Altered splicing leads to reduced activation of CPEB3 in high-grade gliomas

CPEB2 inhibit cell proliferation through upregulating p21 mRNA stability in glioma

Glioma is the most common primary malignant brain tumor in adults and remains an incurable disease at present. Thus, there is an urgent need for progress in finding novel molecular mechanisms that control the progression of glioma which could be used as therapeutic targets for glioma patients. The RNA binding protein cytoplasmic polyadenylate element-binding protein 2 (CPEB2) is involved in the pathogenesis of several tumors. However, the role of CPEB2 in glioma progression is unknown. In this study, the functional characterization of the role and molecular mechanism of CPEB2 in glioma were examined using a series of biological and cellular approaches in vitro and in vivo. Our work shows CPEB2 is significantly downregulated in various glioma patient cohorts. Functional characterization of CPEB2 by overexpression and knockdown revealed that it inhibits glioma cell proliferation and promotes apoptosis. CPEB2 exerts an anti-tumor effect by increasing p21 mRNA stability and inducing G1 cell cycle arrest in glioma. Overall, this work stands as the first report of CPEB2 downregulation and involvement in glioma pathogenesis, and identifies CPEB2 as an important tumor suppressor gene through targeting p21 in glioma, which revealed that CPEB2 may become a promising predictive biomarker for prognosis in glioma patients.

MiR-9-5p promotes cell proliferation and migration of hepatocellular carcinoma by targeting CPEB3

Objective: This study aimed to observe the effect of miR-9-5p and CPEB3 on hepatocellular carcinoma (HCC) cells, and investigate the underlying targeting regulatory mechanism. Materials & methods: Various experiments like CCK-8, colony formation assay, wound healing assay and Transwell were performed for cancer cell activities detection, including cell proliferation, growth activity, migration and invasion. Results: MiR-9-5p was found to be highly expressed in HCC cells, while CPEB3 was poorly expressed (p < 0.05). The overexpression of miR-9-5p and the silencing of CPEB3 both could significantly promote cell proliferation, migration and invasion (p < 0.05). In addition, miR-9-5p could target to downregulate CPEB3 expression, thus accelerating cell proliferation, migration, invasion and epithelial-mesenchymal transition process in HCC. Conclusion: MiR-9-5p can target CPEB3, thereby promoting cell proliferation, migration and invasion in HCC. The axis of miR-9-5p/CPEB3 is expected to become a potential therapeutic target beneficial for HCC patients.

Decreased Expression of CPEB3 Predicts a Poor Prognosis in Patients with Melanoma: A Study Based on TCGA Data

Aim

Cytoplasmic polyadenylation element-binding protein 3 (CPEB3) has been acknowledged as a tumor-suppressive gene in several cancers; however, there are few reports on the clinical significance of CPEB3 in melanoma. The aim of this study was to investigate the role of CPEB3 in predicting the prognosis of melanoma patients.

Methods

The association of CPEB3 expression and clinical pathologic features was performed using The Cancer Genome Atlas (TCGA) data set. The role of CPEB3 expression in prognosis was also analyzed. In addition, CPEB3 expression-related pathways were enriched by gene set enrichment analysis (GSEA). Association analysis of CPEB3 gene expression and immune infiltration was performed by ssGSEA.

Results

The mRNA was significantly less in melanoma than in normal tissues (p < 0.001). The decrease in CPEB3 expression in melanoma was significantly correlated with T staging (p < 0.001), clinical staging (p = 0.029), melanoma Clark level (p = 0.014), and melanoma ulceration (p = 0.003), while it was marginally significant in N staging (p = 0.089). Melanoma with low CPEB3 expression was associated with worse OS (overall survival), progression-free survival (PFS), and disease-specific survival (DSS) than in that with high expression. In the univariate analysis, expression of CPEB3, melanoma ulceration, Clark level of melanoma, age, clinical stage, T stage, and N stage were correlated with OS (p < 0.05). Further analysis by multivariate Cox regression showed that N stage (p = 0.029), melanoma ulceration (p = 0.004), and CPEB3 expression (p < 0.001) were independent prognostic factors of OS in melanoma. Moreover, GSEA showed that several pathways were enriched in CPEB3, such as PD1 signaling, CTLA4 pathway, CTCF pathway, CHEMOKIN signaling, VEGF signaling, and JAK-STAT pathway. CPEB3 was significantly correlated with the infiltration level of B cells (p < 0.001), T cells (p < 0.001), T helper cells (p < 0.001), and central memory T (Tcm) cells (p < 0.001).

Conclusion

CPEB3 may be a potential prognostic marker in melanoma with poor survival. Moreover, PD1 signaling, CTLA4 pathway, CTCF pathway, CHEMOKIN signaling, VEGF signaling, and JAK-STAT pathway may be the key pathway regulated by CPEB3. Moreover, the expression of CPEB3 in melanoma is related to the level of immune infiltration.

Interactome of miRNAs and transcriptome of human umbilical cord endothelial cells exposed to short-term simulated microgravity

Adaptation of humans in low gravity conditions is a matter of utmost importance when efforts are on to a gigantic leap in human space expeditions for tourism and formation of space colonies. In this connection, cardiovascular adaptation in low gravity is a critical component of human space exploration. Deep high-throughput sequencing approach allowed us to analyze the miRNA and mRNA expression profiles in human umbilical cord vein endothelial cells (HUVEC), cultured under gravity (G), and stimulated microgravity (MG) achieved with a clinostat. The present study identified totally 1870 miRNAs differentially expressed in HUVEC under MG condition when compared to the cells subjected to unitary G conditions. The functional association of identified miRNAs targeting specific mRNAs revealed that miRNAs, hsa-mir-496, hsa-mir-151a, hsa-miR-296-3p, hsa-mir-148a, hsa-miR-365b-5p, hsa-miR-3687, hsa-mir-454, hsa-miR-155-5p, and hsa-miR-145-5p differentially regulated the genes involved in cell adhesion, angiogenesis, cell cycle, JAK-STAT signaling, MAPK signaling, nitric oxide signaling, VEGF signaling, and wound healing pathways. Further, the q-PCR based experimental studies of upregulated and downregulated miRNA and mRNAs demonstrate that the above reported miRNAs influence the cell proliferation and vascular functions of the HUVEC in MG conditions effectively. Consensus on the interactome results indicates restricted fluctuations in the transcriptome of the HUVEC exposed to short-term MG that could lead to higher levels of endothelial functions like angiogenesis and vascular patterning.

Identification of Prognostic Signatures of Alternative Splicing in Glioma

Alternative splicing (AS) is a ubiquitous mechanism in which pre-mRNA can be spliced into divergent variants and involved in carcinogenesis and progression in several cancers. In the present study, we systematically profiled prognostic AS signatures involving both low grade glioma (LGG) and glioblastoma (GBM) and investigated the association of AS signatures with tumor grade and IDH1 status in glioma. Percent spliced in (PSI) values and corresponding clinical data were obtained from TCGA SpliceSeq and TCGA data portal, respectively. Prognostic AS signatures were identified using univariate and stepwise multivariate Cox regression. Heatmap analysis was performed based on prognostic AS signatures. A prognostic signature was established with 69 and 88 AS events, including specific splicing events of MUTYH, STEAP3, and CTNNB1, in LGG and GBM cohorts, respectively. The area under the curve (AUC) of the prediction model was 0.968 at 2000 days of overall survival (OS) in the LGG cohort and 0.966 at 450 days of OS in the GBM cohort. In addition, these prognostic AS signatures could complement current molecular classification, such as IDH1 mutation, 1p/19q codeletion, and ATRX loss, of glioma and further identify potential subgroups of glioma with the same molecular features. In conclusion, our study systematically profiled prognostic AS events involving both low grade glioma and glioblastoma for the first time, which also shed light on the crosstalk between AS signatures and molecular features of glioma.

LncRNA SUMO1P3 promotes proliferation and inhibits apoptosis in colorectal cancer by epigenetically silencing CPEB3

Colorectal cancer (CRC) is a prevalent malignancy characterized with high morbidity and death rate. Due to late diagnosis, most CRC patients missed the proper timing for radical operation, which led to the high mortality in CRC. Therefore, identifying new prognostic and therapeutic targets is important. Long non-coding RNAs are reported as essential regulators for tumor progression, including in CRC. LncRNA SUMO1P3 has been documented as an oncogene promoting proliferation, cell cycle, and metastasis in several cancers, but its role in CRC has never been unveiled. The purpose of our study is to interrogate the functions and mechanism of SUMO1P3 in colorectal cancer. We validated the upregulation and the prognostic significance of SUMO1P3 in CRC. The loss-of-function assays suggested that SUMO1P3 provoked CRC cell proliferative ability, and retarded apoptotic ability. Cytoplasmic polyadenylation element binding protein 3 (CPEB3) has been newly acknowledged as a tumor suppressive gene in several cancers, and has been revealed to present low expression in CRC. We predicted through UCSC database and validated by ChIP assay that EZH2, a crucial regulator of trimethylation of histone H3 at lysine 27 (H3K27me3), bound to CPEB3 promoter. Further, we validated that SUMO1P3 epigenetically repressed CPEB3 through EZH2. Finally, rescue assays indicated that SUMO1P3 provoked proliferation, cell cycle, and retarded apoptosis through CPEB3. Consequently, current study showed that lncRNA SUMO1P3 promoted cell proliferative ability and inhibited apoptotic ability in CRC by epigenetically silencing CPEB3, providing a novel prognostic marker for CRC patients.