藻蓝蛋白亚基脂质体光动力作用对LKB1在乳腺癌细胞中表达的影响

Expression of LKB1 in Breast Cancer Cell with Photodynamic Treatment of Phycocyanin Subunit Liposome

为了探讨肿瘤抑制因子LKB1蛋白在肿瘤光动力疗法中作用,先用MTT法检测藻蓝蛋白亚基脂质体(PEG-PCS-Lip)对人乳腺癌细胞MCF-7,鼠乳腺癌细胞MA-782的光动力杀伤效果,分光光度法检测活性氧ROS的产量,Western blot检测LKB1激酶表达水平;然后用免疫组织化学方法观察PEG-PCS-Lip介导的光动力作用在乳腺癌模型鼠对LKB1基因表达影响。结果显示在光照剂量为29.17 J/cm^22时,用0～25μg/mL PEG-PCS-Lip处理会小幅度促进MA-782和MCF-7细胞的生长,同时细胞中的ROS和LKB1蛋白的量下降;当用25～100μg/mL PEG-PCS-Lip处理则明显抑制MA-782和MCF-7细胞的生长,同时细胞中的ROS和LKB1蛋白的量随PEG-PCS-Lip量的增加而增加。用10 mg/kg PEG-PCS-Lip静脉注射荷瘤小鼠,光照剂量为208.2 J/cm^2时,其抑瘤率可达到68.9%,LKB1在乳腺癌组织中的表达量则增加了33.9%,同时,LKB1激酶从细胞核转移到细胞质的量也在增加。因此,PEG-PCS-Lip PDT作用所产生的ROS可能是激活LKB1的表达的原因之一,二者协同作用在一定的光敏剂浓度范围内增强了PDT抑制肿瘤生长的疗效。

In order to study the tumor suppressor LKB1 effect in photodynamic treated cancer cell with PEG-phycoeyanin subunit liposome （PEG-PCS-Lip） , the cell survival ratio was assessed with MTT method. ROS production and LKB1 expression was detected with ROS kit and western blot in breast cancer MA-782 and MCF-7 after PEG-PCS-Lip PDT（photodynamic therapy） treatment; Then MA-782 was used to establish a breast cancer mouse model . Immunohis- tochemical method was used to observe LKB1 expression in PEG-PCS-Lip PDT treated tumor bearing mouse. The cell experiment indicated that treated the survival ratio of MA-782 and MCF-7 increased in low level, meanwhile the production of ROS and the expression of LKB1 reduced, with the irradiation dose of 29.17 J/cm2 and low PEG-PCS-Lip concentration level （0 -25 μg/mL）. When the scale of PEG-PCS-Lip concentration was from 25 μg/mL to 100 μg/mL, the survival ratio of MA-782 and MCF-7 reduced, meanwhile the production of ROS and the expression of LKB1 increased. In vivo experiment, after injection of 10 mg/kg PEG-PCS-Lip in breast tumor bearing mouse, the tumor inhibition ratio was performed 68.9 % with the irradiation dose of 208.2 J/cm2 , while LKB1 expression increased by 33.9 % and LKB1 translated from nuclei to plasma. Therefore, the production of ROS, induced by PEG-PCS-Lip PDT treatment, maybe one of reason to promote the expression of LKBI , and the upregulation of ROS and LKB1 attribute to PEG-PCS- Lip PDT effect against breast cancer cell.