Exosomal lncRNA UCA1 Derived From Pancreatic Stellate Cells Promotes Gemcitabine Resistance in Pancreatic Cancer via the SOCS3/EZH2 Axis

Hypoxia makes EZH2 inhibitor not easy-advances of crosstalk between HIF and EZH2

Histone methylation plays a crucial role in tumorigenesis. Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that regulates chromatin structure and gene expression. EZH2 inhibitors (EZH2is) have been shown to be effective in treating hematologic malignancies, while their effectiveness in solid tumors remains limited. One of the major challenges in the treatment of solid tumors is their hypoxic tumor microenvironment. Hypoxia-inducible factor 1-alpha (HIF-1α) is a key hypoxia responder that interacts with EZH2 to promote tumor progression. Here we discuss the implications of the relationship between EZH2 and hypoxia for expanding the application of EZH2is in solid tumors.

Pancreatic cancer cell- and cancer-associated fibroblast-derived exosomes in disease progression, metastasis, and therapy

Exosomes play a crucial role in the progression and spread of pancreatic cancer, serving not only as promoters of tumor growth and organ-specific metastasis but also as promising biomarkers and targets for treatment. These nano vesicles enhance intercellular communication by transferring bioactive molecules, such as proteins and RNAs, between cells. This process significantly affects cancer cell dynamics, including their proliferation, migration, and invasion, while also contributing to drug resistance. Our review focuses on the crucial interactions between cancer cells and fibroblasts mediated by exosomes within the pancreatic cancer microenvironment. We delve into how exosomes from both cancer-associated fibroblasts and the cancer cells themselves drive tumor progression through various mechanisms, such as epithelial-mesenchymal transition and facilitating metastasis to specific organs like the lungs and liver. The potential of leveraging exosomes for therapeutic interventions is also explored, highlighting the importance of understanding their role in cell communication as a step forward in developing more effective pancreatic cancer treatments.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Long non-coding RNAs and tyrosine kinase-mediated drug resistance in pancreatic cancer

Pancreatic cancer (PC) is one of the most malignant tumors with a dismal survival rate, this is primarily due to inevitable chemoresistance. Dysfunctional tyrosine kinases (TKs) and long non-coding RNAs (lncRNAs) affect the drug resistance and prognosis of PC. Here, we summarize the mechanisms by which TKs or lncRNAs mediate drug resistance and other malignant phenotypes. We also discuss that lncRNAs play oncogenic or tumor suppressor roles and different mechanisms including lncRNA-proteins/microRNAs to mediate drug resistance. Furthermore, we highlight that lncRNAs serve as upstream regulators of TKs mediating drug resistance. Finally, we display the clinical significance of TKs (AXL, EGFR, IGF1R, and MET), clinical trials, and lncRNAs (LINC00460, PVT1, HIF1A-AS1). In the future, TKs and lncRNAs may become diagnostic and prognostic biomarkers or drug targets to overcome the drug resistance of PC.

Acquired and intrinsic gemcitabine resistance in pancreatic cancer therapy: Environmental factors, molecular profile and drug/nanotherapeutic approaches

A high number of cancer patients around the world rely on gemcitabine (GEM) for chemotherapy. During local metastasis of cancers, surgery is beneficial for therapy, but dissemination in distant organs leads to using chemotherapy alone or in combination with surgery to prevent cancer recurrence. Therapy failure can be observed as a result of GEM resistance, threatening life of pancreatic cancer (PC) patients. The mortality and morbidity of PC in contrast to other tumors are increasing. GEM chemotherapy is widely utilized for PC suppression, but resistance has encountered its therapeutic impacts. The purpose of current review is to bring a broad concept about role of biological mechanisms and pathways in the development of GEM resistance in PC and then, therapeutic strategies based on using drugs or nanostructures for overcoming chemoresistance. Dysregulation of the epigenetic factors especially non-coding RNA transcripts can cause development of GEM resistance in PC and miRNA transfection or using genetic tools such as siRNA for modulating expression level of these factors for changing GEM resistance are suggested. The overexpression of anti-apoptotic proteins and survival genes can contribute to GEM resistance in PC. Moreover, supportive autophagy inhibits apoptosis and stimulates GEM resistance in PC cells. Increase in metabolism, glycolysis induction and epithelial-mesenchymal transition (EMT) stimulation are considered as other factors participating in GEM resistance in PC. Drugs can suppress tumorigenesis in PC and inhibit survival factors and pathways in increasing GEM sensitivity in PC. More importantly, nanoparticles can increase pharmacokinetic profile of GEM and promote its blood circulation and accumulation in cancer site. Nanoparticles mediate delivery of GEM with genes and drugs to suppress tumorigenesis in PC and increase drug sensitivity. The basic research displays significant connection among dysregulated pathways and GEM resistance, but the lack of clinical application is a drawback that can be responded in future.

Hypoxic regulation of extracellular vesicles: Implications for cancer therapy

Extracellular vesicles (EVs) play a pivotal role in intercellular communication and have been implicated in cancer progression. Hypoxia, a pervasive hallmark of cancer, is known to regulate EV biogenesis and function. Hypoxic EVs contain a specific set of proteins, nucleic acids, lipids, and metabolites, capable of reprogramming the biology and fate of recipient cells. Enhancing the intrinsic therapeutic efficacy of EVs can be achieved by strategically modifying their structure and contents. Moreover, the use of EVs as drug delivery vehicles holds great promise for cancer treatment. However, various hurdles must be overcome to enable their clinical application as cancer therapeutics. In this review, we aim to discuss the current knowledge on the hypoxic regulation of EVs. Additionally, we will describe the underlying mechanisms by which EVs contribute to cancer progression in hypoxia and outline the progress and limitations of hypoxia-related EV therapeutics for cancer.

Unveiling the functional paradigm of exosome-derived long non-coding RNAs (lncRNAs) in cancer: based on a narrative review and systematic review

BACKGROUND AND PURPOSE

The intricate mechanisms underlying intercellular communication within the tumor microenvironment remain largely elusive. Recently, attention has shifted towards exploring the intercellular signaling mediated by exosomal long non-coding RNAs (lncRNAs) within this context. This comprehensive systematic review aims to elucidate the functional paradigm of exosome-derived lncRNAs in cancer.

MATERIALS AND METHODS

The review provides a comprehensive narrative of lncRNA definition, characteristics, as well as the formation, sorting, and uptake processes of exosome-derived lncRNAs. Additionally, it describes comprehensive technology for exosome research and nucleic acid drug loading. This review further systematically examines the cellular origins, functional roles, and underlying mechanisms of exosome-derived lncRNAs in recipient cells within the cancer setting.

RESULTS

The functional paradigm of exosome-derived lncRNAs in cancer mainly depends on the source cells and sorting mechanism of exosomal lncRNAs, the recipient cells and uptake mechanisms of exosomal lncRNAs, and the specific molecular mechanisms of lncRNAs in recipient cells. The source cells of exosomal lncRNAs mainly involved in the current review included tumor cells, cancer stem cells, normal cells, macrophages, and cancer-associated fibroblasts.

CONCLUSION

This synthesis of knowledge offers valuable insights for accurately identifying exosomal lncRNAs with potential as tumor biomarkers. Moreover, it aids in the selection of appropriate targeting strategies and preclinical models, thereby facilitating the clinical translation of exosomal lncRNAs as promising therapeutic targets against cancer. Through a comprehensive understanding of the functional role of exosome-derived lncRNAs in cancer, this review paves the way for advancements in personalized medicine and improved treatment outcomes.

Long non-coding RNAs and pancreatic cancer: A multifaceted view

Pancreatic cancer (PC) is a highly malignant disease with a 5-year survival rate of only 10%. Families with PC are at greater risk, as are type 2 diabetes, pancreatitis, and other factors. Insufficient early detection methods make this cancer have a poor prognosis. Additionally, the molecular mechanisms underlying PC development remain unclear. Increasing evidence suggests that long non-coding RNAs (lncRNAs) contribute to PC pathology,which may control gene expression by recruiting histone modification complexes to chromatin and interacting with proteins and RNAs. In recent studies, abnormal regulation of lncRNAs has been implicated in PC proliferation, metastasis, invasion, angiogenesis, apoptosis, and chemotherapy resistance suggesting potential clinical implications. The paper reviews the progress of lncRNA research in PC about diabetes mellitus, pancreatitis, cancer metastasis, tumor microenvironment regulation, and chemoresistance. Furthermore, lncRNAs may serve as potential therapeutic targets and biomarkers for PC diagnosis and prognosis. This will help improve PC patients' survival rate from a lncRNA perspective.

Blood exosome marker miRNA-30d-5p: Role and regulation mechanism in cell stemness and gemcitabine resistance of hepatocellular carcinoma

BACKGROUND

Cancer stem cells (CSCs) are different from regular cancer cells because of their self-renewal feature and differentiation potential, which establishes the backbone of the vital role of CSCs in the progress and drug resistance of hepatocellular carcinoma (HCC). The objective of this study was to evaluate the effects of blood exosome-derived miRNA-30d-5p on the stemness and gemcitabine resistance of HCC cells and the underlying mechanisms.

METHODS

The expression data of HCC-related miRNAs and mRNAs were downloaded from TCGA database and analyzed for differences. Employing the databases of starBase, TargetScan, miRDB, and mirDIP, we conducted target gene prediction upstream of mRNA. The expression of miRNA-30d-5p and SOCS3 mRNA was assayed by qRT-PCR, and the binding between them was validated by dual luciferase assay. CCK-8 was employed to evaluate cell viability and the IC50 value of gemcitabine. Cells were subjected to a sphere-forming assay to assess their ability to form spheres. Western blot was applied to evaluate the levels of cell surface marker proteins (Nanog, CD133, and Oct4) and exosome markers (CD9, CD81, and FLOT1).

RESULTS

Bioinformatics analysis found that SOCS3 expression was down-regulated in HCC. qRT-PCR showed that SOCS3 expression was notably lower in HCC cell lines than in normal liver cell WRL68. At the cellular functional level, SOCS3 overexpression inhibited the viability, sphere-forming ability, stemness, and gemcitabine resistance of HCC cells. Bioinformatics analysis demonstrated that miRNA-30d-5p was the upstream regulator of SOCS3 and highly expressed in HCC tissues and cells. Dual luciferase assay demonstrated that miRNA-30d-5p could bind SOCS3. Rescue experiments showed that upregulating SOCS3 could reverse the effects of miRNA-30d-5p overexpression on the viability, sphere-forming ability, and gemcitabine sensitivity of HCC cells.

CONCLUSIONS

Blood exosome-derived miRNA-30d-5p promoted the stemness and gemcitabine resistance of HCC cells by repressing SOCS3 expression. Hence, the miRNA-30d-5p/SOCS3 axis might be a therapeutic target for chemotherapy resistance and a feasible marker for the prognosis of HCC patients.

Pancreatic stellate cell-derived exosomal tRF-19-PNR8YPJZ promotes proliferation and mobility of pancreatic cancer through AXIN2

The pancreatic stellate cells (PSCs) play an important role in the development of pancreatic cancer (PC) through mechanisms that remain unclear. Exosomes secreted from PSCs act as mediators for communication in PC. This study aimed to explore the role of PSC-derived exosomal small RNAs derived from tRNAs (tDRs) in PC cells. Exosomes from PSCs were extracted and used to detect their effects on PC cell proliferation, migration and invasion. Exosomal tDRs profiling was performed to identify PSC-derived exosomal tDRs. ISH and qRT-PCR were used to examine the tRF-19-PNR8YPJZ levels and clinical value in clinical samples. The biological function of exosomal tRF-19-PNR8YPJZ was determined using the CCK-8, clone formation, wound healing and transwell assays, subcutaneous tumour formation and lung metastatic models. The relationship between the selected exosomal tRF-19-PNR8YPJZ and AXIN2 was determined by RNA sequencing, luciferase reporter assay. PSC-derived exosomes promoted the proliferation, migration, and invasion of PC cells. Novel and abundant tDRs are found to be differentially expressed in PANC-1 cells after treatment with PSC-derived exosomes, such as tRF-19-PNR8YPJZ. PC tissue samples showed markedly higher levels of tRF-19-PNR8YPJZ than normal controls. Patients with PC exhibiting high tRF-19-PNR8YPJZ expression had a highly lymph node invasion, metastasis, perineural invasion, advanced clinical stage and poor overall survival. Exosomal tRF-19-PNR8YPJZ from PSCs targeted AXIN2 in PC cells and decreased its expression, thus activating the Wnt pathway and promoting proliferation and metastasis. Exosomal tRF-19-PNR8YPJZ from PSCs promoted proliferation and metastasis in PC cells via AXIN2.

Epigenetic regulation of temozolomide resistance in human cancers with an emphasis on brain tumors: Function of non-coding RNAs

Brain tumors, which are highly malignant, pose a significant threat to health and often result in substantial rates of mortality and morbidity worldwide. The brain cancer therapy has been challenging due to obstacles such as the BBB, which hinders effective delivery of therapeutic agents. Additionally, the emergence of drug resistance further complicates the management of brain tumors. TMZ is utilized in brain cancer removal, but resistance is a drawback. ncRNAs are implicated in various diseases, and their involvement in the cancer is particularly noteworthy. The focus of the current manuscript is to explore the involvement of ncRNAs in controlling drug resistance, specifically in the context of resistance to the chemotherapy drug TMZ. The review emphasizes the function of ncRNAs, particularly miRNAs, in modulating the growth and invasion of brain tumors, which significantly influences their response to TMZ treatment. Through their interactions with various molecular pathways, miRNAs are modulators of TMZ response. Similarly, lncRNAs also associate with molecular pathways and miRNAs, affecting the efficacy of TMZ chemotherapy. Given their functional properties, lncRNAs can either induce or suppress TMZ resistance in brain tumors. Furthermore, circRNAs, which are cancer controllers, regulate miRNAs by acting as sponges, thereby impacting the response to TMZ chemotherapy. The review explores the correlation between ncRNAs and TMZ chemotherapy, shedding light on the underlying molecular pathways involved in this process.

Role of the long non-coding RNAs in regulation of Gemcitabine response in tumor cells

Chemotherapy is widely used as one of the first line therapeutic methods in cancer patients. However, chemotherapeutic resistance is one of the most common problems in cancer patients, which leads to the therapeutic failure and tumor relapse. Considering the side effects of chemotherapy drugs in normal tissues, it is required to investigate the molecular mechanisms involved in drug resistance to improve the therapeutic strategies in cancer patients. Long non-coding RNAs (lncRNAs) have pivotal roles in regulation of cellular processes associated with drug resistance. LncRNAs deregulations have been frequently reported in a wide range of chemo-resistant tumors. Gemcitabine (GEM) as a nucleoside analog has a wide therapeutic application in different cancers. However, GEM resistance is considered as a therapeutic challenge. Considering the role of lncRNAs in the occurrence of GEM resistance, in the present review we discussed the molecular mechanisms of lncRNAs in regulation of GEM response among cancer patients. It has been reported that lncRNAs have mainly an oncogenic role as the inducers of GEM resistance through direct or indirect regulation of transcription factors, autophagy, polycomb complex, and signaling pathways such as PI3K/AKT, MAPK, WNT, JAK/STAT, and TGF-β. This review paves the way to present the lncRNAs as non-invasive markers to predict GEM response in cancer patients. Therefore, lncRNAs can be introduced as the efficient markers to reduce the possible chemotherapeutic side effects in GEM resistant cancer patients and define a suitable therapeutic strategy among these patients.

Emerging role of pancreatic stellate cell-derived extracellular vesicles in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer that is characterised by a prominent collagenous stromal reaction/desmoplasia surrounding tumour cells. Pancreatic stellate cells (PSCs) are responsible for the production of this stroma and have been shown to facilitate PDAC progression. Recently, extracellular vesicles (EVs), in particular, small extracellular vesicles (exosomes) have been a topic of interest in the field of cancer research for their emerging roles in cancer progression and diagnosis. EVs act as a form of intercellular communication by carrying their molecular cargo from one cell to another, regulating functions of the recipient cells. Although the knowledge of the bi-directional interactions between the PSCs and cancer cells that promote disease progression has advanced significantly over the past decade, studies on PSC-derived EVs in PDAC are currently rather limited. This review provides an overview of PDAC, pancreatic stellate cells and their interactions with cancer cells, as well as the currently known role of extracellular vesicles derived from PSCs in PDAC progression.

Noncoding RNAs: an emerging modulator of drug resistance in pancreatic cancer

Pancreatic cancer is the eighth leading cause of cancer-related deaths worldwide. Chemotherapy including gemcitabine, 5-fluorouracil, adriamycin and cisplatin, immunotherapy with immune checkpoint inhibitors and targeted therapy have been demonstrated to significantly improve prognosis of pancreatic cancer patients with advanced diseases. However, most patients developed drug resistance to these therapeutic agents, which leading to shortened patient survival. The detailed molecular mechanisms contributing to pancreatic cancer drug resistance remain largely unclear. The growing evidences have shown that noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are involved in pancreatic cancer pathogenesis and development of drug resistance. In the present review, we systematically summarized the new insight on of various miRNAs, lncRNAs and circRNAs on drug resistance of pancreatic cancer. These results demonstrated that targeting the tumor-specific ncRNA may provide novel options for pancreatic cancer treatments.

Long Non-Coding RNAs and Metabolic Rewiring in Pancreatic Cancer

Pancreatic adenocarcinoma is a highly aggressive disease with a poor prognosis. The reprogramming of energetic metabolism has long been implicated in pancreatic tumorigenesis and/or resistance to treatment. Considering that long non-coding RNA dysregulation has been described both in cancerogenesis and in the altered homeostasis of several metabolic pathways, metabolism-associated lncRNAs can contribute to pancreatic cancer evolution. The objective of this review is to assess the burden of lncRNA dysregulation in pancreatic cancer metabolic reprogramming, and its effect on this tumor's natural course and response to treatment. Therefore, we reviewed the available literature to assess whether metabolism-associated lncRNAs have been found to be differentially expressed in pancreatic cancer, as well as whether experimental evidence of their role in such pathways can be demonstrated. Specifically, we provide a comprehensive overview of lncRNAs that are implicated in hypoxia-related pathways, as well as in the reprogramming of autophagy, lipid metabolism, and amino acid metabolism. Our review gathers background material for further research on possible applications of metabolism-associated lncRNAs as diagnostic/prognostic biomarkers and/or as potential therapeutic targets in pancreatic adenocarcinoma.

Low level TGF-β1-treated Umbilical mesenchymal stem cells attenuates microgliosis and neuropathic pain in chronic constriction injury by exosomes/lncRNA UCA1／miR-96-5p／FOXO3a

Neuropathic pain is a chronic pain state that usually caused by injuries in peripheral or central nerve. Inhibition of spinal microglial response is a promising treatment of neuropathic pain caused by peripheral nerve injury. In recent years, mesenchymal stem cells (MSCs) that characterized with multipotent ability have been widely studied for disease treatment. TGF-β1 is a well-known regulatory cytokine that participate in the response to cell stress and is closely correlated with the function of nerve system as well as MSC differentiation. This work aimed to determine the effects of exosomes that extracted from TGF-β1-induced umbilical mesenchymal stem cells (hUCSMCs) on the neuropathic pain. In this work, we established a rat model of chronic constriction injury (CCI) of the sciatic nerve and LPS-induced microglia cell model. The hUCSMCs cell surface biomarker was identified by flow cytometry. Exosomes that extracted from TGF-β1-treated hUCSMCs were characterized by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) and used for treatment. We observed that TGF-β1 upregulates the level of lncRNA UCA1 (UCA1) in hUCMSC-derived exosomes. Treatment with exosomal lncRNA UCA1 (UCA1) alleviated the neuropathic pain, microgliosis, and production of inflammatory mediator both in vivo and in vitro. UCA1 directly interact with the miR-96-5p, and the miR-96-5p acts as sponge of FOXO3a. Knockdown of UCA1 upregulated the level of miR-96-5p and downregulated the FOXO3a expression, which could be recovered by inhibition of miR-96-5p. In summary, the TGF-β1-stimulated exosomal UCA1 from hUCMSCs alleviates the neuropathic pain and microgliosis. These findings may provide novel evidence for treatment of neuropathic pain caused by chronic constriction injury.

Fibroblasts in pancreatic cancer: molecular and clinical perspectives

Pancreatic stellate cells (PSCs) and cancer-associated fibroblasts (CAFs) are highly abundant cells in the pancreatic tumor microenvironment (TME) that modulate desmoplasia. The formation of a dense stroma leads to immunosuppression and therapy resistance that are major causes of treatment failure in pancreatic ductal adenocarcinoma (PDAC). Recent evidence suggests that several subpopulations of CAFs in the TME can interconvert, explaining the dual roles (antitumorigenic and protumorigenic) of CAFs in PDAC and the contradictory results of CAF-targeted therapies in clinical trials. This highlights the need to clarify CAF heterogeneity and their interactions with PDAC cells. This review focuses on the communication between activated PSCs/CAFs and PDAC cells, as well as on the mechanisms underlying this crosstalk. CAF-focused therapies and emerging biomarkers are also outlined.

Role of long non-coding RNAs in pancreatic cancer pathogenesis and treatment resistance- A review

Pancreatic cancer (PC) is one of the deadliest cancers associated with poor prognosis. The lack of reliable means of early cancer detection contributes to this disease's dismal prognosis. Long non-coding RNAs (LncRNAs) are protein-free RNAs produced by genome transcription; they play critical roles in gene expression regulation, epigenetic modification, cell proliferation, differentiation, and reproduction. Recent research has shown that lncRNAs play important regulatory roles in PC behaviors, in addition to their recently found functions. Several in-depth investigations have shown that lncRNAs are strongly linked to PC development and progression. Here, we discuss how lncRNAs, which are often overlooked, play many roles as regulators in the molecular mechanism underlying PC. This review also discusses the involved LncRNAs in PC pathogenesis and treatment resistance.

Extracellular Vesicle-Loaded Oncogenic lncRNA NEAT1 from Adipose-Derived Mesenchymal Stem Cells Confers Gemcitabine Resistance in Pancreatic Cancer via miR-491-5p/Snail/SOCS3 Axis

It is becoming increasingly evident that key mechanisms of mesenchymal stem cell (MSC) efficacy appear to associate with paracrine activities, and the delivery of cargos through extracellular vesicles (EVs) controls the mechanistic actions of MSCs. Thus, this study clarified a possible mechanism by which EV-encapsulated NEAT1 from adipose-derived mesenchymal stem cells (ADSCs) might mediate gemcitabine resistance in pancreatic cancer (PCa). Microarray profile suggested a differentially expressed lncRNA NEAT1 in PCa, and we determined its expression in PCa cells. NEAT1 was found to be upregulated in PCa. The binding affinity among NEAT1, miR-491-5p, and Snail was identified through bioinformatic analysis and experimental validation. NEAT1 competitively bound to miR-491-5p to elevate Snail expression and diminish SOCS3 expression. PCa cells were cocultured with EVs extracted from ADSCs, followed by assessment of malignant phenotypes, tumorigenesis, and gemcitabine resistance of PCa cells using gain- or loss-of-function experiments. ADSC-derived EVs carrying NEAT1 promoted PCa cell proliferation, migration, and gemcitabine resistance in vitro and enhanced tumorigenicity in vivo by inhibiting miR-491-5p and SOCS3 and upregulating Snail. Collectively, the findings from our study found a new potential strategy for gemcitabine resistance in PCa by illustrating the mechanistic insights of oncogenic ADSC-derived EVs-loaded NEAT1 via regulating the miR-491-5p/Snail/SOCS3 axis.

The Functional Role of LncRNA UCA1 in Pancreatic Cancer: a mini-review

Pancreatic cancer (PaC) is a common malignant tumor of the digestive tract, with a 5-year survival rate of less than 5% and high mortality rate in the world. LncRNAs have been showed to possess multiple biological functions in growth, differentiation, and proliferation, which play an important role in different biological processes and diseases, especially in the development of tumors. LncRNA UCA1, which is firstly identified in human bladder cancer, has been showed to be a tumor promoter in pancreatic cancer. Recent researches have showed that UCA1 might promote pancreatic carcinogenesis and progression, and correlate with drug resistance. In this review, we address the biological function and regulatory mechanism of UCA1 in pancreatic cancer, which might give a new approach for clinical diagnosis and treatment.

The Involvement of Long Non-Coding RNAs in Glutamine-Metabolic Reprogramming and Therapeutic Resistance in Cancer

Metabolic alterations that support the supply of biosynthetic molecules necessary for rapid and sustained proliferation are characteristic of cancer. Some cancer cells rely on glutamine to maintain their energy requirements for growth. Glutamine is an important metabolite in cells because it not only links to the tricarboxylic acid cycle by producing α-ketoglutarate by glutaminase and glutamate dehydrogenase but also supplies other non-essential amino acids, fatty acids, and components of nucleotide synthesis. Altered glutamine metabolism is associated with cancer cell survival, proliferation, metastasis, and aggression. Furthermore, altered glutamine metabolism is known to be involved in therapeutic resistance. In recent studies, lncRNAs were shown to act on amino acid transporters and glutamine-metabolic enzymes, resulting in the regulation of glutamine metabolism. The lncRNAs involved in the expression of the transporters include the abhydrolase domain containing 11 antisense RNA 1, LINC00857, plasmacytoma variant translocation 1, Myc-induced long non-coding RNA, and opa interacting protein 5 antisense RNA 1, all of which play oncogenic roles. When it comes to the regulation of glutamine-metabolic enzymes, several lncRNAs, including nuclear paraspeckle assembly transcript 1, XLOC_006390, urothelial cancer associated 1, and thymopoietin antisense RNA 1, show oncogenic activities, and others such as antisense lncRNA of glutaminase, lincRNA-p21, and ataxin 8 opposite strand serve as tumor suppressors. In addition, glutamine-dependent cancer cells with lncRNA dysregulation promote cell survival, proliferation, and metastasis by increasing chemo- and radio-resistance. Therefore, understanding the roles of lncRNAs in glutamine metabolism will be helpful for the establishment of therapeutic strategies for glutamine-dependent cancer patients.

Molecular subtyping based on TRP family and prognostic assessment for TRP-associated lncRNAs in pancreatic adenocarcinoma

Background

Transient receptor potential (TRP) channels have high permeability to Ca2⁺ ions because they are non-selective ion channels. TRP channels have been implicated in tumor onset and progression, proliferation, and migration in recent years. However, the prognostic value of genes related to TRP and their specific mechanism in pancreatic adenocarcinoma (PAAD) are yet to be understood.

Methods

Public databases such as TCGA and GEO were used to retrieve data on gene expression and clinical information of patients with pancreatic adenocarcinoma for our study. ConsensusClusterPlus package was used for unsupervised clustering analysis. The microenvironment cell population (MCP)-counter approach was employed to measure the immune cells infiltration status. The Pearson correlation was performed to identify TRP-associated lncRNAs.

Results

Initially, we separated PAAD patients into three clusters depending on TRP-related genes, and of the three clusters, cluster B showed the least immune cell infiltration, which was correlated with poor prognosis. Moreover, GSVA enrichment analysis further revealed that cluster A was subjected to a considerable enrichment in carcinogenic signaling pathways, whereas cluster C was enriched in immune-related pathways. Then, using TRP-associated lncRNAs as a starting point, we constructed a prognostic risk model for PAAD patients that could efficiently predict their prognosis. Further, GSEA revealed that cancer-related pathways, for instance, the cell cycle, p53 signaling pathway, etc. were considerably enriched in the high-risk group. In addition, we looked into the link between the prognostic model and the immunological microenvironment. Lower cytotoxic lymphocytes, NK cells, CD8 T cells, and endothelial cells infiltration were found to be associated with high risk using the MCP-counter algorithm. The expression of CD274, POLE2, MCM6, and LOXL2 was also found to be higher in the high-risk group. TMB was also considerably greater in high-risk individuals, indicating that immune checkpoint inhibitors (ICIs) therapy may benefit them more. Lastly, qRT-PCR further confirmed the differential expression of these prognostic TRP-associated lncRNAs, indicating that these lncRNAs play an imperative role in PAAD tumorigenesis.

Conclusion

TRP family genes may represent a new class of candidate molecular markers of the occurrence and progression of PAAD. Risk models based on TRP-associated lncRNAs could provide important new references for immunotargeted therapy of pancreatic adenocarcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02552-y.

LncRNA-miRNA axis in tumor progression and therapy response: An emphasis on molecular interactions and therapeutic interventions

Epigenetic factors are critical regulators of biological and pathological mechanisms and they could interact with different molecular pathways. Targeting epigenetic factors has been an idea approach in disease therapy, especially cancer. Accumulating evidence has highlighted function of long non-coding RNAs (lncRNAs) as epigenetic factors in cancer initiation and development and has focused on their association with downstream targets. microRNAs (miRNAs) are the most well-known targets of lncRNAs and present review focuses on lncRNA-miRNA axis in malignancy and therapy resistance of tumors. LncRNA-miRNA regulates cell death mechanisms such as apoptosis and autophagy in cancers. This axis affects tumor metastasis via regulating EMT and MMPs. Besides, lncRNA-miRNA axis determines sensitivity of tumor cells to chemotherapy, radiotherapy and immunotherapy. Based on the studies, lncRNAs can be affected by drugs and genetic tools in cancer therapy and this may affect expression level of miRNAs as their downstream targets, leading to cancer suppression/progression. LncRNAs have both tumor-promoting and tumor-suppressor functions in cancer and this unique function of lncRNAs has complicated their implication in tumor therapy. LncRNA-miRNA axis can also affect other signaling networks in cancer such as PI3K/Akt, STAT3, Wnt/β-catenin and EZH2 among others. Notably, lncRNA/miRNA axis can be considered as a signature for diagnosis and prognosis in cancers.

Extracellular vesicle-mediated crosstalk between pancreatic cancer and stromal cells in the tumor microenvironment

Pancreatic ductal adenocarcinoma (PDAC) interacts closely with the tumor microenvironment (TME). The TME is remodeled by crosstalk between pancreatic cancer cells and stromal cells, and is critical for cancer progression. Extracellular vesicles (EVs), including exosomes and microvesicles, help facilitate an exchange of information both within the TME and to distant organs. EVs have also been identified as potential diagnostic biomarkers, therapeutic targets, and drug carriers for pancreatic cancer treatment. Thus, understanding the selective packaging of EVs cargo and its mechanistic impact will increase our understanding of cancer biology. In this review, we collect and analyze recent findings of the pancreatic cancer-stromal cell interactions mediated by EVs and the mechanisms involved in cancer-related immunity and chemoresistance. These studies demonstrate the vital role of EVs in pancreatic cancer reprogramming and TME remodeling. We also summarize the EVs identified as potential PDAC diagnostic biomarkers and possible therapeutic targets. This greater understanding is a promising avenue for transitioning EVs from bench to bedside.

Exosomes and ferroptosis: roles in tumour regulation and new cancer therapies

Research on the biological role of exosomes is rapidly developing, and recent evidence suggests that exosomal effects involve ferroptosis. Exosomes derived from different tissues inhibit ferroptosis, which increases tumour cell chemoresistance. Therefore, exosome-mediated regulation of ferroptosis may be leveraged to design anticancer drugs. This review discusses three pathways of exosome-mediated inhibition of ferroptosis: (1) the Fenton reaction; (2) the ferroptosis defence system, including the Xc-GSH-GPX4 axis and the FSP1/CoQ₁₀/NAD(P)H axis; and (3) lipid peroxidation. We also summarize three recent approaches for combining exosomes and ferroptosis in oncology therapy: (1) promoting exosome-inhibited ferroptosis to enhance chemotherapy; (2) encapsulating exosomes with ferroptosis inducers to inhibit cancers; and (3) developing therapies that combine exosomal inhibitors and ferroptosis inducers. This review will contribute toward establishing effective cancer therapies.

Hypoxia Induced Changes of Exosome Cargo and Subsequent Biological Effects

Exosomes are small extracellular vesicles that are secreted by almost all types of cells and exist in almost all extracellular spaces. As an important mediator of intercellular communication, exosomes encapsulate the miRNA, lncRNA, cirRNA, mRNA, cytokine, enzyme, lipid, and other components from the cytoplasm into its closed single membrane structure and transfer them to recipient units in an autocrine, paracrine, or endocrine manner. Hypoxia is a state of low oxygen tension and is involved in many pathological processes. Hypoxia influences the size, quantity, and expression of exosome cargos. Exosomes derived from hypoxic tumor cells transfer genetics, proteins, and lipids to the recipient units to exert pleiotropic effects. Different donor cells produce different cargo contents, target different recipient units and lead to different biological effects. Hypoxic exosomes derived from tumor cells uptaken by normoxic tumor cells lead to promoted proliferation, migration, and invasion; uptaken by extracellular space or liver lead to promoted metastasis; uptaken by endothelial cells lead to promoted angiogenesis; uptaken by immune cells lead to promoted macrophage polarization and changed tumor immune microenvironment. In addition to various types of tumors, hypoxic exosomes also participate in the development of diseases in the cardiovascular system, neuron system, respiratory system, hematology system, endocrine system, urinary system, reproduction system, and skeletomuscular system. Understanding the special characteristics of hypoxic exosomes provide new insight into elaborating the pathogenesis of hypoxia related disease. This review summarizes hypoxia induced cargo changes and the biological effects of hypoxic exosomes in tumors and non-malignant diseases in different systems.

Potential roles of exosomal non-coding RNAs in chemoresistance in pancreatic cancer

Pancreatic cancer (PC) is one of the deadliest digestive system tumors in the world, primarily attributed to difficulty in early diagnosis, early metastasis, and insen-sitivity to chemotherapy. The survival of advanced PC patients can be improved by chemotherapy, including gemcitabine, platinum drugs, and 5-fluorouracil, and targeted therapy such as PARP inhibitors. Nevertheless, primary or acquired drug resistance ultimately leads to treatment failure and poor prognosis in patients with PC. The mechanism underlying drug resistance in PC is complex and has not been fully elucidated. Recent studies have indicated that exsomes are the best natural carrier of non-coding RNAs (ncRNAs). They can regulate drug resistance by transporting ncRNAs. Accumulating evidence has demonstrated that exosomal ncRNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), play an crucial role in regulating resistance to chemotherapy drugs in PC. In this review, we systematically focus on the emerging role and regulatory mechanisms of exosomal ncRNAs in influencing chemotherapy resistance in PC. We believe that exosomal ncRNAs can be considered as potential biomarkers for the diagnosis and prognosis of PC as well as new therapeutic targets.

Protein tyrosine phosphatase receptor type Z1 inhibits the cisplatin resistance of ovarian cancer by regulating PI3K/AKT/mTOR signal pathway

Most patients with ovarian cancer (OC) get remission after undergoing cytoreductive surgery and platinum-based standard chemotherapy, but more than 50% of patients with advanced OC relapse within the first 5 years after treatment and develop resistance to standard chemotherapy. The production of medicinal properties is the main reason for the poor prognosis and high mortality of OC patients. Cisplatin (DDP) resistance is a major cause for poor prognosis of OC patients. PTPRZ1 can regulate the growth and apoptosis of ovarian cancer cells, while the molecular mechanism remains unknown. This study was designed to investigate the roles of PTPRZ1 in DDP-resistant OC cells and possible mechanism. PTPRZ1 expression in OC tissues and normal tissues was analyzed by GEPIA database and verified by Real-time Quantitative Reverse Transcription PCR (RT-PCR) assay. PTPRZ1 expression in normal ovarian cancer cells and DDP-resistant OC cells was also analyzed. Subsequently, RT-PCR, Western blot, MTT experiment and flow cytometry were used to assess the effects of PTPRZ1-PI3K/AKT/mTOR regulating axis on DDP resistance of OC. PTPRZ1 expression was abnormally low in OC tissues, and notably reduced in DDP-resistant OC cells. MTT experiment and flow cytometer indicated that overexpression of PTPRZ1 enhanced the DDP sensitivity of OC cells and promoted the cell apoptosis. Moreover, the results of our research showed that PTPRZ1 might exert its biological effects through blocking PI3K/AKT/mTOR pathway. PTPRZ1 overexpression inhibitied OC tumor growth and resistance to DDP in vivo. Overall, PTPRZ1 might suppress the DDP resistance of OC and induce the cytotoxicity by blocking PI3K/AKT/mTOR pathway.