Mesenchymal stem cells secretomes' affect multiple myeloma translation initiation.

Bone marrow mesenchymal stem cells' (BM-MSCs) role in multiple myeloma (MM) pathogenesis is recognized. Recently, we have published that co-culture of MM cell lines with BM-MSCs results in mutual modulation of phenotype and proteome (via translation initiation (TI) factors eIF4E/eIF4GI) and that there are differences between normal donor BM-MSCs (ND-MSCs) and MM BM-MSCs (MM-MSCs) in this crosstalk. Here, we aimed to assess the involvement of soluble BM-MSCs' (ND, MM) components, more easily targeted, in manipulation of MM cell lines phenotype and TI with specific focus on microvesicles (MVs) capable of transferring critical biological material. We applied ND and MM-MSCs 72h secretomes to MM cell lines (U266 and ARP-1) for 12-72h and then assayed the cells' (viability, cell count, cell death, proliferation, cell cycle, autophagy) and TI (factors: eIF4E, teIF4GI; regulators: mTOR, MNK1/2, 4EBP; targets: cyclin D1, NFκB, SMAD5, cMyc, HIF1α). Furthermore, we dissected the secretome into >100kDa and <100kDa fractions and repeated the experiments. Finally, MVs were isolated from the ND and MM-MSCs secretomes and applied to MM cell lines. Phenotype and TI were assessed. Secretomes of BM-MSCs (ND, MM) significantly stimulated MM cell lines' TI, autophagy and proliferation. The dissected secretome yielded different effects on MM cell lines phenotype and TI according to fraction (>100kDa- repressed; <100kDa- stimulated) but with no association to source (ND, MM). Finally, in analyses of MVs extracted from BM-MSCs (ND, MM) we witnessed differences in accordance with source: ND-MSCs MVs inhibited proliferation, autophagy and TI whereas MM-MSCs MVs stimulated them. These observations highlight the very complex communication between MM and BM-MSCs and underscore its significance to major processes in the malignant cells. Studies into the influential MVs cargo are underway and expected to uncover targetable signals in the regulation of the TI/proliferation/autophagy cascade.

First trimester human placental factors induce breast cancer cell autophagy.

Placental factors, progesterone included, facilitate breast cancer cell line (BCCL) motility and thus may contribute to the advanced breast cancer found during pregnancy. Cancer and placental implantations are similar; the last is accompanied by extravillous trophoblast cell invasion and autophagy which are interlinked. We aimed to analyze the effect of first trimester human placenta on BCCL autophagy. BCCLs (MCF-7/T47D) were cultured with placental explants (60 h) or placental supernatants (24 h). Following cultures, BCCLs were sorted out for RNA/protein extraction. RNA served for microarray/qPCR (BNIP3) and protein for Western blot (HIF1α, LC3BII) analyses. Inhibitors were added to the placenta-MCF-7 coculture or placental supernatants (autophagy inhibitor-3MA, progesterone receptor (PR) inhibitor-RU486, and HIF1α inhibitor-Vitexin) in order to evaluate their effects on BCCL motility and LC3BII/HIF1α expression. LC3BII (an autophagy marker) expression was elevated in BCCLs following placental explant coculture and exposure to placental supernatants. The autophagy inhibitor (3MA) repressed the placenta-induced MCF-7/T47D migration, establishing a connection between BCCL autophagy and migration. Microarray analysis of MCF-7 following placenta-MCF-7 coculture showed that "HIF1α pathway," a known autophagy facilitator, was significantly manipulated. Indeed, placental factors elevated HIF1α and its target BNIP3 in the BCCLs, verifying array results. Lastly, PR inhibitor reduced HIF1α expression and both PR and HIF1α inhibitors reduced MCF-7 LC3BII expression and motility, suggesting involvement of the PR-HIF1α axis in the autophagy process. Placental factors induced BCCL autophagy that is interlinked to their motility. This suggests that autophagy-related molecules may serve as targets for therapy in pregnancy-associated breast cancer.

The effect of heat shock protein 27 on extravillous trophoblast differentiation and on eukaryotic translation initiation factor 4E expression.

Heat shock protein (HSP27) is expressed in human placentae. Previously, we showed that HSP27 is expressed in the villous cell column of first trimester placental explants and in extravillous trophoblast (EVT) cells. EVT differentiation is accompanied by increased motility, matrix metalloproteinase (MMP) activity, decreased proliferation and expression of specific markers such as HLAG and CD9. HSP27 regulates cell apoptosis, migration, protein stability and the availability of eukaryotic translation initiation factors, such as eukaryotic translation initiation factor 4E (eIF4E). eIF4E supports trophoblast cell proliferation and survival. We wanted to explore the effect of HSP27 silencing on trophoblast cell phenotype, EVT markers and eIF4E expression and regulators [4E-binding protein (4E-BP1) and MAP kinase-interacting kinase (MNK1)]. This study evaluated the effect of HSP27 siRNA on placental explant and HTR-8/SVneo migration, MMP activity/mRNA, cell death, cell cycle, HLAG/CD9 levels, and eIF4E and its regulators' total and phosphorylated levels. Furthermore, we evaluated HSP27 levels in placentae exposed to ribavirin, which triggers EVT differentiation. We found that HSP27 silencing increased cell death in HTR-8/SVneo and placental explants. Furthermore, it reduced HTR-8/SVneo migration and EVT outgrowth from the explants (P < 0.05), MMP2 activity and expression of EVT markers HLAG and CD9 (in placental explants and HTR-8/SVneo, respectively, P < 0.05). Induction of EVT differentiation by ribavirin elevated HSP27 levels. Finally, HSP27 silencing in both HTR-8/SVneo and placental explants reduced eIF4E levels (33 and 28%, respectively, P < 0.05) and the levels of its regulators 4E-BP1 and MNK1 (37 and 32%, respectively, done on HTR-8/SVneo only), but not their phosphorylated forms. Altogether, our results suggest that HSP27 contributes to EVT cell differentiation.

The involvement of eukaryotic translation initiation factor 4E in extravillous trophoblast cell function.

UNLABELLED: Extravillous trophoblast cells (EVT) are major players in placental implantation. They differentiate in the villous cell column, invade to the uterus and remodel the uterine spiral arteries. Trophoblast and tumor cells have similar invasion mechanisms, share similar biochemical mediators (e.g. c-myc, MMP9) and growth-factors (e.g. VEGF). The mRNA of these proteins has extremely structured 5-UTR and their translation is highly dependent on eukaryotic-translation-initiation-factor-4E (eIF4E). Cancer cells have elevated eIF4E and are more vulnerable to its silencing than normal cells. We speculated that like cancer, trophoblast function is highly eIF4E dependent. OBJECTIVE: Analyze eIF4E involvement in EVT differentiation and function. STUDY DESIGN: EIF4E levels were assessed in first-trimester human placentae and in placental explants before and after EVT differentiation. The effect of eIF4E knockdown (siRNA, ribavirin) on the phenotype of placental explant and EVT cell lines (HTR-8/SVNEO) was evaluated. Tested parameters included eIF4E and its target levels, migration, invasion, cell death, cell cycle and cell count. RESULTS: High eIF4E levels were found in cytotrophoblast and especially EVT cells during their differentiation in the villi, compared to other placental cell types. EIF4E silencing increased cell death and cell cycle arrest in placental explants and HTR-8/SVNEO cells. Although it induced EVT outgrowth in the placental explants, it reduced HTR-8/SVNEO motility, reflecting the importance of using ex vivo models that include an intact placental microenvironment in its original architecture. CONCLUSIONS: Our results suggest that eIF4E prevents final EVT differentiation and supports placental cell proliferation and survival. A balance between cell proliferation and differentiation is crucial for placental development and implantation.

Metrology and ergonomic mensuration parameters.

This poster intends to show how measurement, its concepts and methods are decisive to the ergonomic praxis and why their agents should be aware of how incertainty can be taken in the process in order to increase the accuracy of measurement and findings.

Ergonomic initiatives at Inmetro: measuring occupational health and safety.

This work studies biomechanical hazards to which the workforce of Instituto Nacional de Metrologia, Qualidade e Tecnologia Industrial (Inmetro) is exposed. It suggests a model for ergonomic evaluation of work, based on the concepts of resilience engineering which take into consideration the institute's ability to manage risk and deal with its consequences. Methodology includes the stages of identification, inventory, analysis, and risk management. Diagnosis of the workplace uses as parameters the minimal criteria stated in Brazilian legislation. The approach has several prospectives and encompasses the points of view of public management, safety engineering, physical therapy and ergonomics-oriented design. The suggested solution integrates all aspects of the problem: biological, psychological, sociological and organizational. Results obtained from a pilot Project allow to build a significant sample of Inmetro's workforce, identifying problems and validating the methodology employed as a tool to be applied to the whole institution. Finally, this work intends to draw risk maps and support goals and methods based on resiliency engineering to assess environmental and ergonomic risk management.

Hormone-dependent placental manipulation of breast cancer cell migration.

BACKGROUND: Breast cancer during pregnancy is often more advanced than in non-pregnant women. Nevertheless, no case of metastasis inside the placenta has been reported. Previously, we showed that placental-explants eliminated breast cancer cells from their surroundings, due to cell-death and elevated migration. Our objective was to find the underlying mechanisms of these phenomena. METHODS AND RESULTS: Our model contained Michigan Cancer Foundation 7 (MCF7) or T47D cells co-cultured with and without human placental explants. Microarray analysis, validated by quantitative PCR, of MCF7 following their placental co-culture suggested activation of estrogen (E(2)) signaling. As extensive cross-talk exists between E(2) and progesterone, their involvement in mediating placental effects on breast cancer cells was tested. Indeed, addition of E(2) and progesterone receptor (ER and PR) inhibitors to the co-culture system reduced cancer cell motility, yet did not alter cell-cycle or death. E(2) and progesterone concentrations in placental media were found to be similar to those of early pregnancy blood levels. Interestingly, placental-breast cancer co-culture media contained lower progesterone (P < 0.05) and higher E(2) (200%, P < 0.05) levels than placentae cultured separately. Placental supernatant and E(2) and progesterone at placental levels were sufficient to increase MCF7 and T47D migration and invasion (P < 0.05), yet did not alter MCF7 cell-cycle or death. Furthermore, placental supernatant elevated p38 and Jun N-terminal kinase (JNK) phosphorylation in both cell lines (P < 0.05). Inhibitors of JNK, ER and PR reversed MCF7 and T47D motility induced by the placenta, suggesting their involvement. CONCLUSIONS: We suggest that E(2) and progesterone contribute to cell migration away from placental areas. We hypothesize that they may increase metastatic spread to other organs in pregnancy.

Breast cancer characteristics are modified by first trimester human placenta: in vitro co-culture study.

BACKGROUND: Pregnant women with breast cancer present with a more advanced disease compared with non-pregnant women. Nevertheless, breast cancer metastasis to the placenta is rare. Trophoblast/tumor implantations share the same biochemical mediators, while only the first is stringently controlled. We hypothesized that the same mechanisms that affect/restrain placental implantation may inhibit metastatic growth in the placenta. We aimed to analyze the effects of human placenta on breast cancer cells. METHODS: First trimester human placental explants were co-cultured with MCF-7/T47D-eGFP tagged cells. Following culture, placenta/cancer cells/both were fixed, paraffin embedded and sliced for immunohistochemical analysis or sorted by their eGFP expression for future analysis. The tested parameters were: proliferation (immunohistochemistry)/cell cycle (FACS), apoptosis (immunohistochemistry/FACS), cell count/adhesion/distribution around the placenta (cell sorter, visual observation and counting), matrix metalloproteinase activity (zymogram) and estrogen receptor (ER) expression (western blotting, immunohistochemistry). RESULTS: Reduced breast cancer cell numbers (45%↓, 48%↓ for MCF-7/T47D, respectively, P < 0.05) were observed near the placenta. The placenta elevated MCF-7 sub-G1 phase and modestly elevated apoptosis (3-17%↑ for T47D/MCF-7, respectively, P < 0.05). Our findings demonstrate breast cancer cell migration from the placenta as: (i) T47D/MCF-7 cells changed their morphology to that of motile cells; (ii) elevated MMPs activity was found in the co-culture; (iii) placental soluble factors detached breast cancer cells; and (4) the placenta reduced MCF-7/T47D cells' ER expression (a characteristic of motile cells). CONCLUSIONS: MCF-7/T47D cells are eliminated from the placental surroundings. Analyzing the causes of these phenomena may suggest biological pathways for this event and raise new therapeutic targets.

Tetraspanin-induced death of myeloma cell lines is autophagic and involves increased UPR signalling.

BACKGROUND: Multiple myeloma (MM) therapy is hindered by the interaction of the heterogeneous malignant plasma cells with their microenvironment and evolving drug resistance. We have previously shown that the membranal tetraspanins, CD81 and CD82, are under-expressed in MM cells and that their reintroduction causes massive non-apoptotic death. In this study, we aimed to characterise the tetraspanin-induced MM death. METHODS: Multiple myeloma cell lines were transiently transfected with eGFP-CD81N1/CD82N1 fusion proteins and assessed for death mode by flow cytometry (propidium iodide, ZVAD-fmk, 3MA), activation of unfolded protein response (UPR), and autophagy (immunoblot, RT-PCR). RESULTS: Cell death induced by CD81N1 and CD82N1 in MM cell lines was autophagic and involved endoplasmic reticulum (ER)-stress manifested by activation of UPR pathways, PERK (protein kinase-like ER kinase) and IRE1 (inositol-requiring 1). We also established the relative X-box binding protein 1 baseline expression levels in a panel of MM cell lines and their general dependence on autophagy for survival. Timeline of UPR cascades and cell fate supported our results. INTERPRETATION: This is the first publication implicating tetraspanins in UPR signalling pathways, autophagy, and autophagic death. Integration of our findings with published data highlights the unifying dependence of MM cells on ER-Golgi homoeostasis, and underscores the potential of tetraspanin complexes and ER-stress as leverage for MM therapy.

The Role of heat shock protein 27 in extravillous trophoblast differentiation.

Trophoblast cells from placental explants differentiate in culture to extravillous trophoblast cells (EVT cells). During trophoblast differentiation heat-shock-protein-27 (HSP27) mRNA and multidrug-resistance-protein-5 (MRP5, transporter of cyclic nucleotides) expression are increased. HSP27 is a regulator of actin filaments structure and dynamic, has a role in cell differentiation and may affect NF-kB activity. In this study we aimed to assess HSP27 level in trophoblast cells and its correlation with motility and differentiation related processes [MMPs activity, nitric oxide (NO), inducible nitric oxide synthase (iNOS), proliferation and MRP5 levels]. We evaluated HSP27 expression in a first trimester human trophoblast explants model designed to assess EVT cells differentiation/migration with/without 6-mercaptopurine (6MP, an EVT inhibitor of migration). We found that HSP27 level is expressed in the nucleous and cytoplasm of non-proliferting villous-trophoblast cells (negative for Ki67) and in the cell periphery and cytoplasm of motile EVT cells. Moreover, 6MP decreased HSP27 nucleous expression that was associated with inhibited MMP2 activity and NO production. Also decreased iNOS expression and increased MRP5 mRNA levels were observed. In conclusion, HSP27 expression is modulated in concordance with migration dependent parameters in trophoblast cells.

Impaired migration of trophoblast cells caused by simvastatin is associated with decreased membrane IGF-I receptor, MMP2 activity and HSP27 expression.

BACKGROUND: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme-A reductase, the rate-limiting enzyme of the mevalonate pathway, and are used successfully in the treatment of hypercholesterolaemia. Statins are contraindicated during pregnancy. Lately, we have shown that simvastatin has adverse affects on human first trimester placental explants' proliferation and migration. The objective of the present study was to investigate the molecules involved in mediating simvastatin's effect on trophoblast cell migration. We hypothesized that simvastatin attenuates insuline-like growth factor-I (IGF-I) receptor expression (involved in trophoblast motility), matrix metalloproteinase (MMP) activities, and heat shock protein 27 (HSP27) levels (whose mRNA is actively transcribed during trophoblast differentiation) in trophoblast cells thus consequently effecting their migration. METHODS: Human placental explants were cultured above a matrigel with/without simvastatin (10 microM) for 5 days. In this model, trophoblast migrates from the villi into the matrigel. Western-blot and immunohistochemistry served for analysing HSP27 expression. Immunohistochemistry was used for assessing IGF-I receptor localization. MMPs activity was assayed by gel zymography. RESULTS: Simvastatin reduced IGF-I receptor membranal expression, MMP2 activity and HSP27 expression in trophoblast cells (P < 0.05). CONCLUSIONS: The inhibitory effect of simvastatin on trophoblast cell migration is associated with a significant decrease in the tested molecules, which probably contributes to the impaired migration.

High incidence of BRCA1-2 germline mutations, previous breast cancer and familial cancer history in Jewish patients with uterine serous papillary carcinoma.

OBJECTIVE: To test the carrier status of the three germline founder mutations in Jewish patients with uterine serous papillary carcinoma (USPC) and to evaluate its association to their personal and familial cancer records. METHODS: Retrospective analysis of histologically confirmed USPC Jewish patients diagnosed between April 1, 1997 and December 31, 2003. All cases were genetically tested for the three BRCA1-2 founder germline mutations (185delAG and 5382insC in BRCA1 and 6174delT in BRCA2). The analysis was performed on genomic DNA extracted from whole blood or paraffin embedded normal tissue of these patients, employing PCR amplification of target sequences and differential digestion with restriction enzymes. The carrier frequency was compared to the known population frequency of these mutations. RESULTS: The study group comprised 22 Jewish patients with USPC diagnosed within this timeframe. The mean age was 71.8 years (range 56-79). FIGO surgical stage distribution revealed 59% at stages III-IV. Seven USPC patients (32%) with a previous diagnosis of breast cancer were identified. Familial cancer history was recorded in 23% of the patients (four with breast cancer and one with ovarian cancer). DNA analysis revealed six BRCA1-2 germline mutation carriers (27%) as follows: three with BRCA2-6174delT, two with BRCA1-185delAG, and one with BRCA1-5382insC mutation. Three of the carriers had a previous diagnosis of breast cancer. Four carriers had familial cancer history in first-degree relative (three with breast cancer and one with ovarian cancer). CONCLUSIONS: The high rate of BRCA germline mutations in USPC patients observed in the present study, coupled with the strong personal and familial cancer history as well as the histological and clinical resemblance to the ovarian cancer, may indicate that USPC is a part or an expression of the hereditary breast-ovarian cancer syndrome. This option may have implications in our clinical recommendations for non-affected BRCA1-2 carriers.

Simvastatin has deleterious effects on human first trimester placental explants.

BACKGROUND: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMG-CoA reductase), the rate-limiting enzyme of the mevalonate pathway, and have been used successfully in the treatment of hypercholesterolaemia. Animal models have provided evidence for the teratogenic effects of statins on pregnancy outcome. Thus statins are contraindicated during pregnancy. However, conflicting data are available from inadvertent use of statins in human pregnancy. Therefore we decided to explore the effects of simvastatin on the placenta in an in vitro human placental model. METHODS: Human first trimester placental explants that were grown on matrigel were exposed to medium supplemented with simvastatin. Migration of extravillous trophoblast cells was assessed by visual observation. Proliferative and apoptotic events of the trophoblast cells were assesed by immunohistochemical examination using anti-Ki67 and anti-activated caspase-3 antibodies respectively. Hormone levels were measured. RESULTS: Simvastatin sharply inhibited migration of extravillous trophoblast cells from the villi to the matrigel (P < 0.05). Moreover, simvastatin inhibited half of the proliferative events in the villi (P < 0.05) and increased apoptosis of cytotrophoblast cells compared to control. Moreover, simvastatin significantly decreased secretion of progesterone from the placental explants (P < 0.01). CONCLUSION: Simvastatin adversely affects human first trimester trophoblast.

The effect of 6-mercaptopurine on early human placental explants.

BACKGROUND: 6-mercaptopurine (6-MP) is an antineoplastic and immunosuppressive drug. Recently, more women have received this drug during pregnancy. Animal studies have shown that 6-MP has deleterious effects on the fetus, while human data include prematurity, intrauterine growth restriction, low birth weight and malformations that occur especially when the drug is administered in the first trimester of pregnancy. OBJECTIVES: To study the effects of 6-MP on cellular functions of human trophoblast explants. METHODS: Human placental explants (5.5-9 weeks gestational age), that were grown on matrigel, were exposed to medium containing 6-MP for 5 days. Medium alone served as control. Extravillous trophoblast (EVT) cell migration assessment was performed by visual observation. Analysis of proliferating events of the trophoblast cells was assessed by immunohistochemical examination. Apoptosis was analyzed by Tunnel procedure and by anti-caspase 3 staining and hormone level by enzyme-linked immunosorbent assay. RESULTS: 6-MP inhibited migration of EVT cells from the villi to the matrigel with a lower proliferation rate and increased apoptosis of cytotrophoblast cells compared to controls. However, no significant effect of 6-MP on hormone levels was observed. CONCLUSIONS: 6-MP inhibited migration and proliferation of trophoblast cells in first-trimester human placental explant culture.

Fluorouracil induces apoptosis and surface molecule modulation of peripheral blood leukocytes.

Little is known about the direct effect of chemotherapy on normal peripheral blood leukocytes (PBL) or its contribution to leukopenia. We examined 5'-fluorouracil's (5FU) effect on PBL apoptosis and adhesion molecules' expression in a single-drug solid-tumor model. Possible apoptosis mediators were examined. The study included 32 colorectal cancer patients; apoptosis was determined by annexin-V binding and light-scatter morphology before and after drug infusion. CD18, CD11a, CD11b, and CD63 membranal levels were assayed by flow cytometry. Apoptosis was increased post-5FU administration in neutrophils (PMN), monocytes and lymphocytes (P < 0.05). Levels of Fas receptor and activated caspase 3 did not vary indicating that the process was not mediated by caspase 3 in the timeframe studied. Reduced CD63 on monocytes and decreased CD18 expression on PMN and non-apoptotic monocytes were observed (P < or = 0.05). CD11a,b expression did not vary. Decreased CD18 and CD63 levels were demonstrated in apoptotic and non-apoptotic PBL implying a more direct association with the drug itself.

Expression of tetraspanins in peripheral blood leukocytes: a comparison between normal and infectious conditions.

The role of tetraspanins is undefined, despite their detection in diverse cell types and functions. This study addresses the characterization of tetraspanin expression levels in normal peripheral blood leukocytes (PBL) and in patients with bacterial infection. Membranal and cytoplasmic expression of CD9, CD53, CD63, CD81, CD82 and CD151 in polymorphonuclears (PMN), monocytes, B and T lymphocytes was assessed using flow cytometry. Results suggested that for normal PBL, PMN are distinguished by dominant cytoplasmic CD63; monocytes and B cells prevailingly express CD53; CD82 is primarily expressed on T-cell membranes. However, a major trend of downregulation was demonstrated for the examined tetraspanins, except CD63, in all patients' PBL subtypes. Therefore, tetraspanin modulation in infections may be attributed to elevated leukocyte motility in immune reactions and this is compatible with the previous publications of tetraspanins as metastasis suppressors. This work represents the first comprehensive baseline of tetraspanin expression in normal PBL and in infectious disorders.

Tamoxifen modulates apoptotic pathways in primary endometrial cell cultures.

Clinical data indicate that tamoxifen (TAM) therapy may cause an increased risk of endometrial pathology in postmenopausal but not in premenopausal women. Molecular mechanisms of the uterotrophic activity of TAM have not been clearly established nor its relevance to apoptosis in endometrial cells. The present study was implemented to evaluate the apoptotic effect of TAM on primary endometrial cell cultures in the presence or absence of steroid hormones (SHs). A total of 14 primary endometrial cell cultures were established and maintained both with and without SHs. Cell cultures were treated for 24 h with either 20 microM TAM or 10 nM estradiol. Apoptotic cells presented in a pre-G1 peak and the expression of bcl-2 were studied using flow cytometry. All endometrial cell cultures maintained in a SH-containing environment, except one, responded to TAM by a significant increase (P = 0.03) in the pre-G1 cell fraction, indicating a proapoptotic effect. A significant (P = 0.03) reduction in the pre-G1 peak equivalent to an antiapoptotic response was observed in 6 of 13 cell cultures maintained in a SH-deficient environment. In 4 of 10 cell cultures evaluated in both media, the pre-G1 population was medium dependent. In 8 of 10 cultures evaluated for Bcl2 levels, no trend was found in either media, but a dependency on SH content was observed. Comparison between effects of TAM and estradiol demonstrated identical trends, regardless of the menstrual phase or SH content in cell environments. These results suggest that TAM acts as an estrogen agonist on endometrial tissue in both environments. We conclude that TAM modulates apoptotic pathways in primary endometrial cell cultures. The SH content in the cell environment influences the apoptotic effect of TAM and determines the propensity for a cell to undergo apoptosis or, on the contrary, to resist apoptotic death in response to TAM treatment. This is in concordance with the observed clinical risk of endometrial pathologies in postmenopausal versus premenopausal women.

Incidence of BRCA1 and BRCA2 mutations in Ashkenazi colorectal cancer patients: preliminary study.

BACKGROUND: Mutations in BRCA genes are associated with an elevated incidence of colorectal cancer (CRC). While 20% of CRC patients have a familial history of colonic malignancies, in only 5% is the genetic setting understood. Thus, a majority of these patients lack any known genetic marker. Our aim was to explore the relevance of BRCA mutations to serve as such markers in the genetic screening and counseling of CRC patients. PATIENTS AND METHODS: 136 consecutive Israeli Jewish patients with sporadic CRC were screened for BRCA "Ashkenazi mutations": 185delAG, 5382insC and 6174delT. Carrier status was evaluated employing PCR, restriction analysis, SSCP and a Pronto BRCA kit. RESULTS: We found one 185delAG and two 6174delT carriers, altogether three Ashkenazi carriers out of 87 Ashkenazi patients tested, 3.5%. No carriers were found among the Arabs and non-Ashkenazi Jews surveyed. CONCLUSIONS: Our preliminary results show elevated rates of BRCA "Ashkenazi mutations" in Ashkenazi CRC patients, suggesting their involvement in CRC carcinogenesis. An implementation of a wider study will establish the role of these mutations as genetic markers for CRC.