In:
Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 19, No. 2 ( 2020-02-01), p. 614-626
Abstract:
Radiotherapy (RT) along with surgery is the mainstay of treatment in head and neck squamous cell carcinoma (HNSCC). Radioresistance represents a major source of treatment failure, underlining the urgent necessity to explore and implement effective radiosensitization strategies. The MET receptor widely participates in the acquisition and maintenance of an aggressive phenotype in HNSCC and modulates the DNA damage response following ionizing radiation (IR). Here, we assessed MET expression and mutation status in primary and metastatic lesions within a cohort of patients with advanced HNSCC. Moreover, we investigated the radiosensitization potential of the MET inhibitor tepotinib in a panel of cell lines, in vitro and in vivo, as well as in ex vivo patient-derived organotypic tissue cultures (OTC). MET was highly expressed in 62.4% of primary tumors and in 53.6% of lymph node metastases (LNM), and in 6 of 9 evaluated cell lines. MET expression in primaries and LNMs was significantly associated with decreased disease control in univariate survival analyses. Tepotinib abrogated MET phosphorylation and to distinct extent MET downstream signaling. Pretreatment with tepotinib resulted in variable radiosensitization, enhanced DNA damage, cell death, and G2–M-phase arrest. Combination of tepotinib with IR led to significant radiosensitization in one of two tested in vivo models. OTCs revealed differential patterns of response toward tepotinib, irradiation, and combination of both modalities. The molecular basis of tepotinib-mediated radiosensitization was studied by a CyTOF-based single-cell mass cytometry approach, which uncovered that MET inhibition modulated PI3K activity in cells radiosensitized by tepotinib but not in the resistant ones.
Type of Medium:
Online Resource
ISSN:
1535-7163
,
1538-8514
DOI:
10.1158/1535-7163.MCT-18-1274
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2020
detail.hit.zdb_id:
2062135-8
SSG:
12
