Fluid overload and acute kidney injury in children with tumor lysis syndrome.

AIM: Tumor lysis syndrome (TLS) is a common oncologic emergency among patients with pediatric hematologic malignancies. The mainstay of TLS management is aggressive intravenous hydration. However, the epidemiology of fluid overload (FO) and acute kidney injury (AKI) in this population is understudied. In this study, we aimed to describe the incidence, severity, and complications of FO and AKI among pediatric patients with TLS. METHODS: We completed a single-center retrospective cohort study of pediatric patients with a new diagnosis of hematologic malignancy over a 10-year period. Patients with TLS were analyzed in two groups based on the severity of AKI and FO. Charts were reviewed for complications associated with AKI and FO including hypoxemia, mechanical ventilation, hyponatremia, pulmonary edema, pediatric intensive care (PICU) admission, and need for renal replacement therapy (RRT). RESULTS: We analyzed 56 patients with TLS for FO and AKI. We found severe FO (≥10%) occurred in 35.7% (n = 20). PICU admission occurred in 35% of patients with severe FO compared to 8.3% in those with mild/moderate FO <10% (p = .013). Complications of hypoxemia (30% vs. 5.6%, p = .012) and pulmonary edema (25% vs. 2.8%, p = .010) were more common among those with severe FO. AKI occurred in 37.5% (n = 21) patients and resulted in a significant increase in PICU admission and requirement for RRT (p = .001 and <.001, respectively). CONCLUSION: Our results show FO and AKI are common, and often unrecognized complications of TLS associated with increased morbidity. Prospective, multicenter studies are needed to further dissect the burden of FO and AKI within this vulnerable population.

Modulator of apoptosis 1 (MOAP-1) is a tumor suppressor protein linked to the RASSF1A protein.

Modulator of apoptosis 1 (MOAP-1) is a BH3-like protein that plays key roles in cell death or apoptosis. It is an integral partner to the tumor suppressor protein, Ras association domain family 1A (RASSF1A), and functions to activate the Bcl-2 family pro-apoptotic protein Bax. Although RASSF1A is now considered a bona fide tumor suppressor protein, the role of MOAP-1 as a tumor suppressor protein has yet to be determined. In this study, we present several lines of evidence from cancer databases, immunoblotting of cancer cells, proliferation, and xenograft assays as well as DNA microarray analysis to demonstrate the role of MOAP-1 as a tumor suppressor protein. Frequent loss of MOAP-1 expression, in at least some cancers, appears to be attributed to mRNA down-regulation and the rapid proteasomal degradation of MOAP-1 that could be reversed utilizing the proteasome inhibitor MG132. Overexpression of MOAP-1 in several cancer cell lines resulted in reduced tumorigenesis and up-regulation of genes involved in cancer regulatory pathways that include apoptosis (p53, Fas, and MST1), DNA damage control (poly(ADP)-ribose polymerase and ataxia telangiectasia mutated), those within the cell metabolism (IR-α, IR-ß, and AMP-activated protein kinase), and a stabilizing effect on microtubules. The loss of RASSF1A (an upstream regulator of MOAP-1) is one of the earliest detectable epigenetically silenced tumor suppressor proteins in cancer, and we speculate that the additional loss of function of MOAP-1 may be a second hit to functionally compromise the RASSF1A/MOAP-1 death receptor-dependent pathway and drive tumorigenesis.