Author(s)

Katsushige Inada^1*, Yasushi Okoshi^1,2,3, Yukiko Cho⁴, Hitoaki Saito⁵, Tatsuo Iijima⁵, Mitsuo Hori¹, Hiroshi Kojima^2,3,4

¹Department of Hematology, Ibaraki Prefectural Central Hospital, Ibaraki, Japan.
²Ibaraki Clinical Education and Training Center, University of Tsukuba Hospital, Ibaraki, Japan.
³Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
⁴Department of Medical Oncology, Ibaraki Prefectural Central Hospital, Ibaraki, Japan.
⁵Department of Pathology, Ibaraki Prefectural Central Hospital, Ibaraki, Japan.

Background: MicroRNA (miRNA) regulates post-transcriptional gene expression through binding to complementary sites of target messenger RNA, including that from oncogenes or tumor suppressor genes. This study planned to pursue the possibility that circulating miRNA could be used for the early diagnosis of diffuse large B-cell lymphoma (DLBCL). Materials and Methods: Expression levels of miRNA obtained from serum, exosome-enriched serum, and formalin-fixed paraffin-embedded (FFPE) tissue were evaluated. Samples were collected from patients with newly diagnosed DLBCL (n = 33) or healthy volunteers (n = 22). Based on the results of previous reports, ten miRNAs were selected and expression levels were analyzed by the quantitative real-time PCR. Results: The expression levels of hsa-miR-15a-3p, hsa-miR-21-5p, hsa-miR-181a-5p, and hsa-miR-210-5p differed significantly between DLBCL patients and controls in serum and/or exosome-enriched serum, but not in FFPE tissue. In contrast, expression levels of hsa-miR-155-5p in FFPE tissue were significantly higher in DLBCL patients, as previously reported. Conclusion: We confirmed that some miRNAs were differentially expressed in serum from DLBCL patients as previously reported. Measurement of these miRNA in exosome-enriched serum did not improve the accuracy in the differential diagnosis of DLBCL. In addition, these miRNAs seem to be produced outside of lymphoma tissue.

DLBCL, miRNA, Serum, Exosome, Formalin-Fixed Paraffin-Embedded Tissue

Inada, K. , Okoshi, Y. , Cho, Y. , Saito, H. , Iijima, T. , Hori, M. and Kojima, H. (2015) Availability of Circulating MicroRNAs as a Biomarker for Early Diagnosis of Diffuse Large B-Cell Lymphoma. Open Journal of Blood Diseases, 5, 48-58. doi: 10.4236/ojbd.2015.54008.