Oleic Acid Metabolism in Response to Glucose in C. elegans.

A key response to glucose stress is an increased production of unsaturated fatty acids to balance the increase in saturated fatty acids in the membrane. The C. elegans homolog of stearoyl-CoA desaturase, FAT-7, introduces the first double bond into saturated C18 fatty acids yielding oleic acid, and is a critical regulatory point for surviving cold and glucose stress. Here, we incorporated 13C stable isotopes into the diet of nematodes and quantified the 13C-labelled fatty acid using GC-MS and HPLC/MS-MS to track its metabolic response to various concentrations of glucose. Previous work has analyzed the membrane composition of C. elegans when responding to mild glucose stress and showed few alterations in the overall fatty acid composition in the membrane. Here, in nematodes exposed to higher concentrations of glucose, a specific reduction in oleic acid and linoleic acid was observed. Using time courses and stable isotope tracing, the response of fatty acid metabolism to increasing levels of glucose stress is characterized, revealing the funneling of monounsaturated fatty acids to preserve the abundance of polyunsaturated fatty acids. Taken together, higher levels of glucose unveil a specific reduction in oleic and linolenic acid in the metabolic rewiring required to survive glucose stress.

Targeted lipidomics reveals a novel role for glucosylceramides in glucose response.

The addition of excess glucose to the diet drives a coordinated response of lipid metabolism pathways to tune the membrane composition to the altered diet. Here, we have employed targeted lipidomic approaches to quantify the specific changes in the phospholipid and sphingolipid populations that occur in elevated glucose conditions. The lipids within wild-type Caenorhabditis elegans are strikingly stable with no significant changes identified in our global mass spectrometry-based analysis. Previous work has identified ELO-5, an elongase that is critical for the synthesis of monomethyl branched-chain fatty acids (mmBCFAs), as essential for surviving elevated glucose conditions. Therefore, we performed targeted lipidomics on elo-5 RNAi-fed animals and identified several significant changes in these animals in lipid species that contain mmBCFAs as well as in species that do not contain mmBCFAs. Of particular note, we identified a specific glucosylceramide (GlcCer 17:1;O2/22:0;O) that is also significantly upregulated with glucose in wild-type animals. Furthermore, compromising the production of the glucosylceramide pool with elo-3 or cgt-3 RNAi leads to premature death in glucose-fed animals. Taken together, our lipid analysis has expanded the mechanistic understanding of metabolic rewiring with glucose feeding and has identified a new role for the GlcCer 17:1;O2/22:0;O.

Numerical Approach to Simulate the Mechanical Behavior of Biodegradable Polymers during Erosion.

Biodegradable polymers find applications in many market segments. The ability to meet mechanical requirements within a certain time range, after which it degrades and is naturally absorbed, can be used to produce short-term use products that can be easily disposable with less environmental impact. In the segment of medical devices used in regenerative medicine, these materials are used to produce temporary implants that are naturally assimilated by the human body, avoiding a removal surgery. However, the design of these temporary devices still presents great challenges, namely in the verification of the main requirement: the lifetime of the device, associated with the progressive loss of mechanical properties, until its complete erosion and assimilation. Thus, in this study, a numerical approach is proposed to simulate the polymeric device's mechanical behavior during its hydrolytic degradation by combining the hydrolysis kinetics, that depends on mechanical factors and promotes a decrease of molecular weight and consequent decrease of mechanical performance, and erosion, when molecular weight reaches a threshold value and the polymer becomes soluble and diffuses outward, resulting in mass loss and decreasing cross-sectional area, which also contributes to the mechanical performance reduction of the device. A phenomenological approach, using the combination of continuum-based hydrolytic damage for the evolution of mechanical properties that depends on the stress field and further removal of the degraded element (to simulate mass loss) was used. Both elastoplastic and hyperelastic constitutive models were applied on this study, where the material model parameters locally depend on the molecular weight.

Accelerated Aging on the Compression Properties of a Green Polyurethane Foam: Experimental and Numerical Analysis.

The aim of this work is to evaluate the changes in compression properties of a bio-based polyurethane foam after exposure to 90 °C for different periods of time, and to propose a method to extrapolate these results and use a numerical approach to predict the compression behaviour after degradation for untested conditions at different degradation times and temperatures. Bio-based polymers are an important sustainable alternative to oil-based materials. This is explained by the foaming process and the density along the material as it was possible to see in a digital image correlation analysis. After 60 days, stiffness was approximately decreased by half in both directions. The decrease in yield stress due to thermo-oxidative degradation had a minor effect in the foaming directions, changing from 352 kPa to 220 kPa after 60 days, and the transverse property was harshly impacted changing from 530 kPa to 265 kPa. The energy absorption efficiency was slightly affected by degradation. The simulation of the compression stress-strain curves were in accordance to the experimental data and made it possible to predict the changes in mechanical properties for intermediate periods of degradation time. The plateau stress for the unaged foam transverse to the foaming direction presented experimental and numerical values of 450 kPa and 470 kPa, respectively. In addition, the plateau stresses in specimens degraded for 40 days present very similar experimental and numerical results in the same direction, at 310 kPa and 300 kPa, respectively. Therefore, this paper presents important information regarding the life-span and degradation of a green PUF. It provides insights into how compression properties vary along degradation time as function of material operation temperature, according to the Arrhenius degradation equation.

Bacterial diet modulates tamoxifen-induced death via host fatty acid metabolism.

Tamoxifen is a selective estrogen receptor (ER) modulator that is used to treat ER-positive breast cancer, but that at high doses kills both ER-positive and ER-negative breast cancer cells. We recapitulate this off-target effect in Caenorhabditis elegans, which does not have an ER ortholog. We find that different bacteria dramatically modulate tamoxifen toxicity in C. elegans, with a three-order of magnitude difference between animals fed Escherichia coli, Comamonas aquatica, and Bacillus subtilis. Remarkably, host fatty acid (FA) biosynthesis mitigates tamoxifen toxicity, and different bacteria provide the animal with different FAs, resulting in distinct FA profiles. Surprisingly these bacteria modulate tamoxifen toxicity by different death mechanisms, some of which are modulated by FA supplementation and others by antioxidants. Together, this work reveals a complex interplay between microbiota, FA metabolism and tamoxifen toxicity that may provide a blueprint for similar studies in more complex mammals.

Epithelial-Mesenchymal Plasticity Induced by Discontinuous Exposure to TGFß1 Promotes Tumour Growth.

Transitions between epithelial and mesenchymal cellular states (EMT/MET) contribute to cancer progression. We hypothesize that EMT followed by MET promotes cell population heterogeneity, favouring tumour growth. We developed an EMT model by on and off exposure of epithelial EpH4 cells (E-cells) to TGFß1 that mimics phenotypic EMT (M-cells) and MET. We aimed at understanding whether phenotypic MET is accompanied by molecular and functional reversion back to epithelia by using RNA sequencing, immunofluorescence (IF), proliferation, wound healing, focus formation and mamosphere formation assays as well as cell xenografts in nude mice. Phenotypic reverted epithelial cells (RE-cells) obtained after MET induction presented epithelial morphologies and proliferation rates resembling E cells. However, the RE transcriptomic profile and IF staining of epithelial and mesenchymal markers revealed a uniquely heterogeneous mixture of cell subpopulations with a high self-renewal ability. RE cell heterogeneity was stably maintained for long periods after TGFß1 removal both in vitro and in large tumours derived from the nude mice. Overall, we show that phenotypic reverted epithelial cells (RE cells) do not return to the molecular and functional epithelial state and present mesenchymal features related to aggressiveness and cellular heterogeneity that favour tumour growth in vivo. This work strengthens epithelial cell reprogramming and cellular heterogeneity fostered by inflammatory cues as a tumour growth-promoting factor in vivo.

Breast carcinomas with osteoclast-like giant cells: a comprehensive clinico-pathological and molecular portrait and evidence of RANK-L expression.

Breast carcinomas (BC) with osteoclast-like giant cells (OGC) are rare. Despite their distinct stromal features, their molecular characteristics remain unknown. Here, we report comprehensive clinico-pathological and molecular findings for 27 patients diagnosed with BC-OGC at Institut Curie between 2000 and 2021. Seventeen (63%) cases were invasive carcinomas of no special type (IC NST) with OGC (OGC-IC NST), four (15%) were mixed or multifocal cases with and without OGC (OGC-Mixed), and six (22%) were metaplastic carcinomas with OGC (OGC-MC). All OGC-IC NST and OGC-Mixed cases were ER+ HER2- tumors (most being luminal A based on transcriptomic subtyping, when available), while all OGC-MC were triple-negative. The median age at diagnosis was 46, 45 and 62 years for OGC-IC NST, OGC-Mixed and OGC-MC, respectively. Three patients developed distant metastases (one OGC-IC NST, two OGC-Mixed), one of whom died of metastatic disease (OGC-Mixed), and one other patient died of locally advanced disease (OGC-MC). Histopathological evaluation comparing 13 OGC-IC NST and 19 control IC NST without OGC confirmed that OGC-IC NST showed significantly higher density of vessels (by CD34 immunohistochemistry (IHC)), iron deposits (Perls stain), and CD68 and CD163-positive cell infiltrates. Genomic findings for nine OGC-IC NST and four OGC-MC were consistent with the underlying histologic subtype, including activating alterations of the PI3K/AKT/mTOR pathway in 7/13 cases. Using RNA-seq data, differential gene expression analysis between OGC-IC NST (n = 7) and control IC NST without OGC (n = 7) revealed significant overexpression of TNFSF11 (RANK-L), TNFRSF11A (RANK), CSF1 (M-CSF), CSF1R, and genes encoding osteoclastic enzymes (MMP9, ACP5, CTSK, CTSB) in OGC-IC NST, while OPG (osteoprotegerin) was underexpressed. We also confirmed for the first time RANK-L expression in BC with OGC by IHC (seen in 15 out of 16 cases, and only in 2 of 16 controls without OGC). These findings could offer a rationale for further investigating RANK-L as a therapeutic target in BC with OGC.

Monomethyl branched-chain fatty acids are critical for Caenorhabitis elegans survival in elevated glucose conditions.

The maintenance of optimal membrane composition under basal and stress conditions is critical for the survival of an organism. High-glucose stress has been shown to perturb membrane properties by decreasing membrane fluidity, and the membrane sensor PAQR-2 is required to restore membrane integrity. However, the mechanisms required to respond to elevated dietary glucose are not fully established. In this study, we used a 13C stable isotope-enriched diet and mass spectrometry to better understand the impact of glucose on fatty acid dynamics in the membrane of Caenorhabditis elegans. We found a novel role for monomethyl branched-chain fatty acids (mmBCFAs) in mediating the ability of the nematodes to survive conditions of elevated dietary glucose. This requirement of mmBCFAs is unique to glucose stress and was not observed when the nematode was fed elevated dietary saturated fatty acid. In addition, when worms deficient in elo-5, the major biosynthesis enzyme of mmBCFAs, were fed Bacillus subtilis (a bacteria strain rich in mmBCFAs) in combination with high glucose, their survival rates were rescued to wild-type levels. Finally, the results suggest that mmBCFAs are part of the PAQR-2 signaling response during glucose stress. Taken together, we have identified a novel role for mmBCFAs in stress response in nematodes and have established these fatty acids as critical for adapting to elevated glucose.

Infantile Rhabdomyosarcomas With VGLL2 Rearrangement Are Not Always an Indolent Disease: A Study of 4 Aggressive Cases With Clinical, Pathologic, Molecular, and Radiologic Findings.

VGLL2-rearranged rhabdomyosarcomas (RMS) are rare low-grade tumors with only favorable outcomes reported to date. We describe 4 patients with VGLL2-rearranged RMS confirmed by molecular studies, who experienced local progression and distant metastases, including 2 with fatal outcomes. Tumors were diagnosed at birth (n=3) or at 12 months of age (n=1), and were all localized at initial diagnosis, but unresectable and therefore managed with chemotherapy and surveillance. Metastatic progression occurred from 1 to 8 years from diagnosis (median, 3.5 y). Three patients experienced multimetastatic spread and one showed an isolated adrenal metastasis. At initial diagnosis, 3 tumors displaying bland morphology were misdiagnosed as fibromatosis or infantile fibrosarcoma and initially managed as such, while 1 was a high-grade sarcoma. At relapse, 3 tumors showed high-grade morphology, while 1 retained a low-grade phenotype. Low-grade primary tumors showed only very focal positivity for desmin, myogenin, and/or MyoD1, while high-grade tumors were heterogenously or diffusely positive. Whole-exome sequencing, performed on primary and relapse samples for 3 patients, showed increased genomic instability and additional genomic alterations (eg, TP53, CDKN2A/B, FGFR4) at relapse, but no recurrent events. RNA sequencing confirmed that high-grade tumors retained VGLL2 fusion transcripts and transcriptomic profiles consistent with VGLL2-rearranged RMS. High-grade samples showed a high expression of genes encoding cell cycle proteins, desmin, and some developmental factors. These 4 cases with distinct medical history imply the importance of complete surgical resection, and suggest that RMS-type chemotherapy should be considered in unresectable cases, given the risk of high-grade transformation. They also emphasize the importance of correct initial diagnosis.

Analyzing the Role of DICER1 Germline Variations in Papillary Thyroid Carcinoma.

INTRODUCTION: DICER1 is a member of RNase III family that has a pivotal role in the biogenesis of microRNAs, being important for normal development. Dysregulation of DICER1 has been described in different human tumours; however, there is insufficient data on the risk of thyroid cancer in the presence of germline DICER1 variants, particularly when focusing on the background of papillary thyroid carcinoma (PTC). For this purpose, we ascertained the presence of DICER1 variants in 502 (PTC) cases available from The Cancer Genome Atlas (TCGA) research network in a well-characterized pathological context. MATERIAL AND METHODS: in this study we analyzed 502 samples from 502 patients, described as PTC in the TCGA database. Tumour diagnoses were re-evaluated by 2 pathologists (S.C. and M.S.-S.) on slides available from the database, and clinicopathological and demographic data was examined. Data concerning germline and sporadic DICER1 gene variants as well as frequent mutations in the genes involved in thyroid carcinogenesis (e.g., RAS and BRAFV600E) was retrieved from the database. RESULTS AND DISCUSSION: We report 1 new germline possibly pathogenic variant, besides 15 others already been identified in ClinVar. We found that the DICER1-positive PTC group more frequently includes PTC variants, namely the oncocytic, follicular, and aggressive (hobnail variant of PTC) variants. A previous association of DICER1 had been demonstrated, mainly with the follicular variant of PTC and follicular thyroid carcinomas. Tumours harbouring germline DICER1 mutations were more frequently "bilateral" and "encapsulated." The frequent association of DICER1 germline variants with other mutations associated with thyroid cancer can reflect an haploinsufficiency tumour suppressor gene function of DICER1, as suggested from the study of animal models.

BR-BCSC Signature: The Cancer Stem Cell Profile Enriched in Brain Metastases that Predicts a Worse Prognosis in Lymph Node-Positive Breast Cancer.

Brain metastases remain an unmet clinical need in breast oncology, being frequently found in HER2-overexpressing and triple-negative carcinomas. These tumors were reported to be highly cancer stem-like cell-enriched, suggesting that brain metastases probably arise by the seeding of cancer cells with stem features. Accordingly, we found that brain-tropic breast cancer cells show increased stem cell activity and tumorigenic capacity in the chick embryo choriallantoic membrane when compared to the parental cell line. These observations were supported by a significant increase in their stem cell frequency and by the enrichment for the breast cancer stem cell (BCSC) phenotype CD44+CD24-/low. Based on this data, the expression of BCSC markers (CD44, CD49f, P-cadherin, EpCAM, and ALDH1) was determined and found to be significantly enriched in breast cancer brain metastases when compared to primary tumors. Therefore, a brain (BR)-BCSC signature was defined (3-5 BCSC markers), which showed to be associated with decreased brain metastases-free and overall survival. Interestingly, this signature significantly predicted a worse prognosis in lymph node-positive patients, acting as an independent prognostic factor. Thus, an enrichment of a BCSC signature was found in brain metastases, which can be used as a new prognostic factor in clinically challenging breast cancer patients.

Tumor-infiltrating lymphocytes are associated with poor prognosis in invasive lobular breast carcinoma.

The prognostic impact of tumor-infiltrating lymphocytes (TILs) within invasive lobular carcinoma (ILC) remains to be better characterized. In estrogen receptor (ER)-negative invasive ductal carcinomas of no special type (IDC-NST), TILs are associated with good prognosis. The aim of this study was to examine TILs in ILC, with particular focus on prognostic and clinicopathologic features. A cohort comprising 459 consecutive ILCs diagnosed in a single institution from 2005 to 2008 met the eligibility criteria for this study. The percentage of tumor area occupied by TILs was quantified by two breast pathologists and categorized into three groups: no TILs, ≤5%, >5%. Clinicopathologic features were tested by Fisher's exact tests or Chi2 tests. Overall survival (OS) and invasive disease-free survival (iDFS) were estimated by Kaplan-Meier and Cox proportional hazard statistics. There were 239 TIL-negative cases, 185 cases with ≤5% TILs, and 35 cases with >5% TILs. TILs were associated with younger age, larger tumors, lymph node involvement, poor Nottingham prognostic index, HER2 amplification, multinucleation, and prominent nucleoli (p < 0.05). Poor OS was significantly associated with increasing TILs in the univariate Cox proportional hazards model (p < 0.001) and Kaplan-Meier estimator (p < 0.05, log-rank test). Similar results were observed for iDFS (p = 0.004 for Cox univariate and p = 0.005 for log-rank test). Notably, TILs can identify a subset of ILC patients with poor OS independently of molecular subtype and lymph node metastases (multivariate Cox, p < 0.001, OS hazard ratio (HR) = 4.38 and HR = 6.15, for ≤5% and >5% TILs, respectively, vs. absence of TILs). Prominent nucleoli was the only nuclear feature associated with poor OS (p = 0.05) and iDFS (p = 0.05) in univariate Cox survival analysis. TILs represent a promising new morphologic biomarker associated with poor outcome of ILC, in contrast with that observed in ER-negative IDC-NST.

The histopathology of congenital haemangioma and its clinical correlations: a long-term follow-up study of 55 cases.

AIMS: Congenital haemangiomas (CHs) can be subdivided into different subtypes [rapidly involuting CHs (RICHs), non-involuting CHs (NICHs), and partially involuting CHs (PICHs)]. During the first few days of life, RICHs may be associated with transient but sometimes marked thrombocytopenia. We sought to assess the histological aspects and clinicopathological correlations of the three subtypes. METHODS AND RESULTS: We assessed the histopathological features of 10 RICHs, 25 NICHs, and 20 PICHs, described the patients' long-term clinical outcomes, and assessed clinicopathological correlations. All CHs were located in the dermis and hypodermis, and comprised both capillary lobules (with three distinct histopathological patterns) and extralobular large vessels. Most of the extralobular vessels were abnormal veins and abnormal lymphatic vessels. We did not observe significant correlations between the CH subtype, the histopathological pattern, and the time of the histopathological assessment. Interestingly, unexpected intralobular expression of podoplanin was found in neonatal biopsies of five RICHs and PICHs. Four of these five patients had concomitant thrombocytopenia. The podoplanin staining intensity decreased over time as the thrombocytopenia resolved and the tumour shrank. CONCLUSION: The histopathological features were similar in all three subtypes of CH, and were related to the time since disease onset; we consider that RICH, PICH and NICH form a single entity and differ only in their involuting potential. Along with the transient expression of intralobular podoplanin observed in some specimens from the newborn, the lobular architecture might lead to misdiagnosis of tufted haemangioma or kaposiform haemangioendothelioma.

Design of an adjustable stance-control knee-ankle-foot orthosis for pediatric population.

Conventional knee-ankle-foot orthoses (KAFOs) are generally prescribed for children with lower limb muscle weakness and joint instabilities. The main function of KAFOs is to provide stability during gait by locking the knee in full extension. However, walking with the knee joint in a fully extended position requires excessive energy consumption, leading to early fatigue and inducing non-physiological gait patterns. A new generation of KAFOs was developed to allow free knee flexion during the swing phase and to lock the knee joint during the stance phase to provide the required stability. These are commonly labeled as stance-control knee-ankle-foot orthoses (SCKAFOs). Nevertheless, commercial SCKAFOs are not available for the pediatric population. Especially in early ages, children must frequently replace the orthosis due to their growth. Hence, the proposed design presents a solution for a SCKAFO with adjustable length adaptable to children's dimensions ranging from two to six years old.

Pan-cancer association of a centrosome amplification gene expression signature with genomic alterations and clinical outcome.

Centrosome amplification (CA) is a common feature of human tumours and a promising target for cancer therapy. However, CA's pan-cancer prevalence, molecular role in tumourigenesis and therapeutic value in the clinical setting are still largely unexplored. Here, we used a transcriptomic signature (CA20) to characterise the landscape of CA-associated gene expression in 9,721 tumours from The Cancer Genome Atlas (TCGA). CA20 is upregulated in cancer and associated with distinct clinical and molecular features of breast cancer, consistently with our experimental CA quantification in patient samples. Moreover, we show that CA20 upregulation is positively associated with genomic instability, alteration of specific chromosomal arms and C>T mutations, and we propose novel molecular players associated with CA in cancer. Finally, high CA20 is associated with poor prognosis and, by integrating drug sensitivity with drug perturbation profiles in cell lines, we identify candidate compounds for selectively targeting cancer cells exhibiting transcriptomic evidence for CA.

A comparison study of the reporting systems for salivary gland fine needle aspirations: Are they really different?

BACKGROUND: Recently a new system for reporting salivary gland fine-needle aspiration (FNA) cytology was proposed, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). Herein, we evaluated diagnostic accuracy of salivary gland FNA, comparing the system previously used in our hospital with the Milan system. METHODS: Salivary gland specimens obtained between 2011 and 2017 were reclassified according to MSRSGC. Risk of malignancy for each diagnostic category was determined. Diagnostic yield of both classifications was evaluated. RESULTS: The cases (n = 388) were classified according to the old system: nondiagnostic (n = 28), benign (n = 246), atypical (n = 36), neoplastic (n = 57), suspicious for malignancy (n = 7) and malignant (n = 14). The lesions were distributed according to the MSRSGC: nondiagnostic (n = 28), non-neoplastic (n = 89), atypia of undetermined significance (n = 39), benign neoplasm (n = 156), neoplasm of uncertain malignant potential (n = 55), suspicious for malignancy (n = 7) and malignant (n = 14). When considering only benign and malignant cases, both classifications showed the same sensitivity (62.5%), specificity (100%) and similar accuracy (95.8%). Comparison between the two systems showed no significant difference. CONCLUSIONS: Salivary gland FNA has high diagnostic accuracy and assists clinical management independently of the reporting system used, however, in some cases, the use of Milan system could be beneficial, since it allows an enhanced category stratification.

Over-elongation of centrioles in cancer promotes centriole amplification and chromosome missegregation.

Centrosomes are the major microtubule organising centres of animal cells. Deregulation in their number occurs in cancer and was shown to trigger tumorigenesis in mice. However, the incidence, consequence and origins of this abnormality are poorly understood. Here, we screened the NCI-60 panel of human cancer cell lines to systematically analyse centriole number and structure. Our screen shows that centriole amplification is widespread in cancer cell lines and highly prevalent in aggressive breast carcinomas. Moreover, we identify another recurrent feature of cancer cells: centriole size deregulation. Further experiments demonstrate that severe centriole over-elongation can promote amplification through both centriole fragmentation and ectopic procentriole formation. Furthermore, we show that overly long centrioles form over-active centrosomes that nucleate more microtubules, a known cause of invasiveness, and perturb chromosome segregation. Our screen establishes centriole amplification and size deregulation as recurrent features of cancer cells and identifies novel causes and consequences of those abnormalities.

OXPHOS dysfunction regulates integrin-ß1 modifications and enhances cell motility and migration.

Mitochondria are central organelles for cellular metabolism. In cancer cells, mitochondrial oxidative phosphorylation (OXPHOS) dysfunction has been shown to promote migration, invasion, metastization and apoptosis resistance. With the purpose of analysing the effects of OXPHOS dysfunction in cancer cells and the molecular players involved, we generated cybrid cell lines harbouring either wild-type (WT) or mutant mitochondrial DNA (mtDNA) [tRNAmut cybrids, which harbour the pathogenic A3243T mutation in the leucine transfer RNA gene (tRNAleu)]. tRNAmut cybrids exhibited lower oxygen consumption and higher glucose consumption and lactate production than WT cybrids. tRNAmut cybrids displayed increased motility and migration capacities, which were associated with altered integrin-ß1 N-glycosylation, in particular with higher levels of ß-1,6-N-acetylglucosamine (GlcNAc) branched N-glycans. This integrin-ß1 N-glycosylation pattern was correlated with higher levels of membrane-bound integrin-ß1 and also with increased binding to fibronectin. When cultured in vitro, tRNAmut cybrids presented lower growth rate than WT cybrids, however, when injected in nude mice, tRNAmut cybrids produced larger tumours and showed higher metastatic potential than WT cybrids. We conclude that mtDNA-driven OXPHOS dysfunction correlates with increased motility and migration capacities, through a mechanism that may involve the cross talk between cancer cell mitochondria and the extracellular matrix.

High-throughput molecular profiling of a P-cadherin overexpressing breast cancer model reveals new targets for the anti-cancer bacterial protein azurin.

Azurin is a bacterial protein from Pseudomonas aeruginosa which exerts an inhibitory activity in cancer cells. In P-cadherin-overexpressing models, a bad prognosis marker in breast cancer increasing invasion and other malignant features, azurin decreases the invasion of cancer cells. We performed a microarray analysis to compare the expression profile of azurin treated cells with different P-cadherin expression levels. Azurin up-regulated apoptosis mediated by p53 protein, endocytosis and vesicle-mediated transport. In the contrary, in invasive MCF-7/AZ.Pcad cells, azurin decreased the expression of genes associated with cell surface receptors and signal transduction, as well as biological adhesion. Further, azurin decreased adhesion of cells to proteins from the extracellular matrix (ECM) and altered protein expression of integrins α6, ß4 and ß1 and interfered with the ability of these cells to form mammospheres. Altogether, our results further enlighten the anti-cancer effects mediated by azurin in P-cadherin overexpression breast cancer models.

Differential sensitivities to lactate transport inhibitors of breast cancer cell lines.

The tumour microenvironment is known to be acidic due to high glycolytic rates of tumour cells. Monocarboxylate transporters (MCTs) play a role in extracellular acidification, which is widely known to be involved in tumour progression. Recently, we have described the upregulation of MCT1 in breast carcinomas and its association with poor prognostic variables. Thus, we aimed to evaluate the effect of lactate transport inhibition in human breast cancer cell lines. The effects of α-cyano-4-hydroxycinnamate, quercetin and lonidamine on cell viability, metabolism, proliferation, apoptosis, migration and invasion were assessed in a panel of different breast cancer cell lines. MCT1, MCT4 and CD147 were differently expressed among the breast cancer cell lines and, as expected, different sensitivities were observed for the three inhibitors. Interestingly, in the most sensitive cell lines, lactate transport inhibition induced a decrease in cell proliferation, migration and invasion, as well as an increase in cell death. Results were validated by silencing MCT1 expression using siRNA. The results obtained here support targeting of lactate transport as a strategy to treat breast cancer, with a special emphasis on the basal-like subtype, which so far does not have a specific molecular therapy.