Contributions
Abstract: PB1912
Type: Publication Only
Background
Aims
The objective of this work was to explore the origin of RPS14 low expression in non-5q- MDS patients and its link with 5q- pathology. In order to do this, we analysed potential mutations in RPS14 gene. We also studied expression changes in other key genes involved in the development of the 5q- disease, including the tumour suppressor gene SPARC and the putative tumour suppressor gene CSNK1A1, contained in the commonly deleted region. Moreover, other 32 genes related with MDS disorders were evaluated in relation with RPS14 levels. Finally, in order to establish if this group of patients could be beneficed by lenalidomide therapy, p21 expression levels were also analysed.
Methods
DNA and RNA were extracted from the bone marrow of 89 non-5q- MDS patients. Ten controls and nine 5q- MDS patients were used as negative and positive controls, respectively. RPS14, SPARC, CSNK1A1 and p21 mRNA levels were analysed by real time PCR using Taqman probes in a 7500 RT PCR System. β-glucuronidase gene was used as endogenous reference to normalize data. Samples were classified by RPS14 expression levels and differences in SPARC, CSNK1A1 and p21 expression mean values between the two groups were analysed using the Mann-Whitney U test. RPS14 and 32 genes related with MDS were analysed using Ion Proton sequencing.
Results
Non-5q- patients expressing low levels of RPS14 presented higher survival probability in the IPSS lower risk group. This data, in addition with a tendency for increased p21 expression, suggests that this group could be beneficed by lenalidomide therapy. Nevertheless, we did not observe a significant decrease in SPARC and CSNK1A1 expression in patients with low levels of RPS14, discarding alterations in the adjacent genes commonly deleted in 5q- MDS patients. In addition, the majority of patients analysed did not present any mutation in RPS14 gene. Only two MDS patients showed mutations upstream, downstream or within intronic regions of the gene. Then, the origin of RPS14 decreased expression seems not to be related with genomic alterations in 5q region. On the other hand, mutations in FLT3, U2AF1, DNM3A and CBL were frequently observed in this group of patients.
Conclusion
Although the important role of RPS14 in MDS pathology has been recently demonstrated, the origin of RPS14 downregulation in about 50% non-5q- patients remains unknown. Our results suggest that the origin of RPS14 decreased expression is not related with genomic alterations in 5q region. Further studies are necessaries in order to establish a link with 5q- pathology and demonstrate the potential use of lenalidomide in this group of patients.
Session topic: 9. Myelodysplastic syndromes - Biology
Keyword(s): Quantitative RT-PCR, P21, MDS, Chromosomal abnormality
Abstract: PB1912
Type: Publication Only
Background
Aims
The objective of this work was to explore the origin of RPS14 low expression in non-5q- MDS patients and its link with 5q- pathology. In order to do this, we analysed potential mutations in RPS14 gene. We also studied expression changes in other key genes involved in the development of the 5q- disease, including the tumour suppressor gene SPARC and the putative tumour suppressor gene CSNK1A1, contained in the commonly deleted region. Moreover, other 32 genes related with MDS disorders were evaluated in relation with RPS14 levels. Finally, in order to establish if this group of patients could be beneficed by lenalidomide therapy, p21 expression levels were also analysed.
Methods
DNA and RNA were extracted from the bone marrow of 89 non-5q- MDS patients. Ten controls and nine 5q- MDS patients were used as negative and positive controls, respectively. RPS14, SPARC, CSNK1A1 and p21 mRNA levels were analysed by real time PCR using Taqman probes in a 7500 RT PCR System. β-glucuronidase gene was used as endogenous reference to normalize data. Samples were classified by RPS14 expression levels and differences in SPARC, CSNK1A1 and p21 expression mean values between the two groups were analysed using the Mann-Whitney U test. RPS14 and 32 genes related with MDS were analysed using Ion Proton sequencing.
Results
Non-5q- patients expressing low levels of RPS14 presented higher survival probability in the IPSS lower risk group. This data, in addition with a tendency for increased p21 expression, suggests that this group could be beneficed by lenalidomide therapy. Nevertheless, we did not observe a significant decrease in SPARC and CSNK1A1 expression in patients with low levels of RPS14, discarding alterations in the adjacent genes commonly deleted in 5q- MDS patients. In addition, the majority of patients analysed did not present any mutation in RPS14 gene. Only two MDS patients showed mutations upstream, downstream or within intronic regions of the gene. Then, the origin of RPS14 decreased expression seems not to be related with genomic alterations in 5q region. On the other hand, mutations in FLT3, U2AF1, DNM3A and CBL were frequently observed in this group of patients.
Conclusion
Although the important role of RPS14 in MDS pathology has been recently demonstrated, the origin of RPS14 downregulation in about 50% non-5q- patients remains unknown. Our results suggest that the origin of RPS14 decreased expression is not related with genomic alterations in 5q region. Further studies are necessaries in order to establish a link with 5q- pathology and demonstrate the potential use of lenalidomide in this group of patients.
Session topic: 9. Myelodysplastic syndromes - Biology
Keyword(s): Quantitative RT-PCR, P21, MDS, Chromosomal abnormality