MiR-200a regulates epithelial to mesenchymal transition-related gene expression and determines prognosis in colorectal cancer patients.

BACKGROUND: MicroRNAs (miRNAs) regulate the biological properties of colorectal cancer (CRC) cells and might serve as potential prognostic factors and therapeutic targets. In this study, we therefore globally profiled miRNAs associated with E-cadherin expression in CRC cells in an attempt to identify miRNAs that are associated with aggressive clinical course in CRC patients. METHODS: Two CRC cell lines (Caco-2 and HRT-18) with different E-cadherin expression pattern were profiled for differences in abundance for more than 1000 human miRNAs using microarray technology. One of the most differentially expressed miRNAs, miR-200a was evaluated for its prognostic role in a cohort of 111 patients and independently validated in 217 patients of the Cancer Genome Atlas data set. To further characterise the biological role of miR-200a expression in CRC, in vitro miR-200a inhibition and overexpression were performed and the effects on cellular growth, apoptosis and epithelial-mesenchymal transition (EMT)-related gene expression were explored. RESULTS: In situ hybridisation specifically localised miR-200a in CRC cells. In both cohorts, a low miR-200a expression was associated with poor survival (P<0.05). Multivariate Cox regression analysis identified low levels of miR-200a expression as an independent prognostic factor with respect to cancer-specific survival (HR=2.04, CI=1.28-3.25, P<0.002). Gain and loss of function assays for miR-200a in vitro led to a significantly differential and converse expression of EMT-related genes (P<0.001.) A low expression of miR-200a was also observed in cancer stem cell-enriched spheroid growth conditions (P<0.05). CONCLUSIONS: In conclusion, our data suggest that low miR-200a expression is associated with poor prognosis in CRC patients. MiR-200a has a regulatory effect on EMT and is associated with cancer stem cell properties in CRC.

Validation of C-reactive protein levels as a prognostic indicator for survival in a large cohort of pancreatic cancer patients.

BACKGROUND: Recent evidence indicates that the host inflammatory response has an important role in the tumour progression. Elevated C-reactive protein (CRP) levels have been previously associated with poor prognosis in several cancer types including small-scale studies in pancreatic cancer (PC) patients. The purpose of the present study was to validate the prognostic impact of plasma CRP levels at date of diagnosis on cancer-specific survival (CSS) in a large cohort of PC patients. METHODS: Data from 474 consecutive patients with adenocarcinoma of the pancreas, treated between 2004 and 2012 at a single centre, were evaluated retrospectively. CSS was analysed using the Kaplan-Meier method. To evaluate the prognostic significance of plasma CRP levels, univariate and multivariate Cox analyses were applied. RESULTS: High plasma CRP levels at diagnosis were significantly associated with well-established prognostic factors, including high tumour stage and tumour grade and the administration of chemotherapy (P<0.05). In univariate analysis, we observed that a high plasma CRP level was a consistent factor for poor CSS in PC patients (hazard ratio (HR)=2.21; 95% confidence interval (CI)=1.68-2.92, P<0.001). In multivariate analysis, tumour stage, grade, administration of chemotherapy, a high neutrophil-lymphocyte ratio and the highest quartile of CRP levels (HR=1.60, 95% CI=1.16-2.21; P=0.005) were identified as independent prognostic factors in PC patients. CONCLUSION: In conclusion, we confirmed a significant association of elevated CRP levels with poor clinical outcome in PC patients. Our results indicate that the plasma CRP level might represent a useful marker for patient stratification in PC management.

Increased neutrophil-lymphocyte ratio is a poor prognostic factor in patients with primary operable and inoperable pancreatic cancer.

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) has been proposed as an indicator of systemic inflammatory response. Previous findings from small-scale studies revealed conflicting results about its independent prognostic significance with regard to different clinical end points in pancreatic cancer (PC) patients. Therefore, the aim of our study was the external validation of the prognostic significance of NLR in a large cohort of PC patients. METHODS: Data from 371 consecutive PC patients, treated between 2004 and 2010 at a single centre, were evaluated retrospectively. The whole cohort was stratified into two groups according to the treatment modality. Group 1 comprised 261 patients with inoperable PC at diagnosis and group 2 comprised 110 patients with surgically resected PC. Cancer-specific survival (CSS) was assessed using the Kaplan-Meier method. To evaluate the independent prognostic significance of the NLR, the modified Glasgow prognostic score (mGPS) and the platelet-lymphocyte ratio univariate and multivariate Cox regression models were applied. RESULTS: Multivariate analysis identified increased NLR as an independent prognostic factor for inoperable PC patients (hazard ratio (HR)=2.53, confidence interval (CI)=1.64-3.91, P<0.001) and surgically resected PC patients (HR=1.61, CI=1.02-2.53, P=0.039). In inoperable PC patients, the mGPS was associated with poor CSS only in univariate analysis (HR=1.44, CI=1.04-1.98). CONCLUSION: Risk prediction for cancer-related end points using NLR does add independent prognostic information to other well-established prognostic factors in patients with PC, regardless of the undergoing therapeutic modality. Thus, the NLR should be considered for future individual risk assessment in patients with PC.

Down-regulation of KRAS-interacting miRNA-143 predicts poor prognosis but not response to EGFR-targeted agents in colorectal cancer.

BACKGROUND: MicroRNA-143 (miRNA-143) is frequently down-regulated in colorectal cancer (CRC) and may influence CRC cell proliferation, apoptosis and sensitivity to 5-fluorouracil. mRNA encoded by the KRAS oncogene has been identified as a target of miRNA-143. However, the prognostic significance of miRNA-143 expression and the ability to predict patient response to epidermal growth factor receptor (EGFR)-targeted agents have not yet been explored. METHODS: We examined 77 CRC patients who were identified by pyrosequencing to have wild-type KRAS and were subsequently treated with EGFR-targeted therapy with the monoclonal antibodies cetuximab or panitumumab. MicroRNA-143 expression was measured in CRC tissue and corresponding non-neoplastic colon tissue by RT-PCR and its expression level was correlated with clinico-pathological characteristics. Univariate and multivariate analyses were used to calculate cancer-specific survival (CSS). The progression-free survival (PFS) and objective response rates on EGFR-targeted therapy were also evaluated. RESULTS: Down-regulation of miRNA-143 was observed in 47 out of 77 (61%) tumours. Multivariate Cox regression analysis identified low levels of miRNA-143 expression as an independent prognostic factor with respect to CSS (hazard ratio=1.92, confidence interval=1.1-3.4, P=0.024). A significant difference was also observed with regard to PFS on EGFR-targeted therapy (P=0.031), but there were no significant differences with regard to the objective response rates. CONCLUSION: Our data indicate that miRNA-143 expression levels serve as an independent prognostic biomarker for CRC in KRAS wild-type patients. No role for miRNA-143 expression as a predictive biomarker for EGFR-targeted agents could be identified. Given its negative impact on CSS and PFS, miRNA-143 represents a novel prognosticator and a promising drug target for patients with CRC.

KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program.

Novel therapeutic agents targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with colorectal carcinoma. However, these therapies are effective only in a subset of patients. Activating mutations in the KRAS gene are found in 30-40% of colorectal tumors and are associated with poor response to anti-EGFR therapies. Thus, KRAS mutation status can predict which patient may or may not benefit from anti-EGFR therapy. Although many diagnostic tools have been developed for KRAS mutation analysis, validated methods and standardized testing procedures are lacking. This poses a challenge for the optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Here we review the molecular basis of EGFR-targeted therapies and the resistance to treatment conferred by KRAS mutations. We also present guideline recommendations and a proposal for a European quality assurance program to help ensure accuracy and proficiency in KRAS mutation testing across the European Union.

Photosensitized killing of cultured fibroblasts from patients with peroxisomal disorders due to pyrene fatty acid-mediated ultraviolet damage.

The influence of pyrene-fatty acids on the resistance of cells to ultraviolet (UV) radiation was investigated in cultured fibroblasts from patients with five types of peroxisomal disorders. All showed reduced survival compared to control. The effect varied with the biochemical defect involved and the chain length of the pyrene fatty acid. Reduced survival was observed in cells deficient in plasmalogens (rhizomelic chondrodysplasia punctata) and in cells deficient in peroxisomal fatty acid oxidation (bifunctional enzyme deficiency), which accumulated pyrene-fatty acids. X-linked adrenoleukodystrophy fibroblasts accumulated pyrene-fatty acids and showed increased UV sensitivity only when exposed to longer-chain pyrene fatty acids. UV radiation resistance was lowest in cells with combined impairment of plasmalogen synthesis and fatty acid oxidation (Zellweger syndrome, neonatal adrenoleukodystrophy), suggesting that UV sensitivity correlates inversely with the ratio of plasmalogens to radical producing substances. Fibroblasts deficient in plasmalogens gained normal UV resistance when their plasmalogen levels were normalized by hexadecylglycerol. UV resistance increased when Zellweger cells were fused with X-linked adrenoleukodystrophy cells, and also when Zellweger cells belonging to different complementation groups were fused. The results provide leads to the pathogenesis of the multiple malformations associated with peroxisomal disorders and a method for the selection of cells in which the metabolic defect has been corrected.

Muscle-specific overexpression of lipoprotein lipase causes a severe myopathy characterized by proliferation of mitochondria and peroxisomes in transgenic mice.

In extrahepatic tissues lipoprotein lipase (LPL) hydrolyzes triglycerides thereby generating FFA for tissue uptake and metabolism. To study the effects of increased FFA uptake in muscle tissue, transgenic mouse lines were generated with a human LPL minigene driven by the promoter of the muscle creatine kinase gene. In these mice human LPL was expressed in skeletal muscle and cardiac muscle, but not in other tissues. In proportion to the level of LPL overexpression, decreased plasma triglyceride levels, elevated FFA uptake by muscle tissue, weight loss, and premature death were observed in three independent transgenic mouse lines. The animals developed a severe myopathy characterized by muscle fiber degeneration, fiber atrophy, glycogen storage, and extensive proliferation of mitochondria and peroxisomes. This degree of proliferation suggests that FFA play an important role in the biogenesis of these organelles. Our experiments indicate that LPL is rate limiting for the supply of muscle tissue with triglyceride-derived FFA. Improper regulation of muscle LPL can lead to major pathological changes and may be important in the pathogenesis of some human myopathies. Muscle-specific LPL transgenic mouse lines will serve as a useful animal model for the investigation of myopathies and the biogenesis of mitochondria and peroxisomes.

Peroxisomal bifunctional enzyme deficiency.

Peroxisomal function was evaluated in a male infant with clinical features of neonatal adrenoleukodystrophy. Very long chain fatty acid levels were elevated in both plasma and fibroblasts, and beta-oxidation of very long chain fatty acids in cultured fibroblasts was significantly impaired. Although the level of the bile acid intermediate trihydroxycoprostanoic acid was slightly elevated in plasma, phytanic acid and L-pipecolic acid levels were normal, as was plasmalogen synthesis in cultured fibroblasts. The latter three parameters distinguish this case from classical neonatal adrenoleukodystrophy. In addition, electron microscopy and catalase subcellular distribution studies revealed that, in contrast to neonatal adrenoleukodystrophy, peroxisomes were present in the patient's tissues. Immunoblot studies of peroxisomal beta-oxidation enzymes revealed that the bifunctional enzyme (enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase) was deficient in postmortem liver samples, whereas acyl-CoA oxidase and the mature form of beta-ketothiolase were present. Density gradient centrifugation of fibroblast homogenates confirmed that intact peroxisomes were present. Immunoblots of fibroblasts peroxisomal fractions showed that they contained acyl-CoA oxidase and beta-ketothiolase, but bifunctional enzyme was not detected. Northern analysis, however, revealed that mRNA coding for the bifunctional enzyme was present in the patient's fibroblasts. These results indicate that the primary biochemical defect in this patient is a deficiency of peroxisomal bifunctional enzyme. It is of interest that the phenotype of this patient resembled neonatal adrenoleukodystrophy and would not have been distinguished from this disorder by clinical study alone.

mRNA expression patterns indicate CD30 mediated activation of different apoptosis pathways in anaplastic large cell lymphoma but not in Hodgkin's lymphoma.

One of the main functions of the tumor necrosis factor receptor (TNFR) family is induction of apoptosis. CD30, a member of the TNFR superfamily is overexpressed in highly proliferating tumors such as anaplastic large cell lymphoma (ALCL) and Hodgkin's lymphoma (HL). CD30 stimulation leads to apoptosis and growth arrest in cultured ALCL, but not in Hodgkin-Reed-Sternberg cells. To identify changes in the transcriptional program responsible for these opposing effects, we performed gene expression analysis in CD30-stimulated ALCL (Karpas 299) and HL (KM-H2) cell lines using cDNA microarrays. Selected genes were validated by real-time PCR. Hierarchical clustering was applied to the whole dataset and separated the cell lines clearly with respect to their origin. In HL, there were only minor CD30-specific alterations, whereas ALCL unequivocally showed a pronounced CD30-specific transcriptional response. Ninety-three genes (6.6% of total) were deregulated by more than a factor of two after CD30 stimulation in ALCL cells. The majority of genes identified are involved in cell cycle regulation and apoptosis. mRNA expression patterns further indicate that in contrast to HL, CD30 stimulation in ALCL induces cell death via the CD95-CD95 ligand (CD95L) pathway and the TNF-R1/TNF-R2 crosstalk. These data provide a detailed view on the transcriptional changes upon CD30 stimulation and may explain the observed functional differences of HL and ALCL.

Critical issues in the identification and management of patients with hereditary non-polyposis colorectal cancer.

Inherited defects of the DNA mismatch repair system are the underlying cause of the hereditary non-polyposis colorectal cancer (HNPCC) syndrome and are responsible for 3-4% of all cases of colorectal cancer. The HNPCC syndrome also carries the risk of development of additional malignancies such as endometrial, stomach, small bowel, ovarian, pancreas, ureter, renal pelvis, biliary tract and brain tumours. Amsterdam I and II criteria have been developed to clinically identify affected families. The revised Bethesda criteria function to select patients whose tumours should be investigated for microsatellite instability, the molecular hallmark of defects of the DNA mismatch repair proteins such as hMLH1 and hMSH2. Microsatellite instability-positive cases should be investigated for germline defects in the respective genes. This facilitates identification of affected family members that have to be included in special surveillance programmes, while unaffected family members are spared the physical discomfort and psychological burden of cancer surveillance. In this article, strategies for effective clinical as well as genetic detection of affected individuals, surveillance and appropriate preventive measures are discussed. Open questions include the role of chemoprevention, preventive surgical procedures, new endoscopic procedures as well as non-invasive 'virtual colonoscopy' and the exact implications of some mutations of the DNA mismatch repair genes. Perhaps most importantly, efforts should be made to more efficiently transfer information about the HNPCC syndrome and the cancer risk associated with it from the specialists to primary health care providers and the general public.

A stress-induced early innate response causes multidrug tolerance in melanoma.

Acquired drug resistance constitutes a major challenge for effective cancer therapies with melanoma being no exception. The dynamics leading to permanent resistance are poorly understood but are important to design better treatments. Here we show that drug exposure, hypoxia or nutrient starvation leads to an early innate cell response in melanoma cells resulting in multidrug resistance, termed induced drug-tolerant cells (IDTCs). Transition into the IDTC state seems to be an inherent stress reaction for survival toward unfavorable environmental conditions or drug exposure. The response comprises chromatin remodeling, activation of signaling cascades and markers implicated in cancer stemness with higher angiogenic potential and tumorigenicity. These changes are characterized by a common increase in CD271 expression concomitantly with loss of differentiation markers such as melan-A and tyrosinase, enhanced aldehyde dehydrogenase (ALDH) activity and upregulation of histone demethylases. Accordingly, IDTCs show a loss of H3K4me3, H3K27me3 and gain of H3K9me3 suggesting activation and repression of differential genes. Drug holidays at the IDTC state allow for reversion into parental cells re-sensitizing them to the drug they were primarily exposed to. However, upon continuous drug exposure IDTCs eventually transform into permanent and irreversible drug-resistant cells. Knockdown of CD271 or KDM5B decreases transition into the IDTC state substantially but does not prevent it. Targeting IDTCs would be crucial for sustainable disease management and prevention of acquired drug resistance.

A stress-induced early innate response causes multidrug tolerance in melanoma.

Correction to: Oncogene (2015) 34, 4448­4459; doi:10.1038/onc.2014.372; published online 24 November 2014. In this article, published online 24 November 2014, the authors have noticed that the latest supplementary information was not used. The corrected supplementary information (Supplementary Materials) appears online together with this corrigendum. The authors would like to apologise for any inconvenience this may cause

Cloning and tissue expression of two cDNAs encoding the peroxisomal 2-enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase in the guinea pig liver.

The 2-enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase (HD) is the second enzyme of the peroxisomal beta-oxidation pathway. In human and rat, only one HD mRNA has been so far detected in the liver. This paper reports for the first time in a mammal species, the guinea pig, the cloning and sequencing of two cDNAs encoding an HD. The 3,274 nucleotide-cDNA is a strictly identical but longer copy of the 2,494 nucleotide-form. A 2,178 bp-open reading frame encodes a protein of 726 amino acids (M(r) 79.3 kDa) with the peroxisomal-targeting signal (tripeptide SKL) at the carboxyterminus. Northern blot analysis of HD mRNA identified three mRNAs of respective sizes 3.5, 2.6 and 1.6 kb in the guinea pig liver and kidneys.

Neonatal seizures and retardation in a girl with biochemical features of X-linked adrenoleukodystrophy: a possible new peroxisomal disease entity.

Neonatal hypotonia, seizures beginning at 5 days, and severe retardation were noted in a girl with normal karyotype and biochemical evidence of impaired adrenal function. Postmortem examination at 14 months revealed malformative and destructive lesions of central gray and white matter, atrophy of adrenal cortex with striated adrenocortical cells, hepatic fibrosis, and PAS-positive macrophages in several organs. Pathologically and clinically, this patient most closely approximated neonatal adrenoleukodystrophy (ALD) and differed strikingly from X-linked childhood ALD. In contrast, biochemical changes resembled the abnormalities observed in X-linked ALD and differed from those in the neonatal form. The very-long-chain fatty acid accumulation characteristic of both disorders was demonstrated, but unlike neonatal ALD, the levels or metabolism of plasmalogens, pipecolic acid, phytanic acid, and bile acid intermediates were normal, and peroxisomes in a liver biopsy specimen were present in normal number and appeared enlarged. While the case resembles the recently reported entity of peroxisomal acyl-CoA oxidase deficiency, assignment to this category was excluded by immunoblot studies on postmortem liver, which revealed normal amounts of this enzyme. Correlation of clinical, morphologic, and biochemical data suggests that this case is an example of a so-far undescribed entity, and reinforces the concept that the phenotypic spectrum of peroxisomal disorders is wider than realized.

Muscle-specific overexpression of human lipoprotein lipase in mice causes increased intracellular free fatty acids and induction of peroxisomal enzymes.

A transgenic mouse model for peroxisomal and mitochondrial induction caused by increased uptake of fatty acids in muscle was established. Transgenic mouse lines were generated using a human lipoprotein lipase (LPL) mini gene (3-20 copies) driven by the promoter of the muscle creatine kinase gene. Expression of human LPL was only observed in skeletal and cardiac muscle. In proportion to the level of LPL overexpression increased LPL activity in skeletal (up to 24-fold) and cardiac (up to three-fold) muscle, decreased plasma triglyceride levels, elevated free fatty acid (FFA) uptake by muscle tissue, weight loss (due to a reduction in muscle mass as well as adipose tissue mass) and premature death were observed. A remarkable increase in the number of mitochondria and peroxisomes was detected using oxide-electron microscopy. Proliferation of mitochondria and peroxisomes was confirmed by a dose-dependent increase of marker enzyme activity (succinate-dehydrogenase and catalase). In addition, peroxisomal acyl-CoAse enzyme protein was markedly elevated whereas mRNA was increased only up to two-fold. No changes in peroxisomal proliferator activated receptor alpha mRNA was found. This degree of proliferation and enzyme activity of mitochondria and peroxisomes suggests that FFA play an important role in the induction of these organelles. In addition, myopathy characterized by excessive glycogen storage, muscle fiber degeneration, and fiber atrophy with centralization of nuclei, mimicking several forms of human myopathies was noted. Our results imply that improper regulation of muscle LPL leading to increased fatty acid levels in muscle can cause severe pathological changes. This effect may be important in the pathogenesis of human myopathies. We conclude that these transgenic mouse lines could serve as a useful animal model for the investigation of myopathies and the effects of fatty acids on the induction of mitochondria and peroxisomes.

Gallium-67-citrate scintigraphy of high-grade T-cell non-Hodgkin's lymphoma.

Scintigraphy with 67Ga-citrate indicated the transition of an orbital pseudotumor into a lymphoma by a distinct increase in 67Ga avidity. The patient initially presented with a pseudotumor in the right orbit that was verified by CT and MRI. It was caused by a chronic reactive lymphocytic inflammation extending from the lacrimal gland. At that time, scintigraphy was negative. Six and a half weeks later, the tumor had not responded to therapy and scintigraphy then showed a striking increase in gallium avidity. Consequently the tumor was excised and histology ultimately revealed a high-grade non-Hodgkin's T-cell lymphoma.

Presence of mycobacterial DNA in sarcoidosis.

In 11 of 35 clinically proven cases of sarcoidosis, we detected DNA sequences coding for the mycobacterial 65-kDa antigen. In four cases, the sequences were homologous to Mycobacterium avium; seven sequences were related to other nontuberculous Mycobacteria. The insertion sequence 1110, characteristic for Mycobacterium avium, was present in three cases. The insertion sequence 6110 of the Mycobacterium tuberculosis complex (M tuberculosis, africanum, bovis, BCG) was not detectable in any of the 11 cases, ruling out the presence of members of the Mycobacterium tuberculosis complex. Therefore, it seems reasonable to speculate about a mycobacterial cause in some cases of sarcoidosis.

Nasopharyngeal angiofibroma: an APC-gene-associated tumor?

Nasopharyngeal angiofibromas are extremely rare, locally invasive tumors of unknown cause exclusively occurring in male adolescents. Recently, 6 cases have been reported in patients with familial adenomatous polyposis coli (Gardners syndrome). Mutations or allelic loss of the adenomatous polyposis coli (APC) gene have therefore been implied in the pathogenesis of nasopharyngeal angiofibroma. The authors analyzed 11 cases of nasopharyngeal angiofibromas from 9 male patients for mutations in the mutation cluster region and allelic loss of the APC gene. Six were primary tumors; 2 first recurrences; and 1, primary tumor with 2 recurrences. Direct sequence analysis was performed on several overlapping polymerase chain reaction (PCR) products. Detection of allelic loss was performed by restriction length polymorphism analysis at a polymorphic locus. No mutation was detected in 11 tumors of 9 different patients. None of the 9 informative (heterozygous) cases carried an allelic loss. We conclude that alterations of the APC gene do not play a major role in the development of nasopharyngeal angiofibroma. The coincidence of nasopharyngeal angiofibromas and adenomatous polyposis coli in some families implies the possibility that another gene in this region might be responsible for the development of nasopharyngeal angiofibromas. HUM PATHOL 31:1411:1413.

Extramedullary T cell lymphoblastic transformation of chronic myeloid leukaemia successfully treated with matched unrelated donor bone marrow transplantation.

Chronic myeloid leukaemia (CML) inevitably terminates in blast crisis (BC) which is of myeloid phenotype in approximately two-thirds and B-lymphoid in one-third of patients. T cell BC is rare and associated with poor prognosis. We describe the case of a 48-year-old woman with extramedullary T cell lymphoblastic transformation. After treatment with combination chemotherapy she achieved a second chronic phase and underwent an allogeneic BMT from an HLA-matched unrelated donor. At 30 months follow-up she is still in complete molecular remission and in good clinical condition. We conclude that unrelated donor BMT should be considered as a therapeutic option for patients with extramedullary BC.