An oxidative stress-based mechanism of doxorubicin cytotoxicity suggests new therapeutic strategies in ABC-DLBCL.

Diffuse large B-cell lymphomas (DLBCLs) contain 2 major molecular subtypes; namely, the germinal center B-cell-like (GCB) and the activated B-cell-like (ABC) DLBCLs. It is well documented that ABC-DLBCL cases have a significantly poorer survival response than GCB-DLBCLs in both the CHOP (cyclophosphamide, vincristine, doxorubicin, and prednisone) and the rituximab (R)-CHOP eras. However, the underlying cause of this subtype disparity is poorly understood. Nevertheless, these clinical observations raise the possibility for an ABC-DLBCL-specific resistance mechanism that is directed toward 1 of the CHOP components and is inadequately addressed by rituximab. Here, we report that the main cytotoxic ingredient in CHOP, doxorubicin (Dox), has subtype-specific mechanisms of cytotoxicity in DLBCLs resulting from differences in the subcellular distribution pattern. Specifically, in cell line models of ABC-DLBCL, Dox is often enriched in the cytoplasm away from the nuclear DNA. As a result, Dox-induced cytotoxicity in ABC-DLBCLs is often dependent on oxidative stress, rather than DNA damage response. These findings are corroborated by gene signature analysis, which demonstrates that basal oxidative stress status predicts treatment outcome among patients with ABC-DLBCL, but not patients with GCB-DLBCL. In terms of redox-related resistance mechanism, our results suggest that STAT3 confers Dox resistance in ABC-DLBCLs by reinforcing an antioxidant program featuring upregulation of the SOD2 gene. Furthermore, a small-molecule STAT3 inhibitor synergizes with CHOP to trigger oxidative stress and kill ABC-DLBCL cells in preclinical models. These results provide a mechanistic basis for development of novel therapies that target either STAT3 or redox homeostasis to improve treatment outcomes for ABC-DLBCLs.

Pediatric primary splenic angiosarcoma: an aggressive multidisciplinary approach to the oncologic management of a rare malignancy.

Primary splenic angiosarcoma is an extremely rare and aggressive neoplasm of the vasculature. Uniformly, primary splenic angiosarcoma is a fatal disease despite early diagnosis and treatment. Only patients with localized disease amenable to surgical resection achieve long-term, disease-free survival. We present a review of the literature and report a case of a 3-year-old girl with metastatic primary splenic angiosarcoma who was offered aggressive surgical and medical treatment with curative intent despite her advanced presentation.

A pleiotropic recurrent dominant ITPR3 variant causes a complex multisystemic disease.

Inositol 1,4,5-trisphosphate (IP3) receptor type 1 (ITPR1), 2 (ITPR2), and 3 (ITPR3) encode the IP3 receptor (IP3R), a key player in intracellular calcium release. In four unrelated patients, we report that an identical ITPR3 de novo variant-NM_002224.3:c.7570C>T, p.Arg2524Cys-causes, through a dominant-negative effect, a complex multisystemic disorder with immunodeficiency. This leads to defective calcium homeostasis, mitochondrial malfunction, CD4+ lymphopenia, a quasi-absence of naïve CD4+ and CD8+ cells, an increase in memory cells, and a distinct TCR repertoire. The calcium defect was recapitulated in Jurkat knock-in. Site-directed mutagenesis displayed the exquisite sensitivity of Arg2524 to any amino acid change. Despite the fact that all patients had severe immunodeficiency, they also displayed variable multisystemic involvements, including ectodermal dysplasia, Charcot-Marie-Tooth disease, short stature, and bone marrow failure. In conclusion, unlike previously reported ITPR1-3 deficiencies leading to narrow, mainly neurological phenotypes, a recurrent dominant ITPR3 variant leads to a multisystemic disease, defining a unique role for IP3R3 in the tetrameric IP3R complex.

Iron Chelation Therapy With Deferasirox in Sickle Cell Disease With End-Stage Renal Disease.

Patients with transfusion-dependent sickle cell disease (SCD) are at risk of iron overload and its complications. Iron overload is a significant risk factor for chronic liver disease in patients who are dependent on hemodialysis secondary to end-stage renal disease (ESRD). Deferasirox is being increasingly used as an iron-chelating agent for the treatment of iron overload in both adults and children. There are limited reports on its use in pediatric patients with ESRD. Here, we discuss the use of deferasirox to treat iron overload in a 15-year-old male with SCD, ESRD from granulomatosis with polyangiitis, and dependent on hemodialysis. We also review the literature on similar uses of deferasirox in adult patients with ESRD.

How Should Primary Care Physicians Respond to Direct-to-Consumer Genetic Test Results?

In this case, a primary care physician is presented with direct-to-consumer genetic test results and asked to provide counseling and order follow-up diagnostics. In order to deal effectively with this situation, we suggest physicians need look no further than the practice principles that guide more routine clinical encounters. We examine the rationale behind 2 major clinical ethical considerations: (1) physicians have obligations to help their patients achieve reasonable health goals but are not obligated to perform procedures that are not medically indicated; and (2) primary care physicians do not need to know everything; they just need to know how to get their patients appropriate care.

Ethical considerations surrounding germline next-generation sequencing of children with cancer.

INTRODUCTION: The advent of next-generation sequencing (NGS) has introduced an exciting new era in biomedical research. NGS forms the foundation of current genetic testing approaches, including targeted gene panel testing, as well as more comprehensive whole-exome and whole-genome sequencing. Together, these approaches promise to provide critical insights into the understanding of health and disease. However, with NGS testing come many ethical questions and concerns, particularly when testing involves children. These concerns are especially relevant for children with cancer, where the testing of tumor and germline tissues is increasingly being incorporated into clinical care. Areas covered: In this manuscript, we explore the key ethical considerations related to conducting germline NGS testing in pediatric oncology, focusing on the four main principles of beneficence, non-maleficence, autonomy and justice. Expert commentary: The ethical issues surrounding germline NGS testing are complex and result in part from our limited understanding of the medical relevance of many of the results obtained and poor knowledge of the impacts of testing, both beneficial and detrimental, on patients and their families. In this article we discuss the risks and benefits of germline NGS testing and the arguments for and against such testing in children with cancer.