Prostaglandin E2 transactivates EGF receptor: a novel mechanism for promoting colon cancer growth and gastrointestinal hypertrophy

A genetic study to identify pathogenic mechanisms and drug targets for benign prostatic hyperplasia: a multi-omics Mendelian randomization study

Benign prostatic hyperplasia (BPH) as a common geriatric disease in urology, the incidence and prevalence are rapidly increasing with the aging society, prompting an urgent need for effective prevention and treatment of BPH. However, limited therapeutic efficacy and higher risk of complications result in the treatment of BPH remaining challenging. The unclear pathogenic mechanism also hampers further exploration of therapeutic approaches for BPH. In this study, we used multi-omics methods to integrate genomics, transcriptomics, immunomics, and metabolomics data and identify biomolecules associated with BPH. We performed transcriptomic imputation, summary data-based Mendelian randomization (SMR), joint/conditional analysis, colocalization analysis, and FOCUS to explore high-confidence genes associated with BPH in blood and prostate tissue. Subsequently, three-step SMR was used to identify the DNA methylation sites regulating high-confidence genes to improve the pathogenic pathways of BPH. We also used cis-instruments of druggable genes to conduct SMR analysis to find potential drug targets for BPH. Finally, we used MR analysis to explore the immune pathways and metabolomics related to BPH. Multiple analytical methods identified BTN3A2 (Blood: TWAS Z score = 5.02912, TWAS P = 4.93 × 10-7; Prostate: TWAS Z score = 4.89, TWAS P = 1.01 × 10-6) and C4A (Blood: TWAS Z score = 4.90754, TWAS P = 9.22 × 10-7; Prostate: TWAS Z score = 5.084, TWAS P = 3.70 × 10-7) as high-confidence genes for BPH and identified the cg14345882-BTN3A2-BPH pathogenic pathway. We also used druggable gene data to identify 30 promising therapeutic target genes, including BTN3A2 and C4A. For MR analysis of immune pathways, we identified immune cell surface molecules as well as the inflammatory factor IL-17 (OR = 1.25, 95% CI = 1.09-1.43, PFDR = 0.12, Maximum likelihood) as risk factors for BPH. In addition, we found that disulfide levels of cysteinylglycine (OR = 1.11, 95% CI = 1.05-1.18, P = 5.18 × 10-4, Weighted median), oxidation levels of cysteinylglycine (OR = 1.09, 95% CI = 1.04-1.14, P = 3.87 × 10-4, Weighted median), and sebacate levels (OR = 1.05, 95% CI = 1.02-1.08, P = 3.0 × 10-4, Maximum likelihood) increase the risk of BPH. This multi-omics study explored biomolecules associated with BPH, improved the pathogenic pathways of BPH, and identified promising therapeutic targets. Our results provide evidence for future studies aimed at developing appropriate therapeutic interventions.

Microbiota-associated mechanisms in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, ranking third in terms of incidence and second as a cause of cancer-related death. There is growing scientific evidence that the gut microbiota plays a key role in the initiation and development of CRC. Specific bacterial species and complex microbial communities contribute directly to CRC pathogenesis by promoting the neoplastic transformation of intestinal epithelial cells or indirectly through their interaction with the host immune system. As a result, a protumoural and immunosuppressive environment is created conducive to CRC development. On the other hand, certain bacteria in the gut microbiota contribute to protection against CRC. In this chapter, we analysed the relationship of the gut microbiota to CRC and the associations identified with specific bacteria. Microbiota plays a key role in CRC through various mechanisms, such as increased intestinal permeability, inflammation and immune system dysregulation, biofilm formation, genotoxin production, virulence factors and oxidative stress. Exploring the interaction between gut microbiota and tumourigenesis is essential for developing innovative therapeutic approaches in the fight against CRC.

Molecular modelling, docking and network analysis of phytochemicals from Haritaki churna: role of protein cross-talks for their action

Phytochemicals are bioactive agents present in medicinal plants with therapeutic values. Phytochemicals isolated from plants target multiple cellular processes. In the current work, we have used fractionation techniques to identify 13 bioactive polyphenols in ayurvedic medicine Haritaki Churna. Employing the advanced spectroscopic and fractionation, structure of bioactive polyphenols was determined. Blasting the phytochemical structure allow us to identify a total of 469 protein targets from Drug bank and Binding DB. Phytochemicals with their protein targets from Drug bank was used to create a phytochemical-protein network comprising of 394 nodes and 1023 edges. It highlights the extensive cross-talk between protein target corresponding to different phytochemicals. Analysis of protein targets from Binding data bank gives a network comprised of 143 nodes and 275 edges. Taking the data together from Drug bank and binding data, seven most prominent drug targets (HSP90AA1, c-Src kinase, EGFR, Akt1, EGFR, AR, and ESR-α) were found to be target of the phytochemicals. Molecular modelling and docking experiment indicate that phytochemicals are fitting nicely into active site of the target proteins. The binding energy of the phytochemicals were better than the inhibitors of these protein targets. The strength and stability of the protein ligand complexes were further confirmed using molecular dynamic simulation studies. Further, the ADMET profiles of phytochemicals extracted from HCAE suggests that they can be potential drug targets. The phytochemical cross-talk was further proven by choosing c-Src as a model. HCAE down regulated c-Src and its downstream protein targets such as Akt1, cyclin D1 and vimentin. Hence, network analysis followed by molecular docking, molecular dynamics simulation and in-vitro studies clearly highlight the role of protein network and subsequent selection of drug candidate based on network pharmacology.Communicated by Ramaswamy H. Sarma.

COX 2-inhibitors; a thorough and updated survey into combinational therapies in cancers

Cyclooxygenase (COX) enzymes are pivotal in inflammation and cancer development. COX-2, in particular, has been implicated in tumor growth, angiogenesis, and immune evasion. Recently, COX-2 inhibitors have arisen as potential therapeutic agents in cancer treatment. In addition, combining COX inhibitors with other treatment modalities has demonstrated the potential to improve therapeutic efficacy. This review aims to investigate the effects of COX inhibition, both alone and in combination with other methods, on signaling pathways and carcinogenesis in various cancers. In this study, a literature search of all major academic databases was conducted (PubMed, Scholar google), including the leading research on the mechanisms of COX-2, COX-2 inhibitors, monotherapy with COX-2 inhibitors, and combining COX-2-inhibitors with chemotherapeutic agents in tumors. The study encompasses preclinical and clinical evidence, highlighting the positive findings and the potential implications for clinical practice. According to preclinical studies, multiple signaling pathways implicated in tumor cell proliferation, survival, invasion, and metastasis can be suppressed by inhibiting COX. In addition, combining COX inhibitors with chemotherapy drugs, targeted therapies, immunotherapies, and miRNA-based approaches has enhanced anti-tumor activity. These results suggest that combination therapy has the potential to overcome resistance mechanisms and improve treatment outcomes. However, caution must be exercised when selecting and administering combination regimens. Not all combinations of COX-2 inhibitors with other drugs result in synergistic effects; some may even have unfavorable interactions. Therefore, personalized approaches that consider the specific characteristics of the cancer and the medications involved are crucial for optimizing therapeutic strategies. In conclusion, as monotherapy or combined with other methods, COX inhibition bears promise in modulating signaling pathways and inhibiting carcinogenesis in various cancers. Additional studies and well-designed clinical trials are required to completely elucidate the efficacy of COX inhibition and combination therapy in enhancing cancer treatment outcomes. This narrative review study provides a detailed summary of COX-2 monotherapy and combination targeted therapy in cancer treatment.

Targeting the EGFR/RAS/RAF signaling pathway in anticancer research: a recent update on inhibitor design and clinical trials (2020-2023)

INTRODUCTION

Recent years have seen significant strides in drug developmenttargeting the EGFR/RAS/RAF signaling pathway which is critical forcell growth and proliferation. Protein-protein interaction networksamong EGFR, RAS, and RAF proteins offer insights for drug discovery. This review discusses the drug design and development efforts ofinhibitors targeting these proteins over the past 3 years, detailingtheir structures, selectivity, efficacy, and combination therapy.Strategies to combat drug resistance and minimize toxicities areexplored, along with future research directions.

AREA COVERED

This review encompasses clinical trials and patents on EGFR, KRAS,and BRAF inhibitors from 2020 to 2023, including advancements indesign and synthesis of proteolysis targeting chimeras (PROTACs) forprotein degradation.

EXPERT OPINION

To tackle drug resistance, designing allosteric fourth-generationEGFR inhibitors is vital. Covalent, allosteric, or combinationaltherapies, along with PROTAC degraders, are key methods to addressresistance and toxicity in KRAS and BRAF inhibitors.

Key regulator PNPLA8 drives phospholipid reprogramming induced proliferation and migration in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and leads to the poorest patient outcomes despite surgery and chemotherapy treatment. Exploring new molecular mechanisms of TNBC that could lead to the development of novel molecular targets are critically important for improving therapeutic options for treating TNBC.

METHODS

We sought to identify novel therapeutic targets in TNBC by combining genomic and functional studies with lipidomic analysis, which included mechanistic studies to elucidate the pathways that tie lipid profile to critical cancer cell properties. Our studies were performed in a large panel of human breast cancer cell lines and patient samples.

RESULTS

Comprehensive lipid profiling revealed that phospholipid metabolism is reprogrammed in TNBC cells. We discovered that patatin-like phospholipase domain-containing lipase 8 (PNPLA8) is overexpressed in TNBC cell lines and tissues from breast cancer patients. Silencing of PNPLA8 disrupted phospholipid metabolic reprogramming in TNBC, particularly affecting the levels of phosphatidylglycerol (PG), phosphatidylcholine (PC), lysophosphatidylcholine (LPC) and glycerophosphocholine (GPC). We showed that PNPLA8 is essential in regulating cell viability, migration and antioxidation in TNBC cells and promoted arachidonic acid and eicosanoid production, which in turn activated PI3K/Akt/Gsk3β and MAPK signaling.

CONCLUSIONS

Our study highlights PNPLA8 as key regulator of phospholipid metabolic reprogramming and malignant phenotypes in TNBC, which could be further developed as a novel molecular treatment target.

Probenecid ameliorates testosterone-induced benign prostatic hyperplasia: Implications of PGE-2 on ADAM-17/EGFR/ERK1/2 signaling cascade

Benign prostatic hyperplasia (BPH) is one of the most prevalent clinical disorders in the elderly. Probenecid (Prob) is a well-known FDA-approved therapy for gout owing to its uricosuric effect. The present study evaluated the use of Prob for BPH as a COX-2 inhibitor. Prob (100 and 200 mg/kg) was intraperitoneally injected into male Wistar rats daily for 3 weeks. In the second week, testosterone (3 mg/kg) was subcutaneously injected to induce BPH. Compared with BPH-induced rats, Prob treatment reduced prostate weight and index and improved histopathological architecture. The protease activity of ADAM-17/TACE and its ligands (TGF-α and TNF-α) were regulated by prob, which in turn abolished EGFR phosphorylation, and several inflammatory mediators (COX-2, PGE2, NF-κB (p65), and IL-6) were suppressed. By reducing the nuclear import of extracellular regulated kinase protein 1/2 (ERK1/2), Prob helped re-establish the usual equilibrium between antiapoptotic proteins like Bcl-2 and cyclin D1 and proapoptotic proteins like Bax. All of these data point to Prob as a promising treatment for BPH because of its ability to inhibit COX-2-syntheiszed PGE2 and control the ADAM-17/TGF-α-induced EGFR/ERK1/2 signaling cascade. These findings might help to repurpose Prob for the treatment of BPH.

The multiple functions of miR-574-5p in the neuroblastoma tumor microenvironment

Neuroblastoma is the most common extracranial solid tumor in childhood and arises from neural crest cells of the developing sympathetic nervous system. Prostaglandin E2 (PGE2) has been identified as a key pro-inflammatory mediator of the tumor microenvironment (TME) that promotes neuroblastoma progression. We report that the interaction between the microRNA miR-574-5p and CUG-binding protein 1 (CUGBP1) induces the expression of microsomal prostaglandin E2 synthase 1 (mPGES-1) in neuroblastoma cells, which contributes to PGE2 biosynthesis. PGE2 in turn specifically induces the sorting of miR-574-5p into small extracellular vesicles (sEV) in neuroblastoma cell lines. sEV are one of the major players in intercellular communication in the TME. We found that sEV-derived miR-574-5p has a paracrine function in neuroblastoma. It acts as a direct Toll-like receptor 7/8 (TLR7/8) ligand and induces α-smooth muscle actin (α-SMA) expression in fibroblasts, contributing to fibroblast differentiation. This is particularly noteworthy as it has an opposite function to that in the TME of lung carcinoma, another PGE2 dependent tumor type. Here, sEV-derived miR-574-5p has an autokrine function that inhibits PGE2 biosynthesis in lung cancer cells. We report that the tetraspanin composition on the surface of sEV is associated with the function of sEV-derived miR-574-5p. This suggests that the vesicles do not only transport miRs, but also appear to influence their mode of action.

Prostaglandin-endoperoxide synthase 2 (PTGS2) gene expression and its association with genes regulating the VEGF signaling pathway in head and neck squamous cell carcinoma

Introduction

The PTGS2 gene codes for the cyclooxygenase-2 (COX-2) enzyme that catalyzes the committed step in prostaglandin (PG) synthesis. Various in-vivo and in-vitro data suggest that prostaglandin E2 mediates as a signaling molecule for activating the VEGF signaling pathway (VSP), forming an association between COX-2 and VSP. Several chemotherapy regimens increasingly rely on preventing the synthesis of PGs. The targeted and metronomic chemotherapy agents, which suppress the COX-2 enzymes, have a major role in suppressing the oral cancer cascade. Hence, this study was designed to understand the pattern of PTGS2 expression and genes regulating VSP in head and neck cancers.

Methods

PTGS2 expression was analyzed in the TCGA database computationally with the help of the UALCAN web-server. The expression of VEGF signaling pathway genes was mined, and their expression pattern was determined. Co-expression analysis was done to elucidate the association between VEGF signaling genes and PTGS2. The ShineyGo web server was used for gene set enrichment.

Results

Significantly high PTGS2 expression was observed in tumor samples. Further genes regulating VEGF signaling were significantly overexpressed in tumor samples. Co-expression analysis results showed a significant positive correlation between PTGS2 and angiogenesis-regulating genes. The majority of the genes were enriched for angiogenesis pathways.

Conclusion

PTGS2 was significantly expressed in head and neck cancer, and its expression was associated with genes regulating angiogenesis.

Towards targeting EGFR and COX-2 inhibitors: comprehensive computational studies on the role of chlorine group in novel thienyl-pyrazoline derivative

To enhance the effectiveness of chemotherapy and overcome resistance, scientists must develop novel drugs or scaffolds that have a combined effect, such as the inhibition of EGFR and COX-2. This research employed virtual screening techniques, such as docking, and dynamics simulation, to predict chlorinated thienyl-pyrazoline derivatives that inhibit these proteins. The study proposed eleven (11) ligands with binding energies ranging from -7.8 kcal/mol to -8.7 kcal/mol for EGFR and -6.4 kcal/mol to -8.4 kcal/mol for COX-2. Ligands P1 and P11 exhibited the highest binding affinity for both proteins. The results of RMSD, RMSF, RoG, SASA the number of hydrogen bonds, and BAR free binding energy demonstrated the good stability of ligands P1 and P11 when binding to both proteins over 180 ns simulations. In addition, the absorption, distribution, metabolism, excretion, and toxicity properties of the selected ligands were assessed to predict their toxicity and drug likeliness. Based on the results, these compounds can be proposed for further synthesis and in vitro studies.Communicated by Ramaswamy H. Sarma.

Cyclooxygenase and Lipoxygenase Gene Expression in the Inflammogenesis of Colorectal Cancer: Correlated Expression of EGFR, JAK STAT and Src Genes, and a Natural Antisense Transcript, RP11-C67.2.2

We examined the expression of major inflammatory genes, cyclooxygenase-1, 2 (COX1, COX2), arachidonate-5-lipoxygenase (ALOX5), and arachidonate-5-lipoxygenase activating protein (ALOX5AP) among 469 tumor specimens of colorectal cancer in The Cancer Genome Atlas (TCGA). Among 411 specimens without mutations in mismatch repair (MMR) genes, the mean expression of each of the inflammatory genes ranked above the 80th percentile, and the overall mean cyclooxygenase expression (COX1+COX2) ranked in the upper 99th percentile of all genes. Similar levels were observed for 58 cases with MMR mutations. Pearson correlation coefficients exceeding r = 0.70 were observed between COX and LOX mRNA levels with genes of major cell-signaling pathways involved in tumorigenesis (Src, JAK STAT, MAPK, PI3K). We observed a novel association (r = 0.78) between ALOX5 expression and a natural antisense transcript (NAT), RP11-67C2.2, a long non-coding mRNA gene, 462 base pairs in length that is located within the terminal intron of the ALOX5 gene on chromosome 10q11.21. Tumor-promoting genes highly correlated with the expression of COX1, COX2, ALOX5 and ALOX5AP are known to increase mitogenesis, mutagenesis, angiogenesis, cell survival, immunosuppression and metastasis in the inflammogenesis of colorectal cancer. These genes and the novel NAT, RP1167C2.2 are potential molecular targets for chemoprevention and therapy of colorectal cancer.

Cooperation between Prostaglandin E2 and Epidermal Growth Factor Receptor in Cancer Progression: A Dual Target for Cancer Therapy

It is recognized that prostaglandin E2 (PGE2) is one key lipid mediator involved in chronic inflammation, and it is directly implicated in tumor development by regulating cancer cell growth and migration, apoptosis, epithelial-mesenchymal transition, angiogenesis, and immune escape. In addition, the expression of the enzymes involved in PGE2 synthesis, cyclooxygenase 2 (COX-2) and microsomal prostaglandin E synthase 1 (mPGES1), positively correlates with tumor progression and aggressiveness, clearly indicating the crucial role of the entire pathway in cancer. Moreover, several lines of evidence suggest that the COX2/mPGES1/PGE2 inflammatory axis is involved in the modulation of epidermal growth factor receptor (EGFR) signaling to reinforce the oncogenic drive of EGFR activation. Similarly, EGFR activation promotes the induction of COX2/mPGES1 expression and PGE2 production. In this review, we describe the interplay between COX2/mPGES1/PGE2 and EGFR in cancer, and new therapeutic strategies that target this signaling pathway, to outline the importance of the modulation of the inflammatory process in cancer fighting.

Natural-Derived COX-2 Inhibitors as Anticancer Drugs: A Review of their Structural Diversity and Mechanism of Action

Cyclooxygenase-2 (COX-2) is a key-type enzyme playing a crucial role in cancer development, making it a target of high interest for drug designers. In the last two decades, numerous selective COX-2 inhibitors have been approved for various clinical conditions. However, data from clinical trials propose that the prolonged use of COX-2 inhibitors is associated with life-threatening cardiovascular side effects. The data indicate that a slight structural modification can help develop COX-2 selective inhibitors with comparative efficacy and limited side effects. In this regard, secondary metabolites from natural sources offer great hope for developing novel COX-2 inhibitors with potential anticancer activity. In recent years, various nature-derived organic scaffolds are being explored as leads for developing new COX-2 inhibitors. The current review attempts to highlight the COX-2 inhibition activity of some naturally occurring secondary metabolites, concerning their capacity to inhibit COX-1 and COX-2 enzymes and inhibit cancer development, aiming to establish a structure-activity relationship.

A reversible SRC-relayed COX2 inflammatory program drives resistance to BRAF and EGFR inhibition in BRAFV600E colorectal tumors

BRAF^V600E mutation confers a poor prognosis in metastatic colorectal cancer (CRC) despite combinatorial targeted therapies based on the latest understanding of signaling circuitry. To identify parallel resistance mechanisms induced by BRAF-MEK-EGFR co-targeting, we used a high-throughput kinase activity mapping platform. Here we show that SRC kinases are systematically activated in BRAF^V600E CRC following targeted inhibition of BRAF ± EGFR and that coordinated targeting of SRC with BRAF ± EGFR increases treatment efficacy in vitro and in vivo. SRC drives resistance to BRAF ± EGFR targeted therapy independently of ERK signaling by inducing transcriptional reprogramming through β-catenin (CTNNB1). The EGFR-independent compensatory activation of SRC kinases is mediated by an autocrine prostaglandin E₂ loop that can be blocked with cyclooxygenase-2 (COX2) inhibitors. Co-targeting of COX2 with BRAF + EGFR promotes durable suppression of tumor growth in patient-derived tumor xenograft models. COX2 inhibition represents a drug-repurposing strategy to overcome therapeutic resistance in BRAF^V600E CRC.

Lipid Metabolic Alterations in KRAS Mutant Tumors: Unmasking New Vulnerabilities for Cancer Therapy

KRAS is one of the most commonly mutated genes, an event that leads to development of highly aggressive and resistant to any type of available therapy tumors. Mutated KRAS drives a complex network of lipid metabolic rearrangements to support the adaptation of cancer cells to harsh environmental conditions and ensure their survival. Because there has been only a little success in the continuous efforts of effectively targeting KRAS-driven tumors, it is of outmost importance to delineate the exact mechanisms of how they get rewired, leading to this distinctive phenotype. Therefore, the aim of this review is to summarize the available data acquired over the last years with regard to the lipid metabolic regulation of KRAS-driven tumors and elucidate their specific characteristics in an attempt to unravel novel therapeutic targets.

Cyclooxygenase-2 activates EGFR-ERK1/2 pathway via PGE2-mediated ADAM-17 signaling in testosterone-induced benign prostatic hyperplasia

OBJECTIVE AND DESIGN

Prostatic inflammation is the driving force in benign prostatic hyperplasia (BPH). This work investigated the potential modulatory effect of COX-2 inhibition on ADAM-17/EGFR/ERK1/2 axis.

MATERIALS OR SUBJECTS

Adult male Wistar rats were used.

TREATMENT

Celecoxib (10 and 20 mg/kg; i.p.) was injected i.p. daily for three weeks. Testosterone (TST) (3 mg/kg; s.c.) was used to induce BPH.

METHODS

Prostatic inflammation and hyperplasia were assessed by organ weight and histopathology. Inflammatory mediators were measured using ELISA technique. Protein analysis was performed using western blotting and immunohistochemistry. Gene expression analysis was performed using qRT-PCR. Statistical analyses included one-way ANOVA and Tukey's multiple comparison test.

RESULTS

Testosterone-treated rats had a marked increase in COX-2, prostate weight, and index. Moreover, TST-induced COX-2 was inferred from cytoskeletal changes and was attributable to the overexpression of PGE2, NF-κB (p65), and IL-6. COX-2-derived PGE2 increased the activity of ADAM-17, TGF-α, and TNF-α. Consequently, EGFR-ERK1/2 pathway was over-activated, disrupting anti-apoptotic Bcl-2, cyclin D1, and pro-apoptotic Bax. Celecoxib reversed these effects.

CONCLUSION

COX-2 stimulates the ERK1/2 pathway via PGE2-ADAM-17-catalyzed shedding of TGF-α in testosterone-induced BPH. The results indicate a functional correlation between inflammation and hyperplasia in BPH.

Physicochemical aspects of the tumour microenvironment as drivers of vasculogenic mimicry

Tumour vascularisation is vital for cancer sustainment representing not only the main source of nutrients and oxygen supply but also an escape route for single or clustered cancer cells that, once detached from the primary mass, enter the blood circulation and disseminate to distant organs. Among the mechanisms identified to contribute to tumour vascularisation, vasculogenic mimicry (VM) is gaining increasing interest in the scientific community representing an intriguing target for cancer treatment. VM indeed associates with highly aggressive tumour phenotypes and strongly impairs patient outcomes. Differently from vessels of healthy tissues, tumour vasculature is extremely heterogeneous and tortuous, impeding efficient chemotherapy delivery, and at the meantime hyperpermeable and thus extremely accessible to metastasising cancer cells. Moreover, tumour vessel disorganisation creates a self-reinforcing vicious circle fuelling cancer malignancy and progression. Because of the inefficient oxygen delivery and metabolic waste removal from tumour vessels, many cells within the tumour mass indeed experience hypoxia and acidosis, now considered hallmarks of cancer. Being strong inducers of vascularisation, therapy resistance, inflammation and metastasis, hypoxia and acidosis create a permissive microenvironment for cancer progression and dissemination. Along with these considerations, we decided to focus our attention on the relationship between hypoxia/acidosis and VM. Indeed, besides tumour angiogenesis, VM is strongly influenced by both hypoxia and acidosis, which could potentiate each other and fuel this vicious circle. Thus, targeting hypoxia and acidosis may represent a potential target to treat VM to impair tumour perfusion and cancer cell sustainment.

A novel prognostic index of stomach adenocarcinoma based on immunogenomic landscape analysis and immunotherapy options

Stomach adenocarcinoma (STAD) is one of the most common malignant tumors worldwide. In this study, we attempted to construct a valid immune-associated gene prognostic index risk model that can predict the survival of patients with STAD and the efficacy of immune checkpoint inhibitors (ICIs) treatment. Transcriptome, clinical, and gene mutational data were obtained from the TCGA database. Immune-related genes were downloaded from the ImmPort and InnateDB databases. A total of 493 immune-related genes were identified to be enriched in functions associated with immune response, as well as in immune and tumor-related pathways. Further, 36 candidate genes related to the overall survival (OS) of STAD were obtained by weighted gene co-expression network analysis (WGCNA). Next, based on a Cox regression analysis, we constructed an immune-associated gene prognostic index (IAGPI) risk model based on eight genes, which was verified using the GEO STAD cohort. The patients were divided into two subsets according to their risk score. Patients in the low-risk group had better OS than those in the high-risk group. In the low-risk group, there were more CD8, activated memory CD4, and follicular helper T cells, and M1 macrophages, whereas monocytes, M2 macrophages, eosinophils, and neutrophils were more abundant in the high-risk group. The patients in the low-risk group were more sensitive to ICIs therapy. The IAGPI risk model can precisely predict the prognosis, reflect the tumor immune microenvironment, and predict the efficacy of ICIs therapy in patients with STAD.

Pou3f1 mediates the effect of Nfatc3 on ulcerative colitis-associated colorectal cancer by regulating inflammation

Background

Ulcerative colitis-associated colorectal cancer (UC-CRC) is an important complication of ulcerative colitis. Pou3f1 (POU class 3 homeobox 1) is a critical regulator for developmental events and cellular biological processes. However, the role of Pou3f1 in the development of UC-CRC is unclear.

Methods

In vivo, a UC-CRC mouse model was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS). Body weight, colon length, mucosal damage, tumor formation, and survival rate were assessed to determine the progression of UC-CRC. Western blot, quantitative real-time PCR, ELISA, immunohistochemistry, immunofluorescence and TUNEL were performed to examine the severity of inflammation and tumorigenesis. In vitro, LPS-treated mouse bone marrow-derived macrophages (BMDMs) and RAW264.7 cells were used to study the role of Pou3f1 in inflammation. ChIP and luciferase reporter assays were used to confirm the interaction between Nfatc3 and Pou3f1.

Results

Pou3f1 expression was increased in the colons of UC-CRC mice, and its inhibition attenuated mucosal injury, reduced colon tumorigenesis and increased survival ratio. Knockdown of Pou3f1 suppressed cell proliferation and increased cell death in colon tumors. Both the in vivo and in vitro results showed that Pou3f1 depletion reduced the production of proinflammation mediators. In addition, ChIP and luciferase reporter assays demonstrated that Nfatc3 directly bound with the Pou3f1 promoter to induce its expression. The effect of Nfatc3 on the inflammatory response in macrophages was suppressed by Pou3f1 knockdown.

Conclusion

Overall, it outlines that Pou3f1 mediates the role of Nfatc3 in regulating macrophage inflammation and carcinogenesis in UC-CRC development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00374-0.

The Potential Tumor-Suppressor DHRS7 Inversely Correlates with EGFR Expression in Prostate Cancer Cells and Tumor Samples

Simple Summary

Prostate cancer is one of the most common malignancies in men. Current therapies are initially effective but resistance often develops, leading to tumor recurrence and death. Further research on new players, mechanisms involved in prostate cancer, and therapy resistance is needed. We studied the role of DHRS7, a potential tumor suppressor with currently unknown physiological function, in prostate cancer cells using proteome and gene expression analyses. Despite the fact that DHRS7 can inactivate 5α-dihydrotestosterone, its effect on prostate cancer cells seems to be unrelated to androgen metabolism. When comparing three widely studied prostate cancer cell lines, we observed a negative correlation between DHRS7 and EGFR expression. DHRS7 knockdown enhanced EGFR expression, while knockdown of EGFR tended to increase DHRS7 expression. Importantly, DHRS7 expression negatively correlates with EGFR expression and positively with survival rates in prostate cancer patients. This study suggests a tumor-suppressor role for DHRS7 by modulating EGFR expression in prostate cancer.

Abstract

Prostate cancer (PCa), one of the most common malignancies in men, typically responds to initial treatment, but resistance to therapy often leads to metastases and death. The dehydrogenase/reductase 7 (DHRS7, SDR34C1) is an “orphan” enzyme without known physiological function. DHRS7 was previously found to be decreased in higher-stage PCa, and siRNA-mediated knockdown increased the aggressiveness of LNCaP cells. To further explore the role of DHRS7 in PCa, we analyzed the proteome of LNCaP cells following DHRS7 knockdown to assess potentially altered pathways. Although DHRS7 is able to inactivate 5α-dihydrotestosterone, DHRS7 knockdown did not affect androgen receptor (AR) target gene expression, and its effect on PCa cells seems to be androgen-independent. Importantly, proteome analyses revealed increased expression of epidermal growth factor receptor (EGFR), which was confirmed by RT-qPCR and Western blotting. Comparison of AR-positive LNCaP with AR-negative PC-3 and DU145 PCa cell lines revealed a negative correlation between DHRS7 and EGFR expression. Conversely, EGFR knockdown enhanced DHRS7 expression in these cells. Importantly, analysis of patient samples revealed a negative correlation between DHRS7 and EGFR expression, both at the mRNA and protein levels, and DHRS7 expression correlated positively with patient survival rates. These results suggest a protective role for DHRS7 in PCa.

Targeting mTOR in the Context of Diet and Whole-body Metabolism

The mechanistic target of the rapamycin (mTOR) signaling pathway is the central regulator of cell growth and proliferation by integrating growth factor and nutrient availability. Under healthy physiological conditions, this process is tightly coordinated and essential to maintain whole-body homeostasis. Not surprisingly, dysregulated mTOR signaling underpins several diseases with increasing incidence worldwide, including obesity, diabetes, and cancer. Consequently, there is significant clinical interest in developing therapeutic strategies that effectively target this pathway. The transition of mTOR inhibitors from the bench to bedside, however, has largely been marked with challenges and shortcomings, such as the development of therapy resistance and adverse side effects in patients. In this review, we discuss the current status of first-, second-, and third-generation mTOR inhibitors as a cancer therapy in both preclinical and clinical settings, with a particular emphasis on the mechanisms of drug resistance. We focus especially on the emerging role of diet as an important environmental determinant of therapy response, and posit a conceptual framework that links nutrient availability and whole-body metabolic states such as obesity with many of the previously defined processes that drive resistance to mTOR-targeted therapies. Given the role of mTOR as a central integrator of cell metabolism and function, we propose that modulating nutrient inputs through dietary interventions may influence the signaling dynamics of this pathway and compensatory nodes. In doing so, new opportunities for exploiting diet/drug synergies are highlighted that may unlock the therapeutic potential of mTOR inhibitors as a cancer treatment.

Biomarkers for the prediction of esophageal cancer neoadjuvant chemoradiotherapy response: A systemic review

Neoadjuvant chemoradiotherapy followed by surgery has been established as the standard treatment for locally advanced esophageal cancer. For patients with complete regression after neoadjuvant chemotherapy, active surveillance rather than planned surgery has been proposed as an organ preservation strategy. Reliable biomarkers to predict chemoradiation response is needed. We first summarized the previous reports of biomarkers with the potential to predict the treatment response of esophageal cancer neoadjuvant chemoradiotherapy. These traditional biomarkers are classified into three groups: genetic biomarkers, RNA biomarkers, and protein biomarkers. We then summarized some special types of biomarkers, including metabolites biomarkers, immune and tumor microenvironment biomarkers, and microbiome biomarkers.

APC and TP53 Mutations Predict Cetuximab Sensitivity across Consensus Molecular Subtypes

Simple Summary

Colorectal cancer (CRC) is a major cause of cancer deaths. Cetuximab is an FDA-approved, underutilized therapeutic targeting the epidermal growth factor receptor (EGFR) in metastatic CRC. To date, despite selection of patients with wild-type RAS, it is still difficult to identify patients who may benefit from EGFR inhibitor (e.g., cetuximab) therapy. Our aim is to molecularly classify CRC patients to better identify subpopulations sensitive to EGFR targeted therapy. APC and TP53 are two major tumor suppressor genes in CRC whose mutations contribute to tumor initiation and progression and may identify cetuximab-sensitive tumors. Recently, it has been suggested that the consensus molecular subtype (CMS) classification may be used to help identify cetuximab-sensitive patients. Here, we report an analysis of multiple CRC tumor/PDX/cell line datasets using combined APC and TP53 mutations to refine the CMS classification to better predict responses to cetuximab to improve patient outcomes.

Abstract

Recently, it was suggested that consensus molecular subtyping (CMS) may aide in predicting response to EGFR inhibitor (cetuximab) therapies. We recently identified that APC and TP53 as two tumor suppressor genes, when mutated, may enhance cetuximab sensitivity and may represent easily measured biomarkers in tumors or blood. Our study aimed to use APC and TP53 mutations (AP) to refine the CMS classification to better predict responses to cetuximab. In total, 433 CRC tumors were classified into CMS1-4 subtypes. The cetuximab sensitivity (CTX-S) signature scores of AP vs. non-AP tumors were determined across each of the CMS classes. Tumors harboring combined AP mutations were predominantly enriched in the CMS2 class, and to a lesser degree, in the CMS4 class. On the other hand, AP mutated CRCs had significantly higher CTX-S scores compared to non-AP CRCs across all CMS classes. Similar results were also obtained in independent TCGA tumor collections (n = 531) and in PDMR PDX/PDO/PDC models (n = 477). In addition, the in vitro cetuximab growth inhibition was preferentially associated with the CMS2 cell lines harboring A/P genotypes. In conclusion, the AP mutation signature represents a convenient biomarker that refines the CMS classification to identify CRC subpopulations predicted to be sensitive to EGFR targeted therapies.

The 'Yin and Yang' of Cancer Cell Growth and Mechanosensing

In cancer, two unique and seemingly contradictory behaviors are evident: on the one hand, tumors are typically stiffer than the tissues in which they grow, and this high stiffness promotes their malignant progression; on the other hand, cancer cells are anchorage-independent-namely, they can survive and grow in soft environments that do not support cell attachment. How can these two features be consolidated? Recent findings on the mechanisms by which cells test the mechanical properties of their environment provide insight into the role of aberrant mechanosensing in cancer progression. In this review article, we focus on the role of high stiffness on cancer progression, with particular emphasis on tumor growth; we discuss the mechanisms of mechanosensing and mechanotransduction, and their dysregulation in cancerous cells; and we propose that a 'yin and yang' type phenomenon exists in the mechanobiology of cancer, whereby a switch in the type of interaction with the extracellular matrix dictates the outcome of the cancer cells.

The Critical Role of Growth Factors in Gastric Ulcer Healing: The Cellular and Molecular Mechanisms and Potential Clinical Implications

In this article we review the cellular and molecular mechanisms of gastric ulcer healing. A gastric ulcer (GU) is a deep defect in the gastric wall penetrating through the entire mucosa and the muscularis mucosae. GU healing is a regeneration process that encompasses cell dedifferentiation, proliferation, migration, re-epithelialization, formation of granulation tissue, angiogenesis, vasculogenesis, interactions between various cells and the matrix, and tissue remodeling, all resulting in scar formation. All these events are controlled by cytokines and growth factors (e.g., EGF, TGFα, IGF-1, HGF, bFGF, TGFβ, NGF, VEGF, angiopoietins) and transcription factors activated by tissue injury. These growth factors bind to their receptors and trigger cell proliferation, migration, and survival pathways through Ras, MAPK, PI3K/Akt, PLC-γ, and Rho/Rac/actin signaling. The triggers for the activation of these growth factors are tissue injury and hypoxia. EGF, its receptor, IGF-1, HGF, and COX-2 are important for epithelial cell proliferation, migration, re-epithelialization, and gastric gland reconstruction. VEGF, angiopoietins, bFGF, and NGF are crucial for blood vessel regeneration in GU scars. The serum response factor (SRF) is essential for VEGF-induced angiogenesis, re-epithelialization, and blood vessel and muscle restoration. Local therapy with cDNA of human recombinant VEGF165 in combination with angiopoietin1, or with the NGF protein, dramatically accelerates GU healing and improves the quality of mucosal restoration within ulcer scars. The future directions for accelerating and improving healing include local gene and protein therapies with growth factors, their combinations, and the use of stem cells and tissue engineering.

GPCR-ErbB transactivation pathways and clinical implications

Cell surface receptors including the epidermal growth factor receptor (EGFR) family and G-protein coupled receptors (GPCRs) play quintessential roles in physiology, and in diseases, including cardiovascular diseases. While downstream signaling from these individual receptor families has been well studied, the cross-talk between EGF and GPCR receptor families is still incompletely understood. Including members of both receptor families, the number of receptor and ligand combinations for unique interactions is vast, offering a frontier of pharmacologic targets to explore for preventing and treating disease. This molecular cross-talk, called receptor transactivation, is reviewed here with a focus on the cardiovascular system featuring the well-studied GPCR receptors, but also discussing less-studied receptors from both families for a broad understanding of context of expansile interactions, repertoire of cellular signaling, and disease consequences. Attention is given to cell type, level of chronicity, and disease context given that transactivation and comorbidities, including diabetes, hypertension, coronavirus infection, impact cardiovascular disease and health outcomes.

Genetic polymorphisms as non-modifiable susceptibility factors to laryngeal cancer

Laryngeal squamous cell carcinoma (LSCC) is a highly disabling disease to the patient, affecting speech, swallowing and respiratory skills. Smoking and alcohol abuse are principal risk factors linked to this disease. Genetic factors can be involved in carcinogenesis by controlling the cell cycle, cell survival, angiogenesis, and invasiveness. Single nucleotide polymorphisms (SNPs) involving specific genes could modulate the risk of LSCC related to known carcinogens by modifying cellular responses, but not all genetic associations are known.

In a case–control study, we assess the associations between cyclooxygenase-2 (COX2), epidermal growth factor (EGF), EGF receptor (EGFR), and tumor suppressor P53 SNPs on the risk of LSCC development in the Chilean population. A total of 85 LSCC patients and 95 healthy volunteers were recruited. SNPs genotype were analyzed from genomic DNA by Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (RFLP) and associations were estimated by odds ratios (ORs) using unconditional logistic regressions.

A significant association between COX2 and TP53 SNP and LSCC risk was found, with an OR = 3.27 for COX2 c.-1329A>G (rs689466) SNP, and an OR = 1.94 for TP53 c.215C>G, Pro72Arg (rs1042522) SNP. These findings suggest that COX2 c.-1329A>G and TP53 c.215C>G (Pro72Arg) SNPs may be risk factors for LSCC.

Through this research, we identify two low penetrance genetic variants that may be evaluated as novel biomarkers for this disease, in South American Mestizo populations.

Targeting Inflammatory Mediators: An Anticancer Mechanism of Thymoquinone Action

BACKGROUND

Thymoquinone is a promising anticancer molecule, the chemopreventive role of which is well-known at least in vitro and in the animal model. In this review article, we focused on the anti-inflammatory activities of thymoquinone in cancer cells.

METHOD

Research data on inflammation, cancer and thymoquinone were acquired from PubMed, Scopus, Web of Science and Google Scholar. We reviewed papers published since the mid of the last century, and the most cited papers of the last ten years.

RESULTS

Studies indicate that thymoquinone possesses immunomodulatory activities, in addition to its chemopreventive role, as thymoquinone can target and modulate inflammatory molecules, like nuclear factor kappa B (NF-κβ), interleukins, tumor necrosis factor-α (TNF-α), and certain growth factors. As chronic inflammation plays an important role in cancer development, controlling inflammatory pathways is an important mechanism of an anticancer molecule, and modulation of inflammatory pathways might be one of the key mechanisms of thymoquinone's anticancer activities.

CONCLUSION

This article reviewed the role of inflammation on cancer development, and the action of thymoquinone on inflammatory molecules, which have been proved in vitro and in vivo. Much attention is required for studying the role of thymoquinone in immunotherapeutics and developing this molecule as a future anticancer drug.

Nonmicrobial Activation of TLRs Controls Intestinal Growth, Wound Repair, and Radioprotection

TLRs, key components of the innate immune system, recognize microbial molecules. However, TLRs also recognize some nonmicrobial molecules. In particular, TLR2 and TLR4 recognize hyaluronic acid, a glycosaminoglycan in the extracellular matrix. In neonatal mice endogenous hyaluronic acid binding to TLR4 drives normal intestinal growth. Hyaluronic acid binding to TLR4 in pericryptal macrophages results in cyclooxygenase2- dependent PGE2 production, which transactivates EGFR in LGR5+ crypt epithelial stem cells leading to increased proliferation. The expanded population of LGR5+ stem cells leads to crypt fission and lengthening of the intestine and colon. Blocking this pathway at any point (TLR4 activation, PGE2 production, EGFR transactivation) results in diminished intestinal and colonic growth. A similar pathway leads to epithelial proliferation in wound repair. The repair phase of dextran sodium sulfate colitis is marked by increased epithelial proliferation. In this model, TLR2 and TLR4 in pericryptal macrophages are activated by microbial products or by host hyaluronic acid, resulting in production of CXCL12, a chemokine. CXCL12 induces the migration of cyclooxygenase2-expressing mesenchymal stem cells from the lamina propria of the upper colonic crypts to a site adjacent to LGR5+ epithelial stem cells. PGE2 released by these mesenchymal stem cells transactivates EGFR in LGR5+ epithelial stem cells leading to increased proliferation. Several TLR2 and TLR4 agonists, including hyaluronic acid, are radioprotective in the intestine through the inhibition of radiation-induced apoptosis in LGR5+ epithelial stem cells. Administration of exogenous TLR2 or TLR4 agonists activates TLR2/TLR4 on pericryptal macrophages inducing CXCL12 production with migration of cyclooxygenase2-expressing mesenchymal stem cells from the lamina propria of the villi to a site adjacent to LGR5+ epithelial stem cells. PGE2 produced by these mesenchymal stem cells, blocks radiation-induced apoptosis in LGR5+ epithelial stem cells by an EGFR mediated pathway.

Interplay Between EGFR and the Platelet-Activating Factor/PAF Receptor Signaling Axis Mediates Aggressive Behavior of Cervical Cancer

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase widely expressed in cervical tumors, being correlated with adverse clinical outcomes. EGFR may be activated by a diversity of mechanisms, including transactivation by G-protein coupled receptors (GPCRs). Studies have also shown that platelet-activating factor (PAF), a pro-inflammatory phospholipid mediator, plays an important role in the cancer progression either by modulating the cancer cells or the tumor microenvironment. Most of the PAF effects seem to be mediated by the interaction with its receptor (PAFR), a member of the GPCRs family. PAFR- and EGFR-evoked signaling pathways contribute to tumor biology; however, the interplay between them remains uninvestigated in cervical cancer. In this study, we employed The Cancer Genome Atlas (TCGA) and cancer cell lines to evaluate possible cooperation between EGFR, PAFR, and lysophosphatidylcholine acyltransferases (LPCATs), enzymes involved in the PAF biosynthesis, in the context of cervical cancer. It was observed a strong positive correlation between the expression of EGFR × PAFR and EGFR × LPCAT2 in 306 cervical cancer samples. The increased expression of LPCAT2 was significantly correlated with poor overall survival. Activation of EGFR upregulated the expression of PAFR and LPCAT2 in a MAPK-dependent fashion. At the same time, PAF showed the ability to transactivate EGFR leading to ERK/MAPK activation, cyclooxygenase-2 (COX-2) induction, and cell migration. The positive crosstalk between the PAF-PAFR axis and EGFR demonstrates a relevant linkage between inflammatory and growth factor signaling in cervical cancer cells. Finally, combined PAFR and EGFR targeting treatment impaired clonogenic capacity and viability of aggressive cervical cancer cells more strongly than each treatment separately. Collectively, we proposed that EGFR, LPCAT2, and PAFR emerge as novel targets for cervical cancer therapy.

Prostaglandin E2 and Cancer: Insight into Tumor Progression and Immunity

The involvement of inflammation in cancer progression has been the subject of research for many years. Inflammatory milieu and immune response are associated with cancer progression and recurrence. In different types of tumors, growth and metastatic phenotype characterized by the epithelial mesenchymal transition (EMT) process, stemness, and angiogenesis, are increasingly associated with intrinsic or extrinsic inflammation. Among the inflammatory mediators, prostaglandin E2 (PGE2) supports epithelial tumor aggressiveness by several mechanisms, including growth promotion, escape from apoptosis, transactivation of tyrosine kinase growth factor receptors, and induction of angiogenesis. Moreover, PGE2 is an important player in the tumor microenvironment, where it suppresses antitumor immunity and regulates tumor immune evasion, leading to increased tumoral progression. In this review, we describe the current knowledge on the pro-tumoral activity of PGE2 focusing on its role in cancer progression and in the regulation of the tumor microenvironment.

Lipid metabolism in colon cancer: Role of Liver X Receptor (LXR) and Stearoyl-CoA Desaturase 1 (SCD1)

Colorectal cancer (CRC) is one of the most commonly occurring cancers worldwide. Although several genetic alterations have been associated with CRC onset and progression, nowadays the reprogramming of cellular metabolism has been recognized as a fundamental step of the carcinogenic process. Intestinal tumor cells frequently display an aberrant activation of lipid metabolism. Indeed, to satisfy the growing needs of a continuous proliferation, cancer cells can either increase the uptake of exogenous lipids or upregulate the endogenous lipogenesis and cholesterol synthesis. Therefore, strategies aimed at limiting lipid accumulation are now under development in order to counteract malignancies. Two major players of lipids metabolism have been so far identified for their contribution to CRC development: the nuclear receptor Liver X Receptor (LXRs) and the enzyme Stearoyl-CoA Desaturase 1 (SCD1). Whereas LXR is mainly recognized for its role as a cholesterol sensor, finally promoting the loss of cellular cholesterol and whole-body homeostasis, SCD1 acts as the major regulator of new fatty acids, finely tuning the monounsaturated fatty acids (MUFA) to saturated fatty acids (SFA) ratio. Intriguingly, SCD1 is directly regulated by LXRs. Despite LXRs agonists have elicited great interest as a promising therapeutic target for cancer, LXR's ability to induce SCD1 and new fatty acids synthesis represent a major obstacle in the development of new effective treatments. Thus, further investigations are required to fully dissect the concomitant modulation of both players, to develop specific therapies aimed at blocking intestinal cancer cells proliferation, eventually counteracting CRC progression.

Targeting Lipid Peroxidation for Cancer Treatment

Cancer is one of the highest prevalent diseases in humans. The chances of surviving cancer and its prognosis are very dependent on the affected tissue, body location, and stage at which the disease is diagnosed. Researchers and pharmaceutical companies worldwide are pursuing many attempts to look for compounds to treat this malignancy. Most of the current strategies to fight cancer implicate the use of compounds acting on DNA damage checkpoints, non-receptor tyrosine kinases activities, regulators of the hedgehog signaling pathways, and metabolic adaptations placed in cancer. In the last decade, the finding of a lipid peroxidation increase linked to 15-lipoxygenases isoform 1 (15-LOX-1) activity stimulation has been found in specific successful treatments against cancer. This discovery contrasts with the production of other lipid oxidation signatures generated by stimulation of other lipoxygenases such as 5-LOX and 12-LOX, and cyclooxygenase (COX-2) activities, which have been suggested as cancer biomarkers and which inhibitors present anti-tumoral and antiproliferative activities. These findings support the previously proposed role of lipid hydroperoxides and their metabolites as cancer cell mediators. Depletion or promotion of lipid peroxidation is generally related to a specific production source associated with a cancer stage or tissue in which cancer originates. This review highlights the potential therapeutical use of chemical derivatives to stimulate or block specific cellular routes to generate lipid hydroperoxides to treat this disease.

Phospholipase A2 superfamily in cancer

Phospholipase A2 enzymes (PLA₂s) comprise a superfamily that is generally divided into six subfamilies known as cytosolic PLA₂s (cPLA₂s), calcium-independent PLA₂s (iPLA₂s), secreted PLA₂s (sPLA₂s), lysosomal PLA₂s, platelet-activating factor (PAF) acetylhydrolases, and adipose specific PLA₂s. Each subfamily consists of several isozymes that possess PLA₂ activity. The first three PLA₂ subfamilies play important roles in inflammation-related diseases and cancer. In this review, the roles of well-studied enzymes sPLA₂-IIA, cPLA₂α and iPLA₂β in carcinogenesis and cancer development were discussed. sPLA₂-IIA seems to play conflicting roles and can act as a tumor suppressor or a tumor promoter according to the cancer type, but cPLA₂α and iPLA₂β play protumorigenic role in most cancers. The mechanisms of PLA₂-mediated signal transduction and crosstalk between cancer cells and endothelial cells in the tumor microenvironment are described. Moreover, the mechanisms by which PLA₂s mediate lipid reprogramming and glycerophospholipid remodeling in cancer cells are illustrated. PLA₂s as the upstream regulators of the arachidonic acid cascade are generally high expressed and activated in various cancers. Therefore, they can be considered as potential pharmacological targets and biomarkers in cancer. The detailed information summarized in this review may aid in understanding the roles of PLA₂s in cancer, and provide new clues for the development of novel agents and strategies for tumor prevention and treatment.

Genetic Markers of the Host to Predict the Efficacy of Colorectal Cancer Targeted Therapy

The introduction of anti-EGFR (cetuximab and panitumumab) and antiangiogenic (bevacizumab, regorafeninb, ramucirumab, and aflibercept) agents in the therapeutic armamentarium of the metastatic colorectal cancer (CRC) has significantly improved the therapeutic efficacy and patients survival. However, despite the great improvements achieved in the patients life expectation, the high inter-individual heterogeneity in the response to the targeted agents still represent an issue for the management of advanced CRC patients. Even if the role of tumor genetic mutations as predictive markers of drug efficacy has been well-established, the contribution of the host genetic markers is still controversial. Promising results regard the germ-line immune-profile, inflammation and tumor microenvironment. Inherent variations in KRAS 3'UTR region as well as EGF/ EGFR genes were investigated as markers of cetuximab effectiveness. More recently interesting data in the field of anti- EGFR agents were generated also for germ-line variants in genes involved in inflammation (e.g. COX-2, LIFR, IGF1 signaling), immune system (e.g., FCGRs, IL-1RA), and other players of the RAS signaling, including the Hippo pathway related genes (e.g. Rassf, YAP, TAZ). Host genetic variants in VEGF-dependent (i.e., EGF, IGF-1, HIF1α, eNOS, iNOS) and -independent (i.e., EMT cascade, EGFL7) pathways, with specific attention on inflammation and immune system-related factors (e.g., IL-8, CXCR-1/2, CXCR4-CXCL12 axis, TLRs, GADD34, PPP1R15A, ANXA11, MKNK1), were investigated as predictive markers of bevacizumab outcome, generating some promising results. In this review, we aimed to summarize the most recent literature data regarding the potential role of common and rare inhered variants in predicting which CRC patients will benefit more from a specifically targeted drug administration.

iRhom2: An Emerging Adaptor Regulating Immunity and Disease

The rhomboid family are evolutionary conserved intramembrane proteases. Their inactive members, iRhom in Drosophila melanogaster and iRhom1 and iRhom2 in mammals, lack the catalytic center and are hence labelled “inactive” rhomboid family members. In mammals, both iRhoms are involved in maturation and trafficking of the ubiquitous transmembrane protease a disintegrin and metalloprotease (ADAM) 17, which through cleaving many biologically active molecules has a critical role in tumor necrosis factor alpha (TNFα), epidermal growth factor receptor (EGFR), interleukin-6 (IL-6) and Notch signaling. Accordingly, with iRhom2 having a profound influence on ADAM17 activation and substrate specificity it regulates these signaling pathways. Moreover, iRhom2 has a role in the innate immune response to both RNA and DNA viruses and in regulation of keratin subtype expression in wound healing and cancer. Here we review the role of iRhom2 in immunity and disease, both dependent and independent of its regulation of ADAM17.

Targeting cyclooxygenase by indomethacin decelerates progression of acute lymphoblastic leukemia in a xenograft model

Acute lymphoblastic leukemia (ALL) develops in the bone marrow in the vicinity of stromal cells known to promote tumor development and treatment resistance. We previously showed that the cyclooxygenase (COX) inhibitor indomethacin prevents the ability of stromal cells to diminish p53-mediated killing of cocultured ALL cells in vitro, possibly by blocking the production of prostaglandin E2 (PGE2). Here, we propose that PGE2 released by bone marrow stromal cells might be a target for improved treatment of pediatric ALL. We used a xenograft model of human primary ALL cells in nonobese diabetic-scid IL2rγnull mice to show that indomethacin delivered in the drinking water delayed the progression of ALL in vivo. The progression was monitored by noninvasive in vivo imaging of the engrafted leukemic cells, as well as by analyses of CD19+CD10+ leukemic blasts present in spleen or bone marrow at the termination of the experiments. The indomethacin treatment increased the level of p53 in the leukemic cells, implying that COX inhibition might reduce progression of ALL by attenuating protective paracrine PGE2 signaling from bone marrow stroma to leukemic cells.

EpCAM-Targeted 3WJ RNA Nanoparticle Harboring Delta-5-Desaturase siRNA Inhibited Lung Tumor Formation via DGLA Peroxidation

Knocking down delta-5-desaturase (D5D) expression by D5D small interfering RNA (siRNA) has been reported that could redirect the cyclooxygenase-2 (COX-2)-catalyzed dihomo-γ-linolenic acid (DGLA) peroxidation from producing prostaglandin E2 to 8-hydroxyoctanoic acid (8-HOA), resulting in the inhibition of colon and pancreatic cancers. However, the effect of D5D siRNA on lung cancer is still unknown. In this study, by incorporating epithelial cell adhesion molecule (EpCAM) aptamer and validated D5D siRNA into the innovative three-way junction (3WJ) RNA nanoparticle, target-specific accumulation and D5D knockdown were achieved in the lung cancer cell and mouse models. By promoting the 8-HOA formation from the COX-2-catalyzed DGLA peroxidation, the 3WJ-EpCAM-D5D siRNA nanoparticle inhibited lung cancer growth in vivo and in vitro. As a potential histone deacetylases inhibitor, 8-HOA subsequently inhibited cancer proliferation and induced apoptosis via suppressing YAP1/TAZ nuclear translocation and expression. Therefore, this 3WJ-RNA nanoparticle could improve the targeting and effectiveness of D5D siRNA in lung cancer therapy.

Hyaluronic acid promotes Lgr5+ stem cell proliferation and crypt fission through TLR4 and PGE2 transactivation of EGFR

Hyaluronic acid (HA), a glycosaminoglycan in the extracellular matrix, binds to CD44 and Toll-like receptor 4 (TLR4). We previously demonstrated that both CD44 and TLR4, but predominately TLR4, mediated HA stimulation of Lgr5⁺ stem cell proliferation, crypt fission, and intestinal growth in postnatal mice. Here we address the questions of which cell type expresses the relevant TLR4 in driving intestinal growth and what are the downstream events from TLR4 activation. Studies were done in 14-day-old mice: wild type (WT), mice deficient in cyclooxygenase 2 (COX2), mice deficient in myeloid cell TLR4, and mice deficient in epithelial cell epidermal growth factor receptor (EGFR). Biological end points included crypt fission and Lgr5 cell proliferation. In WT mice, treatment with NS-398 (a COX2 inhibitor), clodronate (a macrophage-depleting agent), or tyrphostin (an EGFR inhibitor) resulted in 30% reductions in crypt fission and Lgr5⁺ stem cell proliferation compared with control mice. Mice deficient in COX2 or myeloid TLR4 or epithelial cell EGFR all had 30% reductions in crypt fission and Lgr5⁺ stem cell proliferation compared with WT mice. Administration of dimethyl PGE₂, a stable PGE₂ analog, increased crypt fission and Lgr5⁺ stem cell proliferation. Administration of dimethyl PGE₂ reversed the effects of NS-398, clodronate, COX2 deficiency, and myeloid TLR4 deficiency but had no effect on mice treated with tyrphostin or mice deficient in epithelial cell EGFR. We conclude that, in postnatal mice, ~30% of intestinal growth as manifested by crypt fission and Lgr5⁺ stem cell proliferation is driven by a novel pathway: Extracellular HA binds TLR4 on pericryptal macrophages, inducing the production of PGE₂ through COX2. PGE₂ transactivates EGFR in Lgr5⁺ epithelial stem cells, resulting in Lgr5⁺ stem cell proliferation and crypt fission.NEW & NOTEWORTHY This study, in newborn mice, describes a novel molecular pathway regulating Lgr5⁺ epithelial stem cell proliferation and normal intestinal elongation, as assessed by crypt fission. In this pathway, endogenous extracellular hyaluronic acid binds to Toll-like receptor 4 on pericryptal macrophages releasing PGE₂ which binds to epidermal growth factor receptor on Lgr5⁺ stem cells resulting in proliferation. Lgr5⁺ stem cell proliferation leads to crypt fission and intestinal elongation. The demonstration that normal growth requires microbial-independent Toll-like receptor activation is novel.

Increasing the Hindgut Carbohydrate/Protein Ratio by Cecal Infusion of Corn Starch or Casein Hydrolysate Drives Gut Microbiota-Related Bile Acid Metabolism To Stimulate Colonic Barrier Function

Dietary high protein and low carbohydrate levels compromise colonic microbiota and bile acid metabolism, which underlies a detrimental gut environment. However, it remains unclear if the diet-induced changes in colonic health are due to a change in hindgut nutrient availability and what key intermediates link the microbe-epithelium dialogue. To specifically alter the hindgut nutrient substrate availability, here we used a cecally cannulated pig model to infuse corn starch and casein hydrolysate directly into the cecum to generate a stepwise change of carbohydrate/nitrogenous compound (C/N) ratio. Pigs were cecally infused daily with either saline (Control), corn starch (Starch), or casein hydrolysate (Casein) (n = 8 per group), respectively, for 19 days. After infusion, C/N ratios in colonic digesta were 16.33, 12.56, and 8.54 for the starch, control, and casein groups, respectively (P < 0.05). Relative to the control group, casein infusion showed greater abundance of the bacteria (Eubacterium) capable of bile acid 7α-dehydroxylation (baiJ), higher levels of expression of bacterial genes encoding the baiJ enzyme, and higher levels of secondary bile acid (deoxycholic acid [DCA] and lithocholic acid [LCA]), while the starch infusion showed the opposite effect. Correspondingly, casein infusion downregulated expression of genes encoding tight junction proteins (ZO-1 and OCLD) and upregulated expression of genes encoding epidermal growth factor receptor (EGFR). The ratio of C/N was linearly related with the concentrations of DCA and LCA and gene expression levels of ZO-1, occludin, and EGFR. Caco-2 cell experiments further showed that DCA and LCA downregulated expression of genes involved in barrier function (ZO-1 and OCLD) and upregulated the gene expression of EGFR and Src. Inhibition of EGFR and Src could abolish DCA- and LCA-induced downregulation of ZO-1, indicating that DCA and LCA impair gut barrier function via enhancing the EGFR-Src pathway. These results suggest that the ratio of C/N in the large intestine is an important determinant of microbial metabolism and gut barrier function in the colon. The findings provide evidence that microbe-related secondary bile acid metabolism may mediate the interplay between microbes and gut barrier function.

IMPORTANCE High-fiber or high-protein diets could alter gut microbiota and health in the large intestine, but factors involved in the effects remain unclear. The present study for the first time demonstrates that the starch- and casein-induced C/N ratio in the hindgut is an important factor. Using the cannulated pig model, we found that the distinct C/N ratio induced by cecal infusion of corn starch or casein hydrolysate was linearly correlated with microbial metabolites (secondary bile acids) and tight junction proteins (ZO-1 and OCLD). Cell culture study further demonstrates that the gut microbial metabolites (DCA and LCA) could impair the intestinal barrier function via the EGFR-Src pathway. These suggest that DCA and LCA were key metabolites mediating microbe-epithelium dialogue when the hindgut C/N ratios were altered by cecal infusion of corn starch or casein hydrolysate. These findings provide new insight into the impact of C/N ratio in the large intestine on colonic health and provide a new framework for therapeutic strategy in gut health through targeted manipulation of hindgut microbiota by increasing the carbohydrate level in the large intestine.

Functional Gene Clusters in Global Pathogenesis of Clear Cell Carcinoma of the Ovary Discovered by Integrated Analysis of Transcriptomes

Clear cell carcinoma of the ovary (ovarian clear cell carcinoma (OCCC)) is one epithelial ovarian carcinoma that is known to have a poor prognosis and a tendency for being refractory to treatment due to unclear pathogenesis. Published investigations of OCCC have mainly focused only on individual genes and lack of systematic integrated research to analyze the pathogenesis of OCCC in a genome-wide perspective. Thus, we conducted an integrated analysis using transcriptome datasets from a public domain database to determine genes that may be implicated in the pathogenesis involved in OCCC carcinogenesis. We used the data obtained from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) DataSets. We found six interactive functional gene clusters in the pathogenesis network of OCCC, including ribosomal protein, eukaryotic translation initiation factors, lactate, prostaglandin, proteasome, and insulin-like growth factor. This finding from our integrated analysis affords us a global understanding of the interactive network of OCCC pathogenesis.

Regulation of Src Family Kinases during Colorectal Cancer Development and Its Clinical Implications

Src family kinases (SFKs) are non-receptor kinases that play a critical role in the pathogenesis of colorectal cancer (CRC). The expression and activity of SFKs are upregulated in patients with CRC. Activation of SFKs promotes CRC cell proliferation, metastases to other organs and chemoresistance, as well as the formation of cancer stem cells (CSCs). The enhanced expression level of Src is associated with decreased survival in patients with CRC. Src-mediated regulation of CRC progression involves various membrane receptors, modulators, and suppressors, which regulate Src activation and its downstream targets through various mechanisms. This review provides an overview of the current understanding of the correlations between Src and CRC progression, with a special focus on cancer cell proliferation, invasion, metastasis and chemoresistance, and formation of CSCs. Additionally, this review discusses preclinical and clinical strategies to improve the therapeutic efficacy of drugs targeting Src for treating patients with CRC.

Cyclooxygenase 2-Regulated Genes an Alternative Avenue to the Development of New Therapeutic Drugs for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and recurrent types of cancer, with high mortality rates. Several clinical trials and meta-analyses have determined that the use of pharmacological inhibitors of cyclooxygenase 2 (COX-2), the enzyme that catalyses the rate-limiting step in the synthesis of prostaglandins (PG) from arachidonic acid, can reduce the incidence of CRC as well as the risk of recurrence of this disease, when used together with commonly used chemotherapeutic agents. These observations suggest that inhibition of COX-2 may be useful in the treatment of CRC, although the current drugs targeting COX-2 are not widely used since they increase the risk of health complications. To overcome this difficulty, a possibility is to identify genes regulated by COX-2 activity that could give an advantage to the cells to form tumors and/or metastasize. The modulation of those genes as effectors of COX-2 may cancel the beneficial effects of COX-2 in tumor transformation and metastasis. A review of the available databases and literature and our own data have identified some interesting molecules induced by prostaglandins or COX-2 that have been also described to play a role in colon cancer, being thus potential pharmacological targets in colon cancer. Among those mPGES-1, DUSP4, and 10, Programmed cell death 4, Trop2, and many from the TGFβ and p53 pathways have been identified as genes upregulated in response to COX-2 overexpression or PGs in colon carcinoma lines and overexpressed in colon tumor tissue. Here, we review the available evidence of the potential roles of those molecules in colon cancer in the context of PG/COX signaling pathways that could be critical mediators of some of the tumor growth and metastasis advantage induced by COX-2. At the end, this may allow defining new therapeutic targets/drugs against CRC that could act specifically against tumor cells and would be effective in the prevention and treatment of CRC, lacking the unwanted side effects of COX-2 pharmacological inhibitors, providing alternative approaches in colon cancer.

Bisphenol A induces focal adhesions assembly and activation of FAK, Src and ERK2 via GPER in MDA-MB-231 breast cancer cells

Bisphenol A (BPA) is an industrial synthetic chemical used in the production of polycarbonate plastics and epoxy resins. Human exposition to BPA is primarily through eating food, and drinking liquids, because BPA can leach from polycarbonate plastic containers, beverage cans and epoxy resins. BPA induces proliferation and migration in human breast cancer cells. The G protein-coupled estrogen receptor (GPER) is a G protein-coupled receptor coupled with Gs proteins that is activated by estrogen and estrogenic compounds and it is the receptor for BPA. However, the signal transduction pathways that mediate migration via BPA/GPER in triple negative breast cancer (TNBC) cells has not been studied in detail. Here, we demonstrate that BPA induces an increase of GPER expression and activation of FAK, Src and ERK2, and an increase of focal adhesion assembly via GPER in TNBC MDA-MB-231 cells. Moreover, BPA induces FAK and ERK2 activation, focal adhesion assembly and migration via epidermal growth factor receptor (EGFR) transactivation. Collectively our data showed that BPA via GPER and/or EGFR transactivation induces activation of signal transduction pathways that mediate migration in TNBC MDA-MB-231 cells.

miR-370-3p Alleviates Ulcerative Colitis-Related Colorectal Cancer in Mice Through Inhibiting the Inflammatory Response and Epithelial-Mesenchymal Transition

Introduction

Ulcerative colitis (UC) is a chronic and inflammatory bowel disease. UC-associated colorectal cancer (UC-CRC) is one of the most severe complications of long-standing UC. In the present study, we explored the effects of miR-370-3p on UC-CRC in vivo and investigated its underlying mechanisms in vivo and in vitro.

Methods

Azoxymethane (AOM) and dextran sodium sulfate (DSS) were used to induce UC-CRC in C57BL/6 mice. AOM/DSS-induced mice were treated with 5×10⁸ pfu miR-370-3p overexpressing-adenovirus via tail-vein injection every two weeks.

Results

We found that miR-370-3p significantly improved the body weights and survival rates and inhibited the tumorigenesis of UC-CRC in AOM/DSS mice. Mechanically, miR-370-3p inhibited AOM/DSS-induced inflammatory response by decreasing tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) through targeting toll-like receptor 4 (TLR4), as demonstrated by down-regulation of TLR4, cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and phosphorylated epidermal growth factor receptor (pEGFR). miR-370-3p decreased the expression of tumor-associated proteins, including p53, β-catenin, and ki67 in AOM/DSS-treated mice. Additionally, miR-370-3p remarkably inhibited epithelial-mesenchymal transition (EMT) via increasing E-cadherin expression and reducing N-cadherin and Vimentin expression in vivo. Further studies showed that miR-370-3p repressed proliferation and EMT of colon cancer cells in vitro. Moreover, we proved that miR-370-3p decreased the expression of tumor-associated proteins and reversed EMT by regulating β-catenin in colon cancer cells.

Conclusion

Taken together, miR-370-3p alleviated UC-CRC by inhibiting the inflammatory response and EMT in mice, which suggested miR-370-3p as a novel potential target for UC-CRC therapy.

α-Ketoglutarate attenuates Wnt signaling and drives differentiation in colorectal cancer

Genetic-driven deregulation of the Wnt pathway is crucial but not sufficient for colorectal cancer (CRC) tumourigenesis. Here, we show that environmental glutamine restriction further augments Wnt signaling in APC mutant intestinal organoids to promote stemness and leads to adenocarcinoma formation in vivo via decreasing intracellular alpha-ketoglutarate (aKG) levels. aKG supplementation is sufficient to rescue low-glutamine induced stemness and Wnt hyperactivation. Mechanistically, we found that aKG promotes hypomethylation of DNA and histone H3K4me3, leading to an upregulation of differentiation-associated genes and downregulation of Wnt target genes, respectively. Using CRC patient-derived organoids and several in vivo CRC tumour models, we show that aKG supplementation suppresses Wnt signaling and promotes cellular differentiation, thereby significantly restricting tumour growth and extending survival. Together, our results reveal how metabolic microenvironment impacts Wnt signaling and identify aKG as a potent antineoplastic metabolite for potential differentiation therapy for CRC patients.

Interaction of epidermal growth factor with COX-2 products and peroxisome proliferator-activated receptor-γ system in experimental rat Barrett's esophagus

Mixed acidic-alkaline refluxate is a major pathogenic factor in chronic esophagitis progressing to Barrett's esophagus (BE). We hypothesized that epidermal growth factor (EGF) can interact with COX-2 and peroxisome proliferator-activated receptor-γ (PPARγ) in rats surgically prepared with esophagogastroduodenal anastomosis (EGDA) with healthy or removed salivary glands to deplete salivary EGF. EGDA rats were treated with 1) vehicle, 2) EGF or PPARγ agonist pioglitazone with or without EGFR kinase inhibitor tyrphostin A46, EGF or PPARγ antagonist GW9662 respectively, 3) ranitidine or pantoprazole, and 4) the selective COX-2 inhibitor celecoxib combined with pioglitazone. At 3 mo, the esophageal damage and the esophageal blood flow (EBF) were determined, the mucosal expression of EGF, EGFR, COX-2, TNFα, and PPARγ mRNA and phospho-EGFR/EGFR protein was analyzed. All EGDA rats developed chronic esophagitis, esophageal ulcerations, and intestinal metaplasia followed by a fall in the EBF, an increase in the plasma of IL-1β, TNFα, and mucosal PGE₂ content, the overexpression of COX-2-, and EGF-EGFR mRNAs, and proteins, and these effects were aggravated by EGF and attenuated by pioglitazone. The rise in EGF and COX-2 mRNA was inhibited by pioglitazone but reversed by pioglitazone cotreated with GW9662. We conclude that 1) EGF can interact with PG/COX-2 and the PPARγ system in the mechanism of chronic esophagitis; 2) the deleterious effect of EGF involves an impairment of EBF and the overexpression of COX-2 and EGFR, and 3) agonists of PPARγ and inhibitors of EGFR may be useful in the treatment of chronic esophagitis progressing to BE.NEW & NOTEWORTHY Rats with EGDA exhibited chronic esophagitis accompanied by a fall in EBF and an increase in mucosal expression of mRNAs for EGF, COX-2, and TNFα, and these effects were exacerbated by exogenous EGF and reduced by removal of a major source of endogenous EGF with salivectomy or concurrent treatment with tyrphostin A46 or pioglitazone combined with EGF. Beneficial effects of salivectomy in an experimental model of BE were counteracted by PPARγ antagonist, whereas selective COX-2 inhibitor celecoxib synergistically with pioglitazone reduced severity of esophageal damage and protected esophageal mucosa from reflux. We propose the cross talk among EGF/EGFR, PG/COX-2, and proinflammatory cytokines with PPARγ pathway in the mechanism of pathogenesis of chronic esophagitis progressing to BE and EAC.

Combination of Erlotinib and Naproxen Employing Pulsatile or Intermittent Dosing Profoundly Inhibits Urinary Bladder Cancers

Daily dosing of either NSAIDs or EGFR inhibitors has been shown to prevent bladder cancer development in a N-butyl-(4-hydroxybutyl)nitrosamine (OH-BBN)-induced rat model. However, these inhibitors cause gastrointestinal ulceration and acneiform rash, respectively, limiting their continuous use in a clinical prevention setting. We studied chemopreventive efficacy of pulsatile dosing of EGFR inhibitor erlotinib (42 mg/kg BW, once/week) combined with intermittent or continuous low doses of the NSAID naproxen (30 mg/kg BW/day, 3 weeks on/off or 128 ppm daily in diet) in the OH-BBN induced rat bladder cancer model. The interventions were started either at 1 or 4 weeks (early intervention) or 3 months (delayed intervention) after the last OH-BBN treatment, by which time the rats had developed microscopic bladder lesions. All combination regimens tested as early versus late intervention led to the reduction of the average bladder tumor weights (54%-82%; P < 0.01 to P < 0.0001), a decrease in tumor multiplicity (65%-85%; P < 0.01 to P < 0.0001), and a decrease in the number of rats with large palpable tumors (>200 mg; 83%-90%; P < 0.01 to P < 0.0001). Levels of signal transduction markers, Ki-67, cyclin D1, IL1β, pSTAT3, and pERK, were significantly (P < 0.05 to P < 0.001) reduced in the treated tumors, demonstrating their potential utility as predictive markers for efficacy. These findings demonstrate that significant chemopreventive efficacy could be achieved with alternative intervention regimens designed to reduce the toxicity of agents, and that starting erlotinib and/or naproxen treatments at the time microscopic tumors were present still conferred the efficacy.