👤 Helmout Modjtahedi

Primary or acquired resistance to therapeutic agents is a major obstacle in the treatment of cancer patients. Cervical cancer is the fourth leading cause of cancer deaths among women worldwide and, despite major advances in cancer screening and treatments, many patients with advanced stage cervical cancer have a high recurrence rate within two years of standard treatment, with drug resistance being a major contributing factor. The development of cancer cell lines with acquired resistance to therapeutic agents can facilitate the comprehensive investigation of resistance mechanisms, which cannot be easily performed in clinical trials. This study aimed to create three novel and robust cervical cancer cell lines (HeLa, CaSki, and SiHa) with acquired resistance to a fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor (PD173074). All three drug-resistant (DR) cell lines overexpressed FGFR1, FGFR2, FGF2, FGF4, and FGF7 proteins that were also localized to the nucleus. In addition, the DR cells had a significantly more aggressive phenotype (more migratory and proliferative, less apoptotic) compared to the parental cell lines. These novel DR cervical cancer cells are a critical tool for understanding the molecular mechanisms underpinning drug resistance and for the identification of potential cervical cancer biomarkers. Moreover, the availability of such DR cell lines may facilitate the development of more effective therapeutic strategies using FGFR inhibitors in combination with other agents that target pathways responsible for acquired resistance to FGFR inhibitors. Show less

Aberrant expression and activation of epidermal growth factor receptor (EGFR) resulted in approval of several forms of EGFR inhibitors in the treatment of patients with a wide range of epithelial cancers. However, no EGFR inhibitor has yet been approved for the treatment of patients with brain cancer, indicating that targeting EGFR alone may not be sufficient in some patients. In this study, we investigated the role of all members of the EGFR family, other growth factor receptors, cell-cycle proteins, and downstream cell signaling pathways (e.g., mitogen-activated protein kinase (MAPK), serine/threonine protein kinase (AKT), signal transducer and activator of transcription (STAT3), Src, Abelson murine leukemia viral oncogene homolog (Abl)) on the growth of a panel of human brain cancer cell lines (HBCCLs). We examined the growth response of HBCCLs to treatment with 17 targeted agents compared to two cytotoxic drugs. Of the targeted agents, the irreversible pan-human epidermal growth factor receptor (HER) inhibitors neratinib and afatinib were more effective than erlotinib and lapatinib at inhibiting the growth of all HBCCLs, and the cyclin-dependent kinase (CDK)1/2/5/9 inhibitor dinaciclib was the most potent targeted agent. We found that treatment with Src/Abl/c-kit inhibitor dasatinib, signal transducer and activator of transcription (STAT3) inhibitor stattic, Abl/platelet-derived growth factor receptor (PDGFR)α/vascular endothelial growth factor (VEGFR)2/fibroblast growth factor receptor (FGFR)1 inhibitor ponatinib, and the tropomyosin receptor kinase (TRK)/ROS proto-oncogene 1 receptor tyrosine kinase (ROS)/anaplastic lymphoma kinase (ALK) inhibitor entrectinib, also inhibited the growth of all HBCCLs. Interestingly, these agents were more effective in inhibiting growth of HBCCLs when proliferating at a slower rate. In addition to inhibiting the proliferation of HBCCLs, treatment with neratinib, dinaciclib, dasatinib, stattic and trametinib inhibited the migration of brain tumor cell line A172. Notably, we found that treatment with neratinib in combination with palbociclib (CDK4/6 inhibitor), or miransertib (AKT1/2/3 inhibitor) resulted in synergistic growth inhibition of all HBCCLs. Our results support that repurposing drugs like neratinib in combination with the palbociclib or miransertib may be of therapeutic potential in brain cancer and warrants further investigations. Show less