Mutational status of KRAS and MMR genes in a series of colorectal carcinoma cases.

BACKGROUND: The KRAS gene mutation is the most common somatic change in colorectal carcinoma (CRC) and is predictive of resistance to anti-epidermal growth factor receptor (EGFR) therapy in the metastatic forms. Microsatellite instability (MSI), a mismatch repair (MMR) system defect, accounts for 15-20% of all CRCs, more frequent in early stages. CRCs with MSI present better prognosis, a distinct histopathological aspect and a different response to chemotherapy. Patients with both KRAS wild type and MSI have a reduced risk of dissemination and recurrence. MATERIALS AND METHODS: Our study included formalin-fixed paraffin-embedded tissue samples from 40 patients with metastatic CRCs, aged between 40 and 71 years old, gender (males/females) ratio 2.33:1. The MMR proteins were analyzed using an indirect bistadial immunohistochemical (IHC) technique with monoclonal antibodies. KRAS mutations were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: Of the 40 tumors analyzed, 40% presented KRAS mutations located in codon 12 or codon 13. IHC expression of MMR proteins revealed a microsatellite stable status in 35 cases, including 15 cases with mutated KRAS. MSI status was identified in five cases (four with KRAS wild type). All MSI tumors had a poorer histological differentiation and four cases revealed a mucinous phenotype. Eighty percent of the patients with MSI status were older women. CONCLUSIONS: Our study demonstrates a 20% frequency of mutated KRAS in MSI CRCs, the incidence of KRAS mutations being inversely correlated with MSI status in these tumors. MMR protein deficient CRCs tend to occur in older females, have a poorer differentiation and are frequently associated with KRAS wild type.

Hematology references for three laboratory mice strains.

The paper contains reference data for the main haematologic indicators from three strains of conventional mice: Balb/c, C57BL/6 and CD1. These data listed include the mean and the standard deviation of the studied values. The animals used were divided by sex (sex ratio 1:1) and age. The study was performed in standard conditions. These strains were chosen as they are widely used for preclinical evaluations. Therefore, our data are expected to be useful for investigators conducting qualitative and quantitative toxicity studies in these mice.

Foxp3 and IL17 expression in tumor infiltrating lymphocytes (TIL) and tumor cells - correlated or independent factors?

Tumor infiltrating lymphocytes (TIL), as a microenvironment component were studied in various epithelial tumors, with contradictory results. Recent data about regulatory T-cells (Treg) revealed new explanations for pro- and anti-tumor implications of TIL. Tregs immunoprofile was recently completed with Foxp3 expression. A T-cell fraction (Th) is producing cytokine IL17 and is now considered acting in tumor progression. Our study aimed to analyze immunohistochemically (IHC) Foxp3+ and IL17 expression in resected lung adenocarcinomas, since they could become possible targets in the antitumor immunotherapy. The studied material was represented by paraffin-embedded tumor fragments from 59 patients with TIL identified on HE staining. The antibodies used were Foxp3 and IL17. The statistical analysis used logistical regression on SPSS19 software (Chicago, IL, USA). TIL was usually mild or scarce. A positive statistic correlation resulted between the amounts of TIL in peritumoral and intratumoral location but without correlation to histopathological grading. Foxp3 and IL17 were present in TIL lymphocytes, tumor cells and fibroblasts; IL17 was expressed also in periendothelial cells (PEC). Foxp3 positivity was significantly correlated for lymphocytes÷tumor cells, lymphocytes÷fibroblasts and tumor cells÷fibroblasts, suggesting their concerted action. Tumor cells and lymphocytes Foxp3 expression was inversely correlated with the amount of TIL. Between lymphocytic Foxp3 and PEC IL17, we found a weak negative correlation. The TIL had a quite positive correlation with PEC IL17. In these conditions, Foxp3 could be a mediator of the tumor cells inhibitory aggression upon the immune system and could be used as a molecular target for biological antitumor therapy.

Cellular immunophenotypes in human embryonic, fetal and adult heart.

The cellular immunoprofile of cardiac dysfunctions and lesions of ischemic etiology are insufficiently studied to date, especially regarding the contribution of non-cardiomyocytic structures. Aiming to explore this immunoprofile, we used immunohistochemistry applied on embryonic, fetal and adult normal or ischemic myocardium. We observed a decrease of smooth muscle alpha-actin expression in fetal vs. embryonic cardiomyocytes, its absence in normal adult myocardium and its intense expression in the fibrotic scars of ischemic myocardium. DDR2 and vimentin, which are present in the interstitial cells and cardiomyocytes of the embryo, fetus and normal adult heart, are absent in the fibrotic scar tissue and cicatricial infarction, the latter expressing smooth muscle alpha-actin and CD34. This suggested that myofibroblasts and not local fibroblasts that participate in ischemic remodeling. An EGFR-positive vascular network was better represented in the ischemic heart than in the adult normal one, a fact possibly related to EGFR implication in cardiac ischemic pre- and post-conditioning. Therefore, cardiomyocytes and non-cardiomyocytic cells have an undulating immunoprofile according to the intrauterine life stage or age after birth, and a variable contribution in cardiac lesions, mostly in ischemic ones.

Prognostic and predictive significance of the bcl-2/IgH translocation in malignant follicular lymphomas.

BACKGROUND: The t(14;18) translocation, which leads to an overproduction of the bcl-2 protein, supposedly occurs in almost all follicular lymphomas (FL) and can be detected by FISH methods or by PCR. Its detection is useful in monitoring the response to therapy and in assessing minimal residual disease in bone marrow. Recently it was observed that the translocation could become negative after treatment. The prognostic and predictive significance of this fluctuation is not entirely understood. AIM: We intended to find significant correlations among morphological features, histological grades, immunohistochemical findings, and cytogenetical aberrations in malignant follicular lymphomas, in order to identify the prognostic and predictive value of the bcl-2/IgH translocation in these malignancies. MATERIAL AND METHODS: We conducted a study on 79 patients with follicular lymphomas. The study was carried out on tissue samples selected from the "Victor Babes" National Institute of Pathology files. These samples were tested by immunohistochemistry and FISH. RESULTS: Most of the cases (65.2%) were low-grade FL (grade 1-2). Approximately 58.8% of cases in the FISH study group presented t(14;18). In 66.6% of the cases with t(14;18), the immunohistochemical reaction for bcl-2 protein was positive. A significant positive correlation was found between the IHC positivity for bcl-2 and t(14;18) detected by FISH (p=0.04). CONCLUSIONS: Bcl-2 t(14;18) plays an important role in the pathogenesis of follicular lymphoma. FISH is an important tool in the diagnosis, treatment and follow up of these malignancies, since the immunohistochemical testing is negative in a significant proportion of cases.