[LncRNA SOX2OT enhances 5-fluorouracil resistance of cholangiocarcinoma cells by promoting autophagy via up-regulating SIRT1 expression]

OBJECTIVE

To investigate the role of SIRT1/autophagy pathway in mediating the regulatory effect of lncRNA SOX2OT on 5-fluorouracil (5-FU) resistance in cholangiocarcinoma cells.

METHODS

HCCC-9810 cells were used to construct a 5-FU-resistant cell model (HCCC-9810/5-FU cells), and the expression levels of lncRNA SOX2OT and SIRT1 mRNA and the protein expressions of SIRT1, Beclin1, LC3 and P62 were detected with qRT-PCR and Western blotting. The effects of transfection with a SOX2OT mimic on drug resistance and cell migration of HCCC-9810/5-FU cells were detected using CCK-8 assay and wound healing assay, and the changes in expressions of SOX2OT, SIRT1, Beclin1, LC3 and P62 were detected. Rescue experiment was performed by co-transfection of HCCC-9810/5-FU cells with both a SOX2OT-overexpressing plasmid and si-SIRT1 to confirm the role of SIRT1 in SOX2OT-mediated regulation of 5-FU resistance. A RNA pulldown assay was used to verify the targeted binding between SOX2OT and SIRT1.

RESULTS

The proliferation of HCCC-9810 cells was significantly inhibited after treatment with different concentrations of 5-FU (P < 0.05). The 5-FU-resistant cells showed significantly increased protein expressions of SIRT1, Beclin1 and p62, an increased LC3 Ⅱ/LC3 Ⅰ ratio, and enhanced expressions of SIRT1 mRNA and SOX2OT (P < 0.05). Transfection of the resistant cells with SOX2OT mimic significantly enhanced cell migration and increased the protein expressions of SIRT1, Beclin1 and p62, the LC3Ⅱ/LC3Ⅰ ratio, and expression levels of SIRT1 mRNA and SOX2OT (P < 0.05), and these changes were obviously attenuated by SIRT1 knockdown, which also resulted in lowered 5-FU resistance of the cells without significantly affecting the expression level of SOX2OT (P > 0.05). RNA pulldown assay suggested that SOX2OT could directly bind to SIRT1.

CONCLUSION

LncRNA SOX2OT enhances 5-FU resistance in HCCC-9810 cells by promoting autophagy through up-regulating SIRT1 expression.

[Feasibility Study of Ultra-High-Resolution Low-Dose Temporal Bone CT with 1 024×1 024 Reconstruction Matrix Size]

OBJECTIVE

To investigate the feasibility of low-dose CT scan of the temporal bone combined with reconstruction matrix size of 1 024×1 024 and the effect of the reconstruction matrix size on image quality.

METHODS

Normal-dose and low-dose bilateral temporal bone CT scans were performed on twelve adult male cadaveric skull specimens using the 160-slice multi-detector CT scanning of United Imaging Healthcare. Normal-dose CT images were reconstructed with matrix sizes of 512×512 and 1 024×1 024, while low-dose CT images were reconstructed with the matrix size of 1 024×1 024. CT value, noise, signal-to-noise ratio, contrast-to-noise ratio, the visualization scoring of 15 anatomical structures of the temporal bone, and the result of three-dimensional reconstruction of the ossicular chain were compared among the three groups.

RESULTS

The radiation dose of low-dose CT scanning was reduced by about 50% compared with that of normal-dose CT. There was no significant difference in CT values of air, soft tissues and bones among the three groups. Low-dose temporal bone CT with the matrix size of 1 024×1 024 had higher noise, but much better visualization of temporal bone structure than the normal-dose temporal bone CT with matrix size of 512×512. Both the three-dimensional reconstructions of normal-dose and low-dose 1 024×1 024 matrix images were satisfactory and showed no significant difference. The morphology, size and relative position of malleus, incus, stapes, cochlea, and labyrinth, as well as the location of the ossicular chain in the cranium were all clearly displayed.

CONCLUSION

Low-dose temporal bone CT with the matrix size of 1 024×1 024 can be used to effectively reduce the radiation dose and significantly improve the spatial resolution and the visualization of the temporal bone anatomical structures compared with the normal-dose temporal bone CT with a matrix size of 512×512.

[A Randomized Controlled Study of Intravesical Instillation Therapy of Bacillus Calmette-Guérin vs. Epirubicinin Treating Non-muscular Invasive Bladder Cancer]

OBJECTIVE

To explore the best treatment plan of intravesical instillation for patients with non-muscular invasive bladder cancer (NMIBC), to explore recurrence-related clinicopathological factors after intravesical instillation, and to evaluate the value of the prognosis and prediction models currently used for NMIBC patients.

METHODS

Starting from 2016, patients who underwent transurethral resection of bladder tumor (TURBT) in our hospital and who received post-surgery diagnosis of having intermediate or high risks for NMIBC were enrolled in the study. They were randomly assigned to different group sat a ratio of 2∶2∶1 for receiving intravesical instillation therapy of Bacillus Calmette-Guérin (BCG) for 19 times, BCG for 15 times, and epirubicin (EPI) for 18 times. The clinicopathological data of the patients were recorded before, during and after instillation therapy, and survival curves were drawn to evaluate the effects of the three regimens, using recurrence-free survival as the endpoint. Clinicopathological data were analyzed to study the associations between various factors and post-instillation recurrence. The consistency index (c-index) was used to evaluate the predictive accuracy of the scoring model of the Spanish Urological Club for Oncological Treatment (CUETO) and the risk tables of European Organization for Research and Treatment of Cancer (EORTC).

RESULTS

A total of 93 NMIBC patients (35 in the 19-time BCG group, 37 in the 15-time BCG group, and 21 in the EPI group) were included, with a median follow-up time of 33.46 months. Twenty-two patients experienced tumor recurrence and eight, tumor progression. The survival curve showed that the BCG group had better recurrence-free survival than the EPI group ( P=0.002), while the difference in recurrence-free survival between 19-time BCG and 15-time BCG groups was not statistically significant. Higher general complication rate was seen in the BCG groups compared with the EPI group (84.7% vs. 61.9%, P=0.022), but there was no grade 3-5 adverse events in any group. The c-index of CUETO scoring model and EORTC risk tables was higher than that of the prediction based solely on T stage, nuclear grade, or EAU risk stratification. In addition, the c-index in the BCG group was higher than that in the whole cohort.

CONCLUSION

Among the subjects of this study, the recurrence rate of bladder cancer in the intravesical BCG instillation groups was lower than that of the epirubicin group. EORTC risk tables and CUETO scoring model exhibited higher predictive accuracies in BCG-treated patients than its performance for the whole NMIBC cohort.