Erythropoietin Intensifies the Proapoptotic Activity of LFM-A13 in Cells and in a Mouse Model of Colorectal Cancer.

Anna Tankiewicz-Kwedlo,Krzysztof Bielawski,Robert Czarnomysy,Dariusz Pawlak,Izabela Prokop,Krystyna Pawlak,Justyna Hermanowicz

doi:10.3390/ijms19041262

Abstract

The Bruton’s tyrosine kinase (BTK) inhibitor LFM-A13 has been widely employed as an antileukemic agent, but applications in solid cancer have been found recently. The compound promotes apoptosis, has an antiproliferative effect, and increases cancer cell sensitivity to chemotherapy drugs. We decided to assess the impact of the simultaneous use of erythropoietin (Epo) and LFM-A13 on signal transduction in colon DLD-1 and HT-29 cells, as well as in tumor xenografts. The induction of apoptosis by Epo and LFM-A-13 in the cells was confirmed by phosphatidylserine externalization, loss of mitochondrial membrane potential, and modulation of the expression of apoptotic protein BAX and antiapoptotic protein BCL-2 in colon adenocarcinoma cells. Nude mice were inoculated with adenocarcinoma cells and treated with Epo and LFM-A13 in order to evaluate the degree of tumor regression. The simultaneous use of Epo and LFM-A13 severely inhibited cell growth, activated apoptosis, and also inhibited tumor growth in xenografts. The addition of Epo to LFM-A13 intensified the antiproliferative effect of LFM-A13, confirmed by the loss of mitochondrial membrane potential and the accumulation of apoptotic colon cancer cells with externalized phosphatidylserine (PS). These preclinical results suggest that the combination of Epo and LFM-A13 has a high proapoptotic activity and should be tested in the clinic for the treatment of solid tumors such as colon cancer.

Highlights

A dysfunctional apoptotic process can lead to both pathogenesis of colorectal cancer and its resistance to chemotherapy and radiotherapy [1]
Incubation of DLD-1 cells with 100 IU/mL of Epo and 30 or 100 μM of LFM-A13 decreased cell viability compared with the control (p < 0.001, p < 0.001 respectively) as well as with cells treated with 100 IU/mL of Epo (p < 0.001), 30 μM of
To illustrate the mechanism underlying the regulation of intracellular signal by the Epo and LFM-A13 combination, we investigated the status of the JAK2, AKT, and mitogen-activated protein kinases (MAPK) pathways in colon cancer cells

Summary

Introduction

A dysfunctional apoptotic process can lead to both pathogenesis of colorectal cancer and its resistance to chemotherapy and radiotherapy [1]. A cellular form of cell death, is currently an area interest for clinicians involved in colorectal cancer treatment and management [2]. Identifying novel intracellular proteins that play a crucial role in the growth and survival of colon cells has provided more effective therapies for cancer patients. Protein tyrosine kinase inhibitors are currently among the most promising drug types. Tyrosine kinases which often undergo mutations are the most commonly identified dominant oncogenes. Overexpression or activating mutation of these enzymes cause increased tumor cell proliferation and apoptosis evasion, while promoting angiogenesis and metastasis

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Conclusion