[Outcomes of GreenLight XPS-180W laser photovaporization for BPH larger than 80mL]. / Résultats de la photovaporisation prostatique par laser GreenLight XPS-180W dans l'hyperplasie bénigne de prostate (HBP) de gros volume (≥80mL).

AIM: To evaluate the results of GreenLight XPS photovaporization (PVP/XPS) with intraoperative transrectal ultrasonographic monitoring for the treatment of large Benign Prostatic Hyperplasia (BPH) (>80mL). PATIENTS AND METHODS: Operative and perioperative data of 82 patients were collected prospectively. Complications and functional outcomes (IPSS, quality of life (QoL) score, maximal flow rate and post-void residual (PVR)) were evaluated at 1, 3, 12 months post-operatively prostate volume and PSA were assessed at 3 and 12 months post-operatively. RESULTS: Median patient age was 68.5years (50-85). Twenty percent had an indwelling catheter and 5%/22% were on anticoagulant/antiplatelet therapy. Median prostate volume and PSA were 103mL (80-220) and 6.4ng/mL (0.66-44.0). Median operative time and energy delivered were 107min (46-219) and 581kJ (212-1193). Energy delivered/prostate volume was 5.4kJ/mL (1.6-10.5). Transurethral catheter was removed at day 1 or 2 in 96% of cases. Patients were discharged as outpatient, p.o. day 1 or day 2 in 4%, 55% and 21% of cases, respectively. Transfusion and Clavien≥3 complication rates were 1.2% and 3.7%. Significant improvement of IPSS (4 vs 19.5), QoL (1 vs 5), maximum flow rate (19.1 vs 8.2mL/s) and PVR (26 vs 100mL) was observed (P<0.001) at 12-months evaluation. PSA and prostate volume were decreased by 61 and 62%. Late complications were urethral strictures (6%), stress incontinence (1.2%). Eighty-five percent of patients had no antegrade ejaculation. CONCLUSION: The treatment of large BPH with PVP/XPS is safe and effective, with a long operative time. The functional outcomes are good and stable at mid-term evaluation. LEVEL OF EVIDENCE: 4.

[Comparison of the morbidity between limited and extended pelvic lymphadenectomy during laparoscopic radical prostatectomy]. / Comparaison de la morbidité entre curage étendu et curage limité au cours de la prostatectomie radicale laparoscopique.

OBJECTIVE: To compare the morbidity of limited pelvic lymphadenectomy to extended lymphadenectomy in patients undergoing LRP (Laparoscopic Radical Prostatectomy) for clinically localized prostate cancer. PATIENTS AND METHODS: We performed a prospective monocentric study focused on 303 consecutive patients having a pelvic lymphadenectomy during LRP from June 2000 to April 2010. One hundred and seventy six patients had a limited pelvic lymphadenectomy (June 2000-June 2006, group 1). One hundred and twenty seven patients had an extended pelvis lymphadenectomy (June 2006-April 2010, group 2) including two sub-groups according to the lateral limit of the procedure i.e. with (group 2a, 60 patients) or without dissection of the lateral side of the iliac artery (group 2b, 67 patients). RESULTS: Preoperative data (age, BMI, cTNM, Gleason score and PSA) were comparable between the groups. The number of lymph nodes and the incidence of metastatic lymph nodes were lower in group 1 (6,7 lymph nodes and 5,7%) compared to group 2 (a+b) (15.6 lymph nodes and 18.9%) (P=0.001 and P=0.0004). However, there was no difference between groups 2a and 2b (15.4 and 16.7% vs 15,8 and 20.8% P=0.65 respectively). There were more complications in the extended lymphadenectomy group compared to the limited procedure (35.4% vs 14.2%, P=0.0001), in particular more lymphatic complications (27.5% vs 10.2% P=0.0001) and lymphoedema (LO) (15.7% vs 0.6% P=0.00001). However the lymphorhea (LR) and lymphocele (LC) rate was not different (P=0.11 and P=0.17). All complications were mainly of low Clavien's classification grade (1+2) whatever the group of lymphadenectomy. The hospital stay was not increased in group 2a or 2b in regard to group 1. The rate of LR and LC was higher in group 2a than in group 1 (P=0.02 and P=0.05) but not between group 2b and 1 (P=0.81 and P=0.47). CONCLUSION: Our study showed a higher rate of complications after extended pelvic lymphadenectomy but of low grade in most cases. Moreover the lateral dissection sparing the lateral side of the iliac artery reduced the risk of lymphatic complications without decreasing the number of lymph nodes removed and the rate of metastasis.

Which protocol for prostate biopsies in patients with a positive MRI? Interest of systematic biopsies by sectors.

BACKGROUND: Current prostate biopsy (PBx) protocol for prostate cancer (PCa) diagnosis is to perform systematic biopsies (SBx) combined with targeted biopsies (TBx) in case of positive MRI (i.e. PI-RADS ≥ 3). To assess the utility of performing SBx in combination with TBx, we determined the added value of SBx brought to the diagnosis of PCa according to their sextant location and MRI target characteristics. METHODS: In our local prospectively collected database, we conducted a single-center retrospective study including all patients with a suspicion of PCa, who underwent transrectal ultrasound-guided (TRUS) prostate biopsies (PBx) with a prior MRI and a single lesion classified as PI-RADS ≥ 3. We have characterized the SBx according to their location on MRI: same sextant (S-SBx), adjacent sextant (A-SBx), ipsilateral side (I-SBx) and contralateral side (C-SBx). The added value of SBx and TBx was defined as any upgrading to significant PCa (csPCa) (ISUP ≥2). RESULTS: 371 patients were included in the study. The added value of SBx was 10% overall. Regarding the lesion location and the SBx sextant, the added value of SBx was: 5.1% for S-SBx, 5.4% for A-SBx, 4.9% for I-SBx and 1.9% for C-SBx. The overall added value of SBx was 6.8% for PI-RADS 3 lesions, 14% for PI-RADS 4 lesions and 6.7% for PI-RADS 5 lesions (p = 0.063). The added value of SBx for contralateral side was 1.9% (2/103), 3.1% (5/163) and 0% (0/105) for PI-RADS 3, PI-RADS 4 and PI-RADS 5 lesions, respectively (p = 0,4). The added value of SBx was lower when the number of TBx was higher (OR 0.57; CI 95% 0.37-0.85; p = 0.007). CONCLUSIONS: Our results suggest that the utility of performing SBx in the contralateral lobe toward the MRI lesion was very low, supporting that they might be avoided.

[Urinary continence following laparoscopic radical prostatectomy: qualitative analysis]. / Étude qualitative de la continence urinaire après prostatectomie radicale laparoscopique.

PURPOSE: The main purpose of this study was to report urinary continence after laparoscopic radical prostatectomy (LRP) for localised prostate cancer and the return to baseline rate for urinary continence. The minor purpose was to determine the risk factors, which influence return to baseline urinary continence after radical prostatectomy. METHODS: Prospective evaluation of urinary continence with self-administered questionnaire in 300 consecutive LRP for localized prostate cancer. RESULTS: After LRP, at 3, 6 and 12 months, respectively 12.5%, 23% and 33.7% of patients recover baseline urinary continence. Fifty-four percent, 72.3% and 78.4% of patients did not wear pads 3, 6 and 12 months after LRP. In patients without pad, 43 % recovered baseline continence one year after radical prostatectomy. In univariate analysis, age older than 60 years (P=0.003, P=0.003, P=0.02, 3, 6 and 12 months after LRP) and no sparing of neurovascular bundles (P=0.01, P=0.08 at 3 and 6 months after LRP) were risks factors of urinary incontinence. In multivariate analysis, only age older than 60 years (P=0.018, P=0.01 and P=0.01 at 3, 6 and 12 months after LRP) was a risk factor of urinary incontinence. CONCLUSION: One year after LRP, 66.3% of patients had urinary incontinence according to our evaluation using stringent criteria, i.e. return to baseline continence status. However, only 21.6% of patients wore pads and less than 2% wore more than two pads per day.

Bcl-2 protects from lethal hepatic apoptosis induced by an anti-Fas antibody in mice.

Fas is an apoptosis-signalling cell surface antigen that has been shown to trigger cell death upon specific ligand or antibody binding. Treatment of mice with an anti-Fas antibody causes fulminant hepatic failure due to massive apoptosis. To test a putative protective effect of the anti-apoptotic Bcl-2 protein, transgenic mice were generated to express the human bcl-2 gene product in hepatocytes. Early onset of massive hepatic apoptosis leading to death was observed in all nontransgenic mice treated with an anti-Fas antibody. By contrast, hepatic apoptosis was delayed and dramatically reduced in transgenic animals, yielding a 93% survival rate. These results demonstrate that Bcl-2 is able to protect from in vivo Fas-mediated cytotoxicity, and could be of significance for preventing fulminant hepatic failure due to viral hepatitis in humans.

Prognostic factors after adrenalectomy for adrenal metastasis.

PURPOSE: Very few studies have sought prognostic factors after adrenalectomy for metastasis. The aim of this study was to assess prognostic factors for oncological outcomes after adrenalectomy for adrenal metastasis. METHODS: All adrenalectomies for metastases performed in seven centers between 2006 and 2016 were included in a retrospective study. Recurrence-free survival (RFS) and cancer-specific survival (CSS) were estimated using the Kaplan-Meier method. Prognostic factors for CSS and RFS were sought by Cox regression analyses. RESULTS: 106 patients were included. The primary tumors were mostly renal (47.7%) and pulmonary (32.3%). RFS and CSS estimated rates at 5 years were 20.7% and 63.7%, respectively. In univariate analysis, tumor size (HR 3.83; p = 0.04) and the metastasis timing (synchronous vs. metachronous; HR 0.47; p = 0.02) were associated with RFS. In multivariate analysis, tumor size (HR 8.28; p = 0.01) and metastasis timing (HR 18.60; p = 0.002) were significant factors for RFS. In univariate analysis, the renal origin of the primary tumor (HR 0.1; p < 0.001) and the disease-free interval (DFI; HR 0.12; p = 0.02) were associated with better CSS, positive surgical margins with poorer CSS (HR 3.4; p = 0.01). In multivariate analysis, the renal origin of the primary tumor vs. pulmonary (HR 0.13; p = 0.03) and vs. other origins (HR 0.10; p = 00.4) and the DFI (HR 0.01; p = 0.009) were prognostic factors for CSS. CONCLUSION: In this study, tumor size and synchronous occurrence of the adrenal metastasis were associated with poorer RFS. Renal origin of the primary tumor and longer DFI were associated with better CSS. These prognostic factors might help for treatment decision in the management of adrenal metastasis.

ICE inhibitor YVADcmk is a potent therapeutic agent against in vivo liver apoptosis.

In liver, apoptosis is a physiological process involved in the clearance of injured cells and in homeostatic control [1]. However, in patients with viral fulminant hepatitis or with nonacute liver diseases [2], dramatic liver failure or secondary cirrhosis results from the death of hepatocytes, which express the cell-surface receptor Fas, by apoptosis. To date, treatment of fulminant hepatitis relies mainly on orthotopic liver transplantation, which is limited by immunological complications and graft availability. Unravelling the molecular mechanisms that underlie acute liver failure could allow the design of an appropriate therapy. Ligand-bound Fas and tumour necrosis factor alpha (TNF-alpha) induce hepatic apoptosis in mice [3-6]. In various cell types, Fas- or TNF-alpha-induced apoptosis is blocked by viral proteins (such as p35 and CrmA) as well as by a decoy peptide (YVADcmk) [7-11], suggesting that these mechanisms of apoptosis involve ICE (interleukin-1 beta converting enzyme)-like proteases. Here, we report that, in vivo, pre-treatment of mice with YVADcmk protects them from the lethal effect of anti-Fas antibody and from liver failure induced by injection of TNF-alpha. Remarkably, YVADcmk administration is also highly effective in rescuing mice that have been pretreated with anti-Fas antibody from rapid death, despite extensive hepatic apoptosis. This dramatic curative effect could be of clinical benefit for the treatment of viral and inflammatory liver diseases.

Fas-dependent apoptosis is impaired by SV40 T-antigen in transgenic liver.

A transgenic mouse model for hepatocarcinoma has been previously produced by targeting SV40 T-antigen expression to the liver. To evaluate the perturbation of cell death occurring during hepatocarcinogenesis, we examined the Fas-induced apoptosis on hepatocytes expressing T-antigen. Whereas anti-Fas antibody induced apoptosis in primary cultured normal hepatocytes, they imparted a weak cytotoxicity on primary cultured hepatocytes expressing T-antigen. This resistance of hepatic Fas-mediated apoptosis appears to result in an enhancement of a protective mechanism involving the protein kinase C signaling pathway rather than in a down-regulation of Fas-antigen expression. We further demonstrated that anti-Fas antibody does not have as efficient a lethal effect in T-antigen transgenic mice as in wild-type mice. The livers of transgenic mice injected with anti-Fas mAbs showed large intact regions with a few scattered apoptotic bodies: these regions strictly corresponded with carcinoma nodules, expressing high level of T-antigen. Our results describe a novel function for SV40 T-antigen which could contribute to viral pathogenesis by protecting infected cells against the host apoptotic defense mechanism.

GATA-and SP1-binding sites are required for the full activity of the tissue-specific promoter of the tal-1 gene.

The tal-1 gene, which is frequently activated in human T cell acute leukemias (T-ALLs), codes for a protein of the basic helix-loop-helix family (b-HLH) and potentially a transcription factor. In human and murine hematopoiesis tal-1 is expressed during the differentiation of the erythroid, megakaryocytic and mastocytic cell lineages. The expression of tal-1 appears to be comodulated with that of the transcription factor GATA-1 gene, suggesting that the GATA-1 protein may regulate the tal-1 gene activity in these hematopoietic lineages. To get further insights into the molecular mechanisms that control tal-1 expression, we have isolated 5' sequences of the murine gene and compared them to their human counterparts. The 5' flanking sequences from the two genes show several regions of high homology. The alignment of both sequences enabled us to predict that similarly, to the human, the mouse gene contains two alternative first exons (Ia and Ib). Remarkably, in both species, the proximal region of the tissue-specific exon Ia (i.e. gene segment -122 to +1) contains two GATA-motifs (at -65 and -33) and one SP-1 consensus binding site (-59). Mobility shift assays demonstrate that GATA proteins are able to interact with both GATA-motifs in a sequence specific fashion, but with different efficiencies. Moreover transfection studies show that the GATA-1 protein directly mediates tal-1 transcription by interacting with the -122/+1 fragment, defined as a minimal promoter in erythroid cells. Mutagenesis of the promoter establishes that the -33 GATA-binding site present in this fragment is critical for tal-1 expression in erythroid cells, but by itself does not lead to full promoter activity. Indeed, further mutations show that the second -65 GATA-binding site and the binding motif for SP1 (-59) significantly contribute to the overall activity of the proximal tal-1 promoter. Altogether, our data provide evidence that GATA-1 cooperates with the transcription factor SP1 to mediate the erythroid-specific expression of the tal-1 gene.

Compensatory apoptosis in response to SV40 large T antigen expression in the liver.

Transgenesis allows the in vivo determination of the effects of oncogene expression in normal tissues. In an attempt to understand the mechanism underlying liver transformation, we have previously created transgenic mice carrying the SV40 early gene sequences, which developed hepatocarcinoma in a reproducible way. In the present study, we show that constant expression of the transgene was directly correlated to an abnormally increased hepatocyte proliferation, even at the adult stage. We further demonstrate in this model that the preneoplastic stage of hepatocarcinoma is characterized by marked ploidy alterations as early as 1 month, including the emergence of aneuploid and hyperpolyploid cells, and the persistence of an important diploid cell population. We show that this elevated proliferation is early and transiently counterbalanced by a mechanism of apoptosis, which maintains liver homeostasis. The disappearance of this programmed cell death response effective during preneoplasia might signal the commitment of the liver to neoplasia.

The consequence of p53 overexpression for liver tumor development and the response of transformed murine hepatocytes to genotoxic agents.

To analyse the effect of p53 on liver tumor development, we generated transgenic mice overexpressing wild-type p53 in the liver and crossed them with transgenic mice in which the expression of the SV40 large T antigen (TAg) induces hepatic tumors. Remarkably, whereas preneoplastic TAg liver exhibited anisocaryosis and anisocytosis, TAg/p53 liver never presented any dysplastic cells. Moreover, whereas expression of p53 did not affect hepatic development, its constitutive expression in tumorigenic livers resulted in a significantly enhanced apoptosis once nodules had appeared. In contrast, p53 overexpression did not modify the elevated proliferation of TAg-transformed hepatocytes and had no effect on hepatocarcinoma progression. In vitro analysis of primary hepatocytes exposed to various genotoxic agents showed that p53 failed to sensitize normal or TAg-transformed hepatocytes to apoptosis, except when high doses of doxorubicin, UV-B and UV-C radiation were used. Our results confirmed that the hepatocyte cell type is very resistant to genotoxic agents and showed that constitutive expression of p53 failed to improve their responsiveness. In addition, our results showed that suppression of dysplastic cells, probably by restoring normal cytokinesis and karyokinesis, and enhancement of apoptosis by means of p53 overexpression were insufficient to counteract or delay the TAg-induced liver tumoral progression. Oncogene (2000) 19, 3498 - 3507

The amino-terminal region of SV40 large T antigen is sufficient to induce hepatic tumours in mice.

The transforming activity of SV40 large T-antigen (Tag) depends on its binding to cellular proteins involved in the control of the cell cycle (p53, pRb, p300..) and on the J-domain region in the amino-terminus. We established transgenic lines expressing wild-type or Tag mutant proteins lacking one of the three transforming domains, to determine the respective contributions of these domains to hepatic tumour formation. Tag mutants with no pRb-binding domain or N-terminal fragment did not cause neoplastic liver abnormalities. The d11137 Tag mutant protein, which inhibits pRb function without affecting p53, induced hepatic tumours. These tumours grew significantly faster than those induced by wild-type Tag. Our results demonstrate different requirements for each of the inactivating functions of SV40 Tag in hepatocyte transformation and show that the loss of p53 function has only a moderate effect on hepatic tumour formation.

Protection of hepatocytes from Fas-mediated apoptosis by a non-transforming SV40 T-antigen mutant.

Apoptosis is crucial for the normal development of multicellular organisms and is also important for clearing injured cells, such as virus-infected cells or cancer cells. Defective regulation of apoptosis may contribute to viral pathogenesis and aetiology of cancer. Apoptosis of injured cells is principally triggered by the immune system through cytokines such as Fas-ligand and TNF-alpha. Thus, one of the functions of a viral oncogene, such as SV40T-antigen, may be to inhibit cytokine-mediated apoptosis. We previously demonstrated that Fas-mediated apoptosis of hepatocytes is blocked by the wild-type SV40T-antigen during hepatocarcinogenesis. We determined whether this inhibition was directly related to the T-antigen or whether it is a secondary event of cell transformation, by generating transgenic mice expressing a non-transforming T-antigen mutant able to bind endogenous p53 in the liver. This T-antigen mutant cannot induce hepatocarcinoma, unlike the wild-type T-antigen. However, like the wild-type T-antigen, the mutant was a potent inhibitor of apoptosis induced by the Fas-receptor, but not by the TNF-receptor. Therefore, SV40T-antigen has a new property; the inhibition of Fas-mediated apoptosis, which could facilitate the emergence of transformed hepatocytes, but is not sufficient to induce it.

Isolation and characterization of the gene encoding the muscle-specific isozyme of human phosphoglycerate mutase.

The human muscle-specific phosphoglycerate mutase encoding gene (PGAM-M) has been cloned from a genomic cosmid library and sequenced. The sequence corresponding to the coding region was evaluated and revised by sequencing of the protein itself, fully confirming our results. The amino acid sequence of the M isozyme presented a 80.6% homology with the B isozyme (non-muscle-specific isozyme), a value higher than previously reported. The PGAM-M gene is composed of three exons, which consist of 454, 180 and 202 bp, respectively, and are separated by two introns of 103 bp and approx. 5.6 kb, respectively. Comparison of the structure of the human PGAM-M gene with that coding for human bisphosphoglycerate mutase, an erythroid-specific enzyme belonging to the same multifunctional enzyme family, revealed that the location of the second intron is similar in each gene and corresponds to a tertiary subdomain in the spatial structure of the protein. The transcription start point (tsp) in the PGAM-M gene was identified by both primer extension and S1 nuclease-protection experiments. A TATA-box-like element was observed 29 bp upstream from the tsp; the sequence ATTGG, inverse/complementary to CCAAT-box, was found 40 bp upstream from the supposed TATA box. No muscle-specific consensus sequences could be detected in the 5'-untranslated region. Only one polyadenylation AATAAA signal was observed in the short 3'-untranslated region (43 bp long). Finally, only one copy of this gene is present in the human genome instead of the several copies found for the PGAM-B gene, suggesting the possible evolutionary origin of the muscle subunit in a modified copy of the PGAM-B gene.

Targeting SKCa channels in cancer: potential new therapeutic approaches.

Many studies have reported changes in potassium channel expression in many cancers and the involvement of these channels in various stages of cancer progression. By contrast, data concerning SKCa channels (small conductance calcium-activated potassium channels) have only recently become available. This review aims i) to present the structure and physiology of SKCa channels, ii) to provide an overview of published data concerning the SKCa proteins produced in tumor cells, and, whenever possible, the biological function assigned to them and iii) to review previous and novel modulators of SKCa channels. SKCa channels are activated by low concentrations of intracellular calcium and consist of homo- or heteromeric assemblies of α-subunits named SK1, SK2 and SK3. SK2-3 channels are expressed in tumors and have been assigned a biological function in cancer cells: the enhancement of cell proliferation and cell migration by hijacking the functions of SK2 and SK3 channels, respectively. Two major classes of SKCa modulators have been described: toxins (apamin) and small synthetic molecules. Most SKCa blockers are pore blockers, but some modify the calcium sensitivity of SKCa channels without interacting with the apamin binding site. In this review, we present edelfosine and ohmline as atypical anticancer agents and novel SK3 inhibitors. Edelfosine and ohmline are synthetic alkyl-lipids with structures different from all previously described SKCa modulators. They should pave the way for the development of a new class of migration-targeted anticancer agents. We believe that such blockers have potential for use in the prevention or treatment of metastasis.

CXCR4 inhibitors selectively eliminate CXCR4-expressing human acute myeloid leukemia cells in NOG mouse model.

The chemokine receptor CXCR4 favors the interaction of acute myeloid leukemia (AML) cells with their niche but the extent to which it participates in pathogenesis is unclear. Here, we show that CXCR4 expression at the surface of leukemic cells allowed distinguishing CXCR4 (high) from CXCR4(neg/low) AML patients. When high levels of CXCR4 are expressed at the surface of AML cells, blocking the receptor function with small molecule inhibitors could promote leukemic cell death and reduce NOD/Shi-scid/IL-2Rγ(null) (NOG) leukemia-initiating cells (LICs). Conversely, these drugs had no efficacy when AML cells do not express CXCR4 or when they do not respond to chemokine CXC motif ligand 12 (CXCL12). Functional analysis showed a greater mobilization of leukemic cells and LICs in response to drugs, suggesting that they target the interaction between leukemic cells and their supportive bone marrow microenvironment. In addition, increased apoptosis of leukemic cells in vitro and in vivo was observed. CXCR4 expression level on AML blast cells and their migratory response to CXCL12 are therefore predictive of the response to the inhibitors and could be used as biomarkers to select patients that could potentially benefit from the drugs.

The SK3/K(Ca)2.3 potassium channel is a new cellular target for edelfosine.

BACKGROUND AND PURPOSE: The 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (edelfosine) is an ether-linked phospholipid with promising anti-cancer properties but some side effects that preclude its full clinical therapeutic exploitation. We hypothesized that this lipid could interact with plasma membrane ion channels and modulate their function. EXPERIMENTAL APPROACH: Using cell migration-proliferation assays, patch clamp, spectrofluorimetry and ¹²5I-Apamin binding experiments, we studied the effects of edelfosine on the migration of breast cancer MDA-MB-435s cells, mediated by the small conductance Ca²(+) -activated K(+) channel, SK3/K(Ca)2.3. KEY RESULTS: Edelfosine (1 µM) caused plasma membrane depolarization by substantially inhibiting activity of SK3/K(Ca)2.3 channels, which we had previously demonstrated to play an important role in cancer cell migration. Edelfosine did not inhibit ¹²5I-Apamin binding to this SK(Ca) channel; rather, it reduced the calcium sensitivity of SK3/K(Ca)2.3 channel and dramatically decreased intracellular Ca²(+) concentration, probably by insertion in the plasma membrane, as suggested by proteinase K experiments. Edelfosine reduced cell migration to the same extent as known SK(Ca) channel blockers. In contrast, K+ channel openers prevented edelfosine-induced anti-migratory effects. SK3 protein knockdown decreased cell migration and totally abolished the effect of edelfosine on MDA-MB-435s cell migration. In contrast, transient expression of SK3/K(Ca)2.3 protein in a SK3/K(Ca)2.3-deficient cell line increased cell migration and made these cells responsive to edelfosine. CONCLUSIONS AND IMPLICATIONS: Our data clearly establish edelfosine as an inhibitor of cancer cell migration by acting on SK3/K(Ca)2.3 channels and provide insights into the future development of a new class of migration-targeted, anti-cancer agents.

New alkyl-lipid blockers of SK3 channels reduce cancer cell migration and occurrence of metastasis.

Edelfosine is an inhibitor of SK3 channel mediated cell migration. However, this compound bears adverse in vivo side effects. Using cell SK3 dependent cell-migration assay, patch-clamp, (125)I-apamin binding, and in vivo experiments we tested the ability of 15 lipid derivatives with chemical structures inspired from edelfosine to inhibit SK3 channels. Using a structure-activity relationship approach we identified an edelfosine analog named Ohmline (1-O-hexadecyl- 2-O-methyl-sn-glycero-3-lactose) with potent inhibitory effects on the SK3 channel. Its potency was greater for SK3 channels than for SK1 channels; it did not affect IKCa channels and only slightly but not significantly affected SK2 channels. This is the first SKCa channel blocker that can be used to discriminate between SK2 and SK1/SK3 channels and represents a useful tool to investigate the functional role of SK3 channels in peripheral tissues (that do not express SK1 channels). This compound, which acts with an IC(50) of 300 nM, did not displace apamin from SKCa channels and had no effect on non-specific edelfosine targets such as protein kinase C (PKC), receptors for platelet activating factor (PAF) and lysophosphatidic acid (LPA), as well as non-cancerous cells. This is promising because the pitfalls associated with the use of edelfosine-like compounds have been that their effective and high concentrations are often cytotoxic due to their detergent-like character causing normal cell lysis. Finally, Ohmline reduced metastasis development in a mice model of tumor indicating that this compound could become a lead compound for the first class of lipid-antimetastatic agent.

[Apoptosis and liver diseases]. / Apoptose et pathologies hépatiques.

Regulation of homeostasic balance between cell proliferation and cell death, called apoptosis, is essential for development and maintenance of multicellular organisms. Recent research into the molecular mechanisms of apoptosis has revealed that apoptosis is a genetically and evolutionarily conserved process that can become deranged when the components of the cellular apoptotic machinery are mutated, perturbated by viral gene products or present in inappropriated quantities. Analysis of the regulatory apoptotic pathways has led to a better understanding of the etiology and pathogenesis of many human diseases, notably cancers, infectious diseases or autoimmune diseases. Our understanding of the regulation of apoptosis in health and disease is far from complete and the use of understanding into new therapeutic modalities has only begun to be approached.