UCH-L1 promotes invasion of breast cancer cells through activating Akt signaling pathway

Inhibition of UCH-L1 enhances immunotherapy efficacy in triple-negative breast cancer by stabilizing PD-L1

Recent research indicates that programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors show promise in treating triple-negative breast cancer (TNBC), but their efficacy is lower than anticipated, especially when used alone. Therefore, enhancing the anti-tumor immune response strategy for TNBC is crucial. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), involved in tumor cell regulation and a potential therapeutic target, has an undefined role in TNBC immunotherapy. In this study, we explored the inverse correlation between UCH-L1 and PD-L1 in TNBC patient tissues. Through in vitro experiments, we found that UCH-L1 negatively regulates PD-L1 by stabilizing the E3 ubiquitin ligase ariadne-1 homolog (ARIH1), which promotes PD-L1 ubiquitination and degradation. Further analysis in Balb/c mice xenograft tumors showed that UCH-L1 correlates with GZMB+/CD8+ T cell infiltration in TNBC, suggesting potential synergistic effects when combining UCH-L1 inhibitors with PD-L1 antibodies. Overall, in TNBC, UCH-L1 stabilizes ARIH1, leading to low PD-L1 expression, which may explain the limited effectiveness of immunotherapy in TNBC patients. Our mouse experiments showed improved therapeutic effects when combining UCH-L1 inhibitors with PD-L1 antibodies. These findings offer a new avenue for immunotherapy in TNBC patients.

Dopamine Toxicity Induces ROS-Dependent Death of Murine Neuroblastoma Cells: Impact on the Interactions of Cofilin With UCHL1 and MMP9

The death of dopaminergic neurons, a hallmark event during Parkinson's disease (PD), leads to increased dopamine concentration in the neuronal micro-environment. Keeping this in mind, we intend to understand the impact of elevated dopamine concentration on molecular interactions among proteins and the stability of the neuronal cytoskeleton. We used differentiated N2A cells and exposed them to 100 µM DA for 24 h. Evaluations of cell death, measurement of the concentration of DA oxidation products and reactive oxygen species (ROS), conventional RT-PCR, western blotting, zymography, reverse zymography, co-immunoprecipitation, mitochondrial transmembrane potential, confocal imaging, and in-silico studies were performed thereon. We observed that a significant number of viable N2A cells underwent ROS-dependent apoptotic cell death under elevated media DA concentrations. An altered transcriptional pattern of alpha-synuclein, UCHL1, and cofilin genes and their respective gene products were also observed. The activity and expression of matrix metalloproteinases9 (MMP9), involved in neuro-inflammation, was enhanced upon DA-exposure. Further, DA exposure also led to degradation of actin cytoskeleton. In silico studies revealed that interactions of Cofilin with UCHL1 and MMP9 were altered in dopamine-rich microenvironment. This result was further validated by co-immunoprecipitation experiments. Collectively our observations with murine neuroblastoma cells suggest that DA toxicity alters interaction patterns among intracellular proteins and degrades neuronal cytoskeleton that finally leads to cell death. Our study unveils a new frontier in PD treatment by paving the way for the development of specific drugs targeting the DA altered protein interactions.

Secretome and Proteome of Extracellular Vesicles Provide Protein Markers of Lung and Colorectal Cancer

Colorectal cancer (CRC) and lung cancer (LC) are leading causes of cancer-related mortality, highlighting the need for minimally invasive diagnostic, prognostic, and predictive markers for these cancers. Proteins secreted by a tumor into the extracellular space directly, known as the tumor secretome, as well as proteins in the extra-cellular vesicles (EVs), represent an attractive source of biomarkers for CRC and LC. We performed proteomic analyses on secretome and EV samples from LC (A549, NCI-H23, NCI-H460) and CRC (Caco2, HCT116, HT-29) cell lines and targeted mass spectrometry on EVs from plasma samples of 20 patients with CRC and 19 healthy controls. A total of 782 proteins were identified across the CRC and LC secretome and EV samples. Of these, 22 and 44 protein markers were significantly elevated in the CRC and LC samples, respectively. Functional annotation revealed enrichment in proteins linked to metastasis and tumor progression for both cancer types. In EVs isolated from the plasma of patients with CRC, ITGB3, HSPA8, TUBA4A, and TLN1 were reduced, whereas FN1, SERPINA1, and CST3 were elevated, compared to healthy controls. These findings support the development of minimally invasive liquid biopsy methods for the detection, prognosis, and treatment monitoring of LC and CRC.

PGP9.5 expression in human tumors: A tissue microarray study on 13,920 tumors from 120 different tumor entities

The protein gene product 9.5 (PGP9.5), also termed ubiquitin C-terminal hydrolase L1 (UCH-L1) is an important component of the ubiquitination/deubiquitination system and plays a role in axonal transport. To comprehensively determine PGP9.5 expression in neoplastic tissues, a tissue microarray containing 13,920 samples from 120 different tumor types and subtypes was analyzed by immunohistochemistry (IHC). PGP9.5 immunostaining was found in 109 of 120 tumor categories, 87 of which contained at least one strongly positive case. PGP9.5 positivity was most seen in neuronal and neuroendocrine neoplasms (50-100 %), germ cell neoplasms (28-84 %), sarcomas and carcinosarcomas (up to 91 %), and in mesotheliomas (58-83 %). In clear cell RCC (renal cell carcinomas), strong PGP9.5 staining was associated with high ISUP (International Society of Urological Pathology) grade (p<0.0001), advanced pT stage (p=0.0003), nodal (p=0.0242) and distant metastasis (p<0.0001) as well as with a short overall, tumor specific and recurrence free survival (p≤0.0007 each). In papillary RCC, strong PGP9.5 staining was associated with high ISUP grade (p=0.009) and reduced recurrence free survival (p=0.0221). In urothelial carcinoma of the urinary bladder, high PGP9.5 expression was associated with muscle-invasion (p<0.0001). PGP9.5 immunostaining was unrelated to histological parameters for tumor aggressiveness in 295 serous high-grade ovarian carcinomas, 174 endometrioid endometrium carcinomas, 292 papillary and 89 follicular thyroid carcinomas, 405 ductal adenocarcinomas of the pancreas and in 327 gastric adenocarcinomas. In summary, our data provide a comprehensive overview of PGP9.5 expression in cancer and demonstrate positive cases in a broad range of entities. PGP9.5 overexpression is linked to patient outcome in some tumor entities (i.e., clear cell RCC) but appears to be unrelated to clinically relevant tumor characteristics in many other frequent tumor entities.

Role of long non-coding RNAs (lncRNAs) in gastric cancer metastasis: A comprehensive review

One of the greatest frequent types of malignancy is gastric cancer (GC). Metastasis, an essential feature of stomach cancer, results in a high rate of mortality and a poor prognosis. However, metastasis biological procedures are not well recognized. Long non-coding RNAs (lncRNAs) have a role in numerous gene regulation pathways via epigenetic modification as well as transcriptional and post-transcriptional control. LncRNAs have a role in a variety of disorders, such as cardiovascular disease, Alzheimer's, and cancer. LncRNAs are substantially related to GC incidence, progression, metastasis and drug resistance. Several research released information on the molecular processes of lncRNAs in GC pathogenesis. By interacting with a gene's promoter or enhancer region to influence gene expression, lncRNAs can operate as an oncogene or a tumor suppressor. This review includes the lncRNAs associated with metastasis of GC, which may give insights into the processes as well as potential clues for GC predicting and tracking.

Inhibition of Ubiquitin C-Terminal Hydrolase L1 Facilitates Cutaneous Wound Healing via Activating TGF-β/Smad Signalling Pathway in Fibroblasts

Ubiquitin C-terminal hydrolase L1 (UCHL1) plays vital roles in cell proliferation, angiogenesis, inflammation and oxidative stress. Nevertheless, it is unclear whether UCHL1 could regulate the biologic behaviour of cells and ultimately influences wound healing. We aim to illustrate the roles and the underlying mechanism of UCHL1 in cutaneous wound healing. Murine full-thickness excisional wound model was utilised to study the effects of UCHL1 on wound healing through topical administration of the UCHL1 inhibitor LDN57444, followed by assessment of wound areas and histological alterations. Subsequently, ethynyldeoxyuridine, scratch and transwell assays were performed to examine fibroblast migration and proliferation. The extracellular matrix (ECM)-related genes expression and transforming growth factor-β (TGF-β)/Smad signalling pathways activation were investigated by immuno-fluorescent staining, Western blots and quantitative reverse transcription polymerase chain reaction. We identified elevated UCHL1 expression in non-healing wound tissues. The UCHL1 expression displayed a dynamic change and reached a peak on Day-7 post-wounding during the healing process in mice. Cutaneous administration of LDN57444 promoted wound healing by facilitating collagen deposition, myofibroblast activation and angiogenesis. In vitro experiments demonstrated that UCHL1 concentration dependently inhibited migration, ECM synthesis and activation of human dermal fibroblasts, which was mechanistically related to downregulation of TGF-β/Smad signalling. Furthermore, these effects could be reversed by TGF-β inhibitor SB431542. Our findings reveal that UCHL1 is a negative regulator of cutaneous wound healing and considered as a novel prospective therapeutic target for effective wound healing.

UCHL1 Overexpression Is Related to the Aggressive Phenotype of Non-small Cell Lung Cancer

BACKGROUND

Ubiquitin C-terminal hydrolase L1 (UCHL1), which encodes thiol protease that hydrolyzes a peptide bond at the C-terminal glycine residue of ubiquitin, regulates cell differentiation, proliferation, transcriptional regulation, and numerous other biological processes and may be involved in lung cancer progression. UCHL1 is mainly expressed in the brain and plays a tumor-promoting role in a few cancer types; however, there are limited reports regarding its role in lung cancer.

METHODS

Single-cell RNA (scRNA) sequencing using 10X chromium v3 was performed on a paired normal-appearing and tumor tissue from surgical specimens of a patient who showed unusually rapid progression. To validate clinical implication of the identified biomarkers, immunohistochemical (IHC) analysis was performed on 48 non-small cell lung cancer (NSCLC) tissue specimens, and the correlation with clinical parameters was evaluated.

RESULTS

We identified 500 genes overexpressed in tumor tissue compared to those in normal tissue. Among them, UCHL1, brain expressed X-linked 3 (BEX3), and midkine (MDK), which are associated with tumor growth and progression, exhibited a 1.5-fold increase in expression compared to that in normal tissue. IHC analysis of NSCLC tissues showed that only UCHL1 was specifically overexpressed. Additionally, in 48 NSCLC specimens, UCHL1 was specifically upregulated in the cytoplasm and nuclear membrane of tumor cells. Multivariable logistic analysis identified several factors, including smoking, tumor size, and high-grade dysplasia, to be typically associated with UCHL1 overexpression. Survival analyses using The Cancer Genome Atlas (TCGA) datasets revealed that UCHL1 overexpression is substantially associated with poor survival outcomes. Furthermore, a strong association was observed between UCHL1 expression and the clinicopathological features of patients with NSCLC.

CONCLUSION

UCHL1 overexpression was associated with smoking, tumor size, and high-grade dysplasia, which are typically associated with a poor prognosis and survival outcome. These findings suggest that UCHL1 may serve as an effective biomarker of NSCLC.

Targeting the MHC-I endosomal-lysosomal trafficking pathway in cancer: From mechanism to immunotherapy

Immune checkpoint blockade (ICB) therapy has achieved broad applicability and durable clinical responses across cancer types. However, the overall response rate remains suboptimal because some patients do not respond or develop drug resistance. The low infiltration of CD8+ cytotoxic T cells (CTLs) in the tumor microenvironment due to insufficient antigen presentation is closely related to the innate resistance to ICB. The duration and spatial distribution of major histocompatibility complex class I (MHC-I) expression on the cell surface is critical for the efficient presentation of endogenous tumor antigens and subsequent recognition and clearance by CTLs. Tumor cells reduce the surface expression of MHC-I via multiple mechanisms to impair antigen presentation pathways and evade immunity and/or develop resistance to ICB therapy. As an increasing number of studies have focused on membrane MHC-I trafficking and degradation in tumor cells, which may impact the effectiveness of tumor immunotherapy. It is necessary to summarize the mechanism regulating membrane MHC-I translocation into the cytoplasm and degradation via the lysosome. We reviewed recent advances in the understanding of endosomal-lysosomal MHC-I transport and highlighted the means exploited by tumor cells to evade detection and clearance by CTLs. We also summarized new therapeutic strategies targeting these pathways to enhance classical ICB treatment and provide new avenues for optimizing cancer immunotherapy.

UCHL3 promotes hepatocellular carcinoma progression by stabilizing EEF1A1 through deubiquitination

BACKGROUND

Hepatocellular carcinoma (HCC) ranks as the second leading cause of global cancer-related deaths and is characterized by a poor prognosis. Eukaryotic translation elongation factor 1 alpha 1 (EEF1A1) have been proved to play important roles in various human cancers, whereas the deubiquitination of EEF1A1 was poorly understood.

METHODS

The binding and regulatory relationship between Ubiquitin carboxyl-terminal hydrolase L3 (UCHL3) and EEF1A1 was validated using clinical tissue samples, reverse transcription quantitative real-time fluorescence quantitative PCR (RT-qPCR), Western blotting, co-immunoprecipitation, and immunofluorescence, as well as ubiquitin detection and cyclohexamide tracking experiments. Finally, the impact of the UCHL3/EEF1A1 axis on HCC malignant behavior was analyzed through functional experiments and nude mouse models.

RESULTS

UCHL3 was found to have a high expression level in HCC tissues. Tissue samples from 60 HCC patients were used to evaluate the correlation between UCHL3 and EEF1A1. UCHL3 binds to EEF1A1 through the lysine site, which reduces the ubiquitination level of EEF1A1. Functional experiments and nude mouse models have demonstrated that the UCHL3/EEF1A1 axis promotes the migration, stemness, and drug resistance of HCC cells. Reducing the expression of EEF1A1 can reverse the effect of UCHL3 on the malignant behavior of HCC cells.

CONCLUSION

Our findings revealed that UCHL3 binds and stabilizes EEF1A1 through deubiquitination. UCHL3 and EEF1A1 formed a functional axis in facilitating the malignant progression of HCC, proving new insights for the anti-tumor targeted therapy for HCC.

The Suppression of Ubiquitin C-Terminal Hydrolase L1 Promotes the Transdifferentiation of Auditory Supporting Cells into Hair Cells by Regulating the mTOR Pathway

In mammals, hearing loss is irreversible due to the lack of the regenerative capacity of the auditory epithelium. However, stem/progenitor cells in mammalian cochleae may be a therapeutic target for hearing regeneration. The ubiquitin proteasome system plays an important role in cochlear development and maintenance. In this study, we investigated the role of ubiquitin C-terminal hydrolase L1 (UCHL1) in the process of the transdifferentiation of auditory supporting cells (SCs) into hair cells (HCs). The expression of UCHL1 gradually decreased as HCs developed and was restricted to inner pillar cells and third-row Deiters' cells between P2 and P7, suggesting that UCHL1-expressing cells are similar to the cells with Lgr5-positive progenitors. UCHL1 expression was decreased even under conditions in which supernumerary HCs were generated with a γ-secretase inhibitor and Wnt agonist. Moreover, the inhibition of UCHL1 by LDN-57444 led to an increase in HC numbers. Mechanistically, LDN-57444 increased mTOR complex 1 activity and allowed SCs to transdifferentiate into HCs. The suppression of UCHL1 induces the transdifferentiation of auditory SCs and progenitors into HCs by regulating the mTOR pathway.

Dysregulation of deubiquitination in breast cancer

Breast cancer (BC) is a highly frequent malignant tumor that poses a serious threat to women's health and has different molecular subtypes, histological subtypes, and biological features, which act by activating oncogenic factors and suppressing cancer inhibitors. The ubiquitin-proteasome system (UPS) is the main process contributing to protein degradation, and deubiquitinases (DUBs) are reverse enzymes that counteract this process. There is growing evidence that dysregulation of DUBs is involved in the occurrence of BC. Herein, we review recent research findings in BC-associated DUBs, describe their nature, classification, and functions, and discuss the potential mechanisms of DUB-related dysregulation in BC. Furthermore, we present the successful treatment of malignant cancer with DUB inhibitors, as well as analyzing the status of targeting aberrant DUBs in BC.

Protein Stability Regulation in Osteosarcoma: The Ubiquitin-like Modifications and Glycosylation as Mediators of Tumor Growth and as Targets for Therapy

The identification of new therapeutic targets and the development of innovative therapeutic approaches are the most important challenges for osteosarcoma treatment. In fact, despite being relatively rare, recurrence and metastatic potential, particularly to the lungs, make osteosarcoma a deadly form of cancer. In fact, although current treatments, including surgery and chemotherapy, have improved survival rates, the disease's recurrence and metastasis are still unresolved complications. Insights for analyzing the still unclear molecular mechanisms of osteosarcoma development, and for finding new therapeutic targets, may arise from the study of post-translational protein modifications. Indeed, they can influence and alter protein structure, stability and function, and cellular interactions. Among all the post-translational modifications, ubiquitin-like modifications (ubiquitination, deubiquitination, SUMOylation, and NEDDylation), as well as glycosylation, are the most important for regulating protein stability, which is frequently altered in cancers including osteosarcoma. This review summarizes the relevance of ubiquitin-like modifications and glycosylation in osteosarcoma progression, providing an overview of protein stability regulation, as well as highlighting the molecular mediators of these processes in the context of osteosarcoma and their possible targeting for much-needed novel therapy.

Modulation of the ubiquitin-proteasome system by phytochemicals: Therapeutic implications in malignancies with an emphasis on brain tumors

Regarding the multimechanistic nature of cancers, current chemo- or radiotherapies often fail to eradicate disease pathology, and frequent relapses or resistance to therapies occur. Brain malignancies, particularly glioblastomas, are difficult-to-treat cancers due to their highly malignant and multidimensional biology. Unfortunately, patients suffering from malignant tumors often experience poor prognoses and short survival periods. Thus far, significant efforts have been conducted to discover novel and more effective modalities. To that end, modulation of the ubiquitin-proteasome system (UPS) has attracted tremendous interest since it affects the homeostasis of proteins critically engaged in various cell functions, for example, cell metabolism, survival, proliferation, and differentiation. With their safe and multimodal actions, phytochemicals are among the promising therapeutic tools capable of turning the operation of various UPS elements. The present review, along with an updated outline of the role of UPS dysregulation in multiple cancers, provided a detailed discussion on the impact of phytochemicals on the UPS function in malignancies, especially brain tumors.

Parathyroid Carcinoma: Update on Pathogenesis and Therapy

Parathyroid carcinoma (PC) is a very rare endocrine cancer with aggressive behavior, a high metastatic potential, and a poor prognosis. Surgical resection of affected gland(s) and other involved structures is the elective therapy. Pre-operative and intra-operative differential diagnosis with benign parathyroid adenoma remains a challenge. The lack of a clear pre-operative diagnosis does not allow one, in many cases, to choose the correct surgical approach to malignant PC, increasing persistence, the recurrence rate, and the risk of metastases. An initial wrong diagnosis of parathyroid adenoma, with a minimally invasive parathyroidectomy, is associated with over 50% occurrence of metastases after surgery. Genetic testing could help in identifying patients at risk of congenital PC (i.e., CDC73 gene) and in driving the choice of neck surgery extension. Targeted effective treatments, other than surgery, for advanced and metastatic PC are needed. The pathogenesis of malignant parathyroid carcinogenesis is still largely unknown. In the last few years, advanced molecular techniques allowed researchers to identify various genetic abnormalities and epigenetic features characterizing PC, which could be crucial for selecting molecular targets and developing novel targeted therapeutic agents. We reviewed current findings in PC genetics, epigenetics, and proteomics and state-of-the-art therapies.

Ubiquitin C‑terminal hydrolase‑L1: A new cancer marker and therapeutic target with dual effects (Review)

Ubiquitin C-terminal hydrolase-L1 (UCH-L1), a member of the lesser-known deubiquitinating enzyme family, has deubiquitinase and ubiquitin (Ub) ligase activity and the role of stabilizing Ub. UCH-L1 was first discovered in the brain and is associated with regulating cell differentiation, proliferation, transcriptional regulation and numerous other biological processes. UCH-L1 is predominantly expressed in the brain and serves a role in tumor promotion or inhibition. There is still controversy about the effect of UCH-L1 dysregulation in cancer and its mechanisms are unknown. Extensive research to investigate the mechanism of UCH-L1 in different types of cancer is key for the future treatment of UCH-L1-associated cancer. The present review details the molecular structure and function of UCH-L1. The role of UCH-L1 in different types of cancer is also summarized and how novel treatment targets provide a theoretical foundation in cancer research is discussed.

Precision Targeting of Endogenous Epidermal Growth Factor Receptor (EGFR) by Structurally Aligned Dual-Modifier Labeling

Covalent modification of endogenous proteins by chemical probes is used for proteome-wide profiling of cellular protein function and drug discovery. However, probe selectivity in the complex cellular environment is a challenge, and new probes with better target selectivity are continuously needed. On the basis of the success of monocovalent activity-based and reactivity-based probes, an approach of structurally aligned dual-modifier labeling (SADL) was investigated here on its potential in improving target precision. Two reactive groups, based on the acrylamide and NHS ester chemistry, were linked with structural alignment to be under the same anilinoquinazoline ligand-directive for targeting the epidermal growth factor receptor (EGFR) protein kinase as the model system for proteome-wide profiling. The SADL approach was compared with its monocovalent precursors in a label-free MaxLFQ workflow using MDA-MB-468 triple negative breast cancer cells. The dual-modifier probe consistently showed labeling of EGFR with improved precision over both monocovalent precursors under various controls. The workflow also labeled endogenous USP34 and PKMYT1 with high selectivity. Precision labeling with two covalent modifiers under a common ligand directive may broaden protein identification opportunities in the native environment to complement genetic and antibody-based approaches for elucidating biological or disease mechanisms, as well as accelerating drug target discovery.

UCHL1 promotes proliferation and metastasis in head and neck squamous cell carcinoma and could be a potential therapeutic target

OBJECTIVE

The purpose of this study was to research the physiological roles of ubiquitin carboxyl-terminal esterase L1 (UCHL1) in head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Ten HNSCC samples and matched normal oral mucosal tissues were collected. UCHL1 expression of these tissues was detected by the immunohistochemical staining and real-time quantitative polymerase chain reaction. The human HNSCC cell line HN6 UCHL1 knockout (UCHL1 KO) cell line was constructed using CRISPR/CAS9 gene editing and verified by western blotting. Wound healing assay, cell proliferation assay, cell invasion assay, and flow cytometric analysis of the cell cycle and apoptosis were applied to research the role of UCHL1 in HNSCC. Also, an RNAseq gene expression data set and HNSCC patient survival data from The Cancer Genome Atlas were analyzed.

RESULTS

UCHL1 was highly expressed in HNSCC tissues compared with normal oral mucosal tissues (P = .032). A decreased proliferation (P < .0001), migration (P < .0001), and invasion (P = .0049) ability of HN6 cells was exhibited after knockout of UCHL1. However, HN6 UCHL1 KO cells showed no significant differences in the cell cycle or apoptosis. The progression, nodal metastasis status, and stage of HNSCC had a positive correlation with the expression of UCHL1.

CONCLUSIONS

UCHL1 plays an important role in HNSCC, and we consider that targeting UCHL1 may be a feasible therapeutic strategy for HNSCC.

Distinct Gene Expression Profiles of Matched Primary and Metastatic Triple-Negative Breast Cancers

Background: Although triple-negative breast cancer (TNBC) is associated with an increased risk of recurrence and metastasis, the molecular mechanisms underlying metastasis in TNBC remain unknown. To identify transcriptional changes and genes regulating metastatic progression in TNBC, we compared the transcriptomic profiles of primary and matched metastatic tumors using massively parallel RNA sequencing. Methods: We performed gene expression profiling using formalin-fixed paraffin-embedded (FFPE) TNBC tissues of patients from two cohorts: the Zurich cohort (n = 31) and the Stavanger cohort (n = 5). Among the 31 patients in the Zurich cohort, 18 had primary TNBC tumors that did not metastasize, and 13 had primary tumors that metastasized (11 paired primary and locoregional recurrences). The Stavanger cohort included five matched primary and metastatic TNBC tumors. Significantly differentially expressed genes (DEGs; absolute fold change ≥2, p < 0.05) were identified and subjected to functional analyses. We investigated if there was any overlap between DEGs from both the cohorts with epithelial-to-mesenchymal-to-amoeboid transition (EMAT) gene signature. xCell was used to estimate relative fractions of 64 immune and stromal cell types in each RNA-seq sample. Results: In the Zurich cohort, we identified 1624 DEGs between primary TNBC tumors and matched metastatic lesions. xCell analysis revealed a significantly higher immune scores for metastatic lesions compared to paired primary tumors in the Zurich cohort. We also found significant upregulation of three MammaPrint signature genes (HRASLS, TGFB3 and RASSF7) in primary tumors that metastasized compared to primary tumors that remained metastasis-free. In the Stavanger cohort, we identified 818 DEGs between primary tumors and matched metastatic lesions. No significant differences in xCell immune scores were observed. We found that 21 and 14 DEGs from Zurich and Stavanger cohort, respectively, overlapped with the EMAT gene signature. In both cohorts, genes belonging to the MMP, FGF, and PDGFR families were upregulated in primary tumors compared to matched metastatic lesions. Conclusions: Our results suggest that distinct gene expression patterns exist between primary TNBCs and matched metastatic tumors. Further studies are warranted to explore whether these discrete expression profiles underlie or result from disease status.

UCHL1 protects against ischemic heart injury via activating HIF-1α signal pathway

Ubiquitin carboxyl-terminal esterase L1 (UCHL1) has been thought to be a neuron specific protein and shown to play critical roles in Parkinson's Disease and stroke via de-ubiquiting and stabilizing key pathological proteins, such as α-synuclein. In the present study, we found that UCHL1 was significantly increased in both mouse and human cardiomyocytes following myocardial infarction (MI). When LDN-57444, a pharmacological inhibitor of UCHL1, was used to treat mice subjected to MI surgery, we found that administration of LDN-57444 compromised cardiac function when compared with vehicle treated hearts, suggesting a potential protective role of UCHL1 in response to MI. When UCHL1 was knockout by CRISPR/Cas 9 gene editing technique in human induced pluripotent stem cells (hiPSCs), we found that cardiomyocytes derived from UCHL1−/− hiPSCs were more susceptible to hypoxia/re-oxygenation induced injury as compared to wild type cardiomyocytes. To study the potential targets of UCHL1, a BioID based proximity labeling approach followed by mass spectrum analysis was performed. The result suggested that UCHL1 could bind to and stabilize HIF-1α following MI. Indeed, expression of HIF-1α was lower in UCHL1−/− cells as determined by Western blotting and HIF-1α target genes were also suppressed in UCHL1−/− cells as quantified by real time RT-PCR. Recombinant UCHL1 (rUCHL1) protein was purified by E. Coli fermentation and intraperitoneally (I.P.) delivered to mice. We found that administration of rUCHL1 could significantly preserve cardiac function following MI as compared to control group. Finally, adeno associated virus mediated cardiac specific UCHL1 delivery (AAV9-cTNT-m-UCHL1) was performed in neonatal mice. UCHL1 overexpressing hearts were more resistant to MI injury as compare to the hearts infected with control virus. In summary, our data revealed a novel protective role of UCHL1 on MI via stabilizing HIF-1α and promoting HIF-1α signaling.

UCHL1 as a novel target in breast cancer: emerging insights from cell and chemical biology

Breast cancer has the highest incidence and death rate among cancers in women worldwide. In particular, metastatic estrogen receptor negative (ER-) breast cancer and triple-negative breast cancer (TNBC) subtypes have very limited treatment options, with low survival rates. Ubiquitin carboxyl terminal hydrolase L1 (UCHL1), a ubiquitin C-terminal hydrolase belonging to the deubiquitinase (DUB) family of enzymes, is highly expressed in these cancer types, and several key reports have revealed emerging and important roles for UCHL1 in breast cancer. However, selective and potent small-molecule UCHL1 inhibitors have been disclosed only very recently, alongside chemical biology approaches to detect regulated UHCL1 activity in cancer cells. These tools will enable novel insights into oncogenic mechanisms driven by UCHL1, and identification of substrate proteins deubiquitinated by UCHL1, with the ultimate goal of realising the potential of UCHL1 as a drug target in breast cancer.

Genetics and Epigenetics of Parathyroid Carcinoma

Parathyroid carcinoma (PC) is an extremely rare malignancy, accounting less than 1% of all parathyroid neoplasms, and an uncommon cause of primary hyperparathyroidism (PHPT), characterized by an excessive secretion of parathyroid hormone (PTH) and severe hypercalcemia. As opposed to parathyroid hyperplasia and adenomas, PC is associated with a poor prognosis, due to a commonly unmanageable hypercalcemia, which accounts for death in the majority of cases, and an overall survival rate of 78-85% and 49-70% at 5 and 10 years after diagnosis, respectively. No definitively effective therapies for PC are currently available. The mainly employed treatment for PC is the surgical removal of tumoral gland(s). Post-surgical persistent or recurrent disease manifest in about 50% of patients. The comprehension of genetic and epigenetic bases and molecular pathways that characterize parathyroid carcinogenesis is important to distinguish malignant PCs from benign adenomas, and to identify specific targets for novel therapies. Germline heterozygote inactivating mutations of the CDC73 tumor suppressor gene, with somatic loss of heterozygosity at 1q31.2 locus, account for about 50-75% of familial cases; over 75% of sporadic PCs harbor biallelic somatic inactivation/loss of CDC73. Recurrent mutations of the PRUNE2 gene, a recurrent mutation in the ADCK1 gene, genetic amplification of the CCND1 gene, alterations of the PI3K/AKT/mTOR signaling pathway, and modifications of microRNA expression profile and gene promoter methylation pattern have all been detected in PC. Here, we review the current knowledge on gene mutations and epigenetic changes that have been associated with the development of PC, in both familial and sporadic forms of this malignancy.

Akt Isoforms: A Family Affair in Breast Cancer

Simple Summary

Breast cancer is the second leading cause of cancer-related death in women in the United States. The Akt signaling pathway is deregulated in approximately 70% of patients with breast cancer. While targeting Akt is an effective therapeutic strategy for the treatment of breast cancer, there are several members in the Akt family that play distinct roles in breast cancer. However, the function of Akt isoforms depends on many factors. This review analyzes current progress on the isoform-specific functions of Akt isoforms in breast cancer.

Abstract

Akt, also known as protein kinase B (PKB), belongs to the AGC family of protein kinases. It acts downstream of the phosphatidylinositol 3-kinase (PI3K) and regulates diverse cellular processes, including cell proliferation, cell survival, metabolism, tumor growth and metastasis. The PI3K/Akt signaling pathway is frequently deregulated in breast cancer and plays an important role in the development and progression of breast cancer. There are three closely related members in the Akt family, namely Akt1(PKBα), Akt2(PKBβ) and Akt3(PKBγ). Although Akt isoforms share similar structures, they exhibit redundant, distinct as well as opposite functions. While the Akt signaling pathway is an important target for cancer therapy, an understanding of the isoform-specific function of Akt is critical to effectively target this pathway. However, our perception regarding how Akt isoforms contribute to the genesis and progression of breast cancer changes as we gain new knowledge. The purpose of this review article is to analyze current literatures on distinct functions of Akt isoforms in breast cancer.

Antiprostate Cancer Activity of Ineupatolide Isolated from Carpesium cernuum L

OBJECTIVE

The aim of the study was to investigate the antiprostate cancer effects and mechanism of ineupatolide (T-21), a natural product isolated from the Compositae plant Carpesium cernuum L., on PC-3 human prostate cancer cells.

METHODS

The effect of T-21 on the proliferation of PC-3 cells was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell migration, and invasion experiments; the morphology of cell apoptosis was observed by Hoechst-propidium iodide staining; the effects of T-21 on PC-3 cell apoptosis and the cell cycle were evaluated by flow cytometry; and the effect of T-21 on the expression levels of phosphorylated protein kinase B (p-AKT), AKT, X-linked inhibitor of apoptosis protein (xlAP), procaspase-3, and poly (ADP-ribose) polymerase (PARP) in PC-3 cells was measured by western blotting.

RESULTS

T-21 significantly inhibited the proliferation of cells, and its half-maximal inhibitory concentrations at 12, 24, and 48 h were 38.46 ± 1.01, 24.63 ± 0.70, and 7.36 ± 0.58 μM, respectively. T-21 may promote cell apoptosis in a concentration-dependent manner and block the cell cycle in the G2 and S phases. In addition, T-21 significantly reduced the protein expression levels of p-AKT, AKT, xlAP, procaspase-3, and PARP.

CONCLUSION

T-21 exhibits antiproliferation effects on PC-3 cells by promoting apoptosis and arresting the cell cycle in the G2 and S phases. The possible mechanism underlying its potential therapeutic effects against prostate cancer is related to the AKT/xlAP pathway.

UCH-L1 inhibitor LDN-57444 hampers mouse oocyte maturation by regulating oxidative stress and mitochondrial function and reducing ERK1/2 expression

Oocyte maturation is a prerequisite for successful fertilization and embryo development. Incomplete oocyte maturation can result in infertility. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) has been found to be implicated in oocyte maturation and embryo development. However, the cellular and molecular mechanisms of UCH-L1 underlying oocyte maturation have not been fully elucidated. In the present study, we observed that the introduction of UCH-L1 inhibitor LDN-57444 suppressed first polar body extrusion during mouse oocyte maturation. The inhibition of UCH-L1 by LDN-57444 led to the notable increase in reactive oxygen species (ROS) level, conspicuous reduction in glutathione (GSH) content and mitochondrial membrane potential (MMP), and blockade of spindle body formation. As a conclusion, UCH-L1 inhibitor LDN-57444 suppressed mouse oocyte maturation by improving oxidative stress, attenuating mitochondrial function, curbing spindle body formation and down-regulating extracellular signal-related kinases (ERK1/2) expression, providing a deep insight into the cellular and molecular basis of UCH-L1 during mouse oocyte maturation.

Targeting UCHL1 Induces Cell Cycle Arrest in High-Risk Multiple Myeloma with t(4;14)

Multiple myeloma (MM) patients considered to be at high cytogenetic risk commonly fail to respond to standard treatment. A thorough understanding of the molecular mechanism of MM development is, therefore, needed. We endeavored to explore the transcriptional signature among different subgroups of newly diagnosed MM using gene chip-based expression microarray. Bone marrow samples of 15 newly diagnosed Thai MM patients were included. The chromosomal translocation t(4;14) was the most frequently identified genetic alteration in the high-risk subgroup. Cluster analysis from expression profiling demonstrated that high-risk MM have a distinctly different expression pattern compared to standard-risk patients. The most significant differentially expressed gene was UCHL1. Functional enrichment analysis by Gene Set Enrichment Analysis, FUNRICH, and Gene Ontology Panther pathway revealed the gene sets involved in cell cycle control to be enriched in the t(4;14) high-risk group. Interestingly, among the well-established downstream targets of UCHL1, only CCND2 was significantly expressed in the t(4;14) high-risk group. Suppression of UCHL1 protein level by LDN-5744 inhibitor could arrest the cell cycle in G1 phase in cell lines. These findings shed light on the molecular mechanism of UCHL1 in t(4;14) high-risk MM and support the evidence that alteration of the UCHL1 pathway may play a role in the pathogenesis of high-risk MM.

Ubiquitin Carboxyl-Terminal Hydrolases and Human Malignancies: The Novel Prognostic and Therapeutic Implications for Head and Neck Cancer

Ubiquitin C-terminal hydrolases (UCHs), a subfamily of deubiquitinating enzymes (DUBs), have been found in a variety of tumor entities and play distinct roles in the pathogenesis and development of various cancers including head and neck cancer (HNC). HNC is a heterogeneous disease arising from the mucosal epithelia of the upper aerodigestive tract, including different anatomic sites, distinct histopathologic types, as well as human papillomavirus (HPV)-positive and negative subgroups. Despite advances in multi-disciplinary treatment for HNC, the long-term survival rate of patients with HNC remains low. Emerging evidence has revealed the members of UCHs are associated with the pathogenesis and clinical prognosis of HNC, which highlights the prognostic and therapeutic implications of UCHs for patients with HNC. In this review, we summarize the physiological and pathological functions of the UCHs family, which provides enlightenment of potential mechanisms of UCHs family in HNC pathogenesis and highlights the potential consideration of UCHs as attractive drug targets.

Mass spectrometry-based protein-protein interaction networks for the study of human diseases

A better understanding of the molecular mechanisms underlying disease is key for expediting the development of novel therapeutic interventions. Disease mechanisms are often mediated by interactions between proteins. Insights into the physical rewiring of protein-protein interactions in response to mutations, pathological conditions, or pathogen infection can advance our understanding of disease etiology, progression, and pathogenesis and can lead to the identification of potential druggable targets. Advances in quantitative mass spectrometry (MS)-based approaches have allowed unbiased mapping of these disease-mediated changes in protein-protein interactions on a global scale. Here, we review MS techniques that have been instrumental for the identification of protein-protein interactions at a system-level, and we discuss the challenges associated with these methodologies as well as novel MS advancements that aim to address these challenges. An overview of examples from diverse disease contexts illustrates the potential of MS-based protein-protein interaction mapping approaches for revealing disease mechanisms, pinpointing new therapeutic targets, and eventually moving toward personalized applications.

A simple, quick, and efficient CRISPR/Cas9 genome editing method for human induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) have become an essential research platform to study different human diseases once being discovered by Dr. Shinya Yamanaka in 2006. Another breakthrough in biomedical research is the application of CRISPR/Cas9 system for genome editing in mammalian cells. Although numerous studies have been done to develop methods for gene editing in iPSCs, the current approaches suffer from several limitations, including time and labor consuming, low editing efficiency, and potential off-target effects. In the current study, we report an electroporation-mediated plasmid CRISPR/Cas9 delivery approach for genome editing in iPSCs. With this approach, an edited iPSC cell line could be obtained within 2 weeks. In addition, the transit introducing of CRISPR/Cas9 machinery could minimize genomic integration of Cas9 gene, which avoided potential long-term side effects of Cas9 enzyme. We showed that CRISPR/Cas9-mediated genomic editing did not affect pluripotency and differentiation ability of iPSCs. With the quickly evolving of both iPSC and CRISPR/Cas9-mediated genome editing research fields, we believe that our method can significantly facilitate the application of genome editing in iPSCs research.

CiRS-7 functions as a ceRNA of RAF-1/PIK3CD to promote metastatic progression of oral squamous cell carcinoma via MAPK/AKT signaling pathways

PURPOSE

Recent findings have shown that circRNA dysregulation was involved in the development of many types of cancer. However, our knowledge of circRNA in oral squamous cell carcinoma (OSCC) remains elusive.

METHODS

Here, we explored whether ciRS-7 could function as a ceRNA in promoting metastasis of OSCC via regulating miR-7 activity. The expression levels of ciRS-7 and miR-7 were examined in clinical samples and cell lines by qRT-PCR, and the effects of ectopic expression of ciRS-7 and miR-7 on cell proliferation, migration and invasion were assessed in vitro and in vivo. The effects of ciRS-7 on miR-7 activity were investigated by means of luciferase reporter assay, qRT-PCR and Western blot. In addition, the effects of miR-7 mediated ciRS-7 on the levels of MAPK/AKT signaling proteins were evaluated by Western blot.

RESULTS

We found that ciRS-7 was highly expressed in OSCC tissues and cell lines compared with normal counterparts. Ectopic expression of ciRS-7 significantly promoted OSCC cell proliferation, migration and invasion through in vitro and in vivo. Based on bioinformatics analysis, qRT-PCR, Western blot and luciferase reporter assays, we determined that ciRS-7 functioned as a sponge for miR-7, resulting in attenuation of miR-7 targets RAF-1 and PIK3CD, which are core components of the MAPK/AKT signaling pathways. Moreover, miR-7 correlated with perineural and lymphovascular invasion in OSCC patients. Further experiments demonstrated that ciRS-7 overexpression could attenuate the anti-tumor effects of miR-7 on OSCC cells.

CONCLUSIONS

Our results suggested that ciRS-7 can interact directly with miR-7, resulting in upregulation of RAF-1/PIK3CD expression and enhancing metastatic progression of OSCC.

The evolutionarily conserved deubiquitinase UBH1/UCH-L1 augments DAF7/TGF-β signaling, inhibits dauer larva formation, and enhances lung tumorigenesis

Modification of the transforming growth factor β (TGF-β) signaling components by (de)ubiquitination is emerging as a key regulatory mechanism that controls cell signaling responses in health and disease. Here, we show that the deubiquitinating enzyme UBH-1 in Caenorhabditis elegans and its human homolog, ubiquitin C-terminal hydrolase-L1 (UCH-L1), stimulate DAF-7/TGF-β signaling, suggesting that this mode of regulation of TGF-β signaling is conserved across animal species. The dauer larva-constitutive C. elegans phenotype caused by defective DAF-7/TGF-β signaling was enhanced and suppressed, respectively, by ubh-1 deletion and overexpression in the loss-of-function genetic backgrounds of daf7, daf-1/TGF-βRI, and daf4/R-SMAD, but not of daf-8/R-SMAD. This suggested that UBH-1 may stimulate DAF-7/TGF-β signaling via DAF-8/R-SMAD. Therefore, we investigated the effect of UCH-L1 on TGF-β signaling via its intracellular effectors, i.e. SMAD2 and SMAD3, in mammalian cells. Overexpression of UCH-L1, but not of UCH-L3 (the other human homolog of UBH1) or of the catalytic mutant UCH-L1C90A, enhanced TGF-β/SMAD-induced transcriptional activity, indicating that the deubiquitination activity of UCH-L1 is indispensable for enhancing TGF-β/SMAD signaling. We also found that UCH-L1 interacts, deubiquitinates, and stabilizes SMAD2 and SMAD3. Under hypoxia, UCH-L1 expression increased and TGF-β/SMAD signaling was potentiated in the A549 human lung adenocarcinoma cell line. Notably, UCH-L1-deficient A549 cells were impaired in tumorigenesis, and, unlike WT UCH-L1, a UCH-L1 variant lacking deubiquitinating activity was unable to restore tumorigenesis in these cells. These results indicate that UCH-L1 activity supports DAF-7/TGF-β signaling and suggest that UCH-L1's deubiquitination activity is a potential therapeutic target for managing lung cancer.

LncRNA DRAIC inhibits proliferation and metastasis of gastric cancer cells through interfering with NFRKB deubiquitination mediated by UCHL5

Background

Long non-coding RNA (lncRNA) as a widespread and pivotal epigenetic molecule participates in the occurrence and progression of malignant tumors. DRAIC, a kind of lncRNA whose coding gene location is on 15q23 chromatin, has been found to be weakly expressed in a variety of malignant tumors and acts as a suppressor, but its characteristics and role in gastric cancer (GC) remain to be elucidated.

Methods

Sixty-seven primary GC tissues and paired paracancerous normal tissues were collected. Bioinformatics is used to predict the interaction molecules of DRAIC. DRAIC and NFRKB were overexpressed or interfered exogenously in GC cells by lentivirus or transient transfection. Quantitative real-time PCR (qPCR) and western blotting were used to evaluate the expression of DRAIC, UCHL5 and NFRKB. The combinations of DRAIC and NFRKB or UCHL5 and NFRKB were verified by RNA-IP and Co-IP assays. Ubiquitination-IP and the treatment of MG132 and CHX were used to detect the ubiquitylation level of NFRKB. The CCK-8 and transwell invasion and migration assays measured the proliferation, migration and invasion of GC cells.

Results

DRAIC is down-regulated in GC tissues and cell lines while its potential interacting molecules UCHL5 and NFRKB are up-regulated, and DRAIC is positively correlated with NFRKB protein instead of mRNA. Lower DRAIC and higher UCHL5 and NFRKB indicated advanced progression of GC patients. DRAIC could increase NFRKB protein significantly instead of NFRKB mRNA and UCHL5, and bind to UCHL5. DRAIC combined with UCHL5 and attenuated binding of UCHL5 and NFRKB, meanwhile promoting the degradation of NFRKB via ubiquitination, and then inhibited the proliferation and metastasis of GC cells, which can be rescued by oeNFRKB.

Conclusion

DRAIC suppresses GC proliferation and metastasis via interfering with the combination of UCHL5 and NFRKB and mediating ubiquitination degradation.

Clinical significance of promoter methylation status of tumor suppressor genes in circulating DNA of pancreatic cancer patients

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive cancer. There are various sub-cellular events (both genetic and epigenetic) that get dysregulated leading to tumorigenesis. Methylation in promoters of tumor suppressor genes is one of these epigenetic phenomena contributing to the pathogenesis of cancer. Genes analyzed for promoter methylation status in this study namely SPARC (Secreted Protein Acidic and Rich in Cysteine, UCHL1 (ubiquitin carboxy-terminal hydrolase L1), NPTX2 (neuronal pentraxin 2), PENK (proenkephalin) had been studied in pancreatic cancer, but there is a need to check methylation in these genes as circulatory non-invasive markers. This study analyzed the absolute quantification of methylation levels of SPARC, UCHL1, PENK, and NPTX2 genes promoters in PDAC patients as well as in chronic pancreatitis (CP) patients and healthy subjects (HC) and evaluated its clinical significance in PDAC.

MATERIALS AND METHODS

The study included 65 PDAC patients, 25 CP patients, and 25 healthy controls. DNA was extracted from their plasma samples and subsequently given bisulfite treatment. Absolute quantization of methylated and unmethylated copies of gene promoters of all the four genes was performed using real-time PCR (SYBR green) by the standard curve method. Methylation levels were expressed as methylation index (MI) for each gene in each patient. MI was calculated from absolute copy numbers as follows: MI-methylated copy number/methylated copy number + unmethylated copy number). These indices were used to compare gene methylation levels within different groups and to correlate with clinicopathological features and survival of pancreatic cancer patients. An appropriate statistical analysis was applied.

RESULTS

Methylation indices for all the four genes in PDAC cases were found to be significantly higher as compared to that in healthy individuals. SPARC MI values were found to differentiate early-stage PDAC patients from CP patients. PDAC patients with the metastasized disease and stage IV disease were found to have high MI for the SPARC gene as well as for the NPTX2 gene, while a higher UCHL1 methylation index was found to correlate with an advanced stage of the disease. Higher MI values for SPARC and NPTX2 genes were found to associate with poor survival in patients with PDAC.

CONCLUSION

Methylation load in the form of MI for each of the four genes assessed in plasma may emerge as a non-invasive biomarker to differentiate pancreatic cancer from healthy individuals. But only SPARC and NPTX2 hypermethylation were able to distinguish pancreatic cancer from chronic pancreatitis. Association of aberrant methylation in SPARC and NPTX2 gene with metastasis and poor survival of patients suggest the role of methylation in these genes as prognostic markers.

Extracellular Vesicles in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders: A Systematic Review

Extracellular vesicles (EVs) are secreted from most cell types and utilized in a complex network of near and distant cell-to-cell communication. Insight into this complex nanoscopic interaction in the development, progression and treatment of oral squamous cell carcinoma (OSCC) and precancerous oral mucosal disorders, termed oral potentially malignant disorders (OPMDs), remains of interest. In this review, we comprehensively present the current state of knowledge of EVs in OSCC and OPMDs. A systematic literature search strategy was developed and updated to December 17, 2019. Fifty-five articles were identified addressing EVs in OSCC and OPMDs with all but two articles published from 2015, highlighting the novelty of this research area. Themes included the impact of OSCC-derived EVs on phenotypic changes, lymph-angiogenesis, stromal immune response, mechanisms of therapeutic resistance as well as utility of EVs for drug delivery in OSCC and OPMD. Interest and progress of knowledge of EVs in OSCC and OPMD has been expanding on several fronts. The oral cavity presents a unique and accessible microenvironment for nanoparticle study that could present important models for other solid tumours.

UCH-L1-mediated Down-regulation of Estrogen Receptor α Contributes to Insensitivity to Endocrine Therapy for Breast Cancer

Purpose: To determine the role of UCH-L1 in regulating ERα expression, and to evaluate whether therapeutic targeting of UCH-L1 can enhance the efficacy of anti-estrogen therapy against breast cancer with loss or reduction of ERα.

Methods: Expressions of UCH-L1 and ERα were examined in breast cancer cells and patient specimens. The associations between UCH-L1 and ERα, therapeutic response and prognosis in breast cancer patients were analyzed using multiple databases. The molecular pathways by which UCH-L1 regulates ERα were analyzed using immunoblotting, qRT-PCR, immunoprecipitation, ubiquitination, luciferase and ChIP assays. The effects of UCH-L1 inhibition on the efficacy of tamoxifen in ERα (-) breast cancer cells were tested both in vivo and in vitro.

Results: UCH-L1 expression was conversely correlated with ERα status in breast cancer, and the negative regulatory effect of UCH-L1 on ERα was mediated by the deubiquitinase-mediated stability of EGFR, which suppresses ERα transcription. High expression of UCH-L1 was associated with poor therapeutic response and prognosis in patients with breast cancer. Up-regulation of ERα caused by UCH-L1 inhibition could significantly enhance the efficacy of tamoxifen and fulvestrant in ERα (-) breast cancer both in vivo and in vitro.

Conclusions: Our results reveal an important role of UCH-L1 in modulating ERα status and demonstrate the involvement of UCH-L1-EGFR signaling pathway, suggesting that UCH-L1 may serve as a novel adjuvant target for treatment of hormone therapy-insensitive breast cancers. Targeting UCH-L1 to sensitize ER negative breast cancer to anti-estrogen therapy might represent a new therapeutic strategy that warrants further exploration.

Inhibition of UCHL1 by LDN-57444 attenuates Ang II-Induced atrial fibrillation in mice

Atrial fibrillation (AF) is the most common human arrhythmia in clinical practice and may be promoted by atrial inflammation and fibrosis. Ubiquitination is an important posttranslational modification process that is reversed by deubiquitinating enzymes (DUBs). DUBs play critical roles in modulating the degradation, activity, trafficking, and recycling of substrates. However, less research has focused on the role of DUBs in AF. Here, we investigated the effect of ubiquitin C-terminal hydrolase 1 (UCHL1), an important DUB, on the development of AF induced by angiotensin II (Ang II). Male wild-type mice were treated with the UCHL1 inhibitor LDN57444 (LDN) at a dose of 40 μg/kg and infused with Ang II (2000 ng/kg/min) for 3 weeks. Our results showed that Ang II-infused wild-type (WT) mice had higher systolic blood pressure and an increased incidence and duration of AF. Conversely, this effect was attenuated in LDN-treated mice. Moreover, the administration of LDN significantly reduced Ang II-induced left atrial dilation, fibrosis, inflammatory cell infiltration, and reactive oxygen species (ROS) production. Mechanistically, LDN treatment inhibited the activation of multiple signaling pathways (the AKT, ERK1/2, HIF-1α, and TGF-β/smad2/3 pathways) and the expression of CX43 protein in atrial tissues compared with that in vehicle-treated control mice. Overall, our study identified UCHL1 as a novel regulator that contributes to Ang II-induced AF and suggests that the administration of LDN may represent a potential therapeutic approach for treating hypertensive AF.

The role of DUBs in the post-translational control of cell migration

Cell migration is a multifactorial/multistep process that requires the concerted action of growth and transcriptional factors, motor proteins, extracellular matrix remodeling and proteases. In this review, we focus on the role of transcription factors modulating Epithelial-to-Mesenchymal Transition (EMT-TFs), a fundamental process supporting both physiological and pathological cell migration. These EMT-TFs (Snail1/2, Twist1/2 and Zeb1/2) are labile proteins which should be stabilized to initiate EMT and provide full migratory and invasive properties. We present here a family of enzymes, the deubiquitinases (DUBs) which have a crucial role in counteracting polyubiquitination and proteasomal degradation of EMT-TFs after their induction by TGFβ, inflammatory cytokines and hypoxia. We also describe the DUBs promoting the stabilization of Smads, TGFβ receptors and other key proteins involved in transduction pathways controlling EMT.

Akt1 inhibition promotes breast cancer metastasis through EGFR-mediated β-catenin nuclear accumulation

Background

Knockdown of Akt1 promotes Epithelial-to-Mesenchymal Transition in breast cancer cells. However, the mechanisms are not completely understood.

Methods

Western blotting, immunofluorescence, luciferase assay, real time PCR, ELISA and Matrigel invasion assay were used to investigate how Akt1 inhibition promotes breast cancer cell invasion in vitro. Mouse model of lung metastasis was used to measure in vivo efficacy of Akt inhibitor MK2206 and its combination with Gefitinib.

Results

Knockdown of Akt1 stimulated β-catenin nuclear accumulation, resulting in breast cancer cell invasion. β-catenin nuclear accumulation induced by Akt1 inhibition depended on the prolonged activation of EGFR signaling pathway in breast cancer cells. Mechanistic experiments documented that knockdown of Akt1 inactivates PIKfyve via dephosphorylating of PIKfyve at Ser³¹⁸ site, resulting in a decreased degradation of EGFR signaling pathway. Inhibition of Akt1 using MK2206 could induce an increase in the expression of EGFR and β-catenin in breast cancer cells. In addition, MK2206 at a low dosage enhance breast cancer metastasis in a mouse model of lung metastasis, while an inhibitor of EGFR tyrosine kinase Gefitinib could potentially suppress breast cancer metastasis induced by Akt1 inhibition.

Conclusion

EGFR-mediated β-catenin nuclear accumulation is critical for Akt1 inhibition-induced breast cancer metastasis.

Overexpression of novel lncRNA NLIPMT inhibits metastasis by reducing phosphorylated glycogen synthase kinase 3β in breast cancer

Long noncoding RNAs (lncRNAs) are considered as regulators of gene expression in cancers. However, cancer profiling has little focused on noncoding genes. Here, we reported that RP11-115N4.1 (here renamed novel lncRNA inhibiting proliferation and metastasis [NLIPMT]) was downregulated in breast cancer tissues. Ectopic expression of NLIPMT inhibited mammary cell proliferation, motility in vitro. Moreover, lnc-NLIPMT reduced the growth of implanted MDA-MB-231 cells in vivo. Mechanistically, glycogen synthase kinase 3β (GSK3β) was identified as an effector protein regulated by lnc-NLIPMT. Inhibition of GSK3β activity restored NLIPMT-induced inhibition of proliferation and motility in breast cancer cells. These data reveal that lnc-NLIPMT functions as a driver of breast cancer progression and might serve as a potential target for antimetastatic therapies.

FBXO17 promotes cell proliferation through activation of Akt in lung adenocarcinoma cells

BACKGROUND

The ubiquitin-proteasome pathway, mediated in part, by ubiquitin E3 ligases, is critical in regulating cellular processes such as cell proliferation, apoptosis, and migration. FBXO17 was recently identified as an F-box protein that targets glycogen synthase kinase-3β to the E3 ubiquitin ligase protein complex for polyubiquitination and proteasomal degradation. Here, we identified that in several lung adenocarcinoma cell lines, FBXO17 cellular protein was detected at relatively high levels, as was expression in a subset of lung cancers. Hence, we investigated the effects of FBXO17 on cell proliferation.

METHODS

Single cell RNA sequencing analysis was performed on a resection of a non-small cell lung carcinoma tumor to examine FBXO17 expression. Multiple lung cancer cell lines were immunoblotted, and The Cancer Genome Atlas was analyzed to determine if FBXO17 expression was amplified in a subset of lung cancers. A549 cells were transfected with empty vector or FBXO17-V5 plasmid and immunoblotted for Akt pathway mediators including PDK1, ERK1/2, ribosomal protein S6, and CREB. Cell proliferation and viability were analyzed by trypan blue exclusion, BrdU incorporation and an MTS-based fluorometric assay. Studies were also performed after transfecting with sifbxo17. Samples were used in an RNA microarray analysis to evaluate pathways affected by reduced FBXO17 gene expression.

RESULTS

We observed that overexpression of FBXO17 increased A549 cell proliferation coupled with Akt activation. Ectopically expressed FBXO17 also increased ERK1/2 kinase activation and increased phosphorylation of RPS6, a downstream target of mTOR. We also observed an increased number of cells in S-phase and increased metabolic activity of lung epithelial cells expressing FBXO17. FBXO17 knockdown reduced Akt Ser 473 phosphorylation approaching statistical significance with no effect on Thr 308. However, ERK1/2 phosphorylation, cellular metabolic activity, and overall cell numbers were reduced. When we analyzed RNA profiles of A549 cells with reduced FBXO17 expression, we observed downregulation of several genes associated with cell proliferation and metabolism.

CONCLUSIONS

These data support a role for FBXO17 abundance, when left unchecked, in regulating cell proliferation and survival through modulation of Akt and ERK kinase activation. The data raise a potential role for the F-box subunit in modulating tumorigenesis.

Crosstalk in cancer resistance and metastasis

The main obstacles that lead to clinical failure in cancer treatment are the development of resistant to chemotherapy and a rise in invasive characteristics in cancer tumor cells due to prolonged chemotherapeutic processes. Recent studies have revealed some evidence about the existence of a direct relationship between development of drug resistance and triggering of invasive capability in tumor cells. Therefore, devising and application of chemotherapeutic procedures that are not prone to the development of chemotherapy resistance are necessary. Here, we focus on CD147, CD44, ANAX2, P-gp, MMPs, and UCH-L1 proteins involved in the crosstalk between metastasis and cancer treatment. We think that further structural and functional analysis of these proteins may direct scientists towards designing highly effective chemotherapy procedures.