Project description:Treatment for metastatic cancer is a great challenge throughout the world. Commonly, directed inhibition of extracellular matrix metalloproteinases (MMPs) secreted by cancer cells can reduce metastasis. Here, a novel nanoplatform (HPMC NPs) assembled from hyaluronic acid (HA)-paclitaxel (PTX) prodrug and marimastat (MATT)/β-casein (CN) complexes was established to cure a 4T1 metastatic cancer model via targeting CD44 and intracellular, rather than extracellular, MMPs. Methods: HPMC NPs were prepared by assembling the complexes and prodrug under ultrasonic treatment, which the interaction between them was evaluated by förster resonance energy transfer, circular dichroism and fluorescence spectra. The developed nanoplatform was characterized via dynamic light scattering and transmission electron microscopy, and was evaluated in terms of MMP-sensitive release and stability. Subsequently, the cellular uptake, trafficking, and in vitro invasion were studied by flow cytometry, confocal laser microscopy and transwell assay. MMP expression and activity was determined by western blotting and gelatin zymography. Finally, the studies of biodistribution and antitumor efficacy in vivo were performed in a mouse 4T1 tumor breast model, followed by in vivo safety study in normal mouse. Results: The interaction between the prodrug and complexes is strong with a high affinity, resulting in the assembly of these two components into hybrid nanoparticles (250 nm). Compared with extracellular incubation with MATT, HPMC NP treatment markedly reduced the expression (100%) and activity (50%) of MMPs in 4T1 cells and in the tumor. HPMC NPs exhibited 1.4-fold tumor accumulation, inhibited tumor-growth by >8-fold in volume with efficient apoptosis and proliferation, and suppressed metastasis (>5-fold) and angiogenesis (>3-fold). Overall, HPMC NPs were efficient in metastatic cancer therapy. Conclusions: According to the assembly of polymer prodrug and protein-drug complexes, this study offers a new strategy for constructing nanoparticles for targeted drug delivery, biomedical imaging, and combinatorial treatment. Importantly, via inhibition of intracellular MMPs, metastasis and angiogenesis can be potently blocked, benefiting the rational design of nanomedicine for cancer treatment.
Project description:Bacteria were first detected in human tumors more than 100 years ago, but the characterization of the tumor microbiome has remained challenging because of its low biomass. We undertook a comprehensive analysis of the tumor microbiome, studying 1526 tumors and their adjacent normal tissues across seven cancer types, including breast, lung, ovary, pancreas, melanoma, bone, and brain tumors. We found that each tumor type has a distinct microbiome composition and that breast cancer has a particularly rich and diverse microbiome. The intratumor bacteria are mostly intracellular and are present in both cancer and immune cells. We also noted correlations between intratumor bacteria or their predicted functions with tumor types and subtypes, patients' smoking status, and the response to immunotherapy.
Project description:As a critical machinery for rapid pathogen removal, resident memory T cells (TRMs) are locally generated after the initial encounter. However, their development accompanying tumorigenesis remains elusive. Using a murine breast cancer model, we show that TRMs develop in the tumor, the contralateral mammary mucosa, and the pre-metastatic lung. Single-cell RNA sequencing of TRMs reveals two phenotypically distinct populations representing their active versus quiescent phases. These TRMs in different tissue compartments share the same TCR clonotypes and transcriptomes with a subset of intratumoral effector/effector memory T cells (TEff/EMs), indicating their developmental ontogeny. Furthermore, CXCL16 is highly produced by tumor cells and CXCR6- TEff/EMs are the major subset preferentially egressing the tumor to form distant TRMs. Functionally, releasing CXCR6 retention in the primary tumor amplifies tumor-derived TRMs in the lung and leads to superior protection against metastases. This immunologic fortification suggests a potential strategy to prevent metastasis in clinical oncology.
Project description:The central, mortality-associated hallmark of cancer is the process of metastasis. It is increasingly recognized that bacteria influence multiple facets of cancer progression, but the extent to which tumor microenvironment-associated bacteria control metastasis in cancer is poorly understood. To identify tumor-associated bacteria and their role in metastasis, we utilized established murine models of non-metastatic and metastatic breast tumors to identify bacteria capable of driving metastatic disease. We found several species of the Bacillus genus that were unique to metastatic tumors, and found that breast tumor cells cultured with a Bacillus bacterium isolated from metastatic tumors, Bacillus thermoamylovorans, produced nearly 3× the metastatic burden as control cells or cells cultured with bacteria from non-metastatic breast tumors. We then performed targeted metabolomics on tumor cells cultured with different bacterial species and found that B. thermoamylovorans differentially regulated tumor cell metabolite profiles compared to bacteria isolated from non-metastatic tumors. Using these bacteria, we performed de novo sequencing and tested for the presence of genes that were unique to the bacterium isolated from metastatic tumors in a patient population to provide a proof-of-concept for identifying how specific bacterial functions are associated with the metastatic process in cancer independent of bacterial species. Together, our data directly demonstrate the ability of specific bacteria to promote metastasis through interaction with cancer cells.ImportanceMetastasis is a major barrier to long-term survival for cancer patients, and therapeutic options for patients with aggressive, metastatic forms of breast cancer remain limited. It is therefore critical to understand the differences between non-metastatic and metastatic disease to identify potential methods for slowing or even stopping metastasis. In this work, we identify a bacterial species present with metastatic breast tumors capable of increasing the metastatic capabilities of tumor cells. We isolated and sequenced this bacteria, as well as a control species which failed to promote metastasis, and identified specific bacterial genes that were unique to the metastasis-promoting species. We tested for the presence of these bacterial genes in patient tumor samples and found they were more likely to be associated with mortality. We also identified enrichment of specific bacterial functions, providing insight into possible sources of bacteria-driven increases in the metastatic potential of multiple cancer types.
Project description:Specific bacteria, including Fusobacterium nucleatum, Streptococcus sanguis, Enterococcus faecalis, and Staphylococcus xylosus, have been identified as contributors to breast cancer metastasis. Due to limitations such as lack of selectivity, traditional antibiotic therapies face obstacles in eliminating intratumoral bacteria. Herein, this work proposes the use of therapeutic vaccines to selectively target and eliminate harmful bacteria within tumors. A multivalent vaccine encapsulating both insoluble and soluble bacterial antigens was developed, addressing the shortcomings of traditional antibacterial vaccines by balancing broad antigen coverage with effective immune activation. This vaccine induces robust downstream immune responses to eliminate F. nucleatum, S. sanguis, E. faecalis, and S. xylosus, demonstrating notable therapeutic and preventive efficacy in bacteria-induced cancer metastasis models. Unexpectedly, vaccinated infected mice showed even slower tumor metastasis than uninfected mice. Overall, this study validates the potential of nanovaccines in modulating the intratumoral microbiome for tumor therapy and highlights tumor-associated bacterial infections as potential promising antitumor targets.
Project description:Intracellular radical polymerizations allow for the direct bioorthogonal synthesis of various synthetic polymers within living cells, thereby providing a pathway to polymer-modified cells or the fermentative production of polymers. Here, we show that Escherichia coli cells can initiate the polymerization of various acrylamide, acrylic, and methacrylic monomers through an atom transfer radical reaction triggered by the activity of naturally occurring biomolecules within the bacterial cells. Intracellular radical polymerizations were confirmed by nuclear magnetic resonance spectroscopy, gel permeation chromatography of polymers extracted from the cells, and fluorescence labeling of the polymer directly inside the cells. The effect of polymerization on cell behavior and the response of the cells to polymerization was investigated through fluorescence microscopy and flow cytometry techniques, as well as metabolic and membrane integrity assays. The polymer synthesis and resulting products are cell-compatible, as indicated by the high viability of the polymerized cells. In cellulo synthesis of synthetic polymers containing fluorescent dyes was also achieved. These results not only enhance our understanding of the untapped potential of bacterial cells as living catalysts for polymer production but also reveal intracellular polymerization based on atom transfer radical polymerization initiators as a bioorthogonal tool for cell engineering and synthetic biology.
Project description:Peptidoglycan is the predominant stress-bearing structure in the cell envelope of most bacteria, and also a potent stimulator of the eukaryotic immune system. Obligate intracellular bacteria replicate exclusively within the interior of living cells, an osmotically protected niche. Under these conditions peptidoglycan is not necessarily needed to maintain the integrity of the bacterial cell. Moreover, the presence of peptidoglycan puts bacteria at risk of detection and destruction by host peptidoglycan recognition factors and downstream effectors. This has resulted in a selective pressure and opportunity to reduce the levels of peptidoglycan. In this review we have analysed the occurrence of genes involved in peptidoglycan metabolism across the major obligate intracellular bacterial species. From this comparative analysis, we have identified a group of predicted 'peptidoglycan-intermediate' organisms that includes the Chlamydiae, Orientia tsutsugamushi, Wolbachia and Anaplasma marginale. This grouping is likely to reflect biological differences in their infection cycle compared with peptidoglycan-negative obligate intracellular bacteria such as Ehrlichia and Anaplasma phagocytophilum, as well as obligate intracellular bacteria with classical peptidoglycan such as Coxiella, Buchnera and members of the Rickettsia genus. The signature gene set of the peptidoglycan-intermediate group reveals insights into minimal enzymatic requirements for building a peptidoglycan-like sacculus and/or division septum.
Project description:Cancer-associated fibroblasts (CAFs) are the most abundant cells in the tumor microenvironment. Crosstalk between tumor cells and CAFs contributes to tumor survival in most epithelial cancers. Recently, utilizing gastrointestinal stromal tumor (GIST) as a model for sarcomas, we identified paracrine networks by which CAFs promote tumor progression and metastasis. However, the mechanisms by which CAFs arise in sarcomas remain unclear. Here, RNA sequencing analysis revealed that transforming growth factor-β1 (TGF-β1) is highly expressed in both tumor cells and CAFs. To determine the functional role of TGF-β1, we treated normal gastric fibroblasts (GFs) with recombinant TGF-β1, which caused the GFs to adopt a more stellate morphology, as well as increased the mRNA expression of CAF-mediated genes (CCL2, RAB3B, and TNC) and genes encoding fibroblast growth factors (FGFs). Moreover, while either GIST or CAF conditioned media enhanced the transition from GFs to CAFs, a TGF-β1-blocking antibody attenuated this effect. Transwell migration assays revealed that the TGF-β1-mediated transition from GFs to CAFs enhanced tumor cell migration. This migratory effect was abrogated by an anti-TGF-β1 antibody, suggesting that TGF-β1 secreted from GIST cells or CAFs is associated with GIST migration via GF-to-CAF transition. In addition, the murine spleen-to-liver metastasis model showed that GF pre-treated with TGF-β1 promoted GIST metastasis. Collectively, these findings reveal unappreciated crosstalk among tumor cells, CAFs, and normal resident fibroblasts in the stroma of sarcomas, which enhances a GF-to-CAF transition associated with tumor migration and metastasis.
Project description:BackgroundIt is still under debate that whether stage IV colorectal cancer patients with unresectable metastasis can benefit from primary tumor resection, especially for asymptomatic colorectal cancer patients. Retrospective studies have shown controversial results concerning the benefit from surgery. This retrospective study aims to evaluate whether the site of primary tumor is a predictor of palliative resection in asymptomatic stage IV colorectal cancer patients.MethodsOne hundred ninety-four patients with unresectable metastatic colorectal cancer were selected from Sun Yat-sen University Cancer Center Database in the period between January 2007 and December 2013. All information was carefully reviewed and collected, including the treatment, age, sex, carcinoembryonic antigen, site of tumor, histology, cancer antigen 199, number of liver metastases, and largest diameter of liver metastasis. The univariate and multivariate analyses were used to detect the relationship between primary tumor resection and overall survival of unresectable stage IV colorectal cancer patients.ResultsOne hundred twenty-five received palliative resection, and 69 received only chemotherapy. Multivariate analysis indicated that primary tumor site was one of the independent factors (RR 0.569, P = 0.007) that influenced overall survival. For left-side colon cancer patients, primary tumor resection prolonged the median overall survival time for 8 months (palliative resection vs. no palliative resection: 22 vs. 14 months, P = 0.009); however, for right-side colon cancer patients, palliative resection showed no benefit (12 vs. 10 months, P = 0.910).ConclusionsThis study showed that left-side colon cancer patients might benefit from the primary tumor resection in terms of overall survival. This result should be further explored in a prospective study.
Project description:Natural and artificial cells are two common chassis in synthetic biology. Natural cells can perform complex tasks through synthetic genetic constructs, but their autonomous replication often causes safety concerns for biomedical applications. In contrast, artificial cells based on nonreplicating materials, albeit possessing reduced biochemical complexity, provide more defined and controllable functions. Here, for the first time, the authors create hybrid material-cell entities termed Cyborg Cells. To create Cyborg Cells, a synthetic polymer network is assembled inside each bacterium, rendering them incapable of dividing. Cyborg Cells preserve essential functions, including cellular metabolism, motility, protein synthesis, and compatibility with genetic circuits. Cyborg Cells also acquire new abilities to resist stressors that otherwise kill natural cells. Finally, the authors demonstrate the therapeutic potential by showing invasion into cancer cells. This work establishes a new paradigm in cellular bioengineering by exploiting a combination of intracellular man-made polymers and their interaction with the protein networks of living cells.