Identification of key pathways and gene changes in primary pancreatic stellate cells after cross-talk with pancreatic cancer cells (BXPC-3) using bioinformatics analysis

Probing the Potential of Defense Response-Associated Genes for Predicting the Progression, Prognosis, and Immune Microenvironment of Osteosarcoma

BACKGROUND

The defense response is a type of self-protective response of the body that protects it from damage by pathogenic factors. Although these reactions make important contributions to the occurrence and development of tumors, the role they play in osteosarcoma (OS), particularly in the immune microenvironment, remains unpredictable.

METHODS

This study included the clinical information and transcriptomic data of 84 osteosarcoma samples and the microarray data of 12 mesenchymal stem cell samples and 84 osteosarcoma samples. We obtained 129 differentially expressed genes related to the defense response (DRGs) by taking the intersection of differentially expressed genes with genes involved in the defense response pathway, and prognostic genes were screened using univariate Cox regression. Least absolute shrinkage and selection operator (LASSO) penalized Cox regression and multivariate Cox regression were then used to establish a DRG prognostic signature (DGPS) via the stepwise method. DGPS performance was examined using independent prognostic analysis, survival curves, and receiver operating characteristic (ROC) curves. In addition, the molecular and immune mechanisms of adverse prognosis in high-risk populations identified by DGPS were elucidated. The results were well verified by experiments.

RESULT

BNIP3, PTGIS, and ZYX were identified as the most important DRGs for OS progression (hazard ratios of 2.044, 1.485, and 0.189, respectively). DGPS demonstrated outstanding performance in the prediction of OS prognosis (area under the curve (AUC) values of 0.842 and 0.787 in the training and test sets, respectively, adj-p < 0.05 in the survival curve). DGPS also performed better than a recent clinical prognostic approach with an AUC value of only 0.674 [metastasis], which was certified in the subsequent experimental results. These three genes regulate several key biological processes, including immune receptor activity and T cell activation, and they also reduce the infiltration of some immune cells, such as B cells, CD8+ T cells, and macrophages. Encouragingly, we found that DGPS was associated with sensitivity to chemotherapeutic drugs including JNK Inhibitor VIII, TGX221, MP470, and SB52334. Finally, we verified the effect of BNIP3 on apoptosis, proliferation, and migration of osteosarcoma cells through experiments.

CONCLUSIONS

This study elucidated the role and mechanism of BNIP3, PTGIS, and ZYX in OS progression and was well verified by the experimental results, enabling reliable prognostic means and treatment strategies to be proposed for OS patients.

The Role of Stellate Cells in Pancreatic Ductal Adenocarcinoma: Targeting Perspectives

Pancreatic ductal adenocarcinoma (PDAC) is a gastrointestinal malignancy with a dismal clinical outcome. Accumulating evidence suggests that activated pancreatic stellate cells (PSCs), the major producers of extracellular matrix (ECM), drive the severe stromal/desmoplastic reaction in PDAC. Furthermore, the crosstalk among PSCs, pancreatic cancer cells (PCCs) as well as other stroma cells can establish a growth-supportive tumor microenvironment (TME) of PDAC, thereby enhancing tumor growth, metastasis, and chemoresistance via various pathways. Recently, targeting stroma has emerged as a promising strategy for PDAC therapy, and several novel strategies have been proposed. The aim of our study is to give a profound review of the role of PSCs in PDAC progression and recent advances in stroma-targeting strategies.

Efficient Gene Therapy of Pancreatic Cancer via a Peptide Nucleic Acid (PNA)-Loaded Layered Double Hydroxides (LDH) Nanoplatform

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignant tumors with extremely poor prognosis due to the later stage diagnosis when surgical resection is no longer applicable. Alternatively, the traditional gene therapy which drives pancreatic cancer cells into an inactive state and inhibiting the proliferation and metastasis, presents potentials to safely inhibit pancreatic cancer progression, but unfortunately has received limited success to date. Here, an efficient gene therapy of pancreatic cancer is shown via a peptide nucleic acid (PNA)-loaded layered double hydroxides (LDHs) nanoplatform. Compared with the traditional DNA- or RNA-based gene therapies, the gene therapy using PNA features great advantages in recognizing and hybridizing with the target mutant sequences to form PNA-DNA hybrids with significantly enhanced stability due to the absence of electrostatic repulsion, and the constrained flexibility of the polyamide backbone. Moreover, ultrasmall LDHs are engineered to load PNA and the obtained PNA-loaded LDH platform (LDHs/PNA) is capable of efficiently and selectively targeting the intranuclear mutant sequences thanks to the proton sponge effect. Treatments with LDHs/PNA demonstrate markedly inhibited growth of pancreatic cancer xenografts via a cancer cell proliferation suppression mechanism. The results demonstrate the great potentials of LDHs/PNA as a highly promising gene therapy agent for PDAC.

NGF from pancreatic stellate cells induces pancreatic cancer proliferation and invasion by PI3K/AKT/GSK signal pathway

Pancreatic cancer (PC) is a continuously high lethal disease, and the tumour microenvironment plays a pivotal role during PC progression. Herein, we focus on that the Nerve growth factor (NGF)/Tropomyosin-related kinase A (TrkA), in pancreatic stellate cells-pancreatic cancer cells (PSCs-PC cells) co-culture system, influences PC proliferation and invasion. The model of PC cells and PSCs was directly co-cultured in a no-touch manner, using the Transwell as the co-culture system. NGF and TrkA expression was measured in cultured system by real-time PCR, immunofluorescence, Western blotting analysis or ELISA. Small interfering RNA transfection was used to regulate the expression of TrkA in PC cells. The promotion of cancer invasion was investigated using Matrigel Transwell assay. In our study, NGF/TrkA is overexpressed in PSCs-PC cells co-culture system and promotes the invasion and proliferation of PC cells. And the epithelial-mesenchymal transition-related genes are influenced by si-TrkA. What's more, NGF/TrkA regulates the PC cell proliferation and invasion via activation of PI3K/AKT/GSK signalling. The present study demonstrated NGF/TrkA promoted the PC cell proliferation and invasion in the co-culture system by the activation of the PI3K/AKT/GSK signal cascade, providing a potential therapeutic target for PC patients.