In Vitro Expression of Cytokeratin 19 in Adipose-Derived Stem Cells Is Induced by Epidermal Growth Factor

BACKGROUND Cytokeratin 19 (CK19) is a typical epithelial marker. In this study, we determined whether epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) could enhance CK19 expression in adipose-derived stem cells (ADSCs), thereby inducing the differentiation of ADSCs into epithelial-like cells. MATERIAL AND METHODS ADSCs were isolated from perinephric fat, and the expression of CD29, CD90, and CD105 was confirmed. Following isolation, ADSCs were cultured in static medium or medium containing EGF or bFGF. RESULTS Flow cytometry revealed that EGF and bFGF could alter mesenchymal stem cell markers as well as the cell cycle of ADSCs. Western blotting and immunofluorescence revealed that after 14 days, EGF treatment enhanced the expression of CK19 in ADSCs. CONCLUSIONS Our findings offer important insight for the clinical use of ADSCs in the generation of epithelial-like cells in the future.

Epigenetic modifications in salivary glands from patients with Sjögren's syndrome affect cytokeratin 19 expression

Sjögren's syndrome (SS) is a chronic autoimmune epithelitis, and several lines of experiments indicate that multifactorial factors contribute to salivary gland epithelial cells (SGEC) dysfunctions including a combination of environmental factors, lymphocytic infiltrations, genetic predispositions as well as epigenetic defects. Such statement is reinforced by the observation that global DNA methylation (5MeCyt) is altered in minor salivary glands from pSS patients and that such defect is associated cytokeratin 19 (KRT19) overexpression. An epigenetic deregulation of the KRT19 gene was further tested by treating the human salivary gland (HSG) cell line with the DNA demethylating agent 5-azacytidin, and with the histone acetylase inhibitor trichostatin A. Blocking DNA methylation, but not histone acetylation, with 5-azacytidin was associated with KRT19 overexpression at both transcriptional and protein level. Next, analysis of the CpG genome-wide methylome array in the KTR19 locus from long term cultured SGEC obtained from 8 pSS patients revealed a more reduced DNA methylation level in those patients with defective global DNA methylation. Altogether, our data, therefore, suggest that alteration of DNA methylation in SGEC may contribute to pSS pathophysiology in part by controlling the expression of KRT19.

Comparison of the Diagnostic Value Between Real-Time Reverse Transcription-Polymerase Chain Reaction Assay and Histopathologic Examination in Sentinel Lymph Nodes for Patients With Gastric Carcinoma

OBJECTIVES

Sentinel lymph node (SLN)-based diagnosis in gastric cancers has shown varied sensitivities and false-negative rates in several studies. Application of the reverse transcription-polymerase chain reaction (RT-PCR) in SLN diagnosis has recently been proposed.

METHODS

A total of 155 SLNs from 65 patients with cT1-2, N0 gastric cancer were examined. The histopathologic results were compared with results obtained by real-time RT-PCR for detecting molecular RNA (mRNA) of cytokeratin (CK)19, carcinoembryonic antigen (CEA), and CK20.

RESULTS

The sensitivity and specificity of the multiple marker RT-PCR assay standardized against the results of the postoperative histological examination were 0.778 (95% confidence interval [CI], 0.577-0.914) and 0.781 (95% CI, 0.700-0.850), respectively. In comparison, the sensitivity and specificity of intraoperative diagnosis were 0.819 (95% CI, 0.619-0.937) and 1.000 (95% CI, 0.972-1.000), respectively. The positive predictive value of the multiple-marker RT-PCR assay was 0.355 (95% CI, 0.192-0.546) for predicting non-SLN metastasis, which was lower than that of intraoperative diagnosis (0.813, 95% CI, 0.544-0.960).

CONCLUSIONS

The real-time RT-PCR assay could detect SLN metastasis in gastric cancer. However, the predictive value of the real-time RT-PCR assay was lower than that of precise histopathologic examination and did not outweigh that of our intraoperative SLN diagnosis.

Nucleus pulposus phenotypic markers to determine stem cell differentiation: fact or fiction?

Progress in mesenchymal stem cell (MSC) based therapies for nucleus pulposus (NP) regeneration are hampered by a lack of understanding and consensus of the normal NP cell phenotype. Despite the recent consensus paper on NP markers, there is still a need to further validate proposed markers. This study aimed to determine whether an NP phenotypic profile could be identified within a large population of mature NP samples.qRT-PCR was conducted to assess mRNA expression of 13 genes within human non-degenerate articular chondrocytes (AC) (n=10) and NP cells extracted from patients across a spectrum of histological degeneration grades (n=71). qRT-PCR results were used to select NP marker candidates for protein expression analysis.Differential expression at mRNA between AC and non-degenerate NP cells was only observed for Paired Box Protein 1 (PAX1) and Forkhead box F1 (FOXF1). In contrast no other previously suggested markers displayed differential expression between non-degenerate NP and AC at mRNA level. PAX1 and FOXF1 protein expression was significantly higher in the NP compared to annulus fibrosus (AF), cartilaginous endplate (CEP) and AC. In contrast Laminin-5 (LAM-332), Keratin-19 (KRT-19) and Hypoxia Inducible Factor 1 alpha (HIF1α) showed no differential expression in NP cells compared with AC cells.A marker which exclusively differentiates NP cells from AF and AC cells remains to be identified, raising the question: is the NP a heterogeneous population of cells? Or does the natural biological variation during IVD development, degeneration state and even the life cycle of cells make finding one definitive marker impossible?

Cellular and biological evaluation and diagnostic immunohistochemistry of cytokeratin 15/19 expression in distinguishing cutaneous basal cell carcinoma

Recent studies have investigated the expression of proliferative markers, but little is known about the expression of cytokeratin 15 and 19 in different histological subtypes of basal cell carcinoma (BCC). We conducted cellular, biological, clinicopathological and immunohistochemical analysis on the manifestations of 8 BCC by hematoxylin and eosin stain (H&E) staining and immunohistochemistry and reviewed relevant literature. Microscopically, the tumor cells were multiple remarkable foci of epidermolytic hyperkeratosis with large pleomorphic nuclei and scant cytoplasm together with peripheral palisading and forming solid nests. Furthermore, the most tumors were composed of highly cellular areas with a homogenous population of round, ovoid and spindle cells, hyperchromatic nuclei, high cellular pleomorphism, high mitotic index and various morphologic patterns. Moreover, the tumors displayed an invasive growth, with positive expression of Cytokeratin 19 (CK19) and negative expression of CK15. Our study revealed that the expression of CK19 was associated with progression and invasion in cases with BCC and immunohistochemistry is indispensable in distinguishing this tumor from other types of cutaneous carcinoma. To our best knowledge, it may be a considerable biomarker to assess invasiveness of cutaneous-surface BCC and to guide clinical management of such tumors.

[Detection of cytokeratin18 and cytokeratin19 gene expression in blood and tumor tissue of nasopharyngeal carcinoma patients by RT-PCR]

Abstract

OBJECTIVE

To measure the expression of CK18 and CK19 in the cells from peripheral blood and tumor tissue of the nasopharyngeal carcinoma patients,to test whether CK 18 and CK 19 could be biomarkers of nasopharyngeal carcinoma fordiagnosis.

METHOD

The mRNA was extracted from the blood and carcinoma tissue of nasopharyngeal carcinoma and was reversed transcription to cDNA. The 3 pairs primers were designed for RT-PCR and the fold value was calculated to evaluated expression by ΔCT.

RESULT

There are no statistical differences between the CK18 and CK19 gene expression and the gender, age and metastasis in tumor tissue of 45 nasopharyngeal carcinoma patients (P>0. 05). There are significant differences among 3 pathological stages and 2 genes expressed increase as the grade malignancy (P<0. 05). The detecting of the 2 genes expression from blood cells shows that CK18 and CK19 had a high positive ratio 64% and 75% respectively. Meanwhile this method showed a same detection characteristic in tumor and blood, the positive.rate of CK18 and CK19 genes in metastasis is higher than non-metastasis. The results showed CK18 has a high specificity and CK19 has a high sensitivity for prognosis and all relapsed cases are associated with the expression of CK18 and CK19.

CONCLUSION

CK18 and CK19 may be used as biomarkers of nasopharyngeal carcinoma for diagnosis.

Regulatory T-cells and micrometastasis in lymph nodes of stage I NSCLC

BACKGROUND

Regulatory T-cells (Tregs) have a pivotal role not only in abrogating autoimmune disease, but also in tumor immune escape. The purpose of the present study was to evaluate the clinical significance of the relative expression of forkhead/winged helix transcription factor (FOXP3) and micrometastasis in the regional lymph nodes (RLNs) of patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The RLNs in 131 patients who underwent complete surgical resection for stage I NSCLC were collected at the time of surgery. The relative expression levels of FOXP3 and cytokeratin 19 (CK19) in RLNs were determined by quantitative RT-PCR.

RESULTS

The pathological stage was diagnosed as stage IA in 97 patients (74.0%) and stage IB in 34 patients (26.0%). The relative expression levels of FOXP3 and CK19 in the RLNs were 0.062±0.0083% and 0.025±0.056%, respectively. The relative expression of FOXP3 tended to increase with increasing relative expression of CK19. The five-year overall survival rate of the patients with low expression of FOXP3 was better (90.3%) than that of patients with high expression (79.3%) (p=0.0419). A multivariate analysis using the significant variables (gender, age, histology and FOXP3 expression) showed that the FOXP3 expression in RLNs was a significant independent prognostic factor.

CONCLUSION

The expression of CK19 tended to be positively correlated with the expression of FOXP3. High expression of FOXP3 in RLNs was a significant unfavorable prognostic factor in patients with stage I NSCLC.

An intra-operative RT-LAMP method allows rapid and reliable detection of sentinel lymph node metastasis in breast cancer patients

The rapid determination of metastasis in sentinel lymph nodes (SLNs) of breast cancer patients plays a significant role in the selection of a surgery strategy. Although a previous one-step nucleic acid amplification assay that uses reverse-transcription (RT) loop-mediated isothermal amplification (LAMP) has showed specific advantages over traditional pathological examination, its target marker requires optimisation. In addition to epithelial-specific CK19, the internal control gene PBGD and the breast-specific PIP were included in the new method. After the RT-LAMP primers were designed and verified using a cell line, the performance of our method was evaluated by comparing it with the corresponding result of the Food and Drug Administration approved breast lymph node (BLN) assay and routine pathological examination. One hundred and seventy-four valid SLN samples from 101 patients were collected from five hospitals. The threshold of reaction time for CK19, PIP and PBGD was defined as 16, 20 and 20 min, respectively. Compared with the BLN assay, the concordance rate of our method was 95.4% (166/174). Statistical analysis revealed that the two methods are consistent (kappa = 0.890, P < 0.001). When compared with pathological examination, the performance of our method (sensitivity = 81.3%, specificity = 89.7%, kappa = 0.691, P < 0.001) was similar to that of the BLN assay (sensitivity = 87.5%, specificity = 84.9%, kappa = 0.668, P < 0.001). This result demonstrates the potential usefulness of our method in clinical practice. In conclusion, we preliminarily established an intra-operative diagnostic method that assimilates the merits of previous assays. In contrast with the BLN assay and pathological examination, our method can be completed in 30 min and shows high sensitivity, specificity and consistency, which we consider as promising for clinical application.

Expression of bile duct transcription factor HNF1β predicts early tumor recurrence and is a stage-independent prognostic factor in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) frequently exhibits biliary differentiation, which is typically overlooked. Hepatocyte nuclear factor 1β (HNF1β), a bile duct-specific transcription factor expressed in bile ducts but not in the normal hepatocytes, is also expressed in HCC.

MATERIALS AND METHODS

The expression of HNF1β and the biliary differentiation marker cytokeratin 19 (CK19) were retrospectively evaluated using immunohistochemistry in 159 surgically resected primary HCCs.

RESULTS

A significant correlation was observed between HNF1β protein expression and younger age (p = 0.0293), high serum α-fetoprotein levels (p = 6 × 10(-4)), and high tumor grade (p = 0.0255). However, HNF1β expression exhibited no correlation with tumor stage. Patients with HCCs and HNF1β expression were more likely to exhibit early tumor recurrence (ETR; p = 0.0048) and a lower 5-year survival rate (p = 0.0001). A multivariate analysis indicated HNF1β expression as an independent prognostic factor in HCC (p = 0.0048). A combinatorial analysis revealed additive adverse effects of HNF1β when concomitant with CK19 expression and p53 mutation. Furthermore, HNF1β expression can predict poor prognosis in patients with ETR.

CONCLUSION

Our results indicated that HNF1β expression is a crucial predictor of poor prognosis in HCC and is independent of tumor stage. Moreover, concomitant HNF1β and CK19 expressions exhibited additive adverse effects in HCC, confirming that HCC with biliary differentiation has a poor prognosis.

Carcinoma initiation via RB tumor suppressor inactivation: a versatile approach to epithelial subtype-dependent cancer initiation in diverse tissues

Carcinomas arise in a complex microenvironment consisting of multiple distinct epithelial lineages surrounded by a variety of stromal cell types. Understanding cancer etiologies requires evaluating the relationship among cell types during disease initiation and through progression. Genetically engineered mouse (GEM) models facilitate the prospective examination of early oncogenic events, which is not possible in humans. Since most solid tumors harbor aberrations in the RB network, we developed an inducible GEM approach for the establishment and assessment of carcinoma initiation in a diverse range of epithelial tissues and subtypes upon inactivation of RB-mediated tumor suppression (RB-TS). The system allows independent assessment of epithelial subtypes that express either cytokeratins (K) 18 or 19. By Cre-dependent expression of a protein that dominantly inactivates RB and functionally redundant proteins p107 and p130, neoplasia could be initiated in either K18 or K19 expressing cells of numerous tissues. By design, because only a single pathway aberration was engineered, carcinomas developed stochastically only after long latency. Hence, this system, which allows for directed cell type-specific carcinoma initiation, facilitates further definition of events that can progress neoplasms to aggressive cancers via engineered, carcinogen-induced and/or spontaneous evolution.

Immunohistochemical markers in the diagnosis of papillary thyroid carcinomas: The promising role of combined immunostaining using HBME-1 and CD56

We aimed to evaluate the expression and diagnostic value of five immunohistochemical markers (HBME-1, Galectin-3, CK19, CD56 and p63) in a very large series of unequivocal papillary thyroid carcinoma (PTC) cases, including both the classic (CPTC) and the follicular variant (FVPTC). We performed an immunohistochemical analysis on a tissue micro-array of 204 PTCs (98 CPTCs, 90 FVPTCs, and 16 other variants). HBME-1 was the most sensitive marker, staining 95.9% of CPTCs and 81.1% of FVPTCs. CD56, a marker whose expression is reduced or absent in thyroid carcinoma, revealed a negative, "malignant" profile in 93.9% of CPTCs and 73.3% of FVPTCs. Galectin-3, CK19 and p63 were positive in 64.7%, 45.6% and 6.9% of PTCs, respectively. The immunopanel consisting of HBME-1, CD56 and/or CK19 reached the highest sensitivity (95.6%). The co-expression of 2 or more proteins was observed in 88.2% of PTCs, with HBME-1 and CD56 being the most frequent positive association (79.4%). We report a new panel of antibodies consisting of HBME-1, CK19 and CD56 that was found to be highly sensitive for both CPTC and FVPTC. This panel could be recommended as a supplement to the morphological criteria in the diagnosis of difficult FVPTC cases.

Diagnostic value of mesothelin in pleural fluids: comparison with CYFRA 21-1 and CEA

CYFRA 21-1 and CEA have been applied for the differential diagnosis of malignant pleural mesothelioma (MPM). The soluble mesothelin-related peptide (SMRP) has been proposed as a specific marker for distinguishing MPM from benign diseases and other malignancies in pleural effusions (PEs). In this study, we evaluated the usefulness of SMRP in PEs in the detection of mesotheliomas by comparing it with that of CYFRA 21-1, CEA, and with cytological examination. One hundred and seventy-seven consecutive patients (57 MPM, 64 metastatic tumors, and 56 benign diseases) were evaluated using commercial tests. The performance of the markers was analyzed by standard ROC analysis methods, using the area under a ROC curve (AUC) as a measure of accuracy. CYFRA 21-1 better differentiated malignant from benign effusions. The corresponding area under the receiver operating characteristic curve was 0.87, while it was 0.74 for SMRP and 0.64 for CEA (p < 0.001). Conversely, SMRP differentiated MPM from all other PEs better than both CYFRA 21-1 and CEA (AUC = 0.84, 0.76, and 0.32, respectively, p = 0.003). Low levels of CEA were associated with a MPM diagnosis. The AUC for differentiating MPM from metastases was 0.81 for SMRP, 0.61 for CYFRA 21-1, and 0.20 for CEA (p < 0.001). In cases with negative or suspicious cytology, SMRP and CYFRA 21-1 identified 36/71 and 46/66 malignant PEs (29 and 31 MPM, respectively). Only 1 MPM showed a high CEA concentration. No single marker showed the best performance in any comparison. Results suggest that SMRP could improve CYFRA 21-1 and CEA accuracy in the differential diagnosis of MPM.

Expression of cytokeratin 19, HBME-1 and galectin-3 in neoplastic and nonneoplastic thyroid lesions

In this study, 105 cases of thyroid lesions were evaluated to assess the role of HBME-1, cytokeratin-19 (CK-19), galectin-3 in distinguishing benign from malignant thyroid lesions. Thirty-seven papillary, 10 follicular, 6 medullary, 1 mixed medullary follicular cell carcinoma, 3 poorly differentiated carcinoma, 18 adenomatous nodular hyperplasia, 30 follicular adenoma cases were included in the study. Immunohistochemical staining was performed with HBME-1, CK-19, galectin-3 on cross-sections derived from selected paraffin blocks. Benign and malignant lesions were compared in terms of intensity, percentage and type of staining with CK-19, HBME-1 and galectin-3, and a statistically significant difference (p < 0.05) was found. The percentage and intensity of staining was higher in malignant lesions. Especially, strong and diffuse expressions of CK19, HBME-1 and galectin-3 were observed in papillary carcinomas. Membranous (luminal) staining was seen more frequently in malignant lesions; cytoplasmic staining in benign lesions. It was concluded that these markers could assist in the diagnosis of thyroid lesions with cellular properties suspicious for the diagnosis of papillary carcinoma and without capsule and vessel invasion. They may be used especially in cases where the follicular variant of papillary carcinoma, follicular adenoma and follicular carcinoma are confused with each other and follicular adenoma cannot be differentiated from follicular carcinoma.

Circulating tumor cells and "suspicious objects" evaluated through CellSearch® in metastatic renal cell carcinoma

BACKGROUND

Recent evidence supports the hypothesis that the CellSearch assay, used in the enumeration of circulating tumor cells (CTCs), may underestimate the number of CTCs, especially in tumors, such as renal cell carcinoma, frequently lacking cytokeratin expression. According to the CellSearch guidelines, all objects with no clear cytokeratin staining are defined as "suspicious objects", and are not counted as CTCs. The aim of this study was to investigate the presence of CTCs and "suspicious objects" in 25 patients affected by metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

Twenty-five patients were enrolled in the study, all with a diagnosis of metastatic clear cell RCC. The CellSearch™ system was used to count the CTC in 7.5 mL of whole blood. A further 10 ml blood obtained from each patient was used to isolate CTCs through CELLection™ Dynabeads®. The expression of cytokeratin (CK) 8, 18, 19 and CD44 were evaluated by RT-PCR.

RESULTS

Standard CTCs and suspicious objects were found in 16% and 60% of the patients, respectively. CK-8/18/19 transcripts were found in 15% and CD44 in 68% of the 19 patients with evidence of classical CTC or "suspicious objects" as assessed by Cellsearch.

CONCLUSION

The low number of CTCs detected through CellSearch in renal cell carcinoma may be due to the presence of a CTC population with atypical characteristics and a peculiar gene expression profile, characterized by lack of cytokeratin expression and gain of CD44.

Perinodular CK19 loss in hepatocarcinogenesis

Cirrhotic nodules containing hepatocytes are surrounded by perinodular stroma, that consists of an expanded fibrous matrix and epithelial cells with ductular phenotype, the "ductular-reaction". Stromal invasion is a key histopathologic feature used to differentiate premalignant dysplastic nodules from malignant hepatocellular carcinoma (HCC). K19 immunoreactivity in the stromal compartment in cirrhotic explants was examined. Quantitative differences were manifested in three distinct histologically identifiable patterns: "complex" around cirrhotic nodules, "attenuated" around dysplastic nodules, and "absent" around HCC. These findings suggest marked alterations in cellular identity as an underlying mechanism for the reproducible extralesional K19 pattern that parallels progressive stages of intranodular hepatocarcinogenesis. Paracrine signalling is proposed as a link that emphasizes the importance of the epithelial-stromal compartment in malignant progression of HCC in cirrhosis.

The diagnostic accuracy of the immunocytochemical markers in the pre-operative evaluation of follicular thyroid lesions

Aim of the study was to consider the diagnostic accuracy of galectine-3 (GAL3) in the pre-operative cytological evaluation of follicular lesions.

MATERIALS AND METHODS

We retrospectively evaluated 100 patients suffering from thyroid nodular disease submitted to thyroidectomy from 2006 to 2007 in our Institution. Before surgery all patients underwent fine needle aspiration biopsy. The immunocytochemical analysis was performed on fine needle aspiration specimens using species-specific monoclonal antibodies and a biotin-free detection system. Based on preoperative cytological reports, 40 patients had pre-operative malignant results, and 60 patients (46 females and 14 males) showed follicular lesions. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of GAL3 was evaluated.

STATISTICAL ANALYSIS

Chi-square test was used to compare frequencies of GAL3 expression between the different hystopathological groups.

RESULTS

GAL3 proved to have 55% sensitivity, 100% specificity, 70% negative predictive value, and 78% diagnostic accuracy. The GAL3 expression in neoplastic and benign lesions was significantly different (GAL3+ in 16 out of 29 neoplastic lesions, GAL3+ 0 out of 31 benign lesions, p<0.01). Even comparing the GAL3 positivity between the follicular adenomas (0 GAL3+ out of 20) and the group of follicular carcinomas (5 GAL3+ out of 6), we found a statistically significant difference (p<0.01).

CONCLUSIONS

Based on the data from our experience, the patients with a cytological diagnosis of GAL3 positive follicular neoformation should be referred for surgery without any further immunocytological testing.

Universal markers of thyroid malignancies: galectin-3, HBME-1, and cytokeratin-19

Difficulties in diagnosis of thyroid lesions, even with histologic analysis, are well known. This study has been carried on to evaluate the role of immunohistochemical markers including galectin-3, Hector Battifora mesothelial cell-1 (HBME-1), and cytokeratin-19 in the diagnosis and differential diagnosis of benign and malignant thyroid lesions. The expressions of galectin-3, HBME-1, and cytokeratin-19 were tested in formalin-fixed, paraffin-embedded tissues from 458 surgically resected thyroid lesions including non-neoplastic and neoplastic lesions. Immunostaining with standard avidin-biotin complex technique was performed by using monoclonal antibodies. In malignant neoplastic thyroid lesions, galectin-3, HBME-1, and cytokeratin-19 were diffusely expressed in general. Diffuse expression rates of these three markers were 72.3% (47/65), 70.7% (46/65), and 76.9% (50/65), respectively. The use of galectin-3, HBME-1, and cytokeratin-19 may provide significant contributions in the differential diagnosis of malignant thyroid tumors. Although focal galectin-3, HBME-1, and cytokeratin-19 expression may be encountered in benign lesions, diffuse positive reactions for these three markers are characteristic of malignant lesions. It has concluded that cytokeratin-19 alone and its combinations with other markers were more sensitive in accurate diagnosis of papillary carcinoma than the other combinations; meanwhile, there were similar results for follicular carcinomas with HBME-1 alone and its combinations.

Clinical relevance of thymidine kinase for the diagnosis, therapy monitoring and prognosis of non-operable lung cancer

BACKGROUND

Whether thymidine kinase (TK) is considered a new diagnostic biomarker in lung cancer depends on it being superior to or adding further information to already established tumor markers. Here, we investigated its relevance in diagnosis, therapy monitoring and prognosis of patients with diverse forms of lung cancer.

PATIENTS AND METHODS

Pretherapeutic TK concentrations were analyzed by radioimmunoassay in serum of 181 patients with advanced lung cancer (53 small cell lung cancer (SCLC), 128 non-small cell lung cancer (NSCLC)), 40 with benign lung diseases, 44 with benign non-lung-related diseases and 29 healthy controls. Diagnostic power of TK was compared with that of established lung cancer markers carcinoembryonic antigen (CEA), cytokeratin 19-fragments (CYFRA 21-1), neuron-specific enolase (NSE) and progastrin-releasing peptide (ProGRP). Furthermore, TK courses of 29 NSCLC patients during cytotoxic chemotherapy were recorded and prognostic relevance of pretherapeutic TK levels was tested in 128 NSCLC patients.

RESULTS

While healthy controls had low TK serum levels (median 2.5 U/l, 95th percentile 8.8 U/l), they were significantly higher in patients with lung cancer (median 4.2 U/l, p=0.014) and also in patients with benign lung diseases (median 5.7 U/l; p=0.002). Patients with lung cancer and benign lung diseases could not be separated by TK values. No noticeable difference of TK concentrations was further found in NSCLC (median 4.3 U/l) as compared with SCLC patients (median 3.7 U/l) neither in adeno cell carcinomas (median 5.4 U/l) and squamous cell carcinomas (median 3.0 U/l). In NSCLC, the best diagnostic capacity versus benign lung diseases was found for CYFRA 21-1 (AUC 88.2%), NSE (AUC 86.4%), and CEA (AUC 82.9%), while TK reached only an AUC of 45.7%. The best diagnostic profile in SCLC versus benign lung diseases was observed for NSE (AUC 93.9%) and ProGRP (AUC 85.4%), while TK did not have any diagnostic power (AUC 46.6%). Concerning therapy monitoring, TK was unable to discriminate between the various response groups, neither pretherapeutically, nor before therapy cycles 2 and 3. However, pretherapeutic TK levels showed high prognostic value for overall survival in NSCLC patients: While median survival in patients with TK levels >or=20 U/l was only 3.1 months, it was 9.0 months in patients with TK levels <20 U/l. In multivariate analyses, TK remained an independent prognostic marker, along with the clinical variables stage and performance score.

CONCLUSION

Although the performance of serum TK for diagnosis and therapy monitoring of advanced lung cancer was poor, it has a promising prognostic relevance which will have to be further validated.

Centre-independent detection of non-small cell lung cancer (NSCLC) by means of classification with receiver operating characteristic (ROC)-based data transformation

The diagnosis of non-small cell lung cancer (NSCLC) by using tumour markers needs to be improved and standardised in order to compare marker profiles from different centres. A centre-independent tool based on receiver operating characteristics (ROC) curves instead of cut-off-based approaches for NSCLC diagnosis was established. Carcinoembryonic antigen (CEA) and cytokeratin-19 fragments (CYFRA 21-1) were measured in 326 NSCLC patients and 160 patients with benign lung diseases (Heidelberg, HD) and compared to 158 NSCLC patients and 128 controls from an occupational medicine high-risk cohort (Giessen, GI). The cohorts differed in tumour-stages, marker cut-offs and therefore in sensitivity for NSCLC detection. Sensitivity for CYFRA 21-1 (most sensitive marker) was 65% GI, 35% HD, for CEA: 43% GI and 35% HD. Marker-combination increased sensitivity to 53% HD resp. 73% GI, accompanied by decreasing specificity. A transfer of the cut-off-based classification methods from HD to GI and vice versa led to false classifications. Sensitivity and specificity do not change using classification methods on transformed data such as the described decision guarantee. CEA/CYFRA-combination allows a classification method transferable despite structural differences of the cohorts. Only 0.8% of the datasets showed discordance in classification. The diagnosis of NSCLC based on ROC curves eliminate centre-specific differences. Classification methods lead to an improvement in NSCLC diagnosis.

[Comparative study for detecting micrometastases of lymph nodes in patients with lung cancer]

OBJECTIVE

To set up a new method to detect occult micrometastases of lymph nodes in patients with no-small-cell lung cancer (NSCLC).

METHODS

We had detected 195 lymph node samples taken from 25 patients with NSCLC during the operations. Each lymph node sample was divided into two same parts in size. The one half part of lymph node should be examined by conventional histopathologic examination and immunohistochemical (IHC) staining. All the remaining lymph node samples of each patient should be mixed together for the reverse transcriptase-polymerase chain reaction (RT-PCR) if they located in the same region. As long as the presence of metastatic tumor in one lymph node was found by H&E staining, all other lymph node samples in the same region should not be detected by IHC staining or RT-PCR techniques.

RESULTS

Frozen tissue sections of 135 lymph nodes that were staged as free of metastases by conventional histopathologic examination were screened by IHC staining. 31 lymph nodes showed single cell or cells clusters. Of 39 groups mixed regional lymph nodes which were diagnosed to be devoid of metastases by conventional histopathologic examination, 11 groups were found to have positive reactions to cytokeratin 19-mRNA by RT-PCR. There was a correlation between IHC staining and RT-PCR for detection of nodal micrometastases of NSCLC (U = 7.682, P = 0.0001).

CONCLUSION

IHC staining analysis can facilitate the detection of occult micrometastases in lymph nodes of NSCLC, and its assessment of nodal micrometastases can provide a refinement of TNM stage for partial patients with stage I to II. RT-PCR has the same value as IHC staining in detection of lymph nodal micrometastases. RT-PCR technique can reduce expense of the detecting micrometastases in lymph nodes.

Expression of stem cell markers CK-19 and PDX-1 mRNA in pancreatic islet samples of different purity from rats

BACKGROUND

Islet stem cells are more or less retained in the procedure of islet isolation and purification, and are transplanted together with islet grafts. Keratoprotein (CK-19) and pancreatic duodenal hox gene 1 (PDX-1) are markers of stem cells. This study was undertaken to examine the expression of these markers in pancreatic islet samples of different purity from rats.

METHODS

A total of 30 male Sprague-Dawley rats were randomly assigned to 3 groups to undergo perfusion with V-type collagenase via the pancreatic duct, then the pancreas was excised, diced, shaken, digested and centrifuged to obtain islet sediments. The sediment from group A was not purified, while that from group B was purified with 25% Ficoll-400 and that from group C with 25% and 11% Ficoll-400. RNA was extracted from the different islet samples for reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of the pancreatic stem cell markers CK-19 and PDX-1 was assessed.

RESULTS

The purity of islets in samples was (43.6+/-6.29)% in group A; (65.3+/-4.40)% in group B; and (77.6+/-6.36)% in group C (P<0.05). The expression of CK-19 and PDX-1 mRNA was significantly higher in group A than in groups B and C, but group C showed the lowest level of expression.

CONCLUSION

The expression of CK-19 and PDX-1 mRNA in islet samples of different purity suggests the presence of stem cells in all islet samples.

Characterization of cytokeratin 19-positive hepatocyte foci in the regenerating rat liver after 2-AAF/CCl4 injury

Partial hepatectomy or carbon tetrachloride (CCl4) injury, following treatment of rats with 2-acetylaminofluorene (2-AAF) to inhibit proliferation of hepatocytes, induces proliferation of oval cells and possibly their differentiation into nodular foci of hepatocytes when higher doses of 2-AAF are used. Unfortunately, immunohistochemistry in previous studies failed to show oval cell markers in these foci, and thereby to demonstrate the precursor-product relationship between oval cells and hepatocytes. Immunohistochemistry on livers of rats treated with high dose 2-AAF/CCl4 was used. We found 7.6% of the hepatocyte foci were positive for an oval cell marker cytokeratin 19 (CK-19). These foci were positive for alpha-fetoprotein, less positive for carbamoylphosphate synthetase 1, and more positive for laminin in the basement membrane lining. Rarely present transitional foci had weaker expression of CK-19 and discontinuous laminin. Focal hepatocyte differentiation of oval cells was characterized by cell hypertrophy, membranous CK-19, and positive hepatocyte nuclear factor 4 (HNF-4). HNF-4+ small oval cells surrounding CK-19+ foci were frequently seen, suggesting that a paracrine mechanism(s) may be responsible for the enlargement of CK-19+ foci. In conclusions, oval cells appear to differentiate to CK-19+ foci and then to CK-19- foci in the high dose 2-AAF/CCl4 model.

Expression of the novel protein PTPIP51 in rat liver: an immunohistochemical study

Expression of the novel protein tyrosine phosphatase interacting protein 51 (PTPIP51) was investigated on mRNA and protein level in the liver of adult Wistar rats. The presence of PTPIP51 mRNA was detected by Northern blotting. Immunostaining showed expression of PTPIP51 protein in distinct non-parenchymal cells. These cells were identified as Kupffer cells, stellate cells and natural killer cells by detection of cell-specific antigens. Whereas most endothelial cells lining large vessels reacted positive to the PTPIP51 antibody, sinusoidal endothelium showed no detectable amount of PTPIP51. Furthermore, PTPIP51 was also found to be expressed in cells forming the biliary tree. An additional subcellular analysis of the non-parenchymal cells by means of electron microscopy showed the presence of PTPIP51 protein in the cytoplasm and in the nuclei of non-parenchymal cells. Most of the hepatocytes did not show any immuno-detectable amount of PTPIP51, yet, some revealed PTPIP51 protein either in the cytoplasm or in the nucleus.

Distinctive molecular composition of human gingival interdental papilla

BACKGROUND

Gingiva is composed of attached and marginal (free) gingiva and interdental papilla. Increasing esthetic demands in dentistry have created a need to restore all parts of the gingiva. However, the interdental papilla has limited regeneration potential compared to other parts of the gingiva. It also is more susceptible to gingival overgrowth, suggesting that it has distinct cellular and molecular properties from other parts of the gingiva. Very little is known about the possible differences in the molecular composition of different parts of the gingiva.

METHODS

We compared the expression of a set of key molecules in interdental papilla and marginal gingiva from seven healthy subjects by immunohistochemical staining.

RESULTS

In the interdental papilla, immunoreactivity for integrin alphavbeta6 and cytokeratin 19 in the oral epithelium was significantly higher than in marginal gingiva. Expression of type I procollagen, extra domain A (EDA) and extra domain B (EDB) fibronectin isoforms, tenascin-C, transforming growth factor-beta (TGF-beta), connective tissue growth factor (CTGF), and the signaling molecule son-of-sevenless (SOS)-1 also were increased in the interdental papilla. The expression of small leucine-rich proteoglycans decorin, biglycan, fibromodulin, and lumican in the interdental papilla was partially different from the marginal gingiva.

CONCLUSIONS

Molecular composition of the interdental papilla is distinct from marginal gingiva. Increased expression of molecules normally induced in wound healing (alphavbeta6 integrin, fibronectin-EDB and -EDA, tenascin-C, type I procollagen, TGF-beta, CTGF, and SOS-1) suggests that the cells in the interdental papilla are in an activated state and/or inherently display a specific phenotype resembling wound healing.

Quantitative detection of circulating epithelial cells by Q-RT-PCR

INTRODUCTION

It has been shown that the quantity of circulating tumor cells (CTCs) in breast cancer patients is an independent predictor of survival and treatment response. Real time quantitative reverse transcriptase PCR (Q-RT-PCR) is a sensitive technique for detection of CTCs. Our aim was to investigate whether the technique can be used also to quantitate these CTCs.

METHODS

We tested cytokeratin 19 (CK19), maspin, mammaglobin, GAPDH and RPL19 genes for their level of expression and linearity of amplification in serial dilutions of RNA extracted from the MDA-MB-231, UACC-812, T47D and HS578T breast cancer cell lines. To simulate CTCs, serial dilutions of cultured T47D and HS578T cells were added to peripheral blood from healthy volunteers. The samples were subjected to enrichment, RNA extraction and Q-RT-PCR.

RESULTS

CK19 was reliably expressed in all four cell lines with a linear relationship between the quantity of added cells and the amount of CK19 RNA. The lower limit of reliable detection was 5 cells per sample, which corresponds to a concentration of 0.7 cell/ml in 7.5 ml of blood or would translate to a lower CTC concentration in a larger volume of blood.

CONCLUSION

This technique may prove useful for high throughput comparative quantification of CTCs in individual patients during treatment and subsequent follow up for research and clinical management purposes.

In vitro differentiation of hepatic progenitor cells from mouse embryonic stem cells induced by sodium butyrate

Recently it was shown that embryonic stem (ES) cells could differentiate into hepatocytes both in vitro and in vivo, however, prospective hepatic progenitor cells have not yet been isolated and characterized from ES cells. Here we presented a novel 4-step procedure for the differentiation of mouse ES cells into hepatic progenitor cells and then hepatocytes. The differentiated hepatocytes were identified by morphological, biochemical, and functional analyses. The hepatic progenitor cells were isolated from the cultures after the withdrawal of sodium butyrate, which was characterized by scant cytoplasm, ovoid nuclei, the ability of rapid proliferation, expression of a series of hepatic progenitor cell markers, and the potential of differentiation into hepatocytes and bile duct-like cells under the proper conditions that favor hepatocyte and bile epithelial differentiation. The differentiation of hepatocytes from hepatic progenitor cells was characterized by a number of hepatic cell markers including albumin secretion, upregulated transcription of glucose-6-phosphatase and tyrosine aminotransferase, and functional phenotypes such as glycogen storage. The results from our experiments demonstrated that ES cells could differentiate into a novel bipotential hepatic progenitor cell and mature into hepatocytes with typical morphological, phenotypic and functional characteristics, which provides an useful model for the studies of key events during early liver development and a potential source of transplantable cells for cell-replacement therapies.

Maturation of in vitro-generated human islets after transplantation in nude mice

The long-term function of human pancreatic islet grafts may depend on the neogenesis of beta cells from epithelial precursors within the grafted tissue. We have developed an in vitro model for human islet neogenesis. In this study, we have investigated the morphological signs of maturation in cultivated human islet buds (CHIBs) before and after transplantation. Clusterin is a molecule associated with beta-cell differentiation in rodents. In adult human islets, clusterin expression was located only in alpha- and PP-cells, but in CHIBs and human fetal islets, it was distributed in all four types of endocrine cells. Some immature endocrine cells in the CHIBs co-expressed insulin and glucagon. After transplantation, CHIBs became mature with one type of hormone per endocrine cell, and clusterin expression became restricted in alpha-cells. Cells co-expressing endocrine markers and cytokeratin 19, as a sign of ductal to endocrine cell transition, were frequently detected in both fresh islets and CHIBs after transplantation. We conclude that clusterin may be involved in the development of islets, and the in vitro-derived islets become mature after transplantation into nude mice. Ductal cell differentiation into endocrine cells may be an important factor in sustaining the long-term function of islet transplants.

[Cytokeratin-19 in diagnosis of bone marrow metastases in patients with breast cancer - clinical results]

A lot of information about the structure and the clinical significance of citokeratins in diagnosis of malignances has been found in literature during last years. Some questions about their significance in tumor genesis and in prognosis when tumor cells are found far from the primary tumor are cleared. Our aim was to investigate bone marrow samples from 79 women with breast cancer and to detect the presence or the absence of citokeratin positive tumor cells and their significance for the prognosis of the disease. We found that citokeratin 19 provides a good estimation for presence of tumor cells in bone marrow of patients with breast cancer. Citokeratin positive samples are a marker for worse prognosis in patients with breast cancer than citokeratin 19 negative ones.

Prospero-related homeobox 1 (Prox1) is a stable hepatocyte marker during liver development, injury and regeneration, and is absent from "oval cells"

The aim of this study was to analyse the changes of Prospero-related homeobox 1 (Prox1) gene expression in rat liver under different experimental conditions of liver injury, regeneration and acute phase reaction, and to correlate it with that of markers for hepatoblasts, hepatocytes, cholangiocytes and oval cells. Gene expression was studied at RNA level by RT-PCR, and at protein level by immunohistochemistry. At embryonal stage of rat liver development (embryonal days (ED) 14-16) hepatoblasts were found to be Prox1(+)/Cytokeratin (CK) 19(+) and alpha-fetoprotein (AFP)(+), at this stage Prox1(-)/CK19(+)/AFP(-) small cells (early cholangiocytes?) were identified. In fetal liver (ED 18-22) hepatoblasts were Prox1(+)/CK19(-)/AFP(+). CK7(+) cholangiocytes were detected at this stage, and they were Prox1(-)/AFP(-). In the adult liver hepatocytes were Prox1(+)/CK19(-)/CK7(-)/AFP(-), cholangiocytes were CK19(+) and/or CK7(+) and AFP(-)/Prox1(-). In models of liver damage and regeneration Prox1 remained a stable marker of hepatocytes. After 2-acetyl-aminofluorene treatment with partial hepatectomy (AAF/PH) the amount of Prox1 specific transcripts was low in the liver, when CK19 and AFP gene expression was high, and at no time point AFP(+)/CK19(+ )"oval cells" were found to be Prox1(+). However, a few Prox1(+)/CK19(+) and a few Prox1(+)/CK7(+ )cells were identified in the liver of AAF/PH-animals, which may represent precursors of hepatocytes, or a precancerous state.

[Mechanism of signal transduction of differentiation of mesenchymal stem cells into cytokeratin-expressing epidermoid cells]

OBJECTIVE

To investigate the role of the signal routes P38, ERK, and Rho in the differentiation of bone marrow mesenchymal stem cells (MSCs) into epidermoid cells.

METHODS

(1) MSCs were separated from the bone marrow of Wistar rats by Ficoll-Pague lymphocyte separating medium and proliferated in culture medium. Then the MSCs were immunocytochemically stained to detect the expression of surface antigens. (2) The MSCs were randomly divided into 3 groups: control group; pure induction induced group, cultured with epithelial growth factor (EGF) added into the culture fluid, and Rho inhibition group, cultured with EGF and HA1077, a ROK inhibitor, added into the culture fluid. One, 3, 5, and 7 days later FC was used to detect the levels of phosphorylated P38 and ERK. (3) MSCs were randomly divided into 4 groups: control group, cultured with low-sugar DMEM complete culture fluid; pure induction group, cultured with supernatant of rat fibroblasts and EGF added into the culture fluid, p38 blocking group, with SB203580, inhibitor of P38 added into the culture fluid; and ERK blocking group, with PD98059, inhibitor of ERK added into the culture fluid. Seven days later, SP method was used to detect the expression of CK5/8 and CK19 induced by MSCs. (4) MSCs were randomly divided into 4 groups: control group; pure induction group, with supernatant of rat fibroblasts and EGF added into the culture fluid; and RHO blocking group, with HA1007 added into the culture fluid. Seven days later, FC was used to detect the expression of CK5/8 and CK19.

RESULTS

(1) Both FC and immunocytochemistry showed that the MSCs were uniformly positive in CD29 and CD44, but did not express CD34 and CD45. (2) The phosphorylated P38 rate remained 0.01% in the control group. The phosphorylated P38 rate was 0.04%, significantly higher than that of the control group (0.01%, P < 0.05) at day 5, and then lowered to 0.01% at day 5 in the pure induction group; and became 6.17%, 4.13%, 3.97%, and 0.41% respectively at day 1, 3, 5, and 7, all significantly higher than those of the control group (all P < 0.05), in the Rho inhibition group. The phosphorylated ERK level was 4.23% in the control group; became 0.39% and 0.40% at day 3 and day 5 (both P < 0.05), and then returned to 5.10% at day 7 in the pure induction group; and was not significantly changed at days 1, 3, and 5, and then became 0.41%, significantly lower than that of the control group (P < 0.05), in the Rho blocking group, (3) The control group was CK5/8 and CK19 negative. The CK5/8 and CK19 rates at day 7 of the pure induction group were 3.01% and 6.47% respectively, both significantly higher than those of the p38 inhibition group (1.43% and 5.41% respectively, both P < 0.05). The CK5/8 and CK19 expression rates of the ERK inhibition group were 5.54% and 7.56% respectively, both significantly higher than those of the pure induction group (both P < 0.05), (4) The CK5/8 and CK19 expression rates of the HA1077 group were 21.65% and 39.41% pure, both significantly higher than those of the pure induction group (1.81% and 10.19% respectively, both P < 0.05).

CONCLUSION

p38 route may play an active role in the differentiation of MSCs into epidermoid cells. Blocking of the upstream signal Rho may enhance the activation of p38 route and then promote the differentiation of MSCs into epidermoid cells.

[Detection of cytokeratin 19 and thyroperoxidase expressions in the diagnosis of thyroid diseases]

OBJECTIVE

To investigate the value of detecting cytokeratin 19(CK19) and thyroperoxidase (TPO) expression in the diagnosis of thyroid diseases including thyroid carcinoma, multinodular goiter, adenoma and Hashimoto thyroiditis.

METHODS

SP immunohistochemistry was used to detect the expressions of CK19 and TPO in paraffin-embedded thyroid tissue specimens obtained from 62 patients with thyroid carcinoma (30 with papillary carcinomas, 22 with follicular variant of papillary carcinomas, and 10 with follicular carcinomas) and 44 with benign thyroid diseases (including 22 with multinodular goiters, 14 with adenoma, and 8 with Hashimoto thyroiditis).

RESULTS

CK19 expression was detected in 96.8% of the thyroid carcinomas and in 4.5% of benign thyroid diseases, demonstrating a significant difference in CK19 expression between the two thyroid diseases (P<0.01). TPO expression was found in 100% of benign thyroid disease and in 3.2% of thyroid carcinoma, showing also a significant difference between them (P<0.01).

CONCLUSION

CK19 and TPO can be important molecular markers for diagnosing thyroid carcinoma.

[Expression and clinical significance of cytokeratin 19 in bone marrow of patients with breast cancer]

BACKGROUND & OBJECTIVE

Breast cancer may undergo metastasis in early phase. Distant metastasis, especially bone metastasis, may influence prognosis of breast cancer patients. Bone marrow micrometastasis (BMM) is difficult to detect with routine methods. This study was designed to evaluate expression and clinical significance of cytokeratin 19 (CK19) in bone marrow of patients with breast cancer.

METHODS

Expression of CK19 mRNA in bone marrows of 65 breast cancer patients, 15 benign breast disease patients, and 8 healthy volunteers was detected by reverse transcription-polymerase chain reaction (RT-PCR). Correlation of CK19 mRNA expression to clinicopathologic features of the 65 breast cancer patients was analyzed.

RESULTS

Positive rate of CK19 mRNA was 33.8% in the 65 breast cancer patients, and 0 in both benign breast disease patients and healthy volunteers. Expression of CK19 mRNA was positively correlated with tumor size and clinical stage (P < 0.05), but was not related to age and lymph node status (P > 0.05). In addition, positive rate of CK19 mRNA was positively correlated with carcinoembryonic antigen (CEA) in peripheral blood (r=0.372, P=0.002).

CONCLUSIONS

CK19 mRNA may be used as a molecular marker to detect bone marrow micrometastasis in patients with breast cancer. The detection may help to select proper therapy and predict prognosis of breast cancer patients.