89 research outputs found

    Methylation mediated silencing of TMS1/ASC gene in prostate cancer

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    BACKGROUND: Transcriptional silencing associated with aberrant promoter methylation has been established as an alternate pathway for the development of cancer by inactivating tumor suppressor genes. TMS1 (Target of Methylation induced Silencing), also known as ASC (Apoptosis Speck like protein containing a CARD) is a tumor suppressor gene which encodes for a CARD (caspase recruitment domain) containing regulatory protein and has been shown to promote apoptosis directly and by activation of downstream caspases. This study describes the methylation induced silencing of TMS1/ASC gene in prostate cancer cell lines. We also examined the prevalence of TMS1/ASC gene methylation in prostate cancer tissue samples in an effort to correlate race and clinico-pathological features with TMS1/ASC gene methylation. RESULTS: Loss of TMS1/ASC gene expression associated with complete methylation of the promoter region was observed in LNCaP cells. Gene expression was restored by a demethylating agent, 5-aza-2'deoxycytidine, but not by a histone deacetylase inhibitor, Trichostatin A. Chromatin Immunoprecipitation (ChIP) assay showed enrichment of MBD3 (methyl binding domain protein 3) to a higher degree than commonly associated MBDs and MeCP2. We evaluated the methylation pattern in 66 prostate cancer and 34 benign prostatic hyperplasia tissue samples. TMS1/ASC gene methylation was more prevalent in prostate cancer cases than controls in White patients (OR 7.6, p 0.002) while no difference between the cases and controls was seen in Black patients (OR 1.1, p 0.91). CONCLUSION: Our study demonstrates that methylation-mediated silencing of TMS1/ASC is a frequent event in prostate cancer, thus identifying a new potential diagnostic and prognostic marker for the treatment of the disease. Racial differences in TMS1/ASC methylation patterns implicate the probable role of molecular markers in determining in susceptibility to prostate cancer in different ethnic groups

    Epigenetics in Prostate Cancer

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    Prostate cancer (PC) is the most commonly diagnosed nonskin malignancy and the second most common cause of cancer death among men in the United States. Epigenetics is the study of heritable changes in gene expression caused by mechanisms other than changes in the underlying DNA sequences. Two common epigenetic mechanisms, DNA methylation and histone modification, have demonstrated critical roles in prostate cancer growth and metastasis. DNA hypermethylation of cytosine-guanine (CpG) rich sequence islands within gene promoter regions is widespread during neoplastic transformation of prostate cells, suggesting that treatment-induced restoration of a “normal” epigenome could be clinically beneficial. Histone modification leads to altered tumor gene function by changing chromosome structure and the level of gene transcription. The reversibility of epigenetic aberrations and restoration of tumor suppression gene function have made them attractive targets for prostate cancer treatment with modulators that demethylate DNA and inhibit histone deacetylases

    The benefits of 24/7 in-house intensivist coverage for prolonged-stay cardiac surgery patients

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    ObjectiveThe objective of our study was to evaluate the efficacy of 24/7 in-house intensivist care for patients requiring prolonged intensive care unit (ICU) stay following cardiac surgery.MethodsA propensity-matched retrospective before-and-after observational study comparing 2 models of ICU physician staffing was undertaken. Previously, residents (with intensivist backup) provided care for patients after cardiac surgery (surgical ICU cohort). ICU physician staffing was modified with the implementation of 24/7 in-house board-certified intensivist coverage in a cardiac surgery ICU (cardiac surgery ICU cohort) for postoperative care. Patients with a prolonged ICU stay (ie, >48 hours) were identified and their outcomes analyzed for both models of care.ResultsPropensity matching between cohorts was successful for 271 patients (75.7%), with matched patients being used for comparison. There was no difference in ICU or 30-day mortality. There was also no difference in ICU length of stay (LOS); however, the median hospital LOS was significantly shorter in the cardiac surgery ICU cohort (12.3 vs 11.0 days; P < .01). There was a decrease in the proportion of patients receiving transfused red blood cells in the cardiac surgery ICU cohort (80.8% vs 65.7%; P < .001). The cardiac surgery ICU cohort had reduced complications relating to sepsis (4.7% vs 0.7%; P < .01) and renal failure (22.5% vs 12.5%; P < .01); however, the identification of neurologic dysfunction was significantly higher (11.1% vs 20.7%; P < .01).ConclusionsFor patients requiring a prolonged ICU stay, our model of 24/7 in-house intensivist coverage was not associated with changes in ICU LOS, nor ICU and 30-day mortality. However a reduction in blood product use, ICU complications, and total hospital LOS was observed

    Transcriptional regulation by the estrogen receptor of antioxidative stress enzymes and its functional implications

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    We previously reported that antiestrogen-liganded estrogen receptor b (ERb) transcriptionally activates the major detoxifying enzyme quinone reductase (QR) (NAD(P)H:-quinone oxidoreductase). Our studies also indicate that upregulation of QR, either by overexpression or induction by tamoxifen, can protect breast cells against oxidative DNA damage caused by estrogen metabolites. We now report on the upregulation of glutathione S-transferases Pi (GST-Pi) and gamma-glutamylcysteine synthetase heavy subunit (GCSh) expression by antiestrogens. Studies indicate the regulation of GST-Pi and GCSh transcriptional activity by ER. While ER regulation is mediated by an electrophile response element (EpRE), we identified mechanistic differences in the involvement of other transcription factors. Regardless of these differences, ERb-mediated regulation of GST-Pi and GCSh point towards an important role for ERb in cellular protection against oxidative stress. A protective role is supported by our observation of inhibition of estrogeninduced DNA damage upon upregulation of GST-Pi and GCSh expression

    Orthotopic Ileal Neobladder Reconstruction for Bladder Cancer: Is Adjuvant Chemotherapy Safe?

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    ABSTRACT Objective: We examined our database of patients undergoing radical cystectomy (RC) with orthotopic neobladder (NB) to determine whether adjuvant chemotherapy in this group is safe. Materials and Methods: We performed a retrospective analysis of patients who underwent radical cystectomy and urinary diversion between 1992 and 2004. Relevant clinical and therapeutic data were entered into a database. High-risk bladder cancer patients who underwent NB were identified. They were stratified into 2 groups, those who received adjuvant chemotherapy and those who did not. The incidence of complications between the 2 groups was analyzed and compared. Results: Over the 12-year period, 136 patients underwent RC and NB construction for bladder cancer. Of these, 83 patients were at high risk for recurrence. Nineteen patients received adjuvant chemotherapy and 64 did not. The complication rate in the adjuvant chemotherapy group was 53% and it was 23% in those who did not receive chemotherapy. There were no perioperative or treatment related death. There were 2 patients with grade 4 toxicity in the adjuvant chemotherapy group. There was a statistical difference between these two groups with regard to the incidence of complications. However, none of these complications was life-threatening, required only conservative treatment and caused no long-term disability. Conclusions: Adjuvant chemotherapy is a safe treatment for patients undergoing RC and NB substitution. Hence, the option of orthotopic NB should not be denied in selected bladder cancer patients with high risk for recurrent disease
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