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We previously noted that melanomas developing in Cdk4 R24C/R24C ::Tyr-NRAS , Arf −/− ::Tyr-NRAS and Trp53 F/F ::Tyr-Cre(ER)::Tyr-NRAS mice exhibited differences in behaviour in vivo. We investigated this phenomenon using global gene expression profiling of lesions from the respective genotypes. While those from the Cdk4- and Arf -mutant mice exhibited similar profiles, the Trp53 F/F ::Tyr-Cre(ER)::Tyr-NRAS melanomas were strikingly different, showing relative down-regulation of melanocyte-related genes, and up-regulation of genes related to neural differentiation. Specifically, they highly expressed genes representative of the myelin-producing peripheral oligodendrite (Schwann cell) lineage, although histopathologically the lesions did not exhibit the classical features of schwannoma. As Schwann cell precursors can be a cellular origin of melanocytes, it is unsurprising that plasticity with respect to melanocyte-neural differentiation can occur in melanoma. What is surprising is the genotype proclivity. Comparison of gene expression signatures revealed that melanomas from the Trp53 -mutant mice show significant similarities with a subset of aggressive human melanomas with relatively low levels of MITF.

Introduction: ICAM-1 is a receptor for 90% of human rhinoviruses, and non-typeable Haemophilus influenzae, two major pathogens in COPD. Aims: We have investigated epithelial ICAM-1 expression in airways and alveoli in relation to smoking and CAL. Methods: We evaluated epithelial ICAM-1 expression in both large and small airways from resected tissue: 8 smokers with normal spirometry; 28 CAL patients (10 small airway dysfunction; 8 COPD-smokers; 10 COPD ex-smokers). Controls (NC): 15 normal airway/lung tissues. Immunostaining with anti-ICAM-1 monoclonal antibody was quantified with computerized image analysis. The percent and type of cells expressing ICAM-1 in large and small airway epithelium and alveolar type I and type II pneumocytes were enumerated, plus percentage of epithelial goblet and submucosal glands positive for ICAM-1. Results: A major increase in ICAM-1 expression in epithelial cells was found in both large (p Conclusion: Airway ICAM-1 expression is especially marked in the CAL group, which could be crucial in viral infection and secondary bacterial infections. The lung parenchyma ICAM-1 is less affected and only by smoking.

Amir Soltani,1 Eugene Haydn Walters,1,* David W Reid,1,2 Shakti Dhar Shukla,1 Kaosia Nowrin,1 Chris Ward,3 H Konrad Muller,1 Sukhwinder Singh Sohal1,4,* 1NHMRC Center of Research Excellence for Chronic Respiratory Disease, School of Medicine, University of Tasmania, Hobart, TAS, Australia; 2Iron Metabolism Laboratory, Queensland Institute of Medical Research, Brisbane, QLD, Australia; 3Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, UK; 4School of Health Sciences, University of Tasmania, Launceston, TAS, Australia *These authors contributed equally to this work Background: This study assessed the effects of inhaled corticosteroid (ICS) on airway vascular remodeling in chronic obstructive pulmonary disease (COPD). Methods: Thirty-four subjects with mild-to-moderate COPD were randomly allocated 2:1 to ICS or placebo treatment in a double-blinded clinical trial over 6 months. Available tissue was compared before and after treatment for vessel density, and expression of VEGF, TGF-β1, and TGF-β1-related phosphorylated transcription factors p-SMAD 2/3. This clinical trial has been registered and allocated with the Australian New Zealand Clinical Trials Registry (ANZCTR) on 17/10/2012 with reference number ACTRN12612001111864. Results: There were no significant baseline differences between treatment groups. With ICS, vessels and angiogenic factors did not change in hypervascular reticular basement membrane, but in the hypovascular lamina propria (LP), vessels increased and this had a proportionate effect on lung air trapping. There was modest evidence for a reduction in LP vessels staining for VEGF with ICS treatment, but a marked and significant reduction in p-SMAD 2/3 expression. Conclusion: Six-month high-dose ICS treatment had little effect on hypervascularity or angiogenic growth factors in the reticular basement membrane in COPD, but normalized hypovascularity in the LP, and this was physiologically relevant, though accompanied by a paradoxical reduction in growth factor expression. Keywords: airway remodeling, bronchial biopsy, COPD, inhaled corticosteroid, vascular remodeling&nbsp

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.

We report on a systematic analysis of genotype-specific melanocyte (MC) UVR responses in transgenic mouse melanoma models along with tumour penetrance and comparative histopathology. pRb or p53 pathway mutations cooperated with Nras(Q61K) to transform MCs. We previously reported that MCs migrate from the follicular outer root sheath into the epidermis after neonatal UVR. Here, we found that Arf or p53 loss markedly diminished this response. Despite this, mice carrying these mutations developed melanoma with very early age of onset after neonatal UVR. Cdk4(R24C) did not affect the MC migration. Instead, independent of UVR exposure, interfollicular dermal MCs were more prevalent in Cdk4(R24C) mice. Subsequently, in adulthood, these mutants developed dermal MC proliferations reminiscent of superficial congenital naevi. Two types of melanoma were observed in this model. The location and growth pattern of the first was consistent with derivation from the naevi, while the second appeared to be of deep dermal origin. In animals carrying the Arf or p53 defects, no naevi were detected, with all tumours ostensibly skipping the benign precursor stage in progression.

To further investigate the use of DNA repair-enhancing agents for skin cancer prevention, we treated Cdk4(R24C/R24C)/Nras(Q61K) mice topically with the T4 endonuclease V DNA repair enzyme (known as Dimericine) immediately prior to neonatal ultraviolet radiation (UVR) exposure, which has a powerful effect in exacerbating melanoma development in the mouse model. Dimericine has been shown to reduce the incidence of basal-cell and squamous cell carcinoma. Unexpectedly, we saw no difference in penetrance or age of onset of melanoma after neonatal UVR between Dimericine-treated and control animals, although the drug reduced DNA damage and cellular proliferation in the skin. Interestingly, epidermal melanocytes removed cyclobutane pyrimidine dimers (CPDs) more efficiently than surrounding keratinocytes. Our study indicates that neonatal UVR-initiated melanomas may be driven by mechanisms other than solely that of a large CPD load and/or their inefficient repair. This is further suggestive of different mechanisms by which UVR may enhance the transformation of keratinocytes and melanocytes.

Melanocytes respond to UVR not only by producing melanin, but also by proliferating. This is essentially a protective response. We have studied the melanocyte proliferative response after a single UVR exposure to neonatal mice. At 3 days post-UVR in wild-type neonates we observed a marked melanocyte activation not seen in adults. Melanocytes migrated to the epidermal basal layer, their numbers peaking at 3-5 days after UVR then diminishing. They appeared to emanate from the hair follicle, migrating to the epidermis via the outer root sheath. In melanoma-prone mice with melanocyte-specific overexpression of Hras(G12V), basal layer melanocytes were increased in size and dendricity compared to UVR-treated wild-type mice. Melanocytes in mice carrying a pRb pathway cell-cycle defect (oncogenic Cdk4(R24C)) did not show an enhanced response to UVR such as those carrying Hras(G12V). The exquisite sensitivity to UVR-induced proliferation and migration that characterizes neonatal mouse melanocytes may partly explain the utility of this form of exposure for inducing melanoma in mice that carry oncogenic mutations.

We previously showed that mice carrying an activated Cdk4 mutation together with melanocyte-specific mutant Hras (Cdk4(R24C/R24C)/TPras) develop melanoma spontaneously, but penetrance is increased and age of onset reduced after neonatal ultraviolet radiation (UVR) exposure. UVR-treated mice were more likely to develop multiple primary lesions, and these melanomas more often expressed Trp53, and less often expressed c-Myc, than melanomas from nonirradiated mice (Hacker et at., Cancer Res 2006;66:294652). These data suggest differences in mechanisms of tumorigenesis between melanomas developing spontaneously, or as a result of UVR exposure. To further delineate these differences, we compared global gene expression between spontaneous and UVR-induced melanomas from these mice using microarrays. We found 264 genes differentially expressed between these groups (ANOVA, p < 0.05). Selected candidate genes were validated using qRT-PCR, which confirmed upregulation of Gpr155 and Bmp7, and downregulation of Plag11, Akap12 and Il18 in UVR-induced mouse melanomas. In humans, epidemiological studies suggest that there may be 2 predominant pathways to melanoma development. One characterized by chronic UVR exposure and which leads mainly to melanomas on sun-exposed sites; the other associated with low UVR exposure and leading predominantly to melanomas on less-exposed body sites. We found by immunohistochemical analysis that, comparing a series of human melanomas from the head (a chronically sun-exposed site; N = 82) with a set from the trunk (an intermittently exposed site; N = 65), the prevalence of IL-18 expression was significantly lower in melanomas on the head (16%) than on truncal melanomas (34%, p = 0.011). We conclude that loss of IL-18 is a marker of UVR-induced melanoma, both in animal models and humans. (C) 2008 Wiley-Liss, Inc.

The neonatal immune environment and the events that occur during this time have profound effects for the adult period. While protective immune responses can develop, the neonatal immune system, particularly the skin immune system (SIS), tends to promote tolerance. With this information we undertook a number of studies to identify unique aspects of skin during the neonatal period. Proteomics revealed proteins uniquely expressed in neonatal, but not adult, skin (e.g. Stefin A, peroxiredoxins) and these may have implications in the development of SIS. Vitamin D was found to have a modulating role on SIS and this was apparent from the early neonatal period. Exposure of the neonatal skin to UV radiation altered the microenvironment resulting in the generation of regulatory T cells, which persisted in adult life. As the development of UV radiation-induced melanoma can occur following a single high dose (equivalent to burning in adults) to transgenic mice (hepatocyte growth factor/scatter factor or TPras) during the neonatal period, the early modulating events which lead to suppression may be relevant for the development of UV radiation-induced human melanoma. Any attempt to produce effective melanoma immunotherapy has to accommodate and overcome these barriers. Margaret Kripke's pioneering work on UV-induced immunosuppression still remains central to the understanding of the development of melanoma and how it frequently escapes the immune system.

One of the most remarkable aspects of Devil Facial Tumour Disease (DFTD) is its infectious nature, and for successful transmission it must avoid detection by the devil’s immune system. For this to occur, the devil either is severely immunosuppressed or factors produced by the tumor contribute to its avoidance of immune detection. An analysis of the devil’s immune system revealed the presence of normal-looking lymphoid organs and lymphoid cells. At a functional level the lymphocytes proliferated in response to mitogen stimulation. Subcutaneous injection of a cellular antigen produced a strong antibody response, providing compelling evidence that the devil has a competent immune system. Tumor cell analysis demonstrated that the tumor expresses the genes of the major histocompatibility complex; however, there was a limited diversity. Therefore, the most likely explanation for devil-to-devil transmission of DFTD is that the tumor is not recognized by the devil as “non-self” because of the limited genetic diversity. With its consistent morphology and relatively stable genome, this tumor would provide a reasonable target for a vaccine approach, provided the immune system can be coaxed into recognizing the tumor as “non-self.”

The role of ultraviolet (UV) radiation in the induction of nonmelanoma skin cancer is widely accepted, although its precise contribution to the development of primary cutaneous melanoma skin cancer requires further definition. We found that painting aloe emodin, a trihydroxyanthraquinone from Aloe barbadensis, in ethyl alcohol vehicle on the skin of mice in conjunction with exposure to UVB (280-320 nm) radiation results in the development of melanin-containing skin tumors. C3H/HeN mice were treated thrice weekly with aloe emodin in a 25% ethanol in water vehicle and exposed to 15 kJ/m2 UV radiation. Neither ethanol vehicle nor aloe emodin alone induced skin tumors in the absence of UV radiation. In two separate experiments, 20-30% of the mice treated with a combination of UV radiation and ethanol vehicle and 50-67% of the UV-irradiated animals given aloe emodin in ethanol vehicle developed primary cutaneous melanin-containing tumors. The diagnosis of melanoma was established using Fontana silver stain for melanin; these tumors were negative for vimentin and keratin. Melanin-containing melanosomes were observed by transmission electron microscopy in tumors diagnosed as melanomas. Although the mechanism of carcinogenesis in these mice is currently unknown, our findings have led to the development of the first facile murine model for the induction of primary melanoma. This model has the potential to clarify the role of UV radiation in the etiology of malignant melanoma.

Background: We previously reported that EMT is an active process in the large airways of smokers and patients with COPD. Objective: In this study we have investigated EMT biomarkers expression in small airways (SAs) compared to large airways (LAs) in subjects with chronic airflow limitation (CAL), and type of EMT, on the basis of vascularity. Methods: We evaluated Rbm fragmentation (core structural marker of EMT) and EMT-related mesenchymal biomarkers in SAs and LAs from resected lung tissue from 18 subjects with CAL and, 9 normal controls using immunohistochemistry. Tissues were stained for vimentin and N-cadherin (mesenchymal marker), S100A4 (fibroblast epitope). Epidermal growth factor receptor (EGFR) as a marker of epithelial activation and type-IV collagen for vessels. Results: There was significantly increased expression of EMT-related markers in SAs compared to control tissue: Rbm fragmentation (p Conclusions: EMT is active in SAs and related to small airway obstruction. We suggest that airway fibrosis is secondary to Type-2-EMT which is active in that compartment; in contrast Type-3-EMT is marked in LAs and may have implications for airway cancer.

Human melanoma susceptibility is often characterized by germ-line inactivating CDKN2A (INK4A/ARF) mutations, or mutations that activate CDK4 by preventing its binding to and inhibition by INK4A. We have previously shown that a single neonatal UV radiation (UVR) dose delivered to mice that carry melanocyte-specific activation of Hras (TPras) increases melanoma penetrance from 0% to 57%. Here, we report that activated Cdk4 cooperates with activated Hras to enhance susceptibility to melanoma in mice. Whereas UVR treatment failed to induce melanomas in Cdk4R24C/R24C mice, it greatly increased the penetrance and decreased the age of onset of melanoma development in Cdk4R24C/R24C/TPras animals compared with TPras alone. This increased penetrance was dependent on the threshold of Cdk4 activation as Cdk4R24C/+/TPras animals did not show an increase in UVR-induced melanoma penetrance compared with TPras alone. In addition, Cdk4R24C/R24C/TPras mice invariably developed multiple lesions, which occurred rarely in TPras mice. These results indicate that germ-line defects abrogating the pRb pathway may enhance UVR-induced melanoma. TPras and Cdk4R24C/R24C/TPras tumors were comparable histopathologically but the latter were larger and more aggressive and cultured cells derived from such melanomas were also larger and had higher levels of nuclear atypia. Moreover, the melanomas in Cdk4R24C/R24C/TPras mice, but not in TPras mice, readily metastasized to regional lymph nodes. Thus, it seems that in the mouse, Hras activation initiates UVR-induced melanoma development whereas the cell cycle defect introduced by mutant Cdk4 contributes to tumor progression, producing more aggressive, metastatic tumors. (Cancer Res 2006; 66(6): 2946-52)

Decreased major histocompatibility class II (MHCII) expression is associated with poor survival in diffuse large B-cell lymphoma (DLBCL). Immune-privileged site DLBCL (IP-DLBCL) patients reportedly have frequent large deletions at the MHCII locus whereas the mechanism of decreased expression in non-IP-DLBCL is unknown. Gene expression profiling data were used for correlation analyses between expression levels of MHCII genes with each other and their transcriptional regulator, CIITA. Comparative genomic hybridization (CGH) assessed chromosomal alterations at MHCII-related loci. Finally, a map was created of expression of genes that are telomeric, within, or centromeric to the MHCII locus. Correlation coefficients among MHCII genes ranged from 0.73 to 0.92, whereas those between adjacent and intervening genes were lower (-0.12 to 0.49). Correlations between MHCII and CIITA expression were higher (0.53 to 0.60) than between CIITA and neighboring genes (-0.05 to 0.22). In 23 MHCII(-) cases, CGH detected 2 losses and 2 gains at MHCII loci. Expression of genes telomeric, within, and centromeric to MHCII loci were near normal in most MHCII(-) cases. Large deletions of the MHCII locus are uncommon in non-IP-DLBCL, implicating altered transcription as the operative mechanism for decreased expression.

The function of the retinoblastoma tumour suppressor (Rb1), and the pocket protein family in general, has been implicated as an important focal point for deregulation in many of the molecular pathways mutated in melanoma. We have focused on the role of Rb1 in mouse melanocyte homeostasis using gene targeting and Cre/loxP mediated tissue-specific deletion. We show that constitutive Cre-mediated ablation of Rb1 exon 2 prevents the production of Rb1 and recapitulates the phenotype encountered in other Rb1 knockout mouse models. Mice with conditional melanocyte-specific ablation of Rb1 manifest overtly normal pigmentation and are bereft of melanocytic hyperproliferative defects or apoptosis-induced depigmentation. Histologically, these mice have melanocyte morphology and distribution comparable with control littermates. In contrast, Rb1-null melanocytes removed from their in vivo micro-environment and cultured in vitro display some of the characteristics associated with a transformed phenotype. They proliferate at a heightened rate when compared with control melanocytes and have a decreased requirement for mitogens. With progressive culture the cells depigment at relatively early passage and display a gross morphology which, whilst reminiscent of early passage melanocytes, is generally different to equivalent passage control cells. These results indicate that Rb1 is dispensable for in vivo melanocyte homeostasis when its ablation is targeted from the melanoblast stage onwards, however, when cultured in vitro, Rb1 loss increases melanocyte growth but the cells are not fully transformed.

The Leukemia and Lymphoma Molecular Profiling Project recently published results from DNA microarray analyses of 240 diffuse large B-cell lymphomas (DLBCLs). Four gene expression "signatures" were identified as correlated with patient outcome, including the major histocompatibility complex (MHC) class II genes (eg, HLA-DRA) which correlated with better survival. We further analyzed the effects of HLA-DRA on survival and correlated gene expression with protein status and tumor-infiltrating lymphocytes. The 5-year overall survival was 24% in the lowest 10% of HLA-DRA expression, 37% in the 10% to 25% group, 50% in the 25% to 50% group, and 55% for patients in the highest 50%. Further analysis demonstrated that the hazard ratio of death was a nonlinear function of HLA-DRA expression. Adjustment for the International Prognostic Index did not alter the impact of HLA-DRA on survival. Other MHC class II genes were found to predict survival similarly. Microarray HLA-DRA expression correlated with the presence or absence of human leukocyte antigen-DR (HLA-DR) protein in 20 of 22 cases assessed. Fewer tumor-infiltrating CD8(+) T cells were detected in MHC class II-negative cases compared with positive cases (2.8% versus 11.0%; P =.001), supporting the hypothesis that loss of tumor immunosurveillance has a devastating effect on patient outcome in DLBCL.

To assess the premise that genetically determined differences in susceptibility to UV-induced immunosuppression are reflected in UV carcinogenesis, we investigated UV skin cancer induction in two strains of reciprocal F1 hybrid mice CB6F1 males with high susceptibility to UV immunosuppression and a BALB/c X-chromosome and B6CF1 males with low susceptibility to UV immunosuppression and a C57BL/6 X-chromosome. Four experimental groups comprising both strains treated three times weekly with two UV regimens (daily doses incremented from 2.25 to 6 or 4.5 to 12 kJ per m2) were monitored for skin tumor development. Survival without a skin tumor differed over the four groups (p< 0.0001) and differed according to UV regimen within each strain (p

We used gene expression profiling to establish a molecular diagnosis of mantle cell lymphoma (MCL), to elucidate its pathogenesis, and to predict the length of survival of these patients. An MCL gene expression signature defined a large subset of MCLs that expressed cyclin D1 and a novel subset that lacked cyclin D1 expression. A precise measurement of tumor cell proliferation, provided by the expression of proliferation signature genes, identified patient subsets that differed by more than 5 years in median survival. Differences in cyclin D1 mRNA abundance synergized with INK4a/ARF locus deletions to dictate tumor proliferation rate and survival. We propose a quantitative model of the aberrant cell cycle regulation in MCL that provides a rationale for the design of cell cycle inhibitor therapy in this malignancy.

Anaplastic large-cell lymphoma (ALCL) is a heterogeneous process that may have a T-cell, B-cell, or indeterminant (null) phenotype and which may or may not express the anaplastic lymphoma kinase (ALK) oncoprotein. Because the clinical significance of these variants of ALCL is unclear, we evaluated the cases of ALCL-T/null and ALCL-B identified in the Non-Hodgkin's Lymphoma Classification Project. We evaluated 1,378 cases of non-Hodgkin's lymphoma (NHL), and a consensus diagnosis of ALCL-T/null was made in 33 patients (2.4%) with a diagnostic accuracy of 85%. Compared to 96 patients with other forms of peripheral T-cell lymphoma (PTCL), those with ALCL-T/null were significantly younger, less likely to have advanced-stage disease or bone marrow involvement, more likely to have a low International Prognostic Index score, and had a significantly better survival. Among those with ALCL-T/null, there were no significant differences in the clinical features or survival on the basis of ALK expression. A consensus diagnosis of ALCL-B was made in 15 patients (1.1%), and the diagnostic accuracy was 67%. However, compared to 366 patients with other forms of diffuse large B-cell lymphoma (DLBCL), those with ALCL-B were no different with regard to clinical features or survival. We conclude that patients with ALCL-T/null have favorable prognostic features and excellent survival and should be separated from those with other forms of PTCL for prognostic and therapeutic purposes. In contrast, patients with ALCL-B appear to be similar to those with other forms of DLBCL.

Skin cells containing excessive ultraviolet (UV) radiation-induced DNA damage are eliminated by apoptosis that involves the p53 pathway and Fas/Fas-Ligand (Fas-L) interactions. To determine whether dysregulation of apoptosis plays a role in skin cancer development through disruption of Fas/Fas-L interactions, hairless SKH-hr1 mice were exposed to chronic UV irradiation from Kodacel-filtered FS40 lamps for 30 weeks. Their skin was analyzed for the presence of sunburn cells (apoptotic keratinocytes) and for Fas and Fas-L expression at various time points. A dramatic decrease in the numbers of morphologically identified sunburn cells and TUNEL-positive cells was detected as early as 1 week after chronic UV exposure began. After 4 weeks of chronic UV exposure, these cells were barely detectable. This defect in apoptosis was paralleled by an initial decrease in Fas-L expression during the first week of chronic UV irradiation and a complete loss of expression after 4 weeks. Fas expression, however, increased during the course of chronic UV exposure. p53 mutations were detected in the UV-irradiated epidermis as early as 1 week after irradiation began and continued to accumulate with further UV exposure. Mice exposed to chronic UV began to develop skin tumors after approximately 8 weeks, and all mice had multiple skin tumors by 24 weeks. Most of the tumors expressed Fas but not Fas-L. We conclude that chronic UV exposure may induce a loss of Fas-L expression and a gain in p53 mutations, leading to dysregulation of apoptosis, expansion of mutated keratinocytes, and initiation of skin cancer.

We examined the effects of ultraviolet (UV) radiation on the time course for induction of sunburn (apoptotic) cells and expression of proteins known to be associated with growth arrest and apoptosis in SKH-hr1 mouse skin. Mice were irradiated with a single dose (2.5 kJ/m(2)) of UV from Kodacel-filtered (290-400 nm) FS40 sunlamps and the skin tissues were analyzed at various times after irradiation for the presence of apoptotic cells and expression of p53, p21(Waf-1/Cip1), bcl-2, bax, and proliferating cell nuclear antigen. The results indicated that p53 expression was induced early in the epidermis, reaching maximum levels 12 hours after irradiaton, and p21(Waf-1/Cip1) expression in the epidermis peaked at 24 hours after irradiation. In contrast, UV radiation induced high levels of bax at 24 to 72 hours after irradiation with a concomitant decrease in bcl-2 expression. Coinciding with these changes, apoptotic cells began to appear 6 hours after irradiation and reached a maximum at 24 hours after irradiation. Interestingly, proliferating cell nuclear antigen expression, which was initially confined to the basal layer, became dispersed throughout the basal and suprabasal layers of the skin at 48 hours and paralleled marked hyperplasia. These results suggest that UV irradiation of mouse skin induces apoptosis mediated by the p53/p21/bax/bcl-2 pathway and that the dead cells are replaced by hyperproliferative cells, leading to epidermal hyperplasia. This implies that UV-induced apoptosis and hyperplasia are closely linked and tightly regulated and that dysregulation of these two events may lead to skin cancer development.

PURPOSE: The European Association of Hematopathologists and the Society for Hematopathology have developed a new World Health Organization (WHO) classification of hematologic malignancies, including lymphoid, myeloid, histiocytic, and mast cell neoplasms. DESIGN: Ten committees of pathologists developed lists and definitions of disease entities. A clinical advisory committee (CAC) of international hematologists and oncologists was formed to ensure that the classification would be useful to clinicians. The CAC met in November 1997 to discuss clinical issues related to the classification. RESULTS: The WHO uses the Revised European-American Lymphoma (REAL) classification, published in 1994 by the International Lymphoma Study Group, to categorize lymphoid neoplasms. The REAL classification is based on the principle that a classification is a list of “real” disease entities, which are defined by a combination of morphology, immunophenotype, genetic features, and clinical features. The relative importance of each of these features varies among diseases, and there is no one gold standard. The WHO classification applies the principles of the REAL classification to myeloid and histiocytic neoplasms. The classification of myeloid neoplasms recognizes distinct entities defined by a combination of morphology and cytogenetic abnormalities. At the CAC meeting, which was organized around a series of clinical questions, participants reached a consensus on most of the questions posed. They concluded that clinical groupings of lymphoid neoplasms were neither necessary nor desirable. Patient treatment is determined by the specific type of lymphoma, with the addition of grade within the tumor type, if applicable, and clinical prognostic factors, such as the International Prognostic Index. CONCLUSION: The WHO classification has produced a new and exciting degree of cooperation and communication between oncologists and pathologists from around the world, which should facilitate progress in the understanding and treatment of hematologic malignancies.

Although follicular lymphoma (FL) is very common in the Western world, very little information is available regarding the frequency and significance of monocytoid B cells (MBC) in FL. We recently completed a clinicopathologic study of 1,378 cases of non-Hodgkin's lymphoma. 1 In this study, a research data sheet was designed to conduct research on several types of lymphomas, one part of which was evaluating the presence of intrafollicular clear cells and extrafollicular MBC in 326 cases diagnosed as FL by one of the pathologists (B.N.N.). For each case diagnosed as FL, the presence of intrafollicular clear cells or extrafollicular MBC was scored as pure FL (no intrafollicular clear cells or extrafollicular MBC), FL with intrafollicular clear cells, FL with less than 5% MBC, and FL with greater than 5% MBC. Of 326 cases classified as FL, 252 (77%) had no intrafollicular clear cells or extrafollicular MBC and therefore were called pure FL. In 36 cases (11%), intrafollicular clear cells were seen, but no extrafollicular MBC. There were no clinical differences between such cases and the 252 cases of pure FL. In eight cases of FL (2%), MBC clusters were rare ( 5%) proliferation of extrafollicular MBC; these 30 cases had a significantly shorter failure-free survival ( P = .001) and overall survival ( P = .04) than the 252 cases of pure FL. The shorter survival of these 30 cases appeared to be independent of the international prognostic index (IPI), stage, and treatment. The FFS of this group remained shorter than that of cases with pure FL when the analysis was restricted to patients treated with Adriamycin-containing regimens and either a favorable (0 to 3) IPI score ( P = .001) or advanced stage (IIIIV) disease ( P = .015). In conclusion, FL with a prominent (>5%) MBC component constitutes a substantial proportion (9%) of FL and has distinctive morphology, and these patients have a significantly shorter survival than those with pure FL.

Proteomic studies to date have had limited use as an investigative tool in the skin's response to UV radiation. These studies used cell lines and reconstructed skin and have shown evidence of cell injury with oxidative damage and stress induced heat shock proteins. Others changes included altered cytokeratin and cytoskeletal proteins with enhanced expression of TRIM29 as the keratinocytes regenerate. The associated DNA repair requires polη, Rad18/Rad16 and Rev1. In the whole animal these events would be associated with inflammation, remodelling of the epidermis and modulation of the immune response. Longer term changes include ageing and skin cancers such as melanoma, squamous cell carcinoma and basal cell carcinoma. In the future proteomics will be used to explore these important aspects of photobiology. Better characterisation of the proteins involved should lead to a greater understanding of the skin's response to UV radiation.

The distribution of subtypes of non-Hodgkin lymphoma (NHL) in Latin America is not well known. This Chilean study included 207 consecutive cases of NHL diagnosed at five cancer centers in the capital, Santiago, and one center in Vina del Mar. All cases were reviewed and classified independently by five expert hematopathologists according to the 2001 World Health Organization classification of NHL. A consensus diagnosis of NHL was reached in 195 of the 207 cases (94%). B-cell lymphomas constituted 88% of NHL, and diffuse large B-cell lymphoma (DLBCL, 38.5%) and follicular lymphoma (25.1%) were the most common subtypes. There was a high frequency of marginal zone B-cell lymphoma (10.3%), as well as of extranodal natural killer (NK)/T-cell lymphoma, nasal type (2.6%) and adult T-cell leukemia/lymphoma (0.5%). Extranodal presentation was seen in 74 of the 195 cases (38%) and the most common extranodal presentation was in the stomach (37.6%). The most common gastric lymphoma was DLBCL (54.5%) followed by mucosa-associated lymphoid tissue (MALT) lymphoma (41%). Overall, the frequency of NHL subtypes in Chile is between that reported in Western and Eastern countries, which is probably a reflection of the admixture of ethnicities as well as the environment and socioeconomic status of its population.

Background and Objective. Using Collagen IV staining, we have previously reported that the reticular basement membrane (Rbm) is hypervascular and the lamina propria (LP) is hypovascular in COPD airways. This study compared Collagen IV staining with vessels marked with anti-Factor VIII and examined vessel permeability in bronchial biopsies from COPD and normal subjects using albumin staining. Results. Anti-Collagen IV antibody detected more vessels in the Rbm (P=0.002) and larger vessels in both Rbm (P<0.001) and LP (P=0.003) compared to Factor VIII. COPD airways had more vessels (with greater permeability) in the Rbm (P=0.01) and fewer vessels (with normal permeability) in the LP compared to controls with both Collagen IV and Factor VIII antibodies (P=0.04 and P=0.01). Conclusion. Rbm vessels were increased in number and were hyperpermeable in COPD airways. Anti-Collagen IV and anti-Factor VIII antibodies did not uniformly detect the same vessel populations; the first is likely to reflect larger and older vessels with the latter reflecting smaller, younger vessels.

Neonates have a developing immune response, with a predisposition towards induction of tolerance. As the immune system develops, immunity rather than tolerance is induced, with this development of immunity occurring in response to external factors such as the environment. As ultraviolet radiation (UVR) suppresses immunity, it is likely that the effect of UVR on the neonatal immune system would be augmentation of the suppressive response. In support, childhood exposure to UVR has been linked with an increased incidence of melanoma; consistent with an increase in suppression. To address this, phenotypic and functional immune system studies were undertaken at 8 weeks after one single exposure of solar-simulated UVR to mice, when mice had reached adulthood. Subtle changes were observed in cell populations resident in the skin-draining lymph nodes (LNs) and there also appeared to be a subtle, but not statistically significant, increase in the production of interleukin-10 and interferon-γ. Importantly, these changes also corresponded with significant suppression of the contact hypersensitivity response in irradiated mice compared with their control counterparts. This suppression was apparent when antigen sensitisation occurred during the neonatal or adult period, and thus did not appear to be analogous to UVR-induced suppression in adults. Although the percentage of T regulatory cells was increased in the skin-draining LNs, they were induced in a different manner to those induced following adult UVR exposure, with no increase in function on a per-cell basis. It therefore appears that one single neonatal exposure to UVR alters development of the immune system, leading to long-term implications for induction of immunity.

Background Little is known about airway remodelling in bronchial biopsies (BB) in smokers and chronic obstructive pulmonary disease (COPD). We conducted an initial pilot study comparing BB from COPD patients with nonsmoking controls. This pilot study suggested the presence of reticular basement membrane (Rbm) fragmentation and altered vessel distribution in COPD. Methods To determine whether Rbm fragmentation and altered vessel distribution in BB were specific for COPD we designed a cross-sectional study and stained BB from 19 current smokers and 14 ex-smokers with mild to moderate COPD and compared these to 15 current smokers with normal lung function and 17 healthy and nonsmoking subjects. Results Thickness of the Rbm was not significantly different between groups; although in COPD this parameter was quite variable. The Rbm showed fragmentation and splitting in both current smoking groups and ex-smoker COPD compared with healthy nonsmokers (p < 0.02); smoking and COPD seemed to have additive effects. Rbm fragmentation correlated with smoking history in COPD but not with age. There were more vessels in the Rbm and fewer vessels in the lamina propria in current smokers compared to healthy nonsmokers (p < 0.05). The number of vessels staining for vascular endothelial growth factor (VEGF) in the Rbm was higher in both current smoker groups and ex-smoker COPD compared to healthy nonsmokers (p < 0.004). In current smoker COPD VEGF vessel staining correlated with FEV1% predicted (r = 0.61, p < 0.02). Conclusions Airway remodelling in smokers and mild to moderate COPD is associated with fragmentation of the Rbm and altered distribution of vessels in the airway wall. Rbm fragmentation was also present to as great an extent in ex-smokers with COPD. These characteristics may have potential physiological consequences.

Histologic, molecular, and epidemiologic data suggest that cutaneous melanomas arise through diverse causal pathways, one of which appears mediated by chronic sunlight exposure, and another associated with a nevus-prone phenotype. To further explore etiologic heterogeneity, we compared expression of key melanoma-related proteins according to histologic characteristics of the tumors and epidemiologic risk factors among a sample of 129 patients newly diagnosed with melanoma. Tumor tissue was stained with antibodies to phospho-mitogen-activated protein kinase (P-MAPK), Brn-2, retinoblastoma protein (pRb), p53, and p16. Using logistic regression analysis, we estimated the odds ratio (OR) and 95% confidence interval (95% CI) of protein expression associated with factors of interest. Except for pRb, candidate protein expression was detected in fewer than half the melanomas examined (P-MAPK, 39%; Brn-2, 30%; p53, 24%; p16, 41%). Strong pRb expression was associated with the presence of >20 solar keratoses (OR 6.5, 95% CI: 1.7-25.1) and melanomas with marked to moderate solar elastosis. p53 expression was positively associated with skin that readily burned (OR 3.8, 95% CI: 0.8-19.0) and was inversely associated with >60 nevi (OR 0.3, 95% CI: 0.04-1.5). Melanomas expressing P-MAPK were more likely to have contiguous neval remnants (OR 2.7, 95% CI: 1.1-6.5). P-MAPK and Brn-2 immunopositive melanomas were >/=4-fold more likely to be of the superficial spreading subtype. Brn-2 and p16 immunopositive melanomas had a greater Breslow thickness than melanomas that did not express these proteins. Brn-2, pRb, and p16 proteins were consistently coexpressed. These findings support the hypothesis that molecular profiles of melanoma reflect their histologic and epidemiologic characteristics, offering further evidence of more than one melanoma causal pathway. Exactly how the expression of each protein relates to the causal pathways needs to be further explored.

Mutations of the TP53 tumor suppressor gene have been associated with poor survival in some series of diffuse large B-cell lymphoma (DLBCL) but not in other studies. The purpose of this study was to identify the frequency of TP53 alterations (mutations or deletions), characterize the gene expression of mutant/deleted cases, and determine the effects of mutations on survival. In a series of DLBCL that had previous gene expression profiling, we identified 24 mutations in 113 cases (21%). There was no difference in the frequency of mutations in the molecular subgroups of DLBCL. Twelve (50%) of the 24 cases had mutations localized to the DNA-binding codons in the core domain of TP53. The presence of any TP53 mutation correlated with poor overall survival (OS; P = .044), but DNA-binding mutations were the most significant predictor of poor OS (P < .001). Multivariate analysis confirmed that the International Prognostic Index, tumor size, and TP53 DNA-binding mutations were independent predictors of OS. Gene expression analysis showed that TRAILreceptor-2 (DR5) was the most differentially underexpressed gene in the TP53 mutated cases. Investigation is warranted into targeted therapy toward TRAIL receptor-2, to potentially bypass the adverse effect of mutated TP53 in DLBCL.

This study was undertaken to further elucidate the biological mechanisms underlying the frequent event of transformation of follicular lymphoma (FL) to diffuse large B-cell lymphoma (t-FL). The gene expression profiles of 20 paired lymph node biopsies, derived from the same patient pre- and post-transformation, were analysed using the Lymphochip cDNA microarray. TP53 mutation analysis was performed and copy number alterations at the c-REL and CDNK2A examined. Immunohistochemistry was performed on an independent panel of paired transformation paraffin-embedded samples. Transformed follicular lymphoma was predominantly of the germinal centre B-like phenotype both at the mRNA and protein level. Despite this homogeneity, transformation proceeded by at least two pathways. One mechanism was characterised by high proliferation, as assessed by the co-ordinately expressed genes of the proliferation signature. This group was associated with the presence of recurrent oncogenic abnormalities. In the remaining cases, proliferation was not increased and transformation proceeded by alternative routes as yet undetermined. Genes involved in cellular proliferation prevailed amongst those that were significantly increased upon transformation and T cell and follicular dendritic-associated genes predominated amongst those that decreased. t-FL is a germinal centre B (GCB)-like malignancy that evolves by two pathways, one that is similar in proliferation rate to the antecedent FL and the other that has a higher proliferation rate and is characterised by the presence of recognised oncogenic abnormalities.

INTRODUCTION The distribution of non-Hodgkin lymphoma (NHL) subtypes varies around the world, but a large and systematic comparative study has not been done. This study is first to evaluate the relative frequencies of NHL subtypes in seven regions of the world. METHODS Five expert hematopathologists classified 4848 consecutive cases of NHL from 25 countries in seven regions, including North America, Central/South America, Western Europe, Southeastern Europe, Southern Africa, the Middle East/North Africa, and the Far East, using the WHO classification. Data from the developed world (North America and Western Europe) was compared to the developing world (all other regions combined). RESULTS Among the 4848 cases reviewed, 4539 (93.6%) were confirmed to be NHL, whereas the other 309 (6.4%) had diagnoses other than NHL and were excluded from further analysis. A significantly higher male to female ratio was found in the developing regions (1.4:1) compared to the developed world (1:1; p CONCLUSION Our study is the first to systematically compare the relative frequencies of NHL subtypes in different regions around the world, and provides new evidence of significant geographic differences. Our findings suggest that differences in etiologic and/or host risk factors are likely responsible, and more detailed epidemiologic studies are needed to better understand these differences. Disclosures Armitage: Celgene: Consultancy; Ziopharm: Consultancy; Tesaro Bio, Inc: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Conatus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Spectrum: Consultancy.

Multiple endocrine neoplasia type 1 (MEN1) is an inherited cancer predisposition syndrome typified by development of tumors in parathyroid, pituitary and endocrine pancreas, as well as less common sites including both endocrine and nonendocrine organs. Deletion or mutation of the tumor suppressor gene MEN1 on chromosome 11 has been identified in many cases of MEN1 as well as in sporadic tumors. The molecular biology of menin, the protein encoded by MEN1, remains poorly understood. Here we describe a mouse model of MEN1 in which tumors were seen in pancreatic islets, pituitary, thyroid and parathyroid, adrenal glands, testes and ovaries. The observed tumor spectrum therefore includes types commonly seen in MEN1 patients and additional types. Pancreatic pathology was most common, evident in over 80% of animals, while other tumor types developed with lower frequency and generally later onset. Tumors of multiple endocrine organs were observed frequently, but progression to carcinoma and metastasis were not evident. Tumors in all sites showed loss of heterozygosity at the Men1 locus, though the frequency in testicular tumors was only 36%, indicating that a different molecular mechanism of tumorigenesis occurs in those Leydig tumors that do not show loss of the normal Men1 allele. Menin expression was below the level of detection in ovary, thyroid and testis, but loss of nuclear menin immunoreactivity was observed uniformly in all pancreatic islet adenomas and in some hyperplastic islet cells, suggesting that complete loss of Men1 is a critical point in islet tumor progression in this model.

Loss of major histocompatibility class II (MHC II) expression in diffuse large B-cell lymphoma (DLBCL) correlates with worse outcome, possibly from decreased immunosurveillance. Primary mediastinal B-cell lymphoma (PMBCL) is a subtype of DLBCL which reportedly has frequent loss of MHC II proteins; however, PM-BCL has better survival than DLBCL. To investigate this paradox, we used geneexpression profiling (GEP) data and immunohistochemistry to study expression of MHC II and its regulatory genes and to determine their relationship to PMBCL survival. We found that GEP levels correlated between MHC II genes and the transcriptional regulator MHC2TA but not other adjacent genes, implying that transcriptional regulation of MHC II in PMBCL was intact and that MHC II gene deletion was unlikely. MHC II average expression was lower than in certain subtypes of DLBCL; however, only 12% had complete loss of MHC II expression. Poor patient survival in PMBCL correlated with incremental decreases in MHC II expression. Although overall survival was better, survival of the lowest 10% of MHC II expressers was similarly poor in DLBCL and PMBCL. MHC II expression may define a therapeutic target in both these diseases. (Blood. 2006;108:311-318)

Background The role of BCL2 as a predictor of survival in diffuse large B-cell lymphoma (DLBCL) is controversial. DLBCL is heterogeneous, and the expression of BCL2 is variable within the two major subgroups of DLBCL, germinal center B-cell–like (GCB) and activated B-cell–like (ABC) DLBCL, as well as primary mediastinal DLBCL. Patients and Methods In this study, we investigated the correlation of BCL2 expression with survival in the two major subgroups of DLBCL, as well as the mechanisms of BCL2 expression. Results There was no significant correlation between BCL2 protein expression and overall survival within the GCB subgroup, but BCL2 expression had a significant adverse effect on overall survival within the ABC subgroup (P = .008). This correlation was also observed at the mRNA level (P < .04). The difference remained significant when the analyses were performed at different cutoff values. The t(14;18) was frequently observed in the GCB subgroup and was highly associated with BCL2 expression. Patients with ABC DLBCL did not exhibit t(14;18) but had a markedly higher frequency of chromosome 18q21 amplification, on which BCL2 resides. Thus, alternative mechanisms such as 18q21 amplification or activation of the nuclear factor-kappa B pathway, as reported previously, seem to be mainly responsible for the upregulation of BCL2 expression in the ABC subgroup. Conclusion Treating all DLBCL as a single entity ignores the mechanistic differences in BCL2 upregulation and obscures the prognostic significance of BCL2 expression. Hence, the significance of BCL2 and other biomarkers should be assessed in the context of DLBCL subgroups in future studies.

Cyclin D1 overexpression is believed to be essential in the pathogenesis of mantle cell lymphoma (MCL). Hence, the existence of cyclin D1-negative MCL has been controversial and difficult to substantiate. Our previous gene expression profiling study identified several cases that lacked cyclin D1 expression, but had a gene expression signature typical of MCL. Herein, we report the clinical, pathologic, and genetic features of 6 cases of cyclin D1-negative MCL. All 6 cases exhibited the characteristic morphologic features and the unique gene expression signature of MCL but lacked the t(11;14)(q13; q32) by fluorescence in situ hybridization (FISH) analysis. The tumor cells also failed to express cyclin D1 protein, but instead expressed either cyclin D2 (2 cases) or cyclin D3 (4 cases). There was good correlation between cyclin D protein expression and the corresponding mRNA expression levels by gene expression analysis. Using interphase FISH, we did not detect chromosomal translocations or amplifications involving CCND2 and CCND3 loci in these cases. Patients with cyclin D1-negative MCL were similar clinically to those with cyclin D1-positive MCL. In conclusion, cases of cyclin D1-negative MCL do exist and are part of the spectrum of MCL. Up-regulation of cyclin D2 or D3 may substitute for cyclin D1 in the pathogenesis of MCL.

Malignant melanoma (MM) in humans develops within a complex aetiologic framework of genetic, host, and environmental factors (Goldstein & Tucker, 2001). The strongest environmental risk factor is sun exposure (Sulaimon et al., 2003). In the mouse, wild type animals are resistant to MM development even when exposed to repeated treatments with ultraviolet radiation (UVR) (Gallagher et al., 1984). However chronic UVR treatment regimens have increased MM penetrance by up to 26% in mice carrying various transgenes capable of inducing spontaneous MM development, or melanocytic hyperplasia, e.g. Tyr-SV40Tag (Kelsall & Mintz, 1998; Klein-Szanto et al., 1994), TPras (Broome Powell et al., 1999) and Mt-Hgf/Sf (Noonan et al., 2000) mice. More recently, Noonan et al. (2001) showed that a single neonatal dose of 9 kJ/m2 was far more effective than chronic treatments at inducing MM in the Mt-Hgf/Sf transgenics. Kannan et al. (2003) used the neonatal UVR regimen on mice with melanocyte-specific activation of Hras on a background of either Ink4a or Arf nullizygosity. At 22 weeks, Ink4a -/-:Tyr-Hras and Arf -/-:Tyr-Hras animals developed spontaneous MM, with an incidence of 35% and 53% respectively (Chin et al., 1997). Importantly, neonatal UVR exposure resulted in a marked increase in MM development only in the Arf -/-:Tyr-Hras animals (penetrance rose to 88%) (Kannan et al., 2003), implying that a defect in the p53 pathway may be necessary for UVR-induced MM. Arf -/-:Tyr-Hras tumours were characterized by Cdk6 amplification and Ink4a mutation, genetic lesions that were never observed in non–UVR induced MM. Notably, these secondary mutations indicate that these UVR-induced MM may only arise on an activated Hras background when both the p53 and pRb pathways are compromised.

background Patients with follicular lymphoma may survive for periods of less than 1 year to more than 20 years after diagnosis. We used gene-expression profiles of tumor-biopsy specimens obtained at diagnosis to develop a molecular predictor of the length of survival. methods Gene-expression profiling was performed on 191 biopsy specimens obtained from patients with untreated follicular lymphoma. Supervised methods were used to discover expression patterns associated with the length of survival in a training set of 95 specimens. A molecular predictor of survival was constructed from these genes and validated in an independent test set of 96 specimens. results Individual genes that predicted the length of survival were grouped into gene-expression signatures on the basis of their expression in the training set, and two such signatures were used to construct a survival predictor. The two signatures allowed patients with specimens in the test set to be divided into four quartiles with widely disparate median lengths of survival (13.6, 11.1, 10.8, and 3.9 years), independently of clinical prognostic variables. Flow cytometry showed that these signatures reflected gene expression by nonmalignant tumor-infiltrating immune cells. conclusions The length of survival among patients with follicular lymphoma correlates with the molecular features of nonmalignant immune cells present in the tumor at diagnosis.

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed prognostically important subgroups: germinal center B-cell-like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal large B-cell lymphoma. The t(14;18)(q32;q21) has been reported previously to define a unique subset within the GCB-DLBCL. We evaluated for the translocation in 141 cases of DLBCL that were successfully gene expression profiled. Using a dual-probe fluorescence in situ hybridization assay, we detected the t(14;18) in 17% of DLBCLs and in 34% of the GCB subgroup which contained the vast majority of positive cases. In addition, 12 t(14;18)-positive cases detected by polymerase chain reaction assays on additional samples were added to the fluorescence in situ hybridization-positive cases for subsequent analysis. Immunohistochemical data indicated that BCL2, BCL6, and CD10 protein were preferentially expressed in the t(14;18)-positive cases as compared to t(14;18)-negative cases. Within the GCB subgroup, the expression of BCL2 and CD10, but not BCL6, differed significantly between cases with or without the t(14;18): 88% versus 24% for BCL2 and 72% versus 32% for CD10, respectively. In the GCB-DLBCL subgroup, a heterogeneous group of genes is overexpressed in the t(14;18)-positive subset, among which BCL2 is a significant discriminator. Interestingly, the t(14;18)-negative subset is dominated by overexpression of cell cycle-associated genes, indicating that these tumors are significantly more proliferative, suggesting distinctive pathogenetic mechanisms. However, despite this higher proliferative activity, there was no significant difference in overall or failure-free survival between the t(14;18)-positive and -negative subsets within the GCB subgroup.

Diffuse large B-cell lymphoma (DLBCL) can be divided into prognostically important subgroups with germinal center B-cell-like (GCB), activated B-cell-like (ABC), and type 3 gene expression profiles using a cDNA microarray. Tissue microarray (TMA) blocks were created from 152 cases of DLBCL, 142 of which had been successfully evaluated by cDNA microarray (75 GCB, 41 ABC, and 26 type 3). Sections were stained with antibodies to CD10, bcl-6, MUM1, FOXP1, cyclin D2, and bcl-2. Expression of bcl-6 (P

The survival of patients with diffuse large-B-cell lymphoma after chemotherapy is influenced by molecular features of the tumors. We used the gene-expression profiles of these lymphomas to develop a molecular predictor of survival.Biopsy samples of diffuse large-B-cell lymphoma from 240 patients were examined for gene expression with the use of DNA microarrays and analyzed for genomic abnormalities. Subgroups with distinctive gene-expression profiles were defined on the basis of hierarchical clustering. A molecular predictor of risk was constructed with the use of genes with expression patterns that were associated with survival in a preliminary group of 160 patients and was then tested in a validation group of 80 patients. The accuracy of this predictor was compared with that of the international prognostic index.Three gene-expression subgroups--germinal-center B-cell-like, activated B-cell-like, and type 3 diffuse large-B-cell lymphoma--were identified. Two common oncogenic events in diffuse large-B-cell lymphoma, bcl-2 translocation and c-rel amplification, were detected only in the germinal-center B-cell-like subgroup. Patients in this subgroup had the highest five-year survival rate. To identify other molecular determinants of outcome, we searched for individual genes with expression patterns that correlated with survival in the preliminary group of patients. Most of these genes fell within four gene-expression signatures characteristic of germinal-center B cells, proliferating cells, reactive stromal and immune cells in the lymph node, or major-histocompatibility-complex class II complex. We used 17 genes to construct a predictor of overall survival after chemotherapy. This gene-based predictor and the international prognostic index were independent prognostic indicators.DNA microarrays can be used to formulate a molecular predictor of survival after chemotherapy for diffuse large-B-cell lymphoma.

Periaxin is a newly described protein that is expressed in myelinating Schwann cells. In developing and regenerating nerves, periaxin is predominantly localised to the adaxonal surface of Schwann cells as they begin to form compact myelin. In adult nerves, peraxin is expressed by myelinating Schwann cells and localised to the abax-onal surface. Its localisation changes dynamically during ensheath-ment and myelination. Periaxin is expressed in devil facial tumour disease (DFTD), a transmissible cancer that is threatening the survival of the Tasmanian devil ( Sarcophilus harrisii) . DFTD cells express proteins characteristic of myelinating Schwann cells, including periaxin. A useful diagnostic marker for DFTD is expression of periaxin. We investigated the expression of periaxin in a variety of human peripheral nerve sheath tumours and related lesions such as schwannomas, neurofibromas, traumatic neuromas, solitary circumscribed neuromas, malignant peripheral nerve sheath tumours and granular cell tumours. Several different human tissue controls including bowel, gallbladder, smooth muscle neoplasms, naevi and melanoma were also used. The expression of periaxin was compared with a range of proteins associated with nerve tissue including S100, neurofilament, EMA and CD34. We conclude that periaxin, correlates most closely with neurofilament expression, in schwannomas, neurofibromas and normal nerve tissue controls. Periaxin does not appear to have an additional role in the diagnosis of human peripheral nerve sheath tumours and related lesions.

Epidemiological studies have suggested an association between exposure to solar UV radiation and the incidence of lymphoid malignancies, which has increased substantially worldwide during the last two decades. Findings from animal studies have raised the question of whether UV radiation might influence the development of lymphoid malignancies by means of its immunosuppressive effect. In this study, we examined the effect of UV irradiation on the development of lymphoid malignancies in mice with no or only one functional copy of p53 . Mice that lack both copies of p53 spontaneously develop high frequency of lymphoid malignancies in the thymus and spleen. p53 heterozygous mice with only one copy of the wild-type allele also develop lymphoid malignancies, but with a much lower frequency and a long latent period. In our study using mice of the C57BL/6 background, only one of the unirradiated mice lacking one copy of p53 ( p53 +/− ) spontaneously developed a lymphoid tumor (6%), whereas 88% of UV-irradiated p53 +/− mice developed lymphoid tumors in the spleen or liver. None of the control or UV-irradiated p53 wild-type mice developed lymphoid tumors during the 60-week observation period. Both UV-irradiated and unirradiated mice lacking both copies of p53 ( p53 −/− ) rapidly developed thymic lymphomas and/or lymphoid tumors in spleen or liver. All of the lymphoid tumors tested were of T cell type. The immune responses of the mice to contact sensitization were identical and were suppressed to the same extent by UV irradiation regardless of the genotype. These results indicate that differences in immune reactivity do not account for the different effects of UV radiation on lymphoid malignancies and, in addition, that p53 is not required for generation of T cell-mediated immunity. Interestingly, whereas p53 mutations or loss of heterozygosity did not account for the accelerated development of lymphoid tumors in UV-irradiated p53 +/− mice, deletions in the p16 INK4a gene were quite common. These data provide the experimental evidence that UV irradiation induces lymphoid neoplasms in genetically susceptible mice and support the hypothesis that extensive sunlight exposure contributes to the induction of lymphoma in humans.

UVB irradiation is a major cause of human skin cancer. In addition to inducing neoplastic changes, UVB irradiation also causes immune suppression which may impair local defence reactions allowing abnormal cells to proliferate and develop into skin tumours.1 The immuno-suppressive events induced by UVB irradiation are mediated by a number of pathways involving altered DNA,2 cis-urocanic acid (cis-UCA),3 IL-10,4 and mast cells.5 UVB-damaged DNA can result in mutations including those of p53, allowing the proliferation of aberrant cells and, ultimately, local tumour invasion. In p53 gene knockout mice, development of skin tumours increases more rapidly after exposure to UVB irradiation.6 p53 as a target for UV-induced mutations in developing murine and human skin cancer involves C→T and CC→TT transitions at dipyrimidine sites.7 This paper summarises the adaptive responses in mouse skin following acute and chronic UV irradiation.

The BOB.1/OBF.1/OCAB.1 protein is a lymphocyte-specific transcriptional coactivator. It interacts with the Oct1 and Oct2 transcription factors and contributes to the transcriptional activity of octamer motifs. The analysis of established B cell lines had suggested that BOB.1/OBF.1 is constitutively expressed at all stages of B cell development. Here we show that expression of BOB. 1/OBF.1 is regulated within the B cell lineage. Specifically, germinal center B cells show highly increased BOB.1/OBF.1 levels. We can induce the up-regulation by stimulating primary splenic B cells, eg, by triggering CD40 signaling in the presence of interleukin-4. Expression of BOB.1/OBF.1 is detectable but reduced in spleens from mice unable to undergo the germinal center reaction due to mutations in the TNF receptor p55 or lymphotoxin beta (LTbeta) receptor genes. Furthermore, we demonstrate that BOB.1/OBF.1 expression is highly regulated in human B cell lymphomas. Whereas lymphomas representing pre- and postfollicular B cell developmental stages are negative for BOB.1/OBF.1, high-level expression of BOB.1/OBF.1 is characteristic of germinal center-derived tumors. In these tumors BOB.1/OBF.1 is typically coexpressed with high levels of Bcl6. These results imply that overexpression of BOB.1/OBF.1, like overexpression of Bcl6, might play a role in the pathogenesis of germinal center-derived B cell lymphomas. Furthermore, overexpression of BOB.1/OBF.1 represents a characteristic feature of these tumors that is useful in their identification.

The discovery of P-glycoprotein has revealed a fundamental mechanism by which cancer cells evade chemotherapy and this principle has proven relevant to general cellular defence mechanisms in normal physiology. To date this knowledge has promised to improve current cancer chemotherapy through the manipulation of drug combinations according to the P-glycoprotein status of the tumor. Furthermore, the discovery of inhibitors of the protein may provide new therapeutic tools in the treatment of multidrug resistant neoplasia, provided the benefits are deemed greater than the potential detrimental side effects. When looking towards future therapies, however, we must also consider additional mechanisms which undoubtedly contribute to clinical drug resistance. Complete elucidation of this complex cellular defence network will hopefully translate into therapeutic opportunities to circumvent all mechanisms of multidrug resistance, thus positively impacting on patient survival.

The density of zinc-iodide-osmium (ZIO) positive pulmonary Langerhans dendritic cells (LC) was increased about 20-fold in mice after passive exposure to tobacco smoke. This was associated with pulmonary changes consistent with the cigarette smoking-related clinical syndrome in humans, pulmonary Langerhans cell granulomatosis. The major feature was an interstitial peribronchial granuloma. The cellular infiltrate of the granuloma (lymphocytes, plasma cells, eosinophils, clusters of large histiocyte-like cells and macrophages) extended into the adjacent alveolar septum forming a star-shaped lesion. The histiocyte-like cells were large with pale acidophilic cytoplasm and many ill-defined short dendrites extending from the cell membrane. Bronchial epithelial metaplasia also developed. The interstitial changes were followed by the development of proliferative alveolar and bronchial lesions in 2 mice. The zinc-iodide-osmium positive cells were consistent with la positive pulmonary dendritic cells and their ultrastructure was similar to that of pulmonary Langerhans cells. After ceasing exposure to tobacco smoke the density of pulmonary Langerhans cells returned to that of the control level; interstitial granulomatous lesions disappeared, but the bronchial epithelial metaplasia did not reverse. Tobacco smoke exposure of mice produces interstitial granulomatous inflammation similar to Langerhans cell granulomatosis in humans. The elevated level of pulmonary Langerhans cells implicate these cells in the pathogenesis of these lesions.

In this retrospective study a series of 54 patients (seen from 1982 to 1989) with sporadic primary cerebral malignant lymphomas (PCML), which were uniformly classified with the support of immunocytochemical data, is presented. The analysis shows that on CT PCML are shown as cirumscribed, homogeneous, contrast-enhanced multifocal (70%) or solitary (30%) mass lesions within the subcortical white matter; they were found mainly close to the ventricular system or the subarachnoid space. To prove the histological diagnosis and for the purposes of differential diagnosis, low-risk CT-stereotactic biopsy is necessary and is the method of choice. Immunomorphological techniques are valuable adjuncts to confirm the histological diagnosis of PCML. In the series presented these tumours have been predominantly classified as high-grade blastic B-cell lymphomas. For this reason, this type should be regarded as the prevalent variant of malignant brain lymphomas. The evaluation of possible prognostic factors suggests that age at admission and morphological features of regression are relevant determinants of survival time. A correlation between neuroradiological evidence of a decrease in tumour size, morphological signs of regression and glucocorticoid administration has been found. Thus, patients suspected of having PCML require rapid diagnosis prior to corticosteroid administration. PCML have been shown to be radioresponsive, but not curable. Because of the lack of uniformity in management of this rare brain neoplasm, the different treatment protocols are not comparable, and hence the optimum therapy has not been satisfactorily determined. Therefore, a rational diagnostic strategy is proposed as a basis for prospective randomized long-term follow-up studies in order to evaluate different treatment modalities and to obtain more insight into the biological behaviour of primary cerebral malignant lymphomas.