Rashna Madan

Changes in O-Linked N-Acetylglucosamine (O-GlcNAc) Homeostasis Activate the p53 Pathway in Ovarian Cancer Cells

O-GlcNAcylation is a dynamic post-translational modification consisting of the addition of a single N-acetylglucosamine sugar to serine and threonine residues in proteins by the enzyme O-linked β-N-acetylglucosamine transferase (OGT), whereas the enzyme O-GlcNAcase (OGA) removes the modification. In cancer, tumor samples present with altered O-GlcNAcylation; however, changes in O-GlcNAcylation are not consistent between tumor types. Interestingly, the tumor suppressor p53 is modified by O-GlcNAc, and most solid tumors contain mutations in p53 leading to the loss of p53 function. Because ovarian cancer has a high frequency of p53 mutation rates, we decided to investigate the relationship between O-GlcNAcylation and p53 function in ovarian cancer. We measured a significant decrease in O-GlcNAcylation of tumor tissue in an ovarian tumor microarray. Furthermore, O-GlcNAcylation was increased, and OGA protein and mRNA levels were decreased in ovarian tumor cell lines not expressing the protein p53. Treatment with the OGA inhibitor Thiamet-G (TMG), silencing of OGA, or overexpression of OGA and OGT led to p53 stabilization, increased nuclear localization, and increased protein and mRNA levels of p53 target genes. These data suggest that changes in O-GlcNAc homeostasis activate the p53 pathway. Combination treatment of the chemotherapeutic cisplatin with TMG decreased tumor cell growth and enhanced cell cycle arrest without impairing cytotoxicity. The effects of TMG on tumor cell growth were partially dependent on wild type p53 activation. In conclusion, changes in O-GlcNAc homeostasis activate the wild type p53 pathway in ovarian cancer cells, and OGA inhibition has the potential as an adjuvant treatment for ovarian carcinoma.

PTN signaling: Components and mechanistic insights in human ovarian cancer

Molecular vulnerabilities represent promising candidates for the development of targeted therapies that hold the promise to overcome the challenges encountered with non‐targeted chemotherapy for the treatment of ovarian cancer. Through a synthetic lethality screen, we previously identified pleiotrophin (PTN) as a molecular vulnerability in ovarian cancer and showed that siRNA‐mediated PTN knockdown induced apoptotic cell death in epithelial ovarian cancer (EOC) cells. Although, it is well known that PTN elicits its pro‐tumorigenic effects through its receptor, protein tyrosine phosphatase receptor Z1 (PTPRZ1), little is known about the potential importance of this pathway in the pathogenesis of ovarian cancer. In this study, we show that PTN is expressed, produced, and secreted in a panel of EOC cell lines. PTN levels in serous ovarian tumor tissues are on average 3.5‐fold higher relative to normal tissue and PTN is detectable in serum samples of patients with EOC. PTPRZ1 is also expressed and produced by EOC cells and is found to be up‐regulated in serous ovarian tumor tissue relative to normal ovarian surface epithelial tissue (P < 0.05). Gene silencing of PTPRZ1 in EOC cell lines using siRNA‐mediated knockdown shows that PTPRZ1 is essential for viability and results in significant apoptosis with no effect on the cell cycle phase distribution. In order to determine how PTN mediates survival, we silenced the gene using siRNA mediated knockdown and performed expression profiling of 36 survival‐related genes. Through computational mapping of the differentially expressed genes, members of the MAPK (mitogen‐activated protein kinase) family were found to be likely effectors of PTN signaling in EOC cells. Our results provide the first experimental evidence that PTN and its signaling components may be of significance in the pathogenesis of epithelial ovarian cancer and provide a rationale for clinical evaluation of MAPK inhibitors in PTN and/or PTPRZ1 expressing ovarian tumors.

Utility of peritoneal washing cytology in staging and prognosis of ovarian and fallopian tube neoplasms: a 10-year retrospective analysis

The prognostic significance of peritoneal washing cytology in gynecologic neoplasms is controversial. The presence of neoplastic cells in peritoneal washings is currently part of the Federation of Gynecology and Obstetrics and American Joint Committee on Cancer TNM staging systems in cases of ovarian and fallopian tube neoplasms without metastasis beyond the pelvis. In this study, we retrospectively reviewed all cases of ovarian and fallopian tube neoplasms in which cytologic studies were performed. The utility of cytology in tumor staging and the relationship between cytology results and patient outcome are studied. All cases of ovarian and fallopian tube neoplasms in our institution between July 2002 and July 2012 were reviewed. Primary tumor characteristics including type and pelvic extension were collected, categorized, and correlated with peritoneal washing cytology. Final tumor staging was reviewed and the impact of positive cytology was evaluated. A total of 120 cases of ovarian and fallopian tube neoplasms without extrapelvic metastasis were identified within the study period. Peritoneal washing cytology was positive in 24% (29/120) of neoplasms and upstaged the tumor 83% (24/29) of the time when positive. Overall, 20% (24/120) of reviewed cases were upstaged based on positive cytology results. Peritoneal washing cytology remains a useful staging tool for ovarian and fallopian tube neoplasms limited to the pelvic cavity. Positive cytology results in upstaging in a significant proportion of the cases regardless of the tumor type. A larger study is needed to analyze follow-up data to determine if upstaging based on positive cytology adversely affects outcome.

Late-Onset Intestinal Perforation in the Setting of Posttransplantation Microangiopathy: A Case Report

Intestinal perforation in the setting of posttransplantation microangiopathy (TMA) is a very rare event and might be considered a terminal event of intestinal microangiopathy (i-TMA), a rather rarely recognized posttransplantation complication, as it overlaps with the more common intestinal graft-versus-host disease (GVHD). Cases of i-TMA described in literature occurred within with first 100 days posttransplantation or shortly thereafter. In this report, we describe a case of late-onset intestinal perforation that occurred in the setting of systemic microangiopathy more than a year after allogeneic transplantation. In our case, the patient poorly responded to treatment secondary to refractory mircoangiopathy.

Pancreatic cystic lesions without overt cytologic atypia: proposed diagnostic categories for endoscopic ultrasound-guided fine-needle aspiration cytology with utilization of fluid carcinoembryonic antigen level.

Objectives: It was the aim of this study to examine pancreatic cyst cases that lack markedly atypical or malignant epithelium on endoscopic ultrasound-guided fine-needle aspirations. Study Design: We conducted a retrospective case review study, including 24 cases that were either acellular or lacked cytologic atypia and were subsequently resected. The cases were retrospectively divided into 3 categories: (1) non-diagnostic, (2) cyst contents only, and (3) cyst contents with bland-appearing epithelium. The cyst contents were subdivided into mucinous and non-mucinous types. The cytologic diagnoses were correlated with cyst fluid carcinoembryonic antigen (CEA) levels and subsequent histologic diagnoses. Results: Category 1 comprised 4 cases: 2 cases (CEA >800 ng/ml) with mucin-producing neoplasms and 2 cases (CEA not determined) with microcystic serous cystadenomas. Category 2 included 4 cases with non-mucinous and 4 with mucinous contents. In the first subgroup, 2 cases (CEA >800 ng/ml) showed mucinous cystic neoplasms and 2 cases (CEA negligible or not determined) pseudocysts. In the second subgroup, there were 3 cases with neoplastic mucinous cysts (1 CEA >800 ng/ml, 2 not determined) and 1 case with a lymphoepithelial cyst with mucinous metaplasia (CEA >800 ng/ml). Almost all cases (10/11) in category 3 had neoplastic mucinous cysts regardless of the CEA levels. Conclusions: The proposed 3 cytologic categories of pancreatic cystic lesion combined with cyst fluid CEA levels provide useful clinical information.

Intestinal ischemia after allogeneic stem cell transplantation: a report of four cases.

Gastrointestinal ischemia after allogeneic bone marrow transplantation is a rare complication not well-described in the literature. Herein we retrospectively review charts of four patients who developed intestinal ischemia after allogeneic bone marrow transplantation at our institution. The patients were found to be predominately younger males who presented with nonspecific abdominal pain. Graft-versus-host disease was a common finding among all patients. Laboratory values suggestive of microangiopathy were present in two patients. Obesity and hypertriglyceridemia were cardiovascular risk factors found in these patients. The development of thrombotic microangiopathy and cardiovascular risk factors after allogeneic bone marrow transplantation may predispose patients to gastrointestinal ischemia and may portend a poor prognosis.

O-GlcNAc-Dependent Regulation of Progesterone Receptor Function in Breast Cancer

Emerging clinical trial data implicate progestins in the development of breast cancer. While the role for the progesterone receptor (PR) in this process remains controversial, it is clear that PR, a steroid-activated nuclear receptor, alters the transcriptional landscape of breast cancer. PR interacts with many different types of proteins, including transcriptional co-activators and co-repressors, transcription factors, nuclear receptors, and proteins that post-translationally modify PR (i.e., kinases and phosphatases). Herein, we identify a novel interaction between PR and O-GlcNAc transferase (OGT), the enzyme that catalyzes the addition of a single N-acetylglucosamine sugar, referred to as O-GlcNAc, to acceptor serines and threonines in target proteins. This interaction between PR and OGT leads to the post-translational modification of PR by O-GlcNAc. Moreover, we show that O-GlcNAcylated PR is more transcriptionally active on PR-target genes, despite the observation that PR messenger RNA and protein levels are decreased when O-GlcNAc levels are high. O-GlcNAcylation in breast cancer is clinically relevant, as we show that O-GlcNAc levels are higher in breast cancer as compared to matched normal tissues, and PR-positive breast cancers have higher levels of OGT. These data predict that under conditions where O-GlcNAc levels are high (breast cancer), PR, through an interaction with the modifying enzyme OGT, will exhibit increased O-GlcNAcylation and potentiated transcriptional activity. Therapeutic strategies aimed at altering cellular O-GlcNAc levels may have profound effects on PR transcriptional activity in breast cancer.

Metastatic Papillary Renal Cell Carcinoma Regression After Cytoreductive Nephrectomy

CASE PRESENTATION previously healthy 69-year-old woman sought medical attention for stomach pain and distenAsion associated with a 10-pound weight loss. There was no hematuria, fevers, chills, night sweats, or fatigue. Past medical history was significant for hypertension. In 1989, she required a temporary colostomy after a partial colectomy secondary to a colonic perforation. Family history was significant for a brother with glioblastoma multiforme, and her mother had kidney disease of unknown etiology. She did not report any previous chemical exposure but is a current smoker with a 45-pack year history of tobacco abuse. Initial kidney, ureter, and bladder imaging was done and suggested constipation. Pain control was achieved with an aggressive bowel regimen and pain medication, but the sensation of abdominal fullness persisted. On presentation to our clinic, vital signs were normal except for a 10-pound weight loss over a 3-week period. Physical examination revealed a left large, palpable, flank mass that was tender to palpation but no other palpable adenopathy. Her initial laboratory evaluation was significant for hemoglobin 10.3 g/dL, creatinine 1.17 mg/dL, calcium 10.0 mg/dL, albumin 4.0 g/dL, and lactate dehydrogenase 543 U/L (100-210 U/L). A computed tomography scan of the abdomen and pelvis followed by magnetic resonance imaging (MRI) of the abdomen revealed a 13.6 11.6 9.9 cm heterogeneous left renal mass (Fig. 1) with bulky retroperitoneal lymphadenopathy, left renal vein thrombus, a nonocclusive inferior vena caval tumor thrombus, ipsilateral adrenal gland

Metastatic gastrinoma in the breast mimicking primary solid papillary carcinoma

We report a case of metastatic gastrinoma to the breast morphologically mimicking solid papillary carcinoma of the breast. A 59-year-old woman presented with a hypoechoic right breast mass that histologically revealed solid nests of small monotonous tumor cells, fibrovascular cores, and round to oval nuclei with fine chromatin and small nucleoli. Immunohistochemistry demonstrated chromogranin and synaptophysin positivity. Tumor prognostic markers showed weak positivity for estrogen receptor and negativity for progesterone receptor. Although an initial diagnosis of solid papillary carcinoma was rendered, subsequent identification of the patients clinical history of pancreatic gastrinoma and an additional immunohistochemical stain for gastrin supported a diagnosis of metastatic gastrinoma. We report this rare case to increase awareness of metastatic neuroendocrine tumors in the breast. Multiple breast lesions and lack of expression of estrogen/progesterone hormone receptors should prompt careful review of the patients clinical history to rule out metastatic neuroendocrine disease.

Endoscopic Ultrasound Diagnosis of Perianal Rhabdomyosarcoma

A 27-year-old male with no significant past medical history, presented to the emergency room with symptoms of perianal pain. Additionally, the patient complained of cramps in his legs and buttocks for approximately one month. The cramps were initially minor but progressively worsened and then became constant. His vitals and physical examination were normal except for his digital rectal examination, which was painful and tender. However, no obvious mass was felt in the rectum. His initial blood tests were unremarkable which included hemoglobin-14 g/dl (Nv-13.5-16.5), white cell count-8.9 (Nv-4.5-11), platelets-324 (Nv-150400), blood urea nitrogen-12 (Nv-7-25), creatinine 1.2 (Nv-0.4-1.24), sodium-140 (Nv-137145) and potassium of 3.7 (Nv-3.5-5.1). Pelvic Computed Tomography (CT) (Figure 1) showed a mass in the perianal region measuring 12 cm with metastasis to the left iliac and obturator lymph nodes. In view of the CT findings, other lab tests like Carcinoembryonic antigen (CEA)0.5 (Nv-<3 ng/ml), CA 19-9-10 (Nv-<35 u/ml), Human Immunodeficiency Virus (HIV), Human papillomavirus (HPV) and Chlamydia were checked and were all within normal range. The patient then underwent lower EUS, which showed a 5 cm hypoechoic mass (Figure 2) just outside the anal canal. An FNA was obtained which showed neoplastic cells (Figure 3A). The cells were largely mononuclear, with a few binucleate and multinucleate cells. These cells had a high nuclear cytoplasmic ratio with a relatively round nucleus. Immunohistochemical stain was positive for muscle (desmin) and more precisely for striated muscle (myogenin, Figure 3B), supporting the diagnosis of Rhabdomyosarcoma. Subsequent Fluorescent in situ hybridization (FISH) performed using DNA probe specific for the FOXO1 (FKHR) gene on 13q14 showed a signal pattern suggestive of rearrangement of FOXO1 gene. Rearrangement of FOXO1 is associated with a diagnosis of Alveolar Rhabdomyosarcoma. Unfortunately, the patient was a poor candidate for curative treatment due to the presence of distal metastasis. However, he underwent adjuvant chemotherapy and radiation therapy for treatment of his cancer.