Combined BRCA2 and MAGEC3 Expression Predict Outcome in Advanced Ovarian Cancers

Like BRCA2, MAGEC3 is an ovarian cancer predisposition gene that has been shown to have prognostic significance in ovarian cancer patients. Despite the clinical significance of each gene, no studies have been conducted to assess the clinical significance of their combined expression. We therefore sought to determine the relationship between MAGEC3 and BRCA2 expression in ovarian cancer and their association with patient characteristics and outcomes. Immunohistochemical staining was quantitated on tumor microarrays of human tumor samples obtained from 357 patients with epithelial ovarian cancer to ascertain BRCA2 expression levels. In conjunction with our previously published MAGEC3 expression data, we observed a weak inverse correlation of MAGEC3 with BRCA2 expression (r = −0.15; p < 0.05) in cases with full-length BRCA2. Patients with optimal cytoreduction, loss of MAGEC3, and detectable BRCA2 expression had better overall (median OS: 127.9 vs. 65.3 months, p = 0.035) and progression-free (median PFS: 85.3 vs. 18.8 months, p = 0.002) survival compared to patients that were BRCA2 expressors with MAGEC3 normal levels. Our results suggest that combined expression of MAGEC3 and BRCA2 serves as a better predictor of prognosis than each marker alone.

The Role of Castration-Resistant Bmi1+Sox2+ Cells in Driving Recurrence in Prostate Cancer

BACKGROUND

Recurrence following androgen-deprivation therapy is associated with adverse clinical outcomes in prostate cancer, but the cellular origins and molecular mechanisms underlying this process are poorly defined. We previously identified a population of castration-resistant luminal progenitor cells expressing Bmi1 in the normal mouse prostate that can serve as a cancer cell-of-origin. Here, we investigate the potential of Bmi1-expressing tumor cells that survive castration to initiate recurrence in vivo.

METHODS

We employed lineage retracing in Bmi1-CreER; R26R-confetti; Ptenf/f transgenic mice to mark and follow the fate of emerging recurrent tumor clones after castration. A tissue recombination strategy was used to rescue transgenic mouse prostates by regeneration as grafts in immunodeficient hosts. We also used a small molecule Bmi1 inhibitor, PTC-209, to directly test the role of Bmi1 in recurrence.

RESULTS

Transgenic prostate tumors (n = 17) regressed upon castration but uniformly recurred within 3 months. Residual regressed tumor lesions exhibited a transient luminal-to-basal phenotypic switch and marked cellular heterogeneity. Additionally, in these lesions, a subpopulation of Bmi1-expressing castration-resistant tumor cells overexpressed the stem cell reprogramming factor Sox2 (mean [SD] = 41.1 [3.8]%, n = 10, P < .001). Bmi1+Sox2+ cells were quiescent (BrdU+Bmi1+Sox2+ at 3.4 [1.5]% vs BrdU+Bmi1+Sox2- at 18.8 [3.4]%, n = 10, P = .009), consistent with a cancer stem cell phenotype. By lineage retracing, we established that recurrence emerges from the Bmi1+ tumor cells in regressed tumors. Furthermore, treatment with the small molecule Bmi1 inhibitor PTC-209 reduced Bmi1+Sox2+ cells (6.1 [1.4]% PTC-209 vs 38.8 [2.3]% vehicle, n = 10, P < .001) and potently suppressed recurrence (retraced clone size = 2.6 [0.5] PTC-209 vs 15.7 [5.9] vehicle, n = 12, P = .04).

CONCLUSIONS

These results illustrate the utility of lineage retracing to define the cellular origins of recurrent prostate cancer and identify Bmi1+Sox2+ cells as a source of recurrence that could be targeted therapeutically.

Subsequent breast and high grade serous carcinomas after risk-reducing salpingo-oophorectomy in BRCA mutation carriers and patients with history of breast cancer

Risk-reducing salpingo-oophorectomy (RRSO) is a procedure to reduce the risk of adnexal cancer in BRCA mutation carriers and for hormonal manipulation in women with breast cancer (BC). The goal of the study is to report the frequency of subsequent BC and high-grade serous carcinoma (HGSC) following RRSO in BRCA1 and BRCA2 mutation carriers and in patients with personal history of BC with or without BRCA mutation. A series of 147 consecutive patients who received a RRSO were reviewed. Patient's age, clinical history, BC histotype, gene mutation data, incidence of post-RRSO BC and HGSC and time intervals were analyzed. The cases were followed for a mean of 49 months. Group 1 consists of 97 cases with pathogenic or likely pathogenic "deleterious" mutation BRCA1 (n = 49) or BRCA2 (n = 48). Group 2 consists of 50 cases with history of BC and no documented BRCA gene mutation. Prior to RRSO, 42 (43%) cases in group 1 had a history of BC and all cases in group 2 had a history of BC. There was no difference between the groups in the age at diagnosis for BC (Mean of 44 years). Following RRSO, 2/49 cases (4%) with BRCA1 mutation were found to have occult HGSC and none in BRCA2 cases. There were also 1 BC recurrence and 1 primary BC with BRCA1 mutation compared to 5 recurrent BC in Group 2 (10%). In conclusion, the risk of subsequent recurrent BC after RRSO appears to be higher (10%) in patients with history of BC with no BRCA mutation when compared to (2%) in BRCA mutation carriers.

Trends in High-Grade Cervical Cancer Precursors in the Human Papillomavirus Vaccine Era

INTRODUCTION

The 2006 introduction of human papillomavirus vaccine targeted against genotypes 6, 11, 16, and 18 should result in decreased cervical dysplasia in vaccinated women. However, new cervical cancer guidelines to increase screening intervals complicate interpretation of trends. The hypothesis is that cervical dysplasia would decrease only in young vaccine-eligible women, and not older women.

METHODS

The authors identified Davidson County, Tennessee, women aged 18-39 years with cervical intraepithelial neoplasia (CIN) grade 2 or greater and adenocarcinoma in situ, denoted as CIN2+, through pathology reports from laboratories serving this population. Biopsy specimens for human papillomavirus genotyping were collected. Trends in CIN2+ rates and associated human papillomavirus genotypes, 2008 through 2013, were examined.

RESULTS

The authors identified 2,031 women with CIN2+. Rates of CIN2+ fell from 188.9 to 58.7 per 100,000 women aged 18-20 years (annual percentage change= -24.2, 95% CI= -41.4, -2.1) and from 495.6 to 332.4 per 100,000 women aged 21-24 years (annual percentage change= -10.2%, 95% CI= -16.3, -3.4). There was no significant change in CIN2+ rates for women aged 25-29 or 30-39 years. In biopsy specimens from 1,319 of 2,031 (65%) women, at least one human papillomavirus genotype was identified in 1,270 (96%). The prevalence of at least one of four vaccine human papillomavirus genotypes (6, 11, 16, and 18) declined from 59% in 2008 to 52% in 2013 (p=0.003).

CONCLUSIONS

Diagnosis of CIN2+ decreased in women aged 18-24 years, but not in older women. Both changes in screening and human papillomavirus vaccination could have contributed to the decline of CIN2+ in young women.

Abstract LB-046: Castration-resistant Bmi1+Sox2+ cells drive recurrence in prostate cancer

Introduction: Recurrence is associated with mortality in prostate cancer, but the cellular origins and molecular mechanisms that drive this process have not been well-defined. An emerging model of resistance to androgen deprivation therapy (ADT) in prostate cancer, particularly to the more potent newer drugs, involves lineage plasticity or transdifferentiation. Epigenetic regulators and stem cell reprogramming factors including Sox2 and Ezh2 appear to play important roles in this process. However, there has been a paucity of studies that attempt to specifically follow the fate of malignant prostate cells in regressed tumors following castration in order to understand the cellular processes associated with the emergence of castration-resistant prostate cancer (CRPC). We recently identified a population of luminal progenitors termed castration-resistant Bmi1-expressing cells (CARBs) in the mouse prostate that serve as a prostate cancer cell of origin. Here, we hypothesized that analogous castration-resistant Bmi1-expressing tumor cells (tumor CARBs) exist in prostate cancer and could seed recurrence after ADT. Methods: We adopted lineage retracing strategies using an inducible Bmi1-CreER driver and a multicolor reporter R26R-Confetti allele, which enables lineage-marking and kinetically re-tracing of the emerging recurrent tumor clones within castrated tumors over times in vivo. A tissue recombination strategy was used to rescue transgenic Bmi1-CreER; Ptenf/f mice (BC-Pten) mouse prostates by regeneration as grafts in SCID mice. The ability of tumor CARBs to seed recurrence was determined by lineage retracing methodology of castrated mice after establishing tumor by tamoxifen treatment, which was coupled with immunohistochemistry and Western blotting. We also used a small molecule Bmi1 inhibitor, PTC-209, to directly test the role of Bmi1 in recurrence. Results: Deletion of Pten in Bmi1+ luminal prostate progenitors generates a luminal prostate cancer that regresses upon castration, followed by recurrence over time. Notably, castration induced a transient luminal-to-basal phenotypic switch in regressed tumors with recurrent tumors reverting to a luminal phenotype. Analysis of regressed tumors post-castration showed cellular heterogeneity, with a population of apoptosis-resistant, proliferative, Bmi1-expressing tumor cells that also upregulate expression of the stem cell reprogramming factor Sox2. Expression of Sox2 was maintained in recurrent tumors despite loss of basal cell transdifferentiation. Lineage re-tracing with the R26R-Confetti allele established that Bmi1+ tumor cells in regressed tumors drive recurrence. Furthermore, treatment with the small molecule Bmi1 inhibitor PTC-209 eliminated Bmi1+Sox2+ cells and significantly decreased recurrence. Conclusion: These results shed light on the cellular origins of recurrent prostate cancer and the roles of the epigenetic/stem cell regulators Bmi1 and Sox2 in therapeutic resistance to androgen deprivation.

Citation Format: Young A. Yoo, Rajita Vatapalli, Barbara Lysy, Hanlin Mok, Mohamed M. Desouki, Sarki A. Abdulkadir. Castration-resistant Bmi1+Sox2+ cells drive recurrence in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-046.

Characteristic findings of cervical Papanicolaou tests from transgender patients on androgen therapy: Challenges in detecting dysplasia

INTRODUCTION

The characteristic features of Papanicolaou (Pap) tests collected from female-to-male (FTM) transgender patients on androgen therapy have not been well defined in the literature. FTM transgender patients require cervical cancer screening with the same recommended frequency as cis-gender females. Dysplasia remains challenging to differentiate from atrophy. Without pertinent history, the atrophic findings in younger transgender patients can be misinterpreted as high-grade dysplasia.

METHODS

A review of all cervical Pap tests of transgender patients receiving androgen therapy (2010-2017) was performed. Bethesda diagnosis, cytomorphological features, HPV testing and cervical biopsy results were reviewed.

RESULTS

Eleven transgender patients receiving androgen therapy were identified with 23 cervical Pap tests, 11 HPV tests and five cervical biopsies performed. A review of the Pap tests demonstrated: 57% negative for intraepithelial lesion; 13% unsatisfactory; 13% atypical squamous cells of undetermined significance; 13% atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion; and 4% high-grade squamous intraepithelial lesion. The rates of abnormal tests were higher than our age-matched cis-gender atrophic cohort rates of unsatisfactory (0.5%), atypical squamous cells of undetermined significance (7%), atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (0%) and high-grade squamous intraepithelial lesion (0.5%). The cytological findings from liquid-based preparations included dispersed and clustered parabasal-type cells, scattered degenerated cells, smooth evenly dispersed chromatin, and occasional mild nuclear enlargement and irregularity. Dysplastic cells had larger nuclei, hyperchromatic clumped chromatin, and more irregular nuclear contours.

CONCLUSIONS

The evaluation of dysplasia can be challenging on Pap tests from transgender patients on androgen therapy. The cohort evaluated had higher rates of unsatisfactory and abnormal Pap tests. Pathologists should be familiar with the distinctive cytomorphological changes in the Pap tests from patients on androgen therapy to evaluate them appropriately.

The role of skin ulceration in breast carcinoma staging and outcome

Breast carcinoma with skin ulceration (SU) is considered a locally advanced disease. The purpose of the study is to investigate if SU is an independent adverse factor. Breast carcinoma patients with SU (n=111) were included in the study. A subset (n=38, study cohort) was matched with cases that had no SU (n=38, matched cohort); the survival analyses were compared between these groups. Then, cases (n=80) were staged independent from SU into stage I, II or III. Disease free survival (DFS) and overall survival (OS) were analyzed. Patients with larger tumors tended to present with distant metastases more often than patients with smaller tumors (P=.004). In the matched cases, the 5-year DFS probability was 53% for the study cohort and 58% for the matched cohort; and for OS 75% for the study cohort and 84% for the matched cohort with no statistical significant difference. However, there was a trend towards worse DFS for the patients whose tumors had SU. When the cases were staged based on tumor size and node status (I, II or III), the OS was statistically significant (P=.047) but not the DFS (P=.195). Relatively small tumors with SU had an extent of disease similar to that observed in patients with early stages disease. The survival analysis suggests that SU may not be an adverse factor. However, more cases are needed to further examine this finding.

Atypical mucinous glandular proliferations in endometrial samplings: follow-up and other clinicopathological findings in 41 cases

The 2014 World Health Organization classification calls for endometrial mucinous proliferations that display "confluent or cribriform architecture with even minimal atypia" in sampling specimens to be classified as carcinoma, and others whose features are not diagnostic of carcinoma to be categorized as atypical mucinous glandular proliferations (AMGPs). Herein, we evaluate follow-up findings in 41 cases that were classified as AMGP from our files. The average patient age was 46years (range, 37-59 years). Postbiopsy follow-up duration ranged from 15 to 109weeks (mean, 40 weeks). There was no follow-up resection in 12 patients (9 with repeat biopsies, all 9 with no clinical evidence of disease, mean follow-up of 43weeks), and 29 patients underwent a hysterectomy an average of 2.4months after the index biopsy. The distribution of pathologic findings in the uteri was as follows: no residual AMGP or carcinoma (5/29; 17%), AMGP (11/29; 38%), and adenocarcinoma (13/29; 45%). All adenocarcinomas were grade I and stage I, and histotypes were endometrioid (n=8), mucinous (n=3), and endometrioid with mucinous differentiation (n=2). Only 3 (23%) carcinomas were myoinvasive, of which 1 case, a mucinous carcinoma with a 40% endometrioid component, showed greater than 50% myometrial invasion. None of a wide array of morphologic features was significantly associated with a hysterectomy diagnosis of carcinoma (versus AMGP) on univariate analyses. In conclusion, our cohort of AMGP represents a biologically variable spectrum of lesions that includes mucinous hyperplastic proliferations as well as endometrioid and mucinous adenocarcinomas that are occasionally myoinvasive. Morphologic features that optimally stratified AMGP cases into clinically relevant subgroups were not identified.

Bmi1 marks distinct castration-resistant luminal progenitor cells competent for prostate regeneration and tumour initiation

Identification of defined cell populations with stem/progenitor properties is key for understanding prostate development and tumorigenesis. Here we show that the polycomb repressor protein Bmi1 marks a population of castration-resistant luminal epithelial cells enriched in the mouse proximal prostate. We employ lineage tracing to show that these castration-resistant Bmi1-expressing cells (or CARBs) are capable of tissue regeneration and self-renewal. Notably, CARBs are distinct from the previously described luminal castration-resistant Nkx3.1-expressing cells (CARNs). CARBs can serve as a prostate cancer cell-of-origin upon Pten deletion, yielding luminal prostate tumours. Clonal analysis using the R26R-confetti allele indicates preferential tumour initiation from CARBs localized to the proximal prostate. These studies identify Bmi1 as a marker for a distinct population of castration-resistant luminal epithelial cells enriched in the proximal prostate that can serve as a cell of origin for prostate cancer.

The polycomb repressor protein Bmi1 has a role in self-renewal and tumorigenesis. Here, the authors use lineage tracing to show that Bmi-expressing cells are a distinct population of cells, primarily found in the luminal compartment, which is castration resistant, can initiate cancer and regenerate prostate.

Incidental placenta increta at the time of prophylactic hysterectomy for Lynch syndrome: Insights into individualized decision-making and surgical timing

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Increta in a prophylactic hysterectomy specimen for Lynch syndrome is rare.

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Individualizing risk-reducing procedures after childbearing is important.

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Shared decision making should include the timing of prophylactic surgery.

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Minimizing surgical risks in the postpartum period should be discussed.

The risk of upgrade for atypical ductal hyperplasia detected on magnetic resonance imaging-guided biopsy: a study of 100 cases from four academic institutions

AIMS

To identify variables that can predict upgrade for magnetic resonance imaging (MRI)-detected atypical ductal hyperplasia (ADH).

METHODS AND RESULTS

We reviewed 1655 MRI-guided core biopsies between 2005 and 2013, yielding 100 (6%) cases with ADH. The pathological features of ADH and MRI findings were recorded. An upgrade was considered when the subsequent surgical excision yielded invasive carcinoma (IC) or ductal carcinoma in situ (DCIS). The rate of ADH between institutions was 3.3-7.1%, with an average of 6%. A total of 15 (15%) cases had upgrade, 12 DCIS and three IC. When all cases were included, only increased number of involved cores was statistically significant (P = 0.02). When cases with concurrent lobular neoplasia (LN) were excluded (n = 14), increased number of ADH foci and increased number of involved cores were statistically significant (P = 0.002, P = 0.009). We analysed the data separately from a single institution (n = 61). Increased number of foci, increased number of total cores and involved cores and larger ADH size predicted upgrade with statistical significance.

CONCLUSIONS

The incidence of ADH in MRI-guided core biopsy is rare. The rate of upgrade is comparable to mammographically detected ADH, warranting surgical excision. Similar to mammographically detected lesions, the volume of the ADH predicts the upgrade.

An immunohistochemical analysis of stathmin 1 expression in uterine smooth muscle tumors: differential expression in leiomyosarcomas and leiomyomas

The oncogenic phosphatidylinositol 3-kinase-AKT-mammlian target of rapamycin pathway (PI3K-AKT-mTOR) pathway is known to be activated in uterine smooth muscle tumors, and Stathmin 1 (STMN1) expression has been identified as a marker of PI3K-AKT-mTOR pathway activation. We hypothesized that STMN1 may have some diagnostic utility and explored how well STMN1 expression correlated with histologic classifications of uterine smooth muscle tumors into benign and malignant groupings. 84 smooth muscle tumors were assessed for STMN1 expression by immunohistochemistry. These included spindle cell leiomyosarcoma (n=32), conventional spindle cell leiomyomas (n=30), atypical (symplastic) leiomyoma (n=5), cellular leiomyoma (n=7), smooth muscle tumor of uncertain malignant potential (n=4), mitotically active leiomyomas (n=2), benign metastasizing leiomyoma (n=3), and cotyledonoid dissecting leiomyoma (n=1). All spindle cell leiomyosarcomas were positive (32/32 positive; 100%) as compared with conventional leiomyomata (11/30; 37%) (P<0.0001). The average immunohistochemical score (0-12+, reflective of intensity and extent) for leiomyosarcomas was 8.7 (±1.43) whereas the conventional leiomyomata average score was 1.6 (±1.07) (P<0.0001). This difference in scores was reflected in the patterns of expression: leiomyosarcomas were predominantly strongly and diffusely positive whereas leiomyomata were predominantly weakly, albeit diffusely positive when expression was present. The sensitivity of STMN1 expression for leiomyosarcomas was 100%. However, the specificity was found to be only 55% (CI=43-68%). The negative and positive predictive values for leiomyosarcomas were 100% and 52% respectively. The odds ratio (OR) for any STMN1 expression in predicting a spindle cell leiomyosarcoma diagnosis from this dataset was highly significant (OR=144, P=0.0006). Thirteen non-smooth muscle tumors that involved the uterus all showed at least focal STMN1 immunoreactivity. In summary, STMN1 is a highly sensitive marker for leiomyosarcoma but is suboptimally specific for diagnostic purposes. The 100% negative predictive value for leiomyosarcoma may offer some diagnostic utility in a small sample, since the absence of STMN1 immunoreactivity in a putative leiomyosarcoma is a strong argument against this diagnostic possibility.

Pleomorphic lobular carcinoma in situ of the breast: clinicopathological review of 47 cases

AIMS

Pleomorphic lobular carcinoma in situ (PLCIS) of the breast is a distinctive entity, but its behaviour and management are unclear. The purpose of this study was to review a relatively large number of cases and to evaluate the risk of recurrence.

METHODS AND RESULTS

Cases of PLCIS (n = 47) from a 12-year period were reviewed. The clinical, radiological and pathological findings were recorded. Immunohistochemistry for oestrogen receptor (ER), progesterone receptor (PR) and HER2 was performed. Thirty-one patients had no concurrent breast cancer or past history of breast cancer, and six (19.4%) of these had local recurrence; all tumours (four invasive carcinoma and two PLCIS) were ipsilateral. Younger age at presentation was a risk factor for local recurrence: patients with recurrence had a mean age (range) of 52.5 years (44-59 years), versus 60.6 years (40-81 years) for those without (P = 0.03). Three of 31 patients were treated with radiation therapy (RT), and none of these developed local recurrence. PLCIS had an adverse ER/PR/HER2 molecular profile, with at least 41.2% of the cases overexpressing HER2. Moreover, at least 11.7% of the cases were triple-negative.

CONCLUSIONS

This study included the largest number of patients who had no concurrent breast cancer or past history of breast cancer with the longest clinical follow-up, providing insights into management practices for PLCIS and the risk of recurrence.

Utility of α-methylacyl-coenzyme-A racemase (p504s) immunohistochemistry in distinguishing endometrial clear cell carcinomas from serous and endometrioid carcinomas

The expression of α-methylacyl-coenzyme-A racemase (AMACR) has previously been reported in 75% to 100% of urethral/bladder clear cell carcinomas, tumors that are known to display broad phenotypic overlap with their identically named müllerian counterparts. Herein, we assess the utility of AMACR in distinguishing endometrial clear cell carcinomas (CCCs) from endometrial serous carcinomas (ESCs) and endometrial endometrioid carcinomas (EECs). A total of 111 endometrial carcinomas in a tissue microarray, including 49 CCCs, 13 ESCs, and 49 EECs, were assessed for AMACR immunoreactivity, with results scored semiquantitatively (scores 0, 1+, 2+, 3+ for 0%, 1%-5%, 6%-50%, >50% immunoreactive cells, respectively). Fifty (45%) of the 111 carcinomas were AMACR positive, with the following score distribution: CCC: 0 (n = 12), 1+ (n = 12), 2+ (n = 3), 3+ (n = 22); EEC: 0 (n = 38), 1+ (n = 4), 2+ (n = 4), 3+ (n = 3); ESC: 0 (n = 11), 1+ (n = 1), 2+ (n = 0), 3+ (n = 1). AMACR expression was significantly more frequent in CCC (75%) than in ESC (15%) or EEC (22%); P < .0001. The sensitivity and specificity of AMACR expression in classifying a carcinoma as CCC were 0.75 (95% confidence interval [CI], 0.61-0.86) and 0.79 (95% CI, 0.66-0.88), respectively, with an odds ratio of 11.62 (95% CI, 5-28; P < .001) and an area under the curve of 0.79 (95% CI, 0.68-0.88). These findings indicate that AMACR expression is strongly associated with CCC and displays a relatively robust diagnostic test performance. However, its practical utility may be limited by the focal nature of its expression in 32% of the AMACR-positive CCC cases as well as its expression in 15% to 22% of the non-CCC histotypes.

The clinicopathologic significance of p53 and BAF-250a (ARID1A) expression in clear cell carcinoma of the endometrium

TP53 mutation (and associated p53 protein overexpression) is probably a negative prognostic marker in endometrial cancers, but its relevance in the rarer histologic subtypes, including clear cell carcinomas, has not been delineated. Preclinical studies suggest functional interactions between p53 and the BAF250a protein, the product of a tumor suppressor gene ARID1A (adenine-thymine (AT)-rich interactive domain containing protein 1A) that is frequently mutated in ovarian clear cell carcinoma. In this study, we evaluated the significance of p53 and BAF250a expression, as assessed by immunohistochemistry, in a group of 50 endometrial clear cell carcinomas. Of 50 cases, 17 (34%) were p53+, and the remaining 33 cases had a p53 wild-type (p53-wt) immunophenotype. Of the 11 relapses/recurrences in the entire data set, 73% were in the p53+ group (P=0.008). On univariate analyses, the median overall survival for the p53-wt patients (83 months) was longer than the p53+ patients (63 months) (P=0.07), and the median progression-free survival for the p53-wt group (88 months) was significantly longer than the p53+ group (56 months) (P=0.01). On multivariate analyses, p53 expression was not associated with reduced overall or progression-free survival. In addition, p53 status was not significantly associated with pathologic stage or morphologic patterns. Of the 50 cases, 10 (20%) showed a complete loss of BAF250a expression. There was no significant correlation between p53 and BAF250a expression. The p53+/BAF250a-, p53+/BAF250a+, p53-wt/BAF250a+ and p53-wt/BAF250a- composite immunophenotypes were identified in 8%, 26%, 54% and 12% of cases, respectively, and neither loss of BAF250a expression nor composite p53/BAF250a expression patterns were associated with reduced overall or progression-free survival. In conclusion, a significant subset of CCC express p53, and these cases are apparently not definable by their morphologic features. P53 expression may be a negative prognostic factor in this histotype, and warrants additional studies. Loss of BAF250a expression has no prognostic significance in endometrial clear cell carcinomas.

Coordinate patterns of estrogen receptor, progesterone receptor, and Wilms tumor 1 expression in the histopathologic distinction of ovarian from endometrial serous adenocarcinomas

The purpose of this study is to assess whether composite or coordinate immunoexpression patterns of estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor 1 (WT1) gene can significantly distinguish between endometrial serous carcinoma (ESC) and ovarian serous carcinoma (OSC). Immunohistochemical analyses were performed on whole tissue sections from 22 uterus-confined ESCs and on a tissue microarray of 140 high-grade, pan-stage OSCs, using antibodies to ER, PR, and WT-1. Estrogen receptor, PR, and WT1 expressions were present in 37%, 49%, and 81% of OSC, respectively, but these markers were also present in 18%, 27%, and 36% of ESC. The ER+/PR+/WT1+ coordinate profile was identified in 33.6% of OSC but in none of ESC (P = .0006), resulting in a calculated sensitivity and specificity of this profile for OSC of 33.6% and 100%, respectively. By contrast, the ER-/PR-/WT1- coordinate profile was identified in 41% of ESC but in only 6.4% of OSC (P = .0001), resulting in a calculated sensitivity and specificity of this profile for ESC of 50% and 94%. In summary, in the differential diagnosis between OSC and ESC, positivity for all 3 markers favors an extrauterine origin, whereas negativity for all 3 markers is supportive of an endometrial origin. The use of single markers for this purpose is not recommended, as each lacks optimal discriminatory power. Coordinate profiles, in general, have a high specificity but low sensitivity in this differential diagnosis.

Incidental atypical proliferative lesions in reduction mammoplasty specimens: analysis of 2498 cases from 2 tertiary women's health centers

Atypical proliferative lesions (APLs) are occasionally found in breast reduction specimens. The aim of the study was to investigate the prevalence of APL in reduction mammoplasty specimens from patients who were treated mainly for macromastia. A retrospective medical record review of pathology records on patients who underwent reduction mammoplasty from 2006 to 2012 generated 2498 cases. The sole exclusion criterion was a history of invasive and/or ductal carcinoma in situ (DCIS). Laterality, specimen weight, number of blocks submitted, and presence of APL were recorded and analyzed. We defined APL as invasive carcinoma, DCIS or lobular carcinoma in situ, atypical ductal (ADH) or lobular hyperplasia, and flat epithelial atypia (FEA). The presence of papillomas, radial scars, and fibroadenomas was also recorded. At least 1 APL was identified in 107 (4.3%) of 2498 reduction mammoplasty specimens including invasive duct carcinoma (n = 2), DCIS (n = 4), ADH/FEA (n = 47), and lobular carcinoma in situ/atypical lobular hyperplasia (n = 54). One hundred four (97%) of the 107 patients underwent bilateral, and 3 (3%) underwent unilateral reductions. In conclusion, the frequency of detection of APLs in patients with no history of breast cancer is low (4.3%). Detection of invasive and DCIS lesions is extraordinarily low at 0.2%. The most common APL is lobular neoplasia (2.2%), whereas ADH and FEA are seen in 1.9%. Our findings provide data on the distribution of these lesions in this setting, as well as some insight into their prevalence in the general population. A protocol for submitting tissues from these specimens is also proposed.

Expression of the oncofetal protein IGF2BP3 in endometrial clear cell carcinoma: assessment of frequency and significance

Insulin-like growth factor-II messenger RNA-binding protein 3 (IGF2BP3 or IMP3) is a biomarker whose expression has been found to be a negative prognostic factor in several neoplasms including ovarian clear cell carcinoma (CCC). In this study, we analyzed the frequency and clinicopathologic significance of IMP3 expression, as assessed by immunohistochemistry and as scored using a modified H-score system, in a cohort of 50 endometrial CCCs. Cases with scores of 0 to 100, 101 to 200, and 201 to 300 were classified as negative/mildly positive (n = 17), moderately positive (n = 20), and strongly positive (n = 13), respectively. A distinctive pattern of increased staining at the myoinvasive front (relative to the main tumor) was evident in 46% of the cases with evaluable foci of myometrial invasion. Moderate/strong IMP3 staining was associated with a tumor architectural pattern that has been reported to be of poor prognostic significance: at least 10% of the tumor composed of solid architecture or individual infiltrating tumor cells (P = .01). Increasing levels of IMP3 expression showed a trend toward decreasing relapse-free survival (RFS; median survival, 75.6, 81.3, and 48.4 months for the negative/mildly, moderately, and strongly positive groups, respectively [P = .09]). However, IMP3 expression was not significantly associated with reduced overall survival or RFS in a multivariate analytic model. The finding in a subset of our cases of increased IMP3 expression at the tumoral myoinvasive front is consistent with a role for IMP3 in invasiveness, as is the trend toward reduced RFS in cases expressing IMP3 at high levels. These preliminary findings suggest that IMP3 expression may be involved in the pathogenesis of CCC and is worthy of further exploration.

Morphologic and other clinicopathologic features of endometrial clear cell carcinoma: a comprehensive analysis of 50 rigorously classified cases

Clear cell carcinoma of the endometrium (CCC) is an uncommon histotype whose analyses have generally been hampered by its rarity and issues of interobserver diagnostic variability. In this study, we analyzed the clinicopathologic features of 50 CCCs that were assembled from multiple institutions and which we considered to be morphologically unambiguous after a rigorous review process for diagnostic accuracy. Forty-four (88%) of the 50 CCC cases showed an admixture of the classic architectural patterns (glandular, papillary, solid and cystic in decreasing order of prevalence). Mitotic indices were variable but were generally low: 60% of cases had a mitotic index of 3 or lower. The predominant cell type lining glands and papillae was invariably hobnail and/or cuboidal. Stratification of nuclei (greater than 3 cells) or columnar cells on glands and papillae were uncommon and never diffusely present. 82% of cases showed an admixture of polygonal cells with clear and eosinophilic cytoplasm; only clear cells were present in 4% and only eosinophilic cells were present in 10%. Hobnail cells were common, being identifiable in 86% of cases, and being diffuse in 60%. Only 2 cases had a predominance of nuclear grade 3 cells. Psammoma, hyaline and targetoid bodies were identified in 32%, 52% and 20% of cases respectively. Clear cell endometrial intraepithelial carcinoma was identified in 41.7% of cases with evaluable background endometrium. The 5-year progression free survival (PFS) for the entire cohort was 61%, and was 88%, 75%, 22% and 28.6% for stages I to IV respectively. On univariate analyses, age >65 years, advanced FIGO stage, and the presence of any lymph node metastases were associated with reduced PFS (p=0.02, 0.002, and 0.002 respectively). On multivariate analyses, the only variable associated with reduced PFS was age >65 years. The 5-year overall survival (OS) for the entire cohort was 78%, and was 94%, 87.5%, 66.7%, and 42.8% for stages I to IV respectively. On univariate analyses, the following factors were associated with reduced OS: age >65 years (p=0.04), advanced FIGO stage (p=0.003), distant metastases (p=0.003), myometrial invasion >30% (p=0.01), a mitotic index >4 (p=0.014), and a specific architectural pattern (at least 10% of the tumor composed of solid masses or individual infiltrating tumor cells, p=0.02). On multivariate analyses, only age >65 years and advanced stage were associated with reduced OS (p=0.023 and 0.022 respectively). In summary, endometrial CCC has a wide morphologic spectrum that is detailed and illustrated herein, but also has core cytoarchitectural features that are of high diagnostic utility. Morphologically unambiguous CCC apparently have patient outcomes that are more favorable than has previously been reported, indicating that ambiguous tumors should be classified separately. The existence of morphologically ambiguous clear-cell rich carcinomas that do not fit the conventional histotypic groupings, is a likely reflection of the biologic complexity of endometrial carcinomas in general; these cases should be reported descriptively, and studied separately from conventional CCC.

Differential copy number aberrations in novel candidate genes associated with progression from in situ to invasive ductal carcinoma of the breast

Only a minority of intraductal carcinomas of the breast give rise to stromally invasive disease. We microdissected 206 paraffin blocks representing 116 different cases of low-grade ductal carcinoma in situ (DCIS). Fifty-five were pure DCIS (PD) cases without progression to invasive carcinoma. Sixty-one cases had a small invasive component. DNA was extracted from microdissected sections and hybridized to high-density bacterial artificial chromosome arrays. Array comparative genomic hybridization analysis of 118 hybridized DNA samples yielded data on 69 samples that were suitable for further statistical analysis. This cohort included 20 pure DCIS cases, 25 mixed DCIS (MD), and 24 mixed invasive carcinoma samples. PD cases had a higher frequency of DNA copy number changes than MD cases, and the latter had similar DNA profiles compared to paired invasive carcinomas. Copy number changes on 13 chromosomal arms occurred at different rates in PD versus MD lesions. Eight of 19 candidate genes residing at those loci were confirmed to have differential copy number changes by quantitative PCR. NCOR2/SMRT and NR4A1 (both on 12q), DYNLRB2 (16q), CELSR1, UPK3A, and ST13 (all on 22q) were more frequently amplified in PD. Moreover, NCOR2, NR4A1, and DYNLRB2 showed more frequent copy number losses in MD. GRAP2 (22q) was more often amplified in MD, whereas TAF1C (16q) was more commonly deleted in PD. A multigene model comprising these candidate genes discriminated between PD and MD lesions with high accuracy. These findings suggest that the propensity to invade the stroma may be encoded in the genome of intraductal carcinomas.

Mechanisms and functional consequences of PDEF protein expression loss during prostate cancer progression

BACKGROUND

Ets is a large family of transcriptional regulators with functions in most biological processes. While the Ets family gene, prostate-derived epithelial factor (PDEF), is expressed in epithelial tissues, PDEF protein expression has been found to be reduced or lost during cancer progression. The goal of this study was to examine the mechanism for and biologic impact of altered PDEF expression in prostate cancer.

METHODS

PDEF protein expression of prostate specimens was examined by immunohistochemistry. RNA and protein expression in cell lines were measured by q-PCR and Western blot, respectively. Cellular growth was determined by quantifying viable and apoptotic cells over time. Cell cycle was measured by flow cytometry. Migration and invasion were determined by transwell assays. PDEF promoter occupancy was determined by chromatin immunoprecipitation (ChIP).

RESULTS

While normal prostate epithelium expresses PDEF mRNA and protein, tumors show no or decreased PDEF protein expression. Re-expression of PDEF in prostate cancer cells inhibits cell growth. PDEF expression is inversely correlated with survivin, urokinase plasminogen activator (uPA) and slug expression and ChIP studies identify survivin and uPA as direct transcriptional targets of PDEF. This study also shows that PDEF expression is regulated via a functional microRNA-204 (miR-204) binding site within the 3'UTR. Furthermore, we demonstrate the biologic significance of miR-204 expression and that miR-204 is over-expressed in human prostate cancer specimens.

CONCLUSIONS

Collectively, the reported studies demonstrate that PDEF is a negative regulator of tumor progression and that the miR-204-PDEF regulatory axis contributes to PDEF protein loss and resultant cancer progression.

hZIP1 zinc transporter down-regulation in prostate cancer involves the overexpression of ras responsive element binding protein-1 (RREB-1)

BACKGROUND

A marked decrease in the level of zinc is a consistent characteristic of prostate cancer; which results from down-regulation of ZIP1 zinc transporter. The aim of this study was to determine if RREB-1 transcription is involved in the down-regulation of ZIP1 gene expression; and to determine the expression of RREB-1 in benign and cancerous prostate in situ.

METHODS

Overexpression and siRNA knock down of RREB-1 were used to determine the effect of RREB-1 on hZIP1 abundance in PC-3 cells. Immunohistochemistry with tissue microarrays (TMAs) and tissue sections was used to determine the levels of RREB-1 expression in prostate in situ.

RESULTS

Overexpression of RREB-1 resulted in a decrease in the abundance of hZIP1 in the plasma membrane of PC-3 cells; whereas siRNA knock down significantly increased hZIP1 expression. Prostate TMAs and tissue sections showed an inverse relationship between RREB-1 and hZIP1 staining.

CONCLUSIONS

RREB-1 overexpression results in down-regulation of hZIP1 and contributes to the loss of hZIP1 expression and zinc in prostate cancer. This is an early event in prostate carcinogenesis.

Decreased zinc and downregulation of ZIP3 zinc uptake transporter in the development of pancreatic adenocarcinoma

Pancreatic adenocarcinoma is an untreatable deadly cancer. The factors involved in its early development remain unknown; which contributes to the absence of biomarkers for early detection of malignancy or at-risk subjects, and the absence of efficacious therapeutic agents. Because zinc changes are implicated in some cancers, we determined if it might be involved in the development of pancreatic adenocarcinoma. With in situ Dithizone and Zinquin staining of normal pancreas and adenocarcinoma tissue sections, we show for the first time, a consistent major loss of zinc in ductal and acinar epithelium in adenocarcinoma compared to the normal epithelium. This decrease in zinc is evident in well-differentiated through poorly-differentiated stages of malignancy. Immunohistochemistry identified ZIP3 as the basilar membrane zinc uptake transporter in normal ductal/acinar epithelium; and that the transporter is absent in adenocarcinoma. In situ Rt-PCR revealed that ZIP3 gene expression is silenced in adenocarcinoma. The ZIP3 down regulation accompanied the loss of zinc in early and progressing malignancy. RREB1 transcription factor was down regulated along with ZIP3; and might be involved in the silencing of ZIP3 expression. Zinc treatment was cytotoxic to malignant Panc1 cells. The combination of concurrent zinc, ZIP3, and RREB-1 changes represent early events in the development of adenocarcinoma; and suggest that zinc might be a tumor suppressor of pancreatic cancer. This report provides the clinical foundation for further mechanistic studies that will provide important insight into pancreatic carcinogenesis, and can lead to the development of effective early biomarkers and effective therapeutic agents for pancreatic cancer.

The genomic relationship between primary breast carcinomas and their nodal metastases

We screened the whole tumor genome to identify DNA copy number gains and losses that discriminate between primary breast carcinomas (MP) and their nodal metastases (ML). Six candidate genes were confirmed by quantitative PCR to have differentially distributed copy number changes. Three of the genes (ERRγ, DDX6, and TIAM1) were more commonly amplified in nodal metastases. Principal component analysis revealed that MP-ML pairs varied markedly in their genomic divergence. The latter was larger in PR-negative tumors. Nodal metastases may form early or late in the development of breast carcinomas and PR-negative tumors may metastasize earlier or are genomically less stable.

Identification of metastasis-associated breast cancer genes using a high-resolution whole genome profiling approach

PURPOSE

We employed a whole genome tumor profiling approach in an attempt to identify DNA copy number alterations (CNAs) and new candidate genes that are correlated with the metastatic potential of a primary breast carcinoma and with progression at the metastatic site.

METHODS

Fifty-four small (≤ 2 cm), high grade, ER-positive, formalin-fixed invasive ductal carcinomas were suitable for whole genome profiling analysis. Twenty-four of them did not form metastases within 5-10 years (unmatched primaries, UP). Thirty tumors had at least one synchronous axillary lymph node metastasis (matched primaries, MP; matched lymph node metastases, ML). Genomic DNA was hybridized to high density (19k) BAC arrays. Statistical analysis revealed differential distributions of CNAs between UP and MP and between MP and ML, respectively. We selected 27 candidate genes for validation experiments using quantitative (Q-)PCR of genomic DNA. For tetraspanin TSPAN1, we studied mRNA expression levels in a separate cohort of primary breast carcinomas and in breast cell lines.

RESULTS

Matched primary (MP) tumors had a threefold higher rate of DNA copy number losses compared to UP tumors. In the UP-MP comparison, 186 BACs were differentially amplified or deleted. Most of them were localized to chromosomes 7p, 16q and 18q. In the MP-ML comparison, 131 BACs showed differential CNAs. Most of them were localized to chromosomes 1q and 20. By Q-PCR, seven candidate genes could be confirmed to show differential distributions of CNAs. TSPAN1 was amplified in UP and deleted in MP tumors. The gene was markedly downregulated in ER-negative and high-grade breast cancers.

CONCLUSIONS

Metastasizing tumors had a higher rate of deletions, suggesting possible inactivation of metastasis suppressor genes. We provide preliminary evidence that TSPAN1 may be another important breast cancer suppressor gene belonging to the tetraspanin superfamily.

PAX-5: a valuable immunohistochemical marker in the differential diagnosis of lymphoid neoplasms

OBJECTIVE

Undifferentiated tumors and hematolymphoid neoplasms can be diagnostically challenging due to potential overlap of morphologic features and variant antigen expression. PAX-5, a transcription factor expressed throughout B-cell maturation, is detected in most B-cell neoplasms including those that lack expression of mature B-cell markers, such as classical Hodgkin lymphoma (cHL), B-lymphoblastic leukemia and B-cell lymphomas following rituximab therapy. The lack of PAX-5 expression in most CD30-positive non-hematopoietic malignancies (embryonal carcinoma and seminoma) and T-cell lymphomas, such as anaplastic large cell lymphoma (ALCL), suggests that the absence of PAX-5 may be used to confirm non-B-cell lineage. The goal of this study was to retrospectively assess PAX-5 immunoreactivity in diagnostic samples of hematolymphoid and other non-hematopoietic malignancies.

DESIGN

Diagnostic lymph node, decalcified core bone marrow biopsies and tissue sections from 111 archived paraffin-embedded tissue blocks and a tissue lymphoma microarray were immunostained using a monoclonal antibody to PAX-5. The corresponding hematoxylin and eosin stained tissue sections and additional immunostains were simultaneously evaluated. PAX-5 immunoreactivity in neoplastic cells was scored as positive or negative. This study was exempted by the Institutional Review Board for Human Research.

RESULTS

Nuclear PAX-5 immunoreactivity was detected in 88% (36/41) of Hodgkin lymphoma, all cases of diffuse large B-cell lymphoma (n=72), small B-cell lymphomas (n=5), B-lymphoblastic leukemia/lymphoma and mixed phenotype acute leukemia with B-cell lineage (n=5). PAX-5 was not detected in ALCL (n=22), T-cell lymphoblastic leukemia/lymphoma, mixed phenotype acute leukemia with T-cell lineage (n=5), acute myeloid leukemia (n=4), carcinoid tumors with typical morphology (n=5), melanoma (n=3), and undifferentiated/metastatic tumors (n=8). Non-neoplastic bone marrow sections showed scattered nuclear staining in small B-cell lymphocytes/hematogones. The detection of PAX-5 immunoreactivity resulted in the reclassification of two cases of ALCL to cHL.

CONCLUSION

Overall, our results demonstrate that including PAX-5 in a panel with other immunomarkers helps establish B-cell lineage and increases diagnostic yield.

PDEF is a negative regulator of colon cancer cell growth and migration

ETS is a family of transcriptional regulators with functions in most biological processes. Dysregulated ETS factor function leads to altered expression of multiple genes that play critical roles in many of the processes required for cancer progression. While the Ets family gene, prostate-derived ETS factor (PDEF), is expressed in epithelial tissues including prostate, breast, and colon, PDEF protein expression has been found to be reduced or lost during prostate and breast cancer progression. The goal of this study was to examine the expression and biologic impact of altered PDEF expression in colon cancer. PDEF mRNA and protein are not detectable in several colon-cancer-derived cell lines. Re-expression of PDEF in colon cancer cells inhibits growth and migration. Growth affects are due to altered cellular proliferation, indicated by increased altered cell population in G(1) and S phases of the cell cycle, as well as increased apoptosis. Relevant to its modulation of growth and migration phenotypes, PDEF expression resulted in altered expression of genes with established roles in cell cycle, motility, and invasion. Furthermore, chromatin immunoprecipitation studies show that p21 and urokinase plasminogen activator (uPA) are direct PDEF transcriptional targets. While non-tumor colon epithelium expresses PDEF mRNA and protein, the majority of tumors showed decreased mRNA and/or protein expression. In human tumor tissue samples, PDEF expression was inversely correlated with the expression levels of uPA. Collectively, the data support the model that PDEF is a negative regulator of tumor progression by modulating the expression of growth and migration promoting genes.

Sporadic cutaneous angiosarcomas generally lack hypoxia-inducible factor 1alpha: a histologic and immunohistochemical study of 45 cases

Cutaneous angiosarcoma (AS) is a rare malignant neoplasm of dermis composed of infiltrating cells of endothelial phenotype with overall poor prognosis. Although autocrine stimulation by vascular endothelial growth factor secretion may play a role in the pathogenesis of angiosarcoma, its mechanism has not been fully established. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that mediates cellular and systemic homeostatic responses to hypoxia.. The stability of HIF can regulate key proteins in angiogenesis and the alpha-subunit has been found in epithelial tumors, only 1 case of human retroperitoneal angiosarcoma, and rare vascular proliferations and tumors in knockout mice. We wanted to observe the utility of HIF-1alpha as a marker or explanatory factor in AS. Cases coded as "angiosarcoma" of dermis were culled and re-reviewed for inclusion as AS, based on patient folder, slides, and obtained immunohistochemistry including CD31 and smooth muscle actin (SMA). Hypoxia-inducible factor-1alpha was performed on a subset of cases, with additional available material. Forty-five cases met the criteria for AS; there were 17% females and 83% males, with a mean age at presentation of 67 years (range, 27-88 years). Tumors presented most commonly in the skin of the scalp followed by the left lower leg, face, nose, lower arm, neck, thigh, eyelid, ear, and temple. Associated basal cell carcinoma was noted in 1 patient; no others had other neoplasms or unrelated surgeries. There was no history of other primary, lymphedema, radiation, breast-associated, or thorotrast-induced angiosarcoma. The tumors ranged in size from 0.4 up to 9.5 cm, with a mean size of 2.4 cm. Histopathologically, most tumors were vasoformative, with either solid architecture (n = 35) or papillary endothelial hyperplasia-like foci (n = 7). All cases demonstrated infiltrative growth pattern, cytologic atypia, and mitotic activity, including atypical forms. Surface ulceration was present in 44% and solar elastosis in the most evaluable cases. Epithelioid morphology was present in 29% (n = 13) cases. Mild to moderate lymphocytic inflammatory response was noted in 62% (n = 28) cases. CD31 highlighted malignant endothelial cells. SMA (for pericytes) was generally absent. Hypoxia-inducible factor 1alpha was focally positive in cytoplasm of 3 of 18 (17%) cases studied. Treatment and follow-up data were only available on 4 cases: 2 died of disease within 4 years, 2 others had known recurrence within 2 years. Cutaneous angiosarcoma is largely found on the scalp of older individuals. Requirement for diagnosis includes extravascular proliferation of atypical endothelial cells with mitotic activity in vasoformative, solid, and papillary patterns. Absence of SMA can prove extravascular extension of tumor, outside their normal vessel confines. Cutaneous angiosarcoma generally lacks HIF-1alpha expression. Accordingly, the hypoxic response pathway is not thought to be a documentable common mechanism of angiogenesis in this entity.

Comparison between HER-2/neu, estrogen and progesterone receptors in primary breast carcinomas and matched lymph node metastases

Abstract #3053

Background: HER2, estrogen (ER) and progesterone receptors (PR) are important markers for prognostic and therapeutic implications in breast cancer. Fluorescence in situ hybridization (FISH) and IHC for HER2 gene amplification and evaluation of ER and PR in primary tumor are commonly used methods. However, evaluation of these markers in lymph nodes or distant metastases, which may be more biologically significant, is not that applicable in regular clinical basis. In the current work we compared HER2 (by FISH), ER and PR (by IHC) in matched primary breast carcinomas and lymph node metastases.&#x2028; Design: Formalin fixed, paraffin embedded tissue sections from 39 cases of primary and lymph node metastases were assessed for Her2 (by FISH). Primary tumors of the cases selected were known to be HER2 un-amplified. Also, ER and PR IHC were performed on 36 cases from the same cohort of cases to assess any discrepancy between primary and lymph node metastases of these cases.&#x2028; Result: Out of 39 cases, one case was HER2 amplified in lymph node metastasis compared to un-amplified primary tumor. Eight percent of cases (3/36) were ER negative in LN mets and 6% (2/36) were less strongly positive compared to the positive primary tumors. Nineteen percent (7/36) were PR negative in LN mets in contrast to the matched positive primary tumors. Regarding PR immunoreactivity, 6% (2/36) were PR-positive in LN met compared to their corresponding negative primary tumors.&#x2028; Conclusion: While most matched primary breast tumors and lymph node metastases show concordance in HER2, ER, PR status, we found discordance in a minority of cases. These results suggest the possibility that extension of studies in metastatic breast tumors in parallel with that of primary lesions is informative and can be used to determine further treatment options and predict prognosis in breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3053.

hZip2 and hZip3 zinc transporters are down regulated in human prostate adenocarcinomatous glands

BACKGROUND

The normal human prostate glandular epithelium has the unique function of accumulating high levels of zinc. In prostate cancer this capability is lost as an early event in the development of the malignant cells. The mechanism and factors responsible for the ability of the normal epithelial cells to accumulate zinc and the loss of this capability in the malignant cells need to be identified. We previously reported that Zip1 is an important zinc uptake transporter in prostate cells and is down regulated in the malignant cells in situ along with the depletion of zinc levels. In this report we investigated the expression of two other Zip family zinc transporters, Zip2 and Zip3 in malignant versus nonmalignant (normal and BPH) glands. Zip2 and Zip3 relative protein levels were determined by immunohistochemistry analysis of human prostate tissue sections.

RESULTS

Normal and BPH glandular epithelium consistently exhibited the strong presence of both Zip 2 and Zip3; whereas both transporters consistently were essentially non-detectable in the malignant glands. This represents the first report of the expression of Zip3 in human prostate tissue; and more importantly, reveals that ZiP2 and Zip3 are down regulated in malignant cells in situ as we also had demonstrated for Zip1. Zip2 and Zip3 transporter proteins were localized predominantly at the apical cell membrane, which is in contrast to the Zip1 localization at the basolateral membrane. Zip2 and Zip3 seemingly are associated with the re-uptake of zinc from prostatic fluid.

CONCLUSION

These results coupled with previous reports implicate Zip2 and Zip3 along with Zip1 as important zinc uptake transporters involved in the unique ability of prostate cells to accumulate high cellular zinc levels. Zip1 is important for the extraction of zinc from circulation as the primary source of cellular zinc. Zip 2 and Zip3 appear to be important for retention of the zinc in the cellular compartment. The down regulation of all three transporters in the malignant cells is consistent with the loss of zinc accumulation in these cells. Since zinc imposes tumor suppressor effects, the silencing of the gene expression for these transporters is a required event for the manifestation of the malignant activities of the neoplastic cells. This now provides new insights into the genetic/molecular events associated with the development of prostate cancer; and supports our concept of Zip1, and now Zip2 and Zip3, as tumor suppressor genes and zinc as a tumor suppressor agent.

Expression characteristics of prostate-derived Ets factor support a role in breast and prostate cancer progression

The purpose of this study was to understand the characteristics of prostate-derived Ets factor (PDEF) protein expression in breast and prostate cancer progression. A polyclonal antibody specific to PDEF was raised and reacted with tissue microarrays consisting of benign breast, in situ ductal, invasive ductal, and invasive lobular breast carcinomas. The antibody was also reacted with tissue microarrays, including benign prostate, prostate intraepithelial neoplasias (PINs), and prostate carcinomas. Increased expression of PDEF was identified in 18%, 50%, 46%, and 51% of benign breast tissues, intraductal, invasive ductal, and invasive lobular carcinomas, respectively. Importantly, in matched samples of benign breast vs tumor, 90% showed higher expression of PDEF in the tumor tissue. Moreover, in invasive breast carcinomas, increased PDEF expression tended to correlate with Her2/neu overexpression. Increased expression of PDEF was also found in 27%, 33%, and 40% of benign prostate tissues, PIN samples, and prostate adenocarcinomas, respectively. Again, in matching samples of cancer vs benign and cancer vs PIN, 68% and 70%, respectively, showed increased expression in the malignant tissue. Moreover, PDEF was found to be more highly expressed in tumors with intermediate or high Gleason score compared with low-grade tumors (P < .01). In addition, R1881 treatment induced PDEF expression in the LNCaP prostate tumor cell line, suggesting regulation of PDEF by androgens in vivo. Together, these results for the first time show frequent increased expression of PDEF protein in breast and prostate tumors and support a role for PDEF in breast and prostate cancer progression.

Mitochondrial aconitase and citrate metabolism in malignant and nonmalignant human prostate tissues

Background

In prostate cancer, normal citrate-producing glandular secretory epithelial cells undergo a metabolic transformation to malignant citrate-oxidizing cells. m-Aconitase is the critical step involved in this altered citrate metabolism that is essential to prostate malignancy. The limiting m-aconitase activity in prostate epithelial cells could be the result of a decreased level of m-aconitase enzyme and/or the inhibition of existing m-aconitase. Earlier studies identified zinc as an inhibitor of m-aconitase activity in prostate cells; and that the depletion of zinc in malignant cells is an important factor in this metabolic transformation. However, a possibility remains that an altered expression and level of m-aconitase enzyme might also be involved in this metabolic transformation. To address this issue, the in situ level of m-aconitase enzyme was determined by immunohistochemical analysis of prostate cancer tissue sections and malignant prostate cell lines.

Results

The immunocytochemical procedure successfully identified the presence of m-aconitase localized in the mitochondrial compartment in PC-3, LNCaP, and DU-145 malignant prostate cell lines. The examination of prostate tissue sections from prostate cancer subjects demonstrated that m-aconitase enzyme is present in the glandular epithelium of normal glands, hyperplastic glands, adenocrcinomatous glands, and prostatic intraepithelial neoplastic foci. Quantitative analysis of the relative level of m-aconitase in the glandular epithelium of citrate-producing adenomatous glands versus the citrate-oxidizing adenocarcinomatous glands revealed no significant difference in m-aconitase enzyme levels. This is in contrast to the down-regulation of ZIP1 zinc transporter in the malignant glands versus hyperplastic glands that exists in the same tissue samples.

Conclusion

The results demonstrate the existence of m-aconitase enzyme in the citrate-producing glandular epithelial cells; so that deficient m-aconitase enzyme is not associated with the limiting m-aconitase activity that prevents citrate oxidation in these cells. The level of m-aconitase is maintained in the malignant cells; so that an altered enzyme level is not associated with the increased m-aconitase activity. Consequently, the elevated zinc level that inhibits m-aconitase enzyme is responsible for the impaired citrate oxidation in normal and hyperplastic prostate glandular epithelial cells. Moreover, the down-regulation of ZIP1 zinc transporter and corresponding depletion of zinc results in the increase in the activity of the existing m-aconitase activity in the malignant prostate cells. The studies now define the mechanism for the metabolic transformation that characterizes the essential transition of normal citrate-producing epithelial cells to malignant citrate-oxidizing cells.

Inter-genomic cross talk between mitochondria and the nucleus plays an important role in tumorigenesis

Mitochondrial dysfunction is a hallmark of cancer cells. Consistent with this phenotype mutations in mitochondrial genome have been reported in all cancers examined to date. However, it is not clear whether mitochondrial genomic status in human cells affects nuclear genome stability and whether proteins involved in inter-genomic cross talk are involved in tumorigenesis. Using cell culture model and cybrid cell technology, we provide evidence that mitochondrial genetic status impacts nuclear genome stability in human cells. In particular our studies demonstrate 1) that depletion of mitochondrial genome (rho0) leads to chromosomal instability (CIN) reported to be present in variety of human tumors and 2) rho0 cells show transformed phenotype. Our study also demonstrates that mitochondrial genetic status plays a key role in regulation of a multifunctional protein APE1 (also known as Ref1 or HAP1) involved in transcription and DNA repair in the nucleus and the mitochondria. Interestingly we found that altered expression of APE1 in rho0 cells and tumorigenic phenotype can be reversed by exogenous transfer of wild type mitochondria in rho0 cells. Furthermore, we demonstrate that APE1 expression is altered in variety of primary tumors. Taken together, these studies suggest that inter-genomic cross talk between mitochondria and the nucleus plays an important role in tumorigenesis and that APE1 mediates this process.

hZIP1 zinc uptake transporter down regulation and zinc depletion in prostate cancer

Background

The genetic and molecular mechanisms responsible for and associated with the development and progression of prostate malignancy are largely unidentified. The peripheral zone is the major region of the human prostate gland where malignancy develops. The normal peripheral zone glandular epithelium has the unique function of accumulating high levels of zinc. In contrast, the ability to accumulate zinc is lost in the malignant cells. The lost ability of the neoplastic epithelial cells to accumulate zinc is a consistent factor in their development of malignancy. Recent studies identified ZIP1 (SLC39A1) as an important zinc transporter involved in zinc accumulation in prostate cells. Therefore, we investigated the possibility that down-regulation of hZIP1 gene expression might be involved in the inability of malignant prostate cells to accumulate zinc. To address this issue, the expression of hZIP1 and the depletion of zinc in malignant versus non-malignant prostate glands of prostate cancer tissue sections were analyzed. hZIP1 expression was also determined in malignant prostate cell lines.

Results

hZIP1 gene expression, ZIP1 transporter protein, and cellular zinc were prominent in normal peripheral zone glandular epithelium and in benign hyperplastic glands (also zinc accumulating glands). In contrast, hZIP1 gene expression and transporter protein were markedly down-regulated and zinc was depleted in adenocarcinomatous glands and in prostate intra-epithelial neoplastic foci (PIN). These changes occur early in malignancy and are sustained during its progression in the peripheral zone. hZIP1 is also expressed in the malignant cell lines LNCaP, PC-3, DU-145; and in the nonmalignant cell lines HPr-1 and BPH-1.

Conclusion

The studies clearly establish that hZIP1 gene expression is down regulated and zinc is depleted in adenocarcinomatous glands. The fact that all the malignant cell lines express hZIP1 indicates that the down-regulation in adenocarcinomatous glands is likely due to in situ gene silencing. These observations, coupled with the numerous and consistent reports of loss of zinc accumulation in malignant cells in prostate cancer, lead to the plausible proposal that down regulation of hZIP1 is a critical early event in the development prostate cancer.