Scientific publications
Post-transcriptional modifications contribute to the upregulation of cyclin D2 in multiple myeloma
Misiewicz-Krzeminska I (1), Sarasquete ME (2), Vicente Duenas C (3), Krzeminski P (4), Wiktorska K (5), Corchete L (6), Quwaider D (7), Rojas E (1), Corral R (8), Martin AA (9), Escalante F (10), Barez A (11), Garcia JL (12), Sanchez-Garcia I (13), Garcia-Sanz R (2), San-Miguel JF (14), Gutierrez NC (15).
BACKGROUND
Dysregulation of one of the three D cyclin genes has been observed in virtually all multiple myeloma (MM) tumors. The mechanisms by which CCND2 is upregulated in a set of multiple myeloma (MM) are not completely deciphered. We investigated the role of post-transcriptional regulation through the interaction between miRNAs and their binding sites at 3'UTR in CCND2 overexpression in MM.
EXPERIMENTAL DESIGN
Eleven myeloma cell lines and 45 primary myeloma samples were included in the study. Interactions between miRNAs deregulated in MM and mRNA targets were analyzed by 3'UTR-luciferase plasmid assay. The presence of CCND2 mRNA isoforms different in length was explored using qRT-PCR, Northern blot, mRNA FISH and 3'RACE-PCR.
RESULTS
We detected the presence of short CCND2 mRNA, both in MM cell lines and primary cells. The results obtained by 3'RACE experiments revealed that changes in CCND2 3'UTR length are explained by alternative polyadenylation. The luciferase assays using plasmids harboring the truncated CCND2 mRNA strongly confirmed the loss of miRNA sites in the shorter CCND2 mRNA isoform.
Those MMs with greater abundance of the shorter 3'UTR isoform were associated with significant higher level of total CCND2 mRNA expression. Furthermore, functional analysis showed significant CCND2 mRNA shortening after CCND1 silencing and an increased relative expression of longer isoform after CCND1 and CCND3 overexpression, suggesting that cyclin D1 and D3 could regulate CCND2 levels through modifications in polyadenylation-cleavage reaction.
CONCLUSIONS
Overall, these results highlight the impact of CCND2 3'UTR shortening on miRNA-dependent regulation of CCND2 in MM.
CITATION Clin Cancer Res. 2016 Jan 1;22(1):207-17. doi: 10.1158/1078-0432.CCR-14-2796.