Cancer‑associated fibroblast‑derived exosomal miR‑382‑5p promotes the migration and invasion of oral squamous cell carcinoma

Cancer-Associated Fibroblasts Boost Tumorigenesis of Clear Cell Renal Cell Carcinoma via Exosome-Mediated Paracrine SNHG1

Despite the dominant roles of cancer-associated fibroblasts (CAFs) have attached much attention in tumorigenesis, the CAFs-derived molecular determinants that regulate renal cell carcinoma (RCC) development remains elusive. Our previous study uncovered an oncogenic SNHG1 in the immune escape of RCC, whereas CAFs-derived exosomes could be a source accounting for increasing SNHG1 in RCC cells, this is still a mystery. The obtained CAFs and normal fibroblast (NFs) from fresh RCC and adjacent tissues were firstly identified using western blot and immunofluorescent staining. The enrichment of SNHG1 was validated by RT-qPCR. CAFs-derived exosomes were isolated from conditioned medium using ultracentrifugation method and ExoQuick-TC system. The internalization of exosomes, transfer of SNHG1, was measured by immunofluorescence. Regulation of conditioned medium or exosomal SNHG1 from CAFs on RCC biological functions was evaluated by CCK-8, EdU incorporation, colony formation, and transwell assays to assess the RCC cell proliferation, migration, and invasion. SNHG1 was significantly upregulated in CAFs isolated from RCC stroma. Exosomes derived from CAFs transferred SNHG1 to RCC cells and resulted in an increased SNHG1 expression in RCC cells. The exosomes excreted by CAFs promoted RCC cell proliferation, migration, and invasion, whereas the promotion effect of CAFs-exosomes on RCC progression was attenuated by SNHG1 knockdown. The present study revealed a new mechanism of exosomal SNHG1 extracted from CAFs enhanced RCC progression and may provide a potential target for the treatment of RCC.

Extracellular vesicles promote migration despite BRAF inhibitor treatment in malignant melanoma cells

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.

The hidden messengers: cancer associated fibroblasts-derived exosomal miRNAs as key regulators of cancer malignancy

Cancer-associated fibroblasts (CAFs), a class of stromal cells in the tumor microenvironment (TME), play a key role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis, and resistance to chemotherapy. CAFs mediate their activities by secreting soluble chemicals, releasing exosomes, and altering the extracellular matrix (ECM). Exosomes contain various biomolecules, such as nucleic acids, lipids, and proteins. microRNA (miRNA), a 22-26 nucleotide non-coding RNA, can regulate the cellular transcription processes. Studies have shown that miRNA-loaded exosomes secreted by CAFs engage in various regulatory communication networks with other TME constituents. This study focused on the roles of CAF-derived exosomal miRNAs in generating cancer malignant characteristics, including immune modulation, tumor growth, migration and invasion, epithelial-mesenchymal transition (EMT), and treatment resistance. This study thoroughly examines miRNA's dual regulatory roles in promoting and suppressing cancer. Thus, changes in the CAF-derived exosomal miRNAs can be used as biomarkers for the diagnosis and prognosis of patients, and their specificity can be used to develop newer therapies. This review also discusses the pressing problems that require immediate attention, aiming to inspire researchers to explore more novel avenues in this field.

Role of exosomes in the communication and treatment between OSCC and normal cells

Oral squamous cell carcinoma (OSCC) is a prevalent cancer that needs new therapeutic targets due to the poor postoperative prognosis in patients. Exosomes are currently one of important research areas owing to their unique properties. Exosomes are capable of acting as drug transporters, as well as facilitating interactions between OSCC and normal cells. Exosomes can be detected in body fluids such as blood, urine, cerebrospinal fluid, and bile. When exosomes are released from donor cells, they can carry various bioactive molecules to recipient cells, where these molecules participate in biological processes. This review highlights the mechanisms of exosome transfer between normal and OSCC cells. Exosomes isolated from donor OSCC cells can carry circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and microRNAs (miRNAs) and play a role in signaling processes in the recipient OSCC cells, human umbilical vein endothelial cells, and macrophages. Exosomes secreted by carcinoma-associated fibroblasts, macrophages, and stem cells can also enter the recipient OSCC cells and modulate signaling events in these cells. Exosomes isolated from OSCC plasma, serum, and saliva are also associated with OSCC prognosis. Furthermore, while exosomes were shown to be associated with chemotherapy resistance in OSCC, they can also be used for drug delivery during OSCC treatment. In this paper, we reviewed the molecular mechanisms and functions of exosomes from different cell sources in OSCC cells, providing a basis for diagnosis and prognosis prediction in OSCC patients, and offering guidance for the design of molecular targets carried by exosomes in OSCC.

Cancer-associated fibroblasts: a versatile mediator in tumor progression, metastasis, and targeted therapy

Tumor microenvironment (TME) has been demonstrated to play a significant role in tumor initiation, progression, and metastasis. Cancer-associated fibroblasts (CAFs) are the major component of TME and exhibit heterogeneous properties in their communication with tumor cells. This heterogeneity of CAFs can be attributed to various origins, including quiescent fibroblasts, mesenchymal stem cells (MSCs), adipocytes, pericytes, endothelial cells, and mesothelial cells. Moreover, single-cell RNA sequencing has identified diverse phenotypes of CAFs, with myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs) being the most acknowledged, alongside newly discovered subtypes like antigen-presenting CAFs (apCAFs). Due to these heterogeneities, CAFs exert multiple functions in tumorigenesis, cancer stemness, angiogenesis, immunosuppression, metabolism, and metastasis. As a result, targeted therapies aimed at the TME, particularly focusing on CAFs, are rapidly developing, fueling the promising future of advanced tumor-targeted therapy.

Dynamic interactions in the tumor niche: how the cross-talk between CAFs and the tumor microenvironment impacts resistance to therapy

The tumor microenvironment (TME) is a complex ecosystem of cells, signaling molecules, and extracellular matrix components that profoundly influence cancer progression. Among the key players in the TME, cancer-associated fibroblasts (CAFs) have gained increasing attention for their diverse and influential roles. CAFs are activated fibroblasts found abundantly within the TME of various cancer types. CAFs contribute significantly to tumor progression by promoting angiogenesis, remodeling the extracellular matrix, and modulating immune cell infiltration. In order to influence the microenvironment, CAFs engage in cross-talk with immune cells, cancer cells, and other stromal components through paracrine signaling and direct cell-cell interactions. This cross-talk can result in immunosuppression, tumor cell proliferation, and epithelial-mesenchymal transition, contributing to disease progression. Emerging evidence suggests that CAFs play a crucial role in therapy resistance, including resistance to chemotherapy and radiotherapy. CAFs can modulate the tumor response to treatment by secreting factors that promote drug efflux, enhance DNA repair mechanisms, and suppress apoptosis pathways. This paper aims to understand the multifaceted functions of CAFs within the TME, discusses cross-talk between CAFs with other TME cells, and sheds light on the contibution of CAFs to therapy resistance. Targeting CAFs or disrupting their cross-talk with other cells holds promise for overcoming drug resistance and improving the treatment efficacy of various cancer types.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Cancer-associated fibroblast-derived extracellular vesicles promote lymph node metastases in oral cavity squamous cell carcinoma by encapsulating ITGB1 and BMI1

BACKGROUND

Extracellular vesicles (EVs) have been revealed to facilitate the development of oral squamous cavity cell carcinoma (OCSCC), while its supporting role in lymph node metastases is under continuous investigation. This study aimed to examine the function of cancer-associated fibroblasts (CAF)-derived EVs (CAF-EVs) during lymph node metastasis in OCSCC and the mechanisms.

METHODS

CAF were isolated from OCSCC tissues of patients, and CAF-EVs were extracted and identified. EdU, colony formation, wound healing, and Transwell assays were performed. The OCSCC cells before and after CAF-EVs treatment were injected into mice to probe the effects of CAF-EVs on tumor growth and lymph node metastasis, respectively. The effect of CAF-EVs treatment on transcriptome changes in OCSCC cells was analyzed. Clinical data of patients with OCSCC were analyzed to determine the prognostic significance of the selected genes. Finally, loss-of-function assays were conducted to corroborate the involvement of polycomb complex protein BMI-1 (BMI1) and integrin beta1 (ITGB1).

RESULTS

CAF-EVs promoted the malignant behavior of OCSCC cells and accelerated tumor growth and lymph node metastasis in mice. CAF-EVs significantly increased the expression of BMI1 and ITGB1, and the expression of BMI1 and ITGB1 was negatively correlated with the overall survival and relapse-free survival of OCSCC patients. Knockdown of BMI1 or ITGB1 in OCSCC cells abated the promoting effects of CAF-EVs in vitro and in vivo.

CONCLUSION

CAF-EVs elicited the metastasis-promoting properties in OCSCC by elevating BMI1 and ITGB1, suggesting that BMI1 and ITGB1 could be potential biomarkers and therapeutic targets for OCSCC.

Emerging roles of exosomes in oral diseases progression

Oral diseases, such as periodontitis, salivary gland diseases, and oral cancers, significantly challenge health conditions due to their detrimental effects on patient's digestive functions, pronunciation, and esthetic demands. Delayed diagnosis and non-targeted treatment profoundly influence patients' prognosis and quality of life. The exploration of innovative approaches for early detection and precise treatment represents a promising frontier in oral medicine. Exosomes, which are characterized as nanometer-sized extracellular vesicles, are secreted by virtually all types of cells. As the research continues, the complex roles of these intracellular-derived extracellular vesicles in biological processes have gradually unfolded. Exosomes have attracted attention as valuable diagnostic and therapeutic tools for their ability to transfer abundant biological cargos and their intricate involvement in multiple cellular functions. In this review, we provide an overview of the recent applications of exosomes within the field of oral diseases, focusing on inflammation-related bone diseases and oral squamous cell carcinomas. We characterize the exosome alterations and demonstrate their potential applications as biomarkers for early diagnosis, highlighting their roles as indicators in multiple oral diseases. We also summarize the promising applications of exosomes in targeted therapy and proposed future directions for the use of exosomes in clinical treatment.

Unraveling the role of miRNAs in the diagnosis, progression, and drug resistance of oral cancer

Oral cancer (OC) is a widely observed neoplasm on a global scale. Over time, there has been an increase in both its fatality and incidence rates. Oral cancer metastasis is a complex process that involves a number of cellular mechanisms, including invasion, migration, proliferation, and escaping from malignant tissue through either lymphatic or vascular channels. MicroRNAs (miRNAs) are a crucial class of short non-coding RNAs recognized as significant modulators of diverse cellular processes and exert a pivotal influence on the carcinogenesis pathway, functioning either as tumor suppressors or as oncogenes. It has been shown that microRNAs (miRNAs) have a role in metastasis at several stages, including epithelial-mesenchymal transition, migration, invasion, and colonization. This regulation is achieved by targeting key genes involved in these pathways by miRNAs. This paper aims to give a contemporary analysis of OC, focusing on its molecular genetics. The current literature and emerging advancements in miRNA dysregulation in OC are thoroughly examined. This project would advance OC diagnosis, prognosis, therapy, and therapeutic implications.

Exosomes: Mediators of cellular communication in potentially malignant oral lesions and head and neck cancers

Exosomes are a unique type of extracellular vesicles that contain a plethora of biological cargo such as miRNA, mRNA, long non-coding RNA, DNA, proteins and lipids. Exosomes serve as very effective means of intercellular communication. Due the presence of a lipid bilayer membrane, exosomes are resistant to degradation and are highly stable. This makes them easily identifiable in blood and other bodily fluids such as saliva. The exosomes that are secreted from a parent cell directly release their contents into the cytoplasm of a recipient cell and influence their cellular activity and function. Exosomes can also transfer their content between cancer cells and normal cells and regulate the tumor microenvironment. Exosomes play a vital role in tumor growth, tumor invasion and metastasis. Exosomes provide a multitude of molecular and genetic information and have become valuable indicators of disease activity at the cellular level. This review explores the molecular characteristics of exosomes and the role that exosomes play in the tumorigenesis pathway of potentially malignant oral lesions and head and neck cancers The application of exosomes in the treatment of oral cancers is also envisioned. Exosomes are very small and can easily pass through various biological barriers, making them very good delivery vectors for therapeutic drugs as well as to selectively induce DNA's mRNA and miRNAs into targeted cancer cells.

MiR-3529-3p from PDGF-BB-induced cancer-associated fibroblast-derived exosomes promotes the malignancy of oral squamous cell carcinoma

AIMS

This study aims to explore the role of exosomes from cancer-associated fibroblasts (CAFs) induced by PDGF-BB in promoting the malignancy of oral squamous cell carcinoma (OSCC) and provide new insight into the mechanism of OSCC progression and its treatment.

MAIN METHODS

Exosomes were extracted from human oral mucosa fibroblasts (hOMFs) and CAFs. Differentially expressed miRNAs of exosomes between hOMFs and CAFs were analysed using high-throughput sequencing and self-programmed R software. Cal-27, a human tongue squamous carcinoma cell line, was treated with exosomes. Differentially expressed miRNAs between clinical cancer tissues and adjacent tissues and between hOMF and CAF exosomes were verified by qRT‒PCR. The effect of miR-3529-3p on Cal-27 cells was clarified by overexpressing or knocking down miR-3529-3p in Cal-27 cells. Sample expression and differentially expressed miRNA expression were compared between cancer and paracarcinoma tissues.

KEY FINDINGS

We found that exosomes from CAFs (CAF-Exos) were internalized by tongue squamous carcinoma cells and promoted their proliferation, migration, invasion, and antiapoptotic effects. MiR-3529-3p was a significant differentially expressed miRNA between CAF-Exos and exosomes from hOMFs (hOMF-Exos). The overexpression of miR-3529-3p promoted proliferation, migration, and invasion and inhibited apoptosis of Cal-27 cells.

SIGNIFICANCE

This study explores the role of PDGF-BB-induced CAFs in promoting malignancy in OSCC. This study will provide new insight into the mechanism of OSCC progression and its treatment.

Protective effects of hsa_circ_0072568 on interleukin‑1β‑stimulated human chondrocytes are mediated via the miR‑382‑5p/TOP1 axis

Circular RNA (circRNA) dysregulation has been linked to osteoarthritis (OA). The present study investigated the involvement of hsa_circ_0072568 (circ0072568) in OA. The expression of circ0072568 was detected in OA tissues and interleukin (IL)-1β-stimulated human chondrocytes. After performing dual-luciferase reporter and RNA immunoprecipitation assays, MTT, enzyme-linked immunosorbent assay and western blot analysis were used to assess the functions of circ0072568 in IL-1β-induced inflammation in chondrocytes in vitro. Circ0072568 was inhibited in OA tissues and the cell model in vitro. Circ0072568 overexpression protected the chondrocytes against IL-1β-induced inflammation and extracellular matrix (ECM) breakdown. Circ0072568 directly attached to microRNA (miR)-382-5p and enhanced the production of topoisomerase 1 (TOP1). Furthermore, miR-382-5p overexpression or TOP1 knockdown attenuated the effects of circ0072568 in IL-1β-stimulated human chondrocytes. On the whole, the present study demonstrates that the Circ0072568/miR-382-5p/TOP1 axis is involved in inflammation and ECM degradation in OA. These findings may contribute to the development of potential therapeutic strategies for OA.

Analysis of mRNA-miRNA interaction network reveals the role of CAFs-derived exosomes in the immune regulation of oral squamous cell carcinoma

BACKGROUND

Cancer-associated fibroblasts (CAFs) have significant tumor regulatory functions, and CAFs-derived exosomes (CAFs-Exo) released from CAFs play an important role in the progression of oral squamous cell carcinoma (OSCC). However, a lack of comprehensive molecular biological analysis leaves the regulatory mechanisms of CAFs-Exo in OSCC unclear.

METHODS

We used platelet derived growth factor-BB (PDGF-BB) to induce the transformation of human oral mucosa fibroblast (hOMF) into CAFs, and extracted exosomes from the supernatant of CAFs and hOMF. We validated the effect of CAFs-Exo on tumor progression by exosomes co-culture with Cal-27 and tumor-forming in nude mice. The cellular and exosomal transcriptomes were sequenced, and immune regulatory genes were screened and validated using mRNA-miRNA interaction network analysis in combination with publicly available databases.

RESULTS

The results showed that CAFs-Exo had a stronger ability to promote OSCC proliferation and was associated with immunosuppression. We discovered that the presence of immune-related genes in CAFs-Exo may regulate the expression of PIGR, CD81, UACA, and PTTG1IP in Cal-27 by analyzing CAFs-Exo sequencing data and publicly available TCGA data. This may account for the ability of CAFs-Exo to exert immunomodulation and promote OSCC proliferation.

CONCLUSIONS

CAFs-Exo was found to be involved in tumor immune regulation through hsa-miR-139-5p, ACTR2 and EIF6, while PIGR, CD81, UACA and PTTG1IP may be potentially effective targets for the treatment of OSCC in the future.

Targeting oral tumor microenvironment for effective therapy

Oral cancers are among the common head and neck malignancies. Different anticancer therapy modalities such as chemotherapy, immunotherapy, radiation therapy, and also targeted molecular therapy may be prescribed for targeting oral malignancies. Traditionally, it has been assumed that targeting malignant cells alone by anticancer modalities such as chemotherapy and radiotherapy suppresses tumor growth. In the last decade, a large number of experiments have confirmed the pivotal role of other cells and secreted molecules in the tumor microenvironment (TME) on tumor progression. Extracellular matrix and immunosuppressive cells such as tumor-associated macrophages, myeloid-derived suppressor cells (MDSCs), cancer-associated fibroblasts (CAFs), and regulatory T cells (Tregs) play key roles in the progression of tumors like oral cancers and resistance to therapy. On the other hand, infiltrated CD4 + and CD8 + T lymphocytes, and natural killer (NK) cells are key anti-tumor cells that suppress the proliferation of malignant cells. Modulation of extracellular matrix and immunosuppressive cells, and also stimulation of anticancer immunity have been suggested to treat oral malignancies more effectively. Furthermore, the administration of some adjuvants or combination therapy modalities may suppress oral malignancies more effectively. In this review, we discuss various interactions between oral cancer cells and TME. Furthermore, we also review the basic mechanisms within oral TME that may cause resistance to therapy. Potential targets and approaches for overcoming the resistance of oral cancers to various anticancer modalities will also be reviewed. The findings for targeting cells and potential therapeutic targets in clinical studies will also be reviewed.

[Oral Squamous Cell Carcinoma-Derived Cell-Free DNA Modulates Stemness and Migration of Oral Squamous Cell Carcinoma Cell Line by Inducing M2 Macrophage Polarization]

Objective

To investigate the effect of oral squamous cell carcinoma (OSCC)-derived cell-free DNA (cfDNA) on the polarization of macrophages and the regulatory effect of polarized macrophages on the stemness and migration of OSCC cells.

Methods

A total of 30 OSCC tissue samples, 10 dysplastic oral tissue samples, and 10 normal oral tissue samples were collected. The status of all tissue samples was confirmed by pathology analysis. Immunohistochemical (IHC) staining and immunofluorescence (IF) staining were performed to examine the cell count and location of M2 macrophages in different types of oral tissue samples. The conditioned medium (CM) of OSCC cell line CAL-27 from the human tongue was collected and the cfDNA was concentrated and isolated for identification. The macrophages were treated by cfDNA and their morphological characteristics were observed under microscope. The expression levels of polarization-related indicators were determined by RT-qPCR. CAL-27 cell line was treated with macrophage CM induced by cfDNA and the expression levels of stemness-related genes were determined by RT-qPCR. Scratch-wound assay was conducted to verify that the migration ability of CAL-27 was modulated by macrophages induced by cfDNA.

Results

There were more M2 macrophages in the deep connective tissue of dysplastic oral epithelium and the stroma of OSCC compared with those in the normal oral tissues ( P<0.05). OSCC cell line CAL-27 could secret cfDNA of 10000-15000 bp in length. cfDNA secreted by CAL-27 could induced in macrophages significantly higher expression of M2-macrophage-related genes ( P<0.05). cfDNA-treated macrophages induced significantly increased expression of stemness-related genes in CAL-27 cell line ( P<0.05) and promoted the migration ability of CAL-27 cell line ( P<0.05).

Conclusion

OSCC-derived cfDNA promotes stemness and migration of OSCC cell line by inducing M2 macrophage polarization.

The tumor ecosystem in head and neck squamous cell carcinoma and advances in ecotherapy

The development of head and neck squamous cell carcinoma (HNSCC) is a multi-step process, and its survival depends on a complex tumor ecosystem, which not only promotes tumor growth but also helps to protect tumor cells from immune surveillance. With the advances of existing technologies and emerging models for ecosystem research, the evidence for cell-cell interplay is increasing. Herein, we discuss the recent advances in understanding the interaction between tumor cells, the major components of the HNSCC tumor ecosystem, and summarize the mechanisms of how biological and abiotic factors affect the tumor ecosystem. In addition, we review the emerging ecological treatment strategy for HNSCC based on existing studies.

Bone marrow mesenchymal stem cell-derived exosomal microRNA-382 promotes osteogenesis in osteoblast via regulation of SLIT2

BACKGROUND

Osteoporosis (OP) is a systemic skeletal disorder with increased bone fragility. Human bone marrow mesenchymal stem cells (hBMSCs) have multi-lineage differentiation ability, which may play important roles in osteoporosis. In this study, we aim to investigate the role of hBMSC-derived miR-382 in osteogenic differentiation.

METHODS

The miRNA and mRNA expressions in peripheral blood monocytes between persons with high or low bone mineral density (BMD) were compared. Then we collected the hBMSC-secreted sEV and examined the dominant components. The over-expression of the miR-382 in MG63 cell and its progression of osteogenic differentiation were investigated by qRT-PCR, western blot and alizarin red staining. The interaction between miR-382 and SLIT2 was confirmed by dual-luciferase assay. The role of SLIT2 was also confirmed through up-regulation in MG63 cell, and the osteogenic differentiation-associated gene and protein were tested.

RESULTS

According to bioinformatic analysis, a series of differential expressed genes between persons with high or low BMD were compared. After internalization of hBMSC-sEV in MG63 cells, we observed that the ability of osteogenic differentiation was significantly enhanced. Similarly, after up-regulation of miR-382 in MG63 cells, osteogenic differentiation was also promoted. According to the dual-luciferase assay, the targeting function of miR-382 in SLIT2 was demonstrated. Moreover, the benefits of hBMSC-sEV in osteogenesis were abrogated through up-regulation of SLIT2.

CONCLUSION

Our study provided evidence that miR-382-contained hBMSC-sEV held great promise in osteogenic differentiation in MG63 cells after internalization by targeting SLIT2, which can be served as molecular targets to develop effective therapy.

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

Intercellular crosstalk between cancer cells and cancer-associated fibroblasts via extracellular vesicles

Intercellular communication plays an important role in cancer initiation and progression through direct contact and indirect interactions, such as via secretory molecules. Cancer-associated fibroblasts (CAFs) are one of the principal components of such communication with cancer cells, modulating cancer metastasis and tumour mechanics and influencing angiogenesis, the immune system, and therapeutic resistance. Over the past few years, there has been a significant increase in research on extracellular vesicles (EVs) as regulatory agents in intercellular communication. EVs enable the transfer of functional molecules, including proteins, mRNAs and microRNAs (miRNAs), to recipient cells. Cancer cells utilize EVs to dictate the specific characteristics of CAFs within the tumour microenvironment, thereby promoting cancer progression. In response to such "education" by cancer cells, CAFs contribute to cancer progression via EVs. In this review, we summarize experimental data indicating the pivotal roles of EVs in intercellular communication between cancer cells and CAFs.

Regulation of epigenetic modifications in the head and neck tumour microenvironment

Head and neck tumours are common malignancies that are associated with high mortality. The low rate of early diagnosis and the high rates of local recurrence and distant metastasis are the main reasons for treatment failure. Recent studies have established that the tumour microenvironment (TME) can affect the proliferation and metastasis of head and neck tumours via several mechanisms, including altered expressions of certain genes and cytokines. Increasing evidence has shown that epigenetic modifications, such as DNA methylation, histone modification, RNA modification, and non-coding RNAs, can regulate the head and neck TME and thereby influence tumour development. Epigenetic modifications can regulate the expression of different genes and subsequently alter the TME to affect the progression of head and neck tumours. In addition, the cell components in the TME are regulated by epigenetic modifications, which, in turn, affect the behaviour of head and neck tumour cells. In this review, we have discussed the functions of epigenetic modifications in the head and neck TME. We have further examined the roles of such modifications in the malignancy and metastasis of head and neck tumours.

Current status and perspective of tumor immunotherapy for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) have a high incidence and mortality rate, and investigating the pathogenesis and potential therapeutic strategies of HNSCC is required for further progress. Immunotherapy is a considerable therapeutic strategy for HNSCC due to its potential to produce a broad and long-lasting antitumor response. However, immune escape, which involves mechanisms including dyregulation of cytokines, perturbation of immune checkpoints, and recruitment of inhibitory cell populations, limit the efficacy of immunotherapy. Currently, multiple immunotherapy strategies for HNSCC have been exploited, including immune checkpoint inhibitors, costimulatory agonists, antigenic vaccines, oncolytic virus therapy, adoptive T cell transfer (ACT), and epidermal growth factor receptor (EGFR)-targeted therapy. Each of these strategies has unique advantages, and the appropriate application of these immunotherapies in HNSCC treatment has significant value for patients. Therefore, this review comprehensively summarizes the mechanisms of immune escape and the characteristics of different immunotherapy strategies in HNSCC to provide a foundation and consideration for the clinical treatment of HNSCC.

Cancer associated fibroblasts secreted exosomal miR-1290 contributes to prostate cancer cell growth and metastasis via targeting GSK3β

Cancer-associated fibroblasts (CAFs) play crucial roles in mediating tumor growth and metastasis via transferring exosomes to neighboring cells, whereas the mechanisms by which CAFs regulate the tumorgenesis of prostate cancer (PC) remain largely unknown. In this study, CAFs and normal fibroblasts (NFs) were isolated from PC tissues and adjacent normal tissues, respectively. Exosomes (NFs-Exo and CAFs-Exo) were then isolated from the supernatant of NFs and CAFs. Next, the differentially expressed miRNAs (DEMs) between NFs-Exo and CAFs-Exo were identified using RNA-sequencing. Cell viability, migration and invasion were detected with CCK-8 and Transwell assays. Protein expression was measured with western blot. We found that CAFs-Exo remarkably enhanced PC cell migration, invasion, stemness, epithelial-mesenchymal transition (EMT) and metastasis. Significantly, miR-1290 level was upregulated in CAFs-Exo compared to NFs-Exo. In addition, CAFs could transfer exosomes to PC cells, resulting in a marked increase of miR-1290 level in cells. Moreover, exosomal miR-1290 could inhibit GSK3β/β-catenin signaling by binding with the downstream target GSK3β mRNA. Meanwhile, miR-1290 antagomir notably reversed the effects of CAFs-Exo on PC cells through activating GSK3β/β-catenin signaling. Collectively, exosomal miR-1290 from CAFs could promote PC cell growth and metastasis via inhibiting GSK3β/β-catenin signaling, suggesting that miR-1290 may serve as potential therapeutic target for the treatment of PC.

MiR-222 regulates the progression of oral squamous cell carcinoma by targeting CDKN1B

OBJECTIVE

The purpose of this study was to establish a causal relationship between microRNA (miR-222) and oral squamous cell carcinoma (OSCC).

METHODS

The cell viability of each treatment group was measured by MTT. The effects of miR-222 on cell metastasis and apoptosis were measured by transwell and flow cytometry. The targeting relationship between miR-222 and CDKN1B was verified by dual-luciferase reporter gene assay and Western blot. Cell derived xenograft was further constructed to verify the effect of miR-222 on tumor growth by observing tumor weight and volume. The proliferation of tumor tissue was determined by hematoxylin-eosin staining and immunohistochemical staining.

RESULTS

Compared with those in adjacent tissues and normal cells, the levels of miR-222 in OSCC tissues and cells were significantly increased (P<0.05). The miR-222 mimic group promoted tumor cell proliferation, migration and cell cycle and inhibited cell apoptosis significantly (P<0.05). The up-regulation of CDKN1B expression inhibited cell viability, migration and invasiveness and promoted the apoptosis of OSCC (P<0.05). The dual-luciferase reporter gene assay found that miR-222 was targeted to CDKN1B and could inhibit fluorescence activity (P<0.05). In vivo assays showed that miR-222 could promote tumor growth through CDKN1B (P<0.05).

CONCLUSION

MiR-222 was significantly upregulated in OSCC tissues and cells and regulated tumor progression by targeting CDKN1B.

Research progress and clinical application prospects of miRNAs in oral cancer

Oral cancer is one of the most common malignant tumors worldwide, and it is also one of the most important and difficult clinical problems to be solved. Due to the regional differences in diet culture, some areas have taken the 'hardest hit' of oral cancer cases. However, the existing clinical treatment methods (surgery as the main treatment method, radiotherapy and chemotherapy as the auxiliary ones) do not have satisfactory treatment effects; therefore, new diagnosis and treatment methods need to be developed and utilized. Micro RNAs (miRNAs), as a class of substances that play an important regulatory role in the development of tumors, have an important value in the diagnosis and treatment of various tumors. At the same time, many miRNAs have obvious expression differences in oral cancer tissues compared to normal tissues. Therefore, they may have diagnostic and therapeutic effects on oral cancer. In this review, we evaluate the miRNAs that play a regulatory role in the development of oral cancer and those that are expected to be applied in the diagnosis and treatment of oral cancer. At the same time, we summarize the important challenges that need to be addressed, aiming to provide evidence and suggestions for the application of miRNAs in the diagnosis and treatment of oral cancer.

Exosomes: Potential Biomarkers and Functions in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC), originating from the mucosal epithelial cells of the oral cavity, pharynx, and larynx, is a lethal malignancy of the head and neck. Patients with advanced and recurrent HNSCC have poor outcomes due to limited therapeutic options. Exosomes have active roles in the pathophysiology of tumors and are suggested as a potential therapeutic target of HNSCC. Exosomes in HNSCC have been intensively studied for disease activity, tumor staging, immunosuppression, and therapeutic monitoring. In this review, the biological mechanisms and the recent clinical application of exosomes are highlighted to reveal the potential of exosomes as biomarkers and therapeutic targets for HNSCC.

Small Extracellular Vesicles: Key Forces Mediating the Development and Metastasis of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide, and its incidence and mortality rates have been increasing annually in recent years. A variety of different small extracellular vesicles (sEVs) are important mediators of intercellular communication and have an important role in tumor metastasis and progression. The development and metastasis of CRC are closely linked to tumor-cell-derived sEVs, non-tumor-cell-derived sEVs, and intestinal-microbiota-derived sEVs. Numerous studies have shown that the tumor microenvironment (TME) is a key component in the regulation of CRC proliferation, development, and metastasis. These sEVs can create a TME conducive to CRC growth and metastasis by forming an immunosuppressive microenvironment, remodeling the extracellular matrix, and promoting tumor cell metabolism. Therefore, in this paper, we review the role of different types of sEVs in colorectal cancer development and metastasis. Furthermore, based on the properties of sEVs, we further discuss the use of sEVs as early biomarkers for colorectal cancer diagnosis and the potential for their use in the treatment of CRC.

Exosomal MiRNAs in Osteosarcoma: Biogenesis and Biological Functions

MiRNAs are a group of non-coding RNA molecules that function in mRNA translational inhibition via base-pairing with complementary sequences in target mRNA. In oncology, miRNAs have raised great attention due to their aberrant expression and pivotal roles in the pathogenesis of multiple malignancies including osteosarcoma. MiRNAs can be transported by exosome, the nano-extracellular vesicle with a diameter of 30–150 nm. Recently, a growing number of studies have demonstrated that exosomal miRNAs play a critical role in tumor initiation and progression, by exerting multiple biological functions including metastasis, angiogenesis, drug resistance and immunosuppression. In this review, we aim to depict the biogenesis of exosomal miRNAs and summarize the potential diagnostic and therapeutic functions of exosomal miRNAs in osteosarcoma.

Exosomal and Non-Exosomal MicroRNAs: New Kids on the Block for Cancer Therapy

MicroRNAs have been projected as promising tools for diagnostic and prognostic purposes in cancer. More recently, they have been highlighted as RNA therapeutic targets for cancer therapy. Though miRs perform a generic function of post-transcriptional gene regulation, their utility in RNA therapeutics mostly relies on their biochemical nature and their assembly with other macromolecules. Release of extracellular miRs is broadly categorized into two different compositions, namely exosomal (extracellular vesicles) and non-exosomal. This nature of miRs not only affects the uptake into target cells but also poses a challenge and opportunity for RNA therapeutics in cancer. By virtue of their ability to act as mediators of intercellular communication in the tumor microenvironment, extracellular miRs perform both, depending upon the target cell and target landscape, pro- and anti-tumor functions. Tumor-derived miRs mostly perform pro-tumor functions, whereas host cell- or stroma-derived miRs are involved in anti-tumor activities. This review deals with the recent understanding of exosomal and non-exosomal miRs in the tumor microenvironment, as a tool for pro- and anti-tumor activity and prospective exploit options for cancer therapy.

Emerging Role of Cancer-Associated Fibroblasts-Derived Exosomes in Tumorigenesis

Cancer-associated fibroblasts (CAFs) are the most important component of the stromal cell population in the tumor microenvironment and play an irreplaceable role in oncogenesis and cancer progression. Exosomes, a class of small extracellular vesicles, can transfer biological information (e.g., proteins, nucleic acids, and metabolites as messengers) from secreting cells to target recipient cells, thereby affecting the progression of human diseases, including cancers. Recent studies revealed that CAF-derived exosomes play a crucial part in tumorigenesis, tumor cell proliferation, metastasis, drug resistance, and the immune response. Moreover, aberrant expression of CAF-derived exosomal noncoding RNAs and proteins strongly correlates with clinical pathological characterizations of cancer patients. Gaining deeper insight into the participation of CAF-derived exosomes in tumorigenesis may lead to novel diagnostic biomarkers and therapeutic targets in human cancers.

More than a Bubble: Extracellular Vesicle microRNAs in Head and Neck Squamous Cell Carcinoma

Simple Summary

Head and neck squamous cell carcinoma (HNSCC) is an aggressive and lethal disease. Despite diagnostic and therapeutic advances, the overall survival of patients with advanced HNSCC remains poor. Recently, microRNAs in extracellular vesicles (EV-miRNAs) have been proposed as essential regulatory molecules involved in HNSCC. EV-miRNAs may serve as disease biomarkers and represent a novel therapeutic target. This review summarizes the current understanding of the role of EV-miRNAs in HNSCC as well as their potential future clinical applications.

Abstract

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that play a pivotal regulatory role in a broad variety of biological processes. Dysregulation of miRNAs is associated with several human diseases, particularly cancer. Extracellular vesicles (EVs) are crucial components in intercellular communication. As part of the cargo of EVs, miRNAs are involved in EV-mediated cell-to-cell interactions, including promotion or suppression of tumor development. The knowledge on the molecular mechanisms and clinical importance of EV-miRNAs in head and neck squamous cell carcinoma (HNSCC) has rapidly grown over the past years. In the present review, the current understanding regarding the effect of EV-miRNAs on HNSCC tumorigenesis is summarized, which includes effects on tumor proliferation, angiogenesis, invasion and metastasis, the tumor microenvironment, immune modulation, and treatment resistance. EV-miRNA-based biomarkers in liquid biopsies such as blood and saliva may open up new possibilities for employing EV-miRNAs for screening and early diagnostics as well as disease monitoring. Future perspectives include the promise of EV-miRNAs as a novel therapeutic target.

Liquid biopsy: Exosomal microRNAs as novel diagnostic and prognostic biomarkers in cancer

BACKGROUND

Detecting cancer at an early stage before clinical manifestation could be an effective strategy to decrease cancer mortality. Thus, identifying liquid biopsy biomarkers with high efficacy could be a promising approach for non-invasive diagnosis of cancer.

MAIN TEXT

Liquid biopsies are increasingly used as a supplement to biopsy, as it enables disease progression to be detected months before clinical and radiographic confirmation. Many bodily fluids contain exosomal microRNAs (miRNAs) which could provide a new class of biomarkers for early and minimally invasive cancer diagnosis due to the stability of miRNAs in exosomes. In this review, we mainly focused on the exosomal miRNAs (liquid biopsy) as biomarkers in the diagnosis and prognosis of various cancers.

CONCLUSION

Exosomal miRNAs can be used as diagnostic and prognosis biomarkers that provide unique insights and a more dynamic perspective of the progression and therapeutic responses in various malignancies. Therefore, the development of novel and more sensitive technologies that exploit exosomal miRNAs should be a priority for cancer management.

Modeling the Role of Cancer-Associated Fibroblasts in Tumor Cell Invasion

Simple Summary

Accurate in vitro modeling of diseases is essential to making breakthrough and clinically relevant discoveries. Assays to examine the process of invasion—a classical hallmark of cancer—have evolved over the years to overcome shortfalls in their design and accommodate new knowledge in the field, such as the role of the tumor microenvironment (TME) in propagating this process. The goals of this review are two-fold: To walk through the tried-and-true plus novel and new invasion assays currently used in cancer research with a focus on those incorporating cancer-associated fibroblasts (CAFs), and to be a resource for researchers to find the correct invasion assays that suit their own unique needs and biological questions.

Abstract

The major cause of cancer-related deaths can be attributed to the metastatic spread of tumor cells—a dynamic and complex multi-step process beginning with tumor cells acquiring an invasive phenotype to allow them to travel through the blood and lymphatic vessels to ultimately seed at a secondary site. Over the years, various in vitro models have been used to characterize specific steps in the cascade to collectively begin providing a clearer picture of the puzzle of metastasis. With the discovery of the TME’s supporting role in activating tumor cell invasion and metastasis, these models have evolved in parallel to accommodate features of the TME and to observe its interactions with tumor cells. In particular, CAFs that reside in reactive tumor stroma have been shown to play a substantial pro-invasive role through their matrix-modifying functions; accordingly, this warranted further investigation with the development and use of invasion assays that could include these stromal cells. This review explores the growing toolbox of assays used to study tumor cell invasion, from the simple beginnings of a tumor cell and extracellular matrix set-up to the advent of models that aim to more closely recapitulate the interplay between tumor cells, CAFs and the extracellular matrix. These models will prove to be invaluable tools to help tease out the intricacies of tumor cell invasion.

Flubendazole Plays an Important Anti-Tumor Role in Different Types of Cancers

Flubendazole, belonging to benzimidazole, is a broad-spectrum insect repellent and has been repurposed as a promising anticancer drug. In recent years, many studies have shown that flubendazole plays an anti-tumor role in different types of cancers, including breast cancer, melanoma, prostate cancer, colorectal cancer, and lung cancer. Although the anti-tumor mechanism of flubendazole has been studied, it has not been fully understood. In this review, we summarized the recent studies regarding the anti-tumor effects of flubendazole in different types of cancers and analyzed the related mechanisms, in order to provide the theoretical reference for further studies in the future.

Porcine Reproductive and Respiratory Syndrome Virus Evades Antiviral Innate Immunity via MicroRNAs Regulation

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important diseases in pigs, leading to significant economic losses in the swine industry worldwide. MicroRNAs (miRNAs) are small single-stranded non-coding RNAs involved in regulating gene expressions at the post-transcriptional levels. A variety of host miRNAs are dysregulated and exploited by PRRSV to escape host antiviral surveillance and help virus infection. In addition, PRRSV might encode miRNAs. In this review, we will summarize current progress on how PRRSV utilizes miRNAs for immune evasions. Increasing knowledge of the role of miRNAs in immune evasion will improve our understanding of PRRSV pathogenesis and help us develop new treatments for PRRSV-associated diseases.

Exosomal miRNAs and lncRNAs: The Modulator Keys of Cancer-Associated Fibroblasts in the Genesis and Progression of Malignant Neoplasms

The tumor microenvironment is made up of a universe of molecular and cellular components that promote or inhibit the development of neoplasms. Among the molecular elements are cytokines, metalloproteinases, proteins, mitochondrial DNA, and nucleic acids, within which the ncRNAs: miRNAs and lncRNAs stand out due to their direct modulating effects on the genesis and progression of various cancers. Regarding cellular elements, the solid tumor microenvironment is made up of tumor cells, healthy adjacent epithelial cells, immune system cells, endothelial cells, and stromal cells, such as cancer-associated fibroblasts, which are capable of generating a modulating communication network with the other components of the tumor microenvironment through, among other mechanisms, the secretion of exosomal vesicles loaded with miRNAs and lncRNAs. These ncRNAs are key pieces in developing neoplasms since they have diverse effects on cancer cells and healthy cells, favoring or negatively regulating protumoral cellular events, such as migration, invasion, proliferation, metastasis, epithelial-mesenchymal transition, and resistance to treatment. Due to the growing number of relevant evidence in recent years, this work focused on reviewing, analyzing, highlighting, and showing the current state of research on exosomal ncRNAs derived from cancer-associated fibroblasts and their effects on different neoplasms. A future perspective on using these ncRNAs as real therapeutic tools in the treatment of cancer patients is also proposed.

Cancer associated-fibroblast-derived exosomes in cancer progression

To identify novel cancer therapies, the tumor microenvironment (TME) has received a lot of attention in recent years in particular with the advent of clinical successes achieved by targeting immune checkpoint inhibitors (ICIs). The TME consists of multiple cell types that are embedded in the extracellular matrix (ECM), including immune cells, endothelial cells and cancer associated fibroblasts (CAFs), which communicate with cancer cells and each other during tumor progression. CAFs are a dominant and heterogeneous cell type within the TME with a pivotal role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis and chemotherapy resistance. CAFs mediate their effects in part by remodeling the ECM and by secreting soluble factors and extracellular vesicles. Exosomes are a subtype of extracellular vesicles (EVs), which contain various biomolecules such as nucleic acids, lipids, and proteins. The biomolecules in exosomes can be transmitted from one to another cell, and thereby affect the behavior of the receiving cell. As exosomes are also present in circulation, their contents can also be explored as biomarkers for the diagnosis and prognosis of cancer patients. In this review, we concentrate on the role of CAFs-derived exosomes in the communication between CAFs and cancer cells and other cells of the TME. First, we introduce the multiple roles of CAFs in tumorigenesis. Thereafter, we discuss the ways CAFs communicate with cancer cells and interplay with other cells of the TME, and focus in particular on the role of exosomes. Then, we elaborate on the mechanisms by which CAFs-derived exosomes contribute to cancer progression, as well as and the clinical impact of exosomes. We conclude by discussing aspects of exosomes that deserve further investigation, including emerging insights into making treatment with immune checkpoint inhibitor blockade more efficient.

miR-34c-5p mediates the cellular malignant behaviors of oral squamous cell carcinoma through targeted binding of TRIM29

Background

This investigation examined the effects of the microRNA miR-34c-5p on the proliferation, migration, and invasion of oral squamous cell carcinoma (OSCC) and the mechanisms involved.

Methods

The Gene Expression Omnibus (GEO) database was used to filter the chips, and the GEO2R software (https://www.ncbi.nlm.nih.gov/geo/geo2r/) was used to analyze the microarray data (GSE28100 and GSE45238). Gene set enrichment analysis (GSEA) was used to study the relationship between the expression of miR-34c-5p and the distant metastasis and pathological grade of OSCC. The correlation between TRIM29 (tripartite motif containing 29) expression and the malignant clinical phenotype of OSCC was also examined. The mRNA and protein expression levels of miR-34c-5p and TRIM29 were measured by real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot analysis. The proliferation, migration, invasion and apoptosis of the human oral squamous carcinoma cell lines CAL-27 and Tca8113 was assessed by performing cell-counting kit-8 (CCK-8) assays, colony formation assays, transwell tests, wound scratch tests and flow cytometry. Luciferase reporter assays were used to predict the relationship between miR-34c-5p and TRIM29. A xenograft nude model was established and used to evaluate the effect of miR-34c-5p on tumor growth in female BALB/c mice.

Results

The expression of miR-34c-5p was significantly correlated with the proliferation, migration, and metastasis of OSCC. Overexpression of miR-34c-5p promoted the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and suppressed their apoptosis. Inversely, low expression of miR-34c-5p suppressed the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and promoted their apoptosis. Overexpression of miR-34c-5p promoted tumor growth in the xenograft nude mice model. The expression of TRIM29 was related to malignant clinical phenotype of OSCC. Overexpression of TRIM29 inhibited the proliferation, migration and invasion of CAL-27 and Tca8113 cell, and induced their apoptosis. TRIM29 knockout had just the opposite effect. Importantly, miR-34c-5p binds to TRIM29 and inhibited TRIM29 expression.

Conclusions

MiR-34c-5p regulates the proliferation, migration, invasion, and apoptosis of OSCC through targeted binding of TRIM29. This may represent a novel therapeutic target for the treatment of patients with OSCC.

Footprints of microRNAs in Cancer Biology

MicroRNAs (miRNAs) are short non-coding RNAs involved in post-transcriptional gene regulation. Over the past years, various studies have demonstrated the role of aberrant miRNA expression in the onset of cancer. The mechanisms by which miRNA exerts its cancer-promoting or inhibitory effects are apparent through the various cancer hallmarks, which include selective proliferative advantage, altered stress response, vascularization, invasion and metastasis, metabolic rewiring, the tumor microenvironment and immune modulation; therefore, this review aims to highlight the association between miRNAs and the various cancer hallmarks by dissecting the mechanisms of miRNA regulation in each hallmark separately. It is hoped that the information presented herein will provide further insights regarding the role of cancer and serve as a guideline to evaluate the potential of microRNAs to be utilized as biomarkers and therapeutic targets on a larger scale in cancer research.

Liquid Biopsy as a Tool for the Characterisation and Early Detection of the Field Cancerization Effect in Patients with Oral Cavity Carcinoma

Oral squamous cell carcinoma (OSCC) constitutes approximately 25% of all head and neck cancer, for which the consumption of tobacco and alcohol are the main associated risk factors. The field cancerization effect of OSCC is one of the main reasons for the poor survival rates associated with this disease. Despite some advances, its ccharacterization and early diagnosis continue to challenge modern oncology, and the goal of improving the prognosis remains to be achieved. Among new early diagnostic tools for OSCC that have been proposed, liquid biopsy appears to be an ideal candidate, as studies have shown that the analysis of blood and saliva provides promising data for the early detection of relapses or second tumours.

lncRNA TUG1 promotes atherosclerosis progression by targeting miR-382-5p

OBJECTIVE

Atherosclerosis is a key risk factor for the initiation of cardiovascular disease, which results in high morbidity and mortality. lncRNA taurine upregulated gene 1 (TUG1) has been reported to participate in the development of atherosclerosis. Here, we aimed to investigate the interaction of TUG1 and miR-382-5p in regulating atherosclerosis progression.

METHODS

The levels of TUG1 and miR-382-5p in atherosclerotic serum samples and a cell model were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Pearson correlation analysis was then applied to TUG1 and miR-382-5p expression. Moreover, the interaction between TUG1 and miR-382-5p was confirmed by luciferase assay. The biological interaction between TUG1 and miR-382-5p was also dissected by loss of function analyses, including cell counting kit-8 (CCK-8) and Caspase-3 assays for cell proliferation and apoptosis, respectively, in oxidized low-density lipoprotein (ox-LDL)-treated human vascular smooth muscle cells (VSMCs).

RESULTS

TUG1 and miR-382-5p expressions were significantly increased and decreased, respectively, in both atherosclerotic serum samples and a cell model. In addition, the expression of TUG1 was negatively correlated with the level of miR-382-5p in atherosclerotic serum samples. Moreover, silencing of TUG1 reduced cell growth and enhanced the apoptosis of ox-LDL-treated VSMCs. Notably, a miR-382-5p inhibitor significantly reversed the effect of TUG1 downregulation on ox-LDL-treated VSMCs, which aggravates the process of atherosclerosis.

CONCLUSION

TUG1 can aggravate atherosclerosis progression by reducing the expression of miR-382-5p. This study provides an effective treatment target of atherosclerosis patients based on the TUG1-miR-382-5p axis.

Small Extracellular Vesicles and Metastasis-Blame the Messenger

Simple Summary

Due to their systemic nature, metastatic lesions are a major problem for curative cancer treatment. According to a common model for metastasis, tumor cells disseminate by local invasion, survival in the blood stream and extravasation into suitable tissue environments. At secondary sites, metastatic cells adapt, proliferate and foster vascularization to satisfy nutrient and oxygen demand. In recent years, tumors were shown to extensively communicate with cells in the local microenvironment and future metastatic sites by secreting small extracellular vesicles (sEVs, exosomes). sEVs deliver bioactive cargos, e.g., proteins, and in particular, several nucleic acid classes to reprogram target cells, which in turn facilitate tumor growth, cell motility, angiogenesis, immune evasion and establishment of pre-metastatic niches. sEV-cargos also act as biomarkers for diagnosis and prognosis. This review discusses how tumor cells utilize sEVs with nucleic acid cargos to progress through metastasis, and how sEVs may be employed for prognosis and treatment.

Abstract

Cancer is a complex disease, driven by genetic defects and environmental cues. Systemic dissemination of cancer cells by metastasis is generally associated with poor prognosis and is responsible for more than 90% of cancer deaths. Metastasis is thought to follow a sequence of events, starting with loss of epithelial features, detachment of tumor cells, basement membrane breakdown, migration, intravasation and survival in the circulation. At suitable distant niches, tumor cells reattach, extravasate and establish themselves by proliferating and attracting vascularization to fuel metastatic growth. These processes are facilitated by extensive cross-communication of tumor cells with cells in the primary tumor microenvironment (TME) as well as at distant pre-metastatic niches. A vital part of this communication network are small extracellular vesicles (sEVs, exosomes) with a size of 30–150 nm. Tumor-derived sEVs educate recipient cells with bioactive cargos, such as proteins, and in particular, major nucleic acid classes, to drive tumor growth, cell motility, angiogenesis, immune evasion and formation of pre-metastatic niches. Circulating sEVs are also utilized as biomarker platforms for diagnosis and prognosis. This review discusses how tumor cells facilitate progression through the metastatic cascade by employing sEV-based communication and evaluates their role as biomarkers and vehicles for drug delivery.

Stromal cells in the tumor microenvironment promote the progression of oral squamous cell carcinoma

The stromal cells in the tumor microenvironment (TME) can influence the progression of multiple types of cancer; however, data on oral squamous cell carcinoma (OSCC) are limited. In the present study, the effects of verrucous squamous cell carcinoma-associated stromal cells (VSCC-SCs), squamous cell carcinoma-associated stromal cells (SCC-SCs) and human dermal fibroblasts (HDFs) on the tumor nest formation, proliferation, invasion and migration of HSC-3 cells were examined in vitro using Giemsa staining, MTS, and Transwell (invasion and migration) assays, respectively. The results revealed that both the VSCC-SCs and SCC-SCs inhibited the tumor nest formation, and promoted the proliferation, invasion and migration of OSCC cells in vitro. Furthermore, the effects of VSCC-SCs, SCC-SCs and HDFs on the differentiation, proliferation, invasion and migration of OSCC cells in vivo were evaluated by hematoxylin and eosin staining, tartrate-resistant acid phosphatase staining, immunohistochemistry and double-fluorescent immunohistochemical staining, respectively. The results demonstrated that the VSCC-SCs promoted the differentiation, proliferation, invasion and migration of OSCC cells, while the SCC-SCs inhibited the differentiation, and promoted the proliferation, invasion and migration of OSCC cells in vivo. Finally, microarray data were used to predict genes in VSCC-SCs and SCC-SCs that may influence the progression of OSCC, and those with potential to influence the differential effects of VSCC-SCs and SCC-SCs on the differentiation of OSCC. It was found that C-X-C motif chemokine ligand (CXCL)8, mitogen-activated protein kinase 3 (MAPK3), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), C-X-C motif chemokine ligand 1 (CXCL1) and C-C motif chemokine ligand 2 (CCL2) may be involved in the crosstalk between VSCC-SCs, SCC-SCs and OSCC cells, which regulates the progression of OSCC. Intercellular adhesion molecule 1 (ICAM1), interleukin (IL)1B, Fos proto-oncogene, AP-1 transcription factor subunit (FOS), bone morphogenetic protein 4 (BMP4), insulin (INS) and nerve growth factor (NGF) may be responsible for the differential effects of VSCC-SCs and SCC-SCs on the differentiation of OSCC. On the whole, the present study demonstrates that both VSCC-SCs and SCC-SCs may promote the progression of OSCC, and SCC-SCs were found to exert a more prominent promoting effect; this may represent a potential regulatory mechanism for the progression of OSCC.

CAFs Interacting With TAMs in Tumor Microenvironment to Enhance Tumorigenesis and Immune Evasion

Cancer associated fibroblasts (CAFs) and tumor associated macrophages (TAMs) are among the most important and abundant players of the tumor microenvironment. CAFs as well as TAMs are known to play pivotal supportive roles in tumor growth and progression. The number of CAF or TAM cells is mostly correlated with poor prognosis. Both CAFs and TAMs are in a reciprocal communication with the tumor cells in the tumor milieu. In addition to such interactions, CAFs and TAMs are also involved in a dynamic and reciprocal interrelationship with each other. Both CAFs and TAMs are capable of altering each other's functions. Here, the current understanding of the distinct mechanisms about the complex interplay between CAFs and TAMs are summarized. In addition, the consequences of such a mutual relationship especially for tumor progression and tumor immune evasion are highlighted, focusing on the synergistic pleiotropic effects. CAFs and TAMs are crucial components of the tumor microenvironment; thus, they may prove to be potential therapeutic targets. A better understanding of the tri-directional interactions of CAFs, TAMs and cancer cells in terms of tumor progression will pave the way for the identification of novel theranostic cues in order to better target the crucial mechanisms of carcinogenesis.

circ_0005962 functions as an oncogene to aggravate NSCLC progression

Background

Non-small cell lung cancer (NSCLC) is a leading threat to human lives with high incidence and mortality. Circular RNAs were reported to play important roles in human cancers. The purpose of this study was to investigate the role of circ_0005962 and explore the underlying functional mechanisms.

Methods

The protein levels of Beclin 1, light chain3 (LC3-II/LC3-I), Pyruvate dehydrogenase kinase 4 (PDK4), Cleaved Caspase 3 (C-caspase 3), and proliferating cell nuclear antigen were examined using western blot analysis. Glycolysis was determined according to the levels of glucose consumption and lactate production. Xenograft model was constructed to investigate the role of circ_0005962 in vivo.

Result

circ_0005962 expressed with a high level in NSCLC tissues and cells. circ_0005962 knockdown inhibited proliferation, autophagy, and glycolysis but promoted apoptosis in NSCLC cells. miR-382-5p was targeted by circ_0005962, and its inhibition reversed the role of circ_0005962 knockdown. Besides, PDK4, a target of miR-382-5p, was regulated by circ_0005962 through miR-382-5p, and its overexpression abolished the effects of miR-382-5p reintroduction. circ_0005962 knockdown suppressed tumor growth in vivo.

Conclusion

circ_0005962 knockdown restrained cell proliferation, autophagy, and glycolysis but stimulated apoptosis through modulating the circ_0005962/miR-382-5p/PDK4 axis. Our study broadened the insights into understanding the mechanism of NSCLC progression.

Cancer-Associated Fibroblasts in Oral Cancer: A Current Perspective on Function and Potential for Therapeutic Targeting

The role of the tumour microenvironement (TME) in cancer progression and resistance to therapies is now widely recognized. The most prominent non-immune cell type in the microenvironment of oral cancer (OSCC) is cancer-associated fibroblasts (CAF). Although CAF are a poorly characterised and heterogenous cell population, those with an "activated" myofibroblastic phenotype have been shown to support OSCC progression, promoting growth, invasion and numerous other "hallmarks of malignancy." CAF also confer broad resistance to different types of therapy, including chemo/radiotherapy and EGFR inhibitors; consistent with this, CAF-rich OSCC are associated with poor prognosis. In recent years, much CAF research has focused on their immunological role in the tumour microenvironment, showing that CAF shield tumours from immune attack through multiple mechanisms, and particularly on their role in promoting resistance to anti-PD-1/PD-L1 checkpoint inhibitors, an exciting development for the treatment of recurrent/metastatic oral cancer, but which fails in most patients. This review summarises our current understanding of CAF subtypes and function in OSCC and discusses the potential for targeting these cells therapeutically.

Effects of CAF-Derived MicroRNA on Tumor Biology and Clinical Applications

Cancer-associated fibroblasts (CAFs), prominent cell components of the tumor microenvironment (TME) in most types of solid tumor, play an essential role in tumor cell growth, proliferation, invasion, migration, and chemoresistance. MicroRNAs (miRNAs) are small, non-coding, single-strand RNAs that negatively regulate gene expression by post-transcription modification. Increasing evidence has suggested the dysregulation of miRNAs in CAFs, which facilitates the conversion of normal fibroblasts (NFs) into CAFs, then enhances the tumor-promoting capacity of CAFs. To understand the process of tumor progression, as well as the development of chemoresistance, it is important to explore the regulatory function of CAF-derived miRNAs and the associated molecular mechanisms, which may become potential diagnostic and prognostic biomarkers and targets of anti-tumor therapeutics. In this review, we describe miRNAs that are differentially expressed by NFs and CAFs, summarize the modulating role of CAF-derived miRNAs in fibroblast activation and tumor advance, and eventually identify a potential clinical application for CAF-derived miRNAs as diagnostic/prognostic biomarkers and therapeutic targets in several tumors.