Exploring the time-dependent regulatory potential of microRNAs in breast cancer cells treated with proteasome inhibitors.

PURPOSE: Breast cancer (BrCa) is a predominant type of cancer with a disparate molecular nature. MicroRNAs (miRNAs) have emerged as promising key players in the regulation of pathological processes in BrCa. Proteasome inhibitors (PIs) emerged as promising anticancer agents for several human malignancies, including BrCa, inhibiting the function of the proteasome. Aiming to shed light on the miRNA regulatory effect in BrCa after treatment with PIs, we used two PIs, namely bortezomib and carfilzomib. MATERIALS AND METHODS: Four BrCa cell lines of distinct molecular subtypes were treated with these PIs. Cell viability and IC50 concentrations were determined. Total RNA was extracted, polyadenylated, and reversely transcribed. Next, the levels of specific miRNAs with a significant role in BrCa were determined using relative quantification, and their regulatory effect was assessed. RESULTS: High heterogeneity was discovered in the levels of miRNAs in the four cell lines, after treatment. The miRNA levels fluctuate with distinct patterns, in 24, 48, or 72 hours. Interestingly, miR-1-3p, miR-421-3p, and miR-765-3p appear as key molecules, as they were found deregulated, in almost all combinations of cell lines and PIs. In the SK-BR-3 cell line, the majority of the miRNAs were significantly downregulated in treated compared to untreated cells, with miR-21-5p being the only one upregulated. Finally, various significant biological processes, molecular functions, and pathways were predicted to be affected. CONCLUSIONS: The diversity of pathways predicted to be affected by the diversity in miRNA expression after treatment with PIs paves the way for the recognition of new regulatory axes in BrCa.

A Real-world Study of Everolimus Plus Aromatase Inhibitor in Hormone Receptor-positive, HER2-negative Advanced Breast Cancer.

BACKGROUND/AIM: Everolimus in combination with exemestane was shown to offer benefit versus exemestane monotherapy in hormone receptor (HR)-positive, HER2-negative advanced breast cancer patients who progressed after aromatase inhibitor (AI) therapy. PATIENTS AND METHODS: The medical records of metastatic breast cancer patients, treated with everolimus, were retrospectively reviewed to generate real life safety and efficacy data. RESULTS: Sixty-eight percent of the patients had received chemotherapy (for early or metastatic disease) and 26% had received chemotherapy for metastatic disease. Among the 25 included patients, the most common adverse events were fatigue, neutropenia, epistaxis, stomatitis, and pneumonitis. Toxicity led to treatment discontinuation in 3 patients (12%). The median progression-free survival (PFS) was 7 months (95%CI=3.5-10.5). With a median follow-up of 73.3 months, the median overall survival was not reached. Twenty-five percent of the patients had received prior therapy with CDK4/6 inhibitors. Median PFS was significantly shorter in this subgroup (p=0.025). There was also a trend towards a longer PFS in patients with grade 3 breast cancer (p=0.085) and in patients receiving everolimus as first-line treatment (p=0.081). Some long responses were noted, with four patients exhibiting a PFS >5 years. CONCLUSION: These real-life data show that everolimus in combination with AI in patients with HER2-negative, HR-positive advanced breast cancer is an effective treatment with an acceptable toxicity profile.

Characteristics and outcomes of cancer patients who develop pulmonary embolism: A cross-sectional study.

Pulmonary embolism (PE), along with deep vein thrombosis, are collectively known as venous thromboembolism (VTE). Predisposing factors for PE include post-operative conditions, pregnancy, cancer and an advanced age; of note, a number of genetic mutations have been found to be associated with an increased risk of PE. The association between cancer and VTE is well-established, and cancer patients present a higher risk of a thrombotic event compared to the general population. In addition, PE is a significant cause of morbidity and mortality among cancer patients. The aim of the present study was to illustrate the clinical characteristics, laboratory findings, radiology features and outcomes of cancer patients who developed PE, collected from an anticancer hospital. For this purpose, adult cancer patients diagnosed with PE by imaging with computed tomography pulmonary angiography were enrolled. The following data were recorded: Demographics, comorbidities, type of cancer, time interval between cancer diagnosis and PE occurrence, the type of therapy received and the presence of metastases, clinical signs and symptoms, predisposing factors for PE development, laboratory data, radiological findings, electrocardiography findings, and the type of therapy received for PE and outcomes in a follow-up period of 6 months. In total, 60 cancer patients were enrolled. The majority of the cancer patients were males. The most common type of cancer observed was lung cancer. The majority of cases of PE occurred within the first year from the time of cancer diagnosis, while the majority of patients had already developed metastases. In addition, the majority of cancer patients had received chemotherapy over the past month, while they were not receiving anticoagulants and had central obstruction. A large proportion of patients had asymptomatic PE. The in-hospital mortality rate was 13.3% and no relapse or mortality were observed during the follow-up period. The present study demonstrates that elevated levels of lactic acid and an increased platelet count, as well as low serum levels of carcinoembryonic antigen, albumin and D-dimer, may be potential biomarkers for asymptomatic PE among cancer patients.

Human kallikrein-related peptidase 12 (KLK12) splice variants discriminate benign from cancerous breast tumors.

OBJECTIVES: As kallikrein-related peptidase 12 (KLK12) has been implicated in the cancer progression and alternative splicing plays significant role in this disease, the aim of this study was to examine the expression profile and the clinical impact of the KLK12 splice variants in breast cancer. DESIGN AND METHODS: Total RNA was isolated and reverse transcripted from 141 tissues. Afterwards, quantitative real-time PCR were conducted, followed by the performance of the comparative CT (2-ΔΔCT) method for relative quantification, whilst their correlation with the clinicopathological features of breast malignancies were assessed by statistical analysis. RESULTS: Both KLK12sv1/2 and KLK12sv3 showed higher expression in non-cancerous than in cancerous samples. KLKsv1/2 (P = 0.001) upregulated and KLK12sv3 (P < 0.001) downregulated in the malignant compared to the benign tumors and their discriminative ability was verified by ROC curve analysis. Moreover, KLK12sv3 was associated with grade (P = 0.012) and hormonal receptor status (P = 0.001). Furthermore, Kaplan-Meier and Cox regression analyses showed that patients with positive KLK12sv1/2 and KLK12sv3 levels presented a significantly longer disease-free survival (P = 0.014 and P = 0.013, respectively) and overall survival (P = 0.062 and P = 0.004, respectively). CONCLUSIONS: Our results demonstrate the discriminative value of KLK12sv1/2 and KLK12sv3 between benign and malignant breast tumors as well as their potential favorable prognostic significance in breast adenocarcinoma.