The effects of ovarian cancer cell-derived exosomes on vascular endothelial growth factor expression in endothelial cells

Revolutionizing cancer therapy: nanoformulation of miRNA-34 - enhancing delivery and efficacy for various cancer immunotherapies: a review

Despite recent advancements in cancer therapies, challenges such as severe toxic effects, non-selective targeting, resistance to chemotherapy and radiotherapy, and recurrence of metastatic tumors persist. Consequently, there has been considerable effort to explore innovative anticancer compounds, particularly in immunotherapy, which offer the potential for enhanced biosafety and efficacy in cancer prevention and treatment. One such avenue of exploration involves the miRNA-34 (miR-34) family, known for its ability to inhibit tumorigenesis across various cancers. Dysregulation of miR-34 has been observed in several human cancers, and it is recognized as a tumor suppressor microRNA due to its synergistic interaction with the well-established tumor suppressor p53. However, challenges have arisen with the therapeutic application of miR-34a. These include its susceptibility to degradation by RNase in serum, limiting its ability to penetrate capillary endothelium and reach target cells, as well as reports of immunoreactive adverse reactions. Furthermore, unexpected side effects may occur, such as the accumulation of therapeutic miRNAs in healthy tissues due to interactions with serum proteins on nano-vector surfaces, nanoparticle breakdown in the bloodstream due to shearing stress, and unsuccessful extravasation of nanocarriers to target cells owing to interstitial fluid pressure. Despite these challenges, miR-34a remains a promising candidate for cancer therapy, and other members of the miR-34 family have also shown potential in inhibiting tumor cell proliferation. While the in vivo applications of miR-34b/c are limited, they warrant further exploration for oncotherapy. Recently, procedures utilizing nanoparticles have been developed to address the challenges associated with the clinical use of miR-34, demonstrating efficacy both in vitro and in vivo. This review highlights emerging trends in nanodelivery systems for miR-34 targeting cancer cells, offering insights into novel nanoformulations designed to enhance the anticancer therapeutic activity and targeting precision of miR-34. As far as current knowledge extends, no similar recent review comprehensively addresses the diverse nanoformulations aimed at optimizing the therapeutic potential of miR-34 in anticancer strategies.

Unraveling the extracellular vesicle network: insights into ovarian cancer metastasis and chemoresistance

Ovarian cancer (OC) is one of the most prevalent and lethal gynecological malignancies, with high mortality primarily due to its aggressive nature, frequent metastasis, and resistance to standard therapies. Recent research has highlighted the critical role of extracellular vesicles (EVs) in these processes. EVs, secreted by living organisms and carrying versatile and bioactive cargoes, play a vital role in intercellular communication. Functionally, the transfer of cargoes orchestrates multiple processes that actively affect not only the primary tumor but also local and distant pre-metastatic niche. Furthermore, their unique biological properties position EVs as novel therapeutic targets and promising drug delivery systems, with potential profound implications for cancer patients.This review summarizes recent progress in EV biology, delving into the intricate mechanisms by which EVs contribute to OC metastasis and drug resistance. It also explores the latest advances and therapeutic potential of EVs in the clinical context of OC. Despite the progress made, EV research in OC remains in its nascent stages. Consequently, this review presents existing research limitations and suggests avenues for future investigation. Altogether, the review aims to elucidate the critical roles of EVs in OC and spotlight their promising potential in this field.

The crosstalk between lung cancer cells and platelets promotes tumor angiogenesis in vivo and in vitro

PURPOSE

We previously showed that the crosstalk of H1975 cells and platelets (PLTs) may promote tumor angiogenesis. This study aimed to determine whether other lung cell lines (LC) interacting with PLTs could affect tumor angiogenesis through in vivo and in vitro experiments.

METHODS

Cell Counting Kit-8, EdU cell proliferation, wound healing, Transwell invasion, F-actin staining, tube formation, ELISA and western blot assays were performed to investigate the properties and the expression levels of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR2), p-VEGFR2, PI3K, p-PI3K, Akt, p-Akt and eNOS in supernatants or HUVECs. Then, using mouse models, immunohistochemistry was applied to detect the expression levels of CD31 and VEGF.

RESULTS

Compared with single-cultured HUVECs (EC) or incubation with either LC supernatant (EC + LC) or activated PLT supernatant (EC + PLT), incubation with SN_LCP (supernatant derived from LC cocultured with PLT, named the EC + LC + PLT group) improved the viability, proliferation, migration, invasion, and tube formation activities of HUVECs and the expression of F-actin, VEGF, VEGFR2, p-VEGFR2, p-PI3K, p-Akt and eNOS in HUVECs. Higher expression levels of CD31 and VEGF were found in the LLC + PLT (mouse model inoculated with Lewis lung cancer (LLC) cells cocultured with PLTs) group than in the LLC (mouse model inoculated with LLC cells alone) group. However, the increased angiogenic properties of HUVECs were inhibited by apatinib, an inhibitor of VEGFR2.

CONCLUSION

Lung carcinoma cells interacting with PLTs may play a key role in lung carcinoma angiogenesis through the VEGF/VEGFR2 signaling pathway.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Mesothelial-to-Mesenchymal Transition and Exosomes in Peritoneal Metastasis of Ovarian Cancer

Most patients with ovarian cancer (OvCA) present peritoneal disseminated disease at the time of diagnosis. During peritoneal metastasis, cancer cells detach from the primary tumor and disseminate through the intraperitoneal fluid. The peritoneal mesothelial cell (PMC) monolayer that lines the abdominal cavity is the first barrier encountered by OvCA cells. Subsequent progression of tumors through the peritoneum leads to the accumulation into the peritoneal stroma of a sizeable population of carcinoma-associated fibroblasts (CAFs), which is mainly originated from a mesothelial-to-mesenchymal transition (MMT) process. A common characteristic of OvCA patients is the intraperitoneal accumulation of ascitic fluid, which is composed of cytokines, chemokines, growth factors, miRNAs, and proteins contained in exosomes, as well as tumor and mesothelial suspended cells, among other components that vary in proportion between patients. Exosomes are small extracellular vesicles that have been shown to mediate peritoneal metastasis by educating a pre-metastatic niche, promoting the accumulation of CAFs via MMT, and inducing tumor growth and chemoresistance. This review summarizes and discusses the pivotal role of exosomes and MMT as mediators of OvCA peritoneal colonization and as emerging diagnostic and therapeutic targets.

Crosstalk between H1975 tumor cells and platelets to induce the proliferation, migration and tube formation of vascular endothelial cells

Activated platelets (PLTs) participate in the regulation of tumor angiogenesis, and tumors can activate PLTs. Whether co-culture of lung carcinoma with PLTs improves the function of human umbilical vein endothelial cells (HUVECs) requires further investigation. The present study aimed to investigate the impact of H1975 cell crosstalk with PLTs on the proliferation, migration and tube formation of HUVECs. Following generation of cell-derived supernatants and construction of the co-culture system, Cell Counting Kit-8, flow cytometry, transmission electron microscopy and a meter for epithelial measurement were performed to detect the proliferative ability of HUVECs. Furthermore, the wound healing and Transwell migration assays were performed to detect the migratory ability of HUVECs. A tube formation assay was performed to assess angiogenesis, ELISA was applied to detect the content of vascular endothelial growth factor (VEGF) and western blotting was carried out to measure the expression levels of VEGF receptor 2 (VEGFR2) in HUVECs. Compared with single-cultured HUVECs (control), co-culture with H1975 cells and PLTs (Exp_HP) improved cell proliferation, increased the proportion of cells in the S-phase, destroyed the cell ultrastructure and decreased transepithelial electrical resistance in HUVECs. In addition, a higher relative migration rate, greater number of migrated cells, stronger tube-forming ability and increased expression of VEGF and VEGFR2 were detected in the Exp_HP group compared with the control group. The properties of HUVECs in Exp_H (co-cultured with H1975 cells) were similar to those in Exp_HP, but significantly weaker. Taken together, the results of the present study suggest that tumor cells interacting with PLTs may play an important role in tumor angiogenesis by affecting or mediating changes in the properties of vascular endothelial cells (VECs).

Exosomes from cervical cancer cells facilitate pro-angiogenic endothelial reconditioning through transfer of Hedgehog-GLI signaling components

BACKGROUND

Angiogenic switch is a hallmark feature of transition from low-grade to high-grade cervical intraepithelial neoplasia (CIN) in cervical cancer progression. Therefore, early events leading to locally-advanced cervical metastatic lesions demand a greater understanding of the underlying mechanisms. Recent leads indicate the role of tumor-derived exosomes in altering the functions of endothelial cells in cervical cancer, which needs further investigation.

METHODS

Exosomes isolated from cervical cancer cell lines were assessed for their angiogenic effect on the human umbilical vein endothelial cells (HUVEC) using tube formation and wound healing assay. The exosomal uptake by HUVEC cells was monitored using PKH-67 labelling followed by fluorescence microscopy. Alterations in Hh-GLI signaling components, PTCH1 and GLI1, in HUVEC were measured by immunoblotting. Changes in angiogenesis-related transcripts of vascular endothelial growth factor VEGF-A, VEGF-B, VEGFR2 and angiopoietin-1, angiopoietin-2, osteopontin were measured in exosome-treated HUVEC and in the exosomal RNA by RT-PCR.

RESULTS

Enhanced tube formation, with an increased number of nodes and branching was observed in HUVEC's treated with exosomes derived from different cervical cancer cell lines. HPV-positive (SiHa and HeLa) cells' exosomes were more angiogenic. Exosome-treated HUVEC showed increased migration rate. PKH-67 labelled exosomes were found internalized in HUVEC. A high level of PTCH1 protein was detected in the exosome-treated endothelial cells. Subsequent RT-PCR analysis showed increased transcripts of Hh-GLI downstream target genes VEGF-A, VEGFR2, angiopoietin-2, and decreased expression of VEGF-B, and angiopoietin-1, suggestive of active Hh-GLI signaling. These effects were more pronounced in HUVEC's treated with exosomes of HPV-positive cells. However, these effects were independent of tumor-derived VEGF-A as exosomal cargo lacked VEGF-A transcripts or proteins.

CONCLUSION

Overall, the data showed cervical cancer exosomes promote pro-angiogenic response in endothelial cells via upregulation of Hh-GLI signaling and modulate downstream angiogenesis-related target genes. The study provides a novel exosome-mediated mechanism potentially favoring cervical angiogenesis and thus identifies the exosomes as potential pharmacological targets against locally-advanced metastatic cervical lesions.

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

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