In vitro interaction of cisplatin and fosfomycin on squamous cell carcinoma cultures

The effect of fosfomycin on nedaplatin-induced nephrotoxicity in rats

The effect of coadministration of fosfomycin (FOM) on nedaplatin-induced nephrotoxicity in rats was investigated for 6 days. FOM decreased nedaplatin-induced nephrotoxicity, as shown by reduced blood urea nitrogen (BUN), serum creatinine levels, and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG). Further, there were fewer histopathological signs of nephrotoxicity in the groups treated with the combination of nedaplatin and FOM as compared with the nedaplatin-alone group. The concentration of nedaplatin was significantly lower in the renal cortex of rats treated with the combination of nedaplatin and FOM as compared with those treated with nedaplatin alone (p < 0.05). In conclusion, the concomitant administration of FOM and nedaplatin may help to achieve a chemotherapeutic strategy that reduces the nephrotoxic effects of nedaplatin.

In vivo interaction of cis-platinum and fosfomycin on squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Cis-platinum is the most frequently used chemotherapeutic agent for the treatment of head and neck squamous cell carcinoma (SCCA). Ototoxicity and nephrotoxicity continue to be the primary dose-limiting toxicities encountered. Fosfomycin, a broad-spectrum antibiotic, has been previously shown to be both otoprotective and nephroprotective against cis-platinum toxicity. Previous in vitro work demonstrated that fosfomycin does not inhibit the tumoricidal actions of cis-platinum. This study tests whether fosfomycin inhibits cisplatinum in vivo.

METHODS

An SCCA cell line was grown in vivo in four groups of nude mice, which then received no treatment, standard-dose cis-platinum, high-dose cis-platinum, or high-dose cis-platinum with fosfomycin.

RESULTS

Fosfomycin did not inhibit the tumoricidal activity of cis-platinum. Mice treated with fosfomycin also had longer survival, which is probably due to lessening of immediate cis-platinum systemic toxicity.

CONCLUSION

This study shows that fosfomycin in combination with cis-platinum may be useful in treating advanced, and possibly relatively chemoresistant, SCCA of the head and neck.

Fosfomycin does not inhibit the tumoricidal efficacy of cisplatinum

OBJECTIVES

This study investigates the effect of fosfomycin on the tumoricidal efficacy of cisplatinum.

STUDY DESIGN

Prospective study utilizing the FaDu squamous cell carcinoma cell line and a nude mouse tumor xenograft model.

METHODS

Tumor cell growth was assessed in vitro in the presence of cisplatinum and/or fosfomycin utilizing the MTT assay. An optimal cisplatinum dose and dosing schedule was established in a nude mouse tumor xenograft model of squamous cell carcinoma. Using this model, fosfomycin was tested at three dosages and tumor growth monitored over 4 weeks.

RESULTS

Mice treated with cisplatinum and fosfomycin had smaller tumors than those treated with cisplatinum alone (P<.01).

CONCLUSIONS

This study is the first demonstration that fosfomycin does not inhibit the tumoricidal efficacy of cisplatinum in vivo. This suggests that fosfomycin may be useful in preventing cisplatinum-induced ototoxicity and nephrotoxicity in humans without altering the tumor response rate.