Microenvironmental Hypoxia Induces Dynamic Changes in Lung Cancer Synthesis and Secretion of Extracellular Vesicles

RIPK2 and lysosomal pathway: Unveiling a new mechanism for lung cancer metastasis

BACKGROUND

This study aims to explore the role of RIPK2 in lung cancer metastasis and its potential mechanisms.

METHODS

The expression levels of RIPK2 in lung cancer patients and cell lines were detected by immunohistochemistry, qRT-PCR, and Western blot. RIPK2 expression was knocked down using siRNA technology, and its effects on the proliferation, migration, and invasion capabilities of lung cancer cells were assessed through CCK-8, EdU, colony formation, and Transwell assays. Furthermore, by overexpressing RIPK2 and LAMP2, the regulatory effect of RIPK2 on the lysosomal pathway and its mechanism of action in lung cancer metastasis were investigated.

RESULTS

The results showed that the expression of RIPK2 was significantly increased in lung cancer patients and cell lines. Knockdown of RIPK2 significantly inhibited the migration, invasion, and proliferation capabilities of lung cancer cells, while overexpression of RIPK2 promoted these malignant behaviors. Further studies found that RIPK2 promoted lung cancer metastasis by inhibiting LAMP2 expression, thereby suppressing the lysosomal pathway and altering the tumor microenvironment. Additionally, overexpression of LAMP2 could reverse the promotive effects of RIPK2 overexpression on the malignant behaviors of lung cancer cells.

CONCLUSION

This study reveals for the first time that RIPK2 promotes lung cancer metastasis by inhibiting LAMP2 expression, thereby suppressing the lysosomal pathway and altering the tumor microenvironment. In the future, targeted therapy against RIPK2 and LAMP2 may become an effective means to inhibit lung cancer metastasis.

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

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.

Tissue-derived extracellular vesicles in cancer progression: mechanisms, roles, and potential applications

Extracellular vesicles (EVs) are small lipid bilayer-enclosed vesicles that mediate vital cellular communication by transferring cargo between cells. Among these, tissue-derived extracellular vesicles (Ti-EVs) stand out due to their origin from the tissue microenvironment, providing a more accurate reflection of changes in this setting. This unique advantage makes Ti-EVs valuable in investigating the intricate relationship between extracellular vesicles and cancer progression. Despite considerable research efforts exploring the association between Ti-EVs and cancers, a comprehensive clustering or grouping of these studies remains lacking. In this review, we aim to fill this gap by presenting a comprehensive synthesis of the mechanisms underlying Ti-EV generation, release, and transport within cancer tissues. Moreover, we delve into the pivotal roles that Ti-EVs play in cancer progression, shedding light on their potential as diagnostic and therapeutic tools. The review culminates in the construction of a comprehensive functional spectrum of Ti-EVs, providing a valuable reference for future research endeavors. By summarizing the current state of knowledge on Ti-EVs and their significance in tumor biology, this work contributes to a deeper understanding of cancer microenvironment dynamics and opens up avenues for harnessing Ti-EVs in diagnostic and therapeutic applications.

Extracellular vesicles from UTX-knockout endothelial cells boost neural stem cell differentiation in spinal cord injury

BACKGROUND

Vascular endothelial cells are pivotal in the pathophysiological progression following spinal cord injury (SCI). The UTX (Ubiquitously Transcribed Tetratripeptide Repeat on Chromosome X) serves as a significant regulator of endothelial cell phenotype. The manipulation of endogenous neural stem cells (NSCs) offers a compelling strategy for the amelioration of SCI.

METHODS

Two mouse models were used to investigate SCI: NSCs lineage-traced mice and mice with conditional UTX knockout (UTX KO) in endothelial cells. To study the effects of UTX KO on neural differentiation, we harvested extracellular vesicles (EVs) from both UTX KO spinal cord microvascular endothelial cells (SCMECs) and negative control SCMECs. These EVs were then employed to modulate the differentiation trajectory of endogenous NSCs in the SCI model.

RESULTS

In our NSCs lineage-traced mice model of SCI, a marked decrease in neurogenesis was observed post-injury. Notably, NSCs in UTX KO SCMECs mice showed enhanced neuronal differentiation compared to controls. RNA sequencing and western blot analyses revealed an upregulation of L1 cell adhesion molecule (L1CAM), a gene associated with neurogenesis, in UTX KO SCMECs and their secreted EVs. This aligns with the observed promotion of neurogenesis in UTX KO conditions. In vivo administration of L1CAM-rich EVs from UTX KO SCMECs (KO EVs) to the mice significantly enhanced neural differentiation. Similarly, in vitro exposure of NSCs to KO EVs resulted in increased activation of the Akt signaling pathway, further promoting neural differentiation. Conversely, inhibiting Akt phosphorylation or knocking down L1CAM negated the beneficial effects of KO EVs on NSC neuronal differentiation.

CONCLUSIONS

In conclusion, our findings substantiate that EVs derived from UTX KO SCMECs can act as facilitators of neural differentiation following SCI. This study not only elucidates a novel mechanism but also opens new horizons for therapeutic interventions in the treatment of SCI. Video Abstract.

The hypoxia-associated genes in immune infiltration and treatment options of lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is a common lung cancer with a poor prognosis under standard chemotherapy. Hypoxia is a crucial factor in the development of solid tumors, and hypoxia-related genes (HRGs) are closely associated with the proliferation of LUAD cells.

Methods

In this study, LUAD HRGs were screened, and bioinformatics analysis and experimental validation were conducted. The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases were used to gather LUAD RNA-seq data and accompanying clinical information. LUAD subtypes were identified by unsupervised cluster analysis, and immune infiltration analysis of subtypes was conducted by GSVA and ssGSEA. Cox regression and LASSO regression analyses were used to obtain prognosis-related HRGs. Prognostic analysis was used to evaluate HRGs. Differences in enrichment pathways and immunotherapy were observed between risk groups based on GSEA and the TIDE method. Finally, RT-PCR and in vitro experiments were used to confirm prognosis-related HRG expression in LUAD cells.

Results

Two hypoxia-associated subtypes of LUAD were distinguished, demonstrating significant differences in prognostic analysis and immunological characteristics between subtypes. A prognostic model based on six HRGs (HK1, PDK3, PFKL, SLC2A1, STC1, and XPNPEP1) was developed for LUAD. HK1, SLC2A1, STC1, and XPNPEP1 were found to be risk factors for LUAD. PDK3 and PFKL were protective factors in LUAD patients.

Conclusion

This study demonstrates the effect of hypoxia-associated genes on immune infiltration in LUAD and provides options for immunotherapy and therapeutic strategies in LUAD.

pSILAC-Based Determination of Cellular Protein Sorting into Extracellular Vesicles

The protein cargo of extracellular vesicles (EVs) determines their impact on recipient cell types and the downstream effects on biological function. Environmental cues can modify EV loading with proteins derived from the plasma membrane via endocytosis, obtained from the preexisting cytosolic pool via active sorting, or packaging with newly synthesized proteins drawn from trans-golgi networks. Given the major impact these pathways exert on EV content and functional potential, it is important to study how defined stimuli influence protein sorting into these vesicles for dispersal. To this end, pSILAC-based approaches can be used to pulse/trace the origins of EV protein content and thereby provide valuable insight into vesicle biology and likely effects on intercellular communication in diverse settings.

Boosting extracellular vesicle secretion

In recent years, extracellular vesicles (EVs), specifically exosomes, have emerged as a promising strategy for treating a wide spectrum of pathologies, such as cancer and COVID-19, as well as promoting tissue regeneration in various conditions, including cardiomyopathies and spinal cord injuries. Despite the great potential of EV-based therapies, poor yield and unscalable production of EVs remain big challenges to overcome to translate these types of treatment to clinical practices. Here, we review different strategies for enhancing EV yield by physical, biological or chemical means. Some of these novel approaches can lead to about 100-fold increase in EV production yield, thus bringing closer the clinical translation with regard to scalability and efficiency.

Extracellular Vesicles—A New Potential Player in the Immunology of Renal Cell Carcinoma

The incidence of renal cell carcinoma (RCC) has doubled in the developed world within the last fifty years, and now it is responsible for 2–3% of diagnosed cancers. The delay in diagnosis and the not fully understood pathogenesis are the main challenges that have to be overcome. It seems that extracellular vesicles (EVs) are one of the key players in tumor development since they ensure a proper microenvironment for the tumor cells. The stimulation of angiogenesis and immunosuppression is mediated by molecules contained in EVs. It was shown that EVs derived from cancer cells can inhibit T cell proliferation, natural killer lymphocyte activation, and dendritic cell maturation by this mechanism. Moreover, EVs may be a biomarker for the response to anti-cancer treatment. In this review, we sum up the knowledge about the role of EVs in RCC pathogenesis and show their future perspectives in this field.

The CD70-CD27 axis in oncology: the new kids on the block

The immune checkpoint molecule CD70 and its receptor CD27 are aberrantly expressed in many hematological and solid malignancies. Dysregulation of the CD70-CD27 axis within the tumor and its microenvironment is associated with tumor progression and immunosuppression. This is in contrast to physiological conditions, where tightly controlled expression of CD70 and CD27 plays a role in co-stimulation in immune responses. In hematological malignancies, cancer cells co-express CD70 and CD27 promoting stemness, proliferation and survival of malignancy. In solid tumors, only expression of CD70 is present on the tumor cells which can facilitate immune evasion through CD27 expression in the tumor microenvironment. The discovery of these tumor promoting and immunosuppressive effects of the CD70-CD27 axis has unfolded a novel target in the field of oncology, CD70.

In this review, we thoroughly discuss current insights into expression patterns and the role of the CD70-CD27 axis in hematological and solid malignancies, its effect on the tumor microenvironment and (pre)clinical therapeutic strategies.

Identification of immune subtypes of cervical squamous cell carcinoma predicting prognosis and immunotherapy responses

Background

The main limitation of current immune checkpoint inhibitors (ICIs) in the treatment of cervical cancer comes from the fact that it benefits only a minority of patients. The study aims to develop a classification system to identify immune subtypes of cervical squamous cell carcinoma (SCC), thereby helping to screen candidates who may respond to ICIs.

Methods

A real-world cervical SCC cohort of 36 samples were analyzed. We used a nonnegative matrix factorization (NMF) algorithm to separate different expression patterns of immune-related genes (IRGs). The immune characteristics, potential immune biomarkers, and somatic mutations were compared. Two independent data sets containing 555 samples were used for validation.

Results

Two subtypes with different immunophenotypes were identified. Patients in sub1 showed favorable progression-free survival (PFS) and overall survival (OS) in the training and validation cohorts. The sub1 was remarkably related to increased immune cell abundance, more enriched immune activation pathways, and higher somatic mutation burden. Also, the sub1 group was more sensitive to ICIs, while patients in the sub2 group were more likely to fail to respond to ICIs but exhibited GPCR pathway activity. Finally, an 83-gene classifier was constructed for cervical SCC classification.

Conclusion

This study establishes a new classification to further understand the immunological diversity of cervical SCC, to assist in the selection of candidates for immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02894-3.

Microvesicles - promising tiny players' of cancer stem cells targeted liver cancer treatments: The interesting interactions and therapeutic aspects

Liver cancer is one of the most malignant cancers worldwide with poor prognosis. Intracellular mediators like microvesicles (MVs) and cancer stem cells (CSCs) are considered as potential candidates in liver cancer progression. CSCs receive stimuli from the tumor microenvironment to initiate tumor formation in which it's secreted MVs play a noteworthy role. The phenotypic conversion of tumor cells during epithelial-to-mesenchymal transition (EMT) is a key step in tumor invasion and metastasis which indicates that the diverse cell populations within the primary tumor are in a dynamic balance and can be regulated by cell to cell communication via secreted microvesicles. Thus, in this review, we aim to highlight the evidences that suggest CSCs are crucial for liver cancer development where the microvesicles plays an important part in the maintenance of its stemness properties. In addition, we summarize the existing evidences that support the concept of microvesicles, the tiny particles have a big role behind the rare immortal CSCs which controls the tumor initiation, propagation and metastasis in liver cancer. Identifying interactions between CSCs and microvesicles may offer new insights into precise anti-cancer therapies in the future.