TRAIP modulates the IGFBP3/AKT pathway to enhance the invasion and proliferation of osteosarcoma by promoting KANK1 degradation

ULK2 suppresses ovarian cancer cell migration and invasion by elevating IGFBP3

Background

Ovarian cancer is an aggressive malignancy with high mortality known for its considerable metastatic potential. This study aimed to explore the expression and functional role of Unc-51 like autophagy activating kinase 2 (ULK2) in the progression of ovarian cancer.

Methods

ULK2 expression patterns in ovarian cancer tissues as well as benign tumor control samples obtained from our institution were evaluated using immunohistochemistry. Cell counting kit 8 and Transwell assays were applied to assess the effects of ULK2 overexpression on cell proliferation, migration and invasion, respectively. RNA sequencing was performed to explore potential mechanisms of action of ULK2 beyond its classical autophagy modulation.

Results

Our experiments showed significant downregulation of ULK2 in ovarian cancer tissues. Importantly, low expression of ULK2 was markedly correlated with decreased overall survival. In vitro functional studies further demonstrated that overexpression of ULK2 significantly suppressed tumor cell proliferation, migration, and invasion. RNA sequencing analysis revealed a potential regulatory role of ULK2 in the insulin signaling pathway through upregulation of insulin-like growth factor binding protein-3 (IGFBP3) in ovarian cancer cells.

Conclusions

In summary, the collective data indicated that ULK2 acted as a tumor suppressor in ovarian cancer by upregulating the expression of IGFBP3. Our study underscores the potential utility of ULK2 as a valuable prognostic marker for ovarian cancer.

TRAIP suppresses bladder cancer progression by catalyzing K48-linked polyubiquitination of MYC

TRAF-interacting protein (TRAIP), an E3 ligase containing a RING domain, has emerged as a significant contributor to maintaining genome integrity and is closely associated with cancer. Our study reveals that TRAIP shows reduced expression in bladder cancer (BLCA), which correlates with an unfavorable prognosis. In vitro and in vivo, TRAIP inhibits proliferation and migration of BLCA cells. MYC has been identified as a novel target for TRAIP, wherein direct interaction promotes K48-linked polyubiquitination at neighboring K428 and K430 residues, ultimately resulting in proteasome-dependent degradation and downregulation of MYC transcriptional activity. This mechanism effectively impedes the progression of BLCA. Restoring MYC expression reverses suppressed proliferation and migration of BLCA cells induced by TRAIP. Moreover, our results suggest that MYC may bind to the transcriptional start region of TRAIP, thereby exerting regulatory control over TRAIP transcription. Consequently, this interaction establishes a negative feedback loop that regulates MYC expression, preventing excessive levels. Taken together, this study reveals a mechanism that TRAIP inhibits proliferation and migration of BLCA by promoting ubiquitin-mediated degradation of MYC.

Implications of ubiquitination and the maintenance of replication fork stability in cancer therapy

DNA replication forks are subject to intricate surveillance and strict regulation by sophisticated cellular machinery. Such close regulation is necessary to ensure the accurate duplication of genetic information and to tackle the diverse endogenous and exogenous stresses that impede this process. Stalled replication forks are vulnerable to collapse, which is a major cause of genomic instability and carcinogenesis. Replication stress responses, which are organized via a series of coordinated molecular events, stabilize stalled replication forks and carry out fork reversal and restoration. DNA damage tolerance and repair pathways such as homologous recombination and Fanconi anemia also contribute to replication fork stabilization. The signaling network that mediates the transduction and interplay of these pathways is regulated by a series of post-translational modifications, including ubiquitination, which affects the activity, stability, and interactome of substrates. In particular, the ubiquitination of replication protein A and proliferating cell nuclear antigen at stalled replication forks promotes the recruitment of downstream regulators. In this review, we describe the ubiquitination-mediated signaling cascades that regulate replication fork progression and stabilization. In addition, we discuss the targeting of replication fork stability and ubiquitination system components as a potential therapeutic approach for the treatment of cancer.

TRAIP serves as a potential prognostic biomarker and correlates with immune infiltrates in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is one of the major types of lung cancer with high morbidity and mortality. The TRAF-interacting protein (TRAIP) is a ring-type E3 ubiquitin ligase which has been recently identified to play pivotal roles in various cancers. However, the expression and function of TRAIP in LUAD remain elusive.

METHODS

In this study, we used bioinformatic tools as well as molecular experiments to explore the exact role of TRAIP and the underlying mechanism.

RESULTS

Data mining across the UALCAN, GEPIA and GTEx, GEO and HPA databases revealed that TRAIP was significantly overexpressed in LUAD tissues than that in adjacent normal tissues. Kaplan-Meier curve showed that high TRAIP expression was associated with poor overall survival (OS) and relapse-free survival (RFS). Univariate and multivariate cox regression analysis revealed that TRAIP was an independent risk factor in LUAD. And the TRAIP-based nomogram further supported the prognostic role of TRAIP in LUAD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that TRAIP-associated genes were mainly involved in DNA replication, cell cycle and other processes. The immune infiltration analysis indicated that TRAIP expression was tightly correlated with the infiltration of diverse immune cell types, including B cell, CD8 + T cell, neutrophil and dendritic cell. Moreover, TRAIP expression was observed to be significantly associated with tumor infiltrating lymphocytes (TILs) and immune checkpoint molecules. In vitro experiments further confirmed knockdown of TRAIP inhibited cell migration and invasion, as well as decreasing chemokine production and inhibiting M2-like macrophage recruitment. Lastly, CMap analysis identified 10 small molecule compounds that may target TRAIP, providing potential therapies for LUAD.

CONCLUSIONS

Collectively, our study found that TRAIP is an oncogenic gene in LUAD, which may be a potential prognostic biomarker and promising therapeutic target for LUAD.

Construction of a prognostic model based on eight ubiquitination-related genes via machine learning and potential therapeutics analysis for cervical cancer

Introduction: Ubiquitination is involved in many biological processes and its predictive value for prognosis in cervical cancer is still unclear.

Methods: To further explore the predictive value of the ubiquitination-related genes we obtained URGs from the Ubiquitin and Ubiquitin-like Conjugation Database, analyzed datasets from The Cancer Genome Atlas and Gene Expression Omnibus databases, and then selected differentially expressed ubiquitination-related genes between normal and cancer tissues. Then, DURGs significantly associated with overall survival were selected through univariate Cox regression. Machine learning was further used to select the DURGs. Then, we constructed and validated a reliable prognostic gene signature by multivariate analysis. In addition, we predicted the substrate proteins of the signature genes and did a functional analysis to further understand the molecular biology mechanisms. The study provided new guidelines for evaluating cervical cancer prognosis and also suggested new directions for drug development.

Results: By analyzing 1,390 URGs in GEO and TCGA databases, we obtained 175 DURGs. Our results showed 19 DURGs were related to prognosis. Finally, eight DURGs were identified via machine learning to construct the first ubiquitination prognostic gene signature. Patients were stratified into high-risk and low-risk groups and the prognosis was worse in the high-risk group. In addition, these gene protein levels were mostly consistent with their transcript level. According to the functional analysis of substrate proteins, the signature genes may be involved in cancer development through the transcription factor activity and the classical P53 pathway ubiquitination-related signaling pathways. Additionally, 71 small molecular compounds were identified as potential drugs.

Conclusion: We systematically studied the influence of ubiquitination-related genes on prognosis in cervical cancer, established a prognostic model through a machine learning algorithm, and verified it. Also, our study provides a new treatment strategy for cervical cancer.

Managing the immune microenvironment of osteosarcoma: the outlook for osteosarcoma treatment

Osteosarcoma, with poor survival after metastasis, is considered the most common primary bone cancer in adolescents. Notwithstanding the efforts of researchers, its five-year survival rate has only shown limited improvement, suggesting that existing therapeutic strategies are insufficient to meet clinical needs. Notably, immunotherapy has shown certain advantages over traditional tumor treatments in inhibiting metastasis. Therefore, managing the immune microenvironment in osteosarcoma can provide novel and valuable insight into the multifaceted mechanisms underlying the heterogeneity and progression of the disease. Additionally, given the advances in nanomedicine, there exist many advanced nanoplatforms for enhanced osteosarcoma immunotherapy with satisfactory physiochemical characteristics. Here, we review the classification, characteristics, and functions of the key components of the immune microenvironment in osteosarcoma. This review also emphasizes the application, progress, and prospects of osteosarcoma immunotherapy and discusses several nanomedicine-based options to enhance the efficiency of osteosarcoma treatment. Furthermore, we examine the disadvantages of standard treatments and present future perspectives for osteosarcoma immunotherapy.

Silencing TRAIP suppresses cell proliferation and migration/invasion of triple negative breast cancer via RB-E2F signaling and EMT

TRAIP, as a 53 kDa E3 ubiquitin protein ligase, is involved in various cellular processes and closely related to the occurrence and development of tumors. At present, few studies on the relationship between TRAIP and triple negative breast cancer (TNBC) were reported. Bioinformatic analysis and Western blot, immunohistochemistry (IHC), CCK-8, colony formation, flow cytometry, wound healing, Transwell, and dual-luciferase reporter assays were performed, and xenograft mouse models were established to explore the role of TRAIP in TNBC. This study showed that the expression of TRAIP protein was upregulated in TNBC tissues and cell lines. Silencing of TRAIP significantly inhibited the proliferation, migration, and invasion of TNBC cells, whereas opposite results were observed in the TRAIP overexpression. In addition, TRAIP regulated cell proliferation, migration, and invasion through RB-E2F signaling and epithelial mesenchymal transformation (EMT). MiR-590-3p directly targeted the TRAIP 3'-UTR, and its expression were lower in TNBC tissues. Its mimic significantly downregulated the expression of TRAIP and subsequently suppressed cell proliferation, migration, and invasion. Rescue experiments indicated that TRAIP silencing reversed the promotion of miR-590-3p inhibitor on cell proliferation, migration, and invasion. TRAIP overexpression could also reverse the inhibition of miR-590-3p mimic on tumorigenesis. Finally, TRAIP knockdown significantly inhibited tumor growth and metastasis in animal experiments. In conclusion, TRAIP is an oncogene that influences the proliferation, migration, and invasion of TNBC cells through RB-E2F signaling and EMT. Therefore, TRAIP may be a potential therapeutic target for TNBC.

Cellular functions and molecular mechanisms of ubiquitination in osteosarcoma

Although some advances have been made in the treatment of osteosarcoma in recent years, surgical resection remains the mainstream treatment. Initial and early diagnosis of osteosarcoma could be very difficult to achieve due to the insufficient sensitivity for the means of examination. The distal metastasis of osteosarcoma also predicts the poor prognosis of osteosarcoma. In order to solve this series of problems, people begin to discover a new method of diagnosing and treating osteosarcoma. Ubiquitination, as an emerging posttranslational modification, has been shown to be closely related to osteosarcoma in studies over the past decades. In general, this review describes the cellular functions and molecular mechanisms of ubiquitination during the development of osteosarcoma.

Targeted Delivery of PD-L1-Derived Phosphorylation-Mimicking Peptides by Engineered Biomimetic Nanovesicles to Enhance Osteosarcoma Treatment

Osteosarcoma is a rare malignant bone-originating tumor that usually occurs in young people. Programmed cell death 1 ligand 1 (PD-L1), an immune checkpoint protein, is highly expressed in osteosarcoma tissues. Several recent studies have indicated that the tumor-related role of PD-L1 in tumors, especially non-plasma membrane (NPM)-localized PD-L1, is not limited to immune regulation in osteosarcoma. Here, mass spectrometry analysis is combined with RNA-seq examination to identify the intracellular binding partners of PD-L1 and elucidate the underlying mechanism of its action. It is found that the NPM-localized PD-L1 interacted with Insulin-like growth factor binding protein-3 (IGFBP3) to promote osteosarcoma tumor growth by activating mTOR signaling. This interaction is enforced after phosphoglyceratekinase1 (PGK1)-mediated PD-L1 phosphorylation. Based on these findings, a phosphorylation-mimicking peptide is designed from PD-L1 and it is encapsulated with a Cyclic RGD (cRGD)-modified red blood cell membrane (RBCM) vesicle (Peptide@cRGD-M). The Peptide@cRGD-M precisely delivers the PD-L1-derived phosphorylation-mimicking peptide into osteosarcoma lesions and significantly promotes its therapeutic effect on the tumor. Therefore, this investigation not only highlights the function of NPM-localized PD-L1, but also uses an engineering approach to synthesize a small molecular peptide capable of inhibiting osteosarcoma growth.

Identification of Ubiquitin-Related Gene-Pair Signatures for Predicting Tumor Microenvironment Infiltration and Drug Sensitivity of Lung Adenocarcinoma

Simple Summary

Lung adenocarcinoma (LUAD) has a high mortality and incidence rate. The therapeutic efficacy of LUAD varies with the individual heterogeneity of the tumor microenvironment (TME). It is necessary to explore more biomarkers and targets to improve the prognosis of patients. Ubiquitination pathways are involved in the biological process of regulating the anti-tumor immunity of immune cells and immunosuppression of tumor cells in the TME of patients. In this study, we clarified the characteristics of ubiquitin-related gene pairs (UbRGPs) and identified the relationship between the status of the TME and UbRGPs of patients with LUAD. A prognostic signature based on six UbRGPs was established, which performed well in predicting the immune infiltration and tumor mutation burden (TMB) in the TME and the response of LUAD to immuno-, chemo-, and targeted therapy. In conclusion, the UbRGPs signature is an independent prognostic indicator and has great potential in assisting the clinical therapy for patients with LUAD.

Abstract

Lung adenocarcinoma (LUAD) is a common pathological type of lung cancer worldwide, and new biomarkers are urgently required to guide more effective individualized therapy for patients. Ubiquitin-related genes (UbRGs) partially participate in the initiation and progression of lung cancer. In this study, we used ubiquitin-related gene pairs (UbRGPs) in tumor tissues to access the function of UbRGs in overall survival, immunocyte infiltration, and tumor mutation burden (TMB) of patients with LUAD from The Cancer Genome Atlas (TCGA) database. In addition, we constructed a prognostic signature based on six UbRGPs and evaluated its performance in an internal (TCGA testing set) and an external validation set (GSE13213). The prognostic signature revealed that risk scores were negatively correlated with the overall survival, immunocyte infiltration, and expression of immune checkpoint inhibitor-related genes and positively correlated with the TMB. Patients in the high-risk group showed higher sensitivity to partially targeted and chemotherapeutic drugs than those in the low-risk group. This study contributes to the understanding of the characteristics of UbRGPs in LUAD and provides guidance for effective immuno-, chemo-, and targeted therapy.

Transcriptome profiles revealed high- and low-salinity water altered gill homeostasis in half-smooth tongue sole (Cynoglossus semilaevis)

Salinity is an important environmental factor that affects fish growth, development, and reproduction. As euryhaline fish, half-smooth tongue sole (Cynoglossus semilaevis) are a suitable species for deciphering the salinity adaptation mechanism of fish; however, the molecular mechanisms underlying low- and high-salinity responses remain unclear. In this study, RNA-seq was applied to characterize the genes and regulatory pathways involved in C. semilaevis gill responses to high- (32 ppt), low- (8 ppt), and control-salinity (24 ppt) water. Gills were rich in mitochondria-rich cells (MRCs) in high salinity. Compared with control, 2137 and 218 differentially expressed genes (DEGs) were identified in low and high salinity, respectively. The enriched functions of most DEGs were metabolism, ion transport, regulation of cell cycle, and immune response. The DEGs involved in oxidative phosphorylation, citrate cycle, and fatty acid metabolism were down-regulated in low salinity. For ion transport, high and low salinity significantly altered the expressions of prlr, ca12, and cftr. In cell cycle arrest and cellular repair, gadd45b, igfbp5, and igfbp2 were significantly upregulated in high and low salinity. For immune response, il10, il34, il12b, and crp increased in high and low salinity. Our findings suggested that alterations in material and energy metabolism, ions transport, cell cycle arrest, cellular repair, and immune response, are required to maintain C. semilaevis gill homeostasis under high and low salinity. This study provides insight into the divergence of C. semilaevis osmoregulation mechanisms acclimating to high and low salinity, which will serve as reference for the healthy culture of C. semilaevis.

Identification and Characterization of the Roles of circCASP9 in Gastric Cancer Based on a circRNA-miRNA-mRNA Regulatory Network

Accumulating evidence demonstrates that circular RNAs (circRNAs) have substantial effects on gastric cancer (GC) tumorigenesis and development. In this study, we performed a screen and identified two differentially expressed circRNAs (circCASP9 and circDLG5) from our circRNA microarray. We validated the expression of circCASP9 and circDLG5 in GC tissues and their normal counterparts by using qRT-PCR. Only circCASP9 was revealed to be downregulated in tumor tissues compared with adjacent normal tissues. Functionally, circCASP9 significantly inhibited the proliferation, migration, and invasion of GC cells both in vitro and in vivo. A competing endogenous RNA (ceRNA) network was constructed for the identification of candidate target genes of circCASP9. circCASP9, two miRNAs, and 55 mRNAs were selected for construction of the ceRNA network. We confirmed that circCASP9 can function as a sponge of miR-589-5p to regulate KANK1 expression, thereby controlling GC progression. Accordingly, we identified that the novel circRNA circCASP9 was differentially expressed between GC tissues and their normal counterparts. We also showed that circCASP9 can regulate the growth and metastasis of GC via the miR-589-5p/KANK1 axis. The circCASP9/miR-589-5p/KANK1 axis might provide crucial insights for investigating the occurrence and development of GC.

A Novel Pyroptosis-Related Signature for Predicting Prognosis and Indicating Immune Microenvironment Features in Osteosarcoma

Osteosarcoma is a common malignant bone tumor with a propensity for drug resistance, recurrence, and metastasis. A growing number of studies have elucidated the dual role of pyroptosis in the development of cancer, which is a gasdermin-regulated novel inflammatory programmed cell death. However, the interaction between pyroptosis and the overall survival (OS) of osteosarcoma patients is poorly understood. This study aimed to construct a prognostic model based on pyroptosis-related genes to provide new insights into the prognosis of osteosarcoma patients. We identified 46 differentially expressed pyroptosis-associated genes between osteosarcoma tissues and normal control tissues. A total of six risk genes affecting the prognosis of osteosarcoma patients were screened to form a pyroptosis-related signature by univariate and LASSO regression analysis and verified using GSE21257 as a validation cohort. Combined with other clinical characteristics, including age, gender, and metastatic status, we found that the pyroptosis-related signature score, which we named “PRS-score,” was an independent prognostic factor for patients with osteosarcoma and that a low PRS-score indicated better OS and a lower risk of metastasis. The result of ssGSEA and ESTIMATE algorithms showed that a lower PRS-score indicated higher immune scores, higher levels of tumor infiltration by immune cells, more active immune function, and lower tumor purity. In summary, we developed and validated a pyroptosis-related signature for predicting the prognosis of osteosarcoma, which may contribute to early diagnosis and immunotherapy of osteosarcoma.