Tumor-activated mesenchymal stromal cells promote osteosarcoma stemness and migratory potential via IL-6 secretion

Osteosarcoma (OS) is an aggressive bone malignancy with a high relapse rate despite combined treatment with surgery and multiagent chemotherapy. As for other cancers, OS-associated microenvironment may contribute to tumor initiation, growth, and metastasis. We consider mesenchymal stromal cells (MSC) as a relevant cellular component of OS microenvironment, and have previously found that the interaction between MSC and tumor cells is bidirectional: tumor cells can modulate their peripheral environment that in turn becomes more favorable to tumor growth through metabolic reprogramming. Here, we determined the effects of MSC on OS stemness and migration, two major features associated with recurrence and chemoresistance. The presence of stromal cells enhanced the number of floating spheres enriched in cancer stem cells (CSC) of the OS cell population. Furthermore, the co-culturing with MSC stimulated the migratory capacity of OS via TGF\u3b21 and IL-6 secretion, and the neutralizing antibody anti-IL-6 impaired this effect. Thus, stromal cells in combination with OS spheres exploit a vicious cycle where the presence of CSC stimulates mesenchymal cytokine secretion, which in turn increases stemness, proliferation, migration, and metastatic potential of CSC, also through the increase of expression of adhesion molecules like ICAM-1. Altogether, our data corroborate the concept that a comprehensive knowledge of the interplay between tumor and stroma that also includes the stem-like fraction of tumor cells is needed to develop novel and effective anti-cancer therapies

Association study between the DNMT3A -448A>G polymorphism and risk of Alzheimer's disease in Caucasians of Italian origin

Increasing evidence points to an epigenetic contribution in Alzheimer's disease (AD) pathogenesis. In this regard, variants and polymorphisms of DNA methyltransferase genes (DNMTs) are being investigated for their contribution to cognitive decline and dementia, but results are still scarce or controversial. In the present study we genotyped 710 Caucasian subjects of Italian descent, including 320 late-onset AD (LOAD) patients, 70 individuals with amnestic Mild Cognitive Impairment (MCI), and 320 matched healthy controls, for the presence of a functional DNMT3A -448A>G (rs1550117) polymorphism, searching for association with disease risk. In addition, we searched for correlation between the studied polymorphism and circulating levels of folate, homocysteine (hcy) and vitamin B12, all involved in DNA methylation reactions and available from 189 LOAD patients and 186 matched controls. Both allele and genotype frequencies of rs1550117 were closely similar between MCI, LOAD and control subjects, and no association with dementia or pre-dementia conditions was observed. Plasma hcy levels were significantly higher (p = 0.04) and serum folate levels significantly lower (p = 0.01) in LOAD than in controls, but no difference in circulating folate, hcy or vitamin B12 levels was seen between carriers and non-carriers of the minor DNMT3A -448A allele. Collectively, present results confirmed previous associations of increased hcy and decreased folate with LOAD risk, but do not support an association between the DNMT3A -448A>G polymorphism and AD in our population

The effect of four mutations on the expression of iduronate-2-sulfatase in mucopolysaccharidosis type II

AbstractMucopolysaccharidosis type II (Hunter syndrome; OMIM 309900) is a rare X-linked recessive lysosomal storage disorder caused by the deficiency of the enzyme iduronate-2-sulfatase (IDS; EC 3.1.6.13). Different alterations at the IDS locus, mostly missense mutations, have been demonstrated, by expression study, as deleterious, causing significant consequences on the enzyme function or stability. In the present study we report on the results of the transient expression of the novel K347T, 533delTT, N265I and the already described 473delTCC (previously named ΔS117) mutations in the COS 7 cells proving their functional consequence on IDS activity. This type of information is potentially useful for genotype–phenotype correlation, prognosis and possible therapeutic intervention

Role of mesenchymal stem cells in osteosarcoma and metabolic reprogramming of tumor cells

The tumor microenvironment plays an important role in cancer progression. Here, we focused on the role of reactive mesenchymal stem cells (MSC) in osteosarcoma (OS), and used human adipose MSC and a panel of OS cell lines (Saos-2, HOS, and 143B) to investigate the mutual effect of normal-cancer cell metabolic programming. Our results showed that MSC are driven by oxidative stress induced by OS cells to undergo Warburg metabolism, with increased lactate production. Therefore, we analyzed the expression of lactate monocarboxylate transporters. By real time PCR and immunofluorescence, in MSC we detected the expression of MCT-4, the transporter for lactate efflux, whereas MCT-1, responsible for lactate uptake, was expressed in OS cells. In agreement, silencing of MCT-1 by siRNA significantly affected the ATP production in OS cancer cells. Thus, cancer cells directly increase their mitochondrial biogenesis using this energy-rich metabolite that is abundantly provided by MSC as an effect of the altered microenvironmental conditions induced by OS cells. We also showed that lactate produced by MSC promotes the migratory ability of OS cells. These data provide novel information to be exploited for cancer therapies targeting the mutual metabolic reprogramming of cancer cells and their stroma.The tumor microenvironment plays an important role in cancer progression. Here, we focused on the role of reactive mesenchymal stem cells (MSC) in osteosarcoma (OS), and used human adipose MSC and a panel of OS cell lines (Saos-2, HOS, and 143B) to investigate the mutual effect of normal-cancer cell metabolic programming. Our results showed that MSC are driven by oxidative stress induced by OS cells to undergo Warburg metabolism, with increased lactate production. Therefore, we analyzed the expression of lactate monocarboxylate transporters. By real time PCR and immunofluorescence, in MSC we detected the expression of MCT-4, the transporter for lactate efflux, whereas MCT-1, responsible for lactate uptake, was expressed in OS cells. In agreement, silencing of MCT-1 by siRNA significantly affected the ATP production in OS cancer cells. Thus, cancer cells directly increase their mitochondrial biogenesis using this energy-rich metabolite that is abundantly provided by MSC as an effect of the altered microenvironmental conditions induced by OS cells. We also showed that lactate produced by MSC promotes the migratory ability of OS cells. These data provide novel information to be exploited for cancer therapies targeting the mutual metabolic reprogramming of cancer cells and their stroma

Cav1 Suppresses Tumor Growth and Metastasis in a Murine Model of Cutaneous SCC through Modulation of MAPK/AP-1 Activation

Caveolin-1 (Cav1) is a scaffolding protein that serves to regulate the activity of several signaling molecules. Its loss has been implicated in the pathogenesis of several types of cancer, but its role in the development and progression of cutaneous squamous cell carcinoma (cSCC) remains largely unexplored. Herein, we use the keratinocyte cell line PAM212, a murine model of cSCC, to determine the function of Cav1 in skin tumor biology. We first show that Cav1 overexpression decreases cell and tumor growth, whereas Cav1 knockdown increases these attributes in PAM212 cells. In addition, Cav1 knockdown increases the invasive ability and incidence of spontaneous lymph node metastasis. Finally, we demonstrate that Cav1 knockdown increases extracellular signaling–related kinase 1/2 mitogen-activated protein kinase/activator protein-1 pathway activation. We attribute the growth and invasive advantage conferred by Cav1 knockdown to increased expression of activator protein-1 transcriptional targets, including cyclin D1 and keratin 18, which show inverse expression in PAM212 based on the expression level of Cav1. In summary, we demonstrate that loss of Cav1 affects several characteristics associated with aggressive human skin tumors and that this protein may be an important modulator of tumor growth and invasion in cSCC

A mitochondrial based oncology platform for targeting cancer stem cells (CSCs) : MITO-ONC-RX

Here, we wish to propose a new systematic approach to cancer therapy, based on the targeting of mitochondrial metabolism, especially in cancer stem cells (CSCs). In the future, we envision that anti-mitochondrial therapy would ultimately be practiced as an add-on to more conventional therapy, largely for the prevention of tumor recurrence and cancer metastasis. This mitochondrial based oncology platform would require a panel of FDA-approved therapeutics (e.g. Doxycycline) that can safely be used to inhibit mitochondrial OXPHOS and/or biogenesis in CSCs. In addition, new therapeutics that target mitochondria could also be developed, to optimize their ability to eradicate CSCs. Finally, in this context, mitochondrial-based biomarkers (i.e. “Mito-signatures”) could be utilized as companion diagnostics, to identify high-risk cancer patients at diagnosis, facilitating the early detection of tumor recurrence and the prevention of treatment failure. In summary, we suggest that new clinical trials are warranted to test and possibly implement this emerging treatment strategy, in a variety of human cancer types. This general approach, using FDA-approved antibiotics to target mitochondria, was effective in killing CSCs originating from many different cancer types, including DCIS, breast (ER(+) and ER(-)), prostate, ovarian, lung and pancreatic cancers, as well as melanoma and glioblastoma, among others. Thus, we propose the term MITO-ONC-RX, to describe this anti-mitochondrial platform for targeting CSCs. The use of re-purposed FDA-approved drugs will undoubtedly help to accelerate the clinical evaluation of this approach, as these drugs can move directly into Phase II clinical trials, saving considerable amounts of time (10–15 y) and billions in financial resources

CAV1 inhibits metastatic potential in melanomas through suppression of the Integrin/Src/FAK signaling pathway.

Caveolin-1 (CAV1) is the main structural component of Caveolae which are plasma membrane invaginations that participate in vesicular trafficking and signal transduction events. Although, evidence has recently accumulated describing the function of CAV1 in several cancer types, its role in melanoma tumor formation and progression remains poorly explored. Here, by employing B16F10 melanoma cells as an experimental system, we directly explore the function of CAV1 in melanoma tumor growth and metastasis. We first show that CAV1 expression promotes proliferation while it suppresses migration and invasion of B16F10 cells in vitro. When orthotopically implanted in the skin of mice, B16F10 cells expressing CAV1 form tumors that are similar in size to their control counterpart. An experimental metastasis assay demonstrates that CAV1 expression suppresses the ability of B16F10 cells to form lung metastases in C57Bl/6 syngeneic mice. Additionally, CAV1 protein and mRNA levels are found to be significantly reduced in human metastatic melanoma cell lines and human tissue from metastatic lesions. Finally, we demonstrate that following integrin activation, B16F10 cells expressing CAV1 display reduced expression levels and activity of FAK and Src proteins. CAV1 expression also markedly reduces the expression levels of beta3 Integrin in B16F10 melanoma cells. In summary, our findings provide experimental evidence that CAV1 may function as an antimetastatic gene in malignant melanoma

Metabolic remodeling of the tumor microenvironment: migration stimulating factor (MSF) reprograms myofibroblasts toward lactate production, fueling anabolic tumor growth.

Migration stimulating factor (MSF) is a genetically truncated N-terminal isoform of fibronectin that is highly expressed during mammalian development in fetal fibroblasts, and during tumor formation in human cancer-associated myofibroblasts. However, its potential functional role in regulating tumor metabolism remains unexplored. Here, we generated an immortalized fibroblast cell line that recombinantly overexpresses MSF and studied their properties relative to vector-alone control fibroblasts. Our results indicate that overexpression of MSF is sufficient to confer myofibroblastic differentiation, likely via increased TGF-b signaling. In addition, MSF activates the inflammation-associated transcription factor NFκB, resulting in the onset of autophagy/mitophagy, thereby driving glycolytic metabolism (L-lactate production) in the tumor microenvironment. Consistent with the idea that glycolytic fibroblasts fuel tumor growth (via L-lactate, a high-energy mitochondrial fuel), MSF fibroblasts significantly increased tumor growth, by up to 4-fold. Mechanistic dissection of the MSF signaling pathway indicated that Cdc42 lies downstream of MSF and fibroblast activation. In accordance with this notion, Cdc42 overexpression in immortalized fibroblasts was sufficient to drive myofibroblast differentiation, to provoke a shift towards glycolytic metabolism and to promote tumor growth by up to 2-fold. In conclusion, the MSF/Cdc42/NFκB signaling cascade may be a critical druggable target in preventing Warburg-like cancer metabolism in tumor-associated fibroblasts. Thus, MSF functions in the metabolic remodeling of the tumor microenvironment by metabolically reprogramming cancer-associated fibroblasts toward glycolytic metabolism

Alexithymia may modulate decision making in patients with de novo Parkinson’s disease

The aim of this study was to investigate whether and how alexithymia may influence decision making under conditions of uncertainty, assessed using the Iowa Gambling Task, in patients with newly diagnosed, untreated (de novo) Parkinson’s disease, as previously reported for healthy subjects. Twenty-four patients with de novo Parkinson’s disease underwent a neuropsychological and neuropsychiatric assessment, including the Toronto Alexithymia Scale, the Geriatric Depression Scale Short Form, and the Iowa Gambling Task (IGT). The assessment showed that 12 patients were alexithymic and 12 were non-alexithymic; seven patients were found to be mildly depressed and 17 non-depressed. Alexithymic and non-alexithymic patients did not differ in the IGT total score; however, significant differences emerged across the third block of the IGT, in which the alexithymic patients outperformed the nonalexithymic patients. Depression did not influence IGT performance. Alexithymia may modulate decision making, as assessed with the IGT; alexithymia could be associated with faster learning to avoid risky choices and negative feedback, as previously reported in some studies conducted in anxious or depressed patients