Dataset Information

A feedback circuit of miR-34a/MDM4/p53 regulates apoptosis in chronic lymphocytic leukemia cells.

ABSTRACT:

Background

Dysfunction of apoptosis is a significant characteristic in chronic lymphocytic leukemia (CLL). Murine double minute 4 (MDM4), miR-34a and TP53 are found to participate in modulating cellular apoptosis while the specific mechanism keeps unclear. This study was designed to investigate the potential feedback circuit among MDM4, miR-34a and TP53.

Methods

According to the bioinformatic approaches, there are 4 miR-34a candidate binding domains in MDM4. Use dual luciferase reporter gene to verify the regulation between miR-34a and MDM4. Flow cytometry was used to detect the change of apoptosis level in CLL cells before and after miR-34a mimics and shMDM4 were respectively transfected into primary CLL cells in vitro. Meanwhile, Real-time PCR was used to detect the change of RNA expression of MDM4, miR-34a and TP53.

Results

Up-regulated expression of miR-34a or down-regulated expression of MDM4 could increase apoptosis of CLL cells, inhibit expression of MDM4 and decrease expression of p53 in mRNA level compared to negative control (NC) or shNC (P<0.05). The luminescence of psiCHECK-2-MDM4 EXON 11 can be effectively inhibited by miR-34a (P<0.05).

Conclusions

MiR-34a could modulate MDM4 by binding to MDM4 exon 11 instead of 3'UTR. This research thus highlights a forceful evidence for miR-34a/MDM4/p53 feedback circuit in CLL apoptosis.

SUBMITTER: Cao L

PROVIDER: S-EPMC8797636 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Publications

A feedback circuit of miR-34a/MDM4/p53 regulates apoptosis in chronic lymphocytic leukemia cells.

Cao Lei L Liu Yun Y Lu Jin-Bo JB Miao Yi Y Du Xin-Yi XY Wang Rong R Yang Hui H Xu Wei W Li Jian-Yong JY Fan Lei L

Translational cancer research 20201001 10

<h4>Background</h4>Dysfunction of apoptosis is a significant characteristic in chronic lymphocytic leukemia (CLL). Murine double minute 4 (MDM4), miR-34a and TP53 are found to participate in modulating cellular apoptosis while the specific mechanism keeps unclear. This study was designed to investigate the potential feedback circuit among MDM4, miR-34a and TP53.<h4>Methods</h4>According to the bioinformatic approaches, there are 4 miR-34a candidate binding domains in MDM4. Use dual luciferase re ...[more]

PMID: 35117225

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Project description:BackgroundTP53 mutation/deletion is uncommon in chronic lymphocytic leukemia (CLL). We postulated that components of TP53-centered tumor suppressor network, miR-34b/c, in addition to DAPK1 and miR-34a might be inactivated by DNA hypermethylation. Moreover, we tested if miR-34b/c methylation might correlate with miR-203 or miR-124-1 methylation in CLL.MethodsmiR-34b/c, miR-34a and DAPK1 methylation was studied in 11 normal controls, 7 CLL cell lines, and 78 diagnostic CLL samples by methylation-specific polymerase chain reaction. MEC-1 cells were treated with 5-Aza-2'-deoxycytidine for reversal of methylation-associated miRNA silencing. Tumor suppressor properties of miR-34b were demonstrated by over-expression of precursor miR-34b in MEC-1 cells.ResultsmiR-34b/c promoter was unmethylated in normal controls, but completely methylated in 4 CLL cell lines. miR-34b/c expression was inversely correlated with miR-34b/c methylation. Different MSP statuses of miR-34b/c, including complete methylation and complete unmethylation, were verified by quantitative bisulfite pyrosequencing. 5-Aza-2'-deoxycytidine treatment resulted in promoter demethylation and miR-34b re-expression in MEC1 cells. Moreover, over-expression of miR-34b resulted in inhibition of cellular proliferation and increased cell death. In primary CLL samples, miR-34a, miR-34b/c and DAPK1 methylation was detected in 2.6%, 17.9% and 34.6% of patients at diagnosis respectively. Furthermore, 39.7%, 3.8% and 2.6% patients had methylation of one, two or all three genes respectively. Overall, 46.2% patients had methylation of at least one of these three genes. Besides, miR-34b/c methylation was associated with methylation of miR-34a (P = 0.03) and miR-203 (P = 0.012) in CLL.ConclusionsTaken together, miR-34b/c is a tumor suppressor miRNA frequently methylated, and hence silenced in CLL. Together with DAPK1 methylation, miR-34b/c methylation is implicated in the disruption of the TP53-centered tumor suppressor network. Moreover, the association of miRNA methylation warrants further study.

Dataset Information

A feedback circuit of miR-34a/MDM4/p53 regulates apoptosis in chronic lymphocytic leukemia cells.

Background

Methods

Results

Conclusions

Publications

A feedback circuit of miR-34a/MDM4/p53 regulates apoptosis in chronic lymphocytic leukemia cells.

Similar Datasets

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