Inhibition of Aurora B kinase (AURKB) enhances the effectiveness of 5-fluorouracil chemotherapy against colorectal cancer cells.

BACKGROUND: 5-Fluorouracil (5-FU) remains a core component of systemic therapy for colorectal cancer (CRC). However, response rates remain low, and development of therapy resistance is a primary issue. Combinatorial strategies employing a second agent to augment the therapeutic effect of chemotherapy is predicted to reduce the incidence of treatment resistance and increase the durability of response to therapy. METHODS: Here, we employed quantitative proteomics approaches to identify novel druggable proteins and molecular pathways that are deregulated in response to 5-FU, which might serve as targets to improve sensitivity to chemotherapy. Drug combinations were evaluated using 2D and 3D CRC cell line models and an ex vivo culture model of a patient-derived tumour. RESULTS: Quantitative proteomics identified upregulation of the mitosis-associated protein Aurora B (AURKB), within a network of upregulated proteins, in response to a 24 h 5-FU treatment. In CRC cell lines, AURKB inhibition with the dihydrogen phosphate prodrug AZD1152, markedly improved the potency of 5-FU in 2D and 3D in vitro CRC models. Sequential treatment with 5-FU then AZD1152 also enhanced the response of a patient-derived CRC cells to 5-FU in ex vivo cultures. CONCLUSIONS: AURKB inhibition may be a rational approach to augment the effectiveness of 5-FU chemotherapy in CRC.

Correction: Inhibition of thioredoxin 1 leads to apoptosis in drug-resistant multiple myeloma.

[This corrects the article DOI: 10.18632/oncotarget.3795.].

Hepatocyte-specific deletion of peroxisomal protein PEX13 results in disrupted iron homeostasis.

Peroxisomes are organelles, abundant in the liver, involved in a variety of cellular functions, including fatty acid metabolism, plasmalogen synthesis and metabolism of reactive oxygen species. Several inherited disorders are associated with peroxisomal dysfunction; increasingly many are associated with hepatic pathologies. The liver plays a principal role in regulation of iron metabolism. In this study we examined the possibility of a relationship between iron homeostasis and peroxisomal integrity. We examined the effect of deleting Pex13 in mouse liver on systemic iron homeostasis. We also used siRNA-mediated knock-down of PEX13 in a human hepatoma cell line (HepG2/C3A) to elucidate the mechanisms of PEX13-mediated regulation of hepcidin. We demonstrate that transgenic mice lacking hepatocyte Pex13 have defects in systemic iron homeostasis. The ablation of Pex13 expression in hepatocytes leads to a significant reduction in hepatic hepcidin levels. Our results also demonstrate that a deficiency of PEX13 gene expression in HepG2/C3A cells leads to decreased hepcidin expression, which is mediated through an increase in the signalling protein SMAD7, and endoplasmic reticulum (ER) stress. This study identifies a novel role for a protein involved in maintaining peroxisomal integrity and function in iron homeostasis. Loss of Pex13, a protein important for peroxisomal function, in hepatocytes leads to a significant increase in ER stress, which if unresolved, can affect liver function. The results from this study have implications for the management of patients with peroxisomal disorders and the liver-related complications they may develop.

What Defense Mechanisms Do Therapists Interpret In-Session?

One of the key technical guidelines outlined by psychodynamic theorists and clinicians is for therapists to interpret a patient's most prominent defenses (Greenson, 1967; Langs, 1973). However, a debate exists about what constitutes a patient's most prominent defense and which defenses therapists actually choose to interpret in-session. This study aimed to shed light on this debate by examining 35 psychotherapy sessions (18 high alliance and 17 low alliance dyads) of individuals in therapy at a university counselling center. The analysis focused on comparing the patients' most prominent defenses and the range of defenses they utilized, and the therapists' most prominent interpretation level as well as the range of interpretation level. Paired sample t-tests showed no significant mean difference between sessions with low and high alliance scores in patient defense levels (e.g., frequency and range) and therapist interpretation levels (e.g., frequency and range). Significant differences were found between the range of patient defense levels and the range of therapist interpretation levels. Correlational analyses showed no significant relationship between patient defense levels and therapist interpretation levels on both the frequency and range levels. Clinical implications of these results, and directions for future research are discussed.

Expression of the thioredoxin system in an in vivo-like cancer cell environment upon auranofin treatment.

As essential elements of the tumor microenvironment, the variable oxygenation state of the tumor tissue, the extracellular matrix (ECM) and different cell types are important determinants of carcinogenesis. These elements may also influence how tumor cells respond to therapeutic treatments. In the present study, we assessed the anti-cancer activity of auranofin and its effect on the thioredoxin (Trx) system under conditions that closely resemble the in vivo tumor microenvironment with respect to the oxygen levels and tissue architecture. We utilised an oxygen scheme involving growth of cancer cells under normoxia (20%) and hypoxia (0.1%). We also preconditioned cells with intermittent hypoxia (IH) prior to a prolonged hypoxic incubation. This oxygen scheme did not affect the cytotoxicity of auranofin; however, IH preconditioned cells were less sensitive towards the inhibition of thioredoxin reductase (TrxR) specific activity upon treatment with auranofin. IH preconditioning also upregulated Trx protein levels in auranofin treated cells. We also compared the activity of auranofin against cancer cells cultured in 2D monolayer and 3D spheroid-based culture models. Auranofin was less potent against cells grown under a more in vivo-like 3D environment. The results presented in this paper implicate the importance of the tumor oxygen environment and tissue architecture in influencing the response of cancer cells towards auranofin.

The thioredoxin system in breast cancer cell invasion and migration.

Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.

An Empirical Investigation of Defense Interpretation Depth, Defensive Functioning, and Alliance Strength in Psychodynamic Psychotherapy.

The present study examined the relationship between depth of defense interpretations by therapists, and patient defensive functioning, on the therapeutic alliance in a sample of 36 patients undergoing short-term dynamic psychotherapy. Defense interpretation depth was defined as the degree to which therapist interpretations contained information regarding the motivation for patient defenses and historical origins of the defensive processes (Greensen, 1967). Mean depth of interpretation was compared between sessions that were identified beforehand as either high-alliance or low-alliance sessions using the Helping Alliance Questionnaire (HAq-II: Luborsky et al., 1996). Results indicated that defensive functioning was correlated to defense interpretation depth in low-alliance sessions. Moreover, mean depth of interpretation was also higher in low-alliance sessions, pointing to the possible "destabilizing" effects that these interpretations may have on both defensive functioning and the therapeutic alliance. These results are discussed within the context of previous studies of therapeutic technique in dynamic psychotherapy.

Inhibition of thioredoxin 1 leads to apoptosis in drug-resistant multiple myeloma.

Multiple myeloma (MM) is a hematological malignancy characterized by the aberrant accumulation of clonal plasma cells in the bone marrow. Despite recent advancement in anti-myeloma treatment, MM remains an incurable disease. This study showed higher intrinsic oxidative stress and higher Trx1 and TrxR1 protein levels in MM cells compared to normal cells. Drug-induced Trx1 (PX-12) and TrxR1 (Auranofin) inhibition disrupted redox homeostasis resulting in ROS-induced apoptosis in MM cells and a reduction in clonogenic activity. Knockdown of either Trx1 or TrxR1 reduced MM cell viability. Trx1 inhibition by PX-12 sensitized MM cells to undergo apoptosis in response to the NF-κß inhibitors, BAY 11-7082 and curcumin. PX-12 treatment decreased the expression of the NF-κß subunit p65 in MM cells. Bortezomib-resistant MM cells contained higher Trx1 protein levels compared to the parental cells and PX-12 treatment resulted in apoptosis. Thus, increased Trx1 enhances MM cell growth and survival and exerts resistance to NF-κß inhibitors. Therefore inhibiting the thioredoxin system may be an effective therapeutic strategy to treat newly diagnosed as well as relapsed/refractory MM.

Learning how to rate video-recorded therapy sessions: a practical guide for trainees and advanced clinicians.

Watching and rating psychotherapy sessions is an important yet often overlooked component of psychotherapy training. This article provides a simple and straightforward guide for using one Website (www.ATOStrainer.com) that provides an automated training protocol for rating of psychotherapy sessions. By the end of the article, readers will be able to have the knowledge to go to the Website and begin using this training method as soon as they have a recorded session to view. This article presents, (a) an overview of the Achievement of Therapeutic Objectives Scale (ATOS; McCullough et al., 2003a), a research tool used to rate psychotherapy sessions; (b) a description of APA training tapes, available for purchase from APA Books, that have been rated and scored by ATOS trained clinicians and posted on the Website; (c) step-by-step procedures on how ratings can be done; (d) an introduction to www.ATOStrainer.com where ratings can be entered and compared with expert ratings; and (e) first-hand personal experiences of the authors using this training method and the benefits it affords both trainees and experienced therapists. This psychotherapy training Website has the potential to be a key resource tool for graduate students, researchers, and clinicians. Our long-range goal is to promote the growth of our understanding of psychotherapy and to improve the quality of psychotherapy provided for patients.

Therapists' perception of benefits and costs of using virtual reality treatments.

Research indicates that virtual reality is effective in the treatment of many psychological difficulties and is being used more frequently. However, little is known about therapists' perception of the benefits and costs related to the use of virtual therapy in treatment delivery. In the present study, 271 therapists completed an online questionnaire that assessed their perceptions about the potential benefits and costs of using virtual reality in psychotherapy. Results indicated that therapists perceived the potential benefits as outweighing the potential costs. Therapists' self-reported knowledge of virtual reality, theoretical orientation, and interest in using virtual reality were found to be associated with perceptual measures. These findings contribute to the current knowledge of the perception of virtual reality amongst psychotherapists.