Going Ape as an Approach to Cancer Therapeutics

Bapat, Aditi; Fishel, Melissa L.; Kelley, Mark R.

doi:10.1089/ars.2008.2218

Cited by 96 publications

(115 citation statements)

References 136 publications

(246 reference statements)

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“…Only the highest concentration (50 μM) shows a statistically significant (21%) increase in damage over the control, whereas DOPA and MYR induce a 48% and 50% increase in damage, respectively, at 10-fold lower concentrations. Interestingly, two studies have reported no effect on cell survival when using NCA with DNA damaging agents (43,45). Our results suggest that NCA may have some effect on cells, but both DOPA and MYR are far more potent.…”

Section: Resultsmentioning

confidence: 49%

Single cell trapping and DNA damage analysis using microwell arrays

Wood

Weingeist

Bhatia

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

242

284

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With a direct link to cancer, aging, and heritable diseases as well as a critical role in cancer treatment, the importance of DNA damage is well-established. The intense interest in DNA damage in applications ranging from epidemiology to drug development drives an urgent need for robust, high throughput, and inexpensive tools for objective, quantitative DNA damage analysis. We have developed a simple method for high throughput DNA damage measurements that provides information on multiple lesions and pathways. Our method utilizes single cells captured by gravity into a microwell array with DNA damage revealed morphologically by gel electrophoresis. Spatial encoding enables simultaneous assays of multiple experimental conditions performed in parallel with fully automated analysis. This method also enables novel functionalities, including multiplexed labeling for parallel single cell assays, as well as DNA damage measurement in cell aggregates. We have also developed 24-and 96-well versions, which are applicable to high throughput screening. Using this platform, we have quantified DNA repair capacities of individuals with different genetic backgrounds, and compared the efficacy of potential cancer chemotherapeutics as inhibitors of a critical DNA repair enzyme, human AP endonuclease. This platform enables high throughput assessment of multiple DNA repair pathways and subpathways in parallel, thus enabling new strategies for drug discovery, genotoxicity testing, and environmental health.base excision repair | comet assay | DNA repair D NA damage is a critical risk factor for cancer, aging, and heritable diseases (1-3), and it is the underlying basis for most frontline cancer therapies (4). Increased knowledge about DNA damage and repair would facilitate disease prevention, identification of individuals at increased risk of cancer, discovery of novel therapeutics, and better drug safety testing. Despite their obvious translational impact, most DNA damage assays have not changed significantly in more than two decades, and thus are not compatible with modern high throughput screening technologies. To better assess the biological impact of damage, we need data that reflect the integrated effect of multiple DNA repair pathways and subpathways, in response to a range of DNA lesions, measured in an accurate and high throughput fashion.The single cell gel electrophoresis or "comet" assay is based on the principle that relaxed loops (induced by single strand breaks) and DNA fragments migrate farther in an agarose gel than undamaged DNA (5-8). The alkali comet assay sensitively detects a range of DNA lesions, including strand breaks (single and double), as well as alkali sensitive sites. Although most base lesions are not directly detected, base adducts can be detected when converted to abasic sites or single strand breaks with the addition of purified DNA repair enzymes (7-11). The comet assay has been used in a variety of applications, including genotoxicity testing, human biomonitoring and epidemiology, environmental healt...

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Section: Resultsmentioning

confidence: 49%

Single cell trapping and DNA damage analysis using microwell arrays

Wood

Weingeist

Bhatia

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

242

284

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“…Elevated levels of Ape1 have been linked to resistance to chemotherapy and poor prognosis (Bapat et al, 2008), and inhibition of Ape1 DNA repair activity and/ or its redox activity may be a promising avenue to develop novel cancer therapeutics and chemoprevention. Therefore, we speculate that inhibition of Ape1 redox activity may enhance cisplatin sensitivity to kill lung cancer with cytoplasmic Ape1.…”

Section: Discussionmentioning

confidence: 99%

Subcellular localization of apurinic endonuclease 1 promotes lung tumor aggressiveness via NF-κB activation

Cheng

Chang

et al. 2010

Oncogene

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Apurinic endonuclease 1 (Ape1) is not only involved in base excision repair, but also activates some transcriptional factors through its redox activity. However, which subcellular localization of Ape1 is involved in the activation of transcriptional factor remains unclear. We first observed that Cox-2 expression was associated with cytoplasmic Ape1 expression in lung tumors and cancer cell lines. We thus hypothesize that nuclear factor (NF)-jB is activated by cytoplasmic Ape1 to cause Cox-2 expression. Herein, we generated cytoplasmic and nuclear Ape1 in Ape1-knockdown lung cancer cells by exogenous expression of Ape1 containing various deletions and/or mutations of the nuclear localization sequence. It was observed that cytoplasmic Ape1, but not nuclear Ape1, induced Cox-2 expression through NF-jB activation. NF-jB activation by cytoplasmic Ape1 was diminished by the Ape1 redox activity inhibitor resveratrol. Cells expressing cytoplasmic Ape1 exhibited tumor progression and metastasis in vitro and in vivo as xenografts, but cells expressing nuclear Ape1 did not. Patients with tumors containing elevated cytoplasmic Ape1 had a poor prognosis and a 3.722-fold risk of tumor recurrence and/or metastasis. Cytoplasmic Ape1 could therefore enhance lung tumor malignancy through NF-jB activation, suggesting that combination of cisplatin and specific redox inhibitor could improve chemotherapeutic response in patients with tumors containing elevated cytoplasmic Ape1.

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“…These genotoxic agents are administered to cancer patients in combination, and in some cases with small molecule inhibitors to block DNA repair pathways with the aim of sensitizing cancer cells towards the chemotherapeutic regimens [4][5][6][7][8]. Although these molecules are hydrophilic in nature, it was commonly accepted that they diffuse into cells.…”

Section: Introductionmentioning

confidence: 99%