MicroRNA and target mRNA selection through invasion and cytotoxicity cell modeling and bioinformatics approaches in esophageal squamous cell carcinoma

Characterization of plasma exosomal microRNAs in responding to radiotherapy of human esophageal squamous cell carcinoma

Radiotherapy is one of the main treatment methods for esophageal squamous cell carcinoma (ESCC). Previous research has shown that plasma exosomal microRNAs (miRNAs) can predict therapeutic outcome. In the present study, to identify potential exosomal miRNAs that respond to radiotherapy, plasma exosomal miRNAs from ESCC patients undergoing radiotherapy were isolated and sequenced. Upregulated and downregulated miRNAs were detected from patients pre- and post-radiotherapy, and it was found that they play distinct roles in DNA damage process and endosomal mediated transport. Based on wound healing and Cell Counting Kit-8 assays in TE-1 human esophageal cancer cells, it was identified that representative miRNA miR-652 and miR-30a alter migration but not proliferation. The present findings identified differentially expressed miRNAs in responding to radiotherapy, and added a reference to explore non-invasive plasma biomarkers to evaluate therapeutic effects in ESCC.

Novel Combinatorial MicroRNA-Binding Sites in AAV Vectors Synergistically Diminish Antigen Presentation and Transgene Immunity for Efficient and Stable Transduction

Recombinant adeno-associated virus (rAAV) platforms hold promise for in vivo gene therapy but are undermined by the undesirable transduction of antigen presenting cells (APCs), which in turn can trigger host immunity towards rAAV-expressed transgene products. In light of recent adverse events in patients receiving high systemic AAV vector doses that were speculated to be related to host immune responses, development of strategies to mute innate and adaptive immunity is imperative. The use of miRNA binding sites (miR-BSs) to confer endogenous miRNA-mediated regulation to detarget transgene expression from APCs has shown promise for reducing transgene immunity. Studies have shown that designing miR-142BSs into rAAV1 vectors were able to repress costimulatory signals in dendritic cells (DCs), blunt the cytotoxic T cell response, and attenuate clearance of transduced muscle cells in mice to allow sustained transgene expression in myofibers with negligible anti-transgene IgG production. In this study, we screened individual and combinatorial miR-BS designs against 26 miRNAs that are abundantly expressed in APCs, but not in skeletal muscle. The highly immunogenic ovalbumin (OVA) transgene was used as a proxy for foreign antigens. In vitro screening in myoblasts, mouse DCs, and macrophages revealed that the combination of miR-142BS and miR-652-5pBS strongly mutes transgene expression in APCs but maintains high myoblast and myocyte expression. Importantly, rAAV1 vectors carrying this novel miR-142/652-5pBS cassette achieve higher transgene levels following intramuscular injections in mice than previous detargeting designs. The cassette strongly inhibits cytotoxic CTL activation and suppresses the Th17 response in vivo. Our approach, thus, advances the efficiency of miRNA-mediated detargeting to achieve synergistic reduction of transgene-specific immune responses and the development of safe and efficient delivery vehicles for gene therapy.

Expression, function and clinical application of stanniocalcin-1 in cancer

The glycoprotein stanniocalcin-1 functions as a regulatory endocrine hormone that maintains the balance of calcium and phosphorus in bony fish and as a paracrine/autocrine factor involved in many physiological/pathological processes in humans, including carcinogenesis. In this review, we provide an overview of (a) the possible mechanisms through which STC1 affects the malignant properties of cancer, (b) transcriptional and post-transcriptional regulation pathways of STC1 and (c) the potential clinical relevance of STC1 as a cancer biomarker and even a therapeutic target in the future. Exploring the role of STC1 in cancer development may provide a better understanding of the tumorigenesis process in humans and may facilitate finding an effective therapeutic method against cancer.

miR-146b Regulates Cell Proliferation and Apoptosis in Gastric Cancer by Targeting PTP1B

BACKGROUND/AIMS

The purpose of this study is to explore the inhibition or activation effects of microRNA-146 B on the expression of PTP1B in gastric cancer cells.

METHODS

The expressions of PTP1B and miR-146b in gastric cancer were detected by RT-qPCR. The effects of miR-146b on cell apoptosis and proliferation of gastric cancer were detected. The methods used in the detection process included Annexin V/PI dying method, colony formation assay, and MTT assay. The downstream target gene miR-146b was predicted and screened by bioinformatics and luciferase reporter assay. The mRNA and protein expressions of the target gene PTP1B miR-146b were determined using RT-qPCR and western blot. The expression of miR-146 B in mice was detected by the cells transfected with microRNA-146 B in vivo.

RESULTS

Compared with normal tissues, PTP1B was higher and miR-146b was lower in cancer cells. Over-expression of miR-146b can inhibit cell viability and increase the apoptosis rate. According to the luciferase reporter assay, PTP1B was the downstream target gene of miR-146b. The re-introduction of PTP1B reversed the growth inhibition and apoptosis of gastric cancer cells induced by miR-146b. From the mouse xenograft model, the over-expression of miR-146b inhibited the tumor growth and reduced the expression level of PTP1B.

CONCLUSION

miR-146b directly inhibits the expression of PTP1B and suppressed the growth and development of gastric cancer.

LncRNA-TUSC7/miR-224 affected chemotherapy resistance of esophageal squamous cell carcinoma by competitively regulating DESC1

BACKGROUND

This study aims to clarify the underlying mechanism for the tumor suppressive function of lnc TUSC7 in chemotherapy resistance of esophageal squamous cell carcinoma (ESCC).

METHODS

TUSC7, miR-224 and DESC1 expressions in ESCC tissues and cells were detected by qRT-PCR. Protein level of DESC1, EGFR and p-AKT were observed by Western blot. Overall survival was calculated using the Kaplan-Meier method. Dual-luciferase reporter gene assay and RIP assay were used to comfirm TUSC7 binding to miR-224, and miR-224 binding to DESC1. Cell proliferation, apoptosis, and colony formation was detected by MTT, Flow Cytometry and Colony formation assays.

RESULTS

TUSC7 was downregulated in ESCC tissues and cells, and low TUSC7 indicated worse overall survival. The analysis of bioinformatics softwares showed that TUSC7 specifically bound to miR-224, and we proved miR-224 was upregulated in ESCC and negatively correlated with TUSC7 expression. Overexpression of TUSC7/inhibition of miR-224 suppressed cell proliferation, colony formation and chemotherapy resistance of ESCC cells, and promoted cell apoptosis. In addition, we confirmed that miR-224 specifically bound to DESC1, and negatively correlated with DESC1. TUSC7 suppressed the proliferation and chemotherapy resistance of ESCC cells by increasing DESC1 expression via inhibiting miR-224. We also confirmed DESC1 inhibited chemotherapy resistance of ESCC cells via EGFR/AKT. Finally, in vivo experiments demonstrated that overexpression of TUSC7 decreased tumor growth and chemotherapy resistance.

CONCLUSION

These findings suggested TUSC7 suppressed chemotherapy resistance of ESCC by downregulating miR-224 to modulate DESC1/EGFR/AKT pathway.