Hironori Ashinuma

Antiproliferative action of metformin in human lung cancer cell lines

The oral antidiabetic agent metformin has anticancer properties, probably via adenosine monophosphate-activated protein kinase activation. In the present study, growth inhibition was assessed by a clonogenic and by a cell survival assay, apoptosis induction was assessed by Hoechst staining and caspase activities and cell cycle alteration after exposure to metformin, and the interaction of metformin with cisplatin in vitro were elucidated in four human lung cancer cell lines representing squamous, adeno-, large cell and small cell carcinoma. Clonogenicity and cell proliferation were inhibited by metformin in all the cell lines examined. This inhibitory effect was not specific to cancer cells because it was also observed in a non-transformed human mesothelial cell line and in mouse fibroblast cell lines. Inhibition of clonogenicity was observed only when the cells were exposed to metformin for a long period, (10 days) and the surviving fraction, obtained after inhibiting proliferation by increasing the dose, reached a plateau at approximately 0.1-0.3, indicating the cytostatic characteristics of metformin. Metformin induced significant apoptosis only in the small cell carcinoma cell line. A tendency of cell cycle accumulation at the G0/G1 phase was observed in all four cell lines. Cisplatin, in a dose-dependent manner, severely antagonized the growth inhibitory effect of metformin, and even reversed the effect in three cell lines but not in the adenocarcinoma cell line. The present data obtained using various histological types of human lung cancer cell lines in vitro illustrate the cytostatic nature of metformin and its cytoprotective properties against cisplatin.

Endobronchial ultrasonography for positron emission tomography and computed tomography-negative lymph node staging in non-small cell lung cancer.

BACKGROUND Integrated positron emission tomography (PET) with computed tomography (CT) is a useful modality to investigate lymph node metastases for non-small cell lung cancer, but is less sensitive for normal-sized lymph nodes. We sometimes encounter cases with radiologically normal lymph nodes and unsuspected mediastinal metastases detected by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). However, few studies have investigated staging in patients with radiologically normal mediastina, and the accuracy of EBUS-TBNA staging for radiologically normal mediastina and hila is unclear. METHODS This study was a retrospective, single-institution review of a prospectively maintained database at Chiba Cancer Center between May 1, 2008, and September 1, 2013. We analyzed 113 non-small cell lung cancer patients with both CT-negative and PET/CT-negative lymph nodes (N0) in preoperative nodal staging performed by EBUS-TBNA. After preoperative staging was performed, patients with either N0 or N1 clinical staging underwent surgery. Final N factors were determined by mediastinal lymphadenectomy. RESULTS In our study, the overall rate of N2 disease was 17.6% (20 of 113). For nodal staging by EBUS-TBNA, the sensitivity, specificity, negative predictive value, and diagnostic accuracy were 35.0% (7 of 20), 100% (93 of 93), 87.7% (93 of 106), and 88.4% (100 of 113), respectively. There were no severe complications from EBUS-TBNA staging. CONCLUSIONS The overall rate of unsuspected N2 was not low. EBUS-TBNA was accurate and feasible for preoperative mediastinal nodal staging of non-small cell lung cancer with both CT-negative and PET/CT-negative lymph nodes. The sensitivity of EBUS-TBNA for radiologically normal mediastina and hila was low. Further investigations are required.

High CC chemokine receptor 7 expression improves postoperative prognosis of lung adenocarcinoma patients

Background:Chemokines and chemokine receptors not only have significant roles in cancer metastasis and tumorigenesis but also act as antitumour agents. The interaction between the Crk-like adaptor protein (CrkL), which is encoded by the CRKL gene, and non-receptor tyrosine kinase c-ABL is reported to transform many cells into malignant cells. We examined the effects of CC chemokine receptor 7 (CCR7), CCR7 ligands and CrkL and c-ABL in lung adenocarcinoma.Methods:One hundred and twenty patients with lung adenocarcinoma were included in this historical cohort analysis. We examined CCR7 and CCR7 ligands and CrkL and c-ABL mRNA expressions in surgically resected lung adenocarcinoma specimens and evaluated their contribution to prognosis, and the relationship with epidermal growth factor receptor (EGFR) and TP53 mutations.Results:High CCR7 mRNA expressions indicated better prognoses than those of the groups with low CCR7 mRNA expressions (P=0.007, HR=2.00, 95% CI of ratio: 1.22 –3.31). In lung adenocarcinoma, CrkL and c-ABL mRNAs were related to CCR7 mRNA expression (P<0.0001). CrkL and c-ABL mRNA expressions were influenced by EGFR mutations. A high expression of CCL19 was a good prognostic factor of lung adenocarcinoma.Conclusion:We propose that CCR7 and CCL19 are clinically good prognostic factors and that CCR7 is strongly related to CrkL and c-ABL kinase mRNA expression in lung adenocarcinoma.

Effect of metformin on residual cells after chemotherapy in a human lung adenocarcinoma cell line

Cancer chemotherapy, including molecular targeted therapy, has major limitations because it does not kill all the cancer cells; the residual cells survive until they acquire chemoresistance. In the present study, the combined effects of metformin and gefitinib were examined in vivo in a mouse xenograft model, inoculated with a human lung adenocarcinoma cell line that possesses an activating epidermal growth factor receptor mutation. The mechanism of the interaction was further elucidated in vitro. Metformin did not suppress the growth of already established tumors, nor did metformin augment tumor shrinkage by gefitinib. However, metformin significantly suppressed the regrowth of the tumor after effective treatment with gefitinib, suggesting the specific effect of metformin on the residual cells. Cytotoxicity of metformin was characterized by the absence of apoptosis induction and unremarkable cell cycle shift in vitro. The residual cell population after treatment with gefitinib was characterized by enriched cells with high expression of CD133 and CD24. Metformin was still effective on this specific cell population. Targeting residual cells after chemotherapy may represent an effective novel strategy for the treatment of cancer. Elucidating the mechanism of metformin cytotoxicity provides insights into future development of anticancer therapeutics.

Interaction and cross-resistance of cisplatin and pemetrexed in malignant pleural mesothelioma cell lines

Although cisplatin and pemetrexed are key drugs in the treatment of malignant pleural mesothelioma, their drug-drug interactions, cross-resistance and resistance mechanisms in malignant pleural mesothelioma are not well understood. In the present study, the interaction of these 2 agents was determined by clonogenic assays followed by isobologram analysis of 4 human malignant pleural mesothelioma cell lines. The cell lines were exposed to the agents using a stepwise dose-escalation method to establish drug-resistant sublines. Thymidylate synthase mRNA expression was evaluated in the drug-resistant sublines. As a consequence, cisplatin and pemetrexed had synergistic effects in 3 cell lines and an additive effect in the fourth cell line. The former 3 cell lines showed similar pemetrexed sensitivity in the parental cells and their cisplatin-resistant sublines, whereas the fourth cell line exhibited cross-resistance. In contrast, cisplatin had diverse effects on pemetrexed-resistant sublines. High thymidylate synthase expression did not correlate with natural pemetrexed resistance. Elevated thymidylate synthase expression correlated with acquired pemetrexed resistance in 2 sublines. In conclusion, cisplatin and pemetrexed showed synergistic activity and no cross-resistance in 3 of the 4 malignant pleural mesothelioma cell lines, suggesting the clinical relevance of their combination in chemotherapy. Thymidylate synthase expression did not necessarily correlate with pemetrexed resistance. The information together with the experimental model presented here would be useful for further investigating therapeutic targets of malignant mesothelioma.

Endobronchial Ultrasound-guided Transbronchial Needle Aspiration in a Patient with Pericardial Mesothelioma

Pericardial mesothelioma is a very rare pericardial tumor. Diagnosing pericardial disease can be challenging, and obtaining an antemortem diagnosis of pericardial mesothelioma is particularly difficult. We herein report the case of a 60-year-old man with pericardial mesothelioma diagnosed on endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Chest computed tomography showed a mass surrounding the pericardium, and EBUS-TBNA of the right inferior paratracheal and subcarinal stations was consequently performed. No uptake was noted on (18)F-fluorodeoxy glucose positron emission tomography, other than in the pericardial mass. The results of histological and immunohistochemical examinations indicated the features of malignant mesothelioma. We therefore diagnosed the patient with pericardial mesothelioma, which was subsequently confirmed at autopsy.

Successful Diagnosis of a Thymoma by Endobronchial Ultrasound-guided Transbronchial Needle Aspiration: A Report of Two Cases.

We herein report two cases of thymomas diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). In both cases, the tumor was adjacent to the central airway. Therefore, we attempted to perform EBUS-TBNA in order to obtain specimens for a histopathological examination, which resulted in a diagnosis of thymoma. In one case, surgical resection was conducted and the histological evaluation of the resected specimen confirmed thymoma type AB, consistent with the histology from the EBUS-TBNA specimen. As a safe and minimally invasive procedure, EBUS-TBNA may be considered for the diagnosis of mediastinal tumors, including thymoma.

Ceritinib Treatment for Carcinomatous Meningitis with a Secondary Mutation at I1171T in Anaplastic Lymphoma Kinase

The mechanisms underlying anaplastic lymphoma kinase (ALK) resistance have not been well investigated in clinical practice. We herein report the case of a lung cancer patient with carcinomatous meningitis who had an ALK I1171T resistance mutation revealed by direct DNA sequencing of the cerebrospinal fluid after treatment with cytotoxic chemotherapy, crizotinib, and alectinib. I1171T is considered to be sensitive to ceritinib. Although ceritinib was not effective initially, we chose ceritinib again after whole-brain radiotherapy and ventriculoperitoneal shunting. Although the response duration was short, spinal magnetic resonance imaging revealed a marked response. The identification of an acquired ALK resistance mutation will aid in choosing the optimum sequence therapy.

Retrospective analysis of lung cancer patients treated with supportive care alone

BackgroundIt is not uncommon for patients with lung cancer to receive supportive care alone. However, the clinical characteristics of these patients have not been fully studied. We conducted a retrospective study to identify the clinical characteristics of definitive lung cancer patients treated with supportive care alone.MethodsWe retrospectively analyzed the percentage of and reasons for definitive lung cancer patients treated with supportive care alone at a regional cancer center. We also investigated the histological diagnostic approaches, palliative therapy types, primary treatment locations after hospital consultation, and places of death.ResultsA total of 1,223 patients were histologically diagnosed as having lung cancer between 2011 and 2014. Of these, 160 (13%) patients were treated with supportive care alone. The primary reason for treatment with supportive care alone was a poor performance status (PS) in almost half of the patients. Overall, 40% of the patients received supportive care at home, and 17% were admitted to a palliative care unit (PCU). Death occurred at home for 17% of the patients and in the PCU for 42% of the patients.ConclusionThis study revealed that 13% of histologically proven lung cancer patients were treated with supportive care alone, mostly because of a poor PS. Only 40% of these patients received home care, suggesting the need for a more accessible home care system for patients and their families.

P2-18-2SAFETY AND EFFICACY OF BEVACIZUMAB-CONTAINING CHEMOTHERAPY IN NSCLC PATIENTS WITH BRAIN METASTASES

Abstract Background: Prior to 2012, bevacizumab was contraindicated for patients with brain metastases in Japan due to concerns about cerebral hemorrhage. The package insert changed in 2012 to allow careful administration of bevacizumab; however, we still have insufficient data describing the safety and efficacy of bevacizumab-containing chemotherapy. Because bevacizumab may be effective in the treatment of edema associated with brain metastases and radiation necrosis, it may have additional clinical uses. Methods: We retrospectively evaluated non-small cell lung cancer (NSCLC) patients with brain metastases who had received chemotherapy containing bevacizumab at Chiba Cancer Center between April 2012 and December 2013. Results: Thirty patients were eligible for participation in this study. Of the patients in this study, 15 were men, and 15 were women; patients had a median age of 62.5 years, and all except one had histological adenocarcinoma. Surgery, stereotactic radiosurgery, whole brain radiation, and other therapies were performed in 9, 13, 2, and 1 patients, respectively; 5 patients were not treated. Additionally, 26, 1, 2, and 1 patients received the following chemotherapies: CBDCA + PTX + BEV, CDDP + PEM + BEV, PEM + BEV, or BEV monotherapy, respectively. RECIST classifications of brain metastases were complete response in 2 patients, partial response in 7 patients, stable disease in 11 patients, progressive disease in 1 patients, and NE in 9 patients. Grade 3 adverse events included sensory neuropathy in 1 patient, epileptic seizure in 1 patient, dysbasia in 1 patient, viral encephalitis in 1 patient, febril neutropenia in 1 patient, and subcutaneous abscess of the buttocks in 1 patient. Grade 4 epileptic seizure was occurred in 1 patient. There were no cerebral hemorrhage. Conclusion: Bevacizumab did not increase toxicities in patients with brain metastases and appeared to be effective in the treatment of NSCLC patients with brain metastases.