Efficacy of chemotherapy for patients with metastatic or recurrent pancreatic adenosquamous carcinoma: A multicenter retrospective analysis.

BACKGROUND/OBJECTIVES: Pancreatic adenosquamous carcinoma (PASC) is a rare variant of pancreatic ductal adenocarcinoma (PDAC). The usual treatment for metastatic or recurrent PASC is systemic chemotherapy in accordance with the PDAC treatment strategy. This study aimed to investigate the efficacy of chemotherapy, especially the benefit of recent combination therapies, in patients with metastatic or recurrent PASC. METHODS: We conducted a multicenter retrospective analysis of 116 patients with metastatic or recurrent PASC treated with first-line chemotherapy between April 2001 and December 2017 at 24 Japanese institutions. RESULTS: Combination chemotherapies included gemcitabine + nab-paclitaxel (GnP, n = 28), fluorouracil/leucovorin + irinotecan + oxaliplatin (FFX, n = 10), gemcitabine + S-1 (GS, n = 10), and others (n = 9). Monotherapies included gemcitabine (n = 51) and S-1 (n = 8). The median overall survival (OS) was 6.5, 7.3, and 4.3 months for the whole cohort, the combination therapy group, and the monotherapy group, respectively. Multivariate analysis indicated that combination therapy showed a better trend in OS than monotherapy (hazard ratio = 0.68; 95% confidence interval, 0.38-1.20). GnP or FFX were selected in 58.7% of patients after FFX was approved in Japan, and revealed a median OS, median progression-free survival, and objective response rate of 7.3 months, 2.8 months, and 26.9% in GnP and 7.2 months, 2.3 months, and 20.0% in FFX respectively. CONCLUSIONS: This study suggests that combination therapy may be more effective than monotherapy. GnP and FFX showed similar and clinically meaningful efficacy for patients with metastatic or recurrent PASC.

Rational design of a disulfide bridge increases the thermostability of microbial transglutaminase.

Microbial transglutaminase (MTG) has numerous industrial applications in the food and pharmaceutical sectors. Unfortunately, the thermostability of MTG is too low to tolerate the desired conditions used in many of these commercial processes. In a previous study, we used protein engineering to improve the thermostability of MTG. Specifically, we generated a T7C/E58C mutant of MTG from Streptomyces mobaraensis that displayed enhanced resistance to thermal inactivation. In this study, a rational structure-based approach was adopted to introduce a disulfide bridge to further increase the thermostability of MTG. In all, four new mutants, each containing a novel disulfide bond, were engineered. Of these four mutants, D3C/G283C showed the most promising thermostability with a significantly higher ∆T50 (defined as the temperature of incubation at which 50% of the initial activity remains) of + 9 °C by comparison to wild-type MTG. Indeed, D3C/G283C combined enhanced thermostability with a 2.1-fold increased half-life at 65 °C compared with the wild-type enzyme. By structure-based rational design, we were able to create an MTG variant which might be useful for expanding the scope of application in food. KEY POINTS: • Microbial transglutaminase (MTG) is an enzyme used in many food applications • The applicability of MTG to various industrial processes other than the food sector is being investigated • Improvement of thermostability was confirmed for the disulfide bridge mutant D3C/G283C.

Liver biopsy technique in the era of genomic cancer therapies: a single-center retrospective analysis.

BACKGROUND: With the evolution of personalized medicine in the field of oncology, which includes optimal treatment selection using next-generation sequencing-based companion diagnostic systems and tumor-agnostic treatments according to common biomarkers, a liver tumor biopsy technique that can obtain a sufficient specimen volume must be established. The current study aimed to evaluate the safety and availability of a liver tumor biopsy technique with multiple puncture sites made using a coaxial introducer needle and embolization with gelatin sponge particles. METHODS: Patients with primary or metastatic liver cancer who underwent liver tumor biopsies with puncture tract embolization using gelatin sponge (Spongel®) from October 2019 to September 2020 were included in the study. The complication and diagnostic rates were evaluated, and whether the specimen volume was sufficient for Foundation® CDx was investigated. RESULTS: In total, 96 patients were enrolled in this analysis. The median total number of puncture times per patient was 3 (range 1-8). The pathological diagnostic rate was 79.2%. Using the FoundationOne® CDx, specimens with a sufficient volume required for genomic medicine were collected in 84.9% of patients. The incidence rate of bleeding was 4.2% (n = 4), and only one patient presented with major bleeding requiring transfusion. CONCLUSIONS: Liver biopsy with puncture tract embolization using a gelatin sponge may be safe and effective for collecting specimens with a volume sufficient for modern cancer treatments.

Acquisition of mesenchymal-like phenotypes and overproduction of angiogenic factors in lenvatinib-resistant hepatocellular carcinoma cells.

Lenvatinib is one of the first-line drugs for patients with advanced hepatocellular carcinoma (HCC) and widely used around the world. However, the mechanisms underlying resistance to lenvatinib remain unclear. In this study, we conducted characteristic analyses of lenvatinib-resistant HCC cells. Lenvatinib-resistant HCC cell lines were established by exposure to serially escalated doses of lenvatinib over 2 months. The biological characteristics of these cells were examined by in vitro assays. To investigate the cytokine profile of lenvatinib-resistant HCC cells, the supernatant derived from lenvatinib-resistant Huh7 cells was subjected to nitrocellulose membrane-based sandwich immunoassay. Both activation of the MAPK/MEK/ERK signaling pathway and upregulation of epithelial mesenchymal transition markers were observed in lenvatinib-resistant cells. Concordant with these findings, proliferation and invasion abilities were enhanced in these cells compared with control cells. Screening of a cytokine array spotted with 105 different antibodies to human cytokines enabled us to identify 16 upregulated cytokines in lenvatinib-resistant cells. Among them, 3 angiogenic cytokines: vascular endothelial growth factor (VEGF), platelet-derived growth factor-AA (PDGF-AA), and angiogenin, were increased significantly. Conditioned medium from lenvatinib-resistant cells accelerated tube formation of human umbilical vein cells. In conclusion, lenvatinib-resistant HCC cells were characterized by enhanced proliferation and invasion abilities. These findings might contribute to the establishment of new combination therapies with lenvatinib.

Effect of introducing a disulfide bridge on the thermostability of microbial transglutaminase from Streptomyces mobaraensis.

Microbial transglutaminase (MTG) has been used extensively in academic research and the food industry through cross-linking or posttranslational modification of proteins. In our previous paper, the activity-increased MTG mutants were obtained by means of rational mutagenesis and random mutagenesis coupled with the newly developed screening system. In addition, the improvement of heat resistance of MTG is needed to expand further its industrial applications. Here, a structure-based rational enzyme engineering approach was applied to improve the thermostability of MTG by introducing an artificial disulfide bridge. As a result of narrowing down candidates using a rational approach, we successfully engineered a disulfide bridge into the N-terminal region of MTG by substituting Thr-7 and Glu-58 with cysteine. The T7C/E58C mutant was observed to have a de novo disulfide bridge and showed an increased melting temperature (Tm value) of 4.3 °C with retained enzymatic activity. To address the benefit-gained reason, we focused on the Cß temperature factor of the amino-acid residues that might form a disulfide bridge in MTG. Introducing the disulfide bridge had no remarkable effect on the mutant aiming to stabilize the high temperature factor. On the other hand, the mutation was effective on the relatively stable region. The introduction of a disulfide bridge may therefore be effective to stabilize further the relatively stable part. This finding is considered to be useful for the rational design of mutants aiming at heat resistance of proteins.Key Points• Microbial transglutaminase (MTG) is used as a binder in the food industry.• MTG has the potential for use in the manufacturing of various commercial materials.• Enhanced thermostability was observed for the disulfide bridge mutant, T7C/G58C.

Sequential therapy with sorafenib and regorafenib for advanced hepatocellular carcinoma: a multicenter retrospective study in Japan.

Background Conversion from sorafenib to regorafenib is primarily an evidence-based treatment strategy in patients with advanced hepatocellular carcinoma (HCC). This study aimed to assess the safety and efficacy of sequential therapy with sorafenib and regorafenib in patients with advanced HCC by analysis of outcomes in clinical practice with the aim to complement phase III findings. Methods The medical records of patients with advanced HCC receiving regorafenib were retrieved to collect data on sorafenib administration at seven Japanese institutions. Radiological responses and adverse events were evaluated using the Response Evaluation Criteria in Solid Tumors version 1.1 and the Common Terminology Criteria for Adverse Events version 4.0, respectively. Results Before March 2018, 44 patients were administered regorafenib for advanced HCC. The median sorafenib treatment duration was 8.4 months. The most common adverse events were similar to those reported by the RESORCE trial. The median overall survival (OS) was 17.3 months (95% confidence interval [CI] 11.4-22.9), and 17 of 37 patients (45.9%) discontinued regorafenib and received sequential systemic therapy after regorafenib. These patients had significantly longer OS than those who were treated by the best supportive care or sub-optimal therapy (not reached versus 8.7 months [95% CI 5.8-11.7]; P < 0.001). Conclusion The results based on Japanese clinical practices verified the tolerability of regorafenib in advanced HCC. Major regorafenib-associated adverse events were similar to those related to sorafenib. OS was significantly longer than expected, which might be associated with the sequential systemic therapies after regorafenib, mainly lenvatinib.

Long-term administration of Tolvaptan to patients with decompensated cirrhosis.

Aim: Tolvaptan, an oral vasopressin-2 antagonist, sometimes improves hepatic edema including ascites in patients with decompensated cirrhosis. In this study, we examined the effectiveness and survival advantage in patients with the long-term administration of tolvaptan. Methods: A total of 115 patients with refractory ascites who were treated with tolvaptan were retrospectively analyzed based on their clinical records. Patients with a decrease in body weight of ≥1.5 kg from the baseline on day 7 were determined as responders. Re-exacerbation was defined as a return to the baseline BW, dose escalation of conventional diuretics, or abdominal drainage. Results: Of the 115 patients, 84 were included in this analysis. Response to tolvaptan treatment was observed in 55 out of the 84 patients (65.5%), with a mean weight reduction of 2.52 kg. Multivariate analyses demonstrated that body mass index (≥24) and urinary specific gravity (≥1.018) were significant predictors of the response to tolvaptan. However, cumulative re-exacerbation rates in responders at 6 and 12 months were 42.4 and 60.1%, respectively. Child-Pugh (classification C), HCC complication, and serum sodium levels (≥133 mEq/L) were determined as independent prognostic factors impacting overall survival (OS). Although there were no significant differences in OS between tolvaptan responders and non-responders, the responders without re-exacerbation within 3 months showed significantly longer OS than those with re-exacerbation within 3 months. Conclusion: A persistent therapeutic response, but not early response to tolvaptan, was associated with favorable survival of decompensated cirrhotic patients.

A randomized placebo-controlled trial of prophylactic dexamethasone for transcatheter arterial chemoembolization.

This randomized, double-blind, placebo-controlled trial evaluated dexamethasone efficacy at preventing fever, anorexia, and nausea/vomiting, the most frequent adverse events of transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). Child-Pugh class A/B patients with HCC and no macrovascular invasion/extrahepatic metastases were randomly assigned to either a dexamethasone regimen (day 1, intravenous dexamethasone [20 mg] and granisetron [3 mg] before TACE; days 2 and 3, intravenous dexamethasone [8 mg]) or a control regimen (day 1, intravenous placebo [saline] and granisetron [3 mg]; days 2 and 3, intravenous placebo). The primary endpoint was complete response, defined as the absence of grade ≥1 fever, anorexia, or nausea/vomiting according to the Common Terminology Criteria for Adverse Events (version 4.0) and no use of rescue therapy for 120 hours after TACE. A total of 120 patients between October 2010 and June 2013 were randomly assigned to treatment groups. Overall the complete response rate was greater with the dexamethasone regimen than with the control regimen (47.5%, 95% confidence interval 34.3%-60.9%, versus 10.2%, 95% confidence interval 3.8%-20.8%; P < 0.001). Cumulative incidences of fever, anorexia, and nausea/vomiting were higher in the control regimen group compared with the dexamethasone group (P < 0.001, P < 0.001, and P = 0.095, respectively). The dexamethasone regimen was generally well tolerated by HCC patients including those with well-controlled diabetes mellitus and those with hepatitis B virus infection. Conclusion: The dexamethasone regimen was more effective than the control regimen at preventing TACE-induced fever, anorexia, and nausea/vomiting in patients with HCC. (Hepatology 2018;67:575-585).

Serum fibroblast growth factor 19 serves as a potential novel biomarker for hepatocellular carcinoma.

BACKGROUND: Abnormal autocrine fibroblast growth factor 19 (FGF19) production has been observed in several types of cancers, including hepatocellular carcinoma (HCC). In this study, we investigated the potential of serum FGF19 as a novel tumor marker of HCC based on a sandwich enzyme-linked immunosorbent assay (ELISA). METHODS: The serum FGF19 levels of 304 patients with HCC was measured by ELISA. The serum levels of existing markers, including alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) were determined by chemiluminescence enzyme immunoassay. Both diagnostic value of FGF19 and its changes after curative ablation therapy was further examined. RESULTS: The median FGF19 levels in controls, chronic liver disease patients, and primary HCC patients, were 78.8 pg/mL, 100.1 pg/mL, and 214.5 pg/mL, respectively. The subsequent receiver operating characteristic curves (ROC) successfully determined an optimal cut-off value of 200.0 pg/mL. The area under the ROC curve (AUC) of FGF19 for HCC detection was comparable to those of AFP and DCP. Of importance, FGF19 showed higher sensitivity for the detection of small HCC (solitary cancer with diameter < 20 mm) than those of existing markers. In addition, 43 out of 79 cases (54.4%) with normal AFP and DCP (so-called "double negative HCC") exhibited serum FGF19 level ≥ 200 pg/mL. In 45 HCC patients treated with curative ablation therapy, serum FGF19 levels changed from 257.4 pg/mL to 112.0 pg/mL after the treatment. CONCLUSION: Our findings reveal that FGF19 can be a potential novel biomarker for HCC. Although FGF19 is not necessarily a substitute for existing markers, it may help improve the prognosis in HCC patients owing to its resourceful use in various aspects of HCC management and treatment.

Incidence and hemodynamic feature of risky esophageal varices with lower hepatic venous pressure gradient.

Background: To examine the incidence of cirrhosis patients with high-risk esophageal varices (EV) who show hepatic venous pressure gradient (HVPG) < 10 mmHg and to identify their hemodynamic features. Methods: This prospective study consisted of 110 cirrhosis patients with EV, all with the candidate for primary or secondary prophylaxis. Sixty-one patients had red sign, and 49 patients were bleeders. All patients underwent both Doppler ultrasound and HVPG measurement. Results: There were 18 patients (16.4%) with HVPG < 10 mmHg. The presence of venous-venous communication (VVC) was more frequent in patients with HVPG < 10 mmHg (10/18) than in those with HVPG ≥ 10 mmHg (19/92; p = 0.0021). The flow volume in the left gastric vein (LGV) and the incidence of red sign were higher in the former (251.9 ± 150.6 mL/min; 16/18) than in the latter (181 ± 100.5 mL/min, p = 0.02; 45/92; p = 0.0018). The patients with red sign had lower HVPG (13.3 ± 4.5) but advanced LGV hemodynamics (velocity 13.2 ± 3.8 cm/s; flow volume 217.5 ± 126.6 mL/min), whereas those without red sign had higher HVPG (16.2 ± 4.6, p = 0.001) but poorer LGV hemodynamics (10.9 ± 2.3, p = 0.002; 160.1 ± 83.1, p = 0.02). Conclusion: Patients with high-risk EV with HVPG < 10 mmHg showed 16.4% incidence. Although low HVPG may be underestimated by the presence of VVC, the increased LGV hemodynamics compensates for the severity of portal hypertension, which may contribute to the development of red sign.

Conductance of P2X4 purinergic receptor is determined by conformational equilibrium in the transmembrane region.

Ligand-gated ion channels are partially activated by their ligands, resulting in currents lower than the currents evoked by the physiological full agonists. In the case of P2X purinergic receptors, a cation-selective pore in the transmembrane region expands upon ATP binding to the extracellular ATP-binding site, and the currents evoked by α,ß-methylene ATP are lower than the currents evoked by ATP. However, the mechanism underlying the partial activation of the P2X receptors is unknown although the crystal structures of zebrafish P2X4 receptor in the apo and ATP-bound states are available. Here, we observed the NMR signals from M339 and M351, which were introduced in the transmembrane region, and the endogenous alanine and methionine residues of the zebrafish P2X4 purinergic receptor in the apo, ATP-bound, and α,ß-methylene ATP-bound states. Our NMR analyses revealed that, in the α,ß-methylene ATP-bound state, M339, M351, and the residues that connect the ATP-binding site and the transmembrane region, M325 and A330, exist in conformational equilibrium between closed and open conformations, with slower exchange rates than the chemical shift difference (<100 s(-1)), suggesting that the small population of the open conformation causes the partial activation in this state. Our NMR analyses also revealed that the transmembrane region adopts the open conformation in the state bound to the inhibitor trinitrophenyl-ATP, and thus the antagonism is due to the closure of ion pathways, except for the pore in the transmembrane region: i.e., the lateral cation access in the extracellular region.

Multicenter retrospective analysis of systemic chemotherapy for unresectable combined hepatocellular and cholangiocarcinoma.

We conducted a multicenter retrospective analysis to evaluate the efficacy of systemic chemotherapy for unresectable combined hepatocellular and cholangiocarcinoma. We enrolled 36 patients with pathologically proven, unresectable combined hepatocellular and cholangiocarcinoma treated with systemic chemotherapy. The log-rank test determined the significance of each prognostic factor. Elevated alpha-fetoprotein, carcinoembryonic antigen and carbohydrate antigen 19-9 levels were observed in 58.3%, 16.7% and 38.9% of patients, respectively. First-line chemotherapy included platinum-containing regimens consisting of gemcitabine/cisplatin (n = 12) and fluorouracil/cisplatin (n = 11), sorafenib (n = 5) and others (n = 8). The median overall and progression-free survival times were 8.9 and 2.8 months, respectively, with an overall response rate of 5.6%. Prognostic factors associated with negative outcomes included poor performance status, no prior primary tumor resection, a Child-Pugh class of B, and elevated carcinoembryonic antigen levels with a hazard ratio of 2.25, 2.48, 3.25 and 2.84 by univariate analysis, respectively. The median overall survival times of the gemcitabine/cisplatin, fluorouracil/cisplatin, sorafenib and other groups were 11.9, 10.2, 3.5 and 8.1 months, respectively. Multivariate analysis revealed that the overall survival of patients within the sorafenib monotherapy group was poor compared with platinum-containing regimens (HR: 15.83 [95% CI: 2.25-111.43], P = .006). All 7 patients in the sorafenib group had progressive disease, including 2 patients with second-line therapy. In conclusion, the platinum-containing regimens such as gemcitabine/cisplatin were associated with more favorable outcomes than sorafenib monotherapy for unresectable combined hepatocellular and cholangiocarcinoma.

Deuteration and selective labeling of alanine methyl groups of ß2-adrenergic receptor expressed in a baculovirus-insect cell expression system.

G protein-coupled receptors (GPCRs) exist in equilibrium between multiple conformations, and their populations and exchange rates determine their functions. However, analyses of the conformational dynamics of GPCRs in lipid bilayers are still challenging, because methods for observations of NMR signals of large proteins expressed in a baculovirus-insect cell expression system (BVES) are limited. Here, we report a method to incorporate methyl-13C1H3-labeled alanine with > 45% efficiency in highly deuterated proteins expressed in BVES. Application of the method to the NMR observations of ß2-adrenergic receptor in micelles and in nanodiscs revealed the ligand-induced conformational differences throughout the transmembrane region of the GPCR.

Characteristics of patients with sorafenib-treated advanced hepatocellular carcinoma eligible for second-line treatment.

Background Regorafenib has been investigated for its efficacy and safety as a second-line treatment in patients with advanced hepatocellular carcinoma (HCC). We assessed the characteristics of patients with HCC treated with sorafenib who might be eligible for second-line treatment in general and regorafenib in particular. Methods Patients with HCC treated with sorafenib were retrospectively analyzed. We defined second-line candidate patients as maintaining Child-Pugh A and ECOG-PS ≤1 at the time of sorafenib failure. We also defined regorafenib candidate patients as follows: 1) continuing sorafenib at the time of radiological progression, 2) maintaining Child-Pugh A and ECOG-PS ≤ 1 at the time of sorafenib failure, and 3) continuing sorafenib 400 mg or more without intolerable adverse events at least 20 days of the last 28 days of treatment. Results Of 185 patients, 130 (70%) and 69 (37%) were candidates for second-line treatment and regorafenib. Child-Pugh score 6 and ECOG-PS 1 at the time of starting sorafenib were significantly lower in both second-line treatment and regorafenib candidate patients. Moreover, hand-foot skin reaction and liver failure during sorafenib treatment were associated with significantly low and high probabilities, respectively, of both Child-Pugh score > 6 and ECOG-PS > 1 at the time of sorafenib failure. Conclusion Regorafenib candidate patients after sorafenib failure are limited, and generally fewer than those who are candidates for second-line treatment. A lower Child-Pugh score and a better ECOG-PS were predictors of eligibility for second-line therapy and regorafenib treatment in sorafenib-treated patients with advanced HCC patients.

Clinical characteristics of Japanese patients with epithelioid hemangioendothelioma: a multicenter retrospective study.

BACKGROUND: Epithelioid hemangioendothelioma is an exceedingly rare sarcoma often occurring as an indolent angiocentric vascular tumor at various anatomic sites. Few reports have evaluated large case series of epithelioid hemangioendothelioma. METHODS: We conducted a retrospective analysis of the clinical data of 42 consecutive patients with epithelioid hemangioendothelioma who were pathologically diagnosed between 1990 and 2014 at 13 Japanese tertiary hospitals. We analyzed their clinical characteristics, tumor features and prognostic factors. RESULTS: The study included 22 men and 20 women, with a median age of 54 (range, 18-78) years. Pain was the most common symptom, occurring in 15 (68%) of the 22 symptomatic patients. The median maximum tumor diameter was 4.0 (range, 1.0-12.8) cm. The most commonly involved organs were the liver (81%), lungs (57%), and bones (12%). The overall survival rates were 79.5% at 1 year and 72.0% at 5 years. Substantially better survival was observed in asymptomatic patients than in symptomatic patients (P = 0.03), and better survival was also ovserved in patients with Ki-67 index ≤10% than in those with Ki-67 index > 10% (P = 0.04). By multivariate analysis, tumor size > 3.0 cm was associated with decreased survival (P = 0.049, hazard ratio 13.33). CONCLUSIONS: This study showed the clinical characteristics of Japanese patients with epithelioid hemangioendothelioma. Tumor size > 3.0 cm is an independent indicator of a poor prognosis in epithelioid hemangioendothelioma. The presence of symptoms at the time of diagnosis and high Ki-67 index implied poor survival.

A multicenter Phase II study of sorafenib in Japanese patients with advanced hepatocellular carcinoma and Child Pugh A and B class.

OBJECTIVE: To evaluate prospectively the efficacy and safety of sorafenib, which has been the first-line treatment for advanced hepatocellular carcinoma (HCC), in Japanese HCC patients (pts) with not only Child-Pugh (C-P) A class but also C-P B class. METHODS: Sorafenib was administered orally at the dose of 400 mg twice daily for pts with HCC and liver function of C-P score of 5-8. Administration was continued until the detection of disease progression or appearance of unacceptable toxicity. The primary endpoint was time to progression (TTP), and toxicity and the secondary endpoints included objective response, overall survival (OS). RESULTS: Forty C-P A pts and 12 C-P B pts were enrolled. The median TTP in the C-P A pts and C-P B pts was 3.3 months and 3.2 months, respectively. Among the pts with C-P A, complete response, partial response, and stable disease were achieved for 2.5%, 7.5% and 47.5%. Among the pts with C-P B, there were no treatment responses, 66.7% of pts had stable disease. The median OS in the C-P A pts and C-P B pts was 13.4 months and 7.4 months, respectively. With regard to toxicities, fewer C-P A pts experienced Grade 3/4 toxicities than C-P B pts (77.5% vs. 91.6%). There were no treatment-related deaths in either group of patients. CONCLUSIONS: This study shows sorafenib has similar effectiveness in the recent post-approval studies and is well-tolerated in Japanese pts with HCC and Child Pugh A class. Sorafenib should be used with great care for Child Pugh class B pts.

Protein 19F-labeling using transglutaminase for the NMR study of intermolecular interactions.

The preparation of stable isotope-labeled proteins is important for NMR studies, however, it is often hampered in the case of eukaryotic proteins which are not readily expressed in Escherichia coli. Such proteins are often conveniently investigated following post-expression chemical isotope tagging. Enzymatic 15N-labeling of glutamine side chains using transglutaminase (TGase) has been applied to several proteins for NMR studies. 19F-labeling is useful for interaction studies due to its high NMR sensitivity and susceptibility. Here, 19F-labeling of glutamine side chains using TGase and 2,2,2-trifluoroethylamine hydrochloride was established for use in an NMR study. This enzymatic 19F-labeling readily provided NMR detection of protein-drug and protein-protein interactions with complexes of about 100 kDa since the surface residues provided a good substrate for TGase. The 19F-labeling method was 3.5-fold more sensitive than 15N-labeling, and could be combined with other chemical modification techniques such as lysine 13C-methylation. 13C-dimethylated-19F-labeled FKBP12 provided more accurate information concerning the FK506 binding site.

Presence of non-hypervascular hypointense nodules on Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in patients with hepatocellular carcinoma.

BACKGROUND AND AIMS: Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) performed before curative therapy for hepatocellular carcinoma (HCC) can distinguish between intrahepatic distant recurrence and hypervascularization. This study aimed to retrospectively evaluate the presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI as a risk factor of the intrahepatic distant recurrence of early stage HCC following radiofrequency ablation (RFA). METHODS: A total of 132 patients who underwent preprocedural Gd-EOB-DTPA-enhanced MRI followed by initial RFA were retrospectively analyzed. Post-RFA intrahepatic distant recurrence, which excluded the hypervascularization of non-hypervascular hypointense nodules detected by preprocedural Gd-EOB-DTPA-enhanced MRI, was evaluated according to the presence of non-hypervascular hypointense nodules on preprocedural Gd-EOB-DTPA-enhanced MRI. RESULTS: Intrahepatic distant recurrence rates following RFA were higher in patients with non-hypervascular hypointense nodules (1-year: 22.5%, 2-year: 52.1%, 5-year: 89.1%) compared with in patients without non-hypervascular hypointense nodules (1-year: 7.0%, 2-year: 28.8%, 5-year: 48.7%). The presence of non-hypervascular hypointense nodules was associated with markedly increased cumulative recurrence rates of both identical and different subsegment intrahepatic distant recurrence, being an independent risk factor for post-RFA identical and different subsegment intrahepatic distant recurrence (identical: HR = 2.365, P = 0.027; different: HR = 3.276, P < 0.001). CONCLUSION: The presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI obtained prior to RFA is an important predictive factor of intrahepatic distant recurrence following RFA of HCC.

Real-World Experiences with the Combination Treatment of Ledipasvir plus Sofosbuvir for 12 Weeks in HCV Genotype 1-Infected Japanese Patients: Achievement of a Sustained Virological Response in Previous Users of Peginterferon plus Ribavirin with HCV NS3/4A Inhibitors.

The aim of this study was to characterize the treatment response and serious adverse events of ledipasvir plus sofosbuvir therapies in Japanese patients infected with hepatitis C virus (HCV) genotype 1 (GT1). This retrospective study analyzed 240 Japanese HCV GT1 patients treated for 12 weeks with 90 mg of ledipasvir plus 400 mg of sofosbuvir daily. Sustained virological response at 12 weeks post-treatment (SVR12) was achieved in 236 of 240 (98.3%) patients. Among treatment-naïve patients, SVR12 was achieved in 136 of 138 (98.6%) patients, and among treatment-experienced patients, SVR12 was achieved in 100 of 102 (98.0%) patients. In patients previously treated with peginterferon plus ribavirin with various HCV NS3/4A inhibitors, 100% SVR rates (25/25) were achieved. Two relapsers had HCV NS5A resistance-associated variants (RAVs), but no HCV NS5B-S282 was observed after they relapsed. We experienced two patients with cardiac events during treatment. In conclusion, combination of ledipasvir plus sofosbuvir for 12 weeks is a potential therapy for HCV GT1 patients. Caution is needed for HCV NS5A RAVs, which were selected by HCV NS5A inhibitors and cardiac adverse events.

Post-progression survival in patients with advanced hepatocellular carcinoma resistant to sorafenib.

BACKGROUND: Since the approval of sorafenib, no other agent has been proven to show survival benefits in clinical trials involving patients with advanced hepatocellular carcinoma (HCC) resistant to sorafenib. Prognostic factors for survival after tumor progression in sorafenib-treated patients are critical for designing second-line trials. METHODS: To determine the factors affecting the post-progression survival (PPS) after sorafenib treatment, additional analyses were conducted using fixed data obtained from our previous prospective study. Data on patients with advanced HCC treated with sorafenib were analyzed in view of patient characteristics at the time of tumor progression and the progression pattern (intra-/extrahepatic growth or emergence of new intra-/extrahepatic lesions). RESULTS: Of the 89 enrolled patients, 70 were diagnosed with disease progression according to the Response Evaluation Criteria in Solid Tumors version 1.1. Multivariate Cox's regression analysis revealed that Child-Pugh scores of ≥7, macrovascular invasion (MVI), and alpha-fetoprotein of >400 ng/mL were independent predictors of poor PPS. Although both extrahepatic metastasis (EHM) and MVI were characteristics of advanced HCC, EHM was not determined as a prognostic factor. Additionally, the emergence of new extrahepatic lesions also served as an independent indicator of a poor prognosis. The PPS of the patients was well stratified according to the index based on the sum of these prognostic factors, ranging from 0 to 4. CONCLUSIONS: Child-Pugh score of ≥7, AFP of >400 ng/mL, MVI, and new extrahepatic lesions at the time of progression may be utilized to assess the prognosis and taken into consideration when designing second-line trials.