Platinum Complexes Can Bind to Telomeres by Coordination.

It is suggested that several compounds, including G-quadruplex ligands, can target telomeres, inducing their uncapping and, ultimately, cell death. However, it has never been demonstrated whether such ligands can bind directly and quantitatively to telomeres. Here, we employed the property of platinum and platinum-G-quadruplex complexes to target G-rich sequences to investigate and quantify their covalent binding to telomeres. Using inductively coupled plasma mass spectrometry, surprisingly, we found that, in cellulo, in the presence of cisplatin, a di-functional platinum complex, telomeric DNA was platinated 13-times less than genomic DNA in cellulo, as compared to in vitro data. On the contrary, the amount of mono-functional platinum complexes (Pt-ttpy and Pt-tpy) bound either to telomeric or to genomic DNA was similar and occurred in a G-quadruplex independent-manner. Importantly, the quantification revealed that the low level of cisplatin bound to telomeric DNA could not be the direct physical cause of TRF2 displacement from telomeres. Altogether, our data suggest that platinum complexes can affect telomeres both directly and indirectly.

Disseminated Bacillus Calmette-Guérin Osteomyelitis in Twin Sisters Related to STAT1 Gene Deficiency.

Mendelian susceptibility to mycobacterial disease is a rare syndrome characterized by severe clinical infections usually caused by weakly virulent mycobacterial species such as Bacillus Calmette-Guérin vaccines and environmental nontuberculous mycobacteria or more virulent mycobacteria as mycobacterium tuberculosis. Since 1996, 9 genes including 7 autosomal ( STAT1, IFNGR1, IFNGR2, IL12B, IL12RB1, ISG15, and IRF8) and 2 X-linked genes ( NEMO and CYBB) have been identified. Allelic heterogeneity leaded to recognize about 18 genetic diseases with variable clinical phenotypes, but sharing a same physiological mechanism represented by a defect in human IL-12-dependant-INF-γ-mediated immunity. We report here a case of multifocal Bacillus Calmette-Guérin osteomyelitis in a context Mendelian susceptibility to mycobacterial disease mimicking a metastatic neuroblastoma in a child presenting with delayed growth. The investigation of her twin sister showed the same disease. A heterozygous mutation in exon 22 of STAT1 gene was found in both sisters, another sister and the father being healthy and heterozygous for the same mutation.

WT1 expression is inversely correlated with MYCN amplification or expression and associated with poor survival in non-MYCN-amplified neuroblastoma.

Neuroblastoma (NB) is the most common extra cranial solid tumor in childhood and the most frequently diagnosed neoplasm during infancy. A striking feature of this tumor is its clinical heterogeneity. Several tumor progression markers have been delineated so far, among which MYCN amplification, which occurs in about 25% of total NB cases, with the percentage increasing to 30% in advanced stage NB. Although MYCN amplification is strongly correlated with NB of poor outcome, the MYCN status cannot alone predict all cases of poor survival in NB. Indeed NB without MYCN amplification (about 70-80% of NB) are not always favorable. WT1 was initially identified as a tumor suppressor gene involved in the development of a pediatric renal tumor (Wilms' tumor). Here, we describe an inverse correlation between WT1 expression and MYCN amplification and expression. However and most notably, our results show that WT1 gene expression is associated with a poor outcome for patients showing non-MYCN-amplified tumors. Thus WT1 expression is clinically significant in NB and may be a prognostic marker for better risk stratification and for an optimized therapeutic management of NB.

Head and neck squamous cell carcinoma in 13 patients with Fanconi anemia after hematopoietic stem cell transplantation.

BACKGROUND: Fanconi anemia (FA) is a chromosomal instability disorder with a very high risk of developing head and neck squamous cell carcinoma (HNSCC), most notably after hematopoietic stem cell transplantation (HSCT). METHODS: In the current study, the authors reported 13 cases of HNSCC in FA patients who underwent HSCT at the Saint Louis Hospital between 1976 and 2007. RESULTS: The median age of the patients at time of HSCT was 9.7 years. All patients received irradiation-based conditioning before HSCT and all developed extensive chronic graft versus host disease (GVHD). HNSCC was diagnosed at a median interval of 10 years after HSCT, mainly in numerous sites within the oral cavity (11 patients). Lymph node involvement was diagnosed in 4 patients. The TNM classification was: T1 in 6 patients, T2 in 2 patients, T3 in 2 patients, and T4 in 3 patients. Treatment was comprised of surgery in 10 patients, with clear surgical margins reported in 7 (including cervical lymph node dissection in 6 patients). Surgery was performed in addition to other treatments in only 2 patients (radiotherapy or cryotherapy). For the remaining 3 patients, treatment consisted in radiotherapy (2 patients) or chemotherapy (1 patient). Disease progression while receiving therapy was observed in 5 patients and 5 other patients developed disease recurrence between 3.5 and 23.7 months after treatment. Death occurred in 11 patients. At the time of last follow-up, only 2 patients were alive without any disease between 9 and 23 months after diagnosis. CONCLUSIONS: HNSCC developing in FA patients after HSCT is associated with a very poor prognosis. A systematic surveillance of the oral cavity is essential to permit early surgery, which to the authors' knowledge remains the only curative treatment for a minority of patients. It is very important to attempt to prevent this cancer by reducing chronic GVHD and using conditioning without irradiation.