Management of recurrent epithelial ovarian carcinoma

Despite the standardisation of surgical techniques and significant progress in chemotherapeutics over the last 30 years, advanced epithelial ovarian cancer remains the most lethal gynaecological malignancy in the western world. Although the majority of women achieve a remission following primary therapy, most patients with advanced stage disease will eventually relapse and become candidates for 'salvage' therapy. The chances of a further remission depend on factors such as the 'treatment-free interval', and there are now a large number of chemotherapy agents with activity in ovarian cancer available to the oncologist. Recent randomised studies have reported on survival benefits for chemotherapy in recurrent disease, and therefore careful and appropriate selection of treatments has assumed a greater importance. This article reviews the most current data, and discusses the factors involved in making individualised treatment decisions.

Efficacy of Lentivirus-mediated and MUC1 antibody-targeted VP22-TK/GCV suicide gene therapy for ovarian cancer

Transfer of the herpes simplex virus type I thymidine kinase (HSV-TK) gene into tumor cells using virus-based vectors in conjunction with ganciclovir (GCV) exposure provides a potential gene therapy strategy for the treatment of cancer. Effective gene therapy,, depends on the efficient transfer and specific targeting of therapeutic genes and their protein products to target cells. The purpose of this study was to investigate the anti-tumor effect of Lentivirus-mediated and MUC1 antibody-targeted VP22-TK/GCV suicide gene therapy in animal models. Mouse models were generated with intraperitoneal injection of human epithelial ovarian cancer cells 3AO, which are MUC1-positive. HTV-1-based lentiviral vectors carrying VP22-TK or scFv-VP22-TK were prepared. The animals were injected intraperitoneally with lentivirus containing scFv-VP22-TK, VP22-TK followed by GCV treatment. Combined treatment of lentivirus-expressed scFv-VP22-TK or VP22-TK with GCV inhibited the proliferation and prolonged survival times compared with the control vector. The survival time of animals treated with scFv-VP22-TK/GCV was significantly longer than that of animals treated with VP22-TK/GCV (p = 0.006). Conclusion: Our results suggest that MUC1 antibody-targeted VP22-TK/GCV suicide gene therapy can efficiently inhibit ovarian tumor growth and increase survival in a nude mouse model of ovarian carcinoma. These data support the development of this method for human clinical trials.

Radioimunoterapia: uma abordagem terapêutica promissora no tratamento do carcinoma do ovário

O cancro do ovário é a neoplasia ginecológica com maior índice de mortalidade entre a população do sexo feminino apesar dos consideráveis progressos verificados no seu tratamento. Caso o diagnóstico seja precoce, a taxa de sobrevida é bastante elevada, mas o cancro do ovário primário é assintomático e na maioria das vezes só é diagnosticado numa fase avançada da doença, resultando num prognóstico pouco favorável. A falta de especificidade das modalidades terapêuticas associada à heterogeneidade das células oncológicas tem limitado a terapia do cancro do ovário. Alguns dos avanços clínicos mais promissores no tratamento do cancro são as terapêuticas dirigidas a alvos específicos, especialmente proteínas sobre expressas em vários tipos de células epiteliais. Neste contexto, a radioimunoterapia com anticorpos monoclonais tem sido explorada nos carcinomas epiteliais que constituem cerca de 90% das neoplasias do ovário. Esta estratégia terapêutica, que tira partido da ação combinada da radiotoxicidade associada aos radionuclídeos para terapia e dos efeitos citotóxicos do anticorpo, pode constituir uma alternativa às terapias convencionais, potenciando a eficácia do tratamento. Neste artigo são abordados aspetos relacionados com o cancro do ovário, nomeadamente o seu diagnóstico e terapia. São ainda revistos, de forma breve, alguns estudos clínicos em que a eficácia de anticorpos monoclonais marcados com radionuclídeos para terapêutica foi avaliada no cancro do ovário.

TRAIL-R3-related apoptosis: Epigenetic and expression analyses in women with ovarian neoplasia

Objective. To assess the expression of TRAIL-R3 and the methylation of a CpG island within the TRAIL-R3 promoter both in cystadenoma tumors and primary and metastatic epithelial ovarian carcinoma (EOC).Methods. RNA was obtained from women with normal ovarian (NO) tissues (n = 18), ovarian serous cystadenoma tumors (n = 11) and EOC (n = 16) using Trizol (R). Quantitative PCR (gRT-PCR) was performed to quantify the relative levels of TRAIL-R3. The methylation frequency of the CpG island in the TRAIL-R3 promoter was assessed using the methylation-specific PCR (MSP) assay after DNA bisulfite conversion. The differences between the groups were evaluated using the chi-square, Student's t, ANOVA, Mann-Whitney U, Wilcoxon or Kruskal-Wallis tests as indicated. The survival rates were calculated using the Kaplan-Meier method.Results. Cystadenoma and metastatic EOC tumors expressed significantly more TRAIL-R3 mRNA than primary EOC tumors. Methylation of the TRAIL-R3 promoter was absent in NO tissues, while hemimethylation of the TRAIL-R3 promoter was frequently found in the neoplasia samples with 45.4% of the cystadenoma tumors, 8.3% of the primary EOC samples and 11.1% of the metastatic EOC samples showing at least partial methylation (p = 0.018). Neither the expression of TRAIL-R3 nor alterations in the methylation profile were associated to cumulative progression-free survival or the overall survival in EOC patients.Conclusions. Primary EOC is associated to a lower TRAIL-R3 expression, which leads to a better understanding of the complex disease and highlighting potential therapeutic targets. Promoter DNA methylation was not related to this finding, suggesting the presence of other mechanisms to transcriptional control. (C) 2012 Elsevier B.V. All rights reserved.

The Role of Acidic Fibroblast Growth Factor and Fibroblast Growth Factor Receptor 4 in High Grade Serous Carcinoma

Background: High grade serous carcinoma whether ovarian, tubal or primary peritoneal, continues to be the most lethal gynecologic malignancy in the USA. Although combination chemotherapy and aggressive surgical resection has improved survival in the past decade the majority of patients still succumb to chemo-resistant disease recurrence. It has recently been reported that amplification of 5q31-5q35.3 is associated with poor prognosis in patients with high grade serous ovarian carcinoma. Although the amplicon contains over 50 genes, it is notable for the presence of several members of the fibroblast growth factor signaling axis. In particular acidic fibroblast growth factor (FGF1) has been demonstrated to be one of the driving genes in mediating the observed prognostic effect of the amplicon in ovarian cancer patients. This study seeks to further validate the prognostic value of fibroblast growth receptor 4 (FGFR4), another candidate gene of the FGF/FGFR axis located in the same amplicon. The emphasis will be delineating the role the FGF1/FGFR4 signaling axis plays in high grade serous ovarian carcinoma; and test the feasibility of targeting the FGF1/FGFR4 axis therapeutically. Materials and Methods: Spearman and Pearson correlation studies on data generated from array CGH and transcriptome profiling analyses on 51 microdissected tumor samples were used to identify genes located on chromosome 5q31-35.3 that showed significant correlation between DNA and mRNA copy numbers. Significant correlation between FGF1 and FGFR4 DNA copy numbers was further validated by qPCR analysis on DNA isolated from 51 microdissected tumor samples. Immunolocalization and quantification of FGFR4 expression were performed on paraffin embedded tissue samples from 183 cases of high-grade serous ovarian carcinoma. The expression was then correlated with clinical data to assess impact on survival. The expression of FGF1 and FGFR4 in vitro was quantified by real-time PCR and western blotting in six high-grade serous ovarian carcinoma cell lines and compared to those in human ovarian surface epithelial cells to identify overexpression. The effect of FGF1 on these cell lines after serum starvation was quantified for in vitro cellular proliferation, migration/invasion, chemoresistance and survival utilizing a combination of commercially available colorimetric, fluorometric and electrical impedance assays. FGFR4 expression was then transiently silenced via siRNA transfection and the effects on response to FGF1, cellular proliferation, and migration were quantified. To identify relevant cellular pathways involved, responsive cell lines were transduced with different transcription response elements using the Cignal-Lenti reporter system and treated with FGF1 with and without transient FGFR4 knock down. This was followed by western blot confirmation for the relevant phosphoproteins. Anti-FGF1 antibodies and FGFR trap proteins were used to attempt inhibition of FGF mediated phenotypic changes and relevant signaling in vitro. Orthotopic intraperitoneal tumors were established in nude mice using serous cell lines that have been previously transfected with luciferase expressing constructs. The mice were then treated with FGFR trap protein. Tumor progression was then followed via bioluminescent imaging. The FGFR4 gene from 52 clinical samples was sequenced to screen for mutations. Results: FGFR4 DNA and mRNA copy numbers were significantly correlated and FGFR4 DNA copy number was significantly correlated with that of FGF1. Survival of patients with high FGFR4 expressing tumors was significantly shorter that those with low expression(median survival 28 vs 55 month p< 0.001) In a multivariate cox regression model FGFR expression significantly increased risk of death (HR 2.1, p<0.001). FGFR4 expression was significantly higher in all cell lines tested compared to HOSE, OVCA432 cell line in particular had very high expression suggesting amplification. FGF1 was also particularly overexpressed in OVCA432. FGF1 significantly increased cell survival after serum deprivation in all cell lines. Transient knock down of FGFR4 caused significant reduction in cell migration and proliferation in vitro and significantly decreased the proliferative effects of FGF1 in vitro. FGFR1, FGFR4 traps and anti-FGF1 antibodies did not show activity in vitro. OVCA432 transfected with the cignal lenti reporter system revealed significant activation of MAPK, NFkB and WNT pathways, western blotting confirmed the results. Reverse phase protein array (RPPA) analysis also showed activation of MAPK, AKT, WNT pathways and down regulation of E Cadherin. FGFR trap protein significantly reduced tumor growth in vivo in an orthotopic mouse model. Conclusions: Overexpression and amplification of several members of the FGF signaling axis present on the amplicon 5q31-35.3 is a negative prognostic indicator in high grade serous ovarian carcinoma and may drive poor survival associated with that amplicon. Activation of The FGF signaling pathway leads to downstream activation of MAPK, AKT, WNT and NFkB pathways leading to a more aggressive cancer phenotype with increased tumor growth, evasion of apoptosis and increased migration and invasion. Inhibition of FGF pathway in vivo via FGFR trap protein leads to significantly decreased tumor growth in an orthotopic mouse model.

Ovarian cancer angiogenesis, biology and therapy

The progressive growth of epithelial ovarian cancer tumor is regulated by proangiogenic molecules and growth factors released by tumor cells and the microenvironment. Previous studies showed that the expression of interleukin-8 (IL-8) directly correlates with the progression of human ovarian carcinomas implanted into the peritoneal cavity of nude mice. We examined the expression level of IL-8 in archival specimens of primary human ovarian carcinoma from patients undergoing curative surgery by in situ mRNA hybridization technique. The expression of IL-8 was significantly higher in patients with stage III disease than in patients with stage I disease. To investigate the role of IL-8 in the progressive growth of ovarian cancer, we isolated high- and low-IL-8 producing clones from parental Hey-A8 human ovarian cancer cells, and compared their proliferative activity and tumorigenicity in nude mice. The effect of exogenous IL-8 and IL-8 neutralizing antibody on ovarian cancer cell proliferation was investigated. Finally, we studied the modulation of IL-8 expression in ovarian cancer cells by sense and antisense IL-8 expression vector transfection and its effect on proliferation and tumorigenicity. We concluded that IL-8 has a direct growth potentiating activity in human ovarian cancer cells. ^ The expression level of IL-8 directly correlates with disease progression of human ovarian cancer, but the mechanism of induction is unknown. Since hypoxia and acidic pH are common features in solid tumors, we determined whether hypoxic and acidic conditions could regulate the expression of IL-8. Culturing the human ovarian cancer cells in hypoxic or acidic medium led to a significant increase in IL-8 mRNA and protein. Hypoxic- and acidosis-mediated transient increase in IL-8 expression involved both transcriptional activation of the IL-8 gene and enhanced stability of the IL-8 mRNA. Furthermore, we showed that IL-8 transcription activation by hypoxia or acidosis required the cooperation of NF-κB and AP-1 binding sites. ^ Finally, we studied novel therapies against human ovarian cancer. First, we determined whether inhibition of the catalytic tyrosine kinase activity of the receptors for vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) inhibits the formation of malignant ascites and the progressive growth of human ovarian carcinoma cells implanted into the peritoneal cavity of nude mice. Our results suggest that blockade of the VEGF/VPF receptor may be an efficient strategy to inhibit formation of malignant ascites and growth of VEGF/VPF-dependent human ovarian carcinomas. Secondly, we determined whether local sustained production of murine interferon-β could inhibit the growth of human ovarian cancer cells in the peritoneal cavity of nude mice. Our results showed that local production of IFN-β could inhibit the in vivo growth of human ovarian cancer cells by upregulating the expression of the inducible nitric oxide synthase (NOS) in host macrophages. ^

Estrogen-induced gene expression and patient survival in high-grade serous carcinoma of the ovary

Background. Assessment of estrogen receptor (ER) expression has inconsistent utility as a prognostic marker in epithelial ovarian carcinoma. In breast and endometrial cancers, the use of estrogen-induced gene panels, rather than ER expression alone, has shown improved prognostic capability. Specifically, over-expression of estrogen-induced genes in these tumors is associated with a better prognosis and signifies estrogen sensitivity that can be exploited with hormone antagonizing agents. It was therefore hypothesized that estrogen-induced gene expression in ovarian carcinoma would successfully predict outcomes and differentiate between tumors of varying estrogen sensitivities. Methods. Two hundred nineteen (219) patients with ovarian cancer who underwent surgery at M. D. Anderson between 2004 and 2007 were identified. Of these, eighty-three (83) patients were selected for inclusion because they had advanced stage, high-grade serous carcinoma of the ovary or peritoneum, had not received neoadjuvant chemotherapy, and had readily available frozen tissue for study. All patients had also received adjuvant treatment with platinum and taxane agents. The expression of seven genes known to be induced by estrogen in the female reproductive tract (EIG121, sFRP1, sFRP4, RALDH2, PR, IGF-1, and ER) was measured using qRT-PCR. Unsupervised cluster analyses of multiple gene permutations were used to categorize patients as high or low estrogen-induced gene expressors. QPCR gene expression results were then compared to ER and PR immunohistochemical (IHC) expression. Cox proportional hazards models were used to evaluate the effects of both individual genes and selected gene clusters on patient survival. Results. Median follow-up time was 38.7 months (range 1-68 months). In a multivariate model, overall survival was predicted by sFRP1 expression (HR 1.10 [1.02-1.19], p=0.01) and EIG121 expression (HR 1.28 [1.10-1.49], p<0.01). A cluster defined by EIG121 and ER was further examined because that combination appeared to reasonably segregate tumors into distinct groups of high and low estrogen-induced gene expressors. Shorter overall survival was associated with high estrogen-induced gene expressors (HR 2.84 [1.11-7.30], p=0.03), even after adjustment for race, age, body mass index, and residual disease at debulking. No difference in IHC ER or PR expression was noted between gene clusters. Conclusion. In sharp contrast to breast and endometrial cancers, high estrogen-induced gene expression predicts shorter overall survival in patients with high-grade serous ovarian carcinoma. An estrogen-induced gene biomarker panel may have utility as prognostic indicator and may be useful to guide management with estrogen antagonists in this population.^

The effects of IL -10 producing monocytes on T-cell activation in patients with epithelial ovarian cancer

A newly described subset of monocytes has been identified in peritoneal exudate cells (PEC) from the malignant ascites of patients with ovarian cancer. These cells were characterized by the production of IL-10 and TGF-β2, but not IL-12, IL-1α, or TNF-α, and expressed CD14, CD16, and CD54, but not HLA-DR, CD80, CD86, CD11a, CD11b, or CD25 cell surface antigens. Since this subset of monocytes could affect the modulation of tumor immune responses in vivo, studies were undertaken to determine their effect on the activation and proliferation of autologous T-cells from the peritoneal cavity of patients with ovarian carcinoma. Cytokine transcripts, including IL-2, GM-CSF, and IFN-γ were detected in T-cells isolated from patient specimens that also contained the IL-10 producing monocytes, although the IFN-γ and IL-2 proteins could not be detected in T-cells co-incubated with the IL-10 producing monocytes in vitro. Additionally, IL-10 producing monocytes co-cultured with autologous T-cells inhibited the proliferation of the T-cells in response to PHA. T-cell proliferation and cytokine protein production could be restored by the addition of neutralizing antibodies to IL-10R and TGF-β to the co-culture system. These results suggested that this subset of monocytes may modulate antitumor immune responses by inhibiting T-cell proliferation and cytokine protein production. Further studies determined that the precursors to the inhibitory monocytes were tumor-associated and only present in the peripheral blood of patients with ovarian cancer and not present in the peripheral blood of healthy donors. These precursors could be induced to the suppressor phenotype by the addition of IL-2 and GM-CSF, two cytokines detected in the peritoneal cavity of ovarian cancer patients. Lastly, it was shown that the suppressor monocytes from the peritoneal cavity of ovarian cancer patients could be differentiated to a non-inhibitory phenotype by the addition of TNF-α and IFN-γ to the culture system. The differentiated monocytes did not produce IL-10, expressed the activation antigens HLA-DR, CD80, and CD86, and were able to stimulate autologous T-cells in vitro. Since a concomitant reduction in immune function is associated with tumor growth and progression, the effects of these monocytes are of considerable importance in the context of tumor immunotherapy. ^

Epithelial Ovarian Cancers and Endometriosis

Aims: To determine the prevalence of endometriosis in epithelial ovarian cancers (EOC) and the association among their histological subtypes and with endometrial carcinoma. Methods: An observational cohort study performed in 192 patients operated on for EOC, 30 women with atypical endometriosis and 17 with p53 positive endometriosis. Data on associated endometriosis and endometrial carcinomas, histological subtypes, tumor stage, clinical and pathological characteristics and survival were analyzed. Results: Twenty cases of EOC (10.4%) had also endometriosis (12.7 in borderline and 9.3% in invasive cases), being a synchronous finding in most cases. Endometriosis associated with serous or mucinous EOC was observed in 2.2 and 2.7% of cases, respectively. However, this association was observed in 50 of endometrioid and 23% of clear cell EOC. Age, parity and tumor stage were lower in endometriosis-associated EOC patients; and all associated cases were type I (Kurman and Shih's classification) and showed better results in survival rate. Endometrial carcinoma was more frequently associated with endometrioid EOC (25%). Conclusions: There is a significant association between endometriosis, including atypical forms, and endometrioid and clear cell carcinomas, but not with other EOC histotypes. The presence of endometriosis in EOC suggests a better prognosis and an intermediate stage within the progression endometriosis-carcinoma.

A case of extraovarian primary peritoneal carcinoma in an oophorectomized-hysterectomized patient: a diagnostic dilemma

Extra Ovarian Primary Peritoneal Carcinoma (EOPPC) is a rare type of adenocarcinoma of the pelvic and abdominal peritoneum. The objective examination and the histological aspect of the neoplasia virtually overlaps with that of ovarian carcinoma. The reported case is that of a 72 year-old patient who had undergone a total hysterectomy with bilateral annessiectomy surgery 20 years earlier subsequently to a diagnosis for uterine leiomyomatosis. The patient came to our attention presenting recurring abdominal pain, constipation, weight loss, severe asthenia and fever. Her blood test results showed hypochromic microcytic anemia and a remarkable increase CA125 marker levels. Instrumental diagnostics with Ultrasound (US) and CT scans indicated the presence of a single peritoneal mass (10-12 cm diameter) close to the great epiploon. The patient was operated through a midline abdominal incision and the mass was removed with the great omentum. No primary tumor was found anywhere else in the abdomen and in the pelvis. The operation lasted approximately 50 minutes. The post-operative course was normal and the patient was discharged four days later. The histological exam of the neoplasia, supported by immunohistochemical analysis, showed a significant positivity for CA 125, vimentin and cytocheratin, presence of psammoma bodies, and cytoarchitectural pattern resembling that of a serous ovarian carcinoma even in absence of primitiveness, leading to a final diagnosis of EOPPC. The patient later underwent six cycles of chemotherapy with paclitaxel (135 mg/m2/24 hr) in association with cisplatin (75mg/m2). At the fourth year follow-up no sign of relapse was observed. .

Sol-gel biomimetic material designed to target CEA cancer biomarker

1st ASPIC International Congress

Sawhorse-type diruthenium tetracarbonyl complexes containing porphyrin-derived ligands as highly selective photosensitizers for female reproductive cancer cells.

Diruthenium tetracarbonyl complexes of the type [Ru2(CO)4(l2-g2-O2CR)2L2] containing a Ru-Ru backbone with four equatorial carbonyl ligands, two carboxylato bridges, and two axial two-electron ligands in a sawhorse-like geometry have been synthesized with porphyrin-derived substituents in the axial ligands [1: R is CH3, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin], in the bridging carboxylato ligands [2: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is PPh3; 3: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 1,3,5-triaza-7-phosphatricyclo [3.3.1.1]decane], or in both positions [4: RCO2H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin]. Compounds 1-3 were assessed on different types of human cancer cells and normal cells. Their uptake by cells was quantified by fluorescence and checked by fluorescence microscopy. These compounds were taken up by human HeLa cervix and A2780 and Ovcar ovarian carcinoma cells but not by normal cells and other cancer cell lines (A549 pulmonary, Me300 melanoma, PC3 and LnCap prostate, KB head and neck, MDAMB231 and MCF7 breast, or HT29 colon cancer cells). The compounds demonstrated no cytotoxicity in the absence of laser irradiation but exhibited good phototoxicities in HeLa and A2780 cells when exposed to laser light at 652 nm, displaying an LD50 between 1.5 and 6.5 J/cm2 in these two cell lines and more than 15 J/cm2 for the others. Thus, these types of porphyric compound present specificity for cancer cell lines of the female reproductive system and not for normal cells; thus being promising new organometallic photosensitizers.

In vivo therapeutic synergism of anti-epidermal growth factor receptor and anti-HER2 monoclonal antibodies against pancreatic carcinomas.

PURPOSE: Pancreatic carcinoma is highly resistant to therapy. Epidermal growth factor receptor (EGFR) and HER2 have been reported to be both dysregulated in this cancer. To evaluate the in vivo effect of binding both EGFR and HER2 with two therapeutic humanized monoclonal antibodies (mAb), we treated human pancreatic carcinoma xenografts, expressing high EGFR and low HER2 levels. EXPERIMENTAL DESIGN: Nude mice, bearing xenografts of BxPC-3 or MiaPaCa-2 human pancreatic carcinoma cell lines, were injected twice weekly for 4 weeks with different doses of anti-EGFR (matuzumab) and anti-HER2 (trastuzumab) mAbs either alone or in combination. The effect of the two mAbs, on HER receptor phosphorylation, was also studied in vitro by Western blot analysis. RESULTS: The combined mAb treatment significantly inhibited tumor progression of the BxPC-3 xenografts compared with single mAb injection (P = 0.006) or no treatment (P = 0.0004) and specifically induced some complete remissions. The two mAbs had more antitumor effect than 4-fold greater doses of each mAb. The significant synergistic effect of the two mAbs was confirmed on the MiaPaCa-2 xenograft and on another type of carcinoma, SK-OV-3 ovarian carcinoma xenografts. In vitro, the cooperative effect of the two mAbs was associated with a decrease in EGFR and HER2 receptor phosphorylation. CONCLUSIONS: Anti-HER2 mAb has a synergistic therapeutic effect when combined with an anti-EGFR mAb on pancreatic carcinomas with low HER2 expression. These observations may open the way to the use of these two mAbs in a large panel of carcinomas expressing different levels of the two HER receptors.

Dual Blockade of PD-1 and CTLA-4 Combined with Tumor Vaccine Effectively Restores T-Cell Rejection Function in Tumors.

Tumor progression is facilitated by regulatory T cells (Treg) and restricted by effector T cells. In this study, we document parallel regulation of CD8(+) T cells and Foxp3(+) Tregs by programmed death-1 (PD-1, PDCD1). In addition, we identify an additional role of CTL antigen-4 (CTLA-4) inhibitory receptor in further promoting dysfunction of CD8(+) T effector cells in tumor models (CT26 colon carcinoma and ID8-VEGF ovarian carcinoma). Two thirds of CD8(+) tumor-infiltrating lymphocytes (TIL) expressed PD-1, whereas one third to half of CD8(+) TIL coexpressed PD-1 and CTLA-4. Double-positive (PD-1(+)CTLA-4(+)) CD8(+) TIL had characteristics of more severe dysfunction than single-positive (PD-1(+) or CTLA-4(+)) TIL, including an inability to proliferate and secrete effector cytokines. Blockade of both PD-1 and CTLA-4 resulted in reversal of CD8(+) TIL dysfunction and led to tumor rejection in two thirds of mice. Double blockade was associated with increased proliferation of antigen-specific effector CD8(+) and CD4(+) T cells, antigen-specific cytokine release, inhibition of suppressive functions of Tregs, and upregulation of key signaling molecules critical for T-cell function. When used in combination with GVAX vaccination (consisting of granulocyte macrophage colony-stimulating factor-expressing irradiated tumor cells), inhibitory pathway blockade induced rejection of CT26 tumors in 100% of mice and ID8-VEGF tumors in 75% of mice. Our study indicates that PD-1 signaling in tumors is required for both suppressing effector T cells and maintaining tumor Tregs, and that PD-1/PD-L1 pathway (CD274) blockade augments tumor inhibition by increasing effector T-cell activity, thereby attenuating Treg suppression. Cancer Res; 73(12); 3591-603. ©2013 AACR.

Novel Functions of ErbB4 and NRG-1 in Development and Cancer

Cells communicate, or signal, with each other constantly to ensure proper functioning of tissues and organs. Cell signaling is often performed by interplay of receptors and ligands that bind these receptors. ErbB receptors (epidermal growth factor receptors, EGFR, HER) bind extracellular growth factors and transduce these signals inside of cells. ErbB dysfunction promotes carcinogenesis, and also results in numerous defects during normal development. This study focused on the functions of one member of the ErbB receptor family, ErbB4, and growth factor, neuregulin-1 (NRG-1), that can bind and activate ErbB4. This study aimed to find novel functions of ErbB4 and NRG-1. Hypoxia, or deficiency of oxygen, is common in cancer and ischemic conditions. One of the key findings of the work was the identification and characterization of a cross-talk between ErbB4 and Hypoxia-inducible factor 1α (HIF-1α), the central mediator of hypoxia signaling. ErbB4 activation by NRG-1 was found to increase HIF-1α activity. Interestingly, this regulation occurred in reciprocal manner as HIF-1α was also able to increase protein levels of NRG-1 and ErbB4. Moreover, expression of NRG-1 and ErbB4 was associated with HIF activity in vivo in human clinical samples and in mice. Reduction of functional ErbB4 in developing zebrafish embryos resulted in defects in development of the skeletal muscles. To study ErbB4 functions in pathological situation in humans, clinical samples of serous ovarian carcinoma were analyzed using tissue microarrays and real-time RT-PCR. A specific isoform of ErbB4, CYT-1, was associated with poor survival in serous ovarian cancer and increased anchorage independent growth of ovarian cancer cells in vitro. These observations demonstrate that ErbB4 and NRG-1 are essential regulators of cellular response to hypoxia, of development, and of ovarian carcinogenesis.