SUMMARY Transcript-selective translational regulation of epithelial-mesenchymal transition (EMT) by transforming growth factor-β (TGFβ) is directed by the hnRNP E1-containing TGFβ-activated-translational (BAT) mRNP complex. Herein, eukaryotic elongation factor-1 A1 (eEF1A1) is identified as an integral component of the BAT complex. Translational silencing of Dab2 and ILEI, two EMT-transcripts, is mediated by binding of hnRNP E1 and eEF1A1 to their 3′-UTR BAT element, whereby hnRNP E1 stalls translational elongation by inhibiting the release of eEF1A1 from the ribosomal A site. TGFβ-mediated hnRNP E1 phosphorylation, through Akt2, disrupts the BAT complex, thereby restoring translation of target EMT-transcripts. Attenuation of hnRNP E1 expression in two non-invasive breast epithelial cells (NMuMG and MCF-7) induced not only EMT, but also enabled cells to form metastatic lesions in vivo. Thus, translational regulation by TGFβ, at the elongation stage, represents a critical checkpoint coordinating the expression of EMT-transcripts required during development and in tumorigenesis and metastatic progression.
Brain metastases (BM) from breast cancer are associated with significant morbidity and mortality. In the current study, we have examined a cohort of breast cancer patients who went on to develop BM for clinical-pathologic features and predictive markers that identify this high-risk subgroup of patients at the time of diagnosis. The primary tumors from 55 patients who developed BM were used to construct a tissue microarray. The clinical and pathologic features were recorded and the tissue microarray was stained for estrogen receptor, human epidermal growth factor receptor 2, cytokeratin 5/6, and epidermal growth factor receptor by immunohistochemistry. This cohort of patients was compared against a group of 254 patients who remain free of metastases (67 mo mean follow-up), and another cohort of 40 patients who developed mixed visceral and bone metastatic disease without brain recurrence over a similar period of time. Breast cancer patients who went on to develop BM were more likely to be <50 years old (P<0.001), and the primary tumors were more likely to be estrogen receptor negative (P<0.001) and high grade (P=0.002). The primary tumors were also more likely to express cytokeratin 5/6 (P<0.001) and epidermal growth factor receptor (P=0.001), and to overexpress human epidermal growth factor receptor 2 (P=0.001). The data presented above suggest a profile for breast cancer patients at increased risk for developing BM. Predictive factors to help identify patients with metastatic breast cancer who are at an increased risk for developing central nervous system recurrence might allow for screening of this population for early detection and treatment or for the development of targeted strategies for prevention.
We report the clinical trial studies for the ThinPrep Imaging System (TIS; Cytyc, Boxborough, MA). Between December 2000 and July 2001, 10,742 ThinPrep specimens were collected at 4 US clinical sites representative of the normal clinical population of the laboratories, including screening patients and referred patients. After nonstudy screening diagnoses were completed, the vials were relabeled and randomized, and study slides were prepared and stained. TIS-trained cytotechnologists and pathologists screened the slides twice, first manually, then TIS-assisted after an appropriate interval. Afterward, 3 independent pathologists performed an adjudication study to determine definitive diagnoses for the nonnegative slides and 5% of the negative slides; the adjudicated diagnoses served as the "gold standard" for subsequent sensitivity and specificity analyses. TIS-assisted screening was statistically more sensitive than manual screening for atypical squamous cells of undetermined significance (ASCUS) or higher (+) and statistically equivalent for low- (LSIL)+ and high-grade squamous intraepithelial lesion (HSIL)+ diagnoses. TIS-assisted screening had equivalent specificity for ASCUS+ and LSIL+ and significantly higher specificity for HSIL+. Average cytologists' daily screening rates doubled with TIS-assisted screening. The sensitivity of the TIS-assisted screening system equals or exceeds the sensitivity of manual primary screening without adversely affecting specificity, and TIS-assisted screening can improve cervical cancer screening productivity. Cost issues require further study.
Two hundred forty-two breast fine-needle aspirates prepared by the Cytyc ThinPrep Processor were compared with aspirates prepared by the conventional smear method. Palpable and nonpalpable mammographic breast lesions were aspirated and the first half of the aspirate was submitted for conventional smears and the second half was rinsed into a proprietary fixative and loaded on the ThinPrep Processor for monolayer slide preparation. The matched pairs were diagnosed and analyzed separately in a double-blinded manner and later paired for comparison. Diagnoses correlated exactly in 62% of cases. The diagnosis of fibroadenoma was made in only 4 of 21 cases on ThinPrep (19% correlation). Semiquantitative analysis of several cytologic features indicated potential pitfalls for accurate diagnosis using the ThinPrep Processor. These included loss of background constituents (such as stroma and adipose tissue), decreased cellularity and single ductal epithelial cells, and decreased cytologic detail including size, shape and nuclear texture. The ThinPrep Processor may play a role in breast fine-needle aspiration, but further investigation is warranted before it is used as a sole preparatory method.
Purpose: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1protein expression correlated with genomic copy number changes. Experimental Design: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1staining. Results: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P = 0.006) or HER2 positive (P = 0.039) and <50 years old at diagnosis (P = 0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1protein expression and reduced disease-free survival when stratified by either loss of ER (P = 0.008) or PR (P = 0.029) or HER2 overexpression (P = 0.026). Overall, there was poor correlation between BRMS1protein staining and copy number status. Conclusions: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors.The breast cancer metastasis suppressor 1 (BRMS1) is one of a growing number of genes that have the ability to suppress metastasis without affecting tumorigenicity in experimental in vivo models (1 -4). BRMS1 maps to chromosome 11q13, a region where nonrandom amplification and deletions have been associated with progression and metastasis in breast cancer patients (5). BRMS1 is a predominantly nuclear protein that contains an imperfect leucine zipper motif and coiledcoiled domains, implying that it may function as part of a transcriptional complex (1), and recent studies suggest that BRMS1 may inhibit metastasis, in part, through gene regulation via interaction with histone deacetylases (6, 7). The restoration of BRMS1 expression was recently shown to correlate with reduced phosphoinositide and nuclear factor nB signaling, suggesting specific mechanisms by which BRMS1 may regulate genes involved in the metastatic process (8,9).Despite the potential importance of BRMS1 as a determinant of metastasis in the clinical setting, the study of patient samples from human breast cancer has been hampered by the lack of antibodies to native BRMS1 (6). The recent development of suitable antibodies to BRMS1 now makes it possible to study primar...
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