The miR-184-3p promotes rice black-streaked dwarf virus infection by suppressing Ken in Laodelphax striatellus (Fallén)

BACKGROUND

MicroRNAs (miRNAs) play a key role in various biological processes by influencing the translation of target messenger RNAs (mRNAs) through post-transcriptional regulation. The miR-184-3p has been identified as an abundant conserved miRNA in insects. However, less is known about its functions in insect-plant virus interactions.

RESULTS

The function of miR-184-3p in regulation of plant viral infection in insects was investigated using a rice black-streaked dwarf virus (RBSDV) and Laodelphax striatellus (Fallén) interaction system. We found that the expression of miR-184-3p increased in L. striatellus after RBSDV infection. Injection of miR-184-3p mimics increased RBSDV accumulation, while treatment with miR-184-3p antagomirs inhibits the viral accumulation in L. striatellus. Ken, a zinc finger protein, was identified as a target of miR-184-3p. Knockdown of Ken increased the virus accumulation and promoted RBSDV transmission by L. striatellus.

CONCLUSION

This study demonstrates that RBSDV infection induces the expression of miR-184-3p in its insect vector L. striatellus. The miR-184-3p targets Ken to promote RBSDV accumulation and transmission. These findings provide a new insight into the function of the miRNAs in regulating plant viral infection in its insect vector. © 2023 Society of Chemical Industry.

Intervening in hnRNPA2B1-mediated exosomal transfer of tumor-suppressive miR-184-3p for tumor microenvironment regulation and cancer therapy

BACKGROUND

Despite being a common malignant tumor, the molecular mechanism underlying the initiation and progression of triple-negative breast cancers (TNBCs) remain unclear. Tumor-associated macrophages (TAMs) are often polarized into a pro-tumor phenotype and are associated with a poor prognosis of TNBCs. Exosomes, important mediators of cell-cell communication, can be actively secreted by donor cells to reprogram recipient cells. The functions and molecular mechanisms of tumor cell-derived exosomes in TNBCs progression and TAMs reprogramming urgently need to be further explored.

RESULTS

We demonstrated that tumor cell-derived exosomes enriched with miR-184-3p were taken up by macrophages to inhibit JNK signaling pathway by targeting EGR1, thereby inducing M2 polarization of macrophages and synergistically promoting tumor progression. Nanoparticles loaded with oncogene c-Myc inhibitor JQ1 could suppress the polarization process by reducing Rac1-related exosome uptake by macrophage. More importantly, it was found for the first time that tumor-suppressive miR-184-3p was actively sorted into exosomes by binding to RNA-binding protein heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1), thus facilitating tumor cell proliferation and metastasis by relieving the inhibitory effect of miR-184-3p on Mastermind-like 1 (MAML1). Overexpressing miR-184-3p in tumor cells and simultaneously knocking down hnRNPA2B1 to block its secretion through exosomes could effectively inhibit tumor growth and metastasis.

CONCLUSIONS

Our study revealed that hnRNPA2B1-mediated exosomal transfer of tumor-suppressive miR-184-3p from breast cancer cells to macrophages was an important mediator of TNBCs progression, providing new insights into TNBCs pathogenesis and therapeutic strategies.