DNA damage and repair in relation to cell killing in neocarzinostatin-treated HeLa cells

Abstract Background DNA in a human cell is subjected to constant assault from both environmental factors and normal metabolic processes. Accumulation of DNA damage drives the progression of many health disorders like aging, cancer, diabetes, and neurodegenerative disorders. Results The present study focuses on the isolation of phenolic compound from the fruit of Terminalia chebula and its protective role on induced DNA damage. Diethyl ether and ethyl acetate extract of Terminalia chebula fruit were subjected to column chromatographic purification, and the fractions obtained were tested for the presence of phenolics. Fraction-12 isolated from diethyl ether extract was identified as gallic acid, which is used for cytotoxic and DNA damage protection activity assays. To select a non-toxic concentration of isolated compound, cytotoxicity was assessed by MTT assay. Gallic acid showed moderate toxicity at the highest concentration tested (i.e., percentage cell viability at 100 μg/ml is 40.51 ± 1.31). Antigenotoxic effect of gallic acid on HeLa cells was carried by alkaline comet assay. The compound showed significant protective abilities against hydrogen peroxide-induced DNA damage in HeLa cells. Conclusion These results show the importance of gallic acid isolated from Terminalia chebula fruit, as protector of oxidative stress-induced DNA damage.

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A Role for Histone H2B During Repair of UV-Induced DNA Damage in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/160.4.1375 ◽

2002 ◽

Vol 160 (4) ◽

pp. 1375-1387

Author(s):

Emmanuelle M D Martini ◽

Scott Keeney ◽

Mary Ann Osley

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Chromatin Structure ◽

Specific Effect ◽

Cell Killing ◽

Cyclobutane Pyrimidine Dimers ◽

Histone H2b ◽

Uv Sensitivity ◽

Pyrimidine Dimers

Abstract To investigate the role of the nucleosome during repair of DNA damage in yeast, we screened for histone H2B mutants that were sensitive to UV irradiation. We have isolated a new mutant, htb1-3, that shows preferential sensitivity to UV-C. There is no detectable difference in bulk chromatin structure or in the number of UV-induced cis-syn cyclobutane pyrimidine dimers (CPD) between HTB1 and htb1-3 strains. These results suggest a specific effect of this histone H2B mutation in UV-induced DNA repair processes rather than a global effect on chromatin structure. We analyzed the UV sensitivity of double mutants that contained the htb1-3 mutation and mutations in genes from each of the three epistasis groups of RAD genes. The htb1-3 mutation enhanced UV-induced cell killing in rad1Δ and rad52Δ mutants but not in rad6Δ or rad18Δ mutants, which are defective in postreplicational DNA repair (PRR). When combined with other mutations that affect PRR, the histone mutation increased the UV sensitivity of strains with defects in either the error-prone (rev1Δ) or error-free (rad30Δ) branches of PRR, but did not enhance the UV sensitivity of a strain with a rad5Δ mutation. When combined with a ubc13Δ mutation, which is also epistatic with rad5Δ, the htb1-3 mutation enhanced UV-induced cell killing. These results suggest that histone H2B acts in a novel RAD5-dependent branch of PRR.

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Piperlongumine inhibits migration and proliferation of castration-resistant prostate cancer cells via triggering persistent DNA damage

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-021-03369-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ding-fang Zhang ◽

Zhi-chun Yang ◽

Jian-qiang Chen ◽

Xiang-xiang Jin ◽

Yin-da Qiu ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Proliferation ◽

Dna Damage ◽

Cell Adhesion ◽

Anticancer Activity ◽

Cancer Cells ◽

Castration Resistant Prostate Cancer ◽

Prostate Cancer Cells ◽

Dna Damage And Repair ◽

Castration Resistant

Abstract Background Metastatic castration-resistant prostate cancer (CRPC) is the leading cause of death among men diagnosed with prostate cancer. Piperlongumine (PL) is a novel potential anticancer agent that has been demonstrated to exhibit anticancer efficacy against prostate cancer cells. However, the effects of PL on DNA damage and repair against CRPC have remained unclear. The aim of this study was to further explore the anticancer activity and mechanisms of action of PL against CRPC in terms of DNA damage and repair processes. Methods The effect of PL on CRPC was evaluated by MTT assay, long-term cell proliferation, reactive oxygen species assay, western blot assay, flow cytometry assay (annexin V/PI staining), β-gal staining assay and DAPI staining assay. The capacity of PL to inhibit the invasion and migration of CRPC cells was assessed by scratch-wound assay, cell adhesion assay, transwell assay and immunofluorescence (IF) assay. The effect of PL on DNA damage and repair was determined via IF assay and comet assay. Results The results showed that PL exhibited stronger anticancer activity against CRPC compared to that of taxol, cisplatin (DDP), doxorubicin (Dox), or 5-Fluorouracil (5-FU), with fewer side effects in normal cells. Importantly, PL treatment significantly decreased cell adhesion to the extracellular matrix and inhibited the migration of CRPC cells through affecting the expression and distribution of focal adhesion kinase (FAK), leading to concentration-dependent inhibition of CRPC cell proliferation and concomitantly increased cell death. Moreover, PL treatment triggered persistent DNA damage and provoked strong DNA damage responses in CRPC cells. Conclusion Collectively, our findings demonstrate that PL potently inhibited proliferation, migration, and invasion of CRPC cells and that these potent anticancer effects were potentially achieved via triggering persistent DNA damage in CRPC cells.

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