Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

PTEN, a gene encoding a dual specificity phosphatase, is frequently altered in endometrial carcinoma. Moreover, these alterations are observed even in atypical hyperplasia of the endometrium. This evidence suggests that mutation of PTEN is an early genetic alteration involved in endometrial carcinogenesis. Adenovirus-mediated gene transfer was carried out using Ishikawa 3 H 12 and RL95-2, the endometrial cancer cell lines with completely inactivated PTEN, together with endometrial cancer cell lines HEC1-A and KLE expressing wild-type PTEN as the control. The PTEN transgene significantly suppressed cell growth in vitro through induction of apoptosis in cells lacking wild-type PTEN. Furthermore, the ex vivo tumor formation by Ishikawa 3 H 12 cells was completely inhibited by the introduction of wild-type PTEN. However, neither regression nor progression was observed in inoculated tumors of either cell line by in vivo introduction of the PTEN gene. These results suggest that PTEN may be a good candidate for gene therapy in patients with endometrial carcinoma.
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PMID:Adenovirus-mediated delivery of the PTEN gene inhibits cell growth by induction of apoptosis in endometrial cancer. 1056 10

The expression of connexin 43 was studied using immunohistochemical and Western blot analyses on cell lines of endometrial epithelial origin. Connexin proteins were examined because decreases in their expression and function have been correlated with carcinogenesis. The cell lines were chosen to represent increasing grades of endometrial cancer progression starting from FEEC (fetal endometrial epithelial cells; transformed with SV40 large T antigen) to HEC-1A (stage 1A endometrial carcinoma) to RL-95-2 (grade 2 endometrial carcinoma). Parallel studies using connexin 43 polyclonal antibodies for both Western blots and immunofluorescence showed that the levels of connexin 43 expression were normal endometrial stromal cells = FEEC > HEC-1A > RL-95-2. Consequently, we applied the immunofluorescence assay to analyze paraffin-embedded uterine sections from hysterectomy specimens of patients with normal endometrium and from patients diagnosed with grade 1, 2, and 3 endometrial cancer. Using five different cases from each category, we found an inverse correlation between connexin 43 expression and tumor grade. Our data indicate that connexin 43 expression may be useful as an adjunctive marker of progression for endometrial carcinoma.
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PMID:Changes in connexin 43 protein expression in human endometrial carcinoma. 1060 Mar 98

Endometrial cancers are generally divided into at least two different pathogenetic types. One occurs from the proliferative endometrium, depending on continuous estrogen stimulation, while the other is not related to the stimulation and occurs from the atrophic endometrium of older post-menopausal women. In order to assess the risk factors for endometrial carcinoma (EC), a case-control study with 136 Japanese women having EC and with 376 healthy controls for ECs in Japan, together with an immunohistochemical analyses on p53, estrogen (ER) and progesterone receptors (PR) of EC patients was undertaken. Nulliparity, increased BMI, hypertension, diabetes mellitus, later age at menopause and personal cancer history were all seen predominantly in the EC group. Frequency of irregular menses, polycystic ovary syndrome (PCOS) and obesity in the EC patients under 40-year old was significantly higher than the control group. Immunohistochemical expressions of ER (P<0.05) and PR (P<0. 01) were more frequently recognized in the EC of the pre-menopausal than in the post-menopausal patients. On the other hand, p53 overexpression was detected in 27.2% of the post-menopausal EC group, while only found in 7.1% of the pre-menopausal EC group. These findings indicate that possible factors related to endometrial carcinogenesis are different between the pre- and post-menopausal EC patients. Namely, untreated ovarian dysfunction such as PCOS with unopposed estrogenic action in the endometrium may be associated with development and growth of EC in younger women, yet abnormality of p53 gene may be more concerned with the development of the post-menopausal EC, independently of sex steroid influence.
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PMID:A case-control study of uterine endometrial cancer of pre- and post-menopausal women. 1060 98

Hereditary non-polyposis colorectal cancer (HNPCC) is a relatively common autosomal dominantly inherited predisposition leading to a familial occurrence of cancer of the colon, rectum, endometrium and some other organs. Cancer mortality can be significantly reduced by appropriate intervention. The diagnosis of HNPCC is suspected on the basis of early onset and multiple foci of colorectal cancer (CRC), in many cases affecting the proximal part of the colon, and of endometrial cancer. It may be confirmed by molecular genetic analysis of the mismatch repair genes, especially hMLH1 and hMSH2. In spite of considerable progress in the understanding of hereditary colon cancer, many questions which are of basic importance for the identification and appropriate genetic counselling of gene carriers remain to be answered. HNPCC defined on clinical and genealogical grounds is by no means identical with the presence of mutated mismatch-repair genes. This impedes the identification of persons/families at increased cancer risk. Mutations of other, mainly as yet unidentified genes may lead to a similar phenotype. Not only heterogeneity of the predispositions underlying CRC, but also penetrance and expressivity of the identifiable mutations of the MMR-genes, have been explored only superficially. The process of carcinogenesis in the colon can follow different routes depending on the genetic background of the patients. Its investigation will open up new possibilities of cancer prevention. In addition, genetic counselling must be developed into a more "evidence"-based medical undertaking. These gaps in the understanding of hereditary CRC and in the care of persons at risk can only be overcome through structured collaboration between family doctors, medical specialists such as gastroenterologists, oncologists and surgeons, medical geneticists and basic researchers.
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PMID:[Identification and genetic counseling of people with HNPCC (hereditary nonpolyposis colorectal cancer): old and new research goals]. 1063 51

Although tamoxifen is approved for the treatment of hormone-dependent breast cancer as well as for the prevention of breast cancer in high-risk women, several studies in animal models have shown that tamoxifen is heptocarcinogenic, and in humans, tamoxifen has been associated with an increased risk of endometrial cancer. One potential mechanism of tamoxifen carcinogenesis could involve metabolism of tamoxifen to 3,4-dihydroxytamoxifen followed by oxidation to a highly reactive o-quinone which has the potential to alkylate and/or oxidize cellular macromolecules in vivo. In the study presented here, we synthesized the 3,4-dihydroxytamoxifen, prepared its o-quinone chemically and enzymatically, and studied the reactivity of the o-quinone with GSH and deoxynucleosides. The E (trans) and Z (cis) isomers of 3,4-dihydroxytamoxifen were synthesized using a concise synthetic pathway (four steps). This approach is based on the McMurry reaction between the key 4-(2-chloroethoxy)-3,4-methylenedioxybenzophenone and propiophenone, followed by selective removal of the methylenedioxy ring of (E, Z)-1-[4-[2-(N,N-dimethylamino)ethoxy]phenyl]-1-(3, 4-methylenedioxyphenyl)-2-phenyl-1-butene with BCl(3). Oxidation of 3,4-dihydroxytamoxifen by activated silver oxide or tyrosinase gave 3,4-dihydroxytamoxifen-o-quinone as a mixture of E and Z isomers. The resulting o-quinone has a half-life of approximately 80 min under physiological conditions. Reaction of the o-quinone with GSH gave two di-GSH conjugates and three mono GSH conjugates. Incubation of 3,4-dihydroxytamoxifen with GSH in the presence of microsomal P450 gave the same GSH conjugates which were also detected in incubations with human breast cancer cells (MCF-7). Reaction of 3, 4-dihydroxytamoxifen-o-quinone with deoxynucleosides gave only thymidine and deoxyguanosine adducts; neither deoxyadenosine nor deoxycytosine adducts were detected. Preliminary studies conducted with human breast cancer cell lines showed that 3, 4-dihydroxytamoxifen exhibited cytotoxic potency similar to that of 4-hydroxytamoxifen and tamoxifen in an estrogen receptor negative (ER(-)) cell line (MDA-MB-231); however, in the ER(+) cell line (MCF-7), the catechol metabolite was about half as toxic as the other two compounds. Finally, in the presence of microsomes and GSH, 4-hydroxytamoxifen gave predominantly quinone methide GSH conjugates as reported in the previous paper in this issue [Fan, P. W., et al. (2000) Chem. Res. Toxicol. 13, XX-XX]. However, in the presence of tyrosinase and GSH, 4-hydroxytamoxifen was primarily converted to o-quinone GSH conjugates. These results suggest that the catechol metabolite of tamoxifen has the potential to cause cytotoxicity in vivo through formation of 3,4-dihydroxytamoxifen-o-quinone.
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PMID:Synthesis and reactivity of a potential carcinogenic metabolite of tamoxifen: 3,4-dihydroxytamoxifen-o-quinone. 1064 67

Hormone-related cancers, namely breast, endometrium, ovary, prostate, testis, thyroid and osteosarcoma, share a unique mechanism of carcinogenesis. Endogenous and exogenous hormones drive cell proliferation, and thus the opportunity for the accumulation of random genetic errors. The emergence of a malignant phenotype depends on a series of somatic mutations that occur during cell division, but the specific genes involved in progression of hormone-related cancers are currently unknown. In this review, the epidemiology of endometrial cancer and breast cancer are used to illustrate the paradigms of hormonal carcinogenesis. Then, new strategies for early detection and prevention of hormonal carcinogenesis are discussed. This includes developing polygenic models of cancer predisposition and the further development of safe and effective chemopreventives that block target sequence activity. We developed polygenic models for breast and prostate cancer after hypothesizing that functionally relevant sequence variants in genes involved in steroid hormone metabolism and transport would act together, and also interact with well-known hormonally related risk factors, to define a high-risk profile for cancer. A combination of genes each with minor variation in expressed activity could provide a degree of separation of risk that would be clinically useful as they could yield a large cumulative difference after several decades. The genes included in the breast cancer model are the 17beta-hydroxysteroid dehydrogenase 1 (HSD17B1) gene, the cytochrome P459c17alpha (CYP17) gene, the aromatase (CYP19) gene, and the estrogen receptor alpha (ER) gene. The prostate cancer model includes the androgen receptor gene (AR), steroid 5alpha-reductase type II (SRD5A2), CYP17 and the 3beta hydroxysteroid dehydrogenase (HSD3B2) gene. We present data from our multi-ethnic cohort to support these models.
Carcinogenesis 2000 Mar
PMID:Hormonal carcinogenesis. 1123 97

Uterine endometrial carcinoma is common among women. Several reports indicated that this cancer is influenced by androgens mediated through their receptors. The human androgen receptor gene contains a polymorphic CAG repeat in the coding region of exon 1. Other studies suggested a possible association between the CAG repeat of this gene and the development of several cancers. DNA samples isolated from 29 patients with sporadic endometrial cancer were analyzed for allelic changes in 12 highly polymorphic microsatellite loci on nine chromosomes, containing CAG repeat in the exon 1 of the androgen receptor gene. A significantly high rate of allelic change in the CAG repeat was observed (51.7%) in these patients, although the frequencies of additional loci were similar to those reported by others (0-22.2%). The changed alleles of the tumor tissue were always longer than that of normal tissue except in only one case. Since only one allele on the X chromosome is commonly active in female cells, a differential methylation assay was carried out by using genomic DNA cut with HpaII. In 14 of 15 cases, we found that the activated allele was longer in these samples from tumor tissues than those from normal tissue; in the remaining case, the length of this repeat was unchanged. The expression assays were done by using poly(A+) RNA from tumor and normal uterine tissues, revealing that an activated allele in these tumor tissues was longer than that in the normal tissues in all the cases examined. These findings suggest that expansions of the CAG repeat in the androgen receptor gene may play an important role in the carcinogenesis of uterine endometrial cells.
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PMID:The expansion of the CAG repeat in exon 1 of the human androgen receptor gene is associated with uterine endometrial carcinoma. 1070 86

PTEN mutations have been reported to be frequent in endometrioid carinomas of the endometrium (EEC). Some correlation has been found between PTEN mutations and the presence of microsatellite instability (MI) in EEC, but no convincing cause-effect relationship for such association has been offered. DNA of 38 patients with endometrial carcinoma (EC) was extracted from blood and from fresh-frozen and paraffin-embedded tumor tissue. PTEN mutations were detected by single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Results were correlated with MI status and clinicopathologic data. PTEN mutations were detected in 17 tumors (44.7%), and they were more frequent in endometrioid (EEC) (17 of 33, 51.5%) than in nonendometrioid carcinomas (NEEC) (0 of 5, 0%). PTEN mutational spectrum differed between MI+ and MItumors. PTEN mutations were detected in 9 of 15 MI+ tumors (60%), but in only 8 of 23 MI- neoplasms (34.8%). In EC with MI, PTEN mutations were detected in short coding mononucleotide repeats (A)s and (A)6 in 4 of 9 carcinomas (44.4%). These results confirm that PTEN is an important target gene in endometrial carcinogenesis. The occurrence of PTEN mutations in short coding mononucleotide repeats in MI-positive tumors suggests that these mutations may be secondary to deficiencies in mismatch repair and gives some explanation for the frequent presence of PTEN mutations in these tumors.
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PMID:PTEN mutations in endometrial carcinomas: a molecular and clinicopathologic analysis of 38 cases. 1074 73

Since the estrogen receptor alpha (ER) is an important mediator of hormonal responses such as proliferation in estrogen-sensitive tissues, we hypothesized that polymorphisms in the ER gene could be functional and associated with endometrial cancer risk. We performed a population-based case-control study in Sweden, focusing on restriction fragment length polymorphisms for XbaI and PvuII and an upstream TA repeat polymorphism. In the main analysis, 154 cases and 205 controls who never used hormone replacement therapy took part and we calculated age-adjusted and multivariate odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression. The XbaI X allele appeared to confer a reduced risk for endometrial cancer. The multivariate OR for the XX genotype was 0.52 (95% CI 0.21-1.29) compared to the xx genotype and there were suggestions of decreasing risk with increasing number of X alleles (P for trend = 0.07). The PvuII PP genotype was also associated with a non-significantly decreased risk for endometrial cancer (multivariate OR 0.70, 95% CI 0.34-1.44) compared with the pp genotype (P for trend = 0.43). The multivariate OR for two short TA (<19 repeats) alleles versus two long alleles was 1.54 (95% CI 0. 73-3.27) and there were suggestions of increasing risk with increasing number of short alleles (P for trend = 0.26). We observed the same pattern of results in an expanded group of subjects, which included women who had used hormone replacement (in total 288 cases and 392 controls). Our data suggest that variants of the ER gene may be associated with an altered risk of endometrial cancer.
Carcinogenesis 2000 Apr
PMID:Estrogen receptor alpha gene polymorphisms and endometrial cancer risk. 1075 95

Tamoxifen was administered orally to neonatal rats on days 2-5 after birth and the subsequent effects on the uterus were characterized, morphometrically, over the following 12 months. Tamoxifen inhibited development of the uterus and glands in the endometrium, indicating a classical oestrogen antagonist action. Between 24 and 35 months after tamoxifen treatment there was a significant increase in the incidence (26%) of uterine adenocarcinomas and a 9% incidence of squamous cell carcinomas of the vagina/cervix in the absence of any oestrogen agonist effect in the uterus. This demonstrates that an oestrogen agonist effect is not an absolute requirement for the carcinogenic effect of tamoxifen in the reproductive tract of the rat. The unopposed oestrogen agonist effect of tamoxifen on the endometrium may not be the only factor involved in the development of endometrial cancers. It is possible that tamoxifen causes these tumours via a genotoxic mechanism similar to that seen in rat liver. However, using (32)P-post-labelling we failed to find evidence of tamoxifen-induced DNA adducts in the uterus. Tamoxifen may affect hormonal imprinting of oestrogen receptor responses in stem cells of the uterus, causing reproductive tract cancers to arise at a later time, in the same way as has been proposed for diethylstilbestrol. If these rodent data extrapolate to humans, then women who are taking tamoxifen as a chemopreventative may have an increased risk of vaginal/cervical cancer, as well as endometrial cancer.
Carcinogenesis 2000 Apr
PMID:Tamoxifen induces endometrial and vaginal cancer in rats in the absence of endometrial hyperplasia. 1075 17


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