COX-2 overexpression in resected pancreatic head adenocarcinomas correlates with favourable prognosis

Arachidonic acid metabolism as a novel pathogenic factor in gastrointestinal cancers

Gastrointestinal (GI) cancers are a major global health burden, representing 20% of all cancer diagnoses and 22.5% of global cancer-related deaths. Their aggressive nature and resistance to treatment pose a significant challenge, with late-stage survival rates below 15% at five years. Therefore, there is an urgent need to delve deeper into the mechanisms of gastrointestinal cancer progression and optimize treatment strategies. Increasing evidence highlights the active involvement of abnormal arachidonic acid (AA) metabolism in various cancers. AA is a fatty acid mainly metabolized into diverse bioactive compounds by three enzymes: cyclooxygenase, lipoxygenase, and cytochrome P450 enzymes. Abnormal AA metabolism and altered levels of its metabolites may play a pivotal role in the development of GI cancers. However, the underlying mechanisms remain unclear. This review highlights a unique perspective by focusing on the abnormal metabolism of AA and its involvement in GI cancers. We summarize the latest advancements in understanding AA metabolism in GI cancers, outlining changes in AA levels and their potential role in liver, colorectal, pancreatic, esophageal, gastric, and gallbladder cancers. Moreover, we also explore the potential of targeting abnormal AA metabolism for future therapies, considering the current need to explore AA metabolism in GI cancers and outlining promising avenues for further research. Ultimately, such investigations aim to improve treatment options for patients with GI cancers and pave the way for better cancer management in this area.

Targeting inflammation as cancer therapy

Inflammation has accompanied human beings since the emergence of wounds and infections. In the past decades, numerous efforts have been undertaken to explore the potential role of inflammation in cancer, from tumor development, invasion, and metastasis to the resistance of tumors to treatment. Inflammation-targeted agents not only demonstrate the potential to suppress cancer development, but also to improve the efficacy of other therapeutic modalities. In this review, we describe the highly dynamic and complex inflammatory tumor microenvironment, with discussion on key inflammation mediators in cancer including inflammatory cells, inflammatory cytokines, and their downstream intracellular pathways. In addition, we especially address the role of inflammation in cancer development and highlight the action mechanisms of inflammation-targeted therapies in antitumor response. Finally, we summarize the results from both preclinical and clinical studies up to date to illustrate the translation potential of inflammation-targeted therapies.

Prognostic Value of COX-2, NF-κB, and Sp1 Tissue Expressions in Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is deadly cancer with a poor prognosis. Molecular prognostic markers are needed to predict the patient's survival. The cyclooxygenase-2 enzyme (COX-2) and its 2 major transcription factors--nuclear factorkappa B (NF-κB) and specificity protein 1 (Sp1)--are activated during inflammation caused by neoplasia. Several studies have investigated the association between the COX-2, NF-κB, and Sp1 tissue expressions with the patient's overall survival. Therefore, we conducted this systematic review and meta-analysis to evaluate those studies.

METHODS

We searched for relevant articles from the MEDLINE database through June 2020. Studies were eligible if they included dichotomized tissue protein expression status and the overall survival as the outcome. We used RevMan and ProMeta programs to perform the meta-analysis.

RESULTS

We identified 11 eligible studies. The meta-analysis showed that COX-2 tissue expression was associated with decreased overall survival (crude HR = 1.35; 95% CI, 1.05-1.74), although the result was not significant when controlling for other covariates. The NF-κB tissue expression was associated with decreased overall survival (crude HR = 2.18; 95% CI, 1.49-3.18), although it was not significant when controlling for other covariates. The Sp1 tissue expression showed significantly decreased overall survival even when adjusted with other covariates (aHR = 3.47; 95% CI, 1.52-7.94). The limitations included searching only for English publications and the substantial heterogeneity among the studies.

CONCLUSION

COX-2, NF-κB, and Sp1 tissue expressions have the potential to be used as prognostic markers in PDAC. Further studies are still needed to clarify the associations.

Current Studies of Aspirin as an Anticancer Agent and Strategies to Strengthen its Therapeutic Application in Cancer

Aspirin has emerged as a promising intervention in cancer in the past decade. However, there are existing controversies regarding the anticancer properties of aspirin as its mechanism of action has not been clearly defined. In addition, the risk of bleeding in the gastrointestinal tract from aspirin is another consideration that requires medical and pharmaceutical scientists to work together to develop more potent and safe aspirin therapy in cancer. This review presents the most recent studies of aspirin with regard to its role in cancer prevention and treatment demonstrated by highlighted clinical trials, mechanisms of action as well as approaches to develop aspirin therapy best beneficial to cancer patients. Hence, this review provides readers with an overview of aspirin research in cancer that covers not only the unique features of aspirin, which differentiate aspirin from other non-steroidal anti-inflammatory drugs (NSAIDs), but also strategies that can be used in the development of drug delivery systems carrying aspirin for cancer management. These studies convey optimistic messages on the continuing efforts of the scientist on the way of developing an effective therapy for patients with a low response to current cancer treatments.

Combined COX-2/PPARγ Expression as Independent Negative Prognosticator for Vulvar Cancer Patients

Vulvar cancer incidence numbers have been rising steadily over the past decades. Especially the number of young patients with vulvar cancer increased recently. Therefore, the need to identify new prognostic factors for vulvar carcinoma is more apparent. Cyclooxygenase-2 (COX-2) has long been an object of scientific interest in the context of carcinogenesis. This enzyme is involved in prostaglandin synthesis and the latter binds to nuclear receptors like PPARγ. Therefore, the aim of this study was to investigate COX-2- and PPARγ- expression in tissues of vulvar carcinomas and to analyze their relevance as prognostic factors. The cytoplasmatic expression of COX-2 as well as PPARγ is associated with a significantly reduced survival, whereas nuclear expression of PPARγ results in a better survival. Especially the combined expression of both COX-2 and PPARγ in the cytoplasm is an independent negative prognosticator for vulvar cancer patients.

Effect of Daikenchuto On Spontaneous Intestinal Tumors in ApcMin/+ Mice

Daikenchuto (TU-100) is herbal medicine which predominantly contains ginger, Japanese pepper, and ginseng. We investigated whether TU-100 can affect the composition of gut flora and intestinal tumor development using Apc^Min/+ mice, a murine model of intestinal tumor. Bacterial 16S rRNA sequencing and short-chain fatty acid analysis were performed on faecal samples. Tumor number and size were analysed. Any change in gene expression of the tumor tissues was assessed by real-time PCR. Principal coordinate analysis (PCoA) showed that the faecal microbiota cluster of TU-100-fed mice was different from the microbiota of control mice. However, no significant difference was observed in the concentration of short-chain fatty acids, tumor number, and gene expression levels between the two groups. Our data showed that TU-100 can affect the intestinal environment; however, it does not contribute in tumor progression or inhibition in our setting.

Effects of aspirin and non-steroidal anti-inflammatory drugs on the risk of cholangiocarcinoma: a meta-analysis

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) can suppress the proliferation of cholangiocarcinoma (CCA) cells in vitro through inhibition of cyclooxygenase-2. However, the effects of aspirin and NSAIDs on the risk of CCA remain unclear. We performed this meta-analysis to assess the risk of biliary tract cancers in patients who take aspirin and/or NSAIDs.

METHODS

A systematic review was conducted utilizing MEDLINE, EMBASE, Cochrane databases from inception through October 2017 to identify studies that assessed the association of aspirin and/or NSAIDs use with risk of biliary tract cancers including CCA, gallbladder cancer and ampulla of Vater cancer. Effect estimates from the studies were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Five observational studies with a total of 9 200 653 patients were enrolled. The pooled OR of CCA in patients with aspirin use was 0.56 (95% CI, 0.32-0.96). Egger's regression asymmetry test was performed and showed no publication bias for the association between aspirin use and CCA with P = 0.42. There was no significant association between NSAIDs use and CCA, with a pooled OR of 0.79 (95% CI, 0.28-2.21). One study showed a significant association between aspirin use and reduced risk of gallbladder cancer with OR of 0.37 (0.17-0.80). However, there was no significant association between aspirin and ampulla of Vater cancer with OR of 0.22 (0.03-1.65).

CONCLUSIONS

Our study demonstrates a significant association between aspirin use and a 0.56-fold decreased risk of CCA. However, there is no association between the use of NSAIDs and CCA.

Repurposing the anti-malarial drug dihydroartemisinin suppresses metastasis of non-small-cell lung cancer via inhibiting NF-κB/GLUT1 axis

Non-small-cell lung cancer (NSCLC) is an aggressive malignancy and long-term survival remains unsatisfactory for patients with metastatic and recurrent disease. Repurposing the anti-malarial drug dihydroartemisinin (DHA) has been proved to possess potent antitumor effect on various cancers. However, the effects of DHA in preventing the invasion of NSCLC cells have not been studied. In the present study, we determined the inhibitory effects of DHA on invasion and migration and the possible mechanisms involved using A549 and H1975 cells. DHA inhibited in vitro migration and invasion of NSCLC cells even in low concentration with little cytotoxicity. Additionally, low concentration DHA also inhibited Warburg effect in NSCLC cells. Mechanically, DHA negatively regulates NF-κB signaling to inhibit the GLUT1 translocation. Blocking the NF-κB signaling largely abolishes the inhibitory effects of DHA on the translocation of GLUT1 to the plasma membrane and the Warburg effect. Furthermore, GLUT1 knockdown significantly decreased the inhibition of invasion, and migration by DHA. Our results suggested that DHA can inhibit metastasis of NSCLC by targeting glucose metabolism via inhibiting NF-κB signaling pathway and DHA may deserve further investigation in NSCLC treatment.

Combination of celecoxib and PD184161 exerts synergistic inhibitory effects on gallbladder cancer cell proliferation

Cyclooxygenase-2 (COX-2) and extracellular signal-regulated kinase 1/2 (ERK1/2) may serve as potential targets in various types of cancer; however, the roles of these proteins in gallbladder carcinoma (GBC) have not been reported previously. In the present study, the expression levels of COX-2 and phospho (p)-ERK1/2 in GBC were examined and the biological activities of celecoxib and PD184161 (specific inhibitors of COX-2 and p-ERK1/2, respectively) on the proliferation, cell cycle and apoptosis of the GBC-SD and NOZ human GBC cell lines were evaluated by a series of in vitro and in vivo studies. COX-2 and p-ERK1/2 protein expression levels were found to be significantly elevated in GBC tissues as well as in GBC-SD and NOZ cells. Treatments with celecoxib and PD184161 significantly inhibited GBC-SD and NOZ cell growth in a concentration-dependent manner, and their combination produced a synergistic inhibitory effect. In addition, celecoxib and PD184161 significantly inhibited tumor growth in xenograft nude mice. Celecoxib treatment led to G1 arrest via the upregulation of p21 and p27 expression in GBC-SD and NOZ cells, whereas PD184161 did not affect cell cycle distribution. The combination of celecoxib and PD184161 was able to promote cell apoptosis by triggering a collapse of mitochondrial membrane potential and activating caspase-3-mediated apoptosis. In conclusion, COX-2 and p-ERK1/2 protein may serve as potential targets for GBC chemotherapy, and the combination of celecoxib and PD184161 could significantly inhibit GBC cell growth, induce cell G1 arrest and trigger cell apoptosis of GBC cells.

Drug repositioning for gynecologic tumors: a new therapeutic strategy for cancer

The goals of drug repositioning are to find a new pharmacological effect of a drug for which human safety and pharmacokinetics are established and to expand the therapeutic range of the drug to another disease. Such drug discovery can be performed at low cost and in the short term based on the results of previous clinical trials. New drugs for gynecologic tumors may be found by drug repositioning. For example, PPAR ligands may be effective against ovarian cancer, since PPAR activation eliminates COX-2 expression, arrests the cell cycle, and induces apoptosis. Metformin, an antidiabetic drug, is effective for endometrial cancer through inhibition of the PI3K-Akt-mTOR pathway by activating LKB1-AMPK and reduction of insulin and insulin-like growth factor-1 due to AMPK activation. COX-2 inhibitors for cervical cancer may also be examples of drug repositioning. PGE2 is induced in the arachidonate cascade by COX-2. PGE2 maintains high expression of COX-2 and induces angiogenic factors including VEGF and bFGF, causing carcinogenesis. COX-2 inhibitors suppress these actions and inhibit carcinogenesis. Combination therapy using drugs found by drug repositioning and current anticancer drugs may increase efficacy and reduce adverse drug reactions. Thus, drug repositioning may become a key approach for gynecologic cancer in drug discovery.

Associations between Cox-2 rs20417 and rs5275 polymorphisms and the risk of hepatocellular carcinoma: a meta analysis

Genetic polymorphisms of cyclooxygenase-2 (Cox-2) gene have been implicated in the susceptibility to hepatocellular carcinoma (HCC), but the findings from published studies are conflicting and inconclusive. To obtain a more precise estimate of the association of Cox-2 polymorphisms with HCC risk, we performed a meta-analysis of eight eligible case-control studies identified through an extensive online database search of PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang and Chinese Biomedicine Database; after exclusion, 2324 cases and 2604 controls were included. The pooled odds ratios with corresponding 95% confidence intervals were calculated to assess associations, using fixed- or random-effect models. In addition, subgroup analysis by ethnicity and sensitivity analysis were performed. Our results showed that the Cox-2 rs20417 (-765 G/C) polymorphism was not associated with HCC risk in the studied genetic contrast modes (C vs. G, GC vs. GG, and CC + GC vs. GG). No significant association was found with ethnic groups examined (P > 0.05). Similarly, no significant association of the Cox-2 rs5275 (+ 8473 T/C) polymorphism and HCC risk was found under any of the studied contrasts (C vs. T, TC vs. TT, CC vs. TT, CC + TC vs. TT, CC vs. TC + TT). The present meta-analysis, combining all currently available data, suggests no significant associations of either Cox-2 polymorphism with HCC risk. Further studies with a larger sample size are needed to determine the association in different ethnicities.