Effects of probiotic supplementation on chronic inflammatory process modulation in colorectal carcinogenesis.

The current study investigated the potential effects of probiotic supplementation on colorectal carcinogenesis chemically induced with 1,2-dimethylhydrazine (DMH) and treated with 5-fluorouracil (5FU)-based chemotherapy in mice. Animals were randomly allocated in five different groups: Control: which not receive any treatment throughout the experimental course; Colitis model group (DMH): treated with DMH; DMH+ 5FU: animals received I.P. (intraperitoneal) dose of chemotherapy on a weekly basis; DMH+PROB: animals received daily administrations (via gavage) of probiotics (Lactobacillus: acidophilus and paracasei, Bifidobacterium lactis and bifidum); and DMH+ PROB+ 5FU: animals received the same treatment as the previous groups. After ten-week treatment, mice's large intestine was collected and subjected to colon length, histopathological, periodic acid-schiff (PAS) staining and immunohistochemistry (TLR2, MyD88, NF-κB, IL-6, TLR4, TRIF, IRF-3, IFN-γ, Ki-67, KRAS, p53, IL-10, and TGF-ß) analyzes. Variance (ANOVA) and Kruskal-Wallis tests were used for statistical analysis, at significance level p 0.05. Probiotics' supplementation has increased the production of Ki-67 cell-proliferation marker, reduced body weight, and colon shortening, as well as modulated the chronic inflammatory process in colorectal carcinogenesis by inhibiting NF-κB expression and mitigating mucin depletion. Thus, these findings lay a basis for guide future studies focused on probiotics' action mechanisms in tumor microenvironment which might have implications in clinical practice.

Lactobacillus acidophilus suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma through producing valeric acid.

BACKGROUND: Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC. METHODS: NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L. acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids. FINDINGS: L. acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L. acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L. acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC. INTERPRETATION: L. acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC. FUNDING: Shown in Acknowledgments.

Ursolic acid-loaded chitosan nanoparticles suppress 7,12-dimethylbenz(a)anthracene-induced oral tumor formation through their antilipid peroxidative potential in golden Syrian hamsters.

Oral cancer, a disfiguring and life threatening cancer, significantly affects the day-to-day life of not only the patients but also their family members in terms of life quality and financial burden. India records higher incidence of oral cancer every year and is mainly due to the habituation of tobacco products and alcohol abuse. Delay in diagnosis and treatment influences India's higher incidence of oral cancer, where annually 50,000-60,000 oral carcinoma cases are reported. 7,12-dimethylbenz(a)anthracene (DMBA)-induced cancer in the oral cavity mimics human oral cancer in histopathological, molecular, and morphological aspects, and thus, by using this paradigm, the tumor inhibiting efficacy of medicinal plants or herbs and their components is scientifically validated. Ursolic acid, due to its multiple pharmacological effects, has been attracted, in recent years, for chemoprevention research program. Though, ursolic acid has been shown to have beneficial effects, its poor water solubility and bioavailability hinder to exert its 100% efficacy. Therefore, ursolic acid is encapsulated in either natural or synthetic polymers to enhance its therapeutic efficacy. Chitosan is one of the natural polymers that have been employed in the synthesis of nanoparticles to improve the drug efficacy. The present study has thus chosen ursolic acid-loaded chitosan nanoparticles (UACNP) to assess its anticancer efficacy in the DMBA-induced oral carcinoma. The anticancer efficacy of UACNP in experimental oral carcinogenesis was assessed by employing the status of oxidative markers and detoxification cascade as an end point. DMBA-induced abnormalities in the status of oxidative markers and detoxification cascade were reversed by ursolic acid-loaded chitosan nanoparticles. The tumor inhibiting or suppressing effect of UACNP is thus explored in experimental oral carcinogenesis.

Combination of vitamin D and probiotics inhibits chemically induced colorectal carcinogenesis in Wistar rats.

The modulation of inflammatory elements, cell differentiation and proliferation by vitamin D and the role of probiotics in the intestinal microbiota and immunogenic response have sparked interest in the application of both in chemotherapeutics and chemoprevention of colorectal tumors. AIMS: The present study aimed to investigate the effects of isolated and/or combined treatment of vitamin D3 and probiotics on colorectal carcinogenesis. MAIN METHODS: Pre-neoplastic lesions were induced with 1,2-dimethylhydrazine in the colon of Wistar rats, which were treated with probiotics and/or vitamin D in three different approaches (simultaneous, pre-, and post-treatment). We investigated the frequency of aberrant crypt foci (ACF) and aberrant crypt (AC) in the distal colon, fecal microbiome composition, gene and protein expression through immunohistochemical and RT-PCR assays, and general toxicity through water consumption and weight gain monitoring. KEY FINDINGS: Results confirm the systemic safety of treatments, and show a protective effect of vitamin D and probiotics in all approaches studied, as well as in combined treatments, with predominance of different bacterial phyla compared to controls. Treated groups show different levels of Nrf2, GST, COX2, iNOS, ß-catenin and PCNA expression. SIGNIFICANCE: These experimental conditions explore the combination of vitamin D and probiotics supplementation at low doses over pathways involved in distinct stages of colorectal carcinogenesis, with results supporting its application in prevention and long-term strategies.

Mesenchymal Stem Cells and Selenium Nanoparticles Synergize with Low Dose of Gamma Radiation to Suppress Mammary Gland Carcinogenesis via Regulation of Tumor Microenvironment.

Breast cancer is one of the most prevalent and deadliest cancers among women in the world because of its aggressive behavior and inadequate response to conventional therapies. Mesenchymal stem cells (MSCs) combined with green nanomaterials could be an efficient tool in cell cancer therapy. This study examined the curative effects of bone marrow-derived mesenchymal stem cells (BM-MSCs) with selenium nanoparticles (SeNPs) coated with fermented soymilk and a low dose of gamma radiation (LDR) in DMBA-induced mammary gland carcinoma in female rats. DMBA-induced mammary gland carcinoma as marked by an elevation of mRNA level of cancer promoter genes (Serpin and MIF, LOX-1, and COL1A1) and serum level of VEGF, TNF-α, TGF-ß, CA15-3, and caspase-3 with the reduction in mRNA level of suppressor gene (FST and ADRP). These deleterious effects were hampered after treatment with BM-MSCs (1 × 106 cells/rat) once and daily administration of SeNPs (20 mg/kg body weight) and exposure once to (0.25 Gy) LDR. Finally, MSCs, SeNPs, and LDR notably modulated the expression of multiple tumor promoters and suppressor genes playing a role in breast cancer induction and suppression.

Oncohistones: a roadmap to stalled development.

Since the discovery of recurrent mutations in histone H3 variants in paediatric brain tumours, so-called 'oncohistones' have been identified in various cancers. While their mechanism of action remains under active investigation, several studies have shed light on how they promote genome-wide epigenetic perturbations. These findings converge on altered post-translational modifications on two key lysine (K) residues of the H3 tail, K27 and K36, which regulate several cellular processes, including those linked to cell differentiation during development. We will review how these oncohistones affect the methylation of cognate residues, but also disrupt the distribution of opposing chromatin marks, creating genome-wide epigenetic changes which participate in the oncogenic process. Ultimately, tumorigenesis is promoted through the maintenance of a progenitor state at the expense of differentiation in defined cellular and developmental contexts. As these epigenetic disruptions are reversible, improved understanding of oncohistone pathogenicity can result in needed alternative therapies.

Improved antimutagenic effect of Pyrostegia venusta (Ker Gawl. ) Miers nanostructured extract in liposome and polymeric nanoparticle

Abstract Pyrostegia venusta (Ker Gawl.) Miers, popularly known as "Cipó-de São-João", has been used in traditional medicine for its therapeutic properties. Nanotechnology is able to enhance the pharmacological activity of plant extracts. In this context, liposomes and polymeric nanoparticles containing P. venusta ethanolic extract were developed and then physico-chemically characterized to evaluate the mutagenic/antimutagenic effects of P. venusta. In addition, transaminases and serum creatinine were biochemically analyzed for liver and renal damage, respectively. The micronucleus test was performed with male Swiss mice treated orally for 15 consecutive days with free extracts and nanostructured with P. venusta, and then intraperitoneally with N-ethyl-N-nitrosurea (50 mg/kg) on the 15th day of treatment. Micronucleated polychromatic erythrocytes (MNPCE) were evaluated in bone marrow. There was a significant reduction in the frequency of MNPCE (LPEPV = 183% and NPEPV = 114%, p < 0.001), indicating antimutagenic potential of the nanostructured extracts with P. venusta. The groups treated with only nanostructured extract did not show an increase in MNPCE frequency, and biochemical analyzes showed no significant difference between treatments. The liposomes and polymeric nanoparticles containing Pyrostegia venusta ethanolic extract showed biological potential in preventing the first step of carcinogenesis under the experimental conditions

Protective role of a melon superoxide dismutase combined with gliadin (GliSODin) on the status of lipid peroxidation and antioxidant defense against azoxymethane-induced experimental colon carcinogenesis.

BACKGROUND: Azoxymethane (AOM) is a potent carcinogenic agent commonly used to induce colon cancer in rats and mice, with the cytotoxicity of AOM mediated by oxidative stress. AIM OF STUDY: This study investigated the protective effect of a natural antioxidant (GliSODin) against AOM-induced oxidative stress and carcinogenesis in rat colon. METHODS: Twenty male Wistar rats were randomly divided into four groups (five rats/group). The control group was fed a basal diet. AOM-treated group (AOM) was fed a basal diet and received intraperitoneal injections of AOM for 2 weeks at a dose of 15 mg/kg. The GliSODin treatment group (superoxide dismutase [SOD]) received oral supplementation of GliSODin (300 mg/kg) for 3 months, and the fourth combined group received AOM and GliSODin (AOM + SOD). All animals were continuously fed ad libitum until the age of 16 weeks when all rats were sacrificed. The colon tissues were examined microscopically for pathological changes and aberrant crypt foci (ACF) development, oxidant status (lipid peroxidation-LPO), and enzyme antioxidant system (glutathione [GSH], GSH-S-transferase, catalase, and SOD). RESULTS: Our results showed that AOM induced ACF development and oxidative stress (GSH depletion and lipid peroxidation) in rat colonic cells. The concomitant treatment of AOM with GliSODin significantly ameliorated the cytotoxic effects of AOM. CONCLUSION: The results of this study provide in vivo evidence that GliSODin reduced the AOM-induced colon cancer in rats, through their potent antioxidant activities.

YY1-induced long non-coding RNA PSMA3 antisense RNA 1 functions as a competing endogenous RNA for microRNA 214-5p to expedite the viability and restrict the apoptosis of bladder cancer cells via regulating programmed cell death-ligand 1.

Bladder cancer (BC) is one of the most common malignant tumors in the urinary system. Our research aimed to explore the function and underlying mechanisms of long noncoding RNA (lncRNA) PSMA3-AS1 in BC. RT-qPCR was utilized to detect the levels of PSMA3-AS1, miR-214-5p, and PD-L1. ChIP assay was employed to confirm the transcription factor of PSMA3-AS1. Luciferase reporter assay was carried out to demonstrate the relationships between miR-214-5p and PSMA3-AS1 or PD-L1. The diagnostic value of PSMA3-AS1 was evaluated by the ROC curve. CCK-8, wound healing, transwell, and flow cytometry assays were applied to analyze cell viability, migration, invasion, and apoptosis. Western blotting was used to confirm the expression of cleaved caspase-3. The present study revealed that BC tissues and cells exhibited an increased expression in PSMA3-AS1. High expression of PSMA3-AS1 was related to poor prognosis in BC patients. Then, the area under the ROC curve for PSMA3-AS1 was up to 0.8954. Moreover, ChIP assay elaborated that YY1 could bind to the PSMA3-AS1 promoter region. Furthermore, it was found that that PSMA3-AS1 knockdown repressed BC cell viability and metastasis, and promoted apoptosis. In addition, miR-214-5p was inversely correlated with PSMA3-AS1 or PD-L1 levels. MiR-214-5p deletion reversed the impacts of PSMA3-AS1 deletion on BC progression, and PD-L1 inhibition also abrogated the influence of miR-214-5p deletion in BC development. In conclusion, YY1-induced PSMA3-AS1 exerted an oncogenic function in BC cells via targeting miR-214-5p and enhancing PD-L1, providing potential biomarkers for BC therapy.

Dietary Barley Leaf Mitigates Tumorigenesis in Experimental Colitis-Associated Colorectal Cancer.

Dietary barley (Hordeum vulgare L.) leaf (BL) is a popular functional food known to have potential health benefits; however, the effect of BL in colorectal cancer prevention has not been examined. Here, we examined the role of BL on the prevention of colorectal carcinogenesis and defined the mechanism involved. BL supplementation could protect against weight loss, mitigate tumor formation, and diminish histologic damage in mice treated with azoxymethane (AOM) and dextran sulfate sodium (DSS). Moreover, BL suppressed colonic expression of inflammatory enzymes, while improving the mucosal barrier dysfunctions. The elevated levels of cell proliferation markers and the increased expression of genes involved in ß-catenin signaling were also reduced by BL. In addition, analyses of microbiota revealed that BL prevented AOM/DSS-induced gut microbiota dysbiosis by promoting the enrichment of Bifidobacterium. Overall, these data suggest that BL is a promising dietary agent for preventing colitis-associated colorectal cancer.

Honokiol Affects Stem Cell Viability by Suppressing Oncogenic YAP1 Function to Inhibit Colon Tumorigenesis.

Honokiol (HNK) is a biphenolic compound that has been used in traditional medicine for treating various ailments, including cancers. In this study, we determined the effect of HNK on colon cancer cells in culture and in a colitis-associated cancer model. HNK treatment inhibited proliferation and colony formation while inducing apoptosis. In addition, HNK suppressed colonosphere formation. Molecular docking suggests that HNK interacts with reserve stem cell marker protein DCLK1, with a binding energy of -7.0 Kcal/mol. In vitro kinase assays demonstrated that HNK suppressed the DCLK1 kinase activity. HNK also suppressed the expression of additional cancer stem cell marker proteins LGR5 and CD44. The Hippo signaling pathway is active in intestinal stem cells. In the canonical pathway, YAP1 is phosphorylated at Ser127 by upstream Mst1/2 and Lats1/2. This results in the sequestration of YAP1 in the cytoplasm, thereby not allowing YAP1 to translocate to the nucleus and interact with TEAD1-4 transcription factors to induce gene expression. However, HNK suppressed Ser127 phosphorylation in YAP1, but the protein remains sequestered in the cytoplasm. We further determined that this occurs by YAP1 interacting with PUMA. To determine if this also occurs in vivo, we performed studies in an AOM/DSS induced colitis-associated cancer model. HNK administered by oral gavage at a dose of 5mg/kg bw for 24 weeks demonstrated a significant reduction in the expression of YAP1 and TEAD1 and in the stem marker proteins. Together, these data suggest that HNK prevents colon tumorigenesis in part by inducing PUMA-YAP1 interaction and cytoplasmic sequestration, thereby suppressing the oncogenic YAP1 activity.

The chemoprotective effects of IFN-α-2b on rat hepatocarcinogenesis are blocked by vitamin E supplementation.

Many cancer patients receive their classical therapies together with vitamin supplements. However, the effectiveness of these strategies is on debate. Here we aimed to evaluate how vitamin E supplementation affects the anticancer effects of interferon (IFN-α) using an early-model of liver cancer development (initiation-promotion, IP). Male Wistar rats subjected to this model were divided as follows: untreated (IP), IP treated with recombinant IFN-α-2b (6.5  ×  105 U/kg), IP treated with vitamin E (50 mg/kg), and IP treated with combination of vitamin E and IFN-α-2b. After treatments rats were fasted and euthanized and plasma and livers were collected. Combined administration of vitamin E and IFN-α-2b induced body weight drop, increased liver apoptosis, and low levels of hepatic lipids. Interestingly, vitamin E and IFN-α-2b combination also induced an increase in altered hepatic foci number, but not in size. It seems that vitamin E acts on its antioxidant capability in order to block the oxidative stress induced by IFN-α-2b, blocking in turn its beneficial effects on preneoplastic livers, leading to harmful final effects. In conclusion, this study shows that vitamin E supplementation in IFN-α-2b-treated rats exerts unwanted effects; and highlights that in spite of being natural, nutritional supplements may not always exert beneficial outcomes when used as complementary therapy for the treatment of cancer.

Imunoexpressão da Yes-Associated Protein (YAP) em hiperceratoses e displasias epiteliais orais / Immunoexpression of Yes-Associated Protein (YAP) in hyperkeratosis and oral epithelial dysplasia

A busca por um biomarcador que auxilie na predição de risco de transformação maligna das desordens orais potencialmente malignas (DOPMs) representa um grande desafio, já que pode auxiliar no manejo precoce e adequado dos pacientes. Este estudo avaliou a imunoexpressão da Yes-Associated Protein (YAP) em lesões intraorais leucoplásicas, eritroplásicas ou leucoeritroplásicas, com diagnóstico histopatológico de hiperceratose ou displasia epitelial oral (DEO), correlacionando essa imunoexpressão com o grau de severidade morfológica dessas lesões. A amostra foi composta por 20 casos de hiperceratoses e 53 casos de DEOs, além de 10 casos de mucosa oral normal (grupo controle). Para a avaliação do grau de displasia, foram utilizadas as gradações da OMS (EL-NAGGAR et al., 2017) e o Sistema Binário (KUJAN et al., 2006), sendo o perfil imunoistoquímico da proteína YAP avaliado por meio de escores, que variaram entre 0 e 3, com base em sua localização intracelular (citoplasmática ou nuclear) e por sua distribuição no tecido epitelial. Para a análise entre os parâmetros estudados foram realizados os testes estatísticos Qui-quadrado de Pearson, Exato de Fisher, além de testes não paramétricos, (nível de significância de 95%). Displasias leves foram enquadradas (100%) no baixo risco de transformação maligna, enquanto as moderadas dividiram-se entre baixo (47%) e alto risco (53%), sendo as displasias severas, em sua maior parte (71%), classificadas como de alto risco (p < 0,001). O grupo controle exibiu imunomarcação de escore 0 (80%), as hiperceratoses e displasias leves (em 80% das vezes) exibiram escore 1, já nas displasias moderadas (63%) e severas (79%), foram predominantes os escores 2 e 3; com padrão de imunomarcação nuclear associado ao alto risco de transformação maligna sugerido pelo Sistema binário (p = 0,002). A imunoexpressão da YAP foi semelhante entre hiperceratoses e displasias leves, o que deve suscitar maior atenção dos profissionais frente aos casos de hiperceratose, além disto a expressão da YAP aparenta dicotomizar as DOPMs entre as lesões com baixo risco de transformação maligna e as lesões com alto risco, o que pode sugerir no futuro, sua utilização como potencial marcador preditivo de progressão destas lesões (AU).

The search for a biomarker that helps to predict the risk of malignant transformation of oral potentially malignant disorders (OPMDs) represents a great challenge, as it can help in the early and adequate management of patients. This study evaluated the immunoexpression of Yes-Associated Protein (YAP) in intraoral leukoplastic, erythroplastic or leukoerythroplastic lesions, with histopathological diagnosis of hyperkeratosis or oral epithelial dysplasia (OED), correlating this immunoexpression with the degree of morphological severity of these lesions. The sample consisted of 20 cases of hyperkeratosis and 53 cases of OED, in addition to 10 cases of normal oral mucosa (control group). To assess the degree of dysplasia, the WHO grading (EL-NAGGAR et al., 2017) and the Binary System (KUJAN et al., 2006) were used, and the immunohistochemical profile of the YAP protein was evaluated through scores, which ranged from 0 to 3, based on their intracellular location (cytoplasmic or nuclear) and their distribution in the epithelial tissue. For the analysis of the studied parameters, Pearson's Chi-square and Fisher's Exact statistical tests were performed, in addition to non-parametric tests (significance level of 95%). Mild dysplasias were classified (100%) in the low risk of malignant transformation, while the moderate ones were divided between low (47%) and high risk (53%), with severe dysplasias, for the most part (71%), classified as high risk (p < 0.001). The control group exhibited score 0 of immunostaining (80%), hyperkeratosis and mild dysplasias (80% of booth) exhibit score 1, whereas in moderate (63%) and severe dysplasia (79%), the predominant scores was 2 and 3; with a pattern of nuclear immunostaining associated with the high risk of malignant transformation suggested by the Binary System (p = 0.002). The immunoexpression of YAP was similar between hyperkeratosis and mild dysplasias, which should attract greater attention from professionals in cases of hyperkeratosis. Furthermore, the expression of YAP appears to dichotomize OPMDs between lesions with low risk of malignant transformation and lesions with high risk, which may suggest, in the future, its use as a potential predictive marker of the progression for these lesions (AU).

GDI2 is a target of paclitaxel that affects tumorigenesis of prostate cancer via the p75NTR signaling pathway.

BACKGROUND: Prostate cancer (PCa) refers to malignant tumors derived from prostate epithelial cells, whose morbidity and mortality rates have been increasing every year. Although new drugs for treating prostate cancer continue to emerge, the unclear mechanism underlying drug targets limits this therapy, thereby constraining identification of effective therapeutic targets. Although GDP dissociation inhibitor 2(GDI2) is highly expressed and closely associated with occurrence and development of many tumors, its role in prostate cancer remains unclear. In this study, we investigated the role of GDI2 and elucidated its underlying mechanism of action in prostate cancer. Moreover, we screened chemotherapeutic drugs that affect GDI2 expression with a view of identifying novel targets for diagnosis and treatment of prostate cancer. METHODS: We performed sequence analyses and functional assays to precisely elucidate the GDI2 role in prostate cancer. Moreover, we induced tumorigenesis in nude mice to verify the role of GDI2 in vivo. Finally, we used the CCK8 assay to ascertain the most suitable IC50 across the three drugs and performed quantitative real time polymerase chain reaction (qRT-PCR) and Western Blot to analyze the effects of drugs on expression of GDI2, p75NTR, and p-NFκB. RESULTS: GDI2 was up-regulated in prostate cancer cells and tissues. Knocking down GDI2 suppressed cell proliferation but promoted cell apoptosis. Interestingly, knocking down GDI2 activated the p75NTR signaling pathway, indicating, for the first time, that p75NTR is negatively correlated with GDI2 expression. CONCLUSION: Taken together, these results indicate that GDI2 is a therapeutic target of paclitaxel. Knocking down of GDI2 inhibits cell proliferation and promotes cell apoptosis via the p75NTR signaling pathway in prostate cancer. Notably, paclitaxel inhibits GDI2 expression, implying that GDI2 may be a promising therapeutic target in prostate cancer.

microRNA-1246-containing extracellular vesicles from acute myeloid leukemia cells promote the survival of leukemia stem cells via the LRIG1-meditated STAT3 pathway.

Cancer cells-secreted extracellular vesicles (EVs) have emerged as important mediators of intercellular communication in local and distant microenvironment. Our initial GEO database analysis identified the presence of differentially-expressed microRNA-1246 (miR-1246) in acute myeloid leukemia (AML) cell-derived EVs. Consequently, the current study set out to investigate the role of AML-derived EVs-packaged miR-1246 in leukemia stem cells (LSCs) bioactivities. The predicted binding between miR-1246 and LRIG1 was verified using dual luciferase reporter assay. Then, gain- and loss-of-function assays were performed in LSCs, where LSCs were co-cultured with AML cell-derived EVs to characterize the effects of miR-1246-containing EVs, miR-1246, LRIG1 and STAT3 pathway in LSCs. Our findings revealed, in AML cell-derived EVs, miR-1246 was highly-expressed and directly-targeted LRIG1 to activate the STAT3 pathway. MiR-1246 inhibitor or EV-encapsulated miR-1246 inhibitor was found to suppress the viability and colony formation abilities but promoted the apoptosis and differentiation of LSCs through inactivation of STAT3 pathway by up-regulating LRIG1. In addition, the inhibitory effects of AML cell-derived EVs carrying miR-1246 inhibitor on LSCs were substantiated by in vivo experiments. Collectively, our findings reveal that the repression of AML cell-derived EVs containing miR-1246 inhibitor alters the survival of LSCs by inactivating the LRIG1-mediated STAT3 pathway.

Roles Played by YY1 in Embryonic, Adult and Cancer Stem Cells.

Accumulating evidence strongly indicates that the presence of cancer stem cells (CSCs) leads to the emergence of worse clinical scenarios, such as chemo- and radiotherapy resistance, metastasis, and cancer recurrence. CSCs are a highly tumorigenic population characterized by self-renewal capacity and differentiation potential. Thus, CSCs establish a hierarchical intratumor organization that enables tumor adaptation to evade the immune response and resist anticancer therapy. YY1 functions as a transcription factor, RNA-binding protein, and 3D chromatin regulator. Thus, YY1 has multiple effects and regulates several molecular processes. Emerging evidence indicates that the development of lethal YY1-mediated cancer phenotypes is associated with the presence of or enrichment in cancer stem-like cells. Therefore, it is necessary to investigate whether and to what extent YY1 regulates the CSC phenotype. Since CSCs mirror the phenotypic behavior of stem cells, we initially describe the roles played by YY1 in embryonic and adult stem cells. Next, we scrutinize evidence supporting the contributions of YY1 in CSCs from a number of various cancer types. Finally, we identify new areas for further investigation into the YY1-CSCs axis, including the participation of YY1 in the CSC niche.

Possible treatment for UVB-induced skin injury: Anti-inflammatory and cytoprotective role of metformin in UVB-irradiated keratinocytes.

BACKGROUND: Excessive inflammation and cell death induced by ultraviolet (UV) cause skin photodamage. Metformin possesses anti-inflammatory and cytoprotective effects. However, whether metformin inhibits inflammation and cell death in UVB-induced acute skin damage is unclear. OBJECTIVE: To evaluate the anti-inflammatory and cytoprotective effects of metformin in vitro and in vivo. Furthermore, its potential mechanism has been explored. METHODS: Transcriptome sequencing and multiplex cytokines analysis were used to evaluate the validity of in vitro UVB-induced acute damage keratinocyte model and anti-inflammatory effects of metformin. We also determined the expression and nuclear translocation of CCAAT/enhancer-binding protein beta (C/EBPß), an important transcriptional factor of Interleukin-1beta (IL-1ß). Cell viability and cell death of keratinocytes were evaluated upon UVB irradiation in the presence or absence of metformin. 0.6% metformin cream was applied on UVB-irradiated mice to explore its pharmacological effects in vivo. RESULTS: Transcriptional landscape of 50 mJ/cm2 UVB-irradiated HaCaT cells is typical of UVB-induced acute damage keratinocyte model in vitro. Metformin alleviated transcription and secretion of IL-1ß, Tumor Necrosis Factor-alpha, and Fibroblast Growth Factor 2, expression and nuclear translocation of C/EBPß in this model. Metformin also protected keratinocytes from cell death caused by UVB-induced cellular secretions, which contributed to its cytoprotective effects. Topical administration of 0.6% metformin cream alleviated UVB-induced skin damage in mice. CONCLUSION: We proved the protective roles of metformin in UVB-challenged keratinocytes and UVB-irradiated mice, which indicated the potential value of metformin in topical therapy against skin photodamage.

Mediator subunit MED1 is required for E2A-PBX1-mediated oncogenic transcription and leukemic cell growth.

The chimeric transcription factor E2A-PBX1, containing the N-terminal activation domains of E2A fused to the C-terminal DNA-binding domain of PBX1, results in 5% of pediatric acute lymphoblastic leukemias (ALL). We recently have reported a mechanism for RUNX1-dependent recruitment of E2A-PBX1 to chromatin in pre-B leukemic cells; but the subsequent E2A-PBX1 functions through various coactivators and the general transcriptional machinery remain unclear. The Mediator complex plays a critical role in cell-specific gene activation by serving as a key coactivator for gene-specific transcription factors that facilitates their function through the RNA polymerase II transcriptional machinery, but whether Mediator contributes to aberrant expression of E2A-PBX1 target genes remains largely unexplored. Here we show that Mediator interacts directly with E2A-PBX1 through an interaction of the MED1 subunit with an E2A activation domain. Results of MED1 depletion by CRISPR/Cas9 further indicate that MED1 is specifically required for E2A-PBX1-dependent gene activation and leukemic cell growth. Integrated transcriptome and cistrome analyses identify pre-B cell receptor and cell cycle regulatory genes as direct cotargets of MED1 and E2A-PBX1. Notably, complementary biochemical analyses also demonstrate that recruitment of E2A-PBX1 to a target DNA template involves a direct interaction with DNA-bound RUNX1 that can be further stabilized by EBF1. These findings suggest that E2A-PBX1 interactions with RUNX1 and MED1/Mediator are of functional importance for both gene-specific transcriptional activation and maintenance of E2A-PBX1-driven leukemia. The MED1 dependency for E2A-PBX1-mediated gene activation and leukemogenesis may provide a potential therapeutic opportunity by targeting MED1 in E2A-PBX1+ pre-B leukemia.

Oligosaccharides increase the genotoxic effect of colibactin produced by pks+ Escherichia coli strains.

BACKGROUND: Colibactin is a genotoxin that induces DNA double-strand breaks that may lead to carcinogenesis and is produced by Escherichia coli strains harboring the pks island. Human and animal studies have shown that colibactin-producing gut bacteria promote carcinogenesis and enhance the progression of colorectal cancer through cellular senescence and chromosomal abnormalities. In this study, we investigated the impact of prebiotics on the genotoxicity of colibactin-producing E. coli strains Nissle 1917 and NC101. METHODS: Bacteria were grown in medium supplemented with 20, 30 and 40 mg/mL of prebiotics inulin or galacto-oligosaccharide, and with or without 5 µM, 25 µM and 125 µM of ferrous sulfate. Colibactin expression was assessed by luciferase reporter assay for the clbA gene, essential for colibactin production, in E. coli Nissle 1917 and by RT-PCR in E. coli NC101. The human epithelial colorectal adenocarcinoma cell line, Caco-2, was used to assess colibactin-induced megalocytosis by methylene blue binding assay and genotoxicity by γ-H2AX immunofluorescence analysis. RESULTS: Inulin and galacto-oligosaccharide enhanced the expression of clbA in pks+ E. coli. However, the addition of 125 µM of ferrous sulfate inhibited the expression of clbA triggered by oligosaccharides. In the presence of either oligosaccharide, E. coli NC101 increased dysplasia and DNA double-strand breaks in Caco-2 cells compared to untreated cells. CONCLUSION: Our results suggest that, in vitro, prebiotic oligosaccharides exacerbate DNA damage induced by colibactin-producing bacteria. Further studies are necessary to establish whether oligosaccharide supplementation may lead to increased colorectal tumorigenesis in animal models colonized with pks+ E. coli.

Reduced hepatic global hydroxymethylation in mice treated with non-genotoxic carcinogens is transiently reversible with a methyl supplemented diet.

Non-genotoxic carcinogens (NGCs) are known to cause perturbations in DNA methylation, which can be an early event leading to changes in gene expression and the onset of carcinogenicity. Phenobarbital (PB) has been shown to alter liver DNA methylation and hydroxymethylation patterns in mice in a time dependent manner. The goals of this study were to assess if clofibrate (CFB), a well-studied rodent NGC, would produce epigenetic changes in mice similar to PB, and if a methyl donor supplementation (MDS) would modulate epigenetic and gene expression changes induced by phenobarbital. CByB6F1 mice were treated with 0.5% clofibrate or 0.14% phenobarbital for 7 and 28 days. A subgroup of PB treated and control mice were also fed MDS diet. Liquid Chromatography-Ionization Mass Spectrometry (LC-MS) was used to quantify global liver 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) levels. Gene expression analysis was conducted using Affymetrix microarrays. A decrease in liver 5hmC but not 5mC levels was observed upon treatment with both CFB and PB with varying time of onset. We observed moderate increases in 5hmC levels in PB-treated mice when exposed to MDS diet and lower expression levels of several phenobarbital induced genes involved in cell proliferation, growth, and invasion, suggesting an early modulating effect of methyl donor supplementation. Overall, epigenetic profiling can aid in identifying early mechanism-based biomarkers of non-genotoxic carcinogenicity and increases the quality of cancer risk assessment for candidate drugs. Global DNA methylation assessment by LC-MS is an informative first step toward understanding the risk of carcinogenicity.