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Biomedical subjects

Edward R Sauter

Publications and source records attributed to Edward R Sauter.

14 recordsLinked to original sources

Association of kallikrein expression in nipple aspirate fluid with breast cancer risk.

Human kallikreins (hK) 2, 3, 6 and 10 are expressed in breast and prostate tissue. hK2 and hK3 (prostate-specific antigen, PSA) are used to screen for prostate cancer. hK6 and hK10 are downregulated in breast cancer compared to normal breast tissue. We demonstrated that levels of PSA in nipple aspirate fluid (NAF) are lower in women with breast cancer than in normal women. We hypothesize that the expression of hK2, 3, 6 and 10 are related and important in detecting breast cancer. The goals of this study are to determine the level of expression of kallikreins in NAF and serum, the association of hK2, 3, 6 and 10 in NAF, and the association of each of the kallikreins with breast cancer. In NAF from 275 women, hK3, 6 and 10 were detectable in >/= 90% and hK2 in 74% of samples analyzed. NAF levels were highest for hK6 and lowest for hK2, regardless of cancer and menopausal status. hK3 was detectable in 15/29 (52%) and hK2 in 0/29 serum samples collected from 6 women. hK2 and hK3 were concentrated in NAF vs. matched serum. The 4 kallikreins were associated with the exception of hK2 with hK6 or hK10. PSA levels were higher in normal pre- than postmenopausal subjects (but not women with breast cancer), whereas levels of hK2, 6 and 10 did not differ by menopausal status. hK2 and PSA were associated with both pre- and postmenopausal breast cancer; hK6 and 10 were not. hK2 and PSA were more associated with pre- than postmenopausal breast cancer. Using logistic regression, PSA and menopausal status provided the best model of breast cancer prediction, with a sensitivity of 91% and specificity of 39%. In conclusion, 4 kallikreins are expressed in NAF. hK2 and PSA, and hK6 and hK10 are highly associated. Higher premenopausal PSA levels suggest the influence of ovarian steroids. PSA shows the most promise in aiding in the early detection of breast cancer.

Adult↗

Imaging oncogene expression.

In 2003, approximately 39,800 women in the US will die from breast cancer. Mammography and physical examination miss up to 40% of early breast cancers. Moreover, if an abnormality is found, an invasive diagnostic procedure must still be performed to determine if the breast contains atypia or cancer, even though approximately 85% of abnormalities are benign. Scintigraphic imaging of gene expression in vivo by noninvasive means could direct physicians to appropriate targets for intervention at the onset of disease and thereby significantly impact patient management. Until now, no method has been available to image specific overexpressed oncogene mRNAs in vivo by scintigraphic imaging. We hypothesize that gamma-emitting Tc-99m-PNA-peptides can be taken up by human ER+ and ER- breast cancer xenografts, hybridize to complementary mRNA targets in those cells, and concentrate sufficiently in tumor tissue to allow noninvasive imaging of oncogene overexpression. To prepare the probes, peptide analogs of insulin-like growth factor 1 (IGF1) were extended from a solid support by Fmoc coupling. Peptide nucleic acid (PNA) dodecamers antisense to CCND1 and MYC mRNAs were then extended from the N-terminus of IGF1, followed by a chelator peptide, using Fmoc coupling for all residues. The cysteine thiols were cyclized on the solid support, either before or after PNA extension. This simplified synthetic approach allows preparation of a variety of multipeptide disulfide-bridged PNA chimeras. A chelating peptide-PNA chimera antisense to MYC mRNA was then labeled efficiently with Tc-99m, yielding a single product. Tissue distribution studies of antisense and mismatch chimeras at 4 h and 24 h after administration displayed modest accumulation in the liver and kidneys, with appreciable levels in tumors. This result enables testing of Tc-99m-peptide-PNA probes to image gene expression in tumors.

Animals↗

Nipple aspirate fluid expression of urokinase-type plasminogen activator, plasminogen activator inhibitor-1, and urokinase-type plasminogen activator receptor predicts breast cancer diagnosis and advanced disease.

BACKGROUND: Tumor expression of urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and uPA receptor (uPAR) are breast cancer prognostic factors. Less is known about their usefulness in breast cancer diagnosis. Nipple aspirate fluid (NAF) is secreted into the breast duct and collected noninvasively, making it potentially useful both in breast cancer diagnosis and prognosis. We determined the association of uPA, PAI-1, and uPAR levels in NAF with breast cancer (1) detection and (2) advanced disease. METHODS: A total of 88 NAF specimens were collected from women with or without breast cancer, and uPA, PAI-1, and uPAR expression were measured by enzyme-linked immunosorbent assay. RESULTS: uPA and uPAR were independent predictors of cancer presence; uPAR was also an independent predictor of advanced disease stage. Higher PAI-1 expression in breast cancer that was found with univariate analysis was not observed after logistic regression was applied. CONCLUSIONS: NAF evaluation of uPA, uPAR, and, perhaps, PAI-1 (significant only in univariate analysis) may provide useful breast cancer diagnostic and prognostic information.

Adult↗

Ethnic variation in kallikrein expression in nipple aspirate fluid.

Socioeconomic factors cannot entirely explain why black women have an earlier age of breast cancer onset and higher mortality rates, stage for stage, than whites. We and others have shown that prostate-specific antigen [PSA, also known as human kallikrein (hK) 3] is a marker of breast as well as prostate cancer, that hK2 and hK3 are highly homologous at the DNA and protein level and that the level of progesterone, which appears to upregulate hK3, is influenced by ethnicity. We hypothesized that nipple aspiration fluid (NAF) hK2 and hK3 levels are (i) lower in black than white women; (ii) independently associated with breast cancer; (iii) influenced by menopausal status; and (iv) in combination are more informative about whether a woman has breast cancer than either marker alone. NAF was assayed for hK2 and hK3, and the results were stratified by ethnicity, presence or absence of cancer and menopausal status. Statistical analysis was then performed. When stratified by ethnicity, hK2 (p = 0.003) and hK3 (p = 0.027) levels in blacks were lower than in whites. hK2 was lower in premenopausal black than in white subjects, regardless of cancer status. Overall, hK2, hK3 and the ratio hK2/hK3 were lower in subjects with breast cancer than in normal subjects. hK3 was lower in postmenopausal women with breast cancer, regardless of ethnicity. hK2 and hK3 levels were higher in pre- than in postmenopausal whites. Using logistic regression and considering hK2, hK3, hK2/hK3 and ethnicity, hK3 was significantly associated with breast cancer in both pre- (p < 0.001) and postmenopausal women (p = 0.023). In conclusion, whereas hK2, hK3, hK2/hK3 and ethnicity are each significantly associated with breast cancer bivariately, after entering the strongest predictor, hK3, into a logistic regression model, no other variable accounted for additional variation, although this observation is preliminary due to the limited number of black subjects in the study.

Adult↗

Cyclin D1 is a candidate oncogene in cutaneous melanoma.

The retinoblastoma pathway has been implicated in melanoma; however, previous studies of one of the key components of this pathway, cyclin D1 (CD1), failed to find amplification of this gene in a large series of melanomas. We have recently shown that a particular subtype of melanoma, acral melanoma (AM), has frequent amplification of the CD1 locus. This suggested that CD1 might be important in AM and that it may also be important in other melanoma types, even though its copy number may not be altered. We compared CD1 gene copy number and protein expression in 137 invasive primary cutaneous melanomas (71 superficial spreading melanomas, 17 nodular melanomas, 19 lentigo maligna melanomas, 18 AMs, and 12 unclassifiable melanomas) using fluorescence in situ hybridization and immunohistochemistry. We found frequent amplification of CD1 in AM (44.4%) and occasional amplification in lentigo maligna melanoma (10.5%) and superficial spreading melanoma (5.6%). CD1 protein was overexpressed in all cases with amplifications and in an additional 20% of cases without amplification. We tested the importance of CD1 in cell growth in melanoma by using adenovirus-mediated antisense treatment targeted to CD1 in two melanoma cell lines, one with and the other without CD1 amplification and overexpression. Antisense mediated down-regulation of CD1 induced apoptosis in vitro and led to significant tumor shrinkage of melanoma xenografts in severe combined immunodeficient mice. However, it did not alter the growth of normal melanocytes. Together, these results suggest that CD1 may be an oncogene in melanoma and that targeting its expression may be therapeutically beneficial.

Apoptosis↗

Proteomic analysis of nipple aspirate fluid to detect biologic markers of breast cancer.

The early detection of breast cancer is the best means to minimise disease-related mortality. Current screening techniques have limited sensitivity and specificity. Breast nipple aspirate fluid can be obtained noninvasively and contains proteins secreted from ductal and lobular epithelia. Nipple aspirate fluid proteins are breast specific and generally more concentrated than corresponding blood levels. Proteomic analysis of 1 microl of diluted nipple aspirate fluid over a 5-40 kDa range from 20 subjects with breast cancer and 13 with nondiseased breasts identified five differentially expressed proteins. The most sensitive and specific proteins were 6500 and 15 940 Da, found in 75-84% of samples from women with cancer but in only 0-9% of samples from normal women. These findings suggest that (1) differential expression of nipple aspirate fluid proteins exists between women with normal and diseased breasts, and (2) analysis of these proteins may predict the presence of breast cancer.

Adult↗

Prostate-specific antigen and insulin-like growth factor binding protein-3 in nipple aspirate fluid are associated with breast cancer.

Insulin-like growth factor-1 (IGF-1) is an important growth factor for breast cancer cells and insulin-like growth factor binding protein-3 (IGFBP-3) its most prevalent binding protein. Prostate-specific antigen (PSA) enzymatically cleaves IGFBP-3 into fragments (BP3-FR). Our purpose was to determine the association of these markers in nipple aspirate fluid (NAF) and serum with the presence of breast cancer. NAF from 175 and serum from 215 subjects were collected from women with or without breast cancer. In unadjusted analysis low NAFPSA (P < 0.001) and high NAFIGFBP-3 (P = 0.023) were associated with breast cancer. Low serum PSA was associated with postmenopausal breast cancer (P = 0.034). In separate multivariate analyses, controlling for age, menopausal status, and age at menarche, NAF PSA and IGFBP-3 were each associated with breast cancer. The association was significant for NAF IGFBP-3 in all women (P = 0.031), but for NAF PSA only in premenopausal women (P < 0.001). When considered jointly, only NAF PSA was significant. Therefore, NAF PSA, and to a lesser extent NAF IGFBP-3 and serum PSA, seem to be important predictors of breast cancer.

Adult↗

p53 alone or in combination with antisense cyclin D1 induces apoptosis and reduces tumor size in human melanoma.

Melanoma incidence is growing at a faster rate than any other human malignancy. Wild-type (wt) p53 is important in both G(1) and G(2) cell cycle arrest, and cyclin D1 (CD1) is necessary for G(1)-->S progression in melanoma cells. We reported that an adenoviral vector containing wt p53 significantly reduced [(3)H]thymidine uptake in melanoma cells containing mutant but not wt p53. Subsequently we showed that CD1 decreased melanoma proliferation and increased apoptosis. We now extend these findings by evaluating the effect on preformed melanomas of (1) intratumoral therapy with wt p53 alone, (2) wt p53 in combination with antisense (AS) CD1, both short (< or =14 days) and longer term, and (3) doubling the dose or repeat doses of wt p53 or AS CD1. Two melanoma cells lines that metastasize in SCID mice (451 and 1205) were used, one containing a p53 mutation (451) and the other a normal p53 gene sequence (1205). Compared to injection with a control adenoviral vector containing beta-galactosidase (LacZ), intratumoral injection of wt p53 slowed the growth of tumors formed from 451 cells. Using 5 x 10(8) plaque forming units as our standard intratumoral dose, neither doubling the dose of LacZ, p53 or AS CD1, nor repeat doses of the vectors, was as effective as combined therapy with wt p53+AS CD1, which resulted in the shrinkage of all tumors treated and 4/7 (57%) tumors vanished. No tumors treated with wt p53 or AS CD1 alone vanished. Wt p53+AS CD1 treatment resulted in significantly more cells undergoing apoptosis compared to either therapy alone. In summary, combining the separately effective treatment vectors p53 and AS CD1 led to an enhanced growth-suppressive and apoptotic effect, supporting a role for combination gene therapy to treat human malignant melanoma.

Adenoviridae↗

Circulating testosterone and prostate-specific antigen in nipple aspirate fluid and tissue are associated with breast cancer.

Preliminary evidence has associated testosterone and prostate-specific antigen (PSA) with breast cancer. Our objective was to determine whether a) testosterone levels in nipple aspirate fluid (NAF), serum, or breast tissue are associated with breast cancer; b) testosterone levels in serum are associated with levels in NAF; c) PSA in NAF, serum, or breast tissue is associated with breast cancer; and d) serum PSA is associated with NAF PSA levels. We obtained 342 NAF specimens from 171 women by means of a modified breast pump. Additionally, we collected 201 blood samples from 99 women and 51 tissue samples from 41 subjects who underwent surgical resection for suspected disease. Women currently using birth control pills or hormone replacement therapy were excluded from the study. Controlling for age and menopausal status, serum testosterone was significantly increased in women with breast cancer (p = 0.002). NAF and serum testosterone levels were not associated. Neither NAF nor tissue testosterone was associated with breast cancer. Controlling for menopausal status and age, NAF PSA was significantly decreased in women with breast cancer (p < 0.001). We did not find serum PSA to be associated with breast cancer, although we found an indication that, in postmenopausal women, its levels were lower in women with cancer. Serum PSA was associated with NAF PSA in postmenopausal women (p < 0.001). PSA levels in cancerous tissue were significantly lower than in benign breast specimens from subjects without cancer (p = 0.011), whereas levels of PSA in histologically benign specimens from subjects with cancer were intermediate. Our results suggest that serum testosterone is increased and NAF PSA is decreased in women with breast cancer, with PSA expression being higher in normal than in cancerous breast tissues. NAF and serum PSA levels in postmenopausal women are correlated, suggesting that as laboratory assessment of PSA becomes more sensitive, serum PSA may become useful in identifying women with breast cancer.

Adult↗

Association of uPA, PAT-1, and uPAR in nipple aspirate fluid (NAF) with breast cancer.

PURPOSE: Urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor (PAI-1), and uPA receptor (uPAR) are prognostic factors in various cancer types, especially breast cancer. Less is known about the usefulness of these markers in breast cancer diagnosis. We sought to determine (1) whether uPA, PAI-1, and uPAR were detectable in breast nipple aspirate fluid (NAF), a physiologic fluid produced by the breast and collected noninvasively, and (2) the association of these markers in NAF with the presence of breast cancer. PATIENTS AND METHODS: One hundred twenty NAF specimens were collected from women with and women without breast cancer. uPA, PAI-1, and uPAR expression in NAF was measured by enzyme-linked immunosorbent assay. RESULTS: Median NAF PAI-1, but not uPA or uPAR, expression was higher in subjects with breast cancer than in those without breast cancer, regardless of whether expression was controlled for total NAF protein level. Median expression of PAI-1 per milligram of total NAF protein was higher in both premenopausal and postmenopausal women who had breast cancer than in women who did not. A multiple logistic regression model that included age, race, menopausal status, uPA, PAI-1, and uPAR level to differentiate patients with regard to cancer risk revealed that uPA, PAI-1, and age were each associated with risk (P < or = 0.019). Women whose NAF contained elevated uPA and PAI-1 levels were more likely to have cancer than women in whom both markers were not elevated. DISCUSSION: Our data suggest that PAI-1, alone or in combination with uPA, may be useful as a noninvasive biologic marker to aid in the detection of breast cancer.

Biomarkers, Tumor↗