Establishment of a Human Malignant T Lymphoma Cell Line Carrying a Retrovirus-like Particles with RT Activity

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a femalc patient with nervous systcm disease, the binlogical characteristics of CM-1 cells was studied in this paper. Another T lymphocytes,such as peripheral T lymphocytes donated by a maIe patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line u'as estabIished. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrenceof typical maIignant lymphoma. The observation of eIectron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar toretrovirus in the ultra-structure characteristics. lt was found that this virus possesses reverse transcriptase activity. ResuIts obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly usedin our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retro virus. Meanwhile, the work on the clone and sequence analysis ofthis virus are being carried out.

Water Soluble Propolis and Royal Jelly Enhance the Antimicrobial Activity of Honeys and Promote the Growth of Human Macrophage Cell Line

Due to the overuse and misuse of antibiotic, an increase in antibiotic resistance of pathogenic bacteria is evolving. Attention should be focused on natural alternatives to antibiotics, like propolis, royal jelly （R J） and honeys. They all have strong antibacterial properties due to the active substances they contain. This study investigated the effect of combination of water soluble propolis （WSP） Greitl20 or fresh royal jelly （F-RJ） （MiZigoj） and Forest honeys as antibacterial against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii, Staphylococcus aureus, methicillin resistant Staphylococcus aureus （MRSA）, Streptococcus pyogenes, Streptococcus agalactiae and Candida albicans. These substances are also cell growth promoters for human macrophage （TLT） cell line. WSP Greitl20, F-RJ （M） and different Forest honeys were prepared in saline as 10% solutions. The antimicrobial activity was expressed as the minimal inhibitory concentration （MIC） in mg/mL. The growth promotion activity was measured at optical density （OD） 595 nm. The combination ofWSP Greitl20 with different Forest honeys is better than F-RJ （M） in same combination with different Forest honeys. The best antibacterial/antifungal activity was found with the combination of 10% WSP Greit 120 in the Forest honey （1：10） from Italy or Spain. When measuring the growth promoting activity of TLT cell line, the best activity was detected at the combination of 10% WSP Greitl20 in the Forest honey from Italy （GI3 = 0.796 ± 0.014 and GI5 = 1.133± 0.022）. Antimicrobial and growth promoting activities are correlated and WSP-dependent.

CONDITIONED MEDIUM OF HUMAN NASOPHARYNGEAL CARCINOMA EPITHELIOID CELL LINE CNE_(1) CONTAINED THE ACTIVITIES OF TRANSFORMED GROWTH-INHIBITING FACTORS

The hormone defined serum free conditioned medium (SFCM) of human nasopharyngeal carcinoma epithelioid cell line (CNE1) was assayed by both the 3H-thymidine incorporation test and the soft agar test. It was found that the SFCM stimulated the growth of long-term serum-free cultured CNE4 cells in ac-cordence with the fact that the growth rate of long-term serum-free cultured CNE1 cells was directly proportional to the plating density. Alternatively 5% SFCM inhibited the growth of short-term serum-free cultured CNE4 cells by 51% in which the indicator cell remained the responsiveness state of growing in the serum-supplemented medium to the effector of interest. Furthermore, SFCM resulted in the inhibition of anchorage-independent growth of CNE4 cells and A431 cells. Also in soft agar test. SFCM reduced the colony formation of NRK(?),9F cells in the presence of EGF or EGF plus TGF-β. These finding suggested that CNE4 secreted autocrine growth stimulating factor(s) and growth inhibiting factor(s) in the serum-free medium, the latter strongly reverse malignant phenotypes of CNE4 and A431 cells in serum-supplemented surrounding.

Fermented Herbal Decoction Selectively Targeting Human Cancer Cell Line and Human Pathogenic Microorganism

Introduction: Prolonged immuno-suppressed status promised to induce internal growth of malignant cell and infectious agent, yet, only a small part of affected individuals seek medical attention or berried by commercially over-flowed fake information. Several studies have described complementary and alternative medicine as effective strategies for improving anti-infectious agent including malignant cell. The purpose of this study was to investigate the effect of a fermented herbal decoction (FHD) both in vitro and in vivo to malignant cells and microorganism by regulating leukocyte subset proportioning FHD as dietary material. Methods: In this approach of alternative study, selective anti-cancer effect by fermented decoction was tried to show first in vitro system both, cancer cell and virus strain. The fermented herbal decoction consisting of 80 sorts of herbs and fruits. The selective toxicity was set up and then for immunological factors in animal and human. The most important factor is to reduce side effect for a normal cell. Results: First, FHD was proved as safe by animal test. FHD regulated also the proportion of granulocyte and lymphocyte ratio both animal and human. In vitro culture showed selective toxicity by FHD against human melanoma and leukemia cell line but reduced toxicity was showed by normal cell line. As for the anti-virus activity, anti-virus effect was tested on the feeder layer of human fibroblast cell, after 9 days of culture. Second, FHD inhibits colon cancer growth in 3-methylholanthrene induced cancer in rat. Conclusion: The present results suggest that our fermented herbal decoction showed selective anti-cancer activities and anti-virus activities, together with the regulative effect on the immune system.

Studies on mechanism of cis9,trans11-CLA and trans10,cis12-CLA inducing apoptosis of human breast cancer cell line MCF-7

Objective： The aim of the study was to explore the activities of cis9, trans11-CLA （C9, t11-CLA） and transl0, cis12-CLA （t10, c12-CLA） inhibiting tumor, and investigate their relationships with PPARy and apoptotic proteins, and mechanism of anti-cancer. Methods： The inhibitory rate, cell growth curve and apoptotic morphological observation of MCF-7 cells were obtained by MTT assay, trypan blue staining and Hoechst33342 fluorescence staining. The apoptotic rate and cell cycle were detected with flow cytometry. Transcriptional level of genes was detected with RT-PCR semi-quantitative method, and Western blot was performed to detect proteins levels. Results： The two CLA isomers could reduce cell proliferation （P 〈 0.05）, increase apoptotic rate （P 〈 0.05）, and increase obviously the transcriptional and protein levels of PPARy （P 〈 0.01）. The synchronism and correlation between the effects of CLA to PPARy and apoptotic proteins Bax, Bcl-2, Caspase 3 changes were found with the dose- and time-dependent manners. There was cooperative relation between the levels of PPARy and the rates of Bax/Bcl-2, Caspase 3 （small fragment） by experiments of PPARy inhibitor GW9662 and ligand Rosiglitazone. Conclusion： The apoptotic pathway of PPARy-Bcl-2-Caspase 3 signaling was found. The C9, t11-CLA and tl0, c12-CLA could inhibit MCF-7 cell proliferation and promote apoptosis via activating PPARy-Bcl-2-Caspase 3 pathway. CLA may be a kind of activator of PPARv.

Inhibitory Effects of Mild Hyperthermia plus Docetaxel Therapy on ER(+/–) Breast Cancer Cells and Action Mechanisms

Summary： The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment approach. The effects of docetaxel on the proliferation of cells from the estrogen receptor （ER）-positive human breast cancer cell line MCF-7 and the ER-negative human breast cancer cell line MDA-MB-453 were examined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and effective experimental concentrations of docetaxel were determined. The effects of mild hy- perthermia plus docetaxel therapy on apoptosis rate in the MCF-7 and MDA-MB-453 human breast cancer cell lines were analyzed by using flow cytometry with Annexin-V fluorescein isothiocyanate （FITC）/propidium iodide （PI） staining. The effects of these combined treatments on cell cycle progres- sion in the MCF-7 and MDA-MB-453 human breast cancer cell lines were examined by using flow cy- tometry. The effects of these combined treatments on the expression of apoptosis-related proteins and proteins in the mitogen-activated protein kinase （MAPK） pathways were analyzed by using Western blotting. The effects of these combined treatments on the expression of the heat shock protein 70 （HSP70） and the multi-drug resistance （MDR） gene product P-glycoprotein （Pgp） were examined by using Western blotting. The results showed that the half-maximal inhibitory concentration （IC50） of do- cetaxel for MCF-7 and MDA-MB-453 cells was 19.57±1.12 and 21.64±2.31 gmol/L respectively. Mild hyperthermia with docetaxel therapy could increase apoptosis rate in the MCF-7 and MDA-MB-453 cells. Apoptosis rate in MCF-7 and MDA-MB-453 cells was increased from （23.66±3.59）% and （18.51±3.17）% in docetaxel treatment group to （47.12±6.73）% and （55.16±7.42）% in mild hyperthermia plus docetaxel group, indicating that the mild hyperthermia and docetaxel therapeutic approaches exhib- ited significant synergistic antitumor effects. Treatments of mild hyperthermia plus docetaxel induced G2/M cell cycle arrest in the MCF-7 and MDA-MB-453 cells. Western blotting demonstrated that pro- teins in the MAPK pathway were expressed at higher levels in docetaxel-treated cells following mild hypothermia than those in cells treated with docetaxel alone. As compared with blank control group, cells from the mild hyperthermia plus docetaxel group exhibited significantly decreased B-cell lym- phoma 2 （Bcl-2） protein expression but slightly increased Bcl-2-associated X protein （Bax） expression. Western blotting results revealed that HSP70 and Pgp expression levels were significantly increased following mild hypothermia. It was concluded that treatments of mild hyperthermia plus docetaxel in- hibited the proliferation of human breast cancer cells, promoted apoptosis of breast cancer cells, and produced synergistic antitumor effects.

医用重组人源胶原蛋白功能敷料体外免疫原性评价

目的对一种医用重组人源胶原蛋白功能敷料的体外免疫原性进行评价。方法以细胞培养液为浸提介质,按0.2 g/ml的比例浸提制备试验液,进行体外淋巴细胞增殖试验、人细胞系激活试验(h-CLAT)、细胞炎症因子含量检测。结果体外淋巴细胞增殖试验中,100%,50%,25%3种浓度试验液的淋巴细胞增殖率分别为105%,111%,86.3%,与阴性对照组比较,差异无统计学意义(P>0.05)。h-CLAT结果显示,试验组THP-1细胞表面分子CD54 RFI值<200,CD86 RFI值<150,判定为阴性结果。试验组细胞上清中肿瘤坏死因子α(TNF-α)、白介素8(IL-8)的含量与阴性对照组比较,差异无统计学意义(P>0.05)。结论医用重组人源胶原蛋白功能敷料有良好的生物相容性。

Anti-senescence effect and molecular mechanism of the major royal jelly proteins on human embryonic lung fibroblast(HFL-I) cell line

Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs have anti-senescence activity for human cells remains.Human embryonic lung fibroblast (HFL-I)cells were cultured in media containing no MRJPs (A),MRJPs at 0.1mg/ml (B),0.2mg/ml (C),or 0.3mg/ml (D),or bovine serum albumin (BSA)at 0.2mg/ml (E).The mean population doubling levels of cells in media B,C,D,and E were increased by 12.4%,31.2%,24.0%,and 10.4%,respectively,compared with that in medium A.The cells in medium C also exhibited the highest relative proliferation activity,the lowest senescence,and the longest telomeres.Moreover, MRJPs up-regulated the expression of superoxide dismutase-1(SOD1)and down-regulated the expression of mammalian target of rapamycin (MTOR),catenin beta like-1(CTNNB1),and tumor protein p53(TP53).Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials,amide carbonyl group vibrations and aromatic hydrogens.These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line,and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.

几种壳聚糖类产品的致敏试验研究

目的通过豚鼠最大剂量试验(GPMT)、小鼠局部淋巴结试验(LLNA)、人细胞系激发试验(h-CLAT)探究几种壳聚糖类产品的致敏性。方法将羧甲基壳聚糖、壳聚糖止血粉、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱作为试验样品,按GB/T 16886.12规定的比例浸提制备受试液,按GB/T 16886.10-2017进行GPMT、LLNA试验,按OECD442(E)进行h-CLAT试验,对样品进行致敏性检测。结果羧甲基壳聚糖、壳聚糖止血粉、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱的GPMT、LLNA试验结果均为阴性。h-CLAT试验中,羧甲基壳聚糖、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱的综合判定结果为阴性;壳聚糖止血粉100%、50%、25%浓度受试液CD54的相对荧光强度(RFI)均高于2.00,CD86的RFI均高于1.50,综合判定结果为阳性。结论采用作为皮肤致敏评价体外替代方法之一的h-CLAT评估壳聚糖止血粉的致敏反应风险有待于进一步研究。

土木香中纯化的五种倍半萜类化合物抑制肿瘤增殖活性的研究

目的检测土木香中纯化的五种倍半萜化合物抑制肿瘤增殖的活性,并探讨化合物结构与活性之间的关系。方法应用MTT法测定五种倍半萜类化合物对体外培养人肿瘤细胞增殖的影响;应用小鼠移植性肝癌模型测定了异土木香内酯的抗肿瘤活性。结果化合物1(异土木香内酯)对U251SP细胞、HLE细胞和MM1-CB细胞的增殖显示较强的抑制活性;化合物2～5对各种实验用肿瘤细胞的增殖不显示抑制活性;化合物1对移植性肿瘤(肝癌H22)具有明显的抑制作用,并呈现较好的剂量依赖关系。结论异土木香内酯具有较强的肿瘤抑制活性;化合物2～5对肿瘤细胞增殖抑制活性丧失可能由于A-环和B-环之间的键裂开,形成一个大10元环,改变了原来的构象所致。

三种倍半萜类化合物体外抗肿瘤细胞增殖活性研究

利用四唑盐(MTT)比色法检测观察菊科植物中分离出的三种倍半萜类化合物,异土木香内酯(1),1氧--乙酰大花旋覆花内酯(2)和大花旋覆花内酯(3)对人脑神经胶质瘤细胞、肝癌细胞、人黑色素瘤和人乳腺癌脑转移肿瘤细胞生长的影响,探讨这三种倍半萜类化合物的体外抗肿瘤细胞增殖作用以及化合物结构与活性之间的构效关系。结果发现异土木香内酯对人脑神经胶质瘤细胞、人肝癌细胞、人和色素瘤细胞和人乳腺癌脑转移肿瘤细胞的增殖均有明显的抑制作用,1氧--乙酰大花旋覆花内酯和大花旋覆花内酯即使在100μmol/L的高浓度下,对四种肿瘤细胞的增殖不显示抑制活性,推测A环-开环可能是导致桉叶烷型倍半萜内酯的体外抗肿瘤细胞增殖作用消失或减弱的原因。

补肾、健脾、益气、活血法对衰老细胞周期基因表达的调控作用

目的:比较补肾、健脾、益气、活血法对衰老细胞周期基因表达的调控作用。方法:采用上述4种不同的含药血清对衰老的人胚肺二倍体成纤维细胞2BS细胞株进行处理,通过细胞寿命实验、流式细胞仪、RT-PCR、Western blot方法研究不同中药对衰老细胞周期及其相关基因(P16^(INK4)、Cyclin D1及PCNA)的mRNA转录和蛋白表达的影响。结果:补肾、益气中药对衰老细胞周期有一定的促进作用,并可下调衰老细胞增殖抑制基因P16和周期蛋白Cyclin D1的mRNA/蛋白表达;上调细胞周期促进增殖基因PCNAmRNA/蛋白的表达。而健脾、活血中药对细胞周期及其相关基因和蛋白表达的作用不明显。结论:补肾、益气方药对细胞周期有促进作用,其中的作用可能是通过促进P16途径的基因表达来实现。

新城疫病毒7793株对人结肠癌细胞的杀伤作用

目的:研究新城疫病毒NDV7793对人结肠癌细胞的体外杀伤作用,为结肠癌的生物疗法奠定基础。方法:通过蚀斑实验纯化病毒并测定纯化的NDV7793株的感染力;用乳酸脱氢酶微量释放法测定纯化病毒对人LoVo和Ls174t结肠癌细胞株的杀伤作用并且通过血凝实验测定病毒在不同细胞中的增殖力。结果:NDV7793在感染细胞96h后出现直径约为0.5mm左右的空斑,PFU为1.25×107个/ml,为弱毒株;NDV7793对LoVo和Ls174t人结肠癌细胞株有明显的杀伤作用,而且杀伤作用的强度与病毒作用的时间和病毒的浓度呈正相关的关系;NDV7793可以在肠癌细胞中生长复制,该病毒株在人结肠癌细胞株LoVo的复制能力强于Ls174t。结论:NDV7793具有较强的选择性杀伤人结肠癌细胞的作用,且为弱毒株,这株病毒具备肿瘤生物治疗的潜能。

钙通道活性与胃泌素促人结肠癌细胞增殖间关系的研究

目的 探讨钙通道活性在胃泌素促人结肠癌细胞增殖中的作用。方法 运用流式细胞仪检测细胞内游离钙离子水平 ,MTT比色法测定细胞增殖情况。结果 2 5× 10 -6M的五肽胃泌素 (PG)可以引起HT2 9细胞内游离钙离子水平明显升高 (P <0 0 1) ,钙通道阻滞剂nifedipine(10 -5M)可以使PG引起的钙离子水平升高幅度明显下降 (P <0 0 1)。同时可以部分抑制PG促增殖作用 (P <0 0 5 )。钙通道激动剂Bayk86 4 4 (10 -6M)可以明显升高细胞内钙离子水平 (P <0 0 1)。并能促进HT2 9细胞增殖 (P <0 0 5 ) ,与PG的促增殖作用相比无显著性差异 (P >0 0 5 )。结论 钙通道作为调节细胞内钙离子变化的主要途径 ,在调控PG促HT2

土木香根中5种倍半萜化合物抗肝癌活性的研究

目的:检测菊科植物土木香中分离出的5种倍半萜类化合物对肝肿瘤活性的影响,探讨这5种倍半萜类化合物结构与活性之间的关系以及可能的作用机制。方法:利用噻唑蓝(MTT)比色法检测5种倍半萜类化合物对人肝肿瘤细胞增殖活性的影响;以移植性小鼠肝肿瘤H22为模型,检测异土木香内酯对昆明小鼠在体肿瘤生长以及机体免疫能力的影响;以体外培养的人胚肺成纤维细胞为模型,评价异土木香内酯对正常细胞的毒性。结果:异土木香内酯对人肝肿瘤细胞(HLE)的增殖显示较强的抑制活性;其余4种化合物对HLE的增殖不显示抑制活性;异土木香内酯对小鼠移植性肝肿瘤H22体内生长具有较强的抑制活性,但对荷瘤小鼠胸腺指数和脾指数的影响与对照组相比差异均无统计学意义(P>0.05);异土木香内酯对体外培养的人胚肺成纤维细胞显示较弱的毒性。结论:异土木香内酯具有较强的抗肝癌活性;其它4种倍半萜类化合物抑制活性的丧失可能是由于化合物中五元内酯环的环外双键饱和所致,或A、B环的C5-C10键断开生成十元大环所致;增加机体免疫能力可能是异土木香内酯抗肝肿瘤的作用机制之一。

直接多肽结合试验组合人细胞系活化试验预测皮肤致敏物的探讨

目的建立直接多肽结合试验(DPRA)和人细胞系活化试验(h-CLAT)的皮肤致敏组合检测方法,对化学品及植物提取物的致敏性进行初筛。方法选择12种化学品和7种植物提取物为受试物,把不同受试物分别与两种肽(半胱氨酸肽和赖氨酸肽)共孵育24 h,采用高效液相色谱法分析反应后多肽消耗。同时将不同浓度的受试物与体外培养的人急性单核细胞白血病细胞(THP-1)共孵育24 h,通过流式细胞仪检测暴露后细胞表面标志物CD86和CD54的变化。再进一步比较DPRA和h-CLAT预测结果的一致性。结果 DPRA方法和h-CLAT方法准确区分了12种化学品的皮肤致敏性,其中2种判定为阴性,10种判定为阳性,两种方法检测结果一致。DPRA对植物提取物致敏性的预测中,除绿茶提取物无法判定外,其余6种均为皮肤致敏疑似物质。h-CLAT预测中,除绿茶提取物、马齿笕提取物和人参果提取物为非致敏物,其余4种植物提取物为致敏物。DPRA与h-CLAT预测的一致性为0.57。结论 DPRA与h-CLAT的简单组合可以实现对单一化合物的准确预测,对于复杂混合物可实现初步预测,确认需要进一步组合其他方法。

α粒子诱发BEP2D细胞恶性转化中细胞内抗氧化蛋白和活性氧水平研究

目的:研究α粒子诱发永生化人支气管上皮细胞BEP2D恶性转化过程中细胞内主要抗氧化蛋白的表达和活性氧(ROS)水平以及DNA双链断裂水平的变化。方法:选择BEP2D细胞、RH22细胞和BERP35T-1细胞,采用Western blot检测细胞内抗氧化蛋白过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPXs)以及铜锌超氧化物歧化酶(Cu/Zn-SOD)和锰-SOD(Mn-SOD)的表达;采用SOD测定试剂盒检测细胞内总SOD(T-SOD)、Cu/Zn-SOD和Mn-SOD酶活力;荧光探针标记结合流式细胞仪检测细胞内基础H_2O_2和O_2^(?)水平;中性彗星电泳法检测细胞内DNA双链断裂水平。结果:与BEP2D细胞相比,RH22和BERP35T-1细胞内抗氧化蛋白CAT和GPX1表达下调(P<0.05或P<0.01),GPX3、Cu/Zn-SOD和Mn-SOD表达增强(P<0.05或P<0.01);且T-SOD、Cu/Zn-SOD和Mn-SOD活力均显著升高(P<0.05或P<0.01)。RH22和BERP35T-1细胞内基础O_2^(?)水平低于BEP2D细胞,基础H_2O_2和DNA双链断裂水平则高于BEP2D细胞(P<0.05)。结论:细胞内氧化/抗氧化失衡形成氧化压力,促进DNA氧化损伤和基因组不稳定性,可能是α粒子诱发BEP2D细胞恶性转化的机制之一。

丙型肝炎病毒NS5B在Hep3B细胞的表达及活性分析

目的丙型肝炎病毒NS5B基因转染人肝癌细胞系Hep3B细胞,检测NS5B的表达与细胞内RNA聚合酶活性。方法使用脂质体把包含全长丙型肝炎病毒NS5B基因的重组载体pcDNA-5B转染到Hep3B细胞。RT-PCR和Wes-tern blot鉴定NS5B基因的表达,荧光素酶检测NS5B的细胞内RNA依赖的RNA聚合酶活性。结果RT-PCR和Westernblot发现转染NS5B基因的Hep3B细胞产生NS5B mRNA和NS5B蛋白,荧光素酶分析表明Hep3B细胞表达的NS5B蛋白具有细胞内RNA依赖的RNA聚合酶活性。结论人肝癌细胞系Hep3B细胞可以成功表达NS5B基因,且表达的NS5B蛋白具备细胞内RNA依赖的RNA聚合酶活性。

二甲双胍对人肝癌细胞 HepG2增殖及脂肪酸合酶的影响

目的二甲双胍治疗的糖尿病患者癌症发生风险较其他药物治疗者显著降低。探讨二甲双胍在人肝癌细胞HepG2中的抗肿瘤活性与脂肪酸合酶的关系。方法选取不同浓度(1、5、10、15 mmol/L)二甲双胍处理HepG2细胞24、48、72 h,用CCK-8法检测其对细胞增殖的影响。同时设阳性对照(紫杉醇10μg/m L),阴性对照(二甲双胍0 mmol/L)。设0、5、10、15 mmol/L二甲双胍处理72 h,用Western blot检测腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)、磷酸化AMPK(P-AMPK)、脂肪酸合酶(fatty acid synthase,FASN)、磷酸化哺乳动物雷帕霉素靶蛋白(P-m TOR)、磷酸化蛋白激酶B(P-Akt)蛋白表达,RT-PCR检测FASN mRNA的表达水平。结果 1、5、10、15 mmol/L二甲双胍干预24、48、72 h,分别随二甲双胍浓度与处理时间的增加,HepG2细胞的增殖抑制作用逐渐增强(P<0.05),且呈时间和浓度依赖性。其中10 mmol/L二甲双胍处理后增殖抑制率在72 h接近50%、15 mmol/L二甲双胍处理后增殖抑制率均>50%。0、5、10、15 mmol/L二甲双胍处理HepG2细胞72 h后,P-AMPK的蛋白表达随药物浓度增高而上调,P-m TOR、FASN的蛋白表达随药物浓度增高而下调,三者在10、15 mmol/L二甲双胍作用后的表达较阴性对照的差异均有统计学意义(P<0.05);而P-Akt蛋白表达在二甲双胍各浓度间差异无统计学意义(P>0.05)。FASN mRNA的表达随药物浓度增加呈下降趋势,5、10、15 mmol/L二甲双胍作用后表达量均较阴性对照显著下降(P<0.05)。结论二甲双胍的的抗肿瘤作用与其激活AMPK、抑制m TOR和FASN有关。二甲双胍虽然抑制了m TOR的活化,但没有造成Akt的反馈性激活。

信号转导子与转录活化子6(STAT6)在人结肠癌细胞株HT29(STAT6^(high))、Caco2(STAT6^(null))细胞凋亡中的作用

目的通过分析信号转导子与转录活化子6(signal transducer and activator of transcription 6,STAT6)活化状态时不同的人结肠癌细胞株HT29(STAT6high)和Caco2(STAT6null)凋亡情况来研究STAT6与细胞凋亡之间的关系,并从分子水平探讨其可能的机制。方法采用流式细胞仪检测人结肠癌细胞株HT29(STAT6high)和Caco2(STAT6null)细胞凋亡的情况,比较其差异;同时采用RT-PCR检测人结肠癌细胞株HT29(STAT6high)和Caco2(STAT6null)中凋亡相关基因(Caspase家族蛋白Caspase3 mRNA、Caspase7 mRNA和Bcl-2家族蛋白凋亡抑制蛋白Bcl-2 mRNA、Bcl-xl mRNA、促凋亡蛋白Hrk mRNA)的表达水平,比较其差异。结果人结肠癌细胞株Caco2(STAT6null)细胞早期凋亡率为(13.30±0.73)%,明显高于HT29(STAT6high)的(2.00±0.43)%(P<0.01)。RT-PCR显示,人结肠癌细胞株Caco2(STAT6null)中Caspase3 mRNA和Caspase7 mRNA表达水平均明显高于HT29(STAT6high)(均P<0.01)。人结肠癌细胞株Caco2(STAT6null)中凋亡抑制蛋白Bcl-2 mRNA、Bcl-xl mR-NA、促凋亡蛋白Hrk mRNA表达水平均明显高于HT29(STAT6high)(均P<0.01)。人结肠癌细胞株Caco2(STAT6null)、HT29(STAT6high)中STAT6活性水平与Caspase7、Caspase3、Bcl-2、Bcl-xl、Hrk mRNA表达水平均呈负相关(r=-0.514、-0.562、-0.518、-0.512、-0.426,均P<0.05)。结论 STAT6可能参与结肠癌细胞凋亡,其机制可能与凋亡相关基因的表达有关。