[The experimental treatment of laryngeal carcinoma with all-trans retinoic acid]

To investigate whether all-trans retinoic acid (RA) has antitumor effect in vivo.

Sixteen nude mice were transplanted with human laryngeal cell carcinoma PHC3. Eight of them were injected with RA intraperitoneally and others with solvent as the control. Response was measured and tumor histopathological features were studied.

The growth and weight of RA-treated tumors were significantly reduced in comparison with those of the control. The growth inhibition rate reached more than 50% in the RA group. Studies also showed that RA-treated cells became well-differentiated. There was a significant decrease of c-myc protein level in the RA treated tumors as compared with the control.

It is suggested that RA could induce differentiation of human laryngeal carcinoma cells and suppress tumor growth in vivo. Regulation of c-myc gene or protein may be related to those happening.