New transcatheter arterial embolization therapy for unresectable hepatocellular carcinoma using ferromagnetic iron-dextran reagents combined with anticancer drug and bispecific antibody

为了观察不可切除的肝脏肿瘤的命运，我们计划通过经动脉途径栓塞肿瘤供血动脉，使用新型栓塞剂，铁磁性铁-葡聚糖沿着逆转录霉素（RM）-A，这是一种促有丝分裂抑制剂和靶向肝癌细胞和LAK细胞的双特异性抗体。这种复合物形成胶体，通过在肿瘤部位周围产生磁场将其保持在肿瘤部位。针对新的肝动脉栓塞成分，我们合成了两种双特异性抗体（BsAbs），（OKXL）用OKT-3（抗CD-3）和L-7 - 6（抗HCC）两者构建的BsAbs，和（3GXL）用3-G-8（抗CD-16）和L-7 - 6抗体通过化学重建方法构建的BsAbs。MTT法检测不同条件下的细胞毒性。当用FACS检查时，这两种在其单个分子上具有成对结合臂的BsAb显示出与亲本单克隆抗体（0KT-3、3-G-8、L-7 - 6）类似的靶细胞结合。新近设计的体外细胞毒试验显示，LAK或PWM模拟的LAK（PWM-LAK）细胞对HCC细胞没有任何明显的细胞毒活性，而在BsAb（OKXL）存在下，效应细胞的有效重靶向效应细胞的效应/靶比均为0.3。由于PWM-LAK细胞在体外增殖比LAK细胞快3 - 5倍，使用PWM-LAK细胞与（OKXL）BsAb组合的过继免疫治疗应该是非常有希望的。

With the aim to see the fate of unresectable tumor of the liver, we are planning to embolize the tumor feeding artery via transcatheteric route by novel embolus, ferromagnetic iron-dextran along with Reveromycine (RM) - A, which is a mitogenic inhibitor and bispecific antibody targeting for both hepatoma cells and LAK cells. This complex forms a colloid which will held at tumor site by creating a magnetic field around the tumor site. For the component of novel transcatheteric hepatic arterial embolus, we synthesized two kinds of bispecific antibodies (BsAbs), i.e., (OKXL) BsAbs constructed with both OKT-3 (anti-CD3) and L-7-6 (anti-HCC), and (3GXL) BsAbs constructed with 3-G-8 (anti-CD-16) and L-7-6 antibodies by chemical reconstruction method. The cytotoxicity was tested by MTT assay in several conditions. These two BsAbs, having pairs of binding arms on their single molecule, showed similar binding to target cells as the parental monoclonal antibodies (OKT-3, 3-G-8, L-7-6), when examined with FACS. Newly devised in vitrocytotoxicity tests revealed that LAK or PWM-simulated LAK (PWM-LAK) cells did not show any significant cytotoxic activity to HCC cells, while both effector/target (0.3) in the presence of BsAbs (OKXL) for the efficient retargeting of the effector cells. Inasmuch as PWM-LAK cells proliferate in vitro 3-5 times faster than LAK cells, adoptive immunotherapy using PWM-LAK cells in combination with (OKXL) BsAbs should be very promising.