The antimetastatic activity of orlistat is accompanied by an antitumoral immune response in mouse melanoma.

PURPOSE: Fatty acid synthase (FASN), the multifunctional enzyme responsible for endogenous fatty acid synthesis, is highly expressed and associated with poor prognosis in several human cancers, including melanoma. Our group has previously shown that pharmacological inhibition of FASN with orlistat decreases proliferation, promotes apoptosis, and reduces the metastatic spread of B16-F10 cells in experimental models of melanoma. While most of the orlistat antitumor properties seem to be closely related to direct effects on malignant cells, its impact on the host immune system is still unknown. METHODS: The effects of orlistat on the phenotype and activation status of infiltrating leukocytes in primary tumors and metastatic lymph nodes were assessed using a model of spontaneous melanoma metastasis (B16-F10 cells/C57BL/6 mice). Cells from the primary tumors and lymph nodes were mechanically dissociated and immune cells phenotyped by flow cytometry. The expression of IL-12p35, IL-12p40, and inducible nitric oxide synthase (iNOS) was analyzed by qRT-PCR and production of nitrite (NO2-) evaluated in serum samples with the Griess method. RESULTS: Orlistat-treated mice exhibited a 25% reduction in the number of mediastinal lymph node metastases (mean 3.96 ± 0.78, 95% CI 3.63-4.28) compared to the controls (mean 5.7 ± 1.72; 95% CI 5.01-6.43). The drug elicited an antitumor immune response against experimental melanomas by increasing maturation of intratumoral dendritic cells (DC), stimulating the expression of cytotoxicity markers in CD8 T lymphocytes and natural killer (NK) cells, as well as reducing regulatory T cells (Tregs). Moreover, the orlistat-treatment increased serum levels of nitric oxide (NO) concentrations. CONCLUSION: Taken together, these findings suggest that orlistat supports an antitumor response against experimental melanomas by increasing CD80/CD81-positive and IL-12-positive DC populations, granzyme b/NKG2D-positive NK populations, and perforin/granzyme b-positive CD8 T lymphocytes as well as reducing Tregs counts within experimental melanomas.

Impact of Brush Cytology Analysis for the Diagnosis of Esophageal Squamous Cell Carcinoma: The Quality of Liquid-Based Preparation of Cytological Slides.

OBJECTIVES: The diagnostic performance of cytology in esophageal squamous cell carcinoma (ESCC) is meticulously described. METHODS: Cytological and biopsy specimens were prospectively taken during esophagogastroduodenoscopy of 123 individuals in 2013 and 2014. Cytology samples were maintained in preservative fluid until processing and biopsies were formalin-fixed and paraffin-embedded. RESULTS: Based on endoscopic biopsy results, 70 cases were positive for ESCC whilst 53 were negative for cancer. In addition, brush cytology showed high sensitivity and specificity (98.57 and 96.23%, respectively) in detecting the disease, and high accuracy (97.5%) comparable to that provided by histopathology which is the accepted gold standard. CONCLUSION: Brush cytology specimens preserved in liquid medium may be a good alternative for ESCC diagnosis.

Paracoccin, an N-acetyl-glucosamine-binding lectin of Paracoccidioides brasiliensis, is involved in fungal growth.

Paracoccin is an N-acetyl-glucosamine-binding lectin from Paracoccidioides brasiliensis, which can be obtained in small amounts either from culture supernatants or yeast cell extracts. In the present work, immunoelectron microscopy with mouse anti-paracoccin IgG localized the antigen to the cell wall of P. brasiliensis yeast forms. Paracoccin interacted with chitin, and colocalized with beta-1,4-homopolymer of GlcNAc to the budding sites of P. brasiliensis yeast cell. In order to evaluate the role of paracoccin on fungal growth, yeast cells were cultivated in the presence of anti-paracoccin antibodies. A significant reduction of both colony forming units and individual yeast cells was observed as well as morphological alterations such as smaller colonies and cells more loosely aggregated than in control cultures without the antibody. A role of paracoccin on the cell wall organization was reinforced by alterations in the labeling pattern of chitin when yeasts were treated with anti-paracoccin antibodies. Binding of specific antibodies to paracoccin may disrupt the paracoccin/chitin interactions, resulting in the inhibition of P. brasiliensis growth.

Paracoccin, an N-acetyl-glucosamine-binding lectin of Paracoccidioides brasiliensis, is involved in fungal growth

Paracoccin is an N-acetyl-glucosamine-binding lectin from Paracoccidioides brasiliensis, which can be obtained in small amounts either from culture supernatants or yeast cell extracts. In the present work, immunoelectron microscopy with mouse anti-paracoccin IgG localized the antigen to the cell wall of P. brasiliensis yeast forms. Paracoccin interacted with chitin, and colocalized with â-1,4-homopolymer of GlcNAc to the budding sites of P. brasiliensis yeast cell. In order to evaluate the role of paracoccin on fungal growth, yeast cells were cultivated in the presence of anti-paracoccin antibodies. A significant reduction of both colony forming units and individual yeast cells was observed as well as morphological alterations such as smaller colonies and cells more loosely aggregated than in control cultures without the antibody. A role of paracoccin on the cell wall organization was reinforced by alterations in the labeling pattern of chitin when yeasts were treated with anti-paracoccin antibodies. Binding of specific antibodies to paracoccin may disrupt the paracoccin/chitin interactions, resulting in the inhibition of P. brasiliensis growth.

Paracoccin, a GlcNAc-binding lectin from Paracoccidioides brasiliensis, binds to laminin and induces TNF-alpha production by macrophages.

Paracoccidioides brasiliensis components interact with host cells and can influence the pathogenesis of paracoccidioidomycosis (PCM). Among the components released by P. brasiliensis, gp 43 and a heavily glycosylated antigen with MM>160 kDa are the most recognized by serum antibodies from patients with PCM. In order to isolate the high MM glycoconjugate, we carried out affinity chromatography of a crude exoantigen preparation on immobilized jacalin. The bound fraction (JBE, jacalin binding exoantigen) consisted of a major antigen of high MM and frequently of an additional 70-kDa minor protein. This protein, designated paracoccin, exhibited selective binding to immobilized GlcNAc, a property that was used for its purification. The structural data of paracoccin obtained by mass spectrometry of tryptic peptides did not match any known protein. Anti-paracoccin serum localized the lectin on the surface of P. brasiliensis yeasts, especially in the budding regions. Paracoccin was able to interact with laminin in a dose-dependent manner. This interaction was inhibited by GlcNAc, followed by D-glucose and D-mannose, but not by D-galactose, N-acetyl-galactosamine or L-fucose. Interestingly, paracoccin induced both resident and elicited mouse peritoneal cavity macrophages to release high and persistent levels of TNF-alpha in vitro, a fact that was associated with high nitric oxide production in elicited cells. Because binding to laminin can favor yeast adhesion and invasion of host tissues, and overproduction of NO has been associated with suppression of cell immunity, paracoccin is suggested to play an important role in PCM pathogenesis.