The involvement of K(v)3.4 voltage-gated potassium channel in the growth of an oral squamous cell carcinoma cell line.
BACKGROUND
In our previous study, an A-type voltage-gated K(+) channel, K(v)3.4, was found more frequently expressed in oral squamous cell carcinoma (OSCC) when compared with non-cancerous matched oral tissue. An OSCC cell line, OECM-1, was found to have moderate level of K(v)3.4 expression.


METHODS
To further elucidate the roles of K(v)3.4 for the involvement of neoplastic process, we amplified K(v)3.4 coding sequence by reverse transcriptase polymerase chain reaction (RT-PCR), constructed an expression vector carrying this sequence and then stably transfected into OECM-1 OSCC cells.


RESULTS
We demonstrated the integration and constitutive expression of K(v)3.4 in the cell. A unique A-type current elicited by such expression in OECM-1 cells was defined by patch clamp analysis. This current pattern can be reversibly blocked by an A-type K(+) channel blocker 2 mM 4-aminopyridine (4-AP). The acquisition of K(v)3.4 activity in OECM-1 cells bestowed growth advantage. However, in 3T3 cell, transfected K(v)3.4 caused only limited increase of growth without forming transformation foci.


CONCLUSIONS
The present study established a stable keratinocyte system carrying functional K(v)3.4 and increase of growth, by which the anti-K(v)3.4 modalities for potential OSCC control can be further investigated.
Lew
Tien-Shen
TS
Institute of Physiology, National Yang-Ming University, Taipei, Taiwan.
Chang
Che-Shoa
CS
Fang
Kung-Ping
KP
Chen
Chian-Yi
CY
Chen
Cheng-Hsiung
CH
Lin
Shu-Chun
SC
D016475:3T3 Cells; D015761:4-Aminopyridine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002455:Cell Division; D045744:Cell Line, Tumor; D002470:Cell Survival; D015972:Gene Expression Regulation, Neoplastic; D015603:Keratinocytes / Q000473:pathology; D051379:Mice; D009062:Mouth Neoplasms / Q000473:pathology*; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000032:analysis / Q000037:antagonists & inhibitors / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated; D015761:4-Aminopyridine