A phase I pharmacokinetic study of hypoxic abdominal stop-flow perfusion with gemcitabine in patients with advanced pancreatic cancer and refractory malignant ascites

PURPOSE: As no curative treatment for advanced pancreatic and biliary cancer with malignant ascites exists, new modalities possibly improving the response to available chemotherapies must be explored. This phase I study assesses the feasibility, tolerability and pharmacokinetics of a regional treatment of gemcitabine administered in escalating doses by the stop-flow approach to patients with advanced abdominal malignancies (adenocarcinoma of the pancreas, n = 8, and cholangiocarcinoma of the liver, n = 1). EXPERIMENTAL DESIGN: Gemcitabine at 500, 750 and 1,125 mg/m(2) was administered to three patients at each dose level by loco-regional chemotherapy, using hypoxic abdominal stop-flow perfusion. This was achieved by an aorto-caval occlusion by balloon catheters connected to an extracorporeal circuit. Gemcitabine and its main metabolite 2',2'-difluorodeoxyuridine (dFdU) concentrations were measured by high performance liquid chromatography with UV detection in the extracorporeal circuit during the 20 min of stop-flow perfusion, and in peripheral plasma for 420 min. Blood gases were monitored during the stop-flow perfusion and hypoxia was considered stringent if two of the following endpoints were met: pH </= 7.2, pO(2) nadir ratio </=0.70 or pCO(2) peak ratio >/=1.35. The tolerability of this procedure was also assessed. RESULTS: Stringent hypoxia was achieved in four patients. Very high levels of gemcitabine were rapidly reached in the extracorporeal circuit during the 20 min of stop-flow perfusion, with C (max) levels in the abdominal circuit of 246 (+/-37%), 2,039 (+/-77%) and 4,780 (+/-7.3%) mug/ml for the three dose levels 500, 750 and 1,125 mg/m(2), respectively. These C (max) were between 13 (+/-51%) and 290 (+/-12%) times higher than those measured in the peripheral plasma. Similarly, the abdominal exposure to gemcitabine, calculated as AUC(t0-20), was between 5.5 (+/-43%) and 200 (+/-66%)-fold higher than the systemic exposure. Loco-regional exposure to gemcitabine was statistically higher in presence of stringent hypoxia (P < 0.01 for C (max) and AUC(t0-20), both normalised to the gemcitabine dose). Toxicities were acceptable considering the complexity of the procedure and were mostly hepatic; it was not possible to differentiate the respective contributions of systemic and regional exposures. A significant correlation (P < 0.05) was found between systemic C (max) of gemcitabine and the nadir of both leucocytes and neutrophils. CONCLUSIONS: Regional exposure to gemcitabine-the current standard drug for advanced adenocarcinoma of the pancreas-can be markedly enhanced using an optimised hypoxic stop-flow perfusion technique, with acceptable toxicities up to a dose of 1,125 mg/m(2). However, the activity of gemcitabine under hypoxic conditions is not as firmly established as that of other drugs such as mitomycin C, melphalan or tirapazamine. Further studies of this investigational modality, but with bioreductive drugs, are therefore warranted first to evaluate the tolerance in a phase I study and later on to assess whether it does improve the response to chemotherapy.

Intraoperative photodynamic therapy of the chest cavity in malignant pleural mesothelioma bearing rats.

BACKGROUND AND OBJECTIVE: Experimental assessment of anticancer effect, normal tissue damage, and toxicity of intrathoracic mTHPC-mediated photodynamic therapy (PDT) combined to surgery in malignant pleural mesothelioma (MPM) bearing rats. STUDY DESIGN/MATERIALS AND METHODS: Six days after implantation of syngenic malignant mesothelioma cells in the left chest cavity of Fischer rats (n = 21) and 4 days after sensitization (0.1 mg/kg mTHPC), a left-sided pneumonectomy was performed, followed by intraoperative light delivery (652 nm, fluence 20 J/cm(2)), either by spherical illumination of the chest cavity (fluence rate 15 mW/cm(2)) or by focal illumination of a tumor area (fluence rate 150 mW/cm(2)). Controls comprised tumor-bearing untreated animals, tumor-bearing animals undergoing pneumonectomy, and tumor-bearing animals undergoing pneumonectomy and light delivery without sensitization or sensitization without light delivery. No thoracocentesis was performed during follow-up. RESULTS: An invasively growing sarcomatous type of mesothelioma was found in all animals at day 10, without tumor necrosis in control animals. PDT resulted in 0.5-1 mm deep inhomogeneous tumor necrosis after spherical, and in a 1-2 mm deep tumor necrosis after focal illumination. No injury to mediastinal organs was observed, neither after PDT with spherical nor with focal light delivery except focal interstitial lung fibrosis at the mediastinal area of the opposite lung. All animals with pneumonectomy followed by spherical PDT of the entire tumor-bearing chest cavity died within 72 hours whereas all other animals survived. All animals that died presented massive pleural effusion. CONCLUSIONS: PDT following pneumonectomy in mesothelioma bearing rats was technically feasible and allowed to study its effect on tumor and normal tissues. PDT-related tumor necrosis was observed after spherical and focal light delivery, however, pneumonectomy followed by PDT with spherical light delivery to the tumor-bearing chest cavity resulted in fatal complications.

Dysregulated activation of the CXCR4/CXCL12 Axisand its role in the malignant phenotype of neural crest-derived neuroblastoma tumours

Résumé: Le neuroblastome (NB) est un néoplasme dévastateur de la petite enfance, pour lequel il n'existe pas encore de traitement efficace. Les chimiokines et leurs récepteurs ont été impliqués dans la croissance des tumeurs et la formation de métastases, et en particulier, il a été rapporté que l'axe CXCR4/CXCL12 dirigeait le guidage, ainsi que l'invasion des cellules cancéreuses vers des organes spécifiques. Notre étude avait pour objectif d'analyser le rôle de CxCR4 exogène dans le comportement malin du NB, en étudiant la croissance des cellules tumorales, leur capacité de survie, de migration et d'invasion in vitro et en validant ces résultats grâce à un modèle orthotopique murin de la progression tumorale du NB in vivo. La surexpression de CXCR4 dans les cellules faiblement métastatiques IGR-NB8 n'exprimant pas CXCR4, a augmenté la mobilité des cellules vers CXCL12 in vitro. De plus, les cellules surexprimant CXCR4 ont été moins affectées par la privation de sérum que les cellules contrôles. Le volume des tumeurs chez les animaux greffés de manière orthotopique avec les cellules NB8-CXCR4-C3 était significativement plus élevé que celui des tumeurs issues des cellules contrôles NB8-E6 au moment du sacrifice des animaux. Cependant, aucune induction des métastases n'a été observée. La lignée cellulaire IGR-N91, aux propriétés invasives et métastatiques in vivo, exprime constitutivement des quantités modérées de CXCR4. La surexpression du récepteur dans cette lignée a accéléré la croissance tumorale in vivo, mais n'a pas augmenté pas l'occurrence des métastases. Les cellules IGR-N91, dans lesquelles l'expression de CXCR4 a été éteinte, suite à l'introduction de shRNA stable contre CXCR4, a présenté une croissance cellulaire plus lente, in vitro et in vivo. Afin d'identifier les gènes et les voies de signalisation impliqués dans les effets dépendants de CXCR4-CXCL12 dans le NB, des analyses du profil d'expression des gènes ont été effectuées sur les lignées cellulaires transfectées ou non (contrôle). Trois clones contrôles ont été comparés à 3 clones surexprimant CXCR4 pour chacune des lignées (IGR-NB8 et IGR-N91). Les analyses biostatiques ont identifié 10 gènes induits, dont CXCR4, et 31 gènes réprimés, communs entre tous les clones surexprimant CXCR4. Ces observations démontrent que la surexpression de CXCR4 dans le NB stimule la croissance, la survie et la migration chémotactique des cellules tumorales, mais est insuffisante pour induire ou augmenter leurs capacités invasives et métastatiques. Les voies de signalisation activées suite à la surexpression de CXCR4 et identifiées à travers le profil global de l'expression des gènes pourraient être des cibles intéressantes pour le développement de drogues capables d'inhiber la croissance tumorale. Abstact: Neuroblastoma (NB) is a devastating childhood neoplasm for which there is not yet an efficient treatment. Chemokines and their receptors have been involved in tumour growth and metastasis, and in particular the CXCR4/CXCL12 axis has been reported to mediate organ-specific cancer cells homing and invasion. The purpose of the study was to investigate the role of ectopic CXCR4 in the malignant behaviour of NB by studying tumour cell growth, survival, migration, and invasion in vitro and by validating these results using a murine orthotopic model of NB tumour progression in vivo. CXCR4 overexpression in the low metastatic, CXCR4-negative IGR-NB8 cells resulted in CXCL12-mediated chemotaxis in vitro. Furthermore, CXCR4 overexpressing cells were less affected by serum deprivation than mock-transduced cells. In vivo studies revealed that, at sacrifice, volumes of tumours developing in mice with orthotopically implanted NB8-CXCR4-C3 cells, were significantly increased compared to NB8-E6 control tumours. However, no induction of metastases was observed. The in vivo invasive and metastatic cell line IGR-N91 cell line constitutively expresses moderate levels of CXCR4. Overexpression of CXCR4 enhanced in vivo tumour growth but did not increase the occurrence of metastases. IGR-N91 cells where CXCR4 has been knocked-down by stable shRNA grew slower in vitro and in vivo. To identify genes and pathways involved in the CXCR4/CXCL12-mediated effects in NB expression, profiles analyses (Affymetrix) were performed on transduced and control cell lines. Three mock-transduced clones were compared to three CXCR4 overexpressing clones of either cell line IGR-NB8 and IGR-N91. Biostatistical analysis identified 10 commonly upregulated genes (including CXCR4) and 31 downregulated genes common to all CXCR4 overexpressing clones. These observations demonstrate that overexpression of CXCR4 in NB stimulates tumour cell growth, survival, and chemotactic migration but is not sufficient to induce or enhance invasive and metastatic capacities. Activated pathways upon CXCR4 overexpression, identified through global gene expression profiling may be interesting targets for drugs inhibiting tumour growth.

Chiasmatic infiltration secondary to late malignant transformation of retinoma.

PURPOSE: To report the lethal course of malignant transformation of retinoma in an adult. METHODS: Case report. A 40-year-old patient presented with retinoma in his right eye and retinoblastoma in his left eye. Enucleation was recommended but refused and the patient received whole eye radiotherapy elsewhere. Five years later he presented again, with temporal hemianopsia of the left eye secondary to chiasmatic invasion. RESULTS: Diagnosis of retinoblastoma infiltration was confirmed by stereotactic biopsy of the chiasmatic lesion. Treatment with intravenous and intrathecal chemotherapy led to partial remission, and was followed by stereotactic irradiation of the chiasmatic mass and right optic nerve. The left eye was enucleated. Death occurred one year later due to cerebrospinal fluid metastases. CONCLUSION: Extraocular extension of retinoblastoma diagnosed in adulthood has never, to our knowledge, been reported. This case stresses the importance of lifelong retinoma monitoring and the necessity for radical treatment in the event of malignant transformation.

Neoadjuvant chemotherapy and extrapleural pneumonectomy of malignant pleural mesothelioma with or without hemithoracic radiotherapy (SAKK 17/04): a randomised, international, multicentre phase 2 trial.

BACKGROUND: Postoperative hemithoracic radiotherapy has been used to treat malignant pleural mesothelioma, but it has not been assessed in a randomised trial. We assessed high-dose hemithoracic radiotherapy after neoadjuvant chemotherapy and extrapleural pneumonectomy in patients with malignant pleural mesothelioma. METHODS: We did this phase 2 trial in two parts at 14 hospitals in Switzerland, Belgium, and Germany. We enrolled patients with pathologically confirmed malignant pleural mesothelioma; resectable TNM stages T1-3 N0-2, M0; WHO performance status 0-1; age 18-70 years. In part 1, patients were given three cycles of neoadjuvant chemotherapy (cisplatin 75 mg/m(2) and pemetrexed 500 mg/m(2) on day 1 given every 3 weeks) and extrapleural pneumonectomy; the primary endpoint was complete macroscopic resection (R0-1). In part 2, participants with complete macroscopic resection were randomly assigned (1:1) to receive high-dose radiotherapy or not. The target volume for radiotherapy encompassed the entire hemithorax, the thoracotomy channel, and mediastinal nodal stations if affected by the disease or violated surgically. A boost was given to areas at high risk for locoregional relapse. The allocation was stratified by centre, histology (sarcomatoid vs epithelioid or mixed), mediastinal lymph node involvement (N0-1 vs N2), and T stage (T1-2 vs T3). The primary endpoint of part 1 was the proportion of patients achieving complete macroscopic resection (R0 and R1). The primary endpoint in part 2 was locoregional relapse-free survival, analysed by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00334594. FINDINGS: We enrolled patients between Dec 7, 2005, and Oct 17, 2012. Overall, we analysed 151 patients receiving neoadjuvant chemotherapy, of whom 113 (75%) had extrapleural pneumonectomy. Median follow-up was 54·2 months (IQR 32-66). 52 (34%) of 151 patients achieved an objective response. The most common grade 3 or 4 toxic effects were neutropenia (21 [14%] of 151 patients), anaemia (11 [7%]), and nausea or vomiting (eight [5%]). 113 patients had extrapleural pneumonectomy, with complete macroscopic resection achieved in 96 (64%) of 151 patients. We enrolled 54 patients in part 2; 27 in each group. The main reasons for exclusion were patient refusal (n=20) and ineligibility (n=10). 25 of 27 patients completed radiotherapy. Median total radiotherapy dose was 55·9 Gy (IQR 46·8-56·0). Median locoregional relapse-free survival from surgery, was 7·6 months (95% CI 4·5-10·7) in the no radiotherapy group and 9·4 months (6·5-11·9) in the radiotherapy group. The most common grade 3 or higher toxic effects related to radiotherapy were nausea or vomiting (three [11%] of 27 patients), oesophagitis (two [7%]), and pneumonitis (two [7%]). One patient died of pneumonitis. We recorded no toxic effects data for the control group. INTERPRETATION: Our findings do not support the routine use of hemithoracic radiotherapy for malignant pleural mesothelioma after neoadjuvant chemotherapy and extrapleural pneumonectomy. FUNDING: Swiss Group for Clinical Cancer Research, Swiss State Secretariat for Education, Research and Innovation, Eli Lilly.

Use of surgery and carboplatin in feline malignant mammary gland neoplasms with advanced clinical staging

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CD44/CD24 immunophenotypes on clinicopathologic features of salivary glands malignant neoplasms

Abstract Background Salivary Glands Malignant Neoplasms (SGMNs) account for 3-6% of head and neck cancers and 0.3% of all cancers. Tumor cells that express CD44 and CD24 exhibit a stem-cell-like behavior. CD44 is the binding site for hyaluronic acid, and CD24 is a receptor that interacts with P-selectin to induce metastasis and tumor progression. The present study aims to evaluate the expression of CD44 and CD24 on SGMNs and correlated these data with several clinicopathologic features. Methods Immunohistochemical stains for CD44 and CD24 were performed on tissue microarrays containing SGMN samples from 69 patients. The CD44, CD24 and CD44/CD24 expression phenotypes were correlated to patient clinicopathologic features and outcome. Results CD44 expression was associated with the primary site of neoplasm (p = 0.046). CD24 was associated with clinical stage III/IV (p = 0.008), T stage (p = 0,27) and lymph node (p = 0,001). The CD44/CD24 profiles were associated with the primary site of injury (p = 0.005), lymph node (p = 0.011) and T stage (p = 0.023). Univariate analysis showed a significant relationship between clinical staging and disease- free survival (p = 0.009), and the overall survival presents relation with male gender (p = 0.011) and metastasis (p = 0.027). Conclusion In summary, our investigation confirms that the clinical stage, in accordance with the literature, is the main prognostic factor for SGMN. Additionally, we have presented some evidence that the analysis of isolated CD44 and CD24 immunoexpression or the two combined markers could give prognostic information associated to clinicopathologic features in SGMN. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1284611098470676.

Sarcomatous evolution of oligodendroglioma ("oligosarcoma"): confirmatory report of an uncommon pattern of malignant progression in oligodendroglial tumors

By analogy to gliosarcoma, the neologism "oligosarcoma" is to describe an uncommon form of biphasic central nervous system tumor composed of contiguous neuroepithelial and mesenchymal elements, each of which individually meet the criteria of oligodendroglioma and sarcoma, respectively. By virtue of its distinctive genotype (codeletion 1p/19q), oligodendroglioma is a particularly inviting paradigm to test the assumption that such mixed tumors are clonally derived from a glial primary. We observed this constellation in a 41-year-old male who underwent two resection procedures for a recurring right frontal tumor at five years' interval. On imaging, both lesions were contrast-enhancing, and measured 7 cm × 7 cm × 6.8 cm and 7 cm × 6.5 cm × 4cm, respectively. Following the first operation, temozolomide monotherapy was administered. Whereas initial histology showed conventional anaplastic oligodendroglioma, the recurrence consisted mostly of a fibrosarcoma-like, fascicular neoplasm that was immunoreactive for vimentin, smooth muscle actin, S100 protein, and focally epithelial membrane antigen. In between, a subset of otherwise indistinguishable spindle cells expressed GFAP, and focally merged with residues of oligodendroglioma. Molecular testing for loss of heterozygosity confirmed codeletion of 1p/19q in both the primary tumor and the sarcomatous recurrence. Similarly, generalized immunoreactivity for the mutant R132H form of isocitrate dehydrogenase in both lesions indicated an identical mutation of the IDH1 gene. By the above standards, biologically consistent "oligosarcomas" are felt to be exceedingly rare, and possibly participate of a nosologically heterogeneous group of combined glial/mesenchymal lesions that may also include iatrogenically induced second malignancies as well as true collision tumors.

Implications of Imaging Criteria for the Management and Treatment of Intraductal Papillary Mucinous Neoplasms - Benign versus Malignant Findings

OBJECTIVES Evaluation of computed tomography (CT) and magnetic resonance imaging (MRI) for differentiation of pancreatic intraductal papillary mucinous neoplasm (IPMN) subtypes based on objective imaging criteria. METHODS Fifty-eight patients with 60 histologically confirmed IPMNs were included in this retrospective study. Eighty-three imaging studies (CT,n = 42; MRI,n = 41) were analysed by three independent blinded observers (O1-O3), using established imaging criteria to assess likelihood of malignancy (-5, very likely benign; 5, very likely malignant) and histological subtype (i.e., low-grade (LGD), moderate-grade (MGD), high-grade dysplasia (HGD), early invasive carcinoma (IPMC), solid carcinoma (CA) arising from IPMN). RESULTS Forty-one benign (LGD IPMN,n = 20; MGD IPMN,n = 21) and 19 malignant (HGD IPMN,n = 3; IPMC,n = 6; solid CA,n = 10) IPMNs located in the main duct (n = 6), branch duct (n = 37), or both (n = 17) were evaluated. Overall accuracy of differentiation between benign and malignant IPMNs was 86/92 % (CT/MRI). Exclusion of overtly malignant cases (solid CA) resulted in overall accuracy of 83/90 % (CT/MRI). The presence of mural nodules and ductal lesion size ≥30 mm were significant indicators of malignancy (p = 0.02 and p < 0.001, respectively). CONCLUSIONS Invasive IPMN can be identified with high confidence and sensitivity using CT and MRI. The diagnostic problem that remains is the accurate radiological differentiation of premalignant and non-invasive subtypes. KEY POINTS • CT and MRI can differentiate benign from malignant forms of IPMN. • Identifying (pre)malignant histological IPMN subtypes by CT and MRI is difficult. • Overall, diagnostic performance with MRI was slightly (not significantly) superior to CT.

Expression of p53, {\it * ras\/} and PCNA in human colonic neoplasms: Possible biomarkers of malignant potential

Colorectal cancer is a leading cause of cancer mortality and early detection can significantly improve the clinical outcome. Most colorectal cancers arise from benign neoplastic lesions recognized as adenomas. Only a small percentage of all adenomas will become malignant. Thus, there is a need to identify specific markers of malignant potential. Studies at the molecular level have demonstrated an accumulation of genetic alterations, some hereditary but for the most occurring in somatic cells. The most common are the activation of ras, an oncogene involved in signal transduction, and the inactivation of p53, a tumor suppressor gene implicated in cell cycle regulation. In this study, 38 carcinomas, 95 adenomas and 20 benign polyps were analyzed by immunohistochemistry for the abnormal expression of p53 and ras proteins. An index of cellular proliferation was also measured by labeling with PCNA. A general overexpression of p53 was immunodetected in 66% of the carcinomas, while 26% of adenomas displayed scattered individual positive cells or a focal high concentration of positive cells. This later was more associated with severe dysplasia. Ras protein was detected in 37% of carcinomas and 32% of adenomas mostly throughout the tissue. p53 immunodetection was more frequent in adenomas originating in colons with synchronous carcinomas, particularly in patients with familial adenomatous polyposis and it may be a useful marker in these cases. Difference in the frequency of p53 and ras alterationbs was related to the location of the neoplasm. Immunodetection of p53 protein was correlated to the presence of a mutation in p53 gene at exon 7 and 5 in 4/6 carcinomas studied and 2 villous adenomas. Thus, we characterized in adenomas the abnormal expression of two proteins encoded by the most commonly altered genes in colorectal cancer. p53 alteration appears to be more specifically associated with transition to malignancy than ras. By using immunohistochemistry, a technique that keeps the architecture of the tissue intact, it was possible to correlate these alterations to histopathological characteristics that were associated with higher risks for transformation: villous content, dysplasia and size of adenoma. ^

Prolactin-immunoglobulin G complexes from human serum act as costimulatory ligands causing proliferation of malignant B lymphocytes.

Several lines of evidence indicate that immunoglobulin-bound prolactin found in human serum is not a conventional complex between an anti-prolactin antibody and prolactin but a different type of association of prolactin with the Fab portion of IgG heavy chains. The complex of prolactin with IgG was purified from serum by anti-human prolactin affinity chromatography and was shown to contain close to 1 mole of N epsilon-(gamma-glutamyl)lysine crosslinks per mole of complex, a characteristic feature in structures crosslinked by transglutaminase. Interestingly, the complex caused a proliferation of cells from a subset of patients with chronic lymphocytic leukemia, while it was inactive in a cell proliferation prolactin bioassay. By contrast, human prolactin stimulated the proliferation of cells in the bioassay but had no effect on the complex-responsive cells from the patients. Competition studies with prolactin and free Fc fragment of IgG demonstrated a necessity for engaging both the prolactin and the immunoglobulin receptors for proliferation. More importantly, competition for the growth response by free prolactin and IgG suggests both possible reasons for the slow growth of this neoplasm as well as avenues for control of the disease.

Molecular classification of cutaneous malignant melanoma by gene expression profiling

The most common human cancers are malignant neoplasms of the skin(1,2). Incidence of cutaneous melanoma is rising especially steeply, with minimal progress in non-surgical treatment of advanced disease(3,4). Despite significant effort to identify independent predictors of melanoma outcome, no accepted histopathological, molecular or immunohistochemical marker defines subsets of this neoplasm(2,3). Accordingly, though melanoma is thought to present with different 'taxonomic' forms, these are considered part of a continuous spectrum rather than discrete entities(2). Here we report the discovery of a subset of melanomas identified by mathematical analysis of gene expression in a series of samples. Remarkably, many genes underlying the classification of this subset are differentially regulated in invasive melanomas that form primitive tubular networks in vitro, a feature of some highly aggressive metastatic melanomas(5). Global transcript analysis can identify unrecognized subtypes of cutaneous melanoma and predict experimentally verifiable phenotypic characteristics that may be of importance to disease progression.

Molecular and functional characterization of the interplay between malignant and stromal cells in acute myeloid leukemia and myelodysplastic syndrome

In this thesis, we studied the cross-talk between malignant cells and stromal cells, with the aim to elucidate the respective contribution to myeloid neoplasm onset and progression. First, we characterized and compared mesenchymal stromal cells (MSCs) isolated from myelodysplastic syndrome (MDS-MSCs) and acute myeloid leukemia (AML-MSCs) patients. We demonstrated that, despite some unaltered functions, patient-derived MSCs show also intrinsic, distinct functional abnormalities, which could all potentially favor a leukemia-protective bone marrow (BM) niche in vivo. Second, we investigated the ability of AML cells to modulate the AML-MSC functions. In a GEP-screening, we found that 40% of BM-derived AML samples show a higher IFN-γ expression, compared to the mean IFN-γ expression in healthy BM-derived cells. We demonstrated that in co-culture experiments, IFN-γ+ AML cells modify AML-MSC gene expression and function, inducing the up-regulation of IDO1, and consequently the generation of T regulatory cells. Finally, we wondered if the transcriptome of stromal cells could be influenced by the hematopoietic-specific alterations, i.e. Dnmt3a and Asxl1 mutations, which occur early in MDS/AML patients. We found that Dnmt3a- and Asxl1-null BM cells, when transplanted in wild-type mice, induce profound and deletion-specific modifications in the transcriptome of wild-type BM stromal cells, suggesting the ability of Dnmt3a- and Asxl1-null BM cells to shape the niche. Furthermore, we compared the transcriptome of wild-type BM stromal cells, obtained from transplantation experiments, with that of MSCs isolated from low-risk MDS patients with DNMT3A and ASXL1 mutations, and we highlighted some common modifications, which could be potentially relevant for human disease and specific for DNMT3A/ASXL1 mutations. In conclusion, this thesis pointed out that there is a bi-directional cross-talk, in which stromal cells can influence malignant cells, and in turn malignant/pre-malignant cells can alter stromal cell gene expression and function. Both mechanisms could potentially contribute to the pathogenesis of myeloid malignancies.

Malignant Transformation Of An Odontogenic Cyst In A Period Of 10 Years.

Primary intraosseous carcinoma of the jaws (PIOSCC) might arise from odontogenic epithelium, more commonly from a previous odontogenic cyst. The aim of this case is to illustrate that the clinician should consider that an apparent benign dentigerous cyst can suffer malignant transformation and that all material removed from a patient must be evaluated histologically. A 44-year-old man presented in a routine periapical X-ray an impacted lower left third molar with radiolucency over its crown. Ten years later, the patient complained of pain in the same region and the tooth was extracted. After one month, the patient still complained of pain and suffered a fracture of the mandible. A biopsy was performed and carcinoma was diagnosed. The patient was treated surgically with adjuvant radio- and chemotherapy and after 8 years, he is well without signs of recurrences. This report describes a central mandibular carcinoma probably developed from a previous dentigerous cyst.

Low Molecular Weight Protein Tyrosine Phosphatase (lmwptp) Upregulation Mediates Malignant Potential In Colorectal Cancer.

Phosphatases have long been regarded as tumor suppressors, however there is emerging evidence for a tumor initiating role for some phosphatases in several forms of cancer. Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP; acid phosphatase 1 [ACP1]) is an 18 kDa enzyme that influences the phosphorylation of signaling pathway mediators involved in cancer and is thus postulated to be a tumor-promoting enzyme, but neither unequivocal clinical evidence nor convincing mechanistic actions for a role of LMWPTP have been identified. In the present study, we show that LMWPTP expression is not only significantly increased in colorectal cancer (CRC), but also follows a step-wise increase in different levels of dysplasia. Chemical inhibition of LMWPTP significantly reduces CRC growth. Furthermore, downregulation of LMWPTP in CRC leads to a reduced migration ability in both 2D- and 3D-migration assays, and sensitizes tumor cells to the chemotherapeutic agent 5-FU. In conclusion, this study shows that LMWPTP is not only overexpressed in colorectal cancer, but it is correlated with the malignant potential of this cancer, suggesting that this phosphatase may act as a predictive biomaker of CRC stage and represents a rational novel target in the treatment of this disease.