Therapeutic targeting of CK2 in acute and chronic leukemias

Phosphorylation can regulate almost every property of a protein and is involved in all fundamental cellular processes. Thus, proper regulation of phosphorylation events is critical to the homeostatic functions of cell signaling. Indeed, deregulation of signaling pathways underlies many human diseases, including cancer.[1] The importance of phosphorylation makes protein kinases and phosphatases promising therapeutic targets for a wide variety of disorders.[2] CK2, formerly known as casein kinase II, was discovered in 1954, [3] although only recently, and especially over the last two decades, it has become one of the most studied protein kinases, due to its ubiquity, pleiotropy and constitutive activity. In particular, appreciation of its pleiotropy has completely changed our vision of CK2 biology, from an ordinary cell homeostasis-maintaining enzyme to a master kinase potentially implicated in many human physiological and pathological events. CK2 is responsible for about 25% of the phosphoproteome,[4] as it catalyzes the phosphorylation of >300 substrates.[5] This partly explains the CK2 interconnected roles that underlie its involvement in many signaling pathways. However, CK2 prevalent roles are promotion of cell growth and suppression of apoptosis. Accordingly, several lines of evidence support the notion that CK2 is a key player in the pathogenesis of cancer. High levels of CK2 transcript and protein expression, as well as increased kinase activity are associated with the pathological functions of CK2 in a number of neoplasias.[6] It was only over the last decade, after extensive analyses in solid tumors, that basic and translational studies have provided evidence for a pivotal role of CK2 in driving the growth of different blood cancers as well, although the first report demonstrating increased CK2 expression in acute myelogenous leukemia (AML) dates back to 1985.[7] Since then, CK2 overexpression/activity has been demonstrated in other hematological malignancies, including acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (CML). [8] With the notable exceptions of CML and pediatric ALL, many patients with leukemias still have a poor outcome, despite the development of protocols with optimized chemotherapy combinations. Insufficient response to first-line therapy and unsalvageable relapses present major therapeutic challenges. Moreover, chemotherapy, even if successful, could have deleterious long-term biological and psychological effects, especially in children.[9] Furthermore, CML patients can develop resistance to tyrosine kinase inhibitors (TKIs), while both primary chemoresistant and relapsed pediatric ALL cases still remain an unresolved issue.[9

Hand function in children with radial longitudinal deficiency

BACKGROUND: In children with hypoplasia or aplasia of the radius (radial longitudinal deficiency) manual activity limitations may be caused by several factors; a short and bowed forearm, radial deviation of the wrist, a non-functional or absent thumb, limited range of motion in the fingers and impaired grip strength. The present study investigates the relation between these variables and activity and participation in children with radial dysplasia. METHODS: Twenty children, age 4-17 years, with radial longitudinal dysplasia Bayne type II-IV were examined with focus on the International Classification of Functioning and Health, version for Children and Youth (ICF-CY) context. Body function/structure was evaluated by measures of range of motion, grip strength, sensibility and radiographic parameters. Activity was examined by Box and Block Test and Assisting Hand Assessment (AHA). Participation was assessed by Children's Hand-use Experience Questionnaire (CHEQ). Statistical correlations between assessments of body function/structure and activity as well as participation were examined. RESULTS: The mean total active motion of wrist (49.6°) and digits (447°) were less than norms. The mean hand forearm angle was 34° radially. Ulnar length ranged from 40 to 80% of age-related norms. Grip strength (mean 2.7 kg) and Box and Block Test (mean 33.8 blocks/minute) were considerably lower than for age-related norms. The mean score for the AHA was 55.9 and for CHEQ Grasp efficiency 69.3. The AHA had significant relationship with the total range of motion of digits (p = 0.042). Self-experienced time of performance (CHEQ Time) had significant relationship with total active motion of wrist (p = 0.043). Hand forearm angle did not show any significant relationship with Box and Block Test, AHA or CHEQ. CONCLUSION: In radial longitudinal deficiency total range of motion of digits and wrist may be of more cardinal importance to the child's activity and participation than the angulation of the wrist