Project description:Circulating microRNAs have recently emerged as a new class of promising non-invasive cancer biomarkers. The purpose of this study was the identification by a high-throughput approach (miRNA microarray) of circulating miRNAs associated with breast cancer-derived distant metastasis. To achieve this goal, we resorted to archival plasma samples collected from patients in the control arm of a randomized clinical trial on stage I breast cancer. We compared plasma miRNA levels in patients that developed distant metastasis after a radical or conservative surgery and in those long-term disease-free. Microarray results were technically and independently validated by Real Time PCR. Subsequent in vitro, in vivo and in silico analyses were performed to investigate the miRNA biological/clinical significance in relation with breast cancer progression. We demonstrated that high circulating miR-1246 levels were associated to distant metastasis and that high tissue expression of this miRNA was correlated with unfavorable outcome in ER+HER2- breast cancer patients. In addition, miR-1246 expression was also found to be related with stem-like features. 64 samples (32 patients with metastasis and 32 patients with no metastasis) were considered from a total of 208 hybridized samples collected between 1987 and 2004 (including 94 paired samples according to tumor ER status, age at drawing, drawing year, time from surgery, 7 additional samples from 'no evidence of disease' (NED) patients, 10 references, 1 healthy donor and 2 replicated samples)
Project description:Circulating microRNAs have recently emerged as a new class of promising non-invasive cancer biomarkers. The purpose of this study was the identification by a high-throughput approach (miRNA microarray) of circulating miRNAs associated with breast cancer-derived distant metastasis. To achieve this goal, we resorted to archival plasma samples collected from patients in the control arm of a randomized clinical trial on stage I breast cancer. We compared plasma miRNA levels in patients that developed distant metastasis after a radical or conservative surgery and in those long-term disease-free. Microarray results were technically and independently validated by Real Time PCR. Subsequent in vitro, in vivo and in silico analyses were performed to investigate the miRNA biological/clinical significance in relation with breast cancer progression. We demonstrated that high circulating miR-1246 levels were associated to distant metastasis and that high tissue expression of this miRNA was correlated with unfavorable outcome in ER+HER2- breast cancer patients. In addition, miR-1246 expression was also found to be related with stem-like features.
Project description:Introduction: MicroRNAs (miRNAs) are small, non-coding RNA molecules involved in post-transcriptional gene regulation and have recently been shown to play a role in cancer metastasis. In solid tumors, especially breast cancer, alterations in miRNA expression contribute to cancer pathogenesis, including metastasis. Considering the emerging role of miRNAs in metastasis, the identification of predictive markers is necessary to further understanding of stage-specific breast cancer development. This is a retrospective analysis that aimed to identify molecular biomarkers related to distant breast cancer metastasis development.<br><br>Methods: A retrospective case cohort study was performed in 64 breast cancer patients treated during the period from 1998-2001. The case group (n=29) consisted of patients with a poor prognosis who presented with breast cancer recurrence or metastasis during follow up. The control group (n=35) consisted of a random sample of patients with a good prognosis who did not develop breast cancer recurrence or metastasis. These patient groups were stratified according to TNM clinical stage (CS) I, II and III, and the main clinical features of the patients were homogeneous. miRNA profiling was performed using formalin-fixed, paraffin-embedded tumors. Biomarkers related to metastatic potential were identified independent of clinical stage, and a cutoff point was selected based on the optimal sensitivity and specificity (ROC curve). Finally, a hazard risk analysis of these biomarkers was performed to evaluate their relation to metastatic potential. <br><br>Results: miRNA expression profiling identified several miRNAs that were either specific and shared across all clinical stages (p?0.05). Among these, we identified miRNAs previously associated with cell motility (let-7 family), cell proliferation and invasion (hsa-miR-16 and has-miR-205) and distant metastasis (hsa-miR-21). In addition, hsa-miR-494 and hsa-miR-21 were up-regulated in metastatic cases of CSI and II. Furthermore, the combination of the 3 miRNAs identified for CSII (hsa-miR-494, hsa-miR-183 and hsa-miR-21) was significant and were a more effective risk marker compared to the single miRNAs. <br><br>Conclusions: Women with metastatic breast cancer, especially CSII, presented up-regulated levels of miR-183, miR-494 and miR-21, which were associated with a poor prognosis. These miRNAs therefore represent new risk biomarkers of breast cancer metastasis and may be useful for future targeted therapies.
Project description:MiR-1246 was found to promote tumorigenesis and metastasis in sevearl cancer types. In the context of tumor microenvironment, tumor-associated macrophages are a central part typically correlated with poor prognosis. We used microarray data to determine the gene expression profile in M2-like macrophages when treated with an overexpression of miR-1246 (conducted by miR-1246 mimic). As controls, we used either scambaled mimic control sequence, or a miR-1246 inhibitor.
Project description:Breast cancers contain a minority population of cancer cells characterized by CD44 expression but low or undetectable levels of CD24 (CD44+CD24-/low) that have higher tumorigenic capacity than other subtypes of cancer cells. METHODS: We compared the gene-expression profile of CD44+CD24-/low tumorigenic breast-cancer cells with that of normal breast epithelium. Differentially expressed genes were used to generate a 186-gene invasiveness gene signature (IGS), which was evaluated for its association with overall survival and metastasis-free survival in patients with breast cancer or other types of cancer. RESULTS: There was a significant association between the IGS and both overall and metastasis-free survival (P<0.001, for both) in patients with breast cancer, which was independent of established clinical and pathological variables. When combined with the prognostic criteria of the National Institutes of Health, the IGS was used to stratify patients with high-risk early breast cancer into prognostic categories (good or poor); among patients with a good prognosis, the 10-year rate of metastasis-free survival was 81%, and among those with a poor prognosis, it was 57%. The IGS was also associated with the prognosis in medulloblastoma (P=0.004), lung cancer (P=0.03), and prostate cancer (P=0.01). The prognostic power of the IGS was increased when combined with the wound-response (WR) signature. CONCLUSIONS: The IGS is strongly associated with metastasis-free survival and overall survival for four different types of tumors. This genetic signature of tumorigenic breast-cancer cells was even more strongly associated with clinical outcomes when combined with the WR signature in breast cancer. Expression profling was performed on 6 tumorigenic, 3 non tumorigenic samples of breast tumors and 3 normal breast samples on two different platforms GPL96 and GPL97. A gene signature was derived by comparing the gene expressions of 6 tumorigenic samples with 3 normal breast samples.
Project description:Breast cancers contain a minority population of cancer cells characterized by CD44 expression but low or undetectable levels of CD24 (CD44+CD24-/low) that have higher tumorigenic capacity than other subtypes of cancer cells. METHODS: We compared the gene-expression profile of CD44+CD24-/low tumorigenic breast-cancer cells with that of normal breast epithelium. Differentially expressed genes were used to generate a 186-gene invasiveness gene signature (IGS), which was evaluated for its association with overall survival and metastasis-free survival in patients with breast cancer or other types of cancer. RESULTS: There was a significant association between the IGS and both overall and metastasis-free survival (P<0.001, for both) in patients with breast cancer, which was independent of established clinical and pathological variables. When combined with the prognostic criteria of the National Institutes of Health, the IGS was used to stratify patients with high-risk early breast cancer into prognostic categories (good or poor); among patients with a good prognosis, the 10-year rate of metastasis-free survival was 81%, and among those with a poor prognosis, it was 57%. The IGS was also associated with the prognosis in medulloblastoma (P=0.004), lung cancer (P=0.03), and prostate cancer (P=0.01). The prognostic power of the IGS was increased when combined with the wound-response (WR) signature. CONCLUSIONS: The IGS is strongly associated with metastasis-free survival and overall survival for four different types of tumors. This genetic signature of tumorigenic breast-cancer cells was even more strongly associated with clinical outcomes when combined with the WR signature in breast cancer. Keywords: cell type comparison
Project description:Although an important association between lymph node metastasis and poor prognosis in breast cancer was observed decades ago, an active role for the lymphatic system in metastatic dissemination has only recently been examined. We demonstrate that the Six1 homeoprotein promotes peri- and intra-tumoral lymphangiogenesis, lymphatic invasion, and distant metastasis of breast cancer cells. We identify the pro-lymphangiogenic factor, VEGF-C, as required for this process, and demonstrate transcriptional induction as the mechanism of regulation of VEGF-C expression by Six1. Using a different, but complementary animal model, we show that while required, VEGF-C is not sufficient for the pro-metastatic effects of Six1. Verifying the clinical significance of this pro-metastatic Six1-VEGF-C axis, we demonstrate co-expression of Six1 and VEGF-C in human breast cancer. Two Control and two Six1 expressing MCF7 clones were orthotopically injected into NOD/Scid mice forming a total of 3 Control and 3 Six1 tumors that were allowed to grow to 2 cm^3 . The tumors were dissected and total RNA was isolated from each tumor and hybridized to Affymetrix arrays
Project description:The presence or absence of lymph node metastasis plays a major role in the prediction of prognosis and subsequent patient management. However, good proportion of patients who display lymph node positivity remain disease free for 3 years or more, after the initial treatment, while a third of those who were lymph node negative at presentation, develop distant metastasis within the same period. We performed gene expression profiling on a cohort Indian breast cancer patients followed up for a period of 3-5 years and in comparison with a previously published Caucasian cohort data, we identified gene signatures that are associated with distant metastasis. This association was irrespective of the hormone receptor status. Our results show that the genes that signify immune system development and response are repressed, while factors for DNA replication are up regulated in patients who develop distant metastasis. A large number of genes encoding proteins involved in the mitotic spindle formation that belong to the TRIM28 protein network, are differentially regulated in the metastatic tumors. Also, there was a significant overlap of genes reported in a mouse model of bone metastasis, with patients who developed bone metastasis in our cohort. In conclusion, we present for the first time probable gene signatures that correlate with distant metastasis in breast cancer patients irrespective of nodal or hormone receptor status
Project description:Although an important association between lymph node metastasis and poor prognosis in breast cancer was observed decades ago, an active role for the lymphatic system in metastatic dissemination has only recently been examined. We demonstrate that the Six1 homeoprotein promotes peri- and intra-tumoral lymphangiogenesis, lymphatic invasion, and distant metastasis of breast cancer cells. We identify the pro-lymphangiogenic factor, VEGF-C, as required for this process, and demonstrate transcriptional induction as the mechanism of regulation of VEGF-C expression by Six1. Using a different, but complementary animal model, we show that while required, VEGF-C is not sufficient for the pro-metastatic effects of Six1. Verifying the clinical significance of this pro-metastatic Six1-VEGF-C axis, we demonstrate co-expression of Six1 and VEGF-C in human breast cancer.
Project description:Breast Cancer is the cancer with most incidence and mortality in women. microRNAs are emerging as novel prognosis/diagnostic tools. Our aim was to identify a serum microRNA signature useful to predict cancer development. We focused on studying the expression levels of 30 microRNAs in the serum of 96 breast cancer patients versus 92 control individuals. Bioinformatic studies provide a microRNA signature, designated as a predictor, based upon the expression levels of 5 microRNAs. Then, we tested the predictor in a group of 60 randomly chosen women. Lastly, a proteomic study unveiled the over-expression and down-regulation of proteins differently expressed in the serum of breast cancer patients versus that of control individuals. Twenty-six microRNAs differentiate cancer tissue from healthy tissue and 16 microRNAs differentiate the serum of cancer patients from that of the control group. The tissue expression of miR-99a-5p, mir-497-5p, miR-362, and miR-1274, and the serum levels of miR-141 correlated with patient survival. Moreover, the predictor consisting of mir-125b-5p, miR-29c-3p, mir-16-5p, miR-1260, and miR-451a was able to differentiate breast cancer patients from controls. The predictor was validated in 20 new cases of breast cancer patients and tested in 60 volunteer women, assigning 11 out of 60 women to the cancer group. An association of low levels of mir-16-5p with a high content of CD44 protein in serum was found. Circulating microRNAs in serum can represent biomarkers for cancer prediction. Their clinical relevance and use of the predictor here described might be of potential importance for breast cancer prediction.