Klaus J. Schmitz

Activation of extracellular regulated kinases (ERK1/2) but not AKT predicts poor prognosis in colorectal carcinoma and is associated with k-ras mutations

Signal transduction and modulation represent central mechanisms in cellular processes such as cell-cycle regulation, oncogenesis, and apoptosis. The aim of this study was to determine the prognostic relevance of two kinases important in the regulation of cell proliferation and apoptosis in 135 colorectal cancer cases: AKT and extracellular regulated kinases (ERK1/2). We investigated the relationship of phospho-ERK1/2 (pERK1/2) and phospho-AKT (pAKT) with associated parameters (EGFR, COX-2, cyclin-D1), proliferative activity (Ki-67), and apoptosis (TUNEL) using immunohistochemistry. Additionally, the k-ras gene was screened for mutations to determine its putative association with ERK1/2 activation. Activation of ERK1/2 but not AKT correlated statistically with the presence of k-ras mutations (P = 0.015). Survival analysis of phospho-ERK1/2 immunoexpression showed a significant correlation with decreased overall survival (OS). The multivariate Cox regression analysis identified pERK1/2 as an independent prognostic parameter (P = 0.005). Activation of ERK1/2 in colorectal cancer may indicate aggressive tumor behavior and may constitute an independent prognostic factor. Furthermore, our data suggest that mutations of the k-ras oncogene may induce activation of ERK1/2. We propose immunohistochemical determination of pERK1/2 status as a promising candidate for the identification of high-risk patients who would benefit from new anticancer drugs targeting the ERK pathway.

Phosphorylation of p70S6 kinase predicts overall survival in patients with clear margin‐resected hepatocellular carcinoma

Background/Aims: The mammalian target of rapamycin (mTOR) inhibitors play a key role in regulating signal transduction by blocking the mTOR pathway and combining anticancer and immunosuppressive properties. This study was undertaken to determine the prevalence and clinicopathological relevance of phospho‐p70S6 (p‐p70S6) kinase in hepatocellular carcinoma (HCC) and to investigate the effects of rapamycin on HCC in vitro.

The T393C polymorphism in the gene GNAS1 of G protein is associated with survival of patients with invasive breast carcinoma

The GNAS1 locus encodes the G(alpha)s protein which stimulates the formation of cyclic AMP (cAMP). Subsequently the cAMP pathway mediates various pleiotropic effects including regulation of apoptosis and proliferation. We have recently shown that genotypes of the single nucleotide polymorphism (SNP) T393C in the gene GNAS1 are associated with survival of patients suffering from bladder, renal cell and colorectal carcinoma. In the present study, the genotypes of the T393C SNP were determined in 279 patients with invasive breast carcinoma. Comparing the genotypes with the overall survival as well as important clinico-pathological parameters showed that carriers of the T allele had a significantly less favourable course of the disease when compared to carriers of the homozygous CC genotype. In multivariate analysis the homozygous TT genotype was independently associated with a decreased overall survival. Our results suggest that the GNAS1 T393C SNP is a novel genetic host factor for disease progression in patients with invasive breast carcinoma.

AKR1B10 expression is associated with less aggressive hepatocellular carcinoma: a clinicopathological study of 168 cases

Background/Aims: The detoxification enzyme AKR1B10, a member of the aldo‐keto reductase superfamily, is discussed as a new biomarker candidate for hepatocellular carcinoma (HCC). Only rare clinicopathological data on AKRB1B10 in HCC exist. This retrospective study determines the diagnostic and prognostic relevance of AKR1B10 expression in HCC and its relationship to a series of clinicopathological parameters including underlying aetiological factors.

Differential expression of microRNA 181b and microRNA 21 in hyperplastic polyps and sessile serrated adenomas of the colon.

This study was designed to analyse the potential diagnostic value of miR-181b and miR-21 for discriminating hyperplastic polyps (HP) from sessile serrated adenomas (SSA) without cytologic dysplasia. Using real-time polymerase chain reaction expression levels of miR-181b and miR-21 in 18 HPs, 19 SSAs without cytologic dysplasia and 20 normal colonic mucosal specimens were examined. In addition, 20 colorectal cancers specimen were analysed for miR-181b expression. Data were normalised to RNU48 as an internal control. A differential expression of miR-181b and miR-21 was found in HPs, SSAs, and normal colonic mucosa with highest expression levels in SSAs. Levels of miR-181b but not miR-21 differed in HPs and normal mucosa. SSAs exhibited both significantly higher miR-181b levels (up to 2.01-fold; P < 0.001) and miR-21 levels (up to 1.82-fold; P = 0.011) than HPs. In contrast to HPs, SSAs are characterised by high levels of miR-181b and miR-21 expression. However, due to the overlap of values, miR-181b and miR-21 evaluation did not allow discrimination of the two lesions in every case.

Increased frequencies of CD8+ T lymphocytes recognizing wild-type p53-derived epitopes in peripheral blood correlate with presence of epitope loss tumor variants in patients with hepatocellular carcinoma.

Wild‐type (WT) sequence p53 peptides are attractive candidates for broadly applicable cancer vaccines. The aim of this study was to evaluate the potential of a WT p53‐based immunotherapeutic approach for patients with hepatocellular carcinoma (HCC). Circulating CD8+ T cells specific for WT p53149–157 and WT p53264–272 HLA‐A*0201 restricted epitopes were directly identified in the peripheral blood by the use of peptide/HLA‐A2.1 tetramers in 24 HCC patients. Cytotoxic T lymphocyte (CTL) activity after WT p53 peptide‐specific stimulation was assessed by analysis of granzyme B and interferon‐gamma mRNA transcription, using a quantitative real‐time polymerase chain reaction assay. Tumor immunophenotyping was performed to evaluate the p53 status, the expression of major histocompatibility complex (MHC) and costimulatory molecules in freshly isolated tumor cells. HCC patients exhibited significantly higher frequencies of WT p53‐specific memory CD8+ T cells and stronger WT p53‐specific CTL activity, when compared with healthy controls. Increased frequencies of p53‐specific CD8+ T cells and their activity correlated with selective HLA‐A2 allele loss and reduced costimulatory molecule expression of tumor cells. Moreover, augmented numbers of p53‐specific T cells coincided with high MHC class II expression in tumor cells but were inversely related to the T status of the tumor node metastasis staging system. Our results indicate the existence of natural immunosurveillance and tumor immune evasion, involving a T cell response against WT p53 tumor antigen in patients with HCC. These findings may have important implications for the future development of cancer vaccines.

Prognostic relevance of autophagy-related markers LC3, p62/sequestosome 1, Beclin-1 and ULK1 in colorectal cancer patients with respect to KRAS mutational status

BackgroundAutophagy is a cellular pathway that regulates transportation of cytoplasmic macromolecules and organelles to lysosomes for degradation. Autophagy is involved in both tumorigenesis and tumour suppression. Here we investigated the potential prognostic value of the autophagy-related proteins Beclin-1, p62, LC3 and uncoordinated (UNC) 51-like kinase 1 (ULK1) in a cohort of colorectal cancer (CRC) specimens.MethodsIn this study, we analysed the immunoexpression of the autophagy-related proteins p62, LC3, Beclin-1 and ULK1 in 127 CRC patients with known KRAS mutational status and detailed clinical follow-up.ResultsSurvival analysis of p62 staining showed a significant correlation of cytoplasmic (not nuclear) p62 expression with a favourable tumour-specific overall survival (OS). The prognostic power of cytoplasmic p62 was found in the KRAS-mutated subgroup but was lost in the KRAS wildtype subgroup. Survival analysis of Beclin-1 staining did not show an association with OS in the complete cohort. LC3 overexpression demonstrated a slight, though not significant, association with decreased OS. Upon stratifying cases by KRAS mutational status, nuclear (not cytoplasmic) Beclin-1 staining was associated with a significantly decreased OS in the KRAS-mutated subgroup but not in the KRAS wildtype CRCs. In addition, LC3 overexpression was significantly associated with decreased OS in the KRAS-mutated CRC subgroup. ULK1 expression was not correlated to survival.ConclusionsImmunohistochemical analyses of LC3, p62 and Beclin-1 may constitute promising novel prognostic markers in CRC, especially in KRAS-mutated CRCs. This strategy might help in identifying high-risk patients who would benefit from autophagy-related anticancer drugs.

Survivin is upregulated during liver regeneration in rats and humans and is associated with hepatocyte proliferation

Background: Survivin regulates cell division and inhibits apoptosis. Liver regeneration is a complex process involving both proliferation and apoptosis. The role of survivin is not well elucidated and no data exist in humans.

Resolved hypersensitivity myocarditis after ventricular circulatory assist

Hypersensitivity myocarditis is known to be a cardiac manifestation of a delayed-type hypersensitivity response caused by drug treatment. In heart transplantation candidates the incidence is elevated. We report the case of a patient with end-stage heart failure who underwent implantation of a left ventricular assist device as a bridge to transplantation. The histologic investigation of the left ventricular specimen obtained during device implantation revealed the diagnosis of a hypersensitivity myocarditis. Ten months later this lesion showed complete reversibility within specimens of the explanted heart, maybe as a result of the termination of inotropic therapy after implantation of the left ventricular assist device.

Increased expression of α-methylacyl-coenzyme A racemase (AMACR; p504s) and p16 in distal hyperplastic polyps

BackgroundHyperplastic polyps (HP) and sessile serrated adenomas (SSA) share morphological similarities. In this immunohistochemical study we chose a panel of potential relevant and promising biomarkers including α-methylacyl-coenzyme A racemase (AMACR; p504s), which is involved in the degradation of branched chained fatty acids derivates, and analysed a cohort of HPs and SSAs in order to identify different immunophenotypes in relation to lesion localisation.Methods154 specimen were carefully selected and a micro tissue array (TMA) was constructed. Immunohistochemistry of p16Ink4a, Ki67, α-methylacyl-coenzyme A racemase (AMACR; p504s), BRAF, CK 20, MLH1 and β-catenin was performed and and immunoexpression was compared among proximal and distal HPs as well as SSAs.ResultsNone of the markers revealed a differential expression among HPs and SSAs. However, the study demonstrates a significant overexpression of AMACR (p = 0.004) and p16Ink4a (p = 0.028) in distal HPs compared to proximal HPs. In addition AMACR overexpression was associated with increased p16Ink4a immunoexpression (p < 0.001).ConclusionsIn this study we describe differential AMACR and p16Ink4a in HPs in relation to their localisation. Distal HPs were characterized by AMACR and p16Ink4a overexpression in contrast to proximal HPs, although morphological identically. Thus AMACR overexpression points towards a pathobiological relevance of the protein in distal HPs. In context of recently published data this suggest distal HPs as potential precursor lesions of certain adenoma subtypes. However, at this point of time this finding remains speculative and needs to be confirmed by further studies.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1836116001066768