Increase in carcinoembryonic antigen release from cancer cells by combined treatment with retinoic acid and low-temperature hyperthermia

The growth of a human gastric adenocarcinoma cell line, MKN-45, was inhibited and the amount of carcinoembryonic antigen (CEA) in both the culture medium and the cell extract was increased in the presence of retinoic acid at a concentration of 75 (1?5×)-125 μM (1?9×), which did not substantially affect cell survival. Treatment using a combination of retinoic acid (125 μM) and low-temperature hyperthermia (40°C, 30 min) was more effective in increasing CEA compared with retinoic acid alone (extracellular 1?9-2?4×, intracellular 1?5-1?9×). The inhibition of cell growth was reversed after the retinoic acid was removed from the medium. Cells treated with both retinoic acid and (low-temperature) hyperthermia, however, could be induced to release a significant amount of CEA at about 48 h after retinoic acid removal. The induced CEA increase in the cells, but not in the medium, was suppressed by actinomycin D (1 ng/ml) or cyclohexamide (0-2μg/ml). These results suggest that retinoic acid, used alone or in combination with hyperthermia, enhances the production and release of CEA in human gastric cancer cells.     

血清癌胚抗原联合糖类抗原19-9检测对胰腺癌筛查的临床价值评估

目的 研究血清癌胚抗原(CEA)联合糖类抗原19-9(CA19-9)检测对胰腺癌筛查的临床价值.方法 将103例胰腺癌患者作为胰腺癌组,选取同期收治的105例胰腺炎患者以及健康体检的97例健康人群作为胰腺炎组及健康对照组.对比治疗前3组血清CEA、CA19-9水平,以及手术前后胰腺癌患者血清CEA、CA19-9水平;对...     

血清甲胎蛋白联合癌胚抗原检测对肝癌的诊断价值

目的 探讨血清甲胎蛋白(AFP)联合癌胚抗原(CEA)检测对肝癌的诊断价值.方法 将160例肝癌患者作为观察组,再将同时期160例健康体检者作为对照组,检测两组患者的血清AFP、CEA水平和肝功能情况.比较不同肝功能、肿瘤直径和临床分期肝癌患者血清AFP、CEA水平,分析血清AFP联合CEA检查的诊断效能.结果 观察组患者AFP、CEA表达水平均明显高于对照组(P﹤0.01),观察组中肝功能异常患者AFP、CEA表达水平均明显高于肝功能正常患者(P﹤0.01).肿瘤直径≥5 cm患者血清AFP、CEA表达水平均明显高于肿瘤直径﹤5 cm患者(P﹤0.01).肿瘤分期为Ⅲ～Ⅳ期患者血清AFP、CEA表达水平均明显高于Ⅰ～Ⅱ期患者(P﹤0.01).受试者工作特征(ROC)曲线分析结果显示,血清AFP联合CEA检测的约登指数为0.850,灵敏度为90.00％,特异度为95.00％,曲线下面积(AUC)为0.939.结论 肝功能异常患者中AFP、CEA表达水平较高,其表达水平对临床诊断肝癌具有参考价值,两者联合检测肝癌具有较高的灵敏度和特异度.     

Dynamics of carcinoembryonic antigen in patients with stomach cancer during treatment with cryotherapy

Radioimmunologic assays of blood serum carcinoembryonic antigen (CEA) level were conducted at major stages of treatment of gastric cancer by subtotal stomach resection and gastrectomy with preliminary cryotreatment and thawing of tumor. A short-term rise in CEA level occurred in 53.9% of cases 3-4 days after combined therapy. A decrease in CEA concentration at discharge from hospital as compared with preoperative level and that registered 3-4 days after operation was observed in 50 and 75% of cases of combined therapy, respectively, and 47.5 and 37.5% of controls (surgery without cryotreatment). There was no correlation between cryotreatment and changes in CEA level in gastric ulcer patients.     

藻蓝蛋白协同全反式维甲酸影响人宫颈癌HeLa细胞的增殖和凋亡

目的：探讨全反式维甲酸（all-transretinoic acid,ATRA）和钝顶螺旋藻藻蓝蛋白（C-phycocyanin,C-PC）联合用药对人宫颈癌HeLa细胞繁殖和凋亡的影响及其诱导细胞凋亡可能的分子机制。 方法： 实验分4组：对照组,C-PC组,ATRA组,C-PC+ATRA联合用药组。MTT法检测ATRA和C-PC单独及联合用药对HeLa细胞增殖的影响并计算它们的IC50,TUNEL法检测单独及联合用药后HeLa细胞凋亡情况,免疫组化法检测Bcl-2的表达,Westren blotting法检测Caspase-3的表达。 结果： ATRA和C-PC均具有抑制HeLa细胞增殖的作用,IC50分别为（0.158± 0.036）mmol/L和（192.75± 5.79）μg/L。采用不同浓度的ATRA分别联合40或80 μg/L C-PC处理HeLa细胞,ATRA的IC50分别为（0.095±0.007）mmol/L和（0.062±0004）mmol/L,明显低于ATRA单独用药时的IC50值;当达到相同的抑制率时,联合C-PC用药可以显著降低ATRA的使用剂量。与对照组相比,两种药物单独用药增加了HeLa细胞凋亡水平（IOD C-PC=63.12, IOD ATRA=59.98, P <0.05）;当两种药物联合用药时,凋亡水平增加更加显著（IOD=89.52, P <0.01）。两药联合使用后HeLa细胞显著下调Bcl-2和上调Caspase-3的表达水平（均 P <0.01）。 结论： ATRA和C-PC联合用药可抑制HeLa细胞增殖和诱导其凋亡,其分子机制可能是通过抑制Bcl-2表达、促进Caspase-3表达来实现的。     

Non-proteolytic release of carcinoembryonic antigen from normal human colonic epithelial cells cultured in collagen gel

Recent studies have shown that, even with a minimal content of carcinoembryonic antigen (CEA), normal human colonic epithelial cells express substantial amounts of CEA mRNA and colonic mucosal fragments cultured in vitro produce CEA quite actively, indicating that CEA should no longer be considered to be of an oncofetal nature. To understand the basis of the usefulness of CEA as a tumor marker, we analyzed the release of CEA, a glycosyl-phosphatidylinositol (GPI)-anchored protein, from colonic epithelial cells, by culturing isolated colonic crypts in collagen gel. The crypts appeared to preserve their morphological and biochemical integrity in the gel for at least 16 hr, and released CEA spontaneously. Three forms of CEA—spontaneously released CEA, CEA liberated with phosphatidylinositol-specific phospholipase C (PI-PLC) and CEA in cell lysates—were indistinguishable on SDS-PAGE. This is in contrast to recombinant CEA spontaneously released from CHO transfectants, which showed a smaller molecular mass than that of PI-PLC-cleaved recombinant CEA. By phase separation using Triton X-114, CEA in the cell lysates of crypts was separated mostly into the detergent phase, while the spontaneously released and the PI-PLC-cleaved CEA were separated into the aqueous phase. When the cells were metabolically labeled with the precursors of the GPI-anchor, ³H-ethanolamine but not JH-palmitic acid was found in the spontaneously released CEA. These findings suggest that, in contrast to the proteolysis-like release of the recombinant CEA from CHO cells, CEA in normal colonic epithelial cells is released by a non-proteolytic cleavage, which probably occurs through the action of some endogenous phospholipase. © 1994 Wiley-Liss, Inc.     

Epitopes of carcinoembryonic antigen defined by monoclonal antibodies prepared from mice immunized with purified carcinoembryonic antigen or HCT-8R cells

A library of 18 monoclonal antibodies (MAbs) reactive with purified carcinoembryonic antigen (CEA) has been prepared. The specificity of these MAbs was tested and they have been separated into nine subgroups, each recognizing a different region of the CEA molecule. Seven MAbs from four of the groups also react with the nonspecific cross-reacting antigen. Some of the MAbs are directed against conformational determinants: three of the MAb groups bind poorly to sodium dodecyl sulfate-treated CEA, while five of the groups are not reactive with reduced and alkylated CEA. Three of the groups react with purified CEA but not with the cell surface CEA of HCT-8R cells, while the other groups react with both forms. The MAbs were tested for binding to fragments of CEA obtained by chemical cleavage and the groups of MAbs were found to react with different subsets of such fragments.     

全反式维甲酸诱导食管癌细胞凋亡的实验研究

目的探讨全反式维甲酸(ATRA)诱导食管癌EC9706细胞凋亡的作用及其机制。方法用不同浓度的ATRA处理EC9706细胞,采用四甲基偶氮唑盐(MTT)法检测ATRA对EC9706细胞的增殖抑制效应;采用流式细胞仪和原位末端标记(TUNEL)法检测细胞周期的变化和凋亡率;采用免疫组化S-P法,检测凋亡相关基因caspase-3和bcl-2的蛋白表达,并用病理图像分析软件进行半定量分析。结果ATRA对EC9706细胞有增殖抑制和诱导凋亡的作用;流式细胞仪检测显示,在G1期之前可出现Sub-G1峰,凋亡率最高为(32.6±0.4)%,并有浓度和时间依赖性;TUNEL法显示凋亡小体形成;EC9706细胞在凋亡过程中,凋亡相关基因caspase-3的蛋白表达增强,bcl-2的蛋白表达减弱。结论ATRA作用于食管癌EC9706细胞后将引起细胞凋亡的增加,这主要与ATRA能促进caspase-3的活化,并下调bcl-2的蛋白表达有关。     

全反式视黄酸对癌细胞凋亡的诱导

探讨全反式视黄酸对乳腺癌细胞生长抑制对细胞凋亡诱导的机理。方法；采用荧光显微术，流式细胞，ＭＴＴ测定和ＲＮＡ印迹等方法，检测细胞凋亡，细胞生长和ｍＲＮＡ的表达水平。结果；１）ＡＴＲＡ能够有效地诱导ＺＲ－７５－１乳腺癌细胞凋亡，但不能诱导ＭＤＡ－ＭＢ－２３１乳腺癌细胞凋亡。２）ＡＴＲＡ能够有效地抑制ＺＲ－７５－１细胞的生长，但不能抑制ＭＤＡ－ＭＢ－２３１细胞生长 ；３）ＡＴＲＡ能够诱导ＺＲ－７５－１     

Expression of carcinoembryonic antigen in fresh human gastric cancer cells assessed by flow cytometry

The expression of carcinoembryonic antigen (CEA) by tumor cells from freshly excised human gastric cancers was investigated using flow cytometry (FCM). Highly purified fresh human cancer cells were obtained from solid tumors in 20 patients and from malignant ascites in 6 patients. Thirteen of the 26 tumors were positive for CEA by FCM. CEA expression was more common in well-differentiated tumors than in poorly differentiated tumors. CEA expression was investigated by both FCM and immuno-histochemistry in 9 patients, and the two methods agreed in 8 of them. However, quantitative evaluation of CEA expression could only be performed by FCM and not by immunohistochemical staining. FCM could analyze the expression of CEA not only on the cell membrane but also in the cytoplasm, by using gastric cancer cells with or without Triton X-100 treatment. Thus, this study showed that CEA expression can be determined and evaluated quantitatively by FCM. © 1993 Wiley-Liss, Inc.     

Effects of cyclic adenosine 3':5'-monophosphate upon glycoprotein and carcinoembryonic antigen synthesis and release by human colon cancer cells

The role of cyclic adenosine 3':5'-monophosphate (cAMP) in the regulation of the synthesis and release of glycoproteins and of carcinoembryonic antigen by colon cancer cells was studied using LS174T cells in vitro. Adenylate cyclase and cAMP phosphodiesterase activities were assessed by measuring cellular cAMP in response to forskolin and cholera toxin (adenylate cyclase activators) and to 3-isobutyl-1-methylxanthine (a phosphodiesterase inhibitor). Each agent increased cAMP levels significantly. Dibutyryl-cAMP (1 mM) stimulated glycoprotein synthesis and release when [3H]fucose was used as a precursor. The synthesis and release of carcinoembryonic antigen, a membrane-associated glycoprotein antigen, was also significantly increased by these test agents. A close dose-response relationship existed for forskolin and for cholera toxin between cAMP generation and carcinoembryonic antigen release. cAMP may play a role in regulating the synthesis and release of glycoprotein antigens by colon cancer cells.     

Increase in cell surface antigen expression by leukemic cells following in vitro treatment with papain

A variety of enzymes have been used to increase the immunogenicity of tumor cells in syngeneic hosts, including neuraminidase, trypsin and papain. The results of the investigation presented here suggest that, under defined conditions, in vitro treatment by papain of living cells from a Gross virus induced leukemia results in a quantitative modification of the antigens expressed at the cell surface without any detectable qualitative modification. Cells from the W/Fu C58(NT)D leukemia (leukemia induced in W/Fu rats by the Gross agent) were submitted to a moderate in vitro treatment by papain. Antisera were raised in syngeneic W/Fu rats immunized with W/Fu C58 (NT)D cells, either untreated (G-typing serum) or papain treated. The cytotoxic activity of both of these types of antisera was assessed on W/Fu C58 (NT)D cells, untreated or papain treated. Target cells treated with papain showed an increased susceptibility to lysis by antibody in the presence of complement. Cross-absorption studies showed that the activity towards papain-treated target cells could be absorbed out with untreated W/Fu C58 (NT)D cells and was not affected by absorption with papain-treated normal lymphocytes.Hence papain treatment appears to induce an increase in antigen expression at the cell surface, rather than the unmasking of “cryptantigens”, and this could be of interest in producing antibodies against weak antigens.     

维甲酸α受体介导全反式维甲酸抑制胃癌细胞生长的作用机理

目的 探讨维甲酸α受体（ＲＡＲａ）介导全反式维甲酸（ＡＴＲＡ）抑制胃癌细胞生长的作用机理。方法 应用Ｎｏｔｈｅｒｎ ｂｌｏｔ分析维甲酸受体在胃癌细胞中的表达水平,通过脂质体转染方法将ｓｅｎｓｅ ＲＡＲａ和ａｎｔｉｓｅｎｓｅ ＲＡＲａ分别转染到细胞中,通过ＭＴＴ方法和软琼脂集落形成实验分析ＡＴＲＡ对转染细胞生长和恶性程度的影响,瞬时转染和测定氯霉素乙酰转移酶（ＣＡＴ）活性,分析维甲酸应答元件（ＲＡＲ     

术前中性粒细胞与淋巴细胞比值联合癌胚抗原检测对直肠癌患者预后的评估价值

目的探讨术前中性粒细胞与淋巴细胞比值(NLR)联合癌胚抗原(CEA)对直肠癌预后的评估价值。方法选取268例直肠癌患者,依据术后5年生存情况,分为生存组和死亡组,比较两组患者的临床特征,影响直肠癌患者预后的独立影响因素采用Cox回归分析,采用受试者工作特征(ROC)曲线和曲线下面积(AUC)评估NLR及CEA单独及联合检测对直肠癌预后的评估价值。结果随访结束,268例直肠癌患者中,生存156例,病死112例,直肠癌患者术后5年生存率为58.21%。将生存患者和病死患者分别作为生存组和死亡组,生存组和死亡组直肠癌患者性别、年龄比较,差异均无统计学意义(P﹥0.05);生存组和死亡组直肠癌患者TNM分期、分化程度、肿瘤直径、神经侵犯情况、浸润深度、远处转移情况、淋巴结转移情况、CEA水平及NLR比较,差异均有统计学意义(P﹤0.05)。Cox回归分析结果显示,TNM分期、肿瘤直径、远处转移、CEA水平和NLR是直肠癌患者预后不良的独立危险因素(P﹤0.05)。CEA、NLR及二者联合预测直肠癌预后的AUC分别为0.991、0.923、0.997,CEA和NLR联合检测对直肠癌患者的预后评估具有较高的准确性,二者联合检测的AUC高于单独预测的AUC(P﹤0.05)。结论术前NLR联合CEA检测对直肠癌预后具有较高的预估价值,二者联合能够为评估直肠患者预后提供重要的参考信息。     

Drug-induced modulation of carcinoembryonic antigen (CEA) expression in neoplastic cells from a patient with rectal cancer

Treatment with 5-fluorouracil (5-FU) or recombinant interferon-gamma (IFN), alone or in combination, was found to increase carcinoembryonic antigen (CEA) expression in several carcinoma cell lines. In this study we examined the in vitro effect of these agents on CEA expression of tumor cells, obtained from a patient operated for rectal cancer. The results showed that exposure of cancer cells to 5-FU or to IFN resulted in increased CEA levels in terms of percentage of CEA-positive cells and mean fluorescence values, as indicated by FACS analysis. However, drug combination did not induce CEA expression higher than that provided by single agents alone. Treatment with 5-FU or with IFN produced a reduction of the total number of viable cells. Moreover, Western blot analysis revealed that exposure of cancer cells to each drug was followed by a substantial increase of the total cellular CEA content. On the contrary, 5-FU in combination with IFN did not increase the expression of the antigen more than that obtained by single agents. Noteworthy, exposure of CEA-negative cells from adjacent normal rectal tissue to both agents alone or in combination, did not result in CEA induction. In conclusion, the present results suggest new approaches aimed at (a) increasing the sensitivity of diagnostic procedures based on detection of CEA-positive tumor cells; (b) facilitating the recognition of CEA-positive cancer cells by immune responses induced by anti-CEA peptide vaccines.