P260 Impact of adjuvant radiation therapy photon energy on quality of life after breast conservation therapy: Linear accelerator versus the Cobalt machine (original) (raw)

Radiotherapy-induced miR-223 prevents relapse of breast cancer by targeting the EGF pathway

Oncogene, 2016

In breast cancer (BC) patients, local recurrences often arise in proximity of the surgical scar, suggesting that response to surgery may have a causative role. Radiotherapy (RT) after lumpectomy significantly reduces the risk of recurrence. We investigated the direct effects of surgery and of RT delivered intraoperatively (IORT), by collecting irradiated and non-irradiated breast tissues from BC patients, after tumor removal. These breast tissue specimens have been profiled for their microRNA (miR) expression, in search of differentially expressed miR among patients treated or not with IORT. Our results demonstrate that IORT elicits effects that go beyond the direct killing of residual tumor cells. IORT altered the wound response, inducing the expression of miR-223 in the peritumoral breast tissue. miR-223 downregulated the local expression of epidermal growth factor (EGF), leading to decreased activation of EGF receptor (EGFR) on target cells and, eventually, dampening a positive EGF-EGFR autocrine/paracrine stimulation loop induced by the post-surgical wound-healing response. Accordingly, both RT-induced miR-223 and peri-operative inhibition of EGFR efficiently prevented BC cell growth and reduced recurrence formation in mouse models of BC. Our study uncovers unknown effects of RT delivered on a wounded tissue and prompts to the use of anti-EGFR treatments, in a peri-operative treatment schedule, aimed to timely treat BC patients and restrain recurrence formation.

miR-135b Coordinates Progression of ErbB2-Driven Mammary Carcinomas through Suppression of MID1 and MTCH2

The American Journal of Pathology, 2013

In an attempt to reveal deregulated miRNAs associated with the progression of carcinomas developed in BALB-neuT transgenic mice, we found increased expression of miR-135b during malignancy. Relevantly, we observed that miR-135b is up-regulated in basal or normal-like human breast cancers, and it correlates with patient survival and early metastatization. Therefore, we investigated its biological functions by modulating its expression (up-or down-regulation) in mammary tumor cells. Although no effect was observed on proliferation in cell culture and in orthotopically injected mice, miR-135b was able to control cancer cell stemness in a mammosphere assay, anchorage-independent growth in vitro, and lung cancer cell dissemination in mice after tail vein injections. Focusing on the miR-135b molecular mechanism, we observed that miR-135b controls malignancy via its direct targets, midline 1 (MID1) and mitochondrial carrier homolog 2 (MTCH2), as proved by biochemical and functional rescuing/ phenocopying experiments. Consistently, an anti-correlation between miR-135b and MID1 or MTCH2 was found in human primary tumor samples. In conclusion, our research led us to the identification of miR-135b and its targets, MID1 and MTCH2, as relevant coordinators of mammary gland tumor progression. (Am J Pathol 2013, 182: 2058e2070; http://dx.

MicroRNAs: Are they indicators for prediction of response to radiotherapy in breast cancer?

Journal of Medical Hypotheses and Ideas, 2013

Radiotherapy is one of the most important methods for the treatment of breast cancer. There is great interest in identifying factors that help to predict patient response to radiotherapy. MicroRNAs (miRNAs) are a class of small RNA molecules that regulate gene expression at the post-transcriptional level and play a key role in cellular responses to ionising radiation. Several regulatory proteins participate in breast tumour cell radiosensitivity and there are crosstalks between miRNAs and these proteins at multiple levels. By analysing the relationships between miRNAs and these proteins, we concluded that radioresistant and radiosensitive breast cancer patients might have different patterns of some specific miRNAs. MiRNAs are present in body fluids in a remarkably stable form and can easily be detected and quantified by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). It seems that profiling circulating miRNAs have the potential to be used for the prediction of radiotherapy outcome in breast cancer.

MiR-328 May be Considered as an Oncogene in Human Invasive Breast Carcinoma

Background: The recent investigations have rendered microRNAs (miRs) as a novel biomarker in cancer research. In fact, alteration in miR expression may be associated with tumor suppression, tumorigenesis, metastasis, and poor prognosis in human breast cancer (BC). Objectives: The aim of this clinical experimental study was to measure the miR-328 expression level in breast cancer tissues, at first. Then, we tried to find out any possible correlation between miR-328 and prognostic and predictive biomarkers in BC. Both of these two objectives were investigated for the first time; and we did not find any similar survey measuring the expression level of miR-328 in both tumor and non-tumor breast tissues. This research was conducted in Iran (Ahvaz, Khuzestan), between December 2013 and April 2014. Furthermore, we did not find any previous document investigating the correlation between miR-328 expression level and prognostic factors in BC. Due to the lack of similar studies intending to measure the expression level of miR-328 in tumor and adjacent non-tumor tissues, we decided to carry out a pilot study. Methods: We measured the expression level of miR-328 by Poly (A) real-time PCR based on SYBR Green-I in 28 fresh samples of BC tissues and 28 samples of normal adjacent tissues, including invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), and ductal carcinoma in situ (DCIS). We tried to attribute the results to clinicopathologic features such as status of estrogen and progesterone receptors (ER/PR), HER2/neu (HER2), P53 and also Ki67 labeling (Ki67-LI). Results: The results showed that the miR-328 median level of expression was 0.88 (2-∆∆Ct) (25 th-75 th percentile, 0.07-2.34). It means that the expression level increased in tumor tissues compared to normal adjacent tissues (NATs). However, a statistically significant correlation between the miR-328 median expression level and prognostic factors, including pathologic diagnosis, age, and also the status of ER, PR, HER2, and Ki67-LI was not observed (P > 0.05). Conclusions: Therefore, it might be possible to consider miR-328 as an oncogene; but not necessarily an oncomiR, in human BC.

Relationship between Circulating and Tissue microRNAs in a Murine Model of Breast Cancer

PLoS ONE, 2012

MiRNAs are key regulators of tumorigenesis that are aberrantly expressed in the circulation and tissue of patients with cancer. The aim of this study was to determine whether miRNA dysregulation in the circulation reflected similar changes in tumour tissue. Athymic nude mice (n = 20) received either a mammary fat pad (n = 8, MFP), or subcutaneous (n = 7, SC) injection of MDA-MB-231 cells. Controls received no tumour cells (n = 5). Tumour volume was monitored weekly and blood sampling performed at weeks 1, 3 and 6 following tumour induction (total n = 60). Animals were sacrificed at week 6 and tumour tissue (n = 15), lungs (n = 20) and enlarged lymph nodes (n = 3) harvested. MicroRNAs were extracted from all samples (n = 98) and relative expression quantified using RQ-PCR. MiR-221 expression was significantly increased in tumour compared to healthy tissue (p,0.001). MiR-10b expression was significantly higher in MFP compared to SC tumours (p,0.05), with the highest levels detected in diseased lymph nodes (p,0.05). MiR-10b was undetectable in the circulation, with no significant change in circulating miR-221 expression detected during disease progression. MiR-195 and miR-497 were significantly decreased in tumour tissue (p,0.05), and also in the circulation of animals 3 weeks following tumour induction (p,0.05). At both tissue and circulating level, a positive correlation was observed between miR-497 and miR-195 (r = 0.61, p,0.001; r = 0.41, p,0.01 respectively). This study highlights the distinct roles of miRNAs in circulation and tissue. It also implicates miRNAs in disease dissemination and progression, which may be important in systemic therapy and biomarker development.

Deregulation of cancer-related miRNAs is a common event in both benign and malignant human breast tumors

Carcinogenesis, 2014

MicroRNAs (miRNAs) are endogenous non-coding RNAs, which play an essential role in the regulation of gene expression during carcinogenesis. The role of miRNAs in breast cancer has been thoroughly investigated, and although many miRNAs are identified as cancer related, little is known about their involvement in benign tumors. In this study, we investigated miRNA expression profiles in the two most common types of human benign tumors (fibroadenom a/fibroadenomatosis) and in malignant breast tumors and explored their role as oncomirs and tumor suppressor miRNAs. Here, we identified 33 miRNAs with similar deregulated expression in both benign and malignant tumors compared with the expression levels of those in normal tissue, including breast cancer-related miRNAs such as let-7, miR-21 and miR-155. Additionally, messenger RNA (mRNA) expression profiles were obtained for some of the same samples. Using integrated mRNA/miRNA expression analysis, we observed that overexpression of certain miRNAs co-occurred with a significant downregulation of their candidate target mRNAs in both benign and malignant tumors. In support of these findings, in vitro functional screening of the downregulated miRNAs in nonmalignant and breast cancer cell lines identified several possible tumor suppressor miRNAs, including miR-193b, miR-193a-3p, miR-126, miR-134, miR-132, miR-486-5p, miR-886-3p, miR-195 and miR-497, showing reduced growth when re-expressed in cancer cells. The finding of deregulated expression of oncomirs and tumor suppressor miRNAs in benign breast tumors is intriguing, indicating that they may play a role in proliferation. A role of cancer-related miRNAs in the early phases of carcinogenesis and malignant transformation can, therefore, not be ruled out.

Expression Changes of Some miRNAs Patterns (miR-124a, miR-137, miR-373) in Patients with Invasive Breast Cancer Before and After Neoadjuvant Chemotherapy

2021

Background: Dysregulated miRNA expression has been found in nearly all the stages of cancer process compared to normal tissue. Certain miRNAs expression level is closely related to the histopathological parameters and molecular subtypes of breast cancer (BC) as well as the response to treatment and prognosis.Methods: This prospective research has evaluated the level of expression of 5 miRNAs (miR-124a, miR-137, miR-34a, miR-155, miR-373) in the primary tumor before and after chemotherapy in patients with operable BC. The patients received 2-4 cycles neoadjuvant chemotherapy (NACT) and then underwent surgery – mastectomy or breast conservation with axillary lymph node dissection. Assessment of all mRNAs was analyzed in selected pathology specimens obtained during the biopsy and the targeted area taken by the surgery. Results: A total of 34 patients were treated between February 2016 and December 2017 with median age of 53 years (23 – 75). 70.6% were HR-positive and 29.4% were HR-nega...

Preliminary Study: Prominent miRNAs of Breast Malignant Tissues Compared to Normal Tissues in Turkish Patients with Breast Cancer

Anticancer research, 2015

miRNA involvement has been observed in almost every type of cancer, including breast cancer. The etiology of abnormal expression of miRNAs in cancer is still not clearly understood. In order to obtain insight into miRNA de-regulation in breast cancer, we analyzed expression levels of five breast cancer-related miRNAs, miRNA21, miRNA155, miRNA19a, miRNA17-5p and let7a miRNA, in both malignant and neighboring non-tumoral paraffin-embedded tissues of 47 patients with invasive ductal breast cancer. The targeted miRNAs, and a reference snRNA, U6, were analyzed by real-time polymerase chain reaction. let7a Levels were significantly lower in patients with lymphatic invasion than in those without (p=0.047). miR21 was down-regulated in 93.3% of patients with necrosis [p=0.017 (Fisher's exact test (FE))], while at least one oncogenic miRNA was up-regulated in 87.3% of the patients with invasive ductal carcinoma [p=0.009 (FE)]. In addition, tumor-suppressor miRNA was down-regulated or unal...

Differential response of normal and transformed mammary epithelial cells to combined treatment of anti-miR-21 and radiation

Purpose: MicroRNA miR-21 has emerged as a therapeutic target in the treatment of breast cancer. This study was designed to compare the responses of breast cancer cells and non-transformed breast epithelial cells to a combined regimen of miR-21 inhibition and radiation. Materials and methods: The MDA-MB-361 (breast cancer) and MCF-10A (non-transformed mammary epithelial) cell lines were used for the comparison in this in vitro study. The stable knockdown of miR-21 was performed by using lentiviral approach. The response of the cells was monitored 4, 24 and 48 h after the irradiation with 0.25 and 2.5 Gy, using sham-irradiated cells as controls. The response of the cells was established by performing various functional assayscell viability and cell attachment, clonogenic survival, cell cycle analysis and 3D microtissue formation. Results: The knockdown of miR-21 induced significant increase in apoptosis and growth delay in MDA-MB-361 cancer cells compared to non-transformed MCF-10A cells. After combined radiation and anti-miR-21 treatment, MDA-MB-361 cells show reduced cell growth and viability what is presented in their inability to form colonies. MCF-10A cells were not as sensitive to the combined treatment and that has also been confirmed with colony forming assay. Conclusions: Cellular response to a combined treatment of anti-miR-21 and radiation is different between cancer and non-cancer cells which highly support the idea of linking miR-21 inhibitor and radiation treatment in the future therapeutic approaches for breast cancer.

Impact of Tumour Epithelial Subtype on Circulating microRNAs in Breast Cancer Patients

PLoS ONE, 2014

While a range of miRNAs have been shown to be dysregulated in the circulation of patients with breast cancer, little is known about the relationship between circulating levels and tumour characteristics. The aim of this study was to analyse alterations in circulating miRNA expression during tumour progression in a murine model of breast cancer, and to detemine the clinical relevance of identified miRNAs at both tissue and circulating level in patient samples. Athymic nude mice received a subcutaneous or mammary fat pad injection of MDA-MB-231 cells. Blood sampling was performed at weeks 1, 3 and 6 following tumour induction, and microRNA extracted. MicroRNA microArray analysis was performed comparing samples harvested at week 1 to those collected at week 6 from the same animals. Significantly altered miRNAs were validated across all murine samples by RQ-PCR (n = 45). Three miRNAs of interest were then quantified in the circulation(n = 166) and tissue (n = 100) of breast cancer patients and healthy control individuals. MicroArray-based analysis of murine blood samples revealed levels of 77 circulating microRNAs to be changed during disease progression, with 44 demonstrating changes .2-fold. Validation across all samples revealed miR-138 to be significantly elevated in the circulation of animals during disease development, with miR-191 and miR-106a levels significantly decreased. Analysis of patient tissue and blood samples revealed miR-138 to be significantly up-regulated in the circulation of patients with breast cancer, with no change observed in the tissue setting. While not significantly changed overall in breast cancer patients compared to controls, circulating miR-106a and miR-191 were significantly decreased in patients with basal breast cancer. In tissue, both miRNAs were significantly elevated in breast cancer compared to normal breast tissue. The data demonstrates an impact of tumour epithelial subtype on circulating levels of miRNAs, and highlights divergent miRNA profiles between tissue and blood samples from breast cancer patients.