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Suppression of Na+/H+ exchanger 1 by RNA interference or amiloride inhibits human hepatoma cell line SMMC-7721 cell invasion

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Abstract

Na+/H+ exchanger 1 (NHE1), a primary regulator of intracellular pH (pHi) and extracellular pH (pHe), plays a significant role in acidifying the tumor microenvironment, possibly resulting in their malignant potential. However, currently, very little is known about the roles of NHE1 in invasion of hepatocellular carcinoma (HCC) cells. We have recently shown that NHE1 is over-expressed in HCC tissues and that this increased expression is associated with HCC invasiveness. In this study, we also found that NHE1 is over-expressed in HCC cell lines. Subsequently, we silenced NHE1 expression in the human HCC cell line SMMC-7721 using RNA interference (RNAi) and examined the invasiveness and proliferation of NHE1-silenced SMMC-7721 cells and the matrix metalloproteinase-2 (MMP-2) activity. The knockdown of NHE1 expression significantly inhibited the invasive ability of SMMC-7721 cells but had only a minor effect on the cellular proliferation rate. Moreover, NHE1 knockdown significantly reduced the secretion of MMP-2. Further experiment using amiloride (an inhibitor of NHE1) confirmed the above result. Together, these findings indicate that NHE1 has an important role in SMMC-7721 cell invasion and that NHE1 might be a new target of HCC treatment.

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Acknowledgments

We thank all other members of our laboratory for their insight and technical support. This work was supported by grants from the National Natural Science Foundation of China (No. 30872480) and Shanxi Province Natural Science Foundation of China (No. 2008K09-05).

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Authors and Affiliations

  1. Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shanxi Province, 710032, People’s Republic of China

    Xuekang Yang, Desheng Wang, Wei Dong, Zhenshun Song & Kefeng Dou

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  1. Xuekang Yang
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  2. Desheng Wang
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  3. Wei Dong
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  4. Zhenshun Song
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  5. Kefeng Dou
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Correspondence to Kefeng Dou.

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Xuekang Yang and Desheng Wang contributed equally to this work and should be considered as co-first authors.

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Yang, X., Wang, D., Dong, W. et al. Suppression of Na+/H+ exchanger 1 by RNA interference or amiloride inhibits human hepatoma cell line SMMC-7721 cell invasion. Med Oncol 28, 385–390 (2011). https://doi.org/10.1007/s12032-010-9447-x

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  • DOI: https://doi.org/10.1007/s12032-010-9447-x

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