Unfolded protein response signature unveils novel insights into breast cancer prognosis and tumor microenvironment.

BACKGROUND: The critical role of the unfolded protein response (UPR) in tumorigenesis is widely acknowledged, yet the precise molecular mechanisms underlying its contribution to breast cancer (BC) have not been fully elucidated. The present study aimed to comprehensively explore the expression characteristics and prognostic significance of UPR-related genes in breast cancer METHODS: The transcriptome and clinical data of breast cancer were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, respectively. Differential expression analysis was conducted on UPR-related genes, and the resulting genes were employed for consensus clustering analysis. A breast cancer prognosis risk model was constructed using univariate, least absolute shrinkage and selection operator (LASSO), and multivariable Cox regression analyses. Difference in survival outcomes between groups were analyzed Kaplan-Meier survival analysis, and receiver operating characteristic (ROC) curve was used to assess predictive performance. The relationship between the risk model and clinical-pathological characteristics, immune infiltration, immunotherapy response, and drug sensitivity was assessed. RESULTS: Differential expression analysis identified 10 UPR-related genes that were differentially expressed in breast cancer. Using the expression matrix of these genes, two molecular subtypes of breast cancer were characterized, which displayed significant differences in prognostic and immune infiltration characteristics. Drawing from the gene expression profiles that distinguish between the molecular subtypes, a prognostic risk scoring model comprising eight genes was developed. This model stratified BC patients from both the training and validation cohorts into high-risk and low-risk groups. Patients in the low-risk group had better prognoses, while those with advanced clinical stage and T stage exhibited higher risk scores. The high- and low-risk groups exhibited notable disparities in immune cell infiltration and the expression of multiple immune checkpoint-related genes. Additionally, the low-risk group demonstrated elevated immunophenoscore, Merck18, CD274, and CAF scores compared to the high-risk group, along with a lesser sensitivity to chemotherapy drugs. These results suggest that patients within the low-risk group may potentially benefit more from immunotherapy and chemotherapy interventions. CONCLUSIONS: This study developed a novel UPR-derived risk signature, which could robustly predict the survival outcome, immune microenvironment, and chemotherapy response of patients with breast cancer.

Emodin Promotes Apoptosis of Human Endometrial Cancer Through Regulating the MAPK and PI3K/ AKT Pathways.

Emodin, a major component of rhubarb, has anti-tumor effects in a variety of cancers, influencing multiple steps of tumor development through modulating several signaling pathways. The aim of this study is to examine the effect of emodin on cell apoptosis and explore the underlying mechanisms in human endometrial cancer cells. Here we report that emodin can inhibit KLE cell proliferation and induce apoptosis in a time- and dose-dependent manner. Western blot assay found that emodin was involved in MAPK and PI3K/Akt signaling pathways. Specifically, emodin significantly suppressed the phosphorylation of AKT, and enhanced the phosphorylation of MAPK pathways. Furthermore, the generation of reactive oxygen species (ROS) was up-regulated in KLE cells upon treatment with emodin, while the anti-oxidant agent N-acetyl cysteine (NAC) can inhibit emodin-induced apoptosis and promote the activation of AKT and Bcl-2. Taken together, we revealed that emodin may induce apoptosis in KLE cells through regulating the PI3K/AKT and MAPK signaling pathways, indicating the importance of emodin as an anti-tumor agent.

Cryptotanshinone inhibits VEGF-induced angiogenesis by targeting the VEGFR2 signaling pathway.

OBJECTIVE: Anti-angiogenesis has been proposed as an important strategy for angiogenesis-related diseases. Cryptotanshinone (CPT), an active component of Salvia miltiorrhiza, may be a potential inhibitor of angiogenesis. However, the molecular mechanisms underlying its anti-angiogenic activities remain poorly understood. This study is to investigate the effects of CPT on VEGF-induced angiogenesis and VEGFR2 signaling pathway in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with different concentration of CPT (5-20µmol/L) and the viability, endothelial cell migration, invasion, and tubular-like structure formation of HUVECs were detected by MTT, wound-healing migration, Transwell invasion and Matrigel tube formation assays, respectively. To assess the effect of CPT on VEGFR2 signaling pathway, VEGF-induced phosphorylation of VEGFR2 and its downstream molecules, including ERK1/2, p90RSK, Src and FAK were analyzed by Western blot. RESULTS: CPT significantly suppressed VEGF-induced cells proliferation, migration, invasion, and tubular-like structure formation in HUVECs in a dose- and time-dependent manner. Western blot results revealed that CPT significantly suppressed VEGF-induced phosphorylation of VEGFR2 and its key downstream protein kinases, including p-ERK1/2, p-p90RSK, pY416-Src and pY576/577-FAK, which are responsible for endothelial cell migration, proliferation, and survival. CONCLUSION: Our study suggested that CPT potently inhibits VEGF-induced angiogenesis by suppressing VEGFR2 activation and its downstream Src/FAK and ERK1/2 signaling pathways in HUVECs, highlighting the therapeutic potential for the treatment of angiogenesis-related diseases.