Hypermethylation of the human telomerase catalytic subunit (hTERT) gene correlates with telomerase activity

DNA methylation is an epigenetic process involved in embryonic development, differentiation and aging. It is 1 of the mechanisms resulting in gene silencing in carcinogenesis, especially in tumor suppressor genes (e.g., p16, Rb). Telomerase, the DNA polymerase adding TTAGGG repeats to the chromosome end, is involved in the regulation of the replicative life span by maintaining telomere length. This enzyme is activated in germ and stem cells, repressed in normal somatic cells and reactivated in a large majority of tumor cells. The promoter region of the hTERT gene, encoding for the catalytic subunit of human telomerase, has been located in a CpG island and may therefore be regulated at least in part by DNA methylation. We analyzed the methylation status of 27 CpG sites within the hTERT promoter core region by methylation-sensitive single-strand conformation analysis (MS-SSCA) and direct sequencing using bisulfite-modified DNA in 56 human tumor cell lines, as well as tumor and normal tissues from different organs. A positive correlation was observed among hypermethylation of the hTERT promoter, hTERT mRNA expression and telomerase activity (p < 0.00001). Furthermore, this correlation was confirmed in normal tissues where hypermethylation of the hTERT promoter was found exclusively in hTERT-expressing telomerase-positive samples and was absent in telomerase-negative samples (p < 0.00002). Since tumor tissues contain also nonneoplastic stromal elements, we performed microdissection to allow confirmation that the hTERT promoter methylation truly occurred in tumor cells. Our results suggest that methylation may be involved in the regulation of hTERT gene expression. To our knowledge, this is the first gene in which methylation of its promoter sequence has been found to be positively correlated with gene expression.     

Tumor cell-targeting by phage-displayed peptides

We isolated cancer cell-specific phages by subtracting and selecting complex peptide display phage libraries on cultured human cancer cells. The best candidate was selected by performing three rounds of subtraction before each of five selections on the human colorectal WiDr cell line. The phage showed more than 1000-fold higher binding efficiency for WiDr cells when compared to five other human cancer cell lines, including two of colorectal origin, and when compared to wild-type M13 phage. Fifty-fold higher binding efficiency was also seen for a human breast cancer cell line. We show that the WiDr cell binding of the selected phage was efficiently competed by the synthetic peptide HEWSYLAPYPWF, predicted from the phage sequence. This confirms that the specificity of the peptide is independent of the display by the phage coat proteins. The identified peptide may target biomarkers linked to colorectal cancer, and thus be useful for designing gene transfer vectors as well as diagnostic and prognostic tools for this disease.     

Conservative management of malignant and borderline ovarian tumor

Conservative management of at least a part of one ovary and the uterus, in order to preserve fertility-potential, could be propose in most of patients with nonepithelial and borderline ovarian tumor. This conservative management could be performed even in patients with borderline ovarian tumor associated with noninvasive peritoneal implants (if complete resection of peritoneal disease). A removal of the preserved ovary after completion of the pregnancy(ies) is not necessary if patients agree to a careful follow-up procedure. In patient with epithelial ovarian cancer, conservative management could be performed only in case of young patients who desire to preserve fertility function with: unilateral tumor (stage IA), grade 1 (and 2?), who underwent an adequate staging surgery (including peritoneal washings, omentectomy, multiple peritoneal biopsies, uterine curettage and complete pelvic and paraaortic lymphadenectomy) and with a careful follow-up. A conservative management should not be performed in patients with tumor stage > IA and/or grade 3. Removal of preserved ovary should be performed after completion of pregnancy(ies) in order to reduce the risk of ovarian recurrence.     

Risk of pulmonary embolism after a negative spiral CT angiogram in patients with pulmonary disease: 1-year clinical follow-up study

PURPOSE: To evaluate the effect of pulmonary disease on diagnostic utility of spiral computed tomographic (CT) angiography in clinical practice. MATERIALS AND METHODS: Three hundred thirty-four patients, including 215 patients with pulmonary disease (group 1) and 119 patients with no history of respiratory disorder (group 2), were referred for thin-collimation CT angiography of the pulmonary circulation as the first-line diagnostic test. Patients with negative angiograms who had not received anticoagulation therapy and who could be clinically followed up at 3 months, 6 months, and 1 year were considered in the final study groups (n = 185); 135 patients had lung disease (group 3), and 50 patients had no history of a respiratory disorder (group 4). RESULTS: Between groups 3 and 4, no significant differences were found in the referral location, age, and risk factors. Confident evaluation of pulmonary arteries down to the subsegmental level was performed in 31 (23%) patients in group 3 and in 15 (30%) in group 4 (P =.5). Three episodes of acute pulmonary embolism (PE), all fatal, were diagnosed in group 3 patients; two cases occurred 14 days and one case occurred 6 months after the negative spiral CT scan. The negative predictive value of spiral CT angiography was 98% (175 of 178) in the study group in which follow-up was performed, with no significant difference between the values in groups 3 (98% [132 of 135]) and 4 (100% [50 of 50]). CONCLUSION: Underlying respiratory disease does not affect the negative predictive value of thin-collimation CT angiography, which appears to be a reliable tool in the work-up in this subgroup of patients with acute PE.     

Laparoscopic appendectomy: indications and controversies

The introduction of laparoscopic appendectomy has been more controversial than that of laparoscopic cholecystectomy. Randomized trials have been performed, as well as meta-analysis, with equivocal results regarding effectiveness. The further expansion of the technique for interval appendectomy and in cases of complicated appendicitis has introduced new controversies and success stories. We hope to review the current application of laparoscopic appendectomy in adults based on the available literature and discuss some current controversies.     

First-Line Treatment of Metastatic Breast Cancer

For many years, tamoxifen was the mainstay of treatment for hormone receptor-positive metastatic breast cancer (MBC). However, in recent years, newer endocrine agents, particularly aromatase inhibitors, have consistently proved their superiority over tamoxifen by improving clinical outcomes. These agents have therefore been incorporated into first-line treatment strategies for endocrine-responsive disease. The chemother-apeutic armamentarium has also been enriched with new agents and combinations that have played a role in improving breast cancer survival in recent decades. However, few chemotherapy clinical trials have claimed a clear survival benefit of one regimen over another. More recently, the development of biologic agents has further widened the spectrum of available therapies. Among these, trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2), has significantly altered the lives of patients with HER2-positive MBC. The transfer of research findings to clinical practice is a delicate process that implies the ability to adequately tailor evidence obtained from well designed clinical trials to the individual patient. This article discusses landmark studies in the treatment of MBC, with emphasis on those treatments used as ‘first-line’ therapy following relapse.     

Low frequency of α-synuclein mutations in familial Parkinson's disease

A mutation in exon 4 of the α-synuclein (NACP) gene has been reported to explain the chromosome 4 linkage to autosomal dominant Parkinson's disease. We developed primers and methods for exonic sequencing of this gene and sequenced the entire coding region of the gene in 6 families with autosomal dominant disease and in 2 cases of lytico and bodig from Guam. In addition, we have sequenced exon 4 of this gene in 5 cases of familial disease and have screened for the specific mutation (A53T) in a 40 cases of idiopathic Parkinson's disease, 3 cases of multisystem atrophy, and 15 cases of Lewy body dementia. We have found no genetic variation in the gene. We discuss these findings with respect to both the epidemiology of Parkinson's disease and the possibility that NACP is not the chromosome 4 locus for disease.     

Activated human platelets express β2 integrin

Abstract: The expression of molecules of the β2 integrin family (CD11a, CD11b, CD11c and CD18) was explored on 2 human megakaryocytic cell lines and on platelets from different donors by immunofluorescence and flow cytometry using a large panel of mAb. CD11a, CD11b, CD11c and CD18 were detected on the megakaryocytic cell lines DAMI and HEL. A low and variable expression of CD11a, CD11b and CD18 determinants was also detected on resting platelets: this expression was markedly increased when platelets were activated by thrombin. Expression of CD18 was closely correlated to that of CD11a or CD11b when comparing the fluorescence intensity observed in different experiments. In presence of Ca⁺⁺, platelets did bind to a RAJI cell line which exhibits a high expression level of CD54. This binding was increased when platelets were activated by thrombin and was decreased by an anti CD11a, CD18 and anti CD54 mAb. This study indicates that human platelets express molecules of the β2 integrin family, when activated, which allows them to bind to CD54 bearing cells.