Novel sensitizing agents: Potential Contribution of COX-2 inhibitor for endocrine therapy of breast cancer

Lobe-specific responses of TRAMP mice dorsolateral prostate following celecoxib and nintedanib therapy

Delayed cancer progression in the ventral prostate of the Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model has been previously reported upon celecoxib and nintedanib co-administration. Herein, we sought to further investigate the effects of these drugs association in some of their direct molecular targets (COX-2, VEGF and VEGFR-2) and in reactive stroma markers (TGF-β, αSMA, vimentin and pro-collagen 1) in the dorsolateral prostate, looking for lobe-specific responses. Male TRAMP mice were treated with celecoxib (10 mg/Kg, i.o.) and/or nintedanib (15 mg/Kg, i.o.) for 6 weeks and prostate was harvested for morphological and protein expression analyses. Results showed that combined therapy resulted in unique antitumor effects in dorsolateral prostate, especially due to the respective stromal or epithelial antiproliferative actions of these drugs, which altogether led to a complete inversion in high-grade (HGPIN) versus low-grade (LGPIN) premalignant lesion incidences in relation to controls. At the molecular level, this duality in drug action was paralleled by the differential down/upregulation of TGF-β signaling by celecoxib/nintedanib, thus leading to associated changes in stroma composition towards regression or quiescence, respectively. Additionally, combined therapy was able to promote decreased expression of inflammatory (COX-2) and angiogenesis (VEGF/VEGFR-2) mediators. Overall, celecoxib and nintedanib association provided enhanced antitumor effects in TRAMP dorsolateral as compared to former registers in ventral prostate, thus demonstrating lobe-specific responses of this combined chemoprevention approach. Among these responses, we highlight the ability in promoting TGF-β signaling and its associated stromal maturation/stabilization, thus yielding a more quiescent stromal milieu and resulting in greater epithelial proliferation impairment.

Celecoxib as a Valuable Adjuvant in Cutaneous Melanoma Treated with Trametinib

BACKGROUND

Melanoma patients stop responding to targeted therapies mainly due to mitogen activated protein kinase (MAPK) pathway re-activation, phosphoinositide 3 kinase/the mechanistic target of rapamycin (PI3K/mTOR) pathway activation or stromal cell influence. The future of melanoma treatment lies in combinational approaches. To address this, our in vitro study evaluated if lower concentrations of Celecoxib (IC50 in nM range) could still preserve the chemopreventive effect on melanoma cells treated with trametinib.

MATERIALS AND METHODS

All experiments were conducted on SK-MEL-28 human melanoma cells and BJ human fibroblasts, used as co-culture. Co-culture cells were subjected to a celecoxib and trametinib drug combination for 72 h. We focused on the evaluation of cell death mechanisms, melanogenesis, angiogenesis, inflammation and resistance pathways.

RESULTS

Low-dose celecoxib significantly enhanced the melanoma response to trametinib. The therapeutic combination reduced nuclear transcription factor (NF)-kB (p < 0.0001) and caspase-8/caspase-3 activation (p < 0.0001), inhibited microphthalmia transcription factor (MITF) and tyrosinase (p < 0.05) expression and strongly down-regulated the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway more significantly than the control or trametinib group (p < 0.0001).

CONCLUSION

Low concentrations of celecoxib (IC50 in nM range) sufficed to exert antineoplastic capabilities and enhanced the therapeutic response of metastatic melanoma treated with trametinib.

The role of prostaglandin E2 in renal cell cancer development: future implications for prognosis and therapy

COX-2 plays a crucial pathophysiological role in the development of renal cell cancer (RCC). Recently, it has been shown that COX-2 inhibition enhances the efficacy of immunotherapy and tyrosine kinase inhibitor-based treatment. At the same time, molecular analyses revealed particular contribution of a COX-2 product - prostaglandin E2 (PGE2) - in RCC development. PGE2 was shown to activate Akt/RGC2/RalA signaling cascade in RCC cells. It also demonstrated upregulation of the expression of HIF-1α and PI3K/Akt/mTOR signaling pathway. All together, these data suggest that targeted anti-PGE2 therapies may offer an interesting therapeutic option for RCC patients in the future.

High-intensity focused ultrasound provides palliation for liver metastasis causing gastric outlet obstruction: case report

Background

Surgery is the standard of care in several oncologic diseases. However, when non-surgical candidates are not suitable for radical treatment, palliation must be achieved at least. High-intensity focused ultrasound uses ultrasound power that can be sharply focused for highly localised application, as it is a completely non-invasive procedure. Its non-invasiveness appears to be of paramount importance in critically ill patients.

Case description

We describe the use of ultrasound-guided high-intensity focused ultrasound for a large liver metastasis from breast cancer causing gastric outlet obstruction in a metastatic disease. The left liver deposit did not allow the stomach to empty due to its large volume, and the patient was unable to eat properly. The tumour was metastatic, resistant to chemotherapy and had a size that contraindicated an ablation percutaneous technique. To improve the patient's quality of life, ultrasound-guided high-intensity focused ultrasound ablation seemed the only and most suitable option. Therefore, a high-intensity focused ultrasound treatment was performed, no complications occurred and the patient's general condition has improved since the early post-procedural period. Three months after treatment, two body mass index points were gained, and the lesion decreased by 72% in volume as detected through multi-detector computed tomography follow-up.

Discussion and conclusion

Quality of life is an unquestionable goal to achieve, and palliation must be achieved while causing as little harm as possible. In this view, debulking surgery and percutaneous ablation technique seemed not appropriate for our patient. Instead, high-intensity focused ultrasound combined several advantages, no lesion size limit and a totally non-invasive treatment. Thus, this technique proved to be a clinically successful procedure, offering better disease control and quality of life. In circumstances where other alternatives clearly seem to fail or are contraindicated, high-intensity focused ultrasound can be used and can provide benefits. We recommend its use and development in several oncologic diseases, not only for therapeutic purposes but also for the improvement of patient's quality of life.

Tumor stroma as targets for cancer therapy

Cancer is not only composed malignant epithelial component but also stromal components such as fibroblasts, endothelial cells, and inflammatory cells, by which an appropriate tumor microenvironment (TME) is formed to promote tumorigenesis, progression, and metastasis. As the most abundant component in the TME, cancer-associated fibroblasts (CAFs) are involved in multifaceted mechanistic details including remodeling the extracellular matrix, suppressing immune responses, and secreting growth factors and cytokines that mediate signaling pathways to extensively affect tumor cell growth and invasiveness, differentiation, angiogenesis, and chronic inflammatory milieu. Today, more and more therapeutic strategies are purposefully designed to target the TME as well as tumor cells. This review will focus on the role of CAFs in tumor development and the novel strategies to target this component to inhibit the tumor growth.

Cyclooxygenase-2 expression in non-Hodgkin's lymphomas

Cyclooxygenase 2 (Cox-2) is a key enzyme in prostaglandin synthesis and it has an important role in the pathogenesis of various malignancies. Cox-2 has been studied in solid tumors; however, studies about the role of Cox-2 in non-Hodgkin's lymphomas (NHL) are limited. The aim of this study is to determine the importance of Cox-2 expression in lymphomas. To this end, Cox-2 expression was determined in 177 cases with NHL. In histological terms, 60 cases (33%) had low grade and 117 (67%) had aggressive lymphoma. Ninety-nine cases were found to be positive for Cox-2 (56%); Cox-2 score was between 50 and 100, 101 and 200 and over 200 in 38, 46 and 15 cases, respectively. There was an important association between aggressive histology and Cox-2 expression: Cox-2 was negative in about half of the cases with indolent morphology, while two thirds of the Cox-2 positive cases had aggressive histology (p = 0.036). There was no significant association between Cox-2 expression and clinical-laboratory parameters. Although the overall survival times were longer in cases with lower or no Cox-2 expression as compared with higher Cox-2 expression, the difference was not significant. In conclusion Cox-2 expression is seen about 60% of the cases with NHL and is associated with aggressive morphology.

Chemopreventive agents induce oxidative stress in cancer cells leading to COX-2 overexpression and COX-2-independent cell death

Chemopreventive agents generate oxidative stress, which culminates in cell death and may be part of a general mechanism of chemoprevention. The redox-responsive cyclooxygenase (COX)-2, overexpressed during carcinogenesis, has been a target for cancer prevention. To assess the potential link between chemopreventive agents, oxidative stress and COX-2, we studied the chemopreventive sulindac and nitric oxide-donating aspirin (NO-ASA). Both generated oxidative stress and induced COX-2 in various cell lines, more prominently in dying cells. Two antioxidants and an inhibitor of NADPH oxidase abrogated the induction of COX-2 and cell death. Exogenous xanthine/xanthine oxidase, which produce O(2)(-)., had the same effect. Inhibition of caspases and cox-2 knockdown showed that COX-2 did not participate in reactive oxygen species (ROS) generation or cell death induction in response to NO-ASA. Our results support three potentially useful ideas: (i) the concept that ROS are a critical component of the action of chemopreventive agents; (ii) the notion that COX-2 may not be an ideal target for chemoprevention and (iii) the possibility that COX-2 may be overexpressed in cancer cells due to their state of oxidative stress. It is conceivable that, if further substantiated, these findings may inform the rational design of chemotherapeutic strategies, in particular the choice of agents in combination approaches.

The effects of non-steroidal anti-inflammatory drug application on incisional wound healing in rats

OBJECTIVE

There is evidence that non-steroidal anti-inflammatory drugs (NSAIDs) delay both epithelialisation and angiogenesis in the early phases of wound healing because of an antiproliferative effect. We investigated the influence of diclofenac, a non-selective NSAID, on incisional wound healing.

METHOD

Ten male Wistar rats were given 5 mg diclofenac per kg bodyweight per day; 10 rats were given placebo pellets. After 10 days, unimpaired healing occurred independently of drug treatment both macroscopically and microscopically. Histomorphometry revealed a significant reduction (p = 0.006) in fibroblasts after diclofenac application (median 3 166 cells per mm2) compared with the placebo group (median 3940 cells per mm2). Epidermal thickness was not statistically different between the two groups.

RESULTS

Diclofenac diminished the amount of fibroblasts in connective tissue, reflecting the known antiproliferative effect of NSAIDs on fibroblasts. Clinical healing was not affected.

CONCLUSION

We recommend short-term diclofenac application for post-surgical and post-traumatic patients with wounds who would benefit from its antiphlogistic and analgesic effect. However, if wound healing is disturbed, the negative effect of diclofenac on fibroblasts should be considered. This is particularly relevant for patients with chronic wounds or conditions such as diabetes which can delay wound healing.

Celecoxib Prevents Neuroblastoma Tumor Development and Potentiates the Effect of Chemotherapeutic Drugs In vitro and In vivo

PURPOSE

Neuroblastoma is the most common and deadly solid tumor of childhood. Cyclooxygenase-2 is expressed in clinical neuroblastoma tumors and cell lines and inhibitors of this enzyme induce apoptosis in human neuroblastoma cells in vitro and in neuroblastoma xenografts in vivo. We hypothesized that the cyclooxygenase-2-specific inhibitor celecoxib could enhance the cytotoxic effect of chemotherapeutic drugs currently used in neuroblastoma treatment. Furthermore, we investigated if prophylactic treatment with celecoxib could prevent neuroblastoma tumor development in vivo.

EXPERIMENTAL DESIGN

Neuroblastoma cell cytotoxicity of chemotherapeutic drugs in combination with celecoxib was examined. In vivo, athymic rats carrying established SH-SY5Y xenografts were treated with celecoxib in combination with irinotecan, doxorubicin or etoposide, or with either drug alone. For prevention studies, rats received celecoxib in the diet, 250 to 2,500 ppm, from the time of tumor cell injection.

RESULTS

Celecoxib induced a synergistic or an additive cytotoxic effect in combination with doxorubicin, etoposide, irinotecan or vincristine in vitro. In vivo, treatment with celecoxib in combination with irinotecan or doxorubicin induced a significant growth inhibition of established neuroblastoma tumors. Rats receiving celecoxib in the diet showed a distinct dose-dependent delay in tumor development compared with untreated rats. Plasma levels of celecoxib were comparable with levels obtainable in humans.

CONCLUSIONS

Celecoxib potentiates the antitumor effect of chemotherapeutic drugs currently used in neuroblastoma treatment, which argues for clinical trials combining these drugs. Celecoxib could also be a potential drug for treatment of minimal residual disease.

Anti-inflammatory drugs in the 21st century

Historically, anti-inflammatory drugs had their origins in the serendipitous discovery of certain plants and their extracts being applied for the relief of pain, fever and inflammation. When salicylates were discovered in the mid-19th century to be the active components of Willow Spp., this enabled these compounds to be synthesized and from this, acetyl-salicylic acid or Aspirin was developed. Likewise, the chemical advances of the 19th-20th centuries lead to development of the non-steroidal anti-inflammatory drugs (NSAIDs), most of which were initially organic acids, but later non-acidic compounds were discovered. There were two periods of NSAID drug discovery post-World War 2, the period up to the 1970's which was the pre-prostaglandin period and thereafter up to the latter part of the last century in which their effects on prostaglandin production formed part of the screening in the drug-discovery process. Those drugs developed up to the 1980-late 90's were largely discovered empirically following screening for anti-inflammatory, analgesic and antipyretic activities in laboratory animal models. Some were successfully developed that showed low incidence of gastro-intestinal (GI) side effects (the principal adverse reaction seen with NSAIDs) than seen with their predecessors (e.g. aspirin, indomethacin, phenylbutazone); the GI reactions being detected and screened out in animal assays. In the 1990's an important discovery was made from elegant molecular and cellular biological studies that there are two cyclo-oxygenase (COX) enzyme systems controlling the production of prostanoids [prostaglandins (PGs) and thromboxane (TxA2)]; COX-1 that produces PGs and TxA2 that regulate gastrointestinal, renal, vascular and other physiological functions, and COX-2 that regulates production of PGs involved in inflammation, pain and fever. The stage was set in the 1990's for the discovery and development of drugs to selectively control COX-2 and spare the COX-1 that is central to physiological processes whose inhibition was considered a major factor in development of adverse reactions, including those in the GI tract. At the turn of this century, there was enormous commercial development following the introduction of two new highly selective COX-2 inhibitors, known as coxibs (celecoxib and rofecoxib) which were claimed to have low GI side effects. While found to have fulfilled these aims in part, an alarming turn of events took place in the late 2004 period when rofecoxib was withdrawn worldwide because of serious cardiovascular events and other coxibs were subsequently suspected to have this adverse reaction, although to a varying degree. Major efforts are currently underway to discover why cardiovascular reactions took place with coxibs, identify safer coxibs, as well as elucidate the roles of COX-2 and COX-1 in cardiovascular diseases and stroke in the hope that there may be some basis for developing newer agents (e.g. nitric oxide-donating NSAIDs) to control these conditions. The discovery of the COX isoforms led to establishing their importance in many non-arthritic or non-pain states where there is an inflammatory component to pathogenesis, including cancer, Alzheimer's and other neurodegenerative diseases. The applications of NSAIDs and the coxibs in the prevention and treatment of these conditions as well as aspirin and other analogues in the prevention of thrombo-embolic diseases now constitute one of the major therapeutic developments of the this century. Moreover, new anti-inflammatory drugs are being discovered and developed based on their effects on signal transduction and as anti-cytokine agents and these drugs are now being heralded as the new therapies to control those diseases where cytokines and other nonprostaglandin components of chronic inflammatory and neurodegenerative diseases are manifest. To a lesser extent safer application of corticosteroids and the applications of novel drug delivery systems for use with these drugs as well as with NSAIDs also represent newer technological developments of the 21st century. What started out as drugs to control inflammation, pain and fever in the last two centuries now has exploded to reveal an enormous range and type of anti-inflammatory agents and discovery of new therapeutic targets to treat a whole range of conditions that were never hitherto envisaged.

A novel pathway involving melanoma differentiation associated gene-7/interleukin-24 mediates nonsteroidal anti-inflammatory drug-induced apoptosis and growth arrest of cancer cells

Numerous studies show that nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in chemoprevention or treatment of cancer. Nevertheless, the mechanisms underlying these antineoplastic effects remain poorly understood. Here, we report that induction of the cancer-specific proapoptotic cytokine melanoma differentiation associated gene-7/interleukin-24 (MDA-7/IL-24) by several NSAIDs is an essential step for induction of apoptosis and G(2)-M growth arrest in cancer cells in vitro and inhibition of tumor growth in vivo. We also show that MDA-7/IL-24-dependent up-regulation of growth arrest and DNA damage inducible 45 alpha (GADD45alpha) and GADD45gamma gene expression is sufficient for cancer cell apoptosis via c-Jun NH(2)-terminal kinase (JNK) activation and growth arrest induction through inhibition of Cdc2-cyclin B checkpoint kinase. Knockdown of GADD45alpha and GADD45gamma transcription by small interfering RNA abrogates apoptosis and growth arrest induction by the NSAID treatment, blocks JNK activation, and restores Cdc2-cyclin B kinase activity. Our results establish MDA-7/IL-24 and GADD45alpha and GADD45gamma as critical mediators of apoptosis and growth arrest in response to NSAIDs in cancer cells.

Metastatic breast cancer: an updating

This article reports on recent advances on metastatic breast cancer. Detection, prognostic factors, predictors of response to therapy and therapy, with particular regard to targeted therapies, were examined.

DETECTION

Unlike current guidelines that yet do not routinely recommend intensive clinical-instrumental post-operative follow-up of breast cancer patients, relatively large data collected in the last decades have shown that an intensive post-operative follow-up with 'dynamic evaluation' of a suitable tumour marker panel precedes a few months as average the clinical and/or instrumental sign of a pending relapse in most relapsed patients and largely limits the use of the common instrumental examinations.

PROGNOSIS AND THERAPY PREDICTORS

Disease-free interval (DFI)<or=24 months, adjuvant chemotherapy, liver and distant soft tissue involvement or DFI>24 months and disease confined to bony skeleton are prognostic factors more often correlated with relatively poor or prolonged survival, respectively. Estrogen receptor (ER) expression in primary tumour and at the relapse correlates strongly with response to salvage hormone therapy and data from large trials showed that 38-59% of ER and/or PR+ post-menopausal patients had clinical benefit from first line tamoxifen or aromatase inhibitors. An inverse correlation of ER with epidermal growth factor receptor (EGFR) has been found. The co-expression of HER-2/neu and/or elevated serum HER-2/neu protein level were associated with a low rate and shorter duration of response of ER+ patients to first line hormone therapy. Accordingly, ER-EGFR- compared with ER-EGFR+ tumours are usually more responsive to endocrine therapy. High class III beta-tubulin expression or fall in insulin-like growth factor binding protein-3 (IGFBP-3) from baseline levels have been found to significantly predict resistance to chemotherapeutic agents.

THERAPY

Liposomes as carrier of doxorubicin (Caelix, Evacet, Myocet) is one approach to decrease the anthracycline-related cardiac toxicity. Weekly paclitaxel or docetaxel and oral formulation of vinorelbine and 5-fluorouracil (5-FU) (capecitabine) provide new effective and well tolerated options that reach greater dose intensity and cumulative dose than with the conventional schedules. As to the so called 'tailored' or targeted therapies, the more potent and highly selective third generation of aromatase inhibitors (letrozole, anastrozole, exemestane) targeting ER+ tumours by estrogen deprivation, challenge tamoxifen as current standard first line therapy in postmenopausals. One pilot study showed that stimulation of cellular immunity by the addition of beta-interferon-interleukin-2 sequence in patients on clinical benefit on first line tamoxifen significantly prolonged median overall survival (OS) and duration of response compared to that observed in similar patients only treated with tamoxifen. Trastuzumab, a humanised monoclonal antibody to extracellular domain of HER-2, plus conventional chemotherapy has become a standard of care for women with overexpressing HER-2 tumours. Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor (VEGF) that in refractory metastatic breast cancer doubled the response rate of capecitabine although it did not affect survival. Finally, the so called 'oligometastatic' and a few stage IV diseases are conditions amenable to be rendered with no evidence of disease (NED) after local surgery and/or radiation. In both, as well as in complete responders to chemotherapy, minimal residual disease (m.r.d.) likely continues to be present. Recent data suggest that 'biological' therapy (immunomodulators and/or retinoids with or without hormone therapy), might be suitable to be successfully tested in these patients as maintenance treatment given soon after local intervention or chemotherapy.

High-Resolution Genomic Profiling Reveals Association of Chromosomal Aberrations on 1q and 16p with Histologic and Genetic Subgroups of Invasive Breast Cancer

PURPOSE

Invasive ductal carcinoma and invasive lobular carcinoma (ILC) represent the major histologic subtypes of invasive breast cancer. They differ with regard to presentation, metastatic spread, and epidemiologic features. To elucidate the genetic basis of these differences, we analyzed copy number imbalances that differentiate the histologic subtypes.

EXPERIMENTAL DESIGN

High-resolution genomic profiling of 40 invasive breast cancers using matrix-comparative genomic hybridization with an average resolution of 0.5 Mb was conducted on bacterial artificial chromosome microarrays. The data were subjected to classification and unsupervised hierarchical cluster analyses. Expression of candidate genes was analyzed in tumor samples.

RESULTS

The highest discriminating power was achieved when combining the aberration patterns of chromosome arms 1q and 16p, which were significantly more often gained in ILC. These regions were further narrowed down to subregions 1q24.2-25.1, 1q25.3-q31.3, and 16p11.2. Located within the candidate gains on 1q are two genes, FMO2 and PTGS2, known to be overexpressed in ILC relative to invasive ductal carcinoma. Assessment of four candidate genes on 16p11.2 by real-time quantitative PCR revealed significant overexpression of FUS and ITGAX in ILC with 16p copy number gain. Unsupervised hierarchical cluster analysis identified three molecular subgroups that are characterized by different aberration patterns, in particular concerning gain of MYC (8q24) and the identified candidate regions on 1q24.2-25.1, 1q25.3-q31.3, and 16p11.2. These genetic subgroups differed with regard to histology, tumor grading, frequency of alterations, and estrogen receptor expression.

CONCLUSIONS

Molecular profiling using bacterial artificial chromosome arrays identified DNA copy number imbalances on 1q and 16p as significant classifiers of histologic and molecular subgroups.

Current directions for COX-2 inhibition in breast cancer

Chemotherapy is effective against breast cancer. COX-2 has been implicated in the progression and angiogenesis of cancers. Celecoxib, a cyclooxygenase type 2 (COX-2) inhibitor, has both apoptotic and antiangiogenic activities, and may be of use in treatment of breast tumors which overexpress the COX-2 enzyme. Preliminary clinical trials have shown that the combination of chemotherapy with celecoxib has minimal additional toxicity and it may enhance the effects of the chemotherapy. Beside chemotherapy, celecoxib may promulgate the effect of aromatase inhibitor in breast cancer cells. Animal studies have shown that there are fewer and smaller tumors treated by combining exemestane and celecoxib. Larger clinical trials should be initiated to study the potential anti-cancer effects of celecoxib in breast cancer.

Study of COX-2, Ki67, and p53 expression to predict effectiveness of 5-flurouracil, epirubicin and cyclophosphamide with celecoxib treatment in breast cancer patients

BACKGROUND

Cyclooxygenase-2 (COX-2) affects cell proliferation, apoptosis, and metastasis of breast cancer, and may also be involved in tumor angiogenesis through vascular endothelial growth factor. Ki67 and p53 are common markers of proliferation and apoptosis in tumor cells. This study investigated the change in expression of COX-2, Ki67, and p53 in solid tumors after the administration of chemotherapeutic drugs.

MATERIALS AND METHODS

Fifty patients were eligible to be treated with preoperative 5-fluorouracil, epirubicin, and cyclophosphamide, with celecoxib (FECC). Tumor tissue samples from 10 patients who, diagnosed with invasive ductal carcinoma, completed chemotherapy were examined immunohistochemically for COX-2, Ki67, and p53.

RESULTS

From the 60% of patients who expressed COX-2 and 90% who expressed Ki67 and p53 before treatment, 90% of patients revealed a lower intensity staining for each marker after FECC treatment. However, changes in expression of the three markers did not significantly correlate with tumor size, grade, axillary lymph node status. Immunostained slides clearly showed that the diaminobenzidine intensity was markedly reduced after the three-cycle FECC treatment, which implied the combined regimens be effective to the cancer patients.

CONCLUSIONS

This study demonstrates a novel relationship between COX-2, Ki67, and p53 expression of human breast invasive ductal carcinomas. This functional relationship provides support for a potential therapeutic role of COX-2 inhibitors in human breast cancer.