Establishment of molecular targeting therapy against ovarian cancer using human monoclonal antibody

人单克隆抗体卵巢癌分子靶向治疗的建立

• 批准号: 17591759
• 负责人: SUZUKI Nao
• 金额: $ 2.24万
• 依托单位: St. Marianna University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591759/
• 关键词: ovarian cancer; molecular targeting therapy; CA125; human monoclonal antibody; clear cell adenocarcinoma

Objective : In recent years, antibody therapy employing monoclonal antibodies has become a new approach for treating cancer. This study was performed to establish a human monoclonal antibody recognizing an epitope related to CA125 using KM mice and to assess its reactivity with ovarian cancer cells.Methods : A human ovarian clear cell adenocarcinoma cell line (RMG-I) was used to immunize KM mice, and hybridoma supernatant was obtained by a standard method employing ELISA screening. Next, selection of hybridomas was performed with two antibodies (MA602-1 and MA602-6) and a sandwich immunoassay for CA125-like antigen, and then the limiting dilution was used to obtain a human monoclonal antibody.Immunohistochemical reactivity of this antibody (HMOCC-2) with ovarian cancer was assessed, while its specificity was analyzed by Western blotting. Various antibodies were used to identify the epitope targeted by HMOCC-2. Finally, the antitumor effect of HMOCC-2 was assessed by intraperitoneal administration to SCID mice with heterografts of RMG-I tumors.Results : HMOCC-2 showed a positive reaction with 60% (63/105) of ovarian cancer specimens. Western blotting of the membrane fraction of RMG-I revealed several bands at 120 kDa to 250 kDa. HMOCC-2 recognized the CA125-like antigens identified by several antibodies. HMOCC-2 also exhibited significant antitumor activity (p<0.01) against ovarian cancer heterografts.Conclusion : HMOCC-2 reacts specifically with ovarian cancer cells via a target epitope analogous to that of CA125, and also exhibits activity against ovarian tumors. These findings suggest that it may have the potential to be employed clinically for molecular-targeting therapy.

目的：近年来，利用单抗进行抗体治疗已成为治疗癌症的一种新方法。本研究旨在利用KM小鼠建立识别CA125相关表位的人源性单抗，并检测其与卵巢癌细胞的反应性。方法：以人卵巢透明细胞腺癌细胞株(RMG-I)免疫KM小鼠，用ELISA法筛选杂交瘤细胞上清液。然后用两种抗体(MA602-1和MA602-6)和CA125样抗原的夹心免疫分析法筛选杂交瘤细胞，用极限稀释法获得人源性单抗，检测该抗体(HMOCC-2)与卵巢癌的免疫组织化学反应性，并用Western blotting分析其特异性。各种抗体被用来鉴定HMOCC-2靶向的表位。结果：HMOCC-2与60%(63/105)的卵巢癌标本呈阳性反应。Western blotting显示RMG-I的膜部分在120 kDa到250 kDa之间有几条带。HMOCC-2识别由几种抗体识别的CA125样抗原。结论：HMOCC-2通过与CA125类似的靶表位与卵巢癌细胞发生特异性反应，并具有抗卵巢肿瘤活性。这些发现表明，它可能有潜力用于临床的分子靶向治疗。