Cell lines

SK-LMS-1 leiomyosarcoma (MGMT-/p53+), Ewing sarcoma A-673 and GIST-T1 (both lines with MGMT+/p53- phenotype), and glioblastoma T98G (MGMT+/p53+)

Preparation method

The solubility of this compound in DMSO is >6.6mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

62.5, 125, 250 and 500 μM; 72 h

Applications

In SK-LMS-1 cells, Temozolomide inhibited proliferative activity of SK-LMS-1 cells. A-673 cells was most sensitive to temozolomide, the effect was time- and dose-dependent. Preincubation of Ewing sarcoma cells with O6-benzylguanine potentiated the cytotoxic effect of the alkylating agent and reduced viability of tumor cells. GIST-T1 cells were insensitive to temozolomide.

Animal models

PARP1 wild‐ ype (WT) and PARP1 knock‐out (KO) mice

Dosage form

68 mg/kg; once daily for 5 days; orally administrated

Application

In PARP1 WT mice, temozolomide significantly lowered concentrations of NAD+ in the liver when compared with the control group (by 22%, p = 0.02). In the livers of PARP1 KO mice, there was also a statistically significant reduction in NAD+ in the temozolomide‐only group when compared with the control (by 22%, p = 0.03).

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

Temozolomide (NSC 362856; CCRG 81045) is an oral DNA alkylating agent used to treat some brain cancers.
Temozolomide (TZM) is a methylating agent that crosses the blood-brain barrier and is indicated for malignant gliomas and metastatic melanomas. Temozolomide is effective against tumor cells that are characterized by low levels of O6-alkylguanine DNA alkyltransferase (OGAT) and a functional mismatch repair system (MR)[1]. Determination of the IC50 for Temozolomide (TZM) in different cell lines gave values ranging from 14.1 to 234.6 μM that fell into two clearly differentiated groups: cell lines with low IC50 values (<50 μM), which include A172 (14.1±1.1 μM) and LN229 cells (14.5±1.1 μM), and those with high IC50 values (>100 μM), which include SF268 (147.2±2.1 μM) and SK-N-SH cells (234.6±2.3 μM)[2].
Temozolomide (TZM), as a single agent, does not significantly increase mdian survival time (MST) with respect to control. Noteworthy, intracranial injection of NU1025, immediately before the administration of 100 or 200 mg/kg Temozolomide, significantly increases lifespans with respect to controls or to groups treated with Temozolomide only. When Temozolomide is fractionated, the increase in lifespan (ILS) obtained with this schedule is higher than that observed when NU1025 is combined with a single injection of Temozolomide (statistical comparison of survival curves: NU1025 intracranially+Temozolomide 100 mg/kg×2 vs NU1025+Temozolomide 200 mg/kg; P=0.023)[1].
Reference：
[1]. Tentori L, et al. Combined treatment with temozolomide and poly(ADP-ribose) polymerase inhibitor enhances survival of mice bearing hematologic malignancy at the central nervous system site. Blood. 2002 Mar 15;99(6):2241-4.
[2]. Perazzoli G, et al. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression. PLoS One. 2015 Oct 8;10(10):e0140131.