Tumor-associated macrophages (TAMs) play a role in tumor angiogenesis and are recruited into the tumor microenvironment (TME) by secreted chemokines, including Monocyte Chemoattractant Protein-1 (MCP-1/CCL2). Angiogenesis is required to sustain proliferation and enable metastasis of breast cancer (BCa) cells. Understanding the underlying mechanisms of TAM recruitment would allow for the identification of desperately needed novel drug targets. Sushi Domain Containing 2 (SUSD2), a transmembrane protein on BCa cells, was previously shown to promote tumor angiogenesis in a murine model. To identify the role of SUSD2 in angiogenesis, 175 human breast tumors were surveyed by immunohistochemical analysis for the presence of SUSD2 and macrophages. Tumors with high levels of SUSD2 staining contained 2-fold more TAMs, mainly of the M2 pro-angiogenic phenotype. An in vitro co-culture model system was developed by differentiating SC monocytes into SC M0 macrophages. A 2-fold increase in polarized M2 macrophages was observed when M0 macrophages were incubated with SUSD2-expressing BCa cells compared to cancer cells that do not contain SUSD2. Since MCP-1 is known to recruit macrophages, levels of MCP-1 were compared between SUSD2-expressing MDA-MB-231 and MBA-MB-231-vector control cell lines. MCP-1 RNA, intracellular protein and secreted MCP-1 were all significantly increased compared to the vector control. Knockdown of SUSD2 in SKBR3 resulted in significantly decreased levels of secreted MCP-1. Consistently, increased levels of MCP-1 were observed in Susd2-expressing tumors generated from an in vivo isogeneic mouse model compared to the vector control tumors. Because SUSD2 recruits macrophages into the TME and promotes M2 polarization, inhibiting the function of SUSD2 may be an effective therapy for breast cancer patients.

The purpose of this study is to compare the rate of vaginal cuff dehiscence between two different methods of closure in patients undergoing robotic-assisted total laparoscopic hysterectomy and explore variables related to postoperative breakdown. This was a prospective, randomized controlled study with two arms. The control group (Arm 1) underwent single-layer continuous closure while the study group (Arm 2) had three additional imbricating figure-of-X sutures placed in addition to the standard protocol. Of the 263 patients who completed the study, 4 patients (1.49 %) experienced dehiscence of the vaginal cuff. Three of the four patients with dehiscence received the standard single vaginal cuff closure (Arm 1) and the one remaining case of dehiscence underwent the protocol with additional sutures (Arm 2). All patients who experienced dehiscence were current smokers. Our study suggests that there may be benefit in adding additional sutures to the standard single-layer vaginal cuff closure procedure. Physicians should evaluate smoking status before deciding on a vaginal cuff closure method.

Despite research in therapeutic strategies, ovarian cancer (OvCa) remains the most lethal gynecologic malignancy. The anatomical location of the ovaries within the peritoneal cavity facilitates metastasis by allowing tumor cells sloughed from the main tumor on the ovary to bind to the peritoneum or organs within the peritoneal cavity. These tumor cells are released from the main tumor either as single cells or as spheroids, the latter of which have been shown to be more effective at metastasizing and invading into the mesothelial lining. To identify novel tumor markers and therapeutic targets for epithelial cancers, a cDNA library enriched for cancer genes that encode membrane and secreted proteins was generated. The 18th most abundant gene represented in this library was Sushi Domain Containing 2 (SUSD2), which encodes an 822 amino acid membrane surface protein. To begin defining the role of SUSD2 in OvCa, stable SUSD2-expressing and vector control A2780 cell lines were generated. To examine whether SUSD2 affects the growth of OvCa cells, cellular proliferation assays were performed. There was no significant difference in growth rates with SUSD2 over-expression compared to the vector control cell lines. A Boyden chamber assay was performed to analyze the effect of SUSD2 on cell migration. A2780-SUSD2 cell lines and vector-only controls were plated on membranes and allowed to migrate toward a chemoattractant in a lower chamber. SUSD2 over-expression significantly increased migration by greater than 2-fold. In addition, a scratch wound-healing assay was performed, and after 24 hours the A2780-SUSD2 cell line had 2-fold more cells within the wound compared to the A2780-vector control cells (P<0.05). Consistently, agarose beads containing either A2780-SUSD2 or vector cells were grown in chemoattractant containing media. The distance the escaped cells traveled from the bead was measured. A2780-SUSD2 cells traveled farther away from the bead compared to the vector control (717 μm compared to 125 μm, respectively, P<0.05). Spheroid-forming ability was analyzed, and A2780-SUSD2 cells formed smaller and looser spheroids (length and width average of 933 μm) compared to A2780-vector control cells (length and width average of 1237 μm, P=0.025). To correlate OvCa patient outcome with the presence of SUSD2 in the corresponding tumor, a tissue microarray containing high-grade ovarian serous carcinoma core samples from 128 patients was stained with an anti-SUSD2 antibody. The intensity of SUSD2 staining was scored by a pathologist, and results were correlated with patient outcome. A Kaplan-Meier curve indicated a significant separation for patients with low SUSD2 levels, median survival 31.7 months, versus patients with strong SUSD2 staining, median survival 49.1 months (P=0.0083). This data suggests that low SUSD2 levels in OvCa tumors are associated with a poorer prognosis for the patient. Our in vitro assays indicate that expression of SUSD2 in A2780 cells increased the ability of the cells to migrate and caused the formation of smaller spheroids. Because spheroids are better able to resist chemotherapy and invade the mesothelium, the decreased spheroid size of SUSD2-expressing cells may allow for a better patient prognosis. Citation Format: Jennifer A. A. Gubbels, Elizabeth M. Hultgren, Jessica Johnson, Emily Johnson, Jeffrey Sachs, Michelle S. Hirsch, Joyce Liu, Ronny Drapkin, Kristi A. Egland. Expression of Sushi Domain Containing 2 (SUSD2) in high-grade ovarian serous carcinoma correlated with increased longevity of patients. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A71.