Unravelling the functional aspect of deregulated LncRNAs in Wnt pathway for the identification of key therapeutic targets in triple negative breast cancer

Abstract

Breast carcinoma is a widespread neoplastic condition affecting women globally. Triple-negative breast carcinoma (TNBC) exhibits heightened fatality rates attributable to its elevated incidence of disease recurrence and unfavorable prognosis. Aberrant stimulation of the Wnt signaling cascade has been discerned in TNBC instances. Recent investigations propose the involvement of long non coding RNAs (lncRNAs) in TNBC pathogenesis by modulating pivotal signaling pathways. This inquiry aims to scrutinize the interplay between lncRNAs and Wnt pathway activation in TNBC. Initially, Wnt signaling was induced in MDA-MB-231 cells using the 7TGP reporter vector, followed by fluorescence-activated cell sorting (FACS) to obtain Wnt-positive (MDA-MB-2317TGP-POS) and Wnt-negative (MDA-MB-2317TGP-NEG) cell populations. The 7TGP vector, featuring 7 TCF binding sites, served as a bimodal Wnt-responsive element promoter. Subsequent RNA-seq analysis was conducted to identify novel WNT-regulating lncRNAs. Recombinant human Wnt3a was later employed to activate the Wnt pathway, and RNA sequencing, along with quantitative reverse transcription polymerase chain reaction (qRT-PCR), disclosed the upregulation of linc00645 in Wnt activated MDA-MB-231 cells. Furthermore, targeted knockdown of the linc00645 transcript in TNBC cells resulted in a substantial reduction in linc00645 expression, cell proliferation, migration, and invasion. These outcomes suggest a potential role for linc00645 in TNBC tumorigenesis. These findings posit linc00645 as an oncogenic lncRNA in Wnt-activated TNBC, proposing it as a viable therapeutic target. In conclusion, our investigation delineates the linc00645/hsa-miR-452-5p/vimentin signaling axis as a pivotal player in the epithelial-mesenchymal transition (EMT) of TNBC cells upon Wnt pathway activation. These results illuminate the regulatory role of linc00645 in Wnt signaling within TNBC and identify a novel targetable mechanism for treating this aggressive breast cancer subtype. newline