Cytokeratins in the Histological Diagnosis of Malignant Tumors

Circulating Biomarkers in the Management of Breast Cancer

Circulating biomarkers have become a promising modality in the management of many cancers. Similarly, in breast cancer, circulatory biomarkers are useful, non-invasive methods in the diagnosis, prognostication, and evaluation of response to treatment. Invasive surgical biopsies can be potentially replaced by “liquid biopsy,” which involves analysing circulatory biomarkers that may reveal features of primary and metastatic disease. Therefore, providing an insight into the cancer biology can be utilised to monitor treatment response, treatment-induced adaptation and tumour and disease progression through non-invasive means. The objective of this review is to provide an overview of the current status of the circulating biomarkers highlighting their promising impact on the management of patients with breast cancer.

The Clinical Value of Cyfra 21-1 Estimation for Lung Cancer Patients

Cytokeratin-19, one of the cytoskeletal proteins, is expressed both in bronchial epithelium and in lung cancer cells. The aim of our study was to establish the value of serum cytokeratin-19 soluble fragment (Cyfra 21-1) measurement in lung cancer patients. Cyfra 21-1 levels were estimated in 35 patients (pts) with benign lung diseases and in 116 lung cancer patients: 55 pts with squamous cell lung cancer, 38 pts with small cell lung cancer and 23 pts with adenocarcinoma. The cutoff level was set at 4 ng/ml with a specificity of 94% and a sensitivity of 40%. Elevated Cyfra 21-1 values were found in 44% of squamous cell lung cancer, 39% of adenocarcinoma and 34% of small cell lung cancer pts (the difference was not significant). In squamous cell lung cancer and in adenocarcinoma elevated Cyfra 21-1 values were observed more often in patients with advanced disease than in patients with limited disease. There was no significant correlation between the initial Cyfra 21-1 level and the response to chemotherapy. Cyfra 21-1 was hot a prognostic indicator, although in operable squamous cell lung cancer the proportion of survivors in the second year of observation was higher among the patients with normal preoperative Cyfra 21-1 levels.

A Catalogue of Altered Salivary Proteins Secondary to Invasive Ductal Carcinoma: A Novel In Vivo Paradigm to Assess Breast Cancer Progression

The objective of this manuscript is to introduce a catalogue of salivary proteins that are altered secondary to carcinoma of the breast. The catalogue of salivary proteins is a compilation of twenty years of research by the authors and consists of 233 high and low abundant proteins which have been identified by LC-MS/MS mass spectrometry, 2D-gel analysis and by enzyme-linked immunosorbent assay. The body of research suggests that saliva is a fluid suffused with solubilized by-products of oncogenic expression and that these proteins may be useful in the study of breast cancer progress, treatment efficacy and the tailoring of individualized patient care.

Immunohistochemical Expression of Cyclin D1, Cytokeratin 20, and Uroplakin III in Proliferative Urinary Bladder Lesions Induced by o-Nitroanisole in Fischer 344/N Rats

o-Nitroanisole is an intermediate in the manufacture of azo dyes. In a National Toxicology Program stop-exposure study,o-nitroanisole induced hyperplasia, papillomas, and papillary carcinomas in the urinary bladder of Fischer 344/N rats.o-Nitroanisole was investigated since occupational or environmental exposure to aniline and azo dyes is a risk factor for urinary bladder cancer in humans. The current study describes the morphology of urinary bladder neoplasms seen in rats with respect to those observed in humans. This study also evaluated immunohistochemical expression of the cell cycle-related proteins cyclin D1 and p53 and the differentiation markers cytokeratin 20 and uroplakin III in hyperplastic (n= 11) and neoplastic (n= 6 papillomas,n= 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n= 6) urinary bladders from untreated rats. The tumors observed were more similar to the papillary type rather than the muscle-invasive type of urinary bladder cancer in humans. The preneoplastic and neoplastic lesions observed suggest progression from hyperplasia to papilloma to papillary carcinoma. With neoplastic progression (hyperplasia to papilloma to carcinoma), cyclin D1 immunoreactivity progressively increased in intensity, percentage of cells staining, and distribution. Overexpression of p53 was not found. Cytokeratin 20 staining decreased in superficial cells, while uroplakin III staining increased in intermediate and basal cells with progression from hyperplasia to carcinoma. The results are consistent with increased cell cycle dysregulation or proliferation (cyclin D1), decreased differentiation (cytokeratin 20), and abnormal differentiation (uroplakin III) as lesions progress toward malignancy.

Scalp metastasis from esophageal adenocarcinoma: comparative histopathology dictates surgical approach

Cutaneous metastasis of esophageal cancer, in particular esophageal adenocarcinoma, is rare and metastasis to the scalp is extremely rare. We describe such a case that was originally diagnosed as an adnexal carcinoma. A 77-year-old male with a history of esophageal adenocarcinoma status after esophagectomy at our institution 4.5 years prior, presented to our plastic surgery clinic with a 2-month history of 2 temporoparietal scalp lesions. He was referred to our clinic by a community dermatologist who had performed a shave biopsy of the lesions. The clinical diagnosis was adnexal cyst. The history of esophageal carcinoma was not provided to the pathologist. The dermatopathology report came back as malignant adnexal neoplasm and considerations included apocrine carcinoma. We reexamined the pathologist's slides from the outside facility, comparing them to the histopathology from his esophagectomy. Histopathologic changes were identical. Thus, our surgical and postoperative approach changed significantly. Clinical suspicion should be high for cutaneous metastases in patients with a history of solid organ cancers. It is important for clinicians to illicit a history of malignancy. A biopsy should be performed on any suspicious lesions, and clinical data along with histopathology of the prior cancer resection(s) should be provided to the pathologist for comparison. Diagnosis of the suspicious lesion should be made before definitive excision, as this may change the approach, with the potential for postoperative chemotherapy and radiation. The definitive operative approach consists of surgical debulking with the evidence of negative margins. On the scalp, we feel that 5-mm margins are appropriate to obtain clear margins. One should appreciate the subdermal extent of metastases and adjust the margins accordingly. We recommend excising the galea with the skin as an en bloc resection. This will both assure clear deep margins of resection and assist in a tension-free closure of the scalp.

Cutaneous metastases from internal malignancies: a clinicopathologic and immunohistochemical review

Skin metastases occur in 0.6%-10.4% of all patients with cancer and represent 2% of all skin tumors. Skin metastases from visceral malignancies are important for dermatologists and dermatopathologists because of their variable clinical appearance and presentation, frequent delay and failure in their diagnosis, relative proportion of different internal malignancies metastasizing to the skin, and impact on morbidity, prognosis, and treatment. Another factor to take into account is that cutaneous metastasis may be the first sign of clinically silent visceral cancer. The relative frequencies of metastatic skin disease tend to correlate with the frequency of the different types of primary cancer in each sex. Thus, women with skin metastases have the following distribution in decreasing order of frequency of primary malignancies: breast, ovary, oral cavity, lung, and large intestine. In men, the distribution is as follows: lung, large intestine, oral cavity, kidney, breast, esophagus, pancreas, stomach, and liver. A wide morphologic spectrum of clinical appearances has been described in cutaneous metastases. This variable clinical morphology included nodules, papules, plaques, tumors, and ulcers. From a histopathologic point of view, there are 4 main morphologic patterns of cutaneous metastases involving the dermis, namely, nodular, infiltrative, diffuse, and intravascular. Generally, cutaneous metastases herald a poor prognosis. The average survival time of patients with skin metastases is a few months. In this article, we review the clinicopathologic and immunohistochemical characteristics of cutaneous metastases from internal malignancies, classify the most common cutaneous metastases, and identify studies that may assist in diagnosing the origin of a cutaneous metastasis.

Evaluation of Barrett's esophagus with CK7, CK20, p53, Ki67, and COX2 expressions using chromoendoscopical examination

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease and can be diagnosed when there is an endoscopically irregular Z-line and intestinal metaplasia (IM) in a biopsy obtained lower esophagus. It is still not clear whether IM in the gastric cardia or columnar mucosa without IM in the lower esophagus have any significance as BE, which is considered as preneoplastic. The aim of the study was to determine the immunohistochemical features of BE and columnar mucosa in the distal esophagus and also to evaluate the value of chromoendoscopy in the diagnosis of BE in a prospective manner. A total of 12 chromoendoscopic biopsies (six from normal-looking unstained esophagus and six from esophageal mucosa stained with methyl blue suspicious of BE) were taken from 111 cases who underwent endoscopy because of a variety of upper gastrointestinal symptoms. Immunohistochemical analysis was performed using CK7, CK20, p53, Ki67, and cyclooxygenase 2 (COX2). Of the 111 cases, 19 cases with carcinoma (nine adeno, six squamous, four undifferentiated carcinomas) and 17 cases with normal squamous epithelium were excluded, while 75 cases showing columnar epithelium, including 46 (61.3%) with IM and 29 (38,7%) without IM, were further evaluated immunohistochemically. CK7 was observed in surface, crypt, and glandular epithelium, whereas CK20 was expressed in surface and superficial crypt epithelium. No significant difference was observed between the Barrett and non-Barrett type of CK7/20 staining pattern (P > 0,05). Expression of p53 did not show any difference between BE and columnar mucosa without IM, whereas COX2 expression was significantly increased in BE (P < 0.05) in comparison with columnar mucosa without IM. Ki67 expression was significiantly higher both in upper and lower crypts in BE (P < 0.05). The present study showed that a Barrett pattern does not seem to exist; however, the analysis of COX2 expression and the Ki67 proliferation fraction by immunohistochemistry can be used to separate BE from non-Barrett's metaplasia of the distal esophagus. In our point of view, the immunohistochemical detection of p53 expression in Barrett's metaplasia stage is useless as a marker for early detection of high-risk patients.

Cytokeratin expression profiling in gastric carcinoma: clinicopathologic significance and comparison with tumor-associated molecules

OBJECTIVE

The expressions of cytokeratin (CK) 7 and 20 have been studied in various primary and metastatic carcinomas, and their determination may help distinguish the site of origin of metastatic carcinomas. However, little is known about the molecular basis that determines variations in CK patterns in gastric cancers (GCs). The aim of the present study was to analyze the CK expression patterns in a large number of GCs and to investigate how the CK patterns correlate with clinicopathologic parameters, histology, mucin phenotype or several tumor-related molecules.

METHODS AND RESULTS

We immunohistochemically examined the CK7/CK20 patterns, mucin expression profiles (MUC5AC, MUC6, MUC2 and CD10), and the cancer-related molecules (CDX2, p53, EGFR and β-catenin), using a tissue microarray with 870 GCs. The GCs were divided into four patterns; 17% of CK7+/CK20+, 57% of CK7+/CK20-, 9% of CK7-/CK20+ and 17% of CK7-/CK20. GCs with the CK7-/CK20- pattern demonstrated a close relation to undifferentiated adenocarcinoma. CK7 expression was significantly correlated with the expression of MUC5AC and MUC6, while CK20 expression was correlated with MUC2 and CDX2. There were statistically significant associations between CK expression patterns and mucin phenotypes.

CONCLUSION

These results indicate that the CK7/CK20 expression patterns in GCs demonstrated different clinicopathologic features and molecular signatures.

Detection of circulating tumor cells in breast cancer patients utilizing multiparameter flow cytometry and assessment of the prognosis of patients in different CTCs levels

We wanted to demonstrate the value of multiparameter flow cytometry in detecting human tumor cells of breast cancer (BC) (SKBR-3) in normal peripheral blood. In addition, we investigated a cluster of patients to compare the overall survival (OS) between advanced BC patients [circulating tumor cells (CTCs) >or=5 group] and limited BC patients (CTCs <5 group). SKBR-3 human BC cells were serially diluted in normal whole blood to demonstrate the sensitivity of multiparameter flow cytometry for detecting CTCs, and we also compared the specificity with reverse transcriptase polymerase chain reaction (RT-PCR) method. On the other hand, we detected CTCs among 45 patients by multiparameter flow cytometry. OS was calculated by the Kaplan-Meier product limit method, and compared it between CTCs <5 and CTCs >or=5 groups with the log-rank test. Cox regression models were fitted to determine the associated factors on survival. Human BC cells (SKBR-3) could be differentiated from normal blood based on the multiple light scatter and cell surface marker expression by multiparameter flow cytometry. The method was found to have a sensitivity limit of 10(-5) and was effective for detecting human BC cells in vivo. It also found that this method had a higher specificity compared with RT-PCR. For the retrospective study, the median OS was 95 weeks and 65.5 weeks (P < 0.05, 2-tailed) for patients with CTCs <5 and CTCs >or=5, respectively. Kaplan-Meier was used to analyze the patients' survival with Log Rank P = 0.004 and Breslow P = 0.003, which showed that these two groups had statistically significant difference. Cox regression analysis was performed, and we found CTCslevels, metastasis and age (P < 0.05) were three relative factors for patients' survival. Multiparameter flow cytometry can detect CTCs effectively and has the potential to be a valuable tool for prognosis assessment among BC patients in clinical situations in China.

HERG1 gene expression as a specific tumor marker in colorectal tissues

INTRODUCTION

Colorectal carcinomas exhibit a frequent recurrence after curative surgery, which may partially be due to histopathologically inconspicuous minimal residual disease. Reliable markers for tumor cells in colorectal tissue are still missing. Therefore, in this study we compared the predictive value of the putative tumor markers carcinoembryonic antigen (CEA), cytokeratin-19 (CK19) and cytokeratin-20 (CK20) to that of a novel marker, the human ether-a-go-go-related gene (HERG1) K(+) channel, a suggested regulator of tumor cell proliferation.

MATERIALS AND METHODS

Using RT-PCR we studied HERG, CEA, CK19 and CK20 expression in colorectal carcinomas and non-carcinoma controls. HERG1 immunhistochemistry was performed in a total of 66 specimens, in colorectal carcinoma (n = 23), in matched histopathologically negative samples (n = 23) taken near the excision site from the same tumor patients and in healthy control biopsies (n = 20). In order to verify the relevance of HERG1 for tumor proliferation we studied the effect of HERG1 inhibition in the Colo-205 colon cancer carcinoma cell line using the MTT-assay.

RESULTS

HERG1 was expressed in all tumor samples regardless of their stage and in adenomas larger than 0.4 cm, but absent in small adenomas, sigmadiverticulitis specimen and healthy histopathologically negative samples, except for one which developed a tumor recurrence. In contrast, CEA, CK19 and CK20 were absent in some tumors. The selective HERG1 inhibitor E-4031 dose-dependently impaired tumor growth in the proliferation assays.

DISCUSSION

Our data indicate that HERG1, but not CEA, CK19 or CK20, is a highly sensitive and reliable tumor biomarker that may constitute a novel molecular target for tumor treatment.

A factor graph nested effects model to identify networks from genetic perturbations

Complex phenotypes such as the transformation of a normal population of cells into cancerous tissue result from a series of molecular triggers gone awry. We describe a method that searches for a genetic network consistent with expression changes observed under the knock-down of a set of genes that share a common role in the cell, such as a disease phenotype. The method extends the Nested Effects Model of Markowetz et al. (2005) by using a probabilistic factor graph to search for a network representing interactions among these silenced genes. The method also expands the network by attaching new genes at specific downstream points, providing candidates for subsequent perturbations to further characterize the pathway. We investigated an extension provided by the factor graph approach in which the model distinguishes between inhibitory and stimulatory interactions. We found that the extension yielded significant improvements in recovering the structure of simulated and Saccharomyces cerevisae networks. We applied the approach to discover a signaling network among genes involved in a human colon cancer cell invasiveness pathway. The method predicts several genes with new roles in the invasiveness process. We knocked down two genes identified by our approach and found that both knock-downs produce loss of invasive potential in a colon cancer cell line. Nested effects models may be a powerful tool for inferring regulatory connections and genes that operate in normal and disease-related processes.

Biological processes are the result of the actions and interactions of many genes and the proteins that they encode. Our knowledge of interactions for many biological processes is limited, especially for cancer where genomic alterations may create entirely novel pathways not present in normal tissue. Perturbing gene expression (for example, by deleting a gene) has long been used as a tool in molecular biology to elucidate interactions but is very expensive and labor intensive. The search for new genes that may participate can be a daunting “fishing expedition.” We have devised a tool that automatically infers interactions using high-throughput gene expression data. When a gene is silenced, it causes other genes to be switched on or off, which provide clues about the pathway(s) in which the gene acts. Our method uses the genomewide on/off states as a fingerprint to detect interactions among a set of silenced genes. We were able to elucidate a network of interactions for several genes implicated in metastatic colon cancer. Genes newly connected to the network were found to operate in cancer cell invasion in human cells, validating the approach. Thus, the method enables an efficient discovery of the networks that underlie biological processes such as carcinogenesis.

Biomarker panel diagnosis of thyroid cancer: a critical review

The accurate preoperative diagnosis of thyroid cancer continues to be a significant challenge for those individuals who present with nodular thyroid disease, particularly for tumors with indeterminate cytomorphological features by fine-needle aspiration biopsy. In an effort to develop improved diagnostic tools, a number of studies have investigated the discriminatory potential of many different RNA and protein molecules. However, no individual thyroid cancer biomarker has been found with sufficient sensitivity and specificity. Therefore, research focus has shifted to panels of multiple markers with the hope of improved performance and robustness. A panel comprised of GAL3, CK19 and HBME1 is by far the most studied to date and offers some improvement over individual marker performance alone. However, relatively few marker panels have been studied and their performances and application as diagnostic tests have not been consistently reported. We present a comprehensive review of molecular marker panel studies for thyroid tumors and current issues and challenges. In the future, studies evaluating larger numbers of biomarkers in large patient cohorts are required for the development and validation of a clinically applicable test.

Cytokeratin and CDX-2 expression in Barrett's esophagus

OBJECTIVE

Barrett's esophagus (BE) is a premalignant condition of the distal esophagus. For diagnostic purposes it is important to find biomarkers that can specifically identify BE, for instance to differentiate BE epithelial cells from gastric cardia epithelial cells in brush cytology specimens. The objective of this study was to determine the specificity of CDX-2 and a set of cytokeratins (CKs) as specific markers for BE as compared with normal squamous esophageal and gastric cardia tissue.

MATERIAL AND METHODS

Immunohistochemistry (IHC) with specific antibodies against CDX-2, and a set of CKs was performed on fresh frozen consecutive tissue sections of normal squamous, gastric cardia and non-dysplastic BE of 80 patients.

RESULTS

IHC results showed CK8, CK18 and CK20 expression in both BE and gastric cardia, while CK7 was seen in all BE but also in 26% of gastric cardia biopsies. CK10/13 was only expressed in normal squamous epithelium. CDX-2 nuclear staining was found in 87.5% of the BE biopsies, whereas normal squamous esophagus and cardia biopsies were negative.

CONCLUSIONS

CDX-2 in combination with a set of CKs can be used as biomarkers to distinguish between BE and normal squamous esophagus. In order to distinguish BE from cardia tissue, a combination of CDX-2 and CK7 is most informative.

Primary cultures of human urothelial cells for genotoxicity testing

A cell culture system with human-derived urothelial cells was established based upon previous experience with cultures of porcine urinary bladder epithelial cells. Human tissue specimens used were derived from urinary bladders (n = 17) or ureters (n = 50) of patients undergoing urological operations. The epithelial origin and differentiation status was evaluated by an immunohistochemical staining for cytokeratins 7, 8, 18, 19, and 20 for isolated and cultured cells. Specimens from human ureters were better suited for primary cell cultures of the urothelium than specimens from human urinary bladders. Successful attachment and proliferation were reached by 98% of the ureter specimens (urinary bladder: 71%) and confluency was reached by 78% of the ureter cultures (urinary bladder: 18%). In the first 14 d of culture the cytokeratin patterns of cultured cells were comparable to those of native mucosa cells. During prolonged cell culture the cytokeratin patterns of the human urothelial cells (HUC) changed into a beginning dedifferentiation: Cytokeratin (CK) 18 was only detectable in cell cultures cultured for more than 29 d, whereas CK 19 was not detectable at d 29. Cell cultures of primary human urothelial cells may be used for in vitro testing of cytotoxic or genotoxic effects.

The serum assay of tumour markers in the prognostic evaluation, treatment monitoring and follow-up of patients with cervical cancer: a review of the literature

Pre-treatment serum squamous cell carcinoma antigen [SCC] levels are elevated in 28-88% of patients with squamous cell cervical cancer, and are related to tumour stage, tumour size, depth of stromal invasion, lymph-vascular space status, parametrial involvement and lymph node status. The clinical relevance of pre-treatment serum SCC assay is still debated. Some authors reported that it has no prognostic value, some others found that it is related to survival at univariate analysis, and some others detected that is an independent prognostic variable for survival. Serial SCC measurements reflect both the tumour response to treatment and the clinical outcome of patients. Increasing SCC levels can precede the clinical diagnosis of recurrent disease in 46-92% of the cases, with a mean lead time ranging from 2 to 8 months. According to some authors serum SCC assay during the follow-up does not improve the cure rate of patients who will ultimately develop a recurrence. However, it has been recently reported that the performance of a positron emission tomography [PET] in patients with asymptomatic SCC elevation can sometimes allow an earlier diagnosis of relapse with a survival benefit. SCC is a more sensitive serum tumour marker than CYFRA 21-1 for squamous cell cervical cancer in most series. Pre-treatment CA 125 levels are raised in 20-75% of patients with cervical adenocarcinoma, and reflect tumour stage, tumour size, histological grade, cervical stromal invasion, lymph-vascular space status and lymph node status. Elevated serum CA 125 has been also detected in patients with squamous cell cervical cancer, but with a positivity rate lower than that found in patients with cervical adenocarcinoma. Pre-treatment CA 125 levels appear to have a prognostic value, and rising serum CA 125 during follow-up may precede or be coincident with the clinical diagnosis of recurrent cervical adenocarcinoma. Serum levels of vascular endothelial growth factor [VEGF] are often elevated in patients with cervical cancer, and decrease significantly after successful treatment. However, the clinical relevance of serum VEGF assay is still investigational.

Immunohistochemical diagnosis of canine ovarian epithelial and granulosa cell tumors

In humans and canines, the morphology of granulosa cell tumors is extremely variable and causes diagnostic difficulties. In human pathology, immunohistochemistry has been widely used for the diagnosis of granulosa cell tumors, whereas, limited studies are present in canine species. The aim of this study was to investigate the expression of cytokeratins, vimentin, and inhibin-alpha in canine normal ovaries, epithelial ovarian tumors, and granulosa cell tumors to establish an immunohistochemical panel for the differential diagnosis of ovarian tumors. Formalin-fixed, paraffin-embedded tissue sections from 4 normal ovaries, 8 granulosa cell tumors, and 6 epithelial ovarian tumors (2 adenomas and 4 adenocarcinomas) sections were obtained and stained with hematoxylin and eosin and immunohistochemically for cytokeratin AE1/AE3, cytokeratin 7, vimentin, and inhibin-alpha. In normal ovaries, cytokeratin 7, cytokeratin AE1/AE3, and vimentin were expressed in the surface epithelium. Granulosa cells were negative for cytokeratin 7 and displayed variable expression of vimentin, cytokeratin AE1/AE3, and inhibin-alpha toward follicular maturation. Granulosa cell tumors were negative for cytokeratin 7 and positive for inhibin-alpha. Conversely, ovarian epithelial cells tumors were positive for cytokeratin 7 and negative for inhibin-alpha. Both granulosa and epithelial cell tumors displayed variable expression of vimentin. Cytokeratin AE1/AE3 was expressed by all epithelial-derived tumors and 6 of 8 granulosa cell tumors. The results of this study suggest that useful immunohistochemical markers to distinguish epithelial ovarian tumors from granulosa cell tumors are cytokeratin 7 and inhibin-alpha.

Immunonanoparticles − an effective tool to impair harmful proteolysis in invasive breast tumor cells

Breast cancer cells exhibit excessive proteolysis, which is responsible for extensive extracellular matrix degradation, invasion and metastasis. Besides other proteases, lysosomal cysteine protease cathepsin B has been implicated in these processes and the impairment of its intracellular activity was suggested to reduce harmful proteolysis and hence diminish progression of breast tumors. Here, we present an effective system composed of poly(D,L-lactide-coglycolide) nanoparticles, a specific anti-cytokeratin monoclonal IgG and cystatin, a potent protease inhibitor, that can neutralize the excessive intracellular proteolytic activity as well as invasive potential of breast tumor cells. The delivery system distinguishes between breast and other cells due to the monoclonal antibody specifically recognizing cytokeratines on the membrane of breast tumor cells. Bound nanoparticles are rapidly internalized by means of endocytosis releasing the inhibitor cargo within the lysosomes. This enables intracellular cathepsin B proteolytic activity to be inhibited, reducing the invasive and metastatic potential of tumor cells without affecting proteolytic functions in normal cells and processes. This approach may be applied for treatment of breast and other tumors in which intracellular proteolytic activity is a part of the process of malignant progression.

Bone morphogenetic protein 4 expressed in esophagitis induces a columnar phenotype in esophageal squamous cells

BACKGROUND & AIMS

Barrett's esophagus (BE) is a metaplastic condition in which normal squamous esophageal epithelium is replaced by columnar epithelium. It is proposed that one of the possible mechanisms is dedifferentiation of squamous epithelium into columnar epithelium. The pathophysiology through which this metaplasia occurs is unknown. A recent study by serial analysis of gene expression showed that bone morphogenetic protein 4 (BMP-4) is uniquely expressed in BE. In this study, the role of the BMP pathway in the metaplastic transformation of normal squamous cells into columnar cells was examined.

METHODS

Tissues from patients with esophagitis and BE and in an esophagitis-BE rat model were examined for the activation of the BMP pathway. Short-term cultures of primary normal squamous esophageal cells were treated with BMP-4, and cell biological changes were examined by Western blot analysis, immunohistochemistry, and microarrays.

RESULTS

In both human and rat tissues, the BMP pathway proved to be activated in esophagitis and BE. Upon incubation of squamous cell cultures with BMP-4, the cytokeratin expression pattern showed a shift that was consistent with columnar epithelium. Involvement of the BMP pathway was suggested by up-regulation of Phosphorylated-Smad 1/5/8 (P-Smad 1/5/8) that was effectively blocked by Noggin, a BMP antagonist. Comparison of the gene expression profiles of squamous cells, BMP-4-treated squamous cells, and BE cells showed a significant shift in the profile of the BMP-4-treated squamous cells toward that of the cultured BE cells.

CONCLUSIONS

These results suggest that the BMP pathway could play a role in the transformation of normal esophageal squamous cells into columnar cells.

The use of cytokeratin stain to distinguish Barrett's esophagus from contiguous tissues: a systematic review

Our objective was to systematically review the existing literature regarding the use of cytokeratin (CK) stain in differentiating Barrett's esophagus (BE) from tissues of the gastric cardia, corpus, or antrum, with or without intestinal metaplasia (IM). Pubmed was searched for full publications in English (1983-2005) addressing the use of CK for differentiation of BE from contiguous tissues. Information was collected on the study sample, blinding, the methods used for CK staining, and for defining and applying the gold standard tests. Test characteristics were obtained or calculated. Sixteen studies (containing 46 comparisons) met the inclusion and exclusion criteria. Immunostaining for CK 7 and 20 was generally highly specific in distinguishing long-segment BE from antrum IM, fundus IM, or noncardiac gastric IM; 27 comparisons showed statistically significant differences. However, only 8 of 15 comparisons (6 of 12 studies) reported significant differences in CK staining patterns between BE and gastric cardia IM with a high sensitivity (89%-100%) and specificity (83%-100%) for long-segment BE and lower estimates for short-segment BE, while the other seven comparisons showed no significant differences and a very low sensitivity. Examination by a blinded pathologist was reported in five of six positive studies and in only one of six of the negative studies. In addition, variation in the patient populations, use of surgical resection versus endoscopic biopsies, and biopsy sampling technique in endoscopic studies may have accounted for these differences. Finally, two studies did not find significant differences in CK staining patterns between BE and normal cardiac mucosa. In conclusions, CK immunostaining has not performed well in differentiating BE, especially short-segment BE, from cardia IM. There seems to be a spectrum bias where the accuracy varies with different tested populations. CK immunostaining distinguished well between BE and IM in noncardiac segments of the stomach; however, these comparisons are not clinically relevant.

Cytokeratin Markers Come of Age

Cytokeratins have been extensively used as serum tumour markers for monitoring of disease progression in cancer patients. The source of cytokeratins in the circulation as well as the mechanisms of release from cells have long been unclear. Recent evidence suggests that cytokeratins present in the circulation of cancer patients are released from apoptotic or necrotic tumour cells. CK18 is cleaved by caspases during apoptosis and a monoclonal antibody (M30) specific to caspase-cleaved forms is available. The molecular form of CK18 released from cells (caspase-cleaved or not) can conveniently be determined by immunoassays (M30-Apoptosense and M65 ELISA assays; Peviva AB, Bromma, Sweden) to determine cell death mode--apoptosis or necrosis. Recent studies where these assays were used to evaluate the response to cytotoxic anticancer drugs using cancer patient serum have been encouraging. CK18 is attracting considerable interest as a response biomarker during clinical trials of anticancer drugs. Properties such as excellent antigen stability and the epithelial specificity of cytokeratins contribute to make this biomarker attractive.

Bioinformatic screening of human ESTs for differentially expressed genes in normal and tumor tissues

Background

Owing to the explosion of information generated by human genomics, analysis of publicly available databases can help identify potential candidate genes relevant to the cancerous phenotype. The aim of this study was to scan for such genes by whole-genome in silico subtraction using Expressed Sequence Tag (EST) data.

Methods

Genes differentially expressed in normal versus tumor tissues were identified using a computer-based differential display strategy. Bcl-xL, an anti-apoptotic member of the Bcl-2 family, was selected for confirmation by western blot analysis.

Results

Our genome-wide expression analysis identified a set of genes whose differential expression may be attributed to the genetic alterations associated with tumor formation and malignant growth. We propose complete lists of genes that may serve as targets for projects seeking novel candidates for cancer diagnosis and therapy. Our validation result showed increased protein levels of Bcl-xL in two different liver cancer specimens compared to normal liver. Notably, our EST-based data mining procedure indicated that most of the changes in gene expression observed in cancer cells corresponded to gene inactivation patterns. Chromosomes and chromosomal regions most frequently associated with aberrant expression changes in cancer libraries were also determined.

Conclusion

Through the description of several candidates (including genes encoding extracellular matrix and ribosomal components, cytoskeletal proteins, apoptotic regulators, and novel tissue-specific biomarkers), our study illustrates the utility of in silico transcriptomics to identify tumor cell signatures, tumor-related genes and chromosomal regions frequently associated with aberrant expression in cancer.

Expanding the protein catalogue in the proteome reference map of human breast cancer cells

In this report we present a catalogue of 162 proteins (including isoforms and variants) identified in a prototype of proteomic map of breast cancer cells. This work represents the prosecution of previous studies describing the protein complement of breast cancer cells of the line 8701-BC, which has been well characterized for several parameters, providing to be a useful model for the study of breast cancer-associated candidate biomarkers. In particular, 110 spots were identified ex novo by PMF, or validated following previous gel matching identification method; 30 were identified by N-terminal microsequencing and the remaining by gel matching with maps available from our former work. As a consequence of the expanded number of proteins, we have updated our previous classification extending the number of protein groups from 4 to 13. In order to facilitate comparative proteome studies of different kinds of breast cancers, in this report we provide the whole complement of proteins so far identified and grouped into the new classification. A consistent number of them were not described before in other proteomic maps of breast cancer cells or tissues, and therefore they represent a valuable contribution for breast cancer protein databases and for future application in basic and clinical researches.

Cyclooxygenase-2 expression is higher in ovarian cancer tissue adjacent to endometriosis than in ovarian cancer without comorbid endometriosis

OBJECTIVES

The purpose of this study was to examine if COX-2, CK7 and CK20 are involved in the malignant transformation of endometriosis.

METHODS

We compared COX-2, CK7 and CK20 expressions between isolated endometriosis lesions and endometriosis lesions adjacent to ovarian carcinoma and between isolated ovarian carcinoma and ovarian carcinoma with implants of endometriosis. Immunoreactivity was quantified using an immunohistochemical scoring system that corresponds to an image analysis-based system.

RESULTS

There was no difference in COX-2, CK7 and CK20 expressions between the isolated endometriosis lesions and the endometriosis lesions adjacent to ovarian carcinoma. Similarly, CK7 and CK20 were equally expressed between the isolated ovarian carcinoma and the ovarian carcinoma with implants of endometriosis. The COX-2 over-expression rate was greater in ovarian carcinoma that was associated with endometriosis than in isolated ovarian carcinoma (27.8% versus 5.6%, P = 0.083). In endometrioid type ovarian carcinoma, the difference in COX-2 expression was statistically significant (50% versus 0%, P = 0.023).

CONCLUSIONS

COX-2 over-expression may be a result of the malignant transformation of endometriosis to endometrioid type ovarian cancer or may represent an interaction between the two cellular components. With respect to cytokeratins, neither CK7 nor CK20 appear to be involved in the malignant transformation of endometriosis.

Observation of circulating tumour cells in patients with non-small cell lung cancer by real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction in peroperative period

PURPOSE

To assess whether surgical manoeuvre or resection of lung cancer could lead to haematogenous dissemination of malignant cells. In the mean time, the relationship between the sequence of vessel ligation and the haematogenous dissemination of cancer cells during operation was determined.

METHODS

Exploiting cytokeratin 19 (CK19)/carcinoembryonic antigen (CEA) mRNA as markers, 69 peripheral blood samples were collected from 23 consecutive patients with non-small cell lung cancer (NSCLC) who underwent surgical resection with curative intention in preoperative, intraoperative and postoperative period, respectively. Before the operation, all patients were randomly assigned to one of the two surgical procedure groups according to the order of vessel ligation, PV-first group and PA-first group. Additionally, the ten patients with benign lung disease served as control subjects undergoing surgical resection. The quantity and timing of the shedding of lung cancer cells into the circulation of patients were also monitored by fluorescent quantitative-reverse transcriptase-polymerase chain reaction before, during and after surgery.

RESULTS

(1) The CK19 diagnostic test: the value of CK19 mRNA in operation was significantly higher than that of preoperation (5.246+/-0.196 vs. 4.472+/-0.164, P=0.000) and postoperation (5.246+/-0.196 vs. 4.694+/-0.177, P=0.013). The values between adenocarcinoma and squamous carcinoma were strikingly different (4.9110+/-1.0315 vs. 4.1891+/-0.4126, t=2.364, P=0.028). The values between PV-first group and PA-first group during perioperative period appear to be different (4.503 vs. 5.085, P=0.086). Before operation, of the 23 cases studied, 14 cases were positive (60.9%). Surprisingly, circulating epithelial cells were detected in two patients resected for benign lung disease. (2) The CEA diagnostic test: the level of CEA mRNA ascended continuously within this period. The postoperative values were significantly higher than those of preoperation (4.874 vs. 4.483, P=0.000) and those of operative day (4.874 vs. 4.537, P=0.000). The values between PV-first group and PA-first group appear to reach statistical significance (4.397 vs. 4.817, P=0.075). At the same time, there was a correlation between preoperative T-stage and perioperative CEA mRNA (4.267 vs. 4.760, P=0.025). Among the 23 cases, 10 cases were positive (43.5%). Both patients with benign lung disease served as control subjects undergoing surgical resection and the volunteers were negative.

CONCLUSIONS

A considerable proportion of patients who appear to have resectable NSCLC might be regarded as having systemic disease, which is often undetectable by current tumour staging method. In terms of a marker used for the NSCLC patients who undergo operation, CEA is more suitable than CK19. The CK19-expressing epithelial cells are released intraoperatively into the circulation, meanwhile CEA-expressing tumour cells are disseminated mostly postoperatively. Surgical manipulation could promote the release of tumour cells into the bloodstream, but the ligation of pulmonary vein before the ligation of the pulmonary artery may partly prevent such release during surgery.

Detection and quantification of circulating tumor cells in mouse models of human breast cancer using immunomagnetic enrichment and multiparameter flow cytometry

BACKGROUND

Circulating tumor cells (CTCs) in the peripheral blood of breast cancer patients may be an important indicator of metastatic disease and poor prognosis. However, the use of experimental models is required to fully elucidate the functional consequences of CTCs. The purpose of this study was to optimize the sensitivity of multiparameter flow cytometry for detection of human tumor cells in mouse models of breast cancer.

METHODS

MDA-MB-468 human breast cancer cells were serially diluted in whole mouse blood. Samples were lysed and incubated with a fluorescein isothiocyanate-conjugated anti-human leukocytic antigen antibody and a phycoerythrin-conjugated anti-mouse pan-leukocyte CD45 antibody. Samples were then immunomagnetically depleted of CD45-positive leukocytes, fixed, permeabilized, and stained with propidium iodide before flow cytometric analysis.

RESULTS

Human breast cancer cells could be differentiated from mouse leukocytes based on increased light scatter, cell surface marker expression, and aneuploid DNA content. The method was found to have a lower sensitivity limit of 10(-5) and was effective for detecting human breast cancer cells in vivo in the circulation of experimental mice carrying primary human mammary tumors.

CONCLUSIONS

This technique has the potential to be a valuable and sensitive tool for investigating the biological relevance of CTCs in experimental mouse models of breast cancer.

Cyclopedic protein expression analysis of cultured canine mammary gland adenocarcinoma cells from six tumours

We characterised cultured canine mammary gland adenocarcinoma cells by exhaustive step protein expression analysis to identify factors associated with tumour progression or metastasis of canine mammary gland tumour. Cultured adenocarcinoma cells derived from a total of 3 primary and 3 metastatic lesions from 3 dogs (CHMp/m, CIPp/m and CNMp/m, where CHM, CIP, and CNM indicate the 3 animals) were used in this study. The expression of 24 proteins reported to be related to tumourigenesis or malignancy of human breast cancers were examined by Western blot analysis using 24 antibodies. The expression of sialyl Lewis X [sLe(x)] was only observed in CHMm cells, which were derived from pleural effusion. This expression was further confirmed by immunohistochemistry. The levels of some factors, such as 14-3-3sigma, cyclinD1 and Rb, differed among cells or between the primary and metastatic cells in the pair. Though the difference in their expression was not consistent within the cells from primary and metastatic origin, this characterisation should provide useful information for further molecular analysis of these cultured cells. Since some of the factors, such as sLe(x), 14-3-3sigma, cyclinD1 and Rb, showed different levels of expression in the pair, these cultured cells might be meaningful tools for clarification of distant metastasis in canine mammary gland tumours.

Unique expression of MUC3, MUC5AC and cytokeratins in salivary gland carcinomas

The differential diagnosis of salivary gland carcinoma is often difficult because of the confusing histopathological features of the different types of salivary gland carcinomas. The expression of MUC3, MUC5AC, MUC6, cytokeratin (CK)7 and CK20 was studied in 20 mucoepidermoid carcinomas (MEC), 20 adenoid cystic carcinomas (AdCC), and 11 acinic cell carcinomas (ACC). All the cases (51/51, 100%) were positive for CK7, but they were not positive for CK20. All the cases (100%) of the MEC were positive for MUC5AC, while all MEC (100%) were negative for MUC3. Only two cases (10%) were positive for MUC6. All cases (100%) of AdCC were negative for MUC3, MUC5AC and MUC6. Eight cases (73%) of ACC were positive for MUC3, but all the cases (100%) were negative for MUC5AC and MUC6. It is concluded that the positive expression of MUC5AC is very unique to MEC, and that the positive expression of MUC3 is very unique to ACC. These findings will be very useful for the differential diagnosis of the salivary gland carcinomas.

Is cytokeratin immunoreactivity useful in the diagnosis of short-segment Barrett's oesophagus in Korea?

BACKGROUND

Cytokeratin 7/20 staining has been reported to be helpful in diagnosing Barrett's oesophagus and gastric intestinal metaplasia. However, this is still a matter of some controversy.

OBJECTIVE

To determine the diagnostic usefulness of cytokeratin 7/20 immunostaining for short-segment Barrett's oesophagus in Korea.

METHODS

In patients with Barrett's oesophagus, diagnosed endoscopically, at least two biopsy specimens were taken from just below the squamocolumnar junction. If goblet cells were found histologically with alcian blue staining, cytokeratin 7/20 immunohistochemical stains were performed. Intestinal metaplasia at the cardia was diagnosed whenever biopsy specimens taken from within 2 cm below the oesophagogastric junction revealed intestinal metaplasia. Barrett's cytokeratin 7/20 pattern was defined as cytokeratin 20 positivity in only the superficial gland, combined with cytokeratin 7 positivity in both the superficial and deep glands.

RESULTS

Barrett's cytokeratin 7/20 pattern was observed in 28 out of 36 cases (77.8%) with short-segment Barrett's oesophagus, 11 out of 28 cases (39.3%) with intestinal metaplasia at the cardia, and nine out of 61 cases (14.8%) with gastric intestinal metaplasia. The sensitivity and specificity of Barrett's cytokeratin 7/20 pattern were 77.8 and 77.5%, respectively.

CONCLUSION

Barrett's cytokeratin 7/20 pattern can be a useful marker for the diagnosis of short-segment Barrett's oesophagus, although the false positive or false negative rate is approximately 25%.

Cytokeratin immunoreactivity patterns in short-segment Barrett's esophagus in Japanese patients

BACKGROUND

The origin of intestinal metaplasia at the esophagogastric junction has clinical importance. However, it can be difficult to differentiate between intestinal metaplasia of short-segment Barrett's esophagus and cardiac intestinal metaplasia due to Helicobacter pylori infection. Specific patterns of cytokeratin (CK)7 and CK20 have been detected in long-segment Barrett's esophagus. The aim of the present study was to assess the immunostaining patterns associated with short-segment Barrett's esophagus.

AIMS

Paraffin-embedded biopsy specimens were prepared from 128 patients with intestinal metaplasia of long-segment Barrett's esophagus (n = 3), short-segment Barrett's esophagus without H. pylori infection (n = 22), short-segment Barrett's esophagus with H. pylori infection (n = 22), and cardiac mucosa (n = 49) and gastric mucosa from antrum and fundus (n = 44) with H. pylori infection. Sections were prepared and immunostained for CK7 and CK20.

RESULT

A Barrett's CK7/20 pattern was present in all three patients (100%) with long-segment Barrett's esophagus, 21 of 22 patients (95%) with short-segment Barrett's esophagus without H. pylori infection, and six of 22 patients (27%) with short-segment Barrett's esophagus with H. pylori infection (P < 0.05).

CONCLUSION

Intestinal metaplasia of short-segment Barrett's esophagus in patients without H. pylori infection is thought to be similar to that seen in long-segment Barrett's esophagus.

Cytokeratins 7 and 20 and mucin core protein expression in esophageal cervical inlet patch

Cervical inlet patch (CIP) is defined by the presence of gastric mucosa within the first few centimeters of the esophagus. Several endoscopic series have demonstrated a frequent association of CIP with Barrett's esophagus (BE) suggesting a pathogenetic link. A histochemical study reporting the presence of acid mucin in CIP, including sulfomucin, supports this hypothesis. We evaluated mucin core protein expression and cytokeratins 7 and 20 (CK7/CK20) pattern in biopsies of CIP, normal antrum, and BE to comment on a possible relationship of CIP with BE. We observed that both lesions have similar cytokeratin patterns with mixed CK7/CK20 reactivity on the surface and pits and lone CK7 positivity in the glands. MUC5AC was strongly expressed on the surface and pits but not in the glands of CIP and antral mucosa. Within BE, MUC5AC positivity was noted not only on the surface and pits but also in the glands. MUC6 similarly decorated the glands of CIP and BE. MUC2 was expressed rarely in CIP with goblet cells but conspicuously on the surface and pits of BE. MUC5B was seen in both CIP and BE and rarely in the antral mucosa. The similarities between CIP and BE but not with normal antral mucosa fits with the hypothesis that both lesions may originate from submucosal esophageal mucous glands. Two pathogenetic pathways can be entertained: focal upper esophageal mucosal misdevelopment in pediatric population and patchy metaplastic replacement of squamous mucosa in adults with gastroesophageal reflux disease.

Differential expression profiling of human pancreatic adenocarcinoma and healthy pancreatic tissue

Due to poor prognosis and lack of effective treatment, pancreatic carcinoma (PC) is a devastating disease. With the goal of contributing to an improved detection, prevention and treatment of the disease, a comparative proteome analysis of PC and normal tissue was carried out. Paired tissue extracts from 12 patients (pancreatic adenocarcinoma and adjacent healthy tissue) were separated by two-dimensional electrophoresis. Differential protein expression was analyzed by gel comparison with the help of image analysis software. The differentially expressed spots were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Seventy proteins were more strongly expressed (mostly two-fold or more) in cancerous tissue, while 41 were stronger in normal pancreas respectively. Those spots highly expressed in PC were confirmed in gels from independent individual samples. Among them were several cytoskeletal proteins, small GTP-binding proteins, and members of the S100 protein family etc. Nine proteins had been reported in previous nuclear acid-based studies. The levels of two proteins were confirmed by immunohistochemistry. One of them, fascin, was detected in 13 out of 21 carcinoma and negative in all normal pancreas samples. Moreover, fascin expression was related to the differentiation of pancreatic carcinoma.

Detection of circulating epithelial cells in the blood of patients with breast cancer: comparison of three techniques

This study compares the sensitivities and specificities of three techniques for the detection of circulating epithelial cells in the blood of patients with breast cancer. The number of circulating epithelial cells present in the blood of 40 patients with metastatic breast cancer and 20 healthy volunteers was determined by: immunomagnetic separation (IMS) and laser scanning cytometry (LSC), cell filtration and LSC and a multimarker real-time RT–PCR assay. Numbers of cytokeratin-positive cells identified and expression of three PCR markers were significantly higher in the blood of patients with breast cancer than in healthy volunteers. Using the upper 95% confidence interval of cells detected in controls to determine positive patient samples: 30% of patients with metastatic breast cancer were positive following cell filtration, 48% following IMS, and 60, 45 and 35% using real-time RT–PCR for cytokeratin 19, mammaglobin and prolactin-inducible peptide. Samples were significantly more likely to be positive for at least one PCR marker than by cell filtration (83 vs 30%, P<0.001) or IMS (83 vs 48%, P<0.001).The use of a multimarker real-time RT–PCR assay was therefore found to be the most sensitive technique for the detection of circulating epithelial cells in the blood of patients with breast cancer.

Iterative microarray and RNA interference-based interrogation of the SRC-induced invasive phenotype

Src kinase has long been recognized as a factor in the progression of colorectal cancer and seems to play a specific role in the development of the metastatic phenotype. In spite of numerous studies conducted to elucidate the exact role of Src in cancer progression, downstream targets of Src remain poorly understood. Gene expression profiling has permitted the identification of large sets of genes that may be functionally interrelated but it is often unclear as to which molecular pathways they belong. Here we have developed an iterative approach to experimentally reconstruct a network of gene activity regulated by Src and contributing to the invasive phenotype. Our strategy uses a combination of phenotypic anchoring of gene expression profiles and loss-of-function screening by way of RNA-mediated interference. Using a panel of human colon cancer cell lines exhibiting differential Src-specific activity and invasivity, we identify the first two levels of gene transcription responsible for the invasive phenotype, where first-tier genes are controlled by Src activity and the second-tier genes are under the influence of the first tier. Specifically, perturbation of first-tier gene activity by either pharmacologic inhibition of Src or RNA-mediated interference-directed knockdown leads to a loss of invasivity and decline of second-tier gene activity. The targeting of first-tier genes may be bypassed altogether because knockdown of second-tier genes led to a similar loss of invasive potential. In this manner, numerous members of a "transcriptional cascade" pathway for metastatic activity have been identified and functionally validated.

DNA microarray analysis of pancreatic malignancies

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment are needed. Recent advances in human genome research and high-throughput molecular technologies make it possible to cope with the molecular complexity of malignant tumors. With DNA array technology, mRNA expression levels of thousand of genes can be measured simultaneously in a single assay. As several studies using microarrays in PDAC have already been published, this review attempts to compare the published data and therefore to validate the results. In addition, the applied techniques are discussed in the context of pancreatic malignancies.

Prognostic and diagnostic significance of beta-catenin nuclear immunostaining in colorectal cancer

In the present study, we investigated the prognostic and diagnostic significance of beta-catenin nuclear immunostaining in 60 specimens of normal colorectal tissue; 180 specimens of colorectal polyps, adenomas, and carcinomas; and 40 specimens from patients with the simultaneous occurrence of polyps, adenomas, and carcinomas. Additional specimens from 59 patients with colorectal carcinoma and 14 patients with adenoma who subsequently developed carcinoma were examined for possible survival study. Immunohistochemical staining showed that the occurrence of nuclear beta-catenin correlated with the sequential stages in colorectal carcinogenesis, in which positive staining was observed in 0% of normal tissues, 8% of polyps, 92% of adenomas, and 100% of carcinomas. High immunohistochemical scores in colorectal carcinoma were significantly associated with lymph node metastasis and poor survival. Adenomas associated with synchronous or metachronous carcinomas showed significantly higher levels of nuclear beta-catenin compared with adenomas without associated carcinomas. Nuclear translocation of beta-catenin was rare or absent in other types of cytokeratin 20 positive adenocarcinomas examined (99 cases). Thus, it was positive in only 7% of colonic mucinous adenocarcinomas, 3% of pancreatic adenocarcinomas, 8% of ovarian mucinous cystadenocarcinomas, and 0% of gastric adenocarcinomas. However, 100% of primary and metastatic colorectal adenocarcinomas were positive for nuclear staining for beta-catenin. Thus, nuclear staining for beta-catenin may serve as an additional parameter to help distinguish colorectal adenocarcinomas from adenocarcinomas of other tissue sites. Collectively, the present large-scale study has clearly addressed the clinical significance of beta-catenin nuclear translocation with respect to tumor progression, survival, and differential diagnosis.

Expression of cytokeratins 7 and 20 in Helicobacter pylori-associated chronic gastritis in children

Helicobacter pylori gastric infection induces structural changes in the gastric epithelium. Among them, variations in the expression of cytokeratins have been reported in adult patients. In the present study, we describe the expression of CK7 and CK20 in gastric samples taken from the antrum in three groups of pediatric patients: (A) Helicobacter pylori-associated chronic gastritis (mean age: 11.4 years); (B) previous H. pylori chronic gastritis patients (mean age: 9.4 years); and (C) controls (mean age: 8.8 years). In all, the presence of sulfomucins was assessed with Alcian blue-periodic acid-Schiff pH 1.0. Immunoreactivity was graded as absent (0), weak (1+), moderate (2+), or intense (3+), in accordance with the intensity of the staining, and its distribution as focal or diffuse. CK7 reactivity was 2+ either focal or diffuse in all group A biopsies. The reactivity was more evident in the cells at the neck of the glands, in the areas with more inflammatory infiltrates, decorating long vertical segments of epithelium. In groups B and C, CK7 reactivity was also focal and 1+ at the cells of the necks of the glands. However, group B presented longer vertical segments of positive cells as compared to group C, and shorter than those of group A. The deeper glandular structures were focally 1+ in both groups. CK20 expression was comparable in all three groups, depicting a 2+ diffuse reactivity at the surface epithelium and interposed pits with absence or focal reactivity at the neck and coiled gland areas. Ki-67 immunostaining paralleled that of the CK7. Staining for sulfated mucosubstances was positive in two of five cases of groups A and B, and in none of the cases of group C. We conclude that: (1) the long segments of CK7-positive glandular necks in H. pylori cases most probably indicate intense regenerative activity during active inflammation; (2) eradication of H. pylori does not warrant ad integrum restitution since long segments of Ki-67+, CK7+ cells at the germinative compartment of the glands (as well as cells with sulfomucins) were still recognizable in ex- H. pylori patients; (3) finally, differing from what happens in adults, children somehow manage to maintain fully differentiated CK20+ superficial epithelium while the H. pylori is in action.

Circulating tumour cells in breast cancer

By use of modern immunological and molecular analytical techniques, cells with the characteristics of tumour cells can be detected in the blood of many patients with breast cancer. The ability to detect and characterise such cells routinely could have a profound influence on the early diagnosis of breast cancer, risk stratification in the adjuvant setting, early detection of relapse, and the development of new targeted strategies. In this review we discuss current techniques to detect circulating breast-cancer cells and the limitations of these approaches. We also review the clinical studies in breast cancer and discuss the potential relevance of this research to the future management of the disorder.

Development and characterization of a stable epithelial cell line from Muta Mouse lung

We have isolated and characterized a stable epithelial cell line from Muta Mouse lung that is a suitable complement to the in vivo assay system. The cells are contact inhibited, forming a flat monolayer, and retain several epithelial/pulmonary characteristics. The genome is stable across more than 50 generations, with a modal chromosome number of 78. Spontaneous rates of micronuclei (19.2 +/- 1.4 per 1,000), sister chromatid exchanges (0.25 +/- 0.004 per chromosome), and chromosome aberrations ( approximately 4%) are lower than, or comparable to, other transgenic cell lines currently used in mutagenicity research. Fluorescence in situ hybridization analyses showed that 80% of cells contain three lambdagt10lacZ loci. Slot-blot analyses indicated that the average cell contains approximately 17 transgene monomers. Spontaneous mutant frequency at the lacZ transgene is stable (39.8 +/- 1.1 x 10(-5)), and the direct-acting mutagens N-ethyl-N-nitrosourea and ICR-191 yielded increases in mutant frequency of 6.3- and 3.2-fold above control, respectively. Benzo[a]pyrene (BaP) exposure increased mutant frequency more than 25-fold above control and did not require an exogenous metabolic activation mixture. Inhibition of Cyp1A1 by 5 microM alpha-naphthoflavone eliminated BaP mutagenesis. Activation and mutation induction by the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine required a low concentration (0.05% v/v) of exogenous rat liver S9. High activity of alpha, micro, and pi glutathione-S-transferase isozymes appears to confer resistance to the cytotoxic effects of xenobiotics. The cell line is a suitable complement to the in vivo Muta Mouse assay, and provides an opportunity for routine in vitro mutagenicity testing using an endpoint that is identical to that employed in vivo.

Lymphoepithelioma-like carcinoma of the uterine cervix

CONTEXT

It has been proposed that Epstein-Barr virus (EBV) plays a role in the etiology of lymphoepithelioma-like carcinoma (LELC) in diverse anatomic locations. In contrast to Asian women, Western women have a low prevalence of LELC of the uterine cervix, and EBV genomes have not been identified.

OBJECTIVE

To assess the presence of EBV in LELC of the uterine cervix in 4 white Western women.

DESIGN

We collected 4 cases of LELC of the uterine cervix between 1990 and 2000. We performed histologic and immunohistochemical analyses of formalin-fixed, paraffin-embedded tumor samples. We amplified tumor DNA with polymerase chain reaction to detect EBV, human papillomavirus, and simian virus 40 DNAs.

RESULTS

Immunohistochemically, tumor cells were positive for cytokeratins and showed strong expression of p53 and MIB-1. Staining for the oncoprotein c-Erb-B2 was focally positive, and staining for Bcl-2 and progesterone receptors was negative. Only one case showed focal nuclear staining for estrogen receptors. All cases had a dense infiltrate of mature lymphocytes expressing T-cell antigens CD45RO, CD3, and CD8. Polymerase chain reaction analysis did not detect EBV, human papillomavirus, or simian virus 40 DNA sequences in any of the 4 cases. One case had positive serologic results for anti-EBV antibodies, indicating a mild or chronic infection.

CONCLUSIONS

LELC of the uterine cervix shows the immunohistochemical profile of an aggressive tumor in spite of its good prognosis, in which CD8 cytotoxic suppressor lymphocytes could play an important role. Based on our results, the role of EBV, human papillomavirus, or simian virus 40 in the pathogenesis of LELC of the uterine cervix in Western women remains unclear.

Carcinoembryonic Antigen, Squamous Cell Carcinoma Antigen, CYFRA 21-1, and Neuron-specific Enolase in Squamous Cell Lung Cancer Patients

Background: Carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag), and CYFRA 21-1 are the most useful markers for non-small cell lung cancer (NSCLC), but neuron-specific enolase (NSE) is a tumor maker of choice for SCLC. The determination of NSE in NSCLC could allow selection of patients with neuroendocrine features. NSCLC patients whose tumors have neuroendocrine properties may be more responsive to chemotherapy; however, these tumors have been reported to be more aggressive. Tumor markers are not suitable for diagnosis; their principal applications are in monitoring of therapy and prognosis.

Methods: Tumor markers were measured in 200 untreated patients with squamous cell lung cancer (SQC) and a reference group (n = 220; 124 healthy persons and 96 patients with nonmalignant lung disease). CEA and SCC-Ag were measured by microparticle enzyme immunoassays on Abbott AxSYM and IMx analyzers. CYFRA 21-1 and NSE were measured by electrochemiluminescence immunoassays on the Roche Elecsys 2010.

Results: CEA, SCC-Ag, CYFRA 21-1, and NSE were increased above the cutoffs in 26%, 32%, 67%, and 28% of tested patients, respectively. The area under the ROC curve for CYFRA 21-1 was higher than those for CEA, SCC-Ag, and NSE (SQC vs controls). CYFRA 21-1 and CEA were significantly higher in advanced SQC than in early stages of disease (P &lt;0.0001 and P &lt;0.0004, respectively). In multivariate analysis of survival, CYFRA 21-1 was an independent but nonspecific prognostic factor in the operable group of SQC patients, whereas NSE was an independent prognostic factor in the advanced stages of disease.

Conclusion: CYFRA 21-1 is an independent prognostic factor in earlier stages and NSE in the advanced stages of SQC.

Carcinoma arising in a proliferating trichilemmal cyst expresses fetal and trichilemmal hair phenotype

Carcinomas that arise in a proliferating trichilemmal cyst (PTC) have been described under a variety of names. Monoclonal antibodies (mAbs) indicating follicular differentiation have become available and were used here in two rare tumors with uncommon biologic behavior. To further elucidate the histogenesis of carcinomas arising in a PTC, mAbs to hair follicle stem cells and to hair follicle differentiation-specific cytokeratins (mAbs to cytokeratin [CK] 7, CK8, CK18, and CK19 as well as mAbs to CD8/CK15 and CD34) were studied on paraffin-embedded sections of two cases of carcinoma arising in a PTC, one anaplastic carcinoma, and one poorly differentiated squamous cell carcinoma (SCC). For comparison, concurrent PTCs and trichilemmal cysts as well as four SCCs from controls were studied. The anaplastic carcinoma showed expression of CK7, indicating a fetal hair root phenotype, and expression of CD34, indicating trichilemmal differentiation. In contrast, the poorly differentiated SCCs as well as the control SCCs stained negative for most of the mAbs applied. Expression of fetal and trichilemmal hair follicle phenotypes suggests differentiation from hair stem cells and might explain differences in biologic behavior.

Cancer-associated cleavage of cytokeratin 8/18 heterotypic complexes exposes a neoepitope in human adenocarcinomas

The intermediate filament network in simple glandular epithelial cells predominantly consists of heterotypic complexes of cytokeratin 8 (K8) and cytokeratin 18 (K18). In contrast to other cytokeratins, K8 and K18 are persistently expressed during malignant transformation, but changes in cell morphology are accompanied by alterations in the intermediate filament network. To study molecular changes, K8 and K18 were purified from surgically removed colon cancer and normal epithelia tissues. Western blotting and amino acid sequencing revealed the presence of abundant K8 and K18 fragments, truncated at the N terminus, from cancerous, but not normal, epithelial cells. The fragmentation pattern indicates proteolysis mediated by several enzymes, including trypsin-like enzymes. The cancer-associated forms of K8 and K18 are specifically recognized by the human antibody, COU-1, cloned from the B cells of a cancer patient. We demonstrate that COU-1 recognizes a unique conformational epitope presented only by a complex between K8 and K18. The epitope is revealed after proteolytic removal of the head domain of either K8 or K18. A large panel of recombinant K8 and K18 fragments, deleted N- or C-terminally, allowed for the localization of the COU-1 epitope to the N-terminal part of the rod domains. Using surface plasmon resonance, the affinity of COU-1 for this epitope was determined to be 10(9) x m(-1), i.e. more than 2 orders of magnitude higher than for intact heterotypic K8/K18 complexes. The cellular distribution of truncated K8/K18 heterotypic complexes in viable adenocarcinomas cells was probed using COU-1 showing small fibrillar structures distinct from those of intact K8/K18 complexes. Previously we demonstrated the binding and subsequent internalization of recombinant Fab COU-1 to live cancer cells. We have thus characterized a cancer neoepitope recognized by the humoral immune system. The results have biological as well as clinical implications.

Patterns of nestin and other intermediate filament expression distinguish between gastrointestinal stromal tumors, leiomyomas and schwannomas

The KIT-positive specific gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas are the three most common types of primary mesenchymal tumors of the gastrointestinal (GI) tract. The intermediate filaments are abundant cytoskeletal proteins commonly used as cell differentiation markers in diagnostic immunohistochemistry. Their patterns have not been fully characterized in GI mesenchymal tumors, and could offer differential diagnostically useful parameters. Very recently, nestin, a class VI intermediate filament expressed in neuroectodermal stem cells and skeletal muscle progenitor cells, has been shown in GISTs and suggested as a marker for these tumors. In this study we immunohistochemically examined the expression of nestin and other intermediate filament proteins, including desmin, keratins (Ks), glial fibrillary acidic protein (GFAP), neurofilament, and vimentin in GISTs of different sites, esophageal leiomyomas and GI schwannomas. Nestin was nearly consistently present in GISTs of different locations whether spindle cell or epithelioid, and benign or malignant. It was also detected in 23 of 24 (96%) GI schwannomas, whereas leiomyomas were uniformly negative. Vimentin was present in both GISTs and schwannomas, whereas it was typically absent in leiomyomas (25% positive, usually focally). Desmin was present in all leiomyomas, whereas only 3% of GISTs (4 of 140) were positive, and all schwannomas were negative. K18 was detected in a minority of GISTs, leiomyomas, and schwannomas. Malignant GISTs were more commonly keratin positive than the benign ones; there was 18% K18 positivity in malignant gastric and small intestinal GISTs, but 9% K18 positivity in benign gastric and small intestinal GISTs. Moreover, K8, albeit to a lesser degree, was detected in a minority of GISTs, but K7, K14, K19 and K20 were not detected. GFAP was present in the majority of schwannomas, whereas all GISTs were negative; some leiomyomas had weak cytoplasmic positivity. These results document distinctive patterns of intermediate filament proteins in GI mesenchymal tumors. Nestin is confirmed to be consistently expressed in GISTs but it is also present in most GI schwannomas; GFAP is helpful when separating GISTs and schwannomas, since only the latter are positive. The potential presence of K8 and K18 in GISTs should not lead to the misdiagnosis of carcinoma on biopsy.

Mapping of the keratin polypeptides in meningiomas of different types: an immunohistochemical analysis of 463 cases

Keratins are known to be expressed in some meningiomas, and they have been consistently reported in secretory meningiomas. However, the expression of individual keratin polypeptides has not yet been systematically explored, and such a study could provide important information for the differential diagnosis of meningioma and other tumors, particularly metastatic carcinomas. In this study we analyzed the keratin polypeptide patterns of 463 meningiomas of different types using well-characterized monoclonal antibodies specific to 11 individual keratins and 3 additional antibodies that recognize more than 1 keratin. Archnoid tissues from autopsies were examined for comparison. Secretory meningiomas showed consistent positivity for all simple epithelial keratins K7, K8, K18, and K19, usually limited to the slender spindle cells lining the gland-like lumina. Other keratins variably detected in a minority of gland-like structures were K5/6, K14, K16, and K17. Among other meningiomas, keratin 18 was commonly present in a significant number of tumor cells in different subtypes (30% to 80% of cases), often extensively. The K18 positivity of meningiomas paralleled that observed in normal arachnoids, which were negative for K7, K8, K19, and AE1. Only rare meningiomas, other than the secretory ones, had significant positivity for K7, K8, K19, and other keratins than K18. The concentric spindle cells around psammoma bodies and few other spindle cell foci were often focally positive for K7 and to lesser degree for K8, K14, and K19. The complex pattern of keratins in meningiomas has to be considered in the differential diagnosis of meningioma and metastatic carcinoma. In this context, antibodies to K7, K8, and K19 and the antibodies AE1 and AE3 are useful, because they only rarely label significant numbers of meningioma cells but are positive in a great majority of carcinomas. Careful histologic analysis is necessary to differentiate anaplastic meningiomas and metastatic carcinomas, which have overlapping patterns of several keratins except K20, which was never present in any type of meningioma.

Diagnostic value of cytokeratin-18 as a tumor marker in bladder cancer

OBJECTIVES

The aim of the study was to compare serum levels of cytokeratin-18 of patients with bladder cancer with those of the healthy controls, and to investigate the relation between cytokeratin level and the tumor stage.

DESIGN AND METHODS

Serum cytokeratin-18 levels of 38 patients with bladder cancer and of 25 healthy people were determined. Tumor stage was T(1) in 12 patients, T(2) in 9 patients, T(3) in 10 patients and T(4) in 7 patients. The serum cytokeratin-18 levels in these cases were analyzed with respect to the stage of the tumor.

RESULTS

Cytokeratin-18 level in the patient group was found to be significantly higher than that of the control group (p < 0.010) when the groups were totally compared. However, when the levels in patients with different tumor stages were compared with that of the controls, the difference was not significant in patients with stage 1 and 2 tumors (p > 0.05). Regarding the cut off value as 4.0 ng/mL, sensitivity and specificity for serum cytokeratin-18 were found to be 53% and 72% respectively. When sensitivity was calculated with respect to tumor stages, it was 8% for T(1,) 33% for T(2,) 90% for T(3) and 100% for T(4.) On the other hand, considering higher stage (T(3) and T(4)) tumors only, the sensitivity was calculated as 94%, but the sensitivity for lower stage (T(1) and T(2)) tumors was 19%.

CONCLUSIONS

It is clear that serum cytokeratin-18 level increases in patients with bladder cancer. However, it can only be useful as a tumor marker in the diagnosis of T(3) and higher staged tumors. This study indicated that cytokeratin-18 does not have any diagnostic value in lower stage bladder cancers.

Cytokeratin expression patterns in noncardia, intestinal metaplasia-associated gastric adenocarcinoma: implication for the evaluation of intestinal metaplasia and tumors at the esophagogastric junction

BACKGROUND

Barrett esophagus (BE)/Barrett adenocarcinoma and distal gastric intestinal metaplasia (IM)/adenocarcinoma are similar histologically, but they differ in their clinical presentation, epidemiology, and pathogenesis. Differentiating BE from gastric IM and Barrett adenocarcinoma from gastric adenocarcinoma is difficult, especially when IM is short or tumors are large and involve both sides of the esophagogastric junction. Previously, the authors identified unique cytokeratin (CK) immunoreactivity patterns that were associated strongly with BE and Barrett adenocarcinoma. The specificity of CK7 and CK20 (CK7/20) expression patterns in patients with IM-associated gastric adenocarcinoma, which is distinct epidemiologically from BE/Barrett adenocarcinoma, has not been evaluated. The objective of the current study was to evaluate the CK7/20 expression patterns in noncardia, IM-associated gastric adenocarcinoma in a Chinese population with a low risk for BE and esophageal adenocarcinoma and a high risk for Helicobacter pylori infection and gastric carcinoma.

METHODS

Endoscopic biopsy specimens of gastric IM and adjacent tumor from 50 consecutive patients with advanced noncardia gastric carcinoma were immunostained for CK7 and CK20. Clinical and endoscopic features and H. pylori status were documented. Two gastrointestinal pathologists, blinded to clinical and endoscopic data, independently assessed CK7/20 immunohistochemistry.

RESULTS

H. pylori infection was present in 43 of 50 patients (86%). In the area of IM, patchy CK7 staining was seen in 9 patients (18%), and diffuse CK20 staining was seen in all 50 patients (100%). The BE CK7/20 pattern characterized by CK7 staining in superficial and deep glands and the CK20 staining in surface epithelium was not seen in any of the 50 patients. Only one patient (2%) demonstrated a CK7 positive/CK20 negative immunophenotype characteristic of Barrett adenocarcinoma. The remaining 49 patients (98%) showed non-Barrett adenocarcinoma patterns of CK7/20 staining, i.e., a CK7 positive/CK20 positive pattern was seen in 33 patients (66%), a CK7 negative/CK20 positive pattern was seen in 12 patients (24%), and a CK7 negative/CK20 negative pattern was seen in 4 patients (8%).

CONCLUSIONS

In a patient population without risk factors for the development of BE/esophageal adenocarcinoma, the CK7/20 pattern characteristic of BE was not present in gastric IM adjacent to adenocarcinoma, and the CK7/20 pattern characteristic of Barrett adenocarcinoma also was extremely rare. These results support the hypothesis that, despite the presence of intestinalized mucosa in both disorders, BE/Barrett adenocarcinoma and gastric IM/adenocarcinoma are two distinct clinical entities with unique demographic, clinical, and CK immunophenotypic findings. These results may have application to the evaluation of patients with IM and adenocarcinoma arising at the esophagogastric junction.