p53 causes butein‑mediated apoptosis of chronic myeloid leukemia cells

Discovery of Novel SIRT1/2 Inhibitors with Effective Cytotoxicity against Human Leukemia Cells

The sirtuin enzyme family members, SIRT1 and SIRT2, play both tumor-promoting and tumor-suppressing roles, depending on the context and experimental conditions. Compounds that inhibit either SIRT1 or SIRT2 show promising antitumor effects in several types of cancer models, both in vitro and in vivo. The simultaneous inhibition of SIRT1 and SIRT2 is helpful in treating cancer by completely blocking p53 deacetylation, leading to cell death. However, only a few SIRT1/2 dual inhibitors have been developed. Here, we report the discovery of a novel series of SIRT1/2 dual inhibitors via a rational drug design that involved virtual screening and a substructure search. Eleven of the derived compounds exhibited high inhibitory activities, with IC50 < 5 μM and high specificity for both SIRT1 and SIRT2. Compounds hsa55 and PS9 strongly induced apoptosis and showed antiproliferative effects against human leukemia cell lines, which could be due to their ability to increase of p53 and α-tubulin acetylation, as we observed in MOLM-13 cells. Therefore, the new scaffolds of these compounds and their efficacy in leukemia cell lines provide important clues for the further development of novel anti-leukemia drugs.

Bioactive Phytoconstituents and Their Therapeutic Potentials in the Treatment of Haematological Cancers: A Review

Haematological (blood) cancers are the cancers of the blood and lymphoid forming tissues which represents approximately 10% of all cancers. It has been reported that approximately 60% of all blood cancers are incurable. Despite substantial improvement in access to detection/diagnosis, chemotherapy and bone marrow transplantation, there is still high recurrence and unpredictable but clearly defined relapses indicating that effective therapies are still lacking. Over the past two decades, medicinal plants and their biologically active compounds are being used as potential remedies and alternative therapies for the treatment of cancer. This is due to their anti-oxidant, anti-inflammatory, anti-mutagenic, anti-angiogenic, anti-cancer activities and negligible side effects. These bioactive compounds have the capacity to reduce proliferation of haematological cancers via various mechanisms such as promoting apoptosis, transcription regulation, inhibition of signalling pathways, downregulating receptors and blocking cell cycle. This review study highlights the mechanistic and beneficial effects of nine bioactive compounds (quercetin, ursolic acid, fisetin, resveratrol, epigallocatechin gallate, curcumin, gambogic acid, butein and celastrol) as potential remedies for chemoprevention of haematological cancers. The study provides useful insights on the effectiveness of the use of bioactive compounds from plants for chemoprevention of haematological cancers.

Molecular mechanisms underlying chemopreventive potential of butein: Current trends and future perspectives

Despite extensive efforts, cancer is still often considered as an incurable disease and initiation of novel drug development programs is crucial to improve the prognosis and clinical outcome of patients. One of the major approaches in designing the novel cancer drugs has historically comprised studies of natural agents with diverse anticancer properties. As only a marginal part of natural compounds has been investigated, this approach still represents an attractive source of new potential antitumor molecules. In this review article, different anticancer effects of plant-derived chalcone, butein, are discussed, including its growth inhibitory action, proapoptotic, antiangiogenic and antimetastatic activities in a variety of cancer cells. The molecular mechanisms underlying these effects are presented in detail, revealing interactions of butein with multiple cellular targets (Bcl-2/Bax, caspases, STAT3, cyclins, NF-κB, COX-2, MMP-9, VEGF/R etc.) and regulation of a wide range of intracellular signal transduction pathways. These data altogether allow a good basis for initiating further in vivo studies as well as clinical trials. Along with the efforts to overcome low bioavailability issues generally characteristic to plant metabolites, butein can be considered as a potential lead compound for safe and more efficient cancer drugs in the future.

Flavonoid-Based Cancer Therapy: An Updated Review

As cancers are one of the most important causes of human morbidity and mortality worldwide, researchers try to discover novel compounds and therapeutic approaches to decrease survival of cancer cells, angiogenesis, proliferation and metastasis. In the last decade, use of special phytochemical compounds and flavonoids was reported to be an interesting and hopeful tactic in the field of cancer therapy. Flavonoids are natural polyphenols found in plant, fruits, vegetables, teas and medicinal herbs. Based on reports, over 10,000 flavonoids have been detected and categorized into several subclasses, including flavonols, anthocyanins, flavanones, flavones, isoflavones and chalcones. It seems that the anticancer effect of flavonoids is mainly due to their antioxidant and anti inflammatory activities and their potential to modulate molecular targets and signaling pathways involved in cell survival, proliferation, differentiation, migration, angiogenesis and hormone activities. The main aim of this review is to evaluate the relationship between flavonoids consumption and cancer risk, and discuss the anti-cancer effects of these natural compounds in human cancer cells. Hence, we tried to collect and revise important recent in vivo and in vitro researches about the most effective flavonoids and their main mechanisms of action in various types of cancer cells.

Molecular Mechanisms of Antiproliferative Effects of Natural Chalcones

Simple Summary

Despite the important progress in cancer treatment in the past decades, the mortality rates in some types of cancer have not significantly decreased. Therefore, the search for novel anticancer drugs has become a topic of great interest. Chalcones, precursors of flavonoid synthesis in plants, have been documented as natural compounds with pleiotropic biological effects including antiproliferative/anticancer activity. This article focuses on the knowledge on molecular mechanisms of antiproliferative action of chalcones and draws attention to this group of natural compounds that may be of importance in the treatment of cancer disease.

Abstract

Although great progress has been made in the treatment of cancer, the search for new promising molecules with antitumor activity is still one of the greatest challenges in the fight against cancer due to the increasing number of new cases each year. Chalcones (1,3-diphenyl-2-propen-1-one), the precursors of flavonoid synthesis in higher plants, possess a wide spectrum of biological activities including antimicrobial, anti-inflammatory, antioxidant, and anticancer. A plethora of molecular mechanisms of action have been documented, including induction of apoptosis, autophagy, or other types of cell death, cell cycle changes, and modulation of several signaling pathways associated with cell survival or death. In addition, blockade of several steps of angiogenesis and proteasome inhibition has also been documented. This review summarizes the basic molecular mechanisms related to the antiproliferative effects of chalcones, focusing on research articles from the years January 2015–February 2021.

Applying genome-wide CRISPR to identify known and novel genes and pathways that modulate formaldehyde toxicity

Formaldehyde (FA), a ubiquitous environmental pollutant, is classified as a Group I human carcinogen by the International Agency for Research on Cancer. Previously, we reported that FA induced hematotoxicity and chromosomal aneuploidy in exposed workers and toxicity in bone marrow and hematopoietic stem cells of experimental animals. Using functional toxicogenomic profiling in yeast, we identified genes and cellular processes modulating eukaryotic FA cytotoxicity. Although we validated some of these findings in yeast, many specific genes, pathways and mechanisms of action of FA in human cells are not known. In the current study, we applied genome-wide, loss-of-function CRISPR screening to identify modulators of FA toxicity in the human hematopoietic K562 cell line. We assessed the cellular genetic determinants of susceptibility and resistance to FA at 40, 100 and 150 μM (IC10, IC20 and IC60, respectively) at two time points, day 8 and day 20. We identified multiple candidate genes that increase sensitivity (e.g. ADH5, ESD and FANC family) or resistance (e.g. FASN and KDM6A) to FA when disrupted. Pathway analysis revealed a major role for the FA metabolism and Fanconi anemia pathway in FA tolerance, consistent with findings from previous studies. Additional network analyses revealed potential new roles for one-carbon metabolism, fatty acid synthesis and mTOR signaling in modulating FA toxicity. Validation of these novel findings will further enhance our understanding of FA toxicity in human cells. Our findings support the utility of CRISPR-based functional genomics screening of environmental chemicals.

Melanoma Cancer Immunotherapy Using PD-L1 siRNA and Imatinib Promotes Cancer-Immunity Cycle

PURPOSE

Cancer-Immunity Cycle is a cascade of anticancer immune responses in the body that continues and fights against the cancer expansion. The Cancer-Immunity Cycle is halted by tumor cell immunosuppression of host T cell through programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) interactions that induce the functional suppression of tumor-reactive cytotoxic T cells and actively promotes the tumorigenesis via the mTOR signaling pathway.

METHODS

Here, we demonstrated that this Cycle could be enhanced by the synergistic knock down of PD-L1 through co-delivery of siRNA-PD-L1 (siPD-L1) and imatinib (IMT) in a liposomal nanoparticle.

RESULTS

The siPDIN effectively downregulated the protein expressions of PD-L1 and significantly knocked down the expression of p-S6k protein at in vitro and in vivo conditions which inhibited tumorigenic mTOR pathway. The combination-based siPDIN exhibited a significantly higher cytotoxic effect compared to that of individual anticancer agents. B16F10 cells treated with siPDIN exhibited a significantly higher cancer cell apoptosis (~60%) compared to cocktail combination of siRNA+IMT (~35%) analyzed by flow cytometer. Importantly, siPDIN significantly delayed the tumor growth with significantly lower tumor-specific growth rate than the animals treated with individual free IMT or siRNA. siPDIN produced a 3-fold higher IFN-γ compared to control in DLNs and 4-fold higher IFN-γ in spleens.

CONCLUSION

Overall, results revealed that the tumors treated with siPDIN restored the immunity of CTLs by potentially inhibiting the immune checkpoint interactions, suppressed the mTOR signaling pathway and exhibited an enhanced anticancer efficacy in melanoma.

Quercetin Promotes Cell Cycle Arrest and Apoptosis and Attenuates the Proliferation of Human Chronic Myeloid Leukemia Cell Line-K562 Through Interaction with HSPs (70 and 90), MAT2A and FOXM1

BACKGROUND

Chronic Myeloid Leukaemia (CML) starts in certain blood-forming cells of the bone marrow when cells acquire Philadelphia chromosome. Nowadays, scientists attempt to find novel and safe therapeutic agents and approaches for CML therapy using Tyrosine Kinase Inhibitors (TKIs), CML conventional treatment agents, has some restrictions and also adverse effects. Recently, it has been proposed that phytochemicals, such as flavonoids due to their low side effects and notable safety have the potential to be used for CML therapy.

MATERIALS AND METHODS

K-562 cells were exposed with three concentrations of the querectin (10, 40 and 80µM) for 12, 24 and 48 hours. After that, these cells apoptosis rate was estimated using Annexin-V/PI staining and flowcytometry analysis, and their proliferation rate was evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT). Finally, the expression of the 70 and 90 kilodalton heat shock proteins (HSP70 and 90), methionine adenosyltransferase 2A (MAT2A), Forkhead box protein M1 (FOXM1), caspase-3 and -8, Bcl-X(L) and Bax involved in leukemic cells survival and proliferation was assessed using Real-Time PCR within 12, 24 and 48 hours after exposure with quercetin 40 and 80µM.

RESULTS

Considering consequences, querecetin induced apoptosis in K-562 cells, and also abrogated these cells proliferation. On the other hand, RT-PCR results showed a reduction in some of the candidate genes expression, especially HSP70, Bcl-X(L) and FOXM1, when cells were treated with quercetin 40 and 80µM. Also, Bax, caspase-3 and caspase-8 expression was significantly improved in K-562 cells upon quercetin exposure.

CONCLUSION

We concluded that CML therapy by querecetin due to its anti-proliferative and anti-survival potentials could lead to the promising therapeutic outcome through targeting major survival and proliferation involved genes expression.

Small-molecule MDM2 inhibitor LQFM030-induced apoptosis in p53-null K562 chronic myeloid leukemia cells

Our group designed and synthesized the N-phenyl-piperazine LQFM030 [1-(4-((1-(4-chlorophenyl)-1H-pyrazol-4-yl)methyl) piperazin-1-yl) ethanone], a small molecule derived from molecular simplification of the Nutlin-1, an inhibitor of the human homologue of murine double minute 2 (MDM2) protein that is expressed in several types of cancer. To better investigate the effects of LQFM030 regarding the p53 mutation status, this study investigated the antiproliferative activity of LQFM030 against the p53-null K562 leukemia cells as well as the cell death pathways involved. In addition, the effects of LQFM030 on the levels of the p53/MDM2 complex were also carried out using 3T3 cells as a p53 wild-type model. Our data suggest that LQFM030 triggered apoptosis in K562 cells via different mechanisms including cell cycle arrest, caspase activation, reduction of mitochondrial activity, decrease in MDM2 expression, and transcriptional modulation of MDMX, p73, MYC, and NF-ĸB. Additionally, it promoted effects in p53/MDM2 binding in p53 wild-type 3T3 cells. Therefore, LQFM030 has antiproliferative effects in cancer cells by a p53 mutation status-independent manner with different signaling pathways. These findings open new perspectives to the treatment of leukemic cells considering the resistance development associated with cancer treatment with conventional cytotoxic drugs.

Arsenic sulfide nanoformulation induces erythroid differentiation in chronic myeloid leukemia cells through degradation of BCR-ABL

Background

Chronic myeloid leukemia (CML) is a myeloproliferative disorder due to the existence of BCR-ABL fusion protein that allows the cells to keep proliferating uncontrollably. Although tyrosine kinase inhibitors can inhibit the activity of BCR-ABL fusion protein to trigger the cells apoptosis, drug resistance or intolerance exists in part of CML patients. Arsenic sulfide in its raw form (r-As₄S₄) can be orally administrated and certain therapeutic effects have been found out in the treatment of hematologic malignancies through inducing cell apoptosis.

Methods

In this work, a water-dissolvable arsenic sulfide nanoformualtion (ee-As₄S₄) composed of As₄S₄ particulates with 470 nm in diameter and encapsulated by a kind of hydrophilic polymer was fabricated and applied to the CML cell line K562, K562/AO2 and primary cells from the bone marrow of CML patients.

Results

Results showed that instead of inhibiting the activity of BCR-ABL, ee-As₄S₄ induced direct degradation of BCR-ABL in K562 cells within 6 hr incubation, followed by the occurrence of erythroid differentiation in K562 after 72 hr incubation, evidenced by the significantly upregulated CD235a and benzidine staining, which was not detectable with r-As₄S₄. The ee-As₄S₄-induced erythroid differentiation was also observed in K562/AO2 cells and bone marrow mononuclear cells of CML patients. Mechanistic studies indicated that ee-As₄S₄ induced autophagy by downregulating the level of intracellular ROS and hypoxia-inducible factor-1α significantly, which led to the subsequent degradation of BCR-ABL. When the concentration was increased, ee-As₄S₄ induced much more significant apoptosis and cell cycle arrest than r-As₄S₄, and the cytotoxicity of the former was about 178 times of the latter.

Conclusion

ee-As₄S₄ was capable of inducing significant erythroid differentiation of CML cells by inducing the direct degradation of BCR-ABL; the new effect could improve hematopoietic function of CML patients as well as inhibit the leukemic cell proliferation.

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Two novel 1,4‑naphthoquinone derivatives induce human gastric cancer cell apoptosis and cell cycle arrest by regulating reactive oxygen species‑mediated MAPK/Akt/STAT3 signaling pathways

1,4-Naphthoquinone derivatives have superior anticancer effects, but their use has been severely limited in clinical practice due to adverse side effects. To reduce the side effects and extend the anticancer effects of 1,4-naphthoquinone derivatives, 2-(butane-1-sulfinyl)-1,4-naphthoquinone (BQ) and 2-(octane-1-sulfinyl)-1,4-naphthoquinone (OQ) were synthesized, and their anticancer activities were investigated. The anti-proliferation effects, determined by MTT assays, showed that BQ and OQ significantly inhibited the viability of gastric cancer cells and had no significant cytotoxic effect on normal cell lines. The apoptotic effect was determined by flow cytometry, and the results showed that BQ and OQ induced cell apoptosis by regulating the mitochondrial pathway and cell cycle arrest at the G2/M phase via inhibition of the Akt signaling pathway in AGS cells. Furthermore, BQ and OQ significantly increased the levels of reactive oxygen species (ROS) and this effect was blocked by the ROS scavenger NAC in AGS cells. BQ and OQ induced apoptosis by upregulating the protein expression of p38 and JNK and downregulating the levels of ERK and STAT3. Furthermore, expression levels of these proteins were also blocked after NAC treatment. These results demonstrated that BQ and OQ induced apoptosis and cell cycle arrest at the G2/M phase in AGS cells by stimulating ROS generation, which caused subsequent activation of MAPK, Akt and STAT3 signaling pathways. Thus, BQ and OQ may serve as potential therapeutic agents for the treatment of human gastric cancer.

Leukemia therapy by flavonoids: Future and involved mechanisms

Flavonoids are a varied family of phytonutrients (plant chemicals) usually are detected in fruits and vegetables. In this big family, there exist more than 10,000 members that is separated into six chief subtypes: isoflavonols, flavonoenes, flavones, flavonols, anthocyanins, and chalcones. The natural compounds, such as fruits, have visible positive effects in regulating of survival involved signaling pathways that performance as the regulator of cell survival, growth, and proliferation. Researchers have established that commonly consumption up flavonoids decreases incidence and development risk of certain cancers, especially leukemia. Flavonoids have been able to induce apoptosis and stimulate cell cycle arrest in cancer cells via different pathways. Similarly, they have antiangiogenesis and antimetastasis capability, which were shown in wide ranges of cancer cells, particularly, leukemia. It seems that flavonoid because of their widespread approval, evident safety and low rate of side effects, have hopeful anticarcinogenic potential for leukemia therapy. Based on the last decade reports, the most important acting mechanisms of these natural compounds in leukemia cells are stimulating of apoptosis pathways by upregulation of caspase 3, 8, 9 and poly ADP-ribose polymerase (PARP) and proapoptotic proteins, particularly Bax activation. As well, they can induce cell cycle arrest in target cells not only via increasing of activated levels of p21 and p53 but also by inhibition of cyclins and cyclin-dependent kinases. Furthermore, attenuation of neclear factor-κB and signal transducer and activator of transcription 3 activation, suppression of signaling pathway and downregulation of intracellular antiapoptotic proteins are other significant antileukemic function mechanism of flavonoids. Overall, it appears that flavonoids are promising and effective compounds in the field of leukemia therapy. In this review, we tried to accumulate and revise most promising flavonoids and finally declared their major working mechanisms in leukemia cells.

Butein activates p53 in hepatocellular carcinoma cells via blocking MDM2-mediated ubiquitination

Introduction

In this study, we aimed to investigate the effect of butein on p53 in hepatocellular carcinoma (HCC) cells and the related molecular mechanisms by which p53 was activated.

Methods

MTS assay and clonogenic survival assay were used to examine the antitumor activity of butein in vitro. Reporter gene assay was adopted to evaluate p53 transcriptional activity. Flow cytometry and western blotting were performed to study apoptosis induction and protein expression respectively. Xenograft model was applied to determine the in vivo efficacy and the expression of p53 in tumor tissue was detected by immunohistochemistry.

Results

HCC cell proliferation and clonogenic survival were significantly inhibited after butein treatment. With the activation of cleaved-PARP and capsase-3, butein induced apoptosis in HCC cells in a dose-dependent manner. The transcriptional activity of p53 was substantially promoted by butein, and the expression of p53-targeted gene was increased accordingly. Mechanism studies demonstrated that the interaction between MDM2 and p53 was blocked by butein and MDM2-mediated p53 ubiquitination was substantially decreased. Short-hairpin RNA experiment results showed that the sensitivity of HCC cells to butein was substantially impaired after p53 was knocked down and butein-induced apoptosis was dramatically decreased. In vivo experiments validated substantial antitumor efficacy of butein against HepG2 xenograft growth, and the expression of p53 in butein-treated tumor tissue was significantly increased.

Conclusion

Butein demonstrated potent antitumor activities in HCC by activating p53, and butein or its analogs had therapeutic potential for HCC management.

p53 Gene (NY-CO-13) Levels in Patients with Chronic Myeloid Leukemia: The Role of Imatinib and Nilotinib

The p53 gene is also known as tumor suppressor p53. The main functions of the p53 gene are an anticancer effect and cellular genomic stability via various pathways including activation of DNA repair, induction of apoptosis, and arresting of cell growth at the G1/S phase. Normally, the p53 gene is inactivated by mouse double minute 2 proteins (mdm2), but it is activated in chronic myeloid leukemia (CML). Tyrosine kinase inhibitors are effective chemotherapeutic agents in the management of CML. The purpose of the present study was to evaluate the differential effect of imatinib and nilotinib on p53 gene serum levels in patients with CML. A total number of 60 patients with chronic myeloid leukemia with ages ranging from 47 to 59 years were recruited from the Iraqi Hematology Center. They started with tyrosine kinase inhibitors as first-line chemotherapy. They were divided into two groups—Group A, 29 patients treated with imatinib and Group B, 31 patients treated with nilotinib—and compared with 28 healthy subjects for evaluation p53 serum levels regarding the selective effect of either imatinib or nilotinib. There were significantly (p < 0.01) high p53 gene serum levels in patients with CML (2.135 ± 1.44 ng/mL) compared to the control (0.142 ± 0.11 ng/mL). Patients with CML that were treated with either imatinib or nilotinib showed insignificant differences in most of the hematological profile (p > 0.05) whereas, p53 serum levels were high (3.22 ± 1.99 ng/mL) in nilotinib-treated patients and relatively low (1.18 ± 0.19 ng/mL) in imatinib-treated patients (p = 0.0001). Conclusions: Nilotinib is more effective than imatinib in raising p53 serum levels in patients with chronic myeloid leukemia.

Antitumor Effects of Blocking Protein Neddylation in T315I-BCR-ABL Leukemia Cells and Leukemia Stem Cells

Imatinib revolutionized the treatment of chronic myeloid leukemia (CML), but drug resistance and disease recurrence remain a challenge. In this study, we suggest a novel strategy based on blocking protein neddylation to address BCR-ABL point mutations and leukemia stem cells (LSC) that lie at the root of imatinib-resistant recurrences. On the basis of the finding that the NEDD8-activating enzyme subunit NAE1 is overexpressed in CML cells, we hypothesized that the function of certain neddylation-dependent protein substrates might be targeted to therapeutic ends in imatinib-resistant CML cells and LSCs. In support of this hypothesis, we demonstrated that the NAE1 inhibitor MLN4924 induced G₂-M-phase arrest and apoptosis in bulk CML cells with wild-type p53, regardless of their T315I mutation status in BCR-ABL. Moreover, MLN4924 inhibited the survival and self-renewal of primary human CML CD34⁺ cells and LSCs in CML-bearing mice via accumulation of p27^kip1 in the nucleus. Notably, p27^kip1 silencing attenuated the suppressive effect of MLN4924 on the maintenance of LSCs in CML-bearing mice. Taken together, our findings offer a preclinical proof of concept for targeting protein neddylation as a novel therapeutic strategy to override mutational and LSC-derived imatinib resistance in CML.Significance: These findings highlight a mediator of protein neddylation, a type of protein turnover mechanism, as a viable therapeutic target against imatinib-resistant forms of chronic myelogenous leukemia. Cancer Res; 78(6); 1522-36. ©2018 AACR.

Semi-synthesis, structural modification and biological evaluation of 5-arylbenzofuran neolignans

5-Arylbenzofuran neolignans, a newfound class of natural products, were semi-synthesized, and a series of derivatives were designed, synthesized and evaluated for cytotoxicity.

Oridonin increases anticancer effects of lentinan in HepG2 human hepatoblastoma cells

The aim of the present study was to investigate whether oridonin is able to increase the effects of lentinan (LNT) in HepG2 human hepatoblastoma cells by MTT, flow cytometry, reverse transcription-quantitative polymerase chain reaction and western blot analysis. The in vitro results demonstrated that 20 µg/ml of oridonin was a nontoxic concentration for L02 normal liver cells and HepG2 liver cancer cells. Furthermore, treatment with 0-200 µg/ml LNT was only able to decrease the viability of HepG2 liver cancer cells. The growth inhibitory rate of the LNT-L (100 µg/ml) treatment group was 20.7% and the rate of the LNT-H (200 µg/ml) treatment group was 54.8%. Notably, the growth inhibitory rate of the oridonin + LNT-H group was 84.3%. The highest percentage of apoptotic cells was observed in the oridonin + LNT-H group (20 µg/ml oridonin and 200 µg/ml LNT). The percentage of apoptotic cells in the oridonin + LNT-H group was significantly different from the percentage of apoptotic cells in the LNT-H (26.1%) and the LNT-L (16.8%) groups. Treatment with LNT produced an increase in caspase-3, caspase-9, Bcl-2-like protein 4, p53, p21, nuclear factor κB inhibitor-α mRNA and protein expression and a decrease in B-cell lymphoma 2 and nuclear factor-κB expression in HepG2 cells compared with untreated control cells. Treatment with a combination of oridonin and LNT-H induced a further increase in expression with the biggest differences in expression observed between the oridonin + LNT-H group and control. It was observed that treatment with oridonin was able to increase the anticancer effects of LNT in HepG2 cells. Therefore, oridonin may be used to sensitize cells to LNT.

Quinalizarin exerts an anti-tumour effect on lung cancer A549 cells by modulating the Akt, MAPK, STAT3 and p53 signalling pathways

Quinalizarin may be a potential chemical agent for cancer therapy, as it exerts anti‑tumour effects against a variety of different types of cancer. However, the underlying regulatory mechanism and signalling pathways of quinalizarin in lung cancer cells remains unknown. The present study sought to investigate the effects of quinalizarin on proliferation, apoptosis and reactive oxygen species (ROS) generation in lung cancer. MTT assays were used to evaluate the effects of quinalizarin on the viability of lung cancer A549, NCI‑H460 and NCI‑H23 cells. Flow cytometry was employed to evaluate the effects of quinalizarin on the cell cycle, apoptosis and ROS generation in A549 cells. Western blotting was performed to detect cell cycle and apoptosis‑associated protein expression levels in A549 cells. Quinalizarin inhibited A549, NCI‑H460 and NCI‑H23 cell proliferation and induced A549 cell cycle arrest at the G0/G1 phase. Quinalizarin induced apoptosis by upregulating the expression of B‑cell lymphoma 2 (Bcl‑2)‑associated agonist of cell death, cleaved‑caspase‑3 and cleaved‑poly (adenosine diphosphate‑ribose) polymerase, and downregulating the expression of Bcl‑2. Furthermore, quinalizarin activated mitogen‑activated protein kinase (MAPK) and p53, and inhibited the protein kinase B and signal transducer and activator of transcription‑3 (STAT3) signalling pathways. In addition, quinalizarin increased ROS generation. The ROS scavenger N‑acetyl‑L‑cysteine restored quinalizarin‑induced cell apoptosis, and inactivated the MAPK and STAT3 signalling pathways. The results of the present study demonstrated that quinalizarin induces G0/G1 phase cell cycle arrest and apoptosis via ROS mediated‑MAPK and STAT3 signalling pathways.

Persistent STAT5-mediated ROS production and involvement of aberrant p53 apoptotic signaling in the resistance of chronic myeloid leukemia to imatinib

The persistent activation of signal transducer and activator of transcription 5 (STAT5) may principally be attributed to breakpoint cluster region (BCR)-Abelson murine leukemia viral oncogene homolog 1 (ABL1), and have multi-faceted effects in the development of chronic myeloid leukemia (CML). The p53 protein network regulates important mechanisms in DNA damage repair, cell cycle regulation/checkpoints, and cell senescence and apoptosis, as demonstrated by its ability to positively regulate the expression of various pro-apoptotic genes, including B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax). In the present study, it was observed that the mRNA levels of STAT5A and STAT5B were upregulated in patients with imatinib-resistant CML and in the imatinib-resistant K562/G CML cell line. In addition, increased expression of STAT5 was observed in the BCR-ABL1 mutation group, compared with that in the non-BCR-ABL1 mutation group, regardless of patient imatinib resistance state. Elevated levels of reactive oxygen species (ROS) and DNA double-strand breaks were identified in K562/G cells using flow cytometric and phosphorylated H2AX (γ-H2AX) foci immunofluorescence assays, respectively, compared with the imatinib-sensitive K562 cells. The levels of intracellular ROS and γ-H2AX were decreased by the ROS scavenger (N-acetylcysteine), and ROS levels were also markedly reduced by STAT5 inhibitor (SH-4-54). In addition, imatinib significantly inhibited the proliferation of K562 and K562/G cells, with half maximal inhibitory concentration values of 0.17±0.07 and 14.78±0.43 µM, respectively, and the levels of apoptosis were significantly different between K562 and K562/G cells following treatment with imatinib. The mRNA and protein levels of STAT5 and mouse double minute 2 homolog (MDM2) were upregulated, whereas those of Bax were downregulated in K562/G cells, as determined using western blot analysis. Additionally, although the two cell lines exhibited relatively low protein expression levels of p53, lower levels of p53 and TPp53BP1 transcripts were detected in the K562/G cells. Taken together, these findings suggest that the resistance of CML to the tyrosine kinase inhibitor, imatinib, may be associated with persistent STAT5-mediated ROS production, and the abnormality of the p53 pathway.

Oridonin enhances in vitro anticancer effects of lentinan in SMMC-7721 human hepatoma cells through apoptotic genes

The aim of the present study was to determine the ability of oridonin to enhance the anticancer activity of lentinan (LNT) in SMMC-7721 human hepatoma cells in vitro by using various techniques, including MTT, flow cytometry, quantitative PCR and western blot assays. The results demonstrated that 20 µg/ml was a non-toxic concentration of oridonin for L02 normal liver cells and SMMC-7721 cells, while 0-200 µg/ml of LNT only had anti-proliferative effects on SMMC-7721 cells. LNT at 100 and 200 µg/ml inhibited the growth of SMMC-7721 cells by 22.8 and 60.0%, respectively, and after addition of 20 µg/ml oridonin, the inhibitory rate of 100 and 200 µg/ml LNT was increased to 47.2 and 80.7%, respectively. Oridonin (20 µg/ml) + LNT (200 µg/ml)-treated SMMC-7721 cells showed the highest apoptotic rate, which was 40.5±2.5%, which was higher than that of cells treated with LNT only. LNT raised the mRNA and protein expression of caspase-3, -8 and -9 as well as B-cell lymphoma 2 (Bcl-2)-associated X protein, p53 and p21, while reducing the expression of Bcl-2, Bcl extra large protein, epidermal growth factor (EGF) and EGF receptor expression in SMMC-7721 cells as compared to that in control cells. Treatment with 20 µg/ml oridonin and 200 µg/ml LNT increased these changes of gene expression. From the obtained results, it may be concluded that oridonin raised the in vitro anti-cancer effects of LNT in SMMC-7721 cells. Oridonin may also be used as a sensitizing agent to increase the anticancer activity of LNT in vivo.

Butein inhibits NF-κB, AP-1 and Akt activation in adult T-cell leukemia/lymphoma

Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma (ATLL) but there is no effective treatment for HTLV-1-associated diseases. Herein, we determined the effect of butein, a bioactive plant polyphenol, on cell growth, apoptosis and signaling pathways in HTLV-1-infected T-cell lines and on tumor growth in SCID mice. Treatment with butein caused a decrease in viability of HTLV-1-infected T-cell lines. T cells cultured with butein showed obvious apoptosis morphology, and cleavage of poly(ADP-ribose) polymerase with activation of caspase-3, -8 and -9. Pretreatment of cells with caspase inhibitor partially blocked butein-induced inhibition of cell viability. Butein also resulted in cell cycle arrest at G1 phase. Butein markedly downregulated the protein expression levels of CDK4, CDK6, cyclin D1, cyclin D2, cyclin E, survivin, XIAP, c-IAP2 and phospho-pRb. Butein also inhibited i) total and phospho-protein levels of IκB kinase (IKK)α and IKKβ, ii) degradation and phosphorylation of IκBα, iii) JunB and JunD, iv) total and phospho-protein levels of Akt, v) phosphorylation of RelA, vi) heat shock protein 90, and vii) DNA-binding activity of NF-κB and AP-1. In mice harboring ATLL xenograft tumors, butein caused a significant inhibition of tumor growth and reduced serum levels of soluble interleukin-2 receptor α chain and soluble cluster of differentiation 30. Considered together, the results indicated that butein has antiproliferative and proapoptotic properties through the suppression of NF-κB, AP-1 and Akt signaling in HTLV-1-infected T cells, both in vitro and in vivo, suggesting its therapeutic potential against HTLV-1-associated diseases including ATLL.

Butein in health and disease: A comprehensive review

BACKGROUND

The risk of suffering from many chronic diseases seems to have made no improvement despite the advancement in medications available in the modern world. Moreover, the use of synthetic chemicals as medications has proved to worsen the scenario due to the various adverse side effects associated with them.

PURPOSE

Extensive research on natural medicines provides ample evidence on the safety and efficacy of phytochemicals and nutraceuticals against diverse chronic ailments. Therefore, it is advisable to use natural products in the management of such diseases. This article aims to present a comprehensive and critical review of known pharmacological and biological effects of butein, an important chalcone polyphenol first isolated from Rhus verniciflua Stokes, implicated in the prevention and treatment of various chronic disease conditions.

METHODS

An extensive literature search was conducted using PubMed, ScienceDirect, Scopus and Web of Science^TM core collections using key words followed by evaluation of the bibliographies of relevant articles.

RESULTS

Butein has been preclinically proven to be effective against several chronic diseases because it possesses a wide range of biological properties, including antioxidant, anti-inflammatory, anticancer, antidiabetic, hypotensive and neuroprotective effects. Furthermore, it has been shown to affect multiple molecular targets, including the master transcription factor nuclear factor-κB and its downstream molecules. Moreover, since it acts on multiple pathways, the chances of non-responsiveness and resistance development is reduced, supporting the use of butein as a preferred treatment option.

CONCLUSION

Based on numerous preclinical studies, butein shows significant therapeutic potential against various diseases. Nevertheless, well-designed clinical studies are urgently needed to validate the preclinical findings.