Project description:In this study, using microarray technology we did a transcriptome profiling of miRNAs on a group of 52 cases of familial (BRCA1- or BRCA2-mutated, or BRCAX, i.e. familial cases with no mutations in BRCA1 or BRCA2 genes) and sporadic breast cancers. Class comparison of different clinical characteristics of the samples identified miR-342 as the miRNA with the most significant association with estrogen receptor (ER) status (categorised as positive and negative) of the samples analysed. As ER is one of the bio-pathological features currently used in routine clinical practice to aid treatment decision in breast cancer, identification of this miRNA has been promising for finding new mechanisms involved in this tumour type as we had next demonstrated in a cellular model of breast cancer. In the study presented here, microRNAs expression profiling on a well defined cohort of 52 breast cancer cases, followed up for more than 5 years, was used for a class comparison analysis with some relevant clinical characteristics of this tumour type like estrogen, progesterone or epidermal growth factor 2 receptor status.
Project description:In this study, using microarray technology we did a transcriptome profiling of miRNAs on a group of 52 cases of familial (BRCA1- or BRCA2-mutated, or BRCAX, i.e. familial cases with no mutations in BRCA1 or BRCA2 genes) and sporadic breast cancers. Class comparison of different clinical characteristics of the samples identified miR-342 as the miRNA with the most significant association with estrogen receptor (ER) status (categorised as positive and negative) of the samples analysed. As ER is one of the bio-pathological features currently used in routine clinical practice to aid treatment decision in breast cancer, identification of this miRNA has been promising for finding new mechanisms involved in this tumour type as we had next demonstrated in a cellular model of breast cancer.
Project description:Background: With less than a 5% survival rate pancreatic adenocarcinoma (PDAC) is almost uniformly lethal. In order to make a significant impact on survival of patients with this malignancy, it is necessary to diagnose the disease early, when curative surgery is still possible. Detailed knowledge of the natural history of the disease and molecular events leading to its progression is therefore critical. Methods and Findings: We have analysed the precursor lesions, PanINs, from prophylactic pancreatectomy specimens of patients from four different kindreds with high risk of familial pancreatic cancer who were treated for histologically proven PanIN-2/3. Thus, the material was procured before pancreatic cancer has developed, rather than from PanINs in a tissue field that already contains cancer. Genome-wide transcriptional profiling using such unique specimens was performed. Bulk frozen sections displaying the most extensive but not microdissected PanIN-2/3 lesions were used in order to obtain the holistic view of both the precursor lesions and their microenvironment. A panel of 76 commonly dysregulated genes that underlie neoplastic progression from normal pancreas to PanINs and PDAC were identified. In addition to shared genes some differences between the PanINs of individual families as well as between the PanINs and PDACs were also seen. This was particularly pronounced in the stromal and immune responses. Conclusions: Our comprehensive analysis of precursor lesions without the invasive component provides the definitive molecular proof that PanIN lesions beget cancer from a molecular standpoint. We demonstrate the need for accumulation of transcriptomic changes during the progression of PanIN to PDAC, both in the epithelium and in the surrounding stroma. An identified 76-gene signature of PDAC progression presents a rich candidate pool for the development of early diagnostic and/or surveillance markers as well as potential novel preventive/therapeutic targets for both familial and sporadic pancreatic adenocarcinoma. Gene expression of 13 PanIN samples was compared to profiling data of whole biopsies from normal donor pancreas (N1 to 4, two replicated samples) and sporadic PDAC (PDAC1 to 6).Ttwo PDAC samples (PDAC 3 and 4) and a replicate of one normal specimen (N4) were removed during the hybridisation quality assessment.
Project description:Background: With less than a 5% survival rate pancreatic adenocarcinoma (PDAC) is almost uniformly lethal. In order to make a significant impact on survival of patients with this malignancy, it is necessary to diagnose the disease early, when curative surgery is still possible. Detailed knowledge of the natural history of the disease and molecular events leading to its progression is therefore critical. Methods and Findings: We have analysed the precursor lesions, PanINs, from prophylactic pancreatectomy specimens of patients from four different kindreds with high risk of familial pancreatic cancer who were treated for histologically proven PanIN-2/3. Thus, the material was procured before pancreatic cancer has developed, rather than from PanINs in a tissue field that already contains cancer. Genome-wide transcriptional profiling using such unique specimens was performed. Bulk frozen sections displaying the most extensive but not microdissected PanIN-2/3 lesions were used in order to obtain the holistic view of both the precursor lesions and their microenvironment. A panel of 76 commonly dysregulated genes that underlie neoplastic progression from normal pancreas to PanINs and PDAC were identified. In addition to shared genes some differences between the PanINs of individual families as well as between the PanINs and PDACs were also seen. This was particularly pronounced in the stromal and immune responses. Conclusions: Our comprehensive analysis of precursor lesions without the invasive component provides the definitive molecular proof that PanIN lesions beget cancer from a molecular standpoint. We demonstrate the need for accumulation of transcriptomic changes during the progression of PanIN to PDAC, both in the epithelium and in the surrounding stroma. An identified 76-gene signature of PDAC progression presents a rich candidate pool for the development of early diagnostic and/or surveillance markers as well as potential novel preventive/therapeutic targets for both familial and sporadic pancreatic adenocarcinoma.