Increase In Tumor Blood Flow Research Articles

Tolerable treatment of glioblastoma with redox-cycling ‘mitocans': a comparative study in vivo

ABSTRACTObjectives: The present study describes a pharmacological strategy for the treatment of glioblastoma by redoxcycling ‘mitocans’ such as quinone/ascorbate combination drugs, based on their tumor-selective redox-modulating effects and tolerance to normal cells and tissues.Methods: Experiments were performed on glioblastoma mice (orthotopic model) treated with coenzyme Q0/ascorbate (Q0/A). The drug was injected intracranially in a single dose. The following parameters were analyzed in vivo using MRI orex vivo using conventional assays: tumor growth, survival, cerebral and tumor perfusion, tumor cell density, tissue redox-state, and expression of tumor-associated NADH oxidase (tNOX).Results: Q0/A markedly suppressed tumor growth and significantly increased survival of glioblastoma mice. This was accompanied by increased oxidative stress in the tumor but not in non-cancerous tissues, increased tumor blood flow, and downregulation of tNOX. The redox-modulating and anticancer effects of Q0/A were more pronounced than those of menadione/ascorbate (M/A) obtained in our previous study. No adverse drug-related side-effects were observed in glioblastoma mice treated with Q0/A.Discussion: Q0/A differentiated cancer cells and tissues, particularly glioblastoma, from normal ones by redox targeting, causing a severe oxidative stress in the tumor but not in non-cancerous tissues. Q0/A had a pronounced anticancer activity and could be considered safe for the organism within certain concentration limits. The results suggest that the rate of tumor resorption and metabolism of toxic residues must be controlled and maintained within tolerable limits to achieve longer survival, especially at intracranial drug administration.

Nitroglycerin-induced downregulation of AKT- and ERK1/2-mediated radiation-sensitive 52 expression to enhance pemetrexed-induced cytotoxicity in human lung cancer cells.

Nitroglycerin (NTG)-a nitric oxide-donating drug-is traditionally administered via the sublingual route to treat acute myocardial angina attacks. NTG also increases tumor blood flow and, consequently, cancer drug delivery to tumor cells. In the homologous recombination pathway, radiation-sensitive 52 (Rad52) plays a crucial role in DNA repair by promoting the annealing of complementary single-stranded DNA and stimulating radiation-sensitive 51 (Rad51) recombinase activity. Pemetrexed-a multitargeted antifolate agent-exhibits satisfactory clinical activity in wild-type nonsquamous non-small-cell lung cancer (NSCLC) cells. However, the synergistic activity of combination therapy with NTG and pemetrexed against NSCLC cells has not yet been clarified. In 2 NSCLC cell lines (i.e. lung squamous cell carcinoma H520 and lung adenocarcinoma H1975 cells), NTG reduced Rad52 expression; in addition, decreased phospho-AKT and phospho-ERK1/2 protein levels were observed. Enhancement of AKT or ERK1/2 activity through transfection with a constitutively active AKT (AKT-CA) vector or constitutively active mitogen-activated protein kinase kinase 1 (MKK1-CA) vector increased the Rad52 protein level and cell survival, which were suppressed by NTG. The knockdown of Rad52 expression by using small interfering RNA or by inhibiting AKT and ERK1/2 activity enhanced the cytotoxicity and cell growth inhibition induced by NTG. Moreover, NTG synergistically enhanced the cytotoxicity and cell growth inhibition induced by pemetrexed in NSCLC cells; these effects were associated with AKT and ERK1/2 inactivation and, consequently, Rad52 downregulation in H520 and H1975 cells. The results provide a rationale for combining NTG and pemetrexed in lung cancer treatment to improve lung cancer control.

Promoting Nanoparticle Delivery Efficiency to Tumors by Locally Increasing Blood Flow There.

Enhancing the tumor-targeted delivery efficiency of nanoparticles is necessary for improving their therapeutic efficacy, yet how to fulfill this, especially in a practical manner, remains a significant challenge. Noticing that major organs compete effectively with tumors for nanoparticles, we herein carried out meta-analysis on nanoparticle delivery efficiency to major organs and tumors. Notably, in major organs, cellular uptake alone cannot explain why one organ has higher nanoparticle delivery efficiency than another; indeed, blood flow through an organ may facilitate nanoparticle delivery efficiency there as well. Intriguingly, such a facilitative role can be extrapolated to tumors, according to meta-analysis on the relationship of tumor-targeted delivery efficiency of nanoparticles versus blood flow through tumors of different weights. Indeed, using local mild hyperthermia as a model for modalities capable of increasing tumor blood flow, we observed a ∼3-fold increase in tumor-targeted delivery efficiency in the meta-analysis on studies involving both nanoparticles and local mild hyperthermia. This work identifies tumor blood flow as a crucial factor in determining tumor-targeted delivery efficiency of nanoparticles and suggests increasing tumor blood flow as an alternative way to boost tumor-targeted delivery efficiency of nanoparticles.

Unraveling the role of Intralipid in suppressing off-target delivery and augmenting the therapeutic effects of anticancer nanomedicines

Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress off-target delivery of anticancer nanomedicines; Intralipid also effectively improved drug delivery to tumors and produced better therapeutic effects. However, the mechanisms involved—the why and how—in Intralipid's facilitation of delivery of nanomedicines to tumors have not yet been reported in detail. In this study, we investigated Intralipid and discovered the beneficial effects of Intralipid pretreatment when using three anticancer nanomedicines, including the clinically approved drug doxorubicin (Doxil). Intralipid pretreatment induced a 40% reduction in liver uptake of a polymeric nanoprobe used in photodynamic therapy as well as a 1.5-fold-increased nanomedicine accumulation in tumors. This increased accumulation consequently led to significantly better therapeutic effects, and this finding was validated by using Doxil. As an interesting result, Intralipid pretreatment significantly prolonged the plasma half-life of nanomedicines in normal healthy mice but not in tumor-bearing mice, which suggests that tumors become an alternative route of nanomedicine delivery when liver delivery is suppressed. Also, we found markedly increased tumor blood flow, as measured by fluorescence angiography, and significantly lower blood viscosity after Intralipid pretreatment. All our results together indicate that Intralipid treatment not only suppressed off-target nanomedicine delivery by the reticuloendothelial system, but more important, it enhanced nanomedicine delivery to tumors by improving tumor blood flow, which is key to satisfactory drug delivery via the enhanced permeability and retention effect. Significantly better therapeutic outcomes were thus achieved by the strategy of combining utilization of nanomedicines and Intralipid pretreatment. Statement of significanceOff-target delivery to organs such as the liver and obstructed tumor blood flow as is often seen in advanced cancers are major barriers to the therapeutic efficacy of anticancer nanomedicines. Intralipid has been shown effective for suppressing nanomedicine accumulation in the liver, resulting in improved anticancer effects. Unraveling the mechanisms involved in this process will be greatly helpful for the clinical application of anticancer nanomedicines. We reported here that Intralipid could also significantly increase tumor delivery of nanomedicine, which is beneficial for improving tumor blood flow and lowering blood viscosity. To our knowledge, this is the first study to investigate the role of Intralipid in this regard. This knowledge provides a solid rationale for the use of Intralipid in combination with anticancer nanomedicines.

MiR-744/eNOS/NO axis: A novel target to halt triple negative breast cancer progression.

Nitric oxide (NO) may have a dual role in cancer. At low concentrations, endogenous NO promotes tumor growth and proliferation. However, at very high concentrations, it mediates cancer cell apoptosis and inhibits cancer growth. High levels of NO have been observed in blood of breast cancer (BC) patients, which increases tumor blood flow and promotes angiogenesis. To date, the regulation of NO-synthesizing enzyme, eNOS, by miRNAs has not been adequately investigated in BC. Therefore, the main aim of this study is to unravel the possible regulation of eNOS by miRNAs in BC and to examine their influence on NO production and BC progression. Expression profile of eNOS in Egyptian BC patients and MDA-MB-231 cell lines was investigated using qRT-PCR. In-silico analysis was performed to predict a putative upstream regulator of eNOS. miR-744-5p was selected and its expression was quantified in BC tissues using qRT-PCR. MDA-MB-231 cells were cultured and transfected with miR-744-5p using lipofection method. NO levels were determined using Griess Reagent. Cellular viability and colony-forming ability were assessed using MTT and colony-forming assays; respectively. eNOS and miR-744-5p were significantly up-regulated in BC tissues compared to paired normal tissues. In-silico analysis revealed that miR-744-5p putatively binds to eNOS transcript with high binding scores. Transfection of MDA-MB-231 cells with miR-744-5p mimics resulted in a significant up-regulation of eNOS and consequently NO levels. In addition, miR-744-5p transfection led to an increase in cellular viability and colony-forming ability of the MDA-MB-231. miR-744-5p acts as an upstream positive regulator of the NO synthesizing enzyme, eNOS which in turn elevates NO levels. Furthermore, miR-744-5p is a novel oncogenic miRNA in BC. Thus, targeting miR-744/eNOS/NO axis may act as a therapeutic tool in TNBC.

Angiotensin II type 1 receptor blocker telmisartan inhibits the development of transient hypoxia and improves tumour response to radiation.

Hypoxic tumour cells are radiation-resistant and are associated with poor therapeutic outcome. A poorly understood source of tumour hypoxia is unstable perfusion, which exposes tumour cells to varying oxygen tensions over time creating "transiently" hypoxic cells. Evidence suggests that angiotensin II type 1 receptor blockers (ARBs) can improve tumour perfusion by reducing collagen deposition from cancer associated fibroblasts (CAFs). However, the influence of ARBs on transient hypoxia and tumour radiation response is unknown. We tested how the ARBs losartan and telmisartan affected the solid tumour microenvironment, using fluorescent perfusion dyes and positron emission tomography to quantify tumour perfusion, and a combination of hypoxia markers and the hemorheological agent pentoxifylline to assess transient tumour hypoxia. We found CAF-containing tumours have reduced collagen I levels in response to telmisartan, but not losartan. Telmisartan significantly increased tumour blood flow, stabilized microregional tumour perfusion, and decreased tumour hypoxia by reducing the development of transient hypoxia. Telmisartan-treated tumours were more responsive to radiation, indicating that telmisartan reduces a therapeutically important population of transiently hypoxic tumour cells. Our findings indicate telmisartan is capable of modifying the tumour microenvironment to stabilize tumour perfusion, reduce transient hypoxia, and improve tumour radiation response.

Hyperthermia can alter tumor physiology and improve chemo- and radio-therapy efficacy

Hyperthermia has demonstrated clinical success in improving the efficacy of both chemo- and radio-therapy in solid tumors. Pre-clinical and clinical research studies have demonstrated that targeted hyperthermia can increase tumor blood flow and increase the perfused fraction of the tumor in a temperature and time dependent manner. Changes in tumor blood circulation can produce significant physiological changes including enhanced vascular permeability, increased oxygenation, decreased interstitial fluid pressure, and reestablishment of normal physiological pH conditions. These alterations in tumor physiology can positively impact both small molecule and nanomedicine chemotherapy accumulation and distribution within the tumor, as well as the fraction of the tumor susceptible to radiation therapy. Hyperthermia can trigger drug release from thermosensitive formulations and further improve the accumulation, distribution, and efficacy of chemotherapy.

Nitroglycerin Enhances Cisplatin-Induced Cytotoxicity via AKT Inactivation and Thymidylate Synthase Downregulation in Human Lung Cancer Cells

Nitroglycerin (NTG), a nitric oxide-donating drug, may increase tumor blood flow and consequently increase cancer drug delivery to tumor cells. Thymidylate synthase (TS) is an essential enzyme for the de novo synthesis of deoxythymidine monophosphate; we had found that knocking down the expression of TS sensitizes lung cancer cells to cisplatin-induced cytotoxicity. However, whether NTG and cisplatin could induce synergistic cytotoxicity in nonsmall cell lung cancer (NSCLC) cells through modulating TS expression is unknown. In this study, NTG decreased TS expression in an AKT, also known as Protein kinase B (PKB) inactivation dependent manner in human lung adenocarcinoma A549 and squamous cell carcinoma H1703 cells. Enhancement of AKT activity by transfection with constitutive active AKT vectors increased the TS expression level as well as the cell survival pretreated by NTG. Moreover, NTG synergistically enhanced cytotoxicity and cell growth inhibition by cisplatin treatment in NSCLC cells, which were associated with downregulation of TS expression and inactivation of AKT in A549 and H1703 cells. Together, these results may provide a rationale to combine NTG with cisplatin-based chemotherapy to enhance the therapeutic effect for lung cancer in the future.

Abstract PD8-06: Fluorescence guided breast conserving surgery

Abstract Background. Palpation guided breast conserving surgery for breast cancer is associated with tumor involved margins in up to 41% of cases. Ultrasound guided breast conserving surgery and frozen section biopsy result in a significant reduction in margin positivity. However, intra-operative USG and Frozen section biopsy are not widely available. We aimed to find a simple and effective technique for intra-operative margin assessment during breast conserving surgery. Hypothesis. Intravenously injected Fluorescein reaches tumor tissue in high concentration due to increased tumor blood flow and increased capillary permeability which can be detected by blue light (494 nm). Objective. To find diagnostic accuracy of fluorescence guided identification of tumor margins during breast conserving surgery. Methods. A total of 60 patients with T1–T2 invasive breast cancer who underwent breast conserving surgery at AIIMS, New Delhi between March, 2016 to Feb, 2018 were included. Each patient received 2 ml of intra-venous 20% Fluorescein sodium just before skin incision. Breast conserving surgery was performed under USG guidance. Specimen was bisected and examined under blue light. Fluorescent tumor margins were identified and six biopsies taken from non-fluorescent area 5mm outside from fluorescent tumor margins at 2,4,6,8,10 and 12 o'clock position. The involvement of USG guided margin was compared with Fluorescence guided margins on histopathology. Results. Mean age of the patient was 51.2 (SD=6.4) years. Fourteen patients (20.3 %) had T1 tumors while 46 patients(69.7%) had T2 tumors. Axillary nodes were involved in 19 patients (20.1%) and all underwent axillary node dissection. Eight patients (13.3%) received NACT. Fluorescent margins in two (3.3%) out of 60 patients were involved by tumor while USG guided margins in all the 60 patients were free. The specificity of fluorescence in identifying uninvolved tumor margins during breast conserving surgery is 96.7%. No patient developed adverse drug reactions. Conclusion. The fluorescence identifies tumor free margins with 96.7% accuracy. It is simple, effective and affordable method of identifying margin positivity in breast conservation surgery. Citation Format: Sharma CK, Ranjan P, Qaiser D, Dhar A, Srivastava A, Kataria K. Fluorescence guided breast conserving surgery [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-06.

Intracellularly Activatable Nanovasodilators To Enhance Passive Cancer Targeting Regime.

Conventional cancer targeting with nanoparticles has been based on the assumed enhanced permeability and retention (EPR) effect. The data obtained in clinical trials to date, however, have rarely supported the presence of such an effect. To address this challenge, we formulated intracellular nitric oxide-generating nanoparticles (NO-NPs) for the tumor site-specific delivery of NO, a well-known vasodilator, with the intention of boosting EPR. These nanoparticles are self-assembled under aqueous conditions from amphiphilic copolymers of poly(ethylene glycol) and nitrated dextran, which possesses inherent NO release properties in the reductive environment of cancer cells. After systemic administration of the NO-NPs, we quantitatively assessed and visualized increased tumor blood flow as well as enhanced vascular permeability than could be achieved without NO. Additionally, we prepared doxorubicin (DOX)-encapsulated NO-NPs and demonstrated consequential improvement in therapeutic efficacy over the control groups with considerably improved DOX intratumoral accumulation. Overall, this proof of concept study implies a high potency of the NO-NPs as an EPR enhancer to achieve better clinical outcomes.

Exercise and the Tumor Microenvironment: Potential Therapeutic Implications.

An imbalance in oxygen delivery to demand in solid tumors results in local areas of hypoxia leading to poor prognosis for the patient. We hypothesize that aerobic exercise increases tumor blood flow, recruits previously nonperfused tumor blood vessels, and thereby augments blood-tumor O2 transport and diminishes tumor hypoxia. When combined with conventional anticancer treatments, aerobic exercise can significantly improve the outcomes for several types of cancers.

18F]FDG PET/CT-based response assessment of stage IV non-small cell lung cancer treated with paclitaxel-carboplatin-bevacizumab with or without nitroglycerin patches

PurposeNitroglycerin (NTG) is a vasodilating drug, which increases tumor blood flow and consequently decreases hypoxia. Therefore, changes in [18F] fluorodeoxyglucose positron emission tomography ([18F]FDG PET) uptake pattern may occur. In this analysis, we investigated the feasibility of [18F]FDG PET for response assessment to paclitaxel-carboplatin-bevacizumab (PCB) treatment with and without NTG patches. And we compared the [18F]FDG PET response assessment to RECIST response assessment and survival.MethodsA total of 223 stage IV non-small cell lung cancer (NSCLC) patients were included in a phase II study (NCT01171170) randomizing between PCB treatment with or without NTG patches. For 60 participating patients, a baseline and a second [18F]FDG PET/computed tomography (CT) scan, performed between day 22 and 24 after the start of treatment, were available. Tumor response was defined as a 30 % decrease in CT and PET parameters, and was compared to RECIST response at week 6. The predictive value of these assessments for progression free survival (PFS) and overall survival (OS) was assessed with and without NTG.ResultsA 30 % decrease in SUVpeak assessment identified more patients as responders compared to a 30 % decrease in CT diameter assessment (73 % vs. 18 %), however, this was not correlated to OS (SUVpeak30 p = 0.833; CTdiameter30 p = 0.557). Changes in PET parameters between the baseline and the second scan were not significantly different for the NTG group compared to the control group (p value range 0.159–0.634). The CT-based (part of the [18F]FDG PET/CT) parameters showed a significant difference between the baseline and the second scan for the NTG group compared to the control group (CT diameter decrease of 7 ± 23 % vs. 19 ± 14 %, p = 0.016, respectively).ConclusionsThe decrease in tumoral FDG uptake in advanced NSCLC patients treated with chemotherapy with and without NTG did not differ between both treatment arms. Early PET-based response assessment showed more tumor responders than CT-based response assessment (part of the [18F]FDG PET/CT); this was not correlated to survival. This might be due to timing of the [18F]FDG PET shortly after the bevacizumab infusion.

A randomized phase II study comparing paclitaxel–carboplatin–bevacizumab with or without nitroglycerin patches in patients with stage IV nonsquamous nonsmall-cell lung cancer: NVALT12 (NCT01171170)

BackgroundNitroglycerin (NTG) increases tumor blood flow and oxygenation by inhibiting hypoxia-inducible-factor (HIF)-1. A randomized phase II study has shown improved outcome when NTG patches were added to vinorelbine/cisplatin in patients with advanced nonsmall-cell lung cancer (NSCLC). In addition, there is evidence that the combination of bevacizumab and HIF-1 inhibitors increases antitumor activity. Patients and methodsIn this randomized phase II trial, chemo-naive patients with stage IV nonsquamous NSCLC were randomized to four cycles of carboplatin (area under the curve 6)–paclitaxel (200mg/m2)–bevacizumab 15mg/kg on day 1 every 3 weeks with or without NTG patches 15mg (day -2 to +2) followed by bevacizumab with or without NTG until progression. Response was assessed every two cycles. Primary end point was progression-free survival (PFS). The study was powered (80%) to detect a decrease in the hazard of tumor progression of 33% at α = 0.05 with a two-sided log-rank test when 222 patients were enrolled and followed until 195 events were observed. ResultsBetween 1 January 2011 and 1 January 2013, a total of 223 patients were randomized; 112 control arm and 111 experimental arm; response rate was 54% in control arm and 38% in experimental arm. Median [95% confidence interval (CI)] PFS in control arm was 6.8 months (5.6–7.3) and 5.1 months (4.2–5.8) in experimental arm, hazard ratio (HR) 1.27 (95% CI 0.96–1.67). Overall survival (OS) was 11.6 months (8.8–13.6) in control arm and 9.4 months (7.8–11.3) in experimental arm, HR 1.02 (95% CI 0.71–1.46). In the experimental arm, no additional toxicity was observed except headache (6% versus 52% in patients treated with NTG). ConclusionAdding NTG to first-line carboplatin–paclitaxel–bevacizumab did not improve PFS and OS in patients with stage IV nonsquamous NSCLC.

NO to cancer: The complex and multifaceted role of nitric oxide and the epigenetic nitric oxide donor, RRx-001

The endogenous mediator of vasodilation, nitric oxide (NO), has been shown to be a potent radiosensitizer. However, the underlying mode of action for its role as a radiosensitizer – while not entirely understood – is believed to arise from increased tumor blood flow, effects on cellular respiration, on cell signaling, and on the production of reactive oxygen and nitrogen species (RONS), that can act as radiosensitizers in their own right. NO activity is surprisingly long-lived and more potent in comparison to oxygen. Reports of the effects of NO with radiation have often been contradictory leading to confusion about the true radiosensitizing nature of NO. Whether increasing or decreasing tumor blood flow, acting as radiosensitizer or radioprotector, the effects of NO have been controversial. Key to understanding the role of NO as a radiosensitizer is to recognize the importance of biological context. With a very short half-life and potent activity, the local effects of NO need to be carefully considered and understood when using NO as a radiosensitizer. The systemic effects of NO donors can cause extensive side effects, and also affect the local tumor microenvironment, both directly and indirectly. To minimize systemic effects and maximize effects on tumors, agents that deliver NO on demand selectively to tumors using hypoxia as a trigger may be of greater interest as radiosensitizers. Herein we discuss the multiple effects of NO and focus on the clinical molecule RRx-001, a hypoxia-activated NO donor currently being investigated as a radiosensitizer in the clinic.

MRI-Tracked Tumor Vascular Changes in the Hours after Single-Fraction Irradiation.

The purpose of this study was to characterize changes in tumor vascular parameters hours after a single radiation exposure in an orthotopic brain tumor model. U-251 human brain tumors were established intracerebrally in rat brains, and tumor blood flow, forward volume transfer constant (K(trans)) and interstitial volume fraction (v(e)) were measured using magnetic resonance imaging (MRI). Tumors were exposure to a single stereotactic radiation treatment of 20 Gy. Vascular parameters were assessed one additional time between 2 and 24 h after irradiation. After the second MRI session, brain tissue histology was examined for gross changes and apoptosis. In separate studies, cerebral blood flow was measured in nonimplanted controls before radiation exposure and 2 and 24 h after 20 Gy irradiation, and in implanted rats before radiation exposure and at 2 and 24 h after 6 Gy irradiation. Significant changes were observed in tumor-bearing rat brains in the hours after 20 Gy irradiation. Two hours after 20 Gy irradiation, tumor blood flow decreased nearly 80% and ve decreased by 30%. At 4 h, the K(trans) increased by 30% over preirradiation values. Extensive vacuolization and an increase in apoptosis were evident histologically in rats imaged 2 h after irradiation. Between 8 and 12 h after irradiation, all vascular parameters including blood flow returned to near preirradiation values. One day after irradiation, tumor blood flow was elevated 40% over preirradiation values, and other vascular parameters, including K(trans) and ve, were 20-40% below preirradiation values. In contrast, changes in vascular parameters observed in the normal brain 2 or 24 h after 20 Gy irradiation were not significantly different from preirradiation values. Also, tumor blood flow appeared to be unchanged at 2 h after 6 Gy irradiation, with a small increase observed at 24 h, unlike the tumor blood flow changes after 20 Gy irradiation. Large and significant changes in vascular parameters were observed hours after 20 Gy irradiation using noninvasive MRI techniques. It is hypothesized that cellular swelling hours after a high dose of radiation, coinciding with vacuolization, led to a decrease in tumor blood flow and v(e). Four hours after radiation exposure, K(trans) increased in concert with an increase in tumor blood flow. Vascular permeability normalized, 24 h after 20 Gy irradiation, as characterized by a decrease in K(trans). Vascular parameters did not change significantly in the normal brain after 20 Gy irradiation or in the tumor-bearing brain after 6 Gy irradiation.

Abstract 2663: Hyperthermia improves Cetuximab accumulation in pancreatic cancer mouse model

Abstract Objective: Histopathological characteristics of pancreatic carcinoma are the presence of abundant stroma that prevent mAb diffusion and consequently hampers mAb from direct attacking cancer cells. With a strong conviction that additional tool that improve mAb penetration and diffusion in dense fibroblastic solid cancer should indispensable for better therapeutic effect, we focused and employed the simple but strongest modalities, heat. Heat might increase tumor blood flow and tumor vessel permeability, leading enhanced accumulation of anticancer mAb. In this study, we aimed the increased accumulation of mAb in mouse pancreatic subcutaneous models and also boosted antitumor effects by applying moderate heat. Methods: Heat generation was completed by hot bathtub method for subcutaneous tumor in nude mice leg. Three human pancreatic cell of different stromal amount were employed (abundant: Capan-1, moderate: BxPC-3, and scant: MIAPaCa-2). At the timing of each tumors growth up to 70mm3, Cetuximab (1 mg/kg) was systematically administrated via caudal vein, subsequently applying heat to tumors for 30 min at three different temperatures of 25°C (control temperature), 37°C (intraabdominal organs), or 41°C (hyperthermia) (n = 5 each). The amount of accumulated Cetuximab were quantified by the fluorescent intensity of Alexa 488 against anti-human IgG at 24 hr, followed by figuring up the intensity of one cancer cell by dividing the total intensity value by the number of a cancer cell nuclei stained with DAPI. Enhanced antitumor effects, among irradiating various heat doses, were evaluated by the tumor volume over time. Results: In Capan-1, the fluorescent intensity per a cancer cell at 25°C, 37°C, 41°C were 675, 1130, 2332 respectively. Similarly, those in BxPC-3 were 673, 1347, 1573, and in MIAPaCa-2 were 1632, 1921, 1949, respectively. In Capan-1 and BxPC-3, the mean tumor growth on day 40 were significantly inhibited at 37°C group (934, 189 mm3), and 41°C group (491, 121 mm3) in compared with 25°C group (1385, 470 mm3) respectively. In MIAPaCa-2, however, that on day 50 was not inhibited at 37 degrees group (109 mm3), and 41 group (151 mm3) as compared with 25 group (123 mm3). Discussion: We demonstrated that hyperthermia actually contributed to measurable add-on antitumor effect for two among three pancreatic cancer models. Intending to provide more add-on effect, we are now evaluating the combined effects of hyperthermia plus applying a cyclic tumor-penetrating peptide (iRGD), which improved anticancer mAb penetration to cancer cells by binding to integrin αv/β3 or β5 and to neuropillin-1 on cancer cells. We suggested that this novel combined strategy would remarkably contribute to the enhanced accumulation of anticancer mAb in tumors and to the enhanced antitumor effects. Citation Format: Ryoichi Miyamoto, Tatsuya Oda, Shinji Hashimoto, Yoshimasa Akashi, Tomohiro Kurokawa, Yuki Inagaki, Nobuhiro Ohkohchi. Hyperthermia improves Cetuximab accumulation in pancreatic cancer mouse model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2663. doi:10.1158/1538-7445.AM2014-2663

A Randomized Phase Ii Study of Paclitaxel-Carboplatin-Bevacizumab (Pcb) with or Without Nitroglycerin Patches (Ntg) in Patients (Pts) with Stage Iv Non-Squamous-Non-Small Cell Lung Cancer (Ns-Nsclc)(Nvalt 12), Impact of Circulating Vascular Endothelial Growth Factor (Vegf) Levels

ABSTRACT Aim: NTG added to standard chemotherapy has been shown to improve clinical outcome. NTG is hypothesized to increase tumor blood flow and may augment drug delivery to the tumor and diminish tumor hypoxia causing a decrease in VEGF. High circulating VEGF is a prognostic factor for unfavourable outcome. We showed that adding NTG to PCB (PCB + N) did not improve progression free survival (PFS), response rate (RR) and overall survival (OS) in pts with stage IV NS-NSCLC (NCT01171170; Dingemans, ASCO 2014). Here we present impact of baseline VEGF on clinical outcome. Methods: In this open-label multicenter phase II trial chemo-naive pts with stage IV NS-NSCLC were randomized 1:1 to PCB or PCB + N. Pts were treated with P 200 mg/m2 day (d) 1-C AUC 6 d1-B 15 mg/kg d1 every 3 weeks (wks) or PCB + NTG 15 mg/24 h for 5 d (d -2 to +3) every cycle for 4 cycles and B + N until progression. The study was powered (80%) to detect a decrease in the hazard of progression of 33% at a = 0.05 with a two-sided log rank test. As pre-planned exploratory analysis baseline, wks 3 and 6 free circulating VEGF levels by ELISA were assessed. Results: 223 pts were randomized; 112 PCB and 111 PCB + N; Median (95% CI) PFS in PCB was 6.8 months (m) (5.6-7.3) and 5.0 m (4.2-5.8) in PCB + N, HR 1.22 (0.91-1.63). OS was 11.6 m (8.7-14) in PCB and 9.5 m (7.8-11.9) in PCB + N, HR 1.12 (0.76-1.67). Baseline median VEGF (n = 178) was 111 pg/ml (inter-quartile range 55-218), equal between 2 arms. High VEGF levels (n = 89) at baseline was associated with worse OS (p = 0.02) and PFS (p = 0.0003). For pts with above median VEGF at baseline, OS and PFS were not different for PCB and PCB + N, for pts with below median VEGF there was a trend for worse PFS HR 1.46 (0.95 – 2.24) and OS HR1.55 (0.97-2.49) in the pts treated with PCB + N. In both arms VEGF became undetectable or very low at 3 and 6 wks. Conclusions: Adding NTG to first line PCB does not improve PFS and OS in pts with stage IV NS-NSCLC. As the mechanism of action of NTG is presumably through the VEGF pathway, decrease of VEGF levels by B may preclude an additional effect of NTG. Disclosure: A.C. Dingemans: advisory board Roche; H.J.M. Groen: advisory board roche E.F. Smit: advisory board roche; J.G. Aerts: advisory board roche. All other authors have declared no conflicts of interest.

A randomized phase II study of paclitaxel-carboplatin-bevacizumab (PCB) with or without nitroglycerin patches (NTG) in patients (pts) with stage IV nonsquamous non-small cell lung cancer (NSCLC): Nvalt 12 (NCT01171170).

8089 Background: NTG increases tumor blood flow and thereby may augment drug delivery to the tumor and inhibits HIF-1a, a major regulator of hypoxia. In mouse models addition of HIF-1α inhibitors t...

Novel nitric oxide generating compound glycidyl nitrate enhances the therapeutic efficacy of chemotherapy and radiotherapy

Selective release of nitric oxide (NO) in tumors could improve the tumor blood flow and drug delivery for chemotherapeutic agents and radiotherapy, thereby increasing the therapeutic index. Glycidyl nitrate (GLYN) is a NO generating small molecule, and has ability to release NO on bioactivation in SCC VII tumor cells. GLYN-induced intracellular NO generation was significantly attenuated by NO scavenger carboxy-PTIO (cPTIO) and NAC. GLYN significantly increases tumor blood flow, but has no effect on the blood flow of normal tissues in tumor-bearing mice. When used with cisplatin, GLYN significantly increased the tumor growth inhibition effect of cisplatin. GLYN also had a modest radiosensitizing effect in vitro and in vivo. GLYN was well tolerated and there were no acute toxicities found at its effective therapeutic doses in preclinical studies. These results suggest that GLYN is a promising new drug for use with chemotherapy and radiotherapy, and provide a compelling rationale for future studies of GLYN and related compounds.

Modulation of Blood Flow, Hypoxia, and Vascular Function in Orthotopic Prostate Tumors During Exercise

Previous studies have hypothesized that tumor blood flow may be elevated or reduced during exercise, which could impact the tumor microenvironment. However, to date technical limitations have precluded the measurement of tumor blood flow during exercise. Using an orthotopic preclinical model of prostate cancer, we tested the hypotheses that during exercise tumors would experience 1) diminished vascular resistance, 2) augmented blood flow, 3) increased numbers of perfused vessels, and 4) decreased tissue hypoxia and, furthermore, that the increased perfusion would be associated with diminished vasoconstriction in prostate tumor arterioles. Dunning R-3327 MatLyLu tumor cells were injected into the ventral prostate of male Copenhagen rats aged 4 to 6 months randomly assigned to tumor-bearing (n = 42) or vehicle control (n = 14) groups. Prostate tumor blood flow, vascular resistance, patent vessel number, and hypoxia were measured in vivo in conscious rats at rest and during treadmill exercise, and vasoconstrictor responsiveness of resistance arterioles was investigated in vitro. During exercise there was a statistically significant increase in tumor blood flow (approximately 200%) and number of patent vessels (rest mean ± standard deviation [SD] = 12.7±1.3; exercise mean ± SD = 14.3±0.6 vessels/field; Student t test two-sided P = .02) and decreased hypoxia compared with measurements made at rest. In tumor arterioles, the maximal constriction elicited by norepinephrine was blunted by approximately 95% vs control prostate vessels. During exercise there is enhanced tumor perfusion and diminished tumor hypoxia due, in part, to a diminished vasoconstriction. The clinical relevance of these findings are that exercise may enhance the delivery of tumor-targeting drugs as well as attenuate the hypoxic microenvironment within a tumor and lead to a less aggressive phenotype.