Synaptotagmin XIII expression and peritoneal metastasis in gastric cancer

BACKGROUND

Peritoneal metastasis is a frequent cause of death in patients with gastric cancer. The aim of this study was to identify molecules responsible for mediating peritoneal metastasis of gastric cancer.

METHODS

Transcriptome and bioinformatics analyses were conducted to identify molecules associated with peritoneal metastasis. The therapeutic effects of intraperitoneally administered small interfering (si) RNA were evaluated using mouse xenograft models. Expression of mRNA and protein was determined in gastric tissues from patients with gastric cancer.

RESULTS

Synaptotagmin XIII (SYT13) was expressed at significantly higher levels in patients with peritoneal recurrence, but not in those with hepatic or distant lymph node recurrence. Inhibition of SYT13 expression in a gastric cancer cell line transfected with SYT13-specific siRNA (siSYT13) was associated with decreased invasion and migration ability of the cells, but not with proliferation and apoptosis. Intraperitoneal administration of siSYT13 significantly inhibited the growth of peritoneal nodules and prolonged survival in mice. In an analysis of 200 patients with gastric cancer, SYT13 expression in primary gastric cancer tissues was significantly greater in patients with peritoneal recurrence or metastasis. A high level of SYT13 expression in primary gastric cancer tissues was an independent risk factor for peritoneal recurrence.

CONCLUSION

SYT13 expression in gastric cancer is associated with perioneal metatases and is a potential target for treatment.

Pulp Regeneration by 3-dimensional Dental Pulp Stem Cell Constructs

Dental pulp regeneration therapy for the pulpless tooth has attracted recent attention, and clinical trial studies are underway with the tissue engineering approach. However, there remain many concerns, including the extended period for regenerating the dental pulp. In addition, the use of scaffolds increases the risk of inflammation and infection. To establish a basic technology for novel dental pulp regenerative therapy that allows transplant of pulp-like tissue, we attempted to fabricate scaffold-free 3-dimensional (3D) cell constructs composed of dental pulp stem cells (DPSCs). Furthermore, we assessed viability of these 3D DPSC constructs for dental pulp regeneration through in vitro and in vivo studies. For the in vitro study, we obtained 3D DPSC constructs by shaping sheet-like aggregates of DPSCs with a thermoresponsive hydrogel. DPSCs within constructs remained viable even after prolonged culture; furthermore, 3D DPSC constructs possessed a self-organization ability necessary to serve as a transplant tissue. For the in vivo study, we filled the human tooth root canal with DPSC constructs and implanted it subcutaneously into immunodeficient mice. We found that pulp-like tissues with rich blood vessels were formed within the human root canal 6 wk after implantation. Histologic analyses revealed that transplanted DPSCs differentiated into odontoblast-like mineralizing cells at sites in contact with dentin; furthermore, human CD31-positive endothelial cells were found at the center of regenerated tissue. Thus, the self-organizing ability of 3D DPSC constructs was active within the pulpless root canal in vivo. In addition, blood vessel-rich pulp-like tissues can be formed with DPSCs without requiring scaffolds or growth factors. The technology established in this study allows us to prepare DPSC constructs with variable sizes and shapes; therefore, transplantation of DPSC constructs shows promise for regeneration of pulpal tissue in the pulpless tooth.

Abstract P6-15-05: Randomized controlled trial of neoadjuvant eribulin mesylate versus paclitaxel in women with operable breast cancer (JONIE-3 study)

Background:

Although treatment of eribulin mesylate (E) improved overall survival in metastatic breast cancer (BC) patients, little is known about the efficacy in early BC. The hypothesis of this study is that sequential administration of E followed by FEC would have less toxic, particularly peripheral neuropathy, and also have similar effect compared to paclitaxel (P) followed by FEC as primary systemic therapy (PST) for woman with operable BC.

Methods:

This is a phase II multicenter open label study (UMIN000012817). Patients (pts) were randomly assigned to either E (1.4mg/m2, d1 and d8, q21 days, 4 cycles) + FEC (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2) or P (80mg/m2, weekly, 12 cycles) + FEC as PST. HER2+ patients were allowed to receive trastuzumab. Stratification factors were ER, HER2, and menopausal status. Primary endpoint was the incidence of peripheral sensory and motor neuropathy (PSN and PMN) with Grade 1 or higher according to CTCAE ver.4.0. Secondary endpoints were pathological complete response (pCR) rates (ypT0/is/ypN0), clinical response rates (CR+PR), and adverse events. Safety was assessed in all pts who received at least one dose of the study drug.

Results:

Between 12/2013 to 3/2016, 121 pts were randomly assigned equally to E + FEC and P + FEC. Excluding 5 pts from the primary assessment, 116 pts (58 in each group) were included in the full analysis set. The characteristics of the pts were similar in the two arms. At the end of E or P administration, the incidences of PSN were 55.4% and 92.9% in E and P arm, respectively (p<0.001). The incidences of PMN were 25.9% and 44.9% in E and P arm, respectively (p=0.049). At the end of E or P + FEC, PSN accounts for 38.9% in E arm and 85.2% in P arm (p<0.001), and PMN accounts for 20.7% in E arm and 32.8% in P arm (p=0.201). The pCR rates in E and P arm were 20.7% and 29.8% (p=0.092). The clinical response rates in E and P arm were 82.2% and 91.0% (p=0.108). No statistical significant difference was found in efficacy of PST between E and P.

Conclusion:

This randomized phase II study revealed that eribulin had favorable peripheral neuropathy profile with modest efficacy in the neoadjuvant setting, compared with paclitaxel.

Citation Format: Miura D, Hasegawa Y, Ishikawa T, Tachibana A, Horiguchi J, Hayashi M, Miyashita M, Kubota T, Narui K, Suzuki M, Akazawa K, Kohno N. Randomized controlled trial of neoadjuvant eribulin mesylate versus paclitaxel in women with operable breast cancer (JONIE-3 study) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-15-05.

Electrophysiological properties of anion exchangers in the luminal membrane of guinea pig pancreatic duct cells

The pancreatic duct epithelium secretes the HCO₃⁻-rich pancreatic juice. The HCO₃⁻ transport across the luminal membrane has been proposed to be mediated by SLC26A Cl⁻–HCO₃⁻ exchangers. To examine the electrophysiological properties of Cl⁻–HCO₃⁻ exchangers, we directly measured HCO₃⁻ conductance in the luminal membrane of the interlobular pancreatic duct cells from guinea pigs using an inside-out patch-clamp technique. Intracellular HCO₃⁻ increased the HCO₃⁻ conductance with a half-maximal effective concentration value of approximately 30 mM. The selectivity sequence based on permeability ratios was SCN⁻ (1.4) > Cl⁻ (1.2) = gluconate (1.1) = I⁻ (1.1) = HCO₃⁻ (1.0) > methanesulfonate (0.6). The sequence of the relative conductance was HCO₃⁻ (1.0) > SCN⁻ (0.7) = I⁻ (0.7) > Cl⁻ (0.5) = gluconate (0.4) > methanesulfonate (0.2). The current dependent on intracellular HCO₃⁻ was reduced by replacement of extracellular Cl⁻ with gluconate or by H₂DIDS, an inhibitor of Cl⁻–HCO₃⁻ exchangers. RT-PCR analysis revealed that the interlobular and main ducts expressed all SLC26A family members except Slc26a5 and Slc26a8. SLC26A1, SLC26A4, SLC26A6, and SLC26A10 were found to be localized to the luminal membrane of the guinea pig pancreatic duct by immunohistochemistry. These results demonstrate that these SLC26A Cl⁻–HCO₃⁻ exchangers may mediate the electrogenic HCO₃⁻ transport through the luminal membrane and may be involved in pancreatic secretion in guinea pig ducts.

Use of PIXE/PIGE for sequential Ca and F measurements in root carious model

The progress of caries has conventionally been evaluated by checking changes in mineral density using transverse microradiography (TMR). Recent advances have seen development of a new measurement system, using in-air micro proton induced X-ray/gamma-ray emission (PIXE/PIGE). PIXE/PIGE enables analysis of distributions and concentrations of multiple mineral elements in a carious lesion. The aim of this study was to evaluate the effectiveness of PIXE/PIGE for investigating the development of root caries. In summary, we successfully established a multi-elemental sequential measuring method using in-air micro-PIXE/PIGE to identify the dynamic distributions and concentrations of Ca and F in human root dentin. The PIXE/PIGE potentially offers a useful advantageous technique for studying carious development by using as a combination with conventional techniques such as TMR and Micro-computed tomography (µCT).

Reduced Mastication Impairs Memory Function

Mastication is an indispensable oral function related to physical, mental, and social health throughout life. The elderly tend to have a masticatory dysfunction due to tooth loss and fragility in the masticatory muscles with aging, potentially resulting in impaired cognitive function. Masticatory stimulation has influence on the development of the central nervous system (CNS) as well as the growth of maxillofacial tissue in children. Although the relationship between mastication and cognitive function is potentially important in the growth period, the cellular and molecular mechanisms have not been sufficiently elucidated. Here, we show that the reduced mastication resulted in impaired spatial memory and learning function owing to the morphological change and decreased activity in the hippocampus. We used an in vivo model for reduced masticatory stimuli, in which juvenile mice were fed with powder diet and found that masticatory stimulation during the growth period positively regulated long-term spatial memory to promote cognitive function. The functional linkage between mastication and brain was validated by the decrease in neurons, neurogenesis, neuronal activity, and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. These findings taken together provide in vivo evidence for a functional linkage between mastication and cognitive function in the growth period, suggesting a need for novel therapeutic strategies in masticatory function-related cognitive dysfunction.

Outcomes of grafting intrasynovial tendons of the toes to the hands in 10 patients: a preliminary report

Ten patients had intrasynovial tendon grafting harvested from the toes for secondary flexor tendon reconstruction in nine fingers and one thumb in our institutes from 2009 to 2014. These patients were followed for a mean of 15 (range: 8-36) months. The ranges of total active motion of the proximal and distal interphalangeal joints of these nine fingers were 143° (range: 108-175°) and of the metacarpophalangeal and interphalangeal joints of one thumb were 110°. In conclusion, this technique is feasible and gives a good result when successful but with a high complication rate. Level of Evidence IV.

Brassinosteroid Involvement in Arabidopsis thaliana Stomatal Opening

Stomata within the plant epidermis regulate CO2 uptake for photosynthesis and water loss through transpiration. Stomatal opening in Arabidopsis thaliana is determined by various factors, including blue light as a signal and multiple phytohormones. Plasma membrane transporters, including H+-ATPase, K+ channels and anion channels in guard cells, mediate these processes, and the activities and expression levels of these components determine stomatal aperture. However, the regulatory mechanisms involved in these processes are not fully understood. In this study, we used infrared thermography to isolate a mutant defective in stomatal opening in response to light. The causative mutation was identified as an allele of the brassinosteroid (BR) biosynthetic mutant dwarf5. Guard cells from this mutant exhibited normal H+-ATPase activity in response to blue light, but showed reduced K+ accumulation and inward-rectifying K+ (K+in) channel activity as a consequence of decreased expression of major K+in channel genes. Consistent with these results, another BR biosynthetic mutant, det2-1, and a BR receptor mutant, bri1-6, exhibited reduced blue light-dependent stomatal opening. Furthermore, application of BR to the hydroponic culture medium completely restored stomatal opening in dwarf5 and det2-1 but not in bri1-6. However, application of BR to the epidermis of dwarf5 did not restore stomatal response. From these results, we conclude that endogenous BR acts in a long-term manner and is required in guard cells with the ability to open stomata in response to light, probably through regulation of K+in channel activity.

Re-Examination of Arousing and De-Arousing Effects of Cigarette Smoking

An attempt was made to replicate arousing and de-arousing effects of cigarette smoking originally reported by Golding and Mangan. Changes in electrodermal activity, heart rate, and magnitude in the EEG alpha (7.5—11.5 Hz) and beta (13.5—20 Hz) bands were measured under conditions of both mild sensory isolation as well as stress induced by loud white-noise. Under both conditions, real smoking as well as sham smoking an unlit cigarette increased beta activity and the skin potential response. In contrast, only real smoking produced a significant increase in heart rate, decrease in alpha activity, and increase in skin potential. De-arousing effects reported by Golding and Mangan for white-noise stress were not replicated.

A Raf-like protein kinase BHP mediates blue light-dependent stomatal opening

Stomata in the plant epidermis open in response to blue light and affect photosynthesis and plant growth by regulating CO₂ uptake and transpiration. In stomatal guard cells under blue light, plasma membrane H⁺-ATPase is phosphorylated and activated via blue light-receptor phototropins and a signaling mediator BLUS1, and H⁺-ATPase activation drives stomatal opening. However, details of the signaling between phototropins and H⁺-ATPase remain largely unknown. In this study, through a screening of specific inhibitors for the blue light-dependent H⁺-ATPase phosphorylation in guard cells, we identified a Raf-like protein kinase, BLUE LIGHT-DEPENDENT H⁺-ATPASE PHOSPHORYLATION (BHP). Guard cells in the bhp mutant showed impairments of stomatal opening and H⁺-ATPase phosphorylation in response to blue light. BHP is abundantly expressed in the cytosol of guard cells and interacts with BLUS1 both in vitro and in vivo. Based on these results, BHP is a novel signaling mediator in blue light-dependent stomatal opening, likely downstream of BLUS1.

Abstract P5-16-10: Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial

BACKGROUND and AIM:

Findings from a randomized phase 2 JONIE1 trial in women with HER2-negative early breast cancer have shown that the addition of zoledronic acid (ZOL) to neoadjuvant chemotherapy (CT) has potential anticancer benefits in postmenopausal and triple-negative breast cancer patients. We report the data for the prespecified secondary endpoint of disease-free survival (DFS).

METHODS:

We enrolled women with HER2-negative early breast cancer and randomly assigned them to receive CT or CT+ZOL (CTZ). All patients received 4 cycles of FEC100 (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2), followed by 12 cycles of paclitaxel at 80 mg/m2 weekly. ZOL (4 mg) was administered 3-4 times weekly for 7 weeks to the CTZ group patients. Definitive surgery was performed 3-4 weeks after the last paclitaxel dose. The primary endpoint was pathological complete response (pCR). The secondary endpoints were the clinical response rates, rate of breast-conserving surgery, safety, and DFS (defined as the time from randomization to disease occurrence or death). The trial is registered as UMIN000003261 (www.umin.ac.jp/english/) with ongoing follow-up.

FINDINGS:

Of the 188 patients enrolled, 95 were assigned to the CT group and 93 to the CTZ group. The mean (95% CI) DFS time of the CT group was 5.15 years (4.83-5.47) and that of the CTZ group was 5.38 years (5.11-5.66). The 3-year DFS rate was 84.6% (95% CI 77.2-92.0) in the CT group and 90.7% (84.6-96.8) in the CTZ group with no significant difference (p = 0.120). The particular benefit from ZOL for the neoadjuvant CT seen as improvement of the pCR rate was indicated in the 3-year DFS period for triple-negative cancer cases (CT vs CTZ: 70.6% vs 94.1%), but not for postmenopausal cases.

CONCLUSIONS:

ZOL slightly improved DFS when combined with CT. Although a significant difference was not found in this study, plans are underway for conducting a combined analysis of 3 neoadjuvant CT trials together with ZOL. The improvement of the pCR rate may be associated with DFS in triple-negative cases. Previous studies have shown that ZOL was more efficacious in an estrogen-suppressed condition. However, the short-term application of ZOL in this study may not be sufficient to improve the outcome in postmenopausal patients.

Citation Format: Ishikawa T, Akazawa K, Hasegawa Y, Tanino H, Horiguchi J, Miura D, Hayashi M, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Kohno N. Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-10.

Reduction in chlorhexidine efficacy against multi-drug-resistant Acinetobacter baumannii international clone II

BACKGROUND

Nosocomial infections caused by Acinetobacter baumannii international clone II (IC II) can cause severe clinical outcomes.

AIM

Differential evaluation of bactericidal efficacy of chlorhexidine gluconate (CHX) and benzethonium chloride (BZT) disinfectants against IC II and non-IC II isolates.

METHODS

Minimum inhibitory concentrations (MICs) of CHX and BZT were determined for 137 A. baumannii IC II, 99 non-IC II and 69 non-baumannii isolates, further classified according to MIC values into disinfectant-reduced susceptible (DRS) and disinfectant-susceptible (DS) groups. Time-kill curves and minimum bactericidal concentrations (MBCs) were evaluated for representative isolates in each group.

RESULTS

CHX and BZT MIC₉₀s for IC II isolates were 100 and 175mg/L, respectively, but those for non-IC II and non-baumannii isolates were <100mg/L. Nevertheless, time-kill curves indicated that CHX and BZT reduced live bacterial cell number by 5 log₁₀ for IC II and non-IC II isolates within 30s when used at 1000mg/L, comparable to practical use concentrations. CHX MBC at 30s was 1000mg/L for IC II and non-IC II isolates, and was not influenced by addition of 3% bovine serum albumin (BSA); BZT MBC at 30s was 100mg/L without BSA and increased up to 500mg/L upon addition of BSA. No significant differences in BSA were found between DRS and DS isolates.

CONCLUSION

CHX and BZT were effective against Acinetobacter spp. including IC II at a concentration of 1000mg/L and exposure for at least 30s, but their concentrations should be considered carefully to ensure sufficient effects in both clinical and healthcare settings.

Allosteric Inhibitors against HIV-1 Reverse Transcriptase: Design and Synthesis of MKC-442 Analogues Having an Ω-Functionalized Acyclic Structure

Based on X-ray crystallographic analysis of MKC-442/human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) complex, analogues in which the N1-substituent is replaced with ω-functionalized alkyl groups were designed to improve the affinity for the enzyme. Synthesis of these compounds was carried out starting from MKC-442 by a sequence of reactions (N3-protection, removal of N1-ethoxymethyl group, alkylation, and N3-deprotection). The compounds were evaluated for anti-HIV activity. Structure–activity relationships are discussed in terms of the possible interaction with the enzyme.

Development of a Cavity Disinfectant Containing Antibacterial Monomer MDPB

An experimental cavity disinfectant (ACC) that is intended to be used for various direct and indirect restorations was prepared by adding an antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB) at 5% into 80% ethanol. The antibacterial effectiveness of ACC and its influences on the bonding abilities of resin cements were investigated. To examine the antibacterial activity of unpolymerized MDPB, the minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined for Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Parvimonas micra, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis. Antibacterial activities of ACC and the commercial cavity disinfectant containing 2% chlorhexidine and ethanol (CPS) were evaluated by agar disk diffusion tests through 7 bacterial species and by MIC and MBC measurement for S. mutans. The effects of ACC and CPS to kill bacteria in dentinal tubules were compared with an S. mutans–infected dentin model. Shear bond strength tests were used to examine the influences of ACC on the dentin-bonding abilities of a self-adhesive resin cement and a dual-cure resin cement used with a primer. Unpolymerized MDPB showed strong antibacterial activity against 7 oral bacteria. ACC produced inhibition zones against all bacterial species similar to CPS. For ACC and CPS, the MIC value for S. mutans was identical, and the MBC was similar with only a 1-step dilution difference (1:2). Treatment of infected dentin with ACC resulted in significantly greater bactericidal effects than CPS ( P < 0.05, analysis of variance and Tukey’s honest significant difference test). ACC showed no negative influences on the bonding abilities to dentin for both resin cements, while CPS reduced the bond strength of the self-adhesive resin cement ( P < 0.05). This study clarified that the experimental cavity disinfectant containing 5% MDPB is more effective in vitro than the commercially available chlorhexidine solution to eradicate bacteria in dentin, without causing any adverse influences on the bonding abilities of resinous luting cements.

Evaluation of the pharmacokinetic parameters of standard oral antibiotics in a bioequivalence study of generic products

Pharmacokinetic parameters were summarized in clinical bioequivalence studies in Japan to confirm the validity for the use of parameters obtained from the clinical studies. Pharmacokinetic parameters, including maximum plasma/serum concentrations (Cmax), area under the plasma/serum drug concentration-time curve (AUC), time to achieve Cmax (Tmax), and half life (t1/2), of the standard products (original drugs) after oral administration of antimicrobials, including respiratory quinolones, cephalosporins, macrolides, and penicillin-based antibiotics were investigated by use of interview forms and/or package inserts from the generic products and the relationship among the pharmacokinetic parameters such as Cmax, AUC, Tmax, and t1/2 were estimated. In all the studies, the standard and generic products were administrated orally to healthy fasting subjects. Although there was more than a 1.5-fold difference in the Cmax and AUC0-24 h, but not in the Tmax and t1/2 values for levofloxacin tablets and cefacrol tablets, these parameters for other antibiotics were similar in various studies. The obtained results suggested that the parameters obtained from recent bioequivalence studies would be useful in identifying pharmacokinetic behavior of the original drugs, especially early time release; however, the pharmacokinetic results obtained from the recently conducted bioequivalence studies may be superior to those obtained from studies conducted in the past.

Systemic and Eosinophilic Lesions in Rats with Spontaneous Eosinophilia (mes Rats)

The mes rat is from an inbred mutant colony of rats with spontaneous eosinophilia. In order to investigate the pathogenesis of the mes rat, the histopathology and hematology for 76 mes rats were examined at several weeks of age. Tissue eosinophilia developed at 8 weeks of age when the blood eosinophil was 500 cells per microliter or more. Subsequently, eosinophilia progressed with age, and splenic eosinophilopoiesis and erythropoiesis appeared simultaneously. Many inflammatory lesions were induced after 10 weeks of age when the blood eosinophils became 1,000 cells per microliter or more. Gastroenteritis and mesenteric lymphadenitis were seen in 44 of 47 (94%) and 31 of 47 (66%) rats, respectively, after 10 weeks of age. Aortitis that deteriorated with age was found in 19 of 39 (49%) rats after 12 weeks of age. Hepatic fibrosis was found in four rats that exhibited severe eosinophilia and anemia. These results are comparable to the features of a hypereosinophilic syndrome in humans and other animals.