6007

RHD

CD240D|DIIIc|RH|RH30|RHCED|RHDVA(TT)|RHDel|RHPII|RHXIII|Rh4|RhDCw|RhII|RhK562-II|RhPI;Rh blood group, D antigen;RHD;Rh blood group, D antigen

D antigen (DCS)|RH polypeptide 2|Rh blood group antigen Evans|Rhesus system D polypeptide|blood group Rh(D) polypeptide|rhesus D antigen

1p36.11

protein-coding

Sarcomas, or tumors of connective tissue, represent roughly 20% of childhood cancers. Although the cure rate for sarcomas in general has significantly improved in the last 10 years, there continue to be subgroups that are difficultto treat. High-grade or metastatic soft-tissue sarcomas and rhabdomyosarcomas (RMS) of the extremities remain therapeutic challenges and their prognosis is often poor. The future of sarcoma therapy will likely include molecular approaches including gene/protein expression profiling and gene-based therapy. Most sarcomas harbor defects in the p53 or pRb pathways. The tumor suppressor p53 is central to regulation of cell growth and tumor suppression and restoring wild-type p53 function in pediatric sarcomas may be of therapeutic benefit. Studies with adenoviral-mediated p53 gene transfer have been conducted in many cancer types including cervical, ovarian, prostatic and head and neck tumors. Studies of this approach, however, remain limited in pediatric cancers, including sarcomas. Using three viral constructs containing cDNA for wild-type p53, mutantp53 (C135S) and lacZ, we studied the effect of adenoviral-mediated gene therapy in four pediatric sarcoma cell lines, RD and Rh4 (RMS), Rh1 (Ewing's sarcoma) and A204 (undifferentiated sarcoma). Using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, we have shown a dose-dependent decrease in cell viability 72 h post-treatment that occurs with Ad-wtp53 but not with Ad-mutp53. Cells treated with Ad-wtp53 show upregulation of the p53 downstream targets, p21(CIP1/WAF1) and bax. Growth curves demonstrate suppression of cell growth over a period of 4 days and cells treatedwith Ad-wtp53 demonstrate a significant increase in sensitivity to the chemotherapeutic agents, cisplatin and doxorubicin. Our results indicate that restoration of wild-type p53 function in pediatric sarcoma cells could provide abasis for novel approaches to treatment of this disease.

Anti-D immunoglobulin is a common front-line treatment for childhood immune thrombocytopenia (ITP) that typically results in a rapid and significant increase in platelet count. Unpredictable treatment responses and interpatient variability limit more widespread use. We hypothesized that anti-D response variability is influenced by RHD gene zygosity and erythrocyte D antigen expression. We compared RHD zygosity and quantitative D antigen expression to anti-D treatment results. Hemizygous RHD subjects demonstrated significantly higher platelet increases andpeak platelet counts than homozygous RHD subjects. Future studies should investigate the mechanisms by which RHD zygosity and D antigen expression affectplatelet responses to anti-D immunoglobulin. Pediatr Blood cancer 2013;60:E106-E108. (c) 2013 Wiley Periodicals, Inc.#CI- Copyright (c) 2013 Wiley Periodicals, Inc.