28 research outputs found

    Analysis of the mechanism of radiation-induced upregulation of mitochondrial abundance in mouse fibroblasts.

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    Mitochondria strongly contribute to the maintenance of cellular integrity through various mechanisms, including oxidative adenosine triphosphate production and calcium homeostasis regulation. Therefore, proper regulation of the abundance, distribution and activity of mitochondria is crucial for the maintenance of cellular homeostasis. Previous studies have shown that ionizing radiation (IR) alters mitochondrial functions, suggesting that mitochondria are likely to be an important target of IR. Though IR reportedly influences cellular mitochondrial abundance, the mechanism remains largely unknown. In this study, we examined how IR influences mitochondrial abundance in mouse fibroblasts. When mouse NIH/3T3 cells were exposed to X-rays, a time-dependent increase was observed in mitochondrial DNA (mtDNA) and mitochondrial mass, indicating radiation-induced upregulation of mitochondrial abundance. Meanwhile, not only did we not observe a significant change in autophagic activity after irradiation, but in addition, IR hardly influenced the expression of two mitochondrial proteins, cytochrome c oxidase subunit IV and cytochrome c, or the mRNA expression of Polg, a component of DNA polymerase γ. We also observed that the expression of transcription factors involved in mitochondrial biogenesis was only marginally affected by IR. These data imply that radiation-induced upregulation of mitochondrial abundance is an event independent of macroautophagy and mitochondrial biogenesis. Furthermore, we found evidence that IR induced long-term cell cycle arrest and cellular senescence, indicating that these events are involved in regulating mitochondrial abundance. Considering the growing significance of mitochondria in cellular radioresponses, we believe the present study provides novel insights into understanding the effects of IR on mitochondria

    Efficacy and risk of cytotoxic chemotherapy in extensive disease-small cell lung cancer patients with interstitial pneumonia

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    Abstract Background Small cell lung cancer (SCLC) is characterized by a high propensity for metastases and a poor prognosis irrespective of high sensitivity for initial chemotherapy. Although interstitial pneumonia (IP) is one of risk factors for lung cancer, efficacy of cytotoxic chemotherapy for patients with SCLC with IP remains unclear. Our study aims to evaluate the efficacy of systemic chemotherapy and assess risk of acute exacerbation (AE)-IP with cytotoxic drugs for extensive disease (ED)-SCLC patients with IP. Methods We performed a retrospective study of 192 consecutive ED-SCLC patients with IP (n = 40) and without IP (n = 152) between 2008 and 2016. Result 31 of 40 ED-SCLC patients with IP and 130 of 152 patients without IP received systemic chemotherapy. The efficacy of chemotherapy in patients with IP was not inferior to that in patients without IP (overall survival [OS], 7.1 [95% confidence interval (CI): 0.2–14.0] vs. 10.0 [95% CI: 8.2–11.8] months, P = 0.57). Pretreatment serum levels of lactate dehydrogenase (LDH; 651.7 ± 481.0 vs. 301.4 ± 110.7 U/mL, P = 0.01) and C-reactive protein (CRP; 8.9 ± 9.6 vs. 1.8 ± 1.8 U/mL, P = 0.008) were correlated with developed AE-IP in the ED-SCLC patients with IP. Conclusion Systemic chemotherapy was effective even in ED-SCLC patients with IP. However, the risk of developed AE-IP that was high in patients with IP and should be evaluated using serum LDH and CRP levels before initial chemotherapy

    Detecting temperature and protein denaturation during thermal therapy

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    [[abstract]]In one aspect, in general, a method is provided for detecting temperature and protein denaturation of a tissue during thermal therapy. The method includes generating a plurality of MR pulse sequences that include a first group of pulse sequences and a second group of pulse sequences, and receiving a plurality of response signals that include a first and second group of response signals in response to the first and second groups of pulse sequences, respectively. A first information associated with a degree of protein denaturation of the tissue is determined based on the first and second groups of response signals. A second information associated with a temperature of the tissue is determined based on at least some of the plurality of response signals

    Prognostic significance of nestin expression in patients with resected non-small cell lung cancer treated with platinum-based adjuvant chemotherapy; relationship between nestin expression and epithelial to mesenchymal transition related markers.

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    Although adjuvant platinum-based chemotherapy (AC) has been shown to improve survival of patients with completely resected stage II and stage IIIA non-small cell lung cancer (NSCLC), its effect is limited. Nestin is a class VI intermediate filament protein expressed in neural stem cells and several cancer cells including NSCLC. In the present study, we aimed to determine its prognostic significance concerning survival in NSCLC patients receiving AC.Nestin expression in cancer cells was immunohistochemically studied in 90 patients with completely resected stage II and stage IIIA NSCLC treated with AC and its association with clinicopathologic parameters, including ABCG2, E-cadherin, and vimentin expression, was evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of nestin expression on survival.Nestin expression was observed in 28 of the 90 (31.1%) NSCLCs. Clinicopathologically, nestin expression was associated with loss of E-cadherin expression (P = 0.006) and vimentin positive expression (P < 0.001). In survival analysis, nestin expression was significantly associated with a poorer prognosis (P = 0.028). Multivariable analysis confirmed that nestin expression is an independent prognostic indicator in NSCLC patients receiving AC (HR = 2.56; 95% CI, 1.23-5.30, P = 0.01).The present study reveals that nestin expression is a prognostic indicator of a poorer survival probability in NSCLC patients receiving AC, although its prognostic significance still requires confirmation with larger patient populations

    Questionnaire survey on patient awareness of invasive rebiopsy in advanced non‐small cell lung cancer

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    Background Treatment strategies for patients with non‐small cell lung cancer (NSCLC) depend on various factors including physical condition, complications, tumor histology, and molecular profiling. Even if initial chemotherapy is efficacious, almost all patients develop treatment resistance. Invasive rebiopsy from sites of recurrence might provide insight into resistance mechanisms and aid in the selection of suitable sequential antitumor drugs. However, invasive rebiopsy might be challenging because of limited tissue availability and patient burden. Therefore, this study aimed to assess awareness of invasive rebiopsy among non‐small cell lung cancer patients. Methods This prospective questionnaire survey was performed between June 2015 and March 2016 in patients with advanced non‐small cell lung cancer. The survey was carried out at two time points: before starting first‐line chemotherapy (cohort 1), and at the time of disease progression after initial chemotherapy, but before second‐line chemotherapy (cohort 2). Results In this study, 50 and 30 patients were enrolled in cohorts 1 and 2, respectively. In cohort 1, 37 (74%) patients agreed to rebiopsy, if disease progression occurred, whereas 18 (60%) patients in cohort 2 agreed to invasive rebiopsy at disease progression. The primary reasons for rebiopsy rejection were poor physical condition and patient burden related to the initial biopsy. Seven patients answered the survey questions during the treatment course, and the acceptance rate was lower among patients who agreed to rebiopsy at disease progression than before treatment. Conclusions Invasive rebiopsy can lead to distress in some patients. To improve the consent rate for tissue rebiopsy, treatment strategies including rebiopsy should be discussed with patients during the early treatment phase
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