Premature senescence activation in DLD-1 colorectal cancer cells through adjuvant therapy to induce a miRNA profile modulating cellular death.

Cancer, and particularly colon cancer, is associated with an increasing number of cases resistant to chemotherapy. One approach to overcome this, and to improve the prognosis and outcome of patients, is the use of adjuvant therapy alongside the standard chemotherapy regiment. In the present study, the effect of deuterium-depleted water (DDW) as a potential modulator of adjuvant therapy on DLD-1 colorectal cancer models was assessed. A number of functionality assays were performed, including MTT, apoptosis and autophagy, and mitochondrial activity and senescence assays, in addition to assessing the capacity to modify the pattern of released miRNA via microarray technology. No significant effect on cell viability was identified, but an increase in mitochondrial activity and a weak pro-apoptotic effect were observed in the treated DLD-1 cells cultured in DDW-prepared medium compared with those grown in standard conditions (SC). Furthermore, the findings revealed the capacity of DDW medium to promote senescence to a higher degree compared with SC. The exosome-released miRNA pattern was significantly modified for the cells maintained in DDW compared with those maintained in SC. These findings suggest that DDW may serve as an adjuvant treatment; however, a better understanding of the underlying molecular mechanism of action will be useful for developing novel and efficient therapeutic strategies, in which the transcriptomic pattern serves an important role.

Overview upon miR-21 in lung cancer: focus on NSCLC.

Considering the high mortality rate encountered in lung cancer, there is a strong need to explore new biomarkers for early diagnosis and also improved therapeutic targets to overcome this issue. The implementation of microRNAs as important regulators in cancer and other pathologies expanded the possibilities of lung cancer management and not only. MiR-21 represents an intensively studied microRNA in many types of cancer, including non-small cell lung cancer (NSCLC). Its role as an oncogene is underlined in multiple studies reporting the upregulated expression of this sequence in patients diagnosed with this malignancy; moreover, several studies associated this increased expression of miR-21 with a worse outcome within NSCLC patients. The same pattern is supported by the data existent in the Cancer Genome Atlas (TCGA). The carcinogenic advantage generated by miR-21 in NSCLC resides in the target genes involved in multiple pathways such as cell growth and proliferation, angiogenesis, invasion and metastasis, but also chemo- and radioresistance. Therapeutic modulation of miR-21 by use of antisense sequences entrapped in different delivery systems has shown promising results in impairment of NSCLC. Hereby, we review the mechanisms of action of miR-21 in cancer and the associated changes upon tumor cells together a focused perspective on NSCLC signaling, prognosis and therapy.

A miRNAs profile evolution of triple negative breast cancer cells in the presence of a possible adjuvant therapy and senescence inducer.

PURPOSE: Breast cancer is a highly heterogeneous disease with an increasing number of cases resistant to chemotherapy. To increase the response to therapy, different adjuvant systems are tested, like the case of deuterium-depleted water (DDW). METHODS: For this study, we selected as in vitro model the triple-negative breast cancer cell line MDA-MB-231 and we performed a series of microscopy-based functional tests (apoptosis, autophagy assays, senescence detection) and microarray evaluation of the miRNA profile in order to evaluate changes induced by cisplatin and DDW treatment at cellular and molecular level. RESULTS: Cisplatin treatment led to increased mitochondrial activity and autophagy for cells kept in DDW, compared with those in standard conditions (SC). We also observed that cells treated with DDW medium promoted senescence in a higher level than SC. The exosomal miRNAs released in cell culture revealed an altered pattern in the case of cells maintained in DDW compared to SC. CONCLUSION: DDW was proved to be non-toxic, and, when administered with cisplatin, to slightly increase the senescence of cancer cells, therefore, can be pondered as adjuvant therapeutic agent. However, future studies are needed to be done in order to further elucidate its mechanism of action.

Implications of dietary ω-3 and ω-6 polyunsaturated fatty acids in breast cancer.

Breast cancer represents one of the most common forms of cancer in women worldwide, with an increase in the number of newly diagnosed patients in the last decade. The role of fatty acids, particularly of a diet rich in ω-3 and ω-6 polyunsaturated fatty acids (PUFAs), in breast cancer development is not fully understood and remains controversial due to their complex mechanism of action. However, a large number of animal models and cell culture studies have demonstrated that high levels of ω-3 PUFAs have an inhibitory role in the development and progression of breast cancer, compared to ω-6 PUFAs. The present review focused on recent studies regarding the correlation between dietary PUFAs and breast cancer development, and aimed to emphasize the main molecular mechanisms involved in the modification of cell membrane structure and function, modulation of signal transduction pathways, gene expression regulation, and antiangiogenic and antimetastatic effects. Furthermore, the anticancer role of ω-3 PUFAs through the modulation of microRNA expression levels was also reviewed.

MiR-181 family-specific behavior in different cancers: a meta-analysis view.

The involvement of microRNAs in malignant transformation and cancer progression was previously grounded. The observations made by multiple published studies led to the conclusion that some of these small sequences could be eventually used as biomarkers for diagnosis/prognosis. This meta-analysis investigated whether microRNA-181 family members could predict the outcome of patients carrying different types of cancer. We searched the PubMed and Embase databases for studies evaluating the expression levels of miR-181a/b/c/d in patients with cancer, selecting the publications that assessed the relation between low and high levels of one of these four microRNAs and patients' outcome. Hazard ratios (HRs) or risk ratios (RRs) were extracted from the studies, and random-effect model was performed to investigate the role of miR-181 in the outcome of these patients. The meta-analysis comprised 26 studies including 2653 cancer patients from 6 countries. The results showed significant association between the expression of miR-181 family members and colorectal cancer. Considering the heterogeneity of the pathologies, the analysis, including all types of cancer and the expression of all the miR-181 family members together, showed no association with distinct outcome (HR = 1.099, p = 0.435). When the analysis was performed on each microRNA separately, the expression of miR-181c was significantly associated with the outcome of patients with cancer (HR = 2.356, p = 0.011) and miR-181a expression levels significantly correlated with survival in patients with non-small-cell lung cancer (HR = 0.177, p < 0.05). This meta-analysis revealed evidence regarding the involvement of miR-181 family members in the outcome of patients with some types of cancer, according to their expression level.

Exosomes-Small Players, Big Sound.

Incipiently named extracellular vesicles, exosomes are forming now a separate class of cellular mediators with important functions in physiological and pathological states. Their ability to transfer information between cells through encapsulation of proteins, nucleic acids and lipids for the preservation of the homeostatic equilibrium is translated also in pathological conditions. The recipient cells react to the reception of foreign molecules adjusting their molecular state according to the enclosed message. Cancer cells, in order to influence the microenvironment and facilitate the malignant expanding, exploit this intercellular trafficking. Immune cells are also producing exosomes that ensure the transportation of immune mediators and signaling molecules between cells. Current experimental attempts are concentrated on the adjustment of exosomes level for therapeutic purposes, enrolment of these vesicles as diagnosis or prognosis tools and also exosomes' use as drug delivery vehicles or immune stimulatory agents.

The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression.

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarcinoma patients revealed that low levels of miR-205-5p are associated with an unfavorable prognostic compared to those with increased expression, demonstrating the possible clinical utility of miR-205-5p replacement. Exogenous administration of miRNA mimics was not associated with significant changes in cell viability or inflammatory pathways. Therefore, the proposed strategy is aiming towards inhibition of metastasis and limitation of the tumor borders in advanced stages patients in order to prolong the survival time and to increase the efficiency of the current therapeutic strategies.

Genetic alterations in sporadic triple negative breast cancer.

BACKGROUND: Recent studies have aimed to identify gene mutation profiles to explain the cause of TNBC therapy limitations. METHODS: The purpose of our study was to use Next Generation Sequencing (NGS) of 46 genes with a well-defined role in cancer in a cohort of TNBC patients in order to identify novel markers that could lead to the development of strategic, adjuvant, gene-targeted therapies. RESULTS: A total of 118 gene mutations in 35 genes, 75 mutations in BRCA1 and 92 mutations in BRCA2 were identified. The clinical assessment of the identified mutations showed 27 to be possibly damaging and 59 to be damaging. TP53, KDR, PIK3CA (rs3729687), ATM, AKT1 and KIT were among the most frequently mutated genes in our TNBC cohort. The SNP AKT1 (rs3730358) was suggested to modify the risk of breast cancer. SNP PIK3CA (rs3729687) is a damaging mutation that we found to be correlated with the prognosis of TNBC. The survival curve analysis showed that the presence of AKT1, TP53, KDR, KIT, BRCA1 and BRCA2 mutations is correlated with a poor prognosis. CONCLUSION: We show a strong association between TNBC and mutations in BRCA1/2 genes and the poor outcome of these patients. Moreover, we identified several other unknown mutations putatively associated with the poor prognosis of TNBC tumors. We also discovered novel mutations never before associated with breast cancer that could putatively account for the poor prognosis of the TNBC tumors.

A Looking-Glass of Non-coding RNAs in oral cancer.

Oral cancer is a multifactorial pathology and is characterized by the lack of efficient treatment and accurate diagnostic tools. This is mainly due the late diagnosis; therefore, reliable biomarkers for the timely detection of the disease and patient stratification are required. Non-coding RNAs (ncRNAs) are key elements in the physiological and pathological processes of various cancers, which is also reflected in oral cancer development and progression. A better understanding of their role could give a more thorough perspective on the future treatment options for this cancer type. This review offers a glimpse into the ncRNA involvement in oral cancer, which can help the medical community tap into the world of ncRNAs and lay the ground for more powerful diagnostic, prognostic and treatment tools for oral cancer that will ultimately help build a brighter future for these patients.

Understanding the Role of Non-Coding RNAs in Bladder Cancer: From Dark Matter to Valuable Therapeutic Targets.

The mortality and morbidity that characterize bladder cancer compel this malignancy into the category of hot topics in terms of biomolecular research. Therefore, a better knowledge of the specific molecular mechanisms that underlie the development and progression of bladder cancer is demanded. Tumor heterogeneity among patients with similar diagnosis, as well as intratumor heterogeneity, generates difficulties in terms of targeted therapy. Furthermore, late diagnosis represents an ongoing issue, significantly reducing the response to therapy and, inevitably, the overall survival. The role of non-coding RNAs in bladder cancer emerged in the last decade, revealing that microRNAs (miRNAs) may act as tumor suppressor genes, respectively oncogenes, but also as biomarkers for early diagnosis. Regarding other types of non-coding RNAs, especially long non-coding RNAs (lncRNAs) which are extensively reviewed in this article, their exact roles in tumorigenesis are-for the time being-not as evident as in the case of miRNAs, but, still, clearly suggested. Therefore, this review covers the non-coding RNA expression profile of bladder cancer patients and their validated target genes in bladder cancer cell lines, with repercussions on processes such as proliferation, invasiveness, apoptosis, cell cycle arrest, and other molecular pathways which are specific for the malignant transformation of cells.

Microarray based gene expression analysis of Sus Scrofa duodenum exposed to zearalenone: significance to human health.

BACKGROUND: Zearalenone (ZEA) is a secondary metabolite produced by Fusarium species. ZEA was proved to exert a wide range of unwanted side effects, but its mechanism of action, particularly at duodenum levels, remains unclear. In our study based on the microarray technology we assessed the alteration of gene expression pattern Sus scrofa duodenum which has been previously exposed to ZEA. Gene expression data was validated by qRT-PCR and ELISA. The gene expression data were further extrapolated the results to their human orthologues and analyzed the data in the context of human health using IPA (Ingenuity Pathways Analysis). RESULTS: Using Agilent microarray technology, we found that gene expression pattern was significantly affected by ZEA exposure, considering a 2-fold expression difference as a cut-off level and a p-value < 0.05. In total, we found 1576 upregulated and 2446 downregulated transcripts. About 1084 genes (764 downregulated and 751 overexpressed) were extrapolated to their human orthologues. IPA analysis showed various altered key cellular and molecular pathways. As expected, we observed a significant alteration of immune response related genes, MAPK (mitogen activate protein kinases) pathways or Toll-Like Receptors (TLRs). What captured our attention was the modulation of pathways related to the activation of early carcinogenesis. CONCLUSIONS: Our data demonstrate that ZEA has a complex effect at duodenum level. ZEA is able to activate not only the immune response related genes, but also those relate to colorectal carcinogenesis. The effects can be more dramatic when connected with the exposure to other environmental toxic agents or co-occurrence with different microorganisms.

Evaluation of cellular and molecular impact of zearalenone and Escherichia coli co-exposure on IPEC-1 cells using microarray technology.

BACKGROUND: The gastrointestinal tract is the primary site of toxin interaction, an interface between the organism and its surroundings. In this study, we assessed the alteration of intestinal mRNA profile in the case of co-occurrence of zearalenone (ZEA), a secondary Fusarium metabolite, and Escherichia coli (E. coli), on the intestinal porcine epithelial cells IPEC-1. We chose this model since the pig is a species which is susceptible to pathogen and mycotoxin co-exposure. RESULTS: After treating the cells with the two contaminants, either separately or in combination, the differential gene expression between groups was assessed, using the microarray technology. Data analysis identified 1691 upregulated and 797 downregulated genes as a response to E. coli exposure, while for ZEA treated cells, 303 genes were upregulated and 49 downregulated. The co-contamination led to 991 upregulated and 800 downregulated genes. The altered gene expression pattern was further classified into 8 functional groups. In the case of co-exposure to ZEA and E.coli, a clear increase of proinflammatory mechanisms. CONCLUSIONS: These results demonstrate the complex effect of single or multiple contaminants exposure at cellular and molecular level, with significant implications that might lead to the activation of pathological mechanisms. A better understanding of the effects of co-contamination is mandatory in developing novel exposure regulations and prevention measures.

Normalization of gene expression measurement of tissue samples obtained by transurethral resection of bladder tumors.

BACKGROUND: Sample processing is a crucial step for all types of genomic studies. A major challenge for researchers is to understand and predict how RNA quality affects the identification of transcriptional differences (by introducing either false-positive or false-negative errors). Nanotechnologies help improve the quality and quantity control for gene expression studies. PATIENTS AND METHODS: The study was performed on 14 tumor and matched normal pairs of tissue from patients with bladder urothelial carcinomas. We assessed the RNA quantity by using the NanoDrop spectrophotometer and the quality by nano-microfluidic capillary electrophoresis technology provided by Agilent 2100 Bioanalyzer. We evaluated the amplification status of three housekeeping genes and one small nuclear RNA gene using the ViiA 7 platform, with specific primers. RESULTS: Every step of the sample handling protocol, which begins with sample harvest and ends with the data analysis, is of utmost importance due to the fact that it is time consuming, labor intensive, and highly expensive. High temperature of the surgical procedure does not affect the small nucleic acid sequences in comparison with the mRNA. CONCLUSION: Gene expression is clearly affected by the RNA quality, but less affected in the case of small nuclear RNAs. We proved that the high-temperature, highly invasive transurethral resection of bladder tumor procedure damages the tissue and affects the integrity of the RNA from biological specimens.

MicroRNAs as regulators of apoptosis mechanisms in cancer.

MicroRNAs or miRNAs are small non-coding RNAs that regulate gene expression. Their discovery has brought new knowledge in biological processes of cancer. Involvement of miRNAs in cancer development includes several major pathways from cell transformation to tumor cell development, metastasis and resistance to treatment. The first part of this review discusses miRNAs function in the intrinsic and extrinsic pathways of apoptosis. Due to the fact that many miRNAs that regulate apoptosis have been shown to play a major role in tumor cell resistance to treatment, in the second part of the review we aim at discussing miRNAs potential in becoming curative molecules.

Exosome-Carried microRNA-375 Inhibits Cell Progression and Dissemination via Bcl-2 Blocking in Colon Cancer.

BACKGROUND AND AIMS: Worldwide, colorectal cancer (CRC) is the third most common cancer in men and second in women. The aim of the current study was to identify whether the miR-375 is indeed down-regulated in metastatic CRC and if it could be considered as a potential minimally invasive prognostic biomarker for CRC. METHODS: Exosomes were isolated and characterized from patients with liver metastasis from CCR. The characterization of exosome was performed using TEM/SEM. HCT116 cells were treated with miR-375 mimic, NSM and miR-375 inhibitor. Functional assays included cell counting assay for 14 days, Matrigel invasion assay, apoptosis assay by flow cytometry using Annexin V-FITC, RT-PCR and Western blotting. RESULTS: Increased proliferation potential was proven for the cells transfected with miR-375 inhibitor, while the miR-375 mimic decreased the cell number. The cells transfected with the miR-375 inhibitor are aggressive and cross the membrane; 3.84% of the cells transfected with the miR-375 inhibitor entered apoptosis, while 6.45% of those transfected with the non-specific mimic were in programmed cell death, less than those transfected with the microRNA. RT-PCR for Bcl-2 expression showed that Bcl-2 is down-regulated for miR-375 inhibitor and up-regulated for the miR-375 mimic, a result confirmed by Western blotting. CONCLUSION: The present study brings to the forefront new data that suggest miR-375 as a new player in controlling the pathways responsible for inhibiting the natural history of CRC tumor cells, via the Bcl-2 pathway.

Phytochemicals modulate carcinogenic signaling pathways in breast and hormone-related cancers.

Over the years, nutrition and environmental factors have been demonstrated to influence human health, specifically cancer. Owing to the fact that cancer is a leading cause of death worldwide, efforts are being made to elucidate molecular mechanisms that trigger or delay carcinogenesis. Phytochemicals, in particular, have been shown to modulate oncogenic processes through their antioxidant and anti-inflammatory activities and their ability to mimic the chemical structure and activity of hormones. These compounds can act not only by influencing oncogenic proteins, but also by modulating noncoding RNAs such as microRNAs and long noncoding RNAs. Although we are only beginning to understand the complete effects of many natural compounds, such as phytochemicals, researchers are motivated to combine these agents with traditional, chemo-based, or hormone-based therapies to fight against cancer. Since ongoing studies continue to prove effective, herein we exalt the importance of improving dietary choices as a chemo-preventive strategy.

Regulation of stem cells-related signaling pathways in response to doxorubicin treatment in Hs578T triple-negative breast cancer cells.

Different molecular changes have been previously associated with therapeutic response and recurrent disease, however, the detailed mechanism of action in triple-negative breast cancer subtype remains elusive. In this study, we investigated the cellular and molecular signaling of two claudin-low triple-negative breast cancer cells to doxorubicin and docetaxel treatment. Whole human transcriptomic evaluation was used to identify the subsequent changes in gene expression, while biological effects were measured by means of proliferation and anchorage-independent growth assays. Microarray analysis revealed changes in stem cell-related signaling pathways, suggesting that doxorubicin treatment affects the balance between self-renewal and differentiation. While the treatment reduced the proliferation, aggregation and mammosphere forming ability of stem-like cells derived from Hs578T cell line, stem-like cells derived from MDA-MB-231 cells were not significantly affected. Our results suggest that claudin-low triple-negative breast cancer cells might predominantly alter stem cell-related signaling pathways to promote stem-like cells activity as an innate resistance mechanism to doxorubicin treatment.

MicroRNAs in liver malignancies. Basic science applied in surgery.

Liver malignancies represent one of the major public health problems worldwide because of late diagnosis and failure of current treatments to offer a curative option for many of the patients. MicroRNAs (miRs) are small non-coding RNA molecules that are known to regulate the gene expression at a post-transcriptional level through complementary base pairing with thousands of messenger (m)RNAs. Recent data has shown the involvement of miRs in the pathogenesis of many human cancers, including those of the liver, with huge possible impact in the clinic, mainly due to the identification of non-coding RNAs as biomarkers that can often be detected in the systemic circulation. In the current review, we present the importance of miRs in liver cancers by discussing their role in the pathobiology of these diseases, apart from their role as diagnostic and prognostic markers for liver malignancies.

Clinical and pathological implications of miRNA in bladder cancer.

MicroRNAs (miRNAs) are small, noncoding RNA species with a length of 20-22 nucleotides that are recognized as essential regulators of relevant molecular mechanisms, including carcinogenesis. Current investigations show that miRNAs are detectable not only in different tissue types but also in a wide range of biological fluids, either free or trapped in circulating microvesicles. miRNAs were proven to be involved in cell communication, both in pathological and physiological processes. Evaluation of the global expression patterns of miRNAs provides key opportunities with important practical applications, taking into account that they modulate essential biological processes such as epithelial to mesenchymal transition, which is a mechanism relevant in bladder cancer. miRNAs collected from biological specimens can furnish valuable evidence with regard to bladder cancer oncogenesis, as they also have been linked to clinical outcomes in urothelial carcinoma. Therefore, a single miRNA or a signature of multiple miRNAs may improve risk stratification of patients and may supplement the histological diagnosis of urological tumors, particularly for bladder cancer.