Department of Nuclear Medicine, Lanzhou University Second Hospital, Lanzhou 730030.
Cuiying Biomedical Research Center, Lanzhou University Second Hospital, Lanzhou 730030.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2022 Dec 28;47(12):1629-1636. doi: 10.11817/j.issn.1672-7347.2022.210560.
Fluorouracil chemotherapeutic drugs are the classic treatment drugs of gastric cancer. But the problem of drug resistance severely limits their clinical application. This study aims to investigate whether hypoxia microenvironment affects gastric cancer resistance to 5-fluorouracil (5-FU) and discuss the changes of gene and proteins directly related to drug resistance under hypoxia condition.
Gastric cancer cells were treated with 5-FU in hypoxia/normoxic environment, and were divided into a Normoxic+5-FU group and a Hypoxia+5-FU group. The apoptosis assay was conducted by flow cytometry Annexin V/PI double staining. The real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect the expression level of hypoxia inducible factor-1α (HIF-1α), multidrug resistance (MDR1) gene, P-glycoprotein (P-gp), and vascular endothelial growth factor (VEGF) which were related to 5-FU drug-resistance. We analyzed the effect of hypoxia on the treatment of gastric cancer with 5-FU.
Compared with the Normoxic+5-FU group, the apoptosis of gastric cancer cells treated with 5-FU in the Hypoxia+5-FU group was significantly reduced (P<0.05), and the expression of apoptosis promoter protein caspase 8 was also decreased. Compared with the the Normoxic+5-FU group, HIF-1α mRNA expression in the Hypoxia+5-FU group was significantly increased (P<0.05), and the mRNA and protein expression levels of MDR1, P-gp and VEGF were also significantly increased (all P<0.05). The increased expression of MDR1, P-gp and VEGF had the same trend with the expression of HIF-1α.
Hypoxia is a direct influencing factor in gastric cancer resistance to 5-FU chemotherapy. Improvement of the local hypoxia microenvironment of gastric cancer may be a new idea for overcoming the resistance to 5-FU in gastric cancer.
氟尿嘧啶类化疗药物是胃癌的经典治疗药物。但药物耐药问题严重限制了其临床应用。本研究旨在探讨缺氧微环境是否影响胃癌对 5-氟尿嘧啶（5-FU）的耐药性，并探讨缺氧条件下与耐药性直接相关的基因和蛋白的变化。
在缺氧/常氧环境下用 5-FU 处理胃癌细胞，分为常氧+5-FU 组和缺氧+5-FU 组。用流式细胞术 Annexin V/PI 双染色法进行细胞凋亡检测。实时逆转录-聚合酶链反应（RT-PCR）和 Western blot 法检测与 5-FU 耐药相关的缺氧诱导因子-1α（HIF-1α）、多药耐药（MDR1）基因、P-糖蛋白（P-gp）和血管内皮生长因子（VEGF）的表达水平。分析缺氧对胃癌 5-FU 治疗的影响。
与常氧+5-FU 组相比，缺氧+5-FU 组胃癌细胞经 5-FU 处理后的凋亡明显减少（P<0.05），促凋亡蛋白 caspase 8 的表达也减少。与常氧+5-FU 组相比，缺氧+5-FU 组 HIF-1αmRNA 表达明显增加（P<0.05），MDR1、P-gp 和 VEGF 的 mRNA 和蛋白表达水平也明显增加（均 P<0.05）。MDR1、P-gp 和 VEGF 的表达增加与 HIF-1α的表达趋势相同。
缺氧是胃癌对 5-FU 化疗耐药的直接影响因素。改善胃癌局部缺氧微环境可能是克服胃癌对 5-FU 耐药的新途径。
