Isolation and Identification of Long Non-Coding RNAs in Exosomes Derived from the Serum of Colorectal Carcinoma Patients

The therapeutic effects of exosomes the first time isolated from pancreatic islet-derived progenitor cells in the treatment of pancreatic cancer

Insulinoma is an excessive insulin-released beta cell tumor. Pancreas cancer is one of the deadliest malignant neoplasms. Exosomes are secreted cell membrane vesicles containing a large number of proteins, lipids, and nucleic acids. The aim of this study is to investigate the effects of exosomes on two cell lines of benign and malignant character. For the first time, exosomes were isolated from pancreatic island-derived progenitor cells (PID-PCs) and applied to INS-1 and MiaPaCa-2 cells. In addition, exosomes isolated from PID-PC, MiaPaca-2, and INS-1 cells were characterized in order to compare their sizes with other previously isolated exosomes. Alix, TSG101, CD9, and CD81 were analyzed. The size and concentration of exosomes and the cell viability were detected. The cells were marked with HSP90, HSF-1, Kaspaz-8, Active-Kaspaz-3, Beclin, and p-Bcl-2. The cell cytotoxicity and insulin levels kit were measured. Alix in all exosomes, and PID-PC, MiaPaca-2 cell lysates; TSG101 in PID-PC and MiaPaca-2 cell lysates; CD9 in INS-1 exosomes were detected. The dimensions of isolated exosomes were 103.6 ± 28.6 nm, 100.7 ± 10 nm, and 147.2 ± 12.3 nm for PID-PCs, MiaPaca-2, and INS-1 cells. The cell viability decreased and HSP90 increased in the MiaPaca-2 cells. The HSF-1 was higher in the control MiaPaca-2 cell compared to the control INS-1 cell, and the exosome-treated MiaPaca-2 cell compared to the exosome-treated INS-1 cell. Beclin and p-Bcl-2 were decreased in the exosome-treated MiaPaca-2 cells. The insulin level in the cell lysates increased compared to cell secretion in INS-1 cells. In conclusion, exosomes isolated from the PID-PC caused cell death in the MiaPaca-2 cells in a time- and dose-dependent manner. The IC50 value determined for MiaPaca-2 cells has no effect on cell viability in INS-1 cells, which best mimics pancreatic beta cells and can be used instead of healthy pancreatic beta cells. Isolated exosomes can kill cancer cells without damaging healthy cells.

Optimized procedure for high-throughput transcriptome profiling of small extracellular vesicles isolated from low volume serum samples

OBJECTIVES

Small extracellular vesicles (EVs) contain various signaling molecules, thus playing a crucial role in cell-to-cell communication and emerging as a promising source of biomarkers. However, the lack of standardized procedures impedes their translation to clinical practice. Thus, we compared different approaches for high-throughput analysis of small EVs transcriptome.

METHODS

Small EVs were isolated from 150 μL of serum. Quality and quantity were assessed by dynamic light scattering, transmission electron microscopy, and Western blot. Comparison of RNA extraction efficiency was performed, and expression of selected genes was analyzed by RT-qPCR. Whole transcriptome analysis was done using microarrays.

RESULTS

Obtained data confirmed the suitability of size exclusion chromatography for isolation of small EVs. Analyses of gene expression showed the best results in case of samples isolated by Monarch Total RNA Miniprep Kit. Totally, 7,182 transcripts were identified to be deregulated between colorectal cancer patients and healthy controls. The majority of them were non-coding RNAs with more than 70 % being lncRNAs, while protein-coding genes represented the second most common gene biotype.

CONCLUSIONS

We have optimized the protocol for isolation of small EVs and their RNA from low volume of sera and confirmed the suitability of Clariom D Pico Assays for transcriptome profiling.

Exosomal lncRNAs in gastrointestinal cancer

Gastrointestinal cancer (GIC) remains a leading cause of morbidity and mortality worldwide. Unfortunately, these cancers are diagnosed in advanced metastatic stages due to lack of reliable biomarkers that are sufficiently specific and sensitive in early disease. There has been growing evidence that circulating exosomes can be used to diagnose cancer non-invasively with limited risks and side effects. Furthermore, exosomal long non-coding RNAs (lncRNAs) are emerging as a new class of promising biomarkers in cancer. This review provides an overview of the extraction and detection of exosomal lncRNAs with a focus on their potential role in GIC.

Exosomal long non-coding RNAs: novel molecules in gastrointestinal cancers' progression and diagnosis

Gastrointestinal (GI) cancers arise in the GI tract and accessory organs, including the mouth, esophagus, stomach, liver, biliary tract, pancreas, small intestine, large intestine, and rectum. GI cancers are a major cause of cancer-related morbidity and mortality worldwide. Exosomes act as mediators of cell-to-cell communication, with pleiotropic activity in the regulation of homeostasis, and can be markers for diseases. Non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs), can be transported by exosomes derived from tumor cells or non-tumor cells. They can be taken by recipient cells to alter their function or remodel the tumor microenvironment. Moreover, due to their uniquely low immunogenicity and excellent stability, exosomes can be used as natural carriers for therapeutic ncRNAs in vivo. Exosomal lncRNAs have a crucial role in regulating several cancer processes, including angiogenesis, proliferation, drug resistance, metastasis, and immunomodulation. Exosomal lncRNA levels frequently alter according to the onset and progression of cancer. Exosomal lncRNAs can therefore be employed as biomarkers for the diagnosis and prognosis of cancer. Exosomal lncRNAs can also monitor the patient's response to chemotherapy while also serving as potential targets for cancer treatment. Here, we discuss the role of exosomal lncRNAs in the biology and possible future treatment of GI cancer.

The systemic-level repercussions of cancer-associated inflammation mediators produced in the tumor microenvironment

The tumor microenvironment is a dynamic, complex, and redundant network of interactions between tumor, immune, and stromal cells. In this intricate environment, cells communicate through membrane-membrane, ligand-receptor, exosome, soluble factors, and transporter interactions that govern cell fate. These interactions activate the diverse and superfluous signaling pathways involved in tumor promotion and progression and induce subtle changes in the functional activity of infiltrating immune cells. The immune response participates as a selective pressure in tumor development. In the early stages of tumor development, the immune response exerts anti-tumor activity, whereas during the advanced stages, the tumor establishes mechanisms to evade the immune response, eliciting a chronic inflammation process that shows a pro-tumor effect. The deregulated inflammatory state, in addition to acting locally, also triggers systemic inflammation that has repercussions in various organs and tissues that are distant from the tumor site, causing the emergence of various symptoms designated as paraneoplastic syndromes, which compromise the response to treatment, quality of life, and survival of cancer patients. Considering the tumor-host relationship as an integral and dynamic biological system, the chronic inflammation generated by the tumor is a communication mechanism among tissues and organs that is primarily orchestrated through different signals, such as cytokines, chemokines, growth factors, and exosomes, to provide the tumor with energetic components that allow it to continue proliferating. In this review, we aim to provide a succinct overview of the involvement of cancer-related inflammation at the local and systemic level throughout tumor development and the emergence of some paraneoplastic syndromes and their main clinical manifestations. In addition, the involvement of these signals throughout tumor development will be discussed based on the physiological/biological activities of innate and adaptive immune cells. These cellular interactions require a metabolic reprogramming program for the full activation of the various cells; thus, these requirements and the by-products released into the microenvironment will be considered. In addition, the systemic impact of cancer-related proinflammatory cytokines on the liver-as a critical organ that produces the leading inflammatory markers described to date-will be summarized. Finally, the contribution of cancer-related inflammation to the development of two paraneoplastic syndromes, myelopoiesis and cachexia, will be discussed.

Long non-coding RNA LINC00152 in cancer: Roles, mechanisms, and chemotherapy and radiotherapy resistance

Long non-coding RNA LINC00152 (cytoskeleton regulator, or LINC00152) is an 828-bp lncRNA located on chromosome 2p11.2. LINC00152 was originally discovered during research on hepatocarcinogenesis and has since been regarded as a crucial oncogene that regulates gene expression in many cancer types. LINC00152 is aberrantly expressed in various cancers, including gastric, breast, ovarian, colorectal, hepatocellular, and lung cancer, and glioma. Several studies have indicated that LINC00152 is correlated with cell proliferation, apoptosis, migration, invasion, cell cycle, epithelial-mesenchymal transition (EMT), chemotherapy and radiotherapy resistance, and tumor growth and metastasis. High LINC00152 expression in most tumors is significantly associated with poor patient prognosis. Mechanistic analysis has demonstrated that LINC00152 can serve as a competing endogenous RNA (ceRNA) by sponging miRNA, regulating the abundance of the protein encoded by a particular gene, or modulating gene expression at the epigenetic level. LINC00152 can serve as a diagnostic or prognostic biomarker, as well as a therapeutic target for most cancer types. In the present review, we discuss the roles and mechanisms of LINC00152 in human cancer, focusing on its functions in chemotherapy and radiotherapy resistance.

Exosome-Mediated Response to Cancer Therapy: Modulation of Epigenetic Machinery

Exosomes, the extracellular vesicles produced in the endosomal compartments, facilitate the transportation of proteins as well as nucleic acids. Epigenetic modifications are now considered important for fine-tuning the response of cancer cells to various therapies, and the acquired resistance against targeted therapies often involves dysregulated epigenetic modifications. Depending on the constitution of their cargo, exosomes can affect several epigenetic events, thus impacting post-transcriptional regulations. Thus, a role of exosomes as facilitators of epigenetic modifications has come under increased scrutiny in recent years. Exosomes can deliver methyltransferases to recipient cells and, more importantly, non-coding RNAs, particularly microRNAs (miRNAs), represent an important exosome cargo that can affect the expression of several oncogenes and tumor suppressors, with a resulting impact on cancer therapy resistance. Exosomes often harbor other non-coding RNAs, such as long non-coding RNAs and circular RNAs that support resistance. The exosome-mediated transfer of all this cargo between cancer cells and their surrounding cells, especially tumor-associated macrophages and cancer-associated fibroblasts, has a profound effect on the sensitivity of cancer cells to several chemotherapeutics. This review focuses on the exosome-induced modulation of epigenetic events with resulting impact on sensitivity of cancer cells to various therapies, such as, tamoxifen, cisplatin, gemcitabine and tyrosine kinase inhibitors. A better understanding of the mechanisms by which exosomes can modulate response to therapy in cancer cells is critical for the development of novel therapeutic strategies to target cancer drug resistance.

Advances in the Application of Exosomes Identification Using Surface-Enhanced Raman Spectroscopy for the Early Detection of Cancers

Exosomes are small nanoscale vesicles with a double-layered lipid membrane structure secreted by cells, and almost all types of cells can secrete exosomes. Exosomes carry a variety of biologically active contents such as nucleic acids and proteins, and play an important role not only in intercellular information exchange and signal transduction, but also in various pathophysiological processes in the human body. Surface-enhanced Raman Spectroscopy (SERS) uses light to interact with nanostructured materials such as gold and silver to produce a strong surface plasmon resonance effect, which can significantly enhance the Raman signal of molecules adsorbed on the surface of nanostructures to obtain a rich fingerprint of the sample itself or Raman probe molecules with ultra-sensitivity. The unique advantages of SERS, such as non-invasive and high sensitivity, good selectivity, fast analysis speed, and low water interference, make it a promising technology for life science and clinical testing applications. In this paper, we briefly introduce exosomes and the current main detection methods. We also describe the basic principles of SERS and the progress of the application of unlabeled and labeled SERS in exosome detection. This paper also summarizes the value of SERS-based exosome assays for early tumor diagnosis.