The Eag potassium channel as a new prognostic marker in ovarian cancer.
BACKGROUND
Ovarian cancer is the second most common cancer of the female genital tract in the United Kingdom (UK), accounting for 6% of female deaths due to cancer. This cancer is associated with poor survival and there is a need for new treatments in addition to existing chemotherapy to improve survival. Potassium (K+) channels have been shown to be overexpressed in various cancers where they appear to play a role in cell proliferation and progression.


OBJECTIVE
To determine the expression of the potassium channels Eag and HERG in ovarian cancer tissue and to assess their role in cell proliferation.


METHODS
The expression of Eag and HERG potassium channels was examined in an ovarian cancer tissue microarray. Their role in cell proliferation was investigated by blocking voltage-gated potassium channels in an ovarian cancer cell line (SK-OV-3).


RESULTS
We show for the first time that high expression of Eag channels in ovarian cancer patients is significantly associated with poor survival (P = 0.016) unlike HERG channel expression where there was no correlation with survival. There was also a significant association of Eag staining with high tumour grade (P = 0.014) and presence of residual disease (P = 0.011). Proliferation of SK-OV-3 cells was significantly (P < 0.001) inhibited after treatment with voltage gated K+ channel blockers.


CONCLUSIONS
This novel finding demonstrates a role for Eag as a prognostic marker for survival in patients with ovarian cancer.
Department of Obstetrics and Gynaecology, School of Graduate Entry Medicine and Health, Royal Derby Hospital, Uttoxeter Road, Derby DE22 3DT, UK. Viren.Asher@nottingham.ac.uk
Viren
V
Asher
Raheela
R
Khan
Averil
A
Warren
Robert
R
Shaw
Gerhard V
GV
Schalkwyk
Anish
A
Bali
Heidi M
HM
Sowter
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D026902:Potassium Channel Blockers / Q000494:pharmacology; D013997:Time Factors; D046888:Tissue Array Analysis; D016896:Treatment Outcome; D015854:Up-Regulation; D055815:Young Adult
D014408:Biomarkers, Tumor; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human; D026902:Potassium Channel Blockers