The Influence Of Voltage-Gated Potassium Ion Channels On Proliferation Of Ovarian Cancer Cell Lines

Part ITHE EXPRESSION OF VOLTAGE-GATED POTASSIUM IONCHANNELS ON EPITHELIAL OVARIANCANCER CELL LINESObjective: To study the expression of voltage-gated potassium ion channels (Kv)on epithelial ovarian cancer cell lines (SKOV3, 3AO, A2780).Methods: The expression of voltage-gated potassium ion channels (Kv1.1 andKv1.3) mRNA on the SKOV3, 3AO and A2780 cell lines was detected by techniquesof reverse transcription polymerase chain reaction. The expression of voltage-gatedpotassium ion channels (Kv1.1 and Kvl.3) protein on the SKOV3, 3AO and A2780cell line was detected by immunocytochemical methods.Results: SKOV3, 3AO and A2780 cell lines all express Kv1.1 and Kv1.3 mRNA.Kv1.1 is amplified the fragment of 380 bp and Kv1.3 is amplified the fragment of 382bp. Expression of Kv1.1mRNA on SKOV3, 3AO and A2780 cell lines are the same.And expression of Kv1.3mRNA on SKOV3, 3AO and A2780 cell lines are the samealso. Immunocytochemistry showed SKOV3, 3AO and A2780 cell plasma membranesare brown-yellow. This result show Kv1.1 and Kvl.3 channel protein were expressedon SKOV3, 3AO and A2780 cell plasma membranes.Conclusion: Epithelial ovarian cancer cell lines express voltage-gated potassium ionchannels. And the expression of voltage-gated potassium ion channels on differentepithelial ovarian cancer cell lines is the same. Part IITHE INFLUENCE OF VOLTAGE-GATED POTASSIUM IONCHANNELS ON CELL PROLIFERATION AND CELL CYCLE OF EPITHELIAL OVARIAN CANCER CELL LINESObjective: To study the influence of voltage-gated potassium ion channels on cellproliferation and cell cycle of epithelial ovarian cancer cell lines.Methods: The effects of different potassium ion channels on proliferation and cellcycle of SKOV3, 3AO and A2780 cells were observed by means of MTT and flowcytometry.Results:1. The effects of different potassium ion channels on proliferation of epithelialovarian cancer cell lines.(1) 4-Aminopyridine, an inhibitor of voltage-gated potassium ion channels, significantly inhibited the proliferation of SKOV3, 3AO and A2780 cells as measured by MTT. Incubation of the SKOV3 cells with 1, 5, 10mmol/L 4-Aminopyridine resulted reduction in the number of viable cells as compared with the control, the inhibit rate is 35.09%, 54.65%, 69.13% respectively (vs control P<0.01). The inhibit rate is 41.43%, 61.94%, 70.93% respectively (vs control P<0.01) on 3AO cell. And the inhibit rate is 72.41%, 94.60%, 95.34% respectively (vs control P<0.01) on A2780 cell. The inhibit rate of proliferation on A2780 cell by 4-Aminopyridine is stronger than on SKOV3 and 3AO cell (P<0.05>.(2) Charybdotoxin, an inhibitor of Ca²⁺-sensitive potassium ion channels, inhibits the proliferation of the SKOV3 cells with 5, 10, 15nmol/L. And the inhibit rate is 2.64%, 2.95%, 4.01% respectively (vs control P>0.05). The inhibit rate is 2.11%, 2.64%, 3.48% respectively (vs control P>0.05) on 3AO cell. And the inhibit rate is 2.85%, 3.17%, 3.91% respectively (vs control P>0.05) on A2780 cell.(3) Glibenclamide, an inhibitor of ATP-sensitive potassium channels, inhibits the proliferation of the SKOV3 cells with 50, 100, 150μmol/L. And the inhibit rate is 3.06%, 3.91%, 5.49% respectively (vs control P>0.05). The inhibit rate is 3.27%, 3.38%, 4.01% respectively (vs control P>0.05) on 3AO cell. And the inhibit rate is 3.32%, 3.40%, 3.13% respectively (vs control P>0.05) on A2780 cell.(4) The inhibit rate of proliferation on SKOV3 , 3AO and A2780 cell by 4-Aminopyridine is stronger than by charybdotoxin and glibenclamide(P<0.05). The inhibit rate of proliferation on SKOV3, 3AO and A2780 cell by charybdotoxin isn't different significantly from by glibenclamide (P>0.05).2. The effects of different potassium ion channels on cell cycle of epithelial ovarian cancer cell lines.(1) 4-Aminopyridine significantly effected the progression of cell cycle with a 72h treatment of SKOV3, 3AO and A2780 cell. The progression of cell cycle is arrested on G₀/G₁ phase. With 1,5, 10mmol/L 4-Aminopyridine, the proportion of G₀/G₁ phase cells of SKOV3 cell increased from 39.68% to 53.28%, 62.31% and 78.08% respectively. And the proportion of S phase decreased from 57.29% to 45.37%, 36.25% and 20.19% respectively. And the proportion of G₂/M phase decreased from 3.02% to 1.34%, 1.43% and 1.72% respectively (vs control P<0.05). The proportion of G₀/G₁ phase cells of 3AO cell increased from 39.68% to 58.24%, 66.35% and 78.13% respectively. And the proportion of S phase decreased from 57.29% to 39.45%, 32.44% and 20.68% respectively. And the proportion of G₂/M phase decreased from 3.02% to 2.31%, 1.21% and 1.19% respectively (vs control P<0.05).The proportion of G₀/G₁ phase cells of A2780 cell increased from 39.68% to 61.27%, 78.08% and 81.21% respectively. And the proportion of S phase decreased from 57.29% to 37.17%, 20.19% and 17.26% respectively. And the proportion of G₂/M phase decreased from 3.02% to 1.56%, 1.72% and 1.53% respectively (vs control P<0.05). It is no different that the effect of 4-Aminopyridine on the progression of cell cycle of SKOV3, 3AO and A2780 cell.(2) Charybdotoxin doesn't effect the progression of cell cycle with a 72h treatment of SKOV3, 3AO and A2780 cell. With 5, 10, 15nmol/L charybdotoxin, the proportion of G₀/G₁ phase cells of SKOV3 cell changed from 39.68% to 39.23%, 38.98% and 39.36% respectively. And the proportion of S phase changed from 57.29% to 58.22%, 59.59% and 58.27% respectively. And the proportion of G₂/M phase changed from 3.02% to 2.54%, 1.42% and 2.36% respectively (vs control P>0.05). The proportion of G₀/G₁ phase cells of 3AO cell changed from 39.68% to 40.12%, 41.23% and 42.24% respectively. And the proportion of S phase changed from 57.29% to 56.85%, 55.80% and 54.89% respectively. And the proportion of G₂/M phase changed from 3.02% to 3.03%, 2.97% and 2.86% respectively (vs control P>0.05). The proportion of G₀/G₁ phase cells of A2780 cell changed from 39.68% to 38.35%, 38.04% and 39.21% respectively. And the proportion of S phase changed from 57.29% to 57.96%, 58.23% and 58.10% respectively. And the proportion of G₂/M phase changed from 3.02% to 3.68%, 3.73% and 2.68% respectively (vs control P>0.05).(3) Glibenclamide doesn't effect the progression of cell cycle with a 72h treatment of SKOV3, 3AO and A2780 cell. With 50, 100, 150nmol/L glibenclamide, the proportion of G₀/G₁ phase cells of SKOV3 cell changed from 39.68% to 38.87%, 39.12% and 39.36% respectively. And the proportion of S phase changed from 57.29% to 57.65%, 58.25% and 58.45% respectively. And the proportion of G₂/M phase changed from 3.02% to 3.47%, 2.62% and 2.18% respectively (vs control P>0.05). The proportion of G₀/G₁ phase cells of 3AO cell changed from 39.68% to 39.58%, 39.69% and 41.25% respectively. And the proportion of S phase changed from 57.29% to 57.37%, 57.38% and 56.77% respectively. And the proportion of G₂/M phase changed from 3.02% to 3.05%, 2.93% and 1.98% respectively (vs control P>0.05). The proportion of G₀/G₁ phase cells of A2780 cell changed from 39.68% to 39.92%, 40.02% and 40.63% respectively. And the proportion of S phase changed from 57.29% to 56.81%, 56.33% and 57.12% respectively. And the proportion of G₂/M phase changed from 3.02% to 3.26%, 3.65% and 2.24% respectively (vs control P>0.05).(4) The effect of cell cycle on SKOV3, 3AO and A2780 cell by 4-Aminopyridine is stronger than by charybdotoxin and glibenclamide(P<0.05). The effect of cell cycle on SKOV3, 3AO and A2780 cell by charybdotoxin isn't different significantly fromby glibenclamide (P>0.05).Conclusion: Voltage-gated potassium ion channels play an important role in theproliferation and cell cycle of epithelial ovarian cancer cell. But there is no effectCa²⁺-sensitive potassium channels and ATP-sensitive potassium channels onepithelial ovarian cancer cell.