TP53 codon 72 polymorphism predicts chronic myeloid leukemia susceptibility and treatment outcome

Exploring the significance of MDM2 gene promoter variants in chronic myeloid leukemia

Tyrosine kinase inhibitors (TKIs) targeting BCR::ABL1 are highly successful in chronic myeloid leukemia (CML). However, extensive interpatient variability in therapeutic responses and resistance supports the need to find new prognostic biomarkers. We have previously reported that TP53 SNP215 variant affects CML risk and clinical outcome. We aimed to evaluate the role of MDM2 genetic variants in CML susceptibility and treatment response to TKIs. We genotyped five MDM2 promoter variants (del1518, SNP309, SNP285, SNP288 and SNP344) in 135 CML patients and 136 healthy individuals. Our study showed that MDM2 variants alone or in combination had no effect on CML susceptibility. The analysis of MDM2 genotypes in relation to patients' clinical parameters revealed that individuals with SNP309 G/G genotypes were at a significantly increased risk of undergoing molecular response failure (p = 0.044). Improved overall survival was also observed for non-responders with the alternative MDM2 del1518 del allele (p = 0.017) as well as for MDM2 del1518-SNP309 combinations with alternative genotypes (p = 0.014). In addition, combinatorial analysis demonstrated that alternative MDM2 SNP309 and TP53 SNP215 genotypes together are associated with faster achievement of MR2 (p = 0.029) and MMR (p = 0.042) in non-responders, suggesting a relationship with a favorable outcome. Overall, our study highlights the influence of MDM2 variants on clinical outcome, supporting that specific genotypes, alone or in combination, underlie the treatment-responsive phenotype.

From regulation to deregulation of p53 in hematologic malignancies: implications for diagnosis, prognosis and therapy

The p53 protein, encoded by the TP53 gene, serves as a critical tumor suppressor, playing a vital role in maintaining genomic stability and regulating cellular responses to stress. Dysregulation of p53 is frequently observed in hematological malignancies, significantly impacting disease progression and patient outcomes. This review aims to examine the regulatory mechanisms of p53, the implications of TP53 mutations in various hematological cancers, and emerging therapeutic strategies targeting p53. We conducted a comprehensive literature review to synthesize recent findings related to p53's multifaceted role in hematologic cancers, focusing on its regulatory pathways and therapeutic potential. TP53 mutations in hematological malignancies often lead to treatment resistance and poor prognosis. Current therapeutic strategies, including p53 reactivation and gene therapy, show promise in improving treatment outcomes. Understanding the intricacies of p53 regulation and the consequences of its mutations is essential for developing effective diagnostic and therapeutic strategies in hematological malignancies, ultimately enhancing patient care and survival.

Clinical pharmacokinetics and drug-drug interactions of tyrosine-kinase inhibitors in chronic myeloid leukemia: A clinical perspective

In the past decade, numerous tyrosine kinase inhibitors (TKIs) have been introduced in the treatment of chronic myeloid leukemia. Given the significant interpatient variability in TKIs pharmacokinetics, potential drug-drug interactions (DDIs) can greatly impact patient therapy. This review aims to discuss the pharmacokinetic characteristics of TKIs, specifically focusing on their absorption, distribution, metabolism, and excretion profiles. Additionally, it provides a comprehensive overview of the utilization of TKIs in special populations such as the elderly, children, and patients with liver or kidney dysfunction. We also highlight known or suspected DDIs between TKIs and other drugs, highlighting various clinically relevant interactions. Moreover, specific recommendations are provided to guide haemato-oncologists, oncologists, and clinical pharmacists in managing DDIs during TKI treatment in daily clinical practice.

Association of TP53 gene polymorphisms with the risk of acute lymphoblastic leukemia in Moroccan children

BACKGROUND

TP53 gene plays a pivotal role in maintaining genetic stability and prevention of malignancies. Alterations of this gene are implicated in more than half of human cancers. To the best of our knowledge, this study is the first to explore TP53 polymorphisms in Moroccan childhood acute lymphoblastic leukemia (ALL).

METHODS AND RESULTS

DNA samples of 45 ALL children were obtained from peripheral blood. A total of 333 healthy Moroccans were used as controls. Polymerase chain reaction and Sanger sequencing were performed to analyze TP53 hotspot exons in cases. We identified a significant protective effect of the TP53-Arg variant at rs1042522 [OR 0.4593 (0.249-0.8472), p = 0.0127] and the Pro/Arg genotype [OR 0.0350 (0.0047-0.2583), p = 0.0010]. Additionally, we found a novel association between the C-allele of Arg213Arg 1800372 [OR 2.7736 (1.3821-5.5664), p = 0.0041] and the risk of childhood ALL. Importantly, TC/CC genotypes of this polymorphism were revealed to enhance the risk of ALL among females [OR 9.0 (3.1555-25.6693), p < 0.0001]. Arg213Arg was also noticed to be associated with the hemoglobin count of patients at diagnosis by linear regression (p = 0.0318). The analysis of penetrance showed a significant association of the CG/GG genotypes at rs1042522 and TC/CC genotypes at rs1800372 to childhood ALL via dominant model [OR 0.2090 (0.09074-0.4814), p = 0.0002 and OR 3.4205 (1.6084-7.2742), p = 0.0014 for rs1042522 and rs1800372 respectively]. No association was found between TP53 polymorphisms and patients survival.

CONCLUSION

Altogether, our findings indicated that TP53 polymorphisms are significantly involved in the genetic susceptibility to childhood ALL in Morocco.

Importance of p53 gene polymorphisms in myelodysplastic syndrome disease

Aim: Myelodysplastic syndrome (MDS) is a clonal disease with a high risk of conversion to acute myeloid leukemia, characterized by increased apoptosis and decreased hematopoiesis. The pathogenesis of MDS has not been fully explained. ~50% of cases have abnormal karyotype and this rate is around 80% in secondary MDS. The p53 protein is an important regulator of stem cell homeostasis and is involved in a range of cellular events such as cell cycle regulation, apoptotic and inflammatory response. The TP53 gene, which has important roles in maintaining genomic integrity, is frequently mutated in cancers; however, some gene polymorphisms are known to be associated with cancer, as well as mutations. Our aim in the study is to determine the prevalence of four common p53 single nucleotide polymorphisms in MDS and their effects on disease development. For this reason, 100 cases followed up with the diagnosis of MDS or newly diagnosed in Ege University Faculty of Medicine, Department of Internal Medicine, Department of Hematology were included in the study. Materials and Methods: DNAs isolated from peripheral blood leukocytes of MDS cases were studied by real-time PCR method, p53 polymorphisms (rs35163653, rs35993958, rs1800371, rs1042522) were determined by using appropriate probes and melting curve analysis. Results: Among the four common p53 polymorphisms examined, especially the non-ancestral G allele in the rs1042522 polymorphism was observed to be increased in MDS cases (C: 30.3%; G: 69.7%). In this polymorphism, which is known to be functional, that is, affecting the function of the synthesized protein, the transition of the C nucleotide at position 417 to G (C>G) causes the coding of the amino acid proline at position 72 of the protein to arginine (P72R). Conclusion: Our study is the first to investigate the p53 polymorphisms of rs35163653, rs35993958, rs1800371 and rs1042522 in the MDS disease group. Of these, rs1042522 polymorphism has been shown to be associated with cancer susceptibility and susceptibility, and it is thought that it may pose a high risk for MDS disease as well. In conclusion, rs1042522 polymorphism may be used as a marker in the diagnosis of MDS in the future by repeating this study for MDS disease with a larger case group.

Genetic Biomarkers in Chronic Myeloid Leukemia: What Have We Learned So Far?

Chronic Myeloid Leukemia (CML) is a rare malignant proliferative disease of the hematopoietic system, whose molecular hallmark is the Philadelphia chromosome (Ph). The Ph chromosome originates an aberrant fusion gene with abnormal kinase activity, leading to the buildup of reactive oxygen species and genetic instability of relevance in disease progression. Several genetic abnormalities have been correlated with CML in the blast phase, including chromosomal aberrations and common altered genes. Some of these genes are involved in the regulation of cell apoptosis and proliferation, such as the epidermal growth factor receptor (EGFR), tumor protein p53 (TP53), or Schmidt-Ruppin A-2 proto-oncogene (SRC); cell adhesion, e.g., catenin beta 1 (CTNNB1); or genes associated to TGF-β, such as SKI like proto-oncogene (SKIL), transforming growth factor beta 1 (TGFB1) or transforming growth factor beta 2 (TGFB2); and TNF-α pathways, such as Tumor necrosis factor (TNFA) or Nuclear factor kappa B subunit 1 (NFKB1). The involvement of miRNAs in CML is also gaining momentum, where dysregulation of some critical miRNAs, such as miRNA-451 and miRNA-21, which have been associated to the molecular modulation of pathogenesis, progression of disease states, and response to therapeutics. In this review, the most relevant genomic alterations found in CML will be addressed.

Polymorphisms in the CYP2A6 and ABCC4 genes are associated with a protective effect on chronic myeloid leukemia in the Brazilian Amazon population

BACKGROUND

Susceptibility to Chronic Myeloid Leukemia (CML) may be modulated by genetic variables. However, the majority of previous investigations have focused on genetically homogeneous populations, resulting in a lack of evidence on how genetic factors may influence the development of CML in miscegenated populations. We analyzed 30 polymorphisms in genes related to DNA repair, folate metabolism, transmembrane transport, xenobiotic metabolism, and pyrimidine synthesis in relation to their potential role in the susceptibility of the individual to CML.

METHODS

This case-control study included 126 healthy individuals and 143 patients diagnosed with CML from the admixed population of the Brazilian Amazon. The samples were genotyped by real-time PCR and the genetic ancestry analysis was based on a panel of 61 ancestry informative markers.

RESULTS

The results indicated a protective effect against the development of CML in carriers of the C allele of the rs28399433 (CYP2A6) gene and the CC genotype of the rs3742106 (ABCC4) gene.

CONCLUSION

Our findings suggest that the rs3742106 (ABCC4) and rs28399433 (CYP2A6) polymorphisms may modulate susceptibility to CML in a population of the Brazilian Amazon region.

Super-Enhancer-Associated Hub Genes In Chronic Myeloid Leukemia Identified Using Weighted Gene Co-Expression Network Analysis

Purpose

Super-enhancer (SE)-associated oncogenes extensively potentiate the uncontrolled proliferation capacity of cancer cells. In this study, we aimed to identify the SE-associated hub genes associated with the clinical characteristics of chronic myeloid leukemia (CML).

Methods

Eigengenes from CML clinical modules were determined using weighted gene co-expression network analysis (WGCNA). Overlapping genes between eigengenes and SE-associated genes were used to construct protein–protein interaction (PPI) networks and annotate for pathway enrichment analysis. Expression patterns of the top-ranked SE-associated hub genes were further determined in CML patients and healthy controls via real-time PCR. After treatment of K562 cells with the BRD4 inhibitor, JQ1, for 24 hrs, mRNA and protein levels of SE-associated hub genes were evaluated using real-time PCR and Western blotting, respectively. H3K27ac, H3K4me1 and BRD4 ChIP-seq signal peaks were used to predict and identify SEs visualized by the Integrative Genomics Viewer.

Results

The yellow module was significantly related to the status and pathological phase of CML. SE-associated hub candidate genes were mainly enriched in the cell cycle pathway. Based on the PPI networks of hub genes and the top rank of degree, five SE-associated genes were identified: specifically, BUB1, CENPO, KIF2C, ORC1, and RRM2. Elevated expression of these five genes was not only related to CML status and phase but also positively regulated by SE and suppressed by the BRD4 inhibitor, JQ1, in K562 cells. Strong signal peaks of H3K27ac, H3K4me1 and BRD4 ChIP-seq of the five genes were additionally observed close to the predicted SE regions.

Conclusion

This is the first study to characterize SE-associated genes linked to clinical characteristics of CML via weighted gene co-expression network analysis. Our results support a novel mechanism involving aberrant expression of hub SE-associated genes in CML patients and K562 cells, and these genes will be potential new therapeutic targets for human leukemia.

TP53 Arg72 as a favorable prognostic factor for Chinese diffuse large B-cell lymphoma patients treated with CHOP

Background

TP53 Arg72Pro (SNP rs1042522) is associated with risk of non-Hodgkin lymphoma (NHL). Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of NHL. However, the relationship between this SNP and prognosis of DLBCL in Asians is unknown.

Methods

Genotyping of TP53 Arg72Pro was done in 425 Chinese DLBCL patients. Two hundred and eighty-nine patients were treated with R-CHOP, and 136 patients received CHOP or CHOP-like as frontline regimen. Three hundred and ninety-six patients were assessable for the efficacy.

Results

Patients with Arg/Arg and Arg/Pro at codon 72 of TP53 had a higher complete response rate (61% vs. 44%, P = 0.007) than those with Pro/Pro. In the subgroup treated with CHOP or CHOP-like therapy, patients with Arg/Arg and Arg/Pro showed a higher 5-year overall survival (OS) rate than those with Pro/Pro (68.8% vs. 23.2%, P = 0.001). Multivariate Cox regression analysis revealed TP53 Arg72 as a favorable prognostic factor in this group. However, the combination of rituximab with CHOP significantly increased the 5-year OS rate of patients with Pro/Pro to 63%.

Conclusion

This study revealed TP53 Arg72 as a favorable prognostic factor for Chinese DLBCL patients treated with CHOP or CHOP-like as frontline therapy.