Elevated FBXL6 activates both wild-type KRAS and mutant KRASG12D and drives HCC tumorigenesis via the ERK/mTOR/PRELID2/ROS axis in mice

ZSCAN16 expedites hepatocellular carcinoma progression via activating TBC1D31

OBJECTIVE

Hepatocellular carcinoma (HCC) is fatal and poses great challenges to early diagnosis and effective treatment. This paper sought to expound the function of Zinc finger and SCAN domain-containing protein 16 (ZSCAN16) and TBC1 domain family member 31 (TBC1D31) in HCC progression.

METHODS

ZSCAN16 and TBC1D31 levels were detected by RT-qPCR, Western blot, and immunohistochemistry. The transcriptional regulation of TBC1D31 by ZSCAN16 was demonstrated by ChIP-qPCR and dual-luciferase assay. Colony formation assay, migration and invasion assays, TUNEL staining, CCK-8 assay, flow cytometry, and western blot analysis were adopted to evaluate the biological activity of HCC cells. The role of the ZSCAN16/TBC1D31 axis in HCC was demonstrated by lentiviral gene intervention combined with functional rescue experiments. Hep3B cells were used to establish a nude mouse xenograft tumor model to study the role of the ZSCAN16/TBC1D31 axis in vivo.

RESULTS

ZSCAN16 and TBC1D31 were highly expressed in HCC. Downregulation of ZSCAN16 repressed the proliferation, migration, and invasion of HCC cells while promoting apoptosis, as well as curbing tumor growth in vivo. Mechanistic studies showed that ZSCAN16 mediated the transcriptional activation of TBC1D31, which in turn led to tumor development. TBC1D31 overexpression reversed the inhibitory effect of ZSCAN16 knockdown on the malignant behavior and tumor growth of HCC cells and accelerated tumor development.

CONCLUSION

ZSCAN16 mediates transcriptional activation of TBC1D31 and promotes HCC progression.

CTHRC1 modulates cell proliferation and invasion in hepatocellular carcinoma by DNA methylation

BACKGROUND

Collagen triple helix repeat containing-1 (CTHRC1), an extracellular matrix protein, is highly expressed in hepatocellular carcinoma (HCC) and linked to poor prognosis. Nevertheless, the precise mechanism of CTHRC1 in HCC is unclear.

METHODS

Agena MassARRAY® Methylation Analysis assessed the methylation level of CTHRC1 in the promoter region. Functional assays were conducted to investigate the effects of CTHRC1 knockdown in Hep3B2.1 cells. RNA sequencing identified differentially expressed genes and lncRNAs associated with angiogenesis after CTHRC1 knockdown. Furthermore, differential alternative splicing (AS) and gene fusion events were analyzed using rMATS and Arriba.

RESULTS

In HCC cell lines, CTHRC1 was highly expressed and associated with hypomethylation. Downregulation of CTHRC1 inhibited Hep3B2.1 cell proliferation, migration, and invasion, blocked cells in the G1/S phase, and promoted apoptosis. We obtained 34 mRNAs and 7 lncRNAs differentially expressed between the NC and CTHRC1 inhibitor groups. Additionally, we found 4 angiogenesis-related mRNAs and lncRNAs significantly correlated with CTHRC1. RT-qPCR results showed that knockdown of CTHRC1 in Hep3B2.1 cells resulted in significantly aberrant expression of CXCL6, LINC02127, and AC020978.8. Moreover, the role of CTHRC1 in HCC development may be associated with events, like 12 AS events and 5 pairs of fusion genes.

CONCLUSIONS

High expressed CTHRC1 is associated with hypomethylation and may promote HCC development, involving events like angiogenesis, alternative splicing, and gene fusion.

FBXO22 promotes osteosarcoma progression via regulation of FOXO1 for ubiquitination and degradation

Accumulating evidence has demonstrated that F-box protein 22 (FBXO22) participates in tumour development and progression in various types of human malignancies. However, the functions and detailed molecular mechanisms of FBXO22 in osteosarcoma tumorigenesis and progression remain elusive. In this study, we aimed to determine the effects of FBXO22 on the cell proliferation, migration and invasion of osteosarcoma cells using cell counting kit-8 and Matrigel Transwell approaches. Moreover, we explored the molecular mechanisms by which FBXO22 mediated oncogenesis and progression in osteosarcoma via Western blotting, immunoprecipitation and ubiquitination. We found that FBXO22 depletion inhibited the proliferation, migration and invasion of osteosarcoma cells, whereas FBXO22 overexpression increased the proliferation and motility of osteosarcoma cells. Mechanistically, FBXO22 promoted the ubiquitination and degradation of FoxO1 in osteosarcoma cells. FBXO22 depletion reduced cell proliferation and motility via regulation of FoxO1. Taken together, our findings provide new insight into FBXO22-induced osteosarcoma tumorigenesis. The inhibition of FBXO22 could be a promising strategy for the treatment of osteosarcoma.

Comprehensive Bioinformatics Analysis and Machine Learning of TTK as a Transhepatic Arterial Chemoembolization Resistance Target in Hepatocellular Carcinoma

Transhepatic arterial chemoembolization (TACE) is the standard treatment for intermediate-stage hepatocellular carcinoma (HCC). However, a significant proportion of patients are non-responders or poor responders to TACE. Therefore, our aim is to identify the targets of TACE responders or non-responders. GSE104580 was utilized to identify differentially expressed genes (DEGs) in TACE responders and non-responders. Following the protein-protein interaction (PPI) analysis, hub genes were identified using the MCC and MCODE plugins in Cytoscape software, as well as LASSO regression analysis. Gene set enrichment analysis (GSEA) was performed to investigate potential mechanisms. Subsequently, the hub genes were validated using data from The Cancer Genome Atlas (TCGA), the Cancer Cell Line Encyclopedia (CCLE), and The Human Protein Atlas (HPA) database. To evaluate the clinical significance of the hub genes, Kaplan-Meier (KM) survival and Cox regression analysis were employed. A total of 375 DEGs were identified, with 126 remaining following PPI analysis, and TTK, a dual-specificity protein kinase associated with cell proliferation, was ultimately identified as the hub gene through multiple screening methods. Data analysis from TCGA, CCLE, and HPA databases revealed elevated TTK expression in HCC tissues. GSEA indicated that the cell cycle, farnesoid X receptor pathway, PPAR pathway, FOXM1 pathway, E2F pathway, and ferroptosis could be potential mechanisms for TACE non-responders. Analysis of immune cell infiltration showed a significant correlation between TTK and Th2 cells. KM and Cox analysis suggested that HCC patients with high TTK expression had a worse prognosis. TTK may play a pivotal role in HCC patients' response to TACE therapy and could be linked to the prognosis of these patients.

Elevated expression of WSB2 degrades p53 and activates the IGFBP3-AKT-mTOR-dependent pathway to drive hepatocellular carcinoma

Dysregulation of wild-type p53 turnover is a key cause of hepatocellular carcinoma (HCC), yet its mechanism remains poorly understood. Here, we report that WD repeat and SOCS box containing protein 2 (WSB2), an E3 ubiquitin ligase, is an independent adverse prognostic factor in HCC patients. WSB2 drives HCC tumorigenesis and lung metastasis in vitro and in vivo. Mechanistically, WSB2 is a new p53 destabilizer that promotes K48-linked p53 polyubiquitination at the Lys291 and Lys292 sites in HCC cells, leading to p53 proteasomal degradation. Degradation of p53 causes IGFBP3-dependent AKT/mTOR signaling activation. Furthermore, WSB2 was found to bind to the p53 tetramerization domain via its SOCS box domain. Targeting mTOR with everolimus, an oral drug, significantly blocked WSB2-triggered HCC tumorigenesis and metastasis in vivo. In clinical samples, high expression of WSB2 was associated with low wild-type p53 expression and high p-mTOR expression. These findings demonstrate that WSB2 is overexpressed and degrades wild-type p53 and then activates the IGFBP3-AKT/mTOR axis, leading to HCC tumorigenesis and lung metastasis, which indicates that targeting mTOR could be a new therapeutic strategy for HCC patients with high WSB2 expression and wild-type p53.