What's the difference between staurosporine and camptothecin?

The differences between staurosporine (a protein kinase inhibitor) and camptothecin (a topoisomerase inhibitor) is outlined in the table below.

	Staurosporine	Camptothecin
Structure
Molecular Weight	466.53	348.4
Source	Alkaloid isolated from the culture broth of Streptomyces taurosporesa	Cytotoxic plant quinoline alkaloid originally isolated from C. acuminate
Mechanism of action	Inhibition of protein kinases generally: Staurosporine prevents ATP from binding with kinases, arresting cell cycle progression and preventing cells from entering the S-phase.	Inhibits topoisomerase I: Camptothecin binds to the topo I and DNA complex (the covalent complex) resulting in a ternary complex, and thereby stabilizing it. This prevents DNA re-ligation and therefore causes DNA damage which results in apoptosis.
IC50	Kinase C: 0.7nM Neurotrophin: 50-100nM CaM kinase: 20 nM Myosin light chain kinase : 1.3 nM Protein kinase A: 7 nM Protein kinase C: 0.7 nM Protein kinase G: 8.5 nM	Topoisomerase I: 679nm Camptothecin displays cytotoxicity against many human tumor cell lines, including HT29, LOX, SKOV3, and SKVLB, with IC50 values ranging from 37 nM to 48 nM. In combination with TNF, Camptothecin induces apoptosis in primary mouse hepatocytes, with an IC50 value of 13 µM.
Permeability	Cell permeable	Cell permeable
Cell Apoptosis	0.2 ∼ 1 µM, 4 hours	10 - 20 µM, 4-6 hours
Fluorescence	Low background fluorescence in DAPI channel	High background fluorescence in DAPI channel