Molecular detection of circulating tumor cells in the peripheral blood of patients with colorectal cancer using RT-PCR: significance of the prediction of postoperative metastasis

BACKGROUND

Approximately 20%-45% of colorectal cancer (CRC) patients ultimately develop local recurrence or metastasis following curative surgical resection. The latter is caused by tumor cells shed from the primary carcinoma prior to or during operation, currently undetected by standard clinical staging. Fortunately, the presence of tumor cells in peripheral blood can be detected by molecular methods and is being regarded increasingly as a clinically relevant prognostic factor.

MATERIALS AND METHODS

To detect the presence of circulating tumor cells and evaluate their relationship to postoperative metastatic relapse, we simultaneously examined human telomerase reverse transcriptase (hTERT), cytokeratin-19 (CK-19), cytokeratin-20 (CK-20), and carcinoembryonic antigen (CEA) mRNA (messenger RNA) in the peripheral blood of 72 CRC patients and 30 healthy individuals. Using a reverse-transcriptase polymerase chain reaction (RT-PCR), these tumor-related mRNAs were amplified; in addition, analyses were carried out for their correlation with patients' clinicopathologic features, as well as the occurrence of postoperative metastasis.

RESULTS

In RT-PCR analysis of the peripheral blood, 69.4% (50 out of 72), 66.7% (48 out of 72), 52.8% (38 out of 72), and 72.2% (52 out of 72) of CRC patients were positive for hTERT, CK-19, CK-20, and CEA mRNA respectively. All 30 healthy individuals were negative for hTERT and CEA mRNA expression, while 2 were positive for either CK-19 mRNA or CK-20 mRNA expression. The detection of CEA mRNA was significantly correlated with depth of tumor invasion (P=0.012), vessel invasion (P=0.035), TNM stage (P<0.0001), and postoperative metastasis (P<0.0001), while positive hTERT mRNA was correlated with TNM stage (P=0.037) and CK-19 was correlated with depth of tumor invasion (P=0.039) and postoperative metastasis (P=0.017). In addition, multivariate logistic regression showed that only CEA mRNA was an independent and significant predictor of postoperative metastasis (P=0.006). Our findings suggest that CEA mRNA may be a more reliable marker than hTERT, CK-19, and CK-20 for the detection of circulating cancer cells in the peripheral blood of CRC patients.

CONCLUSIONS

Using RT-PCR for the detection of CEA mRNA is feasible and may be a promising tool for early detection of micrometastatic circulating tumor cells in CRC patients. CRC patients expressing positive CEA mRNA in peripheral blood have a significantly higher risk of postoperative metastasis. Nevertheless, confirmation of CEA mRNA as a prognostic predictive factor requires the continuation of patient follow-up.

Role of circulating tumour cells in predicting recurrence after excision of primary colorectal carcinoma

BACKGROUND

This study assessed the potential for reverse transcriptase-polymerase chain reaction (RT-PCR)-based circulating tumour cell identification to predict colorectal cancer recurrence.

METHODS

mRNA for carcinoembryonic antigen and cytokeratin 20 was identified by RT-PCR in blood from patients with colorectal cancer, before and after primary tumour resection. Cancer recurrence was assessed at follow-up, and the accuracy of RT-PCR and primary tumour lymph node positivity in predicting recurrence was estimated.

RESULTS

One hundred and ninety-six patients with colorectal cancer were studied over a median follow-up of 1393 days from surgery. Regression analysis selected 24-h post-resection RT-PCR positivity (hazard ratio for a positive test in predicting recurrence 8.66 (95 per cent confidence interval (c.i.) 3.08 to 24.33)) before lymph node involvement (hazard ratio 7.92 (95 per cent c.i. 3.26 to 19.20)). When 24-h post-resection RT-PCR was combined with lymph node positivity, the hazard ratio increased to 18.54 (95 per cent c.i. 4.01 to 85.11), attributing a 3 per cent recurrence risk to 52 per cent, and a 50 per cent recurrence risk to 48 per cent, of patients with colorectal cancer resected with curative intent.

CONCLUSION

RT-PCR positivity within 24 h of primary colorectal cancer resection is a strong predictor of colorectal cancer recurrence, and may be useful clinically.

FGFR3 mutations and a normal CK20 staining pattern define low-grade noninvasive urothelial bladder tumours

OBJECTIVES

Molecular markers superior to conventional clinicopathologic parameters are needed to predict disease courses in bladder cancer patients. In this study, we investigated four markers (Ki-67, TP53, CK20, FGFR3) in primary urothelial bladder tumours and compared them with traditional pathologic features.

METHODS

Tissue microarrays were used to analyse CK20, TP53, and Ki-67 expression immunohistochemically in 255 unselected patients. FGFR3 mutations were detected by SNaPshot analysis.

RESULTS

Abnormal CK20 expression was strongly associated with higher tumour grades and stages (p < 0.001); however, 65% of pTa tumours revealed an abnormal CK20 pattern. In the group of pTaG1 tumours, 59% presented with an abnormal CK20 pattern, whereas 82% carried the FGFR3 mutation. In the group of bladder tumours with normal CK20 pattern, the FGFR3 gene was mutated in 89%, whereas a mutated FGFR3 gene was found in only 37% of cases with abnormal CK20 expression (p < 0.001). All markers proved to be strong predictors of disease-specific survival in univariate studies. However, in multivariate analyses they were not independent from classical pathologic parameters. None of the molecular markers was significantly associated with tumour recurrence.

CONCLUSIONS

Dysregulation of CK20 expression is an early event in the carcinogenesis of papillary noninvasive bladder cancer, but occurs later than FGFR3 mutations. The group of low-grade noninvasive papillary tumours is defined by the presence of an FGFR3 mutation and a normal CK20 expression pattern.

CK7+/CK20- immunoexpression profile is typical of salivary gland neoplasia

AIMS

To evaluate cytokeratin (CK) 7/20 expression patterns in salivary gland neoplasia.

METHODS AND RESULTS

Formalin-fixed paraffin embedded tissue from 153 salivary gland tumours were evaluated for CK7/20 immunoreactivity. The tumours included pleomorphic adenoma (n = 24), myoepithelioma (n = 9), papillary cystadenoma (n = 3), oncocytoma (n = 2), adenoid cystic carcinoma (n = 22), mucoepidermoid carcinoma (n = 21), polymorphous low-grade adenocarcinoma (n = 21), carcinoma ex-pleomorphic adenoma (n = 11), acinic cell carcinoma (n = 17), epimyoepithelial carcinoma (n = 7), oncocytic carcinoma (n = 3), hyalinizing clear cell carcinoma (n = 1), papillary cystadenocarcinoma (n = 1), salivary duct carcinoma (n = 3), adenocarcinoma (not otherwise specified) (n = 4) and squamous carcinoma (n = 4). Immunohistochemical procedures were performed using monoclonal antibodies CK7 (OV-TL 12/30), CK20 (Ks 20.8) and M3515 cytokeratin (AE1/AE3) in the presence of appropriate controls. The results were expressed semiquantitatively, according to the estimated percentage of positive tumour cells: 1+, 5-25%; 2+, 26-75%; and 3+, 76-100%. All salivary gland neoplasms showed a CK7+/CK20- immunoprofile ranging from 5 to 100%. Squamous carcinoma showed negative CK7/20 immunoexpression.

CONCLUSIONS

Although the CK7/20 immunoprofile is not useful in distinguishing the various types of salivary gland neoplasms or between benign and malignant salivary gland tumours, it may facilitate differentiation of primary salivary gland neoplasia from metastatic tumours and squamous carcinoma, and the diagnosis of metastatic salivary gland tumours.

Prognostic impact of PCR-based identification of isolated tumour cells in the peritoneal lavage fluid of gastric cancer patients who underwent a curative R0 resection

Identification of cancer cells in the peritoneal cavity could influence therapy and outcome of gastric carcinoma patients. The objective of this study was to evaluate the clinical impact of the real-time quantitative polymerase chain reaction-(PCR) based identification of isolated tumour cells in the peritoneal lavage fluid of gastric carcinoma. The peritoneal lavage fluid of 116 patients with gastric cancer was sampled at laparotomy. After RNA extraction and reverse transcription, real-time quantitative PCR was performed using the primers and probes for carcinoembryonic antigen (CEA) and cytokeratin-20 (CK20). When either the CEA mRNA or CK20 mRNA level of the sample was over the cutoff value, the sample was determined to be PCR-positive. Forty-six (40%) of the 116 patients were PCR-positive and 30 (65%) of the 46 PCR-positive patients died as a result of recurrent peritoneal dissemination. The prognosis of the 46 PCR-positive patients was significantly (P<0.001) worse than that of 70 PCR-negative patients. Furthermore, in 80 of the cases with a curative R0 resection, 15 of the patients with PCR-positive findings had a significantly (P<0.001) poorer prognosis than the 65 PCR-negative patients. The prognosis of the PCR-positive patients was significantly poorer than that of the PCR-negative patients in the T3 (P<0.0001) and T4 (P=0.048) subgroups. In a multivariate analysis of the 80 cases with a curative R0 resection, the real-time quantitative RT–PCR (CEA and/or CK20) levels indicated that they were independent prognostic factors. The real-time quantitative RT–PCR analysis of the CEA and/or CK20 transcripts in the peritoneal lavage fluid is useful for predicting the peritoneal recurrence in patients who are undergoing a curative resection for gastric cancer.

Overexpression of CK20, MAP3K8 and EIF5A correlates with poor prognosis in early-onset colorectal cancer patients

PURPOSE

Due to ethnic, genetic and environmental factors, the clinical and molecular characteristics of Turkish colorectal cancer (CRC) patients are different from those of Western populations. The aim of this study was to clarify the relevant alterations of gene expression associated with colorectal carcinogenesis in early-onset patients and to identify specific biomarkers that could provide novel therapeutic molecular targets in this population.

METHODS

The expression profiles of 114 different genes were evaluated using mRNA PCR arrays in 39 tumors and 20 surgical margin tissue samples from 39 sporadic CRC patients diagnosed at less than 50 years of age.

RESULTS

The expression levels of IMPDH2, CK20, MAP3K8 and EIF5A were strongly up-regulated in CRC tissues compared with normal colorectal tissues (p < 0.05). The highly significant expression ratios of CK20, MAP3K8 and EIF5A observed in the colorectal tumors of patients predicted recurrence (p < 0.05). The expression of IMPDH2, CK20, MAP3K8 and EIF5A was significantly higher in the tumors of patients with short median survival (log-rank p value < 0.05). Progression-free survival was also significantly increased in patients with low expression of the EIF5A gene compared with those who exhibited high expression of this gene (log-rank p value < 0.05).

CONCLUSION

We demonstrated that high CK20, MAP3K8 and EIF5A expression levels were significant prognostic factors for poor overall survival in CRC patients. Further studies and validations are required; these genes may provide novel therapeutic molecular targets for CRC treatment, as well as new directions for the development of anticancer drugs.

Local immune response in bladder pain syndrome/interstitial cystitis ESSIC type 3C

INTRODUCTION AND HYPOTHESIS

Bladder pain syndrome/interstitial cystitis (BPS/IC) is identified based on subjective symptoms which lead to heterogeneous patient populations. Previous studies using gene expression arrays for BPS/IC with Hunner's lesions [European Society for the Study of Interstitial Cystitis (ESSIC) type 3C], a subtype of the condition discernible by cystoscopy, have revealed characteristic immune responses and urothelial abnormalities. This current study aimed to further characterize this subtype using a gene expression panel. We hypothesized that B-cell activation with high levels of urinary antibody concentration would be found.

METHODS

Cold-cup bladder biopsies, catheterized urine and blood were collected from 15 BPS/IC ESSIC type 3C patients, 11 non-inflammatory overactive bladder (OAB) patients and eight healthy controls. Gene expression in biopsies was quantified by real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry was performed on bladder tissue and urinary immunoglobulins G and A were quantified by enzyme-linked immunosorbent assay. Statistical analyses included the Kruskal-Wallis test for non-parametric data and post hoc tests identified differences between groups.

RESULTS

High expression of T- and B-cell markers (CTLA4, CD20, CD79A, IGH@), low expression of urothelial markers (KRT20, UPK1B, UPK3A), focal lymphoid aggregates in the submucosa and high immunoglobulin concentration in urine were found exclusively in BPS/IC ESSIC type 3C patients. Results for OAB were in intermediate ranges between the other two groups and UPK1B even reached significantly lower expression when compared to healthy controls.

CONCLUSIONS

BPS/IC ESSIC type 3C is characterized by a local adaptive immune response with elevated urinary antibody concentrations. Quantification of urinary immunoglobulin levels could be used for a non-invasive diagnosis of BPS/IC ESSIC type 3C.

Cytokeratin 17 mRNA expression has potential for diagnostic marker of oral squamous cell carcinoma

PURPOSE

Determination of marker for identification of oral squamous cell carcinoma (OSCC) is important for early diagnosis and individual therapy. Cytokeratins (CKs) like CK 19 and CK 20 are known to be useful diagnostic and prognostic markers for solid tumors. The aim of this study was to evaluate the relevance of further CKs for diagnosis of OSCC.

MATERIALS

In 10 OSCC and 5 normal mucosal samples, the expression patterns of 31 CK genes were examined by cDNA microarray in order to identify CKs with most pronounced over-expression. The results were verified for CK 17, CK 19, and CK 20 in addition to 46 OSCC samples by relative quantification (RQ) using SYBR green real-time reverse transcriptase polymerase chain reaction (RT qPCR). A correlation of the CK expressions with the tumor classification was carried out.

RESULTS

cDNA microarray analyses showed that out of all CKs, CK 17 was up-regulated strongest in OSCC compared to normal samples, and over-expression was most significantly associated with diagnosis (P = 0.002). Expression rates of CK 19 and CK 20 were not significantly different between OSCC samples and normal samples. In 56 samples analyzed by real-time RT qPCR, CK 17 was over-expressed in 53 (94.6%), CK 19 in 18 (32.1%), and CK 20 in 7 (12.5%). The over-expression of CK 17 was significantly associated with metastases of neck lymph nodes (P < 0.05). CK 19 was significantly over-expressed in T3 and T4 OSCC, in stage III and IV patients (P < 0.05), and in poorly differentiated OSCC (P < 0.03). The over-expression of CK 20 was significantly associated with metastases of neck lymph nodes (P < 0.03). Determined by RQ, the mean value of CK 17 over-expression was significantly higher than that of the other CKs (P < 0.01), and was significantly associated with T1 and T2 OSCC (P < 0.03) and with stage I and II patients (P < 0.01).

CONCLUSION

CK 19 might be linked to the clinical progression and differentiation of OSCC, and CK 20 could be associated with metastases of neck lymph nodes in OSCC. Due to the significant up-regulation and the strong over-expression, CK 17 might be the most suitable marker for diagnosis of OSCC out of the CK-family.

The value of combined use of survivin, cytokeratin 20 and mucin 7 mRNA for bladder cancer detection in voided urine

OBJECTIVES

To evaluate the value of combined use of survivin, cytokeratin (CK) 20 and mucin (MUC) 7 mRNA in comparison with voided urine cytology in the detection of bladder cancer patients.

METHODS

One hundred and fifty three patients and 20 healthy volunteers were evaluated by RT-PCR for detecting survivin, CK-20 and MUC7 mRNA in voided urine before cystoscopy. The three markers and cytology were evaluated independently or in combinations.

RESULTS

The overall sensitivity and specificity were 90.4 and 94.7% for survivin, 82.6 and 97.4% for CK-20, 62.6 and 94.7% for MUC7 and 46.0 and 100% for voided urine cytology. Combined sensitivity of voided urine cytology with the three biomarkers together was higher than either combined sensitivity of voided urine cytology with one of the biomarkers or than that of the biomarker alone.

CONCLUSIONS

Combined use of the three markers can improve the sensitivity for detecting bladder cancer.

Expression of Androgen Receptor by Fibroepithelioma of Pinkus: Evidence Supporting Classification as a Basal Cell Carcinoma Variant?

The classification of fibroepithelioma of Pinkus as basal cell carcinoma or trichoblastoma remains controversial. Immunohistochemical stains for androgen receptor may be useful in differentiating basal cell carcinoma from trichoepithelioma or trichoblastoma. We studied androgen receptor expression in 13 fibroepitheliomas of Pinkus, 11 basal cell carcinomas, 12 trichoepitheliomas, and 3 trichoblastomas. Androgen receptor expression was present in 77% (10/13) of fibroepitheliomas of Pinkus, 73% (8/11) of basal cell carcinomas, 17% (2/12) of trichoepitheliomas, and 0% (0/3) of trichoblastomas. Androgen receptor expression was significantly higher in fibroepitheliomas of Pinkus compared with trichoepitheliomas and trichoblastomas (P = .0007), but not basal cell carcinoma (P = 1.00). Tumor-associated Merkel cells, a feature of benign follicular tumors, was identified by cytokeratin 20 stains. Merkel cells were identified in 85% (11/13) of fibroepitheliomas of Pinkus, 27% (3/11) of basal cell carcinoma cases, and 73% (11/15) of benign follicular tumors. Cytokeratin 20 expression was significantly higher in fibroepithelioma of Pinkus and benign follicular tumors compared with basal cell carcinomas (P = 0.0111 and P = 0.025, respectively). No significant difference was found between fibroepitheliomas of Pinkus and trichoepitheliomas and trichoblastomas (P = 1.00). Similar to basal cell carcinomas, fibroepitheliomas of Pinkus express androgen receptors, potentially supporting classification as a basal cell carcinoma. Conversely, fibroepithelioma of Pinkus demonstrates retention of Merkel cells, a feature of benign follicular tumors. Immunophenotypic evidence for the classification of fibroepithelioma of Pinkus remains inconclusive. In small, partial biopsy specimens, coexpression of androgen receptor and cytokeratin 20 may aid in the diagnosis of fibroepithelioma of Pinkus.

Comparison of CD44 and cytokeratin 20 mRNA in voided urine samples as diagnostic tools for bladder cancer

OBJECTIVES

We evaluated the diagnostic efficacy of urinary CD44 and cytokeratin 20 (CK20) mRNA in comparison with voided urine cytology (VUC) for the detection of bladder cancer.

DESIGN AND METHODS

A total of 136 Egyptian patients provided a single voided urine sample for CD44, CK20 mRNA and VUC before cystoscopy. Of the 136 cases, 111 were histologically diagnosed as bladder cancer whereas the remaining 25 had benign urological disorders. A group of 20 healthy volunteers was also included in this study. Voided urine was centrifuged and the urine sediment was used for cytology, estimation of CD44 by ELISA and RNA extraction. CK20 mRNA was detected by conventional RT-PCR and quantitative real-time RT-PCR.

RESULTS

The best cutoff values for CD44 and relative CK20 mRNA detected by real-time RT-PCR were calculated by receiver operating characteristic curve. The positivity rates and the mean ranks for CD44 and CK20 mRNA showed significant difference among the three investigated groups (p=0.001). Quantitative real-time RT-PCR results were comparable to conventional RT-PCR for the detection of CK20 mRNA. The positivity rate of CD44 was significantly associated with schistosomiasis and urine cytology. The overall sensitivity and specificity were 52.3% and 88.9% for VUC, 63.1% and 88.9% for CD44, and 82.0% and 97.8% for CK20 mRNA. Combined sensitivity of VUC with CD44 and CK20 mRNA together (95.5%) was higher than either the combined sensitivity of VUC with CD44 (78.4%) or with CK20 mRNA (91.0%) or than that of the biomarker alone.

CONCLUSION

Urinary CD44 and CK20 mRNA had higher sensitivities compared to VUC. However, when the diagnostic efficacy was considered, CK20 mRNA by either conventional RT-PCR or real-time RT-PCR had the highest sensitivity and specificity compared to CD44 and VUC.

Regulation of ribosomal RNA synthesis in T cells: requirement for GTP and Ebp1

Mycophenolic acid (MPA) is the active metabolite of mycophenolate mofetil, an effective immunosuppressive drug. Both MPA and mycophenolate mofetil are highly specific inhibitors of guanine nucleotide synthesis and of T-cell activation. However, the mechanism by which guanine nucleotide depletion suppresses T-cell activation is unknown. Depletion of GTP inhibits ribosomal RNA synthesis in T cells by inhibiting transcription initiation factor I (TIF-IA), a GTP-binding protein that recruits RNA polymerase I to the ribosomal DNA promoter. TIF-IA-GTP binds the ErbB3-binding protein 1, and together they enhance the transcription of proliferating cell nuclear antigen (PCNA). GTP binding by TIF-IA and ErbB3-binding protein 1 phosphorylation by protein kinase C δ are both required for optimal PCNA expression. The protein kinase C inhibitor sotrastaurin markedly potentiates the inhibition of ribosomal RNA synthesis, PCNA expression, and T-cell activation induced by MPA, suggesting that the combination of the two agents are more highly effective than either alone in inducing immunosuppression.

Comparative analysis of intraperitoneal minimal free cancer cells between colorectal and gastric cancer patients using quantitative RT-PCR: possible reason for rare peritoneal recurrence in colorectal cancer

Peritoneal recurrence has a much lower incidence in colorectal cancer (CRC) patients than gastric cancer (GC) patients. The aim of this study is to clarify the reason for the rare peritoneal recurrence in CRC as compared with GC. The incidence and the abundance of free tumor cells in the peritoneal lavages from 102 CRC and 126 GC patients who underwent curative surgery were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) with carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) as genetic markers. Prognostic significance of CEA and CK20 mRNA was also compared between CRC and GC after 2 years of follow-up by Kaplan-Meyer method with overall and peritoneal recurrence-free survival as endpoints. Positivity rate and average values of CEA and CK20 mRNA in peritoneal lavages of CRC patients, which are correlated to the depth of tumor invasion (pT category), were essentially the same as those of GC cases. Overall survival was significantly (marginally) worse in CEA mRNA (CK20 mRNA)-positive CRC patients than negatives like GC. However, peritoneal recurrence-free survival was not different between CEA (CK20) mRNA-positive and -negative CRC patients, in quite contrast to GC cases. Multivariate analysis showed that CEA mRNA was an independent prognostic factor for overall survival in GC patients, but not in CRC patients. These results suggest that the rare peritoneal recurrence in CRC patients is not due to the low incidence or the small number of intraperitoneal free cancer cells, but more likely reflects due to the low-peritoneal metastatic potential of CRC cells.

Detection of cancer cells disseminated in bone marrow using real-time quantitative RT-PCR of CEA, CK19, and CK20 mRNA in patients with gastric cancer

BACKGROUND

To determine the significance of bone marrow disseminated tumor cells in gastric cancer, we investigated the mRNA expression levels of carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and cytokeratin 20 (CK20) using the real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR).

METHODS

Bone marrow samples were aspirated from the sternum at the time of surgery in 65 patients with resectable gastric cancer. Total RNA was extracted from bone marrow; and the expression levels of CEA, CK19, and CK20 mRNA were determined by RQ-PCR using an ABI PRISM 7000 and quantified against the GAPDH mRNA level.

RESULTS

The detection limits of these genes were determined in the gastric cancer cell line MKN-45 and the colon cancer cell line C-1, which had been serially diluted in peripheral blood mononuclear cells (PBMCs). A rate of 1 cancer cell/million PBMCs was obtained by detecting CEA and CK19 mRNA in MKN-45 and by detecting CK20 mRNA in C-1. In the clinical samples, only 1 of the 65 gastric cancer patients (1.5%) who had stage IV disease was positive for CEA, CK19, and CK20 mRNA; none of CEA, CK19, or CK20 mRNA was positive in the remaining 64 patients. No significant correlation was observed between disseminated cancer cells in bone marrow and clinicopathological features, including simultaneous or metachronous hepatic metastasis and patient survival.

CONCLUSION

The incidence of disseminated cancer cells in bone marrow in our study appears low, unlike that in previous reports. The significance of disseminated cancer cells in bone marrow may also be quite low in gastric cancer.

Detection of minimal gastric cancer cells in peritoneal washings by focused microarray analysis with multiple markers: clinical implications

BACKGROUND

Peritoneal cytology is an important prognostic factor of gastric cancer. However, peritoneal cytology requires great skill, which may explain its low prevalence. A reverse transcriptase-polymerase chain reaction-based assay with multiple marker genes or immunocytochemistry was assessed as an alternative method of gathering the same kind of data as cytology.

METHODS

Peritoneal washings from 179 patients with gastric cancer were analyzed by multiplex reverse transcriptase-polymerase chain reaction with 10 marker genes and subsequent hybridization to a customized oligo-nucleotide array. Results with this assay were either validated as a prognostic factor or confirmed by demonstrating the presence of cancer cells by immunocytochemical cytology.

RESULTS

Only 1 (2.2%) of 44 disease-free cases was shown to be positive by the microarray assay, whereas 13 (93%) of 14 conventional cytology-positive cases were found to be positive. This assay further detected approximately one-third of cytology-negative patients either with peritoneal recurrence (7 of 20, 35%) or with non-peritoneal recurrence (6 of 22, 27%). A high concordance between the microarray assay and immunocytochemical cytology with five antibodies against CK20, FABP1, MUC2, TFF1, and MASPIN was confirmed. The clinical outcome of the microarray assay-positive cases was poor, as was that of the cytology-positive cases.

CONCLUSIONS

Our assay, though time-consuming and requiring special equipment, demonstrated a specificity and sensitivity equal to or better than cytology in our institutes. The minimal free peritoneal cancer cells detected by the microarray assay may provide the same clinical information as larger amounts of cancer cells for patients with gastric cancer. An anti-MASPIN antibody may be helpful in peritoneal cytology of gastric cancer.

Molecular characterization of low grade and high grade bladder cancer

Background

Bladder cancer (BC) is the 9^th most common cancer diagnosis worldwide. Low grade (LG) represents 70% of all BCs, characterized by recurrence and rare ability (10–15%) to progress to high grade (HG) and invade. The remaining 30% is high grade (HG), fast invasive BC, which is resistant to therapy. Identifying biomarkers for predicting those tumors able to progress is a key goal for patient outcome improvement. This study focuses on the most promising prognostic markers.

Materials and methods

TP53 and FGFR3 mutational status, Survivin, CK19, CK20, E-cadherin and CD44 gene expression analysis were performed on 66 BCs.

Results

Survivin was found associated to tumor grade (p<0.05). Moreover, Survivin correlated with CD44 in TP53 wild type (p = 0.0242) and FGFR3 wild type (p = 0.0036) tumors. In particular the Survivin-CD44 correlation was associated to HG FGFR3 wild type BCs (p = 0.0045). Unsupervised hierarchical clustering based on gene expression data identified four distinct molecular groups reflecting the patient histology (p = 0.038).

Conclusion

We suggest Survivin, both as a biomarker associated to G3 BCs but negatively related to TP53 mutational status, and as a potential novel therapeutic target.

Serrated pathway adenocarcinomas: molecular and immunohistochemical insights into their recognition

INTRODUCTION

Colorectal adenocarcinomas (CRC) developed through serrated pathway seem to present particular behavior compared with the non-serrated ones, but recognition of them is difficult to do. The aim of our paper was to establish some criteria to facilitate their identification.

MATERIALS AND METHODS

In 170 consecutive CRCs, we performed immunohistochemical staining with Cytokeratin 7 (CK7) and Cytokeratin 20 (CK20) and also with p53 and MLH-1. At the same time, we analyzed BRAF and K-ras mutations and the microsatellite status of CRC.

RESULTS

26.47% of cases expressed CK7, and 16.47% were CK20-negative. Diffuse positivity for CK7 was associated in the proximal colon with CK20 negativity or weak positivity, BRAF mutations, lack of K-ras mutations, and p53 and MLH-1 negativity. All these cases were microsatellite-unstable and were diagnosed in stage II. Those cases from the distal colon and rectum that expressed CK7 were K-ras-mutated and had low p53 index and MLH-1 positivity, independent of the CK20 expression.

CONCLUSIONS

CK7, associated with MLH-1 and p53 expression, and also with the microsatellite status, BRAF and K-ras pattern, might be used to identify the CRC potentially going through serrated pathway. The serrated pathway adenocarcinomas of the proximal colon that do not display the morphological features of this pattern are more frequent CK7+/p53-/MLH-1-/BRAF-mutated/K-ras-wt/MSI cases, but those located in the distal colorectal segments seem to be CK7+/CK20+/p53-/MLH-1+/BRAF wt/K-ras-mutated/MSS cases.

Urinary cytokeratin 20 mRNA expression has the potential to predict recurrence in superficial transitional cell carcinoma of the bladder

Higher levels of cytokeratin 20 (CK 20) mRNA are expressed in malignant urothelial tissue compared to normal tissue. We determined the CK 20 mRNA expression in urine from patients with transitional cell carcinoma (TCC) of the bladder and assessed the biological behavior of such tumors in a 5-year follow-up. Second voided urine was preoperatively collected from 56 patients with bladder carcinoma, from 20 patients with nonmalignant urological diseases and from 40 healthy volunteers. RNA extraction from exfoliated urothelial cells was followed by quantitative real-time RT-PCR with the Light Cycler. Patients in the superficial TCC group had a median expression of 8226AU (arbitrary units) with and 1523AU without tumor recurrence (P=0.023). No such correlation was detected in the group with muscle-invasive tumors. Kaplan-Meier analysis revealed a significant difference between recurrent and nonrecurrent disease (P=0.019) in superficial but not in muscle-invasive TCC (P=0.84). CK 20 mRNA expression in urine has the potential to identify patients at risk for recurrence of noninvasive papillary urothelial tumors. It helps to categorize patients prior to TUR-B, so that the cystoscopy interval during follow-up may be extended in those with low-risk superficial TCC.

Extracutaneous Merkel cell carcinomas harbor polyomavirus DNA

Merkel cell carcinoma is a neuroendocrine tumor, with characteristic morphological and immunohistochemical features. Originally reported as primary carcinoma of skin, it has been described in numerous other sites such as lymph nodes, oral cavity, breast, vaginal walls, and salivary glands. Recent studies have revealed in cutaneous Merkel cell carcinomas a clonally integrated polyomavirus, named Merkel cell polyomavirus. The aim of the present study was to verify the presence of Merkel cell polyomavirus in 5 cases of primary Merkel cell carcinomas of lymph nodes and 1 case of parotid gland to investigate similarities or differences among Merkel cell carcinomas from various sites. Cases studied were 5 primary Merkel cell carcinomas in lymph nodes, 1 in the parotid gland, and 12 in the skin. Twelve cases of primary and metastatic small cell carcinoma of the lung were also investigated. Immunohistochemistry for keratin 20, chromogranin, synaptophysin, and thyroid transcription factor 1 was performed in all cases. Viral DNA was studied using polymerase chain reaction assay and the products evaluated in agarose gel and sequenced. Cytokeratin 20 and Merkel cell polyomavirus were detected in all cases of primary Merkel cell carcinoma irrespective of their site of origin. On the contrary, all cases of pulmonary small cell carcinoma were negative for both Merkel cell polyomavirus and cytokeratin 20. It appears that cutaneous and extracutaneous Merkel cell carcinomas share similar histologic, immunohistochemical, and molecular features. This is further evidence that Merkel cell carcinomas are a multiorgan carcinoma and that Merkel cell polyomavirus might play a role in the pathogenesis of this neoplasm.

Partially Degraded RNA from Bladder Washing is a Suitable Sample for Studying Gene Expression Profiles in Bladder Cancer

OBJECTIVES

To determine the impact of different levels of RNA degradation on gene expression measurements and to ascertain if the gene expression profile obtained from bladder washing (BW) correlates to that obtained from the related bladder tumour (BT).

METHODS

BT and BW RNAs from the same patient were heat shocked to obtain three RNA degradation states, which were compared with intact RNAs from healthy bladders by using complementary DNA (cDNA) microarrays. All samples were amplified by means of a T3N9-based transcription method. In addition, four of the differentially expressed genes in microarrays related to bladder cancer (KRT20, IGF2, GSN, and CCL2) were analyzed in 36 tumoural and 14 control BW samples by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).

RESULTS

A high percentage of overlapping differentially expressed genes were detected between BT arrays (85-91%) and between BW arrays (78-93%). Furthermore, the similarity between BW and BT arrays was relatively high and independent of the RNA degradation state (52-60%). Finally, expression differences for the four selected genes were confirmed in the vast majority of extended BW samples tested by qRT-PCR.

CONCLUSIONS

Our results showed that partially degraded RNA samples analyzed by cDNA microarrays yielded gene expression profiles comparable to those obtained using intact RNA. Moreover, BW RNA exhibited gene expression patterns similar to those identified in the BT, indicating that BW is an appropriate sample for studying gene expression profiles of BT using cDNA microarrays. In addition, qRT-PCR results further support the suitability of BW for gene expression profiling and its potential use for routine diagnostics.

Detection of epithelial cells by RT-PCR targeting CEA, CK20, and TEM-8 in colorectal carcinoma patients using OncoQuick density gradient centrifugation system

BACKGROUND

The detection of epithelial-specific mRNA correlates well with the presence of cancer cells in the peripheral blood and provides a rational explanation for subsequent metastasis.

MATERIAL AND METHODS

Forty-two, patients with colorectal cancer and 14 controls were included in our study. Peripheral blood samples were acquired at 24 h before and 48 h after laparotomy. Tissue samples were also acquired from the primary lesion. All samples were examined for the expression profile of CEA, CK20, and TEM-8.

RESULTS

Tissue samples expressed CEA in every specimen, CK20 in 30, and TEM-8 in 41. CEA and CK20 were not identified in the control blood samples while TEM-8 was detected in 4. CEA was detected in 17, CK20 in 28 and TEM-8 in 23, of the preoperative blood samples. CEA mRNA expression in preoperative blood sample and TNM stage were found independently associated with increased tumor size. Positive CEA, CK20, and TEM-8 signals were found in 25, 25, and 23 of the postoperative blood samples respectively.

CONCLUSIONS

CK20 and CEA are significantly more frequently detected in colon cancer patients than in healthy controls and can serve as markers. Cancer cell mRNA is commonly detected in the preoperative and postoperative peripheral blood samples. Tumor size was independently associated with the preoperative detection of CEA mRNA. Although TEM-8 mRNA detection in the peripheral blood showed no specificity for cancer patients or correlation with clinical stage, identification and validation of genes and proteins implicated in metastatic process needs to be further investigated.

Biopsy-derived Intestinal Epithelial Cell Cultures for Pathway-based Stratification of Patients With Inflammatory Bowel Disease

BACKGROUND

Endoplasmic reticulum [ER] stress was shown to be pivotal in the pathogenesis of inflammatory bowel disease. Despite progress in inflammatory bowel disease [IBD] drug development, not more than one-third of patients achieve steroid-free remission and mucosal healing with current therapies. Furthermore, patient stratification tools for therapy selection are lacking. We aimed to identify and quantify epithelial ER stress in a patient-specific manner in an attempt towards personalised therapy.

METHODS

A biopsy-derived intestinal epithelial cell culture system was developed and characterised. ER stress was induced by thapsigargin and quantified with a BiP enzyme-linked immunosorbent assay [ELISA] of cell lysates from 35 patients with known genotypes, who were grouped based on the number of IBD-associated ER stress and autophagy risk alleles.

RESULTS

The epithelial character of the cells was confirmed by E-cadherin, ZO-1, and MUC2 staining and CK-18, CK-20, and LGR5 gene expression. Patients with three risk alleles had higher median epithelial BiP-induction [vs untreated] levels compared with patients with one or two risk alleles [p = 0.026 and 0.043, respectively]. When autophagy risk alleles were included and patients were stratified in genetic risk quartiles, patients in Q2, Q3, and Q4 had significantly higher ER stress [BiP] when compared with Q1 [p = 0.034, 0.040, and 0.034, respectively].

CONCLUSIONS

We developed and validated an ex vivo intestinal epithelial cell culture system and showed that patients with more ER stress and autophagy risk alleles have augmented epithelial ER stress responses. We thus presented a personalised approach whereby patient-specific defects can be identified, which in turn could help in selecting tailored therapies.

Diagnostic and prognostic value of bladder cancer-related transcript markers in urine

PURPOSE

Since cytology as the current "gold standard" for noninvasive detection of bladder cancer (BCa) is characterized by a relatively low sensitivity, urinary transcript levels of survivin (SVV), Ki-67 and cytokeratin 20 (CK20) were evaluated as alternative or complementary biomarkers. Furthermore, their prognostic value was investigated.

METHODS

Voided urine samples from 105 BCa patients and 156 controls were included. Total RNA was isolated from urine pellets and reverse-transcribed into cDNA. Expression levels of SVV, Ki-67 and CK20 were determined by quantitative PCR and normalized to the housekeeping gene TBP. Diagnostic performance of transcript markers and cytology was assessed by receiver operating characteristic (ROC) curve analyses. The prognostic value of the transcript markers was calculated by Cox proportional hazards models.

RESULTS

ROC analyses resulted in AUC values between 0.71 (Ki-67) and 0.86 (CK20), indicating an appropriate diagnostic power. Using specifically defined cutoff values, the expression levels of the assessed biomarkers were significantly higher in urine specimens from BCa patients compared to control group (Mann-Whitney U test p < 0.001). Specificity ranged from 75% (SVV) to 84% (CK20) and sensitivity from 56% (Ki-67) to 87% (CK20). In combination with cytology, the sensitivity increased up to 97% (CK20). With regard to prognostic power, only SVV showed a significant, but not independent impact on the risk of recurrence (p = 0.008).

CONCLUSIONS

Quantitative assessment of tumor-related transcript markers, particularly of CK20, may serve as a noninvasive method to identify patients with BCa. Moreover, SVV appears to be useful as a marker for a high risk of recurrence.

Increased detection rate and potential prognostic impact of disseminated tumor cells in patients undergoing endorectal ultrasound for rectal cancer

BACKGROUND

Hematogenous tumor-cell dissemination during diagnostic and therapeutic procedures in patients with colorectal cancer has been demonstrated.

OBJECTIVE

The aim of this study was to investigate the extent of disseminated tumor cells in blood samples of rectal cancer patients after endorectal ultrasound and to determine its prognostic relevance.

MATERIALS AND METHODS

Peripheral venous blood samples from 45 patients with rectal cancer were taken before and after endorectal ultrasound. Blood samples were examined using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to amplify cytokeratin 20 transcripts. Overall survival of the patients was calculated by the Kaplan-Meier method.

RESULTS

Disseminated tumor cells were detected in peripheral blood samples of 17 of 45 (38%) patients before and after endorectal ultrasound. Circulating tumor cells were found in 11 of 45 (24%) patients only after endorectal ultrasound (p=0.006). There was a clear trend toward a worse prognosis in patients with tumor cells in blood samples after endorectal ultrasound, but this difference was not statistically significant.

CONCLUSION

This study demonstrates significantly increased hematogenous tumor-cell dissemination after endorectal ultrasound in rectal cancer patients. Patients with tumor cells in blood samples after endorectal ultrasound tend to have a worse prognosis. The potential prognostic impact of this finding is presently unclear and has to be further validated in larger clinical trials.

[Merkel cell carcinoma]

Merkel cell carcinoma (MCC, cutaneous neuroendocrine carcinoma) is a rare form of tumor of unclear histogenesis which predominantly occurs in elderly patients on areas exposed to the sun. A higher incidence and occurrence in younger people is predominantly found in immunosuppressed persons which is why a pathogenetic role is also attributed to immunosuppression in addition to ultraviolet (UV) radiation. Additionally, in 80% of cases clonally integrated polyomavirus (Merkel cell polyomavirus, MCPyV) could be detected. Clinically MCC represents an uncharacteristic tumor. Histopathologically, monomorphic dermal and/or subcutaneous nodes are found consisting of round or oval medium sized cells with a vesicular nucleus and sparse cytoplasm. The neoplastic cells of MCC express cytokeratin (CK) 20 with a dot-like perinuclear accentuation. In addition, pan-CK, neuroendocrine markers (e.g. chromogranin A and synaptophysin), neurofilament proteins, CD56, CD57, Bcl-2, TdT and PAX-5 are immunohistochemically positive. In most cases CM2B4, an antibody against MCPyV is also positive. Expression of p63 has been observed in some of the cases and in some studies was associated with a favorable prognosis. The markers thyroid transcription factor 1, mammalian achaete scute complex like 1, vimentin, S-100 and CK7 are not normally expressed by MCC. The prognosis is primarily dependent on tumor size and the lymph node status. The presence of intralymphatic tumor complexes is associated with a higher rate of local recurrence and lymph node metastasis. A larger number of intratumoral cytotoxic T-lymphocytes is accompanied by a favorable prognosis and the presence of > 50% of K-67+ neoplastic cells with an unfavorable prognosis. Further morphological, phenotypical and genetic factors have not yet been validated in larger cohorts with respect to the prognostic relevance.