Expression of the Wilms' tumour gene and its association with PPARß/δ in healthy skin and melanoma of horses.

The Wilms' tumour gene (WT1) has previously been described as an oncogene in several neoplasms of humans, including melanoma, and its expression increases cancer cell proliferation. Recent reports associate the expression of the PPARß/δ gene (peroxisome proliferator-activated receptor beta/delta) with the downregulation of WT1 in human melanoma and murine melanoma cell lines. The aim of this work was to analyse the expression of WT1 and its association with PPARß/δ in samples of healthy and melanoma-affected skin of horses by immunohistochemistry. WT1 protein expression was detected in healthy skin, mainly in the epidermis, hair follicle, sebaceous gland and sweat gland, while no expression was observed in equine melanoma tissues. Moreover, it was observed that PPARß/δ has a basal expression in healthy skin and that it is overexpressed in melanoma. These results were confirmed by a densitometric analysis, where a significant increase of the WT1-positive area was observed in healthy skin (128.66 ± 19.84 pixels 106) compared with that observed in melanoma (1.94 ± 0.04 pixels 106). On the other hand, a positive area with an expression of PPARß/δ in healthy skin (214.94 ± 11.85 pixels 106) was significantly decreased compared to melanoma (624.86 ± 181.93 pixels 106). These data suggest that there could be a regulation between WT1 and PPARß/δ in this disease in horses.

Analysis of the Anti-Inflammatory Capacity of Bone Broth in a Murine Model of Ulcerative Colitis.

Background and Objectives: Nutritional deficiencies are one of the main triggers for the development of gastrointestinal diseases, such as ulcerative colitis (UC). Therefore, the objective of the present work consisted of determining the nutrients present in the bone broth (BB) and evaluating their anti-inflammatory properties in a murine model of UC, induced by intrarectal administration of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS), and acetic acid (AcOH). The BB was prepared from the femur of bovine cattle and cooked in distilled water for 8 h at 100 ± 2 °C. Materials and Methods: The BB was administered ad libitum to BALB/c mice for 10 days before the induction of UC. Colon samples were collected for histological analysis and determination of cytokine expression levels by qPCR. Results: It was found that amino acids (AA) are the main nutritional contribution of BB, 54.56% of these correspond to essential AA. The prophylactic administration of BB in the murine model of UC reduced histological damage, decreased the expression of IL-1ß (61.12%), IL-6 (94.70%), and TNF-α (68.88%), and increased the expression of INF-γ (177.06%), IL-4 (541.36%), and IL-10 (531.97%). Conclusions: This study shows that BB has anti-inflammatory properties, and its consumption can decrease the symptoms of UC.

Distribution of M1 and M2 macrophages in cerebral granulomas caused by Encephalitozoon cuniculi.

Encephalitozoon cuniculi spores cause severe granulomatous inflammation in the brain where mononuclear cells and macrophages infiltrate. Here, we orally infected New Zealand white rabbits with 1 × 106E. cuniculi viable spores to study the recruitment and localization of macrophages in brain granulomas. At day 30 post-infection, the positive phenotype markers iNOS (M1) and Arg-1 (M2) were located in the periphery and center of granulomas, respectively. Live intracytoplasmic spores were found only in positive Arg-1 cells. This is the first work to describe the recruitment and distribution of M1 and M2 macrophages in the brain granulomas of rabbits infected with E. cuniculi.

Mouse mammary tumor virus-like gene sequences are present in lung patient specimens.

BACKGROUND: Previous studies have reported on the presence of Murine Mammary Tumor Virus (MMTV)-like gene sequences in human cancer tissue specimens. Here, we search for MMTV-like gene sequences in lung diseases including carcinomas specimens from a Mexican population. This study was based on our previous study reporting that the INER51 lung cancer cell line, from a pleural effusion of a Mexican patient, contains MMTV-like env gene sequences. RESULTS: The MMTV-like env gene sequences have been detected in three out of 18 specimens studied, by PCR using a specific set of MMTV-like primers. The three identified MMTV-like gene sequences, which were assigned as INER6, HZ101, and HZ14, were 99%, 98%, and 97% homologous, respectively, as compared to GenBank sequence accession number AY161347. The INER6 and HZ-101 samples were isolated from lung cancer specimens, and the HZ-14 was isolated from an acute inflammatory lung infiltrate sample. Two of the env sequences exhibited disruption of the reading frame due to mutations. CONCLUSION: In summary, we identified the presence of MMTV-like gene sequences in 2 out of 11 (18%) of the lung carcinomas and 1 out of 7 (14%) of acute inflamatory lung infiltrate specimens studied of a Mexican Population.

Mixed Pneumoconiosis Associated with Diffuse Pulmonary Ossification in Wild Coyotes (Canis latrans).

Mixed pneumoconiosis is a pulmonary disease associated with several inhaled mineral irritants. Dust was found in the alveolar macrophages, alveolar and bronchial walls and pulmonary interstitial tissue of two female coyotes (Canis latrans). The dust contained large amounts of silica, coal, iron and copper particles, which were associated with severe pulmonary disease. Lung injury in the animals was characterized by pulmonary nodules, severe interstitial fibrosis, alveolar hyperplasia and bone formation within alveolar spaces. Coyotes inhaled mineral dust while roaming a field close to three mineral extraction zones. To our knowledge, this is the first report of the concomitant inhalation of multiple minerals in association with diffuse pulmonary ossification in the pulmonary parenchyma of two wild canine animals.

Effects of Transportation Stress on Complete Blood Count, Blood Chemistry, and Cytokine Gene Expression in Heifers.

Blood samples were obtained from 16 high-risk heifers; eight were newly arrived from a 40 h road trip (0 days post-arrival (DPA)), whereas the other eight heifers had been in the feedlot at 25 DPA. Both groups were transported from the southeast tropical region of Mexico to a feedlot in the northeast and were sampled on the same day. The complete blood count, blood chemistry, and cytokine gene expression were analyzed. Gene expression was analyzed using specific primers to amplify and quantify the cDNA reverse transcribed from the mRNA transcripts for tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2. Higher values for hematocrit (p = 0.029), hemoglobin (p = 0.002), eosinophils (0.029), albumin (p = 0.014), alanine aminotransferase (p = 0.004), bilirubin (p = 0.003), cholesterol (p = 0.014), and cortisol (p = 0.051) were observed in the 0 DPA group than the 25 DPA group. In the electrophoresis of TNF-α amplification products, two non-specific bands were observed in the 0 DPA group. These bands were sequenced, and BLAST analysis suggested that they corresponded to bovine lymphotoxin and have not been reported previously related to stress. The TNF-α expression level was higher (p = 0.001) in the 25 DPA group than the 0 DPA group according to the semi-quantitative expression analysis. This may indicate a persistent inflammatory process that could be related to trauma and disease, which can negatively impact their subsequent health and growth performance. In conclusion, homeostatic disruption was apparent in the 0 DPA heifers, which showed higher cortisol and reductions in TNF-α levels and stress-induced bovine lymphotoxin (SIBL) co-expression.

Quantitative analysis of TNF-α, IL-4, and IL-10 expression, nitric oxide response, and apoptosis in Encephalitozoon cuniculi-infected rabbits.

The expression of tumor necrosis factor (TNF) -α, interleukin (IL) -4 and IL-10, as well as apoptosis and nitric oxide (NO) levels were measured in the brain and kidneys of immunocompetent and immunosuppressed New Zealand White rabbits infected with Encephalitozoon cuniculi. All of the animals had clinical signs histopathological lesions compatible with encephalitozoonosis and were E. cuniculi-positive by using a carbon immunoassay test. Encephalitozoon cuniculi infection promoted the expression of TNF-α and NO production in the kidneys of infected rabbits, and a synergic effect was observed in animal treated with dexamethasone. The IL-4 expression was similar in the brain and kidneys of infected rabbits, regardless of their immunologic status. The IL-10 mRNA expression in the brain of infected immunosuppressed rabbits was elevated when compared with positive controls. Apoptosis of granuloma mononuclear-like cells was detected in immunocompetent E. cuniculi-infected rabbits, but it was more evident in infected-immunosuppressed animals. Nitric oxide levels were elevated both in immunocompetent and immunosuppressed infected animals, but it was more apparent in the kidneys. These data suggest that modulation of the immune response by E. cuniculi could contribute to the survival of the parasite within phagocytic cells in granulomas via an as yet undetermined mechanism.

RNAi silencing of the WT1 gene inhibits cell proliferation and induces apoptosis in the B16F10 murine melanoma cell line.

The Wilms' tumor protein 1 (WT1) is essential for tumor cell proliferation and is highly expressed in various hematological and solid malignancies including human malignant melanoma. We investigated whether WT1 expression is essential for growth in the B16F10 murine melanoma cell line. Toward this end, we examined WT1 protein expression and WT1 isoforms (17AA+/17AA-, KTS+/KTS-) in this cell line. WT1 was silenced by two RNA interference constructs, designated WT1-1 and WT1-2. RNA interference-mediated reduction of WT1 protein expression significantly inhibited B16F10 cell viability. Loss of WT1 also increased caspase-3 and poly-ADP-ribose polymerase activation, as well as apoptotic body formation, chromatin condensation, and DNA fragmentation. Together, these findings implicate decreased WT1 protein levels in the induction of apoptosis. These results imply that WT1 plays a distinct role in B16F10 melanoma growth.

WT1 expression as a potential biomarker of malignancy in canine breast tumor / La expresión de WT1 como un biomarcador potencial maligno en un tumor de mama canino

SUMMARY: Veterinary oncology is very important nowadays to get a better understanding of human carcinogenesis. Estrogen receptor, progesterone receptor and Human Epidermal Growth Factor receptor 2 are frequently evaluated by immunohistochemistry (HIC) in human breast tumor. WT1 is an oncogene, its overexpression has been detected in leukemia and diverse solid tumors like breast cancer, lung cancer and mesothelioma in humans. WT1 expression was evaluated in 15 canine breast tumors (CBT) diagnosed by histopathological analysis to find its relationship with neoplasia and malignancy. IHC and RT-PCR were performed in CBT tissues. Fisher´s test was used to analyze WT1 relationship with malignancy. Of the 15 tumors, 9 (60 %) were diagnosed as benign and 6 (40 %) were malignant. With IHC, WT1 expression was positive only in biopsies diagnosed as malignant. Expression of WT1 by RT-PCR was detected in 14 of the 15 tumors (93.33 %) as well as in control healthy mammary gland. Clinical significance: This study describes for the first time a close correlation between CBT and a positive result for WT1 expression with IHC; hence, it can be used as a biomarker for this neoplasia and as an indicator of malignancy. RT-PCR analysis also showed to be good option to detect WT1 expression. These results will be useful to further investigations to elucidate WT1-related signaling pathways in CBT. Also to know molecules that regulate the translation of this protein as a marker for tumor progression.

RESUMEN: La oncología veterinaria es muy importante hoy en día para comprender mejor la carcinogénesis humana. El receptor de estrógeno, el receptor de progesterona y el receptor 2 del factor de crecimiento epidérmico humano se evalúan con frecuencia mediante inmunohistoquímica (HIC) en tumores de mama humanos. WT1 es un oncogén, su sobreexpresión se ha detectado en leucemia y en diversos tumores sólidos como el cáncer de mama, cáncer de pulmón y mesotelioma en humanos. La expresión de WT1 se evaluó en 15 tumores de mama caninos (TCC) diagnosticados mediante análisis histopatológico para encontrar su relación con la neoplasia y la malignidad. IHC y RT-PCR se realizaron en tejidos CBT. La prueba de Fisher se utilizó para analizar la relación de WT1 con la malignidad. De los 15 tumores, 9 (60 %) fueron diagnosticados como benignos y 6 (40 %) fueron malignos. Con IHC, la expresión de WT1 fue positiva solo en biopsias diagnosticadas como malignas. La expresión de WT1 por RT-PCR se detectó en 14 de los 15 tumores (93,33 %), así como en el control de la glándula mamaria sana. Importancia clínica: este estudio describe por primera vez una estrecha correlación entre la TCC y un resultado positivo para la expresión de WT1 con IHC; por lo tanto, se puede utilizar como un biomarcador para esta neoplasia y como un indicador de malignidad. El análisis por RT-PCR también demostró ser una buena opción para detectar la expresión de WT1. Estos resultados serán útiles para futuras investigaciones para dilucidar las vías de señalización relacionadas con WT1 en la TCC. También para conocer moléculas que regulan la traducción de esta proteína como marcador de progresión tumoral.

WT1 silencing by RNAi synergizes with chemotherapeutic agents and induces chemosensitization to doxorubicin and cisplatin in B16F10 murine melanoma cells.

The Wilm's tumor gene (WT1), encoding a transcription factor that modulates the expression of certain genes that are involved in proliferation and apoptosis, is overexpressed in numerous solid tumors. WT1 is important for cell proliferation and in the diagnosis of melanoma. The objectives of this study were to investigate whether WT1 silencing is capable of synergizing with chemotherapeutic agents and whether this silencing is capable of sensitizing cancer cells to doxorubicin and cisplatin in the B16F10 murine melanoma cell line. In the present study, B16F10 cells were simultaneously treated with median lethal doses (LD50s) of WT1-1 or WT1-2 small hairpin RNAs (shRNAs) and chemotherapeutic agents. A total of 24 h post-transfection, a [3-(4,5-dimethylthiazol-2yl)-2,5- diphenyl tetrazolium bromide assay] MTT assay was performed. To determine whether shRNA interference (shRNAi) is capable of sensitizing B16F10 cells to chemotherapeutic agents, cells were transfected with an LD50 of each of the recombinant plasmids, treated with varying concentrations of doxorubicin or cisplatin 24 h post-transfection, and analyzed 48 h later for inhibition of cell proliferation using the MTT assay. We observed that WT1-RNAi and the two chemotherapeutic agents acted synergistically to inhibit B16F10 cell proliferation. The greatest inhibition of cell proliferation was observed with the WT1-2/cisplatin (91%) and WT1-1/cisplatin combinations (85%). WT1 silencing using shRNAi induced the chemosensitization of cells to doxorubicin and cisplatin, with the greatest inhibition (85%) of cell proliferation being observed in the cells treated with the WT1-2/cisplatin 6 ng/µl combination. Our results provide direct evidence that WT1 gene silencing has a synergistic effect with chemotherapeutic drugs and sensitizes B16F10 melanoma cells to doxorubicin and cisplatin. This suggests that these combination strategies are potentially utilized in melanoma therapy.

Expression of prostate apoptosis response (Par-4) is associated with progesterone receptor in breast cancer.

BACKGROUND: The prostate apoptosis response (Par-4) gene encodes a proapoptotic protein that selectively induces apoptosis in cancer cells after diverse apoptotic stimuli. Par-4 expression and its association with other biomarkers have not been reported in breast cancer. The purpose of this study was to determine Par-4 expression in breast cancer samples and its association with other biomarkers and clinical factors (T-stage, age, nodal status). METHODS: Paraffin-embedded section samples of breast cancer were evaluated by immunohistochemical analysis to determine Par-4, estrogen receptor (ER), progesterone receptor (PgR), c-erbB2, Ki67, p53 and bcl-2 expression. The correlation between Par-4 and the other biomarkers and clinical factors was determined by multivariate analysis. RESULTS: Thirty five percent (n=21) of samples were PAR-4 positive and 64.4% (n=38) were negative. The hormonal status was 64% ER positive (n=38), 35% ER-negative (n=21) and 40.7% PgR positive (n=24), 59.3% PgR negative (n=35). The majority (90%) of the samples presented clear cytoplasmic localization and a small portion (10%) was cytoplasmic and nuclear. Univariate analysis indicates that the Par-4 expression has a significant inverse association (p=0.04) only with expression of PgR and not with the other variables analyzed. Normal breast tissue analyzed was negative for Par-4 immunostaining. CONCLUSIONS: Our results suggest that, in breast cancer, Par-4 plays a similar tumor suppressor gene role as reported in endometrial carcinoma.