Overexpression of NaV1.6 channels is associated with the invasion capacity of human cervical cancer
Overexpression of NaV1.6 channels is associated with the invasion capacity of human cervical cancer
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DOI：
10.1002/ijc.26210
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发表时间：
2012-05-01
影响因子：
6.4
通讯作者：
Gomora, Juan C.
中科院分区：
文献类型：
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作者：
Hernandez-Plata, Everardo;Ortiz, Cindy S.;Gomora, Juan C.
电压门控钠通道(VGSC)的功能活性与前列腺癌、乳腺癌等多种肿瘤的侵袭转移行为密切相关。我们之前报道了VGSC在宫颈癌(CAC)原代培养和活检组织中的功能表达。在这里，我们研究了VGSC亚单位的相对表达水平及其在CAC中的可能作用。实时荧光定量聚合酶链式反应显示，CAC组织中NaV1.6a亚单位的基因表达水平约为非癌宫颈组织的40倍。Nav1.7a亚基变体也显示CAC中的mRNA水平增加(类似于20倍)。在CAC样本中也检测到所有四个NAVβ亚基，其中NAVβ1最丰富。NaV1.6和NA1.7a-亚基蛋白在NCC和CAC组织以及原代培养的CAC中均有免疫定位，但在NCC切片中，蛋白主要分布于细胞膜，而在CAC组织和原代培养中，各自的信号较强且广泛分布于细胞质和质膜中。全细胞膜片钳实验证实了细胞膜上NaV1.6通道的功能活性。CN2是一种NaV1.6特异的毒素，它阻断了大约30%的钠电流。河豚毒素和CN2阻断钠通道VGSC对细胞的增殖和迁移均无影响，但体外侵袭力降低约20%。我们的结论是，NaV1.6在CAC中表达上调，可以作为一种新的分子标志物来检测CAC的转移行为。
Functional activity of voltage-gated sodium channels (VGSC) has been associated to the invasion and metastasis behaviors of prostate, breast and some other types of cancer. We previously reported the functional expression of VGSC in primary cultures and biopsies derived from cervical cancer (CaC). Here, we investigate the relative expression levels of VGSC subunits and its possible role in CaC. Quantitative real-time PCR revealed that mRNA levels of NaV1.6 a-subunit in CaC samples were similar to 40-fold higher than in noncancerous cervical (NCC) biopsies. A NaV1.7 a-subunit variant also showed increased mRNA levels in CaC (similar to 20-fold). All four NaV beta subunits were also detected in CaC samples, being NaV beta 1 the most abundant. Proteins of NaV1.6 and NaV1.7 a-subunits were immunolocalized in both NCC and CaC biopsies and in CaC primary cultures as well; however, although in NCC sections proteins were mainly relegated to the plasma membrane, in CaC biopsies and primary cultures the respective signal was stronger and widely distributed in both cytoplasm and plasma membrane. Functional activity of NaV1.6 channels in the plasma membrane of CaC cells was confirmed by whole-cell patch-clamp experiments using Cn2, a NaV1.6-specific toxin, which blocked similar to 30% of the total sodium current. Blocking of sodium channels VGSC with tetrodotoxin and Cn2 did not affect proliferation neither migration, but reduced by similar to 20% the invasiveness of CaC primary culture cells in vitro assays. We conclude that NaV1.6 is upregulated in CaC and could serve as a novel molecular marker for the metastatic behavior of this carcinoma.