DiFeo Analisa, Narla Goutham, Hirshfeld Jennifer, Camacho-Vanegas Olga, Narla Jyothsna, Rose Stephen L, Kalir Tamara, Yao Shen, Levine Alice, Birrer Michael J, Bonome Tomas, Friedman Scott L, Buller Richard E, Martignetti John A
Department of Human Genetics, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, New York 10029, USA.
Clin Cancer Res. 2006 Jun 15;12(12):3730-9. doi: 10.1158/1078-0432.CCR-06-0054.
We investigated the role of the KLF6 tumor suppressor gene and its alternatively spliced isoform KLF6-SV1 in epithelial ovarian cancer (EOC).
We first analyzed tumors from 68 females with EOC for KLF6 gene inactivation using fluorescent loss of heterozygosity (LOH) analysis and direct DNA sequencing and then defined changes in KLF6 and KLF6-SV1 expression levels by quantitative real-time PCR. We then directly tested the effect of KLF6 and KLF6-SV1 inhibition in SKOV-3 stable cell lines on cellular invasion and proliferation in culture and tumor growth, i.p. dissemination, ascites production, and angiogenesis in vivo using BALB/c nu/nu mice. All statistical tests were two sided.
LOH was present in 59% of samples in a cell type-specific manner, highest in serous (72%) and endometrioid (75%) subtypes, but absent in clear cell tumors. LOH was significantly correlated with tumor stage and grade. In addition, KLF6 expression was decreased in tumors when compared with ovarian surface epithelial cells. In contrast, KLF6-SV1 expression was increased approximately 5-fold and was associated with increased tumor grade regardless of LOH status. Consistent with these findings, KLF6 silencing increased cellular and tumor growth, angiogenesis, and vascular endothelial growth factor expression, i.p. dissemination, and ascites production. Conversely, KLF6-SV1 down-regulation decreased cell proliferation and invasion and completely suppressed in vivo tumor formation.
Our results show that KLF6 and KLF6-SV1 are associated with key clinical features of EOC and suggest that their therapeutic targeting may alter ovarian cancer growth, progression, and dissemination.
我们研究了KLF6肿瘤抑制基因及其选择性剪接异构体KLF6-SV1在上皮性卵巢癌（EOC）中的作用。
我们首先使用荧光杂合性缺失（LOH）分析和直接DNA测序，分析了68例EOC女性患者的肿瘤中KLF6基因的失活情况，然后通过定量实时PCR确定KLF6和KLF6-SV1表达水平的变化。接着，我们直接测试了SKOV-3稳定细胞系中KLF6和KLF6-SV1抑制对细胞侵袭、增殖以及使用BALB/c nu/nu小鼠进行体内肿瘤生长、腹腔播散、腹水产生和血管生成的影响。所有统计检验均为双侧检验。
59%的样本以细胞类型特异性方式存在LOH，在浆液性（72%）和子宫内膜样（75%）亚型中最高，但在透明细胞肿瘤中不存在。LOH与肿瘤分期和分级显著相关。此外，与卵巢表面上皮细胞相比，肿瘤中KLF6表达降低。相反，无论LOH状态如何，KLF6-SV1表达增加约5倍，且与肿瘤分级增加相关。与这些发现一致，KLF6沉默增加了细胞和肿瘤生长以及血管生成和血管内皮生长因子表达、腹腔播散和腹水产生。相反，KLF6-SV1下调降低了细胞增殖和侵袭，并完全抑制了体内肿瘤形成。
我们的结果表明，KLF6和KLF6-SV1与EOC的关键临床特征相关，并表明对它们进行治疗靶向可能会改变卵巢癌的生长、进展和播散。
