RESUMEN
BACKGROUND@#Bladder cancer, characterized by a high potential of tumor recurrence, has high lifelong monitoring and treatment costs. To date, tumor cells with intrinsic softness have been identified to function as cancer stem cells in several cancer types. Nonetheless, the existence of soft tumor cells in bladder tumors remains elusive. Thus, our study aimed to develop a micro-barrier microfluidic chip to efficiently isolate deformable tumor cells from distinct types of bladder cancer cells.@*METHODS@#The stiffness of bladder cancer cells was determined by atomic force microscopy (AFM). The modified microfluidic chip was utilized to separate soft cells, and the 3D Matrigel culture system was to maintain the softness of tumor cells. Expression patterns of integrin β8 (ITGB8), protein kinase B (AKT), and mammalian target of rapamycin (mTOR) were determined by Western blotting. Double immunostaining was conducted to examine the interaction between F-actin and tripartite motif containing 59 (TRIM59). The stem-cell-like characteristics of soft cells were explored by colony formation assay and in vivo studies upon xenografted tumor models.@*RESULTS@#Using our newly designed microfluidic approach, we identified a small fraction of soft tumor cells in bladder cancer cells. More importantly, the existence of soft tumor cells was confirmed in clinical human bladder cancer specimens, in which the number of soft tumor cells was associated with tumor relapse. Furthermore, we demonstrated that the biomechanical stimuli arising from 3D Matrigel activated the F-actin/ITGB8/TRIM59/AKT/mTOR/glycolysis pathways to enhance the softness and tumorigenic capacity of tumor cells. Simultaneously, we detected a remarkable up-regulation in ITGB8, TRIM59, and phospho-AKT in clinical bladder recurrent tumors compared with their non-recurrent counterparts.@*CONCLUSIONS@#The ITGB8/TRIM59/AKT/mTOR/glycolysis axis plays a crucial role in modulating tumor softness and stemness. Meanwhile, the soft tumor cells become more sensitive to chemotherapy after stiffening, that offers new insights for hampering tumor progression and recurrence.
Asunto(s)
Animales , Ratones , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Actinas/metabolismo , Recurrencia Local de Neoplasia , Serina-Treonina Quinasas TOR/metabolismo , Neoplasias de la Vejiga Urinaria , Glucólisis , Línea Celular Tumoral , Proliferación Celular , Mamíferos/metabolismo , Proteínas de Motivos Tripartitos/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Cadenas beta de IntegrinasRESUMEN
BACKGROUND@#Studies have classified muscle-invasive bladder cancer (MIBC) into primary (initially muscle-invasive, PMIBC) and secondary subtypes (initially non-muscle-invasive but progresses, SMIBC), for which controversial survival outcomes were demonstrated. This study aimed to compare the survival outcomes between PMIBC and SMIBC patients in China.@*METHODS@#Patients diagnosed with PMIBC or SMIBC at West China Hospital from January 2009 to June 2019 were retrospectively included. Kruskal-Wallis and Fisher tests were employed to compare clinicopathological characteristics. Kaplan-Meier curves and Cox competing proportional risk model were used to compare survival outcomes. Propensity score matching (PSM) was employed to reduce the bias and subgroup analysis was used to confirm the outcomes.@*RESULTS@#A total of 405 MIBC patients were enrolled, including 286 PMIBC and 119 SMIBC, with a mean follow-up of 27.54 and 53.30 months, respectively. The SMIBC group had a higher proportion of older patients (17.65% [21/119] vs. 9.09% [26/286]), chronic disease (32.77% [39/119] vs . 22.38% [64/286]), and neoadjuvant chemotherapy (19.33% [23/119] vs . 8.04% [23/286]). Before matching, SMIBC had a lower risk of overall mortality (OM) (hazard ratios [HR] 0.60, 95% confidence interval [CI] 0.41-0.85, P = 0.005) and cancer-specific mortality (CSM) (HR 0.64, 95% CI 0.44-0.94, P = 0.022) after the initial diagnosis. However, higher risks of OM (HR 1.47, 95% CI 1.02-2.10, P = 0.038) and CSM (HR 1.58, 95% CI 1.09-2.29, P = 0.016) were observed for SMIBC once it became muscle-invasive. After PSM, the baseline characteristics of 146 patients (73 for each group) were well matched, and SMIBC was confirmed to have an increased CSM risk (HR 1.83, 95% CI 1.09-3.06, P = 0.021) than PMIBC after muscle invasion.@*CONCLUSIONS@#Compared with PMIBC, SMIBC had worse survival outcomes once it became muscle-invasive. Specific attention should be paid to non-muscle-invasive bladder cancer with a high progression risk.