Human U3 protein 14a plays an anti-apoptotic role in cancer cells

Genomic Landscape and Potential Regulation of RNA Editing in Drug Resistance

Adenosine-to-inosine RNA editing critically affects the response of cancer therapies. However, comprehensive identification of drug resistance-related RNA editing events and systematic understanding of how RNA editing mediates anticancer drug resistance remain unclear. Here, 7157 differential editing sites (DESs) are identified from 98 127 informative RNA editing sites in tumor tissues, many of which are validated in cancer cell lines. Diverse editing patterns of DESs are discovered in resistant samples, which could not be fully explained by adenosine deaminase acting on RNA enzymes. Some RNA-binding proteins are identified that potentially regulate these editing events. Notably, the DESs are significantly enriched in 3'-untranslated regions (3'-UTRs). The impact of DESs in 3'-UTR on the microRNA (miRNA) regulations is explored, and some triplets (DES, miRNA, and gene) that may contribute to drug resistance are identified. In addition, it is determined that the functions of genes enriched with DESs are associated with drug resistance, such as apoptosis, drug metabolism, and DNA synthesis involved in DNA repair. An online resource (http://www.jianglab.cn/REDR/) to support convenient retrieval of DESs is also built. The findings reveal the landscape and potential regulatory mechanism of RNA editing in drug resistance, providing new therapeutic targets for reversing drug resistance.

Ubiquitination of Nonhistone Proteins in Cancer Development and Treatment

Ubiquitination, a crucial post-translation modification, regulates the localization and stability of the substrate proteins including nonhistone proteins. The ubiquitin-proteasome system (UPS) on nonhistone proteins plays a critical role in many cellular processes such as DNA repair, transcription, signal transduction, and apoptosis. Its dysregulation induces various diseases including cancer, and the identification of this process may provide potential therapeutic targets for cancer treatment. In this review, we summarize the regulatory roles of key UPS members on major nonhistone substrates in cancer-related processes, such as cell cycle, cell proliferation, apoptosis, DNA damage repair, inflammation, and T cell dysfunction in cancer. In addition, we also highlight novel therapeutic interventions targeting the UPS members (E1s, E2s, E3s, proteasomes, and deubiquitinating enzymes). Furthermore, we discuss the application of proteolysis-targeting chimeras (PROTACs) technology as a novel anticancer therapeutic strategy in modulating protein target levels with the aid of UPS.

U three protein 14a (UTP14A) promotes tumour proliferation and metastasis via the PERK/eIF2a/GRP78 signalling pathway in oesophageal squamous cell carcinoma

Metastasis and malignant proliferation are major obstacles to the treatment of oesophageal squamous cell carcinoma (ESCC), and UTP14A is associated with poor prognosis in ESCC. However, its mechanisms have not been fully elucidated. The TCGA and GEO databases were used to identify candidate target genes and possible downstream targets. Then, the effects were determined in vitro and in vivo through knockdown and overexpression techniques, and the mechanism was explored. UTP14A was significantly higher in the tumour tissue of ESCC patients than in normal tissue. Knockdown of UTP14A significantly suppressed the migration and proliferation of ESCC cells. The PERK/eIF2a signalling pathway was positively regulated by UTP14A, and its tumour-promoting effect was further activated by overexpression of UTP14A. In conclusion, UTP14A might promote the proliferation and metastasis of ESCC cells by inducing PERK/eIF2a signalling pathway expression.

Overexpression of U three protein 14a (UTP14a) is associated with poor prognosis of esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive and lethal cancers lacking valid prognostic biomarkers. As an essential component of a large ribonucleoprotein complex, U Three Protein 14a (UTP14a) might play important roles in human tumorigenesis. However, the clinical significance and functions of UTP14a in ESCC still remain unclear.

Methods

From September 2009 to August 2015, 210 patients with ESCC of the thoracic esophagus underwent thoracoscopic esophagectomy in our institute. The corresponding 210 tissue samples and 30 cancer‐distant mucosa (CDM) samples were tested for UTP14a expression by immunohistochemical staining. The long‐term survival was analyzed by the Kaplan–Meier method and Cox proportional hazards regression analyses. CCK8, cell colony formation, cell cycle, apoptosis, cell invasion, and wound healing assays were carried out with ECA109 cells to evaluate the effects of UTP14a on ESCC in vitro.

Results

UTP14a was positively expressed in 88.1% (185/210) of the ESCC samples. UTP14a expression in ESCC was significantly higher than in CDM, as further confirmed by Western blot analysis. High expression of UTP14a in ESCC correlated significantly with tumor invasive depth (pT stage), which predicts poor disease‐free survival and disease‐specific survival, as indicated by the log‐rank test and Cox proportional hazards regression analysis. Additionally, our in vitro experiments further demonstrated that knockdown of UTP14a inhibits cell proliferation and invasion in ECA109 cells.

Conclusions

Our results suggest that UTP14a is aberrantly expressed in ESCC, plays a critical role in cancer progression and could be a potential prognosis predictor of ESCC.

[Expression of hUTP14a in non-small cell lung cancer]

OBJECTIVE

Human U three protein 14a (hUTP14a) facilitates tumorigenesis through promoting p53 and Rb degradation as well as enhancing c-Myc oncogenic activity. Moreover, hUTP14a expression is up-regulated in human hepatocellular cancer and colorectal cancer tissues. In this study, the expression of hUTP14a in non-small cell lung cancer (NSCLC) tissues was evaluated by immunohistochemistry staining (IHC). The relationship between hUTP14a expression levels and the clinical characteristics of the NSCLC patients were analyzed.

METHODS

Lung cancer tissues and the adjacent non-cancerous tissues were collected from 123 cases of NSCLC patients including 53 cases of squamous cell carcinoma (SCC) and 70 cases of adenocarcinoma (ADC), who had accepted surgical resection at Peking University Third Hospital from May 2003 to April 2006. The expression level of hUTP14a was determined by IHC in human NSCLC tissues and the adjacent non-cancerous tissues. The associations between hUTP14a expression and the clinical pathological variables including gender, age, tumor size, histological type, differentiation degree and clinical pathological stage were analyzed using the Pearson's χ² test.

RESULTS

The expression rate of hUTP14a in NSCLC tissues was significantly higher than that in the non-cancerous tissues (37.4% vs. 0, P<0.001). The expressions of hUTP14a in lung ADC and SCC were 48.6% and 20.6%, respectively. The expression rate of hUTP14a in both lung ADC and SCC was significantly higher than that in the adjacent non-cancerous tissues (P<0.001). In addition, the expression rate of hUTP14a in lung ADC was significantly higher than that in SCC (χ²=8.66, P=0.003). Furthermore, the expression rate of hUTP14a in the late pTNM stage of SCC was significantly higher than that in the early pTNM stage of SCC while hUTP14a expression level was not associated with pTNM stage of ADC. No correlation was found between hUTP14a expression and the other clinical pathologic features of the patients.

CONCLUSION

Expression of hUTP14a was up-regulated in NSCLC tissues and was correlated with pTNM stage of SCC, suggesting that hUTP14a might possess a potential as a candidate marker for the early diagnosis screening of NSCLC.