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Biomedical subjects

P Eschwège

Publications and source records attributed to P Eschwège.

At least 19 recordsLinked to original sources

A histopathologic investigation of PGE(2) pathways as predictors of proliferation and invasion in urothelial carcinomas of the bladder.

INTRODUCTION AND OBJECTIVES: The pattern of arachidonate acid (AA) transformation in tumor cells has been shown to play a role in determining tumor cell invasiveness. AA is released from membrane phospholipids by cPLA(2). Then it is metabolized into prostaglandins and PGE(2) especially via cyclooxygenase pathways. PGE(2) production seems to be necessary for rendering the cells invasive. We aimed to characterize cPLA(2), cyclooxygenase 2 (COX2) and prostaglandine E synthase (PGES) expression in human transitional carcinoma (TCC) of the urinary bladder and correlate with the Ki-67 proliferating marker. METHODS: Formalin-fixed human TCC tissues (n=54) obtained from TURB or cystectomies were evaluated for cPLA(2), COX2, PGES and Ki-67 expression using specific antibodies. There were 6 CIS, 9 pTaG1, 9 pTaG3, 10 pT1G3 and 10 pT2G3. 10 normal bladder tissues were also evaluated. Control slides were incubated without primary antibodies and treated in a similar way. RESULTS: cPLA(2), COX2 and PGES were not expressed in the 10 normal tissues. In the same normal tissues, Ki-67 expression was observed only in 1% of the cells. However, cPLA(2) was expressed in 1/6 CIS, 1/9 pTaG1, 3/9 pTaG3, 6/10 pT1G3 and 2/10 pT2G3. COX2 was expressed in 0/6 CIS, 0/10 pTaG1, 2/9 pTaG3, 3/10 pT1G3 and 1/10 pT2G3. PGES was expressed in 4/6 CIS, 0/9 pTaG1, 4/9 pTaG3, 2/10 pT1G3 and 5/10 pT2G3. Ki-67 expression was 39.5% for CIS, 6.5% in pTaG1, 37% in pTaG3, 34.5% in pT1G3 and 55% in pT2G3. If we consider it a positive result when at least one enzyme was expressed, there were 5/6 CIS positive, 1/9 pTaG1 positive, 9/9 pTaG3 positive, 10/10 pT1G3 positive and 10/10 pT2G3 positive. Also the Ki-67 is more often expressed in cells with high grade tumor. CONCLUSIONS: These results suggest that (i). not only COX2 is involved in the tumorogenesis of the TCC but also cPLA(2) and PGES, (ii). there is relationship between the AA metabolic PGE(2) pathway expression and the aggressiveness of the TCC of the urinary bladder.

Aged↗

[Arachidonic acid and prostaglandins, inflammation and oncology].

CYCLOOXYGENASE PATHWAY: Among the 3 metabolic pathways leading to oxidation of arachidonic acid, the cyclooxygenase (COX) pathway produces prostaglandin G2 that is rapidly transformed into prostaglandin H2. PROSTAGLANDINS: Prostaglandins are inflammation mediators that are strongly implicated in tumorgenesis. They participate in tumor initiation, promotion and growth. INFLAMMATION AND EPITHELIAL CANCER: Chronic inflammation is a risk factor for epithelial cancer. It induces prostaglandin synthesis via activation of COX-2. There is a cause and effect relationship between chronic inflammation and carcinogeneis via COX-2 expression. It has been demonstrated that COX-2 favors tumor invasion and inhibits apoptosis. Tumor growth is favored by PGE2-induced reduction in immunity; COX-2 inhibitors reinforce the immune response. Finally COX-2 is expressed in tumor neovessels and plays a role in angiogenesis.

Arachidonic Acid↗

[Cyclooxygenases].

TWO ISOFORMS: There are two isoforms of cyclooxygenase (COX) with similar structure and metabolic activity. COX-1 is a constitutional enzyme. COX-2 is an inductible form. CYCLOOXYGENASE-1: COX-1 is present in most tissues, particularly in the kidney, the digestive tract mucosa, platelets, brain, liver and spleen. CYCLOOXYGENASE-2: COX-2 expression can be induced by an inflammatory process. Implicated in the development of certain cancers, COX-2 is expressed in numerous tumor cell lines and in most epithelial carcinomas. COX-2 favors tumor invasion and inhibits apoptosis. When it is absent, tumor growth is slower or stopped.

Apoptosis↗

[Cyclooxygenase inhibitors].

DISTINCT EFFECTS: Since the discovery of the two isoforms of COX, the therapeutic effects of nonsteroidal antiinflammatory drugs (NSAID) can be distinguished from their adverse effects linked to the inhibition of the constitutional form via selective inhibition of the inducible form. Non-selective NSAID that inhibit both COX isoforms are difficult to use for long-term regimens. NSAID AND CANCER PREVENTION: Epidemiology studies and animal and in vitro studies have demonstrated that regular use of NSAID reduced the incidence of colorectal cancer and certain precancer lesions. PROMISING PERSPECTIVES: COX-2 specific inhibitors, for example cerecoxib or rofecoxib, are potentially interesting for human therapy for chemoprevention of epithelial cancer or as medical treatment, alone or in combination with other anticancer treatments.

Animals↗

Abnormal E-cadherin expression and prostate cell blood dissemination as markers of biological recurrence in cancer.

Until now, no molecular parameter has been available for predicting the metastatic potential of prostate tumours, which leaves their outcome uncertain despite an apparent benign histology or early stage. Abnormal expression of adhesion molecules, such as E-cadherin, can be contributing factors for increased invasiveness and metastatic potential. Histological analysis for E-cadherin expression was carried out on paraffin-embedded tumour tissues. Tumour metastatic potential was indirectly evaluated by detecting circulating prostate cells (CPC), using reverse transciptase-polymerase chain reaction (RT-PCR) and prostate-specific membrane antigen (PSMA) as a target. Patients were followed-up for a median of 14 months (range 10--19 months) after surgery with serum prostate-specific antigen (PSA) level measurement. Interestingly, 23 of 44 localised tumours exhibited aberrant E-cadherin expression. Prior to primary surgery, PSMA RT-PCR detected the spread of prostate cells to the blood in 24 patients. Statistical analysis showed that abnormal E-cadherin expression in the tumours was the only variable that was independently correlated with prostate cell dissemination in the blood (P<0.0001). In logistic regression analysis, abnormal E-cadherin expression was a significant independent predictor for a later biological relapse. This impaired adhesion status was clearly correlated with a haematogenous spread of the primary tumour cells. It could therefore be an objective way to restrict the indications for radical surgery to patients not presenting with this feature.

Adult↗

Blood-borne RT-PCR assay for prostasin- specific transcripts to identify circulating prostate cells in cancer patients.

OBJECTIVE: The aim of this study was to establish the specific detection of prostasin-expressing prostate cells in the blood of patients with prostate cancer. PATIENTS AND METHODS: A prostasin-specific RT-PCR assay was developed and optimized using limiting dilutions of cell line LNCaP mixed with normal blood specimens. Then, it was used to examine peripheral blood samples from 96 patients with prostate cancer (localized carcinoma, n = 69, metastatic, n = 27). Specificity was assessed by examination of 86 negative controls (healthy individuals, n = 47, benign prostate hyperplasia, n = 17, nonprostate cancer patients, n = 22). RESULTS: All 86 control samples failed to amplify the specific 546-bp prostasin PCR products. Blood samples from 35 out of 96 (36%) prostate cancer patients were found positive. In metastatic patients, 63% (17/27) scored positive whereas in localized adenocarcinoma prostasin primers detected prostate cells in 26% (18/69). CONCLUSION: Our results that approximately 30% of patients with localized prostate cancer scored positive for prostasin-specific RT-PCR confirm that the hematogenous spillage of prostate cells is an early event in the natural history of prostate cancer. As none of our negative controls were found positive, we conclude that blood-borne RT-PCR amplification of prostasin transcripts may lead to an earlier diagnosis of disseminated disease in patients with organ-confined carcinoma. The clinical significance of prostate cell detection and the potential applications of this new tool aside or along prostate-specific antigen or prostate-specific membrane antigen RT-PCR require longer-term follow-up.

Adult↗

Results of high dose rate brachytherapy, anterior pelvic exenteration and external beam radiotherapy for carcinoma of the female urethra.

PURPOSE: We evaluated a multimodality approach to locally advanced urethral carcinoma in women. MATERIALS AND METHODS: Between August 1996 and July 1999, 6 women were treated for locally advanced carcinoma of the urethra with anterior pelvic exenteration followed by high dose 192iridium intraoperative radiation therapy. Four of the 6 patients were also treated with neoadjuvant or concomitant platinum based chemotherapy. RESULTS: Two patients had no evidence of disease, 3 had distant metastasis and 2 had local recurrence at a mean followup of 21 months (range 12 to 47). Radiation was relatively well tolerated with no major adverse events. CONCLUSIONS: High dose intraoperative brachytherapy followed by external beam radiation is relatively well tolerated. Local control seems to have improved. We must evaluate a larger cohort of patients to determine this impact of the combined modality on local control and patient survival.

Adult↗