Lambda phage-based vaccine induces antitumor immunity in hepatocellular carcinoma

Phage based vaccine: A novel strategy in prevention and treatment

The vaccine was first developed in 1796 by a British physician, Edward Jenner, against the smallpox virus. This invention revolutionized medical science and saved lives around the world. The production of effective vaccines requires dominant immune epitopes to elicit a robust immune response. Thus, applying bacteriophages has attracted the attention of many researchers because of their advantages in vaccine design and development. Bacteriophages are not infectious to humans and are unlikely to bind to cellular receptors and activate signaling pathways. Phages could activate both cellular and humoral immunity, which is another goal of an effective vaccine design. Also, phages act as an effective adjuvant, along with the antigens, and induce a robust immune response. Phage-based vaccines can also be administered orally because of their stability in the gastrointestinal tract, in contrast to common vaccination routes, which are intradermal, subcutaneous, or intramuscular. This review presents the current improvements in phage-based vaccines and their applications as preventive or therapeutic vaccines.

Engineered Phage-Based Cancer Vaccines: Current Advances and Future Directions

Bacteriophages have emerged as versatile tools in the field of bioengineering, with enormous potential in tissue engineering, vaccine development, and immunotherapy. The genetic makeup of phages can be harnessed for the development of novel DNA vaccines and antigen display systems, as they can provide a highly organized and repetitive presentation of antigens to immune cells. Bacteriophages have opened new possibilities for the targeting of specific molecular determinants of cancer cells. Phages can be used as anticancer agents and carriers of imaging molecules and therapeutics. In this review, we explored the role of bacteriophages and bacteriophage engineering in targeted cancer therapy. The question of how the engineered bacteriophages can interact with the biological and immunological systems is emphasized to comprehend the underlying mechanism of phage use in cancer immunotherapy. The effectiveness of phage display technology in identifying high-affinity ligands for substrates, such as cancer cells and tumor-associated molecules, and the emerging field of phage engineering and its potential in the development of effective cancer treatments are discussed. We also highlight phage usage in clinical trials as well as the related patents. This review provides a new insight into engineered phage-based cancer vaccines.

A Recombinant RBD-Based Phage Vaccine Report: A Solution to the Prevention of New Diseases?

The safety, inherent immunogenicity, stability, and low-cost production of bacteriophages make them an ideal platform for vaccine development. Most vaccination strategies against COVID-19 have targeted the spike protein of SARS-CoV-2 to generate neutralizing antibodies. P1, a truncated RBD-derived spike protein, has been shown to induce virus-neutralizing antibodies in preclinical studies. In this study, we first investigated whether recombinant phages displaying P1 on the M13 major protein could immunize mice against COVID-19, and second, whether inoculation with 50 µg of purified P1 in addition to the recombinant phages would stimulate the immune systems of the animals. The results showed that the mice that received recombinant phages were immunized against the phage particles, but did not have anti-P1 IgG. In contrast, compared with the negative control, the group that received a combination of P1 protein and recombinant phage was immunized against the P1 protein. In both groups, CD4⁺ and CD8⁺ T cells appeared in the lung tissue. These results suggest that the number of antigens on the phage body plays a crucial role in stimulating the immune system against the bacteriophage, although it is immunogenic enough to function as a phage vaccine.

Disarm The Bacteria: What Temperate Phages Can Do

In the field of phage applications and clinical treatment, virulent phages have been in the spotlight whereas temperate phages received, relatively speaking, less attention. The fact that temperate phages often carry virulent or drug-resistant genes is a constant concern and drawback in temperate phage applications. However, temperate phages also play a role in bacterial regulation. This review elucidates the biological properties of temperate phages based on their life cycle and introduces the latest work on temperate phage applications, such as on host virulence reduction, biofilm degradation, genetic engineering and phage display. The versatile use of temperate phages coupled with their inherent properties, such as economy, ready accessibility, wide variety and host specificity, make temperate phages a solid candidate in tackling bacterial infections.

Bacteriophage-Mediated Cancer Gene Therapy

Bacteriophages have long been considered only as infectious agents that affect bacterial hosts. However, recent studies provide compelling evidence that these viruses are able to successfully interact with eukaryotic cells at the levels of the binding, entry and expression of their own genes. Currently, bacteriophages are widely used in various areas of biotechnology and medicine, but the most intriguing of them is cancer therapy. There are increasing studies confirming the efficacy and safety of using phage-based vectors as a systemic delivery vehicle of therapeutic genes and drugs in cancer therapy. Engineered bacteriophages, as well as eukaryotic viruses, demonstrate a much greater efficiency of transgene delivery and expression in cancer cells compared to non-viral gene transfer methods. At the same time, phage-based vectors, in contrast to eukaryotic viruses-based vectors, have no natural tropism to mammalian cells and, as a result, provide more selective delivery of therapeutic cargos to target cells. Moreover, numerous data indicate the presence of more complex molecular mechanisms of interaction between bacteriophages and eukaryotic cells, the further study of which is necessary both for the development of gene therapy methods and for understanding the cancer nature. In this review, we summarize the key results of research into aspects of phage-eukaryotic cell interaction and, in particular, the use of phage-based vectors for highly selective and effective systemic cancer gene therapy.

Modification of Regulatory T Cell Epitopes Promotes Effector T Cell Responses to Aspartyl/Asparaginyl β-Hydroxylase

Cancer is a leading cause of death worldwide. The search for innovative therapeutic approaches is a principal focus of medical research. Vaccine strategies targeting a number of tumor-associated antigens are currently being evaluated. To date, none have garnered significant success. Purportedly, an immunosuppressive tumor microenvironment and the accumulation of regulatory T cells contribute to a lack of tumor vaccine efficacy. Aspartyl/asparaginyl β-hydroxylase (ASPH), a promising therapeutic target, is overexpressed in a variety of malignant tumors but is expressed negligibly in normal tissues. Computer analysis predicted that ASPH expresses four peptide sequences (epitopes) capable of stimulating regulatory T cell activity. The abolition of these putative regulatory T cell epitopes increased the CD4+ and CD8+ effector T cell responses to monocyte-derived dendritic cells pulsed with a modified, epitope-depleted version of ASPH in an ex vivo human lymphoid tissue-equivalent coculture system while simultaneously decreasing the overall number of FoxP3+ regulatory T cells. These findings suggest that the efficacy of all new vaccine candidates would profit from screening and eliminating potential tolerogenic regulatory T cell epitopes.

Adaptive antitumor immune response stimulated by bio-nanoparticle based vaccine and checkpoint blockade

BACKGROUND

Interactions between tumor and microenvironment determine individual response to immunotherapy. Triple negative breast cancer (TNBC) and hepatocellular carcinoma (HCC) have exhibited suboptimal responses to immune checkpoint inhibitors (ICIs). Aspartate β-hydroxylase (ASPH), an oncofetal protein and tumor associated antigen (TAA), is a potential target for immunotherapy.

METHODS

Subcutaneous HCC and orthotopic TNBC murine models were established in immunocompetent BALB/c mice with injection of BNL-T3 and 4 T1 cells, respectively. Immunohistochemistry, immunofluorescence, H&E, flow cytometry, ELISA and in vitro cytotoxicity assays were performed.

RESULTS

The ASPH-MYC signaling cascade upregulates PD-L1 expression on breast and liver tumor cells. A bio-nanoparticle based λ phage vaccine targeting ASPH was administrated to mice harboring syngeneic HCC or TNBC tumors, either alone or in combination with PD-1 blockade. In control, autocrine chemokine ligand 13 (CXCL13)-C-X-C chemokine receptor type 5 (CXCR5) axis promoted tumor development and progression in HCC and TNBC. Interactions between PD-L1+ cancer cells and PD-1+ T cells resulted in T cell exhaustion and apoptosis, causing immune evasion of cancer cells. In contrast, combination therapy (Vaccine+PD-1 inhibitor) significantly suppressed primary hepatic or mammary tumor growth (with distant pulmonary metastases in TNBC). Adaptive immune responses were attributed to expansion of activated CD4+ T helper type 1 (Th1)/CD8+ cytotoxic T cells (CTLs) that displayed enhanced effector functions, and maturation of plasma cells that secreted high titers of ASPH-specific antibody. Combination therapy significantly reduced tumor infiltration of immunosuppressive CD4+/CD25+/FOXP3+ Tregs. When the PD-1/PD-L1 signal was inhibited, CXCL13 produced by ASPH+ cancer cells recruited CXCR5+/CD8+ T lymphocytes to tertiary lymphoid structures (TLSs), comprising effector and memory CTLs, T follicular helper cells, B cell germinal center, and follicular dendritic cells. TLSs facilitate activation and maturation of DCs and actively recruit immune subsets to tumor microenvironment. These CTLs secreted CXCL13 to recruit more CXCR5+ immune cells and to lyse CXCR5+ cancer cells. Upon combination treatment, formation of TLSs predicts sensitivity to ICI blockade. Combination therapy substantially prolonged overall survival of mice with HCC or TNBC.

CONCLUSIONS

Synergistic antitumor efficacy attributable to a λ phage vaccine specifically targeting ASPH, an ideal TAA, combined with ICIs, inhibits tumor growth and progression of TNBC and HCC.

Protein Cages: From Fundamentals to Advanced Applications

Proteins that self-assemble into polyhedral shell-like structures are useful molecular containers both in nature and in the laboratory. Here we review efforts to repurpose diverse protein cages, including viral capsids, ferritins, bacterial microcompartments, and designed capsules, as vaccines, drug delivery vehicles, targeted imaging agents, nanoreactors, templates for controlled materials synthesis, building blocks for higher-order architectures, and more. A deep understanding of the principles underlying the construction, function, and evolution of natural systems has been key to tailoring selective cargo encapsulation and interactions with both biological systems and synthetic materials through protein engineering and directed evolution. The ability to adapt and design increasingly sophisticated capsid structures and functions stands to benefit the fields of catalysis, materials science, and medicine.

Aspartate β-Hydroxylase (ASPH) Expression in Acute Myeloid Leukemia: A Potential Novel Therapeutic Target

Background

Aspartate β-hydroxylase (ASPH) is an embryonic transmembrane protein aberrantly upregulated in cancer cells, associated with malignant transformation and, in some reports, with poor clinical prognosis.

Objective

To report the expression patterns of ASPH in acute myeloid leukemia (AML).

Methods

Cell surface expression of ASPH was measured via 8-color multiparameter flow cytometry in 41 AML patient samples (31 bone marrow, 10 blood) using fluorescein isothiocyanate (FITC)-conjugated anti-ASPH antibody, SNS-622. A mean fluorescent intensity (MFI) of 10 was used as a cutoff for ASPH surface expression positivity. Data regarding patient and disease characteristics were collected.

Results

ASPH surface expression was found on AML blasts in 16 samples (39%). Higher ASPH expression was seen in myeloblasts of African American patients (p=0.02), but no correlation was found between ASPH expression and other patient or disease characteristics. No association was found between ASPH status and CR rate (p=0.53), EFS (p=0.87), or OS (p=0.17).

Conclusions

ASPH is expressed on blasts in approximately 40% of AML cases, and may serve as a new therapeutically targetable leukemia-associated antigen.

Bacteriophages as Solid Tumor Theragnostic Agents

Cancer, especially the solid tumor sub-set, poses considerable challenges to modern medicine owing to the unique physiological characteristics and substantial variations in each tumor's microenvironmental niche fingerprints. Though there are many treatment methods available to treat solid tumors, still a considerable loss of life happens, due to the limitation of treatment options and the outcomes of ineffective treatments. Cancer cells evolve with chemo- or radiation-treatment strategies and later show adaptive behavior, leading to failed treatment. These challenges demand tailored and individually apt personalized treatment methods. Bacteriophages (or phages) and phage-based theragnostic vectors are gaining attention in the field of modern cancer medicine, beyond their bactericidal ability. With the invention of the latest techniques to fine-tune phages, such as in the field of genetic engineering, synthetic assembly methods, phage display, and chemical modifications, noteworthy progress in phage vector research for safe cancer application has been realized, including use in pre-clinical studies. Herein, we discuss the distinct fingerprints of solid tumor physiology and the potential for bacteriophage vectors to exploit specific tumor features for improvised tumor theragnostic applications.

Bio-nanoparticle based therapeutic vaccine induces immunogenic response against triple negative breast cancer

Triple negative breast cancer (TNBC) is more aggressive and has a poorer prognosis than other sub-types of breast tumors. This study elucidates how aspartate beta-hydroxylase (ASPH) network promotes drug resistance, and immunotherapy targeting ASPH may improve the efficacy of Doxorubicin (DOX) therapy. An orthotopic model of breast cancer generated by 4T1 cells in immunocompetent mice was used to explore efficacy of immunotherapy in combination with DOX chemotherapy. We evaluated mRNA and protein expression in cultured tumor cells and tissue, as well as assessed cell proliferation, apoptosis, soluble factors/cytokine production, immune cell population diversity and function. We observed that ASPH expression enables TNBC cells to exhibit primary resistance to DOX induced single-/double-strand breaks (SSB/DSB) and enhanced proliferation and survival. Specific bio-nanoparticle based therapeutic vaccine (BNP-TV) promoted ASPH uptake by and maturation of DCs. This BNP-TV combined with DOX induces immunogenic cell death (ICD) in orthotopic xenograft tumors and significantly suppressed primary mammary tumor growth and distant multi-organ metastases. Immunogenic cell death induced by BNP-TV targeting ASPH combined with DOX provides opportunities to treat a highly resistant and metastatic form of breast cancer.

Targeted Intracellular Delivery of Trastuzumab Using Designer Phage Lambda Nanoparticles Alters Cellular Programs in Human Breast Cancer Cells

| Several diseases exhibit a high degree of heterogeneity and diverse reprogramming of cellular pathways. To address this complexity, additional strategies and technologies must be developed to define their scope and variability with the goal of improving current treatments. Nanomedicines derived from viruses are modular systems that can be easily adapted for combinatorial approaches, including imaging, biomarker targeting, and intracellular delivery of therapeutics. Here, we describe a "designer nanoparticle" system that can be rapidly engineered in a tunable and defined manner. Phage-like particles (PLPs) derived from bacteriophage lambda possess physiochemical properties compatible with pharmaceutical standards, and in vitro particle tracking and cell targeting are accomplished by simultaneous display of fluorescein-5-maleimide (F5M) and trastuzumab (Trz), respectively (Trz-PLPs). Trz-PLPs bind to the oncogenically active human epidermal growth factor receptor 2 (HER2) and are internalized by breast cancer cells of the HER2 overexpression subtype, but not by those lacking the HER2 amplification. Compared to treatment with Trz, robust internalization of Trz-PLPs results in higher intracellular concentrations of Trz, prolonged inhibition of cell growth, and modulated regulation of cellular programs associated with HER2 signaling, proliferation, metabolism, and protein synthesis. Given the implications to cancer pathogenesis and that dysregulated signaling and metabolism can lead to drug resistance and cancer cell survival, the present study identifies metabolic and proteomic liabilities that could be exploited by the PLP platform to enhance therapeutic efficacy. The lambda PLP system is robust and rapidly modifiable, which offers a platform that can be easily "tuned" for broad utility and tailored functionality.

Bacteriophages and the Immune System

Bacteriophages-viruses that infect bacteria-are abundant within our bodies, but their significance to human health is only beginning to be explored. Here, we synthesize what is currently known about our phageome and its interactions with the immune system. We first review how phages indirectly affect immunity via bacterial expression of phage-encoded proteins. We next review how phages directly influence innate immunity and bacterial clearance. Finally, we discuss adaptive immunity against phages and its implications for phage/bacterial interactions. In light of these data, we propose that our microbiome can be understood as an interconnected network of bacteria, bacteriophages, and human cells and that the stability of these tri-kingdom interactions may be important for maintaining our immunologic and metabolic health. Conversely, the disruption of this balance, through exposure to exogenous phages, microbial dysbiosis, or immune dysregulation, may contribute to disease. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Bacteriophages as Potential Tools for Use in Antimicrobial Therapy and Vaccine Development

The constantly growing number of people suffering from bacterial, viral, or fungal infections, parasitic diseases, and cancers prompts the search for innovative methods of disease prevention and treatment, especially based on vaccines and targeted therapy. An additional problem is the global threat to humanity resulting from the increasing resistance of bacteria to commonly used antibiotics. Conventional vaccines based on bacteria or viruses are common and are generally effective in preventing and controlling various infectious diseases in humans. However, there are problems with the stability of these vaccines, their transport, targeted delivery, safe use, and side effects. In this context, experimental phage therapy based on viruses replicating in bacterial cells currently offers a chance for a breakthrough in the treatment of bacterial infections. Phages are not infectious and pathogenic to eukaryotic cells and do not cause diseases in human body. Furthermore, bacterial viruses are sufficient immuno-stimulators with potential adjuvant abilities, easy to transport, and store. They can also be produced on a large scale with cost reduction. In recent years, they have also provided an ideal platform for the design and production of phage-based vaccines to induce protective host immune responses. The most promising in this group are phage-displayed vaccines, allowing for the display of immunogenic peptides or proteins on the phage surfaces, or phage DNA vaccines responsible for expression of target genes (encoding protective antigens) incorporated into the phage genome. Phage vaccines inducing the production of specific antibodies may in the future protect us against infectious diseases and constitute an effective immune tool to fight cancer. Moreover, personalized phage therapy can represent the greatest medical achievement that saves lives. This review demonstrates the latest advances and developments in the use of phage vaccines to prevent human infectious diseases; phage-based therapy, including clinical trials; and personalized treatment adapted to the patient's needs and the type of bacterial infection. It highlights the advantages and disadvantages of experimental phage therapy and, at the same time, indicates its great potential in the treatment of various diseases, especially those resistant to commonly used antibiotics. All the analyses performed look at the rich history and development of phage therapy over the past 100 years.

Phages in vaccine design and immunity; mechanisms and mysteries

Bacteriophages have attracted extensive interest in vaccine design. This includes the use of phage display technology to select antigens, the use of engineered phages displaying target antigens in vaccine formulations, and phage DNA vaccines. However, the development of these approaches is limited in part by uncertainty regarding the underlying mechanisms by which phages elicit immunity. This has stymied the clinical development of this technology. Here we review the immunology of phage vaccines and highlight the gaps in our knowledge regarding the underlying mechanisms. First, we review the basic biology of phages and their use in vaccines. Next we discuss what is known about the mechanisms of immunity against engineered phages and phage DNA. Finally, we highlight the gaps in our understanding regarding the immunogenicity of these preparations. We argue that mechanistic insight into the immunology of phage vaccines is essential for the further development and clinical utility of these technologies.

Diverse molecular functions of aspartate β‑hydroxylase in cancer (Review)

Aspartate/asparagine β-hydroxylase (AspH) is a type II transmembrane protein that catalyzes the post-translational hydroxylation of definite aspartyl and asparaginyl residues in epidermal growth factor-like domains of substrates. In the last few decades, accumulating evidence has indicated that AspH expression is upregulated in numerous types of human malignant cancer and is associated with poor survival and prognosis. The AspH protein aggregates on the surface of tumor cells, which contributes to inducing tumor cell migration, infiltration and metastasis. However, small-molecule inhibitors targeting hydroxylase activity can markedly block these processes, both in vitro and in vivo. Immunization of tumor-bearing mice with a phage vaccine fused with the AspH protein can substantially delay tumor growth and progression. Additionally, AspH antigen-specific CD4⁺ and CD8⁺ T cells were identified in the spleen of tumor-bearing mice. Therefore, these agents may be used as novel strategies for cancer treatment. The present review summarizes the current progress on the underlying mechanisms of AspH expression in cancer development.

Bacteriophage-Based Vaccines: A Potent Approach for Antigen Delivery

Vaccines are considered one of the most important bioproducts in medicine. Since the development of the smallpox vaccine in 1796, several types of vaccines for many diseases have been created. However, some vaccines have shown limitations as high cost and low immune responses. In that regard, bacteriophages have been proposed as an attractive alternative for the development of more cost-effective vaccines. Phage-displayed vaccines consists in the expression of antigens on the phage surface. This approach takes advantage of inherent properties of these particles such as their adjuvant capacity, economic production and high stability, among others. To date, three types of phage-based vaccines have been developed: phage-displayed, phage DNA and hybrid phage-DNA vaccines. Typically, phage display technology has been used for the identification of new and protective epitopes, mimotopes and antigens. In this context, phage particles represent a versatile, effective and promising alternative for the development of more effective vaccine delivery systems which should be highly exploited in the future. This review describes current advances in the development of bacteriophage-based vaccines, with special attention to vaccine delivery strategies. Moreover, the immunological aspects of phage-based vaccines, as well as the applications of phage display for vaccine development, are explored. Finally, important challenges and the future of phage-bases vaccines are discussed.

Aspartate β-hydroxylase as a target for cancer therapy

As metastasis is a major cause of death in cancer patients, new anti-metastatic strategies are needed to improve cancer therapy outcomes. Numerous pathways have been shown to contribute to migration and invasion of malignant tumors. Aspartate β-hydroxylase (ASPH) is a key player in the malignant transformation of solid tumors by enhancing cell proliferation, migration, and invasion. ASPH also promotes tumor growth by stimulation of angiogenesis and immunosuppression. These effects are mainly achieved via the activation of Notch and SRC signaling pathways. ASPH expression is upregulated by growth factors and hypoxia in different human tumors and its inactivation may have broad clinical impact. Therefore, small molecule inhibitors of ASPH enzymatic activity have been developed and their anti-metastatic effect confirmed in preclinical mouse models. ASPH can also be targeted by monoclonal antibodies and has also been used as a tumor-associated antigen to induce both cluster of differentiation (CD) 8+ and CD4+ T cells in mice. The PAN-301-1 vaccine against ASPH has already been tested in a phase 1 clinical trial in patients with prostate cancer. In summary, ASPH is a promising target for anti-tumor and anti-metastatic therapy based on inactivation of catalytic activity and/or immunotherapy.

Aspartate/asparagine-β-hydroxylase: a high-throughput mass spectrometric assay for discovery of small molecule inhibitors

The human 2-oxoglutarate dependent oxygenase aspartate/asparagine-β-hydroxylase (AspH) catalyses the hydroxylation of Asp/Asn-residues in epidermal growth factor-like domains (EGFDs). AspH is upregulated on the surface of malign cancer cells; increased AspH levels correlate with tumour invasiveness. Due to a lack of efficient assays to monitor the activity of isolated AspH, there are few reports of studies aimed at identifying small-molecule AspH inhibitors. Recently, it was reported that AspH substrates have a non-canonical EGFD disulfide pattern. Here we report that a stable synthetic thioether mimic of AspH substrates can be employed in solid phase extraction mass spectrometry based high-throughput AspH inhibition assays which are of excellent robustness, as indicated by high Z'-factors and good signal-to-noise/background ratios. The AspH inhibition assay was applied to screen approximately 1500 bioactive small-molecules, including natural products and active pharmaceutical ingredients of approved human therapeutics. Potent AspH inhibitors were identified from both compound classes. Our AspH inhibition assay should enable the development of potent and selective small-molecule AspH inhibitors and contribute towards the development of safer inhibitors for other 2OG oxygenases, e.g. screens of the hypoxia-inducible factor prolyl-hydroxylase inhibitors revealed that vadadustat inhibits AspH with moderate potency.

Phage display as a tool for vaccine and immunotherapy development

Bacteriophages, or phages, are viruses that specifically infect bacteria and coopt the cellular machinery to create more phage proteins, eventually resulting in the release of new phage particles. Phages are heavily utilized in bioengineering for applications ranging from tissue engineering scaffolds to immune signal delivery. Of specific interest to vaccines and immunotherapies, phages have demonstrated an ability to activate both the innate and adaptive immune systems. The genome of these viral particles can be harnessed for DNA vaccination, or the surface proteins can be exploited for antigen display. More specifically, genes that encode an antigen of interest can be spliced into the phage genome, allowing antigenic proteins or peptides to be displayed by fusion to phage capsid proteins. Phages therefore present antigens to immune cells in a highly ordered and repetitive manner. This review discusses the use of phage with adjuvanting activity as antigen delivery vehicles for vaccination against infectious disease and cancer.

Blockage of TGF-α Induced by Spherical Silica Nanoparticles Inhibits Epithelial-Mesenchymal Transition and Proliferation of Human Lung Epithelial Cells

Background. Xuanwei City in Yunnan province has been one of the towns with highest lung cancer mortality in China. The high content of amorphous silica in the bituminous coal from Xuanwei of Yunnan is mainly present as irregular and spherical silica nanoparticles (SiNPs). It has been reported that silica nanoparticles in bituminous coal correlated with the high incidence of lung cancer in Xuanwei. To explore the role and mechanism of SiNPs in the tumorigenesis of lung cancer in Xuanwei, human mononuclear cells (THP-1) and human bronchial epithelial cells (BEAS-2B) were cocultured in a transwell chamber. Combined with Benzo[a]pyrene-7, 8-dihydrodiol-9, and 10-epoxide (BPDE), SiNPs could significantly promote the proliferation and Epithelial-Mesenchymal Transition (EMT) and inhibit apoptosis of BEAS-2B cells and induce the release of TGF-α from THP-1 cells. After neutralizing TGF-α with antibody, the proliferation and EMT were decreased and enhanced apoptosis of BEAS-2B cells. Furthermore, the results showed that TGF-α in the sera of patients with lung adenocarcinoma in Xuanwei were significantly higher than in patients with benign pulmonary lesions in Xuanwei and those with lung adenocarcinoma in outside of Xuanwei of Yunnan. Taken together, our study found that SiNPs promoted the proliferation and EMT of BEAS-2B cells by inducing the release of TGF-α from THP-1 cells.

Spherical silica nanoparticles promote malignant transformation of BEAS-2B cells by stromal cell-derived factor-1α (SDF-1α)

Objective

This study aimed to examine the role of spherical silica nanoparticles (SiNPs) on human bronchial epithelial (BEAS-2B) cells through inflammation.

Methods

Human mononuclear (THP-1) cells and BEAS-2B cells were co-cultured in transwell chambers and treated with 800 mmol/L benzo[a]pyrene-7, 8-dihydrodiol-9, 10-epoxide (BPDE) and 12.5 µg/mL SiNPs for 24 hours. For controls, cells were treated with BPDE alone. Subcutaneous tumorigenicity and epithelial-mesenchymal transition (EMT) of BEAS-2B cells were measured. The cells were blocked with a stromal cell-derived factor-1α (SDF-1α)-specific antibody. EMT was analyzed in cells treated with 800 mmol/L BPDE and 12.5 µg/mL SiNPs relative to matched control cells and xenografts in vivo. Serum SDF-1α levels were measured in 23 patients with lung adenocarcinoma in Xuanwei, in 25 with lung adenocarcinoma outside Xuanwei, and in 22 with benign pulmonary lesions in Xuanwei.

Results

SiNPs significantly promoted tumorigenesis and EMT, induced the release of SDF-1α, and activated AKT (ser473) in BEAS-2B cells. EMT and phosphorylated AKT (ser473) and glycogen synthase kinase-3β levels were decreased when blocked by SDF-1α antibody in BEAS-2B cells. SDF-1α was mainly secreted by THP-1 cells.

Conclusion

SiNPs combined with BPDE promote EMT of BEAS-2B cells via the AKT pathway by inducing release of SDF-1α from THP-1 cells.