Functions and clinical significance of mechanical tumor microenvironment: cancer cell sensing, mechanobiology and metastasis

A TICT-AIE activated dual-channel fluorescence-on probe to reveal the dynamics mechanosensing of lipid droplets during ferroptosis

Mechanical forces play a crucial role in cellular processes, including ferroptosis, a form of regulated cell death associated with various diseases. However, the mechanical aspects of organelle lipid droplets (LDs) during ferroptosis are poorly understood. In this study, we designed and synthesized a fluorescent probe, TPE-V1, to enable real-time monitoring of LDs' viscosity using a dual-channel fluorescence-on model (red channel at 617 nm and NIR channel at 710 nm). The fluorescent imaging of using TPE-V1 was achieved due to the integrated mechanisms of the twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE). Through dual-emission channel fluorescence imaging, we observed the enhanced mechanical energy of LDs triggering cellular mechanosensing, including ferroptosis and cell deformation. Theoretical calculations confirmed the probe's behavior, showing that high-viscosity media prevented the rotation processes and restored fluorescence quenching in low viscosity. These findings suggest that our TICT-TPE design strategy provides a practical approach to study LDs' mechanical properties during ferroptosis. This development enhances our understanding of the interplay between mechanical forces and LDs, contributing to the knowledge of ferroptotic cell death and potential therapeutic interventions targeting dysregulated cell death processes.

Mechanical shear flow regulates the malignancy of colorectal cancer cells

Colorectal cancer (CRC) is notable for its high mortality and high metastatic characteristics. The shear force generated by bloodstream provides mechanical signals regulating multiple responses of cells, including metastatic cancer cells, dispersing in blood vessels. We, therefore, studied the effect of shear flow on circulating CRC cells in the present study. The CRC cell line SW620 was subjected to shear flow of 12.5 dynes/cm2 for 1 and 2 h separately. Resulting elevated caspase-9 and -3 indicated that shear flow initiated the apoptosis of SW620. Enlarged cell size associated with a higher level of cyclin D1 was coincident with the flow cytometric results indicating that the cell cycle was arrested at the G1 phase. An elevated phosphor-eNOSS1177 increased the production of nitric oxide and led to reactive oxygen species-mediated oxidative stress. Shear flow also regulated epithelial-mesenchymal transition (EMT) by increasing E-cadherin and ZO-1 while decreasing Snail and Twist1. The migration and invasion of sheared SW620 were also substantially decreased. Further investigations showed that mitochondrial membrane potential was significantly decreased, whereas mitochondrial mass and ATP production were not changed. In addition to the shear flow of 12.5 dynes/cm2, the expressions of EMT were compared at lower (6.25 dynes/cm2) and at higher (25 dynes/cm2) shear flow. The results showed that lower shear flow increased mesenchymal characteristics and higher shear flow increased epithelial characteristics. Shear flow reduces the malignancy of CRC in their metastatic dispersal that opens up new ways to improve cancer therapies by applying a mechanical shear flow device.

Synergistic Effects of Matrix Biophysical Properties on Gastric Cancer Cell Behavior via Integrin-Mediated Cell-ECM Interactions

The biophysical properties of the extracellular matrix (ECM) play a pivotal role in modulating cancer progression via cell-ECM interactions. However, the biophysical properties specific to gastric cancer (GC) remain largely unexplored. Pertinently, GC ECM shows significantly heterogeneous metamorphoses, such as matrix stiffening and intricate restructuring. By combining collagen I and alginate, this study designs an in vitro biomimetic hydrogel platform to independently modulate matrix stiffness and structure across a physiological stiffness spectrum while preserving consistent collagen concentration and fiber topography. With this platform, this study assesses the impacts of matrix biophysical properties on cell proliferation, migration, invasion, and other pivotal dynamics of AGS. The findings spotlight a compelling interplay between matrix stiffness and structure, influencing both cellular responses and ECM remodeling. Furthermore, this investigation into the integrin/actin-collagen interplay reinforces the central role of integrins in mediating cell-ECM interactions, reciprocally sculpting cell conduct, and ECM adaptation. Collectively, this study reveals a previously unidentified role of ECM biophysical properties in GC malignant potential and provides insight into the bidirectional mechanical cell-ECM interactions, which may facilitate the development of novel therapeutic horizons.

Vessel co-option: a unique vascular-immune niche in liver cancer

Tumor vasculature is pivotal in regulating tumor perfusion, immune cell infiltration, metastasis, and invasion. The vascular status of the tumor is intricately linked to its immune landscape and response to immunotherapy. Vessel co-option means that tumor tissue adeptly exploits pre-existing blood vessels in the para-carcinoma region to foster its growth rather than inducing angiogenesis. It emerges as a significant mechanism contributing to anti-angiogenic therapy resistance. Different from angiogenic tumors, vessel co-option presents a distinctive vascular-immune niche characterized by varying states and distribution of immune cells, including T-cells, tumor-associated macrophages, neutrophils, and hepatic stellate cells. This unique composition contributes to an immunosuppressive tumor microenvironment that is crucial in modulating the response to cancer immunotherapy. In this review, we systematically reviewed the evidence and molecular mechanisms of vessel co-option in liver cancer, while also exploring its implications for anti-angiogenic drug resistance and the immune microenvironment, to provide new ideas and clues for screening patients with liver cancer who are effective in immunotherapy.

Natural Killer Cell Mechanosensing in Solid Tumors

Natural killer (NK) cells, which are an exciting alternative cell source for cancer immunotherapies, must sense and respond to their physical environment to traffic to and eliminate cancer cells. Herein, we review the mechanisms by which NK cells receive mechanical signals and explore recent key findings regarding the impact of the physical characteristics of solid tumors on NK cell functions. Data suggest that different mechanical stresses present in solid tumors facilitate NK cell functions, especially infiltration and degranulation. Moreover, we review recent engineering advances that can be used to systemically study the role of mechanical forces on NK cell activity. Understanding the mechanisms by which NK cells interpret their environment presents potential targets to enhance NK cell immunotherapies for the treatment of solid tumors.

Biomechanical forces and force-triggered drug delivery in tumor neovascularization

Tumor angiogenesis is one of the typical hallmarks of tumor occurrence and development, and tumor neovascularization also exhibits distinct characteristics from normal blood vessels. As the number of cells and matrix inside the tumor increases, the biomechanical force is enhanced, specifically manifested as solid stress, fluid stress, stiffness, and topology. This mechanical microenvironment also provides shelter for tumors and intensifies angiogenesis, providing oxygen and nutritional support for tumor progression. During tumor development, the biomechanical microenvironment also emerges, which in turn feeds back to regulate the tumor progression, including tumor angiogenesis, and biochemical and biomechanical signals can regulate tumor angiogenesis. Blood vessels possess inherent sensitivity to mechanical stimuli, but compared to the extensive research on biochemical signal regulation, the study of the regulation of tumor neovascularization by biomechanical signals remains relatively scarce. Biomechanical forces can affect the phenotypic characteristics and mechanical signaling pathways of tumor blood vessels, directly regulating angiogenesis. Meanwhile, they can indirectly regulate tumor angiogenesis by causing an imbalance in angiogenesis signals and affecting stromal cell function. Understanding the regulatory mechanism of biomechanical forces in tumor angiogenesis is beneficial for better identifying and even taming the mechanical forces involved in angiogenesis, providing new therapeutic targets for tumor vascular normalization. Therefore, we summarized the composition of biomechanical forces and their direct or indirect regulation of tumor neovascularization. In addition, this review discussed the use of biomechanical forces in combination with anti-angiogenic therapies for the treatment of tumors, and biomechanical forces triggered delivery systems.

[The Three-dimensional Environment of Type Ⅰ Collagen Gels With Varying Stiffness Modulates the Immunological Functions of NK Cells]

Objective

To construct type Ⅰ collagen gels with different stiffness and to investigate the effects of three-dimensional (3D) culture environments of the gels on the morphology, free migration ability, and cell killing function of natural killer (NK) cells.

Methods

Type Ⅰ collagen was isolated from the tails of Sprague Dawley (SD) rats and collagen gels with different levels of stiffnesses were prepared accordingly. The microstructure of the collagen gels was observed by laser confocal microscopy. The stiffness of the collagen gels was assessed by measuring the plateau modulus with a rheometer. NK-92MI cells were cultured in collagen gels with different levels of stiffness. The morphology of NK-92MI cells was observed by inverted microscope. High content imaging system was used to record the free migration process of NK-92MI cells and analyze the migration speed and distance. NK-92MI cells were cultured with type Ⅰ collagen gels with different levels of stiffness for 24 h and 48 h and, then, co-cultured with human colorectal DLD-1, a human adenocarcinoma epithelial cell line. CCK8 assay was performed to determine the proliferation rate of DLD-1 cells and analyze the cell killing ability of NK-92MI cells.

Results

Low-stiffness type Ⅰ collagen gel and high-stiffness type Ⅰ collagen gel with the respective stiffness of (10.970±2.10) Pa and (114.50±3.40) Pa were successfully prepared. Compared with those cultured with the low-stiffness type Ⅰ collagen gel, the NK-92MI cells in the high-stiffness type Ⅰ collagen gel showed a more elongated shape (P<0.05), the mean area of the cells was reduced ([69.88±26.97] μm2 vs. [46.59±21.62] μm2, P<0.05), the roundness of the cells decreased (0.82±0.12 vs. 0.78±0.18, P<0.05), cell migration speed decreased ([2.50±0.91] μm/min vs. [1.70±0.72] μm/min, P<0.001) and the migration distance was shortened ([147.10±53.74] μm vs. [98.03± 40.95] μm, P<0.0001), with all the differences being statistically significant. Compared with those cultured with the low-stiffness type Ⅰ collagen gel, NK-92MI cells cultured with high-stiffness type Ⅰ collagen gel for 24 h could promote DLD-1 cell proliferation, with the proliferation rate being (46.39±12.79)% vs. (65.87±4.45)% (P<0.05) and reduce the cell killing ability. Comparison of the cells cultured for 48 h led to similar results, with the proliferation rates being (31.36±2.88)% vs. (74.57±2.16)% (P<0.05), and the differences were all statistically significant.

Conclusion

The 3D culture environment of type Ⅰ collagen gels with different levels of stiffness alters the morphology, migration ability, and killing function of NK-92MI cells. This study provides the research basis for exploring and understanding the mechanisms by which the biomechanical microenvironment affects the immune response of NK cells, as well as laying the theoretical foundation for optimizing immunotherapy protocols.

[Hot Topics and Emerging Trends in Mechanobiology Research]

Mechanobiology focuses on a series of important physiopathological processes, such as how cells perceive different mechanomechanical stimuli, the process of intracellular mechanotransduction, and how mechanical signals determine the behavior and fate of cells. From the initial stage of embryogenesis, to developmental biology and regenerative medicine, or even through the whole life process, mechanical signaling cascades and cellular mechanical responses in mechanobiology are of great significance in biomedical research. In recent years, research in the field of mechanobiology has undergone remarkable development. Several scientific consortia around the world have been analyzing mechanobiological processes from different perspectives, aiming to gain insights into the regulatory mechanisms by which mechanical factors affect cell fate determination. In this article, we summarized and reviewed the topics that have attracted more research interests in recent years in the field of mechanobiology, for example, arterial blood vessels, stem cell, and ion channel. We also discussed the potential trends that may emerge, such as nuclear deformation, fibrous extracellular matrix, tumor mechanobiology, cellular mechanotransduction, and piezo ion channels. In addition, we put forward new ideas concerning the limitations of mechanism research and the importance of big data analysis and mining in this field, thereby providing objective support and a systematic framework for grasping the hot research topics and exploring new research directions in the field of mechanobiology.

[Hepatocellular Carcinoma-Derived Exosomes: Key Players in Intercellular Communication Within the Tumor Microenvironment]

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths in the world. Due to the insidious onset and rapid progression and a lack of effective treatments, the prognosis of patients with HCC is extremely poor, with the average 5-year survival rate being less than 10%. The tumor microenvironment (TME), the internal environment in which HCC develops, can regulate the oncogenesis, development, invasion, and metastasis of HCC. During the process of cancer progression, HCC cells can regulate the biological behaviors of tumor cells, cancer-associated fibroblasts, cancer-associated immune cells, and other cells in the TME by releasing exosomes containing specific signals, thereby promoting cancer progression. However, the exact molecular mechanisms and the roles of exosomes in the specific cellular regulation of these processes are not fully understood. Herein, we summarized the TME components of HCC, the sources and the biological traits of exosomes in the TME, and the impact of mechanical factors on exosomes. In addition, special attention was given to the discussion of the effects of HCC-exosomes on different types of cells in the microenvironment. There are still many difficulties to be overcome before exosomes can be applied as carriers in clinical cancer treatment. First of all, the homogeneity of exosomes is difficult to ensure. Secondly, exosomes are mainly administered through subcutaneous injection. Although this method is simple and easy to implement, the absorption efficiency is not ideal. Thirdly, exosome extraction methods are limited in number and inefficient, making it difficult to prepare exosomes in large quantities. It is important to ensure that exosomes are used in sufficient quantities to trigger an effective tumor immune response, especially for exosome-mediated tumor immunotherapy. With the improvement in identification, isolation, and purification technology, exosomes are expected to be successfully used in the clinical diagnosis of early-stage HCC and the clinical treatment of liver cancer.

Cancer Metastasis-on-a-Chip for Modeling Metastatic Cascade and Drug Screening

Microfluidic chips are valuable tools for studying intricate cellular and cell-microenvironment interactions. Traditional in vitro cancer models lack accuracy in mimicking the complexities of in vivo tumor microenvironment. However, cancer-metastasis-on-a-chip (CMoC) models combine the advantages of 3D cultures and microfluidic technology, serving as powerful platforms for exploring cancer mechanisms and facilitating drug screening. These chips are able to compartmentalize the metastatic cascade, deepening the understanding of its underlying mechanisms. This article provides an overview of current CMoC models, focusing on distinctive models that simulate invasion, intravasation, circulation, extravasation, and colonization, and their applications in drug screening. Furthermore, challenges faced by CMoC and microfluidic technologies are discussed, while exploring promising future directions in cancer research. The ongoing development and integration of these models into cancer studies are expected to drive transformative advancements in the field.

Extracellular Matrix Cues Regulate Mechanosensing and Mechanotransduction of Cancer Cells

Extracellular biophysical properties have particular implications for a wide spectrum of cellular behaviors and functions, including growth, motility, differentiation, apoptosis, gene expression, cell-matrix and cell-cell adhesion, and signal transduction including mechanotransduction. Cells not only react to unambiguously mechanical cues from the extracellular matrix (ECM), but can occasionally manipulate the mechanical features of the matrix in parallel with biological characteristics, thus interfering with downstream matrix-based cues in both physiological and pathological processes. Bidirectional interactions between cells and (bio)materials in vitro can alter cell phenotype and mechanotransduction, as well as ECM structure, intentionally or unintentionally. Interactions between cell and matrix mechanics in vivo are of particular importance in a variety of diseases, including primarily cancer. Stiffness values between normal and cancerous tissue can range between 500 Pa (soft) and 48 kPa (stiff), respectively. Even the shear flow can increase from 0.1-1 dyn/cm2 (normal tissue) to 1-10 dyn/cm2 (cancerous tissue). There are currently many new areas of activity in tumor research on various biological length scales, which are highlighted in this review. Moreover, the complexity of interactions between ECM and cancer cells is reduced to common features of different tumors and the characteristics are highlighted to identify the main pathways of interaction. This all contributes to the standardization of mechanotransduction models and approaches, which, ultimately, increases the understanding of the complex interaction. Finally, both the in vitro and in vivo effects of this mechanics-biology pairing have key insights and implications for clinical practice in tumor treatment and, consequently, clinical translation.

Therapeutic In Situ Cancer Vaccine Using Pulsed Stereotactic Body Radiotherapy-A Translational Model

Both radiation and cancer therapeutic vaccine research are more than 100 years old, and their potential is likely underexplored. Antiangiogenics, nanoparticle targeting, and immune modulators are some other established anticancer therapies. In the meantime, immunotherapy usage is gaining momentum in clinical applications. This article proposes the concept of a pulsed/intermittent/cyclical endothelial-sparing single-dose in situ vaccination (ISVRT) schedule distinguishable from the standard therapeutic stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) plans. This ISVRT schedule can repeatedly generate tumor-specific neoantigens and epitopes for primary and immune modulation effects, augment supplementary immune enhancement techniques, activate long-term memory cells, avoid extracellular matrix fibrosis, and essentially synchronize with the vascular normalized immunity cycle. The core mechanisms of ISVRT impacting in situ vaccination would be optimizing cascading antigenicity and adjuvanticity. The present proposed hypothesis can be validated using the algorithm presented. The indications for the proposed concept are locally progressing/metastatic cancers that have failed standard therapies. Immunotherapy/targeted therapy, chemotherapy, antiangiogenics, and vascular-lymphatic normalization are integral to such an approach.

Mechanotransduction pathways in regulating epithelial-mesenchymal plasticity

The extracellular matrix (ECM) provides structural support for cells and mediates cell-stromal communications. In addition to ECM proteins, mechanical force exerted from the ECM serves as a critical regulator of many biological processes. Epithelial-mesenchymal transition (EMT) is a cellular process by which epithelial cells loosen their cellular junctions and migrate and invade in a more mesenchymal fashion. Recent studies show that increasing ECM stiffness can impinge on cellular signaling pathways through mechanotransduction to promote carcinoma cells to undergo EMT, suggesting that mechanical force exerted by the ECM plays a critical role in tumor invasion and metastasis. Here, we highlight recent work utilizing innovative approaches to study mechanotransduction and summarize newly discovered mechanisms by which mechanosensors and responders regulate EMT during tumor progression and metastasis.

3D Bioprinting as a Powerful Technique for Recreating the Tumor Microenvironment

In vitro three-dimensional models aim to reduce and replace animal testing and establish new tools for oncology research and the development and testing of new anticancer therapies. Among the various techniques to produce more complex and realistic cancer models is bioprinting, which allows the realization of spatially controlled hydrogel-based scaffolds, easily incorporating different types of cells in order to recreate the crosstalk between cancer and stromal components. Bioprinting exhibits other advantages, such as the production of large constructs, the repeatability and high resolution of the process, as well as the possibility of vascularization of the models through different approaches. Moreover, bioprinting allows the incorporation of multiple biomaterials and the creation of gradient structures to mimic the heterogeneity of the tumor microenvironment. The aim of this review is to report the main strategies and biomaterials used in cancer bioprinting. Moreover, the review discusses several bioprinted models of the most diffused and/or malignant tumors, highlighting the importance of this technique in establishing reliable biomimetic tissues aimed at improving disease biology understanding and high-throughput drug screening.

The emerging promise of tumour mechanobiology in cancer treatment

Tumour cell biomechanics has lately came to the fore as a disparate feature that fosters cancer development and progression. Tumour mechanosensing entails a mechanical interplay amongst tumour cells, extracellular matrix (ECM) and cells of the tumour microenvironment (TME). Sensory receptors (mechanoceptors) detect changes of extracellular mechanical inputs such as various types of mechanical forces/stress and trigger oncogenic signalling pathways advocating for cancer initiation, growth, survival, angiogenesis, invasion, metastasis, and immune evasion. Moreover, alterations in ECM stiffness and potentiation of mechanostimulated transcriptional regulatory molecules (transcription factors/cofactors) have been shown to strongly correlate with resistance to anticancer drugs. On this basis, new mechanosensitive proteins emerge as potential therapeutic targets and/or biomarkers in cancer. Accordingly, tumour mechanobiology arises as a promising field that can potentially provide novel combinatorial regimens to reverse drug resistance, as well as offer unprecedented targeting approaches that may help to more effectively treat a large proportion of solid tumours and their complications. Here, we highlight recent findings regarding various aspects of tumour mechanobiology in the clinical setting and discuss evidence-based perspectives of developing diagnostic/prognostic tools and therapeutic approaches that exploit tumour-TME physical associations.

The Force is Strong with This Epigenome: Chromatin Structure and Mechanobiology

All life forms sense and respond to mechanical stimuli. Throughout evolution, organisms develop diverse mechanosensing and mechanotransduction pathways, leading to fast and sustained mechanoresponses. Memory and plasticity characteristics of mechanoresponses are thought to be stored in the form of epigenetic modifications, including chromatin structure alterations. These mechanoresponses in the chromatin context share conserved principles across species, such as lateral inhibition during organogenesis and development. However, it remains unclear how mechanotransduction mechanisms alter chromatin structure for specific cellular functions, and if altered chromatin structure can mechanically affect the environment. In this review, we discuss how chromatin structure is altered by environmental forces via an outside-in pathway for cellular functions, and the emerging concept of how chromatin structure alterations can mechanically affect nuclear, cellular, and extracellular environments. This bidirectional mechanical feedback between chromatin of the cell and the environment can potentially have important physiological implications, such as in centromeric chromatin regulation of mechanobiology in mitosis, or in tumor-stroma interactions. Finally, we highlight the current challenges and open questions in the field and provide perspectives for future research.

NK Cells in Cancer: Mechanisms of Dysfunction and Therapeutic Potential

Natural killer cells (NK) are innate lymphocytes endowed with the ability to recognize and kill cancer cells. Consequently, adoptive transfer of autologous or allogeneic NK cells represents a novel opportunity in cancer treatment that is currently under clinical investigation. However, cancer renders NK cells dysfunctional, thus restraining the efficacy of cell therapies. Importantly, extensive effort has been employed to investigate the mechanisms that restrain NK cell anti-tumor function, and the results have offered forthcoming solutions to improve the efficiency of NK cell-based therapies. The present review will introduce the origin and features of NK cells, summarize the mechanisms of action and causes of dysfunction of NK cells in cancer, and frame NK cells in the tumoral microenvironment and in the context of immunotherapies. Finally, we will discuss therapeutic potential and current limitations of NK cell adoptive transfer in tumors.

The role of glycans in the mechanobiology of cancer

Although cancer is a genetic disease, physical changes such as stiffening of the extracellular matrix also commonly occur in cancer. Cancer cells sense and respond to extracellular matrix stiffening through the process of mechanotransduction. Cancer cell mechanotransduction can enhance cancer-promoting cell behaviors such as survival signaling, proliferation, and migration. Glycans, carbohydrate-based polymers, have recently emerged as important mediators and/or modulators of cancer cell mechanotransduction. Stiffer tumors are characterized by increased glycan content on cancer cells and their associated extracellular matrix. Here we review the role of cancer-associated glycans in coupled mechanical and biochemical alterations during cancer progression. We discuss the recent evidence on how increased expression of different glycans, in the form of glycoproteins and proteoglycans, contributes to both mechanical changes in tumors and corresponding cancer cell responses. We conclude with a summary of emerging tools that can be used to modify glycans for future studies in cancer mechanobiology.

NK cells are never alone: crosstalk and communication in tumour microenvironments

Immune escape is a hallmark of cancer. The dynamic and heterogeneous tumour microenvironment (TME) causes insufficient infiltration and poor efficacy of natural killer (NK) cell-based immunotherapy, which becomes a key factor triggering tumour progression. Understanding the crosstalk between NK cells and the TME provides new insights for optimising NK cell-based immunotherapy. Here, we present new advances in direct or indirect crosstalk between NK cells and 9 specialised TMEs, including immune, metabolic, innervated niche, mechanical, and microbial microenvironments, summarise TME-mediated mechanisms of NK cell function inhibition, and highlight potential targeted therapies for NK-TME crosstalk. Importantly, we discuss novel strategies to overcome the inhibitory TME and provide an attractive outlook for the future.

Cancer-Associated Adipocytes and Breast Cancer: Intertwining in the Tumor Microenvironment and Challenges for Cancer Therapy

Adipocytes are the main components in breast tissue, and cancer-associated adipocytes (CAAs) are one of the most important components in the tumor microenvironment of breast cancer (BC). Bidirectional regulation was found between CAAs and BC cells. BC facilitates the dedifferentiation of adjacent adipocytes to form CAAs with morphological and biological changes. CAAs increase the secretion of multiple cytokines and adipokines to promote the tumorigenesis, progression, and metastasis of BC by remodeling the extracellular matrix, changing aromatase expression, and metabolic reprogramming, and shaping the tumor immune microenvironment. CAAs are also associated with the therapeutic response of BC and provide potential targets in BC therapy. The present review provides a comprehensive description of the crosstalk between CAAs and BC and discusses the potential strategies to target CAAs to overcome BC treatment resistance.

Identifying key transcription factors and immune infiltration in non-small-cell lung cancer using weighted correlation network and Cox regression analyses

Introduction

Lung cancer is one of the most common cancers and a significant cause of cancer-related deaths. Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases. Therefore, it is crucial to identify effective diagnostic and therapeutic methods. In addition, transcription factors are essential for eukaryotic cells to regulate their gene expression, and aberrant expression transcription factors are an important step in the process of oncogenesis in NSCLC.

Methods

Differentially expressed transcription factors between NSCLC and normal tissues by analyzing mRNA profiling from The Cancer Genome Atlas (TCGA) database program were identified. Weighted correlation network analysis (WGCNA) and line plot of least absolute shrinkage and selection operator (LASSO) were performed to find prognosis-related transcription factors. The cellular functions of transcription factors were performed by 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, cell invasion assay in lung cancer cells.

Results

We identified 725 differentially expressed transcription factors between NSCLC and normal tissues. Three highly related modules for survival were discovered, and transcription factors highly associated with survival were obtained by using WGCNA. Then line plot of LASSO was applied to screen transcription factors related to prognosis and build a prognostic model. Consequently, SETDB2, SNAI3, SCML4, and ZNF540 were identified as prognosis-related transcription factors and validated in multiple databases. The low expression of these hub genes in NSCLC was associated with poor prognosis. The deletions of both SETDB2 and SNAI3 were found to promote proliferation, invasion, and stemness in lung cancer cells. Furthermore, there were significant differences in the proportions of 22 immune cells between the high- and low-score groups.

Discussion

Therefore, our study identified the transcription factors involved in regulating NSCLC, and we constructed a panel for the prediction of prognosis and immune infiltration to inform the clinical application of transcription factor analysis in the prevention and treatment of NSCLC.

Shear stress enhances anoikis resistance of cancer cells through ROS and NO suppressed degeneration of Caveolin-1

Circulating tumor cells (CTCs) acquire enhanced anti-anoikis abilities after experiencing flow shear stress in the circulatory system. Our previous study demonstrated that low shear stress (LSS) promotes anoikis resistance of human breast carcinoma cells via caveolin-1 (Cav-1)-dependent extrinsic and intrinsic apoptotic pathways. However, the underlying mechanism how LSS enhanced Cav-1 expression in suspended cancer cells remains unclear. Herein, we found that LSS induced redox signaling was involved in the regulation of Cav-1 level and anoikis resistance in suspension cultured cancer cells. Exposure of human breast carcinoma MDA-MB-231 cells to LSS (2 dyn/cm²) markedly induced ROS and ^•NO generation, which promoted the cell viability and reduced the cancer cell apoptosis. Furthermore, ROS and ^•NO scavenging inhibited the upregulation of Cav-1 by interfering ubiquitination, and suppressed the anoikis resistance of suspended tumor cells. These findings provide new insight into the mechanism by which LSS-stimulated ROS and ^•NO generation increases Cav-1 stabilization in suspended cancer cells through inhibition of ubiquitination and proteasomal degradation, which could be a potential target for therapy of metastatic tumors.