TRIM55 restricts the progression of hepatocellular carcinoma through ubiquitin-proteasome-mediated degradation of NF90.

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor worldwide. Tripartite motif containing 55 (TRIM55), also known as muscle-specific ring finger 2 (Murf2), belongs to the TRIM protein family and serves as an E3 ligase. Recently, the function and mechanism of TRIM55 in the advancement of solid tumors have been elucidated. However, the role of TRIM55 and its corresponding protein substrates in HCC remains incompletely explored. In this study, we observed a significant reduction in TRIM55 expression in HCC tissues. The downregulation of TRIM55 expression correlated with larger tumor size and elevated serum alpha-fetoprotein (AFP), and predicted unfavorable overall and tumor-free survival. Functional experiments demonstrated that TRIM55 suppressed the proliferation, migration, and invasion of HCC cells in vitro, as well as hindered HCC growth and metastasis in vivo. Additionally, TRIM55 exhibited a suppressive effect on HCC angiogenesis. Mechanistically, TRIM55 interacted with nuclear factor 90 (NF90), a double-stranded RNA-binding protein responsible for regulating mRNA stability and gene transcription, thereby facilitating its degradation via the ubiquitin-proteasome pathway. Furthermore, TRIM55 attenuated the association between NF90 and the mRNA of HIF1α and TGF-ß2, consequently reducing their stability and inactivating the HIF1α/VEGF and TGFß/Smad signaling pathways. In conclusion, our findings unveil the important roles of TRIM55 in suppressing the progression of HCC partly by promoting the degradation of NF90 and subsequently modulating its downstream pathways, including HIF1α/VEGF and TGFß/Smad signaling.

The activation of the Notch signaling pathway by UBE2C promotes the proliferation and metastasis of hepatocellular carcinoma.

UBE2C, a ubiquitin-conjugating enzyme, functions as an oncogene in different types of human cancers. Nonetheless, the exact influence of UBE2C on the development of HCC via regulation of ubiquitination remains uncertain. Here, we found that UBE2C displayed elevated levels of expression in HCC and was associated with an unfavorable prognosis, as evidenced by the analysis of the TCGA database and the examination of clinical specimens. The role of UBE2C in HCC revealed its ability to promote the growth and metastasis of HCC. Mechanistically, UBE2C activated Notch signaling, as evidenced by the upregulation of N1ICD and Hes1, crucial components of the Notch pathway, and activation of the RBP-JK luciferase reporter by UBE2C. Finally, rescue experiments demonstrated that the oncogenic role of UBE2C was eliminated through treatment with the Notch inhibitor DAPT, while overexpression of N1ICD alleviated the anticarcinogenic impact of knockdown of UBE2C. Altogether, the results of our study indicate that UBE2C plays a role in the activation of Notch signaling and could potentially serve as a viable target for therapeutic interventions in HCC.

A sequence-aware merger of genomic structural variations at population scale.

Merging structural variations (SVs) at the population level presents a significant challenge, yet it is essential for conducting comprehensive genotypic analyses, especially in the era of pangenomics. Here, we introduce PanPop, a tool that utilizes an advanced sequence-aware SV merging algorithm to efficiently merge SVs of various types. We demonstrate that PanPop can merge and optimize the majority of multiallelic SVs into informative biallelic variants. We show its superior precision and lower rates of missing data compared to alternative software solutions. Our approach not only enables the filtering of SVs by leveraging multiple SV callers for enhanced accuracy but also facilitates the accurate merging of large-scale population SVs. These capabilities of PanPop will help to accelerate future SV-related studies.

Heat shock protein HSPA13 promotes hepatocellular carcinoma progression by stabilizing TANK.

HSPA13, an important member of the heat shock protein family, plays an essential role in the oncogenesis of many organs, but the mechanism and function in hepatocellular carcinoma (HCC) is still unclear. In the present study, we found that HSPA13 was highly expressed in HCC and predicted poor clinical prognosis. Upregulation of HSPA13 was significantly associated with vascular invasion in HCC patients. Functionally, knockdown experiments demonstrated that HSPA13 promoted HCC proliferation, migration, and invasion. Mechanistic investigation showed that HSPA13 could interact with TANK to inhibit its ubiquitination and degradation. In addition, the expression of HSPA13 and TANK were positively correlated in HCC tissues. To conclude, the present study uncovers the oncogenic function of HSPA13 in the progression of HCC by regulating the stability of TANK. These findings suggest that HSPA13 and TANK may serve as promising targets for the diagnosis and treatment of HCC.

Metformin synergistically enhances the antitumour activity of Lenvatinib in hepatocellular carcinoma by altering AKT-FOXO3 signalling pathway.

BACKGROUND AND AIMS: Lenvatinib is a first-line drug commonly used in the treatment of advanced hepatocellular carcinoma (HCC). However, its clinical efficacy is very limited due to drug resistance. Therefore, there is a great need to explore its combination with other agents to achieve better therapeutic effects. Metformin has been demonstrated to show an anti-cancer effect. This study aimed to investigate the combined effect of lenvatinib with metformin in HCC cells both in vitro and in vivo and elucidate the possible molecular mechanisms. METHODS: Flow cytometry, colony formation, CCK-8 and transwell assays were used to study the effect of Lenvatinib-Metformin combination on the malignant behaviour of HCC cells in vitro. Constructing an animal model of tumour-bearing to study the effect of combined drugs on HCC in vivo. Western blot experiments were performed to assess the relationship between AKT and FOXO3 and the cellular translocation of FOXO3. RESULTS: Our results suggested that Lenvatinib and Metformin synergistically inhibited HCC growth and motility. Mechanistically, the combination of Lenvatinib and Metformin synergistically suppressed the activation of the AKT signalling pathway, which in turn reduced the phosphorylation level of downstream effector FOXO3 and induced its nuclear aggregation. In vivo studies further confirmed the synergistic suppression of lenvatinib with metformin in HCC growth. CONCLUSION: The Lenvatinib-Metformin combination may provide a potential therapeutic strategy to improve the prognosis of HCC patients.

Upregulation of helicase-like transcription factor predicts poor prognosis and facilitates hepatocellular carcinoma progression.

Helicase-like transcription factor (HLTF) belongs to the family of SWI/SNF proteins, which has been reported to exert oncogenic function in several human cancers. However, to date, its functional role in hepatocellular carcinoma (HCC) has not been revealed. Here, we found that HLTF was highly expressed in HCC tissues compared to nontumor tissues. Additionally, upregulation of HLTF was significantly associated with poor prognosis of patients with HCC. Functional experiments demonstrated that knockdown of HLTF expression significantly inhibited the proliferation, migration, and invasion of HCC cells in vitro, and suppressed tumor growth in vivo. In conclusion, our results suggest that upregulation of HLTF is associated with the development of HCC, and HLTF may be a potential therapeutic target for HCC treatment.