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.