Shingo Matsumoto

Prevalence and specificity of LKB1 genetic alterations in lung cancers.

Germline LKB1 mutations cause Peutz–Jeghers syndrome, a hereditary disorder that predisposes to gastrointestinal hamartomatous polyposis and several types of malignant tumors. Somatic LKB1 alterations are rare in sporadic cancers, however, a few reports showed the presence of somatic alterations in a considerable fraction of lung cancers. To determine the prevalence and the specificity of LKB1 alterations in lung cancers, we examined a large number of lung cancer cell lines and lung adenocarcinoma (AdC) specimens for the alterations. LKB1 genetic alterations were frequently detected in the cell lines (21/70, 30%), especially in non-small cell lung cancers (NSCLCs) (20/51, 39%), and were significantly more frequent in cell lines with KRAS mutations. Point mutations were detected only in AdCs and large cell carcinomas, whereas homozygous deletions were detected in all histological types of lung cancer. Among lung AdC specimens, LKB1 mutations were found in seven (8%) of 91 male smokers but in none of 64 females and/or nonsmokers, and were significantly more frequent in poorly differentiated tumors. The difference in the frequency of LKB1 alterations between cell lines and tumor specimens was likely to be owing to masking of deletions by the contamination of noncancerous cells in the tumor specimens. These results indicate that somatic LKB1 genetic alterations preferentially occur in a subset of poorly differentiated lung AdCs that appear to correlate with smoking males.

Frequent EGFR mutations in brain metastases of lung adenocarcinoma.

Lung adenocarcinomas often metastasize to the brain, and the prognosis of patients with brain metastases is still very poor. The epidermal growth factor receptor (EGFR) gene is mutated in a considerable fraction of primary lung adenocarcinomas, in particular those with drastic response to EGFR tyrosine kinase inhibitors. The present study was designed to elucidate the prevalence of EGFR mutations in brain metastases and the timing of their occurrence during cancer progression. EGFR mutations were detected in 12 of 19 metastatic lung adenocarcinomas to the brain (63%). This frequency was higher than those in previous studies for EGFR mutations at various stages of lung adenocarcinoma in East Asia, including Japan (i.e., 20–55%). In 6 cases with EGFR mutations, the corresponding primary lung tumors were also examined for the mutations, and in all of them, the same types of EGFR mutations were detected also in the primary tumors. In 2 of them, second metastatic brain tumors in addition to the first ones were also available for analysis, and the same types of EGFR mutations were detected in both the first and second ones in both cases. These results indicate that EGFR mutations are present frequently in brain metastases and occur preceding brain metastasis. These findings will be highly informative for treatment of metastatic lung adenocarcinoma to the brain.

Frequent EGFR mutations in noninvasive bronchioloalveolar carcinoma.

Mutations of the epidermal growth factor receptor gene (EGFR) have been reported to be present in a considerable fraction of lung adenocarcinomas showing dramatic response to EGFR tyrosine kinase inhibitors. To clarify pathogenic significance of the mutations for the development of lung adenocarcinoma, we investigated stage I lung adenocarcinomas for the mutations. First, 107 cases of macrodissected stage I adenocarcinomas were examined for mutations in exons 18–21 of the EGFR gene. EGFR mutations were detected in 36 of the 107 cases (34%). In particular, among the stage I cases, the mutations were detected in 17 of 42 small‐sized adenocarcinomas (≤2 cm in diameter) (40%), including 7 of 11 noninvasive bronchioloalveolar carcinomas (BACs) (64%) and 7 of 25 invasive adenocarcinomas with BAC components (28%). Second, 26 cases of laser capture microdissected small‐sized adenocarcinomas, including 9 cases in the first analysis, were examined for the mutations. Reanalysis of microdissected materials in the 9 cases identified the mutations in 2 more adenocarcinomas with BAC components. Moreover, in the analysis of the other 17 microdissected materials, EGFR mutations were detected in 7 of 12 BACs (58%) and in 3 of 5 adenocarcinomas with BAC components (60%). EGFR mutations are present frequently in BACs, and are thus likely to be a critical genetic alteration for the formation of noninvasive lung adenocarcinoma.

Sulindac sulfide and caffeic acid phenethyl ester suppress the motility of lung adenocarcinoma cells promoted by transforming growth factor-β through Akt inhibition

Abstract Cell migration is essential for invasive and metastatic phenotypes of cancer cells. Potential chemopreventive agents of cancer—sulindac sulfide, caffeic acid phenethyl ester (CAPE), curcumin, and (+)-catechin—have been reported to interfere with several types of intracellular signaling. In this study, we examined the effects of these agents on transforming growth factor-β(TGF-β)-induced motility and Akt phosphorylation in A549 cells. Judged by gold particle phagokinesis assay, sulindac sulfide, CAPE, and curcumin suppressed the motility of A549 cells promoted by TGF-β. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase(PI3K)/Akt signaling, also suppressed TGF-β-induced motility and Akt phosphorylation. Sulindac sulfide and CAPE, but not curcumin, suppressed TGF-β-induced Akt phosphorylation. We conclude that sulindac sulfide and CAPE suppress the motility promoted by TGF-β in lung adenocarcinoma cells through the suppression of Akt. Our observations raise the possibility that these agents, except for (+)-catechin, can be applied not only as chemopreventive agents but also as anti-metastatic therapy.

Phase II Study of Weekly Paclitaxel in Patients with Non-Small Cell Lung Cancer Who Have Failed Previous Treatments

Objective: New effective therapy is desirable for patients with non-small cell lung cancer (NSCLC) who have failed previous treatments. Fractionated administration of paclitaxel may be less toxic and more active against NSCLC. The aim of this study was to evaluate the activity and toxicity of weekly paclitaxel therapy for NSCLC in a second-line setting. Methods: Patients with pathological or cytological diagnosis of NSCLC, measurable lesions, and one or more prior therapies were enrolled. We administered weekly infusions of 80 mg/m2 paclitaxel 3 times in a 4-week cycle. In the absence of progressive disease or intolerable toxicity, each patient was treated for a minimum of 4 cycles. Results: Of 39 patients enrolled, 1 patient achieved complete response and 11 patients achieved partial response (response rate, 31%: 95% confidence interval, 17–48%). The median survival time was 43 weeks (range, 7–128 weeks). Grade 3 or 4 leukopenia occurred in only 7 patients (18%). Neurotoxicity was the most frequent adverse effect (grades 1 and 2.26 and 5%, respectively). Although all patients recovered rapidly with corticosteroid treatment, drug-induced pneumonitis was observed in 3 patients (8%). Conclusion: Low-dose weekly paclitaxel is a promising therapy with high effectiveness for advanced NSCLC in patients with NSCLC who have failed previous treatments.

Phase II Trial of Weekly Paclitaxel in Previously Untreated Advanced Non-Small-Cell Lung Cancer

Objective: New effective therapy is desirable for outpatients with advanced non-small-cell lung cancer (NSCLC). Fractionated administration of paclitaxel may be less toxic and more active against NSCLC. The aim of this study was to evaluate the activity and toxicity of weekly paclitaxel therapy for chemotherapy-naive NSCLC. Methods: Patients with pathological or cytological diagnosis of NSCLC, measurable lesions, and no prior therapy were enrolled. We administered weekly infusions of 80 mg/m2 paclitaxel 3 times in a 4-week cycle. In the absence of progressive disease or intolerable toxicity, we treated each patient for a minimum of four cycles. Results: Of 35 patients enrolled, 17 patients achieved partial response, although no complete responses were observed (response rate 49%; 95% confidence interval 32–66%). The median survival time was 55 weeks (range 6–93 weeks). Grade 3 or 4 leukopenia occurred in only 1 patient (3%). Neurotoxicity was the most frequent adverse effect (grades 1 and 2, 26 and 3%, respectively). Serious toxicity, observed in 2 patients (6%), was interstitial pneumonia, and 1 patient died from sequela. Conclusion: Low-dose weekly paclitaxel is a promising therapy for advanced NSCLC with high effectiveness and low toxicity.

Diagnostic and prognostic impact of serum‐soluble UL16‐binding protein 2 in lung cancer patients

UL16‐binding protein 2 (ULBP2) is one of the ligands for NKG2D (NKG2DL). ULBP2 expression is induced in transformed cells and is recognized by immune effector cells via the activating NKG2D immunoreceptor. Soluble forms of NKG2DL have been reported in the serum of patients with several types of cancer. The present study investigated the diagnostic and prognostic significance of serum‐soluble ULBP2 (sULBP2) in lung cancer patients. We used flow cytometry to evaluate the surface expression of NKG2DL by various lung cancer cells, while sULBP2 was measured using our original ELISA. In addition, the immunological effect of sULBP2 on peripheral blood mononuclear cells (PBMC) was examined by the 51Cr release assay. We found that ULBP2 was highly expressed and that the sULBP2 level was elevated in supernatants of cultured non‐small‐cell lung cancer (NSCLC) cells as well as in the serum of NSCLC patients. ULBP2 levels were especially high in squamous cell carcinoma (SQ) patients. Clinical stage IIIB and IV NSCLC patients with a sULBP2 level ≥8.7 pg/mL showed significantly shorter survival than patients with sULBP2 <8.7 pg/mL. In multivariate analysis, a sULBP2 level ≥8.7 pg/mL (hazard ratio [HR], 2.13; P = 0.038) and clinical stage IV (HR, 2.65; P = 0.019) were independent determinants of a poor outcome. As a possible mechanism, we demonstrated that sULBP2 directly suppresses the cytolytic activity of PBMC. In conclusion, ULBP2 is the most significant NKG2DL for lung cancer, and sULBP2 is useful in the diagnosis of SQ and as a prognostic indicator for patients with advanced NSCLC. (Cancer Sci, doi: 10.1111/j.1349‐7006.2012.02330.x, 2012)

Synergistic cell growth inhibition by the combination of amrubicin and Akt-suppressing agents in K-ras mutation-harboring lung adenocarcinoma cells: Implication of EGFR tyrosine kinase inhibitors

Previously we showed that Akt-suppressing agents, combined with amrubicin, synergistically inhibited the growth of small cell lung cancer cells. The combined effects of chemotherapeutic agents and Akt-suppressing agents, including epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, were evaluated in A549 lung adenocarcinoma cells harboring K-ras mutation and wild-type EGFR. Only amrubicin and not other chemotherapeutics (cisplatin, pemetrexed and paclitaxel) synergistically inhibited cell growth when combined with an Akt inhibitor, LY294002. The combination of amrubicin and LY294002 enhanced Annexinxa0V binding to cells. A non-specific tyrosine kinase inhibitor, genistein, suppressed Akt and showed synergistic interaction in combination with amrubicin. Two EGFR tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, suppressed Akt activity at clinically achievable concentrations and demonstrated synergism when combined with amrubicin. The suppression of K-ras expression by siRNA interfered with this synergism and inhibited both EGFR and Akt activity in A549 cells. In Ma10 cells, which harbor wild-type EGFR and K-ras, EGFR-TKIs neither suppressed Akt activity nor exhibited such synergism when combined with amrubicin. We concluded that the synergism by the combination of EGFR-TKI and amrubicin is attributable, at least partially, to K-ras mutation in A549 cells. The combination of EGFR-TKI and amrubicin may be a promising treatment for lung cancer with wild-type EGFR and K-ras mutation.

UFT plus vinorelbine in advanced non-small cell lung cancer: a phase I and an elderly patient-directed phase II study.

Purpose: The combination of tegafur-uracil (UFT) with vinorelbine has provided synergistic activity against non-small cell lung cancer (NSCLC) in experimental models. The recommended dose of UFT in combination with vinorelbine in NSCLC was determined in a phase I study. The phase II study evaluated efficacy and tolerability of this combination in elderly patients. Methods: Vinorelbine was infused on days 1 and 8, and UFT was administered twice daily on days 2 to 6 and days 9 to 13 of a 3-week cycle. UFT and vinorelbine were increased during the phase I study from 400 to 600 mg/d and 20 to 25 mg/m2, respectively, in 12 patients. In the phase II portion, previously untreated elderly patients were treated with 600 mg/d UFT and 20 mg/m2 vinorelbine. Results: At the dose level of 600 mg/d UFT and 25 mg/m2 vinorelbine, dose-limiting toxicity of neutropenia or neutropenic fever was observed in two of three patients, determining the recommended dose of 600 mg/d UFT and 20 mg/m2 vinorelbine. In 30 evaluable elderly patients of the phase II study, the response rate was 27% (8/30). The median survival and progression-free survival time was 11.8 (range 2.7–34.8) and 5.0 (range 0.5–32.5) months, respectively. Grade 3 or grade 4 neutropenia and grade 3 anemia occurred in 40% and 7% of phase II patients, respectively. Gastrointestinal toxicity was frequent but mild. As the most serious toxicity, pneumonitis was observed in three patients. Conclusion: This combination of UFT and vinorelbine is both feasible and active in the treatment of elderly patients with advanced NSCLC.

Development of fever following first administration of zoledronate as a prognostic factor in advanced non‑small cell lung cancer patients with bone metastases

Nitrogen-containing bisphosphonates (N-BPs), which are usually used for the treatment of advanced cancer with bone metastasis, occasionally cause fever following the first administration. However, it is unclear as to how the development of fever following the first administration of N-BP is associated with clinical outcome. The aim of the present study was to determine the prognostic value of the development of fever following the first administration of N-BP in advanced non-small cell lung cancer patients with bone metastases. The present study reviewed the data of 46 patients with advanced non-small cell lung cancer who were administered zoledronate (ZOL), an N-BP, for bone metastasis, between March 2009 and March 2011 in the Department of Medical Respirology at Tottori University Hospital. Clinicopathological factors were evaluated using univariate and multivariate analyses, and these factors were compared between the fever and non-fever groups. Of the 46 patients, 15 (32.6%) developed fever following the first administration of ZOL. No significant differences were observed in the clinicopathological characteristics between the two groups. The overall survival in the fever group was significantly longer compared with the non-fever group (median survival time: 33.4 vs. 15.7 months, P=0.04), and the development of fever following the first ZOL administration was independently associated with longer overall survival. The development of fever following the first ZOL administration was an independent prognostic factor in advanced non-small cell lung cancer patients with bone metastases. Thus, ZOL-associated fever may be a predictive factor for an undefined, survival-promoting effect of ZOL.