TY - JOUR
T1 - STAT3 and MITF cooperatively induce cellular transformation through upregulation of c-fos expression
AU - Joo, Akiko
AU - Aburatani, Hiroyuki
AU - Morii, Eiichi
AU - Iba, Hideo
AU - Yoshimura, Akihiko
N1 - Funding Information:
We thank Dr T Yoshida (Kurume University) for STAT3C-3T3, Dr Yonemitsu (Kyushu University) for melanoma cell lines, H Meguro for oligonucleotide microarray analysis, Y Kawabata for technical assistance, and N Arifuku for manuscript preparation. This work was supported by special grants-in-aid from the Ministry of Education, Science, Technology, Sports, and Culture of Japan, the Japan Health Science Foundation, the Human Frontier Science Program, the Japan Research Foundation for Clinical Pharmacology, Haraguchi Memorial foundation, and the Uehara Memorial Foundation. AJ is supported by the fellowship from Japan Society for Promotion of Science.
PY - 2004/1/22
Y1 - 2004/1/22
N2 - The signal transducer and activator of transcription (STAT) family proteins are transcription factors critical in mediating cytokine signaling. Among them, STAT3 is frequently activated in a number of human cancers and transformed cell lines and is implicated in tumorigenesis. However, although constitutively activated STAT3 mutant (STAT3C) leads to cellular transformation, its transformation potential such as colony-forming activity in soft-agar is much weaker than that of v-src. To identify tumorigenic factors that cooperatively induce cellular transformation with STAT3C, we screened the retroviral cDNA library. We found that the microphthalmia-associated transcription factor (MITF), an essential transcription factor for melanocyte development and pigmentation, induces anchorage-independent growth of NIH-3T3 cells in cooperation with STAT3C. Microarray analysis revealed that c-fos is highly expressed in transformants expressing STAT3C and MITF. Promoter analysis and chromatin immunoprecipitation assay suggested that both STAT3 and MITF can cooperatively upregulate the c-fos gene. In addition, the transformation of NIH-3T3 cells by both MITF and STAT3C was significantly suppressed by a dominant-negative AP-1 retrovirus. These data indicate that MITF and STAT3 cooperatively induce c-fos, resulting in cellular transformation.
AB - The signal transducer and activator of transcription (STAT) family proteins are transcription factors critical in mediating cytokine signaling. Among them, STAT3 is frequently activated in a number of human cancers and transformed cell lines and is implicated in tumorigenesis. However, although constitutively activated STAT3 mutant (STAT3C) leads to cellular transformation, its transformation potential such as colony-forming activity in soft-agar is much weaker than that of v-src. To identify tumorigenic factors that cooperatively induce cellular transformation with STAT3C, we screened the retroviral cDNA library. We found that the microphthalmia-associated transcription factor (MITF), an essential transcription factor for melanocyte development and pigmentation, induces anchorage-independent growth of NIH-3T3 cells in cooperation with STAT3C. Microarray analysis revealed that c-fos is highly expressed in transformants expressing STAT3C and MITF. Promoter analysis and chromatin immunoprecipitation assay suggested that both STAT3 and MITF can cooperatively upregulate the c-fos gene. In addition, the transformation of NIH-3T3 cells by both MITF and STAT3C was significantly suppressed by a dominant-negative AP-1 retrovirus. These data indicate that MITF and STAT3 cooperatively induce c-fos, resulting in cellular transformation.
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U2 - 10.1038/sj.onc.1207174
DO - 10.1038/sj.onc.1207174
M3 - Article
C2 - 14737107
AN - SCOPUS:1242318505
SN - 0950-9232
VL - 23
SP - 726
EP - 734
JO - Oncogene
JF - Oncogene
IS - 3
ER -
