Oncogenic RAS Regulates Long Noncoding RNA Orilnc1 in Human Cancer

Area of Science:

• Molecular Biology
• Oncology
• Genetics

Background:

• RAS signaling pathways regulate cell growth and division.
• While protein-coding targets are known, RAS-regulated long noncoding RNAs (lncRNAs) are less understood.

Purpose of the Study:

• Identify novel lncRNAs regulated by RAS signaling.
• Investigate the role of identified lncRNAs in RAS-driven oncogenesis.

Main Methods:

• Utilized a custom lncRNA microarray to screen for RAS-regulated lncRNAs.
• Investigated the regulatory mechanism of Orilnc1 expression via RAS-RAF-MEK-ERK signaling and AP1.
• Assessed the functional impact of Orilnc1 silencing on tumor cell proliferation and cell cycle progression in vitro and in vivo.

Main Results:

• Identified Orilnc1 as a novel genetic target of RAS signaling.
• Demonstrated that Orilnc1 expression is regulated by the RAS-RAF-MEK-ERK pathway via AP1.
• Observed high Orilnc1 expression in BRAF-mutant cancers like melanoma.
• Showed that Orilnc1 silencing inhibits tumor cell proliferation and growth.
• Found that Orilnc1 blockade reduces cyclin E1 expression and induces G1-S cell-cycle arrest.

Conclusions:

• Orilnc1 is a critical mediator of RAS oncogenicity.
• Orilnc1 functions as a nonprotein effector of RAS/RAF activation.
• Orilnc1 represents a potential therapeutic target for cancers driven by RAS/RAF mutations.