Mechanistic insights into fungal mitochondrial outer membrane protein biogenesis.

The majority of mitochondrial proteins are nuclear-encoded and need to be transported into the mitochondria, including the proteins in the outer mitochondrial membrane. For ß-barrel proteins, the preproteins are initially recognized and imported by the TOM complex, then shuttled to the SAM complex via small Tim proteins. For ⍺-helical proteins, some preproteins are recognized by the TOM complex and imported into the membrane by the MIM complex. In recent years multiple structures of the TOM complex and the SAM complex have been reported, increasing our understanding of the mechanism of protein biogenesis in the outer mitochondrial membrane.

The Role of Voltage-Dependent Anion Channel in Mitochondrial Dysfunction and Human Disease.

The voltage-dependent anion channel (VDAC) is a ß-barrel membrane protein located in the outer mitochondrial membrane (OMM). VDAC has two conductance states: an open anion selective state, and a closed and slightly cation-selective state. VDAC conductance states play major roles in regulating permeability of ATP/ADP, regulation of calcium homeostasis, calcium flux within ER-mitochondria contact sites, and apoptotic signaling events. Three reported structures of VDAC provide information on the VDAC open state via X-ray crystallography and nuclear magnetic resonance (NMR). Together, these structures provide insight on how VDAC aids metabolite transport. The interaction partners of VDAC, together with the permeability of the pore, affect the molecular pathology of diseases including Parkinson's disease (PD), Friedreich's ataxia (FA), lupus, and cancer. To fully address the molecular role of VDAC in disease pathology, major questions must be answered on the structural conformers of VDAC. For example, further information is needed on the structure of the closed state, how binding partners or membrane potential could lead to the open/closed states, the function and mobility of the N-terminal α-helical domain of VDAC, and the physiological role of VDAC oligomers. This review covers our current understanding of the various states of VDAC, VDAC interaction partners, and the roles they play in mitochondrial regulation pertaining to human diseases.

Fluorodeoxyglucose positron-emission tomography-magnetic resonance hybrid imaging: An emerging tool for staging of cancer of the uterine cervix.

Positron-emission tomography-magnetic resonance imaging (PET-MRI) is an emerging hybrid imaging modality that utilizes the superior soft tissue resolution of MR with the metabolic data from PET. In this study, we sought to assess the clinical value of fluorodeoxyglucose (FDG) PET-MRI with dedicated pelvic PET-MR in the initial staging of cervical cancer. In this institutional-approved study, we identified 23 adult females who underwent FDG PET-MRI on hybrid camera for staging of primary uterine cervical cancer that included a dedicated PET-MR of the pelvis. A nuclear medicine physician and a radiologist reviewed the PET, MRI, and fusion-body and pelvis images alone and then with consensus read characterizing PET and MR abnormal findings. There were 23 patients who underwent FDG PET-MRI for initial staging of cervical cancer with an average age of 52.2 ± 14.0 years. A total of 23 suspected lymph nodes in eight different patients were detected within the pelvis with increased metabolic activity on PET. Both the dedicated pelvis and whole-body PET imaging detected the same corresponding pelvic lymph nodes, although the pelvic PET imaging had better lymph node uptake delineation due to longer acquisition time. Using a 10-mm short-axis criterion, MRI identified only 43.5% of the FDG avid lymph nodes. The average SUVmax on the pelvis PET sequences was higher with SUV 8.9 ± 5.2 compared to the whole-body PET with SUV 7.8 ± 5.4 but was not statistically significant (P > 0.05). Primary cervical cancer was identified in 18 patients on both PET imaging and MRI with dedicated MR pelvis providing better characterization. Based on our results of the patients with cervical cancer evaluated for initial staging, combining dedicated pelvic PET-MRI with whole-body PET/MR provides the most complete status of malignant disease in reference to delineation of primary tumor, involvement of surrounding tissues, and regional lymph nodes.

Accuracy in Referrals to Gynecologic Oncologists Based on Clinical Presentation for Ovarian Mass.

Ovarian cancer is one of the most lethal gynecological cancers in women due to late diagnosis. Despite technological advancements, experienced physicians have high sensitivities and specificities in subjective assessments when combining ultrasound findings and clinical history in analyzing adnexal masses. This study aims to demonstrate general obstetricians and gynecologists' (OB/GYN) appropriateness in gynecologic oncologist referrals for malignant ovarian masses based on history and physical (H&P), imaging, and available tumor markers. Three board certified OB/GYNs were given 148 cases and determined whether or not they would refer them to a gynecologic oncologist. Results showed that OB/GYNs were 81-85% accurate in diagnosing patients with a benign or malignant disease. Among the malignant cases, reviewers had a high sensitivity ranging from 74-81% in appropriately referring a malignancy. In our study, OB/GYNs referred between 23-32% of ovarian masses to a gynecologic oncologist with only 9.5% of cases found to be malignant. Despite the high referral rates, generalists showed a high degree of sensitivity in accurately referring malignant diseases based solely on clinical experience and imaging studies, which could improve survival rates with early intervention by gynecologic oncologists.

Uterine torsion with necrosis of bilateral adnexa in a postmenopausal woman.

Uterine torsion is an uncommon entity that is defined as a rotation of greater than 45° around the longitudinal axis of the uterus. Although cases of uterine torsion among pregnant patients have been mentioned in the literature, torsion of a non-gravid uterus is a rare occurrence. A 73-year-old nulliparous woman with a known fibroid uterus underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy with frozen section of a 17-18 cm pelvic mass seen on CT imaging. The source of the pelvic mass was unclear on imaging, and benign and malignant possibilities were discussed. During the procedure, necrosis of the uterine fundus and bilateral adnexa were seen due to the fundus being torsed with the uterine fibroid being the pivot point. Uterine torsion, though rare, can be the cause of acute pelvic pain in a postmenopausal woman.

Mechanisms of resistance to HER2-targeted therapies in HER2-amplified uterine serous carcinoma, and strategies to overcome it.

Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer that accounts for up to 40% of all endometrial cancer-related deaths. Recent whole-exome sequencing studies have revealed HER2/neu amplification in 27-44% of USC patients, supporting HER2 as an attractive pathway for target therapies based on monoclonal antibodies or tyrosine kinase inhibitors. Preclinical studies and a recently published prospective randomized trial with trastuzumab in combination with chemotherapy demonstrated promising results with anti-HER2-targeted therapies in advanced and recurrent USC patients. In contrast, single-agent trastuzumab or tyrosine kinase inhibitors (i.e., lapatinib) were unable to demonstrate significant clinical activity and/or durable tumor growth inhibition. Combinatorial therapies may represent novel, highly effective therapeutic strategies to overcome inborn or acquired resistance to HER2/neu-targeted therapies in HER2-amplified USC patients. This study presents a comprehensive review of the mechanisms of USC resistance to HER2-targeted therapies and potential strategies to overcome it.

Novel targeted therapies in ovarian and uterine carcinosarcomas.

Carcinosarcomas (CSs) of the uterus and ovary are rare biologically aggressive tumors with poor prognosis. The development of novel, effective treatment strategies against CSs of the female genital tract remains an unmet medical need. Whole-exome sequencing studies have recently demonstrated mutations or aberrant activation of multiple genes/pathways in CSs including HER2, PI3K/AKT/mTOR, EGFR, MAPK, genes related to histones and chromatin structure, and genes related to cell-cycle regulation. The carcinomatous component of these biphasic tumors is suggested to be the catalyst in CS tumorigenesis. This article reviews the genetic landscapes and explores novel targeted treatment modalities against this deadly gynecologic tumor.

Landscape of somatic single-nucleotide and copy-number mutations in uterine serous carcinoma.

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 NuRD-chromatin-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.

Syndrome of Inappropriate Antidiuretic Hormone after vinorelbine treatment.

BACKGROUND: Among oncologic patients, Syndrome of Inappropriate Antidiuretic Hormone is a common cause of hyponatremia, a prevalent electrolyte disorder. There are many causes for Syndrome of Inappropriate Antidiuretic Hormone, including chemotherapy medications. To date, only three cases associating vinorelbine and Syndrome of Inappropriate Antidiuretic Hormone have been published. CASE: A 47-year-old woman with stage IIIC serous ovarian adenocarcinoma developed life-threatening hyponatremia (124 mmol/L) after three cycles of vinorelbine. Assessment revealed Syndrome of Inappropriate Antidiuretic Hormone as the most likely culprit. Conservative managements including free fluid restriction normalized her sodium level and Syndrome of Inappropriate Antidiuretic Hormone resolved after vinorelbine discontinuation. CONCLUSION: Vinorelbine can cause Syndrome of Inappropriate Antidiuretic Hormone. It is important to monitor sodium concentration during vinorelbine treatment to avoid serious neurological complications of hyponatremia and to improve patient's quality of life.

HER2/neu as a potential target for immunotherapy in gynecologic carcinosarcomas.

Carcinosarcomas of the female genital tract are rare tumors with an aggressive clinical behavior. Trastuzumab, a humanized monoclonal antibody, acts by binding to HER2/neu extracellular domain and exhibits therapeutic efficacy in HER2/neu-overexpressing cancers. Two uterine carcinosarcomas (UMMT-ARK-1, UMMT-ARK-2) and 2 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, fluorescent in situ hybridization analysis, quantitative real-time polymerase chain reaction, and for membrane-bound complement regulatory proteins CD46, CD55, and CD59 by flow cytometry. Sensitivity to trastuzumab-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity was studied in 5-hr chromium release assays. HER2/neu expression was demonstrated in OMMT-ARK-1 and OMMT-ARK-2. OMMT-ARK-2 demonstrated an amplification of the c-erbB2 gene by fluorescent in situ hybridization analysis and a high sensitivity to ADCC (mean killing, 45.6%; range, 32.3%-72.6%). A lower level of killing was detected against the fluorescent in situ hybridization analysis-negative OMMT-ARK-1 cell line (mean, 26.5%; range, 21.0%-31.8%). CD46, CD55, and CD59 membrane-bound complement regulatory proteins were expressed at high levels in all primary mixed müllerian tumor cell lines, and all these tumors were found to be highly resistant to complement-dependent cytotoxicity 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 does 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.

A survey of gynecologic oncologists regarding the end-of-life discussion: a pilot study.

OBJECTIVES: To identify the practices and attitudes of gynecologic oncologists regarding the end-of-life discussion. METHODS: A pilot survey was sent to 1105 members of the Society of Gynecologic Oncologists (SGO). The survey consisted of 20 questions and was sent via the website Survey Monkey. RESULTS: Response rate was 12.8%. Sixty percent of respondents were male, most ranged between 30 and 60 years of age and more than half performed 5-10 major surgeries per week. More than half of respondents (53.9%) deferred the End of Life discussion until the patient had sustained a major change in functional and/or medical status. Thirty percent initiated it at the first recurrence or progression of disease. Forty three percent of respondents characterized the discussion as an on-going process. Patients' age, social support, health insurance, and co-morbidities had no influence on the discussion, and neither did the tumor's site of origin or grade. More respondents initiated the discussion in advanced stage cancer (57%) and after salvage chemotherapy institution (54%). Forty four percent of respondents reported that "understanding and acceptance" was the initial response by patient when counseled about withdrawal of care. This increased to 86% when the issue was revisited. Confusion or reluctance to discuss the subject were initially reported to be 12% and 19%, respectively, but decreased to 2% and 3%, respectively, when withdrawal of care was subsequently addressed with the patient. CONCLUSIONS: This pilot survey sheds a light on attitudes and practices about the end-of-life discussion that deserve to be further studied.

Clear cell cancer of the uterine corpus: the association of clinicopathologic parameters and treatment on disease progression.

This paper presents a single-institution experience regarding the clinicopathologic features and treatment strategies used in uterine clear cell cancer (UCC), a rare, aggressive histologic subtype of uterine cancer with poor prognosis and discusses parameters associated with progression-free survival (PFS) and overall survival (OS). A retrospective chart review was performed on all patients (n = 80) diagnosed with UCC and treated between 1994 and 2009 at a single academic institution. Data on demographics, FIGO stage, treatment regimens, and recurrences were collected. Patients with early-stage UCC had an excellent survival regardless of adjuvant therapy. Advanced-stage patients had a worse survival. Vaginal apex brachytherapy was associated with an increased OS (P = 0.02) but not PFS (P = 0.10). The use of platinum-based chemotherapy in combination with vaginal apex brachytherapy did not significantly improve survival. Innovative therapies still need to be identified for this uncommon uterine cancer.

Uterine and ovarian carcinosarcomas overexpressing Trop-2 are sensitive to hRS7, a humanized anti-Trop-2 antibody.

BACKGROUND: We evaluated the expression of human trophoblastic cell-surface marker (Trop-2) and the potential of hRS7 - a humanized monoclonal anti-Trop-2 antibody - as a therapeutic strategy against treatment-refractory human uterine (UMMT) and ovarian (OMMT) carcinosarcoma cell lines. MATERIALS AND METHODS: Trop-2 expression was evaluated by immunohistochemistry (IHC) in paraffin-embedded tumor tissues, by real-time polymerase-chain-reaction (RT-PCR) and flow-cytometry in cell lines. Sensitivity to hRS7 antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity was tested using 5-hour chromium-release assays against UMMT and OMMT cells. RESULTS: Trop-2 expression was elevated in 9 of 26 (35%) UMMT and 8 of 14 (57%) OMMT tissues tested by IHC. Positivity for Trop-2 mRNA by RT-PCR and surface expression by flow cytometry were detected in 2 of 4 cell lines, with high positivity noted in OMMT-ARK-2. OMMT-ARK-2 was highly sensitive to hRS7 ADCC (range: 34.7-41.0%; P < 0.001) with negligible cytotoxicity seen in the absence of hRS7 or in the presence of control antibody (range: 1.1-2.5%). Human IgG did not significantly inhibit ADCC while human complement increased, hRS7-mediated-cytotoxicity against OMMT-ARK-2. CONCLUSION: Trop-2 is overexpressed in a proportion of UMMT and OMMT, and hRS7 may represent a novel, potentially highly effective treatment option for patients with treatment-refractory carcinosarcomas overexpressing Trop-2.

Trop-2 overexpression in poorly differentiated endometrial endometrioid carcinoma: implications for immunotherapy with hRS7, a humanized anti-trop-2 monoclonal antibody.

OBJECTIVE: We evaluated the expression of human trophoblast cell surface marker (Trop-2) in endometrial endometrioid carcinoma (EEC) and the potential application of hRS7, a humanized monoclonal anti-Trop-2 antibody, as a therapeutic agent against poorly differentiated EEC. METHODS: Trop-2 expression was evaluated by immunohistochemistry in 131 EEC with different degrees of differentiation and 32 normal endometrial controls (NEC). Trop-2 expression was also evaluated by quantitative real-time polymerase chain reaction and flow cytometry in 3 primary EEC cell lines derived from patients harboring poorly differentiated EEC. Finally, the sensitivity of grade 3 EEC cell lines to hRS7 antibody-dependent cellular cytotoxicity was tested in standard 5-hour Cr release assays. RESULTS: Trop-2 expression was detected in 126 (96.2%) of 131 EEC samples. Tumor tissues showed markedly increased Trop-2 positivity compared with NEC (P = 0.001). Trop-2 expression was significantly higher in all grades of EEC versus NEC. Grade 3 tumors displayed significantly stronger Trop-2 immunostaining compared with grade 1 EEC (P = 0.01). High Trop-2 expression by quantitative real-time polymerase chain reaction and flow cytometry was found in 1 grade 3 EEC primary cell line (EEC-ARK-1). Unlike Trop-2-negative EEC cell lines, EEC-ARK-1 was found highly sensitive to hRS7-mediated antibody-dependent cellular cytotoxicity in vitro (range of killing, 33.9%-50.6%; P = 0.004). Human serum did not significantly inhibit hRS7-mediated cytotoxicity against EEC-ARK-1 (P = 0.773). CONCLUSIONS: Trop-2 is highly expressed in EEC, and its expression is significantly higher in poorly differentiated EEC when compared with well-differentiated EEC. Primary grade 3 EECs overexpressing Trop-2 are highly sensitive to hRS7-mediated cytotoxicity in vitro. hRS7 may represent a novel therapeutic agent for the treatment of high-grade EEC refractory to standard treatment modalities.

Cervical carcinomas overexpress human trophoblast cell-surface marker (Trop-2) and are highly sensitive to immunotherapy with hRS7, a humanized monoclonal anti-Trop-2 antibody.

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, against treatment-refractory cervical cancer. STUDY DESIGN: Trop-2 expression was evaluated by immunohistochemistry, real-time polymerase chain reaction, and flow cytometry. Sensitivity to hRS7 antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity was tested in 5-hour chromium release assays. The effect of interleukin (IL)-2 on hRS7 ADCC was also investigated. RESULTS: Membrane Trop-2 expression was observed in 8 of 8 (100%) of the cancer samples tested by immunohistochemistry, but not in normal cervix. High messenger RNA expression by real-time polymerase chain reaction and high Trop-2 surface expression by flow cytometry were detected in 80% of cervical cancers (4 of 5 cell lines). Although these tumors were resistant to natural killer cell-dependent cytotoxicity in vitro (mean killing, 6.0%), Trop-2-positive cell lines showed high sensitivity to hRS7 ADCC (range of killing, 30.6-73.2%). Incubation with IL-2 further increased the level of cytotoxicity against Trop-2-positive tumors. CONCLUSION: hRS7 may represent a novel treatment option for patients with cervical cancer refractory to conventional treatment modalities.

Tissue factor expression in ovarian cancer: implications for immunotherapy with hI-con1, a factor VII-IgGF(c) chimeric protein targeting tissue factor.

We evaluated the expression of tissue factor (TF) in ovarian cancer (EOC) and the potential of hI-con1, an antibody-like molecule targeting TF, as a novel form of therapy against chemotherapy-resistant ovarian disease. We studied the expression of TF in 88 EOC by immunohistochemistry (IHC) and real-time-PCR (qRT-PCR) and the levels of membrane-bound-complement-regulatory-proteins CD46, CD55 and CD59 in primary EOC cell lines by flow-cytometry. Sensitivity to hI-con1-dependent-cell-mediated-cytotoxicity (IDCC), complement-dependent-cell-cytotoxicity and inhibition of IDCC by γ-immunoglobulin were evaluated in 5-h (51)chromium-release-assays. Cytoplasmic and/or membrane TF expression was observed in 24 out of 25 (96%) of the EOC samples tested by IHC, but not in normal ovarian-tissue. EOC with clear cell histology significantly overexpress TF when compared to serous, endometrioid, or undifferentiated tumors by qRT-PCR. With a single exception, all primary EOC that overexpressed TF demonstrated high levels of CD46, CD55 and CD59 and regardless of their histology or resistance to chemotherapy, were highly sensitive to IDCC. The effect of complement and physiologic doses of γ-immunoglobulin on IDCC in ovarian cancer cell lines overexpressing TF was tumor specific and related to the overexpression of CD59 on tumor cells. Small-interfering-RNA-mediated knockdown of CD59 expression in ovarian tumors significantly increased hI-con1-mediated cytotoxic activity in vitro. Finally, low doses of interleukin-2 further increased the cytotoxic effect induced by hI-con1 (P < 0.01). hI-con1 molecule induces strong cytotoxicity against primary chemotherapy-resistant ovarian cancer cell lines overexpressing TF and may represent a novel therapeutic agent for the treatment of ovarian tumors refractory to standard treatment modalities.

Eradication of chemotherapy-resistant CD44+ human ovarian cancer stem cells in mice by intraperitoneal administration of Clostridium perfringens enterotoxin.

BACKGROUND: Emerging evidence has suggested that the capability to sustain tumor formation, growth, and chemotherapy resistance in ovarian as well as other human malignancies exclusively resides in a small proportion of tumor cells termed cancer stem cells. During the characterization of CD44(+) ovarian cancer stem cells, we found a high expression of the genes encoding for claudin-4. Because this tight junction protein is the natural high-affinity receptor for Clostridium perfringens enterotoxin (CPE), we have extensively investigated the sensitivity of ovarian cancer stem cells to CPE treatment in vitro and in vivo. METHODS: Real-time polymerase chain reaction and flow cytometry were used to evaluate claudin-3/-4 expression in ovarian cancer stem cells. Small interfering RNA knockdown experiments and MTS assays were used to evaluate CPE-induced cytotoxicity against ovarian cancer stem cell lines in vitro. C.B-17/SCID mice harboring ovarian cancer stem cell xenografts were used to evaluate CPE therapeutic activity in vivo. RESULTS: CD44(+) ovarian cancer stem cells expressed claudin-4 gene at significantly higher levels than matched autologous CD44(-) ovarian cancer cells, and regardless of their higher resistance to chemotherapeutic agents died within 1 hour after exposure to 1.0 µg/mL of CPE in vitro. Conversely, small-interfering RNA-mediated knockdown of claudin-3/-4 expression in CD44(+) cancer stem cells significantly protected cancer stem cells from CPE-induced cytotoxicity. Importantly, multiple intraperitoneal administrations of sublethal doses of CPE in mice harboring xenografts of chemotherapy-resistant CD44(+) ovarian cancer stem cells had a significant inhibitory effect on tumor progression leading to the cure and/or long-term survival of all treated animals (ie, 100% reduction in tumor burden in 50% of treated mice; P < .0001). CONCLUSIONS: CPE may represent an unconventional, potentially highly effective strategy to eradicate chemotherapy-resistant cancer stem cells.

Expression of αV-integrins in uterine serous papillary carcinomas; implications for targeted therapy with intetumumab (CNTO 95), a fully human antagonist anti-αV-integrin antibody.

OBJECTIVE: Uterine serous papillary carcinoma (USPC) is an aggressive variant of endometrial cancer characterized by an innate resistance to chemotherapy and poor prognosis. In this study, we evaluated the expression of αV-integrins in primary USPC cell lines and the in vitro ability of intetumumab (CNTO 95), a fully human monoclonal antibody against αV-integrins, to inhibit USPC cell adhesion and migration. MATERIALS AND METHODS: The surface expression of integrins belonging to the αV-family, including αVß3, αVß5, and αVß6, was evaluated in 6 primary USPC cell lines using flow cytometry analysis. To test the ability of intetumumab to inhibit USPC cell adhesion and migration, adhesion assays in the presence of vitronectin and migration assays through an 8.0-µm pore polycarbonate membrane also were performed. RESULTS: We found high expression of the αV-subunit on the cell surface of all 6 primary USPC cell lines tested (100% positive cells; mean fluorescence intensity range, 13.1-39.5). When the expression of single heterodimeric integrins was evaluated, αVß3, αVß5, and αVß6 were expressed on 37.5%, 32.0%, and 16.3% of cells (mean fluorescence intensity range, 6.5-16.2, 9.2-32.5, and 6.2-11.5, respectively). Importantly, in functional assays, low doses of intetumumab were effective in inhibiting adhesion (0.15 µg/mL, P = 0.003) and migration (1.25 µg/mL P = 0.02) of primary USPC cell lines. CONCLUSIONS: The αV-integrins are overexpressed on the cell surface of primary USPC cell lines. Intetumumab may significantly inhibit USPC cell adhesion and migration pathways and may therefore represent a novel treatment option for patients harboring this rare but highly aggressive variant of endometrial cancer.

Expression of tissue factor in adenocarcinoma and squamous cell carcinoma of the uterine cervix: implications for immunotherapy with hI-con1, a factor VII-IgGFc chimeric protein targeting tissue factor.

BACKGROUND: Cervical cancer continues to be an important worldwide health problem for women. Up to 35% of patients who are diagnosed with and appropriately treated for cervical cancer will recur and treatment results are poor for recurrent disease. Given these sobering statistics, development of novel therapies for cervical cancer remains a high priority. We evaluated the expression of Tissue Factor (TF) in cervical cancer and the potential of hI-con1, an antibody-like-molecule targeted against TF, as a novel form of immunotherapy against multiple primary cervical carcinoma cell lines with squamous- and adenocarcinoma histology. METHODS: Because TF is a transmembrane receptor for coagulation factor VII/VIIa (fVII), in this study we evaluated the in vitro expression of TF in cervical carcinoma cell lines by immunohistochemistry (IHC), real time-PCR (qRT-PCR) and flow cytometry. Sensitivity to hI-con1-dependent cell-mediated-cytotoxicity (IDCC) was evaluated in 5-hrs-51chromium-release-assays against cervical cancer cell lines in vitro. RESULTS: Cytoplasmic and/or membrane TF expression was observed in 8 out of 8 (100%) of the tumor tissues tested by IHC and in 100% (11 out of 11) of the cervical carcinoma cell lines tested by real-time-PCR and flow cytometry but not in normal cervical keratinocytes (p=0.0023 qRT-PCR; p=0.0042 flow cytometry). All primary cervical cancer cell lines tested overexpressing TF, regardless of their histology, were highly sensitive to IDCC (mean killing±SD, 56.2%±15.9%, range, 32.4%-76.9%, p<0.001), while negligible cytotoxicity was seen in the absence of hI-con1 or in the presence of rituximab-control-antibody. Low doses of interleukin-2 further increased the cytotoxic effect induced by hI-con1 (p=0.025) while human serum did not significantly decrease IDCC against cervical cancer cell lines (p=0.597). CONCLUSIONS: TF is highly expressed in squamous and adenocarcinoma of the uterine cervix. hI-con1 induces strong cytotoxicity against primary cervical cancer cell lines overexpressing TF and may represent a novel therapeutic agent for the treatment of cervical cancer refractory to standard treatment modalities.