Global histone modification of H3K27 correlates with the outcomes in patients with metachronous liver metastasis of colorectal cancer

BACKGROUND

We evaluated the methylation patterns of histone H3 lysine 27 (H3K27), H3 lysine 36 (H3K36) and the expression of H3K27 methylase EZH2 in patients with colorectal carcinomas with metachronous liver metastasis to search for biomarkers identifying these patients.

METHODS

Double 2-mm core tissue microarrays were made from 54 paraffin-embedded samples of primary colorectal adenocarcinomas and corresponding liver metastases and examined using an immunohistochemical analysis of dimethylation and trimethylation in H3K27, H3K36 and EZH2. Positive tumor cell staining for each histone modification (H-score) was used to classify patients into low- and high-staining groups, which were then examined to identify any correlations between the clinicopathological parameters and the clinical outcomes.

RESULTS

The H-scores of H3K27me2 were lower in the liver metastases than in the corresponding primary tumors, while the H-scores of H3K36me2 were higher in the liver metastases than in the corresponding primary tumors (P < 0.001). H3K27me2 in the primary tumors correlated with tumor size (P = 0.016), H3K36me2 in the primary tumors correlated with histological type (P = 0.038), and H3K36me3 in the primary tumors correlated with lymph node metastasis (P = 0.017). In addition, lower levels of H3K27me2 in the primary tumors correlated with poorer survival rates (P = 0.039). The multivariate survival analysis showed that the H3K27me2 status is an independent prognostic factor for colorectal cancer patients (P = 0.047).

CONCLUSIONS

Our findings suggest that the methylation level of H3K27me2 detected with immunohistochemistry may be an independent prognostic factor for metachronous liver metastasis of colorectal carcinomas.

REG Iα is a biomarker for predicting response to chemotherapy with S-1 plus cisplatin in patients with unresectable stage IV gastric cancer

Background:

The regenerating gene Iα (REG Iα) is involved in gastric carcinogenesis as an antiapoptotic factor. Therefore, we investigated whether REG Iα confers resistance to chemotherapeutic drugs in gastric cancer (GC) cells and whether REG Iα expression is useful for predicting the response to chemotherapy and outcome in patients with GC.

Methods:

A total of 70 patients with unresectable stage IV GC received first-line chemotherapy with S-1 and cisplatin (S-1/CDDP). The expression of REG Iα was evaluated immunohistochemically using biopsy samples obtained before chemotherapy, and its relationship to clinicopathological parameters was analysed statistically. The effects of REG Iα gene induction on resistance to 5-FU or CDDP treatment were examined by cell survival assay and flow cytometry.

Results:

Of the 70 patients with unresectable stage IV GC, 19 (27%) were positive for REG Iα expression. The expression of REG Iα was independently predictive of poorer progression-free and overall survival in such patients (hazard ratio (HR) 2.46; P=0.002 and HR 1.89; P=0.037, respectively). The gene induction of REG Iα conferred resistance to cell death induced by 5-FU or CDDP in GC cells.

Conclusion:

In patients with stage IV GC, REG Iα, which confers resistance to chemotherapeutic drugs in GC cells, is a potential biomarker for predicting resistance to S-1/CDDP treatment.

Enhancement of thermal damage in murine tumors by hydralazine-induced modification of blood flow and oxygen tension

We investigated changes in blood flow in normal muscle and in SCC-VII tumors treated by hyperthermia combined with hydralazine, to evaluate the enhancement of thermal tumor damage by hydralazine. We studied SCC-VII tumor-bearing C3H/He mice. Hydralazine was administered by intraperitoneal injection, and tumors were heated by a water bath. We measured blood flow using the laser Doppler method, and oxygen tension using polarography. The response of tumors to therapy was assessed using a growth delay analysis. In tumors, blood flow and O-2 tension significantly decreased with increasing doses of hydralazine. Compared to tumors treated by hydralazine alone or by hyperthermia alone, tumor blood flow was significantly decreased in the group treated by hyperthermia with hydralazine. In tumors treated by hyperthermia with hydralazine, blood flow was significantly decreased with increasing Hyd doses, heat durations, and temperatures. In normal muscle, no decrease in blood flow was induced by hyperthermia, hydralazine, or their combination. In tumors treated by hyperthermia (43 degrees C, 20 min) with hydralazine, a maximum additional growth delay was observed. Our results suggest that a decrease in tumor blood flow caused by hydralazine plays an important role in enhancement of the hyperthermic antitumor effect.

Generation of dyspeptic symptoms by direct acid and water infusion into the stomachs of functional dyspepsia patients and healthy subjects

BACKGROUND

The mechanisms of the development of symptoms in functional dyspepsia (FD) patients have not been fully elucidated. We previously reported that acid directly infused into the stomach causes dyspeptic symptoms in asymptomatic healthy controls (HCs); however, the response to acid infusion of FD patients was not determined.

AIM

To investigate the severity of dyspeptic symptoms induced by direct acid infusion in FD subjects and HCs.

METHODS

This was a multi-centre, cross-over, randomised, double-blind study in 23 FD subjects and 32 HCs. FD was defined using the Rome III criteria. All subjects were Helicobacter pylori negative. Each subject received two tests; 0.1 mol/L hydrochloric acid and water infused into the stomach. The presence and severity of 12 dyspeptic symptoms were assessed using a visual analogue scale.

RESULTS

The proportion of subjects developing symptoms by acid or water infusion was significantly greater in FD subjects than HCs. All of the FD subjects experienced at least one symptom by water or acid infusion. In the FD subjects, the severity of symptoms was significantly greater with acid infusion than water infusion. The severity of symptoms in total and the scores for eight of the 12 symptoms induced by acid infusion was significantly greater in FD subjects than in HCs.

CONCLUSIONS

The severity of dyspeptic symptom generation induced by direct acid infusion into the stomach was significantly greater in functional dyspepsia subjects than in healthy controls, suggesting that hypersensitivity to acid is one of the important mechanisms of the development of symptoms in functional dyspepsia patients.

Improvement of film Quality of A-Si:H Deposited by Photo-CVD using SiH2Cl2

Hydrogenated Amorphous silicon films (a-Si:H) were prepared by mercury sensitized photo-CVD using SiH4 and SiH2Cl2 gas mixture. The effects of chlorine (Cl) on the electrical, optical and structural properties of the a-Si:H films were investigated. It was found that a small addition of SiH2Cl2 to the deposition system increases the photo-sensitivity, decreases the defect density, and reduces the light induced degradation of a-Si:H films. At a large addition of SiH2Cl2, however, the CI incorporation into the films was observed, resulting in the deterioration of the film properties. The electrical and optical properties were successfully improved by the H2 dilution when the films were deposited with a large addition of SiH2Cl2.

Randomised clinical trial: efficacy of the addition of a prokinetic, mosapride citrate, to omeprazole in the treatment of patients with non-erosive reflux disease - a double-blind, placebo-controlled study

BACKGROUND

Proton pump inhibitors (PPIs) are less effective in non-erosive reflux disease (NERD) patients than in reflux oesophagitis patients. Whether the addition of prokinetics to PPIs improves NERD patients' symptoms remains unknown.

AIM

To evaluate the efficacy of mosapride in NERD patients when used with PPI.

METHODS

A total of 200 NERD patients were randomised to one of two arms: omeprazole (10 mg once daily) plus mosapride citrate (5 mg three times a day) (treatment arm) and omeprazole plus placebo (placebo arm). The primary endpoint was the rate of responders [visual analogue scale (VAS) was zero or <1 cm] after 4 weeks of treatment. The secondary endpoints were changes in the VAS score and the safety profile.

RESULTS

There was no significant difference between the rates of responders in both arms in intent-to-treat (ITT) and per-protocol (PP) analysis. The change in the VAS score in treatment arm was significantly better than placebo arm in PP analysis (-4.0 ± 0.2 and -3.3 ± 0.2, mean ± S.E.M.) (N.S. in ITT analysis). The rate of adverse events was similar in both groups.

CONCLUSION

The addition of mosapride to omeprazole was not more effective than omeprazole alone.

NK-1 receptor is involved in the decreased movement in a rat chronic acid reflux oesophagitis model

BACKGROUND

We previously reported that rats with reflux oesophagitis (RE) show a decrease in voluntary movement, which could be used as a measure of chronic visceral symptoms. However, what mediates these symptoms is still unknown, and pain-related neuropeptides or their receptors in oesophageal mucosa are possibly related to the symptom generation of oesophagitis. In the present study, we investigated the role of NK-1 receptor (NK-1R) as a mediator of oesophagitis symptoms.

METHODS

Chronic RE was surgically induced using rats. The degree or severity of oesophageal symptoms was evaluated by assessing voluntary movement, which was monitored using an infrared sensor system. The NK-1R antagonist, L-732,138, was administered and changes in voluntary movement were assessed. Ten days after surgery, the rats were killed to examine the oesophagus. NK-1R and tachykinin-1 mRNA were detected by real-time RT-PCR. NK-1R protein expression was examined by Western blotting.

KEY RESULTS

Voluntary movement of the oesophagitis model rats was significantly lower than that of the sham-operated rats on day 10. The size of oesophageal mucosal erosion did not correlate with the amount of voluntary movement. The amount of NK-1R protein and mRNA in the oesophageal tissue was significantly higher at both the erosion and non-erosion sites. The amount of tachykinin-1 mRNA in oesophageal tissue at the non-erosion sites was significantly higher in oesophagitis rats. The voluntary movement of oesophagitis rats was significantly increased by the administration of L-732,138.

CONCLUSIONS & INFERENCES

The NK-1R and related neuropeptides are possibly involved in the decrease in voluntary movement of RE.

Usefulness and faults of the sentinel lymph node biopsy using dye technique in distal gastrectomy for gastric cancer

e15509

Background: We apply sentinel node biopsy (SNB) in distal gastrectomy to perform it as safe limited surgery. Limited surgery is a procedure in which the extent of lesion resection and lymph node dissection is reduced. We assessed usefulness and faults of intraoperative diagnosis of lymph node metastasis in this regard. Methods: Surgical procedures: Patent blue (1%) is injected submucosally into 4 to 5 different sites at 1 mL per site around the primary tumor. If blue nodes are found, biopsy and diagnosis of metastasis are performed at this point. Subjects and methods: The study was conducted in 96 gastric cancer patients with a preoperative diagnosis of T1 or mp invasion. Informed consent was obtained from the all patients. There were 65 males and 31 females with a mean age of 64.2 years. Tumor invasion of m, sm, mp, ss, and se was identified in 44, 38, 8, 2, and 4 patients, respectively. All patients underwent open distal gastrectomy (DG) (n=31) or laparoscopy-assisted distal gastrectomy (LADG) (n=65) and Billroth-I reconstruction. Results: The mean number of BNs dissected was 4.5 and 3.7 in DG and LADG cases, respectively. Intraoperative identification and biopsy of BNs could be performed in 34 of 35 DG patients and in 58 of 61 LADG patients. Of the 34 patients in whom BNs were identified, 5 had metastases in BNs confirmed by intraoperative frozen section diagnosis in DG cases. On the other hand, of the 58 LADG patients in whom BNs were identified, 5 had metastases in BNs confirmed by intraoperative frozen section diagnosis in LADG case. False-negative rate was 1.9%. Conclusions: SNB can be performed in LADG as well as in DG. For the case that shows infiltration up to MP, the possibility of lymph node metastasis for other lymph node is considered to be negligible. In obese cases we had some cases of no BNs and false-negative. In consequence, as long as the infiltration is lower than MP, and confirmed that metastasis was not found by blue node biopsy, distal gastrectomy using limited surgery would be thought to be done safely.

No significant financial relationships to disclose.

Overexpression of EphA4 gene and reduced expression of EphB2 gene: Correlation with liver metastasis in colorectal cancer

e15129

The Eph receptors, members of a large family of transmembrane receptor tyrosine kinases, play important roles in a variety of biologic functions. Recent studies have suggested that EphA4 and EphB2 participate in the growth and development of various carcinomas. This study examined the relations of EphA4 and EphB2 gene expression to clinicopathological factors, especially metastasis, in patients with colorectal cancer. We studied surgical specimens of cancer tissue and adjacent normal mucosa obtained from 205 patients with untreated colorectal cancer. The relative expression levels of EphA4 and EphB2 mRNA in the specimens were measured by quantitative real-time, reverse-transcription polymerase chain reaction. The relative expression level of EphA4 mRNA was higher in the presence than in the absence of liver metastasis, whereas the relative expression levels of EphB2 mRNA were similar. Analysis of the relations between clinicopathological features and gene expression showed that high expression of the EphA4 gene and low expression of the EphB2 gene correlated with liver metastasis. There was no correlation between EphA4 and EphB2 gene expression. Our results suggest that over-expression of the EphA4 gene and reduced expression of the EphB2 gene might promote liver metastasis in colorectal cancer. Over-expression of the EphA4 gene and reduced expression of the EphB2 gene may thus be a useful predictor of liver metastasis in patients with colorectal cancer.

No significant financial relationships to disclose.

Experimental oesophagitis in the rat is associated with decreased voluntary movement

Growing interest has arisen regarding the mechanism of dyspeptic symptom generation. However, no evaluation system of these symptoms in animals has been developed. In this study, we examined whether voluntary movement of rats could be a measure to assess visceral symptoms of reflux oesophagitis. A chronic acid reflux oesophagitis model was made using rats, and the size of erosions was measured. Omeprazole was administered to the oesophagitis rats for 10 days. The amount of voluntary movement was measured by an infrared sensor. Intracellular spaces in oesophageal epithelium were also measured using a emission electron microscope. NP-40 soluble and insoluble fractions of claudins were examined by Western blot. Voluntary movement was significantly lower in the oesophagitis model rats than in the sham-operated rats (P < 0.01). Although omeprazole reduced the size of erosions, it did not significantly affect the total amount of voluntary movement (r = -0.033, P = 0.916). Intracellular spaces were significantly dilated in the oesophagitis model rats and claudin-3 showed a significantly lower relative quantity in the NP-40 insoluble fraction. Omeprazole significantly increased voluntary movement of oesophagitis model rats and the relative quantity of claudin-3 in the insoluble fraction (P < 0.05). Dilated intercellular spaces and the lower level of claudin-3 may relate to the voluntary movement of oesophagitis model rats. Decreases in voluntary movement of oesophagitis model rats may reflect visceral symptoms and be able to serve as an index of chronic abdominal symptoms.

Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists

The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.