Significance of cyclooxygenase-2 in oncogenesis

Abstract

The cyclooxygenase-2 (COX-2) enzyme catalyses the first stage of biosynthesis of prostanoids, proteins that are implicated in various physiological and pathological processes in humans and animals. The expression of COX-2 increases significantly during pathological processes accompanied by inflammation, pain and fever. Overexpression of COX-2 was determined in tumour tissues, which suggests that this enzyme participates in oncogenesis. In this paper the topics discussed are mechanisms regulating COX-2 expression, COX isoforms, their role in the body and the oncogenic mechanisms triggered by the overexpression of COX-2, including inhibition of apoptosis, intensification of neoangiogenesis, increased metastatic capacity, and weakening of the immune system. The significance of and the mechanisms by which COX-2 participates in oncogenesis have been studied intensively in recent years. The results are highly promising, and they expand our understanding of the complex processes and changes at the molecular, cellular and tissue level that promote oncogenesis and cancer progression. Notwithstanding the knowledge already gleaned, many processes and mechanisms have not yet been elucidated in human medicine and, in particular, in veterinary medicine. Further research is required to develop effective tumour diagnostic methods and treatment procedures for humans and animals.

From Conventional to Precision Therapy in Canine Mammary Cancer: A Comprehensive Review

“…Cyclooxygenases (COX) are a group of enzymes that catalyzes the conversion of arachidonic acid to prostanoids (prostaglandins, prostacyclins, and thromboxanes). In humans and animals, COX exist in three isoforms: COX-1, constitutively found in most cells, in charge of maintaining homeostasis, protection of the gastric mucosa, and regulation of platelet aggregation and renal blood flow; cyclooxygenase-2 (COX-2), an inducible isoform that is detected in neoplastic and normal cells induced through several stimuli (e.g., mitogens, growth factors, hormones, and pro-inflammatory cytokines); and COX-3, which is expressed mainly in the central nervous system and the aortic wall ( 217 , 218 ).…”

Cyclooxygenase-2 as a biomarker with diagnostic, therapeutic, prognostic, and predictive relevance in small animal oncology

“…COX-2 overexpression causes the cells' phenotype to change from benign to malignant, which is connected with disruption of their growth and proliferation and an increase in cells' ability to evade apoptosis and immune response, promote new blood vessels, and raise their invasive potential (50). More details of the function of COX-2 in the organism and the significance of COX-2 in oncogenesis were presented in our previous paper (57).…”

Efeito modulador do Previcox® sobre a ação carcinogênica da doxorrubicina por meio do teste de tumores epiteliais (ETT) em Drosophila melanogaster

“…No que se refere à angiogênese, a expressão da COX-2, que catalisa a produção de prostaglandinas, está altamente correlacionada com a intensidade da angiogênese e o desenvolvimento do tumor (JAIN et al, 2008). Estudos realizados in vivo e in vitro demonstraram que um aumento na expressão de COX-2 em tumores contribui para a neovascularização por estimular a síntese e atividade de fatores pró-angiogênicos e exerce uma influência direta nas células endoteliais pelos produtos das reações com COX-2: PGE2, PGI2 e TXA2 (SZWEDA et al, 2019;YUAN et al, 2005). Foi descoberto que os inibidores da COX-2 suprimem a neoangiogênese na progressão do câncer e proporcionam efeitos terapêuticos positivos (SALVADO et al, 2012).…”