Applications of engineered exosomes in drugging noncoding RNAs for cancer therapy.

Noncoding RNAs (ncRNAs) are engaged in key cell biological and pathological events, and their expression alteration is connected to cancer progression both directly and indirectly. A huge number of studies have mentioned the significant role of ncRNAs in cancer prevention and therapy that make them an interesting subject for cancer therapy. However, there are several limitations, including delivery, uptake, and short half-life, in the application of ncRNAs in cancer treatment. Exosomes are introduced as promising options for the delivery of ncRNAs to the target cells. In this review, we will briefly discuss the application and barriers of ncRNAs. After that we will focus on exosome-based ncRNAs delivery and their advantages as well as the latest achievements in drugging ncRNAs with exosomes.

Melatonin Reverses the Warburg-Type Metabolism and Reduces Mitochondrial Membrane Potential of Ovarian Cancer Cells Independent of MT1 Receptor Activation.

Ovarian cancer (OC) is the most lethal gynecologic malignancy, and melatonin has shown various antitumor properties. Herein, we investigated the influence of melatonin therapy on energy metabolism and mitochondrial integrity in SKOV-3 cells and tested whether its effects depended on MT1 receptor activation. SKOV-3 cells were exposed to different melatonin concentrations, and experimental groups were divided as to the presence of MT1 receptors (melatonin groups) or receptor absence by RNAi silencing (siRNA MT1+melatonin). Intracellular melatonin levels increased after treatment with melatonin independent of the MT1. The mitochondrial membrane potential of SKOV-3 cells decreased in the group treated with the highest melatonin concentration. Melatonin reduced cellular glucose consumption, while MT1 knockdown increased its consumption. Interconversion of lactate to pyruvate increased after treatment with melatonin and was remarkable in siRNA MT1 groups. Moreover, lactate dehydrogenase activity decreased with melatonin and increased after MT1 silencing at all concentrations. The UCSC XenaBrowser tool showed a positive correlation between the human ASMTL gene and the ATP synthase genes, succinate dehydrogenase gene (SDHD), and pyruvate dehydrogenase genes (PDHA and PDHB). We conclude that melatonin changes the glycolytic phenotype and mitochondrial integrity of SKOV-3 cells independent of the MT1 receptor, thus decreasing the survival advantage of OC cells.

Evaluation of doxorubicin in three-dimensional culture of breast cancer cells and the response in PI3K/AKT/PTEN signaling pathways: a pilot study.

Breast cancer (BC) has a high mortality rate, which is attributed to the absence of effective treatment markers. Doxorubicin (DOX) was evaluated by molecular docking in vitro in cultured BC spheroids and its association with genes involved in the PI3K/AKT/PTEN signaling pathway. Spheroids were obtained from a primary BC. The selected compound was used for molecular docking experiments. Spheroids were treated with DOX for 1 (D1) and 9 (D9) days. qPCR was used to evaluate PIK3CA, HIF-1α, VEGF-A, PTEN expression. Treatment with DOX (1 µM) significantly increased the number of spheroids (D1), whereas exposure to chemotherapy at 2 µM on D9 was more effective. DOX treatment resulted in significantly higher expression of VEGF-A, HIF-1α and PIK3CA by D1 and HIF-1α and PTEN were upregulated by D9. Compared to treatment on D1 with D9 (1 µM) had significantly higher PTEN and lower PIK3CA gene expression. The genes HIF-1α and PTEN were more expressed with 2 µM of DOX while VEGF-A was downregulated. D1 vs. D9 exhibited reduced VEGF-A, HIF-1α, and PIK3CA expression and upregulation of PTEN expression. DOX effects at the molecular mechanisms can be involved the modulation of genes related to angiogenesis cell proliferation and tumor growth in BC tissue spheroids.

Melatonin: A mitochondrial resident with a diverse skill set.

Melatonin is an ancient molecule that originated in bacteria. When these prokaryotes were phagocytized by early eukaryotes, they eventually developed into mitochondria and chloroplasts. These new organelles retained the melatonin synthetic capacity of their forerunners such that all present-day animal and plant cells may produce melatonin in their mitochondria and chloroplasts. Melatonin concentrations are higher in mitochondria than in other subcellular compartments. Isolated mouse oocyte mitochondria form melatonin when they are incubated with serotonin, a necessary precursor. Oocyte mitochondria subsequently give rise to these organelles in all adult vertebrate cells where they continue to synthesize melatonin. The enzymes that convert serotonin to melatonin, i.e., arylalkylamine-N-acetyltransferase (AANAT) and acetylserotonin-O-methyltransferase, have been identified in brain mitochondria which, when incubated with serotonin, also form melatonin. Melatonin is a potent antioxidant and anti-cancer agent and is optimally positioned in mitochondria to aid in the maintenance of oxidative homeostasis and to reduce cancer cell transformation. Melatonin stimulates the transfer of mitochondria from healthy cells to damaged cells via tunneling nanotubes. Melatonin also regulates the major NAD+-dependent deacetylase, sirtuin 3, in the mitochondria. Disruptions of mitochondrial melatonin synthesis may contribute to a number of mitochondria-related diseases, as discussed in this review.

The proteomic landscape of ovarian cancer cells in response to melatonin.

Ovarian cancer (OC) is the most lethal gynecological malignancy with a highly negative prognosis. Melatonin is an indoleamine secreted by the pineal gland during darkness and has shown antitumor activity in both in vitro and in vivo experiments. Herein, we investigated the influence of melatonin on the proteome of human ovarian carcinoma cells (SKOV-3 cell line) using the Ultimate 3000 LC Liquid NanoChromatography equipment coupled to a Q-Exactive mass spectrometry. After 48 h of treatment, melatonin induced a significant cytotoxicity especially with the highest melatonin concentration. The proteomic profile revealed 639 proteins in the control group, and 98, 110, and 128 proteins were altered by melatonin at the doses of 0.8, 1.6, and 2.4 mM, respectively. Proteins associated with the immune system and tricarboxylic acid cycle were increased in the three melatonin-exposed groups of cells. Specifically, the dose of 2.4 mM led to a reduction in molecules associated with protein synthesis, especially those of the ribosomal protein family. We also identified 28 potential genes shared between normal ovarian tissue and OC in all experimental groups, and melatonin was predicted to alter genes encoding ribosomal proteins. Notably, the set of proteins changed by melatonin was linked to a better prognosis for OC patients. We conclude that melatonin significantly alters the proteome of SKOV-3 cells by changing proteins involved with the immune response and mitochondrial metabolism. The concentration of 2.4 mM of melatonin promoted the largest number of protein changes. The evidence suggests that melatonin may be an effective therapeutic strategy against OC.

Treatment of Triple Negative Cell Lines with Olaparib to Block DNA Repair.

BACKGROUND: The most aggressive breast cancer is the triple negative histological type, and the gold standard for its treatment is platinum salts, such as carboplatin. Due to high recurrence, there is a need to test new drugs, such as PARP inhibitors (PARPi), that induce lethality in cells with DNA damage. Olaparib is a PARPi, already used in some tumors but not tested in canine species. Thus, the aim of this study was to demonstrate the efficacy of olaparib in inhibiting DNA repair and control disease progression by decreasing the migration capacity of mammary tumor cells. METHODS: The cell lines CF41.Mg and MDA-MB-468 were cultured and MTT was performed to define the best dose of carboplatin. Next, the cells were treated with 10 µM carboplatin, olaparib, and with a combination of both for 24 hours. PARP-1 protein and gene expression were evaluated by immunofluorescence, western blotting, and qRT-PCR, respectively. The analysis of cell migration was performed in transwell chambers. RESULTS: For CF41.Mg and MDA-MB-468 cell lines, there was a decrease in PARP-1 protein and gene expression after treatment with carboplatin, olaparib, and both in combination compared to the group without treatment (control) (p<0.05). Moreover, in both lines, a reduction in invasion rate was observed after treatment with carboplatin, olaparib and when combined, compared to the control group (p<0.05). CONCLUSION: Our data suggest that carboplatin and olaparib were able to block DNA repair and control the cancer invasion, especially when used in combination. The results with olaparib in the canine line are unpublished. The olaparib should be a possible agent against human breast cancer and canine mammary tumors.

Immunohistochemical Evaluation of PARP and Caspase-3 as Prognostic Markers in Prostate Carcinomas.

Prostate cancer is the second most common neoplasm among men, with a high mortality rate in advanced stages. Poly (ADP-ribose) polymerase (PARP) plays an important role in repair to DNA damage, being associated with resistance to tumor cell death. Conversely, Caspase-3 is a crucial mediator of programmed cell death, being highly expressed in apoptotic cells. The aim of the present study was to characterize the expression of PARP and Caspase-3 by immunohistochemistry in patients with advanced prostate cancer. PARP and Caspase-3 were independently correlated to patients' evolution, in accordance with the classification of prognostic groups. The increase in PARP expression was positively correlated with tumor patients with poor prognosis (P < 0.0001). In contrast, a decrease in Caspase-3 expression was identified in patients with poor prognosis, when compared with prostate cancer patients with good prognosis (P = 0.0007). Numerically, 92.3% of patients previously classified with poor prognosis showed higher PARP expression, while 93.75% of patients previously classified with good prognosis showed higher levels of Caspase-3. We conclude that PARP and Caspase-3 are potential prognostic markers for prostate cancer patients with different prognosis.

Oncolytic effect of Newcastle disease virus is attributed to interferon regulation in canine mammary cancer cell lines.

Canine mammary carcinoma (CMC) is one of the major health threats in dogs. The oncolytic virotherapy is a promising strategy to treat canine as well as human cancer patients with non-pathogenic replicating viruses. Here, we evaluated the antitumor activity of one lentogenic, non-lytic Newcastle disease virus (NDV) LaSota strain expressing GFP (NDV-GFP) on five different CMCs and one non-tumorigenic cell line, regarding cell viability, cell death, selectivity index, morphology, global and target gene expression analysis. As evidenced by the selectivity index, all CMC cell lines were more susceptible to NDV-GFP in comparison with the non-tumorigenic cells (~3.1× to ~78.7×). In addition, the oncolytic effect of NDV-GFP was more evident in more malignant CMC cells. Also, we observed an inverse association of the IFN pathway expression and the susceptibility to NDV. The downregulated genes in NDV-GFP-sensitive cells were functionally enriched for antiviral mechanisms by interferon and immune system pathways, demonstrating that these mechanisms are the most prominent for oncolysis by NDV. To our knowledge, this is the first description of oncolysis by an NDV strain in canine mammary cancer cells. We also demonstrated specific molecular pathways related to NDV susceptibility in these cancer cells, opening the possibility to use NDV as a therapeutic-targeted option for more malignant CMCs. Therefore, these results urge for more studies using oncolytic NDVs, especially considering genetic editing to improve efficacy in dogs.

Prognostic phenotypic classification for canine mammary tumors.

Mammary neoplasms are a heterogeneous form of disease, and in order to determine its course and biological features with more accuracy, investigations based on tumor phenotypes are required. The aim of the present study was to propose and validate a phenotypic classification for canine mammary tumors and to assess any association between clinicopathological characteristics, survival and prognosis. For the immunohistochemistry analysis, the primary antibodies against estrogen receptor-α, progesterone receptor, human epidermal growth factor receptor 2 (HER-2)/neu and E-cadherin were used. A total of 110 canine mammary tumors were investigated; 42 tumors were classified as luminal A, 41 as luminal B, 17 as triple-negative and 10 as HER-2-positive. The luminal A and B phenotypes were associated with improved prognosis, whereas HER-2positive and triple-negative tumors were more aggressive, and exhibited a significant association with the occurrence of metastasis, a worse Tumor-Node-Metastasis classification and shorter survival time (P<0.05). In addition, there were different levels of E-cadherin expression intensity observed among the four tumor profiles investigated. Luminal A and B phenotypes presented an upregulation of E-cadherin compared with the HER-2 positive and triple-negative phenotypes (P<0.05). From the results of the present study, the proposed immunohistochemical panel and phenotypic classification techniques could be useful diagnostic tools with a good technical applicability in veterinary oncology. The analysis of E-cadherin expression in the panel of tumor markers allowed a more accurate classification for determining the biological features of the mammary tumor.

Antiproliferative activity and p53 upregulation effects of chalcones on human breast cancer cells.

Chalcones are valuable structures for drug discovery due to their broad bioactivity spectrum. In this study, we evaluated 20 synthetic chalcones against estrogen-receptor-positive breast cancer cells (MCF-7 line) and triple-negative breast cancer (TNBC) cells (MDA-MB-231 line). Antiproliferative screening by MTT assay resulted in two most active compounds: 2-fluoro-4'-aminochalcone (11) and 3-pyridyl-4'-aminochalcone (17). Their IC50 values ranged from 13.2 to 34.7 µM against both cell lines. Selected chalcones are weak basic compounds and maintained their antiproliferative activity under acidosis conditions (pH 6.7), indicating their resistance to ion-trapping effect. The mode of breast cancer cells death was investigated and chalcones 11 and 17 were able to induce apoptosis rather than necrosis in both lines. Antiproliferative target investigations with MCF-7 cells suggested 11 and 17 upregulated p53 protein expression and did not affect Sp1 protein expression. Future studies on chalcones 11 and 17 can define their in vivo therapeutic potential.

Melatonin regulates tumor aggressiveness under acidosis condition in breast cancer cell lines.

Breast cancer progression is composed of multiple steps that are influenced by tumor cell adaptations to survive under acidic conditions in the tumor microenvironment. Regulation of this cell survival behavior is a promising strategy to avoid cancer development. Melatonin is a natural hormone produced and secreted by the pineal gland capable of modulating different biological pathways in cancer. Although the anti-cancer effects of melatonin are currently widespread, its role in the acid tumor microenvironment remains poorly understood. The aim of the present study was to investigate the effect of low pH (6.7) on human breast cancer cell lines MCF-7 and MDA-MB-231, and the effectiveness of melatonin in acute acidosis survival mechanisms. Cell viability was measured by a MTT assay and the protein expression of glucose transporter (GLUT)-1, Ki-67 and caspase-3 was evaluated by immunocytochemical (ICC) analysis following low pH media and melatonin treatment. In both cell lines the viability was decreased after melatonin treatment (1 mM) under acidosis conditions for 24 h. ICC analysis showed a significant increase in GLUT-1 and Ki-67 expression at pH 6.7, and a decrease after treatment with melatonin for 12 and 24 h. The low pH media decreased the expression of caspase-3, which was increased after melatonin treatment for 12 and 24 h. Overall, the results of the present study revealed melatonin treatment increases apoptosis, as indicated by changes in caspase-3, and decreases proliferation, indicated by changes to Ki-67, and GLUT-1 protein expression under acute acidosis conditions in breast cancer cell lines.

Evaluation of melatonin and AFMK levels in women with breast cancer.

PURPOSE: Changes in the circadian rhythm may contribute to the development of cancer and are correlated with the high risk of breast cancer (BC) in night workers. Melatonin is a hormone synthesized by the pineal gland at night in the absence of light. Levels of melatonin and the metabolite of oxidative metabolism AFMK (acetyl-N-formyl-5-methoxykynurenamine), are suggested as potential biomarkers of BC risk. The aims of this study were to evaluate levels of melatonin and AFMK in women recently diagnosed with BC, women under adjuvant chemotherapy, and night-shift nurses, and compare them with healthy women to evaluate the relation of these compounds with BC risk. METHODS: Blood samples were collected from 47 women with BC, 9 healthy women, 10 healthy night shift nurses, and 6 patients under adjuvant chemotherapy. Compound levels were measured by mass spectrometry. RESULTS AND CONCLUSIONS: Our results showed that women with BC had lower levels of melatonin compared to control group women, and even lower in night-shift nurses and in patients under adjuvant chemotherapy. There was no significant difference of AFMK levels between the groups. In addition to this, high levels of melatonin and AFMK were related to patients with metastasis, and high levels of AFMK were related to the presence of lymph node-positive, tumor > 20 mm and patients who sleep with light at night. Our results showed a reduction of melatonin levels in BC patients, suggesting a relation with the disease, and in addition, point to the importance of melatonin supplementation in women that work at night to reduce the BC risk.

Efficacy of melatonin, IL-25 and siIL-17B in tumorigenesis-associated properties of breast cancer cell lines.

Mammary tumorigenesis can be modulated by melatonin, which has oncostatic action mediated by multiple mechanisms, including the inhibition of the activity of transcription factors such as NF-κB and modulation of interleukins (ILs) expression. IL-25 is an active cytokine that induces apoptosis in tumor cells due to differential expression of its receptor (IL-17RB). IL-17B competes with IL-25 for binding to IL-17RB in tumor cells, promoting tumorigenesis. This study purpose is to address the possibility of engaging IL-25/IL-17RB signaling to enhance the effect of melatonin on breast cancer cells. Breast cancer cell lines were cultured monolayers and 3D structures and treated with melatonin, IL-25, siIL-17B, each alone or in combination. Cell viability, gene and protein expression of caspase-3, cleaved caspase-3 and VEGF-A were performed by qPCR and immunofluorescence. In addition, an apoptosis membrane array was performed in metastatic cells. Treatments with melatonin and IL-25 significantly reduced tumor cells viability at 1mM and 1ng/mL, respectively, but did not alter cell viability of a non-tumorigenic epithelial cell line (MCF-10A). All treatments, alone and combined, significantly increased cleaved caspase-3 in tumor cells grown as monolayers and 3D structures (p<0.05). Semi-quantitative analysis of apoptosis pathway proteins showed an increase of CYTO-C, DR6, IGFBP-3, IGFBP-5, IGFPB-6, IGF-1, IGF-1R, Livin, P21, P53, TNFRII, XIAP and hTRA proteins and reduction of caspase-3 (p<0.05) after melatonin treatment. All treatments reduced VEGF-A protein expression in tumor cells (p<0.05). Our results suggest therapeutic potential, with oncostatic effectiveness, pro-apoptotic and anti-angiogenic properties for melatonin and IL-25-driven signaling in breast cancer cells.

Inhibition of Epithelial-Mesenchymal Transition and Metastasis by Combined TGFbeta Knockdown and Metformin Treatment in a Canine Mammary Cancer Xenograft Model.

Epithelial mesenchymal transition (EMT) is a process by which epithelial cells acquire mesenchymal properties, generating metastases. Transforming growth factor beta (TGF-ß) is associated with this malignancy by having the ability to induce EMT. Metformin, has been shown to inhibit EMT in breast cancer cells. Based on this evidence we hypothesize that treatment with metformin and the silencing of TGF-ß, inhibits the EMT in cancer cells. Canine metastatic mammary tumor cell line CF41 was stably transduced with a shRNA-lentivirus, reducing expression level of TGF-ß1. This was combined with metformin treatment, to look at effects on cell migration and the expression of EMT markers. For in vivo study, unmodified or TGF-ß1sh cells were injected in the inguinal region of nude athymic female mice followed by metformin treatment. The mice's lungs were collected and metastatic nodules were subsequently assessed for EMT markers expression. The migration rate was lower in TGF-ß1sh cells and when combined with metformin treatment. Metformin treatment reduced N-cadherin and increased E-cadherin expression in both CF41 and TGF-ß1sh cells. Was demonstrated that metformin treatment reduced the number of lung metastases in animals bearing TGF-ß1sh tumors. This paralleled a decreased N-cadherin and vimentin expression, and increased E-cadherin and claudin-7 expression in lung metastases. This study confirms the benefits of TGF-ß1 silencing in addition to metformin as potential therapeutic agents for breast cancer patients, by blocking EMT process. To the best of our knowledge, we are the first to report metformin treatment in cells with TGF-ß1 silencing and their effect on EMT.

Evaluation of Melatonin Effect on Human Breast Cancer Stem Cells Using a Threedimensional Growth Method of Mammospheres.

BACKGROUND: The high rates of women&#039;s death from breast cancer occur due to acquired resistance by patients to certain treatments, enabling the recurrence and/or tumor growth, invasion and metastasis. It has been demonstrated that the presence of cancer stem cells in human tumors, as responsible for recurrence and resistance to therapy. Studies have identified OCT4 as responsible for self-renewal and maintenance of pluripotency of stem cells. Thus, it is interesting to study potential drugs that target this specific population in breast cancer. Melatonin, appears to have oncostatic effects on cancer cells, however, little is known about its therapeutic effect on cancer stem cells. OBJECTIVE: Evaluate the viability and the expression of OCT4 in breast cancer stem cells, MCF-7 and MDA-MB- 231, after melatonin treatment. METHOD: The cells were grown in a 3-dimensional model of mammospheres, representing the breast cancer stem cell population and treated or not with melatonin. The cell viability of mammospheres were evaluated by MTT assay and the OCT4 expression, a cancer stem cells marker, was verified by immunocitochemistry. RESULTS: Our results demonstrated that the melatonin treatment decreased the cell viability of MCF-7 and MDAMB- 231 mammospheres. Furthermore, it was observed that in both cell lines, the expression of OCT4 was decreased in melatonin-treated cells compared to the control group. CONCLUSIONS: This fact suggests that melatonin is effective against breast cancer stem cells inhibiting the cell viability via OCT 4. Based on that, we believe that melatonin has a high potential to be used as an alternative treatment for breast cancer.

Differential Expression of ADAM23, CDKN2A (P16), MMP14 and VIM Associated with Giant Cell Tumor of Bone.

Though benign, giant cell tumor of bone (GCTB) can become aggressive and can exhibit a high mitotic rate, necrosis and rarely vascular invasion and metastasis. GCTB has unique histologic characteristics, a high rate of multinucleated cells, a variable and unpredictable growth potential and uncertain biological behavior. In this study, we sought to identify genes differentially expressed in GCTB, thus building a molecular profile of this tumor. We performed quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry and analyses of methylation to identify genes that are putatively associated with GCTB. The expression of the ADAM23 and CDKN2A genes was decreased in GCTB samples compared to normal bone tissue, measured by qPCR. Additionally, a high hypermethylation frequency of the promoter regions of ADAM23 and CDKN2A in GCTB was observed. The expression of the MAP2K3, MMP14, TIMP2 and VIM genes was significantly higher in GCTB than in normal bone tissue, a fact that was confirmed by qPCR and immunohistochemistry. The set of genes identified here furthers our understanding of the molecular basis of GCTB.

Evaluation of melatonin treatment in primary culture of canine mammary tumors.

Mammary neoplasias are the most common tumors observed in female dogs. Identification of these tumors is valuable in order to identify beneficial therapeutic agents as alternative treatments for this tumor type. Oral administration of melatonin appears to exert an oncostatic effect on mammary neoplasia and may have a possible mechanism of action through its interaction with estrogen receptors on epithelial cells. Hence, we analyzed the potential therapeutic value of melatonin in tumors that are estrogen-dependent or -independent, and established a relationship of its action with the expression of the melatonin receptors MT1 and MT2. Furthermore, we analyzed the rate of cell proliferation and apoptosis after treatment with melatonin. Cell cultures were performed using 10 canine mammary tumor fragments and were divided into estrogen receptor (ER)-positive and ER-negative tumors. The results showed that both ER-positive and ER-negative tumors had decreased cell viability and proliferation after treatment with melatonin (p<0.05), although treatment was more effective in the ER-positive tumors. Analysis of the relative expression of the MT1 and MT2 genes by quantitative PCR was performed and the data were compared with the expression of ER in 24 canine mammary tumors and the cellular response to melatonin in 10 samples. MT1 was overexpressed in ER-positive tumors (p<0.05), whereas MT2 was not expressed. Furthermore, melatonin treatment in ER-positive tumors showed an efficient oncostatic effect by inhibiting cell viability and proliferation and inducing apoptosis. These results suggest that melatonin decreased neoplastic mammary cell proliferation and viability and induced apoptosis, with greater efficacy in ER-positive tumors that have a high expression of melatonin receptor MT1. This is a strong evidence for the use of melatonin as a therapeutic agent for estrogen-dependent canine mammary tumors.

Immunoexpression of ROCK-1 and MMP-9 as prognostic markers in breast cancer.

Breast cancer is the most common tumor in women and it has high mortality mainly due to the occurrence of tumor metastasis. Both the processes of cell migration and anchorage to the substrate are essential for the development of metastasis. These processes occur by rearrangements of the actin cytoskeleton, regulated by Rho-associated protein kinase 1 (ROCK-1). The degradation of the extracellular matrix, influenced by metalloproteinase 9 (MMP-9) also exerts greater cell invasiveness. The present study evaluated the ROCK-1 and MMP-9 proteins using an immunohistochemical method through the selection of invasive ductal breast carcinoma. The protein expression was correlated to clinicopathological parameters and overall survival of the patients. High expression of the ROCK-1 protein was correlated statistically to the status of lymph nodes (p=0.007) and showed variable expression in different clinical stages of the tumor. MMP-9 showed a strong immunostaining in patients with metastasis that had died, whereas there was no marker in normal breast tissues. In addition, 46.6% of patients classified as poor prognosis showed high expression of ROCK-1 and MMP-9 protein and another 40.0% just showed high expression of MMP-9. Thus, the differential expression of ROCK-1 and MMP-9 proteins suggests their potential use as prognostic markers in breast cancer.

Effect of melatonin on tumor growth and angiogenesis in xenograft model of breast cancer.

As neovascularization is essential for tumor growth and metastasis, controlling angiogenesis is a promising tactic in limiting cancer progression. Melatonin has been studied for their inhibitory properties on angiogenesis in cancer. We performed an in vivo study to evaluate the effects of melatonin treatment on angiogenesis in breast cancer. Cell viability was measured by MTT assay after melatonin treatment in triple-negative breast cancer cells (MDA-MB-231). After, cells were implanted in athymic nude mice and treated with melatonin or vehicle daily, administered intraperitoneally 1 hour before turning the room light off. Volume of the tumors was measured weekly with a digital caliper and at the end of treatments animals underwent single photon emission computed tomography (SPECT) with Technetium-99m tagged vascular endothelial growth factor (VEGF) C to detect in vivo angiogenesis. In addition, expression of pro-angiogenic/growth factors in the tumor extracts was evaluated by membrane antibody array and collected tumor tissues were analyzed with histochemical staining. Melatonin in vitro treatment (1 mM) decreased cell viability (p<0.05). The breast cancer xenografts nude mice treated with melatonin showed reduced tumor size and cell proliferation (Ki-67) compared to control animals after 21 days of treatment (p<0.05). Expression of VEGF receptor 2 decreased significantly in the treated animals compared to that of control when determined by immunohistochemistry (p<0.05) but the changes were not significant on SPECT (p>0.05) images. In addition, there was a decrease of micro-vessel density (Von Willebrand Factor) in melatonin treated mice (p<0.05). However, semiquantitative densitometry analysis of membrane array indicated increased expression of epidermal growth factor receptor and insulin-like growth factor 1 in treated tumors compared to vehicle treated tumors (p<0.05). In conclusion, melatonin treatment showed effectiveness in reducing tumor growth and cell proliferation, as well as in the inhibition of angiogenesis.

Pollution-induced metabolic responses in hypoxia-tolerant freshwater turtles.

The physiological control to support the absence of O2 for long periods of diving, and oxidative damage impact caused by the whole process of hypoxia/reperfusion in freshwater turtles is well known. However, effects of contaminants may act as co-varying stressors and cause biological damage, disrupting the hypoxia/reperfusion oxidative damage control. In order to investigate the action of environmental stressors present in domestic or industrial wastewater effluent, we performed a biochemical analysis of biotransformation enzymes, oxidative stress, as well as neuromuscular, physiological and morphological parameters in Phrynops geoffroanus, an hypoxic-tolerant freshwater turtle endemic of South America, using animals sampled in urban area, contaminated by sewage and industrial effluents and animals sampled in control area. Here we demonstrate the physiological and biochemical impact caused by pollution, and the effect that these changes cause in antioxidant activity. Animals from the urban area exhibited higher EROD (ethoxyresorufin-O-deethylase, CYP1A1), GST (glutathione S-transferase), G6PDH (glucose-6-phosphate deshydrogenase), AChE (acetilcholinesterase) activities and also TEAC (trolox-equivalent antioxidant capacity) and TBARS (thiobarbituric acid reactive substances) values. We examined whether two morphometric indices (K - condition factor and HIS - hepatosomatic index) which help in assessing the general condition and possible liver disease, respectively, were modified. The K of the urban animals was significantly decreased compared to the control animals, but the HIS value was increased in animals from the urban area, supporting the idea of an impact in physiology and life quality in the urban freshwater turtles. We propose that this freshwater turtle specie have the ability to enhance its antioxidants defenses in order to protect from tissue damage caused by hypoxia and reperfusion, but also that caused by environmental contamination and that the oxidative damage control in hypoxic conditions has resulted in an adaptive condition in hypoxic-tolerant freshwater turtle species, in order to better tolerate the release of contaminated effluents resulting from human activity.