Quantitative Expression and Co-Localization of Wnt Signalling Related Proteins in Feline Squamous Cell Carcinoma

Altered E-cadherin/β-catenin expression in feline cutaneous squamous cell carcinomas

Cutaneous squamous cell carcinoma (CSCC) is the most common malignant skin tumour in cats and the nature of the molecular mechanisms involved is poorly defined. Included among the molecular mechanisms in human and canine CSCCs is altered expression of E-cadherin/β-catenin. This study aimed to explore the immunohistochemical expression pattern of E-cadherin and β-catenin in 43 samples of feline CSCC by using a tissue microarray to elucidate whether expression of these molecules is dysregulated. Membrane expression of E-cadherin and membrane and cytoplasmic expression of β-catenin were significantly reduced in the CSCCs. Cytoplasmic expression of E-cadherin and nuclear expression of β-catenin were also found in some CSCCs. These findings indicate that altered expression of E-cadherin and β-catenin is a frequent event in feline CSCCs, suggesting that these molecules play an important role in acquisition of the malignant phenotype in feline patients with CSCC. The results also suggest the existence of a subpopulation of feline patients with CSCC in which the Wnt pathway may contribute to epidermal carcinogenesis.

Repurposing Drugs in Small Animal Oncology

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries. The interest in repurposed anti-cancer drugs has led to numerous in vivo and in vitro studies, with some promising results. Some randomized clinical trials have also been performed in humans, with certain drugs showing some degree of clinical efficacy, but the true clinical benefit for most of these drugs remains unknown. Repurposing drugs in veterinary oncology is a very new concept and only a few studies have been published so far. In this review, we summarize both the benefits and challenges of using repurposed anti-cancer drugs; we report and discuss the most relevant studies that have been previously published in small animal oncology, and we suggest potential drugs that could be clinically investigated for anti-cancer treatment in dogs and cats.

Companion Animal Model in Translational Oncology; Feline Oral Squamous Cell Carcinoma and Canine Oral Melanoma

Simple Summary

Laboratory rodents are the most common animal models used in preclinical cancer research. Companion animals with naturally occurring cancers are an under-utilized natural model for the development of new anti-cancer drugs. Dogs and cats develop several types of cancers that resemble those arising in humans with similar clinical and histopathological features and often with similar molecular and genetic backgrounds. Exposure to environmental carcinogens, including air, food and water are also common between people and their pets. Dogs and cats are a unique model that could be integrated between the preclinical laboratory animal model and human clinical trials.

Abstract

Companion animals with naturally occurring cancers can provide an advantageous model for cancer research and in particular anticancer drug development. Compared to commonly utilized mouse models, companion animals, specifically dogs and cats, share a closer phylogenetical distance, body size, and genome organization. Most importantly, pets develop spontaneous, rather than artificially induced, cancers. The incidence of cancer in people and companion animals is quite similar and cancer is the leading cause of death in dogs over 10 years of age. Many cancer types in dogs and cats have similar pathological, molecular, and clinical features to their human counterparts. Drug toxicity and response to anti-cancer treatment in dogs and cats are also similar to those in people. Companion animals share their lives with their owners, including the environmental and socioeconomic cancer-risk factors. In contrast to humans, pets have a shorter life span and cancer progression is often more rapid. Clinical trials in companion animals are cheaper and less time consuming compared to human trials. Dogs and cats with naturally occurring cancers are an ideal and unique model for human cancer research. Model selection for the specific type of cancer is of pivotal importance. Although companion animal models for translational research have been reviewed previously, this review will try to summarize the most important advantages and disadvantages of this model. Feline oral squamous cell carcinoma as a model for head and neck squamous cell carcinoma and canine oral melanoma as a model for mucosal melanoma and immunotherapy in people will be discussed as examples.

QuArray: an application for tissue array whole slide image export and signal analysis

MOTIVATION

Tissue array (TA) staining, combined with whole slide imaging (WSI) methods facilitate discovery of biomarkers for diagnosis, prognostication and disease stratification. A key impediment in TA WSI analysis is handling missing tissue and artefacts when identifying tissue cores before quantitative, standardized downstream analysis. There is a need for an open access, user friendly, integrated analysis of the WSI generated using TAs in clinical and scientific research laboratories.

RESULTS

We have developed QuArray (Quantitative Array Application) for image export and signal analysis of TAs using WSI. The application input is a WSI and a corresponding TA configuration file. QuArray identifies and exports core images and analyses chromogen staining in a simple graphical user interface. Output data is saved to file for further analysis including indexed data.

AVAILABILITYAND IMPLEMENTATION

Available for download from https://github.com/c-arthurs/QuArray under an MIT licence.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Reproductive history determines Erbb2 locus amplification, WNT signalling and tumour phenotype in a murine breast cancer model

Understanding the mechanisms underlying tumour heterogeneity is key to the development of treatments that can target specific tumour subtypes. We have previously targeted CRE recombinase-dependent conditional deletion of the tumour suppressor genes Brca1, Brca2, p53 (also known as Trp53) and/or Pten to basal or luminal oestrogen receptor-negative (ER⁻) cells of the mouse mammary epithelium. We demonstrated that both the cell-of-origin and the tumour-initiating genetic lesions cooperate to influence mammary tumour phenotype. Here, we use a CRE-activated HER2 orthologue to specifically target HER2/ERBB2 oncogenic activity to basal or luminal ER⁻ mammary epithelial cells and perform a detailed analysis of the tumours that develop. We find that, in contrast to our previous studies, basal epithelial cells are less sensitive to transformation by the activated NeuKI allele, with mammary epithelial tumour formation largely confined to luminal ER⁻ cells. Histologically, most tumours that developed were classified as either adenocarcinomas of no special type or as metaplastic adenosquamous tumours. The former were typically characterized by amplification of the NeuNT/Erbb2 locus; in contrast, tumours displaying squamous metaplasia were enriched in animals that had been through at least one pregnancy and typically had lower levels of NeuNT/Erbb2 locus amplification but had activated canonical WNT signalling. Squamous changes in these tumours were associated with activation of the epidermal differentiation cluster. Thus, in this model of HER2 breast cancer, cell-of-origin, reproductive history, NeuNT/Erbb2 locus amplification and the activation of specific branches of the WNT signalling pathway all interact to drive inter-tumour heterogeneity.

Summary: Using a mouse model of breast cancer, the authors show mammary epithelial cell-type sensitivity to transformation by HER2, as well as a change in tumour phenotype associated with reproductive history and driven by WNT signalling.

The Small Molecule BIBR1532 Exerts Potential Anti-cancer Activities in Preclinical Models of Feline Oral Squamous Cell Carcinoma Through Inhibition of Telomerase Activity and Down-Regulation of TERT

Expression of telomerase reverse transcriptase (TERT) and telomerase activity (TA) is a main feature of cancer, contributing to cell immortalization by causing telomeres dysfunction. BIBR1532 is a potent telomerase inhibitor that showed potential anti-tumor activities in several types of cancer, by triggering replicative senescence and apoptosis. In a previous work, we detected, for the first time, TERT expression and TA in preclinical models of feline oral squamous cell carcinoma (FOSCC); therefore, we aimed at extending our investigation by testing the effects of treatment with BIBR1532, in order to explore the role of telomerase in this tumor and foreshadow the possibility of it being considered as a future therapeutic target. In the present study, treatment of FOSCC cell lines SCCF1, SCCF2, and SCCF3 with BIBR1532 resulted in successful inhibition of TA, with subsequent cell growth stoppage and decrease in cell viability. Molecular data showed that up-regulation of cell cycle inhibitor p21, unbalancing of Bax/Bcl-2 ratio, and down-regulation of survival gene Survivin were mostly involved in the observed cellular events. Moreover, BIBR1532 diminished the expression of TERT and its transcriptional activator cMyc, resulting in the down-regulation of epidermal growth factor receptor (EGFR), phospho-ERK/ERK ratio, and matrix metalloproteinases (MMPs)-1/-2 and−9, likely as a consequence of an impairment of TERT extra-telomeric functions. Taken together, our data suggest that BIBR1532 exerts multiple anti-cancer activities in FOSCC by inhibiting telomerase pathway and interfering with signaling routes involved in cell proliferation, cell survival, and invasion, paving the way for future translational studies aimed at evaluating its possible employment in the treatment of this severe tumor of cats.

Equine penile squamous cell carcinoma: expression of biomarker proteins and EcPV2

Equine penile squamous cell carcinoma (EpSCC) is a relatively common cutaneous neoplasm with a poor prognosis. In this study, we aimed to determine the protein expression and colocalisation of FRA1, c-Myc, Cyclin D1, and MMP7 in normal (NT), tumour (T), hyperplastic epidermis and/or squamous papilloma (Hyp/Pap), poorly-differentiated (PDSCC), or well-differentiated (WDSCC) EpSCC using a tissue array approach. Further objectives were to correlate protein expression to (i) levels of inflammation, using a convolutional neural network (ii) equine papillomavirus 2 (EcPV2) infection, detected using PCR amplification. We found an increase in expression of FRA1 in EpSCC compared to NT samples. c-Myc expression was higher in Hyp/Pap and WDSCC but not PDSCC whereas MMP7 was reduced in WDSCC compared with NT. There was a significant increase in the global intersection coefficient (GIC) of FRA1 with MMP7, c-Myc, and Cyclin D1 in EpSCC. Conversely, GIC for MMP7 with c-Myc was reduced in EpSCC tissue. Inflammation was positively associated with EcPV2 infection in both NT and EpSCC but not Hyp/Pap. Changes in protein expression could be correlated with EcPV2 for Cyclin D1 and c-Myc. Our results evaluate novel biomarkers of EpSCC and a putative correlation between the expression of biomarkers, EcPV2 infection and inflammation.

Telomerase Reverse Transcriptase (TERT) Expression, Telomerase Activity, and Expression of Matrix Metalloproteinases (MMP)-1/-2/-9 in Feline Oral Squamous Cell Carcinoma Cell Lines Associated With Felis catus Papillomavirus Type-2 Infection

Telomerase activity contributes to cell immortalization by avoiding telomere shortening at each cell division; indeed, its catalytic subunit telomerase reverse transcriptase (TERT) is overexpressed in many tumors, including human oral squamous cell carcinoma (hOSCC). In these tumors, matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases involved in cell migration, contribute to invasive potential of cancer cells. A proportion of hOSCC is associated with infection by high-risk human papillomavirus (HR-HPVs), whose E6 oncogene enhances TERT and MMPs expression, thus promoting cancer progression. Feline oral squamous cell carcinoma (FOSCC) is a malignant tumor with highly invasive phenotype; however, studies on telomerase activity, TERT, and MMPs expression are scarce. In this study, we demonstrate telomerase activity, expression of TERT, and its transcriptional activator cMyc along with expression of MMP-1, -2, and -9 in FOSCC-derived cell lines SCCF2 and SCCF3, suggesting a contribution by these pathways in cell immortalization and invasion in these tumors. Recent studies suggest that a sub-group of FOSCC as well as SCCF2 and SCCF3 are associated with Felis catus PV type-2 (FcaPV-2) infection. However, in this work, FcaPV-2 E6 gene knock-down caused no shift in either TERT, cMyc, or MMPs levels, suggesting that, unlike its human counterpart, the viral oncogene plays no role in their regulation.

Expression of ribosomal proteins in normal and cancerous human prostate tissue

Few quantifiable tissue biomarkers for the diagnosis and prognosis of prostate cancer exist. Using an unbiased, quantitative approach, this study evaluates the potential of three proteins of the 40S ribosomal protein complex as putative biomarkers of malignancy in prostate cancer. Prostate tissue arrays, constructed from 82 patient samples (245 tissue cores, stage pT3a or pT3b), were stained for antibodies against three ribosomal proteins, RPS19, RPS21 and RPS24. Semi-automated Ox-DAB signal quantification using ImageJ software revealed a significant change in expression of RPS19, RPS21 and RPS24 in malignant vs non-malignant tissue (p<0.0001). Receiver operating characteristics curves were calculated to evaluate the potential of each protein as a biomarker of malignancy in prostate cancer. Positive likelihood ratios for RPS19, RPS21 and RPS24 were calculated as 2.99, 4.21, and 2.56 respectively, indicating that the overexpression of the protein is correlated with the presence of disease. Triple-labelled, quantitative, immunofluorescence (with RPS19, RPS21 and RPS24) showed significant changes (p<0.01) in the global intersection coefficient, a measure of how often two fluorophore signals intersect, for RPS19 and RPS24 only. No change was observed in the co-localization of any other permutations of the three proteins. Our results show that RPS19, RPS21 or RPS24 are upregulated in malignant tissue and may serve as putative biomarkers for prostate cancer.

Correction: Quantitative Expression and Co-Localization of Wnt Signalling Related Proteins in Feline Squamous Cell Carcinoma

[This corrects the article DOI: 10.1371/journal.pone.0161103.].