HER2 aberrations and heterogeneity in cancers of the digestive system : Implications for pathologists and gastroenterologists

Management of cancers of the digestive system has progressed rapidly into the molecular era. Despite the significant recent achievements in the diagnosis and treatment of these patients, the number of deaths for these tumors has currently plateaued. Many investigations have assessed the role of HER2 in tumors of the digestive system in both prognostic and therapeutic settings, with heterogeneous results. Novel testing and treatment guidelines are emerging, in particular in gastric and colorectal cancers. However, further advances are needed. In this review we provide a comprehensive overview of the current state-of-knowledge of HER2 alterations in the most common tumors of the digestive system and discuss the operational implications of HER2 testing

Degradation of insulin-like growth factor-I receptor occurs via ubiquitin-proteasome pathway in human lung cancer cells

Insulin-like growth factor-I receptor (IGF-IR) is often overexpressed in malignant tumors, and is involved in the establishment and maintenance of malignant phenotypes. Tyrosine kinase receptor endocytosis is commonly triggered by ligand binding and occurs via clathrin-coatedvescicles that transfer the receptor to the lysosome system for degradation. Our study aims at the evaluation of the mechanisms involved in IGF-IR downregulation in neoplastic (Npl) and non-neoplastic (non-Npl) cells. Exposure to insulin-like growth factor-I (IGF-I) of human lung adenocarcinoma cell lines (A549 and H1299) triggers IGF-IR ubiquitination and internalization processes that require energy and are preceded by the phosphorylation of receptor tyrosines. Differently from other plasma membrane substrates of the ubiquitin system, IGF-IR is degraded mostly by the proteasome in these tumor cell lines. The degradation is inhibited by lactacystin and unaffected by lysosomal inhibitors such as bafilomycin A1 and NH(4)Cl. IGF-IR is processed in a similar manner also in fresh specimens of human lung tumors, while it requires active lysosomal functions in non-Npl human lung tissues. These results suggest that the degradation routes of ubiquitinated IGF-IR diverge in normal and Npl cells, and further support the involvement of IGF-IR signaling in cancer. Such a different route for IGF-IR processing might take place sometime during development, since both proteasome and lysosome pathways are active in fetal lung human fibroblasts, IMR90 cells

p53 continues to surprise: High levels of p53 can suppress apoptosis

David F. Calle

DMBT1 expression is down-regulated in breast cancer.

BACKGROUND: We studied the expression of DMBT1 (deleted in malignant brain tumor 1), a putative tumor suppressor gene, in normal, proliferative, and malignant breast epithelium and its possible relation to cell cycle. METHODS: Sections from 17 benign lesions and 55 carcinomas were immunostained with anti DMBT1 antibody (DMBTh12) and sections from 36 samples, were double-stained also with anti MCM5, one of the 6 pre-replicative complex proteins with cell proliferation-licensing functions. DMBT1 gene expression at mRNA level was assessed by RT-PCR in frozen tissues samples from 39 patients. RESULTS: Normal glands and hyperplastic epithelium in benign lesions displayed a luminal polarized DMBTh12 immunoreactivity. Normal and hyperplastic epithelium adjacent to carcinomas showed a loss of polarization, with immunostaining present in basal and perinuclear cytoplasmic compartments. DMBT1 protein expression was down-regulated in the cancerous lesions compared to the normal and/or hyperplastic epithelium adjacent to carcinomas (3/55 positive carcinomas versus 33/42 positive normal/hyperplastic epithelia; p = 0.0001). In 72% of cases RT-PCR confirmed immunohistochemical results. Most of normal and hyperplastic mammary cells positive with DMBTh12 were also MCM5-positive. CONCLUSIONS: The redistribution and up-regulation of DMBT1 in normal and hyperplastic tissues flanking malignant tumours and its down-regulation in carcinomas suggests a potential role in breast cancer. Moreover, the concomitant expression of DMTB1 and MCM5 suggests its possible association with the cell-cycle regulation

Pulmonary adenocarcinoma with massive lymphocytic infiltration: a case report with review of the literature of a rare histological entity with a peculiar biological behaviour

BACKGROUND: Tumors with a massive inflammatory infiltration are described in several organs. There is agreement about considering the inflammatory infiltration as the host's immune response to neoplastic cells; such neoplasms indeed have a better prognostic outcome than non-inflammatory counterparts. Only seventeen cases of pulmonary adenocarcinoma with massive lymphocytic infiltration (AMLI) have been reported in literature so far. CASE PRESENTATION: We present a case of pulmonary adenocarcinoma with massive lymphocytic infiltration occurring in a 71 years old male smoker. He came under our attention because of dyspnea, and underwent a left lower lobectomy. Histological examination showed a moderately differentiated (G2) acinar adenocarcinoma associated with a stromal desmoplastic reaction and a massive inflammatory infiltration, made up mostly of CD3+ lymphocytes. pTNM stage was pT2a, N0 (clinical stage: Ib).Molecular testing of EGFR gene showed no mutations and immunohistochemistry for ALK resulted negative.EBV infection was ruled out by EBV in situ hybridization. CONCLUSIONS: Literature review showed seventeen similar cases, with a 16/1 male/female ratio and a mean age of 70,2 years. In eight out of seventeen cases EBV-infection was demonstrated with immunohistochemical or molecular biology techniques.Similarly to the cases previously reported in literature our patient is a male smoker, without lymph node metastasis and he is still alive after a follow-up period of six months without recurrent or residual disease.Because of histological, biological and clinical peculiarity, we propose to take into account pulmonary adenocarcinomas with massive inflammatory infiltration for a separate pathological classificatio

Validation of an Engineered Cell Model for In Vitro and In Vivo HIF-1 alpha Evaluation by Different Imaging Modalities

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Synchronous pleural and peritoneal malignant mesothelioma : a case report and review of literature

The coexistence of mesothelioma and other primary malignancies has been previously reported in literature, but the finding of a pleural mesothelioma with a synchronous peritoneal mesothelioma has not been reported so far. We report a case of a 58-years-old woman that came to our attention for the incidental finding of an inguinal mass. Fine-needle biopsies of the mass and a thoracoscopy with pleural biopsies were performed, after imaging studies showed pleural thickenings suspicious for malignancy. Histological morphology and growth pattern were similar in both cases. Both tumors stained for calretinin, but only the pleural mesothelioma showed positivity for Wilms-Tumor 1 antibody. We tried to demonstrate with molecular biology techniques whether they were synchronous or one was the metastasis of the other, but our studies did not give informative results. The prognosis in this case is poor, and after 6 months the patient is still following a chemotherapy regimen, which is the only practicable approach given the extent of the disease

PAT-ChIP coupled with laser microdissection allows the study of chromatin in selected cell populations from paraffin-embedded patient samples

Background: The recent introduction of pathology tissue-chromatin immunoprecipitation (PAT-ChIP), a technique allowing chromatin immunoprecipitation from formalin-fixed and paraffin-embedded (FFPE) tissues, has expanded the application potential of epigenetic studies in tissue samples. However, FFPE tissue section analysis is strongly limited by tissue heterogeneity, which hinders linking the observed epigenetic events to the corresponding cellular population. Thus, ideally, to take full advantage of PAT-ChIP approaches, procedures able to increase the purity and homogeneity of cell populations from FFPE tissues are required. Results: In this study, we tested the use of both core needle biopsies (CNBs) and laser microdissection (LMD), evaluating the compatibility of these methods with the PAT-ChIP procedure. Modifications of the original protocols were introduced in order to increase reproducibility and reduce experimental time. We first demonstrated that chromatin can be prepared and effectively immunoprecipitated starting from 0.6-mm-diameter CNBs. Subsequently, in order to assess the applicability of PAT-ChIP to LMD samples, we tested the effects of hematoxylin or eosin staining on chromatin extraction and immunoprecipitation, as well as the reproducibility of our technique when using particularly low quantities of starting material. Finally, we carried out the PAT-ChIP using chromatin extracted from either normal tissue or neoplastic lesions, the latter obtained by LMD from FFPE lung sections derived from mutant K-rasv12transgenic mice or from human adeno- or squamous lung carcinoma samples. Well characterized histone post-translational modifications (HPTMs), such as H3K4me3, H3K27me3, H3K27Ac, and H3K9me3, were specifically immunoselected, as well as the CTCF transcription factor and RNA polymerase II (Pol II). Conclusions: Epigenetic profiling can be performed on enriched cell populations obtained from FFPE tissue sections. The improved PAT-ChIP protocol will be used for the discovery and/or validation of novel epigenetic biomarkers in FFPE human samples

Applicazione ai Tissue Microarray delle tecniche di immunoistochimica e di Ibridazione In Situ Fluorescente per la caratterizzazione immunofenotipica e citogenetica di linfoma a grandi cellule B diffuso

Obbiettivo Lo scopo di questo lavoro \ue8 stato la costruzione di un Tissue Microarray (TMA) pilota per la valutazione immunofenotipica e citogenetica di una casistica di linfoma a grandi cellule B diffuso (DLBCL), tramite analisi immunoistochimiche e di Ibridazione In Situ Fluorescente (FISH). Materiali e Metodi Abbiamo costruito il TMA utilizzando le biopsie linfonodali di 12 pazienti affetti da linfoma a grandi cellule B diffuso; ne abbiamo ottimizzato la costruzione per la lettura al microscopio a fluorescenza distanziando in maniera differenziale i carotaggi dello stesso caso da quelli del casi adiacenti mentre per mantenere la rappresentabilit\ue0 tissutale abbiamo inserito cinque carotaggi da 2 mm per campione. Al TMA abbiamo applicato cinque protocolli immunoistochimici (CD10, BCL6, MUM1, GCET1 e FOXP1) e un protocollo FISH (cMYC). Risultati I dati immunoistochimici sono stati elaborati secondo gli algoritmi di Hans e Choi: secondo il protocollo di Hans sono risultati 8 DLBCL con profilo immunofenotipico centro germinativo simile (GCB) e 4 DLBCL con profilo attivato (ABC); in accordo con l'algoritmo di Choi 7 DLBCL GCB e 5 DLBCL ABC. La conformit\ue0 dei dati immunoistochimici ottenuti \ue8 stata valutata confrontando i risultati con quelli delle indagini immunoistochimiche eseguite su sezione interna, al momento della diagnosi. Abbiamo ottenuto in questo modo una concordanza del 100% con l\u2019algoritmo di Hans e una concordanza del 92% con l\u2019algoritmo di Choi. L\u2019analisi di MYC non ha evidenziato la presenza di traslocazioni ma in tre casi \ue8 stato possibile rilevare polisomie del cromosoma 8. Conclusioni Questo studio ci ha permesso di definire i criteri metodologici per la progettazione e la costruzione di un TMA (con una concordanza del 100% rispetto ai dati ottenuti al momento della diagnosi) che potesse essere letto agevolmente al microscopio a fluorescenza, fornendo cos\uec una piattaforma di analisi ad alta resa per l'esecuzione di indagini immunoistochimiche e citogenetiche FISH

Histological evaluation of duodenal biopsies from coeliac patients : the need for different grading criteria during follow-up

Background: Coeliac disease is characterised by villous atrophy, which usually normalises after gluten withdrawal. Sometimes the revaluation of duodenal histology is required during follow-up, even if the methodology for comparing duodenal histology before and after introducing a gluten-free diet is not yet established. Our aim was to evaluate a novel criterion to compare duodenal histology in coeliac disease before and after gluten withdrawal. Methods: Duodenal biopsies from coeliac patients were retrospectively reviewed to compare duodenal histology at diagnosis and after at least one year on a gluten-free diet. Two different methods were used: the first was represented by the classical Marsh-Oberhuber score, the second compared the areas covered by each Marsh-Oberhuber grade and expressed as percentages, the final grade being calculated from the analysis of ten power fields per duodenal biopsy. Results: Sixty-nine patients (17 males 52 females, age at diagnosis 36\ub115 years) who underwent duodenal biopsies, were considered. According to the classical Marsh-Oberhuber scale, 32 patients did not present atrophy during follow-up while 37 showed duodenal atrophy, among whom 26 improved the grade of severity and 11 retained the same one. Of these latter, according to the second method, eight patients were considered improved, two showed a worsened duodenal damage and only one remained unchanged; the evaluation changed in 91 % of cases. Conclusions: The proposed semi-quantitative approach (i.e. the second method) for the evaluation of histology at follow-up provides additional information about the progression/regression of the mucosal damage