Mitochondrial transcription factor B1 promotes the progression of hepatocellular carcinoma via enhancing aerobic glycolysis

Mapping in silico genetic networks of the KMT2D tumour suppressor gene to uncover novel functional associations and cancer cell vulnerabilities

BACKGROUND

Loss-of-function (LOF) alterations in tumour suppressor genes cannot be directly targeted. Approaches characterising gene function and vulnerabilities conferred by such mutations are required.

METHODS

Here, we computationally map genetic networks of KMT2D, a tumour suppressor gene frequently mutated in several cancer types. Using KMT2D loss-of-function (KMT2DLOF) mutations as a model, we illustrate the utility of in silico genetic networks in uncovering novel functional associations and vulnerabilities in cancer cells with LOF alterations affecting tumour suppressor genes.

RESULTS

We revealed genetic interactors with functions in histone modification, metabolism, and immune response and synthetic lethal (SL) candidates, including some encoding existing therapeutic targets. Notably, we predicted WRN as a novel SL interactor and, using recently available WRN inhibitor (HRO761 and VVD-133214) treatment response data, we observed that KMT2D mutational status significantly distinguishes treatment-sensitive MSI cell lines from treatment-insensitive MSI cell lines.

CONCLUSIONS

Our study thus illustrates how tumour suppressor gene LOF alterations can be exploited to reveal potentially targetable cancer cell vulnerabilities.

Mitochondrial RNA methylation in cancer

Mitochondria have a complete and independent genetic system with necessary biological energy for cancer occurrence and persistence. Mitochondrial RNA (mt-RNA) methylation, as a frontier in epigenetics, has linked to cancer progression with growing evidences. This review has comprehensively summarized detailed mechanisms of mt-RNA methylation in regulating cancer proliferation, metastasis, and immune infiltration from the mt-RNA methylation sites, biological significance, and its methyltransferases. The mt-RNA methylation also plays a very significant role via epigenetic crosstalk between nucleus and mitochondria. Importantly, the unique structures and functional characteristics of mt-RNA methyltransferases and the potential targeting treatment drugs for cancer are also analyzed. Revealing human mt-RNA methylation regulatory system and the relationship with cancer will contribute to identifying potential biomarkers and therapeutic targets for precise prevention, detection, intervention and treatment in the future.

The emergent role of mitochondrial RNA modifications in metabolic alterations

Mitochondrial epitranscriptomics refers to the modifications occurring in all the different RNA types of mitochondria. Although the number of mitochondrial RNA modifications is less than those in cytoplasm, substantial evidence indicates that they play a critical role in accurate protein synthesis. Recent evidence supported those modifications in mitochondrial RNAs also have crucial implications in mitochondrial-related diseases. In the light of current knowledge about the involvement, the association between mitochondrial RNA modifications and diseases arises from studies focusing on mutations in both mitochondrial and nuclear DNA genes encoding enzymes involved in such modifications. Here, we review the current evidence available for mitochondrial RNA modifications and their role in metabolic disorders, and we also explore the possibility of using them as promising targets for prevention and early detection. Finally, we discuss future directions of mitochondrial epitranscriptomics in these metabolic alterations, and how these RNA modifications may offer a new diagnostic and theragnostic avenue for preventive purposes. This article is categorized under: RNA Processing > RNA Editing and Modification.