Targeting notch signaling pathway in breast cancer stem cells through drug repurposing approach.

Breast cancer is recognized globally as one of the leading causes of malignant morbidity. It is a heterogeneous disease that accounts for 30 percent of all women diagnosed with cancer. To bring an anti-cancer drug from the bench to the bedside is an expensive and time-consuming process. The drug repurposing approach targets new enemies (new diseases) with old weapons (known drugs). The present study identified an FDA-approved drug targeting the γ-secretase complex involved in the Notch signaling pathway in breast cancer stem cells (BCSCs). A literature survey and in-silico study identified Venetoclax as a γ-secretase inhibitor (GSI) from 1615 FDA-approved drug compounds. In-silico docking potential of Venetoclax was better than the standard γ-secretase inhibitor RO4929097. Also, the molecular dynamics simulations of 200 ns confirmed the stability of the Venetoclax-γ-secretase complex. These findings suggest that the use of Venetoclax represents a potential γ-secretase inhibitor in breast cancer stem cells. Eventually, the in vitro and clinical evaluation will be needed to confirm the potential chemopreventive and treatment effects of Venetoclax against breast cancer and breast cancer stem cells. Venetoclax appeared as the most promising drug of the 1615 FDA-approved drugs. Our in-silico findings suggest that Venetoclax may act as a γ-secretase inhibitor against the Notch signaling pathway in breast cancer stem cells.

Lumacaftor as a potential repurposed drug in targeting breast cancer stem cells: insights from in silico study.

CONTEXT: Breast cancer stem cells (BCSCs) are a small subset of cells within breast tumors with characteristics similar to normal stem cells. Despite advancements in chemotherapy and targeted therapy for breast cancer, the prognosis for breast cancer patients has remained poor due to drug resistance, reoccurrence, and metastasis. Growing evidence suggests that deregulation of the self-renewal pathways, like the Wnt signaling pathway mediated by ß-catenin, plays a crucial role in the survival of breast cancer stem cells. Targeting the Wnt signaling pathway in breast cancer stem cells offers a promising avenue for developing effective therapeutic strategies targeting these cells, potentially leading to improved patient outcomes and reduced tumor recurrence. METHODS: For this purpose, we have screened a 1615 FDA-approved drug library against our target protein, ß-catenin, which is involved in the Wnt signaling pathway using molecular docking analysis, molecular dynamics (MD) simulations, and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations. RESULTS: Molecular docking studies showed that the Lumacaftor- ß-catenin complex had the lowest docking score of - 8.7 kcal/mol towards ß-catenin protein than the reference inhibitor. Molecular dynamic simulations and MM/PBSA calculations were also performed for the Lumacaftor-ß-catenin complex to establish the stability of the interactions involved. Considering its promising attributes and encouraging results, Lumacaftor holds significant potential as a novel therapeutic option to target BCSCs. This study opens avenues for further investigation and may pave the way for developing therapeutic potential in breast cancer treatment. Further confirmation is warranted through in vitro and clinical studies to validate the findings of this study.

Natural compounds as a potential modifier of stem cells renewal: Comparative analysis.

Cancer stem cells (CSCs) are indispensable for development, progression, drug resistance, and tumor metastasis. Current cancer-directed interventions target targeting rapidly dividing cancer cells and slow dividing CSCs, which are the root cause of cancer origin and recurrence. The most promising targets include several self-renewal pathways involved in the maintenance and renewal of CSCs, such as the Wnt/ß-Catenin, Sonic Hedgehog, Notch, Hippo, Autophagy, and Ferroptosis. In view of safety, natural compounds are coming to the front line of treatment modalities for modifying various signaling pathways simultaneously involved in maintaining CSCs. Therefore, targeting CSCs with natural compounds is a promising approach to treating various types of cancers. In view of this, here we provide a comprehensive update on the current status of natural compounds that effectively tune key self-renewal pathways of CSCs. In addition, we highlighted surface expression markers in several types of cancer. We also emphasize how natural compounds target these self-renewal pathways to reduce therapy resistance and cancer recurrence properties of CSCs, hence providing valuable cancer therapeutic strategies. The inclusion of nutraceuticals is believed to enhance the therapeutic efficacy of current cancer-directed interventions significantly.

Rifampicin and Letermovir as potential repurposed drug candidate for COVID-19 treatment: insights from an in-silico study.

INTRODUCTION: Drug repurposing is the need of the hour considering the medical emergency caused by the COVID-19 pandemic. Recently, cytokine storm by the host immune system has been linked with high viral load, loss of lung function, acute respiratory distress syndrome (ARDS), multiple organ failure, and subsequent fatal outcome. OBJECTIVE: This study aimed to identify potential FDA approved drugs that can be repurposed for COVID-19 treatment using an in-silico analysis. METHODS: In this study, virtual screening of selected FDA approved drugs was performed by targeting the main protease (Mpro) of SARS-CoV-2 and the key molecules involved in the 'Cytokine storm' in COVID-19 patients. Based on our preliminary screening supported by extensive literature search, we selected FDA approved drugs to target the SARS-CoV-2 main protease (Mpro) and the key players of cytokine storm, TNF-α, IL-6, and IL-1ß. These compounds were examined based on systematic docking studies and further validated using a combination of molecular dynamics simulations and molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations. RESULTS: Based on the findings, Rifampicin and Letermovir appeared as the most promising drug showing a very good binding affinity with the main protease of SARS-CoV-2 and TNF-α, IL-6, and IL-1ß. However, it is pertinent to mention here that our findings need further validation by in vitro analysis and clinical trials. CONCLUSION: This study provides an insight into the drug repurposing approach in which several FDA approved drugs were examined to inhibit COVID-19 infection by targeting the main protease of SARS-COV-2 and the cytokine storm.