TY - JOUR
T1 - BRAF V600E maintains proliferation, transformation, and tumorigenicity of BRAF-mutant papillary thyroid cancer cells
AU - Liu, Dingxie
AU - Liu, Zhi
AU - Condouris, Stephen
AU - Xing, Michael Mingzhao
N1 - Funding Information:
This study was supported by National Institutes of Health RO-1 Grant CA113507-01 and a pilot SPORE support (to M.X.).
PY - 2007/6
Y1 - 2007/6
N2 - Context: Although the BRAF V600E mutant can initiate the formation of papillary thyroid cancer (PTC), it is unclear whether it is required to maintain cell proliferation, transformation, and tumor growth of BRAF mutation-harboring PTC. Objective: The aim of the study was to investigate whether BRAF V600E is required for the proliferation, transformation, and tumorigenicity of BRAF mutation-harboring PTC cells. Design: We addressed this issue using BRAF small interference RNA (siRNA) to transfect stably several BRAF mutation-harboring PTC cell lines, isolated clones with stable suppression of BRAF, and assessed their ability to proliferate, transform, and grow xenograft tumors in nude mice. Results: PTC cell proliferation and transformation were suppressed in specific BRAF siRNA clones, but not in control scrambled siRNA clones. Specifically, taking the advantage of stable BRAF knockdown, we were able to show continued suppression of PTC cell proliferation and transformation, or anchorage-independent colony formation in soft agar, after long-term culture. Moreover, we also demonstrated that in vivo tumorigenicity and growth of tumors from the specific BRAF siRNA cell clones in nude mice were suppressed compared with control clones. Conclusions: BRAF V600E is not only an initiator of PTC as demonstrated previously but is also a maintainer of proliferation, transformation, and tumorigenicity of PTC cells harboring BRAF mutation, and growth of tumors derived from such cells continues to depend on BRAF V600E. These results provide further support for potentially effective therapy targeted at BRAF for BRAF mutation-harboring PTC.
AB - Context: Although the BRAF V600E mutant can initiate the formation of papillary thyroid cancer (PTC), it is unclear whether it is required to maintain cell proliferation, transformation, and tumor growth of BRAF mutation-harboring PTC. Objective: The aim of the study was to investigate whether BRAF V600E is required for the proliferation, transformation, and tumorigenicity of BRAF mutation-harboring PTC cells. Design: We addressed this issue using BRAF small interference RNA (siRNA) to transfect stably several BRAF mutation-harboring PTC cell lines, isolated clones with stable suppression of BRAF, and assessed their ability to proliferate, transform, and grow xenograft tumors in nude mice. Results: PTC cell proliferation and transformation were suppressed in specific BRAF siRNA clones, but not in control scrambled siRNA clones. Specifically, taking the advantage of stable BRAF knockdown, we were able to show continued suppression of PTC cell proliferation and transformation, or anchorage-independent colony formation in soft agar, after long-term culture. Moreover, we also demonstrated that in vivo tumorigenicity and growth of tumors from the specific BRAF siRNA cell clones in nude mice were suppressed compared with control clones. Conclusions: BRAF V600E is not only an initiator of PTC as demonstrated previously but is also a maintainer of proliferation, transformation, and tumorigenicity of PTC cells harboring BRAF mutation, and growth of tumors derived from such cells continues to depend on BRAF V600E. These results provide further support for potentially effective therapy targeted at BRAF for BRAF mutation-harboring PTC.
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U2 - 10.1210/jc.2006-1613
DO - 10.1210/jc.2006-1613
M3 - Article
C2 - 17374713
AN - SCOPUS:34347208361
SN - 0021-972X
VL - 92
SP - 2264
EP - 2271
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 6
ER -