Calotropis procera (Aiton) Dryand (Apocynaceae) as an anti-cancer agent against canine mammary tumor and osteosarcoma cells

Our goal was to evaluate phytochemical characterization and the antitumor potential of Calotropis procera. The phytochemical constitution of the crude extract (CE) revealed the presence of flavonoids, glycosides and cardenolide. The MTT assay was used to evaluate the cytotoxicity of CE, methanolic (MF) and ethyl acetate fractions (EAF) of C. procera in canine osteosarcoma cells (OST), canine mammary tumor (CMT), and canine skin fibroblasts (non-tumor cell). Doxorubicin was also used as a positive control. Results showed that CE, MF and EAF promoted a decrease in the viability of OST and CMT cells and did not alter the fibroblasts viability. C. procera also decreased the number of cells, corroborating to the decrease in proliferation and the cell cycle arrest in the G0/G1 phase. It was also evaluated the cell morphology by light and fluorescence microscopy, being demonstrated a reduction in cytoplasmic and cell rounding characteristic of programmed cell death. Moreover, flow cytometry data demonstrated that CE treatment promoted increase of caspase-3 and p53, showing that the cell death was activated in OST cells. In addition, there was a decrease in CD31, VEGF, osteopontin and TGF-β after CE treatment, suggesting that CE exerts its antitumor effect by reducing angiogenesis and tumor progression in OST cells. Moreover, CMT cells showed a reduction in PCNA after treatment with MF and CE. Analyzing the data together, C. procera, especially CE, showed an antitumor potential in both OST and CMT cells, encouraging us to continue investigating its use in cancer therapy.

Evaluation of immunohistopathological profile of tubular and solid canine mammary carcinomas

Breast cancer is the most common cancer in women, but the incidence of mammary carcinoma in female dogs is even higher than in humans. These two tumors have similarities that can be seen by its biological behavior, molecular genetic alterations, and histology. This suggest that female dogs can be an excellent model for preclinical oncological studies. And the mammary carcinoma most frequently found in this species is the tubular and solid carcinomas. The extracellular matrix (ECM) has an important role in the progression of these tumors. Because of that we proposed to evaluate the ECM components of these carcinomas through histology with specific stains such as Masson's Trichrome, Picrosirius Red and the technique of scanning electron microscopy. With that, we found the presence of collagen fibers in the tubular carcinoma and around its parenchyma. On the other hand, the solid carcinoma presented collagen fibers throughout the parenchyma and around each tumor cell. With the transmission electron microscopy, we observed the presence of mitochondrias and rough endoplasmic reticulum in both tumors. And finally, we evaluated the expression of proteins through the immunohistochemistry, in which we found a high expression of VEGF, PCNA, CK-18 and vimentin in solid carcinoma, and a positive mark in the tubular and solid carcinoma for collagen I, III and fibronectin. Thus, we demonstrated some differences in the ECM of these mammary carcinomas, allowing a better understanding of its histological characteristics, and these data may contribute to future studies about therapies focused on tumors ECM.

Characterization of the extracellular matrix in the chorioallantoic membrane of water buffalo (Bubalus bubalis) in early gestation

Placenta is formed by a parenchyma rich in extracellular matrix (ECM), and this structure guarantees the proper development of the embryo and placental functioning. Recently, studies have focused on the characterization of ECM in the placenta and foetal membranes of different species. This work aimed to analyse the composition of the ECM and to quantify the types of collagens in its composition. For this, 33 chorioallantoic membranes were used at different gestational ages, which were grouped into five groups. Subsequently, haematoxylin-eosin staining, Masson trichrome and picrosirius were performed for histological analysis. Through the technique of polarized light, it was possible to quantify the total collagen present in the membranes and finally the immunohistochemical technique was performed to verify the presence of collagens and glycoproteins. It was possible to verify that the chorioallantoic membranes have, in all the gestational periods of the initial third of gestation, the same histological structures, being the most significant difference the membrane thickening that occurs gradually during the gestation. However, we notice the appearance of binucleate cells only from group II. In addition, it was verified that a gradual increase of collagen occurs until the group IV, yet from the group V begins to occur a decrease of this protein. In addition, collagen I, collagen III, fibronectin and laminin were present in all membranes. With this, we concluded that the buffalo chorioallantoic membrane presents ECM in constant remodelling at the beginning of gestation and can be used as biomaterial in works on regenerative biology.

Abstract 1161: Interaction between doxorubicin and amniotic membrane stem cells on the canine inflammatory mammary cancer cell line IPC-366

The aim of this study was to evaluate the efficiency of doxorubicin, canine amniotic membrane stem cells (AMC) and the association between them in the triple-negative canine inflammatory mammary cancer cell line IPC-366. Experiments were carried out for 72 hours in 4 groups: IPC-366 untreated cells; cells treated with 10mg/mL of doxorubicin; coculture IPC-366 cells with 105 AMC; and cells treated with doxorubicin+AMC. MTT assays were performed for evaluating proliferation; flow cytometry to analyze hormonal and angiogenesis markers, and anti-inflammatory cytokines; and EIA techniques were used to evaluate secretion of steroid hormones (progesterone (P4); dehydroepiandrosterone (DHEA); androtenedione (A4); 17β-estradiol (E2); estrone sulphate (SO4E1)) in cell culture media. Results showed that cells treated with 10 mg/mL of doxorubicin resulted in a reduction of 71.64% on cell proliferation at 72h of treatment. A reduction in the expression of VEGF and PCNA-3 was observed by flow cyotmetry in treated cells compared to control cells. Differences on IL-10 were found within groups: treatment with doxorubicin resulted in a reduction on IL-10 expression although in AMC group expression remained similar to control group. Estrogen intracellular levels were significantly increased in doxorubicin+AMC group (4.67% vs. 27.1%). Regarding steroid hormone secretion, in AMC treated group any differences in hormone levels were found compared to control group. P4 and E2 secretion resulted in an increase in doxorubicin-treated group although in doxorubicin+AMC group these levels decreased with respect to control group. DHEA secretion was significantly decreased in treated groups compared to control group. Interestingly, A4 and SO4E1 secretion levels showed a significant increase compared to control group. Collectively, these results suggest that combination of doxorubicin and AMC caused a synergy that alters the cancer cell's secretion hormone profile by accumulation of estrogens. These findings attempt to give an approach of the combination of well-known treatments and amniotic stem cells as a canine mammary tumors therapy.

Citation Format: Jessica Borghesi, Sara Caceres, Lara C. Mario, Rafael Gonçalves Hayashi, Laura Peña, Angela Alonso-Diez, Maria J. Illera, Gema Silvan, Maria A. Miglino, Ana C. Oliveira Carreira, Phelipe Oliveira Favaron, Juan C. Illera. Interaction between doxorubicin and amniotic membrane stem cells on the canine inflammatory mammary cancer cell line IPC-366 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1161.