Exosomal miR-1910-3p promotes proliferation, metastasis, and autophagy of breast cancer cells by targeting MTMR3 and activating the NF-κB signaling pathway.

Exosomes are key mediators of intercellular communication and play a role in the pathogenesis and progression of cancer. Exosomes in circulating body fluids serve as molecular markers for cancer diagnosis. This study aimed to investigate the role of exosomal microRNA (miR)-1910-3p in breast cancer and determine its clinical diagnostic value. MiR-1910-3p promoted proliferation and migration of breast cancer cells in vitro and in vivo. In vitro, exosomes enriched in miR-1910-3p transferred miR-1910-3p to mammary epithelial cells and breast cancer cells, promoting proliferation and migration, inhibiting apoptosis, and inducing autophagy. In vivo, exosomes enriched in miR-1910-3p promoted the proliferation and migration of breast cancer cells. MiR-1910-3p downregulated myotubularin-related protein 3, activated the NF-κB and wnt/ß-catenin signaling pathway, and promoted breast cancer progression. Serum miR-1910-3p in exosomes was an effective diagnostic marker that improved the sensitivity of breast cancer diagnosis when used in combination with the traditional tumor marker CA153. In conclusion, breast cancer cell-derived exosomes promoted the growth, metastasis, and autophagy of breast cancer cells by transferring miR-1910-3p. MiR-1910-3p in serum exosomes may serve as a novel molecular marker for breast cancer diagnosis.

Caenorhabditis elegans eyes absent ortholog EYA-1 is required for stress resistance.

Eyes absent (Eya) is a highly conserved transcription cofactor and protein phosphatase that regulates multiple developmental processes throughout the metazoans. It is a dual function protein, working as a transcription factor in the nucleus and as a tyrosine phosphatase in the cytoplasm. In this study, we isolated EYA-1 of Caenorhabditis elegans, the only homolog of Eyes absent, and set up an effective feeding-based RNAi (RNA interference) against the gene. We found that knockdown of EYA-1 decreased heat and oxidative stress tolerance and accelerated the onset of paralysis mediated by Aß1-42 proteotoxicity and polyQ. Under heat stress (35°C), EYA-1 knockdown shortened the mean lifespan by 16.8%, which could be attributed to decrease in heat shock protein-16.2 (hsp-16.2) expression. Under oxidative stress, EYA-1 knockdown could shorten the mean lifespan by 18.7%, which could be attributed to intracellular ROS accumulation and the decrease of superoxide dismutase-3 (sod-3) protein expression. Moreover, EYA-1 knockdown animals also showed increased lipofuscin accumulation under oxidative stress. Further studies demonstrated that EYA-1 knockdown could not inhibit daf-16 nuclear accumulation in wild-type worms in response to stress. On the other hand, EYA-1 deficiency did not further reduce stress resistance of daf-16 mutants, which are stress sensitive. Quantitative real-time PCR results also showed that the expression of two daf-16 target genes, hsp-12.3 and sod-3, was downregulated in EYA-1 RNAi-treated worms under stress. All this evidence indicates EYA-1 is required for stress resistance of worms, and it might act downstream of daf-16 to regulate expression of stress resistance-associated genes.