OBJECTIVE: To explore the neuroprotective effect and underlying mechanism of Xingnao Kaiqiao acupuncture (acupuncture for regaining consciousness and opening orifices) in the rat models of cerebral ischemia-reperfusion injury (CIRI) based on the p53 protein (p53)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway. METHODS: Of 102 male Wistar rats, 20 rats were randomly collected as a sham-operation group. Using a modified external carotid artery filament insertion method, CIRI models were prepared by occluding the middle cerebral artery in the rest rats. After modeling and excluding 1 non-successfully modeled rat and 1 dead one, the other modeled rats were randomized into a model group, an agonist group, an acupuncture group, and an acupuncture + agonist group, 20 rats in each one. Xingnao Kaiqiao acupuncture therapy was delivered in the rats of the acupuncture group and the acupuncture + agonist group. The acupoints included "Shuigou" (GV26), bilateral "Neiguan" (PC6), and "Sanyinjiao" (SP6) on the affected side. Electroacupuncture was attached to "Neiguan" (PC6) and "Sanyinjiao" (SP6) on the affected side, with dense-disperse wave, a frequency of 2 Hz/15 Hz and intensity of 1 mA. The intervention was delivered twice daily, 20 min each time and for 7 consecutive days. In the agonist group and acupuncture+agonist group, p53 agonist, COTI-2 was intraperitoneally injected (15 mg/kg), once daily for 7 consecutive days. Neurological deficit was evaluated using Zausinger's six-point scale. Cerebral infarction volume was quantified by triphenyl tetrazolium chloride (TTC) staining. Histopathological changes were observed using hematoxylin-eosin (HE) staining. Iron deposition was assessed by Prussian blue staining. Mitochondrial ultrastructure in the ischemic cortex was examined under transmission electron microscopy (TEM). Serum iron (Fe²⁺) was measured with chromometry. Malondialdehyde (MDA) and glutathione (GSH) levels in the ischemic hippocampus were determined using thiobarbituric acid and microplate assays, respectively. The mean fluorescence intensity of reactive oxygen species (ROS) in the ischemic cortex was analyzed by flow cytometry. The mRNA and protein expression of GPX4, SLC7A11, and p53 in the ischemic hippocampus were evaluated using quantitative real-time PCR (qRT-PCR) and Western blotting, respectively. RESULTS: Compared with the sham-operated group, the model group exhibited the decrease in neurological deficit score (P<0.01), and the increase in cerebral infarction volume percentage (P<0.01). The changes of brain tissue were presented in extensive cellular necrosis, pyknotic and deeply-stained nuclei, and vacuolar degeneration. The iron deposition was elevated in cortex and hippocampus (P<0.01), mitochondrial membrane density increased, the cristae was broken or reduced, and the outer membrane ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were elevated (P<0.01) and the level of GSH was reduced (P<0.01). The mRNA and protein expression of GPX4 and SLC7A11 was reduced (P<0.01), while that of p53 rose (P<0.01). When compared with the model group, in the agonist group, the neurological deficit score was reduced (P<0.05), the percentage of infarction volume was higher (P<0.01), the histopathological damage was further exacerbated, and the percentage of iron deposition increased in the cortex and hippocampus (P<0.01). The mitochondrial quantity decreased, the membrane density increased, the mitochondrial cristae were broken or reduced, and the outer membrane was ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were higher (P<0.01, P<0.05) and the level of GSH was reduced (P<0.05). The mRNA and protein expression of GPX4 and SLC7A11 decreased (P<0.01, P<0.05), while that of p53 was elevated (P<0.01). Besides, in comparison with the model group, the neurological deficit score was higher in the acupuncture group and the acupuncture + agonist group (P<0.01, P<0.05), the percentage of cerebral infarction volume was lower in the acupuncture group (P<0.01), the pathological damage of brain tissue was alleviated in the acupuncture group and the acupuncture + agonist group, and the percentage of iron depositiondecreased in the cortex and hippocampus (P<0.01). The mitochondrial structure was relatively clear, the mitochondrial cristae were fractured or reduced mildly in the acupuncture group and the acupuncture + agonist group. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were lower (P<0.01) and the level of GSH was higher (P<0.01) in the acupuncture group. The mean fluorescence intensity of ROS were dropped (P<0.01) in the acupuncture + agonist group. The mRNA expression of GPX4 and SLC7A11 was elevated (P<0.01) and that of p53 was reduced (P<0.01, P<0.05) in either the acupuncture group or the acupuncture + agonist group; the protein expression of GPX4 and SLC7A11 rose (P<0.05, P<0.01) and that of p53 was dropped (P<0.01) in the acupuncture group; and the protein expression of p53 was also lower in the acupuncture + agonist group (P<0.05). When compared with the agonist group, in the acupuncture + agonist group, neurological deficit score increased (P<0.01), the percentage of cerebral infarction volume decreased (P<0.01), the pathological brain tissue damage was reduced, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was relatively clear and the cristae broken or reduced slightly; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were dropped (P<0.01), while the level of GSH increased (P<0.05); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01). In comparison with the acupuncture + agonist group, in the acupuncture group, the neurological deficit score increased (P<0.05), the percentage of cerebral infarction volume decreased (P<0.05), the pathological brain tissue damage was alleviated, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was normal in tendency; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were reduced (P<0.05), while the level of GSH rose (P<0.01); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01, P<0.05). CONCLUSION Xingnao Kaiqiao acupuncture can alleviate neurological damage in CIRI rats, which is obtained probably by inhibiting ferroptosis through p53/SLC7A11/GPX4 pathway.
Animals ; Reperfusion Injury/metabolism* ; Male ; Acupuncture Therapy ; Rats ; Tumor Suppressor Protein p53/genetics* ; Brain Ischemia/metabolism* ; Rats, Wistar ; Signal Transduction ; Humans ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Disease Models, Animal ; Acupuncture Points ; Amino Acid Transport System y+/genetics*

OBJECTIVE: To observe the effects of Tongdu Tiaoshen acupuncture (acupuncture for unblocking the obstruction in the governor vessel and regulating the spirit) on the depression-like behavior and the hippocampal neuronal ferroptosis mediated by solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) pathway in depression rats, and explore the mechanism of this therapy for depression. METHODS: Of 30 male SD rats of SPF grade, 24 rats were selected. According to the random number table, they were divided into a normal group (n=8) and a modeling group (n=16). The rats in the modeling group were subjected to chronic unpredictable mild stress (CUMS) for 28 consecutive days to establish depression model. After modeling, 16 successfully-modeled rats were randomly divided into a model group and an acupuncture group, 8 rats in each one. In the acupuncture group, Tongdu Tiaoshen acupuncture was applied to "Dazhui"(GV14), "Shuigou" (GV26), "Baihui" (GV20) and "Shenting" (GV24). This intervention measure was deliveredonce a day, continuously for 6 days. The intervention discontinued on day 7, and was completed in 4 weeks. Before and after modeling, and after intervention completion, the behavioristics detection was performed using sucrose preference experiment and open field experiment. After intervention, using hematoxylin-eosin (HE) and Nissl staining, the morphology of hippocampal neurons was observed; with Western blot method, the protein expression of GPX4, SLC7A11, Ferritin and acyl-CoA synthetase long-chain family 4 (ACSL4) in hippocampal tissues was detected; with the real-time fluorescence quantitative PCR adopted, the mRNA expression of GPX4, SLC7A11, Ferritin and ACSL4 was detected; and using colorimetry, the hippocampal iron content was determined. RESULTS: After modeling, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the model group and the acupuncture group were lower than those in the normal group (P<0.01). After the intervention, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the acupuncture group were higher than those in the model group (P<0.01, P<0.05). Compared with the normal group, the number of necrotic cells increased and the number of Nissl bodies decreased in the model group; and when compared with the model group, the neuronal pyknosis and necrosis were ameliorated, the cells were arranged more regularly, the neuronal structure was clear, the matrix was dense, the blood vessels were enriched and the number of Nissl bodies increased in the acupuncture group. In comparison with the normal group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 decreased (P<0.01), it increased in the expression of hippocampal Ferritin and ACSL4 (P<0.01) in the model group. When compared with the model group, in the acupuncture group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 was elevated (P<0.01, P<0.05), it was dropped for hippocampal Ferritin and ACSL4 (P<0.01). In the model group, the hippocampal iron content was elevated when compared with that in the normal group (P<0.01); and it was reduced in the acupuncture group when compared with that in the model group (P<0.05). CONCLUSION Tongdu Tiaoshen acupuncture attenuates depression-like behaviors in the depression rats, which may be related to regulating SLC7A11/GPX4 pathway and inhibiting neuronal ferroptosis in the hippocampus.
Animals ; Ferroptosis ; Male ; Hippocampus/cytology* ; Rats, Sprague-Dawley ; Rats ; Depression/enzymology* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Acupuncture Therapy ; Neurons/metabolism* ; Humans ; Acupuncture Points ; Amino Acid Transport System y+/genetics* ; Glutathione Peroxidase/genetics*

Esculetin, a natural dihydroxy coumarin derived from the Chinese herbal medicine Cortex Fraxini, has demonstrated significant pharmacological activities, including anticancer properties. Ferroptosis, an iron-dependent form of regulated cell death, has garnered considerable attention due to its lethal effect on tumor cells. However, the exact role of ferroptosis in esculetin-mediated anti-hepatocellular carcinoma (HCC) effects remains poorly understood. This study investigated the impact of esculetin on HCC cells both in vitro and in vivo. The findings indicate that esculetin effectively inhibited the growth of HCC cells. Importantly, esculetin promoted the accumulation of intracellular Fe²⁺, leading to an increase in ROS production through the Fenton reaction. This event subsequently induced lipid peroxidation (LPO) and triggered ferroptosis within the HCC cells. The occurrence of ferroptosis was confirmed by the elevation of malondialdehyde (MDA) levels, the depletion of glutathione peroxidase (GSH-Px) activity, and the disruption of mitochondrial morphology. Notably, the inhibitor of ferroptosis, ferrostatin-1 (Fer-1), attenuated the anti-tumor effect of esculetin in HCC cells. Furthermore, the findings revealed that esculetin inhibited the Nrf2-xCT/GPx4 axis signaling in HCC cells. Overexpression of Nrf2 upregulated the expression of downstream SLC7A11 and GPX4, consequently alleviating esculetin-induced ferroptosis. In conclusion, this study suggests that esculetin exerts an anti-HCC effect by inhibiting the activity of the Nrf2-xCT/GPx4 axis, thereby triggering ferroptosis in HCC cells. These findings may contribute to the potential clinical use of esculetin as a candidate for HCC treatment.
Umbelliferones/administration & dosage* ; Ferroptosis/drug effects* ; Carcinoma, Hepatocellular/physiopathology* ; NF-E2-Related Factor 2/genetics* ; Humans ; Liver Neoplasms/physiopathology* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Animals ; Cell Line, Tumor ; Mice ; Amino Acid Transport System y+/genetics* ; Mice, Inbred BALB C ; Male ; Signal Transduction/drug effects* ; Lipid Peroxidation/drug effects* ; Reactive Oxygen Species/metabolism* ; Mice, Nude

This study primarily investigated the mechanism of Astragalus polysaccharides(APS), a Chinese medicinal material, in regulating the Nrf2/SLC7A11/GPX4 signaling pathway to induce ferroptosis in ovarian cancer cells(Caov-3 and SKOV3 cells). Caov-3 and SKOV3 cells were divided into control(Vehicle) group, APS group, glutathione peroxidase 4 inhibitor(RSL3) group, and APS+RSL3 group. After 48 h of intervention, the activity and morphology of the cells in each group were observed. The cell counting kit-8(CCK-8) method was used to determine the half-maximal inhibitory concentration(IC_(50)), while colony formation and EdU assays were conducted to assess cell proliferation. Biochemical reagents were used to detect lipid reactive oxygen species(L-ROS), malondialdehyde(MDA), divalent iron ions(Fe~(2+)), and glutathione(GSH) in Caov-3 cells. Transmission electron microscopy was employed to observe the morphological changes of mitochondria in Caov-3 cells. Bioinformatics analysis were used to screen potential target genes of APS in ovarian cancer cells. Western blot and RT-PCR were applied to measure the protein and mRNA expression of Nrf2, SLC7A11, and GPX4. The results revealed that APS effectively inhibited the activity and proliferation of ovarian cancer cells, significantly increased the expression levels of L-ROS, MDA, and Fe~(2+)(P<0.001), and significantly reduced the expression level of GSH(P<0.001). Under electron microscopy, the mitochondria of Caov-3 cells appeared significantly smaller, with a marked increase in the density of the bilayer membrane, disappearance of mitochondrial cristae, and rupture of the outer mitochondrial membrane. These effects were more pronounced when APS was combined with RSL3. Bioinformatics screening identified Nrf2, SLC7A11, and GPX4 as potential target genes for APS in ovarian cancer cells. APS was shown to reduce the protein and mRNA expression of Nrf2, SLC7A11, and GPX4(P<0.01), with the APS+RSL3 showing even more significant effects(P<0.001). In conclusion, APS can induce ferroptosis in ovarian cancer cells, and its mechanism may be related to the regulation of the Nrf2/SLC7A11/GPX4 signaling pathway, providing an experimental basis for the use of APS injections in the treatment of ovarian cancer.
Humans ; Ferroptosis/drug effects* ; Female ; NF-E2-Related Factor 2/genetics* ; Ovarian Neoplasms/physiopathology* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Signal Transduction/drug effects* ; Cell Line, Tumor ; Amino Acid Transport System y+/genetics* ; Polysaccharides/pharmacology* ; Astragalus Plant/chemistry* ; Drugs, Chinese Herbal/pharmacology* ; Adenocarcinoma/physiopathology* ; Cell Proliferation/drug effects* ; Glutathione Peroxidase/genetics* ; Reactive Oxygen Species/metabolism*

OBJECTIVES: To investigate the effect of nuclear protein (Nupr) 1 on the pathological progression of osteoarthritis and its relationship with ferroptosis of chondrocytes. METHODS: Chondrocytes from mouse knees were divided into small interfering RNA (siRNA) control group, small interfering RNA targeting Nupr1 (siNupr1) group, siRNA control+IL-1β group (siRNA control interference for 24 h followed by 10 ng/mL IL-1β) and siNupr1+IL-1β group (siNupr1 interference for 24 h followed by 10 ng/mL IL-1β). The protein and mRNA expressions of Nupr1 were detected by Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell proliferation viabilities were measured using the cell counting kit-8 method. The levels of ferrous ions were detected by FerroOrange staining. Lipid peroxidation levels were detected by C11-BODIPY-591 fluorescence imaging. The contents of malondialdehyde (MDA) and glutathione (GSH) were detected by enzyme-linked immunosorbent assay. The protein expressions of acyl-CoA synthetase long-chain family (ACSL) 4, P53, glutathione peroxidase (GPX) 4 and solute carrier family 7 member 11 gene (SLC7A11) were detected by Western blotting. The osteoarthritis model was constructed by destabilization of the medial meniscus (DMM) surgery in 7-week-old male C57BL/6J mice. The mice were randomly divided into four groups with 10 animals in each group: sham surgery (Sham)+adeno-associated virus serotype 5 (AAV5)-short hairpin RNA (shRNA) control group, Sham+AAV5-shRNA control targeting Nupr1 (shNupr1) group, DMM+AAV5-shRNA control group, and DMM+AAV5-shNupr1 group. Hematoxylin and eosin staining and Safranin O-Fast Green staining were used to observe the morphological changes in cartilage tissue. The Osteoarthritis Research Society International (OARSI) osteoarthritis cartilage histopathology assessment system was used to evaluate the degree of cartilage degeneration in mice. The mRNA expressions of matrix metallopeptidase (MMP) 13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5, cyclooxy-genase (COX) 2, and GPX4 were detected by qRT-PCR. RESULTS: In vitro experiments showed that knocking down Nupr1 alleviated the decrease of chondrocyte proliferation activity induced by IL-1β, reduced iron accumulation in mouse chondrocytes, lowered lipid peroxidation, downregulated ACSL4 and P53 protein expression and upregulated GPX4 and SLC7A11 protein expression (all P<0.01), thereby inhibiting ferroptosis in mouse chondrocytes. Meanwhile, in vivo animal experiments demonstrated that knocking down Nupr1 delayed the degeneration of articular cartilage in osteoarthritis mice, improved the OARSI score, slowed down the degradation of the extracellular matrix in osteoarthritis cartilage, and reduced the expression of the key ferroptosis regulator GPX4 (all P<0.01). CONCLUSIONS Knockdown of Nupr1 can delay the pathological progression of osteoarthritis through inhibiting ferroptosis in mouse chondrocytes.
Animals ; Ferroptosis ; Mice ; Chondrocytes/metabolism* ; Osteoarthritis/pathology* ; RNA, Small Interfering/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Interleukin-1beta/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Coenzyme A Ligases/genetics* ; Tumor Suppressor Protein p53/metabolism* ; Mice, Inbred C57BL ; DNA-Binding Proteins ; Neoplasm Proteins ; Amino Acid Transport System y+ ; Nuclear Receptor Subfamily 1, Group D, Member 1

Objective: To screen the key genes involved in gefitinib resistance of lung adenocarcinoma PC9/GR cells which harbored 19 exon mutation of epidermal growth factor receptor (EGFR) gene, and discuss the effect and mechanism of downregulation of solute carrier family 7 member 11 (SLC7A11) on the gefitinib resistance of PC9/GR cells. Methods: RNA microarray was conducted to detect the gene expressions in PC9 and PC9/GR cells. The differently expressed genes were screened by using limma package of R language and analyzed by Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Western blotting was performed to determine the expression of SLC7A11 protein in PC9 and PC9/GR cells. PC9/GR cells were infected with lentivirus plasmid containing short hairpin RNA (shRNA) targeting SLC7A11 or negative control shRNA (sh-NC), respectively. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to evaluate the efficacy of shRNA on the expression of SLC7A11 mRNA. Cell counting kit-8 (CCK-8) assay was conducted to determine the suppressing effect of gefitinib on PC9/GR cells. Mito-Tracker Red CMXRos probe and malondialdehyde (MDA) assay kit were used to evaluate gefitinib-induced ferroptosis in PC9/GR cells. Immunohistochemistry (IHC) was conducted to detect the expression of SLC7A11 protein in the tumor tissues of advanced stage lung adenocarcinoma patients harboring 19 exon mutation of EGFR gene. Thirty-six advanced stage lung adenocarcinoma patients who received EGFR-tyrosihe kinase inhibitor(TKI) as first-line treatment in Fourth Hospital of Hebei Medical Unviersity were enrolled. Kaplan-Meier survival curve was drawn to analyze the correlation between SLC7A11 expression and progression-free survival (PFS) of the patients. Results: RNA array demonstrated that 2 888 genes were differently expressed between PC9 and PC9/GR cells. KEGG analysis showed that ferroptosis-related gene was one of the most enriched region of the differently expressed genes between PC9 and PC9/GR cells. These ferroptosis-related gene cohort contained 13 genes, among which SLC7A11 exhibited the most significant difference. Western blotting showed that the expression of SLC7A11 protein in PC9/GR cells was significantly higher than that in PC9 cells (0.76±0.03 vs. 0.19±0.02, P<0.001). The 50% inhibiting concentration (IC(50)) of gefitinib was 35.08 μmol/L and 64.01 μmol/L for sh-SLC7A11 and sh-NC group PC9/GR cells, respectively. PC9/GR cells in sh-SLC7A11 group exhibited significantly lower density of mitochondria fluorescence after gefitinib treatment, compared to the sh-NC group (213.77±26.50 vs. 47.88±4.55, P<0.001). In addition, PC9/GR cells in sh-SLC7A11 group exhibited significantly higher MDA after gefitinib treatment, compared to the sh-NC group [(15.43±1.60) μmol/mg vs. (82.18±7.77) μmol/mg, P<0.001]. The PFS of the patients with low expression of SLC7A11 (n=18) was significantly longer than the patients with high expression of SLC7A11 (n=18, 16.77 months vs. 9.14 months, P<0.001). Conclusion: Downregulation of SLC7A11 could increase the sensitivity of PC9/GR cells to gefitinib by promoting ferroptosis.
Humans ; Gefitinib/therapeutic use* ; Antineoplastic Agents/therapeutic use* ; Lung Neoplasms/pathology* ; Down-Regulation ; Quinazolines/therapeutic use* ; Drug Resistance, Neoplasm/genetics* ; ErbB Receptors/metabolism* ; Adenocarcinoma of Lung ; Protein Kinase Inhibitors/therapeutic use* ; RNA, Small Interfering/genetics* ; Cell Line, Tumor ; Amino Acid Transport System y+/metabolism*

Objective: To screen the key genes involved in gefitinib resistance of lung adenocarcinoma PC9/GR cells which harbored 19 exon mutation of epidermal growth factor receptor (EGFR) gene, and discuss the effect and mechanism of downregulation of solute carrier family 7 member 11 (SLC7A11) on the gefitinib resistance of PC9/GR cells. Methods: RNA microarray was conducted to detect the gene expressions in PC9 and PC9/GR cells. The differently expressed genes were screened by using limma package of R language and analyzed by Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Western blotting was performed to determine the expression of SLC7A11 protein in PC9 and PC9/GR cells. PC9/GR cells were infected with lentivirus plasmid containing short hairpin RNA (shRNA) targeting SLC7A11 or negative control shRNA (sh-NC), respectively. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to evaluate the efficacy of shRNA on the expression of SLC7A11 mRNA. Cell counting kit-8 (CCK-8) assay was conducted to determine the suppressing effect of gefitinib on PC9/GR cells. Mito-Tracker Red CMXRos probe and malondialdehyde (MDA) assay kit were used to evaluate gefitinib-induced ferroptosis in PC9/GR cells. Immunohistochemistry (IHC) was conducted to detect the expression of SLC7A11 protein in the tumor tissues of advanced stage lung adenocarcinoma patients harboring 19 exon mutation of EGFR gene. Thirty-six advanced stage lung adenocarcinoma patients who received EGFR-tyrosihe kinase inhibitor(TKI) as first-line treatment in Fourth Hospital of Hebei Medical Unviersity were enrolled. Kaplan-Meier survival curve was drawn to analyze the correlation between SLC7A11 expression and progression-free survival (PFS) of the patients. Results: RNA array demonstrated that 2 888 genes were differently expressed between PC9 and PC9/GR cells. KEGG analysis showed that ferroptosis-related gene was one of the most enriched region of the differently expressed genes between PC9 and PC9/GR cells. These ferroptosis-related gene cohort contained 13 genes, among which SLC7A11 exhibited the most significant difference. Western blotting showed that the expression of SLC7A11 protein in PC9/GR cells was significantly higher than that in PC9 cells (0.76±0.03 vs. 0.19±0.02, P<0.001). The 50% inhibiting concentration (IC(50)) of gefitinib was 35.08 μmol/L and 64.01 μmol/L for sh-SLC7A11 and sh-NC group PC9/GR cells, respectively. PC9/GR cells in sh-SLC7A11 group exhibited significantly lower density of mitochondria fluorescence after gefitinib treatment, compared to the sh-NC group (213.77±26.50 vs. 47.88±4.55, P<0.001). In addition, PC9/GR cells in sh-SLC7A11 group exhibited significantly higher MDA after gefitinib treatment, compared to the sh-NC group [(15.43±1.60) μmol/mg vs. (82.18±7.77) μmol/mg, P<0.001]. The PFS of the patients with low expression of SLC7A11 (n=18) was significantly longer than the patients with high expression of SLC7A11 (n=18, 16.77 months vs. 9.14 months, P<0.001). Conclusion: Downregulation of SLC7A11 could increase the sensitivity of PC9/GR cells to gefitinib by promoting ferroptosis.
Humans ; Gefitinib/therapeutic use* ; Antineoplastic Agents/therapeutic use* ; Lung Neoplasms/pathology* ; Down-Regulation ; Quinazolines/therapeutic use* ; Drug Resistance, Neoplasm/genetics* ; ErbB Receptors/metabolism* ; Adenocarcinoma of Lung ; Protein Kinase Inhibitors/therapeutic use* ; RNA, Small Interfering/genetics* ; Cell Line, Tumor ; Amino Acid Transport System y+/metabolism*