Expression And Potential Functions Of Insulin-like Growth Factor 2 MRNA-binding Protein 1(IGF2BP1) In Human Skin Squamous Cell Carcinoma(SCC)

Objective:The present study examined expression and potential functions of insulin-like growth factor 2 mRNA-binding protein 1(IGF2BP1)in human skin squamous cell carcinoma(SCC).Methods? Western blot assay and qRT-PCR assay were performed to test IGF2BP1 mRNA and protein expression in human skin SCC cells and tissues.? Genetic methods,including lentiviral shRNA,CRISPR/Cas9 and ectopic overexpression were applied to manipulate IGF2BP1 expression in skin SCC cells.? CCK-8 assay,BrdU ELISA assay,clonogenicity assay were applied to test the potential effect of IGF2BP1 expression change on skin SCC survival and proliferation.? qRT-PCR assay was performed to test expression of LncRNA THOR("Lnc-THOR")in human skin SCC cells.? siRNA was utilized to knockdown Lnc-THOR in A431 skin SCC cells,its effect on cell survival and proliferation was analyzed.? A431 xenograft tumor severe combined immunodeficient(SCID)mice model was applied by inoculating normal and IGF2BP1-silenced or-KO cells,tumor growth in vivo was analyzed.Results:? IGF2BP1 mRNA and protein expression levels were elevated in established(A431 line)and primary human skin SCC cells.? IGF2BP1 expression was elevated in human skin SCC tissues,as compared to the normal skin tissues.? In skin SCC cells,IGF2BP1 silencing or CRISPR/Cas9 knockout decreased levels of IGF2BP1-stablized mRNAs,including IGF2,CD44,Glil and Myc.? Furthermore,skin SCC cell survival and proliferation were inhibited by IGF2BP1 silencing/knockout.? Forced over-expression of IGF2BP1 further promoted A431 cell survival and proliferation.Furthermore,siRNA-mediated knockdown of IGF2BP1-bound long non-coding RNA THOR("Lnc-THOR")similarly depleted IGF2BP1-dependent mRNAs,causing inhibition on A431 cell survival and proliferation.?In vivo,IGF2BP1 silencing or knockout inhibited A431 tumor xenograft growth in mice.Conclusions.IGF2BP1 over-expression in skin SCC cells is essential for cell survival and growth.IGF2BP1 could be a pivotal therapeutic target protein for human skin SCC.