The transcriptional landscape of cancer stem-like cell functionality in breast cancer.

BACKGROUND: Cancer stem-like cells (CSCs) have been extensively researched as the primary drivers of therapy resistance and tumor relapse in patients with breast cancer. However, due to lack of specific molecular markers, increased phenotypic plasticity and no clear clinicopathological features, the assessment of CSCs presence and functionality in solid tumors is challenging. While several potential markers, such as CD24/CD44, have been proposed, the extent to which they truly represent the stem cell potential of tumors or merely provide static snapshots is still a subject of controversy. Recent studies have highlighted the crucial role of the tumor microenvironment (TME) in influencing the CSC phenotype in breast cancer. The interplay between the tumor and TME induces significant changes in the cancer cell phenotype, leading to the acquisition of CSC characteristics, therapeutic resistance, and metastatic spread. Simultaneously, CSCs actively shape their microenvironment by evading immune surveillance and attracting stromal cells that support tumor progression. METHODS: In this study, we associated in vitro mammosphere formation assays with bulk tumor microarray profiling and deconvolution algorithms to map CSC functionality and the microenvironmental landscape in a large cohort of 125 breast tumors. RESULTS: We found that the TME score was a significant factor associated with CSC functionality. CSC-rich tumors were characterized by an immune-suppressed TME, while tumors devoid of CSC potential exhibited high immune infiltration and activation of pathways involved in the immune response. Gene expression analysis revealed IFNG, CXCR5, CD40LG, TBX21 and IL2RG to be associated with the CSC phenotype and also displayed prognostic value for patients with breast cancer. CONCLUSION: These results suggest that the characterization of CSCs content and functionality in tumors can be used as an attractive strategy to fine-tune treatments and guide clinical decisions to improve patients therapy response.

The Bioactive Properties of Carotenoids from Lipophilic Sea buckthorn Extract (Hippophae rhamnoides L.) in Breast Cancer Cell Lines.

In women, breast cancer is the most commonly diagnosed cancer (11.7% of total cases) and the leading cause of cancer death (6.9%) worldwide. Bioactive dietary components such as Sea buckthorn berries are known for their high carotenoid content, which has been shown to possess anti-cancer properties. Considering the limited number of studies investigating the bioactive properties of carotenoids in breast cancer, the aim of this study was to investigate the antiproliferative, antioxidant, and proapoptotic properties of saponified lipophilic Sea buckthorn berries extract (LSBE) in two breast cancer cell lines with different phenotypes: T47D (ER+, PR+, HER2-) and BT-549 (ER-, PR-, HER2-). The antiproliferative effects of LSBE were evaluated by an Alamar Blue assay, the extracellular antioxidant capacity was evaluated through DPPH, ABTS, and FRAP assays, the intracellular antioxidant capacity was evaluated through a DCFDA assay, and the apoptosis rate was assessed by flow cytometry. LSBE inhibited the proliferation of breast cancer cells in a concentration-dependent manner, with a mean IC50 of 16 µM. LSBE has proven to be a good antioxidant both at the intracellular level, due to its ability to significantly decrease the ROS levels in both cell lines (p = 0.0279 for T47D, and p = 0.0188 for BT-549), and at the extracellular level, where the ABTS and DPPH inhibition vried between 3.38-56.8%, respectively 5.68-68.65%, and 35.6 mg/L equivalent ascorbic acid/g LSBE were recorded. Based on the results from the antioxidant assays, LSBE was found to have good antioxidant activity due to its rich carotenoid content. The flow cytometry results revealed that LSBE treatment induced significant alterations in late-stage apoptotic cells represented by 80.29% of T47D cells (p = 0.0119), and 40.6% of BT-549 cells (p = 0.0137). Considering the antiproliferative, antioxidant, and proapoptotic properties of the carotenoids from LSBE on breast cancer cells, further studies should investigate whether these bioactive dietary compounds could be used as nutraceuticals in breast cancer therapy.

Circulating Small EVs miRNAs as Predictors of Pathological Response to Neo-Adjuvant Therapy in Breast Cancer Patients.

Neo-adjuvant therapy (NAT) is increasingly used in the clinic for the treatment of breast cancer (BC). Pathological response to NAT has been associated with improved patients' survival; however, the current techniques employed for assessing the tumor response have significant limitations. Small EVs (sEVs)-encapsulated miRNAs have emerged as promising new biomarkers for diagnosis and prediction. Therefore, our study aims to explore the predictive value of these miRNAs for the pathological response to NAT in BC. By employing bioinformatic tools, we selected a set of miRNAs and evaluated their expression in plasma sEVs and BC biopsies. Twelve miRNAs were identified in sEVs, of which, miR-21-5p, 221-3p, 146a-5p and 26a-5p were significantly associated with the Miller-Payne (MP) pathological response to NAT. Moreover, miR-21-5p, 146a-5p, 26a-5p and miR-24-3p were independent as predictors of MP response to NAT. However, the expression of these miRNAs showed no correlation between sEVs and tissue samples, indicating that the mechanisms of miRNA sorting into sEVs still needs to be elucidated. Functional analysis of miRNA target genes and drug interactions revealed that candidate miRNAs and their targets, can be regulated by different NAT regimens. This evidence supports their role in governing the patients' therapy response and highlights their potential use as prediction biomarkers.

The Role of miR-375-3p, miR-210-3p and Let-7e-5p in the Pathological Response of Breast Cancer Patients to Neoadjuvant Therapy.

Background and Objectives: Prediction of response to therapy remains a continuing challenge in treating breast cancer, especially for identifying molecular tissue markers that best characterize resistant tumours. Microribonucleic acids (miRNA), known as master modulators of tumour phenotype, could be helpful candidates for predicting drug resistance. We aimed to assess the association of miR-375-3p, miR-210-3p and let-7e-5p in breast cancer tissues with pathological response to neoadjuvant therapy (NAT) and clinicopathological data. Material and methods: Sixty female patients diagnosed with invasive breast cancer at The Oncology Institute "Ion Chiricuța", Cluj-Napoca, Romania (IOCN) were included in this study. Before patients received any treatment, fresh breast tissue biopsies were collected through core biopsy under echographic guidance and processed for total RNA extraction and miRNA quantification. The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) database was used as an independent external validation cohort. Results: miR-375-3p expression was associated with more differentiated tumours, hormone receptor presence and lymphatic invasion. According to the Miller-Payne system, a higher miR-375-3p expression was calculated for patients that presented with intermediate versus (vs.) no pathological response. Higher miR-210-3p expression was associated with an improved response to NAT in both Miller-Payne and RCB evaluation systems. Several druggable mRNA targets were correlated with miR-375-3p and miR-210-3p expression, with upstream analysis using the IPA knowledge base revealing a list of possible chemical and biological targeting drugs. Regarding let-7e-5p, no significant association was noticed with any of the analysed clinicopathological data. Conclusions: Our results suggest that tumours with higher levels of miR-375-3p are more sensitive to neoadjuvant therapy compared to resistant tumours and that higher miR-210-3p expression in responsive tumours could indicate an excellent pathological response.

Toxoplasma gondii in water buffaloes (Bubalus bubalis) from Romania: what is the importance for public health?

The purpose of our study was to evaluate the prevalence of Toxoplasma gondii infection in autochthonous Carpathian buffaloes from northwestern Romania by serology, PCR techniques, and mouse bioassay. Agreement between MAT and ELISA, correlation between indirect and direct detection methods, and risk factors were evaluated. The apparent overall seroprevalence of T. gondii was 8.1% by MAT and 6.6% by ELISA. The agreement between ELISA and MAT was fair. The apparent seroprevalence was significantly higher in adult buffaloes (12.5%) compared to calves (0.0%) and juveniles (1.9%) by MAT. Most of the positive adult buffaloes detected by MAT had antibodies at a low sera dilution and the highest dilution was 1:768 in a juvenile female (30 months). No viable T. gondii was detected by mouse bioassay, as no T. gondii cyst or DNA was found in the brain of mice and they did not seroconvert. However, T. gondii DNA was detected in two buffaloes: in a 30-month-old male buffalo by qPCR on the diaphragm digest and in a 252-month-old female buffalo by RE nPCR on the mesenteric lymph node. Both animals were negative in MAT and ELISA. The total prevalence of T. gondii by direct detection methods was 2.7%. There was no correlation between indirect and direct detection methods. Since no viable T. gondii was detected in buffaloes, the risk of human infection from buffalo meat is minimal. Buffaloes' biological response to a T. gondii infection appears to be very similar to the response of cattle.

The Impact of miRNA in Colorectal Cancer Progression and Its Liver Metastases.

Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies with a high incidence and mortality rate. An essential challenge in colorectal cancer management is to identify new prognostic factors that could better estimate the evolution and treatment responses of this disease. Considering their role in cancer development, progression and metastasis, miRNAs have become an important class of molecules suitable for cancer biomarkers discovery. We performed a systematic search of studies investigating the role of miRNAs in colorectal progression and liver metastasis published until October 2018. In this review, we present up-to-date information regarding the specific microRNAs involved in CRC development, considering their roles in alteration of Wnt/ßcatenin, EGFR, TGFß and TP53 signaling pathways. We also emphasize the role of miRNAs in controlling the epithelial⁻mesenchymal transition of CRC cells, a process responsible for liver metastasis in a circulating tumor cell-dependent manner. Furthermore, we discuss the role of miRNAs transported by CRC-derived exosomes in mediating liver metastases, by preparing the secondary pre-metastatic niche and in inducing liver carcinogenesis in a Dicer-dependent manner.

Blood Genome-Wide Transcriptional Profiles of HER2 Negative Breast Cancers Patients.

Tumors act systemically to sustain cancer progression, affecting the physiological processes in the host and triggering responses in the blood circulating cells. In this study, we explored blood transcriptional patterns of patients with two subtypes of HER2 negative breast cancers, with different prognosis and therapeutic outcome. Peripheral blood samples from seven healthy female donors and 29 women with breast cancer including 14 triple-negative breast cancers and 15 hormone-dependent breast cancers were evaluated by microarray. We also evaluated the stroma in primary tumors. Transcriptional analysis revealed distinct molecular signatures in the blood of HER2- breast cancer patients according to ER/PR status. Our data showed the implication of immune signaling in both breast cancer subtypes with an enrichment of these processes in the blood of TNBC patients. We observed a significant alteration of "chemokine signaling," "IL-8 signaling," and "communication between innate and adaptive immune cells" pathways in the blood of TNBC patients correlated with an increased inflammation and necrosis in their primary tumors. Overall, our data indicate that the presence of triple-negative breast cancer is associated with an enrichment of altered systemic immune-related pathways, suggesting that immunotherapy could possibly be synergistic to the chemotherapy, to improve the clinical outcome of these patients.

PDGF beta targeting in cervical cancer cells suggest a fine-tuning of compensatory signalling pathways to sustain tumourigenic stimulation.

The platelet-derived growth factor (PDGF) signalling pathway has been reported to play an important role in human cancers by modulating autocrine and paracrine processes such as tumour growth, metastasis and angiogenesis. Several clinical trials document the benefits of targeting this pathway; however, in cervical cancer the role of PDGF signalling in still unclear. In this study, we used siRNA against PDGF beta (PDGFBB) to investigate the cellular and molecular mechanisms of PDGFBB signalling in Ca Ski and HeLa cervical cancer cells. Our results show that PDGFBB inhibition in Ca Ski cells led to rapid alterations of the transcriptional pattern of 579 genes, genes that are known to have antagonistic roles in regulating tumour progression. Concomitantly, with the lack of significant effects on cervical cancer cells proliferation, apoptosis, migration or invasion, these findings suggests that cervical cancer cells shift between compensatory signalling pathways to maintain their behaviour. The observed autocrine effects were limited to cervical cancer cells ability to adhere to an endothelial cell (EC) monolayer. However, by inhibiting PDGFBB on cervical cells, we achieved reduced proliferation of ECs in co-culture settings and cellular aggregation in conditioned media. Because of lack of PDGF receptor expression on ECs, we believe that these effects are a result of indirect PDGFBB paracrine signalling mechanisms. Our results shed some light into the understanding of PDGFBB signalling mechanism in cervical cancer cells, which could be further exploited for the development of synergistic anti-tumour and anti-angiogenic therapeutic strategies.

Regulation of stem cells-related signaling pathways in response to doxorubicin treatment in Hs578T triple-negative breast cancer cells.

Different molecular changes have been previously associated with therapeutic response and recurrent disease, however, the detailed mechanism of action in triple-negative breast cancer subtype remains elusive. In this study, we investigated the cellular and molecular signaling of two claudin-low triple-negative breast cancer cells to doxorubicin and docetaxel treatment. Whole human transcriptomic evaluation was used to identify the subsequent changes in gene expression, while biological effects were measured by means of proliferation and anchorage-independent growth assays. Microarray analysis revealed changes in stem cell-related signaling pathways, suggesting that doxorubicin treatment affects the balance between self-renewal and differentiation. While the treatment reduced the proliferation, aggregation and mammosphere forming ability of stem-like cells derived from Hs578T cell line, stem-like cells derived from MDA-MB-231 cells were not significantly affected. Our results suggest that claudin-low triple-negative breast cancer cells might predominantly alter stem cell-related signaling pathways to promote stem-like cells activity as an innate resistance mechanism to doxorubicin treatment.

Is there a correlation between peripheral blood expression of angiogenic transcriptional factors/receptors and colorectal cancer?

PURPOSE: The aim of this study was to evaluate whether there is a correlation between peripheral blood expression of angiogenic transcriptional factors/receptors and colorectal cancer (CRC). METHODS: Eighty six blood samples collected from patients with CRC (N=42), adenomas and/or hyperplastic polyps(AP, N=30) and individuals without colon pathology (control group/CTR, N=14) were used for this study. Twelve transcription factors and receptors were assessed by qRT-PCR in a case-control study. The molecules with a minimum of 30% differences in gene expression for CRC and AP compared to CTR were then analyzed separately for each sample. Gene expression was evaluated relatively to the CTR after normalization to the large ribosomal protein PO (RPLPO) housekeeping gene, and the differential expression between studied groups was assessed by ANOVA. RESULTS: Seven out of 12 genes presented differences in expression between 10-29% in CRC and/or AP compared to CTR. Considering the selection criteria, we further individually evaluated the levels of expression of 5 genes that had a minimum of 30% expression in the case-control study. Our data showed a significant up-regulation of platelet derived growth factor (PDGF) C in the blood of the patients with CRC compared to CTR (p=0.007). Likewise, clusterin (CLU) was significantly up-regulated both in CRC and AP groups compared to healthy subjects (p=0.01). For VEGFR1, PDGFRA and TGFB1 we didn't find significantly differential expression between any of the studied groups, even if increased levels were observed in both CRC and AP vs CTR. CONCLUSIONS: The results of our study indicated that increased blood level of PDGFC mRNA was associated with the presence of CRC (p=0.007). Additionally, high levels of circulating CLU mRNA were observed in both malignant and benign colorectal pathologies.

Gene expression profiling reveals activation of the FA/BRCA pathway in advanced squamous cervical cancer with intrinsic resistance and therapy failure.

BACKGROUND: Advanced squamous cervical cancer, one of the most commonly diagnosed cancers in women, still remains a major problem in oncology due to treatment failure and distant metastasis. Antitumor therapy failure is due to both intrinsic and acquired resistance; intrinsic resistance is often decisive for treatment response. In this study, we investigated the specific pathways and molecules responsible for baseline therapy failure in locally advanced squamous cervical cancer. METHODS: Twenty-one patients with locally advanced squamous cell carcinoma were enrolled in this study. Primary biopsies harvested prior to therapy were analyzed for whole human gene expression (Agilent) based on the patient's 6 months clinical response. Ingenuity Pathway Analysis was used to investigate the altered molecular function and canonical pathways between the responding and non-responding patients. The microarray results were validated by qRT-PCR and immunohistochemistry. An additional set of 24 formalin-fixed paraffin-embedded cervical cancer samples was used for independent validation of the proteins of interest. RESULTS: A 2859-gene signature was identified to distinguish between responder and non-responder patients. 'DNA Replication, Recombination and Repair' represented one of the most important mechanisms activated in non-responsive cervical tumors, and the 'Role of BRCA1 in DNA Damage Response' was predicted to be the most significantly altered canonical pathway involved in intrinsic resistance (p = 1.86E-04, ratio = 0.262). Immunohistological staining confirmed increased expression of BRCA1, BRIP1, FANCD2 and RAD51 in non-responsive compared with responsive advanced squamous cervical cancer, both in the initial set of 21 cervical cancer samples and the second set of 24 samples. CONCLUSIONS: Our findings suggest that FA/BRCA pathway plays an important role in treatment failure in advanced cervical cancer. The assessment of FANCD2, RAD51, BRCA1 and BRIP1 nuclear proteins could provide important information about the patients at risk for treatment failure.

Influenza A, Influenza B, and SARS-CoV-2 Similarities and Differences - A Focus on Diagnosis.

In late December 2019, the first cases of viral pneumonia caused by an unidentified pathogen were reported in China. Two years later, SARS-CoV-2 was responsible for almost 450 million cases, claiming more than 6 million lives. The COVID-19 pandemic strained the limits of healthcare systems all across the world. Identifying viral RNA through real-time reverse transcription-polymerase chain reaction remains the gold standard in diagnosing SARS-CoV-2 infection. However, equipment cost, availability, and the need for trained personnel limited testing capacity. Through an unprecedented research effort, new diagnostic techniques such as rapid diagnostic testing, isothermal amplification techniques, and next-generation sequencing were developed, enabling accurate and accessible diagnosis. Influenza viruses are responsible for seasonal outbreaks infecting up to a quarter of the human population worldwide. Influenza and SARS-CoV-2 present with flu-like symptoms, making the differential diagnosis challenging solely on clinical presentation. Healthcare systems are likely to be faced with overlapping SARS-CoV-2 and Influenza outbreaks. This review aims to present the similarities and differences of both infections while focusing on the diagnosis. We discuss the clinical presentation of Influenza and SARS-CoV-2 and techniques available for diagnosis. Furthermore, we summarize available data regarding the multiplex diagnostic assay of both viral infections.

Thyroid carcinoma associated with other primary neoplasms, a single center study.

Background and aims: Thyroid carcinoma is the most frequent endocrine malignancy. It develops following a complex interaction of environmental and genetic factors. Its incidence is on the rise mostly due to the frequent diagnosis of microcarcinomas (tumor <1 cm). In most cases, it has very good prognosis and survival rates. The incidence of a second primary malignancy in thyroid cancer patients is higher than in the general population. In this article, we focus on the role of BRAF V600E mutation in the development of other primary neoplasms associated with thyroid carcinoma. Methods: This study was conducted in the department of Nuclear Medicine and Genetics of the "Prof. Dr. Ion Chiricuța" Institute of Oncology of Cluj-Napoca. We evaluated patients with thyroid carcinoma, who were diagnosed and treated for other malignancies such as breast, colorectal, lung cancer and malignant melanoma. In addition, we tested for the BRAF V600E mutation using paraffin samples of patients. Results: We identified 17 patients that had thyroid carcinoma associated with other primary malignancies. Two of the patients included in the study had three associated primary cancers. The time interval between the diagnoses of two primary neoplasms in the same patient was 6.15 years, with a standard deviation (SD) of 5.39 years. The most common primary tumor associated with thyroid carcinoma in this study was breast cancer. We applied genetic testing for the BRAF V600E mutation in 12 patients. The BRAF V600E mutation positivity rate was 26.9% and most of the cancer associations were metachronous (occurring at least 6 months after thyroid cancer). Conclusions: The BRAF V600E mutation is an important prognostic factor in the neoplasms included in this study, but its presence is not a predictive factor for the appearance of a metachronous or synchronous associated primary neoplasm to thyroid cancer.

Predictive Efficacy of MiR-125b-5p, MiR-17-5p, and MiR-185-5p in Liver Metastasis and Chemotherapy Response Among Advanced Stage Colorectal Cancer Patients.

MicroRNAs (miRNAs), a class of small non-coding RNAs represent potential biomarkers for colorectal cancer (CRC). The study hypothesized that miRNAs associated with liver metastases may also contribute to assessing treatment response when associated to plasma exosomes. In this study, we used two sets of biological samples, a collection of tumor tissues harvested from patients with CRC with and without liver metastases, and a collection of plasma from CRC patients with and without response to FOLFOX4/FOLFIRI regimens. We investigated 10 target miRNAs in the tissue of 28 CRC patients and identified miR-125b-5p, miR-17-5p, and miR-185-5p to be associated with liver metastasis. Further, we investigated the three miRNAs at the exosomal level in a plasma collection to test their association with chemotherapy response. Our data suggest that the elevated plasma levels of miR-17-5p and miR-185-5p could be predictive of treatment response. Overexpression of miR-17-5p and underexpression of miR-125b-5p and miR-185-5p in CRC tissue seem to be associated with metastatic potential. On the other hand, an increased expression of miR-125b-5p in plasma exosomes was potentially correlated with a more aggressive CRC phenotype.

Critical Aspects Concerning the Development of a Pooling Approach for SARS-CoV-2 Diagnosis Using Large-Scale PCR Testing.

The primary approach to controlling the spread of the pandemic SARS-CoV-2 is to diagnose and isolate the infected people quickly. Our paper aimed to investigate the efficiency and the reliability of a hierarchical pooling approach for large-scale PCR testing for SARS-CoV-2 diagnosis. To identify the best conditions for the pooling approach for SARS-CoV-2 diagnosis by RT-qPCR, we investigated four manual methods for both RNA extraction and PCR assessment targeting one or more of the RdRp, N, S, and ORF1a genes, by using two PCR devices and an automated flux for SARS-CoV-2 detection. We determined the most efficient and accurate diagnostic assay, taking into account multiple parameters. The optimal pool size calculation included the prevalence of SARS-CoV-2, the assay sensitivity of 95%, an assay specificity of 100%, and a range of pool sizes of 5 to 15 samples. Our investigation revealed that the most efficient and accurate procedure for detecting the SARS-CoV-2 has a detection limit of 2.5 copies/PCR reaction. This pooling approach proved to be efficient and accurate in detecting SARS-CoV-2 for all samples with individual quantification cycle (Cq) values lower than 35, accounting for more than 94% of all positive specimens. Our data could serve as a comprehensive practical guide for SARS-CoV-2 diagnostic centers planning to address such a pooling strategy.

How reliable and useful are angiogenesis blood mediators for prostate cancer diagnosis?

PURPOSE: To evaluate if a blood panel of genes involved in the modulation of the immune system, angiogenesis and tumor development could be used for prostate cancer detection. METHODS: Gene expression profiling of blood samples was assessed with the human angiogenesis RT² Profiler™ pcr array. The study group was divided into training and a testing/validation set. In total, 36 blood samples from 6 heatlhy men, 19 patients with prostate cancer (PCa) and 11 patients with benign prostate pathology (BP) were included in this study. RESULTS: Transcriptional analysis revealed a supervised signature of 28 genes which discriminated the PCa samples from control on the training set (fold regulation [FR] cut off 1.5, p<0.05). This signature was further validated on the testing set. All 28 genes used for this classification were differentially expressed in the new set of 12 PCa samples compared to control but also compared to benign samples (FR cut off 1.5, p<0.05). CONCLUSIONS: Our data could provide new insight into PCa, as a non-invasive predictive tool which along with other factors could improve PCa diagnosis. However, our findings have to be confirmed in a larger cohort of patients before having a clear picture of how this molecular profile will help to increase the accuracy of diagnosis.

In vitro comparative models for canine and human breast cancers.

During the past four decades, an increased number of similarities between canine mammary tumors and human breast cancer have been reported: molecular, histological, morphological, clinical and epidemiological, which lead to comparative oncological studies. One of the most important goals in human and veterinary oncology is to discover potential molecular biomarkers that could detect breast cancer in an early stage and to develop new effective therapies. Recently, cancer cell lines have successfully been used as an in vitro model to study the biology of cancer, to investigate molecular pathways and to test the efficiency of anticancer drugs. Moreover, establishment of an experimental animal model for the study of human breast cancer will improve testing potential anti-cancer therapies and the discovery of effective therapeutic schemes suitable for human clinical trials. In this review, we collected data from previous studies that strengthen the value of canine mammary cancer cell lines as an in vitro model for the study of human breast cancer.

Synergistic Effects Induced by Combined Treatments of Aqueous Extract of Propolis and Venom.

BACKGROUND AND AIMS: Breast cancer is a heterogeneous disease and the leading cause of cancer mortality worldwide. Triple negative breast cancer (TNBC) is considered to be one of the most aggressive breast neoplasia due to failure of chemotherapy response. Thus, there is an urgent need of finding alternative therapies for TNBC. This study was designed to evaluate the synergistic effect induced by propolis and bee venom on luminal (MCF-7) and TNBC (Hs578T) cell lines. METHODS: In order to evaluate the synergistic effect of aqueous extract of propolis and bee venom, we treated in combination two breast cancer cell lines: MCF-7(luminal subtype) and Hs578T (TNBC subtype). RESULTS: Our results indicate that both cell lines exhibited similar sensitivity to the aqueous extract of propolis at a dilution of 0.072-0.09 mg/ml. The results concerning IC50 for bee venom on MCF-7 cells was 1 mg/ml, 20 times higher than 0.05 mg/ml in Hs578T cells. By combining the aqueous extract of propolis with bee venom, we obtained synergistic effects at a higher concentration, which was 5 and 2 times stronger than the two treatments alone. CONCLUSION: Overall, the results from our study indicated that the combination of aqueous extract of propolis and bee venom treatments induced synergistic antiproliferative effects in a concentration-dependent manner in breast cancer cells. Thus we can hypothesize that the combination of honeybee propolis and venom might be involved in signaling pathways that could overcome cells resistance to therapy.