Breast cancer: Actual methods of treatment and future trends

ER+ Breast Cancer Strongly Depends on MCL-1 and BCL-xL Anti-Apoptotic Proteins

Breast cancer is the most frequent type of cancer and the major cause of mortality in women. The rapid development of various therapeutic options has led to the improvement of treatment outcomes; nevertheless, one-third of estrogen receptor (ER)-positive patients relapse due to cancer cell acquired resistance. Here, we use dynamic BH3 profiling (DBP), a functional predictive assay that measures net changes in apoptotic priming, to find new effective treatments for ER+ breast cancer. We observed anti-apoptotic adaptations upon treatment that pointed to metronomic therapeutic combinations to enhance cytotoxicity and avoid resistance. Indeed, we found that the anti-apoptotic proteins BCL-xL and MCL-1 are crucial for ER+ breast cancer cells resistance to therapy, as they exert a dual inhibition of the pro-apoptotic protein BIM and compensate for each other. In addition, we identified the AKT inhibitor ipatasertib and two BH3 mimetics targeting these anti-apoptotic proteins, S63845 and A-1331852, as new potential therapies for this type of cancer. Therefore, we postulate the sequential inhibition of both proteins using BH3 mimetics as a new treatment option for refractory and relapsed ER+ breast cancer tumors.

Outcomes in volume replacement and volume displacement techniques in oncoplastic breast conserving surgery: A systematic review

INTRODUCTION

Volume Replacement (VR-OBCS) and Volume Displacement Oncoplastic Breast Conserving Surgery (VD-OBCS) are commonly used in the management of breast cancer. Many studies summarize the individual postoperative outcomes of these two procedures; however, there is a lack of research that compares outcomes of these approaches. This review summarizes the available VR and VD-OBCS literature in terms of oncological, cosmetic, and clinical outcomes.

METHODS

An online literature search (MEDLINE, EMBASE, PubMed, and CINAHL) was performed. Studies were included if they were written in English, had more than 10 adult (18+) female patients who underwent VR-OBCS or VD-OBCS, and reported at least one well-described oncological, clinical, or cosmetic outcome RESULTS: Thirty-three studies (26 VR-OBCS and 7 VD-OBCS) were included in this review; VR-OBCS studies were separated based on the use of latissimus dorsi (LD) flaps. Studies utilizing VR-OBCS with LD flaps reported the highest rate of all oncological outcomes; VR-OBCS studies without LD flaps reported the lowest. Rates of hematoma, seroma, and wound dehiscence were highest in VR-OBCS with LD flaps; partial flap loss and fat necrosis were highest in VR-OBCS without LD flaps and infection was highest in VD-OBCS studies. Inconsistencies in methodology (cosmetic outcome measures, outcome definitions, and time horizons) were found in all procedural groups.

CONCLUSION

Differences in outcomes for both OBCS procedures may be due to the heterogeneity of patient populations. "Doers" and "Users" of breast oncoplastic research should consider tumor size, laterality of tumor, breast size, measurement scales, and defensible time horizons before the application of a study's conclusions.

The impact of health symptoms on health-related quality of life in early-stage breast cancer survivors

Purpose

In breast cancer patients, treatment-related health symptoms can occur that may affect their health-related quality of life (HRQoL). This study aimed to determine the impact of health symptoms on HRQoL in breast cancer patients up to 5 years after diagnosis.

Methods

Females surgically treated for early-stage breast cancer diagnosed between 2012 and 2016 (n = 876) were selected from the Netherlands Cancer Registry and invited for a survey about current health symptoms (‘Symptoms and Perceptions questionnaire’, SaP) and HRQoL (‘EORTC-QLQ-C30’). From the latter, functioning and global health were included. Mean scores were compared to norm population scores (T test). Multivariable linear regression analyses were performed to determine the association between health symptoms and global health and functioning.

Results

404 patients (46%) responded. The median age was 62.2 ± 10.9 years. Respondents had significantly lower mean scores for role, cognitive, emotional, and social functioning than the general population. The most frequently reported health symptoms were musculoskeletal (including pain/complaints in lower/upper extremities/back/neck; 71%) and central nervous system symptoms (including concentration impairment, dizziness, neuralgia; 66%), and fatigue (63%). While most symptoms affected functioning, irrespective of time since diagnosis, especially fatigue, musculoskeletal, central nervous system, and gastrointestinal symptoms were significantly associated (p < 0.05) with lower functioning.

Conclusions

The majority of health symptoms that occur after breast cancer treatment were associated with lower functioning of patients in daily life. This paper urges healthcare providers to support breast cancer patients in alleviating or coping with health symptoms, even years after end of treatment, to improve their functioning.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05433-3) contains supplementary material, which is available to authorized users.

Accelerated partial breast irradiation with perioperative multicatheter interstitial brachytherapy-A feasibility study

PURPOSE

To assess the feasibility of high-dose-rate perioperative multicatheter interstitial brachytherapy to deliver accelerated partial breast irradiation (APBI) in selected patients with early breast cancer.

METHODS AND MATERIALS

Perioperative multicatheter interstitial brachytherapy for APBI has been used at our department since 2012 for patients with low-risk breast cancer. Interstitial catheters were inserted perioperatively via hollow needles immediately following tumorectomy with sentinel node biopsy. APBI started on Day 6 after surgery. The prescribed dose was 34 Gy (10 fractions of 3.4 Gy bid). Hormonal therapy was prescribed in all cases.

RESULTS

Between June 2012 and December 2017, 125 patients were scheduled for APBI. Of these, APBI was not performed in 12 patients (9.6%) due to adverse prognostic factors identified on the definitive biopsy. We observed wound dehiscence in 2/113 cases (1.8%), inflammatory complications requiring antibiotics in 7/113 cases (6.2%), transient Grade I radiodermatitis in 6/113 patients (4.4%), and seroma which resolved spontaneously in 3/113 patients (2.7%). With median followup of 39 months (range 3.3-75.3) no relapses were observed. No late complications in Radiation Therapy Oncology Group Grade 3 or higher were documented. Cosmetic outcome in patients with followup > 2 years was excellent or good in 92%.

CONCLUSION

Our preliminary results show that the perioperative multicatheter interstitial high-dose-rate brachytherapy for APBI in selected patients with early breast cancer is feasible. This treatment schedule reduces treatment duration, spares the patients of repeated anesthesia, and enables precise application of the afterloading tubes under direct visual control.

Wound fluids affect miR-21, miR-155 and miR-221 expression in breast cancer cell lines, and this effect is partially abrogated by intraoperative radiation therapy treatment

Breast cancer is the most common malignant disease occurring in women. Conservative breast cancer surgery followed by radiation therapy is currently the standard treatment for this type of cancer. The majority of metastases occur within the scar, which initiated a series of studies. As a result, clinical trials aimed to assess whether localized radiotherapy, as intraoperative radiotherapy (IORT), may more effective in inhibiting the formation of local recurrence compared with the standard postoperative whole breast radiotherapy. The present study determined the role of postoperative wound fluids (WFs) from patients diagnosed with breast cancer subsequent to breast conserving surgery or breast conserving surgery followed by IORT on the expression of three microRNAs (miRNAs), consisting of miR-21, miR-155 and miR-221, in distinct breast cancer cell lines that represent the general subtypes of breast cancer. It was determined that the miRNAs responsible for breast cancer progression, induction of tumorigenesis and enrichment of the cancer stem cell phenotype, which is responsible for resistance to tumor therapy, were highly upregulated in the human epidermal growth factor receptor 2-positive breast cancer SK-BR-3 cell line following stimulation with WFs. It is worth emphasizing, that those changes were more significant in WFs collected from patients after surgery alone. The BT-549 cell line showed altered expression only of miR-155 following incubation with WFs. Notably, this change was not associated with IORT. Additionally, it was indicated that both WFs and RT-WF strongly downregulated the expression of miR-21, miR-155 and miR-221 in basal/epithelial and luminal subtypes of breast cancer. It was concluded that the present study contributes to an increased understanding of the role of surgical WFs and IORT treatment in the regulation of miRNA expression. This may enable the development of the current knowledge of breast cancer biology subsequent to IORT treatment and substantially to improve the therapy in the future.

Practical issues regarding angular and energy response in in vivo intraoperative electron radiotherapy dosimetry

AIM

To estimate angular response deviation of MOSFETs in the realm of intraoperative electron radiotherapy (IOERT), review their energy dependence, and propose unambiguous names for detector rotations.

BACKGROUND

MOSFETs have been used in IOERT. Movement of the detector, namely rotations, can spoil results.

MATERIALS AND METHODS

We propose yaw, pitch, and roll to name the three possible rotations in space, as these unequivocally name aircraft rotations. Reinforced mobile MOSFETs (model TN-502RDM-H) and an Elekta Precise linear accelerator were used. Two detectors were placed in air for the angular response study and the whole set of five detectors was calibrated as usual to evaluate energy dependence.

RESULTS

The maximum readout was obtained with a roll of 90° and 4 MeV. With regard to pitch movement, a substantial drop in readout was achieved at 90°. Significant overresponse was measured at 315° with 4 MeV and at 45° with 15 MeV. Energy response is not different for the following groups of energies: 4, 6, and 9 MeV; and 12 MeV, 15 MeV, and 18 MeV.

CONCLUSIONS

Our proposal to name MOSFET rotations solves the problem of defining sensor orientations. Angular response could explain lower than expected results when the tip of the detector is lifted due to inadvertent movements. MOSFETs energy response is independent of several energies and differs by a maximum of 3.4% when dependent. This can limit dosimetry errors and makes it possible to calibrate the detectors only once for each group of energies, which saves time and optimizes lifespan of MOSFETs.

Pharmacokinetics and Pharmacodynamics in Breast Cancer Animal Models

The study of pharmacokinetics (PK) and pharmacodynamics (PD) in cancer drug discovery and development is often paired and described in reciprocal terms, where PK is the analysis of the change in drug concentration with time and PD is the analysis of the biological effects of the drug at various concentrations over different time courses. While PK is defined by how a compound is absorbed, distributed, metabolized, and eliminated, PD refers to the measure of a compound's ability to interact with its intended target, leading to a biologic effect. Recent advances in anti-breast cancer drug discovery have resulted in several new drugs, but there is still a high attrition rate during clinical development. One reason for this failure is attributed to inappropriate correlation between the PK and PD parameters and subsequent extrapolation to human subjects. In this chapter, we describe the protocols of PK and PD studies in breast cancer models to assess the efficacy of an anti-breast cancer compound, noting the types and endpoints employed, and explain why it is important to link PK and PD in order to establish and evaluate dose/concentration-response relationships and subsequently describe and predict the effect-time courses for a given drug dose.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

BACKGROUND

The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context.

METHODS

We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI).

FINDINGS

Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6-58·8) of global deaths and 41·2% (39·8-42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa.

INTERPRETATION

Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden.

FUNDING

Bill & Melinda Gates Foundation.

Effect of surgical wound fluids after intraoperative electron radiotherapy on the cancer stem cell phenotype in a panel of human breast cancer cell lines

The wound healing process after surgery alters the area surrounding the original tumor and around the scar, and the modified microenvironment is more favorable for tumor recurrence. Intraoperative radiotherapy (IORT) is one of the more novel strategies in breast cancer (BC) treatment. Irradiation during surgery has effects on the tumor microenvironment, abrogating the proliferative cascade induced by surgical wound healing. The aim of the present study was to determine the effect of surgical wound fluids from IOERT treatment (RT-WF) compared with wound fluids from conservative-breast surgery only (WF) on the cancer stem cell phenotype in a panel of BC cell lines. Post-operative wound fluids were derived from patients with BC who underwent a tumor resection (quadrantectomy) plus intraoperative electron radiotherapy using a single dose of ≤10 Gy on the tumor bed and surrounding tissues, or from those who underwent a tumor resection without IOERT. Cell lines were incubated with 10% wound fluids, and after 4 days, the cluster of differentiation (CD)44⁺/CD24^-/low phenotype and aldehyde dehydrogenase 1 (ALDH1) activity were determined by flow cytometry. The two types of fluid each affected the CD44⁺/CD24^-/low phenotype. The results varied markedly between each cell line, even for the same histological subtypes. RT-WF decreased the CD44⁺/CD24^-/low populations in the basal-like BT-549 and MDA-MB-468 cell lines, whereas in the luminal type MCF7 cell line, the two fluids inhibited these populations. The HER-OE subtypes harbored a minimal CD44⁺/CD24^-/low population, but the growth of SK-BR-3 was stimulated by the two post-operative fluids. WF exhibited a stronger effect on ALDH1 activity compared with RT-WF. The stimulatory effect was dependent on the histological subtype of the cell line and the strongest dependence was observed in luminal subtypes characterized by low dehydrogenase activity in the control group. The present results enable a better understanding of the mechanism of recurrence and metastases following BC surgery. With respect to histological phenotype, its effect on tumor progression, either local or systemic, strongly suggests the requirement for further research and clinical validation.

The appropriate axillary procedure after a positive sentinel node in breast cancer patients: the "Hôpital Tenon" score revisited. A two-institution study

INTRODUCTION

Until recently, completion ALND has been considered the standard of care after a positive SN in breast cancer patients. However, most patients will not display further axillary involvement. The Tenon score is a simple nomogram that can be used intraoperatively to avoid completion ALND in low-risk patients. We aimed at validating the Tenon score on a SN-positive patient sample that had been preoperatively selected using axillary US examination.

PATIENTS AND METHOD

We used a retrospective analysis of our bicentric database that included 246 breast cancer patients with a positive SN. We calculated sensitivity, specificity, as well as positive and negative predictive values for each cut-off point. ROCs were constructed and corresponding AUC values were calculated as a measure of discriminative capacity.

RESULTS

At least one non-SN was positive in 52 patients (21.1 %). 118 patients (48 %) had a score up to 5. Among them, three had at least one positive non-SN. NPV was 97.5 %. Using that threshold, the ROCs analysis showed an AUC of 0.822 (95 % CI 0.764-0.880).

CONCLUSION

Use of preoperative axillary US examination led to a modification of the proposed Tenon cut-off value from 3.5 to 5 to attain good predictive power for non-SN status. Straightforward intraoperative use of the Tenon score may be considered an advantage over other available nomograms.

Pre and post radiotherapy serum oxidant/antioxidant status in breast cancer patients: Impact of age, BMI and clinical stage of the disease

AIM

In this study the effects of radiation therapy (RT) on serum oxidant/antioxidant status in breast cancer patients and the impact of age, BMI and clinical stage of the disease on the aforementioned variables were investigated.

BACKGROUND

RT that is used for cancer treatment is dependent on the production of reactive oxygen species.

MATERIALS AND METHODS

Eighty patients with breast cancer participated in this study and received RT at a dose of 50 Gy for 5 weeks. Blood samples were obtained in one day before and after the end of RT. Serum status of malondialdehyde (MDA), total antioxidant status (TAS), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were analyzed by spectrophotometry or ELISA and selenium (Se) level were analyzed by atomic absorption spectrometry. Paired t-test was used for comparing pre and post radiotherapy data.

RESULTS

Before and after the radiotherapy, a significant increase in MDA level was observed, while a significant decrease in GPx activity, SOD, TAS and Se levels were found (p < 0.05). The level of the CAT enzyme had no significant changes (p = 0.568). The results showed some changes in the status of TAS, SOD and GPx which are associated with age, BMI and clinical stage of the disease.

CONCLUSION

It seems that RT would have the potential to cause variations in the status of antioxidant/oxidant system. Although, some changes in variables were observed by sub-classification of the age, BMI and the disease stage, but it seems that these changes are not necessarily dependent to them.

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

BACKGROUND

The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution.

METHODS

Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol.

FINDINGS

All risks combined account for 57·2% (95% uncertainty interval [UI] 55·8-58·5) of deaths and 41·6% (40·1-43·0) of DALYs. Risks quantified account for 87·9% (86·5-89·3) of cardiovascular disease DALYs, ranging to a low of 0% for neonatal disorders and neglected tropical diseases and malaria. In terms of global DALYs in 2013, six risks or clusters of risks each caused more than 5% of DALYs: dietary risks accounting for 11·3 million deaths and 241·4 million DALYs, high systolic blood pressure for 10·4 million deaths and 208·1 million DALYs, child and maternal malnutrition for 1·7 million deaths and 176·9 million DALYs, tobacco smoke for 6·1 million deaths and 143·5 million DALYs, air pollution for 5·5 million deaths and 141·5 million DALYs, and high BMI for 4·4 million deaths and 134·0 million DALYs. Risk factor patterns vary across regions and countries and with time. In sub-Saharan Africa, the leading risk factors are child and maternal malnutrition, unsafe sex, and unsafe water, sanitation, and handwashing. In women, in nearly all countries in the Americas, north Africa, and the Middle East, and in many other high-income countries, high BMI is the leading risk factor, with high systolic blood pressure as the leading risk in most of Central and Eastern Europe and south and east Asia. For men, high systolic blood pressure or tobacco use are the leading risks in nearly all high-income countries, in north Africa and the Middle East, Europe, and Asia. For men and women, unsafe sex is the leading risk in a corridor from Kenya to South Africa.

INTERPRETATION

Behavioural, environmental and occupational, and metabolic risks can explain half of global mortality and more than one-third of global DALYs providing many opportunities for prevention. Of the larger risks, the attributable burden of high BMI has increased in the past 23 years. In view of the prominence of behavioural risk factors, behavioural and social science research on interventions for these risks should be strengthened. Many prevention and primary care policy options are available now to act on key risks.

FUNDING

Bill & Melinda Gates Foundation.

Immunosuppression of breast cancer cells mediated by transforming growth factor-β in exosomes from cancer cells

Exosomes derived from tumor cells are essential for processes involved in tumor progression, including angiogenesis, tumor cell proliferation and immunoregulation. In addition, exosome secretion may contribute to the mechanisms of hypoxia-induced angiogenesis and metastasis of tumors. In the present study, as it is one of the most common cancers in females, breast cancer, cell lines were cultured under hypoxic (1% O₂) and normoxic conditions to evaluate the effects of hypoxia on exosome production. Under hypoxic conditions an increase in the number of exosomes in the medium, determined by CD63 immunoblotting, was observed. Application of these exosomes to T cells revealed that they were able to suppress T cell proliferation. As transforming growth factor-β (TGF-β), interleukin-10, and prostaglandin E2 are important factors in the mediation of T cell suppression, the exosomes were subsequently treated with antibodies against these three factors. The results revealed that anti-TGF-β was capable of ameliorating the immunosuppressive effects of exosomes. These data demonstrate that hypoxia enhances the secretion of exosomes by breast cancer cells, which acts to suppress T cell proliferation via TGF-β. The findings have significant implications for understanding the underlying mechanisms of immunosuppression in tumor microenvironments, and for the potential development of cancer therapies.

MicroRNA-29a inhibits cell migration and invasion by targeting Roundabout 1 in breast cancer cells

Epithelial ovarian cancer (EOC) remains a major gynecological problem, with a poor 5-year-survival rate due to distant metastases. The identification of microRNAs (miRNAs) may provide a novel avenue for diagnostic and treatment regimens for EOC. Several miRNAs have been reported to be involved in the progression of EOC, among which miRNA (miR)-137 has been observed to be downregulated in the ovarian tissues of patients with EOC. However, the functions of miR-137 in EOC cell apoptosis, migration and invasion remain to be elucidated. In the present study, the expression of miR-137 was measured in clinical ovarian cancer specimens and cell lines using reverse transcription-quantitative polymerase chain reaction. The role of miR-137 in the growth and survival of the SKOV3 human ovarian cancer cell line was determined using several in vitro approaches and in nude mouse models. The results demonstrated that the expression of miR-137 was downregulated in the ovarian cancer specimens and cell lines. It was also observed that enforced expression of miR-137 in the EOC cell lines decreased cell proliferation, clonogenicity, migration and invasion, and induced G1 arrest and cell apoptosis in vitro. Notably, the enforced expression of miR-137 suppressed tumor growth in the nude mice models. These findings suggested that miR-137 may act as a tumor suppressor and be used as a potential therapeutic agent for the treatment of EOC.

miRNA - Therapeutic tool in breast cancer? Where are we now?

OBJECTIVE

The aim of this study was to review the current knowledge about involvement of microRNAs in breast cancer, and their potential in the clinic, published in scientific journals searched in Pubmed/Medline database until March 2014.

RESULTS

MicroRNAs (miRNAs) are a family of 21-25 nucleotide small RNAs molecules. Currently, it is well known that miRNA plays a key role in all cellular processes of the organism including tumour initiation and progression. Many studies have shown that circulating miRNAs are attractive, easily detectable tumour biomarkers. Breast cancer is one of the most common cancers in the world. It is clinically established that different subtypes may respond differently to therapies, give metastases and present drug resistance. MicroRNAs have a potential as diagnostic, prognostic and therapeutic tools in breast cancer.

CONCLUSION

Molecular knowledge is crucial for choosing the most effective therapy for individual patients. MicroRNAs holds a great potential in anticancer therapy.