Immune Cells and Immunoglobulin Expression in the Mammary Gland Tumors of Dog

Inflammatory cells have a role in tumor progression and have prognostic and therapeutic potential. The immunohistochemical expression for Mast Cell Tryptase, Macrophage Marker, CD79a, IgA, IgM and IgG on 43 cases of canine mammary gland lesions was analyzed. In hyperplasia, a few B cells (BCs) and Tumor-Associated Macrophages (TAMs) were observed, while the number of Tumor-Associated Mast Cells (TAMCs) was the highest. In the peritumoral stroma of malignant lesions, low number of TAMCs and a high number of TAMAs and BCs were present. Immune cells of each type were always lower in the intratumoral than peritumoral stroma. Positivity to CD79a was also detected in the epithelial cells of simple and micropapillay carcinomas. Immunoglobulin reactivity was mainly located in the epithelial cells where an intense positivity to IgA and IgG and a weak positivity for IgM were detectable. On the basis of our preliminary results and literature data, we suggest that such cells and molecules could be directly involved in the biology of canine mammary gland tumors. In breast cancer, stromal inflammatory cells and cancer derived immunoglobulins have been correlated with the progression, malignancy and poor prognosis of the tumor. The results herein reported show that the dog’s mammary gland epithelium also expresses immunoglobulins, and they mostly show a direct relationship with the infiltration of macrophages. In addition, this study shows that the infiltration of mast cells, B-cells and macrophages varies depending on the degree of malignancy of neoplasia.

Equine Penile Squamous Cell Carcinomas as a Model for Human Disease: A Preliminary Investigation on Tumor Immune Microenvironment

Penile squamous cell carcinomas (SCCs) are common tumors in older horses, with poor prognosis mostly due to local invasion and recurrence. These tumors are thought to be mainly caused by Equus caballus papillomavirus type 2 (EcPV-2). The aim of this study is to characterize the tumor immune environment (TIME) in equine penile tumors. Equine penile epithelial tumors (17 epSCCs; 2 carcinomas in situ, CIS; 1 papilloma, P) were retrospectively selected; immune infiltrate was assessed by histology and immunohistochemistry; RT-qPCR tested the expression of selected chemokines and EcPV-2 DNA and RNA. The results confirmed EcPV-2-L1 DNA in 18/20 (90%) samples. L1 expression was instead retrieved in 13/20 cases (65%). The samples showed an increased infiltration of CD3+lymphocytes, macrophages (MAC387; IBA1), plasma cells (MUM1), and FoxP3+lymphocytes in the intra/peritumoral stroma when compared to extratumoral tissues (p < 0.05). Only MAC387+neutrophils were increased in EcPV-2high viral load samples (p < 0.05). IL12/p35 was differentially expressed in EcPVhigh and EcPVlow groups (p = 0.007). A significant decrease of IFNG and IL2 expression was highlighted in TGFB1-positive samples (p < 0.05). IBA1 and CD20 were intratumorally increased in cases where IL-10 was expressed (p < 0.005). EpSCCs may represent a good spontaneous model for the human counterpart. Further prospective studies are needed in order to confirm these preliminary results.

Ultrastructural peculiarities in basal cell carcinoma

The last decade was marked by a statistically significant increase in the incidence of skin cancers, which motivated the development of new studies to later understand the behavior of these pathologies developing new therapeutic approaches. Also, the multitude of premalignant lesions as well as the complex classification of the carcinomas required a more accurate differentiation of the differential diagnosis, and in this regard the present electron microscopic study contributes significantly. A tumor is a very complex ecosystem represented in particular by (1) genetically modified neoplastic cells and (2) tumor stroma represented by (a) various other cell types (fibroblasts, fibrocytes, mast cells, inflammatory cells, endothelial cells, myelinated or non-myelinated nerves, etc.), and (b) extracellular matrix (basal lamina, elastic fibers and collagen, but also soluble molecules) [1]. The purpose of this study was to discover new aspects of ultrastructure that occur in basal cell carcinoma cases investigated by us, related to the capacity of invasiveness of these tumors. Fresh tumor fragments were obtained with the informed consent of the patients. Here we present some peculiar aspects concerning infrastructure of tumor cells involved in invasive process, especially desmosomal and hemidesmosomal junctions, invadopodia and shedding membrane vesicles. Moreover, here we report about new described cell phenotype termed telocytes involved in cell signaling by their homo- and heterocellular contacts. Telocytes from basal cell carcinoma stroma exhibit a reduced number of heterocellular contacts, which suggests a possible perturbation of tissue homeostasis modulation. Electron microscopic investigations revealed that in invasive basal cell carcinoma intercellular junctions, namely desmosomes are severely altered and that the tumor cells generate and disseminate membrane vesicles, including exosomes inside of the peritumoral stroma. Using transmission electron microscopy to investigate invasive basal cell carcinoma, we have managed to determine the relevance of all these changes for the purpose of evaluation of the invasive capacity of tumor cells within the peritumoral stroma.

Chemokine Expression Is Involved in the Vascular Neogenesis of Ewing Sarcoma: A Preliminary Analysis of the Early Stages of Angiogenesis in a Xenograft Model

Background Ewing sarcoma (EWS) is the second most common bone cancer in pediatric patients. Angiogenesis is a major factor for tumor growth and metastasis. Our aim was to carry out a histological, immunohistochemical, and molecular characterization of the neovascularization established between xenotransplanted tumors and the host during the initial phases of growth in nude mice in three angiogenesis experiments (ES2, ES3, and ES4). Methods The original human EWS were implanted subcutaneously on the backs of three nude mice. Tumor pieces 3 mm–4 mm in size from early passages of Nu432, Nu495, and Nu471 were also implanted subcutaneously on the backs of three sets (ES2, ES3, and ES4) of athymic Balb-c nude mice (n = 14 each). The animals were sacrificed at 24, 48, and 96 hours and at 7, 14, 21, and 28 days after implantation to perform histological, immunohistochemical, and molecular studies (neovascularization experiments). Results We observed histological, ultrastructural, and immunohistochemical changes in the xenografted tumor at different times after implantation. Chemokine ligand expression peaked twice, once during the first 48 hours and again in the second week. We observed that tumor cells in contact with murine peritumoral stroma presented higher expression of chemokine ligands as well as more tumor cells around the capillary vessels. Mouse serum vascular endothelial growth factor levels peaked twice, once in the first hours and then in the second week after tumor implantation. Conclusion Chemokines and other angiogenic factors may be relevant in the angiogenic mechanism during tumor growth. This model provides information on the early stages of the angiogenic process and could be a useful tool in researching anti-angiogenic drugs for new therapeutic strategies in EWS.

Correlation of MTOR protein expression in the tumor and its microenvironment with more aggressive pathology at cystectomy.

438 Background: The mechanistic target of rapamycin (mTOR) has been implicated in driving tumor biology in multiple malignancies, including urothelial carcinoma (UC). We investigate how mTOR and phosphorylated mTOR (pmTOR) protein expression in both the tumor, and the tumor microenvironment, correlate with final pathologic stage at cystectomy after neoadjuvant chemotherapy (NAC). Methods: A single-institution retrospective analysis was performed on 62 patients with cT2-4Nany UC undergoing NAC followed by radical cystectomy. Diagnostic (transurethral resection specimens, TURBT) and post-NAC radical cystectomy specimens were evaluated for mTOR and pmTOR protein expression using immunohistochemistry of the tumor, peritumoral stroma, and normal surrounding tissue. Protein expression levels were compared between TURBT and cystectomy samples. Whole transcriptome analysis was performed to evaluate mRNA expression relative to mTOR pathway activation. Results: Baseline levels of mTOR and pmTOR within TURBT specimens were not associated with clinical stage or response to NAC overall. Non-responder patients, defined as pT2-T4/pTanyN+, had significantly elevated mTOR tumor staining (p = 0.006) and sustained mTOR and pmTOR staining in the peritumoral and surrounding normal stroma of cystectomy specimens compared with baseline TURBT samples (NS). In contrast, complete responders (pT0), had significant decreases in tumoral mTOR and pmTOR protein expression at cystectomy (p = 0.01-0.03). Several genes relevant to mTOR activity were found to be overexpressed in post-NAC cystectomy samples (compared with TURBT) of non-responder patients (THBS1, FN1, FOS, CNN1, COL1A2). Conclusions: Our results suggest that mTOR pathway activity is increased in the tumor and sustained the tumor microenvironment of patients with adverse pathologic findings at cystectomy after NAC. These findings suggest the relevance of targeting the mTOR pathway in bladder cancer.

Cathepsin K Expression in Castration-Resistant Prostate Carcinoma: A Therapeutical Target for Patients at Risk for Bone Metastases

Background The lysosomal cysteine protease cathepsin K is involved in bone remodeling and is also expressed in the peritumoral stroma of carcinomas arising from different organs. A new generation of cathepsin K inhibitors blocking the RANKL/RANK pathway are being developed. We sought to investigate cathepsin K expression in a cohort of castration-resistant prostate carcinomas. Methods Sixteen cases of castration-resistant disease with at least 5 years of follow-up were selected from a cohort of 280 patients who underwent surgery. Cathepsin K was evaluated on formalin-fixed and paraffin-embedded tissue microarrays with 5 tissue spots per case. These were scored as high 2+ (≥30% of cells), low 1+ (<30% of cells) or zero (absence), distinguishing tumor cells and peritumoral stroma cells. Low (1+) and absence (0) of scoring were interpreted as negative, and high (2+) as positive. Results The castration-resistant group was composed of 15 acinar adenocarcinomas and 1 neuroendocrine carcinoma, and all showed at least Gleason score 8 at prostatectomy. Two out of 16 cases (12%) scored positive for cathepsin K in tumor cells; and 5 of 16 cases (31%) scored positive in peritumoral stroma cells. The neuroendocrine and acinar subtypes of carcinoma with positive immunoexpression in neoplastic cells developed bone metastases after 4 and 5 years, respectively, and subsequently died. Conclusions Patients affected by castration-resistant prostate carcinoma may be tested for cathepsin K, and a positive strong expression (2+) could be a useful predictive biomarker of response to targeted agents, aiding in the selection of patients eligible for these treatments.

Expressions of Matrix Metalloproteinases 2, 7, and 9 in Carcinogenesis of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal disease, usually diagnosed in an advanced stage which gives a slight chance of recovery. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that participate in tissue remodeling and stimulate neovascularization and inflammatory response. The aim of the study was to evaluate the expression of MMP-2, MMP-7, and MMP-9 in normal ducts, tumor pancreatic adenocarcinoma cells, and peritumoral stroma in correlation with clinicohistopathological parameters. The study material was obtained from 29 patients with pancreatic ductal adenocarcinoma. The expressions of MMP-2, MMP-7, and MMP-9 were performed by immunohistochemical technique. Microvessel density (MVD) was visualized by special immunostaining. The expressions of MMP-2, MMP-7, and MMP-9 were mainly observed in tumor cells and peritumoral stroma. MMP-2 expression in cancer cells was correlated with female gender, stronger inflammation, and histopathological type of cancer (R=0.460,p=0.013;R=0.690,p=0.0001;R=-0.440,p=0.005, resp.). The expression of MMP-7 in tumor cells was found to positively correlate with the presence of necrosis and negatively correlate with MVD (R=0.402,p=0.031;R=-0.682,p=0.000). We also showed that positive MMP-9 expression in tumor cells was associated with MVD (R=0.368,p=0.084); however, it was not statistically significant. Our results demonstrate that MMP-2, MMP-7, and MMP-9 expressions correlate with various morphological features of the PDAC tumor such as inflammation, necrosis, and formation of the new blood vessels.