Control of the MYC-eIF4E axis plus mTOR inhibitor treatment in small cell lung cancer.

BACKGROUND: Mammalian target of rapamycin (mTOR) inhibitors have anti-tumor effects against renal cell carcinoma, pancreatic neuroendocrine cancer and breast cancer. In this study, we analyzed the antitumor effects of mTOR inhibitors in small cell lung cancer (SCLC) cells and sought to clarify the mechanism of resistance to mTOR inhibitors. METHODS: We analyzed the antitumor effects of three mTOR inhibitors including everolimus in 7 SCLC cell lines by MTS assay. Gene-chip analysis, receptor tyrosine kinases (RTK) array and Western blotting analysis were performed to identify molecules associated with resistance to everolimus. RESULTS: Only SBC5 cells showed sensitivity to everolimus by MTS assay. We established two everolimus resistant-SBC5 cell lines (SBC5 R1 and SBC5 R10) by continuous exposure to increasing concentrations of everolimus stepwise. SPP1 and MYC were overexpressed in both SBC5 R1 and SBC5 R10 by gene-chip analysis. High expression levels of eukaryotic translation initiation factor 4E (eIF4E) were observed in 5 everolimus-resistant SCLC cells and SBC5 R10 cells by Western blotting. MYC siRNA reduced eIF4E phosphorylation in SBC5 cells, suggesting that MYC directly activates eIF4E by an mTOR-independent bypass pathway. Importantly, after reduction of MYC or eIF4E by siRNAs, the SBC5 parent and two SBC5-resistant cells displayed increased sensitivity to everolimus relative to the siRNA controls. CONCLUSION: These findings suggest that eIF4E has been shown to be an important factor in the resistance to everolimus in SCLC cells. Furthermore, a link between MYC and mTOR-independent eIF4E contribute to the resistance to everolimus in SCLC cells. Control of the MYC-eIF4E axis may be a novel therapeutic strategy for everolimus action in SCLC.

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.

Activity of EGFR-tyrosine kinase and ALK inhibitors for EML4-ALK-rearranged non-small-cell lung cancer harbored coexisting EGFR mutation.

BACKGROUND: The EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) fusion oncogene represents a novel molecular target in a small subset of non-small-cell lung cancers (NSCLCs). The EML4-ALK fusion gene occurs generally in NSCLC without mutations in epidermal growth factor receptor (EGFR) and KRAS. CASE PRESENTATION: We report that a case of EML4-ALK-positive NSCLC with EGFR mutation had a response of stable disease to both an EGFR tyrosine kinase inhibitor (EGFR-TKI) and ALK inhibitor. CONCLUSIONS: We described the first clinical report of a patient with EML4-ALK-positive NSCLC with EGFR mutation that had a response of stable disease to both single-agent EGFR-TKI and ALK inhibitor. EML4-ALK translocation may be associated with resistance to EGFR-TKI, and EGFR signaling may contribute to resistance to ALK inhibitor in EML4-ALK-positive NSCLC.

Apoptosis-inducing activity of the actin-depolymerizing agent aplyronine A and its side-chain derivatives.

Aplyronine A (1) and mycalolide B (2), which are cytotoxic actin-depolymerizing marine macrolides, were revealed to induce apoptosis in human leukemia HL60 cells and human epithelial carcinoma HeLa S(3) cells. Based on these results, actin-depolymerizing compounds were expected to exhibit apoptosis-inducing activity in cancer cells. Compounds 3-6, which were synthesized based on the side-chain structure of aplyronine A, were evaluated for their actin-depolymerizing activities in vitro and cytotoxicities against HL60 cells. The growth-inhibitory activities of 3-6 were well correlated with their actin-depolymerizing activities, and derivative 6 was shown to induce the disruption of actin filaments and apoptosis in HL60 cells. These results suggested that actin-depolymerizing agents 1, 2, and 6-induced apoptosis in HL60 cells may have been due to their actin-depolymerizing activity.

Synthesis of actin-depolymerizing compounds.

The artificial actin-depolymerizing compounds 3-6, based on aplyronine A, an actin-depolymerizing antitumor marine macrolide, were synthesized, and their actin-depolymerizing activities and cytotoxicities were evaluated.

Estimation of postoperative fat absorption using the 13C mixed-triglyceride breath test in children with choledochal cyst.

No previous studies have focused on postoperative fat malabsorption in children with choledochal cyst (CC) who undergo cyst excision and Roux-en-Y (RY) hepatico-jejunostomy (HJ), a combination of procedures that can lead to the non-physiological mixture of food and bile juice. To examine the effect of RYHJ with cholecystectomy on the fat absorption ability of children with CC, we estimated postoperative fat-absorption ability using the carbon 13-labeled mixed triglyceride (13C-MTG) breath test. Twelve postoperative children with CC and 12 normal control children were administered 13C-MTG orally and asked to give breath samples at six time points: once before the 13C-MTG ingestion and at five 60-min intervals postingestion. Fecal chymotrypsin activity and fecal fat excretion were also measured. The delta value of breath 13CO2 at 3, 4, and 5 h after administration and the 5-h cumulative breath 13CO2 were significantly lower in the CC children than in the controls. There were no significant differences in the fecal chymotrypsin activity or fecal fat excretion of the two groups. Conclusion. Occult fat malabsorption occurs in patients with CC after RYHJ, even in the absence of clinical symptoms or abnormal laboratory data.

Choroidal metastasis in a patient with small cell lung cancer discovered during treatment with chemotherapy.

A 56-year-old male patient complaining of productive cough, hoarseness, and fatigue was found to have extensive disease of small cell lung cancer (ED-SCLC), with staging of cT4N3M1(PUL). He was treated with chemotherapy. While undergoing treatment with chemotherapy, he complained of a right visual disturbance, and choroidal metastasis was diagnosed. Because the primary site responded well to chemotherapy alone and the visual disturbance did not worsen, the patient refused radiotherapy to the choroidal metastasis. Two months after the first diagnosis of the choroidal metastasis, while he was receiving the first treatment regimen for SCLC, the visual disturbance suddenly worsened; emergent radiotherapy was started, with a total dose of 40 Gy, given as 2.0 Gy/fraction per day. The visual disturbance never improved, and the patient lost 80% of his right visual field. Within 6 months of diagnosis, the patient became blind in his right eye. The patient died of septic shock related to treatment received during his third chemotherapy regimen. Choroidal metastasis is very rare with extraocular malignant tumors, though it is common with intraocular malignant tumors. Choroidal metastasis secondary to SCLC has a poor prognosis, but in order to maintain quality of life during the patients' remaining lifespan, aggressive treatment would appear appropriate for these patients, because SCLC is a chemo-sensitive cancer.

MiR-134/487b/655 cluster regulates TGF-ß-induced epithelial-mesenchymal transition and drug resistance to gefitinib by targeting MAGI2 in lung adenocarcinoma cells.

Epithelial-mesenchymal transition (EMT) has recently been recognized as a key element of cell invasion, migration, metastasis, and drug resistance in several types of cancer, including non-small cell lung cancer (NSCLC). Our aim was to clarify microRNA (miRNA)-related mechanisms underlying EMT followed by acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) in NSCLC. miRNA expression profiles were examined before and after transforming growth factor ß1 (TGF-ß1) exposure in four human adenocarcinoma cell lines with or without EMT. Correlation between expressions of EMT-related miRNAs and resistance to EGFR-TKI gefitinib was evaluated. miRNA array and real-time quantitative reverse transcription PCR (qRT-PCR) revealed that TGF-ß1 significantly induced overexpression of miR-134, miR-487b, and miR-655, which belong to the same cluster located on chromosome 14q32, in lung adenocarcinoma cells with EMT. MAGI2 (membrane-associated guanylate kinase, WW, and PDZ domain-containing protein 2), a predicted target of these miRNAs and a scaffold protein required for PTEN, was diminished in A549 cells with EMT after the TGF-ß1 stimulation. Overexpression of miR-134 and miR-487b promoted the EMT phenomenon and affected the drug resistance to gefitinib, whereas knockdown of these miRNAs inhibited the EMT process and reversed TGF-ß1-induced resistance to gefitinib. Our study demonstrated that the miR-134/487b/655 cluster contributed to the TGF-ß1-induced EMT phenomenon and affected the resistance to gefitinib by directly targeting MAGI2, in which suppression subsequently caused loss of PTEN stability in lung cancer cells. The miR-134/miR-487b/miR-655 cluster may be a new therapeutic target in patients with advanced lung adenocarcinoma, depending on the EMT phenomenon.

Bevacizumab plus chemotherapy for advanced non-squamous non-small-cell lung cancer with malignant pleural effusion.

PURPOSE: The presence of malignant pleural effusion (MPE) indicates a poorer prognosis for patients with non-small-cell lung cancer (NSCLC) and impairs their quality of life. Because vascular endothelial growth factor (VEGF) is the key mediator MPE production, we evaluated the efficacy and safety of chemotherapy plus bevacizumab, an anti-VEGF antibody, in non-squamous NSCLC patients with MPE, especially regarding the control of pleural effusions. METHODS: From November 1, 2009 to September 30, 2011, medical charts of 13 consecutive patients with MPE who received bevacizumab plus chemotherapy as the initial or secondary treatment were retrospectively analyzed. RESULTS: Of the 13 patients, 6 did not undergo pleurodesis, 3 were unsuccessfully treated by pleurodesis, 2 had encapsulated pleural effusion, and 2 had no re-expansion of the lung. Twelve patients (92.3 %) achieved MPE control lasting >8 weeks following bevacizumab plus chemotherapy. Five of 10 patients with measurable lesions had confirmed partial responses. Of 3 patients without measurable lesions, one had confirmed CR. Median progression-free survival time without re-accumulation of MPE was 312 days. Grade 3 or 4 neutropenia, thrombocytopenia, hypertension, or proteinuria was observed in 2, 2, 1, or 1 patient, respectively. CONCLUSIONS: This is the first study to report that bevacizumab plus chemotherapy is highly effective for the management of MPE in non-squamous NSCLC patients. Prospective clinical trials are warranted to investigate the efficacy of bevacizumab for MPE.

MiR-23a regulates TGF-ß-induced epithelial-mesenchymal transition by targeting E-cadherin in lung cancer cells.

Transforming growth factor-ß (TGF-ß)-induced epithelial-mesenchymal transition (EMT) has been shown to be related to the pathogenesis of various diseases including lung cancer. Recently, microRNAs (miRNA) have been recognized as a new class of genes involved in human tumorigenesis. MiR-23a/24/27a is a miRNA cluster located in chromosome 19p13.12, which can function as an oncogene in several human cancers. In this study, we analyzed miR-23a/24/27a expression in 10 non-small cell cancer (NSCLC) cell lines by real-time PCR analysis. Correlation between expression of these miRNAs and TGF-ß/Smad signaling was evaluated. We found that miR-23a could be regulated by TGF-ß1 in a Smad-dependent manner in A549 lung adenocarcinoma cells showing the EMT phenomenon. Knockdown of miR-23a partially restored E-cadherin expression under conditions of TGF-ß1 stimulation. In contrast, overexpression of miR-23a could suppress E-cadherin expression and stimulate EMT. Furthermore, A549 cells with overexpressed miR-23a were more resistant to gefitinib compared to the parental cells. These findings suggest that miR-23a regulates TGF-ß-induced EMT by targeting E-cadherin in lung cancer cells and may be useful as a new therapeutic target in NSCLC.

The feasibility study of Carboplatin plus Etoposide for advanced small cell lung cancer with idiopathic interstitial pneumonias.

BACKGROUND: Idiopathic interstitial pneumonias (IIPs) are among the most common complications in patients with lung cancer. In such patients with cancer, the most serious expression of toxicity in Japan is acute exacerbation of IIPs caused by anticancer treatment. Nevertheless, there has been no consensus and no evidence presented, regarding optimal treatment for advanced lung cancer with IIP. PATIENTS AND METHODS: Chemotherapy-naive patients with advanced small cell lung cancer (SCLC) with IIP who were ineligible for curative radiotherapy were enrolled. Patients received carboplatin every 21 days at a dose of area under the curve 6.0 on day 1 and etoposide at a dose of 100 mg/m on days 1 to 3. RESULTS: Between July 2002 and October 2008, 17 patients with SCLC with IIP, including 14 men, eight of whom were diagnosed with idiopathic pulmonary fibrosis, were enrolled and treated for a mean of 3.5 cycles of carboplatin plus etoposide. One patient (5.9%; 95% confidence interval, 0-18.4%) with clinically confirmed idiopathic pulmonary fibrosis had acute exacerbation of IIPs associated with the treatment. The overall response rate was 88.2%. The median progression-free survival, median survival time, and 1-year survival rate were 5.5 months, 8.7 months, and 29.4%, respectively. CONCLUSION: This is the first report indicating that patients with advanced SCLC with IIPs may benefit from chemotherapy. Patients with advanced SCLC with IIP treated with etoposide and carboplatin combination chemotherapy gain benefits, with safety equivalent to that seen in patients without IIP. The results from this study would support, on ethical grounds, the conduct of a large-scale study to evaluate this regimen.

HSP27 modulates epithelial to mesenchymal transition of lung cancer cells in a Smad-independent manner.

Epithelial to mesenchymal transition (EMT) is induced by transforming growth factor-ß1 (TGF-ß1) and is a crucial event for cancer cells to acquire invasive and metastatic phenotypes. However, the signals that induce EMT in cancer cells have yet to be adequately defined. In this study, a proteomic investigation was performed to understand the signaling pathway of the EMT of lung cancer using two-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry. The protein expression profiles of A549 were compared to those of A549 cells treated with TGF-ß1. Of more than 2,000 protein spots shown by 2D-DIGE, 53 were found to be up- or down-regulated upon induction with TGF-ß1. In the 53 protein spots, the protein level of heat shock protein (HSP) 27 was found to increase significantly. HSP27 protein was higher in two different lung cancer cell lines, demonstrating the EMT phenomenon with TGF-ß1. Notably, the silencing of HSP27 enhanced spindle integration, resulting in an additive effect with TGF-ß1-induced EMT. Furthermore, the TGF-ß1-induced HSP27 increase was not affected by the suppression of Smad2 and Smad3 in A549 cells. These results suggest that HSP27 was involved in TGF-ß1-induced EMT in a Smad-independent manner in lung cancer cells and may provide an effective clinical strategy in lung cancer patients whose tumors are dependent on TGF-ß1-induced EMT.

Biselyngbyaside, a macrolide glycoside from the marine cyanobacterium Lyngbya sp.

Bioassay-guided fractionation of the cytotoxic constituents of the marine cyanobacterium Lyngbya sp. led to the isolation of biselyngbyaside (1), a new 18-membered macrolide glycoside. The structure of 1 was established by spectroscopic analysis including 2D-NMR techniques and by synthetic studies. Biselyngbyaside (1) exhibits broad-spectrum cytotoxicity in a human tumor cell line panel.

Retrospective analysis of efficacy and safety of amrubicin in refractory and relapsed small-cell lung cancer.

BACKGROUND: Amrubicin, a totally synthetic 9-aminoanthracycline, was evaluated retrospectively for the treatment of refractory and relapsed small-cell lung cancer (SCLC). METHODS: Retrospective analysis was performed in 32 patients. Amrubicin was infused over 5 min on days 1-3, with courses repeated at 3- or 4-week intervals. Amrubicin was given at a dose of 45 mg/m(2) per day, 40 mg/m(2) per day, 35 mg/m(2) per day, 30 mg/m(2) per day, or 25 mg/m(2) per day depending on medical conditions (patients' age and performance status [PS]), and the dose was modulated according to myelosuppression. RESULTS: The median number of treatment cycles was 3 (range, 1-6). Seventeen patients (53.1%) had a partial response. Median progression-free survival time for all patients was 96 days, and median survival time was 166 days. Grade 3 or 4 hematologic toxicities comprised neutropenia (78.1%), anemia (65.6%), and thrombocytopenia (50.0%). Febrile neutropenia was observed in 8 patients (25.0%). Nonhematologic toxicities were mild. Treatment-related death was observed in 1 patient. CONCLUSION: Treatment with amrubicin appeared effective in SCLC patients previously treated with chemotherapy, although it was not necessarily safe, because of myelosuppression. Further research is warranted to investigate amrubicin treatment for patients with SCLC.