New retinoblastoma (RB) drug delivery approaches: anti-tumor effect of atrial natriuretic peptide (ANP)-conjugated hyaluronic-acid-coated gold nanoparticles for intraocular treatment of chemoresistant RB

Intraocular drug delivery is a promising approach for treatment of ocular diseases. Chemotherapeutic drugs used in retinoblastoma (RB) treatment often lead to side effects and drug resistances. Therefore, new adjuvant therapies are needed to treat chemoresistant RBs. Biocompatible gold nanoparticles (GNPs) have unique antiangiogenic properties and can inhibit cancer progression. The combination of gold and low-molecular-weight hyaluronan (HA) enhances the stability of GNPs and promotes the distribution across ocular barriers. Attached to HA-GNPs, the atrial natriuretic peptide (ANP), which diminishes neovascularization in the eye, is a promising new therapeutic agent for RB treatment. In the study presented, we established ANP-coupled HA-GNPs and investigated their effect on the tumor formation potential of chemoresistant RB cells in an in ovo chicken chorioallantoic membrane model and an orthotopic in vivo RB rat eye model. Treatment of etoposide-resistant RB cells with ANP-HA-GNPs in ovo resulted in significantly reduced tumor growth and angiogenesis compared with controls. The antitumorigenic effect could be verified in the rat eye model, including a noninvasive application form via eye drops. Our data suggest that ANP-HA-GNPs represent a new minimally invasive, adjuvant treatment option for RB.

Association between glomerular filtration rate and plasma N-terminal pro-atrial natriuretic peptide concentration in dogs

OBJECTIVES

To investigate the association between plasma N-terminal pro-atrial natriuretic peptide concentration and glomerular filtration rate in dogs.

MATERIALS AND METHODS

Dogs were classified into four categories by bodyweight. Dogs were divided into four groups (Groups 1 to 4) based on glomerular filtration rate estimates using plasma iohexol clearance per bodyweight category. Generalised linear models were built to explore the relationship between plasma N-terminal pro-atrial natriuretic peptide concentration and glomerular filtration rate and the effect of confounders on plasma N-terminal pro-atrial natriuretic peptide concentration.

RESULTS

Fifty-three dogs were included (Group 1, 25; Group 2, seven; Group 3, five; and Group 4, 16). The medians (interquartile range) N-terminal pro-atrial natriuretic peptide concentrations for Groups 1 to 4 were 7224 pg/mL (4766 to 10,254 mg/dL), 8958 pg/mL (4935 to 11,271 mg/dL), 9280 pg/mL (9195 to 10,384 mg/dL) and 12,683 pg/mL (9133 to 19,217 mg/dL), respectively. Group 4, estimated to have the highest reduction in glomerular filtration rate, had a higher plasma N-terminal pro-atrial natriuretic peptide concentration than Groups 1 to 3. Based on the final generalised linear model, influencing factors for plasma N-terminal pro-atrial natriuretic peptide concentration were plasma iohexol clearance (-0.136; 95% confidence interval, -0.227 to -0.046) and bodyweight (-0.058; 95% confidence interval, -0.098 to -0.018).

CLINICAL SIGNIFICANCE

N-terminal pro-atrial natriuretic peptide concentration is associated with the glomerular filtration rate.

Pleiotropic Roles of Atrial Natriuretic Peptide in Anti-Inflammation and Anti-Cancer Activity

Simple Summary

The relationship between inflammation and carcinogenesis, as well as the response to anti-tumor therapy, is intimate. Atrial natriuretic peptides (ANPs) play a pivotal role in the homeostatic control of blood pressure, electrolytes, and water balance. In addition, ANPs exert immune-modulatory effects in the tissue microenvironment, thus exhibiting a fascinating ability to prevent inflammation-related tumorigenesis and cancer recurrence. In cancers, ANPs show anti-proliferative effects through several molecular pathways. Furthermore, ANPs attenuate the side effects of cancer therapy. Therefore, ANPs have potential therapeutic value in tumors. Here, we summarized the roles of ANPs in diverse aspects of the immune system and the molecular mechanisms underlying the anti-cancer effects of ANPs, contributing to the development of ANP-based anti-cancer agents.

Abstract

The atrial natriuretic peptide (ANP), a cardiovascular hormone, plays a pivotal role in the homeostatic control of blood pressure, electrolytes, and water balance and is approved to treat congestive heart failure. In addition, there is a growing realization that ANPs might be related to immune response and tumor growth. The anti-inflammatory and immune-modulatory effects of ANPs in the tissue microenvironment are mediated through autocrine or paracrine mechanisms, which further suppress tumorigenesis. In cancers, ANPs show anti-proliferative effects through several molecular pathways. Furthermore, ANPs attenuate the side effects of cancer therapy. Therefore, ANPs act on several hallmarks of cancer, such as inflammation, angiogenesis, sustained tumor growth, and metastasis. In this review, we summarized the contributions of ANPs in diverse aspects of the immune system and the molecular mechanisms underlying the anti-cancer effects of ANPs.

Interactions between the enhanced recovery after surgery pathway and risk factors for lung infections after pulmonary malignancy operation

Background

Lung infection is a common complication after thoracic surgery and can lead to severe consequences. Our study was designed to explore the risk factors for postoperative lung infections (POLI) following pulmonary malignancy operation and assess the protective effect of enhanced recovery after surgery (ERAS) and their potential interactive relationships.

Methods

A retrospective study included 1,768 patients who underwent surgery between 2013 and 2017 in Ruijin Hospital, Shanghai Jiaotong University School of Medicine was performed. Uni- and multivariate analyses were performed to identify risk factors. Andersson’s model was applied to evaluate the additive interaction between these factors.

Results

Smoking [95% confidence interval (CI): 1.178–2.198], preoperative heart disease (95% CI: 1.448–4.091), and massive intraoperative blood loss (95% CI: 1.568–3.674) were independent risk factors for postoperative lung infections (POLI), whereas ERAS implementation was protective (95% CI: 0.249–0.441). Interaction analyses indicated that non-ERAS was reciprocally independent with smoking and surgical procedure. It had a synergistic interaction with heart disease [attributable proportion due to interaction (AP) =0.540 (95% CI: 0.179–0.901), synergy index (S) =2.580 (95% CI: 1.016–6.551)], and poor lung function [AP =0.395 (95% CI: 0.016–0.775)], as well as a tendency of antagonistic interaction with blood loss.

Conclusions

Intraoperative blood loss, heart disease, and smoking are independent risk factors of POLI. ERAS implementation is a protective factor and is firstly verified to be more effective on reducing POLI in patients with heart diseases, poor lung function, and less intraoperative blood loss. We provide evidences to implement ERAS and a clue of the most optimal indications for ERAS.

Overcoming Obstacles to Drug Repositioning in Japan

Drug repositioning (DR) is the process of identifying new indications for existing drugs. DR usually focuses on drugs that have cleared phase-I safety trials but has yet to show efficacy for the intended indication. Therefore, DR can probably skip the preclinical and phase-I study, which can reduce the cost throughout drug development. However, the expensive phase-II/III trials are required to establish efficacy. The obstacles to DR include identification of new indications with a high success rate in clinical studies, obtaining funding for clinical studies, patent protection, and approval systems. To tackle these obstacles, various approaches have been applied to DR worldwide. In this perspective, we provide representative examples of DR and discuss the ongoing efforts to overcome obstacles to DR in Japan.

Transcriptome analysis reveals a role for the endothelial ANP-GC-A signaling in interfering with pre-metastatic niche formation by solid cancers

Cancer establishes a microenvironment called the pre-metastatic niche in distant organs where disseminated cancer cells can efficiently metastasize. Pre-metastatic niche formation requires various genetic factors. Previous studies suggest that inhibiting a single niche-factor is insufficient to completely block pre-metastatic niche formation especially in human patients. Here we show that the atrial natriuretic peptide (ANP), an endogenous hormone produced by the heart, inhibits pre-metastatic niche formation and metastasis of murine solid cancer models when pharmacologically supplied in vivo. On the basis of a wealth of comprehensive RNA-seq data, we demonstrated that ANP globally suppressed expression of cancer-induced genes including known niche-factors in the lung. The lungs of mice overexpressing GC-A, a receptor for ANP in endothelial cells, were conferred resistance against pre-metastatic niche formation. Importantly, neither ANP administration nor GC-A overexpression had a detrimental effect on lung gene expression in a cancer-free condition. The current study establishes endothelial ANP-GC-A signaling as a therapeutic target to control the pre-metastatic niche.

A multicenter randomized controlled trial of surgery alone or surgery with atrial natriuretic peptide in lung cancer surgery: study protocol for a randomized controlled trial

Background

Postoperative cancer recurrence is a major problem following curative surgery. In a previous retrospective study of lung cancer surgery, we reported that administration of atrial natriuretic peptide (ANP) during the perioperative period reduced postoperative recurrence. We demonstrated that ANP inhibited the adhesion of cancer cells to vascular endothelium as a vasoprotective action. The objective of this study is to evaluate the effects of ANP on the incidence of postoperative cancer recurrence in lung cancer surgery.

Methods/design

The present study is a multicenter, randomized trial with two parallel groups of patients with lung cancer comparing surgery alone and surgery with ANP administration for 3 days during the perioperative period. A total of 500 patients will be enrolled from 10 Japanese institutions. The primary endpoint is 2-year relapse-free survival (RFS). The secondary endpoints are 2-year cancer-specific RFS, 5-year RFS, overall survival, the incidence of postoperative complications, and the completion rate of ANP treatment.

Discussion

The principal question addressed in this trial is whether ANP with its vasoprotective action can reduce cancer recurrence following lung cancer surgery.

Trial registration

UMIN Clinical Trials Registry identifier: UMIN000018480. Registered on 31 July 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1928-1) contains supplementary material, which is available to authorized users.

Atrial natriuretic peptide protects against bleomycin-induced pulmonary fibrosis via vascular endothelial cells in mice : ANP for pulmonary fibrosis

Background

Pulmonary fibrosis is a life-threatening disease characterized by progressive dyspnea and worsening pulmonary function. Atrial natriuretic peptide (ANP), a heart-derived secretory peptide used clinically in Japan for the treatment of acute heart failure, exerts a wide range of protective effects on various organs, including the heart, blood vessels, kidneys, and lungs. Its therapeutic properties are characterized by anti-inflammatory and anti-fibrotic activities mediated by the guanylyl cyclase-A (GC-A) receptor. We hypothesized that ANP would have anti-fibrotic and anti-inflammatory effects on bleomycin (BLM)-induced pulmonary fibrosis in mice.

Methods

Mice were divided into three groups: normal control, BLM with vehicle, and BLM with ANP. ANP (0.5 μg/kg/min via osmotic-pump, subcutaneously) or vehicle administration was started before BLM administration (1 mg/kg) and continued until the mice were sacrificed. At 7 or 21 days after BLM administration, fibrotic changes and infiltration of inflammatory cells in the lungs were assessed based on histological findings and analysis of bronchoalveolar lavage fluid. In addition, fibrosis and inflammation induced by BLM were evaluated in vascular endothelium-specific GC-A overexpressed mice. Finally, attenuation of transforming growth factor-β (TGF-β) signaling by ANP was studied using immortalized mouse endothelial cells stably expressing GC-A receptor.

Results

ANP significantly decreased lung fibrotic area and infiltration of inflammatory cells in lungs after BLM administration. Furthermore, similar effects of ANP were observed in vascular endothelium–specific GC-A overexpressed mice. In cultured mouse endothelial cells, ANP reduced phosphorylation of Smad2 after TGF-β stimulation.

Conclusions

ANP exerts protective effects on BLM-induced pulmonary fibrosis via vascular endothelial cells.

Long-Term Impact of Postoperative Complications on Cancer Recurrence Following Lung Cancer Surgery

BACKGROUND

Postoperative complications are associated with poor cancer-specific survival in various types of cancer surgery. Recent studies suggest that systemic inflammation induced by surgical trauma can accelerate the adhesion of circulating tumor cells to the vascular endothelium of distant organs, resulting in early cancer recurrence. We investigated the impact of postoperative cardiopulmonary complications on cancer recurrence following lung cancer surgery.

METHODS

From a prospective database of 675 consecutive patients who underwent curative surgery for lung cancer between 2007 and 2012, the incidence of postoperative cardiopulmonary complications, white blood cell counts, and C-reactive protein levels were evaluated in the acute phase after surgery. Four patients had both cardiovascular and respiratory complications. The remaining 671 patients were divided into 3 groups: patients without cardiopulmonary complications; those with cardiovascular complications; and those with respiratory complications. The incidence of cancer recurrence was compared among the three groups.

RESULTS

Postoperative cardiovascular or respiratory complications were identified in 94 (14%) or 25 (4%) patients, respectively. Postoperative white blood cell counts and C-reactive protein levels were significantly higher in those with postoperative respiratory complications than in those without. There was a significantly higher incidence of cancer recurrence in those with postoperative respiratory complications than in those without (48.0 vs. 16.8%; p < 0.0001). Multiple regression analysis adjusted for age, sex, and pathological staging showed that the incidence of postoperative respiratory complications was a significant predictor of cancer recurrence.

CONCLUSIONS

The presence of respiratory complications following lung cancer surgery was a significant predictor of cancer recurrence.

Atrial natriuretic peptide protects against cisplatin-induced granulocytopenia

PURPOSE

Granulocytopenia is the major toxicity associated with cisplatin treatment. Atrial natriuretic peptide (ANP) is a cardiac hormone used clinically for the treatment of acute heart failure in Japan. ANP exerts a wide range of protective effects on various organs, including the heart, blood vessels, lungs, and kidneys. This study's objective was to investigate the protective effects of ANP on cisplatin-induced granulocytopenia in mice.

METHODS

The mice were divided into two groups: cisplatin with vehicle and cisplatin with ANP. ANP (1.5 μg/kg/min via osmotic pump, subcutaneously) or vehicle administration was started 1 day before cisplatin injection until the mice were killed. At 0, 2, 4, 8, and 14 days after cisplatin injection (16 mg/kg, intraperitoneally as a single dose), the white blood cell, red blood cell, and platelet counts were measured in the peripheral blood in both groups. The numbers of total and live cells and colony-forming unit-granulocyte-macrophage (CFU-GM) colonies in the bone marrow of the mice were also examined. In addition, at 0, 0.5, 1, and 2 days after cisplatin injection, serum granulocyte colony-stimulating factor (G-CSF) levels were measured.

RESULTS

ANP significantly attenuated the white blood cell count decrease in the peripheral blood 2 and 4 days after cisplatin injection. ANP also attenuated the decrease in the number of live cells and CFU-GM colonies in bone marrow 2, 4, and 8 days after cisplatin injection. ANP significantly increased serum G-CSF levels 1 day after cisplatin injection.

CONCLUSIONS

ANP has protective effects in cisplatin-induced granulocytopenia, with increased G-CSF production.

Atrial natriuretic peptide prevents cancer metastasis through vascular endothelial cells

Most patients suffering from cancer die of metastatic disease. Surgical removal of solid tumors is performed as an initial attempt to cure patients; however, surgery is often accompanied with trauma, which can promote early recurrence by provoking detachment of tumor cells into the blood stream or inducing systemic inflammation or both. We have previously reported that administration of atrial natriuretic peptide (ANP) during the perioperative period reduces inflammatory response and has a prophylactic effect on postoperative cardiopulmonary complications in lung cancer surgery. Here we demonstrate that cancer recurrence after curative surgery was significantly lower in ANP-treated patients than in control patients (surgery alone). ANP is known to bind specifically to NPR1 [also called guanylyl cyclase-A (GC-A) receptor]. In mouse models, we found that metastasis of GC-A-nonexpressing tumor cells (i.e., B16 mouse melanoma cells) to the lung was increased in vascular endothelium-specific GC-A knockout mice and decreased in vascular endothelium-specific GC-A transgenic mice compared with control mice. We examined the effect of ANP on tumor metastasis in mice treated with lipopolysaccharide, which mimics systemic inflammation induced by surgical stress. ANP inhibited the adhesion of cancer cells to pulmonary arterial and micro-vascular endothelial cells by suppressing the E-selectin expression that is promoted by inflammation. These results suggest that ANP prevents cancer metastasis by inhibiting the adhesion of tumor cells to inflamed endothelial cells.

Atrial natriuretic peptide inhibits lipopolysaccharide-induced acute lung injury

OBJECTIVES

We recently reported that administration of atrial natriuretic peptide during the perioperative period has prophylactic effects with respect to not only cardiovascular but also respiratory complications following pulmonary resection. However, its mechanisms are not well understood. The objective of the present study was to investigate the mechanism of the prophylactic effects of atrial natriuretic peptide in an acute lung injury model.

METHODS

For the evaluation of the early phase of pulmonary inflammation, in vitro and in vivo studies using lipopolysaccharide were used. In the in vitro study, the effects of atrial natriuretic peptide on the induction of E-selectin by lipopolysaccharide in human pulmonary artery endothelial cells were evaluated. In the in vivo study, the effects of atrial natriuretic peptide on lipopolysaccharide-induced inflammatory cell infiltration and cytokine levels including tumor necrosis factor-alpha and interleukin-6 in the bronchoalveolar lavage fluid in the lungs of C57/B6 mice were examined. The number of myeloperoxidase-positive staining cells in the tissue sections of the lung of lipopolysaccharide-administered C57/B6 mice was also evaluated.

RESULTS

Atrial natriuretic peptide significantly attenuated the up-regulation of E-selectin expression induced by lipopolysaccharide in human pulmonary artery endothelial cells. There were significantly lower cell counts and levels of tumor necrosis factor-alpha and interleukin-6 in the bronchoalveolar lavage fluid of atrial natriuretic peptide-treated mice compared to control mice after lipopolysaccharide injection. In addition, there were significantly fewer myeloperoxidase-positive cells in atrial natriuretic peptide-treated mice than in control mice after lipopolysaccharide injection.

CONCLUSIONS

Atrial natriuretic peptide had a protective effect in the lipopolysaccharide-induced acute lung injury model. Atrial natriuretic peptide may be of value in therapeutic strategies aimed at the treatment of acute lung injury such as pneumonia or acute respiratory distress syndrome.

Insights into onco-cardiology: atrial fibrillation in cancer

Atrial fibrillation (AF) has been found to occur with an increased frequency in patients with malignancies, particularly in those undergoing cancer surgery. The occurrence of AF in cancer may be related to comorbid states or a direct tumor effect or may represent a complication of cancer surgical or medical therapy, whereas inflammation may be a common denominator for both conditions. Treating AF in patients with malignancies is a challenge, especially in terms of antithrombotic therapy, because cancer may result in an increased risk of either thrombosis or hemorrhage and an unpredictable anticoagulation response, whereas thromboembolic risk prediction scores such as CHADS2 (Cardiac Failure, Hypertension, Age, Diabetes, and Stroke [doubled]) may not be applicable. The general lack of evidence imposes an individualized approach to the management of AF in those patients, although some general recommendations based on current guidelines in noncancer patients and the existing evidence in cancer patients, where available, may be outlined.