TY - JOUR
T1 - C-met inhibitor MK-8003 radiosensitizes c-met-expressing non-small-cell lung cancer cells with radiation-induced c-met-expression
AU - Bhardwaj, Vikas
AU - Zhan, Yanai
AU - Cortez, Maria Angelica
AU - Ang, Kie Kian
AU - Molkentine, David
AU - Munshi, Anupama
AU - Raju, Uma
AU - Komaki, Ritsuko
AU - Heymach, John V.
AU - Welsh, James
PY - 2012/8
Y1 - 2012/8
N2 - INTRODUCTION:: The radiation doses used to treat unresectable lung cancer are often limited by the proximity of normal tissues. Overexpression of c-Met, a receptor tyrosine kinase, occurs in about half of non-small-cell lung cancers (NSCLCs) and has been associated with resistance to radiation therapy and poor patient survival. We hypothesized that inhibiting c-Met would increase the sensitivity of NSCLC cells to radiation, enhancing the therapeutic ratio, which may potentially translate into improved local control. METHODS:: We tested the radiosensitivity of two high-c-Met-expressing NSCLC lines, EBC-1 and H1993, and two low-c-Met-expressing lines, A549 and H460, with and without the small-molecule c-Met inhibitor MK-8033. Proliferation and protein expression were measured with clonogenic survival assays and Western blotting, respectively. γ-H2AX levels were evaluated by immunofluorescence staining. RESULTS:: MK-8033 radiosensitized the high-c-Met-expressing EBC-1 and H1993 cells but not the low-c-Met-expressing cell lines A549 and H460. However, irradiation of A549 and H460 cells increased the expression of c-Met protein at 30 minutes after the irradiation. Subsequent targeting of this up-regulated c-Met by using MK-8033 followed by a second radiation dose reduced the clonogenic survival of both A549 and H460 cells. MK-8033 reduced the levels of radiation-induced phosphorylated (activated) c-Met in A549 cells. CONCLUSIONS:: These results suggest that inhibition of c-Met could be an effective strategy to radiosensitize NSCLC tumors with high basal c-Met expression or tumors that acquired resistance to radiation because of up-regulation of c-Met.
AB - INTRODUCTION:: The radiation doses used to treat unresectable lung cancer are often limited by the proximity of normal tissues. Overexpression of c-Met, a receptor tyrosine kinase, occurs in about half of non-small-cell lung cancers (NSCLCs) and has been associated with resistance to radiation therapy and poor patient survival. We hypothesized that inhibiting c-Met would increase the sensitivity of NSCLC cells to radiation, enhancing the therapeutic ratio, which may potentially translate into improved local control. METHODS:: We tested the radiosensitivity of two high-c-Met-expressing NSCLC lines, EBC-1 and H1993, and two low-c-Met-expressing lines, A549 and H460, with and without the small-molecule c-Met inhibitor MK-8033. Proliferation and protein expression were measured with clonogenic survival assays and Western blotting, respectively. γ-H2AX levels were evaluated by immunofluorescence staining. RESULTS:: MK-8033 radiosensitized the high-c-Met-expressing EBC-1 and H1993 cells but not the low-c-Met-expressing cell lines A549 and H460. However, irradiation of A549 and H460 cells increased the expression of c-Met protein at 30 minutes after the irradiation. Subsequent targeting of this up-regulated c-Met by using MK-8033 followed by a second radiation dose reduced the clonogenic survival of both A549 and H460 cells. MK-8033 reduced the levels of radiation-induced phosphorylated (activated) c-Met in A549 cells. CONCLUSIONS:: These results suggest that inhibition of c-Met could be an effective strategy to radiosensitize NSCLC tumors with high basal c-Met expression or tumors that acquired resistance to radiation because of up-regulation of c-Met.
KW - NSCLC
KW - Radiosensitivity
KW - c-Met
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U2 - 10.1097/JTO.0b013e318257cc89
DO - 10.1097/JTO.0b013e318257cc89
M3 - Article
C2 - 22617250
AN - SCOPUS:84863838764
SN - 1556-0864
VL - 7
SP - 1211
EP - 1217
JO - Journal of Thoracic Oncology
JF - Journal of Thoracic Oncology
IS - 8
ER -