Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St, 90-236, Lodz, Poland.
Department of Surgical Oncology, Cancer Center, Copernicus Memorial Hospital, 62 Pabianicka St, 93-513, Lodz, Poland.
Pharm Res. 2019 Jul 31;36(10):140. doi: 10.1007/s11095-019-2673-9.
In order to overcome the obstacles and side effects of classical chemotherapy, numerous studies have been performed to develop the treatment based on targeted transport of active compounds directly to the site of action. Since tumor cells are featured with intensified glucose metabolism, we set out to develop innovative, glucose-modified PAMAM dendrimer for the delivery of doxorubicin to breast cancer cells.
PAMAM-dox-glc conjugate was synthesized and characterized by H NMR, FT-IR, size and zeta potential measurements. The drug release rate from conjugate was evaluated by dialysis under different pH conditions. The expression level of GLUT family receptors in cells cultured in full and glucose-deprived medium was evaluated by quantitative real-time RT-PCR and flow cytometry. The cytotoxicity of conjugate in presence or absence of GLUT1 inhibitors was determined by MTT assay.
We showed that PAMAM-dox-glc conjugate exhibits pH-dependent drug release and increased cytotoxic activity compared to free drug in cells cultured in medium without glucose. Further, we proved that these cells overexpress transporters of GLUT family. The toxic effect of conjugate was eliminated by the application of specific GLUT1 inhibitors.
Our findings revealed that the glucose moiety plays a crucial role in the recognition of cells with high expression of GLUT receptors. By selectively blocking GLUT1 transporter we showed its importance for the cytotoxic activity of PAMAM-dox-glc conjugate. These results suggest that PAMAM-glucose formulations may constitute an efficient platform for the specific delivery of anticancer drugs to tumor cells overexpressing transporters of GLUT family.
为了克服经典化疗的障碍和副作用，已经进行了大量研究，以开发基于将活性化合物靶向输送到作用部位的治疗方法。由于肿瘤细胞具有增强的葡萄糖代谢，我们着手开发创新的、葡萄糖修饰的 PAMAM 树枝状大分子，用于将阿霉素递送到乳腺癌细胞。
通过 H NMR、FT-IR、粒径和 zeta 电位测量对 PAMAM-dox-glc 缀合物进行了合成和表征。通过在不同 pH 条件下透析评估了缀合物的药物释放率。通过定量实时 RT-PCR 和流式细胞术评估了在完全和葡萄糖剥夺培养基中培养的细胞中 GLUT 家族受体的表达水平。通过 MTT 测定评估了缀合物在存在或不存在 GLUT1 抑制剂的情况下的细胞毒性。
我们表明，与在没有葡萄糖的培养基中培养的细胞中的游离药物相比，PAMAM-dox-glc 缀合物表现出 pH 依赖性药物释放和增加的细胞毒性。此外，我们证明这些细胞过度表达 GLUT 家族的转运蛋白。通过应用特定的 GLUT1 抑制剂消除了缀合物的毒性作用。
我们的研究结果表明，葡萄糖部分在识别高表达 GLUT 受体的细胞中起着至关重要的作用。通过选择性阻断 GLUT1 转运蛋白，我们表明其对 PAMAM-dox-glc 缀合物的细胞毒性活性的重要性。这些结果表明，PAMAM-葡萄糖制剂可能构成向过度表达 GLUT 家族转运蛋白的肿瘤细胞特异性递送抗癌药物的有效平台。
