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Biomedical subjects

Carol Farver

Publications and source records attributed to Carol Farver.

15 recordsLinked to original sources
PubMed2006

Efficacy of SSG and SSG/IFNalpha2 against human prostate cancer xenograft tumors in mice: a role for direct growth inhibition in SSG anti-tumor action.

BACKGROUND: Pre-clinical activity of SSG against melanoma and renal cancer has been identified recently although the drug's mechanism of action and activity against tumors of additional histological-types remain undefined. METHODS: The effects of SSG and SSG combination with other agents on DU145 human prostate carcinoma xenograft tumors in mice and on DU145 cell subpopulations of differential SSG sensitivities were evaluated. RESULTS: DU145 tumor growth was inhibited by SSG (69%), IFNalpha2 (33%) or the combination (80%) that induced complete regression of WM9 human melanoma tumors. DU145 cells in culture were also partially growth inhibited by SSG at killing doses (200-800 mug/ml) for WM9 cells, indicating a correlation of SSG inhibition of cancer cell growth in vitro and in vivo. DU145 cells formed multiple micro tumors in mice treated with SSG or SSG/IFNalpha2 in contrast to the single large tumors in the control or IFNalpha2-treated mice, suggesting the existence of an SSG-resistant subpopulation in DU145 cells. Indeed, DU145 but not WM9 cells formed colonies (approximately 4% frequency) when cultured in the presence of SSG. Single cell clone (DU145-7) isolated from DU145 cells showed SSG-resistant growth in culture, unassociated with cross-resistance to IFNalpha2 and converted to SSG-responsive cells by BSO that inhibited intracellular glutathione levels. CONCLUSIONS: These results implicate a role for direct growth inhibition in SSG anti-tumor action, provide novel insights into the mechanism of tumor resistance to the drug and suggest a therapeutic potential for SSG and its combinations with IFNalpha2 or BSO for prostate cancer that warrants further investigation.

Animals↗
PubMed2006

Melanoma antigen A4 is expressed in non-small cell lung cancers and promotes apoptosis.

A variety of melanoma antigen A (MAGE-A) genes are commonly detected in non-small cell lung cancers. Their biological function is not well characterized but may involve the regulation of apoptosis and cell cycle progression. We hypothesized that MAGE-A4 is involved in the regulation of apoptosis. To investigate this, expression of MAGE-A was evaluated. MAGE-A4 was expressed in 48% of non-small cell lung carcinomas. Ninety percent of lung carcinomas expressing MAGE-A4 were classified as squamous cell carcinomas and 10% were adenocarcinomas. Tumor-free surrounding lung tissue was negative for MAGE-A4. A molecular clone of MAGE-A4 derived from human lung cancer was stably expressed in human embryonic kidney cells (293 cells) to evaluate effects on cell death. Overexpression of MAGE-A4 increased apoptosis as measured by the apoptotic index (P < 0.0001) and caspase-3 activity (P < 0.002). Exposure to 25 micromol/L etoposide, a chemotherapeutic agent, increased the apoptotic effect (P < 0.0001). Furthermore, we show that MAGE-A4 silencing using a small interfering RNA approach results in decreased caspase-3 activity in the squamous cell lung cancer cell line H1703 by 58% (P = 0.0027) and by 24% (P = 0.028) in 293/MAGE-A4 cells. These findings suggest that MAGE-A4 expression may promote tumor cell death, sensitize malignancies to apoptotic stimuli, such as chemotherapeutic agents, and therefore may represent a tumor suppressor protein.

Aged↗
PubMed2004

Increased arginase II and decreased NO synthesis in endothelial cells of patients with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH), a fatal disease of unknown etiology characterized by impaired regulation of pulmonary hemodynamics and vascular growth, is associated with low levels of pulmonary nitric oxide (NO). Based upon its critical role in mediating vasodilation and cell growth, decrease of NO has been implicated in the pathogenesis of PAH. We evaluated mechanisms for low NO and pulmonary hypertension, including NO synthases (NOS) and factors regulating NOS activity, i.e. the substrate arginine, arginase expression and activity, and endogenous inhibitors of NOS in patients with PAH and healthy controls. PAH lungs had normal NOS I-III expression, but substrate arginine levels were inversely related to pulmonary artery pressures. Activity of arginase, an enzyme that regulates NO biosynthesis through effects on arginine, was higher in PAH serum than in controls, with high-level arginase expression localized by immunostaining to pulmonary endothelial cells. Further, pulmonary artery endothelial cells derived from PAH lung had higher arginase II expression and produced lower NO than control cells in vitro. Thus, substrate availability affects NOS activity and vasodilation, implicating arginase II and alterations in arginine metabolic pathways in the pathophysiology of PAH.

Arginase↗
PubMed2004

Correlation between viral loads of cytomegalovirus in blood and bronchoalveolar lavage specimens from lung transplant recipients determined by histology and immunohistochemistry.

Cytomegalovirus (CMV) is an important pathogen in lung transplant recipients. Early detection of CMV end-organ disease should help with treatment management. We determined the CMV viral load by hybrid capture in bronchoalveolar lavage (BAL) fluid samples from patients who had undergone lung transplantation. For 39 of these samples (from 25 patients), corresponding transbronchial biopsy samples were available for CMV immunohistochemistry (IHC). The CMV IHC results were interpreted and categorized as positive or negative, and the positive results were subcategorized as typical if cells with both significant nuclear enlargement or Cowdry A-type inclusions and positive staining were present or as atypical if definitive nuclear staining was seen but significant nuclear enlargement was not. Diagnostic CMV viral inclusions were reported in the anatomic diagnosis, based on hematoxylin-eosin staining alone, for three (8%) of the biopsy samples. CMV was detected by IHC in 13 (33%) samples (5 typical, 8 atypical). The median CMV viral load in BAL samples was 0 copies/ml for BAL samples from patients with IHC-negative biopsy samples; 47,678 copies/ml for BAL samples from patients with biopsy samples with positive, atypical staining; and 1,548,827 copies/ml for BAL samples from patients with biopsy samples with positive, typical staining (P < 0.001). Compared to routine pathology of biopsy samples, the use of IHC increased the diagnostic yield of CMV. Also, the CMV viral load in BAL fluid samples increased along with immunoreactivity from negative to positive, atypical staining to positive, typical staining. The CMV viral load determined with the end-organ sample, the BAL fluid sample, was higher than the corresponding viral load determined with blood. Both IHC and determination of the CMV viral load in BAL samples may be useful for the detection of individuals at risk for the development of fulminant invasive CMV disease.

Bronchoalveolar Lavage Fluid↗
PubMed2003

Mucosal apposition in endoscopic suturing.

BACKGROUND: The proliferation of minimally invasive surgery has led to the development of numerous entirely intracorporeal endoscopic suturing techniques. These techniques allow for simple apposition of the GI mucosa. It is yet to be determined whether this results in long-term mucosal apposition. This study was designed to determine whether the current techniques of endoscopic suturing necessitate preliminary mucosal manipulation. METHODS: Seven dogs underwent laparotomy and gastrotomy to expose the proximal gastric mucosa. Three different suturing techniques were used to appose adjacent tissue folds: simple mucosal apposition, electrosurgical mucosal ablation before closure, and mucosal resection before closure. Apposition sites were scored histologically, based on tissue healing after 2 weeks. RESULTS: Mucosal ablation before tissue apposition resulted in significantly greater healing compared with simple apposition and resulted in histologic scoring similar to that for mucosal resection. The mean histologic score after ablation was 1.5, vs. 1.25 after mucosal resection, and 0.9 for sites closed simply (p=0.02). CONCLUSIONS: Endoscopic suturing techniques may one day offer an alternative to surgical treatment in the management of numerous GI conditions. As this modality evolves, the incorporation of target tissue ablation or mucosal resection before tissue apposition requires consideration. Human studies evaluating the safety and long-term efficacy of these modifications are necessary.

Animals↗
PubMed2003

Analysis of microsatellite instability and X-inactivation in ovarian borderline tumors lacking numerical abnormalities by comparative genomic hybridization.

The genetic events underlying development of ovarian borderline tumors (tumors of low malignant potential) are not well understood. In our previous studies of microdissected samples from serous borderline tumors, comparative genomic hybridization (CGH) and/or fluorescence in situ hybridization (FISH) analyses showed that 3 of 13 tumors had detectable numerical abnormalities; the remaining 10 had none. In the present study, we examined microsatellite instability (MSI) and clonality in this same set of tumors. Although absence of chromosomal imbalances has been associated with the presence of MSI in some types of solid tumors, the extent of MSI in borderline tumors, and its role in their pathogenesis, is unclear. In our set of 13 tumors, no MSI was detected despite analysis with microsatellite markers recommended by the National Cancer Institute for assessment of MSI. Quantitative X-inactivation studies were informative at the androgen receptor gene AR in 9 of the 13 tumors and revealed that each of the 9 tumors was clonal. In two patients, bilateral tumors showed identical patterns of skewed X-inactivation. These studies confirm the clonality of borderline tumors and suggest that some borderline tumors may develop through mechanisms other than chromosomal imbalances or microsatellite instability.

Adult↗
PubMed2003

Relative importance of CCR5 and antineutrophil cytoplasmic antibodies in patients with Wegener's granulomatosis.

OBJECTIVE: Wegener's granulomatosis (WG) is an idiopathic inflammatory condition characterized by upper and lower airway involvement and often renal dysfunction. Sites of tissue injury include pleomorphic cell populations, and classically mononuclear cell infiltrates that may form granulomas. Vascular inflammation (i.e., vasculitis) is often but not always present. Because CCR5 and its ligands influence mononuclear cell trafficking, we sought to identify their expression in pulmonary lesions and to determine whether genetic variations in genes for CCR5 and its ligands influence susceptibility to WG. METHODS: Lung biopsies from 4 patients that had classical features of WG were examined for protein expression of CCR5, RANTES, MIP-1alpha and MIP-1beta using immunohistochemistry. One hundred eighteen Caucasian patients with WG and 127 ethnically matched healthy controls were included in the genetic analysis. Genomic DNA samples were amplified by PCR. CCR5 Delta32 and RANTES -28 and -401 polymorphisms were determined by either specific primers or direct sequencing. RESULTS: CCR5+ cells were enriched in lung lesions from patients with WG. Enhanced protein concentrations of RANTES, MIP-1alpha, and MIP-1beta were present in WG lung lesions, indicating redundancy of ligands for CCR5 in affected tissue. Genetic analyses revealed 3 subsets of patients with WG: (1) circulating antineutrophil cytoplasmic antibody (ANCA) positive and CCR5+/+ (58%); (2) CCR5+/+ and ANCA negative (22%); and (3) CCR5 Delta32 and ANCA positive (20%). Among patients in whom ANCA were repeatedly absent, none was found to carry the CCR5 Delta32 allele. Conversely, patients who possessed the CCR5 Delta32 allele were always ANCA positive. CONCLUSION: CCR5 and its ligands are abundantly present in pulmonary lesions in WG. The absence of a genetic deletion for CCR5 (CCR5 Delta32) in WG patients lacking ANCA suggests that CCR5 may exert a particularly important pathogenetic role in those patients. Another subset of patients (approximately 20%) with WG possessed a genetic deletion for CCR5. That each of these patients was ANCA positive implies that an alternative pathway to CCR5 may exist, for which ANCA may be especially important.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2002

Anticancer activity of sodium stibogluconate in synergy with IFNs.

Cancer cell resistance limits the efficacy of IFNs. In this study, we show that sodium stibogluconate (SSG) and IFN-alpha synergized to overcome IFN-alpha resistance in various human cancer cell lines in culture and eradicated IFN-alpha-refractory WM9 human melanoma tumors in nude mice with no obvious toxicity. SSG enhanced IFN-alpha-induced Stat1 tyrosine phosphorylation, inactivated intracellular SHP-1 and SHP-2 that negatively regulate IFN signaling, and induced cellular protein tyrosine phosphorylation in cancer cell lines. These effects are consistent with inactivation of phosphatases as the basis of SSG anticancer activity. Characterization of SSG by chromatography revealed that only selective compounds in SSG were effective protein tyrosine phosphatase inhibitors. These observations suggest the potential of SSG as a clinically usable protein tyrosine phosphatase inhibitor in cancer treatment and provide insights for developing phosphatase-targeted therapeutics.

Adjuvants, Immunologic↗
PubMed2002

Syndrome of iron pill aspiration.

Bronchial stenosis (BS) consequent to iron pill aspiration (IPA) has been observed in few reported cases. This condition is often irreversible and may necessitate lobectomy in severe cases. Unlike most foreign bodies (FBs), the iron pill disintegrates in the airway and cannot be detected on bronchoscopy. However, bronchial biopsy and lung tissue may reveal iron deposits along with airway inflammation months after the aspiration. Thus, IPA can be diagnosed by a triad of aspiration, airway inflammation, and iron deposits on histology even in the absence of an FB. We report a case of IPA with BS in which the diagnosis was established by bronchial biopsy and was successfully managed with balloon bronchoplasty and therapy with topical mitomycin C.

Aged↗
PubMed2002

Pentamidine is an inhibitor of PRL phosphatases with anticancer activity.

The PRL family oncogenic phosphatases are attractive targets for developing inhibitors as anticancer therapeutics given their potentially pathogenic role in human malignancies. Herein we demonstrate that pentamidine, an anti-protozoa drug with an unknown mechanism of action, is an inhibitor of PRLs with anticancer potential. Pentamidine at its therapeutic doses inhibited recombinant PRL phosphatases in vitro and inactivated ectopically expressed PRLs in NIH3T3 transfectants with an effective duration more than 24 h after a pulse cell treatment. The drug had in vitro growth-inhibitory activity against human cancer cell lines that express the endogenous PRLs. Pentamidine at a tolerable dose markedly inhibited the growth of WM9 human melanoma tumors in nude mice coincident with the induction of tumor cell necrosis and is capable of inactivating ectopically expressed PRL-2 in the cancer cells. These observations suggest the potential of pentamidine in anticancer therapies and may provide a basis for developing novel PTPase-targeted therapeutics.

3T3 Cells↗