Abstract：
Camptothecin (CPT), a naturally occurring alkaloid derived from the Camptotheca acuminate plant, exerts anti-tumor properties. However, its specific impact on head and neck squamous cell carcinoma (HNSCC) remains uncertain. The study was to explore the action and mechanism of CPT on HNSCC cells. First, two HNSCC cell lines (FaDu and TU686) and a normal immortalized keratinocyte (HEK001) cell line, were exposed to a spectrum of CPT concentrations (ranging from 10 to 50 μM) for durations of 24 h and 48 h. Cell viability, proliferation, migration, and invasion were assessed by CCK-8 assay, EdU incorporation assay, wound healing assay and transwell assay. Subsequently, si-RAB27A or negative control (NC) was introduced into FaDu and TU686 cells through transfection, and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was manipulated with L740Y-P, an activator of this pathway. The expression of proliferating cell nuclear antigen (PCNA), E-cadherin, PI3K/AKT signaling factors and RAB27A were determined by Western blot analysis. RAB27A was detected by immunofluorescence assay. It was found that CPT significantly hindered the viability, proliferation (p<0.01), migration (p<0.001), and invasion (p<0.001) of FaDu and TU686 cells. At the molecular level, administration of CPT caused a decline in the expression of PCNA, P-PI3K, P-AKT, and RAB27A, alongside an elevation in E-cadherin levels within HNSCC cells (p<0.05, p<0.01 and p<0.001). Reducing RAB27A expression enhanced the suppressive impacts of CPT on HNSCC cell viability (p<0.05 and p<0.01), migration (p<0.001) and invasion (p<0.01), these effects that were reversed upon treatment with L740Y-P in HNSCC cells (p<0.001). In summary, our study highlights the efficacy of CPT in HNSCC, demonstrating its influence on cell processes via the RAB27A-mediated PI3K/AKT pathway.
摘要：
喜树碱(CPT),一种来自喜树植物的天然生物碱，发挥抗肿瘤特性。然而,其对头颈部鳞状细胞癌（HNSCC）的具体影响仍不确定。本研究旨在探讨CPT对HNSCC细胞的作用及其机制。首先,两个HNSCC细胞系（FaDu和TU686）和一个正常的永生化角质形成细胞（HEK001）细胞系，暴露于CPT浓度的光谱(范围从10到50μM)持续24小时和48小时。扩散,迁移,和侵袭通过CCK-8测定进行评估，EdU掺入测定，伤口愈合试验和transwell试验。随后，通过转染将si-RAB27A或阴性对照（NC）引入FaDu和TU686细胞中，用L740Y-P操纵磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)信号通路,该途径的激活剂。增殖细胞核抗原（PCNA）的表达，E-cadherin,通过蛋白质印迹分析测定PI3K/AKT信号传导因子和RAB27A。免疫荧光法检测RAB27A。结果发现，CPT显著阻碍了生存能力，增殖（p<0.01），迁移(p<0.001)，FaDu和TU686细胞的侵袭(p<0.001)。在分子水平上,CPT的给药导致PCNA表达下降，P-PI3K,P-AKT,还有RAB27A,伴随着HNSCC细胞内E-cadherin水平的升高(p<0.05,p<0.01和p<0.001)。降低RAB27A表达增强了CPT对HNSCC细胞活力的抑制作用（p<0.05和p<0.01），迁移(p<0.001)和侵袭(p<0.01)，这些效应在HNSCC细胞中用L740Y-P处理后被逆转(p<0.001)。总之,我们的研究强调了CPT在HNSCC中的疗效，证明其通过RAB27A介导的PI3K/AKT途径对细胞过程的影响。
