Angiogenesis, which plays an important role in tumor growth and progression of breast cancer, is regulated by a balance between pro- and anti-angiogenic factors. Expression of vascular endothelial growth factor (VEGF) is up-regulated during hypoxia by hypoxia-inducible factor-1α (HIF-1α). It is known that there is an interaction between HIF-1α and BRCA1 carrier cancers, but little has been reported about angiogenesis in BRCA1-2 carrier and BRCAX breast cancers. In this study, we investigated the expression of VEGF and HIF-1α and microvessel density (MVD) in 26 BRCA1-2 carriers and 58 BRCAX compared to 77 sporadic breast cancers, by immunohistochemistry. VEGF expression in BRCA1-2 carriers was higher than in BRCAX cancer tissues (p = 0.0001). Furthermore, VEGF expression was higher in both BRCA1-2 carriers and BRCAX than the sporadic group (p<0.0001). VEGF immunoreactivity was correlated with poor tumor grade (p = 0.0074), hormone receptors negativity (p = 0.0206, p = 0.0002 respectively), and MIB-1-labeling index (p = 0.0044) in familial cancers (BRCA1-2 and BRCAX). The percentage of nuclear HIF-1α expression was higher in the BRCA1-2 carriers than in BRCAX cancers (p<0.05), and in all familial than in sporadic tumor tissues (p = 0.0045). A higher MVD was observed in BRCA1-2 carrier than in BRCAX and sporadic cancer tissues (p = 0.002, p = 0.0001 respectively), and in all familial tumors than in sporadic tumors (p = 0.01). MVD was positively related to HIF-1α expression in BRCA1-2 carriers (r = 0.521, p = 0.006), and, in particular, we observed a highly significant correlation in the familial group (r = 0.421, p<0.0001). Our findings suggest that angiogenesis plays a crucial role in BRCA1-2 carrier breast cancers. Prospective studies in larger BRCA1-2 carrier series are needed to improve the best therapeutic strategies for this subgroup of breast cancer patients.
As in women, three classes of breast cancer genetic susceptibility (high, moderate, and low penetrance) are recognized in men. However, genes involved and their impact do not exactly overlap in female and male BC. Epigenetic alterations are currently scarcely investigated in MBC, however, the different methylation and miRNA expression profiles identified to date in female and male BCs suggest a potential role for epigenetic alterations as diagnostic biomarkers. Overall, much still needs to be learned about MBC and, because of its rarity, the main effort is to develop large consortia for moving forward in understanding MBC and improving the management of MBC patients on a perspective of gender medicine.
Despite the search for new therapeutic strategies for gastric cancer (GC), there is much evidence of progression due to resistance to chemotherapy. Multidrug resistance (MDR) is the ability of cancer cells to survive after exposure to chemotherapeutic agents. The involvement of miRNAs in the development of MDR has been well described but miRNAs able to modulate the sensitivity to chemotherapy by regulating hypoxia signaling pathways have not yet been fully addressed in GC. Our aim was to analyze miR-20b, miR-27a and miR-181a expression with respect to (epirubicin/oxaliplatin/capecitabine (EOX)) chemotherapy regimen in a set of GC patients, in order to investigate whether miRNAs deregulation may influence GC MDR also via hypoxia signaling modulation. Cancer biopsy were obtained from 21 untreated HER2 negative advanced GC patients, retrospectively analyzed. All patients received a first-line chemotherapy (EOX) regimen. MirWalk database was used to identify miR-27a, miR-181a and miR-20b target genes. The expression of miRNAs and of HIPK2, HIF1A and MDR1 genes were detected by real-time PCR. HIPK2 localization was assessed by immunohistochemistry. Our data showed the down-regulation of miR-20b, miR-27a, miR-181a concomitantly to higher levels of MDR1, HIF1A and HIPK2 genes in GC patients with a progressive disease respect to those with a disease control rate. Moreover, immunohistochemistry assay highlighted a higher cytoplasmic HIPK2 staining, suggesting a different role for it. We showed that aberrant expression of miR-20b, miR27a and miR-181a was associated with chemotherapeutic response in GC through HIF1A, MDR1 and HIPK2 genes modulation, suggesting a possible novel therapeutic strategy.
Angiogenesis leads to the formation of blood vessels from pre-existing ones, allowing tumor growth. Vascular endothelial growth factor (VEGF) and Angiopoietins (Ang-1, Ang-2) have a pivotal role in tumor angiogenesis but few data regarding their role in hereditary breast cancer are available. The aim of the present study was to analyze Ang-1, Ang-2, tyrosine-protein kinase receptor Tie2 and VEGF expression and their correlation in a cohort of familial and sporadic breast cancers in order to verify whether the presence of germline mutations in BRCA may have a role in tumor microenvironment regulation. Tumor samples from a cohort of 41 patients with a first diagnosis and a family history of breast cancer and 19 patients with sporadic breast cancers were enrolled. The expression of Tie2, Ang-1, Ang-2 and VEGF were analyzed by quantitative real-time PCR. Patients harboring BRCA mutations had higher levels of Ang-1 (P ¼ 0.05), Ang-2 (P ¼ 0.02) and VEGF (P ¼ 0.04) mRNA compared with those without BRCA mutations (BRCAX). The same was observed in triple-negative breast cancer (TNBC). Moreover, a positive correlation between Ang-2 and VEGF was found in both the familial breast cancer group (BRCA carriers: r ¼ 0.83; Po0.0001 and BRCAX: r ¼ 0.58; P ¼ 0.008) and in TNBC (r ¼ 0.62; P ¼ 0.007). The higher levels of Ang-1, Ang-2 and VEGF mRNA found in BRCA carriers and TNBCs suggest that they could be attractive angiogenic therapeutic targets in these breast cancers.
The involvement of microRNA (miRNAs), a new class of small RNA molecules, in governing angiogenesis has been well described. Our aim was to investigate miRNA-mediated regulation of angiogenesis in a series of familial breast cancers stratified by BRCA1/2 mutational status in BRCA carriers and BRCA non-carriers (BRCAX). Affymetrix GeneChip miRNA Arrays were used to perform miRNA expression analysis on 43 formalin-fixed paraffin-embedded (FFPE) tumour tissue familial breast cancers (22 BRCA 1/2-related and 21 BRCAX). Pathway enrichment analysis was carried out with the DIANA miRPath v2.0 web-based computational tool, and the miRWalk database was used to identify target genes of deregulated miRNAs. An independent set of 8 BRCA 1/2-related and 11 BRCAX breast tumors was used for validation by Real-Time PCR. In vitro analysis on HEK293, MCF-7 and SUM149PT cells were performed to best-clarify miR-573 and miR-578 role. A set of 16 miRNAs differentially expressed between BRCA 1/2-related and BRCAX breast tumors emerged from the profile analysis. Among these, miR-578 and miR-573 were found to be down-regulated in BRCA 1/2-related breast cancer and associated to the Focal adhesion, Vascular Endothelial Growth Factor (VEGF) and Hypoxia Inducible Factor-1 (HIF-1) signaling pathways. Our data highlight the role of miR-578 and miR-573 in controlling BRCA 1/2-related angiogenesis by targeting key regulators of Focal adhesion, VEGF and HIF-1 signaling pathways.
Purpose : We previously showed that about 80% of breast cancer patients at high risk to carry mutation in BRCA genes presented at least one polymorphism in these genes which resulted potentially harmful by in silico analysis. In the present paper the genealogic transmission of those polymorphic coding and non coding variants of BRCA genes in family's members has been investigated.Methods: 30 families, enrolled within the Genetic Counselling Program of our Institute, with probands and at least one first degree relative (n=67 family members) available, have been studied for both BRCA1 and BRCA2 pathological mutation and polymorphic variants' transmission.Results: 10 and 6 probands carried mendelian transmitted mutations in BRCA1 and BRCA2, respectively. Polymorphic coding and non coding variants were transmitted in each family's relatives with a frequency ranging from 42% to100% , with similar rate for each SNP in mutated and non mutated families with the only exception of BRCA1 K1183R significantly more frequent in mutated families (p=0.004); conversely, this SNP and BRCA2 N372H, were more frequently present in breast cancer relatives belonging to families in which pathological BRCA mutations were not present. Furthermore, specific haplotypes were transmitted in all relatives as BRCA1 871Leu-1038Gly, present in both BRCA mutated and non mutated families, while BRCA2 289His-991Asp-IVS14+53 C>T present only in BRCAX families suggesting the harmful role of these SNPs. Conclusions:Analysis of SNPs maps and modality of their transmission could identify further susceptibility markers and provide a basis for a better DNA-based cancer classification.
The number of treatment options for melanoma patients has grown in the past few years, leading to considerable improvements in both overall and progression-free survival. Targeted therapies and immune checkpoint inhibitors have opened a new era in the management of melanoma patients. Despite the clinical advances, further research efforts are needed to identify other "druggable" targets and new biomarkers to improve the stratification of melanoma patients who could really benefit from targeted and immunotherapies. To this end, many studies have focused on the role of microRNAs (miRNAs) that are small non-coding RNAs (18-25 nucleotides in length), which post-transcriptionally regulate the expression of their targets. In cancer, they can behave either as oncogenes or oncosuppressive genes and play a central role in many intracellular pathways involved in proliferation and invasion. Given their modulating activity on the transcriptional landscape, their biological role is under investigation to study resistance mechanisms. They are able to mediate the communication between tumor cells and their microenvironment and regulate tumor immunity through direct regulation of the genes involved in immune activation or suppression. To date, a very promising miRNA-based strategy is to use them as prognosis and diagnosis biomarkers both as cell-free miRNAs and extracellular-vesicle miRNAs. However, miRNAs have a complex role since they target different genes in different cellular conditions. Thus, the ultimate aim of studies has been to recapitulate their role in melanoma in biological networks that account for miRNA/gene expression and mutational state. In this review, we will provide an overview of current scientific knowledge regarding the oncogenic or oncosuppressive role of miRNAs in melanoma and their use as biomarkers, with respect to approved therapies for melanoma treatment.
In recent years, the assessment of biomarkers useful for “precision medicine” has been a hot topic in research. The involvement of microRNAs in the pathogenesis of breast cancer has been highly investigated with the aim of being able to molecularly stratify this highly heterogeneous disease. Our aim was to identify microRNAs targeting DNA repair machinery, through Affymetrix GeneChip miRNA Arrays, in a cohort of BRCA-related and sporadic breast cancers. Moreover, we analyzed microRNA expression taking into account our previous results on the expression of PARP1, because of its importance in targeted therapy. miR-361-5p and miR-151-5p were found to be overexpressed in PARP1-upregulating BRCA-germline mutated and sporadic breast tumors. Pathway enrichment analysis was performed to identify potential target genes to be analyzed in the validation step in an independent cohort. Our results confirmed the overexpression of miR-151-5p and, interestingly, its role in the targeting of SMARCA5, a chromatin remodeler. This result was also confirmed in vitro, both through luciferase assay and by analyzing endogenous levels of SMARCA5 in MCF-7 cell lines using miR-151-5p mimic and inhibitor. In conclusion, our data showed the possibility of considering the overexpression of PARP1 and miR-151-5p as biomarkers useful to correctly treat sporadic breast cancers, which eventually could be considered as BRCAness tumors, with PARP-inhibitors.
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