Song Yan, Zhou Xinjia, Bai Weiliang, Ma Xiulan
Department of Otorhinolaryngology, Sheng Jing Hospital, China Medical University, Shenyang, 110004, China.
Tumour Biol. 2015 Jun;36(6):4197-202. doi: 10.1007/s13277-015-3056-4. Epub 2015 Jan 14.
F-box/WD repeat-containing protein 7 (FBW7) is a member of the F-box protein family that regulates cell cycle progression and cell growth and differentiation. FBW7 also functions as a tumor suppressor. A cisplatin (CDDP)-based multidrug chemotherapy regimen is standard for nasopharyngeal carcinoma (NPC), but drug resistance is an increasing problem. Here, we evaluated the relationship between FBW7 and multidrug resistance-associated protein (MRP), and its correlation with drug resistance in NPC, and explored the mechanism underlying drug resistance to CDDP in this disease. We used cell viability assays, Western blotting, and small interfering RNA (siRNA) interference to investigate the underlying mechanism underlying CDDP resistance in a NPC cell line. The expression of FBW7 and MRP was detected by Western blotting after siRNA interference in the CDDP-resistant NPC cell line, CNE2-CDDP. The 3-(4 5-dimethyl-2-thiazolyl)-2 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to evaluate drug sensitivity of various types of antitumor drugs, including paclitaxel (PCX), CDDP, fluorouracil (5-FU), and vincristine (VCR). We found that siRNA-mediated upregulation of FBW7 significantly increased CDDP chemosensitivity. The IC50 values of CDDP in siRNA-FBW7-CNE2-CDDP and FBW7-CNE2-CDDP-NC cells were 2.485 ± 0.155 and 4.867 ± 0.442 μmol/mL, respectively. The IC50 values of PCX, CDDP, 5-FU, and VCR were significantly decreased in siRNA-FBW7-CNE2 than in FBW7-CNE2-NC (3.46 ± 0.14 vs. 46.21 ± 6.03 μmol/mL; 3.76 ± 0.54 vs. 39.45 ± 0.96 μmol/mL; 2.14 ± 1.67 vs. 28.76 ± 1.89 μmol/mL; 4.43 ± 0.89 vs. 87.90 ± 3.45 μmol/mL, respectively). The IC50 of CDDP was significantly less in siRNA-FBW7-CNE2-CDDP than in FBW7-CNE2-CDDP-NC. The level of FBW7 expression in CNE2 cells was correlated with CDDP chemosensitivity. siRNA-mediated upregulation of FBW7 expression downregulated the expression of MRP, significantly increasing drug sensitivity in CNE2 cells.
含F-box/WD重复序列蛋白7（FBW7）是F-box蛋白家族的成员，该家族可调节细胞周期进程以及细胞生长和分化。FBW7还具有肿瘤抑制功能。基于顺铂（CDDP）的多药化疗方案是鼻咽癌（NPC）的标准治疗方案，但耐药性问题日益突出。在此，我们评估了FBW7与多药耐药相关蛋白（MRP）之间的关系及其与NPC耐药性的相关性，并探讨了该疾病对CDDP耐药的潜在机制。我们使用细胞活力测定、蛋白质免疫印迹法和小干扰RNA（siRNA）干扰来研究NPC细胞系中CDDP耐药的潜在机制。在对CDDP耐药的NPC细胞系CNE2-CDDP中进行siRNA干扰后，通过蛋白质免疫印迹法检测FBW7和MRP的表达。采用3-（4,5-二甲基-2-噻唑基）-2,5-二苯基-2-H-四氮唑溴盐（MTT）法评估包括紫杉醇（PCX）、CDDP、氟尿嘧啶（5-FU）和长春新碱（VCR）在内的各种抗肿瘤药物的药敏性。我们发现，siRNA介导的FBW7上调显著增加了CDDP的化疗敏感性。在siRNA-FBW7-CNE2-CDDP和FBW7-CNE2-CDDP-NC细胞中，CDDP的半数抑制浓度（IC50）值分别为2.485±0.155和4.867±0.442μmol/mL。与FBW7-CNE2-NC相比，siRNA-FBW7-CNE2中PCX、CDDP、5-FU和VCR的IC50值显著降低（分别为3.46±0.14 vs. 46.21±6.03μmol/mL；3.76±0.54 vs. 39.45±0.96μmol/mL；2.14±1.67 vs. 28.76±1.89μmol/mL；4.43±0.89 vs. 87.90±3.45μmol/mL）。在siRNA-FBW7-CNE2-CDDP中，CDDP的IC50显著低于FBW7-CNE2-CDDP-NC。CNE2细胞中FBW7的表达水平与CDDP化疗敏感性相关。siRNA介导的FBW7表达上调下调了MRP的表达，显著增加了CNE2细胞的药敏性。
