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

LINC01589 serves as a potential tumor-suppressor and immune-related biomarker in endometrial cancer: A review

Currently, increasing attention is being paid to biomarkers in endometrial cancer. Immune infiltration of the tumor microenvironment has been shown to significantly affect the overall survival (OS) of uterine corpus endometrial carcinoma (UCEC) patients. LINC01589 is a long non-coding RNA (lncRNA) that is rarely reported in cancer and is assumed to play a role in immune regulation. We therefore evaluated the role of LINC01589 in UCEC using the Cancer Genome Atlas (TCGA) database. We analyzed the expression of LINC01589 using the gene expression profiles of LINC01589 in the UCEC projects in TCGA. Comparisons between the differentially expressed genes (DEGs) of the cancer and adjacent normal tissues of the UCEC projects revealed that LINC01589 expression was decreased in UCEC tissues. A multivariate cox regression analysis indicated that LINC01589 upregulation could serve as an independent prognostic factor for survival. Furthermore, there was a positive correlation between LINC01589 expression and B cell, T cell, NK cell, monocytic lineage, and myeloid dendritic cell infiltration in UCEC patients. In addition, 5 clusters of hub genes were detected by comparison of different expression levels of LINC01589 in the UCEC groups. The analysis of the reactome pathway using gene set enrichment analysis (GSEA) revealed immune-related pathways, including CD22-mediated B cell receptor (BCR) regulation and antigen-activated BCRs, leading to the generation of second messengers and complement cascade pathways that were significantly enriched in the high LINC01589 expression group. Thus, LINC01589 may serve as a prognostic biomarker, as it is associated with immune infiltration in UCEC.

An oligomeric hyaluronic acid-GX1 molecular target drug with polyvalent targeting to CD44 and VEGF receptors

The off-target toxicity of molecular targeted drug hinders its clinical transformation. Herein, we report a new molecular targeted drug oHA-GX1 constructed by oligomeric hyaluronan (oHA) and peptide GX1 (CGNSNPKSC). The oHA-GX1 can not only suppress the tumor growth by interacting with overexpressed VEGF and CD44 receptors inside tumor tissues, but also reduce the likelihood of off-target toxicity due to the multiple VEGF and CD44 receptors binding sites. The cytotoxicity study shows that the IC₅₀^oHA-GX1 against co-SGC-7901 and co-HUVEC cells fell in the range of common cytotoxic drugs. The animal experiment results reveal that the tumor inhibition rate of oHA-GX1 (100 mg/kg) against SGC-7901 tumor-bearing mice were 78.4 %, which was comparable to that of front-line chemotherapy drugs. Also, the cytotoxicity study on normal cells, hemolysis test, hemagglutination assay and the acute toxicity test demonstrate that oHA-GX1 exhibited excellent biosafety. This molecular targeted drug that utilizes the multiple receptor-binding sites to get rid of the side effects caused by off-target paves a new direction for the discovery of anticancer drugs with high efficacy and low adverse effects.

The tumour neovasculature-homing dimeric peptide GX1 demonstrates antiangiogenic activity in the retinal neovasculature

Identification of molecules specific to the retinal neovasculature will promote antiangiogenic therapy with enhanced targeting ability. The specificity of phage-displayed peptide GX1 (a cyclic 7-mer peptide motif CGNSNPKSC) to gastric cancer neovasculature has been extensively confirmed both in vitro and in vivo. To investigate the potential application of GX1 in antiangiogenic therapy targeting retinal angiogenesis-related diseases, we performed immunohistochemistry and immunofluorescence analyses. GX1 demonstrated positive staining in the retinal neovasculature in an oxygen-induced mouse model of retinopathy (OIR) as well as in rat retinal microvasculature endothelial cells (RMECs), confirming the major role of the GX1 receptor during retinal angiogenesis. Dimeric GX1 was synthesized to increase the binding affinity to the GX1 receptor, and the antiangiogenic effects were examined in RMECs in vitro and the retinal neovasculature in the OIR in vivo. Cell proliferation was evaluated using a Cell Counting Kit-8 (CCK-8) assay, revealing that compared with the GX1 monomer, dimeric GX1 significantly inhibited RMEC proliferation (P < 0.05). This finding may be attributed to the enhanced (P < 0.05) apoptosis induced by dimeric GX1 in RMECs based on results obtained from TUNEL, flow cytometric and cell cycle analyses. In RMECs, in vitro cell migration and tube formation were significantly inhibited following exposure to dimeric GX1. Intravitreal administration of dimeric GX1 resulted in a greater reduction in the retinal neovascularization in vivo than administration of the GX1 monomer (P < 0.05). In conclusion, dimeric GX1 showed greater inhibition of angiogenesis than monomeric GX1 and could be a promising agent for antiangiogenic therapy in retinal angiogenesis-related diseases.

68Ga-Labeled GX1 Dimer: A Novel Probe for PET/Cerenkov Imaging Targeting Gastric Cancer

Purpose

To synthesize the dimer of GX1 and identify whether its affinity and targeting are better than those of GX1. To prepare ⁶⁸Ga-DOTA-KEK-(GX1)₂ and to apply it to PET and Cerenkov imaging of gastric cancer.

Methods

⁶⁸Ga-DOTA-KEK-(GX1)₂ was prepared, and the labeling yield and stability were determined. Its specificity and affinity were verified using an in vitro cell binding assay and competitive inhibition test, cell immunofluorescence, and cell uptake and efflux study. Its tumor-targeting ability was determined by nano PET/CT and Cerenkov imaging, standardized uptake value (SUV), signal-to-background ratio (SBR) quantification, and a biodistribution study in tumor-bearing nude mice.

Results

⁶⁸Ga-DOTA-KEK-(GX1)₂ was successfully prepared, and the labeling yield was more than 97%. It existed stably for 90 min in serum. The binding of ⁶⁸Ga-DOTA-KEK-(GX1)₂ to cocultured HUVECs (Co-HUVECs) was higher than that to human umbilical vein endothelial cells (HUVECs), BGC823 cells, and GES cells. It was also higher than that of ⁶⁸Ga-DOTA-GX1, indicating that the dimer did improve the specificity and affinity of GX1. The binding of KEK-(GX1)₂ to Co-HUVECs was significantly higher than that of GX1. Additionally, the uptake of ⁶⁸Ga-DOTA-KEK-(GX1)₂ by Co-HUVECs was higher than that of ⁶⁸Ga-DOTA-GX1 and reached a maximum at 60 min. Nano PET/CT and Cerenkov imaging showed that the tumor imaging of the nude mice injected with ⁶⁸Ga-DOTA-KEK-(GX1)₂ was clear, and the SUV and SBR value of the tumor sites were significantly higher than those of the nude mice injected with ⁶⁸Ga-DOTA-GX1, indicating that the probe had better targeting in vivo. Finally, the biodistribution showed quantitatively that when organs such as the kidney and liver metabolized rapidly, the radioactivity of the tumor site of the nude mice injected with ⁶⁸Ga-DOTA-KEK-(GX1)₂ decreased relatively slowly. At the same time, the percentage of injected dose per gram (%ID/g) of the tumor site was higher than that of other normal organs except the liver and kidney at 60 min, which indicated that the tumor had good absorption of the probe.

Conclusion

GX1 was modified successfully, and the in vivo and in vitro properties of the GX1 dimer were significantly better than those of GX1. The imaging probe, ⁶⁸Ga-DOTA-KEK-(GX1)₂, was successfully prepared, which provides a candidate probe for PET and Cerenkov diagnosis of gastric cancer.