Table 2. Potential biomarkers of Chk1 inhibition.
| Biomarker | Rationale | Expected outcomea |
|---|---|---|
| Chk1 phosphoserine 296 | Chk1 autophosphorylation site | ↓ |
| Chk1 phosphoserine 345 | Chk1 activation site | ↑ or ↓, depending on properties of specific inhibitor |
| γH2AX | Activated at sites of DNA damage | ↑ |
| Phosphohistone H3 | Marker of mitotic entry | ↑ |
| CDC25C phosphoserine 216 | Negative regulation of CDC25C phosphatase, causing G2 arrest | ↓ |
Chk1=checkpoint kinase-1.
a
Expected outcome with addition of Chk1 inhibitor to chemotherapy-treated cells.