Pancreatic cancer cell-derived exosomes induce epithelial-mesenchymal transition in human pancreatic cancer cells themselves partially via transforming growth factor β1

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

The incorporation of acetylated LAP-TGF-β1 proteins into exosomes promotes TNBC cell dissemination in lung micro-metastasis

Triple-negative breast cancer (TNBC) stands as the breast cancer subtype with the highest recurrence and mortality rates, with the lungs being the common site of metastasis. The pulmonary microenvironment plays a pivotal role in the colonization of disseminated tumor cells. Herein, this study highlights the crucial role of exosomal LAP-TGF-β1, the principal form of exosomal TGF-β1, in reshaping the pulmonary vascular niche, thereby facilitating TNBC lung metastasis. Although various strategies have been developed to block TGF-β signaling and have advanced clinically, their significant side effects have limited their therapeutic application. This study demonstrates that in lung metastatic sites, LAP-TGF-β1 within exosomes can remarkably reconfigure the pulmonary vascular niche at lower doses, bolstering the extravasation and colonization of TNBC cells in the lungs. Mechanistically, under the aegis of the acetyltransferase TIP60, a non-canonical KFERQ-like sequence in LAP-TGF-β1 undergoes acetylation at the K304 site, promoting its interaction with HSP90A and subsequent transport into exosomes. Concurrent inhibition of both HSP90A and TIP60 significantly diminishes the exosomal burden of LAP-TGF-β1, presenting a promising therapeutic avenue for TNBC lung metastasis. This study not only offers fresh insights into the molecular underpinnings of TNBC lung metastasis but also lays a foundation for innovative therapeutic strategies.

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

Exosome-mediated tumor metastasis: Biology, molecular targets and immuno-therapeutic options

Small extracellular vesicles called exosomes play a crucial part in promoting intercellular communication. They act as intermediaries for the exchange of bioactive chemicals between cells, released into the extracellular milieu by a variety of cell types. Within the context of cancer progression, metastasis is a complex process that plays a significant role in the spread of malignant cells from their main site of origin to distant anatomical locations. This complex process plays a key role in the domain of cancer-related deaths. In summary, the trajectory of current research in the field of exosome-mediated metastasis is characterized by its unrelenting quest for more profound understanding of the molecular nuances, the development of innovative diagnostic tools and therapeutic approaches, and the unwavering dedication to transforming these discoveries into revolutionary clinical applications. This unrelenting pursuit represents a shared desire to improve the prognosis for individuals suffering from metastatic cancer and to nudge the treatment paradigm in the direction of more effective and customized interventions.

Wnt7a is Required for Regeneration of Dystrophic Skeletal Muscle

Intramuscular injection of Wnt7a has been shown to accelerate and augment skeletal muscle regeneration and to ameliorate dystrophic progression in mdx muscle, a model for Duchenne muscular dystrophy (DMD). However, loss-of-function studies to investigate the requirement for Wnt7a in muscle regeneration has not been evaluated. Here, we assessed muscle regeneration and function in wild type (WT) and mdx mice where Wnt7a was specifically deleted in muscle using a conditional Wnt7a floxed allele and a Myf5-Cre driver. We found that both WT and mdx mice with deletion of Wnt7a in muscle, exhibited marked deficiencies in muscle regeneration at 21 d following cardiotoxin (CTX) induced injury. Unlike WT, deletion of Wnt7a in mdx resulted in a marked decrease in specific force generation prior to CTX injury. However, both WT and mdx muscle lacking Wnt7a displayed decreased specific force generation following CTX injection. Notably the regeneration deficit observed in mdx mice lacking Wnt7a in muscle was rescued by a single tail vein injection of an extracellular vesicle preparation containing Wnt7a (Wnt7a-EVs). Therefore, we conclude that the regenerative capacity of muscle in mdx mice is due to the upregulation of endogenous Wnt7a following injury, and that systemic delivery of Wnt7a-EVs represents a therapeutic strategy for treating DMD.

Simultaneously targeting extracellular vesicle trafficking and TGF-β receptor kinase activity blocks signaling hyperactivation and metastasis

Metastasis is the leading cause of cancer-related deaths. Transforming growth factor beta (TGF-β) signaling drives metastasis and is strongly enhanced during cancer progression. Yet, the use of on-target TGF-β signaling inhibitors in the treatment of cancer patients remains unsuccessful, highlighting a gap in the understanding of TGF-β biology that limits the establishment of efficient anti-metastatic therapies. Here, we show that TGF-β signaling hyperactivation in breast cancer cells is required for metastasis and relies on increased small extracellular vesicle (sEV) secretion. Demonstrating sEV's unique role, TGF-β signaling levels induced by sEVs exceed the activity of matching concentrations of soluble ligand TGF-β. Further, genetic disruption of sEV secretion in highly-metastatic breast cancer cells impairs cancer cell aggressiveness by reducing TGF-β signaling to nearly-normal levels. Otherwise, TGF-β signaling activity in non-invasive breast cancer cells is inherently low, but can be amplified by sEVs, enabling invasion and metastasis of poorly-metastatic breast cancer cells. Underscoring the translational potential of inhibiting sEV trafficking in advanced breast cancers, treatment with dimethyl amiloride (DMA) decreases sEV secretion, TGF-β signaling activity, and breast cancer progression in vivo. Targeting both the sEV trafficking and TGF-β signaling by combining DMA and SB431542 at suboptimal doses potentiated this effect, normalizing the TGF-β signaling in primary tumors to potently reduce circulating tumor cells, metastasis, and tumor self-seeding. Collectively, this study establishes sEVs as critical elements in TGF-β biology, demonstrating the feasibility of inhibiting sEV trafficking as a new therapeutic approach to impair metastasis by normalizing TGF-β signaling levels in breast cancer cells.

Small extracellular vesicle TGF-β in cancer progression and immune evasion

Transforming growth factor-β (TGF-β) is a well-known cytokine that controls various processes in normal physiology and disease context. Strong preclinical and clinical literature supports the crucial roles of the TGF-β in several aspects of cancer biology. Recently emerging evidence reveals that the release of TGF-β from tumor/immune/stromal cells in small extracellular vesicles (sEVs) plays an important part in tumor development and immune evasion. Hence, this review aims to address the packaging, release, and signaling pathways of TGF-β carried in sEVs (sEV-TGF-β) in cancer, and to explore its underpinning roles in tumor development, growth, progression, metastasis, etc. We also highlight key progresses in deciphering the roles of sEV-TGF-β in subverting anti-tumor immune responses. The paper ends with a focus on the clinical significance of TGF-β carried in sEVs and draws attention to its diagnostic, therapeutic, and prognostic importance.

Exosomes in ascites from patients with human pancreatic cancer enhance remote metastasis partially through endothelial-mesenchymal transition

BACKGROUND

Despite advances in multidisciplinary treatment, the prognosis of pancreatic cancer remains poor. Since distant metastasis defines prognosis, elucidation of the mechanism of metastasis is important for improving survival. Exosomes are extracellular secretory vesicles and are responsible for intercellular communication. In this study, we investigated whether exosomes secreted by human pancreatic cancer cells are involved in promoting distant metastasis of cancer and the mechanism that underlies the promotion of metastasis.

METHODS

Exosomes were isolated from ascites of a patient with pancreatic cancer and a patient with liver cirrhosis as a control. Three days after the administration of exosomes to nude mice, GFP-labeled human pancreatic cancer cells were injected via the spleen or tail vein, and then the liver and lungs were histologically analyzed. To elucidate the mechanism, vascular permeability was estimated using FITC-dextran in place of pancreatic cancer cells in vivo and human umbilical vascular endothelial cells (HUVECs) were used to analyze vascular permeability and the induction of endothelial-mesenchymal transition (EndMT) in vitro.

RESULTS

Distant metastasis and vascular permeability were significantly enhanced in mice treated with exosomes from pancreatic cancer patients in comparison to exosomes from a control patient in vivo. In addition, exosomes from pancreatic cancer patients significantly enhanced vascular permeability and the induction of EndMT in HUVECs in vitro.

CONCLUSION

Exosomes derived from pancreatic cancer cells form a pre-metastatic niche and promote the extravasation and colonization of pancreatic cancer cells to remote organs, partially through endothelial-mesenchymal transition.