Exosome-derived tRNA fragments tRF-GluCTC-0005 promotes pancreatic cancer liver metastasis by activating hepatic stellate cells

PPY-Induced iCAFs Cultivate an Immunosuppressive Microenvironment in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by cancer cells surrounded by affluent stromal components, which may underlie their limited response to various therapeutic interventions, including immunotherapy. Inflammatory cancer-associated fibroblasts (iCAFs), a crucial subset of CAFs within the PDAC microenvironment, play a pivotal role in shaping an immunosuppressive microenvironment. In this study, single-cell RNA sequencing analysis is performed to screen for cancer cells-secreted proteins associated with iCAF induction, and PPY (pancreatic polypeptide) is validated as a potent inducer. Unlike previously reported iCAF inducers, PPY is a gastrointestinal hormone predominantly expressed in the pancreas, suggesting that targeting it may have minimal systemic effects. Multiplex immunohistochemistry (mIHC) on human PDAC tissue microarrays, orthotopic allograft mouse models, and co-culture experiments are utilized to validate the crucial role of PPY in iCAF induction. Mechanistic studies integrating mRNA sequencing, immunoprecipitation-mass spectrometry, and molecular docking reveal that PPY induces iCAFs by activating the non-canonical NF-κB pathway through EGFR. Importantly, targeting PPY enhanced the efficacy of anti-PD-1 immunotherapy in KPC (KrasLSL-G12D/+; Trp53LSL-R172H/+; Pdx1-Cre) mice, as evidenced by reduced tumor burden on PET-CT imaging and improved survival. This research is expected to provide a novel strategy for improving immunotherapy in PDAC by targeting a key inducer of iCAFs.

Small extracellular vesicles (sEVs) in pancreatic cancer progression and diagnosis

Pancreatic cancer is one of the most aggressive malignancies with poor prognostic outcomes, necessitating the exploration of novel biomarkers and therapeutic targets for early detection and effective treatment. Small extracellular vesicles (sEVs) secreted by cells, have gained considerable attention in cancer research due to their role in intercellular communication and their potential as non-invasive biomarkers. This review focuses on the role of sEVs in the progression of pancreatic cancer and their application as biomarkers. We delve into the biogenesis, composition, and functional implications of sEVs in pancreatic tumor biology, emphasizing their involvement in processes such as tumor growth, metastasis, immune modulation, and chemotherapy resistance. In addition, we discuss the challenges in isolating and characterizing sEVs. The review also highlights recent advances in the utilization of sEV-derived biomarkers for the early diagnosis, prognosis, and monitoring of pancreatic cancer. By synthesizing the latest findings, we aim to underscore the significance of sEVs in pancreatic cancer and their potential to revolutionize patient management through improved diagnostics and targeted therapies.

Suprabasin promotes gastric cancer liver metastasis via hepatic stellate cells-mediated EGF/CCL2/JAK2 intercellular signaling pathways

Gastric cancer is among the most prevalent gastrointestinal tumors, with liver metastasis significantly worsening patient outcomes. While hepatic stellate cell activation is crucial in hepatocellular carcinoma progression and liver metastasis, its role in gastric cancer liver metastasis is not well understood. In this study, we identified Suprabasin (SBSN) as a key oncogene driving gastric cancer liver metastasis. SBSN was upregulated in gastric cancer tissues and further elevated in liver metastasis, correlating with poor prognosis. Mechanistically, SBSN promoted proliferation, migration, and invasion of gastric cancer cells by activating the STAT3 signaling pathway, as shown in vitro and in vivo. Using a co-culture model of gastric cancer cells and hepatic stellate cell line LX-2, we found that increased SBSN expression in gastric cancer cells triggered EGF secretion, activating LX-2 cells through the EGF/EGFR axis. Activated LX-2 cells then secreted CCL2, initiating the CCL2/CCR2/JAK2 signaling pathway in gastric cancer cells, facilitating their migration to the liver and promoting colonization and growth. Our findings highlight the prognostic significance of SBSN in gastric cancer and liver metastasis, suggesting it as a potential biomarker for disease progression. The SBSN-mediated EGF/EGFR and CCL2/CCR2/JAK2 signaling axes are critical for LX-2 activation and gastric cancer cell migration, offering a rationale for targeting SBSN in treating gastric cancer liver metastasis.

The role of tRNA-Derived small RNAs (tsRNAs) in pancreatic cancer and acute pancreatitis

tRNA-derived small RNAs (tsRNAs), encompassing tRNA fragments (tRFs) and tRNA-derived stress-induced RNAs (tiRNAs), represent a category of non-coding small RNAs (sncRNAs) that are increasingly recognized for their diverse biological functions. These functions include gene silencing, ribosome biogenesis, retrotransposition, and epigenetics. tsRNAs have been identified as key players in the progression of various tumors, yet their specific roles in pancreatic cancer (PC) and acute pancreatitis (AP) remain largely unexplored. Pancreatic cancer, particularly pancreatic ductal adenocarcinoma, is notorious for its high mortality rate and extremely low patient survival rate, primarily due to challenges in early diagnosis. Similarly, acute pancreatitis is a complex and significant disease. This article reviews the roles of 18 tsRNAs in PC and AP, focusing on their mechanisms of action and potential clinical applications in these two diseases. These tsRNAs influence the progression of pancreatic cancer and acute pancreatitis by modulating various pathways, including ZBP1/NLRP3, Hippo, PI3K/AKT, glycolysis/gluconeogenesis, and Wnt signaling. Notably, the dysregulation of tsRNAs is closely linked to critical clinical factors in pancreatic cancer and acute pancreatitis, such as lymph node metastasis, tumor-node-metastasis (TNM) stage, overall survival (OS), and disease-free survival (DFS). This article not only elucidates the mechanisms by which tsRNAs affect pancreatic cancer and acute pancreatitis but also explores their potential as biomarkers and therapeutic targets for pancreatic cancer. The insights provided here offer valuable references for future research, highlighting the importance of tsRNAs in the diagnosis and treatment of these challenging diseases.

Mapping Current Studies of tRNA Fragments onto Disease Landscape

Transfer-RNA-derived fragments (tRFs) are a relatively recently discovered class of non-coding RNAs derived from both precursor and mature transfer RNAs (tRNAs). Research on these molecules has been expanding rapidly, revealing their diverse roles in cellular processes, both in normal physiology and in disease states, often via post-transcriptional regulation of target genes. Altered tRFs abundances have been implicated in various conditions, where they may act as either drivers of disease progression or as protective agents. For instance, specific tRFs are associated with increased risk for cancer metastasis, while others may suppress tumor cell proliferation. Despite the growing recognition of tRFs as functional RNAs rather than sequencing noise, this field of study faces numerous challenges. Inconsistent naming conventions and variability in experimental approaches hinder the comparison of findings across studies, limiting our understanding of the common roles and mechanisms of tRFs. This review provides a comprehensive analysis of current literature on the various roles of tRFs in different diseases, particularly focusing on four broad areas: cancer, neurological, cardiovascular, and musculoskeletal disorders. We analyze studies that link specific tRFs to various aspects of human diseases and provide a convenient classification of these studies regarding the depth of the provided evidence. Further, we note gaps in current investigations and consider strategies to address methodological inconsistencies, including validation experiments and unified nomenclature. By consolidating research in this manner, we aim to facilitate comparisons across diverse studies, enhancing our ability to identify functional commonalities and furthering our understanding of the mechanisms by which tRFs act.

Endoscopic Ultrasound-Guided Brachytherapy of Yttrium-90 Implantation Into Pancreas: A Dose-Escalation Pilot Study

Intratumoral brachytherapy enables higher dose treatment and reduces damage to adjacent tissues. We first validated the feasibility and safety of endoscopic ultrasound (EUS)-guided Yttrium-90 (90Y) microspheres implantation in a porcine model. Under EUS guidance, 90Y-loaded microspheres were implanted into the pancreas of 10 miniature pigs. The first pig was implanted with 10 MBq particles. Subsequently, nine pigs were sequentially included in the low- (20 MBq), medium- (40 MBq), and high-dose (60 MBq) groups. Positron emission tomography (PET)/CT imaging was used to check the occurrence of particle displacement postoperatively. After euthanasia, the pancreas and adjacent organs were excised for histological examination and residue radiation detection. The absorbed doses demonstrated safe in the porcine model were further in the xenograft model and KRASLSL/+Trp53FL/FLPtfqaCre/+ mouse model. EUS-guided implantations of 90Y-loaded microspheres were successful in all animals. Two pigs had mild serum amylase elevation in the high-dose group and the abnormal index returned to baseline without interventions. The volume of necrotic lesions ranged from 255.76 to 745.57 mm3. In KPC mouse model, PET/CT imaging demonstrated a significant decrease in maximum standardized uptake value (SUVmax) after 90Y implantation. EUS-guided 90Y-loaded carbon microsphere implantation could serve as a safe and feasible technique at ultrahigh dose for pancreatic cancer brachytherapy.

The Role of Yes-Associated Protein in Inflammatory Diseases and Cancer

Yes-associated protein (YAP) plays a central role in the Hippo pathway, primarily governing cell proliferation, differentiation, and apoptosis. Its significance extends to tumorigenesis and inflammatory conditions, impacting disease initiation and progression. Given the increasing relevance of YAP in inflammatory disorders and cancer, this study aims to elucidate its pathological regulatory functions in these contexts. Specifically, we aim to investigate the involvement and molecular mechanisms of YAP in various inflammatory diseases and cancers. We particularly focus on how YAP activation, whether through Hippo-dependent or independent pathways, triggers the release of inflammation and inflammatory mediators in respiratory, cardiovascular, and digestive inflammatory conditions. In cancer, YAP not only promotes tumor cell proliferation and differentiation but also modulates the tumor immune microenvironment, thereby fostering tumor metastasis and progression. Additionally, we provide an overview of current YAP-targeted therapies. By emphasizing YAP's role in inflammatory diseases and cancer, this study aims to enhance our understanding of the protein's pivotal involvement in disease processes, elucidate the intricate pathological mechanisms of related diseases, and contribute to future drug development strategies targeting YAP.

Liver Metastasis in Cancer: Molecular Mechanisms and Management

Liver metastasis is a leading cause of mortality from malignant tumors and significantly impairs the efficacy of therapeutic interventions. In recent years, both preclinical and clinical research have made significant progress in understanding the molecular mechanisms and therapeutic strategies of liver metastasis. Metastatic tumor cells from different primary sites undergo highly similar biological processes, ultimately achieving ectopic colonization and growth in the liver. In this review, we begin by introducing the inherent metastatic-friendly features of the liver. We then explore the panorama of liver metastasis and conclude the three continuous, yet distinct phases based on the liver's response to metastasis. This includes metastatic sensing stage, metastatic stress stage, and metastasis support stage. We discuss the intricate interactions between metastatic tumor cells and various resident and recruited cells. In addition, we emphasize the critical role of spatial remodeling of immune cells in liver metastasis. Finally, we review the recent advancements and the challenges faced in the clinical management of liver metastasis. Future precise antimetastatic treatments should fully consider individual heterogeneity and implement different targeted interventions based on stages of liver metastasis.

Revealing the role of cancer-associated fibroblast senescence in prognosis and immune landscape in pancreatic cancer

Cancer-associated fibroblasts (CAFs) represent a major contributor to tumor growth. Cellular senescence is a state of cell-cycle arrest characterized by a pro-inflammatory phenotype. The potential impact of CAF senescence on tumor progression and the tumor microenvironment (TME) remains to be elucidated. Here, we systematically investigated the relationship between CAF senescence and the TME of pancreatic ductal adenocarcinoma (PDAC) based on multi-omics analysis and functional experiments. CAF senescence promotes tumor progression in vitro and in vivo and contributes to the formation of immunosuppressive TME. A CAF-senescence-related risk score was developed to predict overall survival, immune landscape, and treatment sensitivity in patients with PDAC. Further experiments revealed that plasminogen activator urokinase (PLAU) derived from senescent CAFs (SCAFs) promoted PDAC progression and was involved in immunosuppression. Together, these findings suggested that CAF senescence was correlated with tumor progression, and the CAF-senescence-based machine learning model could potentially predict prognosis in patients with PDAC.

tRNA-derived small RNAs in disease immunity

Recently, members of a unique species of non-coding RNA, known as transfer RNA-derived small RNAs (tsRNAs) have been reported to serve multiple molecular functions, including in cells that mediate immunity. Because of their low molecular weights, tsRNAs were previously difficult to detect and were thus overlooked, until now. In this review, we delve into the biogenesis of tsRNAs and their diverse biological functions, ranging from transcriptional regulation to modulation of mRNA translation. We highlight the current evidence demonstrating their involvement in the immune response, as well as how tsRNAs modulate immunity to influence tumor growth and spread, autoimmune disease pathology and infection by pathogens. We surmise that tsRNAs are likely informative as diagnostic markers of cellular homeostasis and disease, and that therapeutic targeting of tsRNAs could be beneficial for a range of human diseases. Improved knowledge on the functions for tsRNAs in the mammalian immune system will enable us to leverage tsRNAs for their effective clinical use as treatments for human health challenges.

Tumor-derived exosomes: Unravelling the pathogenesis of pancreatic cancer with liver metastases and exploring the potential for clinical translation

Pancreatic cancer (PC) is one of the most malignant solid cancers, and PC metastasis, particularly liver metastasis, is a major cause of cancer mortality. A key event in tumor metastasis is the formation of pre-metastatic niche (PMN), which provides a microenvironment conducive to tumor cells colonization and progression. Various molecules loaded in tumor-derived exosomes (TDEs) contribute to PMN formation and distant tumor metastasis, by regulating immune and stromal cell function, inducing angiogenesis, and promoting metabolic reprogramming. Therefore, therapies targeting PMN may offer novel advantages to prevent tumor metastasis at an earlier stage. In this review, we summarize multifaceted mechanisms underlying hepatic PMN formation, with a focus on how PC TDEs participate in angiogenesis and vascular permeability, create immune suppressive microenvironment, remodel the extracellular matrix, and regulate metabolic reprogramming. In addition, we highlight the promise of TDEs for early diagnosis and effective therapy of PC liver metastases.

Immune dynamics shaping pre-metastatic and metastatic niches in liver metastases: from molecular mechanisms to therapeutic strategies

Liver metastases are commonly detected in the advanced stages of various malignant tumors, representing a significant clinical challenge. Throughout the process of liver metastases formation, immune cells play a pivotal role, particularly in the pre-metastatic and metastatic niches within the liver. Immune cells establish extensive and intricate interactions with tumor cells and other components in the liver, collectively promoting and sustaining the growth of liver metastases. Despite the limited efficacy of existing therapeutic modalities against some advanced liver metastases, novel immune-based treatment approaches are continuously being explored and validated. Building on the systematic elucidation of the immunosuppressive characteristics of liver metastases, we explored the potential of novel immunotherapies applicable to patients with liver metastases from multiple dimensions.

Serum tsncRNAs reveals novel potential therapeutic targets of Salvianolic Acid B on atherosclerosis

BACKGROUND

Salvianolic Acid B (SalB) has been proven to delay the progression of atherosclerosis. The therapeutic mechanisms of this compound are unclear. A novel class of short non-coding RNAs, pre-transfer RNA and mature transfer RNA (tsncRNAs) may regulate gene expression. TsncRNAs-sequencing revealed novel therapeutic targets for SalB. This is the first study focusing on tsncRNAs to treat atherosclerosis using SalB.

PURPOSE

To explore the potential mechanism of SalB treating atherosclerosis through tsncRNAs.

METHODS

Five groups of mice were created at random: control group (CON), atherosclerosis model group (MOD), SalB with high dose-treated group (SABH), SalB with low dose-treated group (SABL), and Simvastatin-treated group (ST). Aortic sinus plaque, body weight and inflammatory cytokines were evaluated. The Illumina NextSeq equipment was used to do expression profiling of tsncRNAs from serum. The targets of tsncRNAs were then predicted using tRNAscan and TargetScan. The KEGG pathway and GO analysis were utilized to forecast the bioinformatics analysis. Potential tsncRNAs and associated mRNAs were validated using quantitative real-time PCR.

RESULTS

tRF-Glu-CTC-014 and tRF-Gly-GCC-074 were markedly increased by SalB with high dose treatment and validated with quantitative real-time PCR. Two mRNAs SRF and Arrb related to tRF-Glu-CTC-014 changed consistently. GO analysis revealed that the altered target genes of the selected tsncRNAs were most enriched in protein binding and cellular process. Moreover, KEGG pathway analysis demonstrated that altered target genes of tsncRNAs were most enriched in MAPK signaling pathway.

CONCLUSION

SalB can promote the expression of tRF-Glu-CTC-014 to treat atherosclerosis.

Pre-metastatic niche: formation, characteristics and therapeutic implication

Distant metastasis is a primary cause of mortality and contributes to poor surgical outcomes in cancer patients. Before the development of organ-specific metastasis, the formation of a pre-metastatic niche is pivotal in promoting the spread of cancer cells. This review delves into the intricate landscape of the pre-metastatic niche, focusing on the roles of tumor-derived secreted factors, extracellular vesicles, and circulating tumor cells in shaping the metastatic niche. The discussion encompasses cellular elements such as macrophages, neutrophils, bone marrow-derived suppressive cells, and T/B cells, in addition to molecular factors like secreted substances from tumors and extracellular vesicles, within the framework of pre-metastatic niche formation. Insights into the temporal mechanisms of pre-metastatic niche formation such as epithelial-mesenchymal transition, immunosuppression, extracellular matrix remodeling, metabolic reprogramming, vascular permeability and angiogenesis are provided. Furthermore, the landscape of pre-metastatic niche in different metastatic organs like lymph nodes, lungs, liver, brain, and bones is elucidated. Therapeutic approaches targeting the cellular and molecular components of pre-metastatic niche, as well as interventions targeting signaling pathways such as the TGF-β, VEGF, and MET pathways, are highlighted. This review aims to enhance our understanding of pre-metastatic niche dynamics and provide insights for developing effective therapeutic strategies to combat tumor metastasis.

The role of tRF-Val-CAC-010 in lung adenocarcinoma: implications for tumorigenesis and metastasis

OBJECTIVE

Transfer RNA-derived fragments (tRFs) are short non-coding RNA (ncRNA) sequences, ranging from 14 to 30 nucleotides, produced through the precise cleavage of precursor and mature tRNAs. While tRFs have been implicated in various diseases, including cancer, their role in lung adenocarcinoma (LUAD) remains underexplored. This study aims to investigate the impact of tRF-Val-CAC-010, a specific tRF molecule, on the phenotype of LUAD cells and its role in tumorigenesis and progression in vivo.

METHODS

The expression level of tRF-Val-CAC-010 was quantified using quantitative real-time polymerase chain reaction (qRT-PCR). Specific inhibitors and mimics of tRF-Val-CAC-010 were synthesized for transient transfection. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8), while cell invasion and migration were evaluated through Transwell invasion and scratch assays. Flow cytometry was utilized to analyze cell cycle and apoptosis. The in vivo effects of tRF-Val-CAC-010 on tumor growth and metastasis were determined through tumor formation and metastasis imaging experiments in nude mice.

RESULTS

The expression level of tRF-Val-CAC-010 was upregulated in A549 and PC9 LUAD cells (P < 0.01). Suppression of tRF-Val-CAC-010 expression resulted in decreased proliferation of A549 and PC9 cells (P < 0.001), reduced invasion and migration of A549 (P < 0.05, P < 0.001) and PC9 cells (P < 0.05, P < 0.01), enhanced apoptosis in both A549 (P < 0.05) and PC9 cells (P < 0.05), and increased G2 phase cell cycle arrest in A549 cells (P < 0.05). In vivo, the tumor formation volume in the tRF-inhibitor group was significantly smaller than that in the model and tRF-NC groups (P < 0.05). The metastatic tumor flux value in the tRF-inhibitor group was also significantly lower than that in the model and tRF-NC groups (P < 0.05).

CONCLUSION

This study demonstrates that tRF-Val-CAC-010 promotes proliferation, migration, and invasion of LUAD cells and induces apoptosis in vitro, however, its specific effects on the cell cycle require further elucidation. Additionally, tRF-Val-CAC-010 enhances tumor formation and metastasis in vivo. Therefore, tRF-Val-CAC-010 may serve as a novel diagnostic biomarker and potential therapeutic target for LUAD.

The systematic role of pancreatic cancer exosomes: distant communication, liquid biopsy and future therapy

Pancreatic cancer remains one of the most lethal diseases worldwide. Cancer-derived exosomes, benefiting from the protective role of the lipid membrane, exhibit remarkable stability in the circulatory system. These exosomes, released by tumor microenvironment, contain various biomolecules such as proteins, RNAs, and lipids that plays a pivotal role in mediating distant communication between the local pancreatic tumor and other organs or tissues. They facilitate the transfer of oncogenic factors to distant sites, contributing to the compromised body immune system, distant metastasis, diabetes, cachexia, and promoting a microenvironment conducive to tumor growth and metastasis in pancreatic cancer patients. Beyond their intrinsic roles, circulating exosomes in peripheral blood can be detected to facilitate accurate liquid biopsy. This approach offers a novel and promising method for the diagnosis and management of pancreatic cancer. Consequently, circulating exosomes are not only crucial mediators of systemic cell-cell communication during pancreatic cancer progression but also hold great potential as precise tools for pancreatic cancer management and treatment. Exosome-based liquid biopsy and therapy represent promising advancements in the diagnosis and treatment of pancreatic cancer. Exosomes can serve as drug delivery vehicles, enhancing the targeting and efficacy of anticancer treatments, modulating the immune system, and facilitating gene editing to suppress tumor growth. Ongoing research focuses on biomarker identification, drug delivery systems, and clinical trials to validate the safety and efficacy of exosome-based therapies, offering new possibilities for early diagnosis and precision treatment in pancreatic cancer. Leveraging the therapeutic potential of exosomes, including their ability to deliver targeted drugs and modulate immune responses, opens new avenues for innovative treatment strategies.