A novel TOX3-WDR5-ABCG2 signaling axis regulates the progression of colorectal cancer by accelerating stem-like traits and chemoresistance.

The eradication of cancer stem cells (CSCs) with drug resistance confers the probability of local tumor control after chemotherapy or targeted therapy. As the main drug resistance marker, ABCG2 is also critical for colorectal cancer (CRC) evolution, in particular cancer stem-like traits expansion. Hitherto, the knowledge about the expression regulation of ABCG2, in particular its upstream transcriptional regulatory mechanisms, remains limited in cancer, including CRC. Here, ABCG2 was found to be markedly up-regulated in CRC CSCs (cCSCs) expansion and chemo-resistant CRC tissues and closely associated with CRC recurrence. Mechanistically, TOX3 was identified as a specific transcriptional factor to drive ABCG2 expression and subsequent cCSCs expansion and chemoresistance by binding to -261 to -141 segments of the ABCG2 promoter region. Moreover, we found that TOX3 recruited WDR5 to promote tri-methylation of H3K4 at the ABCG2 promoter in cCSCs, which further confers stem-like traits and chemoresistance to CRC by co-regulating the transcription of ABCG2. In line with this observation, TOX3, WDR5, and ABCG2 showed abnormal activation in chemo-resistant tumor tissues of in situ CRC mouse model and clinical investigation further demonstrated the comprehensive assessment of TOX3, WDR5, and ABCG2 could be a more efficient strategy for survival prediction of CRC patients with recurrence or metastasis. Thus, our study found that TOX3-WDR5/ABCG2 signaling axis plays a critical role in regulating CRC stem-like traits and chemoresistance, and a combination of chemotherapy with WDR5 inhibitors may induce synthetic lethality in ABCG2-deregulated tumors.

MED27 plays a tumor-promoting role in breast cancer progression by targeting KLF4.

The mediator complex usually cooperates with transcription factors to be involved in RNA polymerase II-mediated gene transcription. As one component of this complex, MED27 has been reported in our previous studies to promote thyroid cancer and melanoma progression. However, the precise function of MED27 in breast cancer development remains poorly understood. Here, we found that MED27 was more highly expressed in breast cancer samples than in normal tissues, especially in triple-negative breast cancer, and its expression level was elevated with the increase in pathological stage. MED27 knockdown in triple-negative breast cancer cells inhibited cancer cell metastasis and stemness maintenance, which was accompanied by downregulation of the expression of EMT- and stem traits-associated proteins, and vice versa in non-triple-negative breast cancer. Furthermore, MED27 knockdown sensitized breast cancer cells to epirubicin treatment by inducing cellular apoptosis and reducing tumorsphere-forming ability. Based on RNA-seq, we identified KLF4 as the possible downstream target of MED27. KLF4 overexpression reversed the MED27 silencing-mediated arrest of cellular metastasis and stemness maintenance capacity in breast cancer in vitro and in vivo. Mechanistically, MED27 transcriptionally regulated KLF4 by binding to its promoter region at positions -156 to +177. Collectively, our study not only demonstrated the tumor-promoting role of MED27 in breast cancer progression by transcriptionally targeting KLF4, but also suggested the possibility of developing the MED27/KLF4 signaling axis as a potential therapeutic target in breast cancer.

FTO Knockdown-Mediated Maturation of miR-383-5p Inhibits Malignant Advancement of Pancreatic Cancer by Targeting ITGA3.

m6A demethylase FTO is confirmed to be involved in pancreatic cancer progression. FTO regulates miRNA processing. To investigate the regulatory effect of FTO on miR-383-5p and its role in pancreatic cancer. The expression of miR-383-5p, ITGA3, and FTO was predicted using bioinformatic analysis in tissues and was measured using qPCR in cells. Cell biological functions were investigated using MTT assay, Transwell assay, sphere formation assay, and qPCR. The targeting relationship between miR-383-5p and ITGA3 was evaluated using the dual-luciferase reporter assay. The effect of FTO on miR-383-5p processing was evaluated using RIP and MeRIP assay. FTO expression was upregulated in pancreatic cancer and silencing of FTO promoted the processing of miR-383-5p in an m6A-dependent manner. m6A-modified miRNA processing was recognized by IGF2BP1. Downregulation of miR-383-5p reversed FTO knockdown-induced inhibition of cellular processes. The FTO/miR-383-5p/ITGA3 axis facilitated cell viability, metastasis, and stemness in pancreatic cancer.

Exosomes derived from mmu_circ_0000250-modified adipose-derived mesenchymal stem cells promote wound healing in diabetic mice by inducing miR-128-3p/SIRT1-mediated autophagy.

More and more evidence advises that circular RNAs (circRNAs) function critically in regulating different disease microenvironments. Our previous study found that autotransplantation of adipose-derived mesenchymal stem cells (ADSCs) promotes diabetes wound healing. Exosomes derived in ADSCs play an important regulatory role. This study aimed to characterize if mmu_circ_0000250 played a role in ADSC-exosome-mediated full-thickness skin wound repair in diabetic rats. Endothelial progenitor cells (EPCs) were selected to study the therapeutic mechanism of exosomes in high-glucose (HG)-induced cell damage and dysfunction. Analysis and luciferase reporter assay were utilized to explore the interaction among mmu_circ_0000250, miRNA (miR)-128-3p, and sirtuin (SIRT)1. The diabetic rats were used to confirm the therapeutic effect of mmu_circ_0000250 against exosome-mediated wound healing. Exosomes containing a high concentration of mmu_circ_0000250 had a greater therapeutic effect on restoration of the function of EPCs by promotion autophagy activation under HG conditions. Expression of mmu_circ_0000250 promoted SIRT1 expression by miR-128-3p adsorption, which was confirmed via luciferase reporter assay and bioinformatics analysis. In vivo, exosomes containing a high concentration of mmu_circ_0000250 had a more therapeutic effect on wound healing when compared with wild-type exosomes from ADSCs. Immunohistochemistry and immunofluorescence detection showed that mmu_circ_0000250 increased angiopoiesis with exosome treatment in wound skin and suppressed apoptosis by autophagy activation. In conclusion, we verified that mmu_circ_0000250 enhanced the therapeutic effect of ADSC-exosomes to promote wound healing in diabetes by absorption of miR-128-3p and upregulation of SIRT1. Therefore, these findings advocate targeting the mmu_circ_0000250/miR-128-3p/SIRT1 axis as a candidate therapeutic option for diabetic ulcers.

Self-Assembly of Lanthanide-Covalent Organic Polyhedra: Chameleonic Luminescence and Efficient Catalysis.

A series of multinuclear lanthanide-covalent organic polyhedra (LnCOPs), including pillar-typed triangular prisms 1-Ln3 and tetrahedra 2-Ln4 (Ln = LaIII, SmIII, EuIII), have been constructed for the first time, through either one-pot subcomponent self-assembly or postassembly metalation. In contrast to the known tetrahedral cages based on transition metals, the pillar-typed polyhedra were favored from the same organic components in the presence of lanthanides. Besides this, facile transmetalations between the 1-Ln3 polyhedra endow cascade chameleonic luminescence. Meanwhile, the open metal sites and pendent amine groups on 1-Ln3 enable these polyhedra to catalyze the Henry reaction efficiently.

Role and effect of vein-transplanted human umbilical cord mesenchymal stem cells in the repair of diabetic foot ulcers in rats.

Diabetic foot ulcer (DFU) is one of diabetic complications, which is frequently present and tormented in diabetes mellitus. Most multipotent mesenchymal stromal cells (MSCs) are capable of immune evasion, providing an allogeneic, ready-to-use, cell product option for therapeutic applications. The beneficial effect of MSCs for the treatment of a variety of traumatic injuries, such as open wounds, has been extensively explored. In this study, a rat DFU model was used to simulate the pathophysiology of clinical patients and to investigate the localization of human umbilical cord mesenchymal stem cells (hUC-MSCs) after intravenous transplantation and its role in DFU healing, so as to evaluate the potential of hUC-MSCs in the treatment of DFU. The diabetic rat model was established by streptozotocin injection, which was used to create full-thickness foot dorsal skin wounds to mimic DFU by a 6-mm skin biopsy punch and a Westcott scissor. The hUC-MSCs were transplanted through femoral vein, and the ulcer cicatrization situation and the fate of hUC-MSCs were evaluated. Our data suggest that intravenously transplantated hUC-MSCs have the ability to migrate and locate to the wound tissue and are helpful to wound healing in DFU rats, partly by regulating inflammation, trans-differentiation and providing growth factors that promote angiogenesis, cell proliferation and collagen deposition. Herein, we demonstrate that hUC-MSC transplantation is able to accelerate DFU healing in rats and transplantation of exogenous stem cells may be a potential strategy for clinical application in DFUs.

Nanosphere-mediated co-delivery of VEGF-A and PDGF-B genes for accelerating diabetic foot ulcers healing in rats.

Diabetic ischemic ulcer is an intractable diabetic complication. Angiogenesis is a critical factor for wound healing in patients with diabetic foot wounds. Sustained gene delivery could be notably necessary in modulating gene expression in chronic ulcer healing and might be a promising approach for diabetic foot ulcers. In the present study, Sprague-Dawley rats were used to establish diabetic foot ulcer models by streptozotocin and skin biopsy punch. The plasmids expressing VEGF-A and PDGF-B were prepared and then incorporated with polylactic-co-glycolic acid (PLGA) nanospheres to upregulate genes expression. The aim of this study was to explore whether the engineered VEGF-A and PDGF-B based plasmid-loaded nanospheres could be upregulated in streptozotocin-induced diabetic rats and improve the wound healing. The cultured fibroblasts could be effectively transfected by means of nanosphere/plasmid in vitro. In vivo, the expression of VEGF-A and PDGF-B was significantly upregulated at full-thickness foot dorsal skin wounds and the area of ulceration was progressively and significantly reduced following treatment with nanosphere/plasmid. These results indicated that combined gene transfer of VEGF-A and PDGF-B could improve reparative processes in the wounded skin of diabetic rats and nanosphere may be a potential non-viral vector for gene therapy of the diabetic foot ulcer.

Human primary CD34+ cells transplantation for critical limb ischemia.

BACKGROUND: The goal of this study was to characterize the properties of human CD34+ cells in culture and investigate the feasibility and efficacy of CD34+ transplantation in a mouse model of limb ischemia and in patients with no-option critical limb ischemia. METHODS: Human CD34+ cells isolated from peripheral blood and grown in culture for up to four passages stained positively for the surface markers CD34 and CD133 and showed high viability after cryopreservation and recovery. Seven days after surgery to induce limb ischemia, ischemic muscles of nude mice were injected with CD34+ cells. Two weeks later, mice were scored for extent of ischemic injury, and muscle tissue was collected for immunohistochemical analysis of vascular endothelial cells and RT-PCR analysis of cytokine expression. RESULTS: Injury scores of CD34+ -treated, but not control, mice were significantly different before and after transplantation. Vascular density and expression of VEGF and bFGF mRNAs were also significantly increased in the treated mice. Patients with severe lower extremity arterial ischemia were injected with their own CD34+ cells in the affected calf, foot, or toe. Significant improvements were observed in peak pain-free walking time, ankle-brachial index, and transcutaneous partial oxygen pressure. These findings demonstrate that growth of human CD34+ cells in vitro and cryopreservations are feasible. CONCLUSION: Such cells may provide a renewable source of stem cells for transplantation, which appears to be a feasible, safe, and effective treatment for patients with critical limb ischemia.

MiR-31 regulates the function of diabetic endothelial progenitor cells by targeting Satb2.

Endothelial malfunctions in patients with diabetes are known to result in vascular diseases, and endothelial progenitor cells (EPCs) are indispensable for the functional preservation of the vascular endothelium. MicroRNA-31 (miR-31) has been found to be able to modulate the differentiation of stem cells. However, it is still unclear how miR-31 functions in diabetic EPCs. The aim of this study was to investigate how miR-31 regulates diabetic EPC function. In the current study, miR-31 expression was compared between normal and diabetic EPCs. Satb2 was recognized as a functionally related target of miR-31 in EPCs according to computational prediction. We also explored the role of miR-31 in terms of its anti-apoptotic effects. A remarkable elevation in miR-31 expression was found in diabetic EPCs, and this elevated expression resulted in suppressed cell proliferation under high glucose. It was also found that miR-31 targets Satb2, leading to the anti-apoptotic effect and maintenance of the functions of EPCs. Furthermore, knockdown of Satb2 exhibited an inhibitory effect on proliferation and migration of EPCs in both healthy and diabetic subjects, which showed the same trend as miR-31 overexpression. Conversely, overexpression of Satb2 showed the opposite effect. Moreover, overexpression of Satb2 attenuated the miR-31-induced migration and colony-forming ability reduction and apoptosis induction of EPCs in both healthy and diabetic subjects. In diabetic EPCs, elevated glucose level was found to up-regulate miR-31 expression, which in turn enhanced the malfunction and death of EPCs. In conclusion, our results indicate that up-regulation of miR-31 may underlie endothelial dysfunction in diabetes by targeting Satb2.

MicroRNA-182 promotes pancreatic cancer cell proliferation and migration by targeting ß-TrCP2.

Pancreatic cancer is an aggressive malignancy. The median survival rate remains low, indicating that the identification of novel biomarkers and therapeutic targets is critical. Here, we examined the role of microRNA-182 (miR-182) in pancreatic cancer development. Analysis of human pancreatic cancer specimens and cell lines showed that miR-182 is overexpressed in pancreatic cancer and promotes tumor proliferation and invasion. ß-TrCP2 was confirmed as a direct target of miR-182. Silencing of ß-TrCP2 increased the levels of ß-catenin, which is similar to miR-182 overexpression. Ectopic expression of ß-TrCP2 inhibited the miR-182-induced activation of ß-catenin signaling. The oncogenic effect of miR-182 and its reversal by ß-TrCP2 were confirmed in vivo This study suggests that ß-TrCP and miR-182 may be possible biomarkers and targets for early detection and treatment of pancreatic cancer.