|Year : 2019 | Volume
| Issue : 2 | Page : 249-256
Expression of inflammatory molecules cyclooxygenase-2 and forkhead box protein 3 in Wilms’ tumor microenvironment and their clinicopathological significance
Maha M Guimei
Department of Pathology, Faculty of Medicine, Egypt
|Date of Submission||15-Jun-2019|
|Date of Acceptance||06-Nov-2019|
|Date of Web Publication||30-Sep-2020|
Source of Support: None, Conflict of Interest: None
Background and purpose The role of inflammation in cancer has been reported in various adult malignant neoplasms. Cyclooxygenase-2 (COX-2) is overexpressed in invasive breast carcinoma, colonic adenocarcinomas, as well as other tumors, and inhibitors of COX-2 have increasingly become therapeutic alternatives in many tumors. Forkhead box protein 3 (FOXP-3) transcription factor is important for the development of Tregs and hence maintenance of immunologic self-tolerance. Activity of Tregs is increased in lung cancer, gastric, and several adult-onset tumors, and they play a role in suppressing the antitumor immune responses. However, the exact role of these inflammatory molecules in pediatric malignancies especially Wilms’ tumor (WT) has not yet been fully addressed.
Aim The aim of the present study was to investigate the expression of the inflammatory molecules COX-2 and FOXP-3 in WTs and their possible association with the different clinicopathological parameters.
Patients and methods In this study, 21 formalin-fixed paraffin-embedded specimens of WTs were evaluated. Anaplasia [unfavorable histology (UFH)] was found in 31.6% of the studied tumors. Protein expression of COX-2 and FOXP-3 was investigated using immunohistochemistry. The degree of expression of both COX-2 and FOXP-3 expression was semiquantitatively assessed for each of the studied tumors using modified H-scoring.
Results The present study revealed that COX-2 was expressed in the cytoplasm of all studied cases (100%). Its expression was higher in anaplastic WT (UFH) (median H-score, 200) compared with tumors with favorable histology (median H-score, 160). However, this difference was not statistically significant (P=0.167). On the contrary, FOXP-3 expression in WT was mostly low. Its expression varied between an H-score of 10 and 130 (median, 20). No significant difference in expression was noted between favorable histology versus UFH tumors. The present study also demonstrated a significant positive association between expression of COX-2 and FOX-P3 in WTs (P=0.033).
Conclusion Our results show that COX-2 is strongly expressed in all WTs with a trend toward higher expression in UFH ones. Furthermore, the significant association between COX-2 expression and FOXP-3 expression in the studied cases suggests that inhibition of COX-2 may lead to an associated suppression of FOXP-3 activity and thereby enhancing the antitumor immune responses in these patient, which is an interesting finding that needs to be further explored.
Keywords: antitumor immune response, cyclooxygenase-2, favorable histology, forkhead box protein 3, tumor microenvironment, unfavorable histology, Wilms’, tumor
|How to cite this article:|
Guimei MM. Expression of inflammatory molecules cyclooxygenase-2 and forkhead box protein 3 in Wilms’ tumor microenvironment and their clinicopathological significance. Egypt J Pathol 2019;39:249-56
|How to cite this URL:|
Guimei MM. Expression of inflammatory molecules cyclooxygenase-2 and forkhead box protein 3 in Wilms’ tumor microenvironment and their clinicopathological significance. Egypt J Pathol [serial online] 2019 [cited 2021 Apr 15];39:249-56. Available from: http://www.xep.eg.net/text.asp?2019/39/2/249/296053
| Introduction and review of literature|| |
Wilms’ tumor (WT), or nephroblastoma, is the most common genitourinary malignancy in children (Dénes et al., 2013). It is characterized by the presence of persistent blastema, primitive glomeruli and tubules, together with supporting mesenchyme or stroma (Ritchey et al., 1994). It accounts for ∼6% of all childhood tumors, and its incidence corresponds to 1 in 10 000 children (SEER Cancer Statistics Review, 1975-2003, Ries et al. n.d., 2019). The majority of WTs are unilateral and sporadic, and only 1% of the cases are considered hereditary (Breslow et al., 2006). In spite of the great advances achieved in diagnosis and treatment of WT, the most important predictors of outcome in these children remain to be tumor histology and stage of the disease, according to which, treatment is determined (Ghanem et al., 2013).
In addition to the neoplastic cells, the complex and dynamic tumor microenvironment is composed of extracellular matrix, endothelial cells, immune cells, and a plethora of cytokines and growth factors (Pang et al., 2016). Importantly, inflammatory cells and inflammatory mediators are prominent constituents of the microenvironment in all tumors. The interplay between them and the different components in the tumor microenvironment is now being recognized as a key player in tumor progression, influencing growth, invasiveness, and metastatic potential (Ghanem et al., 2013; Zhu et al., 2012). The inflammation in the microenvironment has been identified as an oncogenic factor leading to tissue remodeling, angiogenesis, cancer cell survival, metastasis as well as immune evasion.
The role of an inflammatory microenvironment in tumor development has been investigated in many adult-onset malignancies, especially those for which inflammation is a known risk factor (Zhu et al., 2012). However, little is known about the role of an inflammatory microenvironment in the development and progression of childhood tumors. Targeting the immune system, either by potentiating immune responses or by inhibiting cancer cell-elicited immunosuppressive mechanisms (immunoediting), is currently at the forefront of cancer research.
Cyclooxygenase-2 (COX-2), also referred to as prostaglandin endoperoxide synthase 2 (PTGS2), metabolizes arachidonic acid and produces a number of biologically active prostaglandins (PGD2, PGE2, PGF2α, and PGI2) and thromboxane A2 (TXA2). There are three isoforms of COX enzymes: COX-1, COX-2, and COX-3 (Sharma et al., 2003); of which, COX-2 is known to be an inducible enzyme that is associated with inflammatory diseases as well as carcinogenesis. It is also suspected to promote angiogenesis, tissue invasion, and resistance to apoptosis (Nzeako et al., 2002; DeNardo et al., 2010). COX-2 protein expression was reported to be increased in several tumors including colorectal cancers (Fujino et al., 2002) as well as ovarian cancers, where higher COX-2 expression was associated with poorer survival rate, thus making COX-2 expression a potential prognostic marker of ovarian cancer (Sun et al., 2017).
In addition to its oncogenic role, COX-2/PGE2 is also suggested to play a role in modulating the immune response against tumors via several mechanisms; it inhibits proliferation of B and T lymphocytes (Harris et al., 2007), augments protumorigenic type 2 lymphocytes (Eruslanov et al., 2010) and promotes M2 macrophage differentiation (Li et al., 2014), induces Tregs, promotes CD4+ and CD8+ T cells differentiation in Tregs, and inhibits effector T cells in a COX-2-dependent manner (Yuan et al., 2010). COX-2/PGE(2) induction of Treg cells supports the cancer-mediated immune suppression, and the extent of COX-2 expression was found to be significantly associated with Tregs prevalence in the tumor microenvironment (Mahic et al., 2006).
The immune-suppressive activity of T-regulatory cells is driven by expression of the forkhead/winged helix (FOXP-3) gene (Rudensky, 2011, p. 3). The forkhead box protein 3 (FOXP-3) is a transcription factor that has a fundamental role in the regulation and development of the immune system as well as maintenance of immunological self-tolerance by suppressing self-reactive T cells (Hori et al., 2003). Considering that most tumor-associated antigens identified to date are antigenically normal self-constituents, it is likely that naturally occurring FOXP-3+ Treg cells hamper the antitumor immune responses in patients with cancer and represents an important cellular target to evoke and augment antitumor immunity (Liu et al., 2017). Although it was first described as restricted to hematopoietic lineages, recent studies have demonstrated FOXP-3 expression in several tissues, including tumor cells. This has been shown in non-small cell lung cancer, pancreatic cancer, melanoma, and breast tumors (Takenaka et al., 2013). Moreover, FOXP-3 expression in tumor cells could be an independent strong prognostic factor for distant metastasis in BC.
In view of these findings, and in order to learn more about the role the inflammatory microenvironment in the development of WT, the aim of the present study was to analyze the immunohistochemical expression of both COX-2 and FOXP-3 in WT in relation to the different clinicopathological characteristics hoping that this may aid the search for new possible molecular markers that could better stratify the patients into high-risk and low-risk groups for better fine tuning of their treatment.
| Patients and methods|| |
Twenty-one cases of WT were collected from the archives of the Pathology Department, Faculty of Medicine, Alexandria University, Egypt. Written informed consents were obtained from the parents of the patients included in the study. Formalin-fixed paraffin-embedded specimens were cut in 5-µm thick sections and stained with hematoxylin and eosin to confirm the diagnosis and the grade of tumor. The study included 14 cases of favorable histology (FH) and seven cases with unfavorable histology (UFH). Anaplasia was identified in the latter group according to the COG definition by the presence of a three-fold increase in nuclear size compared with adjacent nuclei, hyperchromasia, and multipolar mitotic figures. Eight (38%) cases had a stage I disease, six (29%) cases were stage II disease, five (24%) were stage III, and two (10%) were stage IV. The study was approved by the ethics committee of the College of Medicine, University of Alexandria.
Histology and immunohistochemistry of inflammatory and immune markers
Immunohistochemistry was performed using anti-COX-2 rabbit polyclonal antibody (Clone ab15191; Abcam, Cambridge, UK) and anti-FOXP-3 mouse monoclonal antibody [clone (2A11G9), sc-53876, Santa Cruz, California, USA] antibody. The Abcam detection kits were used (rabbit specific HRP/DAB detection kit, ab64162, and mouse specific HRP/DAB detection kit, ab64259; Abcam). Sections were deparaffinized and dehydrated. Microwave unmasking of antigens was performed for 20 min in 0.01 mol/l citrate buffer at 98°C (pH 6). The sections were then left to cool for 1 h. Endogenous peroxide was subsequently blocked with 3% hydrogen peroxide for 10 min, followed by washing for 5 min with phosphate buffer saline. The specimens were incubated overnight at 4°C with anti-COX-2 and FOXP-3 antibodies diluted at 1 : 100 and 1 : 50, respectively. They were then washed three times in phosphate buffer saline for 5 min each and incubated for 30 min with labeled-polymer-conjugated secondary antibody. Finally, they were washed and developed with 3,3-diaminobenzidine tetrahydrochloride for 5 min, lightly counterstained with hematoxylin (cas number 517-28-2; Sigma-Aldrich, St. Louis, Missouri, USA), dehydrated, and mounted. Positive and negative controls were included in all the runs. Tonsil tissue and human breast carcinoma tissue were used as positive controls for FOXP-3 and COX-2, respectively
Quantification of immune cells and inflammatory markers
A semiquantitative (modified H-score) method was used to assess the degree of positive staining. This method assigns an immunohistochemical H-score to each patient on a continuous scale of 0–300, based on the percentage of cells at different staining intensities visualized at different magnifications (Pirker et al., 2012). Cytoplasmic staining was scored according to four categories: 0 for ‘no staining,’ 1+ for ‘light staining visible only at high magnification,’ 2+ for ‘intermediate staining,’ and 3+ for ‘strong, dark staining, visible even at low magnification.’ The percentage of cells at different staining intensities was determined by visual assessment, with the score calculated using the formula, 1 Å∼ (% of 1 +cells)+2 Å∼ (% of 2+cells)+3 Å∼ (% of 3+cells), depending on the percentage of stained cells.
Data were entered using statistical package for the social science program for statistical analysis (SPSS version 21, Armonk, NY, USA). Data were entered as numerical or categorical as appropriate. Data were described using minimum, maximum, mean, SD, and 95% confidence interval of the mean for the normally distributed area. Categorical variables were described using frequency and percentage of total. Comparisons were carried out between two studied independent not normally distributed subgroups using Mann–Whitney U test. Comparisons were carried between more than two studied independent not normally distributed subgroups using Kruskal–Wallis test. χ2 test was used to test the association between qualitative variables. Fisher’s exact test and Monte Carlo correlation were carried out when indicated. Results were considered statistically significant when the P value was less than 0.05.
| Results|| |
The present study is a retrospective study of 21 formalin-fixed paraffin-embedded tissue specimens of WT. All patients had been treated by surgery followed with postoperative chemotherapy/radiotherapy in Alexandria University Hospital, Egypt, according to the NWTSG/COG guidelines. All data regarding patient age, tumor grade, tumor stage, as well as follow-up were retrieved from the archives of the pathology and oncology departments.
The patients’ ages ranged between 3 and 132 months, with a median age of 24 months. Ten (47.62%) out of the 21 cases showed the typical triphasic pattern on histology, whereas six (28.57%) had a biphasic pattern, and only five (23.81%) tumors had a monophasic pattern (blastemal only). Fourteen (66.67%) out of the 21 cases had FH, and seven (33.33%) cases showed UFH. Data concerning patients’ follow-up were retrieved from the patients’ records. The average follow-up was 2 years after the start of treatment. After those 2 years, only three patients developed recurrence and died from the disease, whereas the remaining 18 patients were alive and free of the disease.
Cyclooxygenase-2 expression in Wilms’ tumors
In the present study, COX-2 expression was noted in the cytoplasm of the tumor cells in all studied cases (100%). COX-2 expression score (as measured by modified H-scoring) varied between 60 and 300, with a median value of 170 in the different tumors. COX-2 expression was stronger and more evident in the epithelial compartment of the tumors (primitive tubules) compared with the stromal and blastemal areas, which both showed less expression ([Figure 1]).
|Figure 1 (a) Cytoplasmic expression of COX-2 in the primitive tubules of WT. (immunoperoxidase, ×200). (b) Strong cytoplasmic expression of COX-2 in the primitive tubules (thick arrows) compared with blastema in which less number of cells show positive staining (thin arrows) (immunoperoxidase, ×400). COX-2, cyclooxygenase-2; WT, Wilms’ tumor.|
Click here to view
Modified H-score for COX-2 expression was higher in UFH WTs (median H-score, 202) compared with tumors with low-grade tumors (FH), where the median H-score value was 160. Yet this difference was not statistically significant (P=0.167, Mann–Whitney U test). Similarly, COX-2 expression scores were higher in high-stage tumors (stages III and IV) compared with low-stage tumors (stages I and II); however, this difference was also not statistically significant (P=0.178, Mann–Whitney U test) ([Figure 2]).
|Figure 2 (a) COX-2 expression H-scores were higher in anaplastic WT (median H-score, 202) compared with favorable histology tumors (median H-score, 160) (P=0.167). (b) COX-2 expression scores was higher in high-stage tumors (median H-score, 208) compared with low-stage tumors (median H-score, 166) (P=0.178). COX-2, cyclooxygenase-2; WT, Wilms’ tumor.|
Click here to view
Forkhead box protein 3 expression in Wilms’ tumors
FOXP-3 expression was noted in all studied tumors. Its expression was noted in the nuclei of not only the tumor-associated immune cells but also in some tumor cells themselves. The FOXP-3 H-scores varied between a minimum of two, where only very few cells showed positive staining, and a maximum of only 130 in others. The median modified H-score was only 20, thus denoting that FOXP-3 expression was significantly less than COX-2 expression in the examined tumors ([Figure 3]).
|Figure 3 (a) FOXP-3 expression is noted in the nuclei of few tumor cells mostly in the primitive tubular and glomerular structures (arrows), whereas the majority of the tumor cells are negative for FOXP-3 (H-score of this case was 20) (immunoperoxidase, ×400). (b) Few tumor-infiltrating immune cells show positive nuclear expression of FOXP-3 (immunoperoxidase, ×200). FOX-3, forkhead box protein 3.|
Click here to view
Among the 14 cases that showed FH, FOXP-3 scores ranged between 2 and 130, with a median score of 20, compared with a median of 30 for cases with UFH. Therefore, there was no statistically significant difference between FH and UFH cases regarding FOXP-3 expression. Furthermore, FOXP-3 expression did not show any statistically significant correlation with the age, sex, or tumor stage ([Figure 4]).
|Figure 4 (a) FOXP-3 expression (H-scores) in FH (low grade) and UFH (high grade) WTs, (P=0.470). (b) FOXP-3 expression scores in WTs with low-stage and high-stage tumors (P=0.518). FH, favorable histology; FOX-3, forkhead box protein 3; UFH, unfavorable histology; WT, Wilms’ tumor.|
Click here to view
All cases that showed a high COX-2 expression showed a simultaneously high expression of FOXP-3. Thus, a statistically significant positive correlation was found between COX-2 and FOXP-3 expression in the studied cases (t=0.361, P=0.033) ([Figure 5]).
|Figure 5 A statistically significant positive correlation between COX-2 (H-scores) and FOXP-3 (H-scores) in the studied cases (t=0.361, P=0.033). COX-2, cyclooxygenase-2; FOX-3, forkhead box protein 3.|
Click here to view
Diagnostic test accuracy analysis showed that COX-2 H-score was a statistically insignificant discriminator of occurrence of death, with area under the receiver operating characteristic curve (area under the curve) of 0.500 (95% confidence interval, 0.277–0.723) (Z=0.000, P=1.000). Similarly, FOXP-3 H-score was not found to be a statistically significant discriminator of occurrence of death, with area under the receiver operating characteristic curve (area under the curve) of 0.639 (95% confidence interval, 0.403–0.834) (Z=0.560, P=0.5754).
| Discussion|| |
In the past decade, several studies have pointed to a significant role of an inflammatory tumor microenvironment in adult-onset cancers. It has been suggested to play a role in the establishment as well as the progression of many tumors (Dénes et al., 2013). However, the contribution of the inflammatory microenvironment in childhood malignancies has not yet been fully addressed. We have investigated the expression of two important inflammatory molecules, COX-2 and FOXP-3, in 21 cases of WT.
In the present study, the expression of COX-2 was noted in tumor cells of all the studied cases, as well as in all compartments of the tumor: epithelial, stromal, and blastema. These results are in accordance with a previous comparative study that had investigated COX-2 expression in five cases of WT in comparison with adult tumors and had reported that expression of COX-2) was more localized in the stroma and was associated with infiltration of tumor-associated macrophages (TAM) (Maturu et al., 2014). TAM infiltration is known to be induced by COX-2 in the tumor microenvironment, especially in the tumor stroma, and TAMs can also induce expression of COX-2 (Hou et al., 2011). The abundant COX-2 expression in WTs could be attributed to several factors; one of these factors is the presence of infiltrating immune cells within the tumor stroma that express COX-2. Moreover, the abundant tumor fibroblasts in the stromal compartment could be generating COX-2 in response to macrophage infiltration or the inflammatory tumor microenvironment.
The present study also identified a trend toward a higher expression of COX-2 in higher grade tumors (UFH) as shown by higher H-scores of COX-2 expression in UFH tumors compared with FH tumors. This is a relatively novel finding that places COX-2 expression as an important prognostic marker in WT. In spite of the great advances in the diagnostic and therapeutic techniques, the presence of histological anaplasia still remains the most important determinant of prognosis and response to therapy in patients with WT, and specific disease biomarkers that could help stratify high-risk from low-risk patients, and therefore fine-tune management, are in great demand.
In the past decade, COX-2 overexpression has been reported in several human cancers, including breast, lung, skin, colon, bone, cervical, as well as esophageal tumors and was reported to have a poor prognostic significance (Han et al., 2014; Pang et al., 2016). In colon cancer, high COX-2 protein expression was significantly correlated with tumor size, infiltration depth, Duke’s stage, tumor differentiation, distant metastasis, and lymph node metastasis, and both COX-2 and HER-2 were found to be important markers for invasion and metastasis in colorectal cancer (Wu and Sun, 2015, p. 2). COX-2 mediates these oncogenic effects through numerous signaling pathways, including activation of vascular endothelial growth factor, which leads to increased cell proliferation and angiogenesis (Xu et al., 2014). It was also mentioned that there is increased expression of the proto-oncogenes, BCL-2, and the epidermal growth factor receptor, and this occurs through the activation of the mitogen-activated protein kinase and the phosphoinositide 3-kinase/AKT pathway, respectively (Buchanan et al., 2003). In addition, COX-2 increases the transcriptional activity of the antiapoptotic mediator nuclear factor κB, activates matrix metalloproteases (MMP-2 andMMP-9), and suppresses the production of interleukin-12, leading to immunosuppression (Pang et al., 2016).
In the present study, FOXP-3 expression was observed in tumor cells as well as in tumor-infiltrating immune cells in all studied cases of WT. However, the level and the degree of expression was relatively low compared with COX-2 expression in the same tumors, as shown by the relatively low H-scores for FOXP-3. It is well established that FOXP-3 plays a key role in Treg function and is an obligate marker of CD4+CD25+ Tregs. FOXP-3+ Tregs exert an immune suppressive influence by expression of cytokines such as interleukin-10 and transforming growth factor-b (Weiner, 2001). A high density of tumor-infiltrating FOXP-3+ Treg in tumor specimen has been associated with poor outcome in various solid tumors, including pancreatic (Hiraoka et al., 2006) and hepatocellular carcinoma (Kobayashi et al., 2007). Therefore, the relatively low expression of FOXP-3 in WT goes hand in hand with the relatively good prognosis of this neoplasm.
Similar to our results, the expression of FOXP-3 has not been restricted to tumor immune cells; it has been demonstrated in the tumor cells themselves in several tumors, including breast cancers (Ladoire et al., 2011), lung (Tao et al., 2012), and thyroid carcinomas (Cunha et al., 2012). In colorectal cancer, high FOXP-3 expression in tumor cells and not in tumor-infiltrating lymphocytes was associated with poor prognosis compared with patients with low FOXP-3 expression (Kim et al., 2013). The expression of FOXP-3 by cancer cells enabled them to downregulate effector T-cell responses directed against the tumor. This would give clinical evidence for an effective mechanism of a direct tumor-derived evasion from immunological destruction in CRC.The expression of FOXP-3 in the studied cases showed a significant positive association with COX-2 expression levels. In accordance with our findings, it has been previously suggested that COX-2-PGE2 signal pathway suppressed dendritic cells, natural killer, T cells, and type-1 immunity, but promoted type 2 immunity leading to tumor immune evasion and resistance to cancer immunotherapy (Liu et al., 2015). Similarly, a study by Baratelli et al. (2005) has demonstrated that PGE2, a product of COX-2, upregulated FOXP-3 at both mRNA and protein levels and enhanced FOXP-3 promoter activity in human lymphocytes). Another study on gastric carcinoma has demonstrated that an elevated FOXP-3 expression in tumor-infiltrating Treg cells correlated with COX-2 and PGE2 expression and was associated with a higher TNM stage. This effect was reversed by COX inhibitors and PGE2 receptor-specific antagonists (Yuan et al., 2010, p. 3).
| Conclusion|| |
Our data therefore demonstrate a strong expression of COX-2 in WT with higher expression levels noted in the more aggressive UFH type. COX-2 expression was also associated with FOXP-3 expression, which, in turn, points to a possible role of COX-2 in upregulating FOXP-3 and thereby inhibiting the immune response against the tumor cells. COX-2 inhibitors may thus be beneficial in the treatment of WT especially those with UFH by overcoming FOXP-3-dependent immune suppression.
However, the results of this study need to be further validated on a large sample of cases as well as address the exact molecular events underlying this association.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Baratelli F, Lin Y, Zhu L, Yang SC, Heuzé-Vourc’h N, Zeng G, Dubinett SM (2005). Prostaglandin E2 induces FOXP3 gene expression and T regulatory cell function in human CD4+ T Cells. J Immunol 175:1483–1490.
Breslow NE, Beckwith JB, Perlman EJ, Reeve AE (2006). Age distributions, birth weights, nephrogenic rests, and heterogeneity in the pathogenesis of Wilms tumor. Pediatr Blood Cancer 47:260–267.
Buchanan FG, Wang D, Bargiacchi F, DuBois RN (2003). Prostaglandin E2 regulates cell migration via the intracellular activation of the epidermal growth factor receptor. J Biol Chem 278:35451–35457.
Cunha LL, Morari EC, Nonogaki S, Soares FA, Vassallo J, Ward LS (2012). Foxp3 expression is associated with aggressiveness in differentiated thyroid carcinomas. Clinics 67:483–488.
DeNardo DG, Andreu P, Coussens LM (2010). Interactions between lymphocytes and myeloid cells regulate pro- versus anti-tumor immunity. Cancer Metastasis Rev 29:309–316.
Dénes FT, Duarte RJ, Cristófani LM, Lopes RI (2013). Pediatric genitourinary oncology. Front Pediatr. 1:48.
Eruslanov E, Daurkin I, Ortiz J, Vieweg J, Kusmartsev S (2010). Pivotal advance: tumor-mediated induction of myeloid-derived suppressor cells and M2-polarized macrophages by altering intracellular PGE₂ catabolism in myeloid cells. J Leuk Biol 88:839–848.
Fujino H, West KA, Regan JW (2002). Phosphorylation of glycogen synthase kinase-3 and stimulation of T-cell factor signaling following activation of EP2 and EP4 prostanoid receptors by prostaglandin E2. J Biol Chem 277:2614–2619.
Ghanem MA, van der Kwast TH, Molenaar WM, Safan MA, Nijman RJ, van Steenbrugge GJ (2013). The predictive value of immunohistochemical markers in untreated Wilms’ tumour: are they useful?. World J Urol 31:811–816.
Han JA, Kim JY, Kim JI (2014). Analysis of gene expression in cyclooxygenase-2-overexpressed human osteosarcoma cell lines. Genom Inform 12:247–253.
Harris RE, Beebe-Donk J, Alshafie GA (2007). Cancer chemoprevention by cyclooxygenase 2 (COX-2) blockade: results of case control studies. Subcell Biochem 42:193–212.
Hiraoka N, Onozato K, Kosuge T, Hirohashi S (2006). Prevalence of FOXP3+ regulatory T cells increases during the progression of pancreatic ductal adenocarcinoma and its premalignant lesions. Clin Cancer Res 12:5423–5434.
Hori S, Nomura T, Sakaguchi S (2003). Control of regulatory T cell development by the transcription factor Foxp3. Science 299:1057–1061.
Hou Z, Falcone DJ, Subbaramaiah K, Dannenberg AJ (2011). Macrophages induce COX-2 expression in breast cancer cells: role of IL-1β autoamplification. Carcinogenesis 32:695–702.
Kim M, Grimmig T, Grimm M, Lazariotou M, Meier E, Rosenwald A, Gasser M (2013). Expression of Foxp3 in colorectal cancer but not in treg cells correlates with disease progression in patients with colorectal cancer. PLoS One 8:e53630.
Kobayashi N, Hiraoka N, Yamagami W, Ojima H, Kanai Y, Kosuge T, Hirohashi S (2007). FOXP3+ regulatory T cells affect the development and progression of hepatocarcinogenesis. Clin Cancer Res 13:902–911.
Ladoire S, Arnould L, Mignot G, Coudert B, Rébé C, Chalmin F, Ghiringhelli F (2011). Presence of Foxp3 expression in tumor cells predicts better survival in HER2-overexpressing breast cancer patients treated with neoadjuvant chemotherapy. Breast Cancer Res Treat 125:65–72.
Li Q, Liu L, Zhang Q, Liu S, Ge D, You Z (2014). Interleukin-17 indirectly promotes M2 macrophage differentiation through stimulation of COX-2/PGE2 pathway in the cancer cells. Cancer Res Treat 46:297–306.
Liu B, Qu L, Yan S (2015). Cyclooxygenase-2 promotes tumor growth and suppresses tumor immunity. Cancer Cell Int 15:106.
Liu S, Zhang C, Zhang K, Gao Y, Wang Z, Li X, Hao Q (2017). FOXP3 inhibits cancer stem cell self-renewal via transcriptional repression of COX2 in colorectal cancer cells. Oncotarget 8:44694–44704.
Mahic M, Yaqub S, Johansson CC, Taskén K, Aandahl EM (2006). FOXP3+CD4+CD25+ adaptive regulatory T cells express cyclooxygenase-2 and suppress effector T cells by a prostaglandin E2-dependent mechanism. J Immunol 177:246–254.
Maturu P, Overwijk WW, Hicks J, Ekmekcioglu S, Grimm EA, Huff V (2014). Characterization of the inflammatory microenvironment and identification of potential therapeutic targets in Wilms tumors. Transl Oncol 7:484–492.
Nzeako UC, Guicciardi ME, Yoon JH, Bronk SF, Gores GJ (2002). COX-2 inhibits Fas-mediated apoptosis in cholangiocarcinoma cells. Hepatology (Baltimore, Md) 35:552–559.
Pang LY, Hurst EA, Argyle DJ (2016). Cyclooxygenase-2: A Role in Cancer Stem Cell Survival and Repopulation of Cancer Cells during Therapy. Stem Cells Int 2016; 2048731.
Pirker R, Pereira JR, Von Pawel J, Krzakowski M, Ramlau R, de Marinis F et al.
(2012). EGFR expression as a predictor of survival for first-line chemotherapy plus cetuximab in patients with advanced non-small-cell lung cancer: analysis of data from the phase 3 FLEX study. Lancer Oncol 13:33–42.
Ritchey ML, Pringle KC, Breslow NE, Takashima J, Moksness J, Zuppan CW, Kelalis PP (1994). Management and outcome of inoperable Wilms tumor. A report of National Wilms Tumor Study-3. Ann Surg 220:683–690.
Rudensky AY (2011). Regulatory T cells and Foxp3. Immunol Rev 241:260–268.
Ries LAG, Harkins D, Krapcho M, Mariotto A, Miller BA, Feuer EJ et al.
(2006). SEER Cancer Statistics Review, 1975-2003. Bethesda, MD: National Cancer Institute.
Sharma S, Stolina M, Yang SC, Baratelli F, Lin JF, Atianzar K, Dubinett SM (2003). Tumor cyclooxygenase 2-dependent suppression of dendritic cell function. Clin Cancer Res 9:961–968.
Sun H, Zhang X, Sun D, Jia X, Xu L, Qiao Y, Jin Y (2017). COX-2 expression in ovarian cancer: an updated meta-analysis. Oncotarget 8:88152–88162.
Takenaka M, Seki N, Toh U, Hattori S, Kawahara A, Yamaguchi T, Kage M (2013). FOXP3 expression in tumor cells and tumor-infiltrating lymphocytes is associated with breast cancer prognosis. Mol Clin Oncol 1:625–632.
Tao H, Mimura Y, Aoe K, Kobayashi S, Yamamoto H, Matsuda E, Ueoka H (2012). Prognostic potential of FOXP3 expression in non-small cell lung cancer cells combined with tumor-infiltrating regulatory T cells. Lung Cancer (Amsterdam, Netherlands) 75:95–101.
Weiner HL (2001). Induction and mechanism of action of transforming growth factor-beta-secreting Th3 regulatory cells. Immunol Rev 182 207–214.
Wu QB, Sun GP (2015). Expression of COX-2 and HER-2 in colorectal cancer and their correlation. World J Gastroenterol 21:6206–6214.
Xu L, Stevens J, Hilton MB, Seaman S, Conrads TP, Veenstra TD, Croix B St (2014). COX-2 Inhibition potentiates anti-angiogenic cancer therapy and prevents metastasis in preclinical models. Sci Transl Med 6:242ra84.
Yuan XL, Chen L, Li MX, Dong P, Xue J, Wang J, Xu D (2010). Elevated expression of Foxp3 in tumor-infiltrating Treg cells suppresses T-cell proliferation and contributes to gastric cancer progression in a COX-2-dependent manner. Clin Immunol. 134:277–288.
Zhu Z, Shen Z, Xu C (2012). Inflammatory pathways as promising targets to increase chemotherapy response in bladder cancer. Mediators Inflamm 2012:528690.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]