[Procyanidins enhance the chemotherapeutic sensitivity of laryngeal carcinoma cells to cisplatin through autophagy pathway].

Objectives: To investigate the effect of Procyanidins (OPCs) on the autophagy of laryngeal cancer cell line TU686 and to explore the effect of OPCs on the chemosensitivity of laryngeal cancer cells to DDP in terms of autophagy and apoptosis.

Methods: CCK-8 was used to detected the effect of different concentrations of OPC and DDP on TU686 cell viability. Experimental grouping: Both kinds of cells were divided into CON group, DDP group, OPC group and MIX group. Annexin-V-FITC/PI double staining of flow cytometry was used to detect the effect of each experimental group on the apoptosis. Cell immunofluorescence staining was used to detect the formation of autophagy. Western blot was used to detect the expression of autophagy-related and apoptosis-related proteins. Autophagy inhibitors (3-MA) were used to study the effect of autophagy on apoptosis.

Results: The results of CCK-8 showed that TU686 cells were inhibited by OPC and DDP in a concentration-dependent manner for 24 hours. LC3-Ⅱ protein staining showed that compared with CON group, DDP group and OPC group, MIX group significantly induced autophagy formation in TU686 cells (<0.05). Flow cytometry showed that compared with CON group, apoptosis of TU686 cells was induced in DDP group, OPC group and MIX group. And the effect of MIX on apoptosis was significantly higher than that of OPC and DDP groups (<0.05). After pretreatment with 3-MA, the apoptotic effect of OPC group and MIX group on TU686 cells was significantly decreased (<0.05). Western blot results showed that the expression of LC3-Ⅱ and Caspase-3 in DDP, OPC and MIX groups was significantly higher than that in CON group (<0.05). In MIX group, the expression of LC3-Ⅱ and Caspase-3 also had significant difference (<0.05) compared with single drug group. After using 3-MA to inhibit autophagy, the expression of LC3-Ⅱ was significantly decreased (<0.05), and the expression of Caspase-3 was decreased along with LC3-Ⅱ, but the decrease of Caspase-3 expression was only significant in OPC and MIX group (<0.05).

Conclusions: OPC can induce autophagy in laryngeal carcinoma TU686 cells and promote its apoptosis, which in turn enhances sensitivity of laryngeal cancer cells to cisplatin chemotherapy.