Epidemiological studies show obvious gender differences in the incidence and the prognosis of bladder cancer (BCa). Estrogen receptor alpha (ERα) was recently shown to play a protective role in BCa. However, the mechanisms by which ERα mediates BCa progression need to be further elucidated. In the present study, we explored the mechanisms by which ERα inhibits BCa invasion by modulating circRNA levels. ERα suppressed BCa invasion by decreasing circ_0023642 expression. Chromatin immunoprecipitation (ChIP) and luciferase assays revealed that ERα reduced circ_0023642 expression by regulating the expression of its host gene, UVRAG, at the transcriptional level. ERα decreased circ_0023642 levels and subsequently increased miR-490-5p expression, resulting in decreased EGFR expression to suppress BCa cell invasion. Circ_0023642 was demonstrated to directly bind to miR-490-5p. Notably, miR-490-5p regulated EGFR expression by binding to the miR-490-5p-binding site located in the 3′-untranslated region (UTR) of the EGFR mRNA. Preclinical studies using an in vivo mouse model also confirmed that this ERα/circ_0023642/miR-490-5p/EGFR signaling pathway suppressed BCa progression. Altogether, this newly identified pathway may serve as the basis for developing novel therapeutic strategies to treat BCa.

Early evidences have showed that mast cells could infiltrate into benign prostatic hyperplasia (BPH) tissues, but the exact role of mast cells in BPH development remains unclear. In this study, we identified more mast cells existing in human BPH tissues compared with that in the normal prostate. In the in vitro co-culture system, BPH-1 prostate cells promoted activation and migration of mast cells, and mast cells conversely stimulated BPH-1 cells proliferation significantly. Molecular analysis demonstrated that mast cell-derived interleukin 6 (IL-6) could activate STAT3/Cyclin D1 signals in BPH-1 cells. Blocking IL-6 or STAT3 partially reverse the capacity of mast cells to enhance BPH-1 cell proliferation. Our findings suggest that infiltrating mast cells in BPH tissues could promote BPH development via IL-6/STAT3/Cyclin D1 signals. Therefore, targeting infiltrating mast cells may improve the therapeutic effect of BPH.

PurposePB is one of the most severe complications of late stage prostate cancer and negatively impacts patient quality of life. A major challenge for the treatment of cancer bone metastasis is the management of efficient drug delivery to metastatic bone lesion. We aimed to explore the use of aptamers as promising tools to develop a targeted drug delivery system for PBs.Materials and methodsIn vivo SELEX was applied to identify bone targeting aptamer in a mouse model with PBs.ResultsThe aptamer (designated as “PB”) with the highest bone targeting frequency in mice bearing PC3 PB was selected for further analysis. The PB aptamer specifically targeted modulated endothelial cells in response to cancer cells in the bones of mice bearing PC3 PBs. The targeting efficiency of the PB aptamer conjugated to gold particles was verified in vivo.ConclusionThis investigation highlights the promise of in vivo SELEX for the discovery of bone targeting aptamers for use in drug delivery.

Background A high prevalence of osteoblastic bone metastases is characteristic of prostate cancer. Prostate‐specific antigen (PSA) is a serine protease uniquely produced by prostate cancer cells and is an important serological marker for prostate cancer. However, whether PSA modulates the osteogenic process remains largely unknown. In this study, we explored the effect of PSA on modulating the osteoblastic differentiation of mesenchymal stem cells (MSCs). In this study, we used flow cytometry, CCK‐8 assay, Alizarin red S (ARS) staining and quantification, alkaline phosphatase (ALP) activity and staining, Western blotting, and quantitative real‐time PCR (qRT‐PCR) to explore the effect of PSA on osteogenic differentiation of MSCs. Results We first demonstrated that although PSA did not affect the proliferation, morphology, or phenotype of MSCs, it significantly promoted the osteogenic differentiation of MSCs in a concentration‐dependent manner. Furthermore, we demonstrated that PSA promoted the osteogenic differentiation of MSCs by elevating the expression of Cadherin 11 in MSCs and, thus, activating the Akt signaling pathway. Conclusions In conclusion, we demonstrated that PSA could promote the osteogenesis of MSCs through Akt signaling pathway activation by elevating the expression of cadherin‐11 in MSCs. These findings imply a possible role of PSA in osteoblastic bone metastases in prostate cancer.

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