Liver kinase B1 expression (LKB1) is repressed by estrogen receptor alpha (ERα) in MCF-7 human breast cancer cells

► LKB1 expression is lower in ERα-positive MCF-7 than ERα-negative breast cancer cells. ► ERα knock-down in MCF-7s increases LKB1 promoter activity/expression. ► Putative estrogen response elements are present throughout the LKB1 promoter region. ► E2 up-regulates LKB1 transcription/mRNA levels, decreasing ERα expression. ► Actinomycin D transcriptionally blocks the E2-mediated increase in LKB1 mRNA levels.