Low Expression of RPS14 Accompanied with p53-Independent Over-Apoptosis in Myelodysplastic Syndromes Patients with 5q- Aberration

In this study, we focused on evaluating ribosomal protein S14 (RPS14) and p53 expression and their correlation analysis with the purpose of investigating the role of RPS14-MDM2-p53 pathway in hematopoietic cell apoptosis of myelodysplatic syndrome (MDS) patients with 5q- aberration.

Real time quantitative PCR was used to detect the expression levels of RPS14, MDM2 and p53 in 18 MDS patients, among which 7 with isolated del (5q) and 11 del (5q) with other chromosomal abnormalities were included. Besides, alkaline phosphatase-anti-alkaline phosphatase (APAAP) and terminal deoxynucleotidyI transferase dUTP nick end labeling (TUNEL) techniques were carried out simultaneously for each sample to respectively examine the expression of p53 and the apoptosis level of bone marrow (BM) mononuclear cells (MNCs). 10 healthy controls were included in the study.

under-expression of RPS14 gene was seen in 15/18 patients' (83.3%), of which 6/7 were isolated 5q- and 9/11 were 5q- with other chromosomal abnormalities. RPS14 expression was negatively correlated with the proportion of 5q- clonal cell in BM while it showed a positive correlation with both of the expression of MDM2 and p53. The expression of p53 was not correlated to the high apoptosis level of BM in patients with del (5q). Furthermore, APAAP and TUNEL results demonstrated apoptotic cells in patients BM were p53-negative (see Fig 1). Conclusions: RPS14 gene was under-expressed in MDS patients with 5q- aberration, which did not result in a p53-dependent apoptosis. A p53-independent pathway may contribute to the over apoptosis of 5q- MDS patients.

Fig 1

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P53 expression and cell apoptosis were simultaneously detected on bone marrow cytospins from del(5q) patients respectively by APAAP and apoptosis. P53 positive cells (red signal indicted by black arrows in panel A and C) did not present apoptosis signal (white arrow in panel B and D), While Apoptosis cell (red arrow in panel B and D) showed p53-negeative signal (yellow arrow in panel A and C).

Fig 1

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P53 expression and cell apoptosis were simultaneously detected on bone marrow cytospins from del(5q) patients respectively by APAAP and apoptosis. P53 positive cells (red signal indicted by black arrows in panel A and C) did not present apoptosis signal (white arrow in panel B and D), While Apoptosis cell (red arrow in panel B and D) showed p53-negeative signal (yellow arrow in panel A and C).

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No relevant conflicts of interest to declare.