TY - JOUR
T1 - Identification of PADI2 as a potential breast cancer biomarker and therapeutic target
AU - McElwee, John L.
AU - Mohanan, Sunish
AU - Griffith, Obi L.
AU - Breuer, Heike C.
AU - Anguish, Lynne J.
AU - Cherrington, Brian D.
AU - Palmer, Ashley M.
AU - Howe, Louise R.
AU - Subramanian, Venkataraman
AU - Causey, Corey P.
AU - Thompson, Paul R.
AU - Gray, Joe W.
AU - Coonrod, Scott A.
N1 - Funding Information:
This work was supported in part by funding through the DOD Era of Hope Award W871XWH-07-1-0372 to SAC, and through a National Institutes of Health Graduate Fellowship (Grant # T32HD057854) to JLM. In addition, work on the RNA-seq data was supported in part by the following funding sources: Director, Office of Science, Office of Biological & Environmental Research, of the U.S. Department of Energy under Contract # DE-AC02-05CH11231 and fellowship from the Canadian Institutes of Health Research to OLG. The RNA-seq work was also supported by the Department of the Army, award: W81XWH-07-1-0663 (The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702–5014 is the awarding and administering acquisition office) and by the National Institutes of Health, National Cancer Institute grant, the U54 CA 112970 to JWG. The content of the information does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred.
PY - 2012/10/30
Y1 - 2012/10/30
N2 - Background: We have recently reported that the expression of peptidylarginine deiminase 2 (PADI2) is regulated by EGF in mammary cancer cells and appears to play a role in the proliferation of normal mammary epithelium; however, the role of PADI2 in the pathogenesis of human breast cancer has yet to be investigated. Thus, the goals of this study were to examine whether PADI2 plays a role in mammary tumor progression, and whether the inhibition of PADI activity has anti-tumor effects.Methods: RNA-seq data from a collection of 57 breast cancer cell lines was queried for PADI2 levels, and correlations with known subtype and HER2/ERBB2 status were evaluated. To examine PADI2 expression levels during breast cancer progression, the cell lines from the MCF10AT model were used. The efficacy of the PADI inhibitor, Cl-amidine, was tested in vitro using MCF10DCIS cells grown in 2D-monolayers and 3D-spheroids, and in vivo using MCF10DCIS tumor xenografts. Treated MCF10DCIS cells were examined by flow-cytometry to determine the extent of apoptosis and by RT2 Profiler PCR Cell Cycle Array to detect alterations in cell cycle associated genes.Results: We show by RNA-seq that PADI2 mRNA expression is highly correlated with HER2/ERBB2 (p = 2.2 × 106) in luminal breast cancer cell lines. Using the MCF10AT model of breast cancer progression, we then demonstrate that PADI2 expression increases during the transition of normal mammary epithelium to fully malignant breast carcinomas, with a strong peak of PADI2 expression and activity being observed in the MCF10DCIS cell line, which models human comedo-DCIS lesions. Next, we show that a PADI inhibitor, Cl-amidine, strongly suppresses the growth of MCF10DCIS monolayers and tumor spheroids in culture. We then carried out preclinical studies in nude (nu/nu) mice and found that Cl-amidine also suppressed the growth of xenografted MCF10DCIS tumors by more than 3-fold. Lastly, we performed cell cycle array analysis of Cl-amidine treated and control MCF10DCIS cells, and found that the PADI inhibitor strongly affects the expression of several cell cycle genes implicated in tumor progression, including p21, GADD45α, and Ki67.Conclusion: Together, these results suggest that PADI2 may function as an important new biomarker for HER2/ERBB2+ tumors and that Cl-amidine represents a new candidate for breast cancer therapy.
AB - Background: We have recently reported that the expression of peptidylarginine deiminase 2 (PADI2) is regulated by EGF in mammary cancer cells and appears to play a role in the proliferation of normal mammary epithelium; however, the role of PADI2 in the pathogenesis of human breast cancer has yet to be investigated. Thus, the goals of this study were to examine whether PADI2 plays a role in mammary tumor progression, and whether the inhibition of PADI activity has anti-tumor effects.Methods: RNA-seq data from a collection of 57 breast cancer cell lines was queried for PADI2 levels, and correlations with known subtype and HER2/ERBB2 status were evaluated. To examine PADI2 expression levels during breast cancer progression, the cell lines from the MCF10AT model were used. The efficacy of the PADI inhibitor, Cl-amidine, was tested in vitro using MCF10DCIS cells grown in 2D-monolayers and 3D-spheroids, and in vivo using MCF10DCIS tumor xenografts. Treated MCF10DCIS cells were examined by flow-cytometry to determine the extent of apoptosis and by RT2 Profiler PCR Cell Cycle Array to detect alterations in cell cycle associated genes.Results: We show by RNA-seq that PADI2 mRNA expression is highly correlated with HER2/ERBB2 (p = 2.2 × 106) in luminal breast cancer cell lines. Using the MCF10AT model of breast cancer progression, we then demonstrate that PADI2 expression increases during the transition of normal mammary epithelium to fully malignant breast carcinomas, with a strong peak of PADI2 expression and activity being observed in the MCF10DCIS cell line, which models human comedo-DCIS lesions. Next, we show that a PADI inhibitor, Cl-amidine, strongly suppresses the growth of MCF10DCIS monolayers and tumor spheroids in culture. We then carried out preclinical studies in nude (nu/nu) mice and found that Cl-amidine also suppressed the growth of xenografted MCF10DCIS tumors by more than 3-fold. Lastly, we performed cell cycle array analysis of Cl-amidine treated and control MCF10DCIS cells, and found that the PADI inhibitor strongly affects the expression of several cell cycle genes implicated in tumor progression, including p21, GADD45α, and Ki67.Conclusion: Together, these results suggest that PADI2 may function as an important new biomarker for HER2/ERBB2+ tumors and that Cl-amidine represents a new candidate for breast cancer therapy.
KW - Breast cancer
KW - Citrullination
KW - Cl-amidine
KW - HER2/ERBB2
KW - Luminal
KW - PAD2/PADI2
KW - Peptidylarginine deiminase
UR - http://www.scopus.com/inward/record.url?scp=84867896479&partnerID=8YFLogxK
U2 - 10.1186/1471-2407-12-500
DO - 10.1186/1471-2407-12-500
M3 - Article
C2 - 23110523
AN - SCOPUS:84867896479
SN - 1471-2407
VL - 12
JO - BMC Cancer
JF - BMC Cancer
M1 - 500
ER -