High-throughput screening identifies stevioside as a potent agent to induce apoptosis in bladder cancer cells.

BACKGROUND: Bladder cancer (BC) is a global health issue that lacks effective treatment strategies. Growing evidence suggests that various natural products possess anti-tumour effects. This study aims to identify a novel agent that can be used in the treatment of BC. METHODS: High-throughput screening was conducted to search for potential anti-BC natural agents. Cell viabilities were measured by the CCK-8 assay. Cell death, cellular reactive oxygen species (ROS), and mitochondrial outer membrane potential (MOMP) were measured by flow cytometry. RNA sequencing was conducted to identify the affected signalling pathways. Western blots were used to measure the change of proteins. Xenografts models were used to assess the anti-tumour effects in vivo. RESULTS: Through high-throughput screening, we identified stevioside, a diterpenoid glycoside isolated from Stevia rebaudiana, which selectively inhibited the viability of BC cells and induced their intrinsic apoptosis sparing normal cells. Stevioside also induced mitochondrial stress in BC cells, and activated Bax by downregulating Mcl-1 and upregulating Noxa. RNA sequencing revealed that stevioside treatment caused activation of GSK-3ß and endoplasmic reticulum (ER) stress signalling pathways. Activation of GSK-3ß induced upregulation of FBXW7, which effectuated the downregulation of Mcl-1. In addition, activation of GSK-3ß triggered ER stress, leading to the upregulation of Noxa. Further investigations revealed that the accumulation of ROS was responsible for the activation of the GSK-3ß signalling pathway in BC cells. Moreover, we also found that stevioside inhibited the growth of BC cells in vivo. CONCLUSIONS: Collectively, our data suggest that stevioside can be a potential agent for the treatment of BC.

Evaluation of a Dual PI3K/mTOR Inhibitor PF-04691502 against Bladder Cancer Cells.

Targeting the phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signalling pathway is a promising strategy for the treatment of various cancers, including bladder cancer (BC). PF-04691502 is a relatively novel dual PI3K/mTOR inhibitor that exerts inhibitory effects against various cancer cells. However, the effects of PF-04691502 in BC cells have not been clarified thus far. This study aimed to evaluate the antitumour effects of PF-04691502 and the mechanisms underlying these antitumour effects in BC cells. The effects of PF-04691502 on the viabilities of BC cells were examined using the cell counting kit 8 (CCK-8) assay. Cell migration and invasion were measured using the wound healing assay and transwell assay, respectively. Cellular apoptosis was determined using flow cytometry. The change in the cellular protein levels was measured using western blotting. siRNA was used to study the role of PTEN in the antitumour effects of PF-04691502. PF-04691502 inhibited the proliferation, migration, and invasion of BC cells. Additionally, PF-04691502 induced apoptosis of BC cells via the intrinsic pathway. PF-04691502 inhibited the expression of Mcl-1 and the PI3K/Akt/mTOR pathway in BC cells. In addition, PF-04691502 increased the apoptosis induced by various chemotherapeutic agents in BC cells. Taken together, PF-04691502 could be used alone or in combination with other chemotherapeutic agents in the treatment of BC.

LncRNA BACE1-AS promotes the progression of osteosarcoma through miR-762/SOX7 axis.

BACKGROUND: Osteosarcoma (OS) is a rare malignant primary tumor of mesenchymal origin affecting bone that occurs in adolescents and children. LncRNAs are important regulators of tumorigenesis and development. This study aimed to explore the role and molecular basis of LncRNA BACE1-AS (BACE1 antisense RNA) in OS. METHODS AND RESULTS: Through the analysis of differential expressed lncRNAs in OS tissues by GEO database, LncRNA BACE1-AS display a remarkably lower expression. This found can also be observed in both OS tissues and cell lines by qRT-PCR. Furthermore, using Cell counting kit-8 (CCK-8), transwell, wound healing and westernblot assays, overexpression LncRNA BACE1-AS remarkably reduce cell proliferation, migration and invasion abilities in OS. In addition, LncRNA BACE1-AS is validated as a sponge of miR-762 through the prediction of lncRNASNP. Further, luciferase reporter and RIP assays are conducted to confirm the binding sites between LncRNA BACE1-AS and miR-762. SRY-box transcription factor 7 (SOX7) target to miR-762 and regulated by LncRNA BACE1-AS. Moreover, inhibition of miR-762 attenuate the role of sh-LncRNA BACE1-AS in OS cells, at meanwhile reduce the expression of SOX7. CONCLUSION: In this study, LncRNA BACE1-AS regulates proliferation, migration and invasion of osteosarcoma cells by miR-762/SOX7 axis, implying that LncRNA BACE1-AS is a potential target for osteosarcoma therapy.

Long non-coding RNA UCA1 contributes to the progression of prostate cancer and regulates proliferation through KLF4-KRT6/13 signaling pathway.

Long non-coding RNAs (lncRNAs) UCA1 have been shown to paly an important regulatory roles in cancer biology, and UCA1 dysfunction is related to TNM stage, metastasis and postoperative survival in several cancers. However, the biological role and clinical significance of UCA1 in the carcinogenesis of prostate cancer (PC) remain largely unclear. Herein, we found that UCA1 was abnormally upregulated in tumor tissues from PC patients, and patients with high UCA1 levels had a significantly poorer prognosis. Intriguingly, the mRNA and protein levels of KLF4 were significantly increased in tumor tissues, which was highly correlated to UCA1 levels. Moreover, UCA1 depletion inhibited the growth and induced apoptosis in PC3 and LNCaP cell lines. In addition, UCA1 loss-of-function could decrease KLF4 expression, subsequently, the downregulation of KRT6 and KRT13. Taken together, our study indicated that UCA1 had a crucial role in the tumorigenesis of PC. Moreover, UCA1 loss-of-function inhibited cell proliferation and induced cell apoptosis, at least partially, through inactivation KLF4-KRT6/13 cascade.