Kathleen C. Torkko

B7-H4 Is Highly Expressed in Ductal and Lobular Breast Cancer

Purpose: This study was designed to investigate the expression of B7-H4 protein, a member of the B7 family that is involved in the regulation of antigen-specific immune responses, in normal breast and in primary and metastatic breast carcinomas. Experimental Design: Archival formalin-fixed tissue blocks from breast cancers and normal somatic tissues were evaluated for B7-H4 expression by immunohistochemistry with manual and automated image analysis. The proportion of B7-H4-positive cells and the intensity of B7-H4 staining were compared with histologic type, grade, stage, hormone receptor status, and HER-2/neu status. Results: B7-H4 was detected in 165 of 173 (95.4%) primary breast cancers and in 240 of 246 (97.6%) metastatic breast cancers. B7-H4 staining intensity was greater in invasive ductal carcinomas [24.61 relative units (RU)] and in invasive lobular carcinomas (15.23 RU) than in normal breast epithelium (4.30 RU, P = 0.0003). Increased staining intensity was associated with negative progesterone receptor status (P = 0.014) and history of neoadjuvant chemotherapy (P = 0.004), and the proportion of B7-H4-positive cells was associated with negative progesterone receptor (P = 0.001) and negative HER-2/neu (P = 0.024) status. However, there was no statistically significant relationship between the proportion of B7-H4-positive cells or staining intensity and grade, stage, or other clinicopathologic variables. Low levels of B7-H4 expression were also detected in epithelial cells of the female genital tract, lung, pancreas, and kidney, but B7-H4 was generally absent in most other normal somatic tissues. Conclusions: The nearly ubiquitous expression of B7-H4 in breast cancer, independent of tumor grade or stage, suggests a critical role for this protein in breast cancer biology.

Role of the androgen receptor in breast cancer and preclinical analysis of enzalutamide

IntroductionThe androgen receptor (AR) is widely expressed in breast cancers and has been proposed as a therapeutic target in estrogen receptor alpha (ER) negative breast cancers that retain AR. However, controversy exists regarding the role of AR, particularly in ER + tumors. Enzalutamide, an AR inhibitor that impairs nuclear localization of AR, was used to elucidate the role of AR in preclinical models of ER positive and negative breast cancer.MethodsWe examined nuclear AR to ER protein ratios in primary breast cancers in relation to response to endocrine therapy. The effects of AR inhibition with enzalutamide were examined in vitro and in preclinical models of ER positive and negative breast cancer that express AR.ResultsIn a cohort of 192 women with ER + breast cancers, a high ratio of AR:ER (≥2.0) indicated an over four fold increased risk for failure while on tamoxifen (HR = 4.43). The AR:ER ratio had an independent effect on risk for failure above ER % staining alone. AR:ER ratio is also an independent predictor of disease-free survival (HR = 4.04, 95% CI: 1.68, 9.69; p = 0.002) and disease specific survival (HR = 2.75, 95% CI: 1.11, 6.86; p = 0.03). Both enzalutamide and bicalutamide inhibited 5-alpha-dihydrotestosterone (DHT)-mediated proliferation of breast cancer lines in vitro; however, enzalutamide uniquely inhibited estradiol (E2)-mediated proliferation of ER+/AR + breast cancer cells. In MCF7 xenografts (ER+/AR+) enzalutamide inhibited E2-driven tumor growth as effectively as tamoxifen by decreasing proliferation. Enzalutamide also inhibited DHT- driven tumor growth in both ER positive (MCF7) and negative (MDA-MB-453) xenografts, but did so by increasing apoptosis.ConclusionsAR to ER ratio may influence breast cancer response to traditional endocrine therapy. Enzalutamide elicits different effects on E2-mediated breast cancer cell proliferation than bicalutamide. This preclinical study supports the initiation of clinical studies evaluating enzalutamide for treatment of AR+ tumors regardless of ER status, since it blocks both androgen- and estrogen- mediated tumor growth.

Clinical staging of prostate cancer : a computer-simulated study of transperineal prostate biopsy

To identify the precise location of prostate cancer within the gland and thus possibly permit more aggressive therapy of the lesion, while potentially sparing the noncancerous gland from ablative therapy.

Human papillomavirus testing and molecular markers of cervical dysplasia and carcinoma.

Cervical cancer is the second most common cancer in women worldwide. Human papillomavirus (HPV) is the etiologic agent for the vast majority of premalignant and malignant lesions, and high‐risk HPV types can be detected in almost all cases of cervical dysplasia and carcinoma. HPV testing has been widely adopted for the triage of patients after a cervical cytology screening test (Papanicolaou smear or liquid‐based cervical cytology such as ThinPrep or SurePath) interpretation of atypical squamous cells of undetermined significance (ASCUS), and HPV testing is increasingly used for screening in conjunction with cervical cytology. Although cervical cytology is a highly effective screening test for cancer, it has limited specificity for clinically significant lesions in cases with low‐grade cytologic abnormalities. Up to a quarter of all patients may have a false‐negative result on the basis of cervical cytology testing alone. This review focuses on HPV testing methods and molecular markers and their clinical relevance. HPV testing and surrogate molecular markers of HPV infection (p16INK4a) may help identify cases that are associated with underlying high‐grade premalignant or malignant lesions and may also reduce aggressive treatment of patients with low‐grade lesions. Cancer (Cancer Cytopathol) 2007;.

Tolerance of the Human Kidney to Isolated Controlled Ischemia

Tolerance of the human kidney to ischemia is controversial. Here, we prospectively studied the renal response to clamp ischemia and reperfusion in humans, including changes in putative biomarkers of AKI. We performed renal biopsies before, during, and after surgically induced renal clamp ischemia in 40 patients undergoing partial nephrectomy. Ischemia duration was >30 minutes in 82.5% of patients. There was a mild, transient increase in serum creatinine, but serum cystatin C remained stable. Renal functional changes did not correlate with ischemia duration. Renal structural changes were much less severe than observed in animal models that used similar durations of ischemia. Other biomarkers were only mildly elevated and did not correlate with renal function or ischemia duration. In summary, these data suggest that human kidneys can safely tolerate 30-60 minutes of controlled clamp ischemia with only mild structural changes and no acute functional loss.

ZEB1 expression in type I vs type II endometrial cancers: a marker of aggressive disease

Zinc-finger E-box-binding homeobox 1 (ZEB1) is a transcription factor containing two clusters of Kruppel-type zinc-fingers, by which it binds E-box-like sequences on target DNAs. A role for ZEB1 in tumor progression, specifically, epithelial to mesenchymal transitions, has recently been revealed. ZEB1 acts as a master repressor of E-cadherin and other epithelial markers. We previously demonstrated that ZEB1 is confined to the stromal compartment in normal endometrium and low-grade endometrial cancers. Here, we quantify ZEB1 protein expression in endometrial samples from 88 patients and confirm that it is expressed at significantly higher levels in the tumor-associated stroma of low-grade endometrioid adenocarcinomas (type I endometrial cancers) compared to hyperplastic or normal endometrium. In addition, as we previously reported, ZEB1 is aberrantly expressed in the epithelial-derived tumor cells of highly aggressive endometrial cancers, such as FIGO grade 3 endometrioid adenocarcinomas, uterine serous carcinomas, and malignant mixed Müllerian tumors (classified as type II endometrial cancers). We now demonstrate, in both human endometrial cancer specimens and cell lines, that when ZEB1 is inappropriately expressed in epithelial-derived tumor cells, E-cadherin expression is repressed, and that this inverse relationship correlates with increased migratory and invasive potential. Forced expression of ZEB1 in the nonmigratory, low-grade, relatively differentiated Ishikawa cell line renders them migratory. Conversely, reduction of ZEB1 in a highly migratory and aggressive type II cell line, Hec50co, results in reduced migratory capacity. Thus, ZEB1 may be a biomarker of aggressive endometrial cancers at high risk of recurrence. It may help identify women who would most benefit from chemotherapy. Furthermore, if expression of ZEB1 in type II endometrial cancers could be reversed, it might be exploited as therapy for these highly aggressive tumors.

Digital Quantification of Five High-Grade Prostate Cancer Patterns, Including the Cribriform Pattern, and Their Association With Adverse Outcome

Proper grading of the cribriform prostate cancer pattern has not previously been supported by outcome-based evidence. Among 153 men who underwent radical prostatectomy, 76 with prostate-specific antigen (PSA) failure (≥0.2 ng/mL [0.2 μg/L]) were matched to 77 without failure. Frequencies of high-grade patterns included fused small acini, 83.7%; papillary, 52.3%; large cribriform, 37.9%; small (≤12 lumens) cribriform, 17.0%; and individual cells, 22.9%. A cribriform pattern was present in 61% (46/76) of failures but 16% (12/77) of nonfailures (P < .0001). Multivariate analysis showed the cribriform pattern had the highest odds ratio for PSA failure, 5.89 (95% confidence interval, 2.53-13.70; P < .0001). The presence of both large and small cribriform patterns was significantly linked to failure. The cumulative odds ratio of failure per added square millimeter of cribriform pattern was 1.173 (P = .008), higher than for any other pattern. All 8 men with a cribriform area sum of 25 mm(2) or more had failure (range, 33-930). Regrading cribriform cancer as Gleason 5 improved the grade association with failure, although half of all cases with individual cells also had a cribriform pattern, precluding a precise determination of the independent importance of the latter. The cribriform pattern has particularly adverse implications for outcome.

Detection of B7-H4 and p53 in pancreatic cancer: potential role as a cytological diagnostic adjunct.

Objectives: This study compared p53 expression with B7-H4, a novel cancer biomarker, in pancreatic ductal adenocarcinoma (PDA) resection specimens and in a pilot series of endoscopic ultrasound-guided fine-needle aspirations (EUS-FNAs). Methods: B7-H4 and p53 expression were evaluated by immunoperoxidase methods in 36 PDA and 15 EUS-FNA specimens and were scored for intensity and proportion of positive cells; cases were then assigned a final sum score. Results: B7-H4 was detected in 33 (92%) of 36 PDA sections, 8 (89%) of 9 cytologically positive EUS-FNAs, and 1 (20%) of 5 cytologically negative EUS-FNAs. p53 was detected in 30 (83%) of 36 PDA sections, 4 (44%) of 9 cytologically positive EUS-FNAs, and 1 (20%) of 5 cytologically negative cases. One EUS-FNA case that was cytologically atypical but not diagnostic of malignancy expressed B7-H4 and p53. Some benign tissue components (intercalated cells/ducts, main pancreatic ducts, and acinar cells) were also positive for B7-H4 and/or p53. Overall expression of B7-H4 in benign tissues, however, was relatively low compared with that seen in most carcinoma cases. Conclusions: B7-H4 was expressed more often in PDA than was p53. Despite potentially problematic expression in benign/normal cells, the 2 markers target different cellular components and demonstrate potential diagnostic use for detection of PDA in resected and EUS-FNA specimens.

Steroid receptor coactivator AIB1 in endometrial carcinoma, hyperplasia and normal endometrium: Correlation with clinicopathologic parameters and biomarkers.

Members of the p160 steroid receptor cofactor family, including AIB1 (Amplified in Breast Cancer 1) (also known as SRC-3/RAC3/ACTR/pCIP/TRAM-1), are of interest in endometrial carcinoma as they affect the function of estrogen (ER) and progesterone receptors (PR). Since it is feasible that alterations in the expression levels of coregulators can either augment ER activity or reduce the ability of PR to oppose ER action in endometrial cancers, our primary aim was to analyze expression of the AIB1 protein in endometrial carcinoma, carcinoma-associated complex atypical hyperplasia, and carcinoma-associated normal endometrium using immunohistochemistry and tissue microarrays. Expression of AIB1 was compared with other biomarkers and clinicopathologic parameters. We also tested AIB1 expression in non-carcinoma associated hyperplastic, normal secretory and proliferative endometrium to determine baseline AIB1 levels. In endometrial carcinoma, there is a higher expression of AIB1 compared to carcinoma-associated complex atypical hyperplasia (0.007) or carcinoma-associated normal endometrium (<0.001). AIB1 expression correlates with older age (P=0.003), peri- or postmenopausal status (P=0.002) and a higher grade of carcinomas (P=0.04). There were no differences in the expression of additional steroid hormone receptor co-activators (SRC-1 and p300/CBP) and the co-repressor SMRT between histologic categories. AIB1 expression correlated with ER (r=0.30, P=0.006). The strongest correlation was between ER and PR-B isoform nuclear expression (r=0.52, P<0.0001). AIB1 levels were higher in non-carcinoma associated normal and hyperplastic endometrium compared to carcinoma-associated complex atypical hyperplasia and carcinoma-associated normal endometrium, and were the highest in normal secretory endometrium. In conclusion, high AIB1 expression in endometrial carcinoma is associated with parameters of poor prognosis. We propose that when AIB1 is overexpressed in endometrial carcinoma, ER action is augmented, leading to endometrial hyperplasia and progression to malignancy. Future studies correlating expression with response to hormonal therapy may be beneficial.

The HER4/4ICD estrogen receptor coactivator and BH3-only protein is an effector of tamoxifen-induced apoptosis.

Greater than 40% of breast cancer patients treated with tamoxifen exhibit de novo or acquired tumor resistance. Recent clinical evidence indicates that loss of expression of HER4 is an independent marker for tamoxifen resistance. In direct corroboration with clinical observations, suppression of HER4 expression in the tamoxifen-sensitive MCF-7 and T47D breast tumor cell lines resulted in resistance to tamoxifen-induced apoptosis. Furthermore, HER4 expression was lost in three independent MCF-7 models of acquired tamoxifen resistance. The HER4 intracellular domain (4ICD) is an independently signaling nuclear protein that functions as a potent ERalpha coactivator. In addition, mitochondrial 4ICD functions as a proapoptotic BH3-only protein. Tamoxifen disrupts an estrogen-driven interaction between ERalpha and 4ICD while promoting mitochondrial accumulation of the 4ICD BH3-only protein. BCL-2 inhibition of tamoxifen-induced apoptosis and tamoxifen activation of BAK, independent of BAX, further supports a role for 4ICD during tamoxifen-induced apoptosis. Finally, reintroduction of HER4, but not HER4 with a mutated BH3 domain, restores tamoxifen sensitivity to tamoxifen-resistant TamR cells in a xenograft model. Clinically, breast cancer patients with tumor expression of nuclear 4ICD responded to tamoxifen therapy with no clinical failures reported after 14 years of follow-up, whereas 20% of patients lacking nuclear 4ICD expression succumbed to their disease within 10 years of diagnosis. Our identification of the HER4/4ICD BH3-only protein as a critical mediator of tamoxifen action provides a clinically important role for 4ICD in human cancer and reveals a potential tumor marker to predict patient response to tamoxifen therapy.