Circulating miR-378 in plasma: a reliable, haemolysis-independent biomarker for colorectal cancer.
Author(s): Zanutto S, Pizzamiglio S, Ghilotti M, Bertan C, Ravagnani F, Perrone F, Leo E, Pilotti S, Verderio P, Gariboldi M, Pierotti MA
Publication: Br J Cancer, 2014, Vol. 110, Page 1001-7
PubMed ID: 24423916 PubMed Review Paper? No
Purpose of Paper
The purpose of this paper was to determine the effects of hemolysis and patient surgery on levels of microRNA (miRNA, miR) differentially expressed in plasma from colorectal cancer (CRC) patients and healthy controls.
Conclusion of Paper
Regardless of the inclusion of hemolyzed specimens, miR-378 levels were able to discriminate between the plasma from healthy individuals and those with CRC and between plasma obtained pre-surgery and 4-6 months post-surgery. Conversely, the ability of to discriminate plasma from healthy and CDC patients using miR-21 was influenced by inclusion of hemolysed specimens.
Studies
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Study Purpose
The purpose of this study was to determine the effects of including hemolyzed specimens when comparing plasma miRNA levels between CRC patients and healthy controls or CRC patients pre- and post-surgical excision. EDTA plasma was obtained from 65 CRC patients (stages I-IV) the day before surgery, from 46 CRC patients 4-6 months post-surgery and from 70 healthy blood donors. All plasma specimens were stored at -80˚C until analysis. RNA was extracted using a modified Trizol or QIazol reagent protocol which included the miRNeasy Mini Kit columns. miRNA were quantified using Taqman assays. Specimens were considered hemolyzed if the ratio of the absorbance at 414 nm and 375 nm was ≤2.
Summary of Findings:
Plasma levels of miR-21 and miR-378 were higher in CRC patients than in healthy individuals (p=0.046 and p=0.001, respectively), but when analysis was restricted to hemolysis-free plasma, only the difference in miR-378 was significant (p=0.023). Further, plasma levels of miR-378 were lower 4-6 months following CRC surgery than pre-surgical levels, regardless of whether all specimens or only hemolysis-free plasma were included (p<0.0001 and p=0.0002, respectively). miR-21 levels were not significantly affected by surgery.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform Cell count/volume Spectrophotometry RNA Real-time qRT-PCR Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Hemolysis Absent
Present
Real-time qRT-PCR Specific Targeted nucleic acid miR-21
miR-378
Biospecimen Acquisition Time of biospecimen collection 1 day before surgery
4-6 months post-surgery
Preaquisition Diagnosis/ patient condition Healthy
CRC