USP44 regulates irradiation-induced DNA double-strand break repair and suppresses tumorigenesis in nasopharyngeal carcinoma

Ubiquitination and deubiquitination in cancer: from mechanisms to novel therapeutic approaches

Ubiquitination, a pivotal posttranslational modification of proteins, plays a fundamental role in regulating protein stability. The dysregulation of ubiquitinating and deubiquitinating enzymes is a common feature in various cancers, underscoring the imperative to investigate ubiquitin ligases and deubiquitinases (DUBs) for insights into oncogenic processes and the development of therapeutic interventions. In this review, we discuss the contributions of the ubiquitin-proteasome system (UPS) in all hallmarks of cancer and progress in drug discovery. We delve into the multiple functions of the UPS in oncology, including its regulation of multiple cancer-associated pathways, its role in metabolic reprogramming, its engagement with tumor immune responses, its function in phenotypic plasticity and polymorphic microbiomes, and other essential cellular functions. Furthermore, we provide a comprehensive overview of novel anticancer strategies that leverage the UPS, including the development and application of proteolysis targeting chimeras (PROTACs) and molecular glues.

DCAF7 Acts as A Scaffold to Recruit USP10 for G3BP1 Deubiquitylation and Facilitates Chemoresistance and Metastasis in Nasopharyngeal Carcinoma

Despite docetaxel combined with cisplatin and 5-fluorouracil (TPF) being the established treatment for advanced nasopharyngeal carcinoma (NPC), there are patients who do not respond positively to this form of therapy. However, the mechanisms underlying this lack of benefit remain unclear. DCAF7 is identified as a chemoresistance gene attenuating the response to TPF therapy in NPC patients. DCAF7 promotes the cisplatin resistance and metastasis of NPC cells in vitro and in vivo. Mechanistically, DCAF7 serves as a scaffold protein that facilitates the interaction between USP10 and G3BP1, leading to the elimination of K48-linked ubiquitin moieties from Lys76 of G3BP1. This process helps prevent the degradation of G3BP1 via the ubiquitin‒proteasome pathway and promotes the formation of stress granule (SG)-like structures. Moreover, knockdown of G3BP1 successfully reversed the formation of SG-like structures and the oncogenic effects of DCAF7. Significantly, NPC patients with increased levels of DCAF7 showed a high risk of metastasis, and elevated DCAF7 levels are linked to an unfavorable prognosis. The study reveals DCAF7 as a crucial gene for cisplatin resistance and offers further understanding of how chemoresistance develops in NPC. The DCAF7-USP10-G3BP1 axis contains potential targets and biomarkers for NPC treatment.

The circadian gene ARNTL2 promotes nasopharyngeal carcinoma invasiveness and metastasis through suppressing AMOTL2-LATS-YAP pathway

Metastasis is the major culprit of treatment failure in nasopharyngeal carcinoma (NPC). Aryl hydrocarbon receptor nuclear translocator like 2 (ARNTL2), a core circadian gene, plays a crucial role in the development of various tumors. Nevertheless, the biological role and mechanism of ARNTL2 are not fully elucidated in NPC. In this study, ARNTL2 expression was significantly upregulated in NPC tissues and cells. Overexpression of ARNTL2 facilitated NPC cell migration and invasion abilities, while inhibition of ARNTL2 in similarly treated cells blunted migration and invasion abilities in vitro. Consistently, in vivo xenograft tumor models revealed that ARNTL2 silencing reduced nude mice inguinal lymph node and lung metastases, as well as tumor growth. Mechanistically, ARNTL2 negatively regulated the transcription expression of AMOTL2 by directly binding to the AMOTL2 promoter, thus reducing the recruitment and stabilization of AMOTL2 to LATS1/2 kinases, which strengthened YAP nuclear translocation by suppressing LATS-dependent YAP phosphorylation. Inhibition of AMOTL2 counteracted the effects of ARNTL2 knockdown on NPC cell migration and invasion abilities. These findings suggest that ARNTL2 may be a promising therapeutic target to combat NPC metastasis and further supports the crucial roles of circadian genes in cancer development.

PJA1-mediated suppression of pyroptosis as a driver of docetaxel resistance in nasopharyngeal carcinoma

Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in nasopharyngeal carcinoma remains to be elucidated. Here, we identify PJA1 as a key E3 ubiquitin ligase involved in nasopharyngeal carcinoma chemoresistance that is highly expressed in nasopharyngeal carcinoma patients with nonresponse to docetaxel-cisplatin-5-fluorouracil induction chemotherapy. We find that PJA1 facilitates docetaxel resistance by inhibiting GSDME-mediated pyroptosis in nasopharyngeal carcinoma cells. Mechanistically, PJA1 promotes the degradation of the mitochondrial protein PGAM5 by increasing its K48-linked ubiquitination at K88, which further facilitates DRP1 phosphorylation at S637 and reduced mitochondrial reactive oxygen species production, resulting in suppression of GSDME-mediated pyroptosis and the antitumour immune response. PGAM5 knockdown fully restores the docetaxel sensitization effect of PJA1 knockdown. Moreover, pharmacological targeting of PJA1 with the small molecule inhibitor RTA402 enhances the docetaxel sensitivity of nasopharyngeal carcinoma in vitro and in vivo. Clinically, high PJA1 expression indicates inferior survival and poor clinical efficacy of TPF IC in nasopharyngeal carcinoma patients. Our study emphasizes the essential role of E3 ligases in regulating chemoresistance and provides therapeutic strategies for nasopharyngeal carcinoma based on targeting the ubiquitin-proteasome system.

CD20highCD138low tumor-infiltrating lymphocytes predominantly related to cytokine‒cytokine receptor interactions are associated with favorable outcomes in neuroblastoma patients

Recent advances have revealed that the role of the immune system is prominent in the antitumor response. In the present study, it is aimed to provide an expression profile of tumor-infiltrating lymphocytes (TILs), including mature B cells, plasma cells, and their clinical relevance in neuroblastoma. The expression of CD20 and CD138 was analyzed in the Cangelosi786 dataset (n = 769) as a training dataset and in our cohort (n = 120) as a validation cohort. CD20 high expression was positively associated with favorable overall survival (OS) and event-free survival (EFS) (OS: P < 0.001; EFS: P < 0.001) in the training dataset, whereas CD138 high expression was associated with poor OS and EFS (OS: P < 0.001; EFS: P < 0.001) in both the training and validation datasets. Accordingly, a combined pattern of CD20 and CD138 expression was developed, whereby neuroblastoma patients with CD20highCD138low expression had a consistently favorable OS and EFS compared with those with CD20lowCD138high expression in both the training and validation cohorts (P < 0.0001 and P < 0.01, respectively). Examination of potential molecular functions revealed that signaling pathways, including cytokine‒cytokine receptor interactions, chemokine, and the NF-kappa B signaling pathways, were involved. Differentially expressed genes, such as BMP7, IL7R, BIRC3, CCR7, CXCR5, CCL21, and CCL19, predominantly play important roles in predicting the survival of neuroblastoma patients. Our study proposes that a new combination of CD20 and CD138 signatures is associated with neuroblastoma patient survival. The related signaling pathways reflect the close associations among the number of TILs, cytokine abundance and patient outcomes and provide therapeutic insights into neuroblastoma.

Exploring the Enigma: The Role of the Epithelial Protein Lost in Neoplasm in Normal Physiology and Cancer Pathogenesis

The cytoskeleton plays a pivotal role in maintaining the epithelial phenotype and is vital to several hallmark processes of cancer. Over the past decades, researchers have identified the epithelial protein lost in neoplasm (EPLIN, also known as LIMA1) as a key regulator of cytoskeletal dynamics, cytoskeletal organization, motility, as well as cell growth and metabolism. Dysregulation of EPLIN is implicated in various aspects of cancer progression, such as tumor growth, invasion, metastasis, and therapeutic resistance. Its altered expression levels or activity can disrupt cytoskeletal dynamics, leading to aberrant cell motility and invasiveness characteristic of malignant cells. Moreover, the involvement of EPLIN in cell growth and metabolism underscores its significance in orchestrating key processes essential for cancer cell survival and proliferation. This review provides a comprehensive exploration of the intricate roles of EPLIN across diverse cellular processes in both normal physiology and cancer pathogenesis. Additionally, this review discusses the possibility of EPLIN as a potential target for anticancer therapy in future studies.

High expression of PPP1CC promotes NHEJ-mediated DNA repair leading to radioresistance and poor prognosis in nasopharyngeal carcinoma

Protein phosphatase 1 catalytic subunit gamma (PPP1CC) promotes DNA repair and tumor development and progression, however, its underlying mechanisms remain unclear. This study investigated the molecular mechanism of PPP1CC's involvement in DNA repair and the potential clinical implications. High expression of PPP1CC was significantly correlated with radioresistance and poor prognosis in human nasopharyngeal carcinoma (NPC) patients. The mechanistic study revealed that PPP1CC bound to Ku70/Ku80 heterodimers and activated DNA-PKcs by promoting DNA-PK holoenzyme formation, which enhanced nonhomologous end junction (NHEJ) -mediated DNA repair and led to radioresistance. Importantly, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) interacted with PPP1CC to enhance its stability by removing the K48-linked polyubiquitin chain at Lys234 to prevent PPP1CC degradation. Therefore, BRCC3 helped the overexpressed PPP1CC to maintain its high protein level, thereby sustaining the elevation of DNA repair capacity and radioresistance. Our study identified the molecular mechanism by which PPP1CC promotes NHEJ-mediated DNA repair and radioresistance, suggesting that the BRCC3-PPP1CC-Ku70 axis is a potential therapeutic target to improve the efficacy of radiotherapy.

CircCDYL2 bolsters radiotherapy resistance in nasopharyngeal carcinoma by promoting RAD51 translation initiation for enhanced homologous recombination repair

BACKGROUND

Radiation therapy stands to be one of the primary approaches in the clinical treatment of malignant tumors. Nasopharyngeal Carcinoma, a malignancy predominantly treated with radiation therapy, provides an invaluable model for investigating the mechanisms underlying radiation therapy resistance in cancer. While some reports have suggested the involvement of circRNAs in modulating resistance to radiation therapy, the underpinning mechanisms remain unclear.

METHODS

RT-qPCR and in situ hybridization were used to detect the expression level of circCDYL2 in nasopharyngeal carcinoma tissue samples. The effect of circCDYL2 on radiotherapy resistance in nasopharyngeal carcinoma was demonstrated by in vitro and in vivo functional experiments. The HR-GFP reporter assay determined that circCDYL2 affected homologous recombination repair. RNA pull down, RIP, western blotting, IF, and polysome profiling assays were used to verify that circCDYL2 promoted the translation of RAD51 by binding to EIF3D protein.

RESULTS

We have identified circCDYL2 as highly expressed in nasopharyngeal carcinoma tissues, and it was closely associated with poor prognosis. In vitro and in vivo experiments demonstrate that circCDYL2 plays a pivotal role in promoting radiotherapy resistance in nasopharyngeal carcinoma. Our investigation unveils a specific mechanism by which circCDYL2, acting as a scaffold molecule, recruits eukaryotic translation initiation factor 3 subunit D protein (EIF3D) to the 5'-UTR of RAD51 mRNA, a crucial component of the DNA damage repair pathway to facilitate the initiation of RAD51 translation and enhance homologous recombination repair capability, and ultimately leads to radiotherapy resistance in nasopharyngeal carcinoma.

CONCLUSIONS

These findings establish a novel role of the circCDYL2/EIF3D/RAD51 axis in nasopharyngeal carcinoma radiotherapy resistance. Our work not only sheds light on the underlying molecular mechanism but also highlights the potential of circCDYL2 as a therapeutic sensitization target and a promising prognostic molecular marker for nasopharyngeal carcinoma.

CBX7 reprograms metabolic flux to protect against meningioma progression by modulating the USP44/c-MYC/LDHA axis

Meningioma is one of the most common primary neoplasms in the central nervous system, but no specific molecularly targeted therapy has been approved for the clinical treatment of aggressive meningiomas. There is hence an urgent demand to decrypt the biological and molecular landscape of malignant meningioma. Here, through the in-silica prescreening and 10-year follow-up studies of 445 meningioma patients, we uncovered that CBX7 expression progressively decreases with malignancy grade and neoplasia stage in meningioma, and a high CBX7 expression level predicts a favorable prognosis in meningioma patients. CBX7 restoration significantly induces cell cycle arrest and inhibits meningioma cell proliferation. iTRAQ-based proteomics analysis indicated that CBX7 restoration triggers the metabolic shift from glycolysis to oxidative phosphorylation. The mechanistic study demonstrated that CBX7 promotes the proteasome-dependent degradation of c-MYC protein by transcriptionally inhibiting the expression of a c-MYC deubiquitinase, USP44, consequently attenuates c-MYC-mediated transactivation of LDHA transcripts, and further inhibits glycolysis and subsequent cell proliferation. More importantly, the functional role of CBX7 was further confirmed in subcutaneous and orthotopic meningioma xenograft mouse models and meningioma patients. Altogether, our results shed light on the critical role of CBX7 in meningioma malignancy progression and identify the CBX7/USP44/c-MYC/LDHA axis as a promising therapeutic target against meningioma progression.

Mechanism of miR-98-5p in gastric cancer cell proliferation, migration, and invasion through the USP44/CTCFL axis

Objectives

Gastric cancer (GC) is the leading digestive malignancy with high incidence and mortality rate. microRNAs (miRs) play an important role in GC progresssion. This study aimed to investigate the effect of miR-98-5p on proliferation, migration, and invasion of GC cells.

Methods

The expression levels of miR-98-5p, ubiquitin specific peptidase 44 (USP44), and CCCTCbinding factor-like (CTCFL) in GC tissues and cells were identified using reversetranscription quantitative polymerase chain reaction and Western blot assay. The relationship between miR-98-5p expression/USP44 and the clinicopathological features in GC patients was analyzed. GC cell proliferation, invasion, and migration were evaluated by cell counting kit-8 and clone formation assays and Transwell assays. The bindings of miR-98-5p to USP44 and USP44 to CTCFL were examined using dualluciferase assay and co-immunoprecipitation. GC cells were treated with MG132 and the ubiquitination level of CTCFL was examined using ubiquitination assay. Rescue experiments were performed to verify the roles of USP44 and CTCFL in GC cells.

Results

miR-98-5p was downregulated in GC. miR-98-5p overexpression inhibited the proliferation, migration, and invasion of GC cells. miR-98-5p inhibited USP44 expression. USP44 bound to CTCFL and limited ubiquitination degradation of CTCFL. Overexpression of USP44 and CTCFL attenuated the inhibitory effects of miR-98-5p overexpression on GC cell progression.

Conclusion

miR-98-5p overexpression limited USP44-mediated CTCFL deubiquitination, and suppressed CTCFL expression, mitigating GC cell proliferation, migration, and invasion.

The Emerging Role of Deubiquitinases in Radiosensitivity

Radiation therapy is a primary treatment for cancer, but radioresistance remains a significant challenge in improving efficacy and reducing toxicity. Accumulating evidence suggests that deubiquitinases (DUBs) play a crucial role in regulating cell sensitivity to ionizing radiation. Traditional small-molecule DUB inhibitors have demonstrated radiosensitization effects, and novel deubiquitinase-targeting chimeras (DUBTACs) provide a promising strategy for radiosensitizer development by harnessing the ubiquitin-proteasome system. This review highlights the mechanisms by which DUBs regulate radiosensitivity, including DNA damage repair, the cell cycle, cell death, and hypoxia. Progress on DUB inhibitors and DUBTACs is summarized, and their potential radiosensitization effects are discussed. Developing drugs targeting DUBs appears to be a promising alternative approach to overcoming radioresistance, warranting further research into their mechanisms.

GSTM3 enhances radiosensitivity of nasopharyngeal carcinoma by promoting radiation-induced ferroptosis through USP14/FASN axis and GPX4

BACKGROUND

Radiotherapy is a critical treatment modality for nasopharyngeal carcinoma (NPC). However, the mechanisms underlying radiation resistance and tumour recurrence in NPC remain incompletely understood.

METHODS

Oxidised lipids were assessed through targeted metabolomics. Ferroptosis levels were evaluated using cell viability, clonogenic survival, lipid peroxidation, and transmission electron microscopy. We investigated the biological functions of glutathione S-transferase mu 3 (GSTM3) in cell lines and xenograft tumours. Co-immunoprecipitation, mass spectrometry, and immunofluorescence were conducted to explore the molecular mechanisms involving GSTM3. Immunohistochemistry was performed to investigate the clinical characteristics of GSTM3.

RESULTS

Ionising radiation (IR) promoted lipid peroxidation and induced ferroptosis in NPC cells. GSTM3 was upregulated following IR exposure and correlated with IR-induced ferroptosis, enhancing NPC radiosensitivity in vitro and in vivo. Mechanistically, GSTM3 stabilised ubiquitin-specific peptidase 14 (USP14), thereby inhibiting the ubiquitination and subsequent degradation of fatty acid synthase (FASN). Additionally, GSTM3 interacted with glutathione peroxidase 4 (GPX4) and suppressed GPX4 expression. Combining IR treatment with ferroptosis inducers synergistically improved NPC radiosensitivity and suppressed tumour growth. Notably, a decrease in GSTM3 abundance predicted tumour relapse and poor prognosis.

CONCLUSIONS

Our findings elucidate the pivotal role of GSTM3 in IR-induced ferroptosis, offering strategies for the treatment of radiation-resistant or recurrent NPC.

Friend or foe? Reciprocal regulation between E3 ubiquitin ligases and deubiquitinases

Protein ubiquitination is a post-translational modification that entails the covalent attachment of the small protein ubiquitin (Ub), which acts as a signal to direct protein stability, localization, or interactions. The Ub code is written by a family of enzymes called E3 Ub ligases (∼600 members in humans), which can catalyze the transfer of either a single ubiquitin or the formation of a diverse array of polyubiquitin chains. This code can be edited or erased by a different set of enzymes termed deubiquitinases (DUBs; ∼100 members in humans). While enzymes from these distinct families have seemingly opposing activities, certain E3-DUB pairings can also synergize to regulate vital cellular processes like gene expression, autophagy, innate immunity, and cell proliferation. In this review, we highlight recent studies describing Ub ligase-DUB interactions and focus on their relationships.

Transcription factor ATMIN facilitates chemoresistance in nasopharyngeal carcinoma

Despite that the docectaxel-cisplatin-5-fluorouracil (TPF) induction chemotherapy has greatly improved patients' survival and became the first-line treatment for advanced nasopharyngeal carcinoma (NPC), not all patients could benefit from this therapy. The mechanism underlying the TPF chemoresistance remains unclear. Here, by analyzing gene-expression microarray data and survival of patients who received TPF chemotherapy, we identify transcription factor ATMIN as a chemoresistance gene in response to TPF chemotherapy in NPC. Mass spectrometry and Co-IP assays reveal that USP10 deubiquitinates and stabilizes ATMIN protein, resulting the high-ATMIN expression in NPC. Knockdown of ATMIN suppresses the cell proliferation and facilitates the docetaxel-sensitivity of NPC cells both in vitro and in vivo, while overexpression of ATMIN exerts the opposite effect. Mechanistically, ChIP-seq combined with RNA-seq analysis suggests that ATMIN is associated with the cell death signaling and identifies ten candidate target genes of ATMIN. We further confirm that ATMIN transcriptionally activates the downstream target gene LCK and stabilizes it to facilitate cell proliferation and docetaxel resistance. Taken together, our findings broaden the insight into the molecular mechanism of chemoresistance in NPC, and the USP10-ATMIN-LCK axis provides potential therapeutic targets for the management of NPC.

RNA-binding protein NOVA1 promotes acute T-lymphocyte leukemia progression by stabilizing USP44 mRNA

Acute T-lymphocyte leukemia (T-ALL) is a malignant tumor disease. RNA-binding protein neotumor ventral antigen-1 (NOVA1) is highly expressed in bone marrow mononuclear cells of T-ALL patients, while the role of NOVA1 in T-ALL progression remains unknown. The gain- and loss-of-function studies for NOVA1 were performed in Jurkat and CCRF-CEM cells. NOVA1 overexpression promoted cell proliferation and cell cycle progression. NOVA1 knockdown increased the apoptosis rate of T-ALL cells. Ubiquitin-specific protease 44 (USP44), a nuclear protein with deubiquitinase catalytic activity, has been reported to play an oncogene role in human T-cell leukemia. USP44 expression was positively associated with NOVA1, and RNA immunoprecipitation assay verified the binding of NOVA1 to the mRNA of USP44. USP44 knockdown partially abolished NOVA1-induced cell proliferation and inhibition of apoptosis. The in vivo xenograft experiment was performed by injection of T-ALL tumor cells into the tail vein of NOD/SCID mice. The knockdown of NOVA1 had lower tumorigenicity. NOVA1 knockdown alleviated pathological changes in lung and spleen tissues, and increased the overall survival period and the weight of T-ALL mice. Thus, NOVA1 acts as an accelerator in T-ALL, and its function might be achieved by binding to and stabilizing USP44 mRNA.

FLOT2 promotes nasopharyngeal carcinoma progression through suppression of TGF-β pathway via facilitating CD109 expression

In nasopharyngeal carcinoma (NPC), the TGF-β/Smad pathway genes are altered with inactive TGF-β signal, but the mechanisms remain unclear. RNA-sequencing results showed that FLOT2 negatively regulated the TGF-β signaling pathway via up-regulating CD109 expression. qRT-PCR, western blot, ChIP, and dual-luciferase assays were used to identify whether STAT3 is the activating transcription factor of CD109. Co-IP immunofluorescence staining assays were used to demonstrate the connection between FLOT2 and STAT3. In vitro and in vivo experiments were used to detect whether CD109 could rescue the functional changes of NPC cells resulting from FLOT2 alteration. IHC and Spearman correlation coefficients were used to assay the correlation between FLOT2 and CD109 expression in NPC tissues. Our results found that FLOT2 promotes the development of NPC by inhibiting TGF-β signaling pathway via stimulating the expression of CD109 by stabilizing STAT3, which provides a potential therapeutic strategy for NPC treatment.

The E3 ligase NEURL3 suppresses epithelial-mesenchymal transition and metastasis in nasopharyngeal carcinoma by promoting vimentin degradation

BACKGROUND

Metastasis has emerged as the major reason of treatment failure and mortality in patients with nasopharyngeal carcinoma (NPC). Growing evidence links abnormal DNA methylation to the initiation and progression of NPC. However, the precise regulatory mechanism behind these processes remains poorly understood.

METHODS

Bisulfite pyrosequencing, RT-qPCR, western blot, and immunohistochemistry were used to test the methylation and expression level of NEURL3 and its clinical significance. The biological function of NEURL3 was examined both in vitro and in vivo. Mass spectrometry, co-immunohistochemistry, immunofluorescence staining, and ubiquitin assays were performed to explore the regulatory mechanism of NEURL3.

RESULTS

The promoter region of NEURL3, encoding an E3 ubiquitin ligase, was obviously hypermethylated, leading to its downregulated expression in NPC. Clinically, NPC patients with a low NEURL3 expression indicated an unfavorable prognosis and were prone to develop distant metastasis. Overexpression of NEURL3 could suppress the epithelial mesenchymal transition and metastasis of NPC cells in vitro and in vivo. Mechanistically, NEURL3 promoted Vimentin degradation by increasing its K48-linked polyubiquitination at lysine 97. Specifically, the restoration of Vimentin expression could fully reverse the tumor suppressive effect of NEURL3 overexpression in NPC cells.

CONCLUSIONS

Collectively, our study uncovers a novel mechanism by which NEURL3 inhibits NPC metastasis, thereby providing a promising therapeutic target for NPC treatment.

TRIM25 inhibition attenuates inflammation, senescence, and oxidative stress in microvascular endothelial cells induced by hyperglycemia

PURPOSES

This work aimed to assess the possible role of TRIM25 in regulating hyperglycemia-induced inflammation, senescence, and oxidative stress in retinal microvascular endothelial cells, all of which exert critical roles in the pathological process of diabetic retinopathy.

METHODS

The effects of TRIM25 were investigated using streptozotocin-induced diabetic mice, human primary retinal microvascular endothelial cells cultured in high glucose, and adenoviruses for TRIM25 knockdown and overexpression. TRIM25 expression was evaluated by western blot and immunofluorescence staining. Inflammatory cytokines were detected by western blot and quantitative real-time PCR. Cellular senescence level was assessed by detecting senescent marker p21 and senescence-associated-β-galactosidase activity. The oxidative stress state was accessed by detecting reactive oxygen species and mitochondrial superoxide dismutase.

RESULTS

TRIM25 expression is elevated in the endothelial cells of the retinal fibrovascular membrane from diabetic patients compared with that of the macular epiretinal membrane from non-diabetic patients. Moreover, we have also observed a significant increase in TRIM25 expression in diabetic mouse retina and retinal microvascular endothelial cells under hyperglycemia. TRIM25 knockdown suppressed hyperglycemia-induced inflammation, senescence, and oxidative stress in human primary retinal microvascular endothelial cells while TRIM25 overexpression further aggregates those injuries. Further investigation revealed that TRIM25 promoted the inflammatory responses mediated by the TNF-α/NF-κB pathway and TRIM25 knockdown improved cellular senescence by increasing SIRT3. However, TRIM25 knockdown alleviated the oxidative stress independent of both SIRT3 and mitochondrial biogenesis.

CONCLUSION

Our study proposed TRIM25 as a potential therapeutic target for the protection of microvascular function during the progression of diabetic retinopathy.

The Mechanism of Ubiquitination or Deubiquitination Modifications in Regulating Solid Tumor Radiosensitivity

Radiotherapy, a treatment method employing radiation to eradicate tumor cells and subsequently reduce or eliminate tumor masses, is widely applied in the management of numerous patients with tumors. However, its therapeutic effectiveness is somewhat constrained by various drug-resistant factors. Recent studies have highlighted the ubiquitination/deubiquitination system, a reversible molecular modification pathway, for its dual role in influencing tumor behaviors. It can either promote or inhibit tumor progression, impacting tumor proliferation, migration, invasion, and associated therapeutic resistance. Consequently, delving into the potential mechanisms through which ubiquitination and deubiquitination systems modulate the response to radiotherapy in malignant tumors holds paramount significance in augmenting its efficacy. In this paper, we comprehensively examine the strides made in research and the pertinent mechanisms of ubiquitination and deubiquitination systems in governing radiotherapy resistance in tumors. This underscores the potential for developing diverse radiosensitizers targeting distinct mechanisms, with the aim of enhancing the effectiveness of radiotherapy.

Identification of a Prognostic Signature for Ovarian Cancer Based on Ubiquitin-Related Genes Suggesting a Potential Role for FBXO9

BACKGROUND

Ovarian cancer (OV) is associated with high mortality and poses challenges in diagnosis and prognosis prediction. Ubiquitin-related genes (UbRGs) are involved in the initiation and progression of cancers, but have still not been utilized for diagnosis and prognosis of OV.

METHODS

K48-linked ubiquitination in ovarian tissues from our OV and control cohort was assessed using immunohistochemistry. UbRGs, including ubiquitin and ubiquitin-like regulators, were screened based on the TCGA-OV and GTEx database. Univariate Cox regression analysis identified survival-associated UbRGs. A risk model was established using the LASSO regression and multivariate Cox regression analysis. The relationship between UbRGs and immune cell infiltration, tumor mutational burden, drug sensitivity, and immune checkpoint was determined using the CIBERSORT, ESTIMATE, and Maftools algorithms, based on the Genomics of Drug Sensitivity in Cancer and TCGA-OV databases. GEPIA2.0 was used to analyze the correlation between FBXO9/UBD and DNA damage repair-related genes. Finally, FBXO9 and UBD were accessed in tissues or cells using immunohistochemistry, qPCR, and Western blot.

RESULTS

We confirmed the crucial role for ubiquitination in OV as a significant decrease of K48-linked ubiquitination was observed in primary OV lesions. We identified a prognostic signature utilizing two specific UbRGs, FBXO9 and UBD. The risk score obtained from this signature accurately predicted the overall survival of TCGA-OV training dataset and GSE32062 validation dataset. Furthermore, this risk score also showed association with immunocyte infiltration and drug sensitivity, revealing potential mechanisms for ubiquitination mediated OV risk. In addition, FBXO9, but not UBD, was found to be downregulated in OV and positively correlated with DNA damage repair pathways, suggesting FBXO9 as a potential cancer suppressor, likely via facilitating DNA damage repair.

CONCLUSIONS

We identified and validated a signature of UbRGs that accurately predicts the prognosis, offers valuable guidance for optimizing chemotherapy and targeted therapies, and suggests a potential role for FBXO9 in OV.

Enhancing nasopharyngeal carcinoma cell radiosensitivity by suppressing AKT/mTOR via CENP-N knockdown

OBJECTIVE

Investigating the impact of centromere protein N (CENP-N) on radiosensitivity of nasopharyngeal carcinoma (NPC) cells.

METHODS

Using immunohistochemistry and immunofluorescence to detect CENP-N expression in tissues from 35 patients with radiosensitive or radioresistant NPC. Assessing the effect of combined CENP-N knockdown and radiotherapy on various cellular processes by CCK-8, colony formation, flow cytometry, and Western blotting. Establishing a NPC xenograft model. When the tumor volume reached 100 mm3, a irradiation dose of 6 Gy was given, and the effects of the combined treatment were evaluated in vivo using immunofluorescence and Western blotting techniques.

RESULTS

The level of CENP-N was significantly reduced in radiosensitive tissues of NPC (p < 0.05). Knockdown of CENP-N enhanced NPC radiosensitivity, resulting in sensitizing enhancement ratios (SER) of 1.44 (5-8 F) and 1.16 (CNE-2Z). The combined treatment showed significantly higher levels of proliferation suppression, apoptosis, and G2/M phase arrest (p < 0.01) compared to either CENP-N knockdown alone or radiotherapy alone. The combined treatment group showed the highest increase in Bax and γH2AX protein levels, whereas the protein Cyclin D1 exhibited the greatest decrease (p < 0.01). However, the above changes were reversed after treatment with AKT activator SC79. In vivo, the mean volume and weight of tumors in the radiotherapy group were 182 ± 54 mm3 and 0.16 ± 0.03 g. The mean tumor volume and weight in the combined treatment group were 84 ± 42 mm3 and 0.04 ± 0.01 g.

CONCLUSION

Knockdown of CENP-N can enhance NPC radiosensitivity by inhibiting AKT/mTOR.

MAD2 activates IGF1R/PI3K/AKT pathway and promotes cholangiocarcinoma progression by interfering USP44/LIMA1 complex

Spindle assembly checkpoint (SAC) plays an essential part in facilitating normal cell division. However, the clinicopathological and biological significance of mitotic arrest deficient 2 like 1 (MAD2/MAD2L1), a highly conserved member of SAC in cholangiocarcinoma (CCA) remain unclear. We aim to determine the role and mechanism of MAD2 in CCA progression. In the study, we found up-regulated MAD2 facilitated CCA progression and induced lymphatic metastasis dependent on USP44/LIMA1/PI3K/AKT pathway. MAD2 interfered the binding of USP44 to LIMA1 by sequestrating more USP44 in nuclei, causing impaired formation of USP44/LIMA1 complex and enhanced LIMA1 K48 (Lys48)-linked ubiquitination. In therapeutic perspective, the data combined eleven cases of CCA PDTX model showed that high-MAD2 inhibits tumor necrosis and diminishes the inhibition of cell viability after treated with gemcitabine-based regimens. Immunohistochemistry (IHC) analysis of tissue microarray (TMA) for CCA patients revealed that high-MAD2, low-USP44 or low-LIMA1 level are correlated with worse survival for patients. Together, MAD2 activates PI3K/AKT pathway, promotes cancer progression and induces gemcitabine chemo-resistance in CCA. These findings suggest that MAD2 might be an excellent indicator in prognosis analysis and chemotherapy guidance for CCA patients.

DNAJA4 suppresses epithelial-mesenchymal transition and metastasis in nasopharyngeal carcinoma via PSMD2-mediated MYH9 degradation

Emerging evidence indicates that DNA methylation plays an important role in the initiation and progression of nasopharyngeal carcinoma (NPC). DNAJA4 is hypermethylated in NPC, while its role in regulating NPC progression remains unclear. Here, we revealed that the promoter of DNAJA4 was hypermethylated and its expression was downregulated in NPC tissues and cells. Overexpression of DNAJA4 significantly suppressed NPC cell migration, invasion, and EMT in vitro, and markedly inhibited the inguinal lymph node metastasis and lung metastatic colonization in vivo, while it did not affect NPC cell viability and proliferation capability. Mechanistically, DNAJA4 facilitated MYH9 protein degradation via the ubiquitin-proteasome pathway by recruiting PSMD2. Furthermore, the suppressive effects of DNAJA4 on NPC cell migration, invasion, and EMT were reversed by overexpression of MYH9 in NPC cells. Clinically, a low level of DNAJA4 indicated poor prognosis and an increased probability of distant metastasis in NPC patients. Collectively, DNAJA4 serves as a crucial driver for NPC invasion and metastasis, and the DNAJA4-PSMD2-MYH9 axis might contain potential targets for NPC treatments.

A qualitative exploration of fear of progression in patients with nasopharyngeal carcinoma treated with proton and heavy ion therapy

OBJECTIVE

To investigate fear of progression (FOP) in nasopharyngeal carcinoma (NPC) patients treated with proton and heavy ion therapy.

METHODS

Thirty NPC patients were selected for face-to-face semistructured interviews through purposive sampling while using the phenomenological approach in qualitative research. The interviews were transcribed, organized, and analyzed by applying Colaizzi's seven-step analysis.

RESULTS

Seven themes were summarized, namely, illness uncertainty, trapped into insecurity (including four categories: insecurity about the possibility of discrimination, insecurity about the possibility of the inability to tolerate the pain of retreatment, insecurity about the difficulty of retreatment after recurrence, and insecurity of waiting for test results), hopelessness, loss, guilt toward children, enhancing tolerance toward family, and self-emotional comfort.

CONCLUSION

We found that women with children and patients who experienced their first episode underwent significant FOP. Patients at the postgraduate level and above were more inclined to feel loss. The finding that respondents expressed is intense FOP while waiting for test results, which provides a reference for the analysis of the trajectory of FOP. Health care professions should be cognitively aware the importance of eliminating patients' uncertainty and insecurity about disease to enhance their positive experience in coping with cancer.

USP32 deubiquitinase: cellular functions, regulatory mechanisms, and potential as a cancer therapy target

An essential protein regulatory system in cells is the ubiquitin-proteasome pathway. The substrate is modified by the ubiquitin ligase system (E1-E2-E3) in this pathway, which is a dynamic protein bidirectional modification regulation system. Deubiquitinating enzymes (DUBs) are tasked with specifically hydrolyzing ubiquitin molecules from ubiquitin-linked proteins or precursor proteins and inversely regulating protein degradation, which in turn affects protein function. The ubiquitin-specific peptidase 32 (USP32) protein level is associated with cell cycle progression, proliferation, migration, invasion, and other cellular biological processes. It is an important member of the ubiquitin-specific protease family. It is thought that USP32, a unique enzyme that controls the ubiquitin process, is closely linked to the onset and progression of many cancers, including small cell lung cancer, gastric cancer, breast cancer, epithelial ovarian cancer, glioblastoma, gastrointestinal stromal tumor, acute myeloid leukemia, and pancreatic adenocarcinoma. In this review, we focus on the multiple mechanisms of USP32 in various tumor types and show that USP32 controls the stability of many distinct proteins. Therefore, USP32 is a key and promising therapeutic target for tumor therapy, which could provide important new insights and avenues for antitumor drug development. The therapeutic importance of USP32 in cancer treatment remains to be further proven. In conclusion, there are many options for the future direction of USP32 research.

HepaClear, a blood-based panel combining novel methylated CpG sites and protein markers, for the detection of early-stage hepatocellular carcinoma

BACKGROUND

Early screening and detection of hepatocellular carcinoma (HCC) can efficiently improve patient prognosis. We aimed to identify a series of hypermethylated DNA markers and develop a blood-based HCC diagnosis panel containing DNA methylation sites and protein markers with improved sensitivity for early-stage HCC detection.

RESULTS

Overall, 850K methylation arrays were performed using paired tissue DNA samples from 60 HCC patients. Ten candidate hypermethylated CpG sites were selected for further evaluation by quantitative methylation-specific PCR with 60 pairs of tissue samples. Six methylated CpG sites, along with α-fetoprotein (AFP) and des-gamma-carboxyprothrombin (DCP), were assayed in 150 plasma samples. Finally, an HCC diagnosis panel, named HepaClear, was developed in a cohort consisting of 296 plasma samples and validated in an independent cohort consisting of 198 plasma samples. The HepaClear panel, containing 3 hypermethylated CpG sites (cg14263942, cg12701184, and cg14570307) and 2 protein markers (AFP and DCP), yielded a sensitivity of 82.6% and a specificity of 96.2% in the training set and a sensitivity of 84.7% and a specificity of 92.0% in the validation set. The HepaClear panel had higher sensitivity (72.0%) for early-stage HCC than AFP (≥ 20 ng/mL, 48.0%) and DCP (≥ 40 mAU/mL, 62.0%) and detected 67.5% of AFP-negative HCC patients (AFP ≤ 20 ng/mL).

CONCLUSIONS

We developed a multimarker HCC detection panel (HepaClear) that shows high sensitivity for early-stage HCC. The HepaClear panel exhibits high potential for HCC screening and diagnosis from an at-risk population.

m6A-enriched lncRNA LINC00839 promotes tumor progression by enhancing TAF15-mediated transcription of amine oxidase AOC1 in nasopharyngeal carcinoma

Dysregulation of long non-coding RNAs (lncRNAs) contributes to tumorigenesis by modulating specific cancer-related pathways, but the roles of m6A-enriched lncRNAs and underlying mechanisms remain elusive in nasopharyngeal carcinoma (NPC). Here, we reanalyzed the previous genome-wide analysis of lncRNA profiles in 18 pairs of NPC and normal tissues, as well as in 10 paired samples from NPC with or without posttreatment metastases. We discerned that an oncogenic m6A-enriched lncRNA, LINC00839, which was substantially upregulated in NPC and correlated with poor clinical prognosis, promoted NPC growth and metastasis both in vitro and in vivo. Mechanistically, by using RNA pulldown assay combined with mass spectrometry, we found that LINC00839 interacted directly with the transcription factor, TATA-box binding protein associated factor (TAF15). Besides, ChIP and dual-luciferase report assays demonstrated that LINC00839 coordinated the recruitment of TAF15 to the promoter region of amine oxidase copper-containing 1 (AOC1), which encodes a secreted glycoprotein playing vital roles in various cancers, thereby activating AOC1 transcription in trans. In this study, potential effects of AOC1 in NPC progression were first proposed. Moreover, ectopic expression of AOC1 partially rescued the inhibitory effect of downregulation of LINC00839 in NPC. Furthermore, we showed that silencing vir-like m6A methyltransferase-associated (VIRMA) and insulin-like growth factor 2 mRNA-binding proteins 1 (IGF2BP1) attenuated the expression level and RNA stability of LINC00839 in an m6A-dependent manner. Taken together, our study unveils a novel oncogenic VIRMA/IGF2BP1-LINC00839-TAF15-AOC1 axis, and highlights the significance and prognostic value of LINC00839 expression in NPC carcinogenesis.

Integrated network findings reveal ubiquitin-specific protease 44 overexpression suppresses tumorigenicity of liver cancer

Hepatocellular carcinoma (HCC) is the sixth most common cancer and third leading cause of cancer-related deaths worldwide. HCC is a multistep disease marked by various signaling alterations. A better understanding of the new molecular drivers of HCC could therefore provide an opportunity to develop effective diagnostic and therapeutic targets. Ubiquitin-specific protease 44 (USP44), a member of the cysteine protease family, has been reported to play a role in many cancer types. However, its contribution to HCC development remains unknown. In the present study, we observed suppression of USP44 expression in HCC tissue. Clinicopathologic analysis further showed that low USP44 expression correlated with poorer survival and a later tumor stage in HCC, suggesting that USP44 could be a predictor of poor prognosis in patients with HCC. Gain-of-function analysis in vitro demonstrated the importance of USP44 in HCC cell growth and G₀/G₁ cell cycle arrest. To investigate the downstream targets of USP44 and the molecular mechanisms underlying its regulation of cell proliferation in HCC, we conducted a comparative transcriptomic analysis and identified a cluster of proliferation-related genes, including CCND2, CCNG2, and SMC3. Ingenuity Pathway Analysis further delineated the gene networks controlled by USP44 through the regulation of membrane proteins and receptors, enzymes, transcriptional factors, and cyclins involved in the control of cell proliferation, metastasis, and apoptosis in HCC. To summarize, our results highlight, for the first time, the tumor-suppression role of USP44 in HCC and suggest a new prognostic biomarker in this disease.

Radiation induces IRAK1 expression to promote radioresistance by suppressing autophagic cell death via decreasing the ubiquitination of PRDX1 in glioma cells

Radiotherapy is the standard adjuvant treatment for glioma patients; however, the efficacy is limited by radioresistance. The function of Interleukin-1 receptor associated kinase 1 (IRAK1) in tumorigenesis and radioresistance remains to be elucidated. IRAK1 expression and its correlation with prognosis were analyzed in glioma tissues. We found that glioma patients with overexpressed IRAK1 show a poor prognosis. Notably, ionizing radiation (IR) remarkably induces IRAK1 expression, which was decreased by STING antagonist H-151 treatment. JASPAR prediction, ChIP assays, and dual luciferase reporter assays indicated that transcription factor FOXA2, suppressed by STING inhibition, directly binds to the IRAK1 promoter region and activates its transcription. IRAK1 knockdown inhibits malignancy and enhances the radiosensitivity of glioma in vitro and in vivo. To explore the potential IRAK1 interacting targets mediating the radioresistance of glioma cells, IP/Co-IP, LC-MS/MS, GST pull-down, and ubiquitination analyses were conducted. Mechanistically, IRAK1 bound to PRDX1, a major member of antioxidant enzymes, and further prevents ubiquitination and degradation of PRDX1 mediated by E3 ubiquitin ligase HECTD3; Both the DOC and HECT domains of HECTD3 directly interacted with PRDX1 protein. Overexpression of PRDX1 reverses the radiotherapy sensitization effect of IRAK1 depletion by diminishing autophagic cell death. These results suggest the IRAK1-PRDX1 axis provides a potential therapeutic target for glioma patients.

TIPE3 represses head and neck squamous cell carcinoma progression via triggering PGAM5 mediated mitochondria dysfunction

Mitochondria are essential organelles in balancing oxidative stress and cell death during cancer cell proliferation. Rapid tumor growth induces tremendous stress on mitochondria. The mammalian tumor necrosis factor-α-induced protein 8-likes (TIPEs) family plays critical roles in balancing cancer cell death and survival. Yet, the roles of TIPEs in HNSCC tumorigenesis and mitochondria stress maintenance is unclear. Based on an integrative analysis of public HNSCC datasets, we identified that the downregulation of TIPE3 via its promoter hypermethylation modification is the major event of TIPEs alterations during HNSCC tumorigenesis. Low expression levels of TIPE3 were correlated with high malignancy and poor clinical outcomes of HNSCC patients. Restoring TIPE3 represses HNSCC proliferation, migration, and invasion in vitro and in vivo, while silencing TIPE3 acted on an opposite way. Mechanistically, TIPE3 band to the PGAM5 and electron transport chain (ETC) complex. Restoring TIPE3 promoted PGAM5 recruiting BAX and dephosphorylating p-DRP1(Ser637), which triggered mitochondrial outer membrane permeabilization and fragmentation. Ultimately, TIPE3 induced ETC damage and oxygen consumption rate decrease, ROS accumulation, mitochondrial membrane potential depolarization, and cell apoptosis. Collectively, our work reveals that TIPE3 plays critical role in maintaining mitochondrial stress and cancer cell progression in HNSCC, which might be a potential therapeutic target for HNSCC patients.

LINC00173 facilitates tumor progression by stimulating RAB1B-mediated PA2G4 and SDF4 secretion in nasopharyngeal carcinoma

An increasing number of studies have found that long non-coding RNA (lncRNA) play important roles in driving the progression of nasopharyngeal carcinoma (NPC). Our microarray screening revealed that expression of the lncRNA long intergenic non-protein coding RNA 173 (LINC00173) was upregulated in NPC. However, its role and mechanism in NPC have not yet been elucidated. In this study, we demonstrate that high LINC00173 expression indicated a poor prognosis in NPC patients. Knockdown of LINC00173 significantly inhibited NPC cell proliferation, migration and invasion in vitro. Mechanistically, LINC00173 interacted and colocalized with Ras-related protein Rab-1B (RAB1B) in the cytoplasm, but the modulation of LINC00173 expression did not affect the expression of RAB1B at either the mRNA or protein levels. Instead, relying on the stimulation of RAB1B, LINC00173 could facilitate the extracellular secretion of proliferation-associated 2G4 (PA2G4) and stromal cell-derived factor 4 (SDF4; also known as 45-kDa calcium-binding protein) proteins, and knockdown of these proteins could reverse the NPC aggressive phenotype induced by LINC00173 overexpression. Moreover, in vivo LINC00173-knockdown models exhibited a marked slowdown in tumor growth and a significant reduction in lymph node and lung metastases. In summary, LINC00173 serves as a crucial driver for NPC progression, and the LINC00173-RAB1B-PA2G4/SDF4 axis might provide a potential therapeutic target for NPC patients.

TRIM21 inhibits irradiation-induced mitochondrial DNA release and impairs antitumour immunity in nasopharyngeal carcinoma tumour models

Although radiotherapy can promote antitumour immunity, the mechanisms underlying this phenomenon remain unclear. Here, we demonstrate that the expression of the E3 ubiquitin ligase, tumour cell-intrinsic tripartite motif-containing 21 (TRIM21) in tumours, is inversely associated with the response to radiation and CD8⁺ T cell-mediated antitumour immunity in nasopharyngeal carcinoma (NPC). Knockout of TRIM21 modulates the cGAS/STING cytosolic DNA sensing pathway, potentiates the antigen-presenting capacity of NPC cells, and activates cytotoxic T cell-mediated antitumour immunity in response to radiation. Mechanistically, TRIM21 promotes the degradation of the mitochondrial voltage-dependent anion-selective channel protein 2 (VDAC2) via K48-linked ubiquitination, which inhibits pore formation by VDAC2 oligomers for mitochondrial DNA (mtDNA) release, thereby inhibiting type-I interferon responses following radiation exposure. In patients with NPC, high TRIM21 expression was associated with poor prognosis and early tumour relapse after radiotherapy. Our findings reveal a critical role of TRIM21 in radiation-induced antitumour immunity, providing potential targets for improving the efficacy of radiotherapy in patients with NPC.

High proportion of circulating CD8 + CD28- senescent T cells is an independent predictor of distant metastasis in nasopharyngeal canrcinoma after radiotherapy

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a kind of epithelial carcinoma that is common in East and Southeast Asia. Distant metastasis after radiotherapy remains the main cause of treatment failure and preradiotherapy immune system function can influence prognosis. Our study aimed to identify immune-related prognostic factors for NPC after radiotherapy and establish a prognostic model to predict progression-free survival (PFS) and distant metastasis-free survival (DMFS).

METHODS

We enrolled NPC patients and divided them into training and validation cohorts with follow-up. We collected clinical information and investigated immune cells, EBV DNA and cytokines in the peripheral blood of NPC patients before radiotherapy and EBV DNA after radiotherapy. Among these immune cells, we included CD8⁺CD28^- T cells, which are a unique T-cell immunosenescent subset that increases in human peripheral blood with increasing age and declining immune function. Based on the detection results and clinical information, we utilized Cox regression and least absolute shrinkage and selection operator (LASSO) regression to screen the PFS and DMFS prognostic factors and build nomograms to predict the PFS and DMFS of NPC. We also verified the results in the validation set.

RESULTS

Three factors associated with PFS were selected: proportion of CD8⁺CD28^- T cells posttreatment EBV and N stage. Three factors associated with DMFS were screened: proportion of CD8⁺CD28^- T cells, posttreatment EBV and N stage. CD8⁺CD28^- T cells are correlated with systemic inflammation and posttreatment immunosuppression. The C-indexes were 0.735 and 0.745 in the training and validation cohorts for predicting PFS. For DMFS, the C-indexes were 0.793 and 0.774 in the training and validation cohorts.

CONCLUSIONS

The pretreatment proportion of CD8⁺CD28^- T cells is a candidate prognostic biomarker for NPC after radiotherapy. The constructed nomogram models based on CD8⁺CD28^- T cells have good predictive value.

Risk model based on minichromosome maintenance 2 using objective assessment for predicting survival of neuroblastoma

Aberrant minichromosome maintenance (MCM) expression is associated with tumorigenesis. Here, we performed immunohistochemistry integrated with digital pathology to identify MCM2/5/6 expression in 130 neuroblastoma patients. A risk score was established using least absolute shrinkage and selection operator that predicts outcomes according to MCM2 expression, age, and the International Neuroblastoma Staging System in the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset (n = 150), where the patients with high risk had significantly worse prognosis that was validated in a hospital-based cohort (n = 130). After multivariable adjustment, the risk model remained an independent factor for survival in the TARGET cohort (overall survival [OS]: hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.4-4.0; event-free survival [EFS]: HR 1.8, 95% CI 1.1-3.1) and for OS in the validation cohort (HR 8.3, 95% CI 1.6-44.5). The ESTIMATE indicates that the risk model is negatively correlated with low ESTIMATE and stromal scores. These findings show the additive nature of this score, fostering its future implementation with new prognostic variables.

Radiosensitivity in Non-Small-Cell Lung Cancer by MMP10 through the DNA Damage Repair Pathway

NSCLC (non-small-cell lung cancer) is an aggressive form of lung cancer and accompanies high morbidity and mortality. This study investigated the function and associated mechanism of MMP10 during radiotherapy of NSCLC. MMP10 expression in patients and their overall survival rate were assessed through GEPIA. Protein expression was tested by western blotting. Radioresistance was detected in vitro by apoptosis and clonogenic assay. The extent of DNA damage and repair was revealed by the comet test and γH2AX foci test. High MMP10 levels in specimens of lung adenocarcinoma were related to poor patient outcomes. Clonogenic and apoptosis assays revealed that MMP10 knockdown in A549 cells initiated radiosensitization. Furthermore, MMP10 siRNA increased damage to the DNA in NSCLC cells, while MMP10 was observed to participate in DNA damage repair post-ionizing radiation. Thus, after irradiation, MMP10 plays an essential role in NSCLC through the repair pathway of DNA damage; regulating MMP10 for NSCLC radiosensitivity might have potential treatment implications in radiotherapy of NSCLC.

Pharmacological impact of microRNAs in head and neck squamous cell carcinoma: Prevailing insights on molecular pathways, diagnosis, and nanomedicine treatment

Head and neck squamous cell carcinoma is a disease that most commonly produce tumours from the lining of the epithelial cells of the lips, larynx, nasopharynx, mouth, or oro-pharynx. It is one of the most deadly forms of cancer. About one to two percent of all neo-plasm-related deaths are attributed to head and neck squamous cell carcinoma, which is responsible for about six percent of all cancers. MicroRNAs play a critical role in cell proliferation, differentiation, tumorigenesis, stress response, triggering apoptosis, and other physiological process. MicroRNAs regulate gene expression and provide new diagnostic, prognostic, and therapeutic options for head and neck squamous cell carcinoma. In this work, the role of molecular signaling pathways related to head and neck squamous cell carcinoma is emphasized. We also provide an overview of MicroRNA downregulation and overexpression and its role as a diagnostic and prognostic marker in head and neck squamous cell carcinoma. In recent years, MicroRNA nano-based therapies for head and neck squamous cell carcinoma have been explored. In addition, nanotechnology-based alternatives have been discussed as a promising strategy in exploring therapeutic paradigms aimed at improving the efficacy of conventional cytotoxic chemotherapeutic agents against head and neck squamous cell carcinoma and attenuating their cytotoxicity. This article also provides information on ongoing and recently completed clinical trials for therapies based on nanotechnology.

miR-4443 promotes radiation resistance of esophageal squamous cell carcinoma via targeting PTPRJ

BACKGROUND

Radiotherapy is one of the main treatments for esophageal squamous cell carcinoma (ESCC), but its efficacy is limited by radioresistance. MicroRNAs play a crucial role in posttranscriptional regulation, which is linked to the cancer response to radiation.

METHODS

We successfully established a radioresistant cell line model by using fractionated irradiation. qRT-PCR was adopted to detect the expression of miR-4443 in human normal esophageal cell lines, tumor cells, and radioresistant cells. Next, CCK-8, colony formation, apoptosis, and cell cycle assays were used to assess the biological effect of miR-4443. Weighted gene coexpression network analysis (WGCNA) was performed to identify potential radiosensitivity-related genes. Additionally, we predicted the probable targets of the miRNA using bioinformatic methods and confirmed them using Western blot.

RESULTS

miR-4443 was significantly upregulated in radioresistant ESCC cells. Enhancement of miR-4443 further decreased the radiosensitivity of ESCC cells, while inhibition of miR-4443 increased the radiosensitivity of ESCC cells. Notably, miR-4443 modulated radiosensitivity by influencing DNA damage repair, apoptosis, and G2 cycle arrest. By using WGCNA and experimental validation, we identified PTPRJ as a key target for miRNA-4443 to regulate radiosensitivity. The effects of miR-4443 overexpression or inhibition could be reversed by increasing or decreasing PTPRJ expression.

CONCLUSION

In this study, miR-4443 is found to promote radiotherapy resistance in ESCC cells by regulating PTPRJ expression, which provides a new perspective and clue to alleviate radioresistance.

N6 -Methyladenosine-Modified CBX1 Regulates Nasopharyngeal Carcinoma Progression Through Heterochromatin Formation and STAT1 Activation

Epitranscriptomic remodeling such as N⁶ -methyladenosine (m⁶ A) modification plays a critical role in tumor development. However, little is known about the underlying mechanisms connecting m⁶ A modification and nasopharyngeal carcinoma (NPC) progression. Here, CBX1 is identified, a histone methylation regulator, to be significantly upregulated with m⁶ A hypomethylation in metastatic NPC tissues. The m⁶ A-modified CBX1 mRNA transcript is recognized and destabilized by the m⁶ A reader YTHDF3. Furthermore, it is revealed that CBX1 promotes NPC cell migration, invasion, and proliferation through transcriptional repression of MAP7 via H3K9me3-mediated heterochromatin formation. In addition to its oncogenic effect, CBX1 can facilitate immune evasion through IFN-γ-STAT1 signaling-mediated PD-L1 upregulation. Clinically, CBX1 serves as an independent predictor for unfavorable prognosis in NPC patients. The results reveal a crosstalk between epitranscriptomic and epigenetic regulation in NPC progression, and shed light on the functions of CBX1 in tumorigenesis and immunomodulation, which may provide an appealing therapeutic target in NPC.

Insight into the physiological and pathological roles of USP44, a potential tumor target (Review)

Ubiquitin-specific peptidase 44 (USP44) is a member of the ubiquitin-specific proteases (USPs) family and its functions in various biological processes have been gradually elucidated in recent years. USP44 targets multiple downstream factors and regulates multiple mechanisms through its deubiquitination activity. Ubiquitination is, in essence, a process in which a single ubiquitin molecule or a multiubiquitin chain binds to a substrate protein to form an isopeptide bond. Deubiquitination is the catalyzing of the isopeptide bonds between ubiquitin and substrate proteins through deubiquitylating enzymes. These two processes serve an important role in the regulation of the expression, conformation, localization and function of substrate proteins by regulating their binding to ubiquitin. Based on existing research, this paper summarized the current state of knowledge about USP44. The physiological roles of USP44 in various cellular events and its pathophysiological roles in different cancer types are evaluated and the therapeutic potential of USP44 for cancer treatment is evaluated.

A lncRNA signature associated with tumor immune heterogeneity predicts distant metastasis in locoregionally advanced nasopharyngeal carcinoma

Increasing evidence has revealed the roles of long noncoding RNAs (lncRNAs) as tumor biomarkers. Here, we introduce an immune-associated nine-lncRNA signature for predicting distant metastasis in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). The nine lncRNAs are identified through microarray profiling, followed by RT–qPCR validation and selection using a machine learning method in the training cohort (n = 177). This nine-lncRNA signature classifies patients into high and low risk groups, which have significantly different distant metastasis-free survival. Validations in the Guangzhou internal (n = 177) and Guilin external (n = 150) cohorts yield similar results, confirming that the signature is an independent risk factor for distant metastasis and outperforms anatomy-based metrics in identifying patients with high metastatic risk. Integrative analyses show that this nine-lncRNA signature correlates with immune activity and lymphocyte infiltration, which is validated by digital pathology. Our results suggest that the immune-associated nine-lncRNA signature can serve as a promising biomarker for metastasis prediction in LA-NPC.

Long noncoding RNAs (lncRNAs) can be used for the development of prognostic signatures to predict tumour metastasis. Here the authors identify an immune-associated nine-lncRNA signature for predicting metastasis in a multicentre cohort of locoregionally advanced nasopharyngeal cancer patients.