Ascorbic Acid in Colon Cancer: From the Basic to the Clinical Applications

Dual Role of Vitamin C-Encapsulated Liposomal Berberine in Effective Colon Anticancer Immunotherapy

The aim of the study was to achieve effective colon anticancer immunotherapy using the alkaloid berberine. In the presented paper we attempt to develop a formulation of berberine loaded into liposomal carriers using the vitamin C gradient method, characterized by efficient drug encapsulation, high stability during long-term storage, low drug release in human plasma with specific cytotoxicity towards colon cancer cells. Liposomal berberine was responsible for the induction of oxidative stress, the presence of Ca2+ ions in the cytosol, the reduction of Δψm, and ATP depletion with a simultaneous lack of caspase activity. Moreover, treatment with liposomal berberine led to CRT exposure on the surface of cancer cells, extracellular ATP, and HMGB1 release. The above-described mechanism of action was most likely associated with ICD induction, contributing to the increased number of phagocytic cancer cells. We have shown that cancer cells treated with liposomal berberine were phagocytosed more frequently by macrophages compared to the untreated cancer cells. What is more, we have shown that macrophage pre-treatment with liposomal berberine led to a 3-fold change in the number of phagocytosed SW620 cancer cells. The obtained results provide new insights into the role of berberine in maintaining the immune response against colorectal cancer.

Integrated gut microbiota and metabolome analysis reveals the mechanism of Xiaoai Jiedu recipe in ameliorating colorectal cancer

Introduction

Xiaoai Jiedu recipe (XJR), a classical prescription of traditional Chinese medicine (TCM), has been clinically proven to be effective in ameliorating colorectal cancer (CRC). However, its exact mechanism of action is still elusive, limiting its clinical application and promotion to a certain extent. This study aims to evaluate the effect of XJR on CRC and further illustrate mechanism underlying its action.

Methods

We investigated the anti-tumor efficacy of XJR in vitro and vivo experiments. An integrated 16S rRNA gene sequencing and UPLC-MS based metabolomics approach were performed to explore possible mechanism of XJR anti-CRC on the gut microbiota and serum metabolic profiles. The correlation between altered gut microbiota and disturbed serum metabolites was investigated using Pearson's correlation analysis.

Results

XJR effectively displayed anti-CRC effect both in vitro and in vivo. The abundance of aggressive bacteria such as Bacteroidetes, Bacteroides, and Prevotellaceae decreased, while the levels of beneficial bacteria increased (Firmicutes, Roseburia, and Actinobacteria). Metabolomics analysis identified 12 potential metabolic pathways and 50 serum metabolites with different abundances possibly affected by XJR. Correlation analysis showed that the relative abundance of aggressive bacteria was positively correlated with the levels of Arachidonic acid, Adrenic acid, 15(S)-HpETE, DL-Arginine, and Lysopc 18:2, which was different from the beneficial bacteria.

Discussion

The regulation of gut microbiota and related metabolites may be potential breakthrough point to elucidate the mechanism of XJR in the treatment of the CRC. The strategy employed would provide theoretical basis for clinical application of TCM.

Oxidative Status Determines the Cytotoxicity of Ascorbic Acid in Human Oral Normal and Cancer Cells

Oral squamous cell carcinoma (OSCC) can arise anywhere in the oral cavity. OSCC's molecular pathogenesis is complex, resulting from a wide range of events that involve the interplay between genetic mutations and altered levels of transcripts, proteins, and metabolites. Platinum-based drugs are the first-line treatment for OSCC; however, severe side-effects and resistance are challenging issues. Thus, there is an urgent clinical need to develop novel and/or combinatory therapeutics. In this study, we investigated the cytotoxic effects of pharmacological concentrations of ascorbate on two human oral cell lines, the oral epidermoid carcinoma meng-1 (OECM-1) cell and the Smulow-Glickman (SG) human normal gingival epithelial cell. Our study examined the potential functional impact of pharmacological concentrations of ascorbates on the cell-cycle profiles, mitochondrial-membrane potential, oxidative response, the synergistic effect of cisplatin, and the differential responsiveness between OECM-1 and SG cells. Two forms of ascorbate, free and sodium forms, were applied to examine the cytotoxic effect and it was found that both forms had a similar higher sensitivity to OECM-1 cells than to SG cells. In addition, our study data suggest that the determinant factor of cell density is important for ascorbate-induced cytotoxicity in OECM-1 and SG cells. Our findings further revealed that the cytotoxic effect might be mediated through the induction of mitochondrial reactive oxygen species (ROS) generation and the reduction in cytosolic ROS generation. The combination index supported the agonistic effect between sodium ascorbate and cisplatin in OECM-1 cells, but not in SG cells. In summary, our current findings provide supporting evidence for ascorbate to serve as a sensitizer for platinum-based treatment of OSCC. Hence, our work provides not only repurposing of the drug, ascorbate, but also an opportunity to decrease the side-effects of, and risk of resistance to, platinum-based treatment for OSCC.

Overcoming EGFR Resistance in Metastatic Colorectal Cancer Using Vitamin C: A Review

Targeted monoclonal antibody therapy against Epidermal Growth Factor Receptor (EGFR) is a leading treatment modality against metastatic colorectal cancer (mCRC). However, with the emergence of KRAS and BRAF mutations, resistance was inevitable. Cells harboring these mutations overexpress Glucose Transporter 1 (GLUT1) and sodium-dependent vitamin C transporter 2 (SVCT2), which enables intracellular vitamin C transport, leading to reactive oxygen species generation and finally cell death. Therefore, high dose vitamin C is proposed to overcome this resistance. A comprehensive search strategy was adopted using Pubmed and MEDLINE databases (up to 11 August 2022). There are not enough randomized clinical trials to support its use in the clinical management of mCRC, except for a subgroup analysis from a phase III study. High dose vitamin C shows a promising role in overcoming EGFR resistance in mCRC with wild KRAS mutation with resistance to anti-epidermal growth factor inhibitors and in patients with KRAS and BRAF mutations.

Identification of Agents That Ameliorate Hyperphosphatemia-Suppressed Myogenin Expression Involved in the Nrf2/p62 Pathway in C2C12 Skeletal Muscle Cells

Hyperphosphatemia can occur as a result of reduced phosphate (P_i) excretion in cases of kidney dysfunction, which can induce muscle wasting and suppress myogenic differentiation. Higher P_i suppresses myogenic differentiation and promotes muscle atrophy through canonical (oxidative stress-mediated) and noncanonical (p62-mediated) activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. However, the crosstalk between myogenin and Nrf2/p62 and potential drug(s) for the regulation of myogenin expression needed to be addressed. In this study, we further identified that myogenin may negatively regulate Nrf2 and p62 protein levels in the mouse C2C12 muscle cell line. In the drug screening analysis, we identified N-acetylcysteine, metformin, phenformin, berberine, 4-chloro-3-ethylphenol, cilostazol, and cilomilast as ameliorating the induction of Nrf2 and p62 expression and reduction in myogenin expression that occur due to high P_i. We further elucidated that doxorubicin and hydrogen peroxide reduced the amount of myogenin protein mediated through the Kelch-like ECH-associated protein 1/Nrf2 pathway, differently from the mechanism of high Pi. The dual functional roles of L-ascorbic acid (L-AA) were found to be dependent on the working concentration, where concentrations below 1 mM L-AA reversed the effect of high P_i on myogenin and those above 1 mM L-AA had a similar effect of high P_i on myogenin when used alone. L-AA exacerbated the effect of hydrogen peroxide on myogenin protein and had no further effect of doxorubicin on myogenin protein. In summary, our results further our understanding of the crosstalk between myogenin and Nrf2, with the identification and verification of several potential drugs that can be applied in rescuing the decline of myogenin due to high P_i in muscle cells.

Metabolomic profiling identifies biomarkers and metabolic impacts of surgery for colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common malignant tumors with recurrence and metastasis after surgical resection. This study aimed to identify the physiological changes after surgery and explore metabolites and metabolic pathways with potential prognostic value for CRC.

Methods

An ultra-high-performance liquid chromatography Q-exactive mass spectrometry was used to profile serum metabolites from 67 CRC patients and 50 healthy volunteers. Principal component analysis (PCA) and orthogonal projections to latent structures-discriminant analysis were used to distinguish the internal characteristics of data in different groups. Multivariate statistics were compiled to screen the significant metabolites and metabolic pathways.

Result

A total of 180 metabolites were detected. Under the conditions of variable importance in projection >1 and p-value <0.05, 46 differentially expressed metabolites were screened for further pathway enrichment analysis. Based on the Kyoto Encyclopedia of Genes and Genomes database and Small Molecule Pathway Database, three metabolic pathways—arginine and proline metabolism, ascorbate and aldarate metabolism, and phenylalanine metabolism—were significantly altered after surgical resection and identified as associated with the removal of CRC. Notably, gamma-linolenic acid was upregulated in the CRC preoperative patients compared with those in healthy volunteers but returned to healthy levels after surgery.

Conclusion

Through serum-based metabolomics, our study demonstrated the differential metabolic characteristics in CRC patients after surgery compared with those before surgery. Our results suggested that metabonomic analysis may be a powerful method for exploring physiological alterations in CRC patients after surgery as well as a useful tool for identifying candidate biomarkers and monitoring disease recurrence.

In Vitro Cell Density Determines the Sensitivity of Hepatocarcinoma Cells to Ascorbate

Hepatocellular carcinoma (HCC) is the primary histological subtype of liver cancer, and its incidence rates increase with age. Recently, systemic therapies, such as immune checkpoint inhibitors, monoclonal antibodies, and tyrosine kinase inhibitors (TKIs), have been more beneficial than conventional therapies for treating HCC. Nonetheless, the prognosis of late-stage HCC remains dismal because of its high recurrence rates, even with substantial advances in current therapeutic strategies. A new treatment, such as a combination of current systemic therapies, is urgently required. Therefore, we adopted a repurposing strategy and tried to combine ascorbate with TKIs, including lenvatinib and regorafenib, in HepG2 and Hep3B cells. We investigated the potential functional impact of pharmacological concentrations of ascorbate on the cell-cycle profiles, mitochondrial membrane potential, oxidative response, synergistic effects of lenvatinib or regorafenib, and differential responsiveness between HepG2 and Hep3B cells. Our data suggest that the relative level of cell density is an important determinant for ascorbate cytotoxicity in HCC. Furthermore, the data also revealed that the cytotoxic effect of pharmacological concentrations of ascorbate might not be mediated via our proposed elevation of ROS generation. Ascorbate might be involved in redox homeostasis to enhance the efficacy of TKIs in HepG2 and Hep3B cells. The synergistic effects of ascorbate with TKIs (lenvatinib and regorafenib) support their potential as an adjuvant for HCC targeted TKI therapy. This research provides a cheap and new combinatory therapy for HCC treatment.

Phenolic Compounds Promote Diversity of Gut Microbiota and Maintain Colonic Health

The role of non-energy-yielding nutrients on health has been meticulously studied, and the evidence shows that a compound can exert significant effects on health even if not strictly required by the organism. Phenolic compounds are among the most widely studied molecules that fit this description; they are found in plants as secondary metabolites and are not required by humans for growth or development, but they can influence a wide array of processes that modulate health across multiple organs and systems. The lower gastrointestinal tract is a prime site of action of phenolic compounds, namely, by their effects on gut microbiota and colonic health. As with humans, phenolic compounds are not required by most bacteria but can be substrates of others; in fact, some phenolic compounds exert antibacterial actions. A diet rich in phenolic compounds can lead to qualitative and quantitative effects on gut microbiota, thereby inducing indirect health effects in mammals through the action of these microorganisms. Moreover, phenolic compounds may be fermented by the gut microbiota, thereby modulating the compounds bioactivity. In the colon, phenolic compounds promote anti-inflammatory, anti-oxidant and antiproliferative actions. The aim of the present review is to highlight the role of phenolic compounds on maintaining or restoring a healthy microbiota and overall colonic health. Mechanisms of action that substantiate the reported evidence will also be discussed.

Viruses in colorectal cancer

Increasing evidence suggests that microorganisms might represent at least highly interesting cofactors in colorectal cancer (CRC) oncogenesis and progression. Still, associated mechanisms, specifically in colonocytes and their microenvironmental interactions, are still poorly understood. Although, currently, at least seven viruses are being recognized as human carcinogens, only three of these – Epstein–Barr virus (EBV), human papillomavirus (HPV) and John Cunningham virus (JCV) – have been described, with varying levels of evidence, in CRC. In addition, cytomegalovirus (CMV) has been associated with CRC in some publications, albeit not being a fully acknowledged oncovirus. Moreover, recent microbiome studies set increasing grounds for new hypotheses on bacteriophages as interesting additional modulators in CRC carcinogenesis and progression. The present Review summarizes how particular groups of viruses, including bacteriophages, affect cells and the cellular and microbial microenvironment, thereby putatively contributing to foster CRC. This could be achieved, for example, by promoting several processes – such as DNA damage, chromosomal instability, or molecular aspects of cell proliferation, CRC progression and metastasis – not necessarily by direct infection of epithelial cells only, but also by interaction with the microenvironment of infected cells. In this context, there are striking common features of EBV, CMV, HPV and JCV that are able to promote oncogenesis, in terms of establishing latent infections and affecting p53‐/pRb‐driven, epithelial–mesenchymal transition (EMT)‐/EGFR‐associated and especially Wnt/β‐catenin‐driven pathways. We speculate that, at least in part, such viral impacts on particular pathways might be reflected in lasting (e.g. mutational or further genomic) fingerprints of viruses in cells. Also, the complex interplay between several species within the intestinal microbiome, involving a direct or indirect impact on colorectal and microenvironmental cells but also between, for example, phages and bacterial and viral pathogens, and further novel species certainly might, in part, explain ongoing difficulties to establish unequivocal monocausal links between specific viral infections and CRC.

Genetic Mutations and Non-Coding RNA-Based Epigenetic Alterations Mediating the Warburg Effect in Colorectal Carcinogenesis

Colorectal cancer (CRC) development is a gradual process defined by the accumulation of numerous genetic mutations and epigenetic alterations leading to the adenoma-carcinoma sequence. Despite significant advances in the diagnosis and treatment of CRC, it continues to be a leading cause of cancer-related deaths worldwide. Even in the presence of oxygen, CRC cells bypass oxidative phosphorylation to produce metabolites that enable them to proliferate and survive-a phenomenon known as the "Warburg effect". Understanding the complex glucose metabolism in CRC cells may support the development of new diagnostic and therapeutic approaches. Here we discuss the most recent findings on genetic mutations and epigenetic modulations that may positively or negatively regulate the Warburg effect in CRC cells. We focus on the non-coding RNA (ncRNA)-based epigenetics, and we present a perspective on the therapeutic relevance of critical molecules and ncRNAs mediating the Warburg effect in CRC cells. All the relevant studies were identified and assessed according to the genes and enzymes mediating the Warburg effect. The findings summarized in this review should provide a better understanding of the relevance of genetic mutations and the ncRNA-based epigenetic alterations to CRC pathogenesis to help overcome chemoresistance.

Comprehensive polar metabolomics and lipidomics profiling discriminates the transformed from the non-transformed state in colon tissue and cell lines

Colorectal cancer (CRC) is the fourth most lethal disease worldwide. Despite an urgent need for therapeutic advance, selective target identification in a preclinical phase is hampered by molecular and metabolic variations between cellular models. To foster optimal model selection from a translational perspective, we performed untargeted ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry-based polar metabolomics and lipidomics to non-transformed (CCD841-CON and FHC) and transformed (HCT116, HT29, Caco2, SW480 and SW948) colon cell lines as well as tissue samples from ten colorectal cancer patients. This unveiled metabolic signatures discriminating the transformed from the non-transformed state. Metabolites involved in glutaminolysis, tryptophan catabolism, pyrimidine, lipid and carnitine synthesis were elevated in transformed cells and cancerous tissue, whereas those involved in the glycerol-3-phosphate shuttle, urea cycle and redox reactions were lowered. The degree of glutaminolysis and lipid synthesis was specific to the colon cancer cell line at hand. Thus, our study exposed pathways that are specifically associated with the transformation state and revealed differences between colon cancer cell lines that should be considered when targeting cancer-associated pathways.

The effects and mechanisms of isoliquiritigenin loaded nanoliposomes regulated AMPK/mTOR mediated glycolysis in colorectal cancer

In this study, isoliquiritigenin (ISL) incorporated nanoliposomes were prepared and their effects on colorectal cancer (CRC) cell lines were investigated. Herein, we sought to explore the anti-cancer mechanisms of ISL loaded nanoliposomes (ISL-NLs) on AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathways mediated glycolysis. Also, the key targets such as caveolin 1 (CAV1), glucose transporters and Akt/mTOR that promote glycolysis, and are activated via the induction of α-enolase (ENO1), fructose bisphosphate aldolase A (ALDOA) and monocarboxylate transporter 4 (MCT4) expressions were also investigated. It was shown that ISL-NLs significantly suppressed the proliferation and glucose uptake of CRC cell by potentially regulating the glycolysis and lactate targets as well as pathways that formed the basis of the anti-CRC effects of ISL-NLs. The mechanism underlying this effect was further validated via the regulation of some key targets such as ENO1, ALDOA, lactate dehydrogenase A (LDHA) and MCT4 in glycolysis coupled with cellular myelocytomatosis oncogene (c-myc), hypoxia-inducible factor 1-alpha (HIF-1α) in protein kinase B/mTOR (Akt/mTOR) pathways. Moreover, the AMPK proteins were identified to be up-regulated while the lactic acid production was suppressed by ISL-NLs in the CRC cells, indicating that ISL-NLs had an inhibitory effect on AMPK mediated glycolysis and lactate production. Altogether, these results have provided insights into the mechanism underlying the key role that liposomal ISL played in the multiple inhibition of AMPK and Akt/mTOR mediated glycolysis and lactate generation, which may be regulated as the alternative metabolic pathways of CRC as well as serve as adjuvant therapy for the disease.

Gold-Based Nanoplataform for the Treatment of Anaplastic Thyroid Carcinoma: A Step Forward

Anaplastic thyroid carcinoma (ATC) is a very rare subtype of thyroid carcinoma and one of the most lethal malignancies. Poor prognosis is mainly associated with its undifferentiated nature, inoperability, and failing to respond to the typically used therapies for thyroid cancer. Photothermal Therapy (PTT) entails using light to increase tissues' temperature, leading to hyperthermia-mediated cell death. Tumours are more susceptible to heat as they are unable to dissipate it. By using functionalized gold nanoparticles (AuNPs) that transform light energy into heat, it is possible to target the heat to the tumour. This study aims to formulate ATC-targeted AuNPs able to convert near-infrared light into heat, for PTT of ATC. Different AuNPs were synthetized and coated. Size, morphology, and surface plasmon resonances band were determined. The optimized coated-AuNPs were then functionalized with ligands to assess ATC's specificity. Safety, efficacy, and selectivity were assessed in vitro. The formulations were deemed safe when not irradiated (>70% cell viability) and selective for ATC. However, when irradiated, holo-transferrin-AuNPs were the most cytotoxic (22% of cell viability). The biodistribution and safety of this formulation was assessed in vivo. Overall, this novel formulation appears to be a highly promising approach to evaluate in a very near future.

Metabolic Factors Affecting Tumor Immunogenicity: What Is Happening at the Cellular Level?

Immunotherapy has changed the treatment paradigm in multiple solid and hematologic malignancies. However, response remains limited in a significant number of cases, with tumors developing innate or acquired resistance to checkpoint inhibition. Certain "hot" or "immune-sensitive" tumors become "cold" or "immune-resistant", with resultant tumor growth and disease progression. Multiple factors are at play both at the cellular and host levels. The tumor microenvironment (TME) contributes the most to immune-resistance, with nutrient deficiency, hypoxia, acidity and different secreted inflammatory markers, all contributing to modulation of immune-metabolism and reprogramming of immune cells towards pro- or anti-inflammatory phenotypes. Both the tumor and surrounding immune cells require high amounts of glucose, amino acids and fatty acids to fulfill their energy demands. Thus, both compete over one pool of nutrients that falls short on needs, obliging cells to resort to alternative adaptive metabolic mechanisms that take part in shaping their inflammatory phenotypes. Aerobic or anaerobic glycolysis, oxidative phosphorylation, tryptophan catabolism, glutaminolysis, fatty acid synthesis or fatty acid oxidation, etc. are all mechanisms that contribute to immune modulation. Different pathways are triggered leading to genetic and epigenetic modulation with consequent reprogramming of immune cells such as T-cells (effector, memory or regulatory), tumor-associated macrophages (TAMs) (M1 or M2), natural killers (NK) cells (active or senescent), and dendritic cells (DC) (effector or tolerogenic), etc. Even host factors such as inflammatory conditions, obesity, caloric deficit, gender, infections, microbiota and smoking status, may be as well contributory to immune modulation, anti-tumor immunity and response to immune checkpoint inhibition. Given the complex and delicate metabolic networks within the tumor microenvironment controlling immune response, targeting key metabolic modulators may represent a valid therapeutic option to be combined with checkpoint inhibitors in an attempt to regain immune function.

Preventing Colitis-Associated Colon Cancer With Antioxidants: A Systematic Review

Inflammatory bowel disease (IBD) patients have an increased risk of developing colitis-associated colon cancer (CAC); however, the basis for inflammation-induced genetic damage requisite for neoplasia is unclear. Several studies have shown that IBD patients have signs of increased oxidative damage, which could be a result of genetic and environmental factors such as an excess in oxidant molecules released during chronic inflammation, mitochondrial dysfunction, a failure in antioxidant capacity, or oxidant promoting diets. It has been suggested that chronic oxidative environment in the intestine leads to the DNA lesions that precipitate colon carcinogenesis in IBD patients. Indeed, several preclinical and clinical studies show that different endogenous and exogenous antioxidant molecules are effective at reducing oxidation in the intestine. However, most clinical studies have focused on the short-term effects of antioxidants in IBD patients but not in CAC. This review article examines the role of oxidative DNA damage as a possible precipitating event in CAC in the context of chronic intestinal inflammation and the potential role of exogenous antioxidants to prevent these cancers.

Mechanisms and Applications of the Anti-cancer Effect of Pharmacological Ascorbic Acid in Cervical Cancer Cells

In recent years, L-ascorbic acid (L-AA), or vitamin C, has been attracting attention as a potential anticancer drug that mediates hydrogen peroxide-induced oxidation and ten-eleven translocation 2-catalyzed DNA demethylation. However, the precise mechanism by which L-AA acts remains unclear. We examined the cytotoxic effects of L-AA or sodium ascorbate in human cervical carcinoma cells by assessing cell viability, expression of cell cycle-related mRNAs and proteins, and mitochondrial functions, and by performing flow cytometric analyses of cell cycle profiles, apoptosis, cell proliferation, and production of reactive oxygen species (ROS). We later tested the effects of ascorbates in combination with two first-line chemotherapeutic drugs, cisplatin, and doxorubicin. At pharmacological concentrations (1–10 mM), L-AA increased ROS levels; decreased levels of several cell cycle-related proteins, including p53, p21, cyclin D1, and phosphorylated histone 3 at serine residue 10; induced DNA damage, as indicated by changes in γH2A.x; decreased levels of the anti-oxidative transcription factor Nrf2; and increased levels of catalase, superoxide dismutase 1, and endoplasmic reticulum stress-related indicators, such as the p-eIF2α/eIF2α ratio and CHOP levels. L-AA also promoted cell proliferation and induced apoptosis and mitochondrial dysfunction. Finally, L-AA increased the susceptibility of HeLa cells to cisplatin and doxorubicin. These findings provide insight into how the adjustment of the cellular ROS status through L-ascorbate (L-AA or sodium ascorbate) administration could potentially synergistically enhance the efficacy of cancer therapies.

Reactive oxygen species in cancer: a paradox between pro- and anti-tumour activities

Cancer constitutes a group of heterogeneous diseases that share common features. They involve the existence of altered cellular pathways which result in uncontrolled cell proliferation. Deregulation of production and/or elimination of reactive oxygen species (ROS) appear to be a relevant issue in most of them. ROS have a dual role in cell metabolism: they are compromised in normal cellular homeostasis, but their overproduction has been reported to promote oxidative stress (OS), a process that may induce the damage of cell structures. ROS accumulation is implicated in the activation of signaling pathways that promote cell proliferation and metabolic adaptations to tumour growth. One characteristic of cancer cells is the sensitivity to OS, which often results from the combination of high anabolic needs and hypoxic growth conditions. However, there is still no clear evidence about the levels of oxidant species that promote cellular transformation or, otherwise, if OS induction could be adequate as an antitumour therapeutic tool. There is a need for novel therapeutic strategies based on the new knowledge of cancer biology. Targeting oncogenic molecular mechanisms with non-classical agents and/or natural compounds would be beneficial as chemoprevention or new adjuvant therapies. In addition, epigenetics and environment, and particularly dietary factors may influence the development and prevention of cancer. This article will present a revision of the current research about molecular aspects proposed to be involved in the anticancer features of oxidant and antioxidant-based therapies targeting cancer cells, and their participation in the balance of oxidative species and cancer cell death.

Antioxidant Antagonises Chemotherapeutic Drug Effect in Lung Cancer Cell Line A549

Objective:

This study aimed to find whether antioxidants increase or decrease the effect of chemotherapeutic drug in the in vitro model.

Methods:

Small lung Cancer cell line (A549) was treated with anticancer drug 6-Thioguanine (6-TG) at different concentration viz., 1, 10, 50 and 100μM and the proliferation was measured using MTT assay. The antioxidant N-Acetyl Cysteine (NAC) in different ratios viz., 1mM, 5mM and 10mM were assayed for their effect in proliferation on the A549 cells alone and in combination with 6-TG.

Results:

Our experiment proves that anticancer drug 6-TG decreases the proliferation and the antioxidant NAC enhances the proliferation of A549 cells. Strikingly when co-treated with 6-TG, the antioxidant NAC diminished the proliferation reduction action of 6-TG on A549 cells.

Conclusion:

Our results suggest that antioxidants in fact benefit the tumor cell growth when treated alone and when in combination with anticancer drug, it severely impair the activity of the drug. We propose that extreme care should be taken when prescribing antioxidants alone or in combination with chemotherapeutics.

Vitamin C alleviates acute enterocolitis in Campylobacter jejuni infected mice

Human foodborne infections with the zoonotic pathogen Campylobacter jejuni are on the rise and constitute a significant socioeconomic burden worldwide. The health-beneficial, particularly anti-inflammatory effects of vitamin C (ascorbate) are well known. In our preclinical intervention study, we assessed potential anti-pathogenic and immunomodulatory effects of ascorbate in C. jejuni-infected secondary abiotic IL-10-/- mice developing acute campylobacteriosis similar to humans. Starting 4 days prior peroral C. jejuni-infection, mice received synthetic ascorbate via the drinking water until the end of the experiment. At day 6 post-infection, ascorbate-treated mice harbored slightly lower colonic pathogen loads and suffered from less severe C. jejuni-induced enterocolitis as compared to placebo control animals. Ascorbate treatment did not only alleviate macroscopic sequelae of infection, but also dampened apoptotic and inflammatory immune cell responses in the intestines that were accompanied by less pronounced pro-inflammatory cytokine secretion. Remarkably, the anti-inflammatory effects of ascorbate pretreatment in C. jejuni-infected mice were not restricted to the intestinal tract but could also be observed in extra-intestinal compartments including liver, kidneys and lungs. In conclusion, due to the potent anti-inflammatory effects observed in the clinical murine C. jejuni-infection model, ascorbate constitutes a promising novel option for prophylaxis and treatment of acute campylobacteriosis.

Biologically-Based Complementary and Alternative Medicine (CAM) Use in Cancer Patients: The Good, the Bad, the Misunderstood

As complementary and alternative medicine (CAM) becomes more popular, it is being used in cancer patients to aid in recovery or to treat symptoms associated with the current chemotherapy. Numerous papers exist that discuss patients using CAM with cancer chemotherapy and their outcomes-both positive and negative. However, in the case of the negative outcomes, the reason for the dangers or interactions with drugs are not made clear. Indeed, many chemotherapy regimens are rendered less effective by the well-meaning but uninformed patient or their family members and friends. Similarly, reports of positive outcomes with CAM and chemotherapy provide a strong basis for further research, but do not identify specific mechanisms of action. These small clinical studies and in vitro studies identify a necessary area for further research and provide a much needed, although often rejected, alternative look at whole treatment plans. Careful review of the available information and evaluation of the nature of the CAM effects are necessary to combat the misunderstanding and sometimes unwarranted claims over CAM use. This mini review will explore some of the commonly used CAM agents and their mechanisms of interactions with other treatments. Suggestions as to which agents can be safe and when to use them will be an integral part of this review.

Immunomodulatory and Antimicrobial Effects of Vitamin C

Humans have lost their vitamin C-synthesizing capacities during evolution. Therefore, the uptake of this essential compound from external sources is mandatory in order to prevent vitamin C-deficient conditions resulting in severe morbidities such as scurvy. The potent antioxidant, immunomodulatory, and antiinfectious effects of vitamin C are known since the 1930s. We here (i) review the impact of vitamin C on innate and adaptive immune functions, (ii) provide an overview of its antimicrobial, antibacterial, antiviral, antiparasitic, and antifungal properties, and finally, (iii) discuss vitamin C as an adjunct treatment option for the combat of human infections by bacteria, particularly by emerging multidrug-resistant species.

Inhibition of hsa_circ_0001313 (circCCDC66) induction enhances the radio-sensitivity of colon cancer cells via tumor suppressor miR-338-3p: Effects of cicr_0001313 on colon cancer radio-sensitivity

Circular RNA_0001313 (circ_0001313), also known as circCCDC66, is a novel circRNA that recently found to be upregulated in colon cancer tissues and promote colon cancer progression. However, the role of circ_0001313 in regulating radio-sensitivity of colon cancer and its molecular mechanism remain undetermined. Here we found circ_0001313 was significantly upregulated and miR-338-3p was downregulated in radio-resistant colon cancer tissues compared to radio-sensitive tissues. Radiation treatment in colon cells triggered a remarkable upregulation of circ_0001313 and a downregulation of miR-338-3p. Knockdown of circ_0001313 reduced cell viability, colony formation rate and increased caspase-3 activity in colon cancer cells under irradiation. Moreover, circ_0001313 act as a sponge for miR-338-3p in colon cancer cells. Furthermore, miR-338-3p could reverse the effects of circ_0001313 knockdown on cell viability, colony formation, and caspase-3 activity. These findings revealed that knockdown of circ_0001313 could induce radio-sensitivity of colon cancer cells by negatively regulating miR-338-3p.