与对照组比较,各剂量组G0/G1期细胞比例均显著降低,S期和G_(2)/M期细胞比例均显著升高(P<0.01),高线粒体膜电位细胞比例均显著升高(P<0.05或P<0.01),SCF,c-Kit,MITF的mRNA表达水平及SCF,c-Kit,MITF,TRP-1,TRP-2的蛋白表达水平均显著升高(P<0.05或P<0.01)。结论紫铆花素可能通过调节SCF,cKit,MITF的表达而影响A375细胞与HaCaT细胞共培养细胞的增殖、细胞周期和线粒体膜电位等细胞生物学活性。

Expression of the Tumor Metastatic Suppressor Gene in Mouse Melanoma Model: Inverse Association to Metastatic Potential

Data obtained in experimental cutaneous melanomas have suggested that the nm23 gene may function as a metastasis suppressor gene. The nm23 level in 8 human cutaneous melanoma cell lines and 2 murine melanoma cell lines were examined. Each melanoma cell line was transplanted subcutaneously into the flank of nude mice, and the metastatic behavior was evaluated by counting lung tumor fool and by determining host survival time. It was found that expression of 'm23 mRNA in human melanomas is correlated closely with reduced metastatic behavior in experimental animals and may serve as a sensitive prognostic indicator of malignancy and survival in patients with melanomas.

Significance of aberrant melanosomes in the diagnosis of malignant melanoma

In order to clarify the significance of the aberrant melanosomes in thediagnosis of malignant melanoma,17 cases of malignant melanoma were studied with elec-tron microscopy,and 30 cases of nevus were studied likewise for comparison.Aberrantmelanosomes were present in 12 cases of pigmented and 2 cases of amelanotic malignantmelanoma.They were also found in 4 cases of congenital nevus.The findings suggest thatthe presence of aberrant melanosomes is of significance for the diagnosis of malignantmelanoma but this has been overemphasized.It is believed that the diagnosis of malignantmelanoma depends upon a comprehensive judgement of all the ultrastructural findings un-der electron microscopy.

Human Multipotent Stem Cell Proteins Induce Apoptosis in Skin Cancer Cells

Unique characteristics in fetal development include scar-less wound healing and the paucity of tumor formation. Recent studies have demonstrated that the embryonic microenvironment can reverse melanoma cells to a benign melanocyte phenotype. We bioengineered embryonic-like compositions and tested the anti-cancer activity of this material on a panel of skin cancer lines. To simulate the embryonic environment, neonatal fibroblasts were grown in hypoxic suspension cultures. The cells reverted back into multipotent stem cells as evidenced by the upregulation of SOX2, Oct4, NANOG, and KLF4 genes, and by the expression of stem cell-associated proteins including Nodal, Brachyury, Nestin, and Oct4. Cell Conditioned Media (CCM) and human Extracellular Matrix Proteins (hECM) produced by these cells were tested for their ability to reduce cell viability in skin cancer cell lines. In vitro studies with CCM and hECM show reduction in Squamous Cell Carcinoma (SCC), Basal Cell Carcinoma (BCC) and melanoma cell number through upregulation of caspases and induction of apoptosis. In the chick allantoic membrane assay, melanoma load was reduced by up to 80% with hECM treatment compared to vehicle treated controls (p 0.05). Similar inhibition was seen with SCC cells. In a xenograft mouse model of subcutaneous melanoma, tumor growth was inhibited by 70% - 90%. These data suggest that CCM and hECM have anti tumor potential and might offer a new treatment strategy in skin cancer.

质子辐射对人恶性黑色素瘤A375细胞的DNA损伤影响研究

为研究质子辐射对人恶性黑色素瘤的杀伤效应,本研究利用北京HI-13串列加速器提供的15 MeV质子,以0、1、2、4、8 Gy剂量辐照A375细胞,以细胞克隆术和流式细胞术检测A375细胞的克隆形成率、周期阻滞及凋亡率,用免疫荧光法检测2 Gy辐照后细胞的γH2AX焦点数,并与相同条件下的γ射线辐射对比。结果表明,在1~8 Gy剂量下,随着剂量的增加,A375细胞的存活率下降,在4~8 Gy剂量下,细胞的存活率明显低于γ射线。辐照后12 h,细胞G2/M期阻滞随剂量的增加而增加,质子辐射诱导的周期阻滞强于γ射线;辐照后48 h,γ射线诱导的细胞周期阻滞已基本解除,但质子诱导的细胞周期阻滞除1 Gy外,2~8 Gy均未完全解除。辐射诱导的细胞凋亡随照射剂量的增加而增加,随着时间的延长,凋亡比例有所增加,且质子诱导的细胞凋亡率高于γ射线。辐照2 Gy后,γ射线和质子诱导的γH2AX焦点峰值均在照后1 h出现,质子辐射诱导的γH2AX焦点数和大小均高于γ射线。以上结果表明,质子辐射可有效杀伤恶性黑色素瘤A375细胞,在黑色素瘤治疗中有潜在应用价值。

贝伐单抗对人眼脉络膜黑色素瘤MUM-2B细胞血管生成拟态的影响

目的:通过体内外实验探讨贝伐单抗对人眼脉络膜黑色素瘤细胞(MUM-2B)血管生成拟态的影响及可能相关的分子通路。方法:通过不同浓度的贝伐单抗(0,0.1,1,2,3 mg/mL)处理MUM-2B细胞,观察其对MUM-2B细胞成管能力的影响。通过CCK-8法及Transwell法检测其对MUM-2B细胞增殖及侵袭的影响。然后,建立裸鼠皮下移植瘤模型,通过不同剂量的贝伐单抗(5 mg/kg,7.5 mg/kg,10 mg/kg)干预,探究贝伐单抗对裸鼠皮下移植瘤VM形成的影响,并通过CD31/PAS免疫组化双重染色法检测VM的表达情况,免疫组化法检测HIF-1a、VE-cadherin、EphA2、PI3K蛋白表达水平变化。结果:体外实验中,不同浓度的贝伐单抗(0,0.1,1,2,3 mg/mL)处理MUM-2B细胞24小时后,对MUM-2B细胞的成管能力、增殖、侵袭能力并没有表现出明显的抑制或促进作用。实验组与对照组相比差异无统计学意义(P>0.05)。在体内实验中,贝伐单抗实验组(5 mg/kg,7.5 mg/kg,10 mg/kg)与对照组相比较能显著的促进MUM-2B细胞形成VM的能力(P<0.05),且形成管道的数量与贝伐单抗的浓度呈正相关(r=0.942,P<0.05)。实验组HIF-1a、VE-cadherin、EphA2和PI3K-Akt蛋白的表达水平均明显高于对照组(P<0.05),且各分子的表达量随着贝伐单抗浓度的升高呈浓度依赖性的升高。结论:体外实验中,贝伐单抗对MUM-2B细胞的成管能力,增殖,侵袭能力并没有表现出明显的抑制或促进作用。体内实验中,贝伐单抗的使用能促进HIF-1a的表达、上调VE-cadherin/EphA2/PI3K-Akt后续的级连信号通路,从而加速VM的生成。

木犀草素对脉络膜恶性黑色素瘤细胞的影响

为探讨木犀草素调节Wnt/β-catenin信号通路对人脉络膜恶性黑色素瘤细胞(MuM-2C)凋亡、迁移和侵袭的影响,采用CCK 8法测定0,5,10,15,20,25μmol/L浓度木犀草素处理24 h后的MuM-2C活力,以筛选合适的药物作用浓度.将体外培养的MuM-2C随机分为3组:对照组、木犀草素组及木犀草素+氯化锂组,木犀草素组以15μmol/L木犀草素处理,木犀草素+氯化锂组以15μmol/L木犀草素和10μmol/L的氯化锂联合处理.采用流式细胞技术和Hoechst 33258染色检测MuM-2C的凋亡情况,采用划痕实验和Transwell实验检测各组MuM-2C的迁移、侵袭情况,采用免疫荧光检测各组MuM-2C中凋亡蛋白BAX与BCL-2表达,采用免疫印记检测各组MuM-2C中EMT标志蛋白(E-cadherin,N-cadherin,Vimentin)和Wnt/β-catenin信号相关蛋白(Wnt1,β-catenin)表达,结果表明:不同剂量木犀草素均可抑制MuM-2C生长,并在一定范围内随剂量升高而作用增强;与对照组比较,木犀草素组细胞核形态固缩而大小不一,着色不均匀,部分呈现明亮的蓝色荧光,表现为明显的凋亡病理现象,细胞凋亡率、细胞BAX/BCL-2比值与E-cadherin蛋白表达显著升高(P<0.05),细胞迁移率与侵袭数、细胞蛋白(N-cadherin,Vimentin,Wnt1,β-catenin)表达显著降低(P<0.05);与木犀草素组比较,木犀草素+氯化锂组细胞核的凋亡病理现象明显减轻,细胞凋亡率、细胞BAX/BCL-2比值与E-cadherin蛋白表达显著降低(P<0.05),细胞迁移率与侵袭数、细胞蛋白(N-cadherin,Vimentin,Wnt1,β-catenin)表达显著升高(P<0.05).说明木犀草素可通过抑制Wnt/β-catenin信号途径传导而降低MuM-2C活力,促进其凋亡,并抑制其迁移和侵袭.

微RNA-132-3p靶向第10号染色体缺失的磷酸酶和张力蛋白同源物调控葡萄膜黑色素瘤细胞增殖与凋亡

目的 研究微RNA(miR)-132-3p在葡萄膜黑色素瘤细胞增殖、凋亡中的作用及其作用机制。方法 该研究起止时间为2018年2月至2019年7月。定量聚合酶链反应(qPCR)检测正常葡萄膜上皮细胞ARPE-19和葡萄膜黑色素瘤细胞SP6.5、M23中miR-132-3p表达。SP6.5细胞中转染miR-132-3p干扰质粒(anti-miR-132-3p)、第10号染色体上缺失的磷酸酶和张力蛋白同源物(PTEN)过表达质粒(pcDNA3.1-PTEN)或共转染anti-miR-132-3p和PTEN干扰质粒(si-PTEN),MTT法和流式细胞术分别检测细胞增殖与凋亡,蛋白质印迹法检测PTEN、细胞周期蛋白D1(cyclin D1)、周期素依赖激酶抑制剂p21(P21)、B细胞淋巴瘤-2(Bcl-2)和Bcl-2相关X蛋白(Bax)蛋白表达,生物信息学预测结合双萤光素酶报告实验分析miR-132-3p与PTEN的靶向关系。结果 与ARPE-19细胞相比,SP6.5、M23细胞中miR-132-3p表达量(0.26±0.02比0.94±0.09、0.81±0.08)明显升高(P<0.05)。与anti-miR-132-3p阴性对照(anti-miR-NC)组相比,anti-miR-132-3p组24 h、48 h、72 h的细胞活性(0.51±0.05比0.30±0.03、0.97±0.09比0.45±0.05、1.40±0.14比0.76±0.07)、cyclin D1、Bcl-2蛋白表达量显著降低(P<0.05),细胞凋亡率[(8.03±0.68)%比(21.51±2.06)%]、P21、Bax水平明显提高(P<0.05),与过表达PTEN相同。miR-132-3p与PTEN之间有靶向调控关系。抑制PTEN能逆转抑制miR-132-3p对SP6.5细胞增殖的抑制作用及对细胞凋亡的促进作用。结论 miR-132-3p通过直接靶向PTEN调控葡萄膜黑色素瘤细胞增殖与凋亡。

黑色素瘤缺失因子2通过调控MMP9表达影响滋养细胞的迁移能力

目的:探讨黑色素瘤缺失因子2(AIM2)通过调控基质金属蛋白酶的表达水平,从而影响滋养细胞的迁移参与反复自然流产可能的发生机制。方法:采用Real-Time PCR和Western blot技术检测21例反复自然流产患者胎盘组织中AIM2的表达水平,同时以30例正常胎盘组织为对照组。采用激动剂poly(dA:dT)刺激滋养细胞系HTR-8/SVneo,通过Real-Time PCR和Western Blot检测滋养细胞中AIM2、基质金属蛋白酶2(MMP2)和基质金属蛋白酶9(MMP9)基因和蛋白的表达情况。随后,利用小干扰RNA技术基因沉默AIM2,Western blot、明胶酶谱和细胞划痕实验进一步研究抑制AIM2对MMP9表达和滋养细胞迁移能力的影响。结果:反复自然流产患者胎盘组织中AIM2的表达水平显著低于正常对照组(P<0.001),poly(dA:dT)可显著激活HTR-8/SVneo细胞中AIM2、MMP9 mRNA和蛋白上调表达,而基因沉默AIM2后,滋养细胞MMP9的表达水平、明胶水解能力以及细胞迁移能力均显著降低(P<0.001)。结论:滋养细胞中AIM2的下调表达可引起MMP9表达水平降低,从而导致滋养细胞迁移能力下降,与反复自然流产发生具有较高的相关性。

裸鼠皮下人恶性黑色素瘤在纳秒脉冲电场下的凋亡机制

为研究ns脉冲电场(nsPEF)治疗在体肿瘤的生物电效应机制,以接种人黑色素瘤细胞A375的BALB/c裸鼠为研究对象,采用电压幅值为4kV、脉冲宽度为200ns、重复频率为1Hz的脉冲电场进行处理。用凝胶电泳法检测脉冲处理后的DNA Ladder分布情况表明,与对照组相比,处理组有明显阶梯状分布,即细胞发生凋亡。用TUNEL法检测肿瘤组织的凋亡情况表明,处理组表现出较高凋亡率(检验水准P<0.01)。用Western blot法和免疫组织化学方法检测脉冲处理后肿瘤组织中促凋亡蛋白Bax、凋亡抑制蛋白Bcl-2的表达量情况,2者共同表明,与对照组相比,处理组Bax表达量显著升高(P<0.01),而Bcl-2表达量明显降低(P<0.01)。实验结果揭示nsPEF通过Bax、Bcl-2基因调控作用来诱导肿瘤凋亡。

纳秒脉冲电场治疗裸鼠皮下人恶性黑色素瘤模型的长期效应

为研究ns脉冲电场(nsPEF)对在体肿瘤的长期杀伤效应,以接种人恶性黑色素瘤A375细胞的BALB/c裸鼠为研究对象,采用电压幅值为4kV、脉冲宽度为200ns、重复频率为1Hz的ns脉冲电场进行治疗。肉眼观察结果表明,瘤体随时间推移而逐渐消褪直至消失,且皮肤恢复完好,原位瘤在平均2周时间内完全消失;瘤体生长抑制情况检测结果表明,与对照组相比,治疗组裸鼠肿瘤体积明显缩小(检验水准P<0.05),随着生存时间延长,对照组和治疗组肿瘤生长速度差别增大;荷瘤裸鼠的存活率-时间关系研究结果表明,ns脉冲电场治疗后26d时间内,对照组裸鼠全部死亡,而治疗组裸鼠存活率高达100%。实验结果表明ns脉冲电场能有效抑制肿瘤组织的生长,并可大大提高荷瘤BALB/c裸鼠的长期存活率。