Shikonin as a WT1 Inhibitor Promotes Promyeloid Leukemia Cell Differentiation

Shikonin, a natural naphthoquinone phytochemical, exerts anti-leukemia effects in human CBF-AML cell lines and zebrafish xenograft models

Core binding factor acute myeloid leukemia (CBF-AML) stands out as the most common type of adult AML, characterized by specific chromosomal rearrangements involving CBF genes, particularly t(8;21). Shikonin (SHK), a naphthoquinone phytochemical widely employed as a food colorant and traditional Chinese herbal medicine, exhibits antioxidant, anti-inflammatory, and anti-cancer activities. In this study, we aim to investigate the antileukemic effects of SHK and its underlying mechanisms in human CBF-AML cells and zebrafish xenograft models. Our study revealed that SHK reduced the viability of CBF-AML cells. SHK induced cell cycle arrest, promoted cell apoptosis, and induced differentiation in Kasumi-1 cells. Additionally, SHK downregulated the gene expression of AML1-ETO and c-KIT in Kasumi-1 cells. In animal studies, SHK showed no toxic effects in zebrafish and markedly inhibited the growth of leukemia cells in zebrafish xenografts. Transcriptomic analysis showed that differentially expressed genes (DEGs) altered by SHK are linked to key biological processes like DNA repair, replication, cell cycle regulation, apoptosis, and division. Furthermore, KEGG pathways associated with cell growth, such as the cell cycle and p53 signaling pathway, were significantly enriched by DEGs. Analysis of AML-associated genes in response to SHK treatment using DisGeNET and the STRING database indicated that SHK downregulates the expression of cell division regulators regarding AML progression. Finally, we found that SHK combined with cytarabine synergistically reduced the viability of Kasumi-1 cells. In conclusion, our findings provide novel insights into the mechanisms of SHK in suppressing leukemia cell growth, suggesting its potential as a chemotherapeutic agent for human CBF-AML.

Label-free biomolecular and cellular methods in small molecule epigallocatechin-gallate research

Small molecule natural compounds are gaining popularity in biomedicine due to their easy access to wide structural diversity and their proven health benefits in several case studies. Affinity measurements of small molecules below 100 Da molecular weight in a label-free and automatized manner using small amounts of samples have now become a possibility and reviewed in the present work. We also highlight novel label-free setups with excellent time resolution, which is important for kinetic measurements of biomolecules and living cells. We summarize how molecular-scale affinity data can be obtained from the in-depth analysis of cellular kinetic signals. Unlike traditional measurements, label-free biosensors have made such measurements possible, even without the isolation of specific cellular receptors of interest. Throughout this review, we consider epigallocatechin gallate (EGCG) as an exemplary compound. EGCG, a catechin found in green tea, is a well-established anti-inflammatory and anti-cancer agent. It has undergone extensive examination in numerous studies, which typically rely on fluorescent-based methods to explore its effects on both healthy and tumor cells. The summarized research topics range from molecular interactions with proteins and biological films to the kinetics of cellular adhesion and movement on novel biomimetic interfaces in the presence of EGCG. While the direct impact of small molecules on living cells and biomolecules is relatively well investigated in the literature using traditional biological measurements, this review also highlights the indirect influence of these molecules on the cells by modifying their nano-environment. Moreover, we underscore the significance of novel high-throughput label-free techniques in small molecular measurements, facilitating the investigation of both molecular-scale interactions and cellular processes in one single experiment. This advancement opens the door to exploring more complex multicomponent models that were previously beyond the reach of traditional assays.

Shikonin Exerts an Antileukemia Effect against FLT3-ITD Mutated Acute Myeloid Leukemia Cells via Targeting FLT3 and Its Downstream Pathways

INTRODUCTION

Acute myeloid leukemia (AML) with internal tandem duplication (ITD) mutations in Fms-like tyrosine kinase 3 (FLT3) has an unfavorable prognosis. Recently, using newly emerging inhibitors of FLT3 has led to improved outcomes of patients with FLT3-ITD mutations. However, drug resistance and relapse continue to be significant challenges in the treatment of patients with FLT3-ITD mutations. This study aimed to evaluate the antileukemic effects of shikonin (SHK) and its mechanisms of action against AML cells with FLT3-ITD mutations in vitro and in vivo.

METHODS

The CCK-8 assay was used to analyze cell viability, and flow cytometry was used to detect cell apoptosis and differentiation. Western blotting and real-time polymerase chain reaction were used to examine the expression of certain proteins and genes. Leukemia mouse model was created to evaluate the antileukemia effect of SHK against FLT3-ITD mutated leukemia in vivo.

RESULTS

After screening a series of leukemia cell lines, those with FLT3-ITD mutations were found to be more sensitive to SHK in terms of proliferation inhibition and apoptosis induction than those without FLT3-ITD mutation. SHK suppresses the expression and phosphorylation of FLT3 receptors and their downstream molecules. Inhibition of the NF-κB/miR-155 pathway is an important mechanism through which SHK kills FLT3-AML cells. Moreover, a low concentration of SHK promotes the differentiation of AML cells with FLT3-ITD mutations. Finally, SHK could significantly inhibit the growth of MV4-11 cells in leukemia bearing mice.

CONCLUSION

The findings of this study indicate that SHK may be a promising drug for the treatment of FLT3-ITD mutated AML.

The anti-leukemia activity and mechanisms of shikonin: a mini review

Leukemia encompasses a group of highly heterogeneous diseases that pose a serious threat to human health. The long-term outcome of patients with leukemia still needs to be improved and new effective therapeutic strategies continue to be an unmet clinical need. Shikonin (SHK) is a naphthoquinone derivative that shows multiple biological function includes anti-tumor, anti-inflammatory, and anti-allergic effects. Numerous studies have reported the anti-leukemia activity of SHK during the last 3 decades and there are studies showing that SHK is particularly effective towards various leukemia cells compared to solid tumors. In this review, we will discuss the anti-leukemia effect of SHK and summarize the underlying mechanisms. Therefore, SHK may be a promising agent to be developed as an anti-leukemia drug.