Aberrant MNX1 expression associated with t(7;12)(q36;p13) pediatric acute myeloid leukemia induces the disease through altering histone methylation

Certain subtypes of acute myeloid leukemia (AML) in children have inferior outcome, such as AML with translocation t(7;12)(q36;p13) leading to an MNX1::ETV6 fusion along with high expression of MNX1. We have identified the transforming event in this AML and possible ways of treatment. Retroviral expression of MNX1 was able to induce AML in mice, with similar gene expression and pathway enrichment to t(7;12) AML patient data. Importantly, this leukemia was only induced in immune incompetent mice using fetal but not adult hematopoietic stem and progenitor cells. The restriction in transforming capacity to cells from fetal liver is in alignment with t(7;12)(q36;p13) AML being mostly seen in infants. Expression of MNX1 led to increased histone 3 lysine 4 mono-, di- and trimethylation, reduction in H3K27me3, accompanied with changes in genome-wide chromatin accessibility and genome expression, likely mediated through MNX1 interaction with the methionine cycle and methyltransferases. MNX1 expression increased DNA damage, depletion of the Lin-/Sca1+/c-Kit+ population and skewing toward the myeloid lineage. These effects, together with leukemia development, were prevented by pre-treatment with the S-adenosylmethionine analog Sinefungin. In conclusion, we have shown the importance of MNX1 in development of AML with t(7;12), supporting a rationale for targeting MNX1 and downstream pathways.

The diagnostic value of cranial computed tomography in complicated eclampsia

Cranial CT scanning was performed in twenty-two patients with severe neurological complications secondary to eclampsia. All patients had repetitive and/or prolonged convulsions. In addition, three patients were in prolonged coma, and three had cortical blindness. One of the patients had central facial paresis, and two had hemiparesis. In seventeen patients, abnormal CT findings were identified. Diffuse cerebral edema was determined in four patients. The most frequent finding was bilateral low-density areas in the parietal and/or occipital lobes (7 cases). In three patients, CT revealed bilateral low-density areas in the basal ganglia. All women but three recovered completely. Two of the three patients who died had intracranial massive hemorrhage. Follow-up CT examinations demonstrated complete resolution of the low-density areas and slight cortical atrophy in three of four patients. Complete recovery of the patients associated with complete resolution of the low-density lesions suggested that these lesions corresponded to edema. We concluded that CT is useful in patients with complicated eclampsia because it may orientate management.