The AQP-3 water channel is a pivotal modulator of glycerol-induced chloride channel activation in nasopharyngeal carcinoma cells

Author(s):  
Haifeng Zhang ◽  
Zhiqin Deng ◽  
Lili Yang ◽  
Hai Luo ◽  
Shanwen Liu ◽  
...  
2012 ◽  
Vol 303 (1) ◽  
pp. C14-C23 ◽  
Author(s):  
Liwei Wang ◽  
Wenbo Ma ◽  
Linyan Zhu ◽  
Dong Ye ◽  
Yuan Li ◽  
...  

Acid-activated chloride currents have been reported in several cell types and may play important roles in regulation of cell function. However, the molecular identities of the channels that mediate the currents are not defined. In this study, activation of the acid-induced chloride current and the possible candidates of the acid-activated chloride channel were investigated in human nasopharyngeal carcinoma cells (CNE-2Z). A chloride current was activated when extracellular pH was reduced to 6.6 from 7.4. However, a further decrease of extracellular pH to 5.8 inhibited the current. The current was weakly outward-rectified and was suppressed by hypertonicity-induced cell shrinkage and by the chloride channel blockers 5-nitro-2–3-phenylpropylamino benzoic acid (NPPB), tamoxifen, and 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid disodium salt hydrate (DIDS). The permeability sequence of the channel to anions was I− > Br− > Cl− > gluconate−. Among the ClC chloride channels, ClC-3 and ClC-7 were strongly expressed in CNE-2Z cells. Knockdown of ClC-3 expression with ClC-3 small interfering (si)RNA prevented the activation of the acid-induced current, but silence of ClC-7 expression with ClC-7 siRNA did not significantly affect the current. The results suggest that the chloride channel mediating the acid-induced chloride current was volume sensitive. ClC-3 is a candidate of the channel proteins that mediate or regulate the acid-activated chloride current in nasopharyngeal carcinoma cells.


2020 ◽  
Vol 20 (8) ◽  
pp. 624-637 ◽  
Author(s):  
Qiong Wu ◽  
Manlin Xiang ◽  
Kun Wang ◽  
Zhen Chen ◽  
Lu Long ◽  
...  

Background: Increasing evidence has shown that p62 plays an important role in tumorigenesis. However, relatively little is known about the association between p62 and tumor invasion and metastasis; in addition, its role in NPC (nasopharyngeal carcinoma, NPC) has been rarely investigated. Objective: To investigate the effect of p62 on tumorigenesis and metastasis in nasopharyngeal carcinoma. Methods: Western blotting, immunofluorescent staining and immunohistochemistry were used to evaluate p62 protein expression. Subsequently, cell viability, colony formation, migration, invasion and autophagy assays were performed. anti-p62 autoantibodies in sera were detected by ELISA. These data were correlated with clinicopathological parameters. Results: We confirmed that p62 was significantly up-regulated in NPC tissues. Furthermore, high expression of p62 was observed in NPC cell lines, and especially in the highly metastatic 5-8F cells. In vitro, down-regulation of p62 inhibited proliferation, clone forming ability, autophagy, migration, and invasion in 5-8F cells, whereas p62 overexpression resulted in the opposite effects in 6-10B cells. Moreover, we confirmed that p62 promotes NPC cell proliferation, migration, and invasion by activating ERK (extracellular signal-regulated kinase, ERK). Clinical analysis indicated that high p62 expression correlates with lymph node and distant metastasis (P<0.05). Serum anti-p62 autoantibodies were increased in NPC patients and levels were associated with metastasis. Conclusion : Our data establish p62 targeting ERK as potential determinant in the NPC, which supplies a new pathway to treat NPC. Furthermore, p62 is a potential biomarker which might be closely related to the tumorigenesis and metastasis in NPC.


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