Related Experiment Video
Updated: May 20, 2026
09:48
Monitoring of Nanodrug Accumulation in Murine Breast Cancer Metastases
Published on: August 23, 2024
MicroRNAs are exported from malignant cells in customized particles
Jaime Palma1, Sree C Yaddanapudi, Lucy Pigati
1Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.
Nucleic Acids Research
|July 10, 2012
Summary
Malignant cells release specific microRNAs (miRNAs) in larger vesicles called L-exosomes, unlike normal cells. This altered miRNA packaging could help detect cancer.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- MicroRNAs (miRNAs) are released from cells via proteins or microvesicles.
- Malignant transformation alters the composition of released miRNAs, but the mechanism of selectivity is unknown.
- Previous work showed that malignancy affects miRNA release versus retention within cells.
Purpose of the Study:
- To investigate the mechanisms by which malignant cells selectively export specific microRNAs (miRNAs).
- To characterize the structures packaging selectively released miRNAs compared to neutrally released miRNAs (n-miRNAs).
- To explore the potential of these miRNA-packaging alterations for cancer detection.
Main Methods:
- Separation and analysis of microvesicles released from breast cancer cells.
- Characterization of miRNA association with different types of microvesicles, including exosomes and nucleosomes.
- Comparison of microvesicle composition and miRNA distribution between malignant and normal cells.
Main Results:
- Selectively exported miRNAs in malignant cells are packaged in distinct structures, including exosomes and nucleosomes.
- Neutrally released miRNAs (n-miRNAs) in breast cancer cells associate with larger, unconventional exosomes (L-exosomes) enriched in CD44.
- Normal cells release all measured miRNAs within a single type of vesicle, unlike the heterogeneous release in cancer cells.
Conclusions:
- Malignant transformation significantly alters cellular pathways for specific miRNA export.
- Distinct microvesicle populations (L-exosomes) carry specific miRNAs in cancer cells.
- These miRNA-associated microvesicles represent potential biomarkers for detecting malignant cells.
Related Concept Videos
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...