PTEN deficiency and mutant p53 confer glucose-addiction to thyroid cancer cells: impact of glucose depletion on cell proliferation, cell survival, autophagy and cell migration

Advances in the interaction of glycolytic reprogramming with lactylation

Lactylation is a novel post-translational modification (PTM) involving proteins that is induced by lactate accumulation. Histone lysine lactylation alters chromatin spatial configuration, influencing gene transcription and regulating the expression of associated genes. This modification plays a crucial role as an epigenetic regulatory factor in the progression of various diseases. Glycolytic reprogramming is one of the most extensively studied forms of metabolic reprogramming, recognized as a key hallmark of cancer cells. It is characterized by an increase in glycolysis and the inhibition of the tricarboxylic acid (TCA) cycle, accompanied by significant lactate production and accumulation. The two processes are closely linked by lactate, which interacts in various physiological and pathological processes. On the one hand, lactylation levels generally correlate positively with the extent of glycolytic reprogramming, being directly influenced by the lactate concentration produced during glycolytic reprogramming. On the other hand, lactylation can also regulate glycolytic pathways by affecting the transcription and structural functions of essential glycolytic enzymes. This review comprehensively outlines the mechanisms of lactylation and glycolytic reprogramming and their interactions in tumor progression, immunity, and inflammation, with the aim of elucidating the relationship between glycolytic reprogramming and lactylation.

The new insights into autophagy in thyroid cancer progression

In recent decades, the incidence of thyroid cancer keeps growing at a shocking rate, which has aroused increasing concerns worldwide. Autophagy is a fundamental and ubiquitous biological event conserved in mammals including humans. Basically, autophagy is a catabolic process that cellular components including small molecules and damaged organelles are degraded for recycle to meet the energy needs, especially under the extreme conditions. The dysregulated autophagy has indicated to be involved in thyroid cancer progression. The enhancement of autophagy can lead to autophagic cell death during the degradation while the produced energies can be utilized by the rest of the cancerous tissue, thus this influence could be bidirectional, which plays either a tumor-suppressive or oncogenic role. Accordingly, autophagy can be suppressed by therapeutic agents and is thus regarded as a drug target for thyroid cancer treatments. In the present review, a brief description of autophagy and roles of autophagy in tumor context are given. We have addressed summary of the mechanisms and functions of autophagy in thyroid cancer. Some potential autophagy-targeted treatments are also summarized. The aim of the review is linking autophagy to thyroid cancer, so as to develop novel approaches to better control cancer progression.

Glycolysis Inhibition of Autophagy Drives Malignancy in Ovarian Cancer: Exacerbation by IL-6 and Attenuation by Resveratrol

Cancer cells drive the glycolytic process towards the fermentation of pyruvate into lactate even in the presence of oxygen and functioning mitochondria, a phenomenon known as the "Warburg effect". Although not energetically efficient, glycolysis allows the cancer cell to synthesize the metabolites needed for cell duplication. Autophagy, a macromolecular degradation process, limits cell mass accumulation and opposes to cell proliferation as well as to cell migration. Cancer cells corrupt cancer-associated fibroblasts to release pro-inflammatory cytokines, which in turn promote glycolysis and support the metastatic dissemination of cancer cells. In mimicking in vitro this condition, we show that IL-6 promotes ovarian cancer cell migration only in the presence of glycolysis. The nutraceutical resveratrol (RV) counteracts glucose uptake and metabolism, reduces the production of reactive oxygen species consequent to excessive glycolysis, rescues the mitochondrial functional activity, and stimulates autophagy. Consistently, the lack of glucose as well as its metabolically inert analogue 2-deoxy-D-glucose (2-DG), which inhibits hexokinase 2 (HK2), trigger autophagy through mTOR inhibition, and prevents IL-6-induced cell migration. Of clinical relevance, bioinformatic analysis of The Cancer Genome Atlas dataset revealed that ovarian cancer patients bearing mutated TP53 with low expression of glycolytic markers and IL-6 receptor, together with markers of active autophagy, display a longer overall survival and are more responsive to platinum therapy. Taken together, our findings demonstrate that RV can counteract IL-6-promoted ovarian cancer progression by rescuing glycolysis-mediated inhibition of autophagy and support the view that targeting Warburg metabolism can be an effective strategy to limit the risk for cancer metastasis.

Reprogramming of Cellular Metabolism and Its Therapeutic Applications in Thyroid Cancer

Metabolism is a series of life-sustaining chemical reactions in organisms, providing energy required for cellular processes and building blocks for cellular constituents of proteins, lipids, carbohydrates and nucleic acids. Cancer cells frequently reprogram their metabolic behaviors to adapt their rapid proliferation and altered tumor microenvironments. Not only aerobic glycolysis (also termed the Warburg effect) but also altered mitochondrial metabolism, amino acid metabolism and lipid metabolism play important roles for cancer growth and aggressiveness. Thus, the mechanistic elucidation of these metabolic changes is invaluable for understanding the pathogenesis of cancers and developing novel metabolism-targeted therapies. In this review article, we first provide an overview of essential metabolic mechanisms, and then summarize the recent findings of metabolic reprogramming and the recent reports of metabolism-targeted therapies for thyroid cancer.

Cytochrome C Oxidase Subunit 4 (COX4): A Potential Therapeutic Target for the Treatment of Medullary Thyroid Cancer

The nuclear-encoded subunit 4 of cytochrome c oxidase (COX4) plays a role in regulation of oxidative phosphorylation and contributes to cancer progression. We sought to determine the role of COX4 in differentiated (DTC) and medullary (MTC) thyroid cancers. We examined the expression of COX4 in human thyroid tumors by immunostaining and used shRNA-mediated knockdown of COX4 to evaluate its functional contributions in thyroid cancer cell lines. In human thyroid tissue, the expression of COX4 was higher in cancers than in either normal thyroid (p = 0.0001) or adenomas (p = 0.001). The level of COX4 expression correlated with tumor size (p = 0.04) and lymph-node metastases (p = 0.024) in patients with MTCs. COX4 silencing had no effects on cell signaling activation and mitochondrial respiration in DTC cell lines (FTC133 and BCPAP). In MTC-derived TT cells, COX4 silencing inhibited p70S6K/pS6 and p-ERK signaling, and was associated with decreased oxygen consumption and ATP production. Treatment with potassium cyanide had minimal effects on FTC133 and BCPAP, but inhibited mitochondrial respiration and induced apoptosis in MTC-derived TT cells. Our data demonstrated that metastatic MTCs are characterized by increased expression of COX4, and MTC-derived TT cells are vulnerable to COX4 silencing. These data suggest that COX4 can be considered as a novel molecular target for the treatment of MTC.

Causative role for defective expression of mitochondria-eating protein in accumulation of mitochondria in thyroid oncocytic cell tumors

Oncocytic cell tumor of the thyroid is composed of large polygonal cells with eosinophilic cytoplasm that is rich in mitochondria. These tumors frequently have the mutations in mitochondrial DNA encoding the mitochondrial electron transport system complex I. However, the mechanism for accumulation of abnormal mitochondria is unknown. A noncanonical mitophagy system has recently been identified, and mitochondria-eating protein (MIEAP) plays a key role in this system. We therefore hypothesized that accumulation of abnormal mitochondria could be attributed to defective MIEAP expression in these tumors. We first show that MIEAP was expressed in all the conventional thyroid follicular adenomas (FAs)/adenomatous goiters (AGs) but not in oncocytic FAs/AGs; its expression was defective not only in oncocytic thyroid cancers but also in the majority of conventional thyroid cancers. Expression of MIEAP was not correlated with methylation status of the 5'-UTR of the gene. Our functional analysis showed that exogenously induced MIEAP, but not PARK2, reduced the amounts of abnormal mitochondria, as indicated by decreased reactive oxygen species levels, mitochondrial DNA / nuclear DNA ratios, and cytoplasmic acidification. Therefore, together with previous studies showing that impaired mitochondrial function triggers compensatory mitochondrial biogenesis that causes an increase in the amounts of mitochondria, we conclude that, in oncocytic cell tumors of the thyroid, increased abnormal mitochondria cannot be efficiently eliminated because of a loss of MIEAP expression, ie impaired MIEAP-mediated noncanonical mitophagy.

Regulators of glucose uptake in thyroid cancer cell lines

Abstract

Thyroid cancer is the most common sort of endocrine-related cancer with more prevalent in women and elderly individuals which has quickly widespread expansion in worldwide over the recent decades. Common features of malignant thyroid cells are to have accelerated metabolism and increased glucose uptake to optimize their energy supply which provides a fundamental advantage for growth. In tumor cells the retaining of required energy charge for cell survival is imperative, indeed glucose transporters are enable of promoting of this task. According to this relation it has been reported the upregulation of glucose transporters in various types of cancers. Human studies indicated that poor survival can be occurred following the high levels of GLUT1 expression in tumors. GLUT-1 and GLUT3 are the glucose transporters which seems to be mainly engaged with the oncogenesis of thyroid cancer and their expression in malignant tissues is much more than in the normal one. They are promising targets for the advancement of anticancer strategies. The lack of oncosuppressors have dominant effect on the membrane expression of GLUT1 and glucose uptake. Overexpression of hypoxia inducible factors have been additionally connected with distant metastasis in thyroid cancers which mediates transcriptional regulation of glycolytic genes including GLUT1 and GLUT3. Though the physiological role of the thyroid gland is well illustrated, but the metabolic regulations in thyroid cancer remain evasive. In this study we discuss proliferation pathways of the key regulators and signaling molecules such as PI3K-Akt, HIF-1, MicroRNA, PTEN, AMPK, BRAF, c-Myc, TSH, Iodide and p53 which includes in the regulation of GLUTs in thyroid cancer cells. Incidence of deregulations in cellular energetics and metabolism are the most serious signs of cancers. In conclusion, understanding the mechanisms of glucose transportation in normal and pathologic thyroid tissues is critically important and could provide significant insights in science of diagnosis and treatment of thyroid disease.

Curative effect of xanthohumol supplementation during liver fluke-associated cholangiocarcinogenesis: Potential involvement of autophagy

Xanthohumol (XH), a plant flavonoid, was shown to attenuate cholangiocarcinoma (CCA) development induced by the liver fluke Opisthorchis viverrini (Ov) and N-dinitrosomethylamine (NDMA) in the hamster model. We investigated the possible involvement of autophagy, a self-degrading process dysregulated in cancer, in XH chemotherapeutic effect. During cholangiocarcinogenesis, the expression of LC3 (an autophagic marker) was increased in the precancerous stage and decreased in the cancerous stage. The XH-treated ON (Ov plus NDMA) group showed retarded progression of CCA along with increased expression of LC3. The possible relation between autophagy and cell death was investigated in cultured human CCA cells. XH induced apoptosis associated with reduced expression of BCL-2 and increased expression of BAX. In parallel, XH induced the autophagy flux, as testified by increased LC3-II and decreased p62, along with induction of BECLIN1 and Vps34. Inhibition of BECLIN1-dependent autophagy greatly limited XH toxicity in CCA cells. These data suggest that XH attenuates the development of CCA through overstimulation of autophagy which then precipitates apoptosis.

Non-local Parabolic and Hyperbolic Models for Cell Polarisation in Heterogeneous Cancer Cell Populations

Tumours consist of heterogeneous populations of cells. The sub-populations can have different features, including cell motility, proliferation and metastatic potential. The interactions between clonal sub-populations are complex, from stable coexistence to dominant behaviours. The cell–cell interactions, i.e. attraction, repulsion and alignment, processes critical in cancer invasion and metastasis, can be influenced by the mutation of cancer cells. In this study, we develop a mathematical model describing cancer cell invasion and movement for two polarised cancer cell populations with different levels of mutation. We consider a system of non-local hyperbolic equations that incorporate cell–cell interactions in the speed and the turning behaviour of cancer cells, and take a formal parabolic limit to transform this model into a non-local parabolic model. We then investigate the possibility of aggregations to form, and perform numerical simulations for both hyperbolic and parabolic models, comparing the patterns obtained for these models.

PTEN dephosphorylates AKT to prevent the expression of GLUT1 on plasmamembrane and to limit glucose consumption in cancer cells

GLUT1 is the facilitative transporter playing the major role in the internalization of glucose. Basally, GLUT1 resides on vesicles located in a para-golgian area, and is translocated onto the plasmamembrane upon activation of the PI3KC1-AKT pathway. In proliferating cancer cells, which demand a high quantity of glucose for their metabolism, GLUT1 is permanently expressed on the plasmamembrane. This is associated with the abnormal activation of the PI3KC1-AKT pathway, consequent to the mutational activation of PI3KC1 and/or the loss of PTEN. The latter, in fact, could antagonize the phosphorylation of AKT by limiting the availability of Phosphatidylinositol (3,4,5)-trisphosphate. Here, we asked whether PTEN could control the plasmamembrane expression of GLUT1 also through its protein-phosphatase activity on AKT. Experiments of co-immunoprecipitation and in vitro de-phosphorylation assay with homogenates of cells transgenically expressing the wild type or knocked-down mutants (lipid-phosphatase, protein-phosphatase, or both) isoforms demonstrated that indeed PTEN physically interacts with AKT and drives its dephosphorylation, and so limiting the expression of GLUT1 at the plasmamembrane. We also show that growth factors limit the ability of PTEN to dephosphorylate AKT. Our data emphasize the fact that PTEN acts in two distinct steps of the PI3k/AKT pathway to control the expression of GLUT1 at the plasmamembrane and, further, add AKT to the list of the protein substrates of PTEN.

Metabolic Alterations of Thyroid Cancer as Potential Therapeutic Targets

Thyroid cancer (TC) is the most frequent endocrine tumor with a growing incidence worldwide. Besides the improvement of diagnosis, TC increasing incidence is probably due to environmental factors and lifestyle modifications. The actual diagnostic criteria for TC classification are based on fine needle biopsy (FNAB) and histological examination following thyroidectomy. Since in some cases it is not possible to make a proper diagnosis, classical approach needs to be supported by additional biomarkers. Recently, new emphasis has been given to the altered cellular metabolism of proliferating cancer cells which require high amount of glucose for energy production and macromolecules biosynthesis. Also TC displays alteration of energy metabolism orchestrated by oncogenes activation and tumor suppressors inactivation leading to abnormal proliferation. Furthermore, TC shows significant metabolic heterogeneity within the tumor microenvironment and metabolic coupling between cancer and stromal cells. In this review we focus on the current knowledge of metabolic alterations of TC and speculate that targeting TC metabolism may improve current therapeutic protocols for poorly differentiated TC. Future studies will further deepen the actual understandings of the metabolic phenotype of TC cells and will give the chance to provide novel prognostic biomarkers and therapeutic targets in tumors with a more aggressive behavior.

The metabolic cross-talk between epithelial cancer cells and stromal fibroblasts in ovarian cancer progression: Autophagy plays a role

Cancer and stromal cells, which include (cancer‐associated) fibroblasts, adipocytes, and immune cells, constitute a mixed cellular ecosystem that dynamically influences the behavior of each component, creating conditions that ultimately favor the emergence of malignant clones. Ovarian cancer cells release cytokines that recruit and activate stromal fibroblasts and immune cells, so perpetuating a state of inflammation in the stroma that hampers the immune response and facilitates cancer survival and propagation. Further, the stroma vasculature impacts the metabolism of the cells by providing or limiting the availability of oxygen and nutrients. Autophagy, a lysosomal catabolic process with homeostatic and prosurvival functions, influences the behavior of cancer cells, affecting a variety of processes such as the survival in metabolic harsh conditions, the invasive growth, the development of immune and chemo resistance, the maintenance of stem‐like properties, and dormancy. Further, autophagy is involved in the secretion and the signaling of promigratory cytokines. Cancer‐associated fibroblasts can influence the actual level of autophagy in ovarian cancer cells through the secretion of pro‐inflammatory cytokines and the release of autophagy‐derived metabolites and substrates. Interrupting the metabolic cross‐talk between cancer cells and cancer‐associated fibroblasts could be an effective therapeutic strategy to arrest the progression and prevent the relapse of ovarian cancer.

The protein restriction mimetic Resveratrol is an autophagy inducer stronger than amino acid starvation in ovarian cancer cells

The potential benefit of nutrient starvation in the prevention and treatment of cancer is presently under consideration. Resveratrol (RV), a dietary polyphenol acting as a protein (caloric) restriction mimetic, could substitute for amino acid starvation. The effects of starvation and of caloric restriction are mediated, among others, by autophagy, a process that contributes to cell homeostasis by promoting the lysosomal degradation of damaged and redundant self-constituents. Up-regulation of autophagy favors cell survival under nutrient shortage situation, and may drive cancer cells into a non-replicative, dormant state. Both RV and amino acid starvation effectively induced the aminoacid response and autophagy. These processes were associated with inhibition of the mTOR pathway and disruption of the BECLIN1-BCL-2 complex. The number of transcripts positively impinging on the autophagy pathway was higher in RV-treated than in starved cancer cells. Consistent with our data, it appears that RV treatment is more effective than and can substitute for starvation for inducing autophagy in cancer cells. The present findings are clinically relevant because of the potential therapeutic implications.

Resveratrol protects neuronal-like cells expressing mutant Huntingtin from dopamine toxicity by rescuing ATG4-mediated autophagosome formation

Parkinsonian-like motor deficits in Huntington's Disease (HD) patients are associated with abnormal dopamine neurotransmission in the striatum. Dopamine metabolism leads to the formation of oxidized dopamine quinones that exacerbates mitochondrial dysfunction with production of reactive oxygen species (ROS) that eventually lead to neuronal cell death. We have previously shown that dopamine-induced oxidative stress triggers apoptotic cell death in dopaminergic neuroblastoma SH-SY5Y cells hyper-expressing the mutant polyQ Huntingtin (polyQ-Htt) protein. Dopamine toxicity was paralleled by impaired autophagy clearance of the polyQ-Htt aggregates. In this study, we found that Dopamine affects the stability and function of ATG4, a redox-sensitive cysteine-protein involved in the processing of LC3, a key step in the formation of autophagosomes. Resveratrol, a dietary polyphenol with anti-oxidant and pro-autophagic properties, has shown neuroprotective potential in HD. Yet the molecular mechanism through which Resveratrol can protect HD cells against DA is not known. Here, we show that Resveratrol prevents the generation of ROS, restores the level of ATG4, allows the lipidation of LC3, facilitates the degradation of polyQ-Htt aggregates and protects the cells from Dopamine toxicity. The present findings provide a mechanistic explanation of the neuroprotective activity of Resveratrol and support its inclusion in a therapeutic regimen to slow down HD progression.

Downregulation of Notch-regulated Ankyrin Repeat Protein Exerts Antitumor Activities against Growth of Thyroid Cancer

BACKGROUND

The Notch-regulated ankyrin repeat protein (NRARP) is recently found to promote proliferation of breast cancer cells. The role of NRARP in carcinogenesis deserves extensive investigations. This study attempted to investigate the expression of NRARP in thyroid cancer tissues and assess the influence of NRARP on cell proliferation, apoptosis, cell cycle, and invasion in thyroid cancer.

METHODS

Thirty-four cases with thyroid cancer were collected from the Department of General Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine between 2011 and 2012. Immunohistochemistry was used to detect the level of NRARP in cancer tissues. Lentivirus carrying NRARP-shRNA (Lenti-NRARP-shRNA) was applied to down-regulate NRARP expression. Cell viability was tested after treatment with Lenti-NRARP-shRNA using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle distribution were determined by flow cytometry. Cell invasion was tested using Transwell invasion assay. In addition, expressions of several cell cycle-associated and apoptosis-associated proteins were examined using Western blotting after transfection. Student's t-test, one-way analysis of variance (ANOVA), or Kaplan-Meier were used to analyze the differences between two group or three groups.

RESULTS

NRARP was highly expressed in thyroid cancer tissues. Lenti-NRARP-shRNA showed significantly inhibitory activities against cell growth at a multiplicity of infection of 10 or higher (P < 0.05). Lenti-NRARP-shRNA-induced G1 arrest (BHT101: 72.57% ± 5.32%; 8305C: 75.45% ± 5.26%) by promoting p21 expression, induced apoptosis by promoting bax expression and suppressing bcl-2 expression, and inhibited cell invasion by suppressing matrix metalloproteinase-9 expression.

CONCLUSION

Downregulation of NRARP expression exerts significant antitumor activities against cell growth and invasion of thyroid cancer, that suggests a potential role of NRARP in thyroid cancer targeted therapy.

Resveratrol inhibits IL-6-induced ovarian cancer cell migration through epigenetic up-regulation of autophagy

Interleukin-6 (IL-6), a pro-inflammatory cytokine released by cancer-associated fibroblasts, has been linked to the invasive and metastatic behavior of ovarian cancer cells. Resveratrol is a naturally occurring polyphenol with the potential to inhibit cancer cell migration. Here we show that Resveratrol and IL-6 affect in an opposite manner the expression of RNA messengers and of microRNAs involved in cell locomotion and extracellular matrix remodeling associated with the invasive properties of ovarian cancer cells. Among the several potential candidates responsible for the anti-invasive effect promoted by Resveratrol, here we focused our attention on ARH-I (DIRAS3), that encodes a Ras homolog GTPase of 26-kDa. This protein is known to inhibit cell motility, and it has been shown to regulate autophagy by interacting with BECLIN 1. IL-6 down-regulated the expression of ARH-I and inhibited the formation of LC3-positive autophagic vacuoles, while promoting cell migration. On opposite, Resveratrol could counteract the IL-6 induction of cell migration in ovarian cancer cells through induction of autophagy in the cells at the migration front, which was paralleled by up-regulation of ARH-I and down-regulation of STAT3 expression. Spautin 1-mediated disruption of BECLIN 1-dependent autophagy abrogated the effects of Resveratrol, while promoting cell migration. The present data indicate that Resveratrol elicits its anti-tumor effect through epigenetic mechanisms and support its inclusion in the chemotherapy regimen for highly aggressive ovarian cancers. © 2016 Wiley Periodicals, Inc.

PVALB diminishes [Ca2+] and alters mitochondrial features in follicular thyroid carcinoma cells through AKT/GSK3β pathway

We have identified previously a panel of markers (C1orf24, ITM1 and PVALB) that can help to discriminate benign from malignant thyroid lesions. C1orf24 and ITM1 are specifically helpful for detecting a wide range of thyroid carcinomas, and PVALB is particularly valuable for detecting the benign Hürthle cell adenoma. Although these markers may ultimately help patient care, the current understanding of their biological functions remains largely unknown. In this article, we investigated whether PVALB is critical for the acquisition of Hürthle cell features and explored the molecular mechanism underlying the phenotypic changes. Through ectopic expression of PVALB in thyroid carcinoma cell lines (FTC-133 and WRO), we demonstrated that PVALB sequesters free cytoplasmic Ca(2+), which ultimately lowers calcium levels and precludes endoplasmic reticulum (ER) Ca(2+) refilling. These results were accompanied by induced expression of PERK, an ER stress marker. Additionally, forced expression of PVALB reduces Ca(2+) inflow in the mitochondria, which can in turn cause changes in mitochondria morphology, increase mitochondria number and alter subcellular localization. These findings share striking similarity to those observed in Hürthle cell tumors. Moreover, PVALB inhibits cell growth and induces cell death, most likely through the AKT/GSK-3β. Finally, PVALB expression coincides with Ca(2+) deposits in HCA tissues. Our data support the hypothesis that the loss of PVALB plays a role in the pathogenesis of thyroid tumors.

The fine tuning of metabolism, autophagy and differentiation during in vitro myogenesis

Although the mechanisms controlling skeletal muscle homeostasis have been identified, there is a lack of knowledge of the integrated dynamic processes occurring during myogenesis and their regulation. Here, metabolism, autophagy and differentiation were concomitantly analyzed in mouse muscle satellite cell (MSC)-derived myoblasts and their cross-talk addressed by drug and genetic manipulation. We show that increased mitochondrial biogenesis and activation of mammalian target of rapamycin complex 1 inactivation-independent basal autophagy characterize the conversion of myoblasts into myotubes. Notably, inhibition of autophagic flux halts cell fusion in the latest stages of differentiation and, conversely, when the fusion step of myocytes is impaired the biogenesis of autophagosomes is also impaired. By using myoblasts derived from p53 null mice, we show that in the absence of p53 glycolysis prevails and mitochondrial biogenesis is strongly impaired. P53 null myoblasts show defective terminal differentiation and attenuated basal autophagy when switched into differentiating culture conditions. In conclusion, we demonstrate that basal autophagy contributes to a correct execution of myogenesis and that physiological p53 activity is required for muscle homeostasis by regulating metabolism and by affecting autophagy and differentiation.

Proteomic maps of breast cancer subtypes

Systems-wide profiling of breast cancer has almost always entailed RNA and DNA analysis by microarray and sequencing techniques. Marked developments in proteomic technologies now enable very deep profiling of clinical samples, with high identification and quantification accuracy. We analysed 40 oestrogen receptor positive (luminal), Her2 positive and triple negative breast tumours and reached a quantitative depth of >10,000 proteins. These proteomic profiles identified functional differences between breast cancer subtypes, related to energy metabolism, cell growth, mRNA translation and cell–cell communication. Furthermore, we derived a signature of 19 proteins, which differ between the breast cancer subtypes, through support vector machine (SVM)-based classification and feature selection. Remarkably, only three proteins of the signature were associated with gene copy number variations and eleven were also reflected on the mRNA level. These breast cancer features revealed by our work provide novel insights that may ultimately translate to development of subtype-specific therapeutics.

Breast cancers have been extensively studied at the genomic and transcriptomic levels in the hope of tailoring therapeutic regimens. Here the authors generate deep coverage proteomes from several clinical breast cancer samples, and use machine learning techniques to uncover biological processes altered in specific cancer subtypes.

The potential anticancer effect of beta-blockers and the genetic variations involved in the interindividual difference

β-ARs are extensively spread in different tissues of our body, which could be activated by neurotransmitters norepinephrine and epinephrine to mediate physiological function and abnormal states including cancer. Recently, β-AR blockers could have significant implications in cancer therapy. But the precise molecular mechanisms are far from being fully understood. Through identifying the β-AR system signal pathways relevant to cancer, we can understand the mechanisms of β-blockers used for cancer treatment. What's more, retrospective clinical data made β-blockers jump out of the traditional field of cardiovascular disease and strengthened our confidence in cancer therapy. At last, genetic studies of β-adrenergic system offered crucial genes to analyze the effects of polymorphisms on cancer susceptibility, therapy response and prognosis of cancer patients.

VER-246608, a novel pan-isoform ATP competitive inhibitor of pyruvate dehydrogenase kinase, disrupts Warburg metabolism and induces context-dependent cytostasis in cancer cells

Pyruvate dehydrogenase kinase (PDK) is a pivotal enzyme in cellular energy metabolism that has previously been implicated in cancer through both RNAi based studies and clinical correlations with poor prognosis in several cancer types.

Here, we report the discovery of a novel and selective ATP competitive pan-isoform inhibitor of PDK, VER-246608. Consistent with a PDK mediated MOA, VER-246608 increased pyruvate dehydrogenase complex (PDC) activity, oxygen consumption and attenuated glycolytic activity. However, these effects were only observed under D-glucose-depleted conditions and required almost complete ablation of PDC E1α subunit phosphorylation. VER-246608 was weakly anti-proliferative to cancer cells in standard culture media; however, depletion of either serum or combined D-glucose/L-glutamine resulted in enhanced cellular potency. Furthermore, this condition-selective cytostatic effect correlated with reduced intracellular pyruvate levels and an attenuated compensatory response involving deamination of L-alanine. In addition, VER-246608 was found to potentiate the activity of doxorubicin. In contrast, the lipoamide site inhibitor, Nov3r, demonstrated sub-maximal inhibition of PDK activity and no evidence of cellular activity.

These studies suggest that PDK inhibition may be effective under the nutrient-depleted conditions found in the tumour microenvironment and that combination treatments should be explored to reveal the full potential of this therapeutic strategy.

The overexpression of SOX2 affects the migration of human teratocarcinoma cell line NT2/D1

The altered expression of the SOX2 transcription factor is associated with oncogenic or tumor suppressor functions in human cancers. This factor regulates the migration and invasion of different cancer cells. In this study we investigated the effect of constitutive SOX2 overexpression on the migration and adhesion capacity of embryonal teratocarcinoma NT2/D1 cells derived from a metastasis of a human testicular germ cell tumor. We detected that increased SOX2 expression changed the speed, mode and path of cell migration, but not the adhesion ability of NT2/D1 cells. Additionally, we demonstrated that SOX2 overexpression increased the expression of the tumor suppressor protein p53 and the HDM2 oncogene. Our results contribute to the better understanding of the effect of SOX2 on the behavior of tumor cells originating from a human testicular germ cell tumor. Considering that NT2/D1 cells resemble cancer stem cells in many features, our results could contribute to the elucidation of the role of SOX2 in cancer stem cells behavior and the process of metastasis.

Autophagy in thyroid cancer: present knowledge and future perspectives

Thyroid cancer is the most common endocrine malignancy. Despite having a good prognosis in the majority of cases, when the tumor is dedifferentiated it does no longer respond to conventional treatment with radioactive iodine, the prognosis worsens significantly. Treatment options for advanced, dedifferentiated disease are limited and do not cure the disease. Autophagy, a process of self-digestion in which damaged molecules or organelles are degraded and recycled, has emerged as an important player in the pathogenesis of different diseases, including cancer. The role of autophagy in thyroid cancer pathogenesis is not yet elucidated. However, the available data indicate that autophagy is involved in several steps of thyroid tumor initiation and progression as well as in therapy resistance and therefore could be exploited for therapeutic applications. The present review summarizes the most recent data on the role of autophagy in the pathogenesis of thyroid cancer and we will provide a perspective on how this process can be targeted for potential therapeutic approaches and could be further explored in the context of multimodality treatment in cancer and personalized medicine.