@misc{KammererSokolowskiHackletal., author = {Kammerer, Sarah and Sokolowski, Armin Andreas and Hackl, Hubert and Platzer, Dieter and Jahn, Stephan Wenzel and El-Heliebi, Amin and Schwarzenbacher, Daniela and Stiegelbauer, Verena and Pichler, Martin and Rezania, Simin and Fiegl, Heidelinde and Peintinger, Florentia and Regitnig, Peter and H{\"o}fler, Gerald and Schreibmayer, Wolfgang and Bauernhofer, Thomas}, title = {KCNJ3 is a new independent prognostic marker for estrogen receptor positive breast cancer patients}, series = {OncoTarget : open access impact journal}, volume = {7}, journal = {OncoTarget : open access impact journal}, number = {51}, doi = {10.18632/oncotarget.13224}, pages = {84705 -- 84717}, abstract = {Numerous studies showed abnormal expression of ion channels in different cancer types. Amongst these, the potassium channel gene KCNJ3 (encoding for GIRK1 proteins) has been reported to be upregulated in tumors of patients with breast cancer and to correlate with positive lymph node status. We aimed to study KCNJ3 levels in different breast cancer subtypes using gene expression data from the TCGA, to validate our findings using RNA in situ hybridization in a validation cohort (GEO ID GSE17705), and to study the prognostic value of KCNJ3using survival analysis. In a total of > 1000 breast cancer patients of two independent data sets we showed a) that KCNJ3 expression is upregulated in tumor tissue compared to corresponding normal tissue (p < 0.001), b) that KCNJ3 expression is associated with estrogen receptor (ER) positive tumors (p < 0.001), but that KCNJ3 expression is variable within this group, and c) that ER positive patients with high KCNJ3 levels have worse overall (p < 0.05) and disease free survival probabilities (p < 0.01), whereby KCNJ3 is an independent prognostic factor (p <0.05). In conclusion, our data suggest that patients with ER positive breast cancer might be stratified into high risk and low risk groups based on the KCNJ3 levels in the tumor.}, language = {en} }