Page 68 - GTM-3-2

Global Translational Medicine Genes and blood cells in Ph-negative MPNs

The insertion or deletion of guanosine at 675 bp 2. Methods
upstream of the transcription start site results in the
presence of a 4G/5G gene polymorphism in the promoter 2.1. Subject data and control sample
of the PAI-1 gene. This polymorphism is characterized This study examined the blood samples from 56 patients
by three distinct genotypes: 4G/4G, 4G/5G, and 5G/5G, (34 women and 22 men) diagnosed with ET (n = 22), PV
which regulate the expression level of PAI-1. The plasma (n = 19), and the pre-fibrotic phase of PMF (n = 15) before
PAI-1 level is the highest in genotype 4G/4G, followed by the initiation of treatment. The age of patients ranged
genotype 4G/5G, and is the lowest in genotype 5G/5G. It from 19 to 82 years (median: 53 years). The examinations
has been suggested that the 4G/5G gene polymorphism were conducted at the Laboratory of Molecular Genetics,
and the level of PAI-1 protein are closely related to arterial Institute of Blood Pathology and Transfusion Medicine,
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and venous thrombosis. The data presented by Zhang National Academy of Medical Sciences (NAMS) of
20
et al. indicate that the incidence of thrombotic events in Ukraine, during 2021 – 2022. The diagnosis of Ph-negative
patients with ET is significantly higher in those with the MPNs was established on the basis of a comprehensive
4G/4G polymorphism of the PAI-1 gene than in those evaluation of clinical, hematological, and molecular genetic
with the 4G/5G or 5G/5G genotypes. Furthermore, the examinations. The 2016 World Health Organization
4G/4G polymorphism of the PAI-1 gene and infection are criteria were used for diagnosis, incorporating the
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independent risk factors for thrombotic events in patients detection of JAK2V617F and CALR mutations, including
with Ph-negative MPNs. Finally, the data demonstrate that the two most frequent CALR mutations, a 52 base pair
the PAI-1 4G/4G polymorphism and infection in ET and (bp) deletion and a 5 bp insertion. At the time of diagnosis,
PV patients with the JAK2V617F mutation are high-risk deep vein thrombosis in the lower leg or thigh was present
factors for thrombotic events. In patients with ET and PV in three (5.4%) patients with Ph-negative MPNs, among
with prothrombotic coagulation disorders, the level of whom one had PMF and two had ET.
PAI-1 is significantly increased. 21
As the control group, we used data from a population
Therefore, elucidating the role of PAI-1 and its sample in the database of the Medis Laboratory and
gene polymorphism, as well as JAK2 mutations in the Diagnostic Center, Lviv, Ukraine, in 2020, comprising
pathogenesis of Ph-negative MPNs, can be of great CBC of 475 individuals (245 women and 230 men).
theoretical and practical importance.
2.2. Presence of the JAK2V617F mutation
This study aimed to evaluate various parameters of
complete blood count (CBC), including several integral DNA isolated from patients’ blood cells was used for
cell indices (ICIs), the −675 4G/5G polymorphism of the detecting the JAK2V617F mutation. Venous blood
PAI-1 gene, and the presence of the JAK2V617F mutation. sampling was carried out using vacuum tubes with
Furthermore, the study sought to identify potential K2 EDTA with a capacity of 3 mL. DNA isolation was
associations among these parameters in patients newly carried out with Chelex 100 Resin (Bio-Rad, USA). The
diagnosed with Ph-negative MPNs, while considering the obtained DNA was frozen in a freezer at −20°C for long-
involvement of the uPA/uPAR system in the pathogenesis term storage. Detection of the JAK2V617F mutation was
(Table 1). conducted using the real-time polymerase chain reaction

Table 1. The impact of PAI-1 overexpression caused by excessive PLT production/activation on the pathogenesis of Ph-negative
MPNs

Factors contributing to PAI-1 Consequent pathogenesis
overexpression Blood ECM Cells
(i) Increased PLT count Increased formation of (i) Increased formation of the PAI-1–uPA Increased formation of the
(ii) Activated PLT the PAI-1–tPA complex complex inhibits Pg activation, thereby PAI-1–uPA–uPAR (Ly6/uPAR
(iii) The presence of PAI-1 4G/5G inhibits Pg activation, reducing the conversion of Pg to Pm, family members) complex
polymorphism thereby reducing the ultimately heightening the risk of alters the activation of signaling
conversion of Pg to Pm and myelofibrosis pathways and transcriptional
ultimately heightening the (ii) Increased formation of the PAI-1–uPA regulation, heightening the
risk of thrombosis complex inhibits MMP activation, ultimately risk of angiogenesis and tumor
heightening the risk of myelofibrosis progression
Abbreviations: ECM: Extracellular matrix; Ly6: Lymphocyte antigen 6; MMP: Matrix metalloproteases; MNP: Myeloproliferative neoplasm; PAI-1:
Plasminogen activator inhibitor 1; Pg: Plasminogen; PLT: Platelet; Pm: Plasmin; tPA: Tissue plasminogen activator; uPA: Urokinase-type plasminogen
activator; uPAR: Urokinase-type plasminogen activator receptor.

Volume 3 Issue 2 (2024) 4 doi: 10.36922/gtm.2559