Table 3.
Cellular characteristics and molecular markers of senescence in wild-type and cancer cells*
| Marker | Marker type | Reference |
| Cellular phenotype | ||
| Morphology† | Visual | (4,6) |
| SA-β-gal activity | Enzyme/staining | (12) |
| Glb1 | RNA, IHC | (86) |
| SSC | Flow cytometry | (4) |
| Proliferation arrest | ||
| BrdU Incorporation | IHC, flow cytometry | (13) |
| DAPI/Hoechst 33342 | DNA stain | (13) |
| Decreased KI-67 | IHC | (15,21) |
| Apoptosis exclusion | ||
| Propidium iodide/annexin V staining | Flow cytometry | (13) |
| Cleaved PARP | IHC, western | (13,21) |
| Cleaved caspase 2/3/9 | IHC, western | (13,21) |
| TUNEL staining | IHC | (21) |
| CKIs | ||
| p16Ink4a | IHC | (5,8,14) |
| p21waf1/cip1 | IHC | (8,45,65) |
| p27kip1 | IHC | (7,8,17) |
| Heterochromatin foci | ||
| DAPI/Hoechst 33342 | DNA Stain | (87) |
| HIRA | IHC | (87) |
| H3K9-methyl3 | IHC | (87) |
| HP1-γ | IHC | (87) |
| Secretory proteins | ||
| IGF2 | RNA, IHC | (50,51) |
| IGFBP3, IGFBP5, IGFBP7 | RNA, IHC | (39,44,50,50) |
| IL-6, IL-8, CXCR2, and others | RNA, IHC | (39,70,88) |
| Miscellaneous | ||
| Versican§ | RNA | (11) |
| CXCL14§ | RNA | (11) |
| Mitochondrial fusion/hFis1/OPA1¶ | IHC | (38) |
| Dec1║ | IHC | (15) |
| DcR2║ | IHC | (15) |
BrdU = bromo-deoxy-uridine; CXCR2 = chemokine (C-X-C motif) receptor 2; CXCL14 = chemokine (C-X-C motif) ligand 14; DAPI = 4′,6-diamidino-2-phenylindole; DcR2 = tumor necrosis factor receptor superfamily, member 10d, decoy truncated death domain; Dec1 = basic helix–loop–helix family, member e40; Glb1 = lysosomal galactosidase 1; H3K9-methyl3 = trimethylated histone 3 at lysine 9; HIRA = HIR histone cell cycle regulation defective homolog A; HP1-γ = histone protein 1-gamma; hFIS1 = human fission 1 homolog; IGF2 = insulinlike growth factor 2; IGFBP = insulinlike growth factor–binding protein; IHC = immunohistochemistry; IL-6 = interleukin 6; IL-8 = interleukin 8; KI-67 = antigen identified by monoclonal antibody Ki-67; OPA1 = optic atrophy 1; PARP = poly-ADP ribosyl polymerase; SA-β-gal = senescence-associated β-galactosidase; SSC = side scatter; TUNEL = terminal deoxynucleotidyl transferase dUTP nick end labeling.
In vitro only.
Marker senescence demonstrated in prostate and prostate cancer only.
Demonstrated in HeLa cells.
Marker may be specific to only nontransformed tissue or fibroblast cells.