PDGFRα depletion attenuates glioblastoma stem cells features by modulation of STAT3, RB1 and multiple oncogenic signals.

Platelet derived growth factor receptors (PDGFRs) play an important role in tumor pathogenesis, and they are frequently overexpressed in glioblastoma (GBM). Earlier we have shown a higher protein expression of PDGFR isoforms (α and ß) in peritumoral-tissue derived cancer stem cells (p-CSC) than in tumor core (c-CSC) of several GBM affected patients. In the current study, in order to assess the activity of PDGFRα/PDGF-AA signaling axis, we performed time course experiments to monitor the effects of exogenous PDGF-AA on the expression of downstream target genes in c-CSC vs p-CSC. Interestingly, in p-CSC we detected the upregulation of Y705-phosphorylated Stat3, concurrent with a decrement of Rb1 protein in its active state, within minutes of PDGF-AA addition. This finding prompted us to elucidate the role of PDGFRα in self-renewal, invasion and differentiation in p-CSC by using short hairpin RNA depletion of PDGFRα expression. Notably, in PDGFRα-depleted cells, protein analysis revealed attenuation of stemness-related and glial markers expression, alongside early activation of the neuronal marker MAP2a/b that correlated with the induction of tumor suppressor Rb1. The in vitro reduction of the invasive capacity of PDGFRα-depleted CSC as compared to parental cells correlated with the downmodulation of markers of epithelial-mesenchymal transition phenotype and angiogenesis. Surprisingly, we observed the induction of anti-apoptotic proteins and compensatory oncogenic signals such as EDN1, EDNRB, PRKCB1, PDGF-C and PDGF-D. To conclude, we hypothesize that the newly discovered PDGFRα/Stat3/Rb1 regulatory axis might represent a potential therapeutic target for GBM treatment.

Metabolic Modification in Gastrointestinal Cancer Stem Cells: Characteristics and Therapeutic Approaches.

Currently, there is much interest in the characterization of metabolic profiling of cancer stem cells (CSCs), a small subset of tumor cells with self-renewal capacity. Indeed, ever-growing evidence indicate that metabolism and stemness are highly intertwined processes in tumor tissue. In this review, we analyze the potential metabolic targeting strategies for eradicating CSCs that could help to develop a more effective therapeutic approach for gastrointestinal cancers. Indeed, the successful elimination of a tumor requires an anticancer therapy that affects both cancer cells and CSCs. The observation that gastrointestinal CSCs possess higher inducible nitric oxide sinthase (iNOS) expression, lower reactive oxygen species (ROS) production, and a different metabolism respect to no-CSCs tumor cells has paved the way to develop drugs targeting CSC specific signaling. In particular, several studies have highlighted that metformin, aldehyde dehydrogenase 1, and iNOS inhibitors selectively suppressed CSC growth and that combinatorial therapy of them with standard chemotherapeutic drugs had a synergistic effect resulting in reduced tumor burden and delayed tumor recurrence. Thus, the possibility of combining specific CSC metabolism inhibitors with existing therapeutic approaches could have profound anticancer effects, changing the conventional treatment approaches to gastrointestinal cancers. J. Cell. Physiol. 231: 2081-2087, 2016. © 2016 Wiley Periodicals, Inc.

High nitric oxide production, secondary to inducible nitric oxide synthase expression, is essential for regulation of the tumour-initiating properties of colon cancer stem cells.

Chronic inflammation is a leading cause of neoplastic transformation in many human cancers and especially in colon cancer (CC), in part due to tumour promotion by nitric oxide (NO) generated at inflammatory sites. It has also been suggested that high NO synthesis, secondary to inducible NO synthase (iNOS) expression, is a distinctive feature of cancer stem cells (CSCs), a small subset of tumour cells with self-renewal capacity. In this study we explored the contribution of NO to the development of colon CSC features and evaluated potential strategies to treat CC by modulating NO production. Our data show an integral role for endogenous NO and iNOS activity in the biology of colon CSCs. Indeed, colon CSCs with high endogenous NO production (NO(high)) displayed higher tumourigenic abilities than NO(low) fractions. The blockade of endogenous NO availability, using either a specific iNOS inhibitor or a genetic knock-down of iNOS, resulted in a significant reduction of colon CSC tumourigenic capacities in vitro and in vivo. Interestingly, analysis of genes altered by iNOS-directed shRNA showed that the knockdown of iNOS expression was associated with a significant down-regulation of signalling pathways involved in stemness and tumour progression in colon CSCs. These findings confirm that endogenous NO plays an important role in defining the stemness properties of colon CSCs through cross-regulation of several cellular signalling pathways. This discovery could shed light on the mechanisms by which NO induces the growth and invasiveness of CC, providing new insights into the link between inflammation and colon tumourigenesis.

The multikinase inhibitor Sorafenib enhances glycolysis and synergizes with glycolysis blockade for cancer cell killing.

Although the only effective drug against primary hepatocarcinoma, the multikinase inhibitor Sorafenib (SFB) usually fails to eradicate liver cancer. Since SFB targets mitochondria, cell metabolic reprogramming may underlie intrinsic tumor resistance. To characterize cancer cell metabolic response to SFB, we measured oxygen consumption, generation of reactive oxygen species (ROS) and ATP content in rat LCSC (Liver Cancer Stem Cells) -2 cells exposed to the drug. Genome wide analysis of gene expression was performed by Affymetrix technology. SFB cytotoxicity was evaluated by multiple assays in the presence or absence of metabolic inhibitors, or in cells genetically depleted of mitochondria. We found that low concentrations (2.5-5 µM) of SFB had a relatively modest effect on LCSC-2 or 293 T cell growth, but damaged mitochondria and increased intracellular ROS. Gene expression profiling of SFB-treated cells was consistent with a shift toward aerobic glycolysis and, accordingly, SFB cytotoxicity was dramatically increased by glucose withdrawal or the glycolytic inhibitor 2-DG. Under metabolic stress, activation of the AMP dependent Protein Kinase (AMPK), but not ROS blockade, protected cells from death. We conclude that mitochondrial damage and ROS drive cell killing by SFB, while glycolytic cell reprogramming may represent a resistance strategy potentially targetable by combination therapies.

Lymphatic microsurgical preventing healing approach (LYMPHA) for primary surgical prevention of breast cancer-related lymphedema: over 4 years follow-up.

Breast cancer-related lymphedema (LE) represents an important morbidity that jeopardizes breast cancer patients' quality of life. Different attempts to prevent LE brought about improvements in the incidence of the pathology but LE still represents a frequent occurrence in breast cancer survivors. Over 4 years ago, Lymphatic Microsurgical Preventing Healing Approach (LYMPHA) was proposed and long-term results are reported in this study. From July 2008 to December 2012, 74 patients underwent axillary nodal dissection for breast cancer treatment together with LYMPHA procedure. Volumetry was performed preoperatively in all patients and after 1, 3, 6, 12 months, and once a year. Lymphoscintigraphy was performed in 45 patients preoperatively and in 30 also postoperatively after at least over 1 year. Seventy one patients had no sign of LE, and volumetry was coincident to preoperative condition. In three patients, LE occurred after 8-12 months postoperatively. Lymphoscintigraphy showed the patency of lymphatic-venous anastomoses at 1-4 years after operation. LYMPHA technique represents a successful surgical procedure for primary prevention of arm LE in breast cancer patients.

Tumor initiating cells and chemoresistance: which is the best strategy to target colon cancer stem cells?

There is an emerging body of evidence that chemoresistance and minimal residual disease result from selective resistance of a cell subpopulation from the original tumor that is molecularly and phenotypically distinct. These cells are called "cancer stem cells" (CSCs). In this review, we analyze the potential targeting strategies for eradicating CSCs specifically in order to develop more effective therapeutic strategies for metastatic colon cancer. These include induction of terminal epithelial differentiation of CSCs or targeting some genes expressed only in CSCs and involved in self-renewal and chemoresistance. Ideal targets could be cell regulators that simultaneously control the stemness and the resistance of CSCs. Another important aspect of cancer biology, which can also be harnessed to create novel broad-spectrum anticancer agents, is the Warburg effect, also known as aerobic glycolysis. Actually, little is yet known with regard to the metabolism of CSCs population, leaving an exciting unstudied avenue in the dawn of the emerging field of metabolomics.

Colon cancer stem cells: controversies and perspectives.

Tumors have long been viewed as a population in which all cells have the equal propensity to form new tumors, the so called conventional stochastic model. The cutting-edge theory on tumor origin and progression, tends to consider cancer as a stem cell disease. Stem cells are actively involved in the onset and maintenance of colon cancer. This review is intended to examine the state of the art on colon cancer stem cells (CSCs), with regard to the recent achievements of basic research and to the corresponding translational consequences. Specific prominence is given to the hypothesized origin of CSCs and to the methods for their identification. The growing understanding of CSC biology is driving the optimization of novel anti-cancer targeted drugs.

Identification of Endothelin-1 and NR4A2 as CD133-regulated genes in colon cancer cells.

Several in vitro assays have been proposed to identify cancer stem cells (CSCs), including immunophenotyping, sphere assay and side population (SP) assay. CD133 antigen has been proposed as a CSC marker in colon cancer (CC). However, no functional data are available to date and conflicting results have been reported regarding its role as true CSC marker. Here we set out to identify a molecular signature associated with potential CSC. CD133(+) cells isolated from the CaCo-2 CC cell line were analysed by microarray molecular profiling compared to CD133(-) counterparts. Various differentially expressed genes were identified and the most relevant transcripts found to be over-expressed in CD133(+) cells were evaluated by quantitative RT-PCR in the CD133(+) fractions isolated from several CC cell lines. In the attempt to find a correlation between putative CSCs, isolated by means of CD133 immunophenotyping and the SP approach, we demonstrated a significant enrichment of CD133(+) cells within the SP fraction of CC cells, and comparison of the gene expression profiles revealed that Endothelin-1 (END-1) and nuclear receptor subfamily 4, group A, member 2 (NR4A2) transcripts are highly expressed in both CD133(+) and SP fractions of CC cells. Moreover, depletion of CD133 by siRNA induced a significant attenuation of END-1 and NR4A2 expression levels in CaCo-2 cells, while expression of all three molecules decreased during sodium butyrate-induced differentiation. In conclusion, we have identified a molecular signature associated with potential CSCs and showed for the first time the existence of a functional relationship between CD133, END-1 and NR4A2 expression in colon cancer cells.

Surgical prevention of arm lymphedema after breast cancer treatment.

PURPOSE: To prospectively assess the efficacy of the lymphatic microsurgical preventive healing approach (LYMPHA) to prevent lymphedema after axillary dissection (AD) for breast cancer treatment. METHODS: Among 49 consecutive women referred from March 2008 to September 2009 to undergo complete AD, 46 were randomly divided in 2 groups. Twenty-three underwent the LYMPHA technique for the prevention of arm lymphedema. The other 23 patients had no preventive surgical approach (control group). The LYMPHA procedure consisted of performing lymphatic-venous anastomoses (LVA) at the time of AD. All patients underwent preoperative lymphoscintigraphy (LS). Patients were followed up clinically at 1, 3, 6, 12, and 18 months by volumetry. Postoperatively, LS was performed after 18 months in 41 patients (21 treatment group and 20 control group). Arm volume and LS alterations were assessed. RESULTS: Lymphedema appeared in 1 patient in the treatment group 6 months after surgery (4.34%). In the control group, lymphedema occurred in 7 patients (30.43%). No statistically significant differences in the arm volume were observed in the treatment group during follow-up, while the arm volume in the control group showed a significant increase after 1, 3, and 6 months from operation. There was significant difference between the 2 groups in the volume changes with respect to baseline after 1, 3, 6, 12, and 18 months after surgery (every timing P value < 0.01). CONCLUSIONS: LYMPHA represents a valid technique for primary prevention of secondary arm lymphedema with no risk of leaving undetected malignant disease in the axilla.

Gene profiling of bone marrow- and adipose tissue-derived stromal cells: a key role of Kruppel-like factor 4 in cell fate regulation.

BACKGROUND AIMS: Bone marrow- and adipose tissue-derived mesenchymal stromal cells (MSC) represent promising sources for regenerative medicine. However, the precise molecular mechanisms underlying MSC stemness maintenance versus differentiation are not fully understood. The aim of this study was to compare the genome-wide expression profiles of bone marrow-and adipose tissue-derived MSC, in order to identify a common molecular stemness core. METHODS: Molecular profiling was carried out using Affymetrix microarray and relevant genes were further validated by Q-PCR. RESULTS: We identified an overlapping dataset of 190 transcripts commonly regulated in both cell populations, which included several genes involved in stemness regulation (i.e. self-renewal potential and the ability to generate differentiated cells), various signaling pathways and transcription factors. In particular, we identified a central role of the Kruppel-like factor 4 (KLF4) DNA-binding protein in regulating MSC transcriptional activity. CONCLUSIONS: Our results provide new insights toward understanding the molecular basis of MSC stemness maintenance and underline the ability of KLF4 to maintain cells in an undifferentiated state.

Neurotrophic features of human adipose tissue-derived stromal cells: in vitro and in vivo studies.

Due to its abundance, easy retrieval, and plasticity characteristics, adipose-tissue-derived stromal cells (ATSCs) present unquestionable advantages over other adult-tissue-derived stem cells. Based on the in silico analysis of our previous data reporting the ATSC-specific expression profiles, the present study attempted to clarify and validate at the functional level the expression of the neurospecific genes expressed by ATSC both in vitro and in vivo. This allowed evidencing that ATSCs express neuro-specific trophins, metabolic genes, and neuroprotective molecules. They were in fact able to induce neurite outgrowth in vitro, along with tissue-specific commitment along the neural lineage and the expression of the TRKA neurotrophin receptor in vivo. Our observation adds useful information to recent evidence proposing these cells as a suitable tool for cell-based applications in neuroregenerative medicine.

Therapeutic implications of mesenchymal stem cells in liver injury.

Mesenchymal stem cells (MSCs), represent an attractive tool for the establishment of a successful stem-cell-based therapy of liver diseases. A number of different mechanisms contribute to the therapeutic effects exerted by MSCs, since these cells can differentiate into functional hepatic cells and can also produce a series of growth factors and cytokines able to suppress inflammatory responses, reduce hepatocyte apoptosis, regress liver fibrosis, and enhance hepatocyte functionality. To date, the infusion of MSCs or MSC-conditioned medium has shown encouraging results in the treatment of fulminant hepatic failure and in end-stage liver disease in experimental settings. However, some issues under debate hamper the use of MSCs in clinical trials. This paper summarizes the biological relevance of MSCs and the potential benefits and risks that can result from translating the MSC research to the treatment of liver diseases.

Anal metastasis from recurrent breast lobular carcinoma: a case report.

We report a case of isolated gastrointestinal metastasis from breast lobular carcinoma, which mimicked primary anal cancer. In July 2000, an 88-year-old woman presented with infiltrating lobular cancer (pT1/G2/N2). The patient received postoperative radiotherapy and hormonal therapy. Four years later, she presented with an anal polypoid lesion. The mass was removed for biopsy. Immunohistochemical staining suggested a breast origin. Radiotherapy was chosen for this patient, which resulted in complete regression of the lesion. The patient died 3 years after the first manifestation of gastrointestinal metastasis. According to the current literature, we consider the immunohistochemistry features that are essential to support the suspicion of gastrointestinal breast metastasis, and since we consider the gastrointestinal involvement as a sign of systemic disease, the therapy should be less aggressive and systemic.

Rectal hepatoid carcinoma with liver metastases in a patient affected by ulcerative colitis.

BACKGROUND: Hepatoid tumors (HTs) are rare extra-hepatic neoplasms with the histological features, biochemical profile and, sometimes, even clinical course of hepatocellular carcinoma. We present a case of rectal hepatoid adenocarcinoma with metachronous liver metastases. METHODS: Four months after total procto-colectomy for a rectal adenocarcinoma (Astler-Coller C2), a 42-year-old man with ulcerative colitis showed hypoechoic masses in the hepatic parenchyma by abdominal ultrasonography. Carcinoembryonic antigen was normal, but alpha-fetoprotein was 32,000 microg/L. Fine-needle biopsy revealed that liver masses were positive for hepatocellular carcinoma. The patient underwent left hepatectomy and alcoholisation of a small deep nodule in segment 8. RESULTS: Immunohistochemistry and albumin mRNA in situ hybridization suggested that the nodules were metastases of a HT. The patient was well during the first 6 months and refused any adjuvant chemotherapy. He died from liver failure 19 months after initial diagnosis. CONCLUSIONS: HT is a rare colon cancer. The preoperative diagnosis of this tumor requires a high degree of suspicion, the availability of a panel of immunohistochemical markers, and a certain amount of luck. The prognosis is poor despite an aggressive and multimodal therapeutic strategy. So far, none of the hypotheses proposed about the origin and the biology of these tumors is convincing.

Identification of an adult stem/progenitor cell-like population in the human thyroid.

There is evidence that tissue-specific stem cells reside in certain adult tissues. Their specific properties remain elusive, because they are rare and heterogeneous in parent tissues; furthermore, technical difficulties have been encountered in the identification and characterization of their progeny. The aim of this study was to isolate stem/progenitor cells from the human thyroid. We devised a method based on the enzymatic digestion of fresh surgical thyroid specimens, followed by culture of cells in the presence of epidermal growth factor and basic fibroblast growth factor. We also used markers that identify and characterize these cells. Spheroids with self-replicative potential were obtained from all thyroid specimens. The isolated population contained a subset of CD34+ CD45- cells and it was able, in differentiation conditions, to generate follicles with thyroid hormonal production. In support of the plasticity concept, we obtained evidence that, when most freshly isolated spheroids were co-cultured with a neuroblastoma cell line, they produced progeny expressing the neuronal marker beta-tubulin III. Spheroids were also able to undergo adipogenic differentiation when cultured in adipogenic medium. We conclude that a predominant functional type of stem/progenitor cell exists within the thyroid, with an intrinsic ability to generate thyroidal cells and the potential to produce non-thyroidal cells.

Gastrointestinal stromal tumors: clinical pathological review of a personal series.

The Authors report their experience on the management of gastrointestinal stromal tumors (GISTs). In addition to recent cases immediately diagnosed as GISTs, a pathological review of stored material from non-epithelial tumors of the gastrointestinal tract operated on over the past 20 years was performed. Twenty-three out of a total of 31 cases were shown to be positive for the immunophenotypic characteristics (CD117/CD34) of GISTs. Most cases (approximately 60%) were symptomatic, with hemorrhage being the most common presenting sign, followed by occlusion, pain and perforation. Asymptomatic cases were detected incidentally during procedures for other conditions. Diagnostic techniques (ultrasound, endoscopy, endoscopic ultrasound, X-ray, CT, MRI) allowed only the detection of wall (extraluminal) involvement. Apart from differentiating between benign and malignant, preoperative biopsy was seldom valuable. All cases were treated surgically, with intervention tailored to location and anatomical/surgical and anatomical/pathological features. Long-term follow-up was conducted in all patients and for most is still ongoing: five patients died from recurrent disease at varying intervals after surgery (from 17 to 102 months). Relationships between observed aggressiveness and risk were studied. Parameters that may prove useful for the early detection and appropriate management of these lesions are discussed.

[Inguinal hernia recurrence. Report of our personal experience]. / La recidiva erniaria. Osservazioni su casistica personale.

In our previous studies, we reasserted the concept regarding the fundamental role of the transversalis fascia in securing and maintaining restraint on the abdominal wall in correspondence with the "inguinal fissure", which is considered a hiatus and a weak point. The role played by the transversalis fascia was first proposed by Edoardo Bassini and later reaffirmed by other authors, surgeons and anatomists. This concept led to the belief that the procedures deemed effective in treating inguinal hernia were those capable of strengthening or substituting the transversalis fascia. In a recent study we compared the immediate and long-term results of three techniques: Bassini, Lichtenstein and preperitoneal prosthesis by inguinal way. A lower number of recurrences was noted in the latter as compared to the others. Based on the aforementioned points, the same verification was carried out regarding recurrent inguinal hernia. The results concerning the incidence of relapse were similar, proving once again the effectiveness of the preperitoneal prosthesis (2.5% vs 6.6% for Lichtenstein). We have also attempted to identify the factors which were considered possible causes of recurrence in the previous cases we examined, allowing us to reach useful conclusions in the prevention of hernia recurrence.