TIMP1 derived from pancreatic cancer cells stimulates Schwann cells and promotes the occurrence of perineural invasion

Nerve-tumor crosstalk in tumor microenvironment: From tumor initiation and progression to clinical implications

The autonomic nerve system (ANS) innervates organs and tissues throughout the body and maintains functional balance among various systems. Further investigations have shown that excessive activation of ANS not only causes disruption of homeostasis, but also may promote tumor formation. In addition, the dynamic interaction between nerve and tumor cells in the tumor microenvironment also regulate tumor progression. On the one hand, nerves are passively invaded by tumor cells, that is, perineural invasion (PNI). On the other hand, compared with normal tissues, tumor tissues are subject to more abundant innervation, and nerves can influence tumor progression through regulating tumor proliferation, metastasis and drug resistance. A large number of studies have shown that nerve-tumor crosstalk, including PNI and innervation, is closely related to the prognosis of patients, and contributes to the formation of cancer pain, which significantly deteriorates the quality of life for patients. These findings suggest that nerve-tumor crosstalk represents a potential target for anti-tumor therapies and the management of cancer pain in the future. In this review, we systematically describe the mechanism by which nerve-tumor crosstalk regulates tumorigenesis and progression.

Neuronal CFL1 upregulation in head and neck squamous cell carcinoma enhances tumor-nerve crosstalk and promotes tumor growth

Head and neck squamous cell carcinoma (HNSCC) is a prevalent cancer type, marked by a pronounced nerve density within the tumor microenvironment and a high rate of perineural invasion (PNI). Growing evidence suggests that the nervous system plays a vital role in HNSCC progression. Yet, the mechanisms governing cancer-nerve interactions remain largely elusive. Our research revealed that cofilin-1 (CFL1) is significantly overexpressed in HNSCC and correlates with both PNI and unfavorable prognosis. Utilizing multiplex fluorescent immunohistochemistry, we have localized CFL1 chiefly to the nerves adjacent to tumor sites. Significantly, it is the elevated expression of CFL1 in neuronal structures, rather than in the tumor cells, that aligns with diminished patient survival rates. We observed that HNSCC cells induced the expression of neuronal CFL1 and that the conditional knockout of neuronal CFL1 impedes tumor-nerve interactions. Both Gene Ontology functional enrichment analyses and Gene Set Enrichment Analysis demonstrate that CFL1 expression in HNSCC is associated with specific biological processes, including "RIBOSOME," "PROTEASOME," and "cadherin binding." In summary, HNSCC promotes the expression of CFL1 in nerves, which is essential for cancer-nerve interactions. The neuronal CFL1 is associated with PNI and may be a potential molecular prognostic marker of poor survival in HNSCC.

Schwann cells in pancreatic cancer: Unraveling their multifaceted roles in tumorigenesis and neural interactions

Pancreatic ductal adenocarcinoma (PDAC), characterized by heightened neural density, presents a challenging prognosis primarily due to perineural invasion. Recognized for their crucial roles in neural support and myelination, Schwann cells (SCs) significantly influence the process of tumorigenesis. This review succinctly outlines the interplay between PDAC and neural systems, positioning SCs as a nexus in the tumor-neural interface. Subsequently, it delves into the cellular origin and influencers of SCs within the pancreatic tumor microenvironment, emphasizing their multifaceted roles in tumor initiation, progression, and modulation of the neural and immune microenvironment. The discussion encompasses potential therapeutic interventions targeting SCs. Lastly, the review underscores pressing issues, advocating for sustained exploration into the diverse contributions of SCs within the intricate landscape of PDAC, with the aim of enhancing our understanding of their involvement in this complex malignancy.

Periampullary cancer and neurological interactions: current understanding and future research directions

Periampullary cancer is a malignant tumor occurring around the ampullary region of the liver and pancreas, encompassing a variety of tissue types and sharing numerous biological characteristics, including interactions with the nervous system. The nervous system plays a crucial role in regulating organ development, maintaining physiological equilibrium, and ensuring life process plasticity, a role that is equally pivotal in oncology. Investigations into nerve-tumor interactions have unveiled their key part in controlling cancer progression, inhibiting anti-tumor immune responses, facilitating invasion and metastasis, and triggering neuropathic pain. Despite many mechanisms by which nerve fibers contribute to cancer advancement still being incompletely understood, the growing emphasis on the significance of nerves within the tumor microenvironment in recent years has set the stage for the development of groundbreaking therapies. This includes combining current neuroactive medications with established therapeutic protocols. This review centers on the mechanisms of Periampullary cancer's interactions with nerves, the influence of various types of nerve innervation on cancer evolution, and outlines the horizons for ongoing and forthcoming research.

Tumour-associated macrophages and Schwann cells promote perineural invasion via paracrine loop in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is frequently accompanied by perineural invasion (PNI), which is associated with excruciating neuropathic pain and malignant progression. However, the relationship between PNI and tumour stromal cells has not been clarified.

METHODS

The dorsal root ganglia or sciatic nerves nerve model was used to observe the paracrine interaction and the activation effect among Schwann cells, tumour-associated macrophages (TAMs), and pancreatic cancer cells in vitro. Next generation sequencing, enzyme-linked immunosorbent assay and chromatin immunoprecipitation were used to explore the specific paracrine signalling between TAMs and Schwann cells.

RESULTS

We demonstrated that more macrophages were expressed around nerves that have been infiltrated by pancreatic cancer cells compared with normal nerves in murine and human PNI specimens. In addition, high expression of CD68 or GFAP is associated with an increased incidence of PNI and indicates a poor 5-year survival rate in patients with PDAC. Mechanistically, tumour-associated macrophages (TAMs) activate Schwann cells via the bFGF/PI3K/Akt/c-myc/GFAP pathway. Schwann cells secrete IL-33 to recruit macrophages into the perineural milieu and facilitate the M2 pro-tumourigenic polarisation of macrophages.

CONCLUSIONS

Our study demonstrates that the bFGF/IL-33 positive feedback loop between Schwann cells and TAMs is essential in the process of PNI of PDAC. The bFGF/PI3K/Akt/c-myc/GFAP pathway would open potential avenues for targeted therapy of PDAC.

Identification and validation of prognostic genes and immune landscape signatures based on a fatty acid oxidation‑related risk score model in glioma

Fatty acid oxidation (FAO) plays a crucial role in glioma metabolism and its interaction with the immune microenvironment. The aim of the present study was to investigate the relationship between FAO-related genes and glioma by constructing gene clusters using a glioma cohort. A total of 287 differentially expressed genes related to FAO were identified and the top 50 genes were selected based on their P-values. Subsequently, patients were classified into two distinct gene subtypes (A and B) based on these genes. Scores for each patient were calculated using the 50 genes and the patients were divided into the high and low-score groups accordingly. Patients in subtype B exhibited higher tumor grades and poor prognostic factors such as older age and worse survival rates. The high-score subgroup had unfavorable indicators, including isocitrate dehydrogenase 1 wild-type, high tumor grade and 1p19q non-codeleted, while immune checkpoint expression was generally higher in the high-score subgroup. The constructed scoring model was validated using an external dataset, and the tissue inhibitor of metalloproteinase 1 gene was identified through protein interaction analysis, suggesting its potential involvement in glioma malignancy and promotion of glioblastoma proliferation. In conclusion, FAO-related genes may contribute to tumor development through immune mechanisms and the present study may provide novel insights for potential therapeutic strategies in glioma treatment.

Ultrasound-Targeted Microbubble Destruction Assisted Delivery of Platelet-Rich Plasma-Derived Exosomes Promoting Peripheral Nerve Regeneration

Peripheral nerve injury is prevalent and has a high disability rate in clinical settings. Current therapeutic methods have not achieved satisfactory efficacy, underscoring the need for novel approaches to nerve restoration that remains an active area of research in neuroscience and regenerative medicine. In this study, we isolated platelet-rich plasma-derived exosomes (PRP-exos) and found that they can significantly enhance the proliferation, migration, and secretion of trophic factors by Schwann cells (SCs). In addition, there were marked changes in transcriptional and expression profiles of SCs, particularly via the upregulation of genes related to biological functions involved in nerve regeneration and repair. In the rat model of sciatic nerve crush injury, ultrasound-targeted microbubble destruction (UTMD) enhanced the efficiency of PRP-exos delivery to the injury site. This approach ensured a high concentration of PRP-exos in the injured nerve and improved the therapeutic outcomes. In conclusion, PRP-exos may promote nerve regeneration and repair, and UTMD may increase the effectiveness of targeted PRP-exos delivery to the injured nerve and enhance the therapeutic effect.

Crosstalk Between Peripheral Innervation and Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy, characterized by late diagnosis, aggressive growth, and therapy resistance, leading to a poor overall prognosis. Emerging evidence shows that the peripheral nerve is an important non-tumor component in the tumor microenvironment that regulates tumor growth and immune escape. The crosstalk between the neuronal system and PDAC has become a hot research topic that may provide novel mechanisms underlying tumor progression and further uncover promising therapeutic targets. In this review, we highlight the mechanisms of perineural invasion and the role of various types of tumor innervation in the progression of PDAC, summarize the potential signaling pathways modulating the neuronal-cancer interaction, and discuss the current and future therapeutic possibilities for this condition.

Biological characteristics of pancreatic ductal adenocarcinoma: Initiation to malignancy, intracellular to extracellular

Pancreatic ductal adenocarcinoma (PDAC) is a highly life-threatening tumour with a low early-detection rate, rapid progression and a tendency to develop resistance to chemotherapy. Therefore, understanding the regulatory mechanisms underlying the initiation, development and metastasis of pancreatic cancer is necessary for enhancing therapeutic effectiveness. In this review, we summarised single-gene mutations (including KRAS, CDKN2A, TP53, SMAD4 and some other less prevalent mutations), epigenetic changes (including DNA methylation, histone modifications and RNA interference) and large chromosome alterations (such as copy number variations, chromosome rearrangements and chromothripsis) associated with PDAC. In addition, we discussed variations in signalling pathways that act as intermediate oncogenic factors in PDAC, including PI3K/AKT, MAPK/ERK, Hippo and TGF-β signalling pathways. The focus of this review was to investigate alterations in the microenvironment of PDAC, particularly the role of immunosuppressive cells, cancer-associated fibroblasts, lymphocytes, other para-cancerous cells and tumour extracellular matrix in tumour progression. Peripheral axons innervating the pancreas have been reported to play a crucial role in the development of cancer. In addition, tumour cells can influence the behaviour of neighbouring non-tumour cells by secreting certain factors, both locally and at a distance. In this review, we elucidated the alterations in intracellular molecules and the extracellular environment that occur during the progression of PDAC. Altogether, this review may enhance the understanding of the biological characteristics of PDAC and guide the development of more precise treatment strategies.

Transcriptome analyses reveal new insights on key determinants of perineural invasion in high-grade serous ovarian cancer

Perineural invasion (PNI) is a pathological feature of many cancers associated with poor outcomes, metastases, and recurrence. In relation to ovarian cancer (OC), there is no information about PNI's role and mechanisms. Our study found that patients with PNI-positive symptoms had significantly shorter overall survival (OS) time than patients with PNI-negative symptoms. Multivariate analyses demonstrated that PNI represented a substantial independent prognostic factor in OC patients. At the transcriptome level, it is noteworthy that PNI positivity was negatively correlated with the degree of infiltration of immune killer cells in OC tumor tissues, including macrophage, central memory CD4 T-cell, natural killer cells, monocyte, and central memory CD4 T-cell. The results of this study revealed that TAS2Rs proteins were markedly upregulated in PNI-positive OC tissues and predicted poor prognoses. Moreover, Immunohistochemical analysis demonstrated that the TAS2R10 protein was associated with poor prognoses and PNI in OC. Consequently, we found for the first time that PNI was a powerful predictor of poor prognosis in OC and analyzed its expression pattern and some preliminary biochemical characterization, providing new clues for guiding clinical prevention and treatment of OC.

A novel prognostic model based on urea cycle-related gene signature for colorectal cancer

Background

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the world. This study aimed to develop a urea cycle (UC)-related gene signature that provides a theoretical foundation for the prognosis and treatment of patients with CRC.

Methods

Differentially expressed UC-related genes in CRC were confirmed using differential analysis and Venn diagrams. Univariate Cox and least absolute shrinkage and selection operator regression analyses were performed to identify UC-related prognostic genes. A UC-related signature was created and confirmed using distinct datasets. Independent prognostic predictors were authenticated using Cox analysis. The Cell-type Identification by Estimating Relative Subsets of RNA Transcripts algorithm and Spearman method were applied to probe the linkage between UC-related prognostic genes and tumor immune-infiltrating cells. The Human Protein Atlas database was used to determine the protein expression levels of prognostic genes in CRC and normal tissues. Verification of the expression levels of UC-related prognostic genes in clinical tissue samples was performed using real-time quantitative polymerase chain reaction (qPCR).

Results

A total of 49 DEUCRGs in CRC were mined. Eight prognostic genes (TIMP1, FABP4, MMP3, MMP1, CD177, CA2, S100P, and SPP1) were identified to construct a UC-related gene signature. The signature was then affirmed using an external validation set. The risk score was demonstrated to be a credible independent prognostic predictor using Cox regression analysis. Functional enrichment analysis revealed that focal adhesion, ECM-receptor interaction, IL-17 signaling pathway, and nitrogen metabolism were associated with the UC-related gene signature. Immune infiltration and correlation analyses revealed a significant correlation between UC-related prognostic genes and differential immune cells between the two risk subgroups. Finally, the qPCR results of clinical samples further confirmed the results of the public database.

Conclusion

Taken together, this study authenticated UC-related prognostic genes and developed a gene signature for the prognosis of CRC, which will be of great significance in the identification of prognostic molecular biomarkers, clinical prognosis prediction, and development of treatment strategies for patients with CRC.