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Transcriptomic analysis following polystyrene nanoplastic stress in the Pacific white shrimp, Litopenaeus vannamei

Zhu C, Liu G, Abdullah ALB, Han M, Jiang Q, Li Y

Fish Shellfish Immunol, 2023 Dec;143:109207.
PMID: 37923183 DOI: 10.1016/j.fsi.2023.109207

Plastics are widely produced for industrial and domestic applications due to their unique properties, and studies on the toxic effects of nanoplastics (NPs) on aquatic animals are essential. In this study, we investigated the transcriptomic patterns of Litopenaeus vannamei after NPs exposure. We found that the lysosome pathway was activated when after NPs exposure, with up-regulated DEGs, including glucocerebrosidase (GBA), hexosaminidase A (HEXA), sphingomyelin phosphodiesterase-1 (SMPD1), and solute carrier family 17 member 5 (SLC17A5). In addition, the PI3K-Akt signaling pathway was strongly affected by NPs, and the upstream genes of PI3K-Akt, including epidermal growth factor receptor (EGFR), integrin subunit beta 1 (ITGB1) and heat shock protein 90 (HSP90) were up-regulation. Other genes involved in lipogenesis, such as sterol regulatory element binding transcription factor 1 (SREBP-1c), fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD-1), were down-regulated. However, the contents of triglycerides (TG) and total cholesterol (TCH) in L. vanname hepatopancreas were reduced, which indicated that the ingestion of NPs led to the disturbance of hepatic lipid metabolism. What more, NPs treatment of L. vannamei also caused oxidative stress. In addition, NPs can damage part of the tissue structure and affect the physiological function of shrimps. The results of this study provide valuable ecotoxicological data to improve the understanding of the biological fate and effects of nanoplastics in L. vannamei.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics
Miltefosine suppression of Pten null T-ALL leukemia via β-catenin degradation through inhibition of pT308-Akt and TGFβ1/Smad3

Zhang Y, Lee S, Xu W

Biochem Biophys Res Commun, 2020 04 16;524(4):1018-1024.
PMID: 32063363 DOI: 10.1016/j.bbrc.2020.02.021

Pten deletion in the hematopoietic stem cells (HSC) causes a myeloproliferative disorder, which may subsequently develop into a T-cell acute lymphoblastic leukemia (T-ALL). β-catenin expression was dramatically increased in the c-KitmidCD3+Lin- leukemia stem cells (LSC) and was critical for T-ALL development. Therefore, the inactivation of β-catenin in LSC may have a potential to eliminate the LSC. In this study, we investigated the mechanism of enhancement of the β-catenin expression and subsequently used a drug to inactivate β-catenin expression in T-ALL. Western blot (WB) analysis revealed an increased level of β-catenin in the leukemic cells, but not in the pre-leukemic cells. Furthermore, the WB analysis of the thymic cells from different stages of leukemia development showed that increased expression of β-catenin was not via the pS9-GSK3β signaling, but was dependent on the pT308-Akt activation. Miltefosine (Hexadecylphosphocholine) is the first oral anti-Leishmania drug, which is a phospholipid agent and has been shown to inhibit the PI3K/Akt activity. Treatment of the PtenΔ/Δ leukemic mice with Miltefosine for different durations demonstrated that the pT308-Akt and the β-catenin expressions were inhibited in the leukemia blast cells. Miltefosine treatment also suppressed the TGFβ1/Smad3 signaling pathway. Analysis of TGFβ1 in the sorted subpopulations of the blast cells showed that TGFβ1 was secreted by the CD3+CD4- subpopulation and may exert effects on the subpopulations of both CD3+CD4+ and CD3+CD4- leukemia blast cells. When a TGFβR1 inhibitor, SB431542 was injected into the PtenΔ/Δ leukemic mice, the Smad3 and β-catenin expressions were down-regulated. On the basis of the results, we conclude that Miltefosine can suppress leukemia by degrading β-catenin through repression of the pT308-Akt and TGFβ1/Smad3 signaling pathways. This study demonstrates a possibility to inhibit Pten loss-associated leukemia genesis via targeting Akt and Smad3.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism
Fulltext Vitamins D and E Stimulate the PI3K-AKT Signalling Pathway in Insulin-Resistant SK-N-SH Neuronal Cells

Zaulkffali AS, Md Razip NN, Syed Alwi SS, Abd Jalil A, Abd Mutalib MS, Gopalsamy B, et al.

Nutrients, 2019 Oct 19;11(10).
PMID: 31635074 DOI: 10.3390/nu11102525

This study investigated the effects of vitamins D and E on an insulin-resistant model and hypothesized that this treatment would reverse the effects of Alzheimer's disease (AD) and improves insulin signalling. An insulin-resistant model was induced in SK-N-SH neuronal cells with a treatment of 250 nM insulin and re-challenged with 100 nM at two different incubation time (16 h and 24 h). The effects of vitamin D (10 and 20 ng/mL), vitamin E in the form of tocotrienol-rich fraction (TRF) (200 ng/mL) and the combination of vitamins D and E on insulin signalling markers (IR, PI3K, GLUT3, GLUT4, and p-AKT), glucose uptake and AD markers (GSK3β and TAU) were determined using quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The results demonstrated an improvement of the insulin signalling pathway upon treatment with vitamin D alone, with significant increases in IR, PI3K, GLUT3, GLUT4 expression levels, as well as AKT phosphorylation and glucose uptake, while GSK3β and TAU expression levels was decreased significantly. On the contrary, vitamin E alone, increased p-AKT, reduced the ROS as well as GSK3β and TAU but had no effect on the insulin signalling expression levels. The combination of vitamins D and E only showed significant increase in GLUT4, p-AKT, reduced ROS as well as GSK3β and TAU. Thus, the universal role of vitamin D, E alone and in combinations could be the potential nutritional agents in restoring the sensitivity of neuronal cells towards insulin and delaying the pathophysiological progression of AD.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics; Proto-Oncogene Proteins c-akt/metabolism*
Fulltext Tocotrienols and oxidative stress in ocytes and developing embryos

Yuhaniza Shafinie Kamsani, Mohd Hamim Rajikin

Journal of Clinical and Health Sciences, 2017;2:8-18.

This review summarizes the impact of tocotrienols (TCTs) as antioxidants in minimizing
oxidative stress (OS), particularly in embryos exposed to OS causing agents. OS level is
increased, for example, by nicotine, a major alkaloid content in cigarette, which is also a source
of exogenous reactive oxygen species (ROS). Increased nicotine-induced OS increases cell
stress response, which is a common trigger leading to embryonic cell death. Having more
profound anti-oxidative stress effects than its counterpart tocopherol, TCTs improve blastocyst
implantation, foetal growth, pregnancy outcome and survival of the neonates affected by
nicotine. In reversing cell developmental arrest caused by nicotine-induced OS, TCTs enhances
PDK-1 expression in the P13K/Akt pathway and permit embryonic development beyond the 4-
cell stage with the production of more morulae. At the cytoskeletal level, TCTs increase the
number of nicotine-induced apoptotic cells, through caspase 8 activation in the mitochondria.
TCTs facilitate rough endoplasmic reticulum (rER) stress-mediated apoptosis and autophagy,
resulting from nicotine-induced OS. Reduced vesicular population in TCT supplemented
oocytes on the other hand may suggest reduced secretion of apoptotic cell bodies thus probably
minimizing vesicular apoptosis during oocyte maturation. Further extensive research is
required to develop TCTs as a tool in specific therapeutic approaches to overcome the
detrimental effects of OS.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Fulltext Tocotrienols and oxidative stress in ocytes and developing embryos

Yuhaniza Shafinie Kamsani, Mohd Hamim Rajikin

Journal of Clinical and Health Sciences, 2017;2(2):8-18.
MyJurnal

This review summarizes the impact of tocotrienols (TCTs) as antioxidants in minimizing oxidative stress (OS), particularly in embryos exposed to OS causing agents. OS level is increased, for example, by nicotine, a major alkaloid content in cigarette, which is also a source of exogenous reactive oxygen species (ROS). Increased nicotine-induced OS increases cell stress response, which is a common trigger leading to embryonic cell death. Having more profound anti-oxidative stress effects than its counterpart tocopherol, TCTs improve blastocyst implantation, foetal growth, pregnancy outcome and survival of the neonates affected by nicotine. In reversing cell developmental arrest caused by nicotine-induced OS, TCTs enhances PDK-1 expression in the P13K/Akt pathway and permit embryonic development beyond the 4-cell stage with the production of more morulae. At the cytoskeletal level, TCTs increase the number of nicotine-induced apoptotic cells, through caspase 8 activation in the mitochondria. TCTs facilitate rough endoplasmic reticulum (rER) stress-mediated apoptosis and autophagy, resulting from nicotine-induced OS. Reduced vesicular population in TCT supplemented oocytes on the other hand may suggest reduced secretion of apoptotic cell bodies thus probably minimizing vesicular apoptosis during oocyte maturation. Further extensive research is required to develop TCTs as a tool in specific therapeutic approaches to overcome the detrimental effects of OS.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Molecular alterations of Ras-Raf-mitogen-activated protein kinase and phosphatidylinositol 3-kinase-Akt signaling pathways in colorectal cancers from a tertiary hospital at Kuala Lumpur, Malaysia

Yip WK, Choo CW, Leong VC, Leong PP, Jabar MF, Seow HF

APMIS, 2013 Oct;121(10):954-66.
PMID: 23992303 DOI: 10.1111/apm.12152

Molecular alterations in KRAS, BRAF, PIK3CA, and PTEN have been implicated in designing targeted therapy for colorectal cancer (CRC). The present study aimed to determine the status of these molecular alterations in Malaysian CRCs as such data are not available in the literature. We investigated the mutations of KRAS, BRAF, and PTEN, the gene amplification of PIK3CA, and the protein expression of PTEN and phosphatidylinositol 3-kinase (PI3K) catalytic subunit (p110α) by direct DNA sequencing, quantitative real-time PCR, and immunohistochemistry, respectively, in 49 CRC samples. The frequency of KRAS (codons 12, 13, and 61), BRAF (V600E), and PTEN mutations, and PIK3CA amplification was 25.0% (11/44), 2.3% (1/43), 0.0% (0/43), and 76.7% (33/43), respectively. Immunohistochemical staining demonstrated loss of PTEN protein in 54.5% (24/44) of CRCs and no significant difference in PI3K p110α expression between CRCs and the adjacent normal colonic mucosa (p = 0.380). PIK3CA amplification was not associated with PI3K p110α expression level, but associated with male cases (100% of male cases vs 56% of female cases harbored amplified PIK3CA, p = 0.002). PI3K p110α expression was significantly higher (p = 0.041) in poorly/moderately differentiated carcinoma compared with well-differentiated carcinoma. KRAS mutation, PIK3CA amplification, PTEN loss, and PI3K p110α expression did not correlate with Akt phosphorylation or Ki-67 expression. KRAS mutation, PIK3CA amplification, and PTEN loss were not mutually exclusive. This is the first report on CRC in Malaysia showing comparable frequency of KRAS mutation and PTEN loss, lower BRAF mutation rate, higher PIK3CA amplification frequency, and rare PTEN mutation, as compared with published reports.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics; Proto-Oncogene Proteins c-akt/metabolism
Overexpression of phospho-Akt correlates with phosphorylation of EGF receptor, FKHR and BAD in nasopharyngeal carcinoma

Yip WK, Leong VC, Abdullah MA, Yusoff S, Seow HF

Oncol Rep, 2008 Feb;19(2):319-28.
PMID: 18202777

The Akt pathway is one of the most common molecular alterations in various human malignancies. However, its involvement in nasopharyngeal carcinoma (NPC) tumorigenesis has not been well established. In this study, the status of Akt activation and expression of its upstream and downstream molecules was investigated in 64 NPC and 38 non-malignant nasopharyngeal tissues by immunohistochemistry. The hotspot mutations of PIK3CA, encoding the p110alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), were also determined in 25 of these NPC tissues. No hotspot mutations were found in any of the samples tested. Akt was activated in 27 (42.2%) and 23 (35.9%) NPCs, as indicated by p-Akt (Thr308) and p-Akt (Ser473) immunoreactivity, respectively. PTEN loss did not correlate statistically with activated Akt. However, a positive correlation was observed between activated Akt and phospho-epidermal growth factor receptor (p-EGFR), suggesting that the EGFR signaling might be one of the upstream regulators of the Akt pathway. The phosphorylation of forkhead (FKHR) and Bcl-2 associated death domain (BAD), but not mammalian target of rapamycin and glycogen synthase kinase-3beta, was significantly correlated with Akt activation. This implies that Akt promotes cell proliferation (as estimated by Ki-67) and survival, at least, through the inactivation of FKHR and BAD in NPC. Our data revealed that the EGFR/PI3K/Akt signaling pathway is important in NPC pathogenesis and that PIK3CA hotspot mutations are rare in NPC.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/analysis; Proto-Oncogene Proteins c-akt/metabolism*
Activation of phosphatidylinositol 3-kinase/Akt signaling by EGF downregulates membranous E-cadherin and β-catenin and enhances invasion in nasopharyngeal carcinoma cells

Yip WK, Seow HF

Cancer Lett, 2012 May 28;318(2):162-72.
PMID: 22182447 DOI: 10.1016/j.canlet.2011.12.018

Dysregulation of E-cadherin and β-catenin function in cell-cell adhesion is common in nasopharyngeal carcinoma (NPC) and correlates with metastatic disease. In this study, we examined the role of EGF-activated phosphatidylinositol 3-kinase (PI3K)-Akt signaling in E-cadherin and β-catenin regulation. We found that reduced membranous E-cadherin and β-catenin expression was positively correlated with Akt phosphorylation in NPC tissues. EGF treatment disrupted cell-cell adhesion and resulted in mesenchymal morphological features in NPC cell lines (TW01, TW04, and TW06). Western blot analysis showed that the E-cadherin protein level was partially reduced in TW04 cells only and the β-catenin levels were not considerably affected upon EGF treatment. In contrast, quantitative real-time RT-PCR showed that the E-cadherin, but not β-catenin, mRNA levels were markedly reduced by EGF in all cell lines. Immunofluorescent staining revealed that E-cadherin and β-catenin appeared to be markedly reduced on the cell surface and more localized in the cytoplasm. Inhibition of PI3K by LY294002 did not abolish the EGF-induced downregulation of E-cadherin protein or mRNA in TW04 cells but moderately increased the β-catenin protein level in TW01 cells and mRNA level in TW06 cells. However, LY294002 substantially restored or increased cell surface E-cadherin and β-catenin in all EGF-treated cell lines, in concordance with the inhibition of cell morphological changes. Moreover, LY294002 significantly blocked EGF-driven cell invasion, correlating with the elevation of membranous E-cadherin and β-catenin levels. In conclusion, EGF-induced epithelial-to-mesenchymal transition may not be only dependent on downregulation of E-cadherin protein/mRNA but also on mislocalization of E-cadherin and β-catenin. The mechanisms involved may be related, at least in part, to the PI3K-Akt pathway.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism*
Fulltext Cytotoxicity, regulation of apoptotic and anti-apoptotic gene expression by IL-27 in MCF-7 and MDA-MB-231 breast cancer cell lines

Yap Wei Boon, Shaktypreya Nadarajah, Nadiah Shidik, Noorjahan Banu Mohammed Alitheen

Jurnal Sains Kesihatan Malaysia, 2018;16(101):15-22.
MyJurnal

Breast cancer is one of the commonest cancers among women. Conventional therapies cause adverse side effects in patients. Cytokine immunotherapy such as interleukin-27 (IL-27) has been sought as an alternative cancer treatment in recent years. IL-27 has been shown to improve anticancer immunity and anti-angiogenesis in cancers, however, its effect on apoptotic and anti-apoptotic gene expression especially in breast cancers is yet to be explored. Cytotoxicity of IL-27 in non-cancerous (184b5) and cancerous (MCF-7 and MDA-MB-231) breast cell lines was first determined for 24-72 h in this study. The results indicated that IL-27 treatment did not retard 184b5 cell growth, however, did inhibit MCF-7 (48 h) and MDA-MB-231 (72 h) cell growth with IC50 at 442 and 457 ng/ml, respectively. Apoptotic (TRAIL, FADD, FAS, caspase-3 and caspase-8) and anti-apoptotic (BCL-2, AKT, and COX-2) genes were then amplified from untreated (control) and treated breast cancer cells and studied. TRAIL, caspase-3, caspase-8 gene expression was significantly (p < 0.05) upregulated in treated MCF-7 (442 ng/ml) and MDA-MB-231 (457 ng/ml) cells. Expression of FADD and FAS genes was not detected in both control and treated MCF-7 and MDA-MB-231 cells. COX-2 gene was also not expressed by MCF-7 cells, but reduced significantly (p < 0.05) in treated MDA-MB-231 cells. In MDA-MB-231 cells, IL-27 treatment seemed to slightly enhance the expression of AKT and BCL-2 genes which, on the other hand, was downregulated in treated MCF-7 cells. Conclusively, IL-27 is able to inhibit breast cancer cell growth and regulate apoptotic and anti-apoptotic gene expression in breast cancer cells.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Fulltext Catalpol Ameliorates Insulin Sensitivity and Mitochondrial Respiration in Skeletal Muscle of Type-2 Diabetic Mice Through Insulin Signaling Pathway and AMPK/SIRT1/PGC-1α/PPAR-γ Activation

Yap KH, Yee GS, Candasamy M, Tan SC, Md S, Abdul Majeed AB, et al.

Biomolecules, 2020 09 24;10(10).
PMID: 32987623 DOI: 10.3390/biom10101360

Catalpol was tested for various disorders including diabetes mellitus. Numerous molecular mechanisms have emerged supporting its biological effects but with little information towards its insulin sensitizing effect. In this study, we have investigated its effect on skeletal muscle mitochondrial respiration and insulin signaling pathway. Type-2 diabetes (T2DM) was induced in male C57BL/6 by a high fat diet (60% Kcal) and streptozotocin (50 mg/kg, i.p.). Diabetic mice were orally administered with catalpol (100 and 200 mg/kg), metformin (200 mg/kg), and saline for four weeks. Fasting blood glucose (FBG), HbA1c, plasma insulin, oral glucose tolerance test (OGTT), insulin tolerance test (ITT), oxygen consumption rate, gene (IRS-1, Akt, PI3k, AMPK, GLUT4, and PGC-1α) and protein (AMPK, GLUT4, and PPAR-γ) expression in muscle were measured. Catalpol (200 mg/kg) significantly (p < 0.05) reduced the FBG, HbA1C, HOMA_IR index, and AUC of OGTT whereas, improved the ITT slope. Gene (IRS-1, Akt, PI3k, GLUT4, AMPK, and PGC-1α) and protein (AMPK, p-AMPK, PPAR-γ and GLUT4) expressions, as well as augmented state-3 respiration, oxygen consumption rate, and citrate synthase activity in muscle was observed in catalpol treated mice. The antidiabetic activity of catalpol is credited with a marked improvement in insulin sensitivity and mitochondrial respiration through the insulin signaling pathway and AMPK/SIRT1/PGC-1α/PPAR-γ activation in the skeletal muscle of T2DM mice.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Fulltext The geranyl acetophenone tHGA attenuates human bronchial smooth muscle proliferation via inhibition of AKT phosphorylation

Yap HM, Lee YZ, Harith HH, Tham CL, Cheema MS, Shaari K, et al.

Sci Rep, 2018 11 09;8(1):16640.
PMID: 30413753 DOI: 10.1038/s41598-018-34847-0

Increased airway smooth muscle (ASM) mass is a prominent hallmark of airway remodeling in asthma. Inhaled corticosteroids and long-acting beta2-agonists remain the mainstay of asthma therapy, however are not curative and ineffective in attenuating airway remodeling. The geranyl acetophenone 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA), an in-house synthetic non-steroidal compound, attenuates airway hyperresponsiveness and remodeling in murine models of asthma. The effect of tHGA upon human ASM proliferation, migration and survival in response to growth factors was assessed and its molecular target was determined. Following serum starvation and induction with growth factors, proliferation and migration of human bronchial smooth muscle cells (hBSMCs) treated with tHGA were significantly inhibited without any significant effects upon cell survival. tHGA caused arrest of hBSMC proliferation at the G1 phase of the cell cycle with downregulation of cell cycle proteins, cyclin D1 and diminished degradation of cyclin-dependent kinase inhibitor (CKI), p27Kip1. The inhibitory effect of tHGA was demonstrated to be related to its direct inhibition of AKT phosphorylation, as well as inhibition of JNK and STAT3 signal transduction. Our findings highlight the anti-remodeling potential of this drug lead in chronic airway disease.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics; Proto-Oncogene Proteins c-akt/metabolism*
Fulltext Crosstalk Between Signaling Pathways Involved in the Regulation of Airway Smooth Muscle Cell Hyperplasia

Yap HM, Israf DA, Harith HH, Tham CL, Sulaiman MR

Front Pharmacol, 2019;10:1148.
PMID: 31649532 DOI: 10.3389/fphar.2019.01148

Increased ASM mass, primarily due to ASM hyperplasia, has been recognized as a hallmark of airway remodeling in asthma. Increased ASM mass is the major contributor to the airway narrowing, thus worsening the bronchoconstriction in response to stimuli. Inflammatory mediators and growth factors released during inflammation induce increased ASM mass surrounding airway wall via increased ASM proliferation, diminished ASM apoptosis and increased ASM migration. Several major pathways, such as MAPKs, PI3K/AKT, JAK2/STAT3 and Rho kinase, have been reported to regulate these cellular activities in ASM and were reported to be interrelated at certain points. This article aims to provide an overview of the signaling pathways/molecules involved in ASM hyperplasia as well as the mapping of the interplay/crosstalk between these major pathways in mediating ASM hyperplasia. A more comprehensive understanding of the complexity of cellular signaling in ASM cells will enable more specific and safer drug development in the control of asthma.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Dental stem cells as an alternative source for cardiac regeneration

Xin LZ, Govindasamy V, Musa S, Abu Kasim NH

Med Hypotheses, 2013 Oct;81(4):704-6.
PMID: 23932760 DOI: 10.1016/j.mehy.2013.07.032

Dental tissues contains stem cells or progenitors that have high proliferative capacity, are clonogenic in vitro and demonstrate the ability to differentiate to multiple type cells involving neurons, bone, cartilage, fat and smooth muscle. Numerous experiments have demonstrated that the multipotent stem cells are not rejected by immune system and therefore it may be possible to use these cells in allogeneic settings. In addition, these remarkable cells are easily abundantly available couple with less invasive procedure in isolating comparing to bone marrow aspiration. Here we proposed dental stem cells as candidate for cardiac regeneration based on its immature characteristic and propensity towards cardiac lineage via PI3-Kinase/Aktsignalling pathway.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism
Rapamycin synergizes cisplatin sensitivity in basal-like breast cancer cells through up-regulation of p73

Wong SW, Tiong KH, Kong WY, Yue YC, Chua CH, Lim JY, et al.

Breast Cancer Res Treat, 2011 Jul;128(2):301-13.
PMID: 20686837 DOI: 10.1007/s10549-010-1055-0

Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFβRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics; Proto-Oncogene Proteins c-akt/metabolism
Fulltext The Skeletal-Protecting Action and Mechanisms of Action for Mood-Stabilizing Drug Lithium Chloride: Current Evidence and Future Potential Research Areas

Wong SK, Chin KY, Ima-Nirwana S

Front Pharmacol, 2020;11:430.
PMID: 32317977 DOI: 10.3389/fphar.2020.00430

Lithium, the lightest natural-occurring alkali metal with an atomic number of three, stabilizes the mood to prevent episodes of acute manic and depression. Multiple lines of evidence point to lithium as an anti-suicidal, anti-viral, anti-cancer, immunomodulatory, neuroprotective and osteoprotective agent. This review article provides a comprehensive review of studies investigating the bone-enhancing effects of lithium and its possible underlying molecular mechanisms. Most of the animal experimental studies reported the beneficial effects of lithium in defective bones but not in healthy bones. In humans, the effects of lithium on bones remain heterogeneous. Mechanistically, lithium promotes osteoblastic activities by activating canonical Wingless (Wnt)/beta (β)-catenin, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and bone morphogenetic protein-2 (BMP-2) transduction pathways but suppresses osteoclastic activities by inhibiting the receptor activator of nuclear factor-kappa B (RANK)/receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and calcium signaling cascades. In conclusion, lithium confers protection to the skeleton but its clinical utility awaits further validation from human clinical trials.

Matched MeSH terms: Proto-Oncogene Proteins c-akt
Hericium erinaceus (Bull.: Fr.) Pers., a medicinal mushroom, activates peripheral nerve regeneration

Wong KH, Kanagasabapathy G, Naidu M, David P, Sabaratnam V

Chin J Integr Med, 2016 Oct;22(10):759-67.
PMID: 25159861 DOI: 10.1007/s11655-014-1624-2

OBJECTIVE: To study the ability of aqueous extract of Hericium erinaceus mushroom in the treatment of nerve injury following peroneal nerve crush in Sprague-Dawley rats.
METHODS: Aqueous extract of Hericium erinaceus was given by daily oral administration following peroneal nerve crush injury in Sprague-Dawley rats. The expression of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways; and c-Jun and c-Fos genes were studied in dorsal root ganglia (DRG) whereas the activity of protein synthesis was assessed in peroneal nerves by immunohistochemical method.
RESULTS: Peripheral nerve injury leads to changes at the axonal site of injury and remotely located DRG containing cell bodies of sensory afferent neurons. Immunofluorescence studies showed that DRG neurons ipsilateral to the crush injury in rats of treated groups expressed higher immunoreactivities for Akt, MAPK, c-Jun and c-Fos as compared with negative control group (P <0.05). The intensity of nuclear ribonucleoprotein in the distal segments of crushed nerves of treated groups was significantly higher than in the negative control group (P <0.05).
CONCLUSION: H. erinaceus is capable of promoting peripheral nerve regeneration after injury. Potential signaling pathways include Akt, MAPK, c-Jun, and c-Fos, and protein synthesis have been shown to be involved in its action.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism
Bisleuconothine A Induces Autophagosome Formation by Interfering with AKT-mTOR Signaling Pathway

Wong CP, Seki A, Horiguchi K, Shoji T, Arai T, Nugroho AE, et al.

J Nat Prod, 2015 Jul 24;78(7):1656-62.
PMID: 26176165 DOI: 10.1021/acs.jnatprod.5b00258

We have previously reported that bisleuconothine A (Bis-A), a novel bisindole alkaloid isolated from Leuconotis griffithii, showed cytostatic activity in several cell lines. In this report, the mechanism of Bis-A-induced cytostatic activity was investigated in detail using A549 cells. Bis-A did not cause apoptosis, as indicated by analysis of annexin V and propidium iodide staining. Expression of all tested apoptosis-related proteins was also unaffected by Bis-A treatment. Bis-A was found to increase LC3 lipidation in MCF7 cells as well as A549 cells, suggesting that Bis-A cytostatic activity may be due to induction of autophagy. Subsequent investigation via Western blotting and immunofluorescence staining indicated that Bis-A induced formation but prevented degradation of autophagosomes. Mechanistic studies showed that Bis-A down-regulated phosphorylation of protein kinase B (AKT) and its downstream kinase, PRAS40, which is an mTOR repressor. Moreover, phosphorylation of p70S6K, an mTOR-dependent kinase, was also down-regulated. Down-regulation of these kinases suggests that the increase in LC3 lipidation may be due to mTOR deactivation. Thus, the cytostatic activity shown by Bis-A may be attributed to its induction of autophagosome formation. The Bis-A-induced autophagosome formation was suggested to be caused by its interference with the AKT-mTOR signaling pathway.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism
Mechanism of Chemoprevention against Colon Cancer Cells Using Combined Gelam Honey and Ginger Extract via mTOR and Wnt/β-catenin Pathways

Wee LH, Morad NA, Aan GJ, Makpol S, Wan Ngah WZ, Mohd Yusof YA

Asian Pac J Cancer Prev, 2015;16(15):6549-56.
PMID: 26434873

The PI3K-Akt-mTOR, Wnt/β-catenin and apoptosis signaling pathways have been shown to be involved in genesis of colorectal cancer (CRC). The aim of this study was to elucidate whether combination of Gelam honey and ginger might have chemopreventive properties in HT29 colon cancer cells by modulating the mTOR, Wnt/β-catenin and apoptosis signaling pathways. Treatment with Gelam honey and ginger reduced the viability of the HT29 cells dose dependently with IC50 values of 88 mg/ml and 2.15 mg/ml respectively, their while the combined treatment of 2 mg/ml of ginger with 31 mg/ml of Gelam honey inhibited growth of most HT29 cells. Gelam honey, ginger and combination induced apoptosis in a dose dependent manner with the combined treatment exhibiting the highest apoptosis rate. The combined treatment downregulated the gene expressions of Akt, mTOR, Raptor, Rictor, β-catenin, Gsk3β, Tcf4 and cyclin D1 while cytochrome C and caspase 3 genes were shown to be upregulated. In conclusion, the combination of Gelam honey and ginger may serve as a potential therapy in the treatment of colorectal cancer through inhibiton of mTOR, Wnt/β catenin signaling pathways and induction of apoptosis pathway.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/genetics
Fulltext Regulation of S1PR2 by the EBV oncogene LMP1 in aggressive ABC-subtype diffuse large B-cell lymphoma

Vockerodt M, Vrzalikova K, Ibrahim M, Nagy E, Margielewska S, Hollows R, et al.

J Pathol, 2019 06;248(2):142-154.
PMID: 30666658 DOI: 10.1002/path.5237

The Epstein-Barr virus (EBV) is found almost exclusively in the activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), yet its contribution to this tumour remains poorly understood. We have focused on the EBV-encoded latent membrane protein-1 (LMP1), a constitutively activated CD40 homologue expressed in almost all EBV-positive DLBCLs and which can disrupt germinal centre (GC) formation and drive lymphomagenesis in mice. Comparison of the transcriptional changes that follow LMP1 expression with those that follow transient CD40 signalling in human GC B cells enabled us to define pathogenic targets of LMP1 aberrantly expressed in ABC-DLBCL. These included the down-regulation of S1PR2, a sphingosine-1-phosphate (S1P) receptor that is transcriptionally down-regulated in ABC-DLBCL, and when genetically ablated leads to DLBCL in mice. Consistent with this, we found that LMP1-expressing primary ABC-DLBCLs were significantly more likely to lack S1PR2 expression than were LMP1-negative tumours. Furthermore, we showed that the down-regulation of S1PR2 by LMP1 drives a signalling loop leading to constitutive activation of the phosphatidylinositol-3-kinase (PI3-K) pathway. Finally, core LMP1-PI3-K targets were enriched for lymphoma-related transcription factors and genes associated with shorter overall survival in patients with ABC-DLBCL. Our data identify a novel function for LMP1 in aggressive DLBCL. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Matched MeSH terms: Proto-Oncogene Proteins c-akt/metabolism
Fulltext Molecular Action of Hydroxytyrosol in Attenuation of Intimal Hyperplasia: A Scoping Review

Vijakumaran U, Yazid MD, Hj Idrus RB, Abdul Rahman MR, Sulaiman N

Front Pharmacol, 2021;12:663266.
PMID: 34093194 DOI: 10.3389/fphar.2021.663266

Objective: Hydroxytyrosol (HT), a polyphenol of olive plant is well known for its antioxidant, anti-inflammatory and anti-atherogenic properties. The aim of this systematic search is to highlight the scientific evidence evaluating molecular efficiency of HT in halting the progression of intimal hyperplasia (IH), which is a clinical condition arises from endothelial inflammation. Methods: A systematic search was performed through PubMed, Web of Science and Scopus, based on pre-set keywords which are Hydroxytyrosol OR 3,4-dihydroxyphenylethanol, AND Intimal hyperplasia OR Neointimal hyperplasia OR Endothelial OR Smooth muscles. Eighteen in vitro and three in vitro and in vivo studies were selected based on a pre-set inclusion and exclusion criteria. Results: Based on evidence gathered, HT was found to upregulate PI3K/AKT/mTOR pathways and supresses inflammatory factors and mediators such as IL-1β, IL-6, E-selectin, P-selectin, VCAM-1, and ICAM-1 in endothelial vascularization and functioning. Two studies revealed HT disrupted vascular smooth muscle cells (SMC) cell cycle by dephosphorylating ERK1/2 and AKT pathways. Therefore, HT was proven to promote endothelization and inhibit vascular SMCs migration thus hampering IH development. However, none of these studies described the effect of HT collectively in both vascular endothelial cells (EC) and SMCs in IH ex vivo model. Conclusions: Evidence from this concise review provides an insight on HT regulation of molecular pathways in reendothelization and inhibition of VSMCs migration. Henceforth, we propose effect of HT on IH prevention could be further elucidated through in vivo and ex vivo model.

Matched MeSH terms: Proto-Oncogene Proteins c-akt

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