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Updated: Jun 18, 2026
Pooled CRISPR-Based Genetic Screens in Mammalian Cells
Published on: September 4, 2019
Genome-wide CRISPR screen identifies synthetic lethality between DOCK1 inhibition and metformin in liver cancer
Junru Feng1,2, Hui Lu1,2, Wenhao Ma2
1Anhui Key Laboratory of Hepatopancreatobiliary Surgery, Department of General Surgery, Anhui Provincial Hospital, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, 230027, China.
Abstract:
Metformin is currently a strong candidate anti-tumor agent in multiple cancers. However, its anti-tumor effectiveness varies among different cancers or subpopulations, potentially due to tumor heterogeneity. It thus remains unclear which hepatocellular carcinoma (HCC) patient subpopulation(s) can benefit from metformin treatment. Here, through a genome-wide CRISPR-Cas9-based knockout screen, we find that DOCK1 levels determine the anti-tumor effects of metformin and that DOCK1 is a synthetic lethal target of metformin in HCC. Mechanistically, metformin promotes DOCK1 phosphorylation, which activates RAC1 to facilitate cell survival, leading to metformin resistance. The DOCK1-selective inhibitor, TBOPP, potentiates anti-tumor activity by metformin in vitro in liver cancer cell lines and patient-derived HCC organoids, and in vivo in xenografted liver cancer cells and immunocompetent mouse liver cancer models. Notably, metformin improves overall survival of HCC patients with low DOCK1 levels but not among patients with high DOCK1 expression. This study shows that metformin effectiveness depends on DOCK1 levels and that combining metformin with DOCK1 inhibition may provide a promising personalized therapeutic strategy for metformin-resistant HCC patients.
Insights
Metformin
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Metformin shows potential as an anti-tumor agent across various cancers.
- Tumor heterogeneity influences metformin's effectiveness, leaving patient subpopulations unclear.
- Identifying specific hepatocellular carcinoma (HCC) patient groups benefiting from metformin is crucial.
Purpose of the Study:
- To identify biomarkers predicting metformin response in hepatocellular carcinoma (HCC).
- To elucidate the mechanism of metformin resistance in HCC.
- To evaluate combination therapy with metformin and DOCK1 inhibition.
Main Methods:
- Genome-wide CRISPR-Cas9 knockout screen to identify metformin resistance genes.
- In vitro and in vivo experiments using liver cancer cell lines, HCC organoids, and mouse models.
- Analysis of DOCK1 expression in HCC patient cohorts.
Main Results:
- DOCK1 levels dictate metformin's anti-tumor efficacy in HCC.
- Metformin promotes DOCK1 phosphorylation, activating RAC1 and conferring resistance.
- DOCK1 inhibition (TBOPP) synergizes with metformin to enhance anti-tumor activity.
- Metformin improved survival in HCC patients with low DOCK1 expression.
Conclusions:
- DOCK1 is a key determinant of metformin sensitivity in HCC.
- Combining metformin with DOCK1 inhibitors offers a personalized therapeutic strategy for metformin-resistant HCC.
- Targeting DOCK1 may overcome metformin resistance in liver cancer.
