两种不同抗体双弹头标记物导向治疗肝癌的比较

在动物实验的基础上，比较了抗ＡＦＰ单克隆抗体（ｍＡｂ）和抗ＡＦＰ多克隆抗体（ｐＡｂ）两种不同抗体双弹头标记物在肝癌患者体内的生物代谢情况。结果显示，两种抗体标记物的血浆清除半衰期均在２４ｈ左右，ｍＡｂ标记物的清除较ｐＡｂ标记物略慢。尿清除的半衰期，ｍＡｂ标记物约为１２０ｈ，而ｐＡｂ标记物则约为１８ｈ，表明二者的体内生物代谢不同，疗效可能不一。     

单克隆抗体药物治疗肿瘤的研究现状与展望

单克隆抗体 (简称单抗 )药物用于治疗肿瘤的研究已获得重要进展。抗肿瘤单抗药物一般包括单抗治疗剂与单抗偶联物。研究表明 ,单抗药物对肿瘤相关靶点显示特异性结合 ,对肿瘤细胞有选择性杀伤作用并在动物实验有显著的疗效。单抗药物已开始应用于临床肿瘤治疗。抗肿瘤单抗药物研究的发展趋势是继续寻求新的分子靶点、抗体人源化以及偶联物分子的小型化。由于单抗有高度特异性 ,研制单抗药物有巨大的潜力 ,单抗药物将在肿瘤治疗中发挥重要作用。     

肿瘤靶向抗体偶联物的研究进展

肿瘤靶向制剂已成为当今肿瘤治疗研究的热点,针对特定的靶点(抗原)可以制备相应的单抗。特异性单抗和蛋白毒素、放射性同位素、化疗药物偶联制备成相应的靶向抗体药物,这种抗体偶联物能增强药物的有效性,减少对正常组织的毒害。本文就三类肿瘤靶向抗体偶联物的特点、作用机制、上市药物以及发展趋势进行综述。     

Ablation of Breast Cancer Cells Using Trastuzumab‐Functionalized Multi‐Walled Carbon Nanotubes and Trastuzumab‐Diphtheria Toxin Conjugate

Trastuzumab (Herceptin^®) is a monoclonal antibody (mAb) for specific ablation of HER2‐overexpressing malignant breast cancer cells. Intensification of antiproliferative activity of trastuzumab through construction of immunotoxins and nano‐immunoconjugates is a promising approach for treatment of cancer. In this study, trastuzumab was directly conjugated to diphtheria toxin (DT). Also, conjugates of trastuzumab and multiwalled carbon nanotubes (MWCNT) were constructed by covalent immobilization of trastuzumab onto MWCNTs. Then, antiproliferative activity of the fusion constructs against HER2‐overexpressing SK‐BR‐3 and also HER2‐negative MCF‐7 cancer cell lines were examined. Cells treated with trastuzumab‐MWCNT conjugates were irradiated with near‐infrared (NIR) light. Efficient absorption of NIR radiation and its conversion to heat by MWCNTs can be resulted to thermal ablation of cancerous cells. Our results strongly showed that both trastuzumab‐MWCNT and trastuzumab‐DT conjugates were significantly efficient in the specific killing of SK‐BR‐3 cells. Targeting of MWCNTs to cancerous cells using trastuzumab followed by exposure of cells to NIR radiation was more efficient in repression of cell proliferation than treatment for cancer cells with trastuzumab‐DT. Our results also showed that conjugation linkers can significantly affect the cytotoxicity of MWCNT‐immunoconjugates. In conclusion, our data demonstrated that trastuzumab‐MWCNT is a promising nano‐immunoconjugate for killing of HER2‐overexpressing cancerous cells.     

抗人胸腺细胞球蛋白与柔红霉素交联方法及其偶联物体外抗肿瘤作用

分别用12.5％、25.0％、50.0％、75.0％和100.0％氧化的Dex T_(10)作为交联剂交联抗人胸腺细胞球蛋白(AHTG)和柔红霉素(DNR)形成免疫偶联物(AHTG-Dex-DNR),其中以25.0％氧化的DexT10作为交联剂最佳。它既提高了偶联物的交联度,又降低了硼氢化钠对AH-TG和DNR活性的损伤。偶联物对靶细胞CEM 24h细胞毒试验LD_(50)为10.68μg/ml。对非靶细胞K562仅有轻微杀伤作用,10min细胞毒试验为特异的杀灭肿瘤细胞试验,对CEM的LD_(50)为14.79μg/ml,对K562几乎无细胞毒作用,表明免疫偶联物有特异性细胞毒作用。     

抗肿瘤抗生素抗体靶向药物研究新进展

新近研究发现,卡里奇霉素、力达霉素等抗肿瘤抗生素对某些靶点显示高度活性,对癌细胞具有极强的杀伤作用,可以作为高效＂弹头＂药物,用于构建抗体靶向药物,包括化学免疫偶联物和融合蛋白。抗体靶向药物由于体内分布的特异性及作用的专一性,具有强大的抗肿瘤优势。本文主要对几类抗肿瘤抗生素抗体靶向药物的构建及作用特点等进行综述,并初步展望其未来研究方向。     

FLT3 Antibody‐based therapy for leukemia

Technological advances in antibody generation and production have facilitated recent clinical and commercial success with antibody‐based cancer therapeutics. The class III receptor tyrosine kinase FLT3 is highly expressed on the blast cells in most cases of acute myelogenous leukemia (AML) and B‐cell acute lymphoblastic leukemia (ALL). Activating mutations of FLT3 are detected in approximately 37% AML patients. FLT3 expression in normal tissue is limited to myeloid and B‐cell precursor cells. Therefore, over‐expressed or mutated FLT3 is an attractive target for therapeutic intervention using monoclonal antibodies. This review will discuss recent progress in the development of anti‐FLT3 antibodies as well as their therapeutic potentials in the treatment of AML and other hematological malignancies. Drug Dev. Res. 67:495–500, 2006. © 2006 Wiley‐Liss, Inc.     

Effect of vitamin D analog (1alpha hydroxy D5) immunoconjugated to Her-2 antibody on breast cancer

We previously showed that a new vitamin D analog, 1alpha(OH)D5 (D5), induced differentiation and inhibited the growth of breast cancer cells. In this report, we examined whether D5 specifically delivered to breast cancer cells could have any therapeutic effect. D5 was linked to Her-2 antibody using sulfosuccinimidyl 6-4 azido nitrophenylamido hexanode (SANPAH) as a linker. The Her-2 antibody selected in our study had no significant effect on the in vitro or in vivo growth of breast cancer cells; however, it had cell-differentiating action. In vitro, D5-Her-2 antibody conjugate (IMC) showed the ability to specifically bind to Her-2-expressing cells, to compete with Her-2 antibody for surface receptor and to cause internalization. IMC (equivalent to 5 microg Her-2 antibody given intraperitoneally once weekly for 6 weeks) significantly inhibited the growth of BT-474 cells transplanted into athymic mice. The in vivo growth-inhibitory effect of IMC treatment was similar to that observed in animals receiving D5 continuously as a dietary supplement. These results show that the targeted delivery of D5 by immunoconjugation to cell surface receptor antibodies may be of potential therapeutic value for the treatment of Her-2 positive breast cancer.     

Localization and Biodistribution of Conjugate ATG－Dex－DNR in Nude Mice as Models for Human Leukemia

ＬｏｃａｌｉｚａｔｉｏｎａｎｄＢｉｏｄｉｓｔｒｉｂｕｔｉｏｎｏｆＣｏｎｊｕｇａｔｅＡＴＧ－Ｄｅｘ－ＤＮＲｉｎＮｕｄｅＭｉｃｅａｓＭｏｄｅｌｓｆｏｒＨｕｍａｎＬｅｕｋｅｍｉａＺＨＡＮＧＤｏｎｇ－ｈｕａ（张东华），ＴＡＮＧＪｉｎ－ｚｈｉ（唐锦治），ＬＩＺ...