目的 探討褪黑素通過抑制溶質運載蛋白7家族成員11（SLC7A11）表達對食管鱗癌細胞鐵死亡的影響。方法 使用不同濃度（0.25、0.5、1.0、2.0、4.0 mmol/L）的褪黑素處理人食管鱗癌KYSE150細胞，篩選建立KYSE150細胞鐵死亡模型的褪黑素濃度；將KYSE150細胞分為對照組、褪黑素（1.0 mmol/L）組、褪黑素（1.0 mmol/L）＋pcDNA（轉染空載質粒）組、褪黑素（1.0 mmol/L）＋SLC7A11（轉染SLC7A11過表達質粒）組。透射電子顯微鏡觀察KYSE150細胞線粒體形態(tài)；碘化丙啶（PI）染色檢測細胞死亡；試劑盒檢測細胞Fe²⁺、谷胱甘肽（GSH）及活性氧（ROS）水平；Western blotting法檢測細胞SLC7A11蛋白表達。建立食管鱗癌裸鼠荷瘤模型，將BALB/c裸鼠分為模型組、褪黑素（ip 25 mg/kg褪黑素）組、褪黑素＋pcDNA（ip 25 mg/kg褪黑素＋裸鼠右側腋下注射轉染空載質粒的KYSE150細胞）組、褪黑素＋SLC7A11（ip 25 mg/kg褪黑素＋裸鼠右側腋下注射轉染SLC7A11過表達質粒的KYSE150細胞）組；分別檢測各組小鼠腫瘤體積、質量及腫瘤組織中SLC7A11蛋白表達。結果 1.0 mmol/L褪黑素可誘導KYSE150細胞鐵死亡；與對照組比較，褪黑素組KYSE150細胞死亡數(shù)目增多，細胞內(nèi)的線粒體變小，線粒體膜密度增加，細胞內(nèi)Fe²⁺及ROS水平顯著增加（P＜0.05），SLC7A11蛋白表達水平及細胞內(nèi)GSH水平顯著降低（P＜0.05）；與褪黑素＋pcDNA組比較，褪黑素＋SLC7A11組細胞死亡數(shù)目減少，細胞內(nèi)的線粒體增大，線粒體膜密度減少，細胞內(nèi)Fe²⁺及ROS水平顯著降低（P＜0.05），SLC7A11蛋白表達水平及細胞內(nèi)GSH水平顯著升高（P＜0.05）；褪黑素可通過抑制SLC7A11蛋白表達抑制食管鱗癌裸鼠腫瘤生長。結論 褪黑素可能通過抑制SLC7A11表達誘導細胞鐵死亡，抑制食管鱗癌細胞生長。

Objective To investigate the effect of melatonin on ferroptosis of esophageal squamous cell carcinoma by inhibiting the expression of solute carrier protein 7 family member 11 (SLC7A11). Methods The KYSE150 cells were treated with different concentrations of melatonin (0.25, 0.5, 1.0, 2.0, 4.0 mmol/L), and the concentrations of melatonin were screened to establish the iron death model of KYSE150 cells. KYSE150 cells were divided into control group, melatonin (1.0 mmol/L) group, melatonin (1.0 mmol/L) + pcDNA (transfected with empty plasmid) group, and melatonin (1.0 mmol/L) + SLC7A11 (transfected with SLC7A11 overexpression plasmid) group. Mitochondrial morphology of KYSE150 cells was observed by transmission electron microscope. The cell death was detected by propyl iodide (PI) staining. The levels of Fe²⁺, glutathione (GSH), and reactive oxygen species (ROS) were detected by the kit. The expression of SLC7A11 protein was detected by Western blotting. Establishing a tumor bearing model of esophageal squamous cell carcinoma in nude mice. BALB/c nude mice were divided into model group, melatonin (ip 25mg/kg melatonin) group, melatonin + pcDNA (ip 25mg/kg melatonin + KYSE150 cells transfected with empty plasmids injected into the right armpit of nude mice) group, and melatonin +SLC7A11 (ip 25mg/kg melatonin + KYSE150 cells transfected with SLC7A11 overexpression plasmid by right armpit injection of nude mice) group. Tumor volume, mass and expression of SLC7A11 protein in tumor tissues were detected. Results 1.0 mmol/L melatonin was able to induce ferroptosis of KYSE150 cells. Compared with control group, the death number of KYSE150 cells in melatonin group increased, intracellular mitochondria became smaller, mitochondrial membrane density increased, intracellular Fe²⁺ and ROS levels were significantly increased (P < 0.05), SLC7A11 protein expression level and intracellular GSH level were significantly decreased (P < 0.05). Compared with melatonin + pcDNA group, the number of cell death in melatonin + SLC7A11 group was decreased, intracellular mitochondria were increased, mitochondrial membrane density was decreased, intracellular Fe²⁺ and ROS levels were significantly decreased (P < 0.05), SLC7A11 protein expression level and intracellular GSH level were significantly increased (P < 0.05). Melatonin can inhibit the tumor growth of nude mice with esophageal squamous cell carcinoma by inhibiting SLC7A11 protein expression. Conclusion Melatonin may induce cell ferroptosis and inhibit the growth of esophageal squamous cell carcinoma by inhibiting the expression of SLC7A11.

河北省衛(wèi)生和計劃生育委員會科研基金項目（20220981）