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Biology subjects

Yu, A. T.

Publications and source records attributed to Yu, A. T..

3 recordsLinked to original sources

Lack of mRNA Methylation in Schwann Cells Results in Demyelination and Regenerative Failure

Schwann cells are essential for peripheral nerve myelination and regeneration. N6-methyladenosine (m6A) RNA methylation, regulated by methyltransferase-like 14 (Mettl14), is a critical post-transcriptional modification, but its role in Schwann cell biology remains unclear. Using a conditional knockout (cKO) mouse model, we investigated the impact of Mettl14-mediated m6A methylation on Schwann cells. Mice born with Schwann cell-specific genetic deletion of Mettl14 developed normally but starting in young adulthood exhibited progressive motor deficits, severe demyelination, and axonal degeneration, confirmed by behavioral assessments and histological analyses. Mettl14-deficient Schwann cells displayed impaired proliferation and mitochondrial dysfunction in vitro. Following sciatic nerve injury, Mettl14 cKO mice showed defective macrophage recruitment, slowed axonal degeneration, and impaired regeneration. These findings suggest that Mettl14-mediated m6A methylation is critical for Schwann cell maintenance but not development. Given that Mettl14 cKO mice developed a demyelinating polyneuropathy, it is possible that manipulation of m6A methylation in Schwann cells is a promising therapeutic strategy targeting peripheral nerve repair and myelination.

neuroscience↗

PHAROH lncRNA regulates c-Myc translation in hepatocellular carcinoma via sequestering TIAR

Hepatocellular carcinoma, the most common type of liver malignancy, is one of the most lethal forms of cancer. We identified a long non-coding RNA, Gm19705, that is over-expressed in hepatocellular carcinoma and mouse embryonic stem cells. We named this RNA Pluripotency and Hepatocyte Associated RNA Overexpressed in HCC, or PHAROH. Depletion of PHAROH impacts cell proliferation and migration, which can be rescued by ectopic expression of PHAROH. RNA-seq analysis of PHAROH knockouts revealed that a large number of genes with decreased expression contain a c-Myc motif in their promoter. C-MYC is decreased at the protein level, but not the mRNA level. RNA-antisense pulldown identified nucleolysin TIAR, a translational repressor, to bind to a 71-nt hairpin within PHAROH, sequestration of which increases c-MYC translation. In summary, our data suggest that PHAROH regulates c-MYC translation by sequestering TIAR and as such represents a potentially exciting diagnostic or therapeutic target in hepatocellular carcinoma.

cancer biology↗

MaTAR25 LncRNA Regulates the Tensin1 Gene to Impact Breast Cancer Progression

Misregulation of long non-coding RNA genes has been linked to a wide variety of cancer types. Here we report on Mammary Tumor Associated RNA 25 (MaTAR25), a nuclear enriched and chromatin associated lncRNA that plays a role in mammary tumor cell proliferation, migration, and invasion, both in vitro and in vivo. MaTAR25 functions by interacting with purine rich element binding protein B (PURB), and associating with a major downstream target gene Tensin 1 (Tns1) to regulate its expression in trans. Knockout of MaTAR25 results in down-regulation of Tns1 leading to a reorganization of the actin cytoskeleton, and a reduction of focal adhesions and microvilli. The human ortholog of MaTAR25, LINC01271, is upregulated with human breast cancer stage and metastasis. SIGNIFICANCELncRNAs have great potential to reveal new regulatory mechanisms of function as well as having exciting therapeutic capacity given their ease of being targeted by nucleic acid drugs. Our study of MaTAR25, and its human ortholog LINC01271, reveal an unexpected function of this lncRNA in breast cancer progression by regulating Tns1 gene expression, whose protein product is a critical component of focal adhesions linking signaling between the extracellular matrix and the actin cytoskeleton. We identified LINC01271 as the human ortholog of MaTAR25, and importantly, increased expression of LINC01271 is associated with poor patient prognosis and cancer metastasis. Our findings demonstrate that LINC01271 represents an exciting therapeutic target to alter breast cancer progression.

cancer biology↗