Triple-negative breast carcinomas of low malignant potential: review on diagnostic criteria and differential diagnoses.

Triple-negative breast carcinomas constitute a wide spectrum of lesions, mostly being highly aggressive. Nevertheless, some special histologic subtypes can have low malignant potential. The purpose of the present paper is to review diagnostic criteria and prognostic parameters of breast neoplasms of special histotypes. Specifically, adenoid cystic carcinoma, adenomyoepithelioma, acinic cell carcinoma, mucoepidermoid carcinoma, tall cell carcinoma with reverse polarity, and secretory carcinoma will be discussed. For each tumour, definition and morphological and molecular features, together with prognostic parameters, will be presented. Paradigmatic cases will be illustrated.

Propofol infusions using a human target controlled infusion (TCI) pump in chimpanzees (Pan troglodytes).

Chimpanzees are genetically and physiologically similar to humans. Several pharmacokinetic models of propofol are available and target controlled infusion (TCI) of propofol is established in humans, but not in chimpanzees. The purpose of this study was to investigate if human pharmacokinetic models can accurately predict propofol plasma concentration (Cp) in chimpanzees and if it is feasible to perform TCI in chimpanzees. Ten chimpanzees were anaesthetized for regular veterinary examinations. Propofol was used as an induction or maintenance agent. Blood samples were collected from a catheter in a cephalic vein at 3-7 time points between 1 and 100 min following the propofol bolus and/or infusion in five chimpanzees, or TCI in six chimpanzees. Cp was measured using high-performance liquid chromatography. The Marsh, Schnider and Eleveld human pharmacokinetic models were used to predict Cp for each case and we examined the predictive performances of these models using the Varvel criteria Median PE and Median APE. Median PE and Median APE for Marsh, Schnider and Eleveld models were within or close to the acceptable range. A human TCI pump was successfully maintained propofol Cp during general anesthesia in six chimpanzees. Human propofol pharmacokinetic models and TCI pumps can be applied in chimpanzees.

Evaluation of epithelial and mesenchymal cell markers in canine urinary bladder transitional cell carcinoma.

Canine transitional cell carcinoma (cTCC) is the most common malignant tumour in the urinary bladder: it is highly invasive and exhibits metastatic characteristics. Inflammation is also strongly related to cTCC. Epithelial tumours often exhibit a mesenchymal cell phenotype during tumour invasion and metastasis owing to epithelial-mesenchymal transition (EMT), which is often induced in chronic inflammation. The aim of this retrospective study was to investigate the expression of epithelial and mesenchymal cell markers in tumour cells and to evaluate its relationship with prognosis of cTCC. In this study, 29 dogs with cTCC who underwent surgical treatment were enrolled. Clinical parameters were reviewed using medical records. Tissue expression of epithelial and mesenchymal markers was evaluated by immunohistochemical analysis. The association between the expression of mesenchymal cell markers and clinical parameters, including prognosis, was statistically examined. In five normal bladder tissues used as controls, no expression of mesenchymal markers was observed, except for one tissue that expressed fibronectin. Conversely, epithelial tumour cells expressed vimentin and fibronectin in 23/29 and 19/28 cTCC tissues, respectively. Regarding clinical parameters, vimentin score in Miniature Dachshunds was significantly higher than those in other dog breeds (P < 0.001). Multivariate survival analyses revealed that age>12 years was related to shorter progression-free survival (P = 0.02). Higher vimentin score, lower fibronectin score, and advanced clinical T stage were significantly correlated with shorter median survival time (P < 0.05). The results of this study indicate that vimentin expression was associated with cTCC progression. Further studies are needed to examine the incidence and relevance of EMT in cTCC.

Reliability of ultrasonographic measurements of bovine sole structures in relation to sole horn thickness, measured by computed tomography, and sole horn hardness.

The goal of the present study was to determine the effect of sole horn thickness (SHT) and sole horn hardness (SHD) on ultrasonographic visualization of sole structures in the inner and outer claws of 150 Holstein-Friesian cows, and to evaluate different ultrasound frequencies for this purpose. Ultrasonographic views of the sole structure were considered complete when 3 echogenic lines, representing the ventral surface of the sole horn, the borders of the sole horn and soft-tissue layer, and the ventral surface of the distal phalanx, were seen. The proportion of complete ultrasonographic views of the sole structures, designated as the ultrasonographic visualization proportion (UVP), and the measurement errors of SHT were evaluated by comparing images from computed tomography (CT) and ultrasonography. The latter images were generated using 3 different probes, frequencies of 6.5 and 5.0 MHz, and 2 different ultrasound machines (#1 and #2) to assess the apex, middle, and heel regions of the claws. The UVP were 60.8 to 77.9% for the 6.5-MHz probe in ultrasound machine #1 (probe A), which were lower than those (>90%) for both the 5.0-MHz probe in ultrasound machine #1 (probe B) and the 5.0-MHz probe in ultrasound machine #2 (probe C). The UVP was significantly lower in claws with an SHD ≥50 units than in claws with an SHD <40 or 40 to <50 units (UVP: 77.1% compared with 93.7 and 91.4%, respectively) when measured with probe B. In claws with an SHT <10 mm, the UVP was significantly lower when SHD was ≥50 units compared with <40 or 40 to >50 units; the values were 69.0% versus 91.3 and 85.9%, respectively, for probe A, and 89.7% versus 100 and 100%, respectively, for probe B. When SHT were measured by either probes A or B in ultrasound machine #1, the proportions of claws in which ultrasonographic values were within a ±1 mm range compared with the values obtained by CT were 84.9 to 91.3% for CT-determined SHT <5 mm, 66.7 to 71.9% for CT-determined SHT 5 to <7 mm, 28.9 to 51.2% for CT-determined SHT 7 to <10 mm, and 6.2 to 19.7% for CT-determined SHT ≥10 mm. The data indicated that increased SHT was associated with a decrease in ultrasonographic measurement accuracy. In claws with an SHT <5 mm, the high proportion of ultrasonographic values that were accurate within a ±1 mm range suggests that this imaging modality would be useful in cows with thin soles.

Development of canine X-chromosome inactivation pattern analysis for the detection of cell clonality by incorporating the examination of the SLIT and NTRK-like family member 4 (SLITRK4) gene.

X-chromosome inactivation pattern (XCIP) analysis can be used to assess the clonality of cell populations of various origin by distinguishing the methylated X chromosome from the unmethylated X chromosome. In this study, the utility of XCIP analysis was improved by incorporating the examination of AC dinucleotide repeats in SLIT and NTRK-like family member 4 (SLITRK4) gene into the previously reported CAG repeat examination of androgen receptor (AR) gene in dogs. The rate of heterozygosity when both genes were analysed (125/150, 83.3%) was higher than AR gene examination alone (86/150, 57.3%). Blood samples from heterozygous dogs in either AC-1 or AC-2 of SLITRK4 gene were examined for the corrected inactivation allele ratio (CIAR), resulting in the determination of a reference range of CIAR <3.8 in non-neoplastic cell/tissue samples. Using this analytical method, 49% (21/43) of neoplastic tissue samples from dogs showed a CIAR >3.8, indicating the presence of a clonal population. Through the present study, the availability of canine XCIP analysis was improved by incorporating the examination of the SLITRK4 gene, providing a highly useful laboratory examination system for the detection of the clonality of various cell/tissue samples in dogs.

mTORC2/AKT/HSF1/HuR constitute a feed-forward loop regulating Rictor expression and tumor growth in glioblastoma.

Overexpression of Rictor has been demonstrated to result in increased mechanistic target of rapamycin C2 (mTORC2) nucleation and activity leading to tumor growth and increased invasive characteristics in glioblastoma multiforme (GBM). However, the mechanisms regulating Rictor expression in these tumors is not clearly understood. In this report, we demonstrate that Rictor is regulated at the level of mRNA translation via heat-shock transcription factor 1 (HSF1)-induced HuR activity. HuR is shown to directly bind the 3' untranslated region of the Rictor transcript and enhance translational efficiency. Moreover, we demonstrate that mTORC2/AKT signaling activates HSF1 resulting in a feed-forward cascade in which continued mTORC2 activity is able to drive Rictor expression. RNAi-mediated blockade of AKT, HSF1 or HuR is sufficient to downregulate Rictor and inhibit GBM growth and invasive characteristics in vitro and suppress xenograft growth in mice. Modulation of AKT or HSF1 activity via the ectopic expression of mutant alleles support the ability of AKT to activate HSF1 and demonstrate continued HSF1/HuR/Rictor signaling in the context of AKT knockdown. We further show that constitutive overexpression of HuR is able to maintain Rictor expression under conditions of AKT or HSF1 loss. The expression of these components is also examined in patient GBM samples and correlative associations between the relative expression of these factors support the presence of these signaling relationships in GBM. These data support a role for a feed-forward loop mechanism by which mTORC2 activity stimulates Rictor translational efficiency via an AKT/HSF1/HuR signaling cascade resulting in enhanced mTORC2 activity in these tumors.

Anti-tumour efficacy of etoposide alone and in combination with piroxicam against canine osteosarcoma in a xenograft model.

Osteosarcoma (OSA) in dogs is locally invasive and highly malignant. Distant metastasis is the most common cause of death. To date, the survival rate in dogs with OSA remains poor. The cytotoxic effects of etoposide against canine OSA cell lines, either alone or in combination with piroxicam, have been previously demonstrated in vitro. The aim of this study was to evaluate the anti-tumour effect of etoposide alone and in combination with piroxicam on canine OSA using murine models. Etoposide single agent treatment significantly delayed tumour progression with a marked reduction in Ki-67 immunoreactivity in tumour tissue. Concomitant treatment with piroxicam did not enhance the anti-tumour efficacy of etoposide. Etoposide single agent treatment and combination treatment with piroxicam down-regulated survivin expression, but was not followed by increased apoptotic activity. These findings indicate that etoposide might be a promising novel therapeutic for canine OSA. Further investigations into its potential for clinical application in veterinary oncology are warranted.

Influence of eating quickly and eating until full on anthropometric gains in girls: A population-based, longitudinal study.

BACKGROUND: In examining childhood overweight/obesity, there is a need to consider both eating quickly and eating until full. This longitudinal study investigated the influence of eating quickly and/or eating until full on anthropometric variables and becoming overweight/obese among Japanese schoolgirls. METHODS: Study participants were fourth-grade schoolgirls (aged 9 or 10 years) in Ina Town, Japan. Physical examinations and a questionnaire survey were performed at baseline (fourth grade) and after 3 years (seventh grade). Height, weight, and waist circumference were measured in the physical examinations, while the data on eating quickly and eating until full were collected in the questionnaire survey. Analysis of variance and analysis of covariance were used to compare the differences in each anthropometric variable between fourth and seventh grade among groups. RESULTS: Data on 425 non-overweight/obese schoolgirls in fourth grade were analyzed. Gains in anthropometric variables (body mass index, waist circumference, and waist-to-height ratio) from fourth to seventh grade were significantly larger in the "eating quickly and eating until full" group than in the "not eating quickly and not eating until full" group. In contrast, there were no significant differences in the gains between the "eating quickly or eating until full" group and the "not eating quickly and not eating until full" group. The proportion of overweight/obese girls in seventh grade was higher in the "eating quickly and eating until full" group than in the other groups. CONCLUSIONS: Eating quickly and eating until full had a substantial impact on excess gains in anthropometric variables among schoolgirls, suggesting that modifying these eating behaviors may help prevent non-overweight/obese girls from the excess gains. Accordingly, school health programs need to focus on not eating quickly and/or not eating until full to prevent overweight/obesity; it is necessary to emphasize "the risk of overweight/obesity associated with these eating behaviors" in schools.

Molecular investigation of the direct anti-tumour effects of nonsteroidal anti-inflammatory drugs in a panel of canine cancer cell lines.

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been suggested as effective adjunctive anti-tumour agents in human and veterinary medicine. However, the molecular mechanisms associated with their anti-tumour effects and correlations with the expression of cyclooxygenase (COX) and related molecules in tumours remain controversial. The objective of this study was to compare the expression profiles of COX and related molecules with NSAID sensitivity and to explore the molecular mechanisms of anti-tumour effects. The expression profiles of COXs, prostaglandins (PGs), PGD2 synthases, and PGE2 synthases were obtained, and their correlations with in vitro sensitivity to the NSAIDs piroxicam, carprofen, and robenacoxib were examined, using 26 canine cancer cell lines. Subsequently, microarray analysis was performed using one melanoma cell line to gain insight into mechanisms by which NSAIDs could exert cytotoxic effects. No strong correlation was observed between the cellular expression of COX and related molecules and sensitivity to NSAID treatment. Additionally, NSAIDs inhibited cell growth only at considerably higher concentrations than those required for functional COX inhibition. Microarray data demonstrated that five genes (SLC16A6, PER2, SLC9A8, HTR2B, and BRAF) were significantly upregulated and that four genes (LOC488305, H2AFJ, LOC476445, and ANKRD43) were significantly downregulated by NSAID exposure to the melanoma cell line. These results suggest that the direct in vitro anti-tumour effects of NSAIDs might be mediated by COX/PG-independent pathways. Novel candidate genes that could potentially be involved in the anti-tumour effects of NSAIDs were identified. Further validation and elucidation of their associated mechanisms will contribute to patient selection in clinical settings and the development of effective combination therapies.

Propofol-fentanyl interaction in Beagles - Apnea, response to mechanical ventilation, endotracheal tube, and tetanic stimulation.

The objective of this study was to characterize the propofol-fentanyl interaction in Beagles for four pharmacodynamic endpoints: apnea, response to mechanical ventilation, endotracheal tube, and tetanic stimulation. After anesthesia was induced with varying combinations of propofol and fentanyl, the pharmacodynamic endpoints were assessed in intubated dogs (n=6) using the cross-over design. Effective concentrations of propofol plasma concentration (Cp) and fentanyl Cp were assessed using additive, reduced Greco, Minto, and hierarchical interaction models. The interaction was best described as synergistic by the hierarchical model. A 1ng/mL fentanyl Cp reduced the effective propofol Cp to half or less of that without fentanyl for all endpoints. An additional increment of fentanyl Cp to 5ng/mL or higher hardly reduced effective propofol Cp for all endpoints except response to tetanic stimulation. Additionally, the effective propofol Cp in 50% dogs for response to tetanic stimulation (15% increase of heart rate) was lower than that for the other endpoints at fentanyl Cp >7ng/mL. Peripheral oxygen saturation decreased below 90% after extubation in five treatments in which fentanyl Cps were ≥5ng/mL. Propofol and fentanyl interacted synergistically. To avoid patient-ventilator dyssynchrony and hypoxemia after extubation, fentanyl Cp at 1-5ng/mL may be appropriate in intubated dogs. When a dog responds to mechanical ventilation or endotracheal tube at a high fentanyl Cp >5ng/mL under propofol anesthesia even if the dog tolerate to tetanic stimulation, it may be necessary to increase propofol Cp to eliminate the responses because an additional fentanyl may be little impact.

Identification of molecular markers for oocyte competence in bovine cumulus cells.

Cumulus cells (CCs) have an important role during oocyte growth, competence acquisition, maturation, ovulation and fertilization. In an attempt to isolate potential biomarkers for bovine in vitro fertilization, we identified genes differentially expressed in bovine CCs from oocytes with different competence statuses, through microarray analysis. The model of follicle size, in which competent cumulus-oocyte complexes (COCs) were recovered from bigger follicles (≥8.0 mm in diameter) and less competent ones from smaller follicles (1-3 mm), was used. We identified 4178 genes that were differentially expressed (P < 0.05) in the two categories of CCs. The list was further enriched, through the use of a 2.5-fold change in gene expression as a cutoff value, to include 143 up-regulated and 80 down-regulated genes in CCs of competent COCs compared to incompetent COCs. These genes were screened according to their cellular roles, most of which were related to cell cycle, DNA repair, energy metabolism, metabolism of amino acids, cell signaling, meiosis, ovulation and inflammation. Three candidate genes up-regulated (FGF11, IGFBP4, SPRY1) and three down-regulated (ARHGAP22, COL18A1 and GPC4) in CCs from COCs of big follicles (≥8.1 mm) were selected for qPCR analysis. The selected genes showed the same expression patterns by qPCR and microarray analysis. These genes may be potential genetic markers that predict oocyte competence in in vitro fertilization routines.

Effects of etoposide alone and in combination with piroxicam on canine osteosarcoma cell lines.

Osteosarcoma (OSA) is the most common primary bone tumour in dogs. The poor survival rate in dogs with OSA highlights the need for new therapeutic approaches. This study evaluated the cytotoxic effects of etoposide, alone and in combination with piroxicam, on canine OSA cell cultures. Etoposide alone significantly suppressed cell growth and viability, whereas etoposide in combination with piroxicam exhibited concentration dependent cytotoxicity. The anti-proliferative effect was a result of inactivity of the Cdc2-cyclin B1 complex, which correlated with an increase in the G2/M fraction. This subsequently activated the apoptosis cascade, as indicated by elevated apoptosis levels and up-regulation of poly (ADP-ribose) polymerase proteolytic cleavage. Down-regulation of survivin expression induced by the combination treatment may have contributed to the enhanced cytotoxicity. The results of this study suggest that further investigation of etoposide and piroxicam as a therapeutic combination for canine OSA is warranted.

Local recurrence risk after previous salvage mastectomy.

INTRODUCTION: Breast-conserving surgery is a standard treatment for early breast cancer. For ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery, salvage mastectomy is the current standard surgical procedure. However, it is not rare for patients with IBTR who have received salvage mastectomy to develop local recurrence. In this study, we examined the risk factors of local recurrence after salvage mastectomy for IBTR. PATIENTS AND METHODS: A total of 118 consecutive patients who had histologically confirmed IBTR without distant metastases and underwent salvage mastectomy without irradiation for IBTR between 1989 and 2008 were included from eight institutions in Japan. The risk factors of local recurrence were assessed. RESULTS: The median follow-up period from salvage mastectomy for IBTR was 4.6 years. Patients with pN2 or higher on diagnosis of the primary tumor showed significantly poorer local recurrence-free survival than those with pN0 or pN1 at primary tumor (p < 0.001). Multivariate analysis showed that the lymph node status of the primary tumor was a significantly independent predictive factor of local recurrence-free survival (p = 0.02). CONCLUSION: The lymph node status of the primary tumor might be a predictive factor of local recurrence-free survival after salvage mastectomy for IBTR. Further research and validation studies are needed. (UMIN-CTR number UMIN000008136).

Prognosis after mastectomy versus repeat lumpectomy in patients with ipsilateral breast cancer recurrence: A propensity score analysis.

INTRODUCTION: Mastectomy is the current standard surgical procedure for ipsilateral breast tumor recurrence (IBTR). However, there is little evidence about the prognostic impact of the surgical procedure (mastectomy versus repeat lumpectomy) for IBTR. PATIENTS AND METHODS: A total of 271 consecutive patients who had histologically confirmed IBTR without distant metastases and underwent definitive surgery for IBTR between 1989 and 2008 were included from eight institutions in Japan. The impact of the surgical procedure for IBTR on distant disease-free survival (DDFS) and overall survival (OS) was evaluated using and multivariable proportional hazards regression and propensity score matching methods. RESULTS: Of the 271 patients, 149 patients (55%) underwent repeat lumpectomy and 122 patients (45%) underwent mastectomy after IBTR. The median follow-up period from definitive surgery for IBTR was 55 months. There was no difference in terms of DDFS and OS between repeat lumpectomy and mastectomy after IBTR, adjusted for various clinical and tumor characteristics. In addition, for the matched patient cohort, no difference in DDFS and OS was seen between the 2 groups. CONCLUSION: In our study, both multivariate analysis and the propensity score matching method demonstrated that there was no difference in terms of DDFS and OS between repeat lumpectomy and mastectomy after IBTR. Further studies are warranted (UMIN-CTR number UMIN000008136).

Thymic Carcinoma with Cartilage Formation in a Dog.

An 11-year-old female Chihuahua exhibited respiratory distress and a computed tomography scan showed a large mass in the anterior thoracic cavity. During surgery, it was found that the mass was strongly adherent to surrounding tissue. A histopathological examination of a biopsy sample from the mass revealed proliferation of atypical epithelial cells and cartilage formation admixed with mature lymphocytes. Immunohistochemically, the tumour cells, as well as the normal canine thymic epithelial cells, were positive for pan-cytokeratin (CK), CK5/6, CK19, p63 and bone morphogenetic protein (BMP) 6. Foci of cartilage tissue were formed in association with the neoplastic epithelial tissue. In the normal canine thymus, the subcapsular epithelial cells are positive for both CK19 and BMP6. These findings indicate that the cartilage element within the tumour developed from CK19-positive neoplastic epithelial cells, which were derived from the thymic subcapsular epithelium. This case represents a novel variant of canine thymic epithelial tumour that exhibits cartilage differentiation.

Sodium-glucose cotransporter 2 inhibitor luseogliflozin improves glycaemic control, assessed by continuous glucose monitoring, even on a low-carbohydrate diet.

This randomized, double-blind, placebo-controlled, crossover study was the first to determine the effects of luseogliflozin in combination with a low-carbohydrate diet (LCD) on 24-h glucose variability, assessed by continuous glucose monitoring (CGM). A total of 18 Japanese patients with type 2 diabetes were randomized into two groups, in which patients first received luseogliflozin 2.5 mg once daily then placebo for 8 days each, or vice versa. Patients took luseogliflozin or placebo with a normal-carbohydrate diet (NCD) on day 7 and with the LCD on day 8. CGM was performed on both days. Luseogliflozin significantly reduced glucose exposure in terms of the area under the curve over the course of 24 h when administered with the NCD (difference vs placebo: -555.6 mg/dl·h [1 mg/dl = 0.0556 mmol/l]; p < 0.001) or with the LCD (-660.7 mg/dl·h; p < 0.001). No hypoglycaemia was observed over 24 h with either diet. Although glucose levels were lower with the LCD than with the NCD in the placebo treatment period, luseogliflozin with the LCD improved glycaemic control throughout the day to nearly the same extent as luseogliflozin with the NCD, without inducing hypoglycaemia.

Anti-tumour effect of metformin in canine mammary gland tumour cells.

Metformin is an oral hypoglycaemic drug used in type 2 diabetes. Its pharmacological activity reportedly involves mitochondrial respiratory complex I, and mitochondrial respiratory complex inhibitors have a strong inhibitory effect on the growth of metastatic canine mammary gland tumour (CMGT) cell lines. It is hypothesised that metformin has selective anti-tumour effects on metastatic CMGT cells. The aim of this study was to investigate the in vitro effect of metformin on cell growth, production of ATP and reactive oxygen species (ROS), and the AMP-activated protein kinase (AMPK) mammalian target of rapamycin (mTOR) pathway in two CMGT clonal cell lines with different metastatic potential. In addition, transcriptome analysis was used to determine cellular processes disrupted by metformin and in vivo anti-tumour effects were examined in a mouse xenograft model. Metformin inhibited CMGT cell growth in vitro, with the metastatic clone (CHMp-5b) displaying greater sensitivity. ATP depletion and ROS elevation were observed to a similar extent in the metastatic and non-metastatic (CHMp-13a) cell lines after metformin exposure. However, subsequent AMPK activation and mTOR pathway inhibition were prominent only in metformin-insensitive non-metastatic cells. Microarray analysis revealed inhibition of cell cycle progression by metformin treatment in CHMp-5b cells, which was further confirmed by Western blotting and cell cycle analysis. Additionally, metformin significantly suppressed tumour growth in xenografted metastatic CMGT cells. In conclusion, metformin exhibited an anti-tumour effect in metastatic CMGT cells through AMPK-independent cell cycle arrest. Its mechanism of action differed in the non-metastatic clone, where AMPK activation and mTOR inhibition were observed.

Effects of luseogliflozin, a sodium-glucose co-transporter 2 inhibitor, on 24-h glucose variability assessed by continuous glucose monitoring in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled, crossover study.

The aim of the present study was to determine the effects of luseogliflozin on 24-h glucose levels, assessed by continuous glucose monitoring, and on pharmacodynamic variables measured throughout the day. In this double-blind, placebo-controlled, crossover study, 37 patients with type 2 diabetes mellitus inadequately controlled with diet and exercise were randomized into two groups. Patients in each group first received luseogliflozin then placebo for 7 days each, or vice versa. After 7 days of treatment, the mean 24-h glucose level was significantly lower with luseogliflozin than with placebo [mean (95% confidence interval) 145.9 (134.4-157.5) mg/dl vs 168.5 (156.9-180.0) mg/dl; p < 0.001]. The proportion of time spent with glucose levels ≥70 to ≤180 mg/dl was significantly greater with luseogliflozin than with placebo [median (interquartile range) 83.2 (67.7-96.5)% vs 71.9 (46.9-83.3)%; p < 0.001] without inducing hypoglycaemia. The decrease in glucose levels was accompanied by reductions in serum insulin levels throughout the day.

Phenotypic screening of a library of compounds against metastatic and non-metastatic clones of a canine mammary gland tumour cell line.

Metastases are associated with a poor prognosis for canine mammary gland tumours (CMGTs). Metastatic and non-metastatic clones were isolated previously from a single malignant CMGT cell line. The difference in metastatic potential between the two cell lines was hypothesised to be associated with distinct cellular signalling. The aim of this study was to screen for compounds that specifically target metastatic cells in order to improve CMGT therapeutic outcomes. The two clonal cell lines were characterised by transcriptome analysis and their sensitivity to a library of 291 different compounds was compared. The metastatic clone exhibited elevated expression of molecules associated with degradation of the extracellular matrix, epithelial-mesenchymal transition and cancer stem cell phenotype. This was confirmed using a matrigel invasion assay and by assessment of aldehyde dehydrogenase activity. The mitochondrial respiratory chain complex inhibitors (MRCIs; rotenone, antimycin and oligomycin) significantly inhibited the growth of the metastatic clone. Although MRCIs similarly depleted mitochondrial ATP in both clones, the subsequent cellular response was different, with toxicity to the metastatic clone being independent of AMP-activated protein kinase activity. The results of this study suggest a potential utility of MRCIs as anti-tumour agents against metastatic CMGTs. Further studies are needed to investigate the clinical utility of MRCIs and to determine the association between MRCI sensitivity and malignancy.