EGFR/Notch Antagonists Enhance the Response to Inhibitors of the PI3K-Akt Pathway by Decreasing Tumor-Initiating Cell Frequency

Autor: Shi Hu, Ying Tang, Yue Yu, Wenyan Fu, Xuting Ye, Min Ding, Shuowu Liu, Yongji Yang, Fangxing Lin, Xiaoyan Fan, Changhai Lei, Tian Li, Yafeng Shen
Rok vydání: 2019
Předmět:
0301 basic medicine
Cancer Research
Indazoles
Cell
Notch signaling pathway
Mice
Nude

Apoptosis
Triple Negative Breast Neoplasms
Mice
SCID

Mice
Phosphatidylinositol 3-Kinases
03 medical and health sciences
0302 clinical medicine
Mice
Inbred NOD

Cancer stem cell
Antibodies
Bispecific

Antineoplastic Combined Chemotherapy Protocols
Biomarkers
Tumor

Tumor Cells
Cultured

medicine
Animals
Humans
Tarextumab
PI3K/AKT/mTOR pathway
Cell Proliferation
EGFR inhibitors
Mice
Inbred BALB C

Sulfonamides
Receptors
Notch

Cell growth
business.industry
Prognosis
Xenograft Model Antitumor Assays
ErbB Receptors
Gene Expression Regulation
Neoplastic

030104 developmental biology
medicine.anatomical_structure
Oncology
030220 oncology & carcinogenesis
Neoplastic Stem Cells
Cancer research
Signal transduction
business
Proto-Oncogene Proteins c-akt
Zdroj: Clinical Cancer Research. 25:2835-2847
ISSN: 1557-3265
1078-0432
Popis: Purpose: Both EGFR and PI3K-Akt signaling pathways have been used as therapeutically actionable targets, but resistance is frequently reported. In this report, we show that enrichment of the cancer stem cell (CSC) subsets and dysregulation of Notch signaling underlie the challenges to therapy and describe the development of bispecific antibodies targeting both HER and Notch signaling. Experimental Design: We utilized cell-based models to study Notch signaling in drug-induced CSC expansion. Both cancer cell line models and patient-derived xenograft tumors were used to evaluate the antitumor effects of bispecific antibodies. Cell assays, flow cytometry, qPCR, and in vivo serial transplantation assays were employed to investigate the mechanisms of action and pharmacodynamic readouts. Results: We found that EGFR/Notch targeting bispecific antibodies exhibited a notable antistem cell effect in both in vitro and in vivo assays. Bispecific antibodies delayed the occurrence of acquired resistance to EGFR inhibitors in triple-negative breast cancer cell line–based models and showed efficacy in patient-derived xenografts. Moreover, the EGFR/Notch bispecific antibody PTG12 in combination with GDC-0941 exerted a stronger antitumor effect than the combined therapy of PI3K inhibitor with EGFR inhibitors or tarextumab in a broad spectrum of epithelial tumors. Mechanistically, bispecific antibody treatment inhibits the stem cell–like subpopulation, reduces tumor-initiating cell frequency, and downregulates the mesenchymal gene expression. Conclusions: These findings suggest that the coblockade of EGFR and Notch signaling has the potential to increase the response to PI3K inhibition, and PTG12 may gain clinical efficacy when combined with PI3K blockage in cancer treatment.
Databáze: OpenAIRE