Both gene amplification and allelic loss occur at 14q13. 3 in lung cancer

T Harris, Q Pan, J Sironi, D Lutz, J Tian, J Sapkar… - Clinical Cancer …, 2011 - AACR
T Harris, Q Pan, J Sironi, D Lutz, J Tian, J Sapkar, R Perez-Soler, S Keller, J Locker
Clinical Cancer Research, 2011AACR
Abstract Purpose: Because loss of Nkx2-8 increases lung cancer in the mouse, we studied
suppressive mechanisms in human lung cancer. Experimental Design: NKX2-8 is located
within 14q13. 3, adjacent to its close relative TTF1/NKX2-1. We first analyzed LOH of 14q13.
3 in forty-five matched human lung cancer and control specimens. DNA from tumors with
LOH was then analyzed with high-density single-nucleotide polymorphism (SNP) arrays. For
correlation with this genetic analysis, we quantified expression of Nkx2-8 and TTF1 mRNA in …
Abstract
Purpose: Because loss of Nkx2-8 increases lung cancer in the mouse, we studied suppressive mechanisms in human lung cancer.
Experimental Design: NKX2-8 is located within 14q13.3, adjacent to its close relative TTF1/NKX2-1. We first analyzed LOH of 14q13.3 in forty-five matched human lung cancer and control specimens. DNA from tumors with LOH was then analyzed with high-density single-nucleotide polymorphism (SNP) arrays. For correlation with this genetic analysis, we quantified expression of Nkx2-8 and TTF1 mRNA in tumors. Finally, suppressive function of Nkx2-8 was assessed via colony formation assays in five lung cancer cell lines.
Results: Thirteen of forty-five (29%) tumors had LOH. In six tumors, most adenocarcinomas, LOH was caused by gene amplification. The 0.8-Mb common region of amplification included MBIP, SFTA, TTF1, NKX2-8, and PAX9. In 4 squamous or adenosquamous cancers, LOH was caused by deletion. In three other tumors, LOH resulted from whole chromosome mechanisms (14, 14+, or aneuploidy). The 1.2-Mb common region of deletion included MBIP, SFTA, TTF1, NKX2-8, PAX9, SLC25A21, and MIPOL1. Most tumors had low expression of Nkx2-8. Nevertheless, sequencing did not show NKX2-8 mutations that could explain the low expression. TTF1 overexpression, in contrast, was common and usually independent of Nkx2-8 expression. Finally, stable transfection of Nkx2-8 selectively inhibited growth of H522 lung cancer cells.
Conclusions: 14q13.3, which contains NKX2-8, is subject to both amplification and deletion in lung cancer. Most tumors have low expression of Nkx2-8, and its expression can inhibit growth of some lung cancer cells. Clin Cancer Res; 17(4); 690–9. ©2010 AACR.
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