Sex difference in myelodysplastic syndrome survival and balance in randomized clinical trials

Cytogenetic features in primary myelodysplastic syndrome Egyptian patients

Karyotype is the most important diagnostic and prognostic parameter in myelodysplastic syndromes (MDS) and is abnormal in approximately 50% of patients. We emphasized the importance of chromosomal analysis and reported the most frequent cytogenetic abnormalities in 50 MDS (29 males (58%) and 21 females (42%), median age: 57.5 years) Egyptian patients using conventional banding analysis (CBA). Karyotype description was conducted according to the International System for Human Cytogenetic Nomenclature (ISCN, 2013). Patients were diagnosed based on complete history, bone marrow (BM) aspirate, peripheral blood (PBL) examination, and Iron stain. MDS with multilineage dysplasia (MDS-MLD) was the most frequently encountered subtype; 19/50 (38%) followed by MDS with single lineage dysplasia (MDS-SLD); 11/50 (22%). 27/50 patients (54%) showed a normal karyotype while 23 patients (46%) showed clonal nonrandom chromosomal abnormalities. Most patients with MDS with excess blasts-II (MDS-EB-II) showed abnormal karyotype (3/4; 75%) followed by MDS-EB-I (3/5, 60%) and MDS-MLD (10/19, 53%). Among 50 primary MDS patients; 14/50 (28%) had a single chromosomal abnormality, 3/50 (6%) had double chromosomal abnormality, and 6/50 (12%) had complex karyotype. Male sex was more frequently associated with higher IPSS prognostic risk categories than female gender. The most common single chromosomal abnormalities were −5/del5q; 7/50 (14%) patients followed by −7; 4/50 (8%) patients. +8, del20q and delY were each detected in 1/50 patient (2%). Abnormalities of chromosome 5 (−5/del5q) as a single chromosomal abnormality was the most frequent chromosomal abnormality among Egyptian primary MDS patients followed by complex karyotype. Cytogenetic characteristics of MDS Egyptian patients were similar to North African and European patients. Karyotype offers useful information in establishing accurate diagnosis and male gender is an important predisposing factor that can predict worse prognosis in MDS patients.

SLC7A5 act as a potential leukemic transformation target gene in myelodysplastic syndrome

Objective

Myelodysplastic syndromes (MDS) are a heterogenous group of clonal hematopoietic stem cell disorders characterized by increased risk of leukemic transformation. This study identifies microRNAs(miRNA) and miRNA targets that might represent leukemic transformation markers for MDS.

Methods

Based on our previously established nested case-control study cohort of MDS patients, we chose paired patients to undergo Angilent 8 × 15K human miRNA microarrays. Target prediction analysis was administrated using targetscan 5.1 software. We further investigated the function of target gene in MDS cell line using siRNA method, including cell proliferation, cell apoptosis, cell cycle and electron microscope.

Results

Finally we screened a subset of 7 miRNAs to be significantly differentially expressed between the case (at the end of follow up with leukemic transformation) and control group (at the end of follow up without leukemic transformation). Target prediction analysis revealed SLC7A5 was the common target gene of these 7 miRNAs. Further study on the function of SLC7A5 gene in SKM-1 cell line showed that downregulation of SLC7A5 inhibited SKM-1 cells proliferation, increased apoptosis and caused cell cycle arrest in the G0/G1 stage.

Conclusion

Our data indicate that SLC7A5 gene may act as a potential leukemic transformation target gene in MDS.

In patients with myelodysplastic syndromes with del(5q), factors other than age and sex contribute to the prognostic advantage, which diminishes over time

This study aimed to determine the extent to which the prognostic advantage of myelodysplastic syndromes (MDS) with del(5q) is due to the more favourable age and sex distribution of patients in that group when compared to other MDS subtypes. A total of 1912 MDS patients from the Duesseldorf registry with less than 5% blasts in the bone marrow were evaluable and had complete covariates. As endpoints, overall survival and progression to acute myeloid leukaemia (AML) were considered. Cox models were computed for both outcomes. A multivariate Cox model for survival confirmed higher age and male sex as risk factors. In addition, we found a survival advantage of 9·1 years for MDS del(5q) patients compared to refractory cytopenia with unilineage dysplasia, while the survival advantage of MDS del(5q) over refractory cytopenia with multilineage dysplasia was 18·6 years. Considering progression to AML, we did not find any significant differences between the World Health Organization classification subtypes. Our analyses show that the higher survival probabilities of MDS del(5q) patients are not only due to age and sex, although higher age and male sex were also important risk factors. Interestingly, it seems that the survival advantage of MDS del(5q) decreases over time.