The present study was undertaken to evaluate two such components of the inflammatory milieu, tumor-associated tissue eosinophilia (TATE) as well as Cyclo-oxygenase-2 (COX-2) gene expression, quantitatively in oral squamous cell carcinoma (OSCC) patients in relation to treatment outcomes and patterns of recurrence.
There was an elevated expression of the immunosuppressive genes PTGS2 (encoding COX-2) and CD274 (encoding PD-L1) in human and murine claudin-low tumors.
Therefore, it was hypothesized that tumor EGFR mutation status may influence the effectiveness of simultaneous EGFR and COX-2 inhibition in patients with NSCLC.
Our study investigated the impact of COX2 genotypes on early breast cancer events and treatment response in relation to tumor ER status and body constitution.
Furthermore, overexpression of COX-2 protein was observed in association with homozygosity in several polymorphic sites within COX-2 gene (promoter region sites -1186 T/T and -765 G/G, intron 5 IVS5-275 T/T, and exon 10 Ex10+837 T>C), indicating their role in development of these tumors.
In Ptch1(+/-) mice, genetic deletion of COX1 or COX2 robustly decreased (75%; P < 0.05) microscopic BCC tumor burden, but pharmacologic inhibition with celecoxib reduced microscopic BCCs less efficaciously (35%; P < 0.05).
The use of Cox-2 inhibitors to decrease function of MDR1 may enhance accumulation of chemotherapy agents and decrease resistance of tumors to chemotherapeutic drugs.
These in vitro and in vivo results suggest that selective COX-2 inhibitors enhance the effect of radiation on tumors that express COX-2 but not on COX-2-lacking tumors.
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.
Immunohistochemical and Western blot analyses of tumor tissue showed that the suppression of pancreatic cancer growth correlated with inhibition of proliferation index marker (Ki-67), COX-2, MMP-9, NF-κB and VEGF.
The co-expression of PTGS2 gene and M2 markers in human thyroid carcinoma highlights the possibility to counteract tumor growth through COX-2 inhibition.
Our study documents that PTGS2/COX-2 is part of a cyclic hypoxia gene signature and largely accounts for the unique phenotype of endothelial and tumor cells exposed to fluctuations in pO(2), thereby offering new perspectives for the clustering of tumors expressing COX-2 together with other cyclic hypoxia-responsive genes.
Although smokers tended to have more Cox 2-positive tumors than nonsmokers (29 of 91 tumors in the smokers [32%] vs. 1 of 10 tumors in the nonsmokers [10%]; P = 0.15), there was no statistically significant relation found between Cox 1 or Cox 2 expression and smoking status or prognostically significant clinicopathologic features.
Although the benefits of COX-2 inhibition may eventually outweigh the associated cardiovascular risks, there are a number of alternative targets for inhibiting the formation of PGE2 in human tumors that may prove less harmful to the patient.
In the present study, we hypothesized that endoplasmic reticulum stress (ERS) is involved in the up-regulation of VEGF expression induced by celecoxib in colorectal cancer HCT116 cells and that ERS is a major mechanism by which celecoxib triggers tumor cell death in a COX-2-independent manner.
Taken together these data support efforts to initiate clinical studies to investigate the effect of Cox-2 inhibitors as chemotherapeutic agents and as adjuvant treatment modalities against gastric neoplasias.
Additionally, treatment with COX-2-selective inhibitors reduces polyp burden in animal models of intestinal neoplasia and in humans with familial adenomatous polyposis (FAP).
In the present study, we show that tumour promoter PMA-mediated induction of genes that are significantly associated with inflammation, tumour growth and metastasis, such as COX-2 (cyclo-oxygenase 2) and VEGF (vascular endothelial growth factor), is inhibited by PPARalpha ligands in the human colorectal carcinoma cell line SW620.
These data clearly demonstrate that the transcriptional control afforded by the cox-2 promoter is tumor-specific and is able to mitigate associated toxicity in normal tissue while maintaining therapeutic efficacy in the context of an ovarian cancer molecular chemotherapeutic approach.
Moreover, cotransfection of COX-2 and mPGES-1 into HEK293 cells resulted in cellular transformation manifested by colony formation in soft agar culture and tumor formation when implanted subcutaneously into nude mice. cDNA array analyses revealed that this mPGES-1-directed cellular transformation was accompanied by changes in the expression of a variety of genes related to proliferation, morphology, adhesion, and the cell cycle.