scholarly journals Molecular Mechanisms Underlying Autophagy-Mediated Treatment Resistance in Cancer

Cancers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1775 ◽  
Author(s):  
Cally J. Ho ◽  
Sharon M. Gorski
Keyword(s):  
Tumor Progression ◽  
Signaling Pathways ◽  
Cancer Patients ◽  
Targeted Therapies ◽  
Molecular Mechanisms ◽  
Treatment Resistance ◽  
Akt Signaling ◽  
Diagnostic Tools ◽  
Cancer Types

Despite advances in diagnostic tools and therapeutic options, treatment resistance remains a challenge for many cancer patients. Recent studies have found evidence that autophagy, a cellular pathway that delivers cytoplasmic components to lysosomes for degradation and recycling, contributes to treatment resistance in different cancer types. A role for autophagy in resistance to chemotherapies and targeted therapies has been described based largely on associations with various signaling pathways, including MAPK and PI3K/AKT signaling. However, our current understanding of the molecular mechanisms underlying the role of autophagy in facilitating treatment resistance remains limited. Here we provide a comprehensive summary of the evidence linking autophagy to major signaling pathways in the context of treatment resistance and tumor progression, and then highlight recently emerged molecular mechanisms underlying autophagy and the p62/KEAP1/NRF2 and FOXO3A/PUMA axes in chemoresistance.

scholarly journals Role of E2Fs and mitotic regulators controlled by E2Fs in the epithelial to mesenchymal transition

2019 ◽  
Vol 244 (16) ◽  
pp. 1419-1429
Author(s):  
Shirley Jusino ◽  
Harold I Saavedra
Keyword(s):  
Epithelial Cells ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Drug Targets ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Centrosome Amplification ◽  
Mesenchymal Transition

The epithelial-to-mesenchymal transition (EMT) is a complex cellular process in which epithelial cells acquire mesenchymal properties. EMT occurs in three biological settings: development, wound healing and fibrosis, and tumor progression. Despite occurring in three independent biological settings, EMT signaling shares some molecular mechanisms that allow epithelial cells to de-differentiate and acquire mesenchymal characteristics that confer cells invasive and migratory capacity to distant sites. Here we summarize the molecular mechanism that delineates EMT and we will focus on the role of E2 promoter binding factors (E2Fs) in EMT during tumor progression. Since the E2Fs are presently undruggable due to their control in numerous pivotal cellular functions and due to the lack of selectivity against individual E2Fs, we will also discuss the role of three mitotic regulators and/or mitotic kinases controlled by the E2Fs (NEK2, Mps1/TTK, and SGO1) in EMT that can be useful as drug targets. Impact statement The study of the epithelial to mesenchymal transition (EMT) is an active area of research since it is one of the early intermediates to invasion and metastasis—a state of the cancer cells that ultimately kills many cancer patients. We will present in this review that besides their canonical roles as regulators of proliferation, unregulated expression of the E2F transcription factors may contribute to cancer initiation and progression to metastasis by signaling centrosome amplification, chromosome instability, and EMT. Since our discovery that the E2F activators control centrosome amplification and mitosis in cancer cells, we have identified centrosome and mitotic regulators that may represent actionable targets against EMT and metastasis in cancer cells. This is impactful to all of the cancer patients in which the Cdk/Rb/E2F pathway is deregulated, which has been estimated to be most cancer patients with solid tumors.

Biological role of AKT, and regulation of AKT signaling pathway by thymoquinone: perspectives in cancer therapeutics

2020 ◽  
Vol 20 ◽  
Author(s):  
Md. Junaid ◽  
Yeasmin Akter ◽  
Syeda Samira Afrose ◽  
Mousumi Tania ◽  
Md. Asaduzzaman Khan
Keyword(s):  
Clinical Trials ◽  
Signaling Pathways ◽  
Signaling Pathway ◽  
Inhibitory Effect ◽  
Akt Signaling ◽  
Review Article ◽  
Therapeutic Drug ◽  
Akt Signaling Pathway ◽  
Anti Cancer

Background: AKT/PKB is an important enzyme with numerous biological functions, and its overexpression is related to the carcinogenesis. AKT stimulates different signaling pathways that are downstream of activated tyrosine kinases and phosphatidylinositol 3-kinase, hence functions as an important target for anti-cancer drugs. Objective: In this review article, we have interpreted the role of AKT signaling pathways in cancer and natural inhibitory effect of Thymoquinone (TQ) in AKT and its possible mechanism. Method: We have collected the updated information and data on AKT, their role in cancer and inhibitory effect of TQ in AKT signaling pathway from google scholar, PubMed, Web of Science, Elsevier, Scopus and many more. Results: There are many drugs already developed, which can target AKT, but very few among them have passed clinical trials. TQ is a natural compound, mainly found in black cumin, which has been found to have potential anti-cancer activities. TQ targets numerous signaling pathways, including AKT, in different cancers. In fact, many studies revealed that AKT is one of the major targets of TQ. The preclinical success of TQ suggests its clinical studies on cancer. Conclusion: This review article summarizes the role of AKT in carcinogenesis, its potent inhibitors in clinical trials, and how TQ acts as an inhibitor of AKT and TQ’s future as a cancer therapeutic drug.

The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Polymorphonuclear Neutrophils ◽  
Microbial Pathogens ◽  
Human Neutrophils ◽  
No Production ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

Classic and Novel Signaling Pathways Involved in Cancer: Targeting the NF-κB and Syk Signaling Pathways

2019 ◽  
Vol 14 (3) ◽  
pp. 219-225 ◽  
Author(s):  
Cong Tang ◽  
Guodong Zhu
Keyword(s):  
Cancer Therapy ◽  
Tyrosine Kinase ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Cell Receptor ◽  
Transmembrane Receptors ◽  
Biological Responses ◽  
Different Types

The nuclear factor kappa B (NF-κB) consists of a family of transcription factors involved in the regulation of a wide variety of biological responses. Growing evidence support that NF-κB plays a major role in oncogenesis as well as its well-known function in the regulation of immune responses and inflammation. Therefore, we made a review of the diverse molecular mechanisms by which the NF-κB pathway is constitutively activated in different types of human cancers and the potential role of various oncogenic genes regulated by this transcription factor in cancer development and progression. We also discussed various pharmacological approaches employed to target the deregulated NF-κB signaling pathway and their possible therapeutic potential in cancer therapy. Moreover, Syk (Spleen tyrosine kinase), non-receptor tyrosine kinase which mediates signal transduction downstream of a variety of transmembrane receptors including classical immune-receptors like the B-cell receptor (BCR), which can also activate the inflammasome and NF-κB-mediated transcription of chemokines and cytokines in the presence of pathogens would be discussed as well. The highlight of this review article is to summarize the classic and novel signaling pathways involved in NF-κB and Syk signaling and then raise some possibilities for cancer therapy.

scholarly journals Akt signaling is activated by TGFβ2 and impacts tenogenic induction of mesenchymal stem cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sophia K. Theodossiou ◽  
Jett B. Murray ◽  
LeeAnn A. Hold ◽  
Jeff M. Courtright ◽  
Anne M. Carper ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Signaling Pathways ◽  
Transforming Growth Factor ◽  
Akt Signaling ◽  
Cell Alignment ◽  
Limited Information ◽  
Akt Inhibitor ◽  
Tenogenic Differentiation

Abstract Background Tissue engineered and regenerative approaches for treating tendon injuries are challenged by the limited information on the cellular signaling pathways driving tenogenic differentiation of stem cells. Members of the transforming growth factor (TGF) β family, particularly TGFβ2, play a role in tenogenesis, which may proceed via Smad-mediated signaling. However, recent evidence suggests some aspects of tenogenesis may be independent of Smad signaling, and other pathways potentially involved in tenogenesis are understudied. Here, we examined the role of Akt/mTORC1/P70S6K signaling in early TGFβ2-induced tenogenesis of mesenchymal stem cells (MSCs) and evaluated TGFβ2-induced tenogenic differentiation when Smad3 is inhibited. Methods Mouse MSCs were treated with TGFβ2 to induce tenogenesis, and Akt or Smad3 signaling was chemically inhibited using the Akt inhibitor, MK-2206, or the Smad3 inhibitor, SIS3. Effects of TGFβ2 alone and in combination with these inhibitors on the activation of Akt signaling and its downstream targets mTOR and P70S6K were quantified using western blot analysis, and cell morphology was assessed using confocal microscopy. Levels of the tendon marker protein, tenomodulin, were also assessed. Results TGFβ2 alone activated Akt signaling during early tenogenic induction. Chemically inhibiting Akt prevented increases in tenomodulin and attenuated tenogenic morphology of the MSCs in response to TGFβ2. Chemically inhibiting Smad3 did not prevent tenogenesis, but appeared to accelerate it. MSCs treated with both TGFβ2 and SIS3 produced significantly higher levels of tenomodulin at 7 days and morphology appeared tenogenic, with localized cell alignment and elongation. Finally, inhibiting Smad3 did not appear to impact Akt signaling, suggesting that Akt may allow TGFβ2-induced tenogenesis to proceed during disruption of Smad3 signaling. Conclusions These findings show that Akt signaling plays a role in TGFβ2-induced tenogenesis and that tenogenesis of MSCs can be initiated by TGFβ2 during disruption of Smad3 signaling. These findings provide new insights into the signaling pathways that regulate tenogenic induction in stem cells.

scholarly journals The Molecular Mechanism of Epithelial–Mesenchymal Transition for Breast Carcinogenesis

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 476 ◽  
Author(s):  
Chia-Jung Li ◽  
Pei-Yi Chu ◽  
Giou-Teng Yiang ◽  
Meng-Yu Wu
Keyword(s):  
Epithelial Cells ◽  
Tumor Progression ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Transforming Growth Factor Β ◽  
Inhibition Of Proliferation ◽  
Mesenchymal Transition

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.

scholarly journals Role of the NUDT Enzymes in Breast Cancer

2021 ◽  
Vol 22 (5) ◽  
pp. 2267
Author(s):  
Roni H. G. Wright ◽  
Miguel Beato
Keyword(s):  
Breast Cancer ◽  
Signaling Pathways ◽  
Cancer Progression ◽  
Breast Cancers ◽  
Metastatic Colonization ◽  
Hormone Receptor Positive ◽  
Aggressive Cancer ◽  
Cancer Types ◽  
Metastatic Process

Despite global research efforts, breast cancer remains the leading cause of cancer death in women worldwide. The majority of these deaths are due to metastasis occurring years after the initial treatment of the primary tumor and occurs at a higher frequency in hormone receptor-positive (Estrogen and Progesterone; HR+) breast cancers. We have previously described the role of NUDT5 (Nudix-linked to moiety X-5) in HR+ breast cancer progression, specifically with regards to the growth of breast cancer stem cells (BCSCs). BCSCs are known to be the initiators of epithelial-to-mesenchyme transition (EMT), metastatic colonization, and growth. Therefore, a greater understanding of the proteins and signaling pathways involved in the metastatic process may open the door for therapeutic opportunities. In this review, we discuss the role of NUDT5 and other members of the NUDT family of enzymes in breast and other cancer types. We highlight the use of global omics data based on our recent phosphoproteomic analysis of progestin signaling pathways in breast cancer cells and how this experimental approach provides insight into novel crosstalk mechanisms for stratification and drug discovery projects aiming to treat patients with aggressive cancer.

scholarly journals Paradoxical role of high mobility group box 1 in glioma: a suppressor or a promoter?

2017 ◽  
Author(s):  
Richard A. Seidu ◽  
Min Wu ◽  
Zhaoliang Su ◽  
Huaxi Xu
Keyword(s):  
Molecular Mechanisms ◽  
High Mobility ◽  
Treatment Resistance ◽  
High Mobility Group ◽  
Tissue Invasion ◽  
Self Sufficiency ◽  
Glycation End Products ◽  
And Migration ◽  
Proliferation And Migration

Gliomas represent 60% of primary intracranial brain tumors and 80% of all malignant types, with highest morbidity and mortality worldwide. Although glioma has been extensively studied, the molecular mechanisms underlying its pathology remain poorly understood. Clarification of the molecular mechanisms involved in their development and/or treatment resistance is highly required. High mobility group box 1 protein (HMGB1) is a nuclear protein that can also act as an extracellular trigger of inflammation, proliferation and migration, through receptor for advanced glycation end products and toll like receptors in a number of cancers including gliomas. It is known that excessive release of HMGB1 in cancer leads to unlimited replicative potential, ability to develop blood vessels (angiogenesis), evasion of programmed cell death (apoptosis), self-sufficiency in growth signals, insensitivity to inhibitors of growth, inflammation, tissue invasion and metastasis. In this review we explore the mechanisms by which HMGB1 regulates apoptosis and autophagy in glioma. We also looked at how HMGB1 mediates glioma regression and promotes angiogenesis as well as possible signaling pathways with an attempt to provide potential therapeutic targets for the treatment of glioma.

scholarly journals Bone remodeling stages under physiological conditions and glucocorticoid in excess: Focus on cellular and molecular mechanisms

2021 ◽  
Vol 12 (2) ◽  
pp. 212-227
Author(s):  
V. V. Povoroznyuk ◽  
N. V. Dedukh ◽  
M. A. Bystrytska ◽  
V. S. Shapovalov
Keyword(s):  
Growth Factors ◽  
Bone Resorption ◽  
Signaling Pathways ◽  
Bone Remodeling ◽  
Molecular Mechanisms ◽  
Signaling Molecules ◽  
Physiological Conditions ◽  
Bone Cell Differentiation ◽  
Repressive Effect

This review provides a rationale for the cellular and molecular mechanisms of bone remodeling stages under physiological conditions and glucocorticoids (GCs) in excess. Remodeling is a synchronous process involving bone resorption and formation, proceeding through stages of: (1) resting bone, (2) activation, (3) bone resorption, (4) reversal, (5) formation, (6) termination. Bone remodeling is strictly controlled by local and systemic regulatory signaling molecules. This review presents current data on the interaction of osteoclasts, osteoblasts and osteocytes in bone remodeling and defines the role of osteoprogenitor cells located above the resorption area in the form of canopies and populating resorption cavities. The signaling pathways of proliferation, differentiation, viability, and cell death during remodeling are presented. The study of signaling pathways is critical to understanding bone remodeling under normal and pathological conditions. The main signaling pathways that control bone resorption and formation are RANK / RANKL / OPG; M-CSF – c-FMS; canonical and non-canonical signaling pathways Wnt; Notch; MARK; TGFβ / SMAD; ephrinB1/ephrinB2 – EphB4, TNFα – TNFβ, and Bim – Bax/Bak. Cytokines, growth factors, prostaglandins, parathyroid hormone, vitamin D, calcitonin, and estrogens also act as regulators of bone remodeling. The role of non-encoding microRNAs and long RNAs in the process of bone cell differentiation has been established. MicroRNAs affect many target genes, have both a repressive effect on bone formation and activate osteoblast differentiation in different ways. Excess of glucocorticoids negatively affects all stages of bone remodeling, disrupts molecular signaling, induces apoptosis of osteocytes and osteoblasts in different ways, and increases the life cycle of osteoclasts. Glucocorticoids disrupt the reversal stage, which is critical for the subsequent stages of remodeling. Negative effects of GCs on signaling molecules of the canonical Wingless (WNT)/β-catenin pathway and other signaling pathways impair osteoblastogenesis. Under the influence of excess glucocorticoids biosynthesis of biologically active growth factors is reduced, which leads to a decrease in the expression by osteoblasts of molecules that form the osteoid. Glucocorticoids stimulate the expression of mineralization inhibitor proteins, osteoid mineralization is delayed, which is accompanied by increased local matrix demineralization. Although many signaling pathways involved in bone resorption and formation have been discovered and described, the temporal and spatial mechanisms of their sequential turn-on and turn-off in cell proliferation and differentiation require additional research.

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