Rostamizadeh Leila, Ramezani Mina, Monirinasab Hannaneh, Rostamizadeh Kobra, Sabzichi Mehdi, Bahavarnia Seied Rafi, Osouli-Bostanabad Karim, Ramezani Fatemeh, Molavi Ommoleila
Department of Molecular Medicine, Faculty of Advanced Medical Science, Tabriz University of Medical Sciences, Golgasht Avenue, Tabriz, Iran.
Faculty of Medical Science, Department of Anatomical Science, Tarbiat Modares University, Tehran, Iran.
Naunyn Schmiedebergs Arch Pharmacol. 2025 May;398(5):5867-5880. doi: 10.1007/s00210-024-03658-8. Epub 2024 Nov 30.
The immunosuppressive tumor microenvironment (TME) plays a pivotal role in the response to various anticancer therapies, such as immune and chemotherapeutic agents. In this study, the synergistic effects of gene-targeting HIF-1α siRNA combined with Toll-Like Receptor 7 agonist on TME remodeling were investigated in a mouse model of colorectal cancer (CRC). A HIF-1α-specific siRNA duplex was formulated based on the ionic gelation of tripolyphosphate (TPP) with cationic chitosan (CH) as a nanoplex and evaluated in terms of size, charge, polydispersity index and gel retardation assay. MTT assay was conducted to assess the cytotoxicity of the specific siRNA duplex against CT26 cells. Hypoxic condition was generated to evaluate the gene and protein expression levels of HIF-1α, respectively. CT26 mouse model was established to assess the synergistic effect of silencing HIF-1α combined with oxaliplatin (OXA) and imiquimod (IMQ) on tumor growth. The mean diameter of the CH/siRNA nanoparticles was 243 ± 6 nm, as confirmed with Micrograph scanning electron microscope. There were no significant differences observed between the CT26 cells treated with nanoparticles alone and the untreated cells, indicating that these nanoparticles are safe and physiologically biocompatible (p ≥ 0.05). Triple combination therapy involving HIF-1α siRNA, OXA, and IMQ significantly retarded tumor growth and led to elevated levels of cytokines linked to cellular immunity (INF-γ and IL-12) compared with those in the other groups (P < 0.05). The positive correlation coefficient (r = 0.68) between tumor size and HIF-1α expression levels was statistically significant (P = 0.003). Compared with those in the control group, the expression levels of the anti-inflammatory cytokines IL-10 and IL-4 significantly decreased (P < 0.05). In conclusion, our findings suggest that inhibiting HIF-1α could serve as a rational strategy to enhance the antitumor response in the TME.
免疫抑制性肿瘤微环境（TME）在对各种抗癌疗法（如免疫和化学治疗药物）的反应中起关键作用。在本研究中，在结直肠癌（CRC）小鼠模型中研究了靶向缺氧诱导因子-1α（HIF-1α）的小干扰RNA（siRNA）与Toll样受体7激动剂联合对TME重塑的协同作用。基于三聚磷酸（TPP）与阳离子壳聚糖（CH）的离子凝胶化制备了HIF-1α特异性siRNA双链体纳米复合物，并通过尺寸、电荷、多分散指数和凝胶阻滞试验进行评估。进行MTT试验以评估特异性siRNA双链体对CT26细胞的细胞毒性。通过产生缺氧条件分别评估HIF-1α的基因和蛋白表达水平。建立CT26小鼠模型以评估沉默HIF-1α联合奥沙利铂（OXA）和咪喹莫特（IMQ）对肿瘤生长的协同作用。用扫描电子显微镜确认CH/siRNA纳米颗粒的平均直径为243±6nm。单独用纳米颗粒处理的CT26细胞与未处理的细胞之间未观察到显著差异，表明这些纳米颗粒是安全的且具有生理生物相容性（p≥0.05）。与其他组相比，涉及HIF-1α siRNA、OXA和IMQ的三联联合疗法显著抑制肿瘤生长，并导致与细胞免疫相关的细胞因子（INF-γ和IL-12）水平升高（P<0.05）。肿瘤大小与HIF-1α表达水平之间的正相关系数（r=0.68）具有统计学意义（P=0.003）。与对照组相比，抗炎细胞因子IL-10和IL-4的表达水平显著降低（P<0.05）。总之，我们的研究结果表明，抑制HIF-1α可作为增强TME中抗肿瘤反应的合理策略。
