Limits...
Selective release of microRNA species from normal and malignant mammary epithelial cells.

Pigati L, Yaddanapudi SC, Iyengar R, Kim DJ, Hearn SA, Danforth D, Hastings ML, Duelli DM - PLoS ONE (2010)

Bottom Line: Here we report that released miRNAs do not necessarily reflect the abundance of miRNA in the cell of origin.Our findings suggest the existence of a cellular selection mechanism for miRNA release and indicate that the extracellular and cellular miRNA profiles differ.This selective release of miRNAs is an important consideration for the identification of circulating miRNAs as biomarkers of disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.

ABSTRACT
MicroRNAs (miRNAs) in body fluids are candidate diagnostics for a variety of conditions and diseases, including breast cancer. One premise for using extracellular miRNAs to diagnose disease is the notion that the abundance of the miRNAs in body fluids reflects their abundance in the abnormal cells causing the disease. As a result, the search for such diagnostics in body fluids has focused on miRNAs that are abundant in the cells of origin. Here we report that released miRNAs do not necessarily reflect the abundance of miRNA in the cell of origin. We find that release of miRNAs from cells into blood, milk and ductal fluids is selective and that the selection of released miRNAs may correlate with malignancy. In particular, the bulk of miR-451 and miR-1246 produced by malignant mammary epithelial cells was released, but the majority of these miRNAs produced by non-malignant mammary epithelial cells was retained. Our findings suggest the existence of a cellular selection mechanism for miRNA release and indicate that the extracellular and cellular miRNA profiles differ. This selective release of miRNAs is an important consideration for the identification of circulating miRNAs as biomarkers of disease.

Show MeSH

Related in: MedlinePlus

Extracellular Mammary Epithelial Signature miRNAs are Present in Body Fluids.A. Abundance of indicated miRNAs quantitated using qRT-PCR from the plasma of mice injected subcutaneously with indicated breast-cancer cell lines as shown in Figure S3, and normalized to miR-22, a microRNA of murine blood, but not found in the conditioned media of these cancer cell lines. B. Plot of quantities for indicated miRNAs in 3 samples each of human milk (milk), cell-free ductal lavages of breast cancer patients (lavages), extracellular (MCF7 X) and intracellular MCF7 (MCF7 C) preparations, as quantitated by the stem-loop-primer qRT-PCR approach. A: lavages of a patient with atypical ductal hyperplasia; B and C: lavages of patients with less severe epithelial hyperplasia. Inset: plot of ratios for miR-451 and miR-720. Dot shadings correspond to the same samples as labeled in Figure 6B. C. Additional miRNAs quantified in ductal lavages using the linker-ligation qRT-PCR method.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2958125&req=5

pone-0013515-g006: Extracellular Mammary Epithelial Signature miRNAs are Present in Body Fluids.A. Abundance of indicated miRNAs quantitated using qRT-PCR from the plasma of mice injected subcutaneously with indicated breast-cancer cell lines as shown in Figure S3, and normalized to miR-22, a microRNA of murine blood, but not found in the conditioned media of these cancer cell lines. B. Plot of quantities for indicated miRNAs in 3 samples each of human milk (milk), cell-free ductal lavages of breast cancer patients (lavages), extracellular (MCF7 X) and intracellular MCF7 (MCF7 C) preparations, as quantitated by the stem-loop-primer qRT-PCR approach. A: lavages of a patient with atypical ductal hyperplasia; B and C: lavages of patients with less severe epithelial hyperplasia. Inset: plot of ratios for miR-451 and miR-720. Dot shadings correspond to the same samples as labeled in Figure 6B. C. Additional miRNAs quantified in ductal lavages using the linker-ligation qRT-PCR method.

Mentions: We assessed if xenografted MCF7 and MDA-MB-231 cells also release miRNAs into the murine blood circulation (Figure S3). To do so, we normalized the measured miRNA levels to miR-22, a miRNA that we did not find to be released from breast cancer cells, but which was present in mouse blood. We found that xenografting either cell line resulted in an increase in plasma levels of miR-451, miR-720, miR-99a (Figure 6A). In addition, plasma of mice injected with MCF7 cells, but not plasma of uninjected littermates had detectable amounts of miR-1246 (Figure S3). Therefore we conclude that breast cancer cell lines release signature miR-451 and miR-1246 into the blood.


Selective release of microRNA species from normal and malignant mammary epithelial cells.

Pigati L, Yaddanapudi SC, Iyengar R, Kim DJ, Hearn SA, Danforth D, Hastings ML, Duelli DM - PLoS ONE (2010)

Extracellular Mammary Epithelial Signature miRNAs are Present in Body Fluids.A. Abundance of indicated miRNAs quantitated using qRT-PCR from the plasma of mice injected subcutaneously with indicated breast-cancer cell lines as shown in Figure S3, and normalized to miR-22, a microRNA of murine blood, but not found in the conditioned media of these cancer cell lines. B. Plot of quantities for indicated miRNAs in 3 samples each of human milk (milk), cell-free ductal lavages of breast cancer patients (lavages), extracellular (MCF7 X) and intracellular MCF7 (MCF7 C) preparations, as quantitated by the stem-loop-primer qRT-PCR approach. A: lavages of a patient with atypical ductal hyperplasia; B and C: lavages of patients with less severe epithelial hyperplasia. Inset: plot of ratios for miR-451 and miR-720. Dot shadings correspond to the same samples as labeled in Figure 6B. C. Additional miRNAs quantified in ductal lavages using the linker-ligation qRT-PCR method.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2958125&req=5

pone-0013515-g006: Extracellular Mammary Epithelial Signature miRNAs are Present in Body Fluids.A. Abundance of indicated miRNAs quantitated using qRT-PCR from the plasma of mice injected subcutaneously with indicated breast-cancer cell lines as shown in Figure S3, and normalized to miR-22, a microRNA of murine blood, but not found in the conditioned media of these cancer cell lines. B. Plot of quantities for indicated miRNAs in 3 samples each of human milk (milk), cell-free ductal lavages of breast cancer patients (lavages), extracellular (MCF7 X) and intracellular MCF7 (MCF7 C) preparations, as quantitated by the stem-loop-primer qRT-PCR approach. A: lavages of a patient with atypical ductal hyperplasia; B and C: lavages of patients with less severe epithelial hyperplasia. Inset: plot of ratios for miR-451 and miR-720. Dot shadings correspond to the same samples as labeled in Figure 6B. C. Additional miRNAs quantified in ductal lavages using the linker-ligation qRT-PCR method.
Mentions: We assessed if xenografted MCF7 and MDA-MB-231 cells also release miRNAs into the murine blood circulation (Figure S3). To do so, we normalized the measured miRNA levels to miR-22, a miRNA that we did not find to be released from breast cancer cells, but which was present in mouse blood. We found that xenografting either cell line resulted in an increase in plasma levels of miR-451, miR-720, miR-99a (Figure 6A). In addition, plasma of mice injected with MCF7 cells, but not plasma of uninjected littermates had detectable amounts of miR-1246 (Figure S3). Therefore we conclude that breast cancer cell lines release signature miR-451 and miR-1246 into the blood.

Bottom Line: Here we report that released miRNAs do not necessarily reflect the abundance of miRNA in the cell of origin.Our findings suggest the existence of a cellular selection mechanism for miRNA release and indicate that the extracellular and cellular miRNA profiles differ.This selective release of miRNAs is an important consideration for the identification of circulating miRNAs as biomarkers of disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.

ABSTRACT
MicroRNAs (miRNAs) in body fluids are candidate diagnostics for a variety of conditions and diseases, including breast cancer. One premise for using extracellular miRNAs to diagnose disease is the notion that the abundance of the miRNAs in body fluids reflects their abundance in the abnormal cells causing the disease. As a result, the search for such diagnostics in body fluids has focused on miRNAs that are abundant in the cells of origin. Here we report that released miRNAs do not necessarily reflect the abundance of miRNA in the cell of origin. We find that release of miRNAs from cells into blood, milk and ductal fluids is selective and that the selection of released miRNAs may correlate with malignancy. In particular, the bulk of miR-451 and miR-1246 produced by malignant mammary epithelial cells was released, but the majority of these miRNAs produced by non-malignant mammary epithelial cells was retained. Our findings suggest the existence of a cellular selection mechanism for miRNA release and indicate that the extracellular and cellular miRNA profiles differ. This selective release of miRNAs is an important consideration for the identification of circulating miRNAs as biomarkers of disease.

Show MeSH
Related in: MedlinePlus