CCAR2 functions downstream of the Shieldin complex to promote double-strand break end-joining.

The 53BP1-RIF1 pathway restricts the resection of DNA double-strand breaks (DSBs) and promotes blunt end-ligation by non-homologous end joining (NHEJ) repair. The Shieldin complex is a downstream effector of the 53BP1-RIF1 pathway. Here, we identify a component of this pathway, CCAR2/DBC1, which is also required for restriction of DNA end-resection. CCAR2 co-immunoprecipitates with the Shieldin complex, and knockout of CCAR2 in a BRCA1-deficient cell line results in elevated DSB end-resection, RAD51 loading, and PARP inhibitor (PARPi) resistance. Knockout of CCAR2 is epistatic with knockout of other Shieldin proteins. The S1-like RNA-binding domain of CCAR2 is required for its interaction with the Shieldin complex and for suppression of DSB end-resection. CCAR2 functions downstream of the Shieldin complex, and CCAR2 knockout cells have delayed resolution of Shieldin complex foci. Forkhead-associated (FHA)-dependent targeting of CCAR2 to DSB sites re-sensitized BRCA1-/-SHLD2-/- cells to PARPi. Taken together, CCAR2 is a functional component of the 53BP1-RIF1 pathway, promotes the refill of resected DSBs, and suppresses homologous recombination.

Carcinosarcoma arising from high-grade serous carcinoma of the ovary without estrogen receptor, WT-1, and PAX8 immunoreactivity.

OBJECTIVE: We encountered a case of high-grade serous carcinoma (HGSC) of the ovary which recurred as carcinosarcoma of the sigmoid colon. Tumor cells of both the primary carcinoma and the secondary carcinosarcoma were negative for estrogen receptor (ER), WT-1, and PAX8. It is well known that most ovarian carcinomas arising from the Müllerian duct are immunoreactive for these biologic parameters. To our knowledge, this is the first case report that provides the results of immunohistochemical analysis of WT-1 and PAX8 for a primary carcinoma and recurrent carcinosarcoma. CASE REPORT: A 61-year-old woman had an advanced right ovarian HGSC. After a primary debulking surgery (hysterectomy, bilateral salpingo-oophorectomy and omentectomy) and adjuvant chemotherapy, complete remission was achieved. However, four and a half years later, a tumor arising beside the sigmoid colon was detected. A tumorectomy was performed through combined partial resection of the ileum and sigmoid colon. Microscopically, the tumor was diagnosed as carcinosarcoma of the sigmoid colon, which had originated from HGSC of the ovary. Interestingly, the malignant cells of the primary carcinoma and epithelial components of the recurrent carcinosarcoma were negative for ER, WT-1, and PAX8. These immunohistochemical features were unusual. Three cycles of chemotherapy with the previously used regimen and three additional cycles of doxorubicin and ifosfamide combination chemotherapy were administered. Currently, 3 years after the final chemotherapy was administered, the patient remains healthy. CONCLUSION: HGSC of the ovary can recur as carcinosarcoma. Tumor cells of the primary HGSC without ER, WT-1, and PAX8 expression may have dedifferentiated and recurred as carcinosarcoma.

Multiple metastatic gestational trophoblastic disease after a twin pregnancy with complete hydatidiform mole and coexisting fetus, following assisted reproductive technology: Case report and literature review.

OBJECTIVE: Twin pregnancy with complete hydatidiform mole and coexisting fetus (CHMCF) is rare and associated with severe complications during pregnancy and subsequent gestational trophoblastic disease (GTD). We encountered a case of multiple metastatic GTD after a twin pregnancy with CHMCF, following conventional in vitro fertilization (IVF). Only one case of metastatic GTD after CHMCF due to assisted reproductive technology (ART) has been reported. Here, we present the clinical course and reveal the clinical features of CHMCF after ART through a literature review. CASE REPORT: A 42-year-old primigravida woman had an abnormal pregnancy (i.e., CHMCF) by IVF. She had persisting severe vaginal bleeding, which led to termination of her pregnancy at 10 weeks of gestation. Pathohistological examination revealed that this was a case of CHMCF. Five weeks after the termination, the serum ß-human chorionic gonadotropin level was still extremely high, and systemic contrast-enhanced computed tomography revealed a tumor in the uterine corpus and more than 30 lung nodules. After 11 cycles of combination chemotherapy with etoposide, methotrexate, actinomycin-D, cyclophosphamide, and vincristine (EMA/CO) to treat high-risk GTD, hysterectomy was needed as radical therapy. CONCLUSION: Cases of CHMCF following ART may also have higher malignant potential and higher risk of GTD development and become more aggressive biologically. The clinical course of CHMCF after ART seems to be almost the same as that without ART based on the results of literature review.

Magnetic Resonance Imaging and Flexible Hysterofiberscopic Findings of a Uterine Adenofibroma: Case Report and Literature Review.

To our knowledge, highly detailed findings of flexible hysterofiberscopy in patients with adenofibroma have not been described. A 75-year-old nulliparous asymptomatic woman presented with a uterine polyp, which exhibited punctate heterogeneous hyperintensity or islands of isointense-to-hypointense signals on T2-weighted magnetic resonance imaging (MRI), hypointense signals on T1-weighted images (T1WI), and a little enhancement on contrast-enhanced T1WI. Flexible hysterofiberscopy revealed a red-pink polyp with a white-yellow, cobblestone-like surface easily deformed by perfusion fluid. The tumor was diagnosed histologically as an adenofibroma. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. The tumor in the uterus was necrotic macroscopically and histologically, and a residual adenofibroma could not be confirmed. At present, two years after surgery, the patient remains healthy. MRI and hysterofiberscopy can reveal the histological features of uterine adenofibromas and be useful for their diagnosis.

Synthesis and Biologic Evaluation of Novel 18F-Labeled Probes Targeting Prostate-Specific Membrane Antigen for PET of Prostate Cancer.

Prostate-specific membrane antigen (PSMA) is a membrane protein highly expressed on prostate cancer cells and a potential imaging target for diagnosis. 18F-DCFPyL has been recently developed as an effective probe with high diagnostic accuracy for prostate cancer imaging. However, its radiochemical yield is low. We developed new PSMA probes using succinimidyl 4-18F-fluorobenzoate (18F-SFB), a rapid and effective 18F-labeling agent, taking advantage of the high radiochemical yield of this compound. We evaluated the probes as PET probes for PSMA imaging. METHODS: Four 18F-labeled probes, 18F-8a, 18F-8b, 18F-10a, and 18F-10b, were synthesized using 18F-SFB, and their affinity for PSMA and partition coefficients (log D) were evaluated in vitro. Biodistribution studies were performed in human prostate cancer xenograft-bearing mice. PET images were obtained using 2 compounds, 18F-8a and 18F-10a, and a toxicologic study of 18F-10a was performed. RESULTS: Four 18F-labeled asymmetric urea compounds, conjugated with 18F-SFB, were synthesized at a radiochemical yield of 30%-50% (decay-corrected), with a radiochemical purity greater than 95%. The radiochemical yield was 10-15 times higher than that of 18F-DCFPyL, the probe currently used in clinical studies. All 4 compounds showed high affinity for PSMA. 18F-8a and 18F-10a had a particularly high binding affinity (Ki values of 3.35 and 2.23 nM, respectively). In the biodistribution study, the accumulation of 18F-8a (13.3 ± 2.2 percentage injected dose per gram [%ID/g]) and 18F-10a (14.0 ± 3.1 %ID/g) in PSMA-positive human prostate (LNCaP) tumors was higher than that of the other 2 compounds and similar to that of 18F-DCFPyL (16.0 ± 2.9 %ID/g). 18F-10a showed the lowest hepatic and intestinal accumulation among the 4 compounds and slightly slower blood clearance than others. In the PET imaging studies, 18F-8a and 18F-10a were clearly visualized in LNCaP in xenograft-bearing mice. 18F-10a showed higher LNCaP-to-liver ratios than 18F-8a. We confirmed the safety profiles of 18F-10a; the no-observed-adverse-effects level was larger than 13.2 µg/kg. CONCLUSION: A novel 18F-labeled asymmetric urea compound, 18F-10a, had a high radiochemical yield, high binding affinity for PSMA, and pharmacokinetic profiles suitable for a PSMA imaging probe. We believe that 18F-10a can be effectively and safely used in this type of imaging.

A case of uterine torsion concurrent with a ruptured ovarian endometrial cyst.

The patient was a 54-year-old female presented with severe abdominal swelling and intermittent pain. On emergent CT, massive ascites with thickened peritoneum and intra-pelvic cystic mass approximately 20 cm in diameter were observed. The cyst wall showed redundant irregular shape. The uterus was enlarged with intramural mass located at its right anterior fundus. MRI showed this pelvic cyst as high intensity on T1-weighted images, so that it was suspected as an endometrial cyst. The operation revealed the rupture of endometrial cyst and the uterine torsion of 180° around the long axis. Retrospectively, the X-shaped configuration of the upper vagina was observed on MRI and both the adnexa, including right ovarian cyst, were connected to the opposite side ovarian vein. Torsion of a non-gravid uterus is rare. In this case, the uterine torsion seemed to be caused by enlarged uterine body and ruptured endometrial cyst. Radiologists should be aware of this potential complication of huge ovarian mass and enlarged uterus and its appearance.

Development of (99m)Tc-labeled asymmetric urea derivatives that target prostate-specific membrane antigen for single-photon emission computed tomography imaging.

Prostate-specific membrane antigen (PSMA) is expressed strongly in prostate cancers and is, therefore, an attractive diagnostic and radioimmunotherapeutic target. In contrast to previous reports of PMSA-targeting (99m)Tc-tricarbonyl complexes that are cationic or lack a charge, no anionic (99m)Tc-tricarbonyl complexes have been reported. Notably, the hydrophilicity conferred by both cationic and anionic charges leads to rapid hepatobiliary clearance, whereas an anionic charge might better enhance renal clearance relative to a cationic charge. Therefore, an improvement in rapid clearance would be expected with either cationic or anionic charges, particularly anionic charges. In this study, we designed and synthesized a novel anionic (99m)Tc-tricarbonyl complex ([(99m)Tc]TMCE) and evaluated its use as a single-photon emission computed tomography (SPECT) imaging probe for PSMA detection. Direct synthesis of [(99m)Tc]TMCE from dimethyl iminodiacetate, which contains both the asymmetric urea and succinimidyl moiety important for PSMA binding, was performed using our microwave-assisted one-pot procedure. The chelate formation was successfully achieved even though the precursor included a complicated bioactive moiety. The radiochemical yield of [(99m)Tc]TMCE was 12-17%, with a radiochemical purity greater than 98% after HPLC purification. [(99m)Tc]TMCE showed high affinity in vitro, with high accumulation in LNCaP tumors and low hepatic retention in biodistribution and SPECT/CT studies. These findings warrant further evaluation of [(99m)Tc]TMCE as an imaging agent and support the benefit of this strategy for the design of other PSMA imaging probes.

DS-8201a, A Novel HER2-Targeting ADC with a Novel DNA Topoisomerase I Inhibitor, Demonstrates a Promising Antitumor Efficacy with Differentiation from T-DM1.

PURPOSE: An anti-HER2 antibody-drug conjugate with a novel topoisomerase I inhibitor, DS-8201a, was generated as a new antitumor drug candidate, and its preclinical pharmacologic profile was assessed. EXPERIMENTAL DESIGN: In vitro and in vivo pharmacologic activities of DS-8201a were evaluated and compared with T-DM1 in several HER2-positive cell lines and patient-derived xenograft (PDX) models. The mechanism of action for the efficacy was also evaluated. Pharmacokinetics in cynomolgus monkeys and the safety profiles in rats and cynomolgus monkeys were assessed. RESULTS: DS-8201a exhibited a HER2 expression-dependent cell growth-inhibitory activity and induced tumor regression with a single dosing at more than 1 mg/kg in a HER2-positive gastric cancer NCI-N87 model. Binding activity to HER2 and ADCC activity of DS-8201a were comparable with unconjugated anti-HER2 antibody. DS-8201a also showed an inhibitory activity to Akt phosphorylation. DS-8201a induced phosphorylation of Chk1 and Histone H2A.X, the markers of DNA damage. Pharmacokinetics and safety profiles of DS-8201a were favorable and the highest non-severely toxic dose was 30 mg/kg in cynomolgus monkeys, supporting DS-8201a as being well tolerated in humans. DS-8201a was effective in a T-DM1-insensitive PDX model with high HER2 expression. DS-8201a, but not T-DM1, demonstrated antitumor efficacy against several breast cancer PDX models with low HER2 expression. CONCLUSIONS: DS-8201a exhibited a potent antitumor activity in a broad selection of HER2-positive models and favorable pharmacokinetics and safety profiles. The results demonstrate that DS-8201a will be a valuable therapy with a great potential to respond to T-DM1-insensitive HER2-positive cancers and low HER2-expressing cancers. Clin Cancer Res; 22(20); 5097-108. ©2016 AACR.

Concurrent Malignant Solitary Fibrous Tumor Arising from the Omentum and Grade 3 Endometrial Endometrioid Adenocarcinoma of the Uterus with p53 Immunoreactivity.

A malignant solitary fibrous tumor arising from the omentum is extremely rare. To our knowledge, this is the first case of a malignant solitary fibrous omentum tumor coexisting with uterine corpus cancer. A 62-year-old woman presented to our hospital with vaginal discharge. Endometrioid adenocarcinoma was diagnosed by endometrial curettage. In addition, a solid tumor in front of the uterus was detected following computed tomography and/or magnetic resonance imaging, which was suspected to be a primary (or secondary) malignant tumor arising from the omentum. Hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and lymphadenectomy were performed. A malignant solitary fibrous tumor of the omentum and grade 3 endometrioid adenocarcinoma of the uterus were diagnosed by pathohistological analysis. Interestingly, the tumor cells were immunoreactive for p53. Adjuvant chemotherapy was administered for the uterine corpus cancer and the patient remains healthy 48 months after the surgery. These tumors may have become malignant due to the presence of p53 mutations.

Enhancement of binding affinity for amyloid aggregates by multivalent interactions of 99mTc-hydroxamamide complexes.

Deposition of amyloid aggregates has been regarded as an early stage of amyloidosis progression. An imaging probe that can image amyloid aggregates enables the early diagnosis of amyloidosis and contributes to the development of new medical therapies. High binding affinity for amyloid aggregates is essential to develop a useful molecular imaging probe. This article describes a new strategy to enhance the binding affinity of imaging agents targeting amyloid aggregates. We designed and synthesized novel (99m)Tc-hydroxamamide ((99m)Tc-Ham) complexes with a bivalent amyloid ligand and evaluated their binding affinity for amyloid aggregates by using ß-amyloid peptide (Aß(1-42)) aggregates as a model. In vitro inhibition assay indicated that bivalent (99m)Tc-Ham complexes had much higher binding affinity for amyloid aggregates than monovalent complexes. In vitro autoradiography using Tg2576 mice showed the specific binding of bivalent (99m)Tc-Ham complexes to Aß plaques in the mouse brain, as reflected in the results of the inhibition assay. The preliminary results suggest that a new molecular design based on bivalent (99m)Tc-Ham complexes may be reasonable to develop an imaging probe targeting amyloid aggregates.

Preparation of asymmetric urea derivatives that target prostate-specific membrane antigen for SPECT imaging.

Prostate-specific membrane antigen (PSMA) has been identified as a diagnostic and therapeutic target for prostate cancer. (S)-2-[3-[(R)-1-Carboxy-2-mercaptoethyl]ureido-pentanedioic acid (Cys-CO-Glu) were used to design novel PSMA targeting probes by nucleophilic conjugate addition between cysteine and maleimide based reagents. 3 ([(123)I]IGLCE) was synthesized by this strategy and showed high affinity for PSMA. Results of binding inhibition assays of these derivatives suggested the importance of an aromatic group and succinimide moiety for high affinity. [(123)I]3 was evaluated in vivo with PSMA positive LNCaP and PSMA negative PC-3 human prostate cancer xenograft bearing mice. [(125)I]3 accumulated in LNCaP tumors but not in PC-3 tumors, and the accumulation was inhibited by 2-(phosphonomethyl)pentanedioic acid (2-PMPA). Use of [(123)I]3 provided positive images of LNCaP tumors in single photon emission tomography scans. These results warrant further evaluation of [(123)I]3 and its derivatives as radiolabeled probes for the diagnosis of prostate cancer.

Microwave-assisted synthesis of organometallic complexes of 99mTc(CO)3 and Re(CO)3: its application to radiopharmaceuticals.

(99m)Tc-tricarbonyl [(99m)Tc(CO)(3)] complexes have been conventionally synthesized by heating [(99m)Tc(CO)(3)(H(2)O)(3)](+) and a tridentate chelating ligand under atmospheric pressure; however, this method is poor in terms of chemical yield and reproducibility. Moreover, since the half-life of (99m)Tc is very short (6 h), the development of facile and rapid methods of synthesizing (99m)Tc-labeled compounds, which could be used as radioactive tracers for single photon emission computed tomography (SPECT), is required. Thus, we initiated a study on the application of a microwave reaction to the synthesis of (99m)Tc(CO)(3)-2-picolylamine monoacetic acid (PAMA) [(99m)Tc(CO)(3)-PAMA] complexes on the basis of the fact that synthesis of metal complexes proceeds rapidly by microwave irradiation owing to an efficient exothermic phenomenon and heat conduction effect. Formation of by-products could be markedly suppressed by comparison with that in conventional methods. In the present study, rhenium (Re), an element belonging to the same group in the periodic table as technetium (Tc), and which also forms bipyramidal complexes, was first used to investigate the synthetic reaction because no stable isotopes exist for Tc. As a result, when water was used as the solvent under the irradiation of microwaves within 1 min, the Re(CO)(3)-PAMA complex could be directly synthesized from ethyl ester of PAMA (PAMAEE) and [Re(CO)(3)(H(2)O)(3)]Br in one step and with a high yield (94%). Finally, the (99m)Tc(CO)(3)-PAMA complex was successfully synthesized at a high radiochemical yield (>99%) within 1 min of reaction using (99m)Tc instead of Re under the same conditions.

A placental polyp arising from an exaggerated placental site.

There are very few reported cases of the clinical course of exaggerated placental site, and a case of a placental polyp arising from an exaggerated placental site has not been reported previously. Here, we report a case of a 43-year-old woman whose chief complaint was of massive genital bleeding. She had undergone an operation for induced abortion in the first trimester 41 days previously. A placental polyp measuring 45 mm with an abundant blood flow could be detected by transvaginal color Doppler ultrasonography and enhanced magnetic resonance imaging. We performed a transabdominal simple total hysterectomy. At the anterior wall of the uterus, a protruding lesion into the uterine cavity was observed and a placental polyp was attached to the protruding lesion. The histological specimen of the protruding lesion, which was considered to be the implantation site, showed intermediate trophoblastic cells infiltrated into the myometrium. An exaggerated placental site was diagnosed, which might lead to a placental polyp.

Maternal listeriosis in pregnancy associated with measles virus infection.

A case of maternal listeriosis associated with measles infection is described. Maternal listeriosis without fetal or neonatal involvement is relatively rare. This case was diagnosed early and treated appropriately, and the baby showed no symptoms or signs of feto-maternal infection.