The role of pancreatic and duodenal homeobox 1 as a therapeutic target in pancreatic cancer

Integrated multi-omics analyses reveal Jorunnamycin A as a novel suppressor for muscle-invasive bladder cancer by targeting FASN and TOP1

BACKGROUND

Bladder cancer is a urological carcinoma with high incidence, among which muscle invasive bladder cancer (MIBC) is a malignant carcinoma with high mortality. There is an urgent need to develop new drugs with low toxicity and high efficiency for MIBC because existing medication has defects, such as high toxicity, poor efficacy, and side effects. Jorunnamycin A (JorA), a natural marine compound, has been found to have a high efficiency anticancer effect, but its anticancer function and mechanism on bladder cancer have not been studied.

METHODS

To examine the anticancer effect of JorA on MIBC, Cell Counting Kit 8, EdU staining, and colony formation analyses were performed. Moreover, a xenograft mouse model was used to verify the anticancer effect in vivo. To investigate the pharmacological mechanism of JorA, high-throughput quantitative proteomics, transcriptomics, RT-qPCR, western blotting, immunofluorescence staining, flow cytometry, pulldown assays, and molecular docking were performed.

RESULTS

JorA inhibited the proliferation of MIBC cells, and the IC50 of T24 and UM-UC-3 was 0.054 and 0.084 μM, respectively. JorA-induced significantly changed proteins were enriched in "cancer-related pathways" and "EGFR-related signaling pathways", which mainly manifested by inhibiting cell proliferation and promoting cell apoptosis. Specifically, JorA dampened the DNA synthesis rate, induced phosphatidylserine eversion, and inhibited cell migration. Furthermore, it was discovered that fatty acid synthase (FASN) and topoisomerase 1 (TOP1) are the JorA interaction proteins. Using DockThor software, the 3D docking structures of JorA binding to FASN and TOP1 were obtained (the binding affinities were - 8.153 and - 7.264 kcal/mol, respectively).

CONCLUSIONS

The marine compound JorA was discovered to have a specific inhibitory effect on MIBC, and its potential pharmacological mechanism was revealed for the first time. This discovery makes an important contribution to the development of new high efficiency and low toxicity drugs for bladder cancer therapy.

Pancreatic Lineage Specifier PDX1 Increases Adhesion and Decreases Motility of Cancer Cells

Intercellular interactions involving adhesion factors are key operators in cancer progression. In particular, these factors are responsible for facilitating cell migration and metastasis. Strengthening of adhesion between tumor cells and surrounding cells or extracellular matrix (ECM), may provide a way to inhibit tumor cell migration. Recently, we demonstrated that PDX1 ectopic expression results in the reduction of pancreatic cancer line PANC-1 cell motility in vitro and in vivo, and we now provide experimental data confirming the hypothesis that suppression of migration may be related to the effect of PDX1 on cell adhesion. Cell migration analyses demonstrated decreased motility of pancreatic Colo357 and PANC-1 cell lines expressing PDX1. We observed decreased expression levels of genes associated with promoting cell migration and increased expression of genes negatively affecting cell motility. Expression of the EMT regulator genes was only mildly induced in cells expressing PDX1 during the simulation of the epithelial-mesenchymal transition (EMT) by the addition of TGFβ1 to the medium. PDX1-expressing cancer cell lines showed increased cell adhesion to collagen type I, fibronectin, and poly-lysine. We conclude that ectopic expression of PDX1 reduces the migration potential of cancer cells, by increasing the adhesive properties of cells and reducing the sensitivity to TGFβ1-induced EMT.

The role of lineage specifiers in pancreatic ductal adenocarcinoma

Over the last decade, multiple genomics studies have led to the identification of discrete molecular subtypes of pancreatic ductal adenocarcinoma. A general theme has emerged that most pancreatic ductal adenocarcinoma (PDAC) can be grouped into two major subtypes based on cancer cell autonomous properties: classical/pancreatic progenitor and basal-like/squamous. The classical/progenitor subtype expresses higher levels of lineage specifiers that regulate endodermal differentiation than the basal-like/squamous subtype. The basal-like/squamous subtype confers a worse prognosis, raising the possibility that loss of these lineage specifiers might enhance the malignant potential of PDAC. Here, we discuss several of these differentially expressed lineage specifiers and examine the evidence that they might play a functional role in PDAC biology.

Establishment of a human primary pancreatic cancer mouse model to examine and investigate gemcitabine resistance

Pancreatic cancer is one of the most fatal types of cancer and is associated with a dismal prognosis. Gemcitabine-based chemotherapy is clinically used for the treatment of advanced pancreatic cancer. However, many forms of pancreatic cancer have acquired resistance to gemcitabine. In order to prevent patients from suffering from the side effects of chemotherapy and to have the chance to receive more effective intervention, assessment of whether the patient pancreatic cancer cells are resistant to gemcitabine before clinical practice is crucial. Recently, patient-derived xenograft (PDX) models have been regarded as a practical approach for preclinical drug resistance test. In the present study, we harvested tumor specimens from 28 pancreatic cancer patients to establish PDX models. The tumor formation rate of the xenografts was 100%, several of which could be re-implanted in nude mice for more than 10 passages. Primary cells were further obtained from the PDX xenografts to determine their morphological features and evaluate their proliferation rate, migration capacity and angiopoietic ability. In addition, the sensitivities of the primary cells and PDX xenografts to gemcitabine were correlated with each other. When compared to the gemcitabine-sensitive cells, the gemcitabine-resistant cells had a higher level of MCF2L expression, suggesting that MCF2L plays an important role in gemcitabine resistance.

Small cell lung cancer: Circulating tumor cells of extended stage patients express a mesenchymal-epithelial transition phenotype

Small cell lung cancer (SCLC) is distinguished by aggressive growth, early dissemination and a poor prognosis at advanced stage. The remarkably high count of circulating tumor cells (CTCs) of SCLC allowed for the establishment of permanent CTC cultures at our institution for the first time. CTCs are assumed to have characteristics of cancer stem cells (CSCs) and an epithelial-mesenchymal transition (EMT) phenotype, but extravasation of tumors at distal sites is marked by epithelial features. Two SCLC CTC cell lines, namely BHGc7 and BHGc10, as well as SCLC cell lines derived from primary tumors and metastases were analyzed for the expression of pluripotent stem cell markers and growth factors. Expression of E-cadherin and β-Catenin were determined by flow cytometry. Stem cell-associated markers SOX17, α-fetoprotein, OCT-3/4, KDR, Otx2, GATA-4, Nanog, HCG, TP63 and Goosecoid were not expressed in the 2 CTC lines. In contrast, high expression was found for HNF-3β/FOXA2, SOX2, PDX-1/IPF1 and E-cadherin. E-cadherin expression was restricted to the 2 CTCs and 2 cell lines derived from pleural effusion (SCLC26A) and bone metastases (NCI-H526), respectively. Thus, these SCLC CTCs established from extended disease SCLC patients lack expression of stem cell markers which suppress the epithelial phenotype. Instead they express high levels of E-cadherin consistent with a mesenchymal-epithelial transition (MET or EMrT) and form large tumorospheres possibly in response to the selection pressure of first-line chemotherapy. HNF-3β/FOXA2 and PDX-1/IPF1 expression seem to be related to growth factor dependence on insulin/IGF-1 receptors and IGF-binding proteins.