Effect of SLC7A11 gene downregulation on the gefitinib resistance of lung adenocarcinoma PC9/GR cells and its mechanism / 中华肿瘤杂志

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.

Effect of SLC7A11 gene downregulation on the gefitinib resistance of lung adenocarcinoma PC9/GR cells and its mechanism / 中华肿瘤杂志

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.

Novel analgesic targets and corresponding analgesic leading compounds / 中国药理学与毒理学杂志

Opioid medications have been used for pain management, but there are negative side effects, including a potential delay in recovery and increased risk of permanent disability. In this paper, analgesic targets including N-methyl-D-aspartate receptors, cannabinoid receptors, prostaglandin E2 receptor 4 receptors, matrix metalloproteinase receptors, and some new targets for blocking pain signaling pathways associated with these receptors are reviewed. In addition, some novel agonists, antagonists, and leading compounds with agonistic (antagonistic) activities interacting with the target are also described. These novel compounds usually have better analgesic activity and lower side effects than traditional opioids. They are expected to be developed into new analgesics and benefit clin?ical patients who need pain treatment.