(Asklepios Campus Hamburg of the Semmelweis University in Budapest, Hungary)
Association studies have linked alterations of blood-derived microRNAs (miRNAs) with
colorectal cancer (CRC). Here, we performed a microarray-based comparison of the profiles
of 2549 miRNAs in 80 blood samples from healthy donors and patients with colorectal
adenomas, colorectal diverticulitis and CRC at different stages. Confirmation by quantitative
real-time PCR (RT-PCR) was complemented by validation of identified molecules in another
36 blood samples. No variations in miRNA levels were observed in samples from patients
with colorectal adenomas and diverticulitis or from healthy donors. However, there
were 179 CRC-associated miRNAs of differential abundance compared to healthy controls.
Only three - miR-1225-5p, miR-1207-5p and miR-4459 - exhibited increased levels at
all CRC stages. Most deregulated miRNAs (128/179, 71%) specifically predicted metastatic
CRC. Pathway analysis found several cancer-related pathways to which the miRNAs contribute
in various ways. In conclusion, miRNA levels in blood vary throughout CRC progression
and affect cellular functions relevant to haematogenous CRC progression and dissemination.
The identified biomarker and therapeutic candidates require further confirmation of
their clinical relevance.
