Lower optimal dose of amrubicin for relapsed small-cell lung cancer: a retrospective study.

BACKGROUND: Amrubicin (AMR) is one of the most active agents for small-cell lung cancer (SCLC). However, hematologic toxicity and infection at a commonly used dose (40 mg/m2) is problematic; the optimal dose remains undetermined. PATIENTS AND METHODS: To evaluate the optimal dose of AMR in terms of efficacy and safety, we reviewed consecutive data on patients with relapsed SCLC who received AMR at doses of 40, 35, and 30 mg/m2 (on days 1-3) at Nippon Medical School Hospital between October 2010 and November 2021. RESULTS: We reviewed the data of 86 patients (20, 45, 27 who received AMR doses of 40, 35, 30 mg/m2, respectively) according to our study criteria. For patients ≥ 75 years, the proportion who received second-line treatment tended to be higher in the 30-35 mg/m2 group. Objective response rates were 37/46/35%, median progression-free survival (PFS) were 3.0/4.7/3.2 months, and median overall survival (OS) were 7.8/16.3/8.0 months, respectively. Grade 4 neutropenia occurred in 58/39/31% of patients, which was higher for the 40 mg/m2 group. The incidence of febrile neutropenia did not differ between groups. Multivariate analysis identified the AMR dose was not associated with longer PFS and OS. CONCLUSION: Treatment with AMR between 30 and 35 mg/m2 showed relatively mild hematologic toxicity compared with AMR at 40 mg/m2, without any significant difference in efficacy. Lower dose of AMR for relapsed SCLC could be a promising treatment option.

MET FISH-positive status predicts short progression-free survival and overall survival after gefitinib treatment in lung adenocarcinoma with EGFR mutation.

BACKGROUND: Lung adenocarcinoma patients with EGFR gene mutations have shown a dramatic response to gefitinib. However, drug resistance eventually emerges which limits the mean duration of response. With that in view, we examined the correlations between MET gene status as assessed by fluorescence in situ hybridization (FISH) with overall survival (OS) and progression-free survival (PFS) in adenocarcinoma patients with EGFR gene mutations who had received gefitinib therapy. METHODS: We evaluated 35 lung cancer samples with EGFR mutation from adenocarcinoma patients who had received gefitinib. Gene copy numbers (GCNs) and amplification of MET gene before gefitinib therapy was examined by FISH. MET protein expression was also evaluated by immunohistochemistry (IHC). RESULTS: FISH assessment showed that of the 35 adenocarcinoma samples, 10 patients (29%) exhibited high polysomy (5 copies≦mean MET per cell) and 1 patient (3%) exhibited amplification (2≦MET gene (red)/CEP7q (green) per cell). IHC evaluation of MET protein expression could not confirm MET high polysomy status. The Eleven patients with MET FISH positivity had significantly shorter progression-free survival (PFS) and overall survival (OS) than the 24 patients who were MET FISH-negative (PFS: p = 0.001 and OS: p = 0.03). Median PFS and OS with MET FISH-positivity were 7.6 months and 16.8 months, respectively, whereas PFS and OS with MET FISH-negativity were 15.9 months and 33.0 months, respectively. Univariate analysis revealed that MET FISH-positivity was the most significant independent factor associated with a high risk of progression and death (hazard ratio, 3.83 (p = 0.0008) and 2.25 (p = 0.03), respectively). CONCLUSIONS: Using FISH analysis to detect high polysomy and amplification of MET gene may be useful in predicting shortened PFS and OS after Gefitinib treatment in lung adenocarcinoma. The correlation between MET gene status and clinical outcomes for EGFR-TKI should be further evaluated using large scale samples.

Prognostic Significance of NSCLC and Response to EGFR-TKIs of EGFR-Mutated NSCLC Based on PD-L1 Expression.

BACKGROUND/AIM: Recent clinical trials have shown that immune checkpoint blockades that target either PD-1 or PD-L1 yield remarkable responses in a subgroup of patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: We retrospectively examined, by immunohistochemical analysis, 211 NSCLC samples. Using 32 independent samples, we also evaluated PD-L1 expression in NSCLC patients with EGFR gene mutations treated by EGFR-TKIs. RESULTS: Overall survival of PD-L1-positive stages I-III NSCLC and stage I NSCLC and stages I-III squamous cell carcinoma (SQ) were significantly shorter than those of PD-L1-negative NSCLC (p<0.01 and p=0.02 and p=0.01, respectively). In stage I NSCLC and stages I-III SQ, PD-L1 expression was found to be independent predictor of death after multivariate analysis. Response to EGFR-TKIs was not significantly different between PD-L1-positive and PD-L1-negative NSCLC patients with EGFR mutations. CONCLUSION: PD-L1 expression was a significant independent predictor of poor outcome in NSCLC patients.

Overcoming drug-tolerant cancer cell subpopulations showing AXL activation and epithelial-mesenchymal transition is critical in conquering ALK-positive lung cancer.

Anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) induce a dramatic response in non-small cell lung cancer (NSCLC) patients with the ALK fusion gene. However, acquired resistance to ALK-TKIs remains an inevitable problem. In this study, we aimed to discover novel therapeutic targets to conquer ALK-positive lung cancer. We established three types of ALK-TKI (crizotinib, alectinib and ceritinib)-resistant H2228 NSCLC cell lines by high exposure and stepwise methods. We found these cells showed a loss of ALK signaling, overexpressed AXL with epithelial-mesenchymal transition (EMT), and had cancer stem cell-like (CSC) properties, suggesting drug-tolerant cancer cell subpopulations. Similarly, we demonstrated that TGF-ß1 treated H2228 cells also showed AXL overexpression with EMT features and ALK-TKI resistance. The AXL inhibitor, R428, or HSP90 inhibitor, ganetespib, were effective in reversing ALK-TKI resistance and EMT changes in both ALK-TKI-resistant and TGF-ß1-exposed H2228 cells. Tumor volumes of xenograft mice implanted with established H2228-ceritinib-resistant (H2228-CER) cells were significantly reduced after treatment with ganetespib, or ganetespib in combination with ceritinib. Some ALK-positive NSCLC patients with AXL overexpression showed a poorer response to crizotinib therapy than patients with a low expression of AXL. ALK signaling-independent AXL overexpressed in drug-tolerant cancer cell subpopulations with EMT and CSC features may be commonly involved commonly involved in intrinsic and acquired resistance to ALK-TKIs. This suggests AXL and HSP90 inhibitors may be promising therapeutic drugs to overcome drug-tolerant cancer cell subpopulations in ALK-positive NSCLC patients for the reason that ALK-positive NSCLC cells do not live through ALK-TKI therapy.

Prognostic significance of ABCB1 in stage I lung adenocarcinoma.

Cancer stem cell (CSC) properties have been recently proposed to explain tumor carcinogenesis and multidrug resistance in several human cancers, including non-small cell lung cancer (NSCLC). The present study examined the protein expression of three CSC-associated markers, namely ATP binding cassette subfamily B member 1 (ABCB1), aldehyde dehydrogenase 1 family member A1 (ALDH1A1) and cluster of differentiation (CD) 44, by immunohistochemistry in 194 NSCLC patients who underwent complete resection of NSCLC tumors. The association between the expression of these proteins and patient prognosis was evaluated to clarify the prognostic significance of CSC-associated markers in NSCLC patients. Positive staining for ABCB1 demonstrated a trend toward worse survival compared with negative staining in stage I-III NSCLC. Negative staining for ALDH1 or CD44 exhibited a trend toward worse survival compared with positive staining in stage I-III NSCLC. It was observed that patients with stage I lung adenocarcinoma (ADC) showing positivity for ABCB1 expression had significantly poorer survival than those with negative ABCB1 staining (P=0.03). Furthermore, stage I ADC patients with wild-type epidermal growth factor receptor (EGFR) who exhibited positive staining for ABCB1 had significantly shorter disease-free survival (DFS) compared with patients with negative staining for ABCB1 (P<0.01). Analyses by univariate and multivariate Cox proportional hazards models revealed that ABCB1-positive staining was significantly associated with DFS and was an independent prognostic factor (hazard ratio, 3.49; P<0.05) in these patients. These results suggest that ABCB1 protein expression is useful for predicting prognosis and selecting patients for post-operative therapy in stage I lung ADC patients, particularly those harboring wild-type EGFR.

AXL and GAS6 co-expression in lung adenocarcinoma as a prognostic classifier.

AXL, a receptor tyrosine kinase implicated in cell survival, proliferation, and migration, is also associated with acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor therapy. However, its prognostic significance in lung adenocarcinoma (AD) remains unclear. We therefore evaluated the prognostic significance of the expression of AXL and/or its ligand, growth arrest-specific 6 (GAS6), in completely resected lung AD. We evaluated the relationship between AXL, GAS6, and vimentin expression, as determined by immunohistochemistry (IHC) analysis, with overall survival and disease-free survival in 113 patients with stages I-III lung AD. Protein expression was also assayed using western blot analysis in 10 lung AD cell lines. AXL-positive (AXL+), GAS6-positive (GAS6+), or AXL+/GAS6+ staining was significantly associated with vimentin-positive (vimentin+) expression. AXL+/GAS6+ and vimentin+ showed a negative tendency toward an association with EGFR mutation. AXL+, GAS6+, or AXL+/GAS6+ status significantly correlated with poor overall survival. In stage I cases, AXL+/GAS6+ status significantly correlated with poor overall survival and disease-free survival, especially in cases with wild-type EGFR. In multivariate analysis, AXL/GAS6 classifications in stage I as well as in stages I-III lung AD were found to be independent factors for poor patient outcomes. Unlike lung AD cell lines with mutant EGFR, almost all cells with wild-type EGFR showed AXL and vimentin co-expression as determined by western blotting. AXL+ and GAS6+ expression is relevant to a poor prognosis in resected lung AD patients at stage I. AXL/GAS6 might serve as crucial predictive and prognostic biomarkers and targets to identify individuals at high risk of post-operative death.

Inhibition of ABCB1 Overcomes Cancer Stem Cell-like Properties and Acquired Resistance to MET Inhibitors in Non-Small Cell Lung Cancer.

Patients with non-small cell lung cancer (NSCLC) EGFR mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as major mechanisms of acquired resistance to EGFR-TKI. Therefore, MET inhibitors have recently been used in NSCLC patients in clinical trials. In this study, we tried to identify the mechanism of acquired resistance to MET inhibitors. We analyzed the antitumor effects of two MET inhibitors, PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC-1 cells with MET amplification were the only cells that were sensitive to both MET inhibitors. We established PHA-665752-resistant EBC-1 cells, namely EBC-1R cells. Activation of KRAS, EGFR, and FGFR2 signaling was observed in EBC-1R cells by FISH and receptor tyrosine kinase phosphorylation antibody arrays. EBC-1R cells also showed overexpression of ATP-binding cassette subfamily B member 1 (ABCB1) as well as phosphorylation of MET. EBC-1R cells grew as cell spheres that exhibited cancer stem cell-like (CSC) properties and epithelial-mesenchymal transition (EMT). The level of miR-138 that targeted ABCB1 was decreased in EBC-1R cells. ABCB1 siRNA and the ABCB1 inhibitor elacridar could reduce sphere numbers and suppress EMT. Elacridar could also reverse resistance to PHA-665752 in EBC-1R cells. Our study demonstrated that ABCB1 overexpression, which was associated with CSC properties and EMT, was involved in the acquired resistance to MET inhibitors. Inhibition of ABCB1 might be a novel therapeutic strategy for NSCLC patients with acquired resistance to MET inhibitors.

Significance of osteopontin in the sensitivity of malignant pleural mesothelioma to pemetrexed.

Pemetrexed (PEM) is currently recommended as one of the standard anticancer drugs for malignant pleural mesothelioma (MPM). However, the mechanism of the sensitivity of MPM to PEM remains unclear. We analyzed the antitumor effects of PEM in six MPM cell lines by MTS assay. To identify genes associated with drug sensitivity, we conducted gene expression profiling on the same set of cell lines using GeneChips and pathway analysis. Three cell lines were sensitive to PEM. A total fo 18 transcripts and 14 genes identified by GeneChips were significantly correlated with sensitivity to PEM. Pathway analysis revealed that osteopontin (SPP1/OPN) was an important target in PEM sensitivity. Overexpression of SPP1/OPN was observed in the sensitive cells by quantitative PCR and western blot analysis. Introduction of SPP1/OPN by lentiviral vector significantly enhanced the invasion activities of MPM cells. PEM treatment with SPP1/OPN knockdown inhibited the PEM-induced cell growth-inhibitory effect in PEM-sensitive cells. Expression of SPP1/OPN and AKT phosphorylation significantly decreased after PEM treatment of the PEM-sensitive cells. High immunohistochemical expression of SPP1/OPN was observed in two of three MPM patients who had a partial response to PEM-based chemotherapy. PEM has antitumor effects in MPM cells dependent on SPP1/OPN overexpression resulting in AKT activation. Our results suggest that SPP1 may be used as a single predictive biomarker of the effectiveness of PEM treatment in MPM.