Investigation of co-treatment multi-targeting approaches in breast cancer cell lines.

In 2020, breast cancer (BC) has surpassed lung cancer as the most diagnosed cancer in the world. Tumor microenvironment (TME) plays a critical role in resistance to standard therapies and tumor progression. Two key factors within the TME include adenosine, an immunosuppressive molecule, and glucose, which serves as the primary energy source for tumor cells. In this scenario, inhibiting the purinergic pathway and glucose uptake might be a promising strategy. Therefore, we sought to evaluated different treatment approaches in BC cells (Dapagliflozin, a SGLT2 inhibitor; Paclitaxel, the standard chemotherapy for BC; and ARL67156/APCP, inhibitors of CD39 and CD73, respectively). The expression of some membrane markers relevant to resistance was assessed. BC cell-lines (MCF-7 and MDA-MB-231) were co-treated and cell viability, cell cycle, and annexin/PI assays were performed. Our analysis showed promising results, where the combination of these compounds led to cell death by apoptosis/necrosis and cell cycle arrest. Dapagliflozin showed more impact on early apoptosis, whereas Paclitaxel led to late apoptosis/necrosis as the main mechanism of cell death. Inhibiting purinergic signaling also contributed to reducing cell viability together with the other drugs, suggesting it could have an influence on breast cancer survival mechanisms. Indeed, the overexpression of the NT5E gene in patients with ER+ tumors is strongly associated with reduced overall survival and progression-free interval. However, more studies are needed to fully understand the interactions and mechanism underlying these co-treatment multi-targeting approaches.

Impairment of adenosine signaling disrupts early embryo development: unveiling the underlying mechanisms.

Purinergic signaling has been implicated in many biological functions, including development. In this study, we investigate the functions of extracellular adenosine and adenosine receptors using a mouse embryonic stem cell (ESC) line and morula stages isolated from mouse embryos. Feeder-free mouse ESC was investigated in the absence and presence of the leukemia inhibitory factor (LIF), configuring undifferentiated cells and cells undergoing spontaneous differentiation. High alkaline phosphatase (ALPL) and low CD73 levels resulting in low adenosine (eADO) levels were characteristic for pluripotent cells in the presence of the LIF, while LIF deprivation resulted in augmented adenosine levels and reduced pluripotency marker expression, which indicated differentiation. Tracing ESC proliferation by BrdU labeling revealed that the inhibition of ALPL by levamisole resulted in a decrease in proliferation due to less eADO accumulation. Furthermore, caffeine and levamisole treatment, inhibiting adenosine receptor and eADO accumulation, respectively, reduced ESC migration, similar to that observed in the absence of the LIF. Pharmacological approaches of selective adenosine receptor subtype inhibition triggered specific adenosine receptor activities, thus triggering calcium or MAP kinase pathways leading to differentiation. In line with the in vitro data, mouse embryos at the morula stage were sensitive to treatments with A1 and A3 receptor antagonists, leading to the conclusion that A1 receptor and A3 receptor inhibition impairs proliferation and self-renewal and triggers inappropriate differentiation, respectively. The findings herein define the functions of eADO signaling in early development with implications for developmental disorders, in which adenosine receptors or ectonucleotidase dysfunctions are involved, and which could lead to malformations and miscarriages, due to exposure to caffeine.

Effect of temozolomide treatment on the adenine nucleotide hydrolysis in blood serum of rats with implanted gliomas

Objective: Adenine nucleotides and adenosine have many important functions in the physiological and pathological conditions. The measurement of these nucleotides in serum may be an auxiliary tool in the identification of cellular damage in many pathological conditions. The aim of this study is to examine the effect of chemotherapy treatment on nucleotide hydrolysis in the serum of rats following glioma implantation. Methods: C6 glioma cells were injected in the right striatum of 60 day-old Wistar rats, and 20 days after the induction of gliomas, blood serum samples were prepared for measurement of ATP and AMP hydrolysis. Results: The pathological analysis showed that the malignant gliomas induced by C6 injection and treated with temozolomide exhibited a reduction in malignant characteristics. The results demonstrated that the rats that underwent temozolomide treatment had a significant decrease (p<0.05) in blood serum hydrolysis of ATP and AMP when compared with the glioma group. None of the animals included in this study presented significant alterations in the activities of the serum enzymes alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. Conclusion: The decrease in the enzymatic hydrolysis of the ATP and AMP is probably related to the diminished malignant characteristics caused by temozolomide treatment on the gliomas in vivo.

Estudos farmacológicos preliminares dos extratos da Casearia sylvestris Swartz / Preliminary pharmacological studies of Casearia Sylvestris Swartz extracts

O "chá de bugre", Casearia sylvestris Swartz tem sido, popularmente, usado com várias finalidades. Mais recentemente lhe tem sido atribuído características abortivas. Essa possibilidade levou-nos a avaliar a toxicidade dos extratos brutos de suas folhas, e os efeitos no útero, sobre a motilidade espontânea e as contraçöes induzidas pela ocitocina. A dose letal média do extrato aquoso a quente é de 1,792g de resíduo, por quilo de peso, para camundongos albinos. Com a soluçäo aquosa do extrato etanólico observamos, "in vitro", na motilidade espontânea uterina de ratas, aumento da freqüência de contraçäo e do tônus basal e diminuiçäo da amplitude de contraçäo; na curva dose-reposta à ocitocina, diminuiçäo da resposta máxima e aumento da dose efetiva média. O extrato aquoso a frio produziu, na motilidade espontânea uterina, aumento de todos os parâmetros observados; na curva dose-resposta à ocitocina, também aumentou a resposta máxima, diminuindo, entretanto, sua dose efetiva média. Os resultados sugerem que os extratos de folhas de C. sylvestris säo capazes de modificar a atividiade uterina, "in vitro". Esses dados poderiam explicar o uso obortivo