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Sachio Fushida,1 Jun Kinoshita,1 Masahide Kaji,2 Katsunobu Oyama,1 Yasuo Hirono,3 Tomoya Tsukada,2 Takashi Fujimura,4 Tetsuo Ohta1 On behalf of the Digestive Disease Support Organization Study Group 1Department of Gastroenterological Surgery, Kanazawa University Hospital, Kanazawa, 2Department of Surgery, Toyama Prefectural Central Hospital, Toyama, 3First Department of Surgery, Fukui University Hospital, Fukui, 4Department of Surgery, Toyama City Hospital, Toyama, Japan Background: Weekly paclitaxel (wPTX) is the preferred second-line chemotherapy for gastric cancer in Japan. Histone deacetylase inhibitors have been shown to decrease proliferation through cell-cycle arrest, differentiation, and apoptosis in gastric cancer cells. One histone deacetylase inhibitor, valproic acid (VPA), also inhibits tumor growth by inducing apoptosis and enhances the efficacy of paclitaxel (PTX), shown in a murine gastric cancer model. This Phase II trial was designed to evaluate the benefits of adding VPA to wPTX in patients with gastric cancer refractory to first-line treatment with fluoropyrimidine.Patients and methods: The patients were randomly assigned in a 1:1 ratio to receive PTX 80 mg/m2 intravenously on days 1, 8, and 15, every 4 weeks, or a dose of PTX plus VPA taken everyday at 7.5 mg/kg twice daily. Random assignment was carried out at the data center with a minimization method adjusted by the Eastern Cooperative Oncology Group performance status (0–1 vs 2), prior chemotherapy (first-line vs second-line), and measurable lesions (presence vs absence). The primary end point was the overall survival (OS) rate, and the secondary end points were the progression-free survival rate and safety analysis.Results: Sixty-six patients were randomly assigned to receive wPTX (n=33) or wPTX plus VPA (n=33). The median OS was 9.8 months in the wPTX group and 8.7 months in the wPTX plus VPA group (hazard ratio 1.19; 95% CI 0.702–2.026; P=0.51). The median progression-free survival was 4.5 months in the wPTX group and 3.0 months in the wPTX plus VPA group (hazard ratio 1.29; 95% CI 0.753–2.211; P=0.35). Grade 3–4 adverse events were neutropenia (3.1%), pneumonia (1.6%), liver injury (1.6%), brain infarction (1.6%), and rupture of aorta (1.6%).Conclusion: No statistically significant difference was observed between wPTX and wPTX plus VPA for OS. Keywords: valproic acid, paclitaxel, second- or third-line therapy, advanced gastric cancer

Sachio Fushida,1,2 Katsunobu Oyama,1,2 Masahide Kaji,2 Yasuo Hirono,2 Jun Kinoshita,1,2 Tomoya Tsukada,1,2 Hideaki Nezuka,2 Tatsuo Nakano,2 Masahiro Noto,2 Koji Nishijima,2 Takashi Fujimura,2 Tetsuo Ohta1,2 1Department of Gastroenterological Surgery, Kanazawa University Hospital, 2Digestive Disease Support Organization (DDSO), Kanazawa, Japan Background: Tiotropium, a long-acting inhaled anticholinergic drug, has been widely used in the treatment of chronic obstructive pulmonary disease (COPD). However, the issue of whether perioperative tiotropium improves postoperative outcomes for gastric cancer patients with COPD remains unclear. Thus, the aim of this study was to determine the efficacy of perioperative tiotropium intervention for gastric cancer patients with COPD.Patients and methods: Eighty-four gastric cancer patients with mild-to-moderate COPD were randomly assigned to receive perioperative pulmonary rehabilitation alone (control group) or pulmonary rehabilitation with 18 µg of tiotropium once daily (tiotropium group). The patients in the tiotropium group received tiotropium for more than 1 week before surgery and for 2 weeks after surgery. Spirometry was performed prior to group assignment and at 2 weeks after surgery. Postoperative complications, forced expiratory volume in 1 second, forced vital capacity, and the ratio of forced expiratory volume in second to forced vital capacity (%) were compared between the two groups.Results: There were no significant differences between the two groups in terms of age, body mass index, smoking, gastrectomy incision, operation time, and bleeding volume (all P>0.05). Postoperative complications and pulmonary functions did not differ significantly between the control and tiotropium groups. A subgroup analysis of gastric cancer patients with moderate COPD showed that perioperative tiotropium intervention significantly decreased the rate of postoperative complications compared with the control group (P=0.046). However, even after gastrectomy, many patients with mild COPD in both the control and tiotropium groups showed improved pulmonary function.Conclusion: Although perioperative tiotropium intervention had no significant effects in gastric cancer patients with mild COPD, it may be beneficial in those with moderate COPD. Therefore, the next prospective study should further evaluate perioperative tiotropium intervention for gastric cancer patients with moderate-to-severe COPD. Keywords: gastric cancer, COPD, tiotropium

The molecular mechanisms that allow pathogenic bacteria to infect animals have been intensively studied. On the other hand, the molecular mechanisms by which bacteria acquire virulence functions are not fully understood. In the present study, we experimentally evaluated the evolution of a non-pathogenic strain of Escherichia coli in a silkworm infection model and obtained pathogenic mutant strains. As one cause of the high virulence properties of E. coli mutants, we identified amino acid substitutions in LptD (G580S) and LptE (T95I) constituting the lipopolysaccharide (LPS) transporter, which translocates LPS from the inner to the outer membrane and is essential for E. coli growth. The growth of the LptD and LptE mutants obtained in this study was indistinguishable from that of the parent strain. The LptD and LptE mutants exhibited increased secretion of outer membrane vesicles containing LPS and resistance against various antibiotics, antimicrobial peptides, and host complement. In vivo cross-linking studies revealed that the conformation of the LptD-LptE complex was altered in the LptD and LptE mutants. Furthermore, several clinical isolates of E. coli carried amino acid substitutions of LptD and LptE that conferred resistance against antimicrobial substances. This study demonstrated an experimental evolution of bacterial virulence properties in an animal infection model and identified functional alterations of the growth-essential LPS transporter that led to high bacterial virulence by conferring resistance against antimicrobial substances. These findings suggest that non-pathogenic bacteria can gain virulence traits by changing the functions of essential genes, and provide new insight to bacterial evolution in a host environment.