TY - JOUR
T1 - Knockdown of Sox4 expression by RNAi induces apoptosis in ACC3 cells
AU - Pramoonjago, P.
AU - Baras, A. S.
AU - Moskaluk, C. A.
N1 - Funding Information:
We thank all of the participants of the Adenoid Cystic Carcinoma Tumor Registry for their contributions of tissue specimen and support of our research efforts. We thank Angela Miller and Sharon Birdsall for assistance with histologic and immunohistochemical techniques. This work was supported by a grant from the National Institute of Dental and Craniofacial Research (R01-DE-14694).
PY - 2006/9/14
Y1 - 2006/9/14
N2 - Microarray RNA gene expression profiling analysis has shown that Sox4 (Sry-related high mobility group (HMG) box 4) is one of the most upregulated genes in adenoid cystic carcinoma (ACC), relative to non-neoplastic tissue of origin. Here, we show that Sox4 protein is similarly upregulated in ACC by immunohistochemistry of 28 primary cancers and 20 normal tissues. To elucidate the functional significance of these findings, RNA interference (RNAi)-mediated RNA silencing was used to downregulate Sox4 expression in the ACC-derived cell line, ACC3. With confirmed knockdown of Sox4 protein, cell viability was reduced by 51%, with a corresponding increase of apoptosis to 85% as compared to 12% in controls. Apoptosis was confirmed by cell morphology, DNA fragmentation and flow cytometry. Cells could be rescued from the proapoptotic effects of Sox4 RNAi by co-transfection with a construct expressing functional Sox4. Microarray gene expression profiling of RNAi knockdown experiments shows that downregulation of Sox4-modulated expression of critical genes involved in apoptosis and cell cycle control. Overall, our findings suggest that Sox4 contributes to the malignant phenotype of ACC cells by promoting cell survival.
AB - Microarray RNA gene expression profiling analysis has shown that Sox4 (Sry-related high mobility group (HMG) box 4) is one of the most upregulated genes in adenoid cystic carcinoma (ACC), relative to non-neoplastic tissue of origin. Here, we show that Sox4 protein is similarly upregulated in ACC by immunohistochemistry of 28 primary cancers and 20 normal tissues. To elucidate the functional significance of these findings, RNA interference (RNAi)-mediated RNA silencing was used to downregulate Sox4 expression in the ACC-derived cell line, ACC3. With confirmed knockdown of Sox4 protein, cell viability was reduced by 51%, with a corresponding increase of apoptosis to 85% as compared to 12% in controls. Apoptosis was confirmed by cell morphology, DNA fragmentation and flow cytometry. Cells could be rescued from the proapoptotic effects of Sox4 RNAi by co-transfection with a construct expressing functional Sox4. Microarray gene expression profiling of RNAi knockdown experiments shows that downregulation of Sox4-modulated expression of critical genes involved in apoptosis and cell cycle control. Overall, our findings suggest that Sox4 contributes to the malignant phenotype of ACC cells by promoting cell survival.
KW - Adenoid cystic carcinoma
KW - Apoptosis
KW - RNAi
KW - Sox4
UR - http://www.scopus.com/inward/record.url?scp=33748655171&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1209566
DO - 10.1038/sj.onc.1209566
M3 - Article
C2 - 16636670
AN - SCOPUS:33748655171
SN - 0950-9232
VL - 25
SP - 5626
EP - 5639
JO - Oncogene
JF - Oncogene
IS - 41
ER -