Exosomal miR-196a derived from cancer-associated fibroblasts confers cisplatin resistance in head and neck cancer through targeting CDKN1B and ING5

The diagnostic and prognostic values of microRNA-196a in cancer

MicroRNA-196a (miR-196a) was previously reported to be up-regulated in cancers, and it has the diagnostic and prognostic values in cancers. Whereas, the conclusion was still unclear according to the published data. To assess such roles of miR-196a in cancers, the present study was conducted based on published data and online cancer-related databases. To identify the relevant published data, we searched articles in databases and then the relevant data were extracted to evaluate the correlation between miR-196a expression and diagnosis, prognosis for cancer patients. The pooled results showed that miR-196a was a valuable diagnostic biomarker in cancer (area under curve (AUC) = 0.87, 95% CI: 0.84–0.90; sensitivity (SEN) = 0.73, 95% CI: 0.64–0.81; specificity (SPE) = 0.90, 95% CI: 0.81–0.95), which was consistent with the data from databases (breast cancer: miR-196a-3p: AUC = 0.77, 95% CI: 0.74–0.79; miR-196a-5p: AUC = 0.71, 95% CI: 0.66–0.75; pancreatic cancer: miR-196a-3p: AUC = 0.80, 95% CI: 0.73–0.87; miR-196a-5p: AUC = 0.61, 95% CI: 0.51–0.71). In addition, the pooled result revealed that elevated miR-196a expression in tumor tissues (HR = 2.54, 95% CI: 1.79–3.61, P_{Heterogeneity}=0.000, I² = 75.8%) or serum/plasma (HR = 4.06, 95% CI: 2.67–6.18, P_{Heterogeneity}=0.668, I² = 0%) of patients was an unfavorable survival biomarker, which was consistent with the data from databases (adrenocortical carcinoma: HR = 5.70; esophageal carcinoma: HR = 1.93; brain lower grade glioma: HR = 2.91; GSE40267: HR = 2.47, 95% CI: 1.2–5.07; TCGA: HR = 1.82, 95% CI: 1.21–2.74; GSE19783: HR = 4.24, 95% CI: 1–18.06). In short, our results demonstrated that miR-196a in tumor tissue or serum/plasma could be used as a prognostic and diagnostic values for cancers.

Potential roles and prognostic significance of exosomes in cancer drug resistance

Drug resistance is a major impediment in cancer therapy which strongly reduces the efficiency of anti-cancer drugs. Exosomes are extracellular vesicles with cup or spherical shape with a size range of 40-150 nm released by eukaryotic cells that contain genetic materials, proteins, and lipids which mediate a specific cell-to-cell communication. The potential roles of exosomes in intrinsic and acquired drug resistance have been reported in several studies. Furthermore, a line of evidence suggested that the content of exosomes released from tumor cells in biological samples may be associated with the clinical outcomes of cancer patients. In this review, we highlighted the recent studies regarding the potential roles of exosomes in tumor initiation, progression, and chemoresistance. This study suggests the possible role of exosomes for drug delivery and their contents in prognosis and resistance to chemotherapy in cancer patients.

Blockade of deubiquitinating enzyme PSMD14 overcomes chemoresistance in head and neck squamous cell carcinoma by antagonizing E2F1/Akt/SOX2-mediated stemness

Increasing evidence reveals a close relationship between deubiquitinating enzymes (DUBs) and cancer progression. In this study, we attempted to identify the roles and mechanisms of critical DUBs in head and neck squamous cell carcinoma (HNSCC).

Methods: Bioinformatics analysis was performed to screen differentially expressed novel DUBs in HNSCC. Immunohistochemistry assay was used to measure the expression of DUB PSMD14 in HNSCC specimens and adjacent normal tissues. The level of PSMD14 in HNSCC tumorigenesis was investigated using a 4-NQO-induced murine HNSCC model. The function of PSMD14 was determined through loss-of-function assays. Chromatin immunoprecipitation, immunoprecipitation and in vivo ubiquitination assay were conducted to explore the potential mechanism of PSMD14. The anti-tumor activity of PSMD14 inhibitor Thiolutin was assessed by in vitro and in vivo experiments.

Results: We identified PSMD14 as one of significantly upregulated DUBs in HNSCC tissues. Aberrant expression of PSMD14 was associated with tumorigenesis and malignant progression of HNSCC and further indicated poor prognosis. The results of in vitro and in vivo experiments demonstrated PSMD14 depletion significantly undermined HNSCC growth, chemoresistance and stemness. Mechanically, PSMD14 inhibited the ubiquitination and degradation of E2F1 to improve the activation of Akt pathway and the transcription of SOX2. Furthermore, PSMD14 inhibitor Thiolutin exhibited a potent anti-tumor effect on HNSCC in vivo and in vitro by impairing DUB activity of PSMD14.

Conclusion: Our findings demonstrate the role and mechanism of PSMD14 in HNSCC, and provide a novel and promising target for diagnosis and clinical therapy of HNSCC.

HNC0014, a Multi-Targeted Small-Molecule, Inhibits Head and Neck Squamous Cell Carcinoma by Suppressing c-Met/STAT3/CD44/PD-L1 Oncoimmune Signature and Eliciting Antitumor Immune Responses

Simple Summary

Cancer stem cells (CSCs) in head and neck squamous cell carcinoma (HNSCC) possess unlimited self-renewal capacity, resist treatments and induce tumor repopulation after interventions. Here, we observed HNSCC CSCs secreted exosomes containing c-Met, STAT3 (also the phosphorylated form of c-Met and STAT3), CD44, and PD-L1 oncogenic signaling molecules. CSC-derived exosomes, in part, transform fibroblasts (NFs) into cancer-associated fibroblasts (CAFs), establish drug resistance, and an immune-evasive tumor microenvironment (TME). We demonstrated HNC0014, a novel small-molecule drug, suppresses HNSCC tumorigenesis, CSC generation and prevents CAF transformation by decreasing the aforementioned oncogenic signaling molecules’ expression in both HNSCC cells and CSC-derived exosomes.

Abstract

Despite advancements in diagnostic and standard treatment modalities, including surgery, radiotherapy, and chemotherapy, overall survival rates of advanced-stage head and neck squamous cell carcinoma (HNSCC) patients have remained stagnant for over three decades. Failure of these treatment modalities, coupled with post-therapy complications, underscores the need for alternative interventions and an in-depth understanding of the complex signaling networks involved in developing treatment resistance. Using bioinformatics tools, we identified an increased expression of c-Met, STAT3, and CD44 corresponding to a poor prognosis and malignant phenotype of HNSCC. Subsequently, we showed that tumorsphere-derived exosomes promoted cisplatin (CDDP) resistance and colony and tumorsphere formation in parental HNSCC cells, accompanied by an increased level of oncogenic/immune evasive markers, namely, c-Met, STAT3, CD44, and PD-L1. We then evaluated the therapeutic potential of a new small molecule, HNC0014. The molecular docking analysis suggested strong interactions between HNC0014 and oncogenic molecules; c-Met, STAT3, CD44, and PD-L1. Subsequently, we demonstrated that HNC0014 treatment suppressed HNSCC tumorigenic and expression of stemness markers; HNC0014 also reduced cancer-associated fibroblast (CAF) transformation by Exo^sp- and CAF-induced tumorigenic properties. HNC0014 treatment alone suppressed tumor growth in a cisplatin-resistant (SAS tumorspheres) mouse xenograft model and with higher inhibitory efficacy when combined with CDDP. More importantly, HNC0014 treatment significantly delayed tumor growth in a syngeneic mouse HNSCC model, elicited an antitumor immune profile, and reduced the total c-Met, STAT3, and their phosphorylated forms, PD-L1 and CD44, contents in serum exosomes. Collectively, our findings provide supports for HNC0014 as a multi-targeted immunotherapeutic lead compound for further development.

Loss of exosomal miR-146a-5p from cancer-associated fibroblasts after androgen deprivation therapy contributes to prostate cancer metastasis

Background

Androgen deprivation therapy (ADT) is the backbone of therapy for advanced prostate cancer (PCa). Despite the good initial response, castration resistance and metastatic progression will inevitably occur. Cancer-associated fibroblasts (CAFs) may be implicated in promoting metastasis of PCa after ADT. Our aim is to investigate the role and mechanism of CAFs-derived exosomes involving in metastasis of PCa after ADT.

Methods

PCa cells were co-cultured with exosomes derived from 10 nM dihydrotestosterone (DHT)-treated (simulating the high androgen level of prostate cancer microenvironment) or ethanol (ETOH) -treated (simulating the castration level of prostate cancer microenvironment after ADT) CAFs, and their migration and invasion differences under castration condition were examined both in vitro and in vivo. The miRNA profiles of exosomes derived from DHT-treated CAFs and matched ETOH-treated CAFs were analysed via next generation sequencing. The transfer of exosomal miR-146a-5p from CAFs to PCa cells was identified by fluorescent microscopy. The function and direct target gene of exosomal miR-146a-5p in PCa cells were confirmed through Transwell assays, luciferase reporter, and western blot.

Results

Compared with DHT-treated CAFs, exosomes derived from ETOH-treated CAFs dramatically increased migration and invasion of PCa cells under castration condition. MiR-146a-5p level in exosomes from ETOH-treated CAFs was significantly reduced. The loss of miR-146a-5p may strengthen the epithelial-mesenchymal transition (EMT) to accelerate cancer cells metastasis by modulating epidermal growth factor receptor (EGFR)/ERK pathway.

Conclusions

CAFs-derived exosomal miR-146a-5p confers metastasis in PCa cells under ADT through the EGFR/ERK pathway and it may present a new treatment for PCa.

Exosomes: Emerging Diagnostic and Therapeutic Targets in Cutaneous Diseases

Skin is the largest human organ and is continuously exposed to various exogenous and endogenous trigger factors affecting body homeostasis. A number of mechanisms, including genetic, inflammatory and autoimmune ones, have been implicated in the pathogenesis of cutaneous diseases. Recently, there has been considerable interest in the role that extracellular vesicles, particularly exosomes, play in human diseases, through their modulation of multiple signaling pathways. Exosomes are nano-sized vesicles secreted by all cell types. They function as cargo carriers shuttling proteins, nucleic acids, lipids etc., thus impacting the cell-cell communications and transfer of vital information/moieties critical for skin homeostasis and disease pathogenesis. This review summarizes the available knowledge on how exosomes affect pathogenesis of cutaneous diseases, and highlights their potential as future targets for the therapy of various skin diseases.

The roles of exosomes in cancer drug resistance and its therapeutic application

Exosomes are a category of extracellular vesicles with a size ranging from 40 to 160 nm, which can be secreted by multiple cells in the tumor microenvironment. Exosomes serve as communicators in regulating biological functions and pathological processes, including drug response. Through transporting the cargo such as protein or nucleic acid, exosomes can modulate drug sensitivity via multiple mechanisms. Additionally, exosomes can be deployed as a delivery system to treat cancer due to their high-efficient loading capacity and tolerable toxicity. Recent studies have demonstrated the high efficacy of exosomes in cancer therapy. Herein, we conduct this review to summarize the mechanism of exosome-mediated drug resistance and the therapeutic potential of exosomes in cancer.

Loss of microRNA-30e induced by extracellular vesicles from cancer-associated fibroblasts promotes breast cancer progression by binding to CTHRC1

Breast cancer (BC) is a frequently occurring malignancy within female population. Recently, the significance of extracellular vesicles (EVs) derived from cancer-associated fibroblasts (CAF) (CAF-EVs) in malignancies has been increasingly recognized. The study aims to explore the functional mechanism of CAF-EVs in the development of BC. Initially, EVs were isolated from CAF, followed by observation on morphological change using transmission electronic microscope. Next, BC and the adjacent normal tissues were collected for quantification of microRNA (miR)-30e and collagen triple helix repeat containing 1 (CTHRC1) using RT-qPCR and Western blot analysis. miR-30e was downregulated in BC, while CTHRC1 was upregulated. Luciferase assay revealed that miR-30e targeted CTHRC1. miR-30e and CTHRC1 expression was altered to evaluate their effects on BC cell viabilities in vitro. It was shown that overexpression of miR-30e or silencing of CTHRC1 suppressed proliferation, migration/invasion of BC cells but promoted apoptosis. Xenograft tumors were developed in mice to observe the tumorigenesis. To sum up, CAF-EVs reduced miR-30e expression to upregulate CTHRC1, which aggravated BC in vitro and in vivo.

The promising role of noncoding RNAs in cancer-associated fibroblasts: an overview of current status and future perspectives

As the most important component of the stromal cell population in the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) are crucial players in tumor initiation and progression. The interaction between CAFs and tumor cells, as well as the resulting effect, is much greater than initially expected. Numerous studies have shown that noncoding RNAs (ncRNAs) play an irreplaceable role in this interplay, and related evidence continues to emerge and advance. Under the action of ncRNAs, normal fibroblasts are directly or indirectly activated into CAFs, and their metabolic characteristics are changed; thus, CAFs can more effectively promote tumor progression. Moreover, via ncRNAs, activated CAFs can affect the gene expression and secretory characteristics of cells, alter the TME and enhance malignant biological processes in tumor cells to contribute to tumor promotion. Previously, ncRNA dysregulation was considered the main mechanism by which ncRNAs participate in the crosstalk between CAFs and tumor cells. Recently, however, exosomes containing ncRNAs have been identified as another vital mode of interaction between these two types of cells, with a more direct and clear function. Gaining an in-depth understanding of ncRNAs in CAFs and the complex regulatory network connecting CAFs with tumor cells might help us to establish more effective and safer approaches for cancer therapies targeting ncRNAs and CAFs and offer new hope for cancer patients.

Exosomal miR-590-3p derived from cancer-associated fibroblasts confers radioresistance in colorectal cancer

Radiotherapeutic resistance is a major obstacle for the effective treatment of colorectal cancer (CRC). MicroRNAs (miRNAs) play a critical role in chemoresistance and radioresistance. Here, we aimed to investigate whether miR-590-3p participates in the radioresistance of CRC. High expression of miR-590-3p and low expression of CLCA4 were found in both CRC tissues and cell lines. CLCA4 was indicated to be a target gene of miR-590-3p. CAF-derived exosomes were extracted and co-cultured with CRC cells, which were then exposed to radiation. CRC cells were transfected with plasmids and injected into nude mice to detect the in vivo effect of CAF-derived exosomes. Treatment with CAF-derived exosomes decreased the sensitivity of CRC cells to radiation. CAF-derived exosomes overexpressing miR-590-3p increased cell survival and the ratio of p-PI3K/PI3K and p-AKT/AKT while lowering the expressions of cleaved-PARP, cleaved-caspase 3, and γH2AX in cells. Furthermore, in vivo experimental results confirmed that CAF-derived exosomal miR-590-3p stimulated tumor growth in mice following radiotherapy. Our results demonstrate that miR-590-3p delivery via exosomes derived from CAFs enhances radioresistance in CRC through the positive regulation of the CLCA4-dependent PI3K/Akt signaling pathway.

PGRN-/- TAMs-derived exosomes inhibit breast cancer cell invasion and migration and its mechanism exploration

Breast cancer is one of the most malignant diseases world-wide and ranks the first among female cancers. Progranulin (PGRN) plays a carcinogenic role in breast cancer, but its mechanisms are not clear. In addition, there are few reports on the relationship between PGRN and tumor-associated macrophages (TAMs).

AIMS

To investigate the effects of exosomes derived from PGRN^-/- TAMs on invasion and migration of breast cancer cells.

MAIN METHODS

Mouse breast cancer xenograft model was constructed to explore the effect of PGRN^-/- tumor environment (TME) on breast cancer. Flow cytometry was used to compare TAMs of wild type (WT) and PGRN^-/- tumor tissue. Transwell assay, wound healing assay and western blot were used to explore the effect of WT and PGRN^-/- TAMs and their exosomes on invasion, migration and epithelial-mesenchymal transition (EMT) of breast cancer cells. MicroRNA (miRNA) assay was used to find out the differentially expressed miRNA of negative control (NC) and siPGRN-TAMs exosomes. Quantitative PCR and luciferase report assay were used to explore the target gene.

KEY FINDINGS

The lung metastasis of breast cancer of PGRN^-/- mice was inhibited. PGRN^-/- TAMs inhibited invasion, migration and EMT of breast cancer cells through their exosomes. MiR-5100 of PGRN^-/- TAMs-derived exosomes was up-regulated, which might regulate expression of CXCL12, thereby inhibiting the CXCL12/CXCR4 axis, and ultimately inhibiting the invasion, migration and EMT of breast cancer cells.

SIGNIFICANCE

Our study elucidates a new molecular mechanism of lung metastasis of breast cancer, so it may contribute to efficient prevention and therapeutic strategies.

Exosomal cargoes in OSCC: current findings and potential functions

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy in head and neck cancer, with high recurrence and mortality. Early diagnosis and efficient therapeutic strategies are vital for the treatment of OSCC patients. Exosomes can be isolated from a broad range of different cell types, implicating them as important factors in the regulation of human physiological and pathological processes. Due to their abundant cargo including proteins, lipids, and nucleic acids, exosomes have played a valuable diagnostic and therapeutic role across multiple diseases, including cancer. In this review, we summarize recent findings concerning the content within and participation of exosomes relating to OSCC and their roles in tumorigenesis, proliferation, migration, invasion, metastasis, and chemoresistance. We conclude this review by looking ahead to their potential utility in providing new methods for treating OSCC to inspire further research in this field.

CD63+ Cancer-Associated Fibroblasts Confer Tamoxifen Resistance to Breast Cancer Cells through Exosomal miR-22

Tamoxifen remains the most effective treatment for estrogen receptor α (ERα)-positive breast cancer. However, many patients still develop resistance to tamoxifen in association with metastatic recurrence, which presents a tremendous clinical challenge. To better understand tamoxifen resistance from the perspective of the tumor microenvironment, the whole microenvironment landscape is charted by single-cell RNA sequencing and a new cancer-associated fibroblast (CAF) subset, CD63+ CAFs, is identified that promotes tamoxifen resistance in breast cancer. Furthermore, it is discovered that CD63+ CAFs secrete exosomes rich in miR-22, which can bind its targets, ERα and PTEN, to confer tamoxifen resistance on breast cancer cells. Additionally, it is found that the packaging of miR-22 into CD63+ CAF-derived exosomes is mediated by SFRS1. Furthermore, CD63 induces STAT3 activation to maintain the phenotype and function of CD63+ CAFs. Most importantly, the pharmacological blockade of CD63+ CAFs with a CD63-neutralizing antibody or cRGD-miR-22-sponge nanoparticles enhances the therapeutic effect of tamoxifen in breast cancer. In summary, the study reveals a novel subset of CD63+ CAFs that induces tamoxifen resistance in breast cancer via exosomal miR-22, suggesting that CD63+ CAFs may be a novel therapeutic target to enhance tamoxifen sensitivity.

MiR-196: emerging of a new potential therapeutic target and biomarker in colorectal cancer

Deregulation of microRNAs, as key elements in colorectal cancer (CRC) pathogenesis, is correlated with various stages of this cancer. miR-196 is involved in the initiation and progression of a verity of malignances, especially CRC. miR-196 in CRC cells could target different types of genes with oncogenic and/or tumor suppressor function such as HOX genes, GATA6, SOCS1, SOCS3, ANXA1, DFFA, PDCD4, ZG16 and ING5. Therefore, these genes could be up or down-regulated in cells and subsequently change the capacity of CRC cells in terms of tumor development, progression and, response to therapy. Comprehension of miR-196-associated aberrations underlying the CRC pathogenesis might introduce promising targets for therapy. Additionally, it seems that miR-196 expression profiling, especially circulatory exosomal miR-196, might be useful for diagnosis and prognosis determination of the CRC patients. In this review, at first, we summarize the roles of miR-196 in different types of cancers. After that, a detailed discussion about this miRNA and also their targets in CRC pathogenesis, progression, and response to treatment are represented. Moreover, we highlight the potential utilization of miR-196 and its targets as therapeutic targets and novel biomarkers in early detection and prediction of prognosis in CRC patients.

Cancer-associated fibroblasts-derived exosomal miR-17-5p promotes colorectal cancer aggressive phenotype by initiating a RUNX3/MYC/TGF-β1 positive feedback loop

Cancer-associated fibroblasts (CAFs) are the main stromal cells in the tumour microenvironment (TME). We found that the distribution of CAFs was significantly increased with tumour progression and led to a poor prognosis. In vitro and in vivo assays revealed that CAFs enhanced colorectal cancer (CRC) metastasis. Based on extraction and identification of exosomes of CAFs and normal fibroblasts (NFs), CAFs-exo showed higher expression of miR-17-5p than NFs-exo and could deliver exosomal miR-17-5p from parental CAFs to CRC cells. Further exploration verified that miR-17-5p influenced CRC metastasis capacity and directly targeted 3'-untranslated regions (UTRs) of RUNX family transcription factor 3(RUNX3). Our findings further revealed that RUNX3 interacted with MYC proto-oncogene(MYC) and that both RUNX3 and MYC bound to the promoter of transforming growth factor beta1(TGF-β1) at base pairs 1005-1296, thereby activating the TGF-β signalling pathway and contributing to tumour progression. In addition, RUNX3/MYC/TGF-β1 signalling sustained autocrine TGF-β1 to activate CAFs, and activated CAFs released more exosomal miR-17-5p to CRC cells, forming a positive feedback loop for CRC progression. Taken together, these data provide a new understanding of the potential diagnostic value of exosomal miR-17-5p in CRC.

Portrait of a CAF: The story of cancer-associated fibroblasts in head and neck cancer

Complex interactions take place during cancer formation and progression. In this regard, there has been increasing focus on the non-malignant cells that make up the tumour microenvironment (TME), and how they interact with malignant tumour cells. TME is highly heterogeneous and has a major influence on tumour behaviour and therapy response. Cancer-associated fibroblasts (CAFs), one of the main components of the TME, establish dangerous liaisons with cancer cells and other components of the TME to shape a tumour-supportive environment in many types of cancer. Head and neck squamous cell carcinoma (HNSCC) encompass the malignant neoplasms arising from the mucosal lining of the oral cavity, pharynx and larynx. The TME of HNSCC contributes to tumour progression and this stromal compartment may be an interesting target for treatment. There is an emerging picture of the behaviour of CAFs in HNSCC; how they affect and are affected by the TME. We aim to summarise and discuss the current understanding of CAFs in head and neck cancer, exploring CAF activation and heterogeneity, and interaction with cancer cells and other cells within the TME.

Extracellular Vesicles as Biomarkers in Cancer Immunotherapy

Simple Summary

Extracellular vesicles (EVs) are small particles found throughout the body. EVs are released by living cells and contain cargo representing the cell of origin. In recent years, EVs have gained attention in cancer research. Since the cargo found inside EVs can be traced back to the cell of origin, EVs shed from cancer cells, in particular, may be used to better describe and characterize a patient’s tumor. EVs have been found and isolated from a variety of bodily fluids, including blood, saliva, and amniotic fluid, and therefore offer a non-invasive way of also diagnosing and monitoring patients before, during, and after cancer immunotherapy. The aim of this review article was to summarize some of the recent work conducted in this field and the challenges we face moving forward in utilizing EVs for cancer diagnostic and therapeutic purposes in cancer immunotherapy in the clinical setting.

Abstract

Extracellular vesicles (EVs), including exosomes and microvesicles, are membrane-bound vesicles secreted by most cell types during both physiologic conditions as well in response to cellular stress. EVs play an important role in intercellular communication and are emerging as key players in tumor immunology. Tumor-derived EVs (TDEs) harbor a diverse array of tumor neoantigens and contain unique molecular signature that is reflective of tumor’s underlying genetic complexity. As such they offer a glimpse into the immune tumor microenvironment (TME) and have the potential to be a novel, minimally invasive biomarker for cancer immunotherapy. Immune checkpoint inhibitors (ICI), such as anti- programmed death-1(PD-1) and its ligand (PD-L1) antibodies, have revolutionized the treatment of a wide variety of solid tumors including head and neck squamous cell carcinoma, urothelial carcinoma, melanoma, non-small cell lung cancer, and others. Typically, an invasive tissue biopsy is required both for histologic diagnosis and next-generation sequencing efforts; the latter have become more widespread in daily clinical practice. There is an unmet need for noninvasive or minimally invasive (e.g., plasma-based) biomarkers both for diagnosis and treatment monitoring. Targeted analysis of EVs in biospecimens, such as plasma and saliva could serve this purpose by potentially obviating the need for tissue sample. In this review, we describe the current challenges of biomarkers in cancer immunotherapy as well as the mechanistic role of TDEs in modulating antitumor immune response.

Epitranscriptomics and epiproteomics in cancer drug resistance: therapeutic implications

Drug resistance is a major hurdle in cancer treatment and a key cause of poor prognosis. Epitranscriptomics and epiproteomics are crucial in cell proliferation, migration, invasion, and epithelial–mesenchymal transition. In recent years, epitranscriptomic and epiproteomic modification has been investigated on their roles in overcoming drug resistance. In this review article, we summarized the recent progress in overcoming cancer drug resistance in three novel aspects: (i) mRNA modification, which includes alternative splicing, A-to-I modification and mRNA methylation; (ii) noncoding RNAs modification, which involves miRNAs, lncRNAs, and circRNAs; and (iii) posttranslational modification on molecules encompasses drug inactivation/efflux, drug target modifications, DNA damage repair, cell death resistance, EMT, and metastasis. In addition, we discussed the therapeutic implications of targeting some classical chemotherapeutic drugs such as cisplatin, 5-fluorouridine, and gefitinib via these modifications. Taken together, this review highlights the importance of epitranscriptomic and epiproteomic modification in cancer drug resistance and provides new insights on potential therapeutic targets to reverse cancer drug resistance.

The potential role of tumor-derived exosomes in diagnosis, prognosis, and response to therapy in cancer

INTRODUCTION

Small extracellular vesicles (sEV) produced by tumors and called TEX mediate communication and regulate the tumor microenvironment. As a 'liquid tumor biopsy' and with the ability to induce pro-tumor reprogramming, TEX offer a promising approach to monitoring cancer progression or response to therapy.

AREAS COVERED

TEX isolation from body fluids and separation by immunoaffinity capture from other EVs enables TEX molecular and functional characterization in vitro and in vivo. TEX carry membrane-bound PD-L1 and a rich cargo of other proteins and nucleic acids that reflect the tumor content and activity. TEX transfer this cargo to recipient cells, activating various molecular pathways and inducing pro-tumor transcriptional changes. TEX may interfere with immune therapies, and TEX plasma levels correlate with patients' responses to therapy. TEX induce local and systemic alterations in immune cells which may have a prognostic value.

EXPERT OPINION

TEX have a special advantage as potential cancer biomarkers. Their cargo emerges as a correlate of developing or progressing malignant disease; their phenotype mimics that of the tumor; and their functional reprogramming of immune cells provides a reading of the patients' immune status prior and post immunotherapy. Validation of TEX and T-cell-derived sEV as cancer biomarkers is an impending future task.

miR-196a-mediated downregulation of p27kip1 protein promotes prostate cancer proliferation and relates to biochemical recurrence after radical prostatectomy

BACKGROUND

Dysregulation of microRNAs has performed vital gene regulatory functions in the genesis, progression, and prognosis of multiple malignant tumors. This study aimed to elucidate the regulatory mechanism of miR-196a in prostate cancer (PCa) and explore its clinical significance.

METHODS

Quantitative real-time polymerase chain reaction was implemented to examine miR-196a and p27^kip1 messenger RNA expression in PCa. Cell proliferation was evaluated via Cell Counting Kit-8, colony formation, and nude mouse tumorigenicity assays. Luciferase reporter assay was applied to identify target genes. p27^kip1 protein expression in PCa was investigated using Western blot analysis and immunohistochemistry.

RESULTS

There was a dramatic upregulation of miR-196a in PCa. Upregulated miR-196a was related to worse Gleason score (GS), later pathological stage, and poor biochemical recurrence (BCR)-free survival. In vivo and in vitro experiments exhibited that miR-196a promoted PCa proliferation and expedited G1/S-phase progression through the downregulation of p27^kip1 protein. Additionally, p27^kip1 protein was distinctly downregulated in PCa. Low p27^kip1 protein expression had a strong correlation with increased GS and was an independent predictor of BCR after radical prostatectomy (RP).

CONCLUSIONS

Excessive expression of miR-196a and subsequent downregulation of p27^kip1 protein play essential roles in promoting PCa proliferation and leading to BCR after RP. miR-196a and its target p27^kip1 may become novel molecular biomarkers and therapeutic targets for PCa.

Exosomal lncRNA UCA1 from cancer-associated fibroblasts enhances chemoresistance in vulvar squamous cell carcinoma cells

AIM

In the current work, we aimed to explore whether Cancer-associated fibroblasts (CAF) exosomes played crucial roles in vulvar squamous cell carcinoma (VSCC) chemoresistance via mediating long noncoding RNAs (lncRNA).

METHODS

The IC50 value and cell apoptosis were assessed by the Cell Counting-8 Kit (CCK-8) assay and flow cytometry, respectively. Western blot analysis was used for the measurement of protein levels. The levels of urothelial cancer-associated 1 (UCA1), miR-103a and WEE1 G2 checkpoint kinase (WEE1) mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The target relationships among miR-103a, UCA1 and WEE1 were confirmed by dual-luciferase reporter assays. Xenograft model mice were established to observe the impact of exosomal UCA1 on cisplatin (CDDP) resistance in vivo.

RESULTS

Our data indicated that CAF enhanced CDDP resistance of VSCC cells in vitro. Extracellular UCA1 was transferred by exosomes derived from CAF. Exosomal UCA1 derived from CAF conferred VSCC cell resistance to CDDP. Moreover, UCA1 functioned as a miR-103a sponge in VSCC cells. The promotion of exosomal UCA1 on VSCC cell resistance to CDDP was mediated by miR-103a. WEE1 was a direct target of miR-103a, and exosomal miR-103a from CAF weakened CDDP resistance of VSCC cells by WEE1. Furthermore, exosomal UCA1 regulated WEE1 expression through sponging miR-103a. Additionally, exosomal UCA1 enhanced tumor growth and CDDP resistance in vivo.

CONCLUSION

Our findings suggested exosomal UCA1 derived from CAF conferred VSCC cell resistance to CDDP in vitro and in vivo at least partly through the miR-103a/WEE1 axis, highlighting a novel therapeutic method for improving the clinical benefits of CDDP chemotherapy in VSCC patients.

Extracellular Vesicle-Based Communication May Contribute to the Co-Evolution of Cancer Stem Cells and Cancer-Associated Fibroblasts in Anti-Cancer Therapy

Analogously to the natural selective forces in ecosystems, therapies impose selective pressure on cancer cells within tumors. Some tumor cells can adapt to this stress and are able to form resistant subpopulations, parallel with enrichment of cancer stem cell properties in the residual tumor masses. However, these therapy-resistant cells are unlikely to be sufficient for the fast tumor repopulation and regrowth by themselves. The dynamic and coordinated plasticity of residual tumor cells is essential both for the conversion of their regulatory network and for the stromal microenvironment to produce cancer supporting signals. In this nursing tissue "niche", cancer-associated fibroblasts are known to play crucial roles in developing therapy resistance and survival of residual stem-like cells. As paracrine messengers, extracellular vesicles carrying a wide range of signaling molecules with oncogenic potential, can support the escape of some tumor cells from their deadly fate. Here, we briefly overview how extracellular vesicle signaling between fibroblasts and cancer cells including cancer progenitor/stem cells may contribute to the progression, therapy resistance and recurrence of malignant tumors.

Global targetome analysis reveals critical role of miR-29a in pancreatic stellate cell mediated regulation of PDAC tumor microenvironment

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive forms of malignancies with a nearly equal incidence and mortality rates in patients. Pancreatic stellate cells (PSCs) are critical players in PDAC microenvironment to promote the aggressiveness and pathogenesis of the disease. Dysregulation of microRNAs (miRNAs) have been shown to play a significant role in progression of PDAC. Earlier, we observed a PSC-specific downregulation of miR-29a in PDAC pancreas, however, the mechanism of action of the molecule in PSCs is still to be elucidated. The current study aims to clarify the regulation of miR-29a in PSCs and identifies functionally important downstream targets that contribute to tumorigenic activities during PDAC progression.

METHODS

In this study, using RNAseq approach, we performed transcriptome analysis of paired miR-29a overexpressing and control human PSCs (hPSCs). Enrichment analysis was performed with the identified differentially expressed genes (DEGs). miR-29a targets in the dataset were identified, which were utilized to create network interactions. Western blots were performed with the top miR-29a candidate targets in hPSCs transfected with miR-29a mimic or scramble control.

RESULTS

RNAseq analysis identified 202 differentially expressed genes, which included 19 downregulated direct miR-29a targets. Translational repression of eight key pro-tumorigenic and -fibrotic targets namely IGF-1, COL5A3, CLDN1, E2F7, MYBL2, ITGA6 and ADAMTS2 by miR-29a was observed in PSCs. Using pathway analysis, we find that miR-29a modulates effectors of IGF-1-p53 signaling in PSCs that may hinder carcinogenesis. We further observe a regulatory role of the molecule in pathways associated with PDAC ECM remodeling and tumor-stromal crosstalk, such as INS/IGF-1, RAS/MAPK, laminin interactions and collagen biosynthesis.

CONCLUSIONS

Together, our study presents a comprehensive understanding of miR-29a regulation of PSCs, and identifies essential pathways associated with PSC-mediated PDAC pathogenesis. The findings suggest an anti-tumorigenic role of miR-29a in the context of PSC-cancer cell crosstalk and advocates for the potential of the molecule in PDAC targeted therapies.

Exosomal Noncoding RNAs and Tumor Drug Resistance

Tumor drug resistance is a major challenge in the treatment of cancer. Noncoding RNAs (ncRNA) play a role in the progression of drug resistance. Recent studies have indicated that exosomes, with their in vitro and in vivo compatibility, are the best natural carrier of ncRNA, and their transport of ncRNA into cells could regulate drug resistance. Exosomal ncRNA impact drug resistance through participation in drug efflux, regulation of signaling pathways, and modification of the tumor microenvironment. In this review, we evaluate the mechanism of exosomal ncRNA related to tumor drug resistance, their role in different tumors, and potential clinical applications.

Extracellular Vesicles from Cancer-Associated Fibroblasts Containing Annexin A6 Induces FAK-YAP Activation by Stabilizing β1 Integrin, Enhancing Drug Resistance

Extracellular vesicles (EV) from cancer-associated fibroblasts (CAF) are composed of diverse payloads. Although CAFs impact the aggressive characteristics of gastric cancer cells, the contribution of CAF-EV to gastric cancer progression has not been elucidated. Here, we investigated the molecular mechanism of the changes in gastric cancer characteristics induced by CAF-EV. CAF abundance in gastric cancer tissues was associated with poor prognosis of patients with gastric cancer receiving chemotherapy. Moreover, CAF-EV induced tubular network formation and drug resistance of gastric cancer cells in the extracellular matrix (ECM). Comprehensive proteomic analysis of CAF-EV identified that Annexin A6 plays a pivotal role in network formation and drug resistance of gastric cancer cells in the ECM via activation of β1 integrin-focal adhesion kinase (FAK)-YAP. A peritoneal metastasis mouse model revealed that CAF-EV induced drug resistance in peritoneal tumors, and inhibition of FAK or YAP efficiently attenuated gastric cancer drug resistance in vitro and in vivo. These findings demonstrate that drug resistance is conferred by Annexin A6 in CAF-EV and provide a potential avenue for overcoming gastric cancer drug resistance through the inhibition of FAK-YAP signaling in combination with conventional chemotherapeutics. SIGNIFICANCE: This study elucidates a novel molecular mechanism through which Annexin A6 in CAF-EV activates FAK-YAP by stabilizing β1 integrin at the cell surface of gastric cancer cells and subsequently induces drug resistance. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/16/3222/F1.large.jpg.

Exosomes released from M2 macrophages transfer miR-221-3p contributed to EOC progression through targeting CDKN1B

In contrast to other solid tumors within the abdominal cavity, epithelial ovarian cancers (EOCs) tend to undergo peritoneal metastasis. Thus, the peritoneal immune microenvironment is crucial for EOC progression. Previous reports indicate that the main immune cells within the peritoneum are M2 macrophages, specifically tumor‐associated macrophages (TAMs). The communication between TAMs and tumor cells plays an important role in EOC development, and exosomes, acting as micro–message carriers, occupy an essential position in this process. Microarray analyses of exosomes revealed that miR‐221‐3p was enriched in M2 exosomes. Furthermore, miR‐221‐3p suppressed cyclin‐dependent kinase inhibitor 1B (CDKN1B) directly. Thus, miR‐221‐3p contributed to the proliferation and G1/S transition of EOC cells. Additionally, low levels of CDKN1B were associated with EOC progression and poor prognosis. These observations suggest that TAMs‐derived exosomal miR‐221‐3p acts as a regulator of EOC progression by targeting CDKN1B. The results of this study confirm that certain exosomal microRNAs may provide novel diagnostic biomarkers and therapeutic targets for EOC.

Exosomal MiR-500a-3p promotes cisplatin resistance and stemness via negatively regulating FBXW7 in gastric cancer

Chemoresistance has been a major challenge in advanced gastric cancer (GC) therapy. Exosomal transfer of oncogenic miRNAs implicates important effects in mediating recipient cell chemoresistance by transmitting active molecules. In this study, we found that microRNA‐500a‐3p was highly expressed in cisplatin (DDP) resistant GC cells (MGC803/DDP and MKN45/DDP) and their secreted exosomes than that in the corresponding parental cells. MGC803/DDP‐derived exosomes enhance DDP resistance and stemness properties of MGC803 recipient cells via exosomal delivery of miR‐500a‐3p in vitro and in vivo through targeting FBXW7. However, reintroduction of FBXW7 in MGC803 cells reverses miR‐500a‐3p‐mediated DDP resistance as well as stemness properties. Furthermore, elevated miR‐500a‐3p in the plasma exosomes of GC patients is correlated with DDP resistance and thereby results in poor progression‐free prognosis. Our finding highlights the potential of exosomal miR‐500a‐3p as an potential modality for the prediction and treatment of GC with chemoresistance.

The Regulatory Role of circRNA_101308 in Cervical Cancer and the Prediction of Its Mechanism

Purpose

Accumulating evidence indicates that circular RNAs (circRNAs) are closely involved in canceration and cancer progression. However, the role of circRNAs in cervical cancer (CC) is largely unknown. Here, we characterized the role of circRNA_101308 in CC.

Materials and Methods

The expression of circRNA_101308 in CC tissues was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Then, circRNA_101308 was overexpressed in CC cells to detect its function by proliferation and apoptosis assays, Transwell assays and animal experiments. The potential mechanism of circRNA_101308 in CC was explored by RNA pull-down, Gene Ontology (GO) and pathway analyses.

Results

CircRNA_101308 was significantly downregulated in CC tissues. The level of circRNA_101308 was much lower in CC patients with lymph node metastasis or deep myometrial invasion compared to those patients without lymph node metastasis and superficial myometrial invasion. CircRNA_101308 overexpression inhibited CC cell proliferation, invasion and migration. MiR-26a-5p, miR-196a-5p, miR-196b-5p, miR-335-3p, and miR-1307-3p were found to be sponged by circRNA_101308 in CC cells. Further, GO and pathway analyses predicted the potential functional processes and pathways of circRNA_101308 in CC.

Conclusion

CircRNA_101308 is downregulated and acts as a tumor suppressor in CC. CircRNA_101308 can participate in many different processes by sponging different miRNAs in CC cells. This exploration of circRNA_101308 provides new directions for research on cancer development and the clinical treatment of CC.

Role of Exosomal miRNAs and the Tumor Microenvironment in Drug Resistance

Tumor microenvironment (TME) is composed of different cellular populations, such as stromal, immune, endothelial, and cancer stem cells. TME represents a key factor for tumor heterogeneity maintenance, tumor progression, and drug resistance. The transport of molecules via extracellular vesicles emerged as a key messenger in intercellular communication in the TME. Exosomes are small double-layered lipid extracellular vesicles that can carry a variety of molecules, including proteins, lipids, and nucleic acids. Exosomal miRNA released by cancer cells can mediate phenotypical changes in the cells of TME to promote tumor growth and therapy resistance, for example, fibroblast- and macrophages-induced differentiation. Cancer stem cells can transfer and enhance drug resistance in neighboring sensitive cancer cells by releasing exosomal miRNAs that target antiapoptotic and immune-suppressive pathways. Exosomes induce drug resistance by carrying ABC transporters, which export chemotherapeutic agents out of the recipient cells, thereby reducing the drug concentration to suboptimal levels. Exosome biogenesis inhibitors represent a promising adjunct therapeutic approach in cancer therapy to avoid the acquisition of a resistant phenotype. In conclusion, exosomal miRNAs play a crucial role in the TME to confer drug resistance and survivability to tumor cells, and we also highlight the need for further investigations in this promising field.

The Emerging Role of Exosomes in Diagnosis, Prognosis, and Therapy in Head and Neck Cancer

Exosomes, the smallest group of extracellular vesicles, carry proteins, miRNA, mRNA, DNA, and lipids, which they efficiently deliver to recipient cells, generating a communication network. Exosomes strongly contribute to the immune suppressive tumor microenvironment of head and neck squamous cell carcinomas (HNSCC). Isolation of exosomes from HNSCC cell culture or patient’s plasma allows for analyzing their molecular cargo and functional role in immune suppression and tumor progression. Immune affinity-based separation of different exosome subsets, such as tumor-derived or T cell-derived exosomes, from patient’s plasma simultaneously informs about tumor status and immune dysfunction. In this review, we discuss the recent understanding of how exosomes behave in the HNSCC tumor microenvironment and why they are promising liquid biomarkers for diagnosis, prognosis, and therapy in HNSCC.

Comprehensive landscape of extracellular vesicle-derived RNAs in cancer initiation, progression, metastasis and cancer immunology

Extracellular vesicles (EVs), a class of heterogeneous membrane vesicles, are generally divided into exosomes and microvesicles on basis of their origination from the endosomal membrane or the plasma membrane, respectively. EV-mediated bidirectional communication among various cell types supports cancer cell growth and metastasis. EVs derived from different cell types and status have been shown to have distinct RNA profiles, comprising messenger RNAs and non-coding RNAs (ncRNAs). Recently, ncRNAs have attracted great interests in the field of EV-RNA research, and growing numbers of ncRNAs ranging from microRNAs to long ncRNAs have been investigated to reveal their specific functions and underlying mechanisms in the tumor microenvironment and premetastatic niches. Emerging evidence has indicated that EV-RNAs are essential functional cargoes in modulating hallmarks of cancers and in reciprocal crosstalk within tumor cells and between tumor and stromal cells over short and long distance, thereby regulating the initiation, development and progression of cancers. In this review, we discuss current findings regarding EV biogenesis, release and interaction with target cells as well as EV-RNA sorting, and highlight biological roles and molecular mechanisms of EV-ncRNAs in cancer biology.

Tumor-Secreted Exosomal lncRNA POU3F3 Promotes Cisplatin Resistance in ESCC by Inducing Fibroblast Differentiation into CAFs

Cancer-associated fibroblasts (CAFs), an activated subpopulation of fibroblasts, occupy a central position in the tumor microenvironment and have been shown to promote chemoresistance in multiple cancer types by secreting inflammatory cytokines. Herein, we report that tumor-secreted exosomal long non-coding RNAs (lncRNAs) can regulate cisplatin resistance in esophageal squamous cell carcinoma (ESCC) through transformation of normal fibroblasts (NFs) to CAFs. Primary CAFs and matched NFs were isolated from tumor tissues and matched normal esophageal epithelial tissues of ESCC patients. Fluorescence microscopy and qRT-PCR were used to investigate the transportation of exosomal lncRNAs from ESCC cells to NFs. To identify the specific lncRNAs involved, 14 ESCC-related lncRNAs were measured in NFs after incubation with exosomes from ESCC cells. We demonstrated that lncRNA POU3F3 can be transferred from ESCC cells to NFs via exosomes and that it mediated fibroblast activation. Activated fibroblasts further promoted proliferation and cisplatin resistance of ESCC cells through secreting interleukin 6 (IL-6). Moreover, our clinical data showed that high levels of plasma exosomal lncRNA POU3F3 correlated significantly with lack of complete response and poor survival in ESCC patients. Therefore, these data demonstrate that lncRNA POU3F3 is involved in cisplatin resistance in ESCC and that this effect is mediated through exosomal lncRNA POU3F3-induced transformation of NFs to CAFs.

Extracellular vesicle encapsulated microRNA-320a inhibits endometrial cancer by suppression of the HIF1α/VEGFA axis

Accumulating evidence indicates that cancer-associated fibroblasts (CAFs) play a crucial role in endometrial cancer (EC) pathogenesis. The present study investigated the clinical significance and biological function of extracellular vesicle (EV) encapsulated miR-320a released from CAFs in EC. EC-related microarray data was obtained from the GSE25405 database and differential analysis was performed. Expression of miR-320a in CAFs and normal endometrial fibroblasts (NFs) as well as CAF-delivered EVs was detected; also, delivery of miR-320a from CAFs to EC cells was observed. In addition we confirmed that miR-320a targets HIF1α via a dual-luciferase reporter assay. Phenotypic analysis was used to study the functional significance of EV delivered miR-320a and its downstream effects. miR-320a was found to have low expression in EC cells and tissues. CAF-secreted EVs were successfully isolated and miR-320a was found also be expressed at low levels in these EVs. Finally, we found direct transfer of CAF-secreted exosomal miR-320a to EC cells, which inhibited their proliferation. Mechanistically, we found this is due to downregulation of HIF1α by miR-320a, which led to lowered VEGFA expression in vitro. Accordingly, we overexpressed HIF1α also showed that the inhibitory effect of miR-320a overexpression in EC cells could be reversed. These results point to CAF-derived EVs carrying overexpressed miR-320a as a novel direction for therapeutic strategies for EC.

Emerging Therapeutic RNAs for the Targeting of Cancer Associated Fibroblasts

Tumor mass consists of a complex ensemble of malignant cancer cells and a wide variety of resident and infiltrating cells, secreted factors, and extracellular matrix proteins that are referred as tumor microenvironment (TME). Cancer associated fibroblasts (CAFs) are key TME components that support tumor growth, generating a physical barrier against drugs and immune infiltration, and contributing to regulate malignant progression. Thus, it is largely accepted that therapeutic approaches aimed at hampering the interactions between tumor cells and CAFs can enhance the effectiveness of anti-cancer treatments. In this view, nucleic acid therapeutics have emerged as promising molecules. Here, we summarize recent knowledge about their role in the regulation of CAF transformation and tumor-promoting functions, highlighting their therapeutic utility and challenges.

Insight toward the MicroRNA Profiling of Laryngeal Cancers: Biological Role and Clinical Impact

Head and neck squamous cell carcinoma (HNSCC), a heterogeneous disease arising from various anatomical locations including the larynx, is a leading cause of death worldwide. Despite advances in multimodality treatment, the overall survival rate of the disease is still largely dismal. Early and accurate diagnosis of HNSCC is urgently demanded in order to prevent cancer progression and to improve the quality of the patient's life. Recently, microRNAs (miRNAs), a family of small non-coding RNAs, have been widely reported as new robust tools for prediction, diagnosis, prognosis, and therapeutic approaches of human diseases. Abnormally expressed miRNAs are strongly associated with cancer development, resistance to chemo-/radiotherapy, and metastatic potential through targeting a large variety of genes. In this review, we summarize on the recent reports that emphasize the pivotal biological roles of miRNAs in regulating carcinogenesis of HNSCC, particularly laryngeal cancer. In more detail, we report the characterized miRNAs with an evident either oncogenic or tumor suppressive role in the cancers. In addition, we also focus on the correlation between miRNA deregulation and clinical relevance in cancer patients. On the basis of intriguing findings, the study of miRNAs will provide a new great opportunity to access better clinical management of the malignancies.

MiR-210 in exosomes derived from CAFs promotes non-small cell lung cancer migration and invasion through PTEN/PI3K/AKT pathway

OBJECTIVE

Cancer-associated fibroblasts (CAFs) function as a crucial factor in tumor progression by carrying exosomes to neighboring cells. This study was assigned to expound the underlying mechanism of CAFs-derived exosomal miR-210 in non-small cell lung cancer (NSCLC) progression.

METHOD

CAFs and normal fibroblasts (NFs) were isolated and identified. Exosomes secreted from CAFs and NFs were isolated to analyze their effects on tumor volume and epithelial-mesenchymal transition (EMT). Exosomal miR-210 expression level was measured. The effects of exosomal miR-210 and UPF1 on cell viability, EMT, PTEN/PI3K/AKT signal pathway were determined. Dual-luciferase reporter gene assay was utilized to validate the binding of UPF1 to miR-210.

RESULTS

CAFs-derived exosomes (CAFs-exo) were successfully extracted and proven to be uptake by lung cancer cells. Up-regulated expression level of miR-210 was found in CAFs-exo, which was then proved to enhance cell migration, proliferation, invasion abilities and EMT in NSCLC cells. Overexpression of miR-210 can also inhibit UPF1 and PTEN, but activate the PTEN/PI3K/AKT pathway. UPF1 was a target gene of miR-210. MiR-210 can up-regulate UPF1 expression level to activate PTEN/PI3K/AKT pathway.

CONCLUSION

MiR-210 secreted by CAFs-exo could promote EMT by targeting UPF1 and activating PTEN/PI3K/AKT pathway, thereby promoting NSCLC migration and invasion.

Serum miR-222-3p as a Double-Edged Sword in Predicting Efficacy and Trastuzumab-Induced Cardiotoxicity for HER2-Positive Breast Cancer Patients Receiving Neoadjuvant Target Therapy

Background: We aimed to explore whether the expression of serum miR-222-3p might contribute to early prediction of therapeutic response, clinical outcomes, and adverse events for HER2-positive breast cancer patients receiving neoadjuvant therapy (NAT).

Methods: A total of 65 HER2-positive breast cancer patients receiving NAT were analyzed. The concentration of serum miR-222-3p was detected by quantitative real-time PCR. Logistic regression analysis was used to identify the association of serum miR-222-3p with pathological complete response (pCR). The relationship of serum miR-222-3p with disease-free survival (DFS) and overall survival (OS) was examined via log-rank test and Cox proportional hazards analysis. The ordered logistic regression was applied to evaluate the association between serum miR-222-3p and adverse events.

Results: The miR-222-3p low group was more likely to achieve pCR [odds ratio (OR) = 0.258, P = 0.043]. The interaction between miR-222-3p and presenting Ki67 level was also detected for pCR (OR = 49.230, P_interaction = 0.025). The miR-222-3p low group was correlated with superior DFS (P = 0.029) and OS (P = 0.0037). The expression of serum miR-222-3p was the independent protective factor for trastuzumab-induced cardiotoxicity (P < 0.05) and anemia (P = 0.013).

Conclusions: Serum miR-222-3p is the potential factor to predict pCR, survival benefit and trastuzumab-induced cardiotoxicity for HER2-positive breast cancer patients receiving NAT.

Non-coding RNAs in drug resistance of head and neck cancers: A review

Head and neck cancer (HNC), which includes epithelial malignancies of the upper aerodigestive tract (oral cavity, oropharynx, pharynx, hypopharynx, larynx, and thyroid), are slowly but consistently increasing, while the overall survival rate remains unsatisfactory. Because of the multifunctional anatomical intricacies of the head and neck, disease progression and therapy-related side effects often severely affect the patient's appearance and self-image, as well as their ability to breathe, speak, and swallow. Patients with HNC require a multidisciplinary approach involving surgery, radiation therapy, and chemotherapeutics. Chemotherapy is an important part of the comprehensive treatment of tumors, especially advanced HNC, but drug resistance is the main cause of poor clinical efficacy. The most important determinant of this phenomenon is still largely unknown. Recent studies have shown that non-coding RNAs have a crucial role in HNC drug resistance. In addition, they can serve as biomarkers in the diagnosis, treatment, and prognosis of HNCs. In this review, we summarize the relationship between non-coding RNAs and drug resistance of HNC, and discuss their potential clinical application in overcoming HNC chemoresistance.

Metabolic cell communication within tumour microenvironment: models, methods and perspectives

Environmental cues are essential in defining tumour malignancy, by promoting tumour initiation, progression and metastatic spreading. Stromal cells may metabolically cooperate or compete with cancer cells, playing a mandatory role in defining cancer metabolic plasticity, potentially dictating the final tumour outcome. Assessing shared nutrients between different tumoural or stromal compartments is essential to understand the impact of environmental nutrients on the metabolic plasticity of tumours. Here, we review analytical and computational approaches for studying the tumour metabolic microenvironment, the destiny of nutrients shared among tumour and stromal populations, as well as the molecular modules of these metabolic relationships.

The Role of Extracellular Vesicles in the Hallmarks of Cancer and Drug Resistance

Extracellular vesicles (EVs) mediate intercellular signaling and communication, allowing the intercellular exchange of proteins, lipids, and genetic material. Their recognized role in the maintenance of the physiological balance and homeostasis seems to be severely disturbed throughout the carcinogenesis process. Indeed, the modus operandi of cancer implies the highjack of the EV signaling network to support tumor progression in many (if not all) human tumor malignancies. We have reviewed the current evidence for the role of EVs in affecting cancer hallmark traits by: (i) promoting cell proliferation and escape from apoptosis, (ii) sustaining angiogenesis, (iii) contributing to cancer cell invasion and metastasis, (iv) reprogramming energy metabolism, (v) transferring mutations, and (vi) modulating the tumor microenvironment (TME) by evading immune response and promoting inflammation. Special emphasis was given to the role of EVs in the transfer of drug resistant traits and to the EV cargo responsible for this transfer, both between cancer cells or between the microenvironment and tumor cells. Finally, we reviewed evidence for the increased release of EVs by drug resistant cells. A timely and comprehensive understanding of how tumor EVs facilitate tumor initiation, progression, metastasis and drug resistance is instrumental for the development of innovative EV-based therapeutic approaches for cancer.

Exosomal long non-coding RNA MSTRG.292666.16 is associated with osimertinib (AZD9291) resistance in non-small cell lung cancer

Acquired resistance of osimertinib is encountered in clinic treatment of non-small cell lung cancer (NSCLC). However, the molecular mechanisms of osimertinib resistance are not fully revealed. This study aimed to investigate the roles of exosomes in delivering osimertinib resistance in NSCLC. Exosomes were successfully isolated. LncRNA sequencing identified a total of 123 differentially expressed lncRNAs, including 45 upregulated lncRNAs and 78 downregulated lncRNAs. The relative expression level of lncRNA MSTRG.292666.16 was significantly upregulated in osimertinib-resistant plasma, osimertinib-resistant H1975R cells and their derived exosomes, compared with those in osimertinib- sensitive plasma, H1975 cells and exosomes (P < 0.05). Besides, osimertinib-resistant exosomes could regulate gene expressions induced by osimertinib, including miRNA-21, miRNA-125b, TGFβ, ARF6 and c-Kit. Osimertinib-resistant exosomes could be taken up by osimertinib-sensitive H1975 cells and resulting in osimertinib-resistance in vivo. Knockdown of lncRNA MSTRG.292666.16 decreased osimertinib resistance of H1975R cells. Our results suggest that exosomal lncRNA MSTRG.292666.16 might be associated with osimertinib resistance in NSCLC.

Exosomal microRNAs-mediated intercellular communication and exosome-based cancer treatment

Exosomes are extracellular vesicles with a diameter of about 30 to 100 nm, which play a crucial role in intercellular communication. Compared with normal cells, the release rate of tumor-derived exosomes (TDEs) significantly increased, and exosomal contents, especially microRNAs (miRNAs), greatly changed. TDEs contribute to the proliferation, metastasis and resistance of tumor cells, regulate immune response and tumor autophagy, and mediate tumor-stroma communication. In addition, exosomes may be involved in tumor complications. In view of the role of exosomes in intercellular communication, exosomes have been developed as tumor biomarkers, therapeutic targets, and drug delivery systems for tumor diagnosis, prognosis and treatment. Despite the many advantages of exosomes, there are many challenges in exosomal development and application, such as incomprehensive understanding of biological functions, safety and specificity for therapeutic use. This article reviews the biogenesis of TDEs and focuses on the role of exosomal miRNAs in intercellular communication and exosome-based treatment for cancer.

Exosomal miRNAs in tumor microenvironment

Tumor microenvironment (TME) is the internal environment in which tumor cells survive, consisting of tumor cells, fibroblasts, endothelial cells, and immune cells, as well as non-cellular components, such as exosomes and cytokines. Exosomes are tiny extracellular vesicles (40-160nm) containing active substances, such as proteins, lipids and nucleic acids. Exosomes carry biologically active miRNAs to shuttle between tumor cells and TME, thereby affecting tumor development. Tumor-derived exosomal miRNAs induce matrix reprogramming in TME, creating a microenvironment that is conducive to tumor growth, metastasis, immune escape and chemotherapy resistance. In this review, we updated the role of exosomal miRNAs in the process of TME reshaping.

The Role of Exosomal microRNA in Cancer Drug Resistance

Exosomes affect the initiation and progression of cancers. In the tumor microenvironment, not only cancer cells, but also fibroblasts and immunocytes secrete exosomes. Exosomes act as a communicator between cells by transferring different cargos and microRNAs (miRNAs). Drug resistance is one of the critical factors affecting therapeutic effect in the course of cancer treatment. The currently known mechanisms of drug resistance include drug efflux, alterations in drug metabolism, DNA damage repair, alterations of energy programming, cancer stem cells and epigenetic changes. Many studies have shown that miRNA carried by exosomes is closely associated with the development of drug resistance mediated by the above-mentioned mechanisms. This review article will discuss how exosomal miRNAs regulate the drug resistance.

The Drug-Resistance Mechanisms of Five Platinum-Based Antitumor Agents

Platinum-based anticancer drugs, including cisplatin, carboplatin, oxaliplatin, nedaplatin, and lobaplatin, are heavily applied in chemotherapy regimens. However, the intrinsic or acquired resistance severely limit the clinical application of platinum-based treatment. The underlying mechanisms are incredibly complicated. Multiple transporters participate in the active transport of platinum-based antitumor agents, and the altered expression level, localization, or activity may severely decrease the cellular platinum accumulation. Detoxification components, which are commonly increasing in resistant tumor cells, can efficiently bind to platinum agents and prevent the formation of platinum–DNA adducts, but the adducts production is the determinant step for the cytotoxicity of platinum-based antitumor agents. Even if adequate adducts have formed, tumor cells still manage to survive through increased DNA repair processes or elevated apoptosis threshold. In addition, autophagy has a profound influence on platinum resistance. This review summarizes the critical participators of platinum resistance mechanisms mentioned above and highlights the most potential therapeutic targets or predicted markers. With a deeper understanding of the underlying resistance mechanisms, new solutions would be produced to extend the clinical application of platinum-based antitumor agents largely.

Exosomal circular RNA sorting mechanisms and their function in promoting or inhibiting cancer

Exosomes are nanoscale phospholipid bilayer vesicles that can be artificially engineered into vectors for the treatment of cancer. Circular RNA (circRNA), a type of non-coding RNA, has crucial regulatory functions in various aspects of cancer, such as tumorigenesis, apoptosis, proliferation, invasion, metastasis and chemo- and radiotherapeutic resistance, as well as in cancer prognosis. Notably, the exosomal transfer of circRNAs may function to both promote and inhibit cancer. Numerous studies have addressed the importance of circRNAs in cancer and non-coding RNAs (such as microRNAs and long non-coding RNAs) in exosomes. However, little research has focussed on a class of RNAs called exosomal circRNAs. The present review discusses current studies regarding exosomal circRNAs, including their biogenesis and biological functions, their abundance in exosomes and possible sorting mechanisms and their potential roles in both promoting and inhibiting cancer. It is predicted that in the next five years there will be increasing research exploring the functional mechanisms of exosomal circRNA in various diseases, in particular their roles in cancer genesis and progression.

A Novel Model of Cancer Drug Resistance: Oncosomal Release of Cytotoxic and Antibody-Based Drugs

Extracellular vesicles (EVs), such as exosomes or oncosomes, often carry oncogenic molecules derived from tumor cells. In addition, accumulating evidence indicates that tumor cells can eject anti-cancer drugs such as chemotherapeutics and targeted drugs within EVs, a novel mechanism of drug resistance. The EV-releasing drug resistance phenotype is often coupled with cellular dedifferentiation and transformation in cells undergoing epithelial-mesenchymal transition (EMT), and the adoption of a cancer stem cell phenotype. The release of EVs is also involved in immunosuppression. Herein, we address different aspects by which EVs modulate the tumor microenvironment to become resistant to anticancer and antibody-based drugs, as well as the concept of the resistance-associated secretory phenotype (RASP).

Long noncoding RNA KTN1-AS1 promotes head and neck squamous cell carcinoma cell epithelial-mesenchymal transition by targeting miR-153-3p

Aim: To explore the biological functions and clinicopathologic significance of the long noncoding RNA KTN1-AS1 in head and neck squamous cell carcinoma (HNSCC). Materials & methods: We assessed the effects of KTN1-AS1 and identified the target miRNA by bioinformatics analysis, luciferase reporter, RNA pull-down and RNA immunoprecipitation assays. The clinicopathologic features of KTN1-AS1 and its target miRNA were analyzed in HNSCC. Results:KTN1-AS1, a competing endogenous RNA, promoted cell proliferation, migration, invasion and epithelial-mesenchymal transition by sponging miR-153-3p in HNSCC. Dysregulation of SNAI1 and ZEB2 mediated the effect of KTN1-AS1 due to miR-153-3p exhaustion. The KTN1-AS1 and miR-153-3p combination can accurately diagnose HNSCC. Conclusion: The KTN1-AS1 and miR-153-3p combination could be a valuable diagnostic and prognostic predictor for HNSCC.