Tomomi Ichikawa

SRT1720, a SIRT1 activator, promotes tumor cell migration, and lung metastasis of breast cancer in mice

Silent information regulator 2 (SIR2) is a highly conserved protein, the mammalian orthologue of which, SIRT1, exhibits histone deacetylase activity. SIRT1 is involved not in only longevity due to caloric restriction but in a variety of diseases such as diabetes, cardiovascular dysfunction and neurodegeneration. However, accumulating evidence shows that SIRT1 is overexpressed in various types of malignant cells, and its inhibitors suppress the growth of tumor cells. The relationship between SIRT1 and metastasis remains to be clarified. Here, we examined the effect of SRT1720, a SIRT1 activator, on lung metastasis of breast cancer cells. 4T1 breast cancer cells were subcutaneously implanted into syngeneic BALB/c mice and SRT1720 was administered alone or with an antitumor agent, cisplatin. As expected, cisplatin decreased the lung metastasis score, whereas SRT1720 increased metastasis irrespective of cisplatin. In the primary tumors, cisplatin suppressed the mRNA level of angiopoietin-like protein 4 (angptl4), a lung metastasis-promoting gene product of breast cancer, but SRT1720 reduced the effectiveness of cisplatin. The results obtained with animal experiments were in accordance with those in human cancer cells; SRT1720 significantly increased the amount of VEGF secreted from MDA-MB-231 cells. Moreover, a transendothelial cell migration assay showed that SRT1720 promotes the migration of MDA-MB-231 cells across an endothelial cell layer despite the presence of cisplatin. These findings imply that SRT1720 promotes the pulmonary metastasis of breast cancer cells and SIRT1 may be an important target for suppressing metastasis to the lung.

Sirtuin 1 activator SRT1720 suppresses inflammation in an ovalbumin-induced mouse model of asthma.

Background and objective:  In asthma, reduced histone deacetylase activity and enhanced histone acetyltransferase activity in the lungs have been reported. However, the precise function of Sirtuin 1 (Sirt1), a class III histone deacetylase, and the effect of the Sirt1 activator SRT1720 on allergic inflammation have not been fully elucidated.

Visceral adipose tissue level, as estimated by the bioimpedance analysis method, is associated with impaired lung function

Aims/Introduction:  It has been reported that metabolic syndrome is associated with impaired lung function, and abdominal obesity is regarded as the most important determinant of this association. We evaluated the association between a component of metabolic syndrome, indices of body composition, including the total adipose tissue content, lean bodyweight and visceral adipose tissue content, as assessed by bioimpedance analysis, and lung function.

Miliary brain metastasis presenting with calcification in a patient with lung cancer: a case report

IntroductionMiliary brain metastasis is an extremely rare form of brain metastasis which can present with atypical imaging findings. We report the case of a patient with miliary brain metastasis of lung cancer showing calcification in metastatic lesions.Case presentationA 68-year-old Japanese woman was diagnosed with lung adenocarcinoma. Brain computed tomography revealed multiple small calcified lesions in both cerebral hemispheres. Mutation of the epidermal growth factor receptor gene (exon 21, L858R) in lung cancer cells was detected, and treatment with gefitinib was initiated. A partial response was observed; however, the patient was readmitted to our hospital because of regrowth of the primary lesion and complaints of nausea, headache, and difficulty walking. Brain magnetic resonance imaging revealed scattered tiny nodules enhanced by gadolinium. A diagnosis of leptomeningeal carcinomatosis was made on the basis of cerebrospinal fluid cytology. The patient’s general status worsened, and she died 356 days after the day of first medical examination. Upon autopsy, the brain was found to be edematous and swollen. Lung carcinoma cells were diffusely disseminated on the meningeal surface. Metastatic foci of small nodular form, accompanied by calcifications, were also found in the brain parenchyma. We diagnosed miliary metastasis of lung carcinoma.ConclusionsTo the best of our knowledge, this is the third report of calcified miliary brain metastasis confirmed by autopsy. We describe calcified lesions that increased in size during the clinical course of nine months. Brain computed tomography findings that reveal multiple small calcified lesions in patients with malignancy should raise suspicion of miliary brain metastasis.

Lactate Dehydrogenase and Body Mass Index are Prognostic Factors in Patients with Recurrent Small Cell Lung Cancer Receiving Amrubicin

Aims and Background Amrubicin monotherapy can be an effective treatment option for patients with recurrent small cell lung cancer (SCLC). We conducted this retrospective study to investigate the prognostic factors in patients with recurrent SCLC receiving amrubicin monotherapy. Methods The associations between survival and clinical data, including the performance status, body mass index (BMI), plasma lactate dehydrogenase (LDH) level, and plasma neuron-specific enolase level, were evaluated in patients with recurrent SCLC, and a subset analysis of patients with platinum-resistant disease was conducted. Results In all, 37 patients were evaluated. The median survival from the date of initiation of amrubicin monotherapy was 9.1 months (95% confidence interval 4.7–12.0 months). Multivariate analysis using a Cox proportional hazard model identified the plasma LDH level (p = 0.049), BMI (p = 0.031), and platinum resistance (p = 0.032) as independent factors associated with survival. The same associations were also observed in the subset of patients with platinum-resistant disease. Conclusions Our findings suggest that the plasma LDH level and BMI may be useful prognostic factors in patients with SCLC receiving amrubicin monotherapy, including patients with platinum-resistant disease.

Clinical Parameters for Predicting the Survival in Patients with Squamous and Non-squamous-cell NSCLC Receiving PD-1 Inhibitor Therapy

We explored the associations between progression-free survival (PFS) after the initiation of PD-1 inhibitor therapy and the clinical parameters in patients with NSCLC. We reviewed the clinical data of patients with NSCLC treated with PD-1 inhibitor. Data of a total of 36 patients, including 16 patients with squamous cell NSCLC and 20 patients with non-squamous cell NSCLC were reviewed. Multivariate analyses identified EGFR status, C-reactive protein (CRP), and PFS following previous therapy as being significantly associated with the PFS after initiation of PD-1 inhibitor therapy in patients with NSCLC. In patients with squamous cell NSCLC, the blood neutrophil/lymphocyte ratio (NLR), serum lactate dehydrogenase (LDH), serum C-reactive protein (CRP), and PFS following previous therapy were identified as being significantly associated with the PFS after initiation of PD-1 inhibitor therapy. However, none of these associations, except for PFS following previous therapy, were found in patients with non-squamous cell NSCLC. NLR, LDH and CRP were associated with the PFS after initiation of PD-1 inhibitor therapy in patients with squamous cell NSCLC, and PFS following previous therapy was the common parameter associated with the PFS after initiation of PD-1 inhibitor therapy in both squamous-cell NSCLC and non-squamous-cell NSCLC patients.