Clinical Trials Of Anticancer Drugs Research Articles

Survival Benefit Associated With Participation in Clinical Trials of Anticancer Drugs

Many cancer clinical investigators view clinical trials as offering better care for patients than routine clinical care. However, definitive evidence of clinical benefit from trial participation (hereafter referred to as the participation effect) has yet to emerge. To conduct a systematic review and meta-analysis of the evidence examining whether patient participation in cancer trials was associated with greater survival benefit compared with routine care. Studies were found through PubMed and Embase (January 1, 2000, until August 31, 2022), as well as backward and forward citation searching. Studies were included that compared overall survival of trial participants and routine care patients. Data extraction and methodological quality assessment were completed by 2 independent coders using Covidence software. Data were pooled using a random-effects model and analyzed based on the quality of the comparison between trial participants and routine care patients (ie, extent to which studies controlled for bias and confounders). The hazard ratio (HR) for overall survival of trial participants vs routine care patients. Thirty-nine publications were included, comprising 85 comparisons of trial participants and routine care patients. The meta-analysis revealed a statistically significant overall survival benefit for trial participants (HR, 0.76 [95% CI, 0.69-0.82]) when all studies were pooled, regardless of design or quality. However, survival benefits diminished in study subsets that matched trial participants and routine care patients for eligibility criteria (HR, 0.85 [95% CI, 0.75-0.97]) and disappeared when only high-quality studies were pooled (HR, 0.91 [95% CI, 0.80-1.05]). They also disappeared when estimates were adjusted for potential publication bias (HR, 0.94 [95% CI, 0.86-1.03]). Many studies suggest a survival benefit for cancer trial participants. However, these benefits were not detected in studies using designs addressing important sources of bias and confounding. Pooled results of high-quality studies are not consistent with a beneficial effect of trial participation on its own.

Atrial Fibrillation Incidence Associated With Exposure to Anticancer Drugs Used as Monotherapy in Clinical Trials

The incidence of atrial fibrillation (AF) associated with anticancer drugs in cancer patients remains incompletely defined. The primary outcome was the annualized incidence rate of AF reporting associated with exposure to 1 of 19 anticancer drugs used as monotherapy in clinical trials. The authors also report the annualized incidence rate of AF reported in the placebo arms of these trials. The authors systematically searched ClinicalTrials.gov for phase 2 and 3 cancer trials studying 19 different anticancer drugs of interest used as monotherapy, up to September 18, 2020. The authors performed a random-effects meta-analysis to compute summary AF annualized incidence rate with its 95% CI using log transformation and inverse variance weighting. A total of 191 clinical trials (47.1% were randomized) of 16 anticancer drugs across 26,604 patients were included. Incidence rates could be calculated for 15 drugs administered singly as monotherapy. Summary annualized incidence rates of AF reporting associated with exposure to 1 of the 15 anticancer drugs used as monotherapy were derived; these ranged from 0.26 to 4.92 per 100 person-years. The 3 highest annualized incidence rates of AF reporting were found for ibrutinib 4.92 (95% CI: 2.91-8.31), clofarabine 2.38 (95% CI: 0.66-8.55), and ponatinib 2.35 (95% CI: 1.78-3.12) per 100 person-years. Summary annualized incidence rate of AF reporting in the placebo arms was 0.25 per 100 person-years (95% CI: 0.10-0.65). AF reporting is not a rare event associated with anticancer drugs in clinical trials. A systematic and standardized AF detection should be considered in oncological trials, particularly those studying anticancer drugs associated with high AF rates. (Incidence of atrial fibrillation associated with anticancer drugs exposure in monotherapy, A safety meta-analysis of phase 2 and 3 clinical trials; CRD42020223710).

Potential target identification for osteosarcoma treatment: Gene expression re-analysis and drug repurposing

Survival rate of osteosarcoma has remained plateaued for the past three decades. New treatment is needed to improve survival rate. Drug repurposing, a method to identify new indications of previous drugs, which saves time and cost compared to the de novo drug discovery. Data mining from gene expression profile was carried out and new potential targets were identified by using drug repurposing strategy. Selected data were newly categorized as pathophysiology and metastasis groups. Data were normalized and calculated the differential gene expression. Genes with log fold change ≥ 2 and adjusted p-value ≤ 0.05 were selected as primary candidate genes (PCGs). PCGs were further enriched to determine the secondary candidate genes (SCGs) by protein interaction analysis, upstream transcription factor and related-protein kinase identification. PCGs and SCGs were further matched with gene targeted of corresponding drugs from the Drug Repurposing Hub. A total of 778 targets were identified (360 from PCGs, and 418 from SCGs). This newly identified KLHL13 is a new candidate target based on its molecular function. KLHL13 was upregulated in clinical samples. We found 256 drugs from matching processes (50anti-cancerand206non-anticancerdrugs). Clinical trials of anti-cancer drugs from 5 targets (CDK4, BCL-2, JUN, SRC, PIK3CA) are being performed for osteosarcoma treatment. Niclosamide and synthetic PPARɣ ligands are candidates for repurposing due to the possibility based on their mechanism and pharmacology properties. Re-analysis of gene expression profile could identify new potential targets, confirm a current implication, and expand the chance of repurposing drugs for osteosarcoma treatment.

Evaluation considerations for using surrogate endpoints in anticancer clinical trials

The prolongation of patient's overall survival is the accepted as gold standard to prove clinical values of anti-cancer drugs. However, if overall survival is taken as the primary endpoint in clinical trials for cancer types with a relatively good prognosis in the process of new anti-cancer drug research and development, the time to market the drugs will be prolonged due to the long follow-up time. In addition, overall survival is often interfered by confounding factors such as follow-up treatment. Therefore, regulatory agencies have established an accelerated review model using surrogate endpoints for the approval of new anti-cancer drugs, but there are still some problems in the use of surrogate endpoints in cancer clinical trials. From the perspective of new drug review, the authors expounds the key points of confirming and rationally using surrogate endpoints in clinical trials of anti-cancer drugs, which will improve the level of clinical trials of new anti-cancer drugs and accelerate the development of anti-tumor drugs.

Metallo-Drugs in Cancer Therapy: Past, Present and Future.

Cancer treatments which include conventional chemotherapy have not proven very successful in curing human malignancies. The failures of these treatment modalities include inherent resistance, systemic toxicity and severe side effects. Out of 50% patients administrated to chemotherapy, only 5% survive. For these reasons, the identification of new drug designs and therapeutic strategies that could target cancer cells while leaving normal cells unaffected still continues to be a challenge. Despite advances that have led to the development of new therapies, treatment options are still limited for many types of cancers. This review provides an overview of platinum, copper and ruthenium metal based anticancer drugs in clinical trials and in vitro/in vivo studies. Presumably, copper and ruthenium complexes have greater potential than Pt(II) complexes, showing reduced toxicity, a new mechanism of action, a different spectrum of activity and the possibility of non-cross-resistance. We focus the discussion towards past, present and future aspects.

1334P Objective response rates of placebo in randomized controlled trials of anticancer medicines: 2015 – 2019

Solid tumors may occasionally regress even without treatment, either spontaneously or as a result of placebo effect. Such spontaneous regressions or responses are intriguing from both scientific and regulatory standpoints. We conducted an updated systematic review and meta-analysis of clinical trials of anticancer drugs in advanced solid tumors to estimate an updated placebo response rate in the targeted therapy/immunotherapy era.

Serious Adverse Events Reporting in Phase III Randomized Clinical Trials of Colorectal Cancer Treatments: A Systematic Analysis.

Objective: The occurrence, development, and prognosis of serious adverse events (SAEs) associated with anticancer drugs in clinical trials have important guiding significance for real-world clinical applications. However, to date, there have been no studies investigating SAEs reporting in randomized clinical trials of colorectal cancer treatments. This article systematically reviewed the SAEs reporting of phase III randomized clinical trials of colorectal cancer treatments and analyzed the influencing factors. Methods: We reviewed all articles about phase III randomized clinical trials of colorectal cancer treatments published in the PubMed, Embase, Medline, and New England Journal of Medicine databases from January 1, 1993, to December 31, 2018, and searched the registration information of clinical trials via the internet sites such as “clinicaltrials.gov”. We analyzed the correlation between the reported proportion (RP) of SAEs in the literature and nine elements, including the clinical trial sponsor and the publication time. Chi-square tests and binary logistic regression were used to identify the factors associated with improved SAEs reports. This study was registered on PROSPERO. Results: Of 1560 articles identified, 160 were eligible, with an RP of SAEs of 25.5% (41/160). In forty-one publications reporting SAEs, only 14.6% (6/41) described the pattern of SAEs in detail. In clinical trials sponsored by pharmaceutical companies, the RP of SAEs was significantly higher than that in those sponsored by investigators (57.6 versus 20.7%, p < 0.001). From 1993 to 2018, the RP of SAEs gradually increased (none (0/6) before 2000, 17.1% (12/70) from 2000 to 2009, and 34.5% (29/84) after 2009). The average RP of SAEs published in the New England Journal of Medicine (N Engl J Med), the Lancet, the Journal of the American Medical Association (JAMA), the Lancet Oncology (Lancet Oncol), and the Journal of Clinical Oncology (J Clin Oncol) was significantly higher than that published in other journals (31.9 versus 16.7%, p = 0.030). In the clinical trials referenced by clinical guidelines, the RP of SAEs was higher than that in non-referenced clinical trials (32.0 versus 15.9%, p = 0.023). Binary logistic regression analysis showed that pharmaceutical company sponsorship, new drug research, and sample size greater than 1000 were positive influencing factors for SAEs reporting. Conclusion: Although the RP of SAEs increased over time, SAEs reporting in clinical trials needs to be further improved. The performance, outcomes and prognosis of SAEs should be reported in detail to guide clinical practice in the real world.

Mechanism Design of Health Care Blockchain System Token Economy: Development Study Based on Simulated Real-World Scenarios.

BackgroundDespite the fact that the adoption rate of electronic health records has increased dramatically among high-income nations, it is still difficult to properly disseminate personal health records. Token economy, through blockchain smart contracts, can better distribute personal health records by providing incentives to patients. However, there have been very few studies regarding the particular factors that should be considered when designing incentive mechanisms in blockchain.ObjectiveThe aim of this paper is to provide 2 new mathematical models of token economy in real-world scenarios on health care blockchain platforms.MethodsFirst, roles were set for the health care blockchain platform and its token flow. Second, 2 scenarios were introduced: collecting life-log data for an incentive program at a life insurance company to motivate customers to exercise more and recruiting participants for clinical trials of anticancer drugs. In our 2 scenarios, we assumed that there were 3 stakeholders: participants, data recipients (companies), and data providers (health care organizations). We also assumed that the incentives are initially paid out to participants by data recipients, who are focused on minimizing economic and time costs by adapting mechanism design. This concept can be seen as a part of game theory, since the willingness-to-pay of data recipients is important in maintaining the blockchain token economy. In both scenarios, the recruiting company can change the expected recruitment time and number of participants. Suppose a company considers the recruitment time to be more important than the number of participants and rewards. In that case, the company can increase the time weight and adjust cost. When the reward parameter is fixed, the corresponding expected recruitment time can be obtained. Among the reward and time pairs, the pair that minimizes the company’s cost was chosen. Finally, the optimized results were compared with the simulations and analyzed accordingly.ResultsTo minimize the company’s costs, reward–time pairs were first collected. It was observed that the expected recruitment time decreased as rewards grew, while the rewards decreased as time cost grew. Therefore, the cost was represented by a convex curve, which made it possible to obtain a minimum—an optimal point—for both scenarios. Through sensitivity analysis, we observed that, as the time weight increased, the optimized reward increased, while the optimized time decreased. Moreover, as the number of participants increased, the optimization reward and time also increased.ConclusionsIn this study, we were able to model the incentive mechanism of blockchain based on a mechanism design that recruits participants through a health care blockchain platform. This study presents a basic approach to incentive modeling in personal health records, demonstrating how health care organizations and funding companies can motivate one another to join the platform.

Combining APR-246 and HDAC-Inhibitors: A Novel Targeted Treatment Option for Neuroblastoma.

Simple SummaryPreclinical analyses identified APR-246 as a potent treatment option for neuroblastoma. However, a specific mode of action, sufficient biomarkers and promising combination partners are still missing. Here, we analyze the susceptibilities of different entities and relate them to gene expression profiles and previously described biomarkers. We propose a gene signature, consisting of 13 genes, as a novel predictive biomarker. Furthermore, we provide evidence that APR-246 directly targets metabolic weaknesses in neuroblastoma cell lines, thus hampering ROS detoxification. This makes APR-246 suitable to be combined with ROS-inducing HDAC inhibitors, a treatment combination that has not been described for neuroblastoma thus far.APR-246 (Eprenetapopt/PRIMA-1Met) is a very potent anti-cancer drug in clinical trials and was initially developed as a p53 refolding agent. As an alternative mode of action, the elevation of reactive oxygen species (ROS) has been proposed. Through an in silico analysis, we investigated the responses of approximately 800 cancer cell lines (50 entities; Cancer Therapeutics Response Portal, CTRP) to APR-246 treatment. In particular, neuroblastoma, lymphoma and acute lymphocytic leukemia cells were highly responsive. With gene expression data from the Cancer Cell Line Encyclopedia (CCLE; n = 883) and patient samples (n = 1643) from the INFORM registry study, we confirmed that these entities express low levels of SLC7A11, a previously described predictive biomarker for APR-246 responsiveness. Combining the CTRP drug response data with the respective CCLE gene expression profiles, we defined a novel gene signature, predicting the effectiveness of APR-246 treatment with a sensitivity of 90% and a specificity of 94%. We confirmed the predicted APR-246 sensitivity in 8/10 cell lines and in ex vivo cultures of patient samples. Moreover, the combination of ROS detoxification-impeding APR-246 with approved HDAC-inhibitors, known to elevate ROS, substantially increased APR-246 sensitivity in cell cultures and in vivo in two zebrafish neuroblastoma xenograft models. These data provide evidence that APR-246, in combination with HDAC-inhibitors, displays a novel potent targeted treatment option for neuroblastoma patients.

Risks and Benefits of Anticancer Drugs in Advanced Cancer Patients: A Systematic Review and Meta-Analysis

Background: Randomized clinical trials of anticancer drugs without active comparators are debated. The overall assessment of the trade-off between safety and efficacy would help to properly inform patients eligible for randomized clinical trials without active comparators. We aimed to quantify the safety and the efficacy of anticancer drugs in advanced cancer patients from randomized clinical trials without active comparators. Methods: This systematic review and meta-analysis was conducted according to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A systematic literature search of English language publications from January 1, 2000, through January 7, 2021, was performed using MEDLINE (PubMed). Eligible trials included all randomized clinical trials evaluating anticancer drugs in adult patients with advanced cancers with a control arm without any anticancer drug consisting of BSC with or without a placebo. Clinical trials performed in the adjuvant, neoadjuvant or maintenance settings were excluded, as were clinical trials evaluating anticancer drugs in combination with radiotherapy. Two authors (C.M.B. and E.C.) independently reviewed the studies for inclusion. Data from published reports were extracted by investigators, and random-effects meta-analysis was performed to estimate the overall hazard ratios (HRs) of progression-free survival (PFS) and overall survival (OS). Findings: Of 3,551 studies screened, 128 eligible trials were found involving 47,432 patients. The HRs for PFS and OS were 0•58 [95%CI: 0•53–0•63] and 0•82 [95%CI: 0•78–0•85]. The absolute excesses in all grade, severe grade III-IV, and grade V (death) adverse events between the two arms were +13•9%, 10•2%, and +0•5%. A weak correlation was measured between the excess of severe toxicity and efficacy. Interpretation: Anticancer drugs evaluated in randomized clinical trials against no active treatment benefited trial participants. Severe toxicity did not significantly correlate with efficacy. Funding: None Declaration of Interest: None

Catalase Inhibitors with Dual Pro‐Oxidant Effect as New Therapeutic Agents in Castration‐Resistant Prostate Cancer

AbstractAlmost all patients with advanced prostate cancer (PCa) will eventually progress to incurable castration‐resistant PCa (CRPC) if endocrine therapy fails. Therefore, identifying potential cellular targets is critical for the development of novel and effective treatments for CRPC. Based on the investigation of the molecular mechanism of ATN‐224, an anticancer drug in clinical trials, in CRPC DU145 cells, the antioxidant enzyme catalase (CAT) has been recognized as an actionable CRPC therapeutic target, and the modulation of intracellular redox state through CAT inhibition has great potential for CRPC treatment. After systematic design and synthesis, the benzaldehyde thiosemicarbazone derivative BT‐1 is shown to be effective CAT inhibitor in DU145 cells. This inhibition induces the significant increase of both superoxides (O2•−) and H2O2 levels in DU145 cells. Finally, the dual pro‐oxidant effect of BT‐1 is demonstrated to lead to apoptosis as well as cell‐cycle arrest in DU145 cells, effectively reducing CRPC tumors.

Spotlighting the hypoxia-centrosome amplification axis.

The abysmal success rate of anticancer drugs in clinical trials, is in part, attributable to discordance between cultured cancer cells and patient tumors. While tumors in vivo, display a lower mitotic index, patient tumors portray much higher centrosomal aberrations, relative to in vitro cultured cells. The microenvironment too differs considerably between the in vitro and in vivo scenarios. Notably, another hallmark of cancer, hypoxia, is not recapitulated in cell lines cultured under normoxic conditions. These observations raise the possibility that hypoxia may be the missing link that explains the discordance between cell biological phenomena in vitro versus physiological conditions. Further, the interplay between hypoxia and centrosome amplification (CA) is relatively understudied. Recent research from our laboratory, geared toward examining the biological link between the two, has uncovered that hypoxia induces the expression of proteins (Plk4, Aurora A, Cyclin D) implicated in CA, in a hypoxia-inducible factor1α (HIF-1α)-dependent context. Our studies evidence that hypoxia fuels CA that underlie intratumoral heterogeneity and metastatic potential of cancer cells. Given the advent of HIF-1α inhibitors, this research has ramifications in aiding patient risk stratification and designing new cancer drug therapies to facilitate clinical decision-making.

Study on cell apoptosis based on bifurcation and sensitivity analysis.

Apoptosis plays critical roles in embryonic development and adult tissue homeostasis. It has been shown that several feedback loops regulate the intrinsic pathway of apoptosis. However, it remains elusive how they coordinately modulate apoptosis. For the three modules (initiator, amplifier, and executioner) of the intrinsic pathway, we mainly studied dynamics of the initiator and the executioner modules. In this paper, we aimed to identify important regulatory processes in apoptosis through bifurcation and single-parameter sensitivity analysis. We found that modules or feedback loops but not specific parameters determine the network functions. More exactly, the activity of BH3 plays a more important role in the initiator module and triggers the amplifier module. In addition, aC9 autocrine expression and C9/XIAP feedback loop are more sensitive in executioner module. We also found that three feedback loops respectively including BH3AC/BH3DR, MDM2/ARF/ASPP and p53helper/p53killer play more important roles in cell fate decisions after DNA damage. Our research provides a rational basis for the design of clinical trials of anticancer drugs.

Effects of the NEDD8-Activating Enzyme Inhibitor MLN4924 on Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus.

ABSTRACTThe switch of Kaposi's sarcoma-associated herpesvirus (KSHV) from latency to lytic replication is a key event for viral dissemination and pathogenesis. MLN4924, a novel neddylation inhibitor, reportedly causes the onset of KSHV reactivation but impairs later phases of the viral lytic program in infected cells. Thus far, the molecular mechanism involved in the modulation of the KSHV lytic cycle by MLN4924 is not yet fully understood. Here, we confirmed that treatment of different KSHV-infected primary effusion lymphoma (PEL) cell lines with MLN4924 substantially induces viral lytic protein expression. Due to the key role of the virally encoded ORF50 protein in the latent-to-lytic switch, we investigated its transcriptional regulation by MLN4924. We found that MLN4924 activates the ORF50 promoter (ORF50p) in KSHV-positive cells (but not in KSHV-negative cells), and the RBP-Jκ-binding elements within the promoter are critically required for MLN4924 responsiveness. In KSHV-negative cells, reactivation of the ORF50 promoter by MLN4924 requires the presence of the latency-associated nuclear antigen (LANA). Under such a condition, LANA acts as a repressor to block the ORF50p activity, whereas MLN4924 treatment relieves LANA-mediated repression. Importantly, we showed that LANA is a neddylated protein and can be deneddylated by MLN4924. On the other hand, we revealed that MLN4924 exhibits concentration-dependent biphasic effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)- or sodium butyrate (SB)-induced viral reactivation in PEL cell lines. In other words, low concentrations of MLN4924 promote activation of TPA- or SB-mediated viral reactivation, whereas high concentrations of MLN4924, conversely, inhibit the progression of TPA- or SB-mediated viral lytic program.IMPORTANCE MLN4924 is a neddylation (NEDD8 modification) inhibitor, which currently acts as an anti-cancer drug in clinical trials. Although MLN4924 has been reported to trigger KSHV reactivation, many aspects regarding the action of MLN4924 in regulating the KSHV lytic cycle are not fully understood. Since the KSHV ORF50 protein is the key regulator of viral lytic reactivation, we focus on its transcriptional regulation by MLN4924. We here show that activation of the ORF50 gene by MLN4924 involves the relief of LANA-mediated transcriptional repression. Importantly, we find that LANA is a neddylated protein. To our knowledge, this is the first report showing that neddylation occurs in viral proteins. Additionally, we provide evidence that different concentrations of MLN4924 have opposite effects on TPA-mediated or SB-mediated KSHV lytic cycle activation. Therefore, in clinical application, we propose that MLN4924 needs to be used with caution in combination therapy to treat KSHV-positive subjects.

Non-benzoquinone geldanamycin analogs trigger various forms of death in human breast cancer cells.

BackgroundHsp90 proteins are important therapeutic targets for many anti-cancer drugs in clinical trials. Geldanamycin (GA) was identified as the first natural inhibitor of Hsp90, increasing evidence suggests that GA was not a good choice for clinical trials. In this study, we investigated two new non-benzoquinone geldanamycin analogs of Hsp90 inhibitors, DHQ3 and 17-demethoxy-reblastatin (17-DR), to explore the molecular mechanisms of their anti-cancer activity in vivo and vitro.MethodsMTT and colony formation assays were used to measure cell viability. Flow cytometry, DAPI staining, ATP assay, electron microscopy, western blots, siRNAs transfection and immunofluorescence were used to determine the molecular mechanism of DHQ3- or 17-DR-induced different forms of death in human breast cancer MDA-MB-231 cells. Malachite green reagent was used to measure ATPase activity of the analogs.ResultsDHQ3 and 17-DR presented efficiently inhibitory effect in MDA-MB-231 cell lines, and DHQ3 induced necroptosis by activation of the RIP1-RIP3-MLKL necroptosis cascade. And DHQ3-induced cell death was inhibited by a necroptosis inhibitor, necrostatin-1 (Nec-1), but not by a caspase inhibitor z-VAD-fmk. On the other hand, 17-DR induced apoptosis in MDA-MB-231 cells, indicating a caspase-dependent killing mechanism. We further demonstrated that down-regulation of RIP1 and RIP3 by siRNA protected against DHQ3 but not 17-DR induced cell death. These results were confirmed by electron microscopy. DHQ3 and 17-DR induced the degradation of Hsp90 client proteins, and they showed strong antitumor effects in MDA-MB-231 cell-xenografted nude mice.ConclusionsThese findings supported that DHQ3 and 17-DR induce different forms of death in some cancer cell line via activation of different pathways. All of the results provided evidence for its anti-tumorigentic action with low hepatotoxicity in vivo, making them promising anti-breast cancer agents.

Abstract B71: DEN-50R - establishment of a novel and unique cell line based drug screening platform for cancer treatment

Abstract Today, chemotherapy and molecularly targeted therapies are the main therapeutic options in cancer treatment, but their effectiveness is limited by drug resistance, a major problem facing current cancer research. Since its establishment in the late 1980s, the NCI60 cell line panel has generated tremendous value, economic as well as societal, by contributing to the identification of mechanisms of drug action. This information, in turn, has been used to create new anti-cancer drugs for the benefit of patients. However, the cell lines comprised in the NCI60 panel are mostly derived from treatment of chemo-naïve patients (no medical treatment). Since early clinical trials of anti-cancer drugs most often recruit patients who have failed several different prior treatments, there is a need to develop a platform that builds on the concept underlying the NCI60 cell line panel and extend it to allow testing of potential new drugs in the setting of drug resistance. Moreover, it is also well-known that molecular drug resistance mechanisms might first appear following drug exposure and access to panels of matched drug-sensitive and drug-resistant isogenic cell lines, is thus mandatory for studying the underlying mechanisms of acquired drug resistance. We have initiated the establishment of DEN-50R, a novel and unique cell line-based drug screening platform within cancer treatment. The platform will, when fully developed, consist of human cancer cell lines representing the five most common cancer forms (colorectal, prostate, lung, breast cancer and malignant melanoma) and matched drug-resistant sublines for each of the five cancer forms. In a second phase additional cancer forms will be included. Resistance is developed against drugs and drug combinations currently used in the clinic, and with the introduction of novel drugs and regimens, new corresponding resistant sublines will be generated. All pairs of sensitive and resistant cell lines are thoroughly characterized with regard to cross-resistance to other drugs as well as to genomics, epigenomics, transcriptomics, and proteomics profiling. All data generated with the DEN-50R platform will be placed in the new National Danish Life Science Supercomputer with secure, regulated access providing a unique and innovative integrative analysis resource for academic, clinical and industrial researchers involved in anti-cancer drug development and cancer diagnostics at both pre-clinical and clinical levels. We envision that the DEN-50R be used to: • Test novel chemical entities for anti-cancer effects, including potential lack of cross-resistance thereby facilitating selection of analogs for further preclinical and clinical testing. • Test already known drugs for potential effects in drug resistant cell lines facilitating “repurposing” of drugs. • Reveal novel molecular drug resistant mechanisms allowing for targeted development of new drug entities that can circumvent drug resistance • identify novel predictive biomarkers for the most common drug entities further facilitating a personalized treatment approach. Citation Format: Jan Stenvang, Jose Moreira, Niels Frank Jensen, Signe Lykke Nielsen, Torben Orntoft, Ulrik Lassen, Cathrine Nordgaard, Stine Ninel Hansen, Haatisha Jandu, Anna Vind, Maria Andreasen, Camilla Cederbye, Julie Noer, Thiago Lima, Birgitte Martine Viuff, Soeren Brunak, Thomas Skoet Jensen, Peter Buhl Jensen, Joergen Drejer, Henrik Ditzel, Nils Brünner. DEN-50R - establishment of a novel and unique cell line based drug screening platform for cancer treatment. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B71.

Repressed Ca2+ clearance in parthenolide-treated murine brain bEND.3 endothelial cells

Parthenolide is a sesquiterpene lactone compound isolated from the leaves and flowerheads of the plant feverfew (Tanacetum parthenium). The anticancer effects of parthenolide have been well studied and this lactone compound is currently under clinical trials. Parthenolide is also a protective agent in cardiac reperfusion injury via its inhibition of nuclear factor-κB (NF-κB). Not much is known if this compound affects signal transduction in non-tumor cells. We investigated whether parthenolide affected Ca2+ signaling in endothelial cells, key components in regulating the vascular tone. In this work using mouse cortical microvascular bEND.3 endothelial cells, we found that a 15-h treatment with parthenolide resulted in amplified ATP-triggered Ca2+ signal; the latter had a very slow decay rate suggesting suppression of Ca2+ clearance. Evidence suggests parthenolide suppressed Ca2+ clearance by inhibiting the plasmalemmal Ca2+ pump; such suppression did not result from decreased expression of the plasmalemmal Ca2+ pump protein. Rather, such suppression was possibly a consequence of endoplasmic reticulum (ER) stress, since salubrinal (an ER stress protector) was able to alleviate parthenolide-induced Ca2+ clearance suppression. Given the current deployment of parthenolide as an anti-cancer drug in clinical trials and the potential usage of this lactone as a cardioprotectant, it is important to examine in details the perturbing effects of parthenolide on Ca2+ homeostasis in endothelial cells and neighboring vascular smooth muscle cells, activities of which exert profound effects on hemodynamics.

Consequences of passages: Mitotic indices and centrosome amplification levels variance between patients’ tumors and cancer cells cultured in vitro.

e13518 Background: The correct choice of preclinical model is absolutely vital for the success of anticancer drugs in clinical trials. Recently, mitosis-targeting drugs performed dismally in human ...

Neddylation promotes ubiquitylation and release of Ku from DNA-damage sites.

SummaryThe activities of many DNA-repair proteins are controlled through reversible covalent modification by ubiquitin and ubiquitin-like molecules. Nonhomologous end-joining (NHEJ) is the predominant DNA double-strand break (DSB) repair pathway in mammalian cells and is initiated by DSB ends being recognized by the Ku70/Ku80 (Ku) heterodimer. By using MLN4924, an anti-cancer drug in clinical trials that specifically inhibits conjugation of the ubiquitin-like protein, NEDD8, to target proteins, we demonstrate that NEDD8 accumulation at DNA-damage sites is a highly dynamic process. In addition, we show that depleting cells of the NEDD8 E2-conjugating enzyme, UBE2M, yields ionizing radiation hypersensitivity and reduced cell survival following NHEJ. Finally, we demonstrate that neddylation promotes Ku ubiquitylation after DNA damage and release of Ku and Ku-associated proteins from damage sites following repair. These studies provide insights into how the NHEJ core complex dissociates from repair sites and highlight its importance for cell survival following DSB induction.

Sensitization of cancer cells through reduction of total Akt and downregulation of salinomycin-induced pAkt, pGSk3β, pTSC2, and p4EBP1 by cotreatment with MK-2206.

MK-2206 is an inhibitor of Akt activation. It has been investigated as an anticancer drug in clinical trials assessing the potential of pAkt targeting therapy. The purpose of this study was to identify conditions that increase the sensitivity of cancer cells to MK-2206. We found that the treatment of cancer cells with a high concentration of salinomycin (Sal) reduced total Akt protein levels but increased activated Akt levels. When cancer cells were cotreated with MK-2206 and Sal, both pAkt and total Akt levels were reduced. Using microscopic observation, an assessment of cleaved PARP, FACS analysis of pre-G1 region, and Hoechst staining, we found that Sal increased apoptosis of MK-2206-treated cancer cells. These results suggest that cotreatment with MK-2206 and Sal sensitizes cancer cells via reduction of both pAkt and total Akt. Furthermore, cotreatment of cancer cells with Sal and MK-2206 reduced pp70S6K, pmTOR, and pPDK1 levels. In addition, Sal-induced activation of GSK3β, TSC2, and 4EBP1 was abolished by MK-2206 cotreatment. These results suggest that cotreatment using MK-2206 and Sal could be used as a therapeutic method to sensitize cancer cells through targeting of the PI3K/Akt/mTOR pathway. Our findings may contribute to the development of MK-2206-based sensitization therapies for cancer patients.