Therapeutic delivery of siRNA with polymeric carriers to down-regulate STAT5A expression in high-risk B-cell acute lymphoblastic leukemia (B-ALL)

Overexpression and persistent activation of STAT5 play an important role in the development and progression of acute lymphoblastic leukemia (ALL), the most common pediatric cancer. Small interfering RNA (siRNA)-mediated downregulation of STAT5 represents a promising therapeutic approach for ALL to overcome the limitations of current treatment modalities such as high relapse rates and poor prognosis. However, to effectively transport siRNA molecules to target cells, development of potent carriers is of utmost importance to surpass hurdles of delivery. In this study, we investigated the use of lipopolymers as non-viral delivery systems derived from low molecular weight polyethylenimines (PEI) substituted with lauric acid (Lau), linoleic acid (LA) and stearic acid (StA) to deliver siRNA molecules to ALL cell lines and primary samples. Among the lipid-substituted polymers explored, Lau- and LA-substituted PEI displayed excellent siRNA delivery to SUP-B15 and RS4;11 cells. STAT5A gene expression was downregulated (36–92%) in SUP-B15 and (32%) in RS4;11 cells using the polymeric delivery systems, which consequently reduced cell growth and inhibited the formation of colonies in ALL cells. With regard to ALL primary cells, siRNA-mediated STAT5A gene silencing was observed in four of eight patient cells using our leading polymeric delivery system, 1.2PEI-Lau8, accompanied by the significant reduction in colony formation in three of eight patients. In both BCR-ABL positive and negative groups, three of five patients demonstrated marked cell growth inhibition in both MTT and trypan blue exclusion assays using 1.2PEI-Lau8/siRNA complexes in comparison with their control siRNA groups. Three patient samples did not show any positive results with our delivery systems. Differential therapeutic responses to siRNA therapy observed in different patients could result from variable genetic profiles and patient-to-patient variability in delivery. This study supports the potential of siRNA therapy and the designed lipopolymers as a delivery system in ALL therapy.

Bovine STAT5A gene polymorphism and its influence on growth traits in Podolica breed

Signal transducers and activators of transcription (STAT) are latent cytoplasmic transcription factors that mediate the actions of a variety of peptide hormones and cytokines within target cells. STAT5A is the main mediator of growth hormone action on target genes and plays a key role as intracellular mediator of prolactin signalling. In this study, the T→C nucleotide polymorphism at position 12 743 in exon 16 of the bovine STAT5A gene was investigated with polymerase chain reaction-restriction fragment length polymorphism in a sample of Podolica young bulls. The Podolica breed derives from Bos primigenius podolicus (forebears of the modern Bos taurus), it has been present in Italy for a very long time and represents yet another example of successful biological adaptation to a hostile environment. The aims of this study were to estimate the allele and genotype frequencies in Podolica breed and to investigate a possible relationship between this polymorphism and some growth performance traits. The observed frequencies of C and T alleles were 0.344 and 0.656, respectively. The TT genotype was the most frequent in the studied population followed by TC and CC ones. Moreover, the animals carrying TT genotypes seem to show an initial faster growth, which determined higher bodyweight at 90 and 270 days of age; conversely, CC individuals exhibit a faster growth in the post-weaning period achieving the higher bodyweight at 450 days of age.

Jersey İneklerinde STAT5A Geninin Süt Verimi ve Bileşenleri Üzerine Etkisinin Araştırılması

In this study, the effect of STAT5A gene was investigated on milk yield and components (fat, protein) in Jersey cows. Because, this gene is a member of the signal transducers and activators of transcription the factor (STAT) family and thought to be the impact on milk yield and components. As a material in the research, 100 Jersey cows raised in Samsun Karakoy State Farm were used. Milk samples were collected 12 times with one month intervals after calving, and these samples were performed by ultrasonic milk analyzer for milk fat and protein content. In addition, test day milk yield (TDMY) of each cow were also recorded in the control days. C/G polymorphism with PCR-RFLP method result in DNA isolation from blood samples taken from cows was determined at 8.exon at position 12195. Genotype distribution was detected as 69% CC, 28% CG and 3% GG. Allele frequencies were found as 0.83 for the C allele and 0.17 for G allele. As a result of the polymorphism identified in STAT5A gene, statistically no difference were detected among genotypes for TDMY, 305 day milk yield (305 DMY), milk fat and protein rates and milk fat and protein yield. As a result, no significant differences were found between the milk yield and compositions association with STAT5A

Expression pattern of STAT5A gene during early bovine embryogenesis

SummaryGrowth hormone (GH) plays an important role in early embryo development. It has been shown to activate multiple pathways, the most comprehensively studied being the STAT/JAK (Signal transducers and activators of transcription/Janus kinase) pathway. The objective of the present study was to investigate STAT5A gene expression during early bovine embryogenesis. Real-time polymerase chain reaction (RT-PCR) was used to measure the abundance of STAT5A transcripts. The mRNA was present at all stages of preimplantation bovine embryos investigated. The most abundant STAT5A expression occurred at the 2-cell stage. Expression was markedly reduced between the 4-cell and 8-cell stages, coinciding with the known time of embryo genome activation and loss of maternal mRNAs. This finding suggests that the embryonic STAT5A gene is primarily activated by maternal gene products.