PSIP1 promotes gefitinib resistance in lung adenocarcinoma by inducing the expression of WASF3 and its downstream ITGB3/AKT signaling.

BACKGROUND: Gefitinib (GR), a representative drug of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is a key pillar in the treatment of lung adenocarcinoma (LUAD), but drug resistance is universal. Identifying the potential factors of drug resistance to GR is essential to treat patients with EGFR mutant LUAD. METHODS: The GR-resistant LUAD cells were established and confirmed by MTT assay. The effects of PC4 and SRSF1 interacting protein 1 (PSIP1) on GR-resistant cell proliferation and apoptosis in vitro and in vivo were detected by colony formation, flow cytometry, tumor-bearing animal model, immunohistochemistry, and TUNEL staining. Western blotting and qPCR were used to determine the expression of relevant markers. The effect of PSIP1 on the promoter region of Wiskott-Aldrich syndrome protein family member 3 (WASF3) was detected by the dual-luciferase assay. The interaction between PSIP1 and RNA polymerase II was evaluated using ChIP-qPCR and Co-IP assays. RESULTS: PSIP1 was highly enriched in GR-resistant LUAD cells. Downregulation of PSIP1 expression significantly inhibited the proliferation of LUAD-resistant cells and promoted apoptosis. WASF3 was shown to have similar effects as PSIP1 in promoting drug resistance in LUAD cells. PSIP1 promoted the transcriptional activity of WASF3, which was achieved by increasing RNA polymerase II recruitment on the WASF3 promoter. Furthermore, PSIP1 positively regulated the expression of the pro-EGFR-TKI resistance factor integrin subunit beta 3 (ITGB3). CONCLUSION: Our work suggests that PSIP1 promotes resistance to GR in LUAD cells by inducing the expression of WASF3 and its downstream regulator ITGB3.

Genetic Variants in the ABCB1 and ABCG2 Gene Drug Transporters Involved in Gefitinib-Associated Adverse Reaction: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to verify the association between the genetic variants of adenosine triphosphate (ATP)-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily G member 2 (ABCG2) genes and the presence and severity of gefitinib-associated adverse reactions. We systematically searched PubMed, Virtual Health Library/Bireme, Scopus, Embase, and Web of Science databases for relevant studies published up to February 2024. In total, five studies were included in the review. Additionally, eight genetic variants related to ABCB1 (rs1045642, rs1128503, rs2032582, and rs1025836) and ABCG2 (rs2231142, rs2231137, rs2622604, and 15622C>T) genes were analyzed. Meta-analysis showed a significant association between the ABCB1 gene rs1045642 TT genotype and presence of diarrhea (OR = 5.41, 95% CI: 1.38-21.14, I2 = 0%), the ABCB1 gene rs1128503 TT genotype and CT + TT group and the presence of skin rash (OR = 4.37, 95% CI: 1.51-12.61, I2 = 0% and OR = 6.99, 95%CI: 1.61-30.30, I2= 0%, respectively), and the ABCG2 gene rs2231142 CC genotype and presence of diarrhea (OR = 3.87, 95% CI: 1.53-9.84, I2 = 39%). No ABCB1 or ABCG2 genes were positively associated with the severity of adverse reactions associated with gefitinib. In conclusion, this study showed that ABCB1 and ABCG2 variants are likely to exhibit clinical implications in predicting the presence of adverse reactions to gefitinib.

Overcoming Resistance to Osimertinib by T790M Loss and C797S Acquisition Using Gefitinib in a Patient With EGFR-Mutant NSCLC: A Case Report.

Limited strategies are available at disease progression on osimertinib for patients with EGFR-mutant NSCLC. The emergence of the on-target EGFR C797S mutation has been described as one of the most common mechanisms of resistance. In addition, loss of the EGFR T790M mutation has been mainly investigated as a resistance phenomenon to second-line osimertinib exposure. Remarkably, by studying the molecular profile at progression, it has been reported that the presence of the EGFR-sensitizing mutation, concurrently with the T790M, and C797S resulted in resistance to the current available EGFR tyrosine kinase inhibitors. Here, we report the first clinical evidence of gefitinib efficacy at EGFR exon 19 deletion/C797S mutation/T790M loss-mediated resistance to first-line osimertinib. Our findings highlight that dynamic genetic monitoring is a crucial approach in the evolution of EGFR-mutant NSCLC to understand the acquired molecular mechanisms for driving the best treatment strategy.

Comparison of gefitinib plus chemotherapy versus gefitinib alone for advanced non­small­cell lung cancer: A meta analysis.

This study aimed to perform a meta­analysis comparing the efficacy and safety of gefitinib in combination with chemotherapy versus gefitinib alone in patients with advanced Non­Small Cell Lung Cancer (NSCLC). We searched databases for clinical studies that reported the efficacy or safety of gefitinib plus chemotherapy in comparison with gefitinib alone. Raw data from included studies were extracted and pooled to calculate the Odds Ratio (OR) for Objective Response Rate (ORR) and Disease Control Rate (DCR), the Hazard Ratio (HR) for Progression-Free Survival (PFS) and Overall Survival (OS), and OR for complication ≥ Grade 3. A total of 10 studies containing 1,528 patients with NSCLC were identified and included in the analysis. Gefitinib plus chemotherapy showed significantly better efficacy in improving ORR (OR = 1.54; 95% CI [Confidence Interval], 1.13‒2.1; p = 0.006), DCR (OR = 1.62; 95% CI 1.14‒2.29; p = 0.007), PFS (HR=1.67; 95% CI 1.45‒1.94; p < 0.001) and OS (HR = 1.49; 95% CI 1.2‒1.87; p < 0.001) as compared with gefitinib alone. Consistent results were observed in the sub-population with positive EGFR mutation. The combination of gefitinib with chemotherapy had a significantly higher risk of complication (≥ Grade 3) with an OR of 3.29 (95% CI 2.57‒4.21; p < 0.001). The findings in the present study suggest that the combination of gefitinib with chemotherapy can provide better disease response and survival outcomes for patients with advanced NSCLC.

Comparison of gefitinib plus chemotherapy versus gefitinib alone for advanced non-small-cell lung cancer: A meta analysis

Abstract This study aimed to perform a meta-analysis comparing the efficacy and safety of gefitinib in combination with chemotherapy versus gefitinib alone in patients with advanced Non-Small Cell Lung Cancer (NSCLC). We searched databases for clinical studies that reported the efficacy or safety of gefitinib plus chemotherapy in comparison with gefitinib alone. Raw data from included studies were extracted and pooled to calculate the Odds Ratio (OR) for Objective Response Rate (ORR) and Disease Control Rate (DCR), the Hazard Ratio (HR) for Progression-Free Survival (PFS) and Overall Survival (OS), and OR for complication ≥ Grade 3. A total of 10 studies containing 1,528 patients with NSCLC were identified and included in the analysis. Gefitinib plus chemotherapy showed significantly better efficacy in improving ORR (OR = 1.54; 95% CI [Confidence Interval], 1.13‒2.1; p = 0.006), DCR (OR = 1.62; 95% CI 1.14‒2.29; p = 0.007), PFS (HR=1.67; 95% CI 1.45‒1.94; p < 0.001) and OS (HR = 1.49; 95% CI 1.2‒1.87; p < 0.001) as compared with gefitinib alone. Consistent results were observed in the sub-population with positive EGFR mutation. The combination of gefitinib with chemotherapy had a significantly higher risk of complication (≥ Grade 3) with an OR of 3.29 (95% CI 2.57‒4.21; p < 0.001). The findings in the present study suggest that the combination of gefitinib with chemotherapy can provide better disease response and survival outcomes for patients with advanced NSCLC.

Osimertinibe comparado a Erlotinibe Gefitinibe ou quimioterapia para tratamento de carcinoma pulmonar de células não pequenas com mutação do gene do receptor do fator de crescimento epidérmico (EFGR): revisão rápida / Osimertinib compared to erlotinib, gefitinib or chemotherapy for the treatment of non-small cell pumonary carcinoma with epidermal growth factor receptor (EFGR) gene mutation: rapid review

Mesilato de osimertinibe, gefitinibe, erlotinibe, quimioterapia padrão. Indicação: Câncer de pulmão de células não pequenas com mutação do receptor do fator de crescimento epidérmico (EGFR). Pergunta: Mesilato de osimertinibe é mais eficaz e seguro que gefitinibe, erlotinibe ou quimioterapia para os desfechos de sobrevida global, sobrevida livre de progressão e de segurança no tratamento de carcinoma pulmonar de células não pequenas com mutação do EGFR? Métodos: Levantamento bibliográfico foi realizado na base de dados PUBMED e EPISTEMONIKOS, seguindo estratégias de buscas predefinidas. Foi feita avaliação da qualidade metodológica das revisões sistemáticas com a ferramenta AMSTAR-2 (Assessing the Methodological Quality of Systematic Reviews Version 2). Resultados: Foram selecionadas duas revisões sistemáticas que atenderam aos critérios de elegibilidade. Conclusão: Mesilato de osimertinibe é mais eficaz do que gefitinibe ou erlotinibe na melhora da sobrevida global e da sobrevida livre de progressão em pacientes virgens de tratamento. Em pacientes previamente tratados, o mesilato de osimertinibe não é superior à quimioterapia padrão à base de platina no prolongamento da sobrevida global, mas é mais eficaz no aumento da sobrevida livre de progressão. Para câncer avançado, mesilato de osimertinibe não é mais eficaz do que a quimioterapia com ou sem pemetrexede para prolongar a sobrevida global, mas é mais eficaz em melhorar a sobrevida livre de progressão. Gefitinibe combinado com quimioterapia à base de pemetrexede foi superior à quimioterapia com ou sem pemetrexede na melhora da sobrevida global e da sobrevida livre de progressão

Osimertinib mesylate, gefitinib, erlotinib, standard chemotherapy. Indication: Non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutation. Question: Is osimertinib mesylate more effective and safer than gefitinib, erlotinib or chemotherapy for overall survival, progression-free survival and safety outcomes in the treatment of non-small cell lung cancer with EGFR mutation? Methods: A bibliographic search was done in the PUBMED and EPISTEMONIKOS database, following predefined search strategies. The methodological quality of systematic reviews was evaluated using the Assessing the Methodological Quality of Systematic Reviews Version 2 tool. Results: Two systematic reviews were selected because they met the eligibility criteria. Conclusion: Osimertinib mesylate is more effective than gefitinib or erlotinib in improving overall survival and progression-free survival in treatment-naive patients. In previously treated patients, osimertinib mesylate is not superior to standard platinum-based chemotherapy in prolonging overall survival, but it is more effective in increasing progression-free survival. For advanced cancer, osimertinib mesylate is not more effective than chemotherapy with or without pemetrexed in prolonging overall survival, but it is more effective in improving progression-free survival. Gefitinib combined with pemetrexed-based chemotherapy was superior to chemotherapy with or without pemetrexed in improving overall survival and progression-free survival

The Combination of Gefitinib With ATRA and ATO Induces Myeloid Differentiation in Acute Promyelocytic Leukemia Resistant Cells.

In approximately 15% of patients with acute myeloid leukemia (AML), total and phosphorylated EGFR proteins have been reported to be increased compared to healthy CD34+ samples. However, it is unclear if this subset of patients would benefit from EGFR signaling pharmacological inhibition. Pre-clinical studies on AML cells provided evidence on the pro-differentiation benefits of EGFR inhibitors when combined with ATRA or ATO in vitro. Despite the success of ATRA and ATO in the treatment of patients with acute promyelocytic leukemia (APL), therapy-associated resistance is observed in 5-10% of the cases, pointing to a clear need for new therapeutic strategies for those patients. In this context, the functional role of EGFR tyrosine-kinase inhibitors has never been evaluated in APL. Here, we investigated the EGFR pathway in primary samples along with functional in vitro and in vivo studies using several APL models. We observed that total and phosphorylated EGFR (Tyr992) was expressed in 28% and 19% of blast cells from APL patients, respectively, but not in healthy CD34+ samples. Interestingly, the expression of the EGF was lower in APL plasma samples than in healthy controls. The EGFR ligand AREG was detected in 29% of APL patients at diagnosis, but not in control samples. In vitro, treatment with the EGFR inhibitor gefitinib (ZD1839) reduced cell proliferation and survival of NB4 (ATRA-sensitive) and NB4-R2 (ATRA-resistant) cells. Moreover, the combination of gefitinib with ATRA and ATO promoted myeloid cell differentiation in ATRA- and ATO-resistant APL cells. In vivo, the combination of gefitinib and ATRA prolonged survival compared to gefitinib- or vehicle-treated leukemic mice in a syngeneic transplantation model, while the gain in survival did not reach statistical difference compared to treatment with ATRA alone. Our results suggest that gefitinib is a potential adjuvant agent that can mitigate ATRA and ATO resistance in APL cells. Therefore, our data indicate that repurposing FDA-approved tyrosine-kinase inhibitors could provide new perspectives into combination therapy to overcome drug resistance in APL patients.

Adjuvant therapy in non-small cell lung cancer: is targeted therapy joining the standard of care?

INTRODUCTION: Surgical resection is the standard of care  (SOC) in non-small cell lung cancer (NSCLC) for early-stage. The 5-year overall survival (OS) rates with the use of adjuvant chemotherapy remain low. In advance NSCLC, tailored strategies have become the gold standard. We hope to translate these benefits into preventing recurrences and increasing survival in early-stage NSCLC. AREAS COVERED: EGFR mutated populations are the most common druggable molecular drivers in advance NSCLC. EGFR tyrosine kinase inhibitors (TKIs) are the SOC in this setting, and we discuss their emerging role as adjuvant therapy. EXPERT OPINION: The results of the first adjuvant clinical trial with TKIs showed increased DFS in patients with early-stage NSCLC. Despite that using osimertinib (Osm) as an adjuvant treatment seems promising, several open questions need to be answered. If Osm reaches a significant advantage in OS, undergoing 3 years of treatment is worthwhile, but if there is not an OS benefit then maybe DFS is not enough. In the meantime, should we treat patients with Osm as adjuvant therapy until the OS data is available? There is not an easy answer, but most of us are in favor of giving Osm a chance until we have definitive data or better options in early-stage NSCLC.

Incremental cost-effectiveness analysis of tyrosine kinase inhibitors in advanced non-small cell lung cancer with mutations of the epidermal growth factor receptor in Colombia.

OBJECTIVE: To estimate the cost-effectiveness of sequences starting with tyrosine kinase inhibitors (TKI), afatinib and osimertinib, for the treatment of epidermal growth factor receptor (EGFR) mutation-positive (Exon 19 deletion or L858R) non-small cell lung cancer (NSCLC), stages IIIB - IV in Colombia. METHODS: A partitioned survival model was designed, using information from global and progression-free survival curves. For first and second-generation TKI, second line treatment was assumed according to the presence of T790M mutation to define the use of osimertinib or chemotherapy. The cost of the states without progression and post-progression was estimated using the base case approach, identified through consultation with clinical experts. RESULTS: The cost of treatment starting with afatinib in the first line was of 222,247 USD (1 USD = 3171.99 COP) and produced 1.36 QALYs. The strategy with afatinib was dominant with respect to that of first line TKI (227,289 USD and 1.34 QALY). The strategy with osimertinib resulted in more QALYs and higher costs, with ICERs of 35,062 USD, exceeding the current willingness to pay threshold for Colombia. CONCLUSIONS: Treatment starting with afatinib in the first line is dominant with respect to the strategy with first line TKI. The ICER of osimertinib sequence exceeds the threshold when compared with afatinib one.

Scanning Electron Microscopy of Subclinical Gefitinib-Induced Hair Changes.

Oral inhibitors of epidermal growth factor receptor may have a wide range of cutaneous manifestations. Hair manifestations are observed in 10%-20% of the patients. At the ultrastructural level erlotinib-induced hair changes were already described as acquired pili torti et canaliculi. We examined a 78-year-old female patient, with lung carcinoma, taking gefitinib for 15 months. The treatment has no side effects with good tolerance and tumor response. Although the patient had not observed any change on the hairs under the therapy, some specimens were obtained to be examined in natura with scanning electron microscopy. Under low magnification incipient grooving was observed on the hair surface, tortions or angulations of the hair shaft were not found. With higher magnifications the surface grooving was even more evident. Our findings show that gefitinib may cause subclinical hair changes, similar to those described at the ultrastructural level with erlotinib.

Combination of gefitinib and olaparib versus gefitinib alone in EGFR mutant non-small-cell lung cancer (NSCLC): A multicenter, randomized phase II study (GOAL).

OBJECTIVES: Progression-free survival (PFS) and response rate to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) varies in patients with non-small-cell lung cancer (NSCLC) driven byEGFR mutations, suggesting that other genetic alterations may influence oncogene addiction. Low BRCA1 mRNA levels correlate with longer PFS in erlotinib-treated EGFR-mutant NSCLC patients. Since the poly (ADP-ribose) polymerase (PARP) inhibitor, olaparib, may attenuate and/or prevent BRCA1 expression, the addition of olaparib to gefitinib could improve outcome in EGFR-mutant advanced NSCLC. MATERIALS AND METHODS: GOAL was a multicenter, randomized phase IB/II study performed in two countries, Spain and Mexico. Eligible patients were 18 years or older, treatment-naïve, pathologically confirmed stage IV NSCLC, with centrally confirmed EGFR mutations and measurable disease. Patients were randomly allocated (1:1) to receive gefitinib 250 mg daily or gefitinib 250 mg daily plus olaparib 200 mg three times daily in 28-day cycles. The primary endpoint was PFS. Secondary endpoints included overall survival (OS), response rate, safety and tolerability. RESULTS: Between September 2013, and July 2016, 182 patients underwent randomization, 91 received gefitinib and 91 received gefitinib plus olaparib. There were no differences in gender, age, smoking status, performance status, presence of bone and brain metastases or type ofEGFR mutation. Median PFS was 10.9 months (95 % CI 9.3-13.3) in the gefitinib arm and 12.8 months (95 % CI 9.1-14.7) in the gefitinib plus olaparib arm (HR 1.38, 95 % CI 1.00-1.92; p = 0.124). The most common adverse events were anemia, 78 % in gefitinib plus olaparib group, 38 % in gefitinib arm, diarrhea, 65 % and 60 %, and fatigue, 40 % and 32 %, respectively. CONCLUSIONS: The gefitinib plus olaparib combination did not provide significant benefit over gefitinib alone. The combination's safety profile showed an increase in hematological and gastrointestinal toxicity, compared to gefitinib alone, however, no relevant adverse events were noted.

Gefitinib promotes CXCR4-dependent epithelial to mesenchymal transition via TGF-ß1 signaling pathway in lung cancer cells harboring EGFR mutation.

PURPOSE: Epithelial to mesenchymal transition (EMT) plays an important role in acquired resistance to gefitinib in lung cancer. This study aimed to explore the underlying mechanism of gefitinib-induced EMT in lung adenocarcinoma cells harboring EGFR mutation. METHODS: CXC chemokine receptor 4 (CXCR4) expression was determined through qRT-PCR, Western blot and flow cytometry assays in lung cancer cell line (PC9) bearing mutated EGFR. Functional role of CXCR4 was inhibited applying siRNAs as well as the specific antagonist AMD3100. The expression of EMT markers was determined, and the migration of PC9 cells was measured with transwell assay. RESULTS: We found that gefitinib promoted the migratory capacity of PC9 cells in vitro, which correlated with EMT occurrence through upregulation of CXCR4. Blocking CXCR4 significantly suppressed gefitinib-induced enhancement of migration and EMT. Moreover, we determined that the upregulation of CXCR4 by gefitinib was dependent on TGF-ß1/Smad2 signaling activity. CONCLUSIONS: Our study suggested a potential mechanism by which gefitinib induced EMT in cells harboring EGFR mutation through a pathway involving TGF-ß1 and CXCR4. Thus, the combination of CXCR4 antagonist and TGFßR inhibitors might provide an alternative strategy to overcome progression of lung cancer after gefitinib treatment.

Potential life years not saved due to lack of access to anti-EGFR tyrosine kinase inhibitors for lung cancer treatment in the Brazilian public healthcare system: Budget impact and strategies to improve access. A pharmacoeconomic study

ABSTRACT BACKGROUND: Lung cancer is the fourth most common cancer in Brazil. In the 2000s, better understanding of molecular pathways led to development of epidermal growth factor receptor (EGFR)-targeted treatments that have improved outcomes. However, these treatments are unavailable in most Brazilian public healthcare services (Sistema Único de Saúde, SUS). OBJECTIVE: To assess the potential number of years of life not saved, the budget impact of the treatment and strategies to improve access. DESIGN AND SETTING: Pharmacoeconomic study assessing the potential societal and economic impact of adopting EGFR-targeted therapy within SUS. METHODS: We estimated the number of cases eligible for treatment, using epidemiological data from the National Cancer Institute. We used data from a single meta-analysis and from the Lung Cancer Mutation Consortium (LCMC) study as the basis for assessing differences in patients' survival between use of targeted therapy and use of chemotherapy. The costs of targeted treatment were based on the national reference and were compared with the amount reimbursed for chemotherapy through SUS. RESULTS: There was no life-year gain with EGFR-targeted therapy in the single meta-analysis (hazard ratio, HR, 1.01). The LCMC showed that 1,556 potential life-years were not saved annually. We estimated that the annual budget impact was 125 million Brazilian reais (BRL) with erlotinib, 48 million BRL with gefitinib and 52 million BRL with afatinib. Their incremental costs over chemotherapy per life-year saved were 80,329 BRL, 31,011 BRL and 33,225 BRL, respectively. A drug acquisition discount may decrease the budget impact by 30% (with a 20% discount). A fixed cost of 1,000 BRL may decrease the budget impact by 95%. CONCLUSION: Reducing drug acquisition costs may improve access to EGFR-targeted therapy for lung cancer.

ASTEMIZOLE, AN INHIBITOR OF ETHER-À-GO-GO-1 POTASSIUM CHANNEL, INCREASES THE ACTIVITY OF THE TYROSINE KINASE INHIBITOR GEFITINIB IN BREAST CANCER CELLS.

BACKGROUND: Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. OBJECTIVE: We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. MATERIALS AND METHODS: The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cy-tometry. RESULTS: Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. CONCLUSIONS: Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.

Astemizole, an inhibitor of ether-à-go-go-1 potassium channel, increases the activity of the tyrosine kinase inhibitor gefitinib in breast cancer cells

Abstract Background Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. Objective We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. Materials and Methods The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cytometry. Results Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. Conclusions Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.

Characteristics of progression to tyrosine kinase inhibitors predict overall survival in patients with advanced non-small cell lung cancer harboring an EGFR mutation.

BACKGROUND: Non-small cell lung cancer (NSCLC) harboring EGFR-sensitizing mutations has a distinct biology and heterogeneous clinical behavior. We evaluated the characteristics to progression such as clinical patterns of progression (dramatic, gradual, and local) with the prognosis of NSCLC patients treated with tyrosine kinase inhibitors (TKIs). METHODS: We reviewed 123 advanced-NSCLC patients with an EGFR-sensitizing mutation treated with TKIs (gefitinib, erlotinib and afatinib). We assessed patients according to clinical factors and progression pattern to TKIs at three centers. RESULTS: For all patients, 58.5%, 31.7% and 9.8% harbored exon19 deletion, exon21 L858R mutation and other-sensitivity mutations, respectively. Median progression-free survival (PFS) was 8.8 months (95% CI: 7.9-9.7). Sixty percent of patients were asymptomatic. Dramatic-progression was the most frequent pattern (50.4%), followed by gradual-progression (32.5%), and local-progression (17.1%). Median overall survival (OS) was 23.1 months (95% CI: 17.4-28.9). In the univariate analysis, factors associated to a longer OS included pattern [gradual-progression (32.1), dramatic (19.5) and local (18.8 months), P=0.008], and the time to progression to TKI [>12 months (38.5), 6-12 months (19.1), <6 months (9.6), P<0.001]. Multivariate analysis showed that only time to progression to TKI was independently associated to OS and PFS. CONCLUSIONS: Factors at TKI progression associated to a longer OS can define a subset of patients who may benefit from continued TKI therapy, as well as from local-ablative therapy in progression sites, especially in patients without T790M or who lack access to third-generation TKI.

Bevacizumab and gefitinib enhanced whole-brain radiation therapy for brain metastases due to non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) patients who experience brain metastases are usually associated with poor prognostic outcomes. This retrospective study proposed to assess whether bevacizumab or gefitinib can be used to improve the effectiveness of whole brain radiotherapy (WBRT) in managing patients with brain metastases. A total of 218 NSCLC patients with multiple brain metastases were retrospectively included in this study and were randomly allocated to bevacizumab-gefitinib-WBRT group (n=76), gefitinib-WBRT group (n=77) and WBRT group (n=75). Then, tumor responses were evaluated every 2 months based on Response Evaluation Criteria in Solid Tumors version 1.0. Karnofsky performance status and neurologic examination were documented every 6 months after the treatment. Compared to the standard WBRT, bevacizumab and gefitinib could significantly enhance response rate (RR) and disease control rate (DCR) of WBRT (P<0.001). At the same time, RR and DCR of patients who received bevacizumab-gefitinib-WBRT were higher than those who received gefitinib-WBRT. The overall survival (OS) rates and progression-free survival (PFS) rates also differed significantly among the bevacizumab-gefitinib-WBRT (48.6 and 29.8%), gefitinib-WBRT (36.7 and 29.6%) and WBRT (9.8 and 14.6%) groups (P<0.05). Although bevacizumab-gefitinib-WBRT was slightly more toxic than gefitinib-WBRT, the toxicity was tolerable. As suggested by prolonged PFS and OS status, bevacizumab substantially improved the overall efficacy of WBRT in the management of patients with NSCLC.

The combination astemizole-gefitinib as a potential therapy for human lung cancer.

Lung cancer is a major cause of cancer mortality. Thus, novel therapies are urgently needed. Repositioning of old drugs is gaining great interest in cancer treatment. Astemizole is an antihistamine proposed to be repositioned for cancer therapy. This drug targets several molecules involved in cancer including histamine receptors, ABC transporters and the potassium channels Eag1 and HERG. Astemizole inhibits the proliferation of different cancer cells including those from cervix, breast, leukemia and liver. Gefitinib is widely used to treat lung cancer; however, no response or drug resistance occurs in many cases. Here, we studied the combined effect of astemizole and gefitinib on the proliferation, survival, apoptosis and gene and protein expression of Eag1 channels in the human lung cancer cell lines A549 and NCI-H1975. Cell proliferation and survival were studied by the MTT method and the colony formation assay, respectively; apoptosis was investigated by flow cytometry. Gene expression was assessed by real-time polymerase chain reaction (RT-PCR), and protein expression was studied by Western blot analysis and immunocytochemistry. We obtained the inhibitory concentrations 20 and 50 (IC20 and IC50, respectively) values for each drug from the cell proliferation experiments. Drug combination at their IC20 had a superior effect by reducing cell proliferation and survival in up to 80% and 100%, respectively. The drugs alone did not affect apoptosis of H1975 cells, but the drug combination at their IC20 increased apoptosis roughly four times in comparison to the effect of the drugs alone. Eag1 mRNA levels and protein expression were decreased by the drug combination in A549 cells, and astemizole induced subcellular localization changes of the channel protein in these cells. Our in vitro studies strongly suggest that the combination astemizole-gefitinib may be a novel and promising therapy for lung cancer patients.

Gefitinib and pyrrolidine dithiocarbamate decrease viral replication and cytokine production in dengue virus infected human monocyte cultures.

AIMS: The epidermal growth factor receptor (EGFR) and nucleotide-binding and oligomerization-domain containing 2 (NOD2) are important in cancer and in microbial recognition, respectively. These molecules trigger intracellular signaling pathways inducing the expression of inflammatory genes by NF-kB translocation. Gefitinib (GBTC) and pyrrolidine dithiocarbamate (PDTC) are capable of inhibiting EGFR/NOD2 and NF-kB, respectively. In earlier stages of dengue virus (DENV) infection, monocytes are capable of sustaining viral replication and increasing cytokine production, suggesting that monocyte/macrophages play an important role in early DENV replication. GBTC and PDTC have not been used to modify the pathogenesis of DENV in infected cells. This study was aimed to determine the effect of GBTC and PDTC on viral replication and cytokine production in DENV serotype 2 (DENV2)-infected human monocyte cultures. MAIN METHODS: GBTC and PDTC were used to inhibit EGFR/NOD2 and NF-kB, respectively. Cytokine production was measured by ELISA and viral replication by plaque forming unit assay. KEY FINDINGS: Increased DENV2 replication and anti-viral cytokine production (IFN-α/ß, TNF-α, IL-12 and IL-18) in infected cultures were found. These parameters were decreased after EGFR/NOD2 or NF-kB inhibitions. SIGNIFICANCE: The inhibitory effects of GBTC and PDTC on viral replication and cytokine production can be beneficial in the treatment of patients infected by dengue and suggest a possible role of EGFR/NOD2 receptors and NF-kB in dengue pathogenesis.

HER2 overexpression reverses the relative resistance of EGFR-mutant H1975 cell line to gefitinib.

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) that has been demonstrated to be clinically useful for the treatment of patients with non-small cell lung cancer (NSCLC). However, ~50% of patients do not respond to EGFR TKI treatment through the emergence of mutations, such as T790M. Therefore, it is important to determine which patients are eligible for treatment with gefitinib. As a preferred dimerization partner for EGFR, the role of EGFR 2 (HER2) in mediating sensitivity to gefitinib is poorly understood. In the present study, full-length human HER2 cDNA was introduced to the NSCLC cell lines H1975 and H1299, which have a low endogenous expression level of HER2. In addition, it was observed in the present study that the H1975 cell line harbored the L858R and T790M mutations in the EGFR kinase domain. Western blot analysis and MTT assay were used to evaluate the TKI sensitivity of HER2 expression status, and the activation of HER3 and HER2 downstream effectors. The results indicated that the sensitivity of H1975 cells to gefitinib was restored by the overexpression of HER2, which stimulated HER2-driven signaling cascades accompanied by the activation of protein kinase B. By contrast, ectopic HER2 overexpression in H1299 cells did not significantly alter the sensitivity to gefitinib treatment. In conclusion, the current study results suggested that the relatively resistance of the H1975 cell line to gefitinib could be reversed by the overexpression of HER2. Therefore, the expression of HER2 could also be considered when evaluate the patients' potential response to gefitinib, particularly in the subgroup of lung cancer patients who harbor an EGFR mutation.