Protective effects of EVs/exosomes derived from permanently growing human MSC on primary murine ALS motor neurons.

In recent years, the neuroprotective potential of mesenchymal stroma-/stem-like cells (MSC) as well as of MSC-derived extracellular vesicles (EVs) like exosomes has been intensively explored. This included preclinical evaluation regarding treatment of neurodegenerative disorders such as the fatal motor neuron disease amyotrophic Lateral Sclerosis (ALS). Several studies have reported that MSC-derived exosomes can stimulate tissue regeneration and reduce inflammation. MSC release EVs and trophic factors and thereby modify cell-to-cell communication. These cell-free products may protect degenerating motor neurons (MNs) and represent a potential therapeutic approach for ALS. In the present study we investigated the effects of exosomes derived from a permanently growing MSC line on both, wild type and ALS (SOD1G93A transgenic) primary motor neurons. Following application in a normal and stressed environment we could demonstrate beneficial effects of MSC exosomes on neurite growth and morphology indicating the potential for further preclinical evaluation and clinical therapeutic development. Investigation of gene expression profiles detected transcripts of several antioxidant and anti-inflammatory genes in MSC exosomes. Characterization of their microRNA (miRNA) content revealed miRNAs capable of regulating antioxidant and anti-apoptotic pathways.

Study on the Function and Mechanism of miR-585-3p Inhibiting the Progression of Ovarian Cancer Cells by Targeting FSCN1 to Block the MAPK Signaling Pathway.

Ovarian cancer (OC) is the leading cause of death for women diagnosed with gynecological cancer. Studies have shown that dysregulated miRNA expression is related to various cancers, including OC. Here, we aimed to explore the biological function and mechanism of miR-585-3p in the occurrence and development of OC. The expression level of miR-585-3p was found to be low in OC tissues and cells. We analyzed the biological function of miR-585-3p in OC through in vitro cell experiments. The results indicated that overexpression of miR-585-3p inhibited the proliferation, invasion, and migration of SW626 cells, while low expression of miR-585-3p had the opposite effect in SKOV3 cells. We then screened the target genes of miR-585-3p through miRDB database and detected the expression of target genes in OC cells. FSCN1 was found to be most significantly upregulated in OC cells. Dual-luciferase reporter assays revealed FSCN1 as a potential target of miR-585-3p. Western blot analysis showed that miR-585-3p targeted FSCN1 to inhibit protein phosphorylation of ERK. In vivo animal experiments also confirmed that miR-585-3p targets FSCN1 to inhibit tumor growth and block the MAPK signaling pathway. In summary, miR-585-3p inhibits the proliferation, migration, and invasion of OC cells by targeting FSCN1, and its mechanism of action may be achieved by inhibiting the activation of the MAPK signaling pathway. miR-585-3p may serve as a potential biomarker and therapeutic target for OC.

Human MSC-Derived Exosomes Reduce Cellular Senescence in Renal Epithelial Cells.

Cellular senescence of renal tubular cells is associated with chronic diseases and age-related kidney disorders. Therapies to antagonize senescence are, therefore, explored as novel approaches in nephropathy. Exosomes derived from human mesenchymal stroma-/stem-like cells (MSC) entail the transfer of multiple bioactive molecules, exhibiting profound regenerative potential in various tissues, including therapeutic effects in kidney diseases. Here, we first demonstrate that exosomes promote proliferation and reduce senescence in aged MSC cultures. For potential therapeutic perspectives in organ rejuvenation, we used MSC-derived exosomes to antagonize senescence in murine kidney primary tubular epithelial cells (PTEC). Exosome treatment efficiently reduced senescence while diminishing the transcription of senescence markers and senescence-associated secretory phenotype (SASP) factors. Concomitantly, we observed less DNA damage foci and more proliferating cells. These data provide new information regarding the therapeutic property of MSC exosomes in the development of renal senescence, suggesting a contribution to a new chapter of regenerative vehicles in senotherapy.

Cell-Cell Fusion Mediated by Viruses and HERV-Derived Fusogens in Cancer Initiation and Progression.

Cell fusion is a well-known, but still scarcely understood biological phenomenon, which might play a role in cancer initiation, progression and formation of metastases. Although the merging of two (cancer) cells appears simple, the entire process is highly complex, energy-dependent and tightly regulated. Among cell fusion-inducing and -regulating factors, so-called fusogens have been identified as a specific type of proteins that are indispensable for overcoming fusion-associated energetic barriers and final merging of plasma membranes. About 8% of the human genome is of retroviral origin and some well-known fusogens, such as syncytin-1, are expressed by human (cancer) cells. Likewise, enveloped viruses can enable and facilitate cell fusion due to evolutionarily optimized fusogens, and are also capable to induce bi- and multinucleation underlining their fusion capacity. Moreover, multinucleated giant cancer cells have been found in tumors derived from oncogenic viruses. Accordingly, a potential correlation between viruses and fusogens of human endogenous retroviral origin in cancer cell fusion will be summarized in this review.

MSC-Derived Extracellular Vesicles in Tumors and Therapy.

Exosomes derived from mesenchymal stroma-/stem-like cells (MSCs) as part of extracellular vesicles are considered cell-free biocompatible nanovesicles that promote repair activities of damaged tissues or organs by exhibiting low immunogenic and cytotoxic effects. Contributions to regenerative activities include wound healing, maintenance of stem cell niches, beneficial regenerative effects in various diseases, and reduction of senescence. However, the mode of action in MSC-derived exosomes strongly depends on the biological content like different regulatory microRNAs that are determined by the tissue origin of MSCs. In tumors, MSCs use indirect and direct pathways in a communication network to interact with cancer cells. This leads to mutual functional changes with the acquisition of an aberrant tumor-associated MSC phenotype accompanied by altered cargo in the exosomes. Consequently, MSC-derived exosomes either from normal tissue-originating MSCs or from aberrant tumor-associated MSCs can confer different actions on tumor development. These processes exhibiting tumor-inhibitory and tumor-supportive effects with a focus on exosome microRNA content will be discriminated and discussed within this review.

Spontaneous Fusion of MSC with Breast Cancer Cells Can Generate Tumor Dormancy.

Direct cellular interactions of MDA-MB-231cherry breast cancer cells with GFP-transduced human mesenchymal stroma/stem-like cells (MSCGFP) in a co-culture model resulted in spontaneous cell fusion by the generation of MDA-MSC-hyb5cherry GFP breast cancer hybrid cells. The proliferative capacity of MDA-MSC-hyb5 cells was enhanced about 1.8-fold when compared to the parental MDA-MB-231cherry breast cancer cells. In contrast to a spontaneous MDA-MB-231cherry induced tumor development in vivo within 18.8 days, the MDA-MSC-hyb5 cells initially remained quiescent in a dormancy-like state. At distinct time points after injection, NODscid mice started to develop MDA-MSC-hyb5 cell-induced tumors up to about a half year later. Following tumor initiation, however, tumor growth and formation of metastases in various different organs occurred rapidly within about 10.5 days. Changes in gene expression levels were evaluated by RNA-microarray analysis and revealed certain increase in dormancy-associated transcripts in MDA-MSC-hyb5. Chemotherapeutic responsiveness of MDA-MSC-hyb5 cells was partially enhanced when compared to MDA-MB-231 cells. However, some resistance, e.g., for taxol was detectable in cancer hybrid cells. Moreover, drug response partially changed during the tumor development of MDA-MSC-hyb5 cells; this suggests the presence of unstable in vivo phenotypes of MDA-hyb5 cells with increased tumor heterogeneity.

Genomic characterization of Chinese ovarian clear cell carcinoma identifies driver genes by whole exome sequencing.

Little is known about the genetic alterations characteristic of ovarian clear cell carcinoma (OCCC). Our aim was to identify targetable genomic alterations in this type of cancer. Forty-two OCCC formalin-fixed, paraffin-embedded (FFPE) tissue samples were analyzed by whole-exome sequencing (WES), and 74 FFPE tissue samples underwent targeted sequencing (TS) to confirm the relevant driver mutations. Cell proliferation was assessed by cell counting kit-8 (CCK8) assays. In the 42 samples, ARID1A (64.3%) and PIK3CA (28.5%) were frequently mutated, as were PPP2R1A (11.9%), PTEN (7.1%) and KRAS (4.8%), which have been reported in previous OCCC studies. We also detected mutations in MUC4 (28.6%), MAGEE1 (19%), and ARID3A (16.7%); associations with these genes have not been previously reported. The functional protein-activated pathways were associated with proliferation and survival (including the PI3K/AKT, TP53, and ERBB2 pathways) in 83% of OCCCs and with chromatin remodeling in 71% of OCCCs. Patients with alterations in MAGEE1 (64% in the targeted sequencing cohort) had worse clinical outcomes (log-rank p < 0.05). A functional study revealed that two MAGEE1 mutants, one lacking two MAGE domains and the other containing two MAGE domains, significantly decreased the proliferative capacity of OCCC cells. We successfully identified novel genetic alterations in OCCC using whole-exome sequencing and targeted sequencing of OCCC patient samples and potential therapeutic targets for the treatment of this malignancy.

E6/E7-P53-POU2F1-CTHRC1 axis promotes cervical cancer metastasis and activates Wnt/PCP pathway.

Cervical cancer is an infectious cancer and the most common gynecologic cancer worldwide. E6/E7, the early genes of the high-risk mucosal human papillomavirus type, play key roles in the carcinogenic process of cervical cancer. However, little was known about its roles in modulating tumor microenvironment, particular extracellular matrix (ECM). In this study, we found that E6/E7 could regulate multiple ECM proteins, especially collagen triple helix repeat containing 1 (CTHRC1). CTHRC1 is highly expressed in cervical cancer tissue and serum and closely correlated with clinicopathological parameters. CTHRC1 promotes cervical cancer cell migration and invasion in vitro and metastasis in vivo. E6/E7 regulates the expression of CTHRC1 in cervical cancer by E6/E7-p53-POU2F1 (POU class 2 homeobox 1) axis. Futhermore, CTHRC1 activates Wnt/PCP signaling pathway. Take together, E6/E7-p53-POU2F1-CTHRC1 axis promotes cervical cancer cell invasion and metastasis and may act as a potential therapeutic target for interventions against cervical cancer invasion and metastasis.