In Situ Vaccination with a TLR 9 Agonist and Local Low Dose Radiation Induces Systemic Responses in Untreated Indolent Lymphoma.
Cancer discovery
Frank, M. J., Reagan, P. M., Bartlett, N. L., Gordon, L. I., Friedberg, J. W., Czerwinski, D. K., Long, S. R., Hoppe, R. T., Janssen, R. S., Candia, A. F., Coffman, R. L., Levy, R.
2018
Abstract
This multicenter phase 1/2 clinical trial evaluated intratumoral SD-101, a TLR9 agonist, and low-dose radiation in patients with untreated indolent lymphoma. 29 enrolled patients received 4 Gy of radiation followed by five weekly intratumoral injections of SD-101 at a single tumor site. No treatment-related grade 4 or serious adverse events occurred. Nearly all patients had tumor reduction at their treated site. More importantly, 24 patients had tumor reduction at their non-treated sites with 5 patients achieving a partial response and one achieving a complete response. Treatment-related increases of CD8+ and CD4+ effector T-cells and decreases of T Follicular Helper and T regulatory cells (Tregs) were observed in the tumor microenvironment. Low pre-treatment levels of CD4+ Tregs, proliferating CD8+ T-cells, and GranzymeB+ CD8+ T-cells were associated with favorable outcomes. Intratumoral SD-101 in combination with low-dose radiation is well tolerated and results in regression of both treated and untreated sites of disease.
View details for PubMedID 30154192
Abstract
B-cell lymphoma is the most common immune system malignancy. TCL1 transgenic mice (TCL1-tg), in which TCL1 is ectopically expressed in mature lymphocytes, develop multiple B- and T-cell leukemia and lymphoma subtypes, supporting an oncogenic role for TCL1 that probably involves AKT and MAPK-ERK signaling pathway augmentation. Additional, largely unknown genetic and epigenetic alterations cooperate with TCL1 during lymphoma progression. We examined DNA methylation patterns in TCL1-tg B-cell tumors to discover tumor-associated epigenetic changes, and identified hypermethylation of sprouty2 (Spry2). Sprouty proteins are context-dependent negative or positive regulators of MAPK-ERK pathway signaling, but their role(s) in B-cell physiology or pathology are unknown. Here we show that repression of Spry2 expression in TCL1-tg mouse and human B-cell lymphomas and cell lines is associated with dense DNA hypermethylation and was reversed by inhibition of DNA methylation. Spry2 expression was induced in normal splenic B cells by CD40/B-cell receptor costimulation and regulated a negative feedback loop that repressed MAPK-ERK signaling and decreased B-cell viability. Conversely, loss of Spry2 function hyperactivated MAPK-ERK signaling and caused increased B-cell proliferation. Combined, these results implicate epigenetic silencing of Spry2 expression in B lymphoma progression and suggest it as a companion lesion to ectopic TCL1 expression in enhancing MAPK-ERK pathway signaling.
View details for DOI 10.1182/blood-2008-05-156943
View details for PubMedID 19147787
View details for PubMedCentralID PMC2656273
Abstract
B-cell lymphomas, the most frequent human immune system malignancies, often contain dysregulated TCL1 oncogene expression. TCL1 transgenic (TCL1-tg) mice develop a spectrum of B-cell malignancies, supporting an oncogenic role for TCL1 in B cells. Our prior global survey of DNA methylation patterns in TCL1-tg B-cell lymphomas identified many lymphoma-specific candidate hypermethylated genes, including Stk39. The Stk39 encoded protein, sterile 20-like-related proline-alanine-rich kinase (SPAK), regulates cell stress responses, and microarray studies identified reduced SPAK expression in metastatic prostate and treatment-resistant breast cancers, suggesting that its loss may have a role in cancer progression. Here we identified DNA hypermethylation and SPAK silencing in TCL1-tg B-cell lymphomas and SPAK silencing without DNA methylation in multiple subtypes of human B-cell lymphomas. SPAK knockdown by shRNA protected B cells from caspase-dependent apoptosis induced by DNA double-strand breaks but not apoptosis in response to osmotic or oxidative cell stressors. Caspase 3 activation by cleavage was impaired with SPAK repression in DNA damaged B cells. Interestingly, c-Jun NH(2)-terminal kinase is potentially activated by SPAK and pharmacological inhibition of c-Jun NH(2)-terminal kinase in SPAK-expressing B cells recapitulated the cell-protective phenotype of SPAK knockdown. Taken together, these data indicate that SPAK loss in B-cell lymphomas promotes increased cell survival with DNA damage and provides a potential mechanism for increased resistance to genotoxic stress in cancer.
View details for DOI 10.2353/ajpath.2009.090091
View details for PubMedID 19717643
View details for PubMedCentralID PMC2751561
Abstract
The dynamic nanomechanical properties of a large number of cells (up to hundreds), measured in parallel with high throughput, are reported. Using NIH 3T3 and HEK 293T fibroblasts and actin depolymerizing drugs, we use a novel nanotechnology to quantify the local viscoelastic properties with applied forces of 20 pN-20 nN, a spatial resolution of <20 nm, and a mechanical dynamic range of several Pa up to ~200 kPa. Our approach utilizes imaging interferometry in combination with reflective, magnetic probes attached to cells. These results indicate that mechanical imaging interferometry is a sensitive and scalable technology for measuring the nanomechanical properties of large arrays of live cells in fluid.
View details for DOI 10.1088/0957-4484/19/23/235101
View details for Web of Science ID 000255662700001
View details for PubMedID 20737027
View details for PubMedCentralID PMC2925287
