Ab227941

A total of 175 individual cases with formalin-fixed paraffin-embedded (FFPE) tumor blocks were collected. All hematoxylin and eosin-stained slides were reviewed by two professional pathologists. Tissue microarrays (TMAs) of 175 UTUC cases were constructed from the most typical regions of each case. MMR protein IHC was applied to detect the expression of the DNA MMR proteins MLH1 (#ab92312, Abcam, UK), PMS2 (#ab110638, Abcam, UK), MSH2 (#ab227941, Abcam, UK), and MSH6 (#ab92471, Abcam, UK). MMR proteins were considered lost when the tumor nuclei completely lacked staining and a positive internal control was present in the form of lymphocytes and/or endothelial cells.

Antibodies for ATM (2873S; Cell Signaling; 1:1000), 53BP1 (NB100-304; NOVUSBIO; 1:1000), RIF1 (ab1213422; Abcam; 1:500), REV7 (A9861; Abclonal; 1:1000), REV1 (sc-393022; Santa Cruz; 1:1000), REV3L (GTX17515; Gene Tex; 1:1000), AID (A16217; Abclonal; 1:1000), MSH2 (ab227941; Abcam; 1:1000), β-actin (AC028; Abclonal; 1:10,000), FLAG (F1804, Sigma; 1:1000), β-Tubulin (A01030HRP; Abbkine; 1:10,000), glyceraldehyde 3-phosphate dehydrogenase (AB2000; Abways; 1:20,000), and Rabbit TrueBlot (18-8816-33; Ebioscience; 1:1000) were used in western blotting. PE-conjugated anti-mouse IgA (12-4204-83; Ebioscience; 1:200), APC-conjugated anti-mouse IgM (1020-11S; Southern biotech; 1:200), APC-conjugated anti-mouse B220 (553092, BD; 1:200), fluorescein isothiocyanate (FITC)-conjugated anti-mouse IgG1 (553443; BD; 1:200), FITC-conjugated anti-mouse IgG3 (553403; BD; 1:200), APC-eFluor780-conjugated anti-mouse B220 (47-0452-82, Invitrogen; 1:200), FITC-conjugated anti-mouse GL7 (144604, BioLegend; 1 : 200), PE-Cy7-conjugated anti-mouse CD95 (557653, BD; 1:200), and Fluorescein-labeled Peanut Agglutinin (FL-1071, Vector Laboratories; 1:500) were used in the fluorescence-activated cell sorting analysis.