Translationally controlled tumor protein (TCTP) in the human prostate and prostate cancer cells: expression, distribution, and calcium binding activity

The multifaceted potential of TPT1 as biomarker and therapeutic target

Tumor Protein Translationally-Controlled 1 (TPT1) is a highly conserved gene found across eukaryotic species. The protein encoded by TPT1 is ubiquitously expressed both intracellularly and extracellularly across various tissues, and its levels are influenced by various external factors. TPT1 interacts with several key proteins, including p53, MCL1, and immunoglobulins, highlighting its crucial role in cellular processes. The dysregulation of TPT1 expression has been documented in a wide range of diseases, indicating its potential as a valuable biomarker. Additionally, targeting TPT1 presents a promising approach for treating and preventing various conditions. This review will assess the potential of TPT1 as a biomarker and evaluate the effectiveness of current strategies designed to inhibit TPT1 in disease contexts.

Single nucleotide polymorphisms cumulating to genetic variation for fertility in crossbred (Bos taurus × Bos indicus) bull spermatozoa

Spermatozoa from high-fertile (HF) and low-fertile (LF) breeding bulls were subjected to high-throughput next-generation sequencing to identify important Single nucleotide polymorphisms (SNPs) and novel variants associated with fertility. A total of 77,038 genome-wide SNPs were identified, among which, 10,788 were novel variants. A total of 42,290 and 34,748 variants were recorded with 6115 and 4673 novel variants in in HF and LF bulls, respectively. Higher number of SNPs were identified in HF compared to LF bulls. GO analysis of filtered genes with significant variations in HF bulls indicated their involvement in oxidative phosphorylation and metabolic pathways. GO analysis of filtered genes with significant variation in LF bulls revealed their involvement in Ca2++ ion binding, structural constituent of ribosome, and biological processes like translation and ribosomal small subunit assembly. The study identified SNPs in candidate genes including TPT1, BOLA-DRA, CD74, RPS17, RPS28, RPS29, RPL14, RPL13, and RPS27A, which are linked to sperm functionality, survival, oxidative stress, and bull fertility. The identified SNPs could be used in selection of bulls for high fertility and the variation in these genes could be established as an explanation for the fertility differences in bulls upon validation in large number of bulls.

A nematode effector inhibits plant immunity by preventing cytosolic free Ca2+ rise

The Meloidogyne enterolobii effector MeTCTP is a member of the translationally controlled tumour protein (TCTP) family, involved in M. enterolobii parasitism. In this study, we found that MeTCTP forms homodimers and, in this form, binds calcium ions (Ca²⁺ ). At the same time, Ca²⁺ could induce homodimerization of MeTCTP. We further identified that MeTCTP inhibits the increase of cytosolic free Ca²⁺ concentration ([Ca²⁺ ]_cyt ) in plant cells and suppresses plant immune responses. This includes suppression of reactive oxygen species burst and cell necrosis, further promoting M. enterolobii parasitism. Our results have elucidated that the effector MeTCTP can directly target Ca²⁺ by its homodimeric form and prevent [Ca²⁺ ]_cyt rise in plant roots, revealing a novel mechanism utilized by plant pathogens to suppress plant immunity.

Translationally controlled tumor protein: the mediator promoting cancer invasion and migration and its potential clinical prospects

Translationally controlled tumor protein (TCTP) is a highly conserved multifunctional protein localized in the cytoplasm and nucleus of eukaryotic cells. It is secreted through exosomes and its degradation is associated with the ubiquitin-proteasome system (UPS), heat shock protein 27 (Hsp27), and chaperone-mediated autophagy (CMA). Its structure contains three α‍-helices and eleven β‍-strands, and features a helical hairpin as its hallmark. TCTP shows a remarkable similarity to the methionine-R-sulfoxide reductase B (MsrB) and mammalian suppressor of Sec4 (Mss4/Dss4) protein families, which exerts guanine nucleotide exchange factor (GEF) activity on small guanosine triphosphatase (GTPase) proteins, suggesting that some functions of TCTP may at least depend on its GEF action. Indeed, TCTP exerts GEF activity on Ras homolog enriched in brain (Rheb) to boost the growth and proliferation of Drosophila cells. TCTP also enhances the expression of cell division control protein 42 homolog (Cdc42) to promote cancer cell invasion and migration. Moreover, TCTP regulates cytoskeleton organization by interacting with actin microfilament (MF) and microtubule (MT) proteins and inducing the epithelial-mesenchymal transition (EMT) process. In essence, TCTP promotes cancer cell movement. It is usually highly expressed in cancerous tissues and thus reduces patient survival; meanwhile, drugs can target TCTP to reduce this effect. In this review, we summarize the mechanisms of TCTP in promoting cancer invasion and migration, and describe the current inhibitory strategy to target TCTP in cancerous diseases.

Targeting TCTP sensitizes tumor to T cell-mediated therapy by reversing immune-refractory phenotypes

Immunotherapy has emerged as a powerful approach to cancer treatment. However, immunotherapeutic resistance limits its clinical application. Therefore, identifying immune-resistant factors, which can be targeted by clinically available drugs and it also can be a companion diagnostic marker, is needed to develop combination strategies. Here, using the transcriptome data of patients, and immune-refractory tumor models, we identify TCTP as an immune-resistance factor that correlates with clinical outcome of anti-PD-L1 therapy and confers immune-refractory phenotypes, decreased T cell trafficking to the tumor and resistance to cytotoxic T lymphocyte-mediated tumor cell killing. Mechanistically, TCTP activates the EGFR-AKT-MCL-1/CXCL10 pathway by phosphorylation-dependent interaction with Na, K ATPase. Furthermore, treatment with dihydroartenimsinin, the most effective agent impending the TCTP-mediated-refractoriness, synergizes with T cell-mediated therapy to control immune-refractory tumors. Thus, our findings suggest a role of TCTP in promoting immune-refractoriness, thereby encouraging a rationale for combination therapies to enhance the efficacy of T cell-mediated therapy.

Translationally controlled tumor protein (TCTP) regulates several cellular processes, including apoptosis, and is overexpressed in several cancer types. Here, the authors report that high levels of TCTP are associated with poor response to anti-PD-L1 and that TCTP targeting increases the efficacy of T cell-mediated anti-tumor therapy.

Significance and Relevance of Spermatozoal RNAs to Male Fertility in Livestock

Livestock production contributes to a significant part of the economy in developing countries. Although artificial insemination techniques brought substantial improvements in reproductive efficiency, male infertility remains a leading challenge in livestock. Current strategies for the diagnosis of male infertility largely depend on the evaluation of semen parameters and fail to diagnose idiopathic infertility in most cases. Recent evidences show that spermatozoa contains a suit of RNA population whose profile differs between fertile and infertile males. Studies have also demonstrated the crucial roles of spermatozoal RNA (spRNA) in spermatogenesis, fertilization, and early embryonic development. Thus, the spRNA profile may serve as unique molecular signatures of fertile sperm and may play pivotal roles in the diagnosis and treatment of male fertility. This manuscript provides an update on various spRNA populations, including protein-coding and non-coding RNAs, in livestock species and their potential role in semen quality, particularly sperm motility, freezability, and fertility. The contribution of seminal plasma to the spRNA population is also discussed. Furthermore, we discussed the significance of rare non-coding RNAs (ncRNAs) such as long ncRNAs (lncRNAs) and circular RNAs (circRNAs) in spermatogenic events.

CircRNA_103948 inhibits autophagy in colorectal cancer in a ceRNA manner

Circular RNA (circRNA) is implicated in many types of cancer; however, the expression and role of circRNAs in colorectal cancer (CRC) remains poorly understood. In this study, a circRNA microarray assay was performed to detect abnormally expressed circRNAs in CRC, and tissue arrays were used to determine the prognosis for CRC patients. Cell counting kit-8, clone formation, wound healing, and transwell assays were used to evaluate cell functions in vitro, and a mouse subcutaneous tumor model was designed for in vivo analysis. Autophagy was observed using confocal laser scanning and transmission electron microscopy. The expression of circRNA, miRNA, and mRNA was detected using qPCR; western blot, RNA pull-down assay, RNA immunoprecipitation, and dual luciferase assessment were applied for mechanistic studies. We found that circRNA_103948 expression is upregulated in CRC tissues, compared with adjacent normal tissues, and associated with poor prognosis. Knockdown of circRNA_103948 suppressed CRC both in vitro and in vivo. Mechanistically, circRNA_103948 could directly bind to miR-1236-3p and relieve suppression of the target TPT1. Furthermore, circRNA_103948 inhibited autophagy of CRC cells. Taken together, circRNA_103948 knockdown inhibited CRC cell growth by targeting miR-1236-3p/TPT1 axis-mediated autophagy. Thus, the circRNA_103948/miR-1236-3p/TPT1 axis affects CRC progression via modulation of autophagy.

Dhaka: variational autoencoder for unmasking tumor heterogeneity from single cell genomic data

MOTIVATION

Intra-tumor heterogeneity is one of the key confounding factors in deciphering tumor evolution. Malignant cells exhibit variations in their gene expression, copy numbers and mutation even when originating from a single progenitor cell. Single cell sequencing of tumor cells has recently emerged as a viable option for unmasking the underlying tumor heterogeneity. However, extracting features from single cell genomic data in order to infer their evolutionary trajectory remains computationally challenging due to the extremely noisy and sparse nature of the data.

RESULTS

Here we describe 'Dhaka', a variational autoencoder method which transforms single cell genomic data to a reduced dimension feature space that is more efficient in differentiating between (hidden) tumor subpopulations. Our method is general and can be applied to several different types of genomic data including copy number variation from scDNA-Seq and gene expression from scRNA-Seq experiments. We tested the method on synthetic and six single cell cancer datasets where the number of cells ranges from 250 to 6000 for each sample. Analysis of the resulting feature space revealed subpopulations of cells and their marker genes. The features are also able to infer the lineage and/or differentiation trajectory between cells greatly improving upon prior methods suggested for feature extraction and dimensionality reduction of such data.

AVAILABILITY AND IMPLEMENTATION

All the datasets used in the paper are publicly available and developed software package and supporting info is available on Github https://github.com/MicrosoftGenomics/Dhaka.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Comparative Transcriptomic Analysis of Spermatozoa From High- and Low-Fertile Crossbred Bulls: Implications for Fertility Prediction

Crossbred bulls produced by crossing Bos taurus and Bos indicus suffer with high incidence of infertility/subfertility problems; however, the etiology remains poorly understood. The uncertain predictability and the inability of semen evaluation techniques to maintain constant correlation with fertility demand for alternate methods for bull fertility prediction. Therefore, in this study, the global differential gene expression between high- and low-fertile crossbred bull sperm was assessed using a high-throughput RNA sequencing technique with the aim to identify transcripts associated with crossbred bull fertility. Crossbred bull sperm contained transcripts for 13,563 genes, in which 2,093 were unique to high-fertile and 5,454 were unique to low-fertile bulls. After normalization of data, a total of 776 transcripts were detected, in which 84 and 168 transcripts were unique to high-fertile and low-fertile bulls, respectively. A total of 176 transcripts were upregulated (fold change > 1) and 209 were downregulated (<1) in low-fertile bulls. Gene ontology analysis identified that the sperm transcripts involved in the oxidative phosphorylation pathway and biological process such as multicellular organism development, spermatogenesis, and in utero embryonic development were downregulated in low-fertile crossbred bull sperm. Sperm transcripts upregulated and unique to low-fertile bulls were majorly involved in translation (biological process) and ribosomal pathway. With the use of RT-qPCR, selected sperm transcripts (n = 12) were validated in crossbred bulls (n = 12) with different fertility ratings and found that the transcriptional abundance of ZNF706, CRISP2, TNP2, and TNP1 genes was significantly (p < 0.05) lower in low-fertile bulls than high-fertile bulls and was positively (p < 0.05) correlated with conception rate. It is inferred that impaired oxidative phosphorylation could be the predominant reason for low fertility in crossbred bulls and that transcriptional abundance of ZNF706, CRISP2, TNP2, and TNP1 genes could serve as potential biomarkers for fertility in crossbred bulls.

Overexpression of translationally controlled tumor protein ameliorates metabolic imbalance and increases energy expenditure in mice

Background/Objectives

Translationally controlled tumor protein (TCTP) exhibits numerous biological functions. It has been shown to be involved in the regulation of glucose. However, its specific role in metabolism has not yet been clearly elucidated. Here, we aimed to assess the effect of TCTP overexpression on metabolic tissues and systemic energy metabolism.

Subjects/Methods

We investigated whether TCTP can ameliorate the metabolic imbalance that causes obesity using TCTP-overexpressing transgenic (TCTP TG) mice. The mice were subjected to biochemical, morphological, physiological and protein expression studies to define the role of TCTP in metabolic regulation in response to normal chow diet (NCD) compared to high-fat diet (HFD) conditions, and cold environment.

Results

We found that TCTP TG mice show improved metabolic homeostasis under both of NCD and HFD conditions with simultaneous enhancements in glucose tolerance and insulin sensitivity. In particular, we found coincident increases in energy expenditure with significant upregulation of uncoupling protein 1 (UCP1) in the brown adipose tissue (BAT). Moreover, TCTP overexpressing mice exhibit significantly enhanced adaptive thermogenesis of BAT in response to cold exposure.

Conclusions

Overexpression of TCTP ameliorated systemic metabolic homeostasis by stimulating UCP1-mediated thermogenesis in the BAT. This suggests that TCTP may function as a modulator of energy expenditure. This study suggests TCTP may serve as a therapeutic target for obesity and obesity-associated metabolic disorders including type 2 diabetes.

Mice immunization with Trypanosoma brucei gambiense translationally controlled tumor protein modulates immunoglobulin and cytokine production, as well as parasitaemia and mice survival after challenge with the parasite

Fighting trypanosomiasis with an anti-trypanosome vaccine is ineffective, the parasite being protected by a Variable Surface Glycoprotein (VSG) whose structure is modified at each peak of parasitaemia, which allows it to escape the host's immune defenses. However, the host immunization against an essential factor for the survival of the parasite or the expression of its pathogenicity could achieve the same objective. Here we present the results of mouse immunization against the Translationally Controlled Tumor Protein (TCTP), a protein present in the Trypanosoma brucei gambiense (Tbg) secretome, the parasite responsible for human trypanosomiasis. Mice immunization was followed by infection with Tbg parasites. The production of IgG, IgG1 and IgG2a begun after the second TCTP injection and was dose-dependant, the maximum level of anti-TCTP antibodies remained stable up to 4 days post-infection and then decreased. Regarding cytokines (IL-2, 4, 6, 10, INFγ, TNFα), the most striking result was their total suppression after immunization with the highest TCTP dose. Compared to the control group, the immunized mice displayed a reduced first peak of parasitaemia, a 100% increase in the time to onset of the second peak, and an increased time of mice survival. The effect of immunization was only transient but demonstrated the likely important role that TCTP plays in host-parasite interactions and that some key parasite proteins could reduce infection impact.

The mRNA of TCTP functions as a sponge to maintain homeostasis of TCTP protein levels in hepatocellular carcinoma

Translationally controlled tumor protein (TCTP) is a highly conserved protein that accumulated in the tumorigenesis of various malignancies. Despite the important role of TCTP protein in tumor progression, the precise function and underlying mechanistic regulation of TCTP mRNA in hepatocellular carcinoma (HCC) remain unclear. In this study, we found that TCTP protein was overexpressed in HCC patients but TCTP mRNA expression levels were reversed. TCTP knockout HCC cells exhibited attenuated abilities of proliferation, migration, and invasion. The knockdown of TCTP by siRNA effectively reduced TCTP mRNA levels but not protein levels in HCC cells. Moreover, although the constitutive knockdown of TCTP inhibited almost 80% of TCTP protein expression levels in tumors of wildtype transgenic mice (TCTP KD/WT), partial restoration of TCTP protein expression was observed in the tumors of heterozygous TCTP mice (TCTP KD/TCTP±). The blockage of mRNA synthesis with ActD stimulated TCTP protein expression in HCC cells. In contrast, combined treatment with ActD and CHX or MG132 treatment alone did not lead to the TCTP protein accumulation in cells. Furthermore, following the introduction of exogenous TCTP in cells and orthotopic HCC tumor models, the endogenous TCTP protein did not change with the recombinational TCTP expression and kept a rather stable level. Dual-luciferase assays revealed that the coding sequence of TCTP mRNA functions as a sponge to regulate the TCTP protein expression. Collectively, our results indicated that the TCTP mRNA and protein formed a closed regulatory circuit and works as a buffering system to keep the homeostasis of TCTP protein levels in HCC.

RNA-Seq analysis reveals functionally relevant coding and non-coding RNAs in crossbred bull spermatozoa

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RNA-Seq analysis was done to characterize the transcriptome of crossbred bull spermatozoa.

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Among the 13,814 transcripts detected, 431 had FPKM > 1 and 13,673 had FPKM > 0 or < 1.

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Coding and non-coding RNAs account for 13,145 (95.15%) and 152 (1.1%), respectively.

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Sperm transcripts were mainly related to ribosome, oxidative phosphorylation and spliceosome pathways.

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qPCR analysis showed individual variations in transcriptional abundance of selected genes.

Sperm, which are believed to be transcriptionally and translationally inactive, synthesize RNA and proteins before there is gradual disappearance of the ribosome during chromatin compaction. Sperm transfer several functionally relevant transcripts to the oocyte, controlling maternal-zygotic transition and embryonic development. The present study was undertaken to profile and analyze sperm transcripts comprehensively using Next Generation Ribonucleic acid sequencing technology in Holstein Friesian x Tharparkar crossbred bulls. The results from global transcriptomic profiling revealed transcripts for 13,814 genes; of which 431 transcripts were expressed with >1 FPKM and 13,383 transcripts were expressed with >0 or <1 FPKM. The abundant mRNA transcripts of crossbred bull sperm were PRM1 and HMGB4. Gene ontology of transcripts with>1 FPKM revealed there was a major involvement in the structural constituent of ribosomes and translation. Results from pathway enrichment indicated the connection between ribosome, oxidative phosphorylation and spliceosome pathways and the transcripts of crossbred bull spermatozoa. The transcriptional abundance of selected genes, validated using RT-qPCR, indicated significant variations between bulls. Collectively, it may be inferred that the transcripts in crossbred bull sperm were heavily implicated in functions such as the structural constituent of ribosomes and translation, and pathways such as ribosome, oxidative phosphorylation and spliceosome. Further studies using larger sample sizes are required to understand the possible implications of transcriptomic variations on semen quality and fertility.

Analysis of translation control tumor protein related to deltamethrin stress in Drosophila kc cells

The translation control tumor protein (TCTP) is a kind of conservative, common and important molecule, several functions (such as regulating cell cycle, apoptosis and calcium binding) have been reported. However, few academic researches for role of TCTP in insecticides stress were made so far. In this research, Drosophila kc cells treated with different doses of deltamethrin at different times, indicated that the expression of TCTP reached the highest level when the cells were treated with 20 ppm of deltamethrin at 24 h. The results showed that TCTP expression is associated with deltamethrin stress. To investigate the functional relationship between this gene and deltamethrin resistance, RNA interference (RNAi) and cell transfection were utilized. TCTP knockdown significantly reduced the level of resistance of RNAi-treated cells, and the overexpressions of TCTP in Drosophila kc cells conferred a degree of protection against deltamethrin. Flow cytometry data showed increased apoptosis rate of RNAi-treated cells and decreased apoptosis following cell transfection. These results represent the first evidence that TCTP plays an important role in the regulation of deltamethrin resistance. Therefore, this study could help us to elucidate the environmental toxicity of deltamethrin and new target genes associated with resistance.

History of Histamine-Releasing Factor (HRF)/Translationally Controlled Tumor Protein (TCTP) Including a Potential Therapeutic Target in Asthma and Allergy

Histamine-releasing factor (HRF) also known as translationally controlled tumor protein (TCTP) is a highly conserved, ubiquitous protein that has both intracellular and extracellular functions. Here we will highlight the subcloning of the molecule, its clinical implications, as well as an inducible-transgenic mouse. Particular attention will be paid to its extracellular functioning and its potential role as a therapeutic target in asthma and allergy. The cells and the cytokines that are produced when stimulated or primed by HRF/TCTP will be detailed as well as the downstream signaling pathway that HRF/TCTP elicits. While it was originally thought that HRF/TCTP interacted with IgE, the finding that cells not binding IgE also respond to HRF/TCTP called this interaction into question. HRF/TCTP or at least its mouse counterpart appears to interact with some, but not all IgE and IgG molecules. HRF/TCTP has been shown to activate multiple human cells including basophils, eosinophils, T cells, and B cells. Since many of the cells that are activated by HRF/TCTP participate in the allergic response, the extracellular functions of HRF/TCTP could exacerbate the allergic, inflammatory cascade. Particularly exciting is that small molecule agonists of the phosphatase SHIP-1 have been shown to modulate the P13 kinase/AKT pathway and may control inflammatory disorders. This review discusses this possibility in light of HRF/TCTP.

A Potential Role for Exosomal Translationally Controlled Tumor Protein Export in Vascular Remodeling in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by increased proliferation and resistance to apoptosis of pulmonary vascular cells. Increased expression of translationally controlled tumor protein (TCTP), a prosurvival and antiapoptotic mediator, has recently been demonstrated in patients with heritable PAH; however, its role in the pathobiology of PAH remains unclear. Silencing of TCTP in blood outgrowth endothelial cells (BOECs) isolated from control subjects led to significant changes in morphology, cytoskeletal organization, increased apoptosis, and decreased directionality during migration. Because TCTP is also localized in extracellular vesicles, we isolated BOEC-derived extracellular vesicles (exosomes and microparticles) by sequential ultracentrifugation. BOECs isolated from patients harboring BMPR2 mutations released more exosomes than those derived from control subjects in proapoptotic conditions. Furthermore, TCTP expression was significantly higher in exosomes than in microparticles, indicating that TCTP is mainly exported via exosomes. Coculture assays demonstrated that exosomes transferred TCTP from ECs to pulmonary artery smooth muscle cells, suggesting a role for endothelial-derived TCTP in conferring proliferation and apoptotic resistance. In an experimental model of PAH, rats treated with monocrotaline demonstrated increased concentrations of TCTP in the lung and plasma. Consistent with this finding, we observed increased circulating TCTP levels in patients with idiopathic PAH compared with control subjects. Therefore, our data suggest an important role for TCTP in regulating the critical vascular cell phenotypes that have been implicated in the pathobiology of PAH. In addition, this research implicates TCTP as a potential biomarker for the onset and development of PAH.

Blood feeding tsetse flies as hosts and vectors of mammals-pre-adapted African Trypanosoma: current and expected research directions

Research on the zoo-anthropophilic blood feeding tsetse flies' biology conducted, by different teams, in laboratory settings and at the level of the ecosystems- where also co-perpetuate African Trypanosoma- has allowed to unveil and characterize key features of tsetse flies' bacterial symbionts on which rely both (a) the perpetuation of the tsetse fly populations and (b) the completion of the developmental program of the African Trypanosoma. Transcriptomic analyses have already provided much information on tsetse fly genes as well as on genes of the fly symbiotic partners Sodalis glossinidius and Wigglesworthia, which account for the successful onset or not of the African Trypanosoma developmental program. In parallel, identification of the non- symbiotic bacterial communities hosted in the tsetse fly gut has recently been initiated: are briefly introduced those bacteria genera and species common to tsetse flies collected from distinct ecosystems, that could be further studied as potential biologicals preventing the onset of the African Trypanosoma developmental program. Finally, future work will need to concentrate on how to render tsetse flies refractory, and the best means to disseminate them in the field in order to establish an overall refractory fly population.

LncRNA LINC01446 promotes glioblastoma progression by modulating miR-489-3p/TPT1 axis

Accumulating evidence indicates that long noncoding RNA (lncRNA) is implicated in human diseases, including cancers. However, how lncRNA regulates glioblastoma (GBM) progression is poorly understood. Our study revealed a novel lncRNA LINC01446 whose expression was elevated in GBM tissues. Besides, high expression of LINC01446 indicated a poor prognosis in GBM patients. Functionally, LINC01446 knockdown dramatically inhibited GBM cell proliferation, arrested cell-cycle progression and attenuated invasion in vitro. Furthermore, the xenograft mouse model showed that LINC01446 silence led to impaired tumor growth in vivo. Mechanistically, bioinformatics analysis showed that LINC01446 acted as a sponge for miR-489-3p which targeted TPT1. Though inhibiting miR-489-3p availability, LINC01446 promoted TPT1 expression in GBM cells. Rescue experiments demonstrated that restoration of TPT1 could significantly rescued the effects of LINC01446 silence or miR-489-3p overexpression. Taken together, this study demonstrates a novel singling pathway of LINC01446/miR-489-3p/TPT1 cascade that regulates GBM progression.

Proteomic analysis reveals that pheophorbide a-mediated photodynamic treatment inhibits prostate cancer growth by hampering GDP-GTP exchange of ras-family proteins

BACKGROUND

We previously reported that pheophorbide a (PhA), excited by 630 nm light, significantly inhibited the growth of prostate cancer cells. In this study, we employed whole-cell proteomics to investigate photodynamic treatment (PDT)-related proteins.

METHODS

Two-dimensional gel electrophoresis (2-DE) coupled with tandem mass spectrometry was employed to reveal the proteins involved in PhA-mediated PDT in LNCaP and PC-3 prostate cancer cells.

RESULTS

After PhA-PDT treatment, decreased expression of translationally-controlled tumor protein (TCTP) was found in both PC-3 and LNCaP whole-cell proteomes. In contrast, human rab GDP dissociation inhibitor (GDI) in LNCaP cells and ras-related homologs GDI in PC-3 cells were up-regulated.

CONCLUSIONS

GDP-GTP exchange is an underlying target of photodynamic treatment in prostate cancer cells.

Upregulation of TCTP is associated with cholangiocarcinoma progression and metastasis

In order to investigate the role of translationally-controlled tumor protein (TCTP) in cholangiocarcinoma (CCA) progression and metastasis, TCTP protein staining in paraffin-embedded sections of human CCA tissue samples was examined using immunohistochemistry, and its expression was subsequently compared with clinicopathological parameters. Small interfering RNA (siRNA) targeting TCTP (siTCTP) were transfected into CCA cell lines to evaluate its effects on cellular functions. The proliferation, tumorigenicity and migration abilities of the transfected cells were measured using sulforhodamine B, clonogenic and would healing assays, respectively. The protein levels of TCTP and its associated molecules were evaluated by western blot analysis. Of the 119 individual cases of CCA tissues analyzed, high TCTP scores were significantly correlated with overall metastasis (P=0.044) and a shorter survival time (P<0.001). Multivariate proportional hazards analysis revealed that TCTP is an independent indicator of poor prognosis in CCA (hazard ratio =2.864; P<0.001). siTCTP transfection suppressed CCA cell growth and migration abilities, compared with the control cells (P<0.01). The siTCTP reduced the protein levels of focal adhesion kinase (FAK), phospho-FAK, nuclear factor kappa-light-chain-enhancer of activated B cells and matrix metalloproteinase 9, suggesting potential roles of TCTP in regulating CCA progression and metastasis. In conclusion, the upregulation of TCTP is clinically significant in patients with CCA, serving roles in CCA progression, particularly in cell survival and metastasis. Suppression of TCTP may serve as a potential target in CCA prevention and treatment.

Knockdown of translationally controlled tumor protein inhibits growth, migration and invasion of lung cancer cells

AIM

To investigate the role of translationally controlled tumor protein (TCTP) in lung cancer development.

MAIN METHODS

A549 and HCC827 cells were transfected with shRNA specifically targeting TCTP mRNA. Cell growth was assessed by colony formation assay and cell counting kit-8. Cell cycle and apoptosis were analyzed by flow cytometry. Cell migration and invasion was measured by scratch and transwell assays. In vivo tumorigenicity was evaluated by tumor xenografts in nude mice.

KEY FINDINGS

TCTP-silenced cells displayed a reduced ability of colony formation and a lower rate of proliferation in vitro. Knockdown of TCTP arrested cell cycle at G1 phase and led to downregulated expression of cyclins B1, D1 and E. Moreover, silencing of TCTP induced apoptosis and altered the levels of apoptosis-regulatory proteins such as cleaved caspase-3, Bcl-2, Bax and p53. Silencing of TCTP also inhibited migration and invasion of lung cancer cells. In addition, TCTP-silenced A549 cells, when subcutaneously inoculated in nude mice, formed tumors at a significantly slower rate.

SIGNIFICANCE

Our in vitro and in vivo data indicate that silencing of TCTP inhibits growth, migration and invasion of lung cancer cells. Thus, TCTP may be a potential target for lung cancer therapy.

Translationally controlled tumor protein (TCTP) is required for TGF-β1 induced epithelial to mesenchymal transition and influences cytoskeletal reorganization

Epithelial-mesenchymal transition (EMT) is a programed course of developmental changes resulting in the acquisition of invasiveness and mobility in cells. In cancer, this course is used by epithelial cells to attain movability. Translationally controlled tumor protein (TCTP) has been extensively characterized following the observation on tumor reversion ensuing its depletion. However, the role of TCTP in cancer progression is still elusive. Here, we demonstrate for the first time that TCTP is a target of transforming growth factor-β1 (TGF-β1), a key regulator of EMT in A549 cells. We here present changes in expression patterns of intermediate filament markers (vimentin and cytokeratin 18a) of EMT following TCTP knockdown or over expression. The TCTP over-expression in cancer cells is associated with mesenchymal characters, while downregulation promotes the epithelial markers in the cells. Interaction of TCTP with β-catenin seems to stabilize β-catenin, preparative to its nuclear localization highlighting a role for β-catenin signaling in EMT. Moreover, the induction of urokinase plasminogen activator (uPA) following ectopic expression of TCTP leads to destabilization of ECM. The cells knocked down for TCTP show diminished invasiveness and migration under TGF-β1 treatment. The present results for the first time demonstrate that TGF-β1 dependent TCTP expression is required for EMT in cells.

Characterization of recombinant Trypanosoma brucei gambiense Translationally Controlled Tumor Protein (rTbgTCTP) and its interaction with Glossina midgut bacteria

In humans, sleeping sickness (i.e. Human African Trypanosomiasis) is caused by the protozoan parasites Trypanosoma brucei gambiense (Tbg) in West and Central Africa, and T. b. rhodesiense in East Africa. We previously showed in vitro that Tbg is able to excrete/secrete a large number of proteins, including Translationally Controlled Tumor Protein (TCTP). Moreover, the tctp gene was described previously to be expressed in Tbg-infected flies. Aside from its involvement in diverse cellular processes, we have investigated a possible alternative role within the interactions occurring between the trypanosome parasite, its tsetse fly vector, and the associated midgut bacteria. In this context, the Tbg tctp gene was synthesized and cloned into the baculovirus vector pAcGHLT-A, and the corresponding protein was produced using the baculovirus Spodoptera frugicola (strain 9) / insect cell system. The purified recombinant protein rTbgTCTP was incubated together with bacteria isolated from the gut of tsetse flies, and was shown to bind to 24 out of the 39 tested bacteria strains belonging to several genera. Furthermore, it was shown to affect the growth of the majority of these bacteria, especially when cultivated under microaerobiosis and anaerobiosis. Finally, we discuss the potential for TCTP to modulate the fly microbiome composition toward favoring trypanosome survival.

Translationally controlled tumour protein (TCTP) from tomato and Nicotiana benthamiana is necessary for successful infection by a potyvirus

Translationally controlled tumour protein (TCTP) is a ubiquitously distributed protein in eukaryotes, involved in the regulation of several processes, including cell cycle progression, cell growth, stress protection, apoptosis and maintenance of genomic integrity. Its expression is induced during the early stages of tomato (Solanum lycopersicum) infection by the potyvirus Pepper yellow mosaic virus (PepYMV, a close relative of Potato virus Y). Tomato TCTP is a protein of 168 amino acids, which contains all the conserved domains of the TCTP family. To study the effects of TCTP silencing in PepYMV infection, Nicotiana benthamiana plants were silenced by virus-induced gene silencing (VIGS) and transgenic tomato plants silenced for TCTP were obtained. In the early stages of infection, both tomato and N. benthamiana silenced plants accumulated less virus than control plants. Transgenic tomato plants showed a drastic reduction in symptoms and no viral accumulation at 14 days post-inoculation. Subcellular localization of TCTP was determined in healthy and systemically infected N. benthamiana leaves. TCTP was observed in both the nuclei and cytoplasm of non-infected cells, but only in the cytoplasm of infected cells. Our results indicate that TCTP is a growth regulator necessary for successful PepYMV infection and that its localization is altered by the virus, probably to favour the establishment of virus infection. A network with putative interactions that may occur between TCTP and Arabidopsis thaliana proteins was built. This network brings together experimental data of interactions that occur in other eukaryotes and helps us to discuss the possibilities of TCTP involvement in viral infection.

TCTP regulates spindle assembly during postovulatory aging and prevents deterioration in mouse oocyte quality

If no fertilization occurs for a prolonged time following ovulation, oocytes experience a time-dependent deterioration in quality both in vivo and in vitro due to processes called postovulatory aging. Because the postovulatory aging of oocytes has marked detrimental effects on embryo development and offspring, many efforts have been made to unveil the underlying mechanisms. Here we showed that translationally controlled tumor protein (TCTP) regulates spindle assembly during postovulatory aging and prevents deterioration in mouse oocyte quality. Spindle dynamics decreased with reduced TCTP level during aging of mouse oocytes. Knockdown of TCTP accelerated the reduction of spindle dynamics, accompanying with aging-related deterioration of oocyte quality. Conversely, overexpression of TCTP prevented aging-associated decline of spindle dynamics. Moreover, the aging-related abnormalities in oocytes were rescued after TCTP overexpression, thereby improving fertilization competency and subsequent embryo development. Therefore, our results demonstrate that TCTP-mediated spindle dynamics play a key role in maintaining oocyte quality during postovulatory aging and overexpression of TCTP is sufficient to prevent aging-associated abnormalities in mouse oocytes.

Lipid-oligonucleotide conjugates improve cellular uptake and efficiency of TCTP-antisense in castration-resistant prostate cancer

Translationally controlled tumor protein (TCTP) has been implicated in a plethora of important cellular processes related to cell growth, cell cycle progression, malignant transformation and inhibition of apoptosis. Therefore, TCTP is now recognized as a potential therapeutic target in several cancers including prostate, breast and lung cancers. We previously showed that TCTP is overexpressed in castration-resistant prostate cancer (CRPC), and it has been implicated resistance to treatment. Recently, we developed TCTP antisense oligonucleotides (ASOs) to inhibit TCTP expression. However, the intracellular delivery and silencing activity of these oligonucleotides remains a challenge, and depend on the use of transfection agents and delivery systems. Here we show that lipid-modified ASO (LASOs) has improved penetration and efficiency in inhibiting TCTP expression in the absence of additional transfection agents, both in vitro and in vivo. Transfection with TCTP-LASO led to rapid and prolonged internalization via macropinocytosis, TCTP downregulation and significant decreased cell viability. We also show that lipid-modification led to delayed tumor progression in CRPC xenografts models, with no significant toxic effects observed.

Function of translationally controlled tumor protein (TCTP) in Eudrilus eugeniae regeneration

TCTP (Translationally Controlled Tumour Protein) is a multifunctional protein that plays a role in the development, immune system, tumour reversion, and maintenance of stem cells. The mRNA of the Tpt1 gene is over-expressed during liver regeneration. But, the function of the protein in regeneration is not known. To study the role of the protein in regeneration, the earthworm Eudrilus eugeniae was chosen. First, the full length cDNA of the Tpt1 gene was sequenced. The size of the cDNA is 504 bp and the protein has 167 amino acids. The highest level of TCTP expression was documented in the worm after three days of regeneration. The protein was found to be expressed specifically in the epithelial layer of the skin. During regeneration, the protein expression was found to be the highest at the tip of blastema. The pharmacological suppression of TCTP using nutlin-3 and TCTP RNAi experiments resulted in the failure of the regeneration process. The suppression of TCTP caused the arrest of proliferation in posterior amputated worms. The severe cell death was documented in the amputated region of nutlin-3 injected worm. The silencing of TCTP has blocked the modification of clitellar segments. The experiments confirm that TCTP has major functions in the upstream signalling of cell proliferation in the early regeneration process in E. eugeniae.

TPT1 (tumor protein, translationally-controlled 1) negatively regulates autophagy through the BECN1 interactome and an MTORC1-mediated pathway

TPT1/TCTP (tumor protein, translationally-controlled 1) is highly expressed in tumor cells, known to participate in various cellular activities including protein synthesis, growth and cell survival. In addition, TPT1 was identified as a direct target of the tumor suppressor TP53/p53 although little is known about the mechanism underlying the anti-survival function of TPT1. Here, we describe a role of TPT1 in the regulation of the MTORC1 pathway through modulating the molecular machinery of macroautophagy/autophagy. TPT1 inhibition induced cellular autophagy via the MTORC1 and AMPK pathways, which are inhibited and activated, respectively, during treatment with the MTOR inhibitor rapamycin. We also found that the depletion of TPT1 potentiated rapamycin-induced autophagy by synergizing with MTORC1 inhibition. We further demonstrated that TPT1 knockdown altered the BECN1 interactome, a representative MTOR-independent pathway, to stimulate autophagosome formation, via downregulating BCL2 expression through activating MAPK8/JNK1, and thereby enhancing BECN1-phosphatidylinositol 3-kinase (PtdIns3K)-UVRAG complex formation. Furthermore, reduced TPT1 promoted autophagic flux by modulating not only early steps of autophagy but also autophagosome maturation. Consistent with in vitro findings, in vivo organ analysis using Tpt1 heterozygote knockout mice showed that autophagy is enhanced because of haploinsufficient TPT1 expression. Overall, our study demonstrated the novel role of TPT1 as a negative regulator of autophagy that may have potential use in manipulating various diseases associated with autophagic dysfunction.

TCTP Has a Crucial Role in the Different Stages of Prostate Cancer Malignant Progression

Prostate cancer (PC) is the second most common cause of cancer-related mortality in men in the western world after lung cancer. Many patients are not candidates for resection given the advanced stage of their cancer. The primary treatment for advanced PC is the castration therapy which supresses the production of androgens, hormone that promotes PC growth. Despite the efficiency of the castration therapy, most patients develop castration resistant disease which remains uncurable. Clearly, novel approaches are required to effectively treat castration resistant PC (CRPC). New strategies that identify the molecular mechanisms by which PC becomes resistant to conventional therapies may enable the identification of novel therapeutic targets that could improve clinical outcome. Recent studies have demonstrated the implication of TCTP's over-expression in PC and CRPC, and its role in resistance to treatment. TCTP's interaction with p53 and their negative feedback loop regulation have also been described to be causal for PC progression and invasion. A novel nanotherapy that inhibits TCTP has been developed as a new therapeutical strategy in CRPC. This chapter will highlight the role of TCTP as new therapeutic target in PC, in particular, therapy-resistant advanced PC and report the development of novel nanotherapy against TCTP that restore treatment-sensitivity in CRPC that deserve to be tested in clinical trial.

Structural Insights into TCTP and Its Interactions with Ligands and Proteins

The 19-24 kDa Translationally Controlled Tumor Protein (TCTP) is involved in a wide range of molecular interactions with biological and nonbiological partners of various chemical compositions such as proteins, peptides, nucleic acids, carbohydrates, or small molecules. TCTP is therefore an important and versatile binding platform. Many of these protein-protein interactions have been validated, albeit only few received an in-depth structural characterization. In this chapter, we will focus on the structural analysis of TCTP and we will review the available literature regarding its interaction network from a structural perspective.

The Translational Controlled Tumour Protein TCTP: Biological Functions and Regulation

The Translational Controlled Tumour Protein TCTP (gene symbol TPT1, also called P21, P23, Q23, fortilin or histamine-releasing factor, HRF) is a highly conserved protein present in essentially all eukaryotic organisms and involved in many fundamental cell biological and disease processes. It was first discovered about 35 years ago, and it took an extended period of time for its multiple functions to be revealed, and even today we do not yet fully understand all the details. Having witnessed most of this history, in this chapter, I give a brief overview and review the current knowledge on the structure, biological functions, disease involvements and cellular regulation of this protein.TCTP is able to interact with a large number of other proteins and is therefore involved in many core cell biological processes, predominantly in the response to cellular stresses, such as oxidative stress, heat shock, genotoxic stress, imbalance of ion metabolism as well as other conditions. Mechanistically, TCTP acts as an anti-apoptotic protein, and it is involved in DNA-damage repair and in cellular autophagy. Thus, broadly speaking, TCTP can be considered a cytoprotective protein. In addition, TCTP facilitates cell division through stabilising the mitotic spindle and cell growth through modulating growth signalling pathways and through its interaction with the proteosynthetic machinery of the cell. Due to its activities, both as an anti-apoptotic protein and in promoting cell growth and division, TCTP is also essential in the early development of both animals and plants.Apart from its involvement in various biological processes at the cellular level, TCTP can also act as an extracellular protein and as such has been involved in modulating whole-body defence processes, namely in the mammalian immune system. Extracellular TCTP, typically in its dimerised form, is able to induce the release of cytokines and other signalling molecules from various types of immune cells. There are also several examples, where TCTP was shown to be involved in antiviral/antibacterial defence in lower animals. In plants, the protein appears to have a protective effect against phytotoxic stresses, such as flooding, draught, too high or low temperature, salt stress or exposure to heavy metals. The finding for the latter stress condition is corroborated by earlier reports that TCTP levels are considerably up-regulated upon exposure of earthworms to high levels of heavy metals.Given the involvement of TCTP in many biological processes aimed at maintaining cellular or whole-body homeostasis, it is not surprising that dysregulation of TCTP levels may promote a range of disease processes, foremost cancer. Indeed a large body of evidence now supports a role of TCTP in at least the most predominant types of human cancers. Typically, this can be ascribed to both the anti-apoptotic activity of the protein and to its function in promoting cell growth and division. However, TCTP also appears to be involved in the later stages of cancer progression, such as invasion and metastasis. Hence, high TCTP levels in tumour tissues are often associated with a poor patient outcome. Due to its multiple roles in cancer progression, TCTP has been proposed as a potential target for the development of new anti-cancer strategies in recent pilot studies. Apart from its role in cancer, TCTP dysregulation has been reported to contribute to certain processes in the development of diabetes, as well as in diseases associated with the cardiovascular system.Since cellular TCTP levels are highly regulated, e.g. in response to cell stress or to growth signalling, and because deregulation of this protein contributes to many disease processes, a detailed understanding of regulatory processes that impinge on TCTP levels is required. The last section of this chapter summarises our current knowledge on the mechanisms that may be involved in the regulation of TCTP levels. Essentially, expression of the TPT1 gene is regulated at both the transcriptional and the translational level, the latter being particularly advantageous when a rapid adjustment of cellular TCTP levels is required, for example in cell stress responses. Other regulatory mechanisms, such as protein stability regulation, may also contribute to the regulation of overall TCTP levels.

Targeting TCTP with Sertraline and Thioridazine in Cancer Treatment

We have initially demonstrated in knocking down experiments that decreasing TCTP in cancer cells leads in some tissues to cell death while in others to a complete reorganization of the tumor into architectural structures reminiscent of normal ones. Based on these experiments and a series of other findings confirming the key role of TCTP in cancer, it became important to find pharmacological compounds to inhibit its function, and this became for us a priority. In the present text, we explain in detail the experiments that were performed and the perspectives of sertraline in cancer treatment, as this became today a reality with a clinical study that started in collaboration with Columbia University and Johns Hopkins University.

Elusive Role of TCTP Protein and mRNA in Cell Cycle and Cytoskeleton Regulation

Translationally Controlled Tumor-associated Protein (TCTP) is a small, 23 kDa multifunctional and ubiquitous protein localized both in the cytoplasm and in the nucleus of eukaryotic cells. It is evolutionarily highly conserved. Certain aspects of its structure show remarkable similarities to guanine nucleotide-free chaperons Mss4 and Dss4 suggesting that at least some functions of TCTP may depend on its chaperon-like action on other proteins. Besides other functions, TCTP is clearly involved in cell cycle regulation. It is also regulated in a cell-cycle-dependent manner suggesting a reciprocal interaction between this protein and the cell cycle-regulating machinery. TCTP also interacts with the cytoskeleton, mostly with actin microfilaments (MFs) and microtubules (MTs). It regulates the cytoskeleton organization and through this action it also influences cell shape and motility. The exact role of TCTP in cell cycle and cytoskeleton regulation is certainly not fully understood. In this chapter, we summarize recent data on cell cycle and cytoskeletal aspects of TCTP regulatory role.

Translationally-controlled tumor protein activates the transcription of Oct-4 in kidney-derived stem cells

The molecular mechanisms underlying translationally-controlled tumor protein (TCTP) in the activation of octamer-binding transcription factor 4 (Oct-4) in kidney-derived stem cells have not been characterized. The aim of the present study was to identify the transcriptional activation of Oct-4 by TCTP in kidney-derived stem cells. Homology-directed repair cDNA inserted into Fisher 344 transgenic (Tg) rats and the mouse strain 129/Svj were used for the experiments. Diphtheria toxin (DT; 10 ng/kg) injected into the Tg rats created the kidney injury, which was rapidly restored by the activation of kidney-derived stem cells. Kidney-derived stem cells were isolated from the DT-injured Tg rats using cell culture techniques. The co-expression of Oct-4 and TCTP were observed in the isolated kidney-derived stem cells. Immunoblotting and reverse transcription-polymerase chain reaction analysis of TCTP null mutant (TCTP^-/^-) embryos at day 9.5 (E9.5) demonstrated the absence of co-expression of Oct-4 and TCTP, but expression of paired box-2 was detected. This was in contrast with the E9.5 control embryos, which expressed all three proteins. In conclusion, the results of the present study demonstrated that TCTP activates the transcription of Oct-4 in kidney-derived stem cells, as TCTP^-/^- embryos exhibited knock down of TCTP and Oct-4 without disturbing the expression of Pax-2 The characteristics and functional nature of TCTP in association with Oct-4 in kidney-derived stem cells was identified.

Potential role of S-adenosylmethionine in osteosarcoma development

The metastatic form of osteosarcoma is a life threatening one since it metastasizes to the lungs. The major cause of metastatic osteosarcoma is hypomethylation of numerous genes that undergo overexpression to enable the progression of the disease. In the present study, S-adenosylmethionine (SAM), a predominant methyl donor, was administered to find out its effects on osteosarcoma progression. As evidence of tumor suppression, the SAM-treated mouse tissue was analyzed histologically, which exemplifies the control that SAM has over abnormal cell proliferation, especially on primary osteosarcoma, but it lacks positive effects on metastatic osteosarcoma. At the molecular level, the successful inhibition of primary osteosarcoma was found to be associated with a lower expression of Sox2, a protein highly expressed in osteosarcoma stem cells, along with an upregulated expression of TCTP. The data suggest that the administration of SAM has a positive role in treating primary osteosarcoma, but it has no role in suppressing metastatic osteosarcoma. The decreased expression of Sox2 together with upregulation of TCTP following SAM administration indicates that SAM has a control over primary osteosarcoma.

TCTP regulates spindle microtubule dynamics by stabilizing polar microtubules during mouse oocyte meiosis

Dynamic changes in spindle structure and function are essential for maintaining genomic integrity during the cell cycle. Spindle dynamics are highly dependent on several microtubule-associated proteins that coordinate the dynamic behavior of microtubules, including microtubule assembly, stability and organization. Here, we show that translationally controlled tumor protein (TCTP) is a novel microtubule-associated protein that regulates spindle dynamics during meiotic maturation. TCTP was expressed and widely distributed in the cytoplasm with strong enrichment at the spindle microtubules during meiosis. TCTP was found to be phosphorylated during meiotic maturation, and was exclusively localized to the spindle poles. Knockdown of TCTP impaired spindle organization without affecting chromosome alignment. These spindle defects were mostly due to the destabilization of the polar microtubules. However, the stability of kinetochore microtubules attached to chromosomes was not affected by TCTP knockdown. Overexpression of a nonphosphorylable mutant of TCTP disturbed meiotic maturation, stabilizing the spindle microtubules. In addition, Plk1 was decreased by TCTP knockdown. Taken together, our results demonstrate that TCTP is a microtubule-associating protein required to regulate spindle microtubule dynamics during meiotic maturation in mouse oocytes.

The biochemistry of blister fluid from pediatric burn injuries: proteomics and metabolomics aspects

Burn injury is a prevalent and traumatic event for pediatric patients. At present, the diagnosis of burn injury severity is subjective and lacks a clinically relevant quantitative measure. This is due in part to a lack of knowledge surrounding the biochemistry of burn injuries and that of blister fluid. A more complete understanding of the blister fluid biochemistry may open new avenues for diagnostic and prognostic development. Burn insult induces a highly complex network of signaling processes and numerous changes within various biochemical systems, which can ultimately be examined using proteome and metabolome measurements. This review reports on the current understanding of burn wound biochemistry and outlines a technical approach for 'omics' profiling of blister fluid from burn wounds of differing severity.

Expression of Translationally Controlled Tumor Protein in Human Kidney and in Renal Cell Carcinoma

Translationally controlled tumor protein is a multifaceted protein involved in several physiological and biological functions. Its expression in normal kidney and in renal carcinomas, once corroborated by functional data, may add elements to elucidate renal physiology and carcinogenesis. In this study, translationally controlled tumor protein expression was evaluated by quantitative real time polymerase chain reaction and western blotting, and its localization was examined by immunohistochemistry on 84 nephrectomies for cancer. In normal kidney protein expression was found in the cytoplasm of proximal and distal tubular cells, in cells of the thick segment of the loop of Henle, and in urothelial cells of the pelvis. It was also detectable in cells of renal carcinoma with different pattern of localization (membranous and cytoplasmic) depending on tumor histotype. Our data may suggest an involvement of translationally controlled tumor protein in normal physiology and carcinogenesis. However, functional in vitro and in vivo studies are needed to verify this hypothesis.

TCTP Expression After Rat Spinal Cord Injury: Implications for Astrocyte Proliferation and Migration

Translationally controlled tumor protein (TCTP) is a ubiquitous and highly conserved protein which plays a role in cell proliferation and growth, apoptosis, and cell cycle regulation. However, its expression and function in spinal cord injury (SCI) are still unknown. Here, we demonstrated that expression of TCTP was dynamic changed after acute spinal cord injury. Our results showed that TCTP gradually increased, reached a peak at 3 day, and then declined to basal levels at 14 days after spinal cord injury. Upregulation of TCTP was accompanied with an increase in the levels of proliferation proteins such as PCNA. Immunofluorescent labeling also showed that TCTP located in astrocytes and traumatic SCI induced TCTP colocalizated with PCNA. These results indicated that TCTP might play an important role in astrocyte proliferation. To further probe the role of TCTP, TCTP-specific siRNA-transfected astrocytes showed significant decrease of primary astrocyte proliferation. Surprisingly, TCTP knockdown also reduced primary astrocyte migration, as the reorganization of microtubules and F-actin was disturbed after siRNA transfection. All above indicated that TCTP might play a crucial role in astrocyte proliferation and migration. Collectively, our data suggested that TCTP might play important roles in CNS pathophysiology after SCI.

Characterization of antiproliferative potential and biological targets of a copper compound containing 4'-phenyl terpyridine

Several copper complexes have been assessed as anti-tumor agents against cancer cells. In this work, a copper compound [Cu(H2O){OS(CH3)2}L](NO3)2 incorporating the ligand 4'-phenyl-terpyridine antiproliferative activity against human colorectal, hepatocellular carcinomas and breast adenocarcinoma cell lines was determined, demonstrating high cytotoxicity. The compound is able to induce apoptosis and a slight delay in cancer cell cycle progression, probably by its interaction with DNA and induction of double-strand pDNA cleavage, which is enhanced by oxidative mechanisms. Moreover, proteomic studies indicate that the compound induces alterations in proteins involved in cytoskeleton maintenance, cell cycle progression and apoptosis, corroborating its antiproliferative potential.

LB100, a small molecule inhibitor of PP2A with potent chemo- and radio-sensitizing potential

Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase that plays a significant role in mitotic progression and cellular responses to DNA damage. While traditionally viewed as a tumor suppressor, inhibition of PP2A has recently come to attention as a novel therapeutic means of driving senescent cancer cells into mitosis and promoting cell death via mitotic catastrophe. These findings have been corroborated in numerous studies utilizing naturally produced compounds that selectively inhibit PP2A. To overcome the known human toxicities associated with these compounds, a water-soluble small molecule inhibitor, LB100, was recently developed to competitively inhibit the PP2A protein. This review summarizes the pre-clinical studies to date that have demonstrated the anti-cancer activity of LB100 via its chemo- and radio-sensitizing properties. These studies demonstrate the tremendous therapeutic potential of LB100 in a variety of cancer types. The results of an ongoing phase 1 trial are eagerly anticipated.

Immunization of mice with Plasmodium TCTP delays establishment of Plasmodium infection

Translationally controlled tumour protein (TCTP) may play an important role in the establishment or maintenance of parasitemia in a malarial infection. In this study, the potential of TCTP as a malaria vaccine was investigated in two trials. In the initial vaccine trial, Plasmodium falciparum TCTP (PfTCTP) was expressed in Saccharomyces cerevisiae and used to immunize BALB/c mice. Following challenge with Plasmodium yoelii YM, parasitemia was significantly reduced during the early stages of infection. In the second vaccine trial, the TCTP from P. yoelii and P. berghei was expressed in Escherichia coli and used in several mouse malaria models. A significant reduction in parasitemia in the early stages of infection was observed in BALB/c mice challenged with P. yoelii YM. A significantly reduced parasitemia at each day leading up to a delayed and reduced peak parasitemia was also observed in BALB/c mice challenged with the nonlethal Plasmodium chabaudi (P.c.) chabaudi AS. These results suggest that TCTP has an important role for parasite establishment and may be important for pathogenesis.

Translationally controlled tumor protein induces epithelial to mesenchymal transition and promotes cell migration, invasion and metastasis

Translationally controlled tumor protein (TCTP), is a highly conserved protein involved in fundamental processes, such as cell proliferation and growth, tumorigenesis, apoptosis, pluripotency, and cell cycle regulation. TCTP also inhibits Na,K-ATPase whose subunits have been suggested as a marker of epithelial-to-mesenchymal transition (EMT), a crucial step during tumor invasiveness, metastasis and fibrosis. We hypothesized that, TCTP might also serve as an EMT inducer. This study attempts to verify this hypothesis. We found that overexpression of TCTP in a porcine renal proximal tubule cell line, LLC-PK1, induced EMT-like phenotypes with the expected morphological changes and appearance of EMT related markers. Conversely, depletion of TCTP reversed the induction of these EMT phenotypes. TCTP overexpression also enhanced cell migration via activation of mTORC2/Akt/GSK3β/β-catenin, and invasiveness by activating MMP-9. Moreover, TCTP depletion in melanoma cells significantly reduced pulmonary metastasis by inhibiting the development of mesenchymal-like phenotypes. Overall, these findings support our hypothesis that TCTP is a positive regulator of EMT and suggest that modulation of TCTP expression is a potential approach to inhibit the invasiveness and migration of cancer cells and the attendant pathologic processes including metastasis.

Translationally controlled tumor protein in prostatic adenocarcinoma: correlation with tumor grading and treatment-related changes

Prostate cancer is the second leading cause of cancer-related death. The androgen deprivation therapy is the standard treatment for advanced stages. Unfortunately, virtually all tumors become resistant to androgen withdrawal. The progression to castration-resistance is not fully understood, although a recent paper has suggested translationally controlled tumor protein to be implicated in the process. The present study was designed to investigate the role of this protein in prostate cancer, focusing on the correlation between its expression level with tumor differentiation and response to treatment. We retrieved 292 prostatic cancer specimens; of these 153 had been treated only by radical prostatectomy and 139 had undergone radical prostatectomy after neoadjuvant treatment with combined androgen blockade therapy. Non-neoplastic controls were represented by 102 prostatic peripheral zone specimens. In untreated patients, the expression of the protein, evaluated by RT-qPCR and immunohistochemistry, was significantly higher in tumor specimens than in non-neoplastic control, increasing as Gleason pattern and score progressed. In treated prostates, the staining was correlated with the response to treatment. An association between protein expression and the main clinicopathological factors involved in prostate cancer aggressiveness was identified. These findings suggest that the protein may be a promising prognostic factor and a target for therapy.

Comparative proteomics analysis of global cellular stress responses to hydroxyurea-induced DNA damage in HeLa cells

Both environmental agents and spontaneous cellular events cause serious DNA damage, threatening the integrity of the genome. In response to replication stress or genotoxic agents triggered DNA damage, degradation of p12 subunit of DNA polymerase delta (Pol δ) results in an inter-conversion between heterotetramer (Pol δ4) and heterotrimer (Pol δ3) forms and plays a significant role in DNA damage response in eukaryotic cells. In this work, we used mass spectrometry-based proteomic approach to identify those cellular stress response protein changes corresponding to the degradation of p12 in DNA-damaged HeLa cells by the treatment with hydroxyurea (HU). A total of 736 ± 13 proteins in non-treated control group and 741 ± 19 protein spots in HU-treated cells were detected, of which 34 proteins (17 up-regulated and 17 down-regulated) exhibited significantly altered protein expression levels. Their physiological roles are mainly associated with cellular components, molecular functions, and biological processes by gene ontology analysis, among which 21 proteins were mapped to KEGG pathways. They are involved in 5 primary pathways with the subsets involving 16 secondary pathways by further KEGG analysis. More interestingly, the up-regulation of translationally controlled tumor protein was further identified to be associated with p12 degradation by Western blot analysis. Our works may enlarge and broaden our view for deeply understanding how global cellular stress responds to DNA damage, which could contribute to the etiology of human cancer or other diseases that can result from loss of genomic stability.