Novel Combinatorial Strategy Using Thermal Inkjet Bioprinting, Chemotherapy, and Radiation on Human Breast Cancer Cells; an In-Vitro Cell Viability Assessment.

BACKGROUND: Breast cancer (BC) continues to have the second highest mortality amongst women in the United States after lung cancer. For 2021, the American Cancer Association predicted 281,550 new invasive breast cancer cases besides 49,290 new cases of non-invasive breast cancer and 43,600 deaths from the metastatic disease. A treatment modality is radiation therapy, which is given for local control as well as palliation of patient symptoms. The initial step of new drug development is in-vitro cell studies, which help describe new drug properties and toxicities. However, these models are not optimal, and better ones have yet to be determined. This study uses bioprinting technology to elucidate the sensitivity of tumor cells to the combination of palbociclib (PD) and letrozole (Let) treatment. We hypothesize that this technology could serve as a model to predict treatment outcomes more efficiently. METHODS: The breast cancer cell lines MCF7 and MDA-MB-231 as well as the normal breast epithelial cell line, MCF-10A, were treated with PD-Let with and without radiotherapy (RT), and cell viability was compared in pairwise fashion for thermally inkjet bioprinted (TIB) and manually seeded (MS) cells. RESULTS: In absence of radiation, the TIB MCF7 cells have 2.5 times higher viability than manually seeded (MS) cells when treated with 100 µM palbociclib and 10 µM letrozole, a 36% higher viability when treated with 50 µM palbociclib and 10 µM letrozole, and an 8% higher viability when treated with 10 µM palbociclib and 10 µM letrozole. With 10 Gy of radiation, TIB cells had a 45% higher survival rate than MS cells at the lowest palbociclib concentration and a 29% higher survival rate at the intermediate palbociclib concentration. Without radiation treatment, at a concentration of 10 µM PD-Let, TIB MDA-MB-231 cells show a 8% higher viability than MS cells when treated with 10 µM PD and 10 µM Let; at higher drug concentrations, the differences disappeared, but some 1.7% of the TIB MDA-MB-231 cells survived exposure to 150 µM of PD + 10 µM letrozole vs. none of the MS cells. These cells are more radiation sensitive than the other cell lines tested and less sensitive to the combo drug treatments. We observed an 18% higher survival of TIB MCF-10A cells without radiation treatment when exposed to 10 µM PD + 10 µM Let but no difference in cell survival between the two groups when radiation was applied. Independent of growth conditions, TIB cells did not show more resistance to radiation treatment than MS cells, but a higher resistance to the combo treatment was observed, which was most pronounced in the MCF-7 cell line. CONCLUSION: Based on these results, we suggest that TIB used in in-vitro models could be a feasible strategy to develop and/or test new anticancer drugs.

Thermal Bioprinting Causes Ample Alterations of Expression of LUCAT1, IL6, CCL26, and NRN1L Genes and Massive Phosphorylation of Critical Oncogenic Drug Resistance Pathways in Breast Cancer Cells.

Bioprinting technology merges engineering and biological fields and together, they possess a great translational potential, which can tremendously impact the future of regenerative medicine and drug discovery. However, the molecular effects elicited by thermal inkjet bioprinting in breast cancer cells remains elusive. Previous studies have suggested that bioprinting can be used to model tissues for drug discovery and pharmacology. We report viability, apoptosis, phosphorylation, and RNA sequence analysis of bioprinted MCF7 breast cancer cells at separate timepoints post-bioprinting. An Annexin A5-FITC apoptosis stain was used in combination with flow cytometry at 2 and 24 h post-bioprinting. Antibody arrays using a Human phospho-MAPK array kit was performed 24 h post-bioprinting. RNA sequence analysis was conducted in samples collected at 2, 7, and 24 h post-bioprinting. The post-bioprinting cell viability averages were 77 and 76% at 24 h and 48 h, with 31 and 64% apoptotic cells at 2 and 24 h after bioprinting. A total of 21 kinases were phosphorylated in the bioprinted cells and 9 were phosphorylated in the manually seeded controls. The RNA seq analysis in the bioprinted cells identified a total of 12,235 genes, of which 9.7% were significantly differentially expressed. Using a ±2-fold change as the cutoff, 266 upregulated and 206 downregulated genes were observed in the bioprinted cells, with the following 5 genes uniquely expressed NRN1L, LUCAT1, IL6, CCL26, and LOC401585. This suggests that thermal inkjet bioprinting is stimulating large scale gene alterations that could potentially be utilized for drug discovery. Moreover, bioprinting activates key pathways implicated in drug resistance, cell motility, proliferation, survival, and differentiation.

Adherence to Adjuvant Aromatase Inhibitor Therapy Among Postmenopausal Hispanic/Latino Women With Breast Cancer.

AIM: The purpose of this study was to determine the level of adherence to adjuvant aromatase inhibitor (AI) therapy and factors associated with non-adherence among Hispanic/Latino women with hormonal receptor-positive breast cancer (BC) treated at an academic center at the American-Mexican border city of El Paso, TX. PATIENTS AND METHODS: Institutional Review Board approval was obtained in this cross-sectional study using the validated Morisky Medication Adherence Scale to assess patient adherence to AI therapy. Patients diagnosed with stage I-III hormonal receptor-positive, human epidermal growth factor receptor 2-negative BC who were on adjuvant AIs therapy were recruited from the Texas Tech University Health Sciences Center El Paso breast clinic. RESULTS: Between September 2017 and August 2018, 122 consecutive patients were enrolled; 119 were analyzed, three were lost to follow up. The mean age was 61.6±9.4 years, and 109 (91.6%) self-identified as Hispanic/Latino. A total of 58% reported an annual income of $15,000 or less. Overall, 40.3% had completed eighth grade or less education, 31.9% high school, and 12% had obtained a technical degree. The majority of patients (56%) had either a medium (45%) or a low level of adherence (11%). High adherence was noted in 44% of participants. Seven (5.6%) patients scored 2 or below on a 4-point scale for intentional adherence, and 18 (13.5%) scored 2 or below on a 4-point scale for unintentional adherence. CONCLUSION: These data suggest that the majority of Hispanic/Latino women with breast cancer have medium or low levels of adherence to therapy with AIs. Factors associated with medium and low adherence were unintentional (forgetfulness), but also included intentional factors, such as avoidance of adverse effects and delays with obtaining refills (cost-related nonadherence).

Single arm phase II study of oral vitamin B12 for the treatment of musculoskeletal symptoms associated with aromatase inhibitors in women with early stage breast cancer.

Breast cancer patients receiving endocrine therapy with aromatase Inhibitors (AIs) often experience musculoskeletal and joint-related side effects. The purpose of this study was to evaluate the effect of Vitamin B12 supplements on musculoskeletal symptoms such as pain and arthralgias induced by AIs and to correlate response with serum and inflammatory biomarkers. Upon receiving approval by the Institutional Review Board (IRB), the majority of the patients consented into the study were treated at the Texas Tech Breast Care Center. Included were patients who had a diagnosis of invasive breast cancer (Stages I-III), and were experiencing significant musculoskeletal symptoms associated to AIs. Only patients with an average pain score ≥ 4, as assessed by the Brief Pain Inventory-Short Form (BPI-SF) questionnaire, were included in the study. Participants received 2500 mcg of sublingual vitamin B12 daily for 90 days. Assessments at baseline and at 3 months included: BPI-SF pain scores, the impact on quality of life determined by Functional Assessment of Cancer Therapy-Endocrine Symptoms (FACT-ES), and correlative serum markers relative to baseline (a pre-post study). A total of forty-one patients were enrolled. Average pain scores were improved by 34% (P < .0001) at 3 months compared to baseline. In addition, a 23% improvement in worst pain was noted (P = .0003). Analysis of the results for the FACT-ES scoring showed improvement on all scales. No significant adverse events were observed. Decrease in pain score was correlated with increased serum B12 levels. This study suggests that Vitamin B12 reduces pain and improves quality of life for patients taking AIs who experienced AI-related musculoskeletal symptoms. If confirmed in large randomized prospective trials, Vitamin B12 would be a safe and cost-effective option for the treatment of AI-related musculoskeletal symptoms.