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Purpose: Docetaxel (DTX) is a standard chemotherapeutic drug for castration-resistant prostate cancer (CRPC), although adverse events are common. To overcome this problem, researchers have evaluated the efficacy of DTX treatment in combination with other drugs. Naftopidil is a tubulin-binding drug with fewer adverse events, implying the usefulness of this drug in clinical applications when combined with DTX. Here, we investigated the efficacy of additive naftopidil treatment in combination with DTX on prostate cancer (PCa) cells. Methods: The effects of combination treatment with DTX plus naftopidil were analyzed using two animal models of LNCaP cells plus PrSC xenografts (sub-renal capsule grafting) and PC-3 xenografts (intratibial injection). Results: Combination treatment with DTX plus naftopidil significantly inhibited cell growth in LNCaP cells compared with DTX alone. Analysis of the cooperativity index (CI) showed that combination treatment exhibited additive effects on DTX-induced growth inhibition in LNCaP cells. In contrast, combination treatment showed more than an additive (synergistic) effect on DTX-induced apoptosis in LNCaP and PC-3 cells. In LNCaP cells plus PrSC xenografts, combination treatment showed synergistic effects on DTX-induced apoptosis. The synergistic effects of naftopidil on DTX-induced apoptosis were also observed in PC-3 xenografts. Conclusions: Our results demonstrated that additive naftopidil treatment in combination with DTX increased the efficacy of DTX for the treatment of LNCaP and PC-3 tumors in vivo. Thus, additive naftopidil treatment showed a synergistic effect on DTX-induced apoptosis in PCa cells in vitro and in vivo, suggesting that this treatment approach may yield improved clinical benefits compared with DTX alone. [ABSTRACT FROM AUTHOR]

Purpose: Clinically, radiotherapy (RT) often leads to the development of prostate cancer (PCa) resistance because of protective responses in cancer cells. One of the mechanisms includes the upregulation of RT-induced antioxidant enzymes. Thus, combination therapy with RT and certain pharmaceutical drugs targeting antioxidant enzymes may be ideal for increasing the efficacy of RT with minimum side effects. Naftopidil is a subtype-selective α-adrenoceptor antagonist used for the treatment of benign prostatic hyperplasia (BPH). In our drug repositioning study, naftopidil showed not only unique growth-inhibitory effects but also AKT phosphorylation-inhibitory effects in PC-3 human PCa cells. Here, we examined the efficacy of additive naftopidil treatment in combination with RT in PC-3 cells. Methods: The effects of combination therapy with RT plus naftopidil were analyzed using an animal model of PC-3 xenografts in BALB/c nude mice. The expression of the antioxidant enzyme manganese superoxide dismutase (MnSOD) was evaluated by western blotting. Results: Combination therapy with RT plus naftopidil induced a more efficacious delay in PC-3 xenograft tumor growth as compared with monotherapy with naftopidil or RT. In PC-3 tumors, combination therapy with RT plus naftopidil suppressed the upregulation of RT-induced MnSOD expression. In vitro, neither AKT inhibitor IV nor naftopidil directly altered MnSOD expression. Upregulation of RT-induced MnSOD expression was markedly suppressed by combination treatment with RT plus AKT inhibitor IV or naftopidil. Conclusions: These results suggest that additive naftopidil treatment in combination with RT may increase the efficacy of RT for the treatment of PCa. [ABSTRACT FROM AUTHOR]

Background: Poor oral health is associated with an increased risk of dementia in the elderly. One possible pathway linking these two phenomena is lacunar infarction, a potential cause of dementia. An association between poor oral health and an increased risk of ischaemic stroke has been recognised through the oral infection-inflammation pathway. However, little is known about whether poor oral health is associated with the progression of lacunar infarction. Objective: We examined the association between variables related to oral health and lacunar infarction, as detected by magnetic resonance imaging (MRI). Methods: A total of 110 subjects (52 men, 58 women), aged 27-76 years, who visited our periodontology clinic participated in this study. The subjects underwent dental radiography, periodontal examinations and brain MRI. One experienced specialist in cardiovascular disease and one experienced neurosurgeon determined the number of lacunar infarctions on brain MRI. Periodontologists performed clinical periodontal examinations. Variables related to oral health were determined from the radiographs by an oral radiologist. Information on the subjects' lifestyles and disease histories were obtained using a structured questionnaire and confirmed by clinical records. Adjacent categories logit regression analysis with backward elimination was used to determine variables associated with three groups based on the number of lacunar infarctions. Results: Of the 110 subjects, 61 had lacunar infarctions. Nineteen had multiple (≥7) lesions. Aging (p = 0.0004), increased time spent in physical activity per day (p = 0.042), the presence of hypertension (p = 0.006), the absence of hyperlipidaemia (p = 0.045), the presence of diabetes mellitus (p = 0.025) and low alveolar bone height (p = 0.026) were significantly associated with an increased number of lacunar infarctions in the final regression model. The significance of hyperlipidaemia and alveolar bone height disappeared in an unadjusted model. An increased pocket depth, which indicates current periodontal disease progression, tended to be associated with an increased number of lacunar infarctions (p = 0.058). This tendency did not disappear in an unadjusted model. Conclusion: Our results suggest that lacunar infarction may be associated with current periodontal disease in Japanese adults. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]