Erin M. Guest

Licensed to elongate: a molecular mechanism for MLL-based leukaemogenesis.

The RNA polymerase II (Pol II) elongation factor (ELL) was the first translocation partner of mixed lineage leukaemia (MLL) for which a biochemical function was determined. It was therefore proposed that the regulation of the elongation stage of transcription could be fundamental to MLL-based leukaemogenesis. Recent studies have identified ELL complexed with several of the translocation partners of MLL in a transcriptional super elongation complex (SEC). These studies provide evidence for the importance of the regulation of Pol II elongation in disease pathogenesis and suggest that MLL chimaeras function by licensing Pol II transcription elongation without the appropriate checkpoints.

The super elongation complex family of RNA polymerase II elongation factors: gene target specificity and transcriptional output.

ABSTRACT The elongation stage of transcription is highly regulated in metazoans. We previously purified the AFF1- and AFF4-containing super elongation complex (SEC) as a major regulator of development and cancer pathogenesis. Here, we report the biochemical isolation of SEC-like 2 (SEC-L2) and SEC-like 3 (SEC-L3) containing AFF2 and AFF3 in association with P-TEFb, ENL/MLLT1, and AF9/MLLT3. The SEC family members demonstrate high levels of polymerase II (Pol II) C-terminal domain kinase activity; however, only SEC is required for the proper induction of the HSP70 gene upon stress. Genome-wide mRNA-Seq analyses demonstrated that SEC-L2 and SEC-L3 control the expression of different subsets of genes, while AFF4/SEC plays a more dominant role in rapid transcriptional induction in cells. MYC is one of the direct targets of AFF4/SEC, and SEC recruitment to the MYC gene regulates its expression in different cancer cells, including those in acute myeloid or lymphoid leukemia. These findings suggest that AFF4/SEC could be a potential therapeutic target for the treatment of leukemia or other cancers associated with MYC overexpression.

Gemtuzumab ozogamicin in infants with AML: Results from the Children’s Oncology Group trials AAML03P1 and AAML0531

To the editor: Infants younger than 1 year of age with acute myeloid leukemia (AML) often exhibit high-risk clinical and cytogenetic features.[1][1][⇓][2][⇓][3]-[4][4] They are also at increased risk of pulmonary and infectious toxicities, early death (ED), and treatment-related mortality (TRM

Childhood cancer for the primary care physician.

Childhood cancer is rare among childhood diseases and requires a high index of suspicion by the primary care physician to entertain the possibility of cancer when managing common childhood diseases. This article presents an overview of common pediatric cancers, their presentations, and how the primary care physician can work up patients whom they suspect have a malignancy. The goal is to help primary care doctors in early recognition and appropriate referral of patients, in order for patients to receive required specialized care in a timely manner.

Parental Perceptions of Obesity and Obesity Risk Associated With Childhood Acute Lymphoblastic Leukemia.

The prevalence of obesity and related comorbidities in survivors of childhood acute lymphoblastic leukemia (ALL) is well established and ranges anywhere from 29% to 69% depending on the study. We sought to explore the awareness of parents of survivors of childhood ALL regarding the increased risk of obesity and their perceptions regarding the overall health of their child. One hundred twenty-one parents of 99 survivors of pediatric ALL completed surveys regarding perceptions of obesity risk in survivors. Eighty percent of parents of overweight and obese survivors correctly identified their child as “a little overweight” or “overweight.” Few parents recalled discussing weight gain (21%) or obesity risk (36%) with their practitioner. Parents that did recall having these discussions and/or reported a decreased level of posttherapy activity in their child were more likely to be concerned about their child’s weight status. Improved awareness and education regarding the risk of obesity and associated comorbid conditions may provide an avenue for future prevention of obesity in survivors of pediatric ALL. Discussion and education regarding a healthy lifestyle, including proper diet and exercise, should be incorporated early in routine patient visits.

Hb LAKE TAPAWINGO (α46(CE4)Phe→Ser; HBA2:c.140T>C): A NEW UNSTABLE α CHAIN HEMOGLOBIN VARIANT ASSOCIATED WITH LOW SYSTEMIC ARTERIAL SATURATION

A new unstable α-globin variant was detected in a child with hypoxemia and anemia. The child’s mother was found to carry the same mutation. The hemoglobin (Hb) variant co-eluted with Hb A2 by cation exchange high performance liquid chromatography (HPLC) and appeared cathodal to Hb A and anodal to Hb F by isoelectric focusing. It represented less than 20% of the total Hb and was unstable by isopropanol testing. Gene sequencing identified a missense mutation on the α2 gene [HBA2:c.140T>C]. Oxygen dissociation and P50 test results were normal.