Immune landscape of hepatocellular carcinoma: From dysregulation of the immune responses to the potential immunotherapies.

Hepatocellular carcinoma (HCC) presents a considerable global health burden due to its late diagnosis and high morbidity. The liver's specific anatomical and physiological features expose it to various antigens, requiring precise immune regulation. To the best of our knowledge, this is the first time that a comprehensive overview of the interactions between the immune system and gut microbiota in the development of HCC, as well as the relevant therapeutic approaches are discussed. Dysregulation of immune compartments within the liver microenvironment drives HCC pathogenesis, characterized by elevated regulatory cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells, and M2 macrophages as well as suppressive molecules, alongside reduced number of effector cells like T cells, natural killer cells, and M1 macrophages. Dysbiosis of gut microbiota also contributes to HCC by disrupting intestinal barrier integrity and triggering overactivated immune responses. Immunotherapy approaches, particularly immune checkpoint inhibitors, have exhibited promise in HCC management, yet adoptive cell therapy and cancer vaccination research are in the early steps with relatively less favorable outcomes. Further understanding of immune dysregulation, gut microbiota involvement, and therapeutic combination strategies are essential for advancing precision immunotherapy in HCC.

C-Myc inhibition intensified the anti-leukemic properties of Imatinib in chronic myeloid leukemia cells.

BACKGROUND: Due to its remarkable efficacy in producing hematologic, cytogenetic, and molecular remissions, the FDA approved Imatinib as the first-line treatment for newly diagnosed Chronic Myeloid Leukemia (CML) patients. However, in some patients, failure to completely eradicate leukemic cells and the escape of these cells from death will lead to the development of resistance to Imatinib, and many are concerned about the prospects of this Tyrosine Kinase Inhibitor (TKI). It has been documented that the compensatory overexpression of c-Myc is among the most critical mechanisms that promote drug efflux and resistance in CML stem cells. METHODS: In order to examine the potential of c-Myc inhibition through the use of 10058-F4 to enhance the anti-leukemic properties of Imatinib, we conducted trypan blue and MTT assays. Additionally, we employed flow cytometric analysis and qRT-PCR to assess the effects of this combination on cell cycle progression and apoptosis. RESULTS: The findings of our study indicate that the combination of 10058-F4 and Imatinib exhibited significantly stronger anti-survival and anti-proliferative effects on CML-derived-K562 cells in comparison to either agent administered alone. It is noteworthy that these results were also validated in the CML-derived NALM-1 cell line. Molecular analysis of this synergistic effect revealed that the inhibition of c-Myc augmented the efficacy of Imatinib by modulating the expression of genes related to cell cycle, apoptosis, autophagy, and proteasome. CONCLUSIONS: Taken together, the findings of this investigation have demonstrated that the suppression of the c-Myc oncoprotein through the use of 10058-F4 has augmented the effectiveness of Imatinib, suggesting that this amalgamation could offer a fresh perspective on an adjunctive treatment for individuals with CML. Nevertheless, additional scrutiny, encompassing in-vivo examinations and clinical trials, is requisite.

The effects of Abemaciclib on cell cycle and apoptosis regulation in anaplastic thyroid cancer cells.

BACKGROUND: Anaplastic thyroid cancer (ATC) is an aggressive subtype of thyroid cancer, accounting for 1 to 2% of all cases. Deregulations of cell cycle regulatory genes including cyclins, cyclin-dependent kinases (CDKs), and endogenous inhibitors of CDKs (CKIs) are hallmarks of cancer cells and hence, studies indicate the inhibition of CDK4/6 kinases and cell cycle progression as potent therapeutic strategies. In this study, we investigated the anti-tumor activity of Abemaciclib, a CDK4 and CDK6 inhibitor, in ATC cell lines. METHODS AND RESULTS: The ATC cell lines C643 and SW1736 were selected to study the antiproliferative effects of Abemaciclib using a cell proliferation assay and crystal violet staining assay. Annexin V/PI staining and cell cycle analysis by flow cytometry were also performed to examine the effects on apoptosis induction and cell cycle arrest. Wound healing assay and zymography analysis examined the effects of the drug on invasive abilities of ATC cells and Western blot analyses were applied to further study the anti-tumor mechanism of Abemaciclib, in addition to combination treatment with alpelisib. Our data demonstrated that Abemaciclib significantly inhibited cell proliferation and increased cellular apoptosis and cell cycle arrest in ATC cell lines, while considerably reducing cell migration and colony formation. The mechanism seemed to involve the PI3K pathway. CONCLUSION: Our preclinical data highlight CDK4/6 as interesting therapeutic targets in ATC and suggest CDK4/6-blockade therapies as promising strategies in this malignancy.

Synergistic effects of BKM120 and panobinostat on pre-B acute lymphoblastic cells: an emerging perspective for the simultaneous inhibition of PI3K and HDACs.

The reputation of conventional treatment in acute lymphoblastic leukemia (ALL) has recently been questioned due to the considerable increment in the number of relapsed patients. The remarkable role of histone deacetylase (HDAC) enzymes in induction of chemo-resistance has provided an opportunity for HDAC inhibitors to be used as a treatment strategy in ALL; however, the compensatory activation of oncogenic pathways may negatively affect their promising effects. In the present study, we found an attenuating effect for PI3K axis on the anti-leukemic effects of panobinostat in pre-B ALL-derived Nalm-6 cells, as the harnessing of this pathway using BKM120 or CAL-101 resulted in a significant reduction in the number of viable cells as well as the metabolic activity. Moreover, we found the altered expression of p21, p27, c-Myc, and CDK4 upon co-treatment of the cells with panobinostat and BKM120, which was associated with a substantial blockage of cell cycle progression at G2/M phase. The companionship of the PI3K inhibitor with HDAC inhibitor also potentiated panobinostat-induced apoptotic cell death and enhanced the mRNA of Foxo3a and Foxo4. Conclusively, this study sheds light on the adjuvantive effects of BKM120 on panobinostat efficacy and outlined that the simultaneous inhibition of PI3K and HDACs may be a promising therapeutic approach to improve the cure rates of ALL.

Cancer stem cell phosphatases.

Cancer stem cells (CSCs) are involved in the initiation and progression of human malignancies by enabling cancer tissue self-renewal capacity and constituting the therapy-resistant population of tumor cells. However, despite the exhausting characterization of CSC genetics, epigenetics, and kinase signaling, eradication of CSCs remains an unattainable goal in most human malignancies. While phosphatases contribute equally with kinases to cellular phosphoregulation, our understanding of phosphatases in CSCs lags severely behind our knowledge about other CSC signaling mechanisms. Many cancer-relevant phosphatases have recently become druggable, indicating that further understanding of the CSC phosphatases might provide novel therapeutic opportunities. This review summarizes the current knowledge about fundamental, but yet poorly understood involvement of phosphatases in the regulation of major CSC signaling pathways. We also review the functional roles of phosphatases in CSC self-renewal, cancer progression, and therapy resistance; focusing particularly on hematological cancers and glioblastoma. We further discuss the small molecule targeting of CSC phosphatases and their therapeutic potential in cancer combination therapies.

Abrogation of histone deacetylases (HDACs) decreases survival of chronic myeloid leukemia cells: New insight into attenuating effects of the PI3K/c-Myc axis on panobinostat cytotoxicity.

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.

Minocycline attenuates depressive-like behaviors in mice treated with the low dose of intracerebroventricular streptozotocin; the role of mitochondrial function and neuroinflammation.

Neuroinflammation and mitochondrial dysfunction are suggested as mechanisms which are implicated in the pathophysiology of depression. Streptozotocin (STZ) is known to produce immune-inflammatory responses and mitochondrial dysfunction in different types of animal models of disease (e.g. type-1 diabetes and Alzheimer's disease). Therefore, a single low dose of Streptozotocin (STZ; intracerebroventricular, i.c.v, 0.2 mg/mouse) was used to induce an animal model of depression. The present study aims to investigate the effects of short (24 h) and long (14 days) exposure to minocycline on STZ-induced depressive-like behaviors (n = 6-8), hippocampal oxidative state biomarkers (n = 4), and the expression of hippocampal genes related to innate immunity (n = 3) in the hippocampus of male adult mice. In addition, the protective effects of different modes of minocycline (acute pretreatment (20 mg/kg, 1 h before STZ), acute post-treatment (20 mg/kg, 24 h after STZ), chronic pretreatment (5 mg/kg/day for 14 days before STZ), and chronic post-treatment (5 mg/kg/day for 14 days after STZ) were compared with the STZ effects. As the data showed, both short and long effects of STZ were associated with the depressive-like behaviors, abnormal mitochondrial function, and upregulation of neuroinflammatory genes in the hippocampus. Different modes of minocycline treatment could attenuate the negative impact of STZ on animals. The data suggested that minocycline at a human therapeutic dose (5 mg/kg) had protective effects against acute cellular damage induced by oxidation and the consequent inflammatory responses.

Inhibition of bromodomain and extraterminal domain reduces growth and invasive characteristics of chemoresistant ovarian carcinoma cells.

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy worldwide. Development of chemoresistance and peritoneal dissemination are the major reasons for low survival rate in the patients. The bromodomain and extraterminal domain (BET) proteins are known as epigenetic 'readers,' and their inhibitors are novel epigenetic strategies for cancer treatment. Accumulating body of evidence indicates that epigenetic modifications have critical roles in development of EOC, and overexpression of the BET family is a key step in the induction of important oncogenes. Here, we examined the mechanistic activity of I-BET151, a pan-inhibitor of the BET family, in therapy-resistant EOC cells. Our findings showed that I-BET151 diminished cell growth, clonogenic potential, and induced apoptosis. I-BET151 inhibited cell proliferation through down-modulation of FOXM1 and its targets aurora kinase B and cyclin B1. I-BET151 attenuated migration and invasion of the EOC cells by down-regulation of epithelial-mesenchymal transition markers fibronectin, ZEB2, and N-cadherin. I-BET151 synergistically enhanced cisplatin chemosensitivity by down-regulation of survivin and Bcl-2. Our data provide insights into the mechanistic activity of I-BET151 and suggest that BET inhibition has potential as a therapeutic strategy in therapy-resistant EOC. Further in vivo investigations on the therapeutic potential of I-BET151 in EOC are warranted.

PI3K-δ inhibition using CAL-101 exerts apoptotic effects and increases doxorubicin-induced cell death in pre-B-acute lymphoblastic leukemia cells.

The frequency of dysregulated PI3K in acute lymphoblastic leukemia (ALL) coupled with the critical role of this signaling pathway in the acquisition of chemoresistant phenotype lend compelling weight to the application of PI3K inhibitors for the treatment of ALL. In this study, we found that abrogation of the PI3K pathway using CAL-101, a selective inhibitor of PI3K p110-δ, exerts a cytotoxic effect against Nalm-6 pre-B-ALL cells. Our results showed that the growth-suppressive effect is mediated, at least partially, by G1 arrest as a result of upregulated p21. CAL-101 also leads to induction of caspase-dependent apoptosis probably through reactive oxygen species-dependent upregulation of FOXO3a and subsequent induction of the proapoptotic target genes of p53. In conclusion, this study highlighted the potent efficacy of CAL-101 as either a single agent or in combination with doxorubicin in Nalm-6 cells; however, further investigation is needed to provide valuable clues to add this inhibitor for the treatment of ALL.

Effects of silibinin on growth and invasive properties of human ovarian carcinoma cells through suppression of heregulin/HER3 pathway.

Epithelial ovarian cancer (EOC) is the most fatal gynecological malignancy due to its high proliferative and invasive capacities. A heregulin (HRG)/HER3 autocrine loop increases proliferative and metastatic properties of EOC cells, suggesting that modulators of this signaling pathway may prove effective to trammel growth and motility of these cells. This study aimed to evaluate the effects of multi-tyrosine kinase inhibitor silibinin on proliferative and invasive characteristics of EOC cell lines OVCAR8 and SKOV3 through suppression of the HRG/HER3 pathway. To achieve this, the effects of silibinin on proliferation, DNA synthesis, clonogenicity, cell cycle progression, cathepsin B enzymatic activity, and migration and invasion were explored in vitro. Silibinin suppressed proliferation, DNA synthesis, and clonogenic abilities of OVCAR8 and SKOV3 cells through inhibition of the autocrine HRG/HER3 circuit. Silibinin-mediated attenuation of the HER3 signaling disabled the HER3/AKT/survivin axis and thereby, induced G1/S cell cycle arrest. Furthermore, silibinin reduced invasive potentials of the EOC cells through quelling the HRG/HER3 pathway and suppression of cathepsin B activity. Altogether, these results suggest that silibinin is a potential anti-cancer drug to inhibit proliferative and invasive characteristics of the EOC cells that exhibit an autocrine HRG/HER3 pathway.

A simple and rapid in vitro assay for identification of direct inhibitors of O6-methylguanine-DNA methyltransferase.

O6-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that is overexpressed in certain tumors and is associated with resistance to the DNA alkylating agent temozolomide. MGMT inhibitors show potential in combating temozolomide resistance, but current assays for MGMT enzyme activity and inhibition, primarily oligonucleotide-based and fluorescent probe-based, are laborious and costly. The clinical relevance of temozolomide therapy calls for more convenient methodologies to study MGMT inhibition. Here, we extended the application of SNAP-Capture magnetic beads to develop a novel MGMT inhibition assay that demonstrated efficacy not only with known MGMT inhibitors, but also with the aldehyde dehydrogenase inhibitor, disulfiram. The assay uses standard fluorescence microscopy as a simple and reliable detection method, and is translationally applicable in drug discovery programs.

A cell line expressing MGMT-GFP fusion protein was generated. After harvesting the cells, the cell lysate was prepared and combined with SNAP-Capture magnetic beads and incubated at room temperature. Successful immobilization of MGMT-GFP on SNAP-Capture magnetic beads was verified by fluorescence microscopy. For the MGMT inhibition assay, the cell lysate underwent pre-treatment with established MGMT inhibitors before interaction with SNAP-capture magnetic beads and then underwent immobilization and fluorescence microscopy.

DNA methylation in human diseases.

Aberrant epigenetic modifications, particularly DNA methylation, play a critical role in the pathogenesis and progression of human diseases. The current review aims to reveal the role of aberrant DNA methylation in the pathogenesis and progression of diseases and to discuss the original data obtained from international research laboratories on this topic. In the review, we mainly summarize the studies exploring the role of aberrant DNA methylation as diagnostic and prognostic biomarkers in a broad range of human diseases, including monogenic epigenetics, autoimmunity, metabolic disorders, hematologic neoplasms, and solid tumors. The last section provides a general overview of the possibility of the DNA methylation machinery from the perspective of pharmaceutic approaches. In conclusion, the study of DNA methylation machinery is a phenomenal intersection that each of its ways can reveal the mysteries of various diseases, introduce new diagnostic and prognostic biomarkers, and propose a new patient-tailored therapeutic approach for diseases.

DUSP6 inhibition overcomes neuregulin/HER3-driven therapy tolerance in HER2+ breast cancer.

Despite clinical benefits of tyrosine kinase inhibitors (TKIs) in cancer, most tumors can reactivate proliferation under TKI therapy. Here we present transcriptional profiling of HER2+ breast cancer cells transitioning from dormant drug tolerant cells to re-proliferating cells under continuous HER2 inhibitor (HER2i) therapy. Focusing on phosphatases, expression of dual-specificity phosphatase DUSP6 was found inhibited in dormant cells, but strongly induced upon regrowth. DUSP6 expression also selectively associated with poor patient survival in HER2+ breast cancers. DUSP6 overexpression conferred apoptosis resistance, whereas its pharmacological blockade prevented therapy tolerance development under HER2i therapy. DUSP6 targeting also synergized with clinically used HER2i combination therapies. Mechanistically DUSP6 is a positive regulator of HER3 expression, and its impact on HER2i tolerance was mediated by neuregulin-HER3 axis. In vivo, genetic targeting of DUSP6 reduced tumor growth in brain metastasis model, whereas its pharmacological targeting induced synthetic lethal therapeutic effect in combination with HER2i. Collectively this work demonstrates that DUSP6 drives escape from HER2i-induced dormancy, and that DUSP6 is a druggable target to overcome HER3-driven TKI resistance.

Multitargeting and antimetastatic potentials of silibinin in human HepG-2 and PLC/PRF/5 hepatoma cells.

Hepatocellular carcinoma (HCC) is the most common sort of primary liver malignancy with poor prognosis. This study aimed at examining the effects of silibinin (a putative antimetastatic agent) on some transcriptional markers mechanistically related to HCC recurrence and metastasis in HepG-2 [hepatitis B virus (HBV)-negative and P53 intact) and PLC/PRF/5 (HBV-positive and P53 mutated) cells. The expression of 27 genes in response to silibinin was evaluated by real-time RT-PCR. The MMP gelatinolytic assay and microculture tetrazolium test (MTT) were tested. Silibinin was capable of suppressing the transcriptional levels of ANGPT2, ATP6L, CAP2, CCR6, CCR7, CLDN-10, cortactin, CXCR4, GLI2, HK2, ID1, KIAA0101, mortalin, PAK1, RHOA, SPINK1, and STMN1 as well as the enzymatic activity of MMP-2 but promoted the transcripts of CREB3L3, DDX3X, and PROX1 in both cells. Some significant differences between the cells in response to silibinin were detected that might be related to the differences of the cells in terms of HBV infection and/or P53 mutation, suggesting the possible influence of silibinin on HCC through biological functions of these 2 prognostic factors. In conclusion, our findings suggest that silibinin could potentially function as a multitargeting antimetastatic agent and might provide new insights for HCC therapy particularly for HBV-related and/or P53-mutated HCCs.

Therapeutic efficacy of silibinin on human neuroblastoma cells: Akt and NF-κB expressions may play an important role in silibinin-induced response.

Neuroblastoma is the most common solid tumor in children. Current therapy modalities have resulted in little amelioration in the cure rate of neuroblsatoma and therefore, outlining biologically based therapies for neuroblastoma remains of main priority. This study was carried out to appraise the impeding effects of silibinin, a potent anti-cancer agent, on two different neuroblastoma cell lines, stromal SK-N-MC and neuroblastic SK-N-BE(2) cells. The microculture tetrazolium assay, gelatin zymography, colony formation assay, cell cycle distribution survey, apoptosis assay, and quantitative real-time reverse transcription-PCR were applied to evaluate the effects of silibinin on metabolic activity, gelatinolytic activity of MMP-2 and MMP-9, surviving potential, cell cycle, apoptosis, and expression pattern of the genes involved in cell survival and invasion of the two neuroblastoma cell lines. Treatment for 48 h inhibited metabolic activity and clonogenic potential of SK-N-MC cells in a dose-dependent manner. Silibinin also inhibited transcriptional levels of MMP-2, MMP-9, and uPAR, as markers of cell invasion, in SK-N-MC cells. Higher concentration of silibinin (75, 100 µM) suppressed enzymatic activity of MMP-2 in this cell line. No change in apoptosis and cell cycle was observed in neither of the cells after treatment with silibinin. On the other hand, silibinin highly decreased mRNA expression of Akt, and NF-κB1 and its regulators, IKK1 and IKK2 in SK-N-MC cell line. Comparison of transcriptional expression of Akt, and NF-κB1 in untreated stromal and neuroblastic cell lines shows that their basal transcriptional levels are much higher in SK-N-BE(2) cell line than that in SK-N-MC cells. It seems that SK-N-BE(2) cell line probably resists to silibinin through higher expression of Akt and probably NF-κB1. Collectively, our results demonstrated that silibinin highly inhibits the proliferative potentials of SK-N-MC cell line, whilst it had less inhibitory effect on SK-N-BE(2) cell line. Our results suggest that suppression of SK-N-MC cell line by silibinin may be through inhibition of Akt-mediated NF-κB1.

Apoptin Overexpression Efficiently Amplified Cytotoxic Effects of PI3K Inhibition Using BKM120 in Lymphoblastic Leukemia Cell Lines.

Purpose: Although the complex structure of acute lymphoblastic leukemia (ALL) and involvement of diverse pathways in its pathogenesis have put an obstacle in the way of efficient treatments, identification of strategies to manipulate the genome of neoplastic cells has made the treatment prospective more optimistic. Methods: To evaluate whether the transduction of apoptin __a gene encoding a protein that participates in the induction of apoptosis__ could reduce the survival of leukemic cells, we generated recombinant lentivirus expressing apoptin, and then, MTT assay, flow cytometric analysis of DNA content, western blotting, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were applied. Results: Transduction of apoptin into different leukemic cells was coupled with the reduction in the viability and proliferative capacity of the cells. Among all tested cell lines, Nalm-6 and C8166 were more sensitive to the anti-leukemic property of apoptin. Moreover, we found that the transduction of apoptin in the indicated cell lines not only induced G2/M cell cycle arrest but also induced apoptotic cell death by altering the balance between pro- and anti-apoptotic target genes. The efficacy of apoptin transduction was not limited to these findings, as we reported for the first time that the overexpression of this gene could potentiate the anti-leukemic property of pan PI3K inhibitor BKM120. Conclusion: The results of this study showed that the transduction of apoptin into lymphoblastic leukemia cell lines induced cytotoxic effects and enhanced therapeutic value of PI3K inhibition; however, further investigations are demanded to ascertain the safety and the efficacy of apoptin transduction in patients with ALL.

Anticancer Effects of ZnO/CNT@Fe3O4 in AML-Derived KG1 Cells: Shedding Light on Promising Potential of Metal Nanoparticles in Acute Leukemia.

Background: Therapeutic approaches for acute myeloid leukemia (AML) have remained largely unchanged for over 40 years and cytarabine and an anthracycline (e.g., daunorubicin) backbone is the main induction therapy for these patients. Resistance to chemotherapy is the major clinical challenge and contributes to short-term survival with a high rate of disease recurrence. Given the established efficacy of nanoparticles in cancer treatment, this study was designed to evaluate the anticancer property of our novel nanocomposite in the AML-derived KG1 cells. Materials and Methods: To assess the anti-leukemic effects of our nanocomposite on AML cells, we used MTT and trypan blue assays. Flow cytometric analysis and q-RT-PCR were also applied to evaluate the impact of nanocomposite on cell cycle and apoptosis. Results: Our results outlined that ZnO/CNT@Fe3O4 decreased viability and metabolic activity of KG1 cells through induction of G1 arrest by increasing the expression of p21 and p27 cyclin-dependent kinase inhibitors and decreasing c-Myc transcription. Moreover, ZnO/CNT@Fe3O4 markedly elevated the percentage of apoptotic cells which was coupled with a significant alteration of Bax and Bcl-2 expressions. Synergistic experiments showed that ZnO/CNT@Fe3O4 enhances the cytotoxic effects of Vincristine on KG1 cells. Conclusion: In conclusion, this study sheds light on the potent anti-leukemic effects of ZnO/CNT@Fe3O4 and provides evidence for the application of this agent in the treatment of acute myeloid leukemia.

Blockade of Nuclear Factor-Κb (NF-Κb) Pathway Using Bay 11-7082 Enhances Arsenic Trioxide-Induced Antiproliferative Activity in U87 Glioblastoma Cells.

Background: Glioblastoma (GBM), the most aggressive and common form of glioma, accounts for over 13,000 death per year in the United States which indicates the importance of developing novel strategies for the treatment of this fatal malignancy. Although Arsenic trioxide (ATO) hinders the growth and survival of GBM cells, the requirement of concentrations higher than 4 µM for triggering apoptotic cell death has questioned its safety profile. Since the NF-κB signaling pathway plays a crucial role in tumorigenesis and chemo-resistance, targeting this oncogenic pathway may sensitize GBM cells to lower concentrations of ATO. Methods: Anti-tumor effects of ATO as monotherapy and in combination with Bay 11-7082 were determined using MTT, crystal violet staining, Annexin V/PI staining and scratch assays. Quantitative reverse transcription-PCR (qRT-PCR) analysis was applied to elucidate the molecular mechanisms underlying the anti-tumor activity of this combination therapy. Results: Our results revealed that ATO and Bay 11-7082 synergistically inhibited the proliferation and survival of GBM cells. Also, it was revealed that NF-κB inhibition using Bay 11-7082 enhanced the inhibitory effects of ATO on migration of GBM cells via suppressing the expression of NF-κB target genes such as TWIST, MMP2, ICAM-1, and cathepsin B. Furthermore, combination treatment of GBM cells with ATO and Bay 11-7082 significantly induce apoptotic cell death coupled with downregulation of NF-κB anti-apoptotic target genes including Bcl-2 and IAP family members. Conclusion: Altogether, these findings suggest that combination therapy with ATO and Bay 11-7082 may be a promising strategy for the treatment of GBM.

The DNA Methylation in Neurological Diseases.

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.

Dual-specificity phosphatases: therapeutic targets in cancer therapy resistance.

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.