Androgens modify therapeutic response to cabazitaxel in models of advanced prostate cancer

Cancer on motors: How kinesins drive prostate cancer progression?

Prostate cancer causes numerous male deaths annually. Although great progress has been made in the diagnosis and treatment of prostate cancer during the past several decades, much about this disease remains unknown, especially its pathobiology. The kinesin superfamily is a pivotal group of motor proteins, that contains a microtubule-based motor domain and features an adenosine triphosphatase activity and motility characteristics. Large-scale sequencing analyses based on clinical samples and animal models have shown that several members of the kinesin family are dysregulated in prostate cancer. Abnormal expression of kinesins could be linked to uncontrolled cell growth, inhibited apoptosis and increased metastasis ability. Additionally, kinesins may be implicated in chemotherapy resistance and escape immunologic cytotoxicity, which creates a barrier to cancer treatment. Here we cover the recent advances in understanding how kinesins may drive prostate cancer progression and how targeting their function may be a therapeutic strategy. A better understanding of kinesins in prostate cancer tumorigenesis may be pivotal for improving disease outcomes in prostate cancer patients.

A Clinically-Achievable Injectable and Sprayable in Situ Lyotropic Liquid Crystalline Platform in Treating Hormone-Sensitive and Castration-Resistant Prostate Cancer

When it comes to long-acting injections, lyotropic liquid crystals (LLCs) are considered as an effective and powerful drug delivery technology due to their low manufacturing and injection difficulty, consistent releasing behaviors with low burst, as well as broadly applicable drug loading capacity. However, monoolein and phytantriol, as two widely used LLC-forming materials, may give rise to tissue cytotoxicity and undesired immunological responses, which may hinder the wide application of this technology. In this study, we opted for two ingredients, phosphatidylcholine and α-tocopherol, as carriers on account of their nature-obtainable and biocompatible qualities. By changing the ratios between them, we conducted research on crystalline types, nanosized structures, viscoelastic differences, characteristics of releasing behaviors, and in vivo safety. To fully exploit this in situ LLC platform with both injectability and sprayability, we focused on the treatment of both hormone-sensitive (HSPC) and castration-resistant prostate cancer (CRPC). For HSPC, we found that spraying leuprolide and a cabazitaxel-loaded LLC platform on the tumor bed after resection greatly reduced tumor metastatic rate and prolonged the survival time. Besides, for CRPC, our results demonstrated that although leuprolide (a kind of drug for castration) alone could hardly limit the progression of CRPC with low MHC-I expression, its combination with cabazitaxel in our LLC platform achieved a significantly better tumor-inhibiting and anti-recurrent efficacy than single cabazitaxel-loaded LLC platform, owing to enhanced CD4⁺ T cell infiltration in tumors and immune-potentiating cytokines. In conclusion, our dual-functional and clinically achievable strategy might provide a treating solution toward both HSPC and CRPC.

Impact of Circadian Rhythms on the Development and Clinical Management of Genitourinary Cancers

The circadian system is an innate clock mechanism that governs biological processes on a near 24-hour cycle. Circadian rhythm disruption (i.e., misalignment of circadian rhythms), which results from the lack of synchrony between the master circadian clock located in the suprachiasmatic nuclei (SCN) and the environment (i.e., exposure to day light) or the master clock and the peripheral clocks, has been associated with increased risk of and unfavorable cancer outcomes. Growing evidence supports the link between circadian disruption and increased prevalence and mortality of genitourinary cancers (GU) including prostate, bladder, and renal cancer. The circadian system also plays an essential role on the timely implementation of chronopharmacological treatments, such as melatonin and chronotherapy, to reduce tumor progression, improve therapeutic response and reduce negative therapy side effects. The potential benefits of the manipulating circadian rhythms in the clinical setting of GU cancer detection and treatment remain to be exploited. In this review, we discuss the current evidence on the influence of circadian rhythms on (disease) cancer development and hope to elucidate the unmet clinical need of defining the extensive involvement of the circadian system in predicting risk for GU cancer development and alleviating the burden of implementing anti-cancer therapies.

Functional Implication of Exosomal miR-217 and miR-23b-3p in the Progression of Prostate Cancer

Objective

The microRNA expression profile of plasma exosomes in prostate cancer (PCa) is of critical importance in the disease exploration. This study aimed to explore the clinical application of exosomal miRNAs as biomarkers for PCa.

Methods

Exosome-like vesicles of PCa patients and healthy controls were purified by differential centrifugation. The purified vesicles within the ranges of 50 and 100 nm were classified as exosomes according to the results of transmission electron microscopy and Western blot. Both, in vitro and in vivo, validations were performed by small RNA sequencing, CCK8, RT-qPCR, flow cytometry, Western blot, transwell and immunofluorescent staining assays.

Results

High-throughput sequencing identified that 94 miRNAs were differentially expressed in PCa patients in comparison with healthy controls (P<0.01; fold change ≥2). Among them, 64 miRNAs were upregulated, and 30 miRNAs were downregulated. In comparison to the healthy controls, the expression levels of miR-217 were significantly upregulated, while miR-23b-3p were significantly downregulated in the exosomes and serum collected from PCa patients. Both, in vitro and in vivo, studies revealed that exosomes secreted by PCa cells with up-regulated miR-217 levels promoted cell proliferation and invasion; meanwhile, the exosomes with up-regulated miR-23b-3p levels inhibited cell proliferation and invasion. The epithelial–mesenchymal transition process may have been involved in the above-mentioned regulation.

Conclusion

This study identified the dysregulated expression of exosomal miRNAs in PCa patients, including miR-217 and miR-23b-3p, by validating their function on proliferation and invasion in PCa cells. This regulation may have been affected by the epithelial–mesenchymal transition process, suggesting that they can be used as potential targets in the diagnosis and treatment of PCa.