Breast--Cancer--Treatment.

Model
Digital Document
Publisher
Florida Atlantic University
Description
Studies have shown that tumor cells are susceptible to pharmacological targeting
of their altered glycolytic metabolism with a variety of compounds that result in
apoptosis. One such compound, 3-bromopyruvate (3-BP), has been shown to eradicate
cancer in an animal model. However, no studies have shown whether the apoptotic
fragments resulting from 3-BP treatment have the capacity to elicit an immunogenic cell
death that activates dendritic cells, the primary antigen presenting cell in the immune
system. Immunogenic cell death is critical to eliciting an effective adaptive immune
response that selectively kills additional target cells and generates immunological
memory. We demonstrated that 3-bromopyruvate induced apoptosis in a number of
different murine breast cancer cell lines, including the highly metastatic 4T1 line. The
dying tumor cells stimulated immature dendritic cells (DCs) of the immortal JAWS II
cell line to produce high levels of the pro-inflammatory cytokine IL-12, and increased their expression of key co-stimulatory molecules CD80 and CD86. The activated
dendritic cells showed increased uptake of fragments from dying tumor cells that
correlated with the increased levels of calreticulin on the surface and release of high
group motility box 1 (HMGB1) of the latter following 3-BP treatment. Additionally, the
anti-phagocytic signal CD47 present on breast cancer cells was reduced by treatment with
3-bromopyruvate when compared to the levels on untreated 4T1 cells. 3-BP treated breast
cancer cells were able to activate dendritic cells through TLR4 signaling. Signaling was
dependent on both the expression of surface calreticulin and on the extracellular release
of high mobility group box 1 protein (HMGB1) during the process of immunogenic cell
death. Killing by 3-BP was compared to mitoxantrone and doxorubicin, among the few
chemotherapeutics that induce immunogenic cell death. 3-BP killing was likewise
compared to camptothecin, a compound that fails to induce immunogenic cell death.
Importantly, 3-BP did not markedly decrease the levels of the key peptide presenting
molecule MHC I on DCs that were co-cultivated with dying tumor cells. Treatment of the
highly aggressive triple negative BT-20 human breast cancer cell line with 3-BP also
induced an immunogenic cell death, activating human dendritic cells in vitro.
Model
Digital Document
Publisher
Florida Atlantic University
Description
Extracellular stimuli may influence the M1/M2 phenotypic polarization of
macrophages. We examined M1/M2 biomarkers, phagocytic activity, and tumoricidal
activity in RAW 264.7 mouse macrophages. Macrophages were treated with conditioned
media (CM) from 4T1 breast cancer cells, curcumin, 22-oxacalcitriol, LPS, or a
combination of the previously listed. Arginase activity, a M2 phenotypic biomarker, was
upregulated by the treatment of macrophages with conditioned media. Curcumin, 22-
oxacalcitriol, and LPS partially inhibited RAW 264.7 arginase activity in the presence of
4T1 breast cancer media. 22-oxacalcitriol increased the phagocytic ability of RAW 264.7
macrophages in the presence of M2 polarizing substances produced by the 4T1 breast
cancer cells. Also, LPS increased RAW 264.7 phagocytic ability in the presence of 4T1
breast cancer CM. This study looked at the potential substances that would possibly reverse the M2 tumor promoting macrophage phenotype seen in the breast cancer tumor
environment.
Model
Digital Document
Publisher
Florida Atlantic University
Description
The purpose of this study is to investigate the changes of the pericardial dose at different respiratory phases and statuses in accelerated partial breast irradiation (APBI) using Cyberknife M6™ multileaf collimators (CK-MLC). Anonymous 6 female patient files with respiration gated four-dimensional computed tomography (4DCT) sets, and 6 left breast cancer cases with CT images in free-breathing (FB) and deep inhalation breath-hold (BH) were selected. One CT image set from each patient was planned for APBI in Accuray Multiplan™ 5.2, and respectively compared its pericardial dose with those from CT sets of other respiratory phases. All the comparable CT images were fused in the planning system according to the left chest wall, among which the lung gap anterior to the pericardium varies by the lung expansion. For the purpose of this study, the tumor volume was outlined in the media-lower quadrant of the left breast where this lung gap is relatively small. All the plans in this study met the requirements set by the National Surgical Adjuvant Breast and Bowel Project/Radiation Therapy Oncology Group (NSABP/RTOG), specifically protocol B-39/RTOG 0413. From the comparisons in this investigation, the mean relative pericardial dose of the BH CT group showed significant or 45% (p < 0.01) lower value than that of FB CT group. However, in FB 4DCT group, 3 of 6 cases indicated a meaningful reduction (p < 0.05) in 100% inhalation phase when compared with the mean dose over other phases. The inconsistent pericardial doses were displayed in FB 4DCT group due to minimal changes in the anterior lung gap of the pericardium, when the diaphragmatic breathing was dominant in those patients.