Apoptosis in the human female reproductive tract

Effect of progesterone and first evidence about allopregnanolone action on the progression of epithelial human ovarian cancer cell lines

Ovarian carcinoma is one of the most common cause of death by gynecologic cancer. Several epidemiological and in vitro studies have shown controversial data about progesterone effects in ovarian cancer. Progesterone can be converted in its active metabolite, allopregnanolone, its effects in ovarian cancer are still unknown. Previously, we demonstrated that allopregnanolone modifies ovarian morphophysiology, being able to alter critical process of tumor development such as proliferation, apoptosis and angiogenesis. Taking into account these antecedents, we investigated the effect of progesterone and allopregnanolone on proliferation, apoptosis, clonogenic capacity and migration on two epithelial human ovarian cancer cell lines, IGROV-1 and SKOV-3. To this end, IGROV-1 and SKOV-3 cells were exposed to a range of progesterone and allopregnanolone concentrations (10^-11 to 10^-5 M) for 72 h. Proliferation was analyzed by MTT and Ki67 expression. Apoptosis was measured by immunocytochemistry of cleaved caspase 3. Clonogenic capacity was evaluated by counting colonies. Migration was analyzed by wound assay. We found that allopregnanolone increased proliferation and Ki67 expression respect to control on IGROV-1 cells, while expression of cleaved caspase 3 did not change in any cell line studied. IGROV-1 clonogenic capacity was also increased by allopregnanolone treatment. Both steroids, progesterone and allopregnanolone, increased IGROV-1 migration in a concentration dependent manner. None of the steroids tested modified SKOV-3 biological behavior analized. This is the first evidence that allopregnanolone, a progesterone metabolite, affects critical events in tumor development of human epithelial ovarian cancer. These results could have an impact in the future in clinic diagnosis, prognosis and treatment of ovarian cancer patients. The regulation of progesterone and allopregnanolone steroideogenesis and their molecular mechanisms might be considered as potential therapeutic tool in ovarian cancer.

Cell-free DNA induced apoptosis of granulosa cells by oxidative stress

BACKGROUND

Cell-free DNA is a DNA fragment that is produced by cell apoptosis which can affect the micro-environment of cell apoptosis. The levels of Cell-free DNA have been associated with successful rate of in vitro fertilization-embryo transfer (IVF-ET) and embryonic development. Our aim is to determine the relationship between cell-free DNA and embryo quality. The mechanisms of cell-free DNA in granulose and the apoptosis will be determined also.

METHODS

The study enrolled patients who were undergone IVF for the first time and grouped the patients as pregnant (n=130) and non-pregnant (n=59). The relationship was determined by statistical analysis between the levels of cell-free DNA in the follicular fluid and clinical data of IVF patients. Flow cytometry was done to detect the rate of granulosa cell apoptosis and intracellular reactive oxygen species (ROS) level. Western blotting and fluorescent quantitative PCR detected the apoptosis-related gene expressions.

RESULTS

Clinical data statistics showed that cell-free DNA levels were positively correlated with granulosa cell apoptosis and negatively correlated with embryo quality and pregnancy rates. High levels of cell-free DNA lead to increased ROS in granulosa cells and activated caspase through Fas/FasL that induced apoptosis.

CONCLUSION

High levels of cell-free DNA triggers granulosa cell apoptosis and influences oocyte maturation embryo development and pregnancy rates in IVF treatments. Cell-free DNA can be as a secondary criteria and predictive marker for the quality control of IVF embryo.

Apoptotic and Mitotic Index in Squamous Cell Carcinomas and Premalignant Lesions of the Uterine Cervix

The aim of this study was to determine the frequency of apoptotic and mitotic cells in different grades of premalignant lesions and in different stages of squamous cell carcinoma (SCC) of the uterine cervix. The apoptotic and mitotic indices (A! and MI) of 55 H&E-stained sections of cervical intraepithelial neoplasia (CIN) and 30 SCCs were evaluated in light microscopy by a morphometric method. Twenty, 16, and 19 of 55 CIN cases were classified in CIN I, CIN II, and CIN III group, respectively. No apoptosis was observed in the normal epithelium next to the dysplastic mucosa. There was no statistically significant difference between CIN I and CIN II as well as CIN II and CIN III groups in terms of apoptotic and mitotic cell counts. Mitotic cell counts were found significantly higher in CIN III group when compared with CIN I and CIN II groups together. There was no statistically significant difference in the apoptotic and mitotic cell counts between nonkeratinizing and keratinizing types of SCC. In the SCC group, apoptotic cell counts did not show significant difference between tumor stages. But mitotic counts were significantly higher in advanced stage tumors. The SCC group showed significantly higher mitotic and apoptotic cell counts when compared with preneoplastic lesions. This study suggests that apoptotic function is not altered during progressive stages of dysplastic change in cervical epithelium, while proliferation is triggered only in late stages of dysplasia. Both apoptosis and mitosis are markedly increased in progression to malignancy in cervix epithelium. Mitotic cell counts may be helpful in predicting the extent of the disease in SCC. Resistance of cell death by apoptosis after invasion may accelerate the net growth of the tumor resulting in advanced disease.

Cell-free DNA in Human Follicular Microenvironment: New Prognostic Biomarker to Predict in vitro Fertilization Outcomes

Cell-free DNA (cfDNA) fragments, detected in blood and in other biological fluids, are released from apoptotic and/or necrotic cells. CfDNA is currently used as biomarker for the detection of many diseases such as some cancers and gynecological and obstetrics disorders. In this study, we investigated if cfDNA levels in follicular fluid (FF) samples from in vitro fertilization (IVF) patients, could be related to their ovarian reserve status, controlled ovarian stimulation (COS) protocols and IVF outcomes. Therefore, 117 FF samples were collected from women (n = 117) undergoing IVF/Intra-cytoplasmic sperm injection (ICSI) procedure and cfDNA concentration was quantified by ALU-quantitative PCR. We found that cfDNA level was significantly higher in FF samples from patients with ovarian reserve disorders (low functional ovarian reserve or polycystic ovary syndrome) than from patients with normal ovarian reserve (2.7 ± 2.7 ng/μl versus 1.7 ± 2.3 ng/μl, respectively, p = 0.03). Likewise, FF cfDNA levels were significant more elevated in women who received long ovarian stimulation (> 10 days) or high total dose of gonadotropins (≥ 3000 IU/l) than in women who received short stimulation duration (7–10 days) or total dose of gonadotropins < 3000 IU/l (2.4 ± 2.8 ng/μl versus 1.5 ± 1.9 ng/μl, p = 0.008; 2.2 ± 2.3 ng/μl versus 1.5 ± 2.1 ng/μl, p = 0.01, respectively). Finally, FF cfDNA level was an independent and significant predictive factor for pregnancy outcome (adjusted odds ratio = 0.69 [0.5; 0.96], p = 0.03). In multivariate analysis, the Receiving Operator Curve (ROC) analysis showed that the performance of FF cfDNA in predicting clinical pregnancy reached 0.73 [0.66–0.87] with 88% specificity and 60% sensitivity. CfDNA might constitute a promising biomarker of follicular micro-environment quality which could be used to predict IVF prognosis and to enhance female infertility management.

Apoptosis- and endoplasmic reticulum stress-related genes were regulated by estrogen and progesterone in the uteri of calbindin-D(9k) and -D(28k) knockout mice

Calcium (Ca(2+)) is an important regulator of apoptotic signaling. Calbindin-D(9k) (CaBP-9k) and -D(28k) (CaBP-28k) have a high affinity for Ca(2+) ions. Uterine calbindins appear to be involved in the regulation of myometrial activity by intracellular Ca(2+). In addition, uterine calbindins are expressed in the mouse endometrium and are regulated by steroid hormones during implantation and development. The aim of the present study was to evaluate the regulation of apoptosis in the uteri of CaBP-9k, CaBP-28k, and CaBP-9k/28k knockout (KO) mice. Our findings indicated that Bax protein was enhanced in the uteri of CaBP-28k and CaBP-9k/28k KO mice compared to wild-type (WT) and CaBP-9k KO mice, but no difference was observed in Bcl-2 protein expression. The expressions of caspase 3, 6, and 7 proteins were higher in both CaBP-28k and CaBP-9k/28k KO mice than in WT and CaBP-9k KO mice. These results suggest that the absence of CaBP-28k increases apoptotic signaling. We also investigated the expression of endoplasmic reticulum (ER) stress genes by Western blot analysis in calbindin KO mice. C/EBP homologous protein and immunoglobulin heavy chain-binding protein protein levels were elevated in CaBP-28k KO mice compared to WT mice. When immature mice were treated with 17β-estradiol (E2) or progesterone (P4) for 3 days, we found that the expressions of Bax and caspase 3 protein were increased by E2 treatment in WT and CaBP-9k KO mice, and by P4 treatment in CaBP-28k KO mice. These results indicate that CaBP-28k blocks the up-regulation of apoptosis-related genes and ER stress genes, implying that CaBP-28k may decrease the expression of genes involved in apoptosis and ER stress in murine uterine tissue.

Polymorphisms in the CASP8 gene and the risk of epithelial ovarian cancer

OBJECTIVE

The CASP8 gene plays a central role in the apoptotic pathway and is therefore a plausible cancer susceptibility gene. However, the precise role of the CASP8 gene in epithelial ovarian cancer carcinogenesis is unclear. Therefore, we analyzed the correlation between single nucleotide polymorphisms (SNPs) and haplotypes in CASP8 and the risk and clinical characteristics of epithelial ovarian cancer (EOC) in the Chinese population.

SUBJECTS AND METHODS

Eight tag SNPs were identified using the MassARRAY system to genotype 37 genetic polymorphisms around and in the CASP8 gene in 100 unrelated, healthy females. Then, a case-control study of 218 EOC patients and 285 controls who were matched on residence, age and race was conducted using these 8 tag SNPs.

RESULTS

The risk of developing EOC was significantly decreased in association with CASP8 rs3834129 ins>del (odds ratio (OR)(del/del)=0.129, 95% confidence interval (95% CI): 0.038-0.439; OR(ins/del)=0.769, 95% CI, 0.534-1.108), rs3769827 T>C (OR(C/C)=0.187, 95% CI: 0.070-0.500; OR(T/C)=0.729, 95% CI: 0.505-1.052), rs6704688 C>T (OR(T/T)=0.344, 95% CI, 0.168-0.707; OR(C/T)=0.802, 95% CI, 0.552-1.166), and with the del-C-T haplotype of these 3 SNPs (OR=0.615, 95% CI: 0.453-0.8363). Moreover, a notably later onset was significantly associated with the rs3834129 ins/del+del/del and the rs3769827 T/C+C/C genotypes (p<0.0001).

CONCLUSIONS

Genetic variants of the CASP8 gene protect against EOC carcinogenesis and delay the age of EOC onset. Furthermore, these protective effects may be due to the dysfunctional expression of caspase-8 caused by the -652 6N del variant in the promoter.

The importance of folate, zinc and antioxidants in the pathogenesis and prevention of subfertility

Current treatments of subfertile couples are usually empiric, as the true cause of subfertility often remains unknown. Therefore, we outline the role of nutritional and biochemical factors in reproduction and subfertility. A literature search was performed using MEDLINE, Science Direct and bibliographies of published work with both positive and negative results. The studies showed that folate has a role in spermatogenesis. In female reproduction, folate is also important for oocyte quality and maturation, implantation, placentation, fetal growth and organ development. Zinc has also been implicated in testicular development, sperm maturation and testosterone synthesis. In females, zinc plays a role in sexual development, ovulation and the menstrual cycle. Both folate and zinc have antioxidant properties that counteract reactive oxygen species (ROS). Thiols, such as glutathione, balance the levels of ROS produced by spermatozoa and influence DNA compaction and the stability and motility of spermatozoa. Oocyte maturation, ovulation, luteolysis and follicle atresia are also affected by ROS. After fertilization, glutathione is important for sperm nucleus decondensation and pronucleus formation. Folate, zinc, ROS and thiols affect apoptosis, which is important for sperm release, regulation of follicle atresia, degeneration of the corpus luteum and endometrial shedding. Therefore, the concentrations of these nutrients may have substantial effects on reproduction. In conclusion, nutritional and biochemical factors affect biological processes in male and female reproduction. Further research should identify pathways that may lead to improvements in care and treatment of subfertility.

Changed Bcl:Bax ratio in endometrium of patients with unexplained infertility

Apoptosis has been shown to be an important regulator of endometrial function during the menstrual cycle and implantation. Recently, some possible implantation defects were identified in patients with unexplained infertility. In this study, we investigated the role of spontaneous apoptosis, which is regulated by death regulatory genes, such as Bcl-2, Bax, p53, and isoenzymes of nitric oxide synthases; eNOS and iNOS during the implantation window in women with unexplained infertility. Endometrial samples were evaluated from fertile (n=15) and unexplained-infertile women (n=15) during post-ovulatory 7th or 8th day of their menstrual cycles. Apoptotic cells were detected using the dUTP nick-end labelling assay and Bcl-2, Bax, p53, iNOS and eNOS were assessed immunohistochemically. Reduced apoptotic cells, weak immunoreactivity of p53 and strong immunoreactivity of Bcl-2 were observed in the unexplained-infertile group compared with the fertile group (p<0.001). Bax intensity was similar in both groups. While weak iNOS immunoreactivity was detected in both groups, moderately increased eNOS immunoreactivity was observed in infertile cases. Spontaneous apoptosis is reduced in the endometrium of unexplained-infertile women, and is associated with the changed Bcl-2:Bax ratio. This finding may be a contributing factor to defective implantation causing infertility in this group of patients.

Role of Lipid Peroxidation in the Epidemiology and Prevention of Breast Cancer

We have recently proposed a common mechanistic pathway by which obesity and hypertension lead to increased renal cell cancer risk. Our hypothesis posits lipid peroxidation, which is a principal mechanism in rodent renal carcinogenesis, as an intermediate step that leads to a final common pathway shared by numerous observed risks (including obesity, hypertension, smoking, oophorectomy/hysterectomy, parity, preeclampsia, diabetes, and analgesics) or protective factors (including oral contraceptive use and alcohol) for renal cell cancer [Cancer Causes Control 2002;13:287-93]. During this exercise, we have noticed how certain risk factors for renal cell carcinoma are protective for breast cancer and how certain protective factors for renal cell carcinoma increase risk for breast cancer. Parity and oophorectomy, for example, are positively associated with renal cell carcinoma but are negatively associated with breast cancer. Similarly, obesity and hypertension are positively associated with renal cell carcinoma, but obesity is negatively associated with breast cancer in premenopausal women and hypertension during pregnancy is negatively associated with breast cancer. Furthermore, alcohol intake, negatively associated with renal cell carcinoma, is also positively associated with breast cancer. We propose here the possibility that lipid peroxidation may represent a protective mechanism in breast cancer. Although this runs counter to the conventional view that lipid peroxidation is a process that is harmful and carcinogenic, we present here the chemical and biological rationale, based on epidemiologic and biochemical data, which may deserve further consideration and investigation.

Apoptosis and active caspase-3 expression in human granulosa cells

OBJECTIVE

To document the expression of activated forms of caspase-3 in human granulosa cells.

DESIGN

Laboratory study.

SETTING

In vitro fertilization (IVF) laboratory of the Split University Hospital and laboratory of the Department of Anatomy, Histology, and Embryology.

PATIENT(S)

Ovarian tissues were obtained from women undergoing hysterectomy/ovariectomy for benign conditions and human granulosa cells were obtained from women undergoing oocyte retrieval for IVF.

INTERVENTION(S)

Immunostaining of tissue sections and cell smears using antibody to active caspase-3 and terminal deoxynucleotidyl transferase (TdT) assay (TUNEL) for detection of internucleosomal DNA fragmentation.

MAIN OUTCOME MEASURE(S)

Microscopic evaluation to assess the presence and cellular co-localization of active caspase-3 and TUNEL-positive cells.

RESULT(S)

In human ovarian tissue, no apoptosis was observed in primordial and primary follicles. Apoptosis in granulosa cells was detected only in atretic antral follicles. Granulosa cells classified as apoptotic on the basis of their morphologic features contained a single condensed nucleus, multiple nuclear fragments, or apoptotic bodies. All apoptotic granulosa cells expressed active caspase-3, but only few contained fragmented DNA detected with the TUNEL method. The expression of active caspase-3 was also demonstrated in human granulosa cells of preovulatory follicles obtained from patients undergoing IVF.

CONCLUSION(S)

Caspase-3 dependent apoptosis occurs in human granulosa cells and activates when follicles begin to leave the resting pool. After initial formation of the antrum, activation of caspase-3 is a normal physiologic process of the follicle during atresia and luteinization. Higher numbers of granulosa cells positive with caspase-3 than cells positive with TUNEL suggest an earlier activation of caspase-3 compared with the DNA fragmentation detected by TUNEL assay and also a longer detection period of caspase-3 than DNA fragmentation in apoptotic granulosa cells.

Cyr61 suppresses growth of human endometrial cancer cells

Cyr61 (CCN1) is a member of the CCN protein family; these secreted proteins are involved in diverse biological processes such as cell adhesion, angiogenesis, apoptosis, and either growth arrest or growth stimulation depending on the cellular context. We studied the role of Cyr61 in endometrial tumorigenesis. Levels of Cyr61 were decreased in endometrial tumors compared with normal endometrium. Knockdown of Cyr61 expression by RNA interference in a well differentiated endometrial adenocarcinoma cell line (Ishikawa) stimulated its cellular growth. Conversely, overexpression of the protein in the undifferentiated AN3CA endometrial cancer cell line decreased their growth concurrently with increased apoptosis in liquid culture. These same cells had decreased clonogenic capacity and a nearly complete loss of tumorigenicity in vivo. Furthermore, partially purified Cyr61 suppressed growth of endometrial cancer cells. The increased apoptosis in these endometrial cancer cells with forced overexpression of Cyr61 was associated with elevated expression of the pro-apoptotic proteins Bax, Bad, and TRAIL (tumor necrosis factor receptor-associated ligand). Cyr61-induced caspase-3 activation and depolarization of mitochondrial membrane. In summary, endometrial cancer cells have decreased expression of Cyr61 compared with normal endometrium, and this lowered expression may provide the transformed cells a growth advantage over their normal counterpart.

Does granulosa cell apoptosis have a role in the etiology of unexplained infertility?

OBJECTIVE(S)

To compare granulosa cell apoptosis in patients with unexplained infertility and tubal factor. Accelerated granulosa cell apoptosis may be the cause of unexplained infertility.

STUDY DESIGN

Setting was IVF-ET Unit of Cerrahpasa Medical Faculty, Istanbul University. GnRH analogs and gonadotropins were used for ovulation induction in patients with unexplained infertility (n=15) and tubal factor (n=15) undergoing in vitro fertilization and embryo transfer (IVF-ET) procedures. Following HCG injection and follicular aspiration, apoptosis of granulosa cells was assessed using the in situ DNA nick end labelling method and apoptosis rate was further determined by flow cytometry. Apoptosis rates were compared between two groups. Mann-Whitney's U-test and Student's t-test were used for statistics.

RESULTS

Apoptosis rate was significantly higher in the unexplained infertility group (33.20 +/- 35.62% versus 10.10 +/- 17.23%).

CONCLUSION(S)

Granulosa cell apoptosis seems to have a role in the etiology of unexplained infertility.

Effects of a progestogen on normal human breast epithelial cell apoptosis in vitro and in vivo

Many investigators have reported cyclic proliferation of normal human breast epithelial cells. A delicate balance between proliferation and apoptosis (programmed cell death) ensures breast homeostasis. Both the follicular and luteal phases of the menstrual cycle are characterized by proliferation, whereas apoptosis occurs only at the end of the latter phase. In this study, we observed that the withdrawal of a synthetic progestin (nomegestrol acetate or NOMAC), but not continuous treatment with it, induced apoptosis of normal human breast epithelial cells in vitro and in women who applied NOMAC gel to their breasts. Furthermore, this apoptotic response was specific to normal breast cells, since withdrawal of NOMAC did not induce apoptosis of tumoral T47D cells in vitro or of fibroadenoma cells in women. These observations open up new perspectives in the prevention of hyperplasia and breast cancer.

Mitigation of avian reproductive tract function by Salmonella enteritidis producing high-molecular-mass lipopolysaccharide

Hens were infected with a wild-type Salmonella enteritidis and its wzz mutant, which lacked the ability to make high-molecular-mass lipopolysaccharide (LPS), in six experiments paired by dosage and route of exposure. Involution of the reproductive tract occurred in 86% of hens that were injected subcutaneously with 108 cfu of the wild-type strain, but none did so when injected with the wzz mutant. In spite of the lack of a specific effect on the reproductive tract, infection of hens with the mutant produced more contaminated eggs and heterophilic granulomas in developing ova (yolks) than wild type; thus, overall, the mutant appeared to be more virulent except after intravenous injection. The mutant also decreased shell quality more often than wild type, regardless of dosage or route of infection. These results suggest that egg-contaminating Salmonella enteritidis that produces high-molecular-mass LPS mitigates signs of illness in poultry by altering the response of the avian reproductive tract to infection, but without altering the incidence of egg contamination following bacteraemia. Further research is warranted to determine whether analyses of shell quality might aid in identification of flocks at risk of producing contaminated eggs.

Oral contraceptives suppress cell proliferation and enhance apoptosis of eutopic endometrial tissue from patients with endometriosis

OBJECTIVE

To evaluate the effects of administering combination oral contraceptives (COCs) to patients with endometriosis on the regulation of cell growth in the eutopic endometrium.

DESIGN

Prospective study.

SETTING

Research institute and clinical fertility center.

PATIENT(S)

Thirteen women with untreated endometriosis and 13 controls.

INTERVENTION(S)

Biopsy specimens of the eutopic endometrium were obtained from all subjects. Apoptosis, cell proliferation, and Bcl-2 and Bax expression were examined at the epithelial and stromal levels in the eutopic endometrium from patients with endometriosis before and after 30 days of daily exposure to COCs and from controls.

MAIN OUTCOME MEASURE(S)

Apoptotic cells were detected by using the dUTP nick-end labeling assay; Ki-67, Bcl-2, and Bax expressions were assessed by using immunohistochemical techniques.

RESULT(S)

After exposure to COCs, apoptosis was significantly increased in the eutopic endometrium compared with before COC administration, both at epithelial and stromal levels. Cell proliferation was significantly lowered by COCs.

CONCLUSION(S)

COCs showed a positive effect on patients with endometriosis by down-regulating cell proliferation and enhancing apoptosis in the eutopic endometrium.

Expression of p53 in luminal and glandular epithelium during the growth and regression of rat uterus during the estrous cycle

It has been well recognized that epithelial cells of the rat endometrium cyclically proliferate and die during the estrous cycle. The aim of the present study was to determine p53 expression pattern and correlate it with the the apoptotic pattern of epithelial cells of the rat uterus during the estrous cycle. The p53 mRNA and protein expression pattern was assessed by in situ hybridization and immunohistochemistry. The apoptotic index was determined by using terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and electron microscopy. The highest p53 mRNA content, detected by in situ hybridization, was observed on the metestrus day both in the luminal and the glandular epithelia. During this period both epithelia presented high proliferation. The content of p53 mRNA markedly decreased in the following days, presenting its minimal values on the estrus day. The highest number of p53 immunopositive nuclei, in both the luminal and the glandular epithelia, was also detected on the metestrus day, while the lowest one was found on estrus day. On the proestrus day, p53 protein was predominantly detected in the glandular epithelium. However, on the estrus day, p53 protein was detected both in the nuclei and in the cytoplasm of luminal epithelial cells, predominantly in the cytoplasm. The highest apoptotic index in both the luminal and the glandular epithelia was observed on the estrus day whereas the lowest one was observed on the proestrus day. The apoptotic index values were higher in the luminal than in the glandular epithelia. The overall results indicate that p53 expression at both mRNA and protein levels is higher on the metestrus day when the apoptotic index is low. This suggests that p53 should play an important physiological role during proliferative phases of the estrous cycle in the rat uterus.

Macrophages, oxidation, and endometriosis

Retrograde menstruation has been suggested to be the cause for the presence of endometrial cells in the peritoneal cavity. However, little is known about the events that lead to the adhesion and growth of these cells that ultimately result in endometriosis, considering the fact that the disease occurs only in certain women despite the common occurrence of retrograde menstruation in most women. We postulate that, in normal women, the endometrial cells and tissue that arrive in the peritoneal cavity during menstruation are effectively removed by macrophages that are chemoattracted and become resident tissue macrophages in the peritoneal cavity. In contrast, the peritoneal macrophages in women with endometriosis are nonadherent and ineffectively scavenged, resulting in the sustained presence and growth of the endometrial cells. We also postulate that the peritoneal fluid is not a passive reservoir of the factors secreted by cells of the peritoneum, but actively promotes endometriosis. The peritoneal fluid is rich in lipoproteins, particularly low-density lipoprotein, which generates oxidized lipid components in a macrophage-rich inflammatory milieu. The oxidants exacerbate the growth of endometriosis by inducing chemoattractants such as MCP-1 and endometrial cell growth-promoting activity. We provide evidence for the presence of oxidative milieu in the peritoneal cavity of women with endometriosis, the nonscavenging properties of macrophages that are nonadherent, and the synergistic interaction between macrophages, oxidative stress, and the endometrial cells. For example, the peritoneal fluid lipoproteins of subjects with endometriosis have increased the propensity to undergo oxidation as compared with plasma lipoproteins, and the subjects also have increased titer of autoantibodies to oxidatively modified proteins. If the oxidative proinflammatory nature of the peritoneal fluid is an important mediator of endometriosis growth, anti-inflammatory agents and antioxidants might afford protection against endometriosis.

Abnormal cervicovaginal smears due to endometriosis: a continuing problem

Endometriosis may be challenging when identified on cervicovaginal smears (CVS), leading to an incorrect interpretation of high-grade squamous intraepithelial lesion (HSIL), or atypical glandular cells of undetermined significance (AGUS) including adenocarcinoma in situ (AIS). Awareness of cervical endometriosis, particularly in predisposed patients, is crucial for a correct diagnosis. While cervical endometriosis has been reported to be a diagnostic pitfall of glandular abnormalities, its characteristic features are still not well-established. This may partially be attributed to the varied cytomorphologic features endometriosis shows, depending on menstrual cycle hormonal changes. We describe our experience with three examples where CVS were interpreted as either AGUS or HSIL, which led to a hysterectomy in 2 of 3 patients. Cervical endometriosis needs to be considered with other well-known benign conditions that mimic glandular abnormalities, including cervicitis, tubal metaplasia, lower uterine segment sampling, and microglandular hyperplasia. Published series and our own experience lead us to suggest that these smears will continue to present diagnostic difficulties.

Apoptosis in endometrial glandular and stromal cells in women with and without endometriosis

BACKGROUND

The aetiology of endometriosis is unknown. Ectopic dissemination of the endometrial cells gives origin to endometriotic lesions, but occurs in women with and without endometriosis. It has been suggested that increased ectopic cell survival facilitates their implantation. The objectives of this study were to evaluate endometrial apoptosis in women with endometriosis according to: (i) cyclic changes, (ii) glandular and stromal contribution, and (iii) stage of the disease.

METHODS

The subjects were women undergoing diagnostic laparoscopy and endometrial biopsies for suspected endometriosis. Spontaneous apoptosis was evaluated using TdT-mediated dUTP-biotin nick end-labelling (TUNEL) assay. Apoptotic cells per 10 mm(2) (apoptotic index) in an area of 10-50 mm(2) in 5 microm endometrial tissue sections were counted and location of these cells was recorded.

RESULTS

The apoptotic index in glandular epithelium was lower in endometriosis than controls (26.0 +/- 5.5 versus 51.2 +/- 9.7, P = 0.03) but not in the stroma (36.3 +/- 6.4 versus 48.4 +/- 11.3, NS). In controls, apoptosis was highest during the late secretory/menstrual and early proliferative phases and cyclic variability was apparent. In endometriosis, this cyclic variability was lost. There was a trend toward decreased apoptosis with increasing stage of the disease, but the differences lacked statistical significance.

CONCLUSIONS

Spontaneous apoptosis is decreased in the endometrial glands in women with endometriosis, especially during late secretory/menstrual and early proliferative phases of the cycle. This may indicate increased viability of endometrial cells shed during menses, facilitating their ectopic survival and implantation.

Apoptosis and the expression of Bcl-2 and Bax in patients with endometrioid, clear cell, and serous carcinomas of the uterine endometrium

OBJECTIVES

Clear cell and serous carcinoma of the uterus are rare types of endometrial carcinomas. This study was designed to investigate the differential occurrence of apoptosis, Bcl-2, and Bax in endometrioid, clear cell, and serous carcinomas.

METHODS

In a total of 28 endometrial carcinomas as well as 4 samples of normal postmenopausal endometria, apoptotic changes were examined using molecular biochemical techniques. The expression of Bcl-2 and Bax proteins was also investigated by immunohistochemical staining with appropriate antibodies.

RESULTS

Labeling of DNA in situ indicated that apoptotic cells were sporadically seen in postmenopausal endometrium (5.2 +/- 2.1, n = 4). In contrast, cells undergoing apoptosis apparently were detected in endometrioid carcinoma (29.3 +/- 3.7, n = 20), and their numbers increased intensely in clear cell (49.5 +/- 5.6, n = 5) and serous carcinomas (50.8 +/- 6.0, n = 3). Autoradiographic analysis revealed that high-molecular-weight DNA was predominant in postmenopausal endometrium. However, a DNA ladder was identified in 7 of 10 carcinomas. Although Bcl-2 was immunonegative or faintly immunopositive in all cases, many cases of endometrioid carcinoma (43.6 +/- 4.1%, n = 20) were immunopositive for Bax, unlike postmenopausal endometrium (17.6 +/- 6.7%, n = 4). Moreover, the number of cells expressing Bax increased in clear cell (60.4 +/- 6.5%, n = 5) and serous carcinomas (66.8 +/- 7.6%, n = 3) compared with that in endometrioid carcinoma.

CONCLUSIONS

These results indicate that apoptosis occurs in a specific population of cells in different histologic components of endometrial carcinomas. The expression of Bax, but not of Bcl-2, might suggest histologic differentiation in endometrial carcinomas.

Apoptosis, bcl-2 expression, and proliferation in benign and malignant endometrial epithelium: An approach using multiparameter flow cytometry

OBJECTIVE

Disturbances in the regulation of cell proliferation and differentiation play an important role in the formation of neoplastic lesions. Consequently, abnormalities in apoptosis regulation may contribute to this process. Expression of a neoepitope on cytokeratin 18, unmasked by an early caspase cleavage event and recognized by the novel monoclonal antibody M30, is an indicator of early epithelial cell apoptosis. The purpose of this study was to evaluate the quantitative relation among apoptosis (M30), cell persistence (bcl-2), and proliferation (S-phase fraction; SPF) in malignant and benign endometrium.

METHODS

Using multiparameter DNA flow cytometry on 54 formalin-fixed paraffin-embedded samples from benign (proliferative, secretory, inactive, and hyperplastic endometrium) and malignant (grades 1-3 endometrial adenocarcinoma) endometrial tissue, bcl-2 expression and M30 reactivity were assessed together with the SPF in the cytokeratin-positive epithelial cells.

RESULTS

Benign cyclic endometrium showed a relatively high bcl-2 expression and low M30 reactivity in the proliferative phase whereas in the secretory phase this relation was inverse. In endometrial hyperplasia the expression of bcl-2 was increased compared to that in secretory and postmenopausal endometrium, but still below the level of proliferative samples. The expression of M30 also increased compared to normal proliferative endometrium but did not reach the level of endometrium in the secretory phase of the menstrual cycle. In cancer the expression of bcl-2 decreased with the progression of differentiation grade. For M30 expression this relation was inverse. Overall there was a significant increase of M30 reactivity in cancerous compared to hyperplasia and normal cyclic endometrium.

CONCLUSION

Transition of endometrial epithelium from hyperplasia to cancer seems to involve both increased apoptosis and decreased bcl-2 expression. Flow cytometric evaluation of M30 and bcl-2 expression levels, with the SPF, in currettage specimens from postmenopausal patients complaining of bleeding provides a quantitative assessment of endometrial apoptosis, anti-apoptosis, and proliferation. Further studies are needed to determine the relationship among these three processes as indicators of the biological behavior of gynecological tumors.

Effect of Chlamydia trachomatis infection and subsequent tumor necrosis factor alpha secretion on apoptosis in the murine genital tract

The pathology observed during Chlamydia infection is due initially to localized tissue damage caused by the infection itself, followed by deleterious host inflammatory responses that lead to permanent scarring. We have recently reported that the infection by Chlamydia in vitro results in apoptosis of epithelial cells and macrophages and that infected monocytes secrete the proinflammatory cytokine interleukin-1beta. At the same time, proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) can also trigger apoptosis of susceptible cells. To study the possible relationship between Chlamydia trachomatis infection and apoptosis in vivo, we used the terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling technique to determine whether infection may cause apoptosis in the genital tract of mice and, conversely, whether cytokines produced during the inflammatory response may modulate the level of apoptosis. Our results demonstrate that infected cells in the endocervix at day 2 or 7 after infection are sometimes apoptotic, although there was not a statistically significant change in the number of apoptotic cells in the endocervix. However, large clumps of apoptotic infected cells were observed in the lumen, suggesting that apoptotic cells may be shed from the endocervix. Moreover, there was a large increase in the number of apoptotic cells in the uterine horns and oviducts after 2 or 7 days of infection, which was accompanied by obvious signs of upper tract pathology. Interestingly, depletion of TNF-alpha led to a decrease in the level of apoptosis in the uterine horns and oviducts of animals infected for 7 days, suggesting that the inflammatory cytokines may exert part of their pathological effect via apoptosis in infected tissues.

Primary ovarian cancer cultures are resistant to Fas-mediated apoptosis

OBJECTIVES

Fas, a primary mediator of cellular apoptosis, is expressed by the normal ovarian epithelium. We analyzed the levels of Fas and soluble Fas (sFas) expression in ovarian cancer tissue and determined the susceptibility of primary ovarian cancer cell (CSOC) cultures to Fas-mediated apoptosis.

METHODS

Fas mRNA levels were detected by RT-PCR, and Fas protein levels were determined by immunohistochemistry and Western blot analysis. Secreted sFas levels were measured by ELISA. Localization of Fas to the cell surface was demonstrated by flow cytometry. The effect of Fas on cell proliferation was measured by MTT assay.

RESULTS

Intense Fas staining was detected on the cell surface and in the cytoplasm of ovarian carcinoma specimens. We also found that mean levels of sFas, which can function as a Fas agonist, were significantly increased in 18 sera from cancer patients (0.98 ng/ml) compared to those of 8 healthy individuals (0.61 ng/ml, P = 0.004). Fas mRNA and protein were expressed in all primary ovarian cancer cell cultures. Despite abundant Fas expression, CSOC cultures were significantly less sensitive to Fas-mediated apoptosis (11.3%) than primary cultures of normal ovarian epithelial cells (HOSE) (50.0%) (P = 0.00001). The sFas level in CSOC-conditioned medium was minimal (0.07 ng/ml) and not significantly different from that of HOSE-conditioned medium (0. 09 ng/ml). The small amount of sFas secreted by CSOC does not likely account for the observed resistance to Fas-mediated apoptosis.

CONCLUSION

Decreased sensitivity to Fas-mediated apoptosis could contribute to ovarian tumorigenesis through resistance to cytotoxic T lymphocyte-mediated cytotoxicity and may play a role in ovarian tumorigenesis.

Increased bcl-2 expression is associated with primary resistance to chemotherapy in human epithelial ovarian cancer

OBJECTIVE

bcl-2, an anti-apoptotic factor, has a role in the pathogenesis of ovarian cancer as well as in resistance to chemotherapy.

DESIGN AND METHODS

20 benign, and 26 malignant epithelial ovarian tissues were analyzed for bcl-2 protein and mutant p53 by enzyme-immunoassay (EIA). Flowcytometric analysis was also performed. Patients of malignant group were followed up to monitor overall survival and primary resistance to chemotherapy.

RESULTS

bcl-2 was significantly higher in malignant group than benign group (p < 0.001). A cutoff value was determined for bcl-2 (63.8 kU/g protein). At this cutoff, sensitivity is 80.7%, and specificity is 85%. Using chi square analysis, a significant correlation was found between bcl-2 and FIGO stage (p = 0.01), overall survival (p = 0.01), as well as primary resistance to chemotherapy (p = 0.03). By correlation coefficient analysis the relation between bcl-2 and synthetic phase fraction was highly significant (p = 0.002). Bcl-2, p53, and FIGO stage were significantly correlated to poor survival (p = 0.01) in univariate analysis. However, in multivariate analysis, only FIGO stage, and p53 were independent risk factors.

CONCLUSION

EIA could be a useful tool for investigating the prognostic value of bcl-2, and its possible prediction of platinum resistance in epithelial ovarian cancer. This might help in selecting patients for future anti-bcl-2 therapy.

Evidence for alternative pathways of granulosa cell death in healthy and slightly atretic bovine antral follicles

Granulosa cell death is an early feature of atresia; however, there are many apparent contradictions in the literature concerning the mode of granulosa cell death. We have therefore examined this process in bovine healthy and atretic antral follicles, using a variety of established techniques. Light and electron microscopic observations indicated the presence of pyknotic or shrunken nuclei in both the membrana granulosa and the antrum. In the membrana granulosa, these nuclei were frequently crescent shaped and uniformly electron dense and were approximately the same size as healthy nuclei, all of which are typical of early apoptosis. However, these nuclei were within the membranes of a healthy granulosa cell, suggesting that phagocytosis by a neighboring granulosa cell is an unusually early event in the apoptotic pathway of granulosa cells. In the membrana granulosa, pyknotic nuclei stained intensely with hematoxylin but weakly with the DNA-intercalating stain propidium iodide. A percentage of these pyknotic nuclei stained by TUNEL (terminal deoxy-UTP nick end-labeling). However, in the antrum, the pyknotic nuclei and larger globules of DNA stained intensely with both hematoxylin and propidium iodide, but were not TUNEL positive. The comet assay of cell death produced a streak tail of randomly nicked DNA, rather than the plume of low mol wt apoptotic DNA. Globules collected from fresh follicular fluid stained intensely with propidium iodide and were shown by PAGE to contain DNA, the majority of which was high mol wt. In conclusion, granulosa cells within the membrana granulosa die by apoptosis, with phagocytosis by a neighboring cell preceding any potential budding of the nucleus or cell itself. Granulosa cells near the antrum are sloughed off into the antrum, and their death has features more consistent with that of other cell types that undergo death as a result of terminal differentiation.

Apoptosis, proliferation, and sex hormone receptors in superficial parts of human endometrium at the end of the secretory phase

Apoptosis with one regulator, Bcl-2, and proliferation with the marker Ki-67 were studied in 75 endometrial biopsies representing superficial parts of endometrium from 35 regularly menstruating women premenstrually and menstrually. Hormonal withdrawal was studied in serum samples and potentiated in epithelium by the decreasing 17beta-estradiol and progesterone receptor scores 4 days premenstrually. The apoptotic index increased 2 days before the onset of menstruation and peaked on the second menstrual day. The high apoptotic index together with low proliferation in endometrial epithelium at the end of the menstrual cycle are similar to the involution process seen in other hormone-dependent organs. In stroma, the apoptotic index increased later, at the onset of menstruation, and the increase was lower than that in epithelium. The Ki-67 index increased during the last 3 days of the secretory phase, parallel with an increasing progesterone receptor score and decreasing Bcl-2 staining, and peaked at the onset of menstruation. The findings in stroma concur with high proliferation at the end of the menstrual cycle and high cell turnover during menstruation, suggesting the participation of stroma in the renewal process of endometrium.

Therapeutic potential of recombinant p53 overexpression in breast cancer cells expressing endogenous wild-type p53

Reconstitution of the p53-dependent apoptotic pathway by gene transfer of a recombinant wild-type p53 minigene leads to rapid apoptotic cell death in breast and other cancer cell types expressing null or mutant p53. Tumour cells expressing wild-type p53 have been reported to be more resistant to this treatment strategy, presumably as a result of mutations in downstream regulators of p53-dependent apoptotic signalling. The MCF-7 breast cancer cell line is representative of this class of tumour cell. Our recent observation of a p53-dependent apoptotic response following adenovirus-mediated HSV thymidine kinase gene transfer and gancyclovir treatment led us to reexamine recombinant p53 cytotoxicity in MCF-7 cells. Infection with a recombinant adenovirus expressing wild-type p53 resulted in a dramatic increase in p53 protein levels and was accompanied by an increase in p21WAF/CIP1 protein levels and G1 arrest within 24 hours post-infection. A significant decrease in MCF-7 cell viability was first observed at 5 days post-infection and coincided with the appearance of morphological and biochemical changes consistent with apoptotic cell death. By day 7 post-treatment, cell viability decreased to 45% and clonogenic survival was reduced to 12% of controls. The results demonstrate that persistent, high level expression of recombinant p53 can induce programmed cell death in MCF-7 cells. While the mechanism by which p53 overexpression overcomes the defect in downstream apoptotic signalling is not clear, our data suggests that this treatment strategy may be beneficial for the class of tumour cells represented by the MCF-7 cell line.