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红花水提液对人移行细胞和鼠成纤维细胞的毒性作用

红花水提液对人移行细胞和鼠成纤维细胞的毒性作用
红花水提液对人移行细胞和鼠成纤维细胞的毒性作用

Urological Oncology

Cytotoxic Effect of Saffron Stigma Aqueous Extract on Human Transitional Cell Carcinoma and Mouse Fibroblast

Behzad Feizzadeh,1 Jalil Tavakkol Afshari,2 Hassan Rakhshandeh,3 Alireza Rahimi,1 Azam Brook,2 Hassan Doosti 4

Introduction: Saffron has been suggested to have inhibitory effects on tumoral cells. We evaluated the cytotoxic effect of aqueous extract of saffron on human transitional cell carcinoma (TCC) and mouse non-neoplastic fibroblast cell lines.

Materials and Methods: Human TCC 5637 cell line and mouse fibroblast cell line (L929) were cultivated and incubated with different concentrations of aqueous extract of saffron stigma (50 μg/mL to 4000 μg/mL). Cytotoxic effect of saffron was evaluated by morphologic observation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay after 24, 48, 72, and 120 hours in each cell line.

Results: After 24 hours, morphological observations showed growth inhibitory effects at saffron extract concentrations higher than 200 μg/mL for L929 cells and at concentrations of 50 μg/mL to 200 μg/mL for the TCC cells. These changes became more prominent after 48 hours. However, significant growth inhibitory effects of the extract were shown at concentrations of 400 μg/mL and 800 μg/mL. Higher concentrations of saffron correlated inversely with cell population of both cell lines. Significant reduction of the survived cells was seen at concentrations of 400 μg/mL and 2000 μg/mL for TCC and L929 cell lines, respectively. After 120 hours, decrease in the percentage of survived cells at higher concentrations of saffron extract was seen in both cell lines. At a concentration of 800 μg/mL, the survived L929 cells plummeted to less than 60% after 120 hours, while no TCC cells survived at this time. No L929 cells survived at 2000 μg/mL.

Conclusion: Saffron aqueous extract has inhibitory effects on the growth of both TCC 5637 and normal L929 cell lines. This effect is dose dependent.

Urol J. 2008;5:161-7.

www.uj.unrc.ir

Keywords: Crocus sativus,

antineoplastic agents, transitional

cell carcinoma, fibroblast

1Department of Urology, Ghaem

Hospital, Mashhad University of Medical Sciences, Mashhad, Iran 2Immunology and Cell Culture Laboratory, Immunology Research Center, Bu-Ali Research Institute,

Mashhad, Iran

3Department of Pharmacology, Medical Plants Research Center, Mashhad University of Medical

Sciences, Mashhad, Iran

4Department of Statistics, Ferdowsi

University, Mashhad, Iran Corresponding Author:Behzad Feizzadeh, MD

Department of Urology, Ghaem

Hospital, Mashhad, Iran Tel: +98 511 841 7404Fax:+98 511 841 7404

E-mail: behzadfeizzadeh@https://www.sodocs.net/doc/0315841196.html,

Received May 2007Accepted June 2008

INTRODUCTION

Efforts to find any therapeutic options for cancers have guided the investigators to consider even herbal medicine to be tested. Treatment of bladder cancer was the subject of our interest that led us to study alternative therapies such as the use of herbs. Bladder cancer is the 5th

most common cancer with a high rate of mortality and morbidity.(1) Transitional cell carcinoma (TCC) is the most common bladder tumor which can be induced directly by cigarette smoking and environmental factors.(2)

Occupational exposure risk factors include aromatic amines, industrial

Saffron and Transitional Cell Carcinoma—Feizzadeh et al

dyes and solvents, plastic painting, rubber, heavy metals, mixtures of polycyclic aromatic hydrocarbones, etc.(3)

We sought to investigate saffron and its potential effect on cancerous cells. Saffron (Crocus Sativus L) is one of the worthiest perennial flowers with a violet color and usually 3 golden petal stigma in the Iridaceae family (Figure 1). It has been used as a food spice since the ancient times.(4,5)

Some of saffron’s chemical ingredients are carbohydrates, minerals, vitamins (especially riboflavin and thiamin), and pigments including crocin, anthocyanin, carotene, and lycopene.(5) Anticarcinogenic activity of saffron was reported in the beginning of 1990 and research on this subject has increasingly continued during the past decade.(6) Saffron and its main ingredients have shown antitumor and anticarcinogenic activities both in vitro and in vivo.(6,7) To date, however, there has not been any report in literature on saffron effects in bladder cancer. We studied in vitro cytotoxic effect of saffron aqueous extract on TCC cell line proliferation and non-neoplastic fibroblast cells of mouse as a normal cell line.

MATERIALS AND METHODS Preparation of Saffron Extract

Saffron harvested from saffron farms of Ghaen (a city in the northeast of Iran) was used in this study. Aqueous extract was prepared with 15 g of its ground petal stigma and 400 mL of distilled water in a Soxhlet extractor for 18 hours. The prepared extract was concentrated to 100 mL with a rotatory evaporator in low pressure and filtered through a 0.2-mm filter to be sterilized. The resultant solution was stored at 4°C to 8°C. Various concentrations of saffron (50 μg/mL, 100 μg/mL, 200 μg/mL, 400 μg/mL, 800 μg/mL, 1000 μg/mL, 2000 μg/mL, and 4000 μg/mL) and a control solution without saffron extract were prepared immediately and refrigerated before the experiments.

Morphologic Observation of Cell Lines Human transitional carcinoma cells (TCC 5637) and mouse fibroblast cell line (L929)

were provided from the National Cell Bank of Iran. The TCC cell line 5637 is an epithelial-

like adherent cell line originally taken from

the primary bladder carcinoma and L929 cell morphology is similar to fibroblast derived from mouse C3H/An connective tissue. Both of the cell lines were retrieved and cell passage was done. The viability of cells was determined by trypan blue test. Six well plates for TCC 5637 cells and similar plates for L929 cells were used. In each well, 5 × 105 neoplastic cells or 2 ×105 normal cells were placed. The cells were cultivated in Dulbecco’s Modified Eagle’s Medium (Sigma-Aldrich, St Louis, Missouri, USA) with 10% fetal calf serum (Gibco, Paisley, UK). The media were supplemented with 100 IU/mL of penicillin and 100 IU/mL of streptomycin (Jaberebn-e-Hayan, Tehran, Iran). The cells were incubated at 37°C in a humidified 5% CO

2

atmosphere for 24 hours. Then, exposing the cells to saffron extract was started: first, the media (2 mL capacity) were replaced with similar new media. Then the plates were incubated with different concentrations of saffron extract (zero to 4000 μg/mL) at 37°C in a humidified 5% CO

2

atmosphere for 24, 48, 72, and 120 hours, and the cells were observed under the light inverted microscope for morphological alterations. The observation was done 3 times

for each of the extract concentrations to check its reliability. Viability of cells throughout the experiment was always higher than 95% as

determined by trypan blue. Figure 1. Saffron and its stigma.

Saffron and Transitional Cell Carcinoma—Feizzadeh et al

Quantitative Assessment

In vitro cytotoxicity of saffron aqueous extract was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. This method was first

described by Mosmann in 1983 and modified by Alley and colleagues.(8,9) A total of 2000 normal cells and 5000 neoplastic cells from both cell lines were cultured after cellular passage and viability test in five 96-well plates. Every 3 well groups were marked for each concentration of extract and recorded in files as case and similarly as

control groups. The plates were incubated for 24 hours, and thereafter, the cells were exposed to the extract as follows: the first culture medium of each plate was changed by fresh culture medium (200 μL). Different concentrations of extract were prepared and added to 3 well groups, which contained TCC 5637 or L929 cell lines. No extract was added to the control group. Plates were incubated in a humidified 5% CO 2 atmosphere, and after 24 hours, 1 plate was chosen randomly and growth medium was removed. For each 200 μL of the growth medium, 25 μL of MTT solution was added (Sigma,

Missouri, USA) and incubated for 4 hours. After removing the growth medium and shaking microplates for 2 to 3 minutes, dissolvation of crystals in 200 μL of dimethyl sulfoxide and 25 μL of glycine buffer was achieved. The absorbance of formazan dye was recorded at 570 nm using enzyme-linked immunosorbent assay plate reader. The last stages were reported in the same manner for the second, third, and fourth plates after 48, 72, and 120 hours.

The optical density read from the extract treated wells was converted to a percentage of living cells against the control using the following formula:Surviving cells (%) compared to the controls = optical density of treated cells in each well × 100/mean optical density of control cells

Statistical Analyses

Data were analyzed by 1-way analysis of variance (ANOVA), followed by the Tukey multiple range tests for significant differences. The SPSS software (Statistical Package for the Social Sciences, version

11.5, SPSS Inc, Chicago, Ill, USA) was used for analyses. P values less than .05 were considered significant.

RESULTS

Morphological Alterations

L929 Cell Line. After 24 hours, saffron extract did not affect significantly the normal cells and they were intact in morphologic view. There were no changes in number, cytoplasm, and nucleus of the cells. However, in higher concentrations (> 200 μg/mL) decreased intercellular connections as the only notable alteration was apparent. After 48 hours, cell population increased at concentrations of 50 μg/mL, 100 μg/mL, and 200 μg/mL. At higher concentrations (400 μg/mL and 800 μg/mL), cytotoxic effects were prominent. Nearly, all cells were granulated, cell proliferation stopped, and cellular detachment was significant. After 72 to 120 hours, the process was followed similarly to the second day (Figure 2).

TCC 5637 Cell Line. After 24 hours, at the saffron extract concentrations of 50 μg/mL, 100 μg/mL, and 200 μg/mL, cell population decreased compared with the control group, and intercellular connections were also disrupted. At the concentrations of 400 μg/mL and

800 μg/mL, pigmentation increased and cellular detachment and vacuolization was apparent. At the concentration of 2000 μg/mL, 85% to 90% of cells were destroyed. After 48 hours, decrease in cell population and intercellular disruption, vacuolation, and pigmentation were apparent at concentrations of 50 μg/mL, 100 μg/mL, and 200 μg/mL. At the concentration of 800 μg/mL, most of the cells were destroyed. After 72 and 120 hours, all these alterations were significant (Figure 3).

Quantitative Results

Quantitative assessment was done by MTT assay. The results of the absorbance according to the extract concentration and cell population after 120 hours are shown in Figure 4. There was a significant correlation between the increasing extract concentration and decreasing of cell population. No survived cell was detected after

Saffron and Transitional Cell Carcinoma—Feizzadeh et al

120 hours at saffron extract concentrations of 2000 μg/mL and 400 μg/mL in the L929 and the TCC 5637 cell lines, respectively. In similar extract concentrations higher than 50 μg/mL, the percentage of survived TCC cells was less than survived L929 cells. Also, gradient of both curves in Figure 4 are the same after concentrations of 50

μg/mL up to 1000 μg/mL and 2000 μg/mL.

Figure 2. Effect of aqueous extract of saffron on L929 morphology at a concentration of 400 μg/mL. A is the control L929 and B to F ,

are the L929 cells after 24 hours, 48 hours, 72 hours, 96 hours, and 120 hours of exposure to saffron extract, respectively.

Figure 3. Effect of aqueous extract on TCC 5637 morphology at a concentration of 400 μg/mL. A is the control TCC 5637 and B to F , are the TCC 5637 cells after 24 hours, 48 hours, 72 hours, 96 hours, and 120 hours of exposure to saffron extract, respectively.

Saffron and Transitional Cell Carcinoma—Feizzadeh et al

In the beginning of the study, no significant difference was seen in cell population between the two cell lines. Therefore, both cell lines were enrolled to our study in similar conditions. Data analysis showed a good correlation between extract concentrations and cell viability in both cell lines during the study. Of course, this was more significant in the TCC cell line on the first day of the study (r = 0.9, P = .001). After 24 hours, cell population decreased in correlation with increasing extract concentrations, but the decrease was more significant in the TCC cells compared to the L929 cells. In both cell lines, correlation between increasing concentration and percentage of survived cells was significant (P = .001, R 2 = 0.88, and β = -0.00003 for TCC; P = .004, R 2 = 0.771, and β= -0.00006 for L929). After 120 hours, decrease in the percentage of the survived cells due to increasing concentration of saffron extract was seen in both cell lines, and at the concentrations of 800 μg/mL and 1000 μg/mL, the relation was linear. There was a significant correlation between increasing

concentration and the percentage of the survived cells in both cell lines (P < .001, R 2 = 0.453, and β = -0.0001 for TCC; P = .001, R 2 = 0.398, and β = -0.0002 for L929).

DISCUSSION

Treatment of bladder cancer is based on the stage of cancer. In lower stages, treatment includes

resection and also intravesical therapies, especially with bacillus Calmette-Guerin. Other antitumor agents can be helpful, but extensive research is required to confirm their clinical applicability. We demonstrated in vitro cytotoxic effect of saffron on human TCC cell lines. In a review of the literature, we found no report of saffron extract effects on TCC cell lines.

Saffron is a plant which grows mostly in Spain and Iran, and in a smaller scale in Greece, Turkey, India, and some other countries.(10) Saffron is usually used as a food spice, but some other effects such as anticarcinogenic effect, decreasing blood pressure, and controlling tonic-clonic and absence seizures have been reported so far.(5) In addition, saffron is used in cosmetic products.(11) There are several reports on the anticarcinogenic effects of saffron.(6,7) In a research on ethanolic extract of saffron on Hela cells (cervix epitheloid carcinoma cells), Abdullaev and Frenkel documented the a

significant inhibitory effect of colony formation and intracellular DNA and RNA synthesis.(12) They performed another study on A549 cells (lung adenocarcinoma cells), WI-38 (normal lung fibroblast-like cells), and VA-13 (WI-38 cells which were transformed by SV-40 viruses), and showed that malignant cells were more sensitive to the inhibitory effect of saffron on DNA and RNA synthesis in comparison with normal cells.(13)

The involved chemical ingredients in the

antitumor effect of saffron has been investigated by some researchers. In one study, it was shown that crocin isolated from saffron inhibits PC-12 (rat’s pheochromocytoma cell line) cell growth with increased synthesis of glutathione.(14) It was also shown that saffron inhibited the carcinogenesis caused by chemical substances in mouse’s skin, which was probably due to modulator of phase 2 of detoxification enzymes such as glutathione peroxidase, catalase, and superoxide desmutase.(15) In one research on chemoprevention,(16) saffron ingredients were separated by high performance liquid

chromatography and photodiode array methods; 12 chemical ingredients were tested by colony

formation assay: crocin-1, crocin-2, crocin-3,

Figure 4. Effect of aqueous extract of saffron on the percentage of survived TCC 5637 and L929 cells after 120 hours.

Saffron and Transitional Cell Carcinoma—Feizzadeh et al

trans-crocin-2, trans-crocin-3, trans-crocin-4,

cis-crocin-3, 4-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde-diglycosil-kaempferol, picrocrocin, acid form of picrocrocin, safranal, and crocetin. In vitro inhibitory effect of some extracted ingredients on different types of human malignant cells was observed. In addition, no toxic or mutagenic effect was seen, and the authors concluded that saffron could be used as a chemopreventor in clinical studies.(16) Antitumor mechanism of saffron is not well understood to the present time; however, different hypotheses have been proposed for its mechanism, eg, inhibitory effects of free radical chain reactions. Saffron includes carotenoid ingredients which are fat solvable and can

act as free radical inhibitors.(17) Inhibition of intracellular DNA and RNA synthesis without any effect on protein synthesis has been reported as a role for carotenoid ingredients of saffron.(18) Researchers have suggested transformation of carotenoid to retinoid, interaction of carotenoid with topoisomerase II (the enzyme which interferes in DNA-protein interactions),(19)

and absorption of extracellular fluid due to swelling and local membrane envagination.(20) Saffron also contains lectins which may cause antitumor effects of saffron.(21) In addition, apoptosis is induced by crocin.(22) In a research

on PC-12 cells, crocin caused inhibition of cell growth by its effects on tumor necrosis factor-alpha.(14) However, our knowledge on the exact mechanisms of antitumor effect of saffron needs to be expanded to weigh up its clinical usage.

CONCLUSION

Our study showed that saffron aqueous

extract has an in vitro inhibitory effect on the proliferation of human TCC and mouse L929 cells which is dose dependent.

ACKNOWLEDGMENT

We would like to thank the research Deputy

of Mashhad University of Medical Sciences

for financial support and Mrs Yaghoti, the secretary of department of urology, for her kind cooperation.CONFLICT OF INTEREST

None declared.

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细胞毒性药物配制方法及使用时注意事项

抗肿瘤药物的用药顺序及溶媒选择 原则 (1)药物相互作用原则 有的化疗药物之间会发生相互作用,从而改变药物的体内过程,可能影响疗效或毒性。 如顺铂影响紫杉醇的清除率,先用紫杉醇再用顺铂。 (2)刺激性原则 使用非顺序依赖性化疗药物时,应先用对组织刺激性较强的药物,后用刺激性小的药物。由于治疗开始时静脉尚未损伤,结构稳定性好,药业渗出机会少,药物对静脉引起的不良 反应较小如长春瑞滨和顺铂合用时,长春瑞滨刺激性强,宜先给药。 (3)细胞动力学原则 生长较慢的实体瘤处于增殖期的细胞较少,G0期细胞较多,先用周期非特异性药物杀 灭一部分肿瘤细胞,使肿瘤细胞进入增殖期再用周期特异性药物。顺铂和依托泊苷合用时,先用顺铂后用VP-16。 生长快的肿瘤先用周期特异性药物大量杀灭处于增殖周期的细胞,减少肿瘤负荷,随后用周期非特异性药物杀灭残存的肿瘤细胞。 用药顺序 1、联用顺铂化疗 化疗方案联用药物用药顺序原因 GP 吉西他滨先用GEM 顺铂会影响吉西他滨的体内过程,加重骨髓抑制。TP 紫杉醇先用PTX 顺铂对细胞色素P450酶有调节作用,可使PTX清除 率大约降低33%,产生更为严重的骨髓抑制 FP 5-FU 先用DDP 小剂量DDP能够增加细胞内蛋氨酸, 使细胞内活性叶酸生成增加, 从而增加5-FU的抗肿瘤作用。 PP 培美曲塞先用Alimta,30min后用顺铂说明书 2、联合长春新碱化疗 化疗方案联用药物用药顺序原因 CHOP 环磷酰胺先用VCR,6-8小时后在给CTX VCR具有同步化作用,使细胞停滞在M期,约6~8h后细胞同步进入G1期,再用CTX可增效 VCM 甲氨蝶呤先用VCR VCR阻止甲氨蝶呤从细 胞内渗出而提高细胞内浓度 VDLP 门冬酰胺酶先用VCR 合用加重神经系统血液系统毒性,先于门冬12~24小时给药 3、甲氨蝶呤 化疗方案联用药物用药顺序原因 CMF 5-FU 用MTX4~6h后用5-FU 序贯抑制 MTX----二氢叶酸还原酶抑制 剂 5-FU-----胸腺嘧啶合成酶抑制剂

细胞毒性药物配制方法及使用时注意事项

原则 (1)药物相互作用原则 有的化疗药物之间会发生相互作用,从而改变药物的体内过程,可能影响疗效或毒性。如顺铂影响紫杉醇的清除率,先用紫杉醇再用顺铂。 (2)刺激性原则 使用非顺序依赖性化疗药物时,应先用对组织刺激性较强的药物,后用刺激性小的药物。由于治疗开始时静脉尚未损伤,结构稳定性好,药业渗出机会少,药物对静脉引起的不良反应较小如长春瑞滨和顺铂合用时,长春瑞滨刺激性强,宜先给药。 (3)细胞动力学原则 生长较慢的实体瘤处于增殖期的细胞较少,G0期细胞较多,先用周期非特异性药物杀灭一部分肿瘤细胞,使肿瘤细胞进入增殖期再用周期特异性药物。顺铂和依托泊苷合用时,先用顺铂后用VP-16。 生长快的肿瘤先用周期特异性药物大量杀灭处于增殖周期的细胞,减少肿瘤负荷,随后用周期非特异性药物杀灭残存的肿瘤细胞。 用药顺序 1、联用顺铂化疗 化疗方案联用药物用药顺序原因 GP 吉西他滨先用GEM 顺铂会影响吉西他滨的体内过程,加重骨髓抑制。 TP 紫杉醇先用PTX 顺铂对细胞色素P450酶有调节作用,可使PTX清除率大约降低33%,产生更为严重的骨髓抑制 FP 5-FU 先用DDP 小剂量DDP能够增加细胞内蛋氨酸, 使细胞内活性叶酸生成增加, 从而增加5-FU的抗肿瘤作用。 PP 培美曲塞先用Alimta,30min后用顺铂说明书 2、联合长春新碱化疗 化疗方案联用药物用药顺序原因 CHOP 环磷酰胺先用VCR,6-8小时后在给CTX VCR具有同步化作用,使细胞停滞在M期,约6~8h后细胞同步进入G1期,再用CTX可增效 VCM 甲氨蝶呤先用VCR VCR阻止甲氨蝶呤从细胞内渗出而提高细胞内浓度 VDLP 门冬酰胺酶先用VCR 合用加重神经系统血液系统毒性,先于门冬12~24小时给药

细胞毒性T细胞作用的分子机制

第四章 细胞毒性T 细胞作用的分子机制 免疫系统针对病原所产生的免疫应答分为两大类:以抗体为主体介导的中和细胞外病原体的体液免疫反应和以细胞毒性T 细胞(CTL )为主体介导的特异杀伤被感染靶细胞的细胞免疫反应。其中细胞免疫反应对于彻底地杀灭病原体、清除被感染的“改变”了的自身细胞显得尤为重要。细胞免疫反应包括NK 细胞等介导的非特异性靶细胞杀伤和CTL 为主、Th 细胞为辅所介导的特异性靶细胞杀伤。CTL 对于被感染细胞的MHC I 类分子限制特异性的杀伤是细胞免疫应答的重要内容,其研究对于了解免疫识别、免疫杀伤以及新型疫苗的分子设计都有重要意义。 第一节 CTL 作用概述 CTL 即杀伤性T 细胞,是一类具有CD8+表面标志、受MHC I 类分子限制性杀伤功能的T 细胞。CTL 的重要功能是可以特异性地杀伤靶细胞。CTL 介导的靶细胞杀伤的特点是:杀伤受TCR 以及MHC I 类分子的严格限制。CTL 对靶细胞的杀伤还具有特异性、程序性和快速性的特点。另外,IL-2和其它一些细胞因子在CTL 前体的体外培养和效应CTL 的分化诱导中也起着重要作用。 一、CTL 的主要生物学功能 CTL 对感染了病原的靶细胞杀伤构成了细胞免疫的重要部分。CTL 在识别“改变”了的自身细胞,如病毒感染细胞、恶性细胞和移植反应中的移植细胞等起着非常重要的作用。由于人体所有的有核细胞都表达I 类MHC 分子,因此,CTL 原则上可以识别和清除几乎所有改变了的自身细胞。 二、CTL 作用的MHC 限制性 CTL 的杀伤作用受MHC 严格限制。CTL 在杀伤抗原特异性靶细胞过程中,不识别可溶性抗原或者与非自身MHC I 类分子结合的抗原,而只能识别与自身MHC I 类分子相联系的特异性抗原多肽。 三、CTL 的组成 CTL 的命名是根据体外与一定比例的特异性靶细胞孵育后杀伤一定百分率的靶细胞这一功能来确定的。因此,CTL 不是一种特定的细胞,而是一个具有特异性杀伤活性的T 细胞群体。在组成上,它包括CD8+T 细胞和CD4+T 细胞。 1、CD8+ T 细胞 主要有αβTCR 型CD8+T 细胞和γδTCR 型CD8+T 细胞。前者以αβTCR 识别靶细胞表面上的MHC I 类分子-肽复合物(图4- );后者则以γδTCR 识别靶细胞表面的 HLA-I HLA-II 图4-1 TCR-抗原肽-HLA 三分子复合物 αβ TCR αβ TCR

CDC ADCC细胞毒性

1 Antibody-dependent cellular cytotoxicity (ADCC)抗体依赖的细胞介导的细胞毒性作用 In antibody-dependent cellular cytotoxicity (ADCC), Fc gamma receptors (FcγR or FCGR) on the surface of immune effector cells bind the Fc region of an antibody, itself specifically bound to a target cell. The cells that can mediate ADCC are nonspecific cytotoxic cells such as natural killer cells, macrophages, monocytes and eosinophils. Upon FCGR binding to the antibody, the FCGR ITAM is phosphorylated, which triggers the activation of the effector cell and the secretion of various substances (lytic enzymes, perforin, granzymes, TNF) that mediate the destruction of the target cell. The level of ADCC effector function is high for human IgG1 and IgG3, low for IgG2 and IgG4, and for these last two subclasses, the level of binding depends on the FCGR isotype and on the cell type. 2 Complement-dependent cytotoxicity (CDC) 补体依赖的细胞毒性作用 In complement-dependent cytotoxicity (CDC), the C1q binds the antibody and this binding triggers the complement cascade which leads to the formation of the membrane attack complex (MAC) (C5b to C9) at the surface of the target cell, as a result of the classical pathway complement activation.

特异性抗原诱导的细胞毒性T细胞功能测定

一、基本原理 本方法先借助长期混合淋巴细胞培养法获得抗原特异性CTL,然后再进行细胞毒试验。其原理为:外周血淋巴细胞包含针对不同抗原的特异性CTL克隆,在体外经某一特定(或同种异体细胞)抗原刺激后,能识别该抗原的T细胞克隆被选择性激活、增殖,而其他T细胞克隆则逐渐死亡;经3~4次刺激后,存活的均为识别特异性MHC/抗原肽复合物的细胞,即抗原特异性CTL 。 二、试剂及材料 1. 丝裂霉素C(Sigma):用培养液或PBS配制300μg/ml。 2. 含20%的新生牛血清的RPMI 1640 3. EB病毒转化的B淋巴母细胞株 三、操作方法 1. 特异性CTL的诱导和制备 ①取作者外周血分离PBMC,无血清1640洗两遍,用含20%的新生牛血清的RPMI 1640调成1.5×106 /ml,置于24孔板中,于5% CO2 培养箱中4小时使单核细胞贴壁以去除之,然后收集细胞,计数; ②取EB病毒转化的B淋巴母细胞,加入丝裂霉素C,最终浓度为30μg/ml,于37℃水浴中作用30min,1000r/min离心10min,弃上清,沉淀细胞用1640液洗涤3次并计数; ③取2×106 个PBL于24孔板中,加入5×104 (2.5%)个经丝裂霉素C处理(30mg/ml、30min)的自身、同种异体(其HLA-I类型别完全不同)的EBV-LCL细胞作为刺激细胞,混匀,用完全培养基(RPMI 1640)补总体积至2ml; ④静置于培养箱中;4d后半量换液,继续培养3d; ⑤离心收集细胞,取1×106 个反应细胞,加入2×105个(20%)的刺激细胞,第三天加入重组IL-2,使终浓度为30U/ml;每三天半量换液一次并维持相同IL-2浓度。 ⑥每周按相同程序刺激效应细胞一次,3~4次后,效应细胞即为特异性CTL,可用于杀伤实验。 2. 细胞毒试验 检测CTL细胞毒作用均可采用检测NK细胞杀伤活性的方法,仅效靶细胞比例不一样,现将LDH释放法简要叙述如下:

细胞毒性机理

槟榔的细胞毒理研究进展 肝细胞毒性: 单细胞凝胶电泳技术检测出槟榔碱会引起DNA损伤和G0/G1细胞周期阻滞,从而抑制正常肝细胞增殖 槟榔碱可以通过破坏小鼠肝细胞的超微结构而导致肝毒性: 槟榔碱的肝细胞受体细胞核体积减小、核膜凹陷、核周的异染色质富集,预示着细胞核组分有失活的趋势,是肝细胞凋亡的前兆;粗面内质网上潴泡和脂肪滴过量,对蛋白质的合成造成了影响;线粒体嵴扩张,反映出细胞器氧化还原系统的紊乱 血清中的肝毒性标志酶丙氨酸氨基转移酶、天冬氨酸氨基转移酶和碱性磷酸酶含量随着槟榔碱剂量的增加明显上调 肝脏中的谷胱甘肽巯基转移酶活性随着槟榔碱剂量的增加而增大,导致肝脏的解毒功能降低,使得肝脏更容易受到病毒的侵袭 乌头碱对新生大鼠心肌培养细胞损伤的研究 彗星电泳,也称之为单细胞凝胶电泳技术,检测单细胞损伤与修复 乌头碱的中毒机制主要为抑制心肌细胞膜电压门控型Na+通道失活,使Na+持续内流、延长细胞膜除极化时程而引发严重的心律失常 乌头碱对新生大鼠心肌培养细胞损伤的研究:采用单细胞凝胶电泳检测不同剂量乌头碱染毒前后心肌细胞内损伤,并采用软件分析 乌头碱对大鼠心肌培养细胞。表达的影响 乌头碱对大鼠心肌培养细胞调控蛋白表达的影响 六价铬的细胞毒理效应及其机制研究进展 从Cr(VI)导致胞内活性氧累积效应、诱发细胞凋亡、导致细胞癌变、毒理效应的基因组学研究等几方面, 论述了Cr(VI)对人体和动物的细胞毒理效应及其作用机制。 MTT比色法 比色法是一种常用的检测细胞存活和生长的方法。原理为活细胞线粒体中的琥泊酸脱氢酶能使外源性还原为不溶于水的蓝紫色结品甲瓒并沉积在细胞中,而死细胞不会如此。能溶解细胞中的甲瓒,用酶联免疫检测仪在波长处测定其吸光值,可间接反映活细胞数量。在一定细胞数范围内,结晶形成的量与活细胞数成正比。

细胞毒理学

细胞毒理学及其研究方法 公共卫生学院劳动卫生教研室金亚平 定义: 毒理学(Toxicology)是研究外源性物质对生命有机体损伤作用规律及其机制的一门学科。 细胞毒理学(Cytotoxicology): 是研究外源性物质对生命细胞损伤作用规律及其机制的一门毒理学分支学科。 研究内容 细胞毒理学是以培养细胞为研究对象进行毒理学研究的一门科学,它主要是应用体外模型对外界环境中有害因子(物理、化学和生物)进行监测,评价其对人体可能产生的危害。 研究有害因子的一般毒性作用 判断外源性有害因子对细胞的一般毒性及评价可能引起的潜在毒性作用。 可通过光学显微镜/电镜及其他方法,直接观察体外培养细胞受损的性质与程度,如细胞的形态学改变、贴壁性差、生长速度减弱、细胞退化、死亡及完整性受损等。 已知对人类有毒性作用的大多数药物或毒物,在体内与体外的毒性效应是一致的。 研究有害因子的特异毒性作用 从哺乳动物或人体的不同组织器官分离出不同类型的细胞。用以筛检不同毒物对不同细胞的毒性。有害因子诱变作用及致癌作用: 体外培养细胞,特别是哺乳动物的离体细胞已广泛应用于体外测试诱变和致癌的试验中,其包括基因点突变、染色体畸变、姊妹染色单体互换、染色体显带、DNA 损伤、程序外DNA合成和细胞恶性转化等。如砷的致癌作用。 研究有害因子在细胞内的代谢 体外培养细胞可能是研究毒物代谢最合适的体外试验模型。体外细胞培养避免了体内复杂因素(如神经-内分泌、营养物质等)的干扰,可以按研究者预先设计的需要,来严格控制有害因子的剂量及与细胞接触的时间。可以直接检测、分析细胞内代谢的改变,容易了解毒物代谢与毒性之间的量-效关系。如砷体内代谢等。 研究有害因子的毒作用机制 也是研究有害因子毒性作用机制的最合适的材料。如用已建立的体外细胞转化系统研究辐射及化学致癌物诱发细胞癌变的机制,用血管上皮细胞和星形胶质细胞的体外培养系统研究毒物对血脑屏障的损伤,用巨噬细胞和成纤维细胞组成的体外培养系统,研究二氧化硅致矽肺纤维发生、发展过程及其作用机制。 用于药物的筛选、进行药效学评价 可用于研究药物的作用、毒副反应及其作用机制,为选择疗效好、毒副反应小的药物提供资料,在此研究基础上,对疗效好、毒性小的初筛药物,再用动物实验模型加以验证。 细胞毒理学发展简史 细胞毒理学作为毒理学的一个分支学科出现是近10多年的事。因此,它是一门较新的学科。 其优点: (1) 可以按实验要求控制实验条件,把整个实验安排在体外进行,在体外直接观察到细胞形态发生的改变,便于了解毒物与毒性作用之间的关系。 (2) 实验条件易于控制,可严格控制作用物的剂量和作用时间,排除体内复杂的神经-内分泌因素的干扰,实验结果稳定,重复性好。 (3) 操作简便,不需要复杂的大型仪器设备,实验经济。 (4) 可同时提供大量的生物学性状相同的细胞系(株)作为研究对象,避免了动物间的个体差异,实验易重复。 局限性: 因为细胞是在离开机体整体环境下,独立生长在体外环境中,其生物学性状多少会发生某些改变,

细胞毒性试验总结

(一)实验前应明确的问题 1.选择适当的细胞接种浓度。一般情况下,96孔培养板的一内贴壁细胞长满时约有105个细胞。但由于不同细胞贴壁后面积差异很大,因此,在进行MTT试验前,要进行预实验检测其贴壁率、倍增时间以及不同接种细胞数条件下的生长曲线,确定试验中每孔的接种细胞数和培养时间,以保证培养终止致细胞过满。这样,才能保证MTT结晶形成酌量与细胞数呈的线性关系。否则细胞数太多敏感性降低,太少观察不到差异。 2.药物浓度的设定。一定要多看文献,参考别人的结果再定个比较大的范围先初筛。根据自己初筛的结果缩小浓度和时间范围再细筛。切记!否则,可能你用的时间和浓度根本不是药物的有效浓度和时间。 3. 时间点的设定。在不同时间点的测定OD值,输入excel表,最后得到不同时间点的抑制率变化情况,画出变化的曲线,曲线什么时候变得平坦了(到了平台期)那个时间点应该就是最好的时间点(因为这个时候的细胞增殖抑制表现的最明显)。 4.培养时间。200ul的培养液对于10的4~5次方的增殖期细胞来说,很难维持68h,如果营养不够的话,细胞会由增殖期渐渐趋向G0期而趋于静止,影响结果,我们是在48h换液的。 5.MTT法只能测定细胞相对数和相对活力,不能测定细胞绝对数。做MTT时,尽量无菌操作,因为细菌也可以导致MTT比色OD值的升高。 6.理论未必都是对的。要根据自己的实际情况调整。 7.实验时应设置调零孔,对照孔,加药孔。调零孔加培养基、MTT、二甲基亚砜。对照孔和加药孔都要加细胞、培养液、MTT、二甲基亚砜,不同的是对照孔加溶解药物的介质,而加药组加入不同浓度的药物。 8.避免血清干扰。用含15%胎牛血清培养液培养细胞时,高的血清物质会影响试验孔的光吸收值。由于试验本底增加,会试验敏感性。因此,一般选小于10%胎牛血清的培养液进行。在呈色后,尽量吸净培养孔内残余培养液。 (二)实验步骤 贴壁细胞: 1.收集对数期细胞,调整细胞悬液浓度,每孔加入100ul,铺板使待测细胞调密度至1000-10000孔,(边缘孔用无菌PBS填充)。 2.5%CO2,37℃孵育,至细胞单层铺满孔底(96孔平底板),加入浓度梯度的药物,原则上,

细胞毒性T细胞作用的分子机制

第四章细胞毒性T细胞作用的分子机制 免疫系统针对病原所产生的免疫应答分为两大类:以抗体为主体介导的中和细胞外病原体的体液免疫反应和以细胞毒性T细胞(CTL)为主体介导的特异杀伤被感染靶细胞的细胞免疫反应。其中细胞免疫反应对于彻底地杀灭病原体、清除被感染的“改变”了的自身细胞显得尤为重要。细胞免疫反应包括NK细胞等介导的非特异性靶细胞杀伤和CTL为主、Th细胞为辅所介导的特异性靶细胞杀伤。CTL对于被感染细胞的MHC I类分子限制特异性的杀伤是细胞免疫应答的重要内容,其研究对于了解免疫识别、免疫杀伤以及新型疫苗的分子设计都有重要意义。 第一节CTL作用概述 CTL即杀伤性T细胞,是一类具有CD8+表面标志、受MHC I类分子限制性杀伤功能的T细胞。CTL的重要功能是可以特异性地杀伤靶细胞。CTL介导的靶细胞杀伤的特点是:杀伤受TCR以及MHC I类分子的严格限制。CTL对靶细胞的杀伤还具有特异性、程序性和快速性的特点。另外,IL-2和其它一些细胞因子在CTL前体的体外培养和效应CTL的分化诱导中也起着重要作用。 一、CTL的主要生物学功能 CTL对感染了病原的靶细胞杀伤构成了细胞免疫的重要部分。CTL在识别“改变”了的自身细胞,如病毒感染细胞、恶性细胞和移植反应中的移植细胞等起着非常重要的作用。由于人体所有的有核细胞都表达I类MHC分子,因此,CTL原则上可以识别和清除几乎所有改变了的自身细胞。 二、CTL作用的MHC限制性 CTL的杀伤作用受MHC严格限制。CTL在杀伤抗原特异性靶细胞过程中,不识别可溶性抗原或者与非自身MHC I类分子结合的抗原,而只能识别与自身MHC I类分子相联系的特异性抗原多肽。 三、CTL的组成 CTL的命名是根据体外与一定比例的特异性靶细胞孵育后杀伤一定百分率的靶细胞这一功能来确定的。因此,CTL不是一种特定的细胞,而是一个具有特异性杀伤活性的T细胞群体。在组成上,它包括CD8+T细胞和CD4+T细胞。 1、CD8+ T细胞主要有TCR型CD8+T 细胞和TCR型CD8+T细胞。前者以TCR识别靶细胞表面上的MHC I类分子-肽复合物(图1 );后者则以TCR 识别靶细胞表面的 HLA-I HLA-II 抗原肽 抗原肽CD4+ αβ TCR CD8+

细胞毒药物使用的指南

细胞毒性药物指在生物学方面具有危害性影响的药品,可通过皮肤接触或吸入等方式造成包括生殖系统、泌尿、肝肾系统的毒害,还有致畸或损害生育功能。由于其在人体作用强度大,刺激性强,在发挥治疗作用的同时,也同时影响了正常细胞的生长繁殖。 肿瘤化疗药物几乎都是细胞毒性药物,在杀死肿瘤细胞的同时,对人体的正常细胞有一定的毒副作用,尤其是对分裂、增殖、比较快的细胞如骨髓造血细胞、胃肠道粘膜上皮细胞等。因此在有效的肿瘤化疗中,毒副作用几乎是不可避免的。另外还有一些如耳毒性抗菌素生素等,都具有细胞毒性作用。 1. 抗肿瘤药的合理应用 (1)临床医师必须熟知抗肿瘤药的抗瘤谱、药动学、不良反应、药物相互作用,使用规,合理地应用抗肿瘤药。 (2)周期非特异性药物对癌细胞的作用较强而快,高浓度下能迅速杀灭癌细胞;周期特异性药物的作用需要一定时间才能发挥其杀伤作用。周期非特异性药物的剂量反应曲线接近直线,在机体能耐受的毒性限度,其杀伤能力随剂量的增加而增加。在浓度和时限的关系中,浓度是主要因素。周期特异性药物则不然,其剂量反应曲线是一条渐近线,即在小剂量时类似于直线,达到一定剂量后不再上升,出现平台。相对来说,在影响疗效的浓度与时间的关系中,时间是主要的因素。因此,为使化疗药物能发挥最大的作用,非特异性药物宜静脉一次推注,而特异性药物则以缓慢滴注、肌注射或口服为宜。 (3)联合化疗方案中一般应包括两类以上药理作用机制不同的药物,且常用周期特异性药物与作用于不同时相的周期特异性药物配合。选药时也要尽可能使各药的毒性不相重复,以提高正常细胞的耐受性。 (4)经典的肿瘤治疗追求扩大根治的手术、强化或冲击化疗、根治性放疗等,然而往往事与愿违。迄今为止,上述治疗所能达到的最高疗效仅仅是临床治愈,肿瘤的复发和转移仍是一个难以解决的问题,且患者治疗后普遍出现生存质量下降,甚至因不能耐受继续治疗而死亡。随着治疗中的手段的进步,使癌症治疗出现了质的飞跃,已经有可能将肿瘤当成慢性病对待,就像糖尿病、高血压等慢性病那样,肿瘤患者也可带瘤长期生存。对中晚期肿瘤患者应以“提高患者生活质量,延长生命时间”为目标进行综合治疗。 2.抗肿瘤药的主要不良反应与防治原则 抗肿瘤药的不良反应涉及以下几方面: (1)骨髓抑制:表现在白细胞、血小板、红细胞和血红蛋白下降。除新碱和博来霉素外几乎所有的细胞毒药,均会导致骨髓抑制。骨髓抑制常常出现在给药后的7~10天,但是某些药物可出现得更晚,如卡莫司汀、洛莫司汀和美法仑。在一次治疗前必须检查外周末梢血象。如骨髓功能尚未恢复,应酌情减少用药剂量或推迟治疗。 对中性白细胞减少,或由此带来的发热患者,应当应用重组粒细胞集落刺激因子(G-CSF),必要时考虑给予抗菌药物治疗。 (2)消化道反应:包括食欲减退、恶心、呕吐、腹泻、腹痛、腹胀、肝脏毒性等。对轻度消化道反应可口服多立酮、甲氧氯普胺进行处理,如效果不佳,可合并应用地塞米松或劳拉西泮作为补充。对严重呕吐或处理效果不佳者,可给予5-羟色胺3(5HT3)受体拮抗剂,包括昂丹司琼、格拉司琼、雷莫司琼、托烷司琼和帕洛诺司琼。为预防迟发症状,可口服地塞米松,可以单独使用,或与甲氧氯普胺、苯海拉明联合应用。 (3)口腔黏膜反应:如咽炎、口腔溃疡、口腔黏膜炎,黏膜反应是肿瘤化疗中常见的一种并发症,多数情况都与氟尿嘧啶、甲氨蝶呤和蒽环类抗生素有关。防止和处理这些并发症,应进行有效的口腔护理(经常洗漱口腔)。 (4)脱发:抗肿瘤药引起的脱发几乎在1或2周后产生。对于脱发,迄今尚无药理学上的防治方法,国外曾探索使用冰帽等措施。

金纳米粒子的细胞毒性(三):胞吞作用

金纳米粒子的细胞毒性(三):胞吞作用 2016-08-16 12:54来源:内江洛伯尔材料科技有限公司作者:研发部 纳米颗粒的大小及其表面配体在细胞胞吞过程中的作用 实际上在研究AuNPs和细胞的作用时,胞吞作用(endocytosis),即颗粒进入细胞的作用过程,是第一位要研究的现象。大体分来,胞吞作用可分为吞噬作用(phagocytosis)、胞饮作用(pinocytosis)以及受体介导胞吞作用(receptor-mediated endocytosis,RME)。吞噬作用是以大的囊泡形式(常称为液泡)内吞直径达几微米的固体复合物、微生物以及细胞碎片等的被噬取过程。胞饮作用是指以小的囊泡形式将细胞周围的微滴状液体(直径一般小于1微米,常含有离子或小分子)吞入细胞内的过程。胞饮作用不具有明显的专一性。这种胞吞常常造成细胞的坏死而形成坏死细胞(necrotic cells)。受体介导的胞吞作用是指被内吞物(称为配基) 与细胞表面的专一性受体相结合,并随机引发细胞膜的内陷,形成的囊泡将配基裹入并输入到细胞内的过程,它是一种专一性很强的胞吞作用。AuNPs的内吞属于受体介导的胞吞作用,具有很强的专一选

择性。在研究纳米颗粒和细胞的相互作用过程中,RME是第一位要考虑的机理,一个外来的配基结合细胞表面上的受体而进入细胞。细胞表面上受体的浓度以及受体和配基的作用力决定了胞吞的强度。温度对RME也有重要影响,例如在低温时金纳米颗粒将不进入细胞,而是贴在细胞膜上。 在研究AuNPs的胞吞作用时,上面提到的两个因素,即颗粒大小和吸附在颗粒表面的配基性质具有极为重要的意义,后者能和细胞表面上的蛋白受体相结合从而进入细胞。当研究AuNPs的尺寸因子和表面改性的影响时,首先要观察的是AuNPs是否进入了细胞,AuNPs在细胞内的分布以及能否形成聚集体等问题。 Huang等,Oh等和De等利用电子显微镜研究了AuNPs在进入细胞后在各个部位的分布,并作了十分细致的工作。例如Huang等利用静脉注射研究了2,6和15 nm AuNPs在小鼠的肿瘤细胞内的分布,所用的是巯丙酰甘氨酸(Tiopronin)保护的AuNPs。他们发现2 nm和6 nm的AuNPs能分布在癌细胞的胞质和细胞核中,而15 nm AuNPs只在胞质中存在,而且形成了聚集体。Chithrani等用电镜研究发现包覆有柠檬酸的AuNPs是通过RMS机理进入Hela 细胞的,并证明了当AuNPs颗粒的直径等于50 nm时,AuNPs进入Hela细胞的数目达到最大值,在此之后,进入细胞的数目变少。 Jiang等在研究AuNPs对细胞的作用时,利用5,10和25 nm由聚乙烯吡咯烷酮(PVP)保护的AuNPs,以及AuNPs的自由聚集体和在固体表面上固定的聚集体对Hela细胞的活性进行了研究,证明了粒径在50 nm以下的AuNPs能被细胞胞吞,并对细胞产生毒性的事实。同时发现,其中被胞吞的大粒径AuNPs比小颗粒易于形成聚集体,从而具有更大的毒性。但当颗粒太大(或者在细胞外形成聚集体)无法进入细胞时,反而会促进细胞的生长。

细胞毒药物使用指南

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