Apoptosis induced by sulindac sulfide in epithelial and mesenchymal cells from human abdominal neoplasms

Desmoid Tumors Characteristics, Clinical Management, Active Surveillance, and Description of Our FAP Case Series

(1) Background: desmoid tumors (DTs) are common in patients with familial adenomatous polyposis (FAP). An active surveillance approach has been recently proposed as a valuable alternative to immediate treatment in some patients. However, no clear indication exists on which patients are suitable for active surveillance, how to establish the cut-off for an active treatment, and which imaging technique or predictive factors should be used during the surveillance period. (2) Results: we retrospectively analyzed 13 FAP patients with DTs. A surveillance protocol consisting of scheduled follow-up evaluations depending on tumor location and tissue thickening, abdominal computed tomography (CT) scan/Magnetic resonance imaging (MRI) allowed prompt intervention in 3/11 aggressive intra-abdominal DTs, while sparing further interventions in the remaining cases, despite worrisome features detected in three patients. Moreover, we identified a possible predictive marker of tumor aggressiveness, i.e., the "average monthly growth rate" (AMGR), which could distinguish patients with very aggressive/life-threatening tumor behavior (AMGR > 0.5) who need immediate active treatment, from those with stable DTs (AMGR < 0.1) in whom follow-up assessments could be delayed. (3) Conclusion: surveillance protocols may be a useful approach for DTs. Further studies on larger series are needed to confirm the usefulness of periodic CT scan/MRI and the value of AMGR as a prognostic tool to guide treatment strategies.

Activated Signaling Pathways and Targeted Therapies in Desmoid-Type Fibromatosis: A Literature Review

Desmoid-type fibromatosis (DTF) is a rare, soft tissue tumor of mesenchymal origin which is characterized by local infiltrative growth behavior. Besides “wait and see,” surgery and radiotherapy, several systemic treatments are available for symptomatic patients. Recently, targeted therapies are being explored in DTF. Unfortunately, effective treatment is still hampered by the limited knowledge of the molecular mechanisms that prompt DTF tumorigenesis. Many studies focus on Wnt/β-catenin signaling, since the vast majority of DTF tumors harbor a mutation in the CTNNB1 gene or the APC gene. The established role of the Wnt/β-catenin pathway in DTF forms an attractive therapeutic target, however, drugs targeting this pathway are still in an experimental stage and not yet available in the clinic. Only few studies address other signaling pathways which can drive uncontrolled growth in DTF such as: JAK/STAT, Notch, PI3 kinase/AKT, mTOR, Hedgehog, and the estrogen growth regulatory pathways. Evidence for involvement of these pathways in DTF tumorigenesis is limited and predominantly based on the expression levels of key pathway genes, or on observed clinical responses after targeted treatment. No clear driver role for these pathways in DTF has been identified, and a rationale for clinical studies is often lacking. In this review, we highlight common signaling pathways active in DTF and provide an up-to-date overview of their therapeutic potential.

Treatment of Desmoids and Mesenteric Fibromatosis in Familial Adenomatous Polyposis with Raloxifene

Background

Among the great variety of extracolonic manifestations of familial adenomatous polyposis, the most serious are desmoids and fibromatosis of the abdominal cavity. These may be a danger to the patient and a concern to the clinician. Pharmacological management of this relentless problem is favored by surgical intervention. At present, however, beneficial actions of medical therapy are not separable from undesirable side effects.

Methods

We studied the effects of 120 mg daily of raloxifene, a non-steroidal benzothiophene, on progressive desmoid tumors and mesenteric fibromatosis by evaluation of lesion size and symptoms in 13 patients with familial adenomatous polyposis, selected on the basis of intra-abdominal localization of the lesion, on refractoriness to other medical treatments, and on estrogen receptor-α expression.

Results

The patients had a significant response to raloxifene therapy, with complete remission in 8 cases and partial response in 5 cases, evaluated by regression of symptoms and tumor size. Serum biochemical parameters did not show any significant changes. Side effects were never observed.

Conclusions

Although the number of patients included in the study is limited and in spite of some limitations, the available results support that, in the evaluation of response, daily therapy with raloxifene decreases desmoid tumor and mesenteric fibromatosis size and symptoms and does not cause side effects. These findings offer a novel option in the pharmacological treatment of desmoids, leading to medical therapy of these neoplastic lesions in familial adenomatous polyposis patients.

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS ARREST CELL CYCLE IN G0/G1PHASE AND INDUCE CELL DEATH IN OSTEOBLAST-ENRICHED CULTURES

Nonsteroidal anti-inflammatory drugs have been widely prescribed for orthopaedic patients to relieve pain and chronic inflammation. However, it has been demonstrated that NSAIDs suppress bone repair and remodeling in vivo. We have reported that ketorolac inhibits bone repair in vivo and its critical effective timing is at the early stage of endochondral ossification. Our previous results showed that ketorolac and indomethacin inhibit osteoblast proliferation in vitro, suggesting that this effect may be one of the mechanisms contributing to the suppressive effect of NSAIDs on bone remodeling. Cell proliferation and death of osteoblasts should be well regulated through some relative apoptotic and mitotic factors during normal bone remodeling process. Accordingly, we proposed that the induction of osteoblastic cell death of NSAIDs might be one of the mechanisms involving their suppressive effect on bone remodeling in vivo. In this study, we investigated whether NSAIDs arrest osteoblastic cell cycle and/or induce cell death. Whether the mechanism was mediated through prostaglandin (PG) pathway. We tested the effects of ketorolac, indomethacin, diclofenac, piroxicam on cell cycle kinetics, cytotoxicity, and cell death pattern in osteoblast-enriched cultures derived from fetal rat calvaria. Our results showed that ketorolac and indomethacin arrested cell cycle at G0/G1phase. All the 4 NSAIDs had cytotoxic effects and these effects were concentration dependent. The sequence of the cytotoxic effects of these four NSAIDs at 10-4M were indomethacin > diclofenac > ketorolac > piroxicam. Both PGE1and PGE2(10-10-10-8M) also significantly elevated the LDH leakage of osteoblasts, while PGF2αhad no significant effect. These results revealed that the cytotoxic effects of NSAIDs on osteoblasts might not be through inhibiting prostaglandin synthesis. They may be through PG-independent pathways. The results from flow cytometry followed by AnnexinV-FITC and propidium iodide double staining showed that 24 hours treatment of all the 4 NSAIDs (10-6and 10-4M) significantly induced both apoptosis (p<0.01) and necrosis (p<0.01, or p<0.05) in osteoblast cultures. These effects of NSAIDs on cell cycle arrest and cell death induction in osteoblasts may be one of the important mechanisms contributing to their suppressive effect on bone repair and bone remodeling in vivo.

A comparison of methods for the analysis of low abundance proteins in desmoid tumor cells

The desmoids are a group of rare clinically diverse, deep-seated fibrous neoplasms. The exact etiology is unknown, but several factors are considered to be positively correlated with their development and growth, i.e., genetic and hormonal factors and trauma. These tumors may be sporadic or associated with a genetic disease such as familial adenomatous polyposis (FAP). Devoid of metastatic potential, they tend to form large, infiltrative masses which, if not completely excised, recur repeatedly. Although surgery is widely accepted as the first-line treatment for extra-abdominal and abdominal wall desmoids, a proportion of cases are successfully palliated with either estrogen antagonists (tamoxifen, toremifene, and raloxifene) or nonsteroidal anti-inflammatory drugs. We describe and compare four methods for evaluating the expression of estrogen receptors alpha/beta and COX-1 and COX-2 in desmoid tumor-derived cells and tissues: immunocytochemistry, immunohistochemistry, RT-PCR, and two-color Western blot detection with the Odyssey infrared imaging system. Through this comparative analysis, Western blot with Odyssey was recognized as the best method to analyze the expression particularly of low expressed proteins in desmoid-derived cells. The use of a specific and reliable assessment method becomes fundamental in the evaluation of the presence and modulation of proteins which are important but weakly expressed in these rare tumors.

Selective oestrogen receptor modulators in desmoid tumours

Selective oestrogen receptor modulators (SERMs) are compounds with a mixed agonist/antagonist activity on oestrogen receptors. An ideal SERM is a compound with an oestrogen antagonist effect on the breast and uterus but oestrogen agonist effect on bone. Beside tamoxifen, a group of well-investigated SERMs is represented by raloxifene, LY-353381 (SERM3), EM-800 and CP-336156. On an empirical basis, tamoxifen has been used to pharmacologically treat desmoid tumours. Recently, raloxifene, a second-generation SERM, has been used in the treatment of familial adenomatous polyposis patients affected by desmoid tumour. The mechanisms through which these molecules affect desmoid tumour growth appear to be due, in part, to the fact that SERMs may act independently of oestrogen receptors. The knowledge of the molecular basis of SERM action will make the development of novel synthetic compounds with engineered tissue selectivity possible.

Nonsteroidal anti-inflammatory drug effects on osteoblastic cell cycle, cytotoxicity, and cell death

Previous studies indicated that nonsteroidal anti-inflammatory drugs (NSAIDs) suppress bone repair, growth, and remodeling in vivo. Our previous in vitro study demonstrated that indomethacin and ketorolac inhibited osteoblast proliferation. In this study, we further investigated the influences of 4 NSAIDs on cell cycle kinetics, cytotoxicity, and cell death pattern in osteoblast cultures from rat fetal calvaria. Our results showed that NSAIDs significantly arrested cell cycle at the G(0)/G(1) phase and induced cytotoxicity and cell death of osteoblasts. Apoptosis was more pronounced than necrosis caused by NSAIDs. Among these NSAIDs, piroxicam showed the least effect to produce osteoblastic dysfunction. Moreover, we found that the cytotoxic and apoptotic effects of NSAIDs on osteoblasts might not be prostaglandin related. These results suggest that the NSAID effects on cell cycle arrest and cell death induction in osteoblasts may be one of the important mechanisms contributing to their suppressive effect on bone formation.

Methionine sulfoxide reductases: history and cellular role in protecting against oxidative damage

An enzyme that can reduce methionine sulfoxide in proteins was first discovered in Escherichia coli about 25 years ago. It is now apparent that there is a family of enzymes, referred to as methionine sulfoxide reductases (Msr), and in recent years there has been considerable interest in one of the members of the Msr family, MsrA. This enzyme has been shown to protect cells against oxidative damage, which suggests a possible role in a large number of age-related diseases. This review summarizes the history of the discovery of MsrA, properties of the enzyme and its role in protecting cells against oxidative damage. Other members of the Msr family that differ in substrate specificity and localization are described as well as a possible role for the Msr system in drug metabolism. The concept that the Msr system can be used to develop novel drugs that could be catalytic anti-oxidants is discussed.

Reduction of Sulindac to its active metabolite, sulindac sulfide: assay and role of the methionine sulfoxide reductase system

Sulindac is a known anti-inflammatory drug that functions by inhibition of cyclooxygenases 1 and 2 (COX). There has been recent interest in Sulindac and other non-steroidal anti-inflammatory drugs (NSAID) because of their anti-tumor activity against colorectal cancer. Studies with sulindac have indicated that it may also function as an anti-tumor agent by stimulating apoptosis. Sulindac is a pro-drug, containing a methyl sulfoxide group, that must be reduced to sulindac sulfide to be active as a COX inhibitor. In the present studies we have developed a simple assay to measure sulindac reduction and tested sulindac as a substrate for 6 known members of the methionine sulfoxide reductase (Msr) family that have been identified in Escherichia coli. Only MsrA and a membrane associated Msr can reduce sulindac to the active sulfide. The reduction of sulindac also has been demonstrated in extracts of calf liver, kidney, and brain. Sulindac reductase activity is also present in mitochondria and microsomes.

Sulindac targets nuclear beta-catenin accumulation and Wnt signalling in adenomas of patients with familial adenomatous polyposis and in human colorectal cancer cell lines

Nonsteroidal anti-inflammatory drugs (NSAIDs) have chemopreventive potential against colorectal carcinomas (CRCs). Inhibition of cyclooxygenase (COX)-2 underlies part of this effect, although COX-2-independent mechanisms may also exist. Nonsteroidal anti-inflammatory drugs appear to inhibit the initial stages of the adenoma-carcinoma sequence, suggesting a link to the APC/beta-catenin/TCF pathway (Wnt-signalling pathway). Therefore, the effect of the NSAID sulindac on nuclear (nonphosphorylated) beta-catenin and beta-catenin/TCF-mediated transcription was investigated. Nuclear beta-catenin expression was assessed in pretreatment colorectal adenomas and in adenomas after treatment with sulindac from five patients with familial adenomatous polyposis (FAP). Also, the effect of sulindac sulphide on beta-catenin/TCF-mediated transcription was studied. Adenomas of FAP patients collected after treatment with sulindac for up to 6 months showed less nuclear beta-catenin expression compared to pretreatment adenomas of the same patients. Sulindac sulphide abrogated beta-catenin/TCF-mediated transcription in the CRC cell lines DLD1 and SW480, and decreased the levels of nonphosphorylated beta-catenin. As a result, the protein levels of the positively regulated TCF targets Met and cyclin D1 were downregulated after sulindac treatment. This study provides in vivo and in vitro evidence that nuclear beta-catenin localisation and beta-catenin/TCF-regulated transcription of target genes can be inhibited by sulindac. The inhibition of Wnt-signalling provides an explanation for the COX-2-independent mechanism of chemoprevention by NSAIDs.

Desmoid tumour in familial adenomatous polyposis. A review of literature

Desmoid tumours (DT) are rare benign tumours that do not metastasise, but tend to invade locally. DT are frequently seen in patients with familial adenomatous polyposis (FAP), and diagnosis and treatment are often difficult. Surgical trauma, genetic predisposition and hormonal factors are considered to be correlated with the development and growth of DT. In patients with FAP, 50% of the tumours are localised intra-abdominally, and 85-100% of these are mesenteric. DT frequently present as non- tender, slowly growing masses. The symptoms are abdominal pain, vomiting, diarrhoea or haematochezia. Mesenteric DT can cause small bowel obstruction or ischaemia, hydronephrosis or form fistulas. Diagnosis is obtained through biopsy and the extension is determined by a CT-scan. Surgical excision is recommended in patients with DT in the abdominal wall. First line treatment of mesenteric DT is a NSAID in combination with tamoxifen. Surgery may be considered in case of a small and well-defined DT with no signs of invasion of vital structures, and in cases of imminent bowel ischaemia or obstruction. The prognosis in mesenteric DT is serious, and improvement of the therapeutic strategy awaits current international studies.

Gene modulation by the cyclooxygenase inhibitor, sulindac sulfide, in human colorectal carcinoma cells: possible link to apoptosis

The mechanisms underlying the anti-tumorigenic properties of cyclooxygenase inhibitors are not well understood. One novel hypothesis is alterations in gene expression. To test this hypothesis sulindac sulfide, which is used to treat familial adenomatous polyposis, was selected to detect gene modulation in human colorectal cells at physiological concentrations with microarray analysis. At micromolar concentrations, sulindac sulfide stimulated apoptosis and inhibited the growth of colorectal cancer cells on soft agar. Sulindac sulfide (10 microm) altered the expression of 65 genes in SW-480 colorectal cancer cells, which express cyclooxygenase-1 but little cyclooxygenase-2. A more detailed study of 11 genes revealed that their expression was altered in a time- and dose-dependent manner as measured by real-time RT-PCR. Northern analysis confirmed the expression of 9 of these genes, and Western analysis supported the conclusion that sulindac sulfide altered the expression of these proteins. Cyclooxygenase-deficient HCT-116 cells were more responsive to sulindac sulfide-induced gene expression than SW-480 cells. However, this response was diminished in HCT-116 cells overexpressing cyclooxygenase-1 compared with normal HCT-116 cells suggesting the presence of cyclooxygenase attenuates this response. However, prostaglandin E2, the main product of cyclooxygenase, only suppressed the sulindac sulfide-induced expression of two genes, with little known biological function while it modulated the expression of two more. The most likely explanation for this finding is the metabolism of sulindac sulfide to inactive metabolites by the peroxidase activity of cyclooxygenase. In conclusion, this is the first report showing sulindac sulfide, independent of cyclooxygenase, altered the expression of several genes possibly linked to its anti-tumorigenic and pro-apoptotic activity.

Effects of nonsteroidal anti-inflammatory drugs on transforming growth factor-beta expression and bioactivity in rat osteoblast-enriched culture

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to suppress bone remodeling in normal and repaired bones. Our previous results indicated that ketorolac and indomethacin suppressed proliferation, stimulated early differentiation, and induced apoptosis in cultured osteoblasts. Transforming growth factor-beta (TGF-beta) has been reported to enhance proliferation, suppress differentiation, and prevent apoptosis in osteoblasts. We proposed that one pathway of NSAID effects on osteoblast function might be through inhibition of the expression and/or bioactivity of TGF-beta in osteoblasts. We tested the effects of ketorolac and indomethacin on the expression of TGF-beta1 mRNA and protein and the bioactivity of TGF-beta in osteoblast-enriched cultures derived from fetal calvaria. The effects of prostaglandin E1 (PGE1) and PGE2 on TGF-beta expression and bioactivity were also examined in order to understand more about the role of prostaglandins in osteoblast function. Simultaneously, we estimated whether these NSAID effects on osteoblasts were prostaglandin-related. The results showed that 24-hour treatments with both PGEs and theoretic therapeutic concentrations of ketorolac and indomethacin had no significant effects on the levels of either transcription or translation of TGF-beta or the post-translational function of TGF-beta in osteoblasts. These results suggest that NSAIDs do not affect osteoblast function through changes in TGF-beta action in osteoblasts.

Aspirin and NS-398 inhibit hepatocyte growth factor-induced invasiveness of human hepatoma cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) activity and are considered to exert antitumor actions in a variety of cancer cells, although the effects are unlikely entirely due to COX inhibition. Because clinical observations suggest that hepatocyte growth factor (HGF) can promote metastasis of hepatoma cells while stimulating tumor invasiveness, we investigated the effect of aspirin and NS-398, a selective COX-2 inhibitor, on HGF-mediated invasiveness of HepG2 human hepatoma cells. HGF stimulated the invasiveness of HepG2 cells in Matrigel cell invasion assay, together with increased expression of matrix metalloproteinase (MMP) 9. Addition of aspirin or NS-398, similar to PD98059, which acts as a specific inhibitor of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK), an upstream kinase regulating extracellular signal-regulated kinase (ERK)1/2, abrogated such actions of HGF without affecting cell viability. Aspirin and NS-398, in contrast to PD98059, did not suppress ERK1/2 phosphorylation induced by HGF. However, both agents inhibited the kinase activity of ERK1/2 induced by HGF and repressed HGF-induced phosphorylation of 90-kd ribosomal S6 kinase (RSK) and Elk-1, key downstream substrates of ERK1/2, resulting in the suppression of transcriptional activity of Elk-1 as well as nuclear factor kappaB (NF-kappaB) and AP-1, which are involved in MMP-9 gene regulation. In conclusion, our results suggest that aspirin and NS-398 inhibit HGF-induced invasiveness of HepG2 human hepatoma cells through ERK1/2.

Germline alterations in the cyclooxygenase-2 gene are not associated with the development of extracolonic manifestations in a large swiss familial adenomatous polyposis kindred

Familial adenomatous polyposis (FAP) is an autosomal dominant condition leading to the development of multiple colorectal polyps and other features. Intrafamilial variation in phenotype is known to occur in FAP; despite carrying the same causing mutation in the APC gene, disease expression may considerably differ in affected individuals, likely due to the existence of modifier genes. Several lines of evidence suggest the cyclooxygenase-2 (COX-2) gene to be a candidate modifier in FAP. Since COX-2 appears to be expressed in tissues prone to be affected in FAP, it might influence the occurrence of extracolonic manifestations in this disorder. Herein, we investigated whether alterations in the COX-2 gene are involved in the development of extracolonic polyps and extragastrointestinal features. Mutational analysis using single-strand conformation polymorphism (SSCP) in 130 members of a FAP family displaying strong phenotype variation revealed 3 polymorphic sites within the coding region of the COX-2 gene. None of these allelic variants, however, segregated with a particular disease phenotype. In addition, expression analysis was performed in 31 family members with representative phenotypes. Neither of the two polymorphisms detected within the COX-2 promoter was associated with a given phenotype nor was there a significant difference in quality or quantity of COX-2 mRNA in lymphocytes as measured by reverse transcription- and real time quantitative reverse transcription PCR (RT-PCR and TaqMan). In conclusion, germline alterations in the COX-2 gene are unlikely to account for the development of extracolonic disease in FAP patients.

Long-term treatment with sulindac in familial adenomatous polyposis: is there an actual efficacy in prevention of rectal cancer?

BACKGROUND AND OBJECTIVES

Ileorectal anastomosis (IRA) is still used in the treatment of familial adenomatous polyposis (FAP). Sulindac appears to induce regression of colorectal adenomas; however, its effects in long-term therapy and in preventing carcinoma remain unclear.

METHODS

Fifteen FAP patients treated by IRA received sulindac (200 mg/day) for a mean period of 48.6 +/- 28.7 (range 12-124) months. Number, size, and type of rectal polyps were assessed by endoscopic and histological evaluation every 6 months.

RESULTS

Significant regression of polyps was observed in all patients after 6 months (P < 0.02). However, after a mean of 48.6 +/- 28.7 months, both number and size of polyps increased again, showing no statistical difference with baseline values. Minute polyps appeared reddish, while the largest lesions were flat or slightly elevated. Endoscopic polypectomy was necessary in 9 patients and transanal surgical excision in 3. Two patients were submitted to restorative proctectomy because of a large polyp with severe dysplasia and a rectal cancer, respectively.

CONCLUSIONS

Sulindac appears to influence the morphological appearance of polyps in FAP patients, inducing apparent regression. However, at a dose of 200 mg, it does not influence the progression of polyps toward a malignant pattern.