title: The investigation of miR-221-3p and PAK1 gene expressions in breast cancer cell lines.
abstract: The most common malignancy in women is breast cancer. Drug resistance in the treatment of cancer still remains a major clinical concern. Resistance to tamoxifen is seen in half of the recurrences in breast cancer. The anti-estrogen tamoxifen gains agonistic property by transactivating ERα. PAK1-mediated phosphorylation of serine 305 (S305) of ERα leads to resistance to tamoxifen. In our study, PAK1-induced suggestive tamoxifen resistance was designed. According to our hypothesis, phosphorylation of ERα-S305 by PAK1 may be reversed by PAK1 transcriptional inhibition by miR-221-3p due to miR-221-3p targeting the 3' UTR of PAK1. For this purpose, we used Real-time PCR (qRT-PCR) to measure the expression level of miR-221-3p in ER-positive breast cancer cell lines (ZR-75-1, MCF7) and breast epithelial cell line, hTERT-HME1, as control in the laboratory in our department. The increase in the expression of PAK1 depending on miR-221-3p may be related to ZR-75-1 cell line which has invasive characteristic but other two ER+ cancer cell lines, MCF7 and HCC1500, have milder cancer severity. miR-221-3p may have a role on regulation of PAK1 expression because miR-221-3p expression level decreases while PAK1 expression level increases in SKBR3 cell line. miR-221-3p and PAK1 expressions in MDA-MB-231 cell line are higher than that of hTERT-HME1 cell line. This may mean that miR-221-3p has no regulatory effect on of PAK1 expression in this cell line. According to these results, miR-221-3p may give crucial information about molecular mechanism of the disease upon PAK1 activity or different mechanisms with respect to histopathology and severity of breast cancer.
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey. Electronic address: sercanergun@gantep.edu.tr.
authors.forename: Sercan
authors.initials: S
authors.lastname: Ergun
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Tayeb Sadiq
authors.initials: TS
authors.lastname: Tayeb
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Arslan
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Temiz
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Kaifee
authors.initials: K
authors.lastname: Arman
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Safdar
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Hasan
authors.initials: H
authors.lastname: Dağlı
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Korkmaz
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Gülper
authors.initials: G
authors.lastname: Nacarkahya
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Sevil
authors.initials: S
authors.lastname: Kırkbeş
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Oztuzcu
mesh_terms: D020413:3' Untranslated Regions; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D060888:Real-Time Polymerase Chain Reaction; D013629:Tamoxifen / Q000494:pharmacology; D054462:p21-Activated Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs; D013629:Tamoxifen; D054462:p21-Activated Kinases; C525709:MIR221, human; C515903:PAK1 protein, human
keywords: Breast cancer; PAK1; miR-221-3p; qRT-PCR