Comprehensive analysis on clinical significance and therapeutic targets of LDL receptor related protein 11 (LRP11) in liver hepatocellular carcinoma

LDL lipoprotein receptor-related protein 11 (LRP11) plays a role in several tumors. However, their roles in hepatocellular carcinoma remain unclear. The present study aimed to explore the expression profile and prognostic value of LRP11 in liver hepatocellular carcinoma (LIHC) patients using various cancer databases and bioinformatic tools. In bioinformatics analysis, The Cancer Genome Atlas datasets showed increased LRP11 expression in tumor tissues compared to that in non-tumor tissues in various cancers. Moreover, patients with high expression LRP11 correlated with poor prognosis and clinical features. The LRP11 expression positively correlated with the infiltration of immune cells such as macrophages, neutrophils, and myeloid-derived suppressor cells and a combination of high LRP11 expression and high immune infiltrates was associated with the worst survival in LIHC tumors. Our results also indicated that LRP11 expression was closely associated with immune-modulate function, such as antigen presentation. In DNA methylation profiling, hypomethylation of LRP11 is widely observed in tumors and has prognostic value in LIHC patients. Functional enrichment analysis revealed that LIHC-specific LRP11 interacting genes are involved in protein binding, intracellular processing, and G-protein-related signaling pathways. Analyses of drug sensitivity and immune checkpoint inhibitor predict a number of drugs that could potentially be used to target LRP11. In addition, in vitro experiments verified the promoting effect of LRP11 on the migration, invasion, and colony formation capacity of hepatocellular carcinoma cells. Collectively, our results aided a better understanding of the clinical significance of LRP11 in gene expression, functional interactions, and epigenetic regulation in LIHC and suggested that it may be a useful prognostic biomarker for LIHC patients.

Overcoming adaptive resistance to anti-VEGF therapy by targeting CD5L

Antiangiogenic treatment targeting the vascular endothelial growth factor (VEGF) pathway is a powerful tool to combat tumor growth and progression; however, drug resistance frequently emerges. We identify CD5L (CD5 antigen-like precursor) as an important gene upregulated in response to antiangiogenic therapy leading to the emergence of adaptive resistance. By using both an RNA-aptamer and a monoclonal antibody targeting CD5L, we are able to abate the pro-angiogenic effects of CD5L overexpression in both in vitro and in vivo settings. In addition, we find that increased expression of vascular CD5L in cancer patients is associated with bevacizumab resistance and worse overall survival. These findings implicate CD5L as an important factor in adaptive resistance to antiangiogenic therapy and suggest that modalities to target CD5L have potentially important clinical utility.

Differences in Function and Healthcare Cost of Older Adults with Dementia by Long-Term Care Service Type: A National Dataset Analysis

This study aims to analyze the function and cost changes among long-term care insurance (LTCI) beneficiaries with low-severity dementia according to their LTCI service type. Data were collected from the Korean LTCI and national health insurance (NHI) datasets. Participants were 4414 beneficiaries with dementia aged 65 or older who received LTC services continuously for 4 years (2008–2011). LTCI service types were classified into home care (HC), institutional care (IC), and combined care (CC). Activities of daily living (ADL), cognitive function, medical cost, and benefit-cost were assessed. Linear mixed models and multiple regression models were used to analyze the changes in function and costs of the beneficiaries. ADL, cognitive function, medical cost, and benefit-cost differed significantly depending on the service type and time (p < 0.001). LTCI service types affected the degree of changes in ADL, cognitive function, medical cost, and benefit-cost over four years and showed negative changes in IC and CC beneficiaries than HC beneficiaries. HC is a cost-effective way to maintain the function of beneficiaries with low-severity dementia. Thus, efforts are needed to actively promote HC services.

PRKRA/PACT Expression Promotes Chemoresistance of Mucinous Ovarian Cancer

For mucinous ovarian cancer (MOC), standard platinum-based therapy is largely ineffective. We sought to identify possible mechanisms of oxaliplatin resistance of MOC and develop strategies to overcome this resistance. A kinome-based siRNA library screen was carried out using human MOC cells to identify novel targets to enhance the efficacy of chemotherapy. In vitro and in vivo validations of antitumor effects were performed using mouse MOC models. Specifically, the role of PRKRA/PACT in oxaliplatin resistance was interrogated. We focused on PRKRA, a known activator of PKR kinase, and its encoded protein PACT because it was one of the five most significantly downregulated genes in the siRNA screen. In orthotopic mouse models of MOC, we observed a significant antitumor effect of PRKRA siRNA plus oxaliplatin. In addition, expression of miR-515-3p was regulated by PACT-Dicer interaction, and miR-515-3p increased the sensitivity of MOC to oxaliplatin. Mechanistically, miR-515-3p regulated chemosensitivity, in part, by targeting AXL. The PRKRA/PACT axis represents an important therapeutic target in MOC to enhance sensitivity to oxaliplatin.

Induction of anti-VEGF therapy resistance by upregulated expression of microseminoprotein (MSMP)

Anti-vascular endothelial growth factor (VEGF) therapy has demonstrated efficacy in treating human metastatic cancers, but therapeutic resistance is a practical limitation and most tumors eventually become unresponsive. To identify microenvironmental factors underlying the resistance of cancer to antiangiogenesis therapy, we conducted genomic analyses of intraperitoneal ovarian tumors in which adaptive resistance to anti-VEGF therapy (B20 antibody) developed. We found that expression of the microseminoprotein, prostate-associated (MSMP) gene was substantially upregulated in resistant compared with control tumors. MSMP secretion from cancer cells was induced by hypoxia, triggering MAPK signaling in endothelial cells to promote tube formation in vitro. Recruitment of the transcriptional repressor CCCTC-binding factor (CTCF) to the MSMP enhancer region was decreased by histone acetylation under hypoxic conditions in cancer cells. MSMP siRNA, delivered in vivo using the DOPC nanoliposomes, restored tumor sensitivity to anti-VEGF therapy. In ovarian cancer patients treated with bevacizumab, serum MSMP concentration increased significantly only in non-responders. These findings imply that MSMP inhibition combined with the use of antiangiogenesis drugs may be a new strategy to overcome resistance to antiangiogenesis therapy.

Inhibiting Nuclear Phospho-Progesterone Receptor Enhances Antitumor Activity of Onapristone in Uterine Cancer

Although progesterone receptor (PR)-targeted therapies are modestly active in patients with uterine cancer, their underlying molecular mechanisms are not well understood. The clinical use of such therapies is limited because of the lack of biomarkers that predict response to PR agonists (progestins) or PR antagonists (onapristone). Thus, understanding the underlying molecular mechanisms of action will provide an advance in developing novel combination therapies for cancer patients. Nuclear translocation of PR has been reported to be ligand-dependent or -independent. Here, we identified that onapristone, a PR antagonist, inhibited nuclear translocation of ligand-dependent or -independent (EGF) phospho-PR (S294), whereas trametinib inhibited nuclear translocation of EGF-induced phospho-PR (S294). Using orthotopic mouse models of uterine cancer, we demonstrated that the combination of onapristone and trametinib results in superior antitumor effects in uterine cancer models compared with either monotherapy. These synergistic effects are, in part, mediated through inhibiting the nuclear translocation of EGF-induced PR phosphorylation in uterine cancer cells. Targeting MAPK-dependent PR activation with onapristone and trametinib significantly inhibited tumor growth in preclinical uterine cancer models and is worthy of further clinical investigation. Mol Cancer Ther; 17(2); 464-73. ©2017 AACR.

Differential Effects of EGFL6 on Tumor versus Wound Angiogenesis

Angiogenesis inhibitors are important for cancer therapy, but clinically approved anti-angiogenic agents have shown only modest efficacy and can compromise wound healing. This necessitates the development of novel anti-angiogenesis therapies. Here, we show significantly increased EGFL6 expression in tumor versus wound or normal endothelial cells. Using a series of in vitro and in vivo studies with orthotopic and genetically engineered mouse models, we demonstrate the mechanisms by which EGFL6 stimulates tumor angiogenesis. In contrast to its antagonistic effects on tumor angiogenesis, EGFL6 blockage did not affect normal wound healing. These findings have significant implications for development of anti-angiogenesis therapies.

Abstract 473: PRKRA/PACT expression promotes chemoresistance in mucinous ovarian cancer

Purpose: To investigate the mechanisms of chemotherapy resistance and developing strategies to enhance therapeutic responses in mucinous ovarian cancer (MOC).

Experimental design: We carried out a kinome-based siRNA screen using human MOC to identify novel targets to enhance the efficacy of chemotherapy in MOC cell lines. In vitro and in vivo validation studies were carried out using MOC models. We specifically interrogated the role of PRKRA in MOC based on our screen results.

Results: Among the 939 genes in the screen, we focused on PRKRA/PACT because it was one of the top 5 target genes that exhibited the greatest extent of synthetic lethality in the target gene-siRNA plus oxaliplatin group relative to the target gene-siRNA group. The combination of oxaliplatin plus siPRKRA treatment resulted in significantly reduced cell viability compared with oxaliplatin plus control siRNA in RMUG-L-ip1 or RMUG-S-ip1 MOC cells (p&lt;0.001), while knockdown of PRKRA did not result in a significant change in cell viability compared with the control. We also observed a 2.1-fold increase in cell apoptosis in vitro after treatment with oxaliplatin plus siPRKRA in both MOC cells (p&lt;0.05). Using orthotopic mouse models of MOC, we observed an 88% reduction (p&lt;0.01) in tumor weight and 75% reduction in the number of tumor nodules (p&lt;0.01) in the siPRKRA plus oxaliplatin group compared with the control siRNA plus oxaliplatin group. PRKRA expression in human MOC was significantly higher relative to high-grade serous ovarian tumors as evaluated by immunohistochemistry. Furthermore, we found that the interaction between PACT and Dicer can regulate maturation of microRNA. In particular, mature-miR-515-3p was found to be inhibited by the interaction between PACT and Dicer. Expression of miR-515-3p promotes chemosensitivity in MOC by targeting the mRNA of the anti-apoptotic gene AXL.

Conclusion: The PRKRA/PACT axis represents an important therapeutic opportunity in MOC for enhancing oxaliplatin efficacy.

Citation Format: Takeshi Hisamatsu, Michael McGuire, Sherry Y. Wu, Rajesha Rupaimoole, Sunila Pradeep, Kyunghee Noh, Justyna Filant, Jean M. Hansen, Yasmin Lyons, Kshipra M. Gharpure, Archana S. Nagaraja, Lingegowda S. Mangala, Takashi Mitamura, Cristian Rodriguez-Aguayo, Geoffrey A. Bartholomeusz, Cristina Ivan, Ju-Seong Lee, Koji Matsuo, Michael Frumovitz, Kwong K. Wong, Gabriel Lopez-Berestein, Anil K. Sood. PRKRA/PACT expression promotes chemoresistance in mucinous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 473. doi:10.1158/1538-7445.AM2017-473

Role of YAP1 as a Marker of Sensitivity to Dual AKT and P70S6K Inhibition in Ovarian and Uterine Malignancies

Background

The PI3K/AKT/P70S6K pathway is an attractive therapeutic target in ovarian and uterine malignancies because of its high rate of deregulation and key roles in tumor growth. Here, we examined the biological effects of MSC2363318A, which is a novel inhibitor of AKT1, AKT3, and P70S6K.

Methods

Orthotopic murine models of ovarian and uterine cancer were utilized to study the effect of MSC2363318A on survival and regression. For each cell line, 10 mice were treated in each of the experimental arms tested. Moreover, in vitro experiments in 21 cell lines (MTT, immunoblot analysis, plasmid transfection, reverse phase protein array [RPPA]) were carried out to characterize underlying mechanisms and potential biomarkers of response. All statistical tests were two-sided.

Results

MSC2363318A decreased tumor growth and metastases in multiple murine orthotopic models of ovarian (SKOV3ip1, HeyA8, and Igrov1) and uterine (Hec1a) cancer by reducing proliferation and angiogenesis and increasing cell death. Statistically significant prolonged overall survival was achieved with combination MSC2363318A and paclitaxel in the SKUT2 (endometrioid) uterine cancer mouse model ( P <  .001). Mice treated with combination MSC2363318A and paclitaxel had the longest overall survival (mean = 104.2 days, 95% confidence interval [CI] = 97.0 to 111.4) compared with those treated with vehicle (mean = 61.9 days, 95% CI = 46.3 to 77.5), MSC2363318A alone (mean = 89.7 days, 95% CI = 83.0 to 96.4), and paclitaxel alone (mean = 73.6 days, 95% CI = 53.4 to 93.8). Regression and stabilization of established tumors in the Ishikawa (endometrioid) uterine cancer model was observed in mice treated with combination MSC2363318A and paclitaxel. Synergy between MSC2363318A and paclitaxel was observed in vitro in cell lines that had an IC50 of 5 µM or greater. RPPA results identified YAP1 as a candidate marker to predict cell lines that were most sensitive to MSC2363318A (R = 0.54, P =  .02). After establishment of a murine ovarian cancer model of adaptive anti-angiogenic resistance (SKOV3ip1-luciferase), we demonstrate that resensitization to bevacizumab occurs with the addition of MSC2363318A, resulting in improved overall survival ( P =  .01) using the Kaplan-Meier method. Mice treated with bevacizumab induction followed by MSC2363318A had the longest overall survival (mean = 66.0 days, 95% CI = 53.9 to 78.1) compared with mice treated with control (mean = 42.0 days, 95% CI = 31.4 to 52.6) and bevacizumab-sensitive mice (mean = 47.2 days; 95% CI = 37.5 to 56.9).

Conclusions

MSC2363318A has therapeutic efficacy in multiple preclinical models of ovarian and uterine cancer. These findings support clinical development of a dual AKT/P70S6K inhibitor.

Complement Component 3 Is Regulated by TWIST1 and Mediates Epithelial-Mesenchymal Transition

We have previously shown that complement component 3 (C3) is secreted by malignant epithelial cells. To understand the mechanism of upregulation of C3 expression in tumor cells, we studied the C3 promoter and identified that twist basic helix-loop-helix transcription factor 1 (TWIST1) binds to the C3 promoter and enhances its expression. Because TWIST1 mediates epithelial-mesenchymal transition (EMT), we studied the effect of C3 on EMT and found that C3 decreased E-cadherin expression on cancer cells and promoted EMT. We showed that C3-induced reduction in E-cadherin expression in ovarian cancer cells was mediated by C3a and is Krüppel-like factor 5 dependent. We investigated the association between TWIST1 and C3 in malignant tumors and in murine embryos. TWIST1 and C3 colocalized at the invasive tumor edges, and in the neural crest and limb buds of mouse embryos. Our results identified TWIST1 as a transcription factor that regulates C3 expression during pathologic and physiologic EMT.

Erythropoietin Stimulates Tumor Growth via EphB4

While recombinant human erythropoietin (rhEpo) has been widely used to treat anemia in cancer patients, concerns about its adverse effects on patient survival have emerged. A lack of correlation between expression of the canonical EpoR and rhEpo's effects on cancer cells prompted us to consider the existence of an alternative Epo receptor. Here, we identified EphB4 as an Epo receptor that triggers downstream signaling via STAT3 and promotes rhEpo-induced tumor growth and progression. In human ovarian and breast cancer samples, expression of EphB4 rather than the canonical EpoR correlated with decreased disease-specific survival in rhEpo-treated patients. These results identify EphB4 as a critical mediator of erythropoietin-induced tumor progression and further provide clinically significant dimension to the biology of erythropoietin.

Deferoxamine promotes osteoblastic differentiation in human periodontal ligament cells via the nuclear factor erythroid 2-related factor-mediated antioxidant signaling pathway

BACKGROUND AND OBJECTIVE

Recently it was reported that deferoxamine (DFO), an iron chelator, stimulates bone formation from MG63 and mesenchymal stem cells, but inhibits differentiation in rat calvarial cells; however, the effect of DFO on osteoblastic differentiation in human periodontal ligament cells (hPDLCs) has not been reported. The aim of this study was to investigate the effects and the possible underlying mechanism of DFO on osteoblastic differentiation of hPDLCs.

MATERIAL AND METHODS

The effect of DFO on osteoblast differentiation was determined by the staining intensity of calcium deposits with Alizarin red and by RT-PCR analysis of the expression of osteoblastic markers. Signal transduction pathways were analyzed by western blotting.

RESULTS

DFO increased osteogenic differentiation in a concentration-dependent manner by expression of the mRNA for differentiation markers and calcium nodule formation. Exposure of hPDLCs to DFO resulted in increases in the production of reactive oxygen species and in the levels of nuclear factor erythroid 2-related factor (Nrf2) protein in nuclear extractions, as well as a dose-dependent increase in the expression of Nrf2 target genes, including glutathione (GSH), glutathione S-transferase, γ-glutamylcysteine lygase, glutathione reductase and glutathione peroxidase. Pretreatment with Nrf2 small interfering RNA, GSH depletion by buthionine sulfoximine and diethyl maleate, and with antioxidants by N-acetylcysteine and vitamin E, blocked DFO-stimulated osteoblastic differentiation. Furthermore, pretreatment with GSH depletion and antioxidants blocked DFO-induced p38 MAPK, ERK, JNK and nuclear factor-kappaB pathways.

CONCLUSION

These data indicate, for the first time, that nontoxic DFO promotes osteoblastic differentiation of hPDLCs via modulation of the Nrf2-mediated antioxidant pathway.

Myocardial pharmacokinetics of ebastine, a substrate for cytochrome P450 2J, in rat isolated heart

BACKGROUND AND PURPOSE

It is well established that cytochrome P450 2J (CYP2J) enzymes are expressed preferentially in the heart, and that ebastine is a substrate for CYP2J, but it is not known whether ebastine is metabolized in myocardium. Therefore, we investigated its pharmacokinetics in the rat isolated perfused heart.

EXPERIMENTAL APPROACH

Rat isolated hearts were perfused in the recirculating mode with ebastine for 130 min. The concentrations of ebastine and its metabolites, hydroxyebastine and carebastine, were measured using liquid chromatography with a tandem mass spectrometry. The data were analysed by a compartmental model. The time course of negative inotropic response was linked to ebastine concentration to determine the concentration-effect relationship.

KEY RESULTS

Ebastine was metabolized to an intermediate compound, hydroxyebastine, which was subsequently further metabolized to carebastine. No desalkylebastine was found. The kinetics of the sequential metabolism of ebastine was well described by the compartmental model. The EC(50) of the negative inotropic effect of ebastine in rat isolated heart was much higher than free plasma concentrations in humans after clinical doses.

CONCLUSIONS AND IMPLICATIONS

The kinetics of ebastine conversion to carebastine via hydroxyebastine resembled that observed in human liver microsomes. The results may be of interest for functional characterization of CYP2J activity in rat heart.

The role of surveillance endoscopy and endosonography after endoscopic ablation of high-grade dysplasia and carcinoma of the esophagus

Barrett's esophagus (BE) with high-grade dysplasia (HGD) or early carcinoma treated with surgery or photodynamic therapy (PDT) is at risk of recurrence. The efficacy of endoscopic ultrasound (EUS) for surveillance after PDT is unknown. Our objective was to determine if EUS is superior to esophagogastroduodenoscopy (EGD) and/or CT scan for surveillance of BE neoplasia after PDT. The study was designed as a retrospective review with the setting as a tertiary referral center. Consecutive patients with BE with HGD or carcinoma in situ treated with PDT were followed with EUS, CT scan and EGD with jumbo biopsies every 1 cm at 3, 4, or 6-month intervals. Exclusion criteria was < 6 months of follow up and/or < 2 EUS procedures. Main outcome measurements were residual or recurrent disease discovered by any method. Results showed that 67/97 patients met the inclusion criteria (56 men and 11 women). Median follow-up was 16 months. Recurrent or residual adenocarcinoma (ACA) was detected in four patients during follow-up. EGD with random biopsies or targeted nodule biopsies detected three patients. EUS with endoscopic mucosal resection of the nodule confirmed T1 recurrence in one of these three. In the fourth patient, CT scan revealed perigastric lymphadenopathy and EUS-FNA (fine needle aspiration) confirmed adenocarcinoma. There were two deaths, one related to disease progression and one unrelated. The rate of recurrent/persistent ACA after PDT was 4/67 = 6%. EUS did not detect disease when EGD and CT were normal. Limitations of this study include non-blinding of results and preferential status of non-invasive imaging (CT) over EUS. Our experience suggests that EUS has little role in the surveillance of these patients, unless discrete abnormalities are found on EGD or cross-sectional imaging.

Effect of manufacturing conditions on the formation of double-walled polymer microspheres

This paper discusses the optimization of the solvent evaporation process to produce double-walled (DW) microspheres in a single-step. Five process variables were studied: polymer solution concentration, polymer weight ratio, polymer solution volume ratios, encapsulation temperature, and air flow rate across the top of the encapsulation vessel. The effects of these variables on the process efficiency (defined here as the percentage of microspheres with a DW configuration compared to the total number of microspheres) were examined. Total polymer concentrations of less than 20% (w/v) produced microspheres with high efficiency, with phase separation consistent across all size fractions in each batch. Changing the volume ratio of the two polymer solutions had no significant effect on the process efficiency. The weight ratio of the polymers greatly influenced the process efficiency, resulting in a low 63% efficiency for the 1:3 Poly-L-lactide (PLLA): Poly(carboxyphenoxypropane-co-sebacic)anhydride 20:80 (P(CPP:SA 20:80)) weight ratio and 0% for the 3:1 weight ratio. The 1:3 weight ratio also caused the polymers to reverse their orientation, although the efficiency for this switch was still relatively low. The temperature of the non-solvent bath affected the efficiency of certain pairs of polymers, but not all. The PLLA/Poly(lactide-co-glycolide) 50:50 (PLGA) pair was most sensitive to temperature, due to the chemical similarity of the two polymers which narrowed the range of acceptable conditions for encapsulation. Pairs of polymers which phase separated readily (e.g. polystyrene and PLLA) were the least sensitive to temperature changes. Process yield and size distribution show no clear trends with respect to air flow rate across the top of the reaction vessel. The efficiency of the process to produce DW microspheres increased and the process time decreased with increasing air flow across the surface of the encapsulation vessel.