Kenneth R. Evans

EMT transcription factors snail and slug directly contribute to cisplatin resistance in ovarian cancer

BackgroundThe epithelial to mesenchymal transition (EMT) is a molecular process through which an epithelial cell undergoes transdifferentiation into a mesenchymal phenotype. The role of EMT in embryogenesis is well-characterized and increasing evidence suggests that elements of the transition may be important in other processes, including metastasis and drug resistance in various different cancers.MethodsAgilent 4 × 44 K whole human genome arrays and selected reaction monitoring mass spectrometry were used to investigate mRNA and protein expression in A2780 cisplatin sensitive and resistant cell lines. Invasion and migration were assessed using Boyden chamber assays. Gene knockdown of snail and slug was done using targeted siRNA. Clinical relevance of the EMT pathway was assessed in a cohort of primary ovarian tumours using data from Affymetrix GeneChip Human Genome U133 plus 2.0 arrays.ResultsMorphological and phenotypic hallmarks of EMT were identified in the chemoresistant cells. Subsequent gene expression profiling revealed upregulation of EMT-related transcription factors including snail, slug, twist2 and zeb2. Proteomic analysis demonstrated up regulation of Snail and Slug as well as the mesenchymal marker Vimentin, and down regulation of E-cadherin, an epithelial marker. By reducing expression of snail and slug, the mesenchymal phenotype was largely reversed and cells were resensitized to cisplatin. Finally, gene expression data from primary tumours mirrored the finding that an EMT-like pathway is activated in resistant tumours relative to sensitive tumours, suggesting that the involvement of this transition may not be limited to in vitro drug effects.ConclusionsThis work strongly suggests that genes associated with EMT may play a significant role in cisplatin resistance in ovarian cancer, therefore potentially leading to the development of predictive biomarkers of drug response or novel therapeutic strategies for overcoming drug resistance.

Amphetamine- and morphine-induced feeding: Evidence for involvement of reward mechanisms

The present study examined the possibility that the increased feeding found following central and peripheral administrations of low doses of d-amphetamine (AMP) and morphine (MOR) may involve central reward mechanisms. In order to examine this possibility, the effects of these drugs on food selection and intake of foods that varied in palatability and nutritive content were determined. In addition, the importance of the nucleus accumbens (ACB), a critical structure for AMP and MOR reward, in these effects was determined. Results indicated that MOR increased the intake of preferred food regardless of nutritive content. In contrast, AMP was most effective at increasing the intake of preferred foods which contained carbohydrates. These effects were observed following systematic or intra-ACB administration of low doses of MOR and AMP. Together these findings implicate reward mechanisms in the expression of MOR- and AMP-induced feeding. It is further suggested that the feeding effects of MOR and AMP can be differentiated in paradigms where animals have a choice of several foods which may vary in palatability and/or nutritive content. The relevance of the present findings for our understanding of which elements of food and feeding behavior are coupled with ACB reward signals is also discussed.

Reliability and Validity of the Sexual Interest and Desire Inventory–Female (SIDI-F), a Scale Designed to Measure Severity of Female Hypoactive Sexual Desire Disorder

The Sexual Interest and Desire Inventory–Female (SIDI-F) is a 13-item scale developed as a clinician-administered assessment tool to quantify the severity of symptoms in women diagnosed with hypoactive sexual desire disorder (HSDD). The present investigation assessed the reliability and validity of the SIDI-F as a measure of HSDD severity. Results show that the SIDI-F exhibits excellent internal consistency, with Cronbachs alpha of 0.9. The validity of the SIDI-F as a measure of HSDD severity was confirmed by a number of observations. Women with a clinical diagnosis (Diagnostic and Statistical Manual of Mental Disorders [DSM-IV-TR; American Psychiatric Association, 2000]) of HSDD had significantly lower SIDI-F scores than women not meeting diagnostic criteria for any subtype of female sexual dysfunction and women diagnosed with female orgasmic disorder. There was a high correlation between scores on the SIDI-F and scores on the Female Sexual Function Index (FSFI; Rosen et al., 2000) and an interactive voice response version of the Changes in Sexual Functioning Questionnaire (CSFQ; Clayton, McGarvey, & Clavet, 1997; Clayton, McGarvey, Clavet, & Piazza, 1997), two validated measures that assess general female sexual dysfunction. In contrast, there was a poor correlation between SIDI-F scores and scores on a slightly modified Marital Adjustment Scale (Locke, Wallace, 1959; MAS), an assessment of general (nonsexual) relationship satisfaction. Taken together, the results of the present investigation indicate that the SIDI-F is a reliable and valid measure of HSDD severity, independent of relationship issues.

Intra-nucleus accumbens amphetamine: Dose-dependent effects on food intake

The effects of microinjections into the nucleus accumbens (N.ACC.) of 0.0, 2.0 or 8.0 micrograms of (+)-amphetamine sulphate (AMPH) on food intake and running wheel activity were examined. The 2.0 micrograms dose of AMPH produced increased food intake while 8.0 micrograms significantly decreased food intake. No effect was found on running wheel activity with the 2.0 micrograms dose, though 8.0 micrograms significantly increased the number of wheel revolutions with respect to the saline group. Results were interpreted to suggest that the N.ACC. may be an important site in the mediation of the increased food intake noted with low doses of psychomotor stimulants.

Proteomic Analyses Reveal High Expression of Decorin and Endoplasmin (HSP90B1) Are Associated with Breast Cancer Metastasis and Decreased Survival

Background Breast cancer is the most common malignancy among women worldwide in terms of incidence and mortality. About 10% of North American women will be diagnosed with breast cancer during their lifetime and 20% of those will die of the disease. Breast cancer is a heterogeneous disease and biomarkers able to correctly classify patients into prognostic groups are needed to better tailor treatment options and improve outcomes. One powerful method used for biomarker discovery is sample screening with mass spectrometry, as it allows direct comparison of protein expression between normal and pathological states. The purpose of this study was to use a systematic and objective method to identify biomarkers with possible prognostic value in breast cancer patients, particularly in identifying cases most likely to have lymph node metastasis and to validate their prognostic ability using breast cancer tissue microarrays. Methods and Findings Differential proteomic analyses were employed to identify candidate biomarkers in primary breast cancer patients. These analyses identified decorin (DCN) and endoplasmin (HSP90B1) which play important roles regulating the tumour microenvironment and in pathways related to tumorigenesis. This study indicates that high expression of Decorin is associated with lymph node metastasis (p<0.001), higher number of positive lymph nodes (p<0.0001) and worse overall survival (p = 0.01). High expression of HSP90B1 is associated with distant metastasis (p<0.0001) and decreased overall survival (p<0.0001) these patients also appear to benefit significantly from hormonal treatment. Conclusions Using quantitative proteomic profiling of primary breast cancers, two new promising prognostic and predictive markers were found to identify patients with worse survival. In addition HSP90B1 appears to identify a group of patients with distant metastasis with otherwise good prognostic features.

The Canadian Biomarker Integration Network in Depression (CAN-BIND): Advances in Response Prediction

Identifying biological and clinical markers of treatment response in depression is an area of intense research that holds promise for increasing the efficiency and efficacy of resolving a major depressive episode and preventing future episodes. Collateral benefits include decreased healthcare costs and increased workplace productivity. Despite research advances in many areas, efforts to identify biomarkers have not revealed any consistently validated candidates. Studies of clinical characteristics, genetic, neuroimaging, and various biochemical markers have all shown promise in discrete studies, but these findings have not translated into a personalized medicine approach to treating individual patients in the clinic. We propose that an integrated study of a range of biomarker candidates from across different modalities is required. Furthermore, advanced mathematical modeling and pattern recognition methods are required to detect important biological signatures associated with treatment outcome. Through an informatics-based integration of the various clinical, molecular and imaging parameters that are known to be important in the pathophysiology of depression, it becomes possible to encompass the complexity of contributing factors and phenotypic presentations of depression, and identify the key signatures of treatment response.

Effects of d- and l-amphetamine on food intake: Evidence for a dopaminergic substrate

The present experiment examined the effects of d- and l-amphetamine on the intake of sugar, sweetened rat chow and unsweetened rat chow in free feeding rats. Rats were injected IP with 4 doses of d- or l-amphetamine (0.0, 0.125, 0.50 and 2.00 mg/kg). Regardless of drug condition, animals were found to prefer sugar over sweetened or unsweetened chow. d-Amphetamine significantly increased food intake at 0.125 and 0.50 mg/kg doses but not at 2.00 mg/kg. l-Amphetamine had no significant effects at any dose. Further, d-amphetamine significantly increased sugar intake but not sweetened or unsweetened chow. Since d- and l-amphetamine are equipotent at releasing noradrenaline, while d-amphetamine is 2 to 5 times more potent at releasing dopamine, the results suggest that d-amphetamine-induced feeding is associated with activation of a dopaminergic substrate.

Identification of the IGF1/PI3K/NF κB/ERK gene signalling networks associated with chemotherapy resistance and treatment response in high-grade serous epithelial ovarian cancer

BackgroundResistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression profiling to delineate major deregulated pathways and biomarkers associated with the development of intrinsic chemotherapy resistance upon exposure to standard first-line therapy for ovarian cancer.MethodsThe study cohort comprised 28 patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. All 28 patients had advanced stage, high-grade serous ovarian cancer, and were treated with standard platinum-based chemotherapy. Twelve patient tumours demonstrating relative resistance to platinum chemotherapy corresponding to shorter PFS (< eight months) were compared to sixteen tumours from platinum-sensitive patients (PFS > eighteen months). Whole transcriptome profiling was performed using an Affymetrix high-resolution microarray platform to permit global comparisons of gene expression profiles between tumours from the resistant group and the sensitive group.ResultsMicroarray data analysis revealed a set of 204 discriminating genes possessing expression levels which could influence differential chemotherapy response between the two groups. Robust statistical testing was then performed which eliminated a dependence on the normalization algorithm employed, producing a restricted list of differentially regulated genes, and which found IGF1 to be the most strongly differentially expressed gene. Pathway analysis, based on the list of 204 genes, revealed enrichment in genes primarily involved in the IGF1/PI3K/NF κB/ERK gene signalling networks.ConclusionsThis study has identified pathway specific prognostic biomarkers possibly underlying a differential chemotherapy response in patients undergoing standard platinum-based treatment of serous epithelial ovarian cancer. In addition, our results provide a pathway context for further experimental validations, and the findings are a significant step towards future therapeutic interventions.

MicroRNA Signature Helps Distinguish Early from Late Biochemical Failure in Prostate Cancer

PURPOSE Prostate-specific antigen testing has led to overtreatment of prostate cancer (PCa). Only a small subset of PCa patients will have an aggressive disease that requires intensive therapy, and there is currently no biomarker to predict disease aggressiveness at the time of surgery. MicroRNAs (miRNAs) are reported to be involved in PCa pathogenesis. METHODS This study involved 105 participants. For the discovery phase, prostatectomy samples were dichotomized to high-risk (n = 27, biochemical failure <36 months after prostatectomy) and low-risk groups (n = 14, ≥ 36 months without biochemical failure). Expression of 754 mature miRNAs was compared between the 2 groups. Linear regression models were built to accurately predict biochemical failure risk. miRNA mimics were transfected into PCa model cell lines to test effects on proliferation and to deduce responding signaling pathways. RESULTS We identified 25 differentially expressed miRNAs between the biochemical failure risk groups. Based on the expression of 2-3 miRNAs, 3 logistic regression models were developed, each with a high positive predictive value. Candidate miRNAs and the best-performing model were also verified on an independent PCa set. miRNA-152, featured in the models, was further investigated by using cell line models and was shown to affect cell proliferation. Predicted interaction between miR-152 and (mRNA)ERBB3 (erythroblastic leukemia viral oncogene homolog 3) was experimentally validated in vitro. CONCLUSIONS miRNAs can help to predict biochemical failure risk at the time of prostatectomy.

Rating the raters: Assessing the quality of Hamilton Rating Scale for depression clinical interviews in two industry-sponsored clinical drug trials

Objective: The quality of clinical interviews conducted in industry-sponsored clinical drug trials is an important but frequently overlooked variable that may influence the outcome of a study. We evaluated the quality of Hamilton Rating Scale for Depression (HAM-D) clinical interviews performed at baseline in 2 similar multicenter, randomized, placebo-controlled depression trials sponsored by 2 pharmaceutical companies. Methods: A total of 104 audiotaped HAM-D clinical interviews were evaluated by a blinded expert reviewer for interview quality using the Rater Applied Performance Scale (RAPS). The RAPS assesses adherence to a structured interview guide, clarification of and follow-up to patient responses, neutrality, rapport, and adequacy of information obtained. Results: HAM-D interviews were brief and cursory and the quality of interviews was below what would be expected in a clinical drug trial. Thirty-nine percent of the interviews were conducted in 10 minutes or less, and most interviews were rated fair or unsatisfactory on most RAPS dimensions. Conclusions: Results from our small sample illustrate that the clinical interview skills of raters who administered the HAM-D were below what many would consider acceptable. Evaluation and training of clinical interview skills should be considered as part of a rater training program.