Correction: Generation and Characterisation of Cisplatin-Resistant Non-Small Cell Lung Cancer Cell Lines Displaying a Stem-Like Signature.

[This corrects the article DOI: 10.1371/journal.pone.0054193.].

Novel immunohistochemical markers differentiate intrahepatic cholangiocarcinoma from benign bile duct lesions.

AIMS: The distinction between intrahepatic cholangiocarcinoma (ICC) and benign bile duct lesions can be challenging. Using our previously identified potential biomarkers for ICC, we examined whether these are useful for the differential diagnosis of ICC, bile duct adenoma and reactive bile duct proliferations in an immunohistochemical approach and identified a diagnostic marker panel including known biomarkers. METHODS: Subjects included samples from 77 patients with ICC, 33 patients with bile duct adenoma and 47 patients with ductular reactions in liver cirrhosis. Our previously identified biomarkers (stress-induced phosphoprotein 1 (STIP1), SerpinH1, 14-3-3Sigma) were tested immunohistochemically following comparison with candidates from the literature (cluster of differentiation 56, heat shock protein (HSP)27, HSP70, B-cell-lymphoma2, p53, ki67). RESULTS: The expression of SerpinH1 and 14-3-3Sigma was significantly higher in ICC than in bile duct adenomas and ductular reactions (p<0.05), whereas STIP1 expression was significantly higher (p<0.05) in ICC than in ductular reactions, but the difference to the bile duct adenoma group was not significant. A panel of the biomarker SerpinH1, 14-3-3Sigma and ki67 (≥2 marker positive) showed a high diagnostic accuracy (sensitivity 87.8%, specificity 95.9%, accuracy 91.8%) in the differential diagnosis of ICC versus non-malignant bile duct lesions. CONCLUSIONS: This suggests that 14-3-3Sigma and SerpinH1 may be useful in the differential diagnosis of malignant, benign and reactive bile duct lesions in addition to ki67 where a cut-off of >5% might be used for the distinction of malignant and non-malignant lesions.

Differential proteomic and tissue expression analyses identify valuable diagnostic biomarkers of hepatocellular differentiation and hepatoid adenocarcinomas.

The exact discrimination of lesions with true hepatocellular differentiation from secondary tumours and neoplasms with hepatocellular histomorphology like hepatoid adenocarcinomas (HAC) is crucial. Therefore, we aimed to identify ancillary protein biomarkers by using complementary proteomic techniques (2D-DIGE, label-free MS). The identified candidates were immunohistochemically validated in 14 paired samples of hepatocellular carcinoma (HCC) and non-tumourous liver tissue (NT). The candidates and HepPar1/Arginase1 were afterwards tested for consistency in a large cohort of hepatocellular lesions and NT (n = 290), non-hepatocellular malignancies (n = 383) and HAC (n = 13). Eight non-redundant, differentially expressed proteins were suitable for further immunohistochemical validation and four (ABAT, BHMT, FABP1, HAOX1) for further evaluation. Sensitivity and specificity rates for HCC/HAC were as follows: HepPar1 80.2%, 94.3% / 80.2%, 46.2%; Arginase1 82%, 99.4% / 82%, 69.2%; BHMT 61.4%, 93.8% / 61.4%, 100%; ABAT 84.4%, 33.7% / 84.4%, 30.8%; FABP1 87.2%, 95% / 87.2%, 69.2%; HAOX1 95.5%, 36.3% / 95.5%, 46.2%. The best 2×/3× biomarker panels for the diagnosis of HCC consisted of Arginase1/HAOX1 and BHMT/Arginase1/HAOX1 and for HAC consisted of Arginase1/FABP1 and BHMT/Arginase1/FABP1. In summary, we successfully identified, validated and benchmarked protein biomarker candidates of hepatocellular differentiation. BHMT in particular exhibited superior diagnostic characteristics in hepatocellular lesions and specifically in HAC. BHMT is therefore a promising (panel based) biomarker candidate in the differential diagnostic process of lesions with hepatocellular aspect.

A structured proteomic approach identifies 14-3-3Sigma as a novel and reliable protein biomarker in panel based differential diagnostics of liver tumors.

Hepatocellular carcinoma (HCC) is a major lethal cancer worldwide. Despite sophisticated diagnostic algorithms, the differential diagnosis of small liver nodules still is difficult. While imaging techniques have advanced, adjuvant protein-biomarkers as glypican3 (GPC3), glutamine-synthetase (GS) and heat-shock protein 70 (HSP70) have enhanced diagnostic accuracy. The aim was to further detect useful protein-biomarkers of HCC with a structured systematic approach using differential proteome techniques, bring the results to practical application and compare the diagnostic accuracy of the candidates with the established biomarkers. After label-free and gel-based proteomics (n=18 HCC/corresponding non-tumorous liver tissue (NTLT)) biomarker candidates were tested for diagnostic accuracy in immunohistochemical analyses (n=14 HCC/NTLT). Suitable candidates were further tested for consistency in comparison to known protein-biomarkers in HCC (n=78), hepatocellular adenoma (n=25; HCA), focal nodular hyperplasia (n=28; FNH) and cirrhosis (n=28). Of all protein-biomarkers, 14-3-3Sigma (14-3-3S) exhibited the most pronounced up-regulation (58.8×) in proteomics and superior diagnostic accuracy (73.0%) in the differentiation of HCC from non-tumorous hepatocytes also compared to established biomarkers as GPC3 (64.7%) and GS (45.4%). 14-3-3S was part of the best diagnostic three-biomarker panel (GPC3, HSP70, 14-3-3S) for the differentiation of HCC and HCA which is of most important significance. Exclusion of GS and inclusion of 14-3-3S in the panel (>1 marker positive) resulted in a profound increase in specificity (+44.0%) and accuracy (+11.0%) while sensitivity remained stable (96.0%). 14-3-3S is an interesting protein biomarker with the potential to further improve the accuracy of differential diagnostic process of hepatocellular tumors. This article is part of a Special Issue entitled: Medical Proteomics.

Generation and characterisation of cisplatin-resistant non-small cell lung cancer cell lines displaying a stem-like signature.

INTRODUCTION: Inherent and acquired cisplatin resistance reduces the effectiveness of this agent in the management of non-small cell lung cancer (NSCLC). Understanding the molecular mechanisms underlying this process may result in the development of novel agents to enhance the sensitivity of cisplatin. METHODS: An isogenic model of cisplatin resistance was generated in a panel of NSCLC cell lines (A549, SKMES-1, MOR, H460). Over a period of twelve months, cisplatin resistant (CisR) cell lines were derived from original, age-matched parent cells (PT) and subsequently characterized. Proliferation (MTT) and clonogenic survival assays (crystal violet) were carried out between PT and CisR cells. Cellular response to cisplatin-induced apoptosis and cell cycle distribution were examined by FACS analysis. A panel of cancer stem cell and pluripotent markers was examined in addition to the EMT proteins, c-Met and ß-catenin. Cisplatin-DNA adduct formation, DNA damage (γH2AX) and cellular platinum uptake (ICP-MS) was also assessed. RESULTS: Characterisation studies demonstrated a decreased proliferative capacity of lung tumour cells in response to cisplatin, increased resistance to cisplatin-induced cell death, accumulation of resistant cells in the G0/G1 phase of the cell cycle and enhanced clonogenic survival ability. Moreover, resistant cells displayed a putative stem-like signature with increased expression of CD133+/CD44+cells and increased ALDH activity relative to their corresponding parental cells. The stem cell markers, Nanog, Oct-4 and SOX-2, were significantly upregulated as were the EMT markers, c-Met and ß-catenin. While resistant sublines demonstrated decreased uptake of cisplatin in response to treatment, reduced cisplatin-GpG DNA adduct formation and significantly decreased γH2AX foci were observed compared to parental cell lines. CONCLUSION: Our results identified cisplatin resistant subpopulations of NSCLC cells with a putative stem-like signature, providing a further understanding of the cellular events associated with the cisplatin resistance phenotype in lung cancer.

ERCC1 RNA expression in peripheral blood predicts minor histopathological response to neoadjuvant radio-chemotherapy in patients with locally advanced cancer of the esophagus.

OBJECTIVE: The aim of this study was to determine the gene is spelled excision repair cross-complementing gene 1 (ERCC1) RNA-expression in peripheral blood as a non-invasive molecular predictor of response to neoadjuvant radio-chemotherapy in patients with locally advanced cancer of the esophagus. BACKGROUND: Only patients with locally advanced cancer of the esophagus with a major histopathological response to neoadjuvant radio-chemotherapy benefit from this treatment. No non-invasive molecular marker exists that can reliably predict response to neoadjuvant therapy in this disease. To improve the treatment of patients with cancer of the esophagus, molecular predictors of response are desperately needed. METHODS: Blood samples were drawn from 29 patients with esophageal cancer prior to neoadjuvant radio-chemotherapy. After extraction of cellular tumor-RNA from blood samples, quantitative expression analysis of ERCC1 was done by real-time reverse transcription polymerase chain reaction. RESULTS: Nineteen (65.5%) patients showed a minor and ten (34.5%) a major histopathological response to neoadjuvant therapy. ERCC1 expression in blood of patients was detectable in 82.8%. The median ERCC1 expression was 0.62 (minimum 0.00, maximum 2.48) in minor responders and 0.24 (minimum 0.00, maximum 0.45) in major responders (p = 0.004). No significant associations were detectable between ERCC1 levels and patients' clinical variables. Relative ERCC1 levels above 0.452 were not associated with major histopathological response (sensitivity, 68.4; specificity, 100%), and 13 of 19 patients with minor response could be unequivocally identified. CONCLUSION: Minor responders to the applied therapy show a significant higher ERCC1 expression level in their blood compared to major responders. ERCC1 appears to be a highly specific non-invasive predictor of response to neoadjuvant therapy in esophageal cancer.

Failure in downregulation of intratumoral survivin expression following neoadjuvant chemoradiation in esophageal cancer.

INTRODUCTION: Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis associated with locally advanced esophageal cancer. However, only patients with a major histopathologic response to neoadjuvant therapy will have a significant survival benefit. Predictive markers to allow individualization of multimodality treatment could be very helpful. We aimed to examine the association of survivin protein expression, an inhibitor of apoptosis, with histopathologic response to neoadjuvant chemoradiation and prognosis in patients with esophageal cancer. PATIENTS & METHODS: A total of 59 patients with esophageal cancer (clinical tumor stage 2-4, N(x), M(0)) received neoadjuvant chemoradiation followed by transthoracic en bloc esophagectomy. Histomorphologic regression was defined as major response when resected specimens contained less than 10% vital tumor cells. Intratumoral survivin expression was determined by immunohistochemistry in pretherapeutic biopsies and post-therapeutic resection specimens and correlated with clinicopathologic parameters. RESULTS: The pretherapeutic intratumoral survivin protein expression was not associated with any clinicopathologic factor. Survivin protein expression decreased significantly during neoadjuvant therapy, showing lower levels in post-therapeutic tumor samples (p < 0.01). Elevated postoperative survivin levels were significantly associated with a higher pathologic tumor stage after neoadjuvant therapy (ypT) category (p < 0.01), a poorer histopathologic response (p < 0.01) and a shorter overall survival (p < 0.028). CONCLUSION: Intratumoral survivin protein expression was significantly downregulated during neoadjuvant therapy of esophageal cancers. Elevated survivin levels after preoperative therapy were significantly associated with a minor histopathologic response and prognosis. Therefore, failure in downregulation of intratumoral survivin expression following neoadjuvant chemoradiation in esophageal cancer needs therapeutic strategies to reduce survivin expression or block survivin-mediated pathways to increase the histopathologic response rate and prognosis.