TY - JOUR
T1 - PAX5 is expressed in small-cell lung cancer and positively regulates c-Met transcription
AU - Kanteti, Rajani
AU - Nallasura, Vidya
AU - Loganathan, Sivakumar
AU - Tretiakova, Maria
AU - Kroll, Todd
AU - Krishnaswamy, Soundararajan
AU - Faoro, Leonardo
AU - Cagle, Philip
AU - Husain, Aliya N.
AU - Vokes, Everett E.
AU - Lang, Deborah
AU - Salgia, Ravi
N1 - Funding Information:
We would like to cordially thank Dr Elizabeth Hyjek for her assistance with PAX5 immunohistochemical verification on diagnostic control cases. Grants from NIH/NCI, American Lung Association, Mesothelioma Applied Research Foundation (Jeffrey P Hayes Award), and V-Foundation (Guy Geleerd Memorial Award) awarded to Ravi Salgia supported the work.
PY - 2009/3
Y1 - 2009/3
N2 - PAX5 is a nuclear transcription factor required for B cell development, and its expression was evaluated in upper aerodigestive malignancies and pancreatic cancer by immunoblotting. The PAX5 protein expression was relatively strong in small-cell lung cancer (SCLC, 11/12); however, its expression was not detected in non-SCLC (NSCLC, n=13), mesothelioma (n=7), pancreatic (n=6), esophageal (n=6) and head and neck cancer cell lines (n=12). In comparison, PAX8 and PAX3 expressions were absent or non-detectable in SCLC cell lines; however, PAX8 was expressed in most of the tested NSCLC cell lines (13/13) and also frequently in all the other cell lines. We also detected frequent expressions of PAX2 and PAX9 protein in the various cell lines. Utilizing neuroendocrine tumor samples, we found that the frequency as well as the average intensity of the expression of PAX5 increased from pulmonary carcinoid (9%, moderate and strong PAX5 expression, n=44), to large-cell neuroendocrine carcinoma (LCNC, 27%, n=11) to SCLC (33%, n=76). FISH analysis revealed no translocations of the PAX5 gene, but polyploidy in some SCLC tumor tissues (6/37). We determined that PAX5 could regulate the transcription of c-Met using luciferase-coupled reporter and chromatin immunoprecipitation analysis. In addition, the phospho-c-Met (active form) and PAX5 were both localized to the same intra-nuclear compartment in hepatocyte growth factor treated SCLC cells and interacted with each other. Finally, we determined the therapeutic translational potential of PAX5 using PAX5 knockdown SCLC cells in conjunction with Topoisomerase 1 (SN38) and c-Met (SU11274) inhibitors. Loss of endogenous PAX5 significantly decreased the viability of SCLC cells, especially when combined with SN38 or SU11274, and maximum effect was seen when both inhibitors were used. Therefore, we propose that PAX5 could be an important regulator of c-Met transcription and a potential target for therapy in SCLC.
AB - PAX5 is a nuclear transcription factor required for B cell development, and its expression was evaluated in upper aerodigestive malignancies and pancreatic cancer by immunoblotting. The PAX5 protein expression was relatively strong in small-cell lung cancer (SCLC, 11/12); however, its expression was not detected in non-SCLC (NSCLC, n=13), mesothelioma (n=7), pancreatic (n=6), esophageal (n=6) and head and neck cancer cell lines (n=12). In comparison, PAX8 and PAX3 expressions were absent or non-detectable in SCLC cell lines; however, PAX8 was expressed in most of the tested NSCLC cell lines (13/13) and also frequently in all the other cell lines. We also detected frequent expressions of PAX2 and PAX9 protein in the various cell lines. Utilizing neuroendocrine tumor samples, we found that the frequency as well as the average intensity of the expression of PAX5 increased from pulmonary carcinoid (9%, moderate and strong PAX5 expression, n=44), to large-cell neuroendocrine carcinoma (LCNC, 27%, n=11) to SCLC (33%, n=76). FISH analysis revealed no translocations of the PAX5 gene, but polyploidy in some SCLC tumor tissues (6/37). We determined that PAX5 could regulate the transcription of c-Met using luciferase-coupled reporter and chromatin immunoprecipitation analysis. In addition, the phospho-c-Met (active form) and PAX5 were both localized to the same intra-nuclear compartment in hepatocyte growth factor treated SCLC cells and interacted with each other. Finally, we determined the therapeutic translational potential of PAX5 using PAX5 knockdown SCLC cells in conjunction with Topoisomerase 1 (SN38) and c-Met (SU11274) inhibitors. Loss of endogenous PAX5 significantly decreased the viability of SCLC cells, especially when combined with SN38 or SU11274, and maximum effect was seen when both inhibitors were used. Therefore, we propose that PAX5 could be an important regulator of c-Met transcription and a potential target for therapy in SCLC.
KW - c-Met inhibition
KW - PAX transcription factors
KW - PAX5
KW - RTK
UR - http://www.scopus.com/inward/record.url?scp=61349162234&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=61349162234&partnerID=8YFLogxK
U2 - 10.1038/labinvest.2008.168
DO - 10.1038/labinvest.2008.168
M3 - Article
C2 - 19139719
AN - SCOPUS:61349162234
SN - 0023-6837
VL - 89
SP - 301
EP - 314
JO - Laboratory Investigation
JF - Laboratory Investigation
IS - 3
ER -