HIF-1α-HPRT1 axis promotes tumorigenesis and gefitinib resistance by enhancing purine metabolism in EGFR-mutant lung adenocarcinoma.

BACKGROUND: The mutations of oncogenic epidermal growth factor receptor (EGFR) is an important cause of lung adenocarcinoma (LUAD) malignance. It has been knowm that metabolic reprogramming is an important hallmark of malignant tumors, and purine metabolism is a key metabolic pathway for tumor progression and drug resistance, but its relationship with the EGFR-mutant LUAD is unclear. METHODS: Metabolic reprogramming was studied through capillary electrophoresis-time of flight mass spectrometry (CE-TOF/MS)-based metabolic profiling analysis. Cell proliferation in vitro was evaluated by EdU staining and cell cycle assay. Tumorigenicity in vivo was tested by subcutaneous tumor formation experiment in nude mice. The binding of hypoxia-inducible factor-1 alpha (HIF-1α) and hypoxanthine phosphoribosyltransferase 1 (HPRT1) was detected by DNA pull­down assay and Chromatin immunoprecipitation (ChIP) assays. HIF-1α, HPRT1, DNA damage and cell apoptosis related genes were examined by western blot. In addition, RNA sequencing, mass spectrometry and bioinformatics analysis were performed. RESULTS: We found that mutated EGFR (muEGFR) upregulates HPRT1 to promote purine metabolism and tumorigenesis of EGFR-mutant LUAD. Mechanistically, muEGFR increases HIF-1α expression through protein stability. Meanwhile, up-regulated HIF-1α bound to the promoter of HPRT1 and transcriptionally activates HPRT1 expression, enhancing purine metabolism to maintain rapid tumor cell proliferation in EGFR-mutant LUAD. Further, gefitinib inhibited the synthesis of purine nucleotides, and HPRT1 inhibition increased the sensitivity of gefitinib to EGFR-mutant LUAD. CONCLUSIONS: Our study reveals that muEGFR-HIF-1α-HPRT1 axis plays a key role in EGFR-mutant LUAD and provides a new strategy-inhibiting purine metabolism for treating EGFR-mutant LUAD.

An "AND" logic gate-based supramolecular therapeutic nanoplatform for combatting drug-resistant non-small cell lung cancer.

Despite targeted therapies like epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), non-small cell lung cancer (NSCLC) remains a clinical challenge due to drug resistance hampering their efficacy. Here, we designed an "AND" logic gate-based supramolecular therapeutic platform (HA-BPY-GEF-NPs) for the treatment of EGFR-TKI resistant NSCLC. This system integrates both internal and external stimuli-responsive mechanisms that need to be activated in a preset sequence, enabling it to precisely control drug release behavior for enhancing therapeutic precision. By programming the system to respond to sequential near-infrared (NIR) irradiation and enzyme (cathepsin B) inputs, the release of gefitinib is effectively confined to the tumor region. Moreover, the NIR irradiation induces reactive oxygen species production, suppressing tumor growth and inhibiting bypass signaling pathways. The designed drug delivery system offers a highly controlled and targeted therapeutic approach, effectively inhibiting tumor growth, suppressing bypass signaling pathways, and overcoming EGFR-TKI resistance, thus offering a potential solution for maximizing therapeutic benefits.

CIB2 mediates acquired gefitinib resistance by inducing ZEB1 expression and epithelial-mesenchymal transition.

EGFR-TKIs have been used as frontline treatment in patients with advanced non-small cell lung cancer (NSCLC) suffering from the EGFR mutation. Gefitinib, the first-generation EGFR-TKI, has greatly improved survival rates in lung cancer patients, whereas acquired gefitinib resistance is still a critical issue that needs to be overcome. In our research, high expression levels of CIB2 were found in gefitinib-resistant lung cancer cells. CIB2 knockout rendered gefitinib-resistant cells more sensitive to gefitinib, and overexpression of CIB2 in parental cells was sufficient to induce more resistance to gefitinib. Inhibition of CIB2 in gefitinib-resistant lung cancer cells significantly induced cell apoptosis. To clarify the major molecular mechanism by which CIB2 increases gefitinib resistance, we demonstrated that raised CIB2 in lung cancer cells promoted epithelial-to-mesenchymal transition (EMT) through upregulation of ZEB1. Moreover, FOSL1 transcriptionally regulated CIB2 expression. Finally, CIB2 rendered tumors resistant to gefitinib treatment in vivo. Our results explored a new mechanism: upregulated CIB2 promoted EMT through ZEB1 to regulate gefitinib resistance, which could be a candidate therapeutic target for overcoming acquired resistance to EGFR-TKIs in NSCLC patients.

Deoxybouvardin targets EGFR, MET, and AKT signaling to suppress non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) remains a significant challenge, as it is one of the leading causes of cancer-related deaths, and the development of resistance to anticancer therapy makes it difficult to treat. In this study, we investigated the anticancer mechanism of deoxybouvardin (DB), a cyclic hexapeptide, in gefitinib (GEF)-sensitive and -resistant NSCLC HCC827 cells. DB inhibited the viability and growth of HCC827 cells in a concentration- and time-dependent manner. In vitro kinase assay showed DB inhibited epidermal growth factor receptor (EGFR), mesenchymal-epithelial transition (MET), and AKT, and their phosphorylation was suppressed in HCC827 cells treated with DB. A molecular docking model suggested that DB interacts with these kinases in the ATP-binding pockets. DB induces ROS generation and cell cycle arrest. DB treatment of HCC827 cells leads to mitochondrial membrane depolarization. The induction of apoptosis through caspase activation was confirmed by Z-VAD-FMK treatment. Taken together, DB inhibited the growth of both GEF-sensitive and GEF-resistant NSCLC cells by targeting EGFR, MET, and AKT and inducing ROS generation and caspase activation. Further studies on DB can improve the treatment of chemotherapy-resistant NSCLC through the development of effective DB-based anticancer agents.

Harnessing the CD44-targeted delivery of self-assembled hyaluronan nanogel to reverse the antagonism between Cisplatin and Gefitinib in NSCLC cancer therapy.

The combination of the standard platinum-based chemotherapy with EGFR-tyrosine kinase inhibitor Gefitinib (Gef) principally boosts the anticancer efficacy of advanced non-small cell lung cancer (NSCLC) through non-overlapping mechanisms of action, however the clinical trials of cisplatin (Cis) and Gef combination failed to show a therapeutic improvement likely due to compromised cellular influx of Cis with the Gef interference. To overcome the antagonism between Cis and Gef in anti-NSCLC therapy, here we demonstrated a self-targeted hyaluronan (HA) nanogel to facilitate the anticancer co-delivery by utilizing the HA's intrinsic targeting towards CD44, a receptor frequently overexpressed on lung cancer cells. The co-assembly between HA, Cis and Gef generated a HA/Cis/Gef nanogel of 177.8 nm, featuring a prolonged drug release. Unlike the Gef inhibited the Cis uptake, the HA/Cis/Gef nanogel efficiently facilitated the drug internalization through CD44-targeted delivery as verified by HA competition and CD44 knocking down in H1975 NSCLC model both in vitro and in vivo. Moreover, the HA/Cis/Gef nanogel significantly improved the anticancer efficacy and meanwhile diminished the side effects in reference to the combination of free Cis and Gef. This CD44-targeted HA/Cis/Gef nanogel provided a potent strategy to advance the platinum-based combination therapy towards optimized NSCLC therapy.

Efficacy on symptoms and mortality day vs. night administration of EGFR-TKIs for advanced non-small cell lung cancer.

PURPOSE: This study has a purpose to investigate the side effects of three EGFR-TKIs targeted therapeutic agents (gefitinib, erlotinib, and afatinib) and all-cause mortality in patients with metastatic lung cancer. METHODS: We performed a prospective cohort study. We selected all patients with newly diagnosed metastatic lung cancer between January and November 2019. Main exposure was daytime versus nighttime use of targeted EGFR TKIs. The study outcome was a symptom change using the mobile application, and all-cause mortality between January 2019 and March 2023. RESULTS: Among the 87 study participants, 35 (40%) took their medication at night. Among the 87 study participants, 35 (40%) took their medication at night. At 6 weeks of treatment, acne (1.36; 95% confidence interval [CI] 1.09, 1.64; p for interaction = 0.04) and dry skin (1.35; 95% CI 1.09, 1.61, p for interaction = 0.01) in the day group showed a much increase from baseline compared to the night group. In contrast, the night group reported greater reductions in lung cancer-related symptoms from baseline compared to the day. During follow-up (median 43 months), the night group had a lower risk of all-cause death than the day group, especially in younger patients (adjusted hazard ratio = 0.34; 95% CI 0.13, 0.87). CONCLUSIONS: The group taking EGFR-TKIs at night experienced fewer side effects and had longer overall survival compared to the day group. Clinicians should consider recommending that lung cancer patients take their once-daily oral anticancer drugs in the evening rather than the morning to improve treatment outcomes.

A case of high-grade non-intestinal paranasal sinus adenocarcinoma primary in the maxillary sinus: targeted therapy after postoperative immunocombination with chemotherapy.

BACKGROUND: High-grade non-intestinal-type sinonasal adenocarcinoma (non-ITAC) is a rare and aggressive form of adenocarcinoma with poor prognosis. The current standard treatment approach involves surgery combined with radiation therapy. However, there is a need for exploring additional treatment modalities to improve patient outcomes. CASE PRESENTATION: We present a case of a 65-year-old male patient who presented with pain in the right maxillary sinus and was diagnosed with high-grade non-ITAC following surgery. Postoperative pathology revealed tumor invasion into bone tissue and vascular invasion, necessitating further treatment. The patient underwent radiation therapy, followed by immunotherapy with carilizumab combined with chemotherapy. During the maintenance immunotherapy period, tumor progression was observed, and genetic testing identified EGFR and TP53 mutations. Consequently, the patient was treated with gefitinib, a targeted therapy drug. Notably, the patient's lung metastases showed a gradual reduction in size, indicating a favorable treatment response. The patient is currently undergoing oral treatment with gefitinib. CONCLUSIONS: This case report highlights the potential benefit of combining immunotherapy and targeted therapy in the treatment of high-grade non-ITAC. Despite the rarity of this cancer type, this approach may offer an alternative treatment strategy for patients with this aggressive disease. We hope that this case can contribute to a deeper understanding of high-grade non-ITAC and promote the application of immunotherapy and targeted therapy in improving survival rates for patients with this condition.

Gefitinib (an EGFR tyrosine kinase inhibitor) plus anlotinib (an multikinase inhibitor) for untreated, EGFR-mutated, advanced non-small cell lung cancer (FL-ALTER): a multicenter phase III trial.

Dual inhibition of vascular endothelial growth factor and epidermal growth factor receptor (EGFR) signaling pathways offers the prospect of improving the effectiveness of EFGR-targeted therapy. In this phase 3 study (ClinicalTrial.gov: NCT04028778), 315 patients with treatment-naïve, EGFR-mutated, advanced non-small cell lung cancer (NSCLC) were randomized (1:1) to receive anlotinib or placebo plus gefitinib once daily on days 1-14 per a 3-week cycle. At the prespecified final analysis of progression-free survival (PFS), a significant improvement in PFS was observed for the anlotinib arm over the placebo arm (hazards ratio [HR] = 0.64, 95% CI, 0.48-0.80, P = 0.003). Particularly, patients with brain metastasis and those harboring EGFR amplification or high tumor mutation load gained significant more benefits in PFS from gefitinib plus anlotinib. The incidence of grade 3 or higher treatment-emergent adverse events was 49.7% of the patients receiving gefitinib plus anlotinib versus 31.0% of the patients receiving gefitinib plus placebo. Anlotinib plus gefitinib significantly improves PFS in patients with treatment-naïve, EGFR-mutated, advanced NSCLC, with a manageable safety profile.

Macrophage-induced Expression of TonEBP/NFAT5 Is Associated With Gefitinib Resistance and Migration in PC-9 Cells.

BACKGROUND/AIM: Macrophages prevail in the microenvironment of several tumors, including non-small-cell lung cancer (NSCLC), where they secrete pro-tumorigenic factors that contribute to cancer progression. This study investigated the role of macrophages on the resistance of epidermal growth factor receptor (EGFR)-mutated NSCLC cells to tyrosine kinase inhibitors (TKIs). MATERIALS AND METHODS: EGFR-mutated cell lines PC-9 and HCC827 were cocultured with macrophages and treated with TKIs (erlotinib and gefitinib). The effects of the macrophage-conditioned medium (macrophage CM) on gefitinib resistance and cell migration were also evaluated. RESULTS: Co-culture with macrophages significantly enhanced the resistance to erlotinib and gefitinib in PC-9 and HCC827 cells compared to that in cells cultured independently. Macrophage CM markedly induced gefitinib resistance in PC-9 cells, with maximum resistance observed at 50% CM concentration. This resistance persisted for up to 48 h post-CM removal. Macrophage CM inhibited gefitinib-induced apoptosis, as evidenced by the decreased expression of cleaved caspase-3, PARP, and BIM. Additionally, macrophage CM increased the migration ability of PC-9 cells, as shown by the wound healing and transwell migration assays. Studies have shown that TonEBP is crucial in cancer metastasis and drug resistance; we found that inhibition of TonEBP/NFAT5 expression reduced gefitinib resistance and migration in macrophage CM-induced PC-9 cells, indicating its role as mediator of these effects. CONCLUSION: Macrophages contribute to TKI resistance and enhance the migration of EGFR-mutated NSCLC cells through mechanisms involving TonEBP/NFAT5. Therefore, targeting TonEBP/NFAT5 represents a potential therapeutic strategy for overcoming macrophage-induced TKI resistance in NSCLC cells.

EGFR-TKIs Combined with Allogeneic CD8+ NKT Cell Immunotherapy to Treat Patients with Advanced EGFR-Mutated Lung Cancer.

Background: To evaluate the efficacy and safety of allogenic CD8 + natural killer T (CD8+ NKT) immunotherapy combined with gefitinib in the treatment of advanced or metastatic EGFR mutant non-small cell lung cancer (NSCLC). Methods: This study is prospective. The NSCLC patients with exon 19 (Ex19del) or exon 21 L858R point mutations, and response to gefitinib treatment were enrolled into the trial to be randomly assigned into the gefitinib arm and the gefitinib/NKT arm. Allogenic CD8+ NKT cells were cultured in vitro and adaptive transferred into the patients via vein in the gefitinib/NKT arm. The primary endpoint was progression-free survival (PFS). Secondary endpoint analysis included time to disease progression (TTP), overall survival (OS), levels of serum tumour markers for carcinoembryonic antigen (CEA) and alanine aminotransferase (ALT) in the blood, the response rate and safety. From July 2017 to June 2021, 19 patients were randomly assigned to the gefitinib arm (n = 8) and the gefitinib/NKT arm (n = 11). Results: The estimated median survival PFS in the gefitinib/NKT arm was significantly longer than that of the gefitinib arm (12 months vs 7 months). Similar results were also observed for the median TTP. Moreover, the gefitinib/NKT arm had better CEA control than the gefitinib arm. Clinical grade 3 adverse reactions occurred in 64% and 39% of patients in the gefitinib/NKT arm and the gefitinib arm, respectively. The most common grade 3 adverse events in the gefitinib/NKT arm included abnormal liver function in 8 cases (73%) and diarrhoea in 1 case (9%), both of which resolved after drug intervention. Conclusion: The PFS of EGFR-mutated advanced NSCLC treated with allogenic CD8+ NKT cells combined with gefitinib was longer than that of gefitinib alone. No obvious serious adverse reactions occurred, and the patients compliance and survival status were good.

Inhibition of DDR1 promotes ferroptosis and overcomes gefitinib resistance in non-small cell lung cancer.

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which serves the critical pillar for the treatment of non-small cell lung cancer (NSCLC). However, the acquired resistance remains a challenge for its clinical application, for which, practical strategies to reverse gefitinib resistance in NSCLC are necessary. Ferroptosis, a programmed cell death driven by ferritin-dependent lipid peroxidation, involves in NSCLC progression and related chemoresistance. In our previous work, the self-synthesised EGFR inhibitor Yfq07 (N4, N6-disubstituted pyrimidine-4,6-diamine derivatives) displayed a considerable inhibitory effect on NSCLC both in vitro and in vivo. Herein, we observed that Yfq07 suppressed the proliferation of PC-9GR and HCC827GR cells, two gefitinib resistance NSCLC cell lines. Mechanically, Yfq07 inhibited the phosphorylation of the Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase (RTK) highly expressed in multiple cancers, accompanied by downregulated miR-3648 and upregulated SOCS2. Inhibition or knockdown of DDR1 suppressed the proliferation, migration, and invasion of gefitinib-resistant NSCLC cells, and on the other hand, also downregulated miR-3648 and promoted SOCS2 expression. More specifically, miR-3648 targeted the 3'UTR segment of SOCS2 mRNA and thus affecting the P-ERK signalling pathway to regulate the malignant behaviors of gefitinib-resistant NSCLC cells. Furthermore, Yfq07 also indirectly induced the ferroptosis of gefitinib-resistant NSCLC cells via SOCS2 triggered inhibition of xCT-GPX4 pathway. In conclusion, our study indicates that DDR1 inhibitor Yfq07 promotes ferroptosis and reverses gefitinib-resistance of NSCLC through DDR1-miR-3648-SOCS2 signalling pathway, which provides insights for targeted therapy of gefitinib-resistant NSCLC and drug developments targeting ferroptosis.

Complete response in a lung adenocarcinoma with pleural metastases initially treated with gefitinib and switched to osimertinib after cerebral oligo-progression with unknown T790M mutation: a case report and review of literature.

BACKGROUND: First- and second-generation anti-epithelial growth factor receptor tyrosine kinase inhibitors have shown great efficacy in the treatment of advanced adenocarcinoma with epithelial growth factor receptor mutations, but this efficacy is limited by certain resistance mechanisms, in particular the T790M mutation, which must be screened before second-line treatment with osimertinib is indicated. The search for this mutation is sometimes difficult, especially in cases of intracranial relapse, through this case report we attempt to discuss the possibility of initiating treatment with osimertinib despite an unknown T790M mutation in such situation. CASE REPORT: We present the case of a 70-year-old Moroccan male patient diagnosed with non-small cell lung carcinoma initially metastatic to the pleura with an epithelial growth factor receptor mutation who received gefitinib in first line with a complete response, he subsequently presented with cerebral oligo-progression with extra cranial stability. The patient was started on osimertinib with unknown T790M status, as it was impossible to perform a cerebral biopsy, the evolution was characterized by a partial response followed by stereotactic radiotherapy then a complete response for 2 years. CONCLUSION: We can discuss osimertinib as an option for patients with stage IV non-small cell lung cancer with brain oligo-progression on prior tyrosine kinase inhibitors and unknown T790M status, further studies are needed in this area.

HDAC1 and FOXK1 mediate EGFR-TKI resistance of non-small cell lung cancer through miR-33a silencing.

BACKGROUND: The development of acquired EGFR-TKI treatment resistance is still a major clinical challenge in the treatment of non-small cell lung cancer (NSCLC). This study aimed to investigate the role of HDAC1/FOXK1/miR-33a signaling in EGFR-TKI resistance. METHODS: The expression levels of miR-33a, HDAC1, and FOXK1 were examined using quantitative polymerase chain reaction (PCR) and bioinformatics analysis. Cell proliferation, migration, and apoptosis were explored by cell number assay, Transwell, and flow cytometry assays, respectively. After overexpression or knockdown of HDAC1, miR-33a expression in the cells, cell functions were tested. Immunoprecipitation and correlation analyses were used to evaluate the interaction between HDAC1 and FOXK1 protein. The tumor-suppressive role of miR-33a was investigated by animal experiments. RESULTS: The suppression of miR-33a increased TKI resistance by affecting cell proliferation, migration, and apoptosis in gefitinib-resistant cells. HDAC1 is the key upstream molecule that inhibits miR-33 expression. HDAC1 upregulation increased gefitinib resistance by its binding to FOXK1 in cells to silence miR-33a expression. MiR-33a overexpression exerts tumor-suppressive effects by negatively regulating ABCB7 and p70S6K1 expression. Moreover, overexpression of miR-33a inhibited tumor growth in a xenograft nude mouse model. CONCLUSIONS: HDAC1/FOXK1 upregulation and miR-33a silencing are new mechanisms of EGFR-TKI resistance in NSCLC.

PD-L1 induces autophagy and primary resistance to EGFR-TKIs in EGFR-mutant lung adenocarcinoma via the MAPK signaling pathway.

Resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) is a significant cause of treatment failure and cancer recurrence in non-small cell lung cancer (NSCLC). Approximately 30% of patients with EGFR-activating mutations exhibit primary resistance to EGFR-TKIs. However, the potential mechanisms of primary resistance to EGFR-TKIs remain poorly understood. Recent studies have shown that increased expression of programmed death ligand-1 (PD-L1) is associated with EGFR-TKIs resistance. Therefore, the present study aimed to investigate the mechanism of PD-L1 in primary resistance to EGFR-TKIs in EGFR-mutant lung adenocarcinoma (LUAD) cells. We found that PD-L1 was associated with poor prognosis in patients with EGFR-mutant LUAD, while the combination of EGFR-TKIs with chemotherapy could improve its therapeutic efficacy. In vitro and in vivo experiments revealed that PD-L1 promoted the proliferation and autophagy and inhibited the apoptosis of LUAD cells. Mechanistic studies demonstrated that upregulation of PD-L1 was critical in inducing autophagy through the mitogen-activated protein kinase (MAPK) signaling pathway, which was beneficial for tumor progression and the development of gefitinib resistance. Furthermore, we found that gefitinib combined with pemetrexed could synergistically enhance antitumor efficacy in PD-L1-overexpression LUAD cells. Overall, our study demonstrated that PD-L1 contributed to primary resistance to EGFR-TKIs in EGFR-mutant LUAD cells, which may be mediated by inducing autophagy via the MAPK signaling pathway. These findings not only help improve the prognosis of patients with EGFR-mutant LUAD but also provide a reference for the research of other cancer types.

CD44-hyaluronan mediating endocytosis of iron-platinum alloy nanoparticles induces ferroptotic cell death in mesenchymal-state lung cancer cells with tyrosine kinase inhibitor resistance.

While tyrosine kinase inhibitor resistance in cancer is a critical issue in the medical field, it is important for clinical testing as well, since it affects the ultimate outcome of cancer therapy. Yet, no effective solutions have been implemented till date. Clinical observations after tyrosine kinase inhibitor treatment reveal that acquired resistance inevitably limits the curative effects of non-small cell lung cancer treatment because of mutations in the epidermal growth factor receptor gene, which are accompanied by epithelial-mesenchymal transition. Here, for the first time, we report that the transmembrane glycoprotein CD44, which is associated with epithelial-mesenchymal transition, chemoresistance, and cancer progression, mediates enhanced endocytosis of iron-platinum alloy nanoparticles (FePt NPs) in the mesenchymal-state gefitinib-resistant (GR+ and M6) cells, via the binding of the CD44 ligand, hyaluronan, to the surface-absorbed hyaluronan-binding protein 2. Upon treatment with FePt NPs, there was higher cellular uptake in mesenchymal-state GR+ and M6 cells, resulting from cell death through ferroptosis and mitochondrial dysfunction, as compared to that observed in the epithelial-state cells. Mechanistically, inactivation of dihydroorotate dehydrogenase elevated the production of mitochondrial lipid peroxidation, and enhanced the cell death in the epithelial-state HCC827 cells, thereby indicating its role in defense against FePt NPs-induced ferroptosis. Furthermore, induction of ferroptosis has been shown to specifically promote the cell death of drug-tolerant "persister" cells and reverse their resistance as well. Therefore, we concluded that FePt NPs preferentially target mesenchymal drug-tolerant "persister" cells and promote ferroptosis, to overcome their resistance. STATEMENT OF SIGNIFICANCE: In the present study, we identified FePt NPs as an innovative agent for cancer treatment, particularly in mesenchymal-state cells that exhibit TKI resistance. Mesenchymal-state cancer cells showed enhanced uptake of FePt NPs via CD44-HA-mediated endocytosis, accompanied by severe cell death and mitochondrial morphology alterations, in comparison to epithelial-state cells. We further elucidated the mechanism underlying FePt NPs-induced ferroptotic cell death as via a burst of mitochondrial LPO and DHODH protein inactivation. In addition, we found that FePt NPs inhibit tumor growth in TKI-resistant mesenchymal GR+ cell-bearing mice with better efficacy than the ferroptotic inducer RSL3. Our current findings on using FePt NPs to overcome TKI resistance through ferroptosis activation may offer a alternative strategy for improved cancer treatment.

Impact of Interleukin-6 Activation and Arthritis on Epidermal Growth Factor Receptor (EGFR) Activation in Sensory Neurons and the Spinal Cord.

In tumor cells, interleukin-6 (IL-6) signaling can lead to activation of the epidermal growth factor receptor (EGFR), which prolongs Stat3 activation. In the present experiments, we tested the hypothesis that IL-6 signaling activates EGFR signaling in peripheral and spinal nociception and examined whether EGFR localization and activation coincide with pain-related behaviors in arthritis. In vivo in anesthetized rats, spinal application of the EGFR receptor blocker gefitinib reduced the responses of spinal cord neurons to noxious joint stimulation, but only after spinal pretreatment with IL-6 and soluble IL-6 receptor. Using Western blots, we found that IL-6-induced Stat3 activation was reduced by gefitinib in microglial cells of the BV2 cell line, but not in cultured DRG neurons. Immunohistochemistry showed EGFR localization in most DRG neurons from normal rats, but significant downregulation in the acute and most painful arthritis phase. In the spinal cord of mice, EGFR was highly activated mainly in the chronic phase of inflammation, with localization in neurons. These data suggest that spinal IL-6 signaling may activate spinal EGFR signaling. Downregulation of EGFR in DRG neurons in acute arthritis may limit nociception, but pronounced delayed activation of EGFR in the spinal cord may be involved in chronic inflammatory pain.

Influence of Tyrosine Kinase Inhibitors and Everolimus on TGFß1 and TGF-ß Receptor 2 in Squamous Cell Carcinoma Cells.

BACKGROUND/AIM: Transforming growth factor-ß (TGF-ß) plays a significant role in the formation of different cancer subtypes. There is evidence that TGF-ß pathways promote cancerogenic cell characteristics but also have tumor-suppressor capabilities. The tyrosine kinase inhibitors nilotinib, dasatinib, erlotinib, gefitinib, and everolimus are approved as targeted therapies for several tumor entities, including head and neck squamous cell carcinoma (HNSCC). This study aimed to investigate the effects of these substances on the expression levels of TGFß1 and TGF-ß receptor type 2 (TGFßR2) in HPV-negative and HPV-positive SCC cell cultures. MATERIALS AND METHODS: Expression patterns of TGFß1 and TGFßR2 were determined using enzyme-linked immunosorbent assay (ELISA) in three HNSCC cell lines (i.e., HNSCC-11A, HNSCC-14C, and CERV196). These cells were incubated with nilotinib, dasatinib, erlotinib, gefitinib, and everolimus (20 µmol/l) and compared to a chemonaive control. An assessment of concentration levels was conducted after 24, 48, 72, and 96 h of treatment. RESULTS: Statistically significant changes in the expression levels of TGFß1 and TGFßR2 were found in all tested cell cultures (p<0.05) compared to the negative control. An increase in TGFß-R2 expression was detected after treatment with most of the tested tyrosine kinase inhibitors, whereas a reduction in TGFß1 was observed. The addition of everolimus had the opposite effect on both TGFßR2 and TGF-B1- expression. CONCLUSION: Expression of TGFß1 and TGFßR2 was detected in all cultured HNSCC cell lines. Nilotinib, dasatinib, erlotinib, gefitinib, and everolimus had an impact on the expression levels of TGFß1 and TGFßR2 in vitro.

Erlotinib or Gefitinib for Treating Advanced Epidermal Growth Factor Receptor Mutation-Positive Lung Cancer in Aotearoa New Zealand: Protocol for a National Whole-of-Patient-Population Retrospective Cohort Study and Results of a Validation Substudy.

BACKGROUND: Starting in 2010, the epidermal growth factor receptor (EGFR) kinase inhibitors erlotinib and gefitinib were introduced into routine use in Aotearoa New Zealand (NZ) for treating advanced lung cancer, but their impact in this setting is unknown. OBJECTIVE: The study described in this protocol aims to understand the effectiveness and safety of these new personalized lung cancer treatments and the contributions made by concomitant medicines and other factors to adverse outcomes in the general NZ patient population. A substudy aimed to validate national electronic health databases as the data source and the methods for determining patient eligibility and identifying outcomes and variables. METHODS: This study will include all NZ patients with advanced EGFR mutation-positive lung cancer who were first dispensed erlotinib or gefitinib before October 1, 2020, and followed until death or for at least 1 year. Routinely collected health administrative and clinical data will be collated from national electronic cancer registration, hospital discharge, mortality registration, and pharmaceutical dispensing databases by deterministic data linkage using National Health Index numbers. The primary effectiveness and safety outcomes will be time to treatment discontinuation and serious adverse events, respectively. The primary variable will be high-risk concomitant medicines use with erlotinib or gefitinib. For the validation substudy (n=100), data from clinical records were compared to those from national electronic health databases and analyzed by agreement analysis for categorical data and by paired 2-tailed t tests for numerical data. RESULTS: In the validation substudy, national electronic health databases and clinical records agreed in determining patient eligibility and for identifying serious adverse events, high-risk concomitant medicines use, and other categorical data with overall agreement and κ statistic of >90% and >0.8000, respectively; for example, for the determination of patient eligibility, the comparison of proxy and standard eligibility criteria applied to national electronic health databases and clinical records, respectively, showed overall agreement and κ statistic of 96% and 0.8936, respectively. Dates for estimating time to treatment discontinuation and other numerical variables and outcomes showed small differences, mostly with nonsignificant P values and 95% CIs overlapping with zero difference; for example, for the dates of the first dispensing of erlotinib or gefitinib, national electronic health databases and clinical records differed on average by approximately 4 days with a nonsignificant P value of .33 and 95% CIs overlapping with zero difference. As of May 2024, the main study is ongoing. CONCLUSIONS: A protocol is presented for a national whole-of-patient-population retrospective cohort study designed to describe the safety and effectiveness of erlotinib and gefitinib during their first decade of routine use in NZ for treating EGFR mutation-positive lung cancer. The validation substudy demonstrated the feasibility and validity of using national electronic health databases and the methods for determining patient eligibility and identifying the study outcomes and variables proposed in the study protocol. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12615000998549; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368928. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/51381.

HB-EGF activates EGFR to induce reactive neural stem cells in the mouse hippocampus after seizures.

Hippocampal seizures mimicking mesial temporal lobe epilepsy cause a profound disruption of the adult neurogenic niche in mice. Seizures provoke neural stem cells to switch to a reactive phenotype (reactive neural stem cells, React-NSCs) characterized by multibranched hypertrophic morphology, massive activation to enter mitosis, symmetric division, and final differentiation into reactive astrocytes. As a result, neurogenesis is chronically impaired. Here, using a mouse model of mesial temporal lobe epilepsy, we show that the epidermal growth factor receptor (EGFR) signaling pathway is key for the induction of React-NSCs and that its inhibition exerts a beneficial effect on the neurogenic niche. We show that during the initial days after the induction of seizures by a single intrahippocampal injection of kainic acid, a strong release of zinc and heparin-binding epidermal growth factor, both activators of the EGFR signaling pathway in neural stem cells, is produced. Administration of the EGFR inhibitor gefitinib, a chemotherapeutic in clinical phase IV, prevents the induction of React-NSCs and preserves neurogenesis.

METTL1/FOXM1 promotes lung adenocarcinoma progression and gefitinib resistance by inhibiting PTPN13 expression.

INTRODUCTION: Lung adenocarcinoma (LUAD) is the most common malignant tumor in respiratory system. Methyltransferase-like 1 (METTL1) is a driver of m7G modification in mRNA. This study aimed to demonstrate the role of METTL1 in the proliferation, invasion and Gefitinib-resistance of LUAD. METHODS: Public datasets were downloaded from the Gene Expression Profiling Interactive Analysis (GEPIA) and GSE31210 datasets. Malignant tumor phenotypes were tested in vitro and in vivo through biological function assays and nude mouse with xenograft tumors. RNA immunoprecipitation assays were conducted to determine the interaction between METTL1 protein and FOXM1 mRNA. Public transcriptional database, Chromatin immunoprecipitation and luciferase report assays were conducted to detect the downstream target of a transcriptional factor FOXM1. Half maximal inhibitory concentration (IC50) was calculated to evaluate the sensitivity to Gefitinib in LUAD cells. RESULTS: The results showed that METTL1 was upregulated in LUAD, and the high expression of METTL1 was associated with unfavorable prognosis. Through the m7G-dependent manner, METTL1 improved the RNA stability of FOXM1, leading to the up-regulation of FOXM1. FOXM1 transcriptionally suppressed PTPN13 expression. The METTL1/FOXM1/PTPN13 axis reduced the sensitivity of LUAD cells to Gefitinib. Taken together, our data suggested that METTL1 plays oncogenic role in LUAD through inducing the m7G modification of FOXM1, therefore METTL1 probably is a new potential therapeutic target to counteract Gefitinib resistance in LUAD.