Targeting RLIP with CRISPR/Cas9 controls tumor growth

Area of Science:

• Oncology
• Molecular Biology
• Gene Editing

Background:

• Breast cancer (BC) is a leading cause of cancer mortality in women, with over half of cases involving genetic defects in the p53 tumor suppressor gene.
• Ral-interacting protein (RLIP) is overexpressed in malignancy and helps BC cells survive p53 loss.
• The CRISPR/Cas9 system enables targeted gene editing by using a single-guide RNA (sgRNA) to direct the Cas9 enzyme to a specific DNA sequence.

Purpose of the Study:

• To investigate the efficacy of targeting the RLIP gene using CRISPR/Cas9 technology in breast cancer cells.
• To assess the impact of RLIP gene disruption on breast cancer cell survival, proliferation, and tumorigenicity in vitro and in vivo.

Main Methods:

• CRISPR/Cas9 technology was employed to target the RLIP gene in breast cancer cells.
• Single-guide RNAs (sgRNAs) were screened using a reporter system and delivered lentivirally with Cas9.
• The effects of RLIP knockdown on cell proliferation, tumor growth, and expression of key molecular markers were evaluated in vitro and in vivo.

Main Results:

• CRISPR-mediated disruption of the RLIP gene significantly inhibited breast cancer cell proliferation both in vitro and in vivo.
• Resected tumors showed decreased levels of proliferation markers (Ki67, pAkt, survivin, CDK4), RLIP, and mesenchymal markers (vimentin).
• Elevated levels of differentiation (E-cadherin) and pro-apoptotic (Bim) markers were observed, while BC cells without doxycycline treatment showed no significant changes.

Conclusions:

• The CRISPR/Cas9 system provides a viable tool for targeting the RLIP gene in breast cancer.
• Disrupting RLIP demonstrates potential as a therapeutic strategy to inhibit breast cancer progression, particularly in p53-deficient tumors.