Syntenin increases the invasiveness of small cell lung cancer cells by activating p38, AKT, focal adhesion kinase and SP1.
Syntenin is a PDZ domain-containing adaptor protein that has been recently shown to regulate migration and invasion in several tumors. Small cell lung cancer (SCLC) is notorious for its invasiveness and strong potential for metastasis. We therefore studied the influence of syntenin on the invasiveness of SCLC. Immunohistochemistry in tumor tissues showed that syntenin was more frequently expressed in small cell carcinomas than other neuroendocrine tumors, such as carcinoids and neuroblastomas, suggesting that syntenin expression may be related to more aggressive forms of neuroendocrine tumors. In SCLC patients, syntenin overexpression in tumor cells was significantly associated with more extensive and advanced disease at the time of diagnosis (P=0.029). Overexpression of syntenin in SCLC cells that were intrinsically syntenin-low increased the invasiveness of cells and led to the induction of extracellular matrix (ECM)-degrading membrane type 1-matrix metalloproteinase (MT1-MMP) and matrix metalloproteinase 2 (MMP2). In contrast, suppression of syntenin in syntenin-high cells was associated with the downregulation of MT1-MMP. Contrary to the results of previous studies using malignant melanomas and breast carcinomas, signaling cascades were shown to be further transduced through p38 MAPK and PI3K/AKT, with activation of SP1 rather than NF-κB, under circumstances not involving ECM interaction. In addition, the upstream molecule focal adhesion kinase was induced by syntenin activation, in spite of the absence of ECM interaction. These results suggest that syntenin might contribute to the invasiveness of SCLC and could be utilized as a new therapeutic target for controlling invasion and metastasis in SCLC.
1] Department of Pathology, Seoul National University College of Medicine, Seoul, Korea [2] The Tumor Immunity Medical Research Center, Cancer Research Center, Seoul National University College of Medicine, Seoul, Korea [3] Department of Pathology, Konkuk University School of Medicine, Seoul, Korea.
Wook Youn
WY
Kim
The Tumor Immunity Medical Research Center, Cancer Research Center, Seoul National University College of Medicine, Seoul, Korea.
Ji-young
JY
Jang
1] Department of Pathology, Seoul National University College of Medicine, Seoul, Korea [2] The Tumor Immunity Medical Research Center, Cancer Research Center, Seoul National University College of Medicine, Seoul, Korea.
Yoon Kyung
YK
Jeon
Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
Doo Hyun
DH
Chung
The Tumor Immunity Medical Research Center, Cancer Research Center, Seoul National University College of Medicine, Seoul, Korea.
Young Goo
YG
Kim
1] Department of Pathology, Seoul National University College of Medicine, Seoul, Korea [2] The Tumor Immunity Medical Research Center, Cancer Research Center, Seoul National University College of Medicine, Seoul, Korea.
Chul-Woo
CW
Kim
D045744:Cell Line, Tumor; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism*; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D009361:Neoplasm Invasiveness; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D055752:Small Cell Lung Carcinoma / Q000378:metabolism* / Q000473:pathology; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D053676:Syntenins / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D016329:Sp1 Transcription Factor; D053676:Syntenins; D019869:Phosphatidylinositol 3-Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14