Inhibition of the met receptor tyrosine kinase signaling enhances the chemosensitivity of glioma cell lines to CDDP through activation of p38 MAPK pathway.
The Met receptor tyrosine kinase is known to be overexpressed in many solid tumors and plays a crucial role in tumor invasive growth and metastasis. In this study, we showed that hepatocyte growth factor-induced Met activation as well as Met-dependent downstream signaling of AKT and p44/42 mitogen-activated protein kinase (MAPK) could be efficiently blocked by TAT-coupled carboxyl-terminal tail peptide of Met receptor (TCTP), and inactivation of Met signaling significantly enhanced the sensitivity of T98G and U251 glioma cells to cis-diaminedichloroplatinum (CDDP, cisplatin). However, neither phosphoinositide 3-kinase/AKT inhibitor LY294002 nor p44/42 MAPK inhibitor PD98059 alone or combined could imitate the effect of TCTP on chemosensitivity enhancement of T98G cells to CDDP, indicating that Met-dependent inactivation of AKT and p44/42 MAPK signaling was not the main cause for the increased chemosensitivity to CDDP. Further studies revealed that TCTP significantly activated p38 MAPK in T98G and U251 cell lines. Activation of p38 MAPK by sorbitol pretreatment resembled the sensitization effects, whereas inhibition of p38 MAPK activation by its inhibitor SB202190 counteracted the sensitization effects induced by TCTP. Therefore, p38 MAPK activation was one of the major causes for the increased chemosensitivity to CDDP induced by Met inactivation. Taken together, the study indicated that Met receptor played an important role in regulating cell response to chemotherapy and suggested that inhibition of Met signaling could be used in combination with other chemotherapeutic regimens in treatment of tumor patients.
Lou
Xiuqin
X
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Tsinghua University, Beijing, People's Republic of China.
Zhou
Qibing
Q
Yin
Ying
Y
Zhou
Cheng
C
Shen
Yan
Y
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005910:Glioma / Q000473:pathology*; D017228:Hepatocyte Growth Factor / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D015398:Signal Transduction; D000090324:Tumor Protein, Translationally-Controlled 1; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D000970:Antineoplastic Agents; C066855:HGF protein, human; D010455:Peptides; C000715647:TPT1 protein, human; D000090324:Tumor Protein, Translationally-Controlled 1; D017228:Hepatocyte Growth Factor; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met; D051057:Proto-Oncogene Proteins c-akt; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D002945:Cisplatin