Indole-3-carbinol inhibits telomerase activity and gene expression in prostate cancer cell lines.

BACKGROUND: Indole-3-carbinol (I3C) is a phytochemical with anticarcinogenic properties. Telomerase activity is key in carcinogenesis. We investigated the effect of I3C on telomerase in human prostate cancer cell lines LNCaP and PC3. MATERIALS AND METHODS: Cells were treated with I3C at 100 and 250 µM with and without 10-50 µM diethylstilbestrol (DES). Telomerase activity was performed using TRAPaze Telomerase Detection Kit, and hTERT gene expression by real time quantitative RT-PCR. RESULTS: I3C (250 µM) inhibited telomerase activity and mRNA expression of hTERT in LNCaP and PC3 cells. I3C at 250 µM combined with any concentration of DES was cytotoxic to LNCaP. Telomerase activity in PC3 cells with 250 µM of I3C and 25 or 50 µM of DES was significantly reduced or inhibited, respectively. I3C combined with DES reduced PC3 viability and eliminated LNCaP cells. CONCLUSION: I3C significantly inhibited telomerase activity and hTERT mRNA expression in LNCaP and PC3 cells. Combination of I3C and DES enhanced the inhibitory effect on telomerase activity, gene expression, and cell viability. These results implied that I3C and DES combined might help in prostate cancer treatment.

[The use of video capsule endoscopy in diseases of the small bowel, esophagus and colon].

Capsule endoscopy has been in clinical practice for approximately a decade. The original capsule was designed for the small bowel, followed by esophageal, patency and colonic capsules. The aim of the present guidelines are to update the readers with the mode and preparations for use of the various capsules, the indications, as well as absolute and relative contraindications for their use. This document was written by the advanced technology group within the Israel Gastroenterology Association and was edited by the members of the Israel Gastroenterology Association.

The synthetic estrogen diethylstilbestrol (DES) inhibits the telomerase activity and gene expression of prostate cancer cells.

BACKGROUND: Telomerase, which lengthens telomeres, is normally down-regulated in somatic cells and highly up-regulated in dividing cells, such as malignant cells. Human prostate cancer is androgen dependent. Estrogens, including the synthetic estrogen diethylstilbestrol (DES), are used in prostate cancer treatment to reduce androgen levels via feedback inhibition of the hypothalamic release of luteinizing hormone releasing hormone (LH-RH). DES has also direct anticancer activities, such as apoptosis induction. We investigated in vitro the effect of DES on telomerase activity and on gene expression in the presence and absence of androgens. We used two prostate cancer cell lines: LNCaP (androgen dependent) and PC3 (androgen independent). METHODS: LNCaP and PC3 cells were treated with 0.1-1,000 nM testosterone or dihydrotestosterone (DHT) in the presence of DES (25 or 50 microM). Cell telomerase activity and gene expression (mRNA) were measured. RESULTS: LNCaP: As expected, testosterone and DHT significantly increased telomerase activity and gene expression. However, these effects were inhibited by DES. Contrary to expectations, the combination of DES and testosterone functioned synergistically leading to complete inhibition of telomerase activity. PC3: Testosterone and DHT did not affect telomerase activity and gene expression, whereas DES, in the absence or presence of the androgens, significantly inhibited telomerase activity. CONCLUSIONS: In the present study, we demonstrated the ability of DES to inhibit telomerase in prostate cancer cells. Androgens did not limit the inhibitory effect and even acted synergistically with DES in the LNCaP line. This phenomenon should be considered if telomerase inhibition is part of prostate cancer treatment.

Pigs in sequence space: a 0.66X coverage pig genome survey based on shotgun sequencing.

BACKGROUND: Comparative whole genome analysis of Mammalia can benefit from the addition of more species. The pig is an obvious choice due to its economic and medical importance as well as its evolutionary position in the artiodactyls. RESULTS: We have generated approximately 3.84 million shotgun sequences (0.66X coverage) from the pig genome. The data are hereby released (NCBI Trace repository with center name "SDJVP", and project name "Sino-Danish Pig Genome Project") together with an initial evolutionary analysis. The non-repetitive fraction of the sequences was aligned to the UCSC human-mouse alignment and the resulting three-species alignments were annotated using the human genome annotation. Ultra-conserved elements and miRNAs were identified. The results show that for each of these types of orthologous data, pig is much closer to human than mouse is. Purifying selection has been more efficient in pig compared to human, but not as efficient as in mouse, and pig seems to have an isochore structure most similar to the structure in human. CONCLUSION: The addition of the pig to the set of species sequenced at low coverage adds to the understanding of selective pressures that have acted on the human genome by bisecting the evolutionary branch between human and mouse with the mouse branch being approximately 3 times as long as the human branch. Additionally, the joint alignment of the shot-gun sequences to the human-mouse alignment offers the investigator a rapid way to defining specific regions for analysis and resequencing.

Cytokeratin 20 as a biomarker of gestational trophoblastic disease: diagnostic and prognostic significance.

OBJECTIVES: This study was designed to examine whether cytokeratin 20 (CK20) is expressed in molar pregnancies and may therefore be used in the diagnosis of gestational trophoblastic disease (GTD). The potential of CK20 expression in predicting the evolution and the prognosis of the different subtypes of GTD was also assessed. METHODS: A total of 48 samples were studied for CK20 expression by RT-PCR methodology. Among these, 24 samples were obtained by curettage of the uterine cavity of patients diagnosed with hydatidiform mole (14 complete moles and 10 partial moles), 4 samples were obtained from choriocarcinoma cell lines (2 JAR and 2 JEG), and 20 samples were of normal trophoblast (control group) obtained from patients that underwent elective termination of pregnancy. RESULTS: Expression of CK20 was identified in all the samples of complete mole (CM), all choriocarcinoma cell lines, and 50% of the patients with partial mole (PM). None of the preparations of normal trophoblastic tissue from the control group expressed the CK20. A significant difference (P < 0.00001) was found in CK20 expression between samples of patients with GTD and control samples. Comparison between CK20 expression in CMs and PMs revealed a significantly more frequent expression of CK20 in CMs (P = 0.006). More than 50% of the patients with PMs that were positive for CK20 had an invasive evolution. CONCLUSIONS: In our opinion, CK20 may assist in distinguishing between molar and normal trophoblastic tissue and may be considered a marker of GTD. In cases in which pathological classification of different subtypes of GTD is in doubt, CK20-positive expression is suggestive for a CM whereas CK20-negative is more indicative for PM.

Detection of tumor circulating cells by cytokeratin-20 in the blood of patients with granulosa cell tumors.

OBJECTIVE: Cytokeratins (CKs) are constituents of the intermediate filaments of epithelial cells which are expressed in various combinations, depending on the epithelial type and the degree of differentiation. Using the reverse transcriptase-polymerase chain reaction (RT-PCR) technique, we recently demonstrated that cytokeratin-20 (CK-20), the most recently discovered cytokeratin, is expressed in endometrial carcinoma tumors, in blood, and in lymph nodes with micrometastases of patients treated for endometrial carcinomas. However, CK-20 expression could not be demonstrated in the endometrium of patients with benign diseases, in peripheral blood, in lymph nodes of healthy subjects, or in normal blood cells. The aim of this study was to examine whether CK-20 expression in blood can be used as a biomarker for the detection of the dissemination of malignant cells in patients treated for granulosa cell tumors (GCTs). METHODS: In this study, we used RT-PCR to determine the expression of CK-20 in the following groups: (i) blood of patients (n = 14) treated for GCTs, (ii) GCT samples (n = 4); (iii) lymph nodes (n = 2) of patients treated for GCTs; (iv) blood from subjects with benign sex-cord-stromal tumors (n = 2); (v) normal ovaries of two menstruating women (n = 4); (vi) tumor specimens of epithelial ovarian carcinomas (EOCs) (n = 14); and (vii) blood samples (n = 18) and lymph nodes (n = 11) of healthy women. RESULTS: In Group I, CK-20 was positive in the blood in 86% (12/14) of the patients. In Group II, CK-20 was positive in 100% (4/4) of the GCT samples. In Group III, CK-20 was positive in 100% (2/2) of the lymph nodes examined. In Groups IV and V, CK-20 was negative in 100% (2/2) of the blood samples and in the normal ovarian specimens (4/4) that were examined. In Group VI, CK-20 was positive in 14% (2/14) of nonmucinous EOCs. In Group VII, CK-20 was negative in 100% (18/18) of blood and in (11/11) lymph node specimens (specificity 100%). CONCLUSIONS: These results indicate that RT-PCR of CK-20, because of its high sensitivity and specificity, is a potential biomarker for detecting metastases in blood and in micrometastases in lymph nodes of patients treated for GCTs.