Patient-derived scaffolds representing breast cancer microenvironments influence chemotherapy responses in adapted cancer cells consistent with clinical features.

BACKGROUND: The tumor microenvironment clearly influences cancer progressing properties but less is known about how individual cancer microenvironments potentially moderate cancer treatment effects. By cultivating and treating cancer cell lines in patient-derived scaffolds (PDS), the impact of specific characteristics of individual cancer microenvironments can be incorporated in human-like growth modelling and cancer drug treatment testing. METHODS: PDSs from 78 biobanked primary breast cancer samples with known patient outcomes, were prepared and repopulated with donor breast cancer cell lines, followed by treatment with 5-fluorouracil or doxorubicin after cellular adaption to the various microenvironments. Cancer cell responses to the treatments were monitored by RNA-analyses, highlighting changes in gene sets representative for crucial tumor biological processes such as proliferation, cancer stem cell features, differentiation and epithelial-to-mesenchymal transition. RESULTS: The chemotherapy treatments induced distinct gene expression patterns in adapted cancer cells with clusters of similar treatment responses depending on the patient-derived cancer microenvironment used as growth substrate. The doxorubicin treatment displayed a favorable gene signature among surviving cancer cells with low proliferation (MKI67) and pluripotency features (NANOG, POU5F1), in comparison to 5-fluorouracil showing low proliferation but increased pluripotency. Specific gene changes monitored post-treatment were also significantly correlated with clinical data, including histological grade (NANOG), lymph node metastasis (SLUG) and disease-free patient survival (CD44). CONCLUSIONS: This laboratory-based treatment study using patient-derived scaffolds repopulated with cancer cell lines, clearly illustrates that the human cancer microenvironment influences chemotherapy responses. The differences in treatment responses defined by scaffold-cultures have potential prognostic and treatment predictive values.

Breast cancer patient-derived scaffolds as a tool to monitor chemotherapy responses in human tumor microenvironments.

Breast cancer is a heterogeneous disease where the tumor microenvironment, including extracellular components, plays a crucial role in tumor progression, potentially modulating treatment response. Different approaches have been used to develop three-dimensional models able to recapitulate the complexity of the extracellular matrix. Here, we use cell-free patient-derived scaffolds (PDSs) generated from breast cancer samples that were recellularized with cancer cell lines as an in vivo-like culture system for drug testing. We show that PDS cultured MCF7 cancer cells increased their resistance against the front-line chemotherapy drugs 5-fluorouracil, doxorubicin and paclitaxel in comparison to traditional two-dimensional cell cultures. The gene expression of the environmentally adapted cancer cells was modulated in different ways depending on the drug and the concentration used. High doses of doxorubicin reduced cancer stem cell features, whereas 5-fluorouracil increased stemness and decreased the proliferative phenotype. By using PDSs repopulated with other breast cancer cell lines, T-47D and MDA-MB-231, we observed both general and cell line specific drug responses. In summary, PDSs can be used to examine the extracellular matrix influence on cancer drug responses and for testing novel compounds in in vivo-like microenvironments.

Breast Cancer Patient-Derived Scaffolds Can Expose Unique Individual Cancer Progressing Properties of the Cancer Microenvironment Associated with Clinical Characteristics.

Breast cancer is a heterogeneous disease in terms of cellular and structural composition, and besides acquired aggressive properties in the cancer cell population, the surrounding tumor microenvironment can affect disease progression and clinical behaviours. To specifically decode the clinical relevance of the cancer promoting effects of individual tumor microenvironments, we performed a comprehensive test of 110 breast cancer samples using a recently established in vivo-like 3D cell culture platform based on patient-derived scaffolds (PDSs). Cell-free PDSs were recellularized with three breast cancer cell lines and adaptation to the different patient-based microenvironments was monitored by quantitative PCR. Substantial variability in gene expression between individual PDS cultures from different patients was observed, as well as between different cell lines. Interestingly, specific gene expression changes in the PDS cultures were significantly linked to prognostic features and clinical information from the original cancer. This link was even more pronounced when ERα-status of cell lines and PDSs matched. The results support that PDSs cultures, including a cancer cell line of relevant origin, can monitor the activity of the tumor microenvironment and reveal unique information about the malignancy-inducing properties of the individual cancer niche and serve as a future complementary diagnostic tool for breast cancer.

Patient-derived scaffolds as a drug-testing platform for endocrine therapies in breast cancer.

Three-dimensional cell culture platforms based on decellularised patient-based microenvironments provide in vivo-like growth conditions allowing cancer cells to interact with intact structures and components of the surrounding tissue. A patient-derived scaffold (PDS) model was therefore evaluated as a testing platform for the endocrine therapies (Z)-4-Hydroxytamoxifen (4OHT) and fulvestrant as well as the CDK4/6-inhibitor palbociclib, monitoring the treatment responses in breast cancer cell lines MCF7 and T47D adapted to the patient-based microenvironments. MCF7 cells growing in PDSs showed increased resistance to 4OHT and fulvestrant treatment (100- and 20-fold) compared to 2D cultures. Quantitative PCR analyses of endocrine treated cancer cells in PDSs revealed upregulation of pluripotency markers further supported by increased self-renewal capacity in sphere formation assays. When comparing different 3D growth platforms including PDS, matrigel, gelatin sponges and 3D-printed hydrogels, 3D based cultures showed slightly varying responses to fulvestrant and palbociclib whereas PDS and matrigel cultures showed more similar gene expression profiles for 4OHT treatment compared to the other platforms. The results support that the PDS technique maximized to provide a multitude of smaller functional PDS replicates from each primary breast cancer, is an up-scalable patient-derived drug-testing platform available for gene expression profiling and downstream functional assays.

Optimized alginate-based 3D printed scaffolds as a model of patient derived breast cancer microenvironments in drug discovery.

The cancer microenvironment influences tumor progression and metastasis and is pivotal to consider when designingin vivo-like cancer models. Current preclinical testing platforms for cancer drug development are mainly limited to 2D cell culture systems that poorly mimic physiological environments and traditional, low throughput animal models. The aim of this work was to produce a tunable testing platform based on 3D printed scaffolds (3DPS) with a simple geometry that, by extracellular components and response of breast cancer reporter cells, mimics patient-derived scaffolds (PDS) of breast cancer. Here, the biocompatible polysaccharide alginate was used as base material to generate scaffolds consisting of a 3D grid containing periostin and hydroxyapatite. Breast cancer cell lines (MCF7 and MDA-MB-231) produced similar phenotypes and gene expression levels of cancer stem cell, epithelial-mesenchymal transition, differentiation and proliferation markers when cultured on 3DPS and PDS, contrasting conventional 2D cultures. Importantly, cells cultured on 3DPS and PDS showed scaffold-specific responses to cytotoxic drugs (doxorubicin and 5-fluorouracil) that were different from 2D cultured cells. In conclusion, the data presented support the use of a tunable alginate-based 3DPS as a tumor model in breast cancer drug discovery.

Tripalmitin nanoparticle formulations significantly enhance paclitaxel antitumor activity against breast and lung cancer cells in vitro.

Paclitaxel (PTX) is one of the drugs of choice in the treatment of breast and lung cancer. However, its severe side effects, including mielosuppression, cardiotoxicity and neurotoxicity, frequently cause treatment to be discontinued. Solid lipid nanoparticles (NPs) of glyceril tripalmitate (tripalmitin) loaded with PTX (Tripalm-NPs-PTX) including modifications by the addition of hexa(ethylene glycol), ß-cyclodextrin and macelignan were developed. All NPs-PTX formulations displayed excellent hemocompatibility and significantly enhanced PTX antitumor activity in human breast (MCF7, MDAMB231, SKBR3 and T47D) and lung (A549, NCI-H520 and NCI-H460) cancer cells. Tripalm-NPs-PTX decreased PTX IC50 by as much as 40.5-fold in breast and 38.8-fold in lung cancer cells and Tripalm-NPs-PTX macelignan inhibited P-glycoprotein in resistant tumor cells. In addition, Tripalm-NPs-PTX significantly decreased the volume of breast and lung multicellular tumor spheroids that mimics in vivo tumor mass. Finally, Tripalm-NPs-PTX decreased the PTX IC50 of cancer stem cells (CSCs) derived from both lung and breast cancer cells (6.7- and 14.9-fold for MCF7 and A549 CSCs, respectively). These results offer a new PTX nanoformulation based on the use of tripalmitin which improves the antitumor activity of PTX and that may serve as an alternative PTX delivery system in breast and lung cancer treatment.