RBX1 regulates PKM alternative splicing to facilitate anaplastic thyroid carcinoma metastasis and aerobic glycolysis by destroying the SMAR1/HDAC6 complex

RING box protein-1 promotes the metastasis of cervical cancer through regulating matrix metalloproteinases via PI3K/AKT signaling pathway

Cervical cancer (CC) remains a leading cause of cancer mortality amongst females worldwide. Some of the CC patients may experience early metastases of the primary tumor, however the underlying mechanism remains unclear. Aberrant expression of RING box protein-1 (RBX1), a subunit in the E3 ubiquitin ligase family, has been reported in several cancer types. Nevertheless, little is known regarding the role of RBX1 in the metastasis of CC patients. In this study, we examined the expression of RBX1 from 90 biopsies of CC patients, and found a significantly increased expression of RBX1 in the tumor tissues compared to the normal tissues. Notably, the abundance of RBX1 in the CC patients with metastasis was higher than their counterparts without metastasis, suggesting that RBX1 may play a significant role in the modulation of CC metastasis. Furthermore, by using Hela cells as a model of CC in vitro, we demonstrated that ectopic over-expression of RBX1 could significantly promote the migration and invasion of Hela cells, whereas knockdown of RBX1 could remarkably suppress the migration and invasion of Hela cells. Mechanistically, the regulatory effect of RBX1 on cell metastasis was associated with changes in matrix metalloproteinases (MMP3 and MMP9) and altered activity of PI3K/AKT signaling. In conclusion, this study highlighted RBX1 as a novel target that can promote the metastasis of Hela cells in vitro, which may contribute to the development of alternative therapeutic options for CC patients.

HNRNPC modulates PKM alternative splicing via m6A methylation, upregulating PKM2 expression to promote aerobic glycolysis in papillary thyroid carcinoma and drive malignant progression

The heterogeneous nuclear ribonucleoprotein C (HNRNPC) plays a crucial role in tumorigenesis, yet its role in papillary thyroid carcinoma (PTC) remains elusive. Herein, we elucidated the function and molecular mechanism of HNRNPC in PTC tumorigenesis and progression. Our study unveiled a significant upregulation of HNRNPC in PTC, and knockdown of HNRNPC markedly inhibited the proliferation, invasion, and metastasis of BCPAP cells. Furthermore, HNRNPC modulated PKM alternative splicing in BCPAP cells primarily through m6A modification. Additionally, by upregulating PKM2 expression, HNRNPC promoted aerobic glycolysis in BCPAP cells, thereby facilitating malignant progression in PTC. In summary, our findings demonstrate that HNRNPC regulates PKM alternative splicing through m6A methylation modification and promotes the proliferation, invasion and metastasis of PTC through glucose metabolism pathways mediated by PKM2. These discoveries provide new biomarkers for screening and diagnosing PTC patients and offer novel therapeutic targets for personalized treatment strategies.

Chrysophanol inhibits of colorectal cancer cell motility and energy metabolism by targeting the KITENIN/ErbB4 oncogenic complex

BACKGROUND

Expression of the KITENIN/ErbB4 oncogenic complex is associated with metastasis of colorectal cancer to distant organs and lymph nodes and is linked with poor prognosis and poor survival.

METHODS

Here, we used in vitro and in silico methods to test the ability of chrysophanol, a molecule of natural origin, to suppress the progression of colorectal cancer by targeting the KITENIN/ErbB4 complex.

RESULTS

Chrysophanol binds to ErbB4, disrupting the ErbB4/KITENIN complex and causing autophagic degradation of KITENIN. We demonstrated that chrysophanol binds to ErbB4 according to a molecular docking model. Chrysophanol reversed KITENIN-mediated effects on cell motility, aerobic glycolysis, and expression of downstream effector genes. Moreover, under conditions of KITENIN overexpression, chrysophanol suppressed the production of onco-metabolites.

CONCLUSION

Chrysophanol suppresses oncogenic activities by targeting the KITENIN/ErbB4 complex.

Ubiquitin-modifying enzymes in thyroid cancer：Mechanisms and functions

Thyroid cancer is the most common malignant tumor of the endocrine system, and evidence suggests that post-translational modifications (PTMs) and epigenetic alterations play an important role in its development. Recently, there has been increasing evidence linking dysregulation of ubiquitinating enzymes and deubiquitinases with thyroid cancer. This review aims to summarize our current understanding of the role of ubiquitination-modifying enzymes in thyroid cancer, including their regulation of oncogenic pathways and oncogenic proteins. The role of ubiquitination-modifying enzymes in thyroid cancer development and progression requires further study, which will provide new insights into thyroid cancer prevention, treatment and the development of novel agents.

Ubiquitin-specific protease 54 regulates GLUT1-mediated aerobic glycolysis to inhibit lung adenocarcinoma progression by modifying p53 degradation

Lung adenocarcinoma (LUAD) is one of the most prevalent types of cancer. Ubiquitination is crucial in modulating cell proliferation and aerobic glycolysis in cancer. The frequency of TP53 mutations in LUAD is approximately 50%. Currently, therapeutic targets for wild-type (WT) p53-expressing LUAD are limited. In the present study, we systemically explored the expression of ubiquitin-specific protease genes using public datasets. Then, we focused on ubiquitin-specific protease 54 (USP54), and explored its prognostic significance in LUAD patients using public datasets, analyses, and an independent cohort from our center. We found that the expression of USP54 was lower in LUAD tissues compared with that in the paracancerous tissues. Low USP54 expression levels were linked to a malignant phenotype and worse survival in patients with LUAD. The results of functional experiments revealed that up-regulation of USP54 suppressed LUAD cell proliferation in vivo and in vitro. USP54 directly interacted with p53 protein and the levels of ubiquitinated p53 were inversely related to USP54 levels, consistent with a role of USP54 in deubiquitinating p53 in p53-WT LUAD cells. Moreover, up-regulation of the USP54 expression inhibited aerobic glycolysis in LUAD cells. Importantly, we confirmed that USP54 inhibited aerobic glycolysis and the growth of tumor cells by a p53-mediated decrease in glucose transporter 1 (GLUT1) expression in p53-WT LUAD cells. Altogether, we determined a novel mechanism of survival in the p53-WT LUAD cells to endure the malnourished tumor microenvironment and provided insights into the role of USP54 in the adaptation of p53-WT LUAD cells to metabolic stress.

ZNF471 Interacts with BANP to Reduce Tumour Malignancy by Inactivating PI3K/AKT/mTOR Signalling but is Frequently Silenced by Aberrant Promoter Methylation in Renal Cell Carcinoma

Background: Renal cell carcinoma (RCC) is one of the most common malignant tumours of the urinary system. However, the aetiology and pathogenesis of RCC remain unclear. The C2H2 zinc finger protein (ZNF) family is the largest transcriptional regulatory factor family found in mammals, and Krüppel-associated box domain-containing zinc finger proteins (KRAB-ZFPs) constitute the largest subfamily of the C2H2 zinc finger protein family and play an important role in the occurrence and development of tumours. The aim of this study was to explore the role of abnormal methylation of ZNF471 in the development of renal carcinoma. Methods: In this study, we first used the TCGA and EWAS Data Hub databases to analyse the expression and methylation levels of ZNF471 in renal carcinoma tissues and adjacent normal tissues. Second, we collected samples of renal cancer and adjacent normal tissues at Peking University First Hospital to investigate the expression and methylation level of ZNF471 in renal cancer tissues and the relationships between these levels and the clinicopathological features and prognosis of patients with renal cancer. Next, we investigated the effects of ZNF471 on the proliferation, metastasis, cell cycle progression, and apoptosis of renal cell carcinoma cells by cell biology experiments. Finally, we elucidated the underlying molecular mechanisms of ZNF471 in renal cell carcinoma by transcriptome sequencing, bioinformatics analysis and molecular biology experiments. Results: The expression of ZNF471 in renal carcinoma tissues and cell lines was significantly lower than that in adjacent normal tissues and cell lines due to abnormal promoter CpG methylation. Furthermore, the expression of ZNF471 in renal carcinoma tissues was negatively correlated with tumour stage and grade in patients with renal carcinoma. The results of the cell biology experiments showed that ZNF471 could significantly inhibit the proliferation, migration and cell cycle progression of renal cell carcinoma cells and promote apoptosis in these cells. In addition, ZNF471 could interact with BANP and suppress the malignant phenotype of RCC by inactivating the PI3K/AKT/mTOR signalling pathway. Conclusions: As an important tumour suppressor, ZNF471 can interact with BANP in renal cancer cells and inhibit the activation of the PI3K/AKT/mTOR signalling pathway, thereby inhibiting the occurrence and development of renal cancer.