scholarly journals Small Molecule-Based Prodrug Targeting Prostate Specific Membrane Antigen for the Treatment of Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 417
Author(s):  
Xinning Wang ◽  
Aditi Shirke ◽  
Ethan Walker ◽  
Rongcan Sun ◽  
Gopolakrishnan Ramamurthy ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Small Molecule ◽  
Targeted Delivery ◽  
Treatment Options ◽  
Maximum Tolerated Dose ◽  
In Vivo Studies ◽  
Castration Resistant Prostate Cancer ◽  
Drug Conjugates

Metastatic castration-resistant prostate cancer poses a serious clinical problem with poor outcomes and remains a deadly disease. New targeted treatment options are urgently needed. PSMA is highly expressed in prostate cancer and has been an attractive biomarker for the treatment of prostate cancer. In this study, we explored the feasibility of targeted delivery of an antimitotic drug, monomethyl auristatin E (MMAE), to tumor tissue using a small-molecule based PSMA lig-and. With the aid of Cy5.5, we found that a cleavable linker is vital for the antitumor activity of the ligand–drug conjugate and have developed a new PSMA-targeting prodrug, PSMA-1-VcMMAE. In in vitro studies, PSMA-1-VcMMAE was 48-fold more potent in killing PSMA-positive PC3pip cells than killing PSMA-negative PC3flu cells. In in vivo studies, PSMA-1-VcMMAE significantly inhibited tumor growth leading to prolonged animal survival in different animal models, including metastatic prostate cancer models. Compared to anti-PSMA antibody-MMAE conjugate (PSMA-ADC) and MMAE, PSMA-1-VcMMAE had over a 10-fold improved maximum tolerated dose, resulting in improved therapeutic index. The small molecule–drug conjugates reported here can be easily synthesized and are more cost efficient than anti-body–drug conjugates. The therapeutic profile of the PSMA-1-VcMMAE encourages further clin-ical development for the treatment of advanced prostate cancer.

scholarly journals A Review of the Potential of Phytochemicals from Prunus africana (Hook f.) Kalkman Stem Bark for Chemoprevention and Chemotherapy of Prostate Cancer

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Richard Komakech ◽  
Youngmin Kang ◽  
Jun-Hwan Lee ◽  
Francis Omujal
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Treatment Options ◽  
Chemotherapeutic Agents ◽  
Sub Saharan Africa ◽  
In Vivo Studies ◽  
Prostate Cancer Cells ◽  
Prunus Africana

Prostate cancer remains one of the major causes of death worldwide. In view of the limited treatment options for patients with prostate cancer, preventive and treatment approaches based on natural compounds can play an integral role in tackling this disease. Recent evidence supports the beneficial effects of plant-derived phytochemicals as chemopreventive and chemotherapeutic agents for various cancers, including prostate cancer. Prunus africana has been used for generations in African traditional medicine to treat prostate cancer. This review examined the potential roles of the phytochemicals from P. africana, an endangered, sub-Saharan Africa plant in the chemoprevention and chemotherapy of prostate cancer. In vitro and in vivo studies have provided strong pharmacological evidence for antiprostate cancer activities of P. africana-derived phytochemicals. Through synergistic interactions between different effective phytochemicals, P. africana extracts have been shown to exhibit very strong antiandrogenic and antiangiogenic activities and have the ability to kill tumor cells via apoptotic pathways, prevent the proliferation of prostate cancer cells, and alter the signaling pathways required for the maintenance of prostate cancer cells. However, further preclinical and clinical studies ought to be done to advance and eventually use these promising phytochemicals for the prevention and chemotherapy of human prostate cancer.

scholarly journals Targeted molecular-genetic imaging and ligand-directed therapy in aggressive variant prostate cancer

2016 ◽  
Vol 113 (45) ◽  
pp. 12786-12791 ◽  
Author(s):  
Fortunato Ferrara ◽  
Daniela I. Staquicini ◽  
Wouter H. P. Driessen ◽  
Sara D’Angelo ◽  
Andrey S. Dobroff ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Treatment Options ◽  
Molecular Genetic ◽  
Preclinical Model ◽  
Dual Function ◽  
Castration Resistant Prostate Cancer ◽  
Candidate Target ◽  
Aggressive Variant

Aggressive variant prostate cancers (AVPC) are a clinically defined group of tumors of heterogeneous morphologies, characterized by poor patient survival and for which limited diagnostic and treatment options are currently available. We show that the cell surface 78-kDa glucose-regulated protein (GRP78), a receptor that binds to phage-display-selected ligands, such as the SNTRVAP motif, is a candidate target in AVPC. We report the presence and accessibility of this receptor in clinical specimens from index patients. We also demonstrate that human AVPC cells displaying GRP78 on their surface could be effectively targeted both in vitro and in vivo by SNTRVAP, which also enabled specific delivery of siRNA species to tumor xenografts in mice. Finally, we evaluated ligand-directed strategies based on SNTRVAP-displaying adeno-associated virus/phage (AAVP) particles in mice bearing MDA-PCa-118b, a patient-derived xenograft (PDX) of castration-resistant prostate cancer bone metastasis that we exploited as a model of AVPC. For theranostic (a merging of the terms therapeutic and diagnostic) studies, GRP78-targeting AAVP particles served to deliver the human Herpes simplex virus thymidine kinase type-1 (HSVtk) gene, which has a dual function as a molecular-genetic sensor/reporter and a cell suicide-inducing transgene. We observed specific and simultaneous PET imaging and treatment of tumors in this preclinical model of AVPC. Our findings demonstrate the feasibility of GPR78-targeting, ligand-directed theranostics for translational applications in AVPC.

scholarly journals Development of Novel Chalcone Analogs as Potential Multi-Targeted Therapies for Castration-Resistant Prostate Cancer

2021 ◽  
Author(s):  
Ola Hussein ◽  
Feras Alali ◽  
Ala‐Eddin Al Mustafa ◽  
Ashraf Khalil
Keyword(s):  
Prostate Cancer ◽  
Cell Lines ◽  
In Vivo Studies ◽  
Treatment Modalities ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
Biological Studies ◽  
In Silico Admet

Prostate cancer (PCa) is the second most frequently diagnosed malignancy, as well as a leading cause of cancer-related mortality in men globally. Despite the initial response to hormonal targeted therapy, the majority of patients ultimately progress to a lethal form of the disease, castration-resistant prostate cancer (CRPC). Therefore, the objective of this study was to discover and develop novel treatment modalities for CRPC. Chalcones are among the highly attractive scaffolds being investigated for their antitumor activities. A library of 26 chalcone analogs were designed, synthesized and evaluated as potential therapies for CRPC. The design was guided by in-silico ADMET prediction in which analogs with favorable drug-likeness properties were prioritized. The new compounds were synthesized, purified and characterized by extensive structural elucidation studies. The compounds in vitro cytotoxicity was evaluated against two androgen receptor (AR)-negative prostate cancer cell lines (PC3 and DU145). Among the tested compounds, pyridine containing analogs (13, 15 and 16) showed potent antiproliferative activities with IC50 values ranging between 4.32-6.47 µM against PC3 and DU145 cell lines. Detailed biological studies of the lead molecule 16 revealed that it can significantly induce apoptosis through upregulation of Bax and downregulation of Bcl-2. In addition, compound 16 potently inhibited colony formation and reduced cell migration of AR-negative PCa cell lines (PC3 and DU145). The molecular pathway analysis showed that the anticancer activity of compound 16 is associated with blocking of ERK1/2 and Akt activities. Furthermore, compound 16 inhibited angiogenesis in the chick chorioallantoic membrane (CAM) model as compared to control. Structure-activity relationship study revealed that the cytotoxicity could dramatically improve via changing the methoxylation pattern by more than 2-folds (IC50 << 2.5 μM). These results indicate that pyridine-based chalcones could serve as promising lead molecules for the treatment of CRPC; thus, further in vitro and in vivo studies are warranted.

scholarly journals Inhibition of GATA2 in prostate cancer by a clinically available small molecule

2021 ◽  
Author(s):  
Salma Kaochar ◽  
Aleksandra Rusin ◽  
Christopher Foley ◽  
Kimal Rajapakshe ◽  
Matthew Robertson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Small Molecule ◽  
Global Gene Expression ◽  
Castration Resistant Prostate Cancer ◽  
Protein Array Analysis ◽  
The Moment ◽  
Dna Binding Assay

Castration-resistant prostate cancer (CRPC) remains highly lethal and in need of novel, actionable therapeutic targets. The pioneer factor GATA2 is a significant prostate cancer (PC) driver and linked to poor prognosis. GATA2 directly promotes androgen receptor (AR) gene expression (both full-length and splice-variant) and facilitates AR binding to chromatin, recruitment of coregulators, and target gene transcription. Unfortunately, there is no clinically applicable GATA2 inhibitor available at the moment. Using a bioinformatics algorithm, we screened in silico 2,650 clinically relevant drugs for a potential GATA2 inhibitor. Validation studies used cytotoxicity assays (MTT), global gene expression analysis, reporter assay, reverse phase protein array analysis (RPPA), and immunoblotting. We examined target engagement via cellular thermal shift assay (CETSA), ChIP-qPCR, and GATA2 DNA-binding assay. We identified the vasodilator dilazep as a potential GATA2 inhibitor and confirmed on-target activity via CETSA. Dilazep exerted anticancer activity across a broad panel of GATA2-dependent PC cell lines in vitro and in a PDX model in vivo. Dilazep inhibited GATA2 recruitment to chromatin and suppressed the cell cycle program, transcriptional programs driven by GATA2, AR, and c-MYC, and the expression of several oncogenic drivers, including AR, c-MYC, FOXM1, CENPF, EZH2, UBE2C, and RRM2, as well as of several mediators of metastasis, DNA damage repair and stemness. In conclusion, we provide, via an extensive compendium of methodologies, proof-of-principle that a small molecule can inhibit GATA2 function and suppress its downstream AR, c-MYC, and other PC-driving effectors. We propose GATA2 as a therapeutic target in CRPC.

scholarly journals YAP1 overexpression contributes to the development of enzalutamide resistance by induction of cancer stemness and lipid metabolism in prostate cancer

Oncogene ◽  
2021 ◽  
Author(s):  
Hsiu-Chi Lee ◽  
Chien-Hui Ou ◽  
Yun-Chen Huang ◽  
Pei-Chi Hou ◽  
Chad J. Creighton ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Lipid Metabolism ◽  
Critical Issue ◽  
Castration Resistant Prostate Cancer ◽  
Cancer Stemness ◽  
New Treatment ◽  
Underlying Mechanisms ◽  
Transcriptional Complex

AbstractMetastatic castration-resistant prostate cancer (mCRPC) is a malignant and lethal disease caused by relapse after androgen-deprivation (ADT) therapy. Since enzalutamide is innovated and approved by US FDA as a new treatment option for mCRPC patients, drug resistance for enzalutamide is a critical issue during clinical usage. Although several underlying mechanisms causing enzalutamide resistance were previously identified, most of them revealed that drug resistant cells are still highly addicted to androgen and AR functions. Due to the numerous physical functions of AR in men, innovated AR-independent therapy might alleviate enzalutamide resistance and prevent production of adverse side effects. Here, we have identified that yes-associated protein 1 (YAP1) is overexpressed in enzalutamide-resistant (EnzaR) cells. Furthermore, enzalutamide-induced YAP1 expression is mediated through the function of chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII) at the transcriptional and the post-transcriptional levels. Functional analyses reveal that YAP1 positively regulates numerous genes related to cancer stemness and lipid metabolism and interacts with COUP-TFII to form a transcriptional complex. More importantly, YAP1 inhibitor attenuates the growth and cancer stemness of EnzaR cells in vitro and in vivo. Finally, YAP1, COUP-TFII, and miR-21 are detected in the extracellular vesicles (EVs) isolated from EnzaR cells and sera of patients. In addition, treatment with EnzaR-EVs induces the abilities of cancer stemness, lipid metabolism and enzalutamide resistance in its parental cells. Taken together, these results suggest that YAP1 might be a crucial factor involved in the development of enzalutamide resistance and can be an alternative therapeutic target in prostate cancer.

scholarly journals Single Domain Antibodies as Carriers for Intracellular Drug Delivery: A Proof of Principle Study

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 927
Author(s):  
Sebas D. Pronk ◽  
Erik Schooten ◽  
Jurgen Heinen ◽  
Esra Helfrich ◽  
Sabrina Oliveira ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Single Domain ◽  
Drug Conjugates ◽  
Intracellular Drug Delivery ◽  
Internalization Rate ◽  
Single Domain Antibodies ◽  
Different Characteristics

Antibody-drug conjugates (ADCs) are currently used for the targeted delivery of drugs to diseased cells, but intracellular drug delivery and therefore efficacy may be suboptimal because of the large size, slow internalization and ineffective intracellular trafficking of the antibody. Using a phage display method selecting internalizing phages only, we developed internalizing single domain antibodies (sdAbs) with high binding affinity to rat PDGFRβ, a receptor involved in different types of diseases. We demonstrate that these constructs have different characteristics with respect to internalization rates but all traffic to lysosomes. To compare their efficacy in targeted drug delivery, we conjugated the sdAbs to a cytotoxic drug. The conjugates showed improved cytotoxicity correlating to their internalization speed. The efficacy of the conjugates was inhibited in the presence of vacuolin-1, an inhibitor of lysosomal maturation, suggesting lysosomal trafficking is needed for efficient drug release. In conclusion, sdAb constructs with different internalization rates can be designed against the same target, and sdAbs with a high internalization rate induce more cell killing than sdAbs with a lower internalization rate in vitro. Even though the overall efficacy should also be tested in vivo, sdAbs are particularly interesting formats to be explored to obtain different internalization rates.

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