Establishment of transgenic mice carrying gene encoding human zinc finger protein 191

Zinc Finger Protein 24 is a Prognostic Factor in Ovarian Serous Carcinoma

OBJECTIVE

As a member of the zinc finger protein family, zinc finger protein 24 (ZNF24) contains a Cys2His2 zinc finger domain and acts as a transcription factor. ZNF24 has been reported to be downregulated in gastric cancer and breast cancer. However, little is known about its expression and function in ovarian serous carcinoma (OSC).

PATIENTS AND METHODS

We collected 117 OSC patients during 2011 to 2017 and retrospectively retrieved their clinicopathologic characteristics as well as their survival data. Protein level was analyzed by immunohistochemistry, mRNA level was evaluated by RT-qPCR assay, and transcriptional data was obtained from TCGA data sets. The correlations between ZNF24 expression and patients' features were assessed using χ2 test. Univariate and multivariate analyses were used to identify the prognosis predicative potential of ZNF24 in OSC. The function of ZNF24 in the epithelial ovarian cancer cells was also verified by in vitro cellular experiments.

RESULTS

Among the 117 cases, ZNF24 was downregulated in 52 OSC samples (44.6%) and significantly correlated with tumor stages. According to univariate and multivariate analyses, ZNF24 can act as an independent prognostic indicator for the overall survival of OSC patients, whose lower expression was associated with poorer clinical outcomes. Ectopic overexpression and knockdown assays indicated that ZNF24 can negatively regulate the OSC cell viability.

CONCLUSIONS

OSC patients with low level of ZNF24 have worse overall survival compared with those possess high-ZNF24 expression. Downregulated ZNF24 may be involved in the proliferation of OSC, and ZNF24 expression can serve as an independent survival predictor.

Zinc finger protein 191 (ZNF191/Zfp191) is necessary to maintain neural cells as cycling progenitors

The identification of the factors that allow better monitoring of stem cell renewal and differentiation is of paramount importance for the implementation of new regenerative therapies, especially with regard to the nervous and hematopoietic systems. In this article, we present new information on the function of zinc finger protein 191 (ZNF/Zfp191), a factor isolated in hematopoietic cell lines, within progenitors of the central nervous system (CNS). ZNF/Zfp191 has been found to be principally expressed in progenitors of the developing CNS of humans and mice. Such an overlap of the expression patterns in addition to the high homology of the protein in mammals suggested that ZNF/Zfp191 exerts a conserved function within such progenitors. Indeed, ZNF191 knockdown in human neural progenitors inhibits proliferation and leads to the exit of the cell cycle. Conversely, ZNF191 misexpression maintains progenitors in cycle and exerts negative control on the Notch pathway, which prevents them from differentiating. The present data, together with the fact that the inactivation of Zfp191 leads to embryonic lethality, confirm ZNF191 as an essential factor acting for the promotion of the cell cycle and thus maintenance in the progenitor stage. On the bases of expression data, such a function can be extended to progenitor cells of other tissues such as the hematopoietic system, which emphasizes the important issue of further understanding the molecular events controlled by ZNF/Zfp191.

The zinc finger transcription factor 191 is required for early embryonic development and cell proliferation

Human zinc finger protein 191 (ZNF191/ZNF24) was cloned and characterized as a SCAN family member, which shows 94% identity to its mouse homologue zinc finger protein 191 (Zfp191). ZNF191 can specifically interact with an intronic polymorphic TCAT repeat (HUMTH01) in the tyrosine hydroxylase (TH) gene. Allelic variations of HUMTH01 have been stated to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. Zfp191 is widely expressed during embryonic development and in multiple tissues and organs in adult. To investigate the functions of Zfp191 in vivo, we have used homologous recombination to generate mice that are deficient in Zfp191. Heterozygous Zfp191(+/-) mice are normal and fertile. Homozygous Zfp191(-/-) embryos are severely retarded in development and die at approximately 7.5 days post-fertilization. Unexpectedly, in Zfp191(-/-) and Zfp191(+/-) embryos, TH gene expression is not affected. Blastocyst outgrowth experiments and the RNA interference-mediated knockdown of ZNF191 in cultured cells revealed an essential role for Zfp191 in cell proliferation. In further agreement with this function, no viable Zfp191(-/-) cell lines were obtained by derivation of embryonic stem (ES) cells from blastocysts of Zfp191(+/-) intercrosses or by forced homogenotization of heterozygous ES cells at high concentrations of G418. These data show that Zfp191 is indispensable for early embryonic development and cell proliferation.