Humanized bone facilitates prostate cancer metastasis and recapitulates therapeutic effects of zoledronic acid in vivo

Biomaterial-assisted therapeutic cell production and modification in vivo

Hematopoietic stem cell transplantation remains the preferred treatment for a variety of hematopoietic function disorders. To address the issue of limited numbers of hematopoietic stem/progenitor cells (HSPCs), significant progress has been made in the technology for ex vivo expansion of HSPCs. In addition, biomaterial-assisted in vivo production technology for therapeutic cells, including HSPCs, is gradually gaining attention. With the aid of specifically functional biomaterials, researchers can construct bone-like tissues exhibiting typical bone marrow-like structures (termed in vivo osteo-organoids in this article) for the production of therapeutic cells. These in vivo osteo-organoids mimic the native bone marrow niche and provide a microenvironment conducive to the expansion and differentiation of HSPCs. In this perspective article, we systematically summarize the history of in vivo osteo-organoids as a model for studying hematopoiesis and cancer metastasis and propose the challenges faced by the in vivo osteo-organoid production platform for therapeutic cells in terms of clinical translation. Ultimately, we hope to achieve functional customization of in vivo osteo-organoid-derived cells through continuously developed material design methods, so as to meet the treatment needs of different types of diseases and bring hope for life to more people.

Unraveling the Role of EV-Derived miR-150-5p in Prostate Cancer Metastasis and Its Association with High-Grade Gleason Scores: Implications for Diagnosis

Metastasis remains the leading cause of mortality in prostate cancer patients. The presence of tumor cells in lymph nodes is an established prognostic indicator for several cancer types, such as melanoma, breast, oral, pancreatic, and cervical cancers. Emerging evidence highlights the role of microRNAs enclosed within extracellular vesicles as facilitators of molecular communication between tumors and metastatic sites in the lymph nodes. This study aims to investigate the potential diagnostic utility of EV-derived microRNAs in liquid biopsies for prostate cancer. By employing microarrays on paraffin-embedded samples, we characterized the microRNA expression profiles in metastatic lymph nodes, non-metastatic lymph nodes, and primary tumor tissues of prostate cancer. Differential expression of microRNAs was observed in metastatic lymph nodes compared to prostate tumors and non-metastatic lymph node tissues. Three microRNAs (miR-140-3p, miR-150-5p, and miR-23b-3p) were identified as differentially expressed between tissue and plasma samples. Furthermore, we evaluated the expression of these microRNAs in exosomes derived from prostate cancer cells and plasma samples. Intriguingly, high Gleason score samples exhibited the lowest expression of miR-150-5p compared to control samples. Pathway analysis suggested a potential regulatory role for miR-150-5p in the Wnt pathway and bone metastasis. Our findings suggest EV-derived miR-150-5p as a promising diagnostic marker for identifying patients with high-grade Gleason scores and detecting metastasis at an early stage.

RGD-directed 24 nm micellar docetaxel enables elevated tumor-liver ratio, deep tumor penetration and potent suppression of solid tumors

Nanomedicines while showing a great potential in improving the performance of chemotherapeutics like docetaxel (DTX) are distressed by a high liver deposition and poor tumor penetration, which might not only cause liver toxicity but also moderate therapeutic effect. Herein, we report that cRGD-directed 24 nm disulfide-crosslinked micellar docetaxel (cRGD-MDTX) presents low liver accumulation, high tumor uptake, and deep tumor penetration, leading to the potent suppression of different solid tumors. cRGD-MDTX was optimized with a cRGD density of 4% and DTX loading of 10 wt%. Interestingly, cRGD-MDTX enabled an extraordinary tumor-liver ratio of 2.8/1 with a DTX uptake of 8.3 %ID/g in αvβ3 over-expressing PC3 prostate tumor. The therapeutic studies demonstrated striking antitumor effects of cRGD-MDTX toward PC3 prostate tumor, prostate cancer patient-derived xenografts (PDX), orthotopic A549-Luc lung cancer and orthotopic SKOV3-Luc ovarian tumor models, in which tumor growth was effectually inhibited and 6-8 times better improvement of median survival time over free DTX was observed. This small disulfide-crosslinked micellar drug capable of relegating liver deposition opens a new avenue to nanomedicines for targeted therapy.

Animal models of cancer metastasis to the bone

Cancer metastasis is a major cause of mortality from several tumors, including those of the breast, prostate, and the thyroid gland. Since bone tissue is one of the most common sites of metastasis, the treatment of bone metastases is crucial for the cure of cancer. Hence, disease models must be developed to understand the process of bone metastasis in order to devise therapies for it. Several translational models of different bone metastatic tumors have been developed, including animal models, cell line injection models, bone implant models, and patient-derived xenograft models. However, a compendium on different bone metastatic cancers is currently not available. Here, we have compiled several animal models derived from current experiments on bone metastasis, mostly involving breast and prostate cancer, to improve the development of preclinical models and promote the treatment of bone metastasis.

Advancing Treatment of Bone Metastases through Novel Translational Approaches Targeting the Bone Microenvironment

Bone metastases represent a lethal condition that frequently occurs in solid tumors such as prostate, breast, lung, and renal cell carcinomas, and increase the risk of skeletal-related events (SREs) including pain, pathologic fractures, and spinal cord compression. This unique metastatic niche consists of a multicellular complex that cancer cells co-opt to engender bone remodeling, immune suppression, and stromal-mediated therapeutic resistance. This review comprehensively discusses clinical challenges of bone metastases, novel preclinical models of the bone and bone marrow microenviroment, and crucial signaling pathways active in bone homeostasis and metastatic niche. These studies establish the context to summarize the current state of investigational agents targeting BM, and approaches to improve BM-targeting therapies. Finally, we discuss opportunities to advance research in bone and bone marrow microenvironments by increasing complexity of humanized preclinical models and fostering interdisciplinary collaborations to translational research in this challenging metastatic niche.

Engineering a 3D bone marrow adipose composite tissue loading model suitable for studying mechanobiological questions

Tissue engineering strategies are widely used to model and study the bone marrow microenvironment in healthy and pathological conditions. Yet, while bone function highly depends on mechanical stimulation, the effects of biomechanical stimuli on the bone marrow niche, specifically on bone marrow adipose tissue (BMAT) is poorly understood due to a lack of representative in vitro loading models. Here, we engineered a BMAT analog made of a GelMA (gelatin methacryloyl) hydrogel/medical-grade polycaprolactone (mPCL) scaffold composite to structurally and biologically mimic key aspects of the bone marrow microenvironment, and exploited an innovative bioreactor to study the effects of mechanical loading. Highly reproducible BMAT analogs facilitated the successful adipogenesis of human mesenchymal bone marrow stem cells. Upon long-term intermittent stimulation (1 Hz, 2 h/day, 3 days/week, 3 weeks) in the novel bioreactor, cellular proliferation and lipid accumulation were similar to unloaded controls, yet there was a significant reduction in the secretion of adipokines including leptin and adiponectin, in line with clinical evidence of reduced adipokine expression following exercise/activity. Ultimately, this innovative loading platform combined with reproducibly engineered BMAT analogs provide opportunities to study marrow physiology in greater complexity as it accounts for the dynamic mechanical microenvironment context.

A humanized orthotopic tumor microenvironment alters the bone metastatic tropism of prostate cancer cells

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men, and bone is the most frequent site of metastasis. The tumor microenvironment (TME) impacts tumor growth and metastasis, yet the role of the TME in PCa metastasis to bone is not fully understood. We used a tissue-engineered xenograft approach in NOD-scid IL2Rγ^null (NSG) mice to incorporate two levels of humanization; the primary tumor and TME, and the secondary metastatic bone organ. Bioluminescent imaging, histology, and immunohistochemistry were used to study metastasis of human PC-3 and LNCaP PCa cells from the prostate to tissue-engineered bone. Here we show pre-seeding scaffolds with human osteoblasts increases the human cellular and extracellular matrix content of bone constructs, compared to unseeded scaffolds. The humanized prostate TME showed a trend to decrease metastasis of PC-3 PCa cells to the tissue-engineered bone, but did not affect the metastatic potential of PCa cells to the endogenous murine bones or organs. On the other hand, the humanized TME enhanced LNCaP tumor growth and metastasis to humanized and murine bone. Together this demonstrates the importance of the TME in PCa bone tropism, although further investigations are needed to delineate specific roles of the TME components in this context.

Clinical efficiency of epigenetic drugs therapy in bone malignancies

A great interest in the scientific community is focused on the improvement of the cure rate in patients with bone malignancies that have a poor response to the first line of therapies. Novel treatments currently include epigenetic compounds or molecules targeting epigenetic-sensitive pathways. Here, we offer an exhaustive review of such agents in these clinical settings. Carefully designed preclinical studies selected several epigenetic drugs, including inhibitors of DNA methyltransferase (DNMTIs), such as Decitabine, histone deacetylase classes I-II (HDACIs), as Entinostat, Belinostat, lysine-specific histone demethylase (LSD1), as INCB059872 or FT-2102 (Olutasidenib), inhibitors of isocitrate dehydrogenases, and enhancer of zeste homolog 2 (EZH2), such as EPZ6438 (Tazemetostat) To enhance the therapeutic effect, the prevalent approach in phase II trial is the association of these epigenetic drug inhibitors, with targeted therapy or immune checkpoint blockade. Optimization of drug dosing and regimens of Phase II trials may improve the clinical efficiency of such novel therapeutic approaches against these devastating cancers.

Recent Advances in Nanomedicine for the Diagnosis and Treatment of Prostate Cancer Bone Metastasis

Patients with advanced prostate cancer can develop painful and debilitating bone metastases. Currently available interventions for prostate cancer bone metastases, including chemotherapy, bisphosphonates, and radiopharmaceuticals, are only palliative. They can relieve pain, reduce complications (e.g., bone fractures), and improve quality of life, but they do not significantly improve survival times. Therefore, additional strategies to enhance the diagnosis and treatment of prostate cancer bone metastases are needed. Nanotechnology is a versatile platform that has been used to increase the specificity and therapeutic efficacy of various treatments for prostate cancer bone metastases. In this review, we summarize preclinical research that utilizes nanotechnology to develop novel diagnostic imaging tools, translational models, and therapies to combat prostate cancer bone metastases.

Exploitation of the chick embryo chorioallantoic membrane (CAM) as a platform for anti-metastatic drug testing

The establishment of clinically relevant models for tumor metastasis and drug testing is a major challenge in cancer research. Here we report a physiologically relevant assay enabling quantitative analysis of metastatic capacity of tumor cells following implantation into the chorioallantoic membrane (CAM). Engraftment of as few as 10³ non-small cell lung cancer (NSCLC) and prostate cancer (PCa) cell lines was sufficient for both primary tumor and metastasis formation. Standard 2D-imaging as well as 3D optical tomography imaging were used for the detection of fluorescent metastatic foci in the chick embryo. H2228- and H1975-initiated metastases were confirmed by genomic analysis. We quantified the inhibitory effect of docetaxel on LNCaP, and that of cisplatin on A549- and H1299-initiated metastatic growths. The CAM assay also mimicked the sensitivity of ALK-rearranged H2228 and EGFR-mutated H1975 NSCLC cells to tyrosine kinase inhibitors crizotinib and gefitinib respectively, as well as sensitivity of LNCaP cells to androgen-dependent enzalutamide therapy. The assay was suggested to reconstitute the bone metastatic tropism of PCa cells. We show that the CAM chick embryo model may be a powerful preclinical platform for testing and targeting of the metastatic capacity of cancer cells.

Human and mouse bones physiologically integrate in a humanized mouse model while maintaining species-specific ultrastructure

Humanized mouse models are increasingly studied to recapitulate human-like bone physiology. While human and mouse bone architectures differ in multiple scales, the extent to which chimeric human-mouse bone physiologically interacts and structurally integrates remains unknown. Here, we identify that humanized bone is formed by a mosaic of human and mouse collagen, structurally integrated within the same bone organ, as shown by immunohistochemistry. Combining this with materials science techniques, we investigate the extracellular matrix of specific human and mouse collagen regions. We show that human-like osteocyte lacunar-canalicular network is retained within human collagen regions and is distinct to that of mouse tissue. This multiscale analysis shows that human and mouse tissues physiologically integrate into a single, functional bone tissue while maintaining their species-specific ultrastructural differences. These results offer an original method to validate and advance tissue-engineered human-like bone in chimeric animal models, which grow to be eloquent tools in biomedical research.

Engineering a Humanised Niche to Support Human Haematopoiesis in Mice: Novel Opportunities in Modelling Cancer

Despite the bone marrow microenvironment being widely recognised as a key player in cancer research, the current animal models that represent a human haematopoietic system lack the contribution of the humanised marrow microenvironment. Here we describe a murine model that relies on the combination of an orthotopic humanised tissue-engineered bone construct (ohTEBC) with patient-specific bone marrow (BM) cells to create a humanised bone marrow (hBM) niche capable of supporting the engraftment of human haematopoietic cells. Results showed that this model supports the engraftment of human CD34⁺ cells from a healthy BM with human haematopoietic cells migrating into the mouse BM, human BM compartment, spleen and peripheral blood. We compared these results with the engraftment capacity of human CD34⁺ cells obtained from patients with multiple myeloma (MM). We demonstrated that CD34⁺ cells derived from a diseased BM had a reduced engraftment potential compared to healthy patients and that a higher cell dose is required to achieve engraftment of human haematopoietic cells in peripheral blood. Finally, we observed that hematopoietic cells obtained from the mobilised peripheral blood of patients yields a higher number of CD34⁺, overcoming this problem. In conclusion, this humanised mouse model has potential as a unique and patient-specific pre-clinical platform for the study of tumour–microenvironment interactions, including human bone and haematopoietic cells, and could, in the future, serve as a drug testing platform.

Prognosis of prostate cancer and bone metastasis pattern of patients: a SEER-based study and a local hospital based study from China

Prostate cancer (PCa) is the leading cause of cancer-related death among men worldwide. Knowledge of the prognostic factors of PCa and the bone metastasis pattern of patients would be helpful for patients and doctors. The data of 177,255 patients with prostate cancer diagnosed between 2010 and 2013 with at least five years of follow-up were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox regression analysis was used to determine the predictive value of patients’ characteristics for survival after adjusting for other variates. Multivariate logistic regression analysis was used to evaluate the odds ratio of bone metastasis in PCa patients. The predictive value of age, race, marital status, and tumor characteristics were compared. The survival of patients with different socioeconomic statuses and bone metastasis statuses was compared by Kaplan–Meier analysis. A total of 1,335 patients with prostate cancer diagnosed between 2009 and 2015 were enrolled from the Second Affiliated Hospital of Zhejiang University School of Medicine. The survival of patients with different prostate-specific antigen (PSA) levels, Gleason scores, marital statuses and bone metastasis statuses was compared by Kaplan-Meier analysis. In SEER database, 96.74% of patients were 50 years of age or older. Multivariate Cox analysis revealed that for PCa patients, age at presentation, older age, single marital status, lower socioeconomic status, higher PSA level, T1 and N0 stage, and bone metastasis were independent risk factors for increased mortality. Multivariate logistic regression analysis revealed that patients who were married, were living in urban areas, had lower PSA levels, underwent surgery, and radiation had lower OR factors for bone metastasis. Asian or Pacific Islander, better socioeconomic status, lived in urban areas, married marital status, lower PSA levels and lower Gleason scores were better prognostic factors in PCa. Additionally, patients with single or divorced marital status, who were living in rural places had higher PSA levels, and T1 and N0 stages have a high OR for bone metastasis.

Correction: Humanized bone facilitates prostate cancer metastasis and recapitulates therapeutic effects of Zoledronic acid in vivo

[This corrects the article DOI: 10.1038/s41413-019-0072-9.].

Design and Fabrication of Three-Dimensional Printed Scaffolds for Cancer Precision Medicine

Three-dimensional (3D)-engineered scaffolds have been widely investigated as drug delivery systems (DDS) or cancer models with the aim to develop effective cancer therapies. The in vitro and in vivo models developed via 3D printing (3DP) and tissue engineering concepts have significantly contributed to our understanding of cell-cell and cell-extracellular matrix interactions in the cancer microenvironment. Moreover, 3D tumor models were used to study the therapeutic efficiency of anticancer drugs. The present study aims to provide an overview of applying the 3DP and tissue engineering concepts for cancer studies with suggestions for future research directions. The 3DP technologies being used for the fabrication of personalized DDS have been highlighted and the potential technical approaches and challenges associated with the fused deposition modeling, the inkjet-powder bed, and stereolithography as the most promising 3DP techniques for drug delivery purposes are briefly described. Then, the advances, challenges, and future perspectives in tissue-engineered cancer models for precision medicine are discussed. Overall, future advances in this arena depend on the continuous integration of knowledge from cancer biology, biofabrication techniques, multiomics and patient data, and medical needs to develop effective treatments ultimately leading to improved clinical outcomes. Impact statement Three-dimensional printing (3DP) enables the fabrication of personalized medicines and drug delivery systems. The convergence of 3DP, tissue engineering concepts, and cancer biology could significantly improve our understanding of cancer biology and contribute to the development of new cancer therapies.