TY - JOUR
T1 - Podocalyxin-like 1 is associated with tumor aggressiveness and metastatic gene expression in human oral squamous cell carcinoma
AU - Lin, Cheng Wei
AU - Sun, Min Siou
AU - Wu, Han Chung
PY - 2014/8
Y1 - 2014/8
N2 - Metastasis-mediated death remains a major challenge in cancer treatment due to the lack of identifiable biomarkers for early diagnosis. Identifying tumor-specific biomarkers is critical for the development of diagnostic and therapeutic tools. In the present study, we found that podocalyxin-like 1 (PODXL), a cell surface glycoprotein, was overexpressed in cancer tissues and was upregulated in lymph node metastatic tumor cells. The expression of PODXL was associated with the migratory ability of human oral squamous cell carcinoma (OSCC). Knockdown of PODXL by small hairpin RNA in the SAS OSCC cell line reduced tumor migration and invasion, and inhibited cell proliferation and colony formation. Suppression of PODXL resulted in downregulation of focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL silencing inhibited filopodia formation, and suppressed F-actin and cortactin colocalization. In addition, PODXL expression was associated with the DNA methylation status, and treatment with the DNA methyltransferase inhibitor 5-aza-deoxycytidine increased the PODXL transcriptional level. Moreover, DNA microarray analysis data revealed that suppression of PODXL significantly affected subsets of genes associated with extra-cellular matrix organization, the epithelial-mesenchymal transition, and the expression of metastasis-related cytokines. Collectively, these data showed that the overexpression of PODXL may be associated with tumor aggressiveness and that PODXL could be a diagnostic biomarker for metastatic OSCC.
AB - Metastasis-mediated death remains a major challenge in cancer treatment due to the lack of identifiable biomarkers for early diagnosis. Identifying tumor-specific biomarkers is critical for the development of diagnostic and therapeutic tools. In the present study, we found that podocalyxin-like 1 (PODXL), a cell surface glycoprotein, was overexpressed in cancer tissues and was upregulated in lymph node metastatic tumor cells. The expression of PODXL was associated with the migratory ability of human oral squamous cell carcinoma (OSCC). Knockdown of PODXL by small hairpin RNA in the SAS OSCC cell line reduced tumor migration and invasion, and inhibited cell proliferation and colony formation. Suppression of PODXL resulted in downregulation of focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL silencing inhibited filopodia formation, and suppressed F-actin and cortactin colocalization. In addition, PODXL expression was associated with the DNA methylation status, and treatment with the DNA methyltransferase inhibitor 5-aza-deoxycytidine increased the PODXL transcriptional level. Moreover, DNA microarray analysis data revealed that suppression of PODXL significantly affected subsets of genes associated with extra-cellular matrix organization, the epithelial-mesenchymal transition, and the expression of metastasis-related cytokines. Collectively, these data showed that the overexpression of PODXL may be associated with tumor aggressiveness and that PODXL could be a diagnostic biomarker for metastatic OSCC.
KW - Epigenetic regulation
KW - Human oral squamous cell carcinoma
KW - Invasion
KW - Metastasis
KW - Podocalyxin-like 1
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U2 - 10.3892/ijo.2014.2427
DO - 10.3892/ijo.2014.2427
M3 - Article
C2 - 24821609
AN - SCOPUS:84902581844
SN - 1019-6439
VL - 45
SP - 710
EP - 718
JO - International Journal of Oncology
JF - International Journal of Oncology
IS - 2
ER -