Why serum starved

Cancer Lett. Zhang, Q. Cell , 37— Bowie, A. Oxidative stress and nuclear factor-kappaB activation: a reassessment of the evidence in the light of recent discoveries. Xia, Y.

NF-kappaB, an active player in human cancers. Cancer Immunol. CIR Cui, X. NF-kappaB suppresses apoptosis and promotes bladder cancer cell proliferation by upregulating survivin expression in vitro and in vivo.

Manna, S. Proteasome inhibition by bortezomib increases IL-8 expression in androgen-independent prostate cancer cells: the role of IKKalpha. Cimino, S. Oxidative stress and body composition in prostate cancer and benign prostatic hyperplasia patients. Anticancer Res. PubMed Google Scholar. Minciullo, P.

Oxidative stress in benign prostatic hyperplasia: a systematic review. Vital, P. Oxidative stress promotes benign prostatic hyperplasia.

Prostate 76 , 58— Woenckhaus, J. Proliferative inflammatory atrophy: a background lesion of prostate cancer?. Andrologia 40 , — Udensi, U. Oxidative stress in prostate hyperplasia and carcinogenesis.

CR 35 , Signal Transduct. Li, L. Intermittent hypoxia promotes melanoma lung metastasis via oxidative stress and inflammation responses in a mouse model of obstructive sleep apnea. Peiris-Pages, M. Metastasis and oxidative stress: are antioxidants a metabolic driver of progression?. Cell Metab. Shacter, E. Oxidative stress interferes with cancer chemotherapy: inhibition of lymphoma cell apoptosis and phagocytosis.

Blood 96 , — Conklin, K. Chemotherapy-associated oxidative stress: impact on chemotherapeutic effectiveness. Cancer Ther. Liao, Z. Reactive oxygen species: a volatile driver of field cancerization and metastasis. Cancer 18 , Kim, J. Hosios, A. Amino acids rather than glucose account for the majority of cell mass in proliferating mammalian cells. Cell 36 , — Helmlinger, G. Interstitial pH and pO 2 gradients in solid tumors in vivo: high-resolution measurements reveal a lack of correlation.

Longo, V. Superoxide dismutase activity is essential for stationary phase survival in Saccharomyces cerevisiae. Mitochondrial production of toxic oxygen species in vivo.

Izuishi, K. Remarkable tolerance of tumor cells to nutrient deprivation: possible new biochemical target for cancer therapy. Gray, J. MMBR 68 , — Hill, A. Cellular stress induces a protective sleep-like state in C. Lee, J. Pharmacological regulation of oxidative stress in stem cells. Shi, X. Reactive oxygen species in cancer stem cells. Wengrod, J. Radhakrishnan, S. Pro-apoptotic role of NF-kappaB: implications for cancer therapy. Acta , 53— Jennewein, C. Oncogene 31 , — Pazarentzos, E. IkappaBetaalpha inhibits apoptosis at the outer mitochondrial membrane independently of NF-kappaB retention.

EMBO J. Liu, H. TNF-alpha-induced apoptosis of macrophages following inhibition of NF-kappa B: a central role for disruption of mitochondria. AbbaspourBabaei, M. OncoTargets Ther. S Article Google Scholar.

Sonenshein, G. Cancer Biol. Barkett, M. Chappell, W. Cell Cycle 11 , — Liu, B. ROS and p a versatile partnership.

Free Radic. Zhao, Y. Cellular adaptation to nutrient deprivation: crosstalk between the mTORC1 and eIF2alpha signaling pathways and implications for autophagy. Cell Cycle 14 , — Song, Y. The role of Akt signaling in oxidative stress mediates NF-kappaB activation in mild transient focal cerebral ischemia. Blood Flow Metab.

Requirement for NF- kappa B in interleukininduced androgen receptor activation in prostate cancer cells. Prostate 64 , — Papademetrio, D. Inhibition of survival pathways MAPK and NF-kB triggers apoptosis in pancreatic ductal adenocarcinoma cells via suppression of autophagy.

Schulze-Osthoff, K. Immunobiology , 35— Ward, A. Quercetin inhibits prostate cancer by attenuating cell survival and inhibiting anti-apoptotic pathways. World J. Llovet, J. Systematic review of randomized trials for unresectable hepatocellular carcinoma: chemoembolization improves survival.

Hepatology 37 , — Culp, S. Prostatic artery chemoembolization—a viable management option for men diagnosed with prostate cancer?. JVIR 29 , Pisco, J. Safety and efficacy of prostatic artery chemoembolization for prostate cancer-initial experience. JVIR 29 , — Dillard, P. Androgen-independent prostate cancer cells acquire the complete steroidogenic potential of synthesizing testosterone from cholesterol. Song, L. The tumor suppressor NKX3. MCR 13 , — MCR Rosenthal, A. Potent and selective small molecule inhibitors of specific isoforms of Cdc2-like kinases Clk and dual specificity tyrosine-phosphorylation-regulated kinases Dyrk.

Don-Salu-Hewage, A. Cysteine C -x-C receptor 4 undergoes transportin 1-dependent nuclear localization and remains functional at the nucleus of metastatic prostate cancer cells. Scarlett, K.

MCR 16 , — Download references. We thank Edward Gellman, Ph. The content is solely the responsibility of the authors and does not necessarily represent the official views of any branch of the National Institutes of Health.

The funders had no role in conceptual design, data collection and analysis, preparation of the manuscript, or decision to publish. ElShaddai Z. White, Nakea M. Pennant, Jada R. You can also search for this author in PubMed Google Scholar. Correspondence to Cimona V. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Reprints and Permissions. White, E. Serum deprivation initiates adaptation and survival to oxidative stress in prostate cancer cells. Sci Rep 10, Download citation. Received : 09 September Accepted : 22 June Published : 27 July Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative.

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. To assess the effects of serum-starvation on nuclear material, cells were stained with Hoechst Images were captured with an Olympus IXSI inverted microscope using nm excitation and nm emission filters.

Each reaction was run in triplicate. PCR products were assessed by electrophoresis, with no primer-dimers observed for either the target genes or GAPDH, and the product specificities were also confirmed by melting curve analysis. Bax and Bcl-2 protein expression levels were examined by western blot analysis.

Proteins within the cell lysates were separated by gel electrophoresis, with protein transferred to a nitrocellulose membrane and immunoblotting performed as previously described Radioimmunoprecipitation Assay lysis buffer Qiagen, Inc.

Supernatant was transferred to a new tube and determined quantitatively by Bicinchoninic acid Protein Assay kit. Membranes were then washed four times in TBST and incubated with appropriate horseradish peroxidase-conjugated secondary antibodies ,; cat. Blots were visualized by enhanced chemiluminescence Thermo Fisher Scientific, Inc. Tca cells were subjected to scanning electron microscopy as previously described Briefly, Tca cells were exposed to serum starvation for 0, 12, 24, 36, 48 and 72 h, then fixed for scanning electron microscopy by immersion in 2.

Tca cells were exposed to serum starvation for 0, 12, 24, 36, 48 and 72 h, then fixed for TEM. All data were statistically analyzed using the SPSS The means among diverse samples were compared by one-way analysis of variance and multiple comparisons among the groups were conducted using the least-significant difference LSD method.

Dunnett's method was employed to evaluate the heterogeneity of the variance. Growth inhibitory effects on cellular proliferation, measured by MTT assay, are shown in Fig.

Suppressive effect of serum-starvation on cell proliferation, assessed by MTT assay. A peak in this effect was reached at 24 h of treatment, when the number of cells at G 1 phase had significantly increased from Cell cycle analysis of cells treated with serum-starvation for 0, 12, 24, 36, 48 and 72 h. However, apoptosis did not continue to increase with treatment time: Following 24 h of treatment, the percentage of late apoptotic cells Q2 peaked at 8.

The early apoptosis Q4 rates continued to rise, dipped at 36 h, before reaching an apex at 48 h and then gradually declining. Apoptosis rates of cells treated with serum-starvation for 0, 12, 24, 36, 48 and 72 h. Apoptosis is one of the major pathways that leads to cell death, therefore the effects of serum-starvation on apoptosis were further examined using the Hoechst staining method.

Manual observation of apoptotic cells based on cytoplasmic condensation, karyopyknosis and nuclear fragmentation revealed that the percentage of apoptotic cells increased as the duration of serum starvation increased Fig. Serum-starvation for 36 h resulted in karyopyknosis Fig. However, no nucleosomes were observed. SEM was then used to study the effect of serum-starvation on cell surface morphological characteristics Fig.

Control cells exhibited a uniform distribution of palpate and microvilli on their surfaces Fig. After 72 h of serum-starvation, the microvilli were absent and the cell membrane showed breakage Fig. Surface morphological characteristics of cells following A and D 0, B and E 24 and C and F 72 h of serum-starvation, detected by scanning electron microscopy. To study the effects of serum-starvation on cell ultrastructures, TEM was then performed.

Control cells appeared round, had abundant organelles and normal double-membraned nuclei Fig. Following serum-starvation, the nuclear membrane was domed outward with a sharp angle, the chromatin within the nuclei was concentrated and clustered on the inner border of cells and cell blebbing became visible Fig. In order to investigate the effects of serum-starvation on cellular apoptosis, Bcl-2 and Bax mRNA and protein expression was examined.

These results suggest that serum-deprivation induces cellular apoptosis in a time-dependent manner. Bcl-2, B-cell lymphoma 2 apoptosis regulator; Bax, Bcl-2 associated protein X apoptosis regulator. Changes to the tongue coating may reflect the condition of vitality and pathogen status in the body. Tongue squamous epithelial cells are the main component of the tongue coating, with proliferation, differentiation and apoptosis being the root cause of the formation and maintenance of tongue coating Therefore, examination of the mechanisms of the formation of tongue coating is meaningful at the cellular level.

However, very little research pertaining to cell function related to tongue coating formation has been examined, mainly due to: i The oral environment being a contaminated environment, with a low cultivation success rate; ii it is generally more difficult to obtain normal human tongue back mucosal epithelial materials because submucous tissue cannot be completely cleaned, which causes the epithelial cells to develop synchronously inside fibroblasts to different degrees 22 ; and iii epithelial cells are challenging to grow in general synthetic media because they have extremely complex nutritional requirements which are not fully achievable in a uniform culturing condition Current research has found that tongue carcinoma squamous cells, which share a source in common with tongue papillary squamous epithelial cells, cultured in vitro can imitate the biological traits of the epithelial cell in the tongue dorsum Therefore, the present study aimed to simulate tongue coating cell apoptosis by culturing tongue carcinoma squamous cells in a serum-starvation environment in vitro , to provide a theoretical basis for clarification of the molecular mechanisms relating to the formation of tongue coating.

There are an increasing number of reports detailing the influence of serum-starvation on cells. An increase in cell apoptosis has been observed in some cell types following serum deprivation.

For example, goat skin fibroblast apoptosis was enhanced by 3- and fold following 48 and h serum starvation, respectively In the present study, the cellular proliferative capability was estimated by the MTT method. Since somatic cell reprogramming requires global epigenetic changes, little is known about the regulation of rDNA transcriptional activity during this process. In this study, iPSCs were used to investigate rDNA epigenetic changes occurring in four-factor-mediated reprogramming.

The established S-iPSC lines expressed pluripotency markers, and the differentiation potential was confirmed by teratomas with all three germ layers Fig.

We found that serum deprivation significantly stimulated rDNA transcription level compared with the control group. Cells were distinguished from parental cells with unmodified rDNA transcription profiles, implying active rDNA transcription.

Undoubtedly, donor cells with various differentiation statuses will influence the reprogramming efficiency [ 25 ]. However, the serum starvation group did not undergo a transient rDNA transcriptional inhibition. Conversely, the rDNA transcriptional level was reactivated directly without fluctuation Fig.

We hold the view that serum starvation promoted rDNA transcriptional activity during the early stage of reprogramming. The phenomenon could be partially explained as follows.

Fibroblasts were released to enter the cell cycle and started mitosis immediately. The activated cell proliferation resulted in a burst of protein synthesis and rDNA transcription within the initial stage of reprogramming. Second, a previous report confirmed that retroviruses required the disassembly of the nuclear envelope at mitosis in order to enter the nucleus and replicate [ 26 ]. Chen et al. Above all, this would help explain our results that cell cycle synchronization stimulated rDNA transcription reactivation throughout the reprogramming process.

Reprogramming is likely a stochastic process, and epigenetic resetting is essential to overcome the barrier to pluripotency [ 27 ]. Cells preserve an intermediate stage with similar morphology to iPSCs and ESCs but without the expression of core pluripotency markers described as partially reprogrammed cells [ 28 — 30 ].

Stable cell sorting and culture of pre-iPSCs contributes to exploring the regulation mechanism that unlocks partially reprogrammed cells into a fully reprogrammed state. Acquisition of a pre-pluripotent state is supposed to occur during the early stage of reprogramming. During the G2 and S phases, rDNA transcription was actively transcribed, and transcription is maximal during the S and G2 phases [ 32 ]. Most S-MEFs were released to the S phase simultaneously, resulting in a stimulation of rRNA and protein synthesis within the initial stage of reprogramming.

The nucleosome remodeling and deacetylation complex NuRD is a transcriptional modulator that integrates ATP-dependent chromatin remodeling and histone modifying activities [ 33 ]. NuRD has been shown to be required for regulation of Pol I transcription [ 12 ].

Important epigenetic modifications, including diverse histone modifications, are involved in transcription repression and activation [ 39 ]. Histone H3 lysine 9 H3K9 methylation was discovered as an epigenetic determinant for pre-iPSCs to establish and maintain the epigenetic barrier [ 40 ].

Above all, proper epigenetic modulation of partially reprogrammed cells might overcome the transition barrier to full reprogramming. The transcriptional activity of rRNA genes varies between cell types, metabolism conditions, and specific environmental challenges, indicating that epigenetic features change during development and differentiation. Cells under injured metabolism, such as nutrient starvation, oxidative stress, and cell senescence, have an impaired rDNA transcriptional activity, whereas a positive influence that stimulates growth and proliferation upregulates Pol I transcription [ 13 , 41 ].

Somatic cell reprogramming can be accomplished by a variety of ways, such as nuclear transplantation nuclear transfer [ 42 , 43 ], cell fusion [ 44 ], and direct reprogramming to pluripotency [ 16 ]. After nuclear transfer, a nuclear reprogramming strategy, MEFNT embryos preserved the highest methylation level However, there were opposite opinions over rDNA epigenetic remodeling involved in adult cell reprogramming.

Xenopus egg extract-mediated nuclear reprogramming has been shown to induce remodeling of chromatin and reprogram gene expression in somatic cells [ 45 , 46 ]. A previous study showed that egg extract elicited remodeling of the nuclear envelope, chromatin, and nucleolus, and resulted in a rapid and stable decrease of ribosomal gene transcription.

The downregulation of rDNA transcriptional activity here was distinct from a stress response [ 47 ]. Ling et al. Taken together, it is profoundly suggested that the distinct rDNA transcriptional phenomena hidden behind these diverse reprogramming process require further investigation.

The complicated rDNA epigenetic regulatory mechanisms may not be simplified and idealized as a simplified model. We demonstrated that cell cycle synchronization could stimulate rDNA transcription reactivation during somatic cell reprogramming into iPSCs. Our findings offer new insights into the regulation of rDNA transcriptional activity during somatic cell reprogramming and will benefit partially reprogrammed cells to overcome the epigenetic barrier to pluripotency.

Complete sequence of the kb human ribosomal DNA repeat: analysis of the intergenic spacer. Complete sequence of the kb mouse ribosomal DNA repeat: analysis of the intergenic spacer. Grummt I. Life on a planet of its own: regulation of RNA polymerase I transcription in the nucleolus. Genes Dev. Human rRNA transcription is modulated by the coordinate binding of two factors to an upstream control element.

A housekeeper with power of attorney: the rRNA genes in ribosome biogenesis. Cell Mol Life Sci. EMBO J. J Cell Biol. EMBO Rep. The nucleolar remodeling complex NoRC mediates heterochromatin formation and silencing of ribosomal gene transcription. Nat Genet. The chromatin remodeling complex NuRD establishes the poised state of rRNA genes characterized by bivalent histone modifications and altered nucleosome positions. McStay B, Grummt I. The epigenetics of rRNA genes: from molecular to chromosome biology.

Annu Rev Cell Dev Biol. Moss T. At the crossroads of growth control; making ribosomal RNA. Curr Opin Genet Dev. Takahashi K, Yamanaka S.

Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Berdasco M, Esteller M. DNA methylation in stem cell renewal and multipotency. Stem Cell Res Ther. Genomic characterization of the mouse ribosomal DNA locus. G3 Genes, Genomes, Genetics. J Biol Chem. Induction of pluripotent stem cells from fibroblast cultures.

Nat Protoc. Eichler DC, Craig N. Processing of eukaryotic ribosomal RNA.