Changes in RPS14 expression levels during lenalidomide treatment in Low- and Intermediate-1-risk myelodysplastic syndromes with chromosome 5q deletion.

Background: Haploinsufficiency of the ribosomal protein S14 RPS14 gene, located in the common deleted region of chromosome 5q, is a potential causal factor of 5q- syndrome. Lenalidomide elicits high response rates and morphological improvements in myelodysplastic syndrome (MDS) patients with chromosome 5q deletion [del(5q)].

Methods: To further evaluate the role of RPS14, its transcription was tested in bone marrow cells from 17 patients with International Prognostic Scoring System defined Low- or Intermediate-1-risk MDS with del(5q) as a single or additional cytogenetic abnormality receiving treatment with lenalidomide.

Results: After 12 wk of lenalidomide treatment, erythroid responses were observed in all cases with an increase in hemoglobin levels of 2.7 +/- 2.5 g/dL (up to a mean 11.8 +/- 1.9 g/dL; P = 0.001). Before treatment, RPS14 expression levels were under-expressed in 15 patients with respect to normal controls. After 12 wk of lenalidomide treatment, all patients had an erythroid response. There was a significant increase in median RPS14 expression from baseline 0.01 (IQR 0.05-0.31) to 12 wk 204.71-fold (2.86-446.32; P < 0.0001).

Conclusions: These observations in the patient setting support the importance of RPS14 in the pathogenesis of MDS with del(5q).