Non-tumorigenic Epithelial Cells Research Articles

Cytotoxic activity and apoptosis induction by a series Ag(I)-NHC complexes on human breast cancer cells and non-tumorigenic epithelial cell line

The main problems encountered in treatment with anticancer drugs, undesired side effects, and toxicity. One of the most important parameters in cell transport is the lipophilic and solubility property of the drug. Enough with the potential effects, side effects with minimal demand for new anticancer compounds, mechanisms of action of the compound can meet because of increased efforts to be clarified. In this case, scientists were encouraged to do new research. In particular, the organometallic compounds are one of the topics focused lately. Ag(I)-NHC complexes are one of the most important classes of organometallic compounds. Although the anticancer activity of Ag(I)-NHC complexes have been known recently times, the anticancer effects of 2-morpholino ethyl substituted benzimidazolium derivative, lipophilic, and solubility properties. Ag(I)-NHC complexes have not unknown yet. Therefore, we aimed to investigate of cytotoxic effect and apoptosis mechanism on breast cancer cell lines (MCF7), breast adenocarcinoma cell lines (MDA-MB-231), and non-tumorigenic epithelium cell lines (MCF 10A) of new Ag(I)-NHC complexes that derivative from morpholine-linked benzimidazole, were synthesized and antimicrobial activity was determined in our previous study. The cytotoxicity was determined by the MTS method, and the apoptosis mechanisms were determined the cell cycle, Annexin V, and caspase-3 analysis. A new benzimidazolium salt bearing morpholino ethyl substituent (2) was synthesized. This benzimidazolium salt was characterized by NMR and FT-IR spectroscopic method and elemental analysis technique. Also, the structure of the new benzimidazolium salt was confirmed by single-crystal X-ray diffraction. Ag(I)-NHC complexes inhibited the growth of MCF7 and MDA-MB-231 cells depending on the dosage and time. The complexes 3a and 3b exhibited a significant difference p < 0.05; p < 0.001; and p < 0.001 level depend on depending on the increase in concentration on cancer cells. All compound induced by apoptosis was associated with stopping the cell cycle in phase G1 and the caspase-3 activity exhibited. The complex 3c was the lowest number of caspase-activating cells (2.1%) compared with both the control and other complexes in MDA-MB-231 cells. But the complex 3a was the highest number of caspase-activating cells (% 9.6). These findings have shown that these new Ag(I)-NHC complexes can be important new anticancer agents for breast cancer treatments.

Involvement of mTOR/Survivin signaling pathway in TUA(2β, 3β, 23-trihydroxy-urs-12-ene-28-olic acid)-induced apoptosis in human gastric cancer cell line BGC823 cells

Ethno-pharmacological relevanceA natural ursolic compound, 2β,3β,23-trihydroxy-urs-12-ene-28-olic acid (TUA) was isolated from the root of Actinidiafulvicoma Hance. (A.fulvicoma Radix), which is used as a traditional hebal medicine to cure innominate inflammation of unknown origin of the digestive tract in the She nationality.Aim of the study: The aim of present study was to investigate the effects of TUA on gastric cancer and to clarify the potential mechanisms in human gastric cancer cell line BGC823 cells in vitro and in vivo. Materials and methodsCell proliferation, apoptosis, cell cycle, autophagy were all measured by MTS assay, flow cytometry following exposure to TUA. The mRNA expressions of PI3K, AKT, mTOR, P70S6K, Survivin and the protein expressions of p-PI3K, p-AKT, p-mTOR, p-P70S6K, Survivin were determined by qRT-PCR and Western blotting analysis, respectively. In vivo antitumor activity of TUA was assessed in a xenograft model. ResultsIn vitro studies showed that TUA significantly suppressed the viability of BGC823 cells in a concentration- and time-dependent manner but not GES-1 non-tumorigenic human gastric epithelial cells. TUA also significantly increased the apoptosis rate and the sub G2 population by cell cycle analysis in a concentration dependent manner. Exposure to TUA decreased PI3K, AKT, mTOR, P70S6K, Survivin mRNA, inhibited the phosphorylation of major receptors involved in autophagy and apoptosis, such as PI3K, AKT, mTOR and P70S6K, while reduced the expression of Survivin in BGC cells. In vivo studies showed that TUA decreased tumor volume and tumor weight and also down regulated the autophagy-related proteins expression. ConclusionsTUA occupies underlying antitumor effects, the potential mechanisms may involve the suppression of mTOR/Survivin pathways connected to autophagy and the activation of apoptotic pathways in gastric cancer cells.

Extracellular Neuroglobin as a Stress-Induced Factor Activating Pre-Adaptation Mechanisms against Oxidative Stress and Chemotherapy-Induced Cell Death in Breast Cancer.

Components of tumor microenvironment, including tumor and/or stromal cells-derived factors, exert a critical role in breast cancer (BC) progression. Here we evaluated the possible role of neuroglobin (NGB), a monomeric globin that acts as a compensatory protein against oxidative and apoptotic processes, as part of BC microenvironment. The extracellular NGB levels were evaluated by immunofluorescence of BC tissue sections and by Western blot of the culture media of BC cell lines. Moreover, reactive oxygen species (ROS) generation, cell apoptosis, and cell migration were evaluated in different BC cells and non-tumorigenic epithelial mammary cells treated with BC cells (i.e., Michigan Cancer Foundation-7, MCF-7) conditioned culture media and extracellular NGB. Results demonstrate that NGB is a component of BC microenvironment. NGB is released in tumor microenvironment by BC cells only under oxidative stress conditions where it can act as autocrine/paracrine factor able to communicate cell resilience against oxidative stress and chemotherapeutic treatment.

Melflufen, a peptide-conjugated alkylator, is an efficient anti-neo-plastic drug in breast cancer cell lines.

Melphalan flufenamide (hereinafter referred to as “melflufen”) is a peptide‐conjugated drug currently in phase 3 trials for the treatment of relapsed or refractory multiple myeloma. Due to its lipophilic nature, it readily enters cells, where it is converted to the known alkylator melphalan leading to enrichment of hydrophilic alkylator payloads. Here, we have analysed in vitro and in vivo the efficacy of melflufen on normal and cancerous breast epithelial lines. D492 is a normal‐derived nontumorigenic epithelial progenitor cell line whereas D492HER2 is a tumorigenic version of D492, overexpressing the HER2 oncogene. In addition we used triple negative breast cancer cell line MDA‐MB231. The tumorigenic D492HER2 and MDA‐MB231 cells were more sensitive than normal‐derived D492 cells when treated with melflufen. Compared to the commonly used anti‐cancer drug doxorubicin, melflufen was significantly more effective in reducing cell viability in vitro while it showed comparable effects in vivo. However, melflufen was more efficient in inhibiting metastasis of MDA‐MB231 cells. Melflufen induced DNA damage was confirmed by the expression of the DNA damage proteins ƴH2Ax and 53BP1. The effect of melflufen on D492HER2 was attenuated if cells were pretreated with the aminopeptidase inhibitor bestatin, which is consistent with previous reports demonstrating the importance of aminopeptidase CD13 in facilitating melflufen cleavage. Moreover, analysis of CD13high and CD13low subpopulations of D492HER2 cells and knockdown of CD13 showed that melflufen efficacy is mediated at least in part by CD13. Knockdown of LAP3 and DPP7 aminopeptidases led to similar efficacy reduction, suggesting that also other aminopeptidases may facilitate melflufen conversion. In summary, we have shown that melflufen is a highly efficient anti‐neoplastic agent in breast cancer cell lines and its efficacy is facilitated by aminopeptidases.

W-Band Millimeter Waves Targeted Mortality of H1299 Human Lung Cancer Cells without Affecting Non-Tumorigenic MCF-10A Human Epithelial Cells In Vitro

Therapeutically effective treatments of cancer are limited. To calibrate the efficiency of the novel technique we recently discovered to modulate cancer cell viability using tuned electromagnetic fields; H1299 human lung cancer cells were irradiated in a sweeping regime of W-band (75–105 GHz) millimeter waves (MMW) at 0.2 mW/cm2 (2 W/m2). Effects on cell morphology, cell death and senescence were examined and compared to that of non-tumorigenic MCF-10A human epithelial cells. MMW irradiation led to alterations of cell and nucleus morphology of H1299 cells, significantly increasing mortality and senescence over 14 days of observation. Extended irradiation of 10 min duration resulted in complete death of exposed H1299 cell population within two days, while healthy MCF-10A cells remained unaffected even after 16 min of irradiation under the same conditions. Irradiation effects were observed to be specific to MMW treated H1299 cells and absent in the control group of non-irradiated cells. MMW irradiation affected nuclear morphology of H1299 cells only and not of the immortalized MCF-10A cells. Irradiation with low intensity MMW shows an antitumor effect on H1299 lung cancer cells. This method provides a novel treatment modality enabling targeted specificity for various types of cancers.

The architecture of co-culture spheroids regulates tumor invasion within a 3D extracellular matrix.

Tumor invasion, the process by which tumor cells break away from their primary tumor and gain access to vascular systems, is an important step in cancer metastasis. Most current 3D tumor invasion assays consisted of single tumor cells embedded within an extracellular matrix (ECM). These assays taught us much of what we know today on how key biophysical (e.g. ECM stiffness) and biochemical (e.g. cytokine gradients) parameters within the tumor microenvironment guided and regulated tumor invasion. One limitation of the single tumor cell invasion assay was that it did not account for cell-cell adhesion within the tumor. In this article, we developed a micrometer scale 3D co-culture spheroid invasion assay that was compatible with microscopic imaging. Micrometer scale co-culture spheroids (1:1 ratio of metastatic breast cancer MDA-MB-231 and non-tumorigenic epithelial MCF-10A cells) were made using an array of microwells, and then were embedded within a collagen matrix in a microfluidic platform. Real time imaging of tumor spheroid invasion revealed that the spatial distribution of the two cell types within the tumor spheroid critically regulated tumor invasion. This work linked tumor architecture with tumor invasion and highlighted the importance of the biophysical cues within the bulk of the tumor in tumor invasion.

Tumor spheroids under perfusion within a 3D microfluidic platform reveal critical roles of cell-cell adhesion in tumor invasion

Tumor invasion within the interstitial space is critically regulated by the force balance between cell-extracellular matrix (ECM) and cell-cell interactions. Interstitial flows (IFs) are present in both healthy and diseased tissues. However, the roles of IFs in modulating cell force balance and subsequently tumor invasion are understudied. In this article, we develop a microfluidic model in which tumor spheroids are embedded within 3D collagen matrices with well-defined IFs. Using co-cultured tumor spheroids (1:1 mixture of metastatic and non-tumorigenic epithelial cells), we show that IFs downregulate the cell-cell adhesion molecule E-cadherin on non-tumorigenic cells and promote tumor invasion. Our microfluidic model advances current tumor invasion assays towards a more physiologically realistic model using tumor spheroids instead of single cells under perfusion. We identify a novel mechanism by which IFs can promote tumor invasion through an influence on cell-cell adhesion within the tumor and highlight the importance of biophysical parameters in regulating tumor invasion.

Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity

AbstractIn this study, two ethanolic extracts, fromStokesia aster(Slae26) andGeranium pratense(Gpre36) respectively, were evaluated in order to assess the cytotoxic activity and potential antiproliferative activity upon the nontumorigenic human epithelial cell line derived from the mammary gland (MCF-12A) and the human breast tumor cell line (BT-20). The selection of the plant species was done on the basis of their chemical composition, specifically combinations of luteolin derivatives with caffeic and gallic acid derivatives. Therefore, theS. laevisethanolic extract proved its capacity to inhibit the viability of both normal and tumor breast cell lines (i.e., up to 90% cell viability inhibition, IC50= 42 µg/mL). On the contrary, theG. pratenseethanolic extract proved weak stimulatory effects on the viability of the two human breast cell lines studied. The obtained results were discussed in the contexts of computational studies and drug-likeness bioactivity of seven common luteolin derivatives: luteolin, luteolin-7-O-glucoside/cynaroside, luteolin-5-O-glucoside/galuteolin, luteolin-6-C-glucoside/isoorientin, luteolin-8-C-glucoside/orientin, luteolin-3′,4′-di-O-glucoside and luteolin-7,3′-di-O-glucoside. Computational studies have revealed that the hydrophilic behavior of luteolin derivatives (log Pvalues) does not follow other tested parameters (e.g., polar surface area values), possibly explaining different efficacy concerning the biological propertiesin vitro. These predictions could be a starting point for studies on the biochemical mechanism by which luteolin derivatives induce biological effects.

Selective photodynamic effects on cervical cancer cells provided by P123 Pluronic®-based nanoparticles modulating hypericin delivery

At present, cervical cancer is the fourth leading cause of cancer among women worldwide with no effective treatment options. In this study we aimed to evaluate the efficacy of hypericin (HYP) encapsulated on Pluronic® P123 (HYP/P123) photodynamic therapy (PDT) in a comprehensive panel of human cervical cancer-derived cell lines, including HeLa (HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16 and 18-positive), and C33A (HPV-negative), compared to a nontumorigenic human epithelial cell line (HaCaT). Were investigated: (i) cell cytotoxicity and phototoxicity, cellular uptake and subcellular distribution; (ii) cell death pathway and cellular oxidative stress; (iii) migration and invasion. Our results showed that HYP/P123 micelles had effective and selective time- and dose-dependent phototoxic effects on cervical cancer cells but not in HaCaT. Moreover, HYP/P123 micelles accumulated in endoplasmic reticulum, mitochondria and lysosomes, resulting in photodynamic cell death mainly by necrosis. HYP/P123 induced cellular oxidative stress mainly via type II mechanism of PDT and inhibited cancer cell migration and invasion mainly via MMP-2 inhibition. Taken together, our results indicate a potentially useful role of HYP/P123 micelles as a platform for HYP delivery to more specifically and effectively treat cervical cancers through PDT, suggesting they are worthy for in vivo preclinical evaluations.

Abstract A109: MicroRNA-4719 and microRNA-6756-5p correlate with aggressive prostate cancer progression in African American men through regulation of Interleukin-24

Abstract Prostate cancer (PCa) incidence and mortality are highest in African American men (AAM) and the molecular mechanisms underlying the racial disparities in PCa are unclear. Interleukin-24 (IL-24), a tumor suppressor whose expression is lost in most human cancers, correlates with cancer progression. Also, microRNAs (miRs) are dysregulated in cancers. microRNA target prediction algorithm tools identified miRs, miR-4719 and miR-6556-5p, as putative regulators of IL-24. This study elucidates the expression profile and role of miR-4719 and miR-6756-5p as regulators of IL-24 in PCa biology of AAM. Our work compares five different PCa cell lines: E006AA (AAM, indolent), E006AA-hT (AAM, aggressive), DU-145 (CM, aggressive), PC-3 (CM, aggressive) to a nontumorigenic prostate epithelial cell line, RWPE1 (CM). qRT-PCR analysis shows that miR-4719 and miR-6756-5p are significantly overexpressed in all PCa cell lines (by &amp;gt;2-fold) compared to RWPE-1. Both miR-4719 (&amp;gt;2 fold) and miR-6756-5p (&amp;gt;50%) are higher in aggressive PCa compared to the indolent PCa, indicating their gain could be an early event in PCa progression. Moreover, miR-4719 and miR-6756-5p are significantly overexpressed in the aggressive PCa of AAM (E006AA-hT) compared to aggressive PCas for CM (PC-3 and DU-145). Interestingly, both miR-4719 and miR-6756-5p expression were higher by (&amp;gt;3-fold) in the aggressive AAM cell line E006AA-hT compared to indolent AAM cell line- E006AA. Thus, miR-4719 and miR-6756-5p may play a role in racial disparity. Using oligonucleotide mimics and inhibitors, we evaluated the functional role of these miRs in the AAM cell lines, E006AA and E006AA-hT. MTT assays revealed that inhibition of miR-4719 and miR-6756-5p significantly decreases proliferation (&amp;gt;40%), while overexpression of both miRs increases proliferation (&amp;gt;20%). Inhibition of miR-4719 and miR-6756-5p further decreased the proliferation of the aggressive E006AA-hT by an extra 20%, compared to indolent E006AA. In contrast, overexpression of both miRs further increased the proliferation of E006AA-hT also by an extra 20%, compared to E006AA. Wound healing assays reveal that inhibition of miR-4719 and miR-6756-5p reduced migration by ~50% compared to the negative control (NC). Strikingly, overexpression of both miRs increased migration by at least 2- and 4-fold, respectively. We observed that IL-24 was downregulated in all PCa cells compared to RWPE-1, suggesting a possible role of these miRs in suppressing IL-24. qRT-PCR analysis show inhibition of miR-4719 and miR-6756-5p significantly increases the expression of IL-24 (by ~2-fold) in PCa cells compared to the NC. In contrast, overexpression of both miRs reduces the expression of IL-24. Our findings indicate that miR-4719 and miR-6756-5p may regulate IL-24 expression and may be biomarkers that can differentiate between indolent and aggressive PCa in AAM. Strategies to inhibit miR-4719 and miR-6756-5p expression to increase IL-24 in PCa could have therapeutic efficacy in AAM. Citation Format: Dibash K. Das, Leah Persaud, Moira Sauane. MicroRNA-4719 and microRNA-6756-5p correlate with aggressive prostate cancer progression in African American men through regulation of Interleukin-24 [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A109.

Abstract B074: The long noncoding RNA from PVT1 exon 9 is overexpressed in prostate cancer in Black males and induces malignant transformation, invasiveness, and castration-resistance in prostate epithelial cells

Abstract Prostate cancer (PCa) is the most common non-skin cancer and the second leading cause of cancer-related death for men in the United States. PCa is the greatest source of cancer-related mortality in males of African ancestry. One of the most important susceptibility loci for cancer is the 8q24 human chromosomal region. The non-protein coding gene locus plasmacytoma variant translocation 1 (PVT1) is located at 8q24 and is dysregulated in different cancers. PVT1 gives rise to several alternatively spliced transcripts and microRNAs. There are at least twelve exons of PVT1, which make separate transcripts, and likely have different functions. The transcript from PVT1 exon 9 is significantly overexpressed in PCa tissues in comparison to normal prostate tissues obtained from Black males. Both transient and stable overexpression of PVT1 exon 9 induce significantly increased prostate epithelial cell proliferation, migration, and proliferating cell nuclear antigen (PCNA) expression. Notably, implantation into mice of a novel subline of a non-tumorigenic prostate epithelial cell line stably overexpressing PVT1 exon 9 results in the formation of malignant tumors with features characteristic of aggressive PCa. Further, PVT1 exon 9 overexpression significantly induces castration-resistance in prostate epithelial cells. Consequently, PVT1 exon 9 expression is important for PCa initiation and progression and may have potential diagnostic and therapeutic applications in PCa in Black males. Citation Format: Gargi Pal, Jeannette Huaman, Fayola Levine, Akintunde Orunmuyi, E. Oluwabunmi Olapade-Olaopa, Olorunseun O. Ogunwobi. The long noncoding RNA from PVT1 exon 9 is overexpressed in prostate cancer in Black males and induces malignant transformation, invasiveness, and castration-resistance in prostate epithelial cells [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B074.

Berberine-induced nucleolar stress response in a human breast cancer cell line

We investigated the novel molecular mechanisms of the antitumor effect of berberine. In this study, two different human cell lines (breast cancer MCF7 cells and non-tumorigenic epithelial MCF12A cells) were treated with various concentrations of berberine. Treatment with 1 and 10 μM berberine inhibited proliferation with G0/G1 cell cycle arrest in both cell lines, and treatment with 100 μM berberine triggered a marked level of cell death in MCF7 cells but not in MCF12A cells. Berberine increased the level of p53 protein and of its target p21 both time- and dose-dependently in MCF7 cells. At any concentration of berberine, immediate uptake (within 15 min) followed by predominantly mitochondrial accumulation were observed by confocal microscopy in both cell lines. At high concentrations (10 or 100 μM), accumulation in the nucleolus became prominent after the transition to the nucleoplasm, especially remarkable in MCF7 cells. Therefore, we evaluated the possibility of berberine-induced nucleolar stress and observed the disappearance of ribosomal protein (RP)L5 from the nucleolus and accumulation of p53 protein in the nucleus after treatment with 10 or 100 μM berberine in MCF7 cells. We also detected the accumulation of RPL5 and RPL11 in the nucleoplasm fraction where they bind to Mdm2. Moreover, downregulation of RPL5 inhibited berberine-driven induction of p53 and p21 and cell death in MCF7 cells. Whereas, in MCF12A cells, down-regulation of RPL5 had little effect on the growth inhibitory effect of high concentration of berberine. These results indicated that cell growth inhibition and cell death induced by higher doses (>10 μM) of berberine in MCF7 cells were due to the upregulation of p53 under the nucleolar stress response caused by a significant accumulation of berberine in the nucleoli.

Synthesis, biological evaluation and molecular docking studies of novel 1,2,3-triazole tethered chalcone hybrids as potential anticancer agents

As a part of our ongoing effort in a way to develop potential anti-cancer agents, a novel series of nine 1,2,3-triazole tethered chalcone hybrids were synthesized in good yields from suitable reaction procedures and were further characterized by various analytical techniques. All the newly synthesized compounds were screened for their potent in-vitro cytotoxicity against human breast cancer (MCF-7),cervical cancer (HeLa) and MDA-MB-231 cell lines. Further the selectivity index(SI) of potent compounds with non-tumorigenic MCF-10a epithelial cells enables the target molecule less toxic effect on normal cells. Compounds with different minimal concentration ranging from 0.625 μM to 10 μM respectively displayed potent cytotoxic evaluations towards cancer cells by MTT assay in terms of half-maximal inhibitory concentration of compound required to inhibit cell viability. Most of the screened derivatives (7a-i) demonstrated moderate to promising cytotoxic activity. Some of the derivatives, predominantly like 7d, 7g and 7i are the major compounds which shown promising cytotoxic activity with lower IC50 value compared to standard drug cisplatin. In addition, to these in vitro compound activity relationships we further supported the compounds as potent anticancer agents with less toxicity by in-silico molecular docking studies and ADME properties with maximum dock scores.

MiR-200b/200a/429 Cluster Stimulates Ovarian Cancer Development by Targeting ING5.

Ovarian cancer is the second most common gynaecological malignancy, and microRNAs (miRNAs) play important role in the cancer development. Here, we found that the level of miR-200b/200a/429 was significantly increased in serum and tumor tissues of patients with stage-I ovarian cancer. Consistent with these results, we detected increased expression levels of miR-200b/200a/429 in ovarian cancer cell lines compared with the human nontumorigenic ovarian epithelial cell line T80. The overexpression of miR-200b/200a/429 in T80 cells stimulated proliferation and caused their growth in soft agar and tumor formation in nude mice. Furthermore, we determined that miR-200b/200a/429 targets inhibitor of growth family 5 (ING5) and that the overexpression of ING5 can block miR-200b/200a/429-induced T80 cell transformation and tumorigenesis. Our findings suggest that miR-200b/200a/429 may be a useful biomarker for the early detection of ovarian cancer and that miR-200b/200a/429 significantly contributes to ovarian cancer development through ING5.

Decreased miR-124 contributes to the epithelial-mesenchymal transition phenotype formation of lung adenocarcinoma cells via targeting enhancer of zeste homolog 2

IntroductionMiR-124, a tumor suppressor, is involved in regulating various cellular processes. The purpose of this study was to investigate the possible function of miR-124 in LA (lung adenocarcinoma) cells. AimsMiR-124 expression levels in the 54 pairs of LA tissues (and corresponding non-tumor tissues) obtained at the Sixth People’s Hospital of Yancheng City and in LA cells were assessed by qRT-PCR. Colony formation assay, wound healing assay, transwell assays, attachment/detachment, western blotting and immunofluorescence assays were performed to assess the function of miR-124 on proliferation, migration and epithelial-to-mesenchymal (EMT) phenotypes in LA cells in vitro. Enhancer of zeste homolog 2 (EZH2) is identified as a target of miR-124 by bioinformatics analysis and luciferase reporter assays. Rescue assays were applied to verify the relationship between miR-124 and EZH2. ResultsMiR-124 was down-regulated in LA tissues (compared to adjacent non-tumor tissues), and was down-regulated in 3 out of 4 lung cancer cell lines compared to immortalized, non-tumorigenic bronchial epithelial cells. Forced expression of miR-124 significantly suppressed tumor cell proliferation, migration and inhibited the EMT process. On the contrary, deletion of miR-124 could obviously promote cell proliferation, migration and facilitate the formation of EMT phenotype. Bioinformatics analysis and luciferase reporter assays confirmed that EZH2 was a target gene of miR-124 and was negatively correlated with the level of miR-124 in cancer tissues. ConclusionOur current study suggested that miR-124 was a tumor suppressor in LA, and miR-124 was associated with LA cell EMT phenotype formation via targeting EZH2.

Investigating Tunneling Nanotubes in Cancer Cells: Guidelines for Structural and Functional Studies through Cell Imaging.

By allowing insured communication between cancer cells themselves and with the neighboring stromal cells, tunneling nanotubes (TNTs) are involved in the multistep process of cancer development from tumorigenesis to the treatment resistance. However, despite their critical role in the biology of cancer, the study of the TNTs has been announced challenging due to not only the absence of a specific biomarker but also the fragile and transitory nature of their structure and the fact that they are hovering freely above the substratum. Here, we proposed to review guidelines to follow for studying the structure and functionality of TNTs in tumoral neuroendocrine cells (PC12) and nontumorigenic human bronchial epithelial cells (HBEC-3, H28). In particular, we reported how crucial is it (i) to consider the culture conditions (culture surface, cell density), (ii) to visualize the formation of TNTs in living cells (mechanisms of formation, 3D representation), and (iii) to identify the cytoskeleton components and the associated elements (categories, origin, tip, and formation/transport) in the TNTs. We also focused on the input of high-resolution cell imaging approaches including Stimulated Emission Depletion (STED) nanoscopy, Transmitted and Scanning Electron Microscopies (TEM and SEM). In addition, we underlined the important role of the organelles in the mechanisms of TNT formation and transfer between the cancer cells. Finally, new biological models for the identification of the TNTs between cancer cells and stromal cells (liquid air interface, ex vivo, in vivo) and the clinical considerations will also be discussed.

Proteomic Analysis of Blood Exosomes from Healthy Females and Breast Cancer Patients Reveals an Association between Different Exosomal Bioactivity on Non-tumorigenic Epithelial Cell and Breast Cancer Cell Migration in Vitro.

Exosomes are important intercellular communication vehicles, secreted into body fluids by multiple cell types, including tumor cells. They contribute to the metastatic progression of tumor cells through paracrine signalling. It has been recently discovered that blood circulating exosomes contain distinguishable fractions of free and cell-surface-associated vesicles. We evaluated the influence of protein cargoes from exosomes from plasma, and exosomes from the total blood of healthy females (HFs) and breast cancer patients (BCPs), on cell motility. We conducted a mass spectrometric analysis of exosomal contents isolated from samples using ultrafiltration and ultracentrifugation approaches and verified their nature using transmission electron microscopy, nanoparticle tracking analysis and flow cytometry. We observed that malignant neoplasm-associated proteins in exosomes from BCP total blood were detected more often than in plasma (66% vs. 59%). FunRich analysis to assess Gene Ontology (GO) enrichment revealed that proteins with catalytic activities, transporter functions and protein metabolism activities were increased in exosomes from BCP blood. Finally, GO analysis revealed that proteomic profiles of exosomes from HF total blood were enriched with proteins inhibiting cell migration and invasion, which explains the low stimulating activity of exosomes from HF total blood on SKBR-3 cancer cell migration velocity. This allows exosomes to act as intermediaries providing intercellular communications through horizontal transfer of RNA and functionally active proteins, potentially affecting the development of both primary neoplasms and distant metastases.

The genomic landscape of 8-oxodG reveals enrichment at specific inherently fragile promoters.

8-Oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) is the most common marker of oxidative stress and its accumulation within the genome has been associated with major human health issues such as cancer, aging, cardiovascular and neurodegenerative diseases. The characterization of the different genomic sites where 8-oxodG accumulates and the mechanisms underlying its formation are still poorly understood. Using OxiDIP-seq, we recently derived the genome-wide distribution of 8-oxodG in human non-tumorigenic epithelial breast cells (MCF10A). Here, we identify a subset of human promoters that accumulate 8-oxodG under steady-state condition. 8-oxodG nucleotides co-localize with double strand breaks (DSBs) at bidirectional and CG skewed promoters and their density correlate with RNA Polymerase II co-occupancy and transcription. Furthermore, by performing OxiDIP-seq in quiescent (G0) cells, we found a strong reduction of oxidatively-generated damage in the majority of 8-oxodG-positive promoters in the absence of DNA replication. Overall, our results suggest that the accumulation of 8-oxodG at gene promoters occurs through DNA replication-dependent or -independent mechanisms, with a possible contribution to the formation of cancer-associated translocation events.

Beyond hemostasis: a snake venom serine protease with potassium channel blocking and potential antitumor activities

Snake venom serine proteases (SVSPs) are complex and multifunctional enzymes, acting primarily on hemostasis. In this work, we report the hitherto unknown inhibitory effect of a SVSP, named collinein-1, isolated from the venom of Crotalus durissus collilineatus, on a cancer-relevant voltage-gated potassium channel (hEAG1). Among 12 voltage-gated ion channels tested, collinein-1 selectively inhibited hEAG1 currents, with a mechanism independent of its enzymatic activity. Corroboratively, we demonstrated that collinein-1 reduced the viability of human breast cancer cell line MCF7 (high expression of hEAG1), but does not affect the liver carcinoma and the non-tumorigenic epithelial breast cell lines (HepG2 and MCF10A, respectively), which present low expression of hEAG1. In order to obtain both functional and structural validation of this unexpected discovery, where an unusually large ligand acts as an inhibitor of an ion channel, a recombinant and catalytically inactive mutant of collinein-1 (His43Arg) was produced and found to preserve its capability to inhibit hEAG1. A molecular docking model was proposed in which Arg79 of the SVSP 99-loop interacts directly with the potassium selectivity filter of the hEAG1 channel.

AhR ligands reactivate LINE-1 retrotransposon in triple-negative breast cancer cells MDA-MB-231 and non-tumorigenic mammary epithelial cells NMuMG

Breast cancer is the most common cancer type in females worldwide. Environmental exposure to pesticides affecting hormonal homeostasis does not necessarily induce DNA mutations but may influence gene expression by disturbances in epigenetic regulation. Expression of long interspersed nuclear element-1 (LINE-1) has been associated with tumorigenesis in several cancers. In nearly all somatic cells, LINE-1 is silenced by DNA methylation in the 5́′UTR and reactivated during disease initiation and/or progression. Strong ligands of aryl hydrocarbon receptor (AhR) activate LINE-1 through the transforming growth factor-β1 (TGF-β1)/Smad pathway. Hexachlorobenzene (HCB) and chlorpyrifos (CPF), both weak AhR ligands, promote cell proliferation and migration in breast cancer cells, as well as tumor growth in rat models. In this context, our aim was to examine the effect of these pesticides on LINE-1 expression and ORF1p localization in the triple-negative breast cancer cell line MDA-MB-231 and the non-tumorigenic epithelial breast cell line NMuMG, and to evaluate the role of TGF-β1 and AhR pathways. Results show that 0.5 μM CPF and 0.005 μM HCB increased LINE-1 mRNA expression through Smad and AhR signaling in MDA-MB-231. In addition, the methylation of the first sites in 5́′UTR of LINE-1 was reduced by pesticide exposure, although the farther sites remained unaffected. Pesticides modulated ORF1p localization in MDA-MB-231: 0.005 μM HCB and 50 μM CPF increased nuclear translocation, while both induced cytoplasmic retention at 0.5 and 5 μM. Moreover, both stimulated double-strand breaks, enhancing H2AX phosphorylation, coincidentally with ORF1p nuclear localization. In NMuMG similar results were observed, since they heighten LINE-1 mRNA levels. CPF effect was through AhR and TGF-β1 signaling, whereas HCB action depends only of AhR. In addition, both pesticides increase ORF1p expression and nuclear localization. Our results provide experimental evidence that HCB and CPF exposure modify LINE-1 methylation levels and induce LINE-1 reactivation, suggesting that epigenetic mechanisms could contribute to pesticide-induced breast cancer progression.