The Role Of MenSC In Epigenetic Regulation Of Hepatocellular Carcinoma

Given their inflammation-and tumor-homing properties,MSCs have been considered as potential vehicles for cancer therapy that are able to target the sites of even microscopic tumors and metastasis.Although several clinical trials about cancer therapy with MSC have been reported,the clinical feasibility of MSCs for cancer therapy is hampered by a lack of sufficient understanding of the mechanisms of interaction between MSCs and cancer cells.Hence,a great deal of research is still needed to explore the role of MSCs in the reg?lation of cancer microenvironments before their safe application in human health care will be possible.The tumor microenvironment plays important roles in tumorigenesis,progression and drug resistance.Mesenchymal stem cells(MSCs),as one class of these surrounding cells,exert suppressive or promotive effects on cancers via multiple components of microenvironmental paracrine signaling.Epigenetic alteration is an important indicator of crosstalk between cancer cells and the surrounding microenvironment.These changes in genome adjusts dynamically in response to altered microenvironments,providing short-term memory of environmental stimuli or long-term inflammatory niche.However,the role of MSC in epigenetic reg?lation of cancer is still unknown.HCC is one of the cancers in which pathogenic processes intimately correlate with epigenetic dysregulation under long-term burdens of infection and chronic inflammation.Therefore,in this study,we aimed to investigate whether MenSCs affect epigenetic regulation in HCC and exert anticancer effects via specific epigenetic alterationsWe measured the anticancer effect of MenSCs on HCC via the transwell co-culture system and the tumor xenograft model in vitro and in vivo.Epigenetic alterations of HCC mediated by MenSCs were examined by immunofluorescence,clonogenic assay,ELISA and RT-PCR assays.The suppressive impact of MenSCs on HCC in vitro was investigated using CCK8,apoptosis,wound healing and invasion assays.Additionally,the inhibitory impact of MenSCs on HCC in vivo was conducted using the xenograft mice model.The growth of subcutaneous HCC was significantly inhibited after MenSCs therapy Moreover,the results of IHC assay further confirmed that MenSCs play a role in epigenetic reg?lation of HCC in vivoTo further clarify the complex mechanism of epigenetic alterations of HCC mediated by MenSCs,we performed MeDIP-seq,hMeDIP-seq and RNA-seq to identify the genome-wide pattern of DNA methylation and hydroxymethylation in HCC cells after MenSC therapy.We show for the first time that HCC displays distinct genome-wide alterations in DNA hydroxymethylation and methylation after MenSC therapy.MenSCs exert an inhibitory effect on HCC growth via reg?lating 5-hmC and 5-mC abundance in the reg?latory regions of oncogenic pathways including PI3K/AKT and MAPK signaling,especially in enhancers.Suppressor FOX03 expression is rescued via reversal of 5-hmC and 5-mC levels in its enhancers and contributes to the activation of downstream apoptosis.Inactivation of the MAPK pathway further disrupts c-myc mediated epithelial mesenchymal transitions(EMT).Additionally,chemotherapy-resistance associated genes including ID4 and HMGA1 are suppressed via amending 5-hmC and 5-mC abundance at their regulatory regions.HMGA1 and BYSL might be potential targets for gene-modified MSC therapyIn conclusion,our results demonstrate that MenSCs have a suppressive effect on the growth of HCC in vitro and vivo.Moreover,MenSCs play a role in epigenetic regulation of HCC in vitro and vivo.Furthermore,we confirm that MenSCs inhibit PI3K/AKT and MAPK signaling pathway via reg?lating the 5-hmC and 5-mC of promoter and enhancer regions.MSCs could regulate epigenetic mechanism of HCC cells and provide a novel concept for a modified MSC strategy or combination therapy with chemotherapeutics based on epigenetics.