High expression of cytoplasmic polyadenylation element-binding protein 4 correlates with poor prognosis of patients with colorectal cancer

Immune translational control by CPEB4 regulates intestinal inflammation resolution and colorectal cancer development

Upon tissue injury, cytokine expression reprogramming transiently remodels the inflammatory immune microenvironment to activate repair processes and subsequently return to homeostasis. However, chronic inflammation induces permanent changes in cytokine production which exacerbate tissue damage and may even favor tumor development. Here, we address the contribution of post-transcriptional regulation, by the RNA-binding protein CPEB4, to intestinal immune homeostasis and its role in inflammatory bowel diseases (IBD) and colorectal cancer (CRC) development. We found that intestinal damage induces CPEB4 expression in adaptive and innate immune cells, which is required for the translation of cytokine mRNA(s) such as the one encoding interleukin-22. Accordingly, CPEB4 is required for the development of gut-associated lymphoid tissues and to maintain intestinal immune homeostasis, mediating repair and remodeling after acute inflammatory tissue damage and promoting the resolution of intestinal inflammation. CPEB4 is chronically overexpressed in inflammatory cells in patients with IBD and in CRC, favoring tumor development.

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CPEB4 is overexpressed in Th17 and ILC3 cells upon intestinal barrier damage

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CPEB4 is required for Il-22 mRNA translation and IL-22 expression

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CPEB4 promotes tissue repair in acute transient inflammation

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In chronic inflammation CPEB4 exacerbates intestinal pathology and promotes tumor growth

Processing body (P-body) and its mediators in cancer

In recent years, processing bodies (P-bodies) formed by liquid-liquid phase separation, have attracted growing scientific attention due to their involvement in numerous cellular activities, including the regulation of mRNAs decay or storage. These cytoplasmic dynamic membraneless granules contain mRNA storage and decay components such as deadenylase and decapping factors. In addition, different mRNA metabolic regulators, including m⁶A readers and gene-mediated miRNA-silencing, are also associated with such P-bodies. Cancerous cells may profit from these mRNA decay shredders by up-regulating the expression level of oncogenes and down-regulating tumor suppressor genes. The main challenges of cancer treatment are drug resistance, metastasis, and cancer relapse likely associated with cancer stem cells, heterogeneity, and plasticity features of different tumors. The mRNA metabolic regulators based on P-bodies play a great role in cancer development and progression. The dysregulation of P-bodies mediators affects mRNA metabolism. However, less is known about the relationship between P-bodies mediators and cancerous behavior. The current review summarizes the recent studies on P-bodies mediators, their contribution to tumor development, and their potential in the clinical setting, particularly highlighting the P-bodies as potential drug-carriers such as exosomes to anticancer in the future.

Investigation of the expression levels of CPEB4, APC, TRIP13, EIF2S3, EIF4A1, IFNg, PIK3CA and CTNNB1 genes in different stage colorectal tumors

Background/aim

The aim of the study is to assess expression levels of CPEB4, APC, TRIP13, EIF2S3, EIF4A1, IFNg, PIK3CA and CTNNB1 genes in tumors and peripheral bloods of colorectal cancer patients in stages I–IV.

Materials and methods

The mRNA levels of the genes were determined in tumor tissues and peripheral blood samples of 45 colorectal cancer patients and colon tissues and peripheral blood samples of 5 healthy individuals. Real-time polymerase chain reaction method was used for the analysis.

Results

The mRNA level of the CPEB4 gene was significantly downregulated in colorectal tumor tissues and was upregulated in the peripheral blood of colorectal cancer patients relative to the controls (P < 0.05). APC mRNA level was significantly downregulated in tissues and upregulated in the peripheral blood (P < 0.05). TRIP13 mRNA level was upregulated in peripheral blood and also significantly upregulated in colorectal tumor tissues (P < 0.05). EIF2S3 mRNA level was upregulated in tissues and also significantly upregulated in peripheral blood (P < 0.05). PIK3CA mRNA level was downregulated in tissues and upregulated in peripheral blood. EIF4A1 mRNA level was downregulated in tissues and significantly upregulated in peripheral blood (P < 0.05). CTNNB1 mRNA level was downregulated in tissues and upregulated in peripheral blood. IFNg mRNA level was upregulated in both colorectal cancer tumor tissues and peripheral blood.

Conclusion:

TRIP13 and CPEB4 mRNA up regulation in the peripheral blood of patients with colorectal cancer may be a potential target for early stage diagnosis. In addition to this evaluation, although there is not much study on EIF2S3 and EIF4A1 mRNA changes in cases with colorectal cancer, upregulation in peripheral blood draws attention in our study. These data will shed light on the new comprehensive studies.

Post-transcriptional Regulation of Colorectal Cancer: A Focus on RNA-Binding Proteins

Colorectal cancer (CRC) is a major health problem with an estimated 1. 8 million new cases worldwide. To date, most CRC studies have focused on DNA-related aberrations, leaving post-transcriptional processes under-studied. However, post-transcriptional alterations have been shown to play a significant part in the maintenance of cancer features. RNA binding proteins (RBPs) are uprising as critical regulators of every cancer hallmark, yet little is known regarding the underlying mechanisms and key downstream oncogenic targets. Currently, more than a thousand RBPs have been discovered in humans and only a few have been implicated in the carcinogenic process and even much less in CRC. Identification of cancer-related RBPs is of great interest to better understand CRC biology and potentially unveil new targets for cancer therapy and prognostic biomarkers. In this work, we reviewed all RBPs which have a role in CRC, including their control by microRNAs, xenograft studies and their clinical implications.

CPEB4 regulates glioblastoma cell proliferation and predicts poor outcome of patients

OBJECTIVE

Cytoplasmic polyadenylation element binding protein 4 (CPEB4) is a regulator of gene expression at transcriptional level and has been reported to be associated with biological malignancy in cancers. However, little was known about the correlation between CPEB4 and glioblastoma cell proliferation and the prognostic significance in patients. Our aim was to investigate the functional role and prognostic value of CPEB4 in glioblastoma.

PATIENTS AND METHODS

We determined the expression of CPEB4 protein using immunohistochemistry in tissue microarrays containing 278 glioma patients (including 98 primary glioblastomas) and evaluated its association with pathological grades and clinical outcome by univariate and multivariate analyses. And then, lentiviral-mediated RNAi targeting CPEB4 was utilized to study the role of CPEB4 in glioblastoma cell proliferation.

RESULTS

In our cohort, CPEB4 expression was positively related to glioma pathological grade (p < 0.01) and elevated in glioblastoma (p < 0.01). High expression of CPEB4 was associated with significantly poor prognosis, and could be identified as an independent risk factor for overall survival (OS) and progression-free survival (PFS) of glioblastoma patients (hazard ratio (HR) = 1.730, p = 0.014 and HR = 1.877, p = 0.004, respectively). In vitro studies further showed that downregulation of CPEB4 significantly reduced the growth rate of T98G and U251 cells comparing with the controls.

CONCLUSION

Our study indicated that increased expression of CPEB4 in primary glioblastoma is a novel biomarker for predicting poor outcome of patients and suppression of CPEB4 inhibit tumor cell proliferation, suggesting a potential therapeutic target for glioblastoma.