About 15-20% of breast cancer (BCa) is triple-negative BCa (TNBC), a devastating disease with limited therapeutic options. Aberrations in the PI3K/PTEN signaling pathway are common in TNBC. However, the therapeutic impact of PI3K inhibitors in TNBC has been limited and the mechanism(s) underlying this lack of efficacy remain elusive. Here, we demonstrate that a large subset of TNBC expresses significant levels of MAPK4, and this expression is critical for driving AKT activation independent of PI3K and promoting TNBC cell and xenograft growth. The ability of MAPK4 to bypass PI3K for AKT activation potentially provides a direct mechanism regulating tumor sensitivity to PI3K inhibition. Accordingly, repressing MAPK4 greatly sensitizes TNBC cells and xenografts to PI3K blockade. Altogether, we conclude that high MAPK4 expression defines a large subset or subtype of TNBC responsive to MAPK4 blockage. Targeting MAPK4 in this subset/subtype of TNBC both represses growth and sensitizes tumors to PI3K blockade.
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http://dx.doi.org/10.1038/s41467-021-27921-1 | DOI Listing |
J Immunother Cancer
January 2025
Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
Background: Immune checkpoint inhibitors targeting programmed cell death protein-1 (PD-1) are the first line of treatment for many solid tumors including melanoma. PD-1 blockade enhances the effector functions of melanoma-infiltrating CD8 T cells, leading to durable tumor remissions. However, 55% of patients with melanoma do not respond to treatment.
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View Article and Find Full Text PDFJ Control Release
December 2024
Key Laboratory of Natural Medicine Innovation and Transformation, Henan University, Kaifeng 475000, PR China; State Key Laboratory of Antiviral Drugs, Henan University, Kaifeng 475000, PR China; Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100050, PR China. Electronic address:
Immunogenic cell death (ICD) has recently emerged as a promising strategy in reinforcing anti-PD-L1 blockade immunotherapy of triple-negative breast cancer (TNBC). The CDK4/6 inhibitor palbociclib (PAL), as a clinical star medicine targeting the cell cycle machinery, is an ideal candidate for fabricating a highly efficient ICD inducer for TNBC chemoimmunotherapy. However, the frequently observed chemoresistance and clinical adverse effects, as well as significant antagonistic effects when co-administered with certain chemotherapeutics, have seriously restricted the efficiency of PAL and the feasibility of combination strategies.
View Article and Find Full Text PDFCancer Treat Rev
January 2025
SOLTI Cancer Research Group, Barcelona, Spain; Statistics Unit, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain. Electronic address:
ACS Pharmacol Transl Sci
December 2024
Amity Institute of Integrative Sciences and Health, Amity University Haryana, Panchgaon, Manesar, Gurgaon-122413, Haryana, India.
The mechanistic target of rapamycin kinase (MTOR) is pivotal for cell growth, metabolism, and survival. It functions through two distinct complexes, mechanistic TORC1 and mechanistic TORC2 (mTORC1 and mTORC2). These complexes function in the development and progression of cancer by regulating different cellular processes, such as protein synthesis, lipid metabolism, and glucose homeostasis.
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