Phosphorylation at Ser-15 may be a critical event in the up-regulation and functional activation of p53 during cellular stress. In this report we provide evidence that the ATM-Rad3-related protein ATR regulates phosphorylation of Ser-15 in DNA-damaged cells. Overexpression of catalytically inactive ATR (ATR ki ) in human fibroblasts inhibited Ser-15 phosphorylation in response to ␥-irradiation and UV light. In ␥-irradiated cells, ATR ki expression selectively interfered with late-phase Ser-15 phosphorylation, whereas ATR ki blocked UV-induced Ser-15 phosphorylation in a time-independent manner. ATR phosphorylated p53 at Ser-15 and Ser-37 in vitro, suggesting that p53 is a target for phosphorylation by ATR in DNA-damaged cells.
Objective-To prospectively assess pelvic and para-aortic lymph node metastases in endometrial cancer with lymphatic dissemination, emphasizing the examination of para-aortic metastases relative to the inferior mesenteric artery (IMA).Methods-Over 36 months, 422 consecutive patients were managed by predefined surgical guidelines differentiating low-risk patients from patients at risk for dissemination requiring systematic lymphadenectomy. Low risk was defined as grade 1 or 2 endometrioid type with myometrial invasion (MI) ≤50% and primary tumor diameter (PTD) ≤2 cm. Pelvic and para-aortic lymph nodes were submitted separately, with nodes identified from all 8 pelvic and 4 para-aortic node-bearing basins. Surgical quality assessments examined median node counts (primary surrogate for quality) and nodes harvested above and below the IMA and excised gonadal veins (secondary surrogates).Results-Lymphadenectomy was not required in 27% of patients (all low risk) and in 33% (n=112) of endometrioid cases. However, 22 patients (20%) of this latter cohort had lymphadenectomy and all lymph nodes were negative. Sixty-three (22%) of 281 patients undergoing lymphadenectomy had lymph node metastases: both pelvic and para-aortic in 51%, only pelvic in 33%, and isolated to the para-aortic area in 16%. Therefore, 67% of patients with lymphatic dissemination had para-aortic lymph node metastases. Furthermore, 77% of patients with para-aortic node involvement had metastases above the IMA, whereas nodes in the ipsilateral para-aortic area below the IMA and ipsilateral common iliac basin were declared negative in 60% and 71%, respectively. Gonadal veins were excised in 25 patients with para-aortic node metastases; 7 patients (28%) had documented metastatic involvement of gonadal veins or surrounding soft tissue.Conclusions-The high rate of lymphatic metastasis above the IMA indicates the need for systematic pelvic and para-aortic lymphadenectomy (vs sampling) up to the renal vessels. The latter should include consideration of excision of the gonadal veins. Conversely, lymphadenectomy does not benefit patients with grade 1 and 2 endometrioid lesions with MI ≤50% and PTD ≤2 cm.
6 Corresponding author ATR, a phosphatidylinositol kinase-related protein homologous to ataxia telangiectasia mutated (ATM), is important for the survival of human cells following many forms of DNA damage. Expression of a kinaseinactive allele of ATR (ATRkd) in human fibroblasts causes increased sensitivity to ionizing radiation (IR), cis-platinum and methyl methanesulfonate, but only slight UV radiation sensitivity. ATRkd overexpression abrogates the G 2 /M arrest after exposure to IR, and overexpression of wild-type ATR complements the radioresistant DNA synthesis phenotype of cells lacking ATM, suggesting a potential functional overlap between these proteins. ATRkd overexpression also causes increased sensitivity to hydroxyurea that is associated with microtubule-mediated nuclear abnormalities. These observations are consistent with uncoupling of certain mitotic events from the completion of S-phase. Thus, ATR is an important component of multiple DNA damage response pathways and may be involved in the DNA replication (S/M) checkpoint.
Molecular classification of high-grade serous ovarian cancer (HGSOC) using transcriptional profiling has proven to be complex and difficult to validate across studies. We determined gene expression profiles of 174 well-annotated HGSOCs and demonstrate prognostic significance of the prespecified TCGA Network gene signatures. Furthermore, we confirm the presence of four HGSOC transcriptional subtypes using a de novo classification. Survival differed statistically significantly between de novo subtypes (log rank, P = .006) and was the best for the immunoreactive-like subtype, but statistically significantly worse for the proliferative- or mesenchymal-like subtypes (adjusted hazard ratio = 1.89, 95% confidence interval = 1.18 to 3.02, P = .008, and adjusted hazard ratio = 2.45, 95% confidence interval = 1.43 to 4.18, P = .001, respectively). More prognostic information was provided by the de novo than the TCGA classification (Likelihood Ratio tests, P = .003 and P = .04, respectively). All statistical tests were two-sided. These findings were replicated in an external data set of 185 HGSOCs and confirm the presence of four prognostically relevant molecular subtypes that have the potential to guide therapy decisions.
BackgroundEpithelial ovarian cancer is the leading cause of gynecologic cancer deaths. Most patients respond initially to platinum-based chemotherapy after surgical debulking, however relapse is very common and ultimately platinum resistance emerges. Understanding the mechanism of tumor growth, metastasis and drug resistant relapse will profoundly impact the therapeutic management of ovarian cancer.Methods/Principal FindingsUsing patient tissue microarray (TMA), in vitro and in vivo studies we report a role of of cystathionine-beta-synthase (CBS), a sulfur metabolism enzyme in ovarian carcinoma. We report here that the expression of cystathionine-beta-synthase (CBS), a sulfur metabolism enzyme, is common in primary serous ovarian carcinoma. The in vitro effects of CBS silencing can be reversed by exogenous supplementation with the GSH and H2S producing chemical Na2S. Silencing CBS in a cisplatin resistant orthotopic model in vivo by nanoliposomal delivery of CBS siRNA inhibits tumor growth, reduces nodule formation and sensitizes ovarian cancer cells to cisplatin. The effects were further corroborated by immunohistochemistry that demonstrates a reduction of H&E, Ki-67 and CD31 positive cells in si-RNA treated as compared to scrambled-RNA treated animals. Furthermore, CBS also regulates bioenergetics of ovarian cancer cells by regulating mitochondrial ROS production, oxygen consumption and ATP generation. This study reports an important role of CBS in promoting ovarian tumor growth and maintaining drug resistant phenotype by controlling cellular redox behavior and regulating mitochondrial bioenergetics.ConclusionThe present investigation highlights CBS as a potential therapeutic target in relapsed and platinum resistant ovarian cancer.
Purpose To provide guidance to clinicians regarding the use of neoadjuvant chemotherapy and interval cytoreduction among women with stage IIIC or IV epithelial ovarian cancer. Methods The Society of Gynecologic Oncology and the American Society of Clinical Oncology convened an Expert Panel and conducted a systematic review of the literature. Results Four phase III clinical trials form the primary evidence base for the recommendations. The published studies suggest that for selected women with stage IIIC or IV epithelial ovarian cancer, neoadjuvant chemotherapy and interval cytoreduction are noninferior to primary cytoreduction and adjuvant chemotherapy with respect to overall and progression-free survival and are associated with less perioperative morbidity and mortality. Recommendations All women with suspected stage IIIC or IV invasive epithelial ovarian cancer should be evaluated by a gynecologic oncologist prior to initiation of therapy. The primary clinical evaluation should include a CT of the abdomen and pelvis, and chest imaging (CT preferred). Women with a high perioperative risk profile or a low likelihood of achieving cytoreduction to <1 cm of residual disease (ideally to no visible disease) should receive neoadjuvant chemotherapy. Women who are fit for primary cytoreductive surgery, and with potentially resectable disease, may receive either neoadjuvant chemotherapy or primary cytoreductive surgery. However, primary cytoreductive surgery is preferred if there is a high likelihood of achieving cytoreduction to < 1 cm (ideally to no visible disease) with acceptable morbidity. Before neoadjuvant chemotherapy is delivered, all patients should have confirmation of an invasive ovarian, fallopian tube, or peritoneal cancer. Additional information is available at www.asco.org/NACT-ovarian-guideline and www.asco.org/guidelineswiki.
Edmonston vaccine strains of measles virus (MV) have shown significant antitumor activity in preclinical models of ovarian cancer. We engineered MV to express the marker peptide carcinoembryonic antigen (MV-CEA virus) to also permit real-time monitoring of viral gene expression in tumors in the clinical setting. Patients with Taxol and platinum-refractory recurrent ovarian cancer and normal CEA levels were eligible for this phase I trial. Twenty-one patients were treated with MV-CEA i.p. every 4 weeks for up to 6 cycles at seven different dose levels (10 3 -10 9 TCID 50 ). We observed no dose-limiting toxicity, treatment-induced immunosuppression, development of anti-CEA antibodies, increase in anti-MV antibody titers, or virus shedding in urine or saliva. Dose-dependent CEA elevation in peritoneal fluid and serum was observed. Immunohistochemical analysis of patient tumor specimens revealed overexpression of measles receptor CD46 in 13 of 15 patients. Best objective response was dose-dependent disease stabilization in 14 of 21 patients with a median duration of 92.5 days (range, 54-277 days). Five patients had significant decreases in CA-125 levels. Median survival of patients on study was 12.15 months (range, 1.3-38.4 months), comparing favorably to an expected median survival of 6 months in this patient population. Our findings indicate that i.p. administration of MV-CEA is well tolerated and results in dose-dependent biological activity in a cohort of heavily pretreated recurrent ovarian cancer patients. Cancer Res; 70(3); 875-82. ©2010 AACR.
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