Malignant glioma highly expresses carbonic anhydrase IX (CAIX). This study aimed to develop [177Lu]Lu-XYIMSR-01, a small-molecule therapeutic agent CAIX, to assess its potential for treating malignant glioma. [177Lu]Lu-XYIMSR-01 was synthesized by radiolabeling DOTA-XYIMSR-01 with 177Lu. In vitro assays were conducted to evaluate the affinity for U87MG tumor cells. The probe was injected via the tail vein into subcutaneous and orthotopic U87MG models for micro-SPECT/CT imaging. The survival rates of tumor-bearing mice were assessed after [177Lu]Lu-XYIMSR-01 injection by intratumoral in orthotopic models, including untreated controls and those treated with Temozolomide or combination therapy. After purification, the radiochemical yield of [177Lu]Lu-XYIMSR-01 was 86.47 ± 2.42%, with a radiochemical purity (RCP) of 99%. Its cell uptake in U87MG cells was 3.70 ± 0.57 ‰ AD/105 cells, significantly higher than that in HCT116 cells (0.68 ± 0.16 ‰ AD/105 cells, P = 0.001). In the biodistribution study, [177Lu]Lu-XYIMSR-01 uptake in U87MG tumors was 6.19 ± 1.37%ID/g, with a tumor/muscle ratio of 20.14 ± 3.24. In the orthotopic glioma model, local injection combined with Temozolomide significantly improved survival and inhibited tumor growth. The results indicate that [177Lu]Lu-XYIMSR-01 is a promising therapeutic molecular probe for targeting CAIX, and its combination with Temozolomide significantly enhances treatment outcomes for malignant glioma.
Kai Dong,Wenting Chen,Zhuangzhuang Zhao,Ying Zhang,Pengchong Wang,Ke Wang,Jianfeng Xing,Tingli Lu,Yalin Dong
The particularity of the tumor microenvironment (TME) significantly limits the efficiency of chemodynamic therapy (CDT). Although various measures have been taken to improve the efficiency of CDT, how to organically integrate them into one nanosystem to achieve efficient synergy for CDT according to predetermined procedures is still an urgent problem to be solved. This work reported a multifunctional nanosystem, TP I @PP CAI , which comprised the inner triphenylphosphine modified D-α-Tocopheryl polyethylene gly co l 1000 succinate (TPGS-PPh 3 ) micelles loading iron-oxide nanoparticles (IONs), and the outer poly (dopamine-co-protocatechuic acid) (PDA-PA, PP) coating modified with carbonic anhydrase IX inhibitor (CAI). TP I @PP CAI remodeled TME by sequential function adjustment to make it suitable for the efficient Fenton reactions: CAI first inhibited the overexpressed CA IX to result in intracellular acidification, which combined with near-infrared light (NIR) irradiation to accelerate the PP coating degradation, thereby promoting the exposure and disintegration of the inner micellar structure to release TPGS-PPh 3 and IONs. The TPGS-PPh 3 further elevated the intracellular ROS basal level by targeting and interfering with the mitochondrial function. Therefore, the TME was transformed into an acidic microenvironment with high ROS levels, which vigorously promoted the Fenton reaction mediated by IONs with the aid of photothermal effect induced by PP coating via NIR irradiation, ultimately earning high-efficiency CDT on xenograft MDA-MB-231 tumor-bearing mice. This study improved the efficiency of Fenton reaction in biological systems through the practical design of nanostructures and provided a novel thought for ROS-mediated therapy.