STMN1 is highly expressed and contributes to clonogenicity in acute promyelocytic leukemia cells.

Stathmin 1 (STMN1) is a microtubule-destabilizing protein highly expressed in hematological malignancies and involved in proliferation and differentiation. Although a previous study found that the PML-RARα fusion protein, which contributes to the pathophysiology of acute promyelocytic leukemia (APL), positively regulates STMN1 at the transcription and protein activity levels, little is known about the role of STMN1 in APL. In this study, we aimed to investigate the STMN1 expression levels and their associations with laboratory, clinical, and genomic data in APL patients. We also assessed the dynamics of STMN1 expression during myeloid cell differentiation and cell cycle progression, and the cellular effects of STMN1 silencing and pharmacological effects of microtubule-stabilizing drugs on APL cells. We found that STMN1 transcripts were significantly increased in samples from APL patients compared with those of healthy donors (all p < 0.05). However, this had no effect on clinical outcomes. STMN1 expression was associated with proliferation- and metabolism-related gene signatures in APL. Our data confirmed that STMN1 was highly expressed in early hematopoietic progenitors and reduced during cell differentiation, including the ATRA-induced granulocytic differentiation model. STMN1 phosphorylation was predominant in a pool of mitosis-enriched APL cells. In NB4 and NB4-R2 cells, STMN1 knockdown decreased autonomous cell growth (all p < 0.05) but did not impact ATRA-induced apoptosis and differentiation. Finally, treatment with paclitaxel (as a single agent or combined with ATRA) induced microtubule stabilization, resulting in mitotic catastrophe with repercussions for cell viability, even in ATRA-resistant APL cells. This study provides new insights into the STMN1 functions and microtubule dynamics in APL.

Detection of Human Papillomavirus DNA in Paired Peripheral Blood and Cervix Samples in Patients with Cervical Lesions and Healthy Individuals.

This study evaluated the presence of Human Papillomavirus (HPV) DNA in the cervix and peripheral blood of women with cervical intraepithelial neoplasia (CIN I, II, and III) and healthy individuals. Overall, 139 paired peripheral blood and cervix samples of healthy women and women with CIN I, II, and III (n = 68) were tested for HPV DNA by using standard procedures. Polymerase chain reaction (PCR) sequencing determined HPV types. Quantification of HPV16 E6 and E2 genes was performed to determine viral load and physical state. HPV DNA was detected in the cervix (21.1% in healthy individuals; 48.8-55.5% in CIN patients), blood (46.4% in healthy individuals; 44.1-77.7% in CIN patients) and paired peripheral blood and cervix samples (24% in healthy individuals; 32.5-44.4% in CIN patients). The most frequent types found in the cervix were HPV16, 18, 31, 33, 58, and 70, while HPV16, 18, 33, 58, and 66 were the most frequent types found in the blood. HPV DNA in the cervix was associated with previous sexually transmitted infections (STIs) (p = 0.023; OR: 2.978; CI:1.34-7.821), HPV DNA in the blood (p = 0.000; OR: 8.283; CI:3.700-18.540), and cervical lesions (CIN I/II or III) (p = 0.007). Binomial logistic regression showed that HPV DNA in the blood (p = 0.000; OR: 9.324; CI:3.612-24.072) and cervical lesions (p = 0.011; OR: 3.622; CI:1.338-9.806) were associated with HPV DNA in the cervix. However, we did not find an association between HPV DNA in the blood and cervical lesions (p = 0.385). Our results showed that only HPV DNA found in the cervix was associated with cervical lesions.

Effect of hydroxyurea therapy on intravascular hemolysis and endothelial dysfunction markers in sickle cell anemia patients.

Intravascular hemolysis (IH) contributes to the development of endothelial dysfunction (ED) in sickle cell anemia (SCA), and the effects of hydroxyurea (HU, the only approved drug that decreases the frequency and severity of vaso-oclussive crises) on IH and ED in SCA remain unclear. We evaluated and compared the markers of IH among steady-state adult Brazilians with SCA and HbAA individuals. Overall, this cross-sectional study enrolled 30 SCA patients not receiving HU therapy (HbSS), 25 SCA patients receiving HU therapy (HbSS_HU), and 32 HbAA volunteers (HbAA). The IH markers evaluated were serum Lactate Dehydrogenase (LDH), total heme, plasma hemoglobin (pHb), and soluble CD163 (sCD163). The ED markers analyzed were plasma von Willebrand factor (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo) levels, antigen of VWF-cleaving protease (ADAMTS13:Ag), thrombospondin-1, endothelin-1 levels, and ADAMTS13 Activity (ADAMTS13:Act). The levels of VWF:Ag, VWF:RCo, total heme, thrombospondin-1, and endothelin-1 were significantly higher in SCA patients (HbSS and HbSS_HU) compared to HbAA individuals. Also, pHb, LDH, and thrombospondin-1 levels were significantly higher in the HbSS group than in the HbSS_HU group. Contrarily, the levels of sCD163, ADAMTS13:Ag, and ADAMTS13:Act were significantly lower in both groups of SCA patients than HbAA controls, and ADAMTS13:Act levels were significantly lower in HbSS compared to HbSS_HU patients. The higher ADAMTS13 activity levels in those on HU therapy may be attributed to lower pHb and thrombospondin-1 levels as previously shown by in vitro studies that thrombospondin-1 and pHb are bound to VWF. Thus, VWF is restrained from ADAMTS13 activity and cleavage.

Low expression of ZHX1 and ZHX2 impacts on the prognosis of chronic lymphocytic leukemia.

Experimental evidence points to the role of Zinc fingers and homeoboxes protein 1 and 2 (ZHX1 and ZHX2) in the development and progression of several types of cancer, including hematological malignancies. Here, we determined whether the altered expression of ZHX1 and ZHX2 has clinical implications in patients with CLL. Interestingly, CLL patients with low expression ZHX1 and ZHX2 presented higher WBC counts. Importantly, our data showed that CLL patients with cytogenetic alterations presented reduced transcriptional levels of ZHX1 and ZHX2 in comparison with patients with normal karyotype. Moreover, when stratifying CLL patients according to the karyotype prognosis value, we observed that the expression of ZHX1 and ZHX2 was significantly reduced in CLL patients presenting adverse karyotypes. Finally, we stratified patients according to the number of chromosomal aberrations and observed a negative association between ZHX1 and ZHX2 expression and the accumulation of chromosomal abnormalities in CLL patients. Our data showed that the low expression of ZHX1 and ZHX2 is associated with a worse prognosis in CLL, followed by a greater number of leukemic cells and unfavorable cytogenetics findings in the diagnosis. Further studies will be important to confirm the prognostic value of ZHX1 and ZHX2 in independent CLL cohorts.

Alpha thalassemia, but not ßS-globin haplotypes, influence sickle cell anemia clinical outcome in a large, single-center Brazilian cohort.

Alpha thalassemia and beta-globin haplotype are considered classical genetic disease modifiers in sickle cell anemia (SCA) causing clinical heterogeneity. Nevertheless, their functional impact on SCA disease emergence and progression remains elusive. To better understand the role of alpha thalassemia and beta-globin haplotype in SCA, we performed a retrospective study evaluating the clinical manifestations of 614 patients. The univariate analysis showed that the presence of alpha-thalassemia -3.7-kb mutation (αα/-α and -α/-α) decreased the risk of stroke development (p = 0.046), priapism (p = 0.033), and cholelithiasis (p = 0.021). Furthermore, the cumulative incidence of stroke (p = 0.023) and cholelithiasis (p = 0.006) was also significantly lower for patients carrying the alpha thalassemia -3.7-kb mutation. No clinical effects were associated with the beta-globin haplotype analysis, which could be explained by the relatively homogeneous haplotype composition in our cohort. Our results reinforce that alpha thalassemia can provide protective functions against hemolysis-related symptoms in SCA. Although, several genetic modifiers can impact the inflammatory state of SCA patients, the alpha thalassemia mutation remains one of the most recurrent genetic aberration and should therefore always be considered first.

Neutrophil extracellular trap regulators in sickle cell disease: Modulation of gene expression of PADI4, neutrophil elastase, and myeloperoxidase during vaso-occlusive crisis.

BACKGROUND: Recent evidence suggests that generation of neutrophil extracellular traps (NETosis), one of the components of immunothrombosis, is associated with the pathogenesis of both venous thromboembolism and sickle cell disease (SCD). NETosis is a complex process regulated by several proteins such as peptidyl arginine deaminase 4 (PADI4), neutrophil elastase (ELANE), and myeloperoxidase (MPO). Among these regulators, PADI4 is responsible of histone citrullination, an essential step for NETosis. Accordingly, its inhibition has been recently cited as a promising therapeutic strategy for diseases such as SCD. Although attractive, this strategy requires supportive evidence of its role in the pathogenesis of SCD. PATIENTS AND METHODS: Patients from two independent cohorts were enrolled in this study. Samples were obtained at steady state (53 patients) or during acute episodes of vaso-occlusive crisis (VOC; 28 patients) in patients from cohort 1. mRNA was extracted from granulocytes to analyze PADI4, ELANE, and MPO expression by qPCR. Furthermore, plasma activity of PADI4 was assessed from an independent cohort in 15 patients, within 24 hours from admission for VOC. Race-matched healthy individuals from the same geographic regions were used as controls for each cohort. RESULTS AND CONCLUSIONS: Higher levels of gene expression of PADI4 and ELANE were observed during VOC. Furthermore, plasma activity of PADI4 was higher in acute VOC when compared to healthy individuals. These results demonstrate that NETosis regulators are modulated during acute VOC, and pave the way for studies of PADI4 inhibition as a therapeutic strategy for acute VOC in SCD.

Endothelial Barrier Integrity Is Disrupted In Vitro by Heme and by Serum From Sickle Cell Disease Patients.

Free extracellular heme has been shown to activate several compartments of innate immunity, acting as a danger-associated molecular pattern (DAMP) in hemolytic diseases. Although localized endothelial barrier (EB) disruption is an important part of inflammation that allows circulating leukocytes to reach inflamed tissues, non-localized/deregulated disruption of the EB can lead to widespread microvascular hyperpermeability and secondary tissue damage. In mouse models of sickle cell disease (SCD), EB disruption has been associated with the development of a form of acute lung injury that closely resembles acute chest syndrome (ACS), and that can be elicited by acute heme infusion. Here we explored the effect of heme on EB integrity using human endothelial cell monolayers, in experimental conditions that include elements that more closely resemble in vivo conditions. EB integrity was assessed by electric cell-substrate impedance sensing in the presence of varying concentrations of heme and sera from SCD patients or healthy volunteers. Heme caused a dose-dependent decrease of the electrical resistance of cell monolayers, consistent with EB disruption, which was confirmed by staining of junction protein VE-cadherin. In addition, sera from SCD patients, but not from healthy volunteers, were also capable to induce EB disruption. Interestingly, these effects were not associated with total heme levels in serum. However, when heme was added to sera from SCD patients, but not from healthy volunteers, EB disruption could be elicited, and this effect was associated with hemopexin serum levels. Together our in vitro studies provide additional support to the concept of heme as a DAMP in hemolytic conditions.

Overexpression of UDP-Glucose 4-Epimerase Is Associated with Differentiation Grade of Gastric Cancer.

The UDP-glucose 4-epimerase (GALE) is a glycosyltransferase, which acts on protein and lipid glycosylation in normal and neoplastic cells. This study is aimed at investigating the differential tissue expression of GALE and its possible association with clinical-pathological parameters and the outcome of gastric adenocarcinoma patients. Seventy-one patients were evaluated in relation to GALE expression by immunohistochemistry. Our results showed that 48 (67.6%) patients were GALE positive and 23 (32.4%) negative. Positive staining was present on well-differentiated and moderate-differentiated histological grade of gastric adenocarcinomas (p < 0.0001). There was no significant association with outcome parameters (p > 0.05). Besides that, our results corroborated with the validation cohort analysis, where the expression of GALE mRNA was also associated with the histological grade (p < 0.001). These results suggest a possible use of this enzyme as a biomarker for well and moderately differentiated tumors.

PIP4K2A and PIP4K2C transcript levels are associated with cytogenetic risk and survival outcomes in acute myeloid leukemia.

Phosphoinositide signaling pathway orchestrates primordial molecular and cellular functions in both healthy and pathologic conditions. Phosphatidylinositol-5-phosphate 4-kinase type 2 lipid kinase (PIP4K2) family, which compromises PIP4K2A, PIP4K2B and PIP4K2C, has drawn the attention in human cancers. Particularly in hematological malignancies, PIP4K2A was already described as an essential protein for a malignant phenotype, although the clinical and biological impact of PIP4K2B and PIP4K2C proteins have not being explored in the same extent. In the present study, we investigated the impact on clinical outcomes and gene network of PIP4K2A, PIP4K2B and PIP4K2C mRNA transcripts in acute myeloid leukemia (AML) patients included in The Cancer Genome Atlas (2013) study. Our results indicate that PIP4K2A and PIP4K2C, but not PIP4K2B, mRNA levels were significantly reduced in AML patients assigned to the favorable risk group (p < 0.05) and low levels of PIP4K2A and PIP4K2C positively affect clinical outcomes of AML patients (p < 0.05). Gene set enrichment analyses indicate that the expression of PIP4K2 genes is associated with biological process such as signal transduction, metabolism of RNA and genomic instability related-gene sets. In summary, our study provides additional evidence of the involvement of members of the PIP4K2 family, in particular PIP4K2A and PIP4K2C, in AML.

Unraveling KDM4 histone demethylase expression and its association with adverse cytogenetic findings in chronic lymphocytic leukemia.

The acquisition of complex karyotypes is related to the progression of chronic lymphocytic leukemia (CLL) and patients with this condition have a poor prognosis. Despite recent advances in the classification of prognosis in CLL patients, understanding of the molecular mechanisms that lead to genomic instability and progression of this disease remains inadequate. Interestingly, dysregulated expression of KDM4 members is involved in the progression of several cancer types and plays a role in the DNA damage response; however, the gene expression profile and the importance of KDM4 members in CLL are still unknown. Here, we assessed the gene expression profile of KDM4A, KDM4B, and KDM4C in 59 CLL samples and investigated whether these histone demethylases have any influence on the prognostic markers of this leukemia. KDM4A gene expression was higher in CLL patients as compared with control samples. In contrast, CLL samples showed decreased levels of the KDM4B transcript in relation to control cases, and no difference was detected in KDM4C expression. Furthermore, patients with positive expression of ZAP-70 had lower expression of KDM4B and KDM4C as compared with ZAP-70-negative patients. More importantly, patients with low expression of these histone demethylases had higher leukemic cell numbers and displayed adverse cytogenetic findings and the acquisition of a complex karyotype. The present data clearly show that the expression of KDM4 members is dysregulated in CLL and impact the prognosis of this leukemia. These findings are useful for a better understanding of the impact of epigenetics on CLL progression.

GLP overexpression is associated with poor prognosis in Chronic Lymphocytic Leukemia and its inhibition induces leukemic cell death.

Background Heterodimeric methyltransferases GLP (EHMT1/KMT1D) and G9a (EHMT2/KMT1C) are two closely related enzymes that promote the monomethylation and dimethylation of histone H3 lysine 9. Dysregulation of their activity has been implicated in several types of human cancer. Patients and methods Here, in order to investigate whether GLP/G9a exerts any impact on Chronic Lymphocytic Leukemia (CLL), GLP/G9a expression levels were assessed in a cohort of 50 patients and the effects of their inhibition were verified for the viability of CLL cells. Also, qRT-PCR was used to investigate the transcriptional levels of GLP/G9a in CLL patients. In addition, patient samples were classified according to ZAP-70 protein expression by flow cytometry and according to karyotype integrity by cytogenetics analysis. Finally, a selective small molecule inhibitor for GLP/G9a was used to ascertain whether these methyltransferases influenced the viability of MEC-1 CLL cell lineage. Results mRNA analysis revealed that CLL samples had higher levels of GLP, but not G9a, when compared to non-leukemic controls. Interestingly, patients with unfavorable cytogenetics showed higher expression levels of GLP compared to patients with favorable karyotypes. More importantly, GLP/G9a inhibition markedly induced cell death in CLL cells. Conclusion Taken together, these results indicate that GLP is associated with a worse prognosis in CLL, and that the inhibition of GLP/G9a influences CLL cell viability. Altogether, the present data demonstrate that these methyltransferases can be potential markers for disease progression, as well as a promising epigenetic target for CLL treatment and the prevention of disease evolution.

Residual expression of SMYD2 and SMYD3 is associated with the acquisition of complex karyotype in chronic lymphocytic leukemia.

SET and MYND domain containing 2 (SMYD2) and the SET and MYND domain containing 3 (SMYD3) are the most studied and well-characterized members of SMYD family. It has been demonstrated that their altered expression is associated with the progression of several solid tumors. Nevertheless, whether these methyltransferases exert any impact in chronic lymphocytic leukemia (CLL) remains unknown. Here, we investigated the gene expression profile of SMYD2 and SMYD3 in 59 samples of CLL and 10 normal B cells. The obtained results were associated with white blood cells (WBC) and platelet counts, ZAP-70 protein expression, and cytogenetic analysis. We found that SMYD2 and SMYD3 are overexpressed in CLL patients and, interestingly, patients with residual expression of both genes presented a high WBC count and complex karyotype. Furthermore, a strong correlation between SMYD2 and SMYD3 gene expression was unveiled. Our data demonstrate the association of a residual expression of SMYD2 and SMYD3 with CLL progression indicators and suggests both genes are regulated by a common transcriptional control in this type of cancer. These results may provide the basis for the development of new therapeutic strategies to prevent CLL progression.

Overexpression of EZH2 associates with a poor prognosis in chronic lymphocytic leukemia.

EZH2, a histone methyltransferase, is overexpressed in several human tumors, but whether it exerts any impact in chronic lymphocytic leukemia (CLL) remains unknown. We used real time PCR to investigate the expression profile of EZH1 and EZH2 in 59 CLL patients, 10 samples of purified B-cells from healthy donors and 12 normal adult tissues. EZH2 was overexpressed in CLL patients and correlates with high white blood cell count, ZAP-70 expression and chromosomal abnormalities. EHZ1 expression does not correlate with CLL progression. EZH2 overexpression is related to a poor prognosis of CLL and could be a useful tool to assess its aggressiveness.

Mantle cell lymphoma harboring Burkitt's-like translocations presents differential expression of aurora kinase genes compared with others 8q abnormalities.

We compared the levels of AURKA and AURKB in 24 (mantle cell lymphoma) MCL patients harboring 8q abnormalities and its relationship with MYCC gene status. Two distinct subgroups were observed, in terms of MYCC expression. Except for the patients with Burkitt's-like translocation, none of the patients harboring 8q abnormalities, including balanced translocations or duplications of MYCC band, identified both by G-banding and SKY, showed differential expression levels of MYCC. These previous findings also reflected in the differential expression of AURKA and AURKB genes. We found that AURKA and AURKB mRNA were expressed at significantly higher levels in MCL patients harboring Burkitt's-like translocation, when compared to patients with 8q rearrangements. The high expression of aurora kinase genes is reported to be associated with some parameters of clinical oncologic aggressiveness, such as high histological grade, invasion and increased rates of metastasis in several types of cancers. It is possible that in MCL patients expressing abnormal levels of MYCC together with a high expression of AURKA might offer some resistant to the conventional therapy purposes. Thus, aurora kinase inhibitors may also be considered for this specific subgroup on MCL, whose aggressive clinical course resembles high-grade lymphoma.

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients.

BACKGROUND: Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannosebinding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. OBJECTIVE: The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. METHODS: Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. RESULTS: A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. CONCLUSION: To the authors' knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies.

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients

Background: Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannosebinding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. Objective: The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. Methods: Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. Results: A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. Conclusion: To the authors' knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies. .