Severe combined immunodeficiency (SCID) comprises a heterogeneous group of primary immunodeficiencies, a proportion of which are due to mutations in either of the 2 recombination activating genes (RAG)-1 and -2, which mediate the process of V(D)J recombination leading to the assembly of antigen receptor genes. It is reported here that the clinical and immunologic phenotypes of patients bearing mutations in RAGs are more diverse than previously thought and that this variability is related, in part, to the specific type of RAG mutation. By analyzing 44 such patients from 41 families, the following conclusions were reached: (1) null mutations on both alleles lead to the T-B-SCID phenotype; (2) patients manifesting classic Omenn syndrome (OS) have missense mutations on at least one allele and maintain partial V(D)J recombination activity, which accounts for the generation of residual, oligoclonal T-lymphocytes; (3) in a third group of patients, findings were only partially compatible with OS, and these patients, who also carried at least one missense mutation, may be considered to have atypical SCID/OS; (4) patients with engraftment of maternal T cells as a complication of a transplacental transfusion represented a fourth group, and these patients, who often presented with a clinical phenotype mimicking OS, may be observed regardless of the type of RAG gene mutation. Analysis of the RAG genes by direct sequencing is an effective way to provide accurate diagnosis of RAG-deficient as opposed to RAG-independent V(D)J recombination defects, a distinction that cannot be made based on clinical and immunologic phenotype alone.

Background: The purpose of this study was to confirm sunitinib activity in alveolar soft part sarcoma (ASPS) and to report on new insights into the molecular bases thereof. Patients and methods: From July 2007, nine patients with progressive metastatic ASPS received sunitinib 37.5 mg/day, within a named use program. Cryopreserved material was available for five naive patients, among whom three received sunitinib. Immunofluorescence (IF)/confocal microscopy, biochemical, and molecular/cytogenetic analyses were carried out, complemented by antiproliferative and activation assays in a short-term culture derived from one case. Results: All patients were eligible for response. Best RECIST response was partial response in five cases, stable disease in three, and progression in one. The median progression-free survival was 17 months. Positron emission tomography results were consistent. Two cases of interval progressions were recorded. Antiproliferative assays and biochemistry on short-term culture showed that sunitinib is able to markedly impair ASPS cells growth and switch-off PDGFRB. IF/confocal microscopy demonstrated coexpression and physical association between PDGFRB/vascular endothelial growth factor receptor 2 (VEGFR2) and RET/VEGFR2 in ASPS cells, which was validated by biochemistry. PDGFRB, RET, and MET ligand-dependent activation was confirmed. Conclusions: We confirm the clinical efficacy of sunitinib in ASPS, mediated by PDGFRB, VEGFR2, and RET, which are all expressed in tumor cells. A direct antitumor effect was shown in a short-term cell culture.

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase predominantly expressed in the developing nervous system. Recently, mutated ALK has been identified as a major oncogene associated with familial and sporadic neuroblastomas (NBL). Yet, a direct correlation between endogenous expression level of the ALK protein, oncogenic potential, and clinical outcome has not been established. We investigated ALK genetic mutations, protein expression/phosphorylation, and functional inhibition both in NBL-derived cell lines and in 34 localized and 48 advanced/metastatic NBL patients. ALK constitutive phosphorylation/activation was observed in high-ALK expressing cells, harboring either a mutated or a wild-type receptor. No activation was found in cell lines with low expression of wild-type ALK. After 72 hours of treatments, small molecule ALK inhibitor CEP-14083 (60 nmol/L) induced growth arrest and cell death in NBL cells overexpressing wild-type (viability: ALK^high 12.8%, ALK^low 73%, P = 0.0035; cell death: ALK^high 56.4%, ALK^low 16.2%, P = 0.0001) or mutated ALK. ALK protein expression was significantly up-regulated in advanced/metastatic compared with localized NBLs (ALK overexpressing patients: stage 1-2, 23.5%; stage 3-4, 77%; P < 0.0001). Interestingly, protein levels did not always correlate with ALK genetic alterations and/or mRNA abundance. Both mutated and wild-type ALK receptor can exert oncogenic activity in NBL cells. However, wild-type ALK receptor requires a critical threshold of expression to achieve oncogenic activation. Overexpression of either mutated or wild-type ALK defines poor prognosis patients. Alternative mechanisms other than direct mutations and/or gene amplification regulate the ALK level of expression in NBL cells. Wild-type ALK is a potential therapeutic target for advanced/metastatic NBLs. [Cancer Res 2009;69(18):7338–46]

To report on a prospective, investigator-driven, phase II study on lapatinib in epidermal growth factor receptor (EGFR)-positive advanced chordoma patients. From December 2009 to January 2012, 18 advanced progressing chordoma patients entered this study (median age: 61 years; disease extent: metastatic 72% and locally advanced 28%). Epidermal growth factor receptor (EGFR) expression and activation were evaluated by immunohistochemistry and/or phospho-arrays, real-time polimerase chain reaction, fluorescence immunostaining. Fluorescence in situ hybridization analysis was also carried out. Patients received lapatinib 1500 mg/day (mean dose intensity = 1282 mg/day), until progression or toxicity. The primary study end point was response rate (RR) as per Choi criteria. Secondary end points were RR by Response Evaluation Criteria in Solid Tumor (RECIST), overall survival, progression-free survival (PFS) and clinical benefit rate (CBR; RECIST complete response + partial response (PR) + stable disease (SD) ≥ 6 months). All patients were evaluable for response. Six (33.3%) patients had PR and 7 (38.9%) SD, as their best Choi responses, corresponding to RECIST SD in all cases. Median PFS by Choi was 6 [interquartile (IQ) range 3–8] months. Median PFS by RECIST was 8 (IQ range 4–12) months, with a 22% CBR. This phase II study showed a modest antitumor activity of lapatinib in chordoma. The clinical exploitation of EGFR targeting in chordoma needs to be further investigated, both clinically and preclinically. Clinical trial Registration No: EU Clinical Trials Register trial no. 2009-014456-29.