Enhancement of antitumor effects of a new boron compound combined with ultrasound on the mouse ascites tumor.

The use of ultrasound in therapeutic medicine is a developing field. The action of many anticancer agents can be improved with the use of ultrasonic exposure either in vitro or in vivo. Boron-based compounds have shown promising results as chemotherapeutic agents in specific forms of cancer. We synthesized a new boron compound of chloroacetohydroxamic acid, 2-hydroxyamino-oxoethylborate (HAOB). HAOB was used in combination with ultrasound (US) at a frequency of 25 KHz, and inhibitory effects on the growth of mouse ascites tumours were monitored by observing survival time, tumour growth, cell viability and DNA synthesis of treated Ehrlich ascites carcinoma (EAC) cells. 5-Fluorouracil (5-FU) was used as a positive control. The results indicated that HAOB alone produced significant antitumor action whereas combination of US with HAOB or 5-FU produced an extra antitumor action when compared to the actions of HAOB or 5-FU used alone.