Combination Treatment of Murine Colon Cancer with Doxorubicin and

Nov 25, 2015 - Master's School of Medical Sciences, Graduate School of ... Treatment with RNPs also improved anticancer efficacy of DOX in the ...
3 downloads 0 Views 2MB Size
Subscriber access provided by TUFTS UNIV

Article

Combination treatment of murine colon cancer with doxorubicin and redox nanoparticles Long Binh Vong, and Yukio Nagasaki Mol. Pharmaceutics, Just Accepted Manuscript • DOI: 10.1021/acs.molpharmaceut.5b00676 • Publication Date (Web): 25 Nov 2015 Downloaded from http://pubs.acs.org on November 30, 2015

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Molecular Pharmaceutics is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

Combination treatment of murine colon cancer with doxorubicin and redox nanoparticles

1 2 3

Long Binh Vong‡ and Yukio Nagasaki*,‡,§,ǁ

4 5

6



7

University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573, Japan

8

§

9

Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan

Department of Materials Science, Graduate School of Pure and Applied Sciences,

Master's School of Medical Sciences, Graduate School of Comprehensive Human

10

ǁ

11

(WPI-MANA), National Institute for Materials Science (NIMS), University of Tsukuba,

12

1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573, Japan

Satellite

Laboratory,

International

Center

for

Materials

1 ACS Paragon Plus Environment

Nanoarchitectonics

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 31

1

*Corresponding author: Prof. Yukio Nagasaki, Department of Materials Science,

2

Graduate School of Pure and Applied Sciences; Master’s School of Medical Sciences,

3

Graduate

4

WPI-MANA, NIMS, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki

5

305-8573, Japan

School

of

Comprehensive

Human

Sciences;

6

7

E-mail address: [email protected]

8

Phone: +81 29-853-5749

9

Fax: +81 29-853-5749

10

11 12

Disclosure of Potential Conflicts of Interest The authors have no competing financial interests to declare.

2 ACS Paragon Plus Environment

Satellite

Laboratory,

Page 3 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

ABSTRACT

2

Conventional chemotherapeutic drugs such as doxorubicin (DOX) are associated with

3

severe adverse effects such as cardiac, hepatic, and gastrointestinal (GI) toxicities.

4

Excessive production of reactive oxygen species (ROS) was reported to be one of the

5

main mechanisms underlying these severe adverse effects. Recently, we have developed

6

2 types of novel redox nanoparticles (RNPs) including pH-sensitive redox nanoparticle

7

(RNPN) and pH-insensitive redox nanoparticle (RNPO), which effectively scavenge

8

overproduced ROS in inflamed and cancerous tissues. In this study, we investigated the

9

effects of these RNPs on DOX-induced adverse effects during cancer chemotherapy.

10

The DOX-induced body weight loss was significantly attenuated in the mice treated

11

with RNPs, particularly pH-insensitive RNPO. We also found that cardiac ROS levels in

12

the DOX-treated mice were dramatically decreased by treatment with RNPs, resulting

13

in the reversal of cardiac damage, as confirmed by both plasma cardiac biomarkers and

14

histological analysis. It was interesting to notice that during co-treatment with DOX

15

and RNPs, the DOX uptake was significantly enhanced in the cancer cells, but not in

16

healthy aortic endothelial cells in vitro. Treatment with RNPs also improved anticancer

17

efficacy of DOX in the colitis-associated colon cancer model mice in vivo. On the basis

18

of these results, a combination of the novel antioxidative nanotherapeutics (RNPs) with

3 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

conventional anticancer drugs seems to be a robust strategy for well-tolerated

2

anticancer therapy.

3

4

KEY WORDS: Redox Nanotherapeutics, Combination Therapy, Drug Resistance,

5

Adverse Effect, Chemotherapy, Reactive Oxygen Species

6

7

INTRODUCTION

8

Doxorubicin (DOX), an anthracycline chemotherapeutic agent, has been used for

9

the treatment of a variety of human cancers for over 30 years. The therapeutic activity

10

of DOX is mediated by its intercalation into DNA, whereby it inhibits topoisomerase II,

11

and prevents DNA and RNA synthesis.1 In addition, DOX generates reactive oxygen

12

species (ROS), inducing apoptosis in cancer cells. 2 Despite the strong anticancer

13

activity and approval by the US Food and Drug Administration, DOX causes severe

14

adverse effects in most of the major organs, especially in the heart; this problem limits

15

the treatment dose.3,4 Increased oxidative stress due to DOX administration is also

16

considered as the classical mechanism of its adverse effects. In addition, repeated

17

administration of DOX may induce drug resistance in cancer cells.5 To alleviate the

18

DOX-induced adverse effects, antioxidants such as resveratrol, curcumin, and

4 ACS Paragon Plus Environment

Page 4 of 31

Page 5 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

N-acetylcysteine have been used as scavengers of ROS upregulated by DOX. 6 – 8

2

Although these low-molecular-weight (LMW) antioxidants have been effective in vitro,

3

they have failed in clinical trials because of low bioavailability, nonspecific distribution,

4

and instability in vivo environments.

5

Recently, we have been developed 2 types of redox nanoparticles (RNPs) -

6

pH-sensitive redox nanoparticle (RNPN) and pH-insensitive redox nanoparticle (RNPO),

7

which effectively scavenge overproduced ROS in inflamed and cancerous tissues.9,10

8

These RNPs were prepared via self-assembly of an amphiphilic block copolymer

9

possessing nitroxide radicals (ROS scavengers) at the side chains of the hydrophobic

10

segment. In previous study, we have confirmed that the RNPs show highly dispersible

11

and biocompatible properties with long half-life in the circulation as compared to the

12

LMW nitroxide radicals.11,12 In particular, the pH-insensitive RNPO shows a longer

13

blood circulation tendency compared with pH-sensitive RNPN due to the stable

14

hydrophobic core of RNPO.11,12 These RNPs have been studied as a possible treatment of

15

the oxidative stress injuries and some cancers. 11 – 17 For example, intravenous

16

administration of the pH-sensitive RNPN works effectively in acute renal injury and

17

cerebral ischemia-reperfusion because it disintegrates in acidic environments of the

18

diseased site via protonation of amino groups in the core of the pH-sensitive RNPN.11,13

5 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

On the other hand, orally administered pH-insensitive RNPO effectively scavenges ROS

2

in the inflamed colon, thus reduce inflammation in the mice with colitis and inhibit the

3

development of colitis-associated colon cancer (CAC) due to the specific accumulation

4

of pH-insensitive RNPO in the colon mucosa without absorption into the bloodstream

5

via the mesentery.15–17

6

In this work, we studied the effects of the pH-sensitive RNPN and pH-insensitive

7

RNPO in combination with DOX treatment in terms of both therapeutic efficacies and

8

DOX-induced adverse effects in vitro and in vivo as compared to control non-nitroxide

9

radical nanoparticle (nRNP).

10

11

EXPERIMENTAL SECTION

12

Preparation and characterization of RNPs and nRNP. The pH-sensitive RNPN

13

and pH-insensitive RNPO were prepared from self-assembling MeO-PEG-b-PMNT and

14

MeO-PEG-b-PMOT block copolymer, respectively, as described previously.11,15

15

Control nanoparticle without nitroxide radical (nRNP) was prepared from

16

MeO-PEG-b-PCMS block copolymer.15 Molecular formula of these block copolymers

17

are shown in Scheme 1. The size of prepared RNPs and nRNP are approximately 40 nm

18

in diameter (Figure 1A) using light dynamic light scattering (DLS) measurements. The

6 ACS Paragon Plus Environment

Page 6 of 31

Page 7 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

pH-sensitive characteristics of RNPs is evaluated using DLS and electron spin resonance

2

measurements as shown in Figure 1B.

3

Cell lines and cultures. The mouse colorectal carcinoma cell (C-26) and normal

4

bovine aortic endothelial cell (BAEC) were purchased from Riken BioResource Center

5

(cat. # RCB2657, Riken Tsukuba Institute, Ibaraki, Japan) and JCRB Cell Bank (cat. #

6

JCRB0099, National Institute of Biomedical Innovation, Osaka, Japan), respectively.

7

These cells were grown in Dulbecco’s modified Eagle’s medium (DMEM;

8

Sigma-Aldrich, St. Louis, MO) containing 10% fetal bovine serum (Sigma-Aldrich, St.

9

Louis, MO), and 1% antibiotics (penicillin/streptomycin/neomycin; Invitrogen,

10

Carlsbad, CA) in a humidified atmosphere containing 5% of CO2 at 37 °C.

11

Cellular uptake of DOX in vitro. Colon cancer C-26 cells and normal BAEC cells

12

were seeded in glass plates at 5 × 104 cells/well. After 2 d of culturing, the DMEM was

13

replaced with fresh media, and the DOX (final concentration 0.5 µM, Wako Pure

14

Chemical Industries, Osaka, Japan) and RNPs solutions (100 µg/mL final

15

concentration) were added to the medium. Hoechst 33342 (Invitrogen) was added 15

16

min before imaging in order to stain the nuclei. The cellular uptake of DOX was

17

analyzed using a fluorescent confocal microscopy system (Zeiss LSM 700, Carl Zeiss

18

Microscopy GmbH, Jena, Germany) with oil immersion at 63× magnification.

7 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

The animals and experimental design of DOX-induced adverse effects. All

2

experiments were performed on 7- to 8-week-old male ICR mice (32–35 g body

3

weight) purchased from Charles River Japan, Inc. (Yokohama, Japan). The mice were

4

maintained at the experimental animal facilities of the University of Tsukuba at

5

controlled temperature (23 ± 1 °C), humidity (50 ± 5%) and lighting (12 h light-dark

6

cycle). The animals were given free access to food and water. All experiments were

7

performed in accordance with the Regulations for Animal Experiments of the

8

University of Tsukuba and the Fundamental Guideline for Proper Conduct of Animal

9

Experiments and Related Activities at Academic Research Institutions under the

10

jurisdiction of the Ministry of Education, Culture, Sports, Science and Technology of

11

Japan (the animal experimental plan number #13-229).

12

The mice were injected intraperitoneally with a single dose DOX (12.5 mg/kg body

13

weight) to induce adverse effects. RNPs and nRNP (100 mg/kg body weight) were

14

injected intravenously 3 times (once a day) starting on day 0 (Figure 2A). After 7 d of

15

treatment, the mice were euthanized to evaluate the efficacy of RNPs against the

16

adverse effects of DOX.

17

Histological assessment. After the mice were sacrificed, the major organs (heart,

18

liver, kidneys, spleen, and small intestine) were weighted and fixed in 4% (v/v)

8 ACS Paragon Plus Environment

Page 8 of 31

Page 9 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

buffered formalin (Wako Pure Chemical Industries, Osaka, Japan) for 1 d and in 70%

2

(v/v) alcohol (Wako Pure Chemical Industries, Osaka, Japan) for 2 d prior to paraffin

3

embedding. Then, 7-µm-thick sections of these tissues were prepared and stained with

4

hematoxylin and eosin (H&E). Histological features were examined under the light

5

microscope.

6

The superoxide assay. The superoxide measurement was evaluated as previous

7

reports.15,18,19 Briefly, the hearts were collected immediately after mice sacrifice and

8

were homogenized in cold PBS. After centrifugation for 15 min at 15,000 rpm 4 °C, the

9

supernatants were collected. To determine superoxide production, supernatants (100

10

µL) were added to well of a 96-well black plate (NUNC) containing 100 µM

11

dihydroethidium (DHE; Wako Pure Chemical Industries, Osaka, Japan), followed by

12

incubation at 37 °C for 30 min. The fluorescence intensity of each well was measured at

13

the excitation wavelength of 530 nm and emission wavelength of 620 nm. DHE alone

14

served as a blank control. The superoxide values, from which the blank value was

15

subtracted, were expressed as intensity per mg of protein. The superoxide level of the

16

control group was standardized to 100%.

17

Induction of CAC model in mice. CAC model mice were induced by

18

intraperitoneal injection of 10 mg/kg body weight of azoxymethane (AOM,

9 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

Sigma-Aldrich, St. Louis, MO) followed by 2 cycles of 7 d of 3% dextran sodium

2

sulfate (DSS, 5,000 Daltons; Wako Pure Chemical Industries, Osaka, Japan) in the

3

drinking water. A video endoscopy system (TESALA AVS, Olympus, Tokyo, Japan)

4

and a previously described tumor scoring system were used to evaluate the tumor

5

development in mouse colons.20 DOX (5 mg/kg) was intravenously injected to mice

6

once/week, while RNPO (2.5 mg/mL) was given to mice in free drinking water from

7

day 35, and the treatments were stopped on day 70.

8

Statistical analysis. All data were expressed as mean ± standard deviation (SD) or

9

standard error of the mean (SEM). Differences between groups were examined for

10

statistical significance using Student’s t test and one-way analysis of variance, followed

11

by Turkey’s post hoc test (SPSS software; IBM Corp, Armonk, NY). Differences with a

12

P value < 0.05 were considered significant in all statistical tests.

13

RESULTS AND DISCUSSION

14

RNPs suppressed DOX-induced adverse effects. It is generally known that DOX

15

administration causes severe toxicities to many organs due to ROS generation. In our

16

previous studies, RNPs exhibited a high ROS scavenging activity both in vitro and in

17

vivo conditions.11,21,22 In order to investigate the effects of RNPs on DOX toxicities, 10 ACS Paragon Plus Environment

Page 10 of 31

Page 11 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

RNPs were intravenously injected to DOX-treated mice (Figure 2A). As shown in

2

Figure 2B, the DOX-treated mice exhibited a significant body weight loss. DOX

3

administration also caused a significant weight loss of internal organs in comparison

4

with untreated mice (Table 1). On the other hand, mice co-treated with DOX and RNPs,

5

particularly with the pH-insensitive RNPO, showed remarkable attenuation of the

6

weight loss of the entire body and of internal organs compared to the DOX-treated mice.

7

DOX treatment is well known to cause cardiac and hepatic adverse effects, which raise

8

the activity of several plasma enzymes such as lactate dehydrogenase (LDH), creatine

9

phosphokinase (CPK), aspartate aminotransferase (AST), and alanine aminotransferase

10

(ALT) as compared to healthy mice. As shown in Table 2, levels of these enzymes were

11

significantly lower in the combination with DOX and RNPs-treated mice.

12

Furthermore, the ROS levels in the heart were significantly increased in the

13

DOX-treated mice, indicating that DOX treatment caused the oxidative stress in the

14

heart and resulted in the cardiac toxicity. In contrast, the cardiac ROS levels were

15

significantly decreased by co-treatment with RNPs (Figure 2C), indicating the ROS

16

scavenging capacity of systemically administered RNPs. This is again that

17

pH-insensitive RNPO showed higher performance compared with pH-sensitive RNPN.

18

In histological analyses, we observed the disorganized myofibrils and vacuolization of

11 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

the cytoplasm in heart tissues of the DOX-treated mice (Figure 3A). DOX treatment

2

also caused the loss of cellular boundaries and hepatic tissue structural pattern in liver

3

tissue, as shown in Figure 3B. In contrast, the mice with combination treatments with

4

RNPs showed a normal morphology with well-preserved cytoplasm in heart and liver

5

tissues, which are similar to healthy control mice (Figure 3A and B). It was also

6

reported that DOX treatment causes damage in intestinal tissues.23,24 As can be seen in

7

Figure 4, the damage of intestinal tissues was reversed by intravenous administration of

8

RNPs. These data clearly indicate that administration of RNPs effectively ameliorated

9

DOX-induced cardiac, hepatic, and intestinal adverse effects in mice by scavenging

10

overproduced ROS. DOX has been postulated to cause cardiac toxicity through

11

activation of p53 protein and overproduction of ROS in cardiomyocytes, endothelial

12

cells, and other non-cancerous cells.25,26 Numerous ROS scavengers have failed to

13

prevent the toxicities of DOX in the clinical trials because of low biocompatibility and

14

low stability in the blood circulation after administration. In addition, LMW

15

antioxidants are internalized by healthy cells and interfere with the important redox

16

reactions such as electron transport chain, which stops respiratory system and causes

17

severe adverse effects. This drawback prevents effective level of dose for LMW

18

antioxidants. We have already shown that RNPs prevents internalization to healthy cells

12 ACS Paragon Plus Environment

Page 12 of 31

Page 13 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

due to their nanoparticle size and large molecular weight, which do not disturb the

2

important redox reactions in healthy cells.27

3

It should be noted that the effect of the pH-insensitive RNPO is more clearly

4

observed as compared to the pH-sensitive RNPN. We previously reported that the

5

pH-insensitive RNPO exhibited a much longer blood circulation than pH-sensitive

6

RNPN, which might enhance its ROS scavenging efficiency to suppress the adverse

7

effects of DOX to mice. This finding also suggests that the short half-life of LMW

8

antioxidants in the bloodstream is one of the reasons for their weak effect on

9

ROS-induced adverse effects. In addition, nitroxide radicals in the core of RNPs are

10

covalently conjugated to the polymer chains, and this arrangement prevents the leakage

11

and internalization of free active ingredients into healthy cells, suggesting low adverse

12

effects of these nanotherapeutics.

13

RNPs enhanced uptake of DOX in cancer cells in vitro. As stated above, one of

14

the mechanisms underlying the antitumor effects of DOX is its intercalation into DNA

15

in the nucleus. Thus, it was important to confirm cellular internalization tendency of

16

DOX along with RNPs. The cellular viability and DOX uptake were analyzed during

17

co-treatment of colon cancer cells (C-26) and normal endothelial cells (BAEC) with

18

DOX and RNPs. As shown in Figure 5A, RNPs alone did not cause any cytotoxicity in

13 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

both cell types under the present conditions. It is also obvious that the combination

2

treatment of RNPs with DOX significantly enhanced the anticancer activity of DOX

3

toward C-26 cells compared to DOX treatment alone (Figure 5A). Conversely, it is

4

rather surprising for us that cytotoxicity of DOX to normal BAEC cells was suppressed

5

by the combination treatment of DOX with RNPs (Figure 5B). One of the main

6

reactions that ROS participate in a live organism is oxidation of lipids in the cellular

7

membrane, which causes an increase in nonspecific permeation of substances. The

8

strong antioxidative effect of RNPs may attenuate such cellular membrane damages by

9

oxidative stress.

10

On the other hand, we found that the uptake of DOX in C-26 was significantly

11

improved by co-treatment with RNPs (Figure 5C and D). It was reported that excessive

12

generation of ROS upregulates the expression of P-glycoprotein (Pgp), a

13

transmembrane protein capable of effluxing many chemotherapeutic drugs out of

14

cancer cells, which is one of the major mechanisms of drug resistance phenomenon,

15

resulting in low uptake of chemotherapeutic drug in cancer cells. 28 Antioxidant

16

N-acetylcysteine inhibits the expression and activity of Pgp induced by high production

17

of ROS.29 Additionally, we found that the Pgp level was decreased by incubation of a

18

Pgp-overexpressing human epidermoid KB carcinoma cell line with RNPs (data not

14 ACS Paragon Plus Environment

Page 14 of 31

Page 15 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

shown). The results suggested that RNPs enhanced the uptake of DOX in C-26 colon

2

cancer cells by suppressing the expression of Pgp during DOX treatment. On the basis

3

of the observed effects of combination treatments, RNPs are expected to improve

4

therapeutic efficacy and suppress adverse effects of DOX.

5

RNPs enhanced chemotherapeutic effects of DOX in vivo. Since RNPs

6

effectively suppressed the DOX-induced adverse effects and enhanced DOX uptake in

7

cancer cells, the combination of DOX with RNPs is anticipated to be an effective

8

treatment for cancer therapy. Accordingly, we next examined the efficacy of the

9

combination treatment of RNPs and DOX in vivo on a mouse model of CAC, which

10

was induced by co-treatment with AOM and DSS. We have previously reported that

11

orally administered pH-insensitive RNPO does not get absorbed into bloodstream but

12

highly accumulates in tumor tissues in the colon.17 Thus, it is interesting to investigate

13

that oral administration of RNPO works similarly to that of intravenous administration

14

in combination treatment with intravenously injected DOX. As shown in Figure 6A and

15

B, DOX alone mildly suppressed tumor growth, whereas the combination treatment

16

significantly inhibited the tumor development in the colon of mice as compared to the

17

control group and DOX-treated groups. In particularly, the survival and the lifespan

18

were remarkably improved by the combination treatment compared to the treatment

15 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

with DOX only (Figure 6C). It should be noted that the lifespan of the DOX alone

2

group of mice did not increase significantly, which is interpreted by the severe adverse

3

effect to normal organs though tumor growth was suppressed as anticipated. In contrast,

4

the combination treatment with RNPO significantly improved the chemotherapeutic

5

efficiency of DOX against colon cancer development and improved the lifespan of mice,

6

probably due to the effective suppression of the adverse effects. In clinical practice, the

7

cumulative dose of DOX is limited due to its severe adverse effects, resulting in a low

8

effect of chemotherapy. The results obtained in this study indicated that administration

9

of RNPs significantly suppressed DOX-induced adverse effects in mice including

10

cardiac, hepatic, and intestinal toxicities. Therefore, the high doses of DOX can be

11

applicable in mice administrating with RNPs to achieve an effective cancer therapy

12

with low adverse effects.

13

14

CONCLUSION

15

In this study, we tested a combination treatment of novel ROS scavenging

16

nanoparticles, RNPs, with conventional chemotherapy DOX against colon cancer.

17

Administration of RNPs significantly suppressed the severe adverse effects of DOX

18

both in vivo and in vitro. In addition, RNPs enhanced the uptake of DOX in the cancer

16 ACS Paragon Plus Environment

Page 16 of 31

Page 17 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

cells, not in healthy endothelial cells, which significantly improved chemotherapeutic

2

efficacy of DOX. The combination treatment was effective to inhibit colon cancer and

3

prolonged the lifespan with low adverse effects. Taken together, our results indicate that

4

the combination of antioxidative nanotherapeutics with conventional chemotherapy is a

5

promising strategy for well-tolerated anticancer therapy.

6

ACKNOWLEDGEMENTS

7

A part of this work was supported by a Grant-in-Aid for Scientific Research S

8

(25220203) and the World Premier International Research Center Initiative (WPI

9

Initiative) on Materials Nanoarchitectonics of the Ministry of Education, Culture,

10

Sports, Science and Technology (MEXT) of Japan. One of the authors, L.B. Vong,

11

would like to express his sincere appreciation for the Research Fellowship of the Japan

12

Society for the Promotion of Science (JSPS) for Young Scientists.

17 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

Figure Captions:

2

Scheme 1

3 4

Scheme 1: Molecular formula of block copolymers and illustration of redox

5

nanoparticles (RNPs) and control nanoparticle without nitroxide radical (nRNP) used in

6

this study.

18 ACS Paragon Plus Environment

Page 18 of 31

Page 19 of 31

1

Figure 1 A

B

RNPO

RNPN

Light scattering intensity (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

nRNP

120 100 80 60 40 RNP O 20

RNP N

0 1

2

10 100 1000 1 Diameter (nm)

10

100

Diameter (nm)

1000 1

10

100

1000

3

4

Diameter (nm)

5

6 pH

7

8

9

3

Figure 1: Characterization of nanoparticles. (A) The size of RNPO, RNPN, and CNP

4

are determined by dynamic light scattering (DLS, Zetasizer Nano ZS). (B) pH-sensitive

5

characteristics of RNPN and RNPO under different pH value. The light scattering

6

intensity is measured by DLS and normalization (100%) is expressed as the value

7

relative to that at pH 7.5. The electron spin resonance (ESR) is used to confirm

8

morphology of RNPs. Black ESR spectrum indicates the micelle structure of RNPO and

9

RNPN at pH 7.5. Green ESR spectrum indicates the micelle structure of RNPO at pH 2.5,

10

and red ESR spectrum indicates the disintegration of RNPN at pH 2.5.

11

19 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

Figure 2

2

3

Figure 2. RNPs suppress DOX-induced adverse effects in vivo. (A) The scheme of

4

administration of the RNPs and DOX administration to mice. (B) Body weight changes

5

during treatment with RNPs and DOX. (C) Superoxide production in the heart after 7 d

6

of treatment with RNPs and DOX. The data are expressed as mean ± SEM, *P < 0.05

7

compared to the DOX group, n = 6.

8

9

20 ACS Paragon Plus Environment

Page 20 of 31

Page 21 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

Figure 3

2

3

Figure 3. Administration of RNPs reverses cardiac and hepatic histological toxicity

4

induced by DOX. After 7 d of treatment, the heart and liver were collected, and

5

7-µm-thick sections were prepared. The sections were stained by hematoxylin and eosin

6

(H&E) and assessed histologically. (A) Histological analysis of the heart. (B)

7

Histological analysis of the liver. Representative sections are shown for n = 3 mice. The

8

scale bars are 50 µm.

9

21 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

Figure 4

2

3

Figure 4. Administration of RNPs attenuates the intestinal toxicity induced by

4

DOX. Intestinal histological analysis of mice after 7 d of treatment with DOX and

5

RNPs. Sections were stained by H&E, and assessed histologically. Representative

6

sections are shown for n = 3 mice. The scale bars are 500 µm.

7

22 ACS Paragon Plus Environment

Page 22 of 31

Page 23 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

Figure 5

2

3

Figure 5. Effects of RNPs on DOX-treated colon cancer C-26 cells and normal

4

aortic endothelial BAEC cells in vitro. (A and B) Cellular viability of C-26 cells and

5

BAEC cells, respectively, after 1 d of treatment with RNPs (0.5 mM) and DOX (0.5

6

µM) according to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide

7

(MTT) assay. The data are expressed as mean ± SD, *P < 0.05, n = 6. (C and D) Uptake

8

of DOX in colon cancer C-26 cells. DOX (red) and nuclei (blue, stained with Hoechst

9

33342) were analyzed using a fluorescent confocal microscope system (Zeiss LSM

10

700) with oil immersion at 63× magnification. The scale bars are 20 µm. The data are

11

expressed as mean ± SEM, *P < 0.05 compared to the DOX group, n = 4 to 5.

23 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1

Page 24 of 31

Figure 6

2

3

Figure 6. Combination effects of DOX and RNPO on AOM/DSS-induced CAC in

4

mice. DOX (5 mg/kg) was intravenously injected to mice once a week, while RNPO

5

(2.5 mg/mL) was administered to mice with freely drinking water starting on day 35,

6

and the treatments were stopped on day 70 (since the beginning of the AOM/DSS

7

treatment). (A) The endoscopic imaging of mice on day 140 of treatment. (B) Colonic

8

tumor development profile. The data are expressed as mean ± SEM, *P < 0.05

9

compared to the DOX group, n = 6 mice. (C) The survival rate of the mice after

10

treatment with DOX and RNPO, n = 6 mice.

11

Table 1. Organ weight (g) after 7 d of treatment with DOX and RNPs

12

Control

DOX

DOX + nRNP

DOX + RNPN

DOX + RNPO

Liver

2.152 ± 0.164 *

1.312 ± 0.090

1.365 ± 0.139

1.652 ± 0.225 *

1.767 ± 0.316 *

Heart

0.216 ± 0.020 *

0.131 ± 0.012

0.136 ± 0.0489

0.136 ± 0.010

0.174 ± 0.025 *

Spleen

0.126 ± 0.005 *

0.057 ± 0.006

0.0676 ± 0.030

0.069 ± 0.018 *

0.075 ± 0.007 *

Kidney

0.338 ± 0.021 *

0.190 ± 0.020

0.196 ± 0.069

0.215 ± 0.023 *

0.251 ± 0.028 *

* P < 0.05 compared to the DOX group, the data are expressed as mean ± SEM, n = 6. 24 ACS Paragon Plus Environment

Page 25 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

1

Table 2. Effects of RNPs on activities (U/L) of plasma LDH, CPK, AST and ALT

2

enzyme in DOX-treated mice.

Control

DOX

DOX+nRNP

DOX+RNPN

DOX+RNPO

LDH

463.5 ± 45.75 *

732.17 ± 70.96

744.67 ± 78.74

764.67 ± 44.98

476.57 ± 27.22 *

CPK

461.33 ± 54.10 *

1009.17 ± 196.38

987.83 ± 210.57

467.83 ± 118.60 *

431.86 ± 55.17 *

AST

76.00 ± 5.11 *

185.50 ± 38.12

211.50 ± 61.07

159.33 ± 39.41

84.00 ± 14.06 *

ALT

24.83 ± 1.45*

76.33 ± 19.90

88.00 ± 23.26

41.40 ± 6.71 *

24.00 ± 3.77 *

3

* P < 0.05 compared to the DOX group, the data are expressed as mean ± SEM, n = 6.

4

References ( 1) Tacar O.; Sriamornsak P.; Dass C.R. Doxorubicin: an on update anticancer molecular action, toxicity and novel drug delivery systems. J. Pharm. Pharmacol. 2013, 65 (2), 157–70. (2) Kim S. Y.; Kim S. J.; Kim B. J.; Rah S. Y.; Chung S. M.; Im M. J.; Kim U. H. Doxorubicin-induced reactive oxygen species generation and intracellular Ca2+ increase are reciprocally modulated in rat cardiomyocytes. Exp. Mol. Med. 2006, 38 (5), 535–45. (3) Shi Y.; Moon M.; Dawood S.; McManus B.; Liu P. P. Mechanisms and management of doxorubicin cardiotoxicity. Herz. 2011, 36 (4), 296–305. (4) Zhang S.; Liu X.; Bawa-Khalfe T.; Lu L. S.; Lyu Y. L.; Liu L. F.; Yeh E. T. Identification of the molecular basis of doxorubicin-induced cardiotoxicity. Nat. Med.

25 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

2012, 18 (11), 1639–42. (5) Szakács G.; Paterson J. K.; Ludwig J. A.; Booth-Genthe C.; Gottesman M. M. Targeting multidrug resistance in cancer. Nat. Rev. Drug Discov. 2006, 5, 219–34. (6) Notarbartolo M.; Poma P.; Perri D.; Dusonchet L.; Cervello M.; D'Alessandro N. Antitumor effects of curcumin, alone or in combination with cisplatin or doxorubicin, on human hepatic cancer cells. Analysis of their possible relationship to changes in NF-kB activation levels and in IAP gene expression. Cancer Lett. 2005, 224 (1), 53–65. (7) Doroshow J. H.; Locker G. Y.; Ifrim I.; Myers C. E. Prevention of doxorubicin cardiac toxicity in the mouse by N-acetylcysteine. J. Clin. Invest. 1981, 68 (4), 1053– 64. (8) Danz E. D.; Skramsted J.; Henry N.; Bennett J. A.; Keller R. S. Resveratrol prevents doxorubicin cardiotoxicity through mitochondrial stabilization and the Sirt1 pathway. Free Radic. Biol. Med. 2009, 46, 1589–97. (9) Yoshitomi T.; Miyamoto D.; Nagasaki Y. Design of core-shell-type nanoparticles carrying stable radicals in the core. Biomacromolecules 2009, 10 (3), 596–601. (10) Yoshitomi T.; Suzuki R.; Mamiya T.; Matsui H.; Hirayama A.; Nagasaki Y. pH-sensitive radical-containing-nanoparticle (RNP) for the L-band-EPR imaging of low pH circumstances. Bioconjug. Chem. 2009, 20 (9), 1792–8. (11) Yoshitomi T.; Hirayama A.; Nagasaki Y. The ROS scavenging and renal protective

26 ACS Paragon Plus Environment

Page 26 of 31

Page 27 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

effects of pH-responsive nitroxide radical-containing nanoparticles. Biomaterials 2011, 32, 8021–8. (12) Chonpathompikunlert P.; Fan C. H.; Ozaki Y.; Yoshitomi T.; Yeh C. K.; Nagasaki Y. Redox nanoparticle treatment protects against neurological deficit in focused ultrasound-induced intracerebral hemorrhage. Nanomedicine 2012, 7 (7), 1029–43. (13) Marushima A.; Tsurusima H.; Yoshitomi T.; Toh K.; Hirayama A.; Nagasaki Y.; Matsumura A. Newly synthesized radical-containing nanoparticles (RNP) enhance neuroprotection after cerebral ischemia-reperfusion injury. Neurosurgery 2011, 68 (5), 1418–26. (14)Yoshitomi T.; Ozaki Y.; Thangavel S.; Nagasaki Y. Redox nanoparticle therapeutics to cancer--increase in therapeutic effect of doxorubicin, suppressing its adverse effect. J. Control Release 2013, 172 (1), 137–43. (15) Vong L. B.; Tomita T.; Yoshitomi T.; Matsui H.; Nagasaki Y. An orally administered redox nanoparticle that accumulates in the colonic mucosa and reduces colitis in mice. Gastroenterology 2012, 143 (4), 1027–36. (16) Vong L. B.; Mo J.; Abrahamsson B.; Nagasaki Y. Specific accumulation of orally administered redox nanotherapeutics in the inflamed colon reducing inflammation with dose-response efficacy. J. Controlled Release 2015, 210, 19–25. (17) Vong L. B.; Yoshitomi T.; Matsui H.; Nagasaki Y. Development of an oral nanotherapeutics using redox nanoparticles for treatment of colitis-associated colon cancer. Biomaterials 2015, 55, 54–63. (18) Kim J; Jung K.J.; Park K.M. Reactive oxygen species differently regulate renal 27 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

tubular epithelial and interstitial cell proliferation after ischemia and reperfusion injury. Am. J. Physiol. Renal Physiol. 2010, 298, F1118–29. (19) Wang X.; Fang H.; Huang Z.; Shang W.; Hou T.; Cheng A.; Cheng H. Imaging ROS signaling in cells and animals. J. Mol. Med. (Berl) 2013, 91(8), 917–27.

(20) Becker C.; Fantini M. C.; Neurath M. F. High resolution colonoscopy in live mice. Nat. Protoc. 2006, 1, 2900–4. ( 21 ) Yoshitomi T.; Yamaguchi Y.; Kikuchi A.; Nagasaki Y. Creation of a blood-compatible surface: A novel strategy for suppressing blood activation and coagulation using a nitroxide radical-containing polymer with reactive oxygen species scavenging activity. Acta Biomater. 2012, 8 (3), 1323–9. (22) Yoshitomi T.; Nagasaki Y. Design and preparation of a nanoprobe for imaging inflammation sites. Biointerphases 2012, 7, 7.

28 ACS Paragon Plus Environment

Page 28 of 31

Page 29 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

(23) Kaczmarek A.; Brinkman B. M.; Heyndrickx L.; Vandenabeele P.; Krysko D. V. Severity of doxorubicin-induced small intestinal mucositis is regulated by the TLR-2 and TLR-9 pathways. J. Pathol. 2012, 226 (4), 598–608. ( 24 ) Morelli D.; Ménard S.; Colnaghi M. I.; Balsari A. Oral administration of anti-doxorubicin monoclonal antibody prevents chemotherapy-induced gastrointestinal toxicity in mice. Cancer Res. 1996, 56 (9), 2082–5. (25) Wang S.; Konorev EA.; Kotamraju S.; Joseph J.; Kalivendi S.; Kalyanaraman B. Doxorubicin induces apoptosis in normal and tumor cells via distinctly different mechanisms. intermediacy of H2O2- and p53-dependent pathways. J. Biol. Chem. 2004, 279 (24), 25535–43. (26) Singal P. K.; Iliskovic N. Doxorubicin-induced cardiomyopathy. N. Engl. J. Med. 1998, 339, 900 – 5. ( 27 ) Shimizu M.; Yoshitomi T.; Nagasaki Y. The behavior of ROS-scavenging nanoparticles in blood. J. Clin. Biochem. Nutr. 2014, 54 (3), 166–73. (28) Chen J. Reactive Oxygen Species and Drug Resistance in Cancer Chemotherapy. Austin J. Clin. Pathol. 2014, 1 (4), 1017–24.

29 ACS Paragon Plus Environment

Molecular Pharmaceutics

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(29) Hong H.; Lu Y.; Ji Z. N.; Liu G. Q. Up-regulation of P-glycoprotein expression by glutathione depletion-induced oxidative stress in rat brain microvessel endothelial cells, J. Neurochem. 2006, 98 (5), 1465–73.

30 ACS Paragon Plus Environment

Page 30 of 31

Page 31 of 31

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Molecular Pharmaceutics

Administration of redox nanoparticles (RNPs) suppresses severe side effects of doxorubicin (DOX) by scavenging overproduced reactive oxygen species. RNPs significantly enhance the uptake of DOX in cancer cells, resulting in effective therapy against colon cancer 182x107mm (300 x 300 DPI)

ACS Paragon Plus Environment