The post-translational modification, SUMOylation, and cancer (Review)

Targeted inhibition of SUMOylation: treatment of tumors

SUMOylation is a dynamic and reversible post-translational modification (PTM) of proteins involved in the regulation of biological processes such as protein homeostasis, DNA repair and cell cycle in normal and tumor cells. In particular, overexpression of SUMOylation components in tumor cells increases the activity of intracellular SUMOylation, protects target proteins against ubiquitination degradation and activation, promoting tumor cell proliferation and metastasis, providing immune evasion and increasing tolerance to chemotherapy and antitumor drugs. However, with the continuous research on SUMOylation and with the continued development of SUMOylation inhibitors, it has been found that tumor initiation and progression can be inhibited by blocking SUMOylation and/or in combination with drugs. SUMOylation is not a bad target when trying to treat tumor. This review introduces SUMOylation cycle pathway and summarizes the role of SUMOylation in tumor initiation and progression and SUMOylation inhibitors and their functions in tumors and provides a prospective view of SUMOylation as a new therapeutic target for tumors.

MITF regulates the subcellular location of HIF1α through SUMOylation to promote the invasion and metastasis of daughter cells derived from polyploid giant cancer cells

High concentrations of cobalt chloride (CoCl2) can induce the formation of polyploid giant cancer cells (PGCCs) in various tumors, which can produce daughter cells with strong proliferative, migratory and invasive abilities via asymmetric division. To study the role of hypoxia‑inducible factor (HIF) 1α in the formation of PGCCs, colon cancer cell lines Hct116 and LoVo were used as experimental subjects. Western blotting, nuclear and cytoplasmic protein extraction and immunocytochemical experiments were used to compare the changes in the expression and subcellular localization of HIF1α, microphthalmia‑associated transcription factor (MITF), protein inhibitor of activated STAT protein 4 (PIAS4) and von Hippel‑Lindau disease tumor suppressor (VHL) after treatment with CoCl2. The SUMOylation of HIFα was verified by co‑immunoprecipitation assay. After inhibiting HIF1α SUMOylation, the changes in proliferation, migration and invasion abilities of Hct116 and LoVo were compared by plate colony formation, wound healing and Transwell migration and invasion. In addition, lysine sites that led to SUMOylation of HIF1α were identified through site mutation experiments. The results showed that CoCl2 can induce the formation of PGCCs with the expression level of HIF1α higher in treated cells than in control cells. HIF1α was primarily located in the cytoplasm of control cell. Following CoCl2 treatment, the subcellular localization of HIF1α was primarily in the nuclei of PGCCs with daughter cells (PDCs). After treatment with SUMOylation inhibitors, the nuclear HIF1α expression in PDCs decreased. Furthermore, their proliferation, migration and invasion abilities also decreased. After inhibiting the expression of MITF, the expression of HIF1α decreased. MITF can regulate HIF1α SUMOylation. Expression and subcellular localization of VHL and HIF1α did not change following PIAS4 knockdown. SUMOylation of HIF1α occurs at the amino acid sites K391 and K477 in PDCs. After mutation of the two sites, nuclear expression of HIF1α in PDCs was reduced, along with a significant reduction in the proliferation, migration and invasion abilities. In conclusion, the post‑translation modification regulated the subcellular location of HIF1α and the nuclear expression of HIF1α promoted the proliferation, migration and invasion abilities of PDCs. MITF could regulate the transcription and protein levels of HIF1α and participate in the regulation of HIF1α SUMOylation.

The role of the master cancer regulator Pin1 in the development and treatment of cancer

This review examines the complex role of Pin1 in the development and treatment of cancer. Pin1 is the only peptidyl-prolyl isomerase (PPIase) that can recognize and isomerize phosphorylated Ser/Thr-Pro peptide bonds. Pin1 catalyzes a structural change in phosphorylated Ser/Thr-Pro motifs that can modulate protein function and thereby impact cell cycle regulation and tumorigenesis. The molecular mechanisms by which Pin1 contributes to oncogenesis are reviewed, including Pin1 overexpression and its correlation with poor cancer prognosis, and the contribution of Pin1 to aggressive tumor phenotypes involved in therapeutic resistance is discussed, with an emphasis on cancer stem cells, the epithelial-to-mesenchymal transition (EMT), and immunosuppression. The therapeutic potential of Pin1 inhibition in cancer is discussed, along with the promise and the difficulties in identifying potent, drug-like, small-molecule Pin1 inhibitors. The available evidence supports the efficacy of targeting Pin1 as a novel cancer therapeutic by analyzing the role of Pin1 in a complex network of cancer-driving pathways and illustrating the potential of synergistic drug combinations with Pin1 inhibitors for treating aggressive and drug-resistant tumors.

Identification of SUMOylation-related biomarkers in papillary thyroid carcinoma

BACKGROUND

Small ubiquitin-like modifier (SUMO) modification is increasingly recognized as critical in tumorigenesis and progression. This study identifies biomarkers linked to SUMOylation in papillary thyroid carcinoma (PTC), aiming to advance therapeutic and prognostic strategies.

METHODS

Employing PTC datasets and SUMO related genes (SRGs), we utilized univariate Cox regression for prognosis-related SRGs, conducted differential expression analyses, and integrated findings to pinpoint candidate genes. These genes underwent further validation through survival, gene set enrichment, immune infiltration, and drug sensitivity analyses, including external validation via quantitative RT-qPCR. In our final step, we conducted immunohistochemical staining on tumor samples from PTC patients at our center and integrated this with their clinical data to validate BMP8A's effectiveness in predicting recurrence in PTC.

RESULTS

Three biomarkers-BMP8A, RGS8, and SERPIND1-emerged as significant. Gene Set Enrichment Analysis (GSEA) showed their involvement in immune-related pathways, with differential immune infiltration patterns and drug response correlations observed, underscoring their potential for targeted therapy. Lastly, we validated the efficacy of BMP8A in predicting the recurrence of PTC in patients using clinical and pathological data from our center.

CONCLUSION

The study identifies BMP8A, RGS8, and SERPIND1 as key biomarkers associated with SUMOylation in PTC. Their linkage to immune response and drug sensitivity highlights their importance as targets for therapeutic intervention and prognosis in PTC research.

The crosstalk between SUMOylation and immune system in host-pathogen interactions

Pathogens can not only cause infectious diseases, immune system diseases, and chronic diseases, but also serve as potential triggers or initiators for certain tumors. They directly or indirectly damage human health and are one of the leading causes of global deaths. Small ubiquitin-like modifier (SUMO) modification, a type of protein post-translational modification (PTM) that occurs when SUMO groups bond covalently to particular lysine residues on substrate proteins, plays a crucial role in both innate and adaptive immunologic responses, as well as pathogen-host immune system crosstalk. SUMOylation participates in the host's defense against pathogens by regulating immune responses, while numerically vast and taxonomically diverse pathogens have evolved to exploit the cellular SUMO modification system to break through innate defenses. Here, we describe the characteristics and multiple functions of SUMOylation as a pivotal PTM mechanism, the tactics employed by various pathogens to counteract the immune system through targeting host SUMOylation, and the character of the SUMOylation system in the fight between pathogens and the host immune system. We have also included a summary of the potential anti-pathogen SUMO enzyme inhibitors. This review serves as a reference for basic research and clinical practice in the diagnosis, prognosis, and treatment of pathogenic microorganism-caused disorders.

The mechanism of USP43 in the development of tumor: a literature review

Ubiquitination of the proteins is crucial for governing protein degradation and regulating fundamental cellular processes. Deubiquitinases (DUBs) have emerged as significant regulators of multiple pathways associated with cancer and other diseases, owing to their capacity to remove ubiquitin from target substrates and modulate signaling. Consequently, they represent potential therapeutic targets for cancer and other life-threatening conditions. USP43 belongs to the DUBs family involved in cancer development and progression. This review aims to provide a comprehensive overview of the existing scientific evidence implicating USP43 in cancer development. Additionally, it will investigate potential small-molecule inhibitors that target DUBs that may have the capability to function as anti-cancer medicines.

SUMOylation regulation of ribosome biogenesis: Emerging roles for USP36

Ribosome biogenesis is essential for cell growth, proliferation, and animal development. Its deregulation leads to various human disorders such as ribosomopathies and cancer. Thus, tight regulation of ribosome biogenesis is crucial for normal cell homeostasis. Emerging evidence suggests that posttranslational modifications such as ubiquitination and SUMOylation play a crucial role in regulating ribosome biogenesis. Our recent studies reveal that USP36, a nucleolar deubiquitinating enzyme (DUB), acts also as a SUMO ligase to regulate nucleolar protein group SUMOylation, thereby being essential for ribosome biogenesis. Here, we provide an overview of the current understanding of the SUMOylation regulation of ribosome biogenesis and discuss the role of USP36 in nucleolar SUMOylation.

The prognosis, chemotherapy and immunotherapy efficacy of the SUMOylation pathway signature and the role of UBA2 in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the most common malignant tumors worldwide. Small Ubiquitin-like Modifier (SUMO)-ylation plays a crucial role in tumorigenesis. However, the SUMOylation pathway landscape and its clinical implications in LUAD remain unclear. Here, we analyzed genes involved in the SUMOylation pathway in LUAD and constructed a SUMOylation pathway signature (SUMOPS) using the LASSO-Cox regression model, validated in independent cohorts. Our analysis revealed significant dysregulation of SUMOylation-related genes in LUAD, comprising of favorable or unfavorable prognostic factors. The SUMOPS model was associated with established molecular and histological subtypes of LUAD, highlighting its clinical relevance. The SUMOPS stratified LUAD patients into SUMOPS-high and SUMOPS-low subtypes with distinct survival outcomes and adjuvant chemotherapy responses. The SUMOPS-low subtype showed favorable responses to adjuvant chemotherapy. The correlations between SUMOPS scores and immune cell infiltration suggested that patients with the SUMOPS-high subtype exhibited favorable immune profiles for immune checkpoint inhibitor (ICI) treatment. Additionally, we identified UBA2 as a key SUMOylation-related gene with an increased expression and a poor prognosis in LUAD. Cell function experiment confirmed the role of UBA2 in promoting LUAD cell proliferation, invasion, and migration. These findings provide valuable insights into the SUMOylation pathway and its prognostic implications in LUAD, paving the way for personalized treatment strategies and the development of novel therapeutic targets.

ROS-mediated up-regulation of SAE1 by Helicobacter pylori promotes human gastric tumor genesis and progression

Helicobacter pylori (H. pylori) is a major risk factor of gastric cancer (GC). The SUMO-activating enzyme SAE1(SUMO-activating enzyme subunit 1), which is indispensable for protein SUMOylation, involves in human tumorigenesis. In this study, we used the TIMER and TCGA database to explore the SAE1 expression in GC and normal tissues and Kaplan-Meier Plotter platform for survival analysis of GC patients. GC tissue microarray and gastric samples from patients who underwent endoscopic treatment were employed to detect the SAE1expression. Our results showed that SAE1 was overexpressed in GC tissues and higher SAE1 expression was associated with worse clinical characteristics of GC patients. Cell and animal models showed that H. pylori infection upregulated SAE1, SUMO1, and SUMO2/3 protein expression. Functional assays suggested that suppression of SAE1 attenuated epithelial-mesenchymal transition (EMT) biomarkers and cell proliferation abilities induced by H. pylori. Cell and animal models of ROS inhibition in H. pylori showed that ROS could mediate the H. pylori-induced upregulation of SAE1, SUMO1, and SUMO2/3 protein. RNA sequencing was performed and suggested that knockdown of SAE1 could exert an impact on IGF-1 expression. General, increased SUMOylation modification is involved in H. pylori-induced GC.

SUMOylation effects on neural stem cells self-renewal, differentiation, and survival

SUMO (small ubiquitin-like modifier) conjugation or SUMOylation, a post-translational modification, is a crucial regulator of protein function and cellular processes. In the context of neural stem cells (NSCs), SUMOylation has emerged as a key player, affecting their proliferation, differentiation, and survival. By modifying transcription factors, such as SOX1, SOX2, SOX3, SOX6, Bmi1, and Nanog, SUMOylation can either enhance or impair their transcriptional activity, thus impacting on NSCs self-renewal. Moreover, SUMOylation regulates neurogenesis and neuronal differentiation by modulating key proteins, such as Foxp1, Mecp2, MEF2A, and SOX10. SUMOylation is also crucial for the survival and proliferation of NSCs in both developing and adult brains. By regulating the activity of transcription factors, coactivators, and corepressors, SUMOylation acts as a molecular switch, inducing cofactor recruitment and function during development. Importantly, dysregulation of NSCs SUMOylation has been implicated in various disorders, including embryonic defects, ischemic cerebrovascular disease, glioma, and the harmful effects of benzophenone-3 exposure. Here we review the main findings on SUMOylation-mediated regulation of NSCs self-renewal, differentiation and survival. Better understanding NSCs SUMOylation mechanisms and its functional consequences might provide new strategies to promote neuronal differentiation that could contribute for the development of novel therapies targeting neurodegenerative diseases.

USP43 impairs cisplatin sensitivity in epithelial ovarian cancer through HDAC2-dependent regulation of Wnt/β-catenin signaling pathway

Epithelial ovarian cancer (EOC) is the leading cause of cancer death all over the world. USP43 functions as a tumor promoter in various malignant cancers. Nevertheless, the biological roles and mechanisms of USP43 in EOC remain unknown. In this study, USP43 was highly expressed in EOC tissues and cells, and high expression of USP43 were associated with a poor prognosis of EOC. USP43 overexpression promoted EOC cell proliferation, enhanced the ability of migration and invasion, decreased cisplatin sensitivity and inhibited apoptosis. Knockdown of USP43 in vitro effectively retarded above malignant progression of EOC. In vivo xenograft tumors, silencing USP43 slowed tumor growth and enhanced cisplatin sensitivity. Mechanistically, USP43 inhibited HDAC2 degradation and enhanced HDAC2 protein stability through its deubiquitylation function. USP43 diminished the sensitivity of EOC cells to cisplatin through activation of the Wnt/β-catenin signaling pathway mediated by HDAC2. Taken together, the data in this study revealed the functions of USP43 in proliferation, migration, invasion, chemoresistance of EOC cells, and the mechanism of HDAC2-mediated Wnt/β-catenin signaling pathway. Thus, USP43 might serve as a potential target for the control of ovarian cancer progression.

SENP1 inhibits ferroptosis and promotes head and neck squamous cell carcinoma by regulating ACSL4 protein stability via SUMO1

Head and neck squamous cell carcinoma (HNSCC) is currently one of the most common malignancies with a poor prognosis worldwide. Meanwhile, small ubiquitin‑like modifier (SUMO) specific peptidase 1 (SENP1) was associated with ferroptosis. However, the specific functions and underlying mechanisms of action of SENP1 in ferroptosis and tumor progression of HNSCC remain to be established. The findings of the present study implicated a novel ferroptosis pathway in the initiation and progression of HNSCC, providing new functional targets to guide future therapy. In the present study, The Cancer Genome Atlas database was employed to establish a gene model related to ferroptosis and verified SENP1 as a key gene via transcriptome sequencing. Expression of SENP1 in HNSCC tissue and CAL‑27 cells was detected based on reverse transcription‑quantitative PCR and western blot analysis. Proliferation and migration abilities of cells were determined using Cell Counting Kit‑8, wound healing and Transwell experiments. Expression levels of iron, glutathione (GSH) and lipid peroxidation end‑product malondialdehyde (MDA) under conditions of silencing of SENP1 with shRNA lentivirus were assayed. Additionally, the relationship between SENP1 and long‑chain acyl‑coenzyme A synthase 4 (ACSL4) was validated with the aid of immunoblotting and co‑immunoprecipitation (co‑IP). Finally, the influence of shSENP1 on the expression of key ferroptosis proteins, glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11, was evaluated via western blotting. It was revealed that SENP1 was significantly overexpressed in HNSCC and associated with low patient survival. Silencing of SENP1 led to significant suppression of cell proliferation, migration and invasion, increase in the contents of iron ions and MDA and decline in GSH levels in HNSCC cells, thereby enhancing ferroptosis and inhibiting disease progression. Conversely, overexpression of SENP1 suppressed ferroptosis and promoted progression of HNSCC. Co‑IP and western blot analyses revealed a SUMOylation link between SENP1 and ACSL4. SENP1 reduced the stability of ACSL4 protein through deSUMOylation, leading to inhibition of ferroptosis. SENP1 silencing further inhibited the expression of the key iron death protein, GPX4, to regulate ferroptosis. Taken together, SENP1 deficiency promoted ferroptosis and inhibited tumor progression through reduction of SUMOylation of ACSL4 in HNSCC. The collective results of the present study supported the utility of SENP1 as an effective predictive biomarker for targeted treatment of HNSCC.

Mechanisms and functions of SUMOylation in health and disease: a review focusing on immune cells

SUMOylation, which is a type of post-translational modification that involves covalent conjugation of small ubiquitin-like modifier (SUMO) proteins to target substrates, regulates various important molecular and cellular processes, including transcription, the cell cycle, cell signaling, and DNA synthesis and repair. Newly synthesized SUMO is immature and cleaved by the SUMO-specific protease family, resulting in exposure of the C-terminal Gly-Gly motif to become the mature form. In the presence of ATP, mature SUMO is conjugated with the activating enzyme E1 through the cysteine residue of E1, followed by transfer to the cysteine residue of E2-conjugating enzyme Ubc9 in humans that recognizes and modifies the lysine residue of a substrate protein. E3 SUMO ligases promote SUMOylation. SUMOylation is a reversible modification and mediated by SUMO-specific proteases. Cumulative studies have indicated that SUMOylation affects the functions of protein substrates in various manners, including cellular localization and protein stability. Gene knockout studies in mice have revealed that several SUMO cycling machinery proteins are crucial for the development and differentiation of various cell lineages, including immune cells. Aberrant SUMOylation has been implicated in several types of diseases, including cancers, cardiovascular diseases, and autoimmune diseases. This review summarizes the biochemistry of SUMO modification and the general biological functions of proteins involved in SUMOylation. In particular, this review focuses on the molecular mechanisms by which SUMOylation regulates the development, maturation, and functions of immune cells, including T, B, dendritic, and myeloid cells. This review also discusses the underlying relevance of disruption of SUMO cycling and site-specific interruption of SUMOylation on target proteins in immune cells in diseases, including cancers and infectious diseases.

The regulations of telomerase reverse transcriptase (TERT) in cancer

Abnormal activation of telomerase occurs in most cancer types, which facilitates escaping from cell senescence. As the key component of telomerase, telomerase reverse transcriptase (TERT) is regulated by various regulation pathways. TERT gene changing in its promoter and phosphorylation respectively leads to TERT ectopic expression at the transcription and protein levels. The co-interacting factors play an important role in the regulation of TERT in different cancer types. In this review, we focus on the regulators of TERT and these downstream functions in cancer regulation. Determining the specific regulatory mechanism will help to facilitate the development of a cancer treatment strategy that targets telomerase and cancer cell senescence. As the most important catalytic subunit component of telomerase, TERT is rapidly regulated by transcriptional factors and PTM-related activation. These changes directly influence TERT-related telomere maintenance by regulating telomerase activity in telomerase-positive cancer cells, telomerase assembly with telomere-binding proteins, and recruiting telomerase to the telomere. Besides, there are also non-canonical functions that are influenced by TERT, including the basic biological functions of cancer cells, such as proliferation, apoptosis, cell cycle regulation, initiating cell formation, EMT, and cell invasion. Other downstream effects are the results of the influence of transcriptional factors by TERT. Currently, some small molecular inhibitors of TERT and TERT vaccine are under research as a clinical therapeutic target. Purposeful work is in progress.

Regulation of PXR in drug metabolism: chemical and structural perspectives

INTRODUCTION

Pregnane X receptor (PXR) is a master xenobiotic sensor that transcriptionally controls drug metabolism and disposition pathways. PXR activation by pharmaceutical drugs, natural products, environmental toxins, etc. may decrease drug efficacy and increase drug-drug interactions and drug toxicity, indicating a therapeutic value for PXR antagonists. However, PXR's functions in physiological events, such as intestinal inflammation, indicate that PXR activators may be useful in certain disease contexts.

AREAS COVERED

We review the reported roles of PXR in various physiological and pathological processes including drug metabolism, cancer, inflammation, energy metabolism, and endobiotic homeostasis. We then highlight specific cellular and chemical routes that modulate PXR activity and discuss the functional consequences. Databases searched and inclusive dates: PubMed, 1 January 1980 to 10 January 2024.

EXPERT OPINION

Knowledge of PXR's drug metabolism function has helped drug developers produce small molecules without PXR-mediated metabolic liabilities, and further understanding of PXR's cellular functions may offer drug development opportunities in multiple disease settings.

A Systems Biology Approach Unveils a Critical Role of DPP4 in Upper Gastrointestinal Cancer Patient Outcomes

Gastrointestinal (GI) cancers comprise of cancers that affect the digestive system and its accessory organs. The late detection and poor prognosis of GI cancer emphasizes the importance of identifying reliable and precise biomarkers for early diagnosis and prediction of prognosis. The membrane-bound glycoprotein dipeptidyl-peptidase 4 (DPP4), also known as CD26, is ubiquitously expressed and has a wide spectrum of biological roles. The role of DPP4/CD26 in tumor progression in different types of cancers remains elusive. However, the link between DPP4 and tumor-infiltrating cells, as well as its prognostic significance in malignancies, still require further investigation. This study was intended to elucidate the correlation of DPP4 expression and survival along with prognosis, followed by its associated enriched molecular pathways and immune cell marker levels in upper GI cancers. Results demonstrated a strong correlation between increased DPP4 expression and a worse prognosis in esophageal and gastric cancer and the co-expressed common genes with DPP4 were associated with crucial molecular pathways involved in tumorigenesis. Additionally, DPP4 was shown to be significantly linked to several immune infiltrating cell marker genes, including Macrophages (M1, M2 and Tumor Associated Macrophages), neutrophils, Treg, T-cell exhaustion, Th1 and Th2. Overall, our findings suggest that DPP4 may serve as a substantial prognostic biomarker, a possible therapeutic target, as well as it can play a critical role in the regulation of immune cell invasion in patients with gastroesophageal (esophageal, gastroesophageal junction and gastric) cancer. KEY WORDS: DPP4, integrated analysis, GI cancer, gastroesophageal cancer, gastroesophageal junction, prognosis.

Overexpression of the Small Ubiquitin-Like Modifier protease OTS1 gene enhances drought tolerance in sugarcane (Saccharum spp. hybrid)

Sugarcane is an economically important crop plant across the globe as it is the primary source of sugar and biofuel. Its growth and development are greatly influenced by water availability; therefore, in periods of water scarcity, yields are severely compromised. Small Ubiquitin-Like Modifier (SUMO) proteases play an important role in stress responses by regulating the SUMO-related post-translational modification of proteins. In an attempt to enhance drought tolerance in sugarcane, this crop was genetically transformed with a cysteine protease (OVERLY TOLERANT TO SALT-1; OTS1) from Arabidopsis thaliana using particle bombardment. Transgenic plants were analysed in terms of photosynthetic capacity, oxidative damage, antioxidant accumulation and the SUMO-enrich protein profile was assessed. Sugarcane transformed with the AtOTS1 gene displayed enhanced drought tolerance and delayed leaf senescence under water deficit compared to the untransformed wild type (WT). The AtOTS1 transgenic plants maintained a high relative moisture content and higher photosynthesis rate when compared to the WT. In addition, when the transgene was expressed at high levels, the transformed plants were able to maintain higher stomatal conductance and chlorophyl content under moderate stress compared to the WT. Under severe water deficit stress, the transgenic plants accumulated less malondialdehyde and maintained membrane integrity. SUMOylation of total protein and protease activity was lower in the AtOTS1 transformed plants compared to the WT, with several SUMO-enriched proteins exclusively expressed in the transgenics when exposed to water deficit stress. SUMOylation of proteins likely influenced various mechanisms contributing to enhanced drought tolerance in sugarcane.

SUMOylation of RALY promotes vasculogenic mimicry in glioma cells via the FOXD1/DKK1 pathway

Human malignant gliomas are the most common and aggressive primary malignant tumors of the human central nervous system. Vasculogenic mimicry (VM), which refers to the formation of a tumor blood supply system independently of endothelial cells, contributes to the malignant progression of glioma. Therefore, VM is considered a potential target for glioma therapy. Accumulated evidence indicates that alterations in SUMOylation, a reversible post-translational modification, are involved in tumorigenesis and progression. In the present study, we found that UBA2 and RALY were upregulated in glioma tissues and cell lines. Downregulation of UBA2 and RALY inhibited the migration, invasion, and VM of glioma cells. RALY can be SUMOylated by conjugation with SUMO1, which is facilitated by the overexpression of UBA2. The SUMOylation of RALY increases its stability, which in turn increases its expression as well as its promoting effect on FOXD1 mRNA. The overexpression of FOXD1 promotes DKK1 transcription by activating its promoter, thereby promoting glioma cell migration, invasion, and VM. Remarkably, the combined knockdown of UBA2, RALY, and FOXD1 resulted in the smallest tumor volumes and the longest survivals of nude mice in vivo. UBA2/RALY/FOXD1/DKK1 axis may play crucial roles in regulating VM in glioma, which may contribute to the development of potential strategies for the treatment of gliomas.

Adenovirus E1B-55K controls SUMO-dependent degradation of antiviral cellular restriction factors

IMPORTANCE

Human adenoviruses (HAdVs) generally cause mild and self-limiting diseases of the upper respiratory and gastrointestinal tracts but pose a serious risk to immunocompromised patients and children. Moreover, they are widely used as vectors for vaccines and vector-based gene therapy approaches. It is therefore vital to thoroughly characterize HAdV gene products and especially HAdV virulence factors. Early region 1B 55 kDa protein (E1B-55K) is a multifunctional HAdV-encoded oncoprotein involved in various viral and cellular pathways that promote viral replication and cell transformation. We analyzed the E1B-55K dependency of SUMOylation, a post-translational protein modification, in infected cells using quantitative proteomics. We found that HAdV increases overall cellular SUMOylation and that this increased SUMOylation can target antiviral cellular pathways that impact HAdV replication. Moreover, we showed that E1B-55K orchestrates the SUMO-dependent degradation of certain cellular antiviral factors. These results once more emphasize the key role of E1B-55K in the regulation of viral and cellular proteins in productive HAdV infections.

Mechanistic update of Trisenox in blood cancer

Acute promyelocytic leukemia (APL)/blood cancer is M3 type of acute myeloid leukemia (AML) formed inside bone marrow through chromosomal translocation mutation usually between chromosome 15 & 17. It accounts around 10% cases of AML worldwide. Trisenox (TX/ATO) is used in chemotherapy for treatment of all age group of APL patients with highest efficacy and survival rate for longer period. High concentration of TX inhibits growth of APL cells by diverse mechanism however, it cures only PML-RARα fusion gene/oncogene containing APL patients. TX resistant APL patients (different oncogenic make up) have been reported from worldwide. This review summarizes updated mechanism of TX action via PML nuclear bodies formation, proteasomal degradation, autophagy, p53 activation, telomerase activity, heteromerization of pRb & E2F, and regulation of signaling mechanism in APL cells. We have also provided important information of combination therapy of TX with other molecules mechanism of action in acute leukemia cells. It provides updated information of TX action for researcher which may help finding new target for further research in APL pathophysiology or new TX resistant APL patients drug designing.

Protein modification regulated autophagy in Bombyx mori and Drosophila melanogaster

Post-translational modifications refer to the chemical alterations of proteins following their biosynthesis, leading to changes in protein properties. These modifications, which encompass acetylation, phosphorylation, methylation, SUMOylation, ubiquitination, and others, are pivotal in a myriad of cellular functions. Macroautophagy, also known as autophagy, is a major degradation of intracellular components to cope with stress conditions and strictly regulated by nutrient depletion, insulin signaling, and energy production in mammals. Intriguingly, in insects, 20-hydroxyecdysone signaling predominantly stimulates the expression of most autophagy-related genes while concurrently inhibiting mTOR activity, thereby initiating autophagy. In this review, we will outline post-translational modification-regulated autophagy in insects, including Bombyx mori and Drosophila melanogaster, in brief. A more profound understanding of the biological significance of post-translational modifications in autophagy machinery not only unveils novel opportunities for autophagy intervention strategies but also illuminates their potential roles in development, cell differentiation, and the process of learning and memory processes in both insects and mammals.

AKT1 induces Nanog promoter in a SUMOylation-dependent manner in different pluripotent contexts

AKT/PKB is a kinase crucial for pluripotency maintenance in pluripotent stem cells. Multiple post-translational modifications modulate its activity. We have previously demonstrated that AKT1 induces the expression of the pluripotency transcription factor Nanog in a SUMOylation-dependent manner in mouse embryonic stem cells. Here, we studied different cellular contexts and main candidates that could mediate this induction. Our results strongly suggest the pluripotency transcription factors OCT4 and SOX2 are not essential mediators. Additionally, we concluded that this induction takes place in different pluripotent contexts but not in terminally differentiated cells. Finally, the cross-matching analysis of ESCs, iPSCs and MEFs transcriptomes and AKT1 phosphorylation targets provided new clues about possible factors that could be involved in the SUMOylation-dependent Nanog induction by AKT.

The SUMOylation and ubiquitination crosstalk in cancer

BACKGROUND

The cancer occurrence and progression are largely affected by the post-translational modifications (PTMs) of proteins. Currently, it has been shown that the relationship between ubiquitination and SUMOylation is highly complex and interactive. SUMOylation affects the process of ubiquitination and degradation of substrates. Contrarily, SUMOylation-related proteins are also regulated by the ubiquitination process thus altering their protein levels or activity. Emerging evidence suggests that the abnormal regulation between this crosstalk may lead to tumorigenesis.

PURPOSE

In this review, we have discussed the study of the relationship between ubiquitination and SUMOylation, as well as the possibility of a corresponding application in tumor therapy.

METHODS

The relevant literatures from PubMed have been reviewed for this article.

CONCLUSION

The interaction between ubiquitination and SUMOylation is crucial for the occurrence and development of cancer. A greater understanding of the crosstalk of SUMOylation and ubiquitination may be more conducive to the development of more selective and effective SUMOylation inhibitors, as well as a promotion of synergy with other tumor treatment strategies.

Roles of host SUMOylation in bacterial pathogenesis

Bacteria frequently interfere with the post-translational modifications of host cells to facilitate their survival and growth after invasion. SUMOylation, a reversible post-translational modification process, plays an important role in biological life activities. In addition to being critical to host cell metabolism and survival, SUMOylation also regulates gene expression and cell signal transmission. Moreover, SUMOylation in eukaryotic cells can be used by a variety of bacterial pathogens to advance bacterial invasion. In this minireview, we focused on the role and mechanism of host SUMOylation in the pathogenesis of six important clinical bacterial pathogens (Listeria monocytogenes, Shigella flexneri, Salmonella Typhimurium, Klebsiella pneumoniae, Staphylococcus aureus, and Escherichia coli). Taken together, this review provided new insights for understanding the unique pathogen-host interaction based on host SUMOylation and provided a novel perspective on the development of new strategies to combat bacterial infections in the future.

Role of non-canonical post-translational modifications in gastrointestinal tumors

Post-translational modifications (PTMs) of proteins contribute to the occurrence and development of tumors. Previous studies have suggested that canonical PTMs such as ubiquitination, glycosylation, and phosphorylation are closely implicated in different aspects of gastrointestinal tumors. Recently, emerging evidence showed that non-canonical PTMs play an essential role in the carcinogenesis, metastasis and treatment of gastrointestinal tumors. Therefore, we summarized recent advances in sumoylation, neddylation, isoprenylation, succinylation and other non-canonical PTMs in gastrointestinal tumors, which comprehensively describe the mechanisms and functions of non-classical PTMs in gastrointestinal tumors. It is anticipated that targeting specific PTMs could benefit the treatment as well as improve the prognosis of gastrointestinal tumors.

SENP5 promotes homologous recombination-mediated DNA damage repair in colorectal cancer cells through H2AZ deSUMOylation

BACKGROUND

Neoadjuvant radiotherapy has been used as the standard treatment of colorectal cancer (CRC). However, radiotherapy resistance often results in treatment failure. To identify radioresistant genes will provide novel targets for combined treatments and prognostic markers.

METHODS

Through high content screening and tissue array from CRC patients who are resistant or sensitive to radiotherapy, we identified a potent resistant gene SUMO specific peptidase 5 (SENP5). Then, the effect of SENP5 on radiosensitivity was investigated by CCK8, clone formation, comet assay, immunofluorescence and flow cytometric analysis of apoptosis and cell cycle to investigate the effect of SENP5 on radiosensitivity. SUMO-proteomic mass spectrometry combined with co-immunoprecipitation assay were used to identify the targets of SENP5. Patient-derived organoids (PDO) and xenograft (PDX) models were used to explore the possibility of clinical application.

RESULTS

We identified SENP5 as a potent radioresistant gene through high content screening and CRC patients tissue array analysis. Patients with high SENP5 expression showed increased resistance to radiotherapy. In vitro and in vivo experiments demonstrated that SENP5 knockdown significantly increased radiosensitivity in CRC cells. SENP5 was further demonstrated essential for efficient DNA damage repair in homologous recombination (HR) dependent manner. Through SUMO mass spectrometry analysis, we characterized H2AZ as a deSUMOylation substrate of SENP5, and depicted the SUMOylation balance of H2AZ in HR repair and cancer resistance. By using PDO and PDX models, we found targeting SENP5 significantly increased the therapeutic efficacy of radiotherapy.

CONCLUSION

Our findings revealed novel role of SENP5 in HR mediated DNA damage repair and cancer resistance, which could be applied as potent prognostic marker and intervention target for cancer radiotherapy.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

Pan-cancer analysis of the PDE4DIP gene with potential prognostic and immunotherapeutic values in multiple cancers including acute myeloid leukemia

Phosphodiesterase 4D interacting protein (PDE4DIP) interacts with cAMP-specific phosphodiesterase 4D and its abnormal expression promotes the development of hematological malignancies, breast cancer, and pineal cell carcinoma. However, there is currently no systematic pan-cancer analysis of the association between PDE4DIP and various cancers. Thus, this study aimed to elucidate the potential functions of PDE4DIP in various cancers. Based on the multiple public databases and online websites, we conducted comprehensive analyses for PDE4DIP in various cancers, including differential expression, prognosis, genetic variation, DNA methylation, and immunity. We thoroughly analyzed the specific role of PDE4DIP in acute myeloid leukemia (LAML). The results indicated that there were differences in PDE4DIP expression in cancers, and in kidney chromophobe, LAML, pheochromocytoma and paraganglioma, thymoma, and uveal melanoma, PDE4DIP had potential prognostic value. PDE4DIP expression was also correlated with genetic variation, DNA methylation, immune cell infiltration, and immune-related genes in cancers. Functional enrichment analysis showed that PDE4DIP was mainly related to immune-related pathways in cancers, and in LAML, PDE4DIP was mainly related to immunoglobulin complexes, T-cell receptor complexes, and immune response regulatory signaling pathways. Our study systematically revealed for the first time the potential prognostic and immunotherapeutic value of PDE4DIP in various cancers, including LAML.

ERα promotes SUMO1 transcription by binding with the ERE and enhances SUMO1-mediated protein SUMOylation in breast cancer

Background

Estrogen plays a crucial role in the tumorigenesis of breast cancer (BC), and epigenetic modification by SUMOylation is essential for cancer development. However, the mechanism underlying estrogen's actions on protein SUMOylation and its effect on BC development are still incompletely understood.

Methods

SUMO1 in BC cell lines was verified via real-time quantitative PCR (RT-qPCR) and western blot. Cell proliferation and colony formation assays was also performed to evaluate SUMOylation as mediated by SUMO1. Luciferase activity to examine whether E2 promoted the transcription of SUMO1, and chromatin immunoprecipitation (ChIP) assay to determine the binding of estrogen receptor alpha (ERα) to SUMO1 were conduction, and an animal model was used to evaluate the effects of E2-ERα-enhanced SUMO1 transcription.

Results

E2 promoted SUMO1 mRNA and protein expression levels in a dose- and time-dependent manner in ER-positive BC cells; it exerted no influence on SUMO2/3 expression; in E2-induced SUMO1 transcription, ERα, but not ERβ, was essential to the process. In addition, E2-ERα upregulated the transcription of SUMO1 by binding with an estrogen-response element half-site (1/2ERE, in the -134 to -123 bp region) of the SUMO1 promoter, and E2-ERα induced SUMO1 transcription-enhanced cellular viability in ER-positive BC cells. To further determine SUMOylation as mediated by SUMO1 in ER-positive BC, we evaluated novel SUMO1 target proteins such as Ras and demonstrated that E2 increased Ras SUMOylation and cellular proliferation by affecting downstream signaling-pathway transduction. Finally, our data revealed that E2-ERα enhanced SUMO1 transcription to promote tumor growth in a BC orthotopic tumor model.

Conclusions

Collectively, our results showed that E2 promoted the transcription and protein expression of SUMO1 via ERα binding to a 1/2ERE in the SUMO1 promoter, and that E2-ERα also augmented SUMO1-mediated Ras SUMOylation and mediated cellular responses in ER-positive BC. We therefore achieved significant insights into the mechanism involved in ER-positive BC development and provided a novel target for its treatment.

The Role of P53 in Myocardial Ischemia-Reperfusion Injury

PURPOSE

P53 is one of the key tumor suppressors. In normal cells, p53 is maintained at low levels by the ubiquitination of the ubiquitinated ligase MDM2. In contrast, under stress conditions such as DNA damage and ischemia, the interaction between p53 and MDM2 is blocked and activated by phosphorylation and acetylation, thereby mediating the trans-activation of p53 through its target genes to regulate a variety of cellular responses. Previous studies have shown that the expression of p53 is negligible in normal myocardium, tends to increase in myocardial ischemia and is maximally induced in ischemia-reperfused myocardium, demonstrating a possible key role of p53 in the development of MIRI. In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and describe the therapeutic agents targeting the relevant targets to provide new strategies for the prevention and treatment of MIRI.

METHODS

We collected 161 relevant papers mainly from Pubmed and Web of Science (search terms "p53" and "myocardial ischemia-reperfusion injury"). After that, we selected pathway studies related to p53 and classified them according to their contents. We eventually analyzed and summarized them.

RESULTS AND CONCLUSION

In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and validate its status as an important intermediate affecting MIRI. On the one hand, p53 is regulated and modified by multiple factors, especially non-coding RNAs; on the other hand, p53 regulates apoptosis, programmed necrosis, autophagy, iron death and oxidative stress in MIRI through multiple pathways. More importantly, several studies have reported medications targeting p53-related therapeutic targets. These medications are expected to be effective options for the alleviation of MIRI, but further safety and clinical studies are needed to convert them into clinical applications.

Fundamental concepts of protein therapeutics and spacing in oncology: an updated comprehensive review

Current treatment regimens in cancer cases cause significant side effects and cannot effectively eradicate the advanced disease. Hence, much effort has been expended over the past years to understand how cancer grows and responds to therapies. Meanwhile, proteins as a type of biopolymers have been under commercial development for over three decades and have been proven to improve the healthcare system as effective medicines for treating many types of progressive disease, such as cancer. Following approving the first recombinant protein therapeutics by FDA (Humulin), there have been a revolution for drawing attention toward protein-based therapeutics (PTs). Since then, the ability to tailor proteins with ideal pharmacokinetics has provided the pharmaceutical industry with an important noble path to discuss the clinical potential of proteins in oncology research. Unlike traditional chemotherapy molecules, PTs actively target cancerous cells by binding to their surface receptors and the other biomarkers particularly associated with tumorous or healthy tissue. This review analyzes the potential and limitations of protein therapeutics (PTs) in the treatment of cancer as well as highlighting the evolving strategies by addressing all possible factors, including pharmacology profile and targeted therapy approaches. This review provides a comprehensive overview of the current state of PTs in oncology, including their pharmacology profile, targeted therapy approaches, and prospects. The reviewed data show that several current and future challenges remain to make PTs a promising and effective anticancer drug, such as safety, immunogenicity, protein stability/degradation, and protein-adjuvant interactions.

Current understanding of the cGAS-STING signaling pathway: Structure, regulatory mechanisms, and related diseases

The innate immune system protects the host from external pathogens and internal damage in various ways. The cGAS-STING signaling pathway, comprised of cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and downstream signaling adaptors, plays an essential role in protective immune defense against microbial DNA and internal damaged-associated DNA and is responsible for various immune-related diseases. After binding with DNA, cytosolic cGAS undergoes conformational change and DNA-linked liquid-liquid phase separation to produce 2'3'-cGAMP for the activation of endoplasmic reticulum (ER)-localized STING. However, further studies revealed that cGAS is predominantly expressed in the nucleus and strictly tethered to chromatin to prevent binding with nuclear DNA, and functions differently from cytosolic-localized cGAS. Detailed delineation of this pathway, including its structure, signaling, and regulatory mechanisms, is of great significance to fully understand the diversity of cGAS-STING activation and signaling and will be of benefit for the treatment of inflammatory diseases and cancer. Here, we review recent progress on the above-mentioned perspectives of the cGAS-STING signaling pathway and discuss new avenues for further study.

Regulation of SUMOylation on RNA metabolism in cancers

Post-translational modifications of proteins play very important roles in regulating RNA metabolism and affect many biological pathways. Here we mainly summarize the crucial functions of small ubiquitin-like modifier (SUMO) modification in RNA metabolism including transcription, splicing, tailing, stability and modification, as well as its impact on the biogenesis and function of microRNA (miRNA) in particular. This review also highlights the current knowledge about SUMOylation regulation in RNA metabolism involved in many cellular processes such as cell proliferation and apoptosis, which is closely related to tumorigenesis and cancer progression.

Ubiquitin-Specific Protease 43 Impacts Pancreatic Ductal Adenocarcinoma Prognosis by Altering Its Proliferation and Infiltration of Surrounding Immune Cells

Background

Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer, and the therapy options for PDAC remain restricted. The distinctive tumor immunological microenvironment (TIME) of PDAC, comprising a high number of stromal cells and a limited infiltration of cytotoxic T lymphocytes (CTLs), rendered immunotherapy ineffective. The protein level of ubiquitin-specific protease 43 (USP43) was a prognostic predictor in numerous cancers; however, its function in PDAC is limited. This article focuses on the influence of USP43 expression on PDAC prognosis and TIME alteration.

Methods

Based on TCGA database and tissue microarray staining, the expression of USP43 in PDAC was evaluated. The association between USP43 and prognosis was then investigated using tissue samples and online databases. In PDAC tumor tissues, the correlation between USP43 expression and clinicopathological characteristics, immune cell infiltration, and prognosis was investigated. The expression of USP43 in PDAC cell lines was evaluated using quantitative polymerase chain reaction. Using a cell counting kit-8 (CCK-8) and a cell colony formation test, the viability of the cells was determined. On the basis of online databases and tissue samples, the link between USP43 and immune cell infiltration around PDAC was also examined. For statistical analyses, the software GraphPad, R, and SPSS 26.0 were utilized.

Results

The expression of USP43 was considerably higher in PDAC compared to normal pancreatic tissue in both the TCGA database and the tissue microarrays of PDAC patients (P < 0.001). High USP43 expression was associated with poor overall survival in both the TCGA database and the tissue microarray of PDAC patients (P = 0.046 and 0.021, respectively). USP43 overexpression promoted PANC-1 cell proliferation (P = 0.0018), but USP43 knockdown decreased PANC02 cell proliferation (P < 0.001). According to the TCGA database, USP43 is associated with T cell activation and inhibits CD8⁺ T cell activation in PDAC, as proven by a study of cell lines. Moreover, in both TCGA and PDAC cell lines, USP43 expression was negatively linked with the chemokine signaling pathway.

Conclusions

Overexpression of USP43 is a potential prognostic indicator for PDAC patients. USP43 is a potential biomarker associated with T cell activation, suppression of CD8⁺ T cell enrichment, and the cytokine signal pathway. Future multicenter studies are needed to confirm our findings and their potential application in the treatment of PDAC patients.

The role of SUMOylation in the neurovascular dysfunction after acquired brain injury

Acquired brain injury (ABI) is the most common disease of the nervous system, involving complex pathological processes, which often leads to a series of nervous system disorders. The structural destruction and dysfunction of the Neurovascular Unit (NVU) are prominent features of ABI. Therefore, understanding the molecular mechanism underlying NVU destruction and its reconstruction is the key to the treatment of ABI. SUMOylation is a protein post-translational modification (PTM), which can degrade and stabilize the substrate dynamically, thus playing an important role in regulating protein expression and biological signal transduction. Understanding the regulatory mechanism of SUMOylation can clarify the molecular mechanism of the occurrence and development of neurovascular dysfunction after ABI and is expected to provide a theoretical basis for the development of potential treatment strategies. This article reviews the role of SUMOylation in vascular events related to ABI, including NVU dysfunction and vascular remodeling, and puts forward therapeutic prospects.

Sumoylation participates in the regulation of YB-1-mediated mismatch repair deficiency and alkylator tolerance

Numerous reports indicate that enhanced expression of Y-box binding protein-1 (YB-1) in tumor cells is strongly associated with tumorigenesis, aggressiveness, drug resistance, as well as poor prognosis in several types of cancers, and YB-1 is considered to be an oncogene. The molecular mechanism contributing to the regulation of the biological activities of YB-1 remains obscure. Sumoylation, a post-translational modification involving the covalent conjugation of small ubiquitin-like modifier (SUMO) proteins to a target protein, plays key roles in the modulation of protein functions. In this study, our results revealed that YB-1 is sumoylated and that Lys²⁶ is a critical residue for YB-1 sumoylation. Moreover, YB-1 was found to directly interact with SUMO proteins, and disruption of the SUMO-interacting motif (SIM) of YB-1 not only interfered with this interaction but also diminished YB-1 sumoylation. The subcellular localization, protein stability, and transcriptional regulatory activity of YB-1 were not significantly affected by sumoylation. However, decreased sumoylation disrupted the interaction between YB-1 and PCNA as well as YB-1-mediated inhibition of the MutSα/PCNA interaction and MutSα mismatch binding activity, indicating a functional role of YB-1 sumoylation in inducing DNA mismatch repair (MMR) deficiency and spontaneous mutations. The MMR machinery also recognizes alkylator-modified DNA adducts to signal for cell death. We further demonstrated that YB-1 sumoylation is crucial for the inhibition of S_N1-type alkylator MNNG-induced cytotoxicity, G2/M-phase arrest, apoptosis, and the MMR-dependent DNA damage response. Collectively, these results provide molecular explanations for the impact of YB-1 sumoylation on MMR deficiency and alkylator tolerance, which may provide insight for designing therapeutic strategies for malignancies and alkylator-resistant cancers associated with YB-1 overexpression.

cGAS in nucleus: The link between immune response and DNA damage repair

As the first barrier of host defense, innate immunity sets up the parclose to keep out external microbial or virus attacks. Depending on the type of pathogens, several cytoplasm pattern recognition receptors exist to sense the attacks from either foreign or host origins, triggering the immune response to battle with the infections. Among them, cGAS-STING is the major pathway that mainly responds to microbial DNA, DNA virus infections, or self-DNA, which mainly comes from genome instability by-product or released DNA from the mitochondria. cGAS was initially found functional in the cytoplasm, although intriguing evidence indicates that cGAS exists in the nucleus where it is involved in the DNA damage repair process. Because the close connection between DNA damage response and immune response and cGAS recognizes DNA in length-dependent but DNA sequence-independent manners, it is urgent to clear the function balance of cGAS in the nucleus versus cytoplasm and how it is shielded from recognizing the host origin DNA. Here, we outline the current conception of immune response and the regulation mechanism of cGAS in the nucleus. Furthermore, we will shed light on the potential mechanisms that are restricted to be taken away from self-DNA recognition, especially how post-translational modification regulates cGAS functions.

Upregulated UBE4B expression correlates with poor prognosis and tumor immune infiltration in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a major human health concern. Increasing evidence has demonstrated that ubiquitin ligase E4B (UBE4B) may be involved in the occurrence and development of various human cancers and may affect prognosis. However, the specific role and mechanism of UBE4B in HCC is unclear.

METHODS

A pan-cancer analysis of UBE4B expression, clinicopathological features, and prognosis was performed using bioinformatics techniques. Subsequently, the expression, prognosis, and correlation of UBE4B and its upstream miRNAs and lncRNAs were analyzed. We investigated the relationship between UBE4B expression and immune cell infiltration, immunomodulatory factors, and chemokines in HCC. The expression levels of UBE4B and its upstream lncRNAs (FGD5-AS1, LINC00858, and SNHG16) and miRNAs (hsa-miR-22-3p) were evaluated in HCC cell lines using qRT-PCR.

RESULTS

UBE4B expression increased in HCC and was correlated with a poor survival rate in patients with HCC. A ceRNA network was established to identify the UBE4B-hsa-miR-22-3p-FGD5-AS1/LINC00858/SNHG16 regulatory axis in HCC. UBE4B expression was significantly associated with immune cell infiltration, immunomodulators, chemokines, and their receptors in HCC. The mRNA expression of FGD5-AS1, LINC00858, SNHG16, and UBE4B was higher in the HCC cell lines (7721 and HepG2) than in the normal hepatocyte line (LO2), and the expression of hsa-miR-22-3p mRNA showed a decreasing trend.

CONCLUSIONS

Our findings showed that upregulation of UBE4B was associated with poor prognosis and tumor immune infiltration in HCC. These findings will aid in understanding the relevant functions of UBE4B and provide new strategies for drug development and exploration of prognosis-related biomarkers.

SUMO-specific protease 1 inhibitors-A literature and patent overview

INTRODUCTION

Cancer is currently one of the biggest killers threatening human health. More and more studies have confirmed that SUMO-specific protease 1 (SENP1) is over-expressed in various cancer tissues. Therefore, targeting SENP1 expression may become a new strategy for tumor therapy.

AREAS COVERED

This review reports the latest advances in literature and patents on SENP1 inhibitor development over the past 10 years. With SENP1 as the keyword, articles and patents from PubMed, Google scholar and ScienceDirect databases were covered.

EXPERT OPINION

The available complex crystal structures of SENP1-SUMO1, afforded structure-based drug design opportunities, which led to the development of various isoform-selective small molecule inhibitors belonging to diverse classes (derivatives of benzamides, naphthalenesulfonic acids, pyridones, and the like). Preclinical studies have initially shown the potential advantages of these compounds, which have certain significance for the development of anticancer drugs.

The post-translational modification of Fascin: impact on cell biology and its associations with inhibiting tumor metastasis

The post-translational modifications (PTMs), which are crucial in the regulation of protein functions, have great potential as biomarkers of cancer status. Fascin (Fascin actin-bundling protein 1, FSCN1), a key protein in the formation of filopodia that is structurally based on actin filaments (F-actin), is significantly associated with tumor invasion and metastasis. Studies have revealed various regulatory mechanisms of human Fascin, including PTMs. Although a number of Fascin PTM sites have been identified, their exact functions and clinical significance are much less explored. This review explores studies on the functions of Fascin and briefly discusses the regulatory mechanisms of Fascin. Next, to review the role of Fascin PTMs in cell biology and their associations with metastatic disease, we discuss the advances in the characterization of Fascin PTMs, including phosphorylation, ubiquitination, sumoylation, and acetylation, and the main regulatory mechanisms are discussed. Fascin PTMs may be potential targets for therapy for metastatic disease.

Post-Translational Modification of ZEB Family Members in Cancer Progression

Post-translational modification (PTM), the essential regulatory mechanisms of proteins, play essential roles in physiological and pathological processes. In addition, PTM functions in tumour development and progression. Zinc finger E-box binding homeobox (ZEB) family homeodomain transcription factors, such as ZEB1 and ZEB2, play a pivotal role in tumour progression and metastasis by induction epithelial-mesenchymal transition (EMT), with activation of stem cell traits, immune evasion and epigenetic reprogramming. However, the relationship between ZEB family members' post-translational modification (PTM) and tumourigenesis remains largely unknown. Therefore, we focussed on the PTM of ZEBs and potential therapeutic approaches in cancer progression. This review provides an overview of the diverse functions of ZEBs in cancer and the mechanisms and therapeutic implications that target ZEB family members' PTMs.

RNA Modifications Meet Tumors

RNA modifications occur through the whole process of gene expression regulation, including transcription, translation, and post-translational processes. They are closely associated with gene expression, RNA stability, and cell cycle. RNA modifications in tumor cells play a vital role in tumor development and metastasis, changes in the tumor microenvironment, drug resistance in tumors, construction of tumor cell-cell "internet", etc. Several types of RNA modifications have been identified to date and have various effects on the biological characteristics of different tumors. In this review, we discussed the function of RNA modifications, including N 6-methyladenine (m6A), 5-methylcytosine (m5C), N 7-methyladenosine (m7G), N 1-methyladenosine (m1A), pseudouridine (Ψ), and adenosine-to-inosine (A-to-I), in the microenvironment and therapy of solid and liquid tumors.

The Four Homeostasis Knights: In Balance upon Post-Translational Modifications

A cancer outcome is a multifactorial event that comes from both exogenous injuries and an endogenous predisposing background. The healthy state is guaranteed by the fine-tuning of genes controlling cell proliferation, differentiation, and development, whose alteration induces cellular behavioral changes finally leading to cancer. The function of proteins in cells and tissues is controlled at both the transcriptional and translational level, and the mechanism allowing them to carry out their functions is not only a matter of level. A major challenge to the cell is to guarantee that proteins are made, folded, assembled and delivered to function properly, like and even more than other proteins when referring to oncogenes and onco-suppressors products. Over genetic, epigenetic, transcriptional, and translational control, protein synthesis depends on additional steps of regulation. Post-translational modifications are reversible and dynamic processes that allow the cell to rapidly modulate protein amounts and function. Among them, ubiquitination and ubiquitin-like modifications modulate the stability and control the activity of most of the proteins that manage cell cycle, immune responses, apoptosis, and senescence. The crosstalk between ubiquitination and ubiquitin-like modifications and post-translational modifications is a keystone to quickly update the activation state of many proteins responsible for the orchestration of cell metabolism. In this light, the correct activity of post-translational machinery is essential to prevent the development of cancer. Here we summarize the main post-translational modifications engaged in controlling the activity of the principal oncogenes and tumor suppressors genes involved in the development of most human cancers.

The Global research of protein post-translational modifications in the cancer field: A bibliometric and visualized study

Objectives

Protein post-translational modifications (PTMs) are closely associated with tumorigenesis, targeting PTMs of key proteins might be the focus of antitumor drug discovery. This study aimed to analyze the research progress on protein PTMs in tumorigenesis by performing qualitative and quantitative evaluations.

Methods

The Web of Science Core Collection was selected as the database, and Science Citation Index Expanded was selected as the citation index. Visualization tools such as VOSviewer, CiteSpace, HistCite, and Online Analysis Platform of Bibliometrics were used to deeply explore the information of the retrieved research papers and analyze them in terms of research trends and main aspects of research.

Results

The search yielded 3777 relevant articles. The results showed that the total number of PTMs related papers in cancer field has been increasing annually, with the largest number of papers published in the United States of America. The co-word cluster analysis showed that the research on PTMs and tumorigenesis was primarily focused on the following four areas, mechanism, histone, P53, key Technologies. Tumor metabolism, autophagy, and protein-protein interaction, histone ubiquitination have become new research topics.

Conclusion

This study provides an important reference for the research direction and selection of topics of interest in the PTMs of cancer field.

Role of SUMOylation in Neurodegenerative Diseases

Neurodegenerative diseases (NDDs) are irreversible, progressive diseases with no effective treatment. The hallmark of NDDs is the aggregation of misfolded, modified proteins, which impair neuronal vulnerability and cause brain damage. The loss of synaptic connection and the progressive loss of neurons result in cognitive defects. Several dysregulated proteins and overlapping molecular mechanisms contribute to the pathophysiology of NDDs. Post-translational modifications (PTMs) are essential regulators of protein function, trafficking, and maintaining neuronal hemostasis. The conjugation of a small ubiquitin-like modifier (SUMO) is a reversible, dynamic PTM required for synaptic and cognitive function. The onset and progression of neurodegenerative diseases are associated with aberrant SUMOylation. In this review, we have summarized the role of SUMOylation in regulating critical proteins involved in the onset and progression of several NDDs.

Farnesoid-X receptor as a therapeutic target for inflammatory bowel disease and colorectal cancer

Farnesoid-X receptor (FXR), as a nuclear receptor activated by bile acids, is a vital molecule involved in bile acid metabolism. Due to its expression in immune cells, FXR has a significant effect on the function of immune cells and the release of chemokines when immune cells sense changes in bile acids. In addition to its regulation by ligands, FXR is also controlled by post-translational modification (PTM) activities such as acetylation, SUMOylation, and methylation. Due to the high expression of FXR in the liver and intestine, it significantly influences intestinal homeostasis under the action of enterohepatic circulation. Thus, FXR protects the intestinal barrier, resists bacterial infection, reduces oxidative stress, inhibits inflammatory reactions, and also acts as a tumor suppressor to impair the multiplication and invasion of tumor cells. These potentials provide new perspectives on the treatment of intestinal conditions, including inflammatory bowel disease (IBD) and its associated colorectal cancer (CRC). Moreover, FXR agonists on the market have certain organizational heterogeneity and may be used in combination with other drugs to achieve a greater therapeutic effect. This review summarizes current data on the role of FXR in bile acid metabolism, regulation of immune cells, and effects of the PTM of FXR. The functions of FXR in intestinal homeostasis and potential application in the treatment of IBD and CRC are discussed.

Role of K63-linked ubiquitination in cancer

Ubiquitination is a critical type of post-translational modifications, of which K63-linked ubiquitination regulates interaction, translocation, and activation of proteins. In recent years, emerging evidence suggest involvement of K63-linked ubiquitination in multiple signaling pathways and various human diseases including cancer. Increasing number of studies indicated that K63-linked ubiquitination controls initiation, development, invasion, metastasis, and therapy of diverse cancers. Here, we summarized molecular mechanisms of K63-linked ubiquitination dictating different biological activities of tumor and highlighted novel opportunities for future therapy targeting certain regulation of K63-linked ubiquitination in tumor.

Combined Evaluation of mRNA and Protein Expression, Promoter Methylation, and Immune Infiltration of UBE2I in Pan-Digestive System Tumors

Background

Digestive system tumors (DSTs) have high morbidity and mortality worldwide. This study explored the potential value of ubiquitin-conjugating enzyme E2 I (UBE2I) in pan-digestive system tumors (pan-DSTs).

Methods

Differential expression, tumor stages, and survival outcomes of UBE2I in pan-DSTs were determined using the GEPIA database. The TIMER database was used to confirm the correlation of UBE2I expression with pan-DSTs and immune infiltrates. Differential analyses of UBE2I promoter methylation and protein levels were performed using the UALCAN database. The underlying mechanisms of UBE2I involvement in pan-DSTs were visualized using interaction networks. The diagnostic value of UBE2I in pan-DSTs was identified using the Oncomine database.

Results

UBE2I was differentially and highly expressed in cholangiocarcinoma (CHOL), pancreatic adenocarcinoma (PAAD), colon adenocarcinoma (COAD), rectal adenocarcinoma (READ), liver hepatocellular carcinoma (LIHC), and stomach adenocarcinoma (STAD). According to survival analysis, upregulated UBE2I was associated with adverse overall and disease-free survival in PAAD and favorable overall survival in READ. UBE2I expression was partially linked to the purity of immune infiltration in COAD, LIHC, PAAD, READ, and STAD, as indicated by the immune infiltration analysis. Promoter methylation analysis showed differential and high methylation of UBE2I in PAAD as well as stratified analysis by gender, nodal metastasis, and race. Protein expression analysis in colon cancer revealed that UBE2I had differential and high expression in tumors as well as stratified analysis by gender, tumor histology, race, and tumor stage. Mechanism explorations demonstrated that in COAD and PAAD, UBE2I was involved in spliceosomal snRNP complex, Notch signaling pathway, etc. Diagnostic analysis indicated that UBE2I had consistent diagnostic value for COAD and PAAD.

Conclusions

Upregulated UBE2I may be a diagnostic and surveillance predictive signature for PAAD and COAD. The potential significance of immune infiltrates and promoter methylation in PAAD and COAD needs further exploration.

Neddylation pattern indicates tumor microenvironment characterization and predicts prognosis in lung adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is the most common type of lung cancer with a complex tumor microenvironment. Neddylation, as a type of post-translational modification, plays a vital role in the development of LUAD. To date, no study has explored the potential of neddylation-associated genes for LUAD classification, prognosis prediction, and treatment response evaluation.

Methods: Seventy-six neddylation-associated prognostic genes were identified by Univariate Cox analysis. Patients with LUAD were classified into two patterns based on unsupervised consensus clustering analysis. In addition, a 10-gene prognostic signature was constructed using LASSO-Cox and a multivariate stepwise regression approach.

Results: Substantial differences were observed between the two patterns of LUAD in terms of prognosis. Compared with neddylation cluster2, neddylation cluster1 exhibited low levels of immune infiltration that promote tumor progression. Additionally, the neddylation-related risk score correlated with clinical parameters and it can be a good predictor of patient outcomes, gene mutation levels, and chemotherapeutic responses.

Conclusion: Neddylation patterns can distinguish tumor microenvironment and prognosis in patients with LUAD. Prognostic signatures based on neddylation-associated genes can predict patient outcomes and guide personalized treatment.