Serum Extracellular Vesicle Stratifin Is a Biomarker of Perineural Invasion in Patients With Colorectal Cancer and Predicts Worse Prognosis

14-3-3σ restricts YY1 to the cytoplasm, promoting therapy resistance, and tumor progression in colorectal cancer

14-3-3σ functions as an oncogene in colorectal cancer and is associated with therapy resistance. However, the mechanisms underlying these observations are not clear. The results in this report demonstrate that loss of 14-3-3σ in colorectal cancer cells leads to a decrease in tumor formation and increased sensitivity to chemotherapy. The increased sensitivity to chemotherapy is due to a decrease in the expression of UPR pathway genes in the absence of 14-3-3σ. 14-3-3σ promotes expression of the UPR pathway genes by binding to the transcription factor YY1 and preventing the nuclear localization of YY1. YY1, in the absence of 14-3-3σ, shows increased nuclear localization and binds to the promoter of the UPR pathway genes, resulting in decreased gene expression. Similarly, a YY1 mutant that cannot bind to 14-3-3σ also shows increased nuclear localization and is enriched on the promoter of the UPR pathway genes. Finally, inhibition of the UPR pathway with genetic or pharmacological approaches sensitizes colon cancer cells to chemotherapy. Our results identify a novel mechanism by which 14-3-3σ promotes tumor progression and therapy resistance in colorectal cancer by maintaining UPR gene expression.

Stratifin-mediated activation of AKT signaling and therapeutic targetability in hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and presents a significant threat to human health. Despite its prevalence, the underlying regulatory mechanisms of HCC remain unclear. In this study, we integrated RNA-seq datasets, proteome dataset and survival analysis and unveiled Stratifin (SFN) as a potential prognostic biomarker for HCC. SFN knockdown inhibited HCC progression in cell cultures and mouse models. Conversely, ectopic expression of Sfn in primary mouse HCC model accelerated HCC progression. Mechanistically, SFN acted as an adaptor protein, activating AKT1 signaling by fostering the interaction between PDK1 and AKT1, with the R56 and R129 sites on SFN proving to be crucial for this binding. In the syngeneic implantation model, the R56A/R129A mutant of SFN inhibited Akt signaling activation and impeded HCC growth. Additionally, peptide inhibitors designed based on the binding motif of AKT1 to SFN significantly inhibited HCC progression. In summary, our findings establish that SFN promotes HCC progression by activating AKT signaling through the R56 and R129 binding sites. This discovery opens new avenues for a promising therapeutic strategy for the treatment of HCC.

Proteomic Research of Extracellular Vesicles in Clinical Biofluid

Extracellular vesicles (EVs), the lipid bilayer membranous structures of particles, are produced and released from almost all cells, including eukaryotes and prokaryotes. The versatility of EVs has been investigated in various pathologies, including development, coagulation, inflammation, immune response modulation, and cell-cell communication. Proteomics technologies have revolutionized EV studies by enabling high-throughput analysis of their biomolecules to deliver comprehensive identification and quantification with rich structural information (PTMs, proteoforms). Extensive research has highlighted variations in EV cargo depending on vesicle size, origin, disease, and other features. This fact has sparked activities to use EVs for diagnosis and treatment to ultimately achieve clinical translation with recent endeavors summarized and critically reviewed in this publication. Notably, successful application and translation require a constant improvement of methods for sample preparation and analysis and their standardization, both of which are areas of active research. This review summarizes the characteristics, isolation, and identification approaches for EVs and the recent advances in EVs for clinical biofluid analysis to gain novel knowledge by employing proteomics. In addition, the current and predicted future challenges and technical barriers are also reviewed and discussed.

Perineural Invasion in Pancreatic Ductal Adenocarcinoma: From Molecules towards Drugs of Clinical Relevance

Pancreatic ductal adenocarcinoma is one of the most threatening solid malignancies. Molecular and cellular mediators that activate paracrine signalling also regulate the dynamic interaction between pancreatic cancer cells and nerves. This reciprocal interface leads to perineural invasion (PNI), defined as the ability of cancer cells to invade nerves, similar to vascular and lymphatic metastatic cascade. Targeting PNI in pancreatic cancer might help ameliorate prognosis and pain relief. In this review, the modern knowledge of PNI in pancreatic cancer has been analysed and critically presented. We focused on molecular pathways promoting cancer progression, with particular emphasis on neuropathic pain generation, and we reviewed the current knowledge of pharmacological inhibitors of the PNI axis. PNI represents a common hallmark of PDAC and correlates with recurrence, poor prognosis and pain in pancreatic cancer patients. The interaction among pancreatic cancer cells, immune cells and nerves is biologically relevant in each stage of the disease and stimulates great interest, but the real impact of the administration of novel agents in clinical practice is limited. It is still early days for PNI-targeted treatments, and further advanced studies are needed to understand whether they could be effective tools in the clinical setting.

Perineural invasion-associated biomarkers for tumor development

Perineural invasion (PNI) is the process of neoplastic invasion of peripheral nerves and is considered to be the fifth mode of cancer metastasis. PNI has been detected in head and neck tumors and pancreatic, prostate, bile duct, gastric, and colorectal cancers. It leads to poor prognostic outcomes and high local recurrence rates. Despite the increasing number of studies on PNI, targeted therapeutic modalities have not been proposed. The identification of PNI-related biomarkers would facilitate the non-invasive and early diagnosis of cancers, the establishment of prognostic panels, and the development of targeted therapeutic approaches. In this review, we compile information on the molecular mediators involved in PNI-associated cancers. The expression and prognostic significance of molecular mediators and their receptors in PNI-associated cancers are analyzed, and the possible mechanisms of action of these mediators in PNI are explored, as well as the association of cells in the microenvironment where PNI occurs.