Zinc finger protein 750(ZNF750), negatively regulated by miR-17-5p, inhibits proliferation, motility and invasion of colonic cancer cells

The Roles of Zinc Finger Proteins in Colorectal Cancer

Despite colorectal cancer remaining a leading worldwide cause of cancer-related death, there remains a paucity of effective treatments for advanced disease. The molecular mechanisms underlying the development of colorectal cancer include altered cell signaling and cell cycle regulation that may result from epigenetic modifications of gene expression and function. Acting as important transcriptional regulators of normal biological processes, zinc finger proteins also play key roles in regulating the cellular mechanisms underlying colorectal neoplasia. These actions impact cell differentiation and proliferation, epithelial-mesenchymal transition, apoptosis, homeostasis, senescence, and maintenance of stemness. With the goal of highlighting promising points of therapeutic intervention, we review the oncogenic and tumor suppressor roles of zinc finger proteins with respect to colorectal cancer tumorigenesis and progression.

Whole-genome sequencing of extrachromosomal circular DNA of cerebrospinal fluid of medulloblastoma

BACKGROUND

Medulloblastoma (MB) is a malignant tumor associated with a poor prognosis in part due to a lack of effective detection methods. Extrachromosomal circular DNA (eccDNA) has been associated with multiple tumors. Nonetheless, little is currently known on eccDNA in MB.

METHODS

Genomic features of eccDNAs were identified in MB tissues and matched cerebrospinal fluid (CSF) and compared with corresponding normal samples using Circle map. The nucleotides on both sides of the eccDNAs' breakpoint were analyzed to understand the mechanisms of eccDNA formation. Bioinformatics analysis combined with the Gene Expression Omnibus (GEO) database identified features of eccDNA-related genes in MB. Lasso Cox regression model, univariate and multivariate Cox regression analysis, time-dependent ROC, and Kaplan-Meier curve were used to assess the potential diagnostic and prognostic value of the hub genes.

RESULTS

EccDNA was profiled in matched tumor and CSF samples from MB patients, and control, eccDNA-related genes enriched in MB were identified. The distribution of eccDNAs in the genome was closely related to gene density and the mechanism of eccDNA formation was evaluated. EccDNAs in CSF exhibited similar distribution with matched MB tissues but were differentially expressed between tumor and normal. Ten hub genes prominent in both the eccDNA dataset and the GEO database were selected to classify MB patients to either high- or low-risk groups, and a prognostic nomogram was thus established.

CONCLUSIONS

This study provides preliminary evidence of the characteristics and formation mechanism of eccDNAs in MB and CSF. Importantly, eccDNA-associated hub genes in CSF could be used as diagnostic and prognostic biomarkers for MB.

ZNF750 facilitates carcinogenesis via promoting the expression of long non-coding RNA CYTOR and influences pharmacotherapy response in colon adenocarcinoma

The epidermal cell differentiation regulator zinc finger protein 750 (ZNF750) is a transcription factor containing the Cys2His2 (C2H2) domain, the zinc finger structure of which is located at the N-terminal 25‍‍-‍46 amino acids of ZNF750. It can promote the expression of differentiation-related factors while inhibiting the expression of progenitor cell-related genes. ZNF750 is directly regulated by p63 (encoded by the TP63 gene, belonging to the TP53 superfamily). The Krüppel-like factor 4 (KLF4), repressor element-1 (RE-1)‍-silencing transcription factor (REST) corepressor 1 (RCOR1), lysine demethylase 1A (KDM1A), and C-terminal-binding protein 1/2 (CTBP1/2) chromatin regulators cooperate with ZNF750 to repress epidermal progenitor genes and activate the expression of epidermal terminal differentiation genes (Sen et al., 2012; Boxer et al., 2014). Besides, ZNF750 and the regulatory network composed of bone morphogenetic protein (BMP) signaling pathway, long non-coding RNAs (lncRNAs) (anti-differentiation non-coding RNA (ANCR) and tissue differentiation-inducing non-protein coding RNA (TINCR)), musculoaponeurotic fibrosarcoma oncogene (MAF)/MAF family B (MAFB), grainy head-like 3 (GRHL3), and positive regulatory domain zinc finger protein 1 (PRDM1) jointly promote epidermal cell differentiation (Sen et al., 2012).

PAX6 upstream antisense RNA (PAUPAR) inhibits colorectal cancer progression through modulation of the microRNA (miR)-17-5p / zinc finger protein 750 (ZNF750) axis

Researchers have demonstrated that long non-coding RNAs (lncRNAs) are vital in colorectal cancer (CRC) progression. Here, we aimed to explore the function of lncRNA PAX6 upstream antisense RNA (PAUPAR) in the development of CRC. In the present study, PAUPAR and microRNA (miR)-17-5p expression levels in CRC tissues and cells were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Western blot analysis was adopted to examine ZNF750 expression at the protein level in CRC cells. CRC cell proliferation was examined by colony formation experiment and 5-Bromo-2-deoxyUridine (BrdU) experiment. CRC cell migration and invasion were assessed by Transwell experiments. Apoptosis was measured using the TUNEL experiment. The targeting relationship between PAUPAR and miR-17-5p was confirmed using dual-luciferase reporter gene and RNA immunoprecipitation (RIP) experiments. We demonstrated that PAUPAR was markedly down-modulated in CRC, and its low expression was significantly related to increased T stage and local lymph node metastasis. Knockdown of PAUPAR enhanced CRC cell proliferation, migration and invasion, and restrained apoptosis relative to controls, whereas PAUPAR overexpression caused the opposite effects. Moreover, rescue experiments showed that miR-17-5p inhibitor could reverse the role of PAUPAR knockdown on the malignant phenotypes of CRC cells. Additionally, PAUPAR could positively regulate the expression of ZNF750 via repressing miR-17-5p. Taken together, these findings suggest that PAUPAR/miR-17-5p/ZNF750 axis is a novel mechanism implicated in CRC progression.