Immunotherapy as a treatment modality for mucosal melanoma of the head and neck: A systematic review

Introduction:Mucosal melanoma (MM) is a rare disease, accounting for approximately 1.4% of all melanomas and only 0.03% of all new cancer diagnoses. Traditionally, it has been associated with a poor prognosis, with an overall 5-year survival rate of <25%. Progress in treatment has been hindered by its rarity and lack of evidence. However, studies on the treatment of subcutaneous melanoma with immunotherapy have demonstrated significant improvement in survival rates and have become a core part of oncological strategies. This paper discusses the revision of the evidence for the use of immunotherapy in the head and neck.Methods:This systematic review was conducted on January 19, 2019. The Medline and Embase databases were searched. In total, 509 articles were collated and screened. Inclusion criteria for the study included treatment-naive cohorts, cohorts with recurrent disease, primary outcomes with overall survival and disease-free survival at 5 years and at the longest follow-up, and studies of adults with MM in whom immunotherapy was reported as a treatment strategy. The exclusion criteria included duplicate papers, anatomical sites other than the head and neck, case reports, and those not published in English.Results:Fifty-two papers out of the 509 collated papers met the inclusion criteria. The results are shown as a comparison of yearly survival rates following different treatment modalities (immunotherapy vs nonimmunotherapy) at 2, 3, and 5 years. It was found that, with immunotherapy, survival rates at all intervals were higher than those without immunotherapy.Discussion:Immunotherapy outcomes in small studies have shown good data for increasing survival rates at yearly intervals in MM of the head and neck. Larger clinical trials are needed to accurately distinguish the efficacy and survival outcomes of immunotherapy when compared with treatment modalities, excluding immunotherapy. However, the ability to perform larger trials is limited by the rarity of MM of the head and neck.     

A murine model of neurofibromatosis type 1 tibial pseudarthrosis featuring proliferative fibrous tissue and osteoclast‐like cells

Neurofibromatosis type 1 (NF1) is a common genetic condition caused by mutations in the NF1 gene. Patients often suffer from tissue‐specific lesions associated with local double‐inactivation of NF1. In this study, we generated a novel fracture model to investigate the mechanism underlying congenital pseudarthrosis of the tibia (CPT) associated with NF1. We used a Cre‐expressing adenovirus (AdCre) to inactivate Nf1 in vitro in cultured osteoprogenitors and osteoblasts, and in vivo in the fracture callus of Nf1^flox/flox and Nf1^flox/? mice. The effects of the presence of Nf1^null cells were extensively examined. Cultured Nf1^null‐committed osteoprogenitors from neonatal calvaria failed to differentiate and express mature osteoblastic markers, even with recombinant bone morphogenetic protein‐2 (rhBMP‐2) treatment. Similarly, Nf1^null‐inducible osteoprogenitors obtained from Nf1 mouse muscle were also unresponsive to rhBMP‐2. In both closed and open fracture models in Nf1^flox/flox and Nf1^flox/? mice, local AdCre injection significantly impaired bone healing, with fracture union being <50% that of wild type controls. No significant difference was seen between Nf1^flox/flox and Nf1^flox/? mice. Histological analyses showed invasion of the Nf1^null fractures by fibrous and highly proliferative tissue. Mean amounts of fibrous tissue were increased upward of 10‐fold in Nf1^null fractures and bromodeoxyuridine (BrdU) staining in closed fractures showed increased numbers of proliferating cells. In Nf1^null fractures, tartrate‐resistant acid phosphatase–positive (TRAP+) cells were frequently observed within the fibrous tissue, not lining a bone surface. In summary, we report that local Nf1 deletion in a fracture callus is sufficient to impair bony union and recapitulate histological features of clinical CPT. Cell culture findings support the concept that Nf1 double inactivation impairs early osteoblastic differentiation. This model provides valuable insight into the pathobiology of the disease, and will be helpful for trialing therapeutic compounds. © 2012 American Society for Bone and Mineral Research     

Use of recombinant human parathyroid hormone in hypocalcemic cardiomyopathy

Hypocalcemia secondary to hypoparathyroidism is a rare cause of congestive heart failure. However, its early recognition and treatment lead to significant improvement in cardiac function. We report a middle-aged woman presenting with symptoms of heart failure with a serum calcium level of 3.7 mg/dl and a serum inorganic phosphate level of 17.6 mg/dl 22 years after subtotal thyroidectomy. Besides calcium and calcitriol supplementation, she was the first patient with severe hypocalcemic cardiomyopathy to be given off-label recombinant human parathyroid hormone (PTH) because of an elevated serum calcium-phosphate product. We discuss the management and outcome of the patient and then present a brief review of similar previously reported cases. We also describe the pivotal role of calcium ion and the potential role of PTH in maintaining myocardial contractility, effective natriuresis, and possible pathogenic mechanisms contributing to heart failure secondary to hypocalcemia and hypoparathyroidism.     

Further characterization of two sequiviruses infecting lettuce and development of specific RT-PCR primers

Summary. Lettuce mottle virus (LeMoV) and dandelion yellow mosaic virus (DaYMV) infect lettuce in South America and Europe, respectively. LeMoV and DaYMV possess isometric particles, occur at low concentrations in plants and have narrow host ranges. Partial genome sequences of both viruses were obtained using purified viral preparations and universal primers for members of the family Sequiviridae. DaYMV and LeMoV sequences were analyzed and showed identity with other members of the family. Universal primers that detect both viruses and specific primers for LeMoV and DaYMV were designed and used in RT-PCR-based diagnostic assays. These results provide the first molecular data on the LeMoV and DaYMV genomes and suggest that LeMoV is a member of the genus Sequivirus, probably distinct from DaYMV.     

A novel fluorometric assay for aldo-keto reductase 1C3 predicts metabolic activation of the nitrogen mustard prodrug PR-104A in human leukaemia cells

Aldo-keto reductase 1C3 (AKR1C3, EC 1.1.1.188) metabolises steroid hormones, prostaglandins and xenobiotics, and activates the dinitrobenzamide mustard prodrug PR-104A by reducing it to hydroxylamine PR-104H. Here, we describe a functional assay for AKR1C3 in cells using the fluorogenic probe coumberone (a substrate for all AKR1C isoforms) in conjunction with a specific inhibitor of AKR1C3, the morpholylurea SN34037. We use this assay to evaluate AKR1C3 activity and PR-104A sensitivity in human leukaemia cells. SN34037-sensitive reduction of coumberone to fluorescent coumberol correlated with AKR1C3 protein expression by immunoblotting in a panel of seven diverse human leukaemia cell lines, and with SN34037-sensitive reduction of PR-104A to PR-104H. SN34037 inhibited aerobic cytotoxicity of PR-104A in high-AKR1C3 TF1 erythroleukaemia cells, but not in low-AKR1C3 Nalm6 pre-B cell acute lymphocytic leukaemia (B-ALL) cells, although variation in PR-104H sensitivity confounded the relationship between AKR1C3 activity and PR-104A sensitivity across the cell line panel. AKR1C3 mRNA expression showed wide variation between leukaemia patients, with consistently higher levels in T-ALL than B-ALL. In short term cultures from patient-derived paediatric ALL xenografts, PR-104A was more potent in T-ALL than B-ALL lines, and PR-104A cytotoxicity was significantly inhibited by SN34037 in T-ALL but not B-ALL. Overall, the results demonstrate that SN34037-sensitive coumberone reduction provides a rapid and specific assay for AKR1C3 activity in cells, with potential utility for identifying PR-104A-responsive leukaemias. However, variations in PR-104H sensitivity indicate the need for additional biomarkers for patient stratification.