Essential role for TrpC5-containing extracellular vesicles in breast cancer with chemotherapeutic resistance

Tumor-derived exosomes as promising tools for cancer diagnosis and therapy

Mounting evidences indicated that cancer cell-derived exosomes (TDEs) contribute to cancer progression and metastasis by reshaping the tumor microenvironment (TME) and interfering immunity response. TDEs contain unique biomolecular cargo, consisting of protein, nucleic acid, and lipids. In recent years, TDEs have been used as potential disease therapeutics and diagnosis biomarkers and prime candidates as delivery tools for cancer treatment. In the present review, we firstly summarized TDEs biogenesis and characteristic. Also, the role of TDEs in cancer cell metastasis and invasiveness, drug resistance, and immunosuppression was mentioned via cell-cell communication. Additionally, we concluded the current strategies for TDE-based cancer therapy, including TDEs inhibition and clearance, usage as therapeutic drug delivery vector and cancer vaccines. Furthermore, combination therapy with engineered TDEs were summarized, such as radiotherapy, photodynamic therapy, photothermal therapy, and sonodynamic therapy. Consequently, the above opens up novel and interesting opportunities for cancer diagnosis and prognosis based on TDEs, which is prospective to accelerate the clinical translation of TDEs for cancer therapy.

Stress-induced extracellular vesicles: insight into their altered proteomic composition and probable physiological role in cancer

EVs (extracellular vesicles) are phospholipid bilayer vesicles that can be released by both prokaryotic and eukaryotic cells in normal as well as altered physiological conditions. These vesicles also termed as signalosomes, possess a distinctive cargo comprising nucleic acids, proteins, lipids, and metabolites, enabling them to play a pivotal role in both local and long-distance intercellular communication. The composition, origin, and release of EVs can be influenced by different physiological conditions and a variety of stress factors, consequently affecting the contents carried within these vesicles. Therefore, identifying the modified contents of EVs can provide valuable insights into their functional role in stress-triggered communication. Particularly, this is important when EVs released from tumor microenvironment are investigated for their role in the development and dissemination of cancer. This review article emphasizes the importance of differential EV shedding and altered proteomic content in response to reduced oxygen concentration, altered levels of glucose and glutamine, pH variations, oxidative stress and Ca2+ ion concertation and it is subsequent effects on the behavior of recipient cells.

Exosomes and breast cancer angiogenesis; Highlights in intercellular communication

Breast cancer (BC) is a prevalent and highly lethal cancer in females. Like other cancer types, the intricate cellular and molecular heterogeneity leads to the variation of therapeutic outcomes. The development and progression of blood vessels increase the tumor cell expansion and metastasis to remote sites. Based on several pieces of scientific data, different mediators and cells are involved in the promotion of angiogenesis into the tumor parenchyma. Recent data have indicated the critical role of extracellular vesicles, especially exosomes (Exos), in the transfer of angiogenesis molecules between the BC cells. Due to unique physicochemical properties, and the transfer of certain signaling molecules, Exos are at the center of attention in terms of biomarkers and therapeutic bullets in cancer patients. Along with these statements, understanding the modulatory role of Exos in BC angiogenesis seems critical in the clinical setting. Here, the mechanisms by which BC cells can orchestrate the angiogenesis phenomenon via Exos are discussed in detail. The present study can help us to understand the pro-/anti-angiogenesis role of Exos in BC and to design better oncostatic strategies.

Patient-Derived Organoids on a Microarray for Drug Resistance Study in Breast Cancer

Drug resistance is always a challenge in cancer treatment, whether for chemotherapy, targeting, or immunotherapy. Although tumor cell lines are derived from cancer patients, they gradually lost the original characteristics, including heterogeneity and tumor microenvironment (TME), during the long period of in vitro culturing. Therefore, it is urgent to use patient-derived tumor models instead of cancer cell lines to study tumor drug resistance. Herein, we developed a microarray device that serves as a platform for high-throughput and three-dimensional culture of breast cancer patient-derived organoids (BCOs) and investigated their resistance to adriamycin (ADM). Coupled with fluorescence microscopy, this system enabled on-chip drug response monitoring and cell viability assessment without the consumption of a large number of tumor cells. The organoids were divided into a resistant BCO group (RBCO) and a sensitive BCO group (SBCO) according to their half-inhibitory concentration (IC50). Different from cancer cell lines, BCOs demonstrated obvious heterogeneity in drug treatment. Ivermectin (IVM), a broad-spectrum antiparasitic agent approved by the Food and Drug Administration (FDA), was observed to synergistically augment ADM-induced cytotoxicity in organoids. The BCO chip provides a promising platform for investigation of drug resistance and preclinical drug screening based on clinical samples.

Unlocking the Secrets of Extracellular Vesicles: Orchestrating Tumor Microenvironment Dynamics in Metastasis, Drug Resistance, and Immune Evasion

Extracellular vehicles (EVs) are gaining increasing recognition as central contributors to the intricate landscape of the tumor microenvironment (TME). This manuscript provides an extensive examination of the multifaceted roles played by EVs in shaping the TME, with a particular emphasis on their involvement in metastasis, drug resistance, and immune evasion. Metastasis, the process by which cancer cells disseminate to distant sites, remains a formidable challenge in cancer management. EVs, encompassing exosomes and microvesicles, have emerged as critical participants in this cascade of events. They facilitate the epithelial-to-mesenchymal transition (EMT), foster pre-metastatic niche establishment, and enhance the invasive potential of cancer cells. This manuscript delves into the intricate molecular mechanisms underpinning these processes, underscoring the therapeutic potential of targeting EVs to impede metastasis. Drug resistance represents a persistent impediment to successful cancer treatment. EVs are instrumental in intrinsic and acquired drug resistance, acting as mediators of intercellular communication. They ferry molecules like miRNAs and proteins, which confer resistance to conventional chemotherapy and targeted therapies. This manuscript scrutinizes the diverse strategies employed by EVs in propagating drug resistance while also considering innovative approaches involving EV-based drug delivery systems to counteract this phenomenon. Immune evasion is a hallmark of cancer, and EVs are central in sculpting the immunosuppressive milieu of the TME. Tumor-derived EVs thwart immune responses through various mechanisms, including T cell dysfunction induction, the expansion of regulatory T cells (Tregs), and polarization of macrophages towards an immunosuppressive phenotype. In addition, the manuscript explores the diagnostic potential of EVs as biomarkers and their role as therapeutic agents in immune checkpoint blockade therapies. This manuscript provides a comprehensive overview of EV's pivotal role in mediating intricate interactions within the TME, ultimately influencing cancer progression and therapeutic outcomes. A profound understanding of EV-mediated processes in metastasis, drug resistance, and immune evasion opens up promising avenues for developing innovative therapeutic strategies and identifying valuable biomarkers in the ongoing battle against cancer.

Chemoresistance and the tumor microenvironment: the critical role of cell-cell communication

Resistance of cancer cells to anticancer drugs remains a major challenge in modern medicine. Understanding the mechanisms behind the development of chemoresistance is key to developing appropriate therapies to counteract it. Nowadays, with advances in technology, we are paying more and more attention to the role of the tumor microenvironment (TME) and intercellular interactions in this process. We also know that important elements of the TME are not only the tumor cells themselves but also other cell types, such as mesenchymal stem cells, cancer-associated fibroblasts, stromal cells, and macrophages. TME elements can communicate with each other indirectly (via cytokines, chemokines, growth factors, and extracellular vesicles [EVs]) and directly (via gap junctions, ligand-receptor pairs, cell adhesion, and tunnel nanotubes). This communication appears to be critical for the development of chemoresistance. EVs seem to be particularly interesting structures in this regard. Within these structures, lipids, proteins, and nucleic acids can be transported, acting as signaling molecules that interact with numerous biochemical pathways, thereby contributing to chemoresistance. Moreover, drug efflux pumps, which are responsible for removing drugs from cancer cells, can also be transported via EVs.

Recent advances to address challenges in extracellular vesicle-based applications for lung cancer

Lung cancer, highly prevalent and the leading cause of cancer-related death globally, persists as a significant challenge due to the lack of definitive tumor markers for early diagnosis and personalized therapeutic interventions. Recently, extracellular vesicles (EVs), functioning as natural carriers for intercellular communication, have received increasing attention due to their ability to traverse biological barriers and deliver diverse biological cargoes, including cytosolic proteins, cell surface proteins, microRNA, lncRNA, circRNA, DNA, and lipids. EVs are increasingly recognized as a valuable resource for non-invasive liquid biopsy, as well as drug delivery platforms, and anticancer vaccines for precision medicine in lung cancer. Herein, given the diagnostic and therapeutic potential of tumor-associated EVs for lung cancer, we discuss this topic from a translational standpoint. We delve into the specific roles that EVs play in lung cancer carcinogenesis and offer a particular perspective on how advanced engineering technologies can overcome the current challenges and expedite and/or enhance the translation of EVs from laboratory research to clinical settings.

5-Fluorouracil resistant CRC cells derived exosomes promote cancer-associated fibroblasts secreting more CXCL12

Background: Chemoresistance is a key reason for treatment failure in colorectal cancer (CRC) patients. The tumor microenvironment of chemoresistant CRC is distinctly immunosuppressive, although the underlying mechanisms are unclear. Methods: The CRC data sets GSE69657 and GSE62080 were downloaded from the GEO database, and the correlation between TRPC5 and FAP expression was analyzed by Pearson method. The in-situ expression of transient receptor potential channel 5 (TRPC5) and fibroblast activation protein (FAP) in the CRC tissues was examined by immunohistochemistry. TRPC5 expression levels in the HCT8 and HCT116 cell lines and the corresponding 5-fluorouracil (5-FU)-resistant cell lines (HCT8R and HCT116R) were analyzed by western blotting and RT-PCR. Exosomes were isolated from the HCT8R and HCT116R cells and incubated with colorectal normal fibroblasts (NFs), and cancer-associated fibroblasts (CAFs)markers were detected. NFs were also incubated with exosomes isolated from TRPC5-knockdown HCT8R cells, and the changes in intracellular Ca2+ levels and C-X-C motif chemokine ligand 12 (CXCL12) secretion were analyzed. Results: TRPC5 and FAP expression showed positive correlation in the datasets. Immunostaining of CRC tissue specimens further revealed that high TRPC5 and FAP expressions were significantly associated with worse tumor regression. Furthermore, chemoresistant CRC cells expressed higher levels of TRPC5 compared to the chemosensitive cells, and knocking down TRPC5 reversed chemoresistance. Exosomes derived from CRC cells induced the transformation of NFs to CAFs. However, TRPC5-exosomes derived from chemoresistant CRC cells can promote CAFs to secrete more CXCL12. Conclusion: Chemoresistant CRC cells can induce CAFs activation and promote CXCL12 secretion through exosomal TRPC5.

Dysregulation of calcium homeostasis in cancer and its role in chemoresistance

Globally, cancer, as a major public health concern, poses a severe threat to people's well-being. Advanced and specialized therapies can now cure the majority of people with early-stage cancer. However, emerging resistance to traditional and novel chemotherapeutic drugs remains a serious issue in clinical medicine. Chemoresistance often leads to cancer recurrence, metastasis, and increased mortality, accounting for 90% of chemotherapy failures. Thus, it is important to understand the molecular mechanisms of chemoresistance and find novel therapeutic approaches for cancer treatment. Among the several factors responsible for chemoresistance, calcium (Ca2+) dysregulation plays a significant role in cancer progression and chemoresistance. Therefore, targeting this derailed Ca2+ signalling for cancer therapy has become an emerging research area. Of note, the Ca2+ signal and its proteins are a multifaceted and potent tool by which cells achieve specific outcomes. Depending on cell survival needs, Ca2+ is either upregulated or downregulated in both chemosensitive and chemoresistant cancer cells. Consequently, the appropriate treatment should be selected based on Ca2+ signalling dysregulation. This review discusses the role of Ca2+ in cancer cells and the targeting of Ca2+ channels, pumps, and exchangers. Furthermore, we have emphasised the role of Ca2+ in chemoresistance and therapeutic strategies. In conclusion, targeting Ca2+ signalling is a multifaceted process. Methods such as site-specific drug delivery, target-based drug-designing, and targeting two or more Ca2+ proteins simultaneously may be explored; however, further clinical studies are essential to validate Ca2+ blockers' anti-cancer efficacy.

Diagnostic potential of exosomal extracellular vesicles in oncology

Liquid biopsy can detect circulating cancer cells or tumor cell-derived DNA at various stages of cancer. The fluid from these biopsies contains extracellular vesicles (EVs), such as apoptotic bodies, microvesicles, exomeres, and exosomes. Exosomes contain proteins and nucleic acids (DNA/RNA) that can modify the microenvironment and promote cancer progression, playing significant roles in cancer pathology. Clinically, the proteins and nucleic acids within the exosomes from liquid biopsies can be biomarkers for the detection and prognosis of cancer. We review EVs protein and miRNA biomarkers identified for select cancers, specifically melanoma, glioma, breast, pancreatic, hepatic, cervical, prostate colon, and some hematological malignancies. Overall, this review demonstrates that EV biomolecules have great potential to expand the diagnostic and prognostic biomarkers used in Oncology; ultimately, EVs could lead to earlier detection and novel therapeutic targets. Clinical implicationsEVs represent a new paradigm in cancer diagnostics and therapeutics. The potential use of exosomal contents as biomarkers for diagnostic and prognostic indicators may facilitate cancer management. Non-invasive liquid biopsy is helpful, especially when the tumor is difficult to reach, such as in pancreatic adenocarcinoma. Moreover, another advantage of using minimally invasive liquid biopsy is that monitoring becomes more manageable. Identifying tumor-derived exosomal proteins and microRNAs would allow a more personalized approach to detecting cancer and improving treatment.

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.

The Role of Intracellular and Extracellular Vesicles in the Development of Therapy Resistance in Cancer

Cancer is the second leading cause of global mortality and claims approximately 10 million lives annually. Despite advances in treatments such as surgery, chemotherapy, and immunotherapy, resistance to these methods has emerged. Multidrug resistance (MDR), where cancer cells resist diverse treatments, undermines therapy effectiveness, escalating mortality rates. MDR mechanisms include, among others, drug inactivation, reduced drug uptake, enhanced DNA repair, and activation of survival pathways such as autophagy. Moreover, MDR mechanisms can confer resistance to other therapies like radiotherapy. Understanding these mechanisms is crucial for improving treatment efficacy and identifying new therapeutic targets. Extracellular vesicles (EVs) have gathered attention for their role in cancer progression, including MDR development through protein transfer and genetic reprogramming. Autophagy, a process balancing cellular resources, also influences MDR. The intersection of EVs and autophagy further complicates the understanding of MDR. Both extracellular (exosomes, microvesicles) and intracellular (autophagic) vesicles contribute to therapy resistance by regulating the tumor microenvironment, facilitating cell communication, and modulating drug processing. While much is known about these pathways, there is still a need to explore their potential for predicting treatment responses and understanding tumor heterogeneity.

TRPC3 signalling contributes to the biogenesis of extracellular vesicles

Extracellular vesicles (EVs) contribute to a wide range of pathological processes including cancer progression, yet the molecular mechanisms underlying their biogenesis remain incompletely characterized. The development of tetraspanin-based pHluorin reporters has enabled the real-time analysis of EV release at the plasma membrane. Here, we employed CD81-pHluorin to investigate mechanisms of EV release in ovarian cancer (OC) cells and report a novel role for the Ca2+-permeable transient receptor potential (TRP) channel TRPC3 in EV-mediated communication. We found that specific activation of TRPC3 increased Ca2+ signalling in SKOV3 cells and stimulated an immediate increase in EV release. Ca2+-stimulants histamine and ionomycin likewise induced EV release, and imaging analysis revealed distinct stimulation-dependent temporal and spatial release dynamics. Interestingly, inhibition of TRPC3 attenuated histamine-stimulated Ca2+-entry and EV release, indicating that TRPC3 is likely to act downstream of histamine signalling in EV biogenesis. Furthermore, we found that direct activation of TRPC3 as well as the application of EVs derived from TRPC3-activated cells increased SKOV3 proliferation. Our data provides insights into the molecular mechanisms and dynamics underlying EV release in OC cells, proposing a key role for TRPC3 in EV biogenesis.

Comprehensive Overview the Role of Glycosylation of Extracellular Vesicles in Cancers

Extracellular vesicles (EVs) are membranous structures secreted by various cells carrying diverse biomolecules. Recent advancements in EV glycosylation research have underscored their crucial role in cancer. This review provides a global overview of EV glycosylation research, covering aspects such as specialized techniques for isolating and characterizing EV glycosylation, advances on how glycosylation affects the biogenesis and uptake of EVs, and the involvement of EV glycosylation in intracellular protein expression, cellular metastasis, intercellular interactions, and potential applications in immunotherapy. Furthermore, through an extensive literature review, we explore recent advances in EV glycosylation research in the context of cancer, with a focus on lung, colorectal, liver, pancreatic, breast, ovarian, prostate, and melanoma cancers. The primary objective of this review is to provide a comprehensive update for researchers, whether they are seasoned experts in the field of EVs or newcomers, aiding them in exploring new avenues and gaining a deeper understanding of EV glycosylation mechanisms. This heightened comprehension not only enhances researchers' knowledge of the pathogenic mechanisms of EV glycosylation but also paves the way for innovative cancer diagnostic and therapeutic strategies.

The Diversity of Liquid Biopsies and Their Potential in Breast Cancer Management

Analyzing blood as a so-called liquid biopsy in breast cancer (BC) patients has the potential to adapt therapy management. Circulating tumor cells (CTCs), extracellular vesicles (EVs), cell-free DNA (cfDNA) and other blood components mirror the tumoral heterogeneity and could support a range of clinical decisions. Multi-cancer early detection tests utilizing blood are advancing but are not part of any clinical routine yet. Liquid biopsy analysis in the course of neoadjuvant therapy has potential for therapy (de)escalation.Minimal residual disease detection via serial cfDNA analysis is currently on its way. The prognostic value of blood analytes in early and metastatic BC is undisputable, but the value of these prognostic biomarkers for clinical management is controversial. An interventional trial confirmed a significant outcome benefit when therapy was changed in case of newly emerging cfDNA mutations under treatment and thus showed the clinical utility of cfDNA analysis for therapy monitoring. The analysis of PIK3CA or ESR1 variants in plasma of metastatic BC patients to prescribe targeted therapy with alpesilib or elacestrant has already arrived in clinical practice with FDA-approved tests available and is recommended by ASCO. The translation of more liquid biopsy applications into clinical practice is still pending due to a lack of knowledge of the analytes' biology, lack of standards and difficulties in proving clinical utility.

Role of exosomes in the development, diagnosis, prognosis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. It is characterized by occult onset resulting in most patients being diagnosed at advanced stages and with poor prognosis. Exosomes are nanoscale vesicles with a lipid bilayer envelope released by various cells under physiological and pathological conditions, which play an important role in the biological information transfer between cells. There is growing evidence that HCC cell-derived exosomes may contribute to the establishment of a favorable microenvironment that supports cancer cell proliferation, invasion, and metastasis. These exosomes not only provide a versatile platform for diagnosis but also serve as a vehicle for drug delivery. In this paper, we review the role of exosomes involved in the proliferation, migration, and metastasis of HCC and describe their application in HCC diagnosis and treatment. We also discuss the prospects of exosome application in HCC and the research challenges.

Doxorubicin and other anthracyclines in cancers: Activity, chemoresistance and its overcoming

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action. The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

TRP Channels: The Neglected Culprits in Breast Cancer Chemotherapy Resistance?

Breast cancer is a major health concern worldwide, and resistance to therapies remains a significant challenge in treating this disease. In breast cancer, Transient Receptor Potential (TRP) channels are well studied and constitute key players in nearly all carcinogenesis hallmarks. Recently, they have also emerged as important actors in resistance to therapy by modulating the response to various pharmaceutical agents. Targeting TRP channels may represent a promising approach to overcome resistance to therapies in breast cancer patients.

Identification of Potential Protein Targets in Extracellular Vesicles Isolated from Chemotherapy-Treated Ovarian Cancer Cells

Despite the ongoing clinical trials and the introduction of novel treatments over the past few decades, ovarian cancer remains one of the most fatal malignancies in women worldwide. Platinum- and paclitaxel-based chemotherapy is effective in treating the majority of patients with ovarian cancer. However, more than 70% of patients experience recurrence and eventually develop chemoresistance. To improve clinical outcomes in patients with ovarian cancer, novel technologies must be developed for identifying molecular alterations following drug-based treatment of ovarian cancer. Recently, extracellular vesicles (EVs) have gained prominence as the mediators of tumor progression. In this study, we used mass spectrometry to identify the changes in EV protein signatures due to different chemotherapeutic agents used for treating ovarian cancer. By examining these alterations, we identified the specific protein induction patterns of cisplatin alone, paclitaxel alone, and a combination of cisplatin and paclitaxel. Specifically, we found that drug sensitivity was correlated with the expression levels of ANXA5, CD81, and RAB5C in patients receiving cisplatin with paclitaxel. Our findings suggest that chemotherapy-induced changes in EV protein signatures are crucial for the progression of ovarian cancer.

Deciphering the Functional Status of Breast Cancers through the Analysis of Their Extracellular Vesicles

Breast cancer (BC) accounts for the highest incidence of tumor-related mortality among women worldwide, justifying the growing search for molecular tools for the early diagnosis and follow-up of BC patients under treatment. Circulating extracellular vesicles (EVs) are membranous nanocompartments produced by all human cells, including tumor cells. Since minimally invasive methods collect EVs, which represent reservoirs of signals for cell communication, these particles have attracted the interest of many researchers aiming to improve BC screening and treatment. Here, we analyzed the cargoes of BC-derived EVs, both proteins and nucleic acids, which yielded a comprehensive list of potential markers divided into four distinct categories, namely, (i) modulation of aggressiveness and growth; (ii) preparation of the pre-metastatic niche; (iii) epithelial-to-mesenchymal transition; and (iv) drug resistance phenotype, further classified according to their specificity and sensitivity as vesicular BC biomarkers. We discuss the therapeutic potential of and barriers to the clinical implementation of EV-based tests, including the heterogeneity of EVs and the available technologies for analyzing their content, to present a consistent, reproducible, and affordable set of markers for further evaluation.

Extracellular Vesicles and Cancer Multidrug Resistance: Undesirable Intercellular Messengers?

Cancer multidrug resistance (MDR) is one of the main mechanisms contributing to therapy failure and mortality. Overexpression of drug transporters of the ABC family (ATP-binding cassette) is a major cause of MDR. Extracellular vesicles (EVs) are nanoparticles released by most cells of the organism involved in cell-cell communication. Their cargo mainly comprises, proteins, nucleic acids, and lipids, which are transferred from a donor cell to a target cell and lead to phenotypical changes. In this article, we review the scientific evidence addressing the regulation of ABC transporters by EV-mediated cell-cell communication. MDR transfer from drug-resistant to drug-sensitive cells has been identified in several tumor entities. This was attributed, in some cases, to the direct shuttle of transporter molecules or its coding mRNA between cells. Also, EV-mediated transport of regulatory proteins (e.g., transcription factors) and noncoding RNAs have been indicated to induce MDR. Conversely, the transfer of a drug-sensitive phenotype via EVs has also been reported. Additionally, interactions between non-tumor cells and the tumor cells with an impact on MDR are presented. Finally, we highlight uninvestigated aspects and possible approaches to exploiting this knowledge toward the identification of druggable processes and molecules and, ultimately, the development of novel therapeutic strategies.

TRP (transient receptor potential) ion channel family: structures, biological functions and therapeutic interventions for diseases

Transient receptor potential (TRP) channels are sensors for a variety of cellular and environmental signals. Mammals express a total of 28 different TRP channel proteins, which can be divided into seven subfamilies based on amino acid sequence homology: TRPA (Ankyrin), TRPC (Canonical), TRPM (Melastatin), TRPML (Mucolipin), TRPN (NO-mechano-potential, NOMP), TRPP (Polycystin), TRPV (Vanilloid). They are a class of ion channels found in numerous tissues and cell types and are permeable to a wide range of cations such as Ca²⁺, Mg²⁺, Na⁺, K⁺, and others. TRP channels are responsible for various sensory responses including heat, cold, pain, stress, vision and taste and can be activated by a number of stimuli. Their predominantly location on the cell surface, their interaction with numerous physiological signaling pathways, and the unique crystal structure of TRP channels make TRPs attractive drug targets and implicate them in the treatment of a wide range of diseases. Here, we review the history of TRP channel discovery, summarize the structures and functions of the TRP ion channel family, and highlight the current understanding of the role of TRP channels in the pathogenesis of human disease. Most importantly, we describe TRP channel-related drug discovery, therapeutic interventions for diseases and the limitations of targeting TRP channels in potential clinical applications.

Impact of the Cancer Cell Secretome in Driving Breast Cancer Progression

Breast cancer is a complex and heterogeneous disease resulting from the accumulation of genetic and epigenetic alterations in breast epithelial cells. Despite remarkable progress in diagnosis and treatment, breast cancer continues to be the most prevalent cancer affecting women worldwide. Recent research has uncovered a compelling link between breast cancer onset and the extracellular environment enveloping tumor cells. The complex network of proteins secreted by cancer cells and other cellular components within the tumor microenvironment has emerged as a critical player in driving the disease's metastatic properties. Specifically, the proteins released by the tumor cells termed the secretome, can significantly influence the progression and metastasis of breast cancer. The breast cancer cell secretome promotes tumorigenesis through its ability to modulate growth-associated signaling pathways, reshaping the tumor microenvironment, supporting pre-metastatic niche formation, and facilitating immunosurveillance evasion. Additionally, the secretome has been shown to play a crucial role in drug resistance development, making it an attractive target for cancer therapy. Understanding the intricate role of the cancer cell secretome in breast cancer progression will provide new insights into the underlying mechanisms of this disease and aid in the development of more innovative therapeutic interventions. Hence, this review provides a nuanced analysis of the impact of the cancer cell secretome on breast cancer progression, elucidates the complex reciprocal interaction with the components of the tumor microenvironment and highlights emerging therapeutic opportunities for targeting the constituents of the secretome.

Long-Term Treatment with Gadopentetic Acid or Gadodiamide Increases TRPC5 Expression and Decreases Adriamycin Nuclear Accumulation in Breast Cancer Cells

Gadopentetic acid and gadodiamide are paramagnetic gadolinium-based contrast agents (GBCAs) that are routinely used for dynamic contrast-enhanced magnetic resonance imaging (MRI) to monitor disease progression in cancer patients. However, growing evidence indicates that repeated administration of GBCAs may lead to gadolinium (III) cation accumulation in the cortical bone tissue, skin, basal ganglia, and cerebellum, potentially leading to a subsequent slow long-term discharge of Gd3+. Gd3+ is a known activator of the TRPC5 channel that is implicated in breast cancer's resistance to chemotherapy. Herein, we found that gadopentetic acid (Gd-DTPA, 1 mM) potentiated the inward and outward currents through TRPC5 channels, which were exogenously expressed in HEK293 cells. Gd-DTPA (1 mM) also activated the Gd3+-sensitive R593A mutant of TRPC5, which exhibits a reduced sensitivity to GPCR-Gq/11-PLC dependent gating. Conversely, Gd-DTPA had no effect on TRPC5-E543Q, a Gd3+ insensitive TRPC5 mutant. Long-term treatment (28 days) of human breast cancer cells (MCF-7 and SK-BR-3) and adriamycin-resistant MCF-7 cells (MCF-7/ADM) with Gd-DTPA (1 mM) or gadodiamide (GDD, 1 mM) did not affect the IC50 values of ADM. However, treatment with Gd-DTPA or GDD significantly increased TRPC5 expression and decreased the accumulation of ADM in the nuclei of MCF-7 and SK-BR-3 cells, promoting the survival of these two breast cancer cells in the presence of ADM. The antagonist of TRPC5, AC1903 (1 μM), increased ADM nuclear accumulation induced by Gd-DTPA-treatment. These data indicate that prolonged GBCA treatment may lead to increased breast cancer cell survival owing to the upregulation of TRPC5 expression and the increased ADM resistance. We propose that while focusing on providing medical care of the best personalized quality in the clinic, excessive administration of GBCAs should be avoided in patients with metastatic breast cancer to reduce the risk of promoting breast cancer cell drug resistance.

The role of extracellular vesicles in cancer

Intercellular communication is a key feature of cancer progression and metastasis. Extracellular vesicles (EVs) are generated by all cells, including cancer cells, and recent studies have identified EVs as key mediators of cell-cell communication via packaging and transfer of bioactive constituents to impact the biology and function of cancer cells and cells of the tumor microenvironment. Here, we review recent advances in understanding the functional contribution of EVs to cancer progression and metastasis, as cancer biomarkers, and the development of cancer therapeutics.

Extracellular Vesicles in Breast Cancer: From Biology and Function to Clinical Diagnosis and Therapeutic Management

Breast cancer (BC) is the first worldwide most frequent cancer in both sexes and the most commonly diagnosed in females. Although BC mortality has been thoroughly declining over the past decades, there are still considerable differences between women diagnosed with early BC and when metastatic BC is diagnosed. BC treatment choice is widely dependent on precise histological and molecular characterization. However, recurrence or distant metastasis still occurs even with the most recent efficient therapies. Thus, a better understanding of the different factors underlying tumor escape is mainly mandatory. Among the leading candidates is the continuous interplay between tumor cells and their microenvironment, where extracellular vesicles play a significant role. Among extracellular vesicles, smaller ones, also called exosomes, can carry biomolecules, such as lipids, proteins, and nucleic acids, and generate signal transmission through an intercellular transfer of their content. This mechanism allows tumor cells to recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. By reciprocity, stromal cells can also use exosomes to profoundly modify tumor cell behavior. This review intends to cover the most recent literature on the role of extracellular vesicle production in normal and cancerous breast tissues. Specific attention is paid to the use of extracellular vesicles for early BC diagnosis, follow-up, and prognosis because exosomes are actually under the spotlight of researchers as a high-potential source of liquid biopsies. Extracellular vesicles in BC treatment as new targets for therapy or efficient nanovectors to drive drug delivery are also summarized.

Heat shock protein A2 is a novel extracellular vesicle-associated protein

70-kDa Heat Shock Proteins (HSPA/HSP70) are chaperones playing a central role in the proteostasis control mechanisms. Their basal expression can be highly elevated as an adaptive response to environmental and pathophysiological stress conditions. HSPA2, one of poorly characterised chaperones of the HSPA/HSP70 family, has recently emerged as epithelial cells differentiation-related factor. It is also commonly expressed in cancer cells, where its functional significance remains unclear. Previously, we have found that proteotoxic stress provokes a decrease in HSPA2 levels in cancer cells. In the present study we found that proteasome inhibition-related loss of HSPA2 from cancer cells neither is related to a block in the gene transcription nor does it relate to increased autophagy-mediated disposals of the protein. Proteotoxic stress stimulated extracellular release of HSPA2 in extracellular vesicles (EVs). Interestingly, EVs containing HSPA2 are also released by non-stressed cancer and normal cells. In human urinary EVs levels of HSPA2 were correlated with the levels of TSG101, one of the main EVs markers. We conclude that HSPA2 may constitute basic components of EVs. Nevertheless, its specific role in EVs and cell-to-cell communication requires further investigation.

Exosomes and osteosarcoma drug resistance

Osteosarcoma (OS) is a primary malignant tumor of bone characterized by the formation of bone tissue or immature bone by tumor cells. Because of its multi-drug resistance, even with the improvement of chemotherapy and the use of targeted drugs, the survival rate of osteosarcoma (OS) is still less than 60%, and it is easy to metastasize, which is a difficulty for many clinicians and researchers. In recent years, with the continuous research on exosomes, it has been found that exosomes play a role in the diagnosis, treatment and chemotherapy resistance of osteosarcoma due to their unique properties. Exosomes can reduce the intracellular accumulation of chemotherapeutic drugs by mediating drug efflux, thus inducing chemotherapeutic resistance in OS cells. Exosomal goods (including miRNA and functional proteins) carried by exosomes also show great potential in affecting the drug resistance of OS. In addition, miRNA carried by exosomes and exosomes exist widely in tumor cells and can reflect the characteristics of parent cells, so it can also be used as a biomarker of OS. At the same time, the development of nanomedicine has given a new hope for the treatment of OS. Exosomes are regarded as good natural nano-carriers by researchers because of their excellent targeted transport capacity and low toxicity, which will play an important role in the field of OS therapy in the future. This paper reviews the internal relationship between exosomes and OS chemotherapy resistance, discusses the broad prospects of exosomes in the field of diagnosis and treatment of OS, and puts forward some suggestions for the study of the mechanism of OS chemotherapy resistance.

Recent advances of small extracellular vesicle biomarkers in breast cancer diagnosis and prognosis

Current clinical tools for breast cancer (BC) diagnosis are insufficient but liquid biopsy of different bodily fluids has recently emerged as a minimally invasive strategy that provides a real-time snapshot of tumour biomarkers for early diagnosis, active surveillance of progression, and post-treatment recurrence. Extracellular vesicles (EVs) are nano-sized membranous structures 50-1000 nm in diameter that are released by cells into biological fluids. EVs contain proteins, nucleic acids, and lipids which play pivotal roles in tumourigenesis and metastasis through cell-to-cell communication. Proteins and miRNAs from small EVs (sEV), which range in size from 50-150 nm, are being investigated as a potential source for novel BC biomarkers using mass spectrometry-based proteomics and next-generation sequencing. This review covers recent developments in sEV isolation and single sEV analysis technologies and summarises the sEV protein and miRNA biomarkers identified for BC diagnosis, prognosis, and chemoresistance. The limitations of current sEV biomarker research are discussed along with future perspective applications.

Extracellular Vesicles as Drug Targets and Delivery Vehicles for Cancer Therapy

Extracellular vesicles (EVs) are particles that are released from cells into the extracellular space both under pathological and normal conditions. It is now well established that cancer cells secrete more EVs compared to non-cancerous cells and that, captivatingly, several proteins that are involved in EV biogenesis and secretion are upregulated in various tumours. Recent studies have revealed that EVs facilitate the interaction between cancer cells and their microenvironment and play a substantial role in the growth of tumours. As EVs are involved in several aspects of cancer progression including angiogenesis, organotropism, pre-metastatic niche formation, fostering of metastasis, and chemoresistance, inhibiting the release of EVs from cancer and the surrounding tumour microenvironment cells has been proposed as an ideal strategy to treat cancer and associated paraneoplastic syndromes. Lately, EVs have shown immense benefits in preclinical settings as a novel drug delivery vehicle. This review provides a brief overview of the role of EVs in various hallmarks of cancer, focusing on (i) strategies to treat cancer by therapeutically targeting the release of tumour-derived EVs and (ii) EVs as valuable drug delivery vehicles. Furthermore, we also outline the drawbacks of the existing anti-cancer treatments and the future prospective of EV-based therapeutics.

Tumor-Derived Small Extracellular Vesicles Involved in Breast Cancer Progression and Drug Resistance

Breast cancer is one of the most serious and terrifying threats to the health of women. Recent studies have demonstrated that interaction among cancer cells themselves and those with other cells, including immune cells, in a tumor microenvironment potentially and intrinsically regulate and determine cancer progression and metastasis. Small extracellular vesicles (sEVs), a type of lipid-bilayer particles derived from cells, with a size of less than 200 nm, are recognized as one form of important mediators in cell-to-cell communication. sEVs can transport a variety of bioactive substances, including proteins, RNAs, and lipids. Accumulating evidence has revealed that sEVs play a crucial role in cancer development and progression, with a significant impact on proliferation, invasion, and metastasis. In addition, sEVs systematically coordinate physiological and pathological processes, such as coagulation, vascular leakage, and stromal cell reprogramming, to bring about premetastatic niche formation and to determine metastatic organ tropism. There are a variety of oncogenic factors in tumor-derived sEVs that mediate cellular communication between local stromal cells and distal microenvironment, both of which are important in cancer progression and metastasis. Tumor-derived sEVs contain substances that are similar to parental tumor cells, and as such, sEVs could be biomarkers in cancer progression and potential therapeutic targets, particularly for predicting and preventing future metastatic development. Here, we review the mechanisms underlying the regulation by tumor-derived sEVs on cancer development and progression, including proliferation, metastasis, drug resistance, and immunosuppression, which coordinately shape the pro-metastatic microenvironment. In addition, we describe the application of sEVs to the development of cancer biomarkers and potential therapeutic modalities and discuss how they can be engineered and translated into clinical practice.

Extracellular Vesicles in Cancer Drug Resistance: Roles, Mechanisms, and Implications

Extracellular vesicles (EVs) are cell-derived nanosized vesicles that mediate cell-to-cell communication via transporting bioactive molecules and thus are critically involved in various physiological and pathological conditions. EVs contribute to different aspects of cancer progression, such as cancer growth, angiogenesis, metastasis, immune evasion, and drug resistance. EVs induce the resistance of cancer cells to chemotherapy, radiotherapy, targeted therapy, antiangiogenesis therapy, and immunotherapy by transferring specific cargos that affect drug efflux and regulate signaling pathways associated with epithelial-mesenchymal transition, autophagy, metabolism, and cancer stemness. In addition, EVs modulate the reciprocal interaction between cancer cells and noncancer cells in the tumor microenvironment (TME) to develop therapy resistance. EVs are detectable in many biofluids of cancer patients, and thus are regarded as novel biomarkers for monitoring therapy response and predicting prognosis. Moreover, EVs are suggested as promising targets and engineered as nanovehicles to deliver drugs for overcoming drug resistance in cancer therapy. In this review, the biological roles of EVs and their mechanisms of action in cancer drug resistance are summarized. The preclinical studies on using EVs in monitoring and overcoming cancer drug resistance are also discussed.

Exosome biogenesis: machinery, regulation, and therapeutic implications in cancer

Exosomes are well-known key mediators of intercellular communication and contribute to various physiological and pathological processes. Their biogenesis involves four key steps, including cargo sorting, MVB formation and maturation, transport of MVBs, and MVB fusion with the plasma membrane. Each process is modulated through the competition or coordination of multiple mechanisms, whereby diverse repertoires of molecular cargos are sorted into distinct subpopulations of exosomes, resulting in the high heterogeneity of exosomes. Intriguingly, cancer cells exploit various strategies, such as aberrant gene expression, posttranslational modifications, and altered signaling pathways, to regulate the biogenesis, composition, and eventually functions of exosomes to promote cancer progression. Therefore, exosome biogenesis-targeted therapy is being actively explored. In this review, we systematically summarize recent progress in understanding the machinery of exosome biogenesis and how it is regulated in the context of cancer. In particular, we highlight pharmacological targeting of exosome biogenesis as a promising cancer therapeutic strategy.

Extracellular vesicles in cancer therapy

Extracellular vesicles (EVs), including a variety of membrane-enclosed nanosized particles carrying cell-derived cargo, mediate a major type of intercellular communication in physiological and pathological processes. Both cancer and non-cancer cells secrete EVs, which can travel to and influence various types of cells at the primary tumor site as well as in distant organs. Tumor-derived EVs contribute to cancer cell plasticity and resistance to therapy, adaptation of tumor microenvironment, local and systemic vascular remodeling, immunomodulation, and establishment of pre-metastatic niches. Therefore, targeting the production, uptake, and function of tumor-derived EVs has emerged as a new strategy for stand-alone or combinational therapy of cancer. On the other hand, as EV cargo partially reflects the genetic makeup and phenotypic properties of the secreting cell, EV-based biomarkers that can be detected in biofluids are being developed for cancer diagnosis and for predicting and monitoring tumor response to therapy. Meanwhile, EVs from presumably safe sources are being developed as delivery vehicles for anticancer therapeutic agents and as anticancer vaccines. Numerous reviews have discussed the biogenesis and characteristics of EVs and their functions in cancer. Here, I highlight recent advancements in translation of EV research outcome towards improved care of cancer, including developments of non-invasive EV-based biomarkers and therapeutic agents targeting tumor-derived EVs as well as engineering of therapeutic EVs.

The interplay between physical cues and mechanosensitive ion channels in cancer metastasis

Physical cues have emerged as critical influencers of cell function during physiological processes, like development and organogenesis, and throughout pathological abnormalities, including cancer progression and fibrosis. While ion channels have been implicated in maintaining cellular homeostasis, their cell surface localization often places them among the first few molecules to sense external cues. Mechanosensitive ion channels (MICs) are especially important transducers of physical stimuli into biochemical signals. In this review, we describe how physical cues in the tumor microenvironment are sensed by MICs and contribute to cancer metastasis. First, we highlight mechanical perturbations, by both solid and fluid surroundings typically found in the tumor microenvironment and during critical stages of cancer cell dissemination from the primary tumor. Next, we describe how Piezo1/2 and transient receptor potential (TRP) channels respond to these physical cues to regulate cancer cell behavior during different stages of metastasis. We conclude by proposing alternative mechanisms of MIC activation that work in tandem with cytoskeletal components and other ion channels to bestow cells with the capacity to sense, respond and navigate through the surrounding microenvironment. Collectively, this review provides a perspective for devising treatment strategies against cancer by targeting MICs that sense aberrant physical characteristics during metastasis, the most lethal aspect of cancer.

Exosome application in treatment and diagnosis of B-cell disorders: leukemias, multiple sclerosis, and arthritis rheumatoid

Exosomes, known as a type of extracellular vesicles (EVs), are lipid particles comprising heterogeneous contents such as nucleic acids, proteins, and DNA. These bi-layered particles are naturally released into the extracellular periphery by a variety of cells such as neoplastic cells. Given that exosomes have unique properties, they can be used as vectors and carriers of biological and medicinal particles like drugs for delivering to the desired areas. The proteins and RNAs being encompassed by the circulating exosomes in B-cell malignancies are deemed as the promising sources for diagnostic and prognostic biomarkers, as well as therapeutic agents. Exosomes can also provide a "snapshot" view of the tumor and metastatic landscape at any particular time. Further, clinical research has shown that exosomes are produced by immune cells such as dendritic cells can stimulate the immune system, so these exosomes can be used in antitumor vaccines. Despite the great potential of exosomes in the fields of diagnostic and treatment, further studies are in need for these purposes to reach a convergence notion. This review highlights the applications of exosomes in multiple immune-related diseases, including chronic lymphocytic leukemia, multiple sclerosis, and arthritis rheumatoid, as well as explaining sundry aspects of exosome therapy and the function of exosomes in diagnosing diseases.

Roles of calcium signaling in cancer metastasis to bone

Bone metastasis is a frequent complication for cancers and an important reason for the mortality in cancer patients. After surviving in bone, cancer cells can cause severe pain, life-threatening hypercalcemia, pathologic fractures, spinal cord compression, and even death. However, the underlying mechanisms of bone metastasis were not clear. The role of calcium (Ca2+) in cancer cell proliferation, migration, and invasion has been well established. Interestingly, emerging evidence indicates that Ca2+ signaling played a key role in bone metastasis, for it not only promotes cancer progression but also mediates osteoclasts and osteoblasts differentiation. Therefore, Ca2+ signaling has emerged as a novel therapeutical target for cancer bone metastasis treatments. Here, the role of Ca2+ channels and Ca2+-binding proteins including calmodulin and Ca2+-sensing receptor in bone metastasis, and the perspective of anti-cancer bone metastasis therapeutics via targeting the Ca2+ signaling pathway are summarized.

Comparative analysis of transient receptor potential channel 5 opposite strand-induced gene expression patterns and protein-protein interactions in triple-negative breast cancer

In patients with triple-negative breast cancer (TNBC), high tumour mutation burden and aberrant oncogene expression profiles are some of the causes of poor prognosis. Therefore, it is necessary to identify aberrantly expressed oncogenes, since they have the potential to serve as therapeutic targets. Transient receptor potential channel 5 opposite strand (TRPC5OS) has been previously shown to function as a novel tumour inducer. However, the underlying mechanism of TRPC5OS function in TNBC remain to be elucidated. Therefore, in the present study TRPC5OS expression was first measured in tissue samples of patients with TNBC and a panel of breast cancer cell lines (ZR-75-1, MDA-MB-453, SK-BR-3, JIMT-1, BT474 and HCC1937) by using qRT-PCR and Western blotting. Subsequently, the possible effects of TRPC5OS on MDA-MB-231 cells proliferation were determined using Cell Counting Kit-8 and 5-Ethynyl-2′-deoxyuridine assays after Lentiviral transfection of MDA-MB-231. In addition, potential interaction partners of TRPC5OS were explored using liquid chromatography-mass spectrometry (LC-MS)/MS. Gene expression patterns following TRPC5OS overexpression were also detected in MDA-MB-231 cells by using High-throughput sequencing. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analysis were then used to systematically verify the potential interactions among the TRPC5OS-regulated genes. The potential relationship between TRPC5OS-interacting proteins and gene expression patterns were studied using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analysis. TRPC5OS expression was found to be significantly higher in TNBC tumour tissues and breast cancer cell lines compared with luminal tumour tissues and ZR-75-1. In addition, the overexpression of TRPC5OS significantly increased cell proliferation. High-throughput sequencing results revealed that 5,256 genes exhibited differential expression following TRPC5OS overexpression, including 3,269 upregulated genes and 1,987 downregulated genes. GO analysis results indicated that the functions of these differentially expressed genes were enriched in the categories of ‘cell division’ and ‘cell proliferation’ regulation. KEGG analysis showed that the TRPC5OS-regulated genes were associated with processes of ‘homologous recombination’ and ‘TNF signalling pathways’. Subsequently, 17 TRPC5OS-interacting proteins were found using LC-MS/MS and STRING analysis. The most important protein among interacting proteins was ENO1 which was associated with glycolysis and regulated proliferation of cancer. In summary, data from the present study suggest that TRPC5OS overexpression can increase TNBC cell proliferation and ENO1 may be a potential target protein mediated by TRPC5OS. Therefore, TRPC5OS may serve as a novel therapeutic target for TNBC.

Extracellular vesicles as natural therapeutic agents and innate drug delivery systems for cancer treatment: Recent advances, current obstacles, and challenges for clinical translation

As cancer poses a significant threat to the well-being of humans on a global scale, many researchers have embarked on the search for effective anticancer therapeutic agents. In recent years, many drugs have been shown to have extraordinary anticancer effects. However, in a lot of cases the treatment is accompanied by undesirable side effects due to some intrinsic properties linked to the therapeutic agents, such as poor targeting selectivity and short half-life in the circulation. In this regard, extracellular vesicles (EVs), a diverse family of natural cell-derived vesicles, steal the show as potential anticancer immunotherapy or delivery vectors of anticancer agents since they are an innate mechanism of intercellular communication. Here, we describe some of the most hotly-debated issues regarding the use of EVs as anticancer therapeutics. First, we review the biology of EVs providing the most up-to-date definition of EVs as well as highlighting their circulation kinetics and homing properties. Next, we share our views on popular methods reported for EV isolation, characterization, and functional analysis. Pioneering and innovative reports along with emerging challenges in the field of EV imaging and EV drug loading strategies are then discussed. Finally, we examine in detail the therapeutic application of EVs in cancer treatment, including their role in cancer immunotherapy and as natural delivery systems for anticancer agents including natural compounds such as paclitaxel and doxorubicin. We consider standardised protocols and proper analytical approaches to be crucial in improving the reproducibility and rigor in EV research and ensuring the successful translation of EVs as anticancer therapeutics.

The role of extracellular vesicles in the transfer of drug resistance competences to cancer cells

Drug resistance remains a major hurdle to successful cancer treatment, being accountable for approximately 90% of cancer-related deaths. In the past years, increasing attention has been given to the role of extracellular vesicles (EVs) in the horizontal transfer of drug resistance in cancer. Indeed, many studies have described the dissemination of therapy resistance traits mediated by EVs, which may be transferred from drug resistant tumor cells to their drug sensitive counterparts. Importantly, different key players of drug resistance have been identified in the cargo of those EVs, such as drug efflux pumps, oncoproteins, antiapoptotic proteins, or microRNAs, among others. Interestingly, the EVs-mediated crosstalk between cells from the tumor microenvironment (TME) and tumor cells has emerged as another important mechanism that leads to cancer cells drug resistance. Recently, the cargo of the TME-derived EVs responsible for the transfer of drug resistance traits has also become a focus of attention. In addition, the possible mechanisms involved in drug sequestration by EVs, likely to contribute to cancer drug resistance, are also described and discussed herein. Despite the latest scientific advances in the field of EVs, this is still a challenging area of research, particularly in the clinical setting. Therefore, further investigation is needed to assess the relevance of EVs to the failure of cancer patients to drug treatment, to identify biomarkers of drug resistance in the EV's cargo, and to develop effective therapeutic strategies to surmount drug resistance. This up-to-date review summarizes relevant literature on the role of EVs in the transfer of drug resistance competences to cancer cells, and the relevance of tumor cells and of TME cells in this process. Finally, this knowledge is integrated with a discussion of possible future clinical applications of EVs as biomarkers of drug resistance.

Extracellular Vesicles and Cell Pathways Involved in Cancer Chemoresistance

Chemoresistance is a pharmacological condition that allows transformed cells to maintain their proliferative phenotype in the presence of administered anticancer drugs. Recently, extracellular vesicles, including exosomes, have been identified as additional players responsible for the chemoresistance of cancer cells. These are nanovesicles that are released by almost all cell types in both physiological and pathological conditions and contain proteins and nucleic acids as molecular cargo. Extracellular vesicles released in the bloodstream reach recipient cells and confer them novel metabolic properties. Exosomes can foster chemoresistance by promoting prosurvival and antiapoptotic pathways, affecting cancer stem cells and immunotherapies, and stimulating drug efflux. In this context, a crucial role is played by membrane transporters belonging to ABC, SLC, and P-type pump families. These proteins are fundamental in cell metabolism and drug transport in either physiological or pathological conditions. In this review, different roles of extracellular vesicles in drug resistance of cancer cells will be explored.

Biomedical application of small extracellular vesicles in cancer treatment

Extracellular vesicles (EVs) are produced by almost all cell types in vivo or in vitro. Among them, exosomes are small nanovesicles with a lipid bilayer, proteins and RNAs actively involved in cellular communication, suggesting that they may be used both as biomarkers and for therapeutic purposes in diseases such as cancer. Moreover, the idea of using them as drug delivery vehicle arises as a promising field of study. Here, we reviewed recent findings showing the importance of EVs, with special focus in exosomes as biomarkers including the most relevant proteins found in different cancer types and it is discussed the FDA approved tests which use exosomes in clinical practice. Finally, we present an overview of the different chimeric EVs developed in the last few years, demonstrating that they can be conjugate to nanoparticles, biomolecules, cancer drugs, etc., and can be developed for a specific cancer treatment. Additionally, we summarized the clinical trials where EVs are used in the treatment of several cancer types aiming to improve the prognosis of these deadly diseases.

Calcium Signalling in Breast Cancer Associated Bone Pain

Calcium (Ca²⁺) is involved as a signalling mediator in a broad variety of physiological processes. Some of the fastest responses in human body like neuronal action potential firing, to the slowest gene transcriptional regulation processes are controlled by pathways involving calcium signalling. Under pathological conditions these mechanisms are also involved in tumoral cells reprogramming, resulting in the altered expression of genes associated with cell proliferation, metastatisation and homing to the secondary metastatic site. On the other hand, calcium exerts a central function in nociception, from cues sensing in distal neurons, to signal modulation and interpretation in the central nervous system leading, in pathological conditions, to hyperalgesia, allodynia and pain chronicization. It is well known the relationship between cancer and pain when tumoral metastatic cells settle in the bones, especially in late breast cancer stage, where they alter the bone micro-environment leading to bone lesions and resulting in pain refractory to the conventional analgesic therapies. The purpose of this review is to address the Ca²⁺ signalling mechanisms involved in cancer cell metastatisation as well as the function of the same signalling tools in pain regulation and transmission. Finally, the possible interactions between these two cells types cohabiting the same Ca²⁺ rich environment will be further explored attempting to highlight new possible therapeutical targets.

The Role of Exosomal Non-Coding RNAs in Colorectal Cancer Drug Resistance

BACKGROUND

Colorectal cancer (CRC) is one of the most common types of cancer diagnosed worldwide with high morbidity; drug resistance is often responsible for treatment failure in CRC. Non-coding RNAs (ncRNAs) play distinct regulatory roles in tumorigenesis, cancer progression and chemoresistance.

METHODS

A literature search was conducted in PubMed database in order to sum up and discuss the role of exosomal ncRNAs (ex-ncRNAs) in CRC drug resistance/response and their possible mechanisms.

RESULTS

Thirty-six (36) original research articles were identified; these included exosome or extracellular vesicle (EV)-containing microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and small-interfering (siRNAs). No studies were found for piwi-interacting RNAs.

CONCLUSIONS

Exosomal transfer of ncRNAs has been documented as a new mechanism of CRC drug resistance. Despite being in its infancy, it has emerged as a promising field for research in order to (i) discover novel biomarkers for therapy monitoring and/or (ii) reverse drug desensitization.

Tumor-Derived Extracellular Vesicles Regulate Cancer Progression in the Tumor Microenvironment

Extracellular vesicles (EVs) are nanosized particles released by numerous kinds of cells, which are now increasingly considered as essential vehicles of cell-to-cell communication and biomarkers in disease diagnosis and treatment. They contain a variety of biomolecular components, including lipids, proteins and nucleic acids. These functional molecules can be transmitted between tumor cells and other stromal cells such as endothelial cells, fibroblasts and immune cells utilizing EVs. As a result, tumor-derived EVs can deliver molecules to remodel the tumor microenvironment, thereby influencing cancer progression. On the one hand, tumor-derived EVs reprogram functions of endothelial cells, promote cancer-associated fibroblasts transformation, induce resistance to therapy and inhibit the immune response to form a pro-tumorigenic environment. On the other hand, tumor-derived EVs stimulate the immune response to create an anti-tumoral environment. This article focuses on presenting a comprehensive and critical overview of the potential role of tumor-derived EVs-mediated communication in the tumor microenvironment.

Diagnosis and treatment monitoring in breast cancer: how liquid biopsy can support patient management

Imaging and tissue biopsies represent the current gold standard for breast cancer diagnosis and patient management. However, these practices are time-consuming, expensive and require invasive procedures. Moreover, tissue biopsies do not capture spatial and temporal tumor heterogeneity. Conversely, liquid biopsy, which includes circulating tumor cells, circulating free nucleic acids and extracellular vesicles, is minimally invasive, easy to perform and can be repeated during a patient's follow-up. Increasing evidence also suggests that liquid biopsy can be used to efficiently screen and diagnose tumors at an early stage, and to monitor changes in the tumor molecular profile. In the present review, clinical applications and prospects are discussed.

The Advancing Roles of Exosomes in Breast Cancer

Breast cancer (BC) develops from breast tissue and is the most common aggressive malignant tumor in women worldwide. Although advanced treatment strategies have been applied and reduced current mortality rates, BC control remains unsatisfactory. It is essential to elucidate the underlying molecular mechanisms to assist clinical options. Exosomes are a type of extracellular vesicles and mediate cellular communications by delivering various biomolecules (oncogenes, oncomiRs, proteins, and even pharmacological compounds). These bioactive molecules can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. Extensive studies have implicated exosomes in BC biology, including therapeutic resistance and the surrounding microenvironment. This review focuses on discussing the functions of exosomes in tumor treatment resistance, invasion and metastasis of BC. Moreover, we will also summarize multiple interactions between exosomes and the BC tumor microenvironment. Finally, we propose promising clinical applications of exosomes in BC.

Targeting Ca2+ signaling: A new arsenal against cancer

The drug resistance of cancer cells is a major concern in medical oncology, resulting in the failure of chemotherapy. Ca²⁺ plays a pivotal role in inducing multidrug resistance in cancer cells. Calcium signaling is a critical regulator of many cancer hallmarks, such as angiogenesis, invasiveness, and migration. In this review, we describe the involvement of Ca²⁺ signaling and associated proteins in cancer progression and in the development of multidrug resistance in cancer cells. We also highlight the possibilities and challenges of targeting the Ca²⁺ channels, transporters, and pumps involved in Ca²⁺ signaling in cancer cells through structure-based drug design. This work will open a new therapeutic window to be used against cancer in upcoming years.