Background:Several recent studies demonstrated that microRNAs (miRNAs) are stably detectable in plasma/serum. We hypothesised that plasma miRNAs concentrations contributed to potential biomarkers in patients with oesophageal squamous cell carcinoma (ESCC).Methods:We selected three oncogenic miRNAs (miR-21, miR-184, miR-221) and one tumour suppressive miRNA (miR-375), which are frequently reported in squamous cell carcinoma, as candidate targets for this plasma miRNA assay. This study was divided into three steps: (1) Determination of appropriate plasma miRNAs in preliminary tests. (2) Evaluation of whether the plasma miRNA assays could monitor tumour dynamics. (3) Validation study on the clinical application of plasma miRNA assays in 50 ESCC patients and 20 healthy volunteers.Results:(1) In preliminary tests, the plasma level of miR-21 was significantly higher (P=0.0218) and that of miR-375 (P=0.0052) was significantly lower in ESCC patients than controls. (2) The high plasma miR-21 levels reflected tumour levels in all cases (100%). The plasma level of miR-21 was significantly reduced in postoperative samples (P=0.0058). (3) On validation analysis, the plasma level of miR-21 tended to be higher in ESCC patients (P=0.0649), while that of miR-375 was significantly lower (P<0.0001) and the miR-21/miR-375 ratio was significantly higher (P<0.0001) in ESCC patients than in controls. The value of the area under the receiver-operating characteristic curve (AUC) was 0.816 for the miR-21/miR-375 ratio assay. Patients with a high plasma level of miR-21 tended to have greater vascular invasion (P=0.1554) and to show a high correlation with recurrence (P=0.0164).Conclusion:Detection of circulating miRNAs might provide new complementary tumour markers for ESCC.

The Th1/Th2 ratio may be a good prognostic indicator and may also be a promising marker for estimating the effectiveness of surgery. NLR may also be a good prognostic indicator and may be a valid marker of tumor recurrence, and it appeared that some interaction between lymphocytes and neutrophils had occurred.

Background:SET and MYND domain-containing protein 2 (SMYD2) is a lysine methyltransferase for histone H3, p53 and Rb and inhibits their transactivation activities. In this study, we tested whether SMYD2 (1q42) acts as a cancer-promoting factor by being overexpressed in gastric cancer.Methods:We analysed 7 gastric cancer cell lines and 147 primary tumor samples of gastric cancer, which were curatively resected in our hospital.Results:SET and MYND domain-containing protein 2 was detected in these cell lines (five out of seven cell lines; 71.4%) and primary tumor samples (fifty-six out of one hundred and forty-seven cases; 38.1%). Knockdown of SMYD2 using specific small interfering RNA inhibited proliferation, migration and invasion of SMYD2-overexpressing cells in a TP53 mutation-independent manner. Overexpression of SMYD2 protein correlated with larger tumor size, more aggressive lymphatic invasion, deeper tumor invasion and higher rates of lymph node metastasis and recurrence. Patients with SMYD2-overexpressing tumours had a worse overall rate of survival than those with non-expressing tumours (P=0.0073, log-rank test) in an intensity and proportion score-dependent manner. Moreover, multivariate analysis demonstrated that SMYD2 was independently associated with worse outcome (P=0.0021, hazard ratio 4.25 (1.69–10.7)).Conclusions:These findings suggest that SMYD2 has a crucial role in tumor cell proliferation by its overexpression and highlight its usefulness as a prognostic factor and potential therapeutic target in gastric cancer.

In the course of screening for inhibitors of the lymphocyte kinase, Lck (p56^fc), aiming at novel immunosuppressants, we isolated a novel alkaloid, lymphostin (LK6-A), from the culture broth of Streptomyces sp. KYI1783. Lymphostin was produced in a fermentation mediumsupplemented with a highly porous polymer resin, which prevented the degradation of this compound in the culture broth. Lymphostin inhibited the kinase activity of Lck with an IC50 value of 0.05jUM, and exhibited potent inhibitory activity against the mixed lymphocyte reaction (MLR) with an IC50 value of 0.009um.

Abstract. The effects of Phx-3 on changes in intracellular pH (pH i ) in the MKN45 and MKN74 human gastric cancer cell lines were evaluated in order to determine the mechanism for the proapoptotic effects of 2-aminophenoxazine-3-one (Phx-3) on these cells. Phx-3 (100 μM) reduced pH i in MKN45 from 7.45 to 5.8, and in MKN74 from 7.5 to 6.2 within 1 min of engagement with these cells. Such a decrease of pH i was closely correlated with the dose of this phenoxazine and continued for 4 h. The activity of Na + /H + exchanger isoform l (NHE1), which is involved in H + extrusion from the cells, was dose-dependently suppressed by Phx-3 in these cells, and was greatly suppressed in the presence of 100 μM Phx-3. This result indicates that the decrease of pH i in MKN45 and MKN74 cells is closely associated with the inhibition of NHE1 in these cells. The morphology of these cells at 24 h after treatment with Phx-3 indicated shrinkage of the cells and condensation of the nuclear chromatin structure, which are characteristic of the apoptotic events in these gastric cancer cells. Cytotoxicity of Phx-3 against MKN45 and MKN74 cells was extensive because almost all MKN45 cells lost viability at 24 h in the presence of 20 μM Phx-3, and nearly 50% of the MKN74 cells lost viability in the presence of 50 μM Phx-3. These results suggest that rapid and extensive decrease of pH i in human gastric cancer MKN45 and MKN74 cells caused by Phx-3 might disturb intracellular homeostasis, leading to apoptotic and cytotoxic events in these cells. Phx-3 is a good candidate for therapeutics of gastric cancer that is intractable to conventional chemopreventive therapies. IntroductionIt has been suggested that a decrease of intracellular pH (pH i ) precedes apoptotic events in cancer cells (1,2). Therefore, drugs to induce pH i reduction have been considered good candidates for treating cancer and causing programmed cell death (3). For example, cyclohexamide, etoposide, and camptothesin decrease pH i in cancer cells, leading to apoptosis of the cells (3-5); however, these drugs often exert significant adverse effects on the body (6,7).The oxidative phenoxazines [e.g., 2-amino-4,4·-dihydro-4·,7-dimethyl-3H-phenoxazine-3-one (Phx-1) and 2-aminophenoxazine-3-one (Phx-3)] exert anticancer effects on various species of cancer cells in vitro (8-10) and in vivo, without marked adverse effects (11-13). Recently, Che et al (14) reported that apoptotic events in KB-3-1 cells (human epidermoid carcinoma cell line) and K562 cells (human chronic myeloid leukemia cell line) are preceded by a decrease in pH i in cells treated with Phx-3, a phenoxazine produced by the reaction of o-aminophenol with bovine hemoglobin. However, the detailed mechanism for pH i decrease in these cancer cells with Phx-3 remains unclear.Regarding the regulation of pH i , it has been suggested that among Na + /H + exchangers, Na + /H + exchanger isoform 1 (NHE1) is ubiquitously present in the plasma membrane in the cells and plays a pivotal role in regulating pH i (15)(16)(17). Therefore...