Efficient inhibition of cervical cancer by dual drugs loaded in biodegradable thermosensitive hydrogel composites

Abstract

Background and purpose: We aimed to explore the anti-tumor effect and mechanism of the combination of cisplatin (DDP)-containing thermosensitive hydrogel (PEG-PCL-PEG, or PECE) and paclitaxel (PTX)-loaded MPEG-PCL polymeric micelles called PDMP on human cervical carcinoma (HeLa) cell. In our previous studies, we found that PDMP in situ treatment of lung cancer will be liable to have potential in Lung cancer patients.

Results: Compared with other treatments, PDMP was most effective in prolonging survival time (P < 0.05), inhibiting tumor growth (P < 0.05), decreasing expression of CD133 (P < 0.05), CD31 (P < 0.05), and aldehyde dehydrogenase 1 (ALDH1) (P > 0.05), inducing G1 phase arrest (P < 0.05), increasing the apoptosis rate (P < 0.05), and in expressing ATM and γ-H2AX (P < 0.05).

Conclusions: PDMP is regarded as a promising anti-tumor reactant, when it comes to the treatment of cervical carcinoma.

Methods: we used a xenograft cervical cancer model to verify the anti-tumor activity of PDMP and to explore its mechanism of action. Mice were intratumorally administered with NS, PECE, PTX+DDP or PDMP. After two days of treatment, three mice per group were sacrificed and tumor tissue was harvested. Levels of histone H2AX phosphorylation (γ-H2AX) were determined by immunohistochemistry and ataxia telangiectasia mutated(ATM) protein levels were measured by western blot analysis. In addition, it would sacrifice each of group of three mice through 10 days' treatment, what's more, it would harvest tumor by virtue of flow cytometry and immunohistochemical analysis. It would like to use there maining mice to analyze tumor growth and survival. The remaining mice were analyzed for tumor growth and survival.

Keywords: cervical cancer; cisplatin; micelles; paclitaxel; thermosensitive hydrogel.

Figure 1. Thermal sensitivity of the injectable PDMP hydrogel composite

Thermal sensitivity of the PECE hydrogel composite (A) and the PDMP hydrogel composite (B) was examined by oscillatory rheological tests.

Figure 2. PDMP inhibited tumor growth in a subcutaneous HeLa model

(A) Suppression of subcutaneous tumor growth by PDMP in mice; (B) Mouse survival curve for each group; PTX, paclitaxel; DDP, cisplatin; PDMP, mixed MPEG-PCL/PTX micelles with DDP-loaded PECE hydrogel.

Figure 3. Immunohistochemical analysis of γ-H2AX, CD133 and CD31 and Western blot of ATM in xenografts from mice in various groups

(A) Immunohistochemical analysis of γ-H2AX, CD133 and CD31 in xenografts from mice in various groups; (B) Western blot of ATM in xenografts from mice in various groups; PTX, paclitaxel; DDP, cisplatin; PDMP, mixing MPEG-PCL/PTX micelles with DDP-loaded PECE hydrogel.

Figure 4. Quantitative analysis of γ-H2AX, CD133 and CD31 in xenografts from mice in various groups

(A) Quantitative analysis of γ-H2AX in xenografts from mice in various groups; (B) Quantitative analysis of CD31 in xenografts from mice in various groups; (C) Quantitative analysis of CD133 in xenografts from mice in various groups; ^*p < 0.05; PTX, paclitaxel; DDP, cisplatin; PDMP, mixed MPEG-PCL/PTX micelles with DDP-loaded PECE hydrogel.

Figure 5. Flow cytometric analysis of tumor tissue from mice that received different treatments

(A) Quantitative analysis of the percentage of cells in G1, S, G2/M phase in xenografts from mice in various groups; (B) Quantitative analysis of the percentage of apoptotic cells in xenografts from mice in various groups; (C) Quantitative analysis of the percentage of ALPH1 in xenografts from mice in various groups; PTX, paclitaxel; DDP, cisplatin; PDMP, mixed MPEG-PCL/PTX micelles with DDP-loaded PECE hydrogel.

Figure 6. Schematic diagram of the PDMP hydrogel complex