Epigenetic silencing of the non-coding RNA nc886 provokes oncogenes during human esophageal tumorigenesis

Area of Science:

• Molecular Biology
• Oncology
• Epigenetics

Background:

• nc886 (vtRNA2-1/pre-miR-886) is a noncoding RNA interacting with Protein Kinase RNA-activated (PKR).
• Previous suggestions of nc886 as a tumor suppressor were based on expression patterns and genomic location.

Purpose of the Study:

• To investigate the role of nc886 as a tumor suppressor in esophageal squamous cell carcinoma (ESCC).
• To elucidate the regulatory mechanisms of nc886 expression and its impact on oncogenesis in ESCC.

Main Methods:

• Analysis of nc886 expression in 84 paired ESCC tumor and adjacent normal tissues.
• Correlation analysis between nc886 expression, patient survival, and promoter methylation status.
• In vitro studies involving nc886 knockdown and ectopic expression in ESCC cells.

Main Results:

• nc886 expression was significantly lower in ESCC tumors compared to normal tissues.
• Reduced nc886 expression correlated with shorter recurrence-free survival in ESCC patients.
• nc886 promoter hypermethylation was identified as a mechanism for its suppression, leading to increased FOS, MYC, and NF-κB activity.
• Ectopic expression of nc886 inhibited ESCC cell proliferation.

Conclusions:

• nc886 functions as a novel, putative tumor suppressor in ESCC.
• Epigenetic silencing via promoter hypermethylation contributes to nc886 downregulation in ESCC.
• nc886 regulates oncogene and inflammatory gene expression, highlighting its role in ESCC development.