19 research outputs found

    MDM2 antagonist Nutlin-3a potentiates antitumour activity of cytotoxic drugs in sarcoma cell lines

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    <p>Abstract</p> <p>Background</p> <p>Frequent failure and severe side effects of current sarcoma therapy warrants new therapeutic approaches. The small-molecule MDM2 antagonist Nutlin-3a activates the p53 pathway and efficiently induces apoptosis in tumours with amplified <it>MDM2 </it>gene and overexpression of MDM2 protein. However, the majority of human sarcomas have normal level of MDM2 and the therapeutic potential of MDM2 antagonists in this group is still unclear. We have investigated if Nutlin-3a could be employed to augment the response to traditional therapy and/or reduce the genotoxic burden of chemotherapy.</p> <p>Methods</p> <p>A panel of sarcoma cell lines with different <it>TP53 </it>and <it>MDM2 </it>status were treated with Nutlin-3a combined with Doxorubicin, Methotrexate or Cisplatin, and their combination index determined.</p> <p>Results</p> <p>Clear synergism was observed when Doxorubicin and Nutlin-3a were combined in cell lines with wild-type <it>TP53 </it>and amplified <it>MDM2</it>, or with Methotrexate in both <it>MDM2 </it>normal and amplified sarcoma cell lines, allowing for up to tenfold reduction of cytotoxic drug dose. Interestingly, Nutlin-3a seemed to potentiate the effect of classical drugs as Doxorubicin and Cisplatin in cell lines with mutated <it>TP53</it>, but inhibited the effect of Methotrexate.</p> <p>Conclusion</p> <p>The use of Nutlin in combination with classical sarcoma chemotherapy shows promising preclinical potential, but since clear biomarkers are still lacking, clinical trials should be followed up with detailed tumour profiling.</p

    Metallo-β-lactamase inhibitors by bioisosteric replacement: preparation, activity and binding

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    Bacterial resistance is compromising the use of β-lactam antibiotics including carbapenems. The main resistance mechanism against β-lactams is hydrolysis of the β-lactam ring mediated by serine- or metallo-β-lactamases (MBLs). Although several inhibitors of MBLs have been reported, none has been developed into a clinically useful inhibitor. Mercaptocarboxylic acids are among the most prominent scaffolds reported as MBL inhibitors. In this study, the carboxylate group of mercaptocarboxylic acids was replaced with bioisosteric groups like phosphonate esters, phosphonic acids and NH-tetrazoles. The influence of the replacement on the bioactivity and inhibitor binding was evaluated. A series of bioisosteres of previously reported inhibitors was synthesized and evaluated against the MBLs VIM-2, NDM-1 and GIM- 1. The most active inhibitors combined a mercapto group and a phosphonate ester or acid, with two/three carbon chains connecting a phenyl group. Surprisingly, also compounds containing thioacetate groups instead of thiols showed low IC50 values. High-resolution crystal structures of three inhibitors in complex with VIM-2 revealed hydrophobic interactions for the diethyl groups in the phosphonate ester (inhibitor 2b), the mercapto bridging the two active site zinc ions, and tight stacking of the benzene ring to the inhibitor between Phe62, Tyr67, Arg228 and His263. The inhibitors show reduced enzyme activity in Escherichia coli cells harboring MBL. The obtained results will be useful for further structural guided design of MBL inhibitors

    Survival after Cancer-related Venous Thrombosis:the Scandinavian Thrombosis and Cancer Study

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    Patients with cancer have an increased risk of developing venous thromboembolism (VTE), and this combination is reported to result in poorer survival compared with cancer alone. This study aimed to investigate the impact of VTE on the survival of patients with cancer in a general population. The Scandinavian Thrombosis and Cancer (STAC) cohort, a population-based cohort including 144 952 participants without previous VTE or cancer, was used. During follow-up, cancer and VTE incidences were registered. “Cancer-related VTE” was defined as VTE diagnosed in patients with overt or occult cancer. The survival of participants without cancer and/or VTE (“disease-free”) was compared with the survival of participants with cancer and cancer-related VTE. Cox regression models with cancer and VTE as time-varying exposures were performed to calculate hazard ratios for death. Subanalyses were performed across cancer types and stages and VTE type (deep vein thrombosis or pulmonary embolism). During follow-up (mean, 11.7 years), 14 621 participants developed cancer, and 2444 developed VTE, of which 1241 were cancer-related. The mortality rates (per 100 person years) for disease-free participants, VTE only, cancer only, and cancer-related VTE were 0.63, 5.0, 9.2, and 45.3, respectively. Compared with patients with cancer only, the risk of death for patients with cancer-related VTE was increased 3.4-fold. Within all cancer types, the occurrence of VTE increased the mortality risk 2.8- to 14.7-fold. In a general population, patients with cancer with VTE had a 3.4-fold higher mortality risk than patients with cancer without VTE, independent of cancer type

    PALLiON – PALLiative care Integrated in ONcology: study protocol for a Norwegian national cluster-randomized control trial with a complex intervention of early integration of palliative care

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    Background Several publications have addressed the need for a systematic integration of oncological care focused on the tumor and palliative care (PC) focused on the patient with cancer. The exponential increase in anticancer treatments and the high number of patients living longer with advanced disease have accentuated this. Internationally, there is now a persuasive argument that introducing PC early during anticancer treatment in patients with advanced disease has beneficial effects on symptoms, psychological distress, and survival. Methods This is a national cluster-randomized trial (C-RCT) in 12 Norwegian hospitals. The trial investigates effects of early, systematic integration of oncology and specialized PC in patients with advanced cancer in six intervention hospitals compared with conventional care in six. Hospitals are stratified on the size of local catchment areas before randomization. In the intervention hospitals, a three-part complex intervention will be implemented. The backbone of the intervention is the development and implementation of patient-centered care pathways that contain early, compulsory referral to PC and regular and systematic registrations of symptoms. An educational program must be completed before patient inclusion. A total of 680 patients with advanced cancer and one caregiver per patient are included when patients come for start of last line of chemotherapy, defined according to national treatment guidelines. Data registration, clinical variables, and patient- and caregiver-reported outcomes take place every 2 months for 1 year or until death. The primary outcome is use of chemotherapy in the last 3 months of life by comparing the proportion of patients who receive this in the intervention and control groups. Primary outcome is use of chemotherapy in the last 3 months before death, i.e. number of patients. Secondary outcomes are initiation, discontinuation and number of cycles, last 3 months of life, administration of other medical interventions in the last month of life, symptom burden, quality of life (QoL), satisfaction with information and follow-up, and caregiver health, QoL, and satisfaction with care. Discussion Results from this C-RCT will be used to raise the awareness about the positive outcomes of early provision of specialized palliative care using pathways for patients with advanced cancer receiving medical anticancer treatment. The long-term clinical objective is to integrate these patient-centered pathways in Norwegian cancer care. The specific focus on the patient and family and the organization of a predictable care trajectory is consistent with current Norwegian strategies for cancer care. Trial registration ClinicalTrials.gov, NCT03088202. Registered on 23 March 2017
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