The Role of Protein Kinase B Signaling Pathway in Anti-Cancer Effect of Rolipram on Glioblastoma Multiforme: An In Vitro Study

ZL-n-91, a specific Phosphodiesterase-4 inhibitor, suppresses the growth of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that frequently develops resistance to chemotherapy. A new approach to treating TNBC is required to improve patient survival. Phosphodiesterase-4 (PDE4) is an enzyme that is predominantly involved in the modulation of intracellular signaling mediated by cAMP. Although the efficacy of PDE4 inhibitors in several human inflammatory diseases is well documented, their clinical utility has been limited by side effects, including nausea and emesis. Recently, PDE4 has been used as a potential therapeutic target for different cancer types. In the present study, we investigated the anticancer effects of a novel PDE4 inhibitor ZL-n-91 on TNBC and the underlying mechanism. We showed that ZL-n-91 inhibited the proliferation of TNBC cells, induced cell apoptosis, and caused cell cycle arrest. Western blot analysis showed that ZL-n-91 increased Bax level and reduced Bcl-2 expression. Furthermore, downregulation of the cell cycle-related proteins, such as CDK2, CDK4, cyclin D1, PCNA, p-RB, and ZL-n-91, significantly inhibited the transcription of DNA repair genes and triggered an intracellular DNA damage response. Moreover, ZL-n-91 prevented the growth of the transplanted MDA-MB-231 tumor xenograft in nude mice and increased the γ-H2AX expression. These data demonstrate the anticancer effects of ZL-n-91 on TNBC cells and suggest its potential use in anticancer therapy.

Preconditioning process for dermal tissue decellularization using electroporation with sonication

Decellularization to produce bioscaffolds composed of the extracellular matrix (ECM) uses enzymatic, chemical and physical methods to remove antigens and cellular components from tissues. Effective decellularization methods depend on the characteristics of tissues, and in particular, tissues with dense, complex structure and abundant lipid content are difficult to completely decellularize. Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues, which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization. In this study, decellularization of human dermal tissue was done by a combination of both chemical (0.05% trypsin-EDTA, 2% SDS and 1% Triton X-100) and physical methods (electroporation and sonication). After decellularization, the content of DNA remaining in the tissue was quantitatively confirmed, and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis, respectively. Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization, and conditions for electroporation and sonication without the use of detergents, unlike the methods performed in previous studies, were established to enable the complete decellularization of the skin tissue. The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties. Therefore, this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

Phosphodiesterase 4D Depletion/Inhibition Exerts Anti-Oncogenic Properties in Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Drug resistance is a serious problem in the treatment of HCC. Therefore, it is of high clinical impact to discover targeted therapies that may overcome drug-related resistance and improve the survival of patients affected by HCC. In the present study, we investigated the role of Isoform D of type 4 phosphodiesterase (PDE4D) in HCC development and progression. We found that PDE4D is over-expressed HCCs in vitro and in vivo and the depletion of the gene by silencing or the pharmacological inhibition of protein activity exerted anti-tumorigenic activities.

Abstract

Isoform D of type 4 phosphodiesterase (PDE4D) has recently been associated with several human cancer types with the exception of human hepatocellular carcinoma (HCC). Here we explored the role of PDE4D in HCC. We found that PDE4D gene/protein were over-expressed in different samples of human HCCs compared to normal livers. Accordingly, HCC cells showed higher PDE4D activity than non-tumorigenic cells, accompanied by over-expression of the PDE4D isoform. Silencing of PDE4D gene and pharmacological inhibition of protein activity by the specific inhibitor Gebr-7b reduced cell proliferation and increased apoptosis in HCC cells, with a decreased fraction of cells in S phase and a differential modulation of key regulators of cell cycle and apoptosis. PDE4D silencing/inhibition also affected the gene expression of several cancer-related genes, such as the pro-oncogenic insulin growth factor (IGF2), which is down-regulated. Finally, gene expression data, available in the CancerLivER data base, confirm that PDE4D over-expression in human HCCs correlated with an increased expression of IGF2, suggesting a new possible molecular network that requires further investigations. In conclusion, intracellular depletion/inhibition of PDE4D prevents the growth of HCC cells, displaying anti-oncogenic effects. PDE4D may thus represent a new biomarker for diagnosis and a potential adjuvant target for HCC therapy.

Novel cyanothiouracil and cyanothiocytosine derivatives as concentration-dependent selective inhibitors of U87MG glioblastomas: Adenosine receptor binding and potent PDE4 inhibition

Thiouracil and thiocytosine are important heterocyclic pharmacophores having pharmacological diversity. Antitumor and antiviral activity is commonly associated with thiouracil and thiocytosine derivatives, which are well known fragments for adenosine receptor affinity with many associated pharmacological properties. In this respect, 33 novel compounds have been synthesized in two groups: 24 thiouracil derivatives (4a-x) and 9 thiocytosine derivatives (5a-i). Antitumor activity of all the compounds was determined in the U87 MG glioblastoma cell line. Compound 5e showed an anti-proliferative IC₅₀ of 1.56 μM, which is slightly higher activity than cisplatin (1.67 μM). The 11 most active compounds showed no signficant binding to adenosine A₁, A_2A or A_2B receptors at 1 μM. Brain tumors express high amounts of phosphodiesterases. Compounds were tested for PDE4 inhibition, and 5e and 5f showed the best potency (5e: 3.42 μM; 5f: 0.97 μM). Remakably, those compounds were also the most active against U87MG. However, the compounds lacked a cytotoxic effect on the HEK293 healthy cell line, which encourages further investigation.

Phosphodiesterase-4 enzyme as a therapeutic target in neurological disorders

Phosphodiesterases (PDE) are a diverse family of enzymes (11 isoforms so far identified) responsible for the degradation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) which are involved in several cellular and biochemical functions. Phosphodiesterase 4 (PDE4) is the major isoform within this group and is highly expressed in the mammalian brain. An inverse association between PDE4 and cAMP levels is the key mechanism in various pathophysiological conditions like airway inflammatory diseases-chronic obstruction pulmonary disease (COPD), asthma, psoriasis, rheumatoid arthritis, and neurological disorders etc. In 2011, roflumilast, a PDE4 inhibitor (PDE4I) was approved for the treatment of COPD. Subsequently, other PDE4 inhibitors (PDE4Is) like apremilast and crisaborole were approved by the Food and Drug Administration (FDA) for psoriasis, atopic dermatitis etc. Due to the adverse effects like unbearable nausea and vomiting, dose intolerance and diarrhoea, PDE4 inhibitors have very less clinical compliance. Efforts are being made to develop allosteric modulation with high specificity to PDE4 isoforms having better efficacy and lesser adverse effects. Interestingly, repositioning PDE4Is towards neurological disorders including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS) and sleep disorders, is gaining attention. This review is an attempt to summarize the data on the effects of PDE4 overexpression in neurological disorders and the use of PDE4Is and newer allosteric modulators as therapeutic options. We have also compiled a list of on-going clinical trials on PDE4 inhibitors in neurological disorders.

Tenocyte-imprinted substrate: a topography-based inducer for tenogenic differentiation in adipose tissue-derived mesenchymal stem cells

Tendon tissue engineering based on stem cell differentiation has attracted a great deal of attention in recent years. Previous studies have examined the effect of cell-imprinted polydimethylsiloxane (PDMS) substrate on induction differentiation in stem cells. In this study, we used tenocyte morphology as a positive mold to create a tenocyte-imprinted substrate on PDMS. The morphology and topography of this tenocyte replica on PDMS was evaluated with scanning electron microscopy (SEM) and atomic force microscopy. The tenogenic differentiation induction capacity of the tenocyte replica in adipose tissue-derived mesenchymal stem cells (ADSCs) was then investigated and compared with other groups, including tissue replica (which was produced similarly to the tenocyte replica and was evaluated by SEM), decellularized tendon, and bone morphogenic protein (BMP)-12, as other potential inducers. This comparison gives us an estimate of the ability of tenocyte-imprinted PDMS (called cell replica in the present study) to induce differentiation compared to other inducers. For this reason, ADSCs were divided into five groups, including control, cell replica, tissue replica, decellularized tendon and BMP-12. ADSCs were seeded on each group separately and investigated by the real-time reverse transcription polymerase chain reaction (RT-PCR) technique after seven and 14 days. Our results showed that in spite of the higher effect of the growth factor on tenogenic differentiation, the cell replica can also induce tenocyte marker expression (scleraxis and tenomodulin) in ADSCs. Moreover, the tenogenic differentiation induction capacity of the cell replica was greater than tissue replica. Immunocytochemistry analysis revealed that ADSCs seeding on the cell replica for 14 days led to scleraxis and tenomodulin expression at the protein level. In addition, immunohistochemistry indicated that contrary to the promising results in vitro, there was little difference between ADSCs cultured on tenocyte-imprinted PDMS and untreated ADSCs. The results of such studies could lead to the production of inexpensive cell culture plates or biomaterials that can induce differentiation in stem cells without growth factors or other supplements.

Rolipram optimizes therapeutic effect of bevacizumab by enhancing proapoptotic, antiproliferative signals in a glioblastoma heterotopic model

The unstable response to bevacizumab is a big dilemma in the antiangiogenic therapy of high-grade glioma that appears to be linked to an increase in the post-treatment intratumor levels of hypoxia-inducible factor 1 α (HIF1α) and active AKT. Particularly, a selective phosphodiesterase IV (PDE4) inhibitor, rolipram is capable of inhibiting HIF1α and AKT in cancer cells. Here, the effect of bevacizumab alone and in presence of rolipram on therapeutic efficacy, intratumor hypoxia levels, angiogenesis, apoptosis and proliferation mechanisms were evaluated. BALB/c mice bearing C6 glioma were received bevacizumab and rolipram either alone or combined for 30 days (n = 11/group). At the last day of treatments, apoptosis, proliferation and microvessel density, in xenografts (3/group) were detected by TUNEL staining, Ki67 and CD31 markers, respectively. Relative expression of target proteins was measured using western blotting. Bevacizumab initially hindered the tumor progression but its antitumor effect was weakened later despite the vascular regression and apoptosis induction. Unpredictably, bevacizumab-treated tumors exhibited the highest cell proliferation coupled with PDE4A, HIF1α and AKT upregulation and p53 downregulation and reversed by co-treatment with rolipram. Unlike a similar antivascular pattern to bevacizumab, rolipram consistently led to a more tumor growth suppression and proapoptotic effect versus bevacizumab. Co-treatment maximally hampered the tumor progression and elongated survival along with the major vascular regression, hypoxia, apoptosis induction, p53 and caspase activities. In conclusion, superior and persistent therapeutic efficacy of co-treatment provides a new insight into antiangiogenic therapy of malignant gliomas, suggesting to be a potential substitute in selected patients.

Methylxanthines: Potential Therapeutic Agents for Glioblastoma

Glioblastoma (GBM) is the most common and aggressive primary brain tumor. Currently, treatment is ineffective and the median overall survival is 20.9 months. The poor prognosis of GBM is a consequence of several altered signaling pathways that favor the proliferation and survival of neoplastic cells. One of these pathways is the deregulation of phosphodiesterases (PDEs). These enzymes participate in the development of GBM and may have value as therapeutic targets to treat GBM. Methylxanthines (MXTs) such as caffeine, theophylline, and theobromine are PDE inhibitors and constitute a promising therapeutic anti-cancer agent against GBM. MTXs also regulate various cell processes such as proliferation, migration, cell death, and differentiation; these processes are related to cancer progression, making MXTs potential therapeutic agents in GBM.

Decellularized human amniotic membrane: From animal models to clinical trials

The efficacy of decellularized products for healing of acute and chronic wounds mostly relies on physical and chemical properties, processing methods and host response. Human Amniotic Membrane (HAM) is considered as an effective and highly used wound dressing in clinic. According to the proposed decellularization protocols for developing of HAM, we have compared different protocols to introduce the most efficient methods, which can be used as a functional dermal matrix. In this study, different methods of HAM decellularization were used to achieve an optimal process. After achievement of appropriate decellularized method in vitro the amniotic membrane were examined in term of animal in vivo study and human clinical trial. The results of in vitro and in vivo assay indicate that the HAMs which were prepared with peracetic acid (2 M) had a significantly different in term of GAGs quantification, DNA isolation and quantification, histological assessment, collagen analysis, Cell-Tissue Interaction Study and cytotoxicity (P < 0/05). Tissue samples treated with peracetic acid (2 M) were more acceptable than that of samples prepared with other protocols in terms of preserving natural components and structure and removing of cell fragments. The peracetic acid-processed HAM was further functionally evaluated through in vivo assessments that can further lead to tissue reconstruction within the human host.

Decellularization and preservation of human skin: A platform for tissue engineering and reconstructive surgery

A matrix derived from natural tissue functions as a highly biocompatible and versatile scaffold for tissue engineering applications. It can act as a supportive construct that provides a niche for colonization by host cells. In this work, we describe a cost-effective, reliable and reproducible protocol for decellularization and preservation of human skin as a potential soft tissue replacement. The decellularized human skin is achieved using purely chemical agents without any enzymatic steps. The suitability of the proposed method for the preservation of the extracellular matrix (ECM) structure and its main components and integrity were evaluated using histological and immunohistochemical analysis. Cryopreservation and final sterility were conducted using programmable freeze-drying and gamma irradiation. The architecture, basement membrane and 3D structure of ECM can be successfully preserved after decellularization. Our protocol was found to be appropriate to maintain key proteins such as collagen type I, III, IV and laminin in the structure of final scaffold. This protocol offers a novel platform for the preparation of a dermal substitute for potential clinical applications. STATEMENT OF SIGNIFICANCE: Clinical application of naturally-based scaffolds for verity of health problems obliges development of a reproducible and effective technology that does not change structural and compositional material properties during scaffold preparation and preservation. Lack of an effective protocol for the production of biological products using decellularization method is still remaining. This effort is directing to solve this challenge in order to accomplish the off-the -shelf availability of decellularized dermal scaffold in market for clinical application.

The Effect of Alpha-Tocopherol on Morphine Tolerance-induced Expression of c-fos Proto-oncogene from a Biotechnological Perspective

BACKGROUND

The increase of oxidant compounds is the most well-known reasons for the tolerance to the analgesic properties of Morphine. Additionally, the production of proxy-nitrite impairs receptors, proteins and enzymes involved in the signaling pathways of analgesia, apoptosis and necrosis. Also, we revised all patents relating to opioid tolerance control methods.

OBJECTIVE

The aim of this study was to assess the effects of Alpha-tocopherol as an anti-oxidant agent to reduce Morphine tolerance.

METHOD

Forty male rats randomly divided into four groups. 10 mg/kg of morphine was injected subcutaneously to create the desired level of tolerance. After modeling, 70 mg/kg Alpha- Tocopherol was injected intraperitoneal. Also, the hot plate recorded pain threshold alterations was used to evaluate the behavioral test. All tissue samples were extracted from the spinal cord, thalamus and frontal cortex for molecular and gene expression evaluations. Also, the effect of Alpha- Tocopherol on the apoptosis and necrosis parameters was analyzed using nissl staining and tunel test.

RESULTS

The time latency results showed that there were no significant differences in the different days in groups treated with Morphine plus Alpha-Tocopherol. However, our data highlighted that the pain threshold and their time latency in respond to it had substantially increased in comparison with the control group. Furthermore, we found that the Alpha-Tocopherol obviously decreased c-fos gene expression, especially in the spinal cord.

CONCLUSION

Thus, co-administration of Alpha-Tocopherol with Morphine can decrease the adverse effects of nitrite proxy, which is released due to repeated injections of Morphine.

Paths for Improving Bevacizumab Available in 2018: The ADZT Regimen for Better Glioblastoma Treatment

During glioblastoma treatment, the pharmaceutical monoclonal antibody to vascular endothelial growth factor A, bevacizumab, has improved the quality of life and delayed progression for several months, but has not (or only marginally) prolonged overall survival. In 2017, several dramatic research papers appeared that are crucial to our understanding of glioblastoma vis-a-vis the mode of action of bevacizumab. As a consequence of these papers, a new, potentially more effective treatment protocol can be built around bevacizumab. This is the ADZT regimen, where four old drugs are added to bevacizumab. These four drugs are apremilast, marketed to treat psoriasis, dapsone, marketed to treat Hansen’s disease, zonisamide, marketed to treat seizures, and telmisartan, marketed to treat hypertension. The ancillary attributes of each of these drugs have been shown to augment bevacizumab. This paper details the research data supporting this contention. Phase three testing of AZDT addition to bevacizumab is required to establish safety and effectiveness before general use.

Roflumilast enhances cisplatin-sensitivity and reverses cisplatin-resistance of ovarian cancer cells via cAMP/PKA/CREB-FtMt signalling axis

OBJECTIVE

We previously demonstrated the roflumilast inhibited cell proliferation and increased cell apoptosis in ovarian cancer. In this study, we aimed to investigate the roles of roflumilast in development of cisplatin (DDP)-sensitive and -resistant ovarian cancer.

METHODS

OVCAR3 and SKOV3 were selected and the corresponding DDP-resistant cells were constructed. Cell viability, proliferation, apoptosis, cycle were performed. Expression cAMP, PKA, CREB, phosphorylation of CREB and FtMt were detected. The roles of roflumilast in development of DDP-sensitive and -resistant ovarian cancer were confirmed by xenograft model.

RESULTS

Roflumilast + DDP inhibited cell proliferation, and induced cell apoptosis and G0/G1 arrest in OVCAR3 and SKOV3 cells, roflumilast induced expression of FtMt, the activity of cAMP and PKA and phosphorylation of CREB in ovarian cancer cells and the above-effect were inhibited by H89. Downregulation of CREB inhibited the roflumilast-increased DDP sensitivity of ovarian cancer cells, and the roflumilast-induced FtMt expression and phosphorylation of CREB. Also, roflumilast reversed cisplatin-resistance, and induced expression of FtMt and activation of cAMP/PKA/CREB in DDP-resistant ovarian cancer cells. Similarly, treated with H89 or downregulation of CREB inhibited the changes induced by roflumilast. In vivo, roflumilast inhibited the development of SKOV3 or SKOV3-DDP-R xenograft models.

CONCLUSIONS

Roflumilast enhanced DDP sensitivity and reversed the DDP resistance of ovarian cancer cells via activation of cAMP/PKA/CREB pathway and upregulation of the downstream FtMt expression, which has great promise in clinical treatment.

Inhibitors of phosphodiesterase as cancer therapeutics

Phosphodiesterases (PDEs) are a class of enzymes that hydrolyze cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) which is involved in many physiological processes including visual transduction, cell proliferation and differentiation, cell-cycle regulation, gene expression, inflammation, apoptosis, and metabolic function. PDEs are composed of 11 different families and each family contains different subtypes. The distribution, expression, regulation mode and sensitivity to inhibitors of each subtype are different, and they are involved in cancer, inflammation, asthma, depression, erectile dysfunction and other pathological processes of development. A large number of studies have shown that PDEs play an important role in the development of tumors by affecting the intracellular level of cAMP and/or cGMP and PDEs could become diagnostic markers or therapeutic targets. This review will give a brief overview of the expression and regulation of PDE families in the process of tumorigenesis and their anti-tumor inhibitors, which may guide the design of novel therapeutic drugs targeting PDEs for anticancer agent.