Reduced Cell Growth Research Articles

Nanomedicine potential of Cymbopogon citratus Linn. –Biogenic synthesized silver nanoparticles: A study on antimicrobial and anticancer efficacy

Green synthesis methods for making nanoparticles using plant extracts have gained considerable attention in recent years, particularly because of their potential applications in nanomedicine. Plant biosynthesized nanoparticles have shown noteworthy biomedical uses in comparison. The silver nanoparticle (AgNP) synthesized using extracts from the leaves and flowers of Cymbopogon citratus Linn was investigated for its antibacterial and anticancer properties. The biosynthesized AgNPs were characterized using UV–Vis, FTIR, DLS, EDX and SEM. The presence of alcohol, alkene, and phytochemicals in the AgNPs was confirmed using FTIR analysis. The investigation using SEM with EDX spectroscopy confirmed that the AgNPs were both pure and in the form of nanocrystals. Furthermore, AgNPs demonstrated significant antibacterial activity by efficiently suppressing bacterial growth. The biosynthesized AgNPs exhibited a concentration-dependent reduction in the lung cancer-A549 cell growth. The ethanolic extracts of C. citratus flower-synthesized AgNPs contain a wide range of phytochemical constituents. These components have been shown to effectively modulate antibacterial and anticancer activities, superior tothe effects of leaf extracts synthesized AgNPs. Consequently, additional research is required to investigate the potential biomedical applications of these biosynthesized AgNPs.

CSIG-33. CERAMIDE-1-PHOSPHATE/CERK ARE REGULATORS OF ETMR GROWTH AND POTENTIAL THERAPEUTIC TARGETS

Abstract Embryonal tumor with multilayered rosettes (ETMR) is a highly aggressive CNS neoplasm which occurs almost exclusively in infants and is associated with an extremely poor prognosis. To identify functional signaling lipids that contribute to the aggressive nature of ETMR and that can be targeted therapeutically, we carried out mass spectrometry imaging on human ETMR patient samples, the patient-derived cell line BT183, and normal neural stem cells. We identified an accumulation of ceramide-1-photphate (C1P) within the rapidly proliferating embryonal tumor cells in patient samples and the cell model. We also detected high accumulation of C1P within the aberrant vascular proliferations in patient samples. Ceramide-1-phosphate is a pleiotropic bioactive signaling lipid that controls cell fate. C1P and its synthesizing enzyme, ceramide kinase (CERK), are known mitogens that have been shown to regulate cell proliferation in several non-CNS cancers. C1P is known to mediate the upregulation of PI3K/Akt/mTOR, MAPK/MEK/ERK1/2, Rho kinase, JNK, to promote cell survival and migration. After spatially mapping C1P accumulation in patient samples and our in vitro 3D models, we next carried out IHC to correlate lipid accumulation with its synthesizing enzyme, CERK. CERK was found to be abundantly accumulated in both endothelial and tumor cells within the tumor microenvironment of patient samples. Western blot analysis of CERK demonstrated a significant increase in the ETMR 3D tumorspheres compared to the NSC neurospheres. Treatment of the ETMR 3D tumorspheres with the CERK inhibitor, NVP-231, potently reduced cell growth and viability. Western blot analysis of ETMR tumorspheres at 8 and 24 hours post-treatment demonstrated a time-dependent decrease in N-MYC and a subsequent increase in p53. Studies are ongoing to validate these findings in vivo and to elucidate the signaling pathways that C1P/CERK regulate in both the vascular and tumor cells in ETMR.

MiR-203-3p promotes senescence of mouse bone marrow mesenchymal stem cells via downregulation of Pbk.

The senescence of bone marrow mesenchymal stem cells (BMSCs) contributes to the development of degenerative skeletal conditions. To date, the molecular mechanism resulting in BMSC senescence has not been fully understood. In this study, we identified a small non-coding RNA, miR-203-3p, the expression of which was elevated in BMSCs from aged mice. On the other hand, overexpression of miR-203-3p in BMSCs from young mice reduced cell growth and enhanced their senescence. Mechanistically, PDZ-linked kinase (PBK) is predicted to be the target of miR-203-3p. The binding of miR-203-3p to Pbk mRNA could decrease its expression, which in turn inhibited the ubiquitination-mediated degradation of p53. Furthermore, the intravitreal injection of miR-203-3p-inhibitor into the bone marrow cavity of aged mice attenuated BMSC senescence and osteoporosis in aged mice. Collectively, these findings suggest that targeting miR-203-3p to delay BMSC senescence could be a potential therapeutic strategy to alleviate age-related osteoporosis.

Effect of Acacia concinna Extract on Apoptosis Induction Associated with Endoplasmic Reticulum Stress and Modulated Intracellular Signaling Pathway in Human Colon HCT116 Cancer Cells.

Colorectal cancer (CRC) stands as one of the most prevalent cancer types and among the most frequent causes of cancer-related death globally. Acacia concinna (AC) is a medicinal and edible plant that exhibits a multitude of biological properties, including anticancer properties. This study aimed to investigate the impact of the AC extract on apoptosis induction and the underlying mechanisms associated with this effect in KRAS-mutated human colon HCT116 cells. The effect of AC extract on cell cytotoxicity was evaluated using MTT assay. Nuclear morphological changes were visualized with Hoechst 33342 staining, while mitochondrial membrane potential (MMP) was assessed via JC-1 staining. Flow cytometry was employed for cell cycle analysis, and intracellular ROS levels were determined using DCFH-DA staining. The results showed that HCT116 cells exposed to AC extract showed reduced cell growth and prompted apoptosis, as indicated by an increase in chromatin condensation, apoptotic bodies, the sub-G1 apoptotic cell population, and disrupted MMP. Expression levels of apoptosis mediator proteins determined by Western blot analysis showed an increase in pro-apoptotic proteins (Bak and Bax) while decreasing anti-apoptotic proteins (Bcl-2, Bcl-xL, and Mcl-1), leading to caspase-7 activation and PARP inactivation. AC extract was also found to enhance intracellular reactive oxygen species (ROS) levels and stimulate endoplasmic reticulum (ER) stress. Furthermore, AC extract increases the phosphorylation of ERK1/2, p38, and c-Jun while downregulating PI3K, Akt, β-catenin, and their downstream target proteins. These results demonstrate that AC extract could inhibit cancer cell growth via ROS-induced ER stress associated with apoptosis and regulate the MAPK, PI3K/Akt, and Wnt/β-catenin signaling pathways in HCT116 cells. Therefore, AC extract may be a novel candidate for natural anticancer resources for colon cancer treatment.

BOLA family genes are the drivers and potential biomarkers of survival in kidney renal clear cell carcinoma patients.

To analyze the diagnostic and prognostic potential of the BOLA gene family in kidney renal clear cell carcinoma (KIRC). This study is an observational study. The whole study was carried out at Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia from January to November 2023. As it involves in silico and in vitro methods, ethical consent was not required. Various in silico and molecular experimental techniques were employed in this study. Significant up-regulation and hypomethylation of BOLA1, BOLA2, and BOLA3 were observed across 12 KIRC cell lines. Retrospective analysis of the cancer genome atlas program (TCGA)-KIRC cohorts confirmed hypomethylation of these genes in KIRC tissues. The cBioPortal analysis showed minimal genetic alterations, with amplification being the most common. Kaplan-Meier plotter data revealed that high BOLA1, BOLA2, and BOLA3 expression correlated with shorter overall survival and relapse-free survival in KIRC. Tumor-immune system interactions database analysis linked BOLA1 expression to immune and molecular subtypes. Gene silencing of BOLA1, BOLA2, and BOLA3 in 786-0 cells reduced cell growth and proliferation, enhancing wound healing capacity. BOLA genes may serve as diagnostic and prognostic markers in KIRC, offering insights into therapeutic targets and disease progression.

Fostamatinib Inhibits the Proliferation of Ovarian Cancer Cells Through Apoptosis Induction.

Ovarian cancer remains a significant challenge due to its high mortality rate and poor prognosis, especially in advanced stages. Despite treatment advancements, issues with resistance and recurrence persist, highlighting the urgent need for new and effective therapies. This study aimed to evaluate fostamatinib, an oral spleen tyrosine kinase inhibitor initially developed for autoimmune diseases, as a potential treatment for ovarian cancer. The effects of fostamatinib on ovarian cancer cell lines were assessed using WST-1 assays for cell proliferation. Apoptosis was evaluated through TUNEL assays, DNA fragmentation analysis, and flow cytometry. Western blot analysis was used to detect cleavage of apoptotic proteins, including caspase-3 and PARP, and flow cytometry analyzed cell cycle changes. Fostamatinib treatment resulted in a dose- and time-dependent reduction in ovarian cancer cell growth and induced apoptosis, as indicated by increased TUNEL-positive cells, DNA fragmentation, and rises in both early and late apoptosis. Western blot analysis showed increased cleavage of apoptotic proteins, including caspase-3 and PARP. Flow cytometry also demonstrated an increase in the sub-G1 phase of the cell cycle, further supporting apoptosis induction. Fostamatinib, by inhibiting cell proliferation and inducing apoptosis, shows promise as a repurposed therapeutic agent for ovarian cancer, potentially offering a new approach to improve patient outcomes.

DYRK1A interacts with the tuberous sclerosis complex and promotes mTORC1 activity

DYRK1A, a ubiquitously expressed kinase, is linked to the dominant intellectual developmental disorder, microcephaly, and Down syndrome in humans. It regulates numerous cellular processes such as cell cycle, vesicle trafficking, and microtubule assembly. DYRK1A is a critical regulator of organ growth; however, how it regulates organ growth is not fully understood. Here, we show that the knockdown of DYRK1A in mammalian cells results in reduced cell size, which depends on mTORC1. Using proteomic approaches, we found that DYRK1A interacts with the tuberous sclerosis complex (TSC) proteins, namely TSC1 and TSC2, which negatively regulate mTORC1 activation. Furthermore, we show that DYRK1A phosphorylates TSC2 at T1462, a modification known to inhibit TSC activity and promote mTORC1 activity. We also found that the reduced cell growth upon knockdown of DYRK1A can be rescued by overexpression of RHEB, an activator of mTORC1. Our findings suggest that DYRK1A inhibits TSC complex activity through inhibitory phosphorylation on TSC2, thereby promoting mTORC1 activity. Furthermore, using the Drosophila neuromuscular junction as a model, we show that the mnb, the fly homologs of DYRK1A, is rescued by RHEB overexpression, suggesting a conserved role of DYRK1A in TORC1 regulation.

DYRK1A interacts with the tuberous sclerosis complex and promotes mTORC1 activity.

DYRK1A, a ubiquitously expressed kinase, is linked to the dominant intellectual developmental disorder, microcephaly, and Down syndrome in humans. It regulates numerous cellular processes such as cell cycle, vesicle trafficking, and microtubule assembly. DYRK1A is a critical regulator of organ growth; however, how it regulates organ growth is not fully understood. Here, we show that the knockdown of DYRK1A in mammalian cells results in reduced cell size, which depends on mTORC1. Using proteomic approaches, we found that DYRK1A interacts with the tuberous sclerosis complex (TSC) proteins, namely TSC1 and TSC2, which negatively regulate mTORC1 activation. Furthermore, we show that DYRK1A phosphorylates TSC2 at T1462, a modification known to inhibit TSC activity and promote mTORC1 activity. We also found that the reduced cell growth upon knockdown of DYRK1A can be rescued by overexpression of RHEB, an activator of mTORC1. Our findings suggest that DYRK1A inhibits TSC complex activity through inhibitory phosphorylation on TSC2, thereby promoting mTORC1 activity. Furthermore, using the Drosophila neuromuscular junction as a model, we show that the mnb, the fly homologs of DYRK1A, is rescued by RHEB overexpression, suggesting a conserved role of DYRK1A in TORC1 regulation.

Pharmacological targeting of CBX7 alters the epigenetic landscape and induces differentiation of leukemic cells

AbstractSelf-renewal of leukemic cells results in the accumulation of dysfunctional blood cells and suppression of normal hematopoiesis. The polycomb group protein chromobox 7 (CBX7) is an epigenetic regulator that represses genes required for differentiation and cell cycle arrest and thereby promotes self-renewal. Because leukemic cells are highly self-renewing, we tested whether pharmacological targeting of CBX7 would reduce self-renewal and induce differentiation of human leukemic cells. We found that existing and newly developed CBX7 inhibitors derepress the epigenome, resulting in reduced ubiquitination of histone 2A and reduced binding of CBX7 to its target genes. This led to reduced cell growth, increased differentiation of leukemic cells in vitro, and delayed engraftment of primary leukemic cells in xenotransplant models. Therefore, pharmacological targeting of CBX7 constitutes a novel therapeutic approach for leukemia.

Repurposing Nitazoxanide for Potential Treatment of Rare Disease Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare genetic lung disease. Unfortunately, treatment with the mTORC1 inhibitor Rapamycin only slows disease progression, and incomplete responses are common. Thus, there remains an urgent need to identify new targets for the development of curative LAM treatments. Nitazoxanide (NTZ) is an orally bioavailable antiprotozoal small molecule drug approved for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum in children and adults, with a demonstrated mTORC1 inhibitory effect in several human cell lines. NTZ’s excellent safety profile characterized by its more than 20 years of clinical use makes it a promising candidate for repurposing. Our rationale for this study was to further investigate NTZ’s effect using in vitro and in vivo LAM models and to elucidate the underlying molecular mechanism beyond mTORC1 inhibition. For this purpose, we investigated cell proliferation, cell viability, and changes in protein phosphorylation and expression in primary human cell cultures derived from LAM lung samples before translating our results into a syngeneic mouse model utilizing Tsc2-null cells. NTZ reduced cell growth for all tested cell lines at a dose of about 30 µM. Lower doses than that had no effect on cell viability, but doses above 45 µM lowered the viability by about 10 to 15% compared to control. Interestingly, our western blot revealed no inhibition of mTORC1 and only a mild effect on active ß-Catenin. Instead, NTZ had a pronounced effect on reducing pAkt. In the mouse model, prophylactic NTZ treatment via the intraperitoneal and oral routes had some effects on reducing lung lesions and improving body weight retention, but the results remain inconclusive.

Quercetin 7-rhamnoside from Sorbaria sorbifolia exerts anti-hepatocellular carcinoma effect via DHRS13/apoptotic pathway

BackgroundPrevious research demonstrated the effects of Sorbaria sorbifolia (SS) in combating hepatocellular carcinoma (HCC). Despite SS's proven efficacy in treating HCC, the precise bioactive constituents contributing to its therapeutic benefits, along with the mechanisms behind them, warrant further exploration. PurposeThe objective of our study was to illuminate the possible elements, targets, and modulatory pathways employed by specific bioactive components in SS for HCC treatment. Study designUsing UPLC-Q-TOF-MS to analyze and quantify the bioactive constituents in the SS sample. By literature review, we gathered potential chemical constituents of SS. We used network pharmacology approaches to identify HCC-related targets of SS components, with an emphasis on core targets. To examine the core targets' importance in HCC biological processes, bioinformatics methods were utilized. Finally, molecular docking, MD simulations, and CESTA were employed to screen SS active ingredients capable of stably binding with core targets. To verify the anti-HCC effectiveness of these active components, we conducted several cellular experiments, including CCK8, wound healing, transwell, cell cycle, and apoptosis assays, as well as animal experiments like zebrafish HepG2 cell xenotransplantation, apoptosis assays, and HE staining. We also used lentivirus transfection to modulate core protein expression in HepG2 cells, creating cell models. Further cellular tests were performed to evaluate the ability of SS active ingredients to exert anti-HCC effects by interacting with the core protein to induce apoptosis. Finally, Western Blot and ELISA experiments were carried out to track changes in core protein and apoptosis-related pathway proteins after SS active ingredient treatment ResultsOur study identified 50 components in SS and 119 HCC-related target genes, with DHRS13 emerging as a core target. Further bioinformatics analysis indicated that DHRS13 expression in HCC patients correlated with prognosis and apoptotic pathways. Molecular docking revealed 20 active SS constituents effectively binding to DHRS13, MD simulations and CESTA pinpointed Quercetin 7-rhamnoside (Q7R) as the most stable binder. In-vitro and in-vivo tests verified Q7R's anti-HCC properties. Lentivirus transfection results showed that knockdown DHRS13 led to reduced cell growth and increased apoptosis, while overexpression DHRS13 led to increase cell growth and decrease apoptosis. Remarkably, our experiments found that Q7R acts as an inhibitor of DHRS13 and can reverse the suppressed apoptosis and excessive HCC proliferation caused by DHRS13 overexpression. ConclusionElevated DHRS13 expression contributes to HCC progression. Q7R effectively downregulates DHRS13, encouraging apoptosis and impeding HCC growth. As a result, Q7R shows potential as a therapeutic agent for HCC treatment, targeting the apoptotic pathway through DHRS13 regulation.

Novel Pannexin 1 isoform is increased in cancer.

Pannexin 1 (PANX1) is upregulated in many cancers, where its activity and signalling promote tumorigenic properties. Here, we report a novel ∼25 kDa isoform of human PANX1 (hPANX1-25K) which lacks the N-terminus and was detected in several human cancer cell lines including melanoma, osteosarcoma, breast cancer and glioblastoma multiforme. This isoform was increased upon hPANX1 CRISPR/Cas9 deletion targeting the first exon near M1, suggesting a potential alternative translation initiation (ATI) site. hPANX1-25K was confirmed to be a hPANX1 isoform via mass spectrometry, can be N-linked glycosylated at N254, and can interact with both β-catenin and full length hPANX1. A double deletion of hPANX1 and hPANX1-25K reduces cell growth and viability in cancer cells. hPANX1-25K is prevalent throughout melanoma progression, and its levels are increased in squamous cell carcinoma cells and patient-derived tumours, compared to keratinocytes and normal skin, indicating that it may be differentially regulated in normal and cancer cells.

Separable cell cycle arrest and immune response elicited through pharmacological CDK4/6 and MEK inhibition in RASmut disease models.

The combination of CDK4/6 and MEK inhibition as a therapeutic strategy has shown promise in various cancer models, particularly in those harboring RAS mutations. An initial high-throughput drug screen identified a high synergy between the CDK4/6 inhibitor palbociclib and the MEK inhibitor trametinib when used in combination in soft tissue sarcomas. In RAS mutant models, combination treatment with palbociclib and trametinib induced significant G1 cell cycle arrest, resulting in a marked reduction in cell proliferation and growth. CRISPR-mediated RB1 depletion resulted in a decreased response to CDK4/6 and MEK inhibition, which was validated in both cell culture and xenograft models. Beyond its cell cycle inhibitory effects, pathway enrichment analysis revealed the robust activation of interferon pathways upon CDK4/6 and MEK inhibition. This induction of gene expression was associated with the upregulation of retroviral elements. The TBK1(TANK-binding kinase 1) inhibitor GSK8612 selectively blocked the induction of interferon-related genes induced by palbociclib and trametinib treatment, and highlighted the separable epigenetic responses elicited by combined CDK4/6 and MEK inhibition. Together, these findings provide key mechanistic insights into the therapeutic potential of CDK4/6 and MEK inhibition in soft tissue sarcoma.

Potential effect of monolaurin and nisin on the growth of three aerobic spore-forming bacteria isolated from Tunisian milk

Antibacterial capacities of monolaurin and nisin on the growth of vegetative cells of three sporeforming bacteria isolated from cow milk collected from Tunisia (Terribacillus aidingensis, Bacillus sporothermodurans and Paenibacillus sp and) were evaluated. Nisin or monolaurin, at different concentrations, can inhibit the growth of three Bacillus. 500 IU/mL and 25 μg/mL corresponded to the minimum inhibitory concentrations of nisin and monolaurin, respectively. The growth of the tested species in the presence of sub-lethal concentrations of monolaurin and nisin was monitored in UHT milk for 7 days at three different temperatures (4°C, 37°C and 25°C). Nisin (250 IU/mL) was able to induce an immediate reduction (after 3 h of incubation at 4°C) of Bacillus species growth (5 log for B. sporothermodurans, 4 log for Paenibacillus sp and 3.2 log for T. aidingensis). Also, monolaurin (25 µg/mL) reduce the growth, at 4°C of B. sporothermodurans by 5 log, Paenibacillus sp by 3 log and T. aidingensis by 4 log, after 3 h of incubation. In the presence of nisin or monolaurin, it can be observed a low reduction in cell growth followed by a rapid regrowth which can attenuate 10 log, at 37°C and 25°C. The obtained data elucidate the potency of nisin and monolaurin, and the application of these antimicrobial agents at low temperatures (4°C) to decontaminate any product from these spoilage bacteria.

Abstract A062 Therapeutic targeting of the SAGA KAT module impairs MYCN-amplified neuroblastoma growth through reduction of the MYCN oncogenic gene expression program

Abstract Pediatric cancers are frequently driven by genomic alterations that result in aberrant transcription factor activity. While direct targeting of transcription factors is difficult, one method to circumvent this problem is to target co-factors and chromatin complexes that are necessary for their oncogenic function. To evaluate protein complex dependencies enriched in MYCN-amplified neuroblastoma, a disease of dysregulated development driven by aberrant expression of an oncogenic expression program, we curated a list of protein complexes using the CORUM database and mined the Dependency Map using single sample gene set enrichment analysis. This analysis identified the KAT module of the transcriptional coactivator Spt-Ada-Gcn5-acetyltransferase (SAGA) complex as a selective dependency in MYCN-amplified neuroblastoma. Loss of SAGA complex activity in neuroblastoma through both genetic knockout and induced protein degradation of the lysine acetyltransferase (KAT) module subunit TADA2B resulted in a global reduction of histone lysine acetylation and impaired neuroblastoma cell growth. Genetic knockout of TADA2B did not impair the growth of pediatric sarcoma cell lines, suggesting that SAGA loss-of-function is not broadly deleterious. Furthermore, SAGA loss-of-function reduced MYCN binding to chromatin, resulting in suppression of the MYCN-driven gene expression program and impaired cell cycle progression. Importantly, the SAGA complex is pharmacologically targetable in vitro and in vivo with GSK-699, a PROTAC that induces proteolysis of both KAT2A and KAT2B paralogs. As observed with genetic knockout studies, loss of SAGA activity through KAT2A/B degradation reduced the MYCN-driven transcriptional signature and impaired cell cycle progression. Our findings expand our understanding of the chromatin complexes that maintain the oncogenic transcriptional state in MYCN-amplified neuroblastoma and suggest therapeutic potential for inhibitors of SAGA KAT activity in MYCN-amplified neuroblastoma. Citation Format: Nathaniel W. Mabe, Clare F. Malone, Alexandra B. Forman, Gabriela Alexe, Kathleen L. Engel, Ying-Jiun C. Chen, Melinda Soeung, Silvi Salhotra, Allen Basanthakumar, Bin Liu, Sharon YR Dent, Kimberly Stegmaier. Therapeutic targeting of the SAGA KAT module impairs MYCN-amplified neuroblastoma growth through reduction of the MYCN oncogenic gene expression program [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pediatric Cancer Research; 2024 Sep 5-8; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl):Abstract nr A062.

The Phyllosphere Microbiome in Tsuga canadensis: Relationships with Resistance to the Insect Adelges tsugae and Effects of the Pesticide Dinotefuran

Tsuga canadensis (eastern hemlock) is an important tree species in North America, but it has been subject to threats from invasive insects such as Adelges tsugae (hemlock woolly adelgid). A. tsugae is native to Asia, and Tsuga species from Asia are typically resistant to this insect. In this study, we examined the phyllosphere microbiome of two hemlock species native to North America and susceptible to A. tsugae ( T. canadensis and T. caroliniana) as well as two species native to Asia and resistant to A. tsugae ( T. chinensis and T. diversifolia). Because pesticide application is often used to treat native Tsuga species impacted by A. tsugae, we also examined the response of the microbiome and overall plant physiology to the pesticide dinotefuran in T. canadensis. We found significant differences in the bacterial and fungal microbiome among the four species of Tsuga. Dinotefuran also significantly affected bacterial communities, but not fungal communities, of T. canadensis. The genus Methylobacterium, which uses methanol produced during plant cell elongation and growth, was a significant indicator of trees not subject to dinotefuran. This suggests that dinotefuran may have reduced cell growth in treated trees. Despite changes in the microbiome, dinotefuran application did not significantly affect plant physiology; however, the coefficient of variation in dinotefuran-treated trees was larger than that in non-treated trees. Our results suggest that the microbiome could play a role in mediating insect resistance in Tsuga species and that pesticide application could affect the phyllosphere microbiome, with implications for plant growth and resistance. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

SPRED3 regulates the NF-κB signaling pathway in thyroid cancer and promotes the proliferation

SPRED3 (Sprouty-related EVH1 domain containing 3) mutants are depicted in various cancers, however, nothing is known about its biofunction in thyroid cancer (THCA). Bioinformatic analyses were conducted to ascertain the level of SPRED3 expression in THCA tissues and its importance in the prognosis of THCA patients. Flag-SPRED3 plasmid and SPRED3-knockout vector were developed to overexpress or deplete the SPRED3 expression in THCA cells. The function of SPRED3 on THCA cell proliferation was examined using the colony formation assay and CCK8 assay. The effect of SPRED3 expression on the transcriptional activity of NF-κB was also examined using luciferase reporter assays. High SPRED3 expression was associated with unfavorable clinical outcomes, advanced tumor characteristics, and traditional molecular markers of papillary thyroid cancer in THCA patients. Genetic analysis revealed differences in mutation rates in key genes between SPRED3-high and SPRED3-low THCA cases. It is also revealed that SPRED3 influenced the immune microenvironment, with increased stromal and immune scores and altered immune cell infiltration. Functionally, SPRED3 overexpression enhanced THCA cell viability and colony formation, while its depletion reduced cell growth and proliferation. In vivo experiments in mice confirmed the inhibitory effect of SPRED3 depletion on tumor growth. Mechanically, we found that SPRED3 activated the NF-κB signaling. For the first time, we found that SPRED3 promotes THCA cell proliferation via the NF-κB signaling pathway. This finding may provide insight into SPRED3’s prognostic potential in thyroid cancer and provide the rationale for SPRED3-targeted druggable interventions.

BET inhibitors (BETi) influence oxidative phosphorylation metabolism by affecting mitochondrial dynamics leading to alterations in apoptotic pathways in triple-negative breast cancer (TNBC) cells.

Repressing BET proteins' function using bromodomain inhibitors (BETi) has been shown to elicit antitumor effects by regulating the transcription of genes downstream of BRD4. We previously showed that BETi promoted cell death of triple-negative breast cancer (TNBC) cells. Here, we proved that BETi induce altered mitochondrial dynamics fitness in TNBC cells falling in cell death. We demonstrated that BETi treatment downregulated the expression of BCL-2, and proteins involved in mitochondrial fission and increased fused mitochondria. Impaired mitochondrial fission affected oxidative phosphorylation (OXPHOS) inducing the expression of OXPHOS-related genes, SDHa and ATP5a, and increased cell death. Consistently, the amount of mitochondrial DNA and mitochondrial membrane potential (∆Ψm) increased in BETi-treated cells compared to control cells. Lastly, BETi in combination with Metformin reduced cell growth. Our results indicate that mitochondrial dynamics and OXPHOS metabolism support breast cancer proliferation and represent novel BETi downstream targets in TNBC cells.

DNMT3A loss drives a HIF-1-dependent synthetic lethality to HDAC6 inhibition in non-small cell lung cancer

DNMT3A encodes a DNA methyltransferase involved in development, cell differentiation, and gene transcription, which is mutated and aberrant-expressed in cancers. Here, we revealed that loss of DNMT3A promotes malignant phenotypes in lung cancer. Based on the epigenetic inhibitor library synthetic lethal screening, we found that small-molecule HDAC6 inhibitors selectively killed DNMT3A-defective NSCLC cells. Knockdown of HDAC6 by siRNAs reduced cell growth and induced apoptosis in DNMT3A-defective NSCLC cells. However, sensitive cells became resistant when DNMT3A was rescued. Furthermore, the selectivity to HDAC6 inhibition was recapitulated in mice, where an HDAC6 inhibitor retarded tumor growth established from DNMT3A-defective but not DNMT3A parental NSCLC cells. Mechanistically, DNMT3A loss resulted in the upregulation of HDAC6 through decreasing its promoter CpG methylation and enhancing transcription factor RUNX1 binding. Notably, our results indicated that HIF-1 pathway was activated in DNMT3A-defective cells whereas inactivated by HDAC6 inhibition. Knockout of HIF-1 contributed to the elimination of synthetic lethality between DNMT3A and HDAC6. Interestingly, HIF-1 pathway inhibitors could mimic the selective efficacy of HDAC6 inhibition in DNMT3A-defective cells. These results demonstrated HDAC6 as a HIF-1-dependent vulnerability of DNMT3A-defective cancers. Together, our findings identify HDAC6 as a potential HIF-1-dependent therapeutic target for the treatment of DNMT3A-defective cancers like NSCLC.

Astilbin Induces Apoptosis in Oral Squamous Cell Carcinoma through p53 Reactivation and Mdm-2 Inhibition.

Oral squamous cell carcinoma (OSCC) is a frequently occurring malignancy in the head and neck region. The most commonly mutated gene in OSCC is the tumor suppressor gene p53 (TP53), linked to lower survival and treatment resistance in OSCC patients. Astilbin is a flavonoid amongst several herbal treatments with a variety of pharmacological actions mainly including antioxidant, anti-inflammatory, and anti-cancer characteristics. This study evaluated the effects of astilbin on proliferation of OSCC cell lines SCC90 and SCC4 (bearing a p53 mutation) in relevance to p53 and Mdm-2 pathways. Astilbin inhibited the proliferation of SCC4 and SCC90 cells in a dose- and time-dependent manner. The IC50 values for both the cell lines were about 75 μM for astilbin. A p53 activator (RITA) was used to determine the effects of astilbin on p53 activity, and the results demonstrated synergistic reduction in cell growth. However, when combined with pifithrin-α (a p53 inhibitor), astilbin demonstrated a strong inhibition of its response. Astilbin reduced the mitochondrial membrane potential in SCC4 cells, which is a sign of apoptotic activity. Astilbin decreased the amounts of Mdm-2 (negative regulator of p53) and increased the expression of the p53 gene and protein. In a p53-dependent manner, astilbin suppressed the ability of SCC4 cells to form colonies and heal wounds. This was followed by the induction of mitochondrial intrinsic apoptosis via the activation of caspases 9 and 3, cleavage of PARP, and the suppression of pro-apoptotic Bid. Astilbin-induced p53-mediated apoptosis in OSCC cells as herbal medicinal ingredients.