PC-Spes is a preparation of eight Chinese herbs, which exhibits antiproliferative and antitumour activity in diverse
cancer types in vivo and in vitro. We exposed the head and neck
squamous carcinoma cell lines (
HNSCC) FADU, HLaC79 and HLaC79-clone1, which is a
paclitaxel-resistant descendant of HLaC79, as well as primary cultured mucosal keratinocytes to increasing concentrations of
paclitaxel and/or
PC-Spes. Growth inhibition was measured using the MTT assay. While FADU and HLaC79 were growth inhibited by
paclitaxel, HLaC79-clone1 cells proved to be resistant against
paclitaxel up to doses of 100 nM, whereas all three cell lines were growth inhibited by
PC-Spes. Interestingly primary keratinocytes were less sensitive to
PC-Spes, they even showed better survivel at low
PC-Spes doses. Furthermore, we analyzed cell cycle distribution, apoptosis and
tubulin expression level and polymerization status in the
HNSCC cell lines.
PC-Spes caused a slight decrease of cells in S/G2 phase in HLaC79-clone1. In FADU and HLaC79 cells the cell cycle was shifted towards S/G2 phase as expected. Apoptosis was initiated in all three cell lines by
PC-Spes, in mucosal keratinocytes, however, it was triggered less distinctively. In summary,
PC-Spes revealed distinct growth inhibition in a
paclitaxel-resistant cell line, whereas primary mucosal keratinocytes were less sensitive.
PC-Spes might therefore provide a therapeutical approach in chemoresistant
head and neck cancer.