Profiling FLT3 Mutations in Mexican Acute Myeloid Leukemia Pediatric Patients: Impact on Overall Survival

Background: Acute myeloid leukemia (AML) is the second most frequent leukemia in childhood. The FLT3 gene participates in hematopoietic stem cell proliferation. FLT3 mutations are recurrent in AML and influence prognosis. In Mexican pediatric AML patients, FLT3 mutational profile, and their clinical impact have not been evaluated. Aim of the study: This study aimed to identify the profile of FLT3 mutations in pediatric patients with de novo AML and to assess their possible influence on overall survival (OS) and other clinical features. Methods: Massive parallel target sequencing of FLT3 was performed in 80 patients. Results: FLT3 mutations [internal tandem duplication (ITD) or tyrosine kinase domain (TKD)] were identified in 24% of them. OS was significantly lower in FLT3 POS cases than in FLT3 NEG (p = 0.03). The average OS for FLT3 POS was 1.2 vs. 2.2 years in FLT3 NEG. There were no significant differences in the children's sex, age, percentage of blasts in bone marrow aspirate, or white blood cell count in peripheral blood at diagnosis between both groups. No differences were identified stratifying by the mutational load (high > 0.4) or type of mutation. The negative effect of FLT3 mutations was also observed in patients with acute promyelocytic leukemia (APL). Conclusions: FLT3 mutational profile is described in Mexican pediatric AML patients for the first time. Mutated FLT3 negatively impacts the outcome of AML patients, even considering the APL group. The clinical benefit from treatment with tyrosine kinase inhibitors in the FLT3 POS pediatric patients needs to be assessed in clinical trials. FLT3 testing may contribute to better risk stratification in our pediatric AML patients.

Association between Active H. pylori Infection and Iron Deficiency Assessed by Serum Hepcidin Levels in School-Age Children

Hepcidin regulates iron metabolism. Its synthesis increases in infection and decreases in iron deficiency. The aim of this study was to evaluate the relationship between H. pylori infection and iron deficiency by levels of hepcidin in children. A total of 350 school-age children participated in this cross-sectional study. Determinations of serum ferritin, hemoglobin, hepcidin, C-reactive protein, and α-1-acid-glycoprotein were done. Active H. pylori infection was performed with a 13C-urea breath test. In schoolchildren without H. pylori infection, hepcidin was lower in those with iron deficiency compared to children with normal iron status (5.5 ng/mL vs. 8.2 ng/mL, p = 0.017); while in schoolchildren with H. pylori infection the levels of hepcidin tended to be higher, regardless of the iron nutritional status. Using multivariate analysis, the association between H. pylori infection and iron deficiency was different by hepcidin levels. The association between H. pylori and iron deficiency was not significant for lower values of hepcidin (Odds Ratio = 0.17; 95% Confidence Interval [CI] 0.02-1.44), while the same association was significant for higher values of hepcidin (OR = 2.84; CI 95% 1.32-6.09). This joint effect is reflected in the adjusted probabilities for iron deficiency: Individuals with H. pylori infection and higher levels of hepcidin had a probability of 0.24 (CI 95% 0.14-0.34) for iron deficiency, and this probability was 0.24 (CI 95% 0.14-0.33) in children without H. pylori infection and lower levels of hepcidin. In children with H. pylori infection and iron deficiency, the hepcidin synthesis is upregulated. The stimulus to the synthesis of hepcidin due to H. pylori infection is greater than the iron deficiency stimulus.

Importance of maternal diabetes on the chronological deregulation of the intrauterine development: an experimental study in rat

We investigated whether maternal diabetes induced in rats using streptozotocin (STZ) on Day 5 of pregnancy affects the intrauterine developmental timeline. A total of 30 pregnant Sprague-Dawley diabetic rats (DRs) and 20 control rats (CRs) were used to obtain 21-day fetuses (F21) and newborn (NB) pups. Gestational age, weight, and body size were recorded as were the maxillofacial morphometry and morphohistological characteristics of the limbs. In DRs, pregnancy continued for ∼1.7 days, and delivery occurred 23 days postcoitus (DPC). In this group, the number of pups was lower, and 13% had maxillofacial defects. F21 in the DR group had lower weights and were smaller; moreover, the morphological characteristics of the maxillofacial structures, derived from the neural crest, were discordant with their chronological gestational age, resembling 18- to 19-day-old fetuses. These deficiencies were counterbalanced in NB pups. We conclude that hyperglycemia, which results from maternal diabetes and precedes embryo implantation, deregulates the intrauterine developmental timeline, restricts embryo-fetal growth, and primarily delays the remodeling and maturation of the structures derived from neural crest cells.

Association of resistance to activated protein with the presence of Leiden and Cambridge Factor V mutations in Mexican patients with primary thrombophilia

BACKGROUND

Leiden and Cambridge factor V coagulation mutations and activated protein C resistance (RaPC) are alterations related with vein and artery thrombosis. In this study we aimed to determine whether RaPC is associated with the presence of Leiden and Cambridge mutation and the frequency of these mutations in the racially mestizo Mexican population.

METHODS

We included 150 Mexican patients with primary thrombophilia and 100 healthy subjects in this study. RaPC was determined using commercial methods and genotypes FV Leiden and FV Cambridge with PCR-RFLPs.

RESULTS

RaPC was positive in four patients and in one control individual; however, there was no presence of Leiden or Cambridge mutation in the studied group; thus, RaPC was not correlated with the presence of any of the studied mutations.

CONCLUSIONS

These results indicate that there are other primary or secondary causes different from those studied, which condition the presence of RaPC. Furthermore, the frequency obtained for RaPC in our thrombophilic population of racially mixed Mexicans is lower compared to that obtained in the Caucasian population, most probably because they are genetically different populations.

Ceramide promotes the death of human cervical tumor cells in the absence of biochemical and morphological markers of apoptosis

C8-ceramide, a synthetic cell-permeable analog of endogenous ceramides, interfered with cell proliferation, and was cytotoxic to papilloma virus-containing human cervix carcinoma cells, CALO, INBL, and HeLa, that match two clinical stages of tumor progression. C8-ceramide (3 microM) markedly reduced the tumor cell number after 48 h of treatment, an effect that endured even after the removal of C8-ceramide. The carcinoma cells showed morphologic changes, characteristic of necrosis and released lactate dehydrogenase (LDH). A biologically inactive analog C8-dihydro-ceramide had no effect on cell viability in any of the cell lines tested. Seventy-two hours after C8-ceramide treatment none of the biochemical and morphological markers characteristic of apoptosis: (a) nuclear chromatin condensation, (b) DNA fragmentation, (c) proteolysis of the caspase-3 substrate poly-(ADP-ribose)-polymerase (PARP), and (d) appearance of phosphatidylserine on the external cell membrane, were observed. C8-ceramide had no effect on human cervix fibroblasts and induced a mild reduction (30%) in the proliferation of normal human cervix epithelia and HeLa cells (IV-B metastatic stage). The cytotoxicity of C8-ceramide was restricted to CALO (early II-B) and INBL (IV-A non-metastatic) carcinoma cells. The possible application of ceramide in the treatment of early stages of cervical cancer is discussed.