scholarly journals Stopping Transformed Growth with Cytoskeletal Proteins: Turning a Devil into an Angel

2017 ◽  
Author(s):  
Bo Yang ◽  
Haguy Wolfenson ◽  
Naotaka Nakazawa ◽  
Shuaimin Liu ◽  
Junqiang Hu ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cytoskeletal Proteins ◽  
Transformed Cells ◽  
Cytoskeletal Protein ◽  
Protein Levels ◽  
Rigidity Sensing ◽  
Contractile System ◽  
Myosin Iia ◽  
Dependent Growth ◽  
Block Growth

SummaryThe major hallmark of cancer cells is uncontrollable growth on soft matrices (transformed growth), which indicates that they have lost the ability to properly sense the rigidity of their surroundings. Recent studies of fibroblasts show that local contractions by cytoskeletal rigidity sensor units block growth on soft surfaces and their depletion causes transformed growth. The contractile system involves many cytoskeletal proteins that must be correctly assembled for proper rigidity sensing. We tested the hypothesis that cancer cells lack rigidity sensing due to their inability to assemble contractile units because of altered cytoskeletal protein levels. In four widely different cancers, there were over ten-fold fewer rigidity-sensing contractions compared with normal fibroblasts. Restoring normal levels of cytoskeletal proteins restored rigidity sensing and rigidity-dependent growth in transformed cells. Most commonly, this involved restoring balanced levels of the tropomyosins 2.1 (often depleted by miR-21) and 3 (often overexpressed). Restored cells could be transformed again by depleting other cytoskeletal proteins including myosin IIA. Thus, the depletion of rigidity sensing modules enables growth on soft surfaces and many different perturbations of cytoskeletal proteins can disrupt rigidity sensing thereby causing transformed growth of cancer cells.

scholarly journals A Tale of Two States: Normal and Transformed, With and Without Rigidity Sensing

2019 ◽  
Vol 35 (1) ◽  
pp. 169-190 ◽  
Author(s):  
Michael Sheetz
Keyword(s):  
Wound Healing ◽  
Strong Correlation ◽  
Mechanical Characteristics ◽  
Cytoskeletal Proteins ◽  
Transformed Cells ◽  
Normal Cells ◽  
Rigidity Sensing ◽  
Tissue Healing ◽  
Probability Of Cancer ◽  
Different Tissues

For many years, major differences in morphology, motility, and mechanical characteristics have been observed between transformed cancer and normal cells. In this review, we consider these differences as linked to different states of normal and transformed cells that involve distinct mechanosensing and motility pathways. There is a strong correlation between repeated tissue healing and/or inflammation and the probability of cancer, both of which involve growth in adult tissues. Many factors are likely needed to enable growth, including the loss of rigidity sensing, but recent evidence indicates that microRNAs have important roles in causing the depletion of growth-suppressing proteins. One microRNA, miR-21, is overexpressed in many different tissues during both healing and cancer. Normal cells can become transformed by the depletion of cytoskeletal proteins that results in the loss of mechanosensing, particularly rigidity sensing. Conversely, the transformed state can be reversed by the expression of cytoskeletal proteins—without direct alteration of hormone receptor levels. In this review, we consider the different stereotypical forms of motility and mechanosensory systems. A major difference between normal and transformed cells involves a sensitivity of transformed cells to mechanical perturbations. Thus, understanding the different mechanical characteristics of transformed cells may enable new approaches to treating wound healing and cancer.

scholarly journals SET Levels Contribute to Cohesion Fatigue

2021 ◽  
pp. mbc.E20-12-0778
Author(s):  
Lu Yang ◽  
Qian Zhang ◽  
Tianhua Niu ◽  
Hong Liu
Keyword(s):  
Tumor Progression ◽  
Cancer Cells ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Chromosome Instability ◽  
Underlying Mechanism ◽  
Transformed Cells ◽  
Common Phenomenon ◽  
Pp2a Activity ◽  
Protein Levels

Chromosome instability (CIN) is a major hallmark of cancer cells and believed to drive tumor progression. Several cellular defects including weak centromeric cohesion are proposed to promote CIN, but the molecular mechanisms underlying these defects are poorly understood. In a screening for SET protein levels in various cancer cell lines, we found that most of the cancer cells exhibit higher SET protein levels than non-transformed cells, including RPE-1. Cancer cells with elevated SET often show weak centromeric cohesion, revealed by MG132-induced cohesion fatigue. Partial SET knockdown largely strengthens centromeric cohesion in cancer cells without increasing overall PP2A activity. Pharmacologically increased PP2A activity in these cancer cells barely ameliorates centromeric cohesion. These results suggest that compromised PP2A activity, a common phenomenon in cancer cells, may not be responsible for weak centromeric cohesion. Furthermore, centromeric cohesion in cancer cells can be strengthened by ectopic Sgo1 overexpression and weakened by SET WT, not by Sgo1-binding-deficient mutants. Altogether, these findings demonstrate that SET overexpression contributes to impaired centromeric cohesion in cancer cells and illustrate mis-regulated SET-Sgo1 pathway as an underlying mechanism.

scholarly journals Colorectal Cancer Apoptosis Induced by Dietary δ-Valerobetaine Involves PINK1/Parkin Dependent-Mitophagy and SIRT3

2021 ◽  
Vol 22 (15) ◽  
pp. 8117
Author(s):  
Nunzia D’Onofrio ◽  
Elisa Martino ◽  
Luigi Mele ◽  
Antonino Colloca ◽  
Martina Maione ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Mitochondrial Dysfunction ◽  
Cancer Cells ◽  
Current Knowledge ◽  
Apoptotic Cell ◽  
Critical Role ◽  
Dependent Manner ◽  
Colon Cancer Cells ◽  
Protein Levels

Understanding the mechanisms of colorectal cancer progression is crucial in the setting of strategies for its prevention. δ-Valerobetaine (δVB) is an emerging dietary metabolite showing cytotoxic activity in colon cancer cells via autophagy and apoptosis. Here, we aimed to deepen current knowledge on the mechanism of δVB-induced colon cancer cell death by investigating the apoptotic cascade in colorectal adenocarcinoma SW480 and SW620 cells and evaluating the molecular players of mitochondrial dysfunction. Results indicated that δVB reduced cell viability in a time-dependent manner, reaching IC50 after 72 h of incubation with δVB 1.5 mM, and caused a G2/M cell cycle arrest with upregulation of cyclin A and cyclin B protein levels. The increased apoptotic cell rate occurred via caspase-3 activation with a concomitant loss in mitochondrial membrane potential and SIRT3 downregulation. Functional studies indicated that δVB activated mitochondrial apoptosis through PINK1/Parkin pathways, as upregulation of PINK1, Parkin, and LC3B protein levels was observed (p < 0.0001). Together, these findings support a critical role of PINK1/Parkin-mediated mitophagy in mitochondrial dysfunction and apoptosis induced by δVB in SW480 and SW620 colon cancer cells.

scholarly journals BIOM-55. DGKζ-TARGETED REGULATION OF MIR-34A IN THE PROLIFERATION AND TUMORIGENICITY OF HUMAN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii13-ii13
Author(s):  
Wangxian Gu ◽  
Guoqing Wan ◽  
Yanjun Zheng ◽  
Xintong Yang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Precancerous Lesions ◽  
Lipid Kinase ◽  
Human Glioblastoma ◽  
Kinase Substrate ◽  
Downstream Target ◽  
Protein Levels ◽  
Type Iv

Abstract Diacylglycerol kinase (DGK) is a lipid kinase that catalyzes the phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA), which uses ATP as a phosphate donor. Diacylglycerol kinases ζ(DGKζ) is characterized as specific type IV due to its myristoylated alanine-rich C-kinase substrate (MARCKS), ankyrin, and PDZ binding domain. Similar to other DGKs, DGKζ is also reported to be abnormally expressed in human colorectal cancer cells, and it is indispensable for the proliferation of cancer cells. However, its implications in human glioblastoma (GBM) is largely unknown. Both the mRNA and protein levels of DGKζ were significantly higher in GBM tissues than in precancerous lesions. Knockdown of DGKζ inhibited GBM cell proliferation, cell cycle and promoted apoptosis of GBM cells. Moreover, down-regulation of DGKζ markedly reduced in vitro colony formation and in vivo tumorigenic capability. Furthermore, we confirmed that DGKζ was the downstream target of miR-34a. The expression level of DGKζ was negatively correlated with miR-34a in GBM tissues. Overexpression of DGKζ reversed the tumor suppressive roles of miR-34a in GBM cells. Taken together, DGKζ can act as a potential prognostic biomarker for GBM patients and promote the growth of GBM cells was regulated by miR-34a, and it may represent a promising therapeutic target for patients with GBM.

Melatonin and vitamin D3 synergistically down-regulate Akt and MDM2 leading to TGFβ-1-dependent growth inhibition of breast cancer cells

2010 ◽  
pp. no-no ◽  
Author(s):  
Sara Proietti ◽  
Alessandra Cucina ◽  
Fabrizio D’Anselmi ◽  
Simona Dinicola ◽  
Alessia Pasqualato ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Inhibition ◽  
Cancer Cells ◽  
Vitamin D3 ◽  
Breast Cancer Cells ◽  
Dependent Growth

Newly synthesized benzimidazoles inhibits vascular endothelial growth factor and matrix metalloproteinase-2 and -9 levels in prostate cancer cells

2021 ◽  
Vol 21 ◽  
Author(s):  
Suleyman Ilhan ◽  
Gamze Dilekci ◽  
Adem Guner ◽  
Hakan Bektas
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Umbilical Vein ◽  
Imidazole Ring ◽  
Matrix Metalloproteinase 2 ◽  
Benzimidazole Derivatives ◽  
Prostate Cancer Cells ◽  
Protein Levels ◽  
Umbilical Vein Endothelial Cells

Background: Investigating the effects of newly synthesized agents on various molecular mechanisms to understand their mechanism of action is an important step of pre-clinical screening. Benzimidazoles are composed of a unique fused benzene and imidazole ring and have attracted great attention due to their broad bioactivities, including antitumor. Objective: In the current study, we reported the synthesis of novel benzimidazole derivatives and investigated the possible cytotoxic and anti-angiogenic effects on human prostate cancer and umbilical vein endothelial cells (HUVECs). Methods: MTT assay was used to assess cell viability. A scratch assay was conducted to monitor the migration of cells. mRNA expression levels of VEGF, MMP-2, and MMP-9 were evaluated using qPCR. Changes in protein levels were evaluated by western blotting. Results: Compound G1, having a chlorine moiety, showed a potent cytotoxic activity on both prostate cancer cells and HUVECs, and inhibited cell migration via decreasing the mRNA and protein levels of key angiogenesis-related molecules such as VEGF, MMP-2, and MMP-9. Conclusion: These results suggest that newly synthesized G1 may be a novel anti-angiogenic agent for prostate cancer treatment.

Dihydrotestosterone induces chemo-resistance of triple-negative breast MDA-MB-231 cancer cells towards doxorubicin independent of ABCG2 and miR-328-3p

2021 ◽  
Vol 14 ◽  
Author(s):  
Bayan Al-Momany ◽  
Hana Hammad ◽  
Mamoun Ahram
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Drug Response ◽  
Therapeutic Strategy ◽  
Triple Negative ◽  
Model System ◽  
Cell Resistance ◽  
Protein Levels ◽  
Abcg2 Protein ◽  
Mcf 7

Background: Androgens potentially have an important role in the biology of breast cancer, particularly triple-negative breast cancer (TNBC). Androgen receptor (AR) may offer a novel therapeutic strategy including the use of microRNA (miRNA) molecules. We have previously shown that AR agonist, dihydrotestosterone (DHT), increases the expression of miR-328-3p in the TNBC MDA-MB-231 cells. One target of the latter miRNA is ATP-binding cassette subfamily G member 2 (ABCG2), which modulates the chemo-response of cancer cells by pumping out xenobiotics. Objective: Using MDA-MB-231 cells as a model system for TNBC, we hypothesized that DHT would induce cell sensitivity towards doxorubicin via increasing levels of miR-328-3p and, consequently, reducing ABCG2 levels. Methods: Chemo-response of cells towards doxorubicin, tamoxifen, and mitoxantrone was evaluated using cell viability MTT assay. Cells were transfected with both miR-328-3p mimic or antisense molecules. Real-time PCR was utilized to assess RNA levels and immunoblotting was performed to investigate levels of ABCG2 protein. PCR arrays were used to assess changes in the expression of drug response regulatory genes. Results: Contrary to our hypothesis, treating MDA-MB-231 cells with DHT, no effect towards tamoxifen or mitoxantrone and increased cell resistance towards doxorubicin were noted, concomitant with decreased expression of ABCG2. This under-expression of ABCG2 was also found in MCF-7 and MDA-MB-453 cells treated with DHT. Although miR-328-3p decreased ABCG2 mRNA and protein levels, the miRNA did not alter the chemo-response of cells towards doxorubicin and did not affect DHT-induced chemo-resistance. AR activation slightly decreased the expression of 5 genes, including insulin-like growth factor 1 receptor, that may explain the mechanism of DHT-induced chemo-resistance of cells. Conclusion: DHT regulates chemo-response via a mechanism independent of ABCG2 and miR-328-3p.

scholarly journals A Critical Role of Glutamine and Asparagine γ-Nitrogen in Nucleotide Biosynthesis in Cancer Cells Hijacked by an Oncogenic Virus

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Ying Zhu ◽  
Tingting Li ◽  
Suzane Ramos da Silva ◽  
Jae-Jin Lee ◽  
Chun Lu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cancer Cells ◽  
Metabolic Pathway ◽  
Tca Cycle ◽  
Glutamine Metabolism ◽  
Transformed Cells ◽  
Oncogenic Virus ◽  
Phosphoribosyl Pyrophosphate ◽  
Rate Limiting

ABSTRACT While glutamine is a nonessential amino acid that can be synthesized from glucose, some cancer cells primarily depend on glutamine for their growth, proliferation, and survival. Numerous types of cancer also depend on asparagine for cell proliferation. The underlying mechanisms of the glutamine and asparagine requirement in cancer cells in different contexts remain unclear. In this study, we show that the oncogenic virus Kaposi’s sarcoma-associated herpesvirus (KSHV) accelerates the glutamine metabolism of glucose-independent proliferation of cancer cells by upregulating the expression of numerous critical enzymes, including glutaminase 2 (GLS2), glutamate dehydrogenase 1 (GLUD1), and glutamic-oxaloacetic transaminase 2 (GOT2), to support cell proliferation. Surprisingly, cell crisis is rescued only completely by supplementation with asparagine but minimally by supplementation with α-ketoglutarate, aspartate, or glutamate upon glutamine deprivation, implying an essential role of γ-nitrogen in glutamine and asparagine for cell proliferation. Specifically, glutamine and asparagine provide the critical γ-nitrogen for purine and pyrimidine biosynthesis, as knockdown of four rate-limiting enzymes in the pathways, including carbamoylphosphate synthetase 2 (CAD), phosphoribosyl pyrophosphate amidotransferase (PPAT), and phosphoribosyl pyrophosphate synthetases 1 and 2 (PRPS1 and PRPS2, respectively), suppresses cell proliferation. These findings indicate that glutamine and asparagine are shunted to the biosynthesis of nucleotides and nonessential amino acids from the tricarboxylic acid (TCA) cycle to support the anabolic proliferation of KSHV-transformed cells. Our results illustrate a novel mechanism by which an oncogenic virus hijacks a metabolic pathway for cell proliferation and imply potential therapeutic applications in specific types of cancer that depend on this pathway. IMPORTANCE We have previously found that Kaposi’s sarcoma-associated herpesvirus (KSHV) can efficiently infect and transform primary mesenchymal stem cells; however, the metabolic pathways supporting the anabolic proliferation of KSHV-transformed cells remain unknown. Glutamine and asparagine are essential for supporting the growth, proliferation, and survival of some cancer cells. In this study, we have found that KSHV accelerates glutamine metabolism by upregulating numerous critical metabolic enzymes. Unlike most cancer cells that primarily utilize glutamine and asparagine to replenish the TCA cycle, KSHV-transformed cells depend on glutamine and asparagine for providing γ-nitrogen for purine and pyrimidine biosynthesis. We identified four rate-limiting enzymes in this pathway that are essential for the proliferation of KSHV-transformed cells. Our results demonstrate a novel mechanism by which an oncogenic virus hijacks a metabolic pathway for cell proliferation and imply potential therapeutic applications in specific types of cancer that depend on this pathway.

VITAMIN D DERIVATIVES IN COMBINATION WITH 9-cis RETINOIC ACID PROMOTE ACTIVE CELL DEATH IN BREAST CANCER CELLS

1995 ◽  
Vol 14 (3) ◽  
pp. 391-394 ◽  
Author(s):  
S Y James ◽  
A G Mackay ◽  
K W Colston
Keyword(s):  
Breast Cancer ◽  
Vitamin D ◽  
Retinoic Acid ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
P53 Protein ◽  
Protein A ◽  
Therapeutic Implications ◽  
Protein Levels ◽  
Mcf 7

ABSTRACT The effects of the novel vitamin D analogue, EB1089 alone, or in combination with the retinoid, 9-cis retinoic acid (9-cis RA) on indices of apoptosis in MCF-7 breast cancer cells have been examined. EB1089 was capable of reducing bcl-2 protein, a suppressor of apoptosis, and increasing p53 protein levels in MCF-7 cell cultures following 96h treatment. In the presence of 9-cis RA, EB1089 acted to further enhance the down-regulation and up-regulation of bcl-2 and p53 respectively. Furthermore, EB1089 induces DNA fragmentation in MCF-7 cells, a key feature of apoptosis, alone and in combination with 9-cis RA in situ. The observation that EB1089 and 9-cis RA act in a cooperative manner to enhance induction of apoptosis in these cells may have therapeutic implications.

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