[Methylation Status of the SOCS3 Gene Promoter in H2228 Cells and  EML4-ALK-positive Lung Cancer Tissues].
BACKGROUND
The EML4-ALK fusion gene is a newly discovered driver gene of non-small cell lung cancer and exhibits special clinical and pathological features. The JAK-STAT signaling pathway, an important downstream signaling pathway of EML4-ALK, is aberrantly sustained and activated in EML4-ALK-positive lung cancer cells fusion gene, but the underlying reason remains unknown. The suppressor of cytokine signaling (SOCS) is a negative regulatory factor that mainly inhibits the proliferation, differentiation, and induction of apoptotic cells by inhibiting the JAK-STAT signaling pathway. The aberrant methylation of the SOCS gene leads to inactivation of tumors and abnormal activation of the JAK2-STAT signaling pathway. The aim of this study is to investigate the methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 cells and lung cancer tissues.


METHODS
The methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 lung cancer cells and lung cancer tissues was detected by methylation-specific PCR (MSP) analysis and verified by DNA sequencing. The expression levels of SOCS3 in H2228 cells were detected by Western blot and Real-time PCR analyses after treatment with the DNA methyltransferase inhibitor 5'-Aza-dC.


RESULTS
MSP and DNA sequencing assay results indicated the presence of SOCS3 promoter methylation in H2228 cells as well as in three cases of seven EML4-ALK-positive lung cancer tissues. The expression level of SOCS3 significantly increased in H2228 cells after 5'-Aza-dC treatment.


CONCLUSIONS
The aerrant methylation of the SOCS3 promoter region in EML4-ALK (+) H2228 cells and lung cancer tissues may be significantly involved in the pathogenesis of EML4-ALK-positive lung cancer.
Department of Lung Cancer Surgery, Tianjin Medical University General Hospital, Tianjin 300052, China.
Chunlai
C
Liu
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Yongwen
Y
Li
Department of Lung Cancer Surgery, Tianjin Medical University General Hospital, Tianjin 300052, China.
Yunlong
Y
Dong
Department of Lung Cancer Surgery, Tianjin Medical University General Hospital, Tianjin 300052, China.
Hongbing
H
Zhang
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Ying
Y
Li
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Hongyu
H
Liu
Department of Lung Cancer Surgery;Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Jun
J
Chen
D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019175:DNA Methylation; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism; D008745:Methylation; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D000071223:Suppressor of Cytokine Signaling 3 Protein / Q000235:genetics* / Q000378:metabolism
C522504:EML4-ALK fusion protein, human; D015514:Oncogene Proteins, Fusion; C106644:SOCS3 protein, human; D000071223:Suppressor of Cytokine Signaling 3 Protein
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