3,3′-Diindolylmethane and paclitaxel act synergistically to promote apoptosis in HER2/neu human breast cancer cells

Background. HER2/neu positive breast tumors are difficult to treat. About 25 to 30% of invasive breast tumors overexpress the HER2/neu oncogene. These tumors are aggressive and become resistant to chemotherapeutic drugs. 3,3′-diindolylmethane (DIM), the active metabolite of indole-3-carbinol, a naturally occurring compound found in cruciferous vegetables, has been found to have anti-cancer properties in both humans and animals. DIM has been shown to induce cell cycle arrest and apoptosis in animal breast cancer models. Because HER2/neu overexpression confers resistance to paclitaxel, and DIM has anti-tumor effects, we hypothesized that DIM will enhance the cytotoxic effects of paclitaxel, a common taxane drug, on human Her2/neu breast cancer cells by potentiating its effect on cell cycle and stimulating apoptosis. Methods. The MDA-MB-435eB1 human Her2/neu breast cancer cells were treated with varying concentrations of DIM and paclitaxel. The cells were analyzed at different time points (24, 48, and 72 h). Proliferation was measured by a commercial cell proliferation assay (Promega Procheck Assay). Cell-cycle analysis and apoptosis were determined by flow cytometry. Western blot analysis was performed on to determine the effect of DIM and/or paclitaxel on the proteins involved in apoptosis, and epidermal growth factor-induced activation of HER2/neu and ERK1/2 signaling proteins. Results. Both DIM and paclitaxel exhibited time and concentration dependent inhibition of cell proliferation. TUNEL assay indicated that the combination also increased the number of apoptotic cells more than either agent alone. The presence of cleaved poly (ADPRibose) polymerase (PARP) significantly increased in the combination treatment, whereas Bcl-2 is decreased. DIM alone decreased the activation of the Her2/neu receptor; the combination decreased the activation of ERK1/ERK2. Conclusions. DIM in combination with paclitaxel synergistically inhibits growth of Her2/neu human breast cancer cells through G2M phase cell-cycle arrest and induction of apoptosis/necrosis. The Her2/neu receptor and its downstream signaling protein ERK1/2 appear to be involved in DIM’s affect on cell growth and differentiation, whereas apoptosis appears to be mediated through the mitochondrial pathway (Bcl-2/ PARP). It appears DIM, a naturally occurring, nontoxic compound, may be a beneficial addition to a traditional (taxane-based) chemotherapy regimen

Surgical Patterns of Care in Patients with Invasive Breast Cancer Treated with Neoadjuvant Systemic Therapy and Breast Magnetic Resonance Imaging: Results of a Secondary Analysis of TBCRC 017

Neoadjuvant chemotherapy (NCT) down-stages advanced primary tumors, with magnetic resonance imaging (MRI) being the most sensitive imaging predictor of response. However, the impact of MRI evaluation on surgical treatment decisions in the neoadjuvant setting has not been well described. We report surgical patterns of care across 8 National Cancer Institute comprehensive cancer centers in women receiving both NCT and MRI to evaluate the impact of MRI findings on surgical planning

Novel Methylated Biomarkers and a Robust Assay to Detect Circulating Tumor DNA in Metastatic Breast Cancer

The ability to consistently detect cell-free tumor-specific DNA in peripheral blood of patients with metastatic breast cancer provides the opportunity to detect changes in tumor burden and to monitor response to treatment. We developed cMethDNA, a quantitative multiplexed methylation-specific PCR assay for a panel of ten genes, consisting of novel and known breast cancer hypermethylated markers identified by mining our previously reported study of DNA methylation patterns in breast tissue (103 cancer, 21 normal on the Illumina HumanMethylation27 Beadchip) and then validating the 10-gene panel in a TCGA breast cancer methylome database. For cMethDNA, a fixed physiological level (50 copies) of artificially constructed, standard non-human reference DNA specific for each gene is introduced into in a constant volume of serum (300 μl) prior to purification of the DNA, facilitating a sensitive, specific, robust and quantitative assay of tumor DNA, with broad dynamic range. Cancer-specific methylated DNA was detected in Training (28 normal, 24 cancer) and Test (27 normal, 33 cancer) sets of recurrent Stage 4 patient sera with a sensitivity of 91% and a specificity of 96% in the test set. In a pilot study, cMethDNA assay faithfully reflected patient response to chemotherapy (N = 29). A core methylation signature present in the primary breast cancer was retained in serum and metastatic tissues collected at autopsy 2–11 years after diagnosis of the disease. Together, our data suggest that the cMethDNA assay can detect advanced breast cancer, and monitor tumor burden and treatment response in women with metastatic breast cancer

Correction: Shen, J.; et al. Biological Aging Marker p16INK4a in T Cells and Breast Cancer Risk. Cancers 2020, 12, 3122

The authors wish to make the following corrections to this paper [...

Biological Aging Marker p16INK4a in T Cells and Breast Cancer Risk

Prior research has demonstrated that altered telomere length, a well-known marker for biological aging, is associated with various types of human cancer. However, whether such association extends to additional hallmarks of biological aging, including cellular senescence, has not been determined yet. In this two-stage study, we assessed the association between p16INK4a mRNA expression in T cells, a marker of cellular senescence, and breast cancer risk. The discovery stage included 352 breast cancer patients and 324 healthy controls. p16INK4a mRNA expression was significantly higher in individuals who were older, Black, and had family history of cancer than their counterparts in both cases and controls. p16INK4a mRNA expression also differed by marital status, annual income, and smoking status in cases. In the discovery stage, we found that increased p16INK4a mRNA expression was associated with 1.40-fold increased risk of breast cancer (OR = 1.40; 95%CI: 1.21, 1.68; p < 0.001). A marginally significant association was further observed in the validation stage with 47 cases and 48 controls using pre-diagnostic samples (OR = 1.28; 95%CI: 0.98, 2.97; p = 0.053). In addition, we found that p16INK4a mRNA expression was higher in tumors with selected aggressive characteristics (e.g., poorly differentiated and large tumors) than their counterparts. In summary, our results demonstrate that higher p16INK4a mRNA expression in T cells is a risk factor for breast cancer and further support the role of biological aging in the etiology of breast cancer development. Novelty and Impact Statements: The results from this study provide evidence that cellular senescence, a process of biological aging, plays a role in breast cancer etiology. In addition, our results also support that social demographics may modify cellular senescence and biological aging

The impact of Onco type DX® recurrence score of paraffin-embedded core biopsy tissues in predicting response to neoadjuvant chemotherapy in women with breast cancer

BACKGROUND: Oncotype DX® test is beneficial in predicting recurrence free survival in estrogen receptor positive (ER+) breast cancer. Ability of the assay to predict response to neoadjuvant chemotherapy (NCT) is less well-studied. OBJECTIVE: We hypothesize a positive association between the Oncotype DX® recurrence score (RS) and the percentage tumor response (%TR) after NCT. METHODS: Pre-therapy RS was measured on core biopsies from 60 patients with ER+, HER2.. invasive breast cancer (IBC) who then received NCT. Pre-therapy tumor size was measured using imaging. %TR, partial response (PR; 50%), pathologic complete response (PCR) and breast conserving surgery (BCS) rates were measured. RESULTS: Median RS was 20 (2 69). Median %TR was 42 (0 97)%. PR was observed in 43% of patients. There was no association between %TR and pre-NCT tumor size, age, Nottingham score or nodal status (p 0:05). No statistically significant association with %TR was seen with RS as a categorical or continuous variable (p = 0:21 and 0.7, respectively). Response to NCT improved as ER (p = 0:02) by RT-PCR decreased. Lower ER expression by IHC correlated with response (p = 0:03). CONCLUSIONS: In patients with ER+ IBC receiving NCT, RS did not predict response to NCT using %TR. The benefit of the assay prior to NCT requires further study