Conclusion
In summary, the strategy of suppressing tumor stroma for subsequent combinational therapies against internal breast tumor cells could provide avenues for management of intractable desmoplastic tumors.
Methods
Glycolipid-based polymeric micelles (GLPM) were developed to encapsulate an angiotensin II receptor I inhibitor (telmisartan, Tel) and a cytotoxic drug (doxorubicin, DOX) respectively, which could exert combinational antitumor efficacy by reprogramming tumor microenvironment to expose the vulnerability of internal tumor cells.
Results
As demonstrated, α-SMA positive CAFs significantly decreased after the pre-administration of GLPM/Tel in vitro, which accordingly inhibited the secretion of the CAFs derived stroma. The tumor vessels were further decompressed as a result of the alleviated solid stress inside the tumor masses, which promoted more intratumoral drug delivery and penetration. Ultimately, staged administration of the combined GLPM/Tel and GLPM/DOX at the screened molar ratio not only inhibited the stroma continuously, but also achieved a synergistic antitumor effect through the apoptosis-related peroxisome proliferator-activated receptor-gamma (PPAR-γ) pathway.