Expression pattern of p53-binding protein 1 as a new molecular indicator of genomic instability in bladder urothelial carcinoma

Abstract

Copy number alterations and loss of heterozygosity are associated with increasing tumor grade and bladder cancer stage. Our previous study suggested that co-expression of Ki-67 and p53-binding protein 1 (53BP1) could provide an indicator of an abnormal DNA damage response (DDR) pathway. The present study investigated 53BP1 expression as a novel molecular marker in urothelial carcinoma (UC) using bladder tissues with in total of 40 cases including a normal urothelium, urothelial papilloma, low-grade UC, or high-grade UC. Double-label immunofluorescence was used to analyze 53BP1 and Ki-67 expression. This was compared with the level of chromosomal instability and with the expression of other DDR molecules catalytic subunit. This study identified clear differences in the 53BP1 expression patterns in urothelial carcinogenesis, and their close association with genomic instability. 53BP1 abnormal immunoreactivity, particularly with co-localization of Ki-67, was restricted to malignant tissues. Our analyses indicated that a cut-off of >4% of nuclei with 53BP1 abnormal expression plus Ki-67 immunoreactivity distinguished high-grade UC from low-grade UC with 80.0% sensitivity and 100% specificity. We therefore propose that double immunofluorescent analysis of 53BP1 and Ki-67 expression could provide a useful tool to estimate the chromosomal instability and malignant potential of urothelial tumors.

53BP1 expression as a biomarker to differentiate thyroid follicular tumors

“…2). With the hypothesis that the presence of 53BP1 NF can be an indicator of endogenous DNA double-strand breaks and DDR activation in individual cells, we previously demonstrated that the type of 53BP1 expression profiles determined by IF may be useful to estimate GIN during a divergent carcinogenesis in thyroid, skin, uterine cervix, bladder, and esophageal cancer ( 7 , 8 , 9 , 10 , 11 ). Classification of 53BP1 expression into the following five categories: (i) stable (no or faint staining); (ii) low DDR (one or two discrete NF); (iii) high DDR (three or more discrete NF); (iv) large focus (discrete NF ≥1 μm and (v) diffuse (intense and heterogenous expression), showed that both the high DDR and large focus types are closely associated with a higher level of cervical carcinogenesis and high-risk human papilloma virus infection ( 9 , 13 ).…”

“…Classification of 53BP1 expression into the following five categories: (i) stable (no or faint staining); (ii) low DDR (one or two discrete NF); (iii) high DDR (three or more discrete NF); (iv) large focus (discrete NF ≥1 μm and (v) diffuse (intense and heterogenous expression), showed that both the high DDR and large focus types are closely associated with a higher level of cervical carcinogenesis and high-risk human papilloma virus infection ( 9 , 13 ). Instead, both large focus and diffuse types are significantly associated with high-grade urothelial carcinoma showing chromosomal instability and poor prognosis ( 10 ). Moreover, in a rare case of uterine dedifferentiated leiomyosarcoma arising from leiomyoma, we observed that the diffuse 53BP1 expression was restricted only to the sarcoma component, and frequently co-localized with p53 overexpression in sarcoma cells, including highly atypical multinucleated giant cells, suggesting aneuploidy ( 14 ).…”

“…The p53-binding protein 1 (53BP1) is a family of evolutionarily conserved DNA damage response (DDR) molecules, which rapidly localize at the sites of DNA double-strand breaks forming nuclear foci (NF) to co-operatively activate p53 together with other DDR molecules, such as γH2AX and ATM ( 4 , 5 , 6 ). Previously, we demonstrated using immunofluorescence (IF) that the profile of 53BP1 expression, including the number of NF, which reflects the DDR, is clearly altered during tumorigenesis of a diverse cancers, such as thyroid, skin, cervix, bladder, and esophageal carcinomas ( 7 , 8 , 9 , 10 , 11 ). Our more recent study using IF analysis of formalin-fixed paraffin-embedded (FFPE) tissues demonstrated that the number of 53BP1-positive NF increases along with higher malignant potential of thyroid FTs, such as FA, minimally invasive FC, and widely invasive FC ( 12 ).…”

“…Classification of 53BP1 expression into the following five categories: i) stable (no or faint staining); ii) low DDR (one or two discrete NF); iii) high DDR (three or more discrete NF); iv) large focus (discrete NF ≥1 µm; and v) diffuse (intense and heterogenous expression) showed Page 14 of 34 Accepted Manuscript published as EC-20-0630.R1. Accepted for publication: 10-Feb-2021Copyright © 2019 the authors that both the high DDR and large focus types are closely associated with a higher level of cervical carcinogenesis and high-risk human papilloma virus infection (9, 13).Instead, both large focus and diffuse types are significantly associated with high-grade urothelial carcinoma showing chromosomal instability and poor prognosis(10).…”

Association between p53 protein phosphorylated at serine 20 expression and ovarian carcinoma stem cells phenotype: correlation with clinicopathological parameters of ovarian cancer

“…In the current study, a positive correlation between CD133 and Ser20 expression was observed in ovarian carcinomas. The use of double immunostaining technique allows to reveal the co-expression between p-p53(Ser20) and CD133 molecules in single ovarian carcinoma cell [34,35]. The co-expression of p-p53(Ser20) and CD133 molecule was found in ovarian carcinomas with nuclear p53 protein expression, but also was observed in cases without p53 protein expression detected by DO-7 antibody.…”