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Bertrand Tombal

Publications and source records attributed to Bertrand Tombal.

13 recordsLinked to original sources

Calcium store contents control the expression of TRPC1, TRPC3 and TRPV6 proteins in LNCaP prostate cancer cell line.

The mammalian homologues of the Drosophila transient receptor potential (TRP) represent a superfamily of ion channels involved in Ca(2+) homeostasis. Several members of this family are activated either by a depletion of the internal stores of Ca(2+) or by stimulation of G protein-coupled receptors. In androgen responsive prostate cancer cell line LNCaP, TRPC1, TRPC4 and/or TRPV6 have been reported to function as store-operated channels (SOCs) while TRPC3 might be involved in the response to agonist stimulation, possibly through the induction of diacylglycerol production by phospholipase C. However, the control of expression of these TRP proteins is largely unknown. In the present study, we have investigated if the expression of the TRP proteins possibly involved in the capacitative influx of calcium is influenced by the contents of Ca(2+) in the endoplasmic reticulum. Using real-time PCR and Western blot techniques, we show that the expression of TRPC1, TRPC3 and TRPV6 proteins increases after a prolonged (24-48 h) depletion of the stores with thapsigargin. The upregulation of TRPC1 and TRPC3 depends on the store contents level and involves the activation of the Ca(2+)/calmodulin/calcineurin/NFAT pathway. Functionally, cells overexpressing TRPC1, TRPC3 and TRPV6 channels after a prolonged depletion of the stores showed an increased [Ca(2+)](i) response to alpha-adrenergic stimulation. However, the store-operated entry of calcium was unchanged. The isolated overexpression of TRPV6 (without overexpression of TRPC1 and TRPC3) did not produce this increased response to agonists, therefore suggesting that TRPC1 and/or TRPC3 proteins are responsible for the response to alpha-adrenergic stimulation but that TRPC1, TPRC3 and TRPV6 proteins, expressed alone or concomitantly, are not sufficient for SOC formation.

Adrenergic alpha-Agonists↗

Magnetic resonance imaging of the axial skeleton enables objective measurement of tumor response on prostate cancer bone metastases.

BACKGROUND: There is currently no technique to image quantitatively bone metastases. Here, we assessed the value of MRI of the axial skeleton (AS-MRI) as a single step technique to quantify bone metastases and measure tumor response. METHODS: AS-MRI was performed in 38 patients before receiving chemotherapy for metastatic HRPCa, in addition to PSA, computed tomography of the thorax, abdomen, and pelvis [CT-TAP]; and Tc-99m bone scintigraphy. A second AS-MRI was performed in 20 patients who completed 6 months of chemotherapy. Evaluation of tumor response was performed using RECIST. RESULTS: Only 11 patients (29%) had RECIST measurable metastases in soft-tissues or lymph nodes on baseline CT-TAP. AS-MRI identified a diffuse infiltration of the bone marrow in 8 patients and focal measurable metastatic lesions in 25 patients (65%), therefore, doubling the proportion of patients with measurable lesions. Transposing RECIST on AS-MRI in 20 patients who completed 6 months of treatment, allows the accurate estimation of complete response (n = 2), partial response (n = 2), stable disease (n = 5), or tumor progression (n = 11), as it is done using CT-TAP in soft tissue solid metastases. CONCLUSIONS: MRI of axial skeleton enables precise measurement and follow-up of bone metastases as it is for other soft-tissue metastasis.

Bone Neoplasms↗

Tumor-associated antigen preferentially expressed antigen of melanoma (PRAME) induces caspase-independent cell death in vitro and reduces tumorigenicity in vivo.

Preferentially expressed antigen of melanoma (PRAME) is expressed in a wide variety of tumors, but in contrast with most other tumor associated antigens, it is also expressed in leukemias. The physiologic role of PRAME remains elusive. Interestingly, PRAME expression is correlated with a favorable prognosis in childhood acute leukemias. Moreover, a high expression of PRAME seems to be predominantly found in acute leukemias carrying a favorable prognosis. On these clinical observations, we assumed that PRAME could be involved in the regulation of cell death or cell cycle. In this study, we show that transient overexpression of PRAME induces a caspase-independent cell death in cultured cell lines (CHO-K1 and HeLa). Cells stably transfected with PRAME also exhibit a decreased proliferation rate due, at least partially, to an elevated basal rate of cell death. Immunocytochemistry of a FLAG-tagged PRAME, in vivo imaging of an enhanced green fluorescent protein-tagged PRAME, and Western blotting after cell fractionation reveal a nuclear localization of the protein. Using a microarray-based approach, we show that KG-1 leukemic cells stably transfected with PRAME present a significant decrease of expression of the heat-shock protein Hsp27, the cyclin-dependent kinase inhibitor p21, and the calcium-binding protein S100A4. The expression of these three proteins is known to inhibit apoptosis and has been associated with an unfavorable prognosis in a series of cancers. Finally, repression of PRAME expression by a short interfering RNA strategy increases tumorigenicity of K562 leukemic cells in nude mice. We suggest that all these observations might explain the favorable prognosis of the leukemias expressing high levels of PRAME.

Animals↗

Assessment of the transcriptional activity of p53 improves the prediction of recurrence in superficial transitional cell carcinoma of the bladder.

PURPOSE: To investigate the value of p53 functional analysis of separated alleles in yeast (FASAY) as a witness of p53/p21 pathway alteration and as a predictor of recurrence in superficial transitional cell carcinomas. EXPERIMENTAL DESIGN: p53 transcriptional activity was prospectively analyzed in 52 newly diagnosed transitional cell carcinoma using FASAY competent for the transactivation of p21 and bax promoters. TP53 and p21 gene expression was quantified by real-time PCR, and expression of corresponding proteins was assessed by immunohistochemistry. In addition to tumor stage and grade, the predictive value of FASAY, real-time PCR, and immunohistochemistry for tumor recurrence was assessed by Cox survival analysis. RESULTS: A total (p21 and bax) or partial (bax only) loss of transcriptional activity was observed in 15 of 52 (29%) and 4 of 52 (7.7%) cases, respectively, a partial loss being consistently associated with R283H mutation. p53 nuclear overexpression grossly overestimated (approximately 40%) or underestimated (approximately 10%) the true incidence of p53 transcriptional abnormalities, especially in Ta-T1 grade 1 to 2 tumors. Loss of p21 transactivation significantly correlated with decreased p21 gene expression and lack of expression of p21 (P = 0.001). FASAY had a better predictive value for recurrence than p53 immunohistochemistry (Cox hazard ratio, 6.57 versus 3.95; P = 0.0002 versus 0.019, respectively), whereas neither p21 immunohistochemistry (hazard ratio, 1.9; P = 0.29) nor TP53 or p21 gene expression were significant predictors of recurrence. The prognostic difference between FASAY and p53 immunohistochemistry was maintained in the subgroup of Ta-T1 grade 3 tumors. CONCLUSIONS: FASAY is a valuable surrogate marker for assessing p53/p21 pathway alteration and predicts transitional cell carcinoma recurrence better than p53 immunohistochemistry.

Adult↗

Prospective randomized evaluation of emergency extracorporeal shock wave lithotripsy (ESWL) on the short-time outcome of symptomatic ureteral stones.

OBJECTIVE: Here, we report the results of a randomized controlled trial (RCT) assessing the efficacy of emergency ESWL (eESWL) on the short-term outcome of symptomatic ureteral stones. MATERIAL: The trial enrolled 100 patients admitted in emergency room for renal colic caused by a ureteral radioopaque [corrected] stone. Patients were randomized to medical therapy alone or combined with eESWL. eESWL was performed within 6 hours of the onset of renal colic without specific analgesia on a Lithostar lithotripter (Siemens Medical, Munich, Germany). The primary endpoints were the proportion of patients stone free rate after 48 hours (SF-48) and the cumulative proportion of patients discharged from the hospital after 48 and 72 hours. RESULTS: Ureteral stone's location was proximal and distal in respectively 46% and 54% of the patients; stone's mean size was 5.5 mm (range 2-10 mm). Median hospital stay was 3 days, ranging from 1 to 14 days. SF-48 in the control group varied from 76% for distal stones <5 mm to 28.6% for proximal stones >5 mm, averaging at 61%. On average, eESWL increased SF-48 by 13% (p: 0.126), the gain strictly depending on stone size and location. SF-48 increase ranged from 40% for proximal stones >5 mm to 1.8% for distal stone <5 mm. On average, eESWL increased the median duration of hospital stay by one day. This mean negative impact results from ESWL increasing significantly the duration of hospital stay in case of distal stone, while slightly shortened it for stones located proximally. CONCLUSION: This study demonstrated for the first time that rapidly performed ESWL is a valuable therapeutic option to improve elimination of ureteral stones and shorten duration of hospital stay, proven that the stone is located proximally to the iliac vessels.

Adult↗

[Rupture of the renal artery and renal parenchyma in a pregnant woman with vascular form of Ehlers-Danlos syndrome].

A case of intraparenchymal renal haemorrhage associated with renal artery dissection, occurring at the end of pregnancy in a woman with a vascular form of Ehlers-Danlos syndrome is reported for the first time. This cases illustrates the potential risk of this syndrome and the importance of multidisciplinary management to ensure an appropriate diagnostic and therapeutic strategy. Magnetic resonance imaging is useful in this setting to elucidate complex cases of renal colic in pregnant women presenting an increased risk of ischaemic or haemorrhagic disorders.

Adult↗

[Malacoplakia in children].

Malakoplakia is a rare inflammatory disease, related to Enterobacteria infection in the context of a disorder of cell-mediated immunity. This disease does not have any specific clinical or laboratory signs and the diagnosis is exclusively based on histology. Malakoplakia is exceptional in children and usually involves the gastrointestinal tract. The authors report a rare case of malakoplakia of the urinary bladder in a 4-year-old child, in whom the initial diagnosis was an anomaly of the urachus.

Anti-Bacterial Agents↗

Characterization and multiparameter analysis of visual adverse events in irofulven single-agent phase I and II trials.

PURPOSE: Irofulven (6-hydroxymethylacylfulvene) is a novel agent, derived from illudin S, with potent apoptotic effects in preclinical models. In the Phase I trial evaluating intermittent weekly schedules, visual symptoms were dose limiting. The aim of this analysis was to better characterize the visual adverse events of irofulven and provide treatment guidelines. EXPERIMENTAL DESIGN: Clinical data from 277 patients entered in single-agent Phase I to II clinical trials who received irofulven on days 1 and 15 every 4 weeks; days 1, 8, and 15 every 4 weeks; or days 1 and 8 every 3 weeks were included in this multiparameter analysis. RESULTS: Overall, 74 patients (27%) experienced visual symptoms. The most frequently reported symptoms were flashing lights (12% of patients), blurred vision (9%), and photosensitivity (8%). Grade 3 toxicity was observed in 12 patients (4%). The incidence and severity of visual events were dose dependent, with no grade 3 visual events occurring at doses < or =0.50 mg/kg and grade 1 to 2 events in only 12% and 8% of patients, at doses of < or =0.50 mg/kg and < or =20 mg/m2, respectively. Grade 1 to 2 toxicity was reversible in most patients. Abnormal electroretinogram and abnormal visual fields were noted after irofulven treatment in 24 of 39 patients (62%) and 15 of 26 patients (58%), respectively. All but 1 patient who had electroretinogram assessment received doses >0.50 mg/kg. Clinical examination and visual field assessment were found to be better correlated with symptoms and appear to be more appropriate for surveillance of irofulven retinal symptoms than electroretinograms. CONCLUSIONS: On the basis of retained antitumor activity and reversibility of grade 1 and 2 visual symptoms at lower doses, it appears that an irofulven dose of < or =0.50 mg/kg or < or =20 mg/m2, not to exceed 50 mg in a single dose, given as a 30-minute infusion on days 1 and 8 every 3 weeks or days 1 and 15 every 4 weeks minimizes the frequency and severity of visual symptoms.

Adult↗

Role of store-dependent influx of Ca2+ and efflux of K+ in apoptosis of CHO cells.

Agents mobilising Ca(2+) from the endoplasmic reticulum are known to activate apoptosis. Whatever means are used, the release of Ca(2+) is often followed by a store-dependent entry of Ca(2+). Whether apoptosis is triggered by the depletion of the stores or by the subsequent store-dependent entry of Ca(2+) is still a matter of controversy. Here we studied apoptosis in CHO cells transfected with the rat neurotensin (NT) receptor, in which the store-dependent entry of Ca(2+) is abolished by repressing the transient receptor potential channel 2 (TRPC2) by an antisense oligonucleotide strategy (TRPC2(-) cells) [Cell Calcium 30 (2001) 157]. When stimulated with thapsigargin (TG), apoptosis occurred in both TRPC2(+) and TRPC2(-) cells but 12h earlier in TRPC2(+) cells, suggesting that store-dependent entry of Ca(2+) can accelerate the process. The expression and localisation of caspase-12, an enzyme that has been involved in the apoptosis triggered by a stress on the endoplasmic reticulum, was not different in TRPC2(+) and TRPC2(-) cells. On the contrary, the expression of GADD153 (Growth Arrest and DNA Damage inducible gene 153) triggered by TG treatment depended on external Ca(2+) and occurred earlier in TRPC2(+) than in TRPC2(-) cells. In these cells, we also noted the presence of K(+) channels activated by Ca(2+) (K(Ca) channels). Stimulation of TRPC2(+) cells with TG or with NT triggered a long sustained K(+) current, parallel to [Ca(2+)](i) transients, and resulting in a sustained hyperpolarisation of the cell membrane. K(+) current and hyperpolarisation were transient and not sustained in TRPC2(-) cells. Inhibition of K(Ca) channels with charybdotoxin dramatically reduced the K(+) current and also significantly brought down the level of apoptosis, suggesting that a prolonged efflux of K(+) could be involved in the apoptosis process. We conclude that in CHO cells, store-dependent entry of Ca(2+) can accelerate apoptosis by accelerating the expression of GADD153 and by inducing a prolonged efflux of K(+) out of the cell.

Animals↗

Prognostic value of circulating prostate cells in patients with a rising PSA after radical prostatectomy.

BACKGROUND: To predict poor outcome in patients with a biochemical recurrence (rising PSA) after radical prostatectomy (RP), urologists rely primarily on Gleason score, PSA doubling time, and time from surgery to biochemical (i.e., PSA) recurrence. In the present study, we assess the value of RT-PCR detection circulating prostate cells in blood of patients with a rising PSA. METHODS: RNA from blood samples was obtained from 55 patients with a rising PSA and from 45 patients without evidence of biochemical failure (PSA < 0.1 ng/ml). Both groups were matched for age, Gleason score, pT stage, and interval between radical prostatectomy and PCR testing. RESULTS: PSA positive cells were detected in 1/45 (2%) patients without a PSA recurrence and 19/55 (34%) patients with a PSA recurrence. In the rising PSA group, mean PSA doubling time was significantly shorter in patients with positive RT-PCR (5 months) than in patients with negative RT-PCR (16 months; P = 0.001). An earlier onset of recurrence was also detected in patients with a positive RT-PCR (31 months for positive RT-PCR vs. 50 months for negative RT-PCR) but this result did not achieve statistical significance (P = 0.102). Salvage radiation therapy was administered in 15 patients. Three of the five patients with a positive RT-PCR progressed during radiotherapy whereas 7 of the 10 patients with a negative RT-PCR obtained a complete response and none have progressed. CONCLUSIONS: These preliminary results suggest that RT-PCR detection of prostate cells in blood of patients after RP correlates with rapidly progressing biochemical failure after RP.

DNA, Neoplasm↗

Free/total PSA ratio does not improve prediction of pathologic stage and biochemical recurrence after radical prostatectomy.

OBJECTIVES: Despite several publications, the ability of the free/total (F/T) prostate-specific antigen (PSA) ratio to predict the pathologic extension of prostate cancer is still a matter of controversy. In addition, its ability to predict biochemical recurrence after radical prostatectomy has not yet been reported. METHODS: Since January 6, 1996, the F/T PSA ratio was prospectively measured preoperatively in 343 patients undergoing radical prostatectomy as the first treatment for localized prostate cancer. RESULTS: The ability to predict organ-confined disease was measured by receiver operating characteristic analysis. The areas under the curve were 0.66 for PSA density, 0.61 for total PSA, 0.60 for Gleason score, and 0.587 for the F/T PSA ratio. In multiple logistic regression analyses, the F/T PSA ratio was not a relevant predictor of organ-confined disease (Wald statistic 0.345 for P = 0.55). Similar results were obtained in the subgroup of patients with a PSA level between 2.5 and 10 ng/mL. The biochemical survival for the 270 patients who did not receive adjuvant therapy was 86% at 61 months. Statistically significant univariate predictors (P <0.05) of PSA recurrence were pT stage (log-rank 18.2) and Gleason grade (log-rank 8.8). The F/T PSA ratio was not a significant predictor of recurrence in the univariate analysis (log-rank 3.6 for P = 0.314) and in multivariate analysis (Wald statistic 0.2 for P = 0.97). CONCLUSIONS: These results suggest that the F/T PSA ratio is not helpful for the prediction of organ-confined disease and PSA recurrence after radical prostatectomy.

Adult↗