Mechanism Of Cell Cycle Arrest Research Articles

RETRACTION: Identification of Nrf2/STAT3 Axis in Induction of Apoptosis Through Sub-G1 Cell Cycle Arrest Mechanism in HT-29 Colon Cancer Cells.

I. Tajmohammadi, J. Mohammadian, M. Sabzichi, S. Mahmuodi, M. Ramezani, M. Aghajani, and F. Ramezani, "Identification of Nrf2/STAT3 Axis in Induction of Apoptosis Through Sub-G1 Cell Cycle Arrest Mechanism in HT-29 Colon Cancer Cells," Journal of Cellular Biochemistry 120, no. 8 (2019): 14035-14043, https://doi.org/10.1002/jcb.28678. The above article, published online on 16 April 2019 in Wiley Online Library (wileyonlinelibrary.com) has been retracted by agreement between the journal Editor-in-Chief, Christian Behl; and Wiley Periodicals, LLC. The retraction has been agreed due to concerns raised by a third party on the data presented in the article. Specifically, some image elements in Figure 4, where found to have been published elsewhere in a different scientific context. The authors did not provide a satisfactory explanation to address the concerns. For these reasons, the editors have lost trust in the accuracy and integrity of the full body of data presented in the article and consider its conclusions invalid. All authors have been informed of the decision of retraction. The corresponding author Fatemeh Ramezani, first author Issa Tajmohammadi, and Coauthor Mehdi Sabzichi disagree with the decision of retraction. Coauthor Marjan Aghajani has stated that she did not directly participate in the experiments conducted for the study, and that her role was limited to manuscript editing and language polishing; she neither agreed nor disagreed with the decision of retraction. No confirmation was obtained by the remaining co-authors.

Mutant P53 modulation by cryptolepine through cell cycle arrest and apoptosis in triple negative breast cancer

BackgroundTriple Negative Breast cancer is an aggressive breast cancer subtype. It has a more aggressive clinical course, an earlier age of onset, a larger propensity for metastasis, and worse clinical outcomes as evidenced by a higher risk of recurrence and a shorter survival rate. Currently, the primary options for TNBC treatment are surgery, radiation, and chemotherapy. These treatments however remain ineffective due to recurrence. However, given that p53 mutations have been identified in more than 60–88 % of TNBC, translating p53 into the clinical situation is particularly important in TNBC. In this study, we screened and evaluated the therapeutic potential of cryptolepine (CRP) in TNBC in-vitro models being an anti-malarial drug it could be repurposed as an anti-cancer therapeutic targeting TNBC. Moreover, the cytotoxicity activity of cryptolepine to TNBC cells and a detailed anti-tumor mechanism in mutant P53 has not been reported before. MethodsMTT assays were used to examine the cytotoxicity and cell viability activity of Cryptolepine in TNBC, non-TNBC T47D and MCF-7 and non-malignant MCF10A cells. Scratch wound and clonogenic assay was used to evaluate the cryptolepine’s effect on migration and colony forming ability of TNBC cells. Flow cytometry, MMP and DAPI was used to assess cell cycle arrest and cell apoptosis mechanism. The expression of proteins was detected by western blots. The differential expression of RNAs was evaluated by RT-PCR and the interaction between P53 and drug was evaluated computationally using in-silico approach and in-vitro using ChIP assay. ResultsIn this study, we found that cryptolepine has more preferential cytotoxicity in TNBC than non-TNBC cells. Notably, our studies revealed the mechanism by which cryptolepine induces intrinsic apoptosis and inhibit migration, colony formation ability, induce cell cycle arrest by inducing conformational change in the mutant P53 thereby increasing its DNA binding ability, hence activating its tumor suppressing potential significantly. ConclusionOur study revealed that CRP significantly reduced the proliferation, migration and colony forming ability of TNBC cells lines. Moreover, it was revealed that CRP induces cell cycle arrest and apoptosis by activating mutant P53 and enhancing its DNA binding ability to induce its tumor suppressing ability.

Targeting lipid peroxidation-associated ferroptosis suppresses lung carcinoma progression by regulating cell cycle arrest

Lung carcinoma is a frequently encountered cancerous growth that affects the respiratory tract and has a high occurrence rate globally. In light of the ongoing worldwide health emergency, the significance of efficient therapeutic agents and strategies is of utmost importance. A meticulous control of the cell cycle is crucial for comprehending the pathophysiology and molecular causes of lung cancer, as well as for the formulation of efficacious therapeutic medicines. The mechanism by which cells synchronize cell cycle with cell survival and death is still not fully understood. In this study, we demonstrate that the halting of the cell cycle has a strong inhibitory impact on ferroptosis, a specific type of controlled cell death triggered by excessive lipid peroxidation at the membranes of cells. Ferroptosis is halted through the mechanism of cell cycle arrest, which involves the deposition of intracellular lipids mediated by diacylglycerol acyltransferase (DGAT). Excessive amounts of polyunsaturated fatty acids (PUFAs) are stored as triacylglycerols (TAGs) within inactive cells. As a result, inhibiting DGAT causes a rearrangement of PUFAs from TAGs to phospholipids and makes arrested cells more susceptible to ferroptosis. We demonstrate that certain lung cancer cells that are resistant to antimitotic drugs and have a slow-cycling behavior exhibit an increase in lipid droplets. Furthermore, we find that the growth of tumors resistant to 5-fluorouracil, lorlatinib, and docetaxel can be effectively suppressed by a combination treatment involving the use of ferroptosis inducers and DGAT inhibitors, which induces ferroptosis. Collectively, these findings demonstrate the involvement of cell cycle arrest in conferring resistance to ferroptosis and propose a potential therapeutic approach for addressing the challenge of slow-cycling malignancies that exhibit resistance to ferroptosis.

LKB1 Mutations Enhance Radiosensitivity in Non-Small Cell Lung Cancer Cells by Inducing G2/M Cell Cycle Phase Arrest.

Radiosensitivity remains an important factor affecting the clinical outcome of radiotherapy for non-small cell lung cancer (NSCLC). Liver kinase B1 (LKB1) as a tumor suppressor, is one of the most commonly mutated genes in NSCLC. However, the role of LKB1 on radiosensitivity and the possible mechanism have not been elucidated in the NSCLC. In this study, we investigated the regulatory function of LKB1 in the radiosensitivity of NSCLC cells and its possible signaling pathways. After regulating the expression of LKB1, cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay. The flow cytometry assay was used to analyse cell cycle distribution. Survival fraction and sensitization enhancement ratio (SER) were generated by clonogenic survival assay. Western blot analysis was used to assess expression levels of LKB1, p53, p21, γ-H2AX and p-Chk2. Our study found that when the NSCLC cells were exposed to ionizing radiation, LKB1 could inhibit NSCLC cell proliferation by promoting DNA double strand break and inducing DNA repair. In addition, LKB1 could induce NSCLC cells G1 and G2/M phase arrest through up-regulating expression of p53 and p21 proteins. This current study demonstrates that LKB1 enhances the radiosensitivity of NSCLC cells via inhibiting NSCLC cell proliferation and inducing G2/M phase arrest, and the mechanism of cell cycle arrest associated with signaling pathways of p53 and p21 probably.

Cells use multiple mechanisms for cell-cycle arrest upon withdrawal of individual amino acids

Amino acids are required for cell growth and proliferation, but it remains unclear when and how amino acid availability impinges on the proliferation-quiescence decision. Here, we used time-lapse microscopy and single-cell tracking of cyclin-dependent kinase 2 (CDK2) activity to assess the response of individual cells to withdrawal of single amino acids and found strikingly different cell-cycle effects depending on the amino acid. For example, upon leucine withdrawal, MCF10A cells complete two cell cycles and then enter a CDK2-low quiescence, whereas lysine withdrawal causes immediate cell-cycle stalling. Methionine withdrawal triggers a restriction point phenotype similar to serum starvation or Mek inhibition: upon methionine withdrawal, cells complete their current cell cycle and enter a CDK2-low quiescence after mitosis. Modulation of restriction point regulators p21/p27 or cyclin D1 enables short-term rescue of proliferation under methionine and leucine withdrawal, and to a lesser extent lysine withdrawal, revealing a checkpoint connecting nutrient signaling to cell-cycle entry.

Yinzhihuang injection induces apoptosis and suppresses tumor growth in acute myeloid leukemia cells.

The unmet needs in treating acute myeloid leukemia(AML) promote us to look for more effective and less toxic therapies. In this study, we discovered that Yinzhihuang injection(YZHI), a traditional Chinese patent medicine for hepatitis treatment, suppressed the growth of AML cells. Anti-proliferative activities of YZHI were measured by CCK-8 assay. Cell cycle arrest was evaluated by PI staining, and apoptosis was evaluated by annexin V/PI staining. To explore the cell cycle arrest and cell death mechanism induced by YZHI, we assessed a series of assays, including measurements of the protein expression and cellular ATP. The anti-tumor activity was further demonstrated in nude mice. Flow cytometric and biochemical analysis revealed that YZHI caused cell cycle arrest and induced apoptosis in the AML HL-60 cells. Mechanistically, YZHI activated AMPK by promoting phosphorylation of the kinase. The active AMPK negatively regulated the downstream target mTORC1, leading to the inhibition of cell proliferation and induction of apoptosis. Pretreatment with the AMPK inhibitor compound C rescued YZHI induced apoptosis and partially restored cell proliferation of HL-60. Consistent with the data in vitro, YZHI obviously suppressed subcutaneous xenograft growth in nude mice. In a word, our data suggest that YZHI can be repurposed for the treatment of AML, which is worthy of further clinical evaluation.

Ebracteolatain A Inhibits Lung Cancer Growth via p21 and p27 Mediated Cell-Cycle Arrest

Objective: Lung cancer is a refractory tumor with a poor five-year survival rate. Ebracteolatain A (EA), a key acetyl-phloroglucinol derived from the traditional Chinese herb Langdu, has been reported to have anti-tumor activity in human breast cancer. However, the therapeutic efficacy and underlying mechanism of lung cancer remain to be elucidated. In the present study, we intended to evaluate whether EA exhibits anti-lung cancer activity and elucidate the underlying mechanisms. Methods: ATPlite and clonogenic survival assays were used to assess the inhibiting effect of EA on two lung cancer cell lines in vitro. FACS was conducted to determine the cell-cycle profiling of lung cancer cells upon treatment with EA. Western blot was performed to detect the level of related proteins in EA-treated lung cancer cells. RNA silencing and other experiments were used to identify the molecular mechanism of EA-triggered cell-cycle arrest. Furthermore, a xenograft tumor model was constructed to evaluate the therapeutic effect and potential mechanism of EA in vivo in mice. Results: EA significantly inhibited the growth of lung cancer cells both in vitro and in vivo. Mechanistically, EA-induced G1 phase cell-cycle arrest is mediated by the accumulation of p21 and p27. Conclusion: Our findings revealed the anti-lung cancer effect of EA and the mechanisms, providing a solid scientific basis for EA as an attractive choice for lung cancer therapy.

MiR-155-5p-mediated increase in p53 content induced by dacarbazine in melanoma cells

BACKGROUND: Cellular senescence is a stress response, triggered by various stimuli such as chemotherapy treatment and causes G0/G1 cell cycle arrest followed by the production of a senescence associated secretory phenotype. p53 considered to be a modulator of these events although the precise mechanisms of it remains not clear.
 AIMS: To determine the non-apoptotic functions of the p53 protein the formation of the senescence associated secretory phenotype phenotype of melanoma cells under the treatment of the cytostatic agent dacarbazine.
 MATERIALS AND METHODS: The study was conducted on BRO and SK-MEL-2 skin melanoma cell lines. Melanoma cells were were treated by cytostatic agent dacarbazine. Then immunocytochemical study was performed to determine the proportion of G0-positive cells and the expression of the tumor suppressor protein p53. A bioinformatic analysis was accomplished to identify for p53 regulators with determining of miR-155-5p levels in exosomes released by dacarbazine-treated melanoma cells.
 RESULTS: The cytostatic drug dacarbazine increases the proportion of cells residing in the G0 phase of the cell cycle. Onco-microRNA miR-155-5p was expressed in the exosomes of the two studied cell lines BRO and SK-MEL-2 of skin melanoma. Changes in the expression level of p53 correlate with changes in miR-155-5p microRNA expression. The absence of changes in p53 expression in BRO melanoma cells may be due to the absence of changes in miR-155-5p expression levels. In the BRO cell line, no changes in the expression of the oncosuppressor p53 were observed with an increased percentage of G0-positive cells, which may be associated with the activation of other mechanisms of cell cycle arrest in the G0/G1 phase.
 CONCLUSIONS: Heterogeneous effect of the cytostatic agent dacarbazine on melanoma cells was revealed. For the SK-MEL-2 cell line, dacarbazine induces the release of senescence associated secretory phenotype by inhibiting exosomal production of miR-155-5p, which activates the p53 oncosuppressor, which was not observed in the BRO line.

How Do Plants Cope with DNA Damage? A Concise Review on the DDR Pathway in Plants.

DNA damage is induced by many factors, some of which naturally occur in the environment. Because of their sessile nature, plants are especially exposed to unfavorable conditions causing DNA damage. In response to this damage, the DDR (DNA damage response) pathway is activated. This pathway is highly conserved between eukaryotes; however, there are some plant-specific DDR elements, such as SOG1-a transcription factor that is a central DDR regulator in plants. In general, DDR signaling activates transcriptional and epigenetic regulators that orchestrate the cell cycle arrest and DNA repair mechanisms upon DNA damage. The cell cycle halts to give the cell time to repair damaged DNA before replication. If the repair is successful, the cell cycle is reactivated. However, if the DNA repair mechanisms fail and DNA lesions accumulate, the cell enters the apoptotic pathway. Thereby the proper maintenance of DDR is crucial for plants to survive. It is particularly important for agronomically important species because exposure to environmental stresses causing DNA damage leads to growth inhibition and yield reduction. Thereby, gaining knowledge regarding the DDR pathway in crops may have a huge agronomic impact-it may be useful in breeding new cultivars more tolerant to such stresses. In this review, we characterize different genotoxic agents and their mode of action, describe DDR activation and signaling and summarize DNA repair mechanisms in plants.

Cell Cycle Dynamics during Stomatal Development: Window of MUTE Action and Ramification of Its Loss-of-Function on an Uncommitted Precursor.

Plants develop in the absence of cell migration. As such, cell division and differentiation need to be coordinated for functional tissue formation. Cellular valves on the plant epidermis, stomata, are generated through a stereotypical sequence of cell division and differentiation events. In Arabidopsis, three master regulatory transcription factors, SPEECHLESS (SPCH), MUTE and FAMA, sequentially drive initiation, proliferation and differentiation of stomata. Among them, MUTE switches the cell cycle mode from proliferative asymmetric division to terminal symmetric division and orchestrates the execution of the single symmetric division event. However, it remains unclear to what extent MUTE regulates the expression of cell cycle genes through the symmetric division and whether MUTE accumulation itself is gated by the cell cycle. Here, we show that MUTE directly upregulates the expression of cell cycle components throughout the terminal cell cycle phases of a stomatal precursor, not only core cell cycle engines but also check-point regulators. Time-lapse live imaging using the multicolor Plant Cell Cycle Indicator revealed that MUTE accumulates up to the early G2 phase, whereas its successor and direct target, FAMA, accumulate at late G2 through terminal mitosis. In the absence of MUTE, meristemoids fail to differentiate and their G1 phase elongates as they reiterate asymmetric divisions. Together, our work provides the framework of cell cycle and master regulatory transcription factors to coordinate a single symmetric cell division and suggests a mechanism for the eventual cell cycle arrest of an uncommitted stem-cell-like precursor at the G1 phase.

Fu Fang Gang Liu aqueous extract inhibits the proliferation of HeLa cells by causing deoxyribonucleic acid damage

Ethnopharmacological relevanceFu Fang Gang Liu (FFGL) is an effective formula for treating wart proliferation caused by human papillomavirus (HPV) infection and has the potential to treat HPV-related cancers. However, scientific evidence of its anti-tumor activity against cervical cancer, the most common cancer caused by HPV, is lacking. Aim of the studyTo clarify the anti-tumor effect of an FFGL aqueous extract on human cervical cancer and its possible mechanism of cell cycle arrest in HeLa cells. Materials and methodsThe anti-proliferative effect of FFGL on cervical cancer cells was assessed using the cell counting kit-8 assay. The proportion of apoptotic cells, cell cycle distribution, and cell division rate were determined using flow cytometry. Quantitative proteomics was used to identify differentially expressed proteins after FFGL treatment, and bioinformatics analysis was used to identify key nodal proteins affected by FFGL. Immunofluorescence and western blot analyses were used to explore changes in the expression of related proteins in the cell cycle and DNA damage pathways to elucidate the potential mechanism of action of FFGL against HeLa cell proliferation. ResultsFFGL inhibited cervical cancer cell proliferation and caused cell cycle arrest. According to quantitative proteomics, CyclinB1 may play an important role in the anti-proliferative effect of FFGL on HeLa cells. Additional experiments showed that FFGL aqueous extract caused ATM-mediated DNA damage, further phosphorylated CHK2, led to the inactivation of Cdc25C, inhibited the activity of the CDK1/CyclinB1 complex, and resulted in cell cycle arrest. ConclusionsFFGL can inhibit cervical cancer cell proliferation. Furthermore, it can increase CDK1 phosphorylation, block the cell cycle by causing DNA damage, and inhibit HeLa cell proliferation.

The function of p53 and its role in Alzheimer's and Parkinson's disease compared to age-related macular degeneration.

The protein p53 is the main human tumor suppressor. Since its discovery, extensive research has been conducted, which led to the general assumption that the purview of p53 is also essential for additional functions, apart from the prevention of carcinogenesis. In response to cellular stress and DNA damages, p53 constitutes the key point for the induction of various regulatory processes, determining whether the cell induces cell cycle arrest and DNA repair mechanisms or otherwise cell death. As an implication, aberrations from its normal functioning can lead to pathogeneses. To this day, neurodegenerative diseases are considered difficult to treat, which arises from the fact that in general the underlying pathological mechanisms are not well understood. Current research on brain and retina-related neurodegenerative disorders suggests that p53 plays an essential role in the progression of these conditions as well. In this review, we therefore compare the role and similarities of the tumor suppressor protein p53 in the pathogenesis of Alzheimer's (AD) and Parkinson's disease (PD), two of the most prevalent neurological diseases, to the age-related macular degeneration (AMD) which is among the most common forms of retinal degeneration.

Dysfunction of DNA repair for boosted tumor cell cycle arrest based on NIR-II biodegradable Te-prussian blue nanorod

Reactive oxygen species (ROS)-mediated cell cycle arrest mechanism shows distinguished potential for the inhibiting of cancer cells. However, poly ADP-ribose polymerase (PARP), an enzyme which can contribute to the repair of single-strand DNA nicks, largely limited the efficiency in cell cycle arrest. Here, polydopamine (PDA)/hyaluronic acid (HA) decorated and protein translation inhibitor homoharringtonine (HHT) loaded tellurium (Te)-prussian blue (PB) nanorods (Te@PB@PDA-HA/HHT NRs) were synthesized for boosted G2 cell cycle arrest to realize tumor ablation. Under NIR-II irradiation, Te and Fe elements can collectively generate ROS and deplete GSH due to the fenton-like reaction and metal-reducing reaction under tumor microenvironment (TME), thus disturbing the DNA structure to induce cell cycle arrest. More importantly, HHT suppresses PARP production to induce DNA repair dysfunction, thereby boosting DNA oxidative damage. Remarkably, this nanoplatform degrades into ionic form under acid condition, illustrating inherently TME-responsive biodegradability. The anti-tumor evaluation illustrated that Te@PB@PDA-HA/HHT NRs could notably destroy tumor cells in both cellular experiments and mouse models. This study made a successful attempt in boosted cell cycle arrest and encouraged more biological explorations on biodegradation nanomaterials, especially in combating cancers.

Treatment with quercetin inhibits SARS-CoV-2 N protein-induced acute kidney injury by blocking Smad3-dependent G1 cell-cycle arrest

Increasing evidence shows that SARS-CoV-2 can infect kidneys and cause acute kidney injury (AKI) in critically ill COVID-19 patients. However, mechanisms through which COVID-19 induces AKI are largely unknown, and treatment remains ineffective. Here, we report that kidney-specific overexpressing SARS-CoV-2N gene can cause AKI, including tubular necrosis and elevated levels of serum creatinine and BUN in 8-week-old diabetic db/db mice, which become worse in those with older age (16weeks) and underlying diabetic kidney disease (DKD). Treatment with quercetin, a purified product from traditional Chinese medicine (TCM) that shows effective treatment of COVID-19 patients, can significantly inhibit SARS-CoV-2N protein-induced AKI in diabetic mice with or without underlying DKD. Mechanistically, quercetin can block the binding of SARS-CoV-2N protein to Smad3, thereby inhibiting Smad3 signaling and Smad3-mediated cell death via the p16-dependent G1 cell-cycle arrest mechanism invivo and invitro. In conclusion, SARS-CoV-2N protein is pathogenic and can cause severe AKI in diabetic mice, particularly in those with older age and pre-existing DKD, via the Smad3-dependent G1 cell-cycle arrest mechanism. Importantly, we identify that quercetin may be an effective TCM compound capable of inhibiting COVID-19 AKI by blocking SARS-CoV-2 N-Smad3-mediated cell death pathway.

MORPHOLOGICAL FEATURES OF STRESS MARKERS IN PLACENTA

Introduction. The multinucleated syncytiotrophoblast of human placental villi is responsible for transport functions between thematernal and fetal circulation and is the main site of protein synthesis and steroid production. It is formed by the fusion of underlyingcytotrophoblast cells. The nuclei of the multinucleated syncytiotrophoblast are nonmitotic, but the mechanism of cell cycle arrest in thesyncytiotrophoblast is not known. Single publications have described that cell fusion induces a cellular senescence, best known as acomponent of the stress response and an important factor in preventing tumor cell growth. For syncytiotrophoblast, one of the criteriaof its aging is the formation of so-called syncytial nodes - local accumulations of nuclear material with protrusion of these cells into theinterstitial space.The purpose of the study. To determine the morphological features in women's placentas under the influence of chronic stresscaused by coronavirus disease and internal irradiation, with the subsequent formation of criteria for diagnosing diseases and assessingthe severity of lesions in the mother and fetus.Material and methods. A morphological study of syncytial nodules in the villi of the placenta of groups of women with chronic stressdue to internal irradiation and COVID-19 (classified by severity of the disease) was performed in comparison with the physiologicalcourse of pregnancy and childbirth. Histopathological and ultrastructural examination of placentas was performed with the detection ofsyncytial nodes with morphometric analysis of their ultrastructural features of the nuclear component of syncytiotrophoblast nodules andtheir comparison in clinical groups. The number of syncytial nodes was estimated on histological specimens stained with hematoxylinand eosin. The effect of chronic stress in women was significantly (p<0.05) confirmed by increased cortisol levels (saliva test). Statisticalprocessing of the results was carried out using licensed programs «Microsoft Excel» and «Statistica». The design of the study and allmethods used in this study were reviewed and approved by the Bioethics Committee of the State Institution «Institute of Pediatrics,Obstetrics and Gynecology named after Academician O.M. Lukyanova of the National Academy of Medical Sciences of Ukraine», Kyiv,Ukraine.Results of the study. Morphological examination of the placental tissue of parturient women with COVID-19 showed an increasein the number of syncytial nodes in the villi, which we associated with the presence of stress. Ultrastructural studies revealed changes inthe nuclei of syncytial nodules depending on the pathology.Conclusion. An increase in the number of syncytial nodes in the chorionic structures in internal radiation and COVID-19 in pregnantwomen has been established, which is important as predictors of placental factors for the health of the individual in the future.

Computational and experimental therapeutic efficacy analysis of andrographolide phospholipid complex self-assembled nanoparticles against Neuro2a cells

BackgroundNeuroblastoma is one of the most common malignancies in childhood, accounts for approximately 7% of all malignancies. Andrographolide (AN) inhibits cancer cells progression via multiple pathways like cell cycle arrest, mitochondrial apoptosis, NF-κβ inhibition, and antiangiogenesis mechanism. Despite multiple advantages, application of AN is very limited due to its low aqueous solubility (6.39 ± 0.47 μg/mL), high lipophilicity (log P ∼ 2.632 ± 0.135), and reduced stability owing to pH sensitive lactone ring. Objectives and resultsIn present investigation, a molecular complex of AN with soya-L-α-phosphatidyl choline (SPC) was synthesized as ANSPC and characterized by FT-IR and1H NMR spectroscopy. Spectral and molecular simulation techniques confirmed the intermolecular interactions between the 14-OH group of AN and the N+(CH3)3part of SPC. In addition, molecular dynamics (MD) simulation was used to determine the degree of interaction between various proteins such as TNF-α, caspase-3, and Bcl-2. Later, ANSPC complex was transformed in to self-assembled soft nanoparticles of size 201.8 ± 1.48 nm with PDI of 0.092 ± 0.004 and zeta potential of −21.7 ± 0.85 mV. The IC50 offree AN (8.319 μg/mL) and the self-assembled soft ANSPC nanoparticles (3.406 μg/mL ∼ 1.2 μg of AN) against Neuro2a cells was estimated with significant (P < 0.05) difference. Interestingly, the self-assembled soft ANSPC nanoparticles showed better endocytosis compared to free AN in Neuro2a cells. In-vitrobiological assays confirmed that self-assembled soft ANSPC nanoparticles induces apoptosis in Neuro2a cells by declining the MMP (Δψm) and increasing the ROS generation. ConclusionSelf-assembled soft ANSPC nanoparticles warrant further in-depth antitumor study in xenograft model of neuroblastoma to establish the anticancer potential.

Revisiting the anticancer properties of phosphane(9-ribosylpurine-6-thiolato)gold(I) complexes and their 9H-purine precursors

New mono- and di-nuclear thio-purine and thio-purine nucleoside gold(I) complexes were synthesized, characterized, and evaluated in vitro for biological activities in comparison to related known purine complexes. By combining known anti-tumoral thio-purines with R3PAu moieties as present in auranofin, complexes with enhanced effects and selectivities were obtained, which not only act as cytostatics, but also disrupt tumor-specific processes. Their IC50 values in cytotoxicity test with tumor cell lines ranged from three-digit nanomolar to single-digit micromolar, revealing a tentative structure–activity relationship (SAR). Both the residues R2 of the phosphane ligand and R1 at C2 of the pyrimidine ring had a significant impact on the cytotoxicity. In most cases, the introduction of a ribo-furanosyl group at N9 of the purine led to a distinctly more cytotoxic complex. Most complexes were more active against multi-drug-resistant tumor cells or such lacking functional p53 when compared to the respective untreated wild type cell lines. Some nucleoside complexes displayed an interesting dose-dependent dual mode of action regarding cell cycle arrest and DNA repair mechanism. Some phosphane(purine-6-thiolato)gold (I) complexes had a stronger inhibitory effect on the thioredoxin reductase (TrxR) and on the reactive oxygen species (ROS) generation in cancer cells than is typical of other gold complexes. They also led to DNA fragmentation and showed anti-angiogenic effects. Their stability under test conditions was demonstrated by 77Se NMR monitoring of an exemplary selenopurine complex.Graphical abstract

Evodiamine inhibits ESCC by inducing M-phase cell-cycle arrest via CUL4A/p53/p21 axis and activating noxa-dependent intrinsic and DR4-dependent extrinsic apoptosis

BackgroundEsophageal squamous cell carcinoma (ESCC) is a malignancy with high incidence in several regions of China, and the prognosis of patients with ESCC is unfavorable. Evodiamine (Evo), a small molecule derived from the traditional Chinese herb Evodia rutaecarpa, has shown anti-cancer efficacy in numerous human malignancies but not in ESCC. PurposeTo determine whether Evo induces cell-cycle arrest and apoptosis in ESCC in vitro and in vivo and elucidate the underlying mechanisms. MethodsATPlite and colony formation assay were used to validate the inhibiting effect of Evo on three ESCC cells in vitro; Two subcutaneous tumor models of ESCC cells were used to evaluate the anti-ESCC effect of Evo and assess the biosafety of Evo in vivo; RNAseq and Database of KEGG pathway analysis provided a direction for the mechanistic study of Evo; FACS was used to detect Evo-induced cell cycle arrest and cell apoptosis in ESCC cells; Western blot and QPCR were respectively used to detect the level of related genes and proteins in Evo-treated ESCC cells; SiRNA and other experimental techniques were used to identify the molecular mechanism of Evo-induced ESCC cell cycle arrest and cell apoptosis. ResultsEvo significantly suppressed the growth of ESCC both in vitro and in vivo. Mechanistically, Evo induced M-phase cell-cycle arrest by inactivation of CUL4A E3 ligase, which mediates degradation blockage of p53 and transcriptional activation of p21. With the prolonged treatment time, Evo triggered both Noxa-dependent intrinsic and DR4-dependent extrinsic cell apoptosis in two ESCC cell lines. ConclusionOur findings revealed the anti-tumor efficacy and mechanisms of Evo, providing a solid scientific basis for Evo as an attractive choice for ESCC treatment.

Small-molecule MX-C2/3 suppresses non-small cell lung cancer progression via p53 activation

p53 inactivation is a common feature in non-small cell lung cancer (NSCLC) resulting in NSCLC malignant transformation. Targeting serine 392 phosphorylation to restore p53 anticancer activity has proven to be an effective therapeutic strategy against NSCLC. A synthetic p53 activator, NA-17, has been developed that shows promise in preclinical models of NSCLC. However, NA-17 exhibits limited therapeutic efficacy in oncogene-driven tumors as well as relatively high toxicity to normal cells. It is possible that high efficiency and low toxicity p53 activators can be obtained by optimizing the leading molecule. Here, we performed high-throughput screening of compounds optimized based on NA-17 to identify new p53 activators. Two promising candidates named MX-C2 and MX-C3 were identified, both exhibited considerable therapeutic efficacy in oncogene-driven tumor models. Similar to NA-17, MX-C2/3 induced p53 activation via phosphorylating serine-392 without DNA damage. Both compounds showed broad antitumor activity in NSCLC cells and limited toxicity in normal cell lines. Moreover, MX-C2/3 suppressed tumor progression by arresting the cell cycle at G2/M phase, exhibiting a different mechanism of cell cycle arrest than NA-17. In addition, MX-C2/3 promoted the enrichment of p-p53 (s392) in mitochondria, leading to the conformational activation of Bak for cell apoptosis, which is consistent with NA-17. Finally, we demonstrated that MX-C2 significantly inhibited tumor growth without obvious systemic toxicity in oncogene-driven HCC-827 xenograft models. Collectively, we report two p53 activators with high-efficiency and low-toxicity that target p53 serine 392 phosphorylation for anticancer translational investigation.

Functional Drug Screening of Small Molecule Inhibitors of Epigenetic Modifiers in Refractory AML Patients.

Simple SummaryAcute myeloid leukemia is a cancer originating in the bone marrow and peripheral blood. Genetic mutations observed with the disease are difficult to target therapeutically and patients often have different treatment responses to the standard of care. By finding epigenetic compounds that work in a variety of patients, we could discover better therapies to treat the disease apart from the current standard of care. Here we present an unbiased drug screen of a variety of epigenetic compounds, with some showing effective responses in all or most patient samples. The use of inhibitors of epigenetic modifiers in the treatment of acute myeloid leukemia (AML) has become increasingly appealing due to the highly epigenetic nature of the disease. We evaluated a library of 164 epigenetic compounds in a cohort of 9 heterogeneous AML patients using an ex vivo drug screen. AML blasts were isolated from bone marrow biopsies according to established protocols and treatment response to the epigenetic library was evaluated. We find that 11 histone deacetylase (HDAC) inhibitors, which act upon mechanisms of cell cycle arrest and apoptotic pathways through inhibition of zinc-dependent classes of HDACs, showed efficacy in all patient-derived samples. Other compounds, including bromodomain and extraterminal domain (BET) protein inhibitors, showed efficacy in most samples. Specifically, HDAC inhibitors are already clinically available and can be repurposed for use in AML. Results in this cohort of AML patient-derived samples reveal several epigenetic compounds with high anti-blast activity in all samples, despite the molecular diversity of the disease. These results further enforce the notion that AML is a predominantly epigenetic disease and that similar epigenetic mechanisms may underlie disease development and progression in all patients, despite differences in genetic mutations.