RING domain of zinc finger protein like 1 is essential for cell proliferation in endometrial cancer cell line RL95-2

Endometrial cancer (EC) is the fourth most common cancer in women and exhibits increasing incidence and mortality. Some reports showed that the 5-year survival rate of EC was closely associated with the diagnosed stage. It is urgent to screen for sensitive and specific targets to improve early detection and EC therapy. In our study, we found that zinc finger protein like 1 (ZFPL1) was highly expressed in EC tissues and the EC cell line RL95-2, as detected via RT-qPCR and western blot analysis. Immunocytochemistry results showed that ZFPL1 was localized in the Golgi complex dependent on the C-terminal transmembrane domain. The MTT and EdU stains were employed to examine the effect of ZFPL1 on cell proliferation. We found that the silencing of ZFPL1 blocked cell proliferation and the expression of p-Akt308 and p-Akt473 but improved the protein level of PTEN. The overexpression of ZFPL1 and ZFPL1ΔTMD (deletion of the transmembrane domain) promoted cell proliferation and induced the expression of p-Akt308 and p-Akt473. However, the overexpression of ZFPL1ΔRING (deletion of the RING domain) caused loss of the function of ZFPL1 in cell proliferation and the PI3K/Akt pathway. In summary, ZFPL1 induced RL95-2 cell proliferation and was involved in PI3K/Akt pathway, suggesting the oncogenic role of ZFPL1 during EC development. Additionally, the RING domain was essential for the function of ZFPL1. These findings provided a new biomarker for EC diagnosis and therapy.