Reciprocal modulation of long noncoding RNA EMS and p53 regulates tumorigenesis

p53 plays a central role in tumor suppression. Emerging evidence suggests long noncoding RNA (lncRNA) as an important class of regulatory molecules that control the p53 signaling. Here, we report that the oncogenic lncRNA E2F1 messenger RNA (mRNA) stabilizing factor (EMS) and p53 mutually repress each other’s expression. EMS is negatively regulated by p53. As a direct transcriptional repression target of p53, EMS is surprisingly shown to inhibit p53 expression. EMS associates with cytoplasmic polyadenylation element-binding protein 2 (CPEB2) and thus, disrupts the CPEB2–p53 mRNA interaction. This disassociation attenuates CPEB2-mediated p53 mRNA polyadenylation and suppresses p53 translation. Functionally, EMS is able to exert its oncogenic activities, at least partially, via the CPEB2–p53 axis. Together, these findings reveal a double-negative feedback loop between p53 and EMS, through which p53 is finely controlled. Our study also demonstrates a critical role for EMS in promoting tumorigenesis via the negative regulation of p53.

Poly(C)-binding Protein 2 Regulates the p53 Expression via Interactions with the 5′-Terminal Region of p53 mRNA

The p53 protein is one of the major transcriptional factors which guards cell homeostasis. Here, we showed that poly(C)-binding protein 2 (PCBP2) can bind directly to the 5′ terminus of p53 mRNA by means of electrophoretic mobility shift assay. Binding sites of PCBP2 within this region of p53 mRNA were mapped using Pb2+-induced cleavage and SAXS methods. Strikingly, the downregulation of PCBP2 in HCT116 cells resulted in a lower level of p53 protein under normal and stress conditions. Quantitative analysis of p53 mRNA in PCBP2-downregulated cells revealed a lower level of p53 mRNA under normal conditions suggesting the involvement of PCBP2 in p53 mRNA stabilisation. However, no significant change in p53 mRNA level was observed upon PCBP2 depletion under genotoxic stress. Moreover, a higher level of p53 protein in the presence of rapamycin or doxorubicin and the combination of both antibiotics was noticed in PCBP2-overexpressed cells compared to control cells. These observations indicate the potential involvement of PCBP2 in cap-independent translation of p53 mRNA especially occurring under stress conditions. It has been postulated that the PCBP2 protein is engaged in the enhancement of p53 mRNA stability, probably via interacting with its 3′ end. Our data show that under stress conditions PCBP2 also modulates p53 translation through binding to the 5′ terminus of p53 mRNA. Thus PCBP2 emerges as a double-function factor in the p53 expression.

Research on Mechanism of miRNA-22 Related with Hepatocellular Carcinoma Metastasis for Regulating Process of Tumor Protein P53

The action of miRNA-22 related with HCC metastasis was analyzed in our study and the mechanism of miRNA-22 related with HCC metastasis was discussed. The HCC hep2 cell was transfected with miRNA-22 mimics and miRNA-22 NC instantaneously followed by analysis of cell migration by Transwell assay, cell viability by MTT and clone formation and cell apoptosis by flow cytometry. The action of miRNA-22 mimics and miRNA-22 on the expression of P53 mRNA in HCC Hep2 cell was detected by RT-PCR. The cell activity in miRNA-22 mimics group was significantly elevated compared with miRNA-22 NC group (P < 0.01). Meanwhile, the apoptotic rate, migrated and invaded capacity of HCC cell was significantly elevated (P < 0.01). The expression level of P53 mRNA was reduced (P < 0.01). In conclusion, overexpression of miRNA-22 could restrain the apoptosis of HCC hep2 cell and down-regulated the expression of P53 so as to prompt cell invasion capacity.

The Mechanism of Nano-Particles Intervening Invasion and Metastasis of Lymphoma Based on Autophagy Targeted with miR-36b and Orienteering Analysis on Apoptosis Gene

Whether the expression of gene P53 related with autophagy and apoptosis and action was regulated by miR-36b was discussed in our study. And the action of orienteering nano-particles on intervening invasion and metastasis of lymphoma was analyzed. The normal lymphoid tissue collected from the patients with simple lymphatic hyperplasia was set as control. The lymphoma samples from patients with early indolent lymphoma were collected. The level of mRNA in miR-36b and P53 was detected by PCR. The level of P53 protein and level of mRNA in miR-36b and P53 among normal lymphoid cell, cell strain of low metastatic lymphoma and cell strain of high metastatic lymphoma was compared. They were divided into four groups: miR-NC group, orienteering nano-particles’ group, siRNA-NC group and siRNA-P53 group. The cell proliferative capacity was detected by FCM. The quantity of cell invasion and metastasis was detected by transwell. The expression quantity of P53 mRNA in lymphoma tissue was increased obviously compared with control group. The expression of miR-36b was lower while the expression of P53 was higher along with the later staging of TNM. And the express was related with the staging of TNM. The expression quantity of P53 mRNA in lymphoma cell was higher in normal cell notably. But expression quantity of miR-36b in lymphoma cell was lower in normal cell notably. The decreased of expression of miR-36b and increased of expression of P53 was related with enhancing the ability of invasion and metastasis of lymphoma cells.

p53 mRNA Metabolism Links with the DNA Damage Response

Human cells are subjected to continuous challenges by different genotoxic stress attacks. DNA damage leads to erroneous mutations, which can alter the function of oncogenes or tumor suppressors, resulting in cancer development. To circumvent this, cells activate the DNA damage response (DDR), which mainly involves cell cycle regulation and DNA repair processes. The tumor suppressor p53 plays a pivotal role in the DDR by halting the cell cycle and facilitating the DNA repair processes. Various pathways and factors participating in the detection and repair of DNA have been described, including scores of RNA-binding proteins (RBPs) and RNAs. It has become increasingly clear that p53’s role is multitasking, and p53 mRNA regulation plays a prominent part in the DDR. This review is aimed at covering the p53 RNA metabolism linked to the DDR and highlights the recent findings.

Translation of human Δ133p53 mRNA and its targeting by antisense oligonucleotides complementary to the 5′-terminal region of this mRNA

The p53 protein is expressed as at least twelve protein isoforms. Within intron 4 of the human TP53 gene, a P2 transcription initiation site is located and this transcript encodes two p53 isoforms: Δ133p53 and Δ160p53. Here, the secondary structure of the 5′-terminal region of P2-initiated mRNA was characterized by means of the SHAPE and Pb2+-induced cleavage methods and for the first time, a secondary structure model of this region was proposed. Surprisingly, only Δ133p53 isoform was synthetized in vitro from the P2-initiated p53 mRNA while translation from both initiation codons occurred after the transfection of vector-encoded model mRNA to HCT116 cells. Interestingly, translation performed in the presence of the cap analogue suggested that the cap-independent process contributes to the translation of P2-initiated p53 mRNA. Subsequently, several antisense oligonucleotides targeting the 5′-terminal region of P2-initiated p53 mRNA were designed. The selected oligomers were applied in in vitro translation assays as well as in cell lines and their impact on the Δ133p53 synthesis and on cell viability was investigated. The results show that these oligomers are attractive tools in the modulation of the translation of P2-initiated p53 mRNA through attacking the 5′ terminus of the transcript. Since cell proliferation is also reduced by antisense oligomers that lower the level of Δ133p53, this demonstrates an involvement of this isoform in tumorigenesis.

Quercus infectoria gall extract aids wound healing in a streptozocin-induced diabetic mouse model

Objective: Quercus infectoria galls have commonly been used for different therapeutic purposes. This study was conducted to investigate the effects of topical application of an ointment prepared from Quercus infectoria gall hydroethanolic extract on open wound healing in a streptozocin-induced diabetic BALB/c mouse model. Method: After induction of diabetes, two circular wounds (5mm) were created on the dorsum of the mice which were then divided into three groups. The mice were treated with soft yellow paraffin (control-sham group) and therapeutic doses of 5% and 10% of an ointment prepared from Quercus infectoria, respectively. To evaluate the effects of the therapeutic ointment on the wound healing process, wound area, histological parameters, mRNA levels of vascular endothelial growth factor (VEGF), Bcl-2 and p53, plasma levels of interleukin-6 (IL-6) and tumour necrosis factor (TNF)-α, and tissue antioxidant capacity were investigated. Results: The mice (n=54) were divided into three equal groups. Wound area and concentrations of IL-6 and TNF-α were significantly decreased in both ointment-treated groups compared to the control group (p<0.05). Moreover, angiogenesis, fibroblast distribution per mm2 of wound tissue, collagen deposition, rapid re-epithelialisation, and the expression of VEGF, Bcl-2 and p53 mRNA, were significantly increased (p<0.05). The administration of the ointment reduced malondialdehyde concentration and increased total antioxidant capacity compared with the control group (p<0.05). Conclusion: Our study suggests that an ointment prepared from Quercus infectoria gall hydroethanolic extract accelerated open wound healing in a diabetic animal model by shortening the inflammatory phase, inducing apoptosis, up-regulating the expression of Bcl-2 and p53 mRNA, antioxidant properties and cellular proliferation.

The Correlation Between Tnm and Yy1 and P53 Mrna Expression in Nasopharyngeal Cancer

Nasopharyngeal cancer is the fifth most severe malignant disease in the head and neck in the human body. The main treatment is chemoradio therapy. The protein gene 53 (p53) is a tumor suppressor gene. YinYang1 (YY1) is a transcription factor having an important role in cell cycle control. YY1 can function as an activator, suppressor or initiator of the gene transcription process. This research aims to see the relationship between p53 mRNA gene expression and YY1 mRNA gene expression on the NPC TNM Stage. Materials andmethods cross-sectional research at 20 WHO type 3 NPC in which 3 samples after chemoradiotherapy, 17 non-chemoradio therapy samples consisted of 8 stage two samples, 7 stage three samples and 2 stage four samples. With RT-PCR, YY1 mRNA gene expression and p53 mRNA gene expression were measured, then the T-test was independent of the average chemoradio therapy group. It was concluded, at a higher NPC stage, the level of YY1 mRNA gene expression was relatively higher while p53 expression was lower. Post-chemoradio therapy levels of p53 mRNA gene expression were higher and YY1 expression was lower than in the non-chemoradio therapy group.