Radiolabeled GX1 Peptide for Tumor Angiogenesis Imaging

Role of PET/CT in diagnosing and monitoring disease activity in rheumatoid arthritis: a review

Rheumatoid Arthritis (RA) is a systemic inflammatory disorder that commonly presents with polyarthritis but can have multisystemic involvement and complications, leading to increased morbidity and mortality. The diagnosis of RA continues to be challenging due to its varied clinical presentations. In this review article, we aim to determine the potential of PET/CT to assist in the diagnosis of RA and its complications, evaluate the therapeutic response to treatment, and predict RA remission. PET/CT has increasingly been used in the last decade to diagnose, monitor treatment response, predict remissions, and diagnose subclinical complications in RA. PET imaging with [18F]-fluorodeoxyglucose ([18F]-FDG) is the most commonly applied radiotracer in RA, but other tracers are also being studied. PET/CT with [18F]-FDG, [18F]-NaF, and other tracers might lead to early identification of RA and timely evidence-based clinical management, decreasing morbidity and mortality. Although PET/CT has been evolving as a promising tool for evaluating and managing RA, more evidence is required before incorporating PET/CT in the standard clinical management of RA.

188Re-labeled GX1 dimer as a novel dual-functional probe targeting TGM2 for imaging and antiangiogenic therapy of gastric cancer

PURPOSE

The GX1 peptide (CGNSNPKSC) can specifically bind to TGM2 and possesses the ability to target the blood vessels of gastric cancer. This study intends to develop an integrated dual-functional probe with higher affinity, specificity and targeting and to characterize it in vivo and in vitro.

METHODS

The dimer and tetramer of GX1 were prepared using cross-linked PEG and labeled with ^99mTc. The best targeting probe [PEG-(GX1)₂] was selected by gamma camera imaging in nude mouse models of gastric cancer. ¹⁸⁸Re-PEG-(GX1)₂ was prepared and characterized through cell binding analysis and competitive inhibition experiments, gamma camera imaging, MTT analysis and flow cytometry, BLI, immunohistochemistry, HE staining and biochemical analysis.

RESULTS

PEG-(GX1)₂ bound specifically to Co-HUVEC with higher affinity than GX1. ¹⁸⁸Re-PEG-(GX1)₂ had better ability to target gastric cancer in tumor-bearing nude mice and higher T/H ratios than ¹⁸⁸Re-GX1. ¹⁸⁸Re-PEG-(GX1)₂ inhibited the growth of Co-HUVEC and induced apoptosis, and its effects were more robust than those of ¹⁸⁸Re-GX1. BLI showed that ¹⁸⁸Re-PEG-(GX1)₂ inhibited tumor proliferation in vivo with a stronger effect than ¹⁸⁸Re-GX1. Compared with ¹⁸⁸Re-GX1, ¹⁸⁸Re-PEG-(GX1)₂ suppressed tumor angiogenesis and tumor cell proliferation and induced tumor cell apoptosis in vivo. The ¹⁸⁸Re-PEG-(GX1)₂ group did not cause visible changes in liver and kidney morphology and function in vivo.

CONCLUSION

The dimer of GX1 was synthesized by using cross-linked PEG, and then ¹⁸⁸Re-PEG-(GX1)₂ was prepared. This radiopharmaceutical played both diagnostic and therapeutic functions, and gamma camera imaging could be utilized to detect the distribution of drugs in vivo during treatment. Through a series of experiments in vitro and in vivo, the feasibility of the drug was confirmed, and these results laid the foundation for the subsequent development and application of GX1.