Metastasis and angiogenesis in cervical cancer: key aspects of purinergic signaling in platelets and possible therapeutic targets.

Cervical cancer ranks as the fourth most common and fatal cancer among women worldwide. Studies have demonstrated a strong association between purinergic platelet signaling and tumor progression in this type of cancer. The literature shows that neoplastic cells, when in the bloodstream, secrete adenosine triphosphate (ATP) and adenosine nucleotide diphosphate (ADP) that act on their corresponding platelet P2Y and P2X receptors. The interaction of these nucleotides with their receptors results in platelet activation and degranulation, ensuing several consequences, such as vascular endothelial growth factor (VEGF), platelet-derived growth factor, matrix metalloproteinases, ADP, and ATP. These molecules play essential roles in angiogenesis and tumor metastasis in cervical cancer. Several purinergic receptors are found in endothelial cells. Their activation, especially P2Y2, by the nucleotides released by platelets can induce relaxation of the endothelial barrier and consequent extravasation of tumor cells, promoting the development of metastases. Cancer cells that enter the bloodstream during the metastatic process are also subject to high shear stress and immune surveillance. In this context, activated platelets bind to circulating tumor cells and protect them against shear stress and the host's immune system, especially against natural killer cells, facilitating their spread throughout the body. Furthermore, activation of the P2Y12 receptor present on the platelet surface promotes the release of VEGF, the main inducer of angiogenesis in cervical cancer, in addition to increasing the concentration of several other pro-angiogenic molecules. Therefore, this review will address the role of platelet purinergic signaling in tumor progression of cervical cancer and propose possible therapeutic targets.

Functional epitope core motif of the Anaplasma marginale major surface protein 1a and its incorporation onto bioelectrodes for antibody detection.

Anaplasmosis, a persistent intraerythrocytic infection of cattle by Anaplasma marginale, causes severe anemia and a higher rate of abortion, resulting in significant loss to both dairy and beef industries. Clinical diagnosis is based on symptoms and confirmatory laboratory tests are required. Currently, all the diagnostic assays have been developed with whole antigens with indirect ELISA based on multiple epitopes. In a pioneer investigation we demonstrated the use of critical motifs of an epitope as biomarkers for immunosensor applications. Mimotopes of the MSP1a protein functional epitope were obtained through Phage Display after three cycles of selection of a 12-mer random peptide library against the neutralizing monoclonal antibody 15D2. Thirty-nine clones were randomly selected, sequenced, translated and aligned with the native sequence. The consensus sequence SxSSQSEASTSSQLGA was obtained, which is located in C-terminal end of the 28-aa repetitive motif of the MSP1a protein, but the alignment and sequences' variation among mimotopes allowed us to map the critical motif STSSxL within the consensus sequence. Based on these results, two peptides were chemically synthesized: one based on the critical motif (STSSQL, Am1) and the other based on the consensus sequence aligned with the native epitope (SEASTSSQLGA, Am2). Sera from 24 infected and 52 healthy animals were tested by ELISA for reactivity against Am1 and Am2, which presented sensitivities of 96% and 100%, respectively. The Am1 peptide was incorporated onto a biolectrode (graphite modified with poly-3-hydroxyphenylacetic acid) and direct serum detection was demonstrated by impedance, differential pulse voltammetry, and atomic force microscopy. The electrochemical sensor system proved to be highly effective in discriminating sera from positive and negative animals. These immunosensors were highly sensitive and selective for positive IgG, contaminants did not affect measurements, and were based on a simple, fast and reproducible electrochemical system.

Gene expression profile in the peripheral blood of patients with prostate cancer and benign prostatic hyperplasia.

BACKGROUND: Prostate cancer consists of multifactorial and multifocal events, generating differential gene expression in tumor cells. METHODS: The molecular profile of 14 gene expression was analyzed through cDNA array in blood samples of patients with prostate cancer (PCa) and benign prostatic hyperplasia (BPH). RESULTS: Messenger RNA from patient's blood showed significant differences between PCa and BPH groups only for the NOS3 gene, with an occurrence chance for PCa5.8-fold higher than BPH disease. CONCLUSION: The NOS3 gene expression in the patient's blood may be used as a putative biomarker for prostate cancer.

The endothelial nitric oxide synthase Glu-298-Asp polymorphism and its mRNA expression in the peripheral blood of patients with prostate cancer and benign prostatic hyperplasia.

BACKGROUND: The endothelial nitric oxide synthase (ecNOS) has an important role in vascular development and in the carcinogenesis process of prostate cancer (PCa). The nitric oxide (NO) production may promote cancer progression by providing a selective growth advantage to tumor cells, by angiogenic stimulus and by direct DNA damage. METHODS: The present study aimed at evaluating the ecNOS Glu-298-Asp polymorphism by the PCR-RFLP technique, associating genotypes with gene expression levels and the tumor biomarker, Prostate Cancer Antigen (DD3), through semi-quantitative RT-PCR. Pre-surgical peripheral blood samples from 160 patients were analyzed: 84 PCa, 11 prostate intraepithelial neoplasia (PIN) and 65 benign prostatic hyperplasia (BPH). RESULTS: The GG and GT Glu-298-Asp genotypes were associated with positive DD3 expression in the peripheral blood, presenting a 3.32-fold higher risk of PCa occurrence. There was no association between genotypes and ecNOS mRNA expression levels; however, the presence of the G allele is closely related to the hematogenous dissemination event of tumoral cells, as evidenced by the DD3 positivity. The higher G allele frequency among pT3 and pT4 staged PCa patients suggests that this would be associated with advanced phenotypes of the disease and may also be contributing to higher NO levels, causing cancer progression. CONCLUSIONS: The G allele may have a secondary influence on the prostate cancer predisposition, but an essential role on the event of tumor cells hematogenous dissemination, probably due to the angiogenic stimulus.

Anti-herpes simplex virus activity of sulfated galactans from the red seaweeds Gymnogongrus griffithsiae and Cryptonemia crenulata.

This study presents the chemical composition and antiviral activity against herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) of sulfated galactan crude extracts and main fractions obtained from two red seaweeds collected in Brazil, Gymnogongrus griffithsiae and Cryptonemia crenulata. Most of the eighteen tested products, including homogeneous kappa/iota/nu carrageenan and DL-galactan hybrid, exhibited antiherpetic activity with inhibitory concentration 50% (IC50) values in the range 0.5-5.6 microg/ml, as determined in a virus plaque reduction assay in Vero cells. The galactans lacked cytotoxic effects and showed a broad spectrum of antiviral activity against HSV-1 and HSV-2. No direct virus inactivation was observed after virion treatment with the galactans. The mode of action of these compounds could be mainly ascribed to an inhibitory effect on virus adsorption. Most importantly, a significant protection against a murine vaginal infection with HSV-2 was afforded by topical treatment with the sulfated galactans.