The Role of Caspase Genes Polymorphisms in Genetic Susceptibility to Philadelphia-Negative Myeloproliferative Neoplasms in a Portuguese Population.

Our main aim was to evaluate the role of caspases' genes SNPs in Philadelphia-chromosome negative chronic myeloproliferative neoplasms (PN-MPNs) susceptibility. A case-control study in 133 Caucasian Portuguese PN-MPNs patients and 281 matched controls was carried out, studying SNPs in apoptosis related caspases: rs1045485 and rs1035142 (CASP8), rs1052576, rs2308950, rs1132312 and rs1052571 (CASP9), rs2227309 and rs2227310 (CASP7) and rs13006529 (CASP10). After stratification by pathology diagnosis for essential thrombocythemia (ET), female gender or JAK2 positive, there is a significant increased risk for those carrying at least one variant allele for CASP9 (C653T) polymorphism (OR 2.300 CI 95% [1.180-4.484], P = 0.014). However, when considered individually, none of the studied caspases polymorphisms was associated with PN-MPNs risk. Our results do not reveal a significant involvement of caspase genes polymorphisms on the individual susceptibility towards PN-MPNs as a whole. However, for essential thrombocythemia (ET), female gender or JAK2 positive, there is a significant increased risk to those carrying at least one variant allele for CASP9. Although larger studies are required to confirm these results and to provide conclusive evidence of association between these and other caspases variants and PN-MPNs susceptibility, these new data may contribute to a best knowledge of the pathophysiology of these disorders and, in the future, to a more rational and efficient choice of therapeutic strategies to be adopted in PN-MPNs treatment.

Effects of polymorphic DNA genes involved in BER and caspase pathways on the clinical outcome of myeloproliferative neoplasms under treatment with hydroxyurea.

Several single nucleotide polymorphisms (SNPs) influencing DNA repair capacity and apoptotic status may confer genetic predisposition to Philadelphia­chromosome negative myeloproliferative neoplasms (PN­MPNs), and influence therapeutic response and the clinical course. In the present study, whether SNPs in genes involved in apoptosis and the base excision repair (BER) pathway was evaluated. In addition, some known risk factors in PN­MPNs that may influence survival and therapeutic response to hydroxyurea (HU) were analyzed, taking into account three items: Disease progression, predisposition to new non­myeloid neoplasms and thrombotic events. The present study involved a total of 133 Caucasian Portuguese PN­MPNs patients treated with HU, whereby 17 cases showed progression to myelofibrosis/leukemia, 11 developed new non­myeloid neoplasms and 22 presented with thrombotic events. Progression to secondary myelofibrosis/leukemia is influenced by exposure to cytoreductive agents, and caspase and BER polymorphisms {globally, CASP8 3'untranslated region [odds ratio (OR)=0.24; 95% confidence interval (CI), 0.08­0.69], XRCC1 Arg194Trp [OR=3.58; 95% CI, 0.98­13.01]; for essential thrombocythemia patients CASP9 Arg173His [OR=11.27; 95% CI, 1.13­112.28], APEX1 Asp148Glu [OR=0.28; 95% CI, 0.74­1.03], and XRCC1 Arg194Trp [OR=6.60; 95% CI, 1.60­27.06]}. Moreover, globally caspase and BER polymorphisms influenced the development of new nonmyeloid malignancies [CASP8 Asp270His (OR=5.90; 95% CI, 1.42­24.62) and XRCC1 Arg399Gln (OR=0.27; 95% CI, 0.07­1.03)]. On the other hand, only the BER pathway had a role in the presence of thrombotic events [XRCC1 Gln399Arg (OR=0.35; 95% CI, 0.14­0.88)]. JAK2 mutation had no influence on these complications. Larger studies are required to confirm these results, and to provide conclusive evidence of association between these and other variants with PN­MPNs therapeutic response and clinical evolution. However, this study may allow the development of drugs more directly targeted to the pathophysiology of the disease, with high efficacy, fewer adverse effects, contributing to compliance of patients with treatments. The clinical indication for classical drugs, including HU, may be guided by variant genes, which may provide additional beneficial effects.

Concomitant myeloproliferative and lymphoproliferative neoplasms, distinct progenitors: A case report and review of the literature.

Patients with a Philadelphia chromosome-negative myeloproliferative neoplasm may develop a lymphoproliferative disorder; however, the clinical and molecular determinants and the chronological onset of the two events remain unknown. We herein report the case of a 64-year-old man with concomitant diagnosis of high-risk essential thrombocythemia with evidence of a thrombotic event and high-count monoclonal B-cell lymphocytosis (high-count MBL). The patient harbored a JAK2V617F mutation and one of the most common genetic alterations found in chronic lymphocytic leukemia (CLL) (del 13q), which may represent a sign of disease progression. He was initiated on cytoreductive therapy with hydroxyurea 500 mg 3 times per week and hypocoagulation treatment, and is currently under regular surveillance of MBL without CLL criteria.

Concomitant presence of JAK2V617F mutation and BCR­ABL translocation in two patients: A new entity or a variant of myeloproliferative neoplasms (Case report).

Myeloproliferative neoplasms (MPNs) are classically divided into BCR RhoGEF and GTPase activating protein (BCR)-ABL proto­oncogene 1 non­receptor tyrosine kinase (ABL) positive chronic myeloid leukemia (CML) and BCR­ABL negative MPNs, including essential thrombocythemia (ET). One of the major diagnostic criteria for ET is the absence of the philadelphia chromosome, thus when present it is almost indicative of CML. ET and CML are considered to be mutually exclusive; however, there are rare situations in which patients with ET present positive BCR­ABL without the features of CML. Although from the literature review, the frequency of JAK2V617F mutation and BCR­ABL translocation coexistence in MPNs is low, it may be higher than expected. The current study reported cases of two patients with an initial diagnosis of ET in the presence of JAK2V617F mutation and BCR­ABL translocation by fluorescent in situ hybridization. Both patients presented with a heterozygous BCR­ABL translocation, and absence of p190 and p210 transcripts, seemingly a der(9) in the background of an ET JAK2V617F mutation.

DNA repair genes polymorphisms and genetic susceptibility to Philadelphia-negative myeloproliferative neoplasms in a Portuguese population: The role of base excision repair genes polymorphisms.

The role of base excision repair (BER) genes in Philadelphia-negative (PN)-myeloproliferative neoplasms (MPNs) susceptibility was evaluated by genotyping eight polymorphisms [apurinic/apyrimidinic endodeoxyribonuclease 1, mutY DNA glycosylase, earlier mutY homolog (E. coli) (MUTYH), 8-oxoguanine DNA glycosylase 1, poly (ADP-ribose) polymerase (PARP) 1, PARP4 and X-ray repair cross-complementing 1 (XRCC1)] in a case-control study involving 133 Caucasian Portuguese patients. The results did not reveal a correlation between individual BER polymorphisms and PN-MPNs when considered as a whole. However, stratification for essential thrombocythaemia revealed i) borderline effect/tendency to increased risk when carrying at least one variant allele for XRCC1_399 single-nucleotide polymorphism (SNP); ii) decreased risk for Janus kinase 2-positive patients carrying at least one variant allele for XRCC1_399 SNP; and iii) decreased risk in females carrying at least one variant allele for MUTYH SNP. Combination of alleles demonstrated an increased risk to PN-MPNs for one specific haplogroup. These findings may provide evidence for gene variants in susceptibility to MPNs. Indeed, common variants in DNA repair genes may hamper the capacity to repair DNA, thus increasing cancer susceptibility.

BCR-ABL V280G Mutation, Potential Role in Imatinib Resistance: First Case Report.

INTRODUCTION: The identification of BCR-ABL expression as the defining leukemogenic event in chronic myeloid leukemia (CML) and the introduction of BCR-ABL tyrosine kinase inhibitors in 2001 have revolutionized disease management, leading to a reduction in mortality rates and accordingly an increase in the estimated prevalence of CML. CASE REPORT: Based on medical records and clinical follow-up, the authors present the case of a Philadelphia chromosome-positive CML patient who developed resistance to imatinib. Quantitative reverse transcription-polymerase chain reaction testing revealed a V280G BCR-ABL mutation. DISCUSSION AND CONCLUSIONS: This is the first report describing a new BCR-ABL kinase domain mutation-V280G-that might be associated with resistance to imatinib. Approximately 15% to 30% of patients treated with imatinib discontinue treatment due to resistance or intolerance. More than 90 BCR-ABL mutations were detected so far, conferring variable degrees of drug resistance, with consequent clinical, therapeutic, and prognostic impact.

Usage of Running Drills in an Interval Training Program: Implications Related to Biomechanical Parameters of Running.

The purpose of this study was to investigate the effects of running drills during an interval training program on biomechanical parameters of running. Thirty recreational runners, divided into 2 groups (control group and experimental group [EG]), were submitted to a 15-week interval training, but only EG performed running drills in the training. The test sessions were accomplished before and after intervention. Spatiotemporal and kinetic variables were analyzed at 2 speeds: maximum (Smax) and comfortable (Scomf). For moment effect, significant increases were observed for Scomf (8.9%) and Smax (10.7%) after training. Variables related to mechanical load were also higher after training for both speeds (LR1: 16.4% and Imp75: 7.8% at Scomf; LR1: 21.4% and Imp75: 8.1% at Smax). For training approach effect, higher value of Imp75 was observed in EG (10.1% at Scomf and 11.9% at Smax, without performance improvements). Also, EG presented higher values of Fy2 (6.7% at Scomf and 6.1% at Smax) and FT (13.3% at Scomf), variables related to the center of mass oscillation. As a conclusion, including running drills in a 15-week interval running training seems not to be an efficient procedure to improve parameters related to mechanical load and performance.

Abbreviated (12-hour) versus traditional (24-hour) postpartum magnesium sulfate therapy in severe pre-eclampsia.

OBJECTIVE: To compare the use of magnesium sulfate for 12 hours versus 24 hours in postpartum women with stable severe pre-eclampsia. METHODS: In 2011, an open randomized clinical trial was conducted with 120 postpartum women with severe pre-eclampsia who gave birth at a tertiary hospital in Brazil; 60 women received magnesium sulfate for 24 hours and 60 for 12 hours. The analysis was by intention-to-treat and the intervention was not masked. RESULTS: Abbreviated (12-hour) magnesium sulfate therapy was associated with less exposure to the drug, and clinical outcomes were similar in both groups. No woman developed eclampsia and there was no need to re-initiate treatment after completing the scheduled magnesium sulfate therapy in either group. Magnesium sulfate therapy was extended in only three women in the 12-hour group. In addition, in this group, significant reductions were found in the duration of postpartum use of an indwelling bladder catheter, the time to ambulation, and the time to maternal contact with the newborn. CONCLUSION: Abbreviated postpartum magnesium sulfate therapy in patients with stable severe pre-eclampsia was associated with less drug exposure, similar outcomes, and benefits such as a reduction in the time to contact with the newborn. CLINICAL TRIALS REGISTRATION: clinicaltrials.gov NCT1408979.

The role of CCNH Val270Ala (rs2230641) and other nucleotide excision repair polymorphisms in individual susceptibility to well-differentiated thyroid cancer.

Well-differentiated thyroid cancer (DTC) is the most common form of thyroid cancer (TC); however, with the exception of radiation exposure, its etiology remains largely unknown. Several single nucleotide polymorphisms (SNPs) have previously been implicated in DTC risk. Nucleotide excision repair (NER) polymorphisms, despite having been associated with cancer risk at other locations, have received little attention in the context of thyroid carcinogenesis. In order to evaluate the role of NER pathway SNPs in DTC susceptibility, we performed a case-control study in 106 Caucasian Portuguese DTC patients and 212 matched controls. rs2230641 (CCNH), rs2972388 (CDK7), rs1805329 (RAD23B), rs3212986 (ERCC1), rs1800067 (ERCC4), rs17655, rs2227869 (ERCC5), rs4253211 and rs2228529 (ERCC6) were genotyped using TaqMan® methodology, while conventional PCR-RFLP was employed for rs2228000 and rs2228001 (XPC). When considering all DTC cases, only rs2230641 (CCNH) was associated with DTC risk; a consistent increase in overall DTC risk was observed for both the heterozygous genotype (OR=1.89, 95% CI=1.14-3.14) and the variant allele carriers (OR=1.79, 95% CI=1.09-2.93). Histological stratification analysis confirmed an identical effect on follicular TC (OR=2.72, 95% CI=1.19-6.22, for heterozygous; OR=2.44, 95% CI=1.07­5.55, for variant allele carriers). Considering papillary TC, the rs2228001 (XPC) variant genotype was associated with increased risk (OR=2.33, 95% CI=1.05-5.16), while a protective effect was observed for rs2227869 (ERCC5) (OR=0.26, 95% CI=0.08­0.90, for heterozygous; OR=0.25, 95% CI=0.07-0.86, for variant allele carriers). No further significant results were observed. Our results suggest that NER polymorphisms such as rs2230641 (CCNH) and, possibly, rs2227869 (ERCC5) and rs2228001 (XPC), may influence DTC susceptibility. However, larger studies are required to confirm these results.

Association of common variants in mismatch repair genes and breast cancer susceptibility: a multigene study.

BACKGROUND: MMR is responsible for the repair of base-base mismatches and insertion/deletion loops. Besides this, MMR is also associated with an anti-recombination function, suppressing homologous recombination. Losses of heterozygosity and/or microsatellite instability have been detected in a large number of skin samples from breast cancer patients, suggesting a potential role of MMR in breast cancer susceptibility. METHODS: We carried out a hospital-based case-control study in a Caucasian Portuguese population (287 cases and 547 controls) to estimate the susceptibility to non-familial breast cancer associated with some polymorphisms in mismatch repair genes (MSH3, MSH4, MSH6, MLH1, MLH3, PMS1 and MUTYH). RESULTS: Using unconditional logistic regression we found that MLH3 (L844P, G>A) polymorphism GA (Leu/Pro) and AA (Pro/Pro) genotypes were associated with a decreased risk: OR = 0.65 (0.45-0.95) (p = 0.03) and OR = 0.62 (0.41-0.94) (p = 0.03), respectively.Analysis of two-way SNP interaction effects on breast cancer revealed two potential associations to breast cancer susceptibility: MSH3 Ala1045Thr/MSH6 Gly39Glu - AA/TC [OR = 0.43 (0.21-0.83), p = 0.01] associated with a decreased risk; and MSH4 Ala97Thr/MLH3 Leu844Pro - AG/AA [OR = 2.35 (1.23-4.49), p = 0.01], GG/AA [OR = 2.11 (1.12-3,98), p = 0.02], and GG/AG [adjusted OR = 1.88 (1.12-3.15), p = 0.02] all associated with an increased risk for breast cancer. CONCLUSION: It is possible that some of these common variants in MMR genes contribute significantly to breast cancer susceptibility. However, further studies with a large sample size will be needed to support our results.