m6A RNA methylation regulators predict prognosis and indicate characteristics of tumour microenvironment infiltration in acute myeloid leukaemia

Betulinic acid regulates tumor-associated macrophage M2 polarization and plays a role in inhibiting the liver cancer progression

OBJECTIVE

To investigate the regulatory role and mechanism of betulinic acid (BET) in tumor-associated M2 macrophage polarization.

METHODS

For in vitro experiments, RAW246.7 and J774A.1 cells were used, and differentiation of M2 macrophages was induced using recombinant interleukin-4/13. The levels of M2 cell marker cytokines were measured, and the proportion of F4/80+CD206+ cells was evaluated using flow cytometry. Furthermore, STAT6 signaling was detected, and H22 and RAW246.7 cells were cocultured to assess the effect of BET on M2 macrophage polarization. Changes in the malignant behavior of H22 cells after coculturing were observed and a tumor-bearing mouse model was constructed to determine CD206 cell infiltration after BET intervention.

RESULTS

In vitro experiments showed that BET inhibited M2 macrophage polarization and phospho-STAT6 signal modification. Moreover, the ability to promote the malignant behavior of H22 cells was reduced in BET-treated M2 macrophages. Furthermore, in vivo experiments indicated that BET decreased M2 macrophage polarization and infiltration in the microenvironment of liver cancer. BET was noted to predominantly bind to the STAT6 site to inhibit STAT6 phosphorylation.

CONCLUSION

BET bound chiefly to STAT6 to inhibit STAT6 phosphorylation and decrease M2 polarization in the microenvironment of liver cancer. These findings suggest that BET exerts an antitumor effect by modulating M2 macrophage function.

Understanding the Epitranscriptome for Avant-Garde Brain Tumour Diagnostics

RNA modifications are diverse, dynamic, and reversible transcript alterations rapidly gaining attention due to their newly defined RNA regulatory roles in cellular pathways and pathogenic mechanisms. The exciting emerging field of 'epitranscriptomics' is predominantly centred on studying the most abundant mRNA modification, N6-methyladenine (m⁶A). The m⁶A mark, similar to many other RNA modifications, is strictly regulated by so-called 'writer', 'reader', and 'eraser' protein species. The abundance of genes coding for the expression of these regulator proteins and m⁶A levels shows great potential as diagnostic and predictive tools across several cancer fields. This review explores our current understanding of RNA modifications in glioma biology and the potential of epitranscriptomics to develop new diagnostic and predictive classification tools that can stratify these highly complex and heterogeneous brain tumours.