A Paradoxical Role for Regulatory T Cells in the Tumor Microenvironment of Pancreatic Cancer

Validation of ZIP4 as a tumour-associated antigen for nanotargeting

Pancreatic ductal adenocarcinoma remains a highly aggressive and untreatable cancer. There is a need to develop a new PDAC-associated antigen-targeting drug delivery system to tackle this disease. We validated choosing ZIP4 as a putative target in PDAC theranostics. We developed a nanosystem composed of a fluorescent polystyrene core coated with gold nanoparticles onto which a ZIP4-specific polyclonal antibody is attached. The polystyrene core's fluorescence properties allow the nanosystem tracking by intravital imaging. We also developed two ZIP4-expressing cell lines by stably transfecting HEK293 and RWP1 cells with a ZIP4-coding plasmid that simultaneously provides cells with puromycin resistance. We studied the cell internalisation of the as-synthesised nanoparticles and demonstrated that ZIP4-expressing HEK293 and ZIP4-expressing RWP1 cells tended to take up more ZIP4-targeting nanoparticles. Moreover, we observed that ZIP4-targeting nanoparticles accumulated more in ZIP4-expressing HEK293 and RWP1 tumours when injected intravenously in a subcutaneous xenograft and an orthotopic in vivo model, respectively. Furthermore, the administration of these nanoparticles did not induce any significant systemic toxicity as determined by histological analysis of all organs. Altogether, these results provide the first evidence of the feasibility of using a ZIP4-targeting nanosystem further to design efficient therapeutic and diagnostic tools for PDAC.

The Immunomodulatory Role of Vitamin D in Regulating the Th17/Treg Balance and Epithelial-Mesenchymal Transition: A Hypothesis for Gallbladder Cancer

The etiology of gallbladder cancer (GBC) is multifactorial, with chronic inflammation resulting from infections, autoimmune diseases, and lifestyle factors playing a pivotal role. Vitamin D deficiency (VDD) has been implicated in the pathogenesis of autoimmune disorders and various malignancies, including GBC. Research on autoimmune diseases highlights the anti-inflammatory properties of vitamin D, suggesting its potential to mitigate disease progression. In oncology, VDD has similarly been linked to increased inflammation, which may contribute to both the initiation and progression of cancer. A critical component in carcinogenesis, as well as in the immunomodulatory effects of vitamin D in autoimmune conditions, is the balance between T-helper 17 (Th17) cells and regulatory T (Treg) cells. We hypothesize that vitamin D may inhibit epithelial-mesenchymal transition (EMT) in GBC by modulating the spatial distribution of tumor-infiltrating T cells, particularly through the regulation of the Th17/Treg balance at the tumor margins. This Th17/Treg imbalance may act as a mechanistic link between VDD and the progression of GBC carcinogenesis. Investigating the role of an Th17/Treg imbalance as a mediator in VDD-induced EMT in GBC not only provides deeper insights into the pathogenesis of GBC but also sheds light on broader mechanisms relevant to the development of other solid organ cancers, given the expanding recognition of the roles of VDD and Th17/Treg cells in cancer biology.

Prognostic value of tumor-infiltrating lymphocytes and PD-L1 expression in esophageal squamous cell carcinoma

BACKGROUND

Tumor cells (TC) participate in tumor progression by altering the immune responses in the tumor microenvironment. However, the clinical relevance and prognostic effect of PD-L1 expression and tumor-infiltrating lymphocytes (TILs) in esophageal squamous cell carcinoma (ESCC) are unknown. The purpose of this study was to investigate the interactions and clinical significance of PD-L1 expression and TILs in ESCC.

METHODS

Tissue specimens were collected from 126 patients with ESCC who underwent curative esophagectomy. Immunohistochemical analysis and multiplex immunofluorescence for CD4, CD8, CD25, FOXP3, and PD-L1 in the tumor were used to identify multiple tumor-infiltrating immune cells (TIIC), Tregs, and TC.

RESULTS

PD-L1 was expressed in tumor cells (PD-L1 TC). PD-L1 TIIC and PD-L1 TC affected the biological behavior of TC. The positive expression rate of PD-L1 TC and CD8+ TILs was 27.8% (35/126) and 31.7% (40/126), respectively. Kaplan-Meier analysis showed that overall survival (OS) was significantly associated with decreased CD8+ TILs and PD-L1 TC-positive expression, which promote ESCC progression and metastasis.

CONCLUSION

Tumor depth, CD8, and PD-L1 TC were independent prognostic factors in ESCC, and a predictive nomogram with these three risk factors improved the accuracy of predicting OS in patients with ESCC after surgical resection. The conjoint analysis of multiple immune-related factors is beneficial for stratifying patient survival risk.

The Current Landscape of Clinical Trials for Immunotherapy in Pancreatic Cancer: A State-of-the-Art Review

BACKGROUND

Pancreatic cancer remains a lethal malignancy with a 5-year survival rate below 6% and about 500,000 deaths annually worldwide. Pancreatic adenocarcinoma, the most prevalent form, is commonly associated with diabetes, chronic pancreatitis, obesity, and smoking, mainly affecting individuals aged 60 to 80 years. This systematic review aims to evaluate the efficacy of immunotherapeutic approaches in the treatment of pancreatic cancer.

METHODS

A systematic search was conducted to identify clinical trials (Phases I-III) assessing immunotherapy in pancreatic cancer in PubMed/Medline, CINAHL, Scopus, and Web of Science, adhering to PRISMA Statement 2020 guidelines. The final search was completed on May 25, 2024. Ongoing trials were sourced from ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform (ICTRP). Keywords such as "pancreatic," "immunotherapy," "cancer," and "clinical trial" were used across databases. Gray literature was excluded.

RESULTS

Phase I trials, involving 337 patients, reported a median overall survival (OS) of 13.6 months (IQR: 5-62.5 months) and a median progression-free survival (PFS) of 5.1 months (IQR: 1.9-11.7 months). Phase II/III trials pooled in a total of 1463 participants had a median OS of 12.2 months (IQR: 2.5-35.55 months) and a median PFS of 8.8 months (IQR: 1.4-33.51 months).

CONCLUSIONS

Immunotherapy shows potential for extending survival among pancreatic cancer patients, though results vary. The immunosuppressive nature of the tumor microenvironment and diverse patient responses underline the need for further research to optimize these therapeutic strategies.

Multimodal analysis unveils tumor microenvironment heterogeneity linked to immune activity and evasion

The cellular and molecular heterogeneity of tumors is a major obstacle to cancer immunotherapy. Here, we use a systems biology approach to derive a signature of the main sources of heterogeneity in the tumor microenvironment (TME) from lung cancer transcriptomics. We demonstrate that this signature, which we called iHet, is conserved in different cancers and associated with antitumor immunity. Through analysis of single-cell and spatial transcriptomics data, we trace back the cellular origin of the variability explaining the iHet signature. Finally, we demonstrate that iHet has predictive value for cancer immunotherapy, which can be further improved by disentangling three major determinants of anticancer immune responses: activity of immune cells, immune infiltration or exclusion, and cancer-cell foreignness. This work shows how transcriptomics data can be integrated to derive a holistic representation of the phenotypic heterogeneity of the TME and to predict its unfolding and fate during immunotherapy with immune checkpoint blockers.

Targeted Therapy for Highly Desmoplastic and Immunosuppressive Tumor Microenvironment of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a very poor prognosis. Despite advancements in treatment strategies, PDAC remains recalcitrant to therapies because patients are often diagnosed at an advanced stage. The advanced stage of PDAC is characterized by metastasis, which typically renders it unresectable by surgery or untreatable by chemotherapy. The tumor microenvironment (TME) of PDAC comprises highly proliferative myofibroblast-like cells and hosts the intense deposition of a extracellular matrix component that forms dense fibrous connective tissue, a process called the desmoplastic reaction. In desmoplastic TMEs, the incessant aberration of signaling pathways contributes to immunosuppression by suppressing antitumor immunity. This feature offers a protective barrier that impedes the targeted delivery of drugs. In addition, the efficacy of immunotherapy is compromised because of the immune cold TME of PDAC. Targeted therapy approaches towards stromal and immunosuppressive TMEs are challenging. In this review, we discuss cellular and non-cellular TME components that contain actionable targets for drug development. We also highlight findings from preclinical studies and provide updates about the efficacies of new investigational drugs in clinical trials.

Unveiling the immunosuppressive landscape of pancreatic ductal adenocarcinoma: implications for innovative immunotherapy strategies

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), stands as the fourth leading cause of cancer-related deaths in the United States, marked by challenging treatment and dismal prognoses. As immunotherapy emerges as a promising avenue for mitigating PDAC's malignant progression, a comprehensive understanding of the tumor's immunosuppressive characteristics becomes imperative. This paper systematically delves into the intricate immunosuppressive network within PDAC, spotlighting the significant crosstalk between immunosuppressive cells and factors in the hypoxic acidic pancreatic tumor microenvironment. By elucidating these mechanisms, we aim to provide insights into potential immunotherapy strategies and treatment targets, laying the groundwork for future studies on PDAC immunosuppression. Recognizing the profound impact of immunosuppression on PDAC invasion and metastasis, this discussion aims to catalyze the development of more effective and targeted immunotherapies for PDAC patients.

Potential anti-tumor effects of regulatory T cells in the tumor microenvironment: a review

Regulatory T cells (Tregs) expressing the transcription factor FoxP3 are essential for maintaining immunological balance and are a significant component of the immunosuppressive tumor microenvironment (TME). Single-cell RNA sequencing (ScRNA-seq) technology has shown that Tregs exhibit significant plasticity and functional diversity in various tumors within the TME. This results in Tregs playing a dual role in the TME, which is not always centered around supporting tumor progression as typically believed. Abundant data confirms the anti-tumor activities of Tregs and their correlation with enhanced patient prognosis in specific types of malignancies. In this review, we summarize the potential anti-tumor actions of Tregs, including suppressing tumor-promoting inflammatory responses and boosting anti-tumor immunity. In addition, this study outlines the spatial and temporal variations in Tregs function to emphasize that their predictive significance in malignancies may change. It is essential to comprehend the functional diversity and potential anti-tumor effects of Tregs to improve tumor therapy strategies.

Intratumoral T-cell receptor repertoire composition predicts overall survival in patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy that is refractory to immune checkpoint inhibitor therapy. However, intratumoral T-cell infiltration correlates with improved overall survival (OS). Herein, we characterized the diversity and antigen specificity of the PDAC T-cell receptor (TCR) repertoire to identify novel immune-relevant biomarkers. Demographic, clinical, and TCR-beta sequencing data were collated from 353 patients across three cohorts that underwent surgical resection for PDAC. TCR diversity was calculated using Shannon Wiener index, Inverse Simpson index, and "True entropy." Patients were clustered by shared repertoire specificity. TCRs predictive of OS were identified and their associated transcriptional states were characterized by single-cell RNAseq. In multivariate Cox regression models controlling for relevant covariates, high intratumoral TCR diversity predicted OS across multiple cohorts. Conversely, in peripheral blood, high abundance of T-cells, but not high diversity, predicted OS. Clustering patients based on TCR specificity revealed a subset of TCRs that predicts OS. Interestingly, these TCR sequences were more likely to encode CD8+ effector memory and CD4+ T-regulatory (Tregs) T-cells, all with the capacity to recognize beta islet-derived autoantigens. As opposed to T-cell abundance, intratumoral TCR diversity was predictive of OS in multiple PDAC cohorts, and a subset of TCRs enriched in high-diversity patients independently correlated with OS. These findings emphasize the importance of evaluating peripheral and intratumoral TCR repertoires as distinct and relevant biomarkers in PDAC.

An Update on Gemcitabine-Based Chemosensitization Strategies in Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is the seventh leading cause of cancer-related deaths, and chemotherapy is one of the most important treatments for pancreatic cancer. Unfortunately, pancreatic cancer cells can block chemotherapy drugs from entering the tumor. This is owing to interactions between the tumor's environment and the cancer cells. Here, we review the latest research on the mechanisms by which pancreatic cancer cells block the chemotherapy drug, gemcitabine. The results of our review can help identify potential therapeutic targets for the blocking of gemcitabine by pancreatic cancer cells and may provide new strategies to help chemotherapy drugs penetrate tumors.

Targeting KRASG12V mutations with HLA class II-restricted TCR for the immunotherapy in solid tumors

KRAS mutation is a significant driving factor of tumor, and KRAS^G12V mutation has the highest incidence in solid tumors such as pancreatic cancer and colorectal cancer. Thus, KRAS^G12V neoantigen-specific TCR-engineered T cells could be a promising cancer treatment approach for pancreatic cancer. Previous studies had reported that KRAS^G12V-reactive TCRs originated from patients' TILs could recognized KRAS^G12V neoantigen presented by specific HLA subtypes and remove tumor persistently in vitro and in vivo. However, TCR drugs are different from antibody drugs in that they are HLA-restricted. The different ethnic distribution of HLA greatly limits the applicability of TCR drugs in Chinese population. In this study, we have identified a KRAS^G12V-specific TCR which recognized classII MHC from a colorectal cancer patient. Interestingly, we observed that KRAS^G12V-specific TCR-engineered CD4⁺ T cells, not CD8⁺ T cells, demonstrated significant efficacy in vitro and in xenograft mouse model, exhibiting stable expression and targeting specificity of TCR when co-cultured with APCs presenting KRAS^G12V peptides. TCR-engineered CD4⁺ T cells were co-cultured with APCs loaded with neoantigen, and then HLA subtypes were identified by the secretion of IFN-γ. Collectively, our data suggest that TCR-engineered CD4⁺ T cells can be used to target KRAS^G12V mutation presented by HLA-DPB1*03:01 and DPB1*14:01, which provide a high population coverage and are more suitable for the clinical transformation for Chinese, and mediate tumor killing effect like CD8⁺ T cells. This TCR hold promise for precision therapy in immunotherapy of solid tumors as an attractive candidate.

Prognostic and recurrent significance of SII in patients with pancreatic head cancer undergoing pancreaticoduodenectomy

BACKGROUND

To investigate the clinical significance of preoperative inflammatory status in patients with pancreatic head carcinoma (PHC), we performed a single-center study to assess it.

METHOD

We studied a total of 164 patients with PHC undergoing PD surgery (with or without allogeneic venous replacement) from January 2018 to April 2022. Systemic immune-inflammation index (SII) was the most important peripheral immune index in predicting the prognosis according to XGBoost analysis. The optimal cutoff value of SII for OS was calculated according to Youden index based on the receiver operating characteristic (ROC) curve and the cohort was divided into Low SII group and High SII group. Demographic, clinical data, laboratory data, follow-up data variables were obtained and compared between the two groups. Kaplan-Meier curves, univariable and multivariable Cox regression models were used to determine the association between preoperative inflammation index, nutritional index and TNM staging system with OS and DFS respectively.

RESULTS

The median follow-up time was 16 months (IQR 23), and 41.4% of recurrences occurred within 1 year. The cutoff value of SII was 563, with a sensitivity of 70.3%, and a specificity of 60.7%. Peripheral immune status was different between the two groups. Patients in High SII group had higher PAR, NLR than those in Low SII group (P <0.01, <0.01, respectively), and lower PNI (P <0.01). Kaplan-Meier analysis showed significantly poorer OS and DFS (P < 0.001, <0.001, respectively) in patients with high SII. By using the multivariable Cox regression model, high SII (HR, 2.056; 95% CI, 1.082-3.905, P=0.028) was significant predictor of OS. Of these 68 high-risk patients who recurrence within one year, patients with widespread metastasis had lower SII and worse prognosis (P <0.01).

CONCLUSION

High SII was significantly associated with poor prognosis in patients with PHC. However, in patients who recurrence within one year, SII was lower in patients at TNM stage III. Thus, care needs to be taken to differentiate those high-risk patients.

Immune-related pan-cancer gene expression signatures of patient survival revealed by NanoString-based analyses

The immune system plays a central role in the onset and progression of cancer. A better understanding of transcriptional changes in immune cell-related genes associated with cancer progression, and their significance in disease prognosis, is therefore needed. NanoString-based targeted gene expression profiling has advantages for deployment in a clinical setting over RNA-seq technologies. We analysed NanoString PanCancer Immune Profiling panel gene expression data encompassing 770 genes, and overall survival data, from multiple previous studies covering 10 different cancer types, including solid and blood malignancies, across 515 patients. This analysis revealed an immune gene signature comprising 39 genes that were upregulated in those patients with shorter overall survival; of these 39 genes, three (MAGEC2, SSX1 and ULBP2) were common to both solid and blood malignancies. Most of the genes identified have previously been reported as relevant in one or more cancer types. Using Cibersort, we investigated immune cell levels within individual cancer types and across groups of cancers, as well as in shorter and longer overall survival groups. Patients with shorter survival had a higher proportion of M2 macrophages and γδ T cells. Patients with longer overall survival had a higher proportion of CD8+ T cells, CD4+ T memory cells, NK cells and, unexpectedly, T regulatory cells. Using a transcriptomics platform with certain advantages for deployment in a clinical setting, our multi-cancer meta-analysis of immune gene expression and overall survival data has identified a specific transcriptional profile associated with poor overall survival.