Project description:The epidermal growth factor receptor (EGFR) is a therapeutic target (oncotarget) in NSCLC. Using in vitro EGFR kinase activity system, we identified a novel small molecule, WB-308, as an inhibitor of EGFR. WB-308 decreased NSCLC cell proliferation and colony formation, by causing G2/M arrest and apoptosis. Furthermore, WB-308 inhibited the engraft tumor growths in two animal models in vivo (lung orthotopic transplantation model and patient-derived engraft mouse model). WB-308 impaired the phosphorylation of EGFR, AKT, and ERK1/2 protein. WB-308 was less cytotoxic than Gefitinib. Our study suggests that WB-308 is a novel EGFR-TKI and may be considered to substitute for Gefitinib in clinical therapy for NSCLC.
Project description:The targeting of oncogenic 'driver' kinases with small molecule inhibitors has proven to be a highly effective therapeutic strategy in selected non-small cell lung cancer (NSCLC) patients. However, acquired resistance to targeted therapies invariably arises and is a major limitation to patient care. ROS1 fusion proteins are a recently described class of oncogenic driver, and NSCLC patients that express these fusions generally respond well to ROS1-targeted therapy. In this study, we sought to determine mechanisms of acquired resistance to ROS1 inhibition. To accomplish this, we analyzed tumor samples from a patient who initially responded to the ROS1 inhibitor crizotinib but eventually developed acquired resistance. In addition, we generated a ROS1 inhibition-resistant derivative of the initially sensitive NSCLC cell line HCC78. Previously described mechanisms of acquired resistance to tyrosine kinase inhibitors including target kinase-domain mutation, target copy number gain, epithelial-mesenchymal transition, and conversion to small cell lung cancer histology were found to not underlie resistance in the patient sample or resistant cell line. However, we did observe a switch in the control of growth and survival signaling pathways from ROS1 to EGFR in the resistant cell line. As a result of this switch, ROS1 inhibition-resistant HCC78 cells became sensitive to EGFR inhibition, an effect that was enhanced by co-treatment with a ROS1 inhibitor. Our results suggest that co-inhibition of ROS1 and EGFR may be an effective strategy to combat resistance to targeted therapy in some ROS1 fusion-positive NSCLC patients.
Project description:Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) targeted therapy has become the standard of care for patients with EGFR-mutated metastatic non-small cell lung cancer (NSCLC) on the basis of improved prognosis and reduced toxicities compared with chemotherapy. In view of the therapeutic potential of EGFR-TKIs in EGFR-mutated advanced NSCLC, several scholars have explored the value of preoperative use of EGFR-TKIs in patients with EGFR-mutated resectable NSCLC. However, the field of neoadjuvant targeted therapy for EGFR-mutated resectable NSCLC is currently in its infancy. In this mini-review, we summarize the current evidence on neoadjuvant EGFR-TKIs targeted therapy for resectable EGFR-mutated NSCLC and focus on discussing potential clinical strategies of treating resectable EGFR-mutated patients by preoperative administration of EGFR-TKIs-based multimodality therapy.
Project description:BackgroundAdjuvant platinum-based chemotherapy is standard of care for patients with resected stage IIA/B or IIIA NSCLC. Overall survival is suboptimal due to the high metastatic potential of early-stage NSCLC and there is substantial clinical need for additional efficacious adjuvant treatment options.MethodsPubMed (all time to 4 February 2021) and related conference databases were searched using the key search terms 'NSCLC' AND 'Adjuvant' AND 'EGFR inhibitor' OR respective aliases.ResultsThe literature search identified five adjuvant phase III trials of EGFR inhibitors in early NSCLC. The earlier BR19 and RADIANT trials failed to demonstrate statistically significant improvements in either OS or DFS for gefitinib and erlotinib, respectively, compared with placebo in patients with EGFR mutation-unselected NSCLC. Three subsequent phase III trials, ADAURA, CTONG1104, and IMPACT, were conducted in EGFR-mutant NSCLC. IMPACT showed no statistically significant DFS benefit for adjuvant gefitinib, and although CTONG1104 did report improved DFS for gefitinib (HR = 0.56, p = 0.001), this benefit was not enduring, resulting in comparable 5-year DFS rates. Statistically significant and clinically meaningful DFS benefits were observed in ADAURA for osimertinib compared with placebo in patients with stage IB-IIIA and II-IIIA disease (7th Edition Staging), and these benefits, coupled with a meaningful improvement in 2-year CNS DFS and favorable HRQoL, make osimertinib an important new treatment option for the adjuvant treatment of EGFR exon 19 deletion or exon 21 L858R-mutated stage II-IIIA NSCLC (UICC/AJCC 8th Edition Staging), with final mature OS data eagerly awaited.ConclusionAdjuvant osimertinib used alone or following platinum-based chemotherapy is now recommended in patients with stage II-IIIA EGFR-mutated NSCLC.
Project description:Cluster of differentiation 44 (CD44) as a transmembrane glycoprotein is found to be expressed in non‑small cell lung cancer (NSCLC), is significantly associated with NSLC progression, metastasis and drug resistance. This study aimed to explore whether CD44 inhibition improves the sensitivity of epidermal growth factor receptor (EGFR) wild‑type NSCLC cells to cisplatin and how it affects wild‑type EGFR in NSCLC cells. Small interfering RNA was used to knockdown CD44 expression in EGFR wild‑type NSCLC cell line H460. Results suggested that CD44 downregulation reduced cell growth, promoted G0/G1 cell cycle arrest and induced cell apoptosis in H460 cells and these effects were evidently enhanced when in combination with cisplatin. Deactivation of EGFR signaling pathway including EGFR phosphorylation and its downstream molecules, targets ERK, AKT1 and SRC which were also observed in CD44‑silenced H460 cells with or without EGF stimulation. Furthermore, the CD44 expression level was positively correlated with wild‑type EGFR level in human lung adenocarcinoma tissues and CD44 inhibition significantly accelerated the degradation of EGFR, indicating that enhanced sensitivity of H460 cells to cisplatin by downregulation of CD44 might be due to EGFR degradation. This study demonstrated that suppression of CD44 deactivated EGFR signals in NSCLC cells with wild‑type EGFR, thereby contributing to the inhibition of cell proliferation and the reinforcement of cisplatin sensitivity. It is suggested that downregulation of CD44 could be a novel potential therapeutic strategy for the treatment of EGFR wild‑type NSCLC.
Project description:In non-small cell lung cancer (NSCLC), activating mutations in the epidermal growth factor receptor (EGFR) induce sensitivity to EGFR tyrosine kinase inhibitors. Despite impressive clinical responses, patients ultimately relapse as a reservoir of drug-tolerant cells persist, which ultimately leads to acquired resistance mechanisms. We performed an unbiased high-throughput siRNA screen to identify proteins that abrogate the response of EGFR-mutant NSCLC to EGFR-targeted therapy. The deubiquitinase USP13 was a top hit resulting from this screen. Targeting USP13 increases the sensitivity to EGFR inhibition with small molecules in vitro and in vivo. USP13 selectively stabilizes mutant EGFR in a peptidase-independent manner by counteracting the action of members of the Cbl family of E3 ubiquitin ligases. We conclude that USP13 is a strong mutant EGFR-specific cotarget that could improve the treatment efficacy of EGFR-targeted therapies.
Project description:For appropriate treatment selection, the updated NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC) recommend broad molecular profiling for all patients with nonsquamous disease. Three different tyrosine kinase inhibitors (TKIs) are recommended as first-line treatment of EGFR mutation-positive NSCLC: gefitinib, erlotinib, and afatinib. Most patients whose disease responds will still experience progression, and the type of disease progression drives management. Systemic progression requires switching TKI treatment, whereas patients with oligoprogression and central nervous system progression may have their new lesions treated but continue on their TKI. A new third-generation TKI has been approved and others are currently under development, and new combinations of these drugs with a VEGFR inhibitor offer promise to improve outcomes.
Project description:Drug resistance can notably restrict clinical applications of gefitinib that is a commonly used EGFR-tyrosine kinase inhibitors (EGFR-TKIs) for non-small cell lung cancer (NSCLC). The attempts in exploring novel drug targets and reversal strategies are still needed, since gefitinib resistance has not been fully addressed. Protease-activated receptor 2 (PAR2), a G protein-coupled receptor, possesses a transactivation with EGFR to initiate a variety of intracellular signal transductions, but there is a lack of investigations on the role of PAR2 in gefitinib resistance. This study established that protease-activated receptor 2 (PAR2), actively participated in NSCLC resistant to gefitinib. PAR2 expression was significantly up-regulated when NSCLC cells or tumor tissues became gefitinib resistance. PAR2 inhibition notably enhanced gefitinib to modulate EGFR transactivation, cell viability, migration and apoptosis in gefitinib-sensitive and-resistant NSCLC cells, suggesting its reversal effects in gefitinib resistance. Meanwhile, the combination of a PAR2 inhibitor (P2pal-18S) and gefitinib largely blocked ERK phosphorylation and epithelial-mesenchymal transition (EMT) compared to gefitinib alone. Importantly, we probed its underlying mechanism and uncovered that PAR2 blockade sensitized gefitinib and reversed its resistance mainly via β-arrestin-EGFR-ERK signaling axis. These effects of PAR2 inhibition were further confirmed by the in vivo study which showed that P2pal-18S reactivated gefitinib to inhibit tumor growth via restricting ERK activation. Taken together, this study could not only reveal a new mechanism of receptor-mediated transactivation to modulate drug resistance, but also provide a novel drug target and direction for overcoming gefitinib resistance in NSCLC.
Project description:Epidermal growth factor receptor (EGFR) is overexpressed in lung cancer patients. Despite treatment with various EGFR tyrosine kinase inhibitors, recurrence and metastasis of lung cancer are inevitable. Docetaxel (DTX) is an effective conventional drug that is used to treat various cancers. Several researchers have studied the use of traditional herbal medicine in combination with docetaxel, to improve lung cancer treatment. SH003, a novel herbal mixture, exerts anticancer effects in different cancer cell types. Here, we aimed to investigate the apoptotic and anticancer effects of SH003 in combination with DTX, in human non-small-cell lung cancer (NSCLC). SH003, with DTX, induced apoptotic cell death, with increased expression of cleaved caspases and cleaved poly (ADP-ribose) polymerase in NSCLC cells. Moreover, SH003 and DTX induced the apoptosis of H460 cells via the suppression of the EGFR and signal transducer and activator of transcription 3 (STAT3) signaling pathways. In H460 tumor xenograft models, the administration of SH003 or docetaxel alone diminished tumor growth, and their combination effectively killed cancer cells, with increased expression of apoptotic markers and decreased expression of p-EGFR and p-STAT3. Collectively, the combination of SH003 and DTX may be a novel anticancer strategy to overcome the challenges that are associated with conventional lung cancer therapy.