Sophia George

Functional immobilization of signaling proteins enables control of stem cell fate

The mode of ligand presentation has a fundamental role in organizing cell fate throughout development. We report a rapid and simple approach for immobilizing signaling ligands to maleic anhydride copolymer thin-film coatings, enabling stable signaling ligand presentation at interfaces at defined concentrations. We demonstrate the utility of this platform technology using leukemia inhibitory factor (LIF) and stem cell factor (SCF). Immobilized LIF supported mouse embryonic stem cell (mESC) pluripotency for at least 2 weeks in the absence of added diffusible LIF. Immobilized LIF activated signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase (MAPK) signaling in a dose-dependent manner. The introduced method allows for the robust investigation of cell fate responses from interface-immobilized ligands.

Developmental and adult phenotyping directly from mutant embryonic stem cells

Tetraploid embryo complementation assay has shown that mouse ES cells alone are capable of supporting embryonic development and adult life of mice. Newly established F1 hybrid ES cells allow the production of ES cell-derived animals at a high enough efficiency to directly make ES cell-based genetics feasible. Here we report the establishment and characterization of 12 new F1 hybrid ES cell lines and the use of one of the best (G4) in a gain- and loss-of-function genetic study, where the in vivo phenotypes were assessed directly from ES cell-derived embryos. We found the generation of G4 ES cell-derived animals to be very efficient. Furthermore, even after two consecutive rounds of genetic modifications, the majority of transgenic lines retained the original potential of the parental lines; with 10–40% of chimeras producing ES cell-derived animals/embryos. Using these genetically altered ES cells, this success rate, in most cases, permitted the derivation of a sufficient number of mutants for initial phenotypic analyses only a few weeks after the establishment of the cell lines. Although the experimental design has to take into account a moderate level of uncontrolled damage on ES cell lines, our proof-of-principle experiment provides useful data to assist future designs harnessing the power of this technology to accelerate our understanding of gene function.

BRCA and Early Events in the Development of Serous Ovarian Cancer

Women who have an inherited mutation in the BRCA1 or BRCA2 genes have a substantial increased lifetime risk of developing epithelial ovarian cancer (EOC), and epidemiological factors related to parity, ovulation, and hormone regulation have a dramatic effect on the risk in both BRCA mutation carriers and non-carriers. The most common and most aggressive histotype of EOC, high-grade serous carcinoma (HGSC), is also the histotype associated with germline BRCA mutations. In recent years, evidence has emerged indicating that the likely tissue of origin of HGSC is the fallopian tube. We have reviewed, what is known about the fallopian tube in BRCA mutation carriers at both the transcriptional and translational aspect of their biology. We propose that changes of the transcriptome in BRCA heterozygotes reflect an altered response to the ovulatory stresses from the microenvironment, which may include the post-ovulation inflammatory response and altered reproductive hormone physiology.

Identification of abrogated pathways in fallopian tube epithelium from BRCA1 mutation carriers

The discovery of occult invasive and intra‐epithelial tubal carcinomas in BRCA1 mutation carriers undergoing prophylactic surgery has implicated the fallopian tube epithelium as the source of serous cancer. However, little is known of the early molecular events of serous oncogenesis, or why cancers in BRCA1 mutation carriers are found preferentially in tissues which are responsive to reproductive hormones. We hypothesize that molecular alterations present in morphologically normal tubal epithelium from BRCA1 heterozygotes reflect the earliest events in serous carcinogenesis and may be markers of increased cancer risk as well as targets for risk reduction. Genetic profiling of microdissected tubal epithelium from histologically normal BRCA1 mutation carriers and controls was performed. We sought to define a signature which differentiated BRCA1 mutant tubal epithelium from women with low risk of developing ovarian cancer. Molecular differences between the follicular and luteal phases were prominent and, by using filtering techniques and a two‐way ANOVA without a False Discovery Rate correction, we identified 440 probe sets with a more than two‐fold change in gene expression related to BRCA1 mutation status. Using gene ontology and known associations to cancer pathways, we selected five genes for further analysis by qPCR and immunohistochemistry, and were able to demonstrate statistically significant differentiation of BRCA1 and control cases in an independent set of cases. The altered expression profiles in histologically normal tubal epithelium from BRCA1 heterozygotes suggest that these cells may respond differently to microenvironmental stresses. Copyright

Proliferation in the normal FTE is a hallmark of the follicular phase not BRCA mutation status

Purpose: Women who have inherited germline mutations of BRCA1/BRCA2 are at increased risk of developing high-grade serous carcinoma, and many of these cancers arise in the distal fimbriated end of the fallopian tube. We have previously shown that the fallopian tube epithelia of BRCA1 mutation carriers (FTE-BRCA) have altered signaling pathways compared to nonmutation carriers. In this study, we sought to determine whether these differences result in a proliferative advantage to the epithelia in this high-risk patient population and to investigate whether the postovulation environment of the FTE-BRCA compared to FTE from nonmutation carriers experiences a differential abundance of immune cells. Method: Immunohistochemistry for Ki67, CD3, CD8, CD20, and CD68 was performed on histologically normal tubal epithelium (ampulla, n = 83), fimbria (n = 18) with known ovarian cycle status and germline mutation status and for Ki67 on fimbrial epithelium from women (n = 144) with and without BRCA1 or BRCA2 mutations who underwent risk-reducing salpingo-oophorectomy (RRSO). Serous tubal intraepithelial carcinomas (STIC) with concomitant cancer (n = 15) were also analyzed for presence of immune infiltrates. All slides were digitized and analyzed using automated image analysis software. Results: There was no significant difference in the proliferative index in histologically normal FTE between BRCA1/BRCA2 and non-BRCA, in 144 fimbriae and 83 ampullae. The FTE-BRCA1 epithelia did not exhibit a differential presence of lymphocytes or macrophages, however more macrophages were present in the luteal phase compared to the follicular phase epithelia. In STICs macrophages were more abundant than lymphocytes with an incremental increase noted with disease progression. Conclusions: BRCA1/2 mutation carriers exhibited no significant increase in proliferation in the fallopian tube epithelial cells either in the ampulla or fimbriated ends of the tube. Rather, a significant proliferative increase was defined in the cases determined to be in the follicular, or proliferative, preovulatory phase of the ovarian cycle. Finally, we also show an incremental increase in leukocytes invading the STICs and HGSC, implicating a possible role of the leukocytes early in the progression or inhibition of tumor formation, which is independent of ovarian cycle status. Clin Cancer Res; 18(22); 6199–207. ©2012 AACR.

Retinoblastoma pathway deregulatory mechanisms determine clinical outcome in high-grade serous ovarian carcinoma

Alterations in the retinoblastoma pathway are frequent in ovarian/tubal high-grade serous cancers, but the mechanism of deregulation and the impact on patient outcome are poorly understood. A cohort of 334 high-grade serous carcinomas was studied by immunohistochemical analysis of RB1, p16, cyclin D1, cyclin E1, and Ki67. Additional detailed analyses including RB1 allelic deletion (n=42), mutation (n=75), methylation (n=31), and SNP array analyses (n=75) were performed on cases with clinical parameters, including age, debulking status, treatment, and clinical outcome. p16/RB1 expression results yielded three distinct clinically relevant subgroups upon multivariable analysis controlling for stage, debulking status, and treatment types: p16 homogeneous/RB1+ with the shortest progression-free survival (median 15 months (95% CI: 13–18); P=0.016) compared with the p16 heterogeneous/RB1+ subgroup (median 22 months (95% CI: 16–32)) and the p16 homogeneous/RB1− subgroup (median 20 months (95% CI: 15–24)). Patients in the p16 homo/RB1− subgroup showed a significant increase in overall survival (>60 months; P=0.013), which suggests an increase in sensitivity to cytotoxic agents. Analyses of Rb pathway mechanistic differences among these groups revealed frequent RB1 genomic alterations such as RB1 allelic loss and/or large spanning deletions (83%) in the p16 homo/RB1− subgroups, also indicating that RB1 deletions are frequent in high-grade serous carcinoma. CCNE1 gene gains/amplifications were frequent in the p16 homogeneous/RB1+ subgroup (68%) and cyclin D1 protein overexpression was predominantly characteristic of the p16 heterogeneous/RB1+ subgroup. These subcategories occur early in tumor progression and are seen with similar frequency in the cancer precursor lesion, serous tubal intra-epithelial carcinoma. Overall, this study uniquely identifies multiple non-synonymous mechanisms of retinoblastoma pathway deregulation that correlate with significantly different clinical outcomes. Furthermore, deregulations identified in precursor lesions suggest a key role of this pathway in serous tumor development. Recognition of these categories may identify patients with increased sensitivity to chemotherapy and new opportunities for novel therapeutics.

Ovarian cancer: The fallopian tube as the site of origin and opportunities for prevention

High-grade serous carcinoma (HGSC) is the most common and aggressive histotype of epithelial ovarian cancer (EOC), and it is the predominant histotype associated with hereditary breast and ovarian cancer syndrome (HBOC). Mutations in BRCA1 and BRCA2 are responsible for most of the known causes of HBOC, while mutations in mismatch repair genes and several genes of moderate penetrance are responsible for the remaining known hereditary risk. Women with a history of familial ovarian cancer or with known germline mutations in highly penetrant genes are offered the option of risk-reducing surgery that involves the removal of the ovaries and fallopian tubes (salpingo-oophorectomy). Growing evidence now supports the fallopian tube epithelia as an etiological site for the development of HGSC and consequently, salpingectomy alone is emerging as a prophylactic option. This review discusses the site of origin of EOC, the rationale for risk-reducing salpingectomy in the high-risk population, and opportunities for salpingectomy in the low-risk population.

New biological research and understanding of Papanicolaou's test

The development of the Papanicolaou smear test by Dr. George Nicholas Papanicolaou (1883‐1962) is one of the most significant achievements in screening for disease and cancer prevention in history. The Papanicolaou smear has been used for screening of cervical cancer since the 1950s. The test is technically straightforward and practical and based on a simple scientific observation: malignant cells have an aberrant nuclear morphology that can be distinguished from benign cells. Here, we review the scientific understanding that has been achieved and continues to be made on the causes and consequences of abnormal nuclear morphology, the basis of Dr. Papanicolaous invention. The deformed nuclear shape is caused by the loss of lamina and nuclear envelope structural proteins. The consequences of a nuclear envelope defect include chromosomal numerical instability, altered chromatin organization and gene expression, and increased cell mobility because of a malleable nuclear envelope. HPV (Human Papilloma Virus) infection is recognized as the key etiology in the development of cervical cancer. Persistent HPV infection causes disruption of the nuclear lamina, which presents as a change in nuclear morphology detectable by a Papanicolaou smear. Thus, the causes and consequences of nuclear deformation are now linked to the mechanisms of viral carcinogenesis, and are still undergoing active investigation to reveal the details. Recently a statue was installed in front of the Papanicolaous Cancer Research Building to honor the inventor. Remarkably, the invention nearly 60 years ago by Dr. Papanicolaou still exerts clinical impacts and inspires scientific inquiries.

Presentation, Treatment, and Outcomes of Haitian Women With Breast Cancer in Miami and Haiti: Disparities in Breast Cancer—A Retrospective Cohort Study

Purpose We compared a cohort of Haitian immigrants with residents in Haiti with breast cancer (BC) to evaluate the effects of location on presentation, treatment, and outcomes. Patients and Methods Participants were Haitian women with BC living in Miami who presented to the University of Miami/Jackson Memorial Hospital and women with BC living in Haiti who presented to the Innovating Health International Women’s Cancer Center. The primary outcome was the relationship between location, cancer characteristics, and survival. The secondary objective was to compare our results with data extracted from the SEER database. Cox regression was used to compare survival. Results One hundred two patients from University of Miami/Jackson Memorial Hospital and 94 patients from Innovating Health International were included. The patients in Haiti, compared with the patients in Miami, were younger (mean age, 50.2 v 53.7 years, respectively; P = .042), presented after a longer duration of symptoms (median, 20 v 3 months, respectively; P < .001), had more advanced stage (44.7% v 25.5% with stage III and 27.6% v 18.6% with stage IV BC, respectively), and had more estrogen receptor (ER) –negative tumors (44.9% v 26.5%, respectively; P = .024). The percentage of women who died was 31.9% in Haiti died compared with 17.6% in Miami. Median survival time was 53.7 months for women in Haiti and was not reached in Miami. The risk of death was higher for women in Haiti versus women in Miami (adjusted hazard ratio, 3.09; P = .0024). Conclusion Women with BC in Haiti experience a significantly worse outcome than immigrants in Miami, which seems to be related to a more advanced stage and younger age at diagnosis, more ER-negative tumors, and lack of timely effective treatments. The differences in age and ER status are not a result of access to care and are unexplained.

Abstract C27: Breast cancer presentation in a cohort of Afro-American women and Afro-Caribbean women diagnosed at University of Miami/Jackson Memorial Hospital

Background: It is documented that socioeconomic factors, such as lack of access to health care and inadequate treatment after diagnosis contribute to disparities in breast cancer, but these factors alone do not explain breast cancer disparities. Several studies suggest that several other factors, such as environmental, biological and behavioral factors may play a significant role in the observed disparities in breast cancer outcomes in women in minorities. In this study we compare Afro-Caribbean (AC) women born in the Caribbean and living in the United States and Afro-American (AA) women born and living in the United States, with a diagnosis of breast cancer in order to evaluate the effect of immigration and place of residency. Methods: We conducted a retrospective chart review study of black women of AA and AC origin diagnosed with breast cancer at University of Miami/Jackson Memorial Hospital between 2005 and 2015 (n = 745). For each of the groups, we collected demographic data including age, body mass index (BMI), menopausal state, and TNM stage, receptor expression of estrogen and progesterone, Her-2/neu expression, gravidity and parity. Continuous data were analyzed using independent samples t-tests when parametric and using Wilcoxon-Mann-Whitney tests when non-parametric; categorical and binary data were analyzed using Chi-squared tests. Results: We analyzed data from 745 black female patients: AA (n = 281) AC (n = 422). Place of birth was not available for 42 women. Mean age was 54.9 and 53.7 in AC and AA women, respectively. AA women had higher BMI (32.1 vs 29.8, p = 0.0001), lower proportion of HER2 positive breast cancer (12% vs 19%, p = 0.027) and more children (3.1 vs 2.8, p = 0.023) than AC. There was no difference in age (54.9 vs 53.7), premenopausal status (33% vs 31%), stage 3 or 4 (38% vs 37%), ER+ (63% vs 62%) or triple negative breast cancer (27% vs 31%) in AC compared with AA women (Table 1). Conclusion: Jackson Memorial Hospital is a Safety-Net hospital for the 2.4 million residents of Miami-Dade County. The average age of our cohort was 54 years, ER 63% positive, Stage 3 was 27% and triple negative breast cancer was 29%. Compared to SEER data, our patients developed breast cancer one decade earlier, had a higher rate of triple negative breast cancer and higher stage at presentation. This was not affected by immigration status although the AC women were thinner and had fewer children. Citation Format: Rochelle Marill, Keren Braithwaite, Jorge Monge, Diana Byrnes, Sophia George, Judith Hurley. Breast cancer presentation in a cohort of Afro-American women and Afro-Caribbean women diagnosed at University of Miami/Jackson Memorial Hospital. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr C27.