Immunotherapy of Ovarian Cancer with Particular Emphasis on the PD-1/PDL-1 as Target Points

Identification of PDZD11 as a Potential Biomarker Associated with Immune Infiltration for Diagnosis and Prognosis in Epithelial Ovarian Cancer

Purpose

Evidence has indicated that PDZD11 is involved in regulating adherens junction. However, the distinct effect of its aberrant expression on epithelial ovarian cancer (EOC) awaits clarification.

Methods

In this study, public databases (Gene Expression Omnibus, The Cancer Genome Atlas, and The Genotype-Tissue Expression), online analysis tools (Kaplan-Meier plotter and TIMER), and data analysis methods (Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and the CIBERSORT algorithm) were fully utilized to analyze the differential expression, diagnostic efficiency, prognostic significance, potential function, and correlation with immune infiltration of PDZD11. The differential expression of PDZD11 was tested by immunohistochemistry in EOC tissues (78 cases) and control tissues (37 cases).

Results

Our results indicate that PDZD11 was remarkably overexpressed in EOC, which was associated with advanced cancer stages, no lymphatic metastasis status, and poor prognosis. Moreover, PDZD11 played a role in cell adhesion, cell proliferation, and immune responses. Also, PDZD11 was significantly related to the abundances of infiltrating immune cells in EOC, including neutrophils, macrophages, dendritic cells, CD8+ T cells, and CD4+ T cells, and its expression was positively co-expressed with well-known immune checkpoints, including TIGIT, TIM3, LAG3, CTLA4, and PD-1.

Conclusion

These results suggest that PDZD11 could be a potential diagnostic and prognostic biomarker associated with immune infiltration in EOC, and our findings might help elucidate the function of PDZD11 in carcinogenesis.

Efficacy and safety of PD-1/PD-L1 immune checkpoint inhibitors in the treatment of recurrent ovarian cancer: A systematic review and meta-analysis

BACKGROUND

Recurrent ovarian cancer (OC) presents a significant therapeutic challenge with limited treatment success. Programmed cell death protein 1 (PD-1/PD-L1) immune checkpoint inhibitors have emerged as a potential treatment avenue, necessitating a systematic review and meta-analysis to evaluate their efficacy and safety.

METHODS

Adhering to preferred reporting items for systematic reviews and meta-analyses guidelines, we conducted a comprehensive literature search across PubMed, Embase, Web of Science, and Cochrane Library, culminating in the inclusion of studies focusing on the treatment of recurrent OC with PD-1/PD-L1 inhibitors. Studies were evaluated using the Newcastle-Ottawa Scale and analyzed using fixed or random effects models depending on heterogeneity levels.

RESULTS

Our search yielded 1215 articles, with 6 meeting the inclusion criteria for final analysis. Studies varied in size and reported median age, overall survival (OS), progression-free survival (PFS), and adverse events. The meta-analysis showed improved Objective Response Rates (ORR), Disease Control Rate (DCR), and PFS in patients treated with PD-1/PD-L1 inhibitors. The overall adverse event rate was 17.9%, indicating a need for careful patient selection and monitoring. No significant publication bias was detected, enhancing the reliability of our findings.

CONCLUSIONS

PD-1/PD-L1 inhibitors offer a promising treatment option for recurrent OC, improving ORR, DCR, and PFS. However, the higher incidence of adverse events necessitates a cautious approach to their use. Future research should focus on long-term outcomes, biomarker identification, and optimal combination therapies.

Dysregulation of Peripheral Blood Mononuclear Cells and Immune-Related Proteins during the Early Post-Operative Immune Response in Ovarian Cancer Patients

Surgical treatment is a cornerstone of ovarian cancer (OC) therapy and exerts a substantial influence on the immune system. Immune responses also play a pivotal and intricate role in OC progression. The aim of this study was to investigate the dynamics of immune-related protein expression and the activity of peripheral blood mononuclear cells (PBMCs) in OC patients, both before surgery and during the early postoperative phase. The study cohort comprised 23 OC patients and 20 non-cancer controls. A comprehensive analysis of PBMCs revealed significant pre-operative downregulation in the mRNA expression of multiple immune-related proteins, including interleukins, PD-1, PD-L1, and HO-1. This was followed by further dysregulation during the first 5 post-operative days. Although most serum interleukin concentrations showed only minor changes, a distinct increase in IL-6 and HO-1 levels was observed post-operatively. Reduced metabolic and phagocytic activity and increased production of reactive oxygen species (ROS) were observed on day 1 post-surgery. These findings suggest a shift towards immune tolerance during the early post-operative phase of OC, potentially creating a window for treatment. Further research into post-operative PBMC activity could lead to the development of new or improved treatment strategies for OC.

Current Understanding on Why Ovarian Cancer Is Resistant to Immune Checkpoint Inhibitors

The standard treatment of ovarian cancer (OC) patients, including debulking surgery and first-line chemotherapy, is unsatisfactory because of recurrent episodes in the majority (~70%) of patients with advanced OC. Clinical trials have shown only a modest (10-15%) response of OC individuals to treatment based on immune checkpoint inhibitors (ICIs). The resistance of OC to therapy is caused by various factors, including OC heterogeneity, low density of tumor-infiltrating lymphocytes (TILs), non-cellular and cellular interactions in the tumor microenvironment (TME), as well as a network of microRNA regulating immune checkpoint pathways. Moreover, ICIs are the most efficient in tumors that are marked by high microsatellite instability and high tumor mutation burden, which is rare among OC patients. The great challenge in ICI implementation is connected with distinguishing hyper-, pseudo-, and real progression of the disease. The understanding of the immunological, molecular, and genetic mechanisms of OC resistance is crucial to selecting the group of OC individuals in whom personalized treatment would be beneficial. In this review, we summarize current knowledge about the selected factors inducing OC resistance and discuss the future directions of ICI-based immunotherapy development for OC patients.

Evaluation of immunotherapy efficacy in gynecologic cancer

Various immunotherapies have demonstrated remarkable success over the past few decades, and have been approved for the treatment of different cancer types. However, patient responses to immunotherapy are variable, and approximately 50% of cases are refractory to these agents. Tumor biomarker-based stratification of cases may therefore help identify subpopulations that are sensitive/resistant to immunotherapy; it may also improve prediction of response in various cancers including gynecologic cancer. These biomarkers include the tumor mutational burden, microsatellite instability, mismatch repair deficiency, T cell-inflamed gene expression profile, programmed cell death protein 1 ligand 1, tumor-infiltrating lymphocytes, and numerous other genomic alterations. Future directions in the treatment of gynecologic cancer include the utilization of these biomarkers to select ideal candidates. This review focused on recent advances in the predictive ability of molecular biomarkers in patients with gynecologic cancer who undergo immunotherapy. The most recent developments in combined immunotherapy and targeted therapy strategies and novel immune interventions against gynecologic cancers have also been discussed.

Programmed cell death-1 and its ligands: Current knowledge and possibilities in immunotherapy

Programmed Cell Death-1 (PCD-1) is a key immune checkpoint receptor, which mainly expresses on activated T, B, Dendritic (DC), Natural Killer (NK), and Treg cells. On the surface of activated T-cells, PCD-1 expression is upregulated after the recognition of peripherals antigens by T cells; subsequently, the elevated binding of PD-1 to Programmed Death Ligand-1 (PD-L1) and Programmed Death Ligand-2 (PD-L2) becomes a key step for downstream inhibitory signaling. Although the role of PD-L1 has been evaluated more thoroughly by clinical research, and PD-L1 has also been used more widely in the clinical setting, PD-L2 also plays an important role in the negative regulation of T-cells, one of the necessary conditions that lead to immune tolerance. Expression of PD-L1 either in tumors or in infiltrating immune cells has been verified predominantly by Immunohistochemistry (IHC) in a variety of tumors, suggesting a role for the PD-1/PD-L1 axis as a prognostic trait and therapeutic target across multiple histotypes. The complex interplay between these factors plays a major role in the diffusion and clinical application of PD-L1 IHC assays as predictive biomarkers of response to PD-1/PD-L1 inhibitors. Checkpoint blockades are registered for the treatment of various cancers, including gynecological malignancies.

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.

The Role of TIM-3 and LAG-3 in the Microenvironment and Immunotherapy of Ovarian Cancer

Ovarian cancer has the highest mortality rate among gynecologic malignancies. The main treatment options are surgical removal of the tumor and chemotherapy. Cancer treatment has been revolutionized by immunotherapy, which has developed explosively over the past two decades. Clinical anticancer strategies used in immunotherapy include therapies based on the inhibition of PD-1, PD-L1 or CTLA-4. Despite encouraging results, a large proportion of cancer patients are resistant to these therapies or eventually develop resistance. It is important to perform research that will focus on immunotherapy based on other immune checkpoint inhibitors. The aim of the review was to analyze studies considering the expression of TIM-3 and LAG-3 in the ovarian cancer microenvironment and considering immunotherapy for ovarian cancer that includes antibodies directed against TIM-3 and LAG-3. As the data showed, the expression of the described immune checkpoints was shown in different ways. Higher TIM-3 expression was associated with a more advanced tumor stage. Both TIM-3 and LAG-3 were co-expressed with PD-1 in a large proportion of studies. The effect of LAG-3 expression on progression-free survival and/or overall survival is inconclusive and certainly requires further study. Co-expression of immune checkpoints prompts combination therapies using anti-LAG-3 or anti-TIM-3. Research on immune checkpoints, especially TIM-3 and LAG-3, should be further developed.

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.

Clinical Relevance of Soluble Forms of Immune Checkpoint Molecules sPD-1, sPD-L1, and sCTLA-4 in the Diagnosis and Prognosis of Ovarian Cancer

It is crucial to find new diagnostic and prognostic biomarkers. A total of 80 patients were enrolled in the study. The study group consisted of 37 patients with epithelial ovarian cancer, and the control group consisted of 43 patients with benign ovarian cystic lesions. Three proteins involved in the immune response were studied: PD-1, PD-L1, and CTLA-4. The study material was serum and peritoneal fluid. The ROC curve was plotted, and the area under the curve was calculated to characterize the sensitivity and specificity of the studied parameters. Univariate and multivariate analyses were performed simultaneously using the Cox regression model. The cut-off level of CTLA-4 was 0.595 pg/mL, with the sensitivity and specificity of 70.3% and 90.7% (p = 0.000004). Unfavorable prognostic factors determined in serum were: PD-L1 (for PFS: HR 1.18, 95% CI 1.11–1.21, p = 0.016; for OS: HR 1.17, 95% CI 1.14–1.19, p = 0.048) and PD-1 (for PFS: HR 1.01, 95% CI 0.91–1.06, p = 0.035). Unfavorable prognostic factors determined in peritoneal fluid were: PD-L1 (for PFS: HR 1.08, 95% CI 1.01–1.11, p = 0.049; for OS: HR 1.14, 95% CI 1.10–1.17, p = 0.045) and PD-1 (for PFS: HR 1.21, 95% CI 1.19–1.26, p = 0.044). We conclude that CTLA-4 should be considered as a potential biomarker in the diagnosis of ovarian cancer. PD-L1 and PD-1 concentrations are unfavorable prognostic factors for ovarian cancer.