Research Projects

The anti-cancer drug discovery and development pipeline is beset with a lot of challenges, with the entire process being inefficient and highly resource-, time- and labor-intensive. This inefficient process is partly attributed to the use of animal models as the gold standard for preclinical drug testing; however, these models are not only expensive and time-consuming but also raise ethical concerns and often fail to accurately predict human responses due to significant cross-species physiological differences. As a result, the USA FDA Modernization Act 2.0 encourages the development of novel methodologies, such as advanced in vitro assays and microphysiological systems as humanized platforms for preclinical studies. In cancers, one of the major reasons for drug failure is the inability of current simplistic in vitro models to capture the complexity and heterogeneity of the tumor extracellular matrix (tECM). It has been well established that the tECM significantly contributes to disease progression by imposing transport barriers on nutrients, metabolites, immune cells, and drug molecules, thereby imparting chemoresistance to the proliferating tumor mass. Current in vitro models, which rely on animal-derived flexible matrices and synthetic hydrogels, lack the complex and natural context of endogenous cell-governing ECM secretion; therefore, they fail to recapitulate tECM accurately. Synthetic biology, on the other hand, offers unique avenues for designing, constructing, and altering biological pathways to precisely control cell behavior and tissue organization. The primary objective of this proposal is to leverage synthetic biology principles for engineering mammalian cells to replicate the endogenous ECM synthesis mechanism, enabling the secretion and assembly formation of ECM components to capture the heterogeneity of tECM. Specifically, in pancreatic ductal adenocarcinoma (PDAC), the dense and fibrotic ECM creates a significant barrier to drug delivery, thereby hindering the killing of cancer cells, eventually leading to clinical failure of therapeutics. We hypothesize that ECM-secreting engineered cells will provide a novel and near-natural platform for accurately and rapidly mimicking different stages of PDAC, establishing humanized models to investigate drug transport and delivery. To this end, we propose the following aims: Aim 1: Design and construction of engineered cell lines to synthesize PDAC ECM. ECM components overexpressed in PDAC, e.g., collagen and hyaluronic acid, will be encoded in genetic circuits (Aim 1.1). These circuits will be integrated into the human fibroblast genome (Aim 1.2). Cells expressing different levels of ECM proteins will be sorted to generate cell populations that represent distinct stages of PDAC. Aim 2: ECM characterization to select cell lines that mimic early- and late-stage PDAC. The biophysical (Aim 2.1) and biochemical (Aim 2.2) characteristics of the ECM formed will be analyzed and compared to those of the PDAC patient tECM. Aim 3: Develop a drug delivery barrier assay using engineered ECM-secreting cells. We will demonstrate whether the secreted ECM creates a potential barrier for drug delivery by comparing the penetration ability of nanoparticles and/or free drug through different stages of PDAC (Aim 3.1). Finally, we will verify the cytotoxic effects of anticancer drugs transported through the PDAC ECM to target cancer cells (Aim 3.2). The use of synthetic biology to engineer ECM-secreting cells for disease modeling presents a novel paradigm, where each component of the system can be programmed and fine-tuned to accurately mimic in vivo disease state. We aim to eventually expand these ECM-secreting cell lines to capture a wide range of intra- and inter-tumor heterogeneous environments, which will enable rapid and high-throughput screening of drugs and drug carriers, ultimately advancing the drug development process.