Radiation induces upregulation of cyclooxygenase-2 (COX-2) protein in PC-3 cells

Steinauer, Kirsten K; Gibbs, Iris C.; Ning, Shoucheng; French, John N.; Armstrong, Jeff; Knox, Susan J.

doi:10.1016/s0360-3016(00)00671-4

Cited by 111 publications

(70 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found also that the large majority of negative tumor biopsies expressed COX-2 protein after radiotherapy and that a subset of positive tumor biopsies has an increased expression. This finding support the fact that, at least in a subgroup of rectal cancer, COX-2 is upregulated by radiation as already reported in some cancer cell lines [37]. However, this is in partial contradiction with a recent study that compared COX-2 expression in pretherapeutical rectal carcinoma biopsies and posttherapeutical surgical specimen and which found that COX-2 expression is present in nearly all pretherapeutical biopsies although there is an increase of the intensity of COX-2 expression in one third of posttherapeutical rectal cancer [45].…”

Section: Discussionsupporting

confidence: 78%

The role of COX-2 in rectal cancer treated with preoperative radiotherapy

et al. 2008

View full text Add to dashboard Cite

Radiotherapy is one of the principal modalities of rectal cancer treatment, and the ability to predict radio resistance could potentially improve survival through a targeted treatment approach. Cyclooxygenase-2 (COX-2) may protect against damage by irradiation that would justify the use of COX-2 inhibitors. The purpose of this study was to investigate the potential role of COX-2 in tumor response and outcome of patients with rectal cancer treated preoperatively with radiotherapy. Using immunohistochemistry, we examined COX-2 expression in 88 surgical specimens of rectal cancer treated preoperatively and in 26 pretherapeutic biopsies. We tested whether COX-2 expression was correlated with clinico-pathologic parameters and with survival and local recurrence. COX-2 was expressed in 50% of the pretherapeutic tumor biopsies and in 88.6% of post-irradiated surgical samples. COX-2 expression was correlated only with enhanced tumor inflammation (p=0.03) and with tumor volume exceeding 30 cc (p=0.05). COX-2 was not significantly correlated with patient survival, but none of the patients with COX-2 negative tumors did recur locally, whereas 80% of patients with local recurrences have COX-2 positive tumors. We conclude that COX-2 expression is overexpressed in the majority of rectal cancers treated with radiotherapy and likely plays a role in local relapse.

show abstract

Section: Discussionsupporting

confidence: 78%

The role of COX-2 in rectal cancer treated with preoperative radiotherapy

et al. 2008

View full text Add to dashboard Cite

show abstract

“…28 Steinauer et al 29 observed a dosedependent increase in COX-2 following irradiation and, in the present study, increased COX-2 protein expression was seen in irradiated HeLa cells. Increased COX-2 expression after radiotherapy could lead to radioresistance, tumour recurrence and metastasis.…”

Section: Cox-2-and Vegf-c-dependent Celecoxib Radiosensitivitysupporting

confidence: 63%

Celecoxib Radiosensitizes the Human Cervical Cancer HeLa Cell Line via a Mechanism Dependent on Reduced Cyclo-Oxygenase-2 and Vascular Endothelial Growth Factor C Expression

Wang

Tian

et al. 2012

J Int Med Res

View full text Add to dashboard Cite

OBJECTIVE:The effects of celecoxib, a selective cyclo-oxygenase-2 (COX-2) inhibitor, on HeLa cervical cancer cell growth and radiosensitivity were investigated. METHODS: Cytotoxicity was quantified using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay and effects on radiosensitivity were assessed using the lethal dose, quasithreshold dose, fraction surviving after 2 Gy irradiation and the radiosensitization ratio (SER, based on average lethal dose) determined using a single-hit multitarget model. RESULTS: Celecoxib inhibited HeLa cell proliferation in a concentrationand time-dependent

show abstract

“…Animal models have shown that COX-2 inhibition will improve the response to radiotherapy without markedly affecting normal tissue radiation response (25---26). Radiation of cells in vitro have also shown to increase COX-2 expression and its enzymatic product, prostaglandin E2 (PGE2) (27). Additionally, a Phase III randomized trial in familial adenomatous polyposis patients showed that 6 months of Celecoxib versus placebo significantly diminished the size and number of polyps (28).…”

Section: Introductionmentioning

confidence: 99%