Biology subjects

Chang, D. K.

Publications and source records attributed to Chang, D. K..

6 recordsLinked to original sources

bioRxiv2026

Morphospatial profiling of cancer-associated fibroblasts reveals architectural subtypes of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with an urgent need for biomarkers to predict prognosis and guide treatment. Understanding the complex spatial biology of pancreatic cancer-associated fibroblasts (CAFs) and the broader architecture of the PDAC tumour microenvironment is central to this challenge. Using a multi-omics approach across multiple spatial resolutions in a large human PDAC cohort, we integrate geometry and shape to define discrete morphological CAF subtypes, expanding CAF phenotyping beyond conventional proteomics. We then reveal an architectural and molecular axis of PDAC at tissue level, suggestive of epithelial-stromal co-evolution, with translational implications and prioritisation of stromal targets. Finally, we recapitulate this axis by introducing four unique, internally validated architectural subtypes of PDAC, each characterised by a common microenvironment and CAF enrichment profile. These archetypes outperform conventional pathology in prognostication, and predict response to adjuvant chemotherapy. Collectively, this study establishes a novel morphological paradigm for spatial biology, illuminates the architectural landscape of PDAC, and provides a framework for spatial biomarker discovery to close the translational gap in this devastating disease.

cancer biology↗

bioRxiv2025

IFN-gamma-Induced Intestinal Epithelial Cell-Type-Specific Programmed Cell Death: PANoptosis and Its Modulation in Crohn's Disease

Crohns disease (CD) is a chronic inflammatory bowel disease (IBD) and is considered a Th1-mediated disease, supported by the over-expression of interferon-gamma (IFN-{gamma}) in the intestinal lamina propria. To evaluate the response of intestinal epithelial cells (IECs) to IFN-{gamma}, we established small intestinal organoids (enteroids) derived from non-IBD controls and CD patients. IFN-{gamma} stimulated programmed cell death (PCD) of IECs in both control and CD enteroids in a dose-dependent manner. Pyroptosis, apoptosis and necroptosis were activated in enteroids, suggesting that PANoptosis was the main process of IFN-{gamma}-induced PCD in IECs. The response to IFN-{gamma} depends on the cell type of the IECs. IFN-{gamma} induced depletion of enterocytes with upregulation of PANoptosis-associated genes, while leading to expansion of goblet cells without significant change in PANoptosis-associated gene expression. Individual PCD inhibitors were insufficient to block IFN-{gamma}-induced cytotoxicity, whereas the selective JAK1 inhibitor (upadacitinib) effectively blocked IFN-{gamma}-induced cytotoxicity and PANoptosis. Furthermore, PANoptosis was significantly activated in surgically resected tissues and in publicly available single-cell RNA-sequencing datasets of intestinal tissues from patients with CD. In conclusion, IFN-{gamma} induces PANoptosis in enterocytes, which can be treated with a selective JAK1 inhibitor in patients with CD.

cell biology↗

bioRxiv2024

Sequential ATR and PARP Inhibition Overcomes Acquired DNA Damaging Agent Resistance in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains the most lethal cancer and will soon be the second most common cause of cancer related death. While regimens containing DNA damaging agents such as FOLFIRINOX and PARP inhibitors have derived clinical benefits for some patients, their efficacy invariably fails over time. This presents a significant clinical challenge, and thus there is an urgent need for novel therapeutic strategies which are able to overcome the acquisition of resistance in PDAC. Clinically relevant models of treatment resistance were generated from patient-derived cell lines by extended exposure to chemotherapy agents. Synergy scoring, clonogenicity assays, flow cytometry, immunofluorescence and transcriptomic analysis were used to investigate the efficacy of combined ATR and PARP inhibition in re-sensitising resistant PDAC to treatment. Acquisition of resistance was associated with transcriptomic shifts in cell cycle checkpoint regulation, metabolic control, DNA damage response (DDR), programmed cell death and the replication stress response. Additionally, combined treatment with the ATR inhibitor (ceralasertib), and the PARP inhibitor (olaparib) was synergistic in all models of acquired resistance. Sequential treatment using ceralasertib prior to olaparib was highly effective at low dose for DDR proficient cell lines, whereas DDR deficient models responded better when treated with olaparib first. We provide in vitro evidence of a novel therapeutic strategy to overcome acquired PARP inhibitor and platinum resistance in PDAC by using sequential exposure to ceralasertib and Olaparib. A sequential regimen may be more tolerable and should be investigated clinically to circumvent dose limiting toxicity in concurrent combinations.

cancer biology↗

bioRxiv2023

Kras loss of heterozygosity promotes MAPK dependent pancreatic ductal adenocarcinoma and induces therapeutic sensitivity

Pancreatic cancer is characterised by the prevalence of oncogenic mutations in KRAS. Previous studies have reported that altered Kras gene dosage drives progression and metastatic incidence in pancreatic cancer. While the role of oncogenic KRAS mutation is well characterised, the relevance of the partnering wild-type KRAS allele in pancreatic cancer is less well understood and controversial. Using in vivo mouse modelling of pancreatic cancer, we demonstrate that wild-type Kras restrains the oncogenic impact of mutant Kras, and drastically impacts both Kras-mediated tumourigenesis and therapeutic response. Mechanistically, deletion of wild-type Kras increases oncogenic Kras signalling through the downstream MAPK effector pathway, driving pancreatic intraepithelial neoplasia (PanIN) initiation. In addition, in the KPC mouse model, a more aggressive model of pancreatic cancer, loss of wild-type KRAS leads to accelerated initiation but delayed tumour progression. These tumours had altered stroma, downregulated Myc levels and an enrichment for immunogenic gene signatures. Importantly, loss of wild-type Kras sensitises Kras mutant tumours to MEK1/2 inhibition though tumours eventually become resistant and then rapidly progress. This study demonstrates the repressive role of wild-type Kras during pancreatic tumourigenesis and highlights the critical impact of the presence of wild-type KRAS on tumourigenesis and therapeutic response in pancreatic cancer.

cancer biology↗

bioRxiv2021

Epithelial Regeneration Ability of Crohn's Disease Assessed Using Patient-Derived Intestinal Organoids

BackgroundThe intrinsic limitation of cell lines and animal models limits our understanding of epithelial regeneration capability in Crohns disease (CD). Therefore, we aimed to study epithelial regeneration ability in CD using an intestinal organoid model. Further, since tumor necrosis factor alpha (TNF) is a major proinflammatory effector during CD pathogenesis, we also investigated TNF-induced alteration of regeneration ability in CD patient-derived intestinal organoids. MethodsHuman intestinal organoids were constructed in a three-dimensional intestinal crypt culture of enteroscopic biopsy samples from control subjects and patients with CD. The epithelial regeneration ability of intestinal organoids was assessed using organoid reconstitution, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), and wound healing assays. ResultsEx vivo cultures of ileal crypt cells revealed that organoid formation rate of CD patients were reduced compared with that of control subjects (p <.001). CD patient-derived organoids sub-cultured for more than 6 passages showed stable organoid reconstitution and identical morphological features. The organoid constitution and MTT assay revealed that the viability of TNF-treated CD patient-derived organoids were significantly lower than that of TNF-treated control organoids (p <.05 for each). The number of EdU+ proliferative cells was significantly lower in TNF-treated CD patient-derived organoids than in TNF-treated control organoids (p <.05). The wound-healing ability of TNF-treated CD patient-derived organoids was significantly lower than that of TNF-treated control organoids (p <.001). ConclusionsThe clinical trials are disabled to settle this issue, our results indicated that the epithelial regenerative ability is impaired in patients with CD, especially in TNF-enriched condition.

cell biology↗

bioRxiv2019

An unbiased high-throughput drug screen reveals a potential therapeutic vulnerability in the most lethal molecular subtype of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related deaths in the United States by 2020, due in part to innate resistance to widely used chemotherapeutic agents and limited knowledge about key molecular factors that drive tumor aggression. We previously reported a novel negative prognostic biomarker, keratin 17 (K17), whose overexpression in cancer results in shortened patient survival. In this study, we aimed to determine the predictive value of K17 and explore the therapeutic vulnerability in K17-expressing PDAC, using an unbiased high-throughput drug screen. Patient-derived data analysis showed that K17 expression correlates with resistance to Gemcitabine (Gem). In multiple in vitro models of PDAC, spanning human and murine PDAC cells, we determined that the expression of K17 results in a more than two-fold increase in resistance to Gem and 5-fluorouracil, key components of current standard-of-care chemotherapeutic regimens. Furthermore, through an unbiased drug screen, we discovered that Podophyllotoxin (PPT), a microtubule inhibitor, showed at least two-fold higher sensitivity in K17-expressing compared to K17-negative PDAC cells. In the clinic, another microtubule inhibitor, Paclitaxel (PTX), is used in combination with Gem as a first line chemotherapeutic regimen for pancreatic, breast, lung, and ovarian cancer. Surprisingly, we found that when combined with Gem, PPT but not PTX, was synergistic in inhibiting the viability of K17-expressing PDAC cells. This provides evidence that PPT or its derivatives could potentially be combined with Gem to enhance treatment efficacy for the approximately 50% of PDACs that express high levels of K17. In summary, we reported that K17 is a novel target for developing a biomarker-based personalized treatment for PDAC.

cancer biology↗