摘要目的 探讨FAM83A对胰腺癌细胞PANC-1干细胞样表型和放射敏感性的影响,旨在为胰腺癌靶向治疗提供新思路.方法 慢病毒感染构建稳定沉默FAM83A的PANC-1细胞株,qPCR和Western blot进行验证;流式细胞仪检测干细胞标记物CD133阳性的细胞数;肿瘤细胞成球实验检测PANC-1细胞成球能力;MTT检测吉西他滨对PANC-1稳转株细胞活力的影响;平板克隆形成实验检测X射线照射对PANC-1稳转株细胞增殖的影响;流式细胞术检测吉西他滨和X射线照射对PANC-1稳转株细胞凋亡的影响;Western blot检测PANC-1稳转株细胞中Wnt/β-catenin信号通路表达变化.结果 沉默FAM83A后PANC-1细胞中FAM83A蛋白表达(0.83±0.08)和mRNA表达(0.29±0.03)较阴性对照组FAM83A蛋白表达(1.95±0.19)和mRNA表达(0.98±0.09)显著降低(t=9.410、12.600,P<0.05);沉默FAM83A后CD133阳性PANC-1细胞率(8.97±0.62)％ 较阴性对照组(21.60±2.60)％ 显著降低(t=8.184,P<0.05),且细胞成球数(8±1)较阴性对照组(25±3)亦显著降低(t=9.311,P<0.05),PANC-1细胞干细胞样表型显著被抑制;沉默FAM83A联合50μmol/L吉西他滨处理PANC-1细胞72 h后细胞活力(32.33±3.05)％ 较吉西他滨处理组(63.06±5.98)％显著降低,细胞凋亡率(76.52±8.34)％ 较吉西他滨处理组(40.88±4.91)％ 显著增加,差异有统计学意义(t=6.378、7.929,P<0.05);沉默FAM83A联合X射线照射后,PANC-1细胞活力(43.25±4.21)％较X射线照射组(78.13±7.98)％明显降低,细胞凋亡率(44.56±5.32)％ 较X射线照射组(15.15±1.95)％ 明显增加,差异有统计学意义(t=6.694、8.990,P<0.05);沉默FAM83A后细胞中Wnt/β-catenin信号通路蛋白Active-β-catenin表达降低,p-β-catenin表达增加,且细胞核中 β-catenin表达也降低,差异有统计学意义(t=10.290、8.521、8.969,P<0.05),而Totalβ-catenin无明显变化,细胞中Wnt/β-catenin信号通路活性明显被抑制.结论 沉默FAM83A可能通过Wnt/β-catenin信号抑制胰腺癌细胞干细胞样表型,增强细胞对化疗药物吉西他滨及放射敏感性,FAM83A将可为胰腺癌临床治疗提供新靶点.

abstractsObjective To investigate the effect of FAM83A on the stem cell-like phenotype, chemosensitivity and radiosensitivity of PANC-1 cells, aiming to provide new ideas for clinical combination therapy of pancreatic cancer. Methods The PANC-1 cells with stable silencing FAM83A were constructed by using lentivirus and validated by qPCR and Western blot. Flow cytometry was used to detect the number of CD133 positive cells and cellular apoptosis; the sphere formation assay was used to test the ability of sphere formation of PANC-1 cells;the effect of gecitabine on the cell viability was detected by MTT assay;the effect of radiation on the proliferation of PANC-1 cells was detected by colony formation assay; the effect of FAM83A on Wnt/β-catenin pathway was examined by Western blot. Results The expressions of FAM83A protein ( 0.83 ± 0.08 ) and mRNA ( 0.29 ± 0.03 ) in PANC-1 cells with stable silencing FAM83A were significantly lower than those in the scrambled control group, respectively (1.95 ± 0.19, 0.98 ± 0.09;t=9.410, 12.600, P<0.05). After silencing FAM83A, the expression of stem cell marker CD133 (8.97 ± 0.62) and the sphere formation ability (8 ± 1) also decreased significantly compared with the scrambled group, respectively (21.60 ± 2.60, 25 ± 3; t=8.184, 9.311, P<0.05), and the stem cell-like phenotype of PANC-1 cells was also significantly inhibited. When PANC-1 cells were silenced by FAM83A and further treated with 50 μmol/L gecitabine at 72 h, the activity of FAM83A-silenced PANC-1 cells (32.33 ± 3.05)％ was significantly lower than that of the gecitabine alone treated group (63.06 ± 5.98)％ (t=6.378, P<0.05), and the apoptosis rate of FAM83A-silenced PANC-1 cells (76.52 ± 8.34) ％ was significantly higher than that of gemcitabine alone group (40.88 ± 4.91)％(t=7.929, P<0.05). After silencing FAM83A combined with IR irradiation, the activity of PANC-1 cells (43.25 ±4.21)％ was significantly lower than that of IR alone (78.13 ± 7.98)％ (t=6.694, P<0.05), and the apoptosis rate (44.56 ± 5.32)％ was significantly increased compared with IR alone (15.15 ±1.95)％ (t = 8.990, P < 0.05). After silencing FAM83A, the expression of Active-β-catenin was significantly decreased while the expression of p-β-catenin was significantly increased, the expression of β-catenin in the nucleus was significantly reduced, although total β-catenin had no significant change, and the activity of Wnt/β-catenin signaling pathway was significantly inhibited. Conclusions Silencing FAM83A could significantly reduce the stem cell-like traits and enhance the chemosensitivity and radiosensitivity of pancreatic cancer cells to gemcitabine and radiation via Wnt/β-catenin signaling pathway, which may provide a new target for targeted and combination therapy of pancreatic cancer.