We report the effect of UVA irradiation on collagen metabolism of fibroblasts, including both synthesis of the collagen degrading enzyme collagenase and de novo synthesis of type I collagen as the major structural component of the dermis. For this purpose confluent fibroblast monolayers were irradiated under standardized conditions (5, 15, 35, 60 J/cm2 using UVASUN 3000, Mutzhas, Munich, FRG, and UV source Sellas sunlight type 2.001, Sellas, Gevelsberg, FRG). Subsequently, total RNA was isolated and subjected to dot blot and northern blot analysis using oligolabelled cDNA clones for human type I collagen, collagenase and beta-actin. Collagen type I and beta-actin mRNA levels remained unaltered following irradiation, suggesting that the synthetic pathway of collagen metabolism at the pretranslational level is not affected by short-term UVA irradiation. However, collagenase mRNA was found to be dose-dependently induced in fibroblasts after irradiation, thus probably contributing to the actinic damage to the dermis. These in vitro data were confirmed in vivo using in situ hybridization on frozen sections of biopsy material obtained from UVA irradiated patients.

Cell cycle checkpoints are surveillance mechanisms that monitor and coordinate the order and ®delity of cell cycle events. When defects in the division program of a cell are detected, checkpoints prevent the pursuant cell cycle transition through regulation of the relevant cyclincdk complex(es). Checkpoints that respond to DNA damage have been described for the G1, S and G2 phases of the cell cycle. The p53 tumour suppressor is a key regulator of G1/S checkpoints, and can promote cell cycle delay or apoptosis in response to DNA damage. The importance of these events to cellular physiology is highlighted by the fact that tumours, in which p53 is frequently mutated, have widespread defects in the G1/S DNA damage checkpoints and a heightened level of genomic instability. G2/M DNA damage checkpoints have been de®ned by yeast genetics, though the genes in this response are conserved in mammals. We show here using biochemical and physiological assays that p53 is dispensable for a DNA damage checkpoint activated in the G2 phase of the cell cycle. Moreover, upregulation of p53 through serine 20 phosphorylation, does not occur in G2. Conversely, we show that the Chk1 protein kinase is essential for the human G2 DNA damage checkpoint. Importantly, inhibition of Chk1 in p53 de®cient cells greatly sensitizes them to radiation, validating the hypothesis of targeting Chk1 in rational drug design and development for anti-cancer therapies. Oncogene (2001) 20, 7453 ± 7463.

FDG PET scanning changed or influenced management decisions in 70 patients (67%) with NSCLC. Patients were frequently spared unnecessary treatment, and management was more appropriately targeted.

Our results support incorporation of PET/CT into the management paradigm of head and neck mucosal squamous cell carcinoma.

The role of transforming growth factor ,B2 (TGF-,B2) in the pathogenesis of systemic sclerosis (SSc) was investigated by in situ hybridization of skin biopsies from six patients with SSc.

Phaeochromocytomas (PCCs) and paragangliomas (PGLs) are rare neural crest-derived tumours originating from adrenal chromaffin cells or extra-adrenal sympathetic and parasympathetic tissues. More than a third of PCC/PGL cases are associated with heritable syndromes involving 13 or more known genes. These genes have been broadly partitioned into two groups based on pseudo-hypoxic and receptor tyrosine kinase (RTK) signalling pathways. Many of these genes can also become somatically mutated, although up to one third of sporadic cases have no known genetic driver. Furthermore, little is known of the genes that co-operate with known driver genes to initiate and drive tumourigenesis. To explore the genomic landscape of PCC/PGL, we applied exome sequencing, high-density SNP-array analysis, and RNA sequencing to 36 PCCs and four functional PGL tumours. All tumours displayed low mutation frequency, in contrast to frequent large segmental copy-number alterations, aneuploidy, and evidence for chromothripsis in one case. Multi-region sampling of one benign familial PCC tumour provided evidence for the timing of mutations during tumourigenesis and ongoing clonal evolution. Thirty-one of 40 (77.5%) cases could be explained by germline or somatic mutations or structural alterations affecting known PCC/PGL genes. Deleterious somatic mutations were also identified in known tumour-suppressor genes associated with genome maintenance and epigenetic modulation. A multitude of other genes were also found mutated that are likely important for normal neuroendocrine cell function. We revisited the gene-expression subtyping of PCC/PGL by integrating published microarray data with our RNA-seq data, enabling the identification of six robust gene-expression subtypes. The majority of cases in our cohort with no identifiable driver mutation were classified into a gene-expression subtype bearing similarity to MAX mutant PCC/PGL. Our data suggest there are yet unknown PCC/PGL cancer genes that can phenocopy MAX mutant PCC/PGL tumours. This study provides new insight into the molecular diversity and genetic origins of PCC/PGL tumours.

The retinoblastoma-predisposition gene, RBI, segregates as an autosomal dominant trait with high (90%) penetrance. Certain families, however, show an unusual low-penetrance phenotype with many individuals being unaffected, unilaterally affected, or with evidence of spontaneously regressed tumors. We have used single-strand conformation polymorphism analysis and PCR sequencing to study two such families. Mutations were found in exon 20 ofRB) in both cases.

GaTATE PET was positive in a high proportion of patients with refractory neuroblastoma, correlating with SSTR 2 on IHC, with additional disease identified compared with MIBG imaging. PRRT seems safe, feasible, with responses observed in patients with progression despite multimodality treatment. These data support ongoing clinical trials in such patients.