DNA damage recognition via activated ATM and p53 pathway in nonproliferating human prostate tissue.
DNA damage response (DDR) pathways have been extensively studied in cancer cell lines and mouse models, but little is known about how DNA damage is recognized by different cell types in nonmalignant, slowly replicating human tissues. Here, we assess, using ex vivo cultures of human prostate tissue, DDR caused by cytotoxic drugs (camptothecin, doxorubicin, etoposide, and cisplatin) and ionizing radiation (IR) in the context of normal tissue architecture. Using specific markers for basal and luminal epithelial cells, we determine and quantify cell compartment-specific damage recognition. IR, doxorubicin, and etoposide induced the phosphorylation of H2A.X on Ser(139) (γH2AX) and DNA damage foci formation. Surprisingly, luminal epithelial cells lack the prominent γH2AX response after IR when compared with basal cells, although ATM phosphorylation on Ser(1981) and 53BP1 foci were clearly detectable in both cell types. The attenuated γH2AX response seems to result from low levels of total H2A.X in the luminal cells. Marked increase in p53, a downstream target of the activated ATM pathway, was detected only in response to camptothecin and doxorubicin. These findings emphasize the diversity of pathways activated by DNA damage in slowly replicating tissues and reveal an unexpected deviation in the prostate luminal compartment that may be relevant in prostate tumorigenesis. Detailed mapping of tissue and cell type differences in DDR will provide an outlook of relevant responses to therapeutic strategies.
Jäämaa
Sari
S
Biomedicum Helsinki and Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland.
Af Hällström
Taija M
TM
Sankila
Anna
A
Rantanen
Ville
V
Koistinen
Hannu
H
Stenman
Ulf-Håkan
UH
Zhang
Zhewei
Z
Yang
Zhiming
Z
De Marzo
Angelo M
AM
Taari
Kimmo
K
Ruutu
Mirja
M
Andersson
Leif C
LC
Laiho
Marikki
M
D000970:Antineoplastic Agents / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism*; D004249:DNA Damage / Q000502:physiology* / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D010766:Phosphorylation / Q000528:radiation effects; D011467:Prostate / Q000378:metabolism* / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011839:Radiation, Ionizing; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D000071857:Tumor Suppressor p53-Binding Protein 1
D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C468783:H2AX protein, human; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; C495901:TP53 protein, human; C498301:TP53BP1 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D000071857:Tumor Suppressor p53-Binding Protein 1; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases