Survival outcomes for patients with high-risk neuroblastoma (NB) have significantly improved with anti-disialoganglioside GD2 mAb therapy, which promotes NK cell activation through antibody-dependent cell-mediated cytotoxicity. NK cell activation requires an interaction between inhibitory killer cell immunoglobulin-like receptors (KIRs) and HLA class I ligands. NK cells lacking KIRs that are specific for self HLA are therefore "unlicensed" and hyporesponsive. mAb-treated NB patients lacking HLA class I ligands for their inhibitory KIRs have significantly higher survival rates, suggesting that NK cells expressing KIRs for non-self HLA are mediating tumor control in these individuals. We found that, in the presence of mAb, both licensed and unlicensed NK cells are highly activated in vitro. However, HLA class I expression on NB cell lines selectively inhibited licensed NK cell activity, permitting primarily unlicensed NK cells to mediate antibody-dependent cell-mediated cytotoxicity. These results indicate that unlicensed NK cells play a key antitumor role in patients undergoing mAb therapy via antibody-dependent cell-mediated cytotoxicity, thus explaining the potent "missing KIR ligand" benefit in patients with NB.

NUT Midline carcinoma (NMC) is a rare and invariably fatal poorly differentiated carcinoma characterized by chromosomal rearrangement involving the nuclear protein of the testis (NUT) gene. Current approaches do not provide durable response. We report a case of widely metastatic NMC in a 17-year-old female who, following an initial response to combination chemotherapy developed rapid disease progression. Treatment with vorinostat, a histone deacetylase inhibitor (HDACi) resulted in an objective response, yet she died in less than one year from initial diagnosis. This report shows a potentially promising activity of HDACi in the treatment of NMC that needs further exploration.

CSVT is an important complication of childhood ALL therapy. Postinduction combined asparaginase and dexamethasone intensive treatment for intermediate-/high-risk patients was the most important risk factor. Treatment with LMWH for a minimum of 3 months, and until asparginase therapy is over, with major radiological improvement seems to be effective and feasible.

This study presents the first pharmacogenetic analysis of vincristine-related peripheral neuropathy in children with ALL in an Arab country. We have shown that genetic polymorphisms in candidate genes are not associated with peripheral neuropathy secondary to chronic therapy with high-dose vincristine (2 mg/m) during the continuation phase. Concerning CEP72, our results are in line with the findings from the St Jude cohort of children treated for ALL with higher vincristine doses during chronic treatment. Larger high-throughput genetic analyses may be warranted to evaluate variants in other candidate genes such as CYP3A5 and reveal new nonpreviously reported alleles that may be peculiar to this region of the world.

This is the first report on the association of TPMT and NUDT15 polymorphisms with MP dose intolerance in Arab patients with ALL. Genotyping for additional polymorphisms may be warranted for potential gene/allele-dose effect.