Bothrops moojeni L-amino acid oxidase induces apoptosis and epigenetic modulation on Bcr-Abl+ cells

Abstract

Background: Resistance to apoptosis in chronic myeloid leukemia (CML) is associated with constitutive tyrosine kinase activity of the Bcr-Abl oncoprotein. The deregulated expression of apoptosis-related genes and alteration in epigenetic machinery may also contribute to apoptosis resistance in CML. Tyrosine kinase inhibitors target the Bcr-Abl oncoprotein and are used in CML treatment. The resistance of CML patients to tyrosine kinase inhibitors has guided the search for new compounds that may induce apoptosis in Bcr-Abl + leukemic cells and improve the disease treatment. Methods: In the present study, we investigated whether the L-amino acid oxidase isolated from Bothrops moojeni snake venom (BmooLAAO-I) (i) was cytotoxic to Bcr-Abl + cell lines (HL-60.Bcr-Abl, K562-S, and K562-R), HL-60 (acute promyelocytic leukemia) cells, the non-tumor cell line HEK-293, and peripheral blood mononuclear cells (PBMC); and (ii) affected epigenetic mechanisms, including DNA methylation and microRNAs expression in vitro . Results: BmooLAAO-I induced ROS production, apoptosis, and differential DNA methylation pattern of regulatory apoptosis genes. The toxin upregulated expression of the pro-apoptotic genes BID and FADD and downregulated DFFA expression in leukemic cell lines, as well as increased miR-16 expression - whose major predicted target is the anti-apoptotic gene BCL2 - in Bcr-Abl + cells. Conclusion: BmooLAAO-I exerts selective antitumor action mediated by H 2 O 2 release and induces apoptosis, and alterations in epigenetic mechanisms. These results support future investigations on the effect of BmooLAAO-I on in vivo models to determine its potential in CML therapy.

P-I metalloproteinases and L-amino acid oxidases from Bothrops species inhibit angiogenesis

“…Further, Stábeli et al [ 54 ] isolated LAAO (64.8 kDa) from B. moojeni by ion-exchange chromatography and phenyl-sepharose chromatography. The LAAO isolated from both B. moojeni and B. atrox in the present study exhibited molecular mass of ~58 kDa protein as observed on SDS PAGE which is in the agreement with the previous studies [ 32 , 54 , 55 ].…”

Snake venom toxins: Potential anticancer therapeutics

“…BmooLAAO‐I isolated from B. moojeni venom was cytotoxic against Bcr‐Abl + leukaemic cells including HL‐60 (human promyelocytic leukaemia cells), HL‐60.Bcr‐Abl (HL‐60 infected with retrovirus carrying the BCR‐ABL1 gene), K562‐R (imatinib mesylate‐resistant Bcr‐Abl + cells) and K562‐S (imatinib mesylate‐sensitive Bcr‐Abl + cells) compared to non‐tumour HEK‐293 cell line, with IC50 of 0.038, 0.192, 0.116 and 0.148 μg/ml, respectively (Burin et al, 2020). This LAAO also induced apoptosis and altered epigenetic mechanisms including DNA methylation and microRNAs expression on these tumour cell lines.…”

“…Furthermore, Apoxin I oxidised L-leucine to generate H 2 O 2 and the apoptosis was inhibited by catalase (an H 2 O 2 scavenger), thus showing that H 2 O 2 generated through the L-amino acid oxidation plays a key role in the Apoxin I-induced apoptosis in the cancer cell lines. Apoxin I amino acid sequence shows the presence of an N-terminal signal sequence, flavin adenine dinucleotide (FAD) binding domain, carboxyl-terminal domain and posttranslational modification, such as N-glycosylation, which are believed to play key roles in its apoptosis-induction and LAAO activities(Torii et al, 2000).BmooLAAO-I isolated from B. moojeni venom was cytotoxic against Bcr-Abl + leukaemic cells including HL-60 (human promyelocytic leukaemia cells), HL-60.Bcr-Abl (HL-60 infected with retrovirus carrying the BCR-ABL1 gene), K562-R (imatinib mesylate-resistant Bcr-Abl + cells) and K562-S (imatinib mesylate-sensitive Bcr-Abl + cells) compared to non-tumour HEK-293 cell line, with IC50 of 0.038, 0.192, 0.116 and 0.148 μg/ml, respectively(Burin et al, 2020). This LAAO also induced apoptosis and altered epigenetic mechanisms including DNA methylation and microRNAs expression on these tumour cell lines.…”

Clinical Value of Serum miRNA in Patients with Acute Promyelocytic Leukemia

“…miRNA plays an important role in the pathogenesis of many diseases, including malignant hematological diseases. More and more evidence shows that abnormal expression of miRNA is common in malignant hematological diseases [9]. In recent years, it has been found that miRNA is related to the development of malignant hematological diseases [10].…”