CAJ | 학술논문

EB病毒编码的瘤蛋白潜伏膜蛋白(LMP1)所介导的活化蛋白(AP-1)信号转导途径在细胞增殖、分化、转化与凋亡方面发挥着重要作用.越来越多的证据表明,AP-1信号转导通路中上游激酶JNK在鼻咽癌的发生发展过程中起着重要作用.最近克隆出来的JNK相互作用蛋白(JIP-1)是一种能抑制JNK核移位的胞浆锚蛋白.为探讨JIP在LMP1调控AP-1信号通路中的作用机制,采用间接免疫荧光法和报告基因法,发现JIP通过有效地抑制磷酸化的JNK从胞浆移位入核,从而抑制LMP1上调的AP-1活性.同时,JIP导入鼻咽癌细胞中,MTT法发现JIP能够明显抑制鼻咽癌细胞的生长.进一步发现转染JIP后细胞的集落形成率与对照组相比大约降低了53.6%,也抑制了细胞. 提示JIP可明显抑制细胞的增殖作用.进一步采用流式细胞术分析,结果发现JIP引起细胞G1/S期细胞阻滞,说明JIP是抑制细胞增殖的重要调节子.进一步采用流式细胞术定量发现,转染JIP后细胞的24 h凋亡百分率由1.25%上升到8.25%,上升约6.6倍,48 h由1.04%上升到31.45%,上升约30倍. 采用激光共聚焦显微镜发现,转染JIP后细胞核发生显著变化,核质由均匀状态固缩成高凝集状态,形成了典型的胞膜体.提示JIP可有效地促进细胞凋亡.结果表明,JIP可通过抑制活化的JNK核移位,降低LMP1所介导的AP-1信号通路.并进一步发现JIP可有效地抑制细胞增殖和细胞凋亡,从而提示JIP可作为新的治疗肿瘤潜在靶分子.
EB병독편마적류단백잠복막단백(LMP1)소개도적활화단백(AP-1)신호전도도경재세포증식、분화、전화여조망방면발휘착중요작용.월래월다적증거표명,AP-1신호전도통로중상유격매JNK재비인암적발생발전과정중기착중요작용.최근극륭출래적JNK상호작용단백(JIP-1)시일충능억제JNK핵이위적포장묘단백.위탐토JIP재LMP1조공AP-1신호통로중적작용궤제,채용간접면역형광법화보고기인법,발현JIP통과유효지억제린산화적JNK종포장이위입핵,종이억제LMP1상조적AP-1활성.동시,JIP도입비인암세포중,MTT법발현JIP능구명현억제비인암세포적생장.진일보발현전염JIP후세포적집락형성솔여대조조상비대약강저료53.6%,야억제료세포. 제시JIP가명현억제세포적증식작용.진일보채용류식세포술분석,결과발현JIP인기세포G1/S기세포조체,설명JIP시억제세포증식적중요조절자.진일보채용류식세포술정량발현,전염JIP후세포적24 h조망백분솔유1.25%상승도8.25%,상승약6.6배,48 h유1.04%상승도31.45%,상승약30배. 채용격광공취초현미경발현,전염JIP후세포핵발생현저변화,핵질유균균상태고축성고응집상태,형성료전형적포막체.제시JIP가유효지촉진세포조망.결과표명,JIP가통과억제활화적JNK핵이위,강저LMP1소개도적AP-1신호통로.병진일보발현JIP가유효지억제세포증식화세포조망,종이제시JIP가작위신적치료종류잠재파분자.
Activator protein 1 (AP-1) is known to be constitutively activated by the Epstein-Barr latent membrane protein 1 in nasopharyngeal carcinoma cells. Increasing evidence indicated that C-jun N-terminal kinase (JNK), the key upstream kinase of AP-1 mediated signal transduction pathway, plays a key role in the carcinogenesis and progression of nasopharyngeal carcinoma. JNK interacting protein 1 (JIP-1) was newly identified as a potent inhibitor of JNK. The effect of JIP on the proliferation of nasopharyngeal carcinoma cells through interaction with the AP-1 signaling pathway was detected using immunofluroscence, reporter gene, MTT, colony formation and flow cytometric analysis. In nasopharyngeal carcinoma cells, data suggested that JIP down-regulated AP-1 activity through the inhibition of the translocation of phospho-JNK from the cytoplasm to the nucleus. Furthermore, JIP inhibited the rates of cell survival and colony formation. The number of cells in S phase decreased and the number of cells in G1/G0 phase increased after the flow cytometric analysis, suggesting that JIP induced growth arrest of Tet-on-LMP1-HNE2 cells in G1/S phase of the cell cycle. The results, therefore, demonstrated that JIP, by inhibiting AP-1-mediated signal transduction pathway, interfered the cell cycle and may act as an important negative regulator of the proliferation of nasopharyngeal carcinoma cells. Also, it was detected by flow cytometry analysis and laser scanning confocal microscope that JIP triggered the apoptosis of NPC cells. In conclusion, JIP represents a promising new therapeutic molecule for nasopharyngeal carcinoma.