Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer

BACKGROUND

Circulating microRNAs (miRNAs) are attracting major interest as potential non-invasive biomarkers for colorectal cancer (CRC). This study aimed to identify a novel serum miRNA biomarker for the early detection and/or evaluating prognosis of CRC patients.

PATIENTS AND METHODS

Comprehensive miRNA array analysis was carried out using serum samples from patients with colorectal neoplasia and healthy controls. Next, to verify whether the candidate miRNA possessed a secretory potential, we screened miRNA expression levels in culture medium from 2 CRC cell lines, followed by serum analysis from 12 stage IV CRC, 12 adenoma, and 12 control subjects. Thereafter, we validated expression of candidate miRNAs in 179 primary CRC tissues, as well as serum samples from an independent cohort of 211 CRCs, 56 adenomas, and 57 control subjects.

RESULTS

Through microarray analysis, we identified significantly higher levels of miRNA-1290 (miR-1290) in serum from patients with colorectal adenomas and cancers. We verified miR-1290 overexpression in serum of CRC patients in a training cohort. In the validation cohort, serum miR-1290 levels were significantly up-regulated in patients with colorectal adenomas (P < 0.0001) and cancers (P < 0.0001). Serum miR-1290 levels could robustly distinguish adenoma [area under the curve (AUC) = 0.718] and CRC patients (AUC = 0.830) from normal subjects. High miR-1290 expression in serum and tissue was significantly associated with tumor aggressiveness and poor prognosis. Moreover, serum miR-1290 levels were an independent prognostic factor [hazard ratio (HR) = 4.51; 95% confidence interval (CI) = 1.23-23.69; P = 0.0096] and an independent predictor for tumor recurrence (hazard ratio = 3.92; 95% confidence interval = 1.11-25.14; P = 0.032) in CRC.

CONCLUSIONS

Serum miR-1290 is a novel biomarker for early detection, recurrence, and prognosis in CRC.

A report from the 2013 international symposium: the evaluation of the effects of low-dose radiation exposure in the life span study of atomic bomb survivors and other similar studies

The RERF International Low-Dose Symposium was held on 5-6 December 2013 at the RERF campus in Hiroshima, Japan, to discuss the issues facing the Life Span Study (LSS) and other low-dose studies. Topics included the current status of low-dose risk detection, strategies for low-dose epidemiological and statistical research, methods to improve communication between epidemiologists and biologists, and the current status of radiological studies and tools. Key points made by the participants included the necessity of pooling materials over multiple studies to gain greater insight where data from single studies are insufficient; generating models that reflect epidemiological, statistical, and biological principles simultaneously; understanding confounders and effect modifiers in the current data; and taking into consideration less studied factors such as the impact of dose rate. It is the hope of all participants that this symposium be used as a trigger for further studies, especially those using pooled data, in order to reach a greater understanding of the health effects of low-dose radiation.

Tropomyosin-related receptor kinase B at the invasive front and tumour cell dedifferentiation in gastric cancer

Background:

Tropomyosin-related receptor kinase B (TrkB) promotes proliferation and invasion, relating to poor prognosis of various malignancies. We examined the role of TrkB at the invasive front of gastric cancer (GC) and its association with tumour cell dedifferentiation and tumour budding.

Methods:

Immunoreactive TrkB was evaluated at the tumour centre and margin using whole-tissue sections of 320 GC patients. Tumour cell dedifferentiation was defined as higher histologic grade at the tumour margin than the surface or tumour centre. Tumour budding was also scored on cytokeratin-stained sections.

Results:

Sixty-five patients (20%) showed higher TrkB expression at the invasive front (TrkB expression was higher at the tumour margin than tumour centre). It was significantly associated with several aggressive phenotypes in the full cohort (n=320). It showed a prognostic significance in test subgroup (n=98) and was identified as an independent prognostic factor (HR=2.09; 95% CI: 1.26–3.53) by multivariate analysis in validation subgroup (n=222). Twenty-one patients showed tumour cell dedifferentiation. In predominantly differentiated tumour, higher TrkB at the invasive front was significantly associated with tumour budding rather than tumour cell dedifferentiation.

Conclusions:

Assessment of immunoreactive TrkB at the invasive front by whole-tissue sections provides prognostic information for GC patients.

Evaluation of serum CXCL5 as a serum marker for prognosis of colorectal cancer patients

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Background: CXCL5 is known as CXC chemokine which promotes angiogenesis related to cancer. However, the function of serum level of CXCL5 (sCXCL5) has not been fully studied in colorectal cancer. The purpose of this study was to evaluate the relationships between preoperative sCXCL5 and clinicopathological features and prognosis in colorectal cancer.

Methods: This was a single-institution, retrospective study. Preoperative serum samples of 250 colorectal cancer patients (between 1998 and 2007, median age: 65.3 years, male 159/female 91) were available for the study, and 33 normal serum was examined and used as a control. sCXCL5 level was assayed using a commercially available enzyme-linked immunosorbent assay kit, and analyzed statistically.

Results: Mean level of sCXCL5 was significantly higher in colorectal cancer patients than in control group (p=0.013). Patients with liver metastases had significantly higher sCXCL5 level than those without metastases (p=0.0086), and in logistic analysis, sCXCL5 was an independent marker for predicting liver metastasis (p=0.040). Overall survival of patients with elevated sCXCL5 level was significantly worse than those with lower sCXCL5 (p=0.0006).

Conclusions: Preoperative sCXCL5 level was increased in colorectal cancer patients compared to in healthy volunteer and elevated sCXCL5 was correlated with liver metastasis and poor prognosis for overall survival in colorectal cancer patients. Elevated sCXCL5 has been proposed as a useful predictive marker for liver metastasis and overall survival in colorectal cancer.

No significant financial relationships to disclose.

Use of serum CXCL16 to predict liver metastasis and prognosis in colorectal cancer patients

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Background: Colorectal cancer (CRC) is one of the major causes of cancer death worldwide. In CRC, serum levels of CEA have become well-established prognostic indicators. However, it is not generally accepted as optimal in its prognostic power. The aim of this study was to identify novel and reliable serum prognostic markers.

Methods: We performed cytokine array to identify novel prognostic serum marker, and CXCL16 was selected. To investigate the relationships between sCXCL16 and clinicopathological findings including survival, the serum levels of CXCL16 in 237 CRC patients and 20 normal volunteers were assessed by enzyme-linked immunosorbent assay. Furthermore, we investigated proliferation, invasion and wound healing assay to investigate the biological role of CXCL16 to colon cancer cell by recombinant CXCL16 exposing to HT-29.

Results: The mean sCXCL16 concentration in patients was significantly higher than that in normal volunteers (p<0.0001). In addition, sCXCL16 levels increased significantly in accordance with the progression of UICC stage classification (p < 0.05). In clinicopathologic findings, sCXCL16 was significantly associated with the presence of lymph node (p=0.019) and the presence of liver metastases (p=0.011). Elevated sCXCL16 level demonstrated a significant association with poor survival, and was an independent risk factor for poor survival. Furthermore, sCXCL16 was an independent marker for predicting liver metastasis (logistic analysis; p=0.0015). In vitro, recombinant CXCL16 promoted epithelial mesencymal transition (EMT) phenotype characterized by impaired E-cadherin and induction of Vimentin. In addition, CXCL16 promoted cell growth, migration and invasion.

Conclusions: Our data demonstrate that preoperative sCXCL16 level increased in colorectal cancer patients, and that sCXCL16 correlated with liver metastasis, and is an independent prognostic factor for overall survival. Elevated CXCL16 has been proposed as a useful predictive marker for liver metastasis and overall survival in CRC. In vitro, CXCL16/CXCR6 axis might play an importance role in mediating cell survival, migration and invasion by EMT in CRC cell.

No significant financial relationships to disclose.

Use of co-expression of HGF and c-Met to predict peritoneal dissemination established by autocrine HGF/c-Met signaling in gastric cancer

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Background: Epithelial mesencymal transition (EMT) promotes facilitates migration and invasion of epithelial tumour cells. EMT is induced by growth factors implicated in theses process such as hepatocyte growth factor (HGF). Our aim of this study is whether HGF/c-Met pathway is associated with metastasis of gastric cancer (GC), especially in peritoneal dissemination (PD).

Methods: HGF and c-Met expression and EMT related molecules were evaluated using real-time PCR and immunohistochemistry in GC tissues. The role of HGF/c-Met pathway for EMT and anoikis was determined and c-Met TKI (SU11274) was tested for their ability to block HGF-induced biological effects in vitro and vivo.

Results: In HGF(-)c-Met(+) GC cells,recombinant HGF promoted EMT phenotype characterized by morphology, impaired E-cadherin and induction of Vimentin. HGF promoted cell growth, invasiveness, migration ability and inhibition of anoikis. SU11274 blocked HGF-induced EMT and the biological effects in vitro. In contrast of HGF(+)c-Met(+) GC cells, HGF exposure was not affected biological outcome of EMT and anoikis but SU11274 blocked biological effect as same as in HGF(-)c-Met(+) GC cells. In vivo, HGF(+)c-Met(+) GC cell line only established PD and SU11274 intraperitoneally caused an inhibition of PD growth. Clinically, HGF expression was significantly positive correlated with c-Met expression in GC specimens. Increased HGF and c-Met demonstrated a significantly associated with poor prognosis and can predict PD, respectively. Furthermore, HGF was one of the independent factors for predicting PD. Immunohistochemical analysis showed HGF and c-Met were predominantly co-expressed in cancer cell of both primary GC and PD.

Conclusions: We have demonstrated that HGF/c-Met pathway as an inducer of EMT and anoikis inhibition in GC cell. Co-expression of HGF and c-Met implicates its potential to promote PD in GC. Blocking the autocrine HGF/c-Met pathway may be clinically useful for the treatment of PD in GC.

No significant financial relationships to disclose.

Clinical significance of CD133 and hypoxia inducible factor-1α gene expression in rectal cancer after preoperative chemoradiotherapy

AIMS

The mechanism of distant recurrence in rectal cancer after preoperative chemoradiotherapy (CRT) has yet to be fully elucidated. Further improvements in survival rates cannot be achieved without decreasing distant recurrence after preoperative CRT. Recently, it was reported that hypoxic conditions were correlated with cancer stem cell generation. Therefore, we investigated the correlation between the expression of CD133 and hypoxia inducible factor-1α (HIF-1α), and their association with clinical outcome.

MATERIALS AND METHODS

Fifty-two patients with rectal cancer underwent preoperative CRT. Residual cancer cells after CRT were obtained from formalin-fixed paraffin-embedded specimens using micro-dissection. The expression levels of CD133 (PROM1) and HIF-1α genes were measured using real-time reverse transcription polymerase chain reaction. The correlation between expression and irradiation was evaluated using colon cancer cell lines. Immunohistochemical staining of these proteins after CRT was also investigated.

RESULTS

We observed a significant inverse correlation between the gene expression of CD133 (PROM1) and HIF-1α genes in residual cancer cells after CRT. Elevated CD133 gene expression was associated with distant recurrence and poor recurrence-free survival. Elevated HIF-1α gene expression was associated with poor overall survival. In vitro, the change in gene expression levels after irradiation showed inverse patterns. Immunohistochemical analyses showed that residual cancer cells strongly expressed CD133 and lacked HIF-1α expression.

CONCLUSION

Our results suggest that CD133 and HIF-1α expression is associated with tumour re-growth and distant recurrence after CRT. These results may assist in clarifying the development of future cancer therapeutics in rectal cancer patients undergoing preoperative CRT.

Gene expression profiles of epidermal growth factor receptor, vascular endothelial growth factor and hypoxia-inducible factor-1 with special reference to local responsiveness to neoadjuvant chemoradiotherapy and disease recurrence after rectal cancer surgery

AIMS

To establish a causal relationship between the gene expression profiles of angiogenetic molecular markers, including epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1), in rectal cancer and the local responsiveness to neoadjuvant chemoradiotherapy and subsequent disease recurrence.

MATERIALS AND METHODS

We examined the pre-treatment tumour biopsies (n=40) obtained from patients with rectal adenocarcinoma (clinical International Union Against Cancer stage ll/III) who were scheduled to receive neoadjuvant 5-fluorouracil-based chemoradiotherapy for EGFR, VEGF and HIF-1 expression by quantitative real-time polymerase chain reaction.

RESULTS

Responders (patients with significant tumour regression, i.e. pathological grades 2/3) showed significantly lower VEGF, HIF-1 and EGFR gene expression levels than the non-responders (patients with insignificant tumour regression, i.e. pathological grades 0/1) in the pre-treatment tumour biopsies. The elevated expression level of each gene could predict patients with a low response to chemoradiation. During the median follow-up of all patients (41 months; 95% confidence interval 28-60 months), 6/40 (15%) developed disease recurrence. Although local responsiveness to neoadjuvant chemoradiotherapy was associated with neither local nor systemic disease recurrence, lymph node metastasis and an elevated VEGF gene expression level were independent predictors of systemic disease recurrence. The 3-year disease-free survival rates of the patients with lower VEGF or EGFR expression levels were significantly lower than those of patients with higher VEGF or EGFR expression levels.

CONCLUSIONS

Analysing VEGF expression levels in rectal cancer may be of benefit in estimating the effects of neoadjuvant chemoradiotherapy and in predicting systemic recurrence after rectal cancer surgery.

Evaultion of CD133, VEGF, or EGFR as predictive markers of distant recurrence after preoperative chemoradiotherapy in rectal cancer

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Background: CD133 has been postulated to be a colon cancer stem cells (CSCs) marker. Recent investigations suggest that CSCs might contribute to cancer recurrence and resistance to conventional therapies. This study aimed to evaluate the role of CD133 in residual cancer cells after chemoradiotherapy (CRT) for rectal cancer. Methods: Forty patients with rectal cancer underwent CRT followed by surgery. Total RNAs of rectal cancer cells before (n=30) and after (n=40) CRT were isolated. Residual cancer cells after CRT were collected from formalin-fixed paraffin-embedded (FFPE) specimens using microdissection. Intratumoral CD133, vascular endothelial growth factor (VEGF), and epidermal growth factor receptor (EGFR) were measured using real-time reverse transcription polymerase chain reaction. Immunohistochemical staining of CD133 after CRT was also investigated. Results: CD133 in residual cancer cells was higher than in stromal cells on post-CRT specimens (p<0.0001). CD133 was increased in post-CRT specimens (p=0.0184), while VEGF and EGFR were decreased during CRT (p<0.0001 and p=0.0002, respectively). There were positive correlations between CD133 and VEGF (p=0.0392) or EGFR (p<0.0001) in pre-CRT specimens. Any correlations were not found in post-CRT specimens. Patients who developed distant recurrence had a higher post-CRT CD133 compared with those patients without recurrence (p=0.0136). Elevated post-CRT CD133 was associated with poor disease free survival (p=0.0168). Immunohistochemically, cytoplasmic and apical/endoluminal membranous CD133 staining was observed in residual cancer cells after CRT. Conclusions: CD133 in residual cancer cells after CRT may indicate a treatment resistant phenotype in putative CSCs. Elevated CD133 but not VEGF or EGFR on FFPE specimens may be a predictive marker of distant recurrence and poor survival after preoperative CRT in rectal cancer.

No significant financial relationships to disclose.

Progress in updating the European Radiobiology Archives

PURPOSE

The European Radiobiology Archives (ERA), together with corresponding Japanese and American databases, hold data from nearly all experimental animal radiation biology studies carried out between 1960 and 1998, involving more than 300,000 animals. The Federal Office for Radiation Protection, together with the University of Cambridge have undertaken to transfer the existing ERA archive to a web-based database to maximize its usefulness to the scientific community and bring data coding and structure of this legacy database into congruence with currently accepted semantic standards for anatomy and pathology.

METHODS

The accuracy of the primary data input was assessed and improved. The original rodent pathology nomenclature was recoded to replace the local 'DIS-ROD' (Disease Rodent) formalism with Mouse Pathology (MPATH) and Mouse Anatomy (MA) ontology terms. A pathology panel sampled histopathological slide material and compared the original diagnoses with currently accepted diagnostic criteria.

RESULTS

The overall non-systematic error rate varied among the studies between 0.26% and 4.41%, the mean error being 1.71%. The errors found have been corrected and the studies thus controlled have been annotated. The majority of the original pathology terms have been successfully translated into a combination of MPATH and MA ontology terms.

CONCLUSIONS

ERA has the potential of becoming a world-wide radiobiological research tool for numerous applications, such as the re-analysis of existing data with new approaches in the light of new hypotheses and techniques, and using the database as an information resource for planning future animal studies. When the database is opened for new data it may be possible to offer long-term storage of data from recent and future animal studies.

Mutagenic substances in pyrolysate obtained by burning polyvinylchloride-product at 1000 degrees C

In order to detect possible mutagenic substances in pyrolysate obtained by burning polyvinyl chloride product (PVC-P) at approximately 1000 degrees C, mutagenicity of rough extracts obtained by extraction with various solvents for the products was investigated by means of reversion mutation assay using Salmonella typhimurium TA98 and TA100 with or without microsomal metabolic activation (S9 mix). Strong mutagenicity in TA98 without S9 mix was observed in acetone-extract of PVC-P. The extract was fractionated into acidic, neutral and basic by liquid-liquid distribution and the mutagenicity in TA98 without S9 mix was found in the neutral fraction. Identification of mutagenic substances in the neutral fraction from acetone extract, which showed the strongest mutagenicity, was attempted by means of thin layer chromatography and capillary gas chromatography. The results suggest that mutagenic substances from pyrolysate of PVC-P are benzanthrone and an isomer of benzo(c)cinnoline. The results also suggest that burning wastes containing plastic products is not always safe even if at 1000 degrees C and further research on the problem is necessary.

Induction of chromosome aberrations by monochromatic X-rays with resonance energy of phosphorus K-shell absorption edge

The induction of chromosome aberrations by monochromatic soft X-rays with energies corresponding to the K-shell absorption edge of phosphorus has been studied in density-inhibited mouse m5S cells. The frequency of dicentrics was markedly enhanced when the cells were irradiated with energy at the K-shell resonance peak (2.153 keV) as compared to those at below (2.146 keV) or above (2.160 keV) the peak. The quantum efficiency was calculated to be 2.7 x 10(-3) for the induction of dicentrics per photoelectric absorption of phosphorus atom in DNA, which was comparable to the known efficiencies of X- or gamma-ray-induced DNA double-strand breaks. However, comparison of the efficiencies based on the absorbed dose indicated that the magnitude of the enhancement was not due solely to the selective photoelectric absorption of the phosphorus atoms in DNA, and suggested the combined contributions of Auger electrons from phosphorus atoms within and outside the DNA molecules.

Adaptive response to chromosome damage in cultured human lymphocytes primed with low doses of X-rays

Human lymphocytes exposed to 0.02 Gy of X-rays in the G1 but not the G0 phase became less susceptible to the induction of chromosome aberrations of the chromosome type by subsequent exposure to 3 Gy of X-rays. The induction of chromatid-type aberrations was not affected by the pretreatment with the priming dose. The expression of this adaptive-type response was transitory, being maximum at 5 h, and disappeared at 9 h after the initial low-dose exposure. Cell-cycle analysis excluded the possibility of a spurious consequence of differential cell-cycle progression.