Extracellular vesicles (EVs) attract much attention in liver pathology because they regulate cell–cell communication and many pathophysiological events by transferring their cargos. Monitoring and understanding the in vivo fate and therapeutic capacity of these EVs is critical for the development and optimization of EV-based diagnosis and therapy. Herein, we demonstrate the use of an aggregation-induced emission luminogen, DPA-SCP, for the real-time tracking of EVs derived from human placenta-derived mesenchymal stem cells (MSCs) and their therapeutic effects in a mouse acute liver injury (ALI) model. In vitro, DPA-SCP does not alter the inherent characteristics of MSC-derived EVs and shows extremely low toxicity. Moreover, DPA-SCP exhibited superior labeling efficiency and tracking capability to the most popular commercial EV trackers, PKH26 and DiI. In vivo, DPA-SCP precisely and quantitatively tracked the behaviors of EVs for 7 days in the mouse ALI model without influencing their regenerative capacity and therapeutic efficacy. The therapeutic effects of EVs may attribute to their ability for reducing inflammatory cell infiltration, enhancing cell survival and antiapoptotic effects. In conclusion, DPA-SCP with an AIE signature serves as a favorable and safe tracker for in vivo real-time imaging of EVs in liver regeneration.
The malignancy of colorectal cancer (CRC) is connected with inflammation and tumor-associated macrophages (TAMs), but effective therapeutics for CRC are limited. To integrate therapeutic targeting with tumor microenvironment (TME) reprogramming, here we develop biocompatible, non-covalent channel-type nanoparticles (CNPs) that are fabricated through host-guest complexation and self-assemble of mannose-modified γ-cyclodextrin (M-γ-CD) with Regorafenib (RG), RG@M-γ-CD CNPs. In addition to its carrier role, M-γ-CD serves as a targeting device and participates in TME regulation. RG@M-γ-CD CNPs attenuate inflammation and inhibit TAM activation by targeting macrophages. They also improve RG’s anti-tumor effect by potentiating kinase suppression. In vivo application shows that the channel-type formulation optimizes the pharmacokinetics and bio-distribution of RG. In colitis-associated cancer and CT26 mouse models, RG@M-γ-CD is proven to be a targeted, safe and effective anti-tumor nanomedicine that suppresses tumor cell proliferation, lesions neovascularization, and remodels TME. These findings indicate RG@M-γ-CD CNPs as a potential strategy for CRC treatment.
Purpose: The purpose of this study was to evaluate the capability of u-SPECT-II/CT to monitor the progression of breast cancer lung metastasis using 99m Tc-3P-RGD 2 as a radiotracer. Methods: The breast cancer lung metastasis model was established by tail-vein injection of 2 x 10 5 -1.5 x 10 6 MDA-MB-231 cells into each athymic nude mouse. SPECT/CT studies were performed at a specified time after inoculation of MDA-MB-231 cells. Histological staining was used to further confirm the presence of lung metastases. Results: We found that both inoculation time and tumor cell load had significant influence on the extent of lung metastasis. For example, if animals were injected with 2 x 10 5 MDA-MB-231 cells, there were no detectable metastatic breast tumors in the lungs after 8 weeks. If animals were injected with 1 x 10 6 MDA-MB-231 cells, there were many tumors in both lungs at week 8. When 1.5 x 10 6 MDA-MB-231 cells were injected, the animal became very weak by week 7. We also found a rare example of breast cancer metastasis in the muscle and mediastinal lymph nodes. The tumor necrotic regions were clearly delineated by u-SPECT-II/CT. Conclusion: This study clearly demonstrated that 99m Tc-3P-RGD 2 is an excellent radiotracer for noninvasive imaging of metastatic breast tumors in the lungs, mediastinal lymph nodes and muscles.99m Tc-3P-RGD 2 SPECT/CT is an outstanding platform for monitoring the progression of breast cancer lung metastases, semi-quantification of breast tumor load in the lungs and delineation of tumor necrosis in small animals.
This study sought to evaluate [99mTc(HYNIC-Galacto-RGD2)(tricine)(TPPTS)] (99mTc-Galacto-RGD2: HYNIC = 6-hydrazinonicotinyl; Galacto-RGD2 = Glu[cyclo[Arg-Gly-Asp-D-Phe-Lys(SAA-PEG2-(1,2,3-triazole)-1-yl-4-methylamide)]]2 (SAA = 7-amino-L-glycero-L-galacto-2,6-anhydro-7-deoxy-heptanamide, and PEG2 = 3,6-dioxaoctanoic acid); and TPPTS = trisodium triphenylphosphine-3,3',3"-trisulfonate) as a new radiotracer for tumor imaging. Galacto-RGD2 was prepared via the copper (I)-catalyzed 1,3-dipolar azide–alkyne Huisgen cycloaddition. HYNIC-Galacto-RGD2 was prepared by reacting Galacto-RGD2 with sodium succinimidyl 6-(2-(2-sulfonatobenzaldehyde)hydrazono)nicotinate (HYNIC-OSu) in the presence of diisopropylethylamine, and was evaluated for its integrin αvβ3 binding affinity against 125I-echistatin bound to U87MG glioma cells. The IC50 value for HYNIC-Galacto-RGD2 was determined to be 20 ± 2 nM. 99mTc-Galacto-RGD2 was prepared in high specific activity (~185 GBq/µmol) and high radiochemical purity (>95%), and was evaluated in athymic nude mice bearing U87MG glioma xenografts for its tumor-targeting capability and biodistribution. The tumor uptake of 99mTc-Galacto-RGD2 was 10.30 ± 1.67, 8.37 ± 2.13, 6.86 ± 1.33 and 5.61 ± 1.52 %ID/g at 5, 30, 60 and 120 min p.i., respectively, which was in agreement with high integrin αvβ3 expression on glioma cells and neovasculature. Its lower uptake in intestines, lungs and spleen suggests that 99mTc-Galacto-RGD2 has advantages over 99mTc-3P–RGD2 ([99mTc(HYNIC-3P–RGD2)(tricine)(TPPTS)]: 3P–RGD2 = PEG4-E[PEG4-c(RGDfK)]2; PEG4 = 15-amino-4,7,10,13-tetraoxapentadecanoic acid) for imaging tumors in the chest and abdominal regions. U87MG tumors were readily detected by SPECT and the tumor uptake of 99mTc-Galacto-RGD2 was integrin αvβ3-specific. 99mTc-Galacto-RGD2 also had very high metabolic stability. On the basis of results from this study, it was concluded that 99mTc-Galacto-RGD2 is an excellent radiotracer for imaging integrin αvβ3-positive tumors and related metastases.
Gastric cancer (GC) is one of the major diseases that threaten human health. Although the development of novel drugs has significantly improved the efficacy of GC chemotherapy, the 5-year survival rate of patients with GC remains unsatisfactory. In the present study, the role and mechanism of the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in GC proliferation was investigated. Clinical specimens and cancer cells were analyzed by western blotting or immunofluorescence. Reverse transcription-quantitative polymerase chain reaction analysis of 57 paired GC and non-tumorous tissues revealed elevated expression of MALAT1 in GC tissues compared with controls. In addition, increased MALAT1 was associated with elevated levels of microtubule-associated protein 1 light chain 3β (LC3B) and antigen Ki67, which are autophagy and proliferation markers, respectively. MTT and colony formation assay results demonstrated that MALAT1 promoted GC cell proliferation. To the best of our knowledge, the present study was the first to demonstrate that upregulated MALAT1 was associated with increased autophagy activation in GC tissues. Furthermore, this study reported that MALAT1 increased cell proliferation and enhanced autophagy activation in GC cells. In addition, the results revealed that MALAT1 inhibited microRNA (miR)-204 expression in GC cells. The present study also demonstrated that miR-204 repressed autophagy through the downregulation of LC3B and transient receptor potential melastatin 3 expression in GC cells. These results indicated that MALAT1 activated autophagy and promoted cell proliferation by downregulating miR-204 expression in GC.
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