The CHK1 inhibitor prexasertib in BRCA wild-type platinum-resistant recurrent high-grade serous ovarian carcinoma: a phase 2 trial

The multi-cohort phase 2 trial NCT02203513 was designed to evaluate the clinical activity of the CHK1 inhibitor (CHK1i) prexasertib in patients with breast or ovarian cancer. Here we report the activity of CHK1i in platinum-resistant high-grade serous ovarian carcinoma (HGSOC) with measurable and biopsiable disease (cohort 5), or without biopsiable disease (cohort 6). The primary endpoint was objective response rate (ORR). Secondary outcomes were safety and progression-free survival (PFS). 49 heavily pretreated patients were enrolled (24 in cohort 5, 25 in cohort 6). Among the 39 RECISTv1.1-evaluable patients, ORR was 33.3% in cohort 5 and 28.6% in cohort 6. Primary endpoint was not evaluable due to early stop of the trial. The median PFS was 4 months in cohort 5 and 6 months in cohort 6. Toxicity was manageable. Translational research was an exploratory endpoint. Potential biomarkers were investigated using pre-treatment fresh biopsies and serial blood samples. Transcriptomic analysis revealed high levels of DNA replication-related genes (POLA1, POLE, GINS3) associated with lack of clinical benefit [defined post-hoc as PFS < 6 months]. Subsequent preclinical experiments demonstrated significant cytotoxicity of POLA1 silencing in combination with CHK1i in platinum-resistant HGSOC cell line models. Therefore, POLA1 expression may be predictive for CHK1i resistance, and the concurrent POLA1 inhibition may improve the efficacy of CHK1i monotherapy in this hard-to-treat population, deserving further investigation.

AKT1 interacts with DHX9 to Mitigate R Loop-Induced Replication Stress in Ovarian Cancer

PARP inhibitor (PARPi)-resistant BRCA-mutant (BRCAm) high-grade serous ovarian cancer (HGSOC) represents a new clinical challenge with unmet therapeutic needs. Here, we performed a quantitative high-throughput drug combination screen that identified the combination of an ATR inhibitor (ATRi) and an AKT inhibitor (AKTi) as an effective treatment strategy for both PARPi-sensitive and PARPi-resistant BRCAm HGSOC. The ATRi and AKTi combination induced DNA damage and R loop-mediated replication stress (RS). Mechanistically, the kinase domain of AKT1 directly interacted with DHX9 and facilitated recruitment of DHX9 to R loops. AKTi increased ATRi-induced R loop-mediated RS by mitigating recruitment of DHX9 to R loops. Moreover, DHX9 was upregulated in tumors from patients with PARPi-resistant BRCAm HGSOC, and high coexpression of DHX9 and AKT1 correlated with worse survival. Together, this study reveals an interaction between AKT1 and DHX9 that facilitates R loop resolution and identifies combining ATRi and AKTi as a rational treatment strategy for BRCAm HGSOC irrespective of PARPi resistance status.

SIGNIFICANCE

Inhibition of the AKT and ATR pathways cooperatively induces R loop-associated replication stress in high-grade serous ovarian cancer, providing rationale to support the clinical development of AKT and ATR inhibitor combinations. See related commentary by Ramanarayanan and Oberdoerffer, p. 793.

Analyses of Neural Circuits Governing Behavioral Plasticity in the Nematode Caenorhabditis elegans

Behavioral plasticity is subjected to various sensory stimuli, experiences, and physiological states, representing the temporal and spatial patterns of neural circuit dynamics. Elucidation of how genes and neural circuits in our brain actuate behavioral plasticity requires functional imaging during behavioral assays to manifest temporal and spatial neural regulation in behaviors. The exploration of the nervous systems of Caenorhabditis elegans has catalyzed substantial scientific advancements in elucidating the mechanistic link between circuit dynamics and behavioral plasticity. The analyses of the nervous system of C. elegans have technologically flourished owing to the development of optogenetic instruments and fluorescent protein-based imaging compatible with its optically transparent body and the understanding of its completely revealed neural connectome and gene expression profiles at single-neuron resolution (The C. elegans Neuronal Gene Expression Map & Network, CeNGEN project). Using examples of the two temperature learning behaviors in C. elegans, this chapter delves into a selection of pivotal imaging tools, including genetically encoded calcium indicators, biosensors for second messenger imaging, and their usage in freely moving worms that have propelled our grasp of sensory representation in C. elegans neural circuits. To further connect the circuit dynamics to behavioral plasticity, this chapter will focus on technological advancements enabling simultaneous imaging and tracking system together with methodologies to quantify multiple behavioral elements of freely behaving C. elegans in a dynamic environment.

Analyses of Genetic Regulation of the Nervous System in the Nematode Caenorhabditis elegans

This chapter aims to provide a comprehensive overview of the methodologies available to dissect genetic regulation of the nervous systems in the nematode Caenorhabditis elegans. These techniques encompass genetic screens and genetic tools to unravel the spatial-temporal contribution of genes on neural structure and function. Unbiased genetic screens on random mutations induced by ethyl methanesulfonate (EMS) or target gene silencing by genome-wide RNA interference (RNAi) help progress our understanding of the genetic control of neural development and functions. Complement to unbiased genetic approaches, gene- and protein-targeted manipulation by Cre/LoxP recombination system and auxin-inducible degron (AID) protein degradation system, respectively, helps identify tissues/cells and the time window critical for gene and protein function during the proper execution of a particular behavior. Considering the remarkable conservation of genetic pathways between C. elegans and mammalian systems, elucidating the genetic underpinnings of neural functions and learning behaviors in C. elegans may furnish invaluable insights into analogous processes in more complex organisms. As shown in the following chapter, leveraging these diverse methodologies enable researchers to elucidate the intricate network governing neural function and structure, laying the foundation for innovating strategies to ameliorate cognitive alterations.

Prediction of extranodal extension in head and neck squamous cell carcinoma by CT images using an evolutionary learning model

BACKGROUND

Extranodal extension (ENE) in head and neck squamous cell carcinoma (HNSCC) correlates to poor prognoses and influences treatment strategies. Deep learning may yield promising performance of predicting ENE in HNSCC but lack of transparency and interpretability. This work proposes an evolutionary learning method, called EL-ENE, to establish a more interpretable ENE prediction model for aiding clinical diagnosis.

METHODS

There were 364 HNSCC patients who underwent neck lymph node (LN) dissection with pre-operative contrast-enhanced computerized tomography images. All the 778 LNs were divided into training and test sets with the ratio 8:2. EL-ENE uses an inheritable bi-objective combinatorial genetic algorithm for optimal feature selection and parameter setting of support vector machine. The diagnostic performances of the ENE prediction model and radiologists were compared using independent test datasets.

RESULTS

The EL-ENE model achieved the test accuracy of 80.00%, sensitivity of 81.13%, and specificity of 79.44% for ENE detection. The three radiologists achieved the mean diagnostic accuracy of 70.4%, sensitivity of 75.6%, and specificity of 67.9%. The features of gray-level texture and 3D morphology of LNs played essential roles in predicting ENE.

CONCLUSIONS

The EL-ENE method provided an accurate, comprehensible, and robust model to predict ENE in HNSCC with interpretable radiomic features for expanding clinical knowledge. The proposed transparent prediction models are more trustworthy and may increase their acceptance in daily clinical practice.

Differential impacts of initial treatment status on long-term survival in patients with sarcomas treated in a referral center according to histologic type and anatomic site

OBJECTIVE

The aim of this work was to estimate the magnitude of the differential impacts of initial treatment status relative to the impact of classic clinicopathologic factors on the long-term overall survival (OS) of sarcoma patients in a referral cancer center.

METHODS

From the institutional database, we identified 2185 patients who presented to the institutional multidisciplinary team (MDT) prior to (N = 717, 32.8%) or after (N = 1468, 67.2%) initial treatment, with a first diagnosis of sarcoma from January 1999 to December 2018. Descriptive, univariate and multivariate analyses were applied to identify the factors related to OS. By performing propensity score matching of each completely MDT-treated patient to a referral patient with similar characteristics, the differential impacts of the identified risk and prognostic factors on OS in the 2 groups were estimated by the Kaplan‒Meier survival curves, log-rank test and Cox proportional hazard regression; the results were compared using calibrated nomograph models and forest plots.

RESULTS

Adjusted for the clinicopathologic factors of patient age, sex, primary site, tumor grade, tumor size, resection margin and histology, hazard ratio-based modeling analysis indicated that the initial treatment status was an independent but intermediate prognostic factor associated with long-term OS. The major impacts of the initial and comprehensive MDT-based management on significant improvement of the 20-year OS of sarcomas were reflected in the subgroup of patients with stromal, undifferentiated pleomorphic, fibromatous, fibroepithelial, or synovial neoplasms and tumors in the breast, gastrointestinal tract, or soft tissues of limb and trunk.

CONCLUSIONS

This retrospective study supports early referral of patients with soft tissue masses of unknown identity to a specialized MDT before biopsy and initial resection to reduce the risk of death but highlights an unmet need for a greater understanding of some of the most difficult sarcoma subtypes and subsites and their management.

Quantitative Assessment of Lipiodol-Related Artifact Reduction for Dual-Energy Computed Tomography After Transcatheter Arterial Chemoembolization: A Phantom Study Evaluating the Use of Metal Artifact Reduction Algorithms

OBJECTIVE

This study used metal artifact reduction (MAR) software to examine the computed tomography (CT) number of dual-energy CT (DECT) of hepatocellular carcinoma after transcatheter arterial chemoembolization.

METHODS

Hollow columnar acrylic phantoms were filled with lipiodol and inserts of 2 sizes (large and small) were used to simulate liver tumors on a Revolution GSI CT scanner. The CT numbers of a single test object were collected twice: once with and once without the MAR algorithm. Lipiodol beam-hardening artifacts were quantified by measuring CT numbers in a region of interest around the tumor-simulating insert.

RESULTS

The virtual monochromatic CT numbers of large and small tumors were closely related to energy. For small tumors, CT numbers increased with energy. For large tumors, CT numbers increased with energy at 1 cm from the margin but decreased with an increase in energy at 5 cm. Regardless of the size, distance, or location of the tumor, the CT numbers fluctuated more at low energy levels.

CONCLUSIONS

At 1 cm from the margin, the CT numbers with MAR were significantly different from those without MAR. Low-energy CT numbers with MAR were near reference values. Metal artifact reduction exhibited superior performance for small tumors. Tumor margin images are affected by artifacts caused by Lipiodol. However, with MAR, CT numbers can be effectively calibrated, thus enabling clinicians to more accurately evaluate hepatocellular carcinoma development and identify residual tumors and recurrent or metastatic lesions.

BLM overexpression as a predictive biomarker for CHK1 inhibitor response in PARP inhibitor-resistant BRCA-mutant ovarian cancer

Poly(ADP-ribose) polymerase inhibitors (PARPis) have changed the treatment paradigm in breast cancer gene (BRCA)-mutant high-grade serous ovarian carcinoma (HGSC). However, most patients eventually develop resistance to PARPis, highlighting an unmet need for improved therapeutic strategies. Using high-throughput drug screens, we identified ataxia telangiectasia and rad3-related protein/checkpoint kinase 1 (CHK1) pathway inhibitors as cytotoxic and further validated the activity of the CHK1 inhibitor (CHK1i) prexasertib in PARPi-sensitive and -resistant BRCA-mutant HGSC cells and xenograft mouse models. CHK1i monotherapy induced DNA damage, apoptosis, and tumor size reduction. We then conducted a phase 2 study (NCT02203513) of prexasertib in patients with BRCA-mutant HGSC. The treatment was well tolerated but yielded an objective response rate of 6% (1 of 17; one partial response) in patients with previous PARPi treatment. Exploratory biomarker analyses revealed that replication stress and fork stabilization were associated with clinical benefit to CHK1i. In particular, overexpression of Bloom syndrome RecQ helicase (BLM) and cyclin E1 (CCNE1) overexpression or copy number gain/amplification were seen in patients who derived durable benefit from CHK1i. BRCA reversion mutation in previously PARPi-treated BRCA-mutant patients was not associated with resistance to CHK1i. Our findings suggest that replication fork-related genes should be further evaluated as biomarkers for CHK1i sensitivity in patients with BRCA-mutant HGSC.

Regorafenib induces damage-associated molecular patterns, cancer cell death and immune modulatory effects in a murine triple negative breast cancer model

Damage associated molecular patterns (DAMPs), including calreticulin (CRT) exposure, high-mobility group box 1 protein (HMGB1) elevation, and ATP release, characterize immunogenic cell death (ICD) and may play a role in cancer immunotherapy. Triple negative breast cancer (TNBC) is an immunogenic subtype of breast cancer with higher lymphocyte infiltration. Here, we found that regorafenib, a multi-target angiokinase inhibitor previously known to suppress STAT3 signaling, induced DAMPs and cell death in TNBC cells. Regorafenib induced the expression of HMGB1 and CRT, and the release of ATP. Regorafenib-induced HMGB1 and CRT were attenuated following STAT3 overexpression. In a 4T1 syngeneic murine model, regorafenib treatment increased HMGB1 and CRT expression in xenografts, and effectively suppressed 4T1 tumor growth. Immunohistochemical staining revealed increased CD4⁺ and CD8⁺ tumor-infiltrating T cells in 4T1 xenografts following regorafenib treatment. Regorafenib treatment or programmed death-1 (PD-1) blockade using anti-PD-1 monoclonal antibody reduced lung metastasis of 4T1 cells in immunocompetent mice. While regorafenib increases the proportion of MHC II high expression on dendritic cells in mice with smaller tumors, the combination of regorafenib and PD-1 blockade did not show a synergistic effect on anti-tumor activity. These results suggest that regorafenib induces ICD and suppresses tumor progression in TNBC. It should be carefully evaluated when developing a combination therapy with an anti-PD-1 antibody and a STAT3 inhibitor.

Nicotine activates HIF-1α and regulates acid extruders through the nicotinic acetylcholine receptor to promote the Warburg effect in non-small cell lung cancer cells

Cigarette smoking is the greatest risk factor for lung cancer, accounting for approximately 90% of all lung cancer-related deaths. Moreover, nicotine is associated with lung cancer onset and progression. Hypoxia-inducible factor 1α (HIF-1α) is involved in the metabolic reprogramming of cancer cells and accelerates cancer progression via regulation of pH and acid-base homeostasis. Previous studies have reported that nicotine upregulates HIF-1α expression. Therefore, we hypothesized that nicotine-mediated activation of HIF-1α regulates metabolic reprogramming and pH homeostasis in non-small cell lung cancer A549 cells and could potentially play a role in the progression of lung cancer. We examined the effects of nicotine on metabolic reprogramming and intracellular pH (pH_i) homeostasis, which are critical for cancer progression. A549 cells were exposed to nicotine in the absence and presence of the nicotinic acetylcholine receptor antagonist, mecamylamine (MEC). We then analyzed glycolytic stress and the activity and expression of acid-extruder proteins, including the Na⁺-H⁺ exchanger 1 (NHE1) and monocarboxylate cotransporters 1 & 4 (MCT1 and MCT4, respectively). Nicotine promoted the Warburg effect, which is associated with accelerated migration of A549 cells through the activation of nicotinic acetylcholine receptors. Furthermore, nicotine upregulated the activities and expression of acid-extruder proteins, namely NHE1 and MCT4, and facilitated glycolysis. To the best of our knowledge, this is the first study to demonstrate that nicotine plays a pivotal regulatory role in metabolic reprogramming as well as regulation of pH_i homeostasis in A549 cells via activation of nicotinic acetylcholine receptors and can therefore aggravate lung cancer progression.

Abstract 6173: AKT1 prevents aberrant R-loops accumulation via regulating DHX9 and suppresses transcription-replication collision in PARP inhibitor-resistant ovarian cancer

Background: Acquired resistance to PARP inhibitors (PARPis) is a pressing problem in high-grade serous ovarian cancer (HGSC), highlighting the development of novel therapeutic options. To address this unmet need, we conducted high-throughput drug combination screens in PARPi-resistant HGSC cells using ATR inhibitor (ATRi), given that ATR/CHK1 signaling activation is one of the main mechanisms of PARPi resistance. In the screens, PI3K/AKT pathway inhibitors were synergistic with ATRi. Mechanistically, ATR signaling plays a major role in R-loop dynamics and replication stress (RS) response pathways, but the role of AKT is unclear. Here, we aim to investigate AKT’s role in R-loop-mediated RS in PARPi-resistant HGSC cells. We also hypothesize that AKT inhibitor (AKTi) would augment ATRi-induced R-loop formation by reducing the expression of helicases.

Methods: We used PARPi-resistant variants and parental PEO1 as a negative control. ATRi (ceralasertib) and AKTi (capivasertib) were used for further mechanistic studies. Induction of RS, DNA double-strand break, and R-loop were evaluated using immunofluorescence staining for markers pRPA, γH2AX, and S9.6, respectively. We measured multiple nuclear helicases and in situ DHX9-R-loop interaction by western blot and proximity ligation assay. DHX9-AKT1 interaction was confirmed by co-immunoprecipitation. All data were repeated in triplicate, analyzed using one-way ANOVA test, and shown as mean ± SD. P &lt; 0.05 was considered statistically significant.

Results: The ATRi and AKTi combination induced greater RS, as evidenced by a 1.7-12.0-fold increase in pRPA+/γH2AX+ population relative to each drug alone. Adding AKTi to ATRi significantly increased R-loops compared to monotherapy alone (signal intensity 14-19 x 105 vs. 9.9-14.6 x 105, P &lt; 0.001), suggesting that AKT also contributes to R-loop dissolution. Moreover, the combination showed a higher percentage of cells with γH2AX and R-loops relative to monotherapy (54.7-75.4% vs. 33.3-49.0%, P &lt; 0.001) in the presence of pan-caspase inhibitor, indicating the increased DNA damage is unlikely caused by increased apoptosis but by R-loop accumulation. Also, AKTi addition to ATRi significantly reduced the nuclear DHX9 among other helicases. Moreover, we found that AKT1 directly binds with DHX9 via its kinase domain and couples with DHX9 to resolve R-loops.

Conclusion: Our data suggest ATRi and AKTi combination could be a new therapeutic combination in HGSC with PARPi resistance. Mechanistically, our data reveal a previously unknown direct role of AKT1 and its interaction with DHX9 in R-loop resolution besides ATR.

Citation Format: Tzu-Ting Huang, Chih-Yuan Chiang, Jayakumar R. Nair, Chi-Ting Shih, Kelli Wilson, Ken Chih-Chien Cheng, Jung-Min Lee. AKT1 prevents aberrant R-loops accumulation via regulating DHX9 and suppresses transcription-replication collision in PARP inhibitor-resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6173.

Abstract 1562: Correlative biomarker analysis of the phase II study of prexasertib, a cell cycle checkpoint kinase 1 (CHK1) inhibitor, in BRCA wild-type (BRCAwt), platinum-resistant recurrent, high-grade serous ovarian cancer (PR-HGSOC)

Background: High unmet needs exist to develop novel therapeutics and identify biomarkers to predict response in PR-HGSOC. We previously reported clinical activity of CHK1 inhibitor (CHK1i), prexasertib (a.k.a.ACR-368) in heavily pretreated BRCAwt PR-HGSOC (response rate [RR]: 30.7%, median progression free survival [PFS]: 5.8 [1.7-26.4] months; NCT02203513). Here, we aim to identify molecular correlates to CHK1i treatment.

Methods: Prexasertib was given at 105 mg/m2 IV every 14 days in a 28-day cycle. Pre-treatment fresh core biopsies were collected from the biopsy cohort for RNA sequencing (RNAseq) and Whole Exome Sequencing (WES). Gene Set Enrichment Analysis (GSEA) and WES analysis were performed to identify molecular features that might predict response/resistance to CHK1i. Blood samples were collected at baseline and cycle 1 day 15 (C1D15) from both biopsy and non-biopsy cohorts. Multiparametric flow cytometry evaluating immune cell subsets was performed to identify changes in the immune response. Comparison of correlative markers was performed using a non-parametric Mann-Whitney test (GraphPad Prism, V9).

Results: 49 BRCAwt PR-HGSOC patients (median 4 prior therapies [IQR 3-7]) were enrolled in both cohorts (biopsy cohort: n=25 and non-biopsy cohort: n=24) and received at least one dose of prexasertib. Among 39 RECIST evaluable patients, 18 had clinical benefit (CB), defined by PFS&gt;6months. Tissue samples were obtained from 15 evaluable patients (biopsy cohort), and blood samples from 39 evaluable patients (both cohorts). While WES analysis did not reveal correlation between treatment response and genetic variants, GSEA showed insulin-like growth factor 1 (IGF1)/insulin pathway, nucleotide excision repair (NER), and homologous recombination (HR) pathways enriched in patients with no clinical benefit (NCB; PFS&lt;6months). Upregulation of gene expression belonging to IGF1/insulin pathway was found in patients with NCB, i.e., IGF1R (p=0.02), IGF2BP3 (p=0.04), SLC2A4 (p=0.01), as well as genes belonging to the NER pathway, i.e., POLE (p=0.03) and RAD23A (p=0.02). Flow cytometry analysis showed an increase in the percentage of monocytic myeloid-derived suppressor cells (M-MDSCs) during CHK1i treatment in the NCB group (median 3.67% [0-15.9%] at baseline vs 7.8% [1.97-25.00%] at C1D15; p=0.009). Also, a higher percentage of M-MDSCs on C1D15 was found in NCB compared to the CB group (median 7.8% [1.97-25%] vs 5.52% [0.93-17.6%]; p=0.03).

Conclusions: CHK1i yields promising clinical benefit in BRCAwt, PR-HGSOC, hard-to-treat population. Our preliminary biomarker analyses suggest that tumoral upregulation of IGF1/insulin and DNA repair pathways as well as a systemic increase of immunosuppressive cells, e.g., M-MDSCs may negatively impact CHK1i response.

Citation Format: Elena Giudice, Grant Zurcher, Jayakumar Nair, Tzu-Ting Huang, Min-Jung Lee, Jane B. Trepel, Jung-Min Lee. Correlative biomarker analysis of the phase II study of prexasertib, a cell cycle checkpoint kinase 1 (CHK1) inhibitor, in BRCA wild-type (BRCAwt), platinum-resistant recurrent, high-grade serous ovarian cancer (PR-HGSOC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1562.

The optimal intervention for preventing physical restraints among older adults living in the nursing home: A systematic review

AIM

This study aimed to evaluate the effectiveness of restraint reduction programs for nursing home care providers in enforcing physical restraint on residents and identify the best strategies for such programs.

DESIGN

Systematic Review.

METHODS

We searched for randomized controlled trials published until February 2021 for systematic review. The systematic review captured multifactorial interventions, education and consultation measures, including nursing home residents' and care providers' results. Study quality was assessed using the Cochrane Collaboration criteria.

RESULTS

In all seven trials, the interventions were led by a nurse specialist or unit leader and targeted at care providers. Five of the restraint reduction programs effectively reduced the rate of physical restraint use; two increased knowledge of restraint reduction for care providers; and one each promoted positive attitudes and behaviours. Duration of at least 6 weeks significantly improved the knowledge of care providers.

Rupture of a non sinus of Valsalva aneurysm during pregnancy: Case report and review of literatures

Ruptured Sinus of Valsalva aneurysms during pregnancy is rare and presents a threat both to the mother and the fetus. We report a case of ruptured nonsinus of Valsalva aneurysms in a 26-year-old woman diagnosed at 32⁺⁴ weeks of gestation. A successful elective lower-segment cesarean section was conducted under general anesthesia. A successful surgical correction of the ruptured aneurysm under cardiopulmonary bypass (CPB) was performed with patch repair after 13 days. A multidisciplinary approach with respect to the pregnant patient's diagnosis, indications, and timing of surgery is necessary in ensuring the best possible outcomes for both the mother and the child.

Distinct roles of treatment schemes and BRCA2 on the restoration of homologous recombination DNA repair and PARP inhibitor resistance in ovarian cancer

Poly (ADP-ribose) polymerase inhibitors (PARPis) represent a major advance in ovarian cancer, now as a treatment and as a maintenance therapy in the upfront and recurrent settings. However, patients often develop resistance to PARPis, underlining the importance of dissecting resistance mechanisms. Here, we report different dosing/timing schemes of PARPi treatment in BRCA2-mutant PEO1 cells, resulting in the simultaneous development of distinct resistance mechanisms. PARPi-resistant variants PEO1/OlaJR, established by higher initial doses and short-term PARPi treatment, develops PARPi resistance by rapidly restoring functional BRCA2 and promoting drug efflux activity. In contrast, PEO1/OlaR, developed by lower initial doses with long-term PARPi exposure, shows no regained BRCA2 function but a mesenchymal-like phenotype with greater invasion ability, and exhibits activated ATR/CHK1 and suppressed EZH2/MUS81 signaling cascades to regain HR repair and fork stabilization, respectively. Our study suggests that PARPi resistance mechanisms can be governed by treatment strategies and have a molecular basis on BRCA2 functionality. Further, we define different mechanisms that may serve as useful biomarkers to assess subsequent treatment strategies in PARPi-resistant ovarian cancer.

Interfering B cell receptor signaling via SHP-1/p-Lyn axis shows therapeutic potential in diffuse large B-cell lymphoma

Background

Diffuse large B cell lymphoma (DLBCL) is an aggressive and molecularly heterogeneous non-Hodgkin’s lymphoma. The B cell receptor (BCR) signaling pathway in DLBCL emerges as a new drug target. Protein phosphatase SHP-1 negatively regulates several oncogenic tyrosine kinases and plays a tumor suppressive role.

Methods

The direct SHP-1 agonists were used to evaluate the potential therapeutic implication of SHP-1 in DLBCL. Immunohistochemical staining for SHP-1 was quantified by H-score. The SHP-1 phosphatase activity was determined using tyrosine phosphatase assay. In vitro studies, including MTT, western blot analysis and cell apoptosis, were utilized to examined biological functions of SHP-1.

Results

Oral administration of SHP-1 agonist showed the potent anti-tumor effects compared to a selective Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib in mice bearing U2932 xenografts. SHP-1 agonist increased SHP-1 activity as well as downregulated p-Lyn in vivo. Here, we demonstrated that immunohistochemical staining for SHP-1 expression was positive in 76% of DLBCL samples. SHP-1 agonist exerted anti-proliferative and apoptotic effects compared with ibrutinib in DLBCL cells. Mechanistically, SHP-1 agonist decreased BCR signaling, especially p-Lyn, and led to apoptosis.

Conclusions

These data suggest that SHP-1 negatively regulates phosphorylation of Lyn, and targeting SHP-1/p-Lyn using SHP-1 agonist has therapeutic potential for treatment of DLBCL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00518-0.

Abstract 5408: Targeting ATR and AKT pathways promotes cell death in PARP inhibitor-resistant ovarian cancer cells by increasing DNA damage and lethal replication stress

Poly (ADP-ribose) polymerase inhibitors (PARPis) have changed the treatment paradigm in the management of high-grade serous ovarian cancer (HGSOC). However, most HGSOC ultimately develops resistance to PARPi, leading to unmet medical needs for better therapeutic strategies. ATR-mediated G2/M cell cycle checkpoints are important for cell survival and DNA repair, especially in HGSOC due to its dysfunctional p53-mediated G1/S checkpoint, making them an attractive therapeutic target. However, only modest monotherapy activity of ATR inhibitors (ATRis) has been reported in patients with HGSOC, highlighting the need for combination treatment. We conducted a high-throughput drug combination screen of ATRi (ceralasertib) with 1,912 drugs in two PARPi-resistant BRCA2-mutant PEO1 (PEO1/OlaR and PEO1/OlaJR) HGSOC cell lines. In this screen, 234 drugs showed synergistic cytotoxicity with ATRi, including 31 (13.2%) cell cycle checkpoint inhibitors, 27 (11.5%) chemotherapeutic drugs, and 13 (5.6%) PI3K/AKT pathway inhibitors. We prioritized the PI3K/AKT pathway inhibitors for ATRi combination because the PI3K/AKT pathway is upregulated in &gt;70% of HGSOC and associated with an aggressive phenotype. Moreover, PI3K/AKT signaling is found to be activated in HGSOC cells with PARPi resistance. We separately validated that an ATRi (ceralasertib &lt; 1 μM) in combination with an AKT inhibitor (AKTi; capivasertib &lt; 10 μM) yielded additive/synergistic cytotoxic effects (combination index &lt; 1) in various HGSOC cell lines, including acquired and de novo PARPi-resistant (PEO1/OlaR, PEO1/OlaJR, and PEO4) and platinum-resistant HGSOC cell lines (OVCAR3), by XTT and colony formation assays. With clinically attainable concentrations of ATRi (1 μM) and AKTi (10 μM), the combination treatment increased cell apoptosis compared to ATRi (increased 2.1 to 95.2-fold; P &lt; 0.001) or AKTi alone (increased 3.3 to 92.2-fold; P &lt; 0.001) in both PARPi-sensitive and -resistant HGSOC cells. ATRi+AKTi treatment also showed greater DNA damage as evidenced by increased percentage of cells with ≥ 5 γH2AX foci relative to ATRi (increased 1.1 to 7.6-fold; not significant in PEO1 and P &lt; 0.001 in PARPi-resistant cells) or AKTi (increased 2.3 to 6.2-fold; P &lt; 0.001) in both PARPi-sensitive and -resistant cells. Furthermore, ATRi+AKTi treatment augmented replication stress as measured by increased phospho-RPA+/γH2AX+ populations compared with ATRi (increased 1.7 to 4.7-fold; P &lt; 0.001) or AKTi (increased 3.7 to 12.0-fold; P &lt; 0.001). Overall, our results suggest that dual inhibition of ATR and AKT pathways results in greater cell death by increasing DNA damage and replication stress in HGSOC cells with PARPi resistance.

Citation Format: Tzu-Ting Huang, Chih-Yuan Chiang, Nitasha Gupta, Kelli Wilson, Ken Chih-Chien Cheng, Jung-Min Lee. Targeting ATR and AKT pathways promotes cell death in PARP inhibitor-resistant ovarian cancer cells by increasing DNA damage and lethal replication stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5408.

Vacuum ultraviolet nonlinear metalens

Vacuum ultraviolet (VUV) light plays an essential role across science and technology, from molecular spectroscopy to nanolithography and biomedical procedures. Realizing nanoscale devices for VUV light generation and control is critical for next-generation VUV sources and systems, but the scarcity of low-loss VUV materials creates a substantial challenge. We demonstrate a metalens that both generates-by second-harmonic generation-and simultaneously focuses the generated VUV light. The metalens consists of 150-nm-thick zinc oxide (ZnO) nanoresonators that convert 394 nm (~3.15 eV) light into focused 197-nm (~6.29 eV) radiation, producing a spot 1.7 μm in diameter with a 21-fold power density enhancement as compared to the wavefront at the metalens surface. The reported metalens is ultracompact and phase-matching free, allowing substantial streamlining of VUV system design and facilitating more advanced applications. This work provides a useful platform for developing low-loss VUV components and increasing the accessibility of the VUV regime.

Cell Cycle Checkpoints and Beyond: Exploiting the ATR/CHK1/WEE1 Pathway for the Treatment of PARP Inhibitor–Resistant Cancer

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) have become a mainstay of therapy in ovarian cancer and other malignancies, including BRCA-mutant breast, prostate, and pancreatic cancers. However, a growing number of patients develop resistance to PARPis, highlighting the need to further understand the mechanisms of PARPi resistance and develop effective treatment strategies. Targeting cell cycle checkpoint protein kinases, e.g., ATR, CHK1, and WEE1, which are upregulated in response to replication stress, represents one such therapeutic approach for PARPi-resistant cancers. Mechanistically, activated cell cycle checkpoints promote cell cycle arrest, replication fork stabilization, and DNA repair, demonstrating the interplay of DNA repair proteins with replication stress in the development of PARPi resistance. Inhibitors of these cell cycle checkpoints are under investigation in PARPi-resistant ovarian and other cancers. In this review, we discuss the cell cycle checkpoints and their roles beyond mere cell cycle regulation as part of the arsenal to overcome PARPi-resistant cancers. We also address the current status and recent advancements as well as limitations of cell cycle checkpoint inhibitors in clinical trials.

Abstract P068: Different treatment schemes cause distinct PARP inhibitor resistance mechanisms in BRCA2-mutant ovarian cancer cells

Poly (ADP-ribose) polymerase inhibitors (PARPis) represent a major advance in ovarian cancer management, now as treatment for recurrent ovarian cancer and as a maintenance therapy following platinum-based chemotherapy in the upfront and platinum-sensitive recurrent settings. Yet, a growing number of patients progress through PARPis, creating a need for further understanding on resistance mechanisms. We hypothesized that different treatment dosing/timing schemes would cause distinct mechanisms of acquired resistance to PARPis. To test this hypothesis, we exposed BRCA2-mutant PEO1 ovarian cancer cells to 0.5 μM olaparib, doubling its concentration up to 40 μM over 3–4 months (PEO1/OlaJR). The second PARPi-resistant PEO1 cell line (PEO1/OlaR) was developed using a relatively low initial dose of 5 nM olaparib, and gradually increasing its concentration up to 20 μM over 6 months. To confirm PARPi resistance, cell proliferation and viability were measured by MTT and colony formation assay, respectively. Both cell lines were resistant to two different PARPis beyond clinically achievable concentrations (olaparib IC50 141.7–372.8 μM and rucaparib IC50 37.1–51.2 μM) and demonstrated restored homologous recombination (HR) repair as evidenced by increased HR-reporter activity (1.32 to 1.45-fold compared to PEO1, p &lt; 0.05) and RAD51 foci formation (5.2 to 6.1-fold compared to PEO1, p &lt; 0.001). For PEO1/OlaJR, distinct resistance mechanisms to PARPi were noted: 1) promoting drug efflux confirmed by increased MDR efflux activity (1.92-fold compared to PEO1, p &lt; 0.001) and increased protein levels of an ABCB1 transporter (7.2-fold compared to PEO1); and 2) enhancing HR repair restoration, likely via reduced REV7 protein expression (0.43-fold compared to PEO1). On the other hand, PEO1/OlaR exhibited a mesenchymal cell phenotype with greater invasion ability as measured by transwell invasion assay (2.25-fold compared to PEO1, p &lt; 0.001) and restored HR repair with upregulation of TRIP13 protein (1.85-fold compared to PEO1). PEO1/OlaR also showed increased cell survival, possibly via activation of PI3K/AKT signaling, as evidenced by increased p-AKT (2.12-fold compared to PEO1). No loss of 53BP1 was observed in either PEO1/OlaJR or PEO1/OlaR based on whole exome sequencing and immunoblotting of 53BP1. BRCA2 reversion mutation status is currently under investigation. Altogether, our findings suggest that mechanisms of resistance to PARPis arise differently based on the duration and concentrations of drug treatment, highlighting the importance of appreciating interplay between specific treatment schemes and the downstream consequences. Thus, developing tailored therapeutic strategies should consider various mechanisms of PARPi resistance.

Citation Format: Tzu-Ting Huang, Jayakumar R. Nair, Nitasha Gupta, Tomomi M. Yamamoto, Benjamin G. Bitler, Jung-Min Lee. Different treatment schemes cause distinct PARP inhibitor resistance mechanisms in BRCA2-mutant ovarian cancer cells [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P068.

[Role of the ES-62 protein derived from Acanthocheilonema viteae in regulation of immune dysregulation diseases: a review]

ES-62 is a phosphorylcholine-containing, 62 kDa glycoprotein derived from the excretory-secretory product of Acanthocheilonema viteae, which is effective for the prevention and treatment of immune dysregulation diseases through triggering activation of immune cells, such as dendritic cells, mononuclear macrophages and regulatory B cells and mediating immune responses. Recently, the role of the ES-62 protein in the management of allergic, autoimmune and metabolic diseases has been paid much attention. This review summarizes the regulatory role of the ES-62 protein in immune dysregulation diseases and the underlying mechanisms, so as to provide insights into future experimental studies.

[Analysis of components of proteins from Echinococcus granulosus cyst fluid]

OBJECTIVE

To analyze the components of proteins from Echinococcus granulosus cyst fluid using the shotgun method, and to identify the active components with potential regulatory effects for immune dysregulation diseases.

METHODS

The E. granulosus cyst fluid was collected aseptically from the hepatic cysts of patients with cystic echinococcosis, and characterized by liquid chromatography (LC) tandem mass spectrometry (MS/MS) following digestion with trypsin. The protein data were searched using the software MaxQuant version 1.6.1.0 and the cellular components, molecular functions, and biological processes of the identified proteins were analyzed using the Gene Ontology (GO) method.

RESULTS

The E. granulosus cyst fluid separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) had a relative molecular mass of 25 to 70 kDa. LS-MS/MS analysis identified 37 proteins, including 32 known proteins and 5 unknown proteins. At least 4 proteins were preliminarily found to exhibit potential regulatory effects for immune dysregulation diseases, including antigen B, glutathione-S-transferase (GST), thioredoxin peroxidase (TPX) and malate dehydrogenase (MDH). GO enrichment analysis showed that the identified proteins had 149 molecular functions and were involved in 341 biological processes.

CONCLUSIONS

E. granulosus cyst fluid has a variety of protein components, and four known proteins are preliminarily identified to be associated with immune dysregulation diseases.

Concurrent Sorafenib and Radiotherapy versus Radiotherapy Alone for Locally Advanced Hepatocellular Carcinoma: A Propensity-Matched Analysis

Purpose

Evidence is lacking concerning the benefit of the combination of sorafenib and radiotherapy to treat advanced hepatocellular carcinoma (HCC). To date, no publication has reported the outcomes of radiotherapy alone versus concurrent therapy. We aimed to compare the effectiveness of radiotherapy alone versus concurrent radiotherapy and sorafenib for locally advanced hepatocellular carcinoma.

Materials and Methods

We conducted a propensity score matching (PSM) cohort study comparing the effectiveness of the concurrent use of sorafenib and external beam radiotherapy versus radiotherapy alone in Barcelona Clinic Liver Cancer (BCLC) stage B or C, nonsurgically managed, nonmetastatic patients with HCC. Two subpopulations were matched based on baseline characteristics. Stratified analysis was also performed to assess the heterogeneous effects of the two arms. Overall survival (OS) was compared. Radiation-induced liver disease (RILD) and overt gastrointestinal (GI) bleeding events were also recorded.

Results

Seven hundred thirty-one BCLC stage B or C nonmetastatic HCC patients were identified from 2007 to 2017. Of these, 347 patients met the inclusion criteria (Radiotherapy alone: 269 patients; concurrent therapy: 78 patients). Propensity score matching yielded 73 patients each in the radiotherapy and concurrent groups. The median OS was 9.6 months in the radiotherapy-alone group and 9.9 months in the concurrent group (hazard ratio (HR): 1.12; 95% CI=0.78–1.62; p=0.544). Posttreatment toxicities, including radiation-induced liver disease and overt gastrointestinal bleeding, showed no significant differences between the groups.

Conclusion

In our study, the concurrent use of sorafenib and conventional external beam radiotherapy shows no survival benefit over radiotherapy alone for locally advanced hepatocellular carcinoma.

Risk Factors for Maternal and Perinatal Complications during Pregnancy among Women with Tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease during pregnancy. Studies of risk factors are of great significance to maternal and fetal outcomes in patients with TOF.

Aims

To identify predictive risk factors for maternal and perinatal complications in women with TOF.

Subjects and Methods

78 patients with TOF who delivered at Shanghai Obstetrical Cardiology Intensive Care Center between January 1993 and December 2017 were retrospective reviewed. A logistic regression model was used to identify risk factors for maternal and perinatal complications.

Results

There was no maternal death, five patients developed cardiac failure, sustained arrhythmias requiring treatments were recorded among 2 patients. Factors identified for maternal complications included previous cardiac events and oxygen saturation <90%. Oxygen saturation <90% was found to be independent predictor of maternal cardiac complications (RR = 21.455, 95%CI 2.186-210.572, P = 0.009). The perinatal survival rate was 87.18%, there were 52 term deliveries (66.67%). Perinatal poor outcomes include 9 therapeutic abortions (11.54%), 1 neonatal death (1.28%), 16 premature births (20.51%), 18 small for gestational age children (23.08%), 3 neonatal asphyxia (3.85%), and 3 neonatal cardiac malformations (3.85%). Factors identified for perinatal complications included without cardiac surgery, higher hemoglobin values, higher hematocrit values, oxygen saturation <90%, right ventricular hypertrophy, pulmonary stenosis, ventricular septal defect, and pulmonary hypertension. Oxygen saturation <90% was found to be independent predictor of perinatal complications (RR = 8.270, 95%CI 1.374-49.790, P = 0.021).

Conclusions

Oxygen saturation <90% is associated with maternal and perinatal risks. Women with TOF whose oxygen saturation <90% are not recommended for pregnancy because of high maternal and perinatal complications.

Anti-IgE therapy inhibits chemotaxis, proliferation and transformation of circulating fibrocytes in patients with severe allergic asthma

BACKGROUND AND OBJECTIVE

Circulating fibrocytes act as precursors of myofibroblasts, contribute to airway remodelling in chronic asthma and migrate to injured tissues by expressing CXCR4 and CCR7. Anti-IgE therapy improves severe allergic asthma (SAA) control and airway remodelling in T2-high SAA. The effects of anti-IgE therapy on fibrocyte activities were investigated in this study.

METHODS

The expression of CCR7, CXCR4, ST2 and α-SMA (α-smooth muscle actin) in both circulating and cultured fibrocytes from all patients with asthma was measured, and was repeated after omalizumab treatment in SAA. Fibrocytes recruitment, proliferation and transformation were also measured in response to anti-IgE therapy.

RESULTS

Omalizumab effectively improved asthma control and pulmonary function in T2-high SAA, associated with a decline in serum levels of IL-33 and IL-13. Omalizumab down-regulates CXCR4 and CCR7 expression of fibrocytes, which could suppress fibrocyte recruitment into the lungs. Omalizumab also suppressed the increased number of fibrocytes and α-SMA⁺ fibrocytes within the cultured non-adherent non-T (NANT) cells after 3-7 days of culture. The decrease in serum levels of IL-33 by omalizumab contributed to the effectiveness in inhibiting fibrocyte recruitment, proliferation and myofibroblast transformation through IL-33/ST2 axis. The elevated IL-13 expression in SAA patients potentiated the effects of IL-33 by increasing ST2 expression.

CONCLUSION

Omalizumab reduced the number of circulating fibrocytes, cell and number of fibrocytes as well as α-SMA⁺ fibrocytes after 3-7 days of culture in SAA patients. IL-33 and IL-13 may be implicated in the effectiveness of omalizumab in inhibiting fibrocyte activation contributing partly to the clinical benefits in reducing lamina propria and basement membrane thickening.

Factors related to hospital-to-home transitional self-monitoring blood glucose behaviour among patients with diabetes-related foot ulcer

AIMS

To explore the factors related to hospital-to-home transitional self-monitoring blood glucose behaviour among patients with diabetes-related foot ulcer.

BACKGROUND

The 30-day readmission rate of patients with diabetes-related foot ulcer can be reduced when good glycaemic control is achieved. The practice of self-monitoring blood glucose promotes optimal glycaemic control.

DESIGN

A comparative descriptive study.

METHODS

In this study, 200 participants, who had been hospitalized due to diabetes-related foot ulcer, were recruited from August 2017 to July 2018. Before participants were discharged from the hospital, psychosocial factors (family support, threat belief, self-efficacy and knowledge) and pre-hospitalization self-monitoring blood glucose behaviour were collected using a structured questionnaire. Then, after discharge, self-monitoring blood glucose behaviour delivery was collected again.

RESULTS

Five variables explained 47% of the variance in the delivery of self-monitoring of blood glucose at home. The delivery of hospital-to-home transitional self-monitoring blood glucose behaviour was more likely for individuals with higher pre-discharge self-efficacy, higher post-discharge self-efficacy, more attention to pre-hospitalization glycaemic status and post-discharge insulin usage and those without an insensitive foot.

CONCLUSION

Self-monitoring blood-glucose behaviour should be promoted among post-discharge patients with diabetes-related foot ulcer. The modifiable factors identified in this study can be integrated into the discharge plan.

Effects of home-based exercise on motor, non-motor symptoms and health-related quality of life in Parkinson's disease patients: A randomized controlled trial

AIM

To explore the effect of home-based exercise on motor symptoms (MS), non-motor symptoms (NMS), and health-related quality of life (HRQOL) in Parkinson's disease (PD) patients.

METHODS

This study was a randomized control trial with a convenience sample of 98 PD patients. Data were collected at baseline and interventions after 4 and 8 weeks. The exercise group was instructed to perform 150 min/week of exercise at home; the control group maintained their regular lifestyle. Questionnaires measured MS, NMS, and HRQOL. We also compare compliance and non-compliance subgroups of the exercise group. The generalized estimating equation (GEE) was used to determine the exercise effect of 120 and 150 min per week after testing for exercise times was at six time points (90-140 min).

RESULTS

The exercise (n = 49) and control groups (n = 49) were homogeneous except for disease stage at baseline. Significant differences were found for depression, HRQOL, motor ability, activity of daily living, and fatigue (p < .000) between the exercise and control groups, and also between the compliance and non-compliance subgroups (p < .05). The GEE revealed that exercising 150 min/week significantly improved HRQOL, depression, motor ability, ADL, fatigue, and sleep quality (p < .05), though not anxiety, and exercising 120 min/week was also effective.

CONCLUSIONS

This home-based exercise was effective in improving MS, NMS, and HRQOL. We recommend PD patients to exercise 30-50 min at least three times a week, or 10-15 min per session daily, to accumulate 120-150 min per week.

Significance of Kynurenine 3-Monooxygenase Expression in Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of cancer-related deaths. Because of the lack of reliable prognostic and predictive biomarkers for CRC, most patients are often diagnosed at a late stage. The tryptophan–kynurenine pathway plays a crucial role in promoting cancer progression. Kynurenine is considered an oncometabolite in colon cancer, and its downstream metabolites are also associated with CRC. Kynurenine 3-monooxygenase (KMO), a pivotal enzyme that catalyzes kynurenine metabolism, is essential for several cellular processes. In the current study, we explored the role of KMO in CRC. Immunohistochemical results showed that KMO was upregulated in CRC tissues relative to paired healthy tissue and polyps. Moreover, CRC patients with higher KMO expression were associated with higher metastasis and poorer survival rates. Knockdown of KMO decreased the expression of cancer stem cell markers, as well as the sphere-forming, migration, and invasion abilities of CRC cells. Additionally, blockade of the enzymatic activity of KMO using an inhibitor suppressed sphere formation and cell motility in CRC cells. These findings suggest the clinical relevance of KMO in CRC tumorigenesis and aggressiveness.

Emergence of a butterfly: the life experiences of type 1 diabetes Taiwanese patients during the 16-25 years old transition period

Purpose: To explore the life experiences of patients with type 1 diabetes transition from adolescence into adulthood in Taiwan.

Methods: Descriptive phenomenological design was used. Fourteen participants were individually interviewed using a semi-structured interview.

Results: The life experiences of patients with type 1 diabetes transition from adolescence into adulthood experience a metamorphosis from awareness of responsibility to figuring out a way to care for themselves. Six themes emerged: (1) hibernation: awareness of responsibility; (2) emergence: attempts to take responsibility; (3) perseverance: encountering difficulties; (4) anxiety: multiple worries; (5) hesitation: back-and-forth,” and (6) exit: finding a way out.”

Conclusions: During the transition phase, the participants experienced the trials of various situations. Regardless of whether they are able to independently bear the responsibilities of self-management, they all hope to turn around the challenges of disease control and take ownership of their disease. Like a butterfly that emerges from a cocoon, they hoped to overcome the dangers of taking flight through trial and error and navigating the world. The results of this study can serve as a reference for clinical care and developing localized intervention strategies targeted to the transition period between adolescence and young adulthood.

Kynurenine 3-monooxygenase upregulates pluripotent genes through β-catenin and promotes triple-negative breast cancer progression

Background

Triple-negative breast cancer (TNBC) is aggressive and has a poor prognosis. Kynurenine 3-monooxygenase (KMO), a crucial kynurenine metabolic enzyme, is involved in inflammation, immune response and tumorigenesis. We aimed to study the role of KMO in TNBC.

Methods

KMO alteration and expression data from public databases were analyzed. KMO expression levels in TNBC samples were analyzed using immunohistochemistry. Knockdown of KMO in TNBC cells was achieved by RNAi and CRISPR/Cas9. KMO functions were examined by MTT, colony-forming, transwell migration/invasion, and mammosphere assays. The molecular events were analyzed by cDNA microarrays, Western blot, quantitative real-time PCR and luciferase reporter assays. Tumor growth and metastasis were detected by orthotopic xenograft and tail vein metastasis mouse models, respectively.

Findings

KMO was amplified and associated with worse survival in breast cancer patients. KMO expression levels were higher in TNBC tumors compared to adjacent normal mammary tissues. In vitro ectopic KMO expression increased cell growth, colony and mammosphere formation, migration, invasion as well as mesenchymal marker expression levels in TNBC cells. In addition, KMO increased pluripotent gene expression levels and promoter activities in vitro. Mechanistically, KMO was associated with β-catenin and prevented β-catenin degradation, thereby enhancing the transcription of pluripotent genes. KMO knockdown suppressed tumor growth and the expression levels of β-catenin, CD44 and Nanog. Furthermore, mutant KMO (known with suppressed enzymatic activity) could still promote TNBC cell migration/invasion. Importantly, mice bearing CRISPR KMO-knockdown TNBC tumors showed decreased lung metastasis and prolonged survival.

Interpretation

KMO regulates pluripotent genes via β-catenin and plays an oncogenic role in TNBC progression.

Definitive chemoradiotherapy for clinical T4b esophageal cancer - Treatment outcomes, failure patterns, and prognostic factors

PURPOSE

The management of cT4b thoracic esophageal cancer (EC) is challenging. The optimal treatment remains unclear, and prospective or large-scale retrospective reports on treatment outcomes are lacking. The present study was conducted to investigate the treatment outcomes, failure patterns, treatment responses, and prognostic factors focusing on cT4b thoracic EC treated by definitive concurrent chemoradiotherapy (dCRT).

METHODS

A retrospective review of cT4b thoracic EC patients treated with curative intent dCRT at our institution between 2009 and 2017 was conducted. Survival analysis was calculated using the Kaplan-Meier method, and prognostic factors were examined by the Cox proportional hazards model.

RESULTS

A total of 95 cT4b EC patients were included, and the median survival was 11.4 months. The 1-year, 3-year, and 5-year survival rates were 49.4%, 22.2%, and 19.0%, respectively. Forty-six patients (48.4%) experienced locoregional failure, 3 patients (3.2%) developed distant metastasis, and 11 patients had synchronous locoregional and distant failure. The corresponding 1-year, 3-year, and 5-year locoregional failure rates were 62.6%, 74.5%, and 79.2%, respectively. The treatment response rate was 76.9%, and clinical complete response was achieved in 25.3% of patients. Multivariable analysis revealed that age ≤ 65 (p = 0.003), pre-dCRT body mass index (BMI) > 21 (p < 0.001), clinical N stage 0-1 (p = 0.014), and tumor length ≤ 6 cm (p = 0.026) were independent prognosticators for better survival.

CONCLUSION

Our study revealed that long-term survival is achievable for cT4b EC patients treated by dCRT, with a 3-year survival rate of more than 20%. Locoregional recurrence was the most common failure pattern. Age, BMI, N stage, and tumor length were significant prognosticators for survival in this group of patients.

Psychometric evaluation of the Farsi version of the diabetes foot self-care bahavior scale

BACKGROUND

Diabetes foot self-care is one of the self-management behaviors of diabetic patients leading to a reduction in the incidence of pressure ulcers and amputation. Having a valid, reliable, simple and comprehensive tool is essential in measuring the self-care behavior of diabetic patients. The aim of this study was to evaluate the psychometric properties of the Farsi version of the diabetes foot self-care bahavior scale (DFSBS) in Iran.

METHODS

In this cross-sectional and methodological study, 500 patients with type 2 diabetes were recruited by convenience sampling. Construct validity was assessed by exploratory factor analysis (over 300 patients) and confirmatory factor analysis (over 200 patients). Internal consistency was calculated by Cronbach's alpha coefficient and its stability was calculated by intraclass correlation coefficient (ICC).

RESULTS

In the exploratory factor analysis, two self-care factors related to feet and shoes were extracted which had specific values of 38.49 and 1.24, respectively, and were able to account for 56.22% of the total self-care variance of diabetes foot. Confirmatory factor analysis had excellent fit model. The internal consistency and ICC of the whole instrument were 0.83 and 0.791 (95% CI: 0.575-0.925; P < 0.001), respectively.

CONCLUSIONS

The Farsi version of DFSBS (F-DFSBS) has good validity and reliability, and due to its appropriate psychometric properties, this tool can be used in future studies.

Targeting the PI3K/mTOR Pathway Augments CHK1 Inhibitor-Induced Replication Stress and Antitumor Activity in High-Grade Serous Ovarian Cancer

High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecologic malignancy in industrialized countries and has limited treatment options. Targeting ataxia-telangiectasia and Rad3-related/cell-cycle checkpoint kinase 1 (CHK1)-mediated S-phase and G₂-M-phase cell-cycle checkpoints has been a promising therapeutic strategy in HGSOC. To improve the efficacy of CHK1 inhibitor (CHK1i), we conducted a high-throughput drug combination screening in HGSOC cells. PI3K/mTOR pathway inhibitors (PI3K/mTORi) showed supra-additive cytotoxicity with CHK1i. Combined treatment with CHK1i and PI3K/mTORi significantly attenuated cell viability and increased DNA damage, chromosomal breaks, and mitotic catastrophe compared with monotherapy. PI3K/mTORi decelerated fork speed by promoting new origin firing via increased CDC45, thus potentiating CHK1i-induced replication stress. PI3K/mTORi also augmented CHK1i-induced DNA damage by attenuating DNA homologous recombination repair activity and RAD51 foci formation. High expression of replication stress markers was associated with poor prognosis in patients with HGSOC. Our findings indicate that combined PI3K/mTORi and CHK1i induces greater cell death in HGSOC cells and in vivo models by causing lethal replication stress and DNA damage. This insight can be translated therapeutically by further developing combinations of PI3K and cell-cycle pathway inhibitors in HGSOC. SIGNIFICANCE: Dual inhibition of CHK1 and PI3K/mTOR pathways yields potent synthetic lethality by causing lethal replication stress and DNA damage in HGSOC, warranting further clinical development.

Abstract 621: Combined inhibition of checkpoint kinase 1 (CHK1) and phosphoinositide 3-kinase (PI3K) pathways induces greater replication stress and DNA damage in high-grade serous ovarian cancer (HGSOC)

HGSOC is characterized by universal TP53 mutations and consequent G1 cell cycle dysfunction, thus relies on ATR/CHK1-mediated G2/M arrest for survival. CHK1 is also necessary for chromosome stability by mitigating replication stress (RS) and promoting homologous recombination (HR) DNA repair following DNA damage. However, clinical responses to CHK1 inhibitor (CHK1i) monotherapy have been variable in HGSOC, requiring new treatment strategies. We thus conducted a high throughput drug combination screening of a CHK1i, prexasertib (Prex) with 1,912 drugs in HGSOC cell lines (BRCA wild-type [BRCAwt: OVCAR5 and OVCAR8] and BRCA2 mutant [BRCA2m: PEO1]). In this screen, 24 drugs showed synergistic cytotoxicity with Prex, including 14 (58%) chemotherapies, 6 (25%) PI3K pathway inhibitors and 4 (17%) targeted drugs. We prioritized the PI3K pathway inhibitors given the PI3K pathway is activated in &gt;45% of HGSOC and associated with increased cell survival, DNA repair and chemo-resistance. We confirmed the combination of Prex and a dual PI3K/mTOR inhibitor LY3023414 (LY302) yielded synergistic cytotoxicity (combination index&lt;1) in a panel of HGSOC cell lines (OVCAR3, OVCAR5, OVCAR8, OV90 and PEO4 [all BRCA-proficient] and PEO1) by XTT and colony formation assays. OVCAR8 and PEO1 were used for further mechanistic studies. With clinically attainable concentrations of Prex (5 nM) and LY302 (200 nM), Prex+LY302 increased caspase 3/7 activation compared to Prex (increased 2,407% and 39%, respectively; P&lt;0.01) or LY302 (increased 2,457% and 57%, respectively; P&lt;0.001) in both cell lines. Prex+LY302 also enhanced the percentage of cells with ≥5 γH2AX foci relative to Prex (increased 39% and 22%, respectively; P&lt; 0.001) or LY302 (increased 48% and 32%, respectively; P&lt;0.001) in both cells, indicating greater DNA damage. We found Prex+LY302 induced a significant HR deficiency as manifested by decreased DR-GFP reporter activity compared to Prex (decreased 37% and 28%, respectively; P&lt;0.01) or LY302 (decreased 44% and 63%, respectively; P&lt;0.01), suggesting Prex+LY302 causes DNA damage likely via reducing HR functionality. Cell cycle analysis showed an imposed S phase arrest in cells treated with Prex+LY302 compared to those treated with Prex (increased 30% and 35%, respectively; P&lt;0.05) or LY302 (increased 38% and 51%, respectively; P&lt;0.01), implying Prex+LY302 increases RS or DNA damage during S phase. Supporting this notion, Prex+LY302 augmented RS as evidenced by increased phospho-RPA+/γH2AX+ populations compared with Prex (increased 37% and 38%, respectively; P&lt;0.05) or LY302 (increased 80% and 79%, respectively; P&lt;0.001). Overall, our results suggest that dual inhibition of CHK1 and PI3K pathways results in greater RS, DNA damage and subsequent cell death in HGSOC cells independent of BRCA mutation status.

Citation Format: Tzu-Ting Huang, Jayakumar Nair, Ethan Brill, Xiaohu Zhang, Kelli Wilson, Lu Chen, Craig J. Thomas, Jung-Min Lee. Combined inhibition of checkpoint kinase 1 (CHK1) and phosphoinositide 3-kinase (PI3K) pathways induces greater replication stress and DNA damage in high-grade serous ovarian cancer (HGSOC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 621.

Resistance to the CHK1 inhibitor prexasertib involves functionally distinct CHK1 activities in BRCA wild-type ovarian cancer

High grade serous ovarian cancer (HGSOC) is a fatal gynecologic malignancy in the U.S. with limited treatment options. New therapeutic strategies include targeting of the cell cycle checkpoints, e.g., ATR and CHK1. We recently reported a promising clinical activity of the CHK1 inhibitor (CHK1i) prexasertib monotherapy in BRCA wild-type (BRCAwt) HGSOC patients. In this study, biopsies of treated patients and cell line models were used to investigate possible mechanisms of resistance to CHK1i. We report that BRCAwt HGSOC develops resistance to prexasertib monotherapy via a prolonged G2 delay induced by lower CDK1/CyclinB1 activity, thus preventing cells from mitotic catastrophe and cell death. On the other hand, we noted CHK1's regulation on RAD51-mediated homologous recombination (HR) repair was not altered in CHK1i-resistant cells. Therefore, CHK1i sensitizes CHK1i-resistant cells to DNA damaging agents such as gemcitabine or hydroxyurea by inhibition of HR. In summary, our results demonstrate new mechanistic insights of functionally distinct CHK1 activities and highlight a potential combination treatment approach to overcome CHK1i resistance in BRCAwt HGSOC.

Proton versus photon radiotherapy for primary hepatocellular carcinoma: a propensity-matched analysis

Background

Proton radiotherapy has a dosimetric advantage over photon radiotherapy. Many retrospective studies have shown promising results with proton radiotherapy in treating hepatocellular carcinoma (HCC). However, clinical evidence demonstrating the benefit of protons over photons is still limited. We therefore compared the clinical outcomes of the two modalities using medical research databases from our medical foundation.

Methods

We conducted a propensity score-matched cohort study based on our multi-institution medical organization research database. From January 2007 to January 2018, a total of 413 patients (photon: 349; proton: 64) who were diagnosed with HCC and primarily treated with radiotherapy with curative intent were enrolled. Overall survival (OS) and radiation-induced liver disease (RILD) were assessed. Stratified analysis was also performed to evaluate the heterogeneous effects of the two arms.

Results

A total of 110 patients (photon: 55; proton: 55) were analyzed in the propensity-matched series. The matched groups were balanced for baseline tumor risk factors. Cox regression analysis revealed a significant survival benefit in the proton group (p = 0.032, HR 0.56, 95% CI 0.33–0.96). The median overall survival in the proton group was not reached and that in the photon group was 17.4 months. The biological equivalent dose of radiotherapy was significantly higher in the proton group than in the photon group (median, 96.56 Gray [relative biological effectiveness] vs. 62.5 Gray, p < 0.001). The risk of RILD was significantly lower in the proton group (11.8% vs. 36%, p = 0.004).

Conclusions

Proton radiotherapy could deliver a higher radiation dose than photon radiotherapy without increasing the risk of RILD and result in a better overall survival rate for those diagnosed with HCC and treated with radiotherapy with curative intent.

Mevalonate Pathway Enzyme HMGCS1 Contributes to Gastric Cancer Progression

The 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) is a potential regulatory node in the mevalonate pathway that is frequently dysregulated in tumors. This study found that HMGCS1 expression is upregulated in stomach adenocarcinoma samples of patients and tumorspheres of gastric cancer cells. HMGCS1 elevates the expression levels of the pluripotency genes Oct4 and SOX-2 and contributes to tumorsphere formation ability in gastric cancer cells. HMGCS1 also promotes in vitro cell growth and progression and the in vivo tumor growth and lung metastasis of gastric cancer cells. After blocking the mevalonate pathway by statin and dipyridamole, HMGCS1 exerts nonmetabolic functions in enhancing gastric cancer progression. Furthermore, the level and nuclear translocation of HMGCS1 in gastric cancer cells are induced by serum deprivation. HMGCS1 binds to and activates Oct4 and SOX-2 promoters. HMGCS1 also enhances the integrated stress response (ISR) and interacts with the endoplasmic reticulum (ER) stress transducer protein kinase RNA-like endoplasmic reticulum kinase (PERK). Our results reveal that HMGCS1 contributes to gastric cancer progression in both metabolic and nonmetabolic manners.

Targeting the PI3K pathway and DNA damage response as a therapeutic strategy in ovarian cancer

Ovarian cancer is the most lethal gynecological malignancy worldwide although exponential progress has been made in its treatment over the last decade. New agents and novel combination treatments are on the horizon. Among many new drugs, a series of PI3K/AKT/mTOR pathway (referred to as the PI3K pathway) inhibitors are under development or already in clinical testing. The PI3K pathway is frequently upregulated in ovarian cancer and activated PI3K signaling contributes to increased cell survival and chemoresistance. However, no significant clinical success has been achieved with the PI3K pathway inhibitor(s) to date, reflecting the complex biology and also highlighting the need for combination treatment strategies. DNA damage repair pathways have been active therapeutic targets in ovarian cancer. Emerging data suggest the PI3K pathway is also involved in DNA replication and genome stability, making DNA damage response (DDR) inhibitors as an attractive combination treatment for PI3K pathway blockades. This review describes an expanded role for the PI3K pathway in the context of DDR and cell cycle regulation. We also present the novel treatment strategies combining PI3K pathway inhibitors with DDR blockades to improve the efficacy of these inhibitors for ovarian cancer.

Generating Third Harmonic Vacuum Ultraviolet Light with a TiO2 Metasurface

Dielectric metasurfaces have recently been shown to provide an excellent platform for the harmonic generation of light due to their low optical absorption and to the strong electromagnetic field enhancement that can be designed into their constituent meta-atoms. Here, we demonstrate vacuum ultraviolet (VUV) third harmonic generation from a specially designed dielectric metasurface consisting of a titanium dioxide (TiO₂) nanostructure array. The metasurface was designed to enhance the generation of VUV light at a wavelength of 185 nm by tailoring its geometric design parameters to achieve an optical resonance at the fundamental laser wavelength of 555 nm. The metasurface exhibits an enhancement factor of nominally 180 compared to an unpatterned TiO₂ thin film of the same thickness, evidence of strong field enhancement at the fundamental wavelength. Mode analysis reveals that the origin of the enhancement is an anapole resonance near the pump wavelength. This work demonstrates an effective strategy for the compact generation of VUV light that could enable expanded access to this useful region of the electromagnetic spectrum.

The impact of a medication reconciliation programme at geriatric hospital admission: A pre-/postintervention study

AIMS

The aim of this study was to improve medication reconciliation and reduce the occurrence of duplicate prescriptions by pharmacists and physicians within 72 hours of hospital admission using an intelligent prescription system combined with the National Health Insurance PharmaCloud system to integrate the database with the medical institution computerized physician order entry (CPOE) system.

METHODS

This 2-year intervention study was implemented in the geriatric ward of a hospital in Taiwan. We developed an integrated CPOE system linked with the PharmaCloud database and established an electronic platform for coordinated communication with all healthcare professionals. Patients provided written informed consent to access their PharmaCloud records. We compared the intervention effectiveness within 72 hours of admission for improvement in pharmacist medication reconciliation, increased at-home medications documentation and decreased costs from duplicated at-home prescriptions.

RESULTS

The medication reconciliation rate within 72 hours of admission increased from 44.0% preintervention to 86.8% postintervention (relative risk = 1.97, 95% confidence interval [CI]: 1.69-2.31; P < .001). The monthly average of patients who brought and took home medications documented in the CPOE system during hospitalization increased by 7.54 (95% CI 5.58-20.49, P = .22). The monthly average of home medications documented increased by 102.52 (95% CI 38.44-166.60; P = .01). Savings on the monthly average prescription expenditures of at-home medication increased by US$ 2,795.52 (95% CI US$1310.41-4280.63; P < .01).

CONCLUSION

Integrating medication data from PharmaCloud to the hospital's medical chart system improved pharmacist medication reconciliation, which decreased duplicated medications and reduced in-hospital medication costs.

Surface Micro-/Nanotextured Hybrid PEDOT:PSS-Silicon Photovoltaic Cells Employing Kirigami Graphene

Kirigami graphene allows a two-dimensional material to transform into a three-dimensional structure, which constitutes an effective transparent electrode candidate for photovoltaic (PV) cells having a surface texture. The surface texture of an inverted pyramid was fabricated on a Si substrate using photolithography and wet etching, followed by metal-assisted chemical etching to obtain silicon nanowires on the surface of the inverted pyramid. Kirigami graphene with a cross-pattern array was prepared using photolithography and plasma etching on a copper foil. Then, kirigami graphene was transferred onto hybrid heterojunction PV cells with a poly(ethylene terephthalate)/silicone film. These cells consisted of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as the p-type semiconductor, Si(100) as the inorganic n-type semiconductor, and a silver comb electrode on top of PEDOT:PSS. The conductivity of PEDOT:PSS was greatly improved. This improvement was significantly higher than that achieved by the continuous graphene sheet without a pattern. Transmission electron microscopy and Raman spectroscopy results revealed that the greater improvement with kirigami graphene was due to the larger contact area between PEDOT:PSS and graphene. By using two-layer graphene having a kirigami pattern, the power conversion efficiency, under simulated AM1.5G illumination conditions, was significantly augmented by up to 9.8% (from 10.03 to 11.01%).

Abstract 1711: Kynurenine 3-monooxygenase (KMO) acts as a novel oncoprotein in triple negative breast cancer

Purpose: Tryptophan-kynurenine pathway involves in inflammation, immune response and tumorigenesis, in which kynurenine 3-monooxygenase (KMO), an outer mitochondrial membrane protein, mediating kynurenine metabolism. Previous studies indicated KMO showed increased activity in breast cancer. Triple-negative breast cancer (TNBC) tumors exhibited elevated levels of tryptophan metabolites compared to estrogen receptor positive breast cancers. We aimed to study the role of KMO in human TNBC.

Experimental design: The gene alterations and transcripts of enzymes in kynurenine metabolism were analyzed from The Cancer Genome Atlas (TCGA) database. Immunohistochemical staining for KMO was performed and a H-score was assigned to quantify protein expression. Epithelial-mesenchymal transition (EMT) phenotypes were examined by transwell assay and EMT markers expressions. Stemness properties were assessed by mammosphere assay and pluripotent genes expressions. The molecular events were analyzed by Western blot, quantitative real-time PCR and luciferase reporter assay. Tumor growth and metastasis were conducted in nude mice and NOD-SCID mice by subcutaneous and tail vein injection respectively.

Results: TCGA databases showed KMO but not KYNU and KAT2 was amplified in breast cancer. Both the data from TCGA and our in-house IHC-based tissue-microarray exhibited increased KMO expression in TNBC compared to normal tissue. In vitro, overexpression of KMO in TNBC cells resulted in increased cell growth and colony formation. The abilities migration and invasion as well as EMT markers expressions of TNBC cells were elevated by KMO overexpression. In addition, KMO increased mammosphere formation, pluripotent genes expressions and promoter activities. However, inhibition of KMO enzymatic activity by KMO inhibitors did not affect cancer progression or mitochondrial respiration of TNBC cells. KMO upregulated β-catenin, the upstream regulator of pluripotent genes, CD44 and Nanog expressions. Mechanistically, data showed KMO expressed in both cytosol and nuclear fractions and was associated with β-catenin. KMO enhanced pluripotent genes expressions through β-catenin upregulation. Importantly, KMO knockdown suppressed tumor growth and expressions of β-catenin, CD44 and Nanog in TNBC tumors. Moreover, KMO knockout significantly decreased lung metastasis in vivo.

Conclusion: Our data indicated KMO can play an oncogenic role in TNBC, acting as a novel regulator of pluripotent genes via β-catenin and promoted TNBC progression.

Citation Format: Chun-Yu Liu, Tzu-Ting Huang, Ji-Lin Chen, Chia-Han Lee, Wan-Lun Wang, Ka-Yi Lau, Chun-Teng Huang, Pei-Yi Chu, Hsin-Chen Lee, Ling-Ming Tseng. Kynurenine 3-monooxygenase (KMO) acts as a novel oncoprotein in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1711.

Effect of an Oral Health Programme on Oral Health, Oral Intake, and Nutrition in Patients with Stroke and Dysphagia in Taiwan: A Randomised Controlled Trial

No previous studies have evaluated an oral health programme, before swallowing therapy, in patients with stroke and dysphagia in Taiwan. This randomised controlled trial evaluated the effect of an oral health programme (i.e., sputum assessment, Bass method-based tooth brushing, and tooth coating with fluoride toothpaste) before swallowing therapy. Sixty-six patients with stroke (23 female, 43 male) in our rehabilitation ward, who underwent nasogastric tube insertion, were assigned randomly to an oral care group (n = 33) and a control group (n = 33). Demographic data, oral health assessment, Functional Oral Intake Scale (FOIS) scores, Mini-Nutritional Assessment-Short Form (MNA-SF) scores, and nasogastric tube removal rates were compared between groups. We evaluated outcomes using generalised estimating equation analysis. Three weeks post-implementation, the oral care group had significant oral health improvements relative to the control group (95% CI =−2.69 to −1.25, Wald χ² = 29.02, p < 0.001). There was no difference in the FOIS (95% CI = −0.16 to 0.89, Wald χ² = 1.86, p > 0.05), MNA-SF (95% CI =−0.35 to 0.53, Wald χ² =−0.17, p > 0.05), and nasogastric tube removal (p > 0.05) between groups. The oral care group had a higher, but non-significant FOIS score (3.94 vs 3.52) (p > 0.05). Routine oral health programmes implemented during stroke rehabilitation in patients with dysphagia may promote oral health and maintain oral intake.

Prognostic value of a new clinical-genomic model to predict 10-year risk of recurrence in patients with operable breast cancer

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Background: Searching for a specific biomarker to predict long-term risk of recurrence for all breast cancer subtypes is challenging. DGM-CM6 (Distant Genetic Model-Clinical variable Model 6) is a new clinical-genomic prognostic model developed from the 18-gene panel which was reported previously. This study aims to validate the long-term prognostic value of this new model in all subtypes of operable breast cancer patients. Methods: We included 752 operable breast cancer patients with stage I-III in all subtypes treated in a Cancer Center from 2005 to 2014 as the internal validation (IV) cohort. The median follow-up was 94.1 months. Meanwhile, Affymetrix U133P2 (n = 1139) data obtained from GEO (GSE9195/16391/17907/19615/20711/21653/42568, EMTAB365) were collected as the external validation (EV) dataset. The prognostic effect of DGM-CM6 was then evaluated by uni- and multivariate analyses. The low- and high-risk patients ( < 33 or ≥ 33 as cut-off value) classified by DGM-CM6 were evaluated by the 10-year distant relapse-free interval (DRFI), relapse-free interval (RFI), relapse-free survival (RFS) and distant relapse-free survival (DRFS), respectively. We further compared the predictive performance between DGM-CM6/DGM and PAM50-ROR score in our IV dataset. Results: In the IV dataset, DGM-CM6 was proved to be an independent prognostic factor by multivariate analysis with hazard ratios of 3.1 (1.6-6.0) for RFS (P = 0.0009) and 3.2 (1.6-6.3) for DRFS (P = 0.0009). Significant differences were observed between low- and high-risk groups with 10-year RFI (94.0% vs. 83.5%, P < 0.0001), RFS (90.0% vs. 80.5%, P = 0.0003), DRFI (94.1% vs. 85.0%, P < 0.0001), and DRFS (90.1% vs. 81.9%, P = 0.0004), respectively. The prognostic value of RFS was convinced in the EV dataset (HR = 1.34, P = 0.00052) by the DGM only. According to C-index estimate analysis, DGM appeared to have better performance comparing with PAM50 ROR score in prediction of long-term DR, DRFS, RFI, and RFS in N0 patients (C index for distant recurrence: 0.582 by DGM, 0.528 by ROR). Conclusions: DGM-CM6 could be a new long-term prognostic model to be applied in all subtypes of operable breast cancer patients. Further validation in a large scale of clinical trials is needed.

Factors associated with foot ulcer self-management behaviours among hospitalised patients with diabetes

AIMS AND OBJECTIVES

To determine prehospitalised diabetes-related foot ulcer (DFU) self-management behaviours and explore the factors associated with these behaviours.

BACKGROUND

Although there are many studies that explore DFU prevention and treatment, to our knowledge, there are no quantitative studies of DFU self-management behaviours.

DESIGN

Cross-sectional design.

METHODS

From June 2015-June 2016, 199 hospitalised patients with DFU were given a survey questionnaire at a medical centre in northern Taiwan. DFU self-management behaviours, diabetes foot self-care behaviours, beliefs in regard to barriers to DFU self-management behaviours, and knowledge regarding warning signs of DFU deterioration were assessed by well-designed measurement tools. The Strengthening the Reporting of Observational Studies in Epidemiology checklist was used to ensure quality reporting during this observational study (see Supporting Information Appendix S1).

RESULTS

The results revealed that 62.8% of participants never monitored their blood glucose level when they had foot ulcers, and 63.8% never sought treatment for their wounds when their wounds were not painful. After controlling for demographic and medical variables, stepwise multiple regression analysis revealed that the following eight significant variables were associated with DFU self-management behaviours: two DFU self-management barrier beliefs, foot self-care behaviour, no treatment for diabetes, poor financial status, employment, knowledge regarding the warning signs of DFU deterioration, and number of DFU hospitalisations.

CONCLUSIONS

Diabetes-related foot ulcer self-management behaviours were insufficient. Some modifiable factors and high-risk groups for insufficient DFU self-management behaviour were identified.

RELEVANCE TO CLINICAL PRACTICE

Diabetes-related foot ulcer self-management behaviours should be promoted. Interventions that modify the risk factors that were identified in this study can be designed to promote the performance of DFU self-management behaviours.