Browsing by Subject "mTOR"

Now showing 1 - 4 of 4
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    Betulinic acid isolated from Betula platyphylla induces apoptosis and reduces the mTOR/PI3K/AKT signaling pathway in endometrial cancer cells
    (2026) Ceren Oy; Mücahit Secme; Duygu Gok Yurtseven; Sema Serter Koçoğlu; Gözde Korkusuz Akçal; Biología Celular e Histología
    Endometrial cancer is one of the most common gynecological cancers worldwide, and an average of 42,000 women die each year. Chemotherapy, radiotherapy, and surgery are among the treatments available for endometrial cancer. Currently, drugs used for chemotherapy have had limited success in increasing the cure rate. Betulinic acid, a lupane-type triterpene widely found in the plant kingdom, has attracted attention for cancer treatment in recent years due to its ability to inhibit tumor growth and induce cell apoptosis. The aim of this study is to investigate the mTOR pathway-mediated anticancer effects of betulinic acid in human endometrial cancer cells. The effect of betulinic acid on Ishikawa cell viability was determined by the CCK-8 method. Its effect on the expression of genes involved in apoptosis and the mTOR pathway was assessed by real-time PCR. The effect on protein expression in the mTOR pathway was evaluated with immunohistochemistry and western blot, and the effects on apoptosis via Annexin V. Betulinic acid reduced Ishikawa endometrial cancer cell proliferation. Betulinic acid administration caused a significant decrease in Bcl2 (p=0.008) expression and increased caspase-8 (p=0.001) expression in Ishikawa cells. The results of Annexin V supported the idea that betulinic acid administration triggered apoptosis in Ishikawa cells. The mean rate of apoptotic cells in the betulinic acid group was 22±3.23%, while it was 2.31±0.2% in the control group (p=0.02). Betulinic acid caused a significant decrease in the expression of AKT1 (p=0.0001) and a significant increase in the expression of RAPTOR (p=0.00002). Betulinic acid administration also significantly percentage of p-PI3K, p-AKT, and p-mTOR-positive cells in Ishikawa cells was 89.39±5.19%, 74.84%±5.07, and 82.02%±6.14, respectively, in the control group. In the betulinic acid group, these values were 49.12± 19.12% (p=0.002), 44.46±7.39% (p<0.001), and 53.70±8.94% (p<0.001), respectively. This study showed that betulinic acid decreased Ishikawa cell proliferation, triggered apoptosis, and decreased mTOR signaling; thus, betulinic acid may be a potential anticancer agent for the treatment of endometrial cancer. decreased protein expression in the mTOR pathway. The
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    Open Access
    Flavonoids’ effects on Caenorhabditis elegans’ longevity, fat accumulation, stress resistance and gene modulation involve mTOR, SKN-1 and DAF-16
    (MDPI, 2021-03-12) Guerrero Rubio, María Alejandra; Hernández García, Samanta; Gandía Herrero, Fernando; García Carmona, Francisco; Bioquímica y Biología Molecular "A"
    Flavonoids are potential nutraceutical compounds present in diary food. They are considered health-promoting compounds and promising drugs for different diseases, such as neurological and inflammatory diseases, diabetes and cancer. Therefore, toxicological and mechanistic studies should be done to assert the biological effects and identify the molecular targets of these compounds. In this work we describe the effects of six structurally-related flavonoids—baicalein, chrysin, scutellarein, 6-hydroxyflavone, 6,7-dihydroxyflavone and 7,8-dihydroxyflavone—on Caenorhabditis elegans’lifespan and stress resistance. The results showed that chrysin, 6-hydroxyflavone and baicalein prolonged C. elegans’ lifespan by up to 8.5%, 11.8% and 18.6%, respectively. The lifespan extensions caused by these flavonoids are dependent on different signaling pathways. The results suggested that chrysin’s effects are dependent on the insulin signaling pathway via DAF-16/FOXO. Baicalein and 6-hydroxyflavone’s effects are dependent on the SKN-1/Nfr2 pathway. In addition, microarray analysis showed that baicalein downregulates important age-related genes, such as mTOR and PARP.
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    Mammalian target of rapamycin complex (mTOR) pathway modulates blood-testis barrier (BTB) function through F-actin organization and gap junction
    (2016) Li, Nan; Yan Cheng, C.
    mTOR (mammalian target of rapamycin) is one of the most important signaling molecules in mammalian cells which regulates an array of cellular events, ranging from cell metabolism to cell proliferation. Based on the association of mTOR with the core component proteins, such as Raptor (regulatoryassociated protein of mTOR) or Rictor (rapamycinintensive companion of mTOR), mTOR can become the mTORC1 (mammalian target of rapamycin complex 1) or mTORC2, respectively. Studies have shown that during the epithelial cycle of spermatogenesis, mTORC1 promotes remodeling and restructuring of the bloodtestis barrier (BTB) in vitro and in vivo, making the Sertoli cell tight junction (TJ)-permeability barrier “leaky”; whereas mTORC2 promotes BTB integrity, making the Sertoli cell TJ-barrier “tighter”. These contrasting effects, coupled with the spatiotemporal expression of the core signaling proteins at the BTB that confer the respective functions of mTORC1 vs. mTORC2 thus provide a unique mechanism to modulate BTB dynamics, allowing or disallowing the transport of biomolecules and also preleptotene spermatocytes across the immunological barrier. More importantly, studies have shown that these changes to BTB dynamics conferred by mTORC1 and mTORC2 are mediated by changes in the organization of the actin microfilament networks at the BTB, and involve gap junction (GJ) intercellular communication. Since GJ has recently been shown to be crucial to reboot spermatogenesis and meiosis following toxicant-induced aspermatogenesis, these findings thus provide new insightful information regarding the integration of mTOR and GJ to regulate spermatogenesis.
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    PCR Array technology in biopsy samples identifies up-regulated mTOR pathway genes as potential rejection biomarkers after kidney transplantation
    (Frontiers Media, 2021-02-17) Bernardo, María Victoria; Alfaro, Rafael; Martínez Banaclocha, Helios; Galián, Jose Antonio; Jiménez Coll, Víctor; Boix, Francisco; Mrowiec, Anna; Salmeron, Diego; Botella, Carmen; Parrado, Antonio; Moya Quiles, María Rosa; Minguela, Alfredo; Llorente, Santiago; Peña Moral, Jesús de la; Muro, Manuel; Legaz Pérez, Isabel; Ciencias Sociosanitarias
    Background: Antibody-mediated rejection (AMR) is the major cause of kidney transplant rejection. The donor-specific human leukocyte antigen (HLA) antibody (DSA) response to a renal allograft is not fully understood yet. mTOR complex has been described in the accommodation or rejection of transplants and integrates responses from a wide variety of signals. The aim of this study was to analyze the expression of the mTOR pathway genes in a large cohort of kidney transplant patients to determine its possible influence on the transplant outcome. Methods: A total of 269 kidney transplant patients monitored for DSA were studied. The patients were divided into two groups, one with recipients that had transplant rejection (+DSA/+AMR) and a second group of recipients without rejection (+DSA/–AMR and –DSA/–AMR, controls). Total RNA was extracted from kidney biopsies and reverse transcribed to cDNA. Human mTOR-PCR array technology was used to determine the expression of 84 mTOR pathway genes. STRING and REVIGO software were used to simulate gene to gene interaction and to assign a molecular function. Results: The studied groups showed a different expression of the mTOR pathway related genes. Recipients that had transplant rejection showed an over-expressed transcript (≥5-fold) of AKT1S1, DDIT4, EIF4E, HRAS, IGF1, INS, IRS1, PIK3CD, PIK3CG, PRKAG3, PRKCB (>12-fold), PRKCG, RPS6KA2, TELO2, ULK1, and VEGFC, compared with patients that did not have rejection. AKT1S1 transcripts were more expressed in +DSA/–AMR biopsies compared with +DSA/+AMR. The main molecular functions of up-regulated gene products were phosphotransferase activity, insulin-like grown factor receptor and ribonucleoside phosphate binding. The group of patients with transplant rejection also showed an under-expressed transcript (≥5-fold) of VEGFA (>15-fold), RPS6, and RHOA compared with the group without rejection. The molecular function of down-regulated gene products such as protein kinase activity and carbohydrate derivative binding proteins was also analyzed. Conclusions: We have found a higher number of over-expressed mTOR pathway genes than under-expressed ones in biopsies from rejected kidney transplants (+DSA/+AMR) with respect to controls. In addition to this, the molecular function of both types of transcripts (over/under expressed) is different. Therefore, further studies are needed to determine if variations in gene expression profiles can act as predictors of graft loss, and a better understanding of the mechanisms of action of the involved proteins would be necessary.