Silencing RPL9 promotes malignant proliferation in breast cancer cells.

Area of Science:

• Oncology
• Molecular Biology
• Bioinformatics

Background:

• Breast cancer (BRCA) is a heterogeneous malignancy where posttranscriptional dysregulation impacts tumor progression.
• RNA-binding proteins (RBPs) are crucial regulators of RNA metabolism and emerging biomarkers in BRCA.

Purpose of the Study:

• To identify key RBPs for BRCA prognosis.
• To develop an RBP-based prognostic scoring model and clinical nomogram.
• To investigate the functional role of RPL9 in BRCA cell proliferation and apoptosis.

Main Methods:

• Utilized TCGA RNA-sequencing data and clinical information for BRCA patients.
• Employed differential expression, Cox, and LASSO regression for RBP identification and risk model construction.
• Performed functional assays (CCK-8, flow cytometry) to assess RPL9's role in BRCA cells.

Main Results:

• Identified nine prognosis-related RBPs, constructing a validated prognostic scoring model and a clinical nomogram.
• High-risk BRCA patients showed higher tumor mutational burden (TMB) and altered tumor immune microenvironment (TIME).
• RPL9 was downregulated in BRCA, and its overexpression suppressed proliferation and increased apoptosis, indicating a tumor-suppressive function.

Conclusions:

• Developed a 9-RBP scoring model and nomogram for accurate BRCA survival prediction and TME assessment.
• Established RPL9 downregulation as a marker of poor prognosis in BRCA.
• RPL9 is a potential therapeutic target and prognostic biomarker for breast cancer.