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Aim Survivin, an inhibitor of apoptosis protein, is overexpressed in most cancers and is associated with chemotherapy resistance, increased tumor recurrence and shorter patient survival. Several survivin splice variants have been described, and none of their expressions have been defined in acute promyelocytic leukemia (APL). Methods Expression of the survivin gene isoforms (survivin, -2α, -2B, -ΔΕx3 and -3B) were analyzed in 50 peripheral blood and 19 bone marrow samples that were collected at different phases of the disease (diagnostic, remission and relapse) in APL patients treated with arsenic trioxide (ATO) as a front-line therapy. In addition, the human APL-derived cell line (NB4) was analyzed for the expression of survivin isoforms and capsase-3 in response to the ATO. Results Survivin and its variants were overexpressed significantly in patient's bone marrow samples compared to peripheral blood or normal samples. Their expression was decreased after ATO treatment in both NB4 cells (except survivin-2α) and APL patients along with PML-RARα copy number reduction. Downregulation of survivin isoforms was associated with an increase in both caspase-3 gene expression and its enzymatic activity levels. In a patient who did not respond to ATO treatment, expression of survivin isoforms (except survivin-2α) were highly increased during the induction therapy. Conclusion Survivin isoforms are upregulated in APL patients, and their expression is diminished during the ATO treatment. In addition, overexpression of survivin and its variants (except survivin-2α) are associated with unfavorable results, suggesting that they may play an important role in mechanisms underlying the resistance of APL cells to ATO. [ABSTRACT FROM AUTHOR]

Background: Acute myeloid leukemia (AML) is an immunophenotypically heterogeneous malignant disease, in which CD34 positivity is associated with poor prognosis. Osteopontin (OPN) plays different roles in physiologic and pathologic conditions like: survival, metastasis and cell protection from cytotoxic and apoptotic stimuli. Due to anti-apoptotic effect of OPN in normal and malignant cells, silencing of OPN leads to elevation of sensitivity towards chemotherapeutic agents and attenuates cancer cells migration and invasion. Therefore, the aim of this study was to evaluate OPN roles in modulating curcumin-mediated growth inhibitory on leukemic stem cells (LSCs) colony forming potential and survival in AML cell lines and primary CD34+/CD38- bone marrow-derived AML cells. Materials and Methods: Primary human CD34+/CD38- cells were isolated from bone marrow mononuclear cells of 10 AML patients at initial state of diagnosis, using a CD34 Multi sort kit. The growth inhibitory effects of curcumin (CUR) were evaluated by MTT and colony-formation assays. Apoptosis was analyzed by 7AAD assay in CD34+ KG-1, U937 cell lines and primary isolated cells. Short interfering RNA (siRNA) against OPN was used for OPN silencing in both cell lines and primary AML cells. Then, transfected cells were incubated with/without curcumin. The change in OPN gene expression was examined by Real-time PCR. Results: CUR inhibited proliferation and induced apoptosis in both KG-1 and U937 cells and also primary isolated AML cells. OPN silencing by siRNA increased the susceptibility of KG-1, U937 and primary CD34+/CD38- AML cells to apoptosis. Moreover, soft agar colony assays revealed that silencing of OPN with siRNA significantly decreased colony numbers in LSCs compared with the non-targeting group. Furthermore, CD34+/CD38- populations as a main LSCs compartment through OPN overexpression towards CUR treatment might be nullified the inhibitory effects of OPN siRNA on their survival and colony forming potential. Conclusion: Taken together, our results suggested that knockdown of OPN using OPN specific siRNA significantly decreased colony numbers in LSCs and this effect might be vetoed by LSCs via induction of OPN overexpressionin combination of CUR and siRNA. [ABSTRACT FROM AUTHOR]

Aims Acute myeloid leukemia (AML) initiation and progression have been attributed to subpopulations of self-renewing leukemia stem cells (LSCs), which contribute to progression, recurrence and therapeutic resistance in leukemia. Osteopontin (OPN) plays an important role in promoting survival and drug resistance in LSCs. The aim of this study was to explore OPN roles in modulating curcumin-mediated LSC enrichment and survival in AML cell lines and primary CD34 +/CD38 − bone-marrow-derived AML cells. Materials and methods The growth inhibitory effects of curcumin (CUR) were evaluated by MTT assay in U937 and CD34 + KG-1 AML cell lines as well as primary CD34 +/CD38 − bone-marrow derived AML cells isolated by MACS technique. The proportion of LSC markers (CD34, CD38 and CD123) were evaluated by flow cytometry. The expression levels of OPN, AKT, mTOR, PTEN, β-catenin and NF-κB were investigated by qRT-PCR. Short interfering RNA (siRNA) against OPN was used in AML cells incubated with or without CUR. Key findings Proportions of CD34 +/CD38 −/CD123 + and CD34 +/CD38 +/CD123 + LSCs compartment co-expressing an increased level of OPN could be enriched in AML cell lines and in patient's primary cells by CUR treatment. The expression levels of AKT, mTOR, PTEN, and β-catenin and NF-κB1, were also significantly up-regulated concurrently with OPN in the enriched CD34 + AML cells. Significance The increased in CUR-mediated OPN level is involved in a complex interplay of various signaling pathways resulting in cytoprotection and enrichment of CD34 + LSC compartment in CUR-treated AML cells. AKT/mTOR/PTEN/β-catenin/NF-kB signaling pathways may play roles in modulating OPN-mediated LSC cell survival and enrichment. [ABSTRACT FROM AUTHOR]

Metformin has recently been introduced as an anti-cancer agent. In this study, we evaluated the effect of metformin and metformin/cisplatin on human gastric MKN-45 cell line. When we used metformin alone, it could inhibit proliferation and induce apoptosis, but it diminish anti-proliferative effects of cisplatin when they are used in combination. Further, we checked mRNA levels of survivin, mTOR, and Akt by real-time PCR. When MKN-45 cells were treated with metformin/cisplatin, the expression of survivin and mTOR were increased. The antagonistic effect of metformin on cisplatin could be through survivin and mTOR signaling pathways. Our results also suggest that interfering effect of metformin on cisplatin may be also through upregulation of Akt. Regarding the pivotal role of Akt in drug resistance, it may be reasonable to conclude that the antagonistic effect of metformin on cisplatin effect may be through this central mediator of drug resistance. Taken together, it seems that metformin is not a good option for sensitizing MKN-45 cell line to cisplatin, and in co-prescription of metformin and cisplatin in gastric cancer patients who suffer diabetes type 2, it should be highly cared. [ABSTRACT FROM AUTHOR]

Background: Silibinin is a traditionally well-known drug for its hepatoprotective efficacy against various types of liver afflictions. In addition, it has recently been considered broadly as a potential chemopreventive agent against many types of cancers. The current study was designed to evaluate the restrictive effects of pharmacological doses of silibinin on SKBR3, an ErbB2-overexpressed and ER-negative human breast carcinoma cell line. Methods: Effect of silibinin on metabolic activity and proliferation of human breast carcinoma (SKBR3) cell line were evaluated by MTT and BrdU assays respectively. Furthermore, the proapoptotic effect of silibinin was investigated using flow cytometry. The NF-κB phosphorylation assay was also used to assess the effect of silibinin on NF-κB activation. The alkalizing effect of silibinin on SKBR3 cell line was evaluated by measuring pH of media of the silibinin-treated cells compared to control. Results: Our results indicate that silibinin inhibited metabolic activity and cell proliferation of SKBR3 cells in a dose-dependent manner. Moreover, silibinin significantly induced apoptosis in SKBR3 cells. On the other hand, silibinin significantly inhibited activation of NF-κB which is known to be highly active in this cell line. Alkalizing effect of silibinin was also observed. Conclusion: The results obtained here indicate that silibinin may be an efficacious therapeutic agent against ER-negative breast carcinomas with high inhibitory effect on NF-κB. [ABSTRACT FROM AUTHOR]

Background: Silibinin is a traditionally well-known drug for its hepatoprotective efficacy against various types of liver afflictions. In addition, it has recently been considered broadly as a potential chemopreventive agent against many types of cancers. The current study was designed to evaluate the restrictive effects of pharmacological doses of silibinin on SKBR3, an ErbB2-overexpressed and ER-negative human breast carcinoma cell line. Methods: Effect of silibinin on metabolic activity and proliferation of human breast carcinoma (SKBR3) cell line were evaluated by MTT and BrdU assays respectively. Furthermore, the proapoptotic effect of silibinin was investigated using flow cytometry. The NF-κB phosphorylation assay was also used to assess the effect of silibinin on NF-κB activation. The alkalizing effect of silibinin on SKBR3 cell line was evaluated by measuring pH of media of the silibinin-treated cells compared to control. Results: Our results indicate that silibinin inhibited metabolic activity and cell proliferation of SKBR3 cells in a dose-dependent manner. Moreover, silibinin significantly induced apoptosis in SKBR3 cells. On the other hand, silibinin significantly inhibited activation of NF-κB which is known to be highly active in this cell line. Alkalizing effect of silibinin was also observed. Conclusion: The results obtained here indicate that silibinin may be an efficacious therapeutic agent against ER-negative breast carcinomas with high inhibitory effect on NF-κB. [ABSTRACT FROM AUTHOR]

Highlights: [•] ATO treatment decreases proliferation of neuroblastoma SK-N-BE(2) and SK-N-MC cells. [•] Inhibition of PI3K or MAPK sensitizes NB cells to low doses of ATO. [•] Inhibition of PI3K and MAPK act synergistically with ATO in I-type NB cells. [•] Different subtypes of NB require different treatments. [ABSTRACT FROM AUTHOR]

Highlights: [•] hGH producing breast cancer cell line did not have inhibitory effect against the cytotoxicity of ATO. [•] Autocrine hGH increase sensitivity of mammary carcinoma cell to ATO-induced apoptosis. [•] ATO counteracts with hGH at transcriptional levels of genes involved in survival. [•] c-Myc may be an important common target of both hGH and ATO. [•] ATO treatment may be beneficial for treatment of patients with hGH positive tumors. [Copyright &y& Elsevier]

Since unlimited proliferative potential has been identified as a major and, to date, therapeutically unexploited phenotypic hallmark of cancer, telomere maintenance mechanisms have been proposed as potential targets for new anticancer interventions. This study was aimed to investigate the effects of BIBR1532, the lead compound of non-nucleosidic inhibition of telomerase, on pre-B acute lymphoblastic leukemia (ALL) cells. BIBR1532 caused rapid cell death in Nalm-6 cells probably through transcriptional suppression of survivin-mediated c-Myc and human telomerase reverse transcriptase (hTERT) expression in a concentration-dependent manner. Moreover, our results also suggest that induced p73, up-regulated Bax/Bcl-2 molecular ratio and subsequent activation of caspase-3 may contribute to a direct short-term cytotoxic effect of high doses of BIBR1532, independent of long-term substantial telomere erosion-mediated cell cycle arrest. [ABSTRACT FROM AUTHOR]

Acute promyelocytic leukemia (APL) is characterized by specific t(15;17), distinct morphologic picture, and clinical coagulopathy that contributes to the morbidity and mortality of the disease. This study was purposed to dissect the molecular mechanisms underlying telomerase-dependent arsenic trioxide (ATO)-induced cytotoxic and anti-proliferative effects in NB4 cells. ATO exposure was associated with transcriptional repression of Pin1, survivin, c-Myc, hTERT, and PinX1 along with an expressive enhancement in p73 mRNA level. Moreover, ATO treatment suppressed cell growth, viability and metabolic activity, exerted apoptosis, hindered telomerase activity, shortened telomere length, and dampened NF-κB activation. On aggregate, these issues indicate that ATO might preempt cell growth and proliferation in NB4 cells through suppression of Pin1-mediated NF-κB-dependent stimulation of telomerase and survivin. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are essential mediators of crucial cellular processes including apoptosis, proliferation, survival and cell cycle. Their regulatory role in cancer progression has seen in different human malignancies such as acute myeloid leukemia (AML). AML patients suffer from high resistance of the tumors against routine therapeutics including ATO. ATO enhance reactive oxygen species levels and induce apoptosis and suppresses proliferation in AML cells. However, some pathways such as JAK2/STAT3 ease anti-tumor activity of ATO by reducing reactive oxygen species amount and protecting the cell from apoptosis. In the present study, we use ruxolitinib (potent JAK2 inhibitor) to increase the sensitivity of AML cells to ATO treatment. We test, the effect of this combination on metabolic activity, proliferation, colony formation, cell cycle distribution, apoptosis, oxidative stress and DNA damage. Our results showed that combination of ATO with ruxolitinib synergistically reduced metabolic activity, proliferation and survival of AML cell lines. This combination induced G1/S cell cycle arrest because of reactive oxygen species elevation and GSH reduction. Besides, enhancement of reactive oxygen species increased apoptosis rate in combination samples. We uncovered that the synergistic anti-tumor effect of ATO and ruxolitinib in AML cells mediates via reactive oxygen species elevation and DNA damage. Overall, our results show that the combinatorial therapy of AML cells is more effective than solo-targeted therapy. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNAs) are a diverse class of RNAs whose functions are widespread in all branches of life and have been the focus of attention in the last decade. While a huge number of lncRNAs have been identified, there is still much work to be done and plenty to be learned. In the current review, we begin with the biogenesis and function of lncRNAs as they are involved in the different cellular processes from regulating the architecture of chromosomes to controlling translation and post‐translation modifications. Questions on how overexpression, mutations, or deficiency of lncRNAs can affect the cellular status and result in the pathogenesis of various human diseases are responded to. Besides, we allocate an overview of several studies, concerning the application of lncRNAs either as diagnostic and prognostic biomarkers or novel therapeutics. We also introduce the currently available techniques to explore details of lncRNAs such as their function, cellular localization, and structure. In the last section, as exponentially growing data in this area need to be gathered and organized in comprehensive databases, we have a particular focus on presenting general and specialized databases. Taken together, with this review, we aim to provide the latest information on different aspects of lncRNAs to highlight their importance in physiopathologic states and take a step towards helping future studies. Significance statement: This study aims to review the roles of long noncoding RNAs in the pathogenesis of diseases and introduce them as potential candidates for diagnostic biomarkers and therapeutic targets. However, there are a significant number of lncRNAs whose molecular mechanisms and functions are poorly understood; illustrating the importance of bioinformatics tools and databases to predict and analyze the structure, function, and other features of these molecules. In addition, developing high‐throughput techniques has accelerated the process of lncRNA research. Thus, we reviewed the bioinformatic tools and different techniques to explore diverse aspects of lncRNAs, hoping this information will be a beacon of light for future studies. [ABSTRACT FROM AUTHOR]

DNA methylation is critical for the normal development and functioning of the human brain, such as the proliferation and differentiation of neural stem cells, synaptic plasticity, neuronal reparation, learning, and memory. Despite the physical stability of DNA and methylated DNA compared to other epigenetic modifications, some DNA methylation-based biomarkers have translated into clinical practice. Increasing reports indicate a strong association between DNA methylation profiles and various clinical outcomes in neurological diseases, making DNA methylation profiles valuable as novel clinical markers. In this review, we aim to discuss the latest evidence concerning DNA methylation alterations in the development of neurodegenerative, neurodevelopmental, and neuropsychiatric diseases. We also highlighted the relationship of DNA methylation alterations with the disease progression and outcome in many neurological diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and autism. [ABSTRACT FROM AUTHOR]

• The present study reviews macrophage phagocytosis regulation in response to tumors. • This review outlines recent advances of modulating macrophage phagocytosis in cancers. • We concentrate on the emerging role of CAR-engineered macrophages against solid tumors. • We reviewed the exploit of nanoparticles in macrophages-mediated anticancer effects. Immunotherapy has been developing at an unprecedented speed with promising therapeutic outcomes in the wide spectrum of cancers. Up until now, most immunotherapies have focused on adaptive immunity; however, investigating the potential of macrophage phagocytosis and consequent adaptive immune cross-priming has led to a growing interest in exploiting macrophages in cancer therapy. In light of the positive evidence from preclinical studies and early clinical data, targeting macrophage phagocytosis has become a promising therapeutic strategy. Here, we review therapies based on harnessing and amplifying macrophage phagocytosis, such as blocking phagocytosis checkpoints and exploiting nanoparticles as efficient approaches in elevating macrophages-mediated phagocytosis. The present study introduces CAR-macrophage as the state-of-the-art modality serving as the bridge between the innate and adaptive immune system to mount a superior anti-tumor response in the treatment of cancer. We also take a look at the recent reports of therapies based on CAR-engineered macrophages with the hope of providing a future research direction for expanding the application of CAR-macrophage therapy. [ABSTRACT FROM AUTHOR]

Despite remarkable advances in different types of cancer therapies, an effective therapeutic strategy is still a major and significant challenge. One of the most promising approaches in this regard is immunotherapy, which takes advantage of the patients' immune system; however, the many mechanisms that cancerous cells harbor to extend their survival make it impossible to gain perfect eradication of tumors. The response rate to cancer immunotherapies, especially checkpoint inhibitors and adoptive T cell therapy, substantially differs in various cancer types with the highest rates in advanced melanoma and non‐small cell lung cancer. Indeed, the lack of response in many tumors indicates primary resistance that can originate from either tumor cells (intrinsic) or tumor microenvironment (extrinsic). On the other hand, some tumors show an initial response to immunotherapy followed by relapse in few months (acquired resistance). Understanding the underlying molecular mechanisms of immunotherapy resistance makes it possible to develop effective strategies to overcome this hurdle and boost therapy outcomes. In this review, we take a look at immunotherapy strategies and go through a number of primary and acquired resistance mechanisms. Also, we present various ongoing methods to overcoming resistance and introduce some promising fields to improve the outcome of immunotherapy in patients affected with cancer. [ABSTRACT FROM AUTHOR]

Purpose: Therapy resistance is the principal obstacle to achieving cures in cancer patients and its successful tackling requires a deep understanding of the resistance mediators. Increasing evidence indicates that tumor phosphatases are novel and druggable targets in translational oncology and their modulation may hinder tumor growth and motility and potentiate therapeutic sensitivity in various neoplasms via regulation of various signal transduction pathways. Dual-specificity phosphatases (DUSPs) are key players of cell growth, survival and death and have essential roles in tumor initiation, malignant progression and therapy resistance through regulation of the MAPK signaling pathway. In this review, different aspects of DUSPs are discussed. Methods: A comprehensive literature review was performed using various websites including PubMed. Results: We provide mechanistic insights into the roles of well-known DUSPs in resistance to a wide range of cancer therapeutic approaches including chemotherapy, radiation and molecular targeted therapy in human malignancies. Moreover, we discuss the development of DUSP modulators, with a focus on DUSP1 and 6 inhibitors. Ultimately, the preclinical investigations of small molecule inhibitors of DUSP1 and 6 are outlined. Conclusion: Emerging evidence indicates that the DUSP family is aberrantly expressed in human malignancies and plays critical roles in determining sensitivity to a wide range of cancer therapeutic strategies through regulation of the MAPK signaling pathways. Consequently, targeting DUSPs and their downstream molecules can pave the way for more effective cancer therapies. [ABSTRACT FROM AUTHOR]

Background: In the new era of tailored cancer treatment strategies, finding a molecule to regulate a wide range of intracellular functions is valuable. The unique property of nuclear receptor peroxisome proliferator‐activated receptor‐γ (PPARγ; PPARG) in transmitting the anti‐survival signals of the chemotherapeutic drugs has fired the enthusiasm into the application of this receptor in cancer treatment. Objectives: We aimed to investigate the expression of PPARγ and one of its downstream targets PTEN in non‐M3 acute myeloid leukemia (AML) patients. We also investigated the therapeutic value of PPARγ stimulation using pioglitazone in the AML‐derived U937 cell line. Methods: The blood samples from 30 patients diagnosed with non‐M3 AML as well as 10 healthy individuals were collected and the mRNA expression levels of PPARγ and PTEN were evaluated. Additionally, we used trypan blue assay, MTT assay, and flow cytometry analysis to evaluate the anti‐leukemic effects of pioglitazone on U937 cells. Results: While PTEN was significantly downregulated in AML patients as compared to the control group, the expression of PPARγ was increased in the patients' group. The expression level of PPARγ was also negatively correlated with PTEN; however, it was not statistically significant. Besides, PPARγ stimulation using pioglitazone reduced survival and proliferative capacity of U937 cells through inducing apoptosis and suppression of cell transition from the G1 phase of the cell cycle. Conclusion: The results of the present study shed more light on the importance of PPARγ and its stimulation in the therapeutic strategies of AML. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of the current study is to evaluate the effect of silibinin on human hepatocellular carcinoma HepG-2 cells. Microculture tetrazolium test (MTT assay), Lactate dehydrogenase (LDH) release, Gelatin zymography, Griess reaction, Cell-based the extracelluar signal-regulated kinase (ERK) 1/2 phosphorylation assay and quantitative real-time RT-PCR were employed to appraise the effect of silibinin on cell proliferation, cytotoxicity, metastatic potential, nitric oxide (NO) production, ERK 1/2 phosphorylation and activation in HepG-2 cells. Silibinin inhibited cell proliferation, matrix metalloproteinase 2 enzymatic activity, NO production and ERK 1/2 phosphorylation in a dose-dependent manner without exerting any cytotoxicity effect. In addition, an expressive increase in mRNA levels of Raf kinase inhibitor protein (RKIP), sprouty-related protein 1 with EVH-1 domain (Spred-1), sprouty-related protein with EVH-1 domain 2 (Spred-2) coupled with a significant reduction in transcriptional levels of highly expressed in cancer (Hec1) and MMP-2 were observed. Altogether, these issues show for the first time that silibinin treatment could inhibit cell proliferation and invasive potential of HepG-2 cells through inhibition of ERK 1/2 cascade both directly (through suppression of ERK 1/2 phosphorylation) and indirectly (through up-regulation of RKIP, Spred-1 and Spred-2). In addition, cell growth and proliferation may be inhibited by silibinin through down-regulation of Hec1. [Copyright &y& Elsevier]

The toll‐like receptor (TLR) family consists of vital receptors responsible for pattern recognition in innate immunity, making them the core proteins involved in pathogen detection and eliciting immune responses. The most studied member of this family, TLR4, has been the center of attention regarding its contributory role in many inflammatory diseases including sepsis shock and asthma. Notably, mounting pieces of evidence have proved that this receptor is aberrantly expressed on the tumor cells and the tumor microenvironment in a wide range of cancer types and it is highly associated with the initiation of tumorigenesis as well as tumor progression and drug resistance. Cancer therapy using TLR4 inhibitors has recently drawn scientists' attention, and the promising results of such studies may pave the way for more investigation in the foreseeable future. This review will introduce the key proteins of the TLR4 pathway and how they interact with major growth factors in the tumor microenvironment. Moreover, we will discuss the many aspects of tumor progression affected by the activation of this receptor and provide an overview of the recent therapeutic approaches using various TLR4 antagonists. [ABSTRACT FROM AUTHOR]

Although the identification of tyrosine kinase inhibitors (TKIs) has changed the treatment paradigm of many cancer types including chronic myeloid leukemia (CML), still adjustment of neoplastic cells to cytotoxic effects of anticancer drugs is a serious challenge. In the area of drug resistance, epigenetic alterations are at the center of attention and the present study aimed to evaluate whether blockage of epigenetics mechanisms using a pan‐histone deacetylase (HDAC) inhibitor induces cell death in CML‐derived K562 cells. We found that the abrogation of HDACs using panobinostat resulted in a reduction in survival of the K562 cell line through p27‐mediated cell cycle arrest. Noteworthy, the results of the synergistic experiments revealed that HDAC suppression could be recruited as a way to potentiate cytotoxicity of Imatinib and to enhance the therapeutic efficacy of CML. Here, we proposed for the first time that the inhibitory effect of panobinostat was overshadowed, at least partially, through the aberrant activation of the phosphoinositide 3‐kinase (PI3K)/c‐Myc axis. Meanwhile, we found that upon blockage of autophagy and the proteasome pathway, as the main axis involved in the activation of autophagy, the anti‐leukemic property of the HDAC inhibitor was potentiated. Taken together, our study suggests the beneficial application of HDAC inhibition in the treatment strategies of CML; however, further in vivo studies are needed to determine the efficacy of this inhibitor, either as a single agent or in combination with small molecule inhibitors of PI3K and/or c‐Myc in this malignancy. [ABSTRACT FROM AUTHOR]

At the forefront of the battle against pathogens or any endogenously released molecules, toll‐like receptors (TLRs) play an important role as the most noble pattern recognition receptors. The ability of these receptors in distinguishing "self" and "non‐self" antigens is a cornerstone in the innate immunity system; however, misregulation links inflammatory responses to the development of human cancers. It has been known for some time that aberrant expression and regulation of TLRs not only endows cancer cells an opportunity to escape from the immune system but also supports them through enhancing proliferation and angiogenesis. Over the past decades, cancer research studies have witnessed a number of preclinical and clinical breakthroughs in the field of TLR modulators and some of the agents have exceptionally performed well in advanced clinical trials. In the present review, we have provided a comprehensive review of different TLR agonists and antagonists and discuss their limitations, toxicities, and challenges to outline their future incorporation in cancer treatment strategies. [ABSTRACT FROM AUTHOR]

Purpose: The clinical studies carried out in the last few decades unequivocally introduced activated androgen receptor (AR) as a pathogenic feature of human malignancies which not only endows cancer cells with survival advantage, but also may be exploited for anticancer interventions. Patients and Methods: In this study, we have investigated the expression profile of AR and EMT-related genes in fresh gastric cancer (GC), adjacent nontumor and normal gastric tissues, as well as the effect and molecular mechanisms of AR inhibition in GC cell lines. Results: Amongst 60 GC patients, 66.7% overexpressed AR that was remarkably correlated with the overexpression of Snail, β-catenin, Twist1, and STAT3. AR overexpression was also remarkably associated with unfavorable outcome (HR=3.478, P=0.001); however, multivariate Cox regression analysis indicated that it was not an independent prognostic factor (HR=2.089, P=0.056). This study has investigated simultaneous assessment of AR and EMT-related genes expression and indicated that concurrent overexpression of AR and Snail is an independent unfavorable factor for GC overall survival after adjustment with other variables (HR=2.382, P=0.021). Interestingly, the inhibition of AR signaling by potent AR antagonist enzalutamide suppressed cell growth, migration and invasion of GC cells via regulation of apoptosis-, cell cycle-, and EMT-related gene expressions. Conclusion: Our findings have clinical importance proposing AR as an important prognostic factor involved in GC progression and metastasis, and submit AR inhibition as an appealing therapeutic approach for GC patients, either as a single agent or in a combined-modal strategy. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is the most common and lethal subtype of pancreatic cancer, with a 5-year survival rate of < 3%. Early tumor dissemination, late diagnosis and insensitivity to conventional treatment are the major reasons for its high mortality rate. Members of the vascular endothelial growth factor (VEGF) family are overexpressed in PDAC and play important roles in its malignant progression, suggesting that VEGF-targeted therapies may interrupt the proliferation and motility of PDAC cells. Here, we evaluated the anti-tumor activity of cediranib, a pan-VEGF receptor inhibitor, on PDAC cells. Methods: Anti-proliferative effects of cediranib were determined using cell proliferation and crystal violet staining assays. Annexin V/PI staining, radiation therapy, and cell migration and invasion assays were carried out to examine the effects of cediranib on apoptosis, radio-sensitivity and cell motility, respectively. Quantitative reverse transcription-PCR (qRT-PCR) and Western blot analyses were applied to elucidate the molecular mechanisms underlying the anti-tumor activity of cediranib. Results: We found that cediranib decreased PDAC cell proliferation and clonogenic survival and induced apoptotic cell death through inhibition of the anti-apoptotic proteins cIAP1, XIAP, MCL-1 and survivin. Combination with cediranib synergistically increased the sensitivity of PDAC cells to chemotherapeutic agents such as gemcitabine and paclitaxel, and potentiated the effects of radiation therapy on PDAC cell growth inhibition and apoptosis induction. Furthermore, we found that treatment with cediranib impaired PDAC cell migration and invasion via expression reduction of the epithelial-to-mesenchymal transition (EMT) markers ZEB1, N-cadherin and Snail. Conclusions: Our data indicate that cediranib may exhibit anti-tumor activity in PDAC cells and provide a rationale for further investigation of the potential of VEGF receptor-targeted therapies for the treatment of PDAC. [ABSTRACT FROM AUTHOR]

Background: Lung cancer is the second most common cancer and the main cause of cancer-related mortality worldwide. In spite of various efforts that have been made to facilitate the early diagnosis of lung cancer, most patients are diagnosed when the disease is already in stage IV, which is generally associated with the occurrence of distant metastases and a poor survival. Moreover, a large proportion of these patients will relapse after treatment, heralding the need for the stratification of lung cancer patients in addition to identifying those who are at a higher risk of relapse and, thus, require alternative and/or additional therapies. Recently, circulating tumor cells (CTCs) have been considered as valuable markers for the early diagnosis, prognosis and risk stratification of cancer patients, and they have been found to be able to predict the survival of patients with various types of cancer, including lung cancer. Additionally, the characterization of CTCs has recently provided fascinating insights into the heterogeneity of tumors, which may be instrumental for the development of novel targeted therapies. Conclusions: Here we review our current understanding of the significance of CTCs in lung cancer metastasis. We also discuss prominent studies reporting the utility of enumeration and characterization of CTCs in lung cancer patients as prognostic and pharmacodynamic biomarkers for those who are at a higher risk of metastasis and drug resistance. [ABSTRACT FROM AUTHOR]

Background: Despite all advances in the treatment of ovarian cancer (OC), it remains the most lethal gynecological malignancy worldwide. There are growing amounts of evidence indicating the role of inflammation in initiating chemoresistance. Therefore, Toll-like receptor 4 (TLR4), a mediator of inflammation in cancer cells, may be a proper anticancer target.Methods: The effects of TLR4 activation by LPS was studied using MTT, colony formation, staining, scratch, and qRT-PCR assays as the first step. Then the same assays, in addition to anoikis resistance, cell cycle and annexin V/PI apoptosis tests, were used to investigate whether the inhibition of TLR4 using a small molecule inhibitor, TAK-242, could suppress the proliferation of various OC cell lines: A2780CP, 2008C13, SKOV3, and A2780S.Results: The activation of TLR4 using LPS showed enhanced proliferation and invasion in the TLR4-expressing cell line (SKOV3). Next, treatment with the inhibitor revealed that TAK-242 suppressed the inflammatory condition of ovarian cancer cells, as evident by the down-regulation of IL-6 gene expression. We also found that TAK-242 halted cancer cell proliferation by inducing cell cycle arrest and apoptosis through the modulation of genes involved in these processes. Given the fact that the overexpression of TLR4 contributes to drug resistance, it was tempting to investigate the effect of TAK-242 in a combined-modality strategy. Interestingly, we found enhanced cytotoxicity when TAK-242 was used in combination with doxorubicin.Conclusion: TAK-242 serves as an appealing therapeutic strategy in the TLR4-expressing OC cells, either in the context of monotherapy or in combination with a chemotherapeutic drug. [ABSTRACT FROM AUTHOR]

Aberrant promoter methylation of RASSF6 and RASSF10 occurs at a high frequency in acute lymphoblastic leukemia (ALL). Because of the complexity of the current minimal residual disease (MRD) detecting-methods, the DNA methylation status of the RASSF6 and RASSF10 genes could potentially become biomarkers for the assessment of MRD levels in ALL patients. The promoter methylation status of RASSF6 and RASSF10 was assessed by using methylation-specific PCR (MSP) in the DNA isolated from 280 peripheral blood (PB) samples taken at the time of diagnosis, day 14, 28, and from the subsequent 30-month follow-ups of 45 adult ALL patients. The relative methylation level obtained during the follow-ups by MSP was compared to the MRD results obtained by the amplification of IG/TCR clonal rearrangements using the allele-specific quantitative-PCR (ASO-PCR) assay. Frequently, RASSF6 was methylated in B-ALL, and RASSF10 was methylated in T-ALL. The applicability and accuracy of the assays were increased when these markers were combined (91.1% and 93.8%, respectively). When a cutoff was defined for the PCR-MRD level, results of the 30 months of MRD detection showed a significant correlation between the PCR and MSP techniques (r = 0.848; p < 0.001). Due to the high applicability, the non-invasiveness, and promising prospect of longitudinal assessment, the DNA methylation status of the RASSF6 and RASSF10 genes could be potential biomarkers for the assessment of residual disease in PB of patients with ALL. [ABSTRACT FROM AUTHOR]

Background: It is well-known that Aurora kinase A (AURKA) shows oncogenic properties in various tumor types including gastric cancer (GC). Moreover, previous studies have demonstrated that AURKA has a specific androgen receptor (AR) binding site in its promoter; thus, it could be regulated by AR. Since it has been shown that AR overexpresses in gastric cancer (GC) as a male-predominant tumor, the goal of this study was to evaluate the association between AR and AURKA and its prognostic value in GC patients. Materials and Methods: We assessed the expression profile of AURKA in 60 fresh GC and adjacent non-tumor tissues and 50 normal gastric specimen by qRT-PCR, and investigated the association of AURKA expression with clinicopathological features. Furthermore, we evaluated possible correlation between AURKA and AR to elucidate a novel prognostic marker using Kaplan-Meier method and Cox regression model. Conclusion: Among GC patients, 65% (39/60) overexpressed AURKA relative to normal gastric tissues. AURKA overexpression was significantly correlated with the AR overexpression in GC patients. Although AURKA expression alone was not remarkably associated with poor outcome, we provided some evidence that combined evaluation of AURKA and AR expression could independently predict survival of GC patients adjusted for other variables (HR=1.7, CI=1.314-3.833 p=0.042). Conclusion: These results indicate that AR and AURKA may crosstalk to promote GC progression. Our findings have clinical importance because they suggest simultaneous assessment of AURKA and AR expression as a novel potential prognostic marker. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, is the fourth most common cause of cancer-related death in the USA. Local progression, early tumor dissemination and low efficacy of current treatments are the major reasons for its high mortality rate. The ERBB family is over-expressed in PDAC and plays essential roles in its tumorigenesis; however, single-targeted ERBB inhibitors have shown limited activity in this disease. Here, we examined the anti-tumor activity of dacomitinib, a pan-ERBB receptor inhibitor, on PDAC cells. Methods: Anti-proliferative effects of dacomitinib were determined using a cell proliferation assay and crystal violet staining. Annexin V/PI staining, radiation therapy and cell migration and invasion assays were carried out to examine the effects of dacomitinib on apoptosis, radio-sensitivity and cell motility, respectively. Quantitative reverse transcription-PCR (qRT-PCR) and Western blot analyses were applied to elucidate the molecular mechanisms underlying the anti-tumor activity of dacomitinib. Results: We found that dacomitinib diminished PDAC cell proliferation via inhibition of FOXM1 and its targets Aurora kinase B and cyclin B1. Moreover, we found that dacomitinib induced apoptosis and potentiated radio-sensitivity via inhibition of the anti-apoptotic proteins survivin and MCL1. Treatment with dacomitinib attenuated cell migration and invasion through inhibition of the epithelial-to-mesenchymal transition (EMT) markers ZEB1, Snail and N-cadherin. In contrast, we found that the anti-tumor activity of single-targeted ERBB agents including cetuximab (anti-EGFR mAb), trastuzumab (anti-HER2 mAb), H3.105.5 (anti-HER3 mAb) and erlotinib (EGFR small molecule inhibitor) were marginal. Conclusions: Our findings indicate that dacomitinib-mediated blockade of the ERBB receptors yields advantages over single-targeted ERBB inhibition and provide a rationale for further investigation of the therapeutic potential of dacomitinib in the treatment of ERBB-driven PDAC. [ABSTRACT FROM AUTHOR]

Numerous links exist between inflammation and tumor development. Toll-like receptor 4 (TLR4) expression by tumor cells can be a contributing factor that promotes tumor cell proliferation, survival, migration, and metastasis. In this study, we explored the impact of TLR4 inhibition using TAK-242, a specific inhibitor of TLR4, on the invasion properties of ovarian (A2780CP, 2008C13, SKOV3, and A2780S) and breast (MCF7, SKBR3, MDA-MB-231, and BT-474) cancer cell lines. Six out of eight cell lines expressed TLR4 and its downstream mediators (MyD88, NF-ĸB1, and RELB), indicating that these cell lines could be proper candidates for the TLR4 inhibition. TAK-242 induced a cytotoxic effect on all tested cell lines; however, a different cell sensitivity pattern was noticeable. Interestingly, in the TLR4-expressing cell lines, there was a significant correlation between the TLR4/MyD88 expressions and the cancer cell response to TAK-242: the higher the expression, the higher the IC 50. To the best of our knowledge, no study has addressed the effects of TAK-242 on invasive abilities of cancer cells and our study suggests for the first time that TAK-242 could considerably decrease invasion properties of ovarian and breast cancer cell lines. We found that not only did TAK-242 reduce the enzymatic activity of MMP2 and MMP9, but also down-regulated gene expressions of epithelial-mesenchymal transition (EMT)-related genes. In sum, it seems that targeting TLR4 using TAK-242 possesses novel promising potential in cancer treatment strategies and may prevent invasion in patients suffering from ovarian and breast cancers, especially in those with over-expression of TLR4. [ABSTRACT FROM AUTHOR]

Abstract Telomerase-mediated immortalization and proliferation of tumor cells is a promising anti-cancer treatment strategy and development of potent telomerase inhibitors is believed to open new window of treatments in human malignancies. In the present study, we found that BIBR1532, a small molecule inhibitor of human telomerase, exerted cytotoxic effects on a panel of human cancer cells spanning from solid tumors to hematologic malignancies; however, as compared with solid tumors, leukemic cells were more sensitive to this inhibitor. This was independent of molecular status of p53 in the leukemic cells. The results of a miRNA PCR array revealed that BIBR1532-induced cytotoxic effects in NB4, the most sensitive cell line, was coupled with alteration in a substantial number of cancer-related miRNAs. Interestingly, most of these miRNAs were found to act as tumor suppressors with validated targets in cell cycle or nuclear factor (NF)-κB–mediated apoptosis. In accordance with a bioinformatics analysis, our experimental studies showed that BIBR1532-induced apoptosis is mediated, at least partly, by inhibition of NF-κB. Moreover, we found that the alteration in the expression of miRNAs was coupled with the alteration in the cell cycle progression. To sum up with, a straightforward interpretation of our results is that telomerase inhibition using BIBR1532 not only induced CDKN1A-mediated G1 arrest in NB4, but also resulted in a caspase-3-dependent apoptotic cell death mostly through suppression of NF-κB axis. [ABSTRACT FROM AUTHOR]

Abstract While a batch of efforts are fastened on synthesizing the novel targeted anti-cancer agents, recent investigations have achieved a breakthrough in identifying a favorable anti-tumor activity for some supportive drugs, which their safety have been confirmed thus far. The results of the present study highlighted the efficacy of Aprepitant, an oral antagonist of the neurokinin-1 receptor (NK1R), against both APL (NB4) and pre-B ALL (Nalm-6) cell lines; however, a differential sensitivity pattern was found in these cells. To the best of our knowledge, this is the first time that the molecular mechanisms of resistance to Aprepitant have been investigated and, herein, we proposed that the effectiveness of Aprepitant could be overshadowed, at least partially, through over-activated nuclear factor-κB in Nalm-6 pre-B ALL cells. In contrast to Nalm-6, the cytotoxic property of Aprepitant in NB4 was divulged at the lower concentrations. Of particular interest, we found that the cytotoxicity of the inhibitor became even more evident in the synergistic experiments, where an enhanced reduction in viability was noted after treatment of NB4 cells with ATO-plus-Aprepitant. The stimulatory effect of NK1R inhibition on ATO cytotoxicity is probably mediated through up-regulation of p73, which can subsequently engage p21 and NF-κB pathway via transcriptional suppression of c-Myc. Taken together, the present study suggests that inhibition of NK1R using Aprepitant, either alone or in combination with chemotherapeutic drugs, could be a novel therapeutic strategy for the treatment of acute leukemia, especially APL, that may be clinically accessible in the near future. [ABSTRACT FROM AUTHOR]

MRD detection with allele-specific oligonucleotide-quantitative polymerase chain reaction (ASO-qPCR) and using clone-specific immunoglobulin/T cell receptor rearrangements is considered as a powerful prognostic factor in acute lymphoblastic leukemia (ALL). In the present study, we evaluated an ASO-qPCR assay for MRD quantification in peripheral blood (PB) samples of adult patients with ALL. DNA was isolated from PB samples of patients with newly diagnosed ALL. They were first investigated by multiplex-PCR assay to identify V/J usage. An ASO-qPCR technique was then applied for 2.5-year monthly MRD quantification for detection of patient-specific Ig/TCR receptor rearrangements as a molecular target. From 98 patients who were diagnosed as ALL, 72 (73.5%) were enrolled in the present study for MRD detection. MRD was successfully quantified in patients with 1-month interval time. MRD level at the end of induction therapy up to day 88 was the only significant prognostic factor. Regarding MRD level, patients were categorized into two groups of low and high-risk. 2.5-year OS in all three time points (days 28, 58 and 88) were significantly lower in high-risk group (P < 0.008). The results of the 2.5-year MRD detection indicate that MRD level at the end of induction up to about 6 months after the first diagnosis was associated with clinical outcome. This study may highlight the usefulness of PB and the definitions of cut-off level for early prediction of relapse and for stratifying ALL patients. Short-interval time points and frequent PB sampling to monitor MRD level is suggested for early clinical relapse prediction and clinical management of the disease. [ABSTRACT FROM AUTHOR]

Glioblastoma multiform (GBM) accounts for the most common form of primary brain tumors with very limited survival rate. Drug resistance is the main challenges for good prognosis of GBM patients. Arsenic trioxide (ATO) as a multifunctional drug has been investigated for the treatment of several solid tumors. Amplification/overexpression of the epidermal growth factor receptor (EGFR) gene as a signature genetic abnormality of GBM tumors can be a chemoresistance mechanism. In this study, we use erlotinib as an EGFR inhibitor to increase the sensitivity of GBM cell lines to ATO treatment. We evaluate the effects of this combination on metabolic activity, viability, cell proliferation, colony formation, cell cycle distribution, migration, oxidative stress and reactive oxygen species production. Our results showed that combination of ATO with erlotinib synergistically reduced metabolic activity, proliferation and colony forming potential in treated GBM cell lines. This combination induced G2/M cell cycle arrest. We also found that wound-healing rate were suppressed only after combination treatment. In addition, apoptotic cell death and reactive oxygen species content significantly increased after combination treatment. The combination of ATO and erlotinib considerably interfere with survival and migration of treated GBM cell lines through cell cycle arrest and reactive oxygen species production. Present study uncovered that EGFR inhibition could overcome the resistance of glioblastoma cells to ATO treatment. [ABSTRACT FROM AUTHOR]

PML-RARα perturbs the normal epigenetic setting, which is essential to oncogenic transformation in acute promyelocytic leukemia (APL). Transcription induction and recruitment of DNA methyltransferases (DNMTs) by PML-RARα and subsequent hypermethylation are components of this perturbation. Arsenic trioxide (ATO), an important drug in APL therapy, concurrent with degradation of PML-RARα induces cell cycle change and apoptosis. How ATO causes cell cycle alteration has remained largely unexplained. Here, we investigated DNA methylation patterns of cell cycle regulatory genes promoters, the effects of ATO on the methylated genes and cell cycle distribution in an APL cell line, NB4. Analysis of promoter methylation status of 22 cell cycle related genes in NB4 revealed that CCND1, CCNE1, CCNF, CDKN1A, GADD45α, and RBL1 genes were methylated 60.7, 84.6, 58.6, 8.7, 33.4, and 73.7%, respectively, that after treatment with 2 μM ATO for 48 h, turn into 0.6, 13.8, 0.1, 6.6, 10.7, and 54.5% methylated. ATO significantly reduced the expression of DNMT1, 3A, and 3B. ATO induced the expression of CCND1, CCNE1, and GADD45α genes, suppressed the expression of CCNF and CDKN1A genes, which were consistent with decreased number of cells in G1 and S phases and increased number of cells in G2/M phase. In conclusion, demethylation and alteration in the expression level of the cell cycle related genes may be possible mechanisms in ATO-induced cell cycle arrest in APL cells. It may suggest that ATO by demethylation of CCND1 and CCNE1 and their transcriptional activation accelerates G1 and S transition into the G2/M cell cycle arrest. [ABSTRACT FROM AUTHOR]

The intertwining between cancer pathogenesis and perturbation of multitude signaling pathways ushered the cancer therapeutic approaches into an unbounded route of targeted therapies. For the nonce and among the plethora of promising inhibitors, intense interest has focused on small molecules targeting different component of PI3K axis. Intrigued by the constant activation of PI3K in leukemia, this study aimed to investigate the effects of BKM120, as the excelled member of pan PI3K inhibitors, in a panel of hematologic malignant cell lines. The resulting data showed that BKM120 exerted a concentration-dependent growth suppressive effect; however, IC 50 values varied among the tested cells. Our results outlined that the blockage of PI3K in NB4, as the most sensitive cell line, resulted in a caspase-3-dependent apoptosis probably through NFκB-mediated suppression of c-Myc and hTERT. As far we are aware, to date, there have been no reports of BKM120 effect on enzymatic repression of telomerase, and this study represents for the first time that the anti-proliferative effect of the inhibitor on NB4 is mediated by down-regulation of telomerase; shedding new light on the novel mechanism of action of BKM120. [ABSTRACT FROM AUTHOR]

Background The Hypermethylation of Ras association domain family (RASSF) often plays a key role in malignant progression of solid tumors; however, their impact on the prognosis and survival of adult ALL patients remain elusive. Methods The frequency of the promoter methylation pattern of RASSF6 and RASSF10 were analyzed in the peripheral blood (PB) samples taken at the time of diagnosis of 45 ALL patients. The methylation-specific PCR (MSP) assay was used to detect the DNA methylation patterns. Results RASSF6 was frequently hypermethylated in patients diagnosed with pre-B-ALL (90.9%) and B-ALL (87.5%), followed by T-ALL (66.7%); whereas, RASSF10 methylation was more confined to T-ALL (80%) as compared to B-ALL (25%) and pre-B ALL (9.1%) patients. Moreover, hypermethylation of RASSF6 was significantly associated with a poor prognosis and shorter overall survival (OS) in patients with pre-B-ALL (log-rank test; P = 0.041). Conclusion RASSF6 and RASSF10 were frequently hypermethylated in the samples at the time of diagnosis of adult ALL patients. Our study represents the first report of methylation of RASSF6 at a high frequency in patients with pre-B ALL. Furthermore, hypermethylation of RASSF6 was significantly associated with inferior overall survival in pre-B ALL patients. It may suggest that the frequent epigenetic inactivation of RASSF6 plays an important role in the pathogenesis and progression of pre-B-ALL. [ABSTRACT FROM AUTHOR]

The impressive advances carried out in designing pharmacological strategies with the aim of telomerase inhibition in cancers emerged a consensus that telomerase-targeted therapies could be exciting prospect in repertoire of future cancer strategies. The results of the present study indicated that targeting telomerase using an oligonucleotide-based molecule against human telomerase RNA template (hTR ASODN) reduced the survival rate of NB4 cells and induced a caspase-3-dependent apoptosis. Our finding was even noticeable in the synergistic experiments, where we found an enhanced reduction in the viability of the cells after short-term treatment with ATO in combination with the inhibitor. The resulting data delineated that short-term treatment of the cells with hTR ASODN either as single agent or in combination with ATO resulted in apoptotic cell death through activation of DNA damage response via up-regulation of p73 and ATM coupled with down-regulation of c-Myc. Moreover, we found that induction of p21 and subsequent disturbance of the death promoter to death repressor genes may contribute to the enhanced growth suppressive effect of the drugs combination. Overall, our findings support the idea that telomerase activity may have pivotal role in attenuating ATO effectiveness and combination of ATO with telomerase inhibitor seems to be a novel promising strategy, which may increase APL cure rates. [ABSTRACT FROM AUTHOR]

Objectives:Interest into targeting telomerase in cancer has increased by the recent disclosure that elevated telomerase activity is associated with disease recurrence and poor outcome in cancers. In addition, cellular acquisition of unlimited replicative potential, which is closely related to the maintenance of telomeres mostly via the reactivation of telomerase, has been shown to confer loss of sensitivity to a wide range of anti-neoplastic agents. Methods:To evaluate whether telomerase inhibition using non-nucleosidic inhibitor of telomerase BIBR1532 could enhance cytotoxic effect of doxorubicin in acute lymphoblastic leukemia, Nalm-6 pre-B ALL cells were subjected to combination treatment and subsequent cell viability, growth kinetics, caspase-3 activity, and transcriptional alteration of p73, p21, FOXO3a, c-Myc, hTERT, and other apoptosis-related target genes were investigated. Results:Combination of BIBR1532 with doxorubicin produced a synergistic anticancer effect probably through induction of p73. Transcription factor p73 not only suppressed the proliferative capacity of the cells through induction of p21-mediated G1 arrest, but also down-regulated the mRNA level of hTERT and c-Myc. Our results also report that BIBR1532 induced a caspase-dependent apoptosis, at least partially, through heightened ROS levels, and noteworthy enhanced the pro-oxidant property of doxorubicin. In harmony, transcriptional repression of survivin could be a probable underlying mechanism for the induction of apoptosis through shifting the ratio of death promoters to death repressors via alteration of Bax and Bcl2 expression. Conclusions:Overall, it seems that combination of BIBR1532 and doxorubicin could be a novel therapeutic strategy for acute lymphoblastic leukemia that may be clinically accessible in the near future. [ABSTRACT FROM AUTHOR]

Background: Disulfiram is oral aldehyde dehydrogenase (ALDH) inhibitor that has been used in the treatment of alcoholism. Recent studies show that this drug has anticancer properties; however, its rapid degradation has limited its clinical application. Encapsulation of disulfiram polymeric nanoparticles (NPs) may improve its anticancer activities and protect rapid degradation of the drug. Materials and Methods: A poly (lactide-co-Glycolide) (PLGA) was developed for encapsulation of disulfiram and its delivery into breast cancer cells. Disulfiram encapsulated PLGA NPs were prepared by nanoprecipitation method and were characterized by Scanning Electron Microscopy (SEM). The loading and encapsulation efficiency of NPs were determined using UV-Visible spectroscopy. Cell cytotoxicity of free and encapsulated form of disulfiram is also determined using MTT assay. Results: Disulfiram encapsulated PLGA NPs had uniform size with 165 nm. Drug loading and entrapment efficiency were 5.35 ±0.03% and 58.85±1.01%. The results of MTT assay showed that disulfiram encapsulated PLGA NPs were more potent in induction of apoptosis compare to free disulfiram. Conclusion: Based on the results obtained in the present study it can be concluded that encapsulation of disulfiram with PLGA can protect its degradation in improve its cytotoxicity on breast cancer cells. [ABSTRACT FROM AUTHOR]

Genetic and laboratory experiments have brought remarkable advances in management of human malignancies, which not only revolutionized the understanding of the disease, but also led to development of novel and effective targeted therapies against specific deregulated pathways. This study aimed to investigate anti-cancer effects of Idelalisib, a potent PI3K-δ inhibitor, in a panel of hematological cell lines. The resulting data showed that Idelalisib decreased cell survival in all the tested cell lines; however, as compared to NB4, viability of other cell lines, irrespective of their molecular characteristics or even the compensatory activation of MEK/ERK pathway, was inhibited at higher concentrations. This study suggests for the first time that there is a significant correlation between relative response to Idelalisib and basal expression levels of anti-apoptotic genes, in particular survivin and MCL-1. Intriguingly, we found that Idelalisib-induced apoptosis in NB4, as the most sensitive cell line with the lowest expression level of the aforementioned genes, is executed probably via alteration in the transcriptional level of apoptosis-related genes coupled with p21-mediated caspase-3 activation. Moreover, the lower concentrations of Idelalisib combined with arsenic trioxide (ATO) produced synergistic anti-cancer effect in APL-derived NB4 cells. Overall, due to the pharmacologic safety of Idelalisib and its broad clinical effectiveness in chronic lymphoproliferative disorders, our study suggests that this inhibitor is a promising agent for the treatment of acute promyelocytic leukemia, either as single agent or in a combined-modality strategy. [ABSTRACT FROM AUTHOR]

Aim In recent years, a few cases of chronic myeloid leukemia (CML) have been reported with both BCR-ABL and JAK2V617F mutations. Moreover, mutations in the additional sex comb-like 1 ( ASXL1) gene were recently shown in various myeloid malignancies.There were no previous studies investigating the incidence of the ASXL1 and JAK2V617F mutations in Iranian patients with CML. Consequently, this study focuses on the analysis of these mutations in patients with CML. Methods In total, 66 patients with a clinical diagnosis of CML were examined at the time of diagnosis. Thirty healthy subjects were checked as controls. Exon 12 of ASXL1 was amplified from genomic DNA and bidirectionally sequenced. We also performed JAK2V617F screening by amplification refractory mutation system-polymerase chain reaction and sequencing. Results Mutations in the ASXL1 gene were found in five out of 66 CML patients (7.6%). We identified a novel variant (c.1968G > A, p.Asp656Asn) in one of the patients that has not been reported before. We also identified BCR-ABL and JAK2V617F mutations simultaneously in four patients (6%). Conclusion Our demonstration of ASXL1 mutation, a putative tumor suppressor gene, represents an important molecular abnormality in CML. We also showed that concomitant detection of BCR-ABL and JAK2V617F mutations has a relatively high incidence in Iranian patients. [ABSTRACT FROM AUTHOR]

Aims Cell cycle dysregulation is important in tumorigenesis. Transcriptional silencing of cell cycle regulatory genes, due to DNA methylation, is a common epigenetic event in malignancies. As 2 O 3 has been shown to induce cell cycle arrest and also to be a potential hypomethylating agent. Our study aimed to investigate DNA methylation patterns of cell cycle regulatory genes promoters, the effects of Arsenic trioxide (As 2 O 3 ) on the methylated genes and cell cycle distribution in colorectal cancer (CRC) cell lines. Main methods The methylation-specific PCR (MSP) and/or restriction enzyme-based methods were used to study the promoter methylation patterns of 24 cell cycle regulatory genes in CRC cell lines. Gene expression level and cell cycle distribution were determined by Real-time PCR and flow cytometric analyses, respectively. Key findings Our methylation analysis indicated that only promoters of RBL1 (p107), CHFR and p16 genes were aberrantly methylated in three cell lines. As 2 O 3 significantly decreased DNA methylation in promoter regions of these genes and restored their expression. We found that As 2 O 3 significantly reduced the expression of DNA methyltransferase 1 (DNMT1) and increased arsenic methyltransferase (AS3MT). Furthermore, As 2 O 3 altered transcriptional activity of several unmethylated cell cycle regulatory genes including cyclin B 1, E1, D1, GADD45A and p21. Cell cycle flow cytometry analysis showed As 2 O 3 induced G2/M arrest in all three cell lines. Significance These data suggest that demethylation and alteration in the expression level of the cell cycle-related genes may be possible mechanisms in As 2 O 3 -induced cell cycle arrest in colorectal cancer cells. [ABSTRACT FROM AUTHOR]

Increasing number of genetic and cancer biology studies indicated a prominent role for tachykinin NK 1 receptor (NK 1 R) in cancer cell growth and survival. Considering the fact that neoplastic lymphoid precursors in acute lymphoblastic leukemia (ALL) carry a three- to four-fold NK 1 R expression as compared to normal lymphocytes, using NK 1 R antagonist seems to be noteworthy in the treatment of ALL patients. In this study, we found that inhibition of NK 1 R with aprepitant, a selective high-affinity antagonist of the human NK 1 R, exerts cytotoxic and anti-proliferative effects against pre-B ALL-derived Nalm-6 cells either as single drug or in combination with doxorubicin. Our data showed that treatment of the cells with the inhibitor resulted in apoptotic cell death, at least partly, through abrogation of PI3K/Akt pathway, as revealed by the reduction of phospho/total Akt ratio. In agreement with the inhibitory effect on Akt, we also found that aprepitant increased the expression level of p21 and p27, which in turn leads to the induction of G1 cell cycle arrest. Overall, this study recommends mechanistic pathways by which inhibition of NK 1 R can augment apoptotic cell death through a plausible p53-dependent pathway rather than NF-κB-depended mechanism in pre-B ALL cells; however, further studies are needed to better characterize the application of NK 1 R inhibition in clinical cancer treatment. [ABSTRACT FROM AUTHOR]

Complex interplay of intracellular signaling networks, spanning from the extracellular environment to the nucleus, orchestrate normal cell growth and survival. Dysregulation of such signals contributes to malignant transformation, thereby giving the cancer cells a survival advantage, but also could be exploited for new anticancer interventions. The aim of this study was to investigate the effects of pan class-I PI3K inhibitor NVP-BKM120 on two distinct acute leukemia cell lines, NB4 (with mutant p53) and Nalm-6 (with wild-type p53). Our data highlighted the efficacy of the inhibitor against APL and pre B ALL cell lines; however, we failed to find an obvious correlation between p53 status and the sensitivity of leukemic cells to NVP-BKM120. Real-time PCR analysis revealed a significant up-regulation of p53 target genes in Nalm-6 cells, indicating a p53-dependent mechanism involved in NVP-BKM120 cytotoxicity. On the other hand, cytotoxic effects in mutant p53-expressing NB4 cells seem to be mediated mostly by the inhibition of the PI3K/Akt/NF-κB axis. In conclusion, we suggest NVP-BKM120 induces apoptosis through p53-dependent and -independent mechanisms, indicating the potential application of the inhibitor in both wild-type and deficient p53-expressing leukemic cells. [ABSTRACT FROM AUTHOR]

Arsenic trioxide (ATO), a traditional Chinese medicine, has long been of biomedical interest and is largely used for treatment of a broad spectrum of cancers. Melatonin, a naturally occurring indoleamine synthesized in the pineal gland, has been considered as a biomarker for endocrine-dependent tumors, particularly breast cancer. An increasing number of studies indicate that melatonin could be an attractive candidate for combined therapy due to its anti-oxidant and cytotoxic activities. The aim of this study was to investigate the potentiating effect of melatonin on ATO-induced apoptosis in estrogen receptor (ER)-positive breast cancer cell line, MCF-7. Our data highlighted for the first time that pre-treating MCF-7 cells with physiological concentration of melatonin substantially augmented the cytotoxic effects of ATO as compared with either agent alone. Real-time PCR analysis revealed that apoptosis induction by the drugs combination was associated with increased p53 transcriptional activity followed by the elevated molecular ratio of Bax/Bcl-2. Moreover, induced p21, subsequent G1 cell cycle arrest and transcriptional suppression of survivin-mediated c-Myc and hTERT expression may contribute in the enhanced growth suppressive effect of ATO-plus-melatonin. Due to the safety profile of melatonin, our study suggests that using melatonin in combination with ATO might provide insight into a novel adjuvant therapy and may confer advantages for breast cancer treatment. [ABSTRACT FROM AUTHOR]

Aurora B kinase as a chromosomal passenger protein plays multiple roles in regulating mitosis and cytokinesis. The function of Aurora B in leukemic cells has made it an important treatment target. In this study, we explored the expressions of Aurora (A, B, and C) kinases in newly diagnosed acute promyelocytic leukemia (APL) patients. In addition, we investigated the effects of AZD1152 as a specific inhibitor of Aurora B on cell survival, DNA synthesis, nuclear morphology, apoptosis induction, cell cycle distribution, and gene expression in an APL-derived NB4 cell line. Our results showed that Aurora B was overexpressed in 88 % of APL patients. AZD1152 treatment of NB4 cells led to viability reduction and G2/M arrest followed by an increase in cell size and polyploidy induction. These giant cells showed morphological evidence of mitotic catastrophe. AZD1152 treatment induced activation of G2/M checkpoint which in turn led to transient G2/M arrest in a p21-independent manner. Lack of functional p53 in NB4 cells might provide an opportunity to escape from G2/M block and to endure repeated rounds of replication and polyploidy. Treated cells were probably eliminated via p73-mediated overexpression of BAX, PUMA, and APAF1 and downregulation of survivin and MCL-1. In summary, AZD1152 treatment led to endomitosis and polyploidy in TP53-mutated NB4 cells. These giant polyploid cells might undergo mitotic catastrophe and p73-mediated apoptosis. It seems that induction of polyploidy via AZD1152 could be a novel form of anti-cancer therapy for APL that may be clinically accessible in the near future. [ABSTRACT FROM AUTHOR]

Background: Myeloproliferative neoplasms (MPNs) are clonal malignant diseases that represent a group of conditions including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The aim of this study was to evaluate possible correlations between JAK2V617F allele burden and clinicohematologic characteristics in Iranian patients with MPNs. We also aimed at determining the correlation between JAK2V617F allele burden and use of cyto reductive treatment (hydroxyurea). Materials and Methods: We performed ARMS-PCR for all MPNs samples and subsequently performed realtime quantitative polymerase chain reaction (qRT-PCR) for JAK2V617F allele burden measurement using DNA from peripheral blood leukocytes. Results: Two distinct groups of patients were examined at a single time point: group A (n=40; 20 PV, 20 ET) was examined at the time of diagnosis; group B (n=85; 40 PV, 30 ET and 15 PMF) while under treatment with hydroxyurea (HU). The median allele burden of the JAK2 V617F was 72% for PV and 49% for ET patients at the time of diagnosis (p=0.01). For patients with HU treatment, we determined the median JAK2V617F allele burden to be 43%, 40%, and 46.5% in PV, ET and PMF patients; respectively. HU-treated PV patients had a significant lower%JAK2V617F than PV patients at the time of diagnosis (43% vs. 72%, p=0.005). In ET group, the relationship between the JAK2 V617F allele burden and leukocyte count was significant (p=0.02 and p=0.01 in untreated and treated patients, respectively). Conclusions: Our results showed that patients with PV have a higher JAK2V617F allele burden. Moreover, our study demonstrated that the JAK2V617F allele burden correlates with clinical features in ET group. We also showed hydroxyurea can affect the JAK2V617F allele burden in PV patients. [ABSTRACT FROM AUTHOR]

Valproic acid (VPA) has been identified as a histone deacetylase inhibitor, inducing differentiation in transformed cells. However, no study has shown the effect of VPA in the redifferentiation induction and stemness of anaplastic thyroid. Themain objective of this study was to evaluate the efficacy of VPA as a differentiation therapy agent in human thyroid cancer based on its effect on stemness and differentiation process. Indications for differentiation of 8305C and B-CPAP cell lines following VPA treatment were obtained by analyzing cell proliferation rate, morphological changes, adherent-dependent colony formation, and Hoechst 33342 staining. The expressions of stemness, differentiation, and aggressiveness specific marker genes were measured by quantitative RT-PCR. VPA treatment effectively showed growth inhibition in both cell lines. The high nuclear-cytoplasmic (N : C) ratio of8305C cells markedly decreased and treated cells became more epithelial-like. Treated cells showed stronger Hoechst 33342 fluorescence compared with control cells. The hTERT and OCT-4 reduction was paralleled with adherent-dependent colony formation decrement in both cell lines. VPA effectively induced NIS and TTF-1 in anaplastic cells, it whereas showed no clear pattern in papillary cell line. VPA treatment also resulted in the reduction of MMP-2 and MMP-9. These finding suggest that VPA could redifferentiate the anaplastic thyroid cancer cells. [ABSTRACT FROM AUTHOR]

Valproic acid (VPA) has been identified as a histone deacetylase inhibitor, inducing differentiation in transformed cells. However, no study has shown the effect of VPA in the redifferentiation induction and stemness of anaplastic thyroid. Themain objective of this study was to evaluate the efficacy of VPA as a differentiation therapy agent in human thyroid cancer based on its effect on stemness and differentiation process. Indications for differentiation of 8305C and B-CPAP cell lines following VPA treatment were obtained by analyzing cell proliferation rate, morphological changes, adherent-dependent colony formation, and Hoechst 33342 staining. The expressions of stemness, differentiation, and aggressiveness specific marker genes were measured by quantitative RT-PCR. VPA treatment effectively showed growth inhibition in both cell lines. The high nuclear-cytoplasmic (N : C) ratio of8305C cells markedly decreased and treated cells became more epithelial-like. Treated cells showed stronger Hoechst 33342 fluorescence compared with control cells. The hTERT and OCT-4 reduction was paralleled with adherent-dependent colony formation decrement in both cell lines. VPA effectively induced NIS and TTF-1 in anaplastic cells, it whereas showed no clear pattern in papillary cell line. VPA treatment also resulted in the reduction of MMP-2 and MMP-9. These finding suggest that VPA could redifferentiate the anaplastic thyroid cancer cells. [ABSTRACT FROM AUTHOR]

Glioblastoma (GB) is the most aggressive type of brain tumor. Rapid progression, active angiogenesis, and therapy resistance are major reasons for its high mortality. Elevated expression of members of the vascular endothelial growth factor (VEGF) family suggests that anti-VEGF therapies may be potent anti-glioma therapeutic approaches. Here, we evaluated the anti-tumor activity of cediranib, a pan inhibitor of the VEGF receptors, on GB cells. Anti-proliferative effects of cediranib were determined using MTT, crystal-violet staining, clonogenic and anoikis resistance assays. Apoptosis induction was assessed by Annexin V/PI staining and Western blot analysis and aggressive abilities of GB cells were investigated using cell migration/invasion assays and zymography. Small-interfering RNA (siRNA)-mediated Knockdown was used to study resistance mechanisms. The anti-proliferative and apoptotic effects of cediranib in combination with radiotherapy, temozolomide, bevacizumab were also evaluated using MTT, Annexin V/PI staining and Western blot analysis for cleaved PARP-1. Cediranib reduced GB cell proliferation, induced apoptotic cell death and inhibited the aggressive abilities of GB cells. Cediranib synergistically increased the anti-proliferative and apoptotic effects of radiotherapy and bevacizumab and augmented the sensitivity of GB cells to temozolomide chemotherapy. In addition, knockdown of MET and AKT potentiated cediranib sensitivity in cediranib-resistant GB cells. These findings suggest that cediranib, alone or in combination with other therapeutics, is a promising strategy for the treatment of GB and provide a rationale for further investigation of the therapeutic potential of cediranib for the treatment of this fatal malignancy. [ABSTRACT FROM AUTHOR]