BthTX-I from Bothrops jararacussu induces apoptosis in human breast cancer cell lines and decreases cancer stem cell subpopulation

Abstract

Background: Breast cancer is the neoplasm with both the highest incidence and mortality rate among women worldwide. Given the known snake venom cytotoxicity towards several tumor types, we evaluated the effects of BthTX-I from Bothrops jararacussu on MCF7, SKBR3, and MDAMB231 breast cancer cell lines. Methods: BthTX-I cytotoxicity was determined via MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazoliumbromide] assay. Cell death was measured by a hypotonic fluorescent solution method, annexin-V-FITC/propidium iodide staining and by apoptotic/autophagic protein expression. Cancer stem cells (CSCs) were quantified by flow cytometry using anti-CD24-FITC and anti-CD44-APC antibodies and propidium iodide. Results: BthTX-I at 102 µg/mL induced cell death in all cell lines. The toxin induced apoptosis in MCF7, SKBR3, and MDAMB231 in a dose-dependent manner, as confirmed by the increasing number of hypodiploid nuclei. Expression of pro-caspase 3, pro-caspase 8 and Beclin-1 proteins were increased, while the level of the antiapoptotic protein Bcl-2 was diminished in MCF7 cells. BthTX-I changed the staining pattern of CSCs in MDAMB231 cells by increasing expression of CD24 receptors, which mediated cell death. Conclusions: BthTX-I induces apoptosis and autophagy in all breast cancer cell lines tested and also reduces CSCs subpopulation, which makes it a promising therapeutic alternative for breast cancer.

Anticancer potential of nanogold conjugated toxin GNP-NN-32 from Naja naja venom

“…In this context, this study indicated that GNP-NN 32 was capable of inducing apoptosis at a concentration of 1.5 μg/mL in MCF-7 cell line and 5 μg/mL in MDA-MB-231 cell line. Our results are in agreement with other studies that discovered that disintegrin from Crotalus durissus collilineatus venom induced cytotoxicity [37] whereas BthTX-I from Bothrops jararacussu induced apoptosis [38] and also showed antitumor and antimetastatic effects [39] on human breast cancer cell lines.…”

Anticancer potential of nanogold conjugated toxin GNP-NN-32 from Naja naja venom

“…In this context, this study indicated that GNP-NN 32 was capable of inducing apoptosis at a concentration of 1.5 μg/mL in MCF-7 cell line and 5 μg/mL in MDA-MB-231 cell line. Our results are in agreement with other studies that discovered that disintegrin from Crotalus durissus collilineatus venom induced cytotoxicity [37] whereas BthTX-I from Bothrops jararacussu induced apoptosis [38] and also showed antitumor and antimetastatic effects [39] on human breast cancer cell lines.…”

Recombinant BaMtx Preserves the Biological Properties of a Lys49 Phospholipase A2 from Bothrops atrox and Reveals Differential Responses in Tumor and Non-Tumor Cell Models

“…As an initial in vitro evaluation using the murine 4T1 breast carcinoma cell line, rBaMtx produced a concentration-dependent reduction in metabolic viability, with an IC 50 of approximately 60.94 µg/mL. This value falls within the range reported for other basic Lys49-PLA 2 homologues, including BthTX-I and BnSP-6 [29,30]. Cells treated with 50 and 100 µg/mL rBaMtx exhibited cell shrinkage, rounding, clustering, and increased intercellular spaces.…”

Anticancer Activity of Snake Venom Against Breast Cancer: A Scoping Review

“…These findings were further supported by Badr et al (2014) [ 41 ], who observed similar increases in caspase activity in human breast cancer tissue samples, suggesting the involvement of both mitochondrial and death receptor-mediated apoptosis. Consistent with these results, Bezerra et al (2019) [ 20 ] demonstrated that BthTX-I, a Lys49-PLA 2 from Bothrops jararacussu , upregulated pro-caspase-3 and -8 while downregulating Bcl-2 in MCF-7 cells, indicating activation of the caspase cascade and suppression of survival signaling. Similarly, Malekara et al (2020) [ 32 ] reported that Vipera raddei kurdistanica venom induced apoptosis in MCF-7 and MDA-MB-231 cells by increasing BAX expression and decreasing BCL-2, further supporting the role of mitochondria-dependent apoptosis.…”

“…After screening titles and abstracts, 205 articles unrelated to snake venom and breast cancer were excluded. Full texts of the remaining 38 studies were assessed, and 26 studies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] were ultimately included in our review. These studies were conducted across 15 countries.…”

Anticancer potential of nanogold conjugated toxin GNP-NN-32 from Naja naja venom

“…In this context, this study indicated that GNP-NN 32 was capable of inducing apoptosis at a concentration of 1.5 μg/mL in MCF-7 cell line and 5 μg/mL in MDA-MB-231 cell line. Our results are in agreement with other studies that discovered that disintegrin from Crotalus durissus collilineatus venom induced cytotoxicity [37] whereas BthTX-I from Bothrops jararacussu induced apoptosis [38] and also showed antitumor and antimetastatic effects [39] on human breast cancer cell lines.…”

Recombinant BaMtx Preserves the Biological Properties of a Lys49 Phospholipase A2 from Bothrops atrox and Reveals Differential Responses in Tumor and Non-Tumor Cell Models

“…As an initial in vitro evaluation using the murine 4T1 breast carcinoma cell line, rBaMtx produced a concentration-dependent reduction in metabolic viability, with an IC 50 of approximately 60.94 µg/mL. This value falls within the range reported for other basic Lys49-PLA 2 homologues, including BthTX-I and BnSP-6 [29,30]. Cells treated with 50 and 100 µg/mL rBaMtx exhibited cell shrinkage, rounding, clustering, and increased intercellular spaces.…”

Anticancer Activity of Snake Venom Against Breast Cancer: A Scoping Review

“…These findings were further supported by Badr et al (2014) [ 41 ], who observed similar increases in caspase activity in human breast cancer tissue samples, suggesting the involvement of both mitochondrial and death receptor-mediated apoptosis. Consistent with these results, Bezerra et al (2019) [ 20 ] demonstrated that BthTX-I, a Lys49-PLA 2 from Bothrops jararacussu , upregulated pro-caspase-3 and -8 while downregulating Bcl-2 in MCF-7 cells, indicating activation of the caspase cascade and suppression of survival signaling. Similarly, Malekara et al (2020) [ 32 ] reported that Vipera raddei kurdistanica venom induced apoptosis in MCF-7 and MDA-MB-231 cells by increasing BAX expression and decreasing BCL-2, further supporting the role of mitochondria-dependent apoptosis.…”

“…After screening titles and abstracts, 205 articles unrelated to snake venom and breast cancer were excluded. Full texts of the remaining 38 studies were assessed, and 26 studies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] were ultimately included in our review. These studies were conducted across 15 countries.…”

Anticancer potential of nanogold conjugated toxin GNP-NN-32 from Naja naja venom

“…In this context, this study indicated that GNP-NN 32 was capable of inducing apoptosis at a concentration of 1.5 μg/mL in MCF-7 cell line and 5 μg/mL in MDA-MB-231 cell line. Our results are in agreement with other studies that discovered that disintegrin from Crotalus durissus collilineatus venom induced cytotoxicity [37] whereas BthTX-I from Bothrops jararacussu induced apoptosis [38] and also showed antitumor and antimetastatic effects [39] on human breast cancer cell lines.…”

Recombinant BaMtx Preserves the Biological Properties of a Lys49 Phospholipase A2 from Bothrops atrox and Reveals Differential Responses in Tumor and Non-Tumor Cell Models

“…As an initial in vitro evaluation using the murine 4T1 breast carcinoma cell line, rBaMtx produced a concentration-dependent reduction in metabolic viability, with an IC 50 of approximately 60.94 µg/mL. This value falls within the range reported for other basic Lys49-PLA 2 homologues, including BthTX-I and BnSP-6 [29,30]. Cells treated with 50 and 100 µg/mL rBaMtx exhibited cell shrinkage, rounding, clustering, and increased intercellular spaces.…”

Anticancer Activity of Snake Venom Against Breast Cancer: A Scoping Review

“…These findings were further supported by Badr et al (2014) [ 41 ], who observed similar increases in caspase activity in human breast cancer tissue samples, suggesting the involvement of both mitochondrial and death receptor-mediated apoptosis. Consistent with these results, Bezerra et al (2019) [ 20 ] demonstrated that BthTX-I, a Lys49-PLA 2 from Bothrops jararacussu , upregulated pro-caspase-3 and -8 while downregulating Bcl-2 in MCF-7 cells, indicating activation of the caspase cascade and suppression of survival signaling. Similarly, Malekara et al (2020) [ 32 ] reported that Vipera raddei kurdistanica venom induced apoptosis in MCF-7 and MDA-MB-231 cells by increasing BAX expression and decreasing BCL-2, further supporting the role of mitochondria-dependent apoptosis.…”

“…After screening titles and abstracts, 205 articles unrelated to snake venom and breast cancer were excluded. Full texts of the remaining 38 studies were assessed, and 26 studies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ] were ultimately included in our review. These studies were conducted across 15 countries.…”