Project description:Ductal carcinoma in situ (DCIS) is a precursor lesion that can give rise to invasive breast cancer (IBC). It has been proposed that both the nature of the lesion and the tumor microenvironment play key roles in progression to IBC. Here, laser capture microdissected tissue samples from epithelium and stroma in normal breast, pure DCIS, and pure IBC were employed to define key gene expression profiles associated with disease progression. Tumor and matching stroma were profiled for 9 DCIS patients, 10 IBC patients, and 3 normal breast. Differential gene expression was evaluated for paired normal stroma versus normal epitelium samples, paired DCIS stroma versus DCIS epitelium samples, paired IBC stroma versus IBC epitelium, IBC stroma versus DCIS stroma, and IBC epithelium versus DCIS epithelium.
Project description:Normal-appearing epithelium of cancer patients can harbor occult genetic abnormalities. Data comprehensively comparing gene expression between histologically normal breast epithelium of breast cancer patients and cancer-free controls are limited. The present study compares global gene expression between these groups. We performed microarrays using RNA from microdissected histologically normal terminal ductal-lobular units (TDLU) from 2 groups: (i) cancer normal (CN) (TDLUs adjacent to untreated ER1 breast cancers (n = 14)) and (ii) reduction mammoplasty (RM) (TDLUs of age-matched women without breast disease (n = 15)). Cyber-T identi?ed differentially expressed genes. Quantitative RT-PCR (qRT-PCR), immunohistochemistry (IHC), and comparison to independent microarray data including 6 carcinomas in situ (CIS), validated the results. Gene ontology (GO), UniProt and published literature evaluated gene function. About 127 probesets, corresponding to 105 genes, were differentially expressed between CN and RM (p < 0.0009, corresponding to FDR <0.10). 104/127 (82%) probesets were also differentially expressed between CIS and RM, nearly always (102/104 (98%)) in the same direction as in CN vs. RM. Two-thirds of the 105 genes were implicated previously in carcinogenesis. Overrepresented functional groups included transcription, G-protein coupled and chemokine receptor activity, the MAPK cascade and immediate early genes. Most genes in these categories were under-expressed in CN vs. RM. We conclude that global gene expression abnormalities exist in normal epithelium of breast cancer patients and are also present in early cancers. Thus, cancer-related pathways may be perturbed in normal epithelium. These abnormalities could be markers of disease risk, occult disease, or the tissueâs response to an existing tumor. Experiment Overall Design: 29 samples from histologically normal microdissected breast epithelium are included in this series. 14 samples are from epithelium adjacent to a breast tumor, 15 samples were obtained from patients undergoing reduction mammoplasty without apparent breast cancer
Project description:Gene expression in histologically normal epithelium from breast cancer patients and cancer-free prophylactic mastectomy patients share a similar profile Introduction: We hypothesized that gene expression in histologically normal epithelium (NlEpi) would differ in breast cancer patients (HN) compared to usual-risk controls undergoing reduction mammoplasty (RM), and that gene expression in NlEpi from cancer-free prophylactic mastectomies from high-risk women (PM), would resemble HN gene expression. Methods: We analyzed gene expression in 73 NlEpi samples microdissected from frozen tissue. In 42 cases, we used Affymetrix HU133A microarrays to compare gene expression in 18 RM vs 18 age-matched HN (9 ER+, 9 ER-) and 6 PM. Data were validated with qPCR in 31 independent NlEpi samples (8 RM, 17 HN, 6 PM). Results: 98 probesets (86 genes) were differentially expressed between RM and HN samples. Perfoming supervised hierarchical analysis with these 98 probesets, PM and HN samples clustered together, away from RM samples. qPCR validation of independent samples was high (84%) and uniform in RM vs HN, and lower (58%), but more heterogeneous, in RM vs PM. The 86 genes were implicated in many processes including transcription and the MAPK pathway. Conclusion: Gene expression differs between NlEpi of cancer cases and controls. The cancer cases' profile can be discerned in high-risk NlEpi. This suggests that the profile is not an effect of the tumor, but may mark increased risk and reveal breast cancer's earliest genomic changes. We determined that 98 probesets significantly differed between reduction mammoplasty and histologically normal epithelium from breast cancer patients. We also found that the histologically normal epithelium from prophylactic mastectomy patients' gene expression was more similar to histologically normal epithelium from breast cancer patients' than to reduction mammoplasty patients' gene expression. These results demonstrate that gene expression differs between NlEpi of cancer cases and controls. The cancer cases’ profile can be discerned in high-risk NlEpi. This suggests that the profile is not an effect of the tumor, but may mark increased risk and reveal breast cancer's earliest genomic changes.
Project description:Gene expression in histologically normal epithelium from breast cancer patients and cancer-free prophylactic mastectomy patients share a similar profile Introduction: We hypothesized that gene expression in histologically normal epithelium (NlEpi) would differ in breast cancer patients (HN) compared to usual-risk controls undergoing reduction mammoplasty (RM), and that gene expression in NlEpi from cancer-free prophylactic mastectomies from high-risk women (PM), would resemble HN gene expression. Methods: We analyzed gene expression in 73 NlEpi samples microdissected from frozen tissue. In 42 cases, we used Affymetrix HU133A microarrays to compare gene expression in 18 RM vs 18 age-matched HN (9 ER+, 9 ER-) and 6 PM. Data were validated with qPCR in 31 independent NlEpi samples (8 RM, 17 HN, 6 PM). Results: 98 probesets (86 genes) were differentially expressed between RM and HN samples. Perfoming supervised hierarchical analysis with these 98 probesets, PM and HN samples clustered together, away from RM samples. qPCR validation of independent samples was high (84%) and uniform in RM vs HN, and lower (58%), but more heterogeneous, in RM vs PM. The 86 genes were implicated in many processes including transcription and the MAPK pathway. Conclusion: Gene expression differs between NlEpi of cancer cases and controls. The cancer cases' profile can be discerned in high-risk NlEpi. This suggests that the profile is not an effect of the tumor, but may mark increased risk and reveal breast cancer's earliest genomic changes. We determined that 98 probesets significantly differed between reduction mammoplasty and histologically normal epithelium from breast cancer patients. We also found that the histologically normal epithelium from prophylactic mastectomy patients' gene expression was more similar to histologically normal epithelium from breast cancer patients' than to reduction mammoplasty patients' gene expression. These results demonstrate that gene expression differs between NlEpi of cancer cases and controls. The cancer casesâ?? profile can be discerned in high-risk NlEpi. This suggests that the profile is not an effect of the tumor, but may mark increased risk and reveal breast cancer's earliest genomic changes. 42 total laser capture microdissected histologically normal breast tissue samples were analyzed with Affymetrix HU133A microarrays. 36 samples were age-matched between reduction mammoplasty (n=18) and histologically normal epithelial samples from breast cancer patients (n=18; 9ER+, 9ER-). 6 histologically normal epithelial samples from prophylactic mastectomy patients were then compared to data generated from the original 36 sample comparison. Sample numbers correspond to individual patient samples.
Project description:Ductal carcinoma in situ (DCIS) is a precursor lesion that can give rise to invasive breast cancer (IBC). It has been proposed that both the nature of the lesion and the tumor microenvironment play key roles in progression to IBC. Here, laser capture microdissected tissue samples from epithelium and stroma in normal breast, pure DCIS, and pure IBC were employed to define key gene expression profiles associated with disease progression.
Project description:Normal-appearing epithelium of cancer patients can harbor occult genetic abnormalities. Data comprehensively comparing gene expression between histologically normal breast epithelium of breast cancer patients and cancer-free controls are limited. The present study compares global gene expression between these groups. We performed microarrays using RNA from microdissected histologically normal terminal ductal-lobular units (TDLU) from 2 groups: (i) cancer normal (CN) (TDLUs adjacent to untreated ER1 breast cancers (n = 14)) and (ii) reduction mammoplasty (RM) (TDLUs of age-matched women without breast disease (n = 15)). Cyber-T identi?ed differentially expressed genes. Quantitative RT-PCR (qRT-PCR), immunohistochemistry (IHC), and comparison to independent microarray data including 6 carcinomas in situ (CIS), validated the results. Gene ontology (GO), UniProt and published literature evaluated gene function. About 127 probesets, corresponding to 105 genes, were differentially expressed between CN and RM (p < 0.0009, corresponding to FDR <0.10). 104/127 (82%) probesets were also differentially expressed between CIS and RM, nearly always (102/104 (98%)) in the same direction as in CN vs. RM. Two-thirds of the 105 genes were implicated previously in carcinogenesis. Overrepresented functional groups included transcription, G-protein coupled and chemokine receptor activity, the MAPK cascade and immediate early genes. Most genes in these categories were under-expressed in CN vs. RM. We conclude that global gene expression abnormalities exist in normal epithelium of breast cancer patients and are also present in early cancers. Thus, cancer-related pathways may be perturbed in normal epithelium. These abnormalities could be markers of disease risk, occult disease, or the tissue’s response to an existing tumor. Keywords: disease state analysis
Project description:Histologically normal breast epithelium and stroma were laser capture microdissected from breast reduction specimens and from specimens of invasive ductal carcinoma. The objective of the study was to compare normal reduction tissues to tissues adjacent to I.D.C. to determine whether adjacent normal tissues contained expression profiles correlated with characteristics of the primary tumor and to identify markers of normal epithelium and stroma. Keywords: disease state analysis