Cyclooxygenase-2 inhibition inhibits PI3K/AKT kinase activity in epithelial ovarian cancer

Acetylsalicylic Acid with Ascorbate: A Promising Combination Therapy for Solid Tumors

BACKGROUND AND OBJECTIVE

Cancer is a deadly disease with high mortality rates in developing countries. A recent preclinical study found promising results in treating hepatocellular carcinoma (HCC) by combining acetylsalicylic acid (ASA) and ascorbate (AS), which might offer a safer alternative to expensive clinical chemotherapeutics; however, the impact of this combination on other tumors remains unexplored. Therefore, this study aims to investigate the effectiveness of combining ASA and AS in treating Ehrlich solid tumors.

METHODS

Eighty female Swiss albino mice were divided into eight groups (10 mice/group): four healthy groups (healthy, AS, ASA, and AS+ASA) and four groups with carcinoma (Ehrlich ascites carcinoma [EAC], EAC+AS, EAC+ASA, and EAC+AS+ASA). AS was injected intraperitoneally (4 g/kg) daily for 10 days, whereas ASA was ingested orally at 60 mg/kg/day for 10 days. Carcinoma was induced by subcutaneous injection of 1×106 EAC cells/mouse once. Treatment of carcinoma started after 10 days of tumor inoculation. Blood, livers, and tumors were obtained, and tumor weights, volumes, and levels of hemoglobin, aminotransferases, albumin, bilirubin, urea, creatinine, lipid profile, malondialdehyde, nitric oxide, glutathione, catalase, total antioxidant capacity, lactate dehydrogenase, and creatine kinase were estimated. The percentage increase in lifespan was also assessed.

RESULTS

Tumor treatment alleviated tumor burden. Tumor size was reduced, lifespan increased, organs (liver, kidney, and heart) functions adjusted, hemoglobin, lipid profile improved, and oxidative stress decreased. Combining ASA with AS showed more effective antitumor effects than only ASA or AS alone.

CONCLUSION

After more validation research, combining ASA with AS may provide benefit in cancer treatment.

Impact of aspirin use on rates of metastasis in patients with esophageal cancer: insights from the National Inpatient Sample

Despite advancing treatment methods, esophageal cancer (EC) maintains a high mortality rate and poor prognosis. Through various mechanisms, aspirin has been suggested to have a chemopreventive effect on EC. However, the long-term impact, particularly regarding the rate of metastasis, needs to be further elucidated. NIS 2016-2020 was used to identify adult patients (age > 18 years) with EC using ICD-10 codes. Patients with missing demographics and mortality were excluded. Patients were stratified into two groups based on aspirin use. Data were collected on patient demographics, Elixhauser Comorbidity Index (ECI), and comorbidities (hypertension, chronic pulmonary disease, coronary artery disease (CAD), chronic kidney disease (CKD), congestive heart failure (CHF), coagulopathy, alcohol use, smoking, and obesity). The outcomes studied were rates of total metastasis, gastrointestinal (GI) metastasis, non-GI metastasis, and lymphoid metastasis. Multivariate logistic regression analysis was performed to evaluate the impact of aspirin use on various metastases after adjusting for patient demographics, comorbidities, and ECI. Out of 190,655 patients, 20,650 (10.8%) patients were aspirin users. Majority of the patients in the aspirin group were aged > 65 years (74.7%), males (82.1%), White race (84%), and had medicare insurance (71%). There was a higher incidence of diabetes, hypertension, chronic pulmonary disease, CAD, CKD, CHF, and smoking in aspirin users than non-aspirin users. Patients with aspirin users had a lower incidence of metastasis (28.9% vs. 38.7%, P < 0.001), GI metastasis (14.2% vs. 20.6%, P < 0.001), non-GI metastasis (15.1% vs. 22%, P < 0.001), and lymphoid metastasis (8.9% vs. 11.3%, P < 0.001) than non-aspirin users. After adjusting for confounding factors, patients with aspirin use had lower odds of having metastasis (aOR-0.73, 95% CI-0.70-0.77, P < 0.001). Our study noted that aspirin use is associated with a reduction in the rate of metastasis in patients with EC. These studies support the use of aspirin in patients with EC and suggest the need for further studies to understand the mechanism by which aspirin use reduces metastasis in patients with EC.

Aspirin and Cancer Survival: An Analysis of Molecular Mechanisms

The benefit of aspirin on cancer survival is debated. Data from randomized clinical trials and cohort studies are discordant, although a meta-analysis shows a clear survival advantage when aspirin is added to the standard of care. However, the mechanism by which aspirin improves cancer survival is not clear. A PubMed search was carried out to identify articles reporting genes and pathways that are associated with aspirin and cancer survival. Gene ontology and pathway enrichment analysis was carried out using web-based tools. Gene-gene and protein-protein interactions were evaluated. Crosstalk between pathways was identified and plotted. Forty-one genes were identified and classified into primary genes (PTGS2 and PTGES2), genes regulating cellular proliferation, interleukin and cytokine genes, and DNA repair genes. The network analysis showed a rich gene-gene and protein-protein interaction between these genes and proteins. Pathway enrichment showed the interleukin and cellular transduction pathways as the main pathways involved in aspirin-related survival, in addition to DNA repair, autophagy, extracellular matrix, and apoptosis pathways. Crosstalk of PTGS2 with EGFR, JAK/AKT, TP53, interleukin/TNFα/NFκB, GSK3B/BRCA/PARP, CXCR/MUC1, and WNT/CTNNB pathways was identified. The results of the present study demonstrate that aspirin improves cancer survival by the interplay of 41 genes through a complex mechanism. PTGS2 is the primary target of aspirin and impacts cancer survival through six primary pathways: the interleukin pathway, extracellular matrix pathway, signal transduction pathway, apoptosis pathway, autophagy pathway, and DNA repair pathway.

Uncovering the key pharmacodynamic material basis and possible molecular mechanism of extract of Epimedium against liver cancer through a comprehensive investigation

ETHNOPHARMACOLOGICAL RELEVANCE

Liver cancer is a worldwide malignant tumor, and currently lacks effective treatments. Clinical studies have shown that epimedium (YYH) has therapeutic effects on liver cancer, and some of its prenylflavonoids have demonstrated anti-liver cancer activity through multiple mechanisms. However, there is still a need for systematic research to uncover the key pharmacodynamic material basis and mechanism of YYH.

AIM OF THE STUDY

This study aimed to screen the anti-cancer material basis of YYH via integrating spectrum-effect analysis with serum pharmacochemistry, and explore the multi-target mechanisms of YYH against liver cancer by combining network pharmacology with metabolomics.

MATERIALS AND METHODS

The anti-cancer effect of the extract of YYH (E-YYH) was first evaluated in mice with xenotransplantation H22 tumor cells burden and cultured hepatic cells. Then, the interaction between E-YYH compounds and the cytotoxic effects was revealed through spectrum-effect relationship analysis. And the cytotoxic effects of screened compounds were verified in hepatic cells. Next, UHPLC-Q-TOF-MS/MS was employed to identify the absorbed components of E-YYH in rat plasma to distinguish anti-cancer components. Subsequently, network pharmacology based on anti-cancer materials and metabolomics were used to discover the potential anti-tumor mechanisms of YYH. Key targets and biomarkers were identified and pathway enrichment analysis was performed.

RESULTS

The anti-cancer effect of E-YYH was verified through in vitro and in vivo experiments. Six anti-cancer compounds in plasma (icariin, baohuoside Ⅰ, epimedin C, 2″-O-rhamnosyl icariside Ⅱ, epimedin B and sagittatoside B) were screened out by spectrum-effect analysis. Forty-five liver-cancer-related targets were connected with these compounds. Among these targets, PTGS2, TNF, NOS3 and PPARG were considered to be the potential key targets preliminarily verified by molecular docking. Meanwhile, PI3K/AKT signaling pathway and arachidonic acid metabolism were found to be associated with E-YYH's efficacy in network pharmacology and metabolomics analysis.

CONCLUSIONS

Our research revealed the characteristics of multi-component, multi-target and multi-pathway mechanism of E-YYH. This study also provided an experimental basis and scientific evidence for the clinical application and rational development of YYH.

Primary targeted medical therapy for management of bilateral head and neck lymphatic malformations in infants

OBJECTIVES

Patients born with bilateral head and neck lymphatic malformations (BHNLMs) often require multiple invasive treatments, including tracheostomy. We hypothesized that primary targeted medical therapy (pTMT) with diagnostic needle aspiration reduces the need for invasive therapy such as surgical resection and/or sclerotherapy.

METHODS

Retrospective case review was performed of infants with BHNLMs (Grade 2 or De Serres stage IV and V) treated only at our institution from 2000 to 2021. Patients were divided into two cohorts: those managed with pTMT and those managed with observation, sclerotherapy, or surgical intervention (non-pTMT). Data regarding interventions, clinical outcomes, morbidity, and mortality were analyzed with descriptive statistics.

RESULTS

Nine children with BHNLMs met inclusion criteria. Three (33%) were in the pTMT cohort and six (66%) were non-pTMT. Eight (89%) malformations were genotyped, and all demonstrated hotspot PIK3CA variants. All pTMT patients had sirolimus initiated in the first month of life and underwent needle aspiration of malformation cyst fluid for cell-free DNA samples. All pTMT patients tolerated medical therapy. For the non-pTMT cohort, primary treatment included none (deceased, n = 1, 17%), observation with needle aspiration (n = 1, 17%), surgical resection (n = 2, 33%), or combination surgery and sclerotherapy (n = 2, 33%). Intubation duration, intensive care and initial hospital length of stay were not different between cohorts. Four non-pTMT patients (67%) required tracheostomy, and two (33%) died prior to discharge. All pTMT patients survived and none required tracheostomy. Non-pTMT patients required a median of two invasive therapies prior to discharge (IQR 1-4) and a mean total of 13 over the course of their lifetime (IQR 1-16), compared to the pTMT group who did not require any lifetime invasive therapy, even after initial pTMT and discharge home.

CONCLUSION

This study compares patients with BHNLMs (Grade 2) treated with pTMT versus those treated with observation or invasive therapy. Patients treated with pTMT required no surgical or invasive procedural treatment of their malformations, no tracheostomy placement, no unplanned readmissions after discharge, and had no mortalities. Needle aspiration was useful as a therapeutic adjunct for cell-free DNA diagnosis of PIK3CA variants, which guided TMT.

Aspirin and cancer: biological mechanisms and clinical outcomes

Evidence on aspirin and cancer comes from two main sources: (1) the effect of aspirin upon biological mechanisms in cancer, and (2) clinical studies of patients with cancer, some of whom take aspirin. A series of systematic literature searches identified published reports relevant to these two sources. The effects of aspirin upon biological mechanisms involved in cancer initiation and growth appear to generate reasonable expectations of effects upon the progress and mortality of cancer. Clinical evidence on aspirin appears overall to be favourable to the use of aspirin, but evidence from randomized trials is limited, and inconsistent. The main body of evidence comes from meta-analyses of observational studies of patients with a wide range of cancers, about 25% of whom were taking aspirin. Heterogeneity is large but, overall, aspirin is associated with increases in survival and reductions in metastatic spread and vascular complications of different cancers. It is important that evaluations of aspirin used as an adjunct cancer treatment are based upon all the available relevant evidence, and there appears to be a marked harmony between the effects of aspirin upon biological mechanisms and upon the clinical progress of cancer.

Aspirin promotes RSL3-induced ferroptosis by suppressing mTOR/SREBP-1/SCD1-mediated lipogenesis in PIK3CA-mutant colorectal cancer

Ferroptosis, a new form of regulated cell death triggered by the iron-dependent peroxidation of phospholipids, is associated with cellular metabolism, redox homeostasis, and various signaling pathways related to cancer. Aspirin is a widely used non-steroidal anti-inflammatory drug (NSAID) and has been reported to show therapeutic benefit in cancers harboring oncogenic PIK3CA, which encodes the catalytic p110α subunit of phosphoinositide 3-kinase (PI3K). In this study, we found that aspirin sensitized cancer cells harboring oncogenic activation of PIK3CA to ferroptosis induction. Mechanistically, aspirin inhibited protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling, suppressed downstream sterol regulatory element-binding protein 1 (SREBP-1) expression, and attenuated stearoyl-CoA desaturase-1 (SCD1)-mediated lipogenesis of monounsaturated fatty acids, thus promoting RSL3-induced ferroptosis in colorectal cancer (CRC) cells. Moreover, genetic ablation of SREBP-1 or SCD1 conferred cancer cells greater sensitivity to ferroptosis induction. Conversely, ectopic expression of SREBP-1 or SCD1 restored ferroptosis resistance in CRC cells and abolished the effect of aspirin on RSL3-induced cytotoxicity. Additionally, the synergistic effects of aspirin and RSL3 were confirmed in a xenograft mouse model. The combined use of aspirin and RSL3 resulted in significant tumor suppression. Our work demonstrated that aspirin enhanced the cytotoxic effect of RSL3 in PIK3CA-mutant cancers, and the combination of aspirin and ferroptosis inducer displayed promising therapeutic effects in cancer treatment.

Aspirin sensitivity of PIK3CA-mutated Colorectal Cancer: potential mechanisms revisited

PIK3CA mutations are amongst the most prevalent somatic mutations in cancer and are associated with resistance to first-line treatment along with low survival rates in a variety of malignancies. There is evidence that patients carrying PIK3CA mutations may benefit from treatment with acetylsalicylic acid, commonly known as aspirin, particularly in the setting of colorectal cancer. In this regard, it has been clarified that Class IA Phosphatidylinositol 3-kinases (PI3K), whose catalytic subunit p110α is encoded by the PIK3CA gene, are involved in signal transduction that regulates cell cycle, cell growth, and metabolism and, if disturbed, induces carcinogenic effects. Although PI3K is associated with pro-inflammatory cyclooxygenase-2 (COX-2) expression and signaling, and COX-2 is among the best-studied targets of aspirin, the mechanisms behind this clinically relevant phenomenon are still unclear. Indeed, there is further evidence that the protective, anti-carcinogenic effect of aspirin in this setting may be mediated in a COX-independent manner. However, until now the understanding of aspirin's prostaglandin-independent mode of action is poor. This review will provide an overview of the current literature on this topic and aims to analyze possible mechanisms and targets behind the aspirin sensitivity of PIK3CA-mutated cancers.

Ghrelin and Cancer: Examining the Roles of the Ghrelin Axis in Tumor Growth and Progression

Ghrelin, a hormone produced and secreted from the stomach, is prim arily known as an appetite stimulant. Recently, it has emerged as a potential regulator/biomarker of cancer progression. Inconsistent results on this subject make this body of literature difficult to interpret. Here, we attempt to identify commonalities in the relationships between ghrelin and various cancers, and summarize important considerations for future research. The main players in the ghrelin family axis are unacylated ghrelin (UAG), acylated ghrelin (AG), the enzyme ghrelin O-acyltransferase (GOAT), and the growth hormone secretagogue receptor (GHSR). GOAT is responsible for the acylation of ghrelin, after which ghrelin can bind to the functional ghrelin receptor GHSR-1a to initiate the activation cascade. Splice variants of ghrelin also exist, with the most prominent being In1-ghrelin. In this review, we focus primarily on the potential of In1-ghrelin as a biomarker for cancer progression, the unique characteristics of UAG and AG, the importance of the two known receptor variants GHSR-1a and 1b, as well as the possible mechanisms through which the ghrelin axis acts. Further understanding of the role of the ghrelin axis in tumor cell proliferation could lead to the development of novel therapeutic approaches for various cancers.

Acetylsalicylic acid suppression of the PI3K pathway as a novel medical therapy for head and neck lymphatic malformations

OBJECTIVES

Head and neck lymphatic malformations (HNLM) are caused by gain-of-function somatic mutations in PIK3CA. Acetylsalicylic acid (ASA/aspirin) is thought to limit growth in PIK3CA-mutated neoplasms through PI3K pathway suppression. We sought to determine if ASA could be beneficial for HNLM.

METHODS

Retrospective case series of patients (0-18 years) offered ASA (3-5 mg/kg/day) for HNLM treatment (2010-2018). Clinical and treatment characteristics, patient-reported symptom improvement, medication tolerance, compliance, and complications were recorded. Treatment response was determined by change in patient/caregiver-reported symptoms, or HNLM size [complete (resolved), partial (decreased), or stable].

RESULTS

Fifty-three patients were offered ASA, 23 (43%) accepted (median age 10 years, IQR 6-14). Compared to patients who declined, patients receiving ASA were more likely to have extensive malformations: ex-utero intrapartum treatment procedure, bilateral malformations, oral cavity location, ≥2 invasive treatments, or tracheotomy (p < 0.05). All patients with tissue available had PIK3CA mutations (13/23). Treatment indications included oral pain/blebs (12, 52%), recurrent pain/swelling (6, 26%), or sudden/persistent swelling (5, 22%). Treatment plan was commonly one 81 mg tablet daily (19, 83%) for 3-12 months (8, 42%). Therapeutic adherence was reported by 18 patients (78%). Symptoms improved in 18 patients [78%; decreased pain (9, 39%) and swelling (8, 35%)]. Treatment resulted in partial (14, 61%) or complete response (4, 17%). Three patients developed oral bleb bleeding, which resolved with medication discontinuation.

CONCLUSION

ASA seems to be a well-tolerated, low-risk medication for HNLM treatment. This pilot study suggests that it often improves symptoms and reduces HNLM size. Further prospective, randomized studies are warranted to comprehensively assess indications, safety, and efficacy.

LEVEL OF EVIDENCE

Level 4.

Integrative Bioinformatics Study of Tangeretin Potential Targets for Preventing Metastatic Breast Cancer

Agents that target metastasis are important to improve treatment efficacy in patients with breast cancer. Tangeretin, a citrus flavonoid, exhibits antimetastatic effects on breast cancer cells, but its molecular mechanism remains unclear. Tangeretin targets were retrieved from PubChem, whereas metastatic breast cancer regulatory genes were downloaded from PubMed. In total, 58 genes were identified as potential therapeutic target genes of tangeretin (PTs). GO and KEGG pathway enrichment analyses of PTs were performed using WebGestalt (WEB-based Gene SeT AnaLysis Toolkit). The PPI network was analyzed using STRING-DB v11.0 and visualized by Cytoscape software. Hub genes were selected on the basis of the highest degree score as calculated by the CytoHubba plugin. Genetic alterations of the PTs were analyzed using cBioPortal. The prognostic values of the PTs were evaluated with the Kaplan-Meier plot. The expression of PTs across breast cancer samples was confirmed using GEPIA. The reliability of the PTs in metastatic breast cancer cells was validated using ONCOMINE. Molecular docking was performed to foresee the binding sites of tangeretin with PIK3Cα, MMP9, PTGS2, COX-2, and IKK. GO analysis showed that PTs participate in the biological process of stimulus response, are the cellular components of the nucleus and the membrane, and play molecular roles in enzyme regulation. KEGG pathway enrichment analysis revealed that PTs regulate the PI3K/Akt pathway. Genetic alterations for each target gene were MTOR (3%), NOTCH1 (4%), TP53 (42%), MMP9 (4%), NFKB1 (3%), PIK3CA (32%), PTGS2 (15%), and RELA (5%). The Kaplan-Meier plot showed that patients with low mRNA expression levels of MTOR, TP53, MMP9, NFKB1, PTGS2, and RELA and high expression of PIK3CA had a significantly better prognosis than their counterparts. Further validation of gene expression by using GEPIA revealed that the mRNA expression of MMP9 was significantly higher in breast cancer tissues than in normal tissues, whereas the mRNA expression of PTGS2 showed the opposite. Analysis with ONCOMINE demonstrated that the mRNA expression levels of MMP9 and NFKB1 were significantly higher in metastatic breast cancer cells than in normal tissues. The results of molecular docking analyses revealed the advantage of tangeretin as an inhibitor of PIK3CA, MMP9, PTGS2, and IKK. Tangeretin inhibits metastasis in breast cancer cells by targeting TP53, PTGS2, MMP9, and PIK3CA and regulating the PI3K/Akt signaling pathway. Further investigation is needed to validate the results of this study.

Aspirin Use and Mortality in Women With Ovarian Cancer: A Meta-Analysis

Background

Aspirin use has been suggested to reduce the incidence of ovarian cancer (OC) in women. However, previous studies regarding the association between aspirin use and mortality in women with OC showed inconsistent results. We aimed to evaluate the association between aspirin use and mortality in women with OC in a meta-analysis.

Methods

Relevant cohort studies were obtained via search of PubMed, Cochrane’s Library, and Embase databases from inception to May 3, 2020. A random-effect model, which incorporates the potential heterogeneity among the included studies, was used to pool the results. Predefined stratified analyses were applied to evaluate the potential study characteristics on the outcome, including the timing of aspirin use, dose of aspirin, age of the women, and the clinical stages of the cancer. Sensitivity analysis by omitting one study at a time was used to assess the stability of the results.

Results

Six cohort studies including 17,981 women with OC were included. Pooled results showed that aspirin use had no statistically significant association with mortality in these patients (adjusted risk ratio [RR]: 0.85, 95% confidence interval [CI]: 0.70 to 1.02, p = 0.08; I² = 69%). The results were similar for OC-specific mortality (RR: 0.85, 95% CI: 0.57 to 1.26, p = 0.41) and all-cause mortality (RR: 0.78, 95% CI: 0.55 to 1.11, p = 0.17). Stratified analyses suggested that aspirin use had no statistically significant association with mortality risk in OC regardless the timing of aspirin use, dose of aspirin, age of the women, or the clinical stages of the cancer. Funnel plots suggested potential risk of publication bias (p all > 0.05). However, further “trim-and-fill” analysis incorporating hypothesized unpolished studies to achieve symmetrical funnel plots showed similar results of the meta-analysis (RR: 0.91, 95% CI: 0.74 to 1.13, p = 0.39).

Conclusions

Current evidence from observational studies indicated that aspirin use had no statistically significant association with mortality in women with OC.

The Role of Eicosanoids in Gynecological Malignancies

Eicosanoids, bio-active lipid molecules, evoke a multitude of biological effects that directly affect cancer cells and indirectly affect tumor microenvironment. An emerging role has been shown for eicosanoids in the pathogenesis of gynecological malignancies which include cancers of the vulva, vagina, cervix, uterine, and ovary. Eicosanoid biosynthesis pathways start at the metabolism of phospholipids by phospholipase A2 then proceeding to one of three pathways: the cyclooxygenase (COX), lipoxygenase (LOX), or P450 epoxygenase pathways. The most studied eicosanoid pathways include COX and LOX; however, more evidence is appearing to support further study of the P450 epoxygenase pathway in gynecologic cancers. In this review, we present the current knowledge of the role of COX, LOX and P450 pathways in the pathogenesis of gynecologic malignancies. Vulvar and vaginal cancer, the rarest subtypes, there is association of COX-2 expression with poor disease specific survival in vulvar cancer and, in vaginal cancer, COX-2 expression has been found to play a role in mucosal inflammation leading to disease susceptibility and transmission. Cervical cancer is associated with COX-2 levels 7.4 times higher than in healthy tissues. Additionally, HPV elevates COX-2 levels through the EGFR pathway and HIV promotes elevated COX-2 levels in cervical tissue as well as increases PGE2 levels eliciting inflammation and progression of cancer. Evidence supports significant roles for both the LOX and COX pathways in uterine cancer. In endometrial cancer, there is increased expression of 5-LOX which is associated with adverse outcomes. Prostanoids in the COX pathway PGE2 and PGF2α have been shown to play a significant role in uterine cancer including alteration of proliferation, adhesion, migration, invasion, angiogenesis, and the inflammatory microenvironment. The most studied gynecological malignancy in regard to the potential role of eicosanoids in tumorigenesis is ovarian cancer in which all three pathways have shown to be associated or play a role in ovarian tumorigenesis directly on the tumor cell or through modulation of the tumor microenvironment. By identifying the gaps in knowledge, additional pathways and targets could be identified in order to obtain a better understanding of eicosanoid signaling in gynecological malignancies and identify potential new therapeutic approaches.

COX-2-PGE2-EPs in gynecological cancers

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors (COXibs) inhibit the progression of endometrial cancer, ovarian cancer and cervical cancer. However, concerning the adverse effects of NSAIDs and COXibs, it is still urgent and necessary to explore novel and specific anti-inflammation targets for potential chemoprevention. The signaling of cyclooxygenase 2-prostaglandin E₂-prostaglandin E₂ receptors (COX-2-PGE₂-EPs) is the central inflammatory pathway involved in the gynecological carcinogenesis.

METHODS

Literature searches were performed to the function of COX-2-PGE₂-EPs in gynecological malignancies.

RESULTS

This review provides an overview of the current knowledge of COX-2-PGE₂-EPs signaling in endometrial cancer, ovarian cancer and cervical cancer. Many studies demonstrated the upregulated expression of the whole signaling pathway in gynecological malignancies and some focused on the function of COX-2 and cAMP-linked EP2/EP4 and EP3 signaling pathway in gynecological cancer. By contrast, roles of EP1 and the exact pathological mechanisms have not been completely clarified. The studies concerning EP receptors in gynecological cancers highlight the potential advantage of combining COX enzyme inhibitors with EP receptor antagonists as therapeutic agents in gynecological cancers.

CONCLUSION

EPs represent promising anti-inflammation biomarkers for gynecological cancer and may be novel treatment targets in the near future.

Personalized Medicine-Current and Emerging Predictive and Prognostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide and is heterogeneous both morphologically and molecularly. In an era of personalized medicine, the greatest challenge is to predict individual response to therapy and distinguish patients likely to be cured with surgical resection of tumors and systemic therapy from those resistant or non-responsive to treatment. Patients would avoid futile treatments, including clinical trial regimes and ultimately this would prevent under- and over-treatment and reduce unnecessary adverse side effects. In this review, the potential of specific biomarkers will be explored to address two key questions—1) Can the prognosis of patients that will fare well or poorly be determined beyond currently recognized prognostic indicators? and 2) Can an individual patient’s response to therapy be predicted and those who will most likely benefit from treatment/s be identified? Identifying and validating key prognostic and predictive biomarkers and an understanding of the underlying mechanisms of drug resistance and toxicity in CRC are important steps in order to personalize treatment. This review addresses recent data on biological prognostic and predictive biomarkers in CRC. In addition, patient cohorts most likely to benefit from currently available systemic treatments and/or targeted therapies are discussed in this review.

NSAID therapy for PIK3CA-Altered colorectal, breast, and head and neck cancer

Epidemiologic evidence indicates that regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) provides a protective effect against the development of colorectal, breast, and head and neck cancers. Genomic characterization of these cancers has lent considerable insight into the subpopulations of cancer patients who are most likely to benefit from NSAID therapy. The PIK3CA gene encodes the catalytic subunit of phosphatidylinositol 3-kinase (PI3K) and is among the most frequently mutated genes in solid tumor malignancies. Cancer-associated mutations in PIK3CA promote signaling via the PI3K pathway and stimulate tumor cell growth. In addition, activation of the PI3K pathway leads to induction of cyclooxygenase-2 (COX-2) enzyme and production of immunosuppressive prostaglandin E2 (PGE2). Notably, in both colorectal cancer and head and neck cancer the subpopulation of patients that benefit from NSAID use is restricted to those whose tumors exhibit PIK3CA genomic alterations. Preclinical studies, particularly in models of head and neck cancer, support the hypothesis that the chemopreventive impact of NSAIDs may be due, in part, to inhibition of COX-2 and reduction of PGE2 levels in the tumor microenvironment.

The role of aspirin in the prevention of ovarian, endometrial and cervical cancers

Drug repurposing is the application of an existing licenced drug for a new indication and potentially provides a faster and cheaper approach to developing new anti-cancer agents. Gynaecological cancers contribute significantly to the global cancer burden, highlighting the need for low cost, widely accessible therapies. A large body of evidence supports the role of aspirin as an anti-cancer agent, and a number of randomized trials are currently underway aiming to assess the potential benefit of aspirin in the treatment of cancer. This review summarizes the evidence underpinning aspirin use for the prevention of the development and recurrence of gynaecological cancers (ovarian, endometrial and cervical) and potential mechanisms of action.

Cyclooxygenase 2 Promotes Proliferation and Invasion in Ovarian Cancer Cells via the PGE2/NF-κB Pathway

Ovarian cancer is the leading cause of death among gynecological malignancies. Cyclooxygenase 2 is widely expressed in various cancer cells and participates in the occurrence and development of tumors by regulating a variety of downstream signaling pathways. However, the function and molecular mechanisms of cyclooxygenase 2 remain unclear in ovarian cancer. Here, we demonstrated that cyclooxygenase 2 was highly expressed in ovarian cancer and the expression level was highly correlated with ovarian tumor grades. Further, ovarian cancer cells with high expression of cyclooxygenase 2 exhibit enhanced proliferation and invasion abilities. Specifically, cyclooxygenase 2 promoted the release of prostaglandin E2 upregulated the phosphorylation levels of phospho-nuclear factor-kappa B p65. Celecoxib, AH6809, and BAY11-7082 all can inhibit the promoting effect of cyclooxygenase 2 on SKOV3 and OVCAR3 cell proliferation and invasion. Besides, celecoxib inhibited SKOV3 cell growth in the xenograft tumor model. These data suggest that high expression of cyclooxygenase 2 promotes the proliferation and invasion of ovarian cancer cells through the prostaglandin E2/nuclear factor-kappa B signaling pathway. Cyclooxygenase 2 may be a potential therapeutic target for the treatment of ovarian cancer.

Engineered 3D Model of Cancer Stem Cell Enrichment and Chemoresistance

Intraperitoneal dissemination of ovarian cancers is preceded by the development of chemoresistant tumors with malignant ascites. Despite the high levels of chemoresistance and relapse observed in ovarian cancers, there are no in vitro models to understand the development of chemoresistance in situ. Method: We describe a highly integrated approach to establish an in vitro model of chemoresistance and stemness in ovarian cancer, using the 3D hanging drop spheroid platform. The model was established by serially passaging non-adherent spheroids. At each passage, the effectiveness of the model was evaluated via measures of proliferation, response to treatment with cisplatin and a novel ALDH1A inhibitor. Concomitantly, the expression and tumor initiating capacity of cancer stem-like cells (CSCs) was analyzed. RNA-seq was used to establish gene signatures associated with the evolution of tumorigenicity, and chemoresistance. Lastly, a mathematical model was developed to predict the emergence of CSCs during serial passaging of ovarian cancer spheroids. Results: Our serial passage model demonstrated increased cellular proliferation, enriched CSCs, and emergence of a platinum resistant phenotype. In vivo tumor xenograft assays indicated that later passage spheroids were significantly more tumorigenic with higher CSCs, compared to early passage spheroids. RNA-seq revealed several gene signatures supporting the emergence of CSCs, chemoresistance, and malignant phenotypes, with links to poor clinical prognosis. Our mathematical model predicted the emergence of CSC populations within serially passaged spheroids, concurring with experimentally observed data. Conclusion: Our integrated approach illustrates the utility of the serial passage spheroid model for examining the emergence and development of chemoresistance in ovarian cancer in a controllable and reproducible format.

Isoform-Specific Role of Akt in Oral Squamous Cell Carcinoma

Protein kinase B (Akt) plays a very significant role in various cancers including oral cancer. However, it has three isoforms (Akt1, Akt2, and Akt3) and they perform distinct functions and even play contrasting roles in different cancers. Therefore, it becomes essential to evaluate the isoform-specific role of Akt in oral cancer. In the present study, an attempt has been made to elucidate the isoform-specific role of Akt in oral cancer. The immunohistochemical analysis of oral cancer tissues showed an overexpression of Akt1 and 2 isoforms but not Akt3. Moreover, the dataset of "The Cancer Genome Atlas" for head and neck cancer has suggested the genetic alterations of Akt1 and 2 tend to be associated with the utmost poor clinical outcome in oral cancer. Further, treatment of oral cancer cells with tobacco and its components such as benzo(a)pyrene and nicotine caused increased mRNA levels of Akt1 and 2 isoforms and also enhanced the aggressiveness of oral cancer cells in terms of proliferation, and clonogenic and migration potential. Finally, silencing of Akt1 and 2 isoforms caused decreased cell survival and induced cell cycle arrest at the G2/M phase. Akt1/2 silencing also reduced tobacco-induced aggressiveness by decreasing the clonogenic and migration potential of oral cancer cells. Moreover, silencing of Akt1 and 2 isoforms was found to decrease the expression of proteins regulating cancer cell survival and proliferation such as cyclooxygenase-2, B-cell lymphoma 2 (Bcl-2), cyclin D1, and survivin. Thus, the important role of Akt1 and 2 isoforms have been elucidated in oral cancer with in-depth mechanistic analysis.

Cyclooxygenase Inhibitors in Epithelial Ovarian Cancer Treatment

Epithelial ovarian cancer (EOC) is the fifth most common cause of cancer mortality among women. At present, EOC is treated with one or in a combination of treatments, commonly debulking surgery, combining a platinum-based and a taxane-based therapy; however, the patients have a risk of injury to the bowel, bladder, ureter, and vessels during surgery and many of them suffer from severe adverse effects caused by chemotherapy. Pharmaceutical inhibition of cyclooxygenase (COX) might be an important therapeutic tool in cancer treatment, as COX contributes to cancer progression by upregulating the levels of downstream metabolites. In this review article, we have discussed the role of COX in cancer progression and the therapeutic use of COX inhibitors in the treatment of EOC with subsequent clinical studies and future management. Usually, gonadotropins can promote prostaglandin E2 production in EOC cells via COX-1 and -2 upregulations through the PI3K/AKT signaling pathway. Several reports have shown that treatment of EOC cells with COX-1- and COX-2-specific inhibitors exhibits a therapeutic effect on EOC both in vitro and in vivo. However, more clinical investigations are needed to develop therapeutic COX inhibitors for the prevention and treatment of EOC without adverse effects.

Beyond a chemopreventive reagent, aspirin is a master regulator of the hallmarks of cancer

PURPOSE

Aspirin, one of the most commonly used nonsteroidal anti-inflammatory drugs (NAIDS), not only shows cancer chemoprevention effects but also improves cancer therapeutic effects when combined with other therapies. Studies that focus on aspirin regulation of the hallmarks of cancer and the associated molecular mechanisms facilitate a more thorough understanding of aspirin in mediating chemoprevention and may supply additional information for the development of novel cancer therapeutic agents.

METHODS

The relevant literatures from PubMed have been reviewed in this article.

RESULTS

Current studies have revealed that aspirin regulates almost all the hallmarks of cancer. Within tumor tissue, aspirin suppresses the bioactivities of cancer cells themselves and deteriorates the tumor microenvironment that supports cancer progression. In addition to tumor tissues, blocking of platelet activation also contributes to the ability of aspirin to inhibit cancer progression. In terms of the molecular mechanism, aspirin targets oncogenes and cancer-related signaling pathways and activates certain tumor suppressors.

CONCLUSION

Beyond a chemopreventive agent, aspirin is a master regulator of the hallmarks of cancer.

CP‑31398 attenuates endometrial cancer cell invasion, metastasis and resistance to apoptosis by downregulating MDM2 expression

Endometrial cancer (EC) is one of the most common malignancies of the female reproductive system, and metastasis is a major cause of mortality. In this study, we aimed to explore the role of CP-31398 in the migration, invasion and apoptosis of EC cells by its regulation of the expression of the murine double minute 2 (MDM2) gene. For this purpose, EC tissues and adjacent normal tissues were collected, and the positive expression rate of MDM2 in these tissues was assessed. Subsequently, the cellular 50% inhibitory concentration (IC50) of CP-31398 was measured. The EC RL95-2 and KLE cell lines had a higher MDM2 expression and were thus selected for use in subsequent experiments. The EC cells were then treated with CP-31398 (2 µg/ml), and were transfected with siRNA against MDM2 or an MDM2 overexpression plasmid in order to examine the effects of CP-31398 and MDM2 on EC cell activities. The expression of p53, p21, Bad, Bax, B-cell lymphoma-2 (Bcl-2), cytochrome c (Cyt-c), caspase-3, Cox-2, matrix metalloproteinase (MMP)-2 and MMP-9 was measured to further confirm the effects of CP-31398 on cell migration, invasion and apoptosis. Our results indicated that MDM2 was highly expressed in EC tissues. Notably, EC cell viability decreased with the increasing concentrations of CP-31398. The EC cells treated with CP-31398 or siRNA against MDM2 exhibited an increased apoptosis and a suppressed migration and invasion, corresponding to an increased expression of p53, p21, Bad, Bax, Cyt-c and caspase-3, as well as to a decreased expression of Bcl-2, Cox-2, MMP-2 and MMP-9. Moreover, treatment with CP-31398 and siRNA against MDM2 further enhanced these effects. Taken together, the findings of this study indicate that the CP-31398-mediated downregulation of MDM2 may suppress EC progression via its inhibitory role in EC cell migration, invasion and resistance to apoptosis. Therefore, treatment with CP-31398 may prove to be possible therapeutic strategy for EC.

Nobiletin (NOB) suppresses autophagic degradation via over-expressing AKT pathway and enhances apoptosis in multidrug-resistant SKOV3/TAX ovarian cancer cells

Chemotherapy could be used as an effective therapeutic treatment for ovarian cancer and subsequent peritoneal metastasis. However, the occurrence of drug resistance reduced the treatment effect originated from cancer chemotherapy. Accumulating evidences indicated the significant role of autophagy in tumor cell resistance to chemotherapy. Thus, inhibition of autophagy using natural compounds could be a promising candidate to overcome multidrug resistance in human ovarian cancer cells. Nobiletin (NOB), a polymethoxyflavonoid found in citrus fruits such as Citrus depressa and Citrus reticulate, exhibits a number of bioactivities. In the present study, NOB selectively suppressed the growth and proliferation of human SKOV3/TAX cells, inducing G0/G1 phase arrest and reducing G2/M phase, along with the increase of p53 and p21. In addition, NOB induced significant apoptosis in SKOV3/TAX cells through the intrinsic apoptosis pathway, as evidenced by the up-regulation of cleaved Caspase-9/-3 and PARP. Further, NOB impaired the autophagic degradation in SKOV3/TAX cells, resulting in autophagic flux inhibition. Moreover, the impaired autophagic flux enhanced NOB-induced apoptosis in SKOV3/TAX cells. Importantly, AKT signaling was activated by NOB, which was involved in autophagic degradation and apoptotic cell death. In conclusion, the findings here supplied the illustration that NOB could overcome multidrug resistance in human ovarian cancer cells through AKT-regulated suppression of autophagic degradation.

Aspirin acts in esophageal cancer: a brief review

Improved survival in esophageal cancer patients with regular aspirin use have been reported. However, with conflicting experimental results existed, an explicit definition on the role of aspirin as an adjuvant chemotherapy of esophageal cancer remains unestablished. We have summarized the current epidemiologic trials evidence over antitumor effect of aspirin in esophageal cancer in the past decades, and most of the clinical data supports that long-term regular aspirin use could reduce the mortality and improve the survival in patients with esophageal cancer. Although most of the clinical trials of aspirin on esophageal cancer are designed focusing on the prediagnosed chemo-preventive role, other than the post-diagnosed therapeutic role, it has been suggested by some studies that aspirin use as an adjuvant treatment after the standard surgery in esophageal cancer may benefit more. In the meanwhile, post diagnosed aspirin use may lead to lower risk of hemorrhage and other side effects of NSAIDs. Potential involved molecular pathways in the antitumor activities of aspirin are under studied worldwide for years and the possible mechanisms so far are reviewed in this article as cyclooxygenase (COX)-dependent pathways and COX-independent pathways, involving anti-inflammatory activity, apoptosis, platelet deactivation, PIK3CA mutation specificity and heparanase-related microenvironment changes of tumor cells. NOSH-aspirin has been developed as a succedaneum of aspirin with a wider application ranges by reducing the risk of hemorrhage in aspirin users. Further clinical and basic studies are suggested focusing on whether regular aspirin use as an adjuvant treatment prolongs survival and prevents recurrence in patients with esophageal cancer.

Combination of COX-2 expression and PIK3CA mutation as prognostic and predictive markers for celecoxib treatment in breast cancer

COX-2 expression level and prognostic value are still a matter of debate in breast cancer (BC). We addressed these points in the context of PIK3CA mutational status. Based on an interesting study of aspirin efficacy in colorectal cancer, we hypothesized that celecoxib antitumoral activity may be restricted to PIK3CA mutated BC.

COX-2 mRNA expression was analyzed in 446 BC samples and in 61 BC patient-derived xenografts (PDX) using quantitative RT-PCR. The prognostic impact of COX-2 expression level was assessed independently and according to PIK3CA mutational status in our cohort and in a validation set of 817 BC. The antitumoral activity of celecoxib was tested in two triple-negative (TN) PDX with a PIK3CA wild-type (wt) or mutated genotype.

COX-2 mRNA was overexpressed in 2% of BC and significantly associated with TN subtype. Metastasis-free survival (MFS) was significantly better in patients with high COX-2 expression level, the prognosis of whom was similar to patients with PIK3CA mutations. TCGA validation cohort confirmed that patients with low COX-2 expression PIK3CA wt tumors had the worse disease-free survival (DFS) compared to all other subgroups. Celecoxib had a significant antitumoral effect in PIK3CA mutated PDX only. Celecoxib antitumoral activity involved S6 ribosomal protein and AKT phosphorylation.

Low expression of COX-2 has a significant negative impact on the MFS/DFS of BC patients. Antitumoral effect of celecoxib is restricted to PIK3CA mutated PDX. These results suggest that PIK3CA mutation may be a new predictive biomarker for celecoxib efficacy.

The effect of celecoxib on tumor growth in ovarian cancer cells and a genetically engineered mouse model of serous ovarian cancer

Our objective was to evaluate the effect of the COX-2 inhibitor, celecoxib, on (1) proliferation and apoptosis in human ovarian cancer cell lines and primary cultures of ovarian cancer cells, and (2) inhibition of tumor growth in a genetically engineered mouse model of serous ovarian cancer under obese and non-obese conditions. Celecoxib inhibited cell proliferation in three ovarian cancer cell lines and five primary cultures of human ovarian cancer after 72 hours of exposure. Treatment with celecoxib resulted in G1 cell cycle arrest, induction of apoptosis, inhibition of cellular adhesion and invasion and reduction of expression of hTERT mRNA and COX-2 protein in all of the ovarian cancer cell lines. In the KpB mice fed a high fat diet (obese) and treated with celecoxib, tumor weight decreased by 66% when compared with control animals. Among KpB mice fed a low fat diet (non-obese), tumor weight decreased by 46% after treatment with celecoxib. In the ovarian tumors from obese and non-obese KpB mice, treatment with celecoxib as compared to control resulted in decreased proliferation, increased apoptosis and reduced COX-2 and MMP9 protein expression, as assessed by immunohistochemistry. Celecoxib strongly decreased the serum level of VEGF and blood vessel density in the tumors from the KpB ovarian cancer mouse model under obese and non-obese conditions. This work suggests that celecoxib may be a novel chemotherapeutic agent for ovarian cancer prevention and treatment and be potentially beneficial in both obese and non-obese women.

FoxM1 and β-catenin predicts aggressiveness in Middle Eastern ovarian cancer and their co-targeting impairs the growth of ovarian cancer cells

Epithelial ovarian cancer (EOC) is a highly lethal disease with poor prognosis especially in advanced stage tumor. Emerging evidence has reported that aberrant upregulation of FoxM1 and β-catenin are closely associated with aggressiveness of human cancer. However, interplay between these factors in the aggressiveness of EOC is not fully illustrated. In this study, we show that FoxM1 is frequently increased in Middle Eastern EOC and associated with high proliferative index (p = 0.0007) and high grade tumor (p = 0.0024). Interestingly, FoxM1 is significantly associated with elevated nuclear β-catenin and the concomitant increase of FoxM1 and β-catenin is associated with advanced stage of EOC by immunohistochemical analysis of 261 samples of Saudi patients with EOC. Functional analysis showed that β-catenin is a direct transcriptional target of FoxM1 in EOC cell lines. FoxM1 inhibition either by specific inhibitor, thiostrepton or siRNA suppressed β-catenin expression, whereas overexpression of FoxM1 increased nuclear β-catenin expression. We identified two FoxM1 binding sites in the β-catenin promoter that specifically bound to FoxM1 protein. Down-regulation of FoxM1 using thiostrepton induced apoptosis and inhibited cell migration/invasion in EOC cells. Moreover, co-inhibition of FoxM1 by thiostrepton and β-catenin by FH535 significantly and synergistically inhibited EOC cell growth in vitro and in vivo. Collectively, our findings confer that co-targeting FoxM1/β-catenin signaling cascade may be a promising molecular therapeutic choice in advanced EOC.

AMPK-mediated up-regulation of mTORC2 and MCL-1 compromises the anti-cancer effects of aspirin

AMP-activated protein kinase (AMPK) is an important energy sensor that may inhibit cell proliferation or promote cell survival during stresses. Besides cyclooxygenase, AMPK is another target of the nonsteroid anti-inflammatory agent aspirin. Preclinical and clinical investigations demonstrate that aspirin can inhibit several types of cancer such as colorectal adenomas and hepatocellular carcinoma (HCC). However, little is known about the cellular response to aspirin that may lead to aspirin resistance. Here, we show that aspirin induces the expression of MCL-1 in HepG2 and SW480 cells through AMPK-mTOR-Akt/ERK axis. Treatment of HepG2 and SW480 cells with aspirin leads to increased MCL-1 expression, Akt and ERK1/2 phosphorylation. Inhibition of Akt/MEK abrogates the induction of MCL-1 by aspirin. Aspirin activates AMPK, which in turn up-regulates mTORC2 activity, Akt, ERK1/2 phosphorylation and MCL-1 expression. MCL-1 knockdown sensitizes cancer cells to aspirin-induced apoptosis. Combination of aspirin and AMPK, Akt or MEK inhibitor results in more significant inhibition of cell proliferation and induction of apoptosis than single agent. Moreover, sorafenib blocks aspirin-induced MCL-1 up-regulation. Combination of aspirin and sorafenib leads to much more cell death and less cell proliferation than each drug alone. Treatment of HCC and colon cancer xenografts with both aspirin and sorafenib results in more significant tumor suppression than single agent. These data demonstrate that AMPK-mediated up-regulation of mTORC2 and MCL-1 may compromise the anticancer effects of aspirin. Combination of aspirin and sorafenib may be an effective regimen to treat HCC and colon cancer.

COX-2 expression in ovarian cancer: an updated meta-analysis

The prognostic role of COX-2 expression in ovarian cancer patients has been studied for years, while results remain controversial. Thus we performed a meta-analysis to evaluate the prognostic impact of COX-2 expression on survival of ovarian cancer patients. The databases PubMed, Embase and CNKI were searched. Summary hazard ratio (HR) and 95% confidence intervals (CIs) were calculated to analyze the correlations between COX-2 expression and overall survival (OS), and disease-free survival (DFS). A total of 1,867 patients from 18 studies were enrolled in the final analysis. The results showed that patients with higher COX-2 expression had a poor OS (HR: 1.48; 95% CI: 1.19-1.85) and DFS (HR: 1.81, 95% CI: 1.28-2.55). Subgroup analysis showed that there had significant associations between COX-2 expression and survival rate in most of the subgroups. Furthermore, there were significant associations between COX-2 expression and several clinical parameters such as FIGO stage, histological type and age. These results showed the patients with higher COX-2 expression had a significantly poorer survival rate, COX-2 expression had the potential to be a prognostic marker of ovarian cancer.

The role of dietary polyphenols in the moderation of the inflammatory response in early stage colorectal cancer

Current focus in colorectal cancer (CRC) management is on reducing overall mortality by increasing the number of early-stage cancers diagnosed and treated with curative intent. Despite the success of screening programs in down-staging CRC, interval cancer rates are substantial and other strategies are desirable. Sporadic CRC is largely associated with lifestyle factors including diet. Polyphenols are phytochemicals ingested as part of a normal diet, which are abundant in plant foods including fruits/berries and vegetables. These may exert their anti-carcinogenic effects via the modulation of inflammatory pathways. Key signal transduction pathways are fundamental to the association of inflammation and disease progression including those mediated by NF-κB and STAT, PI3K and COX. Our aim was to examine the evidence for the effect of dietary polyphenols intake on tumor and host inflammatory responses to determine if polyphenols may be effective as part of a dietary intervention. There is good epidemiological evidence of a reduction in CRC risk from case-control and cohort studies assessing polyphenol intake. It would be premature to suggest a major public health intervention to promote their consumption; however, dietary change is safe and feasible, emphasizing the need for further investigation of polyphenols and CRC risk.

Genetic and epigenetic markers in colorectal cancer screening: recent advances

INTRODUCTION

Colorectal cancer (CRC) is a heterogenous disease which develops from benign intraepithelial lesions known as adenomas to malignant carcinomas. Acquired alterations in Wnt signaling, TGFβ, MAPK pathway genes and clonal propagation of altered cells are responsible for this transformation. Detection of adenomas or early stage cancer in asymptomatic patients and better prognostic and predictive markers is important for improving the clinical management of CRC. Area covered: In this review, the authors have evaluated the potential of genetic and epigenetic alterations as markers for early detection, prognosis and therapeutic predictive potential in the context of CRC. We have discussed molecular heterogeneity present in CRC and its correlation to prognosis and response to therapy. Expert commentary: Molecular marker based CRC screening methods still fail to gain trust of clinicians. Invasive screening methods, molecular heterogeneity, chemoresistance and low quality test samples are some key challenges which need to be addressed in the present context. New sequencing technologies and integrated omics data analysis of individual or population cohort results in GWAS. MPE studies following a GWAS could be future line of research to establish accurate correlations between CRC and its risk factors. This strategy would identify most reliable biomarkers for CRC screening and management.

Evaluation of PTGS2 Expression, PIK3CA Mutation, Aspirin Use and Colon Cancer Survival in a Population-Based Cohort Study

OBJECTIVES

The association between aspirin use and improved survival after colorectal cancer diagnosis may be more pronounced in tumors that have PIK3CA mutations or high PTGS2 expression. However, the evidence of a difference in association by biomarker status lacks consistency. In this population-based colon cancer cohort study the interaction between these biomarkers, aspirin use, and survival was assessed.

METHODS

The cohort consisted of 740 stage II and III colon cancer patients diagnosed between 2004 and 2008. Aspirin use was determined through clinical note review. Tissue blocks were retrieved to determine immunohistochemical assessment of PTGS2 expression and the presence of PIK3CA mutations. Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for colorectal cancer-specific and overall survival.

RESULTS

In this cohort aspirin use was associated with a 31% improvement in cancer-specific survival compared to non-use (adjusted HR=0.69, 95% CI 0.47-0.98). This effect was more pronounced in tumors with high PTGS2 expression (PTGS2-high adjusted HR=0.55, 95% CI 0.32-0.96) compared to those with low PTGS2 expression (PTGS2-low adjusted HR=1.19, 95% CI 0.68-2.07, P for interaction=0.09). The aspirin by PTGS2 interaction was significant for overall survival (PTGS2-high adjusted HR=0.64, 95% CI 0.42-0.98 vs. PTGS2-low adjusted HR=1.28, 95% CI 0.80-2.03, P for interaction=0.04). However, no interaction was observed between aspirin use and PIK3CA mutation status for colorectal cancer-specific or overall survival.

CONCLUSIONS

Aspirin use was associated with improved survival outcomes in this population-based cohort of colon cancer patients. This association differed according to PTGS2 expression but not PIK3CA mutation status. Limiting adjuvant aspirin trials to PIK3CA-mutant colorectal cancer may be too restrictive.

Cancer cells increase endothelial cell tube formation and survival by activating the PI3K/Akt signalling pathway

Background

Angiogenesis is a hallmark of cancer and plays a critical role in lung cancer progression, which involves interactions between cancer cells, endothelial cells and the surrounding microenvironment. However, the gene expression profiles and the changes in the biological phenotype of vascular endothelial cells after interactions with lung cancer cells remain unclear.

Methods

An indirect transwell co-culture system was used to survey the interaction between human umbilical vein endothelial cells (HUVECs) and human lung adenocarcinoma CL1-5 cells, as well as to investigate the morphological and molecular changes of HUVECs. The differentially expressed genes (DEGs) in HUVECs after co-culture with cancer cells were identified by microarray. Moreover, a publicly available microarray dataset of 293 non-small-cell lung cancer (NSCLC) patients was employed to evaluate the prognostic power of the gene signatures derived from HUVECs.

Results

The interaction between HUVECs and lung cancer cells changes the morphology of HUVECs, causing them to have a mesenchymal-like morphology and alter their cytoskeleton organization. Furthermore, after co-culture with lung cancer cells, HUVECs showed increased cell motility and microvessel tube formation ability and a decreased apoptotic percentage. Transcriptomic profiling of HUVECs revealed that many survival-, apoptosis- and angiogenesis-related genes were differentially expressed after interactions with lung cancer cells. Further investigations showed that the PI3K/Akt signalling pathway and COX-2 are involved in endothelial tube formation under the stimulation of lung cancer cells. Moreover, Rac-1 activation might promote endothelial cell motility through the increased formation of lamellipodia and filopodia. The inhibitors of PI3K and COX-2 could reverse the increased tube formation and induce the apoptosis of HUVECs. In addition, the gene signatures derived from the DEGs in HUVECs could predict overall survival and disease-free survival in NSCLC patients and serve as an independent prognostic factor.

Conclusions

In this study, we found that cancer cells can promote endothelial cell tube formation and survival, at least in part, through the PI3K/Akt signalling pathway and thus change the microenvironment to benefit tumour growth. The gene signatures from HUVECs are associated with the clinical outcome of NSCLC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0495-3) contains supplementary material, which is available to authorized users.

Aspirin enhances the cytotoxic activity of bortezomib against myeloma cells via suppression of Bcl-2, survivin and phosphorylation of AKT

In our previous study, it was found that aspirin (ASA) exerted antimyeloma actions in vivo and in vitro. The resistance to bortezomib (BTZ) in multiple myeloma (MM) is partly due to AKT activation and the upregulation of survivin induced by BTZ, which are the targets of ASA in gastric and ovarian cancer, respectively. Thus, the present study investigated the interaction between ASA and BTZ in MM and further clarified the underlying mechanisms. MM1.S and RPMI-8226 cell lines harboring the N- and K-Ras mutations, respectively, were treated with 2.5 mM ASA, 10 nM BTZ and ASA+BTZ for different durations. The proliferation and apoptosis of the cells were determined, and the underlying mechanisms governing the interaction of ASA and BTZ were examined in the MM cells. Treatment with ASA+BTZ caused higher rates of proliferative inhibition and apoptosis in the MM1.S and RPMI-8226 cells in time-dependent manner, compared with either agent alone. A drug interaction assay revealed the additive effect of ASA and BTZ on the myeloma cells. ASA alone inhibited the levels of phosphorylated AKT (p-AKT) and survivin, whereas BTZ alone augmented the levels of p-AKT and survivin. Of note, ASA markedly decreased the upregulation of p-AKT and survivin induced by BTZ. Treatment with ASA+BTZ significantly suppressed the level of Bcl-2, compared with either agent alone. ASA may potentiate the antimyeloma activity of BTZ against myeloma cells via suppression of AKT phosphorylation, survivin and Bcl-2, indicating the potential of ASA+BTZ in treating MM, particularly for cases of BTZ-refractory/relapsed MM.

Inhibition of cAMP-Dependent PKA Activates β2-Adrenergic Receptor Stimulation of Cytosolic Phospholipase A2 via Raf-1/MEK/ERK and IP3-Dependent Ca2+ Signaling in Atrial Myocytes

We previously reported in atrial myocytes that inhibition of cAMP-dependent protein kinase (PKA) by laminin (LMN)-integrin signaling activates β2-adrenergic receptor (β2-AR) stimulation of cytosolic phospholipase A2 (cPLA2). The present study sought to determine the signaling mechanisms by which inhibition of PKA activates β2-AR stimulation of cPLA2. We therefore determined the effects of zinterol (0.1 μM; zint-β2-AR) to stimulate ICa,L in atrial myocytes in the absence (+PKA) and presence (-PKA) of the PKA inhibitor (1 μM) KT5720 and compared these results with atrial myocytes attached to laminin (+LMN). Inhibition of Raf-1 (10 μM GW5074), phospholipase C (PLC; 0.5 μM edelfosine), PKC (4 μM chelerythrine) or IP3 receptor (IP3R) signaling (2 μM 2-APB) significantly inhibited zint-β2-AR stimulation of ICa,L in-PKA but not +PKA myocytes. Western blots showed that zint-β2-AR stimulation increased ERK1/2 phosphorylation in-PKA compared to +PKA myocytes. Adenoviral (Adv) expression of dominant negative (dn) -PKCα, dn-Raf-1 or an IP3 affinity trap, each inhibited zint-β2-AR stimulation of ICa,L in + LMN myocytes compared to control +LMN myocytes infected with Adv-βgal. In +LMN myocytes, zint-β2-AR stimulation of ICa,L was enhanced by adenoviral overexpression of wild-type cPLA2 and inhibited by double dn-cPLA2S505A/S515A mutant compared to control +LMN myocytes infected with Adv-βgal. In-PKA myocytes depletion of intracellular Ca2+ stores by 5 μM thapsigargin failed to inhibit zint-β2-AR stimulation of ICa,L via cPLA2. However, disruption of caveolae formation by 10 mM methyl-β-cyclodextrin inhibited zint-β2-AR stimulation of ICa,L in-PKA myocytes significantly more than in +PKA myocytes. We conclude that inhibition of PKA removes inhibition of Raf-1 and thereby allows β2-AR stimulation to act via PKCα/Raf-1/MEK/ERK1/2 and IP3-mediated Ca2+ signaling to stimulate cPLA2 signaling within caveolae. These findings may be relevant to the remodeling of β-AR signaling in failing and/or aging heart, both of which exhibit decreases in adenylate cyclase activity.

Antitumor effect of antiplatelet agents in gastric cancer cells: an in vivo and in vitro study

BACKGROUND

The antitumor effects of antiplatelet agents in gastric cancer cells are not well known. In this study, the possibility of gastric cancer treatment with an antiplatelet agent, mainly aspirin, was examined both in vivo and in vitro.

METHODS

For in vivo experiments, tumor-bearing mice were treated by an antiplatelet antibody or aspirin, and the tumor growth was compared. For in vitro experiments, human gastric cancer cell lines were used to confirm the cancer cell growth and inhibition by reducing the platelet count or using aspirin. We also examined several cytokines by using an ELISA assay and conducted microRNA microarray analysis of MKN-45 tumor cells to determine the influence of platelets or aspirin.

RESULTS

In vivo experiments showed that tumor growth was inhibited by halving the circulating platelet count by using an antiplatelet antibody or peroral daily aspirin. In vitro experiments showed that the proliferation rates of gastric cancer cell lines were increased after coincubation with platelets and that the effect was inhibited by aspirin. Although the expression of interleukin-6, platelet-derived growth factor, transforming growth factor-β, and prostaglandin E2 did not correlate with tumor growth inhibition by aspirin, seven microRNAs showed altered expression in cancer cells in response to coincubation with platelets or addition of aspirin. Cells transfected with mir-4670-5p showed a significant increase in proliferation compared to negative control cells.

CONCLUSIONS

Our study showed that platelets increased the proliferation of gastric cancer cells and that this increase was inhibited by antiplatelet antibody or aspirin. Mir-4670-5p may play an important role in these responses.

PIK3CA Mutation, Aspirin Use after Diagnosis and Survival of Colorectal Cancer. A Systematic Review and Meta-analysis of Epidemiological Studies

AIMS

Regular aspirin use has been associated with inhibition of the whole spectrum of colorectal carcinogenesis, including prevention of metastases and reduced total mortality in colorectal cancer. Preclinical data show that aspirin down-regulates PI3 kinase (PI3K) signalling activity through cyclo-oxygenase-2 (COX-2) inhibition, leading to the hypothesis that the effect of aspirin might be different according to PIK3CA mutational status, but epidemiological studies have led to conflicting results. The aim of this study was to assess the relationship between PIK3CA status and the efficacy of regular use of aspirin after diagnosis on overall survival in colorectal cancer patients.

MATERIALS AND METHODS

We identified studies that compared post-diagnosis aspirin efficacy in colorectal cancer patients identified by PIK3CA status. Hazard ratios for overall survival were meta-analysed according to PIK3CA status by inverse variance weighting. A pooled test for treatment by PIK3CA status interaction was carried out by weighted linear meta-regression. All statistical tests were two-sided.

RESULTS

The overall effect of aspirin was not significant (summary risk estimate = 0.82; 95% confidence interval 0.63-1.08, P = 0.16; I(2) = 57%). In PIK3CA mutant disease (n = 588), aspirin use reduced total mortality by 29% (summary risk estimate = 0.71; 95% confidence interval 0.51-0.99, P = 0.04; I(2) = 0%), whereas in PIK3CA wild-type disease (n = 4001), aspirin use did not reduce overall mortality (summary risk estimate = 0.93; 95% confidence interval 0.61-1.40; P = 0.7; I(2) = 80%) (P interaction = 0.39). There was a beneficial trend for aspirin on cancer-specific survival in PI3KCA mutated subjects (summary risk estimate = 0.37, 95% confidence interval 0.11-1.32, P = 0.1), albeit with high heterogeneity (Q chi-squared = 3.41, P = 0.07, I(2) = 70.7%).

CONCLUSION

These findings suggest that the benefit of post-diagnosis aspirin treatment on overall mortality in colorectal cancer may be more marked in PIK3CA mutated tumours, although the low number of studies prevents definitive conclusions. Trials addressing this issue are warranted to assess the efficacy of aspirin in the adjuvant setting.

Repositioning of drugs for intervention in tumor progression and metastasis: Old drugs for new targets

The increasing unraveling of the molecular basis of cancer offers manifold novel options for intervention strategies. However, the discovery and development of new drugs for potential clinical applications is a tremendously time-consuming and costly process. Translating a novel lead candidate compound into an approved clinical drug takes often more than a decade, and the success rate is very low due to versatile efforts including defining its pharmacokinetics, pharmacodynamics, side effects as well as lack of sufficient efficacy. Thus, strategies are needed to minimize time and costs, while maximizing success rates. A very attractive strategy for novel cancer therapeutic options is the repositioning of already approved drugs. These medicines, approved for the treatment of non-malignant disorders, have already passed some early costs and time, have been tested in humans and are ready for clinical trials as anti-cancer drugs. Here we discuss the repositioning of nonsteroidal anti-inflammatory drugs (NSAID), statins, anti-psychotic drugs, anti-helminthic drugs and vitamin D as anti-tumor agents. We focus on their novel actions and potential for inhibition of cancer growth and metastasis by interfering with target molecules and pathways, which drive these malignant processes. Furthermore, important pre-clinical and clinical data are reviewed herein, which elucidate their therapeutic mechanisms which enable their repositioning for cancer therapy and disruption of metastasis.

Lysophosphatidic acid signaling in ovarian cancer

Lysophosphatidic acid (LPA) is a bioactive phospholipid that is involved in signal transduction between cells. Plasma and ascites levels of LPA are increased in ovarian cancer patients even in the early stages and thus LPA is considered as a potential diagnostic marker for this disease. This review presents the current knowledge regarding LPA signaling in epithelial ovarian cancer. LPA stimulates proliferation, migration and invasion of ovarian cancer cells through regulation of vascular endothelial growth factor, matrix metalloproteinases, urokinase plasminogen activator, interleukin-6, interleukin-8, CXC motif chemokine ligand 12/CXC receptor 4, COX2, cyclin D1, Hippo-Yap and growth-regulated oncogene α concentrations. In this article, all of these targets and signal pathways involved in LPA influence are described.

Co-targeting of Cyclooxygenase-2 and FoxM1 is a viable strategy in inducing anticancer effects in colorectal cancer cells

Background

Cross-talk between deregulated signaling pathways in cancer cells causes uncontrolled growth and proliferation. These cancers cells become more aggressive and quickly develop resistance to therapy. Therefore targeting of these deregulated pathways simultaneously can result in efficient cell death of cancer cells. In this study we investigated co-expression of Cox-2 and FoxM1 in a cohort of colorectal carcinoma (CRC) samples and also examined whether inhibition of Cox-2 and FoxM1 simultaneously can lead to inhibition of cell viability and induction of apoptosis in colorectal cancer cell lines and in vivo xenografts.

Methods

Protein expression of Cox-2 and FoxM1 was determined in a large cohort of 770 clinical CRC samples in a tissue micro-array format by immunohistochemistry. Cell death was measured using live dead assay. Apoptosis was measured by annexin V/PI dual staining. Immunoblotting was performed to examine the expression of proteins. Calcusyn software was utilized to estimate the synergistic doses using chou and Talalay method.

Results

Co-expression of Cox-2 and FoxM1 was detected in 33.3 % (232/697) of CRC’s and associated with an aggressive phenotype characterized by younger age (p = 0.0191), high proliferative index marker; Ki-67 (p = 0.004) and MMP-9 (p = 0.0116) as well as activation of AKT (p = 0.0214). In vitro, inhibition of FoxM1 and Cox-2 with pharmacological inhibitors; Thiostrepton and NS398 resulted in efficient down-regulation of FoxM1 and Cox-2 expression along with in-activation of AKT and inhibition of colony formation, invasion and migratory capability of CRC cells. In addition, there was also inhibition of cell viability and induction of apoptosis via the mitochondrial apoptotic pathway in CRC cell lines. Finally, treatment of CRC xenograft tumors in nude mice with combination of Cox-2 and FoxM1 inhibitors inhibited tumor growth significantly via down-regulation of Cox-2 and FoxM1 expression.

Conclusions

These findings demonstrate that co-expression of Cox-2 and FoxM1 might play a critical role in the pathogenesis of CRC. Therefore, targeting of these pathways simultaneously with sub toxic doses of pharmacological inhibitors can be a potential therapeutic approach for the treatment of this subset of CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0406-1) contains supplementary material, which is available to authorized users.

Role of leptin and leptin receptors in hematological malignancies

Leptin is an adipose-derived cytokine that has an important role in bodyweight homeostasis and energy balance. There are a number of studies which have suggested that leptin and its receptors dysregulation play a critical role in the development of malignancies including hematological malignancies, mainly via activation of the JAK/STAT pathway which regulates downstream signaling pathways such as PI3K/AKT signaling and ERK1/2. In this review, current understandings of leptin/leptin receptors mediated pathogenesis in various lymphoid malignancies are described. Blocking of the leptin receptor might be a unique therapeutic approach for many hematological malignancies.

Dual Targeting of mTOR Activity with Torin2 Potentiates Anticancer Effects of Cisplatin in Epithelial Ovarian Cancer

Mammalian target of rapamycin (mTOR) and phosphatidylinositol 3-kinase (PI3K) are two key components of PI3K/Akt/mTOR signaling pathway. Dysregulation of these pathways have been found in many cancers, including epithelial ovarian cancer (EOC), however, the role of mTOR has not been fully elucidated in Middle Eastern EOC. Therefore, we investigated the activation of mTOR complexes (mTORC1 and mTORC2) in a cohort of 156 EOC from Saudi Arabia by immunohistochemistry in a tissue microarray format. mTORC1 and mTORC2 were found to be activated in 55 of 146 (37.7%) and 63 of 140 (45%) of EOC samples, respectively. mTORC1 was significantly associated with mTORC2 (p < 0.0001) activation and both mTOR complexes were significantly associated with p-AKT (p = 0.0205 and 0.0298) and p-P70S6 (p < 0.0001 and 0.0035), respectively. Interestingly, mTOR activation incurred a poor progression-free survival (PFS) (p = 0.0188) in EOC. Next, the in vitro effect of inactivation of mTOR complexes was evaluated using a second-generation mTOR inhibitor, Torin2, on a panel of EOC cell lines. Torin2 treatment decreased cell viability and induced apoptosis in a dose-dependent manner via inactivation of mTORC1 and mTORC2 and their downstream targets in EOC cell lines. Furthermore, treatment of EOC cells with a subtoxic dose of Torin2 potentiated a cisplatin-induced apoptotic response in EOC cell lines. Finally, we studied the in vivo effect of a combination of Torin2 and cisplatin and found that this combination synergistically inhibited tumor growth in nude mice. These studies highlight the importance of targeting the mTOR survival pathway and suggest that cotreatment with cisplatin and Torin2 may be beneficial for the management of EOC.

Chemopreventive effects of aspirin at a glance

Experimental, epidemiological, and clinical data from the last two decades have each supported the hypothesis that aspirin possesses anticancer properties, and that its use may also reduce the lifetime probability of developing or dying from a number of cancers. Aspirin's ability to act on multiple key metabolic and signaling pathways via inhibition of the cyclooxygenase (COX) enzyme, as well as through COX-independent mechanisms, makes it particularly relevant in the fight against cancer. A growing body of evidence indicates that aspirin may not only reduce cancer risk, but also prevent metastasis and angiogenesis while slowing the rate of mutation-inducing DNA damage. These emerging benefits of aspirin are offset to some extent by the known risks of treatment, such as cardiovascular events and gastrointestinal bleeding. However, it has been shown that pre-treatment risk assessment of individual patients and the use of proton pump inhibitors or Helicobacter pylori eradication therapy concomitantly with aspirin treatment can reduce these potential risks. Thus, the significant benefits of aspirin treatment, coupled with recent data concerning its risks, may prove to tip the balance in favor of aspirin use in cancer prevention.

Distinct effects of anti-inflammatory and anti-thrombotic drugs on cancer characteristics at diagnosis

BACKGROUND

A previous study showed that regular use of low-dose aspirin was associated with smaller tumour size and fewer metastases for colorectal and lung cancer. We aim to explain these distinct effects in terms of the anti-inflammatory and anti-thrombotic properties of aspirin.

METHODS

From the Swedish Cancer Register, we identified patients diagnosed with colorectal and lung cancers between 1st October 2006 and 31st December 2009; each cancer was assessed in terms of tumour size/extent (T), lymph-node (N) and metastatic (M) status. Linkage with the Swedish Prescribed Drug Register was performed to obtain information on the use of low-dose aspirin, anti-inflammatory and anti-thrombotic drugs prior to cancer diagnosis.

RESULTS

We identified 14,743 individuals with colorectal cancer and 5888 with lung cancer. For low-dose aspirin users we observed a statistically significant association with smaller tumour size and fewer metastases. For both cancers, the use of non-aspirin anti-inflammatory drugs was associated with smaller tumour size in all categories T2-T4 odds ratio (OR = 0.76, 95% confidence interval (CI) 0.63-0.92 for T2 versus T1 in colorectal cancer), but not with metastatic status (OR = 0.94, 95% CI 0.84-1.06 in colorectal cancer). In contrast, anti-thrombotic drug use was associated with fewer metastases, but not with tumour categories T2 and T3.

CONCLUSIONS

The results suggest that the use of anti-inflammatories is associated with tumour-growth inhibition at the primary site, while the use of anti-thrombotics is associated with restriction of cancer-cell metastasising capability. These have clinical implications on the potential use of these drugs for chemoprevention or chemotherapy.