90 research outputs found

    Tolfenamic Acid Induces Apoptosis and Growth Inhibition in Head and Neck Cancer: Involvement of NAG-1 Expression

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    Nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1) is induced by nonsteroidal anti-inflammatory drugs and possesses proapoptotic and antitumorigenic activities. Although tolfenamic acid (TA) induces apoptosis in head and neck cancer cells, the relationship between NAG-1 and TA has not been determined. This study investigated the induction of apoptosis in head and neck cancer cells treated by TA and the role of NAG-1 expression in this induction. TA reduced head and neck cancer cell viability in a dose-dependent manner and induced apoptosis. The induced apoptosis was coincident with the expression of NAG-1. Overexpression of NAG-1 enhanced the apoptotic effect of TA, whereas suppression of NAG-1 expression by small interfering RNA attenuated TA-induced apoptosis. TA significantly inhibited tumor formation as assessed by xenograft models, and this result accompanied the induction of apoptotic cells and NAG-1 expression in tumor tissue samples. Taken together, these results demonstrate that TA induces apoptosis via NAG-1 expression in head and neck squamous cell carcinoma, providing an additional mechanistic explanation for the apoptotic activity of TA

    Regulation of GDF-15, a distant TGF-β superfamily member, in a mouse model of cerebral ischemia

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    GDF-15 is a novel distant member of the TGF-β superfamily and is widely distributed in the brain and peripheral nervous system. We have previously reported that GDF-15 is a potent neurotrophic factor for lesioned dopaminergic neurons in the substantia nigra, and that GDF-15-deficient mice show progressive postnatal losses of motor and sensory neurons. We have now investigated the regulation of GDF-15 mRNA and immunoreactivity in the murine hippocampal formation and selected cortical areas following an ischemic lesion by occlusion of the middle cerebral artery (MCAO). MCAO prominently upregulates GDF-15 mRNA in the hippocampus and parietal cortex at 3 h and 24 h after lesion. GDF-15 immunoreactivity, which is hardly detectable in the unlesioned brain, is drastically upregulated in neurons identified by double-staining with NeuN. NeuN staining reveals that most, if not all, neurons in the granular layer of the dentate gyrus and pyramidal layers of the cornu ammonis become GDF-15-immunoreactive. Moderate induction of GDF-15 immunoreactivity has been observed in a small number of microglial cells identified by labeling with tomato lectin, whereas astroglial cells remain GDF-15-negative after MCAO. Comparative analysis of the size of the infarcted area after MCAO in GDF-15 wild-type and knockout mice has failed to reveal significant differences. Together, our data substantiate the notion that GDF-15 is prominently upregulated in the lesioned brain and might be involved in orchestrating post-lesional responses other than the trophic support of neurons

    Decreased transcription-coupled nucleotide excision repair capacity is associated with increased p53- and MLH1-independent apoptosis in response to cisplatin

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    Abstract Background One of the most commonly used classes of anti-cancer drugs presently in clinical practice is the platinum-based drugs, including cisplatin. The efficacy of cisplatin therapy is often limited by the emergence of resistant tumours following treatment. Cisplatin resistance is multi-factorial but can be associated with increased DNA repair capacity, mutations in p53 or loss of DNA mismatch repair capacity. Methods RNA interference (RNAi) was used to reduce the transcription-coupled nucleotide excision repair (TC-NER) capacity of several prostate and colorectal carcinoma cell lines with specific defects in p53 and/or DNA mismatch repair. The effect of small inhibitory RNAs designed to target the CSB (Cockayne syndrome group B) transcript on TC-NER and the sensitivity of cells to cisplatin-induced apoptosis was determined. Results These prostate and colon cancer cell lines were initially TC-NER proficient and RNAi against CSB significantly reduced their DNA repair capacity. Decreased TC-NER capacity was associated with an increase in the sensitivity of tumour cells to cisplatin-induced apoptosis, even in p53 null and DNA mismatch repair-deficient cell lines. Conclusion The present work indicates that CSB and TC-NER play a prominent role in determining the sensitivity of tumour cells to cisplatin even in the absence of p53 and DNA mismatch repair. These results further suggest that CSB represents a potential target for cancer therapy that may be important to overcome resistance to cisplatin in the clinic

    Fabrication of graphene film composite electrochemical biosensor as a pre-screening algal toxin detection tool in the event of water contamination

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    In this work, we fabricated a novel graphene film composite biosensor for microcystin-LR detection as an alternative to time-consuming, expensive, non-portable and often skills-demanding conventional methods of analysis involved in water quality monitoring and assessment. Excellent linear correlation (R2 = 0.99) of the electron-transfer resistance was achieved over a wide range of microcystin-LR (MC-LR) concentration, i.e. 0.005–10 μg/L. As-prepared graphene film composite biosensors can specifically detect MC-LR with remarkable sensitivity and detection limit (2.3 ng/L) much lower than the World Health Organization (WHO) provisional guideline limit of microcystin-LR concentration (i.e. 1 μg/L) in different water sources. Their great potential can be attributed to large active surface area of graphene film and efficient charge transfer process enabled by their high conductivity. Developed graphene film composite biosensors were also successfully applied to determination of MC-LR in several environmental water samples with high detection recovery, which offers a promising possibility of large-scale manufacture of sensor tips due to their macroscopic free-standing nature, the scalable fabrication route and easily tunable size

    Patients’ views of treatment focused genetic testing (TFGT): some lessons for the mainstreaming of BRCA1 and BRCA2 testing

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    This paper explores patients' views and experiences of undergoing treatment-focused BRCA1 and BRCA2 genetic testing (TFGT), either offered following triaging to clinical genetics (breast cancer) or as part of a mainstreamed care pathway in oncology (ovarian cancer). Drawing on 26 in-depth interviews with patients with breast or ovarian cancer who had undergone TFGT, this retrospective study examines patients' views of genetic testing at this point in their care pathway, focusing on issues, such as initial response to the offer of testing, motivations for undergoing testing, and views on care pathways. Patients were amenable to the incorporation of TFGT at an early stage in their cancer care irrespective of (any) prior anticipation of having a genetic test or family history. While patients were glad to have been offered TFGT as part of their care, some questioned the logic of the test's timing in relation to their cancer treatment. Crucially, patients appeared unable to disentangle the treatment role of TFGT from its preventative function for self and other family members, suggesting that some may undergo TFGT to obtain information for others rather than for self
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