UNASSIGNED: To integrate pharmacovigilance and network toxicology methods to explore the potential adverse drug events (ADEs) and toxic mechanisms of selumetinib, and to provide a reference for quickly understanding the safety and toxicological mechanisms of newly marketed drugs.
UNASSIGNED: Taking selumetinib as an example, this study integrated pharmacovigilance methods based on real-world data and network toxicology methods to analyze its ADE and its potential toxicological mechanism. First, the ADE reports of selumetinib were extracted from the US Food and Drug Administration (FDA) adverse event reporting system (FAERS), and the ADE signals were detected by reporting odds ratio (ROR) and UK medicines and healthcare products regulatory agency (MHRA) methods. The ADE signals were classified and described according to the preferred terms (PTs) and system organ class (SOC) derived from the Medical Dictionary for Regulatory Activities (MedDRA). The network toxicology method was used to analyze the toxicological mechanism of the interested SOCs. The specific steps included predicting the potential targets of selumetinib using TOXRIC, STITCH, ChEMBL, CTD, SwissTargetPreditcion, and Super-PRED databases, collecting the targets of SOC using GeneCards database, conducting protein-protein interaction (PPI) analysis through STRING database, conducting gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analysis through DAVID database, and testing the molecular affinity using AutoDock software.
UNASSIGNED: A total of 1388 ADE reports related to selumetinib were extracted, and 53 positive signals were detected by ROR and MHRA methods, of which 20 signals were not mentioned in the package insert, including ingrowing nail, hyperphosphatemia, cardiac valve disease, hematuria, neutropenia, etc. Analysis of the toxicological mechanism of six SOCs involved in positive ADE signals revealed that the key targets included EGFR, STAT3, AKT1, IL6, BCL2, etc., and the key pathways included PI3K/Akt pathway, apoptosis, ErbB signaling pathway, and EGFR tyrosine kinase inhibitor resistance, etc. Molecular docking assays showed spontaneous binding of selumetinib to key targets in these pathways.
UNASSIGNED: The pharmacovigilance analysis identified some new potential ADEs of selumetinib, and the network toxicology analysis showed that the toxic effects of selumetinib may be related to PI3K/Akt pathway, apoptosis, ErbB signaling pathway, EGFR tyrosine kinase inhibitor resistance and other pathways.

BACKGROUND: Colorectal cancer (CRC) is the third most malignant tumor in the world. 5-fluorouracil (5‑FU) -based chemotherapy is the first-line chemotherapy scheme for CRC, whereas acquired drug resistance poses a huge obstacle to curing CRC patients and the mechanism is still obscure. Therefore, identification of genes associated with 5‑FU chemotherapy and seeking second-line treatment are necessary means to improve survival and prognosis of patients with CRC.
METHODS: The Cancer Therapeutics Response Portal (CTRP) database and Genomics of Drug Sensitivity in Cancer (GDSC) database were used to identify CRC-related genes and potential second-line therapies for 5-FU-resistant CRC. The single-cell RNA sequencing data for CRC tissues were obtained from a GEO dataset. The relationship between ITGA2 and 5-FU-resistant was investigated in vitro and in vivo models.
RESULTS: ACOX1 and ITGA2 were identified as risk biomarkers associated with 5-FU-resistance. We developed a risk signature, consisting of ACOX1 and ITGA2, that was able to distinguish well between 5-FU-resistance and 5-FU-sensitive. The single-cell sequencing data showed that ITGA2 was mainly enriched in malignant cells. ITGA2 was negatively correlated with IC50 values of most small molecule inhibitors, of which selumetinib had the highest negative correlation. Finally, knocking down ITGA2 can make 5-FU-resistant CRC cells sensitive to 5-FU and combining with selumetinib can improve the therapeutic effect of 5-FU resistant cells.
CONCLUSIONS: In summary, our findings demonstrated the critical role of ITGA2 in enhancing chemotherapy resistance in CRC cells and suggested that selumetinib can restore the sensitivity of chemotherapy-resistant CRC cells to 5-FU by inhibiting ITGA2 expression.

Selumetinib is an oral, effective, and selective tyrosine kinase inhibitor targeting mitogen-activated protein kinase 1 and 2 (MEK1/2), which is clinically active in multiple tumor types, such as neurofibromatosis type 1 (NF1), melanoma, gliomas and non-small cell lung cancer (NSCLC). The purpose of this article was to assess the effects of selumetinib on the activities of twelve human UDP-glucosyltransferases (UGTs) including UGT1A1, 1A3, 1A4, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B15, and 2B17, and its potential for inducing clinical drug-drug interactions (DDIs). The results demonstrated that selumetinib potently inhibited the activity of UGT2B7 through the mechanism of mixed inhibition with the inhibition constant value of 5.79 ± 0.65 μM. Furthermore, the plasma concentration of UGT2B7 substrate as the co-administered drug was predicted to be increased by at least 84 % when patients took selumetinib 75 mg twice daily, suggesting a high potential to induce clinical DDIs. Selumetinib exhibited weak inhibitory effects on other human UGTs and was unlikely to trigger off UGTs-mediated DDIs except for UGT2B7. Therefore, the combination of selumetinib with the substrate drug of UGT2B7 requires additional attention to avoid adverse events in clinical treatment.

BACKGROUND: The approval of selumetinib in patients with neurofibromatosis type 1(NF1) and inoperable plexiform neurofibromas (PN) has reshaped the landscape of clinical management of the disease, and further comprehensive evaluation of the drug\'s efficacy and safety is needed.
METHODS: Original articles reporting on the efficacy and safety of elumetinib in patients with NF1 were comprehensively searched in the Pubmed database, Embase database, Cochrane Library, and Web of Science database and screened for inclusion of studies that met the criteria. We pooled the objective response rate (ORR), disease control rate (DCR), disease progression rate (DPR), and the rate of improvement in PN-related complications using meta-analysis. The incidence of drug-related adverse events was also statistically analyzed.
RESULTS: This study included 10 clinical trials involving 268 patients. The pooled ORR was 68.0% (95% CI 58.0-77.3%), the DCR was 96.8% (95% CI 90.8-99.7%) and the DPR was only 1.4% (95% CI 0-4.3%). The pooled improvement rate was 75.3% (95% CI 56.2-90.9%) for pain and 77.8% (95% CI 63.1-92.5%) for motor disorders. Most adverse events were mild, with the most common being gastrointestinal reactions (diarrhea: 62.5%; vomiting: 54.5%).
CONCLUSIONS: Our study demonstrates that selumetinib is effective in patients with NF1 and PN, significantly improving the serious complications associated with PN as well as having tolerable toxicities. Our findings help to increase clinicians\' confidence in applying selumetinib and promote the clinical adoption and benefit of the new drug.

Gefitinib, as the first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has achieved great advances in the treatment of non-small cell lung cancer (NSCLC), but drug resistance will inevitably occur. Therefore, exploring the resistance mechanism of gefitinib and developing new combination treatment strategies are of great importance. In our study, the results showed that selumetinib (AZD6244) synergistically inhibited the proliferation of NSCLC with gefitinib. Selumetinib also enhanced gefitinib-induced apoptosis and migration inhibition ability in gefitinib-resistant lung cancer cell lines. Subsequently, the negative regulation between MIG6 and STAT3 was observed and verified through the STRING database and western blotting assays. Sustained activation of STAT3 was significantly downregulated when co-treatment with selumetinib in gefitinib-resistant cells. However, the downregulation of p-STAT3, resulting from the combination of selumetinib and gefitinib was counteracted by the deletion of MIG6, suggesting that selumetinib enhanced gefitinib sensitivity by regulating MIG6/STAT3 in NSCLC. In contrast, p-STAT3 was further inhibited after treatment with gefitinib and selumetinib when MIG6 was overexpressed. Furthermore, the combined administration of selumetinib and gefitinib effectively promoted the sensitivity of lung cancer xenografts to gefitinib in vivo, and the tumor inhibition rate reached 81.49%, while the tumor inhibition rate of the gefitinib monotherapy group was only 31.95%. Overall, MIG6/STAT3 negative regulation plays an important role in the sustained activation of STAT3 and the resistance to EGFR-TKIs. Our study also suggests that EGFR-TKIs combined with MEK1/2 inhibitors, such as selumetinib, may be beneficial to those NSCLC patients who develop a primary or acquired resistance to EGFR-TKIs, providing theoretical support for combining TKIs and selumetinib in clinical cancer treatment.

Background: Targeted therapy of Neurofibromatosis type 1 (NF1) related plexiform neurofibroma (pNF) aiming at MEK molecule has not demonstrated a convincing result for complete disease inhibition, probably due to other signal pathways crosstalk. Our previous study revealed an increased nuclear translocation of YAP molecule in NF1 related pNF. Herein, we decided to further investigate the therapeutic relations of YAP interference during the MEK treatment against NF1 related pNF. Methods: By means of selumetinib (MEK-inhibitor), RNA-sequencing was firstly performed to identify the changes of signal pathways in pNF Schwann cells, which was probably related to YAP regulation. Nuclear-cytoplasmic fractionation and western blotting were performed to show the intracellular YAP changes under selumetinib treatment. Thirdly, a series of in vitro assays were performed including flow cytometry, CCK-8, and colony/sphere formation under dual treatment of selumetinib and verteporfin (YAP-inhibitor). In addition, Chou-Talalay method was adopted to evaluate the synergistic inhibiting effects of such drug combination. Xenograft study was also used to detect the combining effects in vivo. Results: RNA-sequencing revealed that selumetinib treatment might be associated with the undesirable activation of Hippo pathway in NF1 related pNF tumor cells, which might reduce its pharmaceutic effects. Next, nuclear-cytoplasmic fractionation and further studies demonstrated that selumetinib could promote the nuclear translocation and transcriptional activation of YAP in vitro, which might cause the aforementioned resistance to selumetinib treatment. Additionally, when combined treatments were performed based on verteporfin and selumetinib, synergistic effects were observed on cytotoxicity of NF1 related pNF tumor cells in vitro and in vivo xenograft models. Conclusion: YAP inhibition can effectively sensitize NF1 related pNF tumor cells to selumetinib. Dual targeting of YAP and MEK might be a promising therapeutic strategy for treating NF1 related pNF.

UNASSIGNED: Non-small cell lung cancer (NSCLC) is the most common subtype of all lung cancers, and KRAS is the most common mutation in this population. Unfortunately, this subgroup remains \"undruggable\" with the lack of an approved targeted therapy. Selumetinib has been investigated as a secondary therapy in several trials and compared to various drug regimens. Therefore, we conducted this systematic review and network meta-analysis to determine the comparative effectiveness of this drug as compared to others in patients with late-stage and malignant NSCLC.
UNASSIGNED: Up to July 1, 2020, 9 databases (PubMed, Scopus, Web of Science, mRCT, ICTRP, clinicaltrials.gov, VHL, SIGLE, and Google Scholar) were searched for studies following the PICOS framework: randomized trials reporting the efficacy (rate of disease progression/lack of response) of selumetinib compared to other therapies in patients with late-stage/metastatic NSCLC. The quality of retrieved studies were assessed with the revised Cochrane risk-of-bias tool. Frequentist network meta-analysis was conducted to estimate the efficacy of selumetinib as compared to other therapies and/or placebo.
UNASSIGNED: Out of the 163 articles yielded from the primary search, 9 studies (1,195 patients) were finally included in our systematic review. The majority of clinical cases had a performance status (PS) of 0-2, and the mean age was 62 years. The overall efficacy of selumetinib was 71.77% (95% CI: 63.24-81.45%), with selumetinib administered alone having better efficacy compared to combined therapy (65.20% vs. 74.08%). In the network analysis, selumetinib had higher efficacy compared to chemo- or immune therapy, but not significantly so. The overall SAE rate of selumetinib was 42.96% (95% CI: 34.74-53.13%), with selumetinib having a significantly better safety profile compared to combined therapy (10.49% vs. 47.38%). In the network analysis, the placebo had the best safety profile followed by selumetinib and chemo- and immune therapy. Five studies had high risk of bias, 2 had some concerns, and 2 had low risk of bias.
UNASSIGNED: The efficacy of selumetinib is not superior compared to combined therapy for treating NSCLC but does have a better safety profile. Current evidence is still limited, and more robust trials are still required.

Based on molecular docking and molecular dynamics simulation, to find a new target and mechanism of MEK inhibitor Selumetinib in the treatment of low-grade glioma (LGG), and to provide theoretical guidance for its clinical medication. All possible targets of Selumetinib were fished through the compound target prediction database. New targets of Selumetinib in the treatment of LGG were found and its mechanism was evaluated employing molecular docking, gene difference analysis, molecular dynamics simulation, and protein subcellular localization prediction. A total of 100 Selumetinib targets and 85 LGG-related targets were screened in this study. There were 7 active targets at the intersection of the two. Through protein interaction (PPI), gene enrichment analysis, and gene difference analysis, one effective target of Selumetinib was finally screened, CDK2 mainly existing in the cytoplasm, endoplasmic reticulum, and plasma membrane; the target plays a role in the treatment of LGG by inhibiting the signal pathways of PI3K Akt and participating in biological processes such as peptide amino acid modification, regulation of intracellular signal transduction, and positive regulation of cell metabolism. CDK2 may be a new direction of Selumetinib in the clinical treatment of LGG.

This study aimed to investigate the effects of luteolin on colorectal cancer (CRC) and explore its underlying mechanism. HCT-116 and HT-29 cells were treated with luteolin, cisplatin, or selumetinib. The cell survival, cell proliferation, apoptosis and cell cycle distribution, and DNA damage were detected using Cell Counting Kit-8, colony formation, flow cytometry, and immunofluorescence staining analysis, respectively. Western blotting was used to detect the expression of apoptosis-related, cycle-related, DNA-damage-related, and mitogen-activated protein kinase (MAPK) pathway-related proteins. Luteolin showed inhibitory effects on cellular growth by reducing cell survival and proliferation, inducing apoptosis and DNA damage, and arresting the cell cycle in a concentration-dependent manner in HCT-116 and HT-29 cells. Meanwhile, luteolin increased the expression of pro-apoptotic proteins, p-CHK1 (central to the induction of cell cycle arrest), and DNA excision repair protein and decreased anti-apoptotic proteins, G2-M phase-related proteins, and DNA repair proteins. The combination of cisplatin and luteolin significantly decreased cell survival and increased the apoptosis rate of HCT-116 and HT-29 cells compared with cisplatin alone. Bioinformatic analysis using the Comparative Toxicogenomics Database and STITCH and MalaCards databases showed that the MAPK pathway is involved in the pharmacology of luteolin. Furthermore, western blotting demonstrated that luteolin plays an inhibitory role by suppressing the MAPK signaling pathway in CRC, which is enhanced when combined with selumetinib. Luteolin can also prevent tumourigenesis in CRC in vivo. In conclusion, luteolin suppressed cell proliferation, blocked the cell cycle, and induced DNA damage and apoptosis progression in CRC cells by mediating the MAPK pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumours worldwide and has a poor prognosis. Sorafenib, the only targeted therapeutic agent for HCC, is a multiple kinase inhibitor with targets including RAF and VEGFR-2/3 that display a very limited ability to extend the survival of patients with advanced metastatic HCC for approximately three months. MEK inhibitors including trametinib and selumetinib have shown promising efficacy in combination with sorafenib in clinical trials. However, the mechanisms about the combined effect of these drugs remain unclear.
METHODS: Two HCC cell lines (Bel7402 and SMMC7721) were used in the experiments. The protein expression of HCC cell lines was quantified via western blotting. Cell viability was examined by cell counting kit-8 and colony formation assays. Drug interactions between sorafenib and trametinib/selumetinib were determined by the combination index (CI) value.
RESULTS: In this study, we found that short-term sorafenib treatment could inhibit the downstream RAF effectors phosphorylated (p)-MEK and p-ERK in Bel7402 and SMMC7721 cells, while long-term sorafenib treatment could induce a rebound of p-MEK and p-ERK expression in these two human HCC cell lines. We then tested the effect of sorafenib combined with two different FDA-approved MEK inhibitors, trametinib and selumetinib, in the two cell lines. Western blot analysis showed that trametinib/selumetinib could abolish the ERK activation caused by long-term sorafenib treatment. Cell counting kit-8 and colony formation assays indicated that the use of sorafenib or trametinib/selumetinib alone produced a minor effect on the proliferation of these HCC cell lines, while the combination therapies induced strong growth inhibition. CI assays using CompuSyn software indicated that the combined therapies could produce a synergistic effect in these two cell lines. In addition, mechanistic studies revealed that the combination therapies could synergistically reduce the expression of proliferation-related proteins, including cyclin D1 and c-Myc.
CONCLUSIONS: Taken together, our study showed that the rebound of p-ERK induced by long-term sorafenib treatment might limit the benefit of sorafenib monotherapy, and the MEK inhibitors trametinib and selumetinib could enhance the efficacy of sorafenib in HCC cells.