Veisaga Maria-Luisa, Ahumada Mariam, Soriano Stacy, Acuna Leonardo, Zhang Wei, Leung Ivy, Barnum Robert, Barbieri Manuel A
Biomolecular Sciences Institute, Florida International University, Miami, 33199, USA.
Department of Biological Sciences, Florida International University, Miami, 33199, USA.
Biocell. 2023 Aug 28;47(8):1835-1852.
Fruits and seed extracts of Annona montana have significant cytotoxic potential in several cancer cells. This study evaluates the effect of A. montana leaves hexane extract on several signaling cascades and gene expression in metastatic breast cancer cells upon insulin-like growth factor-1 (IGF-1) stimulation.
MTT assay was performed to determine the proliferation of cancer cells. Propidium iodide staining and flow cytometry analysis of Annexin V binding was utilized to measure the progression of the cell cycle and the induction of apoptosis. Protein expression and phosphorylation were determined by western blotting analysis to examine the underlying cellular mechanism triggered upon treatment with A. leaves hexane extract.
A. leaves hexane (sub-fraction V) blocked the constitutive stimulation of the PI3K/mTOR signaling pathways. This inhibitory effect was associated with apoptosis induction as evidenced by the positivity with Annexin V and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNNEL) staining, activation of caspase-3, and cleavage of PPAR. It also limited the expression of various downstream genes that regulate proliferation, survival, metastasis, and angiogenesis (i.e., cyclin D1, survivin, COX-2, and VEGF). It increased the expression of p53 and p21. Interestingly, we also observed that this extract blocked the activation of AKT and ERK without affecting the phosphorylation of the IGF-1 receptor and activation of Ras upon IGF-1 stimulation.
Our study indicates that A. leaves (sub-fraction V) extract exhibits a selective anti-proliferative and proapoptotic effect on the metastatic MDA-MB-231 breast cancer cells through the involvement of PI3K/AKT/mTOR/S6K1 pathways.
蒙塔纳番荔枝的果实和种子提取物在多种癌细胞中具有显著的细胞毒性潜力。本研究评估了蒙塔纳番荔枝叶己烷提取物对胰岛素样生长因子-1（IGF-1）刺激下转移性乳腺癌细胞中几种信号级联反应和基因表达的影响。
采用MTT法测定癌细胞的增殖。利用碘化丙啶染色和膜联蛋白V结合的流式细胞术分析来测量细胞周期进程和凋亡诱导情况。通过蛋白质印迹分析确定蛋白质表达和磷酸化，以检查用蒙塔纳番荔枝叶己烷提取物处理后触发的潜在细胞机制。
蒙塔纳番荔枝叶己烷（亚组分V）阻断了PI3K/mTOR信号通路的组成性刺激。这种抑制作用与凋亡诱导相关，膜联蛋白V阳性和末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）染色、半胱天冬酶-3的激活以及PPAR的裂解均证明了这一点。它还限制了调节增殖、存活、转移和血管生成的各种下游基因（即细胞周期蛋白D1、生存素、COX-2和VEGF）的表达。它增加了p53和p21的表达。有趣的是，我们还观察到该提取物阻断了AKT和ERK的激活，而不影响IGF-1刺激下IGF-1受体的磷酸化和Ras的激活。
我们的研究表明，蒙塔纳番荔枝叶（亚组分V）提取物通过PI3K/AKT/mTOR/S6K1途径对转移性MDA-MB-231乳腺癌细胞表现出选择性抗增殖和促凋亡作用。
