PurposeCisplatin-based chemotherapy is the first line treatment for several cancers including bladder cancer (BC). Autophagy induction has been implied to contribute to cisplatin resistance in ovarian cancer; and a high basal level of autophagy has been demonstrated in human bladder tumors. Therefore, it is reasonable to speculate that autophagy may account for the failure of cisplatin single treatment in BC. This study investigated whether cisplatin induces autophagy and the mechanism involved using human BC cell lines.Materials and methodsHuman BC cells (5637 and T24) were used in this study. Cell viability was detected using water soluble tetrazolium-8 reagents. Autophagy induction was detected by monitoring the levels of light chain 3 (LC3)-II and p62 by Western blot, LC3-positive puncta formation by immunofluorescence, and direct observation of the autophagolysosome (AL) formation by transmission electron microscopy. Inhibitors including bafilomycin A1 (Baf A1), chloroquine (CQ), and shRNA-based lentivirus against autophagy-related genes (ATG7 and ATG12) were utilized. Apoptosis level was detected by caspase 3/7 activity and DNA fragmentation.ResultsCisplatin decreased cell viability and induced apoptosis of 5637 and T24 cells in a dose-and time-dependent manner. The increased LC3-II accumulation, p62 clearance, the number of LC3-positive puncta, and ALs in cisplatin-treated cells suggested that cisplatin indeed induces autophagy. Inhibition of cisplatin-induced autophagy using Baf A1, CQ, or ATG7/ATG12 shRNAs significantly enhanced cytotoxicity of cisplatin toward BC cells. These results indicated that cisplatin induced protective autophagy which may contribute to the development of cisplatin resistance and resulted in treatment failure. Mechanistically, upregulation of beclin-1 (BECN1) was detected in cisplatin-treated cells, and knockdown of BECN1 using shRNA attenuated cisplatin-induced autophagy and subsequently enhanced cisplatin-induced apoptosis.ConclusionCollectively, the study results indicated that cisplatin-induced autophagy is mediated by BECN1 in BC cells. Therefore, combinative treatment using cisplatin and autophagy inhibitors could potentially overcome cisplatin resistance related to autophagy induction.
Benzyl isothiocyanate (BITC) is a dietary chemopreventive agent that inhibits the growth of various human cancer cells by causing apoptotic cell death. In this study, we demonstrate that BITC not only induces apoptosis but also induces autophagy in human hormone-sensitive (Rv1) and -refractory (PC3) prostate cancer cells. In BITC-treated cells, the induction of autophagy was detected by monitoring the processing of an autophagy marker protein, microtubule-associated protein 1 light chain 3 (LC3), the aggregation of LC3 into granular structures and the formation of acidic organelles. Inhibition of autophagy using 3-methyladenine increased BITC-induced apoptosis, whereas the administration of caspase inhibitor suppressed BITC-induced cell death. Our data also showed that BITC inhibits mammalian target of rapamycin (mTOR) kinase activity in a dose-dependent manner. The expression of phospho-mTOR (Ser2481), an indicator of mTOR intrinsic catalytic activity, and phospho-UNC-51-like kinase 1 (Ser757), a direct substrate of mTOR, were decreased in BITC-treated cells. However, the increased expression of phospho-mTOR (Ser2448), phospho-AKT (Ser473) and antiapoptotic Bcl-2 were detected only in PC3 cells at later stages of BITC treatment. Collectively, our results show that BITC induces a protective autophagy response in Rv1 and PC3 cells through inhibition of the mTOR signaling pathway. Activation of the AKT survival pathway was only observed in PC3 cells, representing a resistance mechanism of advanced prostate cancer upon BITC treatment. These findings could potentially contribute to the beneficial effect of BITC in prostate cancer treatments.
Introduction There are currently no studies in the Asia-Pacific region using the erection hardness score (EHS) and Quality of Erection Questionnaire (QEQ) to assess erectile dysfunction (ED). Aims To provide up-to-date data on the prevalence of ED in Taiwanese men and to validate the EHS and QEQ in this population. Methods A representative sample of 1,060 men aged ≥30 years completed a telephone interview. ED status was confirmed via direct questioning and using the abridged five-item version of the 15-item International Index of Erectile Function (IIEF-5). Responses regarding EHS, QEQ, marital and sexual satisfaction, and attitude to treatment were also recorded. Main Outcome Measures IIEF, EHS, and QEQ. Results The prevalence of ED, as defined by IIEF-5, was 27% among all respondents and 29% among those aged ≥40 years. Although, the prevalence of ED increased with age, men of all ages tended to underestimate their erectile problems. Among men who indicated that they did not have ED, 25% were found to have mild to moderate ED according to the IIEF-5 assessment. An EHS ≤3, indicating the presence of ED, was reported in 26% of men. The EHS was consistent with the QEQ: When the EHS was 4, the satisfaction of each domain of QEQ ranged from 85% to 90%. The QEQ score correlated well with the IIEF-5 score and significantly affected both sexual and marital satisfaction (P <0.005). Conclusions These data indicate that EHS is a simple, practical tool for clinical use. QEQ scores appear to be independently associated with sexual and marital satisfaction, and may be of value in the assessment and monitoring of ED patients. While ED is a common health problem in Taiwan and the prevalence of ED increases with age, affected men lack awareness regarding the presence of erectile problems and the importance of initiating timely and effective treatment.
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