The apoptotic impact of nisin as a potent bacteriocin on the colon cancer cells

Opportunities and challenges of RiPP-based therapeutics

Covering: up to 2024Ribosomally synthesised and post-translationally modified peptides (RiPPs) comprise a substantial group of peptide natural products exhibiting noteworthy bioactivities ranging from antiinfective to anticancer and analgesic effects. Furthermore, RiPP biosynthetic pathways represent promising production routes for complex peptide drugs, and the RiPP technology is well-suited for peptide engineering to produce derivatives with specific functions. Thus, RiPP natural products possess features that render them potentially ideal candidates for drug discovery and development. Nonetheless, only a small number of RiPP-derived compounds have successfully reached the market thus far. This review initially outlines the therapeutic opportunities that RiPP-based compounds can offer, whilst subsequently discussing the limitations that require resolution in order to fully exploit the potential of RiPPs towards the development of innovative drugs.

Label-Free Monitoring of Coculture System Dynamics: Probing Probiotic and Cancer Cell Interactions via Infrared Spectroscopic Imaging

Evaluating the dynamic interaction of microorganisms and mammalian cells is challenging due to the lack of suitable platforms for examining interspecies interactions in biologically relevant coculture conditions. In this work, we demonstrate the interaction between probiotic bacteria (Lactococcus lactis and Escherichia coli) and A498 human cancer cells in vitro, utilizing a hydrogel-based platform in a label-free manner by infrared spectroscopy. The L. lactis strain recapitulated in the compartment system secretes polypeptide molecules such as nisin, which has been reported to trigger cell apoptosis. We propose a mid-infrared (IR) spectroscopic imaging approach to monitor the variation of biological components utilizing kidney cells (A498) as a model system cocultured with bacteria. We characterized the biochemical composition (i.e., nucleic acids, protein secondary structures, and lipid conformations) label-free using an unbiased measurement. Several IR spectral features, including unsaturated fatty acids, β-turns in protein, and nucleic acids, were utilized to predict cellular response. These features were then applied to establish a quantitative relationship through a multivariate regression model to predict cellular dynamics in the coculture system to assess the effect of nisin on A498 kidney cancer cells cocultured with bacteria. Overall, our study sheds light on the potential of using IR spectroscopic imaging as a label-free tool to monitor complex microbe-host cell interactions in biological systems. This integration will enable mechanistic studies of interspecies interactions with insights into their underlying physiological processes.

Zein-based nisin-loaded electrospun nanofibers as active packaging mats for control of Listeria monocytogenes on peach

Zein-based nanofibers (NFs) functionalized with nisin (NS), reinforced with montmorillonite nanoclay (nMMT) were fabricated by uniaxial electrospinning (ES) for the first time to preserve yellow peach. Spinnability/viscosity/conductivity optimizations generated porous (95.09%), bead-free, ultrathin (119 nm) NFs of low hydrophobicity (26.05°). Glutaraldehyde (GTA) crosslinking fostered positive outcomes of tensile strength (1.23 MPa), elongation (5.0%), hydrophobicity (99.46°), surface area (201.38 m2.g-1), pore size (2.88 nm), thermal stability (Tmax = 342 °C), antioxidant/cytotoxic activities in optimized NFs that released NS sustainably according to Korsmeyer-Peppas model indicating a Fickian diffusion mechanism with R2 = 0.9587. The novel NFs inhibited growth of Listeria monocytogenes/aerobic mesophilic populations in peach after 4 days of abusive storage, evincing their robustness in food contact applications. Simultaneously, quality parameters (moisture/texture/browning/total soluble solids/pH) and peach physical appearance were maintained for up to 8 days, endorsing the practical value of zein-based NFs as a non-thermal postharvest intervention for prolonging fruits storage life.

Two Recombinant Bacteriocins, Rhamnosin and Lysostaphin, Show Synergistic Anticancer Activity Against Gemcitabine-Resistant Cholangiocarcinoma Cell Lines

Cholangiocarcinoma (CCA), a bile duct cancer with a high mortality rate, has a poor prognosis due to its highly invasive and drug-resistant phenotypes. More effective and selective therapies are urgently needed. Bacteriocins are broad-spectrum antimicrobial peptides/proteins produced by bacterial strains to compete with other bacteria. Recent studies have reported that bacteriocins exhibit anticancer properties against various cancer cell lines with minimal toxicity toward normal cells. In this study, two types of recombinant bacteriocins, rhamnosin from probiotic Lacticaseibacillus rhamnosus and lysostaphin from Staphylococcus simulans, were highly produced in Escherichia coli and subsequently purified via immobilized-Ni2+ affinity chromatography. When their anticancer activity was investigated against CCA cell lines, both rhamnosin and lysostaphin were found capable of inhibiting the growth of CCA cell lines in a dose-dependent fashion but were less toxic toward a normal cholangiocyte cell line. Rhamnosin and lysostaphin as single treatments could suppress the growth of gemcitabine-resistant cell lines to the same extent as or more than they suppressed the parental counterparts. A combination of both bacteriocins more strongly inhibited growth and enhanced cell apoptosis in both parental and gemcitabine-resistant cells partly through the increased expression of the proapoptotic genes BAX, and caspase-3, -8, and -9. In conclusion, this is the first report to demonstrate an anticancer property of rhamnosin and lysostaphin. Using these bacteriocins as single agents or in combination would be effective against drug-resistant CCA.

Friend or Foe: Exploring the Relationship between the Gut Microbiota and the Pathogenesis and Treatment of Digestive Cancers

Digestive cancers are among the leading causes of cancer death in the world. However, the mechanisms of cancer development and progression are not fully understood. Accumulating evidence in recent years pointing to the bidirectional interactions between gut dysbiosis and the development of a specific type of gastrointestinal cancer is shedding light on the importance of this "unseen organ"-the microbiota. This review focuses on the local role of the gut microbiota imbalance in different digestive tract organs and annexes related to the carcinogenic mechanisms. Microbiota modulation, either by probiotic administration or by dietary changes, plays an important role in the future therapies of various digestive cancers.

Bacteriocins: potentials and prospects in health and agrifood systems

Bacteriocins are highly diverse, abundant, and heterogeneous antimicrobial peptides that are ribosomally synthesized by bacteria and archaea. Since their discovery about a century ago, there has been a growing interest in bacteriocin research and applications. This is mainly due to their high antimicrobial properties, narrow or broad spectrum of activity, specificity, low cytotoxicity, and stability. Though initially used to improve food quality and safety, bacteriocins are now globally exploited for innovative applications in human, animal, and food systems as sustainable alternatives to antibiotics. Bacteriocins have the potential to beneficially modulate microbiota, providing viable microbiome-based solutions for the treatment, management, and non-invasive bio-diagnosis of infectious and non-infectious diseases. The use of bacteriocins holds great promise in the modulation of food microbiomes, antimicrobial food packaging, bio-sanitizers and antibiofilm, pre/post-harvest biocontrol, functional food, growth promotion, and sustainable aquaculture. This can undoubtedly improve food security, safety, and quality globally. This review highlights the current trends in bacteriocin research, especially the increasing research outputs and funding, which we believe may proportionate the soaring global interest in bacteriocins. The use of cutting-edge technologies, such as bioengineering, can further enhance the exploitation of bacteriocins for innovative applications in human, animal, and food systems.

The Gut Connection: Exploring the Possibility of Implementing Gut Microbial Metabolites in Lymphoma Treatment

Recent research has implicated the gut microbiota in the development of lymphoma. Dysbiosis of the gut microbial community can disrupt the production of gut microbial metabolites, thereby impacting host physiology and potentially contributing to lymphoma. Dysbiosis-driven release of gut microbial metabolites such as lipopolysaccharides can promote chronic inflammation, potentially elevating the risk of lymphoma. In contrast, gut microbial metabolites, such as short-chain fatty acids, have shown promise in preclinical studies by promoting regulatory T-cell function, suppressing inflammation, and potentially preventing lymphoma. Another metabolite, urolithin A, exhibited immunomodulatory and antiproliferative properties against lymphoma cell lines in vitro. While research on the role of gut microbial metabolites in lymphoma is limited, this article emphasizes the need to comprehend their significance, including therapeutic applications, molecular mechanisms of action, and interactions with standard chemotherapies. The article also suggests promising directions for future research in this emerging field of connection between lymphoma and gut microbiome.

Ribosomally synthesized bacteriocins of lactic acid bacteria: Simplicity yet having wide potentials - A review

Bacteriocins are ribosomally made bacterial peptides that have outstanding contributions in the field of food industry, as biopreservatives, and promising potentials in the medical field for improving human and animal health. Bacteriocins have many advantages over antibiotics such as being primary metabolites with relatively simpler biosynthetic mechanisms, which made their bioengineering for activity or specificity improving purposes much easier. Also, bacteriocins are degraded by proteolytic enzymes and do not stay in environment, which reduce chances of developing resistance. Bacteriocins can improve activity of some antibiotics, and some bacteriocins show potency against multidrug-resistant bacteria. Moreover, some potent bacteriocins have antiviral, antifungal, and antiprotozoal (antileishmanial) activities. On the other hand, bacteriocins have been introduced into the treatment of some ulcers and types of cancer. These potentials make bacteriocins attract extra attention as promising biotechnological tool. Hence, the history, characteristics, and classification of bacteriocins are described in this review. Furthermore, the main difference between bacteriocins and other antimicrobial peptides is clarified. Also, bacteriocins biosynthesis and identified modes of action are elucidated. Additionally, current and potential applications of bacteriocins in food and medical fields are highlighted. Finally, future perspectives concerning studying bacteriocins and their applications are discussed.

Bacteriocins: Curial guardians of gastrointestinal tract

The human gastrointestinal (GI) tract microbiome secretes various metabolites that play pivotal roles in maintaining host physiological balance and influencing disease progression. Among these metabolites, bacteriocins-small, heat-stable peptides synthesized by ribosomes-are notably prevalent in the GI region. Their multifaceted benefits have garnered significant interest in the scientific community. This review comprehensively explores the methods for mining bacteriocins (traditional separation and purification, bioinformatics, and artificial intelligence), their effects on the stomach and intestines, and their complex bioactive mechanisms. These mechanisms include flora regulation, biological barrier restoration, and intervention in epithelial cell pathways. By detailing each well-documented bacteriocin, we reveal the diverse ways in which bacteriocins interact with the GI environment. Moreover, the future research direction is prospected. By further studying the function and interaction of intestinal bacteriocins, we can discover new pharmacological targets and develop drugs targeting intestinal bacteriocins to regulate and improve human health. It provides innovative ideas and infinite possibilities for further exploration, development, and utilization of bacteriocins. The inevitable fact is that the continuously exploration of bacteriocins is sure to bring the promising future for demic GI health understanding and interference strategy.

Effects of dietary Nisin on growth performance, immune function, and gut health of broilers challenged by Clostridium perfringens

Nisin (Ni) is a polypeptide bacteriocin produced by lactic streptococci (probiotics) that can inhibit the majority of gram-positive bacteria, and improve the growth performance of broilers, and exert antioxidative and anti-inflammatory properties. The present study investigated the potential preventive effect of Nisin on necrotic enteritis induced by Clostridium perfringens (Cp) challenge. A total of 288 Arbor Acres broiler chickens of 1-d-olds were allocated using 2 × 2 factorial arrangement into four groups with six replicates (12 chickens per replicate), including: (1) control group (Con, basal diet), (2) Cp challenge group (Cp, basal diet + 1.0 × 108 CFU/mL Cp), (3) Ni group (Ni, basal diet + 100 mg/kg Ni), and (4) Ni + Cp group (Ni + Cp, basal diet + 100 mg/kg Ni + 1.0 × 108 CFU/mL Cp). The results showed that Cp challenge decreased the average daily gain (ADG) of days 15 to 21 (P<0.05) and increased interleukin-6 (IL-6) content in the serum (P < 0.05), as well as a significant reduction in villus height (VH) and the ratio of VH to crypt depth (VCR) (P<0.05) and a significant increase in crypt depth (CD) of jejunum (P<0.05). Furthermore, the mRNA expressions of Occludin and Claudin-1 were downregulated (P<0.05), while the mRNA expressions of Caspase3, Caspase9, Bax, and Bax/Bcl-2 were upregulated (P<0.05) in the jejunum. However, the inclusion of dietary Ni supplementation significantly improved body weight (BW) on days 21 and 28, ADG of days 15 to 21 (P<0.05), decreased CD in the jejunum, and reduced tumor necrosis factor-α (TNF-α) content in the serum (P<0.05). Ni addition upregulated the mRNA levels of Claudin-1 expression and downregulated the mRNA expression levels of Caspase9 in the jejunum (P<0.05). Moreover, Cp challenge and Ni altered the cecal microbiota composition, which manifested that Cp challenge decreased the relative abundance of phylum Fusobacteriota and increased Shannon index (P<0.05) and the trend of phylum Proteobacteria (0.05 Collapse

Key Words

• Clostridium perfringens
• broiler
• gut health
• necrotic enteritis
• nisin

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MESH Headings

• Animals
• Clostridium perfringens
• Chickens
• Intestines
• Clostridium Infections/prevention & control
• Clostridium Infections/veterinary
• Clostridium Infections/microbiology
• Nisin/pharmacology
• Claudin-1
• bcl-2-Associated X Protein/pharmacology
• Diet/veterinary
• RNA, Messenger/genetics
• Immunity
• Poultry Diseases/microbiology
• Dietary Supplements
• Animal Feed/analysis

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Affiliation(s)

Hua Yuan College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Guangdong Bai College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China College of Animal Science and Technology, Southwest University, Chongqing 400715, China
Yu Lin College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Xilong Yu College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Qinghui Yang College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Renkai Dou College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Hao Sun College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Zeyu Zhao College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Zhongyu Li College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Zhihui Chen College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China
Liangmei Xu College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China

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Gut microbiome: decision-makers in the microenvironment of colorectal cancer

Colorectal cancer (CRC) is a common malignancy of the gastrointestinal tract, accounting for the second most common cause of gastrointestinal tumors. As one of the intestinal barriers, gut bacteria form biofilm, participate in intestinal work, and form the living environment of intestinal cells. Metagenomic next-generation sequencing (mNGS) of the gut bacteria in a large number of CRC patients has been established, enabling specific microbial signatures to be associated with colorectal adenomato-carcinoma. Gut bacteria are involved in both benign precursor lesions (polyps), in situ growth and metastasis of CRC. Therefore, the term tumorigenic bacteria was proposed in 2018, such as Escherichia coli, Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, etc. Meanwhile, bacteria toxins (such as cytolethal distending toxin (CDT), Colibactin (Clb), B. fragilis toxin) affect the tumor microenvironment and promote cancer occurrence and tumor immune escape. It is important to note that there are differences in the bacteria of different types of CRC. In this paper, the role of tumorigenic bacteria in the polyp-cancer transformation and the effects of their secreted toxins on the tumor microenvironment will be discussed, thereby further exploring new ideas for the prevention and treatment of CRC.

Application Value of Antimicrobial Peptides in Gastrointestinal Tumors

Gastrointestinal cancer is a common clinical malignant tumor disease that seriously endangers human health and lacks effective treatment methods. As part of the innate immune defense of many organisms, antimicrobial peptides not only have broad-spectrum antibacterial activity but also can specifically kill tumor cells. The positive charge of antimicrobial peptides under neutral conditions determines their high selectivity to tumor cells. In addition, antimicrobial peptides also have unique anticancer mechanisms, such as inducing apoptosis, autophagy, cell cycle arrest, membrane destruction, and inhibition of metastasis, which highlights the low drug resistance and high specificity of antimicrobial peptides. In this review, we summarize the related studies on antimicrobial peptides in the treatment of digestive tract tumors, mainly oral cancer, esophageal cancer, gastric cancer, liver cancer, pancreatic cancer, and colorectal cancer. This paper describes the therapeutic advantages of antimicrobial peptides due to their unique anticancer mechanisms. The length, net charge, and secondary structure of antimicrobial peptides can be modified by design or modification to further enhance their anticancer effects. In summary, as an emerging cancer treatment drug, antimicrobial peptides need to be further studied to realize their application in gastrointestinal cancer diseases.

In Vitro Synergistic Antibacterial and Anti-Inflammatory Effects of Nisin and Lactic Acid in Yogurt against Helicobacter pylori and Human Gastric Cells

Helicobacter pylori is a bacterium that naturally thrives in acidic environments and has the potential to induce various gastrointestinal disorders in humans. The antibiotic therapy utilized for treating H. pylori can lead to undesired side effects, such as dysbiosis in the gut microbiota. The objective of our study was to explore the potential antibacterial effects of nisin and lactic acid (LA) in yogurt against H. pylori. Additionally, we investigated the anti-inflammatory effects of nisin and LA in human gastric (AGS) cells infected with H. pylori. Nisin and LA combination showed the strongest inhibitory activity, with confirmed synergy at 0.375 fractional inhibitory concentration index. Also, post-fermented yogurt with incorporation of nisin exhibited antibacterial effect against H. pylori. The combination of nisin and LA resulted in a significant reduction of mRNA levels of bacterial toxins of H. pylori and pro-inflammatory cytokines in AGS cells infected with H. pylori. Furthermore, this also increased bacterial membrane damage, which led to DNA and protein leakage in H. pylori. Overall, the combination of nisin and LA shows promise as an alternative therapy for H. pylori infection. Additionally, the incorporation of nisin into foods containing LA presents a potential application. Further studies, including animal research, are needed to validate these findings and explore clinical applications.

Probiotic-Derived Bioactive Compounds in Colorectal Cancer Treatment

Colorectal cancer (CRC) is a multifactorial disease with increased morbidity and mortality rates globally. Despite advanced chemotherapeutic approaches for the treatment of CRC, low survival rates due to the regular occurrence of drug resistance and deleterious side effects render the need for alternative anticancer agents imperative. Accumulating evidence supports that gut microbiota imbalance precedes the establishment of carcinogenesis, subsequently contributing to cancer progression and response to anticancer therapy. Manipulation of the gut microbiota composition via the administration of probiotic-derived bioactive compounds has gradually attained the interest of scientific communities as a novel therapeutic strategy for CRC. These compounds encompass miscellaneous metabolic secreted products of probiotics, including bacteriocins, short-chain fatty acids (SCFAs), lactate, exopolysaccharides (EPSs), biosurfactants, and bacterial peptides, with profound anti-inflammatory and antiproliferative properties. This review provides a classification of postbiotic types and a comprehensive summary of the current state of research on their biological role against CRC. It also describes how their intricate interaction with the gut microbiota regulates the proper function of the intestinal barrier, thus eliminating gut dysbiosis and CRC development. Finally, it discusses the future perspectives in precision-medicine approaches as well as the challenges of their synthesis and optimization of administration in clinical studies.

Gut microbiota in colorectal cancer development and therapy

Colorectal cancer (CRC) is one of the commonest cancers globally. A unique aspect of CRC is its intimate association with the gut microbiota, which forms an essential part of the tumour microenvironment. Research over the past decade has established that dysbiosis of gut bacteria, fungi, viruses and Archaea accompanies colorectal tumorigenesis, and these changes might be causative. Data from mechanistic studies demonstrate the ability of the gut microbiota to interact with the colonic epithelia and immune cells of the host via the release of a diverse range of metabolites, proteins and macromolecules that regulate CRC development. Preclinical and some clinical evidence also underscores the role of the gut microbiota in modifying the therapeutic responses of patients with CRC to chemotherapy and immunotherapy. Herein, we summarize our current understanding of the role of gut microbiota in CRC and outline the potential translational and clinical implications for CRC diagnosis, prevention and treatment. Emphasis is placed on how the gut microbiota could now be better harnessed by developing targeted microbial therapeutics as chemopreventive agents against colorectal tumorigenesis, as adjuvants for chemotherapy and immunotherapy to boost drug efficacy and safety, and as non-invasive biomarkers for CRC screening and patient stratification. Finally, we highlight the hurdles and potential solutions to translating our knowledge of the gut microbiota into clinical practice.

The Anti-Adhesion Effect of Nisin as a Robust Lantibiotic on the Colorectal Cancer Cells

Background

Bacteriocins are a type of antimicrobial peptide that are produced by probiotics. They have been studied as possible therapeutic drugs and have been used to suppress bacterial development in foods. Nisin is a potent bacteriocin having the anti-microbial and anti-cancer characteristics produced by Lactococcus lactis. The aim of the present paper is to evaluate the influence of Nisin on cell adhesion and its two related genes, mmp-2 and mmp-9, in the colorectal cancer cell line.

Materials and Methods

For this purpose, HT-29 cells were treated with various concentrations of Nisin and the cell cytotoxicity, cell adhesion, and gene expression were evaluated using the MTT assay, cell adhesion assay, and real-time PCR.

Results

Our findings showed that 32 to 1024 μg/ml of Nisin resulted in a significant reduction in cell viability (P < 0.05). Furthermore, 128 and 256 μg/ml of Nisin significantly reduced the cell adhesion, and mmp-2 and mmp-9 gene expressions (P < 0.05).

Conclusion

Our findings suggested that Nisin could prevent metastasis and cancer progression.

Pulmonary delivery of spray-dried Nisin ZP antimicrobial peptide for non-small cell lung cancer (NSCLC) treatment

Nisin ZP is an antimicrobial peptide (AMP) produced by the bacterium Lactococcus lactis, and we have previously demonstrated anticancer activity in NSCLC (A549) cells. In this study, we formulated a nisin ZP dry powder (NZSD) using a spray dryer to facilitate inhaled delivery for the treatment of NSCLC. Nisin ZP was spray-dried with mannitol, l-leucine, and trehalose in a ratio of 75:15:10 using Büchi mini spray-dryer B-290 in different drug loadings (10, 20, and 30% w/w). NZSD powder revealed a good powder yield of >55% w/w with ≤3 % w/w moisture content and high nisin ZP drug loading for all the peptide ratios. The NZSD powder particles were irregularly shaped with corrugated morphology. The presence of an endothermic peak in DSC thermograms and attenuated crystalline peaks in PXRD diffractograms confirmed the semi-crystalline powder nature of NZSD. The anticancer activity of nisin ZP was maintained after fabricating it into NZSD powder and showed a similar inhibitory concentration to free nisin ZP. Stability studies indicated that NZSD powders were stable for three months at 4 and 25 ℃ with more than 90% drug content and semi-crystalline nature, as confirmed by DSC and PXRD. Aerosolization studies performed using NGI indicated an aerodynamic diameter (MMAD) within the desired range (1-5 µm) and a high fine particle fraction (FPF > 75%) for all peptide ratios, suggesting powder deposition in the lung's respiratory airways. In conclusion, a dry powder of nisin ZP was formulated using a spray dryer with enhanced storage stability and suitable for inhaled delivery.

Hierarchical encapsulation of bacteria in functional hydrogel beads for inter- and intra- species communication

To sequester prokaryotic cells in a biofilm-like niche, the creation of a pertinent and reliable microenvironment that reflects the heterogeneous nature of biological systems is vital for sustenance. Design of a microenvironment that is conducive for growth and survival of organisms, should account for factors such as mass transport, porosity, stability, elasticity, size, functionality, and biochemical characteristics of the organisms in the confined architecture. In this work we present an artificial long-term confinement model fabricated by natural alginate hydrogels that are structurally stable and can host organisms for over 10 days in physiologically relevant conditions. A unique feature of the confinement platform is the development of stratified habitats wherein bacterial cells can be entrapped in the core as well as in the shell layers, wherein the thickness and the number of shell layers are tunable at fabrication. We show that the hydrogel microenvironment in the beads can host complex subpopulations of organisms similar to that in a biofilm. Dynamic interaction of bacterial colonies encapsulated in different beads or within the core and stratified layers of single beads was demonstrated to show intra- species communication. Inter- species communication between probiotic bacteria and human colorectal carcinoma cells was also demonstrated to highlight a possible bidirectional communication between the organisms in the beads and the environment. STATEMENT OF SIGNIFICANCE: Bacteria confinement in a natural soft hydrogel structure has always been a challenge due to the collapse of hydrogel architectures. Alternative methods have been attempted to encapsulate microorganisms by employing various processes to avoid/minimize rupturing of hydrogel structures. However, most of the past approaches have been unfavorable in balancing cell proliferation and functionality upon confinement. Our study addresses the fundamental gap in knowledge necessary to create favorable and complex 3D biofilm mimics utilizing natural hydrogel for microbial colonization for long-term studies. Our approach represents a cornerstone in the development of 3D functional architectures not only to advance studies in microbial communication, host-microbe interaction but also to address basic and fundamental questions in biology.

Proteins and their functionalization for finding therapeutic avenues in cancer: Current status and future prospective

Despite the remarkable advancement in the health care sector, cancer remains the second most fatal disease globally. The existing conventional cancer treatments primarily include chemotherapy, which has been associated with little to severe side effects, and radiotherapy, which is usually expensive. To overcome these problems, target-specific nanocarriers have been explored for delivering chemo drugs. However, recent reports on using a few proteins having anticancer activity and further use of them as drug carriers have generated tremendous attention for furthering the research towards cancer therapy. Biomolecules, especially proteins, have emerged as suitable alternatives in cancer treatment due to multiple favourable properties including biocompatibility, biodegradability, and structural flexibility for easy surface functionalization. Several in vitro and in vivo studies have reported that various proteins derived from animal, plant, and bacterial species, demonstrated strong cytotoxic and antiproliferative properties against malignant cells in native and their different structural conformations. Moreover, surface tunable properties of these proteins help to bind a range of anticancer drugs and target ligands, thus making them efficient delivery agents in cancer therapy. Here, we discuss various proteins obtained from common exogenous sources and how they transform into effective anticancer agents. We also comprehensively discuss the tumor-killing mechanisms of different dietary proteins such as bovine α-lactalbumin, hen egg-white lysozyme, and their conjugates. We also articulate how protein nanostructures can be used as carriers for delivering cancer drugs and theranostics, and strategies to be adopted for improving their in vivo delivery and targeting. We further discuss the FDA-approved protein-based anticancer formulations along with those in different phases of clinical trials.

Microbial metabolites in colorectal tumorigenesis and cancer therapy

Trillions of microbes are indigenous to the human gastrointestinal tract, together forming an ecological community known as the gut microbiota. The gut microbiota is involved in dietary digestion to produce various metabolites. In healthy condition, microbial metabolites have unneglectable roles in regulating host physiology and intestinal homeostasis. However, increasing studies have reported the correlation between metabolites and the development of colorectal cancer (CRC), with the identification of oncometabolites. Meanwhile, metabolites can also influence the efficacy of cancer treatments. In this review, metabolites derived from microbes-mediated metabolism of dietary carbohydrates, proteins, and cholesterol, are introduced. The roles of pro-tumorigenic (secondary bile acids and polyamines) and anti-tumorigenic (short-chain fatty acids and indole derivatives) metabolites in CRC development are then discussed. The impacts of metabolites on chemotherapy and immunotherapy are further elucidated. Collectively, given the importance of microbial metabolites in CRC, therapeutic approaches that target metabolites may be promising to improve patient outcome.

Anticancer activity of lactic acid bacteria

Lactic acid bacteria (LAB), a group of Gram-positive microorganisms naturally occurring in fermented food products and used as probiotics, have been gaining the interest of researchers for years. LAB are potent, albeit still not wholly understood, source of bioactive compounds with various functions and activity. Metabolites of LAB, among others, short-chain fatty acids, exopolysaccharides and bacteriocins have promising anticancer potential. Research on the interactions between the bioactive metabolites of LAB and immune mechanisms demonstrated that these substances could exert a strong immunomodulatory effect, which would explain their vast therapeutic potential. The anticancer activity of LAB was confirmed both in vitro and in animal models against cancer cells from various malignancies. LAB inhibit tumor growth through various mechanisms, including antiproliferative activity, induction of apoptosis, cell cycle arrest, as well as through antimutagenic, antiangiogenic and anti-inflammatory effects. The aim of this review was to summarize the most recent data about the anticancer activity of LAB, with particular emphasis on the most promising bioactive compounds with potential clinical application.

An investigation of bacteriocin nisin anti-cancer effects and FZD7 protein interactions in liver cancer cells

The bacteriocin, nisin, produced by Lactococcus and Streptococcus species during fermentation, is widely used for bio preservatives in a wide variety of foods. Liver cancer has a high mortality rate and is the fourth leading cause of cancer-related deaths worldwide. Recently, researchers have shown the anti-cancer effects of nisin through in vitro and in vivo studies. This study aimed to investigate the effect of nisin on liver cancer cell lines, which represented two subgroups of the disease model. Nisin exhibited significant growth inhibition and apoptosis in both cell lines, HuH-7, and SNU182. Drug resistance is the main problem in liver cancer and the epithelial-to-mesenchymal transition has a role in the development of drug resistance in hepatocellular carcinoma. The expression of EMT transcription factors ZEB1, SNAI1, and TWIST1 were analyzed depending on nisin treatment, TWIST1 expression was down-regulated after nisin treatment compared to the untreated SNU182 and HuH-7 cell lines. Besides, due to the reported correlation between the overexpression of Frizzled (FZD) proteins, specifically FZD7, in primary hepatocellular carcinomas (HCCs), molecular docking was assessed for Nisin A in the binding site of FZD7. Results confirmed that Nisin A was able to form important hydrogen bonding with key residues. This research not only determined the role of nisin in different liver cancer cell models but it also provided the first result of FZD7 and nisin interaction.

Bacteriocins as Potential Therapeutic Approaches in the Treatment of Various Cancers: A Review of In Vitro Studies

Simple Summary

Current cancer treatment strategies such as surgery, chemotherapy, and radiotherapy, have significant drawbacks. There is a need for a breakthrough approach to cancer treatment. Bacteriocin, an antimicrobial peptide, has shown several anticancer properties in vitro. Therefore, this article reviews the effect of bacteriocin on cancer cells and how bacteriocins affect cancer cells in vitro. This article aims to promote additional bacteriocin research, particularly in vivo studies, to fully understand the potential of bacteriocin as a cancer treatment agent.

Abstract

Cancer is regarded as one of the most common and leading causes of death. Despite the availability of conventional treatments against cancer cells, current treatments are not the optimal treatment for cancer as they possess the possibility of causing various unwanted side effects to the body. As a result, this prompts a search for an alternative treatment without exhibiting any additional side effects. One of the promising novel therapeutic candidates against cancer is an antimicrobial peptide produced by bacteria called bacteriocin. It is a non-toxic peptide that is reported to exhibit potency against cancer cell lines. Experimental studies have outlined the therapeutic potential of bacteriocin against various cancer cell lines. In this review article, the paper focuses on the various bacteriocins and their cytotoxic effects, mode of action and efficacies as therapeutic agents against various cancer cell lines.

Do Bacteria Provide an Alternative to Cancer Treatment and What Role Does Lactic Acid Bacteria Play?

Cancer is one of the leading causes of mortality and morbidity worldwide. According to 2022 statistics from the World Health Organization (WHO), close to 10 million deaths have been reported in 2020 and it is estimated that the number of cancer cases world-wide could increase to 21.6 million by 2030. Breast, lung, thyroid, pancreatic, liver, prostate, bladder, kidney, pelvis, colon, and rectum cancers are the most prevalent. Each year, approximately 400,000 children develop cancer. Treatment between countries vary, but usually includes either surgery, radiotherapy, or chemotherapy. Modern treatments such as hormone-, immuno- and antibody-based therapies are becoming increasingly popular. Several recent reports have been published on toxins, antibiotics, bacteriocins, non-ribosomal peptides, polyketides, phenylpropanoids, phenylflavonoids, purine nucleosides, short chain fatty acids (SCFAs) and enzymes with anticancer properties. Most of these molecules target cancer cells in a selective manner, either directly or indirectly through specific pathways. This review discusses the role of bacteria, including lactic acid bacteria, and their metabolites in the treatment of cancer.

Nisin and nisin-loaded nanoparticles: a cytotoxicity investigation

OBJECTIVE

Nisin is an antibacterial peptide with anticancer properties, but the main drawback is its rapid enzymatic degradation and limited permeation across the cell membrane. This research aims to to overcome these drawbacks by developing nisin-loaded nanoparticles with improved cytotoxic effects.

SIGNIFICANCE

PLGA nanoparticles are one of the most effective biodegradable and biocompatible drug delivery carriers. In the present study, nisin-loaded nanoparticles showed enhanced anticancer effects.

METHODS

NPN was prepared by a double emulsion solvent evaporation method and characterized for different parameters. The cytotoxic investigation of NPN was carried out on various cell lines, including A549, SW-620, HT-29, PC-3, MDA-MB-231, MCF-7, MiaPaca-2, and fR2 by sulforhodamine B (SRB) assay. Mechanistic investigation of cellular cytotoxicity was performed by using bright-field microscopy, DAPI staining, intracellular reactive oxygen species (ROS), changes in mitochondrial membrane potential (ΔΨm), and western blotting. A comparative cytotoxicity study of nisin and NPN was performed on normal breast epithelial cells (fR-2).

RESULTS

NPN showed spherical shape, 289.09 ± 3.63 nm particle size, and 63.37 ± 3.12% entrapment efficiency. NPN was more cytotoxic to the MDA-MB-231 cell line, showing higher nuclear fragmentation, ROS generation, and depletion of ΔΨm like apoptosis signs compared to nisin and with no cytotoxicity on normal cells.

CONCLUSIONS

The findings suggest that nisin delivery via PLGA nanoparticles can be used to treat cancer without significant effects on healthy cells.

Designing a novel fusion protein from Streptococcus agalactiae with apoptosis induction effects on cervical cancer cells

Cervical cancer remains life-threatening cancer in women around the world. Due to the limitations of conventional treatment approaches, there is an urgent need to develop novel and more efficient strategies against cervical cancer. Therefore, the researchers attend to the alternative anti-cancer compounds like bacterial products. Rib and α are known as surface proteins of Streptococcus agalactiae with immunologic effects. In the present study, we designed a new anti-cancer fusion protein (Rib-α) originating from S. agalactiae with in silico methods, and then, the recombinant gene was cloned in the pET-22 (+) expression vector. The recombinant protein was expressed in E. coli BL21. To purify the expressed protein, we applied the Ni-NTA column. The molecular mechanism by which Rib-α is cytotoxic to cancer cells has been discussed based on MTT, flow cytometry, and real-time PCR methods. The engineered fusion protein suppressed the proliferation of the cancer cells at 180 μg/ml. Cytotoxic assessment and morphological changes, augmentation of apoptotic-related genes, upregulation of caspase-3 mRNA, and flow cytometric analysis confirmed that apoptosis might be the principal mechanism of cell death. According to our findings, Rib-α fusion protein motivated the intrinsic apoptosis pathway. Therefore, it can be an exciting candidate to discover a new class of antineoplastic agents.

Strategies to Combat Caries by Maintaining the Integrity of Biofilm and Homeostasis during the Rapid Phase of Supragingival Plaque Formation

Bacteria in the oral cavity, including commensals and opportunistic pathogens, are organized into highly specialized sessile communities, coexisting in homeostasis with the host under healthy conditions. A dysbiotic environment during biofilm evolution, however, allows opportunistic pathogens to become the dominant species at caries-affected sites at the expense of health-associated taxa. Combining tooth brushing with dentifrices or rinses combat the onset of caries by partially removes plaque, but resulting in the biofilm remaining in an immature state with undesirables’ consequences on homeostasis and oral ecosystem. This leads to the need for therapeutic pathways that focus on preserving balance in the oral microbiota and applying strategies to combat caries by maintaining biofilm integrity and homeostasis during the rapid phase of supragingival plaque formation. Adhesion, nutrition, and communication are fundamental in this phase in which the bacteria that have survived these adverse conditions rebuild and reorganize the biofilm, and are considered targets for designing preventive strategies to guide the biofilm towards a composition compatible with health. The present review summarizes the most important advances and future prospects for therapies based on the maintenance of biofilm integrity and homeostasis as a preventive measure of dysbiosis focused on these three key factors during the rapid phase of plaque formation.

Nisin Variants Generated by Protein Engineering and Their Properties

Nisin, a typical lantibiotic, has robust antimicrobial activity combined with limited cytotoxicity, and the development of resistance to it is slow. These properties make nisin a promising antimicrobial agent to control pathogenic microorganisms in dairy foods. However, its low solubility, poor stability and short half-life at neutral pH limit its application within the dairy industry. Protein engineering technology has revealed the potential of modifying nisin to improve its properties, and many valuable variants have emerged. This review summarizes progress in the generation of nisin variants for the dairy industry and for other purposes. These nisin variants with additional modification have improved properties and can even expand the inhibition spectrum range of nisin. Nisin, as the most thoroughly studied lantibiotic, and its variants can also guide the modification of other lantibiotics.

The role of key gut microbial metabolites in the development and treatment of cancer

In recent years, the role of gut microbial metabolites on the inhibition and progression of cancer has gained significant interest in anticancer research. It has been established that the gut microbiome plays a pivotal role in the development, treatment and prognosis of different cancer types which is often mediated through the gut microbial metabolites. For instance, gut microbial metabolites including bacteriocins, short-chain fatty acids and phenylpropanoid-derived metabolites have displayed direct and indirect anticancer activities through different molecular mechanisms. Despite the reported anticancer activity, some gut microbial metabolites including secondary bile acids have exhibited pro-carcinogenic properties. This review draws a critical summary and assessment of the current studies demonstrating the carcinogenic and anticancer activity of gut microbial metabolites and emphasises the need to further investigate the interactions of these metabolites with the immune system as well as the tumour microenvironment in molecular mechanistic and clinical studies.

Bacteria-Mediated Modulatory Strategies for Colorectal Cancer Treatment

Colorectal cancer (CRC) is one of the most common tumors worldwide, with a higher rate of distant metastases than other malignancies and with regular occurrence of drug resistance. Therefore, scientists are forced to further develop novel and innovative therapeutic treatment strategies, whereby it has been discovered microorganisms, albeit linked to CRC pathogenesis, are able to act as highly selective CRC treatment agents. Consequently, researchers are increasingly focusing on bacteriotherapy as a novel therapeutic strategy with less or no side effects compared to standard cancer treatment methods. With multiple successful trials making use of various bacteria-associated mechanisms, bacteriotherapy in cancer treatment is on its way to become a promising tool in CRC targeting therapy. In this study, we describe the anti-cancer effects of bacterial therapy focusing on the treatment of CRC as well as diverse modulatory mechanisms and techniques that bacteriotherapy offers such as bacterial-related biotherapeutics including peptides, toxins, bacteriocins or the use of bacterial carriers and underlying molecular processes to target colorectal tumors.

Nisin ZP, an Antimicrobial Peptide, Induces Cell Death and Inhibits Non-Small Cell Lung Cancer (NSCLC) Progression in vitro in 2D and 3D Cell Culture

Lung cancer is the leading cause of cancer deaths globally with most of the reported cases (> 85%) associated with non-small cell lung cancer (NSCLC). Current therapies have enhanced the overall survival rate of patients but treatment-related adverse effects and increase in drug-resistance limit the success of these treatment options. Antimicrobial peptides (AMPs) have gained interest as anticancer agents as they selectively target cancer cells and decrease the possibility of resistance. Nisin ZP is a polycyclic antimicrobial peptide produced by the Gram-positive bacterium, Lactococcus lactis and is commonly used as a food preservative. Nisin ZP has recently demonstrated anticancer activity in melanoma, head and neck squamous cell carcinoma, hepatic, colon, and blood cancer. In this study, we evaluated the anticancer potential of nisin ZP and assessed the underlying mechanisms in NSCLC cells. The results revealed that nisin ZP induced selective toxicity in cancer (A549 and H1299) cells compared to healthy (HEK293) cells after 48 h of treatment. Nisin ZP exposure induced apoptosis and cell cycle arrest (G0/G1 phase) in NSCLC cells irrespective of tumor protein p53 expression. The cancer cell proliferation was inhibited via non-membranolytic pathways by mitochondrial membrane depolarization and elevation in reactive oxygen species (ROS) generation. Furthermore, nisin ZP decreased cancer cells' clonal expansion and migration, demonstrating potential use against highly metastatic NSCLC. The 3D spheroid growth and cell viability of the A549 cells were significantly inhibited by nisin ZP compared to control. Overall, the results suggest an excellent antitumor potential in vitro and, thus, can further be developed as a novel therapeutic for NSCLC.

Stabilization and Anticancer Enhancing Activity of the Peptide Nisin by Cyclodextrin-Based Nanosponges against Colon and Breast Cancer Cells

The great variability of cancer types demands novel drugs with broad spectrum, this is the case of Nisin, a polycyclic antibacterial peptide that recently has been considered for prevention of cancer cells growth. As an accepted food additive, this drug would be very useful for intestinal cancers, but the peptide nature would make easier its degradation by digestion procedures. For that reason, the aim of present study to investigate the protective effect of two different β-cyclodextrin-based nanosponges (carbonyl diimidazole and pyromellitic dianhydride) and their anti-cancer enhancement effect of Nisin-Z encapsulated with against colon cancer cells (HT-29). To extend its possible use, a comparison with breast (MCF-7) cancer cell was carried out. The physicochemical properties, loading efficiency, and release kinetics of Nisin complex with nanosponges were studied. Then, tricin-SDS-PAGE electrophoresis was used to understand the effect of NSs on stability of Nisin-Z in the presence of gastric peptidase pepsin. In addition, the cytotoxicity and cell membrane damage of Nisin Z were evaluated by using the MTT and LDH assay, which was complemented via Annexin-V/ Propidium Iodide (PI) by using flowcytometry. CD-NS are able to complex Nisin-Z with an encapsulation efficiency around 90%. A protective effect of Nisin-Z complexed with CD-NSs was observed in presence of pepsin. An increase in the percentage of apoptotic cells was observed when the cancer cells were exposed to Nisin Z complexed with nanosponges. Interestingly, Nisin Z free and loaded on PMDA/CDI-NSs is more selectively toxic towards HT-29 cells than MCF-7 cancer cells. These results indicated that nanosponges might be good candidates to protect peptides and deliver drugs against intestinal cancers.

Nisin induces apoptosis in cervical cancer cells via reactive oxygen species generation and mitochondrial membrane potential changes

Nisin, an antimicrobial peptide produced by Lactococcus lactis, is widely used as a safe food preservative and has been recently attracting the attention of many researchers as a potential anticancer agent. The cytotoxicity of nisin against HeLa, OVCAR-3, SK-OV-3, and HUVEC cells was evaluated using MTT assay. The apoptotic effect of nisin was identified by Annexin-V/propidium iodide assay, and then it was further confirmed by western blotting analysis, mitochondrial membrane potential (ΔΨm) analysis, and reactive oxygen species (ROS) assay. The MTT assay showed concentration-dependent cytotoxicity of nisin towards cancer cell lines, with the IC50 values of 11.5-23 µM, but less toxicity against normal endothelial cells. Furthermore, treatment of cervical cancer cells with 12 µM nisin significantly (P<0.05) increased the Bax/Bcl-2 ratio (4.9-fold), reduced ΔΨm (70%), and elevated ROS levels (1.7-fold). These findings indicated that nisin might have anticancer and apoptogenic activities through mitochondrial dysfunction and oxidative stress damage in cervical cancer cells.

The role played by bacterial infections in the onset and metastasis of cancer

Understanding various responses of cells towards change in their external environment, presence of other species and is important in identifying and correlating the mechanisms leading to malignant transformations and cancer development. Although uncovering and comprehending the association between bacteria and cancer is highly challenging, it promises excellent perspectives and approaches for successful cancer therapy. This review introduces various bacterial species, their virulence factors, and their role in cell transformations leading to cancer (particularly gastric, oral, colon, and breast cancer). Bacterial dysbiosis permutates host cells, causes inflammation, and results in tumorigenesis. This review explored bacterial-mediated host cell transformation causing chronic inflammation, immune receptor hyperactivation/absconding immune recognition, and genomic instability. Bacterial infections downregulate E-cadherin, leading to loosening of epithelial tight junction polarity and triggers metastasis. In addition to understanding the role of bacterial infections in cancer development, we have also reviewed the application of bacteria for cancer therapy. The emergence of bacteriotherapy combined with conventional therapies led to new and effective ways of overcoming challenges associated with available treatments. This review discusses the application of bacterial minicells, microswimmers, and outer cell membrane vesicles (OMV) for drug delivery applications.

Alterations in Faecal Microbiota and Elevated Levels of Intestinal IgA Following Oral Administration of Lacticaseibacillus casei in mice

The intestinal microbiota has been identified as a crucial regulator of the overall health, with studies describing its influence in a variety of disorders and developmental processes throughout the body. A widely accepted approach of influencing the microbiota and regulating its functionality in health or disease is the consumption of probiotics. In this study, we aimed to identify the impact of probiotic Lacticaseibacillus casei ATCC393 on the intestinal microbiota of mice and circulating soluble products of microbial origin or the immune system. Investigation of the gut microflora using next-generation sequencing analysis revealed alterations in the microbial populations following consumption of the probiotic. Abundance of taxa classified as Muribaculaceae was increased in lactobacilli-fed animals, while abundance of taxa classified as Lachnospiraceae and Oscillospiraceae was decreased. In addition, the composition of the intestinal microbiota was modified by the administration of L. casei, as evident by the clustering of test subjects when inspecting beta diversity, without however any significant effect on the alpha diversity of the animals. Finally, production of IgA in the intestinal lumen of mice that had received the microorganism was significantly increased, as was the concentration of lactic acid, while levels of acetic acid were noticeably lower in the L. casei group. The findings suggest that L. casei can be considered a potential candidate strain for the modulation of intestinal homeostasis and a component of dietary interventions aiming to improve overall health.

Challenges in the production and use of probiotics as therapeuticals in cancer treatment or prevention

Probiotics were defined as microbial strains that confer health benefits to their consumers. The concept has evolved during the last twenty years, and today metabolites produced by the strains, known as postbiotics, and even dead cells, known as paraprobiotics are closely associated to them. The isolation of commensal strains from human microbiome has led to the development of next generation probiotics. This review aims to present an overview of the developments in the area of cancer prevention and treatment, intimately related to advances in the knowledge of the microbiome role in its genesis and therapy. Strain identification and characterization, production processes, delivery strategies and clinical evaluation are crucial to translate results into the market with solid scientific support. Examples of recent tools in isolation, strain typification, quality control and development of new probiotic strains are described. Probiotics market and regulation were originally developed in the food sector, but these new strategies will impact the pharmaceutical and health sectors, requiring new considerations in regulatory frameworks.

Impact of nisin on Clostridioides difficile and microbiota composition in a faecal fermentation model of the human colon

AIMS

Nisin is a bacteriocin with a broad spectrum of activity against Gram-positive bacteria. The aims were to assess nisin activity against Clostridioides difficile in a complex microbial environment and determine the minimum inhibitory concentration at which C. difficile growth is suppressed whilst having minimal impact on the faecal microbiota.

METHODS AND RESULTS

Faecal slurries were prepared from fresh faecal samples and spiked with C. difficile (10⁶  CFU per ml). Nisin was added to each fermentation at a range of concentrations from 0 to 500 µM. Following 24 h, 16S rRNA gene sequencing was performed, and the presence of viable C. difficile was assessed. There was no viable C. difficile detected in the presence of 50-500 µM nisin. There was a decrease in the diversity of the microbiota in a nisin dose-dependent manner. Nisin predominantly depleted the relative abundance of the Gram-positive bacteria whilst the relative abundance of Gram-negative bacteria such as Escherichia Shigella and Bacteroides increased.

CONCLUSIONS

Using an ex vivo model of the colon, this study demonstrates the ability of purified nisin to selectively deplete C. difficile in a faecal microbial environment and establishes the minimum concentration at which this occurs whilst having a minimal impact on the composition of the microbiota.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study opens up the potential to use nisin as a therapeutic for clostridial gut infections.

Mining and Biosynthesis of Bioactive Lanthipeptides From Microorganisms

Antimicrobial resistance is one of the most serious public health issues in the worldwide and only a few new antimicrobial drugs have been discovered in recent decades. To overcome the ever-increasing emergence of multidrug-resistant (MDR) pathogens, discovery of new natural products (NPs) against MDR pathogens with new technologies is in great demands. Lanthipeptides which are ribosomally synthesized and post-translationally modified peptides (RiPPs) display high diversity in their chemical structures and mechanisms of action. Genome mining and biosynthetic engineering have also yielded new lanthipeptides, which are a valuable source of drug candidates. In this review we cover the recent advances in the field of microbial derived lanthipeptide discovery and development.

Antimicrobial peptides as potential therapeutics for breast cancer

Breast cancer is the most common and deadliest cancer in women worldwide. Although notable advances have been achieved in the treatment of breast cancer, the overall survival rate of metastatic breast cancer patients is still considerably low due to the development of resistance to breast cancer chemotherapeutic agents and the non-optimal specificity of the current generation of cancer medications. Hence, there is a growing interest in the search for alternative therapeutics with novel anticancer mechanisms. Recently, antimicrobial peptides (AMPs) have gained much attention due to their cost-effectiveness, high specificity of action, and robust efficacy. However, there are no clinical data available about their efficacy. This warrants the increasing need for clinical trials to be conducted to assess the efficacy of this new class of drugs. Here, we will focus on the recent progress in the use of AMPs for breast cancer therapy and will highlight their modes of action. Finally, we will discuss the combination of AMP-based therapeutics with other breast cancer therapy strategies, including nanotherapy and chemotherapy, which may provide a potential avenue for overcoming drug resistance.

Colorectal cancer treatment using bacteria: focus on molecular mechanisms

BACKGROUND

Colorectal cancer which is related to genetic and environmental risk factors, is among the most prevalent life-threatening cancers. Although several pathogenic bacteria are associated with colorectal cancer etiology, some others are considered as highly selective therapeutic agents in colorectal cancer. Nowadays, researchers are concentrating on bacteriotherapy as a novel effective therapeutic method with fewer or no side effects to pay the way of cancer therapy. The introduction of advanced and successful strategies in bacterial colorectal cancer therapy could be useful to identify new promising treatment strategies for colorectal cancer patients.

MAIN TEXT

In this article, we scrutinized the beneficial effects of bacterial therapy in colorectal cancer amelioration focusing on different strategies to use a complete bacterial cell or bacterial-related biotherapeutics including toxins, bacteriocins, and other bacterial peptides and proteins. In addition, the utilization of bacteria as carriers for gene delivery or other known active ingredients in colorectal cancer therapy are reviewed and ultimately, the molecular mechanisms targeted by the bacterial treatment in the colorectal cancer tumors are detailed.

CONCLUSIONS

Application of the bacterial instrument in cancer treatment is on its way through becoming a promising method of colorectal cancer targeted therapy with numerous successful studies and may someday be a practical strategy for cancer treatment, particularly colorectal cancer.

Anticancer Effect of Enterocin A-Colicin E1 Fusion Peptide on the Gastric Cancer Cell

Cancer is one of the most causes of death all over the world, although improvements in its treatment and recognition. Due to the limitations of common anticancer methods, including surgery, chemotherapy, and radiotherapy, attention has been drawn to other anti-cancer compounds, especially natural peptides such as bacteriocins. In this study, we used a combination of two bacteriocins, colicin E1 and enterocin A, against AGS gastric cancer cell lines. In order to evaluate anticancer properties of fusion peptide, we applied MTT assay, real-time PCR, and flow cytometry tests. This is the first report to show the cell growth inhibitory activity of the enterocin A in combination with colicin E1 against AGS human cancer cells. The results of this study showed that this fusion peptide at a concentration of 60.4 µg/mL and 24 h was able to kill half of the tested cancer cells, and treatment of the cells with this concentration increased the expression of bax and caspase 3 genes and reduced the expression of bacl-2 in 24 h. Flow cytometry analysis of annexin V-FITC/propidium iodide results also showed that our peptide was able to induce apoptosis in treated cells compared with control. Taken together, enterocin A-colicin E1 (ent A-col E1) can be considered as a good candidate for anticancer therapies.

CBP22, a Novel Bacteriocin Isolated from Clostridium butyricum ZJU-F1, Protects against LPS-Induced Intestinal Injury through Maintaining the Tight Junction Complex

A novel bacteriocin secreted by Clostridium butyricum ZJU-F1 was isolated using ammonium sulfate fractionation, cation exchange chromatography, affinity chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). The bacteriocin, named CBP22, contained 22 amino acids with the sequence PSAWQITKCAGSIAWALGSGIF. Analysis of its structure and physicochemical properties indicated that CBP22 had a molecular weight of 2264.63 Da and a +1 net charge. CBP22 showed activity against E. col K88, E. coli ATCC25922, and S. aureus ATCC26923. The effects and potential mechanisms of bacteriocin CBP22 on the innate immune response were investigated with a lipopolysaccharide- (LPS-) induced mouse model. The results showed that pretreatment with CBP22 prevented LPS-induced impairment in epithelial tissues and significantly reduced serum levels of IgG, IgA, IgM, TNF-α, and sIgA. Moreover, CBP22 treatment increased the expression of the zonula occludens and reduced permeability as well as apoptosis in the jejunum in LPS-treated mice. In summary, CBP22 inhibits the intestinal injury and prevents the gut barrier dysfunction induced by LPS, suggesting the potential use of CBP22 for treating intestinal damage.