Cyclooxygenase-2 expression in invasive breast carcinomas of no special type and correlation with pathological profiles suggest a role in tumorigenesis rather than cancer progression

Non-steroidal anti-inflammatory drugs and biomarkers: A new paradigm in colorectal cancer

Colorectal cancer is a sporadic, hereditary, or familial based disease in its origin, caused due to diverse set of mutations in large intestinal epithelial cells. Colorectal cancer (CRC) is a common and deadly disease that accounts for the 4^th worldwide highly variable malignancy. For the early detection of CRC, the most common predictive biomarker found endogenously are KRAS and ctDNA/cfDNA along with SEPT9 methylated DNA. Early detection and screening for CRC are necessary and multiple methods can be employed to screen and perform early diagnosis of CRC. Colonoscopy, an invasive method is most prevalent for diagnosing CRC or confirming the positive result as compared to other screening methods whereas several non-invasive techniques such as molecular analysis of breath, urine, blood, and stool can also be performed for early detection. Interestingly, widely used medicines known as non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation have reported chemopreventive impact on gastrointestinal malignancies, especially CRC in several epidemiological and preclinical types of research. NSAID acts by inhibiting two cyclooxygenase enzymes, thereby preventing the synthesis of prostaglandins (PGs) and causing NSAID-induced apoptosis and growth inhibition in CRC cells. This review paper majorly focuses on the diversity of natural and synthetic biomarkers and various techniques for the early detection of CRC. An approach toward current advancement in CRC detection techniques and the role of NSAIDs in CRC chemoprevention has been explored systematically. Several prominent governing mechanisms of the anti-cancer effects of NSAIDs and their synergistic effect with statins for an effective chemopreventive measure have also been discussed in this review paper.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

Prognostic Significance of Prostaglandin-Endoperoxide Synthase-2 Expressions in Human Breast Carcinoma: A Multiomic Approach

Prostaglandin-endoperoxide synthase-2 (PTGS2) plays a pivotal role in inflammation and carcinogenesis in human breast cancer. Our aim of the study is to find the prognostic value of PTGS2 in breast cancer. We conducted a multiomic analysis to determine whether PTGS2 functions as a prognostic biomarker in human breast cancer. We explored PTGS2 mRNA expressions using different public bioinformatics portals. Oncomine, Serial Analysis of Gene Expression (SAGE), GEPIA, ULCAN, PrognoScan database, Kaplan-Meier Plotter, bc-GenExMiner, USC XENA, and Cytoscape/STRING DB were used to identify the prognostic roles of PTGS2 in breast cancer. Based on the clinicopathological analysis, decreased PTGS2 expressions correlated positively with older age, lymph node status, the human epidermal growth factor receptor 2 (HER2) status (P < .0001), estrogen receptor (ER+) expression (P < .0001) Luminal A (P < .0001), and Luminal B (P < .0001). Interestingly, progesterone receptor (PR) (P < .0001) negative showed a high expression of PTGS2. Prostaglandin-endoperoxide synthase-2 was downregulated in breast cancer tissues than in normal tissues. In the PrognoScan database and, Kaplan-Meier Scanner, downregulated expressions of PTGS2 associated with poor overall survival (OS), relapse-free survival (RFS), and distant metastasis-free survival. The methylation levels were significantly higher in the Luminal B subtype. Through oncomine coexpressed gene analysis, we found a positive correlation between PTGS2 and interleukin-6 (IL-6) expression in breast cancer tissues. These results indicate that downregulated expressions of PTGS2 can be used as a promising prognostic biomarker and Luminal B hyper methylation may play an important role in the development of breast cancers. However, to clarify our results, extensive study is required.

The Presence of Cyclooxygenase 2, Tumor-Associated Macrophages, and Collagen Alignment as Prognostic Markers for Invasive Breast Carcinoma Patients

Inflammation, and the organization of collagen in the breast tumor microenvironment, is an important mediator of breast tumor progression. However, a direct link between markers of inflammation, collagen organization, and patient outcome has yet to be established. A tumor microarray of 371 invasive breast carcinoma biopsy specimens was analyzed for expression of inflammatory markers, including cyclooxygenase 2 (COX-2), macrophages, and several collagen features in the tumor nest (TN) or the tumor-associated stroma (TS). The tumor microarray cohort included females, aged 18 to 80 years, with a median follow-up of 8.4 years. High expression of COX-2 (TN), CD68 (TS), and CD163 (TN and TS) predicted worse patient overall survival (OS). This notion was strengthened by the finding from the multivariate analysis that high numbers of CD163⁺ macrophages in the TS is an independent prognostic factor. Overall collagen deposition was associated with high stromal expression of COX-2 and CD163; however, total collagen deposition was not a predictor for OS. Conversely, local collagen density, alignment and perpendicular alignment to the tumor boundary (tumor-associated collagen signature-3) were predictors of OS. These results suggest that in invasive carcinoma, the localization of inflammatory cells and aligned collagen orientation predict poor patient survival. Additional clinical studies may help validate whether therapy with selective COX-2 inhibitors alters expression of CD68 and CD163 inflammatory markers.

COX-2 Expression in Breast Carcinoma with Correlation to Clinicopathological Parameters

Objective: Breast carcinoma is the most common malignant tumor and the leading cause of carcinoma deaths in women. Its etiology is multifactorial, implicating reproductive factors, hormonal imbalances and genetic predispositions. Studies have shown that Cycloxygenase-2 (COX-2) plays an important role in the carcinogenesis and increased expression has been regarded as a poor prognostic factor. The objective of our study is 1. To study COX-2 expression in normal breast tissue, DCIS and invasive breast cancer. 2. To determine COX-2 expression with clinicopathological prognostic parameters. Methods: Radical mastectomy specimens were studied for COX-2 expression by immunohistochemistry in 50 patients diagnosed as breast carcinoma. COX-2 expression is quantified as IHS Score and separately calculated for normal breast epithelium near the tumor, DCIS and invasive areas. Relationship between COX-2 expression with various clinicopathological parameters was evaluated. Result: The results of our study suggest an association of the expression of COX-2 to the factors associated with poor prognosis in breast cancer, such as larger tumor size, positive lymph node status, higher T stage and N stage and lymphovascular invasion. There was a higher COX-2 expression in the DCIS component as compared to the invasive ductal carcinoma component and the adjoining breast epithelium. Conclusion: Our study established the role of COX-2 in carcinogenesis and its association with adverse prognostic factors.

The Impact of Dietary Polyphenols on COX-2 Expression in Colorectal Cancer

Polyphenols are natural compounds with high structural diversity whose common occurrence in plants renders them intrinsic dietary components. They are known to be secondary metabolites characterized by a wide spectrum of biological activities, and a growing body of evidence indicates they have anti-inflammatory potential. It is well known that inflammation plays a key role in many chronic diseases such as circulatory diseases, pulmonary diseases, autoimmune diseases, diabetes, cancer, and neurodegenerative diseases. Polyphenols influence the inflammatory process by controlling and inhibiting pro-inflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α, and cyclooxygenase-2 (COX-2) enzyme involved in the metabolism of arachidonic acid. Furthermore, polyphenols exhibit anti-inflammatory activity on many levels via NF-κB inhibition, and MAPK, iNOS, and growth factors regulation. This paper reviews the current state of knowledge concerning the potential of various dietary polyphenols to inhibit the effects of COX-2 in colon cancer, by examining the available evidence regarding the efficacy and safety of these compounds obtained from in vitro and animal studies.

Downregulation of mitochondrial cyclooxygenase-2 inhibits the stemness of nasopharyngeal carcinoma by decreasing the activity of dynamin-related protein 1

Cancer stem cells (CSCs) are a small subset of malignant cells, possessing stemness, with strong tumorigenic capability, conferring resistance to therapy and leading to the relapse of nasopharyngeal carcinoma (NPC). Our previous study suggested that cyclooxygenase-2 (COX-2) would be a novel target for the CSCs-like side population (SP) cells in NPC. In the present study, we further found that COX-2 maintained the stemness of NPC by enhancing the activity of mitochondrial dynamin-related protein 1 (Drp1), a mitochondrial fission mediator, by studying both sorted SP cells from NPC cell lines and gene expression analyses in NPC tissues. Using both overexpression and knockdown of COX-2, we demonstrated that the localization of COX-2 at mitochondria promotes the stemness of NPC by recruiting the mitochondrial translocation of p53, increasing the activity of Drp1 and inducing mitochondrial fisson. Inhibition of the expression or the activity of Drp1 by siRNA or Mdivi-1 downregulates the stemness of NPC. The present study also found that inhibition of mitochondrial COX-2 with resveratrol (RSV), a natural phytochemical, increased the sensitivity of NPC to 5-fluorouracil (5-FU), a classical chemotherapy drug for NPC. The underlying mechanism is that RSV suppresses mitochondrial COX-2, thereby reducing NPC stemness by inhibiting Drp1 activity as demonstrated in both the in vitro and the in vivo studies. Taken together, the results of this study suggest that mitochondrial COX-2 is a potential theranostic target for the CSCs in NPC. Inhibition of mitochondrial COX-2 could be an attractive therapeutic option for the effective clinical treatment of therapy-resistant NPC.

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A₂s (PLA₂s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA₂s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed.

Sensitivity of gastric cancer cells to chemotherapy drugs in elderly patients and its correlation with cyclooxygenase-2 expression

OBJECTIVE

To explore the sensitivity of gastric cancer cells to chemotherapy drugs in elderly patients and its correlation with cyclooxygenase-2 (COX-2) expression in cancer tissue.

MATERIALS AND METHODS

Forty-three elderly patients with gastric cancer (observation group) and 31 young patients with gastrointestinal tumors (control group) who were all diagnosed by pathology and underwent surgery in the 89th Hospital of Chinese People's Liberation Army were selected. Drug sensitivity testing of tumor cells in primary culture was carried out in both groups using a methyl thiazolyl tetrazolium (MTT) method, and the expression of COX-2 and the factors related to multi-drug resistance (MDR) in cancer tissue were assessed by immunohistochemistry.

RESULTS

The inhibition rates (IR) of vincristine (VCR), 5-fluorouracil (5-FU), oxaliplatin (L-OHP), mitomycin (MMC) and epirubicin (eADM) on tumor cells in the observation group were dramatically lower than in the control group, with statistical significance (P<0.05 or P<0.01). The positive rates of COX-2, glutathione s-transferase-π (GST-π) and P glycoprotein (P-gp) expression in cancer tissue in the observation group were all higher than in control group (P<0.05), while that of DNA topoisomerase IIα (TopoIIα) expression lower than in the control group (P<0.01). In the observation group, COX-2 expression in cancer tissue had a significantly-positive correlation with GST-π and P-gp (r=0.855, P=0.000; r=0.240, P=0.026), but a negative correlation with TopoIIα (r=-0.328, P=0.002). In the control group, COX-2 expression in cancer tissue was only correlated with P-gp positively (r=0.320, P=0.011). Bivariate correlation analysis displayed that COX-2 expression in cancer tissue in the observation group had a significantly-negative correlation with the IRs of 5-FU, L-OHP, paclitaxel (PTX) and eADM in tumor cells (r=-0.723, P=0.000; r=-0.570, P=0.000; r=-0.919, P=0.000; r=-0.781, P=0.000), but with hydroxycamptothecine (HCPT), VCR and 5-FU in the control group (r=-0.915, P=0.000; r=-0.890, P=0.000; r=-0.949, P=0.000).

CONCLUSIONS

Gastric cancer cells in elderly patients feature stronger MDR, which may be related to high COX-2 expression.