Epithelial molecular markers in the peripheral blood of patients with colorectal cancer

The ATF2/miR-3913-5p/CREB5 axis is involved in the cell proliferation and metastasis of colorectal cancer

Various miRNAs have been shown to participate in the tumor progression and development of colorectal cancer (CRC). However, the role of miR-3913-5p in CRC are yet to be clearly defined. In the present study, we determine that miR-3913-5p is downregulated in CRC cell lines and CRC tissues. Exogenous miR-3913-5p expression weakens the CRC cells growth, migration and invasion. Mechanistically, miR-3913-5p directly targets the 3'UTR of CREB5. Overexpression of CREB5 reverses the suppression of CRC cells proliferation, migration and invasion induced by miR-3913-5p. Furthermore, ATF2 negatively regulates the transcription of miR-3913-5p by binding to its promoter. CREB5 can cooperate with ATF2. CREB5 is required for ATF2 in regulating miR-3913-5p. Finally, inverse correlations can be found between the expressions of miR-3913-5p and CREB5 or ATF2 in CRC tissues. Thus, a plausible mechanism of ATF2/miR-3913-5p/CREB5 axis regulating CRC progression is elucidated. Our findings suggest that miR-3913-5p functions as a tumor suppressor in CRC. ATF2/miR-3913-5p/CREB5 axis might be a potential therapeutic target against CRC progression.

A Novel DNA Aptamer Targeting S100P Induces Antitumor Effects in Colorectal Cancer Cells

Colorectal cancer (CRC) is a prevalent malignancy with poor prognosis and survival. As a Ca2+ binding protein, S100P plays a role in calcium-dependent signal transduction pathways that involve in diverse biological processes. Our previous studies have shown that S100P is overexpressed in CRC tissues and regulates cell growth, invasion, and metastasis in CRC. Therefore, S100P is expected to be an effective target for CRC therapy. Aptamers are short single-stranded oligonucleotides that could serve as specific and high-affinity probes to a wide range of target molecules for therapeutic purposes. In this study, we generated a novel DNA aptamer against S100P (AptS100P-1) by way of the SELEX process and high-throughput sequencing. The binding assay showed that AptS100P-1 had a high affinity for S100P protein. Further experiments indicated that AptS100P-1 is relatively stable in a cell culture system and could be used in flow cytometry analysis, dot blot assay, and fluorescence microscopy analysis to detect S100P. Moreover, AptS100P-1 was capable of binding to cells and had an inhibitory effect on CRC cell growth in vitro and in vivo. Also, AptS100P-1 inhibited the migration and epithelial-mesenchymal transition of CRC cells expressing S100P. These results indicate a novel DNA aptamer targeting S100P, which might be a potential therapeutic strategy for targeting S100P against S100P-expressing CRC.

Evaluation of cytokeratin 19 as a prognostic tumoral and metastatic marker with focus on improved detection methods

In the last few years, there has been a growing interest in Cytokeratin 19 (CK19) studies in the cancer research field. CK19 belongs to the Type I CKs, serves as a useful research tool in prognosis, diagnosis, and management of the tumors. In this paper, we dissect the metastatic potential of CK19, its relation with cancer stem cells and retinal epithelial cells behavior, its application as a tumor marker and its role among 30 cancers such as thyroid, thoracic, lung, pancreatic, cervical, colorectal, and so forth. CK19 expressed in several cancer types because of its metastatic potential. This paper also presents modified detection methods of CK19 in disseminated tumor cells.

Emerging methods in colorectal cancer screening

Gene-specific possibilities

miR‑205‑5p/PTK7 axis is involved in the proliferation, migration and invasion of colorectal cancer cells

MicroRNAs (miRNAs) are small non‑coding RNAs, which are critical in a diverse range of biological processes, including development, differentiation, homeostasis, and in the formation of diseases by accelerating and/or inhibiting the translation of mRNAs. The present study aimed to examine the potential role of miRNA (miR)‑205‑5p in the developmental process of colorectal cancer (CRC) through protein‑tyrosine kinase 7 (PTK7). Initially, TargetScan was used to predict the miRNA target sites in the sequence of the PTK7 3'‑untranslated region. It was then found that the mRNA expression level of miR‑205‑5p was lower in CRC cells, determined using reverse transcription‑quantitative polymerase chain reaction analysis, and there was a negative correlation between miR‑205‑5p and PTK7 in CRC tissues. It was also found that miR‑205‑5p regulated the gene transcription of PTK7, determined using a luciferase reporter assay. The results of RT‑qPCR and western blot analyses in human colorectal cancer revealed that miR‑205‑5p suppressed the expression of PTK7. Finally, it was revealed that miR‑205‑5p restricted the proliferation ability of CRC cells through inhibiting PTK7, which was determined using colony forming and 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assays. miR‑205‑5p accelerated cell apoptosis through inhibiting PTK7, demonstrated using Annexin V‑FITC/propidium iodide staining. The results of a Transwell assay indicated that miR‑205‑5p inhibited the migration and invasion abilities of CRC cells through inhibiting PTK7. Therefore, miR‑205‑5p is involved in the proliferation, migration and invasion of CRC through inhibiting PTK7.

Interplay between Trx-1 and S100P promotes colorectal cancer cell epithelial-mesenchymal transition by up-regulating S100A4 through AKT activation

We previously reported a novel positive feedback loop between thioredoxin-1 (Trx-1) and S100P, which promotes the invasion and metastasis of colorectal cancer (CRC). However, the underlying molecular mechanisms remain poorly understood. In this study, we examined the roles of Trx-1 and S100P in CRC epithelial-to-mesenchymal transition (EMT) and their underlying mechanisms. We observed that knockdown of Trx-1 or S100P in SW620 cells inhibited EMT, whereas overexpression of Trx-1 or S100P in SW480 cells promoted EMT. Importantly, S100A4 and the phosphorylation of AKT were identified as potential downstream targets of Trx-1 and S100P in CRC cells. Silencing S100A4 or inhibition of AKT phosphorylation eliminated S100P- or Trx-1-mediated CRC cell EMT, migration and invasion. Moreover, inhibition of AKT activity reversed S100P- or Trx-1-induced S100A4 expression. The expression of S100A4 was higher in human CRC tissues compared with their normal counterpart tissues and was significantly correlated with lymph node metastasis and poor survival. The overexpression of S100A4 protein was also positively correlated with S100P or Trx-1 protein overexpression in our cohort of CRC tissues. In addition, overexpression of S100P reversed the Trx-1 knockdown-induced inhibition of S100A4 expression, EMT and migration and invasion in SW620 cells. The data suggest that interplay between Trx-1 and S100P promoted CRC EMT as well as migration and invasion by up-regulating S100A4 through AKT activation, thus providing further potential therapeutic targets for suppressing the EMT in metastatic CRC.

Lentivirus-mediated knockdown of M-phase phosphoprotein 8 inhibits proliferation of colon cancer cells

M-phase phosphoprotein 8 (MPP8) has been reported to be overexpressed in various human carcinoma cells and was associated with tumor malignant characters. However, its functional role in colon cancer (CRC) is still unclear. In the present study, lentivirus-mediated short hairpin RNAs were designed to silence the MPP8 gene in CRC cells including RKO and SW1116 cells. The fluorescence microscopy was used to determine the knockdown efficiency of MPP8 by observing lentivirus-mediated green fluorescent protein expression. MPP8 expression in infected RKO and SW1116 was evaluated by real-time PCR and Western blot analysis. Cell proliferation was assessed by MTT assay and colony formation. Flow cytometry was applied to measure cell cycle and apoptosis. Transwell assay was used to determine the effect of MMP8 silencing on cell migration. Our results demonstrated that loss of MPP8 inhibited cell proliferation and migration and promoted cell apoptosis. These results indicate that MPP8 plays an important role in the proliferation and metastasis of CRC cells and suggest that silencing of MPP8 may be an effective therapeutic approach for the treatment of CRC.

Thioredoxin-1 promotes colorectal cancer invasion and metastasis through crosstalk with S100P

Thioredoxin-1 (Trx-1) is a small redox-regulating protein, which plays an important role in several cellular functions. Despite recent advances in understanding the biology of Trx-1, the role of Trx-1 and its underlying signaling mechanism in colorectal cancer (CRC) metastasis have not been extensively studied. In this study, we observed that Trx-1 expression is increased in CRC tissues compared to the paired non-cancerous tissues and is significantly correlated with clinical staging, lymph node metastasis and poor survival. Overexpression of Trx-1 enhanced CRC cell invasion and metastasis in vitro and in vivo. Conversely, suppression of Trx-1 expression decreased cell invasion and metastasis in vitro and in vivo. Moreover, Trx-1 activates S100P gene transcription. S100P, in turn, promotes Trx-1 expression and nuclear localization by upregulating p-ERK1/2 and downregulating TXNIP expression. Our finding provides new insight into the mechanism of Trx-1/S100P axis in the promotion of CRC metastasis, and suggests that the Trx-1/S100P axis and their related signaling pathways could be novel targets for the treatment of metastatic CRC.

Cytokeratin 20 positive cells in blood of colorectal cancer patients as an unfavorable prognostic marker

OBJECTIVES

Cytokeratin 20 (CK20) is one of the most investigated markers for the detection of circulating colorectal cancer (CRC) cells by reverse transcription polymerase chain reaction (RT-PCR). The aim of this study was to evaluate prognostic value of RT-PCR detection of circulating CRC cells using CK20 as a marker, and to compare the value of preoperative and postoperative blood sample analysis for that purpose.

METHODS

Ribonucleic acid (RNA) was isolated from mononuclear cell fraction of blood samples taken from 95 CRC patients before and after tumor resection and from 23 healthy volunteers and assayed by real-time RT-PCR for CK20 expression.

RESULTS

In patients positive for CK20 postoperatively both progression-free survival (PFS) and overall survival were significantly shorter than in patients negative for CK20 postoperatively, while the difference between patients positive and negative for CK20 preoperatively was not statistically significant in terms of neither PFS nor overall survival.

CONCLUSION

Our results have shown prognostic value of circulating cancer cells detected in postoperative blood samples from CRC patients using CK20 as marker for RT-PCR, which has potential implications for treatment of these patients. In clinical practice, CK20 expression profile could be a factor in weighting treatment options in CRC patients. In cases where multiple treatment options are possible, patients with positive postoperative CK20 expression could be candidates to receive more aggressive treatment.

IL-8 promote carcinogenesis of primary epithelial cells from familial adenomatous polyposis

Accumulated evidences supported IL-8 play an important role during colorectal carcinogenesis. However, few direct-related evidences are available. In this paper, we found that high level of IL-8 was constitutively present both in familial adenomatous polyposis (FAP) tissue and carcinoma tissue. Using primary epithelial cells from FAP samples, we study IL-8 effect on their growth, migration, and colonies formation. The results showed that IL-8 stimulated cells proliferation, migration, and colonies formation. Furthermore, High level of CEA, CK20, and EGFR was detected after exposure to IL-8 in primary epithelial cells. In conclusion, our findings showed that IL-8 promotes the adenoma-carcinoma transition in primary epithelial cells from FAP. Targeting IL-8 at adenoma stage may prevent or reduce carcinogenesis.

Free circulating DNA as a biomarker of colorectal cancer

OBJECTIVES

The purpose of this study is to evaluate the sensitivity and specificity of free circulating DNA (FCDNA) as a biomarker in patients suffering from colorectal cancer (CRC), investigating both its prognostic value correlated with stage of disease and its potential role in early recurrence diagnosis.

METHODS

The quantification of plasma DNA was achieved through the use of real time quantitative polymerase chain reaction (PCR) amplification of the RNAse P gene. The study enrolled patients undergoing surgery for primary CRC, at different stages of disease; samples were collected before surgery and during follow-up examinations every 3 months after surgery. Data were statistically analyzed using Software Packages SPSS® for Windows.

RESULTS

FCDNA was detectable in all pre-operative samples and the mean value was 47.8 ng/mL. FCDNA values increased progressively related to UICC stage of disease, although statistical significance was demonstrated only when comparing patients by pT stage. The analysis of postoperative samples showed a significant decrease of FCDNA quantity after radical surgery and in specific cases a rise preceding disease recurrence.

CONCLUSIONS

This study shows that absolute quantification of FCDNA in CRC patients could have a prognostic value, being related to stage of disease, and could be used as potential tool for early detection of recurrences.

Overexpression of S100P promotes colorectal cancer metastasis and decreases chemosensitivity to 5-FU in vitro

S100P has been shown to be overexpressed in various cancers and to have putative involvement in the metastatic process. However, Clinical and pathological significance of S100P expression in colorectal cancer still needs to be further studied. In the present study, the method of immunohistochemistry was utilized to investigate S100P protein expression in 91 cases of colorectal cancer. Also, the influence of ectopic expression of S100P on the biologic behavior in SW480 colorectal cancer cells was studied. We found that S100P expression of colorectal cancer tissue was significantly higher than that of normal colorectal mucosal tissues. S100P expression showed to be significantly correlated with clinical staging, lymph node metastasis and recurrence. Ectopic expression of S100P promotes SW480 cancer cells migration and invasion, decreases chemosensitivity to 5-FU in vitro. These findings suggested that S100P could serve as a promising candidate for colorectal cancer marker, prognostic indicator, and therapeutic target.

Detection of cytokeratin-20-positive cells in preoperative and postoperative blood samples from colorectal cancer patients by real-time RT-PCR

BACKGROUND

Detection of circulating cancer cells by reverse transcription polymerase chain reaction (RT-PCR) has been studied as a prognostic marker in patients with colorectal cancer (CRC) but so far with conflicting results regarding specificity and prognostic value. In this study cytokeratin-20 (CK20) was evaluated by real-time RT-PCR as a marker for circulating CRC cell detection and the influence of surgical tumor resection on the presence of circulating CRC cells was analyzed.

METHODS

RNA was isolated from the mononuclear cell fraction of blood samples taken from 95 CRC patients before and after tumor resection and from 23 healthy volunteers and assayed by real-time RT-PCR for CK20 expression.

RESULTS

Among 23 healthy volunteers one was positive for CK20. Among 95 CRC patients, 25 were positive for CK20 before and 23 after surgery. Sixteen patients positive before surgery became negative after surgery, while 14 patients negative before surgery became positive after surgery. An increase in the proportion of CK20-positive samples with increasing stage of disease was observed for preoperative but not postoperative blood samples.

CONCLUSIONS

Its association with clinical stage indicates that CK20 might have prognostic value as a marker for detection of circulating CRC cells. Surgical tumor resection can both reduce and induce the presence of circulating CRC cells.

Improved real-time rt-PCR assays of two colorectal cancer peripheral blood mRNA biomarkers: a pilot study

BACKGROUND

Efficient screening for detection of colorectal cancer (CRC) at earlier stages reduces its mortality. The purpose of this study was to investigate expression of carcinoembryonic antigen (CEA) and human telomerase reverse transcriptase (hTERT) mRNA in peripheral blood of CRC patients and to present strategies for early detection screen test.

METHODS

Twenty seven patients in non-metastatic stage and 27 healthy individuals were studied. Expression of CEA, hTERT mRNA and 18srRNA (18s subunit of ribosomal RNA, as reference gene) were determined based on real-time RT-PCR on 3 µg of total RNA from blood in 3 separate vials (1 µg per vial).

RESULTS

Positive expression rate of CEA mRNA (78%) and hTERT mRNA (81%) were higher in patient group (P<0.001). These rates were meaningfully higher than the results of individual vials containing only 1 µg of total RNA. Difference between Ct values of markers with 18srRNA ΔCt) was higher in healthy group than patient one. Therefore, a ΔCt cut-off value was determined for distinguishing between true- and false-positive results. Concurrent expression of both markers was found in 67% of the patients, which was higher than healthy cases (11%). Combination of concurrent marker expression with cut-off point strategy increased specificity to 100%.

CONCLUSION

These results showed that concurrent evaluation of marker expression and performing the test on 3 µg of samples in 3 separate vials may increase specificity and sensitivity of real-time RT-PCR for early detection of non-metastatic CRC. However, more investigations with larger numbers of samples are needed to verify these results.

Noninvasive screening tests for colorectal cancer

BACKGROUND

Identifying an accurate, reliable, affordable, and acceptable noninvasive screening test for colorectal cancer (CRC) would greatly facilitate population screening.

METHODS

Published literature from 2000 through February 2012 on noninvasive CRC screening tests was identified, reviewed, and summarized.

RESULTS

The highest quality evidence for noninvasive screening exists for guaiac-based fecal occult blood tests (gFOBTs), for which the CRC-specific incidence and mortality reductions are modest. Fecal immunochemical tests (FITs) offer better sensitivity and comparable specificity. Cross-sectional studies comparing gFOBTs and FITs suggest that FITs provide higher detection of advanced neoplasia. Modeling studies favor FITs over gFOBTs with respect to effectiveness and cost-effectiveness. A myriad of studies report the performance of fecal-based and blood-based genetic and protein-based biomarkers; the studies differ in patient population assembled, marker selection, and assay methods. Several markers and panels of markers are promising, although nearly all studies focus on new markers and/or assay methods on small sets of referred patients rather than validating markers using optimal assays in a screening setting.

CONCLUSION

In the absence of long-term randomized trials, adoption of the noninvasive tests will require cross-sectional data on test characteristics obtained from the screening setting, where CRC prevalence is low and the full spectrum of colorectal findings exists, along with estimates of cumulative risks, benefits, and cost-effectiveness. Test adoption will ultimately depend on test characteristics, availability, affordability, and user appeal. There is no noninvasive substitute for the currently recommended screening tests. FITs should replace gFOBTs wherever gFOBTs are used for screening.

Detection of circulating tumor cells in peripheral blood of colorectal cancer patients without distant organ metastases

PURPOSE

Recently, the detection of circulating tumor cells (CTCs) in peripheral blood has become an important tool for the non-invasive assessment of micrometastases and to predict clinical outcome. The objective of this study was to investigate if the presence of CTCs in peripheral blood influences the prognosis in colorectal cancer (CRC) patients without distant organ metastases.

METHODS

The GCC mRNA and CK20 mRNA levels in peripheral blood and the serum levels of CEA of 92 CRC patients without distant organ metastasis were analyzed by quantitative RT-PCR and ELISA, respectively. Its associations with overall survival (OS) and disease-free survival (DFS) rates were analyzed.

RESULTS

Univariate analyses showed that lower OS and DFS rates were significantly associated with GCC and CK20 mRNA levels, the presence of lymph node metastases, the presence of mesenteric root lymph node metastases, and the presence of tumor emboli in vessels (p < 0.05), but not with CEA levels. Multivariate analyses showed a significant association between 1) OS and GCC mRNA levels and differentiation types and 2) DFS and the presence of tumor emboli in the vessels. Kaplan-Meier curves showed that DFS was significantly associated with the presence of poorly differentiated cells, the presence of mesenteric root lymph node metastases having received prior chemotherapy, and the presence of tumor emboli in vessels.

CONCLUSION

The detection of CTCs in peripheral blood may be useful for the prediction of clinical outcome in CRC patients without distant organ metastases.

Improving colorectal cancer management: the potential of proteomics

Colorectal cancer (CRC) is the third most common cancer worldwide. Successful treatment is heavily dependent on tumor stage at the time of detection, but unfortunately CRC is often only detected in advanced stages. New biomarkers in the form of genes or proteins that can be used for diagnosis, prognostication, follow-up, and treatment selection and monitoring could be of great benefit for the management of CRC. Furthermore, proteins could prove valuable new targets for therapy. Therefore, clinical proteomics has gained a lot of scientific interest in this regard. To get an overall insight into the extent to which this research has contributed to a better management of CRC, we give a comprehensive overview of the results of proteomics research on CRC, focusing on expression proteomics, in other words, protein profiling studies. Furthermore, we evaluate the potential of the discriminating proteins identified in this research for clinical use as biomarkers for (early) diagnosis, prognosis and follow-up of CRC or as targets for new therapeutic regimens.

Influence of surgical manipulation and surgical modality on the molecular detection of circulating tumor cells from colorectal cancer

Purpose

The aim of this study was to evaluate the relationship between the detection of circulating tumor cell molecular markers from localized colorectal cancer and the time-course of a surgical manipulation or surgical modality.

Methods

From January 2010 to June 2010, samples from the peripheral blood and the inferior mesenteric vein were collected from 42 patients with cancer of the sigmoid colon or rectum. Pre-operative, intra-operative (both pre-mobilization and post-mobilization), and post-operative samples were collected. We examined carcinoembryonic antigen (CEA) mRNA and cytokeratin-20 (CK20) mRNA by real-time reverse-transcriptase polymerase chain reaction. Changes in mRNA detection rates were analyzed according to the time of blood sample collection, the surgical modality, and patient clinicopathological features.

Results

mRNA expression rates before surgical resection did not differ between blood samples from the peripheral and inferior mesenteric veins. The detection rate for CEA and CK20 mRNA showed a tendency to increase after operative mobilization of the cancer-bearing bowel segment. Furthermore, the cumulative detection rates for CEA and CK20 mRNA increased significantly over the course of surgery (pre-mobilization vs. post-mobilization). The cumulative detection rate decreased significantly after surgical resection compared with the pre-operative rates. However, no significant difference was observed in the detection rates between different surgical modalities (laparoscopy vs. open surgery).

Conclusion

The results of this study suggest that surgical manipulation has a negative influence on the dissemination of circulating tumor cells during operations on localized colorectal cancer. However, the type of surgical technique did not affect circulating tumor cells.

CK19, CK20, EGFR and HER2 status of circulating tumor cells in patients with breast cancer

AIMS AND BACKGROUND

The major cause of death in breast cancer patients is metastasis. Various biomarkers have been used for the early detection of circulating tumor cells in the peripheral blood of breast cancer patients. The aims of the current study were to analyze circulating tumor cells in the blood of breast cancer patients by investigating EGFR, CK19, CK20 and HER2 expression profiles and to evaluate their prognostic importance.

METHODS

CK19, CK20 and EGFR gene expression profiles were evaluated in the blood samples of 84 female patients with primary invasive ductal breast cancer and 20 healthy female volunteers using SYBR green-based real-time qPCR assays. HER2 expression analyses were conducted in 46 patients who had an HER2-positive primary tumor and in 30 healthy women to determine the cutoff level of positivity.

RESULTS

The positive rates of CK20, EGFR, CK19 and HER2 mRNA expression in the peripheral blood were 28.57% (24/84), 20.23% (17/84), 5.95% (5/84) and 2.17% (1/46), respectively. The high positive ratio of CK20 mRNA expression in the peripheral blood of breast cancer was identified for the first time in the current study. Significant differences were identified in CK20 expression status and several clinical parameters related with aggressiveness of tumors using a binary logistic regression analysis. Higher CK20-positive levels were observed in patients who had lymph node metastasis and advanced-grade primary tumors, which were estrogen receptor-negative. We have demonstrated that CK20 may be a novel biomarker that is useful to identify circulating tumor cells and predict breast cancer progression.

CONCLUSIONS

The results suggest that the investigation of CK20 mRNA with other biomarkers in the peripheral blood of breast cancer patients may be useful to monitor the presence of disseminated tumor cells in the blood circulation and to predict the prognosis of breast cancer.

Free peritoneal tumor cells detection in gastric and colorectal cancer patients

BACKGROUND

Free peritoneal tumor cells (FPTC) derive from the detachment of primary cancer and may result in peritoneal carcinomatosis. Since peritoneal lavage cytology has low sensitivity in detecting FPTC, our aim was to estimate the clinical relevance of FPTC detected using an approach based on multiple molecular techniques.

MATERIALS AND METHODS

Samples of peritoneal lavage were collected from 27 gastric and 48 colorectal cancer patients. FPTC recovery and detection from peritoneal washes was performed by cytological examination and immunomagnetic enrichment for epithelial cells followed by immunofluorescence analysis for epithelial marker EpCAM/CD326 and carcinoembryonic antigen (CEA). CEA and CK20 mRNA levels were quantified using a real-time qRT-PCR system.

RESULTS

For gastric carcinoma the FPTC positivity rate acquired by cytology, immunofluorescence and qRT-PCR was 14.8%, 14.8%, and 78% and for colorectal carcinoma was 0%, 17%, and 42%, respectively. qRT-PCR positivity was correlated with a poor cancer-specific survival and time-to-recurrence rates in both gastric and colorectal carcinoma.

CONCLUSIONS

Epithelial immunoenrichment and immunofluorescence analysis allows unequivocal identification of the FPTC. The real time qRT-PCR showed higher sensitivity for the detection of CEA and CK20 mRNA levels and confirmed its prognostic value in gastrointestinal cancers.

Prognostic relevance of circulating CK19 mRNA in advanced malignant biliary tract diseases

AIM: To determine the role of circulating tumor cells (CTCs) in prediction of the overall survival of patients with advanced malignant biliary tract obstruction.

METHODS: We investigated the prognostic value of CTCs by examining two markers, cytokeratin (CK) 19 and human telomerase reverse transcriptase (hTERT) mRNA, in 40 patients diagnosed with advanced malignant biliary tract diseases. Quantitative real-time reverse transcription polymerase chain reaction was used to detect CK19 and hTERT mRNA in the peripheral blood of these patients. Overall survival was analyzed using the Kaplan-Meier method and Cox regression modeling.

RESULTS: Positive CK19 and hTERT mRNA expression was detected in 45% and 60%, respectively, of the 40 patients. Univariable analysis indicated that positive CK19 mRNA expression was significantly associated with worse overall survival (P = 0.009). Multivariable analysis determined that positive CK19 mRNA expression, patient’s age and serum bilirubin were each independently associated with overall survival.

CONCLUSION: CK19 mRNA expression levels in peripheral blood appear to provide a valuable marker to predict the overall survival of patients with advanced malignant biliary tract obstruction.

Molecular tests for colorectal cancer screening

Detecting and removing high-risk adenomas and early colorectal cancer (CRC) can reduce mortality of this disease. The noninvasive fecal occult blood test (FOBT; guaiac-based or immunochemical) is widely used in screening programs and although effective, it leaves room for improvement in terms of test accuracy. Molecular tests are expected to be more sensitive, specific and informative than current detection tests, and are promising future tools for CRC screening. This review provides an overview of the performances of DNA, RNA, and protein markers for CRC detection in stool and blood. Most emphasis currently is on DNA and protein markers. Among DNA markers there is trend to move away from mutation markers in favor of methylation markers. The recent boost in proteomics research leads to many new candidate protein markers. Usually in small series, some markers show better performance than the present FOBT. Evaluation in large well-controlled randomized trials is the next step needed to take molecular markers for CRC screening to the next level and warrant implementation in a screening setting.

Targeting S100P inhibits colon cancer growth and metastasis by Lentivirus-mediated RNA interference and proteomic analysis

S100P was recently found to be overexpressed in a variety of cancers and is considered a potential target for cancer therapy, but the functional role or mechanism of action of S100P in colon cancer is not fully understood. In the present study, we knocked down the gene expression of S100P in colon cancer cells using lentivirus-mediated RNA interference. This step resulted in significant inhibition of cancer cell growth, migration and invasion in vitro and tumor growth and liver metastasis in vivo. Moreover, S100P downstream target proteins were identified by proteomic analysis in colon cancer DLD-1 cells with deletion of S100P. Knockdown of S100P led to downregulation of thioredoxin 1 and β-tubulin and upregulation of Rho guanosine diphosphate (GDP) dissociation inhibitor α (RhoGDIA), all potential therapeutic targets in cancer. Taken together, these findings suggest that S100P plays an important role in colon tumorigenesis and metastasis, and the comprehensive and comparative analyses of proteins associated with S100P could contribute to understanding the downstream signal cascade of S100P, leading to tumorigenesis and metastasis.

Multiplex RT-PCR-based detections of CEA, CK20 and EGFR in colorectal cancer patients

AIM: To develop a multiplex reverse transcription polymerase chain reaction (RT-PCR) method detecting circulating tumor cells in the peripheral blood of colorectal cancer (CRC) patients.

METHODS: Peripheral blood samples were collected from 88 CRC patients and 40 healthy individuals from the blood donors’ clinic and subsequently analyzed by multiplex RT-RCR for the expression of carcinoembryonic antigen (CEA), cytokeratin 20 (CK20) and epidermal growth factor receptor (EGFR) mRNA. The analysis involved determining the detection rates of CEA, CK20 and EGFR transcripts vs disease stage and overall survival. Median follow-up period was 19 mo (range 8-28 mo).

RESULTS: Rates of CEA, CK20 and EGFR detection in CRC patients were 95.5%, 78.4% and 19.3%, respectively. CEA transcripts were detected in 3 healthy volunteer samples (7.5%), whereas all control samples were tested negative for CK20 and EGFR transcripts. The increasing number of positive detections for CEA, CK20 and EGFR transcripts in each blood sample was positively correlated with Astler-Coller disease stage (P < 0.001) and preoperative serum levels of CEA (P = 0.029) in CRC patients. Data analysis using Kaplan-Meier estimator documented significant differences in the overall survival of the different CRC patient groups as formed according to the increasing number of positivity for CEA, CK20 and EGFR transcripts.

CONCLUSION: These data suggest that multiplex RT-PCR assay can provide useful information concerning disease stage and overall survival of CRC patients.

Up-regulation and clinical relevance of novel helicase homologue DHX32 in colorectal cancer

Background

This study aimed to find novel biomarkers for colorectal cancer.

Methods

Fluorescent mRNA differential display PCR (DD-PCR) was used to screen the genes differentially expressed in colorectal cancer tissues and their adjacent tissues. The differentially expressed genes were confirmed by real-time PCR and then their clinical relevance (such as association with tumor location and lymph gland metastasis) was further investigated.

Results

We identified by DD-PCR a novel RNA helicase, DHX32, which showed higher expression in colorectal cancer tissues than their adjacent tissues, and this result was confirmed by real time RT-PCR. In addition, we found that the level of DHX32 gene expression in colorectal cancer was significantly associated with cancer location, lymph gland metastasis, cancer nodal status, differentiation grade, and Dukes, stage.

Conclusion

DHX32 may play an important role in the development of colorectal cancer and could serve as a novel biomarker for colorectal cancer after additional investigation.

Circulating tumour cells during laparoscopic and open surgery for primary colonic cancer in portal and peripheral blood

BACKGROUND

The objective of this study was to detect and quantify circulating tumour cells (CTC) in peripheral and portal blood of patients who had open or laparoscopic surgery for primary colonic cancer.

METHODS

Patients in the laparoscopic-group were operated on in a medial to lateral approach ("vessels first"), in the open-group a lateral to medial approach was applied. The enumeration of CTC was performed with the CellSearch System. Intra-operative samples were taken paired-wise (from peripheral and portal circulation) directly after entering the abdominal cavity (T1), after mobilisation of the tumour baring segment (T2), and after tumour resection (T3). Ploidy of both the CTC and tissue of the primary tumour was determined for chromosome 1, 7, 8 and 17.

RESULTS

Thirty-one patients were included; 18 patients had open surgery, 13 patients were operated on laparoscopically. The percentage of samples with CTC at T1 was 7% in peripheral blood and 54% in portal blood (p=0.002). At T2, 4% and 31% respectively (p=0.031). And at T3, 4% and 26% respectively (p=0.125). The cumulative percentage of samples with CTC was significantly higher during open surgery as compared to the laparoscopic approach. Both the CTC and tissue of the primary tumour were diploid for chromosome 1, 7, 8 and 17.

CONCLUSION

The detection rate and quantity of CTC is significantly increased intra-operatively and is significantly higher in portal blood compared to peripheral blood. Significantly less CTC were detected during laparoscopic surgery probably as result of the medial to lateral approach.

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. The conventional use of total mesorectal excision and the integration with radiochemotherapy, better if preoperatively, are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

Persistent presence of postoperative circulating tumor cells is a poor prognostic factor for patients with stage I-III colorectal cancer after curative resection

AIM

To detect pre- and postoperative circulating tumor cells (CTCs) in stage I-III colorectal cancer (CRC) patients undergoing curative resection and so identify a subgroup of patients who are at high risk for relapse.

METHODS

Four mRNA molecular markers including human telomerase reverse transcriptase, cytokeratin-19, cytokeratin-20, and carcinoembryonic antigen mRNA were used to detect CTCs in 438 CRC patients underwent curative resection.

RESULTS

Out of 438 patients, 80 CRC patients were classified to preoperative (-)/postoperative (-), 221 patients were preoperative (+)/postoperative (-), while 137 patients were preoperative (+)/postoperative (+). Univariately, postoperative relapse was significantly correlated with depth of invasion (P = 0.032), lymph node metastasis (P < 0.001), vascular invasion (P = 0.001), perineural invasion (P = 0.013), and persistent presence of CTCs (P < 0.001). Using a multivariate proportional hazards regression analysis, the presence of lymph node metastasis (P = 0.012; HR, 7.652; 95% CI: 4.162-14.827), vascular invasion (P = 0.033; HR, 4.360; 95% CI: 2.793-10.847), and the persistent presence of CTCs (P < 0.001; HR, 29.486; 95% CI: 10.281-87.792) were demonstrated to be independent predictors for postoperative relapse. Combination of these three independent predictors showed that patients with any one positive predictor had a hazard ratio of sevenfold to develop postoperative relapse (P < 0.001; HR, 7.064; 95% CI: 4.354-11.464). Furthermore, the persistent presence of CTCs was strongly correlated with poorer relapse-free survival rates (all P < 0.001).

CONCLUSION

The promising results of this study suggest that persistent presence of postoperative CTCs may be a crucial prognostic factor adjuvant to conventional tumor markers in CRC patients who have undergone curative resection. Identification of these high-risk patients of persistent CTCs positivity is important and thus could help to define patients for adjuvant therapy with this tumor entity.

Free circulating DNA as possible tumour marker in colorectal cancer

AIM OF THE STUDY

The purpose of this study is to evaluate the sensitivity and specificity of free circulating DNA (CFDNA) as a potential tumour marker in patients suffering from colorectal cancer (CRC).

MATERIALS AND METHODS

The quantification of plasma DNA was determined through the use of real-time quantitative polymerase chain reaction (PCR) amplification of the RNAse P gene. We studied patients undergoing surgery for primary CRC, at different stages of disease and a cohort of comparable healthy donors. Data were statistically analysed using Student's t-test.

RESULTS

The mean DNA index of the tumour samples was 4771 ng/ml, about 50 times higher in comparison with healthy donors (mean value 0.85 ng/ml). In contrast the carcinoembryonic antigen (CEA) value of these patients was altered in only 47% of cases.

CONCLUSION

This study shows that circulating free DNA levels in plasma of patients with CRC are significantly higher compared to healthy subjects, and suggest a new, non-invasive, approach for colon cancer detection and to identify high risk individuals for CRC screening.