PDT In Combination With Aspirin On Cell Cycle And Apoptosis Of QBC939 Cholangiocarcinoma Cell

Cholangiocarcinoma is a biliary epithelial origin highly invasive malignant tumors, accounting for 10% of liver and gallbladder cancer to 20% [1]. Epidemiological survey shows that the global trend of rising incidence of late bile duct cancer with poor prognosis , the survival of not more than 24 months [2]. surgical resection and liver transplantation is the only way to cure [3]. However, most patients already diagnosed with advanced bile duct cancer, radical surgery can not be done. Therefore, palliative treatments such as endoscopic stent placement, biliary-enteric anastomosis, photodynamic therapy (photodynamic therapy, PDT), chemotherapy and radiotherapy is especially important. For patients with inoperable bile duct cancer treatment, palliative care is to alleviate the primary purpose of obstructive jaundice. As out of control growth characteristics of malignant tumor cells, tumor cells caused by blocked bile duct drainage in a short time, biliary stent, so the drainage operation of the successful completion of drainage often can not bring good results. Chemotherapy and radiotherapy are also used in the treatment of cholangiocarcinoma, although you can prolong the survival time, but due to chemotherapy and radiation therapy side effects, does not improve quality of life. Thus, in the treatment of bile duct cancer, photodynamic therapy as a new, less side effects, and effective treatment can be used repeatedly came into being. It includes non-toxic photosensitizer injection, and then assisted to a certain wavelength of laser light, leading to tumor cell apoptosis [4]. Hematoporphyrin derivative is the most commonly used clinical photosensitizer HPD-mediated PDT in the process there are a lot of signaling molecules regulating, in which the mechanism is still not very clear [5] [6]. The main mechanisms currently accepted are: 1. Direct cell killing mechanism. PDT photosensitizer absorbs the photon energy through the transition to the excited state, resulting in singlet or triplet oxygen, reactive oxygen species composition can be directly on the cell membrane, mitochondria, soluble enzyme membrane, Golgi apparatus, endoplasmic reticulum directly kill tumor cells; 2 . vascular injury mechanisms. Tumor requires a rich blood supply, the study found, photosensitizer can damage the vascular system, this effect is delayed tumor growth; 3. Immune response mechanisms. PDT can activate the body's anti-tumor immune mechanism, this process relies on acute phase protein, protease, peroxidase, reactive oxygen and other substances completed. However, as more and more widely used in PDT treatment of malignant diseases, people gradually realized that a simple application of PDT treatment of malignant tumors in the present context there exists the following deficiencies: 1. Photosensitizer toxicity; 2. Light intensity is not a uniform standard; 3. efficacy is not stability. So, how to make photodynamic therapy efficacy in the tumor more precisely, the treatment effect of sustained and stable, and better mechanisms and other issues is the current hot topic. Through the retrieval and review of the literature, we found that photodynamic therapy of malignant tumors on the latest progress in the Italian scholar Chiaviello [7], etc. in photodynamic therapy of small cell lung cancer found that combination of PDT therapy photosensitizer, reactive oxygen effectively inhibited the formation of proteasome activity, but inhibition of proteasome is short, not enough to make tumor cells because the proteasome activity was inhibited and apoptosis. You can assume that if a method or using drugs in combination of photodynamic therapy to make the activity of the proteasome inhibition by a long time, then it may promote tumor cell apoptosis. Dikshit et al [8] found that brain tumor cells in Neuro 2a and HeLa cervical cancer cells, aspirin can inhibit the function of proteasome induce apoptosis. Above literature shows: photodynamic mechanism of action, in addition to being recognized three kinds there may still light can act Yu proteasome affect the activity of the proteasomeregulator body in the proteasome protein degradation, ultimately lead to tumor cell cycle and apoptosis. There studies showed that aspirin could be acting on the proteasome, in other cell lines, can cause apoptosis. Because photodynamic therapy and aspirin are common in cancer cells the role of targets, likely combined effects of proteasome inhibition on the stronger, more sustained time. The experiment is based on the actuality of cholangiocarcinoma cells in vitro QBC939 photodynamic therapy by simply comparing the treatment cell growth was observed to investigate the effect of simple treatment with combination therapy in contrast to the differences and possible mechanisms .Objective: To investigate photodynamic therapy combined with aspirin on QBC939 cholangiocarcinoma cell cycle and apoptosis and its possible mechanism.Methods: MTT assay photodynamic therapy alone, aspirin therapy, photodynamic therapy combined with aspirin on cell growth inhibition QBC939; flow cytometry cell cycle and apoptosis changes; Western blot cell Cycle-related proteins P27, transcription factor related protein IkBα(P27, IkBαare ubiquitin - proteasome pathway substrate) expression changes.Results: Photodynamic therapy combined with aspirin on QBC939 significantly inhibited cell growth (p <0.01). Flow cytometry results showed that PDT in combination with aspirin can QBC939 cell G0/G1 phase was significantly higher (p <0.01), S phase and G2 / M phase ratio decreased, and caused apoptosis (p <0.01). Photodynamic therapy in combination with aspirin increased protein P27, IkBαexpression, and the role of proteasome inhibitor protein expression after the same.Conclusion: The possible mechanism is by influencing the ubiquitin - proteasome activity on the P27, IkΒαregulate protein expression, the cells arrest in G1 phase, transcription factor NF-κB is not activated, and finally induce apoptosis in cholangiocarcinoma achieved QBC939 .