Background: The role of alkaloids isolated from Rhazya stricta Decne (Apocynaceae family) (RS) in targeting genes involved in cancer and metastasis remains to be elucidated.
Objective: Identify and characterize new compounds from RS, which inhibit gene(s) involved in the survival, invasion, self-renewal, and metastatic processes of cancer cells.
Methods: Bioinformatics study was performed using HISAT2, stringtie, and ballgown pipeline to understand expressional differences between a normal epithelial cell line-MCF10A and MCF7. NMR and ATR-FTIR were performed to elucidate the structure of rhazyaminine (R.A), isolated from R stricta. Cell viability assay was performed using 0, 25, and 50 μg/mL of total extract of R stricta (TERS) and R.A, respectively, for 0, 24, and 48 hours, followed by scratch assay. In addition, total RNA was isolated for RNA- seq analysis of MCF7 cell line treated with R.A followed by qRT-PCR analysis of Bcl-2 gene.
Results: Deptor, which is upregulated in MCF7 compared with MCF10A as found in our bioinformatics study was downregulated by R.A. Furthermore, R.A effectively reduced cell viability to around 50% ( P < .05) and restricted cell migration in scratch assay. Thirteen genes, related to metastasis and cancer stem cells, were downregulated by R.A according to RNA- seq analysis. Additionally, qRT-PCR validated the downregulation of Bcl-2 gene in R.A-treated cells by less than 0.5 folds ( P < .05).
Conclusion: R.A successfully downregulated key genes involved in apoptosis, cell survival, epithelial-mesenchymal transition, cancer stem cell proliferation, and Wnt signal transduction pathway making it an excellent "lead candidate" molecule for in vivo proof-of-concept studies.
Keywords: alkaloids; apoptosis; breast cancer; cancer stem cells; metastasis; signaling pathways.