Small MAF genes variants and chronic myeloid leukemia

Chronic myeloid leukemia (CML) is one of the most frequent hematological neoplasia worldwide. The abnormal accumulation of reactive oxygen species may be an important factor in CML development. The transcription factor NRF2 can regulate the transcription of a battery of antioxidant and detoxificant genes after heterodimerizing with small-Maf proteins. Although the participation of NRF2 in the development of chronic degenerative diseases has been thoroughly studied, the role of small-Maf genes has not been documented. We have identified polymorphisms in the three MAF genes (F, G and K) and assessed their association with CML. Over 266 subjects with CML and 399 unrelated healthy donors have been studied. After sequencing each MAF gene by Sanger technology, we found 17 variants in MAFF gene, eight in MAFG and seven in MAFK. In the case-control study, the homozygote genotype CC for the rs9610915 SNP of MAFF was significantly associated with CML. The frequency of the ACC haplotype from MAFK was significantly lower than controls. After stratification by gender, the ACC and GTG haplotypes were associated only with males with CML. These novel data suggest an association between MAFF and MAFG and the development of CML.

[National guidelines of diagnosis and treatment of the non-Hodgkin lymphoma]

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

[Current therapeutic advances in the treatment of non-Hodgkin lymphoma]

Lymphoma is a lymphoid cell cancer that originates in lymphoid tissues. Non Hodgkin (NHL) type represents 90% of cases. In Mexico, NHL constitutes the third most common cancer in males and the sixth among females. NHL treatment has achieved significant advances in the last decade and NHL is currently becoming a disease with a high probability of cure. Rituximab has become an alternative for the treatment of NHL. Rituximab is a monoclonal antibody that targets the CD20 antigen expressed in the mature malignant B cells. It induces NHL B cells destruction by complement-mediated citotoxicity, apoptosis and sensitization to the toxic effect of chemotherapy. Rituximab has revolutionized treatment results by offering patients with aggressive NHL a higher possibility of cure and in the case of the intractable forms of NHL it increases the disease free period. The standard treatment for a patient with NHL is rituximab-CHOP (immunotherapy). In addition, rituximab has pharmacoeconomic advantages as shown in various cost-utility and cost-effectiveness studies.

[Thalidomide-associated bradycardia in patients with hematologic diseases: a single institution experience]

Thalidomide, an immunomodulatory and antiangiogenic agent, is useful in the treatment of some hematologic and oncologic diseases. Up to 6.8% of thalidomide-treated patients present bradycardia. Herein the incidence of thalidomide-associated bradycardia in patients with hematologic diseases treated in a single institution is reported. In a 34-month period, 33 patients with different hematologic diseases (multiple myeloma [MM], 20; myelodysplastic syndrome, eight; Waldenström macroglobulinemia, two; non-Hodgkin's lymphoma, two; malignant histiocytosis, one) were treated with thalidomide. Of them, five (15.1%) had bradycardia, all with MM. Bradycardia was detected with a daily thalidomide dose ranging from 100 to 300 mg and the time patients received thalidomide before cardiac event went from one to 18 months. In all affected cases the electrocardiogram showed sinus bradycardia with cardiac frequency between 32 to 48 beats per minute. Time to normal cardiac beat recovery ranged from 12 to 21 days after thalidomide discontinuation. There were no fatalities due to thalidomide-associated bradycardia. It is concluded that: a) thalidomide-associated bradycardia was detected only in patients with MM, b) herein the incidence of bradycardia was higher as compared with other series, and c) in patients with MM thalidomide therapy must be prescribed with caution particularly in those with cardiovascular diseases of any etiology.

[Molecular basis of cancer]

Cancer is a group of diseases characterized by an autonomous proliferation of neoplastic cells which have a number of alterations, including mutations and genetic instability. Cellular functions are controlled by proteins, and because these proteins are encoded by DNA organized into genes, molecular studies have shown that cancer is a paradigm of acquired genetic disease. The process of protein production involves a cascade of several different steps, each with its attendant enzymes, which are also encoded by DNA and regulated by other proteins. Most steps in the process can be affected, eventually leading to an alteration in the amount or structure of proteins, which in turn affects cellular function. However, whereas cellular function may be altered by disturbance of one gene, malignant transformation is thought to require two or more abnormalities occurring in the same cell. Although there are mechanisms responsible for DNA maintenance and repair, the basic structure of DNA and the order of the nucleotide bases can be mutated. These mutations can be inherited or can occur sporadically, and can be present in all cells or only in the tumor cells. At the nucleotide level, these mutations can be substitutions, additions or deletions. Several of the oncogenes discussed below, including the p53, c-fms, and Ras genes, can be activated by point mutations that lead to aminoacid substitution in critical portions of the protein. This article examines the current concepts relating to cellular mechanism that underlie the molecular alterations that characterize the development of cancer.