First cloned human immortalized adipose derived mesenchymal stem-cell line with chimeric SS18-SSX1 gene (SS-iASC)

2-Mercaptoethanol enhances the yield of exosomes showing therapeutic potency in alleviating spinal cord injury mice

BACKGROUND

Limited passage numbers of mesenchymal stem cells (MSCs) present challenges in producing sufficient exosomes for spinal cord injury (SCI) treatment.

OBJECTIVES

This study investigates whether β-mercaptoethanol (BME) preconditioning of MSCs can increase exosome yield for SCI therapy.

METHODS

Exosomal content was analyzed using silver staining and SYBR Gold staining. Cell viability was assessed via CCK-8 and EdU assays. IL-1β, IL-6, TNF-α, and MCP-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Neuronal differentiation influenced by astrocytes was evaluated through neurite outgrowth and migration assays. Neuronal survival and motor function recovery in SCI mice were assessed using TUNEL staining, the Basso Mouse Scale (BMS), muscle strength tests, and motor evoked potential (MEP) measurements.

RESULTS

BME treatment significantly increased exosome quantity, including proteins and microRNAs, without drastic changes in exosomal content spectrum. Exosomes from BME-treated MSCs more effectively suppressed IL-1β, IL-6, TNF-α, and MCP-1 secretion by astrocytes, reducing neuronal inflammation. Yap1 activation reduced the exosomes' inhibitory effects on inflammatory cytokines. Mice treated with exosomes from BME-treated MSCs showed better outcomes: lower GFAP and C3 expression, reduced inflammation, increased NF-H levels, higher BMS scores, and greater MEP peaks. Exosome treatment also reduced bladder volume, residual urine, and the time to regain spontaneous urination after uroschesis.

CONCLUSION

BME preconditioning enhances exosome yield from hUC-MSCs, offering improved therapeutic potential for SCI.

Release of circulating tumor cells and cell-free nucleic acids is an infrequent event in synovial sarcoma: liquid biopsy analysis of 15 patients diagnosed with synovial sarcoma

BACKGROUND

Synovial sarcoma is a rare soft tissue tumor which contains the unique SS18-SSX1, SS18-SSX2 - or, rarely, SS18-SSX4 - fusion transcripts. It is well known that some soft tissue tumors, like Ewing sarcomas and myxoid liposarcomas, can spread via the blood with free circulating tumor cells (CTC); this can be detected by several sensitive molecular biology methods. Here we report a study of fifteen synovial sarcoma patients with varied clinical backgrounds.

METHOD

After blood withdrawal and nucleic acid isolation, we attempted to detect the SS18-SSX fusion genes from circulating tumor cells or cell-free nucleic acids with nested PCR and droplet digital PCR.

RESULTS

SS18-SSX2 fusion transcript was identified in a small copy number with droplet digital PCR in one case. Nested PCR could not detect any of the fusion transcripts in the examined 15 synovial sarcoma cases.

CONCLUSIONS

Heretofore two case reports could detect CTCs in synovial sarcoma - in the first paper, the patient was diagnosed with poorly differentiated type while the other had a rare primary gastric synovial sarcoma. However, until now, no other studies have detected CTCs in the peripheral blood of synovial sarcoma patients. Based on our findings, we can conclude that detection of the chimeric SS18-SSX fusion gene after surgical excision and/or chemotherapy/radiotherapy is a rare circumstance and hence in itself is not sufficient for monitoring the tumor recurrence. Therefore, monitoring of other possible biomarkers - for example synovial sarcoma specific miRNAs - is recommended.

The oncomir face of microRNA-206: A permanent miR-206 transfection study

MiR-206 is a remarkable miRNA because it functions as a suppressor miRNA in rhabdomyosarcoma while at the same time, as previously showed, it can act as an oncomiRNA in SMARCB1 immunonegative soft tissue sarcomas. The aim of this study was to investigate the effect of miR-206 on its several target genes in various human tumorous and normal cell lines. In the current work, we created miR-206-overexpressing cell lines (HT-1080, Caco2, iASC, and SS-iASC) using permanent transfection. mRNA expression of the target genes of miR-206 (SMARCB1, ACTL6A, CCND1, POLA1, NOTCH3, MET, and G6PD) and SMARCB1 protein expression were examined with quantitative real-time polymerase chain reaction, immunoblotting, immunocytochemistry, and flow cytometry. MiRNA inhibition was used to validate our results. We found a diverse silencing effect of miR-206 on its target genes. While an overall tendency of downregulation was noted, expression profiles of individual cell lines showed large variability. Only CCND1 and MET were consistently downregulated. MiR-206 had an antiproliferative effect on a normal human fibroblast cell line. A strong silencing effect of SMARCB1 in miR-206 transfected SS-iASC was most likely caused by the synergic influence of the SS18-SSX1 fusion protein and miR-206. In the same cell line, a moderate decrease of SMARCB1 protein expression could be observed with immunocytochemistry and flow cytometry. In the most comprehensive analysis of miR-206 effects so far, a modest but significant downregulation of miR-206 targets on the mRNA level was confirmed across all cell lines. However, the variability of the effect shows that the action of this miRNA is largely cell context-dependent. Our results also support the conception that the oncomiR effect of miR-206 on SMARCB1 plays an important but not exclusive role in SMARCB1 immunonegative soft tissue sarcomas so it can be considered important in planning the targeted therapy of these tumors in the future. Impact statement Mir-206 is a very unique microRNA because it can act as a suppressor miRNA or as an oncomiRNA depending on the tumor tissue. In SMARCB1 negative soft tissue sarcomas miR-206 is overexpressed, so thus in epithelioid and synovial sarcomas it functions as an oncomiRNA. MiR-206 has diverse silencing effects on its target genes. We found that the action of miR-206 is largely cell context dependent. The oncomiR role of miR-206 is crucial but not exclusive in SMARCB1 negative soft tissue sarcomas and miR-206 has an antiproliferative effect on a normal human fibroblast cell line. Expressions of miR-206 targets observed in tumors can only be reproduced in the corresponding tumorous cell lines. This is the first study which examined the permanent effect of miR-206 on its target genes in normal, tumor, and genetically engineered cell lines.