METTL3 and STAT3 form a positive feedback loop to promote cell metastasis in hepatocellular carcinoma

Emerging importance of m6A modification in liver cancer and its potential therapeutic role

Liver cancer refers to malignant tumors that form in the liver and is usually divided into several types, the most common of which is hepatocellular carcinoma (HCC), which originates in liver cells. Other rare types of liver cancer include intrahepatic cholangiocarcinoma (iCCA). m6A modification is a chemical modification of RNA that usually manifests as the addition of a methyl group to adenine in the RNA molecule to form N6-methyladenosine. This modification exerts a critical role in various biological processes by regulating the metabolism of RNA, affecting gene expression. Recent studies have shown that m6A modification is closely related to the occurrence and development of liver cancer, and m6A regulators can further participate in the pathogenesis of liver cancer by regulating the expression of key genes and the function of specific cells. In this review, we provided an overview of the latest advances in m6A modification in liver cancer research and explored in detail the specific functions of different m6A regulators. Meanwhile, we deeply analyzed the mechanisms and roles of m6A modification in liver cancer, aiming to provide novel insights and references for the search for potential therapeutic targets. Finally, we discussed the prospects and challenges of targeting m6A regulators in liver cancer therapy.

RNA modifications in the progression of liver diseases: from fatty liver to cancer

Non-alcoholic fatty liver disease (NAFLD) has emerged as a prominent global health concern associated with high risk of metabolic syndrome, and has impacted a substantial segment of the population. The disease spectrum ranges from simple fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma (HCC) and is increasingly becoming a prevalent indication for liver transplantation. The existing therapeutic options for NAFLD, NASH, and HCC are limited, underscoring the urgent need for innovative treatment strategies. Insights into gene expression, particularly RNA modifications such as N6 methyladenosine (m6A), hold promising avenues for interventions. These modifications play integral roles in RNA metabolism and cellular functions, encompassing the entire NAFLD-NASH-HCC progression. This review will encompass recent insights on diverse RNA modifications, including m6A, pseudouridine (ψ), N1-methyladenosine (m1A), and 5-methylcytidine (m5C) across various RNA species. It will uncover their significance in crucial aspects such as steatosis, inflammation, fibrosis, and tumorigenesis. Furthermore, prospective research directions and therapeutic implications will be explored, advancing our comprehensive understanding of the intricate interconnected nature of these pathological conditions.

Bushen Huoxue decotion-containing serum prevents chondrocyte pyroptosis in a m6A-dependent manner in facet joint osteoarthritis

BACKGROUND

Facet joint osteoarthritis (FJOA) is a common lumbar osteoarthritis characterized by degeneration of small joint cartilage. Bushen Huoxue decotion (BSHXD) has good therapeutic effects on OA. Our work aimed to further probe the pharmacological effects of BSHXD-containing serum (BSHXD-CS) on FJOA and define underlying the mechanisms invovled.

METHODS

To establish a FJOA cell model, primary rat chondrocytes were treated with LPS. The mRNA and protein expressions were assessed using qRT-PCR and western blot, respectively. The secretion levels of pro-inflammatory cytokines were measured by ELISA. Cell viability was determined by CCK8 assay. The global m6A level was detected by the kit, and NLRP3 mRNA m6A level was determined by Me-RIP assay. The molecular interactions were analyzed by RIP and RNA pull-down assays.

RESULTS

BSHXD-CS treatment relieved LPS-induced cell injury, inflammation, NLRP3 inflammasome and pyroptosis in chondrocytes (all p < 0.05). LPS-induced NLRP3 upregulation in chondrocytes was related to its high m6A modification level (p < 0.05). It was also observed that BSHXD-CS reduced LPS-induced m6A modification in chondrocytes via repressing STAT3 (all p < 0.05), suggesting BSHXD-CS could repress NLRP3 expression via m6A-dependent manner. Moreover, DAA, a m6A specific inhibitor, was proved to strengthen the protectively roles of BSHXD-CS on LPS-challenged pytoptosis (all p < 0.05).

CONCLUSION

BSHXD-CS inhibited NLRP3 inflammasome activation and pyroptosis in chondrocytes to repress OA progression by reducing RNA m6A modification.

Insight into the regulatory mechanism of m6A modification: From MAFLD to hepatocellular carcinoma

In recent years, there has been a significant increase in the incidence of metabolic-associated fatty liver disease (MAFLD), which has been attributed to the increasing prevalence of type 2 diabetes mellitus (T2DM) and obesity. MAFLD affects more than one-third of adults worldwide, making it the most prevalent liver disease globally. Moreover, MAFLD is considered a significant risk factor for hepatocellular carcinoma (HCC), with MAFLD-related HCC cases increasing. Approximately 1 in 6 HCC patients are believed to have MAFLD, and nearly 40 % of these HCC patients do not progress to cirrhosis, indicating direct transformation from MAFLD to HCC. N6-methyladenosine (m6A) is commonly distributed in eukaryotic mRNA and plays a crucial role in normal development and disease progression, particularly in tumors. Numerous studies have highlighted the close association between abnormal m6A modification and cellular metabolic alterations, underscoring its importance in the onset and progression of MAFLD. However, the specific impact of m6A modification on the progression of MAFLD to HCC remains unclear. Can targeting m6A effectively halt the progression of MAFLD-related HCC? In this review, we investigated the pivotal role of abnormal m6A modification in the transition from MAFLD to HCC, explored the potential of m6A modification as a therapeutic target for MAFLD-related HCC, and proposed possible directions for future investigations.

Investigating the molecular mechanism of Qizhu anticancer prescription in inhibiting hepatocellular carcinoma based on high-resolution mass spectrometry and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Of all primary liver cancer cases, hepatocellular carcinoma (HCC) accounts for about 90%. Most patients with HCC receive a diagnosis in the medium-to-late stages or with chronic liver disease, have lost the opportunity for radical treatment, such as surgical resection, and their 5-year survival rate is low. Qizhu Anticancer Prescription (QZACP) is an empirical formula composed of traditional Chinese herbs that can clinically relieve HCC symptoms, inhibit the progression of HCC, reduce recurrence rate, and prolong survival; however, its exact mode of action remains unknown.

AIM OF THE STUDY

This study's purpose was to investigate the mode of action of QZACP in the prevention and treatment of HCC.

MATERIALS AND METHODS

Initially, drug components in the QZACP decoction were analyzed using high-resolution mass spectrometry. A subcutaneous tumor xenograft model in nude mice was constructed to further analyze the active components of QZACP that had entered tumor tissues through oral administration. Potential targets of QZACP in the prevention and treatment of HCC were identified and then confirmed in vivo via network pharmacology and molecular docking. In addition, regulatory effects of QZACP on HCC cell proliferation and the cell cycle were detected using a CCK-8 assay and flow cytometry.

RESULTS

High-resolution mass spectrometry revealed that the QZACP decoction contained deacetyl asperulosidic acid methyl ester (DAAME), paeoniflorin, calycosin-7-glucoside, liquiritin, glycyrrhizic acid, astragaloside IV, saikosaponin A, curdione, and atractylenolide II. In nude mice, QZACP could effectively inhibit the growth of subcutaneous tumors, where DAAME, paeoniflorin, liquiritin, and glycyrrhizic acid could enter liver cancer tissues after oral administration. Among these, DAAME was the most highly expressed in HCC tissues and may be an important active component of QZACP for inhibiting HCC. Utilizing network pharmacology, the targets of action of these four drug components were identified. After verification using western blotting, STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2 were identified as targets of QZACP inhibition in HCC. In vitro experiments revealed that QZACP inhibited the proliferation of HCC cells while inducing G0/G1 phase cell cycle arrest. In vivo experiments demonstrated that DAAME significantly inhibited HCC growth. After intersection of the 24 DAAME targets predicted using network pharmacology with the 435 HCC disease targets, only CA9 was identified as a DAAME-HCC crossover target. Molecular docking results revealed that the binding site of DAAME and CA9 had good stereo-complementarity with a docking score of -8.1 kcal/mol. Western blotting and immunohistochemical results also confirmed that DAAME significantly decreased CA9 protein expression in HCC.

CONCLUSIONS

QZACP inhibits HCC by reducing the expression of STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2. DAAME may be an important active component of QZACP for the prevention and treatment of HCC, inhibiting it by targeting the expression of CA9.

Elevated WTAP promotes hyperinflammation by increasing m6A modification in inflammatory disease models

Emerging evidence has linked the dysregulation of N6-methyladenosine (m6A) modification to inflammation and inflammatory diseases, but the underlying mechanism still needs investigation. Here, we found that high levels of m6A modification in a variety of hyperinflammatory states are p65-dependent because Wilms tumor 1-associated protein (WTAP), a key component of the "writer" complex, is transcriptionally regulated by p65, and its overexpression can lead to increased levels of m6A modification. Mechanistically, upregulated WTAP is more prone to phase separation to facilitate the aggregation of the writer complex to nuclear speckles and the deposition of m6A marks on transcriptionally active inflammatory transcripts, thereby accelerating the proinflammatory response. Further, a myeloid deficiency in WTAP attenuates the severity of LPS-induced sepsis and DSS-induced IBD. Thus, the proinflammatory effect of WTAP is a general risk-increasing mechanism, and interrupting the assembly of the m6A writer complex to reduce the global m6A levels by targeting the phase separation of WTAP may be a potential and promising therapeutic strategy for alleviating hyperinflammation.

Emerging function of main RNA methylation modifications in the immune microenvironment of digestive system tumors

Digestive system tumors have been reported in more than 25% of all cancer cases worldwide, bringing a huge burden on the healthcare system. RNA methylation modification-an important post-transcriptional modification-has become an active research area in gene regulation. It is a dynamic and reversible process involving several enzymes, such as methyltransferases, demethylases, and methylation reader proteins. This review provides insights into the role of three major methylation modifications, namely m6A, m5C, and m1A, in the development of digestive system tumors, specifically in the development of tumor immune microenvironment (TIME) of these malignancies. Abnormal methylation modification affects immunosuppression and antitumor immune response by regulating the recruitment of immune cells and the release of immune factors. Understanding the mechanisms by which RNA methylation regulates digestive system tumors will be helpful in exploring new therapeutic targets.

Non-coding RNA methylation modifications in hepatocellular carcinoma: interactions and potential implications

RNA methylation modification plays a crucial role as an epigenetic regulator in the oncogenesis of hepatocellular carcinoma (HCC). Numerous studies have investigated the molecular mechanisms underlying the methylation of protein-coding RNAs in the progression of HCC. Beyond their impact on mRNA, methylation modifications also influence the biological functions of non-coding RNAs (ncRNAs). Here, we present an advanced and comprehensive overview of the interplay between methylation modifications and ncRNAs in HCC, with a specific focus on their potential implications for the tumor immune microenvironment. Moreover, we summarize promising therapeutic targets for HCC based on methylation-related proteins. In the future, a more profound investigation is warranted to elucidate the effects of ncRNA methylation modifications on HCC pathogenesis and devise valuable intervention strategies. Video Abstract.