Downregulation of ubiquitin-specific protease 2 possesses prognostic and diagnostic value and promotes the clear cell renal cell carcinoma progression

Hsa_circ_0086414/transducer of ERBB2 (TOB2) axis-driven lipid elimination and tumor suppression in clear cell renal cell cancer via perilipin 3

BACKGROUND

Renal cell cancer (RCC) is characterized by abnormal lipid accumulation. However, the specific mechanism by which such lipid deposition is eliminated remains unclear. Circular RNAs (circRNAs) widely regulate various biological processes, but the effect of circRNAs on lipid metabolism in cancers, especially clear cell renal cell carcinoma (ccRCC), remains poorly understood.

METHODS

The downregulated circRNA, hsa_circ_0086414, was identified from high-throughput RNA-sequencing data of human ccRCC and pair-matched normal tissues. The target relationship between circRNA_0086414 and miR-661, and the transducer of ERBB2 (TOB2) was predicted using publicly available software programs and verified by luciferase reporter assays. The clinical prognostic value of TOB2 was evaluated by bioinformatic analysis. The expression levels of circRNA_0086414, miR-661, TOB2, and perilipin 3 (PLIN3) were measured by quantitative reverse-transcription polymerase chain reaction or western blot analysis. Cell Counting Kit-8, transwell assays, and xenograft models were employed to assess the biological behaviors of the hsa_circ_0086414/TOB2 axis. Oil Red staining and triglyceride assay was conducted to assess lipid deposition.

RESULTS

Herein, we identified a downregulated circRNA, hsa_circ_0086414. Functionally, the restored hsa_circ_0086414 inhibited ccRCC proliferation, metastasis, and lipid accumulation in vitro and in vivo. Furthermore, the downregulated TOB2 predicted adverse prognosis and promoted cancer progression and lipid deposition in ccRCC. Mechanically, the binding of hsa_circ_0086414 to miR-661, as a miRNA sponge, upregulates the expression of TOB2, wielding an anti-oncogene effect. Importantly, the restored hsa_circ_0086414/TOB2 axis significantly contributed to the elimination of lipid deposition by inhibiting the lipid metabolism regulator PLIN3 in ccRCC cells.

CONCLUSIONS

Our data highlight the importance of the hsa_circ_0086414/TOB2/PLIN3 axis as a tumor suppressor and lipid eliminator in ccRCC. The positive modulation of the hsa_circ_0086414/TOB2 axis might lead to the development of novel treatment strategies for ccRCC.

Emerging roles of deubiquitinating enzymes in actin cytoskeleton and tumor metastasis

BACKGROUND

Metastasis accounts for the majority of cancer-related deaths. Actin dynamics and actin-based cell migration and invasion are important factors in cancer metastasis. Metastasis is characterized by actin polymerization and depolymerization, which are precisely regulated by molecular changes involving a plethora of actin regulators, including actin-binding proteins (ABPs) and signalling pathways, that enable cancer cell dissemination from the primary tumour. Research on deubiquitinating enzymes (DUBs) has revealed their vital roles in actin dynamics and actin-based migration and invasion during cancer metastasis.

CONCLUSION

Here, we review how DUBs drive tumour metastasis by participating in actin rearrangement and actin-based migration and invasion. We summarize the well-characterized and essential actin cytoskeleton signalling molecules related to DUBs, including Rho GTPases, Src kinases, and ABPs such as cofilin and cortactin. Other DUBs that modulate actin-based migration signalling pathways are also discussed. Finally, we discuss and address therapeutic opportunities and ongoing challenges related to DUBs with respect to actin dynamics.

Targeting the deubiquitinase USP2 for malignant tumor therapy (Review)

The ubiquitin‑proteasome system is a major degradation pathway for >80% of proteins in vivo. Deubiquitylases, which remove ubiquitinated tags to stabilize substrate proteins, are important components involved in regulating the degradation of ubiquitinated proteins. In addition, they serve multiple roles in tumor development by participating in physiological processes such as protein metabolism, cell cycle regulation, DNA damage repair and gene transcription. The present review systematically summarized the role of ubiquitin‑specific protease 2 (USP2) in malignant tumors and the specific molecular mechanisms underlying the involvement of USP2 in tumor‑associated pathways. USP2 reverses ubiquitin‑mediated degradation of proteins and is involved in aberrant proliferation, migration, invasion, apoptosis and drug resistance of tumors. Additionally, the present review summarized studies reporting on the use of USP2 as a therapeutic target for malignancies such as breast, liver, ovarian, colorectal, bladder and prostate cancers and glioblastoma and highlights the current status of pharmacological research on USP2. The clinical significance of USP2 as a therapeutic target for malignant tumors warrants further investigation.

Dysregulation and oncogenic activities of ubiquitin specific peptidase 2a in the pathogenesis of hepatocellular carcinoma

Ubiquitin specific peptidase 2a (USP2a) plays critical roles in protein degradation and other cellular activities. Currently, our understanding on USP2a dysregulation in subjects with hepatocellular carcinoma (HCC) and its roles in HCC pathogenesis is limited. In this study, we found that USP2a mRNA and protein levels were significantly upregulated in HCC tumors from both human and mice. USP2a overexpression in HepG2 and Huh 7 cells significantly increased cell proliferation while inhibition of USP2a activity by chemical inhibitor or stable knockout of USP2 by CRISPR markedly reduced cell proliferation. In addition, USP2a overexpression significantly augmented the resistance while knockout of USP2a markedly increased the susceptibility of HepG2 cells to bile acid-induced apoptosis and necrosis. Consistent with the oncogenic activities detected in vitro, overexpression of USP2a promoted de novo HCC development in mice with significantly increased tumor occurrence rates, tumor sizes and liver/body ratios. Further investigations with unbiased co-immunoprecipitation (Co-IP)-coupled proteomic analysis and Western blot identified novel USP2a target proteins involved in cell proliferation, apoptosis, and tumorigenesis. Analysis of those USP2a target proteins revealed that USP2a's oncogenic activities are mediated through multiple pathways, including modulating protein folding and assembling through regulating protein chaperones/co-chaperones HSPA1A, DNAJA1 and TCP1, promoting DNA replication and transcription through regulating RUVBL1, PCNA and TARDBP, and altering mitochondrial apoptotic pathway through regulating VDAC2. Indeed, those newly identified USP2a target proteins were markedly dysregulated in HCC tumors. In summary, USP2a was upregulated in HCC subjects and acted as an oncogene in the pathogenesis of HCC through multiple downstream pathways. The findings provided molecular and pathogenesis bases for developing interventions to treat HCC by targeting USP2a or its downstream pathways.

CircPTK2/PABPC1/SETDB1 axis promotes EMT-mediated tumor metastasis and gemcitabine resistance in bladder cancer

Bladder cancer (BCa), characterized by high invasion, metastasis, recurrence, and chemoresistance, is one of the most prevalent urologic malignant tumors. Recent studies have highlighted the potential impact of the circRNAs-protein complex in tumorigenesis. However, the mechanisms by which the circRNAs-protein complex regulates BCa metastasis and chemoresistance remain elusive. Herein, we identified an upregulated circRNA, circPTK2, which could regulate SETDB1 expression by analyzing the transcriptome by RNA-sequencing. Importantly, using circRNA pulldown assay and RNA-binding protein immunoprecipitation, we identified PABPC1 as a robust novel interacting protein of circPTK2. Mechanistically, circPTK2 could bind to PABPC1 and enhance its ability to stabilize SETDB1 mRNA, thereby specifically promoting SETDB1 expression and facilitating SETDB1-mediated epithelial-mesenchymal transition (EMT). Functionally, overexpression of the circPTK2-SETDB1 axis markedly promoted migration, invasion, and gemcitabine resistance in vitro and enhanced lymph node metastasis in vivo. Collectively, our findings clarified a hitherto unexplored mechanism of the circPTK2/PABPC1/SETDB1 axis in EMT-mediated tumor metastasis and gemcitabine resistance in BCa.

Bortezomib advanced mechanisms of action in multiple myeloma, solid and liquid tumors along with its novel therapeutic applications

Bortezomib (BTZ) is a first-in-class reversible and selective proteasome inhibitor. It inhibits the ubiquitin proteasome pathway that leads to the degradation of many intracellular proteins. Initially, BTZ was FDA approved for the treatment of refractory or relapsed multiple myeloma (MM) in 2003. Later, its usage was approved for patients with previously untreated MM. In 2006, BTZ was approved for the treatment of relapsed or refractory Mantle Cell Lymphoma (MCL) and, in 2014, for previously untreated MCL. BTZ has been extensively studied either alone or in combination with other drugs for the treatment of different liquid tumors especially in MM. However, limited data evaluated the efficacy and safety of using BTZ in patients with solid tumors. In this review, we will discuss the advanced and novel mechanisms of action of BTZ documented in MM, solid tumors and liquid tumors. Moreover, we will shed the light on the newly discovered pharmacological effects of BTZ in other prevalent diseases.

SLC17A9-PTHLH-EMT axis promotes proliferation and invasion of clear renal cell carcinoma

SLC17A9 is a vesicular ATP transport protein that plays an important role in determining cell functions and the onset and progression of different diseases. In this study, SLC17A9 was initially identified as a potential diagnostic and prognostic risk biomarker for clear cell renal cell carcinoma (ccRCC). Then, the aberrant expression levels of SLC17A9 were confirmed in both the cell lines and clinical tissues. Mechanistically, SLC17A9 could upregulate the expression of PTHLH, thus promoting epithelial-mesenchymal transition (EMT) in ccRCC. Functionally, SLC17A9 knockdown inhibited the proliferation, migration, and invasion activity of renal cancer cells, whereas its overexpression led to stronger cell viability and more malignant phenotype in vitro. The overexpression of SLC17A9 in vivo could significantly contribute to the growth of tumors. Finally, we found that SLC17A9 might be related to the drug resistance of vorinostat. Cumulatively, this study demonstrated that the SLC17A9-PTHLH-EMT axis could promote the progression of ccRCC.

KDELR2-KIF20A axis facilitates bladder cancer growth and metastasis by enhancing Golgi-mediated secretion

Background

Bladder cancer (BCa) is a fatal form of cancer worldwide associated with a poor prognosis. Identifying novel drivers of growth and metastasis hold therapeutic potential for the disease. Transport homeostasis between the endoplasmic reticulum and Golgi and the secretion of matrix metalloproteinases (MMPs) mediated by Golgi have been reported to be closely associated with tumor progression. However, to date, mechanistic studies remain limited.

Results

Here, we identified KDELR2 as a potential risk factor with prognostic value in patients with BCa, especially those harbouring the KDELR2 amplification. In addition, we found that KDELR2 is a regulator of BCa cell proliferation and tumorigenicity based on bioinformatic analysis with functional studies. Mechanistically, we revealed that KDELR2 could regulate the expression of KIF20A, thus stimulating the expression of MMP2, MMP9 and MKI67. Functionally, the overexpression of KDELR2 and KIF20A markedly promoted proliferation, migration, and invasion in vitro and enhanced tumor growth in vivo, while knockdown of KDELR2 and KIF20A exerted the opposite effects. And the overexpression of KDELR2 also enhanced lymph node metastasis in vivo.

Conclusions

Collectively, our findings clarified a hitherto unexplored mechanism of KDELR2-KIF20A axis in increasing Golgi-mediated secretion of MMPs to drive tumor progression in BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00174-y.

USP2 promotes experimental colitis and bacterial infections by inhibiting the proliferation of myeloid cells and remodeling the extracellular matrix network

Inflammatory bowel disease (IBD) is closely associated with dysregulation of genetic factors and microbial environment. Here, we report a susceptible role of ubiquitin-specific protease 2 (USP2) in experimental colitis and bacterial infections. USP2 is upregulated in the inflamed mucosa of IBD patients and in the colon of mice treated with dextran sulfate sodium salt (DSS). Knockout or pharmacologic inhibition of USP2 promotes the proliferation of myeloid cells to activate IL-22 and IFNγ production of T cells. In addition, knockout of USP2 in myeloid cells inhibits the production of pro-inflammatory cytokines to relieve the dysregulation of extracellular matrix (ECM) network and promote the gut epithelial integrity after DSS treatment. Consistently, Lyz2-Cre;Usp2fl/fl mice exhibit hyper-resistance to DSS-induced colitis and Citrobacter rodentium infections compared to Usp2fl/fl mice. These findings highlight an indispensable role of USP2 in myeloid cells to modulate T cell activation and epithelial ECM network and repair, indicating USP2 as a potential target for therapeutic intervention of IBD and bacterial infections in the gastrointestinal system.

Ubiquitin-specific peptidase 2 inhibits epithelial-mesenchymal transition in clear cell renal cell carcinoma metastasis by downregulating the NF-κB pathway

Clear cell renal cell carcinoma, the most common type of renal cancer, is associated with poor survival. Ubiquitin-specific peptidase 2 regulates the molecular mechanisms of cancer cells. However, its mechanism in clear cell renal cell carcinoma remains unclear. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry were performed to assess ubiquitin-specific peptidase 2 expression in human clear cell renal cell carcinoma samples. Ubiquitin-specific peptidase 2 was weakly expressed in clear cell renal cell carcinoma samples and associated with poor patient outcomes. Ubiquitin-specific peptidase 2 inhibition promoted clear cell renal cell carcinoma cell proliferation, migration, and invasion. Ubiquitin-specific peptidase 2 overexpression inhibited clear cell renal cell carcinoma cell proliferation, migration, and invasion in vitro and in vivo. RNA-sequencing showed significant changes in the epithelial-mesenchymal transition-related pathways following ubiquitin-specific peptidase 2 knockdown. Western blotting was performed to detect the protein expression levels. Expression of p-nuclear factor-κB p65, N-cadherin, Vimentin, and Snail, which were markedly increased, as well as E-cadherin, which was decreased following ubiquitin-specific peptidase 2 knockdown. Rescue experiments using the nuclear factor-κB inhibitor BAY 11–7082 revealed that the migration and invasion abilities and the expression of epithelial-mesenchymal transition pathway proteins were inhibited in both the short hairpin RNA (shRNA) for ubiquitin-specific peptidase 2 and shRNA for negative control groups. Ubiquitin-specific peptidase 2 is a potential biomarker to distinguish clear cell renal cell carcinoma patients from healthy individuals. Ubiquitin-specific peptidase 2-mediated inhibition of epithelial-mesenchymal transition in clear cell renal cell carcinoma cells is dependent on the nuclear factor-κB pathway.

Construction of an immune-related prognostic model by exploring the tumor microenvironment of clear cell renal cell carcinoma

OBJECTIVE

In this study, bioinformatics methods were performed to screen the candidate prognosis-related genes of clear cell renal cell carcinoma (ccRCC) by analyzing the tumor microenvironment (TME).

METHODS

Gene expression and clinical data of ccRCC patients were accessed from TCGA, and R package ESTIMATE was applied to calculate immune, stromal, and ESTIMATE scores of the patients. Survival analysis was conducted per median of these three scores. Based on the scoring results, differentially expressed genes (DEGs) were screened. Regression algorithms were utilized to screen prognostic genes and establish a risk model. Finally, pathway activity differences were analyzed through GSEA.

RESULTS

Patients with the unfavorable prognosis had high immune scores. 619 DEGs (499 up-regulated and 120 down-regulated) were screened based on the differences in gene expression of the patients with high and low immune scores. These genes mainly participated in immune-related signaling pathways. A prognostic risk model for ccRCC patients was constructed and 7 immune-related signature genes (RORB, TNFSF14, UCN2, USP2, TOX3, KLRC2, SLAMF9) were obtained through regression analysis. The constructed prognostic risk model could be used for determining prognoses of patients with ccRCC.

CONCLUSION

We unraveled the association between TME and prognosis of ccRCC patients and established a prognostic risk model based on the differentially expressed genes. These results contributed to understanding of TME that affected patients' prognosis and progression of ccRCC and conduced to finding potential biomarkers of ccRCC.

M2-Polarization-related CNTNAP1 gene might be a novel immunotherapeutic target and biomarker for clear cell renal cell carcinoma

Clear cell renal carcinoma (ccRCC) is one of the most common malignancies, characterized by high mortality rate in urology. Unfortunately, reliable biomarkers for ccRCC diagnosis and prognosis remain lacking. Contactin Associated Protein 1 (CNTNAP1) has yet to be thoroughly investigated in cancer, especially its relationship with immune infiltration or clinical outcomes of ccRCC. Here, we explored the Cancer Genome Atlas Kidney Clear Cell Carcinoma database (TCGA-KIRC) for prognostic significance, differential expression, and probable mechanism of CNTNAP1. The aberrant CNTNAP1 expression was also validated by international Cancer Genome Consortium (ICGC) and ccRCC clinic samples. We used Database for Annotation, Visualization, and Integrated Discovery (DAVID) to performed the GO & KEGG enrichment. TIMER database was further utilized to assess its correlation with immune infiltration in ccRCC. The the CellMiner database was used to analyse the relationship between CNTNAP1 expression and drug sensitivity. Results showed CNTNAP1 was upregulated in TCGA-KIRC, ICGC and clinic samples. And CNTNAP1 expression was positively related to infiltration levels of cancer-associated fibroblast, regulatory T cells, and Myeloid-derived suppressor cells, while negatively related to eosinophils. Furthermore, we observed CNTNAP1 was appreciably positively associated with alternatively activated macrophage (M2) in ccRCC. Finally, high CNTNAP1 expression was negatively correlated with Nilotinib, Crizotinib, Eribulin mesylate, and Vinorelbine. Collectively, these results strongly suggest that CNTNAP1 might act as an immunotherapeutic target and a promising novel biomarker for ccRCC.

Dysregulation and activities of ubiquitin specific peptidase 2b in the pathogenesis of hepatocellular carcinoma

Ubiquitin specific peptidase-2 (USP2) plays important roles in a myriad of cellular activities through deubiquitinating target proteins and its implications in various diseases, especially cancers, are starting to emerge. Our current understanding on USP2 expression in subjects with hepatocellular carcinoma (HCC) and its roles in the pathogenesis of HCC is limited. In this study, we found that USP2 protein and mRNA levels were significantly dysregulated in HCC tumor (HCC-T) when compared to adjacent non-tumor (HCC-NT) or normal liver tissues from both human and mouse HCC model. Among the USP2 isoforms, USP2b was the predominant isoform in the normal liver and markedly down-regulated in HCC-T tissues in both human and mice. Data from overexpression, chemical inhibition and knockout studies consistently demonstrated that USP2b promoted cell proliferation, colony formation and wound healing in HepG2 and Huh 7 cells. On the other hand, USP2b exhibited proapoptotic and pronecrtotic activities through enhancing bile acid-induced apoptosis and necrosis in both HepG2 and Huh 7 cells. Unbiased proteomic analysis of USP2-knockout (KO) and parental HepG2 cells resulted in identification of USP2-regulated downstream target proteins involved in cell proliferation, apoptosis, and tumorigenesis, including serine/threonine kinase 4 (STK4), epidermal growth factor receptor (EGFR), dipeptidyl peptidase 4 (DPP4) and fatty acid binding protein 1 (FABP1). In conclusion, USP2b expression was dysregulated in subjects with HCC and contributed to the pathogenesis of HCC by promoting cell proliferation and exerting proapoptotic and pronecrotic activities. The findings provide the molecular basis for developing therapies for HCC through modulating USP2b expression or activities.

Solute carrier family 16 member 5 downregulation and its methylation might serve as a prognostic indicator of prostate cancer

Prostate cancer (PCa), characterized by high invasion, metastasis, and recurrence, is the most prevalent malignant tumor in men worldwide. A clear understanding of the underlying molecular mechanisms and their role during PCa tumorigenesis can help develop prognostic and targeted therapies. We analyzed datasets from public databases, including the Cancer Genome Atlas (TCGA) and Oncomine and Gene Expression Profiling Interactive Analysis for differential expression of solute carrier family 16 member 5 (SLC16A5). We further investigated its relationship with clinical stage, pathological grade, and prognosis of PCa. The promoter methylation level of SLC16A5 in PCa was also investigated by UALCAN. We also utilized datasets from UCSC Xena to explore the prognostic role of SLC16A5 methylation levels and CpG site. Correlations between SLC16A5 and immune infiltration were discovered through TIMER. We observed significantly lower levels of SLC16A5 mRNA in PCa relative to normal tissues across six datasets from Oncomine database (p < .001) and 498 cases from TCGA database (p < .0001). SLC16A5 is strongly negatively regulated by its DNA methylation, with a Spearman of -0.81 and Pearson of -0.80 (p < .001). The aberrant SLC16A5 expression resulted in a significant relationship with clinical stage, pathological grade, and lower SLC16A5 mRNA expression, and its hypermethylation was related to a poorer PCa prognosis. SLC16A5 acted as an important factor for PCa diagnosis, with an AUC of 0.9038 (95% CI: 0.8597-0.9479; p < .0001). Besides, the aberrant SLC16A5 expression revealed close correlations with multiple immune cells. Overall, these results indicate that decreased SLC16A5 expression might be a potential biomarker for determining prognosis and immune infiltration in PCa. The positive SLC16A5 modulation might be a promising therapeutic target for PCa.

Development of an Individualized Ubiquitin Prognostic Signature for Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common tumor type in genitourinary system and has a poor prognosis. Ubiquitin dependent modification systems have been reported in a variety of malignancies and have influenced tumor genesis and progression. However, the molecular characteristics and prognostic value of ubiquitin in ccRCC have not been systematically reported. In our study, 204 differentially expressed ubiquitin related genes (URGs) were identified from The Cancer Genome Atlas (TCGA) cohort, including 141 up-regulated and 63 down-regulated URGs. A total of seven prognostic related URGs (CDCA3, CHFR, CORO6, RNF175, TRIM72, VAV3, and WDR72) were identified by Cox regression analysis of differential URGs and used to construct a prognostic signature. Kaplan-Meier analysis confirmed that high-risk patients had a worse prognosis (P = 1.11e-16), and the predicted area under the receiver operating characteristic (ROC) curves were 0.735 at 1 year, 0.702 at 3 years, and 0.744 at 5 years, showing good prediction accuracy. Stratified analysis showed that the URGs-based prognostic signature could be used to evaluate tumor progression in ccRCC. Further analysis confirmed that the signature is an independent prognostic factor related to the prognosis of ccRCC patients, which may help to reveal the molecular mechanism of ccRCC and provide potential diagnostic and prognostic markers for ccRCC.

Prognostic Role of the Ubiquitin Proteasome System in Clear Cell Renal Cell Carcinoma: A Bioinformatic Perspective

Background: Clear cell renal cell carcinoma (ccRCC) is a common malignant tumor of the urinary system. The ubiquitin proteasome system (UPS) plays an important role in the generation, metabolism and survival of tumor. We are aimed to make a comprehensive exploration of the UPS's role in ccRCC with bioinformatic tools, which may contribute to the understanding of UPS in ccRCC, and give insight for further research. Methods: The UPS-related genes (UPSs) were collected by an integrative approach. The expression and clinical data were downloaded from TCGA database. R soft was used to perform the differentially expressed UPSs analysis, functional enrichment analysis. We also estimated prognostic value of each UPS with the help of GEPIA database. Two predicting models were constructed with the differentially expressed UPSs and prognosis-related genes, respectively. The correlations of risk score with clinical characteristics were also evaluated. Data of GSE29609 cohort were obtained from GEO database to validate the prognostic models. Results: We finally identified 91 differentially expressed UPSs, 48 prognosis related genes among them, and constructed a prognostic model with 18 UPSs successfully, the AUC was 0.760. With the help of GEPIA, we found 391 prognosis-related UPSs, accounting for 57.84% of all UPSs. Another prognostic model was constructed with 28 prognosis-related genes of them, and with a better AUC of 0.825. Additionally, our models can also stratify patients into high and low risk groups accurately in GSE29609 cohort. Similar prognostic values of our models were observed in the validated GSE29609 cohort. Conclusions: UPS is dysregulated in ccRCC. UPS related genes have significant prognostic value in ccRCC. Models constructed with UPSs are effective and applicable. An abnormal ubiquitin proteasome system should play an important role in ccRCC and be worthy of further study.

Biomarkers for Renal Cell Carcinoma Recurrence: State of the Art

PURPOSE OF REVIEW

We aim to summarize the current state of art about the possible use of biomarkers for predicting renal cell carcinoma (RCC) recurrence after curative treatment. In addition, we aim to provide a snapshot about the clinical implication of biomarkers use for follow-up planification.

RECENT FINDINGS

A wide variety of biomarkers have been proposed. RCC biomarkers have been individuated in tumoral tissue, blood, and urine. A variety of molecules, including proteins, DNA, and RNA, warrant a good accuracy for RCC recurrence and progression prediction. Their use in prediction models might warrant a better patients' risk stratification. Future prognostic models will probably include a combination of classical features (tumor grade, stage, etc.) and novel biomarkers. Such models might allow a more accurate treatment and follow-up planification.

USP2-Related Cellular Signaling and Consequent Pathophysiological Outcomes

Ubiquitin specific protease (USP) 2 is a multifunctional deubiquitinating enzyme. USP2 modulates cell cycle progression, and therefore carcinogenesis, via the deubiquitination of cyclins and Aurora-A. Other tumorigenic molecules, including epidermal growth factor and fatty acid synthase, are also targets for USP2. USP2 additionally prevents p53 signaling. On the other hand, USP2 functions as a key component of the CLOCK/BMAL1 complex and participates in rhythmic gene expression in the suprachiasmatic nucleus and liver. USP2 variants influence energy metabolism by controlling hepatic gluconeogenesis, hepatic cholesterol uptake, adipose tissue inflammation, and subsequent systemic insulin sensitivity. USP2 also has the potential to promote surface expression of ion channels in renal and intestinal epithelial cells. In addition to modifying the production of cytokines in immune cells, USP2 also modulates the signaling molecules that are involved in cytokine signaling in the target cells. Usp2 knockout mice exhibit changes in locomotion and male fertility, which suggest roles for USP2 in the central nervous system and male genital tract, respectively. In this review, we summarize the cellular events with USP2 contributions and list the signaling molecules that are upstream or downstream of USP2. Additionally, we describe phenotypic differences found in the in vitro and in vivo experimental models.

CircHIPK3 promotes proliferation and metastasis and inhibits apoptosis of renal cancer cells by inhibiting MiR-485-3p

BACKGROUND

The intervention of circHIPK3 in renal carcinoma (RC) has not been reported, and thus, the current study investigated the intervention and mechanism of circHIPK3 in RC.

METHODS

The expression of circHIPK3 in RC tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Ribonuclease R (RNase R) resistance and distribution of circHIPK3 and HIPK3 were analyzed by RNase R digestion experiments and cytoplasm/nucleus separation experiments. CircHIPK3 was knocked down in ACHN and 769-P cells. Cell counting kit-8 (CCK-8), colony formation assay, scratch assay, and Transwell assay were performed to detect cell proliferation and metastasis. CircInteractome, qRT-PCR and dual-luciferase reporter assay were used to predict the target miRNAs of circHIPK3. Furthermore, a series of rescue experiments were performed to analyze the regulatory relationship between circHIPK3 and miR-485-3p. Epithelial-mesenchymal transition (EMT) and the expressions of apoptosis-associated markers were detected by Western blot and qRT-PCR. The regulatory relationship between circHIPK3 and miR-485-3p in vivo was explored by xenograft experiments, Western blot, qRT-PCR and immunohistochemistry (Ki-67).

RESULTS

CircHIPK3 was mainly overexpressed in the cytoplasm of RC tissues and cells. Knocking down circHIPK3 inhibited the proliferation, migration, and invasion of RC cells. The expression of circHIPK3 was negatively related to that of its target gene miR-485-3p. Results of the rescue experiments showed that circHIPK3 overexpression could partially reverse the anti-carcinoma effect of miR-485-3p mimic. The specific mechanism of circHIPK3 was related to the effect of miR-485-3p on partially reversing the up-regulated expressions of Clever caspase-3, Bax, E-Cadherin and down-regulated expressions of Bcl-2, N-Cadherin and Vimentin. The results of in vivo experiments demonstrated that circHIPK3 promoted tumor growth and the expression of Ki-67 by down-regulating miR-485-3p.

CONCLUSION

CircHIPK3 promotes the proliferation and metastasis and inhibits the apoptosis of RC cells through competitively binding to miR-485-3p.