Kinesin family member 23 exerts a protumor function in breast cancer via stimulation of the Wnt/β-catenin pathway

Acetylation in pathogenesis: Revealing emerging mechanisms and therapeutic prospects

Protein acetylation modifications play a central and pivotal role in a myriad of biological processes, spanning cellular metabolism, proliferation, differentiation, apoptosis, and beyond, by effectively reshaping protein structure and function. The metabolic state of cells is intricately connected to epigenetic modifications, which in turn influence chromatin status and gene expression patterns. Notably, pathological alterations in protein acetylation modifications are frequently observed in diseases such as metabolic syndrome, cardiovascular disorders, and cancer. Such abnormalities can result in altered protein properties and loss of function, which are closely associated with developing and progressing related diseases. In recent years, the advancement of precision medicine has highlighted the potential value of protein acetylation in disease diagnosis, treatment, and prevention. This review includes provocative and thought-provoking papers outlining recent breakthroughs in acetylation modifications as they relate to cardiovascular disease, mitochondrial metabolic regulation, liver health, neurological health, obesity, diabetes, and cancer. Additionally, it covers the molecular mechanisms and research challenges in understanding the role of acetylation in disease regulation. By summarizing novel targets and prognostic markers for the treatment of related diseases, we aim to contribute to the field. Furthermore, we discuss current hot topics in acetylation research related to health regulation, including N4-acetylcytidine and liquid-liquid phase separation. The primary objective of this review is to provide insights into the functional diversity and underlying mechanisms by which acetylation regulates proteins in disease contexts.

FOXM1 augments sorafenib resistance and promotes progression of hepatocellular carcinoma by epigenetically activating KIF23 expression

Sorafenib has been used to enhance the survival outcome of hepatocellular carcinoma (HCC) patients. But, occurrence resistance to sorafenib subtracts from its therapeutic benefits. Herein, we identified that FOXM1 was markedly upregulated in both tumor samples and sorafenib-resistant HCC tissues. We also demonstrated that patients with decreased FOXM1 expression had longer overall survival (OS) and progression-free survival (PFS) in the cohort of sorafenib-treated patients. For HCC cells resistant to sorafenib, the IC50 value of sorafenib and the expression of FOXM1 were increased. In addition, Downregulation of FOXM1 expression alleviated the occurrence of resistance to sorafenib and reduced the proliferative potential and viability of HCC cells. Mechanically, the suppression of the FOXM1 gene resulted in the downregulation of KIF23 levels. Moreover, downregulation of FOXM1 expression reduced the levels of RNA polymerase II (RNA pol II) and histone H3 lysine 27 acetylation (H3K27ac) on the KIF23 promoter, further epigenetically silencing the production of KIF23. More intriguingly, our results similarly revealed that FDI-6, a specific inhibitor of FOXM1, suppressed the proliferation of HCC cells resistant to sorafenib, as well as upregulation of FOXM1 or KIF23 abolished this effect. In addition, we found that FDI-6 combined with sorafenib significantly improved the therapeutic effect of sorafenib. Collectively, the present results revealed that FOXM augments sorafenib resistance and enhances HCC progression by upregulating KIF23 expression via an epigenetic mechanism, and targeting FOXM1 can be an effective treatment for HCC.

Acetyltransferase NAT10 regulates the Wnt/β-catenin signaling pathway to promote colorectal cancer progression via ac4C acetylation of KIF23 mRNA

BACKGROUND

N⁴-acetylcytidine (ac⁴C) as a significant RNA modification has been reported to maintain the stability of mRNA and to regulate the translation process. However, the roles of both ac⁴C and its 'writer' protein N-acetyltransferase 10 (NAT10) played in the disease especially colorectal cancer (CRC) are unclear. At this point, we discover the underlying mechanism of NAT10 modulating the progression of CRC via mRNA ac⁴C modification.

METHODS

The clinical significance of NAT10 was explored based on the TCGA and GEO data sets and the 80 CRC patients cohort of our hospital. qRT-PCR, dot blot, WB, and IHC were performed to detect the level of NAT10 and ac⁴C modification in CRC tissues and matched adjacent tissues. CCK-8, colony formation, transwell assay, mouse xenograft, and other in vivo and in vitro experiments were conducted to probe the biological functions of NAT10. The potential mechanisms of NAT10 in CRC were clarified by RNA-seq, RIP-seq, acRIP-seq, luciferase reporter assays, etc. RESULTS: The levels of NAT10 and ac⁴C modification were significantly upregulated. Also, the high expression of NAT10 had important clinical values like poor prognosis, lymph node metastasis, distant metastasis, etc. Furthermore, the in vitro experiments showed that NAT10 could inhibit apoptosis and enhance the proliferation, migration, and invasion of CRC cells and also arrest them in the G2/M phase. The in vivo experiments discovered that NAT10 could promote tumor growth and liver/lung metastasis. In terms of mechanism, NAT10 could mediate the stability of KIF23 mRNA by binding to its mRNA 3'UTR region and up-regulating its mRNA ac⁴c modification. And then the protein level of KIF23 was elevated to activate the Wnt/β-catenin pathway and more β-catenin was transported into the nucleus which led to the CRC progression. Besides, the inhibitor of NAT10, remodelin, was applied in vitro and vivo which showed an inhibitory effect on the CRC cells.

CONCLUSIONS

NAT10 promotes the CRC progression through the NAT10/KIF23/GSK-3β/β-catenin axis and its expression is mediated by GSK-3β which forms a feedback loop. Our findings provide a potential prognosis or therapeutic target for CRC and remodelin deserves more attention.

KIF23 promotes autophagy-induced imatinib resistance in chronic myeloid leukaemia through activating Wnt/β-catenin pathway

Imatinib, an inhibitor of tyrosine kinase, shows remarkable efficacy in chronic myeloid leukaemia (CML). Autophagy protects tumour cells against chemotherapeutic stimulation and contributes to imatinib resistance in CML. Kinesin family member 23 (KIF23) is involved in cytokinesis and associated with autophagy. The role of KIF23 in autophagy-induced imatinib resistance in CML was investigated. First, to induce drug resistance, CML cells were exposed to increasing concentrations of imatinib. The concentration of imatinib resistance in CML cells was screened through upregulation of 50% inhibitory concentration (IC₅₀ ) values. KIF23 was elevated in imatinib-resistant tissues and cells of CML. Second, knockdown of KIF23 reduced IC₅₀ values of imatinib-resistant CML cells to imatinib. Moreover, silence of KIF23 also suppressed cell proliferation and promoted apoptosis of imatinib-resistant CML cells. Third, immunofluorescence analysis showed that the number of LC3 bright spots in imatinib-resistant CML cells was reduced by silence of KIF23. Knockdown of KIF23 upregulated p62 expression and downregulated the expression ratio of LC3-II to LC3-I in imatinib-resistant CML cells. Last, silence of KIF23 decreased nuclear β-catenin and increased cytoplasmic β-catenin in imatinib-resistant CML cells. Activator of Wnt/β-catenin attenuated KIF23 silence-induced increase of apoptosis and decrease of autophagy in imatinib-resistant CML cells. In conclusion, loss of KIF23 repressed autophagy-induced imatinib resistance in CML cells through inactivation of Wnt/β-catenin pathway.

DEAD-Box RNA Helicases DDX3X and DDX5 as Oncogenes or Oncosuppressors: A Network Perspective

Simple Summary

The transformation of a normal cell into a cancerous one is caused by the deregulation of different metabolic pathways, involving a complex network of protein–protein interactions. The cellular enzymes DDX3X and DDX5 play important roles in the maintenance of normal cell metabolism, but their deregulation can accelerate tumor transformation. Both DDX3X and DDX5 interact with hundreds of different cellular proteins, and depending on the specific pathways in which they are involved, both proteins can either act as suppressors of cancer or as oncogenes. In this review, we summarize the current knowledge about the roles of DDX3X and DDX5 in different tumors. In addition, we present a list of interacting proteins and discuss the possible contribution of some of these protein–protein interactions in determining the roles of DDX3X and DDX5 in the process of cancer proliferation, also suggesting novel hypotheses for future studies.

Abstract

RNA helicases of the DEAD-box family are involved in several metabolic pathways, from transcription and translation to cell proliferation, innate immunity and stress response. Given their multiple roles, it is not surprising that their deregulation or mutation is linked to different pathological conditions, including cancer. However, while in some cases the loss of function of a given DEAD-box helicase promotes tumor transformation, indicating an oncosuppressive role, in other contexts the overexpression of the same enzyme favors cancer progression, thus acting as a typical oncogene. The roles of two well-characterized members of this family, DDX3X and DDX5, as both oncogenes and oncosuppressors have been documented in several cancer types. Understanding the interplay of the different cellular contexts, as defined by the molecular interaction networks of DDX3X and DDX5 in different tumors, with the cancer-specific roles played by these proteins could help to explain their apparently conflicting roles as cancer drivers or suppressors.