[Effective S-1 plus Oxaliplatin(SOX)Therapy in Two Cases of Advanced Gastric Cancer That Was Difficult to Resect and R0 Surgery Could Be Performed].

Case 1: A 59-year-old man was diagnosed with type 3 gastric cancer cStage Ⅲ(MU, Gre, tub2>por, cT4aN2M0)induced by gastric perforation. The first surgery involving resection of the lesser curvature of stomach lymph node was judged to be difficult, and eventually exploratory laparotomy was performed. He received 3 courses of chemotherapy using S-1 plus oxaliplatin(SOX)(S-1 120mg/m2/day, day 1-14, oxaliplatin 100 mg/m2, day 1, followed by 7 days of rest). He subsequently underwent curative laparotomy gastrectomy plus D2(-No. 10)lymph node dissection, and Roux-en-Y reconstruction. Histological type was judged to be Grade 3. Case 2: A 69-year-old man was diagnosed with type 2 esophageal gastric junctional cancer,(GE, Less, tub2, cT4aN3M1[LYM])of cStage Ⅳ. He received 6 courses of chemotherapy using trastuzu- mab plus S-1 plus oxaliplatin(HER plus SOX)(trastuzumab 8mg/kg[2nd course 6mg/kg], day 1, S-1 120mg/m2/day, day 1-14, oxaliplatin 100mg/m2[5th course 80 mg/m2], on day 1, followed by 7 days of rest). He subsequently underwent laparotomy of the lower esophageal total gastrectomy plus D2(-No. 10, +No. 16, No. 110)lymph node dissection, and Roux-en-Y reconstruction as conversion surgery. Histological type was Grade 3. Both were impressive cases suggesting the usefulness of SOX therapy as a multidisciplinary treatment strategy for advanced gastric cancer.

Synthetic miR-143 Inhibits Growth of HER2-Positive Gastric Cancer Cells by Suppressing KRAS Networks Including DDX6 RNA Helicase.

Gastric cancer (GC) is one of the most common cancers worldwide. In the clinical setting, the identification of HER2 overexpression in GC was a significant finding, as trastuzumab, an anti-HER2 drug, provides a survival advantage to HER2-positive GC patients. In HER2-postive GC, the dysregulation of PI3K/AKT and MAPK/ERK signaling pathways has been reported, and inhibition of these pathways is an important therapeutic strategy. MiR-143 is known to act as a tumor suppressor in several cancers, such as bladder cancer, breast cancer, colorectal cancer, and gastric cancer. In the current study, we developed a novel chemically-modified miR-143 and explored the functions of this synthetic miR-143 (syn-miR-143) in HER2-positive gastric cancer. The expression level of miR-143 was down-regulated in GC cell lines, including HER2-positive GC cell lines, MKN7, and KATO-III. The ectopic expression of miR-143 in those cell lines suppressed cell growth through systemic silencing of KRAS and its effector signaling molecules, AKT and ERK. Furthermore, syn-miR-143 indirectly down-regulated the expression of HER2, an upstream molecule of KRAS, through silencing DEAD/H-box RNA helicase 6 (DDX6), RNA helicase, which enhanced HER2 protein expression at the translational step in HER2-positive GC cells. These findings suggested that syn-miR-143 acted as a tumor suppressor through the impairment of KRAS networks including the DDX6.

DEAD-Box Protein RNA-Helicase DDX6 Regulates the Expression of HER2 and FGFR2 at the Post-Transcriptional Step in Gastric Cancer Cells.

The human DEAD/H-box RNA helicase DDX6 (RCK/p54) is a protein encoded by the fusion gene from the t(11;14)(q23;q32) chromosomal translocation observed in human B-cell lymphoma cell line RC-K8. DDX6 has a variety of functions such as translation initiation, pre-mRNA splicing, and ribosome assembly. However, details of the regulatory mechanism governing DDX6 and the functions of DDX6 are largely unknown. Previously, we reported that DDX6 is overexpressed in most malignant cell lines and clinical colorectal tumor samples and that DDX6 positively contributes to the pathogenesis of various cancers. In the current study, we aimed at revealing the function of DDX6 in HER2 and FGFR2 related human gastric cancer (GC) by using clinical samples and GC cell lines. DDX6 protein was overexpressed in about 60% of the clinical samples; HER2, in 35%; and FGFR2, in 30%, (n = 20). Interestingly, the DDX6 protein was overexpressed in all HER2-positive samples (n = 7), and in 83% (5 of 6) of the FGFR2-positive samples, which could reflect the contribution of DDX6 to the expression of HER2 and FGFR2. In the GC cell line MKN7, which has HER2 amplification, the knockdown of DDX6 by siR-DDX6 led to the decreased expression of the HER2 protein. On the other hand, the knockdown of HER2 did not influence the DDX6 expression. Similar results were also obtained for the KATO-III and HSC39 cell lines having amplified FGFR2 expression. The increased expression of DDX6 induced a significantly increased expression of the HER2 protein without increasing the mRNA expression. The results of an RNP Immunoprecipitation (RIP)-assay using GC cells indicated that the DDX6 protein acted as an RNA-binding protein for HER2 and FGFR2 mRNAs and positively regulated their post-transcriptional processes. These findings demonstrated that DDX6 was an upstream molecule that positively regulated the expression of HER2 and FGFR2 at the post-transcriptional step in GC cells.

Oncogene RNA helicase DDX6 promotes the process of c-Myc expression in gastric cancer cells.

Human DEAD-box RNA helicase gene DDX6 was cloned from B-cell lymphoma cell line RC-K8. Previously, we reported that DDX6 acts as oncogene in several cancers such as colorectal cancer and hepatocellular carcinoma. However, the detailed mechanism of DDX6 action in carcinogenesis is largely unknown. In this study, we examined the functions of DDX6 in clinical gastric cancer (GC) samples and GC cells. DDX6 protein expression levels of cancer samples were higher than those of the adjacent normal tissues in 25 clinical GC samples (median value: 1.4 times higher). Also, the results of an RNA immunoprecipitation-assay (RIP-assay) showed that DDX6 associated with c-Myc mRNA. Moreover, enforced overexpression of DDX6 promoted both mRNA and protein expression of c-Myc in GC cells. On the other hand, the gene silencing of DDX6 induced growth suppression through down-regulation of c-Myc in GC cells grown in either two or three dimensions. Furthermore, c-Myc mRNA expression levels of cancer samples were higher than those of the adjacent normal tissues in DDX6 up-regulated-GC clinical samples. Our findings in this study suggested that DDX6 acted as oncogene in GC cells through promotion of c-Myc expression by association with the mRNA of c-Myc.

[A Case Report of Anal Canal Squamous Cell Carcinoma with Poor Prognosis That Occurred Nine Years after Subtotal Colectomy for Ulcerative Colitis].

Ulcerative colitis(UC)is a chronic inflammatorydisease. Since it is known to be a risk factor for colorectal cancer, severe cases, refractorycases, or cases with cancer are often treated with surgery. We report a case of anal canal squamous cell carcinoma(SCC)found 9 years after subtotal colectomy for UC. A 32-year-old man underwent subtotal colectomyand ileorectum anastomosis 9 years ago for fulminant UC. Anemia was detected during treatment with infliximab, which was initiated 2 years ago. Endoscopic findings revealed a type 3 tumor at the anal canal in the anastomotic region, and he presented to our department. Further examination confirmed the diagnosis of anal SCC. Multimodalitytherapywas performed; however, the patient died 9 months after the first presentation to our hospital. UC has a high incidence of juvenile onset and is associated with increased risk for developing cancer; therefore, considering this case, we want to emphasize on the importance of long- term surveillance.

MiR-133b inhibits growth of human gastric cancer cells by silencing pyruvate kinase muscle-splicer polypyrimidine tract-binding protein 1.

The metabolism in tumor cells shifts from oxidative phosphorylation to glycolysis even in an aerobic environment. This phenomenon is known as the Warburg effect. This effect is regulated mainly by polypyrimidine tract-binding protein 1 (PTBP1), which is a splicer of the mRNA for the rate-limiting enzymes of glycolysis, pyruvate kinase muscle 1 and 2 (PKM1 and PKM2). In the present study, we demonstrated that miR-133b reduced PTBP1 expression at translational level and that the expression levels of miR-133b were significantly downregulated in gastric cancer clinical samples and human cell lines, whereas the protein expression level of PTBP1 was upregulated in 80% of the 20 clinical samples of gastric cancer examined. Ectopic expression of miR-133b and knockdown of PTBP1 in gastric cancer cells inhibited cell proliferation through the induction of autophagy by the switching of PKM isoform expression from PKM2-dominant to PKM1-dominant. The growth inhibition was partially canceled by an autophagy inhibitor 3-MA or a reactive oxygen species scavenger N-acetylcysteine. These findings indicated that miR-133b acted as a tumor-suppressor through negative regulation of the Warburg effect in gastric cancer cells.

Enoxaparin and fondaparinux attenuates endothelial damage in endotoxemic rats.

BACKGROUND: Prophylactic use of anticoagulants for septic patients in intensive care unit is a standard therapy for the prevention of venous thrombosis. Moreover, recent studies have demonstrated the anti-inflammatory effects of anticoagulants such as Factor Xa inhibitors and heparins. However, there have been no studies to examine the effects of fondaparinux and enoxaparin when applied in a sepsis model. Therefore, we examined the anti-inflammatory effects and bleeding events when these agents are applied in a lipopolysaccharide challenge model. METHODS: Wistar rats received lipopolysaccharides followed by a bolus infusion of fondaparinux, enoxaparin, or placebo. Microscopic observation of the mesenteric microcirculation for endothelial damage and measurement of bleeding area after vascular puncture was performed (n = 6 in each group). In another series, blood samples were taken, and blood cell counts, coagulation markers, and organ damage markers were measured (n = 6 in each). RESULTS: Both leukocyte adherence to vascular endothelium and endothelial damage were reduced in fondaparinux and enoxaparin groups. The bleeding area was markedly increased in the fondaparinux group. Coagulation markers were maintained better in the enoxaparin group. Levels of organ damage markers were significantly suppressed in both fondaparinux and enoxaparin groups (p < 0.01, compared with control, each). CONCLUSIONS: Fondaparinux and enoxaparin reduce organ dysfunction by decreasing endothelial damage. However, bleeding was more prominent in the fondaparinux group compared with the enoxaparin group at an equipotent dose for anti-Xa activity. Because the setting of this experiment is different from the clinical use, further study is required for the comparison of both pharmaceuticals.