Treatment with insulin-like growth factor 1 receptor inhibitor reverses hypoxia-induced epithelial-mesenchymal transition in non-small cell lung cancer.

Insulin-like growth factor 1 receptor (IGF1R) is expressed in many types of solid tumors including non-small cell lung cancer (NSCLC), and enhanced activation of IGF1R is thought to reflect cancer progression. Epithelial-mesenchymal transition (EMT) has been established as one of the mechanisms responsible for cancer progression and metastasis, and microenvironment conditions, such as hypoxia, have been shown to induce EMT. The purposes of this study were to address the role of IGF1R activation in hypoxia-induced EMT in NSCLC and to determine whether inhibition of IGF1R might reverse hypoxia-induced EMT. Human NSCLC cell lines A549 and HCC2935 were exposed to hypoxia to investigate the expression of EMT-related genes and phenotypes. Gene expression analysis was performed by quantitative real-time PCR and cell phenotypes were studied by morphology assessment, scratch wound assay, and immunofluorescence. Hypoxia-exposed cells exhibited a spindle-shaped morphology with increased cell motility reminiscent of EMT, and demonstrated the loss of E-cadherin and increased expression of fibronectin and vimentin. Hypoxia also led to increased expression of IGF1, IGF binding protein-3 (IGFBP3), and IGF1R, but not transforming growth factor ß1 (TGFß1). Inhibition of hypoxia-inducible factor 1α (HIF1α) with YC-1 abrogated activation of IGF1R, and reduced IGF1 and IGFBP3 expression in hypoxic cells. Furthermore, inhibition of IGF1R using AEW541 in hypoxic condition restored E-cadherin expression, and reduced expression of fibronectin and vimentin. Finally, IGF1 stimulation of normoxic cells induced EMT. Our findings indicated that hypoxia induced EMT in NSCLC cells through activation of IGF1R, and that IGF1R inhibition reversed these phenomena. These results suggest a potential role for targeting IGF1R in the prevention of hypoxia-induced cancer progression and metastasis mediated by EMT.

Hypoxia induces gefitinib resistance in non-small-cell lung cancer with both mutant and wild-type epidermal growth factor receptors.

Somatic mutations in the epidermal growth factor receptor (EGFR) gene, such as exon 19 deletion mutations, are important factors in determining therapeutic responses to gefitinib in non-small-cell lung cancer (NSCLC). However, some patients have activating mutations in EGFR and show poor responses to gefitinib. In this study, we examined three NSCLC cell lines, HCC827, PC9, and HCC2935, that expressed an EGFR exon 19 deletion mutation. All cells expressed mutant EGFR, but the PC9 and HCC2935 cells also expressed wild-type EGFR. The HCC827 cells were highly sensitive to gefitinib under both normoxia and hypoxia. However, the PC9 and HCC2935 cells were more resistant to gefitinib under hypoxic conditions compared to normoxia. Phosphorylation of EGFR and ERK was suppressed with gefitinib treatment to a lesser extent under hypoxia. The expression of transforming growth factor-α (TGFα) was dramatically upregulated under hypoxia, and the knockdown of TGFα or hypoxia-inducible factor-1α (HIF1α) reversed the resistance to gefitinib in hypoxic PC9 and HCC2935 cells. Finally, introduction of the wild-type EGFR gene into the HCC827 cells caused resistance to gefitinib under hypoxia. This phenomenon was also reversed by the knockdown of TGFα or HIF1α. Our results indicate that hypoxia causes gefitinib resistance in EGFR-mutant NSCLC through the activation of wild-type EGFR mediated by the upregulation of TGFα. The presence of wild-type and mutant EGFR along with tumor hypoxia are important factors that should be considered when treating NSCLC patients with gefitinib.

Hochuekkito (TJ-41), a Kampo Formula, Ameliorates Cachexia Induced by Colon 26 Adenocarcinoma in Mice.

Cachexia, a major cause of cancer-related death, is characterized by depletion of muscle and fat tissues, anorexia, asthenia, and hypoglycemia. Recent studies indicate that secretions of proinflammatory cytokines such as interleukin-6 (IL-6) play a crucial role in cachexia development, and that these cytokines are secreted from not only cancer cells but also host cells such as macrophages. In this study, we investigated the therapeutic effects of hochuekkito, a Kampo formula, on cachexia induced by colon 26 adenocarcinoma in mice. Hochuekkito treatment did not inhibit tumor growth, but significantly attenuated the reduction in carcass weight, food and water intake, weight of the gastrocnemius muscle and fat tissue around the testes, and decrease of serum triglyceride level compared with controls. Furthermore, hochuekkito treatment significantly reduced serum IL-6 level and IL-6 expression level in macrophages in tissues surrounding the tumor. In vitro studies showed that hochuekkito suppressed the production of IL-6 by THP-1 or RAW264.7 macrophage cells, although it did not affect IL-6 production by colon 26 carcinoma cells. These results suggest that hochuekkito inhibits the production of proinflammatory cytokines, particularly IL-6, by host cells such as macrophages. Therefore, hochuekkito may be a promising anticachectic agent for the treatment of patients with cancer.

[Efficacy of erlotinib after gefitinib administration in patients with non-small cell lung cancer].

We retrospectively evaluated the survival benefit of dispensing erlotinib after gefitinib administration in patients with nonsmall cell lung cancer. Ninety patients treated with erlotinib in our hospital were divided into two groups: G+ group patients who were treated with erlotinib with prior gefitinib administration, and G- group patients who were treated with erlotinib without prior gefitinib administration. Median survival time (MST) in all 90 patients was 275 days. MST of 22 patients in the G+ group was shorter than that of 68 patients in G- group, but this difference was not statistically significant (283 days vs 177 days, p=0. 329). MST in 19 patients of the G+group who were administered erlotinib for over 1 month was shorter than that of 49G-group patients who were administered erlotinib over 1 month. However, this difference was also not statistically significant(395 days vs 238 days, p=0. 575). Univariate analysis demonstrated that EGFR mutation unknown, time to progression (TTP) with gefitinib longer than 1 year, gefitnib administration longer than 1 year, and responder to gefitinib, suggest a better prognosis. Mutivariate analysis revealed that only TTP with gefitinib longer than 1 year was an independent prognostic factor for patients in the G+ group.

Sex hormones alter Th1 responses and enhance granuloma formation in the lung.

BACKGROUND: The lung is one of the sites of granulomatous responses, which are characterized by the recruitment and organization of activated macrophages and lymphocytes. There have been several reports that have shown that some pulmonary granulomatous diseases, such as sarcoidosis and nontuberculous mycobacterial disease, are likely to be characterized by a preponderance in postmenopausal females. Although sex hormones have been shown to play an important role in the regulation of the immune system, the influence of sex hormones on pulmonary granuloma formation is still unclear. OBJECTIVES: The purpose of this study was to assess whether sex hormones are involved in granulomatous inflammation and to evaluate how sex hormones modulate this response in the lung. METHODS: Ovariectomized rats were used as an experimental postmenopausal model in which chronic pulmonary granulomatous inflammation was induced by intravenous injection of complete Freund's adjuvant. RESULTS: Histological analysis of lung tissues demonstrated enhancement of granuloma formation in the ovariectomized group. Such enhanced granuloma formation was significantly associated with generalized Th1-biased cytokine production in the bronchoalveolar lavage fluid. CONCLUSION: These results indicate that sex hormones play an important role in pulmonary granuloma formation by altering the Th1 responses.

[Twelve cases of advanced thymic carcinoma: a clinical review].

Thymic carcinoma is comparatively rare and no standard treatment has been established for advanced stage cases. We reviewed our therapeutic experience in 12 cases of thymic carcinoma. They consisted of 9 men and 3 women, ranging from 38 to 69 years of age, with a mean age of 56.5. According to Masaoka's classification, 5 cases were stage III and 7 were preoperative stage IVb. Nine cases were squamous cell carcinoma and 3 were adenocarcinoma. Four cases of preoperative clinical stage III underwent extended thymectomy, but none were completely resected and were classified as stage IV postoperatively. Chemotherapy combined with radiation therapy was given in 1 case, chemotherapy (monotherapy) was given in 4 cases, radiation therapy was given in 1 case, and 2 cases received best supportive care. The median survival time (MST) of patients who had undergone combined modality treatments including surgery was 1971 days, which was longer than the MST of 567 days of patients who were not able to undergo surgery. The prognosis outcome of advanced thymic carcinoma is poor, but combined modality therapies such as surgery, chemotherapy and radiation can be effective for some advanced thymic carcinoma cases.

Efficacy and Safety of Capecitabine and Oxaliplatin (CapOX) as an Adjuvant Therapy in Japanese for Stage II/III Colon Cancer in a Group at High Risk of Recurrence in Retrospective Study.

A number of large-scale clinical trials have demonstrated that using a combination of oxaliplatin and fluoropyrimidines as an adjuvant chemotherapy for stage II/III colon cancer improved the prognosis. However, there has only been experience in Japanese patients with using CapOX therapy, in which capecitabine and oxaliplatin are used in combination. Therefore, our objective was to evaluate the efficacy and safety of CapOX in Japanese patients as an adjuvant chemotherapy for colon cancer in a single institute retrospective study. The efficacy and safety of CapOX as an adjuvant chemotherapy for patients with stage III colon cancer and stage II patients who had a signature for high risk of recurrence were evaluated in patients who had undergone surgery at our institution between December 1, 2009 and March 31, 2013. Forty-one patients received CapOX therapy during the study period: 23 men and 18 women with median age of 68.0 years (35-79 years). Performance status was 0 for 33 patients, and PS 1 for eight patients. The clinical stages were stage II in 14 patients, stage IIIA in 15 patients, and stage IIIB in 12 patients. The median number of CapOX cycles was eight (two to eight courses). The treatment completion rate was 82.9%. Five-year DFS rates were 63.8%. Five-year OS rates were 71.0%. In terms of adverse events, the serious adverse events of grade 3 or higher seen among all patients were neutropenia in four patients, thrombocytopenia in one patient, and peripheral sensory neuropathy in seven patients. However, hand-foot syndrome, which is characteristic of capecitabine, was not observed. Efficacy and tolerability of CapOX in Japanese patients as an adjuvant chemotherapy after colon cancer surgery was demonstrated.

Hypoxia increases gefitinib-resistant lung cancer stem cells through the activation of insulin-like growth factor 1 receptor.

Accumulating evidence indicates that a small population of cancer stem cells (CSCs) is involved in intrinsic resistance to cancer treatment. The hypoxic microenvironment is an important stem cell niche that promotes the persistence of CSCs in tumors. Our aim here was to elucidate the role of hypoxia and CSCs in the resistance to gefitinib in non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9 and HCC827, which express the EGFR exon 19 deletion mutations, were exposed to high concentration of gefitinib under normoxic or hypoxic conditions. Seven days after gefitinib exposure, a small fraction of viable cells were detected, and these were referred to as "gefitinib-resistant persisters" (GRPs). CD133, Oct4, Sox2, Nanog, CXCR4, and ALDH1A1-all genes involved in stemness-were highly expressed in GRPs in PC9 and HCC827 cells, and PC9 GRPs exhibited a high potential for tumorigenicity in vivo. The expression of insulin-like growth factor 1 (IGF1) was also upregulated and IGF1 receptor (IGF1R) was activated on GRPs. Importantly, hypoxic exposure significantly increased sphere formation, reflecting the self-renewal capability, and the population of CD133- and Oct4-positive GRPs. Additionally, hypoxia upregulated IGF1 expression through hypoxia-inducible factor 1α (HIF1α), and markedly promoted the activation of IGF1R on GRPs. Knockdown of IGF1 expression significantly reduced phosphorylated IGF1R-expressing GRPs under hypoxic conditions. Finally, inhibition of HIF1α or IGF1R by specific inhibitors significantly decreased the population of CD133- and Oct4-positive GRPs, which were increased by hypoxia in PC9 and HCC827 cells. Collectively, these findings suggest that hypoxia increased the population of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC by activating IGF1R. Targeting the IGF1R pathway may be a promising strategy for overcoming gefitinib resistance in EGFR mutation-positive NSCLC induced by lung CSCs and microenvironment factors such as tumor hypoxia.

From tumor hypoxia to cancer progression: the implications of hypoxia-inducible factor-1 expression in cancers.

Hypoxia, defined as a decrease of tissue oxygen levels, represents a fundamental pathophysiological condition in the microenvironment of solid tumors. Tumor hypoxia is known to be associated with radio/chemo-resistance and metastasis that eventually lead to cancer progression contributing to poor prognosis in cancer patients. Among transcription factors that accumulated under hypoxic conditions, hypoxia-inducible factor-1 (HIF-1) is a master transcription factor that has received the most intense attention in this field of research due to its capacity to modulate several hundred genes. With a clearer understanding of the HIF-1 pathway, efforts are directed at manipulation of this complex genetic process in order to ultimately decrease cellular HIF-1 levels. Some novel agents have been shown to have HIF-1 inhibition activity through a variety of molecular mechanisms and have provided promising results in the preclinical setting.

Distinct roles of cholinergic receptors in small cell lung cancer cells.

BACKGROUND: Cholinergic receptors are expressed in small cell lung cancer (SCLC); however, the distinct functions of muscarinic cholinergic receptor 3 (mAChR3) and the nicotinic cholinergic receptor (nAChR) in SCLC have not yet been completely elucidated. MATERIALS AND METHODS: RT-PCR and Western blotting were used to investigate the expression of cholinergic receptors. Flow cytometry was used to detect the integrin expression. Cell proliferation, adhesion and migration assays were carried out in vitro to determine the roles of the cholinergic receptors in SBC3 human SCLC cells. RESULTS: Both mAChR3 and nAChR were expressed in the SBC3 cells. Acetylcholine iodide (Ach) stimulated SBC3 cell proliferation, adhesion and migration toward fibronectin (Fn). The mAChR3 antagonist, 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP), or the nAChR antagonist, mecamylamine hydrochloride (Meca), inhibited SBC3 cell proliferation in the presence or the absence of exogenous Ach. 4-DAMP abrogated cell adhesion and migration toward Fn induced by Ach, while Meca had no effect. Interestingly, Ach did not alter Fn receptor (alphavbeta1 or alpha5beta1 integrin) expression, while anti-beta1 integrin antibody or anti-alphav and anti-alpha5 integrin antibody completely abrogated cell adhesion to Fn induced by Ach. CONCLUSION: Both mAChR3 and nAChR are expressed in SCLC. SBC3 cell proliferation is regulated in vitro through both cholinergic receptors. In contrast, SBC3 cell migration and adhesion toward Fn are modulated only by mAChR. Moreover, the stimulatory effects of Ach on cell adhesion and migration through mAChR3 are presumably modulated by functional alteration of alphavbeta1 and alpha5beta1 integrin, but not by any variation in their expression. The mAChR3 antagonist may therefore be a beneficial therapeutic modality for SCLC patients, especially those with chronic obstructive pulmonary disease (COPD) as a comorbidity.