scholarly journals Death and Proliferation of Lymphocytes in Immune Response and Tumor Cells Are Controlled by pH Balance

2021 ◽  
Author(s):  
Wei-ping Zeng
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Unified Theory ◽  
Biological Processes ◽  
Proliferating Cells ◽  
Proliferation Of Lymphocytes ◽  
The Warburg Effect ◽  
Acid Treatments

Many biological processes are controlled by cell death and proliferation. Previous evidence suggests that cell proliferation and death by apoptosis are regulated by separate pathways. The present study found that cellular pH was positively correlated with proliferation but negatively with cell death. Alkaline treatments enhanced lymphocyte proliferation in response to antigen challenge in vivo and in in vitro cultures, whereas acid treatments induced cell death. Low pH was incompatible with the survival of highly proliferating cells, and the susceptibility to the acid-induced death was determined in part by the proliferative status of the lymphocytes. Likewise, alkaline treatments maintained tumor cell proliferation whereas acid treatments induced death. These data support a unified theory for the regulation of cell death and proliferation where a cellular pH balance controls both events, and the mitochondria as proton generators act as pH-stats. Thus, the Warburg effect is viewed as necessary for proliferating cells to have a high cellular pH environment to both survive and accelerate proliferation.

scholarly journals AXL and CAV-1 play a role for MTH1 inhibitor TH1579 sensitivity in cutaneous malignant melanoma

2020 ◽  
Vol 27 (7) ◽  
pp. 2081-2098 ◽  
Author(s):  
Ishani Das ◽  
Helge Gad ◽  
Lars Bräutigam ◽  
Linda Pudelko ◽  
Rainer Tuominen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Dna Damage ◽  
Cell Death ◽  
Malignant Melanoma ◽  
Braf Inhibitor ◽  
Mitotic Arrest ◽  
Cutaneous Malignant Melanoma ◽  
Clinical Samples

AbstractCutaneous malignant melanoma (CMM) is the deadliest form of skin cancer and clinically challenging due to its propensity to develop therapy resistance. Reactive oxygen species (ROS) can induce DNA damage and play a significant role in CMM. MTH1 protein protects from ROS damage and is often overexpressed in different cancer types including CMM. Herein, we report that MTH1 inhibitor TH1579 induced ROS levels, increased DNA damage responses, caused mitotic arrest and suppressed CMM proliferation leading to cell death both in vitro and in an in vivo xenograft CMM zebrafish disease model. TH1579 was more potent in abrogating cell proliferation and inducing cell death in a heterogeneous co-culture setting when compared with CMM standard treatments, vemurafenib or trametinib, showing its broad anticancer activity. Silencing MTH1 alone exhibited similar cytotoxic effects with concomitant induction of mitotic arrest and ROS induction culminating in cell death in most CMM cell lines tested, further emphasizing the importance of MTH1 in CMM cells. Furthermore, overexpression of receptor tyrosine kinase AXL, previously demonstrated to contribute to BRAF inhibitor resistance, sensitized BRAF mutant and BRAF/NRAS wildtype CMM cells to TH1579. AXL overexpression culminated in increased ROS levels in CMM cells. Moreover, silencing of a protein that has shown opposing effects on cell proliferation, CAV-1, decreased sensitivity to TH1579 in a BRAF inhibitor resistant cell line. AXL-MTH1 and CAV-1-MTH1 mRNA expressions were correlated as seen in CMM clinical samples. Finally, TH1579 in combination with BRAF inhibitor exhibited a more potent cell killing effect in BRAF mutant cells both in vitro and in vivo. In summary, we show that TH1579-mediated efficacy is independent of BRAF/NRAS mutational status but dependent on the expression of AXL and CAV-1.

scholarly journals LncRNA LEF1-AS1 promotes metastasis of prostatic carcinoma via the Wnt/β-catenin pathway

2020 ◽  
Author(s):  
Weiyuan Li ◽  
Ganggang Yang ◽  
Dengke Yang ◽  
Dong Li ◽  
Qian Sun
Keyword(s):  
Cell Proliferation ◽  
Migration And Invasion ◽  
Biological Processes ◽  
Sequencing Technology ◽  
Next Generation Sequencing Technology ◽  
Normal Tissues ◽  
Factor C ◽  
Generation Sequencing

Abstract Background Long noncoding RNAs (lncRNAs), which are important functional regulators in cancer, have emerged as critical molecular regulators in various biological processes. However, the mechanisms by which LEF1-AS1 modulates Androgen-Independent Prostate Cancer (AIPC) development remain largely unknown. Methods The LEF1-AS1 expression level was detected in tumour tissues and adjacent normal tissues of AIPC patients by using next-generation sequencing technology and qRT-PCR. Cell proliferation, migration and invasion were assessed by colony formation, EDU assays and transwell assays, respectively. Xenograft assay was conducted to determine the effect of LEF1-AS1 on cell proliferation in vivo. Results LEF1-AS1 promoted the proliferation, migration, invasion and angiogenic ability of AIPC cells in vitro and in vivo. In this mechanism, LEF1-AS1 recruited the transcription factor C-myb to the promoter region of FZD2, which activated FZD2 transcription. Moreover, LEF1-AS1 functioned as a competing endogenous RNA (ceRNA) acting as a sponge for miR-328, which activated CD44. Conclusion Collectively, these data indicate that LEF1-AS1 is a tumour promoter in the development of AIPC and that it may contribute to the improvement of AIPC diagnosis and therapy.

Sphingosine Kinases (SK): Key Molecules Associated with the Activation, Proliferation and Ibrutinib-Induced Cell Death of Chronic Lympocytic Leukemia Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1714-1714
Author(s):  
Maria Belen Almejun ◽  
Mercedes Borge ◽  
Ana Colado ◽  
Enrique Podaza ◽  
Denise Risnik ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Leukemic Cells ◽  
Lymphoid Tissues ◽  
Effective Treatment Option ◽  
Ki 67 ◽  
Sphingosine Kinases ◽  
Leukemic Clone

Abstract Leukemic cells from CLL patients can survive and proliferate within lymphoid tissues where the supportive microenvironment favors their accumulation. We have previously reported that the activation of CLL cells reduces the expression of the main receptor for sphingosine 1-phosphate (S1P) (Borge M, J Immunol, 2014), a bioactive phospholipid that participates in lymphocyte egress from lymphoid tissues. S1P also mediates several biological functions, including cell growth stimulation and protection of apoptosis, through receptor independent intracellular mechanisms. S1P is generated by two isoforms of sphingosine kinases (SK1/2) and its levels are tightly controlled via degradation by intracellular S1P lyases (S1PL). Several studies have implicated the SK/S1P/S1PL pathway as an essential regulator of cell proliferation and survival in different cancer cells. The aims of our study were: a) to evaluate the expression of SK and S1PL in CLL cells, b) to assess whether key microenvironment signals are able to modulate this expression and c) to evaluate the effect of SK inhibitors on the activation and survival of the leukemic clone. We measured the basal expression of SK and S1PL by qRT-PCR on purified B cells from CLL patients (n=22) and aged-matched healthy donors (n=9), and found that CLL cells express high levels of SK1, favoring an increased SK1/S1PL ratio in the malignant clone compared to healthy B lymphocytes ( p<0.05). Similar results were obtained when SK2 was evaluated. The in vitro activation of CLL cells with anti-IgM+CD40L increased SK1/S1PL ratio (n=10, p<0.01) and the expression of the activation marker CD69. To evaluate the expression of SK1/S1PL within in vivo activated CLL cell subpopulations, we segregated the proliferative fraction (PF) of circulating CLL cells from the quiescent fraction (QF) in the same sample. As it was previously described, this PF is characterized by the presence of an active class-switch recombination process and a high expression of proliferation-related genes, such as Ki-67, c-myc, CD49d, and p27-Kip1 (Palacios F, Blood, 2010). Interestingly, SK1/S1PL ratio was increased in the PF compared with the QF (n=3). Additionally, bone marrow leukemic cells expressing high levels of CD38, which defines a subpopulation of activated lymphocytes, showed a higher S1P/S1PL ratio compared to CD38 low or negative counterparts (n=3),showing that the in vivo activated CLL cells expressed higher ratios of SK1/S1PL compared with the rest of the leukemic clone. Finally, we wondered whether the inhibition of SK impairs the survival, activation and proliferation of the leukemic clone. To this aim we employed a commercial selective SK1 and SK2 inhibitor (SKI-II, 5 and 15μM), which did not affect cell viability (n=10, evaluated at 24, 48, 72 and 96hs). However, it was able to impair the expected upregulation of CD69 induced by IgM+CD40L at 24hs (n=10, p<0.001) and the leukemic cell proliferation evaluated by CFSE dilution assay at 96hs (n=10 , p<0.001). Moreover, while SKI-II did not increase the sensitivity of CLL cells to Fludarabine or Bendamustine, it was able to enhance the cell death induced by Ibrutinib (0.3 and 3μM) (n=5, p<0.05 and p<0.01 respectively). Taking together, our results suggest that SK/S1P/S1PL axis might participate in the accumulation of the malignant clone in CLL patients and the disruption of this pathway might be a potentially effective treatment option in the future. Disclosures Bezares: Janssen: Honoraria. Gamberale:Janssen: Honoraria.

scholarly journals Raf-1 Physically Interacts with Rb and Regulates Its Function: a Link between Mitogenic Signaling and Cell Cycle Regulation

1998 ◽  
Vol 18 (12) ◽  
pp. 7487-7498 ◽  
Author(s):  
Sheng Wang ◽  
Richik N. Ghosh ◽  
Srikumar P. Chellappan
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Growth Factor ◽  
Cell Surface ◽  
Mammalian Cells ◽  
Direct Interaction ◽  
Physical Interaction ◽  
Proliferating Cells

ABSTRACT Cells initiate proliferation in response to growth factor stimulation, but the biochemical mechanisms linking signals received at the cell surface receptors to the cell cycle regulatory molecules are not yet clear. In this study, we show that the signaling molecule Raf-1 can physically interact with Rb and p130 proteins in vitro and in vivo and that this interaction can be detected in mammalian cells without overexpressing any component. The binding of Raf-1 to Rb occurs subsequent to mitogen stimulation, and this interaction can be detected only in proliferating cells. Raf-1 can inactivate Rb function and can reverse Rb-mediated repression of E2F1 transcription and cell proliferation efficiently. The region of Raf-1 involved in Rb binding spanned residues 1 to 28 at the N terminus, and functional inactivation of Rb required a direct interaction. Serum stimulation of quiescent human fibroblast HSF8 cells led to a partial translocation of Raf-1 into the nucleus, where it colocalized with Rb. Further, Raf-1 was able to phosphorylate Rb in vitro quite efficiently. We believe that the physical interaction of Raf-1 with Rb is a vital step in the growth factor-mediated induction of cell proliferation and that Raf-1 acts as a direct link between cell surface signaling cascades and the cell cycle machinery.

scholarly journals Fructose-a double edged sword for cell death versus differentiation and long-term survival of NSC-34 motor neuron like cells in vitro

2021 ◽  
Author(s):  
Divya Lodha ◽  
Jamuna R. Subramaniam
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Motor Neurons ◽  
Response Regulator ◽  
Nuclear Staining ◽  
Term Survival ◽  
High Fructose

Abstract In various neurological and neurodegenerative diseases (ND), motor neurons (MN) of the spinal cord are affected leading to movement impairments. The ND, Amyotrophic Lateral Sclerosis (ALS), is caused due to MN degeneration. ALS afflicts athletes and other major sports personalities, who generally consume fructose enriched sports drinks. Recently, we have reported that high fructose (F5%) impairs the metabolic activity in the NSC-34, MN cell line and reduces the healthspan of C. elegans. But how fructose impacts the MNs either in vitro or in vivo in the long term is not understood. Here we report, to our surprise, that high fructose (F5%) treatment of NSC-34 leads to differentiation of 1-2% of cells with progressive neurite extension. They could be maintained for 80 days in vitro with 5% CO2 and O2 at 18.8%. On the contrary, 5% fructose significantly reduced cell viability by ~85% and inhibited cell proliferation by Day10. Nuclear staining displayed multiple nuclei in the cells indicative of cytokinesis inhibition which led to the lack of cell proliferation. Further, F5% significantly increased ROS levels (^~34%), the potential cause for reduced viability. In addition, no induction of expression of the master oxidative stress response regulator, the transcription factor, nrf-2, or the downstream effector, sod1, was evident. Despite the adverse effects, in the absence of any, F5% is a potential strategy to maintain at least a small percentage of MNs for a long time, ~45 days in vitro, which also reinforces the Redox-Cell death versus cell survival conundrum.

scholarly journals LncRNA LEF1-AS1 promotes metastasis of prostatic carcinoma via the Wnt/β-catenin pathway

2020 ◽  
Author(s):  
Weiyuan Li ◽  
Ganggang Yang ◽  
Dengke Yang ◽  
Dong Li ◽  
Qian Sun
Keyword(s):  
Cell Proliferation ◽  
Migration And Invasion ◽  
Biological Processes ◽  
Sequencing Technology ◽  
Next Generation Sequencing Technology ◽  
Normal Tissues ◽  
Factor C ◽  
Generation Sequencing

Abstract Background: Long noncoding RNAs (lncRNAs), which are important functional regulators in cancer, have emerged as critical molecular regulators in various biological processes. However, the mechanisms by which LEF1-AS1 modulates Androgen-Independent Prostate Cancer (AIPC) development remain largely unknown.Methods: The LEF1-AS1 expression level was detected in tumour tissues and adjacent normal tissues of AIPC patients by using next-generation sequencing technology and qRT-PCR. Cell proliferation, migration and invasion were assessed by colony formation, EDU assays and transwell assays, respectively. Xenograft assay was conducted to determine the effect of LEF1-AS1 on cell proliferation in vivo.Results: LEF1-AS1 promoted the proliferation, migration, invasion and angiogenic ability of AIPC cells in vitro and in vivo. In this mechanism, LEF1-AS1 recruited the transcription factor C-myb to the promoter region of FZD2, which activated FZD2 transcription. Moreover, LEF1-AS1 functioned as a competing endogenous RNA (ceRNA) acting as a sponge for miR-328, which activated CD44.Conclusion: Collectively, these data indicate that LEF1-AS1 is a tumour promoter in the development of AIPC and that it may contribute to the improvement of AIPC diagnosis and therapy.

The YAP Transcriptional Co-Activator Is Not Required for Mouse Hematopoiesis, at Steady State or After 5FU Treatment.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1592-1592
Author(s):  
Wen-Chih Cheng ◽  
Osnat Bohana-Kashtan ◽  
Sebastien Morisot ◽  
Nailing Zhang ◽  
Qian Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Stem Cell ◽  
Transcription Factors ◽  
Progenitor Cell ◽  
Hippo Signaling ◽  
Es Cell ◽  
Hippo Signaling Pathway

Abstract Abstract 1592 The Yes-associated protein (YAP) is a transcriptional co-activator that interacts with many transcription factors, including RUNX2, p73, ERBB4, PEBP2α, p53BP2, SMAD7 and the TEAD/TEF proteins. Recently, it has been established that YAP is the major downstream molecule of the evolutionarily conserved Hippo signaling pathway. First elucidated in Drosophila, the Hippo signaling pathway controls organ size by regulating apoptosis and proliferation. Beginning a kinase cascade, the MST1/MST2 kinases (fly ortholog: Hippo) cooperate with the WW domain-containing SAV1 (fly ortholog: Salvador) to phosphorylate and activate the LATS1/LATS2 kinases (fly ortholog: Warts). In turn, activated LATS1/LATS2 phosphorylate and inactivate YAP (fly ortholog: Yorkie). Inactivated YAP binds to 14-3-3 and is kept in the cytosol. In contrast, unphosphorylated YAP binds to TEAD family transcription factors (fly ortholog: Scalloped) and the complex transactivates genes including cell cycle regulators (e.g. cyclin) and cell death inhibitors (e.g. IAPs, inhibitor of apoptosis). Therefore, inactivation of MST or LATS kinase, or overexpression of YAP results in organ/tissue overgrowth characterized by excessive cell proliferation and diminished apoptosis in both fly and mammals. In two transgenic mouse models, overexpression of YAP1 in liver results in reversible increase in liver size due to increased proliferation and decreased cell death of hepatocytes. Several pieces of evidence suggest that YAP regulates stem cell self-renewal and differentiation. First, transcriptional profiling of mouse stem cells (hematopoietic, neuronal and embryonic) identified both YAP1 and TEAD2 as 2 of the only 14 transcription factors commonly expressed in all 3 types of stem cell. Second, in many adult human tissues (e.g. intestine, lung, pancreas), YAP1 is preferentially expressed in stem-progenitor cell compartments. Third, in mouse intestine and chick neural tubes, overexpression of YAP results in expansion of intestinal or neural stem-progenitor cells, as well as inhibition of progenitor cell differentiation in vivo. Finally, it has been shown that YAP expression decreases during mouse ES cell differentiation. Ectopic expression of YAP can maintain ES cell pluripotency and prevent differentiation both in vitro and in vivo. Given that YAP has a proven role in regulating stem-progenitor cells in multiple tissue and multiple organisms, we set out to investigate whether YAP also regulate hematopoetic stem-progenitors in mouse and human. In conditional YAP knockout mice with a specific deletion of YAP expression in the hematopoetic system, we found no abnormalities at steady state in hemtaopoietic lineages, as assessed by CBC (complete blood counts) or immunophenotypic analysis. In addition, the YAP-null hematopietic stem-progenitors (HSPCs) had no change in vitro hematopoietic colony-forming cells. Furthermore, 5-fluorouracil treatment did not reveal a significant difference in blood cell numbers or types, between wild type and YAP-null mice. Although these results in mice suggest that YAP appears not to be required in hematopoiesis, overexpression of YAP, which promotes stem-progenitor cell proliferation in other tissues, may still provide an excellent opportunity to drive HSPC expansion. Disclosures: No relevant conflicts of interest to declare.

scholarly journals A Simple Method to AssessIn VivoProliferation in Lung Vasculature with EdU: The Case of MMC-Induced PVOD in Rat

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Antigny Fabrice ◽  
Ranchoux Benoît ◽  
Nadeau Valérie ◽  
Edmund Lau ◽  
Bonnet Sébastien ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Pulmonary Veins ◽  
Endothelial Cell Proliferation ◽  
Pulmonary Vasculature ◽  
Microvascular Endothelial Cell ◽  
Proliferating Cells ◽  
Simple Method ◽  
Gold Standard Method

5-Ethynyl-2′-deoxyuridine (EdU) incorporation is becoming the gold standard method forin vitroandin vivovisualization of proliferating cells. The small size of the fluorescent azides used for detection results in a high degree of specimen penetration. It can be used to easily detect DNA replication in large tissue samples or organ explants with low proliferation and turnover of cells formerly believed to be in a “terminal” state of differentiation. Here we describe a protocol for the localization and identification of proliferating cells in quiescent or injured pulmonary vasculature, in a model of pulmonary veno-occlusive disease (PVOD). PVOD is an uncommon form of pulmonary hypertension characterized by progressive obstruction of small pulmonary veins. We previously reported that mitomycin-C (MMC) therapy is associated with PVOD in human. We demonstrated that MMC can induce PVOD in rats, which currently represents the sole animal model that recapitulates human PVOD lesions. Using the EdU assay, we demonstrated that MMC-exposed lungs displayed areas of exuberant microvascular endothelial cell proliferation which mimics pulmonary capillary hemangiomatosis, one of the pathologic hallmarks of human PVOD.In vivopulmonary cell proliferation measurement represents an interesting methodology to investigate the potential efficacy of therapies aimed at normalizing pathologic angioproliferation.

scholarly journals Molecular imaging of nuclear factor-Y transcriptional activity maps proliferation sites in live animals

2012 ◽  
Vol 23 (8) ◽  
pp. 1467-1474 ◽  
Author(s):  
Frauke Goeman ◽  
Isabella Manni ◽  
Simona Artuso ◽  
Balaji Ramachandran ◽  
Gabriele Toietta ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Genetically Engineered ◽  
Hepatocyte Proliferation ◽  
Luciferase Expression ◽  
Nuclear Factor ◽  
Proliferating Cells ◽  
Nuclear Factor Y ◽  
Reporter Mice

In vivo imaging involving the use of genetically engineered animals is an innovative powerful tool for the noninvasive assessment of the molecular and cellular events that are often targets of therapy. On the basis of the knowledge that the activity of the nuclear factor-Y (NF-Y) transcription factor is restricted in vitro to proliferating cells, we have generated a transgenic reporter mouse, called MITO-Luc (for mitosis-luciferase), in which an NF-Y–dependent promoter controls luciferase expression. In these mice, bioluminescence imaging of NF-Y activity visualizes areas of physiological cell proliferation and regeneration during response to injury. Using this tool, we highlight for the first time a role of NF-Y activity on hepatocyte proliferation during liver regeneration. MITO-Luc reporter mice should facilitate investigations into the involvement of genes in cell proliferation and provide a useful model for studying aberrant proliferation in disease pathogenesis. They should be also useful in the development of new anti/proproliferative drugs and assessment of their efficacy and side effects on nontarget tissues.

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