EIYMNVPV Motif Is Essential For A1CF Nucleus Localization And A1CF (-8aa) Promotes Proliferation Of Breast Cancer Cells Via Up-Regulation Of IL-6 Expression

Apobec-1 complementation factor(A1CF) is an hnRNP family member to mediate apolipoprotein-B mRNA editing. Additionally, it could stabilize Interleukin-6(IL-6) mRNA at the posttranscriptional regulation to modulate liver regeneration. However, A1 CF contains two variants-A1CF64 and A1CF65, distinguished by the appearance of 24nucleotides/ EIYMNVPV motif. To highlight their construction characters,we considered the variant excluding EIYMNVPV motif as A1CF(-8aa),and the other including EIYMNVPV motif as A1 CF. Interestingly, we firstly demonstrated that EIYMNVPV motif was essential for A1 CF nucleus localization, A1CF(-8aa) and A1 CF respectively located in cytoplasm and nucleus. More importantly, our results showed that A1CF(-8aa) transfected MDA-MB-231 cells promoted proliferation,accompanying with an rising proliferating cell nuclear antigen(PCNA).Furthermore, we found that the mRNA and protein level expression of IL-6 was up-regulating. At the same time, silencing IL-6 could attenuate the A1CF(-8aa)-induced proliferation in MDA-MB-231 cells. Notably,these findings suggest that A1CF(-8aa) promoted proliferation of MDA-MB-231 cells viewing IL-6 as target. So, EIYMNVPV motif could be developed as a potential target for basal-like breast cancer therapy.