Three snake venoms from Bothrops genus induced apoptosis and cell cycle arrest in K562 human leukemic cell line.

Cancer is indisputably one of the leading causes of death worldwide. Snake venoms are a potential source of bioactive compounds, complex mixtures constituted mainly of proteins and peptides with several pharmacological possibilities, including the potential to inhibit tumoral cell growth. In the present study, it was evaluated the antitumor effect of crude venom of Bothrops erythromelas (BeV), Bothrops jararaca (from Southern and Southeastern- BjsV and BjsdV, respectively) and Bothrops alternatus (BaV) in in vitro Chronic myeloid leukemia (CML) cancer cell line model. After 24 h of cell exposure to 10 and 50 µg/mL, BjsV, BjsdV, and BaV exerted a decrease in cell viability in both concentrations. BeV was not cytotoxic and, therefore wasn't chosen for further mechanism of action investigation. Furthermore, morphological alterations show modification typical of apoptosis. Also, was observes a significant cell cycle arrest in the S phase by BjsdV and BaV treatment. Flow cytometry evidenced the involvement of changes in the cell membrane permeability and the mitochondrial function by BjsV and BjsdV, corroborating with the triggering of the apoptotic pathway by the venom administration. BjsV, BjsdV, and BaV also led to extensive DNA damage and were shown to modulate the gene expression of transcripts related to the cell cycle progression and suppress the expression of the BCR-ABL1 oncogene. Altogether, these findings suggest that the venoms trigger the apoptosis pathway due to mitochondrial damage and cell cycle arrest, with modulation of intracellular pathways important for CML progression. Thus, indicating the pharmacological potential of these venoms in the development of new antitumoral compounds.

True or false: what are the factors that influence COVID-19 diagnosis by RT-qPCR?

INTRODUCTION: The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease has had a catastrophic impact on the world resulting in several deaths. Since World Health Organization declared the pandemic status of the disease, several molecular diagnostic kits have been developed to help the tracking of viruses spread. AREAS COVERED: This review aims to describe and evaluate the currently reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) diagnosis kit. Several processes used in COVID-19 diagnostic procedures are detailed in further depth to demonstrate optimal practices. Therefore, we debate the main factors that influence the viral detection of SARS-COV-2 and how they can affect the diagnosis of patients. EXPERT OPINION: Here is highlighted and discussed several factors that can interfere in the RT-PCR analysis, such as the viral load of the sample, collection site, collection methodology, sample storage, transport, primer, and probe mismatch/dimerization in different brand kits. This is a pioneer study to discuss the factor that could lead to the wrong interpretation of RT-qPCR diagnosis of SARS-CoV-2. This study aimed to help the readers to understand what very likely is behind a bad result of SARS-CoV-2 detection by RT-PCR and what could be done to reach a reliable diagnosis.