Phase Cell Cycle Arrest Research Articles

Effective Synthesis of C20-Epi-Isothiocyanato-Salinomycin and its Thiourea Derivatives as Potential Anticancer Agents.

Salinomycin, a naturally occurring polyether ionophore antibiotic isolated from Streptomyces albus, has been demonstrated potent cytotoxic activity against a variety of cancer cell lines. In particular, it exhibits selective targeting of cancer stem cells. However, systemic toxicity, drug resistance and low bioavailability of the drug significantly limit its potential applications. In this study, the C20-epi-isothiocyanate of salinomycin was designed and synthesized, and then reacted with amines as a versatile synthon to assemble a series of salinomycin thiourea derivatives, which improved the druggability of salinomycin. The antiproliferative activities of the compounds were evaluated in vitro against A549, HepG2, HeLa, 4T1, and MCF-7 cancer cell lines using the CCK-8 assay. The pharmacological results showed that some salinomycin thiourea derivatives exhibited excellent inhibitory activity against at least one of the tested tumor cells and high selectivity. Further mechanistic studies showed that compound 9 f, containing a 3,5-difluorobenzyl moiety, could directly induce apoptosis, probably by increasing caspase-9 protein expression and cell cycle arrest in G1 phase in a concentration dependent manner.

Parecoxib inhibits tumorigenesis and angiogenesis in hepatocellular carcinoma through ERK-VEGF/MMPs signaling pathway.

Parecoxib, a well-recognized nonsteroidal anti-inflammatory drug, has been reported to possess anticancer properties in various tumor types. In this work, we aimed to investigate the potential anticancer effects of parecoxib on hepatocellular carcinoma (HCC) cells. To assess the impact of parecoxib on HCC cell proliferation, we employed Cell Counting Kit-8, colony formation, and 5-ethynyl-2'-deoxyuridine assays. Hoechst/propidium iodide (PI) double staining and flow cytometry were performed to evaluate apoptosis and cell cycle analysis. Wound healing and transwell assays were utilized to assess cell migration and invasion. Tube formation assay was employed to analyze angiogenesis. Protein levels were determined using western blotting, and mRNA expression levels were assessed using quantitative real-time polymerase chain reaction (PCR). A xenograft mouse model was used to confirm the antitumor effects of parecoxib on HCC tumors in vivo. Our data demonstrated that parecoxib effectively inhibited the proliferation of HCC cells in a dose- and time-dependent manner. In addition, parecoxib induced cell cycle arrest in the G2 phase and promoted apoptosis. Moreover, parecoxib hindered tumor migration and invasion by impeding the epithelial-mesenchymal transition process. Further investigation showed that parecoxib could significantly suppress angiogenesis through the inhibition of extracellular signal-regulated kinase (ERK)-vascular endothelial growth factor (VEGF) axis. Notably, treatment with the ERK activator phorbol myristate acetate upregulated the expression of matrix metalloproteinase (MMP)-2, MMP-9, and VEGF and reversed the function of parecoxib in HCC cells. Besides, parecoxib displayed its antitumor efficacy in vivo. Collectively, our results suggest that parecoxib ameliorates HCC progression by regulating proliferation, cell cycle, apoptosis, migration, invasion, and angiogenesis through the ERK-VEGF/MMPs signaling pathway.

Single-agent Adavosertib Shows Anticancer Effects Against Colorectal Cancer Cells.

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related deaths worldwide. Adavosertib (AZD1775), a small molecule inhibitor of WEE1 kinase, abrogates G2/M cell cycle arrest and induces double-stranded DNA breaks. According to previous findings, adavosertib, in combination with other DNA-damaging agents, causes premature mitosis and cell death in p53-mutated cancer cells mainly via abrogation of the G2/M cell cycle checkpoint. This study aims to evaluate the inhibition of WEE1 kinase by adavosertib as monotherapy in the TP53-wildtype human CRC cell line HCT116. In this study, HCT116 cells were treated with different concentrations of adavosertib for 24 to 72 hours. Cell viability was assessed by Water-Soluble Tetrazolium 1 (WST-1) assay and crystal violet assays. Cell migration was evaluated by the wound healing assay. Cell cycle distribution and apoptosis were analyzed by flow cytometry. The IC50 value of adavosertib for the HCT116 cell line was 0.1310 μM. Adavosertib monotherapy (both 0.125 and 0.250 μM) significantly reduced cell viability, inhibited cell migration and abrogated intra-S phase cell cycle arrest. In addition, 0.250 μM of adavosertib significantly induced apoptosis in HCT116 cells. Adavosertib effectively inhibits the TP53-wildtype HCT116 cells via the abrogation of intra-S phase cell cycle arrest. Our findings suggest that adavosertib monotherapy may be a potential targeted therapy for CRC.

LINC00342 regulates the PI3K-AKT signaling pathway via the miR-149-5p/FGF11 axis and affects the progression of oral cancer

BackgroundA large number of long non-coding RNAs (lncRNAs) have been implicated in the progression of oral cancer (OC). This study aimed to investigate the role of a novel lncRNA, LINC00342, in OC and elucidate its molecular mechanism.MethodsDifferential expression of lncRNA/miRNA/mRNA was analyzed using the Gene Expression Omnibus database and validated with RT-qPCR. Additionally, the expression levels of these molecules in OC cells and their effects on cell viability and cell cycle were assessed using the Cell Counting Kit-8 and flow cytometry. RNA bindings was analyzed by dual luciferase, and Western blot was used to detect the activation of relevant pathways.ResultsThis study showed that, in contrast to miR-149-5p, the expression of LINC00342 and fibroblast growth factor 11 (FGF11) were upregulated in OC cells (LINC00342: 10.00 ± 1.06 (FaDu) and 3.55 ± 0.25 (CAL-27) vs 1.00 ± 0.07 (HOECs), P < 0.05; FGF11: 7.31 ± 0.33 (FaDu) and 3.43 ± 0.08 (CAL-27) vs 1.00 ± 0.10 (HOECs), P < 0.05). Dual-luciferase assays confirmed that LINC00342 bind to miR-149-5p in a direct targeting manner. Furthermore, inhibition of LINC00342 expression resulted in decreased proliferation rate (FaDu: 136.22 ± 22.10% vs 59.36 ± 8.98% (control), P < 0.05; CAL-27: 131.40 ± 11.58% vs 49.83 ± 11.19 (control), P < 0.05) and migration ability of OC cells, cell cycle arrest in G1 phase, and inhibition of PI3K-AKT signaling. Inhibition of miR-149-5p or overexpression of FGF11 reversed the effects of si-LINC00342.ConclusionsLINC00342 promotes PI3K-AKT signaling by activating FGF11 through adsorption of miR-149-5p, thereby regulating the progression of OC.

Combining Chemotherapy Agents and Autophagy Modulators for Enhanced Breast Cancer Cell Death

Purpose: Autophagy, governed by genes with dual roles in cell death and survival, plays a crucial role in cancer persistence. Arsenic trioxide (ATO), carboplatin (CP), and cyclophosphamide (CY) are used to treat various cancers. ATO impedes cell proliferation and triggers apoptosis in cancer cells. CP, a platinum-based drug, damages cancer cell DNA, while CY acts as an alkylating agent, disrupting cell proliferation. This study investigates the combined effects of ATO, CP, and CY on inducing apoptosis and modulating autophagy in triple-negative breast cancer (TNBC) cell lines, BT-20 and MDA-MB-231. Methods: The cytotoxic effects of ATO, CP, and CY, alone and in combination, were evaluated using the MTT assay on BT-20 and MDA-MB-231 cells. Apoptosis and cell cycle progression were analyzed by annexin-V FITC/PI staining and flow cytometry. Gene expression of autophagy- and apoptosis-related markers, including Beclin 1, LC3, caspase 3, and BCL2, was quantified using RT-PCR. Data were analyzed using GraphPad Prism 4.0 with one-way ANOVA followed by Dunnett's test. Results: The The combination of ATO, CP, and CY significantly reduced cell viability and enhanced apoptosis, evidenced by increased caspase-3 activity and reduced BCL2 expression. Cell cycle arrest in the G1 phase was observed, alongside elevated autophagy markers Beclin 1 and LC3. Conclusion: The combination of ATO, CP, and CY induces synergistic effects in promoting apoptosis and autophagy in TNBC cell lines. These findings suggest that this combination therapy could be a promising approach to enhancing treatment efficacy in aggressive breast cancers, offering new insights into potential therapeutic strategies.

Novel 1,8-Naphthalimide Derivatives Inhibit Growth and Induce Apoptosis in Human Glioblastoma

Given the rapid advancement of functional 1,8-Naphthalimide derivatives in anticancer research, we synthesized these two novel naphthalimide derivatives with diverse substituents and investigated the effect on glioblastoma multiforme (GBM) cells. Cytotoxicity, apoptosis, cell cycle, topoisomerase II and Western blotting assays were evaluated for these compounds against GBM in vitro. A human GBM xenograft mouse model established by subcutaneously injecting U87-MG cells and the treatment responses were assessed. Both compounds 3 and 4 exhibited significant antiproliferative activities, inducing apoptosis and cell death. Only compound 3 notably induced G2/M phase cell cycle arrest in the U87-MG GBM cells. Both compounds inhibited DNA topoisomerase II activity, resulting in DNA damage. The in vivo antiproliferative potential of compound 3 was further validated in a U87-MG GBM xenograft mouse model, without any discernible loss of body weight or kidney toxicity noted. This study presents novel findings demonstrating that 1,8-Naphthalimide derivatives exhibited significant GBM cell suppression in vitro and in vivo without causing adverse effects on body weight or kidney function. Further experiments, including investigations into mechanisms and pathways, as well as preclinical studies on the pharmacokinetics and pharmacodynamics, may be instrumental to the development of a new anti-GBM compound.

Investigation of Apoptotic and Anticancer Effects of 2-substituted Benzothiazoles in Breast Cancer Cell Lines: EGFR Modulation and Mechanistic Insights.

Benzothiazole derivatives, a class of heterocyclic compounds, exhibited diverse biological activities influenced by substituents in the thiazole ring. This study aimed to synthesize these compounds with two functional groups to investigate their potential as anticancer agents, particularly against breast cancer. While previous research demonstrated the efficacy of 2-substituted benzothiazoles against glioma and cervical and pancreatic cancer cells, there is a gap in studies targeting breast cancer. The synthesized compounds were tested in vitro using MCF-7, MDA-MB-231, and MCF-10A cell lines, with Doxorubicin as the positive control. Various assays were conducted, including Annexin V/PI, cell cycle analysis, wound healing, and measurement of mitochondrial membrane potential. Protein expression of EGFR and transcription levels of apoptosis-related genes (Bax and Bcl-xL) and cancer progression-related genes (JAK, STAT3, ERK, AKT, mTOR) were analyzed. Additionally, the balance between antioxidants and oxidants was evaluated by measuring TAS and TOS levels. Our findings revealed that benzothiazole compounds significantly inhibited breast cancer cell growth by reducing cell motility, disrupting mitochondrial membrane potential, and inducing cell cycle arrest in the sub-G1 phase. These compounds increased reactive oxygen species accumulation, leading to cell death. Furthermore, they decreased EGFR protein levels, increased Bax gene transcription, and downregulated the expression of genes such as JAK, STAT3, ERK, AKT, and mTOR. In conclusion, benzothiazole derivatives exhibited potent inhibitory effects on breast cancer in vitro by promoting apoptosis, downregulating EGFR activity, and modulating key signaling pathways, including JAK/STAT, ERK/MAPK, and PI3K/Akt/mTOR. These results highlighted the potential of benzothiazole derivatives as novel therapeutic agents for breast cancer treatment.

Unraveling the therapeutic potential of Satureja nabateorum extract: inducing apoptosis and cell cycle arrest through p53, Bax/Bcl-2, and caspase-3 pathways in human malignant cell lines, with in silico insights

Satureja nabateorum, known as Nabatean savory is a Lamiaceae plant native to the Arabian Peninsula, specifically in the mountainous regions of Saudi Arabia. The study aims to investigate the phytochemical components of the S. nabateorum leaves (SNL) and stems (SNS) extract and to assess their antioxidant, antimicrobial, and antiproliferative properties. Methanol extracts from leaves and stems were analyzed for chemical constituents using the GC-MS technique. Antioxidant capacities were measured using hydrogen peroxide and ABTS radical-scavenging methods, and antimicrobial activity was tested against various microorganisms. Cytotoxic activity on four human malignant cell lines was assessed using MTT and flow cytometry. Molecular docking and molecular dynamics studies were conducted to understand the interactions and binding modes of the extracted compounds at a molecular level. GC-MS analysis of SNL extract revealed thymol, carvacrol, and p-cymen-8-ol as major constituents. SNS extract contained β-sitosterol, stigmasterol, lupeol, and lup-20(29)-ene-3β,28-diol. SNS extract exhibited more potent antioxidant, antimicrobial, and anticancer effects than SNL extract. The extract, SNS, exhibited potential toxicity in A549 cells with an IC50 value of 3.62 µg/mL and induced marked apoptotic effects with S phase-cell cycle arrest. SNS extract also showed higher levels of Caspase 3, Bax, p53, and the Bax/Bcl2 ratio and lower levels of Bcl-2. Molecular docking and dynamic simulation supported these findings, targeting the EGFR TK domain. The study suggests that the S. nabateorum stem extract holds promise as a potent antimicrobial, antioxidant, and anticancer agent. It provides valuable insights for considering the extract as a substitute for chemotherapy and/or protective agents.

Some novel synthesis 2-aroyl-1-acetylhydrazine derivatives: An assessment of their biological activity as therapeutic agents

Our study provides valuable insights into the anti-cancer activity of novel acetyl hydrazine derivatives as TOP2B inhibitors in breast cancer cells. Molecular docking studies were performed to evaluate the putative bonding mode of the synthesized compounds (3a, 4, 5a,b, and 6a,b). The obtained compounds were characterized using 1H NMR and 13C NMR. Most of the compounds exhibited significant inhibitory activity against breast cancer cell lines. Among them, compound (6b) demonstrated a remarkable anti-cancer effect by inducing G2/M phase cell cycle arrest and apoptosis.

Auranofin as a Novel Anticancer Drug for Anaplastic Thyroid Cancer.

Background/Objectives: Anaplastic thyroid cancer (ATC) is an aggressive and rare cancer with a poor prognosis, and traditional therapies have limited efficacy. This study investigates drug repositioning, focusing on auranofin, a gold-based drug originally used for rheumatoid arthritis, as a potential treatment for ATC. Methods: Auranofin was identified from an FDA-approved drug library and tested on two thyroid cancer cell lines, 8505C and FRO. Antitumor efficacy was evaluated through gene and protein expression analysis using Western blot, FACS, and mRNA sequencing. In vivo experiments were conducted using subcutaneous injections in nude mice to confirm the anticancer effects of auranofin. Results: Auranofin induced reactive oxygen species (ROS) production and apoptosis, leading to a dose-dependent reduction in cell viability, G1/S phase cell cycle arrest, and altered expression of regulatory proteins. It also inhibited cancer stem cell activity and suppressed epithelial-mesenchymal transition. mRNA sequencing revealed significant changes in the extracellular matrix-receptor interaction pathway, supported by Western blot results. In vivo xenograft models demonstrated strong antitumor activity. Conclusions: Auranofin shows promise as a repurposed therapeutic agent for ATC, effectively inhibiting cell proliferation, reducing metastasis, and promoting apoptosis. These findings suggest that auranofin could play a key role in future ATC treatment strategies.

“Sustainable synthesis of Camellia sinensis-mediated silver nanoparticles (CsAgNP) and their anticancer mechanisms in breast cancer cells”

The present investigation focuses on synthesizing eco-friendly and cost-effective silver nanoparticles (CsAgNP) utilizing Camellia sinensis ethanolic extract (CsE) as a reducing agent and investigating the potential enhancement in its anticancer efficacy as compared to CsE. The CsAgNP formation was confirmed through the color change from pale green to dark brown and further validated using UV–visible spectroscopy in the 400-450 nm range. The optimal CsAgNP synthesis parameters include 1:4 ratio of CsE: 1 mM AgNO3, 60 min of duration and 50 °C reaction temperature. The morphology and the size of nanoparticles were estimated using AFM, SEM and TEM where the results showed a smooth topography with a size <100 nm. The CsAgNP crystalline form was confirmed through SAED pictures and silver's presence confirmed through EDX analysis. FTIR study ascertained the capping agents and distortion in functional groups compared to CsE. The anticancer potency of CsAgNP and crude extract (CsE) was assessed against the T-47D breast cancer cells by MTT assay. CsAgNP displayed strong activity towards T-47D cells (IC50 8 μg/ml) compared to CsE and relatively low activity towards the normal HEK-293 cells. Further, fluorescence microscopy and flow cytometry data revealed that the CsAgNP promotes apoptosis and also induces G2-M phase cell cycle arrest. Furthermore, CsAgNP treatment decreases p53 and Bcl-2 protein expression, while increasing Bax, Cytochrome c and Caspase-3 levels, indicating mitochondrial-mediated apoptotic pathway activation. Thus, our research aims to investigate the potential of using Camellia sinensis to synthesize CsAgNP, a potent drug delivery system, to enhance anticancer effectiveness and advance cancer therapy in the future.

Redox-Inducible Radiomimetic Photosensitizers Selectively Suppress Cancer Cell Proliferation by Damaging DNA through Radical Cation Chemistry.

Radiotherapy leverages ionizing radiation to kill cancer cells through direct and indirect effects, and direct effects are considered to play an equal or greater role. Several photosensitizers have been developed to mimic the direct effects of radiotherapy, generating radical cations in DNA models, but none has been applied in cellular studies. Here, we design a radiomimetic photosensitizer, producing DNA radical cations in cells for the first time. To reduce adverse effects, several redox-inducible precursors are prepared as cancer cells have elevated levels of GSH and H2O2. These precursors respond to GSH or H2O2, releasing the active photosensitizer that captures DNA abasic (AP) sites and generates DNA radical cations upon photolysis, without disrupting the redox state of cells. DNA radical cations migrate freely and are eventually trapped by H2O and O2 to yield DNA lesions, thus triggering DNA damage response. Our study suggests that direct effects of radiotherapy suppress cancer cell proliferation mainly by inducing G2/M phase cell cycle arrest, rather than promoting apoptosis. Synergistic effects of the precursor and chemotherapeutic agents are also observed in combination phototherapy. Beyond highlighting an alternative strategy for phototherapy, this proof-of-concept study affords a facile cellular platform to study the direct effects of radiotherapy.

Redox‐Inducible Radiomimetic Photosensitizers Selectively Suppress Cancer Cell Proliferation by Damaging DNA through Radical Cation Chemistry

AbstractRadiotherapy leverages ionizing radiation to kill cancer cells through direct and indirect effects, and direct effects are considered to play an equal or greater role. Several photosensitizers have been developed to mimic the direct effects of radiotherapy, generating radical cations in DNA models, but none has been applied in cellular studies. Here, we design a radiomimetic photosensitizer, producing DNA radical cations in cells for the first time. To reduce adverse effects, several redox‐inducible precursors are prepared as cancer cells have elevated levels of GSH and H2O2. These precursors respond to GSH or H2O2, releasing the active photosensitizer that captures DNA abasic (AP) sites and generates DNA radical cations upon photolysis, without disrupting the redox state of cells. DNA radical cations migrate freely and are eventually trapped by H2O and O2 to yield DNA lesions, thus triggering DNA damage response. Our study suggests that direct effects of radiotherapy suppress cancer cell proliferation mainly by inducing G2/M phase cell cycle arrest, rather than promoting apoptosis. Synergistic effects of the precursor and chemotherapeutic agents are also observed in combination phototherapy. Beyond highlighting an alternative strategy for phototherapy, this proof‐of‐concept study affords a facile cellular platform to study the direct effects of radiotherapy.

Synthesis of Tetrahydrocarbazole-Tethered Triazoles as Compounds Targeting Telomerase in Human Breast Cancer Cells

Telomere shortening and the induction of senescence and/or cell death may result from inhibition of telomerase activity in cancer cells. Herein, the properties of carbazole–triazole compounds targeting telomerase in human breast cancer cells are explored. All derivatives were evaluated for loss of viability in MCF-7 breast cancer cells, with compound 5g identified as the most potent within the examined series. Green synthesis was employed using water, a reusable nano-Fe2O3-catalyzed reaction, and an electrochemical method for the synthesis of tetrahydrocarbazole and triazoles. The crystal data of compound 4 is also reported. Furthermore, in silico analysis predicted that compound 5g may target human telomerase. Molecular docking analysis of compound 5g towards hTERT predicted a binding affinity of −6.74 kcal/mol. In flow cytometry assays, compound 5g promoted apoptosis and cell cycle arrest in the G2-M phase. Finally, compound 5g inhibited the enzymatic activity of telomerase in human breast cancer cells. In conclusion, a green synthesized series of carbazole–triazoles that target telomerase in cancer cells is reported.

Parthenolide Inhibits Tumor Cell Growth and Metastasis in Melanoma A2058 Cells.

Skin melanoma is a potentially lethal cancer and ranks as the 17th most common cancer worldwide. Overcoming resistance to advanced-stage melanoma is a significant challenge in its treatment. Parthenolide (PAR) is recognized as a potent anticancer small molecule, yet its potential in treating melanoma is poorly investigated. Our objective was to investigate the apoptotic and anti-metastatic properties of PAR against the A2058 melanoma cells in vitro. This study employed various assays, such as cytotoxicity, apoptosis, cell cycle analysis, reactive oxygen species (ROS) production, mRNA expressions, western blotting, gelatin zymography, and scratch assay. The synergy between PAR and dacarbazine, a chemotherapy drug for treating skin cancer, was also assessed. Our study revealed that PAR significantly reduced the viability of A2058 cancer cells, demonstrating greater potency against cancer cells compared to normal L929 cells (IC50: 20 μM vs. 27 μM after 24h). PAR increased ROS production, elevated mRNA expression of pro-apoptotic Bax and NME1 genes, and decreased expression of the MITF gene. PAR induced apoptosis and cell cycle arrest in A2058 cells, as evidenced by the increased proportion of cells in the late apoptotic phase and sub-G1 cell cycle arrest. MMP-2 and MMP-9 mRNA and protein expressions, gelatinase activity, and the migration of A2058 cells were also decreased by PAR, suggesting its potential to suppress cancer cell invasion. These results, along with the synergic effect with dacarbazine, indicated that PAR may have the potential to be a therapeutic drug for melanoma by triggering apoptosis and suppressing invasion and migration.

Transcriptional inhibition after irradiation occurs preferentially at highly expressed genes in a manner dependent on cell cycle progression

In response to DNA double-strand damage, ongoing transcription is inhibited to facilitate accurate DNA repair while transcriptional recovery occurs after DNA repair is complete. However, the mechanisms at play and the identity of the transcripts being regulated in this manner are unclear. In contrast to the situation following UV damage, we found that transcriptional recovery after ionizing radiation (IR) occurs in a manner independent of the HIRA histone chaperone. Sequencing of the nascent transcripts identified a programmed transcriptional response, where certain transcripts and pathways are rapidly downregulated after IR, while other transcripts and pathways are upregulated. Specifically, most of the loss of nascent transcripts occurring after IR is due to inhibition of transcriptional initiation of the highly transcribed histone genes and the rDNA. To identify factors responsible for transcriptional inhibition after IR in an unbiased manner, we performed a whole genome gRNA library CRISPR/Cas9 screen. Many of the top hits on our screen were factors required for protein neddylation. However, at short times after inhibition of neddylation, transcriptional inhibition still occurred after IR, even though neddylation was effectively inhibited. Persistent inhibition of neddylation blocked transcriptional inhibition after IR, and it also leads to cell cycle arrest. Indeed, we uncovered that many inhibitors and conditions that lead to cell cycle arrest in G1 or G2 phase also prevent transcriptional inhibition after IR. As such, it appears that transcriptional inhibition after IR occurs preferentially at highly expressed genes in cycling cells.

Transcriptional inhibition after irradiation occurs preferentially at highly expressed genes in a manner dependent on cell cycle progression.

In response to DNA double-strand damage, ongoing transcription is inhibited to facilitate accurate DNA repair while transcriptional recovery occurs after DNA repair is complete. However, the mechanisms at play and the identity of the transcripts being regulated in this manner are unclear. In contrast to the situation following UV damage, we found that transcriptional recovery after ionizing radiation (IR) occurs in a manner independent of the HIRA histone chaperone. Sequencing of the nascent transcripts identified a programmed transcriptional response, where certain transcripts and pathways are rapidly downregulated after IR, while other transcripts and pathways are upregulated. Specifically, most of the loss of nascent transcripts occurring after IR is due to inhibition of transcriptional initiation of the highly transcribed histone genes and the rDNA. To identify factors responsible for transcriptional inhibition after IR in an unbiased manner, we performed a whole genome gRNA library CRISPR/Cas9 screen. Many of the top hits on our screen were factors required for protein neddylation. However, at short times after inhibition of neddylation, transcriptional inhibition still occurred after IR, even though neddylation was effectively inhibited. Persistent inhibition of neddylation blocked transcriptional inhibition after IR, and it also leads to cell cycle arrest. Indeed, we uncovered that many inhibitors and conditions that lead to cell cycle arrest in G1 or G2 phase also prevent transcriptional inhibition after IR. As such, it appears that transcriptional inhibition after IR occurs preferentially at highly expressed genes in cycling cells.

Could macrocytosis predict survival In advanced breast cancer patients that were treated with CDK 4–6 inhibitors?

IntroductionCyclin Dependent Kinase (CDK) 4–6 inhibitors are the recommended first-line treatment option for hormone-positive metastatic breast cancer (MBC). They show their effects by causing cell cycle arrest in G1-S phase. Neutropenia is the most common haematological side effect. In the literature, data on the association between CDK 4–6 inhibitors and macrocytosis are limited. We aimed to investigate the effect of macrocytosis on survival. MethodsWe retrospectively analysed 133 patients with de novo hormone positive MBC using CDK 4–6 inhibitors in first line treatment. Mean Corpuscular Volume (MCV) > 100 was considered macrocytosis and patients were divided into two groups; MCV<100 and MCV >100. The association of macrocytosis with clinicopathological features, Progression Free Survival (PFS) and Overall Survival (OS) were evaluated. Results42 patients were receiving palbociclib and 81 patients were receiving ribociclib. Median OS was determined as 33 months and median PFS was determined as 22 months. Macrocytosis ever rate was 45.8 % during follow-up. Macrocytosis was observed in 4.2 % of the patients in the first month, 16.7 % in the third month, 41.6 % in the sixth month and 42.2 % in the twelfth month. ER receptor level, ki-67, macrocytosis at 6–12 months and macrocytosis-ever which were found to affect OS as a result of univariate Cox regression analysis, were evaluated with multivariate Cox regression models and it was observed that they had significant effect on PFS and OS. ConclusionMacrocytosis may be a useful biomarker for the prediction of PFS and OS in MBC patients receiving CDK 4–6 inhibitors.

Insights into Clematis cirrhosa L. Ethanol Extract: Cytotoxic Effects, LC-ESI-QTOF-MS/MS Chemical Profiling, Molecular Docking, and Acute Toxicity Study

Background: In Jordanian traditional medicine, Clematis cirrhosa is commonly employed for the management of different diseases. Numerous investigations have documented the cytotoxic properties of different Clematis species against numerous types of cancer. Previously, we demonstrated the potential cytotoxicity of Clematis cirrhosa against HT-29 colorectal cancer cells. Extending our work, the current research aimed to explore the possible mechanisms underlying its antiproliferative activity with a plant safety evaluation. Methods: This study evaluates the extract’s impact on the cell cycle, apoptosis, and cell migration through in vitro assays, LC-ESI-QTOF-MS/MS analysis, docking studies, and an acute toxicity evaluation. Results: The Clematis cirrhosa ethanol extract (CEE) induced G2/M phase cell cycle arrest (19.63%), triggered significant apoptosis (41.99%), and inhibited cell migration/wound healing by 28.15%. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed increased expression of the proapoptotic markers BAX (6.03-fold) and caspase-3 (6.59-fold), along with the reduced expression of the antiapoptotic BCL-2, in CEE-treated cells. Moreover, CEE significantly restrained angiogenesis by reducing VEGF mRNA expression by 63.9%. High-resolution LC-ESI-QTOF-MS/MS studies identified 26 metabolites, including phenolic compounds, fatty acids, and triterpenoids. Docking studies suggested that manghaslin had the highest binding affinity for VEGFR-2, followed by calceolarioside B, quercetin 7-O-rhamnopyranoside, luteolin, and quercetin-3,7-O-diglucoside. On the other hand, salvadoraside exhibited the highest binding affinity for the inhibition of caspase-3, followed by quercetin-3,7-O-diglucoside, kaempferol-3,7-O-α-L-dirhamnoside, manghaslin, and tectoridin, supporting the observed apoptotic effects. Interestingly, the outcomes further indicate that a single oral administration of up to 5000 mg/kg CEE is safe for consumption. Conclusions: These outcomes point to the potential of Clematis cirrhosa as a promising candidate for further exploration in cancer therapy.

Silmitasertib in Combination With Cabozantinib Impairs Liver Cancer Cell Cycle Progression, Induces Apoptosis, and Delays Tumor Growth in a Preclinical Model.

The rising incidence of hepatocellular carcinoma (HCC) is a global problem. Several approved treatments, including immune therapy and multi-tyrosine kinase inhibitors, are used for treatment, although the results are not optimum. There is an unmet need to develop highly effective chemotherapies for HCC. Targeting multiple pathways to attack cancer cells is beneficial. Cabozantinib is an orally available bioactive multikinase inhibitor and has a modest effect on HCC treatment. Silmitasertib is an orally bioavailable, potent CK2 inhibitor with a direct role in DNA damage repair and is in clinical trials for other cancers. In this study, we planned to repurpose these existing drugs on HCC treatment. We observed a stronger antiproliferative effect of these two combined drugs on HCC cells generated from different etiologies as compared to the single treatment. Global RNA-seq analyses revealed a decrease in the expression of G2/M cell cycle transition genes in HCC cells following combination treatment, suggesting G2 phase cell arrest. We observed G2/M cell cycle phase arrest in HCC cells upon combination treatment compared to the single-treated or vehicle-treated control cells. The downregulation of CCNA2 and CDC25C following combination therapy further supported the observation. Subsequent analyses demonstrated that combination treatment inhibited 70 kDa ribosomal protein S6 kinase (p70S6K) phosphorylation, and increased Bim expression. Apoptosis of HCC cells were accompanied by increased poly (ADP-ribose) polymerase cleavage and caspase-9 activation. Next, we observed that a combination therapy significantly delayed the progression of HCC xenograft growth as compared to vehicle control. Together, our results suggested combining cabozantinib and silmitasertib would be a promising treatment option for HCC.