Abstract：
Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer lacks estrogen, progesterone, and HER2 receptors and hence, is therapeutically challenging. Towards this, we studied an alternate therapy by repurposing metformin (FDA-approved type-2 diabetic drug with anticancer properties) in a 3D-scaffold culture, with electrical pulses. 3D cell culture was used to simulate the tumor microenvironment more closely and MDA-MB-231, human TNBC cells, treated with both 5 mM metformin (Met) and 8 electrical pulses at 2500 V/cm, 10 µs (EP1) and 800 V/cm, 100 µs (EP2) at 1 Hz were studied in 3D and 2D. They were characterized using cell viability, reactive oxygen species (ROS), glucose uptake, and lactate production assays at 24 h. Cell viability, as low as 20 % was obtained with EP1 + 5 mM Met. They exhibited 1.65-fold lower cell viability than 2D with EP1 + 5 mM Met. ROS levels indicated a 2-fold increase in oxidative stress for EP1 + 5 mM Met, while the glucose uptake was limited to only 9 %. No significant change in the lactate production indicated glycolytic arrest and a non-conducive environment for MDA-MB-231 growth. Our results indicate that 3D cell culture, with a more realistic tumor environment that enhances cell death using metformin and electrical pulses could be a promising approach for TNBC therapeutic intervention studies.
摘要：
三阴性乳腺癌（TNBC），最具侵袭性的乳腺癌亚型缺乏雌激素，黄体酮,和HER2受体，因此，具有治疗挑战性。为此，我们通过在3D支架培养物中重新利用二甲双胍（FDA批准的具有抗癌特性的2型糖尿病药物）研究了一种替代疗法，用电脉冲。3D细胞培养用于更紧密地模拟肿瘤微环境和MDA-MB-231，人TNBC细胞，用5mM二甲双胍（Met）和8个2500V/cm的电脉冲处理，10µs（EP1）和800V/cm，在3D和2D中研究了1Hz下的100µs（EP2）。用细胞活力来表征它们，活性氧（ROS），葡萄糖摄取，和乳酸生产测定在24小时。细胞活力，用EP1+5mMMet获得低至20%。在EP1+5mMet的情况下,它们表现出比2D低1.65倍的细胞活力。ROS水平表明EP1+5mMMet的氧化应激增加了2倍，而葡萄糖摄取仅限于9%。乳酸产生没有显着变化，表明糖酵解停滞和不利于MDA-MB-231生长的环境。我们的结果表明，3D细胞培养，使用二甲双胍和电脉冲增强细胞死亡的更现实的肿瘤环境可能是TNBC治疗干预研究的有希望的方法。
