SRT1720 inhibits bladder cancer cell progression by impairing autophagic flux.

Bladder cancer (BC) is the most common cancer of the urinary tract, with poor survival, high recurrence rates, and lacking of targeted drugs. In this study, we constructed a library to screen compounds inhibiting bladder cancer cells growth. Among them, SRT1720 was identified to inhibit bladder cancer cell proliferation in vitro and in vivo. SRT1720 treatment also suppressed bladder cancer cells migration, invasion and induced apoptosis. Mechanism studies shown that SRT1720 promoted autophagosomes accumulation by inducing early-stage autophagy but disturbed the late-stage of autophagy by blocking fusion of autophagosomes and lysosomes. SRT1720 appears to induce autophagy related proteins expression and alter autophagy-related proteins acetylation to impede the autophagy flux. LAMP2, an important lysosomal associated membrane protein, may mediate SRT1720-inhibited autophagy flux as SRT1720 treatment significantly deacetylated LAMP2 which may influence its activity. Taken together, our results demonstrated that SRT1720 mediated apoptosis and autophagy flux inhibition may be a novel therapeutic strategy for bladder cancer treatment.

Raltitrexed induces apoptosis through activating ROS-mediated ER stress by impeding HSPA8 expression in prostate cancer cells.

Prostate cancer is the most common malignant tumor in males, which frequently develops into castration-resistant prostate cancer (CRPC). CRPC metastasis is the main reason for its high mortality rate. At present, it lacks effective treatment for patients with CRPC. Raltitrexed (RTX) has been shown to be effective in the treatment of colorectal cancer. However, the effect of RTX on prostate cancer and the underlying mechanism remain unknown. In the current study, we found that RTX could dose-dependently inhibit proliferation, migration, colony formation and induce apoptosis in DU145 and PC-3 cells. RTX also increased ROS generation in prostate cancer cells. Pretreatment with N-acetyl-L-cysteine (NAC) significantly prevented RTX-induced cell apoptosis and endoplasmic reticulum (ER) stress signaling activation in prostate cancer cells. Additionally, we found RTX-induced ROS generation and ER stress activation depended on the expression of heat shock protein family A member 8 (HSPA8). Over-expression of HSPA8 could alleviate RTX-induced cell apoptosis, ROS generation and ER stress signaling activation. Finally, our study also showed that RTX attenuated the tumor growth of prostate cancer in the DU145 xenograft model and significantly downregulated HSPA8 expression and activated ER stress signaling pathway in tumor tissues. Our study is the first to reveal that RTX induces prostate cancer cells apoptosis through inhibiting the expression of HSPA8 and further inducing ROS-mediated ER stress pathway action. This study suggests that RTX may be a novel promising candidate drug for prostate cancer therapy.

Comparison of 3 and 4 cycles of neoadjuvant gemcitabine and cisplatin for muscle-invasive bladder cancer: a systematic review and meta-analysis.

BACKGROUND: In muscle-invasive bladder cancer (MIBC), neoadjuvant chemotherapy (NAC) combined with radical cystectomy (RC) is critical in reducing disease recurrence, with GC (gemcitabine and cisplatin) being one of the most commonly used NACs. Different GC schedules have been used, but the best neoadjuvant regimen is still unknown. The clinical outcomes of 3 and 4 cycles of neoadjuvant GC are compared in this systematic review and meta-analysis to determine which is best for patients with MIBC. METHODS: We searched PubMed, Embase, Web of Science, Cochrane Library, CBM, CNKI, WAN FANG DATA, and meeting abstracts to identify relevant studies up to March 2023. Studies that compared 3 and 4 cycles of neoadjuvant GC for MIBC were included. The primary outcomes were pCR, pDS, OS, and CSS. The secondary outcome was recurrence and SAEs. RESULTS: A total of 3 studies, with 1091 patients, were included in the final analysis. Patients that received 4 cycles of GC had a higher pCR (OR = 0.66; 95% CI, 0.50-0.87; p = 0.003) and pDS (OR = 0.63; 95% CI, 0.48-0.84; p = 0.002) than those who received 3 cycles. Regarding recurrence rate (OR = 1.23; 95% CI, 0.91-1.65; p = 0.18), there were no appreciable differences between the 3 and 4 cycles of GC. Survival parameters such as OS (HR, 1.35; 95% CI, 0.86-2.12; p = 0.19) and CSS (HR, 1.06; 95% CI, 0.82-1.38; p = 0.20) were similar. Only one trial reported on the outcomes of SAEs. And there were no statistically significant differences in thrombocytopenia, infection rate, neutropenic fever, anemia, or decreased renal function between patients. The neutropenia of patients was statistically different (OR = 0.72; 95% CI, 0.52-0.99; p = 0.04). CONCLUSION: The 4-cycle GC regimen was superior to the 3-cycle regimen in only the pCR and pDS results. Survival and recurrence rates were similar between the two regimens. In both treatment regimes, the toxicity profile was manageable. However, due to the inherent drawbacks of retrospective research, this should be regarded with caution.