DNA damage measurements within tissue samples with Repair Assisted Damage Detection (RADD)

Associations between DNA Damage and PD-L1 Expression in Ovarian Cancer, a Potential Biomarker for Clinical Response

“…We previously measured DNA damage in a small cohort of ovarian cancer patients [ 33 ]. Samples from these patients included matched pairs of de-identified ovarian tumors pre-and post-treatment with carboplatin and paclitaxel.…”

“…We conducted a broad spectrum analysis of the persistent DNA damage contained within the 408 samples using the Full RADD cocktail described in Table 1 . This cocktail detects abasic sites, alkylated damage, deamination events, DNA crosslinks, oxidative DNA damage, and strand breaks [ 33 , 34 ]. Using this cocktail, we measured DNA damage levels within the tumor types on the TMA ( Figure 1 ).…”

“…We have previously used individual lesion class cocktails to dissect the predominant lesions in a tumor sample [ 33 ]. Ovarian tissues undergo cycles of oxidative stress during ovulation, so we applied a cocktail specific to oxidative lesions (Fpg, EndoIV, and EndoVIII, termed oxRADD) to specifically examine the content of oxidative lesion with the tumor microarray samples ( Figure 2 ).…”

“…Gain settings for Alexa546 and Alexa647 were determined by examining the TMAs and selecting settings that limited the number of saturated pixels. We used Alexa546 settings similar to our previous work with individual slides of ovarian tumors [ 33 ]. We established the Alexa647 PD-L1 imaging conditions using the LC04 TMA.…”

“…To address this limitation, we have developed a novel technique to measure DNA damage within cells and formalin-fixed paraffin-embedded (FFPE) tissues termed the Repair Assisted Damage Detection (RADD) [ 33 , 34 ]. RADD can measure genomic instability more precisely by measuring the persistent DNA lesions and strand breaks that remain in the genome [ 34 , 35 ].…”