Shashikant Lele

Tumor-infiltrating NY-ESO-1–specific CD8+ T cells are negatively regulated by LAG-3 and PD-1 in human ovarian cancer

NY-ESO-1 is a “cancer-testis” antigen frequently expressed in epithelial ovarian cancer (EOC) and is among the most immunogenic tumor antigens defined to date. In an effort to understand in vivo tolerance mechanisms, we assessed the phenotype and function of NY-ESO-1–specific CD8+ T cells derived from peripheral blood lymphocytes (PBLs), tumor-infiltrating lymphocytes (TILs), and tumor-associated lymphocytes (TALs) of EOC patients with NY-ESO-1-expressing tumors, with or without humoral immunity to NY-ESO-1. Whereas NY-ESO-1–specific CD8+ T cells were readily detectable ex vivo with tetramers in TILs and TALs of seropositive patients, they were only detectable in PBLs following in vitro stimulation. Compared with PBLs, tumor-derived NY-ESO-1–specific CD8+ T cells demonstrated impaired effector function, preferential usage of dominant T-cell receptor, and enriched coexpression of inhibitory molecules LAG-3 and PD-1. Expression of LAG-3 and PD-1 on CD8+ T cells was up-regulated by IL-10, IL-6 (cytokines found in tumor ascites), and tumor-derived antigen-presenting cells. Functionally, CD8+LAG-3+PD-1+ T cells were more impaired in IFN-γ/TNF-α production compared with LAG-3+PD-1− or LAG-3−PD-1− subsets. Dual blockade of LAG-3 and PD-1 during T-cell priming efficiently augmented proliferation and cytokine production by NY-ESO-1–specific CD8+ T cells, indicating that antitumor function of NY-ESO-1-specific CD8+ T cells could potentially be improved by therapeutic targeting of these inhibitory receptors.

Detection of epithelial ovarian cancer using 1H-NMR-based metabonomics

Currently available serum biomarkers are insufficiently reliable to distinguish patients with epithelial ovarian cancer (EOC) from healthy individuals. Metabonomics, the study of metabolic processes in biologic systems, is based on the use of 1H‐NMR spectroscopy and multivariate statistics for biochemical data generation and interpretation and may provide a characteristic fingerprint in disease. In an effort to examine the utility of the metabonomic approach for discriminating sera from women with EOC from healthy controls, we performed 1H‐NMR spectroscopic analysis on preoperative serum specimens obtained from 38 patients with EOC, 12 patients with benign ovarian cysts and 53 healthy women. After data reduction, we applied both unsupervised Principal Component Analysis (PCA) and supervised Soft Independent Modeling of Class Analogy (SIMCA) for pattern recognition. The sensitivity and specificity tradeoffs were summarized for each variable using the area under the receiver‐operating characteristic (ROC) curve. In addition, we analyzed the regions of NMR spectra that most strongly influence separation of sera of EOC patients from healthy controls. PCA analysis allowed correct separation of all serum specimens from 38 patients with EOC (100%) from all of the 21 premenopausal normal samples (100%) and from all the sera from patients with benign ovarian disease (100%). In addition, it was possible to correctly separate 37 of 38 (97.4%) cancer specimens from 31 of 32 (97%) postmenopausal control sera. SIMCA analysis using the Coomans plot demonstrated that sera classes from patients with EOC, benign ovarian cysts and the postmenopausal healthy controls did not share multivariate space, providing validation for the class separation. ROC analysis indicated that the sera from patients with and without disease could be identified with 100% sensitivity and specificity at the 1H‐NMR regions 2.77 parts per million (ppm) and 2.04 ppm from the origin (AUC of ROC curve = 1.0). In addition, the regression coefficients most influential for the EOC samples compared to postmenopausal controls lie around δ3.7 ppm (due mainly to sugar hydrogens). Other loadings most influential for the EOC samples lie around δ2.25 ppm and δ1.18 ppm. These findings indicate that 1H‐NMR metabonomic analysis of serum achieves complete separation of EOC patients from healthy controls. The metabonomic approach deserves further evaluation as a potential novel strategy for the early detection of epithelial ovarian cancer.

Vaccination with an NY-ESO-1 peptide of HLA class I/II specificities induces integrated humoral and T cell responses in ovarian cancer.

NY-ESO-1 is a “cancer-testis” antigen expressed in epithelial ovarian cancer (EOC) and is among the most immunogenic tumor antigens defined to date. The NY-ESO-1 peptide epitope, ESO157–170, is recognized by HLA-DP4-restricted CD4+ T cells and HLA-A2- and A24-restricted CD8+ T cells. To test whether providing cognate helper CD4+ T cells would enhance the antitumor immune response, we conducted a phase I clinical trial of immunization with ESO157–170 mixed with incomplete Freunds adjuvant (Montanide ISA51) in 18 HLA-DP4+ EOC patients with minimal disease burden. NY-ESO-1-specific Ab responses and/or specific HLA-A2-restricted CD8+ and HLA-DP4-restricted CD4+ T cell responses were induced by a course of at least five vaccinations at three weekly intervals in a high proportion of patients. There were no serious vaccine-related adverse events. Vaccine-induced CD8+ and CD4+ T cell clones were shown to recognize NY-ESO-1-expressing tumor targets. T cell receptor analysis indicated that tumor-recognizing CD4+ T cell clones were structurally distinct from non-tumor-recognizing clones. Long-lived and functional vaccine-elicited CD8+ and CD4+ T cells were detectable in some patients up to 12 months after immunization. These results confirm the paradigm that the provision of cognate CD4+ T cell help is important for cancer vaccine design and provides the rationale for a phase II study design using ESO157–170 epitope or the full-length NY-ESO-1 protein for immunotherapy in patients with EOC.

Hormone-receptor expression and ovarian cancer survival: an Ovarian Tumor Tissue Analysis consortium study

BACKGROUND Few biomarkers of ovarian cancer prognosis have been established, partly because subtype-specific associations might be obscured in studies combining all histopathological subtypes. We examined whether tumour expression of the progesterone receptor (PR) and oestrogen receptor (ER) was associated with subtype-specific survival. METHODS 12 studies participating in the Ovarian Tumor Tissue Analysis consortium contributed tissue microarray sections and clinical data to our study. Participants included in our analysis had been diagnosed with invasive serous, mucinous, endometrioid, or clear-cell carcinomas of the ovary. For a patient to be eligible, tissue microarrays, clinical follow-up data, age at diagnosis, and tumour grade and stage had to be available. Clinical data were obtained from medical records, cancer registries, death certificates, pathology reports, and review of histological slides. PR and ER statuses were assessed by central immunohistochemistry analysis done by masked pathologists. PR and ER staining was defined as negative (<1% tumour cell nuclei), weak (1 to <50%), or strong (≥50%). Associations with disease-specific survival were assessed. FINDINGS 2933 women with invasive epithelial ovarian cancer were included: 1742 with high-grade serous carcinoma, 110 with low-grade serous carcinoma, 207 with mucinous carcinoma, 484 with endometrioid carcinoma, and 390 with clear-cell carcinoma. PR expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001) and high-grade serous carcinoma (log-rank p=0·0006), and ER expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001). We recorded no significant associations for mucinous, clear-cell, or low-grade serous carcinoma. Positive hormone-receptor expression (weak or strong staining for PR or ER, or both) was associated with significantly improved disease-specific survival in endometrioid carcinoma compared with negative hormone-receptor expression, independent of study site, age, stage, and grade (hazard ratio 0·33, 95% CI 0·21-0·51; p<0·0001). Strong PR expression was independently associated with improved disease-specific survival in high-grade serous carcinoma (0·71, 0·55-0·91; p=0·0080), but weak PR expression was not (1·02, 0·89-1·18; p=0·74). INTERPRETATION PR and ER are prognostic biomarkers for endometrioid and high-grade serous ovarian cancers. Clinical trials, stratified by subtype and biomarker status, are needed to establish whether hormone-receptor status predicts response to endocrine treatment, and whether it could guide personalised treatment for ovarian cancer. FUNDING Carraresi Foundation and others.

Ovarian Cancer Spheroid Cells with Stem Cell-Like Properties Contribute to Tumor Generation, Metastasis and Chemotherapy Resistance through Hypoxia-Resistant Metabolism

Cells with sphere forming capacity, spheroid cells, are present in the malignant ascites of patients with epithelial ovarian cancer (EOC) and represent a significant impediment to efficacious treatment due to their putative role in progression, metastasis and chemotherapy resistance. The exact mechanisms that underlie EOC metastasis and drug resistance are not clear. Understanding the biology of sphere forming cells may contribute to the identification of novel therapeutic opportunities for metastatic EOC. Here we generated spheroid cells from human ovarian cancer cell lines and primary ovarian cancer. Xenoengraftment of as few as 2000 dissociated spheroid cells into immune-deficient mice allowed full recapitulation of the original tumor, whereas >105 parent tumor cells remained non-tumorigenic. The spheroid cells were found to be enriched for cells with cancer stem cell-like characteristics such as upregulation of stem cell genes, self-renewal, high proliferative and differentiation potential, and high aldehyde dehydrogenase (ALDH) activity. Furthermore, spheroid cells were more aggressive in growth, migration, invasion, scratch recovery, clonogenic survival, anchorage-independent growth, and more resistant to chemotherapy in vitro. 13C-glucose metabolic studies revealed that spheroid cells route glucose predominantly to anaerobic glycolysis and pentose cycle to the detriment of re-routing glucose for anabolic purposes. These metabolic properties of sphere forming cells appear to confer increased resistance to apoptosis and contribute to more aggressive tumor growth. Collectively, we demonstrated that spheroid cells with cancer stem cell-like characteristics contributed to tumor generation, progression and chemotherapy resistance. This study provides insight into the relationship between tumor dissemination and metabolic attributes of human cancer stem cells and has clinical implications for cancer therapy.

Efficacy of vaccination with recombinant vaccinia and fowlpox vectors expressing NY-ESO-1 antigen in ovarian cancer and melanoma patients

Recombinant poxviruses (vaccinia and fowlpox) expressing tumor-associated antigens are currently being evaluated in clinical trials as cancer vaccines to induce tumor-specific immune responses that will improve clinical outcome. To test whether a diversified prime and boost regimen targeting NY-ESO-1 will result in clinical benefit, we conducted two parallel phase II clinical trials of recombinant vaccinia-NY-ESO-1 (rV-NY-ESO-1), followed by booster vaccinations with recombinant fowlpox-NY-ESO-1 (rF-NY-ESO-1) in 25 melanoma and 22 epithelial ovarian cancer (EOC) patients with advanced disease who were at high risk for recurrence/progression. Integrated NY-ESO-1-specific antibody and CD4+ and CD8+ T cells were induced in a high proportion of melanoma and EOC patients. In melanoma patients, objective response rate [complete and partial response (CR+PR)] was 14%, mixed response was 5%, and disease stabilization was 52%, amounting to a clinical benefit rate (CBR) of 72% in melanoma patients. The median PFS in the melanoma patients was 9 mo (range, 0–84 mo) and the median OS was 48 mo (range, 3–106 mo). In EOC patients, the median PFS was 21 mo (95% CI, 16–29 mo), and median OS was 48 mo (CI, not estimable). CD8+ T cells derived from vaccinated patients were shown to lyse NY-ESO-1-expressing tumor targets. These data provide preliminary evidence of clinically meaningful benefit for diversified prime and boost recombinant pox-viral-based vaccines in melanoma and ovarian cancer and support further evaluation of this approach in these patient populations.

Efficacy of Levo-1-Methyl Tryptophan and Dextro-1-Methyl Tryptophan in Reversing Indoleamine-2,3-Dioxygenase-Mediated Arrest of T-Cell Proliferation in Human Epithelial Ovarian Cancer

It has been reported that levo-1-methyl tryptophan (L-1MT) can block indoleamine-2,3-dioxygenase (IDO) expressed by human dendritic cells (DC), whereas dextro-1-methyl tryptophan (D-1MT) is inefficient. However, whether L-1MT or D-1MT can efficiently reverse IDO-induced arrest of human T-cell proliferation has not been clarified. Here, we show a marked immunosuppressive effect of IDO derived from INDO-transfected 293 cell, IDO+ ovarian cancer cells, and monocyte-derived DCs on CD4+ Th1 cells, CD8+ T cells, and natural killer cells derived from peripheral blood, ascites, and tumors of ovarian cancer patients. We found that, whereas L-1MT and D/L-1MT can restore proliferation of tumor-derived and peripheral blood T-cell subsets, D-1MT does not effectively restore IDO-induced arrest of T-cell proliferation. Although D-1MT inhibited kynurenine production at high concentrations, L-1MT was more effective in abrogating kynurenine generation and tryptophan depletion, whereas tryptophan was completely depleted by IDO even in the presence of high amounts of D-1MT. Together, the results indicate that, whereas the generation of tryptophan metabolites (kynurenines) by IDO is important in mediating suppression of T-cell proliferation, the degree to which tryptophan depletion is restored by 1MT is also critical in overcoming IDO-induced arrest of T-cell proliferation.

Epigenetic Potentiation of NY-ESO-1 Vaccine Therapy in Human Ovarian Cancer

Odunsi and colleagues show that the DNA methyltransferase inhibitor decitabine augmented the efficacy of the NY-ESO-1 vaccine and doxorubicin treatment of patients with refractory epithelial ovarian cancer, demonstrating the potential of the combined chemo-immunotherapy regimen. The cancer–testis/cancer germline antigen, NY-ESO-1, is a vaccine target in epithelial ovarian cancer (EOC), but its limited expression is a barrier to vaccine efficacy. As NY-ESO-1 is regulated by DNA methylation, we hypothesized that DNA methyltransferase inhibitors may augment NY-ESO-1 vaccine therapy. In agreement, global DNA hypomethylation in EOC was associated with the presence of circulating antibodies to NY-ESO-1. Preclinical studies using EOC cell lines showed that decitabine treatment enhanced both NY-ESO-1 expression and NY-ESO-1–specific CTL-mediated responses. On the basis of these observations, we performed a phase I dose-escalation trial of decitabine, as an addition to NY-ESO-1 vaccine and doxorubicin liposome chemotherapy, in 12 patients with relapsed EOC. The regimen was safe, with limited and clinically manageable toxicities. Both global and promoter-specific DNA hypomethylation occurred in blood and circulating DNAs, the latter of which may reflect tumor cell responses. Increased NY-ESO-1 serum antibodies and T-cell responses were observed in the majority of patients, and antibody spreading to additional tumor antigens was also observed. Finally, disease stabilization or partial clinical response occurred in six of ten evaluable patients. On the basis of these encouraging results, evaluation of similar combinatorial chemo-immunotherapy regimens in EOC and other tumor types is warranted. Cancer Immunol Res; 2(1); 37–49. ©2014 AACR.

Survival after ovarian cancer induced intestinal obstruction

Abstract Over a 9-year period, July 1, 1971, to June 30, 1980, 60 women with ovarian cancer underwent exploratory laparotomy for intestinal obstruction secondary to ovarian carcinoma. Surgery consisted of enterocolon bypass (23), ileostomy (9), small intestinal resection (3), colostomy (14), and exploratory laparotomy only in 11 women. In these 11 cases corrective surgery could not be carried out because of extensive tumor. The median survival for the 60 women was only 2.5 months ( cis -dichlorodiammine platinum should lead to improved survival for patients with ovarian cancer induced intestinal obstruction as compared to the poor survival documented for the past decade.

Peritoneal papillary carcinoma

Between 1977 and 1986, 325 patients with a diagnosis of ovarian carcinoma, peritoneal cancer, or malignant mesothelioma were reviewed with identification of 23 patients (7%) having peritoneal papillary cancer. Only 2 patients had disease confined to the pelvis and the rest had widespread abdominal disease. Various combination chemotherapeutic agents were used with over a 65% response rate to first-line chemotherapy. Twenty of the 23 patients received cisplatin combination chemotherapy with an overall response rate of 65%.