Mammary Carcinoma Tissue Research Articles

Dkk1 as a Prognostic Marker for Neoadjuvant Chemotherapy Response in Breast Cancer Patients.

To investigate the role of Dkk1 as a predictor of response to NACT in BC patients. This retrospective monocentric study included 145 women who had undergone NACT followed by breast surgery. Dkk1 protein expression was assessed using immunohistochemistry staining in core needle biopsies and mammary carcinoma specimens. Dkk1 levels were lower in treated BC tumours than in untreated tumours. The outcomes of 68 matched pre- and post-therapy tissues showed that Dkk1 levels in mammary carcinoma tissues were significantly predicted by levels in core needle biopsies and that Dkk1 expression was reduced in 83% of cases. Smaller cT stage, positive Her2 expression, and decreased Dkk1-IRS in core needle biopsy tissues were all independent predictors of regression grade (R4), according to Sinn. However, the percentage of Dkk1 expression differences prior to and following NACT had no effect on PFS or OS. In this study, we demonstrated for the first time that Dkk1 could be identified as an independent predictor of NACT response in BC patients, particularly those with TNBC. Further research with a multicentric expanded (pre-/post-therapy) sample set and better-defined populations in terms of molecular subtypes, therapy modality, and long-term follow-up is recommended to obtain more solid evidence.

Transcriptomic Profile of Canine Mammary Ductal Carcinoma

Dogs can be excellent models for spontaneous studies about breast cancers, presenting similarities in clinical behavior and molecular pathways of the disease. Thus, analyses of the canine transcriptome can identify deregulated genes and pathways, contributing to the identification of biomarkers and new therapeutic targets, benefiting humans and animals. In this context, this study aimed to determine the transcriptional profile of canine mammary ductal carcinoma and contribute to the clarification of the importance of deregulated molecules in the molecular pathways involved in the disease. Therefore, we used mammary ductal carcinoma tissue samples and non-tumor mammary tissue from the radical mastectomy of six female dogs. Sequencing was performed on the NextSeq-500 System platform. A comparison of carcinoma tissue and normal tissue revealed 633 downregulated and 573 upregulated genes, which were able to differentiate the groups by principal component analysis. Gene ontology analysis indicated that inflammatory, cell differentiation and adhesion, and extracellular matrix maintenance pathways were mainly deregulated in this series. The main differentially expressed genes observed in this research can indicate greater disease aggressiveness and worse prognosis. Finally, the study of the canine transcriptome indicates that it is an excellent model to generate information relevant to oncology in both species.

Pro-Apoptotic and Anti-Invasive Properties Underscore the Tumor-Suppressing Impact of Myoglobin on a Subset of Human Breast Cancer Cells.

The expression of myoglobin (MB), well known as the oxygen storage and transport protein of myocytes, is a novel hallmark of the luminal subtype in breast cancer patients and correlates with better prognosis. The mechanisms by which MB impacts mammary tumorigenesis are hitherto unclear. We aimed to unravel this role by using CRISPR/Cas9 technology to generate MB-deficient clones of MCF7 and SKBR3 breast cancer cell lines and subsequently characterize them by transcriptomics plus molecular and functional analyses. As main findings, loss of MB at normoxia upregulated the expression of cell cyclins and increased cell survival, while it prevented apoptosis in MCF7 cells. Additionally, MB-deficient cells were less sensitive to doxorubicin but not ionizing radiation. Under hypoxia, the loss of MB enhanced the partial epithelial to mesenchymal transition, thus, augmenting the migratory and invasive behavior of cells. Notably, in human invasive mammary ductal carcinoma tissues, MB and apoptotic marker levels were positively correlated. In addition, MB protein expression in invasive ductal carcinomas was associated with a positive prognostic value, independent of the known tumor suppressor p53. In conclusion, we provide multiple lines of evidence that endogenous MB in cancer cells by itself exerts novel tumor-suppressive roles through which it can reduce cancer malignancy.

Immunohistochemical Expression of p62 in Feline Mammary Carcinoma and Non-Neoplastic Mammary Tissue.

Simple SummaryThe p62 protein, also called sequestosome 1 (SQSTM1), is a ubiquitin-binding scaffold protein. The expression of p62 was statistically higher in carcinoma compared to non-neoplastic mammary glands. Our results, although preliminary, are similar to the results of breast cancer, therefore, also in the cat, p62 could be considered a possible oncotarget.The p62 protein, also called sequestosome 1 (SQSTM1), is a ubiquitin-binding scaffold protein. In human oncology, although the interest in the function of this protein is recent, the knowledge is now numerous, but its role in tumorigenesis is not yet clear. This preliminary study aims to evaluate the immunohistochemical expression of p62 in 38 cases of feline mammary carcinoma with different grades of differentiation and in 12 non-neoplastic mammary gland tissues, to assess the expression level and a possible correlation with malignancy. The expression of p62 was statistically higher in carcinoma compared to non-neoplastic mammary glands: 28 feline mammary carcinomas (73.7%) had a high p62 expression score, three (7.9%) had a moderate expression, while seven cases (18.4%) had a low expression. The grade of the differentiation of the carcinoma was not correlated with the p62 expression. This study represents the first approach in feline oncology that correlates p62 expression in feline mammary carcinoma. Our results, although preliminary, are similar to the results of human breast cancer, therefore, also in the cat, p62 could be considered a possible oncotarget.

Expression of LIN28A/B and Let-7 miRNAs in canine mammary carcinomas

ABSTRACT: LIN28 is a RNA-binding protein including two highly conserved homologous, LIN28A and LIN28B. Proto-oncogenes such as LIN28A and LIN28B are generally targeted by the let-7 miRNAs in different types of human cancers. Here, we determined the expression of LIN28A in canine mammary tumor samples and the LIN28/let-7 pathway in canine mammary cell lines. In those cell lines, we identified a functional LIN28/let-7 pathway which exhibited high expression of let-7 members and low expression of its targets, including LIN28A and LIN28B. However, the mammary carcinoma tissue samples showed a frequent expression of LIN28A being expressed mainly in the epithelial cells. No association was observed between LIN28A expression and histopathological classification and grade, TNM and survival time. Our results suggested a possible role of the LIN28A protein in the development of canine mammary carcinomas due to the high frequency observed in the tumor samples (28 of 32). The in vitro experiments suggested that the LIN28/let-7 pathway is active in the tumor cells evaluated. However, more studies are necessary to elucidate the exact role of LIN28/let-7 pathway in canine mammary carcinomas.

Assessing the viability of carbamoylethyl pullulan-g-stearic acid based smart polymeric micelles for tumor targeting of raloxifene

The present investigation entails the synthesis of smart pullulan polymeric micelles for evaluating its tumor targeting potential. For this purpose, two step polymerization synthesis reactions were conducted. In the first step, carbamoylethylation occurs by reaction of the free alcoholic moieties at 6th position of glucopyranose unit of pullulan with acrylamide in presence of alkali to obtain carbamoylethyl pullulan (CmP). In the second step, CmP undergoes graft polymerization with stearic acid (SA) to obtain CmP-g-stearic acid diblock co-polymer (CmP-g-SA) as evident from FTIR and NMR analysis. The XpRD spectra showed crystalline nature that was further confirmed by SEM indicating rough and poly-porous morphology. The QbD based optimized formulations of raloxifene HCl (RLX) loaded polymeric micelles (RLX PMs) exhibited pH-dependent release profile with added advantage of 1.2 times reduction in percentage hemolysis giving substantial compatibility with erythrocytes. In vivo pharmacokinetic performance of RLX PMs suggested enhanced mean residence time and volume of distribution. Besides, the biodistribution study of RLX PMs manifested enhanced entry of RLX in mammary carcinoma tissues as compared to normal tissues suggested that CmP-g-SA based micelles enhanced the anti-tumor activity of RLX. Overall, the findings pointed toward the biocompatibility of CmP-g-SA as a potential carrier system for the delivery of RLX.

Abstract LB-095: Aurora-A is elevated in cancer cells due to inactivation of EF1A2-PTEN-GSK3b regulated late S-G2 phase specific degradation pathway

Abstract Elevated expression of Aurora kinase-A oncoprotein is detected in a subset of human cancers across different organ sites. The mechanism(s) underlying over expression of the protein in cancer cells have not been well elucidated. This study demonstrates that inactivation of a novel mechanism of EF1A2 regulated PTEN-GSK3β-SCF complex mediated Aurora-A protein degradation pathway in S-G2 phases of mitosis leads to enhanced stability/steady state level of Aurora-A in cancer cells. EEF1A2 regulates interaction of Aurora-A with activated PTEN, GSK3β, Neddylated CUL1 and FBXW7, promoting ubiquitination mediated degradation of Aurora-A that is rescued in EEF1A2 knockdown cells. Ectopic expression of EEF1A2, on the other hand, enhances formation of the complex with GSK3β mediated inactivating phosphorylation and reduction in Aurora-A protein, recapitulating the S-G2 phase events. Genetic ablation of EEF1A2 and PTEN in both in vitro cell lines and in vivo mouse models validated the results. Aurora-A over expressing mouse models of mammary carcinoma and human breast cancer tissue samples also corroborated the findings. Therapeutic targeting of PTEN-GSK3β-AKT pathway may, therefore, be effective in treating a subset Aurora-A over expressing cancers. Citation Format: Warapen Treekitkarnmongkol, Luisa Maren Solis, Kazuharu Kai, Kaori Sasai, Ignacio I. Wistuba, Aysegul A. Sahin, Kwong K. Wong, Alastair M. Thompson, Yoshimi Jltsumori, Jonathan M. Lee, Lidong Qin, Tasneem Bawa-Khalfe, Roland Rad, Catherine M. Abbott, Hiroshi Katayama, Subrata Sen. Aurora-A is elevated in cancer cells due to inactivation of EF1A2-PTEN-GSK3b regulated late S-G2 phase specific degradation pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-095.

Incidence of Human Cytomegalovirus in Breast Carcinoma Tissues is Associated with A Higher Expression of Growth Factor Receptor-Bound Protein 2

Background: female mammary carcinoma is the second most common cancer incidence among women and the fifth most common leading cause of cancer death worldwide. Premenopausal young women are more frequently targeted by inflammatory breast cancer (IBC), which is the most lethal form of breast cancer. The human cytomegalovirus (HCMV) has been identified as one of the viral infection with a higher frequency in carcinoma tissues of IBC than in non-IBC. The adaptor protein growth factor receptor-bound protein 2 (Grb2), was found to be upregulated in HCMV-infected cells and play as crucial role in cancer progression. Objective: this study aimed to assess the expression level of Grb2 in carcinoma tissues of IBC and non-IBC with HCMV infection. Patients and Methods: overall, 135 female diagnosed with breast carcinoma were enrolled in this study. Using conventional and real time polymerase chain reaction (PCR), we determined the incidence of HCMV and assessed the expression level of Grb2 mRNA in the breast cancer tissue samples. Results: Grb2 mRNA was significantly upregulated in HCMV+ IBC higher than in HCMV+ non-IBC. According to the molecular subtype, Grb2 mRNA was significantly higher upregulated in breast carcinoma tissues of HCMV+ hormonal positive (HP) than in triple negative (TN) counterparts. Conclusion: HCMV infection is associated with a high expression of Grb2 mRNA in IBC and that HP HCMV+ mammary carcinoma tissues confer upregulated Grb2 mRNA, suggesting a potential role of HCMV infection in enhancing of Grb2 mRNA expression in breast cancer with HP.

Epidemiological study on cancer patents in Bulgaria and the Plovdiv region and the application of bisphosphonates on patients with malignancies in the Plovdiv region

Introduction Bisphosphonates (BP) have been used for several decades for the treatment of multiple myeloma, bone metastases, osteoporosis, Paget disease and others. In recent years, reports of Bisphosphonate-associated osteonecrosis of the jaw (BAONJ) have increased, most often in oncological patients (breast cancer, prostate cancer, lung cancer and multiple myeloma) receiving intravenous BP. This is an extremely difficult and multifactorial process requiring monitoring and individual approach to each patient. Aim To conduct an epidemiological study of patients with oncological diseases in Bulgaria and in the Plovdiv region and to study the application of intravenous BP in patients with malignancies in the Plovdiv region. Materials and methods Official information on the total number of patients with neoplasms and the number of newly discovered neoplasms in Bulgaria and Plovdiv region is provided from the National Cancer Registry (NRC) of Bulgaria for the period 2012–2016 (5-year period). From the pharmacies of the hospitals in the Plovdiv region, where BP therapy is administered, was provided information on the oncology patients who received intravenous BP by years for the same period. Results In Bulgaria, from 2012 to 2016, were registered between 270,942 and 285,776 neoplasms per year, with an upwards trend, and with a significantly higher proportion of women. An average of 30,235 newly registered neoplasms per year have been registered, with a decreasing tendency of the number of cases. On average, the number of newly registered females for the period is 14,668 and for men - 15,567, with the proportion of men being credibly higher. In the region of Plovdiv, for the period an average of 35,634 neoplasms were registered per year, with a tendency for cases to grow, and with a significantly higher proportion of women. Newly registered cases in the region are an average of 3553, with a tendency to decrease the number of cases. On average, the newly registered males were 1908 and the females 1644, with an increase in the number of men and a decrease in the number of women, and a significantly higher proportion of men. In Bulgaria, and in the Plovdiv reign, the most common localizations of malignancy for the 5-year period are: skin, mammary gland, female genital organs, digestive organs and respiratory organs. In the country and the district of Plovdiv, for the cases of breast and prostate cancer, there was an increase for the 5-year study. For the period, in the Plovdiv region, an average of 2.30% of cancer patients received BP, with a higher proportion of women, and a median of age from 63 (2012) to 68 (2016). Most of the BP receiving oncology patients were between 61–70 and 71–80 years old. Zoledronic acid is administered between 98.77% and 100.00% of the cases. In the Plovdiv region, the application of BP has the highest relative proportions in mammary carcinoma, lymphatic, hematopoietic and related tissues, prostate and lung cancer. There is a decline in the median of the number of applications of BF from an average of 5 to 3 per year in 2015 and 2016, with women receiving more infusions than men. Conclusion Oncological diseases, both in Bulgaria and in the Plovdiv region, have an upward trend, especially in the cases of mammary carcinoma and prostate cancer, which means an increase in patients with a potential need of BP therapy. The patients treated with BP in the Plovdiv region have an increasing tendency of age, and are treated mainly with Zoledronic acid, which increases the risk of developing BAONJ.

Development of an Innovative Cell Isolation Method for the Investigation of Breast Cancer Pathogenesis and Angiogenesis for Experimental In Vitro And In Vivo Assays

Background Breast cancer is the world's most common cancer among women. Autologous lipotransfer is increasingly used for breast reconstruction following surgical removal of the tumour. In cell-assisted lipotransfer, the transplant is enriched with stem cells from adipose tissue (ADSC). Despite positive clinical results, there are some concerns regarding oncological safety due to transplanted stem cells. To date there are only a few breast cancer studies using primary cells from the same patient to enable further investigation into the complexity of cell-cell interactions in breast cancer in an experimental setting. Materials and methods We performed literature research on the topic of autologous lipotransfer. 5 different cell types (epithelial, mesenchymal cells, ADSC, endothelial cells, endothelial progenitor cells) were isolated from mammary (carcinoma) tissue or blood and were subsequently characterised for gene and protein expression as well as functional properties. The arteriovenous (AV) loop model in the rat was evaluated as a possible in vivo model for breast cancer pathogenesis and angiogenesis in this study. Results The literature provided evidence for an in-vitro interaction between ADSC and cells of the mammary (carcinoma) tissue. In some clinical studies, certain subgroups of patients appeared to be exposed to an increased risk of tumour recurrence after lipotransfer, but in most studies no correlation between lipotransfer and tumour recurrence was found. Different cell populations, which differed significantly in terms of surface markers, gene expression and functional properties, were isolated from tissue of the same patient. Axial vascularised tissue was successfully generated in the AV loop model. Conclusion In this study we were able to isolate different cell populations from the same patient, which reflect the heterogeneity of the tumour tissue. This enables a precise analysis of cell-cell interactions and their effects on tumour angiogenesis and pathogenesis in breast cancer. In combination with the AV loop model, this offers new possibilities to generate vascularised mammary carcinoma tissue as well as healthy mammary gland tissue in vivo as an optimal model for the clinical setting.

Abstract A61: Cell cycle regulated centrosome orientation during directed migration requires Aurora Kinase A

Abstract Cell cycle progression and the acquisition of a migratory phenotype are hallmarks of human carcinoma cells. Here we report a strong correlation between cell cycle progression into G2 phase and an increased migratory velocity for non-malignant, immortalized mammary epithelia nMuMG (Mus musculus mammary gland) cells, or malignant cervical carcinoma HeLa cells, expressing a fluorescent ubiquitin cell cycle indicator and quantified in wound closure assays with high content multi-parameter live cell imaging. Cells at the wound edge exhibited elevated microtubule nucleation capacity at centrosomes, and a reduction of this capacity through inhibition of aurora kinase A was sufficient to impair migration velocity without affecting cell cycle dynamics. In migratory cells, active aurora kinase A at the centrosome correlated with nucleation capacity. In clinically annotated mammary carcinoma tissues (n=3,992), aurora kinase A activity, as assessed by the abundance of phosphorylated-RHAMM (Receptor for Hyaluronan Mediated Motility) was a significant predictor of breast cancer specific survival and relapse free survival in patients with estrogen receptor negative breast cancer (n= 941), triple negative phenotype breast cancer (n= 538) or basal-like subtype breast cancer (n= 293), but not in those patients with estrogen receptor positive breast cancer (n= 2,218). In estrogen receptor negative tumors from patients that received no adjuvant systemic therapy (n= 453), the levels of phosphorylated-RHAMM associated with the presence of distal nodal metastasis and predicted a subset of patients at high risk of recurrence. Together, these data identify aurora kinase A activity as a regulatory pathway that intersects cell cycle progression and cell migration, with potential to influence the metastasis of estrogen receptor negative breast tumors and patient survival. Citation Format: Tony LH Chu, Jennifer Won, Oksana Nemirovsky, Abbas Fotovati, Torsten Nielsen, Christopher A Maxwell. Cell cycle regulated centrosome orientation during directed migration requires Aurora Kinase A. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A61.

ChemInform Abstract: Mucin Glycopeptide‐Protein Conjugates — Promising Antitumor Vaccine Candidates

AbstractReview: [54 refs.

Mucin Glycopeptide‐Protein Conjugates – Promising Antitumor Vaccine Candidates

AbstractRecent efforts towards the development of synthetic glycopeptide vaccines, which aim at the active immunization of patients against their own tumor tissues, are outlined. To achieve sufficient tumor selectivity, glycopeptides of the tandem repeat region of tumor‐associated mucin, MUC1, have been synthesized. Since the endogenous structures usually exert low immunogenicity, these glycopeptide antigens, as B‐cell epitopes, were conjugated with immunostimulating components. In the present short review, work is outlined in which the MUC1 B‐cell epitope peptides are conjugated with bovine serum albumin (BSA), keyhole limpet hemocyanin (KLH), or tetanus toxoid (TTox). In particular, the synthetic vaccines based on tetanus toxoid induce very strong tolerance‐breaking immune responses in mice. The induced antibodies of the IgG type indicate the installation of an immunological memory. In addition, these antibodies strongly bind to human breast tumor cells in culture, demonstrated by flow cytometry experiments, and also to the tumor cells in mammary carcinoma tissues.

Cks1 proteasomal turnover is a predominant mode of regulation in breast cancer cells: role of key tyrosines and lysines.

Constitutive levels of Cks1 protein are very high in mammary carcinoma tissue and in breast tumor cell lines. However, despite being transcribed at relatively high levels, Cks1 protein is very low in normal mammary tissue. Also, basal Cks1 is barely detectable in primary human mammary epithelial cells (HMECs). Epoximicin, a proteasome inhibitor, induced detectable endogenous Cks1 in HMECs, and upregulated it above the basal level in MCF-7 breast cancer cells. Interestingly, transiently transfected Cks1 is remarkably unstable and accumulates only upon proteasomal blockade in multiple cell lines even when driven by the strong CMV promoter-enhancer. We examined the stability of site-directed Cks1 mutants in order to identify the structural determinants of its turnover in cancer cells. Since protein turnover is regulated by phosphorylation, and phosphoproteomic studies reveal phosphorylated tyrosines in Cks1, we replaced its five conserved tyrosines (Y) with phenylalanine (F), both individually and in combinations. We find that like wild-type, all transiently transfected mutant Cks1 vectors, even when driven by the CMV promoter-enhancer, expressed detectable protein only in cells treated with epoximicin. However, turnover of the Y8F, Y12F and Y19F Cks1 mutants was more rapid than that of wild-type, Y7F and Y57F. Since lysines are modified by ubiquitination or acetylation we also examined the consequences of lysine to arginine (K-R) substitutions on Cks1 proteasomal turnover. We found that the individual mutations K4R, K26R, K30R, and K34R slowed Cks1 turnover, while the K79R mutation or the combined mutation K75-76-78-79R increased turnover. Taken together, regulation of Cks1 protein stability is crucially dependent on specific tyrosine and lysine residues which are potential sites for post-translational modifications.

Probing the biophysical properties of primary breast tumor-derived fibroblasts.

As cancer progresses, cells must adapt to a new and stiffer environment, which can ultimately alter how normal cells within the tumor behave. In turn, these cells are known to further aid tumor progression. Therefore, there is potentially a unique avenue to better understand metastatic potential through single-cell biophysical assays performed on patient-derived cells. Here, we perform biophysical characterization of primary human fibroblastic cells obtained from mammary carcinoma and normal contralateral tissue. Through a series of tissue dissociation, differential centrifugation and trypsinization steps, we isolate an adherent fibroblastic population viable for biomechanical testing. 2D TFM and 3D migration measurements in a collagen matrix show that fibroblasts obtained from patient tumors generate more traction forces and display improved migration potential than their counterparts from normal tissue. Moreover, through the use of an embedded spheroid model, we confirmed the extracellular matrix (ECM) remodeling behavior of primary cells isolated from carcinoma. Overall, correlating biophysical characterization of normal- and carcinoma-derived samples from individual patient along with patient outcome may become a powerful approach to further our comprehension of metastasis and ultimately design drug targets on a patient-specific basis.

Macrophages Mediate a Switch between Canonical and Non-Canonical Wnt Pathways in Canine Mammary Tumors

ObjectiveAccording to the current hypothesis, tumor-associated macrophages (TAMs) are “corrupted” by cancer cells and subsequently facilitate, rather than inhibit, tumor metastasis. Because the molecular mechanisms of cancer cell–TAM interactions are complicated and controversial we aimed to better define this phenomenon.Methods and ResultsUsing microRNA microarrays, Real-time qPCR and Western blot we showed that co-culture of canine mammary tumor cells with TAMs or treatment with macrophage-conditioned medium inhibited the canonical Wnt pathway and activated the non-canonical Wnt pathway in tumor cells. We also showed that co-culture of TAMs with tumor cells increased expression of canonical Wnt inhibitors in TAMs. Subsequently, we demonstrated macrophage-induced invasive growth patterns and epithelial–mesenchymal transition of tumor cells. Validation of these results in canine mammary carcinoma tissues (n = 50) and xenograft tumors indicated the activation of non-canonical and canonical Wnt pathways in metastatic tumors and non-metastatic malignancies, respectively. Activation of non-canonical Wnt pathway correlated with number of TAMs.ConclusionsWe demonstrated that TAMs mediate a “switch” between canonical and non-canonical Wnt signaling pathways in canine mammary tumors, leading to increased tumor invasion and metastasis.Interestingly, similar changes in neoplastic cells were observed in the presence of macrophage-conditioned medium or live macrophages. These observations indicate that rather than being “corrupted” by cancer cells, TAMs constitutively secrete canonical Wnt inhibitors that decrease tumor proliferation and development, but as a side effect, they induce the non-canonical Wnt pathway, which leads to tumor metastasis.These data challenge the conventional understanding of TAM–cancer cell interactions.

Application of 2D‐DIGE to formalin‐fixed diseased tissue samples from hospital repositories: Results from four case studies

In the recent past, the potential suitability of fixed samples to 2D-DIGE studies has been demonstrated on model tissues, but not on "real-world" archival tissues. Therefore, this study was aimed to assess the quality of the results delivered by 2D-DIGE on samples retrieved from hospital tissue repositories. Diseased and normal tissue samples (namely, human gastric adenocarcinoma and normal gastric tissue, human lung neuroendocrine tumors, canine mammary tubulo-papillary carcinoma and normal mammary tissue, sheep liver with cloudy swelling degeneration and normal liver tissue) were retrieved from human and veterinary biorepositories and subjected to full-length protein extraction, cyanine labeling, 2D-DIGE separation, image analysis, MS analysis, and protein identification. Archival samples could be successfully subjected to 2D-DIGE, providing maps of satisfactory resolution, although with varying pattern complexity (possibly influenced by preanalytical variables). Moreover, differentially expressed protein identities were consistent with the disease biology. 2D-DIGE can support biomarker discovery and validation studies on large sample cohorts. In fact, although some information complexity is lost when compared to fresh-frozen tissues, their vast availability and the associated patient information can considerably boost studies suffering limited sample availability or involving long-distance exchange of samples.

Transcriptomic classification of genetically engineered mouse models of breast cancer identifies human subtype counterparts

BackgroundHuman breast cancer is a heterogeneous disease consisting of multiple molecular subtypes. Genetically engineered mouse models are a useful resource for studying mammary cancers in vivo under genetically controlled and immune competent conditions. Identifying murine models with conserved human tumor features will facilitate etiology determinations, highlight the effects of mutations on pathway activation, and should improve preclinical drug testing.ResultsTranscriptomic profiles of 27 murine models of mammary carcinoma and normal mammary tissue were determined using gene expression microarrays. Hierarchical clustering analysis identified 17 distinct murine subtypes. Cross-species analyses using three independent human breast cancer datasets identified eight murine classes that resemble specific human breast cancer subtypes. Multiple models were associated with human basal-like tumors including TgC3(1)-Tag, TgWAP-Myc and Trp53-/-. Interestingly, the TgWAPCre-Etv6 model mimicked the HER2-enriched subtype, a group of human tumors without a murine counterpart in previous comparative studies. Gene signature analysis identified hundreds of commonly expressed pathway signatures between linked mouse and human subtypes, highlighting potentially common genetic drivers of tumorigenesis.ConclusionsThis study of murine models of breast carcinoma encompasses the largest comprehensive genomic dataset to date to identify human-to-mouse disease subtype counterparts. Our approach illustrates the value of comparisons between species to identify murine models that faithfully mimic the human condition and indicates that multiple genetically engineered mouse models are needed to represent the diversity of human breast cancers. The reported trans-species associations should guide model selection during preclinical study design to ensure appropriate representatives of human disease subtypes are used.

Abstract 1950: LHRH Peptide decorated cross-linked micelles for the targeted drug delivery to breast cancer

Abstract We have recently developed a series of micellar nanoparticles (NPs) based on linear polyethylene glycol (PEG) and dendritic cholic acids (CA) block copolymer (telodendrimer), for the targeted delivery of chemotherapeutic drugs in the treatment of cancers. The tumor targeting specificity and efficiency of drug-loaded NPs might be further improved by the decoration of cancer cell surface targeting ligands. LHRH (Luteinizing hormone releasing hormone), a natural hormone peptide, is able to bind specifically to the LHRH receptor, which has been reported to be over-expressed in more than 50% breast cancer patients. In the present study, we incorporated the passive targeting of our micellar NPs and the active targeting of LHRH peptide into a single platform with an attempt to further improve the therapeutic index of NPs delivered drugs in the treatment of breast cancer. We synthesized the LHRH peptide on the tentagel resin bead via the solid-phase peptide synthesis method, and demonstrated that human breast cancer cell lines MDA-MB-231 and MDA-MB-435 were able to bind strongly with LHRH peptide beads. Besides breast cancer cell lines, immunohistochemistry staining further demonstrated LHRH peptide was able to specifically bind to human breast tumor tissue as well as transgenic murine mammary carcinoma tissue, but not to normal breast tissue. Alkyne-containing LHRH peptides were successfully conjugated to the azide group at the distal PEG terminus of PEG5k-Cys4-L8-CA8 telodendrimer (cross-linked micelle forming unit) via the “click chemistry”. LHRH peptide ligand significantly enhanced the intracellular delivery of cross-linked micelles in both MDA-MB-231 and MDA-MB-435 breast cancer cells. In addition, the enhanced uptake of LHRH-targeted micelles in those cells can be inhibited by the addition of access of LHRH antibody, indicating the LHRH receptor-medicated internalization. The co-localization of internalized FITC-labeled LHRH-micelles with lysosomal compartment in human breast cancer cells were also observed, suggesting that the endocytosis pathway is likely to be involved in the internalization process. Furthermore, when loaded with paclitaxel (PTX), LHRH-micelles had significantly higher in vitro cellular toxicities against breast cancer cells as compared with the non-targeted micelles. The in vivo biodistribution, tumor targeting specificity and therapeutic efficacies of LHRH targeted micelles in MDA-MB-231 xenograft mouse model are currently under investigation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1950. doi:1538-7445.AM2012-1950

Correlation of Foxp3 positive regulatory T cells with prognostic factors in canine mammary carcinomas

Regulatory T cells (Treg) cells play a crucial role in tumor progression by suppressing anti-tumor immunity, but are not well-documented in veterinary oncology. To identify the characteristics of Treg cells in tumor microenvironments, the numbers of Treg cells were analyzed and compared with histological prognostic factors and molecular biomarkers in canine mammary carcinoma (MC) tissues (n=37). Abundant Treg cells were associated with high histological grade and lymphatic invasion. The numbers of Treg cells infiltrating intratumoral areas markedly increased in tumors with poor prognostic factors, such as high histological grade, lymphatic invasion, and necrosis. These findings suggest that Treg cells play a role in canine MC progression. Furthermore, Treg cell numbers in intratumoral compartments may provide a potential prognostic factor when assessing canine MCs, which may in turn lead to the development of new immunologic therapeutics.