Captopril modulates hormone receptor concentration and inhibits proliferation of human mammary ductal carcinoma cells in culture

The present study evaluated the effect of the angiotensin converting enzyme (ACE) inhibitor captopril on estrogen (ER) and progesterone (PR) receptor concentration and on proliferation in two lines of human mammary ductal carcinoma cells in culture: T-47D (ER+/PR+) and Hs578T (ER–/PR–). The incorporation of [³H]thymidine, validated by cell count, served as an index of proliferation. Compared to control cells, T-47D cells incubated for 48 hrs in 1, 2, or 5 mM captopril (but not in 0.5 mM) exhibited a reduction in ER from 130 ± 6 to 32 ± 32 fmol/mg cytosolic protein, and an increase in PR from 1780 ± 120 to 2740 ± 400 fmol/mg protein (p < 0.05). Western analysis confirmed these drug-induced changes in the concentration of immunoreactive receptor proteins. Captopril also induced the appearance of low but detectable PR in the Hs578T cells at concentrations as low as 50 µM. Captopril inhibited the incorporation of [³H]thymidine by both cell types during a 48 hr incubation, although Hs578T cells were 2–3 times more resistant than were T–47D cells. This cytostatic effect of captopril was not due to cytotoxicity as indicated by ⁵¹Cr release, and was not accompanied by significant changes in cell cycle distribution as determined by flow cytometry. The incorporation of [³H]uridine (RNA synthesis) and [¹⁴C]alanine (protein synthesis) also were inhibited by captopril, suggesting a general antimetabolic effect of the drug in the ductal carcinoma cells. These are novel actions of a common antihypertensive agent. In contrast, the nonthiol ACE inhibitor lisinopril, and penicillamine, a thiol compound with virtually no ACE inhibitory activity, had no effect on any of these endpoints.     

ITAC转染乳腺癌细胞系4T1的体内外生物学行为研究

目的:观察转染ITAC对乳腺癌细胞系4T1体内及体外生物学行为的影响。方法:构建pcDNA3-ITAC真核表达质粒,基因转染的方法建立稳定表达ITAC的乳腺癌细胞系ITAC-4T1。体外及体内观察ITAC-4T1细胞的生长情况。RT-PCR检测肿瘤组织ITACmRNA转录水平。杀伤实验检测脾细胞杀伤活性,FACS检测CD8 T细胞IFN-γ的分泌。结果:体外ITAC-4T1细胞的生长与未转染及转染空载体的4T1细胞没有差别(P>0.05)。体内ITAC-4T1细胞形成的肿瘤生长较对照组明显减慢(P<0.05)。ITAC-4T1肿瘤组织检测到较高水平的ITACmRNA转录(P<0.01)。接种ITAC-4T1细胞的小鼠脾细胞杀伤率显著高于对照组(P<0.05),CD8 T细胞IFN-γ分泌明显增加(P<0.05)。结论:ITAC基因转染可以抑制4T1细胞体内生长,与ITAC诱导Th1型细胞免疫应答,增强效应细胞特异性杀伤活性相关。     

Histone acetylation decreased by estradiol in the MCF-7 human mammary cancer cell line

Summary The effect of estradiol (E₂) on the [³H]-acetylation of nuclear histones was studied in the MCF-7 human mammary cancer cell line in culture. Cells (~ 10⁸) were incubated with 8 × 10^–6M [³H]-acetate in the absence (control) or in the presence of estradiol (10^–5–10^–8M). After 20 min incubation, the nuclear histones were extracted and separated by electrophoresis, and each histone band was measured and calculated in DPM/mg protein. It was observed that only the H₂ + H₃ and H₄ histones were associated with the [³H]-acetate. Estradiol (10^–6–10^–8M) provoked a significant inhibition in the incorporation of the acetate. The negative effect, in percentage of the non-treated cell value, was as follows: in E₂ (10^–6M): – 25 ± 10 (SE) for H₂ + H₃ and – 26 ± 5 for H₄; in E₂ (10^–7M): – 35 ± 9 and – 39 ± 10; and in E₂ (10^–8M): – 56 ± 22 and – 30 ± 13 respectively. It is concluded that estradiol has a negative effect in the acetylation of H₂, H₃ and H₄ histones of this mammary cancer cell; no acetylation or effect is observed in H₁ histones. The relationship of this finding to the biological responses of the hormone is to be explored.     

Cytoprotective activity of a trans-chalcone against hydrogen peroxide induced toxicity in hepatocellular carcinoma (HepG2) cells

Dietary flavonoids have attracted attention as chemopreventive agents. Chalcones are abundantly present in nature starting from ferns to higher plants. Chemically 1,3-diphenyl-2-propen-1-ones, these are often cytotoxic in vitro. The cellular defense system (including glutathione, glutathione-related enzymes, and antioxidant and redox enzymes) plays a crucial role in cell survival and growth in aerobic organisms. In the present study, we aimed to evaluate the modulatory effect of trans-chalcone on protection from oxidative stress caused by hydrogen peroxide (H2O2) in hepatocellular carcinoma (HepG2) cells. Cell growth was evaluated by the 3-(4,5-dimethyl thiazol-2- yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Sub-toxic concentrations of compound (20 uM) increased cell survival and a decreased lipid peroxidation. The drug also decreased the H2O2 induction of glutathione related enzymes. Our results support the efficacy of trans-chalcone in offering protection against oxidative stress.     

Antibodies to a surface membrane marker from human mammary carcinoma cell line

A tumor surface antigen (BTA-BT20-68K) was isolated from a human mammary carcinoma cell line (BT-20). The antigen (Mr 68,000) induced the formation of high titer antibodies which recognized BTA-BT20-68K as a cell surface marker by the immune adherence hemagglutination test and recognized the soluble antigen by solid phase radioimmunoassay. The antibodies which failed to recognize human beta-2-microglobulin, alpha-fetoprotein, and carcinoembryonic antigen were cytotoxic to the parent BT-20 tumor cells at high serum dilutions. The antibodies recognized a similar tumor surface marker isolated directly from human breast adenocarcinomas, but failed to recognize human lymphocyte antigens isolated from BT-20 cells or bound to human lymphocytes bearing human lymphocyte antigen markers in common with those of BT-20 cells. Added to BT-20 tumor cells in culture and in the absence of complement, antibody-dose-related inhibition of tumor cell growth was documented. In the presence of complement, the antibodies were highly cytotoxic to the parent cells. These results demonstrate the presence of a unique tumor surface marker with chemical and immunological properties in common with that isolated directly from human breast adenocarcinomas.     

Ultrastructural study of membrane glycocalyx in primary and metastatic human and rat mammary carcinoma

The glycocalyx of primary and metastatic tumors was compared by ruthenium red staining and electron microscopy. Two systems were studied: human primary and metastatic breast tumors and rat primary and metastatic mammary carcinomas. A considerable diminution in the amount of glycocalyx was detected in both systems when primary tumors were compared with metastases. These results are consistent with observations of others showing that metastatic tumors shed glycoprotein antigens to the circulation; this may provide an immune escape mechanism for tumor cells, allowing their dissemination.     

Internal mammary lymphoscintigraphy in the assessment of patients with ovarian carcinoma

Radiocolloid internal mammary lymphoscintigraphy (IML) was evaluated in 364 patients with ovarian carcinoma to determine the frequency of abnormalities in post-operative patients, the association between the results of the lymphoscintigram and known clinical prognostic variables, and to establish whether IML yielded predictive information independent of these variables. Results of IML showed a correlation with established clinical prognostic features and yielded independent prognostic information. The sensitivity and specificity of IML in predicting relapse are 51% and 71% respectively, indicating that a single post-operative IML does not predict relapse or freedom from relapse with sufficient accuracy to make it a clinically useful test even though it provides an independent prediction of relapse.     

Pathology of metastasizing tumors in nitrosomethyl urea-induced rat mammary carcinoma

The metastatic capacity of rat mammary tumors induced with N-nitrosomethyl urea was tested in BUF/N inbred female rats by successive transplantation. After the first and second passage, tumor cells appeared diffusely distributed throughout the bone marrow and spleen, confirming results reported by others; no other metastases were observed. After six successive transplantations, large, well-defined tumor nodules were observed in the liver, spleen, lung, and the peritoneal surface of the intestines in 40% of the injected animals. The morphology of the primary and metastatic tumors was compared by light microscopy. The tumors appeared to be adenocarcinomas with differing degrees of differentiation. No morphlogical differences could be observed between the primary and the metastatic tumors.     

Ultrastructural localization of lactic dehydrogenase in mouse mammary carcinoma cells

Electron microscopic study of lactic dehydrogenase (LDH) was carried out in C3H mouse mammary carcinoma cells. Scattered cytoplasmic LDH granules were noted as well as around mitochondria and nuclear membrane. Control studies with normal breast tissues failed to show any activity. This observation suggests that LDH plays an important role in C3H mammary carcinoma and may be of use as an additional marker.     

Immunocytological localization of estrogen in human mammary carcinoma cells by horseradish--anti-horseradish peroxidase complex.

Tissues from 25 female and 2 male patients of mammary carcinoma were examined by the horseradish--anti-horseradish peroxidase complex to localize the presence of estrogen. Carcinoma cells of 10 females and 2 male patients showed positive staining by this technique. The nucleus and cytoplasmic membrane showed the reaction. This method is useful in identifying the exact location of the hormones or hormone-like substances in the malignant cells and, perhaps, will be of great help in selecting the patients for management.     

人树突状细胞与肝癌细胞系HLE融合细胞的构建

目的构建人源树突状细胞（DC）与肝癌细胞系HLE的融合细胞。方法含15％FCS的RPMI 1640培养HLE细胞,用GM—CSF和IL-4培养成人外周血单核细胞7d,并用TNF-α和PGE2促成熟2d后获得成熟DC;用荧光染料PKH67-GL（绿色荧光）和PKH26-GL（红色荧光）分别标记DC和HLE细胞,以50％聚乙二醇和10％二甲基亚砜为融合剂,构建可供流式细胞仪快速筛选的融合细胞。结果成功构建具有红、绿双色荧光的人源DC与HLE的融合细胞,融合率为16．8％。结论利用PKH67-GL和PKH26-GL为标记,可获得便于快速识别和筛选的DC与肝癌细胞的融合细胞,为使用融合DC疫苗治疗肝癌奠定了基础。     

Establishment and characteristics of two new human mammary carcinoma lines in nude mice with special reference to the estradiol receptor status and the importance of stroma forin vivo andin vitro growth

Summary Two new human mammary carcinoma lines originating from surgical material were established in nude mice. According to the adopted criteria, the tumor 4049 has been classified as estradiol receptor positive and mammary carcinoma 4296 as estradiol receptor negative. Both tumors proved to be c-erbB-2 protein positive and EGF-receptor negative. In contrast to carcinoma 4296, thein vitro growth and the take rate of mammary carcinoma 4049 in nude mice seems to be dependent on stromal components. Pretreatment of mice with estradiol/peanut oil before tumor engraftment was an essential precondition for the growth of the primary tumor in nude mice. After successful establishment the tumor growth was significantly stimulated by estradiol. The growth rate of mammary carcinoma 4296 was independent of any supplementation of estradiol. The two breast tumors were characterized with regard to their growth behaviour, histology, and sensitivity to cytostatics and antihormones. They are considered suitable tumor models for the testing of antineoplastic substances and for biological experiments.This work was supported by the Schering AG Berlin     

β-连环蛋白反义cDNA对肝癌细胞恶性表型的影响

目的：探讨应用反义核酸技术降低细胞内β—连环蛋白水平对人肝癌SMMC-7721细胞恶性表型的影响。方法：构建β—连环蛋白反义cDNA重组质粒，转染人肝癌SMMC—7721细胞，筛选β—连环蛋白低表达株，研究其恶性细胞表型的变化。结果：转染β—连环蛋白反义质粒后，低表达β—连环蛋白的SMMC—7721中c-myc基因表达降低，细胞形态向未转化方向变化，细胞生长受到抑制，软琼脂克隆形成率下降，细胞周期发生改变，G0—G1期增加，S期减少。结论：降低β—连环蛋白表达可显著抑制7721细胞的恶性表型。     

卵圆细胞标志分子在肝癌细胞株ＢＥＬ-７４０２中的表达及其意义

目的　探讨肝癌细胞株ＢＥＬ-７４０２的发生与卵圆细胞之间的分子关联及诱导分化前后的变化特征。方法　应用免疫细胞化学和酶细胞化学技术检测卵圆细胞的多种标志分子ＣＫ７、ＣＫ８、ＣＫ１８、ＣＫ１９、ＡＦＰ及ＧＧＴ在人肝癌细胞株ＢＥＬ-７４０２中的表达状态,并观察ＢＥＬ-７４０２诱导分化前后各种标志分子的表达变化特征。结果　ＢＥＬ ７４０２中ＣＫ７、ＣＫ８、ＣＫ１８、ＡＦＰ及ＧＧＴ表达阳性,ＣＫ１９表达阴性,与卵圆细胞向肝细胞分化早期阶段的分子表达谱相似。ＢＥＬ ７４０２诱导分化前后各分子标记物及ＧＧＴ酶活性的表达无明显改变。结论　ＢＥＬ ７４０２与卵圆细胞在分子表达谱上有高度相似性,提示肝细胞癌的发生与卵圆细胞之间存在重要关联。在诱导分化过程中,ＢＥＬ-７４０２标志分子表达水平的变化要晚于其在细胞周期方面的变化。     

Anti-tumor activity of a combination of plasminogen activator and captopril in a human melanoma xenograft model

Angiostatin, a proteolytic fragment of plasminogen consisting of the first 3 or 4 kringle domains, reduces tumor growth by specifically inhibiting tumor angiogenesis. Angiostatin is generated in vitro in a 2-step process. First, plasminogen is converted to plasmin by plasminogen activators. Next, plasmin excises the angiostatin fragment from plasminogen, a process requiring molecules that are able to donate a free sulfhydryl group. In this study, we investigated whether stimulation of in vivo angiostatin generation by administration of plasminogen activator and a free sulfhydryl group donor (FSD) has anti-tumor activity. First, we determined the optimal conditions for in vitro angiostatin generation by incubating murine plasma with different concentrations of plasminogen activator and/or the FSD captopril. Angiostatin generation was monitored by western blot analysis. Our results were extrapolated to the in vivo situation by administering the optimal dose of tissue-type plasminogen activator (tPA, i.v. injection 3 times/week) and captopril (in drinking water) to mice and analyzing the presence of angiostatin in the circulation. Angiostatin was readily detectable in mice receiving both tPA and captopril, but not in mice receiving either one of the agents. Finally, the anti-tumor activity of the tPA/captopril treatment was tested in a human melanoma xenograft model. Administration of tPA alone had only a marginal effect on tumor growth. Captopril alone reduced tumor growth by about 60%, whereas treatment with both captopril and tPA resulted in 83% inhibition of tumor growth.     

CGH analysis of ductal carcinoma of the breast with basaloid/myoepithelial cell differentiation

2-18% of ductal carcinoma-No Special Type (NST) are reported to express basal cell keratin 14 and such tumours may have a different metastatic pattern and prognosis. We performed immunohistochemistry for cytokeratins 19 (luminal) and 14 (basal) on 92 ductal carcinoma-NST. Those tumours showing CK14 expression were further characterized by immunohistochemistry for myoepithelial cell phenotype and analysed by comparative genomic hybridization. The 7 cases of ductal carcinoma-NST exhibiting a basal cell phenotype were all grade III tumours and showed a molecular cytogenetic profile similar to more conventional myoepithelial cell carcinomas. Therefore it appears that grade III invasive ductal carcinomas contain a subset of tumours with specific morphological and cytogenetic characteristics, and probably prognosis for the patient.     

姜黄素对人胃腺癌细胞株BGC-823生长抑制及诱导凋亡的作用

目的 探讨姜黄素对人胃腺癌细胞BGC-823的生长抑制及诱导凋亡作用。方法MTT法检测不同浓度姜黄素对人胃腺癌BGC-823细胞的生长抑制作用,计算半数抑制浓度（IC₅₀）;将1.2μmol／L姜黄素作用于BGC-823细胞24、48、72h,用DAPI染色检测细胞凋亡;用RT-PCR、Western blotting法分别检测姜黄素对Bax、Bcl-2基因以及Bax、Bcl-2、caspase-3蛋白的影响。结果 不同浓度的姜黄素作用于BGC-823细胞0～72h后,细胞呈不同程度的抑制作用,随着药物浓度的增加,抑制率明显上升,作用48h的IC₅₀为1.2μmol／L。DAPI染色可见典型的凋亡细胞形态学特征。RT-PCR、Western blotting结果显示1.2μmol/L姜黄素可以增加Bax表达、减少Bcl-2表达和激活caspase-3。结论 姜黄素对人胃腺癌BGC-823细胞有生长抑制和诱导凋亡的作用,这可能与增加Bax表达、减少Bcl-2表达、激活caspase-3有关。     

MAPK信号传导通路对人炎性乳腺癌细胞系侵袭能力的影响

目的:本研究探讨上皮钙粘蛋白(E-cadherin)基因显性负调控质粒(pcDNA3.1(-)H-2kd-E-cadherin)导入SUM149细胞系后,对丝裂原活化蛋白激酶信号传导系统(mitogenactivatedproteinkinasecascade,MAPK)的相关信号通路及调控机制的改变情况。方法:应用蛋白印迹法,检测了人炎性乳腺癌细胞系SUM149、E-cadherin基因显性负调控突变体高表达的SUM149阳性克隆中MAPK激酶活性的变化。结果:与对照组(未转染及空质粒组)相比,转染后并稳定高表达小鼠H-2kd阳性克隆的细胞中,磷酸化的细胞外信号调节激酶(extracellularsignalregulatedkinase,p-ERK1/2,phospho-P44/42)明显降低;而磷酸化P38激酶无显著变化。结论:在异常高的E-cadherin功能性表达人炎性乳腺癌细胞系SUM149中,下调上皮钙粘着蛋白表达明显抑制其侵袭能力。其可能通过下调丝裂原活化蛋白激酶信号传导系统MAPK中的磷酸化细胞外信号调节激酶(phos-extracellularsignalregulatedkinase)phos-Erk1/2降低基质金属蛋白酶MMP-1、MMP-9等表达,从而明显抑制其侵袭能力。