Tailor-made amino acid-derived pharmaceuticals approved by the FDA in 2019

Amino acids (AAs) are among a handful of paramount classes of compounds innately involved in the origin and evolution of all known life-forms. Along with basic scientific explorations, the major goal of medicinal chemistry research in the area of tailor-made AAs is the development of more selective and potent pharmaceuticals. The growing acceptance of peptides and peptidomimetics as drugs clearly indicates that AA-based molecules become the most successful structural motif in the modern drug design. In fact, among 24 small-molecule drugs approved by FDA in 2019, 13 of them contain a residue of AA or di-amines or amino-alcohols, which are commonly considered to be derived from the parent AAs. In the present review article, we profile 13 new tailor-made AA-derived pharmaceuticals introduced to the market in 2019. Where it is possible, we will discuss the development form drug-candidates, total synthesis, with emphasis on the core-AA, therapeutic area, and the mode of biological activity.

Design and Evaluation of Anti-SARS-Coronavirus Agents Based on Molecular Interactions with the Viral Protease

Three types of new coronaviruses (CoVs) have been identified recently as the causative viruses for the severe pneumonia-like respiratory illnesses, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and corona-virus disease 2019 (COVID-19). Neither therapeutic agents nor vaccines have been developed to date, which is a major drawback in controlling the present global pandemic of COVID-19 caused by SARS coronavirus 2 (SARS-CoV-2) and has resulted in more than 20,439,814 cases and 744,385 deaths. Each of the 3C-like (3CL) proteases of the three CoVs is essential for the proliferation of the CoVs, and an inhibitor of the 3CL protease (3CL^pro) is thought to be an ideal therapeutic agent against SARS, MERS, or COVID-19. Among these, SARS-CoV is the first corona-virus isolated and has been studied in detail since the first pandemic in 2003. This article briefly reviews a series of studies on SARS-CoV, focusing on the development of inhibitors for the SARS-CoV 3CL^pro based on molecular interactions with the 3CL protease. Our recent approach, based on the structure-based rational design of a novel scaffold for SARS-CoV 3CL^pro inhibitor, is also included. The achievements summarized in this short review would be useful for the design of a variety of novel inhibitors for corona-viruses, including SARS-CoV-2.

Development of gastroenterological surgery over the last decade in Japan: analysis of the National Clinical Database

The National Clinical Database (NCD) of Japan was established in 2010 with the board certification system. A joint committee of 16 gastroenterological surgery database-affiliated organizations has been nurturing this nationwide database and utilizing its data for various analyses. Stepwise board certification systems have been validated by the NCD and are used to improve the surgical outcomes of patients. The use of risk calculators based on risk models can be particularly helpful for establishing appropriate and less invasive surgical treatments for individual patients. Data obtained from the NCD reflect current developments in the surgical approaches used in hospitals, which have progressed from open surgery to endoscopic and robot-assisted procedures. An investigation of the data acquired by the NCD could answer some relevant clinical questions and lead to better surgical management of patients. Furthermore, excellent surgical outcomes can be achieved through international comparisons of the national databases worldwide. This review examines what we have learned from the NCD of gastroenterological surgery and discusses what future developments we can expect.

Potential role of transforming growth factor-beta 1/Smad signaling in secondary lymphedema after cancer surgery

Secondary lymphedema often develops after cancer surgery, and over 250 million patients suffer from this complication. A major symptom of secondary lymphedema is swelling with fibrosis, which lowers the patient's quality of life, even if cancer does not recur. Nonetheless, the pathophysiology of secondary lymphedema remains unclear, with therapeutic approaches limited to physical or surgical therapy. There is no effective pharmacological therapy for secondary lymphedema. Notably, the lack of animal models that accurately mimic human secondary lymphedema has hindered pathophysiological investigations of the disease. Here, we developed a novel rat hindlimb model of secondary lymphedema and showed that our rat model mimics human secondary lymphedema from early to late stages in terms of cell proliferation, lymphatic fluid accumulation, and skin fibrosis. Using our animal model, we investigated the disease progression and found that transforming growth factor‐beta 1 (TGFB1) was produced by macrophages in the acute phase and by fibroblasts in the chronic phase of the disease. TGFB1 promoted the transition of fibroblasts into myofibroblasts and accelerated collagen synthesis, resulting in fibrosis, which further indicates that myofibroblasts and TGFB1/Smad signaling play key roles in fibrotic diseases. Furthermore, the presence of myofibroblasts in skin samples from lymphedema patients after cancer surgery emphasizes the role of these cells in promoting fibrosis. Suppression of myofibroblast‐dependent TGFB1 production may therefore represent an effective pharmacological treatment for inhibiting skin fibrosis in human secondary lymphedema after cancer surgery.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2018

The National Clinical Database (NCD) of Japan grew rapidly, harvesting over 11 million cases of data between 2011 and 2018 from more than 5000 facilities. This is the Report of the NCD based upon gastrointestinal surgery information in 4 420 175 cases from 2011 to 2018. More than 70% of all gastrointestinal surgeries were performed at certified institutions, and the percentage of surgeries performed at certified institutions was particularly high for the esophagus (93.8% in 2018), liver (89.4%), pancreas (91.3%), and spleen (86.9%). Also, more than 70% of the surgeries were performed with the participation of the board-certified surgeon. As the patients have been getting older, the morbidities have been increasing. However, the mortalities have been kept at a low level. The rates of endoscopic surgery have been increasing year by year, especially high in low anterior resection (67.0%) and esophagectomy (61.0%). Nationwide, this database is surely expecting to ensure the quality of board certification system and surgical outcomes in gastroenterological surgery.

Development of a model predicting the risk of eight major postoperative complications after esophagectomy based on 10 826 cases in the Japan National Clinical Database

BACKGROUND

Esophagectomy is a highly invasive procedure with a high incidence of complications. The objectives of this study were to create risk prediction models for postoperative morbidity associated with esophagectomy and to test their performance using a population-based large database.

METHODS

A total of 10 862 patients who underwent esophagectomy between January 2011 and December 2012 derived from the Japanese national clinical database (NCD) were included. Based on the 148 preoperative clinical variables collected, risk prediction models for eight major postoperative morbidities were created using 80% (8715 patients) of the study population and validated using the remaining 20% (2147 patients) of the patients.

RESULTS

The mortality rate was 3.1% and postoperative morbidity was observed in 42.6% of the patients. The c-statistics of the eight risk models established by the training set were surgical site infection (0.564), anastomotic leakage (0.531), need for transfusion (0.636), blood loss >1000 mL (0.644), pneumonia (0.632), unplanned intubation (0.607), prolonged mechanical ventilation over 48 hours (0.614), and sepsis (0.618) in the validation analysis.

CONCLUSIONS

Risk prediction models for postoperative morbidity after esophagectomy using the population-based large database showed relatively fair performance. The current models may offer baseline information for risk stratification in clinical decision makings and help select more suitable surgical and nonsurgical treatment options and future clinical studies.

Asymmetric Synthesis of 4,4-(Difluoro)glutamic Acid via Chiral Ni(II)-Complexes of Dehydroalanine Schiff Bases. Effect of the Chiral Ligands Structure on the Stereochemical Outcome

Four differently substituted chiral Ni(II)-complexes of dehydroalanine Schiff base were prepared and reacted with BrCF2COOEt/Cu under the standard reaction conditions. The observed diastereoselectivity was found to depend on the degree and pattern of chlorine substitution for hydrogen in the structure of the dehydroalanine complexes. The unsubstituted complex gave the ratio of diastereomers (S)(2S)/(S)(2R) of 66/34. On the other hand, introduction of chlorine atoms in the strategic positions on the chiral ligands allowed to achieve a practically attractive diastereoselectivity of (∼98.5/1.5). Diastereomerically pure major product was disassembled to prepare 9-fluorenylmethyloxycarbonyl (Fmoc) derivative of (S)-4,4-difluoroglutamic acid.

Preparative Method for Asymmetric Synthesis of (S)-2-Amino-4,4,4-trifluorobutanoic Acid

Enantiomerically pure derivatives of 2-amino-4,4,4-trifluorobutanoic acid are in great demand as bioisostere of leucine moiety in the drug design. Here, we disclose a method specifically developed for large-scale (>150 g) preparation of the target (S)-N-Fmoc-2-amino-4,4,4-trifluorobutanoic acid. The method employs a recyclable chiral auxiliary to form the corresponding Ni(II) complex with glycine Schiff base, which is alkylated with CF3-CH2-I under basic conditions. The resultant alkylated Ni(II) complex is disassembled to reclaim the chiral auxiliary and 2-amino-4,4,4-trifluorobutanoic acid, which is in situ converted to the N-Fmoc derivative. The whole procedure was reproduced several times for consecutive preparation of over 300 g of the target (S)-N-Fmoc-2-amino-4,4,4-trifluorobutanoic acid.

Development of Hamari Ligands for Practical Asymmetric Synthesis of Tailor-Made Amino Acids

Enantiomerically pure tailor-made amino acids are in extremely high demand in nearly every sector of the health-related industries. In particular, the rapidly growing number of amino-acid-based pharmaceuticals calls for the development of advanced synthetic approaches featuring practicality and commercial viability. Here we provide a brief summary of the development of axially chiral tridentate Hamari ligands and their application for general asymmetric synthesis of various structural types of amino acids. The methodological diversity includes: dynamic kinetic resolution and (S)-/(R)-interconversion of unprotected amino acids and homologation of nucleophilic glycine equivalents via alkyl halide alkylation reactions as well as multiple-step transformations allowing preparation of polyfunctional and cyclic derivatives. The practicality of these methods is critically discussed.

LC-ESI-MS/MS quantification of carnosine, anserine, and balenine in meat samples

The histidine-containing imidazole dipeptide carnosine and its methylated analogs anserine and balenine are present at high concentrations in vertebrate tissues. Although the physiological functions of the imidazole dipeptides have not been elucidated yet, it has been suggested that they play significant biological roles in animals. Despite increasing interest, few studies have challenged the quantifications of carnosine, anserine, and balenine by a single HPLC run because they have similar retention times. In this study, we developed a method to quantify these imidazole dipeptides in meat samples using an LC-ESI-MS/MS triple-quadrupole mass spectrometer. We improved the liquid chromatographic separation of the imidazole dipeptides by applying a mix-mode column, which provides both normal phase and ion exchange separations, and developed multiple reaction-monitoring of the transitions for quantification of m/z 227 → 110 for carnosine, m/z 241 → 126 for anserine, m/z 241 → 124 for balenine, and m/z 269 → 110 for L-histidyl-L-leucine (internal standard). The established method met all pre-defined validation criteria. Intra- and inter-day accuracy and precision were ±10.0% and ≤14.8%, respectively. The ranges of quantifications were 14.7 ng/mL to 1.5 mg/mL for carnosine, 15.6 ng/mL to 1.6 mg/mL for anserine, and 15.6 ng/mL to 1.6 mg/mL for balenine. In conclusion, the validated method was successfully applied to the quantification of imidazole dipeptides in biological samples without derivatization.

Development and validation of grade-based prediction models for postoperative morbidity in gastric cancer resection using a Japanese web-based nationwide registry

AIM

Gastric cancer is the second leading cause of cancer death worldwide. Surgery is the mainstay treatment for gastric cancer. There are no prediction models that examine the severity of postoperative morbidity. Herein, we constructed prediction models that analyze the risk for postoperative morbidity based on severity.

METHODS

Perioperative data were retrieved from the National Clinical Database in patients who underwent elective gastric cancer resection between 2011 and 2012 in Japan. Severity of postoperative complications was determined by Clavien-Dindo classification. Patients were randomly divided into two groups, the development set and the validation set. Logistic regression analysis was used to build prediction models. Calibration powers of the models were assessed by a calibration plot in which linearity between the observed and predicted event rates in 10 risk bands was assessed by the Pearson R 2 statistic.

RESULTS

We obtained 154 278 patients for the analysis. Prediction models were constructed for grade ≥2, grade ≥3, grade ≥4, and grade 5 in the development set (n = 77 423). Calibration plots of these models showed significant linearity in the validation set (n = 76 855): R 2 = 0.995 for grade ≥2, R 2 = 0.997 for grade ≥3, R 2 = 0.998 for grade ≥4, and R 2 = 0.997 for grade 5 (all: P < 0.001).

CONCLUSION

Prediction models for postoperative morbidity based on grade will provide a comprehensive risk of surgery. These models may be useful for informed consent and surgical decision-making.

Synthesis of a burkholdine analogue containing β-hydroxytyrosine

Synthesis of a β-OHTyr-containing Bk analogue, a cyclic octalipopeptide with antifungal activities, is described. Since β-OHTyr-containing peptides generally are unstable in strong acidic conditions, synthesis of β-HOTyr-containing peptides by SPPS have rarely been reported. To overcome this problem, we found that using distilled TFA removed the protecting groups of side chains of β-OHTyr-containing Bk analogue, which was prepared by Fmoc-SPPS.

Abbreviations: β-OHTyr: β-hydroxytyrosine; β-OHAsn: β-hydroxyasparagine; Bk: burkholdine; FAA: fatty acyl amino acid; β-MeOTyr: β-methoxytyrosine; SPPS: solid phase peptide synthesis; MIC: minimun inhibitory concentration; DMF: dimethyl formamide; DIPEA: diisopropylethylamine; DIPC: diisopropylcarbodiimide; HOBt: 1-hydroxybenzotriazole; Fmoc: 9-fluorenylmethyloxycarbonyl; HFIP: 1,1,1,3,3,3-hexafluoropropan-2-ol; TFA: trifluoroacetic acid; LAP: N-lauryl −3-amino-4-carbamolypropanoic acid; HPLC: high performance liquid chromatography; ESI-TOFMS: electrospray ionization-time of flight mass spectrometry; Bn: benzyl; Boc: t-butyloxycatbonyl; 2-CTC: 2-chlorotritylchloride.

Surgical outcomes of gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2017

BACKGROUND

The Japanese National Clinical Database (NCD) is a large-scale, nationwide, web-based data entry system that is linked to the surgical board certification system and covers almost all surgical cases carried out in Japan.

AIM

To evaluate outcomes according to the gastroenterological section of the NCD.

METHODS

The 115 surgical procedures stipulated by the "Training Curriculum for Board-Certified Surgeons in Gastroenterology" were registered from 2011 to 2017. The number of surgeries, preoperative comorbidities, and short-term outcomes were compared between registration periods.

RESULTS

In total, 3 818 414 cases have been registered. More than 70% of all surgeries were carried out at certified institutions. The annual number of cases has been increasing year after year, and the aged population has also been increasing. Although the rates of preoperative comorbidities and postoperative complications have been increasing, the postoperative mortality rate has remained relatively low; in 2017, the 30-day mortality rate was 1.0% among those who underwent esophagectomy, 0.7% among those who underwent distal gastrectomy, 1.1% among those who underwent total gastrectomy, 1.3% among those who underwent right hemicolectomy, 0.5% among those who underwent low anterior resection, 1.3% among those who underwent hepatectomy, and 1.3% among those who underwent pancreaticoduodenectomy. The annual rate of endoscopic surgery dramatically increased over 7 years between 2011 and 2017, especially for low anterior resection (29.5%-62.6%) and esophagectomy (31.0%-56.1%).

CONCLUSION

This database is expected to ensure the quality of the board-certification system and surgical outcomes in gastroenterological surgery.

Abstract 4028: Tenascin C in gastric cancer stroma is a predictive marker for postoperative prognosis

Background: Tenascin C, a glycoprotein in the extracellular matrix is reportedly associated with poor clinical outcome in several malignancies. We have previously reported that tenascin C in colorectal cancer stroma is a predictive marker for liver metastasis (Br J Cancer 117:1360-70, 2017). In this study, we evaluated the clinicopathological and prognostic significance of tenascin C expression in gastric cancer stroma.

Materials and methods: Expression levels of tenascin C protein were immunohistochemically analyzed in 176 primary gastric cancer samples. Tenascin C staining intensity and relativity were classified into four scores and two groups, respectively. The correlation of the tenascin C staining intensity and relativity with clinicopathological factors, postoperative overall survival (OS) and disease-free survival (DFS) were analyzed.

Results: There were positive correlations between the tenascin C staining intensity or relativity and tumor depth, lymphatic invasion, venous invasion, lymph node metastasis, pathological stage, high preoperative carcinoembryonic antigen (CEA)&gt;5ng/ml, and high preoperative carbohydrate antigen (CA19-9) &gt;37U/ml. Multivariate analysis revealed that high tenascin C staining intensity significantly correlated with tumor invasion into the muscularis propria (p=0.015) and venous invasion (p=0.042), and that high tenascin C staining relativity correlated with venous invasion (p=0.013). Gastric cancer patients with high tenascin C staining intensity had significantly shorter postoperative OS (p&lt;0.001), whereas tenascin C staining relativity did not correlate with postoperative OS (p=0.05). High tenascin C staining intensity and relativity significantly correlated with shorter postoperative DFS (p&lt;0.001 and 0.005, respectively). Cox proportional hazard model identified high tenascin C staining intensity as an independent prognostic factor for poor postoperative OS (hazard ratio (HR): 13.16, 95% confidence interval (CI): 1.362-125.000, p=0.026) and DFS (HR: 6.02, 95%CI: 1.538-23.810, p=0.010).

Conclusions: Tenascin C protein expression in primary tumor stroma was identified as a predictive marker for postoperative prognosis in patients with gastric cancer.

Citation Format: Hirotoshi Kikuchi, Tomohiro Murakami, Sanshiro Kawata, Amane Hirotsu, Tomohiro Matsumoto, Yusuke Ozaki, Yoshihiro Hiramatsu, Kinji Kamiya, Yoshifumi Morita, Takanori Sakaguchi, Hiroyuki Konno, Hiroya Takeuchi. Tenascin C in gastric cancer stroma is a predictive marker for postoperative prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4028.

Risk calculator for predicting postoperative pneumonia after gastroenterological surgery based on a national Japanese database

BACKGROUND

The aim of the present study was to develop a risk calculator predictive of postoperative pneumonia in patients undergoing gastroenterological surgery.

METHODS

We analyzed data from 382 124 patients undergoing eight main gastroenterological surgeries between 2011 and 2013 using the National Clinical Database in Japan. A risk model was developed using multivariate logistic regression analysis with patient data from 2011 to 2012 (n = 247 604) and validated using data from 2013 (n = 134 520).

RESULTS

Pneumonia was observed in 11 105 patients (2.9%). After the input of significant primary disease and surgical procedures, 18 patient characteristics including gender, chronic obstructive pulmonary disease, sepsis, and need for any assistance in the activities of daily living, six laboratory parameters, and two intraoperative factors were used for risk calculation. Area under the receiver-operating characteristic curve was 0.822 (95% confidence interval, 0.817-0.826) in the derivation group and 0.826 (0.819-0.832) in the validation group.

CONCLUSION

The risk calculator accurately predicted the occurrence of pneumonia following gastroenterological surgery.

Construction of Cellulose Binding Domain Fusion FMN-Dependent NADH-Azoreductase and Glucose 1-Dehydrogenase for the Development of Flow Injection Analysis with Fusion Enzymes Immobilized on Cellulose

The cellulose binding domain (CBD) of cellulosome-integrating protein A from Clostridium thermocellum NBRC 103400 was genetically fused to FMN-dependent NADH-azoreductase (AZR) and glucose 1-dehydrogenase (GDH) from Bacillus subtilis. The fusion enzymes, AZR-CBD and CBD-GDH, were expressed in Escherichia coli Rosetta-gami B (DE3). The enzymes were purified from cell-free extracts, and the specific activity of AZR-CBD was 15.1 U/mg and that of CBD-GDH was 22.6 U/mg. AZR-CBD and CBD-GDH bound strongly to 0.5 % swollen cellulose at approximately 95 and 98 % of the initial protein amounts, respectively. After immobilization onto the swollen cellulose, AZR-CBD and CBD-GDH retained their catalytic activity. Both enzymes bound weakly to 0.5 % microcrystalline cellulose, but the addition of a high concentration of microcrystalline cellulose (10 %) improved the binding rate of both enzymes. A reactor for flow injection analysis was filled with microcrystalline cellulose-immobilized AZR-CBD and CBD-GDH. This flow injection analysis system was successfully applied for the determination of glucose, and a linear calibration curve was observed in the range of approximately 0.16–2.5 mM glucose, with a correlation coefficient, r, of 0.998.

Quantitative analysis of γ-glutamylpeptides by liquid chromatography-mass spectrometry and application for γ-glutamyltransferase assays

γ-Glutamylpeptides are largely produced via the action of γ-glutamylcysteine synthetase or γ-glutamyltransferase (GGT). GGT transfers the γ-glutamyl moiety from glutathione (GSH) and other γ-glutamyl compounds to amino acids, peptides, or water. A conventional GGT assay employs a synthetic donor substrate, which facilitates monitoring cleavage activity by means of colorimetric analyses but provides no information on the resulting γ-glutamylpeptides. In this study, we report on the use of liquid chromatography-mass spectrometry (LC-MS) to quantitatively measure the levels of 21 γ-glutamylpeptides including GSH and 45 amino acids, including Cys. Authentic compounds consisting of 17 chemically synthesized and commercially available 4 γ-glutamylpeptides were adopted as references. We applied this method to the characterization of γ-glutamylpeptides in blood plasma and livers of mice that had been treated with an overdose of acetaminophen. The established LC-MS-based assay was found to be useful for characterizing the γ-glutamylation reaction under in vivo and in vitro conditions and was clearly helpful for understanding the physiological significance of the production of γ-glutamylpeptides.

Body weight loss after surgery affects the continuity of adjuvant chemotherapy for pancreatic cancer

BACKGROUND

Postoperative chemotherapy is beneficial for many pancreatic cancer patients. However, some patients require dose reduction or the discontinuation of adjuvant chemotherapy because of adverse treatment-related effects. In this study, we aimed to evaluate two main outcomes. First, we evaluated the clinicopathological factors affecting patient disease-free survival (DFS) and overall survival (OS) following upfront surgery. Second, we evaluated the factors that influence the continuity of adjuvant chemotherapy.

METHODS

Fifty-four patients with resected pancreatic cancer were enrolled. First, we evaluated the clinicopathological factors affecting postoperative survival using the Kaplan-Meier method and Cox regression method. Next, factors affecting the continuity of adjuvant chemotherapy were analyzed using multiple logistic regression analysis.

RESULTS

Univariate and multivariate analyses revealed that positive LN metastasis (HR (95% CI) 6.329 (2.381-16.95); p < 0.001) and relative dose intensity (RDI) < 80% for adjuvant chemotherapy (HR (95% CI) 5.154 (1.761-15.15); p = 0.003) were independent predictive factors for DFS. Regarding OS, extended dissection of the nerve plexus around the superior mesenteric artery (SMA) (HR (95% CI) 4.504 (1.721-11.76); p = 0.002), positive microscopic surgical margin (HR (95% CI) 5.565 (1.724-17.96); p = 0.004), and adjuvant chemotherapy of RDI < 80% (HR (95% CI) 3.534 (1.135-2.667); p = 0.029) were also independent predictive factors. Moreover, the level of RDI significantly correlated with DFS and OS. Multiple logistic regression analysis revealed that low RDI was significantly associated with postoperative body weight loss (BWL) ≥ 10%.

CONCLUSIONS

The following factors were significantly associated with poor survival: extended dissection of the nerve plexus around the SMA, lymph node metastasis, residual tumor, and RDI of the adjuvant chemotherapy. Patient's prognosis with adjuvant chemotherapy of RDI < 80% was worse. BWL ≥10% was the most important factor affecting the continuity of adjuvant chemotherapy. Perioperative nutritional intervention is necessary for patients who receive adjuvant chemotherapy for advanced pancreatic cancer.

Current status of site-specific cancer registry system for the clinical researches: aiming for future contribution by the assessment of present medical care

BACKGROUND

The current status of site-specific cancer registry has not been elucidated, but sufficient system is found in some societies. The purpose of this study was to clear the present condition of site-specific cancer registries in Japan and to suggest for the improvement.

METHODS

The questionnaire was conducted by the study group of the Ministry of Health, Labor, and Welfare. It consisted of 38 questions, conflicts of interest, clinical research method, informed consent and funding for registry. We distributed this questionnaire to 28 academic societies, which had published the clinical practice guideline(s) assessed under Medical Information Network Distribution Service (MINDS).

RESULTS

The concept of the importance in assessment for medical quality by the data of the site-specific cancer registry was in good consensus. But the number of the society with the mature registry was limited. The whole-year registry with the scientific researches in the National Clinical Database (NCD) and in the Translational Research Informatics Center (TRI) might seem to be in success, because assured enhancement may be estimated. Now, academic societies have the structural factors, i.e., the financial limitation in the registry maintenance and the data analysis, and in the difficulty of employment of the researchers with skill and talent.

CONCLUSIONS

To manage the site-specific cancer registry effectively, the scientific registry system will be essentially important. Each academic society had much experienced highly qualified clinical researches in past. Accordingly, the scientific suggestion and co-operation should be of great importance for the improvement.

Rapid recurrence of primary gastric choriocarcinoma after complete resection

•

A 78-year-old man was diagnosed with stage cIB primary gastric choriocarcinoma.

•

Total gastrectomy with spleen-preserving D2 lymphadenectomy was performed.

•

Early recurrence was diagnosed 3 months postoperatively.

•

The patient underwent a standard nongestational choriocarcinoma chemotherapy.

Introduction

Primary gastric choriocarcinoma (PGC) is a rare and rapidly invasive tumor. We report a case of PGC diagnosed by endoscopic biopsy and treated with gastrectomy and chemotherapy.

Presentation of case

A 78-year-old man was referred to our hospital because esophagogastroduodenoscopy showed a tumor at the fornix of the stomach. Pathologic examination of biopsy specimens revealed choriocarcinoma. Abdominal computed tomography (CT) revealed no enlarged abdominal lymph nodes or distant metastases. Robot-assisted total gastrectomy with spleen-preserving D2 lymphadenectomy was performed on the basis of a diagnosis of cT2N0M0, stage cIB PGC. The pathologic diagnosis was pT2, ly0, v1, pN0, PM0, DM0, stage pIB PGC. The postoperative course was uneventful, and the patient was followed carefully without adjuvant chemotherapy. Three months after gastrectomy, blood tests indicated that serum β-human chorionic gonadotropin (β-hCG) levels had increased, and CT revealed multiple liver metastases. The patient underwent a standard nongestational choriocarcinoma chemotherapy regimen with etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine. Although β-hCG levels temporarily decreased with chemotherapy, the patient experienced tumor recurrence with ascites and his serological test demonstrated an elevated level of β-hCG (120 ng/mL). The patient died 10 months postoperatively.

Conclusion

We report a case of stage pIB PGC with poor prognosis, recurring at only 3 months postoperatively despite curative surgery and chemotherapy.

Convergent Synthesis of trans-2,6-Disubstituted Piperidine Alkaloid, (-)-iso-6-Spectaline by Palladium-Catalyzed Cyclization

The plant alkaloids, iso-6-spectaline and spectaline, isolated from the Cassia or Senna genera contain a characteristic 2,6-disubstituted piperidin-3-ol scaffold. Although both natural products are reported to exhibit a variety of interesting biological activities, few stereo-selective schemes for the construction of the 2,6-disubstituted scaffold have been reported. Following our previous studies regarding the synthesis of (+)-spectaline, herein we report the first convergent synthesis of (-)-iso-6-spectaline using a cross-metathesis under thermal conditions where the cis-2,6-disubstituted piperidin-3-ol scaffold is condensed with a long alkyl chain containing a terminal olefin. The cis-2,6-disubstituted piperidin-3-ol used in the synthesis was prepared simply via Pd(II)-catalyzed diastereoselective cyclization. It was confirmed that (+)-spectaline, an epimer of (-)-iso-6-spectaline, was selectively synthesized by the cross-metathesis reaction under less intense thermal conditions starting from the same cis-2,6-disubstituted piperidin-3-ol derivative.

Tenascin-C Produced by Intestinal Myofibroblasts Promotes Colitis-associated Cancer Development Through Angiogenesis

BACKGROUND

Colitis-associated cancer (CAC) is one of the prognostic factors in inflammatory bowel disease (IBD), and prevention of CAC is a critical concern for patients with IBD. Component cells of the microenvironment, especially myofibroblasts, are known to affect tumor development, but the role of intestinal myofibroblasts (IMFs) in CAC has not been clarified. Here, we explored the role of IMFs in CAC and sought to identify candidate genes as novel therapeutic targets for the prevention of CAC.

METHODS

We used the azoxymethane (AOM)/dextran sodium sulfate (DSS) model for dysplasia and CAC. Flow cytometry and RNA sequencing (RNA-seq) were performed to obtain an unbiased gene expression profile of IMFs. The transcriptome of significantly differentially expressed genes was analyzed by RNA-seq, quantitative reverse transcriptase polymerase chain reaction, and immunohistochemistry.

RESULTS

Comparison of normal intestinal fibroblasts and IMFs revealed 1045 genes with significantly differential expression. Among them, we focused on tenascin-C (TNC; q = 0.00232, Log2(Fold Change) = 3.87). Tenascin-C gene expression was markedly increased in the dysplasia model compared with control and CAC model (P < 0.05). Tenascin-C protein was barely expressed in normal and nondysplastic mucosa but strongly expressed in the stroma around dysplastic lesions. Moreover, TNC surrounded and enclosed integrin αvβ3-positive microvessels. Administration of ATN-161, an antagonist of αvβ3-integrin, significantly suppressed tumorigenesis of CAC through inhibition of angiogenesis (P < 0.05).

CONCLUSIONS

In the early stages of CAC, TNC produced by IMFs affects tumor development via integrin αvβ3-mediated angiogenesis. Intestinal myofibroblasts might be a novel therapeutic target for preventing CAC.

Improved synthesis of 2,4,6-trialkylpyridines from 1,5-diketoalkanes: the total synthesis of Anibamine

Many pyridine syntheses have been developed to date. In this study, we focused on pyridine synthesis with 1,5-diketone derivatives and hydroxylamine. Treatment of simple 1,5-diketoalkanes and hydroxylamine in basic or acidic conditions gave aldol adducts without any pyridine compounds. However, by screening the reaction conditions, we found that acidic conditions produced via the formation of oxime intermediates derived from 1,5-diketoalkanes allowed the formation of the corresponding pyridine derivatives. This is the first example of 2,4,6-trialkylpyridine synthesis from quite simple 1,5-diketoalkanes. In order to demonstrate the utility of the reaction, we demonstrated the synthesis of pyridine derivatives and the total synthesis of a 6-substituted pyridyl-natural product, anibamine. This was achieved by following the above methodology using a reported compound as the starting material to give the product in 12% yield.

Systematic Analysis of Selective Bactericidal Activity of Fatty Acids against Staphylococcus aureus with Minimum Inhibitory Concentration and Minimum Bactericidal Concentration

Bacterial flora on the skin surface contains Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) which causes rough skin and atopic dermatitis and enhances innate immunity, respectively. In this study, minimum inhibitory concentration (MIC) was evaluated for six saturated fatty acids and two unsaturated fatty acids against S. aureus and S. epidermidis. The antimicrobial behavior in the liquid medium was categorized into three groups. The first was the selective antibacterial activity group comprising myristic acid (C14:0 fatty acid), palmitoleic acid (C16:1 fatty acid), and oleic acid (C18:1 fatty acid) and preferentially displayed antimicrobial activity for S. aureus (group 1). C16:1 fatty acid displayed high antimicrobial activity only for S. aureus. The second was the non-selective antibacterial activity group which displayed antibacterial activity for both Staphylococci (group 2). Caprylic acid (C8:0 fatty acid), capric acid (C10:0 fatty acid), and lauric acid (C12:0 fatty acid) comprised group 2. The third was the nonantibacterial activity group which did not show significant antimicrobial activity (group 3). Bactericidal activities were confirmed for C12:0 fatty acid and C16:1 fatty acid by evaluating the minimum bactericidal concentration (MBC) on the agar medium. C12:0 fatty acid displayed non-selective bactericidal behavior against S. aureus and S. epidermidis when the fatty acid concentration was above 250 μg mL^-1. These findings suggest that C16:1 fatty acid has the potential to be used as a detergent in skin care and medical products because it can selectively kill only S. aureus.

Label-free classification of cells based on supervised machine learning of subcellular structures

It is demonstrated that cells can be classified by pattern recognition of the subcellular structure of non-stained live cells, and the pattern recognition was performed by machine learning. Human white blood cells and five types of cancer cell lines were imaged by quantitative phase microscopy, which provides morphological information without staining quantitatively in terms of optical thickness of cells. Subcellular features were then extracted from the obtained images as training data sets for the machine learning. The built classifier successfully classified WBCs from cell lines (area under ROC curve = 0.996). This label-free, non-cytotoxic cell classification based on the subcellular structure of QPM images has the potential to serve as an automated diagnosis of single cells.

Thiamin transport in Helicobacter pylori lacking the de novo synthesis of thiamin

Helicobacter pylori lacks the genes involved in the de novo synthesis of thiamin, and is therefore a thiamin auxotroph. The PnuT transporter, a member of the Pnu transporter family, mediates the uptake of thiamin across the membrane. In the genome of H. pylori, the pnuT gene is clustered with the thiamin pyrophosphokinase gene thi80. In this study, we found that [³H]thiamin is incorporated into the H. pylori SS1 strain via facilitated diffusion with a Km value of 28 µM. The incorporation of radioactive thiamin was inhibited to some extent by 2-methyl-4-amino-5-hydroxymethylpyrimidine or pyrithiamine, but was largely unaffected by thiamin phosphate or thiamin pyrophosphate. RT-PCR analysis demonstrated that the pnuT and thi80 genes are cotranscribed as a single transcript. The estimated Km value for thiamin in the thiamin pyrophosphokinase activity exerted by the recombinant Thi80 protein was 0.40 µM, which is much lower than the Km value of thiamin transport in H. pylori cells. These findings suggested that the incorporated thiamin from the environment is efficiently trapped by pyrophosphorylation to make the transport directional. In addition, the thiamin transport activity in the pnuT-deficient H. pylori strain was less than 20 % of that in the wild-type strain at extracellular thiamin concentration of 1 µM, but the incorporated scintillation signals of the pnuT-deficient strain with 100 nM [³H]thiamin were nearly at the background level. We also found that the pnuT-deficient strain required 100-times more thiamin to achieve growth equal to that of the wild-type. These findings reflect the presence of multiple routes for entry of thiamin into H. pylori, and PnuT is likely responsible for the high-affinity thiamin transport and serves as a target for antimicrobial agents against H. pylori.

Introducing laparoscopic total gastrectomy for gastric cancer in general practice: a retrospective cohort study based on a nationwide registry database in Japan

BACKGROUND

Although laparoscopic total gastrectomy (LTG) is considered a technically demanding procedure with safety issues, it has been performed in several hospitals in Japan. Data from a nationwide web-based data entry system for surgical procedures (NCD) that started enrollment in 2011 are now available for analysis.

METHODS

A retrospective cohort study was conducted using data from 32,144 patients who underwent total gastrectomy and were registered in the NCD database between January 2012 and December 2013. Mortality and morbidities were compared between patients who received LTG and those who underwent open total gastrectomy (OTG) in the propensity score-matched Stage I cohort and Stage II-IV cohort.

RESULTS

There was no significant difference in mortality rate between LTG and OTG in both cohorts. Operating time was significantly longer in LTG while the blood loss was smaller. In the Stage I cohort, LTG, performed in 33.6% of the patients, was associated with significantly shorter hospital stay but significantly higher incidence of readmission, reoperation, and anastomotic leakage (5.4% vs. 3.6%, p < 0.01). In the Stage II-IV cohort, LTG was performed in only 8.8% of the patients and was associated with significantly higher incidence of leakage (5.7% vs. 3.6%, p < 0.02) although the hospital stay was shorter (15 days vs. 17 days, p < 0.001).

CONCLUSION

LTG was more discreetly introduced than distal gastrectomy, but remained a technically demanding procedure as of 2013. This procedure should be performed only among the well-trained and informed laparoscopic team.

Deletion of uncharacterized domain from α-1,3-glucanase of Bacillus circulans KA-304 enhances heterologous enzyme production in Escherichia coli

α-1,3-Glucanase (Agl-KA) of Bacillus circulans KA-304 consists of an N-terminal discoidin domain (DS1), a carbohydrate binding module family 6 (CBM6), threonine and proline repeats (TP), a second discoidin domain (DS2), an uncharacterized conserved domain (UCD), and a C-terminal catalytic domain. Previously, we reported that DS1, CBM6, and DS2 have α-1,3-glucan-binding activity and contribute to α-1,3-glucan hydrolysis. In this study, UCD deletion mutant (AglΔUCD) was constructed, and its properties were compared with those of Agl-KA. α-1,3-Glucan hydrolyzing, α-1,3-glucan binding, and protoplast-forming activities of AglΔUCD were almost the same as those of Agl-KA. k_cat/K_m values of AgΔUCD and Agl-KA were 11.4 and 11.1 s^-1 mg^-1 mL, respectively. AglΔUCD and Agl-KA exhibited similar characteristics, such as optimal pH, pH stability, optimal temperature, and thermostability. These results suggest that UCD is not α-1,3-glucan-binding and flexible linker domain, and that deletion of UCD does not affect the affinity of N-terminal binding domains and the catalytic action of the C-terminal domain. Subsequently, heterologous UCenzyme productivity of AglΔD in Escherichia coli was compared with that of Agl-KA. The productivity of AglΔUCD was about 4-fold larger than that of Agl-KA after an 8-h induction at 30°C. In the case of induction at 20°C, the productivity of AglΔUCD was also larger than that of Agl-KA. These findings indicate that deletion of only UCD enhances the enzyme productivity in E. coli.

Current status of projects for developing cancer-related clinical practice guidelines in Japan and recommendations for the future

Background

The current status and adoption of cancer-related clinical practice guidelines in Japan has not been elucidated yet. The purpose of this study was to propose roles and suggestions to develop future cancer-related clinical guidelines.

Methods

A questionnaire consisting of four domains with a total of 17 questions was developed. We distributed the questionnaire to 28 specific academic organizations in Japan which have developed any cancer-related clinical practice guidelines and which were funded by the Ministry of Health, Labor, and Welfare.

Results

Most organizations have investigated nationwide dissemination and adoption of clinical practice guidelines. The rate of adoption in clinical practice was estimated at approximately ≥ 70%. However, organizations with smaller budgets reported surveying approximately 60% of the time, whereas the ones with larger budgets reported approximately 100% success in surveying about their guidelines. The presidents of the organizations agreed that a new organization operated directly by the national government was necessary.

Conclusion

In Japan, to develop cancer-related clinical practice guidelines, a study of clinical validation is necessary. Sufficient funds must be available to support the project to maintain and revise the guidelines. Furthermore, legal and ethical issues should be solved before establishing any registry system.

Role of caveolin-1 in hepatocellular carcinoma arising from non-alcoholic fatty liver disease

The molecular features of hepatocellular carcinoma arising from non-alcoholic fatty liver disease (NAFLD-HCC) are not well known. In this study, we investigated the mechanism by which NAFLD-HCC survives in a fat-rich environment. We found that caveolin (CAV)-1 was overexpressed in clinical specimens from NAFLD-HCC patients. HepG2, HLE, and HuH-7 HCC cell lines showed decreased proliferation in the presence of the saturated fatty acids palmitic acid and stearic acid, although only HLE cells expressed high levels of CAV-1. HLE cells treated with oleic acid (OA) showed robust proliferation, whereas CAV-null HepG2 cells showed reduced proliferation and increased apoptosis. CAV-1 knockdown in HLE cells attenuated the OA-induced increase in proliferation and enhanced apoptosis. Liquid chromatography-tandem mass spectrometry analysis revealed that the levels of OA-containing ceramide, a pro-apoptotic factor, were higher in HepG2 and CAV-1-deficient HLE cells than in HLE cells, suggesting that CAV-1 inhibits apoptosis by decreasing the level of OA-containing ceramide. These results indicate that CAV-1 is important for NAFLD-HCC survival in fatty acid-rich environments and is a potential therapeutic target.

Abstract 2588: Label-free classification of live cells using quantitative phase microscopy images for negative selection of circulating tumor cells

Background: Circulating tumor cells (CTCs) are used as a liquid biopsy target in the treatment of cancer patients and are important for personalized medicine. Most CTC detection technologies are based on their surface markers such as EpCAM and cytokeratin. However, those positive selection methodologies appear to count only some CTCs because invasive tumor cells tend to change their surface markers during progression. Because the vast majority of nucleated cells circulating in the bloodstream are white blood cells (WBCs), eliminating WBCs from circulation is an efficient method to purify CTCs by negative selection. In this study, we demonstrate the development of cell recognition by computer vision technologies for pattern recognition based on the morphological features of live cells.

Materials and methods: Blood samples were obtained from healthy volunteers. Five cancer cell lines, SW480, DLD-1, HCT116, Panc-1, and HepG2 were used as CTC models. We applied quantitative phase microscopy (QPM) that detects the small delay of the phase and image optical path lengths and provides quantitative morphological information of live cells with high contrast without staining. WBC recognition algorithm was developed using computer vision technologies for pattern recognition based on the histogram-oriented gradient (HOG) features extracted from QPM images (QPIs) for negative selection of CTCs.

Results: We observed WBCs and five cell line cells by QPM, extracted certain features from the obtained images as training data for pattern recognition, and created an algorithm to differentiate WBCs from cell lines. The obtained algorithm successfully differentiated WBCs from cell lines (AUC=0.98). To simulate WBCs and cell lines with a small and strong change, respectively, in optical thickness (OT) at the center of the cell, we created a homogeneous hemi-ellipsoid model and a heterogeneous hemi-ellipsoid model, respectively. In these models, OT gradually increased from the edge to the center, but fluctuated around the center to simulate intracellular heterogeneity of a cancer cell. Based on these simulations, the classifier was interpreted to recognize intracellular heterogeneity, especially in the center of the cell. Finally, we applied our image recognition methods to QPIs of the cells flowing in the chamber, and properly differentiate WBCs from cell line cells flowing in the chamber (AUC=0.99).

Conclusions: We developed a novel method for label-free image identification of live cells by computer vision technologies for pattern recognition based on the features of QPIs. Our study makes it possible to sort CTCs in a non-cytotoxic manner, thus providing good opportunities for molecular biological approaches to isolate CTCs.

Citation Format: Hirotoshi Kikuchi, Yusuke Ozaki, Amane Hirotsu, Hidenao Yamada, Shigetoshi Okazaki, Tomohiro Murakami, Tomohiro Matsumoto, Yoshihiro Hiramatsu, Kinji Kamiya, Takanori Sakaguchi, Hiroyuki Konno, Hiroya Takeuchi. Label-free classification of live cells using quantitative phase microscopy images for negative selection of circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2588.

Abstract 1067: Tenascin C in colorectal cancer stroma is a predictive marker for liver metastasis and is a potent target of miR-198 as identified by microRNA analysis

Background: Liver metastasis in colorectal cancer (CRC) is still one of the major determinants of survival. Tumor stroma has important roles in the development of colorectal cancer (CRC) metastasis. MicroRNAs (miRNAs) are known to regulate the expression of genes involved in many physiological conditions, including cancer. Previous studies reported important roles of miRNAs in cancer cells in CRC development and metastasis. However, only few studies have focused on miRNA expression in CRC stroma. In this study, we revealed the miRNA expression profiles in tumor stroma by miRNA array analysis using Laser captured microdissection (LCM) to identify miRNAs and their target genes as novel molecular markers involved in CRC liver metastasis.

Methods: Tumor stroma was isolated from formalin-fixed, paraffin-embedded tissues of primary CRCs with or without liver metastasis by LCM, and miRNA expression was analyzed using TaqMan miRNA arrays.

Results: Hierarchical clustering classified 16 CRCs into two groups according to the existence of synchronous liver metastasis. Combinatory target prediction identified tenascin C (TNC) as a predicted target of miR-198, one of the top 10 miRNAs downregulated in tumor stroma of CRCs with synchronous liver metastasis. Immunohistochemical analysis of TNC in 139 primary CRCs revealed that a high staining intensity was correlated with synchronous liver metastasis (P&lt;0.001). TNC staining intensities in the tumor stroma of 83 CRC liver metastases revealed a higher staining in liver metastases than in primary CRCs independently of preoperative chemotherapy. Univariate and multivariate analyses revealed that the TNC staining intensity was an independent prognostic factor to predict postoperative overall survival (P=0.005; n=139) and liver metastasis-free survival (P=0.001; n=128). To evaluate the biological link between miR-198 and TNC, we first checked expression levels of miR-198 in the 16 samples in miRNA array data, and compared them with TNC staining intensities. The CRC samples expressing miR-198 tended to have lower levels of TNC expression in comparison with those without miR-198 expression, although the difference was not statistically significant (P=0.237). Next, we transfected a miR-198 mimic or a miR-198 inhibitor into SW620 human colon cancer cells and CCD-18Co human colon fibroblast cells and analyzed the expression change of TNC protein by western blotting. The relative protein expression of TNC was suppressed by treatment with the miR-198 mimic and increased by miR-198 inhibitor.

Conclusions: Alterations of miRNAs in CRC stroma appear to form a metastasis-permissive environment that can elevate TNC to promote liver metastasis. TNC in primary CRC stroma has the potential to be a novel biomarker to predict postoperative prognosis.

Citation Format: Tomohiro Murakami, Hirotoshi Kikuchi, Hisahito Ishimatsu, Sanshiro Kawata, Amane Hirotsu, Tomohiro Matsumoto, Yusuke Ozaki, Yoshihiro Hiramatsu, Kinji Kamiya, Megumi Baba, Satoshi Baba, Masatoshi Kitagawa, Takanori Sakaguchi, Hiroyuki Konno, Hiroya Takeuchi. Tenascin C in colorectal cancer stroma is a predictive marker for liver metastasis and is a potent target of miR-198 as identified by microRNA analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1067.