Physical Intimacy of Breast Cancer Cells with Mesenchymal Stem Cells Elicits Trastuzumab Resistance through Src Activation.
The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors. Here, we demonstrate that the physical contact of breast cancer cells with mesenchymal stem cells (MSCs) is a potential modulator of trastuzumab response by activation of nonreceptor tyrosine kinase c-Src and down regulation of phosphatase and tensin homolog (PTEN). Using an in vitro patterned breast cancer/MSC co-culture model, we find that the presence of MSCs results in Src activation that is missing in cancer cells monoculture, transwell co-culture, and cells treated with MSCs conditioned media. Interestingly, the co-culture model also results in PTEN loss and activation of PI3K/AKT pathway that has been demonstrated as fundamental proliferative and survival pathways in clinical settings. To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs. In addition, breast cancer cells in co-culture with MSCs conferred trastuzumab resistance in vitro as observed in the lack of inhibition of proliferative and migrative properties of the cancer cells. Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.
Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE, 68588.
Amita
A
Daverey
Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE, 68588.
Allison P
AP
Drain
Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE, 68588.|Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, NE, 68588.|Mary and Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, NE, 68198.
Srivatsan
S
Kidambi
D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002450:Cell Communication; D002478:Cells, Cultured; D018920:Coculture Techniques; D019008:Drug Resistance, Neoplasm; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D008954:Models, Biological; D015398:Signal Transduction; D000068878:Trastuzumab / Q000494:pharmacology*; D019061:src-Family Kinases / Q000378:metabolism*
D000970:Antineoplastic Agents; D019061:src-Family Kinases; D000068878:Trastuzumab