10 Minutes Talk 吳 華 席 Hua-Hsi Wu, MD OB/GYN, VGH-TPE Aug 12, 2008.
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Transcript of 10 Minutes Talk 吳 華 席 Hua-Hsi Wu, MD OB/GYN, VGH-TPE Aug 12, 2008.
10 Minutes Talk
吳 華 席Hua-Hsi Wu, MD
OB/GYN, VGH-TPEAug 12, 2008
Impact of Determining PALN Metastases/Gold et al
Ovarian cancer, MicroRNA, Exosome
Impact of Determining PALN Metastases/Gold et al
IntroductionOvarian cancer
Worldwide, 6th most common in female & 125,000 deaths annually
75% diagnosed as extra-ovarian dz (EM ca 73%, Breast ca 55% & Cx ca 50% in stage 1)
5-yr survival: stage 1 > 90%, advanced stage 21%
How to early Dx?
Impact of Determining PALN Metastases/Gold et al
IntroductionMicroRNA
Small (21-25 nucleotides in length) non-coding RNAs
Suppress the translation of target mRNAs by binding to their 3” untranslateed region
Post-transcriptional silencing Cleavage of homologus mRNA Specific inhibition of protein synthesis
Critical regulator of cellular processes Proliferation, differentiation, development & ce
ll death
Impact of Determining PALN Metastases/Gold et al
IntroductionMicroRNA
Distinct MicroRNAs signature, classify human cancers
Ovarian cancers: miR-21, miR-141, miR-200a, miR-200b, miR-200c, miR-
203, miR-205 & miR-214 Up-modulation of specific microRNA could be the
amplification of its gene. Is microRNAsignature better than mRNA signature,
in cnacer Dx, staging, progression, and response to treatment
Impact of Determining PALN Metastases/Gold et al
Biogenesis of microRNAs
Impact of Determining PALN Metastases/Gold et al
Detailed structures of pri-, pre- and mature miRNAs
Impact of Determining PALN Metastases/Gold et al
IntroductionExosome
small (50-100nm) membrane vesicles of endocytic origin, in the peripheral circulation (of ovarian cancer patients was found initially in 1979)
Source Except cancers, including reticulocytes, dendritic cells,
B cells, T cells, mast cells, epithelial cells, and embryonic cells.
All exosomes share certain common characteristics (structures, size, density & general protein composition)
Impact of Determining PALN Metastases/Gold et al
IntroductionExosome
Cell-cell communication Directly by surface expressed ligands By transferring molecules between cells
Exosomes contains both cellular mRNA and miRNAs
While tumor-derived exosomes exhibit some common, shared proteins, they also express an array of tumor antigens that reflect the originating tumor cells.
Impact of Determining PALN Metastases/Gold et al
Material and Methods
Serum & biopsied tissue Serous papillary adenocarcinoma
Stage I n=10, stage II n=10, stage III n=20, stage IV n=10 Ovarian adenoma n=10 NED of ovarian diseases n=10
Isolation of circulating exosomes MACS (EpCAM, anti-epithelial cell adhesion molecules)
Isolation & profiling of miRNAs mirVana microRNA isolation kit
Impact of Determining PALN Metastases/Gold et al
Results
Impact of Determining PALN Metastases/Gold et al
Panel A: The levels of circulating tumor-derived exosomes compared to stage of ovarian cancer
Panel B: Electron micrograph of circulating exosomes isolated by magnetic beads.
Impact of Determining PALN Metastases/Gold et al
Presence of small RNA associated with circulating EpCAM-positive exosomes from ovarian cancer patients
Impact of Determining PALN Metastases/Gold et al
**Intensities for specific microRNAs derived from the advanced-staged ovarian tumors (□) and from EpCAM-positive exosomes (■) isolated from the sera of these patients.
**miR-21, miR-141, miR-200a, miR-200b, miR-200c, miR-203, miR-205, and miR-214 have previously been demonstrated to be upregulated markers for ovarian cancer
Impact of Determining PALN Metastases/Gold et al
Comparison of miRNA with peripheral blood-derive
d exosomes and their corresponding tumors
Impact of Determining PALN Metastases/Gold et al
miRNAs in exosomescompared by stages
Impact of Determining PALN Metastases/Gold et al
Comparison of specific exosomal miRNAs
immediately after blood draw or 24, 48, & 96 hr later
Impact of Determining PALN Metastases/Gold et al
Appendix A
Impact of Determining PALN Metastases/Gold et al
Results MicroRNA from ovarian tumor cells and exosomes from the
same patients were positive for 218 of 467 mature microRNAs analyzed.
The levels of the 8 specific microRNAs were similar between cellular and exosomal microRNAs (exhibiting correlations from 0.71 to 0.90). While EpCAM-positive exosomes were detectable in both patients with benign ovarian disease and ovarian cancer, exosomal microRNA from ovarian
cancer patients exhibited similar profiles, which were significantly distinct from profiles observed in benign disease. Exosomal microRNA could not be detected in normal controls.
Impact of Determining PALN Metastases/Gold et al
Conclusions
These results suggest that microRNA profiling of circulating tumor exosomes could potentially be used as surrogate diagnostic markers for biopsy profiling, extending its utility to screening asymptomatic populations.