Lung cancer chemoprevention with celecoxib in former smokers

High Omega-3, Low Omega-6 Diet With Fish Oil for Men With Prostate Cancer on Active Surveillance: The CAPFISH-3 Randomized Clinical Trial

PURPOSE

Men on active surveillance (AS) for prostate cancer are extremely interested in dietary changes or supplements to prevent progression of their disease. We sought to determine whether a high omega-3, low omega-6 fatty acid diet with fish oil capsules (D + FO) decreases proliferation (Ki-67) in prostate biopsies in men with prostate cancer on AS over a 1-year time period.

METHODS

In this phase II, prospective randomized trial, men (N = 100) with grade group 1 or 2 prostate cancer who elected AS were randomly assigned to the D + FO or a control group. Same-site prostate biopsies were obtained at baseline and 1 year. The primary end point was the change in Ki-67 index from baseline to 1 year from same-site biopsies compared between the groups.

RESULTS

The Ki-67 index decreased in the D + FO group by approximately 15% from baseline to 1 year (1.34% at baseline, 1.14% at 1 year) and increased in the control group by approximately 24% from baseline to 1 year (1.23% at baseline, 1.52% at 1 year), resulting in a statistically significant difference in the change of Ki-67 index between the groups (95% CI, 2% to 52%, P = .043). There was no significant difference in the secondary outcomes grade group, tumor length, Decipher genomic score, or prostate-specific antigen between the two groups. Four patients in the D + FO group were withdrawn from the trial because of adverse events related to the FO.

CONCLUSION

A high omega-3, low omega-6 diet with FO for 1 year resulted in a significant reduction in Ki-67 index, a biomarker for prostate cancer progression, metastasis, and death. These findings support future phase III trials incorporating this intervention in men on AS.

Carrier-Free Inhalable Dry Microparticles of Celecoxib: Use of the Electrospraying Technique

Upregulation of cyclooxygenase (COX-2) plays an important role in lung cancer pathogenesis. Celecoxib (CLX), a selective COX-2 inhibitor, may have beneficial effects in COVID-19-induced inflammatory storms. The current study aimed to develop carrier-free inhalable CLX microparticles by electrospraying as a dry powder formulation for inhalation (DPI). CLX microparticles were prepared through an electrospraying method using a suitable solvent mixture at two different drug concentrations. The obtained powders were characterized in terms of their morphology, solid state, dissolution behavior, and aerosolization performance. Electrosprayed particles obtained from the ethanol-acetone solvent mixture with a drug concentration of 3 % w/v exhibited the best in vitro aerosolization properties. The value of the fine particle fraction obtained for the engineered drug particles was 12-fold higher than that of the untreated CLX. When the concentration of CLX was increased, a remarkable reduction in FPF was obtained. The smallest median mass aerodynamic diameter was obtained from the electrosprayed CLX at a 3% concentration (2.82 µm) compared to 5% (3.25 µm) and untreated CLX (4.18 µm). DSC and FTIR experiments showed no change in drug crystallinity or structure of the prepared powders during the electrospraying process. The findings of this study suggest that electrospraying has potential applications in the preparation of DPI formulations.

Transethosomal Gel for the Topical Delivery of Celecoxib: Formulation and Estimation of Skin Cancer Progression

The topical delivery of therapeutics is a promising strategy for managing skin conditions. Cyclooxygenase-2 (COX-2) inhibitors showed a possible target for chemoprevention and cancer management. Celecoxib (CXB) is a selective COX-2 inhibitor that impedes cell growth and generates apoptosis in different cell tumors. Herein, an investigation proceeded to explore the usefulness of nano lipid vesicles (transethosomes) (TES) of CXB to permit penetration of considerable quantities of the drug for curing skin cancer. The prepared nanovesicles were distinguished for drug encapsulation efficiency, vesicle size, PDI, surface charge, and morphology. In addition, FT-IR and DSC analyses were also conducted to examine the influence of vesicle components. The optimized formulation was dispersed in various hydrogel bases. Furthermore, in vitro CXB release and ex vivo permeability studies were evaluated. A cytotoxicity study proceeded using A431 and BJ1 cell lines. The expression alteration of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene and DNA damage and fragmentation using qRT-PCR and comet assays were also investigated. Optimized CXB-TES formulation was spherically shaped and displayed a vesicle size of 75.9 ± 11.4 nm, a surface charge of -44.7 ± 1.52 mV, and an entrapment efficiency of 88.8 ± 7.2%. The formulated TES-based hydrogel displayed a sustained in vitro CXB release pattern for 24 h with an enhanced flux and permeation across rat skin compared with the control (free drug-loaded hydrogel). Interestingly, CXB-TES hydrogel has a lower cytotoxic effect on normal skin cells compared with TES suspension and CXB powder. Moreover, the level of expression of the CDKN2A gene was significantly (p ≤ 0.01, ANOVA/Tukey) decreased in skin tumor cell lines compared with normal skin cell lines, indicating that TES are the suitable carrier for topical delivery of CXB to the cancer cells suppressing their progression. In addition, apoptosis demonstrated by comet and DNA fragmentation assays was evident in skin cancer cells exposed to CXB-loaded TES hydrogel formulation. In conclusion, our results illustrate that CXB-TES-loaded hydrogel could be considered a promising carrier and effective chemotherapeutic agent for the management of skin carcinoma.

The Role of IL-6 in Cancer Cell Invasiveness and Metastasis-Overview and Therapeutic Opportunities

Interleukin 6 (IL-6) belongs to a broad class of cytokines involved in the regulation of various homeostatic and pathological processes. These activities range from regulating embryonic development, wound healing and ageing, inflammation, and immunity, including COVID-19. In this review, we summarise the role of IL-6 signalling pathways in cancer biology, with particular emphasis on cancer cell invasiveness and metastasis formation. Targeting principal components of IL-6 signalling (e.g., IL-6Rs, gp130, STAT3, NF-κB) is an intensively studied approach in preclinical cancer research. It is of significant translational potential; numerous studies strongly imply the remarkable potential of IL-6 signalling inhibitors, especially in metastasis suppression.

Resolvin E1 Reduces Tumor Growth in a Xenograft Model of Lung Cancer

Inflammation plays a significant role in carcinogenesis and tumor growth. The current study was designed to test the hypothesis that resolvin E1 (RvE1) and overexpression of the receptor for RvE1 (ERV1) will prevent and/or reverse tumor generation in a gain-of-function mouse model of tumor seeding with lung cancer cells. To measure the impact of enhanced resolution of inflammation on cancer pathogenesis, ERV1-overexpressing transgenic (TG) and wild-type FVB mice were given an injection of 1 × 106 LA-P0297 cells subcutaneously and were treated with RvE1 (100 ng; intraperitoneally) or placebo. To assess the impact of RvE1 as an adjunct to chemotherapy, ERV1-TG and wild-type FVB mice were treated with cisplatin or cisplatin + RvE1. RvE1 significantly prevented tumor growth and reduced tumor size, cyclooxygenase-2, NF-κB, and proinflammatory cytokines in TG animals as compared to wild-type animals. A significant decrease in Ki-67, vascular endothelial growth factor, angiopoietin (Ang)-1, and Ang-2 was also observed in TG animals as compared to wild-type animals. Tumor-associated neutrophils and macrophages were significantly reduced by RvE1 in transgenics (P < 0.001). RvE1 administration with cisplatin led to a significant reduction of tumor volume and reduced cyclooxygenase-2, NF-κB, vascular endothelial growth factor-A, Ang-1, and Ang-2. These data suggest that RvE1 prevents inflammation and vascularization, reduces tumor seeding and tumor size, and, when used as an adjunct to chemotherapy, enhances tumor reduction at significantly lower doses of cisplatin.

The Efficacy and Safety of Celecoxib in Addition to Standard Cancer Therapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The purpose of this meta-analysis was to evaluate the efficacy and safety of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, in addition to standard anticancer therapy. Randomized controlled trials (RCTs) that evaluated the efficacy and safety of celecoxib-combined cancer therapy were systematically searched in PubMed and Embase databases. The endpoints were overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), objective response rate (ORR), disease control rate (DCR), pathological complete response (pCR), and adverse events (AEs). The results of 30 RCTs containing 9655 patients showed limited benefits in celecoxib-combined cancer therapy. However, celecoxib-combined palliative therapy prolonged PFS in epidermal growth factor receptor (EGFR) wild-type patients (HR = 0.57, 95%CI = 0.35–0.94). Moreover, despite a slight increase in thrombocytopenia (RR = 1.35, 95%CI = 1.08–1.69), there was no increase in other toxicities. Celecoxib combined with adjuvant therapy indicated a better OS (HR = 0.850, 95%CI = 0.725–0.996). Furthermore, celecoxib plus neoadjuvant therapy improved the ORR in standard cancer therapy, especially neoadjuvant therapy (overall: RR = 1.13, 95%CI = 1.03–1.23; neoadjuvant therapy: RR = 1.25, 95%CI = 1.09–1.44), but not pCR. Our study indicated that adding celecoxib to palliative therapy prolongs the PFS of EGFR wild-type patients, with good safety profiles. Celecoxib combined with adjuvant therapy prolongs OS, and celecoxib plus neoadjuvant therapy improves the ORR. Thus, celecoxib-combined cancer therapy may be a promising therapy strategy.

Lung cancer: Premalignant biology and medical prevention

Lung cancer (both adenocarcinoma and squamous cell) progress through a series of pre-malignant histologic changes before the development of invasive disease. Each of these carcinogenic cascades is defined by genetic and epigenetic alterations in pulmonary epithelial cells. Additionally, alterations in the immune response, progenitor cell function, mutational burden, and microenvironmental mediated survival of mutated clones contribute to the risk of pre-malignant lesions progressing to cancer. Medical preventions studies have been completed and current and future trials are informed by the improved understanding of pre-malignancy. This will lead to precision chemoprevention trials based on lesional biology and histologic characteristics.

Pulmonary Delivery of Docetaxel and Celecoxib by PLGA Porous Microparticles for Their Synergistic Effects Against Lung Cancer

BACKGROUND

using a combination of chemotherapeutic agents with novel drug delivery platforms to enhance the anticancer efficacy of the drug and minimizing the side effects, is very imperative for lung cancer treatments.

OBJECTIVE

The aim of the present study was to develop, characterize, and optimize porous poly (D, L-lactic-co-glycolic acid) (PLGA) microparticles for simultaneous delivery of docetaxel (DTX) and celecoxib (CXB) through the pulmonary route for lung cancer.

METHODS

Drug-loaded porous microparticles were prepared by an emulsion solvent evaporation method. The impact of various processing and formulation variables including PLGA amount, dichloromethane volume, homogenization speed, polyvinyl alcohol volume and concentration were assessed on entrapment efficiency, mean release time, particle size, mass median aerodynamic diameter, fine particle fraction and geometric standard deviation using a two-level factorial design. An optimized formulation was prepared and evaluated in terms of size and morphology using a scanning electron microscope.

RESULTS

FTIR, DSC, and XRD analysis confirmed drug entrapment and revealed no drug-polymer chemical interaction. Cytotoxicity of DTX along with CXB against A549 cells was significantly enhanced compared to DTX and CXB alone and the combination of DTX and CXB showed the greatest synergistic effect at a 1/500 ratio.

CONCLUSION

In conclusion, the results of the present study suggest that encapsulation of DTX and CXB in porous PLGA microspheres with desirable features are feasible and their pulmonary co-administration would be a promising strategy for the effective and less toxic treatment of various lung cancers.

Celecoxib repurposing in cancer therapy: molecular mechanisms and nanomedicine-based delivery technologies

While cancer remains a significant global health problem, advances in cancer biology, deep understanding of its underlaying mechanism and identification of specific molecular targets allowed the development of new therapeutic options. Drug repurposing poses several advantages as reduced cost and better safety compared with new compounds development. COX-2 inhibitors are one of the most promising drug classes for repurposing in cancer therapy. In this review, we provide an overview of the detailed mechanism and rationale of COX-2 inhibitors as anticancer agents and we highlight the most promising research efforts on nanotechnological approaches to enhance COX-2 inhibitors delivery with special focus on celecoxib as the most widely studied agent for chemoprevention or combined with chemotherapeutic and herbal drugs for combating various cancers.

Prostaglandin E2 and Cancer: Insight into Tumor Progression and Immunity

The involvement of inflammation in cancer progression has been the subject of research for many years. Inflammatory milieu and immune response are associated with cancer progression and recurrence. In different types of tumors, growth and metastatic phenotype characterized by the epithelial mesenchymal transition (EMT) process, stemness, and angiogenesis, are increasingly associated with intrinsic or extrinsic inflammation. Among the inflammatory mediators, prostaglandin E2 (PGE2) supports epithelial tumor aggressiveness by several mechanisms, including growth promotion, escape from apoptosis, transactivation of tyrosine kinase growth factor receptors, and induction of angiogenesis. Moreover, PGE2 is an important player in the tumor microenvironment, where it suppresses antitumor immunity and regulates tumor immune evasion, leading to increased tumoral progression. In this review, we describe the current knowledge on the pro-tumoral activity of PGE2 focusing on its role in cancer progression and in the regulation of the tumor microenvironment.

The Biology of Lung Cancer: Development of More Effective Methods for Prevention, Diagnosis, and Treatment

Lung cancer is a heterogeneous disease with abundant genomic alterations. Chronic dysregulated airway inflammation facilitates lung tumorigenesis. In contrast, antitumor host immune responses apply continuous selective pressure on the tumor cells during the evolutionary course of the disease. Unprecedented advances in integrative genomic, epigenomic, and cellular profiling of lung cancer and the tumor microenvironment are enhancing the understanding of pulmonary tumorigenesis. This understanding in turn has led to advancements in lung cancer prevention and early detection strategies, and the development of effective targeted therapies and immunotherapies with survival benefit in selected patients.

Assessing the Current State of Lung Cancer Chemoprevention: A Comprehensive Overview

Chemoprevention of lung cancer is thought to significantly reduce the risk of acquiring these conditions in the subpopulation of patients with underlying health issues, such as chronic obstructive pulmonary disorder and smoking-associated lung problems. Many strategies have been tested in the previous decades, with very few translating to successful clinical trials in specific subpopulations of patients. In this review, we analyze these strategies, as well as new approaches that have emerged throughout the last few years, including synthetic lethality concept and microbiome-induced regulation of lung carcinogenesis. Overall, the continuous effort in the area of lung chemoprevention is required to develop practical therapeutical approaches. Given the inconsistency of results obtained in clinical trials targeting lung cancer chemoprevention in various subgroups of patients that differ in the underlying health condition, race, and gender, we believe that individualized approaches will have more promise than generalized treatments.

Anti-Inflammatory Drugs as Anticancer Agents

Inflammation is strictly associated with cancer and plays a key role in tumor development and progression. Several epidemiological studies have demonstrated that inflammation can predispose to tumors, therefore targeting inflammation and the molecules involved in the inflammatory process could represent a good strategy for cancer prevention and therapy. In the past, several clinical studies have demonstrated that many anti-inflammatory agents, including non-steroidal anti-inflammatory drugs (NSAIDs), are able to interfere with the tumor microenvironment by reducing cell migration and increasing apoptosis and chemo-sensitivity. This review focuses on the link between inflammation and cancer by describing the anti-inflammatory agents used in cancer therapy, and their mechanisms of action, emphasizing the use of novel anti-inflammatory agents with significant anticancer activity.

Treatment of Metastatic or High-Risk Solid Cancer Patients by Targeting the Immune System and/or Tumor Burden: Six Cases Reports

This article summarizes the histories of six patients with different solid tumors treated with a new strategy based on tumor burden reduction and immune evasion as potential targets. All six patients were at a high risk of relapse and were likely to have a minimal residual disease following conventional therapy: biochemical recurrence (BCR) following radical prostatectomy (RP) (two prostate cancers patients), removal of distant metastases (one colorectal and one breast cancer), and complete response (CR) of distant metastases to conventional therapy (one breast cancer and one esophageal–gastric junction cancer). Four of the patients, two after RP and BCR, one after removal of a single pulmonary metastasis from breast cancer, and one after CR to chemotherapy of peritoneal metastases and ascites from an esophageal–gastric junction primary cancer, regularly received cycles of a new drug schedule with the aim of inhibiting immune suppression (IT). In these four patients, preliminary laboratory tests of peripheral blood suggested an interleukin (IL)-2/IL-12 mediated stimulation of cellular immune response with a concomitant decrease in vascular endothelial growth factor (VEGF) immune suppression. The fifth case was a breast cancer patient with distant metastases in CR, while receiving beta-interferon and interleukin-2 in addition to conventional hormone therapy. To date, all five patients are alive and doing well and they have been unexpectedly disease-free for 201 and 78 months following BCR, 28 months following the removal of a single pulmonary metastases, 32 months following CR to chemotherapy of peritoneal metastases and ascites, and 140 months following diagnosis of multiple bone metastases, respectively. The sixth patient, who had colorectal cancer and multiple synchronous liver metastases and underwent nine surgical interventions for metastatic disease, although not disease-free, is doing well 98 months after primary surgery. Our six cases reports can be interpreted with the hypothesis that immune manipulation and/or a concomitant low tumor burden favored their clinical outcome.

A Pilot Study of a Grape Seed Procyanidin Extract for Lung Cancer Chemoprevention

Grape seed procyanidin extract (GSE) had been reported to exert antineoplastic properties in preclinical studies. A modified phase I, open-label, dose-escalation clinical study was conducted to evaluate the safety, tolerability, MTD, and potential chemopreventive effects of leucoselect phytosome (LP), a standardized GSE complexed with soy phospholipids to enhance bioavailability, in heavy active and former smokers. Eight subjects ages 46-68 years were enrolled into the study and treated with escalating oral doses of LP for 3 months. Bronchoscopies with bronchoalveolar lavage and bronchial biopsies were performed before and after 3 months of LP treatment. Hematoxylin and eosin stain for histopathology grading and IHC examination for Ki-67 proliferative labeling index (Ki-67 LI) were carried out on serially matched bronchial biopsy samples from each subject to determine responses to treatment. Two subjects were withdrawn due to issues unrelated to the study medication, and a total of 6 subjects completed the full study course. In general, 3 months of LP, reaching the highest dose per study protocol was well tolerated and no dosing adjustment was necessary. Such a treatment regimen significantly decreased bronchial Ki-67 LI by an average of 55% (P = 0.041), with concomitant decreases in serum miR-19a, -19b, and -106b, which were oncomirs previously reported to be downregulated by GSE, including LP, in preclinical studies. In spite of not reaching the original enrollment goal of 20, our findings nonetheless support the continued clinical translation of GSE as an antineoplastic and chemopreventive agent against lung cancer.

Premalignant lesions of squamous cell carcinoma of the lung: The molecular make-up and factors affecting their progression

Squamous cell carcinoma (SCC), one of the most common forms of lung cancer, shows accelerated progression and aggressive growth and usually is observed at advanced stages. SCC originates from morphological changes in the bronchial epithelium that occur during chronic inflammation: basal cell hyperplasia, squamous metaplasia, and dysplasia I-III. However, the process is not inevitable; it can be stopped at any stage, remain in the stable state indefinitely and either progress or regress. The reasons and mechanisms of different scenarios of the evolution of premalignant lesions in the respiratory epithelium are not fully understood. In this review, we summarized the literature data (including our own data) regarding genetic, epigenetic, transcriptomic and proteomic profiles of the premalignant lesions and highlighted factors (environmental causes, inflammation, and gene polymorphism) that may govern their progression or regression. In conclusion, we reviewed strategies for lung cancer prevention and proposed new models and research directions for studying premalignant lesions and developing new tools to predict the risk of their malignant transformation.

Modulation of genomic and epigenetic end-points by celecoxib

Celecoxib, a nonsteroidal anti-inflammatory drug that selectively targets cyclooxygenase-2, is a promising cancer chemopreventive agent. However, safety concerns have been raised in clinical trials evaluating its ability to prevent colorectal adenomas. The rationale for the herein reported studies was to analyze genomic and epigenetic end-points aimed at investigating both the chemopreventive properties of celecoxib towards cigarette smoke-associated molecular alterations and its possible adverse effects. We carried out three consecutive studies in mice treated with either smoke and/or celecoxib. Study 1 investigated early DNA alterations (DNA adducts, oxidative DNA damage, and systemic genotoxic damage) and epigenetic alterations (expression of 1,135 microRNAs) in lung and blood of Swiss H mice; Study 2 evaluated the formation of DNA adducts in lung, liver, and heart; and Study 3 evaluated the expression of microRNAs in 10 organs and 3 body fluids of ICR (CD-1) mice. Surprisingly, the oral administration of celecoxib to smoke-free mice resulted in the formation of DNA adducts in both lung and heart and in dysregulation of microRNAs in mouse organs and body fluids. On the other hand, celecoxib attenuated smoke-related DNA damage and dysregulation of microRNA expression. In conclusion, celecoxib showed pleiotropic properties and multiple mechanisms by counteracting the molecular damage produced by smoke in a variety of organs and body fluids. However, administration of celecoxib to non-smoking mice resulted in evident molecular alterations, also including DNA and RNA alterations in the heart, which may bear relevance in the pathogenesis of the cardiovascular adverse effects of this drug.

Drug-Clinical Agent Molecular Hybrid: Synthesis of Diaryl(trifluoromethyl)pyrazoles as Tubulin Targeting Anticancer Agents

Twenty-three combretastatin A-4 (CA-4) analogues were synthesized by judiciously incorporating a functional N-heterocyclic motif present in Celecoxib (a marketed drug) while retaining essential pharmacophoric features of CA-4. Combretastatin-(trifluoromethyl)pyrazole hybrid analogues, i.e., 5-trimethoxyphenyl-3-(trifluoromethyl)pyrazoles with a variety of relevantly substituted aryls and heteroaryls at 1-position were considered as potential tubulin polymerization inhibitors. The cytotoxicity of the compounds was evaluated using MCF-7 cells. Analog 23 (C-23) was found to be the most active among the tested compounds. It showed pronounced cytotoxicity against HeLa, B16F10, and multidrug-resistant mammary tumor cells EMT6/AR1. Interestingly, C-23 displayed significantly lower toxicity toward noncancerous cells, MCF10A and L929, than their cancerous counterparts, MCF-7 and B16F10, respectively. C-23 depolymerized interphase microtubules, disrupted mitotic spindle formation, and arrested MCF-7 cells at mitosis, leading to cell death. C-23 inhibited the assembly of tubulin in vitro. C-23 bound to tubulin at the colchicine binding site and altered the secondary structures of tubulin. The data revealed the importance of (trimethoxyphenyl)(trifluoromethyl)pyrazole as a cis-restricted double bond-alternative bridging motif, and carboxymethyl-substituted phenyl as ring B for activities and interaction with tubulin. The results indicated that the combretastatin-(trifluoromethyl)pyrazole hybrid class of analogues has the potential for further development as anticancer agents.

Perioperative events influence cancer recurrence risk after surgery

Surgery is a mainstay treatment for patients with solid tumours. However, despite surgical resection with a curative intent and numerous advances in the effectiveness of (neo)adjuvant therapies, metastatic disease remains common and carries a high risk of mortality. The biological perturbations that accompany the surgical stress response and the pharmacological effects of anaesthetic drugs, paradoxically, might also promote disease recurrence or the progression of metastatic disease. When cancer cells persist after surgery, either locally or at undiagnosed distant sites, neuroendocrine, immune, and metabolic pathways activated in response to surgery and/or anaesthesia might promote their survival and proliferation. A consequence of this effect is that minimal residual disease might then escape equilibrium and progress to metastatic disease. Herein, we discuss the most promising proposals for the refinement of perioperative care that might address these challenges. We outline the rationale and early evidence for the adaptation of anaesthetic techniques and the strategic use of anti-adrenergic, anti-inflammatory, and/or antithrombotic therapies. Many of these strategies are currently under evaluation in large-cohort trials and hold promise as affordable, readily available interventions that will improve the postoperative recurrence-free survival of patients with cancer.

Autophagy activated by the c-Jun N-terminal kinase-mediated pathway protects human prostate cancer PC3 cells from celecoxib-induced apoptosis

The aim of the present study was to investigate the role of autophagy in celecoxib-induced apoptosis in human hormone-insensitive prostate cancer cell line PC3 cells and to explore the underlying molecular mechanism leading to autophagic activation. A cell viability assay was applied to investigate the effect of various concentrations of celecoxib (0, 40, 60, 80, 100 and 120 µmol/l) on PC3 cells for 24 and 48 h, respectively. The 50% inhibitory concentration of celecoxib for 24 h was chosen for subsequent experiments. Annexin V-fluorescein isothiocyanate/propidium iodide double staining flow cytometry, as well as caspase 3 and poly (ADP-ribose) polymerase proteins detected by western blotting, were applied to analyze cellular apoptosis induced by celecoxib. Ultrastructural cellular changes observed by transmission electron microscopy and the level of LC-3 II and P62 detected by western blotting were used to determine the activation of autophagy. It was demonstrated that celecoxib induced apoptosis and activated autophagy in PC3 cells in a dose- and time-dependent manner. Furthermore, flow cytometry and western blotting were applied to elucidate whether the role of autophagy in celecoxib-induced apoptosis is protective or destructive. Blockade of autophagy markedly increased apoptosis, suggesting that celecoxib-activated autophagy was cytoprotective. Additionally, c-jun-N-terminal kinase (JNK) was demonstrated to have a role in autophagic activation, and suppression of JNK was able to reduce autophagy and increase apoptosis. In conclusion, the results of the present study indicate that celecoxib induces apoptosis in PC3 cells; however, celecoxib also activates JNK-mediated autophagy, which exerts cytoprotective effects in prostate cancer PC3 cells. Blockade of autophagy via the JNK-mediated pathway may provide a promising strategy for prostate cancer therapy.

A stratified randomized double-blind phase II trial of celecoxib for treating patients with cervical intraepithelial neoplasia: The potential predictive value of VEGF serum levels: An NRG Oncology/Gynecologic Oncology Group study

PURPOSE

To examine the effect of celecoxib on cervical intraepithelial neoplasia 3 (CIN 3). This is a NRG Oncology/Gynecologic Oncology Group study with translational biomarkers.

PATIENTS AND METHODS

Patients with CIN 3 were randomized to celecoxib 400mg once daily (67 patients) or placebo (63 patients) for 14-18weeks. The primary outcome measure was histologic regression. A test of equal probabilities of success between two therapies was conducted, using Fisher's Exact Test at alpha=10% and 90% power when the treatment arm boosted the probability of success by 30%. Translational analysis included cervical tissue HPV genotyping, COX-2 expression in biopsies, and serum celecoxib and VEGF levels.

RESULTS

In primary analysis, histologic regression was not significantly higher in the celecoxib group (40%) than in the placebo group (34.1%). However, exploratory analyses suggest patients with high serum VEGF levels exhibited greater regression in the celecoxib arm (47.3%) than in the placebo arm (14.3%). Regression rates were similar by treatment group in patients with low VEGF. VEGF levels increased over time in the placebo group, but remained the same in the treatment group. COX-2 expression in cervical biopsies declined from pre-treatment to the end of treatment with celecoxib; it did not change with placebo.

CONCLUSIONS

Celecoxib at 400mg once daily for 14-18weeks did not significantly decrease the severity of CIN 3 compared with placebo except, possibly, in subjects with high baseline VEGF. Therefore, serum VEGF levels might identify patients who may benefit from celecoxib or other therapies, personalizing future chemoprevention trials for CIN 3.

Celecoxib increases lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study investigates the impact of celecoxib on the expression of intercellular adhesion molecule 1 (ICAM-1) and cancer cell lysis by lymphokine-activated killer (LAK) cells. Celecoxib, but not other structurally related selective COX-2 inhibitors (i.e., etoricoxib, rofecoxib, valdecoxib), was found to cause a substantial upregulation of ICAM-1 protein levels. Likewise, ICAM-1 mRNA expression was increased by celecoxib. Celecoxib enhanced the susceptibility of cancer cells to be lysed by LAK cells with the respective effect being reversed by a neutralizing ICAM-1 antibody. In addition, enhanced killing of celecoxib-treated cancer cells was reversed by preincubation of LAK cells with an antibody to lymphocyte function associated antigen 1 (LFA-1), suggesting intercellular ICAM-1/LFA-1 crosslink as crucial event within this process. Finally, celecoxib elicited no significant increase of LAK cell-mediated lysis of non-tumor bronchial epithelial cells, BEAS-2B, associated with a far less ICAM-1 induction as compared to cancer cells. Altogether, our data demonstrate celecoxib-induced upregulation of ICAM-1 on lung cancer cells to be responsible for intercellular ICAM-1/LFA-1 crosslink that confers increased cancer cell lysis by LAK cells. These findings provide proof for a novel antitumorigenic mechanism of celecoxib.

Grape Seed Procyanidin Extract Mediates Antineoplastic Effects against Lung Cancer via Modulations of Prostacyclin and 15-HETE Eicosanoid Pathways

Grape seed procyanidin extract (GSE) has been reported to exert antineoplastic properties via the inhibition of cyclooxygenase-2 (COX-2)/prostaglandin E₂ (PGE₂) eicosanoid pathways. In addition, ample data link carcinogenesis to inflammatory events involving other major eicosanoid metabolic pathways, including prostacyclin (PGI₂) and 15-hydroxyeicosatetraenoic acid (15-HETE). We therefore evaluated the effects of GSE on prostacyclin synthase (PTGIS)/PGI₂ and 15-lipoxigenase-2 (15-LOX-2)/15-HETE productions by human lung premalignant and malignant cells and correlated the findings with antiproliferative or proapoptotic effects of GSE. The effects of GSE on PGI₂ and 15-HETE productions by human bronchoalveolar lavage (BAL) cells ex vivo were also determined. We further evaluated the bioactivity of oral administration of leucoselect phytosome (a standardized GSE) in the lungs of subjects participating in a lung cancer chemoprevention trial, by comparing the antiproliferative effects of coculturing matched pre- versus posttreatment BAL fluids with lung premalignant and malignant cells. GSE significantly increased PGI₂ (as measured by 6-keto PGF1α) and 15-HETE productions by these cells. Transfections of PTGIS or 15-LOX-2-specific siRNA partially abrogated the antiproliferative or proapoptotic effects of GSE in lung premalignant and malignant cells, respectively. GSE also increased PTGIS and inhibition of caspase-3, and transfection of 15-LOX-2 siRNA abrogated the GSE-induced apoptosis in A549 cells. In addition, culture supernatants from ex vivo GSE-treated baseline BAL cells, as well as BAL fluids from subjects treated with leucoselect phytosome, significantly decreased proliferations of lung premalignant and malignant cells. Our findings support the continued investigation of GSE as an anti-neoplastic and chemopreventive agent against lung cancer. Cancer Prev Res; 9(12); 925-32. ©2016 AACR.

Pharmacological Modulation of Lung Carcinogenesis in Smokers: Preclinical and Clinical Evidence

Many drugs in common use possess pleiotropic properties that make them capable of interfering with carcinogenesis mechanisms. We discuss here the ability of pharmacological agents to mitigate the pulmonary carcinogenicity of mainstream cigarette smoke. The evaluated agents include anti-inflammatory drugs (budesonide, celecoxib, aspirin, naproxen, licofelone), antidiabetic drugs (metformin, pioglitazone), antineoplastic agents (lapatinib, bexarotene, vorinostat), and other drugs and supplements (phenethyl isothiocyanate, myo-inositol, N-acetylcysteine, ascorbic acid, berry extracts). These drugs have been evaluated in mouse models mimicking interventions either in current smokers or in ex-smokers, or in prenatal chemoprevention. They display a broad spectrum of activities by attenuating either smoke-induced preneoplastic lesions or benign tumors and/or malignant tumors. Together with epidemiological data, these findings provide useful information to predict the potential effects of pharmacological agents in smokers.

Inhibition of 11β-Hydroxysteroid Dehydrogenase Type II Suppresses Lung Carcinogenesis by Blocking Tumor COX-2 Expression as Well as the ERK and mTOR Signaling Pathways

Lung cancer is by far the leading cause of cancer death. Early diagnosis and prevention remain the best approach to reduce the overall morbidity and mortality. Experimental and clinical evidence have shown that cyclooxygenase-2 (COX-2) derived prostaglandin E₂ (PGE2) contributes to lung tumorigenesis. COX-2 inhibitors suppress the development and progression of lung cancer. However, increased cardiovascular risks of COX-2 inhibitors limit their use in chemoprevention of lung cancers. Glucocorticoids are endogenous and potent COX-2 inhibitors, and their local actions are down-regulated by 11β–hydroxysteroid dehydrogenase type II (11ßHSD2)-mediated metabolism. We found that 11βHSD2 expression was increased in human lung cancers and experimental lung tumors. Inhibition of 11βHSD2 activity enhanced glucocorticoid-mediated COX-2 inhibition in human lung carcinoma cells. Furthermore, 11βHSD2 inhibition suppressed lung tumor growth and invasion in association with increased tissue active glucocorticoid levels, decreased COX-2 expression, inhibition of ERK and mTOR signaling pathways, increased tumor endoplasmic reticulum stress as well as increased lifespan. Therefore, 11βHSD2 inhibition represents a novel approach for lung cancer chemoprevention and therapy by increasing tumor glucocorticoid activity, which in turn selectively blocks local COX-2 activity and/or inhibits the ERK and mTOR signaling pathways.

Combinations of indole-3-carbinol and silibinin suppress inflammation-driven mouse lung tumorigenesis by modulating critical cell cycle regulators

Chronic inflammation is an important risk factor for lung cancer. Therefore, identification of chemopreventive agents that suppress inflammation-driven lung cancer is indispensable. We studied the efficacy of combinations of indole-3-carbinol (I3C) and silibinin (Sil), 20 µmol/g diet each, against mouse lung tumors induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and driven by lipopolysaccharide (LPS), a potent inflammatory agent and constituent of tobacco smoke. Mice treated with NNK + LPS developed 14.7±4.1 lung tumors/mouse, whereas mice treated with NNK + LPS and given combinations of I3C and Sil had 7.1±4.5 lung tumors/mouse, corresponding to a significant reduction of 52%. Moreover, the number of largest tumors (>1.0mm) was significantly reduced from 6.3±2.9 lung tumors/mouse in the control group to 1.0±1.3 and 1.6±1.8 lung tumors/mouse in mice given I3C + Sil and I3C alone, respectively. These results were paralleled by significant reductions in the level of proinflammatory and procarcinogenic proteins (pSTAT3, pIκBα and COX-2) and proteins that regulate cell proliferation (pAkt, cyclin D1, CDKs 2, 4, 6 and pRB). Further studies in premalignant bronchial cells showed that the antiproliferative effects of I3C + Sil were higher than the individual compounds and these effects were mediated by targeting cyclin D1, CDKs 2, 4 and 6 and pRB. I3C + Sil suppressed cyclin D1 by reducing its messenger RNA level and by enhancing its proteasomal degradation. Our results showed the potential lung cancer chemopreventive effects of I3C + Sil in smokers/former smokers with chronic pulmonary inflammatory conditions.

PDE5 inhibitors enhance celecoxib killing in multiple tumor types

The present studies determined whether clinically relevant phosphodiesterase 5 (PDE5) inhibitors interacted with a clinically relevant NSAID, celecoxib, to kill tumor cells. Celecoxib and PDE5 inhibitors interacted in a greater than additive fashion to kill multiple tumor cell types. Celecoxib and sildenafil killed ex vivo primary human glioma cells as well as their associated activated microglia. Knock down of PDE5 recapitulated the effects of PDE5 inhibitor treatment; the nitric oxide synthase inhibitor L-NAME suppressed drug combination toxicity. The effects of celecoxib were COX2 independent. Over-expression of c-FLIP-s or knock down of CD95/FADD significantly reduced killing by the drug combination. CD95 activation was dependent on nitric oxide and ceramide signaling. CD95 signaling activated the JNK pathway and inhibition of JNK suppressed cell killing. The drug combination inactivated mTOR and increased the levels of autophagy and knock down of Beclin1 or ATG5 strongly suppressed killing by the drug combination. The drug combination caused an ER stress response; knock down of IRE1α/XBP1 enhanced killing whereas knock down of eIF2α/ATF4/CHOP suppressed killing. Sildenafil and celecoxib treatment suppressed the growth of mammary tumors in vivo. Collectively our data demonstrate that clinically achievable concentrations of celecoxib and sildenafil have the potential to be a new therapeutic approach for cancer.

LLW-3-6 and celecoxib impacts growth in prostate cancer cells and subcellular localization of COX-2

The proliferation in human prostate carcinomas, PC3 and MDA-PCa-2b, was analyzed for cells treated with LLW-3-6 and celecoxib in the presence and absence of sulfasalazine. LLW-3-6 was more potent than celecoxib at mediating a dose-dependent reduction of viable PC3 cells. Co-treatment with a non-lethal dose of sulfasalazine diminished the potency of both drugs in this cell line. The effects of the drugs in MDA-PCa-2b cells were less significant than those observed in the PC3 cells. Localization of COX-2 in LLW-3-6- and CBX-treated PC3 cells is consistent with protein aggregation known for cells responding to stress stimuli. To complement this, an analysis of the theoretical binding interactions of LLW-3-6 was completed to illustrate the potential of LLW-3-6 to bind to COX-2 in a manner similar to that of celecoxib. Studies to further define the mechanism of action for LLW-3-6 are ongoing.

Preclinical evaluation of 4-[3,5-bis(2-chlorobenzylidene)-4-oxo-piperidine-1-yl]-4-oxo-2-butenoic acid, in a mouse model of lung cancer xenograft

BACKGROUND AND PURPOSE

4-[3,5-Bis(2-chlorobenzylidene)-4-oxo-piperidine-1-yl]-4-oxo-2-butenoic acid CLEFMA is a new anti-cancer molecule. Here, we investigated changes in apoptosis and inflammatory markers during CLEFMA-induced tumour suppression.

EXPERIMENTAL APPROACH

Lung adenocarcinoma H441 and A549, and normal lung fibroblast CCL151 cell lines were used, along with a xenograft model of H441 cells implanted in mice. Tumour tissues were analysed by immunoblotting, immunohistochemistry and/or biochemical assays. The ex vivo results were confirmed by performing selected assays in cultured cells.

KEY RESULTS

CLEFMA-induced cell death was associated with cleavage of caspases 3/9 and PARP. In vivo, CLEFMA treatment resulted in a dose-dependent suppression of tumour growth and (18) F-fluorodeoxyglucose uptake in tumours, along with a reduction in the expression of the proliferation marker Ki-67. In tumour tissue homogenates, the anti-apoptotic markers (cellular inhibitor of apoptosis protein-1(cIAP1), Bcl-xL, Bcl-2, and survivin) were inhibited and the pro-apoptotic Bax and BID were up-regulated. Further, CLEFMA decreased translocation of phospho-p65-NF-κB into the nucleus. In vitro, it inhibited the DNA-binding and transcriptional activity of NF-κB. It also reduced the expression of COX-2 in tumours and significantly depressed serum TNF-α and IL-6 levels. These effects of CLEFMA were accompanied by a reduced transcription and/or translation of the invasion markers VEGF, MMP9, MMP10, Cyclin D1 and ICAM-1.

CONCLUSIONS AND IMPLICATIONS

Overall, CLEFMA inhibited growth of lung cancer xenografts and this tumour suppression was associated with NF-κB-regulated anti-inflammatory and anti-metastatic effects.

TREM-1 is induced in tumor associated macrophages by cyclo-oxygenase pathway in human non-small cell lung cancer

It is increasingly recognized that the tumor microenvironment plays a critical role in the initiation and progression of lung cancer. In particular interaction of cancer cells, macrophages, and inflammatory response in the tumor microenvironment has been shown to facilitate cancer cell invasion and metastasis. The specific molecular pathways in macrophages that immunoedit tumor growth are not well defined. Triggering receptor expressed on myeloid cells 1 (TREM-1) is a member of the super immunoglobulin family expressed on a select group of myeloid cells mainly monocyte/macrophages. Recent studies suggest that expression of TREM-1 in tumors may predict cancer aggressiveness and disease outcomes in liver and lung cancer however the mechanism of TREM-1 expression in the setting of cancer is not defined. In this study we demonstrate that tumor tissue from patients with non-small cell lung cancer show an increased expression of TREM-1 and PGE₂. Immunohistochemistry and immunofluorescence confirmed that the expression of TREM-1 was selectively seen in CD68 positive macrophages. By employing an in vitro model we confirmed that expression of TREM-1 is increased in macrophages that are co-cultured with human lung cancer cells. Studies with COX-2 inhibitors and siCOX-2 showed that expression of TREM-1 in macrophages in tumor microenvironment is dependent on COX-2 signaling. These studies for the first time define a link between tumor COX-2 induction, PGE₂ production and expression of TREM-1 in macrophages in tumor microenvironment and suggest that TREM-1 might be a novel target for tumor immunomodulation.

Chemoprevention Trial Feasibility Using Botanicals in Exceptionally High Risk Populations for Lung Cancer

While chemoprevention with botanicals shows promise in reducing cancer risk, recruitment and retention of participants for trials continues to be costly and presents unique challenges. Knowledge of interest, willingness of target populations and evaluation of design challenges are critical to improve accrual in these chemoprevention trials.

OBJECTIVE

The study assessed interest and willingness of former smokers to participate in a chemoprevention trial using a botanical agent.

METHODS

An introductory letter and survey instrument were mailed to 609 consecutive, former heavy smokers, with no cancer, from a database of 826 subjects at the Moffitt Cancer Center.

RESULTS

202 (40.4%) subjects returned completed surveys. 92-96% reported interest in receiving free lung exams and knowing their lung cancer risk. 88% were interested in participating in a trial evaluating a botanical agent for lung cancer prevention. Over 92% of subjects reported willingness to comply with study requirements; multiple blood draws and trips to the Center, spiral CTs and chest x-rays. Subjects were relatively less enthusiastic (73-79%) about bronchoscopy, taking multiple study agents and assignment to placebo arm.

CONCLUSIONS

Our study strongly suggests feasibility, highlights potential challenges and the significant interest and willingness of this exceptionally high risk population to participate in chemoprevention trials.

Immunohistochemical quantification of the vitamin B12 transport protein (TCII), cell surface receptor (TCII-R) and Ki-67 in human tumor xenografts

BACKGROUND/AIM

Cancer cells have an essential demand for vitamin B12 (cobalamin) to enable cellular replication. The present pilot study quantified the immunohistochemical expression of vitamin B12 transport protein (Transcobalamin II; TCII), cell surface receptor (Transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in human tumor xenografts.

MATERIALS AND METHODS

Tissue microarray slides containing 34 xenograft tumor tissues were immunohistochemically stained using TCN2 (anti-TCII), CD320 (anti-TCII-R) and MIB-1 (anti-Ki-67) antibodies. Representatively stained areas of all slides were digitally imaged and protein expression was quantified using ImageJ software plugins.

RESULTS

All xenograft tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Correlation between TCII/TCII-R and Ki-67 expression was not significant in xenograft tissues.

CONCLUSION

Proliferating cancer cells express measurable levels of TCII and TCII-R. Immunohistochemical quantification of these markers may be useful as a tool for detection of tumors, tailored selection of anti-tumor therapies and surveillance for evidence of recurrent disease.

Randomized, double-blind, placebo-controlled, phase III chemoprevention trial of selenium supplementation in patients with resected stage I non-small-cell lung cancer: ECOG 5597

PURPOSE

Selenium has been reported to have chemopreventive benefits in lung cancer. We conducted a double-blind, placebo-controlled trial to evaluate the incidence of second primary tumors (SPTs) in patients with resected non-small-cell lung cancer (NSCLC) receiving selenium supplementation.

PATIENTS AND METHODS

Patients with completely resected stage I NSCLC were randomly assigned to take selenized yeast 200 μg versus placebo daily for 48 months. Participation was 6 to 36 months postoperatively and required a negative mediastinal node biopsy, no excessive vitamin intake, normal liver function, negative chest x-ray, and no other evidence of recurrence.

RESULTS

The first interim analysis in October 2009, with 46% of the projected end points accumulated, showed a trend in favor of the placebo group with a low likelihood that the trial would become positive; thus, the study was stopped. One thousand seven hundred seventy-two participants were enrolled, with 1,561 patients randomly assigned. Analysis was updated in June 2011 with the maturation of 54% of the planned end points. Two hundred fifty-two SPTs (from 224 patients) developed, of which 98 (from 97 patients) were lung cancer (38.9%). Lung and overall SPT incidence were 1.62 and 3.54 per 100 person-years, respectively, for selenium versus 1.30 and 3.39 per 100 person-years, respectively, for placebo (P = .294). Five-year disease-free survival was 74.4% for selenium recipients versus 79.6% for placebo recipients. Grade 1 to 2 toxicity occurred in 31% of selenium recipients and 26% of placebo recipients, and grade ≥ 3 toxicity occurred in less than 2% of selenium recipients versus 3% of placebo recipients. Compliance was excellent. No increase in diabetes mellitus or skin cancer was detected.

CONCLUSION

Selenium was safe but conferred no benefit over placebo in the prevention of SPT in patients with resected NSCLC.

Induction but not inhibition of COX-2 confers human lung cancer cell apoptosis by celecoxib

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Among different structurally related COX-2 inhibitors, only celecoxib was found to cause apoptosis and cell death of human lung cancer cells (IC₅₀ values of 19.96 µM [A549], 12.48 µM [H460], and 41.39 µM [H358]) that was paralleled by a time- and concentration-dependent upregulation of COX-2 and peroxisome proliferator-activated receptor γ (PPARγ) at mRNA and protein levels. Apoptotic death of celecoxib-treated cancer cells was suppressed by the PPARγ antagonist GW9662 and by siRNA targeting PPARγ and, surprisingly, also by the selective COX-2 inhibitor NS-398 and siRNA targeting COX-2. NS-398 (1 µM) was shown to suppress celecoxib-induced COX-2 activity. Among the COX-2-dependent prostaglandins (PG) induced upon celecoxib treatment, PGD₂ and 15-deoxy-Δ¹²,¹⁴-PGJ₂ were found to induce a cytosol-to-nucleus translocation of PPARγ as well as a PPARγ-dependent apoptosis. Celecoxib-elicited PPARγ translocation was inhibited by NS-398. Finally, a COX-2- and PPARγ-dependent cytotoxic action of celecoxib was proven for primary human lung tumor cells. Together, our data demonstrate a proapoptotic mechanism of celecoxib involving initial upregulation of COX-2 and PPARγ and a subsequent nuclear translocation of PPARγ by COX-2-dependent PGs.

COX-Independent Mechanisms of Cancer Chemoprevention by Anti-Inflammatory Drugs

Epidemiological and clinical studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs), including cyclooxygenase (COX)-2 selective inhibitors, reduce the risk of developing cancer. Experimental studies in human cancer cell lines and rodent models of carcinogenesis support these observations by providing strong evidence for the antineoplastic properties of NSAIDs. The involvement of COX-2 in tumorigenesis and its overexpression in various cancer tissues suggest that inhibition of COX-2 is responsible for the chemopreventive efficacy of these agents. However, the precise mechanisms by which NSAIDs exert their antiproliferative effects are still a matter of debate. Numerous other studies have shown that NSAIDs can act through COX-independent mechanisms. This review provides a detailed description of the major COX-independent molecular targets of NSAIDs and discusses how these targets may be involved in their anticancer effects. Toxicities resulting from COX inhibition and the suppression of prostaglandin synthesis preclude the long-term use of NSAIDs for cancer chemoprevention. Furthermore, chemopreventive efficacy is incomplete and treatment often leads to the development of resistance. Identification of alternative NSAID targets and elucidation of the biochemical processes by which they inhibit tumor growth could lead to the development of safer and more efficacious drugs for cancer chemoprevention.

Effect of zileuton and celecoxib on urinary LTE4 and PGE-M levels in smokers

COX-2 and 5-lipoxygenase (5-LO) use arachidonic acid for the synthesis of eicosanoids that have been implicated in carcinogenesis and cardiovascular disease. The ability of celecoxib, a selective COX-2 inhibitor, to redirect arachidonic acid into the 5-LO pathway can potentially reduce its efficacy as a chemopreventive agent and increase the risk of cardiovascular complications. Levels of urinary prostaglandin E metabolite (PGE-M) and leukotriene E4 (LTE4), biomarkers of the COX and 5-LO pathways, are elevated in smokers. Here, we investigated the effects of zileuton, a 5-LO inhibitor, versus zileuton and celecoxib for 6 ± 1 days on urinary PGE-M and LTE4 levels in smokers. Treatment with zileuton led to an 18% decrease in PGE-M levels (P = 0.03); the combination of zileuton and celecoxib led to a 62% reduction in PGE-M levels (P < 0.001). Levels of LTE4 decreased by 61% in subjects treated with zileuton alone (P < 0.001) and were unaffected by the addition of celecoxib. Although zileuton use was associated with a small overall decrease in PGE-M levels, increased PGE-M levels were found in a subset (19 of 52) of subjects. Notably, the addition of celecoxib to the 5-LO inhibitor protected against the increase in urinary PGE-M levels (P = 0.03). In conclusion, zileuton was an effective inhibitor of 5-LO activity resulting in marked suppression of urinary LTE4 levels and possible redirection of arachidonic acid into the COX-2 pathway in a subset of subjects. Combining celecoxib and zileuton was associated with inhibition of both the COX-2 and 5-LO pathways manifested as reduced levels of urinary PGE-M and LTE4.

Lung cancer chemoprevention: current status and future prospects

Lung cancer is the leading cause of cancer death worldwide, making it an attractive disease for chemoprevention. Although avoidance of tobacco use and smoking cessation will have the greatest impact on lung cancer development, chemoprevention could prove to be very effective, particularly in former smokers. Chemoprevention is the use of agents to reverse or inhibit carcinogenesis and has been successfully applied to other common malignancies. Despite prior studies in lung cancer chemoprevention failing to identify effective agents, we now have the ability to identify high-risk populations, and our understanding of lung tumour and premalignant biology continues to advance. There are distinct histological lesions that can be reproducibly graded as precursors of non-small-cell lung cancer and similar precursor lesions exist for adenocarcinoma. These premalignant lesions are being targeted by chemopreventive agents in current trials and will continue to be studied in the future. In addition, biomarkers that predict risk and response to targeted agents are being investigated and validated. In this Review, we discuss the principles of chemoprevention, data from preclinical models, completed clinical trials and observational studies, and describe new treatments for novel targeted pathways and future chemopreventive efforts.

Chemoprevention of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is the most common cause of cancer death in men and women in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk of developing lung cancer compared with lifetime never smokers. Chemoprevention refers to the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention.

METHODS

Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations.

RESULTS

None of the phase 3 trials with the agents β-carotene, retinol, 13-cis-retinoic acid, α-tocopherol, N-acetylcysteine, acetylsalicylic acid, or selenium has demonstrated beneficial and reproducible results. To facilitate the evaluation of promising agents and to lessen the need for a large sample size, extensive time commitment, and expense, surrogate end point biomarker trials are being conducted to assist in identifying the most promising agents for later-stage chemoprevention trials. With the understanding of important cellular signaling pathways and the expansion of potentially important targets, agents (many of which target inflammation and the arachidonic acid pathway) are being developed and tested which may prevent or reverse lung carcinogenesis.

CONCLUSIONS

By integrating biologic knowledge, additional early-phase trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points.

Supercritical fluid technology based large porous celecoxib-PLGA microparticles do not induce pulmonary fibrosis and sustain drug delivery and efficacy for several weeks following a single dose

Although pulmonary dosing of large porous particles has been shown to sustain drug delivery for a few days, there are no reports on safety or long term delivery. In this study we prepared large porous poly(lactide-co-glycolide) (PLGA) microparticles of celecoxib using supercritical fluid pressure-quench technology and demonstrated 4.8-, 15.7-, and 2.1-fold greater drug levels in lung, bronchoalveolar lavage fluid (BAL), and plasma compared to conventional microparticles on day 21 after a single intratracheal dosing of dry powders in A/J mice. Porous particle based delivery was 50.2-, 95.5-, and 7.7-fold higher compared to plain drug in the lung, BAL, and plasma, respectively. Toxicity of the formulations was assessed on day 21 following a fibrosis assessment protocol in A/J mice. There was no significant change in lactate dehydrogenase (LDH), total protein, and total cell counts in the BAL, and soluble collagen levels in the lung tissue following particle or drug treatments. Lung histology indicated no significant hyperplasia, granuloma, or collagen deposition in the treated groups. Chemopreventive potential of celecoxib porous particles was assessed in a benzo[a]pyrene (B[a]P) induced lung cancer model in A/J mice, on day 60 following a single intratracheal dose with or without single intravenous paclitaxel/carboplatin treatment. The combination group was more effective than individual groups, with the inhibition of tumor multiplicity and reduction of vascular endothelial growth factor in the BAL being 70 and 58%, respectively. Thus, large porous celecoxib-PLGA microparticles prepared using supercritical fluid technology exhibited sustained drug delivery and anti-tumor efficacy, without causing any significant toxicity.

Non-small-cell lung cancer: molecular targeted therapy and personalized medicine - drug resistance, mechanisms, and strategies

Targeted therapies for cancer bring the hope of specific treatment, providing high efficacy and in some cases lower toxicity than conventional treatment. Although targeted therapeutics have helped immensely in the treatment of several cancers, like chronic myelogenous leukemia, colon cancer, and breast cancer, the benefit of these agents in the treatment of lung cancer remains limited, in part due to the development of drug resistance. In this review, we discuss the mechanisms of drug resistance and the current strategies used to treat lung cancer. A better understanding of these drug-resistance mechanisms could potentially benefit from the development of a more robust personalized medicine approach for the treatment of lung cancer.