| Summary: | 碩士 === 中山醫學大學 === 醫學研究所 === 102 === Background: Epirubicin is a common chemotherapy medicine for treating Triple-negative breast cancer (TNBC). In addition to its photosensitivity, epirubicin can be accumulated to a harmful dosage that may cause serious heart problems because of its cardiotoxicity. Therefore, the dosage and the cardiac function need to be closely monitored during and after the treatment. Photodynamic therapy (PDT) has been used to treat various types of cancer, including skin cancer, oral cancer, colorectal cancer, bladder cancer, etc. PDT is a treatment that uses a photosensitizer and a particular type of light. When photosensitizers are exposed to the light, they produce 1O2 or free radical that destroy the cell body or important structures of the cancer cells which will die as a result .The conducting of the experiment is that epirubicin injection is used in combination with photodynamic therapy in hopes of reducing the dosage of epirubicin and thus cardiotoxicity while killing the cancer cells.
Materials and Methods: On TNBC cell lines BT-20, apply different concentration of epirubicin solution, and then apply photodynamic therapy (Epi-PDT). Next, determine how Epi-PDT can lead to cell death by MTT assay (cell viability analysis), annexin V-FITC and PI staining, lactate dehydrogenase (LDH assay), thiobarbituric acid reactive substances (TBARS) assay, and Western blot.
Results: As for cytotoxicity, whether it’s high doses of epirubicin with short exposure to the light or vice versa, Epi-PDT can lead to much less cell viability comparing to solely using of epirubicin. As a result, the experiment shows Epi-PDT does help to increase epirubicin’s curing of cancer: Annexin V-FITC and PI staining shows that Epi-PDT can result in necrosis and apoptosis of the breast cancer cells. Moreover, the increase of necroptosis-related PARP cleavage and the apoptosis-inducing factor (AIF) in nucleus further proves that Epi-PDT can help activate the necrptoosis of the cells. The increasing activation of caspase 8, 9, and 3 during Epi-PDT also serves as a proof that Epi-PDT help induces apoptosis in cells. In Epi-PDT group, the amount of adenosine triphosphate (ATP) molecules is generally decreasing. The result of lipid peroxidation assay also shows that not only TBARS has significantly increased after two hours of light exposure but also lipid peroxidation happens in cells. Lastly, the increase of beclin-1 and LC3BII protein also indicates that Epi-PDT can help activate autophagy of the cells.
Conclusions: According to the findings from the experiment, the combination of photo-sensitive chemotherapy medicine epirubicin with PDT can help reduce the dosage of epirubicin. Epi-PDT can also help lead to physiological mechanism of breast cancer cell death, such as apoptosis, autophagy, and necroptosis. There is currently no other research on the combination of epirubicin with photodynamic therapy in treating triple-negative breast cancer. The findings in this research could serve as future clinical reference for the treatment of triple-negative breast cancer.
|
|---|
