Eicosanoid modulation in advanced lung cancer: cyclooxygenase-2 expression is a positive predictive factor for celecoxib + chemotherapy--Cancer and Leukemia Group B Trial 30203

Tumor-associated macrophages in non-small-cell lung cancer: From treatment resistance mechanisms to therapeutic targets

Non-small cell lung cancer (NSCLC) remains one of the leading causes of cancer-related deaths worldwide. Different treatment approaches are typically employed based on the stage of NSCLC. Common clinical treatment methods include surgical resection, drug therapy, and radiation therapy. However, with the introduction and utilization of immune checkpoint inhibitors, cancer treatment has entered a new era, completely revolutionizing the treatment landscape for various cancers and significantly improving overall patient survival. Concurrently, treatment resistance often poses a critical challenge, with many patients experiencing disease progression following an initial response due to treatment resistance. Increasing evidence suggests that the tumor microenvironment (TME) plays a pivotal role in treatment resistance. Tumor-associated macrophages (TAMs) within the TME can promote treatment resistance in NSCLC by secreting various cytokines activating signaling pathways, and interacting with other immune cells. Therefore, this article will focus on elucidating the key mechanisms of TAMs in treatment resistance and analyze how targeting TAMs can reduce the levels of treatment resistance in NSCLC, providing a comprehensive understanding of the principles and approaches to overcome treatment resistance in NSCLC.

Immune Regulatory Function of Cancer- Associated Fibroblasts in Non-small Cell Lung Cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment and significantly contribute to immune evasion. We investigated the effects of CAFs on the immune function of CD4+ and CD8+ T cells in non-small cell lung cancer (NSCLC).

METHODS

We isolated CAFs and normal fibroblasts (NFs) from tumors and normal lung tissues of NSCLC patients, respectively. CAFs were co-cultured with activated T cells to evaluate their immune regulatory function. We investigated the effect of CAF conditioned medium (CAF-CM) on the cytotoxicity of T cells. CAFs were also co-cultured with activated peripheral blood mononuclear cells and further incubated with cyclooxygenase- 2 (COX2) inhibitors to investigate the potential role of COX2 in immune evasion.

RESULTS

CAFs and NFs were isolated from the lung tissues (n=8) and lymph nodes (n=3) of NSCLC patients. Immune suppressive markers, such as COX2 and programmed death-ligand 1 (PD-L1), were increased in CAFs after co-culture with activated T cells. Interestingly, CAFs promoted the expression of programmed death-1 in CD4+ and CD8+ T cells, and strongly inhibited T cell proliferation in allogenic and autologous pairs of CAFs and T cells. CAF-CM decreased the cytotoxicity of T cells. COX2 inhibitors partially restored the proliferation of CD4+ and CD8+ T cells, and downregulated the expression of COX2, prostaglandin E synthase, prostaglandin E2, and PD-L1 in CAFs.

CONCLUSION

CAFs promote immune evasion by suppressing the function of CD4+ and CD8+ T cells via their effects on COX2 and PD-L1 in NSCLC. The immunosuppressive function of CAFs could be alleviated by COX2 inhibitors.

Orchestral role of lipid metabolic reprogramming in T-cell malignancy

The immune function of normal T cells partially depends on the maneuvering of lipid metabolism through various stages and subsets. Interestingly, T-cell malignancies also reprogram their lipid metabolism to fulfill bioenergetic demand for rapid division. The rewiring of lipid metabolism in T-cell malignancies not only provides survival benefits but also contributes to their stemness, invasion, metastasis, and angiogenesis. Owing to distinctive lipid metabolic programming in T-cell cancer, quantitative, qualitative, and spatial enrichment of specific lipid molecules occur. The formation of lipid rafts rich in cholesterol confers physical strength and sustains survival signals. The accumulation of lipids through de novo synthesis and uptake of free lipids contribute to the bioenergetic reserve required for robust demand during migration and metastasis. Lipid storage in cells leads to the formation of specialized structures known as lipid droplets. The inimitable changes in fatty acid synthesis (FAS) and fatty acid oxidation (FAO) are in dynamic balance in T-cell malignancies. FAO fuels the molecular pumps causing chemoresistance, while FAS offers structural and signaling lipids for rapid division. Lipid metabolism in T-cell cancer provides molecules having immunosuppressive abilities. Moreover, the distinctive composition of membrane lipids has implications for immune evasion by malignant cells of T-cell origin. Lipid droplets and lipid rafts are contributors to maintaining hallmarks of cancer in malignancies of T cells. In preclinical settings, molecular targeting of lipid metabolism in T-cell cancer potentiates the antitumor immunity and chemotherapeutic response. Thus, the direct and adjunct benefit of lipid metabolic targeting is expected to improve the clinical management of T-cell malignancies.

Three-dimensional growth reveals fine-tuning of 5-lipoxygenase by proliferative pathways in cancer

The leukotriene (LT) pathway is positively correlated with the progression of solid malignancies, but the factors that control the expression of 5-lipoxygenase (5-LO), the central enzyme in LT biosynthesis, in tumors are poorly understood. Here, we report that 5-LO along with other members of the LT pathway is up-regulated in multicellular colon tumor spheroids. This up-regulation was inversely correlated with cell proliferation and activation of PI3K/mTORC-2- and MEK-1/ERK-dependent pathways. Furthermore, we found that E2F1 and its target gene MYBL2 were involved in the repression of 5-LO during cell proliferation. Importantly, we found that this PI3K/mTORC-2- and MEK-1/ERK-dependent suppression of 5-LO is also existent in tumor cells from other origins, suggesting that this mechanism is widely applicable to other tumor entities. Our data show that tumor cells fine-tune 5-LO and LT biosynthesis in response to environmental changes repressing the enzyme during proliferation while making use of the enzyme under cell stress conditions, implying that tumor-derived 5-LO plays a role in the manipulation of the tumor stroma to quickly restore cell proliferation.

Stress granules dynamics and promising functions in pancreatic cancer

Stress granules (SGs), non-membrane subcellular organelles made up of non-translational messenger ribonucleoproteins (mRNPs), assemble in response to various environmental stimuli in cancer cells, including pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC) which has a low 5-year survival rate of 10%. The pertinent research on SGs and pancreatic cancer has not, however, been compiled. In this review, we talk about the dynamics of SGs and their positive effects on pancreatic cancer such as SGs promote PDAC viability and repress apoptosis, meanwhile emphasizing the connection between SGs in pancreatic cancer and signature mutations such KRAS, P53, and SMAD4 as well as the functions of SGs in antitumor drug resistance. This novel stress management technique may open the door to better treatment options in the future.

Prognostic implications of prostaglandin E-major urinary metabolite in resected non-small-cell lung cancer

OBJECTIVES

Cyclooxygenase-2-derived prostaglandin E2 (PGE2) is highly involved in the promotion of cancer progression. The end product of this pathway, PGE-major urinary metabolite (PGE-MUM), is a stable metabolite of PGE2 that can be assessed non-invasively and repeatedly in urine samples. The aim of this study was to assess the dynamic changes in perioperative PGE-MUM levels and their prognostic significance in non-small-cell lung cancer (NSCLC).

METHODS

Between December 2012 and March 2017, 211 patients who underwent complete resection for NSCLC were analysed prospectively. PGE-MUM levels in 2 spot urine samples taken 1 or 2 days preoperatively and 3-6 weeks postoperatively were measured using a radioimmunoassay kit.

RESULTS

Elevated preoperative PGE-MUM levels were associated with tumour size, pleural invasion and advanced stage. Multivariable analysis revealed that age, pleural invasion, lymph node metastasis and postoperative PGE-MUM levels were independent prognostic factors. In matched pre- and postoperative urine samples obtained from patients who are eligible for adjuvant chemotherapy, an increase in PGE-MUM levels following resection was an independent prognostic factor (hazard ratio 3.017, P = 0.005). Adjuvant chemotherapy improved survival in patients with increased PGE-MUM levels after resection (5-year overall survival, 79.0 vs 50.4%, P = 0.027), whereas survival benefit was not observed in those with decreased PGE-MUM levels (5-year overall survival, 82.1 vs 82.3%, P = 0.442).

CONCLUSIONS

Increased preoperative PGE-MUM levels can reflect tumour progression and postoperative PGE-MUM levels are a promising biomarker for survival after complete resection in patients with NSCLC. Perioperative changes in PGE-MUM levels may aid in determining the optimal eligibility for adjuvant chemotherapy.

Targeting cancer-related inflammation with non-steroidal anti-inflammatory drugs: Perspectives in pharmacogenomics

Inflammatory processes are essential for innate immunity and contribute to carcinogenesis in various malignancies, such as colorectal cancer, esophageal cancer and lung cancer. Pharmacotherapies targeting inflammation have the potential to reduce the risk of carcinogenesis and improve therapeutic efficacy of existing anti-cancer treatment. Non-steroidal anti-inflammatory drugs (NSAIDs), comprising a variety of structurally different chemicals that can inhibit cyclooxygenase (COX) enzymes and other COX-independent pathways, are originally used to treat inflammatory diseases, but their preventive and therapeutic potential for cancers have also attracted researchers' attention. Pharmacogenomic variability, including distinct genetic characteristics among different patients, can significantly affect pharmacokinetics and effectiveness of NSAIDs, which might determine the preventive or therapeutic success for cancer patients. Hence, a more comprehensive understanding in pharmacogenomic characteristics of NSAIDs and cancer-related inflammation would provide new insights into this appealing strategy. In this review, the up-to-date advances in clinical and experimental researches targeting cancer-related inflammation with NSAIDs are presented, and the potential of pharmacogenomics are discussed as well.

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.

Development of PET Radioligands Targeting COX-2 for Colorectal Cancer Staging, a Review of in vitro and Preclinical Imaging Studies

Colorectal cancer (CRC) is the second most common cause of cancer death, making early diagnosis a major public health challenge. The role of inflammation in tumorigenesis has been extensively explored, and among the identified markers of inflammation, cyclooxygenase-2 (COX-2) expression seems to be linked to lesions with a poor prognosis. Until now, COX-2 expression could only be accessed by invasive methods, mainly by biopsy. Imaging techniques such as functional Positron Emission Tomography (PET) could give access to in vivo COX-2 expression. This could make the staging of the disease more accurate and would be of particular interest in the exploration of the first metastatic stages. In this paper, we review recent progress in the development of COX-2 specific PET tracers by comparing the radioligands' characteristics and highlighting the obstacles that remain to be overcome in order to achieve the clinical development of such a radiotracer, and its evaluation in the management of CRC.

Fluorescent Probe for Monitoring Hydrogen Peroxide in COX-2-Positive Cancer Cells

Hydrogen peroxide (H₂O₂), an important marker for oxidative stress, plays a vital role in cellular biological functions. Overproduction of H₂O₂ causes oxidative damage to cellular functions and promotes cancer and other neurodegenerative diseases. Also, cyclooxygenase-2 (COX-2) enzyme is known to be expressed in several cancer types and exerts multifaceted roles in carcinogenesis and resistance to cancer treatment. Hence, it is important to monitor the H₂O₂ concentration changes in the COX-2-expressing cancer cells. Herein, we have developed a molecular fluorescent ratiometric H₂O₂-responsive probe (NPDIN) composed of indomethacin (COX-2 inhibitor) conjugated with 1,8-napthalimide boronate ester as fluorescent reporter through a chemical linker. The probe was capable of imaging the endogenous H₂O₂ in COX-2 overexpressing cancer cell lines (A549, LoVo, HT29, and Caco-2). Further studies revealed the critical role of the indomethacin moiety in the cellular uptake behavior of NPDIN in COX-2-overexpressing cancer cells. Collectively, our results demonstrated NPDIN as a COX-2-positive cancer-targeting sensitive ratiometric fluorescent probe (I₅₅₄/I₃₉₈) for H₂O₂ imaging and showed its promising biological applications in the future.

Emerging role of cysteinyl LTs in cancer

Cysteinyl leukotrienes (CysLTs) are inflammatory lipid mediators that play a central role in the pathophysiology of several inflammatory diseases. Recently, there has been an increased interest in determining how these lipid mediators orchestrate tumour development and metastasis through promoting a pro-tumour micro-environment. Up-regulation of CysLTs receptors and CysLTs production is found in a number of cancers and has been associated with increased tumorigenesis. Understanding the molecular mechanisms underlying the role of CysLTs and their receptors in cancer progression will help investigate the potential of targeting CysLTs signalling for anti-cancer therapy. This review gives an overview of the biological effects of CysLTs and their receptors, along with current knowledge of their regulation and expression. It also provides a recent update on the molecular mechanisms that have been postulated to explain their role in tumorigenesis and on the potential of anti-CysLTs in the treatment of cancer.

Clinical benefit of COX-2 inhibitors in the adjuvant chemotherapy of advanced non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Lung cancer is a major cause of death among patients, and non-small cell lung cancer (NSCLC) accounts for more than 80% of all lung cancers in many countries.

AIM

To evaluate the clinical benefit (CB) of COX-2 inhibitors in patients with advanced NSCLC using systematic review.

METHODS

We searched the six electronic databases up until December 9, 2019 for studies that examined the efficacy and safety of the addition of COX-2 inhibitors to chemotherapy for NSCLC. Overall survival (OS), progression free survival (PFS), 1-year survival rate (SR), overall response rate (ORR), CB, complete response (CR), partial response (PR), stable disease (SD), and toxicities were measured with more than one outcome as their endpoints. Fixed and random effects models were used to calculate risk estimates in a meta-analysis. Potential publication bias was calculated using Egger’s linear regression test. Data analysis was performed using R software.

RESULTS

The COX-2 inhibitors combined with chemotherapy were not found to be more effective than chemotherapy alone in OS, progression free survival, 1-year SR, CB, CR, and SD. However, there was a difference in overall response rate for patients with advanced NSCLC. In a subgroup analysis, significantly increased ORR results were found for celecoxib, rofecoxib, first-line treatment, and PR. For adverse events, the increase in COX-2 inhibitor was positively correlated with the increase in grade 3 and 4 toxicity of leukopenia, thrombocytopenia, and cardiovascular events.

CONCLUSION

COX-2 inhibitor combined with chemotherapy increased the total effective rate of advanced NSCLC with the possible increased risk of blood toxicity and cardiovascular events and had no effect on survival index.

Eicosanoids in Cancer: New Roles in Immunoregulation

Eicosanoids represent a family of active biolipids derived from arachidonic acid primarily through the action of cytosolic phospholipase A2-α. Three major downstream pathways have been defined: the cyclooxygenase (COX) pathway which produces prostaglandins and thromboxanes; the 5-lipoxygenase pathway (5-LO), which produces leukotrienes, lipoxins and hydroxyeicosatetraenoic acids, and the cytochrome P450 pathway which produces epoxygenated fatty acids. In general, these lipid mediators are released and act in an autocrine or paracrine fashion through binding to cell surface receptors. The pattern of eicosanoid production is cell specific, and is determined by cell-specific expression of downstream synthases. Increased eicosanoid production is associated with inflammation and a panel of specific inhibitors have been developed designated non-steroidal anti-inflammatory drugs. In cancer, eicosanoids are produced both by tumor cells as well as cells of the tumor microenvironment. Earlier studies demonstrated that prostaglandin E2, produced through the action of COX-2, promoted cancer cell proliferation and metastasis in multiple cancers. This resulted in the development of COX-2 inhibitors as potential therapeutic agents. However, cardiac toxicities associated with these agents limited their use as therapeutic agents. The advent of immunotherapy, especially the use of immune checkpoint inhibitors has revolutionized cancer treatment in multiple malignancies. However, the majority of patients do not respond to these agents as monotherapy, leading to intense investigation of other pathways mediating immunosuppression in order to develop rational combination therapies. Recent data have indicated that PGE2 has immunosuppressive activity, leading to renewed interest in targeting this pathway. However, little is known regarding the role of other eicosanoids in modulating the tumor microenvironment, and regulating anti-tumor immunity. This article reviews the role of eicosanoids in cancer, with a focus on their role in modulating the tumor microenvironment. While the role of PGE2 will be discussed, data implicating other eicosanoids, especially products produced through the lipoxygenase and cytochrome P450 pathway will be examined. The existence of small molecular inhibitors and activators of eicosanoid pathways such as specific receptor blockers make them attractive candidates for therapeutic trials, especially in combination with novel immunotherapies such as immune checkpoint inhibitors.

Notch in Head and Neck Cancer

Head and neck cancer is a group of neoplastic diseases affecting the facial, oral, and neck region. It is one of the most common cancers worldwide with an aggressive, invasive evolution. Due to the heterogeneity of the tissues affected, it is particularly challenging to study the molecular mechanisms at the basis of these tumors, and to date we are still lacking accurate targets for prevention and therapy. The Notch signaling is involved in a variety of tumorigenic mechanisms, such as regulation of the tumor microenvironment, aberrant intercellular communication, and altered metabolism. Here, we provide an up-to-date review of the role of Notch in head and neck cancer and draw parallels with other types of solid tumors where the Notch pathway plays a crucial role in emergence, maintenance, and progression of the disease. We therefore give a perspective view on the importance of the pathway in neoplastic development in order to define future lines of research and novel therapeutic approaches.

Effect of cyclo-oxygenase inhibitor use during checkpoint blockade immunotherapy in patients with metastatic melanoma and non-small cell lung cancer

Background

Immune checkpoint inhibitors (ICIs) improve survival outcomes in metastatic melanoma and non-small cell lung cancer (NSCLC). Preclinical evidence suggests that overexpression of cyclo-oxygenase-2 (COX2) in tumors facilitates immune evasion through prostaglandin E2 production and that COX inhibition synergizes with ICIs to promote antitumor T-cell activation. This study investigates whether concurrent COX inhibitor (COXi) use during ICI treatment compared with ICI alone is associated with improved time-to-progression (TTP), objective response rate (ORR) and overall survival (OS) in patients with metastatic melanoma and NSCLC.

Methods

We retrospectively reviewed 90 metastatic melanoma and 37 metastatic NSCLC patients, treated with ICI between 2011 and 2019. Differences in TTP and OS by ICI+COXi versus ICI alone were compared using Kaplan-Meier and Cox regression. Interaction between ICI+COXi versus ICI alone and pretreatment neutrophil–lymphocyte ratio (NLR) was examined. Independent radiology review per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 was performed.

Results

For patients with melanoma, median TTP was significantly prolonged in ICI+COXi versus ICI alone (245 vs 100.5 days, p=0.002). On multivariate analysis, ICI+COXi associated with increased TTP (HR 0.36, 95% CI 0.2 to 0.66, p=0.001), adjusted for age, pretreatment NLR, and gender. For NSCLC patients, ICI+COXi also associated with increased TTP compared with ICI alone on multivariate analysis (HR 0.45; 95% CI 0.21 to 0.97; p=0.042) adjusted for age. ORR at 6 months was significantly higher in patients who received ICI+COXi compared with ICI alone in both melanoma (58.6% vs 19.2%, p=0.0005) and NSCLC (73.7% vs 33.3%, p=0.036) cohorts. In the melanoma cohort, high pretreatment NLR (>5) associated with decreased TTP (HR 3.21, 95% CI 1.64 to 6.3; p=0.0007); however, ICI+COXi significantly associated with increased TTP in high NLR (>5) patients (HR 0.08, 95% CI 0.03 to 0.25), but not in low NLR (≤5) patients (HR 0.65, 95% CI 0.32 to 1.32). Similar outcomes were found in an adjusted melanoma cohort after RECIST review.

Conclusions

Our study suggests that COXi use concurrently with ICI significantly associated with longer TTP and improved ORR at 6 months in patients with metastatic melanoma and NSCLC compared with ICI alone. Furthermore, COXi use appears to reverse the negative prognostic effect of a high NLR by prolonging TTP in patients with melanoma.

The interaction between ferroptosis and lipid metabolism in cancer

Ferroptosis is a new form of programmed cell death characterized by the accumulation of iron-dependent lethal lipid peroxides. Recent discoveries have focused on alterations that occur in lipid metabolism during ferroptosis and have provided intriguing insights into the interplay between ferroptosis and lipid metabolism in cancer. Their interaction regulates the initiation, development, metastasis, therapy resistance of cancer, as well as the tumor immunity, which offers several potential strategies for cancer treatment. This review is a brief overview of the features characterizing the interaction between ferroptosis and lipid metabolism, and highlights the significance of this interaction in cancer.

Significance of Cyclooxygenase-2 in Oncogenesis

The cyclooxygenase-2 (COX-2) enzyme catalyses the first stage of biosynthesis of prostanoids, proteins that are implicated in various physiological and pathological processes in humans and animals. The expression of COX-2 increases significantly during pathological processes accompanied by inflammation, pain and fever. Overexpression of COX-2 was determined in tumour tissues, which suggests that this enzyme participates in oncogenesis. In this paper the topics discussed are mechanisms regulating COX-2 expression, COX isoforms, their role in the body and the oncogenic mechanisms triggered by the overexpression of COX-2, including inhibition of apoptosis, intensification of neoangiogenesis, increased metastatic capacity, and weakening of the immune system. The significance of and the mechanisms by which COX-2 participates in oncogenesis have been studied intensively in recent years. The results are highly promising, and they expand our understanding of the complex processes and changes at the molecular, cellular and tissue level that promote oncogenesis and cancer progression. Notwithstanding the knowledge already gleaned, many processes and mechanisms have not yet been elucidated in human medicine and, in particular, in veterinary medicine. Further research is required to develop effective tumour diagnostic methods and treatment procedures for humans and animals.

mPGES-1 and ALOX5/-15 in tumor-associated macrophages

The tumor immune landscape gained considerable interest based on the knowledge that genetic aberrations in cancer cells alone are insufficient for tumor development. Macrophages are basically supporting all hallmarks of cancer and owing to their tremendous plasticity they may exert a whole spectrum of anti-tumor and pro-tumor activities. As part of the innate immune response, macrophages are armed to attack tumor cells, alone or in concert with distinct T cell subsets. However, in the tumor microenvironment, they sense nutrient and oxygen gradients, receive multiple signals, and respond to this incoming information with a phenotype shift. Often, their functional output repertoire is shifted to become tumor-supportive. Incoming and outgoing signals are chemically heterogeneous but also comprise lipid mediators. Here, we review the current understanding whereby arachidonate metabolites derived from the cyclooxygenase and lipoxygenase pathways shape the macrophage phenotype in a tumor setting. We discuss these findings in the context of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) expression and concomitant prostaglandin E₂ (PGE₂) formation. We elaborate the multiple actions of this lipid in affecting macrophage biology, which are sensors for and generators of this lipid. Moreover, we summarize properties of 5-lipoxygenases (ALOX5) and 15-lipoxygenases (ALOX15, ALOX15B) in macrophages and clarify how these enzymes add to the role of macrophages in a dynamically changing tumor environment. This review will illustrate the potential routes how COX-2/mPGES-1 and ALOX5/-15 in macrophages contribute to the development and progression of a tumor.

Celecoxib With Neoadjuvant Chemotherapy for Breast Cancer Might Worsen Outcomes Differentially by COX-2 Expression and ER Status: Exploratory Analysis of the REMAGUS02 Trial

PURPOSE

The overexpression of cyclooxygenase 2 (COX-2) gene, also known as prostaglandin-endoperoxide synthase 2 ( PTGS2), occurs in breast cancer, but whether it affects response to anticox drugs remains unclear. We investigated the relationships between PTGS2 expression, celecoxib use during neoadjuvant chemotherapy (NAC), and both event-free survival (EFS) and overall survival (OS).

MATERIALS AND METHODS

We analyzed a cohort of 156 patients with human epidermal growth factor receptor 2 -negative breast cancer from the REMAGUS02 (ISRCTN Registry No. 10059974) trial with pretreatment PTGS2 expression data. Patients were treated by sequential NAC (epirubicin plus cyclophosphamide followed by docetaxel with or without celecoxib). Experimental validation was performed on breast cancer cell lines. The Cancer and Leukemia Group B (CALGB) 30801 ( ClinicalTrials.gov identifier: NCT01041781) trial that tested chemotherapy with or without celecoxib in patients with lung cancer served as an independent validation cohort.

RESULTS

After 94.5 months of follow-up, EFS was significantly lower in the celecoxib group (hazard ratio [HR], 1.7; 95% CI, 1 to 2.88; P = .046). A significant interaction between PTGS2 expression and celecoxib use was detected ( P_interaction = .01). In the PTGS2-low group (n = 100), EFS was lower in the celecoxib arm (HR, 3.01; 95% CI, 1.45 to 6.24; P = .002) than in the standard treatment arm. Celecoxib use was an independent predictor of poor EFS, distant relapse-free survival, and OS. Celecoxib in addition to docetaxel enhanced cell viability in PTGS2-low cell lines but not in PTGS2-high cell lines. In CALGB 30801, a trend toward poorer progression-free survival was observed in the patients with low urinary metabolite of prostaglandin E2 who received celecoxib (HR = 1.57; 95% CI, 0.87 to 2.84; P = .13).

CONCLUSION

Celecoxib use during chemotherapy adversely affected survival in patients with breast cancer, and the effect was more marked in PTGS2-low and/or estrogen receptor-negative tumors. COX-2 inhibitors should preferably be avoided during docetaxel use in patients with breast cancer who are undergoing NAC.

Macrophages in the microenvironment of head and neck cancer: potential targets for cancer therapy

The microenvironment of solid tumors has become a promising target for future therapies modulating immune cells. Patients with advanced head and neck cancer, which still portends a poor outcome, are particularly in need of innovative approaches. In oral squamous cell carcinoma, high density of tumor-associated macrophages (TAMs) appears consistently associated with poor prognosis, whereas data are currently limited for other head and neck sites. Several approaches to block TAMs have been investigated, including TAMs inactivation by means of the colony stimulating factor 1 (CSF-1)/CSF-1 receptor (CSF-1R) inhibitors or strategies to reprogram TAMs from M2 protumoral phenotype toward M1 antitumoral phenotype. This review focuses on both prognostic and therapeutic aspects related to TAMs in head and neck carcinomas.

Prostacyclin and EMT Pathway Markers for Monitoring Response to Lung Cancer Chemoprevention

Lung cancer is the leading cause of cancer death worldwide and global burden could be reduced through targeted application of chemoprevention. The development of squamous lung carcinoma has been linked with persistent, high-grade bronchial dysplasia. Bronchial histology improved in former smokers in a chemoprevention trial with the prostacyclin analogue iloprost. Prostacyclin acts through peroxisome proliferator-activated receptor gamma (PPARγ) to reverse epithelial to mesenchymal transition and promote anticancer signaling. We hypothesized that the prostacyclin signaling pathway and EMT could provide response markers for prostacyclin chemoprevention of lung cancer. Human bronchial epithelial cells were treated with cigarette smoke condensate (CSC) or iloprost for 2 weeks, CSC for 16 weeks, or CSC for 4 weeks followed by 4 weeks of CSC and/or iloprost, and RNA was extracted. Wild-type or prostacyclin synthase transgenic mice were exposed to 1 week of cigarette smoke or one injection of urethane, and RNA was extracted from the lungs. We measured potential markers of prostacyclin and iloprost efficacy in these models. We identified a panel of markers altered by tobacco carcinogens and inversely affected by prostacyclin, including PPARγ, 15PGDH, CES1, COX-2, ECADHERIN, SNAIL, VIMENTIN, CRB3, MIR34c, and MIR221 These data introduce a panel of potential markers for monitoring interception of bronchial dysplasia progression during chemoprevention with prostacyclin. Chemoprevention is a promising approach to reduce lung cancer mortality in a high-risk population. Identifying markers for targeted use is critical for success in future clinical trials of prostacyclin for lung cancer chemoprevention. Cancer Prev Res; 11(10); 643-54. ©2018 AACR.

Raging the War Against Inflammation With Natural Products

Over the last few decade Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the drugs of choice for treating numerous inflammatory diseases including rheumatoid arthritis. The NSAIDs produces anti-inflammatory activity via inhibiting cyclooxygenase enzyme, responsible for the conversation of arachidonic acid to prostaglandins. Likewise, cyclooxegenase-2 inhibitors (COX-2) selectively inhibit the COX-2 enzyme and produces significant anti-inflammatory, analgesic, and anti-pyretic activity without producing COX-1 associated gastrointestinal and renal side effects. In last two decades numerous selective COX-2 inhibitors (COXIBs) have been developed and approved for various inflammatory conditions. However, data from clinical trials have suggested that the prolong use of COX-2 inhibitors are also associated with life threatening cardiovascular side effects including ischemic heart failure and myocardial infection. In these scenario secondary metabolites from natural product offers a great hope for the development of novel anti-inflammatory compounds. Although majority of the natural product based compounds exhibit more selectively toward COX-1. However, the data suggest that slight structural modification can be helpful in developing COX-2 selective secondary metabolites with comparative efficacy and limited side effects. This review is an effort to highlight the secondary metabolites from terrestrial and marine source with significant COX-2 and COX-2 mediated PGE2 inhibitory activity, since it is anticipated that isolates with ability to inhibit COX-2 mediated PGE2 production would be useful in suppressing the inflammation and its classical sign and symptoms. Moreover, this review has highlighted the potential lead compounds including berberine, kaurenoic acid, α-cyperone, curcumin, and zedoarondiol for further development with the help of structure-activity relationship (SAR) studies and their current status.

Systematic review and meta-analysis of the benefit of celecoxib in treating advanced non-small-cell lung cancer

Background

The clinical benefit of a selective cyclooxygenase-2 inhibitor, celecoxib, combined with anticancer therapy in advanced non-small-cell lung cancer (NSCLC) remains unclear. A meta-analysis was performed to address the efficacy and safety of celecoxib in patients with advanced NSCLC.

Materials and methods

Three databases, including PubMed, EMBASE, and the Cochrane Library, were systematically searched for available literature until March 1, 2018. Data on tumor response rates, one-year survival, overall survival, progression-free survival, and toxicities were extracted from the included randomized clinical trials. Subgroup analysis was carried out according to the line of treatment. Review Manager 5.3 software was applied to conduct the meta-analysis.

Results

A total of 7 randomized controlled trials involving 1,559 patients with advanced NSCLC were enrolled for analysis. The pooled overall response rate (ORR) of celecoxib added to systemic therapy was not significantly improved (risk ratio [RR] =1.14, 95% CI =0.96–1.35, P=0.13). Additionally, no differences were observed between the celecoxib and placebo groups regarding 1-year survival (RR =0.99, 95% CI =0.88–1.12, P=0.91). Subgroup analysis showed that adding celecoxib to the first-line treatment significantly improved the ORR (RR =1.21, 95% CI =1.01–1.44, P=0.04) and partial response rate (RR =1.26, 95% CI =1.01–1.58, P=0.04). The aggregated Kaplan–Meier analysis found no significant difference between celecoxib and placebo regarding the 5-year overall survival (median, 12.9 vs 12.5 months, P=0.553) and 5-year progression-free survival (median, 7.4 vs 7.2 months, P=0.641). The increased RR of leukopenia (RR =1.25, 95% CI =1.03–1.50) and thrombocytopenia (RR =1.39, 95% CI =1.11–1.75) indicated that celecoxib increased hematologic toxicities (grade ≥III). However, celecoxib did not increase the related risks of thrombosis or embolism (RR =1.26, 95% CI =0.66–2.39) and cardiac ischemia (RR =1.16, 95% CI =0.39–3.44).

Conclusion

Celecoxib had no benefit on survival indices for advanced NSCLC but improved the ORR of first-line treatment. Additionally, celecoxib increased the rate of hematologic toxicities without increasing the risk of cardiovascular events.

Do older patients with non-small cell lung cancer also benefit from first-line platinum-based doublet chemotherapy? Observations from a pooled analysis of 730 prospectively-treated patients (Alliance Study A151622)

OBJECTIVE

This study sought to define the role of first-line platinum-based doublet chemotherapy in older patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We analyzed three first-line NSCLC trials: CALGB 9730, CALGB 30203, and CALGB 30801, which tested carboplatin and paclitaxel; carboplatin and gemcitabine; and carboplatin with either pemetrexed or gemcitabine, respectively. Overall survival was the primary endpoint. Age-based comparisons with a cutpoint of 65 years were performed with Cox proportional hazards models with adjustments for sex, tumor histology, cancer stage, chemotherapy, and smoking history and after stratifying by performance score. Secondary endpoints were grade 3-5 adverse events, chemotherapy cycles completed, and whether toxicity prompted chemotherapy discontinuation.

RESULTS

730 patients were included; 337 (46%) were 65+ years of age. No statistically significant difference in survival was observed for older (≥65) versus younger patients (HR = 1.096; 95% CI = (0.94, 1.28); p = 0.25). A trend emerged with increased odds of a grade 3-5 adverse event for patients ≥65 years versus <65 years (OR = 1.52; 95% CI = (0.99, 2.31); p = 0.05). The proportion of completed chemotherapy cycles was marginally lower in older patients (difference = -5%; 95% CI = (-9, 0.2); p = 0.06) for those ≥65 years versus <65 years, but no statistically significant difference occurred in the rate of chemotherapy discontinuation for toxicity (OR = 1.4; 95% CI = (0.85, 2.19); p = 0.21) for patients ≥65 years versus <65 years. A cutpoint of 70 years yielded similar results.

CONCLUSION

These findings support carboplatin doublet-based chemotherapy in select older patients with advanced NSCLC.

Time-to-Treatment-Failure and Related Outcomes Among 1000+ Advanced Non-Small Cell Lung Cancer Patients: Comparisons Between Older Versus Younger Patients (Alliance A151711)

INTRODUCTION

Time-to-treatment-failure (TTF) is the interval from chemotherapy initiation to premature discontinuation. We evaluated TTF based on age.

METHODS

Pooled analyses were conducted with first-line chemotherapy trials for advanced NSCLC (CALGB 9730, 30203, and 30801). Comparisons among patients who were 65 years and older and 70 years and older were performed for TTF (primary endpoint), reasons for early chemotherapy cessation, grade 3+ adverse events, and overall survival.

RESULTS

Among 1006 patients, 460 (46%) were older than 65 years of age. One hundred forty-five older patients (32% of this age cohort) completed all six planned chemotherapy cycles as did 170 (32%) younger patients. Median TTF was 2.9 months (95% confidence interval: 2.7- 3.2) in older patients and 3 months (95% confidence interval: 2.9-3.5) in younger patients; adjustment for performance status and stratification by chemotherapy by trial yielded no statistically significant age-based difference in TTF. However, reasons for early chemotherapy cessation differed between age groups (multivariate p = 0.004). Older patients were less likely to discontinue from cancer progression (41% versus 55%) and more likely from toxicity or patient choice (16% and 15%, respectively) compared to younger patients (13% and 6%, respectively). Older patients were more likely to experience grade 3+ adverse events (86% versus 79%) with no statistically significant difference in survival. An age cutpoint of 70+ years showed no difference in TTF, a lower trend of early cessation due to cancer progression, and somewhat shorter older patient survival.

CONCLUSIONS

TTF was comparable between older and younger patients; but different, age-based, and potentially modifiable reasons account for it.

Celecoxib and sulindac inhibit TGF-β1-induced epithelial-mesenchymal transition and suppress lung cancer migration and invasion via downregulation of sirtuin 1

The non-steroidal anti-inflammatory drugs (NSAIDs) celecoxib and sulindac have been reported to suppress lung cancer migration and invasion. The class III deacetylase sirtuin 1 (SIRT1) possesses both pro- and anticarcinogenic properties. However, its role in inhibition of lung cancer cell epithelial-mesenchymal transition (EMT) by NSAIDs is not clearly known. We attempted to investigate the potential use of NSAIDs as inhibitors of TGF-β1-induced EMT in A549 cells, and the underlying mechanisms of suppression of lung cancer migration and invasion by celecoxib and sulindac. We demonstrated that celecoxib and sulindac were effective in preventing TGF-β1-induced EMT, as indicated by upregulation of the epithelial marker, E-cadherin, and downregulation of mesenchymal markers and transcription factors. Moreover, celecoxib and sulindac could inhibit TGF-β1-enhanced migration and invasion of A549 cells. SIRT1 downregulation enhanced the reversal of TGF-β1-induced EMT by celecoxib or sulindac. In contrast, SIRT1 upregulation promoted TGF-β1-induced EMT. Taken together, these results indicate that celecoxib and sulindac can inhibit TGF-β1-induced EMT and suppress lung cancer cell migration and invasion via downregulation of SIRT1. Our findings implicate overexpressed SIRT1 as a potential therapeutic target to reverse TGF-β1-induced EMT and to prevent lung cancer cell migration and invasion.

COX-2 expression and effects of celecoxib in addition to standard chemotherapy in advanced non-small cell lung cancer

AIM

Inhibition of cyclooxygenase-2 (COX-2) is proposed as a treatment option in several cancer types. However, in non-small cell lung cancer (NSCLC), phase III trials have failed to demonstrate a benefit of adding COX-2 inhibitors to standard chemotherapy. The aim of this study was to analyze COX-2 expression in tumor and stromal cells as predictive biomarker for COX-2 inhibition.

METHODS

In a multicenter phase III trial, 316 patients with advanced NSCLC were randomized to receive celecoxib (400 mg b.i.d.) or placebo up to one year in addition to a two-drug platinum-based chemotherapy combination. In a subset of 122 patients, archived tumor tissue was available for immunohistochemical analysis of COX-2 expression in tumor and stromal cells. For each compartment, COX-2 expression was graded as high or low, based on a product score of extension and intensity of positively stained cells.

RESULTS

An updated analysis of all 316 patients included in the original trial, and of the 122 patients with available tumor tissue, showed no survival differences between the celecoxib and placebo arms (HR 1.01; 95% CI 0.81-1.27 and HR 1.12; 95% CI 0.78-1.61, respectively). High COX-2 scores in tumor (n = 71) or stromal cells (n = 55) was not associated with a superior survival outcome with celecoxib vs. placebo (HR =0.96, 95% CI 0.60-1.54; and HR =1.51; 95% CI 0.86-2.66), and no significant interaction effect between COX-2 score in tumor or stromal cells and celecoxib effect on survival was detected (p = .48 and .25, respectively).

CONCLUSIONS

In this subgroup analysis of patients with advanced NSCLC treated within the context of a randomized trial, we could not detect any interaction effect of COX-2 expression in tumor or stromal cells and the outcome of celecoxib treatment in addition to standard chemotherapy.

Prognostic value of Cox-2 and PD-L1 expression and its relationship with tumor-infiltrating lymphocytes in resected lung adenocarcinoma

Programmed cell death-1 ligand 1 (PD-L1), tumor-infiltrating CD8-positive T lymphocytes (CD8-positive TILs), and cyclooxygenase-2 (Cox-2) have been used as prognostic tools in patients with lung adenocarcinoma. We conducted a retrospective review of data from 170 patients who had undergone pulmonary resection as an initial treatment for clinical T1-2 N0 lung adenocarcinoma. We then investigated the expressions of three biomarkers using immunohistochemical analyses and compared the expression levels with the clinicopathological characteristics and outcomes of the patients. Next, we classified the tumors into four groups based on the PD-L1 and CD8-positive TILs statuses and evaluated the prognostic significance of Cox-2 expression according to the tumor immune microenvironment classification. Tumors with positive PD-L1 expression levels had a significantly larger number of CD8-positive TILs than tumors with negative PD-L1 expression levels, whereas tumors with high Cox-2 expressions had significantly fewer CD8-positive TILs than tumors with low Cox-2 expressions. A multivariate analysis showed that histological subtype, nodal metastasis, CD8-positive TILs count, and PD-L1 expression were independent predictors of patient outcome. Using a classification based on the PD-L1 and CD8-positive TILs statuses, the outcomes of patients with a negative PD-L1 expression and a high CD8-positive TIL count were significantly better than those with other classifications. In patients with negative PD-L1 and low CD8-positive TILs, the rate of EGFR mutation was significantly higher than that in other classifications, and Cox-2 expression was a powerful predictor of outcome. Clinical and pathological features in conjunction with the tumor immune microenvironment classification indicate that lung adenocarcinoma should be divided into different subgroups for prognosis and treatment. Classification according to the PD-L1 and CD8-positive TILs statuses might enable the effects of Cox-2 inhibitor to be predicted.

Potential clinical value of PET/CT in predicting occult nodal metastasis in T1-T2N0M0 lung cancer patients staged by PET/CT

We assessed the clinical value of 2-fluoro-2-deoxyglucose (¹⁸F-FDG) PET/CT imaging for predicting occult nodal metastasis in non-small cell lung cancer (NSCLC) patients. This retrospective study included 54 patients with T1-2N0M0 NSCLC who had undergone ¹⁸F-FDG PET/CT before surgery. Occult nodal metastasis was detected in 25.9% (14/54) of the patients. Immunohistochemical analysis revealed that increased glucose transporter 1 expression was associated with occult nodal metastasis, but hexokinase 2 expression was not. Compared to the negative nodal metastasis group, the positive nodal metastasis group was associated with increased maximum standardized uptake value (SUVmax) and tumor size. Multivariate analysis indicated that SUVmax and tumor size were associated with nodal metastasis. Nodal metastasis could be predicted with a sensitivity of 92.9% and a specificity of 55.0% when the SUVmax cutoff was 4.35. When patients were divided into low-risk (tumor size ≤ 2.5 cm and SUVmax ≤ 4.35), moderate-risk (tumor size ≤ 2.5 cm and SUVmax > 4.35 or tumor size > 2.5 cm and SUVmax ≤ 4.35) and high-risk (tumor size > 2.5 cm and SUVmax > 4.35) groups, the lymph node metastasis rates were 4.3%, 22.7%, and 88.9%, respectively. These results indicate that the combination of SUVmax and tumor size has potential clinical value for predicting occult nodal metastasis in NSCLC patients.

The prognostic value of cyclooxygenase-2 expression in patients with esophageal cancer: evidence from a meta-analysis

Published studies have investigated the prognostic role of cyclooxygenase-2 (COX-2) expression in patients with esophageal cancer (EC), but the result remains controversial. Thus, this meta-analysis was conducted to comprehensively evaluate the impact of COX-2 expression on the prognostic value in patients with EC. Relevant studies were identified from PubMed, EMBASE, and Web of Science databases. Studies that detected the COX-2 expression by immunohistochemistry and evaluated the relationship between COX-2 expression and overall survival (OS) or clinicopathological parameters were used in our analysis. The summary hazard ratios (HRs) or odds ratios were calculated to assess the risk or hazard association. A total of 25 studies, which included 2,465 patients, were included in our meta-analysis. Our analysis suggested that overexpression of COX-2 was associated with poor OS (HR =1.60, 95% CI =1.32–1.94, P<0.001). Subgroup analyses by race, percentage of high/positive COX-2 expression, histology type, treatment, and sample size all suggested significant association. Moreover, overexpression of COX-2 was significantly associated with depth of invasion, lymph node metastasis, distant metastasis, and TNM stage. This meta-analysis suggested that overexpression of COX-2 might serve as a prognostic biomarker for EC. Large well-designed prospective studies are needed to confirm our conclusion.

Urinary levels of prostaglandin E2 are positively correlated with intratumoral infiltration of Foxp3+ regulatory T cells in non-small cell lung cancer

The immune microenvironment of primary tumors has been reported to be one of the factors influencing the prognosis of patients with cancer. The tumor-infiltrating regulatory T cell (Treg) count has previously been revealed to be positively correlated with intratumoral cyclooxygenase-2 (Cox-2) expression, and was also associated with poor survival among patients with non-small cell lung cancer (NSCLC). In addition, the urinary levels of a prostaglandin E₂ (PGE₂) metabolite (PGE-M) were used as a biomarker in clinical trials of the Cox-2 inhibitor celecoxib. In the current prospective study, the association of urinary PGE₂ and PGE-M levels with intratumoral Cox-2 expression and Treg count was examined in patients with NSCLC. A total of 21 patients with NSCLC who underwent complete resection of the tumor at Kawasaki Medical School Hospital (Kurashiki, Japan) were enrolled. Urine specimens were obtained prior to surgery in order to examine urinary PGE₂ and PGE-M levels. A significant positive association was observed between urinary PGE₂ levels and the intratumoral Treg count (P=0.023), but not the intratumoral Cox-2 expression levels. No significant associations were identified between urinary PGE₂ levels and any of the other clinicopathological characteristics examined, including age, sex, smoking history, histology, tumor size, nodal status and disease stage. However, no significant association was observed between urinary PGE-M levels and the intratumoral Treg count (P=0.069) or Cox-2 expression. In conclusion, urinary PGE₂ levels were positively correlated with intratumoral Treg counts in patients with NSCLC in the current study. This indicates that urinary PGE₂ may be an improved biomarker, compared with PGE-M, for the prediction of intratumoral Treg numbers.

Phase III Randomized, Placebo-Controlled, Double-Blind Trial of Celecoxib in Addition to Standard Chemotherapy for Advanced Non-Small-Cell Lung Cancer With Cyclooxygenase-2 Overexpression: CALGB 30801 (Alliance)

Purpose Tumor overexpression of cyclooxygenase-2 (COX-2) has been associated with worse outcome in non-small-cell lung cancer (NSCLC). In Cancer and Leukemia Group B (CALGB) 30203, we found that the selective COX-2 inhibitor celecoxib in addition to chemotherapy in advanced NSCLC improved progression-free and overall survival in patients with moderate to high COX-2 expression by immunohistochemistry (IHC). CALGB 30801 (Alliance) was designed to prospectively confirm that finding. Patients and Methods Patients with NSCLC (stage IIIB with pleural effusion or stage IV according to American Joint Committee on Cancer [sixth edition] criteria) were preregistered, and biopsy specimens were analyzed for COX-2 by IHC. Patients with COX-2 expression ≥ 2, performance status of 0 to 2, and normal organ function were eligible. Chemotherapy was determined by histology: carboplatin plus pemetrexed for nonsquamous NSCLC and carboplatin plus gemcitabine for squamous histology. Patients were randomly assigned to celecoxib (400 mg twice per day; arm A) or placebo (arm B). The primary objective was to demonstrate improvement in progression-free survival in patients with COX-2 index ≥ 4 with hazard ratio of 0.645 with approximately 85% power at two-sided significance level of .05. Results The study was halted for futility after 312 of the planned 322 patients with COX-2 index ≥ 2 were randomly assigned. There were no significant differences between the groups (hazard ratio, 1.046 for COX-2 ≥ 4). Subset analyses evaluating histology, chemotherapy regimen, and incremental COX-2 expression did not demonstrate any advantage for COX-2 inhibition. Elevation of baseline urinary metabolite of prostaglandin E2, indicating activation of the COX-2 pathway, was a negative prognostic factor. Values above the third quartile may have been a predictive factor. Conclusion COX-2 expression by IHC failed to select patients who could benefit from selective COX-2 inhibition. Urinary metabolite of prostaglandin E2 may be able to identify patients who could benefit from COX-2 inhibition.

Mutant KRAS Enhances Tumor Cell Fitness by Upregulating Stress Granules

There is growing evidence that stress-coping mechanisms represent tumor cell vulnerabilities that may function as therapeutically beneficial targets. Recent work has delineated an integrated stress adaptation mechanism that is characterized by the formation of cytoplasmic mRNA and protein foci, termed stress granules (SGs). Here, we demonstrate that SGs are markedly elevated in mutant KRAS cells following exposure to stress-inducing stimuli. The upregulation of SGs by mutant KRAS is dependent on the production of the signaling lipid molecule 15-deoxy-delta 12,14 prostaglandin J2 (15-d-PGJ2) and confers cytoprotection against stress stimuli and chemotherapeutic agents. The secretion of 15-d-PGJ2 by mutant KRAS cells is sufficient to enhance SG formation and stress resistance in cancer cells that are wild-type for KRAS. Our findings identify a mutant KRAS-dependent cell non-autonomous mechanism that may afford the establishment of a stress-resistant niche that encompasses different tumor subclones. These results should inform the design of strategies to eradicate tumor cell communities.

Radiochemistry on electrodes: Synthesis of an 18F-labelled and in vivo stable COX-2 inhibitor

New radiochemistry techniques can yield novel PET tracers for COX-2 and address the shortcomings in in vivo stability and specificity, which have held back clinical translation of tracers to image COX-2 expression. Current techniques limit radiosynthesis to analogs of the COX-2 inhibitors with fluorine-18 added via a carbon chain, or on an aromatic position which renders the radiolabeled analog less specific towards COX-2, resulting in tracers with low in vivo stability or specificity. To solve this problem, we have developed a new high affinity, ¹⁸F-labelled COX-2 inhibitor that is radiolabeled directly on a heteroaromatic ring. This molecule exhibits favorable biodistribution and increased metabolic stability. Synthesis of this molecule cannot be achieved by traditional means; consequently, we have developed an automated electrochemical radiosynthesis platform to synthesize up to 5 mCi of radiochemically pure ¹⁸F-COX-2ib in 4 hours (2% decay-corrected radiochemical yield). In vitro studies demonstrated clear correlation between COX-2 expression and uptake of the tracer. PET imaging of healthy animals confirmed that the molecule is excreted from blood within an hour, mainly through the hepatobiliary excretion pathway. In vivo metabolism data demonstrated that > 95% of the injected radioactivity remains in the form of the parent molecule 1 hour after injection.

Cyclooxygenase-2 Induction by Amino Acid Deprivation Requires p38 Mitogen-Activated Protein Kinase in Human Glioma Cells

Glioblastomas (GBMs) are malignant brain tumors that can outstrip nutrient supplies due to rapid growth. Cyclooxygenase-2 (COX-2) has been linked to GBMs and may contribute to their aggressive phenotypes. Amino acid starvation results in COX-2 mRNA and protein induction in multiple human glioma cell lines in a process requiring p38 mitogen-activated protein kinase (p38-MAPK) and the Sp1 transcription factor. Increased vascular endothelial growth factor expression results from starvation-dependent COX-2 induction. These data suggest that COX-2 induction with amino acid deprivation may be a part of the adaptation of glioma cells to these conditions, and potentially alter cellular response to anti-neoplastic therapy.

Statistical aspect of translational and correlative studies in clinical trials

In this article, we describe statistical issues related to the conduct of translational and correlative studies in cancer clinical trials. In the era of personalized medicine, proper biomarker discovery and validation is crucial for producing groundbreaking research. In order to carry out the framework outlined in this article, a team effort between oncologists and statisticians is the key for success.

Clinicopathological and immunohistochemical features of lung invasive mucinous adenocarcinoma based on computed tomography findings

Background

We performed an analysis to clarify differences in clinicopathological and molecular features of lung invasive mucinous adenocarcinoma (IMA) based on computed tomography (CT) findings and their impact on prognosis.

Patients and methods

On the basis of CT findings, we divided lung IMA into three subtypes: solid, bubbling, and pneumonic. We then investigated differences in clinicopathological characteristics, prognosis, and the expressions of well-identified biomarkers, including cyclooxygenase-2 (Cox-2), excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M1 (RRM1), class III beta-tubulin, thymidylate synthase (TS), secreted protein acidic and rich in cysteine (SPARC), programmed cell death-1 ligand-1 (PD-L1), and epidermal growth factor receptor mutation, among the three subtypes.

Results

A total of 29 patients with resected lung IMA were analyzed. Compared with the solid or bubbling type, the pneumonic type had a higher proportion of symptoms, a larger tumor size, a higher pathological stage, and a significantly worse prognosis. The immunohistochemical findings tended to show high expression of RRM1, class III beta-tubulin, and Cox-2 in the tumor and of SPARC in the stroma, but not of ERCC1, TS, and PD-L1 in the tumor. None of the biomarkers with high expression levels in the tumor were prognostic biomarkers, but the expression of SPARC in the stroma was correlated with a poor outcome.

Conclusion

Clinical and pathological features, in conjunction with molecular data, indicate that IMA should be divided into different subgroups. In our results, the pneumonic type was correlated with a significantly worse outcome. Further studies should be performed to confirm our conclusion and to explore its molecular implications.

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.

Antitumor Activity of Cytotoxic Cyclooxygenase-2 Inhibitors

Targeted delivery of chemotherapeutic agents to tumors has been explored as a means to increase the selectivity and potency of cytotoxicity. Most efforts in this area have exploited the molecular recognition of proteins highly expressed on the surface of cancer cells followed by internalization. A related approach that has received less attention is the targeting of intracellular proteins by ligands conjugated to anticancer drugs. An attractive target for this approach is the enzyme cyclooxygenase-2 (COX-2), which is highly expressed in a range of malignant tumors. Herein, we describe the synthesis and evaluation of a series of chemotherapeutic agents targeted to COX-2 by conjugation to indomethacin. Detailed characterization of compound 12, a conjugate of indomethacin with podophyllotoxin, revealed highly potent and selective COX-2 inhibition in vitro and in intact cells. Kinetics and X-ray crystallographic studies demonstrated that compound 12 is a slow, tight-binding inhibitor that likely binds to COX-2's allosteric site with its indomethacin moiety in a conformation similar to that of indomethacin. Compound 12 exhibited cytotoxicity in cell culture similar to that of podophyllotoxin with no evidence of COX-2-dependent selectivity. However, in vivo, compound 12 accumulated selectively in and more effectively inhibited the growth of a COX-2-expressing xenograft compared to a xenograft that did not express COX-2. Compound 12, which we have named chemocoxib A, provides proof-of-concept for the in vivo targeting of chemotherapeutic agents to COX-2 but suggests that COX-2-dependent selectivity may not be evident in cell culture-based assays.

Regulatory T cells function at the early stage of tumor progression in a mouse model of tongue squamous cell carcinoma

The objective of this study was to observe the distribution of regulatory T cells (Tregs) in the development of tongue squamous cell carcinoma (SCC) and to determine the role of Tregs in the progression of tongue SCC. A mouse model of 4-nitroquinoline-1-oxide (4NQO)-induced-tongue SCC was established. The expression of Forkhead box P3 (Foxp3), interleukin 10, transforming growth factor-β, chemokine CC motif ligands 17, 20, and CC chemokine receptor 4 was determined using real-time quantitative polymerase chain reaction. Foxp3 expression was also analyzed using immunohistochemistry. The results were compared with those of control mice and of 4NQO-treated mice treated with a cyclooxygenase-2 (COX-2) inhibitor. Well to moderately differentiated tongue SCC was induced in all of the experimental mice. The amount of Tregs of the experimental mice was over 10 times as much as control mice at the early stage of tumor progression. COX-2 inhibitor did not prevent the progression of tongue SCC and did not reduce the total amount of Tregs. Tregs function at the early stage of the development of tongue SCC, and it may be effective to suppress Tregs at the early stage of tumor progression for the treatment and/or prevention of tongue SCC.

Molecular profiling of 6,892 colorectal cancer samples suggests different possible treatment options specific to metastatic sites

Metastatic colorectal cancer (mCRC) carries a poor prognosis with an overall 5-year survival of 13.1%. Therapies guided by tumor profiling have suggested benefit in advanced cancer. We used a multiplatform molecular profiling (MP) approach to identify key molecular changes that may provide therapeutic options not typically considered in mCRC. We evaluated 6892 mCRC referred to Caris Life Sciences by MP including sequencing (Sanger/NGS), immunohistochemistry (IHC) and in-situ hybridization (ISH). mCRC metastases to liver, brain, ovary or lung (n = 1507) showed differential expression of markers including high protein expression of TOPO1 (52%) and/or low RRM1 (57%), TS (71%) and MGMT (39%), suggesting possible benefit from irinotecan, gemcitabine, 5FU/capecitabine and temozolomide, respectively. Lung metastases harbored a higher Her2 protein expression than the primary colon tumors (4% vs. 1.8%, p = 0.028). Brain and lung metastases had higher KRAS mutations than other sites (65% vs 59% vs 47%, respectively, p = 0.07, <0.01), suggesting poor response to anti-EGFR therapies. BRAF-mutated CRC (n = 455) showed coincident high protein expression of RRM1 (56%), TS (53%) and low PDGFR (22%) as compared with BRAF wild-type tumors. KRAS-mutated mCRC had higher protein expression of c-MET (47% vs. 36%) and lower MGMT (56% vs. 63%), suggesting consideration of c-MET inhibitors and temozolomide. KRAS-mutated CRC had high TUBB3 (42% vs. 33%) and low Her2 by IHC (0.5%) and HER2 by FISH (3%, p <0.05). CRC primaries had a lower incidence of PIK3CA and BRAF mutations in rectal cancer versus colon cancer (10% and 3.3%, respectively). MP of 6892 CRCs identified significant differences between primary and metastatic sites and among BRAF/KRAS sub-types. Our findings are hypothesis generating and need to be examined in prospective studies. Specific therapies may be considered for different actionable targets in mCRC as revealed by MP.

Prostaglandin E Receptor EP4 expression, survival and pattern of recurrence in locally advanced NSCLC

BACKGROUND

Elevated COX-2 expression has been correlated with inferior outcome in NSCLC. COX-2 catalyzes the transformation of arachidonate to PGE₂. We and others have demonstrated that PGE₂ induces proliferation and metastatic spread and immunosuppression through the G protein-coupled EP4 receptor. We hypothesized that EP4 expression on malignant cells would correlate with outcome and patterns of relapse after treatment of LANSCLC stage IIIA (7th edition, N2+).

METHODS

Tissue specimens from 41 pts treated for LANSC at UMGCC were obtained. A tissue microarray was prepared and examined for EP4 expression. Intensity of staining was scored semi-quantitatively as 0-4 in both the nuclear and cytoplasmic compartments by a pathologist blinded to the clinical data.

RESULTS

EP4 nuclear staining 0-1 vs. 2+ was associated with overall survival, (OS) (44.3 vs. 18 mo; HR=0.41, p=0.024) and numerically superior progression free survival (PFS) (16.4 vs. 10.2 mo, p=0.16). EP4 cytoplasmic staining did not correlate with OS (0-1 vs. 2+, 23.8 vs. 28.8 mo; HR=1.2, p=0.81). Relapse pattern (no relapse or local vs. systemic) did not correlate with EP nuclear staining (p=1.0, X²).

CONCLUSIONS

This is the first clinical study of EP4 expression in lung cancer. There was a significant correlation between OS and nuclear EP4 expression, indicating that this is a potential therapeutic target. Studies with AT-007, a specific inhibitor of EP4, are planned to commence this year.

Macrophages, Inflammation, and Lung Cancer

Lung cancer is the leading cause of cancer mortality worldwide, and at only 18%, it has one of the lowest 5-year survival rates of all malignancies. With its highly complex mutational landscape, treatment strategies against lung cancer have proved largely ineffective. However with the recent success of immunotherapy trials in lung cancer, there is renewed enthusiasm in targeting the immune component of tumors. Macrophages make up the majority of the immune infiltrate in tumors and are a key cell type linking inflammation and cancer. Although the mechanisms through which inflammation promotes cancer are not fully understood, two connected hypotheses have emerged: an intrinsic pathway, driven by genetic alterations that lead to neoplasia and inflammation, and an extrinsic pathway, driven by inflammatory conditions that increase cancer risk. Here, we discuss the contribution of macrophages to these pathways and subsequently their roles in established tumors. We highlight studies investigating the association of macrophages with lung cancer prognosis and discuss emerging therapeutic strategies for targeting macrophages in the tumor microenvironment.

Time-dependent classification accuracy curve under marker-dependent sampling

Evaluating the classification accuracy of a candidate biomarker signaling the onset of disease or disease status is essential for medical decision making. A good biomarker would accurately identify the patients who are likely to progress or die at a particular time in the future or who are in urgent need for active treatments. To assess the performance of a candidate biomarker, the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) are commonly used. In many cases, the standard simple random sampling (SRS) design used for biomarker validation studies is costly and inefficient. In order to improve the efficiency and reduce the cost of biomarker validation, marker-dependent sampling (MDS) may be used. In a MDS design, the selection of patients to assess true survival time is dependent on the result of a biomarker assay. In this article, we introduce a nonparametric estimator for time-dependent AUC under a MDS design. The consistency and the asymptotic normality of the proposed estimator is established. Simulation shows the unbiasedness of the proposed estimator and a significant efficiency gain of the MDS design over the SRS design.

PGE2 induced in and released by dying cells functions as an inhibitory DAMP

Cellular components released into the external milieu as a result of cell death and sensed by the body are generally termed damage-associated molecular patterns (DAMPs). Although DAMPs are conventionally thought to be protective to the host by evoking inflammatory responses important for immunity and wound repair, there is the prevailing notion that dysregulated release of DAMPs can also underlie or exacerbate disease development. However, the critical issue for how resultant DAMP-mediated responses are regulated has heretofore not been fully addressed. In the present study, we identify prostaglandin E2 (PGE2) as a DAMP that negatively regulates immune responses. We show that the production of PGE2 is augmented under cell death-inducing conditions via the transcriptional induction of the cyclooxygenase 2 (COX2) gene and that cell-released PGE2 suppresses the expression of genes associated with inflammation, thereby limiting the cell's immunostimulatory activities. Consistent with this, inhibition of the PGE2 synthesis pathway potentiates the inflammation induced by dying cells. We also provide in vivo evidence for a protective role of PGE2 released upon acetaminophen-induced liver injury as well as a pathogenic role for PGE2 during tumor cell growth. Our study places this classically known lipid mediator in an unprecedented context-that is, an inhibitory DAMP vis-à-vis activating DAMPs, which may have translational implications for designing more effective therapeutic regimens for inflammation-associated diseases.

Clinical Profile of Cyclooxygenase-2 Inhibitors in Treating Non-Small Cell Lung Cancer: A Meta-Analysis of Nine Randomized Clinical Trials

Background

Evidence on the benefits of combining cyclooxygenase-2 inhibitor (COX-2) in treating non-small cell lung cancer (NSCLC) is still controversial. We investigated the efficacy and safety profile of cyclooxygenase-2 inhibitors in treating NSCLC.

Methods

The first meta-analysis of eligible studies was performed to assess the effect of COX-2 inhibitors for patients with NSCLC on the overall response rate (ORR), overall survival (OS), progression-free survival (PFS), one-year survival, and toxicities. The fixed-effects model was used to calculate the pooled RR and HR and between-study heterogeneity was assessed. Subgroup analyses were conducted according to the type of COX-2 inhibitors, treatment pattern, and treatment line.

Results

Nine randomized clinical trials, comprising 1679 patents with NSCLC, were included in the final meta-analysis. The pooled ORR of patients who have NSCLC with COX-2 inhibitors was significantly higher than that without COX-2 inhibitors. In subgroup analysis, significantly increased ORR results were found on celecoxib (RR = 1.29, 95% CI: 1.09, 1.51), rofecoxib (RR = 1.61, 95% CI: 1.14, 2.28), chemotherapy (RR = 1.40, 95% CI: 1.20, 1.63), and first-line treatment (RR = 1.39, 95% CI: 1.19, 1.63). However, COX-2 inhibitors had no effect on the one-year survival, OS, and PFS. Increased RR of leucopenia (RR = 1.21, 95% CI: 1.01, 1.45) and thrombocytopenia (RR = 1.36, 95% CI: 1.06, 1.76) suggested that COX-2 inhibitors increased hematologic toxicities (grade ≥ 3) of chemotherapy

Conclusions

COX-2 inhibitors increased ORR of advanced NSCLC and had no impact on survival indices, but it may increase the risk of hematologic toxicities associated with chemotherapy.

Cisplatin in the modern era: The backbone of first-line chemotherapy for non-small cell lung cancer

The treatment of advanced non-small cell lung cancer (NSCLC) may be changing, but the cisplatin-based doublet remains the foundation of treatment for the majority of patients with advanced NSCLC. In this respect, changes in practice to various aspects of cisplatin use, such as administration schedules and the choice of methods and frequency of monitoring for toxicities, have contributed to an incremental improvement in patient management and experience. Chemoresistance, however, limits the clinical utility of this drug in patients with advanced NSCLC. Better understanding of the molecular mechanisms of cisplatin resistance, identification of predictive markers and the development of newer, more effective and less toxic platinum agents is required. In addition to maximising potential benefits from advances in molecular biology and associated therapeutics, modification of existing cisplatin-based treatments can still lead to improvements in patient outcomes and experiences.