GDF15/prothymosin α訊息傳遞路徑之干擾可作為治療經過順鉑化療的膀胱癌患者肌肉消耗的潛在方法

胡哲源¹，歐建慧¹，謝嘉興²

¹成大醫院泌尿部

²衛生福利部台南醫院

GDF15/prothymosin α signaling disruption as a potential therapy for muscle wasting in bladder cancer patients treated with cisplatin

Che-Yuan Hu¹, Chien‑Hui Ou¹, Gia-Shing Shieh²

¹Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan

²Department of Urology, Tainan Hospital, Ministry of Health and Welfare, Executive Yuan, Tainan, Taiwan

Purpose: This study aimed to investigate the changes in GDF15 and prothymosin α (ProT) levels in bladder cancer cells treated with cisplatin, and to elucidate the underlying mechanisms behind these changes. We also aimed to explore the potential impact of these changes on muscle atrophy or cachexia induction in bladder cancer patients treated with cisplatin.

Materials and Methods: We utilized ELISA to measure the serum levels of GDF15 and ProT in a cohort of bladder cancer patients (n=8) and a control group of relatively healthy individuals (n=10). We employed the MTS assay to determine the IC50 of cisplatin on MBT-2 and MB49 bladder cancer cells. We conducted overexpression and knockdown of GDF15 or ProT in tumor cells using lentiviral transduction, followed by treatment with cisplatin. We also utilized conditioned media from cisplatin-treated tumor cells to co-culture with C2C12 muscle cells in order to analyze the production of pro-inflammatory cytokines and muscle atrophy.

Results: Elevated GDF15 and ProT were noted in serum of bladder cancer patients when compared to normal group. GDF15 and ProT also showed a trend of positive correlation. Elevated levels of GDF15 and ProT mRNA were observed in MBT-2 and MB49 bladder cancer cells following treatment with cisplatin. Transfection of ectopic GDF15 into MBT-2 and MB49 cells resulted in a corresponding increase in ProT transcription. Knockdown of GDF15 showed downregulation of ProT. Cisplatin treatment of GDF15-knockdown tumor cells resulted in negligible increase of GDF15 and ProT expression. In contrast, cisplatin treatment of ProT-knockdown tumor cells resulted in sustained low levels of ProT expression, while GDF15 expression still increased. These results suggest that GDF15 acts as an upstream regulator of ProT. The conditioned media from cisplatin-treated MBT-2 and MB49 cells increased the expression of pro-inflammatory cytokines (IL-6, IL-1β, IL-8 and TNF-ɑ) in muscle cells. In animal model, cisplatin treatment in syngeneic bladder tumor in C3H/HeN mice would induce skeletal muscle wasting, but it would be recovered by interruption of GDF15 signaling.

Conclusion: Treatment with cisplatin induced the expression of GDF15 and ProT in bladder cancer cells, resulting in the promotion of proinflammatory cytokine secretion from muscle cells and the development of muscle atrophy.