Kubota Yutaro, Zhao Ming, Han Qinghong, Aoki Yusuke, Masaki Noriyuki, Obara Koya, Morinaga Sei, Mizuta Kohei, Sato Motokazu, Bouvet Michael, Kubota Koichi, Tsunoda Takuya, Hoffman Robert M
AntiCancer Inc., San Diego, CA, U.S.A.
Department of Surgery, University of California, San Diego, CA, U.S.A.
Cancer Genomics Proteomics. 2025 Mar-Apr;22(2):247-257. doi: 10.21873/cgp.20499.
BACKGROUND/AIM: We previously developed A1-R, which selectively targets and kills tumors. In the present study, we established recombinant methioninase (rMETase)-producing A1-R (A1-R-rMETase), by transfer of the gene, to target methionine addiction of syngeneic-cancer mouse models.
A plasmid containing the gene was extracted from METase-producing recombinant and inserted into A1-R using electroporation. Lewis Lung Carcinoma (LLC) cells (10) were injected subcutaneously in male C57BL/6 mice aged 4-6 weeks. We determined that 10 A1-R-rMETase administered iv was a safe dosage in C57BL/6 mice and was used for efficacy studies on LLC tumors in C57BL/6 mice. Tumor size was measured with calipers three times per week for 3 weeks. On day 22, tumor methionine levels were measured using HPLC in the control mice injected with phosphate-buffered saline (PBS) and the mice injected with A1-R-rMETase.
The mean LLC tumor size of each group on day 22 was as follows: PBS control: 741.5 mm; mice injected with A1-R: 566.3 mm (=0.370); and mice injected with A1-R-rMETase: 198.8 mm (=0.0003 control and =0.0117 A1-R). The mice injected with A1-R-rMETase showed a significantly lower mean tumor methionine level than mice injected with PBS (5.9 nM/mg protein 11.1 nM/mg protein, =0.0095). A1-R-rMETase grew continuously in the tumors but not in the liver or spleen.
Tumor-targeting A1-R engineered to express the gene, inhibited LLC tumor growth in a syngeneic mouse model and reduced the methionine level in the tumor. A1-R-rMETase combines the tumor targeting and killing capability of A1-R plus rMETase which targets the methionine addiction of cancer.
背景/目的：我们之前研发了A1-R，它能选择性地靶向并杀死肿瘤。在本研究中，我们通过基因转移构建了产生重组蛋氨酸酶（rMETase）的A1-R（A1-R-rMETase），以针对同基因癌症小鼠模型的蛋氨酸成瘾现象。
从产生METase的重组体中提取含该基因的质粒，用电穿孔法将其插入A1-R。将10个Lewis肺癌（LLC）细胞皮下注射到4至6周龄的雄性C57BL/6小鼠体内。我们确定静脉注射10个A1-R-rMETase对C57BL/6小鼠是安全剂量，并用于对C57BL/6小鼠LLC肿瘤的疗效研究。每周用卡尺测量肿瘤大小3次，持续3周。在第22天，使用高效液相色谱法测量注射磷酸盐缓冲盐水（PBS）的对照小鼠和注射A1-R-rMETase的小鼠的肿瘤蛋氨酸水平。
第22天每组LLC肿瘤的平均大小如下：PBS对照组：741.5立方毫米；注射A1-R的小鼠：566.3立方毫米（P = 0.370）；注射A1-R-rMETase的小鼠：198.8立方毫米（P = 0.0003对比对照组，P = 0.0117对比A1-R组）。注射A1-R-rMETase的小鼠的肿瘤蛋氨酸平均水平显著低于注射PBS的小鼠（5.9纳摩尔/毫克蛋白质对比11.1纳摩尔/毫克蛋白质，P = 0.0095）。A1-R-rMETase在肿瘤中持续生长，但在肝脏或脾脏中不生长。
经基因工程改造以表达该基因的肿瘤靶向性A1-R，在同基因小鼠模型中抑制了LLC肿瘤生长，并降低了肿瘤中的蛋氨酸水平。A1-R-rMETase结合了A1-R的肿瘤靶向和杀伤能力以及靶向癌症蛋氨酸成瘾的rMETase。
