Programmed death-1 pathway blockade produces a synergistic antitumor effect: combined application in ovarian cancer

Carboplatin, paclitaxel, and pembrolizumab followed by pembrolizumab maintenance for primary treatment of incompletely resected epithelial ovarian cancer

Objective

Incompletely resected epithelial ovarian cancer represents a poor prognostic subset of patients. Novel treatment strategies are needed to improve outcomes for this population. We evaluated a treatment strategy combining platinum-based chemotherapy with pembrolizumab followed by pembrolizumab maintenance therapy in the first-line treatment after incomplete resection of epithelial ovarian cancer patients.

Methods

This was a single-arm, non-randomized pilot study of carboplatin, taxane, and immune checkpoint inhibitor, pembrolizumab, followed by 12 months of maintenance pembrolizumab in patients with incompletely resected epithelial ovarian cancer (EOC).

Results

A total of 29 patients were enrolled and evaluated for efficacy and safety. The best response to therapy was complete response in 16 (55%) patients, partial response in 9 (31%) patients, and 3 (10%) patients with progression of disease. The median progression-free survival (PFS) was 13.2 months. Grade 3 and 4 toxicities occurred in 20% of patients. In all, 7 patients discontinued therapy due to adverse events. Quality-of-life scores remained high during therapy. Response to therapy did not correlate with PD-L1 tumor expression.

Conclusions

Combination platinum-taxane therapy with pembrolizumab did not increase median progression-free survival in this cohort of patients.

Key message

EOC is an immunogenic disease, but immune checkpoint inhibitor therapy has yet to impact outcomes. The current study utilized pembrolizumab in combination with standard chemotherapy followed by a maintenance treatment strategy in incompletely resected EOC. Progression-free survival was not extended in this poor prognostic group with combined chemotherapy and immunotherapy.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT 027766582.

Overcoming the limitations of immunotherapy in pancreatic ductal adenocarcinoma: Combining radiotherapy and metabolic targeting therapy

As a novel anticancer therapy, immunotherapy has demonstrated robust efficacy against a few solid tumors but poor efficacy against pancreatic ductal adenocarcinoma (PDAC). This poor outcome is primarily attributable to the intrinsic cancer cell resistance and T-cell exhaustion, which is also the reason for the failure of conventional therapy. The present review summarizes the current PDAC immunotherapy avenues and the underlying resistance mechanisms. Then, the review discusses synergistic combination therapies, such as radiotherapy (RT) and metabolic targeting. Research suggests that RT boosts the antigen of PDAC, which facilitates the anti-tumor immune cell infiltration and exerts function. Metabolic reprogramming contributes to restoring the exhausted T cell function. The current review will help in tailoring combination regimens to enhance the efficacy of immunotherapy. In addition, it will help provide new approaches to address the limitations of the immunosuppressive tumor microenvironment (TME) by examining the relationship among immunotherapy, RT, and metabolism targeting therapy in PDAC.

Immunohistochemical Profiling of PD-1, PD-L1, CD8, MSI, and p53 and Prognostic Implications in Advanced Serous Ovarian Carcinoma: A Retrospective Study

Advanced high-grade serous ovarian carcinoma is a serious malignant neoplasm with a late diagnosis and high mortality rate. Even when treated with standard therapy, such as surgery followed by carboplatin and paclitaxel chemotherapy, the prognosis remains unfavorable. Immunotherapy is a treatment alternative that requires further study. Therefore, we aimed to evaluate the expression of PD-1, PD-L1, CD8, MSI (MLH1, MSH2, MSH6, and PMS2), and p53 in the paraffin samples of high-grade serous ovarian carcinoma. A retrospective study of 28 southern Brazilian patients with advanced serous ovarian carcinoma (EC III or IV) was conducted between 2009 and 2020. The expression of these proteins was evaluated using immunohistochemistry, and the results were correlated with the patients' clinicopathological data. At diagnosis, the mean age was 61 years, and the most common clinical stage (60%) was EC III. Among the cases, 84.6% exhibited p53 overexpression, 14.8% had MSI, 92.0% were sensitive to platinum, and more than 50.0% relapsed after treatment. Patients with MSI had a lower CD8/PD-1 ratio and more relapses (p = 0.03). In conclusion, analysis of immunotherapeutic markers in paraffin-embedded advanced serous ovarian carcinoma samples is feasible and may assist in prognosis.

Targeting the metabolism and immune system in pancreatic ductal adenocarcinoma: Insights and future directions

Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), presents a challenging landscape due to its complex nature and the highly immunosuppressive tumor microenvironment (TME). This immunosuppression severely limits the effectiveness of immune-based therapies. Studies have revealed the critical role of immunometabolism in shaping the TME and influencing PDAC progression. Genetic alterations, lysosomal dysfunction, gut microbiome dysbiosis, and altered metabolic pathways have been shown to modulate immunometabolism in PDAC. These metabolic alterations can significantly impact immune cell functions, including T-cells, myeloid-derived suppressor cells (MDSCs), and macrophages, evading anti-tumor immunity. Advances in immunotherapy offer promising avenues for overcoming immunosuppressive TME and enhancing patient outcomes. This review highlights the challenges and opportunities for future research in this evolving field. By exploring the connections between immunometabolism, genetic alterations, and the microbiome in PDAC, it is possible to tailor novel approaches capable of improving immunotherapy outcomes and addressing the limitations posed by immunosuppressive TME. Ultimately, these insights may pave the way for improved treatment options and better outcomes for PDAC patients.

Crosstalk of Immune Cells and Platelets in an Ovarian Cancer Microenvironment and Their Prognostic Significance

Ovarian cancer (OC) is one of the deadliest gynecological cancers, largely due to the fast development of metastasis and drug resistance. The immune system is a critical component of the OC tumor microenvironment (TME) and immune cells such as T cells, NK cells, and dendritic cells (DC) play a key role in anti-tumor immunity. However, OC tumor cells are well known for evading immune surveillance by modulating the immune response through various mechanisms. Recruiting immune-suppressive cells such as regulatory T cells (Treg cells), macrophages, or myeloid-derived suppressor cells (MDSC) inhibit the anti-tumor immune response and promote the development and progression of OC. Platelets are also involved in immune evasion by interaction with tumor cells or through the secretion of a variety of growth factors and cytokines to promote tumor growth and angiogenesis. In this review, we discuss the role and contribution of immune cells and platelets in TME. Furthermore, we discuss their potential prognostic significance to help in the early detection of OC and to predict disease outcome.

The Dual Blockade of the TIGIT and PD-1/PD-L1 Pathway as a New Hope for Ovarian Cancer Patients

The prognosis for ovarian cancer (OC) patients is poor and the five-year survival rate is only 47%. Immune checkpoints (ICPs) appear to be the potential targets in up-and-coming OC treatment. However, the response of OC patients to immunotherapy based on programmed cell death pathway (PD-1/PD-L1) inhibitors totals only 6-15%. The promising approach is a combined therapy, including other ICPs such as the T-cell immunoglobulin and ITIM domain/CD155/DNAX accessory molecule-1 (TIGIT/CD155/DNAM-1) axis. Preclinical studies in a murine model of colorectal cancer showed that the dual blockade of PD-1/PD-L1 and TIGIT led to remission in the whole studied group vs. the regression of the tumors with the blockade of a single pathway. The approach stimulates the effector activity of T cells and NK cells, and redirects the immune system activity against the tumor. The understanding of the synergistic action of the TIGIT and PD-1/PD-L1 blockade is, however, poor. Thus, the aim of this review is to summarize the current knowledge about the mode of action of the dual TIGIT and PD-1/PD-L1 blockade and its potential benefits for OC patients. Considering the positive impact of this combined therapy in malignancies, including lung and colorectal cancer, it appears to be a promising approach in OC treatment.

Programmed death ligand 1 and tumor-infiltrating CD8+ T lymphocytes are associated with the clinical features in meningioma

Objective

To investigate the expression of programmed death ligand-1 (PD-L1) and the levels of CD8+ tumor-infiltrating lymphocytes (TILs) in meningioma as well as determine the association between their levels and the clinical outcomes.

Methods

We performed a retrospective case-control study on 93 patients with meningioma. The patients showed tumor recurrence and were matched with the control patients without recurrence in their age, gender, admission time, tumor sites, tumor volume, peritumoral brain edema (PTBE), Simpson grade resection, WHO grade, postoperative radiotherapy, and the follow-up duration. We reviewed the clinical data of patients and performed immunohistochemistry analysis to investigate the PD-L1 expression and the levels of CD8+ TILs. Multivariate logistic regression was performed to analyze the association between clinical features and immune markers. The conditional logistic regression models were used to calculate the odds ratios (ORs) with 95% confidence intervals (CIs), and Kaplan–Meier analysis was performed to analyze tumor recurrence.

Results

Tumor volume was correlated with the PD-L1 expression (P = 0.003, HR = 5.288, 95%CI, 1.786–15.651). PTBE served as an independent predictor of CD8+ TIL levels (P = 0.001, HR = 0.176, 95%CI 0.065–0.477). The levels of CD8+ TILs were associated with tumor recurrence (P = 0.020, OR = 0.325, 95%CI, 0.125–0.840).

Conclusion

Tumor volume was associated with PD-L1 expression, and PTBE was an independent predictor of CD8+ TIL levels in meningioma. CD8+ TIL levels correlated with tumor recurrence in meningioma.

Focus on PD-1/PD-L1 as a Therapeutic Target in Ovarian Cancer

Ovarian cancer is considered one of the most aggressive and deadliest gynecological malignancies worldwide. Unfortunately, the therapeutic methods that are considered the gold standard at this moment are associated with frequent recurrences. Survival in ovarian cancer is associated with the presence of a high number of intra tumor infiltrating lymphocytes (TILs). Therefore, immunomodulation is considered to have an important role in cancer treatment, and immune checkpoint inhibitors may be useful for restoring T cell-mediated antitumor immunity. However, the data presented in the literature until now are not sufficient to allow for the identification and selection of patients who really respond to immunotherapy among those with ovarian cancer. Although there are some studies with favorable results, more prospective trials are needed in this sense. This review focuses on the current and future perspectives of PD-1/L1 blockade in ovarian cancer and analyzes the most important immune checkpoint inhibitors used, with the aim of achieving optimal clinical outcomes. Future studies and trials are needed to maximize the efficacy of immune checkpoint blockade therapy in ovarian cancer, as well as in all cancers, in general.

Prognostic and Predictive Role of Tumor-Infiltrating Lymphocytes (TILs) in Ovarian Cancer

In the last decade, tumor-infiltrating lymphocytes (TILs) have been recognized as clinically relevant prognostic markers for improved survival, providing the immunological basis for the development of new therapeutic strategies and showing a significant prognostic and predictive role in several malignancies, including ovarian cancer (OC). In fact, many OCs show TILs whose typology and degree of infiltration have been shown to be strongly correlated with prognosis and survival. The OC histological subtype with the higher presence of TILs is the high-grade serous carcinoma (HGSC) followed by the endometrioid subtype, whereas mucinous and clear cell OCs seem to contain a lower percentage of TILs. The abundant presence of TILs in OC suggests an immunogenic potential for this tumor. Despite the high immunogenic potential, OC has been described as a highly immunosuppressive tumor with a high expression of PD1 by TILs. Although further studies are needed to better define their role in prognostic stratification and the therapeutic implication, intraepithelial TILs represent a relevant prognostic factor to take into account in OC. In this review, we will discuss the promising role of TILs as markers which are able to reflect the anticancer immune response, describing their potential capability to predict prognosis and therapy response in OC.

Refractory lymphoma treated with chimeric antigen receptor T cells combined with programmed cell death-1 inhibitor: A case report

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a common aggressive non-Hodgkin's lymphoma (NHL), accounting for 30%-40% of adult NHL. Primary testicular (PT) lymphoma is an uncommon extranodal disease representing approximately 1%-2% of lymphoma. Approximately 30%–40% of patients are refractory to frontline therapy or relapse after complete remission. Refractory DLBCL responds poorly to other lines of chemotherapy, and experiences short-term survival.

CASE SUMMARY

We present a 41-year-old male patient who was diagnosed with PT-DLBCL. Further disease progression was observed after multiline chemotherapy. Chimeric antigen receptor T cells (CAR-T) therapy salvaged the patient. Unfortunately, a new mass was observed in the right adrenal area after six months. The patient was administered programmed cell death protein-1 (PD-1) inhibitor therapy and maintained progression-free survival at more than 17 mo of follow-up.

CONCLUSION

Our findings support the potential benefit of CAR-T combined with PD-1 inhibitor therapies in this type of relapsed and refractory PT-DLBCL.

PD-L1 Expression in Different Segments and Histological Types of Ovarian Cancer According to Lymphocytic Infiltrate

Background and Objectives: Ovarian cancer is the leading cause of death among gynecological tumors. PD-1/PD-L1 immunoregulatory mechanism is activated in ovarian cancers. Lymphocyte infiltration is a significant factor that affects its expression. We analyzed the correlation between localization of lymphocytic infiltrate and PD-L1 expression in epithelial ovarian tumors. Materials and Methods: PD-L1 expression was analyzed in 328 subjects, 122 with epithelial ovarian carcinoma, 42 with atypical proliferative tumor, and 164 with benign epithelial ovarian tumor. Expression in central and invasive tumor parts in epithelial ovarian carcinoma was combined with the most pronounced lymphocyte reaction. Immunohistochemical analysis was performed using the tissue microarray and correlated with a set of histopathology parameters. Results: PD-L1 expression was most prominent in epithelial ovarian carcinoma with different levels of expression observed between invasive and central tumor segments. A high level of PD-L1 expression on tumor cells was more frequently present in the invasive than in the central tumor parts (p < 0.001) only in high-grade serous ovarian carcinoma (HGSC). There was no significant correlation between peritumoral lymphocytic infiltrate and PD-L1 expression regardless of tumor segment. In the central tumor parts of HGSC, there was a correlation of intratumoral lymphocytic infiltrate with a higher level of PD-L1 expression (p = 0.003). Conclusions: The most prominent PD-L1 expression was observed in the invasive tumor parts of HGSC. Only the central parts of the HGSC exhibited significant PD-L1 expression in association with considerable intratumoral lymphocytic infiltrate.

Ovarian cancer modulates the immunosuppressive function of CD11b+Gr1+ myeloid cells via glutamine metabolism

OBJECTIVE

Immature CD11b + Gr1+ myeloid cells that acquire immunosuppressive capability, also known as myeloid-derived suppressor cells (MDSCs), are a heterogeneous population of cells that regulate immune responses. Our study's objective was to elucidate the role of ovarian cancer microenvironment in regulating the immunosuppressive function of CD11b+Gr1+ myeloid cells.

METHODS

All studies were performed using the intraperitoneal ID8 syngeneic epithelial ovarian cancer mouse model. Myeloid cell depletion and immunotherapy were carried out using anti-Gr1 mAb, gemcitabine treatments, and/or anti-PD1 mAb. The treatment effect was assessed by a survival curve, in situ luciferase-guided imaging, and histopathologic evaluation. Adoptive transfer assays were carried out between congenic CD45.2 and CD45.1 mice. Immune surface and intracellular markers were assessed by flow cytometry. ELISA, western blot, and RT-PCR techniques were employed to assess the protein and RNA expression of various markers. Bone marrow-derived myeloid cells were used for ex-vivo studies.

RESULTS

The depletion of Gr1+ immunosuppressive myeloid cells alone and in combination with anti-PD1 immunotherapy inhibited ovarian cancer growth. In addition to the adoptive transfer studies, these findings validate the role of immunosuppressive CD11b+Gr1+ myeloid cells in promoting ovarian cancer. Mechanistic investigations showed that ID8 tumor cells and their microenvironments produced recruitment and regulatory factors for immunosuppressive CD11b+Gr1+ myeloid cells. CD11b+Gr1+ myeloid cells primed by ID8 tumors showed increased immunosuppressive marker expression and acquired an energetic metabolic phenotype promoted primarily by increased oxidative phosphorylation fueled by glutamine. Inhibiting the glutamine metabolic pathway reduced the increased oxidative phosphorylation and decreased immunosuppressive markers' expression and function. Dihydrolipoamide succinyl transferase (DLST), a subunit of α-KGDC in the TCA cycle, was found to be the most significantly elevated gene in tumor-primed myeloid cells. The inhibition of DLST reduced oxidative phosphorylation, immunosuppressive marker expression and function in myeloid cells.

CONCLUSION

Our study shows that the ovarian cancer microenvironment can regulate the metabolism and function of immunosuppressive CD11b + Gr1+ myeloid cells and modulate its immune microenvironment. Targeting glutamine metabolism via DLST in immunosuppressive myeloid cells decreased their activity, leading to a reduction in the immunosuppressive tumor microenvironment. Thus, targeting glutamine metabolism has the potential to enhance the success of immunotherapy in ovarian cancer.

Clinical and Prognostic Value of Antigen-Presenting Cells with PD-L1/PD-L2 Expression in Ovarian Cancer Patients

The latest literature demonstrates the predominant role of the programmed cell death axis (PD-1/PD-L1/PD-L2) in ovarian cancer (OC) pathogenesis. However, data concerning this issue is ambiguous. Our research aimed to evaluate the clinical importance of PD-L1/PD-L2 expression in OC environments. We evaluated the role of PD-L1/PD-L2 in OC patients (n = 53). The analysis was performed via flow cytometry on myeloid (mDCs) and plasmacytoid dendritic cells (pDCs) and monocytes/macrophages (MO/MA) in peripheral blood, peritoneal fluid (PF), and tumor tissue (TT). The data were correlated with clinicopathological characteristics and prognosis of OC patients. The concentration of soluble PD-L1 (sPD-L1) and PD-1 in the plasma and PF were determined by ELISA. We established an accumulation of PD-L1+/PD-L2+ mDCs, pDCs, and MA in the tumor microenvironment. We showed an elevated level of sPD-L1 in the PF of OC patients in comparison to plasma and healthy subjects. sPD-L1 levels in PF showed a positive relationship with Ca125 concentration. Moreover, we established an association between higher sPD-L1 levels in PF and shorter survival of OC patients. An accumulation of PD-L1+/PD-L2+ mDCs, pDCs, and MA in the TT and high sPD-L1 levels in PF could represent the hallmark of immune regulation in OC patients.

Antibody drug conjugates in gastrointestinal cancer: From lab to clinical development

The antibody-drug conjugates (ADCs) are one the fastest growing biotherapeutics in oncology and are still in their infancy in gastrointestinal (GI) cancer for clinical applications to improve patient survival. The ADC based approach is developed with tumor specific antigen, antibody carrying cytotoxic agents to precisely target and deliver chemotherapeutics at the tumor site. To date, 11 ADCs have been approved by US-FDA, and more than 80 are in the clinical development phase for different oncological indications. However, The ADCs based therapies in GI cancers are still far from having high-efficient clinical outcomes. The limited success of these ADCs and lessons learned from the past are now being used to develop a newer generation of ADC against GI cancers. In this review, we did a comprehensive assessment of the key components of ADCs, including tumor marker, antibody, cytotoxic payload, and linkage strategy, with a focus on technical improvement and some future trends in the pipeline for clinical translation. The various preclinical and clinical ADCs used in gastrointestinal malignancies, their target, composition and bioconjugation, along with preclinical and clinical outcomes, are discussed. The emphasis is also given to new generation ADCs employing novel mAb, payload, linker, and bioconjugation methods are also included.

A Review of the Clinical Characteristics and Novel Molecular Subtypes of Endometrioid Ovarian Cancer

Ovarian cancer is one of the most common gynecologic cancers that has the highest mortality rate. Endometrioid ovarian cancer, a distinct subtype of epithelial ovarian cancer, is associated with endometriosis and Lynch syndrome, and is often accompanied by synchronous endometrial carcinoma. In recent years, dysbiosis of the microbiota within the female reproductive tract has been suggested to be involved in the pathogenesis of endometrial cancer and ovarian cancer, with some specific pathogens exhibiting oncogenic having been found to contribute to cancer development. It has been shown that dysregulation of the microenvironment and accumulation of mutations are stimulatory factors in the progression of endometrioid ovarian carcinoma. This would be a potential therapeutic target in the future. Simultaneously, multiple studies have demonstrated the role of four molecular subtypes of endometrioid ovarian cancer, which are of particular importance in the prediction of prognosis. This literature review aims to compile the potential mechanisms of endometrioid ovarian cancer, molecular characteristics, and molecular pathological types that could potentially play a role in the prediction of prognosis, and the novel therapeutic strategies, providing some guidance for the stratified management of ovarian cancer.

Potential Impact of Human Cytomegalovirus Infection on Immunity to Ovarian Tumours and Cancer Progression

Ovarian cancer (OC) is one of the most common, and life-threatening gynaecological cancer affecting females. Almost 75% of all OC cases are diagnosed at late stages, where the 5-year survival rate is less than 30%. The aetiology of the disease is still unclear, and there are currently no screening method nor effective treatment strategies for the advanced disease. A growing body of evidence shows that human cytomegalovirus (HCMV) infecting more than 50% of the world population, may play a role in inducing carcinogenesis through its immunomodulatory activities. In healthy subjects, the primary HCMV infection is essentially asymptomatic. The virus then establishes a life-long chronic latency primarily in the hematopoietic progenitor cells in the bone marrow, with periodic reactivation from latency that is often characterized by high levels of circulating pro-inflammatory cytokines. Currently, infection-induced chronic inflammation is considered as an essential process for OC progression and metastasis. In line with this observation, few recent studies have identified high expressions of HCMV proteins on OC tissue biopsies that were associated with poor survival outcomes. Active HCMV infection in the OC tumour microenvironment may thus directly contribute to OC progression. In this review, we highlight the potential impact of HCMV infection-induced immunomodulatory effects on host immune responses to OC that may promote OC progression.

Clinical and pathological significance of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer

We investigated programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer (HGSOC) and its relationship to tumor infiltrating lymphocytes (TIL) and prognosis. Formalin fixed paraffin embedded (FFPE) samples of 94 HGSOC cases were included in the study. Immunohistochemical analysis (CD3, CD4, CD8, PD-1 and PD-L1) was performed. Samples were analyzed for expression of immune proteins in the peritumoral stromal and intratumoral areas, scored, and expression was correlated with overall survival, stage, and age. PD-L1 staining ratio with a score greater than 0 was found to have lower survival. There were two positive staining patterns, patchy/diffuse and patchy/focal patterns, in 24 (25.5%) cases. Considering the threshold value ≥5%, we demonstrated that the PD-L1 positive cancer cell membrane immunoreactivity rate and patchy/diffuse PD-L1 expression were 9.6% (n = 9). There was statistically significant relationship between high PD-1 scores and PD-L1 cases of ≥ 5%. A statistically significant difference was found between PD-L1 staining and survival in patients with a threshold ≥ 5%. However an appropriate rate for treatment was determined in 9.6% cases. There was a statistically significant correlation between PD-1 positive TIL score and intratumoral CD3, peritumoral stromal CD3, intratumoral CD4 and intratumoral CD8 positive cells. Survival was lower in cases with higher PD-L1 positive stromal TIL score.

CXCR4 inhibition modulates the tumor microenvironment and retards the growth of B16-OVA melanoma and Renca tumors

To determine whether blockade of the chemokine receptor CXCR4 might alter the tumor microenvironment and inhibit tumor growth, we tested the efficacy of the CXCR4 antagonist X4-136 as a single agent and in combination with various immune checkpoint inhibitors in the syngeneic murine melanoma model B16-OVA. We also tested its activity alone and in combination with axitinib in the renal cancer model Renca. We found that X4-136 exhibited potent single agent antitumor activity in the B16-OVA model that was additive to that of an anti-PDL1 antibody. The antitumor activities were associated with a reduction in the number of immunosuppressive regulatory T cells and myeloid-derived suppressor cells and an increase in the number of tumor-specific CD8/perforin cells in the tumor-microenvironment. Apart from these immune effects, X4-136 alone and in combination with checkpoint inhibitors inhibited the Akt/FOXO-3a cell survival pathway in vitro and in vivo, suggesting that it might have antitumor activity independent of its effects on immune cell trafficking. Similar effects on tumor growth and cytotoxic T lymphocytes infiltration were observed in the Renca model. These studies show that the effects of CXCR4 blockade on immune cell trafficking might serve as a useful adjunct to immune checkpoint inhibitors and other therapies in the treatment of cancer.

Programmed Death-1 Receptor (PD-1) as a Potential Prognosis Biomarker for Ovarian Cancer Patients

Aim

Ovarian cancer (OC) is one of the most lethal gynecological malignancies. Recent studies suggest a crucial role of the PD-1/PD-L1 pathway in OC pathogenesis. Therefore, our study aimed at evaluation of the clinical importance of PD-1 expression in ovarian cancer patients.

Patients and Methods

In this study, we investigated the role of PD-1 in OC patients (n=50) by analyzing its expression on CD4⁺ and CD8⁺ T cells in three OC environments: peripheral blood (PB), peritoneal fluid (PF), and tumor (TT) as well as soluble PD-1 (sPD-1) in plasma and PF in terms of their clinical and prognostic significance. T cells with PD-1 expression were analyzed using flow cytometry. The concentration of sPD-1 was determined with the use of ELISA. Our research demonstrated differences in PD-1 expression on CD4⁺ and CD8⁺ T cells in the OC environments.

Results

We found an elevated level of CD4⁺PD-1⁺ T cells in tumor and PF, compared to PB. Additionally, we found the highest percentage of CD8⁺ PD-1⁺ in tumor, compared to PB and PF. The levels of sPD-1 were higher (p<0.0001) in plasma than in PF. For the first time, we discovered that the higher level of CD4⁺PD-1⁺ T cells in the circulation and the higher sPD-1 level in plasma predict poor survival of OC patients.

Conclusion

We suggest that PD-1 could be a predictive biomarker for OC patients and successful immunotherapy.

Understanding and addressing barriers to successful adenovirus-based virotherapy for ovarian cancer

Ovarian cancer is the leading cause of death among women with gynecological cancer, with an overall 5-year survival rate below 50% due to a lack of specific symptoms, late stage at time of diagnosis and a high rate of recurrence after standard therapy. A better understanding of heterogeneity, genetic mutations, biological behavior and immunosuppression in the tumor microenvironment have allowed the development of more effective therapies based on anti-angiogenic treatments, PARP and immune checkpoint inhibitors, adoptive cell therapies and oncolytic vectors. Oncolytic adenoviruses are commonly used platforms in cancer gene therapy that selectively replicate in tumor cells and at the same time are able to stimulate the immune system. In addition, they can be genetically modified to enhance their potency and overcome physical and immunological barriers. In this review we highlight the challenges of adenovirus-based oncolytic therapies targeting ovarian cancer and outline recent advances to improve their potential in combination with immunotherapies.

The Perfect Combination: Enhancing Patient Response to PD-1-Based Therapies in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, with an overall 5-year survival of only 47%. As the development of novel targeted therapies is drastically necessary in order to improve patient survival, current EOC clinical trials have heavily focused on immunotherapeutic approaches, centered upon programmed cell death 1 (PD-1) inhibitors. While PD-1 monotherapies have only exhibited modest responses for patients, it has been theorized that in order to enhance EOC patient response to immunotherapy, combinatorial regimens must be investigated. In this review, unique challenges to EOC PD-1 response will be discussed, along with a comprehensive description of both preclinical and clinical studies evaluating PD-1-based combinatorial therapies. Promising aspects of PD-1-based combinatorial approaches are highlighted, while also discussing specific preclinical and clinical areas of research that need to be addressed, in order to optimize EOC patient immunotherapy response.

TIGIT enhances CD4+ regulatory T-cell response and mediates immune suppression in a murine ovarian cancer model

Ovarian cancer (OC) is the fifth-leading cause of cancer-related death in women with a pathogenesis involving activation of regulatory T cells (Tregs). The T-cell immunoglobulin and ITIM domain (TIGIT) is a well-known immune checkpoint molecule that inhibits T-cell responses. However, the role of TIGIT in OC is not comprehensively understood. In this study, we revealed crucial functions of TIGIT in the development and progression of OC. ID8 cells were used to establish a murine OC model. TIGIT expression was increased in immune cells of OC mice, particularly in CD4⁺ Tregs. Anti-TIGIT monoclonal antibodies (mAb) were used to block the function of TIGIT in OC mice, and we found that the anti-TIGIT treatment reduced the proportion of CD4⁺ Tregs, but did not affect CD4⁺ and CD8⁺ T cells or natural killer cells. Splenic CD4⁺ Tregs from OC mice were isolated after the anti-TIGIT treatment, and their functioning was examined. Inhibition of TIGIT lowered the degree of immunosuppression induced by CD4⁺ Tregs. A survival curve suggested that anti-TIGIT treatment can improve the survival rate of OC in mice. We conclude that TIGIT enhanced CD4⁺ Tregs response and mediated immunosuppression in the OC model. Our data suggest that inhibition of TIGIT is a potential therapeutic target in OC patients.

Expression of PD-L1 in ovarian cancer and its synergistic antitumor effect with PARP inhibitor

BACKGROUND

Ovarian cancer samples were studied to determine the expression of programmed death ligand-1 (PD-L1) and its relationship with prognosis, and to explore the effect and potential mechanism of a PARP inhibitor combined with PD-L1 monoclonal antibody for the treatment of ovarian cancer.

MATERIALS AND METHODS

PD-L1 expression in paraffin-embedded tissues of ovarian cancer was detected by immunohistochemistry (IHC). Flow cytometry was used to detect PD-L1 expression in TILs. Furthermore, we investigated the mechanism of the upregulation of PD-L1 expression by PARP inhibitors in vitro and verified the combined effect in vivo.

RESULTS

Our study demonstrated that PD-L1 expression in ovarian cancer tissues was associated with the FIGO stage (P = 0.026). OS was significantly lower in high PD-L1 expression group than in the low expression group (P = 0.0005, HR = 2.689), PD-L1 high expression (P = 0.023, HR = 2.275) and FIGO stage (P = 0.024, HR = 11.229) were independent risk factors affecting the survival and prognosis of ovarian cancer patients. Flow cytometry test suggested that PD-L1⁺ expression was negatively correlated with CD8⁺ T cell count in ovarian cancer cells (P = 0.054, r = -0.624). In vitro experiments revealed that PD-L1 expression of ovarian cancer cell lines was upregulated after intervention with PARP inhibitors through the Chk1 pathway. The results of in vivo experiments suggested that the growth volume and quality of tumors in the combination group were significantly lower than those in control group (P < 0.05).

CONCLUSIONS

PARP inhibitors could induce upregulation of PD-L1 expression by promoting phosphorylation of chk1. Antagonistic PD-L1 could reverse the inhibitory effect of PARP inhibitors on CD8⁺T cells, and had synergistic antitumor effect with PARP inhibitors.

Chlorin e6-Conjugated and PEGylated Immune Checkpoint Inhibitor Nanocomposites for Pulmonary Metastatic Colorectal Cancer

Here we demonstrate theranostic immune checkpoint inhibitor nanocomposites (ICI NC) having an improved tumor targeting ability in pulmonary metastatic colon cancer model. Atezolizumab, a PD-L1 antibody, was conjugated with methoxy poly(ethylene glycol) (MePEG) and chlorin e6 (Ce6) via cathepsin-B-sensitive peptide as a linkage (named as ICI nanocomposites, ICI NC). This ICI NC is delivered to tumor sites enriched with tumor-specific enzymes such as cathepsin B, whereas undesired ICI exposure to normal tissue is avoided. When ICI NC were incubated with cathepsin B, Ce6 was released from ICI NC with increased fluorescence intensity in cathepsin B dose-dependent manner, which was by degradation of the peptide and then liberated Ce6 was activated in the aqueous solution. In animal pulmonary metastasis model using CT26 cells, ICI NC showed superior tumor targetability, i.e., fluorescence intensity was significantly strong in the mouse lung having metastatic tumor. On the contrary, cathepsin-B-deficient carriers such as atezolizumab-Ce6 conjugates or atezolizumab-Ce6/MePEG conjugates showed strong fluorescence intensity in the liver as well as lung. Our proposed ICI NC may be used for theranostic cancer therapy with superior tumor specificity of releasing ICI and Ce6 into tumor microenvironment, thereby showing an efficient inhibitory effect on pulmonary metastasis of CT26 cells.

MicroRNA 155 Contributes to Host Immunity against Leishmania donovani but Is Not Essential for Resolution of Infection

CD4⁺ T helper 1 (Th1) cells producing interferon gamma (IFN-γ) are critical for the resolution of visceral leishmaniasis (VL). MicroRNA 155 (miR155) promotes CD4⁺ Th1 responses and IFN-γ production by targeting suppressor of cytokine signaling-1 (SOCS1) and Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP-1) and therefore could play a role in the resolution of VL. To determine the role of miR155 in VL, we monitored the course of Leishmania donovani infection in miR155 knockout (miR155KO) and wild-type (WT) C57BL/6 mice. miR155KO mice displayed significantly higher liver and spleen parasite loads than WT controls and showed impaired hepatic granuloma formation. However, parasite growth eventually declined in miR155KO mice, suggesting the induction of a compensatory miR155-independent antileishmanial pathway. Leishmania antigen-stimulated splenocytes from miR155KO mice produced significantly lower levels of Th1-associated IFN-γ than controls. Interestingly, at later time points, levels of Th2-associated interleukin-4 (IL-4) and IL-10 were also lower in miR155KO splenocyte supernatants than in WT mice. On the other hand, miR155KO mice displayed significantly higher levels of IFN-γ, iNOS, and TNF-α gene transcripts in their livers than WT mice, indicating that distinct organ-specific antiparasitic mechanisms were involved in control of L. donovani infection in miR155KO mice. Throughout the course of infection, organs of miR155KO mice showed significantly more PDL1-expressing Ly6C^hi inflammatory monocytes than WT mice. Conversely, blockade of Ly6C^hi inflammatory monocyte recruitment in miR155KO mice significantly reduced parasitic loads, indicating that these cells contributed to disease susceptibility. In conclusion, we found that miR155 contributes to the control of L. donovani but is not essential for infection resolution.

T-cell therapies for T-cell lymphoma

T-cell lymphomas represent a subpopulation of non-Hodgkin lymphomas with poor outcomes when treated with conventional chemotherapy. A variety of novel agents have been introduced as new treatment strategies either as first-line treatment or in conjunction with chemotherapy. Immunotherapy has been demonstrated to be a promising area for new therapeutics, including monoclonal antibodies and adoptive cellular therapeutics. T-cell therapeutics have been shown to have significant success in the treatment of B-cell malignancies and are rapidly expanding as potential treatment options for other cancers including T-cell lymphomas. Although treating T-cell lymphomas with T-cell therapeutics has unique challenges, multiple targets are currently being studied both preclinically and in clinical trials.

Ras association domain family protein 1a hypermethylation and PD-L1 expression in ovarian cancer: A retrospective study of 112 cases

OBJECTIVE

This study assessed the interrelationships between Ras association domain family protein 1a (RASSF1A) gene hypermethylation, PD-L1 protein expression, and the clinicopathological characteristics of 112 ovarian cancer (OC) samples.

METHODS

Formalin-fixed paraffin-embedded OC tissue samples from surgical resection were assessed. Bisulfite pyrosequencing and immunohistochemistry were applied to detect RASSF1A gene methylation and PD-L1 protein expression in tumor cells, respectively. RASSF1A gene methylation and PD-L1 protein expression levels were analyzed against clinicopathological features and prognosis through standard statistical methods.

RESULTS

Of the 112 OC samples, 49.1% (55/112) exhibited RASSF1A gene hypermethylation. The frequency of RASSF1A hypermethylation was significantly higher in nonserous subtype (73.0%), early stage (66.7%), and nonrecurrent OC (62.9%, p < 0.05). Among all samples, 61.6% (69/112) were positive for PD-L1 protein expression in tumor cells. No significant differences in PD-L1 expression were identified for age, menstrual status, histological type, tumor location, grade, stage, lymph node metastasis, or prognosis (p > 0.05). RASSF1A methylation and PD-L1 expression were not correlated (p > 0.05).

CONCLUSIONS

This was the first study linking RASSF1A hypermethylation variability to PD-L1 expression and clinicopathological characteristics of OC. Epigenetic alteration of RASSF1A was closely associated with nonserous subtype, early stage, and nonrecurrent OC, indicating that RASSF1A hypermethylation may play a role in early detection of OC. Expression of PD-L1 had no relationship with the studied clinicopathological characteristics or RASSF1A hypermethylation in the 112 OC samples.

Advances in Immunotherapy and Periocular Malignancy

Immunotherapy has significantly advanced the field of oncology in recent decades. Understanding normal immunosurveillance, as well as the ways in which tumor cells have evolved to evade it, has provided the knowledge for development of drugs that allow one's own immune system to target and destroy malignant cells (immunotherapy). Cutaneous malignancies are particularly sensitive to this class of drugs. In a very sensitive anatomic region such as the periocular tissue, where surgical excision may come with significant morbidity, this technology has had a strong impact in the successful treatment of historically challenging tumors.

Soluble PD-1 ligands regulate T-cell function in Waldenstrom macroglobulinemia

Although immune checkpoint molecules regulate the progression of certain cancers, their significance in malignant development of Waldenstrom macroglobulinemia (WM), an incurable low-grade B-cell lymphoma, remains unknown. Recently, cytokines in the bone marrow (BM) microenvironment are shown to contribute to the pathobiology of WM. Here, we investigated the impact of cytokines, including interleukin-6 (IL-6) and IL-21, on immune regulation and particularly on the programmed death-1 (PD-1) and its ligands PD-L1 and PD-L2. We showed that IL-21, interferon γ, and IL-6 significantly induced PD-L1 and PD-L2 gene expression in WM cell lines. Increased PD-L1 and PD-L2 messenger RNA was also detected in patients' BM cells. Patients' nonmalignant BM cells, including T cells and monocytes, showed increased PD-L1, but minimal or undetectable PD-L2 surface expression. There was also very modest PD-L1 and PD-L2 surface expression by malignant WM cells, suggesting that ligands are cleaved from the cell surface. Levels of soluble ligands were higher in patients' BM plasma and blood serum than controls. Furthermore, IL-21 and IL-6 increased secreted PD-L1 in the culture media of WM cell lines, implying that elevated levels of soluble PD-1 ligands are cytokine mediated. Soluble PD-1 ligands reduced T-cell proliferation, phosphorylated extracellular signal-regulated kinase and cyclin A levels, mitochondrial adenosine triphosphate production, and spare respiratory capacity. In conclusion, we identify that soluble PD-1 ligands are elevated in WM patients and, in addition to surface-bound ligands in WM BM, could regulate T-cell function. Given the capability of secreted forms to be bioactive at distant sites, soluble PD-1 ligands have the potential to promote disease progression in WM.

Immunotherapies based on PD-1/PD-L1 pathway inhibitors in ovarian cancer treatment

Immunotherapies based on anti-programmed death 1/programmed death ligand 1 (PD-1/PD-L1) pathway inhibitors may turn out effective in ovarian cancer (OC) treatment. They can be used in combination with standard therapy and are especially promising in recurrent and platinum-resistant OC. There is growing evidence that the mechanism of the PD-1/PD-L1 pathway can be specific for a particular histological cancer type. Interestingly, the data have shown that the PD-1/PD-L1 pathway blockade may be effective, especially in the endometrioid type of OC. It is important to identify the cause of anti-tumor immune response suppression and exclude its other mechanisms in OC patients. It is also necessary to conduct subsequent studies to confirm in which OC cases the treatment is effective and how to select patients and combine drugs to improve patient survival.

Reverse signaling via PD-L1 supports malignant cell growth and survival in classical Hodgkin lymphoma

Treatment with programmed death-1 (PD-1) blocking antibodies results in high overall response rates in refractory and relapsed classical Hodgkin lymphoma (cHL) patients, indicating that PD-1/PD-1 ligand interactions are integral to progression of this disease. Given the genetically driven increased PD-L1/2 expression in HL, we hypothesized that reverse signaling through PD-1 ligands may be a potential mechanism contributing to the growth and survival of Hodgkin Reed–Sternberg (HRS) cells in cHL. Our data show that engagement of PD-L1 using an agonistic monoclonal antibody increases cell survival and proliferation and reduces apoptosis in HL cell lines. We show that HL patients have significantly higher serum levels of soluble PD-1 than healthy controls, and find that both membrane-bound and soluble forms of PD-1 are able to induce PD-L1 reverse signaling in HL cell lines. PD-L1 signaling, which is associated with activation of the MAPK pathway and increased mitochondrial oxygen consumption, is reversed by PD-1 blockade. In summary, our data identify inhibition of reverse signaling through PD-L1 as an additional mechanism that accounts for clinical responses to PD-1 blockade in cHL.

Expression and prognostic value of PD-L1 and PD-L2 in ovarian cancer

Background

In the present study, we aimed to investigate the expression and prognostic value of co-stimulatory molecules, programmed death ligand-1 (PD-L1) and PD-L2, in ovarian cancer (OC).

Methods

Immunohistochemical (IHC) staining was used to assess the expressions of PD-L1 and PD-L2 in 77 cases of OC, and 10 cases of benign ovarian cyst were employed as negative controls. Moreover, χ² test was used to analyze the correlation between the PD-L1/PD-L2 expression and clinicopathological parameters. Kaplan-Meier method was used to compare the effects of PD-L1/PD-L2 expression level on the overall survival (OS) of OC patients.

Results

PD-L1 and PD-L2 were mainly expressed on membrane and in cytoplasm of OC cells. The high-expression rate of PD-L1 and PD-L2 in OC tissues was 44.16% (34/77) and 22.08% (17/77), respectively. The expression of PD-L1 in OC cells was significantly correlated with FIGO stage (P=0.026), while its expression was not significantly correlated with other clinicopathological parameters. There was no significant correlation between PD-L2 and any clinicopathological parameters. Kaplan-Meier survival analysis showed that the OS of high PD-L1 expression group was significantly shorter compared with the low PD-L1 expression group (HR =2.689, 95% CI: 1.400–5.163). Patients with high PD-L2 expression also exhibited significantly shorter OS (HR =2.204, 95% CI: 1.037–4.682). Multivariable analysis displayed that high expression of PD-L1 (HR =2.275, 95% CI: 1.120–4.169), high expression of PD-L2 (HR =2.314, 95% CI: 1.136–4.714) and FIGO stage (HR =11.229, 95% CI: 1.373–91.865) were independent prognostic factors of OC. When negative expressions of both PD-L1 and PD-L2 were used as a combined prognostic factor, the OS was significantly prolonged (HR =3.396, 95% CI: 1.858–6.029). According to our previous studies, patients with negative PD-L1 expression and high T-bet⁺ TIL infiltration have higher OS than other patients. Patients with positive PD-L1 expression and low T-bet⁺ TIL infiltration exhibit the shortest OS. Collectively, our findings provided the basis for PD-1/PD-L1 or PD-1/PD-L2 blockade therapy for OC patients.

Conclusions

Co-stimulatory molecules, PD-L1 and PD-L2, were highly expressed in OC tissues, and their expression levels were correlated with FIGO stage, age and prognosis. These results suggested that PD-L1 and PD-L2 were involved in the occurrence and development of malignant OC, indicating their potential value in clinical diagnosis and prognosis of OC.

Developing a Bright NIR-II Fluorophore with Fast Renal Excretion and Its Application in Molecular Imaging of Immune Checkpoint PD-L1

Fluorescence imaging in the second near-infrared (NIR-II) window holds impressive advantages of enhanced penetration depth and improved signal-to-noise ratio. Bright NIR-II fluorophores with renal excretion ability and low tissue accumulation are favorable for in vivo molecular imaging applications as they can render the target-mediated molecular imaging process easily distinguishable. Here, a probe (anti-PD-L1-BGP6) comprising a fluorophore (IR-BGP6) covalently bonded to the programmed cell death ligand-1 monoclonal antibody (PD-L1 mAb) for molecular imaging of immune checkpoint PD-L1 (a targeting site upregulated in various tumors for cancer imaging) in the NIR-II window is reported. Through molecular optimization, the bright NIR-II fluorophore IR-BGP6 with fast renal excretion (≈91% excretion in general through urine within the first 10 h postinjection) is developed. The conjugate anti-PD-L1-BGP6 succeeds in profiling PD-L1 expression and realizes efficient noninvasive molecular imaging in vivo, achieving a tumor to normal tissue (T/NT) signal ratio as high as ≈9.5. Compared with the NIR-II fluorophore with high nonspecific tissue accumulation, IR-BGP6 derived PD-L1 imaging significantly enhances the molecular imaging performance, serving as a strong tool for potentially studying underlying mechanism of immunotherapy. The work provides rationales to design renal-excreted NIR-II fluorophores and illustrate their advantages for in vivo molecular imaging.

Prognostic Value of Lymphocyte Activation Gene-3 (LAG-3) Expression in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant epithelial tumor with a high incidence in East Asia and the Middle East. The outcomes for ESCC patients are usually not optimal due to the recurrence and metastasis. This study is aim to examine the expression and the prognostic value of LAG-3 in ESCC. We applied immunohistochemistry analysis to examine the expression of LAG-3, CD4 and CD8 in 287 ESCC cohorts. Our study demonstrated that the decreased LAG-3 expression was significantly associated with CD4 tumor-infiltrated lymphocytes (TILs) (p=0.000), CD8 TILs (p=0.000), and the advanced clinical stages (p=0.041) by Chi-square analysis. Kaplan-Meier survival analysis revealed that higher LAG-3 expression were positively correlated with a better overall survival (OS) (p=0.010) and better progression free survival (PFS) (p=0.006), especially in the patients at stages T1-2 status (p=0.001, OS; p=0.001, PFS), N0 status (p=0.036, OS; p=0.050, PFS), and early stages (I-II) (p=0.006, OS; p=0.008, PFS). Both high of CD4 TIL /CD8 TIL ratio and LAG-3 expression were correlated with longer OS and PFS. Cox proportional hazards regression analysis showed that LAG-3 is an independent biomarker of survival (HR, 0.724; 95% CI 0.526-0.995; p = 0.047) (p=0.036). Taken together, we found that high expression of LAG-3 was correlated with an improved survival and LAG-3 is an independent predictor of survival, suggesting that LAG-3 may serve as a useful immune marker for the prognosis of ESCC.

Trial Watch: Toll-like receptor agonists in cancer immunotherapy

Toll-like receptor (TLR) agonists demonstrate therapeutic promise as immunological adjuvants for anticancer immunotherapy. To date, three TLR agonists have been approved by US regulatory agencies for use in cancer patients. Additionally, the potential of hitherto experimental TLR ligands to mediate clinically useful immunostimulatory effects has been extensively investigated over the past few years. Here, we summarize recent preclinical and clinical advances in the development of TLR agonists for cancer therapy.

PD-1 blockade enhances radio-immunotherapy efficacy in murine tumor models

PURPOSE

It has become increasingly clear in cancer treatment that radiotherapy can be enhanced by immunotherapy. In the present study, we evaluated a novel triple combination therapy consisting of local radiotherapy, intratumoral CpG, and systemic PD-1 blockade in lung cancer models.

METHODS

The efficacy of a novel triple therapy was examined by recording tumor volume and survival time. The immunologic effects of this novel triple therapy were evaluated by the frequency and percentage of immune cells and cytokines using flow cytometry.

RESULTS

This triple combination proved more effective than its subcomponents and its positive antitumor effects included reducing tumor growth and improving host survival. The antitumor effect was not only observed in directly irradiated tumors but also in at distant tumor sites in a CD8+ T-cell-dependent fashion. Phenotypic analyses of CD8+ T cells revealed that the triple combination therapy increased the percentage of effector memory T cells in the spleen. Furthermore, the combination therapy significantly increased the frequency of IFN-γ and TNF-α-positive-CD8+ tumor-infiltrating lymphocytes (TIL) and mature-activated dendritic cells (DCs) within treated tumors, indicating that the antitumor effects likely depend on the activation of a DC subset specialized in antigen crosspriming to induce cytotoxic lymphocyte (CTLs). In addition, the triple therapy reduced immunosuppressive factors, like regulatory T cells (Tregs) in the spleen and tumor microenvironment while inducing the robust systemic antitumor effect. Finally, the triple treatment was, indeed, well tolerated and had a little effect on the hemogram and lung.

CONCLUSIONS

These results suggest that this triple therapy promotes a local antitumor immune response with systemic consequences. The efficacy and limited toxicity of this strategy are attractive for clinical translation.

Sperm Protein 17 Expression by Murine Epithelial Ovarian Cancer Cells and Its Impact on Tumor Progression

The cancer testis antigen sperm protein 17 (Sp17) is a promising antigenic target in epithelial ovarian cancer (EOC) vaccine development. However, its role in ovarian cancer is unclear. We isolated and expanded Sp17⁺ and Sp17⁻ clones from the murine EOC cell line ID8, and compared their in-vitro cell growth characteristics and in-vivo tumorigenicity. We also examined the potential co-expression of molecules that may influence cancer cell survival and interaction with immune cells. These include stimulatory and immunosuppressive molecules, such as major histocompatibility class I molecules (MHC I), MHC II, cytotoxic T lymphocyte associated antigen-4 (CTLA-4), CD73, CD39, tumor necrosis factor receptor II (TNFRII), signal transducer and activator of transcription 3 (STAT3) and programmed death-ligand 1 (PD-L1). Whilst the presence of Sp17 was not correlated with the ID8 cell proliferation/growth capacity in vitro, it was critical to enable progressive tumor formation in vivo. Flow cytometry revealed that Sp17⁺ ID8 cells displayed higher expression of both STAT3 and PD-L1, whilst MHC II expression was lower. Moreover, Sp17^high (PD-L1⁺MHCII⁻) cell populations showed significantly enhanced resistance to Paclitaxel-induced cell death in vitro compared to Sp17^low (PD-L1⁻MHCII⁺) cells, which was associated in turn with increased STAT3 expression. Together, the data support Sp17 as a factor associated with in-vivo tumor progression and chemo-resistance, validating it as a suitable target for vaccine development.

Targeted therapy and immunotherapy for platinum-refractory advanced ovarian adenosquamous carcinoma: a case report

Background

Ovarian adenosquamous carcinoma is an extremely rare type of ovarian histology. Platinum-refractory disease is also uncommon, but can be fatal because of the lack of available treatment options. To date, there is no study or case report on platinum-refractory ovarian adenosquamous carcinoma or its relevant treatment.

Case presentation

Herein, we report the case of a 38-year-old Chinese woman with platinum-refractory advanced ovarian adenosquamous carcinoma who received clinical benefit from poly adenosine diphosphate ([ADP] ribose) polymerase and programmed death-1 inhibitors after failure of prior multiline chemotherapies and antiangiogenic agents. The targeted therapy and immunotherapy-controlled disease deterioration and improved performance status. Thus far, the patient has survived longer than 15 months, and she is taking nivolumab as maintenance treatment.

Conclusion

Targeted therapy and immunotherapy may be options for rare categories of ovarian cancer, but this warrants more clinical evidence of efficacy and toxicity.

Stratification of ovarian tumor pathology by expression of programmed cell death-1 (PD-1) and PD-ligand- 1 (PD-L1) in ovarian cancer

BACKGROUND

Ovarian cancer is the major cause of death among gynecologic cancers with 75% of patients diagnosed with advanced disease, and only 20% of these patients having a survival duration of five years. Treatments blocking immune checkpoint molecules, programmed cell death (PD-1) or its ligand PD-ligand- I (PD-L1) have produced a beneficial and prolonged effect in a subgroup of these patients. However, there is debate in the literature concerning the prognostic value of the expression of these molecules in tumors, with immunotherapy responsiveness, and survival. We evaluated the immune landscape of the ovarian tumor microenvironment of patients, by measuring the impact of the expression of tumor PD-1, PD-L1 and infiltrating lymphocytes on stage and grade of tumors and survival, in a cohort of 55 patients with gynecologic malignancies. Most patients under study were diagnosed with advanced disease ovarian cancer.

RESULTS

Our studies revealed that a low density of PD-1 and of PD-L1 expressing cells in tumor tissue were significantly associated with advanced disease (P = 0.028 and P = 0.033, respectively). Moreover, PD-L1 was expressed significantly more often in high grade tumors (41.5%) than in low grade tumors of patients (7.7%) (P = 0.040). The presence of CD3 or of FoxP3 infiltrating cells with PD-L1 in patient tumors did not impact the significance of the association of PD-L1 with high grade tumors (P = 0.040), and our analyses did not show an association between the presence of PD-1 or PD-L1 and survival.

CONCLUSIONS

We conclude that a subgroup of advanced disease ovarian cancer patients with high grade tumors, expressing PD-L1, may be prime candidates for immunotherapy targeting PD-1 signaling.

Stratification of ovarian tumor pathology by expression of programmed cell death-1 (PD-1) and PD-ligand- 1 (PD-L1) in ovarian cancer

Background

Ovarian cancer is the major cause of death among gynecologic cancers with 75% of patients diagnosed with advanced disease, and only 20% of these patients having a survival duration of five years. Treatments blocking immune checkpoint molecules, programmed cell death (PD-1) or its ligand PD-ligand- I (PD-L1) have produced a beneficial and prolonged effect in a subgroup of these patients. However, there is debate in the literature concerning the prognostic value of the expression of these molecules in tumors, with immunotherapy responsiveness, and survival.

We evaluated the immune landscape of the ovarian tumor microenvironment of patients, by measuring the impact of the expression of tumor PD-1, PD-L1 and infiltrating lymphocytes on stage and grade of tumors and survival, in a cohort of 55 patients with gynecologic malignancies. Most patients under study were diagnosed with advanced disease ovarian cancer.

Results

Our studies revealed that a low density of PD-1 and of PD-L1 expressing cells in tumor tissue were significantly associated with advanced disease (P = 0.028 and P = 0.033, respectively). Moreover, PD-L1 was expressed significantly more often in high grade tumors (41.5%) than in low grade tumors of patients (7.7%) (P = 0.040). The presence of CD3 or of FoxP3 infiltrating cells with PD-L1 in patient tumors did not impact the significance of the association of PD-L1 with high grade tumors (P = 0.040), and our analyses did not show an association between the presence of PD-1 or PD-L1 and survival.

Conclusions

We conclude that a subgroup of advanced disease ovarian cancer patients with high grade tumors, expressing PD-L1, may be prime candidates for immunotherapy targeting PD-1 signaling.

Electronic supplementary material

The online version of this article (10.1186/s13048-018-0414-z) contains supplementary material, which is available to authorized users.

Stratification of ovarian tumor pathology by expression of programmed cell death-1 (PD-1) and PD-ligand- 1 (PD-L1) in ovarian cancer

BACKGROUND

Ovarian cancer is the major cause of death among gynecologic cancers with 75% of patients diagnosed with advanced disease, and only 20% of these patients having a survival duration of five years. Treatments blocking immune checkpoint molecules, programmed cell death (PD-1) or its ligand PD-ligand- I (PD-L1) have produced a beneficial and prolonged effect in a subgroup of these patients. However, there is debate in the literature concerning the prognostic value of the expression of these molecules in tumors, with immunotherapy responsiveness, and survival. We evaluated the immune landscape of the ovarian tumor microenvironment of patients, by measuring the impact of the expression of tumor PD-1, PD-L1 and infiltrating lymphocytes on stage and grade of tumors and survival, in a cohort of 55 patients with gynecologic malignancies. Most patients under study were diagnosed with advanced disease ovarian cancer.

RESULTS

Our studies revealed that a low density of PD-1 and of PD-L1 expressing cells in tumor tissue were significantly associated with advanced disease (P = 0.028 and P = 0.033, respectively). Moreover, PD-L1 was expressed significantly more often in high grade tumors (41.5%) than in low grade tumors of patients (7.7%) (P = 0.040). The presence of CD3 or of FoxP3 infiltrating cells with PD-L1 in patient tumors did not impact the significance of the association of PD-L1 with high grade tumors (P = 0.040), and our analyses did not show an association between the presence of PD-1 or PD-L1 and survival.

CONCLUSIONS

We conclude that a subgroup of advanced disease ovarian cancer patients with high grade tumors, expressing PD-L1, may be prime candidates for immunotherapy targeting PD-1 signaling.

Janus-Faced Myeloid-Derived Suppressor Cell Exosomes for the Good and the Bad in Cancer and Autoimmune Disease

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells originally described to hamper immune responses in chronic infections. Meanwhile, they are known to be a major obstacle in cancer immunotherapy. On the other hand, MDSC can interfere with allogeneic transplant rejection and may dampen autoreactive T cell activity. Whether MDSC-Exosomes (Exo) can cope with the dangerous and potentially therapeutic activities of MDSC is not yet fully explored. After introducing MDSC and Exo, it will be discussed, whether a blockade of MDSC-Exo could foster the efficacy of immunotherapy in cancer and mitigate tumor progression supporting activities of MDSC. It also will be outlined, whether application of native or tailored MDSC-Exo might prohibit autoimmune disease progression. These considerations are based on the steadily increasing knowledge on Exo composition, their capacity to distribute throughout the organism combined with selectivity of targeting, and the ease to tailor Exo and includes open questions that answers will facilitate optimizing protocols for a MDSC-Exo blockade in cancer as well as for strengthening their therapeutic efficacy in autoimmune disease.

Emerging Therapeutics to Overcome Chemoresistance in Epithelial Ovarian Cancer: A Mini-Review

Ovarian cancer is the fifth leading cause of cancer death among women and the most lethal gynecologic malignancy. One of the leading causes of death in high-grade serous ovarian cancer (HGSOC) is chemoresistant disease, which may present as intrinsic or acquired resistance to therapies. Here we discuss some of the known molecular mechanisms of chemoresistance that have been exhaustively investigated in chemoresistant ovarian cancer, including drug efflux pump multidrug resistance protein 1 (MDR1), the epithelial–mesenchymal transition, DNA damage and repair capacity. We also discuss novel therapeutics that may address some of the challenges in bringing approaches that target chemoresistant processes from bench to bedside. Some of these new therapies include novel drug delivery systems, targets that may halt adaptive changes in the tumor, exploitation of tumor mutations that leave cancer cells vulnerable to irreversible damage, and novel drugs that target ribosomal biogenesis, a process that may be uniquely different in cancer versus non-cancerous cells. Each of these approaches, or a combination of them, may provide a greater number of positive outcomes for a broader population of HGSOC patients.