The soybean-derived peptide lunasin inhibits non-small cell lung cancer cell proliferation by suppressing phosphorylation of the retinoblastoma protein

Polypeptides from traditional Chinese medicine: Comprehensive review of perspective towards cancer management

Cancer has always been a focus of global attention, and the difficulty of treatment and poor prognosis have always plagued humanity. Conventional chemotherapeutics and treatment with synthetic disciplines will cause adverse side effects and drug resistance. Therefore, searching for a safe, valid, and clinically effective drug is necessary. At present, some natural compounds have proved to have the potential to fight cancer. Polypeptides obtained from traditional Chinese medicine are good anti-cancer ingredients. The anticancer activity has been fully demonstrated in vivo and in vitro. However, most of the functional studies on traditional Chinese medicine polypeptides are at the stage of basic experimental research, and fewer of them have been applied to clinical trials. Hence, this review mainly discusses the chemical structure, extraction, separation and purification methods, the anti-cancer mechanism, and structure-activity relationships of traditional Chinese medicine polypeptides. It provides theoretical support for strengthening the rapid separation and purification and the overall efficacy and mechanism of action, as well as the industrialization and clinical application of traditional Chinese medicine polypeptides.

Anti-Cancer Properties of Flaxseed Proteome

Flaxseed has been recognized as a valuable source of nutrients and bioactive compounds, including proteins that possess various health benefits. In recent years, studies have shown that flaxseed proteins, including albumins, globulins, glutelin, and prolamins, possess anti-cancer properties. These properties are attributed to their ability to inhibit cancer cell proliferation, induce apoptosis, and interfere with cancer cell signaling pathways, ultimately leading to the inhibition of metastasis. Moreover, flaxseed proteins have been reported to modulate cancer cell mechanobiology, leading to changes in cell behavior and reduced cancer cell migration and invasion. This review provides an overview of the anti-cancer properties of flaxseed proteins, with a focus on their potential use in cancer treatment. Additionally, it highlights the need for further research to fully establish the potential of flaxseed proteins in cancer therapy.

Natural Bacterial and Fungal Peptides as a Promising Treatment to Defeat Lung Cancer Cells

Despite the increasing availability of modern treatments, including personalized therapies, there is a strong need to search for new drugs that will be effective in the fight against cancer. The chemotherapeutics currently available to oncologists do not always yield satisfactory outcomes when used in systemic treatments, and patients experience burdensome side effects during their application. In the era of personalized therapies, doctors caring for non-small cell lung cancer (NSCLC) patients have been given a powerful weapon, namely molecularly targeted therapies and immunotherapies. They can be used when genetic variants of the disease qualifying for therapy are diagnosed. These therapies have contributed to the extension of the overall survival time in patients. Nevertheless, effective treatment may be hindered in the case of clonal selection of tumor cells with acquired resistance mutations. The state-of-the-art therapy currently used in NSCLC patients is immunotherapy targeting the immune checkpoints. Although it is effective, some patients have been observed to develop resistance to immunotherapy, but its cause is still unknown. Personalized therapies extend the lifespan and time to cancer progression in patients, but only those with a confirmed marker qualifying for the treatment (gene mutations/rearrangements or PD-L1 expression on tumor cells) can benefit from these therapies. They also cause less burdensome side effects than chemotherapy. The article is focused on compounds that can be used in oncology and produce as few side effects as possible. The search for compounds of natural origin, e.g., plants, bacteria, or fungi, exhibiting anticancer properties seems to be a good solution. This article is a literature review of research on compounds of natural origin that can potentially be used as part of NSCLC therapies.

Lunasin and Its Epigenetic Impact in Cancer Chemoprevention

Cancer diseases are a leading cause of death worldwide. Therefore, it is pivotal to search for bioactive dietary compounds that can avert tumor development. A diet rich in vegetables, including legumes, provides chemopreventive substances, which have the potential to prevent many diseases, including cancer. Lunasin is a soy-derived peptide whose anti-cancer activity has been studied for over 20 years. The results of the previous research have shown that lunasin inhibits histone acetylation, regulates the cell cycle, suppresses proliferation and induces apoptosis of cancer cells. Thus, lunasin seems to be a promising bioactive anti-cancer agent and a potent epigenetic modulator. The present review discusses studies of the underlying molecular mechanisms and new perspectives on lunasin application in epigenetic prevention and anti-cancer therapy.

Fucoidan/hyaluronic acid cross-linked zein nanoparticles loaded with fisetin as a novel targeted nanotherapy for oral cancer

Fisetin (FS) is an anticancer drug having potential role in oral tumors management. However, its clinical application is limited due to its hydrophobicity and instability. Bioactive polymers-based nanosystems have a great potential in cancer therapy. Herein, different biopolymers were selected for their anticancer activity and targeting ability for nanoparticles preparation namely; fucoidan (FU), zein (Zn) and hyaluronic acid (HA). The selected FS-loaded cross-linked Zn nanoparticles (ZFH) which contains HA& FU for Zn nanoparticles stabilization showed the most suitable particle size (196 ± 6.53 nm), mean surface net charge (-38.8 ± 1.47 mV) and entrapment efficiency (98 ± 1.2 %). This is the first study to utilize both HA &FU not only for stabilization but also for dual targeting effect due to their targeting ability to multiple tumor targets. In-vitro anticancer activity of ZHF revealed remarkable uptake by SCC-4 cells with significant cytotoxic action. Further, ZHF was appraised using 4-nitroquinoline 1-oxide (4-NQO)-induced oral cancer in-vivo; ZHF significantly reduced OSCC-specific serum biomarkers levels, histologic tumor grade and increased caspase-3 level. Moreover, potential of destroying two key tumor regulatory cells; TECs and CSCs, was evaluated using their specific markers. The elaborated ZFH nanoparticles could be considered as promising targeted nanotherapy for oral cancer treatment with enhanced efficacy and survival rate.

The Beneficial Effects of Soybean Proteins and Peptides on Chronic Diseases

With lifestyle changes, chronic diseases have become a public health problem worldwide, causing a huge burden on the global economy. Risk factors associated with chronic diseases mainly include abdominal obesity, insulin resistance, hypertension, dyslipidemia, elevated triglycerides, cancer, and other characteristics. Plant-sourced proteins have received more and more attention in the treatment and prevention of chronic diseases in recent years. Soybean is a low-cost, high-quality protein resource that contains 40% protein. Soybean peptides have been widely studied in the regulation of chronic diseases. In this review, the structure, function, absorption, and metabolism of soybean peptides are introduced briefly. The regulatory effects of soybean peptides on a few main chronic diseases were also reviewed, including obesity, diabetes mellitus, cardiovascular diseases (CVD), and cancer. We also addressed the shortcomings of functional research on soybean proteins and peptides in chronic diseases and the possible directions in the future.

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.

Lunasin as a Promising Plant-Derived Peptide for Cancer Therapy

Cancer has become one of the main public health problems worldwide, demanding the development of new therapeutic agents that can help reduce mortality. Lunasin is a soybean peptide that has emerged as an attractive option because its preventive and therapeutic actions against cancer. In this review, we evaluated available research on lunasin’s structure and mechanism of action, which should be useful for the development of lunasin-based therapeutic products. We described data on its primary, secondary, tertiary, and possible quaternary structure, susceptibility to post-translational modifications, and structural stability. These characteristics are important for understanding drug activity and characterizing lunasin products. We also provided an overview of research on lunasin pharmacokinetics and safety. Studies examining lunasin’s mechanisms of action against cancer were reviewed, highlighting reported activities, and known molecular partners. Finally, we briefly discussed commercially available lunasin products and potential combination therapeutics.

Health Benefits of Cereal Grain- and Pulse-Derived Proteins

Pulses and whole grains are considered staple foods that provide a significant amount of calories, fibre and protein, making them key food sources in a nutritionally balanced diet. Additionally, pulses and whole grains contain many bioactive compounds such as dietary fibre, resistant starch, phenolic compounds and mono- and polyunsaturated fatty acids that are known to combat chronic disease. Notably, recent research has demonstrated that protein derived from pulse and whole grain sources contains bioactive peptides that also possess disease-fighting properties. Mechanisms of action include inhibition or alteration of enzyme activities, vasodilatation, modulation of lipid metabolism and gut microbiome and oxidative stress reduction. Consumer demand for plant-based proteins has skyrocketed primarily based on the perceived health benefits and lower carbon footprint of consuming foods from plant sources versus animal. Therefore, more research should be invested in discovering the health-promoting effects that pulse and whole grain proteins have to offer.

Beneficial Effects of Soybean-Derived Bioactive Peptides

Peptides present in foods are involved in nutritional functions by supplying amino acids; sensory functions related to taste or solubility, emulsification, etc.; and bioregulatory functions in various physiological activities. In particular, peptides have a wide range of physiological functions, including as anticancer agents and in lowering blood pressure and serum cholesterol levels, enhancing immunity, and promoting calcium absorption. Soy protein can be partially hydrolyzed enzymatically to physiologically active soy (or soybean) peptides (SPs), which not only exert physiological functions but also help amino acid absorption in the body and reduce bitterness by hydrolyzing hydrophobic amino acids from the C- or N-terminus of soy proteins. They also possess significant gel-forming, emulsifying, and foaming abilities. SPs are expected to be able to prevent and treat atherosclerosis by inhibiting the reabsorption of bile acids in the digestive system, thereby reducing blood cholesterol, low-density lipoprotein, and fat levels. In addition, soy contains blood pressure-lowering peptides that inhibit angiotensin-I converting enzyme activity and antithrombotic peptides that inhibit platelet aggregation, as well as anticancer, antioxidative, antimicrobial, immunoregulatory, opiate-like, hypocholesterolemic, and antihypertensive activities. In animal models, neuroprotective and cognitive capacity as well as cardiovascular activity have been reported. SPs also inhibit chronic kidney disease and tumor cell growth by regulating the expression of genes associated with apoptosis, inflammation, cell cycle arrest, invasion, and metastasis. Recently, various functions of soybeans, including their physiologically active functions, have been applied to health-oriented foods, functional foods, pharmaceuticals, and cosmetics. This review introduces some current results on the role of bioactive peptides found in soybeans related to health functions.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

Anticancer property of Hemp Bioactive Peptides in Hep3B liver cancer cells through Akt/GSK3β/β-catenin signaling pathway

Foodborne protein hydrolysates exhibit biological activity that may be therapeutic in a number of human disease settings. Hemp peptides (HP) generated by controlled hydrolysis of hemp proteins have a number of health benefits and are of pharmaceutical value. In the present study, we produce small molecular weight HP from hemp seed and investigate its anticancer properties in Hep3B human liver cancer cells. We demonstrate that HP treatment increased apoptosis, reduced cell viability, and reduced cell migration in Hep3B human liver cancer cells without affecting the normal liver cell line L02. We correlate these phenotypes with increased cellular ROS levels, upregulation of cleaved caspase 3 and Bad, and downregulation of antiapoptotic Bcl-2. HP treatment led to increased Akt and GSK-3β phosphorylation, with subsequent downregulation of β-catenin, suggesting β-catenin signaling modulation as a critical mechanism by which HP exhibits anticancer properties. Our findings suggest HP are of potential therapeutic interest for liver cancer treatment.

Physicochemical and structural properties of lunasin revealed by spectroscopic, chromatographic and molecular dynamics approaches

Lunasin is a 43-amino acid peptide from seeds and grains with bioavailability in humans and potent chemotherapeutic action against several cancer cell lines. Here, we investigate new information about the physicochemical and structural properties of lunasin using circular dichroism (CD), fluorescence spectroscopy, electrospray ionization-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS), size exclusion chromatography (SEC), molecular dynamics (MD), and bioinformatics. CD analysis and disorder prediction obtained by PONDR indicate that lunasin has a mostly unordered structure. Double wavelength [θ]222nm x [θ]200nm plot data suggests that lunasin is an intrinsically disordered peptide (IDP) in a pre-molten globule-like (PMG-like) state, while CD spectrum deconvolution and MD simulation indicate small β-strand content. The presence of residual structure was supported by loss of CD signal at 222 nm after treatment with urea and by increasing fluorescence emission upon bis-ANS binding. Lunasin also demonstrated stability to heating up to the temperature of 100 °C, as verified by CD. MD and CD analyses in the presence of TFE and MoRFpred prediction indicated the helix propensity of lunasin. ESI-IMS-MS data revealed that lunasin shows a propensity to form disulfide bonds at the conditions used. MD data also indicated that disulfide bond formation affects the adopted structure, showing a possible role of aspartyl-end in structure stabilization and compaction. In conclusion, our data support a characterization of lunasin as a peptide with an intrinsic disorder in a PMG-like state and reveal new aspects about its structural stability and plasticity, as well as the effects of disulfide bond formation and electrostatic attractions.

Inhibitory Effects of Peptide Lunasin in Colorectal Cancer HCT-116 Cells and Their Tumorsphere-Derived Subpopulation

The involvement of cancer stem-like cells (CSC) in the tumor pathogenesis has profound implications for cancer therapy and chemoprevention. Lunasin is a bioactive peptide from soybean and other vegetal sources with proven protective activities against cancer and other chronic diseases. The present study focused on the cytotoxic effect of peptide lunasin in colorectal cancer HCT-116 cells, both the bulk tumor and the CSC subpopulations. Lunasin inhibited the proliferation and the tumorsphere-forming capacity of HCT-116 cells. Flow cytometry results demonstrated that the inhibitory effects were related to apoptosis induction and cell cycle-arrest at G1 phase. Moreover, lunasin caused an increase in the sub-GO/G1 phase of bulk tumor cells, linked to the apoptotic events found. Immunoblotting analysis further showed that lunasin induced apoptosis through activation of caspase-3 and cleavage of PARP, and could modulate cell cycle progress through the cyclin-dependent kinase inhibitor p21. Together, these results provide new evidence on the chemopreventive activity of peptide lunasin on colorectal cancer by modulating both the parental and the tumorsphere-derived subsets of HCT-116 cells.

Silk fibroin peptide suppresses proliferation and induces apoptosis and cell cycle arrest in human lung cancer cells

Silkworm cocoon was recorded to cure carbuncle in the Compendium of Materia Medica. Previous studies have demonstrated that the supplemental silk protein sericin exhibits anticancer activity. In the present study, we investigated the effects of silk fibroin peptide (SFP) extracted from silkworm cocoons against human lung cancer cells in vitro and in vivo and its possible anticancer mechanisms. SFP that we prepared had high content of glycine (~ 30%) and showed a molecular weight of ~ 10 kDa. Intragastric administration of SFP (30 g/kg/d) for 14 days did not affect the weights, vital signs, routine blood indices, and blood biochemical parameters in mice. MTT assay showed that SFP dose-dependently inhibited the growth of human lung cancer A549 and H460 cells in vitro with IC₅₀ values of 9.921 and 9.083 mg/mL, respectively. SFP also dose-dependently suppressed the clonogenic activity of the two cell lines. In lung cancer H460 xenograft mice, intraperitoneal injection of SFP (200 or 500 mg/kg/d) for 40 days significantly suppressed the tumor growth, but did not induce significant changes in the body weight. We further examined the effects of SFP on cell cycle and apoptosis in H460 cells using flow cytometry, which revealed that SFP-induced cell cycle arrest at the S phase, and then promoted cell apoptosis. We demonstrated that SFP (20-50 mg/mL) dose-dependently downregulates Bcl-2 protein expression and upregulates Bax protein in H460 cells during cell apoptosis. The results suggest that SFP should be studied further as a novel therapeutic agent for the treatment of lung cancer.

Current state of art after twenty years of the discovery of bioactive peptide lunasin

Non-communicable diseases have become the medical challenge of the 21st century because of their high incidence and mortality rates. Accumulating evidence has suggested that the modulation of diet and other lifestyle habits is the best strategy for the prevention of these diseases. An increasing number of dietary compounds have been found to exert health promoting benefits beyond their nutritional effects. Among them, lunasin is considered one of the most studied bioactive peptides. Since its discovery in soybean twenty years ago, many researchers around the world have focused their studies on demonstrating the chemopreventive and chemotherapeutic activity of lunasin. Moreover, in the last years, promising protective effects of this peptide against hypercholesterolemia, obesity, metabolic syndrome and associated cardiovascular disorders, and inflammatory and immune-regulated diseases have been described. This review summarizes recent remarkable advances on the use of peptide lunasin as a potential functional ingredient to provide health benefits. Moreover, novel aspects related to the influence of lunasin's digestion and bioavailability, the mechanisms of action proposed to explain the underlying biological properties, and the incorporation of this peptide into nutritional supplements are critically discussed.

Molecular targets and mechanisms of bioactive peptides against metabolic syndromes

Bioactive peptides are present in all living organisms and have critical roles ranging from protection against infection as the key element of innate immunity, regulating blood pressure and glucose levels, to reducing signs of ageing by killing senescent cells. Bioactive peptides are also encrypted within food protein sequences that can be released during proteolysis or food processing. These specific food protein fragments are reported to have potential for improving human health and preventing metabolic diseases through their impact on inflammation, blood pressure, obesity, and type-2 diabetes. This review mainly focuses on the molecular targets and the underlying mechanisms of bioactive peptides against various metabolic syndromes including inflammation, high blood pressure, obesity, and type-2 diabetes, to provide new insights and perspectives on the potential of bioactive peptides for management of metabolic syndromes.

The effect of the type of dietary protein on the development of ovarian cancer

We evaluated whether different dietary protein qualities (isocaloric diets involving animal (casein) or plant protein (soy protein) could inhibit the ovarian cancer growth in mice and improve their prognosis and whether chemotherapy had different tumor reducing effects on these mice. In the mice of the 20% plant protein group, the ovarian cancer growth at 5 weeks after tumor implantation was clearly reduced in comparison to the mice in the 20% animal protein group (p< 0.001). The serum levels of insulin and IGF-1 levels were both lower in the mice of the 20% plant protein group than in the mice of the 20% animal protein group (p<0.001 and p<0.01, respectively). Immunohistochemistry revealed that the level of eukaryotic initiation factor 4E-binding protein 1 (p-4EBP1) activity―one of the major downstream effectors of the mTOR pathway ―of the plant protein group was significantly weaker than that of the animal protein group (p<0.001). The prognosis of the 20% plant protein group was better than that of the 20% animal protein group (log-rank test, p=0.0062). The ovarian cancer growth in the 20% plant protein plus cisplatin treatment group was not significantly reduced in comparison to the 20% animal protein plus cisplatin treatment group. Our findings suggest that a diet high in plant protein reduces the growth of human ovarian cancer cells in mice compared to a diet high in animal protein, ―possibly through the lack of activation of the IGF/Akt/mTOR pathway, and leads to a better prognosis with or without cisplatin treatment.

Updating the research on the chemopreventive and therapeutic role of the peptide lunasin

Chronic diseases have become the medical challenge of the 21st century because of their high incidence and mortality rates. Modulation of diet and lifestyle habits is considered as the best strategy for the prevention of these disorders. Health promoting benefits beyond their nutritional effects have been described for multiple dietary compounds. Among these compounds, the peptide lunasin is considered as one of the most promising. Naturally present in soybean, lunasin has been extensively studied in the last two decades because of its potential against chronic diseases such as cancer, cardiovascular and immunological disorders. The purpose of this article is to summarise the evidence on the presence of lunasin in soybean and derived foods, and its bioavailability once it is orally ingested. The protective and therapeutic effects of this peptide against cancer, oxidative stress, inflammation, and high cholesterol levels as well as the molecular mechanisms of action involved in these effects are also described in this review. © 2017 Society of Chemical Industry.

Lunasin is a novel therapeutic agent for targeting melanoma cancer stem cells

Recent studies provide compelling evidence that melanoma is initiated and maintained by a small population of malignant cells called cancer-initiating cells (CICs) that exhibit stem-cell-like properties. Observations that CICs have a distinct biology when compared to that of the bulk tumor cells and, importantly, are resistant to chemotherapies and radiation, suggest that CICs are involved in invasion, metastasis, and ultimately relapse. Lunasin, a bioactive peptide present in soybean, has both chemopreventive activity and chemotherapeutic activity against multiple cancer types. In this study, we tested the potential of Lunasin to specifically target CICs in melanoma tumor cell populations. In vitro studies using human melanoma cell lines showed that Lunasin treatment decreased the size of a subpopulation of melanoma cells expressing the surrogate CIC marker, Aldehyde Dehydrogenase, concomitant with a reduction in the ability to form colonies in soft agar assays, and reduced tumor growth in mouse xenografts. Similarly, Lunasin inhibited colony formation by isolated melanoma CICs in soft agar and reduced oncosphere formation in vitro and substantially inhibited tumor growth in mouse xenografts. Mechanistic studies revealed that Lunasin treatment of isolated melanoma CICs induced expression of the melanocyte-associated differentiation markers Tyrosinase and Microphthalmia-associated Transcription Factor concomitant with reduced expression of the stemness factor NANOG. These findings document for the first time that Lunasin has significant therapeutic activity against melanoma by specifically targeting melanoma CICs, and inducing a more differentiated, non-CIC phenotype. Thus, Lunasin may represent a novel therapeutic option for both chemoresistant and advanced metastatic melanoma management.

The soy-derived peptide Lunasin inhibits invasive potential of melanoma initiating cells

Lunasin is a 44 amino acid peptide with multiple functional domains including an aspartic acid tail, an RGD domain, and a chromatin-binding helical domain. We recently showed that Lunasin induced a phenotype switch of cancer initiating cells (CIC) out of the stem compartment by inducing melanocyte-associated differentiation markers while simultaneously reducing stem-cell-associated transcription factors. In the present study, we advance the hypothesis that Lunasin can reduce pools of melanoma cells with stem cell-like properties, and demonstrate that Lunasin treatment effectively inhibits the invasive potential of CICs in vitro as well as in vivo in a mouse experimental metastasis model. Mice receiving Lunasin treatment had significantly reduced pulmonary colonization after injection of highly metastatic B16-F10 melanoma cells compared to mice in the control group. Mechanistic studies demonstrate that Lunasin reduced activating phosphorylations of the intracellular kinases FAK and AKT as well as reduced histone acetylation of lysine residues in H3 and H4 histones. Using peptides with mutated activity domains, we functionally demonstrated that the RGD domain is necessary for Lunasin uptake and its ability to inhibit oncosphere formation by CICs, thus confirming that Lunasin's ability to affect CICs is at least in part due to the suppression of integrin signaling. Our studies suggest that Lunasin represents a unique anticancer agent that could be developed to help prevent metastasis and patient relapse by reducing the activity of CICs which are known to be resistant to current chemotherapies.

Antioxidant Activity of Zein Hydrolysates from Zea Species and Their Cytotoxic Effects in a Hepatic Cell Culture

In recent years, food proteins with bioactivity have been studied for cancer treatment. Zein peptides have shown an important set of bioactivities. This work compares the cytotoxic activity of zein hydrolyzed, extracted from four Zea species: teosinte, native, hybrid, and transgenic (Teo, Nat, Hyb, and HT) in a hepatic cell culture. Zein fraction was extracted, quantified, and hydrolyzed. Antioxidant capacity and cytotoxicity assays were performed on HepG2 cells. The levels of expression of caspase 3, 8, and 9 were evaluated in zein-treated cell cultures. Zea parviglumis showed the highest zein content (46.0 mg/g) and antioxidant activity (673.40 TE/g) out of all native zeins. Peptides from Hyb and HT showed high antioxidant activity compared to their native counterparts (1055.45 and 724.32 TE/g, respectively). Cytotoxic activity was observed in the cell culture using peptides of the four Zea species; Teo and Nat (IC50: 1781.63 and 1546.23 ng/mL) had no significant difference between them but showed more cytotoxic activity than Hyb and HT (IC50: 1252.25 and 1155.56 ng/mL). Increased expression of caspase 3 was observed in the peptide-treated HepG2 cells (at least two-fold more with respect to the control sample). These data indicate the potential for zein peptides to prevent or treat cancer, possibly by apoptosis induction.

Anti-Cancer Activity of Maize Bioactive Peptides

Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derivative food products has been associated with a reduced risk of various types of cancer. The main biomolecules in cereals include proteins, peptides, and amino acids, all of which are present in different quantities within the grain. Some of these peptides possess nutraceutical properties and exert biological effects that promote health and prevent cancer. In this review, we report the current status and advances in knowledge regarding the bioactive properties of maize peptides, such as antioxidant, antihypertensive, hepatoprotective, and anti-tumor activities. We also highlight the potential biological mechanisms through which maize bioactive peptides exert anti-cancer activity. Finally, we analyze and emphasize the potential applications of maize peptides.

Proteomics and metabolomics-driven pathway reconstruction of mung bean for nutraceutical evaluation

Mung bean is a legume crop which has a various health-promoting effects. Although rich flavonoids are reported to be responsible for its biological activities, little is known about other nutrients that may potentiate the activities. To obtain information on mung bean nutritional properties, gel-free/label-free proteomic analysis and metabolomic profiling were combined. Pathway reconstruction detected that amino acid metabolism is more active in flesh. Coat contained wider variety of lipids and phenolic acids/flavonoids than flesh. Among the compounds detected in coat, sphingolipids, arachidonic acid, and prostaglandin E2 are compounds which are related to immune response induction. Furthermore, identification of prostaglandin F2α added scientific support to empirical validity of mung bean usage. The abundance of bioactive compounds such as naringenin, which can be metabolized into vitexin, varied among cultivars. These results suggest that lipids together with flavonoids might be potential responsible compounds for biological activity of mung bean coat and flesh.

The soy-derived peptide Vglycin inhibits the growth of colon cancer cells in vitro and in vivo

Vglycin, a novel natural polypeptide isolated from pea seeds, possesses antidiabetic properties. Our previous studies have shown that Vglycin can induce the differentiation of human colon adenocarcinoma cells. We aimed to determine the anticancer activity of Vglycin against colon cancer cells and to elucidate related apoptosis-inducing mechanisms. Treatment with purified Vglycin significantly reduced growth, viability, and colony formation of CT-26, SW480, and NCL-H716 colon cancer cells in a dose-dependent manner while down-regulating the expression of proliferating cell nuclear antigen. Mouse xenograft studies showed a 38% inhibition of colon cancer growth in mice treated with Vglycin (20 mg/kg/day) at day 21. Furthermore, the potential mechanisms involved in Vglycin-induced cell apoptosis were examined using cell cycle studies, ultrastructural examination, as well as apoptosis-associated pathway analysis. The results showed that Vglycin significantly promoted apoptosis and G1/S phase cell cycle arrest. As revealed by Western blot, the expression of CDK2 and Cyclin D1 was down-regulated in all three Vglycin-treated colon cancer cells, indicating that the CDK2/Cyclin D1 cell cycle pathway involved in the initiation and progression of colon cancer. Moreover, the inhibition of Vglycin-induced cell proliferation in colon cancer cells was accompanied by alteration of the expression levels of the apoptosis-related proteins Bax, Bcl-2 and Mcl-1, and an increase of caspase-3 activity. Together, our results suggest that Vglycin may be another plant-derived peptide that suppresses colon cancer, supporting the continued investigation of Vglycin as therapeutic agent for colon cancer. Impact statement The antidiabetic properties and the capability of inducing differentiation of human colon adenocarcinoma cells of Vglycin have been reported in our previous studies. However, the anticancer potential of Vglycin on colon cancer cells and its possible related mechanisms were still unknown. In this study, we found that Vglycin could reduce growth, viability, and colony formation or colony size of CT-26, SW480, and NCL-H716 colon cancer cells. Moreover, Vglycin decreased tumor volume by 38% in xenograft mice transplanted with CT-26 cells. The mechanisms of these phenomena may be due to the down-regulated CDK2 and Cyclin D1, G1/S phase cell cycle arrest, and the dysregulated expression of Bax, Bcl-2, and Mcl-1. The findings highlight the anticancer potential of Vglycin against colon cancer cells, and suggest Vglycin may be another colon cancer potential suppressive component of plant-derived peptides.

Validation of syngeneic mouse models of melanoma and non-small cell lung cancer for investigating the anticancer effects of the soy-derived peptide Lunasin

Background : Lunasin is a naturally occurring peptide present in soybean that has both chemopreventive and therapeutic activities that can prevent cellular transformation and inhibit the growth of several human cancer types. Recent studies indicate that Lunasin has several distinct potential modes of action including suppressing integrin signaling and epigenetic effects driven by modulation of histone acetylation. In addition to direct effects on cancer cells, Lunasin also has effects on innate immunity that may contribute to its ability to inhibit tumor growth in vivo. Methods: Standard assays for cell proliferation and colony formation were used to assess Lunasin's in vitro activity against murine Lewis lung carcinoma (LLC) and B16-F0 melanoma cells.  Lunasin's in vivo activity was assessed by comparing the growth of tumors initiated by subcutaneous implantation of LLC or B16-F0 cells in Lunasin-treated and untreated C57BL/6 mice. Results: Lunasin was found to inhibit growth of murine LLC cells and murine B16-F0 melanoma cells in vitro and in wild-type C57BL/6 mice.  The effects of Lunasin in these two mouse models were very similar to those previously observed in studies of human non-small cell lung cancer and melanoma cell lines. Conclusions: We have now validated two established syngeneic mouse models as being responsive to Lunasin treatment.  The validation of these two in vivo syngeneic models will allow detailed studies on the combined therapeutic and immune effects of Lunasin in a fully immunocompetent mouse model.

Validation of syngeneic mouse models of melanoma and non-small cell lung cancer for investigating the anticancer effects of the soy-derived peptide Lunasin

Background: Lunasin is a naturally occurring peptide present in soybean that has both chemopreventive and therapeutic activities that can prevent cellular transformation and inhibit the growth of several human cancer types. Recent studies indicate that Lunasin has several distinct potential modes of action including suppressing integrin signaling and epigenetic effects driven by modulation of histone acetylation. In addition to direct effects on cancer cells, Lunasin also has effects on innate immunity that may contribute to its ability to inhibit tumor growth in vivo.

Methods: Standard assays for cell proliferation and colony formation were used to assess Lunasin’s in vitro activity against murine Lewis lung carcinoma (LLC) and B16-F0 melanoma cells.  Lunasin’s in vivo activity was assessed by comparing the growth of tumors initiated by subcutaneous implantation of LLC or B16-F0 cells in Lunasin-treated and untreated C57BL/6 mice.

Results: Lunasin was found to inhibit growth of murine LLC cells and murine B16-F0 melanoma cells in vitro and in wild-type C57BL/6 mice.  The effects of Lunasin in these two mouse models were very similar to those previously observed in studies of human non-small cell lung cancer and melanoma cell lines.

Conclusions: We have now validated two established syngeneic mouse models as being responsive to Lunasin treatment.  The validation of these two in vivo syngeneic models will allow detailed studies on the combined therapeutic and immune effects of Lunasin in a fully immunocompetent mouse model.

Lunasin sensitivity in non-small cell lung cancer cells is linked to suppression of integrin signaling and changes in histone acetylation

Lunasin is a plant derived bioactive peptide with both cancer chemopreventive and therapeutic activity. We recently showed lunasin inhibits non-small cell lung cancer (NSCLC) cell proliferation in a cell-line-specific manner. We now compared the effects of lunasin treatment of lunasin-sensitive (H661) and lunasin-insensitive (H1299) NSCLC cells with respect to lunasin uptake, histone acetylation and integrin signaling. Both cell lines exhibited changes in histone acetylation, with H661 cells showing a unique increase in H4K16 acetylation. Proximity ligation assays demonstrated lunasin interacted with integrins containing αv, α5, β1 and β3 subunits to a larger extent in the H661 compared to H1299 cells. Moreover, lunasin specifically disrupted the interaction of β1 and β3 subunits with the downstream signaling components phosphorylated Focal Adhesion Kinase (pFAK), Kindlin and Intergrin Linked Kinase in H661 cells. Immunoblot analyses demonstrated lunasin treatment of H661 resulted in reduced levels of pFAK, phosphorylated Akt and phosphorylated ERK1/2 whereas no changes were observed in H1299 cells. Silencing of αv expression in H661 cells confirmed signaling through integrins containing αv is essential for proliferation. Moreover, lunasin was unable to further inhibit proliferation in αv-silenced H661 cells. This indicates antagonism of integrin signaling via αv-containing integrins is an important component of lunasin’s mechanism of action.