Reproducible preclinical models of androgen receptor driven human prostate cancer bone metastasis.

BACKGROUND: Preclinical models recapitulating the metastatic phenotypes are essential for developing the next-generation therapies for metastatic prostate cancer (mPC). We aimed to establish a cohort of clinically relevant mPC models, particularly androgen receptor positive (AR+) bone metastasis models, from LuCaP patient-derived xenografts (PDX) that reflect the heterogeneity and complexity of mPC. METHODS: PDX tumors were dissociated into single cells, modified to express luciferase, and were inoculated into NSG mice via intracardiac injection. The progression of metastases was monitored by bioluminescent imaging. Histological phenotypes of metastases were characterized by immunohistochemistry and immunofluorescence staining. Castration responses were further investigated in two AR-positive models. RESULTS: Our PDX-derived metastasis (PDM) model collection comprises three AR+ adenocarcinomas (ARPC) and one AR- neuroendocrine carcinoma (NEPC). All ARPC models developed bone metastases with either an osteoblastic, osteolytic, or mixed phenotype, while the NEPC model mainly developed brain metastasis. Different mechanisms of castration resistance were observed in two AR+ PDM models with distinct genotypes, such as combined loss of TP53 and RB1 in one model and expression of AR splice variant 7 (AR-V7) expression in another model. Intriguingly, the castration-resistant tumors displayed inter- and intra-tumor as well as organ-specific heterogeneity in lineage specification. CONCLUSION: Genetically diverse PDM models provide a clinically relevant system for biomarker identification and personalized medicine in metastatic castration-resistant prostate cancer.

Stem cell dynamics and cellular heterogeneity across lineage subtypes of castrate-resistant prostate cancer.

To resist lineage-dependent therapies such as androgen receptor inhibition, prostate luminal epithelial adenocarcinoma cells often adopt a stem-like state resulting in lineage plasticity and phenotypic heterogeneity. Castrate-resistant prostate adenocarcinoma can transition to neuroendocrine (NE) and occasionally to amphicrine, co-expressed luminal and NE, phenotypes. We developed castrate-resistant prostate cancer (CRPC) patient-derived organoid models that preserve heterogeneity of the originating tumor, including an amphicrine model displaying a range of luminal and NE phenotypes. To gain biological insight and to identify potential treatment targets within heterogeneous tumor cell populations, we assessed the lineage hierarchy and molecular characteristics of various CRPC tumor subpopulations. Transcriptionally similar stem/progenitor (St/Pr) cells were identified for all lineage populations. Lineage tracing in amphicrine CRPC showed that heterogeneity originated from distinct subclones of infrequent St/Pr cells that produced mainly quiescent differentiated amphicrine progeny. By contrast, adenocarcinoma CRPC progeny originated from St/Pr cells and self-renewing differentiated luminal cells. Neuroendocrine prostate cancer (NEPC) was composed almost exclusively of self-renewing St/Pr cells. Amphicrine subpopulations were enriched for secretory luminal, mesenchymal, and enzalutamide treatment persistent signatures that characterize clinical progression. Finally, the amphicrine St/Pr subpopulation was specifically depleted with an AURKA inhibitor, which blocked tumor growth. These data illuminate distinct stem cell (SC) characteristics for subtype-specific CRPC in addition to demonstrating a context for targeting differentiation-competent prostate SCs.

Tumor-derived biomarkers predict efficacy of B7H3 antibody-drug conjugate treatment in metastatic prostate cancer models.

Antibody-drug conjugates (ADCs) are a promising targeted cancer therapy; however, patient selection based solely on target antigen expression without consideration for cytotoxic payload vulnerabilities has plateaued clinical benefits. Biomarkers to capture patients who might benefit from specific ADCs have not been systematically determined for any cancer. We present a comprehensive therapeutic and biomarker analysis of a B7H3-ADC with pyrrolobenzodiazepine(PBD) payload in 26 treatment-resistant, metastatic prostate cancer (mPC) models. B7H3 is a tumor-specific surface protein widely expressed in mPC, and PBD is a DNA cross-linking agent. B7H3 expression was necessary but not sufficient for B7H3-PBD-ADC responsiveness. RB1 deficiency and/or replication stress, characteristics of poor prognosis, and conferred sensitivity were associated with complete tumor regression in both neuroendocrine (NEPC) and androgen receptor positive (ARPC) prostate cancer models, even with low B7H3 levels. Non-ARPC models, which are currently lacking efficacious treatment, demonstrated the highest replication stress and were most sensitive to treatment. In RB1 WT ARPC tumors, SLFN11 expression or select DNA repair mutations in SLFN11 nonexpressors governed response. Importantly, WT TP53 predicted nonresponsiveness (7 of 8 models). Overall, biomarker-focused selection of models led to high efficacy of in vivo treatment. These data enable a paradigm shift to biomarker-driven trial designs for maximizing clinical benefit of ADC therapies.

Minimal change disease with papillary thyroid carcinoma: a report of two adult cases.

BACKGROUND: Minimal change disease (MCD), a pathological type of nephrotic syndrome (NS), can occur in patients with tumors. We report two adult cases of MCD associated with papillary thyroid carcinoma (PTC), known to be extremely rare in adults. CASE PRESENTATION: A 35-year-old female patient was simultaneously diagnosed with MCD and PTC. The MCD was effectively treated with thyroidectomy and prednisone.In addition, a 50-year-old male patient, who had been diagnosed with PTC three years prior, had MCD confirmed by renal biopsy. The patient achieved complete remission following treatment with tacrolimus and rituximab. CONCLUSIONS: The present case report describes and discusses the diagnostic and treatment processes employed in these two patients. Clinicians need to be aware of the renal effects of treating patients with solid tumors.

Negatively charged polymer-shielded supramolecular nano-micelles with stimuli-responsive property for anticancer drug delivery.

A new kind of negatively charged polymer-shielded supramolecular nano-micelles with dual-responsive property was designed for tumor treatment, which was prepared on the basis of adamantane terminated linear PAsp(DIP) and disulfide-ß-cyclodextrin-terminated PAsp(EDA). The supramolecular nano-micelles comprised a 2,3-dimethylmaleic anhydride (DA) protective layer to stabilize the micelles, a pH-responsive core to package hydrophobic model drugs, and a disulfide-crosslinked interlayer to shackle the core against drug leakage under normal physiological conditions. After arriving at the tumor tissue via EPR, the targeting function could be turned on by dislodging DA groups on the surface of micelles, which allowed the drug-loaded nano-micelles to be easily phagocytized by the tumor cells, and then release the drug inside the cells induced by the increased glutathione level and acidic pH. The results indicated that the charge-conversional dual-responsive supramolecular nano-micelles showed excellent antitumor activity.

TMPRSS2-ERG promotes the initiation of prostate cancer by suppressing oncogene-induced senescence.

ERG translocations are commonly involved in the initiation of prostate neoplasia, yet previous experimental approaches have not addressed mechanisms of oncogenic inception. Here, in a genetically engineered mouse model, combining TMPRSS2-driven ERG with KrasG12D led to invasive prostate adenocarcinomas, while ERG or KrasG12D alone were non-oncogenic. In primary prostate luminal epithelial cells, following inducible oncogenic Kras expression or Pten depletion, TMPRSS2-ERG suppressed oncogene-induced senescence, independent of TP53 induction and RB1 inhibition. Oncogenic KRAS and TMPRSS2-ERG synergized to promote tumorigenesis and metastasis of primary luminal cells. The presence of TMPRSS2-ERG compared to a wild-type background was associated with a stemness phenotype and with relatively increased RAS-induced differential gene expression for MYC and mTOR-regulated pathways, including protein translation and lipogenesis. In addition, mTOR inhibitors abrogated ERG-dependent senescence resistance. These studies reveal a previously unappreciated function whereby ERG expression primes preneoplastic cells for the accumulation of additional gene mutations by suppression of oncogene-induced senescence.

The tumor phototherapeutic application of nanoparticles constructed by the relationship between PTT/PDT efficiency and 2,6- and 3,5-substituted BODIPY derivatives.

BODIPY dyes have recently been used for photothermal and photodynamic therapy of tumors. However, complex multi-material systems, multiple excitation wavelengths and the unclear relationship between BODIPY structures and their PTT/PDT efficiency are still major issues. In our study, nine novel BODIPY near-infrared dyes were designed and successfully synthesized and then, the relationships between BODIPY structures and their PTT/PDT efficiency were investigated in detail. The results showed that modifications at position 3,5 of the BODIPY core with conjugated structures have better effects on photothermal and photodynamic efficiency than the modifications at position 2,6 with halogen atoms. Density functional theory (DFT) calculations showed that this is mainly due to the extension of the conjugated chain and the photoinduced electron transfer (PET) effect. By encapsulating BDPX-M with amphiphilic DSPE-PEG2000-RGD and lecithin, the obtained NPs not only show good water solubility and biological stability, but also could act as superior agents for photothermal and photodynamic synergistic therapy of tumors. Finally, we obtained BODIPY NPs that exhibited excellent photothermal and photodynamic effects at the same time under single irradiation with an 808 nm laser (photothermal conversion efficiency: 42.76%, A/A0: ∼0.05). In conclusion, this work provides a direction to design and construct phototherapeutic nanoparticles based on BODIPY dyes for tumor treatment.

Multi-functional Nanodrug Based on a Three-dimensional Framework for Targeted Photo-chemo Synergetic Cancer Therapy.

Targeted synergistic therapy has broad prospects in tumor treatments. Here, a multi-functional nanodrug GDYO-CDDP/DOX@DSPE-PEG-MTX (GCDM) based on three traditional anticancer drugs (doxorubicin (DOX), cisplatin (CDDP) and methotrexate (MTX)) modified graphdiyne oxide (GDYO) is described, for diagnosis and targeted cancer photo-chemo synergetic therapy. In this system, for the first time, these three traditional anti-cancer drugs have played new roles and can reduce multidrug resistance through synergistic anti-tumor effects. Cisplatin can be hybridized with GDYO to form a multifunctional and well-dispersed three-dimensional framework, which can not only be used as nano-drug carriers to achieve high drug loading rates (40.3%), but also exhibit excellent photothermal conversion efficiency (47%) and good photodynamic effects under NIR irradiation. Doxorubicin (DOX) is loaded onto GDYO-CDDP through π-π stacking, which is used as an anticancer drug and as a fluorescent probe for nanodrug detection. Methotrexate (MTX) can be applied in tumor targeting and play a role in synergistic chemotherapy with DOX and CDDP. The synthesized multi-functional nanodrug GCDM has good biocompatibility, active targeting, long-term retention, sustained drug release, excellent fluorescence imaging capabilities, and remarkable photo-chemo synergistic therapeutic effects.

Acidity-Triggered Tumor-Targeted Nanosystem for Synergistic Therapy via a Cascade of ROS Generation and NO Release.

Nitric oxide (NO) gas therapy has aroused intense interest in recent years. l-Arginine (l-Arg) reacts with reactive oxygen species (ROS) in tumor cells to generate NO. This phenomenon represents an effective method for tumor therapy. However, endogenous ROS levels in most types of tumor cells cannot enable an effective reaction. ß-Lapachone is generally used to increase H2O2, which can oxidize guanidine derivatives to form nitric oxide in tumor cells. In addition, based on the ferrocene (Fc)-catalyzed Fenton reaction, ·OH is generated from H2O2, and the ONOO- could be generated from an interaction between ·O2- (generated through the Haber-Weiss reaction) and NO. Arg-rich poly(ε-caprolactone) (PCL)-b-PArg, a macromolecular NO donor, was accurately synthesized to avoid premature l-Arg leakage during in vivo transport. In this design, the self-assembled PCL-b-PArg nanoparticles were dressed with the tumor-shreddable masking (PEG-b-PDMA, a negatively charged pH-sensitive hydrophilic diblock polymer), to prepare P-lapa-Fc nanoparticles and hide penetrative capability in the circulation. The experimental results confirmed that this synergistic therapy based on ROS and NO had a significant inhibitory effect on cancer cells, thereby providing new inspiration for NO gas treatment.

Facile Synthesis of Ag/Pd Nanoparticle-Loaded Poly(ethylene imine) Composite Hydrogels with Highly Efficient Catalytic Reduction of 4-Nitrophenol.

Poly(ethylene imine) (PEI) has abundant amino groups in a macromolecular chain and can be used as a graft source for metal nanocomposites, which shows excellent ability to form stable complexes with heavy metal ions. In this work, a simple and convenient method was used to make PEI into a stable hydrogel with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-N-hydroxysuccinimide and subsequently coprecipitate with silver nitrate solution or palladium chloride solution to form metal-loaded composite hydrogels. In addition, the characterizations of composite hydrogels were investigated by scanning electron microscopy, specific surface area tests (Brunauer-Emmett-Teller), X-ray photoelectron spectroscopy, and ultraviolet spectroscopy. The properties of composite hydrogels on the catalytic reduction of 4-nitrophenol were studied. The results showed that the composite hydrogels could be easily separated from the water environment, which indicated the large-scale potential application in organic catalytic degradation and wastewater treatment.

Self-assembled functional components-doped conductive polypyrrole composite hydrogels with enhanced electrochemical performances.

A conductive hydrogel is a composite conductive material formed by combining a conductive polymer with a nanogel structure of a hydrogel. Conductive hydrogels not only have potential applications in supercapacitors, sensors, and modulators, they can also be synthesized by many methods, such as copolymerization, crosslinking, and grafting. In this work, we successfully prepared three conductive composite hydrogels by in situ polymerization, namely polypyrrole sodium alginate conductive hydrogel, ferric chloride-doped polypyrrole sodium alginate hydrogel and doped polypyrrole sodium alginate hydrogel with sodium dodecylbenzene sulfonate. In addition, a series of characterizations were performed for the three conductive hydrogels described above. The results show that the polypyrrole sodium alginate hydrogel doped with ferric chloride forms a nanofiber network with a more stable structure and better electrochemical performance.

Facile preparation of a self-assembled Artemia cyst shell-TiO2-MoS2 porous composite structure with highly efficient catalytic reduction of nitro compounds for wastewater treatment.

The catalytic reduction of nitro compounds is currently a hot research area, how to efficiently and stably degrade such toxic and harmful substances has become the research goal of many researchers. In this work, an Artemia cyst shell (ACS)-TiO2-MoS2 ternary porous structure was proposed and prepared as a catalyst for the reduction of 2-nitroaniline (2-NA) and 4-nitrophenol (4-NP). The ACS has a large number of porous structures, exhibits a good binding ability with TiO2 and MoS2, and provides a large number of active sites for the catalytic reduction process. The obtained composite material has a good reduction effect on 4-NP and 2-NA, with a good stability and recyclability, which is obviously higher than the reduction effect of ACS-TiO2 and MoS2 under the same conditions. This work provides ideas for the design of porous catalytic materials.

EGR1 regulates angiogenic and osteoclastogenic factors in prostate cancer and promotes metastasis.

Early growth response-1 (EGR1) is a transcription factor correlated with prostate cancer (PC) progression in a variety of contexts. For example, EGR1 levels increase in response to suppressed androgen receptor signaling or loss of the tumor suppressor, PTEN. EGR1 has been shown to regulate genes influencing proliferation, apoptosis, immune cell activation, and matrix degradation, among others. Despite this, the impact of EGR1 on PC metastatic colonization is unclear. We demonstrate using a PC model (DU145/RasB1) of bone and brain metastasis that EGR1 expression regulates angiogenic and osteoclastogenic properties of metastases. We have shown previously that FN14 (TNFRSF12A) and downstream NF-κB signaling is required for metastasis in this model. Here we demonstrate that FN14 ligation also leads to NF-κB-independent, MEK-dependent EGR1 expression. EGR1-depletion in DU145/RasB1 cells reduced both the number and size of metastases but did not affect primary tumor growth. Decreased EGR1 expression led to reduced blood vessel density in brain and bone metastases as well as decreased osteolytic bone lesion area and reduced numbers of osteoclasts at the bone-tumor interface. TWEAK (TNFSF12) induced several EGR1-dependent angiogenic and osteoclastogenic factors (e.g., PDGFA, TGFB1, SPP1, IL6, IL8, and TGFA, among others). Consistent with this, in clinical samples of PC, the level of several genes encoding angiogenic/osteoclastogenic pathway effectors correlated with EGR1 levels. Thus, we show here that EGR1 has a direct effect on prostate cancer metastases. EGR1 regulates angiogenic and osteoclastogenic factors, informing the underlying signaling networks that impact autonomous and microenvironmental mechanisms of cancer metastases.

Matrix remodeling associated 7 promotes differentiation of bone marrow mesenchymal stem cells toward osteoblasts.

The matrix remodeling associated 7 (MXRA7) gene had been ill-studied and its biology remained to be discovered. Inspired by our previous findings and public datasets concerning MXRA7, we hypothesized that the MXRA7 gene might be involved in bone marrow mesenchymal stem cells (BMSCs) functions related to bone formation, which was checked by utilizing in vivo or in vitro methodologies. Micro-computed tomography of MXRA7-deficient mice demonstrated retarded osteogenesis, which was reflected by shorter femurs, lower bone mass in both trabecular and cortical bones compared with wild-type (WT) mice. Histology confirmed the osteopenia-like feature including thinner growth plates in MXRA7-deficient femurs. Immunofluorescence revealed less osteoblasts in MXRA7-deficient femurs. Polymerase chain reaction or western blot analysis showed that when WT BMSCs were induced to differentiate toward osteoblasts or adipocytes in culture, MXRA7 messenger RNA or protein levels were significantly increased alongside osteoblasts induction, but decreased upon adipocytes induction. Cultured MXRA7-deficient BMSCs showed decreased osteogenesis upon osteogenic differentiation induction as reflected by decreased calcium deposition or lower expression of genes responsible for osteogenesis. When recombinant MXRA7 proteins were supplemented in a culture of MXRA7-deficient BMSCs, osteogenesis or gene expression was fully restored. Upon osteoblast induction, the level of active ß-catenin or phospho-extracellular signal-regulated kinase in MXRA7-deficient BMSCs was decreased compared with that in WT BMSCs, and these impairments could be rescued by recombinant MXRA7 proteins. In adipogenesis induction settings, the potency of MXRA7-deficient BMSCs to differentiate into adipocytes was increased over the WT ones. In conclusion, this study demonstrated that MXRA7 influences bone formation via regulating the balance between osteogenesis and adipogenesis in BMSCs.

High-throughput screens identify HSP90 inhibitors as potent therapeutics that target inter-related growth and survival pathways in advanced prostate cancer.

The development of new treatments for castrate resistant prostate cancer (CRPC) must address such challenges as intrinsic tumor heterogeneity and phenotypic plasticity. Combined PTEN/TP53 alterations represent a major genotype of CRPC (25-30%) and are associated with poor outcomes. Using tumor-derived, castration-resistant Pten/Tp53 null luminal prostate cells for comprehensive, high-throughput, mechanism-based screening, we identified several vulnerabilities among >1900 compounds, including inhibitors of: PI3K/AKT/mTOR, the proteasome, the cell cycle, heat shock proteins, DNA repair, NFκB, MAPK, and epigenetic modifiers. HSP90 inhibitors were one of the most active compound classes in the screen and have clinical potential for use in drug combinations to enhance efficacy and delay the development of resistance. To inform future design of rational drug combinations, we tested ganetespib, a potent second-generation HSP90 inhibitor, as a single agent in multiple CRPC genotypes and phenotypes. Ganetespib decreased growth of endogenous Pten/Tp53 null tumors, confirming therapeutic activity in situ. Fifteen human CRPC LuCaP PDX-derived organoid models were assayed for responses to 110 drugs, and HSP90 inhibitors (ganetespib and onalespib) were among the select group of drugs (<10%) that demonstrated broad activity (>75% of models) at high potency (IC50 <1 µM). Ganetespib inhibits multiple targets, including AR and PI3K pathways, which regulate mutually compensatory growth and survival signals in some forms of CRPC. Combined with castration, ganetespib displayed deeper PDX tumor regressions and delayed castration resistance relative to either monotherapy. In all, comprehensive data from near-patient models presents novel contexts for HSP90 inhibition in multiple CRPC genotypes and phenotypes, expands upon HSP90 inhibitors as simultaneous inhibitors of oncogenic signaling and resistance mechanisms, and suggests utility for combined HSP90/AR inhibition in CRPC.

A PDX/Organoid Biobank of Advanced Prostate Cancers Captures Genomic and Phenotypic Heterogeneity for Disease Modeling and Therapeutic Screening.

Purpose: Prostate cancer translational research has been hampered by the lack of comprehensive and tractable models that represent the genomic landscape of clinical disease. Metastatic castrate-resistant prostate cancer (mCRPC) patient-derived xenografts (PDXs) recapitulate the genetic and phenotypic diversity of the disease. We sought to establish a representative, preclinical platform of PDX-derived organoids that is experimentally facile for high-throughput and mechanistic analysis.Experimental Design: Using 20 models from the LuCaP mCRPC PDX cohort, including adenocarcinoma and neuroendocrine lineages, we systematically tested >20 modifications to prostate organoid conditions. Organoids were evaluated for genomic and phenotypic stability and continued reliance on the AR signaling pathway. The utility of the platform as a genotype-dependent model of drug sensitivity was tested with olaparib and carboplatin.Results: All PDX models proliferated as organoids in culture. Greater than 50% could be continuously cultured long-term in modified conditions; however, none of the PDXs could be established long-term as organoids under previously reported conditions. In addition, the modified conditions improved the establishment of patient biopsies over current methods. The genomic heterogeneity of the PDXs was conserved in organoids. Lineage markers and transcriptomes were maintained between PDXs and organoids. Dependence on AR signaling was preserved in adenocarcinoma organoids, replicating a dominant characteristic of CRPC. Finally, we observed maximum cytotoxicity to the PARP inhibitor olaparib in BRCA2-/- organoids, similar to responses observed in patients.Conclusions: The LuCaP PDX/organoid models provide an expansive, genetically characterized platform to investigate the mechanisms of pathogenesis as well as therapeutic responses and their molecular correlates in mCRPC. Clin Cancer Res; 24(17); 4332-45. ©2018 AACR.

Platelets Promote Metastasis via Binding Tumor CD97 Leading to Bidirectional Signaling that Coordinates Transendothelial Migration.

Tumor cells initiate platelet activation leading to the secretion of bioactive molecules, which promote metastasis. Platelet receptors on tumors have not been well-characterized, resulting in a critical gap in knowledge concerning platelet-promoted metastasis. We identify a direct interaction between platelets and tumor CD97 that stimulates rapid bidirectional signaling. CD97, an adhesion G protein-coupled receptor (GPCR), is an overexpressed tumor antigen in several cancer types. Purified CD97 extracellular domain or tumor cell-associated CD97 stimulated platelet activation. CD97-initiated platelet activation led to granule secretion, including the release of ATP, a mediator of endothelial junction disruption. Lysophosphatidic acid (LPA) derived from platelets induced tumor invasiveness via proximal CD97-LPAR heterodimer signaling, coupling coincident tumor cell migration and vascular permeability to promote transendothelial migration. Consistent with this, CD97 was necessary for tumor cell-induced vascular permeability in vivo and metastasis formation in preclinical models. These findings support targeted blockade of tumor CD97 as an approach to ameliorate metastatic spread.

Does the Fuhrman or World Health Organization/International Society of Urological Pathology Grading System Apply to the Xp11.2 Translocation Renal Cell Carcinoma?: A 10-Year Single-Center Study.

The Fuhrman and World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading systems are widely used to predict survival for patients with conventional renal cell carcinoma. To determine the validity of nuclear grading systems (both the Fuhrman and the WHO/ISUP) and the individual components of the Fuhrman grading system in predicting the prognosis of Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC), we identified and followed up 47 patients with Xp11.2 tRCC in our center from January 2007 to June 2017. The Fuhrman and WHO/ISUP grading was reassigned by two pathologists. Nuclear size and shape were determined for each case based on the greatest degree of nuclear pleomorphism using image analysis software. Univariate and multivariate analyses were performed to evaluate the capacity of the grading systems and nuclear parameters to predict overall survival and progression-free survival. On univariate Cox regression analysis, the parameters of nuclear size were associated significantly with overall survival and progression-free survival, whereas the grading systems and the parameters of nuclear shape failed to reach a significant correlation. On multivariate analysis, however, none of the parameters was associated independently with survival. Our findings indicate that neither the Fuhrman nor the WHO/ISUP grading system is applicable to Xp11.2 tRCC. The assessment of nuclear size instead may be novel outcome predictors for patients with Xp11.2 tRCC.

Gambogic acid inhibits thioredoxin activity and induces ROS-mediated cell death in castration-resistant prostate cancer.

Advanced prostate cancer (PrCa) is treated with androgen deprivation therapy, and although there is usually a significant initial response, recurrence arises as castrate resistant prostate cancer (CRPC). New approaches are needed to treat this genetically heterogeneous, phenotypically plastic disease. CRPC with combined homozygous alterations to PTEN and TP53 comprise about 30% of clinical samples. We screened eleven traditional Chinese medicines against a panel of androgen-independent Pten/Tp53 null PrCa-derived cell lines and identified gambogic acid (GA) as a highly potent growth inhibitor. Mechanistic analyses revealed that GA disrupted cellular redox homeostasis, observed as elevated reactive oxygen species (ROS), leading to apoptotic and ferroptotic death. Consistent with this, we determined that GA inhibited thioredoxin, a necessary component of cellular anti-oxidative, protein-reducing activity. In other clinically relevant models, GA displayed submicromolar, growth inhibitory activity against a number of genomically-representative, CRPC patient derived xenograft organoid cultures. Inhibition of ROS with N-acetyl-cysteine partially reversed growth inhibition in CRPC organoids, demonstrating ROS imbalance and implying that GA may have additional mechanisms of action. These data suggest that redox imbalances initiated by GA may be useful, especially in combination therapies, for treating the heterogeneity and plasticity that contributes to the therapeutic resistance of CRPC.

Novel targeting of PEGylated liposomes for codelivery of TGF-ß1 siRNA and four antitubercular drugs to human macrophages for the treatment of mycobacterial infection: a quantitative proteomic study.

Tuberculosis (TB) is still a major public health issue in developing countries, and its chemotherapy is compromised by poor drug compliance and severe side effects. This study aimed to synthesize and characterize new multimodal PEGylated liposomes encapsulated with clinically commonly used anti-TB drugs with linkage to small interfering RNA (siRNA) against transforming growth factor-ß1 (TGF-ß1). The novel NP-siRNA liposomes could target THP-1-derived human macrophages that were the host cells of mycobacterium infection. The biological effects of the NP-siRNA liposomes were evaluated on cell cycle distribution, apoptosis, autophagy, and the gene silencing efficiency of TGF-ß1 siRNA in human macrophages. We also explored the proteomic responses to the newly synthesized NP-siRNA liposomes using the stable isotope labeling with amino acids in cell culture approach. The results showed that the multifunctional PEGylated liposomes were successfully synthesized and chemically characterized with a mean size of 265.1 nm. The novel NP-siRNA liposomes functionalized with the anti-TB drugs and TGF-ß1 siRNA were endocytosed efficiently by human macrophages as visualized by transmission electron microscopy and scanning electron microscopy. Furthermore, the liposomes showed a low cytotoxicity toward human macrophages. There was no significant effect on cell cycle distribution and apoptosis in THP-1-derived macrophages after drug exposure at concentrations ranging from 2.5 to 62.5 µg/mL. Notably, there was a 6.4-fold increase in the autophagy of human macrophages when treated with the NP-siRNA liposomes at 62.5 µg/mL. In addition, the TGF-ß1 and nuclear factor-κB expression levels were downregulated by the NP-siRNA liposomes in THP-1-derived macrophages. The Ingenuity Pathway Analysis data showed that there were over 40 signaling pathways involved in the proteomic responses to NP-siRNA liposome exposure in human macrophages, with 160 proteins mapped. The top five canonical signaling pathways were eukaryotic initiation factor 2 signaling, actin cytoskeleton signaling, remodeling of epithelial adherens junctions, epithelial adherens junction signaling, and Rho GDP-dissociation inhibitor signaling pathways. Collectively, the novel synthetic targeting liposomes represent a promising delivery system for anti-TB drugs to human macrophages with good selectivity and minimal cytotoxicity.