CD25 and TGF-β blockade based on predictive integrated immune ratio inhibits tumor growth in pancreatic cancer

Emerging Trends in Gastrointestinal Cancer Targeted Therapies: Harnessing Tumor Microenvironment, Immune Factors, and Metabolomics Insights

Gastrointestinal (GI) cancers are the leading cause of new cancer cases and cancer-related deaths worldwide. The treatment strategies for patients with GI tumors have focused on oncogenic molecular profiles associated with tumor cells. Recent evidence has demonstrated that the tumor cell functions are modulated by its microenvironment, compromising fibroblasts, extracellular matrices, microbiome, immune cells, and the enteric nervous system. Along with the tumor microenvironment components, alterations in key metabolic pathways have emerged as a hallmark of tumor cells. From these perspectives, this review will highlight the functions of different cellular components of the GI tumor microenvironment and their implications for treatment. Furthermore, we discuss the major metabolic reprogramming in GI tumor cells and how understanding metabolic rewiring could lead to new therapeutic strategies. Finally, we briefly summarize the targeted agents currently being studied in GI cancers. Understanding the complex interplay between tumor cell-intrinsic and -extrinsic factors during tumor progression is critical for developing new therapeutic strategies.

Tumor Stroma as a Therapeutic Target for Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis owing to its desmoplastic stroma. Therefore, therapeutic strategies targeting this tumor stroma should be developed. In this study, we describe the heterogeneity of cancer-associated fibroblasts (CAFs) and their diverse roles in the progression, immune evasion, and resistance to treatment of PDAC. We subclassified the spatial distribution and functional activity of CAFs to highlight their effects on prognosis and drug delivery. Extracellular matrix components such as collagen and hyaluronan are described for their roles in tumor behavior and treatment outcomes, implying their potential as therapeutic targets. We also discussed the roles of extracellular matrix (ECM) including matrix metalloproteinases and tissue inhibitors in PDAC progression. Finally, we explored the role of the adaptive and innate immune systems in shaping the PDAC microenvironment and potential therapeutic strategies, with a focus on immune cell subsets, cytokines, and immunosuppressive mechanisms. These insights provide a comprehensive understanding of PDAC and pave the way for the development of prognostic markers and therapeutic interventions.

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.

Poor clinical outcomes and immunoevasive contexture in CD161+CD8+ T cells barren human pancreatic cancer

BACKGROUND

The role of CD161 expression on CD8+ T cells in tumor immunology has been explored in a few studies, and the clinical significance of CD161+CD8+ T cells in pancreatic ductal adenocarcinoma (PDAC) remains unclear. This study seeks to clarify the prognostic value and molecular characteristics linked to CD161+CD8+ T cell infiltration in PDAC.

METHODS

This study included 186 patients with confirmed PDAC histology after radical resection. CD161+CD8+ T cell infiltration was assessed using immunofluorescence staining on tumor microarrays. Flow cytometry and single-cell RNA sequencing were used to evaluate their functional status.

RESULTS

We observed significant associations between tumor-infiltrating CD161+CD8+ T cells and clinicopathological factors, such as tumor differentiation, perineural invasion, and serum CA19-9 levels. Patients with higher tumor-infiltrating CD161+CD8+ T cell levels had longer overall survival (OS) and recurrence-free survival (RFS) than those with lower levels. Multivariable analysis confirmed tumor-infiltrating CD161+CD8+ T cell as an independent prognostic indicator for both OS and RFS. Notably, a combination of tumor-infiltrating CD161+CD8+ T cell and CA19-9 levels showed a superior power for survival prediction, and patients with low tumor-infiltrating CD161+CD8+ T cell and high CA19-9 levels had the worst survival. Furthermore, lower tumor-infiltrating CD161+CD8+ T cells were associated with a better response to adjuvant chemotherapy. Finally, we identified tumor-infiltrating CD161+CD8+ T cells as a unique subtype of responsive CD8+ T cells characterized by increased levels of cytotoxic cytokines and immune checkpoint molecules.

CONCLUSION

CD161+CD8+ T cells exhibit elevated levels of both cytotoxic and immune-checkpoint molecules, indicating as a potential and attractive target for immunotherapy. The tumor-infiltrating CD161+CD8+ T cell is a valuable and promising predictor for survival and therapeutic response to adjuvant chemotherapy in PDAC. Further research is warranted to validate its role in the risk stratification and optimization of therapeutic strategies.

Advances in Immunotherapeutics in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) accounts for up to 95% of all pancreatic cancer cases and is the seventh-leading cause of cancer death. Poor prognosis is a result of late presentation, a lack of screening tests and the fact some patients develop resistance to chemotherapy and radiotherapy. Novel therapies like immunotherapeutics have been of recent interest in pancreatic cancer. However, this field remains in its infancy with much to unravel. Immunotherapy and other targeted therapies have yet to yield significant progress in treating PDAC, primarily due to our limited understanding of the disease immune mechanisms and its intricate interactions with the tumour microenvironment (TME). In this review we provide an overview of current novel immunotherapies which have been studied in the field of pancreatic cancer. We discuss their mechanisms, evidence available in pancreatic cancer as well as the limitations of such therapies. We showcase the potential role of combining novel therapies in PDAC, postulate their potential clinical implications and the hurdles associated with their use in PDAC. Therapies discussed with include programmed death checkpoint inhibitors, Cytotoxic T-lymphocyte-associated protein 4, Chimeric Antigen Receptor-T cell therapy, oncolytic viral therapy and vaccine therapies including KRAS vaccines, Telomerase vaccines, Gastrin Vaccines, Survivin-targeting vaccines, Heat-shock protein (HSP) peptide complex-based vaccines, MUC-1 targeting vaccines, Listeria based vaccines and Dendritic cell-based vaccines.

Molecular and metabolic regulation of immunosuppression in metastatic pancreatic ductal adenocarcinoma

Immunosuppression is a hallmark of pancreatic ductal adenocarcinoma (PDAC), contributing to early metastasis and poor patient survival. Compared to the localized tumors, current standard-of-care therapies have failed to improve the survival of patients with metastatic PDAC, that necessecitates exploration of novel therapeutic approaches. While immunotherapies such as immune checkpoint blockade (ICB) and therapeutic vaccines have emerged as promising treatment modalities in certain cancers, limited responses have been achieved in PDAC. Therefore, specific mechanisms regulating the poor response to immunotherapy must be explored. The immunosuppressive microenvironment driven by oncogenic mutations, tumor secretome, non-coding RNAs, and tumor microbiome persists throughout PDAC progression, allowing neoplastic cells to grow locally and metastasize distantly. The metastatic cells escaping the host immune surveillance are unique in molecular, immunological, and metabolic characteristics. Following chemokine and exosomal guidance, these cells metastasize to the organ-specific pre-metastatic niches (PMNs) constituted by local resident cells, stromal fibroblasts, and suppressive immune cells, such as the metastasis-associated macrophages, neutrophils, and myeloid-derived suppressor cells. The metastatic immune microenvironment differs from primary tumors in stromal and immune cell composition, functionality, and metabolism. Thus far, multiple molecular and metabolic pathways, distinct from primary tumors, have been identified that dampen immune effector functions, confounding the immunotherapy response in metastatic PDAC. This review describes major immunoregulatory pathways that contribute to the metastatic progression and limit immunotherapy outcomes in PDAC. Overall, we highlight the therapeutic vulnerabilities attributable to immunosuppressive factors and discuss whether targeting these molecular and immunological "hot spots" could improve the outcomes of PDAC immunotherapies.

Prognostic value of tumor-associated N1/N2 neutrophil plasticity in patients following radical resection of pancreas ductal adenocarcinoma

BACKGROUND

As an integral part of the tumor microenvironment (TME), tumor-associated neutrophils play a crucial role in tumor development. The objective of this study was to investigate the plasticity of tumor-associated N1 and N2 neutrophils in the TME of pancreatic ductal adenocarcinoma (PDAC), along with its impact on survival and association with immune infiltrations.

METHODS

The primary and validation cohorts including 90 radical resection patients from September 2012 to May 2016 and 29 radical resection patients from September 2018 to October 2019, respectively, with complete survival data, were enrolled. Immunofluorescence staining was used to identify tumor-associated N1 and N2 neutrophils, and the N1/N2 ratio was used to evaluate N1 and N2 plasticity. Thereafter, the association between tumor-associated N1/N2 neutrophil plasticity, clinical features, and immune infiltrations was investigated.

RESULTS

There was a significant increase in tumor-associated N2 neutrophils compared with tumor-associated N1 neutrophils. Low N1/N2 ratios were associated with the poorer differentiation of tumors, easier lymph node metastases, and a higher TNM stage. The median overall survival (OS) and recurrence-free survival (RFS) of the high tumor-associated N1 neutrophil group were significantly longer than those of the low group, while the tumor-associated N2 neutrophils played an opposite role. The multivariable analysis revealed that a high N1/N2 ratio was a significant prognostic indicator for OS and RFS. In addition, tumor-associated N1/N2 neutrophils showed an opposite correlation with tumor-infiltrating CD8⁺ T cells and Tregs.

CONCLUSION

The plasticity of tumor-associated N1/N2 neutrophils was identified as a crucial prognostic indicator that might reflect the TME and immune escape in patients with PDAC. On further investigation and validation, our findings may be used to further stratify patients with varying prognoses to optimize treatment.

Therapeutic targeting of regulatory T cells in cancer

The success of immunotherapy in oncology underscores the vital role of the immune system in cancer development. Regulatory T cells (Tregs) maintain a fine balance between autoimmunity and immune suppression. They have multiple roles in the tumor microenvironment (TME) but act particularly in suppressing T cell activation. This review focuses on the detrimental and sometimes beneficial roles of Tregs in tumors, our current understanding of recruitment and stabilization of Tregs within the TME, and current Treg-targeted therapeutics. Research identifying subpopulations of Tregs and their respective functions and interactions within the complex networks of the TME will be crucial to develop the next generation of immunotherapies. Through these advances, Treg-targeted immunotherapy could have important implications for the future of oncology.

A study on the correlation between M2 macrophages and regulatory T cells in the progression of colorectal cancer

Background

M2 macrophages and regulatory T cells (Tregs) can promote tumors and development by inhibiting the anti-tumor immune response. This study investigated the effect of CD163-positive M2 macrophages and Foxp3-positive Tregs in the progression of colorectal cancer and lymph node metastasis. It also investigated the correlation between M2 macrophages and Tregs.

Methods

Postoperative tissue specimens and clinical data were collected from 197 patients with colorectal cancer who underwent initial surgical treatment in The Second Ward of Colorectal Surgery of the First Affiliated Hospital of Jinzhou Medical University from March 2020 to December 2020. Immunohistochemical methods were used to detect the expression levels of CD163 protein-labeled M2 macrophages and Foxp3 protein-labeled Tregs in colorectal cancer tissues, matched paracancer tissues, and lymph node tissues. The correlation between CD163 and Foxp3 in cancer tissues and lymph node tissues were analyzed, as well as the relationship between clinicopathological characteristics and preoperative tumor markers.

Results

M2 macrophages and Tregs were importantly positively correlated in cancer and lymph node tissues, which significantly increased in cancer and metastatic lymph node tissues. Interestingly, M2 macrophages in non-metastatic lymph nodes also increased significantly in patients with metastatic lymph nodes. In addition, both CD163 and Foxp3 were upregulated with increasing tumor node metastasis stage, depth of infiltration, and lymphatic metastasis; and both were positively correlated with carcinoembryonic antigen.

Conclusion

CD163 may be a good predictor of pre-metastatic status of colorectal cancer lymph nodes. carcinoembryonic antigen affects the distribution of M2 macrophages and Tregs in colorectal cancer. There is a certain correlation between the two types of cells. It is possible that M2 macrophages, together with suppressor Tregs cells, promote an immunosuppressive environment.

Advance of T regulatory cells in tumor microenvironment remodeling and immunotherapy in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive, deadly, and is rarely diagnosed early. Regulatory T cells (Treg) are a multifunctional class of immunosuppressive T cells that help maintain immunologic homeostasis and participate in autoimmune diseases, transplants, and tumors. This cell type mediates immune homeostasis, tolerance, and surveillance and is associated with poor outcomes in PDAC. Tregs remodel the tumor immune microenvironment, mediate tumor immune escape, and promote tumor invasion and metastasis. A promising area of research involves regulating Tregs to reduce their infiltration into tumor tissues. However, the complexity of the immune microenvironment has limited the efficacy of immunotherapy in PDAC. Treg modulation combined with other treatments is emerging. This review summarizes the mechanisms of Tregs activity in tumor immune microenvironments in PDAC and the latest developments in immunotherapy and clinical trials.

Identification of an Immune-Related BAT Signature for Predicting Adjuvant Chemotherapy Response and Overall Survival in Patients with Resected Ductal Adenocarcinoma of the Pancreas

BACKGROUND

Adjuvant chemotherapy (ACT) is widely accepted in patients with pancreatic ductal adenocarcinoma (PDAC) after surgery; however, effective models for predicting ACT response are scarce. Thus, the objective of this study was to develop a novel signature for predicting its response and overall survival (OS) in resected PDAC patients.

METHODS

A total of 50 PDAC patients with the transcriptome expression profiles, information about chemotherapy, and relevant clinical data were retrieved from the Cancer Genome Atlas (TCGA), and twenty-nine patients with tissue specimens and clinical data from our hospital were included as a validation. A novel gene signature was developed using bioinformatic differentially expressed genes (DEGs) analysis, Lasso-penalized Cox regression, and multivariate Cox regression studies.

RESULTS

Between chemotherapy-resistant and chemotherapy-sensitive cohorts, 569 DEGs were identified, with 490 upregulated and 79 downregulated genes mainly specialized in the regulation of peptide/protein/hormone secretion, calcium ion homeostasis, and T cell activation regulation in biological processes. After Lasso-penalized Cox and multivariate Cox regression analysis, BAT (BCHE, ADH1A, and TNS4) signature was established to predict ACT response and OS. Moreover, BAT signature was verified as an independent risk factor for ACT response (p = 0.042) and OS (median OS: 17.5 months vs. 34.8 months, p = 0.040) and significantly associated with immune infiltrations (p < 0.05). Then, this signature was further validated as the independent risk factor for recurrence-free survival (RFS) in PDAC patients receiving postoperative ACT (median RFS: 9.0 months vs. not reached, p = 0.014), and tumor-infiltrating CD4+ and CD8+ T cells were further validated to be significantly decreased in tissues with higher BAT signature scores (p = 0.015 and 0.021, respectively).

CONCLUSION

The BAT signature is a novel formulated and independent risk factor for predicting ACT response and long-term survival in patients with resected PDAC. This signature could comprehensively reflect local immune-related response, tumor purity, potential biological behavior, and chemo drug susceptibility.

The Immune Landscape of Human Pancreatic Ductal Carcinoma: Key Players, Clinical Implications, and Challenges

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and deadliest cancer worldwide with an overall survival rate, all stages combined, of still <10% at 5 years. The poor prognosis is attributed to challenges in early detection, a low opportunity for radical resection, limited response to chemotherapy, radiotherapy, and resistance to immune therapy. Moreover, pancreatic tumoral cells are surrounded by an abundant desmoplastic stroma, which is responsible for creating a mechanical barrier, preventing appropriate vascularization and leading to poor immune cell infiltration. Accumulated evidence suggests that PDAC is impaired with multiple “immune defects”, including a lack of high-quality effector cells (CD4, CD8 T cells, dendritic cells), barriers to effector cell infiltration due to that desmoplastic reaction, and a dominance of immune cells such as regulatory T cells, myeloid-derived suppressor cells, and M2 macrophages, resulting in an immunosuppressive tumor microenvironment (TME). Although recent studies have brought new insights into PDAC immune TME, its understanding remains not fully elucidated. Further studies are required for a better understanding of human PDAC immune TME, which might help to develop potent new therapeutic strategies by correcting these immune defects with the hope to unlock the resistance to (immune) therapy. In this review, we describe the main effector immune cells and immunosuppressive actors involved in human PDAC TME, as well as their implications as potential biomarkers and therapeutic targets.

Enhancer RNA LINC00242-Induced Expression of PHF10 Drives a Better Prognosis in Pancreatic Adenocarcinoma

Enhancer RNA is a kind of non-coding RNA, which is transcribed from the enhancer region of gene and plays an important role in gene transcription regulation. However, the role of eRNA in pancreatic adenocarcinoma (PAAD) is still unclear. In this study, we identified the key eRNA and its target gene in PAAD. The transcriptome data and clinical information of pancreatic cancer were downloaded from the UCSC Xena platform. A total of 2,695 eRNAs and its target gene predicted by the PreSTIGE method were selected as candidate eRNA–target pairs. After survival analysis, we found that LINC00242 was the eRNA most related to patients’ survival, and correlation analysis further indicated that LINC00242 and its target gene PHF10 had a significant co-expression relationship. Downregulation of LINC00242 was significantly associated with unfavorable clinicopathological features. Based on pan-cancer analysis, we found that LINC00242 was associated with the survival of multiple cancers, and LINC00242 was co-expressed with its target genes in multiple cancer types. External experiments further demonstrated that PHF10 was the downstream target gene of LINC00242. After ssGSEA analysis, PAAD patients were classified as high, medium, and low immune cell infiltration clusters. Compared with the low and medium immune infiltration clusters, the expression level of PHF10 was significantly upregulated in the high immune infiltration clusters. After performing the CIBERSORT algorithm, we found that there was a significant difference in the abundance of immune infiltrating cells between the PHF10 high- and low-expression groups. Additionally, the web tool TIMER was used to detect the distribution and expression of PHF10 in pan-cancer.

Prediction of anti-CD25 and 5-FU treatments efficacy for pancreatic cancer using a mathematical model

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with rising incidence and with 5-years overall survival of less than 8%. PDAC creates an immune-suppressive tumor microenvironment to escape immune-mediated eradication. Regulatory T (Treg) cells and myeloid-derived suppressor cells (MDSC) are critical components of the immune-suppressive tumor microenvironment. Shifting from tumor escape or tolerance to elimination is the major challenge in the treatment of PDAC.

RESULTS

In a mathematical model, we combine distinct treatment modalities for PDAC, including 5-FU chemotherapy and anti- CD25 immunotherapy to improve clinical outcome and therapeutic efficacy. To address and optimize 5-FU and anti- CD25 treatment (to suppress MDSCs and Tregs, respectively) schedule in-silico and simultaneously unravel the processes driving therapeutic responses, we designed an in vivo calibrated mathematical model of tumor-immune system (TIS) interactions. We designed a user-friendly graphical user interface (GUI) unit which is configurable for treatment timings to implement an in-silico clinical trial to test different timings of both 5-FU and anti- CD25 therapies. By optimizing combination regimens, we improved treatment efficacy. In-silico assessment of 5-FU and anti- CD25 combination therapy for PDAC significantly showed better treatment outcomes when compared to 5-FU and anti- CD25 therapies separately. Due to imprecise, missing, or incomplete experimental data, the kinetic parameters of the TIS model are uncertain that this can be captured by the fuzzy theorem. We have predicted the uncertainty band of cell/cytokines dynamics based on the parametric uncertainty, and we have shown the effect of the treatments on the displacement of the uncertainty band of the cells/cytokines. We performed global sensitivity analysis methods to identify the most influential kinetic parameters and simulate the effect of the perturbation on kinetic parameters on the dynamics of cells/cytokines.

CONCLUSION

Our findings outline a rational approach to therapy optimization with meaningful consequences for how we effectively design treatment schedules (timing) to maximize their success, and how we treat PDAC with combined 5-FU and anti- CD25 therapies. Our data revealed that a synergistic combinatorial regimen targeting the Tregs and MDSCs in both crisp and fuzzy settings of model parameters can lead to tumor eradication.

TGFβ Signaling in the Pancreatic Tumor Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor clinical outcomes, largely attributed to incomplete responses to standard therapeutic approaches. Recently, selective inhibitors of the Transforming Growth Factor β (TGFβ) signaling pathway have shown early promise in the treatment of PDAC, particularly as a means of augmenting responses to chemo- and immunotherapies. However, TGFβ is a potent and pleiotropic cytokine with several seemingly paradoxical roles within the pancreatic tumor microenvironment (TME). Although TGFβ signaling can have potent tumor-suppressive effects in epithelial cells, TGFβ signaling also accelerates pancreatic tumorigenesis by enhancing epithelial-to-mesenchymal transition (EMT), fibrosis, and the evasion of the cytotoxic immune surveillance program. Here, we discuss the known roles of TGFβ signaling in pancreatic carcinogenesis, the biologic consequences of the genetic inactivation of select components of the TGFβ pathway, as well as past and present attempts to advance TGFβ inhibitors in the treatment of PDAC patients.

A metabolism-relevant signature as a predictor for prognosis and therapeutic response in pancreatic cancer

Although several altered metabolic genes have been identified to be involved in the tumorigenesis and advance of pancreatic cancer (PC), their prognostic values remained unclear. The purpose of this study was to explore new targets and establish a metabolic signature to predict prognosis and chemotherapy response for optimal individualized treatment. The expression data of PC patients from two independent cohorts and metabolism-related genes from KEGG were utilized and analyzed for the establishment of the signature via lasso regression. Then, the differentially expressed candidate genes were further confirmed via online data mining platform and qRT-PCR of clinical specimens. Then, the analyses of gene set enrichment, mutation, and chemotherapeutic response were performed via R package. As results showed, 109 differentially expressed metabolic genes were screened out in PC. Then a metabolism-related five-gene signature comprising B3GNT3, BCAT1, KYNU, LDHA, and TYMS was constructed and showed excellent ability for predicting survival. A novel nomogram coordinating the metabolic signature and other independent prognostic parameters was developed and showed better predictive power in predicting survival. In addition, this metabolic signature was significantly involved in the activation of multiple oncological pathways and regulation of the tumor immune microenvironment. The patients with high risk scores had higher tumor mutation burdens and were prone to be more sensitive to chemotherapy. In summary, our work identified a new metabolic signature and established a superior prognostic nomogram which may supply more indications to explore novel strategies for diagnosis and treatment.

Lymph Node Metastatic Patterns and Survival Predictors Based on Tumor Size in Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Larger tumor size is widely acknowledged to be associated with increased lymph node (LN) metastatic potential. However, the quantitative relationships between tumor size and LN metastasis or survival remain unclear. This study aims to quantify the objective relationship between tumor size and the prevalence of LN metastases across a spectrum primary tumor size.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 9958 patients with resected PDAC without distant metastasis. The prevalence of LN metastases, LN ratio (LNR), and N2/N1 ratio were assessed amongst different tumor sizes, and the relationships were displayed by matched curves.

RESULTS

In the enrolled cohort, age, tumor site, grade, American Joint Committee on Cancer (AJCC) 8th node staging, tumor size, chemotherapy, and radiotherapy were identified as significant independent predictors for overall survival (OS) and cancer-specific survival (CSS). For tumors within 1-40 mm in size, the prevalence of node-positive disease is closely modelled using a logarithmic formula [0.249 × ln (size) + 0.452] × 100%. The prevalence plateaued between 70% and 80% beyond 40 mm. The mean LNR increased in a stepwise manner as tumor size increased from 1-5 mm (LNR = 0.024) to 41-45 mm (LNR = 0.177); then, beyond 45 mm, it plateaued near 0.170. N2/N1 ratio gradually increased along with tumor size from 1-5 mm (N2/N1 = 0.286) to 41-45 mm (N2/N1 = 1.016), and when tumor size reached to 41-45 mm or more, the ratio stabilized around 1.000. In addition, significant survival prediction by AJCC N staging was observed when tumors ranging between 16 and 45 mm in size.

CONCLUSION

Regional LN involvement demonstrated a logarithmic growth with increasing tumor sizes in patients with resected PDAC . The probability of metastasis in each regional LN for resected PDAC with tumors greater than 40 mm in size was near 17.0% and their overall prevalence of LN metastasis was 70-80%. Among which, 50% of patients had an N2 stage. Such prediction may be a potential and promising tool for guiding lymphadenectomy in PDAC surgery.

Modeling pancreatic cancer in mice for experimental therapeutics

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy that is characterized by early metastasis, low resectability, high recurrence, and therapy resistance. The experimental mouse models have played a central role in understanding the pathobiology of PDAC and in the preclinical evaluation of various therapeutic modalities. Different mouse models with targetable pathological hallmarks have been developed and employed to address the unique challenges associated with PDAC progression, metastasis, and stromal heterogeneity. Over the years, mouse models have evolved from simple cell line-based heterotopic and orthotopic xenografts in immunocompromised mice to more complex and realistic genetically engineered mouse models (GEMMs) involving multi-gene manipulations. The GEMMs, mostly driven by KRAS mutation(s), have been widely accepted for therapeutic optimization due to their high penetrance and ability to recapitulate the histological, molecular, and pathological hallmarks of human PDAC, including comparable precursor lesions, extensive metastasis, desmoplasia, perineural invasion, and immunosuppressive tumor microenvironment. Advanced GEMMs modified to express fluorescent proteins have allowed cell lineage tracing to provide novel insights and a new understanding about the origin and contribution of various cell types in PDAC pathobiology. The syngeneic mouse models, GEMMs, and target-specific transgenic mice have been extensively used to evaluate immunotherapies and study therapy-induced immune modulation in PDAC yielding meaningful results to guide various clinical trials. The emerging mouse models for parabiosis, hepatic metastasis, cachexia, and image-guided implantation, are increasingly appreciated for their high translational significance. In this article, we describe the contribution of various experimental mouse models to the current understanding of PDAC pathobiology and their utility in evaluating and optimizing therapeutic modalities for this lethal malignancy.

Defining a minimum number of examined lymph nodes improves the prognostic value of lymphadenectomy in pancreas ductal adenocarcinoma

BACKGROUND

Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy.

METHODS

Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines.

RESULTS

As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage.

CONCLUSION

This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.

Safety and activity of the TGFβ receptor I kinase inhibitor galunisertib plus the anti-PD-L1 antibody durvalumab in metastatic pancreatic cancer

Background

We assessed the safety, efficacy, and pharmacokinetics of the transforming growth factor beta (TGFβ) receptor inhibitor galunisertib co-administered with the anti-programmed death-ligand 1 (PD-L1) antibody durvalumab in recurrent/refractory metastatic pancreatic cancer previously treated with ≤2 systemic regimens.

Methods

This was a two-part, single-arm, multinational, phase Ib study. In a dose-finding phase, escalating oral doses of galunisertib were co-administered on days 1–14 with fixed-dose intravenous durvalumab 1500 mg on day 1 every 4 weeks (Q4W), followed by an expansion cohort phase.

Results

The galunisertib recommended phase II dose (RP2D) when co-administered with durvalumab 1500 mg Q4W was 150 mg two times per day. No dose-limiting toxicities were recorded. Among 32 patients treated with galunisertib RP2D, 1 patient had partial response, 7 had stable disease, 15 had objective progressive disease, and 9 were not evaluable. Disease control rate was 25.0%. Median overall survival and progression-free survival were 5.72 months (95% CI: 4.01 to 8.38) and 1.87 months (95% CI: 1.58 to 3.09), respectively. Pharmacokinetic profiles for combination therapy were comparable to those published for each drug. There was no association between potential biomarkers and treatment outcomes.

Conclusion

Galunisertib 150 mg two times per day co-administered with durvalumab 1500 mg Q4W was tolerable. Clinical activity was limited. Studying this combination in patients in an earlier line of treatment or selected for predictive biomarkers of TGFβ inhibition might be a more suitable approach.

Trial registration number

ClinicalTrials.gov identifier: NCT02734160.

Transforming Growth Factor-β: A Multifunctional Regulator of Cancer Immunity

Transforming growth factor-β (TGF-β) was originally identified as an anti-tumour cytokine. However, there is increasing evidence that it has important roles in the tumour microenvironment (TME) in facilitating cancer progression. TGF-β actively shapes the TME via modulating the host immunity. These actions are highly cell-type specific and complicated, involving both canonical and non-canonical pathways. In this review, we systemically update how TGF-β signalling acts as a checkpoint regulator for cancer immunomodulation. A better appreciation of the underlying pathogenic mechanisms at the molecular level can lead to the discovery of novel and more effective therapeutic strategies for cancer.

Transforming Growth Factor-β: A Multifunctional Regulator of Cancer Immunity

Simple Summary

Transforming growth factor beta (TGF-β) is a multifunctional cytokine that can restrict cancer onset but also promote cancer progression at late stages of cancer. The ability of TGF-β in producing diverse and sometimes opposing effects relies on its potential to control different cellular signalling and gene expression in distinct cell types, and environmental settings. The tumour promoting role of TGF-β is primarily mediated through its effects on the local tumour microenvironment (TME) of the cancer cells. In this review, we discuss the most recent research on the role and regulation of TGF-β, with a specific focus on its functions on promoting cancer progression through targeting different immune cells in the TME as well as its therapeutic perspectives.

Abstract

Transforming growth factor-β (TGF-β) was originally identified as an anti-tumour cytokine. However, there is increasing evidence that it has important roles in the tumour microenvironment (TME) in facilitating cancer progression. TGF-β actively shapes the TME via modulating the host immunity. These actions are highly cell-type specific and complicated, involving both canonical and non-canonical pathways. In this review, we systemically update how TGF-β signalling acts as a checkpoint regulator for cancer immunomodulation. A better appreciation of the underlying pathogenic mechanisms at the molecular level can lead to the discovery of novel and more effective therapeutic strategies for cancer.

Molecular Markers of Regulatory T Cells in Cancer Immunotherapy with Special Focus on Acute Myeloid Leukemia (AML) - A Systematic Review

The next-generation immunotherapy can only be effective if researchers have an in-depth understanding of the function and regulation of Treg cells in antitumor immunity combined with the discovery of new immunity targets. This can enhance clinical efficacy of future and novel therapies and reduces any adverse reactions arising from the latter. This review discusses tumor treatment strategies using regulatory T (Treg) cell therapy in a Tumor Microenvironment (TME). It also discusses factors affecting TME instability as well as relevant treatments to prevent future immune disorders. It is prognosticated that PD-1 inhibitors are risky and their adverse effects should be taken into account when they are administered to treat Acute Myeloid Leukemia (AML), lung adenocarcinoma, and prostate adenocarcinoma. In contrast, Treg molecular markers FoxP3 and CD25 analyzed here have stronger expression in almost all kinds of cancers compared with normal people. However, CD25 inhibitors are more effective compared to FoxP3 inhibitors, especially in combination with TGF-β blockade, in predicting patient survival. According to the data obtained from the Cancer Genome Atlas, we then concentrate on AML immunotherapy and discuss different therapeutic strategies including anti-CD25/IL-2, anti-CTLA-4, anti-IDO, antityrosine kinase receptor, and anti-PI3K therapies and highlight the recent advances and clinical achievements in AML immunotherapy. In order to prognosticate the risk and adverse effects of key target inhibitors (namely against CTLA-4, FoxP3, CD25, and PD-1), we finally analyzed and compared the Cancer Genome Atlas derived from ten common cancers. This review shows that Treg cells are strongly increased in AML and the comparative review of key markers shows that Tregbased immunotherapy is not effective for all kinds of cancer. Therefore, blocking CD25(+)FoxP3(+) Treg cells is suggested in AML more than other kinds of cancer; meanwhile, Treg markers studied in other cancers have also great lessons for AML immunotherapy.

Targeting the epigenetic regulation of antitumour immunity

Dysregulation of the epigenome drives aberrant transcriptional programmes that promote cancer onset and progression. Although defective gene regulation often affects oncogenic and tumour-suppressor networks, tumour immunogenicity and immune cells involved in antitumour responses may also be affected by epigenomic alterations. This could have important implications for the development and application of both epigenetic therapies and cancer immunotherapies, and combinations thereof. Here, we review the role of key aberrant epigenetic processes - DNA methylation and post-translational modification of histones - in tumour immunogenicity, as well as the effects of epigenetic modulation on antitumour immune cell function. We emphasize opportunities for small-molecule inhibitors of epigenetic regulators to enhance antitumour immune responses, and discuss the challenges of exploiting the complex interplay between cancer epigenetics and cancer immunology to develop treatment regimens combining epigenetic therapies with immunotherapies.

Radiofrequency ablation in combination with an mTOR inhibitor restrains pancreatic cancer growth induced by intrinsic HSP70

Background

Radiofrequency ablation (RFA) is widely used in palliative therapy of malignant cancers. Several studies have shown its applicability and safety for locally advanced pancreatic cancer (LAPC). The objective of this study was to modify the current regimen to improve its therapeutic effect.

Methods

Immune cell subtypes and related cytokines were quantified to uncover the immune pattern changes post-RFA treatment. Then, high-throughput proteome analysis was performed to identify differentially expressed proteins associated with RFA, which were further validated in in vitro and in vivo experiments. Finally, a combined therapy was tested in a murine model to observe its therapeutic effect.

Results

In preclinical murine models of RFA treatment, no significant therapeutic benefit was observed following RFA treatment. However, the proportion of tumor-infiltrating CD8⁺ T cells was significantly increased, whereas that of regulatory T cells (Tregs) was decreased post-RFA treatment, which indicated a beneficial anti-tumor environment. To identify the mechanism, high-throughput mass spectrum was obtained that identified heat shock protein 70 (HSP70) as the top differentially expressed protein. HSP70 expression in residual cancer cells was significantly increased post-RFA treatment, which notably promoted pancreatic cancer growth. Elevated HSP70 promoted cell proliferation by activating AKT-mTOR signaling. Finally, RFA treatment combined with an mTOR inhibitor exerted a synergetic repressive effect on tumor growth in the preclinical murine cancer model.

Conclusions

RFA treatment in combination with mTOR signaling blockade can not only promote tumor immune response, but also restrain residual cancer cell proliferation. Such a combination may be a promising and effective therapeutic strategy for LAPC patients.

CD73 acts as a prognostic biomarker and promotes progression and immune escape in pancreatic cancer

CD73 is a glycosylphosphatidylinositol (GPI)‐anchored protein that attenuates tumour immunity via cooperating with CD39 to generate immunosuppressive adenosine. Therefore, CD73 blockade has been incorporated into clinical trials for cancers based on preclinical efficacy. However, the biological role and underlying mechanism of CD73 in pancreatic cancer (PC) microenvironment and its prognostic impact have not been comprehensively studied. In this article, we found that the expression of CD73 was up‐regulated in PC tissues and patients with higher CD73 expression had poorer overall survival (OS) and disease‐free survival (DFS) in multiple publicly available databases. Higher CD73 expression was significantly associated with its reduced methylation, and only the hypomethylation of CpG site at cg23172664 was obviously correlated with poorer OS. Then, Metascape analysis and GSEA showed that CD73 may play an important role in PC progression and immune regulations. Notably, CD73 was verified to be negatively correlated with infiltrating levels of CD8⁺ T cells and γδ⁺ T cells in both TCGA and GEO cohorts via the CIBERSORT algorithm. In addition, patients with higher CD73 expression also tended to have higher PD‐L1 expression and tumour mutation load. It seemed that CD73 might be a promising biomarker for the response to the anti‐PD‐1/PD‐L1 treatment in PC. In conclusion, these results reveal that CD73 may function as a promotor in cancer progression and a regulator in immune patterns via CD73‐related pathways. Blockade of CD73 might be a promising therapeutic strategy for PC.

The prognostic value of tumour-infiltrating lymphocytes in pancreatic cancer: a systematic review and meta-analysis

IMPORTANCE

Tumour-infiltrating lymphocytes (TILs) have previously been found to influence patient prognosis in other gastrointestinal cancers, for instance in colorectal cancer. An immunosuppressive phenotype often characterizes pancreatic cancer with a low degree of immune cell infiltration. Cytotoxic CD8⁺ T cell infiltration in tumours is found to be the best predictive variable for response to immune checkpoint inhibitor therapy, emphasizing the importance of investigating TILs in pancreatic cancer, especially focussing on CD8⁺ T cells.

OBJECTIVE

Here, we systematically review the literature and perform meta-analyses to examine the prognostic value of TILs in human pancreatic ductal adenocarcinomas (PDAC). Secondarily, we review the literature regarding the histological localization of TILs and the impact on survival in PDAC.

EVIDENCE REVIEW

A literature search was conducted on PubMed, Embase, The Cochrane Library and Web of Science. Studies examining patients with PDAC and the impact of high vs. low infiltration of immune cells on long-term oncological survival measures were included. Time-to-event meta-analysis and frequency analysis were conducted using a random effects model. The risk of bias was assessed using the Newcastle-Ottowa Scale. Quality of the cumulative evidence was evaluated using the GRADE approach for prognostic studies.

FINDINGS

In total, 1971 articles were screened, of which 43 studies were included in the systematic review and 39 in the meta-analysis. High infiltration of CD8+ lymphocytes was significantly associated with improved overall survival (OS) [hazard ratio (HR) = 0.58, 95% confidence intervals (CIs): 0.50-0.68], disease-free survival (DFS) [HR = 0.64, 95% CI: 0.52-0.78], progression-free survival [HR = 0.66, 95% CI: 0.51-0.86] and cancer-specific survival [HR = 0.56, 95% CI: 0.32-0.99]. A high infiltration of CD3+ T cells was correlated with increased OS [HR = 0.58, 95% CI: 0.50-0.68] and DFS [HR = 0.74, 95% CI: 0.38-1.43]. Infiltration of CD4+ lymphocytes was associated with improved 12-months OS [risk ratio = 0.59, 95% CI: 0.35-0.99] and DFS [risk ratio = 0.68, 95% CI: 0.53-0.88]. High expression of FoxP3+ lymphocytes was associated with poor OS [HR = 1.48, 95% CI: 1.20-1.83]. The greatest impact on survival was observed in the CD8+ T cell and OS group, when infiltration was located to the tumour centre [HR = 0.53, 95% CI: 0.45-0.63]. However, subgroup analysis on the impact of the histological location of infiltration revealed no significant differences between the subgroups (tumour centre, invasive margin, stroma and all locations) in any of the examined cell types and outcomes.

CONCLUSIONS AND RELEVANCE

Subsets of TILs, especially CD3⁺, CD8⁺ and FoxP3⁺ T cells are strongly associated with long-term oncological outcomes in patients with PDAC. To our knowledge, this is the first systematic review and meta-analysis on the prognostic value of TILs in pancreatic cancer.

Pancreatic Cancer UK Grand Challenge: Developments and challenges for effective CAR T cell therapy for pancreatic ductal adenocarcinoma

Death from pancreatic ductal adenocarcinoma (PDAC) is rising across the world and PDAC is predicted to be the second most common cause of cancer death in the USA by 2030. Development of effective biotherapies for PDAC are hampered by late presentation, a low number of differentially expressed molecular targets and a tumor-promoting microenvironment that forms both a physical, collagen-rich barrier and is also immunosuppressive. In 2017 Pancreatic Cancer UK awarded its first Grand Challenge Programme award to tackle this problem. The team plan to combine the use of novel CAR T cells with strategies to overcome the barriers presented by the tumor microenvironment. In advance of publication of those data this review seeks to highlight the key problems in effective CAR T cell therapy of PDAC and to describe pre-clinical and clinical progress in CAR T bio-therapeutics.

Survival outcomes of pancreaticoduodenectomy versus extended pancreaticoduodenectomy procedure for pancreatic head carcinoma: a propensity score matching study

BACKGROUND

It is unclear if the modified extended pancreaticoduodenectomy (PD) has better outcome superior the conventional PD for patients with pancreatic head carcinoma (PHC). The objective of this study is to compare the survival outcomes of the classic PD procedure and the modified extended PD procedure for PHC.

METHODS

A total of 7,084 resected PHC patients with PD and extended PD procedure from the SEER database from 2004 to 2014 were stratified. With the utilization of propensity score matching (PSM), patient baseline characteristics were balanced to decrease the bias. Overall survival (OS) and cancer-specific survival (CSS) were analyzed in both groups.

RESULTS

Of the 7,084 patients, 6,541 (92.3%) and 543 (7.7%) patients received PD and extended PD surgical procedures, respectively. After 2:1 ratio of PSM, 543 patients with extended PD procedure and 1,084 patients with PD procedure were completely matched. The median CSS and OS for PD and extended PD group were 20.0 and 19.0 months, and 19.0 and 18.0 months, respectively. The 5-year CSS and OS rates for PD and extended PD group were 17.5% and 16.1%, and 13.9% and 13.1%, respectively.

CONCLUSIONS

There is no distinct difference in survival outcomes between PD and extended PD procedure in patients with PHC.

Genetic landscape of prognostic value in pancreatic ductal adenocarcinoma microenvironment

Background

The prognosis of pancreatic ductal adenocarcinoma (PDAC) remains dismally poor and is widely considered as an intricate genetic disorder. The mutational landscape of PDAC may directly reflect cancer immunogenicity and dictate the extent and phenotype of immune cell infiltration. In adverse, the microenvironment may also effect the gene expression of cancer cells, which is associated with clinical prognosis. Thus, it is crucial to identify genomic alterations in PDAC microenvironment and its impacts on clinical prognosis.

Methods

The gene expression profiles, mutation data and clinical information of 179 pancreatic cancer patients with an initial pathologic diagnosis ranging from 2001 to 2013 were retrieved from The Cancer Genome Atlas (TCGA) database. The MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm for calculating immune scores and stromal scores and Tumor IMmune Estimation Resource (TIMER) resource for cell infiltrations were applied in this study.

Results

The average immune score or stromal score of PDAC subtype was significantly higher than that of other specific subtypes. KRAS mutant cases had significantly lower immune scores (P=0.001) and stromal scores (P=0.007), in concert with lower immune scores in TP53 mutant cases (P=0.030). However, no significant difference was found in SMAD4 and CDKN2A mutations. In the cohort OS/RFS, the infiltration levels of CD8+ T cells, B cells, Macrophages, Neutrophils and DCs in high stromal score group were higher than those in the low score group (all P<0.001), as well as in immune score groups except for Macrophages in the cohort RFS. In the cohort OS/RFS, 317/379 upregulated genes and 9/6 downregulated genes were observed in the high immune score group, while 227/205 upregulated genes and 17/6 downregulated genes in the high stromal score group. With the analysis for prognostic value of DEGs, 82 and 58 DEGs respectively in the high immune and stromal score group were verified to be significantly associated with better OS (P<0.05), while 53 and 17 DEGs respectively with longer RFS (P<0.05). Functional enrichment analysis showed genes of prognostic values were significantly related to immune response.

Conclusions

A list of genes with prognostic value in PDAC microenvironment were obtained from functional enrichment analysis based on immune and stromal scores, which indicates a series of potential auxiliary prognostic biomarkers for PDAC are available. Further research on these genes may be valuable and helpful to understand the crosstalk between tumor and microenvironment, new immune evasion mechanisms and underlying novel therapeutic targets in an integrated manner.

The Role Of PD-1/PD-L1 Axis In Treg Development And Function: Implications For Cancer Immunotherapy

During the past decade, immunotherapy targeting immune checkpoints has become an important component of the treatment paradigm for numerous malignancies, especially PD-1/PD-L1 blockade which was demonstrated to rejuvenate disabled T cells in cancer patients to achieve long-term remissions. However, the clinical outcome of PD-1/PD-L1 targeted monotherapy against solid malignancies is not satisfactory which may be related with the intricate tumor microenvironment. As a vital suppressive immunocyte in tumor microenvironment, Tregs are characterized by PD-1 and PD-L1 and demonstrated to contribute to the tumor progression. The latest studies have suggested that Tregs might be involved in the treatment of PD-1/PD-L1 blockade and PD-1/PD-L1 axis could influence Treg differentiation and function. However, the complicated relationship between PD-1/PD-L1 pathway and Tregs has not been fully clarified. Here, we explored the role of PD-1/PD-L1 axis in Treg development and function, as well as the potential mechanisms of PD-1/PD-L1 blockade resistance related with Tregs. Meanwhile, we discussed the combination therapy aimed at targeting PD-1/PD-L1 axis and Tregs, hoping to provide novel insights for the future cancer treatment.

Independent effect of postoperative neutrophil-to-lymphocyte ratio on the survival of pancreatic ductal adenocarcinoma with open distal pancreatosplenectomy and its nomogram-based prediction

Background: The prognosis of pancreatic ductal adenocarcinoma (PDAC) remains poor. Open distal pancreatosplenectomy (ODPS) is prevalent in the patients of early PDAC located in pancreatic body or tail. However, the models for relapse or survival prediction in those patients are still limited. Postoperative neutrophil-to-lymphocyte rate (poNLR), a novel inflammation-based score, has been formulated to analyze the prognostic significance in PDAC patients with ODPS. Therefore, this study aims to generate a valuable prognostic nomogram for PDAC following ODPS. Methods: We retrospectively enrolled 97 patients of PDAC undergoing ODPS in this study. The Cox proportional hazards regression methodology was used in univariate and multivariate survival analyses to identify significant independent prognostic factors. The prognostic nomograms integrating poNLR into the American Joint Commission on Cancer (AJCC) staging system (8th edition) for predicting overall survival (OS) and relapse free survival (RFS) were established to achieve superior discriminatory abilities. Further, these prognostic nomograms were verified according to concordance index (C-index), calibrations and decision curve analyses (DCA). Results: The optimal cut-off value of poNLR for assessing OS determined by X-tile program was 14.1. Higher poNLR was associated with higher postoperative neutrophil (poNeutrophil), lower postoperative lymphocyte (poLymphocyte), lower preoperative lymphocyte-to-monocyte rate (preLMR) and higher △NLR (postoperative-preoperative NLR). In the univariate and multivariate analysis, poNLR was identified as an independent prognostic indicator for OS and RFS (P=0.044 and 0.028, respectively) and patients with higher poNLR level were probable to have shorter OS and RFS. Compared with the TNM staging system of the AJCC 8th edition, the nomogram comprising of poNLR and AJCC 8th edition exhibited superior predictive accuracy for OS and RFS. Conclusions: poNLR can be a proven, inexpensive and novel survival predictor of PDAC patients with ODPS. One more advanced and accurate predictive model will be achieved to assist in risk stratification via the incorporation of poNLR into nomograms.

Optimized modification of the eighth edition of AJCC TNM staging system for resected pancreatic ductal adenocarcinoma

Aim: To reassess the prognostic performance of the American Joint Committee on Cancer (AJCC) 8th edition for pancreatic ductal adenocarcinoma (PDAC) and optimize the categorization of PDAC staging. Patients & methods: A total of 11,858 patients with resected PDAC from the Surveillance, Epidemiology and End Results database were retrospectively enrolled by sequential analyses. Results: There was no statistical significance between stage IIA and IIB tumors with hazard ratios of 2.065 and 2.184 (p = 0.620) for stages IIA and IIB, respectively. With the proposed modification, there was a significant difference between the hazard ratios of stages IIIA and IIIB which were 2.481 and 2.715, respectively (p = 0.009). The C-index of modified system was 0.609, slightly higher than AJCC 8th staging system 0.604. Conclusion: We proposed a modified eighth edition of the AJCC staging system by combining stage IIA with IIB and further subclassifying stage III patients in order to lead to better discriminative power.

TGF-β signaling in cell fate control and cancer

Members of the transforming growth factor-β (TGF-β) family regulate cell fate decisions during early embryonic development and tissue homeostasis in the adult. Deregulation of TGF-β family signaling contributes to developmental anomalies, fibrotic disorders, tumorigenesis and immune diseases. TGF-β exerts a wide spectrum of cellular functions by activating canonical (SMAD-dependent) or non-canonical (SMAD-independent) pathways in a cell type-specific and context-dependent manner. Here, we focus on recent advances in the understanding of the mechanisms and functions of SMAD and non-SMAD pathways in physiology and pathology.

Blockade of TGF-β signaling: a potential target for cancer immunotherapy?

Introduction: Malignant tumors often escape surveillance and eventual destruction by the host immune system through a variety of strategies including production of transforming growth factor (TGF)-β. Because of its generally immunosuppressive role, TGF-β has emerged as a promising therapeutic target in cancer immunotherapy. Areas covered: This article looks at specific mechanisms of how TGF-β controls the function of various immune cell subsets in the tumor microenvironment and focusses on T-cells. Various inhibition tools of TGF-β signaling and potential targets of therapeutic intervention are assessed along with the recent progress in combining TGF-β blockade and immune-mediated therapies. To round off the article, a summary of results from clinical trials is provided in which TGF-β blockade has shown therapeutic benefit for patients. Expert opinion: Data from preclinical models have shown that blocking TGF-β signaling can overcome resistance mechanisms and in combination with immune-checkpoint therapies, can yield additive or synergistic anti-tumor responses. The future of immunooncology will therefore be based on combination trials. Since response rates may critically depend on both cancer type and stage, selection of only those patients who can benefit from combinatorial immunotherapy regimens is of utmost importance.

Cell-intrinsic PD-1 promotes proliferation in pancreatic cancer by targeting CYR61/CTGF via the hippo pathway

Pancreatic ductal adenocarcinoma (PDAC) remains a refractory disease. Programmed cell death protein-1 (PD-1) monotherapy has shown strong performance in targeting several malignancies. However, the effect and mechanism of intrinsic PD-1 in pancreatic cancer cells is still unknown. In this study, associations between clinicopathological characteristics and stained tissue microarrays of PDAC specimens were analyzed along with profiling and functional analyses. The results showed that cell-intrinsic PD-1 was significantly correlated with overall survival (OS). Independently of adaptive immunity, intrinsic PD-1 promoted tumor growth in PDAC. Concomitantly, the overexpression of intrinsic PD-1 enhanced cancer proliferation and inhibited cell apoptosis in vitro and in vivo. Mechanistically, PD-1 binds to the downstream MOB1, thereby inhibiting its phosphorylation. Moreover, greater synergistic tumor suppression in vitro resulted from combining Hippo inhibitors with anti-PD-1 treatment compared with the suppression achieved by either single agent alone. Additionally, Hippo downstream targets, CYR61 (CCN1) and CTGF (CCN2), were directly affected by PD-1 mediated Hippo signaling activation in concert with survival outcomes. Finally, the formulated nomogram showed superior predictive accuracy for OS in comparison with the TNM stage alone. Therefore, PD-1 immunotherapy in combination with Hippo pathway inhibitors may optimize the anti-tumor efficacy in PDAC patients via targeting cell-intrinsic PD-1.