Metallic nanoparticles have fascinated scientist for over a century and are now heavily utilized in biomedical sciences and engineering. They are a focus of interest because of their huge potential in nanotechnology. Today these materials can be synthesized and modified with various chemical functional groups which allow them to be conjugated with antibodies, ligands, and drugs of interest and thus opening a wide range of potential applications in biotechnology, magnetic separation, and preconcentration of target analytes, targeted drug delivery, and vehicles for gene and drug delivery and more importantly diagnostic imaging. Moreover, various imaging modalities have been developed over the period of time such as MRI, CT, PET, ultrasound, SERS, and optical imaging as an aid to image various disease states. These imaging modalities differ in both techniques and instrumentation and more importantly require a contrast agent with unique physiochemical properties. This led to the invention of various nanoparticulated contrast agent such as magnetic nanoparticles (Fe3O4), gold, and silver nanoparticles for their application in these imaging modalities. In addition, to use various imaging techniques in tandem newer multifunctional nanoshells and nanocages have been developed. Thus in this review article, we aim to provide an introduction to magnetic nanoparticles (Fe3O4), gold nanoparticles, nanoshells and nanocages, and silver nanoparticles followed by their synthesis, physiochemical properties, and citing some recent applications in the diagnostic imaging and therapy of cancer.

Chimeric antigen receptor (CAR)‐T cell therapy has achieved considerable success in treating B‐cell hematologic malignancies. However, the challenges of extending CAR‐T therapy to other tumor types, particularly solid tumors, remain appreciable. There are substantial variabilities in CAR‐T cellular kinetics across CAR‐designs, CAR‐T products, dosing regimens, patient responses, disease types, tumor burdens, and lymphodepletion conditions. As a “living drug,” CAR‐T cellular kinetics typically exhibit four distinct phases: distribution, expansion, contraction, and persistence. The cellular kinetics of CAR‐T may correlate with patient responses, but which factors determine CAR‐T cellular kinetics remain poorly defined. Herein, we developed a cellular kinetic model to retrospectively characterize CAR‐T kinetics in 217 patients from 7 trials and compared CAR‐T kinetics across response status, patient populations, and tumor types. Based on our analysis results, CAR‐T cells exhibited a significantly higher cell proliferation rate and capacity but a lower contraction rate in patients who responded to treatment. CAR‐T cells proliferate to a higher degree in hematologic malignancies than in solid tumors. Within the assessed dose ranges (107‒109 cells), CAR‐T doses were weakly correlated with CAR‐T cellular kinetics and patient response status. In conclusion, the developed CAR‐T cellular kinetic model adequately characterized the multiphasic CAR‐T cellular kinetics and supported systematic evaluations of the potential influencing factors, which can have significant implications for the development of more effective CAR‐T therapies.

No abstract

Identification of epigenetic reversal agents for use in combination chemotherapies to treat human pancreatic ductal adenocarcinomas (PDAC) remains an unmet clinical need. Pharmacological inhibitors of Enhancer of Zeste Homolog 2 (EZH2) are emerging as potential histone methylation reversal agents for the treatment of various solid tumors and leukemia; however, the surprisingly small set of mRNA targets identified with EZH2 knockdown suggests novel mechanisms contribute to their anti-tumorigenic effects. Here, 3-deazaneplanocin-A (DZNep), an inhibitor of S-adenosyl-L-homocysteine hydrolase and EZH2 histone lysine-N-methyltransferase, significantly reprograms noncoding miRNA (miR) expression and dampens TGFβ1-induced epithelial-to-mesenchymal (EMT) signals in pancreatic cancer. In particular, miR-663a and miR-4787-5p were identified as PDAC-downregulated miRs that were reactivated by DZNep to directly target TGFβ1 for RNA interference. Lentiviral overexpression of miR-663a and miR-4787-5p reduced TGFβ1 synthesis and secretion in PDAC cells and partially phenocopied DZNep’s EMT-resisting effects, whereas locked nucleic acid (LNA) antagomiRs counteracted them. DZNep, miR-663a, and miR-4787-5p reduced tumor burden in vivo and metastases in an orthotopic mouse pancreatic tumor model. Taken together, these findings suggest the epigenetic reprogramming of miRs by synthetic histone methylation reversal agents as a viable approach to attenuate TGFβ1-induced EMT features in human PDAC and uncover putative miR targets involved in the process.

Despite tremendous success of chimeric antigen receptor (CAR) T cell therapy in clinical oncology, the dose-exposure-response relationship of CART cells in patients is poorly understood. Moreover, the key drug-and system-specific determinants leading to favourable clinical outcomes are also unknown. Here, we have developed a multiscale mechanistic PK-PD model for anti-BCMA (bb2121) CART cell therapy to characterize 1) in vitro target cell killing in multiple BCMA expressing tumor cell lines at varying E:T ratios, 2) preclinical in vivo tumor growth inhibition (TGI) and blood CART cell expansion in xenograft mice, and 3) clinical PK and PD biomarkers in multiple myeloma (MM) patients. Our translational PK-PD relationship was able to effectively describe the commonly observed multiphasic CART cell PK profile in clinic, consisting of rapid distribution, expansion, contraction and persistent phases, as well as accounted for the categorical individual responses in multiple myeloma to effectively calculate progression-free survival rates. Preclinical and clinical data analysis revealed comparable parameter estimates pertaining to CART cell functionality and suggested that patient baseline tumor burden could be more sensitive than dose levels towards overall extent of exposure (Cmax) after CART cell infusion. Virtual patient simulations also suggested a very steep dose-exposure-response relationship with CART cell therapy and indicated presence of a 'threshold' dose, beyond which a flat dose-response curve could be observed. Our simulations were concordant with multiple clinical observations discussed within this paper. Moving forward, this framework could be leveraged a priori, to explore multiple infusions and support preclinical/clinical development of future CART cell therapies.

Chimeric antigen receptor (CAR)-T cell therapy has achieved considerable success in treating B-cell hematologic malignancies. However, the challenges of extending CAR-T therapy to other tumor types, particularly solid tumors, remain appreciable. There are substantial variabilities in CAR-T cellular kinetics across CAR-designs, CAR-T products, dosing regimens, patient responses, disease types, tumor burdens, and lymphodepletion conditions. As a 'living drug', CAR-T cellular kinetics typically exhibit four distinct phases: distribution, expansion, contraction, and persistence. The cellular kinetics of CAR-T may correlate with patient responses, but which factors determine CAR-T cellular kinetics remain poorly defined. Herein, we developed a cellular kinetic model to retrospectively characterize CAR-T kinetics in 218 patients from 7 trials and systematically compared CAR-T kinetics across patient populations and tumor types. Based on our analysis results, CAR-T cells exhibited a significantly higher cell proliferation rate constant and capacity but a lower contraction rate constant in patients who responded to treatment. CAR-T cells proliferate at a higher rate constant in hematologic malignancies than in solid tumors. Within the assessed dose ranges (107‒109 cells), CAR-T doses were weakly correlated with CAR-T cellular kinetics and patient response status, suggesting steep dose-response curves. In conclusion, the developed CAR-T cellular kinetic model adequately characterized the multiphasic CAR-T cellular kinetics and supported systematic evaluations of the potentially influencing factors, which can have significant implications for the development of more effective CAR-T therapies.

Previous studies in our laboratory identified that 3-deazaneplanocin A (DZNep), a carbocyclic adenosine analog and histone methyl transferase inhibitor, suppresses TGFβ-induced epithelial-to-mesenchymal (EMT) characteristics. In addition, DZNep epigenetically reprograms miRNAs (miRs) to regulate endogenous TGFβ1 levels via miR-663/4787 mediated RNA interference (Mol Cancer Res. 2016 Sep 13. pii: molcanres.0083.2016) (1). While DZNep also attenuates exogenous TGFβ-induced EMT response, the mechanism of this inhibition was unclear. Here, DZNep induced miR-202-5p to target both TGFβ receptors, TGFBR1 and TGFBR2, for RNA interference and thereby contribute to the suppression of exogenous TGFβ-induced EMT in pancreatic cancer cells. Lentiviral overexpression of miR-202 significantly reduced the protein levels of both TGFβ receptors and suppressed TGFβ signaling and EMT phenotypic characteristics of cultured parenchymal pancreatic cancer cells. Consistently, transfection of anti-miRs against miR-202-5p resulted in increased TGFBR1 and TGFBR2 protein expressions and induced EMT characteristics in these cells. In stellate pancreatic cells, miR-202 overexpression slowed growth as well as reduced stromal extracellular membrane matrix (ECM) protein expression. In orthotopic pancreatic cancer mouse models, both immunodeficient and immunocompetent, miR-202 reduced tumor burden and metastasis. Together, these findings demonstrate an alternative mechanism of DZNep in suppressing TGFβ signaling at the receptor level and uncover the EMT suppressing role of miR-202 in pancreatic cancer. Implications These findings support the possibility of combining small molecule- (e.g., DZNep analogs) or large molecule- (e.g., miRs) based epigenetic modifiers with conventional nucleoside analogs (e.g., gemcitabine, capecitabine) to improve the anti-metastatic potential of current pancreatic cancer therapy.

Nucleoside analogs are used as chemotherapeutic options for the treatment of platinum-resistant ovarian cancers. Human concentrative nucleoside transporter 1 (hCNT1) is implicated in sensitizing solid tumors to nucleoside analogs although its role in determining drug efficacy in ovarian cancers remains unclear. Here we examined the functional expression of hCNT1 and compared its contributions towards gemcitabine efficacy in histological subtypes of ovarian cancer. Radioactivity analysis identified hCNT1-mediated 3H-gemcitabine transport in ovarian cancer cells to be significantly reduced compared with that of normal ovarian surface epithelial cells. Biochemical and immunocytochemical analysis identified that unlike normal ovarian cells which expressed high levels of hCNT1 at the apical cell surface, the transporter was either diminished in expression and/or mislocalized in cell lines of various subtypes of ovarian cancer. Retroviral expression of hCNT1 selectively rescued gemcitabine transport in cell lines representing serous, teratocarcinoma, and endometrioid subtypes, but not clear cell carcinoma (CCC). In addition, exogenous hCNT1 predominantly accumulated in intracytoplasmic vesicles in CCC suggesting defective cellular trafficking of hCNT1 as a contributing factor to transport deficiency. Despite diminution of hCNT1 transport in the majority of ovarian cancers and apparent trafficking defects with CCC, the chemotherapeutic efficacy of gemcitabine was broadly enhanced in all subtypes when delivered via engineered nanoparticles (NPs). Additionally, by bypassing the transport requirement, the delivery of a gemcitabine-cisplatin combination in NP formulation increased their synergistic interactions. These findings uncover hCNT1 as a putative determinant for nucleoside analog chemoresistance in ovarian cancer and may help rationalize drug selection and delivery strategies for various histological subtypes of ovarian cancer.