Prothymosin-α影響腫瘤包外體內細胞激素並引發膀胱癌惡體質
謝嘉興a、蕭璦莉c、吳昭良b
衛生福利部 台南醫院 泌尿科a, 國立成功大學醫學院 生化所b，國立成功大學醫學院 微免所c
Tumor-originated exosomal prothymosin-α triggers muscle wasting in bladder cancers
Gia-Shing Shieha, Ai-Li Shiauc, and Chao-Liang Wub
a Department of Urology, Tainan Hospital, Ministry of Health and Welfare, Taiwan,
b Department of Biochemistry and Molecular Biology, National Cheng Kung University Medical College, Tainan, Taiwan,
c Department of Microbiology and Immunology, National Cheng Kung University Medical College, Tainan, Taiwan
Purpose: Prothymosin-α (ProT) involved in cell proliferation, apoptosis, oxidative stress, and immunomodulation. In previous study, a statistically significant overexpression of ProT was found in human bladder carcinoma. The cancer-secreted exosomes, which contained proteins, mRNA, miRNAs, and DNAs, were reported for the connection between cancers and distant organs, and supported survival of incoming metastatic cells. Recently, cachexia-inducing tumor cells secreted exosomes to induce muscle wasting in mice and muscle cells. In this study, we will evaluate the relationship between cancer-derived exosomal ProT and muscle cells to induce cachexia-related muscle wasting.
Methods: Human and murine bladder cancer cells were used in the study. Immunohistochemical stain assays were performed for exosome and ProT studies. Real-time RT-PCR assays were performed for ProT, cytokines and HOTAIR expressions. The knockdown expression of ProT was induced via CRISPRi system. Group differences were determined by Student t test. All statistical tests were two-sided.
Result: In human and murine bladder cancer cells, our results demonstrated that ProT activity was higher in cancer- derived exosome than in cytosol. Murine muscle cells (C2C12) could efficiently internalize MBT-2-derived exosomes in dose-dependent manner, and highly expressed exosomal ProT. In addition, MBT-2-derived exosomes significantly stimulate IL-1β, IL-6 and TGF-β productions in C2C12 cells. The exosomes derived from ProT-knockdown MBT-2 cells suppressed inflammation cytokine expressions, such as IL-1β and TGF-β, in C2C12 cells. MBT-2-derived exosomes significantly induced cell death in C2C12 cells.
Conclusion: Our results suggested that exosomal ProT- cytokine-cell death axis played a pivotal role in muscle wasting of cancer cachexia. The inhibition of cancer-derived exosomal ProT and muscle cell interaction provided the therapeutic potential for cancer cachexia.