Evaluation of phytoestrogens in inducing cell death mediated by decreasing Annexin A1 in Annexin A1-knockdown leukemia cells

Abstract

Background Phytoestrogens are plant compounds that are structurally similar to estrogen and that possess anti-cancer properties. Previous studies have reported that coumestrol, daidzein and genistein could induce cell death by reducing Annexin A1 protein in leukemic cell lines. Annexin A1 (ANXA1) is involved in cell progression, metastasis, and apoptosis in several types of cancer cells. The present study sought to investigate if the effects of phytoestrogens on apoptosis, cell cycle arrest and phagocytosis in ANXA1-knockdown leukemic cells are mediated through ANXA1 or occurred independently. Methods Transfection of ANXA1 siRNA was conducted to downregulate ANXA1 expression in Jurkat, K562 and U937 cells. Apoptosis and cell cycle assays were conducted using flow cytometry. Western blot was performed to evaluate ANXA1, caspases and Bcl-2 proteins expression. Phagocytosis was determined using hematoxylin and eosin staining. ResultsThe expression of ANXA1 after the knockdown was significantly downregulated in all cell lines. Genistein significantly induced apoptosis associated with an upregulation of procaspase-3, −9, and − 1 in Jurkat cells. The Bcl-2 expression showed no significant difference in Jurkat, K562 and U937 cells. Treatment with phytoestrogens increased procaspase-1 expression in Jurkat and U937 cells while no changes were detected in K562 cells. Flow cytometry analysis demonstrated that after ANXA1 knockdown, coumestrol and genistein caused cell cycle arrest at G2/M phase in selected type of cells. The percentage of phagocytosis and phagocytosis index increased after the treatment with phytoestrogens in all cell lines. Conclusion Phytoestrogens induced cell death in ANXA1-knockdown leukemia cells, mediated by Annexin A1 proteins. KeywordsAnnexin A1 . siRNA . Apoptosis . Caspase cascade . Cell cycle arrest . Phagocytosis . Human leukemic cell lines Abbreviations ANXA1 annexinA1 Annexin V-FITC annexin V-fluorescein PI propidium iodide RPMI-1640 Roswell Park Memorial Institute medium 1640 IMDM Iscove's modified Dulbecco's medium FBS fetal bovine serum siRNA small interfering RNA ER estrogen receptor * Endang Kumolosasi

Effect of fresh soy milk and its compounds on apoptosis in human leukemic cells and peripheral blood mononuclear cells

“…This result suggested that phytoestrogen compounds had strong killing effect toward leukemic cells and may be safe for normal cells, since higher percentage of apoptosis was possibly contributed to by a characteristic of cancer cells, which was more sensitive to the phytoestrogens as compared to normal cells. These results were in line with a previous study, where the same phytoestrogens induced apoptosis and cell cycle arrest in Annexin A1 (ANXA1)-knockdown leukemia cells [15]. Sabran et al reported that ANXA1 level was higher in leukemic cells compared to PBMC [16].…”

“…Furthermore, when ANXA1 in leukemic cells was knocked down, the cells exhibited apoptosis. Thus, phytoestrogen induced apoptosis might be mediated by ANXA1 [15]. These results were reinforced by Pignata et al, in which the study stated that apoptosis in normal cells might be due to a lengthy incubation period that could stimulate activation of cell death via initiation of mature T cells [17].…”

Phytoestrogen a combat kit against cancer

“…However, placebo effect shows no changes in isoflavones and placebo group which shows more research is needed (21). Another study suggests that soy intake in early life will help you in protection (26).…”

Estrogen Receptors Alpha and Beta in Acute Myeloid Leukemia

“…In AML, preclinical studies have shown that it induces cell death in a variety of leukemia cell lines and that a genistein-rich diet improves survival in leukemia-bearing mice [78]. Mechanistically, it has been shown to cause G2/M cell cycle arrest, increase reactive oxygen species (ROS) generation, cause mitochondrial membrane polarization, reduce protein synthesis through inhibition of mTOR, and change the BAX/Bcl2 ratio, leading to apoptosis [79][80][81]. Additionally, genistein and other polyphenols can enhance the anti-AML action of the glycolytic inhibitors 2-deoxy-D-glucose and lonidamine by inhibiting the compensatory activation of protein kinases such as Akt and extracellular signal-regulated kinase (ERK) [82].…”