ZCCHC3 and Efp coordinately contribute to the pathophysiology of triple-negative breast cancer by modulating NCAPH

Abstract

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited targeted therapies and high rates of recurrence. We previously showed that Efp promotes TNBC cell proliferation by regulating cell cycle-related gene expression. Recent studies showed that ZCCHC3 interacts with Efp, promoting Efp signaling in innate immune responses. We here characterize whether ZCCHC3 plays a pathophysiological role in TNBC tumorigenesis. We showed that ZCCHC3 silencing significantly repressed the proliferation of TNBC conventional cultured cells and three-dimensional patient-derived spheroid culture, which we established from a clinical TNBC tissue. RNA-sequencing in TNBC cells defined that “cell division” was a major pathway commonly downregulated by ZCCHC3 and Efp silencing, and NCAPH was a cell division-related gene highly downregulated by ZCCHC3 silencing. In a TNBC cell-derived xenograft model, ZCCHC3-specific siRNA injection successfully reduced in vivo TNBC tumor growth and downregulated NCAPH expression. Overall, our findings demonstrate that ZCCHC3 and Efp coordinately promote TNBC progression by regulating NCAPH expression and that ZCCHC3/Efp/NCAPH pathway can be applied to clinical TNBC management.