Hepatic ketogenesis regulates lipid homeostasis via ACSL1-mediated fatty acid partitioning

Liver-derived ketone bodies play a crucial role in fasting energy homeostasis by fueling the brain and peripheral tissues. Ketogenesis also acts as a conduit to remove excess acetyl-CoA generated from fatty acid oxidation and protects against diet-induced hepatic steatosis. Surprisingly, no study has examined the role of ketogenesis in fasting-associated hepatocellular lipid metabolism. Ketogenesis is driven by the rate-limiting mitochondrial enzyme 3-hydroxymethylglutaryl CoA synthase (HMGCS2) abundantly expressed in the liver. Here, we show that ketogenic insufficiency via disruption of hepatic HMGCS2 exacerbates liver steatosis in fasted chow and high-fat-fed mice. We found that the hepatic steatosis is driven by increased fatty acid partitioning to the endoplasmic reticulum (ER) for re-esterification via acyl-CoA synthetase long-chain family member 1 (ACSL1). Mechanistically, acetyl-CoA accumulation from impaired hepatic ketogenesis is responsible for the elevated translocation of ACSL1 to the ER. Moreover, we show increased ER-localized ACSL1 and re-esterification of lipids in human NASH displaying impaired hepatic ketogenesis. Finally, we show that L-carnitine, which buffers excess acetyl-CoA, decreases the ER-associated ACSL1 and alleviates hepatic steatosis. Thus, ketogenesis via controlling hepatocellular acetyl-CoA homeostasis regulates lipid partitioning and protects against hepatic steatosis.

[Deep learning-based dose prediction in radiotherapy planning for head and neck cancer]

OBJECTIVE

To propose an deep learning-based algorithm for automatic prediction of dose distribution in radiotherapy planning for head and neck cancer.

METHODS

We propose a novel beam dose decomposition learning (BDDL) method designed on a cascade network. The delivery matter of beam through the planning target volume (PTV) was fitted with the pre-defined beam angles, which served as an input to the convolution neural network (CNN). The output of the network was decomposed into multiple sub-fractions of dose distribution along the beam directions to carry out a complex task by performing multiple simpler sub-tasks, thus allowing the model more focused on extracting the local features. The subfractions of dose distribution map were merged into a distribution map using the proposed multi-voting mechanism. We also introduced dose distribution features of the regions-of-interest (ROIs) and boundary map as the loss function during the training phase to serve as constraining factors of the network when extracting features of the ROIs and areas of dose boundary. Public datasets of radiotherapy planning for head and neck cancer were used for obtaining the accuracy of dose distribution of the BDDL method and for implementing the ablation study of the proposed method.

RESULTS

The BDDL method achieved a Dose score of 2.166 and a DVH score of 1.178 (P < 0.05), demonstrating its superior prediction accuracy to that of current state-ofthe-art (SOTA) methods. Compared with the C3D method, which was in the first place in OpenKBP-2020 Challenge, the BDDL method improved the Dose score and DVH score by 26.3% and 30%, respectively. The results of the ablation study also demonstrated the effectiveness of each key component of the BDDL method.

CONCLUSION

The BDDL method utilizes the prior knowledge of the delivery matter of beam and dose distribution in the ROIs to establish a dose prediction model. Compared with the existing methods, the proposed method is interpretable and reliable and can be potentially applied in clinical radiotherapy.

The Isolation of Flowing Mesenteric Lymph in Mice to Quantify In Vivo Kinetics of Dietary Lipid Absorption and Chylomicron Secretion

Intestinal lipoproteins, especially triglyceride-rich chylomicrons, are a major driver of metabolism, inflammation, and cardiovascular diseases. However, isolating intestinal lipoproteins is very difficult in vivo because they are first secreted from the small intestine into the mesenteric lymphatics. Chylomicron-containing lymph then empties into the subclavian vein from the thoracic duct to deliver components of the meal to the heart, lungs, and, ultimately, whole-body circulation. Isolating naïve chylomicrons is impossible from blood since chylomicron triglyceride undergoes hydrolysis immediately upon interaction with lipoprotein lipase and other lipoprotein receptors in circulation. Therefore, the original 2-day lymph fistula procedure, described by Bollman et al. in rats, has historically been used to isolate fresh mesenteric lymph before its entry into the thoracic vein. That protocol has been improved upon and professionalized by the laboratory of Patrick Tso for the last 45 years, allowing for the analysis of these critical lipoproteins and secretions from the gut. The Tso lymph fistula procedure has now been updated and is presented here visually for the first time. This revised procedure is a single-day surgical technique for installing a duodenal feeding tube, cannulating the mesenteric lymph duct, and collecting lymph after a meal in conscious mice. The major benefits of these new techniques include the ability to reproducibly collect lymph from mice (which harnesses the power of genetic mouse models); the reduced anesthesia time for mice during the implantation of the duodenal infusion tube and the lymph cannula; the ability to continuously sample lymph throughout the feeding and post-prandial period; the ability to quantitatively measure hormones and cytokines before their dilution and enzymatic hydrolysis in blood; and the ability to collect large quantities of lymph for isolating intestinal lipoproteins. This technique is a powerful tool for directly and quantitatively measuring dietary nutrient absorption, intestinal lipoprotein synthesis, and chylomicron secretion.

A single-day mouse mesenteric lymph surgery in mice: an updated approach to study dietary lipid absorption, chylomicron secretion, and lymphocyte dynamics

The intestine plays a crucial role in regulating whole-body lipid metabolism through its unique function of absorbing dietary fat. In the small intestine, absorptive epithelial cells emulsify hydrophobic dietary triglycerides (TAGs) prior to secreting them into mesenteric lymphatic vessels as chylomicrons. Except for short- and medium-chain fatty acids, which are directly absorbed from the intestinal lumen into portal vasculature, the only way for an animal to absorb dietary TAG is through the chylomicron/mesenteric lymphatic pathway. Isolating intestinal lipoproteins, including chylomicrons, is extremely difficult in vivo because of the dilution of postprandial lymph in the peripheral blood. In addition, once postprandial lymph enters the circulation, chylomicron TAGs are rapidly hydrolyzed. To enhance isolation of large quantities of pure postprandial chylomicrons, we have modified the Tso group's highly reproducible gold-standard double-cannulation technique in rats to enable single-day surgery and lymph collection in mice. Our technique has a significantly higher survival rate than the traditional 2-day surgical model and allows for the collection of greater than 400 μl of chylous lymph with high postprandial TAG concentrations. Using this approach, we show that after an intraduodenal lipid bolus, the mesenteric lymph contains naïve CD4+ T-cell populations that can be quantified by flow cytometry. In conclusion, this experimental approach represents a quantitative tool for determining dietary lipid absorption, intestinal lipoprotein dynamics, and mesenteric immunity. Our model may also be a powerful tool for studies of antigens, the microbiome, pharmacokinetics, and dietary compound absorption.

[The impact of the dosage of intraoperative opioids on postoperative survival outcomes in patients with pancreatic cancer]

Objective: To investigate the impact of the dosage of intraoperative opioids on postoperative survival of pancreatic cancer patients who underwent pancreatectomy. Methods: The clinical data of 95 patients with pancreatic cancer who underwent pancreatectomy at Harbin Medical University Cancer Hospital from September 2013 to August 2018 were retrospectively collected. Dosage of intraoperative opioid medications was converted to fentanyl equivalent dose. Patients were divided into high-dose group (fentanyl consumption ≥2.21 mg, n=46) and low-dose group (fentanyl consumption<2.21 mg, n=49) according to the median intra-operative fentanyl equivalents. The relapse-free survival (RFS) and overall survival (OS) between the two groups were compared. Cox proportional hazards regression model was used to analyze the impact of important covariates on RFS and OS. Results: RFS of patients in low-dose group at 1, 3 and 5 years was 75.5%, 26.5% and 15.2% respectively. OS of patients in low-dose group at 1, 3 and 5 years was 77.6%, 32.5% and 24.4% respectively. RFS of patients in high-dose group at 1, 3 and 5 years was 76.1%, 23.9% and 12.0% respectively. OS of patients in high-dose group at 1, 3 and 5 years was 76.1%, 37.0% and 15.0%. There was no significant difference in RFS and OS between the two groups (all P>0.05). Multivariate Cox analysis showed that dosage of intraoperative fentanyl was not associated with RFS (HR=1.205, 95%CI: 0.737-1.970, P=0.456) or OS (HR=1.062, 95%CI: 0.634-1.778, P=0.818). Conclusion: Dosage of intraoperative opioid has no effect on RFS and OS in pancreatic cancer patients undergoing pancreatectomy.

Site-specific therapy in cancers of unknown primary site: a systematic review and meta-analysis

Background

Cancer of unknown primary site (CUP) is a term applied to characterize pathologically confirmed metastatic cancer with unknown primary tumor origin. It remains uncertain whether patients with CUP benefit from site-specific therapy guided by molecular profiling.

Patients and methods

A systematic search in PubMed, Web of Science, Embase, Cochrane Library, and ClinicalTrials.gov, and of conference abstracts from January 1976 to January 2021 was performed to identify studies investigating the efficacy of site-specific therapy on patients with CUP. The quality of included studies was evaluated using the Cochrane risk of bias tool and Newcastle–Ottawa scale. Eligible studies were weighted and pooled for meta-analysis. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were assessed to compare the efficacy of site-specific therapy with empiric therapy in patients with CUP. In addition, subgroup analyses were conducted.

Results

Five studies comprising 1114 patients were identified, of which 454 patients received site-specific therapy, and 660 patients received empiric therapy. Our meta-analysis revealed that site-specific therapy was not significantly associated with improved PFS [HR 0.93, 95% confidence interval (CI) 0.74-1.17, P = 0.534] and OS (HR 0.75, 95% CI 0.55-1.03, P = 0.069), compared with empiric therapy. However, during subgroup analysis significantly improved OS was associated with site-specific therapy in the high-accuracy predictive assay subgroup (HR 0.46, 95% CI 0.26-0.81, P = 0.008) compared with the low accuracy predictive assay subgroup (HR 0.93, 95% CI 0.75-1.15, P = 0.509). Furthermore, compared with patients with less responsive tumor types, more survival benefit from site-specific therapy was found in patients with more responsive tumors (HR 0.67, 95% CI 0.46-0.97, P = 0.037).

Conclusions

Our results suggest that site-specific therapy is not significantly associated with improved survival outcomes; however, it might benefit patients with CUP with responsive tumor types.

•

Studies evaluating the role of site-specific therapy guided by molecular profiling in CUP provided contradictory results.

•

Site-specific therapy is not significantly associated with improved survival outcomes in the overall CUP population.

•

Molecularly defined site-specific therapy may improve OS only when high-accuracy assays assign CUP to responsive tumor types.

AB0552 PROBABILITY OF ACHIEVING TREATMENT TARGETS WITH APREMILAST MONOTHERAPY IN BIOLOGIC-NAIVE PSORIATIC ARTHRITIS PATIENTS IN ACTIVE WITH MODERATE AND HIGH BASELINE DISEASE ACTIVITY

Background:

Patients with psoriatic arthritis (PsA) in moderate disease activity (ModDA) who are naive to disease-modifying antirheumatic drugs (DMARDs) have a higher probability of achieving the Clinical Disease Activity Index for PsA (cDAPSA) treatment targets after receiving apremilast 30 mg BID (APR) than those in high disease activity (HDA). In Europe, APR is indicated for the treatment of active PsA in adult patients who had an inadequate response or were intolerant to a prior DMARD therapy. Achievement of cDAPSA treatment targets with APR monotherapy in biologic-naive patients with PsA who had previously taken a maximum of 1 conventional synthetic DMARD (csDMARD) has not been evaluated.

Objectives:

To assess the predictive value of baseline clinical disease status on achieving long-term cDAPSA treatment targets at Week 52 among biologic-naive patients with PsA in the phase 3b, randomized, placebo-controlled Assessing Apremilast Monotherapy in a Clinical Trial of Biologic-Naive Patients With PsA (ACTIVE).

Methods:

ACTIVE enrolled adults with PsA who had ≥3 swollen and ≥3 tender joints and were biologic naive with prior failure of a maximum of 1 csDMARD. In this post hoc analysis, we assessed the probabilities of achieving cDAPSA treatment targets of remission (REM; ≤4) or low disease activity (LDA; >4 to ≤13) at Week 52 in patients randomized to APR and stratified by cDAPSA ModDA (>13 to ≤27) or HDA (>27) at baseline. Patients with enthesitis at baseline in each stratum were analyzed separately.

Results:

Of the 109 patients randomized to APR, 35 were in ModDA (32.1%) and 71 were in HDA (65.1%) at baseline (Table 1). For patients with ModDA vs HDA at baseline, swollen (4.6 vs 10.8) and tender (6.7 vs 21.7) joint counts were lower, and the prevalence of enthesitis was lower (42.9% vs 57.7%) (Table 1). Patients in ModDA at baseline were estimated to be more than twice as likely to achieve treatment targets at Week 52 vs patients in HDA at baseline (Figure 1). Consistent with these results, a higher proportion of patients with ModDA + enthesitis at baseline achieved treatment targets at Week 52 than patients with HDA + enthesitis at baseline (58.9% vs 32.8%).

Table 1.

Baseline Demographics and Disease Characteristics

Baseline cDAPSA CategoryModDA (n = 35)HDA (n = 71)Age, mean (SD), years48.5 (12.9)51.6 (11.8)Women, n (%)20 (57.1)36 (50.7)White, n (%)34 (97.1)71 (100.0)PsA duration, mean (SD), years4.5 (4.6)3.8 (4.5)Enthesitis, n (%)15 (42.9)41 (57.7)SJC (0-66), mean (SD)4.6 (1.6)10.8 (4.3)TJC (0-68), mean (SD)6.7 (2.2)21.7 (11.5)PtGA (0-10 NRS), mean (SD)4.9 (1.4)6.5 (2.0)PhGA (0-10 NRS), mean (SD)5.4 (1.2)6.6 (1.5)

The n represents the total sample. The number of patients with data available may vary. Not included are 3 patients in LDA at baseline. NRS = Numeric Rating Scale; PhGA = Physician’s Global Assessment of Disease Activity; PtGA = Patient’s Global Assessment of Disease Activity; SJC = swollen joint count; TJC = tender joint count.

Figure 1.

Conclusion:

Similar to observations in DMARD-naive patients with PsA, patients who were biologic naive but may have had experience with a maximum of 1 csDMARD, including those with enthesitis, and who were in ModDA at baseline had a higher probability of achieving treatment targets (cDAPSA REM or LDA) at Week 52 with continued APR treatment compared with those with HDA.

Acknowledgements:

This study was funded by Celgene. Additional analyses were funded by Amgen Inc. Writing support was funded by Amgen Inc. and provided by Kristin Carlin, RPh, MBA, of Peloton Advantage, LLC, an OPEN Health company.

Disclosure of Interests:

Peter Nash Consultant of: AbbVie, BMS, Celgene, Gilead/Galapagos, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, and Samsung, Grant/research support from: AbbVie, BMS, Celgene, Gilead/Galapagos, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, and Samsung, Sven Richter Employee of: Amgen Inc., Shauna Jardon Employee of: Amgen Inc., Lichen Teng Employee of: Amgen Inc., Jessica A. Walsh Consultant of: AbbVie, Amgen Inc., Janssen, Lilly, Merck, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen Inc., Janssen, Lilly, Merck, Novartis, Pfizer, and UCB.

[Effects of protein disulfide isomerase on hyperglycemia and hypoxia/reoxygenation injury in H9c2 cardiomyocytes]

Objective: To explore the effect of protein disulfide isomerase (PDI) in diabetic ischemic heart disease. Methods: We established an in vitro model of high glucose and hypoxia/reoxygenation in H9c2 rat myocardial cells. Cultured cells were divided into four groups: Control, high glucose (HG), hypoxia/reoxygenation (H/R) and HG+H/R. Changes in PDI expression mediated by PDI adenovirus(Ad-PDI) infection and siRNA(PDI-siRNA) transfection in myocardial cells were observed by inverted fluorescence microscopy. We also measured lactate dehydrogenase(LDH) activity and malondialdehyde(MDA) and high molecular weight(HMW)-APN concentrations. PDI, APN, cleaved caspase-3, and glucose regulated protein 78 (Grp78) protein expression were detected. Results: PDI expression was significantly decreased in the HG, H/R and HG+H/R groups compared to the Control group; however, LDH activity[(179.7±10.4) U/L、(218.4±18.4) U/L、(328.2±5.3) U/L vs (91.0±11.0) U/L], MDA concentration[(7.0±0.4) μmol/L、(10.0±1.0) μmol/L、(11.7±1.0) μmol/L vs (4.2±1.8) μmol/L], cleaved caspase-3, and Grp78 expression were increased. Interestingly, APN and HMW-APN expression were decreased [(2.01±0.21) μg/L、(1.64±0.27) μg/L、(1.20±0.14) μg/L vs (2.62±0.12) μg/L, all P<0.05]. Over expression of PDI attenuated high glucose and hypoxia/reoxygenation induced apoptosis and oxidative stress in H9c2 cardiomyocytes(all P<0.05), and simultaneously increased APN and HMW-APN expression [(2.86±0.03) μg/L vs (3.03±0.10) μg/L、(2.06±0.05) μg/L vs (2.31±0.06) μg/L、(1.83±0.07) μg/L vs (1.96±0.11) μg/L、(1.20±0.06) μg/L vs (1.39±0.09) μg/L]. PDI-siRNA transfection increased LDH activity, MDA concentration, and cleaved caspase-3 and Grp78 expression, and decreased APN and HMW-APN expression [(0.75±0.09) μg/L vs (0.59±0.09) μg/L、(0.62±0.04) μg/L vs (0.53±0.05) μg/L、(0.55±0.14) μg/L vs (0.51±0.12) μg/L、(0.48±0.12) μg/L vs (0.35±0.08) μg/L] in response to different treatments in cultured H9c2 cardiomyocytes (all P<0.05). Conclusion: PDI may regulate the expression of APN and HMW-APN, and play an important role in the function of diabetic ischemia-reperfusion cardiomyocytes.

AB0553 BASELINE DISEASE ACTIVITY AS A PREDICTOR FOR ACHIEVING cDAPSA TREATMENT TARGETS WITH APREMILAST IN DMARD-NAIVE PATIENTS WITH MANIFESTATIONS OF ACTIVE PSORIATIC ARTHRITIS

Background:

In PALACE 4, DMARD-naive patients (pts) with moderately active (ModDA) psoriatic arthritis (PsA) at baseline (BL) were more likely to achieve Clinical Disease Activity Index for PsA (cDAPSA) treatment targets (cDAPSA remission [REM] or low disease activity [LDA]) at Week 52 with continued apremilast 30 mg BID (APR) treatment than pts with high disease activity (HDA) at BL. Pts who achieved cDAPSA treatment targets also had no or mild articular and extra-articular disease activity by Week 52. Whether specific PsA manifestations other than arthritis impact the achievement of cDAPSA treatment targets in this population is unknown.

Objectives:

To assess the predictive value of BL clinical disease status on achieving cDAPSA treatment targets in DMARD-naive pts in PALACE 4 with PsA in ModDA or HDA who exhibited manifestations of skin involvement, enthesitis, and/or dactylitis at BL.

Methods:

This post hoc analysis included APR-treated pts in ModDA or HDA with available cDAPSA data at BL and Week 52 who exhibited any of the PsA manifestations at BL, including skin-involved body surface area (BSA) ≥3%, Maastricht Ankylosing Spondylitis Entheses Score (MASES) >0, or dactylitis count >0. Pts were divided into 4 subgroups based on number of manifestations: ≥1, only 1, any 2, or all 3. The proportions of pts who shifted across ModDA (>13 to ≤27) and HDA (>27) cDAPSA categories at BL to REM (≤4) and LDA (>4 to ≤13) treatment targets at Week 52 were calculated (data as observed).

Results:

In 176 PALACE 4 pts with PsA receiving APR, 165 had involvement in ≥1 PsA manifestation in addition to peripheral arthritis (ie, skin/enthesitis/dactylitis) at BL. This population had a mean age of 48.8 years, PsA duration of 3.6 years, Psoriasis Area and Severity Index (PASI) score of 6.6, MASES of 3.8, and dactylitis count of 3.5 (Table 1). Within this subgroup, 32.7% had only 1 of these non-arthritic PsA manifestations, 50.9% had any 2, and 16.4% had all 3. In pts with ≥1 manifestation, a greater proportion in ModDA achieved REM/LDA at Week 52 than those in HDA (66.7% vs 32.2%; risk difference: 0.34) (Figure 1). Similarly, greater rates of treatment target achievement were observed in subgroups of pts in ModDA vs HDA and only 1 (72.2% vs 39.1%; risk difference: 0.33), any 2 (57.1% vs 28.6%; risk difference: 0.29), or all 3 (75.0% vs 33.3%; risk difference: 0.42) PsA manifestations (Figure 1).

Conclusion:

In DMARD-naive pts exhibiting various non-arthritic manifestations of active PsA (ie, skin/enthesitis/dactylitis), those in ModDA at BL were more likely to achieve cDAPSA REM or LDA at Week 52 of APR treatment than pts in HDA. This observation was consistent whether pts had only 1 or multiple manifestations. These findings are consistent with the probability of achieving treatment targets demonstrated in the overall population in PALACE 4 (61.7% ModDA vs 28.2% HDA).

Table 1.

BL Demographics and Disease Characteristics in Pts With ≥1 Manifestations of PsA (Skin Involvement, Enthesitis, and/or Dactylitis) Treated With APR (N = 165)

Age*, years48.8 (12.5)Women, n (%)87 (52.7)BMI*, kg/m229.9 (6.5)Duration of PsA*, years3.6 (5.0)Duration of psoriasis*, years15.5 (13.3)cDAPSA (0-154)*39.4 (19.7)Swollen joint count (0-66)*10.3 (7.7)Tender joint count (0-68)*18.5 (12.9)Pt’s Assessment of Pain (VAS 0-100 mm)*52.8 (21.5)Pt’s Global Assessment (VAS 0-100 mm)*53.8 (20.1)Physician’s Global Assessment (VAS 0-100 mm)*52.2 (17.6)PASI score (0-72)*,†6.6 (5.1)MASES (0-13)*,‡3.8 (3.0)Dactylitis count (0-20)*,§3.5 (3.3)Corticosteroid use, n (%)13 (7.9)NSAID use, n (%)126 (76.4)

*Mean (SD).†In pts with BSA ≥3% at BL.‡In pts with enthesitis at BL.§In pts with dactylitis at BL.

Acknowledgements:

This study was funded by Celgene. Additional analyses were funded by Amgen Inc. Writing support was funded by Amgen Inc. and provided by Kristin Carlin, RPh, MBA, of Peloton Advantage, LLC, an OPEN Health company.

Figure 1.

Disclosure of Interests:

Philip J Mease Speakers bureau: AbbVie, Amgen Inc., Eli Lilly, Janssen, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen Inc., Boehringer Ingelheim, BMS, Celgene, Eli Lilly, Galapagos, GSK, Novartis, Pfizer, Sun, and UCB, Grant/research support from: AbbVie, Amgen Inc., Boehringer Ingelheim, BMS, Celgene, Eli Lilly, Galapagos, GSK, Novartis, Pfizer, Sun, and UCB, Arthur Kavanaugh Grant/research support from: AbbVie, Amgen Inc., AstraZeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, and UCB, Alexis Ogdie Consultant of: AbbVie, Amgen Inc., BMS, Celgene, Corrona, Eli Lilly, Gilead, Novartis, Pfizer, and UCB, Grant/research support from: Novartis and Pfizer, Alvin F. Wells Speakers bureau: AbbVie, Alexion, Amgen Inc., BMS, Celgene, Horizon, Lilly, Novartis, and UCB, Consultant of: AbbVie, Alexion, Amgen Inc., BMS, Celgene, Horizon, Lilly, Novartis, and UCB, Grant/research support from: AbbVie, Celgene, and Lilly, Martin Bergman Shareholder of: Johnson & Johnson, Speakers bureau: AbbVie, Amgen Inc., Novartis, Pfizer, and Sanofi, Consultant of: AbbVie, BMS, Celgene, Genentech, Janssen, Merck, Novartis, Pfizer, and Sanofi, Dafna D Gladman Consultant of: AbbVie, Amgen, BMS, Celgene Corporation, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, BMS, Celgene Corporation, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, and UCB, Frank Behrens Speakers bureau: AbbVie, Biotest, Boehringer Ingelheim, Celgene, Chugai, Eli Lilly, Genzyme, Janssen, Novartis, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, Chugai, Janssen, Roche, and Pfizer, Yuri Klyachkin Employee of: Amgen Inc., Sven Richter Employee of: Amgen Inc., Lichen Teng Employee of: Amgen Inc., Josef S. Smolen Speakers bureau: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, MSD, Novartis, Pfizer, Roche, Samsung, Sanofi, and UCB, Consultant of: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, MSD, Novartis, Pfizer, Roche, Samsung, Sanofi, and UCB, Grant/research support from: AbbVie, Eli Lilly, Janssen, MSD, Medimmune, Pfizer, and Roche.

FRI0352 PROBABILITY OF ACHIEVING LOW DISEASE ACTIVITY OR REMISSION WITH APREMILAST TREATMENT AMONG DMARD-NAIVE SUBJECTS WITH ACTIVE PSORIATIC ARTHRITIS

Background:

Apremilast (APR) is associated with comparable ACR response rates in DMARD-naive vs DMARD-experienced patients (pts) with psoriatic arthritis (PsA).1,2A question that remains is if DMARD-naive pts treated with APR have greater chances of achieving treatment targets than DMARD-experienced pts. cDAPSA is a commonly used treatment target.

Objectives:

To assess the predictive value of baseline (BL) clinical disease status on achieving long-term cDAPSA treatment targets at Wk 52 among DMARD-naive subjects in PALACE 4; to compare these findings vs those recently reported from the PALACE 1-3 studies in subjects with prior exposure to DMARDs; and to provide further evidence that at a group level, achievement of cDAPSA disease targets with APR is associated with no or mild articular and extra-articular disease activity by Wk 52.

Methods:

This post hoc analysis included subjects assigned to APR 30 mg twice daily at BL who had available cDAPSA data at BL. We calculated the probabilities of shifting across different cDAPSA categories (remission [REM]: ≤4; low disease activity [LDA]: >4 to ≤13; moderate disease activity [Mod]: >13 to ≤27; high disease activity [HDA]: >273) from BL to Wk 52. Mean values of articular and non-articular variables (e.g., PASI, SJC/TJC, MASES, dactylitis) from BL to Wk 52 were assessed by cDAPSA category achieved at Wk 52 to determine the association between achievement of targets and control of articular and non-articular manifestations. Results from the current analyses were compared with the previously reported results from PALACE 1-3.

Results:

A total of 175 subjects receiving APR were included; at BL, 66.3% were in HDA, 31.4% in Mod, and 2.3% were in LDA. Overall, subjects who achieved treatment targets (LDA or REM) by Wk 52 had lower levels of disease activity at BL, as shown by a lower number of swollen and tender joints and lower presence of enthesitis and dactylitis. Higher prevalence of psoriasis-involved body surface area ≥3% at BL was observed. Subjects in Mod at BL were estimated to be more than twice as likely to achieve REM or LDA at Wk 52 vs subjects in HDA at BL; for subjects in LDA at BL, the estimated probability of achieving cDAPSA treatment targets was 100% (Figure). PALACE 4 subjects with LDA and Mod at BL exhibited higher estimated probabilities of achieving treatment targets (100.0% and 61.7%, respectively) than those observed in the DMARD-experienced population of PALACE 1-3 (71.1% and 46.9%). Subjects in PALACE 4 who achieved REM or LDA by Wk 52 showed no or mild articular and extra-articular disease activity by Wk 52, similar to what was observed in the PALACE 1-3 population.4

Conclusion:

DMARD-naive subjects in PALACE 4 who had LDA or Mod at BL had the highest likelihood of achieving treatment targets (cDAPSA REM or LDA) by Wk 52 with continued APR treatment. Results from the current probability analyses revealed higher probability rates than those observed in the DMARD-experienced PALACE 1-3 population; control of articular and extra-articular manifestations was observed in the DMARD-naive and DMARD-experienced populations.

References:

[1]Wells AF, et al. Rheumatology. 2018;57:1253-63. 2. Kavanaugh A, et al. Arthritis Res Ther. 2019;21:118. 3. Machado PM. Ann Rheum Dis. 2016;75:787-90. 4. Mease PJ, et al. Arthritis Care Res. 2020 Jan 7.

Disclosure of Interests:

Philip J Mease Grant/research support from: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – grant/research support, Consultant of: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – consultant, Speakers bureau: Abbott, Amgen, Biogen Idec, BMS, Eli Lilly, Genentech, Janssen, Pfizer, UCB – speakers bureau, Arthur Kavanaugh Grant/research support from: Abbott, Amgen, AstraZeneca, BMS, Celgene Corporation, Centocor-Janssen, Pfizer, Roche, UCB – grant/research support, Alexis Ogdie Grant/research support from: Novartis, Pfizer – grant/research support, Consultant of: AbbVie, BMS, Eli Lilly, Novartis, Pfizer, Takeda – consultant, Alvin F. Wells Grant/research support from: AbbVie, Celgene Corporation, Lilly – grant/research support, Consultant of: AbbVie, Alexion, Amgen, BMS, Celgene Corporation, Horizon, Lilly, Novartis, UCB – consultant, Speakers bureau: AbbVie, Alexion, Amgen, BMS, Celgene Corporation, Horizon, Lilly, Novartis, UCB – speakers bureau, Martin Bergman Shareholder of: Johnson & Johnson – stockholder, Consultant of: AbbVie, BMS, Celgene Corporation, Genentech, Janssen, Merck, Novartis, Pfizer, Sanofi – consultant, Speakers bureau: AbbVie, Celgene Corporation, Novartis, Pfizer, Sanofi – speakers bureau, Dafna D Gladman Grant/research support from: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – grant/research support, Consultant of: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – consultant, Frank Behrens Grant/research support from: AbbVie, Chugai, Janssen, Roche, Pfizer – grant/research support, Consultant of: AbbVie Biotest, Boehringer Ingelheim, Celgene Corporation, Chugai, Eli Lilly, Genzyme, Janssen, Novartis, Pfizer, Roche, UCB – consultant, Speakers bureau: AbbVie, Biotest, BMS, Celgene Corporation, Chugai, Eli Lilly, Genzyme, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Sandoz, UCB - speaker, Sven Richter Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Michele Brunori Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Lichen Teng Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Benoit Guerette Employee of: Amgen Inc. – employment; Celgene Corporation – employment at the time of study conduct, Josef S. Smolen Grant/research support from: AbbVie, Eli Lilly, Janssen, Merck Sharp & Dohme, Pfizer, Roche – grant/research support, Consultant of: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – consultant, Speakers bureau: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – speaker

Racial disparity of Crouzon syndrome in maxilla and mandible

The racial disparity of facial features in craniosynostosis patients is not fully understood. The aim of this study was to explore the difference in maxillary and mandibular morphology and spatial position in Asian and Caucasian Crouzon syndrome patients. Ninety-one computed tomography scans were included (12 Asian Crouzon syndrome patients, 22 Asian controls; 16 Caucasian Crouzon syndrome patients, 41 Caucasian controls) and measured using Materialise software. The maxillary and mandibular volumes of Asian patients were both reduced by 19% (P=0.102 and P=0.187), and those of Caucasian patients were reduced by 15% (P=0.142) and 14% (P=0.211) when compared to the respective race-specific controls. Maxilla length of Asian patients was reduced by 6.36mm (14%, P=0.003), while the reduction in Caucasian patients was 4.88mm (10%, P=0.038). ANS was retracted 11.99mm (P<0.001) in Asian patients and 11.54mm (P<0.001) in Caucasian patients. The ANB angle was narrowed by 13.17° (P<0.001) in Asian patients compared to Asian controls, and by 7.02° (P<0.001) in Caucasian patients compared to Caucasian controls. The retrusive midface profiles of Asian and Caucasian Crouzon syndrome look similar; both result from the combined effect of hypoplastic size and backward displacement. However, the insufficiency was found to be more a failure of the anteroposterior maxillary length in Asian patients, and more due to posterior maxillary positioning in Caucasian patients. Therefore, prognathism in Crouzon syndrome patients is more likely caused by displacement rather than elongation of mandibular length in both races. Crouzon syndrome results in the same extent of overall volume deficiency of the maxilla and mandible in these races.

[Study of neuron-protective effect and mechanism of neuregulin1β against cerebral ischemia reperfusion-induced injury in rats]

Objective: Thecurrent study is to explore the neuron-protective mechanism of neuregulin1β (NRG1β) in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) through inhibiting the c-Jun phosphorylation. Methods: After 24 h of MCAO/R (referring to Longa's method), neurobehavioral function was measured by modified neurological severity score (mNSS) test; the cerebral infarction volume was detected by triphenyltetrazolium chloride (TTC) staining; the blood brain barrier (BBB) permeability was measured by Evans Blue (EB); the neuron morphology of brain tissue was observed by Nissl stain; the ultra-structures of the neurons were observed by transmission electron microscopy (TEM); the apoptotic neurons were counted by in situ cell death detection kit colocalized with NeuN; the expressions of phospho-c-Jun was determined by immunofluorescent labeling and Western blot analysis. Results: Compared with the sham-operation rats, the rats receiving MCAO/R showed increased mNSS (9.7±1.2), cerebral infarction volume (41.4±3.0)%, permeability of BBB, deformation of neurons, ischemia-induced apoptosis (0.63±0.04), and enhanced expression of phospho-c-Jun protein (0.90±0.07) (all P<0.05). Our data indicated that NRG1β attenuated neurologic deficits (6.4±0.9), decreased the cerebral infarction volume (10.4±0.5), reduced EB extravasation (1.55±0.13) and the deformation of neurons, protected the ultra-structure of neurons, blocked ischemia-induced apoptosis (0.23±0.02), through down-regulated phospho-c-Jun expression (0.40±0.03) in MCAO/R rats (P<0.05). Conclusion: NRG1β exerts neuron-protective effects against ischemia reperfusion-induced injury in rats through inhibiting the c-Jun phosphorylation.

[Effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells]

OBJECTIVE

To investigate the effects and related mechanism of quercetin on thrombin-induced proliferation and migration of rat vascular smooth muscle cells(VSMCs).

METHODS

Third to fifth generation VSMCs were divided into three groups, including control group (with PBS on the base of medium DMEM), thrombin group (with 1 U/ml thrombin on the base of medium DMEM) and quercetin group (treated with 100 μmol/L quercetin before 1 U/ml thrombin on the base of medium DMEM). The proliferation and migration capacitities were tested by CCK-8 kit and transwell chamber, respectively. The protein level of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were measured by Western blot.

RESULTS

(1) According to the CCK-8 results, optical density value was significantly higher in thrombin group than that of control group(2.59±0.16 vs. 1.97±0.18, P<0.01), which could be significantly attenuated by pretreatment with quercetin(2.13±0.19, P<0.01), and there was no significant difference between quercetin group and control group(P>0.05). (2) The transwell results showed that the migrated VSMCs were significantly higher in thrombin group than in control group (1 337±162 vs. 99±26, P<0.01), which could be significantly reduced by pretreatment with quercetin (926±111, P<0.05), but still significantly higher than control group (P<0.01). (3) The protein expressions of phospho-extracellular signal regulated kinase 1/2 and phosphor-p38 were significantly upregulated in thrombin group compared to control group (both P<0.05), which could be significantly downregulated by pretreatment with quercetin (P<0.05).

CONCLUSION

Quercetin can effectively attenuate thrombin-induced vascular smooth muscle cells proliferation and migration, possibly through inhibiting the phosphorylation of extracellular signal regulated kinase 1/2 and p38 pathway.

Expression of bovine non-classical major histocompatibility complex class I proteins in mouse P815 and human K562 cells

Major histocompatibility complex class I (MHC-I) proteins can be expressed as cell surface or secreted proteins. To investigate whether bovine non-classical MHC-I proteins are expressed as cell surface or secreted proteins, and to assess the reactivity pattern of monoclonal antibodies with non-classical MHC-I isoforms, we expressed the MHC proteins in murine P815 and human K562 (MHC-I deficient) cells. Following antibiotic selection, stably transfected cell lines were stained with H1A or W6/32 antibodies to detect expression of the MHC-I proteins by flow cytometry. Two non-classical proteins (BoLA-NC1*00501 and BoLA-NC3*00101) were expressed on the cell surface in both cell lines. Surprisingly, the BoLA-NC4*00201 protein was expressed on the cell membrane of human K562 but not mouse P815 cells. Two non-classical proteins (BoLA-NC1*00401, which lacks a transmembrane domain, and BoLA-NC2*00102) did not exhibit cell surface expression. Nevertheless, Western blot analyses demonstrated expression of the MHC-I heavy chain in all transfected cell lines. Ammonium-sulfate precipitation of proteins from culture supernatants showed that BoLA-NC1*00401 was secreted and that all surface expressed proteins where shed from the cell membrane by the transfected cells. Interestingly, the surface expressed MHC-I proteins were present in culture supernatants at a much higher concentration than BoLA-NC1*00401. This comprehensive study shows that bovine non-classical MHC-I proteins BoLA-NC1*00501, BoLA-NC3*00101, and BoLA-NC4*00201 are expressed as surface isoforms with the latter reaching the cell membrane only in K562 cells. Furthermore, it demonstrated that BoLA-NC1*00401 is a secreted isoform and that significant quantities of membrane associated MHC-I proteins can be shed from the cell membrane.

Mutations that disrupt PHOXB interaction with the neuronal calcium sensor HPCAL1 impede cellular differentiation in neuroblastoma

Heterozygous germline mutations in PHOX2B, a transcriptional regulator of sympathetic neuronal differentiation, predispose to diseases of the sympathetic nervous system, including neuroblastoma and congenital central hypoventilation syndrome (CCHS). Although the PHOX2B variants in CCHS largely involve expansions of the second polyalanine repeat within the C-terminus of the protein, those associated with neuroblastic tumors are nearly always frameshift and truncation mutations. To test the hypothesis that the neuroblastoma-associated variants exert their effects through loss or gain of protein-protein interactions, we performed a large-scale yeast two-hybrid screen using both wild-type (WT) and six different mutant PHOX2B proteins against over 10 000 human genes. The neuronal calcium sensor protein HPCAL1 (VILIP-3) exhibited strong binding to WT PHOX2B and a CCHS-associated polyalanine expansion mutant but only weakly or not at all to neuroblastoma-associated frameshift and truncation variants. We demonstrate that both WT PHOX2B and the neuroblastoma-associated R100L missense and the CCHS-associated alanine expansion variants induce nuclear translocation of HPCAL1 in a Ca(2+)-independent manner, while the neuroblastoma-associated 676delG frameshift and K155X truncation mutants impair subcellular localization of HPCAL1, causing it to remain in the cytoplasm. HPCAL1 did not appreciably influence the ability of WT PHOX2B to transactivate the DBH promoter, nor did it alter the decreased transactivation potential of PHOX2B variants in 293T cells. Abrogation of the PHOX2B-HPCAL1 interaction by shRNA knockdown of HPCAL1 in neuroblastoma cells expressing PHOX2B led to impaired neurite outgrowth with transcriptional profiles indicative of inhibited sympathetic neuronal differentiation. Our results suggest that certain PHOX2B variants associated with neuroblastoma pathogenesis, because of their inability to bind to key interacting proteins such as HPCAL1, may predispose to this malignancy by impeding the differentiation of immature sympathetic neurons.

Low prevalence of human papillomavirus (HPV) in Chinese patients with breast cancer

This retrospective study investigated the presence of human papillomavirus (HPV) in Chinese women with breast cancer, and the correlation between HPV infection and carcinogenesis. Tumour and non-cancerous breast tissue samples were obtained from 62 female patients with breast cancer; normal breast tissue samples were obtained from 46 women without breast cancer. HPV DNA was detected by nested polymerase chain reaction using consensus primers; HPV subtypes were determined by reverse dot blot and pyrosequencing analyses. HPV was found in tumour tissue samples from four of the 62 patients (6.5%), while no HPV DNA was detected in either the non-cancerous samples from patients with breast cancer or from the normal breast tissue controls. Of the four HPV-positive cases, three were HPV 16 positive (75%) and one was HPV 18 positive (25%). The low frequency of HPV detected in this study suggests that this infection is not a major risk factor in breast cancer development.

FP3: a novel VEGF blocker with antiangiogenic effects in vitro and antitumour effects in vivo

BACKGROUND Vascular endothelial growth factor (VEGF) is a critical promoter of blood vessel growth during embryonic development and neovascularisation in tumours. VEGF serves as a logical target for antiangiogenic cancer therapy because of its fundamental role in tumour angiogenesis. This study is to investigate the inhibitory effects of FP3, a novel VEGF blocker, on angiogenesis in vitro and tumour growth in vivo. METHODS The inhibitory effects of FP3 on angiogenesis in vitro were evaluated by using human umbilical vein endothelial cells (HUVECs) and rat aortic ring. The inhibitory effects of FP3 on tumour growth and angiogenesis in vivo were evaluated in a human non-small-cell lung cancer (NSCLC) cell line A549 tumour xenograft model with the methods of tumour growth regression assay and immunohistochemical staining, respectively. RESULTS In experiments with HUVECs, FP3 inhibited cell proliferation and migration. In rat aortic ring assay, FP3 suppressed VEGF-induced vessel sprouting. In tumour growth regression assay, FP3 significantly blocked the growth of A549 tumour in the subcutaneous tumour xenograft model and dramatically decreased the vessel density of tumour. CONCLUSIONS FP3 has excellent inhibitory effects on tumour angiogenesis both in vitro and in vivo, therefore it could be used as an effective antiangiogenic agent.

Prevalence of human papillomavirus in Chinese patients with colorectal cancer

AIM

The prevalence of human papillomavirus (HPV) was determined in Chinese patients with colorectal cancer (CRC). The study also aimed to determine whether the HPV DNA peripheral blood (PB) assay can be used to diagnose HPV-related CRC.

METHOD

Tumour tissue, noncancerous colorectal tissue and whole-blood samples were obtained from 96 patients with CRC. In addition, 32 colorectal tissue samples were harvested from patients without CRC, and 48 whole-blood samples were collected from healthy blood donors. HPV DNA was detected by means of a nested polymerase chain reaction (PCR) using consensus primers, and HPV genotypes were determined by reverse Southern blot and pyrosequencing.

RESULTS

HPV DNA was detected in 32 of the 96 patients with CRC, and colorectal tissues from the 32 control patients without CRC were negative for HPV DNA (P < 0.001). Among 48 healthy donors, three had detectable levels of HPV DNA in their PB. Patients with CRC did not have significantly higher levels of HPV DNA than controls. The HPV prevalence in tumour tissues was higher than that in noncancerous colorectal tissues (P < 0.001) or that in PB samples (P < 0.001). No correlation between the presence of HPV and demographic or medical characteristics was observed. HPV 16 was the viral type most frequently detected and was found in 33 (94%) of 35 HPV-positive patients.

CONCLUSION

HPV infection may be a risk factor for CRC. However, detection of HPV DNA in PB does not appear to reflect the HPV status of CRC.

Silencing of ferrochelatase enhances 5-aminolevulinic acid-based fluorescence and photodynamic therapy efficacy

Background:

Recurrence of glioma frequently occurs within the marginal area of the surgical cavity due to invading residual cells. 5-Aminolevulinic acid (5-ALA) fluorescence-guided resection has been used as effective therapeutic modalities to improve discrimination of brain tumour margins and patient prognosis. However, the marginal areas of glioma usually show vague fluorescence, which makes tumour identification difficult, and the applicability of 5-ALA-based photodynamic therapy (PDT) is hampered by insufficient therapeutic efficacy in glioma tissues.

Methods:

To overcome these issues, we assessed the expression of ferrochelatase (FECH) gene, which encodes a key enzyme that catalyses the conversion of protoporphyrin IX (PpIX) to heme, in glioma surgical specimens and manipulated FECH in human glioma cell lines.

Results:

Prominent downregulation of FECH mRNA expression was found in glioblastoma tissues compared with normal brain tissues, suggesting that FECH is responsible for PpIX accumulation in glioblastoma cells. Depletion of FECH by small interference RNA enhanced PpIX fluorescence after exposure to 5-ALA concomitant with increased intracellular PpIX accumulation in glioma cells. Silencing of FECH caused marked growth inhibition and apoptosis induction by PDT in glioma cells.

Conclusion:

These results suggest that knockdown of FECH is a potential approach to enhance PpIX fluorescent quality for optimising the subjective discrimination of vague fluorescence and improving the effect of 5-ALA-PDT.

Effects of dietary fat and enterostatin on dopamine and 5-hydroxytrytamine release from rat striatal slices

Studies have demonstrated defects of DA and 5HT neurotransmission in dietary fat induced obese animals. In the present study, we used a perfusion system to assay the release of DA and 5HT from striatal slices preloaded with [(3)H]-DA or [(3)H]-5HT. The release of both DA and 5HT from striatal slices of rats fed a high fat diet for 10 days, but not 3 days, was reduced when compared to striatal slices taken from rats fed a low fat diet. Enterostatin, an endogenous pentapeptide inhibits dietary fat intake when administered peripherally and centrally in animals. The central mechanism for the action of enterostatin is not yet determined even though several mechanisms have been suggested. We have shown that enterostatin enhanced [(3)H]-DA release, but not [(3)H]-5HT release from striatal slices of rats that had been adapted to high fat diet for 10 days. The enterostatin-induced increase in [(3)H]-DA release was blocked by nomifensine. Enterostatin did not alter [(3)H]-DA or [(3)H]-5HT release from striatal slices of rats adapted to high fat or low fat diet feeding for 3 days. These findings suggest that enterostatin may inhibit dietary fat intake by blocking dopamine reuptake transport to increase central striatal DA release from rats that have acquired diminished dopamine signal after an adaptive period of fat consumption.

Epithelial transformation by KLF4 requires Notch1 but not canonical Notch1 signaling

The transcription factors Notch1 and KLF4 specify epithelial cell fates and confer stem cell properties. Suggesting a functional relationship, each gene can act to promote or suppress tumorigenesis in a context-dependent manner, and alteration of KLF4 or Notch pathway genes in mice gives rise to similar phenotypes. Activation of a conditional allele of KLF4 in RK3E epithelial cells rapidly induces expression of Notch1 mRNA and the active, intracellular form of Notch1. KLF4-induced transformation was suppressed by knockdown of endogenous Notch1 using siRNA or an inhibitor of gamma-secretase. Chromatin immunoprecipitation assay shows that KLF4 binds to the proximal Notch1 promoter in human mammary epithelial cells, and siRNA-mediated suppression of KLF4 in human mammary cancer cells results in reduced expression of Notch1. Furthermore, KLF4 and Notch1 expression are correlated in primary human breast tumors (N = 89; Pearson analysis, r > 0.5, p < 0.0001). Like KLF4, Notch1 was previously shown to induce transformation of rat cells immortalized with adenovirus E1A, similar to RK3E cells. We therefore compared the signaling requirements for Notch1- or KLF4-induced malignant transformation of RK3E. As expected, transformation by Notch1 was suppressed by dominant-negative CSL or MAML1, inhibitors of canonical Notch1 signaling. However, these inhibitors did not suppress transformation by KLF4. Therefore, while KLF4-induced transformation requires Notch1, canonical Notch1 signaling is not required, and Notch1 may signal through a distinct pathway in cells with increased KLF4 activity. These results suggest that KLF4 could contribute to breast tumor progression by activating synthesis of Notch1 and by promoting signaling through a non-canonical Notch1 pathway.

Identification of claudin-4 as a marker highly overexpressed in both primary and metastatic prostate cancer

In the quest for markers of expression and progression for prostate cancer (PCa), the majority of studies have focussed on molecular data exclusively from primary tumours. Although expression in metastases is inferred, a lack of correlation with secondary tumours potentially limits their applicability diagnostically and therapeutically. Molecular targets were identified by examining expression profiles of prostate cell lines using cDNA microarrays. Those genes identified were verified on PCa cell lines and tumour samples from both primary and secondary tumours using real-time RT–PCR, western blotting and immunohistochemistry. Claudin-4, coding for an integral membrane cell-junction protein, was the most significantly (P<0.00001) upregulated marker in both primary and metastatic tumour specimens compared with benign prostatic hyperplasia at both RNA and protein levels. In primary tumours, claudin-4 was more highly expressed in lower grade (Gleason 6) lesions than in higher grade (Gleason ⩾7) cancers. Expression was prominent throughout metastases from a variety of secondary sites in fresh-frozen and formalin-fixed specimens from both androgen-intact and androgen-suppressed patients. As a result of its prominent expression in both primary and secondary PCas, together with its established role as a receptor for Clostridium perfringens enterotoxin, claudin-4 may be useful as a potential marker and therapeutic target for PCa metastases.

Healthcare worker's perceptions of barriers to care by immigrant women with postpartum depression: an exploratory qualitative study

OBJECTIVE

We interviewed healthcare workers working in Toronto, Canada, regarding their experience of providing care to recent immigrant women suffering from postpartum depression. The objective was two-fold: 1) to identify potential barriers to care that recent immigrant women may encounter as perceived by healthcare workers; and 2) to identify challenges healthcare workers felt that they faced as providers of care to this population.

METHODS

Qualitative semi-structured interviews were conducted with 16 key informants from various disciplines employed by healthcare agencies providing care to postpartum immigrant women in Toronto. Constant comparative analysis was used to analyze the data.

RESULTS

Two main categories of barriers to care for recent immigrant women were identified: 'practical barriers' and 'culturally determined barriers'. Practical barriers included knowing where and how to access services, and language difficulties. Cultural barriers included fear of stigma and lack of validation of depressive symptoms by family and society. The challenges experienced by healthcare providers working with this population were organized into two other categories: 'professional limitations', and 'social/cultural barriers'. 'Professional limitations' included fear of incompetence, language barriers, and inadequate assessment tools. 'Social/cultural barriers' included the experience of cultural uncertainty.

CONCLUSIONS

The results suggest that not only are there important barriers to accessing postpartum care for recent immigrant women, but it can also be challenging for healthcare workers to deliver such needed care. Understanding some of these barriers and challenges from the perspective of healthcare providers is an important step to remedying gaps and obstacles in the service system.

The clinical value of hepatocyte growth factor and its receptor--c-met for liver cancer patients with hepatectomy

BACKGROUND

To study the dynamic change of hepatocyte growth factor after hepatectomy in patients with primary liver cancer, and to analyse the prognostic value of hepatocyte growth factor and c-met for these patients.

METHODS

Thirty-one consecutive patients undergoing partial hepatectomy for liver cancer were studied. Serum hepatocyte growth factor level was determined by using enzyme-linked immunosorbent assay kit before and after operation, respectively. C-met protein and MRNA expressions in cancerous and paracancerous tissues were examined by immunohistochemical and RT-PCR methods, respectively. The correlations between clinical-pathologic parameters and the expressions of hepatocyte growth factor in serum and c-met in cancerous tissues were analysed, respectively.

RESULTS

Liver cancer patients had a significantly higher level of serum hepatocyte growth factor than normal controls (1.0424+/-0.498 ng/ml versus 0.685+/-0.115 ng/ml, p=0.008). Serum hepatocyte growth factor level was positively affected by tumour size, node cirrhosis, portal vein tumour thrombi, cholangiocarcinoma (including combined hepatocellular carcinoma), poorly differentiated hepatocellular carcinoma and tumour recurrence or metastases. After hepatectomy, serum hepatocyte growth factor level peaked on the third postoperative day, and then declined, but did not return to normal level on the postoperative day 10. From the preoperative day to postoperative day 10, the level of serum hepatocyte growth factor had a decrease of percent (85.33+/-10.2%) in the group with large tumours (>5 cm), but an elevation of percent (121.9+/-10.3%) in the group with small tumours (<or=5 cm). From the preoperative day to postoperative day 3, the level of serum hepatocyte growth factor had a higher elevation in the group with major resection than in the group with local resection (p=0.016). Moderately or strongly positive expression of c-met protein was observed in 27 cancerous regions (27/31), and only in 5 paracancerous regions. The intensive expression of c-met MRNA was 100% (31/31) detectable in the cancerous tissues, but only 22.6% (7/31) in the paracancerous tissues. C-met protein expression in cancerous tissues was correlated with portal vein tumour thrombi, cholangiocarcinoma and tumour recurrence or metastases, and the expression in paracancerous tissues was correlated with node cirrhosis. No significant correlation was observed between the hepatocyte growth factor in serum and c-met in cancerous tissues.

CONCLUSION

The over-expressions of the hepatocyte growth factor and c-met indicates an adverse prognosis for patients with liver cancer. The sustained high level of serum hepatocyte growth factor after hepatectomy may be a factor related to early tumour recurrence and metastasis. Liver regeneration may be a main factor leading to high level of serum hepatocyte growth factor in early postoperative stage.

Employment of liver tissue slice analysis to assay hepatotoxicity linked to replicative and nonreplicative adenoviral agents

Whereas virotherapy has emerged as a novel and promising approach for neoplastic diseases, appropriate model systems have hampered preclinical evaluation of candidate conditionally replicative adenovirus agents (CRAds) with respect to liver toxicity. This is due to the inability of human viral agents to cross species. We have recently shown the human liver tissue slice model to be a facile means to validate adenoviral replication. On this basis, we sought to determine whether our ex vivo liver tissue slice model could be used to assess CRAd-mediated liver toxicity. We analyzed and compared the toxicity of a conditionally replicative adenovirus (AdDelta24) to that of a replication incompetent adenovirus (Adnull [E1-]) in mouse and human liver tissue slices. To accomplish this, we examined the hepatic apoptosis expression profile by DNA microarray analyses, and compared these results to extracellular release of aminotransferase enzymes, along with direct evidence of apoptosis by caspase-3 immunhistochemical staining and TUNEL assays. Human and mouse liver tissue slices demonstrated a marked increase in extracellular release of aminotransferase enzymes on infection with AdDelta24 compared to Adnull. AdDelta24-mediated liver toxicity was further demonstrated by apoptosis induction, as detected by caspase-3 immunohistochemical staining, TUNEL assay and microarray analysis. In conclusion, concordance of CRAd-mediated apoptosis in both the human and the mouse liver tissue slice models was demonstrated, despite the limited replication ability of CRAds in mouse liver slices. The results of this study, defining the CRAd-mediated apoptosis gene expression profiles in human and mouse liver, may lay a foundation for preclinical liver toxicity analysis of CRAd agents.

Differential gene expression modulated by the cytoplasmic domain of Fc gamma RIa (CD64) alpha-chain

The cytoplasmic domain (CY) of the ligand-binding alpha-chain of the gamma-chain-associated FcRs can modulate receptor function such as phagocytosis, endocytosis, and intracellular trafficking of receptor-Ag complexes. To assess the potential role of the CY domain of human FcgammaRIa (CD64) alpha-chain in the transcriptional regulation of receptor-induced gene expression, we developed stably transfected murine macrophage cell lines expressing a full-length or a CY deletion mutant (tail-less) of human FcgammaRIa to analyze gene expression in response to receptor-specific cross-linking. Using the Affymetrix murine genome U74Av2 GeneChip array, we observed >100 candidate genes having > or =2-fold difference expression at 1.5 and 3 h after stimulation. Focusing on several immunologically related genes, we confirmed differential expression of M-CSF, macrophage inhibitory cytokine-1, leukocyte-specific protein 1, MIP-2, and IL-1R antagonist by RT-PCR and RNase protection assays. Analysis of mRNA stability indicated that the differential regulation of gene expression by the CY of the CD64 alpha-chain is at the level of gene transcription. Our results indicate that the CY of the CD64 alpha-chain modulates transcriptional activity induced by receptor-specific engagement in macrophages and provides a framework for understanding distinct expression profiles elicited by different Fc gamma-chain-associated receptors.

[The medium conditioned incubation with rat heart cells maintains the properties of ES cells]

17 kinds of conditioned media were selected by plating tests, propagation and other tests with two cell lines, C-19-2 and MESPU-13. The results suggested that the rat heart cells conditioned media (RH-CM) can inhibit the spontaneous differentiation effectively, maintain the normal diploid karyotypes and promote adherence and proliferation of mouse ES cells. The ES cells were propagated in RH-CM to the 20th passage remaining their pluripotent in vivo and in vitro differentiation ability. RH-CM can be used as supplement of ES cell media. ES cells which are cultured in media containing 70% RH-CM and on PMEF feeder can maintain their undifferentiation state and diploid karyotype. RT-PCR detection suggested that there was mLIF expression in rat heart cells.

Overexpression of GDNF induces and maintains hyperinnervation of muscle fibers and multiple end-plate formation

This study examined the role of glial cell line-derived neurotrophic factor (GDNF) in synaptic plasticity at the developing neuromuscular junction. Transgenic mice overexpressing GDNF in skeletal muscle under the myosin light chain-1 promoter were isolated. Northern blot and ELISA at 6 weeks of age indicated that GDNF mRNA and protein levels were elevated threefold in the lateral gastrocnemius muscle (LGM) of the GDNF-transgenic animals. Histochemical examination of LGM tissue sections at 6 weeks of age revealed a 70% increase in the number of cholinesterase-positive end plates without changes in end-plate area. Multiple end plates on a single muscle fiber were also observed, in addition to multiple axonal processes terminating on individual end plates. No change in the number of spinal motoneurons, overall LGM size, or muscle type composition was observed. Finally, overexpression of GDNF in muscle caused hypertrophy of neuronal somata in dorsal root ganglia without affecting their number. These findings demonstrate that overexpression of a single neurotrophic factor in skeletal muscle induces multiple end-plate formation and maintains hyperinnervation well beyond the normal developmental period. We suggest that GDNF, a muscle-derived motoneuron neurotrophic factor, serves an important role in the regulation of synaptic plasticity in the developing and adult neuromuscular junction.

Lobeline inhibits the neurochemical and behavioral effects of amphetamine

Lobeline interacts with the dopamine transporter and vesicular monoamine transporter, presynaptic proteins involved in dopamine storage and release. This study used rodent models to assess lobeline-induced inhibition of the neurochemical and behavioral effects of amphetamine. Rat striatal slices were preloaded with [(3)H]dopamine and superfused with lobeline for 30 min, and then with d-amphetamine (0.03-3.00 microM) plus lobeline for 60 min. As predicted, lobeline (1-3 microM) intrinsically increased (3)H overflow but did not inhibit d-amphetamine-evoked (3)H overflow. Consequently, the effect of lobeline on d-amphetamine-evoked endogenous dopamine and dihydroxyphenylacetic acid overflow was assessed. Lobeline (0.1-1 microM) inhibited d-amphetamine (1 microM)-evoked dopamine overflow but did not inhibit electrically evoked (3)H overflow, indicating a selective inhibition of this effect of d-amphetamine. To determine whether the in vitro results translated into in vivo inhibition, the effect of lobeline (0.3-10.0 mg/kg) pretreatment on d-amphetamine (0.1-1.0 mg/kg)-induced hyperactivity in rats and on d-methamphetamine (0.1-3.0 mg/kg)-induced hyperactivity in mice was determined. Doses of lobeline that produced no effect alone attenuated the stimulant-induced hyperactivity. Lobeline also attenuated the discriminative stimulus properties of d-methamphetamine in rats. Acute, intermittent, or continuous in vivo administration of lobeline (1-30 mg/kg) did not deplete striatal dopamine content. Thus, lobeline inhibits amphetamine-induced neurochemical and behavioral effects, and is not toxic to dopamine neurons. These results support the hypothesis that lobeline redistributes dopamine pools within the presynaptic terminal, reducing pools available for amphetamine-induced release. Collectively, the results support a role for lobeline as a potential pharmacotherapy for psychostimulant abuse.

Acute and chronic effects of nornicotine on locomotor activity in rats: altered response to nicotine

RATIONALE

Nicotine, a tobacco alkaloid, is known to be important in the acquisition and maintenance of tobacco smoking. Nornicotine, an active nicotine metabolite, stimulates nicotinic receptors and may produce psychomotor effects similar to nicotine.

OBJECTIVE

The present study determined the effects of acute and repeated administration of nornicotine on locomotor activity and compared its effects with those of nicotine.

METHODS

R(+)-Nornicotine (0.3-10 mg/kg), S(-)-nornicotine (0.3-10 mg/kg), S(-)-nicotine (0.1-1 mg/kg) or saline was administered s.c. to rats acutely or repeatedly (eight injections at 48-h intervals). Activity was recorded for 50 min immediately after each injection.

RESULTS

S(-)-Nicotine produced transient hypoactivity, followed by dose-related hyperactivity. Repeated S(-)-nicotine administration resulted in tolerance to the hypoactivity and sensitization to the hyperactivity. Subsequent testing following a saline injection revealed evidence of conditioned hyperactivity. Acute administration of 0.3 mg/kg or 1 mg/kg R(+)- or S(-)-nornicotine produced no effect. Transient hypoactivity was observed at 3 mg/kg and 10 mg/kg R(+)-nornicotine and at 10 mg/kg S(-)-nornicotine. However, rebound hyperactivity was not observed following acute administration of either nornicotine enantiomer, suggesting that nornicotine-induced psychomotor effects differ qualitatively from those of S(-)-nicotine. Repeated R(+)-nornicotine resulted in tolerance to the transient hypoactivity, however hyperactivity was not observed. Repeated S(-)-nornicotine resulted in tolerance to the hypoactivity and the appearance of hyperactivity. Repeated administration of either nornicotine enantiomer resulted in a dose-dependent alteration in response to a 1 mg/kg S(-)-nicotine challenge, suggesting some commonalities in the mechanism of action.

CONCLUSION

Nornicotine likely contributes to the neuropharmacological effects of nicotine and tobacco use.