探讨缺氧环境下肥胖相关蛋白（FTO）表达对胶质母细胞瘤（GBM）增殖的作用及机制。

（1）收集2021年1月至2024年12月于新疆医科大学第二附属医院神经外科接受手术切除的15例GBM患者的肿瘤组织样本，从外周区、中间区及核心区分别取材，每个区域获肿瘤组织样本15份。采用Western blot及qRT-PCR分析GBM样本中不同区域FTO转录及翻译情况；利用GEO数据库（GSE78025）及细胞模型，将U251-MG和LN229细胞分为常氧、中度缺氧（1%O₂）、重度缺氧（5%O₂），分析不同条件下FTO表达差异。（2）选取24只4周龄Balb/c裸鼠，将预先稳定感染Lv-FTO或Lv-NC的U251-MG和LN229细胞分别接种于小鼠皮下，构建异种移植瘤模型，每种细胞系按照随机数字表法分为FTO过表达组（Lv-FTO组）与阴性对照组（Lv-NC），每组6只。观察并比较2组小鼠移植瘤体积和质量的变化，探讨FTO过表达对GBM细胞增殖的影响，并检测移植瘤组织中PCNA、Vimentin和Twist的表达情况。（3）在缺氧条件下检测GBM细胞中miR-27a-3p表达情况，并通过转染agomir-27a-3p/antagomir-27a-3p完成过表达或抑制，设置agomir-NC组、agomir-27a-3p组、antagomir-NC组及antagomir-27a-3p组，采用qRT-PCR和Western blot检测其对FTO mRNA及蛋白表达的影响。

（1）FTO在GBM组织中呈区域性差异表达，核心区与中间区FTO mRNA及蛋白表达水平均低于外周区，差异均有统计学意义（P<0.05）；与常氧条件相比，缺氧环境下GBM细胞中FTO的表达显著下调，差异有统计学意义（P<0.05）。（2）与Lv-NC组相比，Lv-FTO组小鼠移植瘤的体积更小、质量更轻，差异均有统计学意义（P<0.05）；且Lv-FTO组移植瘤组织中PCNA、Vimentin和Twist的蛋白及mRNA表达水平均显著低于Lv-NC组，差异均有统计学意义（P<0.05）。（3）与常氧条件相比，重度缺氧条件下miR-27a-3p表达显著上调（P<0.05）；与agomir-NC组相比，agomir-27a-3p组FTO mRNA及蛋白表达显著降低，差异均有统计学意义（P<0.05）；与antagomir-NC组相比，antagomir-27a-3p组FTO表达显著升高，差异有统计学意义（P<0.05）。

FTO可通过下调PCNA、Vimentin和Twist的表达抑制GBM细胞增殖，缺氧环境下FTO表达降低，降低了对GBM增殖的抑制作用；而miR-27a-3p可负向调控FTO表达，间接促进GBM增殖。

To investigate the effect and fat mass and obesity-associated protein (FTO) expression on tumor proliferation in glioblastoma (GBM) under hypoxic environment.

(1) Tumor tissue samples were collected from 15 GBM patients who underwent surgical resection at the Second Affiliated Hospital of Xinjiang Medical University from January 2021 to December 2024. Samples were collected from the peripheral, intermediate, and core regions, with 15 tumor tissue samples obtained from each region. Analyze the transcription and translation of FTO in different regions of GBM samples through Western blot and qRT-PCR; Using the GEO database (GSE78025) and cell models, U251-MG and LN229 cells were divided into normoxic, moderate hypoxic (1%O₂), and severe hypoxic (5%O₂) groups, and the differences in FTO expression under different conditions were analyzed. (2) Twenty-four 4-week-old Balb/c nude mice were selected, and U251-MG and LN229 cells pre stably infected with Lv-FTO or Lv-NC were subcutaneously inoculated into mice to construct xenograft tumor models. Each cell line was randomly divided into an FTO overexpression group (Lv-FTO group) and a negative control group (Lv-NC) using a random number table method, with 6 mice in each group. The changes in volume and mass of transplanted tumors in two groups of mice were observed and compared. The effect of FTO overexpression on GBM cell proliferation was explored, and the expression of PCNA, Vimentin, and Twist in transplanted tumor tissues was detected. (3) The expression changes of miR-27a-3p in GBM cells were detected under hypoxic conditions. Overexpression or inhibition of miR-27a-3p was achieved by transfecting agomir-27a-3p/antagomir-27a-3p, agomir-NC group, agomir-27a-3p group, antagomir-NC group, and antagomir-27a-3p group were set up, and its effects on FTO mRNA and protein expression were detected by qRT-PCR and Western blot.

(1) FTO exhibited regional expression differences in GBM tissue, with FTO mRNA and protein expression levels in the core and intermediate zones significantly lower than those in the peripheral zone (P<0.05); Compared with normoxic conditions, FTO expression in GBM cells was significantly downregulated under hypoxic conditions (P<0.05). (2) Compared with the Lv-NC control group, the Lv-FTO overexpression group in nude mice exhibited significantly smaller tumor volumes and lighter tumor weights (P<0.05). furthermore, the protein and mRNA expression levels of PCNA, Vimentin, and Twist in tumor tissues of the Lv-FTO group were all significantly lower than those in the Lv-NC group (P<0.05). (3) Compared with the normoxic group, miR-27a-3p expression was significantly upregulated in the hypoxic group (P<0.05); Compared with the agomir-NC group, FTO mRNA and protein expression were significantly reduced in the agomir-27a-3p group (P<0.05); Compared with the antagomir-NC group, FTO expression was significantly increased in the antagomir-27a-3p group (P<0.05).

FTO inhibits GBM cell proliferation by downregulating the expression of PCNA, Vimentin, and Twist; Under hypoxic conditions, FTO expression decreases, reducing its inhibitory effect on GBM proliferation; MiR-27a-3p negatively regulates FTO expression, indirectly promoting GBM proliferation.