Reactive oxygen species in colorectal cancer: The therapeutic impact and its potential roles in tumor progression via perturbation of cellular and physiological dysregulated pathways

Consumption of Feed Supplemented with Oat Beta-Glucan as a Chemopreventive Agent against Colon Cancerogenesis in Rats

Colorectal cancer (CRC) accounts for 30% of all cancer cases worldwide and is the second leading cause of cancer-related deaths. CRC develops over a long period of time, and in the early stages, pathological changes can be mitigated through nutritional interventions using bioactive plant compounds. Our study aims to determine the effect of highly purified oat beta-glucan on an animal CRC model. The study was performed on forty-five male Sprague-Dawley rats with azoxymethane-induced early-stage CRC, which consumed feed containing 1% or 3% low molar mass oat beta-glucan (OBG) for 8 weeks. In the large intestine, morphological changes, CRC signaling pathway genes (RT-PCR), and proteins (Western blot, immunohistochemistry) expression were analyzed. Whole blood hematology and blood redox status were also performed. Results indicated that the histologically confirmed CRC condition led to a downregulation of the WNT/β-catenin pathway, along with alterations in oncogenic and tumor suppressor gene expression. However, OBG significantly modulated these effects, with the 3% OBG showing a more pronounced impact. Furthermore, CRC rats exhibited elevated levels of oxidative stress and antioxidant enzyme activity in the blood, along with decreased white blood cell and lymphocyte counts. Consumption of OBG at any dose normalized these parameters. The minimal effect of OBG in the physiological intestine and the high activity in the pathological condition suggest that OBG is both safe and effective in early-stage CRC.

Selaginellin derivatives from Selaginella tamariscina and evaluation for anti-breast cancer activity

A phytochemical investigation of Selaginella tamariscina led to the isolation of 17 selaginellin derivatives. Their inhibitory activities against breast cancer cells were screened, and preliminary structure-activity relationships were also established. Among them, dimeric selaginellin 17 showed potential activity against MDA-MB-231 cells with an IC50 value of 3.2 ± 0.1 μM, corresponding to 4-fold higher potency than the reference compound 5-FU (IC50 14.8 ± 0.2 μM). Mechanistic studies indicated that 17 could cause G2/M phase arrest in MDA-MB-231 cells and induce apoptosis accompanied by increased ROS levels.

A reactive species reactions module for integration into genome-scale metabolic models for improved insights: Application to cancer

Reactive species (RS) play significant roles in many disease contexts. Despite their crucial roles in diseases including cancer, the RS are not adequately modeled in the genome-scale metabolic (GSM) models, which are used to understand cell metabolism in disease contexts. We have developed a scalable RS reactions module that can be integrated with any Recon 3D-derived human metabolic model, or after fine-tuning, with any metabolic model. With RS-integration, the GSM models of three cancers (basal-like triple negative breast cancer (TNBC), high grade serous ovarian carcinoma (HGSOC) and colorectal cancer (CRC)) built from Recon 3D, precisely highlighted the increases/decreases in fluxes (dysregulation) occurring in important pathways of these cancers. These dysregulations were not prominent in the standard cancer models without the RS module. Further, the results from these RS-integrated cancer GSM models suggest the following decreasing order in the ease of ferroptosis-targeting to treat the cancers: TNBC > HGSOC > CRC.

Isolinderalactone Induces Apoptosis, Autophagy, Cell Cycle Arrest and MAPK Activation through ROS-Mediated Signaling in Colorectal Cancer Cell Lines

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Isolinderalactone (ILL), a sesquiterpene isolated from the root extract of Lindera aggregata, has been reported to exhibit anti-proliferative and anti-metastatic activities in various cancer cell lines. However, the mechanisms associated with its antitumor effects on CRC cells remain unclear. ILL treatment significantly suppressed proliferation and induced cell cycle G2/M arrest in CRC cells by inhibiting the expression of cyclin B, p-cdc2, and p-cdc25c and up-regulating the expression of p21. In addition, ILL induced mitochondria-associated apoptosis through the up-regulation of cleaved -caspase-9 and -3 expression. ILL induced autophagy by increasing the levels of LC3B in CRC cells, which was partially rescued by treatment with an autophagy inhibitor (chloroquine). Furthermore, ILL increases the accumulation of reactive oxygen species (ROS) and activates the MAPK pathway. Application of the ROS scavenger, N-acetyl cysteine (NAC), effectively inhibited ILL toxicity and reversed ILL-induced apoptosis, cell cycle arrest, autophagy, and ERK activation. Taken together, these results suggest that ILL induces G2/M phase arrest, apoptosis, and autophagy and activates the MAPK pathway via ROS-mediated signaling in human CRC cells.

Water-Soluble Alkali Lignin as a Natural Radical Scavenger and Anticancer Alternative

Several phytochemicals, which display antioxidant activity and inhibit cancer cell phenotypes, could be used for cancer treatment and prevention. Lignin, as a part of plant biomass, is the second most abundant natural biopolymer worldwide, and represents approximately 30% of the total organic carbon content of the biosphere. Historically, lignin-based products have been viewed as waste materials of limited industrial usefulness, but modern technologies highlight the applicability of lignin in a variety of industrial branches, including biomedicine. The aims of our preliminary study were to compare the antioxidant properties of water-soluble alkali lignin solutions, before and after UV-B irradiation, as well as to clarify their effect on colon cancer cell viability (Colon 26), applied at low (tolerable) concentrations. The results showed a high antioxidant capacity of lignin solutions, compared to a water-soluble control antioxidant standard (Trolox) and remarkable radical scavenging activity was observed after their UV-B irradiation. Diminishment of cell viability as well as inhibition of the proliferative activity of the colon cancer cell line with an increase in alkali lignin concentrations were observed. Our results confirmed that, due to its biodegradable and biocompatible nature, lignin could be a potential agent for cancer therapy, especially in nanomedicine as a drug delivery system.

α7 Nicotinic acetylcholine receptor: a key receptor in the cholinergic anti-inflammatory pathway exerting an antidepressant effect

Depression is a common mental illness, which is related to monoamine neurotransmitters and the dysfunction of the cholinergic, immune, glutamatergic, and neuroendocrine systems. The hypothesis of monoamine neurotransmitters is one of the commonly recognized pathogenic mechanisms of depression; however, the drugs designed based on this hypothesis have not achieved good clinical results. A recent study demonstrated that depression and inflammation were strongly correlated, and the activation of alpha7 nicotinic acetylcholine receptor (α7 nAChR)-mediated cholinergic anti-inflammatory pathway (CAP) in the cholinergic system exhibited good therapeutic effects against depression. Therefore, anti-inflammation might be a potential direction for the treatment of depression. Moreover, it is also necessary to further reveal the key role of inflammation and α7 nAChR in the pathogenesis of depression. This review focused on the correlations between inflammation and depression as well-discussed the crucial role of α7 nAChR in the CAP.

Urinary volatile organic compounds for colorectal cancer screening, a systematic review and meta-analysis

BACKGROUND

The faecal immunochemical test (FIT) suffers from suboptimal performance and participation in colorectal cancer (CRC) screening. Urinary volatile organic compounds (VOCs) may be a useful alternative. We aimed to determine the diagnostic potential of urinary VOCs for CRC/adenomas. By relating VOCs to known pathways, we aimed to gain insight into the pathophysiology of colorectal neoplasia.

METHODS

A systematic search was performed in PubMed, EMBASE and Web of Science. Original studies on urinary VOCs for CRC/adenoma detection with a control group were included. QUADAS-2 tool was used for quality assessment. Meta-analysis was performed by adopting a bivariate model for sensitivity/specificity. Fagan's nomogram estimated the performance of combined FIT-VOC. Neoplasm-associated VOCs were linked to pathways using the KEGG database.

RESULTS

Sixteen studies-involving 837 CRC patients and 1618 controls-were included; 11 performed chemical identification and 7 chemical fingerprinting. In all studies, urinary VOCs discriminated CRC from controls. Pooled sensitivity and specificity for CRC based on chemical fingerprinting were 84% (95% CI 73-91%) and 70% (95% CI 63-77%), respectively. The most distinctive individual VOC was butanal (AUC 0.98). The estimated probability of having CRC following negative FIT was 0.38%, whereas 0.09% following negative FIT-VOC. Combined FIT-VOC would detect 33% more CRCs. In total 100 CRC-associated urinary VOCs were identified; particularly hydrocarbons, carboxylic acids, aldehydes/ketones and amino acids, and predominantly involved in TCA-cycle or alanine/aspartate/glutamine/glutamate/phenylalanine/tyrosine/tryptophan metabolism, which is supported by previous research on (colorectal)cancer biology. The potential of urinary VOCs to detect precancerous adenomas or gain insight into their pathophysiology appeared understudied.

CONCLUSION

Urinary VOCs hold potential for non-invasive CRC screening. Multicentre validation studies are needed, especially focusing on adenoma detection. Urinary VOCs elucidate underlying pathophysiologic processes.

Implication of gut microbes and its metabolites in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer with a significant impact on loss of life. In 2020, nearly 1.9 million new cases and over 9,35,000 deaths were reported. Numerous microbes that are abundant in the human gut benefit host physiology in many ways. Although the underlying mechanism is still unknown, their association appears to be crucial in the beginning and progression of CRC. Diet has a significant impact on the microbial composition and may increase the chance of getting CRC. Increasing evidence points to the gut microbiota as the primary initiator of colonic inflammation, which is connected to the development of colonic tumors. However, it is unclear how the microbiota contributes to the development of CRCs. Patients with CRC have been found to have dysbiosis of the gut microbiota, which can be identified by a decline in commensal bacterial species, such as those that produce butyrate, and a concurrent increase in harmful bacterial populations, such as opportunistic pathogens that produce pro-inflammatory cytokines. We believe that using probiotics or altering the gut microbiota will likely be effective tools in the fight against CRC treatment.

PURPOSE

In this review, we revisited the association between gut microbiota and colorectal cancer whether cause or effect. The various factors which influence gut microbiome in patients with CRC and possible mechanism in relation with development of CRC.

CONCLUSION

The clinical significance of the intestinal microbiota may aid in the prevention and management of CRC.

Flavonolignans and biflavonoids from Cephalotaxus oliveri exert neuroprotective effect via Nrf2/ARE pathway

Plants of the Cephalotaxus genus are rich in structurally diverse and naturally bioactive components, while limited studies have been reported for Cephalotaxus oliveri. Two undescribed flavonolignans and four undescribed biflavonoids, as well as thirteen known compounds, were isolated from the twigs and leaves of C. oliveri. Their structures were characterized by spectroscopic data analysis, and the absolute configurations were determined by electronic circular dichroism (ECD) calculations. All the isolated compounds were assayed for their neuroprotective activity against hydrogen peroxide (H2O2)-induced SH-SY5Y cell injury. All six undescribed compounds were effective to some degree, and umcephabiflovin B, apigenin 5-O-α-L-rhamnopyranosyl-(1 → 2)-6″-acetyl-β-D-glucopyranoside, and apigenin 7-O-β-D-glucoside exhibited good neuroprotective activity. Umcephabiflovin B protected SH-SY5Y cells against H2O2-induced neurotoxicity by repressing oxidative stress and apoptosis and by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-response element (ARE) pathway.

A new firewall in the fight against breast cancer: in-vitro and in-silico studies correlating chemistry to apoptotic activity of Otostegia fruticosa

Breast cancer is the most devastating disease for women. There is a great demand for new sources to treat this disease. Medicinal plants are an indispensable source of bioactive compounds with wide range of pharmacological activities. In-vitro cytotoxic activity of Otostegia fruticosa methanolic extract against human breast cancer was studied using MCF-7 cell line. The extract showed mildly potent activity (IC₅₀ = 51 ± 9.836 µg/mL) in comparison to the standard anticancer doxorubicin (IC₅₀ = 7.467 ± 1.05 µg/mL). Potential compounds responsible for activity have been identified using Molecular Operating Environment (MOE) module on the major compounds detected by HPLC-MS/MS technique against estrogen alpha receptor (ERα+: PDB ID 2JF9). 3,5-di-O-dicaffeoylquinic acid, hyperoside and rutin showed similar binding and antagonistic interaction with the estrogen alpha receptor as tamoxifen in several poses. The retrieved results confirm that we can add this plant to a powerful arsenal that combats this insidious disease.

AF8c, a Multi-Kinase Inhibitor Induces Apoptosis by Activating DR5/Nrf2 via ROS in Colorectal Cancer Cells

Simple Summary

AF8c, a lapatinib hybrid quinazoline-based EGFR/HER2 inhibitor, was chosen to scrutinize its antiproliferative activity in colorectal cancer (CRC) cells. We found that AF8cinduced apoptosis in CRC cells via diverse mechanisms. In addition to inhibiting the phosphorylation of the ErbB family, AF8c increased the mRNA and protein levels of death receptor 5 (DR5) in vitro and in vivo. In addition, AF8c upregulated several ER stress proteins and the redox-sensitive nuclear respiratory factor 2 alpha subunit (Nrf2) in a p53-dependent manner. We also found that the AF8c-induced increase in the levels of Nrf2, DR5, and apoptosis was diminished by p53 downregulation or knockdown. Furthermore, AF8c showed higher antiproliferative activity than lapatinib in the CRC mouse model in vivo. Therefore, our results suggest AF8c as a highly effective polypharmacological small molecule with an encouraging safety profile, both in vitro and in vivo, for further evaluation as a treatment of CRC.

Abstract

Our team has previously reported a series of quinazoline-based lapatinib hybrids as potent kinase-targeting anticancer agents. Among them, AF8c showed a relatively safe profile in colorectal cancer (CRC) cells. In this study, we delineate a novel anticancer activity of AF8c in CRC cells. AF8c mediated p53-dependent apoptosis of CRC cells via the generation of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS), as well as activation of nuclear respiratory factor 2 alpha subunit (Nrf2) and death receptor 5 (DR5), among others. The silencing of DR5 attenuated the expression levels of Nrf2 and partially inhibited AF8c-induced apoptosis. Additionally, upregulation of Nrf2 by AF8c evoked apoptosis through a decrease in antioxidant levels. Treatment of a CRC mice model with AF8c also resulted in the upregulation of DR5, Nrf2, and CHOP proteins, subsequently leading to a significant decrease in tumor burden. In comparison with lapatinib, AF8c showed higher cellular antiproliferative activity at the tested concentrations in CRC cells and synergized TRAIL effects in CRC cells. Overall, our results suggest that AF8c-induced apoptosis may be associated with DR5/Nrf2 activation through ER stress and ROS generation in CRC cells. These findings indicate that AF8c represents a promising polypharmacological molecule for the treatment of human CRC.

Structure-Activity Relationship of Pine Nut-Derived Peptides and Their Protective Effect on Nerve-Cell Mitochondria

This study aimed to investigate the structure-activity relationship of the pine nut antioxidant peptide WYPGK and its derivative peptides, and to evaluate the protective effect of the latter on oxidative damage to mitochondrial structure and function in PC12 cells. Molecular docking revealed the derivative peptides WYFGK and WYSGK to have higher affinity to the active region of sirtuin 3 (SIRT3) (−6.08 kcal/mol and −5.87 kcal/mol, respectively), hence indicating that they are promising SIRT3 inducers and antioxidant factors. The derivative peptide WYSGK presented the highest ORAC value (5457.70 µmol TE/g), ABTS scavenging activity (70.05%), and Fe2+-chelating activity (81.70%), followed by WYPGK and WYFGK. Circular dichroism and nuclear magnetic resonance data suggested that the presence of 3-Ser in WYSGK increased its β-sheet content, and that the active hydrogen atoms produced chemical shifts. In H2O2-induced PC12 cells, WYSGK substantially reduced ROS and MDA levels, and increased ATP levels. Transmission electron microscopy and Seahorse Analyze assay proved the peptide WYSGK to significantly alleviate mitochondrial damage and respiratory dysfunction (p < 0.05), thereby implying that a study of structure-activity relationships of the peptides can possibly be an effective approach for the development of functional factors.

Iron Oxide and Silicon Nanoparticles Modulate Mineral Nutrient Homeostasis and Metabolism in Cadmium-Stressed Phaseolus vulgaris

The application of nanoparticles (NPs) has been proved as an efficient and promising technique for mitigating a wide range of stressors in plants. The present study elucidates the synergistic effect of iron oxide nanoparticles (IONPs) and silicon nanoparticles (SiNPs) in the attenuation of Cd toxicity in Phaseolus vulgaris. Seeds of P. vulgaris were treated with IONPs (10 mg/L) and SiNPs (20 mg/L). Seedlings of uniform size were transplanted to pots for 40 days. The results demonstrated that nanoparticles (NPs) enhanced growth, net photosynthetic rate, and gas exchange attributes in P. vulgaris plants grown in Cd-contaminated soil. Synergistic application of IONPs and SiNPs raised not only K+ content, but also biosynthesis of polyamines (PAs), which alleviated Cd stress in P. vulgaris seedlings. Additionally, NPs decreased malondialdehyde (MDA) content and electrolyte leakage (EL) in P. vulgaris plants exposed to Cd stress. These findings suggest that stress alleviation was mainly attributed to the enhanced accumulation of K+ content, improved antioxidant defense system, and higher spermidine (Spd) and putrescine (Put) levels. It is suggested that various forms of NPs can be applied synergistically to minimize heavy metal stress, thus increasing crop production under stressed conditions.

Oxidative Distress Induces Wnt/β-Catenin Pathway Modulation in Colorectal Cancer Cells: Perspectives on APC Retained Functions

Colorectal cancer (CRC) is a multistep process that arises in the colic tissue microenvironment. Oxidative stress plays a role in mediating CRC cell survival and progression, as well as promoting resistance to therapies. CRC progression is associated with Wnt/β-Catenin signaling dysregulation and loss of proper APC functions. Cancer recurrence/relapse has been attributed to altered ROS levels, produced in a cancerous microenvironment. The effect of oxidative distress on Wnt/β-Catenin signaling in the light of APC functions is unclear. This study evaluated the effect of H₂O₂-induced short-term oxidative stress in HCT116, SW480 and SW620 cells with different phenotypes of APC and β-Catenin. The modulation and relationship of APC with characteristic molecules of Wnt/β-Catenin were assessed in gene and protein expression. Results indicated that CRC cells, even when deprived of growth factors, under acute oxidative distress conditions by H₂O₂ promote β-Catenin expression and modulate cytoplasmic APC protein. Furthermore, H₂O₂ induces differential gene expression depending on the cellular phenotype and leading to favor both Wnt/Catenin-dependent and -independent signaling. The exact mechanism by which oxidative distress can affect Wnt signaling functions will require further investigation to reveal new scenarios for the development of therapeutic approaches for CRC, in the light of the conserved functions of APC.

Oxidative Stress and Cellular Senescence: The Key Tumor-promoting Factors in Colon Cancer and Beneficial Effects of Polyphenols in Colon Cancer Prevention

Background:

Colon cancer is the third leading cause of cancer-related deaths worldwide. Colon tumorigenesis is a sequential process called “Adenoma-carcinoma sequence”. The alimentary habits, obesity, heavy alcohol consumption, inflammatory bowel diseases, family history of colon cancer, oxidative stress, and cellular senescence are the major risk factor influencing colon cancer development. Senescence contributes to the aging process as well as the development and progression of colon cancer. However, the precise mechanism underlying the aging-related progress of colon cancer is yet to be answered. Recent studies proposed that the senescent cell secretes Senescence-Associated Secretory Phenotype (SASP) includes pro-inflammatory cytokines, interleukins, growth factors, and proteases actively involved in the creation of pro-tumorigenic microenvironment.

Objective:

This review aims to provide an overview of ROS influence cellular senescence and colon cancer development as well as summarize the antioxidant and antiaging activity of natural flavonoids. Many of the studies had reported that pro-aging genes suppress cancer and various ‘markers’ are used to identify senescent cells in vitro and in vivo. The SASP of the cells may act as a link between senescence and cancer.

Conclusion:

This review facilitates a better understanding and might contribute to diagnostic and prognostic systems as well as to find out the novel and targeted therapeutic approaches. Additionally, we focused on the potential role of natural flavonoids in colon cancer therapies and highlighting the flavonoid-based treatments as innovative immunomodulatory strategies to inhibit the growth of colon cancer.

The Relationship Between Muscle Strength and Body Composition Measures and Cancer-Related Fatigue: A Systematic Review and Meta-Analysis

PROBLEM IDENTIFICATION

Cancer-related fatigue (CRF) substantially affects daily living and quality of life, but objective CRF measures remain limited. This review aimed to identify the correlation between muscle strength and body composition measures and CRF, as well as potential objective indicators for assessing CRF.

LITERATURE SEARCH

PubMed®, MEDLINE®, CINAHL®/PsycINFO®, and Embase® were searched for studies published from January 2000 to January 2021.

DATA EVALUATION

Study selection and quality assessment were conducted using the Critical Appraisals Skills Programme checklist and the Strengthening the Reporting of Observational Studies in Epidemiology statement. Comprehensive Meta-Analysis software was used to perform meta-analysis.

SYNTHESIS

25 studies were selected, and 19 measures were analyzed. CRF negatively correlated with hand grip strength, knee extensor strength, and the sit-to-stand test. No significant correlation was found between body composition measures and CRF.

IMPLICATIONS FOR NURSING

The evidence suggests that muscle strength measures may be potential indicators for CRF assessment. Combining objective and subjective CRF assessments could assist clinicians in evaluating the effectiveness of CRF interventions more accurately.

Evaluation of Enzyme Inhibitory Activity of Flavonoids by Polydopamine-Modified Hollow Fiber-Immobilized Xanthine Oxidase

In this study, a polydopamine (PDA)-modified hollow fiber-immobilized xanthine oxidase (XOD) was prepared for screening potential XOD inhibitors from flavonoids. Several parameters for the preparation of PDA-modified hollow fiber-immobilized XOD, including the dopamine concentration, modification time, XOD concentration and immobilization time, were optimized. The results show that the optimal conditions for immobilized XOD activity were a dopamine concentration of 2.0 mg/mL in 10.0 mM Tris-HCl buffer (pH 8.5), a modification time of 3.0 h, an XOD concentration of 1000 μg/mL in 10.0 mM phosphate buffer (pH 7.5) and an immobilization time of 3.0 h. Subsequently, the enzymatic reaction conditions such as the pH value and temperature were investigated, and the enzyme kinetics and inhibition parameters were determined. The results indicate that the optimal pH value (7.5) and temperature (37 °C) of the PDA-modified hollow fiber-immobilized XOD were consistent with the free enzyme. Moreover, the PDA-modified hollow fiber-immobilized XOD could still maintain above 50% of its initial immobilized enzyme activity after seven consecutive cycles. The Michaelis–Menten constant (K_m) and the half-maximal inhibitory concentration (IC₅₀) of allopurinol on the immobilized XOD were determined as 0.25 mM and 23.2 μM, respectively. Furthermore, the PDA-modified hollow fiber-immobilized XOD was successfully applied to evaluate the inhibitory activity of eight flavonoids. Quercetin, apigenin, puerarin and epigallocatechin showed a good inhibition effect, and their percentages of inhibition were (79.86 ± 3.50)%, (80.98 ± 0.64)%, (61.15 ± 6.26)% and (54.92 ± 0.41)%, respectively. Finally, molecular docking analysis further verified that these four active compounds could bind to the amino acid residues in the XOD active site. In summary, the PDA-modified hollow fiber-immobilized XOD is an efficient method for the primary screening of XOD inhibitors from natural products.

Klebsiella pneumoniae producing bacterial toxin colibactin as a risk of colorectal cancer development - A systematic review

Microbiota can significantly contribute to colorectal cancer initiation and development. It was described that E. coli harbouring polyketide synthase (pks) genes can synthetize bacterial toxin colibactin, which was first described by Nougayrede's group in 2006. E. coli positive for pks genes were overrepresented in colorectal cancer biopsies and, therefore, prevalence and the effect of pks positive bacteria as a risk factor in colorectal cancer development is in our interest. Interestingly, pks gene cluster in E. coli shares a striking 100% sequence identity with K. pneumoniae, suggesting that their function and regulation are conserved. Moreover, K. pneumoniae can express a variety of virulence factors, including capsules, siderophores, iron-scavenging systems, adhesins and endotoxins. It was reported that pks cluster and thereby colibactin is also related to the hypervirulence of K. pneumoniae. Acquisition of the pks locus is associated with K. pneumoniae gut colonisation and mucosal invasion. Colibactin also increases the likelihood of serious complications of bacterial infections, such as development of meningitis and potentially tumorigenesis. Even though K. pneumoniae is undoubtedly a gut colonizer, the role of pks positive K. pneumoniae in GIT has not yet been investigated. It seems that CRC-distinctive microbiota is already present in the early stages of cancer development and, therefore, microbiome analysis could help to discover the early stages of cancer, which are crucial for effectiveness of anticancer therapy. We hypothesize, that pks positive K. pneumoniae can be a potential biomarker of tumour prevalence and anticancer therapy response.

Signaling, metabolism, and cancer: An important relationship for therapeutic intervention

In cancerous cells, significant changes occur in the activity of signaling pathways affecting a wide range of cellular activities ranging from growth and proliferation to apoptosis, invasiveness, and metastasis. Extensive changes also happen with respect to the metabolism of a cancerous cell encompassing a wide range of functions that include: nutrient acquisition, biosynthesis of macromolecules, and energy generation. These changes are important and some therapeutic approaches for treating cancers have focused on targeting the metabolism of cancerous cells. Oncogenes and tumor suppressor genes have a significant effect on the metabolism of cells. There appears to be a close interaction between metabolism and the signaling pathways in a cancerous cell, in which the interaction provides the metabolic needs of a cancerous cell for uncontrolled proliferation, resistance to apoptosis, and metastasis. In this review, we have reviewed the latest findings in this regard and briefly review the most recent research findings regarding targeting the metabolism of cancer cells as a therapeutic approach for treatment of cancer.

Metabolic pathways in sporadic colorectal carcinogenesis: A new proposal

Given the reports made about geographical differences in Colorectal Cancer (CRC) occurrence, suggesting a link between dietary habits, genes and cancer risk, we hypothesise that there are four fundamental metabolic pathways involved in diet-genes interactions, directly implicated in colorectal carcinogenesis: folate metabolism; lipid metabolism; oxidative stress response; and inflammatory response. Supporting this hypothesis are the evidence given by the significant associations between several diet-genes polymorphisms and CRC, namely: MTHFR, MTR, MTRR and TS (involved in folate metabolism); NPY, APOA1, APOB, APOC3, APOE, CETP, LPL and PON1 (involved in lipid metabolism); MNSOD, SOD3, CAT, GSTP1, GSTT1 and GSTM1 (involved in oxidative stress response); and IL-1, IL-6, TNF-α, and TGF-β (involved in inflammatory response). We also highlight the association between some foods/nutrients/nutraceuticals that are important in CRC prevention or treatment and the four metabolic pathways proposed, and the recent results of genome-wide association studies, both assisting our hypothesis. Finally, we propose a new line of investigation with larger studies, using accurate dietary biomarkers and investigating the four metabolic pathways genes simultaneously. This line of investigation will be essential to understand the full complexity of the association between nature and nurture in CRC and perhaps in other types of cancers. Only with this in-depth knowledge will it be possible to make personalised nutrition recommendations for disease prevention and management.

Specifically Eliminating Tumor-Associated Macrophages with an Extra- and Intracellular Stepwise-Responsive Nanocarrier for Inhibiting Metastasis

Metastasis is the primary cause of death for most cancer patients, in which tumor-associated macrophages (TAMs) are involved through several mechanisms. While hitherto there is still a lack of study on exclusive elimination of TAMs to inhibit metastasis due to the difficulties in specific targeting of TAMs, we construct an extra- and intracellular stepwise-responsive delivery system p-(aminomethyl)benzoic acid (PAMB)/doxorubicin (DOX) to achieve specific TAM depletion for the first time, thereby preventing tumor metastasis. Once accumulated into the tumor, PAMB/DOX would stepwise responsively (hypoxia and reactive oxygen species (ROS) responsively) disintegrate to expose the TAM-targeting ligand and release DOX sequentially, which depletes TAMs effectively in vivo. Owing to the inhibition of extracellular matrix (ECM) degradation, neovascularization, and tumor invasion contributed by TAM depletion, lung metastasis was successfully inhibited. Furthermore, PAMB/DOX showed efficient inhibition against tumor growth as well as spontaneous metastasis formation when combined with additional chemotherapy, representing a safe and efficient nanoplatform to modulate the adverse tumor microenvironment via TAM elimination.

Tangeretin: a mechanistic review of its pharmacological and therapeutic effects

To date, a large number of synthetic drugs have been developed for the treatment and prevention of different disorders, such as neurodegenerative diseases, diabetes mellitus, and cancer. However, these drugs suffer from a variety of drawbacks including side effects and low efficacy. In response to this problem, researchers have focused on the plant-derived natural products due to their valuable biological activities and low side effects. Flavonoids consist of a wide range of naturally occurring compounds exclusively found in fruits and vegetables and demonstrate a number of pharmacological and therapeutic effects. Tangeretin (TGN) is a key member of flavonoids that is extensively found in citrus peels. It has different favorable biological activities such as antioxidant, anti-inflammatory, antitumor, hepatoprotective, and neuroprotective effects. In the present review, we discuss the various pharmacological and therapeutic effects of TGN and then, demonstrate how this naturally occurring compound affects signaling pathways to exert its impacts.

Studies on the structure-activity relationship and interaction mechanism of flavonoids and xanthine oxidase through enzyme kinetics, spectroscopy methods and molecular simulations

In this study, some flavonoids were screened as potent xanthine oxidase (XO) inhibitors in vitro. Flavonoid 9 was demonstrated to exhibit the inhibitory activity through a ping-pong mechanism. Further structure-activity relationship revealed that different structural elements had greatly influenced the inhibition effect on XO and underlined the requirement of hydroxyl groups at C5 and C4' of flavonoid type I. Moreover, some bioactive flavonoids could efficiently quench the intrinsic fluorescence of XO by either static or static-dynamic mixed mechanism. The synchronous fluorescence, ANS-binding fluorescence, Fourier transform infrared spectra and circular dichroism suggested that active flavonoids could bind to the active center of XO, prevent the entrance of substrate, and induce the rearrangement and conformation change of its secondary structures, ultimately resulting in the significant inhibition effect. Additionally, molecular docking further confirmed these conclusions and highlighted the great importance of hydrophobic interactions and hydrogen bonds for the formation of stable complex conformation.

Function and mechanisms of microRNA-20a in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-associated mortality worldwide. CRC currently has no specific biomarkers to promote its diagnosis and treatment and the underlying mechanisms regulating its pathogenesis have not yet been determined. MicroRNAs (miRs) are small, non-coding RNAs that exhibit regulatory functions and have been demonstrated to serve a crucial role in the post-transcriptional regulatory processes of gene expression that is associated with cell physiology and disease progression. Recently, abnormal miR-20a expression has been identified in a number of cancers types and this has become a novel focus within cancer research. High levels of miR-20a expression have been identified in CRC tissues, serum and plasma. In a recent study, miR-20a was indicated to be present in feces and to exhibit a high sensitivity to CRC. Therefore, miR-20a may be used as a marker for CRC and an indicator that can prevent the invasive examination of patients with this disease. Changes in the expression of miR-20a during chemotherapy can be used as a biomarker for monitoring resistance to treatment. In conclusion, miR-20a exhibits the potential for clinical application as a novel diagnostic biomarker and therapeutic target for use in patients with CRC. The present study focused on the role and mechanisms of miR-20a in CRC.

Hyperoside Induces Breast Cancer Cells Apoptosis via ROS-Mediated NF-κB Signaling Pathway

Hyperoside (quercetin 3-o-β-d-galactopyranoside) is one of the flavonoid glycosides with anti-inflammatory, antidepressant, and anti-cancer effects. But it remains unknown whether it had effects on breast cancer. Here, different concentrations of hyperoside were used to explore its therapeutic potential in both breast cancer cells and subcutaneous homotransplant mouse model. CCK-8 and wound healing assays showed that the viability and migration capability of Michigan Cancer Foundation-7 (MCF-7) and 4T1 cells were inhibited by hyperoside, while the apoptosis of cells were increased. Real-time quantitative PCR (qRT-PCR) and western blot analysis were used to detect mRNA and the protein level, respectively, which showed decreased levels of B cell lymphoma-2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP), and increased levels of Bax and cleaved caspase-3. After exploration of the potential mechanism, we found that reactive oxygen species (ROS) production was reduced by the administration of hyperoside, which subsequently inhibited the activation of NF-κB signaling pathway. Tumor volume was significantly decreased in subcutaneous homotransplant mouse model in hyperoside-treated group, which was consistent with our study in vitro. These results indicated that hyperoside acted as an anticancer drug through ROS-related apoptosis and its mechanism included activation of the Bax-caspase-3 axis and the inhibition of the NF-κB signaling pathway.

Mitochondrion: I am more than a fuel server

Apart from reliable management of the "powerhouse" of the cell, mitochondria faithfully orchestrate a diverse array of important and critical functions in governing cellular signaling, apoptosis, autophagy, mitophagy and innate and adaptive immune system. Introduction of instability and imbalance in the mitochondrial own genome or the nuclear encoded mitochondrial proteome would result in the manifestation of various diseases through alterations in the oxidative phosphorylation system (OXPHOS) and nuclear-mitochondria retrograde signaling. Understanding mitochondrial biology and dynamism are thus of paramount importance to develop strategies to prevent or treat various diseases caused due to mitochondrial alterations.

MicroRNAs as potential therapeutic targets to predict responses to oxaliplatin in colorectal cancer: From basic evidence to therapeutic implication

Colorectal cancer (CRC) is one of the most common malignancies with poor prognosis. Oxaliplatin-based chemotherapy is an important treatment for CRC; however, the cells develop resistance to therapy. The mechanisms underlying oxaliplatin resistance are complex and unclear. There is increasing evidence that microRNAs (miRNAs) (i.e., miR-34a, miR-143, miR-153, miR-27a, miR-218, and miR-520) play an essential role in tumorigenesis and chemotherapy resistance, by targeting various cellular and molecular pathways (i.e., PI3K/Akt/Wnt, EMT, p53, p21, and ATM) that are involved in the pathogenesis of CRC. Identifying the miRNAs that are involved in chemo-resistance, and their function, may help as a potential therapeutic option for treatment of CRC or as potential prognostic biomarker. Here, we summarized the clinical impact of miRNAs that have critical roles in the development of resistance to oxaliplatin in CRC.

Pro-apoptotic effect of haem oxygenase-1 in human colorectal carcinoma cells via endoplasmic reticular stress

Several biological effects of haem oxygenase (HO)‐1, including anti‐inflammatory, antiapoptotic and antioxidative properties were reported; however, the role of HO‐1 in apoptosis is still unclear. In the presence of stimulation by cobalt protoporphyrin (CoPP), an HO‐1 inducer, apoptotic characteristics were observed, including DNA laddering, hypodiploid cells, and cleavages of caspase (Casp)‐3 and poly(ADP) ribose polymerase (PARP) proteins in human colon carcinoma COLO205, HCT‐15, LOVO and HT‐29 cells in serum‐free (SF) conditions with increased HO‐1, but not heat shock protein 70 (HSP70) or HSP90. The addition of 10% foetal bovine serum (FBS) or 1% bovine serum albumin accordingly inhibited CoPP‐induced apoptosis and HO‐1 protein expression in human colon cancer cells. CoPP‐induced apoptosis of colon cancer cells was prevented by the addition of the pan‐caspase inhibitor, Z‐VAD‐FMK (VAD), and the Casp‐3 inhibitor, Z‐DEVD‐FMK (DEVD). N‐Acetyl cysteine inhibited reactive oxygen species‐generated H₂O₂‐induced cell death with reduced intracellular peroxide production, but did not affect CoPP‐induced apoptosis in human colorectal carcinoma (CRC) cells. Two CoPP analogs, ferric protoporphyrin and tin protoporphyrin, did not affect the viability of human CRC cells or HO‐1 expression by those cells, and knockdown of HO‐1 protein expression by HO‐1 small interfering (si)RNA reversed the cytotoxic effect elicited by CoPP. Furthermore, the carbon monoxide (CO) donor, CORM, but not FeSO₄ or biliverdin, induced DNA ladders, and cleavage of Casp‐3 and PARP proteins in human CRC cells. Increased phosphorylated levels of the endoplasmic reticular (ER) stress proteins, protein kinase R‐like ER kinase (PERK), and eukaryotic initiation factor 2α (eIF2α) by CORM and CoPP were identified, and the addition of the PERK inhibitor, GSK2606414, inhibited CORM‐ and CoPP‐induced apoptosis. Increased GRP78 level and formation of the HO‐1/GRP78 complex were detected in CORM‐ and CoPP‐treated human CRC cells. A pro‐apoptotic role of HO‐1 against the viability of human CRC cells via induction of CO and ER stress was firstly demonstrated herein.