Gene expression in colorectal neoplasia: modifications induced by tissue ischaemic time and tissue handling protocol.

AIMS: The heterogeneity within individual distinct cancer types in terms of behaviour, response to therapy and prognosis is well recognized. A major goal of translational research projects has therefore been to define clinically significant subgroups of individual tumour types by analysis of mRNA as well as protein expression. An essential premise of such investigations is that expression of these key molecules is a true reflection of conditions present within the neoplastic cells in vivo. The aim was to investigate the effect of methods of tissue handling and storage on expression of mRNA. METHODS AND RESULTS: mRNA expression in 60 biopsy samples obtained from 10 patients with colorectal tumours was examined. The mRNA expression profile and the level of expression of specific mRNA species were significantly affected by the procedures used for collection and storage of tissue samples. Significant variation in the level of expression (both increased and decreased) of transcripts was detectable after 15 min, and by 120 min there was a fourfold increase in the number of genes with a more than twofold change in the level of expression. CONCLUSIONS: Reliable interpretation of results of gene expression at the mRNA level requires standardized protocols for tissue procurement.

Seliciclib (CYC202, R-roscovitine) enhances the antitumor effect of doxorubicin in vivo in a breast cancer xenograft model.

We sought to determine whether seliciclib (CYC202, R-roscovitine) could increase the antitumor effects of doxorubicin, with no increase in toxicity, in an MCF7 breast cancer xenograft model. The efficacy of seliciclib combined with doxorubicin was compared with single agent doxorubicin or seliciclib administered to MCF7 cells and to nude mice bearing established MCF7 xenografts. Post-treatment cells and tumors were examined by cell cycle analysis, immunohistochemistry and real-time PCR. Seliciclib significantly enhanced the antitumor effect of doxorubicin without additional murine toxicity. MIB1 (ki67) immunohistochemistry demonstrated reduced proliferation with treatment. The levels of p21 and p27 increased after treatment with doxorubicin or seliciclib alone or in combination, compared to untreated controls. However, no changes in p53 protein (DO1, CM1), survivin or p53 phosphorylation (SER15) were observed in treated tumors compared with controls. In conclusion, the CDK inhibitor seliciclib (R-roscovitine) enhances the antitumor effect of doxorubicin in MCF7 tumors without increased toxicity with a mechanism that involves cell cycle arrest rather than apoptosis.

Kikuchi's disease displaying a t(2:16) chromosomal translocation.

Kikuchi's disease is a rare self-limiting lymphoproliferative condition of unknown aetiology, characterised by acute or subacute necrotising lymphadenitis. It is a benign condition that can mimic malignant lymphoma. In this report, a case of Kikuchi's disease associated with a chromosomal abnormality is described. This is the first report in the literature of such a case and it highlights an important learning point; benign lymphoproliferative conditions can be associated with chromosomal abnormalities that are more typically associated with malignant lymphoproliferative conditions such as malignant lymphoma. The report illustrates the necessity for interpreting cytogenetic data in the relevant clinical and histopathological context in a multidisciplinary setting to avoid misdiagnosis and inappropriate treatment.

A simple and rapid approach to the problem of tissue contamination and patient identity in histopathologic specimens.

Individual pathologists deal with thousands of diagnostic biopsy and excision specimens annually. At each stage, procedures are in place to limit the possibility of human error, which could result in specimen transposition or contamination. One specimen contaminating another is usually easily identified and rarely causes diagnostic difficulty; however, when it does, the consequences can be very serious. We discuss 5 cases in which concerns over specimen identity and tissue contamination arose and the methodology by which we resolved those concerns. Polymerase chain reaction analysis of each case was carried out using a panel of 12 polymorphic microsatellite markers, specific for chromosomes 13, 18, and 21. These markers are routinely used in the molecular genetics diagnostic laboratory for rapid trisomy screening. In each case, the question of error was satisfactorily resolved. Using this approach, we prevented the real possibility of patients undergoing second invasive procedures. We suggest that this or a similar methodology become a routine part of pathology practice.

Lesions resembling Langerhans cell histiocytosis in association with other lymphoproliferative disorders: a reactive or neoplastic phenomenon?

Langerhans cell histiocytosis (LCH) has been described in association with a variety of neoplasms preceding, after, or synchronous with the other tumor. In some cases, a neoplasm may arise as a complication of therapy for LCH, and in others, the association may be coincidental. Synchronous occurrence has been reported most commonly in association with malignant lymphoma in which discrete proliferations of Langerhans cells (LCs) histologically indistinguishable from LCH are seen. In most cases, these LCs are closely related to or intermingling with the primary pathology. The nature of LCs in this context remains elusive with debate as to whether they represent a true clonal neoplasm or an exaggerated reactive phenomenon. The lack of evidence for LCH progression or disease elsewhere strongly supports the latter. We have encountered 5 examples of LCH-like proliferations occurring in the context of other lymphoproliferative disorders. These include 2 cases of mycosis fungoides and 1 of cutaneous B-cell pseudolymphoma, associations that to our knowledge have not been described before. Two patients were female, and the clonality of the LC proliferation was assessed using laser capture microdissection and the human androgen receptor. The results showed that the LCs forming discrete nodules in a case of cutaneous B-cell pseudolymphoma and a case of Hodgkin's lymphoma were polyclonal. This suggests that, at least in a proportion of cases, the aggregates of LCs occasionally identified within other lymphoproliferative lesions represent a reactive proliferation rather than a potentially aggressive second neoplasm.