Uterine serous carcinoma (USC) is a biologically aggressive subtype of endometrial cancer. We analyzed the mutational landscape of USC by whole-exome sequencing of 57 cancers, most of which were matched to normal DNA from the same patients. The distribution of the number of protein-altering somatic mutations revealed that 52 USC tumors had fewer than 100 (median 36), whereas 5 had more than 3,000 somatic mutations. The mutations in these latter tumors showed hallmarks of defects in DNA mismatch repair. Among the remainder, we found a significantly increased burden of mutation in 14 genes. In addition to well-known cancer genes (i.e., TP53, PIK3CA, PPP2R1A, KRAS, FBXW7), there were frequent mutations in CHD4/ Mi2b, a member of the NuRD-chromatin-remodeling complex, and TAF1, an element of the core TFIID transcriptional machinery. Additionally, somatic copy-number variation was found to play an important role in USC, with 13 copy-number gains and 12 copy-number losses that occurred more often than expected by chance. In addition to loss of TP53, we found frequent deletion of a small segment of chromosome 19 containing MBD3, also a member of the NuRDchromatin-modification complex, and frequent amplification of chromosome segments containing PIK3CA, ERBB2 (an upstream activator of PIK3CA), and CCNE1 (a target of FBXW7-mediated ubiquitination). These findings identify frequent mutation of DNA damage, chromatin remodeling, cell cycle, and cell proliferation pathways in USC and suggest potential targets for treatment of this lethal variant of endometrial cancer.endometrial carcinoma | uterine serous papillary cancer | cancer genomics E ndometrial cancer is the most prevalent gynecologic tumor in women, with an annual incidence of 47,130 new cases and 8,010 deaths in 2012 in the United States (1). On the basis of clinical and histopathological features, endometrial cancer is classified into type I and type II disease groups (2). Type I tumors, which constitute the majority of cases, are generally diagnosed at an early stage, are low grade and endometrioid in histology, are associated with a history of hyperestrogenism, and typically have a good prognosis. In contrast, type II cancers are poorly differentiated, often with serous papillary [uterine serous carcinoma (USC)] or clear cell histology. Although these tumors account for a minority of endometrial cancers, the majority of relapses and deaths occur in this group of patients (2).Among type II cancers, USC represents the most biologically aggressive subtype (3, 4). Classically, the neoplastic epithelium is characterized by serous differentiation with psammoma bodies and a predominantly papillary architecture (3). Pleomorphic cytology with nuclear atypia, prominent nucleoli, a vescicular chromatin pattern, and high mitotic activity are seen. Clinically, USC has a propensity for early intra-abdominal and lymphatic spread (3) and is more commonly diagnosed in women of African ancestry (3-5). The overall 5-y survival of USC is only 30 ± 9% for all stages, and the recurre...

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Objective We evaluated the expression of human trophoblast cell-surface marker (Trop-2) and the potential of hRS7, a humanized monoclonal anti-Trop-2 antibody, as a therapeutic agent against chemotherapy-resistant ovarian disease. Methods Trop-2 expression was evaluated by immunohistochemistry (IHC) in 50 ovarian serous papillary carcinoma specimens. Trop-2 expression was also evaluated by real-time PCR (qRT-PCR) and flow cytometry in a total of 6 primary ovarian cancer cell lines derived from patients with chemotherapy-resistant disease. Sensitivity to hRS7 antibody-dependent cellular cytotoxicity (ADCC) was tested in standard 5-hours 51Cr-release assays. The effect of serum and interleukin-2 (IL-2) on hRS7-mediated ADCC was also studied. Results Trop-2 expression was found in 41 of 50 (82%) tumor tissues tested by IHC. 83% (5 of 6) of the ovarian cancer cell lines tested by qRT-PCR and flow cytometry demonstrated high Trop-2 expression. All primary ovarian cancer cell lines expressing Trop-2 were highly sensitive to hRS7-mediated ADCC in vitro (range of killing: 19.3% to 40.8%) (p<0.001). Negligible cytotoxicity against chemotherapy-resistant ovarian cancers was seen in the absence of hRS7 or in the presence of rituximab control antibody (range of killing: 1.1% to 8.9%). Human serum did not significantly inhibit hRS7-mediated-cytotoxicity while incubation with IL-2 in addition to hRS7 further increased the cytotoxic activity (p=0.04). Conclusions Trop-2 is highly expressed in chemotherapy-resistant ovarian cancer cell lines at mRNA and protein levels. Primary ovarian carcinoma cell lines are highly sensitive to hRS7-mediated cytotoxicity in vitro. hRS7 may represent a novel therapeutic agent for the treatment of high-grade, chemotherapy-resistant ovarian cancer.

Carcinosarcomas of the female genital tract are rare tumors with aggressive clinical behavior. Trastuzumab, a humanized monoclonal antibody, acts by binding to HER2/neu extracellular domain and exhibits therapeutic efficacy in HER2/neu over-expressing cancers. Two uterine carcinosarcomas (UMMT-ARK-1, UMMT-ARK-2) and two ovarian carcinosarcomas (OMMT-ARK-1, OMMT-ARK-2) were established as primary tumor cell lines in vitro and evaluated for HER2/neu expression by immunohistochemistry (IHC), fluorescent-in-situ-hybridization-analysis (FISH), quantitative-real-time-polymerase-chain-reaction and for membrane-bound-complement-regulatory-proteins (mCRP) CD46, CD55 and CD59 by flow-cytometry. Sensitivity to trastuzumab-dependent-cell-mediated-cytotoxicity (ADCC) and complement-dependent-cytotoxicity (CDC) was studied in 5-hour-chromium-release-assays. HER2/neu expression was demonstrated in OMMT-ARK-1 and OMMT-ARK-2. OMMT-ARK-2 demonstrated amplification of the c-erbB2 gene by FISH and a high sensitivity to ADCC (mean killing 45.6%; range: 32.3–72.6%). Lower level of killing was detected against the FISH-negative OMMT-ARK-1 cell line (mean 26.5%; range: 21.0–31.8%). CD46, CD55 and CD59 mCRP were expressed at high levels in all primary MMT cell lines and all these tumors were found highly resistant to CDC with or without trastuzumab. Addition of untreated and heat-inactivated-plasma did not significantly decrease ADCC against OMMT-ARK-2 cell line suggesting that while the cell line is highly resistant to complement, irrelevant IgG do not significantly alter the ability of trastuzumab to mediate ADCC. Our results suggest that HER2/neu may represent a novel target for the immunotherapy of a subset of human carcinosarcomas refractory to salvage chemotherapy.