Application Of Adoptive Immunotherapy In Ovarian Cancer

Dendritic Cell Vaccines: A Promising Approach in the Fight against Ovarian Cancer

Simple Summary

With an overall 5-year survival of only 20% for advanced-stage ovarian cancer patients, enduring and effective therapies are a highly unmet clinical need. Current standard-of-care therapies are able to improve progression-free survival; however, patients still relapse. Moreover, immunotherapy has not resulted in clear patient benefits so far. In this situation, dendritic cell vaccines can serve as a potential therapeutic addition against ovarian cancer. In the current review, we provide an overview of the different dendritic cell subsets and the roles they play in ovarian cancer. We focus on the advancements in dendritic cell vaccination against ovarian cancer and highlight the key outcomes and pitfalls associated with currently used strategies. Finally, we address future directions that could be taken to improve the dendritic cell vaccination outcomes in ovarian cancer.

Abstract

Ovarian cancer (OC) is the deadliest gynecological malignancy in developed countries and is the seventh-highest cause of death in women diagnosed with cancer worldwide. Currently, several therapies are in use against OC, including debulking surgery, chemotherapy, as well as targeted therapies. Even though the current standard-of-care therapies improve survival, a vast majority of OC patients relapse. Additionally, immunotherapies have only resulted in meager patient outcomes, potentially owing to the intricate immunosuppressive nexus within the tumor microenvironment. In this scenario, dendritic cell (DC) vaccination could serve as a potential addition to the therapeutic options available against OC. In this review, we provide an overview of current therapies in OC, focusing on immunotherapies. Next, we highlight the potential of using DC vaccines in OC by underscoring the different DC subsets and their functions in OC. Finally, we provide an overview of the advances and pitfalls of current DC vaccine strategies in OC while providing future perspectives that could improve patient outcomes.

Preliminary Safety and Potential Effect of 6B11-OCIK Adoptive Cell Therapy Against Platinum-Resistant Recurrent or Refractory Ovarian Cancer

Ovarian cancer is a leading cause of death among gynecological malignancies, and novel therapies are urgently needed. Here we report preliminary findings on the potential safety and efficacy of 6B11-OCIK, an adoptive cell therapy of autologous T cells induced by the humanized anti-idiotypic antibody 6B11 minibody plus dendritic cells and cytokines, against platinum-resistant recurrent or refractory ovarian cancer in three patients. We found that 6B11-OCIK treatment was safe and well tolerated after five cycles of intravenous infusion with an initial dose of 1–2×10⁹ cells and a dose-climbing strategy. Hemoglobin, platelets, white cell count, creatinine or liver enzyme values, coagulation function, kidney and heart function were not significantly affected over the duration of therapy. Two of the three enrolled patients showed potentially drug-related grade 1 and 2 weakness, and no other adverse events were observed. Of the three enrolled patients, one had stable disease and two showed disease progression. The patient with favorable clinical efficacy had better immune response as measured by 6B11-OCIK proliferation capacity, activation ability of CD3+CD8+ tumor-specific cytotoxic T lymphocytes and CD3+CD56+ cytokine-induced killer cells, and tumor cell killing efficiency. Changes in circulating tumor cells after treatment were consistent with serum level CA125 in the patient with stable disease (both decreased), while differences were observed in the two patients with disease progression (increased CA125 in both and decreased CTC in the patient with better immune response), suggesting that variation of circulating tumor cells was more consistent with immune response and reflected efficacy directly. This preliminary study suggested that autologous 6B11-OCIK treatment was safe and had potential clinical efficacy against ovarian cancer. Patients with better immune response had more favorable efficacy. In addition to imaging, CA125 and immunophenotypes, CTC monitoring may represent a potential indicator of immunotherapy response.

Ovarian Cancer: Therapeutic Strategies to Overcome Immune Suppression

Ovarian cancer generally escapes diagnosis until the advanced stages. High-grade serous ovarian cancer (HGSOC) is the most frequently occurring form of this malaise and is a disease which has the highest mortality rate of gynecologic cancers. Over recent years it has been revealed that the course of such cancers can be significantly influenced by the nature of immune cells in tumors at the time of diagnosis and by immune cells induced by therapy. Numerous investigators have since focused on disease biology to identify biomarkers or therapeutic targets. Yet, while over the past decade there have been significant improvements in state-of-the-art surgery for ovarian cancer as frontline therapy, there have been limited advancements in the development of novel curative or management drugs for this disease. This chapter discusses the major elements of immune suppression in HGSOC from a biological viewpoint, mechanisms of overcoming resistance to therapies, and recent therapy aimed at improving patient care and survival.

Increased Expression of UBE2T Predicting Poor Survival of Epithelial Ovarian Cancer: Based on Comprehensive Analysis of UBE2s, Clinical Samples, and the GEO Database

Ubiquitin-conjugating enzymes E2 (UBE2) have been reported in the microenvironment of various malignant tumors, but their correlation with ovarian cancer (OC) remains elusive. This study aimed to systematically analyze the expression patterns, prognostic value, genetic variation, and biological functions of 12 members of the UBE2 gene family in OC through the Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), Kaplan-Meier plotter, cBioPortal, and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) databases, respectively. We found that the mRNA levels of UBE2C, UBE2N, UBE2S, and UBE2T were significantly upregulated in OC compared with those in normal ovarian tissue. In patients with serous ovarian cancer (SOC), UBE2A, UBE2B, UBE2C, UBE2G, UBE2R2, and UBE2T upregulation were associated with poor overall survival. Moreover, UBE2A, UBE2N, UBE2R2, and UBE2T upregulation and UBE2G downregulation were associated with poor progression-free survival. UBE2T exhibited a strong correlation with OC and was thus further examined. We found that UBE2T has a high diagnostic accuracy (area under the receiver operating characteristic curve = 0.969) in epithelial ovarian cancer (EOC). Immunohistochemical assays and the Gene Expression Omnibus (GEO) database revealed that UBE2T was significantly upregulated in EOC compared with that in borderline tumors, benign tumors, and normal ovarian tissues, and its high expression was associated with poor prognosis. The Cox model showed that UBE2T upregulation was an independent risk factor affecting the prognosis of EOC and SOC. Furthermore, UBE2T was associated with specific immune cells and was mainly involved in cell cycle-related events. Genomic analysis showed that TP53 and TTN mutations were associated with UBE2T expression. Gene copy number amplification and hypomethylation may be responsible for UBE2T upregulation in OC. In conclusion, UBE2 family members may play a role in the development of OC. Specifically, UBE2T could serve as a new prognostic marker and therapeutic target for this disease. (IRB Approval No. 2020PS533K).