Exosomes in Colorectal Cancer: From Physiology to Clinical Applications.

Exosomes are nanosized vesicles that have been found to be involved in many diseases. Exosomes can mediate communication between cells in a variety of ways. Certain types of mediators derived from cancer cells can play a crucial role in the development of this pathology, promoting tumor growth, invasion, metastasis, angiogenesis, and immunomodulation. Exosomes in the bloodstream show promise as a future tool for detecting cancer at an early stage. The sensitivity and specificity of clinical exosome biomarkers need to be enhanced. Knowledge of exosomes is not only important for understanding the significance of cancer progression but also for providing clinicians with useful information for the diagnosis, treatment, and discovery of methods to prevent cancer from recurring. The widespread adoption of diagnostic tools based on exosomes may revolutionize cancer diagnosis and treatment. Tumor metastasis, chemoresistance, and immunity are all aided by exosomes. A potential new approach to cancer therapy involves preventing metastasis by inhibiting miRNA intracellular signaling and blocking the formation of pre-metastatic niches. For colorectal patients, exosomes represent a promising area of investigation for improving the diagnosis, treatment, and management. Reported data demonstrate that the serum expression level of certain exosomal miRNA is significantly higher in primary colorectal cancer patients. The present review discusses mechanisms and clinical implications of exosomes in colorectal cancer.

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.

Nanoscale delivery systems for microRNAs in cancer therapy.

Concomitant with advances in research regarding the role of miRNAs in sustaining carcinogenesis, major concerns about their delivery options for anticancer therapies have been raised. The answer to this problem may come from the world of nanoparticles such as liposomes, exosomes, polymers, dendrimers, mesoporous silica nanoparticles, quantum dots and metal-based nanoparticles which have been proved as versatile and valuable vehicles for many biomolecules including miRNAs. In another train of thoughts, the general scheme of miRNA modulation consists in inhibition of oncomiRNA expression and restoration of tumor suppressor ones. The codelivery of two miRNAs or miRNAs in combination with chemotherapeutics or small molecules was also proposed. The present review presents the latest advancements in miRNA delivery based on nanoparticle-related strategies.

Vitamin D Supplementation: Oxidative Stress Modulation in a Mouse Model of Ovalbumin-Induced Acute Asthmatic Airway Inflammation.

Asthma oxidative stress disturbances seem to enable supplementary proinflammatory pathways, thus contributing to disease development and severity. The current study analyzed the impact of two types of oral vitamin D (VD) supplementation regimens on the redox balance using a murine model of acute ovalbumin-induced (OVA-induced) asthmatic inflammation. The experimental prevention group received a long-term daily dose of 50 µg/kg (total dose of 1300 µg/kg), whereas the rescue group underwent a short-term daily dose of 100 µg/kg (total dose of 400 µg/kg). The following oxidative stress parameters were analyzed in serum, bronchoalveolar lavage fluid (BALF) and lung tissue homogenate (LTH): total oxidative status, total antioxidant response, oxidative stress index, malondialdehyde and total thiols. Results showed that VD significantly reduced oxidative forces and increased the antioxidant capacity in the serum and LTH of treated mice. There was no statistically significant difference between the two types of VD supplementation. VD also exhibited an anti-inflammatory effect in all treated mice, reducing nitric oxide formation in serum and the expression of nuclear factor kappa B p65 in the lung. In conclusion, VD supplementation seems to exhibit a protective role in oxidative stress processes related to OVA-induced acute airway inflammation.

Recent advancements in the study of breast cancer exosomes as mediators of intratumoral communication.

Breast cancer is a heterogeneous disease, with a morbidity rate of 27.8% and a mortality rate of 15% among women population worldwide. Understanding how this cancer develops and the mechanisms behind tumor progression and chemoresistance is of utmost importance. Exosomes mediate communication in a population of heterogeneous tumoral cells. They have a cargo composed of oncogenes and oncomiRs which change the transcriptomic scenario of their targeted cells and activate numerous tumor-promoting signaling pathways. Exosomes secreted by breast cancer cells lead to enhanced cell proliferation, replicative immortality, angiogenesis, invasion, migration, and chemoresistance. Studying exosomes from this perspective offers more in depth understanding of breast malignancy and may aid in the future development of early diagnostic, prognostic and therapeutic options. We present the latest findings in this area and offer practical solutions which may further stimulate the much-needed research of exosome in breast cancer.

New Insights in Gene Expression Alteration as Effect of Paclitaxel Drug Resistance in Triple Negative Breast Cancer Cells.

BACKGROUND/AIMS: Triple negative breast cancer (TNBC) is a highly aggressive form of cancer which lacks targeted therapy options. Thus, TNBC patients have poor outcomes and a decreased survival rate than patients with other types of breast cancers. Due to the lack of surface receptors, TNBC needs a comprehensive investigation to provide more information regarding patient's therapy, as well as to understand the way how to counteract drug resistance mechanisms. Nowadays, chemotherapy remains an unsolved issue which rise a lot of questions in oncology field. METHODS: In this article, we investigated the implication of paclitaxel in TNBC cell lines after a prolong administration, after 12, respectively 24 passages followed by evaluation of morphological alteration, mutational pattern by next generation sequencing and the altered gene expression pattern by microarray technology and validation by qRT-PCR of the resistance to therapy relevant genes. RESULTS: Using functional assays, we showed that paclitaxel exhibits antiproliferative activity on Hs578T/Pax and MDA-MB-231/Pax demonstrating the activation of cell death mechanisms. Confocal microscopy revealed significant modifications which occur in the morphological structure with a disruption of the actin-filaments and also mitotic catastrophe. The presence of these nuclear alterations is due to some modifications at the cellular and molecular levels. Important alterations at the transcriptomic and genomic levels were observed from this a common drug resistance signature (IL-6, CXCL8, VEGFA, EGR1, PTGS2 and TRIB1) for both cell lines at 24 passages was discovered. Also, an important mutation (TP53) linked with drug response was identified. CONCLUSION: These results might be used to furnish novel biomarkers in TNBC, as well as to find a strategy to counteract the resistance to therapy in order to increase survival rate and to enhance the prognosis of patients with TNBC.

Current and New Predictors for Treatment Response in Metastatic Colorectal Cancer. The Role of Circulating miRNAs as Biomarkers.

Colorectal cancer (CRC) is the third most frequently diagnosed cancer in the world. More than half of all CRC patients will eventually develop metastases and require treatment accordingly, but few validated predictive factors for response to systemic treatments exist. In order to ascertain which patients benefit from specific treatments, there is a strong need for new and reliable biomarkers. We conducted a comprehensive search using the PUBMED database, up to December 2019, in order to identify relevant studies on predictive biomarkers for treatment response in metastatic CRC. We will herein present the currently used and potential biomarkers for treatment response and bring up-to-date knowledge on the role of circulating microRNAs, associated with chemotherapy and targeted therapy regimens used in metastatic CRC treatment. Molecular, tumor-related, disease-related, clinical, and laboratory predictive markers for treatment response were identified, mostly proposed, with few validated. Several circulating microRNAs have already proven their role of prediction for treatment response in CRC, but future clinical studies are needed to confirm their role as biomarkers across large cohorts of patients.

Identification of Core Genes Involved in the Progression of Cervical Cancer Using an Integrative mRNA Analysis.

In spite of being a preventable disease, cervical cancer (CC) remains at high incidence, and it has a significant mortality rate. Although hijacking of the host cellular pathway is fundamental for developing a better understanding of the human papillomavirus (HPV) pathogenesis, a major obstacle is identifying the central molecular targets involved in HPV-driven CC. The aim of this study is to investigate transcriptomic patterns of HPV-infected and normal tissues to identify novel prognostic markers. Analyses of functional enrichment and interaction networks reveal that altered genes are mainly involved in cell cycle, DNA damage, and regulated cell-to-cell signaling. Analysis of The Cancer Genome Atlas (TCGA) data has suggested that patients with unfavorable prognostics are more likely to have DNA repair defects attributed, in most cases, to the presence of HPV. However, further studies are needed to fully unravel the molecular mechanisms of such genes involved in CC.

Beyond Conventional: The New Horizon of Anti-Angiogenic microRNAs in Non-Small Cell Lung Cancer Therapy.

GLOBOCAN 2018 identified lung cancer as the leading oncological pathology in terms of incidence and mortality rates. Angiogenesis is a key adaptive mechanism of numerous malignancies that promotes metastatic spread in view of the dependency of cancer cells on nutrients and oxygen, favoring invasion. Limitation of the angiogenic process could significantly hamper the disease advancement through starvation of the primary tumor and impairment of metastatic spread. This review explores the basic molecular mechanisms of non-small cell lung cancer (NSCLC) angiogenesis, and discusses the influences of the key proangiogenic factors-the vascular endothelial growth factor-A (VEGF-A), basic fibroblast growth factor (FGF2), several matrix metalloproteinases (MMPs-MMP-2, MMP-7, MMP-9) and hypoxia-and the therapeutic implications of microRNAs (miRNAs, miRs) throughout the entire process, while also providing critical reviews of a number of microRNAs, with a focus on miR-126, miR-182, miR-155, miR-21 and let-7b. Finally, current conventional NSCLC anti-angiogenics-bevacizumab, ramucirumab and nintedanib-are briefly summarized through the lens of evidence-based medicine.

MiRNAs roles in the diagnosis, prognosis and treatment of colorectal cancer.

Introduction: The liver is the main location for metastasization in stage IV colorectal cancers. Areas covered: This review intends to comprehensively present the most important studies conducted in the past few years concerning the role of miRNAs in colorectal cancer liver metastases, trying to clarify some aspects regarding tumor biology and favorite liver metastasization site. Expert commentary: Recent advances in tissue and serum RNA extraction has considerably improved the field of microRNAs studies. These molecules known to play a crucial role in the metastatic stage indicate a starting point in the development of clinical biomarkers with a possible role in the stratification of high-risk patients for adequate treatment.

Inhibitory Effect of CAPE and Kaempferol in Colon Cancer Cell Lines-Possible Implications in New Therapeutic Strategies.

BACKGROUND: Phytochemicals are natural compounds synthesized as secondary metabolites in plants and represent an important source of molecules with therapeutic applications. Attention is accorded to their potential in anti-cancer therapies as single agents or adjuvant treatment. Herby, we evaluated the in vitro effects of a panel of natural compounds with focus on caffeic acid phenethyl ester (CAPE) and Kaempferol for the treatment of human colon cancer. METHODS: We exposed two human colon cancer cell lines, RKO and HCT-116, followed by functional examination of cell viability, cell proliferation and invasion, cell cycle, apoptosis, and autophagy. Modifications in gene expression were investigated through microarray and detection of existing mutations and finding of new ones was done with the help of Next Generation Sequencing (NGS). RESULTS: Both CAPE and Kaempferol inhibit cell proliferation, motility and invasion, and stimulate apoptosis and autophagy, concomitant with modifications in coding and noncoding genes' expression. Moreover, there are pathogenic mutations that are no longer found upon treatment with CAPE and Kaempferol. CONCLUSIONS: Our findings indicate that CAPE and Kaempferol have the ability to negatively influence the development and advancement of colon cancer in vitro by specifically altering the cells at the molecular level; this activity can be exploited in possible adjuvant therapies once the optimal dose concentration with minimal side effects but with cancer inhibitory activity is set in vivo.

Gene Expression Patterns Unveil New Insights in Papillary Thyroid Cancer.

Background and objectives: Papillary thyroid carcinoma is the most frequent variety of all malignant endocrine tumors. It represents a heterogeneous malignancy with various clinical outcomes, emphasizing the need to identify powerful biomarkers with clinical relevance. Materials and Methods: Available gene expression data (level 3) for thyroid cancers were downloaded from the Cancer Genome Atlas (TCGA), followed by bioinformatic analyses performed on the data set. Results: Based on gene expression analysis, we were able to identify common and specific gene signatures for the three main types of papillary thyroid carcinoma (classical, follicular variant, and tall-cell). The survival rate was not significantly different among the main subtypes, but we were able to identify a biological adhesion signature with impact in patient prognostic. Conclusions: Taken together, the gene expression signature and particular adhesion signature, along with ITGA10 and MSLN in particular, could be used as a prognostic tool with important clinical relevance.

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.

Follicle-stimulating hormone receptors: A comparison of commercially-available monoclonal and polyclonal antibodies as immunohistochemical markers for cancer research.

PURPOSE: In recent studies, follicle-stimulating hormone receptors (FSHRs) have been reported in a wide range of malignant and benign tumours, depending on the type of antibody used. Using two commercially available antibodies (monoclonal and polyclonal), the current research attempted to demonstrate the usefulness of each antibody for investigating FSHRs in non-canonical tissues. Further, we sought to replicate the results of a major study which demonstrated the presence of FSHRs in the endothelial cells of perineoplastic blood vessels. METHODS: Immunostaining was performed on 16 surgically excised benign and malignant tumor tissue samples using both monoclonal and polyclonal anti-FSHR antibodies. RESULTS: Positive staining of FSHRs was heterogeneous among the tissue samples used for analysis, and was confirmed not only in tumour and endothelial cells of perineoplastic blood vessels, but also in benign and normal cells. Based on our findings, FSHR staining using a polyclonal antibody appeared to be highly sensitive, but with a relatively low specificity. Comparatively, immunoreactivity using a monoclonal antibody appeared to show high specificity, but relatively low sensitivity. Although the selected monoclonal antibody for FSHRs seemed to be more specific than the polyclonal variant, neither exhibited a high overall specificity. Neither of the antibodies assessed in the present research could replicate the results of the aforementioned major study. CONCLUSIONS: In conclusion, neither of the two commercially available antibodies seem to be appropriate for investigating FSHRs in non-canonical tissues and, by extension, their role in carcinogenesis.

Non-Hodgkin lymphoma in Romania: a single-centre experience.

Epidemiologic studies of non-Hodgkin lymphoma (NHL) in Eastern Europe are scarce in the literature. We report the experience of the "Ion Chiricuta" Institute of Oncology in Cluj-Napoca (IOCN), Romania, in the diagnosis and outcome of patients with NHL. We studied 184 consecutive NHL patients diagnosed in the Pathology Department of IOCN during the years 2004-2006. We also obtained epidemiological data from the Northwestern (NW) Cancer Registry. In the IOCN series, the most common lymphoma subtype was diffuse large B-cell lymphoma (43.5%), followed by the chronic lymphocytic leukaemia/small lymphocytic lymphoma (21.2%). T-cell lymphomas represented a small proportion (8.2%). The median age of the patients was 57 years, with a male-to-female ratio of 0.94. Patients with indolent B-cell lymphomas had the best overall survival, whereas those with mantle cell lymphoma had the worst survival. The NW Cancer Registry data showed that the occurrence of NHL in the NW region of Romania was higher in men [world age-standardized incidence rate/100 000 (ASR)-5.9; 95% CI 5.1-6.6] than in women (ASR-4.1; 95% CI 3.5-4.7) with age-standardized male-to-female ratio of 1.44 (p = 0.038). Chronic lymphocytic leukaemia/small lymphocytic lymphoma was the most common NHL in the NW region of Romania, accounting for 43% of all cases, followed by diffuse large B-cell lymphoma (36%). The 5-year, age-standardized cumulative relative survival for NHL in the County of Cluj in NW Romania, for the period of 2006-2010, was 51.4%, with 58.4% survival for men and 43.2% for women. Additional studies of NHL in Eastern Europe are needed. Copyright © 2015 John Wiley & Sons, Ltd.

Tumor infiltrating lymphocytes as a prognostic factor in malignant melanoma. Review of the literature.

Malignant melanoma represents the major cause of mortality among skin cancers, with increasing incidence and mortality rates worldwide. Despite the numerous public health campaigns and the efforts undertaken in the last decade regarding the establishment of a rapid diagnostic and an efficient treatment for these patients, the long-term prognosis has not been significantly improved. Thus, numerous studies were conducted in order to establish a more accurate prognosis, tumor infiltrating lymphocytes (TILs) being considered in many studies as independent prognostic factors of lymph node metastasis and overall survival in patients with melanoma. Moreover, immunotherapy has been intensively studied and evolved in recent times, and represents a promising treatment option for patients with advanced stage (metastatic) malignant melanoma. In this review article, we provided a literature overview on the histological classification, the history and the essential role of TILs, as well as the implications of regulatory T (Treg) cells and FOX P3 transcription factor in malignant melanoma.

The prognostic role of Skp2 and the tumor suppressor protein p27 in colorectal cancer.

PURPOSE: This study aimed at exploring the role of Skp2, p27 and Cks1 expression as prognostic factors for colorectal cancer (CRC) patients, and to identify a correlation between their expression and the cell proliferation marker Ki67. METHODS: We conducted a retrospective study on 130 patients with CRC treated with surgery and adjuvant treatment at the Oncology Institute Cluj-Napoca between 2006- 2010. The Skp2, p27, Cks1 and Ki67 immunoexpression was grouped from 1 to 4, according to percents of tumor cells with nuclear reactivity. Their correlation with overall survival (OS), recurrence free survival (RFS) and with the classical histopathological prognostic factors were analyzed. All patients had 5-year follow-up. RESULTS: The majority of patients had locally advanced TNM stages II and III. More than a half of the tumors had low immunoexpression of Skp2 and Cks1, and high and moderate p27 and Ki67 expression. Skp2 overexpression negatively influenced the p27 (p=0.002). Both OS and RFS were significantly higher in patients with moderate and high expression of p27 (p=0.005). Skp2 and Cks1 overexpression negatively influenced OS and RFS. Skp2 overexpression positively correlated with TNM stage (p<0.001), node capsular invasion (p=0.002) and lymphovascular invasion (p=0.042). Ki67 expression did not correlate with Skp2 (p=0.88), Cks1 (p=0.67) and p27 (p=0.40), neither with OS (p=0.841) and RFS (p=0.84). CONCLUSIONS: The most important prognostic factor was the Skp2 overexpression. It was the only protein we studied that correlated with the other well-known prognostic factors in CRC. The expression of Ki67 did not bring any novel prognostic information regarding CRC.

Follicle-stimulating hormone receptors: a new immunohistochemical marker in cancers?

PURPOSE: Follicle-stimulating hormone receptors (FSHR) have been reported in ovarian cancer and prostate cancer cells, but recent studies have highlighted their presence in the endothelium of blood vessels belonging to multiple neoplasias. Current research attempts to determine the role of FSHR in neoplastic proliferation and possible therapeutic or diagnostic implications. This paper aimed to analyze articles that have revealed the presence and/or role of FSHR in various neoplasms in humans. METHODS: After performing an extensive search of MEDLINE/ PubMed using MeSH terms "follicle-stimulating hormone receptors" and "cancer", 22 original articles were found relevant for the subject proposed for analysis. RESULTS: FSHR were found in all neoplasms studied, being present in both tumor cells and endothelial cells of intraand perineoplasic blood vessels. Although, the presence of these receptors seemed to be ubiquitary, conclusion and the exact role of these receptors could not be stated due to heterogeneous nature of the existing studies. CONCLUSIONS: Although extensive research studies are needed in order to elucidate the exact role of FSHRs and their utility in clinical practice, joint efforts in studying their implication in neoplastic processes can lead to the use of new diagnostic and therapeutic strategies for cancer patients.

The clinical and biological significance of MIR-224 expression in colorectal cancer metastasis.

OBJECTIVE: MicroRNA (miRNA) expression profile can be used as prognostic marker for human cancers. We aim to explore the significance of miRNAs in colorectal cancer (CRC) metastasis. DESIGN: We performed miRNA microarrays using primary CRC tissues from patients with and without metastasis, and validated selected candidates in 85 CRC samples by quantitative real-time PCR (qRT-PCR). We tested metastatic activity of selected miRNAs and identified miRNA targets by prediction algorithms, qRT-PCR, western blot and luciferase assays. Clinical outcomes were analysed in six sets of CRC cases (n=449), including The Cancer Genome Atlas (TCGA) consortium and correlated with miR-224 status. We used the Kaplan-Meier method and log-rank test to assess the difference in survival between patients with low or high levels of miR-224 expression. RESULTS: MiR-224 expression increases consistently with tumour burden and microsatellite stable status, and miR-224 enhances CRC metastasis in vitro and in vivo. We identified SMAD4 as a miR-224 target and observed negative correlation (Spearman Rs=-0.44, p<0.0001) between SMAD4 and miR-224 expression in clinical samples. Patients with high miR-224 levels display shorter overall survival in multiple CRC cohorts (p=0.0259, 0.0137, 0.0207, 0.0181, 0.0331 and 0.0037, respectively), and shorter metastasis-free survival (HR 6.51, 95% CI 1.97 to 21.51, p=0.0008). In the TCGA set, combined analysis of miR-224 with SMAD4 expression enhanced correlation with survival (HR 4.12, 95% CI 1.1 to 15.41, p=0.0175). CONCLUSIONS: MiR-224 promotes CRC metastasis, at least in part, through the regulation of SMAD4. MiR-224 expression in primary CRC, alone or combined with its targets, may have prognostic value for survival of patients with CRC.

Novel insight into triple-negative breast cancers, the emerging role of angiogenesis, and antiangiogenic therapy.

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumours characterised by lack of expression of oestrogen-, progesterone- and human epidermal growth factor receptors. TNBC, which represents approximately 15% of all mammary tumours, has a poor prognosis because of an aggressive behaviour and the lack of specific treatment. Accordingly, TNBC has become a major focus of research into breast cancer and is now classified into several molecular subtypes, each with a different prognosis. Pathological angiogenesis occurs at a late stage in the proliferation of TNBC and is associated with invasion and metastasis; there is an association with metabolic syndrome. Semaphorins are a versatile family of proteins with multiple roles in angiogenesis, tumour growth and metastasis and may represent a clinically useful focus for therapeutic targeting in this type of breast cancer. Another important field of investigation into the control of pathological angiogenesis is related to the expression of noncoding RNA (ncRNA) - these molecules can be considered as a therapeutic target or as a biomarker. Several molecular agents for intervening in the activity of different signalling pathways are being explored in TNBC, but none has so far proved effective in clinical trials and the disease continues to pose a defining challenge for clinical management as well as innovative cancer research.