Andrographolide inhibits Burkitt's lymphoma by binding JUN and CASP3 proteins

BACKGROUND

Burkitt's lymphoma, one of the most common subtypes of pediatric malignant lymphoma, is notorious for its swift onset, aggressive proliferation, pronounced invasiveness, and marked malignancy. The therapeutic landscape for Burkitt's lymphoma currently falls short of providing universally effective and tolerable solutions. Andrographolide, a primary active component of Andrographis paniculata, is renowned for its properties of heat-clearing, detoxification, inflammation reduction, and pain relief. It is predominantly used in treating bacterial and viral infections of the upper respiratory tract, as well as dysentery. Various reports highlight the antitumor effects of andrographolide. Yet, its specific impact and the underlying mechanism of action on Burkitt's lymphoma remain an uncharted area of research.

METHOD

We employed network pharmacology to pinpoint the targets of andrographolide's action on Burkitt's lymphoma and the associated pathways. We then evaluated the impact of andrographolide on Burkitt's lymphoma using both in vitro and in vivo patient-derived xenograft (PDX) models. Concurrently, we confirmed the molecular targets of andrographolide in Burkitt's lymphoma through immunofluorescence assays.

RESULT

Utilizing network pharmacology, we identified 15 relevant targets, 60 interrelationships between these targets, and numerous associated signaling pathways for andrographolide's action on Burkitt's lymphoma. In vitro efficacy tests using High-throughput Drug Sensitivity Testing and in vivo PDX model evaluations revealed that andrographolide effectively curtailed the growth of Burkitt's lymphoma. Moreover, we observed a increased in the expression of JUN (c-Jun) and CASP3 (Caspase 3) proteins in Burkitt's lymphoma cells treated with andrographolide.

CONCLUSION

Andrographolide inhibits the growth of Burkitt's lymphoma by inhibiting JUN and CASP3 proteins.

A Humanized Patient-Derived Xenograft Model for Pancreatic Cancer

Pancreatic cancer is associated with a high mortality rate, and there are still very few effective treatment options. Patient-derived xenografts have proven to be invaluable preclinical disease models to study cancer biology and facilitate testing of novel therapeutics. However, the severely immune-deficient mice used to generate standard models lack any functional immune system, thereby limiting their utility as a tool to investigate the tumor-immune cell interface. This chapter will outline a method for establishment of "humanized" patient-derived xenografts, which are reconstituted with human immune cells to imitate the immune-rich microenvironment of pancreatic cancer.

Patient-Derived Xenograft Models for Ovarian Cancer

Patient-derived xenograft (PDX) models play a crucial role for in vivo research. They maintain the original molecular characteristics of the human tumor and provide a more accurate tumor microenvironment, which cannot be replicated by in vitro models. This chapter describes four different transplantation methods, namely, intra-bursal, intrarenal capsule, intraperitoneal, and subcutaneous, to develop PDX models for ovarian cancer research.

ITC-6102RO, a novel B7-H3 antibody-drug conjugate, exhibits potent therapeutic effects against B7-H3 expressing solid tumors

BACKGROUND

The B7-H3 protein, encoded by the CD276 gene, is a member of the B7 family of proteins and a transmembrane glycoprotein. It is highly expressed in various solid tumors, such as lung and breast cancer, and has been associated with limited expression in normal tissues and poor clinical outcomes across different malignancies. Additionally, B7-H3 plays a crucial role in anticancer immune responses. Antibody-drug conjugates (ADCs) are a promising therapeutic modality, utilizing antibodies targeting tumor antigens to selectively and effectively deliver potent cytotoxic agents to tumors.

METHODS

In this study, we demonstrate the potential of a novel B7-H3-targeting ADC, ITC-6102RO, for B7-H3-targeted therapy. ITC-6102RO was developed and conjugated with dHBD, a soluble derivative of pyrrolobenzodiazepine (PBD), using Ortho Hydroxy-Protected Aryl Sulfate (OHPAS) linkers with high biostability. We assessed the cytotoxicity and internalization of ITC-6102RO in B7-H3 overexpressing cell lines in vitro and evaluated its anticancer efficacy and mode of action in B7-H3 overexpressing cell-derived and patient-derived xenograft models in vivo.

RESULTS

ITC-6102RO inhibited cell viability in B7-H3-positive lung and breast cancer cell lines, inducing cell cycle arrest in the S phase, DNA damage, and apoptosis in vitro. The binding activity and selectivity of ITC-6102RO with B7-H3 were comparable to those of the unconjugated anti-B7-H3 antibody. Furthermore, ITC-6102RO proved effective in B7-H3-positive JIMT-1 subcutaneously xenografted mice and exhibited a potent antitumor effect on B7-H3-positive lung cancer patient-derived xenograft (PDX) models. The mode of action, including S phase arrest and DNA damage induced by dHBD, was confirmed in JIMT-1 tumor tissues.

CONCLUSIONS

Our preclinical data indicate that ITC-6102RO is a promising therapeutic agent for B7-H3-targeted therapy. Moreover, we anticipate that OHPAS linkers will serve as a valuable platform for developing novel ADCs targeting a wide range of targets.

Towards an optimal model for gastric cancer peritoneal metastasis: current challenges and future directions

Peritoneal metastasis is a challenging aspect of clinical practice for gastric cancer. Animal models are crucial in understanding molecular mechanisms, assessing drug efficacy, and conducting clinical intervention studies, including those related to gastric cancer peritoneal metastasis. Unlike other xenograft models, peritoneal metastasis models should not only present tumor growth at the transplant site, but also recapitulate tumor cell metastasis in the abdominal cavity. Developing a reliable model of gastric cancer peritoneal metastasis involves several technical aspects, such as the selection of model animals, source of xenograft tumors, technology of transplantation, and dynamic monitoring of the tumor progression. To date, challenges remain in developing a reliable model that can completely recapitulate peritoneal metastasis. Thus, this review aims to summarize the techniques and strategies used to establish animal models of gastric cancer peritoneal metastasis, providing a reference for future model establishment.

Low Bcl-2 is a robust biomarker of sensitivity to nab-paclitaxel in Ewing sarcoma

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) shows potent preclinical anticancer activity in pediatric solid tumors such as Ewing sarcoma, rhabdomyosarcoma and neuroblastoma, but responses in clinical trials have been modest. In this work, we aimed to discover a rational biomarker-based approach to select the right candidate patients for this treatment. We assessed the efficacy of nab-paclitaxel in 27 patient-derived xenografts (PDX), including 14 Ewing sarcomas, five rhabdomyosarcomas and several other pediatric solid tumors. Response rate (partial or complete response) was remarkable in rhabdomyosarcomas (four of five) and Ewing sarcomas (four of 14). We addressed several predictive factors of response to nab-paclitaxel such as the expression of the secreted protein acidic and rich in cysteine (SPARC), chromosomal stability of cancer cells and expression of antiapoptotic members of the B-cell lymphoma-2 (Bcl-2) family of proteins such as Bcl-2, Bcl-xL, Bcl-W and Mcl-1. Protein (immunoblotting) and gene expression of SPARC correlated positively, while immunoblotting and immunohistochemistry expression of Bcl-2 correlated negatively with the efficacy of nab-paclitaxel in Ewing sarcoma PDX. The negative correlation of Bcl-2 immunoblotting signal and activity was especially robust (r = 0.8352; P = 0.0007; Pearson correlation). Consequently, we evaluated pharmacological strategies to inhibit Bcl-2 during nab-paclitaxel treatment. We observed that the Bcl-2 inhibitor venetoclax improved the activity of nab-paclitaxel in highly resistant Bcl-2-expressing Ewing sarcoma PDX. Overall, our results suggest that low Bcl-2 expression could be used to select patients with Ewing sarcoma sensitive to nab-paclitaxel, and Bcl-2 inhibitors could improve the activity of this drug in Bcl-2-expressing Ewing sarcoma.

Single-Cell and Spatial Analysis of Emergent Organoid Platforms

Organoids have emerged as a promising advancement of the two-dimensional (2D) culture systems to improve studies in organogenesis, drug discovery, precision medicine, and regenerative medicine applications. Organoids can self-organize as three-dimensional (3D) tissues derived from stem cells and patient tissues to resemble organs. This chapter presents growth strategies, molecular screening methods, and emerging issues of the organoid platforms. Single-cell and spatial analysis resolve organoid heterogeneity to obtain information about the structural and molecular cellular states. Culture media diversity and varying lab-to-lab practices have resulted in organoid-to-organoid variability in morphology and cell compositions. An essential resource is an organoid atlas that can catalog protocols and standardize data analysis for different organoid types. Molecular profiling of individual cells in organoids and data organization of the organoid landscape will impact biomedical applications from basic science to translational use.

Endoscopic Ultrasound-Guided Fine-Needle Biopsies to Generate Preclinical Disease Models to Study Inflammation in Pancreatic Ductal Adenocarcinoma

Patient-derived xenografts (PDXs) are valuable models to study cancer biology, behavior, and response to therapies in vivo. Pancreatic cancer is an aggressive and treatment-resistant disease, and typical biopsies are often of low cellular yield and therefore present challenges for the creation of PDXs. This chapter will describe a method to establish PDX models from tissue biopsies obtained via endoscopic ultrasound-guided fine-needle aspiration, a relatively noninvasive technique which compared to surgery is available to pancreatic cancer patients at all stages of disease. Furthermore, we also describe methods to incorporate "humanization" of PDXs via reconstitution with human immune cells, thus mimicking the immune cell-rich microenvironment of pancreatic tumors.

Establishment and genetically characterization of patient-derived xenograft models of cervical cancer

Purpose

Patient-derived xenograft (PDX) models were established to reproduce the clinical situation of original cancers and have increasingly been applied to preclinical cancer research. Our study was designed to establish and genetically characterize cervical cancer PDX models.

Methods

A total of 91 fresh fragments obtained from 22 surgically resected cervical cancer tissues were subcutaneously engrafted into female NOD-SCID mice. Hematoxylin and eosin (H&E) staining was performed to assess whether the established PDX models conserved the histological features of original patient cervical cancer tissues. Moreover, a Venn diagram was applied to display the overlap of all mutations detected in whole-genome sequencing (WGS) data from patient original cervical cancer (F0) and F2-, F3-PDX models. The whole exome sequencing (WES) and the “maftools” package were applied to determine the somatic mutations among primary cervical cancers and the established PDX models.

Results

Our study successfully developed a panel of cervical cancer PDX models and the latency time of cervical cancer PDX model establishment was variable with a progressive decrease as the passage number increased, with a mean time to initial growth of 94.71 days in F1 engraftment to 40.65 days in F3 engraftment. Moreover, the cervical cancer PDX models preserved the histological features of their original cervical cancer. WGS revealed that the genome of original cervical cancer was preserved with high fidelity in cervical cancer PDX models throughout the xenografting and passaging process. Furthermore, WES demonstrated that the cervical cancer PDX models maintained the majority somatic mutations of original cervical cancer, of which the KMT2D, LRP1B, NAV3, TP53, FAT1, MKI67 and PKHD1L1 genes were identified as the most frequently mutated genes.

Conclusions

The cervical cancer PDX models preserved the histologic and genetic characteristics of their original cervical cancer, which helped to gain a deeper insight into the genetic alterations and lay a foundation for further investigation of the molecular targeted therapy of cervical cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01342-5.

Establishment of childhood hepatoblastoma xenografts and evaluation of the anti-tumour effects of anlotinib, oxaliplatin and sorafenib

BACKGROUND

Hepatoblastoma (HB) is a common primary malignant liver tumour in children, mainly treated by means of traditional chemotherapy using platinum and doxorubicin (ADM). There has been limited progress in the research and development of new drugs for treating HB.

METHODS

A tumour biopsy from a child with HB was implanted into immunodeficient mice. The primary tumour and patient-derived xenograft (PDX) tumour were extensively characterised by histology, immunohistochemistry (IHC), and humanisation identification. We used the PDX model to evaluate the anti-tumour effects of anlotinib oxaliplatin (L-OHP) and sorafenib on childhood HB.

RESULTS

The established PDX model maintained the histological characteristics of the primary tumour. Anlotinib, L-OHP, and sorafenib can significantly inhibit the tumour growth in the PDX model. There was no obvious damage of the drugs to the heart, liver and kidney of the mice, and the side effects observed were light.

CONCLUSION

We have successfully established a PDX model of childhood HB. The model retains important molecular characteristics of human primary tumours. Using the model, it was found that anlotinib, L-OHP, and sorafenib have a good inhibitory effect on the growth of childhood HB. This provides a preliminary research basis for the clinical application of the drugs.

Opportunities and challenges of patient-derived models in cancer research: patient-derived xenografts, patient-derived organoid and patient-derived cells

Background

As reported, preclinical animal models differ greatly from the human body. The evaluation model may be the colossal obstacle for scientific research and anticancer drug development. Therefore, it is essential to propose efficient evaluation systems similar to clinical practice for cancer research.

Main body

While it has emerged for decades, the development of patient-derived xenografts, patient-derived organoid and patient-derived cell used to be limited. As the requirements for anticancer drug evaluation increases, patient-derived models developed rapidly recently, which is widely applied in basic research, drug development, and clinical application and achieved remarkable progress. However, there still lack systematic comparison and summarize reports for patient-derived models. In the current review, the development, applications, strengths, and challenges of patient-derived models in cancer research were characterized.

Conclusion

Patient-derived models are an indispensable approach for cancer research and human health.

Circulating CD34+ cells of primary myelofibrosis patients contribute to myeloid-dominant hematopoiesis and bone marrow fibrosis in immunodeficient mice

INTRODUCTION

Primary myelofibrosis (PMF) is a clonal stem cell disorder characterized by myeloid dominant hematopoiesis and dysregulated proliferation of fibroblasts in the bone marrow. However, how these aberrant myeloid cells and fibroblasts are produced remains unclear.

AIM AND METHODS

In this study, we examined in vivo engraftment kinetics of PMF patient-derived CD34+ cells in immunecompromised NOD/SCID/IL2rgKO (NSG) mice. Engrafted human cells were analyzed with flow cytometry, and proliferation of fibroblastic cells and bone marrow fibrosis were assessed with the histo-pathological examination.

RESULTS

Transplantation of PMF patient-derived circulating CD34+ fractions into NSG newborns recapitulates clinical features of human PMF. Engraftment of human CD45+ leukocytes resulted in anemia and myeloid hyperplasia accompanied by bone marrow fibrosis by six months post-transplantation. Fibrotic bone marrow contained CD45-vimentin+ cells of both human and mouse origin, suggesting that circulating malignant CD34+ subsets contribute to myelofibrotic changes in PMF through direct and indirect mechanisms.

CONCLUSION

A patient-derived xenotransplantation (PDX) model of PMF allows in vivo examination of disease onset and propagation originating from immature CD34+ cells and will support the investigation of pathogenesis and development of therapeutic modalities for the disorder.

SPARC-mediated long-term retention of nab-paclitaxel in pediatric sarcomas

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycoprotein overexpressed by several cancers. Because SPARC shows high binding affinity to albumin, we reasoned that pediatric sarcoma xenografts expressing SPARC would show enhanced uptake and accumulation of nanoparticle albumin-bound (nab)-paclitaxel, a potent anticancer drug formulation. We first evaluated the expression of SPARC in patient-derived xenografts (PDXs) of Ewing sarcoma, rhabdomyosarcoma and osteosarcoma, finding variable SPARC gene expression that correlated well with SPARC protein measured by immunoblotting. We revealed that the activity of the fusion gene chimera EWSR1-FLI1, the genetic driver of Ewing sarcoma, leads to lower expression of the gene SPARC in these tumors, likely due to enriched acetylation marks of the histone H3 lysine 27 at regions including the SPARC promoter and potential enhancers. Then, we used SPARC-edited Ewing sarcoma cells (A673 line) to demonstrate that SPARC knocked down (KD) cells accumulated significantly less amount of nab-paclitaxel in vitro than SPARC wild type (WT) cells. In vivo, SPARC KD and SPARC WT subcutaneous xenografts in mice achieved similar maximum intratumoral concentrations of nab-paclitaxel, though drug clearance from SPARC WT tumors was significantly slower. We confirmed such SPARC-mediated long-term intratumoral accumulation of nab-paclitaxel in Ewing sarcoma PDX with high expression of SPARC, which accumulated significantly more nab-paclitaxel than SPARC-low PDX. SPARC-high PDX responded better to nab-paclitaxel than SPARC-low tumors, although these results should be taken cautiously, given that the PDXs were established from different patients that could have specific determinants predisposing response to paclitaxel. In addition, SPARC KD Ewing sarcoma xenografts responded better to soluble docetaxel and paclitaxel than to nab-paclitaxel, while SPARC WT ones showed similar response to soluble and albumin-carried drugs. Overall, our results show that pediatric sarcomas expressing SPARC accumulate nab-paclitaxel for longer periods of time, which could have clinical implications for chemotherapy efficacy.

Establishment and characterization of an ovarian yolk sac tumor patient-derived xenograft model

OBJECTIVE

The lack of appropriate preclinical models of ovarian yolk sac tumor (OYST) is currently hindering the pursuit of new methods of treatment and investigation of the pathogenesis of the disease. We developed and characterized an OYST patient-derived xenograft (PDX) model in this study.

METHODS

Tumor fragments from a patient with an OYST were implanted subcutaneously into BALB/c Nude mice. Engrafted xenografts were compared with the original tumor according to histology, immunohistochemistry, humanized identified, and drug efficacy testing with in vivo treatment programs.

RESULTS

There was a high degree of histologic and immunohistochemical (IHC) resemblance between the established PDX model and its corresponding human tumors. Bleomycin, etoposide, and cisplatin (JEB) chemotherapy regimens were effective in clinical patients and were effective in the OYST PDX model; therefore, the effect of PDX intervention was consistent with clinical outcomes of OYSTs.

CONCLUSION

We have successfully established an OYST PDX model. This OYST model preserves the basic molecular features of the primary human tumor, thereby providing a valuable method to preclinically evaluate new treatments and explore disease pathogenesis.

Patient-Derived Xenografts from Solid Tumors (PDX) for Models of Metastasis

In cancer research, availability of clinically relevant tumor models is still essential for drug testing, proof of concept studies, and also molecular analyses. To achieve this, models are of advantage, which more closely reflect heterogeneity of tumors. In this regard, patient-derived xenograft (PDX) models more closely recapitulate the native tumor biology, tissue composition, and molecular characteristics. Since metastasis is still the major challenge of tumor therapy, models are pivotal, which resemble this particular property. In this context, PDX model-derived metastasis is of particular interest for testing antimetastatic therapies for their efficacy to better target this systemic disease. This protocol describes the establishment of PDX models from tumor specimen and their applicability for PDX-derived metastasis at metastatic sites such as liver and lung, which are also clinically relevant for the systemic spread of cancer. Analysis of metastasis and methods for quantification of metastatic spread are provided.

Patient-derived non-small cell lung cancer xenograft mirrors complex tumor heterogeneity

Objective

Patient-derived xenograft (PDX) models have shown great promise in preclinical and translational applications, but their consistency with primary tumors in phenotypic, genetic, and pharmacodynamic heterogeneity has not been well-studied. This study aimed to establish a PDX repository for non-small cell lung cancer (NSCLC) and to further elucidate whether it could preserve the heterogeneity within and between tumors in patients.

Methods

A total of 75 surgically resected NSCLC specimens were implanted into immunodeficient NOD/SCID mice. Based on the successful establishment of the NSCLC PDX model, we compared the expressions of vimentin, Ki67, EGFR, and PD-L1 proteins between cancer tissues and PDX models using hematoxylin and eosin staining and immunohistochemical staining. In addition, we detected whole gene expression profiling between primary tumors and PDX generations. We also performed whole exome sequencing (WES) analysis in 17 first generation xenografts to further assess whether PDXs retained the patient heterogeneities. Finally, paclitaxel, cisplatin, doxorubicin, atezolizumab, afatininb, and AZD4547 were used to evaluate the responses of PDX models to the standard-of-care agents.

Results

A large collection of serially transplantable PDX models for NSCLC were successfully developed. The histology and pathological immunohistochemistry of PDX xenografts were consistent with the patients' tumor samples. WES and RNA-seq further confirmed that PDX accurately replicated the molecular heterogeneities of primary tumors. Similar to clinical patients, PDX models responded differentially to the standard-of-care treatment, including chemo-, targeted- and immuno-therapeutics.

Conclusions

Our established PDX models of NSCLC faithfully reproduced the molecular, histopathological, and therapeutic characteristics, as well as the corresponding tumor heterogeneities, which provides a clinically relevant platform for drug screening, biomarker discovery, and translational research.

Enhanced anti-tumor efficacy of IL-7/CCL19-producing human CAR-T cells in orthotopic and patient-derived xenograft tumor models

Chimeric antigen receptor (CAR)-T cell therapy has impressive efficacy in hematological malignancies, but its application in solid tumors remains a challenge. Multiple hurdles associated with the biological and immunological features of solid tumors currently limit the application of CAR-T cells in the treatment of solid tumors. Using syngeneic mouse models, we recently reported that CAR-T cells engineered to concomitantly produce interleukin (IL)-7 and chemokine (C-C motif) ligand 19 (CCL19)-induced potent anti-tumor efficacy against solid tumors through an improved ability of migration and proliferation even in an immunosuppressive tumor microenvironment. In this study, for a preclinical evaluation preceding clinical application, we further explored the potential of IL-7/CCL19-producing human CAR-T cells using models that mimic the clinical features of solid tumors. Human anti-mesothelin CAR-T cells producing human IL-7/CCL19 achieved complete eradication of orthotopic pre-established malignant mesothelioma and prevented a relapse of tumors with downregulated antigen expression. Moreover, mice with patient-derived xenograft of mesothelin-positive pancreatic cancers exhibited significant inhibition of tumor growth and prolonged survival following treatment with IL-7/CCL19-producing CAR-T cells, compared to treatment with conventional CAR-T cells. Transfer of IL-7/CCL19-producing CAR-T cells resulted in an increase in not only CAR-T cells but also non-CAR-T cells within the tumor tissues and downregulated the expression of exhaustion markers, including PD-1 and TIGIT, on the T cells. Taken together, our current study elucidated the exceptional anti-tumor efficacy of IL-7/CCL19-producing human CAR-T cells and their potential for clinical application in the treatment of patients with solid tumors.

Development of a Novel Orthotopic Gastric Cancer Mouse Model

BACKGROUND

Gastric cancer metastasis is a highly fatal disease with a five-year survival rate of less than 5%. One major obstacle in studying gastric cancer metastasis is the lack of faithful models available. The cancer xenograft mouse models are widely used to elucidate the mechanisms of cancer development and progression. Current procedures for creating cancer xenografts include both heterotopic (i.e., subcutaneous) and orthotopic transplantation methods. Compared to the heterotopic model, the orthotopic model has been shown to be the more clinically relevant design as it enables the development of cancer metastasis. Although there are several methods in use to develop the orthotopic gastric cancer model, there is not a model which uses various types of tumor materials, such as soft tissues, semi-liquid tissues, or culture derivatives, due to the technical challenges. Thus, developing the applicable orthotopic model which can utilize various tumor materials is essential.

RESULTS

To overcome the known limitations of the current orthotopic gastric cancer models, such as exposure of tumor fragments to the neighboring organs or only using firm tissues for the orthotopic implantation, we have developed a new method allowing for the complete insertion of soft tissue fragments or homogeneously minced tissues into the stomach submucosa layer of the immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mouse. With this completely-closed transplantation method, tumors with various types of tissue may be used to establish orthotopic gastric cancer models without the risks of exposure to nearby organs or cell leakage. This surgical procedure was highly reproducible in generating forty-eight mouse models with a surgery success rate of 96% and tumor formation of 93%. Among four orthotopic patient-derived xenograft (PDX) models that we generated in this study, we verified that the occurrence of organotropic metastasis in either the liver or peritoneal cavity was the same as that of the donor patients.

CONCLUSION

Here we describe a new protocol, step by step, for the establishment of orthotopic xenograft of gastric cancer. This novel technique will be able to increase the use of orthotopic models in broader applications for not only gastric cancer research but also any research related to the stomach microenvironment.

Cytarabine nanotherapeutics with increased stability and enhanced lymphoma uptake for tailored highly effective therapy of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of B-cell non-Hodgkin lymphoma (B-NHL) with chronically relapsing clinical course. Implementation of cytarabine (araC) into induction and salvage regimen became standard of care for majority of MCL patients. In this study, tailored N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer nanotherapeutics containing covalently bound araC (araC co-polymers) were designed, synthesized and evaluated for their anti-lymphoma efficacy in vivo using a panel of six patient-derived lymphoma xenografts (PDX) derived from newly diagnosed and relapsed / refractory (R/R) MCL. While free araC led to temporary inhibition of growth of MCL tumors, araC co-polymers induced long-term disappearance of the engrafted lymphomas with no observed toxicity even in the case of PDX models derived from patients, who relapsed after high-dose araC-based treatments. The results provide sound preclinical rationale for the use of HPMA-based araC co-polymers in induction, salvage or palliative therapy of MCL patients.

Orthotopic Implants in Mice

By directly implanting patient tumor cells into mice in a relevant location, we can mimic both the biology and tumor microenvironment of the original tumor. Here we describe the process of generating an orthotopic patient derived xenograft model by injecting a single cell suspension of Ewing sarcoma cells into the femur of a recipient mouse.

Human T-ALL Xenografts

Intense chemotherapy regimens of patients diagnosed with T cell acute lymphoblastic leukemia (T-ALL) have proved successful for improving patient's overall survival, especially in children. But still T-ALL treatment remains challenging, since side effects of chemotherapeutic drugs often worsen patient's quality of life, and relapse rates remain significant. Hence, the availability of experimental animal models capable of recapitulating the biology of human T-ALL is obligatory as a critical tool to explore novel promising therapies directed against specific targets that have been previously validated in in vitro assays. For this purpose, patient-derived xenografts (PDX) of primary human T-ALL are currently of great interest as preclinical models for novel therapeutic strategies toward transition into clinical trials. In this chapter, we describe the lab workflow to perform PDX assays, from the initial processing of patient T-ALL samples, genetic in vitro modifications of leukemic cells by lentiviral transduction, inoculation routes, monitoring for disease development, and mouse organ examination, to administration of several treatments.

Integrin alpha-2 and beta-1 expression increases through multiple generations of the EDW01 patient-derived xenograft model of breast cancer-insight into their role in epithelial mesenchymal transition in vivo gained from an in vitro model system

Background

Breast cancers acquire aggressive capabilities via epithelial to mesenchymal transition (EMT), in which various integrins/integrin-linked kinase signalling are upregulated.

Methods

We investigated this in two patient-derived xenografts (PDXs) developed from breast-to-bone metastases, and its functional significance in a breast cancer cell line system. ED03 and EDW01 PDXs were grown subcutaneously in immunocompromised SCID mice through 11 passages and 7 passages, respectively. Tumour tissue was assessed using immunohistochemistry (IHC) for oestrogen receptor (ER)-alpha, E-cadherin, vimentin, Twist1, beta-catenin, P120-RasGAP, CD44, CD24 and Ki67, and RT-qPCR of EMT-related factors (CDH1, VIM, CD44, CD24), integrins beta 1 (ITGB1), alpha 2 (ITGA2) and ILK. Integrin and ILK expression in epidermal growth factor (EGF)-induced EMT of the PMC42-ET breast cancer cell line was assessed by RT-qPCR and Western blotting, as were the effects of their transient knockdown via small interfering RNA +/− EGF. Cell migration, changes in cell morphology and adhesion of siRNA-transfected PMC42-ET cells to various extracellular matrix (ECM) substrates was assessed.

Results

The ED03 (ER+/PR−/HER2−/lobular) and EDW01 (ER+/PR−/HER2−/ductal) PDXs were both classified as molecular subtype luminal A. ED03 xenografts exhibited mutated E-cadherin with minimal expression, but remained vimentin-negative across all passages. In EDW01, the hypoxic indicator gene CAIX and Twist1 were co-ordinately upregulated at passages 4–5, corresponding with a decrease in E-cadherin. At passages 6–7, VIM was upregulated along with ITGB1 and ITGA2, consistent with an increasing EMT. The ED03 PDX displayed minimal change over passages in mice, for all genes examined. ILK, ITGB1 and ITGA2 mRNAs were also increased in the EGF-induced EMT of PMC42-ET cells (in which CDH1 was downregulated) although siRNA against these targets revealed that this induction was not necessary for the observed EMT. However, their knockdown significantly reduced EMT-associated adhesion and Transwell migration.

Conclusion

Our data suggest that despite an increase in ITGA2 and ITGB1 gene expression in the EMT exhibited by EDW01 PDX over multiple generations, this pathway may not necessarily drive the EMT process.

Supplementary information

The online version contains supplementary material available at 10.1186/s13058-020-01366-8.

OKlahoma Nitrone-007: novel treatment for diffuse intrinsic pontine glioma

BACKGROUND

Diffuse intrinsic pontine glioma (DIPG) is the most common brainstem cancer in childhood. This rapidly progressing brainstem glioma holds a very dismal prognosis with median survival of less than 1 year. Despite extensive research, no significant therapeutic advancements have been made to improve overall survival in DIPG patients.

METHODS

Here, we used an orthotopic xenograft pediatric DIPG (HSJD-DIPG-007) mouse model to monitor the effects of anti-cancer agent, OKlahoma Nitrone-007 (OKN-007), as an inhibitor of tumor growth after 28 days of treatment. Using magnetic resonance imaging (MRI), we confirmed the previously described efficacy of LDN-193189, a known activin A receptor, type I (ACVR1) inhibitor, in decreasing tumor burden and found that OKN-007 was equally efficacious.

RESULTS

After 28 days of treatment, the tumor volumes were significantly decreased in OKN-007 treated mice (p < 0.01). The apparent diffusion coefficient (ADC), as a measure of tissue structural alterations, was significantly decreased in OKN-007 treated tumor-bearing mice (p < 0.0001). Histological analysis also showed a significant decrease in CD34 expression, essential for angiogenesis, of OKN-007 treated mice (p < 0.05) compared to LDN-193189 treated mice. OKN-007-treated mice also significantly decreased protein expression of the human nuclear antigen (HNA) (p < 0.001), ACVR1 (p < 0.0001), and c-MET (p < 0.05), as well as significantly increased expression of cleaved caspase 3 (p < 0.001) and histone H3 K27-trimethylation (p < 0.01), compared to untreated mouse tumors.

CONCLUSIONS

With the dismal prognosis and limited effective chemotherapy available for DIPG, there is significant room for continued research studies, and OKN-007 merits further exploration as a therapeutic agent.

Rare osteosarcoma cell subpopulation protein array and profiling using imaging mass cytometry and bioinformatics analysis

BACKGROUND

Single rare cell characterization represents a new scientific front in personalized therapy. Imaging mass cytometry (IMC) may be able to address all these questions by combining the power of MS-CyTOF and microscopy.

METHODS

We have investigated this IMC method using < 100 to up to 1000 cells from human sarcoma tumor cell lines by incorporating bioinformatics-based t-Distributed Stochastic Neighbor Embedding (t-SNE) analysis of highly multiplexed IMC imaging data. We tested this process on osteosarcoma cell lines TC71, OHS as well as osteosarcoma patient-derived xenograft (PDX) cell lines M31, M36, and M60. We also validated our analysis using sarcoma patient-derived CTCs.

RESULTS

We successfully identified heterogeneity within individual tumor cell lines, the same PDX cells, and the CTCs from the same patient by detecting multiple protein targets and protein localization. Overall, these data reveal that our t-SNE-based approach can not only identify rare cells within the same cell line or cell population, but also discriminate amongst varied groups to detect similarities and differences.

CONCLUSIONS

This method helps us make greater inroads towards generating patient-specific CTC fingerprinting that could provide an accurate tumor status from a minimally-invasive liquid biopsy.

Excipient-free nanodispersion of 7-ethyl-10-hydroxycamptothecin exerts potent therapeutic effects against pancreatic cancer cell lines and patient-derived xenografts

Irinotecan (CPT-11) is an anti-tumor drug and formulated as nanomedicines to reduce side effects and improve efficacy. In vivo, CPT-11 must be hydrolyzed by carboxylesterase to its active form 7-ethyl-10-hydroxycamptothecin (SN-38) to exert anti-tumor activity, but the lack of this enzyme in humans causes inefficient generation of SN-38. Thus, direct delivery of SN-38, not relying on carboxylesterase, will potentially achieve higher efficacy. However, it is difficult to effectively formulate SN-38 using current excipients due to its hydrophobicity and tendency to crystallize. Herein, we report the nanodispersion of SN-38 with its amphiphilic prodrug, CPT-11, as an effective treatment for pancreatic cancer (PC). SN-38 and CPT-11 formed stable nanoparticles without any other excipients, and showed potent cytotoxicity against PC cells in vitro, slowed tumor growth in vivo, namely subcutaneously and orthotopically xenografted mice, with minimal adverse effects, and prolonged their overall survival. Even in clinically-relevant patient-derived xenograft (PDX) models, the nanodispersion showed greater anti-tumor efficacy than CPT-11. Importantly, the nanodispersion directly released SN-38, resulting in carboxylesterase-independent anti-tumor activity, in contrast to carboxylesterase-dependent CPT-11. These characteristics may enable the excipient-free nanodispersion to exert potent therapeutic effects in patients.

Preclinical rationale for entinostat in embryonal rhabdomyosarcoma

Background

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric cancer population. Survival among metastatic RMS patients has remained dismal yet unimproved for years. We previously identified the class I-specific histone deacetylase inhibitor, entinostat (ENT), as a pharmacological agent that transcriptionally suppresses the PAX3:FOXO1 tumor-initiating fusion gene found in alveolar rhabdomyosarcoma (aRMS), and we further investigated the mechanism by which ENT suppresses PAX3:FOXO1 oncogene and demonstrated the preclinical efficacy of ENT in RMS orthotopic allograft and patient-derived xenograft (PDX) models. In this study, we investigated whether ENT also has antitumor activity in fusion-negative eRMS orthotopic allografts and PDX models either as a single agent or in combination with vincristine (VCR).

Methods

We tested the efficacy of ENT and VCR as single agents and in combination in orthotopic allograft and PDX mouse models of eRMS. We then performed CRISPR screening to identify which HDAC among the class I HDACs is responsible for tumor growth inhibition in eRMS. To analyze whether ENT treatment as a single agent or in combination with VCR induces myogenic differentiation, we performed hematoxylin and eosin (H&E) staining in tumors.

Results

ENT in combination with the chemotherapy VCR has synergistic antitumor activity in a subset of fusion-negative eRMS in orthotopic “allografts,” although PDX mouse models were too hypersensitive to the VCR dose used to detect synergy. Mechanistic studies involving CRISPR suggest that HDAC3 inhibition is the primary mechanism of cell-autonomous cytoreduction in eRMS. Following cytoreduction in vivo, residual tumor cells in the allograft models treated with chemotherapy undergo a dramatic, entinostat-induced (70–100%) conversion to non-proliferative rhabdomyoblasts.

Conclusion

Our results suggest that the targeting class I HDACs may provide a therapeutic benefit for selected patients with eRMS. ENT’s preclinical in vivo efficacy makes ENT a rational drug candidate in a phase II clinical trial for eRMS.

Electronic supplementary material

The online version of this article (10.1186/s13395-019-0198-x) contains supplementary material, which is available to authorized users.

Glutamine to proline conversion is associated with response to glutaminase inhibition in breast cancer

INTRODUCTION

Glutaminase inhibitors target cancer cells by blocking the conversion of glutamine to glutamate, thereby potentially interfering with anaplerosis and synthesis of amino acids and glutathione. The drug CB-839 has shown promising effects in preclinical experiments and is currently undergoing clinical trials in several human malignancies, including triple-negative breast cancer (TNBC). However, response to glutaminase inhibitors is variable and there is a need for identification of predictive response biomarkers. The aim of this study was to determine how glutamine is utilized in two patient-derived xenograft (PDX) models of breast cancer representing luminal-like/ER+ (MAS98.06) and basal-like/triple-negative (MAS98.12) breast cancer and to explore the metabolic effects of CB-839 treatment.

EXPERIMENTAL

MAS98.06 and MAS98.12 PDX mice received CB-839 (200 mg/kg) or drug vehicle two times daily p.o. for up to 28 days (n = 5 per group), and the effect on tumor growth was evaluated. Expression of 60 genes and seven glutaminolysis key enzymes were determined using gene expression microarray analysis and immunohistochemistry (IHC), respectively, in untreated tumors. Uptake and conversion of glutamine were determined in the PDX models using HR MAS MRS after i.v. infusion of [5-¹³C] glutamine when the models had received CB-839 (200 mg/kg) or vehicle for 2 days (n = 5 per group).

RESULTS

Tumor growth measurements showed that CB-839 significantly inhibited tumor growth in MAS98.06 tumors, but not in MAS98.12 tumors. Gene expression and IHC analysis indicated a higher proline synthesis from glutamine in untreated MAS98.06 tumors. This was confirmed by HR MAS MRS of untreated tumors demonstrating that MAS98.06 used glutamine to produce proline, glutamate, and alanine, and MAS98.12 to produce glutamate and lactate. In both models, treatment with CB-839 resulted in accumulation of glutamine. In addition, CB-839 caused depletion of alanine, proline, and glutamate ([1-13C] glutamate) in the MAS98.06 model.

CONCLUSION

Our findings indicate that TNBCs may not be universally sensitive to glutaminase inhibitors. The major difference in the metabolic fate of glutamine between responding MAS98.06 xenografts and non-responding MAS98.12 xenografts is the utilization of glutamine for production of proline. We therefore suggest that addiction to proline synthesis from glutamine is associated with response to CB-839 in breast cancer. The effect of glutaminase inhibition in two breast cancer patient-derived xenograft (PDX) models. ¹³C HR MAS MRS analysis of tumor tissue from CB-839-treated and untreated models receiving ¹³C-labeled glutamine ([5-¹³C] Gln) shows that the glutaminase inhibitor CB-839 is causing an accumulation of glutamine (arrow up) in two PDX models representing luminal-like breast cancer (MAS98.06) and basal-like breast cancer (MAS98.12). In MAS98.06 tumors, CB-839 is in addition causing depletion of proline ([5-¹³C] Pro), alanine ([1-¹³C] Ala), and glutamate ([1-¹³C] Glu), which could explain why CB-839 causes tumor growth inhibition in MAS98.06 tumors, but not in MAS98.12 tumors.

Factors that influence response classifications in chemotherapy treated patient-derived xenografts (PDX)

In this study, we investigated the impact of initial tumor volume, rate of tumor growth, cohort size, study duration, and data analysis method on chemotherapy treatment response classifications in patient-derived xenografts (PDXs). The analyses were conducted on cisplatin treatment response data for 70 PDX models representing ten cancer types with up to 28-day study duration and cohort sizes of 3-10 tumor-bearing mice. The results demonstrated that a 21-day dosing study using a cohort size of eight was necessary to reliably detect responsive models (i.e., tumor volume ratio of treated animals to control between 0.1 and 0.42)-independent of analysis method. A cohort of three tumor-bearing animals led to a reliable classification of models that were both highly responsive and highly nonresponsive to cisplatin (i.e., tumor volume ratio of treated animals to control animals less than 0.10). In our set of PDXs, we found that tumor growth rate in the control group impacted treatment response classification more than initial tumor volume. We repeated the study design factors using docetaxel treated PDXs with consistent results. Our results highlight the importance of defining endpoints for PDX dosing studies when deciding the size of cohorts to use in dosing studies and illustrate that response classifications for a study do not differ significantly across the commonly used analysis methods that are based on tumor volume changes in treatment versus control groups.

Characterization of drug responses of mini patient-derived xenografts in mice for predicting cancer patient clinical therapeutic response

Background

Patient-derived organoids and xenografts (PDXs) have emerged as powerful models in functional diagnostics with high predictive power for anticancer drug response. However, limitations such as engraftment failure and time-consuming for establishing and expanding PDX models followed by testing drug efficacy, and inability to subject to systemic drug administration for ex vivo organoid culture hinder realistic and fast decision-making in selecting the right therapeutics in the clinic. The present study aimed to develop an advanced PDX model, namely MiniPDX, for rapidly testing drug efficacy to strengthen its value in personalized cancer treatment.

Methods

We developed a rapid in vivo drug sensitivity assay, OncoVee^® MiniPDX, for screening clinically relevant regimens for cancer. In this model, patient-derived tumor cells were arrayed within hollow fiber capsules, implanted subcutaneously into mice and cultured for 7 days. The cellular activity morphology and pharmacokinetics were systematically evaluated. MiniPDX performance (sensitivity, specificity, positive and negative predictive values) was examined using PDX as the reference. Drug responses were examined by tumor cell growth inhibition rate and tumor growth inhibition rate in PDX models and MiniPDX assays respectively. The results from MiniPDX were also used to evaluate its predictive power for clinical outcomes.

Results

Morphological and histopathological features of tumor cells within the MiniPDX capsules matched those both in PDX models and in original tumors. Drug responses in the PDX tumor graft assays correlated well with those in the corresponding MiniPDX assays using 26 PDX models generated from patients, including 14 gastric cancer, 10 lung cancer and 2 pancreatic cancer. The positive predictive value of MiniPDX was 92%, and the negative predictive value was 81% with a sensitivity of 80% and a specificity of 93%. Through expanding to clinical tumor samples, MiniPDX assay showed potential of wide clinical application.

Conclusions

Fast in vivo MiniPDX assay based on capsule implantation was developed-to assess drug responses of both PDX tumor grafts and clinical cancer specimens. The high correlation between drug responses of paired MiniPDX and PDX tumor graft assay, as well as translational data suggest that MiniPDX assay is an advanced tool for personalized cancer treatment.

Decrease in phosphorylated ERK indicates the therapeutic efficacy of a clinical PI3Kα-selective inhibitor CYH33 in breast cancer

PI3Ks are frequently hyper-activated in breast cancer and targeting PI3Kα has exhibited promising but variable response in preclinical and clinical settings. CYH33 is a novel PI3Kα-selective inhibitor in phase I clinical trial. We investigated the efficacy of CYH33 against breast cancer and explored potential predictive biomarkers. CYH33 potently restrained tumor growth in mice bearing human breast cancer cell xenografts and in R26-Pik3ca^H1047R;MMTV-Cre transgenic mice. CYH33 significantly inhibited proliferation of a panel of human breast cancer cells, while diversity in sensitivity has been observed. Cells harboring activating PIK3CA mutation, amplified HER2 were more responsive to CYH33 than their counterparts. Besides, cells in HER2-enriched or luminal subtype were more sensitive to CYH33 than basal-like breast cancer. Sensitivity to CYH33 has been further revealed to be associated with induction of G1 phase arrest and simultaneous inhibition of Akt and ERK. Sensitivity of patient-derived xenograft to CYH33 was also positively correlated with decrease in phosphorylated ERK. Taken together, CYH33 is a promising PI3Kα inhibitor for breast cancer treatment and decrease in ERK phosphorylation may indicate its efficacy, which provides useful clues for rational design of the ongoing clinical trials.

Patient-derived xenografts as preclinical neuroblastoma models

The prognosis for children with high-risk neuroblastoma is often poor and survivors can suffer from severe side effects. Predictive preclinical models and novel therapeutic strategies for high-risk disease are therefore a clinical imperative. However, conventional cancer cell line-derived xenografts can deviate substantially from patient tumors in terms of their molecular and phenotypic features. Patient-derived xenografts (PDXs) recapitulate many biologically and clinically relevant features of human cancers. Importantly, PDXs can closely parallel clinical features and outcome and serve as excellent models for biomarker and preclinical drug development. Here, we review progress in and applications of neuroblastoma PDX models. Neuroblastoma orthotopic PDXs share the molecular characteristics, neuroblastoma markers, invasive properties and tumor stroma of aggressive patient tumors and retain spontaneous metastatic capacity to distant organs including bone marrow. The recent identification of genomic changes in relapsed neuroblastomas opens up opportunities to target treatment-resistant tumors in well-characterized neuroblastoma PDXs. We highlight and discuss the features and various sources of neuroblastoma PDXs, methodological considerations when establishing neuroblastoma PDXs, in vitro 3D models, current limitations of PDX models and their application to preclinical drug testing.

A novel hemolytic complement-sufficient NSG mouse model supports studies of complement-mediated antitumor activity in vivo

Monoclonal antibodies (mAbs) have emerged as a mainstream therapeutic option against cancer. mAbs mediate tumor cell-killing through several mechanisms including complement-dependent cytotoxicity (CDC). However, studies of mAb-mediated CDC against tumor cells remain largely dependent on in vitro systems. Previously developed and widely used NOD-scid IL2rγ^null (NSG) mice support enhanced engraftment of many primary human tumors. However, NSG mice have a 2-bp deletion in the coding region of the hemolytic complement (Hc) gene, and it is not possible to evaluate CDC activity in NSG mice. To address this limitation, we generated a novel strain of NSG mice-NSG-Hc¹-that have an intact complement system able to generate the membrane attack complex. Utilizing the Daudi Burkitt's human lymphoma cell line, and the anti-human CD20 mAb rituximab, we further demonstrated that the complement system in NSG-Hc¹ mice is fully functional. NSG-Hc¹ mice expressed CDC activity against Daudi cells in vivo following rituximab treatment and showed longer overall survival compared with rituximab-treated NSG mice that lack hemolytic complement. Our results validate the NSG-Hc¹ mouse model as a platform for testing mechanisms underlying CDC in vivo and suggest its potential use to compare complement-dependent and complement-independent cytotoxic activity mediated by therapeutic mAbs.

Development of a Patient-Derived Xenograft Model Using Brain Tumor Stem Cell Systems to Study Cancer

Patient-derived xenograft (PDX) models provide an excellent platform to understand cancer initiation and development in vivo. In the context of brain tumor initiating cells (BTICs), PDX models allow for characterization of tumor formation, growth, and recurrence, in a clinically relevant in vivo system. Here, we detail procedures to harvest, culture, characterize, and orthotopically inject human BTICs derived from patient samples.