Inhibition of ubiquitin specific protease 17 restrains prostate cancer proliferation by regulation of epithelial-to-mesenchymal transition (EMT) via ROS production

Establishment of a prognosis predictive model for liver cancer based on expression of genes involved in the ubiquitin-proteasome pathway

BACKGROUND

The ubiquitin-proteasome pathway (UPP) has been proven to play important roles in cancer.

AIM

To investigate the prognostic significance of genes involved in the UPP and develop a predictive model for liver cancer based on the expression of these genes.

METHODS

In this study, UPP-related E1, E2, E3, deubiquitylating enzyme, and proteasome gene sets were obtained from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, aiming to screen the prognostic genes using univariate and multivariate regression analysis and develop a prognosis predictive model based on the Cancer Genome Atlas liver cancer cases.

RESULTS

Five genes (including autophagy related 10, proteasome 20S subunit alpha 8, proteasome 20S subunit beta 2, ubiquitin specific peptidase 17 like family member 2, and ubiquitin specific peptidase 8) were proven significantly correlated with prognosis and used to develop a prognosis predictive model for liver cancer. Among training, validation, and Gene Expression Omnibus sets, the overall survival differed significantly between the high-risk and low-risk groups. The expression of the five genes was significantly associated with immunocyte infiltration, tumor stage, and postoperative recurrence. A total of 111 differentially expressed genes (DEGs) were identified between the high-risk and low-risk groups and they were enriched in 20 and 5 gene ontology and KEGG pathways. Cell division cycle 20, Kelch repeat and BTB domain containing 11, and DDB1 and CUL4 associated factor 4 like 2 were the DEGs in the E3 gene set that correlated with survival.

CONCLUSION

We have constructed a prognosis predictive model in patients with liver cancer, which contains five genes that associate with immunocyte infiltration, tumor stage, and postoperative recurrence.

Molecular predictors of metastasis in patients with prostate cancer

INTRODUCTION

Prostate cancer is a serious threat to the health of older adults worldwide. The quality of life and survival time of patients sharply decline once metastasis occurs. Thus, early screening for prostate cancer is very advanced in developed countries. The detection methods used include Prostate-specific antigen (PSA) detection and digital rectal examination. However, the lack of universal access to early screening in some developing countries has resulted in an increased number of patients presenting with metastatic prostate cancer. In addition, the treatment methods for metastatic and localized prostate cancer are considerably different. In many patients, early-stage prostate cancer cells often metastasize due to delayed observation, negative PSA results, and delay in treatment time. Therefore, the identification of patients who are prone to metastasis is important for future clinical studies.

AREAS COVERED

this review introduced a large number of predictive molecules related to prostate cancer metastasis. These molecules involve the mutation and regulation of tumor cell genes, changes in the tumor microenvironment, and the liquid biopsy.

EXPERT OPINION

In next decade, PSMA PET/CT and liquid biopsy will be the excellent predicting tools, while ¹⁷⁷ Lu- PSMA-RLT will be showed excellent anti-tumor efficacy in mPCa patients.

C4orf19 inhibits colorectal cancer cell proliferation by competitively binding to Keap1 with TRIM25 via the USP17/Elk-1/CDK6 axis

Colorectal cancer (CRC) is one of the most common malignant tumors in the gastrointestinal tract, and has been attracted a great deal attention and extensive investigation due to its high morbidity and mortality rates. The C4orf19 gene encodes a protein with uncharacterized function. Our preliminary exploration of the TCGA database indicated that C4orf19 is markedly downregulated in CRC tissues in comparison to that observed in normal colonic tissues, suggesting its potential association with CRC behaviors. Further studies showed a significant positive correlation between C4orf19 expression levels and CRC patient prognosis. Ectopic expression of C4orf19 inhibited the growth of CRC cells in vitro and tumorigenic ability in vivo. Mechanistic studies showed that C4orf19 binds to Keap1 at near the Lys615, which prevents the ubiquitination of Keap1 by TRIM25, thus protecting the Keap1 protein from degradation. The accumulated Keap1 results in USP17 degradation and in turn leading to the degradation of Elk-1, further attenuates its regulated CDK6 mRNA transcription and protein expression, as well as its mediated proliferation of CRC cells. Collectively, the present studies characterize function of C4orf19 as a tumor suppressor for CRC cell proliferation by targeting Keap1/USP17/Elk-1/CDK6 axis.

Ubiquitin specific peptidases and prostate cancer

Protein ubiquitination is an important post-translational modification mechanism, which regulates protein stability and activity. The ubiquitination of proteins can be reversed by deubiquitinating enzymes (DUBs). Ubiquitin-specific proteases (USPs), the largest DUB subfamily, can regulate cellular functions by removing ubiquitin(s) from the target proteins. Prostate cancer (PCa) is the second leading type of cancer and the most common cause of cancer-related deaths in men worldwide. Numerous studies have demonstrated that the development of PCa is highly correlated with USPs. The expression of USPs is either high or low in PCa cells, thereby regulating the downstream signaling pathways and causing the development or suppression of PCa. This review summarized the functional roles of USPs in the development PCa and explored their potential applications as therapeutic targets for PCa.

Redox regulation of DUBs and its therapeutic implications in cancer

Reactive oxygen species (ROS) act as a double-edged sword in cancer, where low levels of ROS are beneficial but excessive accumulation leads to cancer progression. Elevated levels of ROS in cancer are counteracted by the antioxidant defense system. An imbalance between ROS generation and the antioxidant system alters gene expression and cellular signaling, leading to cancer progression or death. Post-translational modifications, such as ubiquitination, phosphorylation, and SUMOylation, play a critical role in the maintenance of ROS homeostasis by controlling ROS production and clearance. Recent evidence suggests that deubiquitinating enzymes (DUBs)-mediated ubiquitin removal from substrates is regulated by ROS. ROS-mediated oxidation of the catalytic cysteine (Cys) of DUBs, leading to their reversible inactivation, has emerged as a key mechanism regulating DUB-controlled cellular events. A better understanding of the mechanism by which DUBs are susceptible to ROS and exploring the ways to utilize ROS to pharmacologically modulate DUB-mediated signaling pathways might provide new insight for anticancer therapeutics. This review assesses the recent findings regarding ROS-mediated signaling in cancers, emphasizes DUB regulation by oxidation, highlights the relevant recent findings, and proposes directions of future research based on the ROS-induced modifications of DUB activity.

The role of the deubiquitinating enzyme DUB3/USP17 in cancer: a narrative review

The balance between ubiquitination and deubiquitination is critical for the degradation, transport, localization, and activity of proteins. Deubiquitinating enzymes (DUBs) greatly contribute to the balance of ubiquitination and deubiquitination, and they have been widely studied due to their fundamental role in cancer. DUB3/ubiquitin-specific protease 17 (USP17) is a type of DUB that has attracted much attention in cancer research. In this review, we summarize the biological functions and regulatory mechanisms of USP17 in central nervous system, head and neck, thoracic, breast, gastrointestinal, genitourinary, and gynecologic cancers as well as bone and soft tissue sarcomas, and we provide new insights into how USP17 can be used in the management of cancer.

USP17-mediated de-ubiquitination and cancer: Clients cluster around the cell cycle

Eukaryotic cells perform a range of complex processes, some essential for life, others specific to cell type, all of which are governed by post-translational modifications of proteins. Among the repertoire of dynamic protein modifications, ubiquitination is arguably the most arcane and profound due to its complexity. Ubiquitin conjugation consists of three main steps, the last of which involves a multitude of target-specific ubiquitin ligases that conjugate a range of ubiquitination patterns to protein substrates with diverse outcomes. In contrast, ubiquitin removal is catalysed by a relatively small number of de-ubiquitinating enzymes (DUBs), which can also display target specificity and impact decisively on cell function. Here we review the current knowledge of the intriguing ubiquitin-specific protease 17 (USP17) family of DUBs, which are expressed from a highly copy number variable gene that has been implicated in multiple cancers, although available evidence points to conflicting roles in cell proliferation and survival. We show that key USP17 substrates populate two pathways that drive cell cycle progression and that USP17 activity serves to promote one pathway but inhibit the other. We propose that this arrangement enables USP17 to stimulate or inhibit proliferation depending on the mitogenic pathway that predominates in any given cell and may partially explain evidence pointing to both oncogenic and tumour suppressor properties of USP17.

Inhibition of USP15 Prevent Glutamate-Induced Oxidative Damage by Activating Nrf2/HO-1 Signaling Pathway in HT22 Cells

Oxidative stress has been identified as the significant mediator in epilepsy, which is a chronic disorder in central nervous system. About 30% of epilepsy patients are refractory to antiepileptic drug treatment. However, the underlying mechanism of oxidative damage in epilepsy needs further investigation. In our study, we first find that ubiquitin-specific peptidase 15 (USP15) expression was upregulated in a pentylenetetrazole (PTZ) kindled rat model of epilepsy. Silencing USP15 protected against glutamate-mediated neuronal cell death, and inhibited the high expression levels of cleaved caspase-3. Knockout of USP15 significantly reduced intracellular reactive oxygen species (ROS) levels and enhanced superoxide dismutase (SOD) activity in HT22 cells under the exposure to glutamate treatment. Furthermore, USP15 inhibition induced nuclear factor erythroid-derived 2-related factor2 (Nrf2) nuclear translocation and promoted protein expression level of heme oxygenase (HO-1). Taken together, our findings first reveal a role of USP15 in the pathogenesis of epilepsy, and silencing USP15 in vitro protects against glutamate-mediated cytotoxicity in HT22 cells. Pharmacological inhibition of USP15 may alleviate epileptic seizures via fighting against oxidative damage, providing a novel antiepileptic target.

miR-200b/c-RAP1B axis represses tumorigenesis and malignant progression of papillary thyroid carcinoma through inhibiting the NF-κB/Twist1 pathway

Papillary thyroid carcinoma (PTC) is a common endocrine malignancy with an increasing occurrence and recurrence. MicroRNAs (miRNAs) have been widely acknowledged to be participated in human cancers. However, how these miRNAs exert roles and potential mechanisms in PTC regulatory networks is still lacking. The purpose of our study lies in discovering the regulatory basis of miR-200b/c and Rap1b for PTC tumorigenesis and malignant progression, as well as the underlying molecular mechanisms. Herein, miR-200b/c expression was sharply dropped and Rap1b expression was up-regulated in PTC cells and tissues samples when compared to normal thyroid epithelial cells and normal tissues. miR-200b/c targeted Rap1 directly and negatively regulated its expression. miR-200b/c overexpression suppressed proliferative, colony forming, migratory and invasive capabilities and EMT as well as elevated apoptosis of PTC cells through inhibiting Rap1b. Furthermore, xenograft experiments showed miR-200b/c overexpression constrained growth of PTC xenograft and EMT. miR-200b/c inhibited NF-κB/Twist1 signals via regulating the Rap1b expression in cells and animal models. Taken together, our study suggested that upregulation of miR-200b/c-RAP1B axis constrained PTC cell proliferation, invasion, migration and EMT. Also, the upregulation of miR-200b/c-RAP1B leaded to elevated apoptosis through inhibiting the NF-κB/Twist1 pathway, thus inhibiting PTC tumorigenesis and malignant progression.