Celebrating Discoveries in Wnt Signaling: How One Man Gave Wings to an Entire Field.

This year's Gairdner Foundation Award for Biomedical Research goes to Roel Nusse for his pioneering work on the Wnt signaling pathway and its many roles in development, cancer, and stem cells.

Control of Glucocorticoid Receptor Levels by PTEN Establishes a Failsafe Mechanism for Tumor Suppression.

The PTEN tumor suppressor controls cell death and survival by regulating functions of various molecular targets. While the role of PTEN lipid-phosphatase activity on PtdIns(3,4,5)P3 and inhibition of PI3K pathway is well characterized, the biological relevance of PTEN protein-phosphatase activity remains undefined. Here, using knockin (KI) mice harboring cancer-associated and functionally relevant missense mutations, we show that although loss of PTEN lipid-phosphatase function cooperates with oncogenic PI3K to promote rapid mammary tumorigenesis, the additional loss of PTEN protein-phosphatase activity triggered an extensive cell death response evident in early and advanced mammary tumors. Omics and drug-targeting studies revealed that PI3Ks act to reduce glucocorticoid receptor (GR) levels, which are rescued by loss of PTEN protein-phosphatase activity to restrain cell survival. Thus, we find that the dual regulation of GR by PI3K and PTEN functions as a rheostat that can be exploited for the treatment of PTEN loss-driven cancers.

miR-182 targeting reprograms tumor-associated macrophages and limits breast cancer progression.

The protumor roles of alternatively activated (M2) tumor-associated macrophages (TAMs) have been well established, and macrophage reprogramming is an important therapeutic goal. However, the mechanisms of TAM polarization remain incompletely understood, and effective strategies for macrophage targeting are lacking. Here, we show that miR-182 in macrophages mediates tumor-induced M2 polarization and can be targeted for therapeutic macrophage reprogramming. Constitutive miR-182 knockout in host mice and conditional knockout in macrophages impair M2-like TAMs and breast tumor development. Targeted depletion of macrophages in mice blocks the effect of miR-182 deficiency in tumor progression while reconstitution of miR-182-expressing macrophages promotes tumor growth. Mechanistically, cancer cells induce miR-182 expression in macrophages by TGFß signaling, and miR-182 directly suppresses TLR4, leading to NFκb inactivation and M2 polarization of TAMs. Importantly, therapeutic delivery of antagomiR-182 with cationized mannan-modified extracellular vesicles effectively targets macrophages, leading to miR-182 inhibition, macrophage reprogramming, and tumor suppression in multiple breast cancer models of mice. Overall, our findings reveal a crucial TGFß/miR-182/TLR4 axis for TAM polarization and provide rationale for RNA-based therapeutics of TAM targeting in cancer.

ADAMTS18 deficiency associates extracellular matrix dysfunction with a higher risk of HER2-positive mammary tumorigenesis and metastasis.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2)-positive breast cancer accounts for about 20% of all breast cancer cases and is correlated with a high relapse rate and poor prognosis. ADAMTS18 is proposed as an important functional tumor suppressor gene involved in multiple malignancies, including breast cancer. It functions as an extracellular matrix (ECM) modifier. However, it remains unclear whether ADAMTS18 affects mammary tumorigenesis and malignant progression through its essential ECM regulatory function. METHODS: To elucidate the role of ADAMTS18 in HER2-positive mammary tumorigenesis and metastasis in vivo, we compared the incidence of mammary tumor and metastasis between Adamts18-knockout (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18-/-) and Adamts18-wildtype (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18+/+). The underlying mechanisms by which ADAMTS18 regulates HER2-positive tumorigenesis and metastasis were investigated by pathology, cell culture, Western blot and immunochemistry. RESULTS: Adamts18 mRNA is mainly expressed in myoepithelial cells of the mammary duct. ADAMTS18 deficiency leads to a significantly increased incidence of mammary tumors and metastasis, as well as mammary hyperplasia in mice, over 30 months of observation. The proliferation, migration and invasion capacities of primary Her2t/w/Adamts18-/- mammary tumor cells are significantly higher than those of primary Her2t/w/Adamts18+/+ mammary tumor cells in vitro. At 30 months of age, the expression levels of laminin (LNα5), fibronectin (FN) and type I collagen (ColI) in the mammary glands of Her2t/w/Adamts18-/- mice are significantly increased, and the activities of integrin-mediated PI3K/AKT, ERK and JNK signaling pathways are enhanced. CONCLUSIONS: ADAMTS18 deficiency leads to alterations in mammary ECM components (e.g., LNα5, FN, ColI), which are associated with a higher risk of HER2-positive mammary tumorigenesis and metastasis.

YRNA and tRNA fragments can differentiate benign from malignant canine mammary gland tumors.

Mammary gland tumors (MGT) are the most common tumors in sexually intact female dogs. The functional regulation of miRNAs, a type of noncoding RNAs (ncRNAs), in canine MGT has been extensively investigated. However, the expression of other ncRNAs, such as YRNAs and transfer RNA-derived fragments (tRFs) in canine MGT is unknown. We investigated ncRNAs other than miRNAs from our small RNA project (PRJNA716131) in different canine MGT histologic subtypes. This study included benign tumors (benign mixed tumor, complex adenoma) and malignant tumors (carcinoma in benign tumor and carcinoma with metastasis) samples. Aberrantly expressed ncRNAs were examined by comparisons among MGT subtypes. The relative expression trends were validated in canine MGT tissues, plasma, extracellular vesicles, and MGT cell lines using quantitative reverse transcription PCR. Three aberrantly expressed ncRNAs were identified by comparisons among MGT subtypes. YRNA and tRNA-Gly-GCC distinguished benign mixed tumor from other MGT histologic subtypes, while tRNA-Val differentiated complex adenoma, carcinoma in benign tumors, and carcinoma with metastasis. The ROC curve of the three ncRNAs showed they might be potential biomarkers to discriminate malignant from benign MGT. YRNA and tRFs expression levels were decreased in metastatic compared with primary canine MGT cell lines. To the best of our knowledge, this is the first investigation of YRNA and tRFs in canine MGT. The three identified ncRNAs may be biomarkers for differentiating MGT histologic subtypes. Suggested Reviewers: Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporatio.

The tumor suppressor p53 regulates polarity of self-renewing divisions in mammary stem cells.

Stem-like cells may be integral to the development and maintenance of human cancers. Direct proof is still lacking, mainly because of our poor understanding of the biological differences between normal and cancer stem cells (SCs). Using the ErbB2 transgenic model of breast cancer, we found that self-renewing divisions of cancer SCs are more frequent than their normal counterparts, unlimited and symmetric, thus contributing to increasing numbers of SCs in tumoral tissues. SCs with targeted mutation of the tumor suppressor p53 possess the same self-renewal properties as cancer SCs, and their number increases progressively in the p53 null premalignant mammary gland. Pharmacological reactivation of p53 correlates with restoration of asymmetric divisions in cancer SCs and tumor growth reduction, without significant effects on additional cancer cells. These data demonstrate that p53 regulates polarity of cell division in mammary SCs and suggest that loss of p53 favors symmetric divisions of cancer SCs, contributing to tumor growth.

Analysis of serum peptidome profiles of non-metastatic and metastatic feline mammary carcinoma using liquid chromatography-tandem mass spectrometry.

BACKGROUND: Feline mammary carcinoma (FMC) is a common aggressive and highly metastatic cancer affecting female cats. Early detection is essential for preventing local and distant metastasis, thereby improving overall survival rates. While acquiring molecular data before surgery offers significant potential benefits, the current protein biomarkers for monitoring disease progression in non-metastatic FMC (NmFMC) and metastatic FMC (mFMC) are limited. The objective of this study was to investigate the serum peptidome profiles of NmFMC and mFMC using liquid chromatography-tandem mass spectrometry. A cross-sectional study was conducted to compare serum peptidome profiles in 13 NmFMC, 23 mFMC and 18 healthy cats. The liquid chromatography-tandem mass spectrometry analysis was performed on non-trypsinized samples. RESULTS: Out of a total of 8284 expressed proteins observed, several proteins were found to be associated with human breast cancer. In NmFMC, distinctive protein expressions encompassed double-stranded RNA-binding protein Staufen homolog 2 (STAU2), associated with cell proliferation, along with bromodomain adjacent to zinc finger domain 2A (BAZ2A) and gamma-aminobutyric acid type A receptor subunit epsilon (GABRE), identified as potential treatment targets. Paradoxically, positive prognostic markers emerged, such as complement C1q like 3 (C1QL3) and erythrocyte membrane protein band 4.1 (EPB41 or 4.1R). Within the mFMC group, overexpressed proteins associated with poor prognosis were exhibited, including B-cell lymphoma 6 transcription repressor (BCL6), thioredoxin reductase 3 (TXNRD3) and ceruloplasmin (CP). Meanwhile, the presence of POU class 5 homeobox (POU5F1 or OCT4) and laminin subunit alpha 1 (LAMA1), reported as metastatic biomarkers, was noted. CONCLUSION: The presence of both pro- and anti-proliferative proteins was observed, potentially indicating a distinctive characteristic of NmFMC. Conversely, proteins associated with poor prognosis and metastasis were noted in the mFMC group.

AGR2-mediated unconventional secretion of 14-3-3ε and α-actinin-4, responsive to ER stress and autophagy, drives chemotaxis in canine mammary tumor cells.

BACKGROUND: Canine mammary tumors (CMTs) in intact female dogs provide a natural model for investigating metastatic human cancers. Our prior research identified elevated expression of Anterior Gradient 2 (AGR2), a protein disulfide isomerase (PDI) primarily found in the endoplasmic reticulum (ER), in CMT tissues, highly associated with CMT progression. We further demonstrated that increased AGR2 expression actively influences the extracellular microenvironment, promoting chemotaxis in CMT cells. Unraveling the underlying mechanisms is crucial for assessing the potential of therapeutically targeting AGR2 as a strategy to inhibit a pro-metastatic microenvironment and impede tumor metastasis. METHODS: To identify the AGR2-modulated secretome, we employed proteomics analysis of the conditioned media (CM) from two CMT cell lines ectopically expressing AGR2, compared with corresponding vector-expressing controls. AGR2-regulated release of 14-3-3ε (gene: YWHAE) and α-actinin 4 (gene: ACTN4) was validated through ectopic expression, knockdown, and knockout of the AGR2 gene in CMT cells. Extracellular vesicles derived from CMT cells were isolated using either differential ultracentrifugation or size exclusion chromatography. The roles of 14-3-3ε and α-actinin 4 in the chemotaxis driven by the AGR2-modulated CM were investigated through gene knockdown, antibody-mediated interference, and recombinant protein supplement. Furthermore, the clinical relevance of the release of 14-3-3ε and α-actinin 4 was assessed using CMT tissue-immersed saline and sera from CMT-afflicted dogs. RESULTS: Proteomics analysis of the AGR2-modulated secretome revealed increased abundance in 14-3-3ε and α-actinin 4. Ectopic expression of AGR2 significantly increased the release of 14-3-3ε and α-actinin 4 in the CM. Conversely, knockdown or knockout of AGR2 expression remarkably reduced their release. Silencing 14-3-3ε or α-actinin 4 expression diminished the chemotaxis driven by AGR2-modulated CM. Furthermore, AGR2 controls the release of 14-3-3ε and α-actinin 4 primarily via non-vesicular routes, responding to the endoplasmic reticulum (ER) stress and autophagy activation. Knockout of AGR2 resulted in increased α-actinin 4 accumulation and impaired 14-3-3ε translocation in autophagosomes. Depletion of extracellular 14-3-3ε or α-actinin 4 reduced the chemotaxis driven by AGR2-modulated CM, whereas supplement with recombinant 14-3-3ε in the CM enhanced the CM-driven chemotaxis. Notably, elevated levels of 14-3-3ε or α-actinin 4 were observed in CMT tissue-immersed saline compared with paired non-tumor samples and in the sera of CMT dogs compared with healthy dogs. CONCLUSION: This study elucidates AGR2's pivotal role in orchestrating unconventional secretion of 14-3-3ε and α-actinin 4 from CMT cells, thereby contributing to paracrine-mediated chemotaxis. The insight into the intricate interplay between AGR2-involved ER stress, autophagy, and unconventional secretion provides a foundation for refining strategies aimed at impeding metastasis in both canine mammary tumors and potentially human cancers.

PD-L1 mRNA and protein expression in canine mammary carcinomas: Correlation with histopathological grade and molecular markers.

Programmed death ligand 1 (PD-L1) is an immune checkpoint molecule that plays a crucial role in regulating antitumor immune responses. Canine mammary carcinomas (CMCs) are common tumors of dogs. Despite extensive studies on the heterogeneity of CMCs, there is still a lack of effective precision therapies for the treatment of CMCs. In this study, we aimed to investigate the correlation between PD-L1 mRNA and protein expression in CMCs and explore its association with histopathological grade and molecular markers, including the estrogen receptor, epidermal growth factor receptor 2, and cytokeratin 5/6 (CK5/6). Formalin-fixed paraffin-embedded samples were evaluated for PD-L1 mRNA expression using RNA in situ hybridization and PD-L1 protein expression using immunohistochemistry. We observed no substantial correlation between PD-L1 mRNA and protein expression in CMCs; however, PD-L1 mRNA levels were significantly higher in grade 3 than in grade 1 tumors (P = .001). In addition, we observed a positive correlation between PD-L1 protein expression and CK5/6 expression in CMCs (P = .032). These findings suggest that PD-L1 expression in CMCs is heterogeneous and may be regulated post-transcriptionally. Further studies are needed to explore the prognostic and therapeutic implications of PD-L1 expression in different molecular subtypes of CMCs and their potential as predictive biomarkers for immunotherapy.

Ki-67 regulates global gene expression and promotes sequential stages of carcinogenesis.

Ki-67 is a nuclear protein that is expressed in all proliferating vertebrate cells. Here, we demonstrate that, although Ki-67 is not required for cell proliferation, its genetic ablation inhibits each step of tumor initiation, growth, and metastasis. Mice lacking Ki-67 are resistant to chemical or genetic induction of intestinal tumorigenesis. In established cancer cells, Ki-67 knockout causes global transcriptome remodeling that alters the epithelial-mesenchymal balance and suppresses stem cell characteristics. When grafted into mice, tumor growth is slowed, and metastasis is abrogated, despite normal cell proliferation rates. Yet, Ki-67 loss also down-regulates major histocompatibility complex class I antigen presentation and, in the 4T1 syngeneic model of mammary carcinoma, leads to an immune-suppressive environment that prevents the early phase of tumor regression. Finally, genes involved in xenobiotic metabolism are down-regulated, and cells are sensitized to various drug classes. Our results suggest that Ki-67 enables transcriptional programs required for cellular adaptation to the environment. This facilitates multiple steps of carcinogenesis and drug resistance, yet may render cancer cells more susceptible to antitumor immune responses.

Parsing ß-catenin's cell adhesion and Wnt signaling functions in malignant mammary tumor progression.

During malignant progression, epithelial cancer cells dissolve their cell-cell adhesion and gain invasive features. By virtue of its dual function, ß-catenin contributes to cadherin-mediated cell-cell adhesion, and it determines the transcriptional output of Wnt signaling: via its N terminus, it recruits the signaling coactivators Bcl9 and Pygopus, and via the C terminus, it interacts with the general transcriptional machinery. This duality confounds the simple loss-of-function analysis of Wnt signaling in cancer progression. In many cancer types including breast cancer, the functional contribution of ß-catenin's transcriptional activities, as compared to its adhesion functions, to tumor progression has remained elusive. Employing the mouse mammary tumor virus (MMTV)-PyMT mouse model of metastatic breast cancer, we compared the complete elimination of ß-catenin with the specific ablation of its signaling outputs in mammary tumor cells. Notably, the complete lack of ß-catenin resulted in massive apoptosis of mammary tumor cells. In contrast, the loss of ß-catenin's transcriptional activity resulted in a reduction of primary tumor growth, tumor invasion, and metastasis formation in vivo. These phenotypic changes were reflected by stalled cell cycle progression and diminished epithelial-mesenchymal transition (EMT) and cell migration of breast cancer cells in vitro. Transcriptome analysis revealed subsets of genes which were specifically regulated by ß-catenin's transcriptional activities upon stimulation with Wnt3a or during TGF-ß-induced EMT. Our results uncouple the signaling from the adhesion function of ß-catenin and underline the importance of Wnt/ß-catenin-dependent transcription in malignant tumor progression of breast cancer.

Establishment and characterization of canine mammary tumoroids for translational research.

BACKGROUND: Cancer heterogeneity is a main obstacle for the development of effective therapies, as its replication in in vitro preclinical models is challenging. Around 96% of developed drugs are estimated to fail from discovery to the clinical trial phase probably because of the unsuitability and unreliability of current preclinical models (Front Pharmacol 9:6, 2018; Nat Rev Cancer 8: 147-56, 2008) in replicating the overall biology of tumors, for instance the tumor microenvironment. Breast cancer is the most frequent cancer among women causing the greatest number of cancer-related deaths. Breast cancer can typically be modeled in vitro through the use of tumoroids; however, current approaches using mouse tumoroids fail to reproduce crucial aspect of human breast cancer, while access to human cells is limited and the focus of ethical concerns. New models of breast cancer, such as companion dogs, have emerged given the resemblance of developed spontaneous mammary tumors to human breast cancer in many clinical and molecular aspects; however, they have so far failed to replicate the tumor microenvironment. The present work aimed at developing a robust canine mammary tumor model in the form of tumoroids which recapitulate the tumor diversity and heterogeneity. RESULTS: We conducted a complete characterization of canine mammary tumoroids through histologic, molecular, and proteomic analysis, demonstrating their strong similarity to the primary tumor. We demonstrated that these tumoroids can be used as a drug screening model. In fact, we showed that paclitaxel, a human chemotherapeutic, could kill canine tumoroids with the same efficacy as human tumoroids with 0.1 to 1 µM of drug needed to kill 50% of the cells. Due to easy tissue availability, canine tumoroids can be produced at larger scale and cryopreserved to constitute a biobank. We have demonstrated that cryopreserved tumoroids keep the same histologic and molecular features (ER, PR, and HER2 expression) as fresh tumoroids. Furthermore, two cryopreservation techniques were compared from a proteomic point of view which showed that tumoroids made from frozen material allowed to maintain the same molecular diversity as from freshly dissociated tumor. CONCLUSIONS: These findings revealed that canine mammary tumoroids can be easily generated and may provide an adequate and more reliable preclinical model to investigate tumorigenesis mechanisms and develop new treatments for both veterinary and human medicine.

Long-Term High-Fat Diet Limits the Protective Effect of Spontaneous Physical Activity on Mammary Carcinogenesis.

Breast cancer is influenced by factors such as diet, a sedentary lifestyle, obesity, and postmenopausal status, which are all linked to prolonged hormonal and inflammatory exposure. Physical activity offers protection against breast cancer by modulating hormones, immune responses, and oxidative defenses. This study aimed to assess how a prolonged high-fat diet (HFD) affects the effectiveness of physical activity in preventing and managing mammary tumorigenesis. Ovariectomised C57BL/6 mice were provided with an enriched environment to induce spontaneous physical activity while being fed HFD. After 44 days (short-term, ST HFD) or 88 days (long-term, LT HFD), syngenic EO771 cells were implanted into mammary glands, and tumour growth was monitored until sacrifice. Despite similar physical activity and food intake, the LT HFD group exhibited higher visceral adipose tissue mass and reduced skeletal muscle mass. In the tumour microenvironment, the LT HFD group showed decreased NK cells and TCD8+ cells, with a trend toward increased T regulatory cells, leading to a collapse of the T8/Treg ratio. Additionally, the LT HFD group displayed decreased tumour triglyceride content and altered enzyme activities indicative of oxidative stress. Prolonged exposure to HFD was associated with tumour growth despite elevated physical activity, promoting a tolerogenic tumour microenvironment. Future studies should explore inter-organ exchanges between tumour and tissues.

Anticancer Effects of Mitoquinone via Cell Cycle Arrest and Apoptosis in Canine Mammary Gland Tumor Cells.

Treating female canine mammary gland tumors is crucial owing to their propensity for rapid progression and metastasis, significantly impacting the overall health and well-being of dogs. Mitoquinone (MitoQ), an antioxidant, has shown promise in inhibiting the migration, invasion, and clonogenicity of human breast cancer cells. Thus, we investigated MitoQ's potential anticancer properties against canine mammary gland tumor cells, CMT-U27 and CF41.Mg. MitoQ markedly suppressed the proliferation and migration of both CMT-U27 and CF41.Mg cells and induced apoptotic cell death in a dose-dependent manner. Furthermore, treatment with MitoQ led to increased levels of pro-apoptotic proteins, including cleaved-caspase3, BAX, and phospho-p53. Cell cycle analysis revealed that MitoQ hindered cell progression in the G1 and S phases in CMT-U27 and CF41.Mg cells. These findings were supported using western blot analysis, demonstrating elevated levels of cleaved caspase-3, a hallmark of apoptosis, and decreased expression of cyclin-dependent kinase (CDK) 2 and cyclin D4, pivotal regulators of the cell cycle. In conclusion, MitoQ exhibits in vitro antitumor effects by inducing apoptosis and arresting the cell cycle in canine mammary gland tumors, suggesting its potential as a preventive or therapeutic agent against canine mammary cancer.

Characterization of Hyaluronan Localization in the Developing Mammary Gland and Mammary Tumors.

The extracellular matrix (ECM) is biochemically and biomechanically important for the structure and function of the mammary gland, which undergoes vast structural changes throughout pubertal and reproductive development. Although hyaluronan (HA) is a ubiquitous glycosaminoglycan (GAG) of the mammary gland ECM, extensive characterization of HA deposition in the mammary gland is lacking. Understanding physiologic HA metabolism is critical as this tightly controlled system is often hijacked in cancer. In the current studies, we characterize HA regulation throughout mammary gland development to better understand subsequent dysregulation of HA in mammary tumors. Using immunofluorescence (IF) imaging, we demonstrate that organized HA-rich septa exist in the mammary gland stroma throughout puberty, pregnancy, and involution. Furthermore, we find heterogeneous HA deposition within two murine models of breast cancer. Using cell specific isolation techniques, we characterize expression of genes associated with HA binding, synthesis, and degradation within EpCAM + epithelial cells, CD90.2 + fibroblasts, and F4/80 + macrophages isolated from mammary glands and tumors. Most notably, we identify elevated levels of the hyaluronidases Hyal1 and Hyal2 in tumor-association macrophages (TAMs), suggesting a role for TAM-mediated turnover of HA in the tumor microenvironment (TME). Gene expression is supported functionally by in vitro experiments in which macrophages treated with tumor-cell conditioned media exhibit increased hyaluronidase activity. These findings link TAMs to the direct degradation of HA within the TME of mammary tumors, which has negative implications for patient survival.

CHMP4A stimulates CD8+ T-lymphocyte infiltration and inhibits breast tumor growth via the LSD1/IFNß axis.

CD8+ T lymphocyte-mediated immunity strategies have represented attractive weapons against breast cancer (BC) recently. However, the mechanisms underlying CD8+ T-lymphocyte infiltration still remain obscure. Here, using bioinformatics analysis, we identified four hub prognostic genes related to CD8+ T-lymphocyte infiltration (CHMP4A, CXCL9, GRHL2, and RPS29), among which CHMP4A was the most significant gene. High CHMP4A mRNA expression was significantly associated with longer overall survival (OS) in BC patients. Functional experiments showed that CHMP4A had the ability to promote CD8+ T-lymphocyte recruitment and infiltration and suppressed BC growth in vitro and in vivo. Mechanistically, CHMP4A stimulates CD8+ T-lymphocyte infiltration by downregulating LSD1 expression, leading to HERV dsRNA accumulation, and promoting IFNß and its downstream chemokine production. Collectively, CHMP4A is not only a novel positive predictor for prognosis in BC but also a stimulator of CD8+ T-lymphocyte infiltration regulated by the LSD1/IFNß pathway. This study suggests that CHMP4A may be a novel target for improving the effectiveness of immunotherapy in patients with BC.

Uncovering axes of variation among single-cell cancer specimens.

While several tools have been developed to map axes of variation among individual cells, no analogous approaches exist for identifying axes of variation among multicellular biospecimens profiled at single-cell resolution. For this purpose, we developed 'phenotypic earth mover's distance' (PhEMD). PhEMD is a general method for embedding a 'manifold of manifolds', in which each datapoint in the higher-level manifold (of biospecimens) represents a collection of points that span a lower-level manifold (of cells). We apply PhEMD to a newly generated drug-screen dataset and demonstrate that PhEMD uncovers axes of cell subpopulational variation among a large set of perturbation conditions. Moreover, we show that PhEMD can be used to infer the phenotypes of biospecimens not directly profiled. Applied to clinical datasets, PhEMD generates a map of the patient-state space that highlights sources of patient-to-patient variation. PhEMD is scalable, compatible with leading batch-effect correction techniques and generalizable to multiple experimental designs.

Research progress of good markers for canine mammary carcinoma.

PURPOSE: Mammary gland tumors are the most common neoplastic diseases in elderly female dogs, about 50% of which are considered to be malignant. Canine mammary tumors are similar to human breast cancers in many respects, so canine mammary tumors are frequently studied alongside human breast cancer. This article mentioned KI-67, HER-2, COX-2, BRCA1, BRCA2, P53, CA15-3, MicroRNA, Top2α and so on. All these markers are expected to have an important role in the clinic. METHODS: Existing markers of canine mammary carcinoma are reviewed, and the expression of each marker and its diagnostic role for this tumor are described in detail. RESULTS: This article introduced several effective markers of canine mammary tumors, among them, antigen KI-67 (KI-67), human epidermal growth factor receptor 2 (HER-2), cyclooxygenase 2 (COX-2) are promising and can be detected in both serum and tissue samples. Breast cancer caused by mutations in the breast cancer 1 gene (BRCA1) and breast cancer 2 gene (BRCA2) is also a hot topic of research. In addition to the above symbols, tumor protein p53 (p53), cancer antigen15-3 (CA15-3), MicroRNA (miRNA), topoisomerase πα (Top2α), proliferating cell nuclear antigen (PCNA), epidermal growth factor receptor (EGFR) and E-cadherin will also be involved in this paper. We will also mention Mammaglobin, which has been rarely reported so far.

Deregulation of scribble promotes mammary tumorigenesis and reveals a role for cell polarity in carcinoma.

Loss of cell polarity proteins such as Scribble induces neoplasia in Drosophila by promoting uncontrolled proliferation. In mammals, the role that polarity proteins play during tumorigenesis is not well understood. Here, we demonstrate that depletion of Scribble in mammary epithelia disrupts cell polarity, blocks three-dimensional morphogenesis, inhibits apoptosis, and induces dysplasia in vivo that progress to tumors after long latency. Loss of Scribble cooperates with oncogenes such as c-myc to transform epithelial cells and induce tumors in vivo by blocking activation of an apoptosis pathway. Like depletion, mislocalization of Scribble from cell-cell junction was sufficient to promote cell transformation. Interestingly, spontaneous mammary tumors in mice and humans possess both downregulated and mislocalized Scribble. Thus, we demonstrate that scribble inhibits breast cancer formation and that deregulation of polarity pathways promotes dysplastic and neoplastic growth in mammals by disrupting morphogenesis and inhibiting cell death.

Establishment and characterization of a HER2-enriched canine mammary cancerous myoepithelial cell line.

BACKGROUND: Canine mammary tumors (CMTs) have a poor prognosis, along with tumor recurrence and metastasis. Cell lines are vital in vitro models for CMT research. Many CMT epithelial cell lines were reported. However, canine mammary myoepithelial cells, the contractile component of the canine mammary tissue were overlooked. This study aimed at establishing such a cell line. CMT-1 cell line was obtained from a canine mammary tumor CMT-1 and characterized molecularly through qPCR, western blotting, immunochemistry and immunofluorescence. Its doubling time, cytogenetic analysis and migration rate were evaluated using growth study, karyotype analysis and wound healing assay respectively. To determine its tumorigenesis, xenograft transplantation was performed. RESULTS: CMT-1 tumor was a complex canine mammary carcinoma that stained negative to estrogen receptors (ER) and progesterone receptors (PR), but positive to human epidermal growth receptor-2 (HER2), defined as HER2-enriched subtype. In this study, a CMT-1 cell line obtained from CMT-1 tumor was immune-positive to vimentin, α-SMA, p63 and negative to E-cadherin (E-cad), indicating CMT-1 cells were myoepithelial cells. It was successfully cultured for more than 50 passages showing the same immunoreactivity to ER, PR, and HER2 as the primary canine tumor. The doubling time of CMT-1 cell line was 26.67 h. The chromosome number of CMT-1 cells ranged from 31 to 64. A potential spontaneous epithelial to mesenchymal transition (EMT) was noticed during cell cultures. Potential EMT-induced CMT-1 cells showed no significance in migration rate compared to the original CMT-1 cells. CMT-1 cells was able to grow on a 3D culture and formed grape-like, solid, and cystic mammospheres at different time period. Inoculation of CMT-1 cells induced a complex HER2-enriched mammary tumor with metastasis in mice. CONCLUSIONS: A canine cancerous HER2-enriched myoepithelial cell line was successfully established and a canine mammosphere developed from myoepithelial cells was documented in this study. We are expecting this novel cell line and its associated mammospheres could be used as a model to elucidate the role of myoepithelial cells in CMT carcinogensis in the future.