The TRAF2-p62 axis promotes proliferation and survival of liver cancer by activating mTORC1 pathway

ASB1 engages with ELOB to facilitate SQOR ubiquitination and H2S homeostasis during spermiogenesis

Male infertility, frequently driven by oxidative stress, impacts half of infertile couples globally. Despite its significance, the precise mechanisms governing this process remain elusive. In this study, we demonstrate that ASB1, the substrate recognition subunit of a ubiquitin ligase, is highly expressed in the mouse testis. Mice lacking the Asb1 gene exhibit severe fertility impairment, characterized by oligoasthenoteratozoospermia. Subsequent investigations unveiled that Asb1 knockout (Asb1-KO) mice encountered excessive oxidative stress and decreased hydrogen sulfide (H2S) levels in their testes, and severe sperm DNA damage. Notably, the compromised fertility and sperm quality in Asb1-KO mice was significantly ameliorated by administering NaHS, a H2S donor. Mechanistically, ASB1 interacts with ELOB to induce the instability of sulfide-quinone oxidoreductase (SQOR) by enhancing its K48-linked ubiquitination on residues K207 and K344, consequently triggering proteasomal degradation. This process is crucial for preserving H2S homeostasis and redox balance. Overall, our findings offer valuable insights into the role of ASB1 during spermiogenesis and propose H2S supplementation as a promising therapeutic approach for oxidative stress-related male infertility.

Causal Inference and Annotation of Phosphoproteomics Data in Multi-omics Cancer Studies

Protein phosphorylation plays a crucial role in regulating diverse biological processes. Perturbations in protein phosphorylation are closely associated with downstream pathway dysfunctions, while alterations in protein expression could serve as sensitive indicators of pathological status. However, there are currently few methods that can accurately identify the regulatory links between protein phosphorylation and expression, given issues like reverse causation and confounders. Here, we present Phoslink, a causal inference model to infer causal effects between protein phosphorylation and expression, integrating prior evidence and multi-omics data. We demonstrated the feasibility and advantages of our method under various simulation scenarios. Phoslink exhibited more robust estimates and lower FDR than commonly used Pearson and Spearman correlations, with better performance than canonical IV selection methods for Mendelian randomization. Applying this approach, we identified 345 causal links involving 109 phosphosites and 310 proteins in 79 lung adenocarcinoma (LUAD) samples. Based on these links, we constructed a causal regulatory network and identified 26 key regulatory phosphosites as regulators strongly associated with LUAD. Notably, 16 of these regulators were exclusively identified through phosphosite-protein causal regulatory relationships, highlighting the significance of causal inference. We explored potentially druggable phosphoproteins and provided critical clues for drug repurposing in LUAD. We also identified significant mediation between protein phosphorylation and LUAD through protein expression. In summary, our study introduces a new approach for causal inference in phosphoproteomics studies. Phoslink demonstrates its utility in potential drug target identification thereby accelerating the clinical translation of cancer proteomics and phosphoproteomic data.

Transcriptome analysis displays new molecular insights into the mechanisms of action of Mebendazole in gastric cancer cells

Gastric cancer (GC) is a common cancer worldwide. Therefore, searching for effective treatments is essential, and drug repositioning can be a promising strategy to find new potential drugs for GC therapy. For the first time, we sought to identify molecular alterations and validate new mechanisms related to Mebendazole (MBZ) treatment in GC cells through transcriptome analysis using microarray technology. Data revealed 1066 differentially expressed genes (DEGs), of which 345 (2.41 %) genes were upregulated, 721 (5.04 %) genes were downregulated, and 13,231 (92.54 %) genes remained unaltered after MBZ exposure. The overexpressed genes identified were CCL2, IL1A, and CDKN1A. In contrast, the H3C7, H3C11, and H1-5 were the top 3 underexpressed genes. Gene set enrichment analysis (GSEA) identified 8 pathways significantly overexpressed in the treated group (p < 0.05 and FDR<0.25). The validation of the expression of top desregulated genes by RT-qPCR confirmed the transcriptome results, where MBZ increased the CCL2, IL1A, and CDKN1A and reduced the H3C7, H3C11, and H1-5 transcript levels. Expression analysis in samples from TCGA databases correlated that the lower ILI1A and higher H3C11 and H1-5 gene expression are associated with decreased overall survival rates in patients with GC, indicating that MBZ treatment can improve the prognosis of patients. Thus, the data demonstrated that the drug MBZ alters the transcriptome of the AGP-01 lineage, mainly modulating the expression of histone proteins and inflammatory cytokines, indicating a possible epigenetic and immunological effect on tumor cells, these findings highlight new mechanisms of action related to MBZ treatment. Additional studies are still needed to better clarify the epigenetic and immune mechanism of MBZ in the therapy of GC.

Lactoferrin targeting INTL1 receptor inhibits hepatocellular carcinoma progression via apoptosis and cell cycle signaling pathways

Hepatocellular carcinoma (HCC) constitutes 90% of liver cancer cases and ranks as the third leading cause of cancer-related mortality, necessitating urgent development of alternative therapies. Lactoferrin (LF), a natural iron-binding glycoprotein with reported anticancer effects, is investigated for its potential in liver cancer treatment, an area with limited existing studies. This study focuses on evaluating LF's anti-liver cancer effects on HCC cells and assessing the preventive efficacy of oral LF administration in a murine model. Data showed that LF exerted anti-proliferative effects on HepG2, Hep3B, and SK-Hep1 cells while having no cytotoxicity on healthy liver cells (FL83B). Mechanistically, LF induces mitochondrial-mediated apoptosis and G0/G1 cell cycle arrest in HepG2 cells, associated with increased phosphorylation of p38 MAPK and JNK for apoptosis, and ERK phosphorylation for cell cycle arrest. Intelectin-1 (INTL1) is identified as the receptor facilitating LF endocytosis in HepG2 cells, and downregulation of INTL1 inhibits LF-induced signaling pathways. Notably, oral LF administration prevents HCC development in nude mice with orthotopic HepG2 cell injection. This study unveils the mechanistic basis of LF action in HepG2 cells, showcasing its potential in HCC prevention. Importantly, we report the novel identification of INTL1 as the LF receptor in HepG2 cells, providing valuable insights for future exploration of LF and its derivatives in liver cancer therapy.

Ubiquitination of CD47 Regulates Innate Anti-Tumor Immune Response

In addition to adaptive immune checkpoint of PD-1/PD-L1, the innate immune checkpoint SIRPα/CD47 plays an important role in regulation of tumor immune escape. However, the mechanism of CD47 ubiquitination on tumor immune escape remains unclear. Here it is found that TRAF2 bound to the C-terminal of CD47 cytoplasmic fragment and induced its ubiquitination, leading to inhibition of CD47 autophagic degradation by disrupting its binding to LC3, which in turn inhibited macrophage phagocytosis and promoted tumor immune escape. In contrast, loss of TRAF2 facilitated CD47 autophagic degradation and inhibited tumor immune escape. Moreover, autophagy induction promoted CD47 degradation and enhanced the efficacy of CD47 antibody anti-tumor immunotherapy. These findings revealed a novel mechanism of ubiquitination of CD47 on tumor immune escape.

Targeting autophagy in HCC treatment: exploiting the CD147 internalization pathway

BACKGROUND/AIMS

Chemotherapy resistance in liver cancer is a major clinical issue, with CD147 playing a vital role in this process. However, the specific mechanisms underlying these processes remain largely unknown. This study investigates how CD147 internalization leads to cytoprotective autophagy, contributing to chemotherapy resistance in hepatocellular carcinoma (HCC).

METHODS

Utilizing bioinformatics methods for KEGG pathways enrichment and screening key molecules associated with chemotherapy resistance through analyses of GEO and TCGA databases. An overexpression/knockdown system was used to study how CD147 internalization leads to autophagy in vitro and in vivo. The process was observed using microscopes, and molecular interactions and autophagy flux were analyzed. Analyzing the internalization of CD147 intracellular domains and the interaction with G3BP1 in clinical chemotherapy recurrence HCC tissues by immunohistochemistry, tissue immunofluorescence, and mass spectrometry. A tumor xenograft mice model was used to study cytoprotective autophagy induced by CD147 and test the effectiveness of combining cisplatin with an autophagy inhibitor in nude mice models.

RESULTS

In our study, we identified the tumor-associated membrane protein CD147, which implicated in chemoresistance lysosome pathways, by evaluating its protein degree value and betweenness centrality using Cytoscape. Our findings revealed that CD147 undergoes internalization and interacts with G3BP1 following treatment with cisplatin and methyl-β-cyclodextrin, forming a complex that is transported to lysosomes via Rab7A. Notably, higher doses of cisplatin enhanced CD147-mediated lysosomal transport while concurrently inhibiting SG assembly. The CD147-G3BP1 complex additionally inhibits mTOR activity, promoting autophagy and augmenting chemoresistance in hepatoma cells. In vivo studies investigations and analyses of clinical samples revealed that elevated internalization of CD147 is associated with chemotherapy recurrence in liver cancer and the maintenance of stem cells. Mice experiments found that the combined administration of cisplatin and hydroxychloroquine enhanced the efficacy of treatment.

CONCLUSIONS

This study reveals that CD147 internalization and CD147-G3BP1 complex translocation to lysosomes induce cytoprotective autophagy, reducing chemotherapy sensitivity by suppressing mTOR activity. It is also shown that chemotherapy drugs combined with autophagy inhibitors can improve the therapeutic effect of cancer, providing new insights into potential targeted therapeutic approaches in treating HCC.

Interactions between polycyclic aromatic hydrocarbons and genetic variants in the cGAS-STING pathway affect the risk of colorectal cancer

The cGAS-STING pathway plays an essential role in the activation of tumor immune cells. Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants with potential carcinogenicity, and their exposure is associated with the development of colorectal cancer. However, the impacts of genetic factors in the cGAS‒STING pathway and gene‒environment interactions on colorectal cancer remain understudied. We used logistic regression models and interaction analysis to evaluate the impact of genetic variants on colorectal cancer risk and gene‒environment interactions. We analysed the expression patterns of candidate genes based on the RNA-seq data. Molecular biology experiments were performed to investigate the impact of PAHs exposure on candidate gene expression and the progression of colorectal cancer. We identified the susceptibility locus rs3750511 in the cGAS‒STING pathway, which is associated with colorectal cancer risk. A negative interaction between TRAF2 rs3750511 and PAHs exposure was also identified. Single-cell RNA-seq analysis revealed significantly elevated expression of TRAF2 in colorectal cancer tissues compared with normal tissues, especially in T cells. BPDE exposure increased TRAF2 expression and the malignant phenotype of colorectal cancer cells. The treatment also further increased the expression of the TRAF2 downstream gene NF-κB and decreased the expression of Caspase8. Our results suggest that the genetic variant of rs3750511 affects the expression of TRAF2, thereby increasing the risk of colorectal cancer through interaction with PAHs. Our study provides new insights into the influence of gene‒environment interactions on the risk of developing colorectal cancer.

USP24 promotes hepatocellular carcinoma tumorigenesis through deubiquitinating and stabilizing TRAF2

Ubiquitin-specific peptidase 24 (USP24), a member of the deubiquitinase family, plays an important role in tumor regulation. However, the role of USP24 in Hepatocellular carcinoma（HCC）is unknown. The aim of our study was to explore the role of USP24 in HCC to seek new therapeutic targets for HCC. In this study, we found that USP24 was aberrantly upregulated in HCC tissues and predicted poor prognosis. USP24 markedly promoted HCC proliferation and progression in vitro and in vivo. Mechanistically, USP24 binds to tumor necrosis factor receptor-associated factor 2(TRAF2) and inhibits its degradation, thereby promoting the accumulation of TRAF2. Upregulation of TRAF2 activated protein kinase B/nuclear factor kappa-B (AKT/ NF-κB) signaling pathway and promoted HCC cell survival. In addition, USP24 positively correlated with programmed cell death ligand 1(PD-L1) expression in HCC, highlighting the clinical significance of USP24 activation in tumor immune evasion. Deletion of USP24 enhanced the tumor-killing ability of CD8+ T cells. Deletion of USP24 combined with anti-PD-1 antibody significantly enhanced the efficacy of HCC immunotherapy. Taken together, USP24 can be employed as a promising target to restrain tumor growth and increase the efficacy of HCC immunotherapy.

Transcription factor E2F4 facilitates SUMOylation to promote HCC progression through interaction with LIN9

SUMOylation plays a crucial role in numerous cellular biological and pathophysiological processes associated with human disease; however, the mechanisms regulating the genes involved in SUMOylation remain unclear. In the present study, E2F transcription factor 4 (E2F4) was identified as an E2F member related to hepatocellular carcinoma (HCC) progression by public database analysis. It was found that E2F4 promoted the proliferation and invasiveness of HCC cells via SUMOylation using Soft agar and Transwell migration assays. Mechanistically, it was demonstrated that E2F4 upregulated the transcript and protein expression levels of baculoviral IAP repeat containing 5, cell division cycle associated 8 and DNA topoisomerase II α using western blotting. Furthermore, the interaction between E2F4 with lin‑9 DREAM multi‑vulva class B core complex component (LIN9) was explored by co‑immunoprecipitation, immunofluorescence co‑localization and bimolecular fluorescence complementation assays. Moreover, it was demonstrated that E2F4 promoted the progression of HCC cells via LIN9. Rescue experiments revealed that LIN9 facilitated the SUMOylation and proliferation of HCC cells, which was prevented by knocking down E2F4 expression. In conclusion, the findings of the present study indicated that E2F4 plays a major role in the proliferation of HCC cells and may be a potential therapeutic target in the future.

Therapeutic Potential of Terpenoids in Cancer Treatment: Targeting Mitochondrial Pathways

BACKGROUND

In recent decades, natural compounds have been considered a significant source of new antitumor medicines due to their unique advantages. Several in vitro and in vivo studies have focused on the effect of terpenoids on apoptosis mediated by mitochondria in malignant cells.

RECENT FINDINGS

In this review article, we focused on six extensively studied terpenoids, including sesquiterpenes (dihydroartemisinin and parthenolide), diterpenes (oridonin and triptolide), and triterpenes (betulinic acid and oleanolic acid), and their efficacy in targeting mitochondria to induce cell death. Terpenoid-induced mitochondria-related cell death includes apoptosis, pyroptosis, necroptosis, ferroptosis, autophagy, and necrosis caused by mitochondrial permeability transition. Apoptosis and autophagy interact in meaningful ways. In addition, in view of several disadvantages of terpenoids, such as low stability and bioavailability, advances in research on combination chemotherapy and chemical modification were surveyed.

CONCLUSION

This article deepens our understanding of the association between terpenoids and mitochondrial cell death, presenting a hypothetical basis for the use of terpenoids in anticancer management.

SERPINH1 modulates apoptosis by inhibiting P62 ubiquitination degradation to promote bone metastasis of prostate cancer

Prostate cancer (PCa) is one of the most prevalent urogenital malignancies. Bone metastasis from PCa reduces patient survival rates significantly. There currently exists no effective treatment for bone metastatic PCa, and the underlying mechanisms remain unclear. This study performed transcriptomic screening on PCa bone metastasis specimens and intersection analysis in public databases and identified SERPINH1 as a potential target for treatment. SERPINH1 was found to be upregulated in PCa bone metastases and with poor prognosis, high Gleason score, and advanced metastatic status. SERPINH1 induced PCa cells' bone metastasis in vivo, promoted their proliferation, and mitigated apoptosis. Mechanistically, SERPINH1 bound to P62, reducing TRIM21-mediated K63-linked ubiquitination degradation of P62 and promoting proliferation and resistance to apoptosis of PCa. This study suggests the regulation of ubiquitination degradation of P62 by SERPINH1 that promotes PCa bone metastasis and can be considered as a potential target for treatment of bone metastatic PCa.

Hyper-methylation and DNMT3A mediated LTC4S downregulation promoted lung adenocarcinoma tumorigenesis via mTORC1 signaling pathway

Background

Lung adenocarcinoma is a malignancy characterized by high mortality rates and unfavorable prognosis. However, the role of Leukotriene C4 Synthase (LTC4S) in lung cancer remains uninvestigated.

Methods

The expression and prognostic value of LTC4S in LUAD were analyzed using the GEPIA online database. Subsequently, the function of LTC4S in lung cancer cells was examined through gain-of function experiments, using assays to evaluate tumor malignant behavior. Subcutaneous xenograft experiments in vivo was used for investigating the functions of LTC4S. Then, tumor hallmark pathways were analyzed by GSEA. Western blot assay was used to validate the impact of LTC4S on mTORC1 pathway. Finally, the correlation of mRNA and methylation of LTC4S were analyzed by cBioPortal. qRT-PCR, ChIP-qPCR and ChIP-Atlas were used to verify the regulation factors of LTC4S low expression in LUAD cells.

Results

LTC4S presented significant decreased expression and favorable prognostic significance in LUAD. LTC4S was correlated with clinical stages in LUAD, which showed decreased expression gradually and significantly along with TNM stages. LTC4S-co-expressed genes were closely related to Ras signaling pathway, and MAPK signaling pathway. Overexpression of LTC4S inhibited cancer malignant phenotype and tumor growth in vitro and vivo. GSEA analysis and Western blot assay suggested low expression of LTC4S activated mTORC1 signaling pathway in LUAD. Moreover, the DNA methylation level of LTC4S in LUAD tissue was markedly elevated compared to normal tissue. The hypermethylation of the LTC4S promoter by DNMT3A leads to the decreased expression of LTC4S in LUAD.

Conclusions

In conclusion, low expression of LTC4S serves as an unfavorable prognostic marker and the critical function of LTC4S in controlling the progression of LUAD. This highlights the promise for exploring the clinical benefits of manipulating LTC4S in LUAD targeted therapies.

Associations of TRAF2 (rs867186), TAB2 (rs237025), IKBKB (rs13278372) Polymorphisms and TRAF2, TAB2, IKBKB Protein Levels with Clinical and Morphological Features of Pituitary Adenomas

AIM

The aim of this study was to determine associations of TRAF2 (rs867186), TAB2 (rs237025), IKBKB (rs13278372) gene polymorphisms and TRAF2, TAB2, IKBKB protein levels with clinical and morphological features of pituitary adenomas (PAs).

METHODS

This case-control study included 459 individuals divided into two groups: a control group (n = 320) and a group of individuals with PAs (n = 139). DNA from peripheral blood leukocytes was isolated using salt precipitation and column method. Real-time PCR was used for TRAF2 (rs867186), TAB2 (rs237025), and IKBKB (rs13278372) SNP genotyping, and TRAF2, TAB2, IKBKB protein concentration measurements were performed by immunoenzymatic analysis tests using a commercial ELISA kit according to the manufacturer's recommendations. The labeling index Ki-67 was determined by immunohistochemical analysis using a monoclonal antibody (clone SP6; Spring Bioscience Corporation). Statistical data analysis was performed using the programs "IMB SPSS Statistics 29.0".

RESULTS

We found significant differences in TRAF2 (rs867186) genotypes (AA, AG, GG) between groups: 79.1%, 17.3%, 3.6% vs. 55.3%, 20.9%, 23.8% (p < 0.001). The G allele was less frequent in the PA group than in controls (12.2% vs. 34.2%, p < 0.001). The AG and GG genotypes reduced PA occurrence by 1.74-fold and 9.43-fold, respectively, compared to AA (p < 0.001). In the dominant model, GG and AG genotypes reduced PA odds by 3.07-fold, while in the recessive model, the GG genotype reduced PA odds by 8.33-fold (p < 0.001). Each G allele decreased PA odds by 2.49-fold in the additive model (p < 0.001). Microadenomas had significant genotype differences compared to controls: 81.3%, 18.8%, 0.0% vs. 55.3%, 20.9%, 23.8% (p < 0.001), with the G allele being less frequent (9.4% vs. 34.2%, p < 0.001). In macroadenomas, genotype differences were 78%, 16.5%, 5.5% vs. 55.3%, 20.9%, 23.8% (p < 0.001), and the G allele was less common (13.7% vs. 34.2%, p < 0.001). The dominant model showed that GG and AG genotypes reduced microadenoma odds by 3.5-fold (p = 0.001), and each G allele reduced microadenoma odds by 3.1-fold (p < 0.001). For macroadenomas, the GG genotype reduced odds by 6.1-fold in the codominant model (p < 0.001) and by 2.9-fold in GG and AG genotypes combined compared to AA (p < 0.001). The recessive model indicated the GG genotype reduced macroadenoma odds by 5.3-fold (p < 0.001), and each G allele reduced odds by 2.2-fold in the additive model (p < 0.001).

CONCLUSIONS

The TRAF2 (rs867186) G allele and GG genotype are significantly associated with reduced odds of pituitary adenomas, including both microadenomas and macroadenomas, compared to the AA genotype. These findings suggest a protective role of the G allele against the occurrence of these tumors.

TRAF2 decrease promotes the TGF-β-mTORC1 signal in MAFLD-HCC through enhancing AXIN1-mediated Smad7 degradation

According to recent research, metabolic-associated fatty liver disease (MAFLD) has emerged as an important underlying etiology of hepatocellular carcinoma (HCC). However, the molecular mechanism of MAFLD-HCC is still unclear. Tumor necrosis factor receptor-associated factor 2 (TRAF2) is the key molecule to mediate the signal of inflammatory NF-κB pathway. This study aims to investigate the potential dysregulation of TRAF2 and its biological function in MAFLD-HCC. Huh7 TRAF2-/- demonstrated increased tumor formation ability compared to huh7 TRAF2+/+ when stimulated with transforming growth factor-β (TGF-β). The decisive role of TGF-β in the development of MAFLD-HCC was confirmed through the specific depletion of TGF-β receptor II gene in the hepatocytes (Tgfbr2ΔHep) of mice. In TRAF2-/- cells treated with TGF-β, both the glycolysis rate and lipid synthesis were enhanced. We proved the signal of the mechanistic target of rapamycin complex 1 (mTORC1) could be activated in the presence of TGF-β, and was enhanced in TRAF2-/- cells. The coimmunoprecipitation (co-IP) experiments revealed that TRAF2 fortified the Smurf2-mediated ubiquitination degradation of AXIN1. Hence, TRAF2 depletion resulted in increased Smad7 degradation induced by AXIN1, thus promoting the TGF-β signal. We also discovered that PLX-4720 could bind with AXIN1 and restrained the tumor proliferation of TRAF2-/- in mice fed with high-fat diet (HFD). Our findings indicate that TRAF2 plays a significant role in the pathogenesis of MAFLD-HCC. The reduction of TRAF2 expression leads to the enhancement of the TGF-β-mTORC1 pathway by facilitating AXIN1-mediated Smad7 degradation.

Unlocking hepatocellular carcinoma aggression: STAMBPL1-mediated TRAF2 deubiquitination activates WNT/PI3K/NF-kb signaling pathway

STAM Binding Protein Like 1 (STAMBPL1), functions as a deubiquitinase (DUB) and plays a significant role in various types of cancers. However, its effect as a DUB participating in the HCC tumorigenesis and progression still unknown. In the study, the upregulation and strong prognosis value of STAMBPL1 were identified in HCC patients. Functionally, STAMBPL1 significantly promoted HCC cells proliferation and metastasis, and it interacts with TRAF2 and stabilize it via the deubiquitination at the K63 residue. The TRAF2 upregulation stabilized by STAMBPL1 overexpression transfers of P65 protein into the nucleus and activates the WNT/PI3K/ NF-kb signaling pathway. The 251-436 sites of STAMBPL1 particularly interact with the 294-496 sites of TRAF2, thereby exerting the function of DUB and removing the ubiquitin molecules attached to TRAF2. Our research unveiled a new function of STAMBPL1 in mediating TRAF2 deubiquitination and stabilization, thereby activating the WNT/PI3K/NF-kb signaling pathway, suggesting its potential as a novel biomarker and therapeutic target for HCC.

Nuclear-cytoplasmic translocation of SQSTM1/p62 protein enhances ESCC cell migration and invasion by stabilizing EPLIN expression

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignant disease with a poor prognosis. We previously found that p62 presented a marked nuclear-cytoplasmic translocation in ESCC cells as compared that in normal esophageal epithelial cells, but its effects on ESCC cells remain unclear. This study aims to clarify the impacts of different cellular localization of p62 on the function of ESCC cells and the underlying molecular mechanisms. We here demonstrated that cytoplasmic p62 enhances the migration and invasion abilities of esophageal cancer cells, whereas nuclear p62 has no effect. We further explored the interaction protein of p62 by using GST pull-down experiment and identified EPLIN as a potential protein interacting with p62. In addition, reducing EPLIN expression significantly inhibited the migration and invasion of ESCC cells, which were rescued when EPLIN expression was restored after the p62 knockdown. At a molecular level, p62 in cytoplasm positively regulated the expression of EPLIN via enhancing its protein stability. Data from the TCGA and GEO database displayed a significant up-regulation of EPLIN mRNA expression in ESCC tissues compared with corresponding paired esophageal epithelial samples. Our findings present evidence that the nuclear-cytoplasmic translocation of p62 protein contributes to an aggressive malignancy phenotype, providing candidate molecular biomarkers and potential molecular targets for the diagnosis and treatment of ESCC.

TRAF2 inhibits senescence in hepatocellular carcinoma cells via regulating the ROMO1/ NAD+/SIRT3/SOD2 axis

The suppression of tumor proliferation via cellular senescence has emerged as a promising approach for anti-tumor therapy. Tumor necrosis factor receptor-associated factor 2 (TRAF2), an adaptor protein involved in the NF-κB signaling pathway and reactive oxygen species (ROS) production, has been implicated in hepatocellular carcinoma (HCC) proliferation. However, little is currently known about whether TRAF2 promotes HCC development by inhibiting cellular senescence. Replicative senescence model and IR-induced mouse model demonstrated that TRAF2 expression was decrease in senescence cells or liver tissues. Depletion of TRAF2 could inhibit proliferation and arrest the cell cycle via activating p53/p21WAF1 and p16INK4a/pRb signaling pathways in HCC cells and eventually lead to cellular senescence. Mechanistically, TRAF2 deficiency increased the expression of mitochondrial protein reactive oxygen species modulator 1 (ROMO1) and subsequently activated the NAD+/SIRT3/SOD2 pathway to promote the production of ROS and cause mitochondrial dysfunction, which eventually contributed to DNA damage response (DDR). Our findings demonstrate that TRAF2 deficiency inhibits the proliferation of HCC by promoting senescence. Therefore, targeting TRAF2 through various approaches holds therapeutic potential for treating HCC.

Genomic and transcriptomic profiling of hepatocellular carcinoma reveals a rare molecular subtype

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide, occurring predominantly in patients with underlying chronic liver disease and cirrhosis. Here, we describe a case of a 62-year-old man that was admitted to our hospital and diagnosed with HCC where the cancer has already metastasized to the retroperitoneum and peritoneum. In order to better characterize the HCC, both the cancerous liver tissue and the adjacent normal liver tissue of the patient were collected and subjected to a genomic, transcriptomic and proteomic analysis. Our patient carries a highly mutated HCC, which is characterized by both somatic mutation in the following genes ALK, CDK6, TP53, PGR. In addition, we observe several molecular alterations that are associated with potential therapy resistance, for example the expression of the organic-anion-transporting polypeptide (OATP) family members B1 and B3, that mediate the transport of the anticancer drugs, has been found decreased. Overall, our molecular profiling potentially classify the patient with poor prognosis and possibly displaying resistance to pharmacological therapy.

Regulation of apoptosis by ubiquitination in liver cancer

Apoptosis is a programmed cell death process critical to cell development and tissue homeostasis in multicellular organisms. Defective apoptosis is a crucial step in the malignant transformation of cells, including hepatocellular carcinoma (HCC), where the apoptosis rate is higher than in normal liver tissues. Ubiquitination, a post-translational modification process, plays a precise role in regulating the formation and function of different death-signaling complexes, including those involved in apoptosis. Aberrant expression of E3 ubiquitin ligases (E3s) in liver cancer (LC), such as cellular inhibitors of apoptosis proteins (cIAPs), X chromosome-linked IAP (XIAP), and linear ubiquitin chain assembly complex (LUBAC), can contribute to HCC development by promoting cell survival and inhibiting apoptosis. Therefore, the review introduces the main apoptosis pathways and the regulation of proteins in these pathways by E3s and deubiquitinating enzymes (DUBs). It summarizes the abnormal expression of these regulators in HCC and their effects on cancer inhibition or promotion. Understanding the role of ubiquitination in apoptosis and LC can provide insights into potential targets for therapeutic intervention.