Anti-neoplastic effect of protein kinase CK2 inhibitor, 2-dimethylamino-4,5,6,7-tetrabromobenzimidazole (DMAT), on growth and hormonal activity of human adrenocortical carcinoma cell line (H295R) in vitro

CK2 inhibitor DMAT ameliorates spinal cord injury by increasing autophagy and inducing anti-inflammatory microglial polarization

Spinal cord injury (SCI) is a destructive and disabling nerve injury from which complete recovery has not yet been achieved due to complex pathology. Casein kinase II (CK2) is a pleiotropic serine/threonine protein kinase that plays an essential role in the nervous system. This study aimed to investigate the role of CK2 in SCI to understand the pathogenesis of SCI and explore new therapeutic methods. The SCI rat model of C5 unilateral clamp was established by modified clamp method in male adult SD rats. Then, CK2 inhibitor DMAT was used to treat SCI rats, and the behaviour, pathological changes in the spinal cord and microglial polarization were analysed. Additionally, the effects of DMAT on the polarization and autophagy of microglial BV-2 cells were investigated in vitro, and the effects of BV-2 polarization on spinal cord neuronal cells were analysed by Transwell coculture. Results showed that DMAT significantly increased the BBB score, improved histopathological injury, decreased the expression of inflammatory cytokines, and promoted M2 polarization of microglia in SCI rats. In vitro experiments further confirmed that DMAT could promote the polarization of BV-2 to the M2 type, promote autophagy, and reverse the LPS-induced decline in cell viability and increase in apoptosis of neuronal cells. The use of 3-MA confirmed that autophagy plays an important role in DMAT promoting M2 polarization of BV-2 to improve neuronal cell viability. In conclusion, CK2 inhibitor DMAT improved SCI by inducing anti-inflammatory polarization of microglia through autophagy and is a potential therapeutic target for SCI.

Antitumor activity of the protein kinase inhibitor 1-(β-D-2'-deoxyribofuranosyl)-4,5,6,7-tetrabromo- 1H-benzimidazole in breast cancer cell lines

Background

The protein kinases CK2 and PIM-1 are involved in cell proliferation and survival, the cell cycle, and drug resistance, and they are found overexpressed in virtually all types of human cancer, including breast cancer. In this study, we investigated the antitumor activity of a deoxynucleoside derivative, the protein kinase inhibitor compound 1-(β-D-2′-deoxyribofuranosyl)-4,5,6,7-tetrabromo-1H-benzimidazole (K164, also termed TDB), inter alia CK2 and PIM-1, on breast cancer cell lines (MDA-MB-231, MCF-7, and SK-BR-3).

Methods

An evaluation of the cytotoxic and proapoptotic effects, mitochondrial membrane potential (ΔΨm), and cell cycle progression was performed using an MTT assay, flow cytometry, and microscopic analysis. The Western blotting method was used to analyze the level of proteins important for the survival of breast cancer cells and proteins phosphorylated by the CK2 and PIM-1 kinases.

Results

The examined compound demonstrated the inhibition of cell viability in all the tested cell lines and apoptotic activity, especially in the MCF-7 and SK-BR-3 cells. Changes in the mitochondrial membrane potential (ΔΨm), cell cycle progression, and the level of the proteins studied were also observed.

Conclusions

The investigated CK2 and PIM-1 kinase inhibitor K164 is a promising compound that can be considered a potential agent in targeted therapy in selected types of breast cancer; therefore, further research is necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10156-8.

CK2 and protein kinases of the CK1 superfamily as targets for neurodegenerative disorders

Casein kinases are involved in a variety of signaling pathways, and also in inflammation, cancer, and neurological diseases. Therefore, they are regarded as potential therapeutic targets for drug design. Recent studies have highlighted the importance of the casein kinase 1 superfamily as well as protein kinase CK2 in the development of several neurodegenerative pathologies, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. CK1 kinases and their closely related tau tubulin kinases as well as CK2 are found to be overexpressed in the mammalian brain. Numerous substrates have been detected which play crucial roles in neuronal and synaptic network functions and activities. The development of new substances for the treatment of these pathologies is in high demand. The impact of these kinases in the progress of neurodegenerative disorders, their bona fide substrates, and numerous natural and synthetic compounds which are able to inhibit CK1, TTBK, and CK2 are discussed in this review.

Inhibiting CK2 among Promising Therapeutic Strategies for Gliomas and Several Other Neoplasms

In gliomas, casein kinase 2 (CK2) plays a dominant role in cell survival and tumour invasiveness and is upregulated in many brain tumours. Among CK2 inhibitors, benzimidazole and isothiourea derivatives hold a dominant position. While targeting glioma tumour cells, they show limited toxicity towards normal cells. Research in recent years has shown that these compounds can be suitable as components of combined therapies with hyperbaric oxygenation. Such a combination increases the susceptibility of glioma tumour cells to cell death via apoptosis. Moreover, researchers planning on using any other antiglioma investigational pharmaceutics may want to consider using these agents in combination with CK2 inhibitors. However, different compounds are not equally effective when in such combination. More research is needed to elucidate the mechanism of treatment and optimize the treatment regimen. In addition, the role of CK2 in gliomagenesis and maintenance seems to have been challenged recently, as some compounds structurally similar to CK2 inhibitors do not inhibit CK2 while still being effective at reducing glioma viability and invasion. Furthermore, some newly developed inhibitors specific for CK2 do not appear to have strong anticancer properties. Further experimental and clinical studies of these inhibitors and combined therapies are warranted.

Hydroxyurea-induced replication stress causes poly(ADP-ribose) polymerase-2 accumulation and changes its intranuclear location in root meristems of Vicia faba

Replication stress induced by 24 and 48h exposure to 2.5mM hydroxyurea (HU) increased the activity of poly(ADP-ribose) polymerase-2 (PARP-2; EC 2.4.2.30) in root meristem cells of Vicia faba. An increase in the number of PARP-2 foci was accompanied by their delocalization from peripheral areas to the interior of the nucleus. Our results indicate that the increase in PARP-2 was connected with an increase in S139-phosphorylated H2AX histones. The findings suggest the possible role of PARP-2 in replication stress. We also confirm that the intranuclear location of PARP-2 depends on the duration of HU-induced replication stress, confirming the role of PARP-2 as an indicator of stress intensity. Finally, we conclude that the more intense the HU-mediated replication stress, the greater the probability of PARP-2 activation or H2AXS139 phosphorylation, but also the greater the chance of increasing the efficiency of repair processes and a return to normal cell cycle progression.

Casein kinases as potential therapeutic targets

INTRODUCTION

The conventional term 'casein kinase' (CK) denotes three classes of kinases - CK1, CK2 and Golgi-CK (G-CK)/Fam20C (family with sequence similarity 20, member C) - sharing the ability to phoshorylate casein in vitro, but otherwise unrelated to each other. All CKs have been reported to be implicated in human diseases, and reviews individually dealing with the druggability of CK1 and CK2 are available. Our aim is to provide a comparative analysis of the three classes of CKs as therapeutic targets.

AREAS COVERED

CK2 is the CK for which implication in neoplasia is best documented, with the survival of cancer cells often relying on its overexpression. An ample variety of cell-permeable CK2 inhibitors have been developed, with a couple of these now in clinical trials. Isoform-specific CK1 inhibitors that are expected to play a beneficial role in oncology and neurodegeneration have been also developed. In contrast, the pathogenic potential of G-CK/Fam20C is caused by its loss of function. Activators of Fam20C, notably sphingolipids and their analogs, may prove beneficial in this respect.

EXPERT OPINION

Optimization of CK2 and CK1 inhibitors will prove useful to develop new therapeutic strategies for treating cancer and neurodegenerative disorders, while the design of potent activators of G-CK/Fam20C will provide a new tool in the fields of bio-mineralization and hypophosphatemic diseases.

Ultrastructural changes associated with the induction of premature chromosome condensation in Vicia faba root meristem cells

PCC induction is regulated by several signaling pathways, and all observed effects associated with PCC induction are strongly dependent on the mechanism of action of each PCC inducer used. Electron microscopic observations of cells with symptoms of premature chromosome condensation (PCC) showed that the interphase chromatin and mitotic chromosomes differed with respect to a chemical compound inducing PCC. Induction of this process under the influence of hydroxyurea and caffeine as well as hydroxyurea and sodium metavanadate led to a slight decrease in interphase chromatin condensation and the formation of chromosomes with a considerably loosened structure in comparison with the control. Incubation in the mixture of hydroxyurea and 2-aminopurine brought about clear chromatin dispersion in interphase and very strong mitotic chromosome condensation. Electron microscopic examinations also revealed the characteristic features of the structural organization of cytoplasm of Vicia faba root meristems, which seemed to be dependent on the type of the PCC inducer used. The presence of the following was observed: (i) large plastids filled with starch grains (caffeine), (ii) mitochondria and plastids of electron dense matrix with dilated invaginations of their internal membranes (2-aminopurine), and (iii) large mitochondria of electron clear matrix and plastids containing protein crystals in their interior (sodium metavanadate). Moreover, since caffeine causes either the most effective loosening of chromatin fibrils (within the prematurely condensed chromosomes) or induction of starch formation (in the plastids surrounding the nuclei), this may be a proof that demonstrates the existence of a link between physical accessibility to chromatin and the effectiveness of cellular signaling (e.g., phosphothreonine-connected).

Adhesion to type V collagen enhances staurosporine-induced apoptosis of adrenocortical cancer cells

Adrenocortical carcinoma (ACC) is a rare and aggressive tumor characterized by poor prognosis and resistance to conventional chemotherapy. Many chemotherapy agents act determining apoptosis, therefore, studying the responsiveness of ACC to apoptosis inducing molecules, can help to identify possible conditions to promote cancer cell death. Tumor progression is strictly related to the interaction between cancer cells and stroma; yet, extracellular matrix remodeling regulates tumor cell proliferation and apoptosis. At this purpose, we have studied staurosporine-induced apoptosis of ACC cell line H295R adherent to different extracellular matrix molecules. H295R cells grown on plastic showed a low responsiveness to staurosporine, with an apoptotic rate of 24 %, as compared to breast cancer MCF7 cells, with an apoptotic rate of 60 %. The adhesion of H295R cells to type V collagen induced a significant increase of apoptosis up to 52 %; this effect was inhibited by anti-integrin alpha2 antibody. At the same time, the adhesion of H295R cells on polylysine, matrigel, lamimin, fibronectin, and type I-III collagens didn't modify staurosporine-induced apoptosis. Staurosporine-treated H295R cells showed an increase of PARP cleavage and of annexin-V expression, when adherent to type V collagen. Yet, staurosporine induced Akt and Erk activation on H295R cells: the adhesion on type V collagen didn't modify Akt activation, while determined a dramatic inhibition of Erk activation. The described data demonstrate that the adhesion to type V collagen specifically increases the responsiveness of ACC cells to staurosporine-induced apoptosis and that this is probably obtained through the inhibition of Erk activation.

Influence of five potential anticancer drugs on wnt pathway and cell survival in human biliary tract cancer cells

BACKGROUND

The role of Wnt signalling in carcinogenesis suggests compounds targeting this pathway as potential anti-cancer drugs. Several studies report activation of Wnt signalling in biliary tract cancer (BTC) thus rendering Wnt inhibitory drugs as potential candidates for targeted therapy of this highly chemoresistant disease.

METHODS

In this study we analysed five compounds with suggested inhibitory effects on Wnt signalling (DMAT, FH535, myricetin, quercetin, and TBB) for their cytotoxic efficiency, mode of cell death, time- and cell line-dependent characteristics as well as their effects on Wnt pathway activity in nine different BTC cell lines.

RESULTS

Exposure of cancer cells to different concentrations of the compounds results in a clear dose-dependent reduction of viability for all drugs in the order FH535 > DMAT > TBB > myricetin > quercetin. The first three substances show high cytotoxicity in all tested cell lines, cause a direct cytotoxic effect by induction of apoptosis and inhibit pathway-specific signal transduction in a Wnt transcription factor reporter activity assay. Selected target genes such as growth-promoting cyclin D1 and the cell cycle progression inhibitor p27 are down- and up-regulated after treatment, respectively.

CONCLUSIONS

Taken together, these data demonstrate that the small molecular weight inhibitors DMAT, F535 and TBB have a considerable cytotoxic and possibly Wnt-specific effect on BTC cell lines in vitro. Further in vivo investigation of these drugs as well as of new Wnt inhibitors may provide a promising approach for targeted therapy of this difficult-to-treat tumour.

Nanoencapsulated anti-CK2 small molecule drug or siRNA specifically targets malignant cancer but not benign cells

CK2, a pleiotropic Ser/Thr kinase, is an important target for cancer therapy. We tested our novel tenfibgen-based nanocapsule for delivery of the inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) and an siRNA directed against both CK2α and α' catalytic subunits to prostate cancer cells. We present data on the TBG nanocapsule itself and on CK2 inhibition or downregulation in treated cells, including effects on Nuclear Factor-kappa B (NF-κB) p65. By direct comparison of two CK2-directed cargos, our data provide proof that the TBG encapsulation design for delivery of drugs specifically to cancer cells has strong potential for small molecule- and nucleic acid-based cancer therapy.