Pharmaceutical targeting of OTUB2 sensitizes tumors to cytotoxic T cells via degradation of PD-L1

Uncovering global research frontiers in deubiquitinating enzymes and immunotherapy: A bibliometric study

Recently, immunotherapy has been a key therapeutic strategy for cancer. Deubiquitinating enzymes (DUBs), which are protein-modifying enzymes, have a crucial role in the pathogenesis of cancer, autoimmune diseases, and inflammation. DUBs influence the tumor immune microenvironment by regulating immune cell functions and key signaling pathways. Thus, the potential applications of DUBs in immunotherapy have piqued the interest of the scientific community. This study performed bibliometric analysis to comprehensively examine the research hotspots and trends in this field, providing theoretical foundations and guidance for future research. Studies associated with DUBs and immunotherapy conducted over a decade (2014 to 2024) were searched and extracted from Web of Science Collection database. The analysis was performed using CiteSpace, VOSviewer, and the Bibliometrix package in R software. Visualizations were generated for countries, institutions, authors, journals, references, and keyword co-occurrences. In total, 321 articles related to DUBs and immunotherapy were retrieved. The number of publications increased markedly since 2020. China had the highest number of publications, while the United States exerted the most influence in this field. Zhang Jinfang was the most influential author in this field. Zhejiang University was the institution with the highest number of publications. Nature was the most cited journal (807 total citations). Keyword analysis revealed that the primary research hotspots were expression, immunotherapy, ubiquitination, degradation, and cancer. This bibliometric analysis revealed the research trends and emerging frontiers in DUBs and immunotherapy, offering novel strategies for the application of DUBs in immunotherapy.

Programmed Death-1 Ligand 1 Domain Organization, Signaling Motifs, and Interactors in Cancer Immunotherapy

Immunotherapies targeting the programmed cell death-1 ligand 1 (PD-L1) and programmed cell death 1 (PD-1) pathway sparked a revolution in cancer treatment. These breakthrough therapies work by disrupting the interaction between PD-1-expressed on T cells-and its ligand PD-L1, commonly found on the surface of cancer cells. By using monoclonal antibodies to block this binding, the immune system is unleashed to fight cancer more effectively. However, PD-L1's role extends far beyond immune evasion. When situated on cancer cells, PD-L1 transmits inhibitory signals through PD-1, silencing the effector functions of T cells. However, PD-L1 also engages in reverse signaling, also called intrinsic signaling, delivering intracellular instructions that contribute to cancer cell survival, even in the absence of PD-1 binding. This signaling cascade shields cancer cells from apoptosis, drives proliferation, regulates DNA damage responses, and even functions as a co-transcriptional transactivator, amplifying cancer's ability to thrive. The intricate mechanisms behind PD-L1's intrinsic signaling are under intense investigation. In this review, we provide a historical perspective on the discoveries leading to PD-L1's structure, signaling motifs, and interacting partners, shedding light on its multifaceted roles and the promising therapeutic possibilities ahead.

KIF26B promotes bladder cancer progression via activating Wnt/β-catenin signaling in a TRAF2-dependent pathway

In this study, we report that KIF26B is upregulated in bladder cancer and acts as an independent prognostic factor. Knockdown of kif26b blocks the proliferation, metastasis, and cisplatin resistance of bladder cancer cells. Mechanistically, TCF4 potently stimulates kif26b transcription by directly binding to its promoter. KIF26B activates the Wnt/β-catenin signaling pathway through association with TRAF2 and thus promotes the formation of the TCF4/β-catenin complex. KIF26B promotes the protein stability of TRAF2 by facilitating the OTUB2-mediated de-ubiquitination of TRAF2. Importantly, KIF26B promotes the nuclear translocation of TRAF2 through enhancing its association with IPO11, a process that is dependent on the C-terminal domain of β-catenin. Additionally, phosphorylation of tyrosine 78 in TRAF2 is essential for its binding to KIF26B in response to Wnt3a signaling. Furthermore, a KIF26B/TRAF2/PD-L1 axis is identified in bladder cancer, and combined therapy of anti-B7-H3 antibody with kif26b knockdown yields superior anti-tumor effects.

OTUB2 promotes proliferation and metastasis of triple-negative breast cancer by deubiquitinating TRAF6

Objectives

Deubiquitinase OTUB2 plays a critical role in the progression of various tumors. However, its specific role in triple-negative breast cancer (TNBC) remains unclear. This study aims to elucidate the biological function of OTUB2 in TNBC and uncover the underlying mechanisms.

Methods

First, we found that the expression of OTUB2 was upregulated in TNBC by bioinformatics analysis, we then validated its expression in TNBC tissues and cells using immunohistochemistry (IHC) and qPCR and plotted the survival curves by Kaplan-Meier method. Gene set enrichment analysis (GSEA) suggested that OTUB2 may be involved in tumor proliferation and metastasis. Further functional assays, including Cell Counting Kit-8 (CCK-8), colony formation, Transwell, and wound healing assays, were performed to assess the effects of OTUB2 overexpression and knockdown on TNBC cell proliferation and migration. Additionally, UbiBrowser 2.0 was used to identify OTUB2 substrate proteins and western blotting was conducted to clarify the molecular mechanisms involved.

Results

Our results demonstrated that OTUB2 expression was elevated in TNBC and associated with poor prognosis. Overexpression of OTUB2 enhanced the proliferation and migration of TNBC cells, while its knockdown inhibited these processes. Moreover, OTUB2 stabilized tumor necrosis factor receptor-associated factor 6 (TRAF6) by deubiquitinating it, leading to activation of the protein kinase B (AKT) pathway.

Conclusions

OTUB2 exerts its promoting effects on the progression of TNBC by activating the TRAF6/AKT pathway.

Artificial Cation-Chloride Co-Transporters for Chloride-Facilitated Lithium/Magnesium Separation

Inspired by nature, many artificial ion sieving materials have been developed, shedding light on the next-generation ion, e.g., Li+, extraction applications. Artificial co-transporters remain difficult to construct since they have a much more complex ion-sieving property. For example, the cation-chloride co-transporters have both alkaline ion and chloride ion selectivity but no alkaline ion/chloride ion selectivity. We here demonstrate a method to construct artificial co-transporters, using a porous organic framework membrane which has a relatively disordered stacking structure and rich quaternary ammonium groups paired with counter-ions. This imparts the membrane with extremely narrow pores (∼0.3 nm) and almost no surface charge, enabling size-based high alkaline ion selectivity against other cations, high Cl- selectivity against other anions, but almost no alkaline ion/Cl- selectivity. Such synchronized sieving property allows us to enhance the extraction of high-value cations (Li+) by simply feeding excessive low-value anions (Cl-). As a demonstration, we realized high-flux (0.44 mol m-2 h-1) and highly selective (selectivity: 185) Li+/Mg2+ separation by reversing the current industrial brine-based lithium extraction process, i.e., sieving Li+ before removing NaCl.

Ubiquitin-conjugating enzyme E2S decreases the sensitivity of glioblastoma cells to temozolomide by upregulating PGAM1 via the interaction with OTUB2

BACKGROUND

Glioblastoma (GBM) is an aggressive cancer with limited therapeutic options. Investigating the mechanisms underlying temozolomide (TMZ) resistance and enhancing its sensitivity remain critical for improving GBM treatment outcomes. Ubiquitin-conjugating enzyme E2S (UBE2S) has been implicated in various cancers; however, its role in TMZ resistance in GBM remains unclear.

METHODS

After UBE2S knockdown, cell viability, apoptosis, and DNA damage were measured in TMZ-treated GBM cells. Immunoprecipitation coupled with mass spectrometry was employed to identify a protein complex involving UBE2S and phosphoglycerate mutase 1 (PGAM1). Co-immunoprecipitation and ubiquitination assays were conducted to examine the interactions among UBE2S, PGAM1, and Otubain-2 (OTUB2). In vivo, a GBM mouse model was used to evaluate the impact of UBE2S knockdown on TMZ efficacy.

RESULTS

UBE2S was found to be overexpressed in GBM cells, where it interacts with PGAM1 and OTUB2 to inhibit PGAM1 degradation via K48-linked deubiquitylation. This interaction increased PGAM1 protein levels, promoting DNA repair and reducing apoptosis, thereby decreasing the sensitivity of GBM cells to TMZ.

CONCLUSION

UBE2S plays a critical role in TMZ resistance by stabilizing PGAM1 protein levels through its interaction with OTUB2. Targeting UBE2S represents a promising therapeutic strategy to enhance TMZ efficacy and overcome chemotherapy resistance in GBM.

USP19 deficiency enhances T-cell-mediated antitumor immunity by promoting PD-L1 degradation in colorectal cancer

Colorectal cancer (CRC) is characterized by a highly immunosuppressive tumor microenvironment, which limits the effectiveness of current immunotherapies. Identifying strategies to overcome this resistance is critical for improving treatment outcomes. In this study, we discovered that USP19 plays a pivotal role in regulating T-cell-mediated antitumor immunity through a CRISPR/Cas9 sgRNA library screen and co-culture assays with activated T cells. We demonstrated that USP19 deficiency significantly enhances the susceptibility to T cell-mediated cytotoxicity in CRC cells, organoids, and mouse models. Transcriptomic sequencing (RNA-seq) revealed activation of the PD-1 pathway in tumor with USP19-deficiency cells. Mechanistic investigations revealed that USP19 directly stabilizes PD-L1 by binding to its intracellular domain and preventing its degradation via K48-linked ubiquitination and proteasomal pathways. Clinically, USP19 expression was found to be significantly elevated in CRC tissues and was positively associated with PD-L1 levels, advanced tumor grade, poor differentiation, and TP53 mutations, highlighting its potential as a biomarker for aggressive CRC. Importantly, in vivo experiments demonstrated that targeting USP19, in combination with αPD-L1 therapy, synergistically suppressed CRC progression. This combination not only reduced PD-L1 levels but also enhanced CD8+ T-cell activation and GzmB infiltration, resulting in robust antitumor effects. These findings establish USP19 as a key driver of immune evasion in CRC and suggest that targeting USP19 could enhance the efficacy of immunotherapy, providing a promising new avenue for CRC treatment.

Deubiquitination of RIPK3 by OTUB2 potentiates neuronal necroptosis after ischemic stroke

As a common and severe cerebrovascular disease, ischemic stroke casts a significant shadow over global health. Unfortunately, the mechanisms regulating neuronal death in the affected areas remain largely unclear. Here, we found that deletion of the deubiquitinating enzyme Otubain-2 (OTUB2) significantly alleviated ischemia-induced cerebral infarction and neurological deficits, accompanied by a reduction in neuronal loss, glial activation, and neuroinflammation. OTUB2 was predominantly expressed in neurons and its deletion decreased receptor-interacting protein kinase 3 (RIPK3)-mediated neuronal necroptosis. Moreover, OTUB2 increased RIPK3 protein abundance by inhibiting the proteasomal degradation of RIPK3. Mechanistically, OTUB2 removed K48-linked polyubiquitin chains from RIPK3 through its active site C51. Importantly, pharmacological inhibition of OTUB2 alleviated ischemic brain injury in mice and reduced oxygen-glucose deprivation-induced neuronal death in human brain organoids. These results demonstrate that OTUB2 critically regulates ischemic stroke injury by potentiating neuronal necroptosis, suggesting that OTUB2 inhibition may become a potential therapeutic approach for treating ischemic stroke.

Facile Integration of Bacterial Cellulose with Liquid Crystal Elastomers Enables Robust Biomimetic Helical Yarn Actuators

Inspired from helical structures in nature, liquid crystal elastomer (LCE) fiber actuators are developed for soft robotics and smart wearables. However, the facile development of robust LCE yarn actuators remains challenging due to the lightly cross-linked networks of LCE with the inherently poor mechanical properties. Here, the bionic helical yarn actuator is constructed through integrating the shape-morphing LCE fiber as the actuation phase and the highly ordered orientation biomass bacterial cellulose (BC) macrofibers as the reinforcement phase by a facile twisting and two-step cross-linking strategy. Thanks to the 3D nanofiber network inside BC macrofibers and biomimetic helical structure, the mechanical strength (43.9 MPa) and the creep phenomenon of the resulted yarn have been significantly improved, which are obviously better than the reported LCE fiber actuators (1.4-30.8 MPa). The designed LCE/BC helical yarn actuators demonstrate high work capacity (304.1 J kg-1) and reliable reusability. As a proof-of-concept, this work constructs micro rolling device with customizable speed, soft gripper for grasping and moving heavy objects and passive micro motor with a speed of 7.7 rad s-1. The findings of this work are expected to provide insights into the development of high-performance and durable smart yarn actuators through biomimetic engineering strategies.

Loss of MNX1 Sensitizes Tumors to Cytotoxic T Cells by Degradation of PD-L1 mRNA

Immune checkpoint blockade (ICB) therapy, targeting programmed cell death ligand-1 (PD-L1)/programmed cell death protein 1 (PD-1) axis and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), has exhibited amazing clinical outcomes in various types of cancers. However, only a small portion of patients benefit from ICB therapy, indicating that the mechanism underlying immune checkpoint is still unclear. Here, it is reported that motor neuron and pancreas homeobox 1 (MNX1), a homeobox domain-containing transcription factor, contributes to the tumor immune escape. MNX1 increases PD-L1 expression in cancer cells by stabilizing PD-L1 mRNA rather than activating transcription. Mechanistically, MNX1 exists in the cytoplasm of cancer cells and interacts with Y-box binding protein 1 (YBX1), a multifunctional DNA/RNA-binding protein, to enhance the binding of YBX1 to PD-L1 mRNA. MNX1 ablation activates cytotoxic T cell-mediated anti-tumor immunity and sensitizes CTLA-4 blockade therapy. Moreover, MNX1 also facilitates tumor progression in an immune-independent manner in cancer cells. In addition, MNX1 is upregulated by its adjacent long non-coding RNA MNX1-AS1 via HECT and RLD domain containing E3 ubiquitin protein ligase 2 (HERC2). Together, these results reveal MNX1 as a novel immune checkpoint regulator with promising therapeutic potential.

Identification of PLAC1 as a prognostic biomarker and molecular target in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common clinical tumor of the urinary system. The lack of effective diagnostic and treatment options poses a serious challenge to clinical treatment. Therefore, identifying effective molecular targets has become one of the potential means to treat this disease. Firstly, the analysis of the TCGA database found that PLAC1 was abnormally highly expressed in ccRCC and was negatively correlated with patient prognosis. Western blotting and immunofluorescence experiments further verified that PLAC1 was highly expressed in ccRCC patients, and knockdown of PLAC1 inhibited the development of ccRCC in vitro. Last, high-throughput virtual screening technology (HTVS) was performed to identify two molecular inhibitors ，AmB and Cana, which were able to reduce the expression of PLAC1 and inhibited the progression of ccRCC. In conclusion, the current investigation indicated that the PLAC1 could serve as a prognostic biomarker, and AmB and Cana inhibit the progression of ccRCC by reducing PLAC1, making it a potential therapeutic option for ccRCC.

OTUB2 contributes to vascular calcification in chronic kidney disease via the YAP-mediated transcription of PFKFB3

Rationale: Chronic kidney disease (CKD) is a global public health issue, with vascular calcification (VC) being a common and deadly complication. Despite its prevalence, the underlying mechanisms of VC remain unclear. In this study, we aimed to investigate whether and how Otubain-2 (OTUB2) contributes to VC. Methods: The relationship between OTUB2 and VC was examined via immunohistochemical and immunofluorescence staining of discarded calcified radial arteries from uremic patients who underwent arteriovenous fistula operations. Additionally, mice were fed a 0.2% adenine diet supplemented with 1.2% phosphorus to establish a model of CKD-related VC. Vascular smooth muscle cell (VSMC)-specific OTUB2 knockout and overexpression were performed in vivo via the delivery of adeno-associated virus 9 vectors to manipulate the expression of OTUB2. Additionally, a calcified VSMC model was established to explore the roles of OTUB2 in VC by evaluating changes in osteogenic marker expression and calcium deposition. Results: Our results revealed a significant upregulation of OTUB2 expression during VC progression. OTUB2 overexpression upregulated the expression of osteogenic markers and exacerbated VSMC calcification, as verified by Von Kossa and Alizarin red staining. Conversely, VSMC-specific OTUB2 deficiency significantly mitigated adenine diet-induced VC in CKD mice. OTUB2 knockdown or inhibition decreased Yes-associated protein (YAP) abundance. Mechanistically, OTUB2 bound to YAP, decreasing its K48-linked polyubiquitination and inhibiting its subsequent degradation. Knockdown or inhibition of YAP abolished the effect of OTUB2 overexpression on VSMC calcification, indicating a YAP-mediated mechanism. Furthermore, the YAP/TEAD1 complex bound to the promoter of PFKFB3, increasing its transcriptional activity, as determined by CUT&RUN-qPCR. The knockdown or inhibition of PFKFB3 alleviated the procalcific effects of OTUB2. Conclusions: Our findings indicate that OTUB2 promotes VC at least partially by activating the YAP-PFKFB3 signaling pathway. Targeting OTUB2 may be an appealing therapeutic strategy for VC.

Deubiquitinases as novel therapeutic targets for diseases

Deubiquitinating enzymes (DUBs) regulate substrate ubiquitination by removing ubiquitin or cleaving within ubiquitin chains, thereby maintaining cellular homeostasis. Approximately 100 DUBs in humans counteract E3 ubiquitin ligases, finely balancing ubiquitination and deubiquitination processes to maintain cellular proteostasis and respond to various stimuli and stresses. Given their role in modulating ubiquitination levels of various substrates, DUBs are increasingly linked to human health and disease. Here, we review the DUB family, highlighting their distinctive structural characteristics and chain-type specificities. We show that DUB family members regulate key signaling pathways, such as NF-κB, PI3K/Akt/mTOR, and MAPK, and play crucial roles in tumorigenesis and other diseases (neurodegenerative disorders, cardiovascular diseases, inflammatory disorders, and developmental diseases), making them promising therapeutic targets Our review also discusses the challenges in developing DUB inhibitors and underscores the critical role of the DUBs in cellular signaling and cancer. This comprehensive analysis enhances our understanding of the complex biological functions of the DUBs and underscores their therapeutic potential.

Deubiquitination of RIPK2 by OTUB2 augments NOD2 signalling and protective effects in intestinal inflammation

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, but the molecular mechanisms underlying IBD are incompletely understood. In this study, we explored the role and regulating mechanism of otubain 2 (OTUB2), a deubiquitinating enzyme, in IBD.

METHODS

To study the function of OTUB2 in IBD, we generated Otub2-/- mice and treated them with dextran sulfate sodium (DSS) to induce experimental colitis. Bone marrow transplantation was performed to identify the cell populations that were affected by OTUB2 in colitis. The molecular mechanism of OTUB2 in signal transduction was studied by various biochemical methods.

RESULTS

OTUB2 was highly expressed in colon-infiltrating macrophages in both humans with IBD and mice with DSS-induced experimental colitis. Colitis was significantly aggravated in Otub2-/- mice and bone marrow chimeric mice receiving Otub2-/- bone marrow. OTUB2-deficiency impaired the production of cytokines and chemokines in macrophages in response to the NOD2 agonist muramyl dipeptide (MDP). Upon MDP stimulation, OTUB2 promoted NOD2 signaling by stabilizing RIPK2. Mechanistically, OTUB2 inhibited the proteasomal degradation of RIPK2 by removing K48-linked polyubiquitination on RIPK2, which was mediated by the active C51 residue in OTUB2. In mice, OTUB2 ablation abolished the protective effects of MDP administration in colitis.

CONCLUSION

This study identified OTUB2 as a novel regulator of intestinal inflammation.

Research progress of the Otubains subfamily in hepatocellular carcinoma

In cancer research, oncogenesis can be affected by modulating the deubiquitination pathway. Ubiquitination regulates proteins post-translationally in variety of physiological processes. The Otubain Subfamily includes OTUB1 (ovarian tumor-associated proteinase B1) and OTUB2(ovarian tumor-associated proteinase B2). They are deubiquitinating enzymes, which are research hotspots in tumor immunotherapy, with their implications extending across the spectrum of tumor development. Understanding their important role in tumorigenesis, includ-ing hepatocellular carcinoma (HCC) is crucial. HCC has alarming global incidence rates and mortality statistics, ranking among the top five prevalent cancers in Malaysia1. Numerous studies have consistently indicated significant expression of OTUB1 and OTUB2 in HCC cells. In addition, OTUB1 has important biological functions in cancer, suggesting its important role in tumorigenesis. However, the mechanism underlying the action of OTUB1 and OTUB2 in liver cancer remains inadequately explored. Therefore, Otubain Subfamily, as potential molecular target, holds promise for advancing HCC treatments. However, further clinical studies are required to verify its efficacy and application prospects.

New horizons in the mechanisms and therapeutic strategies for PD-L1 protein degradation in cancer

Programmed death-ligand 1 (PD-L1) has become a crucial focus in cancer immunotherapy considering it is found in many different cells. Cancer cells enhance the suppressive impact of programmed death receptor 1 (PD-1) through elevating PD-L1 expression, which allows them to escape immune detection. Although there have been significant improvements, the effectiveness of anti-PD-1/PD-L1 treatment is still limited to a specific group of patients. An important advancement in cancer immunotherapy involves improving the PD-L1 protein degradation. This review thoroughly examined the processes by which PD-L1 breaks down, including the intracellular pathways of ubiquitination-proteasome and autophagy-lysosome. In addition, the analysis revealed changes that affect PD-L1 stability, such as phosphorylation and glycosylation. The significant consequences of these procedures on cancer immunotherapy and their potential role in innovative therapeutic approaches are emphasised. Our future efforts will focus on understanding new ways in which PD-L1 degradation is controlled and developing innovative treatments, such as proteolysis-targeting chimeras designed specifically to degrade PD-L1. It is crucial to have a thorough comprehension of these pathways in order to improve cancer immunotherapy strategies and hopefully improve therapeutic effectiveness.

Ubiquitin modification in the regulation of tumor immunotherapy resistance mechanisms and potential therapeutic targets

Although immune checkpoint-based cancer immunotherapy has shown significant efficacy in various cancers, resistance still limits its therapeutic effects. Ubiquitination modification is a mechanism that adds different types of ubiquitin chains to proteins, mediating protein degradation or altering their function, thereby affecting cellular signal transduction. Increasing evidence suggests that ubiquitination modification plays a crucial role in regulating the mechanisms of resistance to cancer immunotherapy. Drugs targeting ubiquitination modification pathways have been shown to inhibit tumor progression or enhance the efficacy of cancer immunotherapy. This review elaborates on the mechanisms by which tumor cells, immune cells, and the tumor microenvironment mediate resistance to cancer immunotherapy and the details of how ubiquitination modification regulates these mechanisms, providing a foundation for enhancing the efficacy of cancer immunotherapy by intervening in ubiquitination modification.

OTU deubiquitinase, ubiquitin aldehyde binding 2 (OTUB2) modulates the stemness feature, chemoresistance, and epithelial-mesenchymal transition of colon cancer via regulating GINS complex subunit 1 (GINS1) expression

BACKGROUND

Colon cancer is one of the most prevalent tumors in the digestive tract, and its stemness feature significantly contribute to chemoresistance, promote the epithelial-mesenchymal transition (EMT) process, and ultimately lead to tumor metastasis. Therefore, it is imperative for researchers to elucidate the molecular mechanisms underlying the enhancement of stemness feature, chemoresistance, and EMT in colon cancer.

METHODS

Sphere-formation and western blotting assays were conducted to assess the stemness feature. Edu, flow cytometry, and cell viability assays were employed to evaluate the chemoresistance. Immunofluorescence and western blotting assays were utilized to detect EMT. Immunoprecipitation, ubiquitination, agarose gel electrophoresis, chromatin immunoprecipitation followed by quantitative PCR (chip-qPCR), and dual luciferase reporter gene assays were employed for mechanistic investigations.

RESULTS

We demonstrated a markedly higher expression level of OTUB2 in colon cancer tissues compared to adjacent tissues. Furthermore, elevated OTUB2 expression was closely associated with poor prognosis and distant tumor metastasis. Functional experiments revealed that knockdown of OTUB2 attenuated stemness feature of colon cancer, enhanced its sensitivity to oxaliplatin, inhibited its EMT process, ultimately reduced the ability of tumor metastasis. Conversely, overexpression of OTUB2 exerted opposite effects. Mechanistically, we identified OTUB2 as a deubiquitinase for SP1 protein which bound specifically to SP1 protein, thereby inhibiting K48 ubiquitination of SP1 protein. The SP1 protein functioned as a transcription factor for the GINS1, exerting its regulatory effect by binding to the 1822-1830 region of the GINS1 promoter and enhancing its transcriptional activity. Ultimately, alterations in GINS1 expression directly regulated stemness feature, chemosensitivity, and EMT progression in colon cancer.

CONCLUSION

Collectively, the OTUB2/SP1/GINS1 axis played a pivotal role in driving stemness feature, chemoresistance, and EMT in colon cancer. These results shed new light on understanding chemoresistance and metastasis mechanisms involved in colon cancer.

PTMs of PD-1/PD-L1 and PROTACs application for improving cancer immunotherapy

Immunotherapy has been developed, which harnesses and enhances the innate powers of the immune system to fight disease, particularly cancer. PD-1 (programmed death-1) and PD-L1 (programmed death ligand-1) are key components in the regulation of the immune system, particularly in the context of cancer immunotherapy. PD-1 and PD-L1 are regulated by PTMs, including phosphorylation, ubiquitination, deubiquitination, acetylation, palmitoylation and glycosylation. PROTACs (Proteolysis Targeting Chimeras) are a type of new drug design technology. They are specifically engineered molecules that target specific proteins within a cell for degradation. PROTACs have been designed and demonstrated their inhibitory activity against the PD-1/PD-L1 pathway, and showed their ability to degrade PD-1/PD-L1 proteins. In this review, we describe how PROTACs target PD-1 and PD-L1 proteins to improve the efficacy of immunotherapy. PROTACs could be a novel strategy to combine with radiotherapy, chemotherapy and immunotherapy for cancer patients.