Marc Chaouat

Hormonal regulation of apoptosis in breast cells and tissues.

Few studies have referred to the implication of apoptotic processes following hormonal treatment. No data are available on the effects of progesterone in breast cells. In order to gain insights on the effects of the gonadal steroids and antiestrogens in breast cells, we have carried out studies on apoptosis in different breast materials. We have developed a model of normal breast cells in cultures that remain hormone-dependent. On these cells and in some hormone-dependent breast cancer cell lines (T-47-D, ZR75-1, MCF-7) we have observed an antiapoptotic effect of estradiol (E(2)) and a potent proapoptotic effect of some antiestrogens. Progestins were also proapoptotic in normal as well as in hormone-dependent breast cancer cells. In order to understand the mechanisms of these hormones on apoptosis, we studied the bcl-2 family proteins. We demonstrated that E(2) increased the antiapoptotic proteins, bcl-2 and bclx(L), whereas, the progestins drastically decreased bcl-2 expression and weakly bclx(L) levels. We investigated the mechanisms by which E(2) increased bcl-2 expression. Our results using quantitative RT-PCR showed that E(2) increased bcl-2 mRNA levels at 48 h of treatment via a transcriptional mechanism. None of the hormone treatments altered the proapoptotic protein levels, bax and bak. We also studied the in vivo expression of bcl-2 and other members of its family in biopsies of normal breast tissues according to the menstrual cycle. Bcl-2 displayed a strong cyclical variation and seemed to be the most hormone-dependent member of the family.

Abdominal dermolipectomies: early postoperative complications and long-term unfavorable results.

A retrospective study was done on a population of 258 women who had undergone surgery for abdominal dermolipectomy between January of 1991 and May of 1996. The postoperative complications and flaws seen at long-term follow-up are discussed. The surgical techniques used, with or without lipoaspiration, were the infraumbilical plasty and full plasties with horizontal or inverted T scars. Six types of postoperative complications were noted: hemorrhage in 1.2 percent, lymphorrhea in 10.9 percent, infection in 7 percent, skin necrosis in 6.6 percent, secondary dehiscence of the scar in 2.3 percent, and thromboembolic accidents in 1.2 percent. No significant difference was found in the rate of necrosis development between patients who did and did not undergo lipoaspiration. However, a statistically significant difference was seen in the rate of skin necrosis between the T-type plasty (35.5 percent) and the other two procedures (1.43 percent for infraumbilical plasties and 4.60 percent for full plasties with horizontal scar). With regard to the flaws found at long-term follow-up, the rate of above-scar fat folds and/or dog-ears was 27.9 percent, and the rate of defective scars was 26 percent. No significant difference was found with regard to the rate of flaws. The rate of all secondary surgical procedures was 29.1 percent, but performance of secondary procedures depended on the willingness of the patient and on the surgeons judgment. Abdominoplasty procedures involve a high risk of early complications. The rate of skin necrosis is clearly augmented in cases of T-type plasty. The need for secondary surgical correction is frequent, and the patient should be reminded of this possibility during preoperative consultation.

In vitro studies of tibolone in breast cells.

OBJECTIVE To investigate the effects of tibolone and its main metabolites on breast homeostasis. DESIGN In vitro studies in primary cultures of normal breast cells and in breast cancer cell lines. SETTING Hospital-based academic research center. PATIENT(S) Human breast cells were obtained from women undergoing surgery for hypermastia. Breast cancer cell lines (MCF-7, T47-D, and ZR75-1) were routinely obtained from subcultures. INTERVENTION(S) Cells were incubated with tibolone, its various metabolites, the pure pregnane Org 2058, and the androgen dihydrotestosterone. MAIN OUTCOME MEASURE(S) Proliferation was determined by using a morphometric growth index, apoptosis by using morphologic analysis and flow cytometry, and antiapoptotic proteins bcl-2 and bclx(L) by using Western blot assay. Activity of 17beta-hydroxysteroid dehydrogenase was measured as an epithelial differentiation marker. RESULT(S) Tibolone and its delta(4) isomer were antiproliferative in normal breast cells. Tibolone and its delta(4) isomer increased apoptosis in breast cells. These proapoptotic effects were at least partially mediated through decreased expression of the antiapoptotic proteins bcl-2 and bclx(L). An increase in HSD activity was observed after tibolone administration. CONCLUSION(S) Tibolone is antiproliferative and proapoptotic and induces differentiation in normal breast cells. It is also proapoptotic in breast cancer cell lines.

The Neurotensin Receptor-1 Pathway Contributes to Human Ductal Breast Cancer Progression

Background The neurotensin (NTS) and its specific high affinity G protein coupled receptor, the NT1 receptor (NTSR1), are considered to be a good candidate for one of the factors implicated in neoplastic progression. In breast cancer cells, functionally expressed NT1 receptor coordinates a series of transforming functions including cellular migration and invasion. Methods and Results we investigated the expression of NTS and NTSR1 in normal human breast tissue and in invasive ductal breast carcinomas (IDCs) by immunohistochemistry and RT-PCR. NTS is expressed and up-regulated by estrogen in normal epithelial breast cells. NTS is also found expressed in the ductal and invasive components of IDCs. The high expression of NTSR1 is associated with the SBR grade, the size of the tumor, and the number of metastatic lymph nodes. Furthermore, the NTSR1 high expression is an independent factor of prognosis associated with the death of patients. Conclusion these data support the activation of neurotensinergic deleterious pathways in breast cancer progression.

Antiestrogens are pro‐apoptotic in normal human breast epithelial cells

Estrogens promote cell proliferation in normal and transformed mammary epithelial cells by inducing expression of hormone‐responsive genes involved in the cell cycle. The action of antiestrogens is therefore central in regard to their potent inhibitory effects on estrogen‐induced cell growth. We used normal human epithelial breast cells from primary cultures (HBE cells) to study hormonal (estrogen and antiestrogen) regulation on 3 key proteins involved in the apoptotic process: Bcl‐2, p53 and caspase‐3. The mammary adenocarcinoma cell line, MCF‐7, was also used to study the molecular regulation of Bcl‐2. In both HBE and MCF‐7 cells, we found that estradiol (E2) induced an increase in Bcl‐2 mRNA levels. This effect was counteracted in the presence of a pure antiestrogen, ICI 182780 (ICI). Alone, ICI did not modify either the Bcl‐2 protein or mRNA levels in HBE cells, whereas in MCF‐7, a strong downregulation of Bcl‐2 mRNA was observed. In parallel, in HBE cells, we observed that E2 caused a decrease in p53 and caspase‐3 protein levels, whereas ICI alone increased p53 and caspase‐3 protein levels. The ICI effects on p53 and caspase‐3 were partially counteracted by E2. Under the same experimental conditions, ICI exerts a potent pro‐apoptotic effect, which was not counteracted by E2. In contrast, 4‐hydroxytamoxifen was slightly weaker as a pro‐apoptotic agent in HBE cells and its effects were reversed by E2. We demonstrate that in HBE cells, ICI reverses the anti‐apoptotic action of E2 and alone acts as a highly potent pro‐apoptotic molecule. These results provide new insight into treatment for breast cancer prevention.

Reducing the spread of Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus on a burns unit through the intervention of an infection control bundle §

Methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii are major nosocomial pathogens in burns units. We investigated the impact of an infection control bundle on the incidence of nosocomial MRSA and A. baumannii in our burns unit, comparing a pre-intervention period (December 2006-August 2008) with an intervention period (September 2008-December 2009). The bundle comprised regular hydrogen peroxide vapour (HPV) disinfection of the rooms following discharge of patients colonized or infected by multidrug-resistant bacteria, pre-emptive cohort isolation of newly admitted patients before being proven culture negative, cohorting of colonized or infected patients, installation of two air disinfection systems in the corridors of the unit and improvement of material storage. We also investigated the microbiological efficacy of HPV disinfection by sampling the environment before and after HPV treatments. HPV disinfection eliminated pathogens from the environment and significantly reduced total bacterial surface counts, and total fungal air and surface counts, on both a unit and room scale. The incidence of nosocomial MRSA infection or colonization fell by 89.3% from 7.22 to 0.77 cases/1000 patient days (p<0.0001) and A. baumannii fell by 88.8% from 6.92 to 0.77 cases/1000 patient days (p=0.002) in the intervention period with no further outbreaks of these organisms occurring in this period. The infection control bundle resulted in a significant reduction in the incidence of nosocomial MRSA and A. baumannii in our burns unit and prevented further outbreaks of these organisms.

Mechanical properties of rat thoracic and abdominal aortas

Mechanical properties of abdominal and thoracic arteries of 2mm in diameter were determined from adults Wistar rats. A tensile testing instrument was used to obtain stress/strain curves with arteries immersed in physiological buffer at 37 degrees C. A displacement was applied on all arteries with various frequencies (1-7.5Hz) and strains (5-60%). From each curve a Young modulus was obtained using a mathematical model based on a nonlinear soft tissue model. No influence of frequency on modulus was evidenced in the tested range. Abdominal aortas, which were found slightly thicker than thoracic aortas, were characterized by a higher modulus. Due to the interest of decellularized biological materials, we also used SDS/Triton treated arteries, and found that the chemical treatment increased modulus of thoracic arteries. Tensile tests were also performed on thoracic aortas in the longitudinal and transversal directions. Longitudinal moduli were found higher than transversal moduli and the difference could be related to the longitudinal orientation of collagen fibers. These data and mathematical model seem useful in the design of new vascular synthetic or biological prostheses for the field of tissue engineering.

The scalp is an advantageous donor site for thin-skin grafts: a report on 945 harvested samples.

Background: Thin-skin grafts taken from the thigh or buttock take a long time to heal and leave permanent scars. Methods: The authors conducted a retrospective study based on their experience with 945 thin-skin grafts (0.2 mm) taken from the scalps of 757 adult patients between January of 1999 and December of 2003. Results: Of the 757 patients, 89 had grafts taken repeatedly from the scalp. The mean healing time was 6.2 days for a single harvest and 10.2 days for repeated (same hospitalization) harvests. During follow-up, eight patients had microalopecia and three developed “concrete scalp deformity.” Of these 11 patients, eight had undergone repeated harvests. None of the other patients had any scarring; they were completely healed by day 15. Conclusions: The results of this study confirm the rapidity of scalp healing compared with other donor sites. Providing patients with clear, detailed explanations helps minimize the psychological impact of having their heads shaved, and a rigorous technique can contain the two major potential risks: hemorrhage and alopecia. The adult scalp seems to be a donor site to be exploited whenever possible.

Retrospective analysis of photographic evaluation of burn depth

PURPOSE OF THE STUDY Evaluation of burn depth is an essential and difficult step that conditions surgical or non-surgical treatment. The purpose of the study is to evaluate the opportunity to diagnose burn depth only with initial photography of the burn. METHOD For all patients admitted to our burn unit between January 2002 and March 2008, we performed a retrospective analysis of burn depth based on a photographic evaluation. Blinded photos were submitted to three experienced surgeons who were asked if the burns required a graft or not. The diagnosis done by photography evaluation was then compared to initial diagnosis and treatment. MAIN FINDINGS Out of 911 patients photography analysed, the photographic evaluation was equivalent to clinical evaluation in 76% of the cases. The sensitivity and specificity of the photographic evaluation were, respectively, 0.77 and 0.75. The main evaluation errors were in intermediate burns (29.6% of errors) and were more often due to overestimation of the depth. In 75% of cases, there was a full agreement between 3 surgeons (683/911). A secondary analysis excluding electrical and chemical injuries showed an improvement of predictability. CONCLUSION Even though a photographic analysis cannot replace clinical examination, photographic evaluation may be one option to consider for an early distance diagnosis.

Ulipristal acetate does not impact human normal breast tissue

BACKGROUND Antiprogestins are of growing interest for the development of new treatments in the gynecological field. Ulipristal acetate (UPA) is a progesterone receptor (PR) modulator considered for long-term administration in contraception and is currently being registered for the treatment of uterine fibroids. In light of the influences of hormonal dysfunction in breast pathologies, the secondary consequences of chronic UPA therapy need to be established. The aim of this study was to determine UPA actions mediated by PR and glucocorticoid receptor (GR) in normal and transformed breast. METHODS UPA, progesterone (P) and dexamethasone (DEX) effects were observed on PR and GR responsive genes and on proliferation and apoptosis of normal human breast epithelial (HBE) and breast cancer cells. Human normal breast tissue samples were xenografted in athymic mice and treated with estradiol (E2), or E2 + P, or E2 + P + UPA. RESULTS Analysis of PR and GR reporter gene transactivation and their respective endogenous target genes indicated that UPA exerted anti-progestational and anti-glucocorticoid activity in both types of cells with a more pronounced effect in cancer cells. When combined with P or DEX, UPA limits the proliferation of HBE cells but increases growth in breast cancer cell lines. UPA administration had no impact on the mitotic index on xenografted human breast tissue exposed to gonadal hormones at similar concentrations to those present in normal women. CONCLUSIONS Although further clinical trials are required to confirm that the results from our experimental models can be extrapolated to women treated with UPA, they suggest that such treatment would not be deleterious to normal breast tissue at least for a cycle (28 days) of continuous administration.