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CLL cells affect osteoblastogenesis/osteoclastogenesis
ly significant reduction was also observed in cathepsin K transcript levels when the culture condition included CLL- cm but was devoid of RANKL (Figure 4E).
Osteoclasts derived in the presence of MCSF+RANKL and CLL-conditioned media show higher bone resorption activity
We then observed that only large, fully differentiated and multinucleated osteoclasts, derived after
MCSF+RANKL stimulation, show significant bone resorption activity and larger erosion areas were detected when CLL-cm was concomitantly added in these cultures (Figure 5A-C). Small tri-nucleated cells, generated with MCSF+CLL-cm only, although TRAP+, produced very small detectable erosion pits (Figure 5B). Similar results were obtained when an increased number of RANKL+ CLL cells (from 1x106 to 2x106/well) were added with MCSF, instead of the conditioned medium, attempting to
Figure 1. The addition of CLL conditioned media, CLL sera or CLL cells to osteo-induced bone marrow stromal cells impairs their differentiation. The addition of CLL conditioned medium (cm), CLL sera (sr) or CLL cells, in contact (co) or in transwell (tw), to cultures of bone marrow stromal cells (BMSC), induced to differentiate in standard osteogenic medium, inhibited their complete differentiation to osteoblasts. RUNX2 and osteocalcin transcript levels were significantly decreased. In con- trast, DKK-1 and osteopontin mRNA levels were increased when CLL-cm, CLL-sr or CLL cells were added to the cultures, as compared with levels when control BMSC were cultured with osteogenic medium only. Given the extremely high average and corresponding standard deviation values of DKK-1 mRNA levels, statistical sig- nificance was not achieved for CLL-cm and CLL-sr treatment. The mRNA expression of the same genes of interest was also evaluated in co-cultures of B cells purified from normal controls (B ctrl). n: number of cases examined for each experimental condition.
haematologica | 2021; 106(10)
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