Gabriela Oprea

Aberrant STYK1 expression in ovarian cancer tissues and cell lines

BackgroundOverexpression of STYK1, a putative serine/threonine and tyrosine receptor protein kinase has been shown to confer tumorigenicity and metastatic potential to normal cells injected into nude mice. Mutation of a tyrosine residue in the catalytic STYK1 domain attenuates the tumorigenic potential of tumor cells in vivo, collectively, suggesting an oncogenic role for STYK1.MethodsTo investigate the role of STYK1 expression in ovarian cancer, a panel of normal, benign, and ovarian cancer tissues was evaluated for STYK1 immunoreactivity using STYK1 antibodies. In addition, mRNA levels were measured by reverse transcription PCR and real-time PCR of estrogen receptors, GPR30 and STYK1 following treatment of ovarian cell lines with estrogen or G1, a GPR30 agonist, as well as western analysis.ResultsOur data showed higher expression of STYK1 in cancer tissues versus normal or benign. Only normal or benign, and one cancer tissue were STYK1-negative. Moreover, benign and ovarian cancer cell lines expressed STYK1 as determined by RT-PCR. Estradiol treatment of these cells resulted in up- and down-regulation of STYK1 despite estrogen receptor status; whereas G-1, a GPR30-specific agonist, increased STYK1 mRNA levels higher than that of estradiol.ConclusionWe conclude that STYK1 is expressed in ovarian cancer and is regulated by estrogen through a GPR30 hormone-signaling pathway, to the exclusion of estrogen receptor-alpha.

c-kit EXPRESSION IN ADENOID CYSTIC CARCINOMA DOES NOT HAVE AN IMPACT ON LOCAL OR DISTANT TUMOR RECURRENCE

Adenoid cystic carcinoma (ACC) is a neoplasm with unpredictable behavior with frequent late relapses that lacks good prognostic indicators. c‐kit tyrosine kinase oncogene has recently been found to be expressed in ACC. The aim of this study is to correlate the expression of c‐kit in ACC with clinical follow‐up.

Case Report on a 21 Years Old Female Patient with Acute Pancreatitis in Cystic Fibrosis

Acute pancreatitis is a rare complication in patients with cystic fibrosis. We present a case of a young female with a history of bronchiectasis and Bartter syndrome, who was admitted in our hospital with an acute episode of pancreatitis. We had diagnosed the case as acute pancreatitis, but we did not have a cause for it. She denied drinking alcohol, or consuming drugs. Abdominal trauma was not reported. There was no stone or sludge in the gallbladder and biliary ducts, no malformation on the biliary ducts, and no dyslipidemia. As, the patient had a history of bronchiectasis and Bartter syndrome; we had to look for cystic fibrosis and therefore, we recommended the sweat test and genetic tests. The results obtained for heterozygote M 2183AA>G: 7T, 9T and the sweat test were positive. However, the genetic analyses of her parents could not be performed. We concluded the diagnosis as acute pancreatitis due to cystic fibrosis modifications. The patient was also pancreatic sufficient (the evaluation of exocrine pancreatic function was in normal ranges).

Abstract B33: BRCA1 RING domain mutations and function-based tools to predict risk for the development of TNBC

Breast cancer is the second leading cause of cancer-related deaths amongst women with 231,840 new cases projected for 2015. Majority of young African American women with BRCA1 mutations have a so-called Triple negative breast cancer with an aggressive phenotype. Currently there is no targeted therapy for TNBC. BRCA1 encodes a large protein and the two highly conserved regions are located at both ends, an N-terminal RING domain and two BRCT repeats at the C-terminus. The RING domain through interaction with BARD1 contains E3 ubiquitin ligase activity. Various BRCA1 mutations have been found throughout BRCA1 coding region, but the majority of cancer-associated mutations are nonsense or frame shift mutations which lead to chain termination. The C61G mutation has been linked to both breast and ovarian cancer development. In people from Ashkenazi Jewish descent, the most common mutations are 185delAG and 5382 ins C in BRCA1 and is 1:40. Our lab has cloned two naturally occurring splice variants of BRCA1 (BRCA1a and BRCA1b). These isoforms are the most evolutionary conserved of all the splice variants and code for multifunctional proteins. Our group has previously reported that BRCA1 RING domain, unlike K109R and cancer-predisposing mutant C61G BRCA1 proteins interact with the sole SUMO E2-conjugating enzyme Ubc9 and this facilitates both the entry of BRCA1 proteins to the nucleus and mediates ubiquitination of ER-alpha. The disease associated mutants do not bind Ubc9, remain stalled in the cytoplasm and have lost their growth suppressor function. We have identified a new nuclear trafficking pathway and malfunction of this by BRCA1 dysfunction can result in TNBC. The BARD1-dependent -E3 ubiquitin ligase activity of BRCA1 has been predicted to be required for its tumor suppressor function, as certain cancer –associated mutations in BRCA1 RING domain ablate this activity. Several mutations in BRCA1 RING domain have been identified however; their role in TNBC has yet to be elucidated. This work is based on the hypothesis that BRCA1 is a tumor suppressor gene and its RING domain can harbor several mutations some of which can result in loss of BRCA1 function resulting in TNBC and others can be gain of function mutants similar to WT BRCA1. We tested this hypothesis by introducing C61G, K109R and I26A mutations into TNBC cells and studied their growth inhibitory activity using colony suppression assays. Our results demonstrate for the first time that BRCA1 I26A to be a gain of function mutant similar to WT BRCA1. I26A mutant associates with Ubc9, lacks E3 ubiquitin ligase activity and suppresses growth of BRCA1 mutant TNBC and sporadic TNBC cells unlike K109R and C61G mutants. Clinically, the ability to predict which of these mutations can result in TNBC offers unprecedented prospects for early detection and cancer prevention. This is the first study demonstrating the physiological link between Ubc9 binding, loss of BARD1- dependent E3 ubiquitin ligase activity and growth suppression of I26A mutant BRCA1 protein in TNBC cells. BRCA1, by turning off or on Ubc9 binding, regulates growth of TNBC. This study will accelerate precision medicine and reduce cancer health disparities in health outcomes. Work supported in part by Georgia Cancer Coalition Distinguished Cancer Scholar award, NIH-NCRR-RCMI grant G-12-RR003034, U54 RR02613, 5P20RR11104 and NIHMD research endowment grant 2S21MD000101, MSM/TU/UAB CCC Partnership/U54 CA118638 and ING foundation to V.N.R. Patent issued No:8372,580; 2013. Citation Format: Jingyao Xu, Shanekkia Black, Kartik Aysola, Yunlong Qin, Vaishali Reddy, Karan Singh, Joel Okoli, Derrick Beech, Uma Krishnamurthy, Gabriela Oprea, Valerie M. Rice, E Shyam Reddy, Douglas Moellering, Yuchang Fu, Veena N. Rao. BRCA1 RING domain mutations and function-based tools to predict risk for the development of TNBC. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B33.