Peptides genetically selected for NF-κB activation cooperate with oncogene Ras and model carcinogenic role of inflammation.

Chronic inflammation is associated with increased cancer risk. Furthermore, the transcription factor NF-κB, a central regulator of inflammatory responses, is constitutively active in most tumors. To determine whether active NF-κB inherently contributes to malignant transformation, we isolated a set of NF-κB-activating genetic elements and tested their oncogenic potential in rodent cell transformation models. Genetic elements with desired properties were isolated using biologically active selectable peptide technology, which involves functional screening of lentiviral libraries encoding 20 or 50 amino acid-long polypeptides supplemented with endoplasmic reticulum-targeting and oligomerization domains. Twelve NF-κB-activating selectable peptides (NASPs) representing specific fragments of six proteins, none of which was previously associated with NF-κB activation, were isolated from libraries of 200,000 peptides derived from 500 human extracellular proteins. Using selective knockdown of distinct components of the NF-κB pathway, we showed that the isolated NASPs act either via or upstream of TNF receptor-associated factor 6. Transduction of NASPs into mouse and rat embryo fibroblasts did not, in itself, alter their growth. However, when coexpressed with oncogenic Ras (H-Ras(V12)), NASPs allowed rodent fibroblasts to overcome H-Ras(V12)-mediated p53-dependent senescence and acquire a transformed tumorigenic phenotype. Consistent with their ability to cooperate with oncogenic Ras in cell transformation, NASP expression reduced the transactivation activity of p53. This system provides an in vitro model of NF-κB-driven carcinogenesis and suggests that the known carcinogenic effects of inflammation may be at least partially due to NF-κB-mediated abrogation of oncogene-induced senescence.

Pre-clinical activity of targeting the PI3K/Akt/mTOR pathway in Burkitt lymphoma.

Though outcomes for pediatric Burkitt lymphoma (BL) have improved significantly in recent decades with intensive multi-agent chemotherapy and the addition of rituximab, chemotherapy resistance remains a significant impediment to cure following relapse. Activation of the PI3K/AKT pathway has been implicated in Burkitt lymphomagenesis and increased PI3K/AKT activation has been associated with worse outcomes in adults with aggressive B-cell non-Hodgkin lymphoma (B-NHL). Inhibitors of the PI3K/AKT pathway have been approved for the treatment of refractory indolent B-NHL and continue to be investigated for treatment of aggressive B-NHLs. We investigated the activation of the PI3K/AKT pathway in a cell line model of resistant BL and the ability to target this pathway with small molecule inhibitors in BL cell lines. We found that cell lines resistant to rituximab and chemotherapy exhibited increased activation of PI3K/AKT and that inhibition of AKT or PI3K results in in vitro anti-lymphoma activity. To investigate the role of PI3K/AKT activation on the efficacy of cytotoxic chemotherapy, we exposed cells to inhibitors in combination with chemotherapy and noted a synergistic increase in response to chemotherapy. Overall these findings highlight the role of PI3K/AKT in chemotherapy resistance in BL cells and may represent a tractable therapeutic target.

A multicenter performance evaluation of the DPP(®) HIV-1/2 assay for the detection of HIV antibodies in various HIV testing algorithms.

BACKGROUND: Multicenter studies were conducted to evaluate the DPP(®) HIV 1/2 Assay using oral fluid (OF) and fingerstick (FS) specimens in two different countries at the point of care (POC). OBJECTIVE: To evaluate the DPP(®) HIV 1/2 Assay using OF and FS specimens when compared to various worldwide algorithms for the detection of HIV. METHODS: At each testing center, each participant was tested using the DPP HIV 1/2 Assay using OF and FS specimens. Each sample was dispersed into a premeasured buffer in a dropper bottle (DPP(®) SampleTainer™ bottle) and added to the sample well of the device followed by the addition of running buffer to the buffer well of the device. Reference testing was performed according to the National testing algorithm of each Country. RESULTS: Assay sensitivity resulted in ranges of 98.9-100% for OF specimens and 99.8-100% for FS specimens. Assay specificity resulted in ranges of 99.9-100% for OF specimens and 99.5-100% for FS specimens. CONCLUSIONS: Assay sensitivity and specificity obtained for both FS and OF were similar. The DPP HIV 1/2 Assay is highly accurate in detecting antibodies to HIV-1/2 with OF and FS specimens when compared to nationally accepted algorithms. The assay is especially advantageous in that the original sample is collected in a closed vial, eliminating the need for recollection of samples at the POC in the event of an invalid result or assay error upon testing.