Phospho-Sulindac (OXT-328), a Novel Sulindac Derivative, Is Safe and Effective in Colon Cancer Prevention in Mice

doi:10.1053/j.gastro.2010.06.044

Gastroenterology

Volume 139, Issue 4, October 2010, Pages 1320-1332

https://doi.org/10.1053/j.gastro.2010.06.044 Get rights and content

Background & Aims

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective cancer chemopreventive agents. However, chronic administration of NSAIDs is associated with significant side effects, mainly of the gastrointestinal tract. Given these limitations, we synthesized phospho-sulindac (P-S; OXT-328), a novel sulindac derivative.

Methods

Here, we evaluated the safety and efficacy of P-S in preclinical models, including its mechanism of action with human colon cancer cell (HCCC) lines and animal tumor models.

Results

(1) Compared with sulindac, P-S is much more potent in inhibiting the growth of cultured HCCCs and more efficacious in preventing the growth of HT-29 xenografts in nude mice. P-S also prevents the growth of intestinal tumors in Apc/Min mice. (2) In combination with difluoromethylornithine (DFMO), P-S reduced tumor multiplicity in Apc/Min mice by 90%. (3) P-S is much safer than sulindac as evidenced by its in vitro toxicologic evaluation and animal toxicity studies. Mechanistically, P-S increases the intracellular levels of reactive oxygen and nitrogen species, which are key early mediators of its chemopreventive effect. Moreover, P-S induces spermidine/spermine N¹-acetyltransferase enzymatic activity, and together with DFMO it reduces polyamine levels in vitro and in vivo.

Conclusions

P-S displays considerable safety and efficacy, two pharmacologic properties that are essential for a potential cancer chemopreventive agent, and thus merits further evaluation.

Section snippets

Reagents and Cell Culture

P-S was synthesized as reported.⁶ Sulindac, A23187, and N-acetyl-L-cysteine (NAC) were from Sigma. Human colon cancer cell lines and the normal human colon cell line NCM460 were grown as monolayer as suggested by American Type Culture Collection (Manassas, VA). Cell growth was determined with the MTT assay (Promega, Madison, WI) following the manufacturer's instructions.⁷ Cells were treated with P-S with or without DFMO for ≤48 hours. Cell proliferation was assayed by 5-bromo-2′-deoxyuridine

P-S Inhibits the Growth of Cultured Colon Cancer Cells Through a Strong Cytokinetic Effect

To study the effect of P-S and sulindac on cell growth, we determined in various human colon cancer cells the 24-hour concentration values that inhibit their growth by 50% (IC₅₀; Figure 1B). The IC₅₀ values of P-S varied little among these cell lines (70–79.3 μmol/L), whereas those of sulindac were consistently >1000 μmol/L, indicating a potency enhancement of >14.2-fold.

We then elucidated the underlying cytokinetic effect of P-S on HT-29 and SW480 cells. P-S markedly reduced

Discussion

The successful pharmacologic agent against cancer must be effective and must lack significant side effects. Here, we demonstrate that P-S seems to meet both these requirements, markedly inhibiting intestinal tumors by itself and to a greater extent in combination with DFMO and appearing much safer than sulindac in preclinical studies.

P-S is a potent inhibitor of colon cancer cell lines (>14-fold more potent than sulindac) and exerts a profound inhibitory effect in preclinical models of colon

References (17)

N. Seiler et al.
High-performance liquid chromatographic procedure for the simultaneous determination of the natural polyamines and their monoacetyl derivatives
J Chromatogr
(1980)
S. Chopra et al.
Induction of spermidine/spermine N1-acetyltransferase in human cancer cells in response to increased production of reactive oxygen species
Biochem Pharmacol
(1998)
N. Babbar et al.
Cyclooxygenase-independent induction of apoptosis by sulindac sulfone is mediated by polyamines in colon cancer
J Biol Chem
(2003)
Y. Beazer-Barclay et al.
Sulindac suppresses tumorigenesis in the Min mouse
Carcinogenesis
(1996)
E.W. Gerner et al.
Polyamines and cancer: old molecules, new understanding
Nat Rev Cancer
(2004)
F.L. Meyskens et al.
Difluoromethylornithine plus sulindac for the prevention of sporadic colorectal adenomas: a randomized placebo-controlled, double-blind trial
Cancer Prev Res (Phila Pa)
(2008)
J. Roberts et al.
Analgesic-antipyretic and antiinflammatory agents and drugs employed in the treatment gout
G.A. Piazza et al.
A novel sulindac derivative that does not inhibit cyclooxygenases but potently inhibits colon tumor cell growth and induces apoptosis with antitumor activity
Cancer Prev Res (Phila Pa)
(2009)

There are more references available in the full text version of this article.

Cited by (51)

Phospho-Aspirin (MDC-22) inhibits pancreatic cancer growth in patient-derived tumor xenografts and KPC mice by targeting EGFR: Enhanced efficacy in combination with irinotecan
2022, Neoplasia (United States)
Citation Excerpt :
We have previously identified MDC-22 (Fig. 1A) as a potent EGFR inhibitor [13,14], and documented that MDC-22 possesses strong chemopreventive properties in PC [14]. This novel agent has been synthesized based on a general approach where a specific chemical modification of known drugs enhances their desired anticancer properties, mainly their safety and efficacy [15,16]. In the present study, we examined the therapeutic efficacy of MDC-22 in two clinically relevant models of PC.
Novel therapeutic strategies are needed in the fight against pancreatic cancer. We have previously documented the chemopreventive effect of MDC-22 in preclinical models of pancreatic cancer. In the present work, we examined the therapeutic effects of MDC-22 in patient-derived tumor xenografts (PDTXs) and in LSL-Kras^G12D/+, LSL-Trp53^R172H/+, Pdx1-Cre (KPC) genetically engineered mice, two complementary and clinically relevant animal models of pancreatic cancer. In addition, we evaluated whether MDC-22 could synergize with current chemotherapeutic drugs used in the clinic. MDC-22 reduced the growth of various human pancreatic cancer cell lines in a concentration-dependent manner. In vivo, MDC-22 strongly reduced patient-derived pancreatic tumor xenograft growth by 50%, and extended survival of LSL-Kras^G12D/+; LSL-Trp53^R172H/+; Pdx1-Cre (KPC) mice by over a month (5.3 months versus 7.0 months). In both models, MDC-22 inhibited EGFR activation and its downstream signals, including ERK and FAK phosphorylation. In human pancreatic cancer cell lines, MDC-22 enhanced the growth inhibitory effect of irinotecan, and to a lesser degree those of gemcitabine and nab-paclitaxel. Normal human pancreatic epithelial cells were more resistant to the cytotoxic effects of, both, MDC-22 alone or in combination with irinotecan, indicating selectivity. Furthermore, MDC-22 enhanced irinotecan's effect on cell migration, in part, by inhibiting EGFR/FAK signaling. Collectively, our results indicate that MDC-22 is an effective anticancer drug in preclinical models of pancreatic cancer, and suggest that MDC-22 plus irinotecan as drug combination strategy for pancreatic cancer treatment, which warrants further evaluation.
The ocular pharmacokinetics and biodistribution of phospho-sulindac (OXT-328) formulated in nanoparticles: Enhanced and targeted tissue drug delivery
2019, International Journal of Pharmaceutics
Citation Excerpt :
Phospho-sulindac (PS, OXT-328) is a novel agent with anticancer and anti-inflammatory properties. The anticancer properties of PS encompass a variety of tumors, including colon, lung, non-melanoma skin cancer and pancreatic cancer (Cheng et al., 2018; Cheng et al., 2012, 2013; Mackenzie et al., 2010; Murray et al., 2014; Zhu et al., 2012). The anti-inflammatory efficacy of PS has been demonstrated in an animal model of arthritis, in which it was applied topically formulated in a hydrogel and reversed large joint arthritis (Mattheolabakis et al., 2013).
We studied the pharmacokinetics, biodistribution and metabolism of phospho-sulindac (PS), a novel agent efficacious in the treatment of dry eye, formulated in nanoparticles (PS-NPs) following its topical administration to the eye of New Zealand White rabbits. The nanoparticles were spherical with effective diameter = 108.9 ± 41.7 nm, zeta potential = −21.70 ± 3.78 mV, drug loading = 7%, and entrapment efficiency = 46.4%. Of the total PS delivered topically to the eye, >95% was retained in the anterior segment, predominantly in the cornea (C_max = 101.3 μM; T_max = 1 h; T_1/2 = 2.6 h; area AUC_0–16h = 164.4 µM·h) and conjunctiva (C_max = 89.4 μM; T_max = 0.25 h; T_1/2 = 3.1 h; AUC_0–16h = 63.5 µM·h), the tissues most affected by dry eye disease. No PS or its metabolites were detected in the systemic circulation. PS was metabolized to PS sulfide and PS sulfone; all three molecules were hydrolyzed to sulindac, which was converted to sulindac sulfide and sulindac sulfone. A solution formulation of PS provided lower PS levels in ocular tissues but higher levels of PS metabolites, compared to PS-NPs. Therefore, NPs represent an effective formulation for the topical ocular administration of PS for anterior segment diseases, such as dry eye disease.
Phosphosulindac is efficacious in an improved concanavalin A-based rabbit model of chronic dry eye disease
2018, Translational Research
Citation Excerpt :
Because the ideal treatment for DED is not currently available, the development of new treatments for DED is an active area of research. Phosphosulindac (PS, OXT-328) is a small molecule whose salient features, based on extensive preclinical work, are its pharmacologic efficacy and outstanding safety.26-28 PS is not a prodrug of the NSAID sulindac as the entire PS molecule is required for its pharmacologic activity.29,30
Dry eye disease (DED) currently has no satisfactory treatment partly because of the lack of informative animal models. We evaluated the anti-inflammatory phosphosulindac (PS) for the treatment of DED using a new rabbit model of DED based on the concanavalin A (Con A) acute DED model: we injected all lacrimal glands with Con A weekly under ultrasound guidance, which prolonged DED to >3 weeks, and thoroughly assessed efficacy with tear break-up time (TBUT), tear osmolarity, Schirmer test, and tear lactoferrin levels. Rabbits with DED (n = 8–10 eyes per group) were treated topically with PS or vehicle 3×/day for 21days. PS restored TBUT, tear osmolarity, and lactoferrin levels (P < 0.0001–0.04) to normal but did not significantly improve the results of the Schirmer test. PS showed no side effects and was much more efficacious than cyclosporine or lifitegrast. In the cornea, PS suppressed the activation of nuclear factor kappa-B, the levels of transforming growth factor beta, interleukin-1 beta, interleukin-6, and interleukin-8, and the levels of matrix metalloproteinase (MMP)-1 and MMP-9, and MMP activity. Levels of prostaglandin E₂ (PGE₂) in tears and cornea were preserved in PS-treated rabbits. Ketorolac and diclofenac, two ophthalmic NSAIDs causing corneal melt, nearly completely suppressed PGE₂ levels but had no effect on MMPs. The effects of PS on PGE₂ and MMPs likely account for its apparent ocular safety. Our results establish an animal model for acute and chronic DED suitable for drug efficacy studies and indicate that PS merits evaluation for DED.
A novel ibuprofen derivative with anti-lung cancer properties: Synthesis, formulation, pharmacokinetic and efficacy studies
2014, International Journal of Pharmaceutics
Citation Excerpt :
This effect was noted both in cultured cells, by using the ROS probe DCF-DA, and in animals, by assaying urinary levels of 8-iso-PGF2α, a widely used marker of oxidative stress in vivo (Milne et al., 2005). This finding is in agreement with previous studies (Huang et al., 2010; Mackenzie et al., 2010, 2011), which showed that ROS induction is a pivotal event in the anticancer effect of phospho-NSAIDs. Cancer cells are often in a heightened state of oxidative stress (Diehn et al., 2009).
Phospho-non-steroidal anti-inflammatory drugs (phospho-NSAIDs) are a novel class of NSAID derivatives with potent antitumor activity. However, phospho-NSAIDs have limited stability in vivo due to their rapid hydrolysis by carboxylesterases at their carboxylic ester link. Here, we synthesized phospho-ibuprofen amide (PIA), a metabolically stable analog of phospho-ibuprofen, formulated it in nanocarriers, and evaluated its pharmacokinetics and anticancer efficacy in pre-clinical models of human lung cancer. PIA was 10-fold more potent than ibuprofen in suppressing the growth of human non-small-cell lung cancer (NSCLC) cell lines, an effect mediated by favorably altering cytokinetics and inducing oxidative stress. Pharmacokinetic studies in rats revealed that liposome-encapsulated PIA exhibited remarkable resistance to hydrolysis by carboxylesterases, remaining largely intact in the systemic circulation, and demonstrated selective distribution to the lungs. The antitumor activity of liposomal PIA was evaluated in a metastatic model of human NSCLC in mice. Liposomal PIA strongly inhibited lung tumorigenesis (>95%) and was significantly (p < 0.05) more efficacious than ibuprofen. We observed a significant induction of urinary 8-iso-prostaglandin F_2α in vivo, which indicates that ROS stress probably plays an important role in mediating the antitumor efficacy of PIA. Our findings suggest that liposomal PIA is a potent agent in the treatment of lung cancer and merits further evaluation.
The in vitro metabolism of phospho-sulindac amide, a novel potential anticancer agent
2014, Biochemical Pharmacology
Phospho-sulindac amide (PSA) is a novel potential anti-cancer and anti-inflammatory agent. Here we report the metabolism of PSA in vitro. PSA was rapidly hydroxylated at its butane-phosphate moiety to form two di-hydroxyl-PSA and four mono-hydroxyl-PSA metabolites in mouse and human liver microsomes. PSA also can be oxidized or reduced at its sulindac moiety to form PSA sulfone and PSA sulfide, respectively. PSA was mono-hydroxylated and cleared more rapidly in mouse liver microsomes than in human liver microsomes. Of eight major human cytochrome P450s (CYPs), CYP3A4 and CYP2D6 exclusively catalyzed the hydroxylation and sulfoxidation reactions of PSA, respectively. We also examined the metabolism of PSA by three major human flavin monooxygenases (FMOs). FMO1, FMO3 and FMO5 were all capable of catalyzing the sulfoxidation (but not hydroxylation) of PSA, with FMO1 being by far the most active isoform. PSA was predominantly sulfoxidized in human kidney microsomes because FMO1 is the dominant isoform in human kidney. PSA (versus sulindac) is a preferred substrate of both CYPs and FMOs, likely because of its greater lipophilicity and masked–COOH group. Ketoconazole (a CYP3A4 inhibitor) and alkaline pH strongly inhibited the hydroxylation of PSA, but moderately suppressed its sulfoxidation in liver microsomes. Together, our results establish the metabolic pathways of PSA, identify the major enzymes mediating its biotransformations and reveal significant inter-species and inter-tissue differences in its metabolism.
NSAID-induced corneal melt: Clinical importance, pathogenesis, and risk mitigation
2020, Survey of Ophthalmology
Citation Excerpt :
Cell death seems to be a primary event, and it is likely that “compromised” corneal epithelial cells respond differently to NSAIDs than healthy ones. Indeed, differential response to NSAIDs between normal and abnormal cells in terms of cell death is known.55 The persistence of the damage to the corneal surface (diminished tissue repair) appears to be a fateful development that, with the help of the right MMPs breaking down collagen, can culminate in the catastrophic perforation of the globe.
Corneal melt, an ophthalmological condition in which corneal epithelium is lost accompanied by thinning of the corneal stroma, can lead to corneal perforation and cause loss of vision. Corneal melt is the most serious side effect of topical nonsteroidal anti-inflammatory drugs (NSAIDs), one of the topical treatments of ocular inflammation. NSAID-induced corneal melt (NICM), initially doubted, is real, having been reported by multiple groups. NICM is induced by all but one of the approved ocular NSAIDs and occurs usually in patients whose cornea is compromised by ocular surgery, diabetes, or autoimmune diseases. Its true incidence, most likely low, remains unknown. NSAID dose and duration of treatment may be important for NICM. NICM appears to evolve in two stages: the epithelial stage—marked by a corneal epithelial defect, reduced eicosanoid levels, leukocyte infiltration, and matrix metalloproteinase–facilitated desquamation—and the stromal stage, characterized by degradation of stromal collagen by activated matrix metalloproteinases. Awareness of this ominous side effect, its risk factors, and the need for prompt action once diagnosed, including NSAID discontinuation, will help mitigate the risk of NICM. Further understanding of NICM and development of efficacious treatments or safer alternatives should help eliminate this rare, but severe, side effect of ocular NSAIDs.

View all citing articles on Scopus

: Conflicts of interest The authors disclose no conflicts, except for B.R., who has an equity position in Medicon, Inc.

: Funding This study was supported by grant R01-CA139453; N01-CN-43302 WA#7.

View full text

Basic—Alimentary TractPhospho-Sulindac (OXT-328), a Novel Sulindac Derivative, Is Safe and Effective in Colon Cancer Prevention in Mice

Background & Aims

Methods

Results

Conclusions

Section snippets

Reagents and Cell Culture

P-S Inhibits the Growth of Cultured Colon Cancer Cells Through a Strong Cytokinetic Effect

Discussion

J Chromatogr

Biochem Pharmacol

J Biol Chem

Sulindac suppresses tumorigenesis in the Min mouse

Carcinogenesis

Polyamines and cancer: old molecules, new understanding

Nat Rev Cancer

Difluoromethylornithine plus sulindac for the prevention of sporadic colorectal adenomas: a randomized placebo-controlled, double-blind trial

Cancer Prev Res (Phila Pa)

Analgesic-antipyretic and antiinflammatory agents and drugs employed in the treatment gout

A novel sulindac derivative that does not inhibit cyclooxygenases but potently inhibits colon tumor cell growth and induces apoptosis with antitumor activity

Cancer Prev Res (Phila Pa)

Basic—Alimentary Tract
Phospho-Sulindac (OXT-328), a Novel Sulindac Derivative, Is Safe and Effective in Colon Cancer Prevention in Mice