Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease, and its incidence is increasing annually. It is critical to reveal and delineate the molecular mechanism promoting PDAC development and progression. Mammalian STE20-like kinase 1 (MST1) is a proapoptotic cytoplasmic kinase and also one of the core components of the Hippo pathway. Here, we showed that MST1 expression was decreased in PDAC, and restored expression of MST1 promoted PDAC cell death and suppressed the proliferation, migration, invasion, and cell spheroid formation of PDAC via caspase-1–induced pyroptosis. Further studies demonstrated that pyroptosis induced by MST1 was independent of the Hippo pathway, but mediated by reactive oxygen species (ROS). And ROS scavenger N-acetyl-cysteine attenuated the activation of caspase-1 induced by MST1 and the effect of MST1 in PDAC cell death, proliferation, migration, and invasion. Collectively, our study demonstrated that MST1 suppressed the progression of PDAC cells at least partly through ROS-induced pyroptosis. Implications: In this study, we identified a new mechanism of MST1 in inhibiting PDAC development and progression and revealed that MST1 would be a potential prognostic and therapeutic target for PDAC.
Our previous research defined a novel metabolic cancer associated fibroblasts subset (meCAFs) enriched in loose-type pancreatic ductal adenocarcinoma (PDAC) and related to CD8+ T cells accumulation. Consistently, the abundance of meCAFs was associated with poor prognosis but better immunotherapy responses in PDAC patients. However, the metabolic characteristic of meCAFs and its cross-talk with CD8+ T cells remain to be elucidated. In this study, we identified PLA2G2A as a marker of meCAFs. In particular, the abundance of PLA2G2A+ meCAFs was positively related to the accumulation of total CD8+ T cells and negatively correlated with clinical outcomes of PDAC patients and infiltration of intratumoral CD8+ T cells. We demonstrated that PLA2G2A+ meCAFs substantially attenuated the antitumor ability of tumor infiltrating CD8+ T cells and facilitated tumor immune escape in PDAC. Mechanistically, PLA2G2A regulated the function of CD8+ T cells as a pivotal soluble mediator via MAPK/Erk and NF-κB signaling pathways. In conclusion, our study identified the unrecognized role of PLA2G2A+ meCAFs in promoting tumor immune escape by impeding the antitumor immune function of CD8+ T cells, and strongly suggested PLA2G2A as a promising biomarker and therapeutic target for immunotherapy in PDAC.
Background: Pancreatic adenocarcinoma (PC) is an aggressive malignancy with limited treatment options. The poor prognosis primarily stems from late-stage diagnosis and when the disease has become therapeutically challenging. There is an urgent need to identify specific biomarkers for cancer subtyping and early detection to enhance both morbidity and mortality outcomes. The addition of the EGFR tyrosine kinase inhibitor (TKI), erlotinib, to gemcitabine chemotherapy for the first-line treatment of patients with advanced pancreatic cancer slightly improved outcomes. However, restricted clinical benefits may be linked to the absence of well-characterized criteria for stratification and dependable biomarkers for the prediction of treatment effectiveness. Methods and results: We examined the levels of various cancer hallmarks and identified glycolysis as the primary risk factor for overall survival in PC. Subsequently, we developed a glycolysis-related score (GRS) model to accurately distinguish PC patients with high GRS. Through in silico screening of 4398 compounds, we discovered that erlotinib had the strongest therapeutic benefits for high-GRS PC patients. Furthermore, we identified ARNTL2 as a novel prognostic biomarker and a predictive factor for erlotinib treatment responsiveness in patients with PC. Inhibition of ARNTL2 expression reduced the therapeutic efficacy, whereas increased expression of ARNTL2 improved PC cell sensitivity to erlotinib. Validation in vivo using patient-derived xenografts (PDX-PC) with varying ARNTL2 expression levels demonstrated that erlotinib monotherapy effectively halted tumor progression in PDX-PC models with high ARNTL2 expression. In contrast, PDX-PC models lacking ARNTL2 did not respond favorably to erlotinib treatment. Mechanistically, we demonstrated that the ARNTL2/E2F1 axis-mediated cellular glycolysis sensitizes PC cells to erlotinib treatment by activating the PI3K/AKT signaling pathway. Conclusions: Our investigations have identified ARNTL2 as a novel prognostic biomarker and predictive indicator of sensitivity. These results will help to identify erlotinib-responsive cases of PC and improve treatment outcomes. These findings contribute to the advancement of precision oncology, enabling more accurate and targeted therapeutic interventions.
It was demonstrated that long non-coding RNAs occupied an important position in tumor pathogenesis and progression. We have previously found that the metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) promotes cell proliferation and metastases in pancreatic ductal adenocarcinoma (PDAC). The present study was aimed to discuss the underlying mechanisms. Bioinformatics method was used to identify the miRNA target of MALAT-1. Expressions of relative genes were assessed by quantitative real-time PCR and western blotting, respectively. Sulforhodamine B assay and Transwell assay were employed to detect cell proliferation, migration and invasion, respectively. Moreover, RNA immunoprecipitation was performed to determine whether RNA-induced silencing complex contained MALAT-1 and its potential binding miRNA. Luciferase assays was used to confirm potential binding site. Bioinformatics search predicted that miR-200c-3p was a direct target of MALAT-1. Further, we found a reciprocal suppression between MALAT-1 and miR-200c-3p expression. In terms of mechanisms, high MALAT-1 and low miR-200c-3p may form a novel feedback loop. On the one hand, MALAT-1 functioned as a competing endogenous RNA to suppress miR-200c-3p expression, leading to upregulation of ZEB1 expression. On the other hand, miR-200c-3p inhibited the level of MALAT-1 expression was in a way similar to miRNA-mediated downregulation of target genes. Clinical data further indicated that MALAT-1 and ZEB1 expression was negatively correlated with miR-200c-3p transcript level of PDAC tissues. There was a positive correlation between MALAT-1 and ZEB1 level. MALAT-1 (high)/miR-200c-3p (low) correlated with shorter overall survival of PDAC patients. Multivariate analysis revealed that both MALAT-1 and miR-200c-3p levels were independent prognostic factors. Our findings firstly revealed a novel feedback loop between high MALAT-1 and low miR-200c-3p. Targeting the feedback loop between high MALAT-1 and low miR-200c-3p will be a therapeutic strategy for PDAC.
23 August 2022 in Journal of the National Cancer Center
Pancreatic cancer is one of the leading causes of cancer-related mortality in both developed and developing countries. The incidence of pancreatic cancer in China accounts for about a quater of the global incidence, and the epidemiological characteristics and therapeutic strategies differ due to social, economic, cultural, environmental, and public health factors. Non-domestic guidelines do not reflect the clinicopathologic characteristics and treatment patterns of Chinese patients. Thus, in 2018, the Chinese Society of Clinical Oncology (CSCO) organized a panel of senior experts from all sub-specialties within the field of pancreatic oncology to compile the Chinese guidelines for the diagnosis and treatment of pancreatic cancer. The guidelines were made based on both the Western and Eastern clinical evidence and updated every one or two years. The experts made consensus judgments and classified evidence-based recommendations into various grades according to the regional differences, the accessibility of diagnostic and treatment resources, and health economic indexes in China. Here we present the latest version of the guidelines, which covers the diagnosis, treatment, and follow-up of pancreatic cancer. The guidelines might standardize the diagnosis and treatment of pancreatic cancer in China and will encourage oncologists to design and conduct more clinical trials about pancreatic cancer.
The nervous system governs both ontogeny and oncology. Foundational discoveries have clarified the direct communication of neurotransmitters with tumors and indirect interactions through neural effects on the immune system and the tumor microenvironment. Meantime, the nervous system is susceptible to cancer and its treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is the most common side effects that significantly reduce the efficacy of anti-cancer treatment and patients' quality of life by leading to dose reduction or early cessation of chemotherapy. However, there are no effective strategies to reverse or treat CIPN. A better understanding of the mechanisms is expected to enable the development of the next generation of therapies. Here, we summarize the recent important studies on clinical manifestations, risk factors, prediction, pathogenesis, prevention, and treatment of CIPN. We also provide perspectives and insights regarding the rationales of bidirectional interactions between cancer and the nervous system.