Kathleen Whitney

Progression to Malignancy in the Polyoma Middle T Oncoprotein Mouse Breast Cancer Model Provides a Reliable Model for Human Diseases

Animal models are powerful tools to analyze the mechanism of the induction of human breast cancer. Here we report a detailed analysis of mammary tumor progression in one mouse model of breast cancer caused by expression of the polyoma middle T oncoprotein (PyMT) in the mammary epithelium, and its comparison to human breast tumors. In PyMT mice, four distinctly identifiable stages of tumor progression from premalignant to malignant stages occur in a single primary tumor focus and this malignant transition is followed by a high frequency of distant metastasis. These stages are comparable to human breast diseases classified as benign or in situ proliferative lesions to invasive carcinomas. In addition to the morphological similarities with human breast cancer, the expression of biomarkers in PyMT-induced tumors is also consistent with those associated with poor outcome in humans. These include a loss of estrogen and progesterone receptors as well as integrin-beta1 expression and the persistent expression of ErbB2/Neu and cyclinD1 in PyMT-induced tumors as they progress to the malignant stage. An increased leukocytic infiltration was also closely associated with the malignant transition. This study demonstrates that the PyMT mouse model is an excellent one to understand the biology of tumor progression in humans.

Selective gene-expression profiling of migratory tumor cells in vivo predicts clinical outcome in breast cancer patients

IntroductionMetastasis of breast cancer is the main cause of death in patients. Previous genome-wide studies have identified gene-expression patterns correlated with cancer patient outcome. However, these were derived mostly from whole tissue without respect to cell heterogeneity. In reality, only a small subpopulation of invasive cells inside the primary tumor is responsible for escaping and initiating dissemination and metastasis. When whole tissue is used for molecular profiling, the expression pattern of these cells is masked by the majority of the noninvasive tumor cells. Therefore, little information is available about the crucial early steps of the metastatic cascade: migration, invasion, and entry of tumor cells into the systemic circulation.MethodsIn the past, we developed an in vivo invasion assay that can capture specifically the highly motile tumor cells in the act of migrating inside living tumors. Here, we used this assay in orthotopic xenografts of human MDA-MB-231 breast cancer cells to isolate selectively the migratory cell subpopulation of the primary tumor for gene-expression profiling. In this way, we derived a gene signature specific to breast cancer migration and invasion, which we call the Human Invasion Signature (HIS).ResultsUnsupervised analysis of the HIS shows that the most significant upregulated gene networks in the migratory breast tumor cells include genes regulating embryonic and tissue development, cellular movement, and DNA replication and repair. We confirmed that genes involved in these functions are upregulated in the migratory tumor cells with independent biological repeats. We also demonstrate that specific genes are functionally required for in vivo invasion and hematogenous dissemination in MDA-MB-231, as well as in patient-derived breast tumors. Finally, we used statistical analysis to show that the signature can significantly predict risk of breast cancer metastasis in large patient cohorts, independent of well-established prognostic parameters.ConclusionsOur data provide novel insights into, and reveal previously unknown mediators of, the metastatic steps of invasion and dissemination in human breast tumors in vivo. Because migration and invasion are the early steps of metastatic progression, the novel markers that we identified here might become valuable prognostic tools or therapeutic targets in breast cancer.

Repeated testicular infarction in a patient with sickle cell disease: a possible mechanism for testicular failure

We report a case of repeated testicular infarction in a 39-year-old man with sickle cell disease. The patient presented with a 2-week history of testicular pain and was found clinically and sonographically to have a testicular mass, suspicious for a testicular tumor. The pathologic examination of the orchiectomy specimen revealed multiple infarcts, showing temporal variation ranging from acute (several days old) to recent (2 to 3 weeks old) to remote. This is the fifth case of segmental testicular infarction reported in patients with sickle cell disease/trait. We propose repeated testicular infarction as a probable mechanism of testicular failure and impaired fertility in patients with sickle cell disease.

Novel epigenetic changes in CDKN2A are associated with progression of cervical intraepithelial neoplasia

OBJECTIVE To conduct a comprehensive mapping of the genomic DNA methylation in CDKN2A, which codes for the p16(INK4A) and p14(ARF) proteins, and 14 of the most promising DNA methylation marker candidates previously reported to be associated with progression of low-grade cervical intraepithelial neoplasia (CIN1) to cervical cancer. METHODS We analyzed DNA methylation in 68 HIV-seropositive and negative women with incident CIN1, CIN2, CIN3 and invasive cervical cancer, assaying 120 CpG dinucleotide sites spanning APC, CDH1, CDH13, CDKN2A, CDKN2B, DAPK1, FHIT, GSTP1, HIC1, MGMT, MLH1, RARB, RASSF1, TERT and TIMP3 using the Illumina Infinium array. Validation was performed using high resolution mapping of the target genes with HELP-tagging for 286 CpGs, followed by fine mapping of candidate genes with targeted bisulfite sequencing. We assessed for statistical differences in DNA methylation levels for each CpG loci assayed using univariate and multivariate methods correcting for multiple comparisons. RESULTS In our discovery sample set, we identified dose dependent differences in DNA methylation with grade of disease in CDKN2A, APC, MGMT, MLH1 and HIC1, whereas single CpG locus differences between CIN2/3 and cancer groups were seen for CDH13, DAPK1 and TERT. Only those CpGs in the gene body of CDKN2A showed a monotonic increase in methylation between persistent CIN1, CIN2, CIN3 and cancers. CONCLUSION Our data suggests a novel link between early cervical disease progression and DNA methylation in a region downstream of the CDKN2A transcription start site that may lead to increased p16(INK4A)/p14(ARF) expression prior to development of malignant disease.

Insulin/IGF and sex hormone axes in human endometrium and associations with endometrial cancer risk factors

PurposeExperimental and observational data link insulin, insulin-like growth factor (IGF), and estrogens to endometrial tumorigenesis. However, there are limited data regarding insulin/IGF and sex hormone axes protein and gene expression in normal endometrial tissues, and very few studies have examined the impact of endometrial cancer risk factors on endometrial tissue biology.MethodsWe evaluated endometrial tissues from 77 premenopausal and 30 postmenopausal women who underwent hysterectomy for benign indications and had provided epidemiological data. Endometrial tissue mRNA and protein levels were measured using quantitative real-time PCR and immunohistochemistry, respectively.ResultsIn postmenopausal women, we observed higher levels of phosphorylated IGF-I/insulin receptor (pIGF1R/pIR) in diabetic versus non-diabetic women (p value =0.02), while women who reported regular nonsteroidal anti-inflammatory drug use versus no use had higher levels of insulin and progesterone receptors (both p values ≤0.03). We also noted differences in pIGF1R/pIR staining with OC use (postmenopausal women only), and the proportion of estrogen receptor-positive tissues varied by the number of live births and PTEN status (premenopausal only) (p values ≤0.04). Compared to premenopausal proliferative phase women, postmenopausal women exhibited lower mRNA levels of IGF1, but higher IGFBP1 and IGFBP3 expression (all p values ≤0.004), and higher protein levels of the receptors for estrogen, insulin, and IGF-I (all p values ≤0.02). Conversely, pIGF1R/pIR levels were higher in premenopausal proliferative phase versus postmenopausal endometrium (p value =0.01).ConclusionsThese results highlight links between endometrial cancer risk factors and mechanistic factors that may contribute to early events in the multistage process of endometrial carcinogenesis.

Primary bilateral ovarian and uterine Burkitt’s lymphoma following chemotherapy for breast cancer

BackgroundBurkitt’s lymphoma is extremely rare in the United States, with reports of approximately 300 new cases each year. A case of Burkitt’s lymphoma involving the uterus, cervix, ovaries and appendix 15 years after adjuvant chemotherapy for breast cancer is presented.Case reportA 58-year-old woman presented with an abdominal mass. MRI revealed a pelvic mass originating from the uterus. Her past medical history was significant for an infiltrating ductal carcinoma of the left breast with positive lymph nodes and extra nodal invasion diagnosed at age 43. She had a left modified radical mastectomy in 1990 with adjuvant chemotherapy. Histologic sections of the uterus, cervix, ovaries, appendix and external iliac lymph node obtained at laparotomy revealed diffuse neoplastic lymphoid infiltration with necrosis. Light microscopy revealed starry sky patterns and immunohistochemical staining demonstrated atypical lymphocytes which stained for CD20, CD10, bcl-6, and Ki-67. After complete staging, chemotherapy was started and the patient is presently tumor free 41 months after the diagnosis.ConclusionBurkitt’s lymphoma arising from the uterus/cervix is extremely rare and may present as a pelvic mass. Early diagnosis, aggressive chemotherapy, ±surgical intervention, plays an important role in management and survival of patients with Burkitt’s lymphoma.

Quantification of nucleolar channel systems: uniform presence throughout the upper endometrial cavity

OBJECTIVE To determine the prevalence of nucleolar channel systems (NCSs) by uterine region, applying continuous quantification. DESIGN Prospective clinical study. SETTING Tertiary care academic medical center. PATIENT(S) Forty-two naturally cycling women who underwent hysterectomy for benign indications. INTERVENTION(S) NCS presence was quantified by a novel method in six uterine regions-fundus, left cornu, right cornu, anterior body, posterior body, and lower uterine segment (LUS)-with the use of indirect immunofluorescence. MAIN OUTCOME MEASURE(S) Percentage of endometrial epithelial cells (EECs) with NCSs per uterine region. RESULT(S) NCS quantification was observer independent (intraclass correlation coefficient 0.96) and its intrasample variability low (coefficient of variation 0.06). Eleven of 42 hysterectomy specimens were midluteal, ten of which were analyzable with nine containing >5% EECs with NCSs in at least one region. The percentage of EECs with NCSs varied significantly between the LUS (6.1%; interquartile range [IQR] 3.0-9.9) and the upper five regions (16.9%; IQR 12.7-23.4), with fewer NCSs in the basal layer of the endometrium (17 ± 6%) versus the middle (46 ± 9%) and luminal layers (38 ± 9%) of all six regions. CONCLUSION(S) NCS quantification during the midluteal phase demonstrates uniform presence throughout the endometrial cavity, excluding the LUS, with a preference for the functional luminal layers. Our quantitative NCS evaluation provides a benchmark for future studies and further supports NCS presence as a potential marker for the window of implantation.

A Clinical and Pathologic Comparison Between Stage-Matched Endometrial Intraepithelial Carcinoma and Uterine Serous Carcinoma Is There a Difference?

Endometrial intraepithelial carcinoma (EIC) is a rare pathologic variant of uterine serous carcinoma (USC). Our aim is to distinguish patterns of clinic–pathologic outcomes in patients with EIC and USC for disease limited to the endometrium (stage 1A) as well as with distant metastasis (stage 4B). Surgically staged patients were retrospectively identified and relevant variables were extracted and compared. Kaplan-Meier was used to generate the survival data. More USC (n = 29) exhibited lymphovascular invasion (stage 4, P = .01) and expressed higher levels of estrogen receptor-α than EIC (P = .0009 and .063 for stages 1 and 4, respectively). The survival is comparable, with 1 recurrence in each group for stage 1A disease. For stage 4 EIC and USC, the progression-free survival (14 vs10 months) and overall survival (19 vs 20 months) are similar to what is previously published. In conclusion, EIC, whether limited to the endometrium, or widely metastatic, imparts similar outcomes and should be treated comparably with stage-matched USC.

Bilateral cribriform ductal proliferation in the male breast; a mimicker of female cribriform atypical ductal hyperplasia?

it is also unlikely that the positive reactions observed in this study arose from non-specific reactions. We therefore concluded that primary breast cancers can express TTF-1 on rare occasions. A notable point of this study is that rare tumours of the breast can be positive for TTF-1 even if they show obvious ductal differentiation. Furthermore, the expression could be retained even in the metastatic foci, as seen in case 3. Because a significant number of lung adenocarcinomas are also positive for oestrogen receptor, a panel including only TTF-1 and oestrogen receptor may not be sufficient to enable a differential diagnosis between breast and lung adenocarcinomas. Other molecules, such as mammaglobin for breast cancer and surfactant proteins for lung adenocarcinoma, are indispensable, and help to prevent misdiagnosis in cases of TTF-1-positive breast tumours. This study calls attention to the fact that surgical pathologists should be aware of potential pitfalls in the differential diagnosis of breast and lung adenocarcinomas.