Advances in molecular function of UPF1 in Cancer

It is known that more than 10 % of genetic diseases are caused by a mutation in protein-coding mRNA (premature termination codon; PTC). mRNAs with an early stop codon are degraded by the cellular surveillance process known as nonsense-mediated mRNA decay (NMD), which prevents the synthesis of C-terminally truncated proteins. Up-frameshift-1 (UPF1) has been reported to be involved in the downregulation of various cancers, and low expression of UPF1 was shown to correlate with poor prognosis. It is known that UPF1 is a master regulator of nonsense-mediated mRNA decay (NMD). UPF1 may also function as an E3 ligase and degrade target proteins without using mRNA decay mechanisms. Increasing evidence indicates that UPF1 could serve as a good biomarker for cancer diagnosis and treatment for future therapeutic applications. Long non-coding RNAs (lncRNAs) have the ability to bind different proteins and regulate gene expression; this role in cancer cells has already been identified by different studies. This article provides an overview of the aberrant expression of UPF1, its functional properties, and molecular processes during cancer for clinical applications in cancer. We also discussed the interactions of lncRNA with UPF1 for cell growth during tumorigenesis.

Redox Homeostasis and Nrf2-Regulated Mechanisms Are Relevant to Male Infertility

Infertility represents a significant global health challenge, affecting more than 12% of couples worldwide, and most cases of infertility are caused by male factors. Several pathological pathways are implicated in male infertility. The main mechanisms involved are driven by the loss of reduction-oxidation (redox) homeostasis and the resulting oxidative damage as well as the chronic inflammatory process. Increased or severe oxidative stress leads to sperm plasma membrane and DNA oxidative damage, dysregulated RNA processing, and telomere destruction. The signaling pathways of these molecular events are also regulated by Nuclear factor-E2-related factor 2 (Nrf2). The causes of male infertility, the role of oxidative stress in male infertility and the Keap1-Nrf2 antioxidant pathway are reviewed. This review highlights the regulatory role of Nrf2 in the balance between oxidants and antioxidants as relevant mechanisms to male fertility. Nrf2 is involved in the regulation of spermatogenesis and sperm quality. Establishing a link between Nrf2 signaling pathways and the regulation of male fertility provides the basis for molecular modulation of inflammatory processes, reactive oxygen species generation, and the antioxidant molecular network, including the Nrf2-regulated antioxidant response, to improve male reproductive outcomes.

Proteomics analysis identifies the ribosome associated coiled-coil domain-containing protein-124 as a novel interaction partner of nucleophosmin-1

BACKGROUND INFORMATION

Coiled-coil domain-containing protein-124 (Ccdc124) is a conserved eukaryotic ribosome-associated RNA-binding protein which is involved in resuming ribosome activity after stress-related translational shutdown. Ccdc124 protein is also detected at cellular localizations devoid of ribosomes, such as the centrosome, or the cytokinetic midbody, but its translation-independent cellular function is currently unknown.

RESULTS

By using an unbiased LC-MS/MS-based proteomics approach in human embryonic kidney (HEK293) cells, we identified novel Ccdc124 partners and mapped the cellular organization of interacting proteins, a subset of which are known to be involved in nucleoli biogenesis and function. We then identified a novel interaction between the cancer-associated multifunctional nucleolar marker nucleophosmin (Npm1) and Ccdc124, and we characterized this interaction both in HEK293 (human embryonic kidney) and U2OS (osteosarcoma) cells. As expected, in both types of cells, Npm1 and Ccdc124 proteins colocalized within the nucleolus when assayed by immunocytochemical methods, or by monitoring the localization of green fluorescent protein-tagged Ccdc124.

CONCLUSIONS

The nucleolar localization of Ccdc124 was impaired when Npm1 translocates from the nucleolus to the nucleoplasm in response to treatment with the DNA-intercalator and Topo2 inhibitor chemotherapeutic drug doxorubicin. Npm1 is critically involved in maintaining genomic stability by mediating various DNA-repair pathways, and over-expression of Npm1 or specific NPM1 mutations have been previously associated with proliferative diseases, such as acute myelogenous leukemia, anaplastic large-cell lymphoma, and solid cancers originating from different tissues.

SIGNIFICANCE

Identification of Ccdc124 as a novel interaction partner of Nmp1 within the frame of molecular mechanisms involving nucleolar stress-sensing and DNA-damage response is expected to provide novel insights into the biology of cancers associated with aberrations in NPM1.

An intricate rewiring of cancer metabolism via alternative splicing

All human genes undergo alternative splicing leading to the diversity of the proteins. However, in some cases, abnormal regulation of alternative splicing can result in diseases that trigger defects in metabolism, reduced apoptosis, increased proliferation, and progression in almost all tumor types. Metabolic dysregulations and immune dysfunctions are crucial factors in cancer. In this respect, alternative splicing in tumors could be a potential target for therapeutic cancer strategies. Dysregulation of alternative splicing during mRNA maturation promotes carcinogenesis and drug resistance in many cancer types. Alternative splicing (changing the target mRNA 3'UTR binding site) can result in a protein with altered drug affinity, ultimately leading to drug resistance.. Here, we will highlight the function of various alternative splicing factors, how it regulates the reprogramming of cancer cell metabolism, and their contribution to tumor initiation and proliferation. Also, we will discuss emerging therapeutics for treating tumors via abnormal alternative splicing. Finally, we will discuss the challenges associated with these therapeutic strategies for clinical applications.

Identification of differentially expressed miRNAs and mRNAs associated with the regulation of breast cancer via in silico and in vitro methods

miRNA expressions are altered during development of breast cancer (BC). The aim of this study is to identify novel cancer-related miRNAs and pathways to understand the mechanisms of BC subtypes. GSE59247 dataset was downloaded from gene expression omnibus (GEO) database and analyzed with GEO2R software. The differential miRNA expressions in BC cells were evaluated by miRNome PCR array. Venn diagram was used to reveal co-differentially expressed miRNAs between GSE59247 dataset and miRNome array. Clinical prognostic significance of selected miRNAs was evaluated via Kaplan Meier curve. KEGG pathway enrichment analysis was performed to find miRNA targets and results were validated by TNM plot analysis and q-RT-PCR. TargetScan database was used to predict the association of miRNAs and 3'-untranslated regions of target genes and their expressions were visualized by human protein atlas database. Venn diagram analysis showed overlap of 11 miRNAs from in silico and in vitro analysis. KEGG analysis revealed 'Lysine Degradation Pathway' as the most significantly enriched targeted pathway. q-RT-PCR results confirmed that Lysine degradation pathway related genes SETD7, SETDB2, EHHADH, SETMAR, KMT2A and SUV39H2 were differentially expressed in BC cells. Target prediction analysis identified binding sites between miR-1323-5p and 3'-UTR of SETD7, miR-129-5p and 3'-UTR of EHHADH and miR-628-5p and 3'-UTR of SETDB2 mRNA. Notably, miR-1323-5p, miR-129-5p, and miR-628-5p are differentially expressed in BC and they bind to 3'UTR of critical genes of Lysine degradation pathway, namely SETD7, SETDB2 and EHHADH. These miRNAs might serve as potential diagnostic and prognostic biomarkers for progression.

Clitocybe nebularis extract and 5‑fluorouracil synergistically inhibit the growth of HT-29 colorectal cancer cells by inducing the S phase arrest

Although 5-fluorouracil (5-FU) is an important anticancer agent for the treatment of colorectal cancer, drug resistance, and dose-related side effects limit the effectiveness of the treatment. Therefore, developing new pharmaceuticals with effective and low toxicity is critically necessary for cancer therapy. This study aimed to investigate the cytotoxic activity of the Clitocybe nebularis mushroom extract (CN) on HT-29 human colon cancer cells. A series of in vitro experiments were performed on the HT-29, Caco-2, and HEK-293 cells, which includes cytotoxicity, drug interaction, colony formation, cell cycle, and migration assays. In addition, qRT-PCR experiment was also performed to investigate the potential molecular mechanisms of action of CN on the proliferation of colon cancer cell line. Our results show that CN exhibited selective cytotoxic activity on HT-29 and Caco-2 colon cancer cells, whereas no cytotoxic effect was observed on normal HEK-293 cells. With the combination of CN and 5‑FU, their cytotoxic activity on HT-29 cells was significantly increased compared to their use alone. In addition, the combination of CN and 5-FU also showed synergistic anticancer activity through cell cycle arrest in the S phase. The results also show that p21, p27, and p53 expression levels increased as a result of CN treatment. Our in vitro findings show that CN has a synergistic effect with 5-FU by inhibiting cell proliferation of colon cancer cells and inducing cell cycle arrest in the S phase.

Interplay between Non-Coding RNAs and NRF2 in Different Cancers: Spotlight on MicroRNAs and Long Non-Coding RNAs

Cancer is a multifactorial disease, and a wealth of information has enabled basic and clinical researchers to develop a better conceptual knowledge of the highly heterogeneous nature of cancer. Deregulations of spatio-temporally controlled transduction pathways play a central role in cancer progression. NRF2-driven signaling has engrossed significant attention because of its fundamentally unique features to dualistically regulate cancer progression. Context-dependent diametrically opposed roles of NRF2-induced signaling are exciting. More importantly, non-coding RNA (ncRNA) mediated regulation of NRF2 and interplay between NRF2 and ncRNAs have added new layers of complexity to already intricate nature of NRF2 signaling. There is a gradual enrichment in the existing pool of knowledge related to interplay between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in different cancers. However, surprisingly, there are no clues about interplay between circular RNAs and NRF2 in various cancers. Therefore, future studies must converge on the functional characterization of additional important lncRNAs and circular RNAs, which regulated NRF2-driven signaling or, conversely, NRF2 transcriptionally controlled their expression to regulate various stages of cancer. SIGNIFICANCE STATEMENT: Recently, many researchers have focused on the NRF2-driven signaling in cancer progression. Excitingly, discovery of non-coding RNAs has added new layers of intricacy to the already complicated nature of KEAP1/NRF2 signaling in different cancers. These interactions are shaping the NRF2-driven signaling landscape, and better knowledge of these pathways will be advantageous in pharmacological modulation of non-coding RNA-mediated NRF2 signaling in various cancers.

NRF2, a crucial modulator of skin cells protection against vitiligo, psoriasis, and cancer

The skin represents a physical barrier between the organism and the environment that has evolved to confer protection against biological, chemical, and physical insults. The inner layer, known as dermis, is constituted by connective tissue and different types of immune cells whereas the outer layer, the epidermis, is composed by different layers of keratinocytes and an abundant number of melanocytes, localized in the stratum basale of the epidermis. Oxidative stress is a common alteration of inflammatory skin disorders such as vitiligo, dermatitis, or psoriasis but can also play a causal role in skin carcinogenesis and tumor progression. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) has emerged as a crucial regulator of cell defense mechanisms activating complex transcriptional programs that facilitate reactive oxygen species detoxification, repair oxidative damage and prevent xenobiotic-induced toxicity. Accumulating evidence suggests that the keratinocytes, melanocytes, and other skin cell types express high levels of NRF2, which is known to play a pivotal role in the skin homeostasis, differentiation, and metabolism during normal and pathologic conditions. In the present review, we summarize the current evidence linking NRF2 to skin pathophysiology and we discuss some recent modulators of NRF2 activity that have shown a therapeutic efficacy in skin protection against tumor initiation and common inflammatory skin conditions such as vitiligo or psoriasis, with a particular emphasis on natural compounds.

cAMP/PKA-CREB-BDNF signaling pathway in hippocampus of rats subjected to chemically-induced phenylketonuria

Phenylketonuria (PKU) is an inborn error disease in phenylalanine metabolism resulting from defects in the stages of converting phenylalanine to tyrosine. Although the pathophysiology of PKU is not elucidated yet, the toxic effect of phenylalanine on the brain causes severe mental retardation. In relation to learning and memory, the hippocampal PKA / CREB / BDNF pathway may play a role in learning deficits in PKU patients. This study aimed to investigate PKA/CREB/BDNF pathway in hippocampus of chemically induced PKU rats with regard to gender. Sprague-Dawley rat pups were randomized into two groups of both genders. To chemically induce PKU, animals received subcutaneous administration of phenylalanine (5.2 mmol / g) plus p-chlorophenylalanine, phenylalanine hydroxylase inhibitor (0.9 mmol / g); control animals received 0.9% NaCl. Injections started on the 6th day and continued until the 21st day after which locomotor activity, learning and memory were tested. In male PKU rats, locomotor activity was reduced. There were no differences in learning and memory performances of male and female PKU rats. In PKU rats, pCREB / CREB levels in males was unchanged while it decreased in females. Elevated PKA activity, BDNF levels and decreased pCREB/CREB ratio found in female PKU rats were not replicated in PKU males in which BDNF is decreased. Our results display that in this disease model a gender specific differential activation of cAMP/PKA-CREB-BDNF signaling pathway in hippocampus occurs investigation of which can help us to a better understanding of disease pathophysiology.

Expression patterns of miR-34a, miR-125b, miR-221 and antioxidant gene NRF2 in plasma samples of patients with atherosclerosis

Atherosclerosis is one of the main reasons of cardiovascular diseases, the most common cause of death in the world. NRF2 is a critical transcriptional factor that regulates oxidative stress response and contributes to the pathogenesis of atherosclerosis. This study aims to compare the expression levels of miR-34a, miR-125b, miR- 221 and NRF2 in blood samples of patients with atherosclerosis and of controls to find a novel link between microRNAs, oxidative stress and atherosclerosis. miR-34a, miR-125b, miR-221 and NRF2 relative expressions were analysed in 26 atherosclerosis patients and 25 healthy controls by q-RT-PCR assay. The receiver operating characteristic curve (ROC) was used to assess the diagnostic values of miR-34a, miR-125b, miR-221 and NRF2 by comparing the area under the curves (AUC) to differentiate between atherosclerosis and control samples. miR-34a and NRF2 were significantly upregulated, whereas miR-125b and miR-221 were significantly downregulated in patients compared with healthy controls. The ROC curves suggested high diagnostic value of miR-221 (AUC: 0.7477), miR-125b (AUC: 0.8523) and NRF2 (AUC: 0.838) for detection of atherosclerosis. Our results suggest that circulating miR-34a, miR-125b and miR-221 levels can be used as novel biomarkers for detection of atherosclerosis by targeting NRF2.

The Applications of Next-generation Sequencing (NGS) in Drug Development for Cancer Therapy

Background:

Numerous sequencing techniques have been progressed since the 1960s with the rapid development of molecular biology studies focusing on DNA and RNA.

Methods:

A great number of articles, book chapters, websites are reviewed, and the studies covering NGS history, technology and applications to cancer therapy are included in the present article.

Results:

High throughput next-generation sequencing (NGS) technologies offer many advantages over classical Sanger sequencing with decreasing cost per base and increasing sequencing efficiency. NGS technologies are combined with bioinformatics software to sequence genomes to be used in diagnostics, transcriptomics, epidemiologic and clinical trials in biomedical sciences. NGS technology has also been successfully used in drug discovery for the treatment of different cancers.

Conclusion:

This review focuses on current and potential applications of NGS in various stages of drug discovery process, from target identification through to personalized medicine.

Identification of miR-17, miR-21, miR-27a, miR-106b and miR-222 as endoplasmic reticulum stress-related potential biomarkers in circulation of patients with atherosclerosis

Atherosclerosis and related cardiovascular diseases are among the most common causes of death worldwide. Unfolded protein response, also known as Endoplasmic reticulum stress, has a critical role in many diseases including atherosclerosis. Small non-coding microRNAs (miRNA), which generally suppress gene expression, regulate UPR signalling and they may also be involved in the progression of atherosclerosis. We aim to investigate the expression levels of miR-17, miR-21, miR-27a, miR-106b, miR-222 and CHOP gene in circulation of atherosclerosis patients compared to healthy controls to establish a link between ER stress and atherosclerosis. miRNA containing whole RNA was isolated from blood samples of 25 patients with atherosclerosis and 26 healthy controls. Expression levels of miRNAs and CHOP were measured via Real Time PCR method. miR-17 and miR-106b were significantly increased while miR-21, miR-27a, and miR-222 were significantly decreased in patients compared to controls. CHOP gene was also dramatically and significantly induced in patient samples. miR-17, miR-21, miR-27a, miR-106b, miR-222 and CHOP were significantly differentially expressed in patients with atherosclerosis. Each miRNA and CHOP might regulate atherosclerotic plaque progression and they can be used as a biomarker in the diagnosis and follow-up of atherosclerosis-related cardiovascular diseases.

Therapeutic Targeting of the NRF2 Signaling Pathway in Cancer

Cancer is one of the most fatal diseases with an increasing incidence and mortality all over the world. Thus, there is an urgent need for novel therapies targeting major cancer-related pathways. Nuclear factor-erythroid 2-related factor 2 (NRF2) and its major negative modulator Kelch-like ECH-associated protein 1 (KEAP1) are main players of the cellular defense mechanisms against internal and external cell stressors. However, NRF2/KEAP1 signaling pathway is dysregulated in various cancers, thus promoting tumor cell survival and metastasis. In the present review, we discuss the mechanisms of normal and deregulated NRF2 signaling pathway focusing on its cancer-related functions. We further explore activators and inhibitors of this pathway as cancer targeting drug candidates in order to provide an extensive background on the subject.

The NRF2/KEAP1 Axis in the Regulation of Tumor Metabolism: Mechanisms and Therapeutic Perspectives

The NRF2/KEAP1 pathway is a fundamental signaling cascade that controls multiple cytoprotective responses through the induction of a complex transcriptional program that ultimately renders cancer cells resistant to oxidative, metabolic and therapeutic stress. Interestingly, accumulating evidence in recent years has indicated that metabolic reprogramming is closely interrelated with the regulation of redox homeostasis, suggesting that the disruption of NRF2 signaling might represent a valid therapeutic strategy against a variety of solid and hematologic cancers. These aspects will be the focus of the present review.

Pharmacological Applications of Nrf2 Inhibitors as Potential Antineoplastic Drugs

Oxidative stress (OS) is associated with many diseases ranging from cancer to neurodegenerative disorders. Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) is one of the most effective cytoprotective controller against OS. Modulation of Nrf2 pathway constitutes a remarkable strategy in the antineoplastic treatments. A big number of Nrf2-antioxidant response element activators have been screened for use as chemo-preventive drugs in OS associated diseases like cancer even though activation of Nrf2 happens in a variety of cancers. Research proved that hyperactivation of the Nrf2 pathway produces a situation that helps the survival of normal as well as malignant cells, protecting them against OS, anticancer drugs, and radiotherapy. In this review, the modulation of the Nrf2 pathway, anticancer activity and challenges associated with the development of an Nrf2-based anti-cancer treatment approaches are discussed.