method-for-obtaining-primary-ovarian-cancer-cells-from-solid-specimens

Method for Obtaining Primary Ovarian Cancer Cells From Solid Specimens

Reliable tools for investigating ovarian cancer initiation and progression are urgently needed. While the use of ovarian cancer cell lines remains a ...

method-for-measuring-activity-deubiquitinating-enzymes-cell-lines

Method for Measuring the Activity of Deubiquitinating Enzymes in Cell Lines and Tissue Samples

The ubiquitin-proteasome system has recently been implicated in various pathologies including neurodegenerative diseases and cancer. In light of this, ...

University of Minnesota

We have shown that sesame lignans added to rat diet resulted in significantly greater plasma and tissue concentrations of alpha- and gamma-tocopherol concentrations in supplemented rats than in rats without supplementation. In the present studies we examined whether sesaminol, a sesame lignan, enhances tocotrienol concentrations in plasma and tissues of rats fed diets containing a tocotrienol-rich fraction of palm oil (T-mix). In Experiment 1, effects of sesaminol on tocotrienol concentrations in plasma, liver, and kidney were evaluated in rats fed diets containing 20 mg/kg of T-mix (20T) and 50 mg/kg of T-mix (50T) with or without 0.1% sesaminol. Although the T-mix contained 23% alpha-tocopherol, 22% alpha-tocotrienol, and 34% gamma-tocotrienol, alpha-tocopherol constituted most or all of the vitamin E in plasma and tissue (from 97% in kidney to 100% in plasma), with no or very little alpha-tocotrienol and no gamma-tocotrienol at all. Addition of sesaminol to the T-mix resulted in significantly higher plasma, liver, and kidney alpha-tocopherol concentrations compared to values for T-mix alone. Further, T-mix with sesaminol resulted in significantly higher alpha-tocotrienol concentrations in kidney, although the concentration was very low. In Experiment 2, we examined whether sesaminol caused enhanced absorption of alpha-tocopherol and alpha-tocotrienol in a dosage regimen supplying T-mix and sesaminol on alternating days and observed significantly higher levels of alpha-tocopherol and alpha-tocotrienol in rats fed sesaminol, even without simultaneous intake, compared to those in rats without sesaminol. In Experiment 3, alpha-tocopherol was supplied to the stomach with and without sesaminol, and alpha-tocopherol concentrations in the lymph fluid were measured. a-Tocopherol concentrations were not different between groups. These results indicated that sesaminol produced markedly higher alpha-tocopherol concentrations in plasma and tissue and significantly greater alpha-tocotrienol concentrations in kidney and various other tissues, but the concentrations of alpha-tocotrienol were extremely low compared to those of a-tocopherol (Exps. 1 and 2). However, the sesaminol-induced increases of a-tocopherol and a-tocotrienol concentrations in plasma and tissue were not caused by their enhanced absorption since sesaminol did not enhance their absorption.

Effect of sesaminol on plasma and tissue alpha-tocopherol and alpha-tocotrienol concentrations in rats fed a vitamin E concentrate rich in tocotrienols.

Cervical cancer cells exhibit an increased requirement for ubiquitin-dependent protein degradation associated with an elevated metabolic turnover rate, and for specific signaling pathways, notably HPV E6-targeted degradation of p53 and PDZ proteins. Natural compounds with antioxidant properties including flavonoids and triterpenoids hold promise as anticancer agents by interfering with ubiquitin-dependent protein degradation. An increasing body of evidence indicates that their α-β unsaturated carbonyl system is the molecular determinant for inhibition of ubiquitin-mediated protein degradation up-stream of the catalytic sites of the 20S proteasome. Herein we report the identification and characterization of a new class of chalcone-based, potent and cell permeable chemical inhibitors of ubiquitin-dependent protein degradation, and a lead compound RAMB1. RAMB1 inhibits ubiquitin-dependent protein degradation without compromising the catalytic activities of the 20S proteasome, a mechanism distinct from that of Bortezomib. Treatment of cervical cancer cells with RAMB1 triggers unfolded protein responses, including aggresome formation and Hsp90 stabilization, and increases p53 steady state levels. RAMB1 treatment results in activation of lysosomal-dependent degradation pathways as a mechanism to compensate for increasing levels of poly-ubiquitin enriched toxic aggregates. Importantly, RAMB1 synergistically triggers cell death of cervical cancer cells when combined with the lysosome inhibitor Chloroquine.

Stressing the ubiquitin-proteasome system without 20S proteolytic inhibition selectively kills cervical cancer cells.

Ovarian cancer is the deadliest of the gynecological diseases and the fifth cause of cancer death among American women. This is mainly due to the lack of prognostic tools capable of detecting early stages of ovarian cancer and to the high rate of resistance to the current chemotherapeutic regimens. In this scenario the overall 5-year survival rate for ovarian cancer patients diagnosed at late stage is less than 25%. Abnormalities associated with the malignant phenotype and the mechanisms of tumor progression are not clearly understood. In vitro studies are necessary, yet have been hampered due to the limitations accompanied with the use of ovarian cancer cell lines and the heterogeneity of the ovarian cancer cell population derived from ascites fluids. In this study we present a simple, rapid and reproducible method for the isolation and characterization of ovarian cancer cells from solid tumor tissue and show that enzymatic digestion for 30 minutes with dispase II results in the most effective recovery of viable epithelial ovarian cancer (EOC) cells. The resulting cancer (EOC) cell preparations demonstrate a significant yield, high levels of viability and are fibroblast-free. They grow for up to six passages and retain the capacity of forming spheroids-like structures in agarose. In addition, they can be genetically manipulated and used for drug screening, thus rendering them highly suitable for downstream applications. Notably, isolation of ovarian cancer cells from solid specimens using this method has the advantage of allowing for isolation of cancer cells from early stages of ovarian cancer as well as obtaining cells from defined either primary and/or metastatic ovarian cancer sites. Thus, these cells are highly suitable for investigations aimed at understanding ovarian cancer.

Establishment, characterization and downstream application of primary ovarian cancer cells derived from solid tumors.

Ovarian cancer is the deadliest of the gynecologic malignancies. Carcinogenic progression is accompanied by upregulation of ubiquitin-dependent protein degradation machinery as a mechanism to compensate with elevated endogenous proteotoxic stress. Recent studies support the notion that deubiquitinating enzymes (DUB) are essential factors in proteolytic degradation and that their aberrant activity is linked to cancer progression and chemoresistance. Thus, DUBs are an attractive therapeutic target for ovarian cancer.

Small-molecule RA-9 inhibits proteasome-associated DUBs and ovarian cancer in vitro and in vivo via exacerbating unfolded protein responses.

Breast cancer is one of the leading causes of cancer death among women in the United States. Patients expressing the estrogen and progesterone receptor (ER and PR) and human epidermal growth factor 2 (HER-2) tumor markers have favorable prognosis and efficacious therapeutic options. In contrast, tumors that are negative for these markers (triple-negative) have a disproportionate share of morbidity and mortality due to lack of a validated molecular target. Deubiquitinating enzymes (DUBs) are a critical component of ubiquitin-proteasome-system degradation and have been shown to be differentially expressed and activated in a number of cancers, including breast, with their aberrant activity linked to cancer prognosis and clinical outcome. We evaluated the effect of the DUB inhibitors b-AP15 and RA-9 alone and in combination with early- and late-stage lysosomal inhibitors on cell viability in a panel of triple negative breast cancer (TNBC) cell lines. Our results indicate small-molecule DUB inhibitors have a profound effect on TNBC viability and lead to activation of autophagy as a cellular mechanism to compensate for ubiquitin-proteasome-system stress. Treatment with sub-optimal doses of DUB and lysosome inhibitors synergistically kills TNBC cells. This supports the evaluation of DUB inhibition, in combination with lysosomal inhibition, as a therapeutic approach for the treatment of TNBC.

ArticleTotal : 2	Year
Publication title Cited by 13	2014
Publication title Cited by 4	2015

Article	Year
Effect of sesaminol on plasma and tissue alpha-tocopherol and alpha-tocotrienol concentrations in rats fed a vitamin E concentrate rich in tocotrienols. Lipids\| PubMed ID: 12030315	2002
Stressing the ubiquitin-proteasome system without 20S proteolytic inhibition selectively kills cervical cancer cells. PloS one\| PubMed ID: 21909374	2011
Establishment, characterization and downstream application of primary ovarian cancer cells derived from solid tumors. PloS one\| PubMed ID: 23226302	2012
Small-molecule RA-9 inhibits proteasome-associated DUBs and ovarian cancer in vitro and in vivo via exacerbating unfolded protein responses. Clinical cancer research : an official journal of the American Association for Cancer Research\| PubMed ID: 24727327	2014
Simultaneous inhibition of deubiquitinating enzymes (DUBs) and autophagy synergistically kills breast cancer cells. Oncotarget\| PubMed ID: 25784654	2015

Yoshie Iizuka

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