In sum-mary, this study confirms frequent aberrant expression of cyclin D2 and D3 in t(11;14)-negative MCLs and shows a t(11;14)-independent expression of cy-clin D1 in 25% of present cases.
Specific lentiviral shRNA-mediated knockdown of cyclin D1 in mantle cell lymphoma has minimal effects on cell survival and reveals a regulatory circuit with cyclin D2.
We analyzed 4 cases of cycD2(+) mantle cell lymphoma with a translocation involving the CCND2 locus, and its differential diagnosis from 35 mature B-cell non-Hodgkin's lymphomas based on immunohistochemistry, quantitative RT-PCR and FISH analysis.
Cyclin D2 and D3 mRNA levels were significantly higher in cyclin D1-negative mantle cell lymphoma than in conventional mantle cell lymphoma but the protein expression was not discriminative.
In mantle-cell lymphoma, the t(11;14) translocation leads to overexpression of cyclin-D1, in addition to which cyclin-D1-negative mantle-cell lymphoma that overexpress cyclin-D2 or D3 have also been described.
In this issue of Blood, Salaverria et al report that more than half of Cyclin D1- (CCND1) negative SOX11-positive mantle cell lymphoma (MCL) had CCND2 gene rearrangement predominantly with immunoglobulin (IG) light chain genes.(1)
The patient was transferred to our hospital, flow cytometry using additional markers showed that the clonal cells were CD200+(dim), CD148+(strong), and chromosome analysis revealed a complex karyotype, 47, XY, t(12;14)(p13;q32), +12, del(9p21), which indicated over-expression of CCND2, and immunostaining showed strong positivity of SOX11 further confirming the characteristics of CCND1-negtive MCL.