Selective multi-kinase inhibition sensitizes mesenchymal pancreatic cancer to immune checkpoint blockade by remodeling the tumor microenvironment

The Biology in the Pattern: Metastatic Organotropism and Clinical Outcome Depend on DNA Damage Response and Immune Interactions in Pancreatic Cancer

Metastatic cancer remains a leading cause of cancer-related mortality, with a 5-year survival rate of just 8% for pancreatic ductal adenocarcinoma (PDAC). Among patients with metastatic PDAC, those with liver metastases experience significantly worse outcomes compared with the rare cases of isolated lung metastases. Recent findings by Link and colleagues reveal that these distinct metastatic patterns reflect underlying biological differences beyond established molecular subtypes. Specifically, the authors curated a primary organotropism (pORG) gene signature that is enriched in the liver cohort. In detail they found that high-pORG/liver-avid tumors are characterized by high replication stress, enriched DNA repair pathways, and an immunosuppressive microenvironment, whereas low-pORG/lung-avid tumors display stronger immune infiltration, higher T-cell density, reduced richness of T-cell receptor repertoire, and better survival outcomes. These insights suggest that the clinical pattern of metastasis provides meaningful information about tumor biology and prognosis, complementing current subtype classifications in PDAC.

PLK1 blockade enhances the anti-tumor effect of MAPK inhibition in pancreatic ductal adenocarcinoma

Despite constitutive Ras/Raf/MAPK pathway activation in most pancreatic ductal adenocarcinomas (PDACs), treatment approaches targeting this pathway have primarily been unsuccessful. We conduct a drug library screen on an MEK inhibitor (MEKi)-resistant PDAC model and perform complementary pathway analysis to identify cellular resistance phenotypes. We use syngeneic models to investigate the molecular determinants of identified drug synergism. Our study reveals an enrichment for the hallmarks of G2/M checkpoints in MEKi-resistant phenotypes from all investigated models. We find overexpression of Polo-like kinase 1 (PLK1) and other G2/M checkpoint-related proteins in MEKi-resistant cells. We identify synergistic activity between MEK and PLK1 inhibition both in vitro and in vivo and mechanistically show that dual inhibition of the PLK1 and MEK pathways activates the JNK/c-JUN pathway. This causes the accumulation of DNA damage, ultimately leading to apoptotic cell death. Dual PLK1/MEK inhibition emerges as a promising targeted approach in PDAC.

Efficacy of combined immunotherapy and targeted therapy in overcoming barriers to postoperative recurrence in squamous subtype anaplastic thyroid carcinoma with abscess: a case report and literature review

Background

Molecularly targeted therapies and immunotherapy are increasingly being employed in the treatment of aggressive, recurrent thyroid cancer. Evidence from several studies indicates that a significant proportion of tumor patients derive limited benefit from immunotherapy as a monotherapy, with vascular abnormalities in solid tumors contributing to immune evasion. Numerous studies, both domestic and international, have assessed the efficacy of combining immune checkpoint inhibitors with antiangiogenic agents across various tumor types. These studies suggest that such combination therapies are effective in controlling disease progression and extending survival, among other outcomes. Nevertheless, further research is warranted to substantiate these findings and optimize treatment protocols.

Methods

This study aims to describe a patient diagnosed with anaplastic thyroid carcinoma (ATC) combined with primary squamous cell carcinoma of the thyroid (PSCCT) and concurrent thyroid abscess. The patient experienced local recurrence and metastasis following surgical intervention, radiotherapy, and chemotherapy, and was found to be PD-1 negative. Disease progression was effectively controlled through combination therapy with anlotinib and tislelizumab. Additionally, a comprehensive review of the relevant literature was conducted.

Results

The patient exhibited disease recurrence 8 months postoperatively, notwithstanding the administration of adjuvant radiotherapy and chemotherapy. The local recurrent mass demonstrated minimal reduction following 4 cycles of targeted therapy with anlotinib. However, subsequent treatment with a combination of anlotinib and tislelizumab resulted in a substantial reduction of the neck mass and enlarged cervical lymph nodes after 12 cycles. The patient tolerated the combination therapy well, experiencing no significant adverse effects aside from pronounced fatigue. Thus, the combination therapy with anlotinib and tislelizumab proved effective in controlling the disease.

Conclusion

The management of postoperative recurrence of ATC-PSCCT presents significant challenges, as recurrent tumors typically demonstrate increased aggressiveness and resistance to pharmacological interventions, necessitating multimodal therapeutic approaches. Tislelizumab, an immune checkpoint inhibitor, may facilitate immune-mediated tumor clearance through the activation of various immune cells, including natural killer cells and macrophages. Despite the patient's PD-1 negativity, the combination of anlotinib and tislelizumab may exert synergistic effects through distinct mechanisms, thereby potentially enhancing therapeutic efficacy. The integration of a multi-targeted tyrosine kinase inhibitor within this combination therapy regimen warrants further investigation.

Translating the multifaceted use of liquid biopsy to management of early disease in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related mortality, primarily due to late stage at diagnosis. This review examines the multifaceted applications of liquid biopsy and circulating tumor DNA (ctDNA) analysis in the diagnosis and management of PDAC. We review the current literature on the technological advancements in liquid biopsy analysis such as next generation sequencing (NGS) and digital droplet PCR (ddPCR) as well as multi-omics technologies, highlighting their potential for accurate molecular subtyping through ctDNA analysis. This review highlights the significant role of ctDNA in the assessment of tumor behavior, disease subtyping, prediction and monitoring of treatment response, and evaluation of minimal residual disease. We discuss the implications of integrating liquid biopsy techniques into clinical practice as well as its challenges and limitations. By drawing insights from recent studies, this review aims to provide a comprehensive overview of how liquid biopsy and ctDNA analysis can enhance early disease management strategies in PDAC. We underscore the need for additional prospective studies and clinical trials to validate its feasibility and accuracy in order to establish clinical utility, with the ultimate goal of routine incorporation into practice to improve patient outcomes and transform the treatment landscape for PDAC.

Gemcitabine and ATR inhibitors synergize to kill PDAC cells by blocking DNA damage response

The DNA-damaging agent Gemcitabine (GEM) is a first-line treatment for pancreatic cancer, but chemoresistance is frequently observed. Several clinical trials investigate the efficacy of GEM in combination with targeted drugs, including kinase inhibitors, but the experimental evidence for such rationale is often unclear. Here, we phenotypically screened 13 human pancreatic adenocarcinoma (PDAC) cell lines against GEM in combination with 146 clinical inhibitors and observed strong synergy for the ATR kinase inhibitor Elimusertib in most cell lines. Dose-dependent phosphoproteome profiling of four ATR inhibitors following DNA damage induction by GEM revealed a strong block of the DNA damage response pathway, including phosphorylated pS468 of CHEK1, as the underlying mechanism of drug synergy. The current work provides a strong rationale for why the combination of GEM and ATR inhibition may be useful for the treatment of PDAC patients and constitutes a rich phenotypic and molecular resource for further investigating effective drug combinations.

KRASG 12C-inhibitor-based combination therapies for pancreatic cancer: insights from drug screening

Pancreatic ductal adenocarcinoma (PDAC) has limited treatment options, emphasizing the urgent need for effective therapies. The predominant driver in PDAC is mutated KRAS proto-oncogene, KRA, present in 90% of patients. The emergence of direct KRAS inhibitors presents a promising avenue for treatment, particularly those targeting the KRASG12C mutated allele, which show encouraging results in clinical trials. However, the development of resistance necessitates exploring potent combination therapies. Our objective was to identify effective KRASG12C-inhibitor combination therapies through unbiased drug screening. Results revealed synergistic effects with son of sevenless homolog 1 (SOS1) inhibitors, tyrosine-protein phosphatase non-receptor type 11 (PTPN11)/Src homology region 2 domain-containing phosphatase-2 (SHP2) inhibitors, and broad-spectrum multi-kinase inhibitors. Validation in a novel and unique KRASG12C-mutated patient-derived organoid model confirmed the described hits from the screening experiment. Our findings propose strategies to enhance KRASG12C-inhibitor efficacy, guiding clinical trial design and molecular tumor boards.

Deciphering the potential ability of DExD/H-box helicase 60 (DDX60) on the proliferation, diagnostic and prognostic biomarker in pancreatic cancer: a research based on silico, RNA-seq and molecular biology experiment

BACKGROUND

Pancreatic cancer is one of the most malignant abdominal tumors. DDX60 has been shown to be associated with a variety of tumor biological processes. However, DDX60 in pancreatic cancer has not been reported. Our study confirmed that DDX60 can serve as a novel biomarker for diagnosis and treatment of pancreatic cancer.

MATERIALS AND METHODS

We downloaded pancreatic cancer datasets from GEO and TCGA databases, respectively. To investigate the relationship between DDX60 expression and prognosis in pancreatic cancer. GSEA analysis was performed on DDX60. We performed RNA-seq to further explore the downstream biological targets of DDX60 and the signaling pathways that may be involved in pancreatic cancer. Finally, we tested it through molecular biology experiments. First, we constructed the plasmid and tested the plasmid effect by WB. Then MTT assay was performed to explore the effect of DDX60 knockout on the proliferation of pancreatic cancer cells. LDH assay was performed to explore the effect of DDX60 on the release of lactate dehydrogenase from tumor cells. The effect of DDX60 on cell proliferation was further explored by clonal formation experiment. Continue to explore clinical therapeutic drugs sensitive to DDX60 targets.

RESULTS

By analyzing the GSE71729, GSE183795, GSE16515, GSE28735 and GSE62452 data sets, we found that DDX60 was highly expressed in pancreatic cancer. And is associated with poorer outcomes for pancreatic patients. The mRNA expression level of DDX60 was correlated with lymph node metastasis and grade in clinical pancreatic patients. Through the results of RNA-seq analysis, GO and KEGG analysis showed that DDX60 may be associated with cell cycle in pancreatic cancer. Through molecular biology experiments (MTT, LDH, and clonal formation experiment), we found that When DDX60 is knocked down in pancreatic cancer cells, the proliferation ability of tumor cells is significantly decreased. Several drugs targeting about DDX60 have been found, such as JW-7-52-1, this could provide direction for drug therapy against the DDX60 target.

CONCLUSION

In summary, DDX60 can be used as a novel biomarker related to the diagnosis and treatment of pancreatic cancer, participate in tumor proliferation, and is associated with poor prognosis in patients.

Looking Beyond Checkpoint Inhibitor Monotherapy: Uncovering New Frontiers for Pancreatic Cancer Immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) stands out as one of the most aggressive and challenging tumors, characterized by a bleak prognosis with a mere 11% survival rate over 5 years in the United States. Its formidable nature is primarily attributed to its highly aggressive behavior and poor response to existing therapies. PDAC, being notably resistant to immune interventions, presents a significant obstacle in treatment strategies. While immune checkpoint inhibitor therapies have revolutionized outcomes for various cancers, their efficacy in PDAC remains exceedingly low, benefiting less than 1% of patients. The consistent failure of these therapies in PDAC has prompted intensive investigation, particularly at the preclinical level, to unravel the intricate mechanisms of resistance inherent in this cancer type. This pursuit aims to pave the way for the development of novel immunotherapeutic strategies tailored to the distinct characteristics of PDAC. This review endeavors to provide a comprehensive exploration of these emerging immunotherapy approaches in PDAC, with a specific emphasis on elucidating their underlying immunological mechanisms. Additionally, it sheds light on the recently identified factors driving resistance to immunotherapy and evasion of the immune system in PDAC, offering insights beyond the conventional drivers that have been extensively studied.

Bispecific antibody targeting of lipid nanoparticles

Lipid nanoparticles (LNP) are the most clinically advanced non-viral gene delivery system. While progress has been made for enhancing delivery, cell specific targeting remains a challenge. Targeting moieties such as antibodies can be chemically-conjugated to LNPs however, this approach is complex and has challenges for scaling up. Here, we developed an approach to generate antibody-conjugated LNPs that utilizes a bispecific antibody (bsAb) as the targeting bridge. As a docking site for the bsAb, we generated LNPs with a short epitope, derived from hemagglutinin antigen (HA), embedded in the PEG component of the particle (LNPHA). We generated bsAb in which one domain binds HA and the other binds different cell surface proteins, including PD-L1, CD4, CD5, and SunTag. Non-chemical conjugation of the bsAb and LNP resulted in a major increase in the efficiency and specificity of transfecting cells expressing the cognate target. LNP/bsAb mediated a 4-fold increase in in vivo transfection of PD-L1 expressing cancer cells, and a 26-fold increase in ex vivo transfection of quiescent primary human T cells. Additionally, we created a universal bsAb recognizing HA and anti-rat IgG2, enabling LNP tethering to off-the-shelf antibodies such as CD4, CD8, CD20, CD45, and CD3. By utilizing a molecular dock and bsAb technology, these studies demonstrate a simple and effective strategy to generate antibody-conjugated LNPs, enabling precise and efficient mRNA delivery.

Heterogeneity-driven phenotypic plasticity and treatment response in branched-organoid models of pancreatic ductal adenocarcinoma

In patients with pancreatic ductal adenocarcinoma (PDAC), intratumoural and intertumoural heterogeneity increases chemoresistance and mortality rates. However, such morphological and phenotypic diversities are not typically captured by organoid models of PDAC. Here we show that branched organoids embedded in collagen gels can recapitulate the phenotypic landscape seen in murine and human PDAC, that the pronounced molecular and morphological intratumoural and intertumoural heterogeneity of organoids is governed by defined transcriptional programmes (notably, epithelial-to-mesenchymal plasticity), and that different organoid phenotypes represent distinct tumour-cell states with unique biological features in vivo. We also show that phenotype-specific therapeutic vulnerabilities and modes of treatment-induced phenotype reprogramming can be captured in phenotypic heterogeneity maps. Our methodology and analyses of tumour-cell heterogeneity in PDAC may guide the development of phenotype-targeted treatment strategies.

Differential activity of MAPK signalling defines fibroblast subtypes in pancreatic cancer

Fibroblast heterogeneity is increasingly recognised across cancer conditions. Given their important contribution to disease progression, mapping fibroblasts' heterogeneity is critical to devise effective anti-cancer therapies. Cancer-associated fibroblasts (CAFs) represent the most abundant cell population in pancreatic ductal adenocarcinoma (PDAC). Whether CAF phenotypes are differently specified by PDAC cell lineages remains to be elucidated. Here, we reveal an important role for the MAPK signalling pathway in defining PDAC CAF phenotypes. We show that epithelial MAPK activity promotes the myofibroblastic differentiation of CAFs by sustaining the expression and secretion of TGF-β1. We integrate single-cell profiling of post-perturbation transcriptional responses from mouse models with cellular and spatial profiles of human tissues to define a MAPKhigh CAF (mapCAF) phenotype. We show that this phenotype associates with basal-like tumour cells and reduced frequency of CD8+ T cells. In addition to elevated MAPK activity, this mapCAF phenotype is characterized by TGF-β signalling, hypoxia responsive signatures, and immunoregulatory gene programs. Furthermore, the mapCAF signature is enriched in myofibroblastic CAFs from various cancer conditions and correlates with reduced response to immune checkpoint inhibition in melanoma. Altogether, our data expand our knowledge on CAF phenotype heterogeneity and reveal a potential strategy for targeting myofibroblastic CAFs in vivo.

Low-dose arsenic trioxide inhibits pancreatic stellate cell activation via LOXL3 expression to enhance immunotherapy in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is characterized by abnormally fibrotic mesenchyme, which notably influences on the effectiveness of immunotherapy. Low-dose arsenic trioxide (ATO, 1.0 μM) can inhibit the activation of pancreatic stellate cells (PSCs) and affect fibrosis, which is a potential strategy for enhancing the sensitivity to immunotherapy.

METHODS

Extracellular matrix (ECM) models were employed to assess the regulatory effects of ATO on ECM and peripheral blood mononuclear cells. Orthotopic C57BL/6J models were utilized to evaluate the influence of ATO on CD8+T cell infiltration and immunotherapy in PC. Additionally, nanomaterials loaded with ATO designed to specifically target PSCs (scAbFAP-α-HMSNs-PAA-ATO) were produced to enhance targeting effects of ATO.

RESULTS

Low-dose ATO (1.0 μM) suppressed PSCs activation, exhibiting potential for synergistic immunotherapy. Under low-dose ATO intervention, ECM underwent remodeling, leading to increases in CD8+T cell infiltration, thereby enhancing anti-PD-L1 therapy effect. We further demonstrated that low-dose ATO remodeled ECM by regulating the expression of LOXL3 in PSCs. scAbFAP-α-HMSNs-PAA-ATO exhibited improved targeting capabilities, and enhanced capacity to inhibit fibrosis and sensitize immunotherapy.

CONCLUSIONS

Our research reveals that low-dose ATO, by regulating LOXL3, remodels the ECM and enhances CD8+T cell infiltration, thus sensitizing the efficacy of immunotherapy, which provides a novel strategy for comprehensive treatment to PC.

Tissue-colonizing disseminated tumor cells secrete prostaglandin E2 to promote NK cell dysfunction and evade anti-metastatic immunity

Natural killer (NK) cells are critical for anti-metastatic immunity and can eliminate metastasizing tumor cells within circulation and sites of metastatic seeding. Here, we show that disseminated tumor cells (DTCs) colonizing the mouse lung secrete prostaglandin E2 (PGE2) to locally induce NK cell dysfunction, allowing outgrowing metastases to escape immune control and establish metastatic disease. Mechanistically, PGE2 signaling through its receptors EP2 and EP4 mediates NK cell dysfunction, which leads to reprogramming of NK cell gene expression and results in impaired production of anti-metastatic cytokines. In human cancer patients, the PGE2-EP2/EP4 axis is associated with NK cell dysfunction within distant organ metastases. Disabling EP2/EP4 signaling in NK cells prevents their dysfunction in DTC-colonized lungs and achieves effective NK cell-mediated control of metastatic disease. Our findings reveal a suppressive signaling axis exploited by metastasizing tumor cells to escape immune control in distant organs that could be targeted for metastatic cancer therapy.

Spatially resolved analysis of pancreatic cancer identifies therapy-associated remodeling of the tumor microenvironment

In combination with cell-intrinsic properties, interactions in the tumor microenvironment modulate therapeutic response. We leveraged single-cell spatial transcriptomics to dissect the remodeling of multicellular neighborhoods and cell-cell interactions in human pancreatic cancer associated with neoadjuvant chemotherapy and radiotherapy. We developed spatially constrained optimal transport interaction analysis (SCOTIA), an optimal transport model with a cost function that includes both spatial distance and ligand-receptor gene expression. Our results uncovered a marked change in ligand-receptor interactions between cancer-associated fibroblasts and malignant cells in response to treatment, which was supported by orthogonal datasets, including an ex vivo tumoroid coculture system. We identified enrichment in interleukin-6 family signaling that functionally confers resistance to chemotherapy. Overall, this study demonstrates that characterization of the tumor microenvironment using single-cell spatial transcriptomics allows for the identification of molecular interactions that may play a role in the emergence of therapeutic resistance and offers a spatially based analysis framework that can be broadly applied to other contexts.

Hematopoietic aging promotes cancer by fueling IL-1⍺-driven emergency myelopoiesis

Age is a major risk factor for cancer, but how aging impacts tumor control remains unclear. In this study, we establish that aging of the immune system, regardless of the age of the stroma and tumor, drives lung cancer progression. Hematopoietic aging enhances emergency myelopoiesis, resulting in the local accumulation of myeloid progenitor-like cells in lung tumors. These cells are a major source of interleukin (IL)-1⍺, which drives the enhanced myeloid response. The age-associated decline of DNA methyltransferase 3A enhances IL-1⍺ production, and disrupting IL-1 receptor 1 signaling early during tumor development normalized myelopoiesis and slowed the growth of lung, colonic, and pancreatic tumors. In human tumors, we identified an enrichment for IL-1⍺-expressing monocyte-derived macrophages linked to age, poorer survival, and recurrence, unraveling how aging promotes cancer and offering actionable therapeutic strategies.

Proteomics mining of cancer hallmarks on a single-cell resolution

Dysregulated proteome is an essential contributor in carcinogenesis. Protein fluctuations fuel the progression of malignant transformation, such as uncontrolled proliferation, metastasis, and chemo/radiotherapy resistance, which severely impair therapeutic effectiveness and cause disease recurrence and eventually mortality among cancer patients. Cellular heterogeneity is widely observed in cancer and numerous cell subtypes have been characterized that greatly influence cancer progression. Population-averaged research may not fully reveal the heterogeneity, leading to inaccurate conclusions. Thus, deep mining of the multiplex proteome at the single-cell resolution will provide new insights into cancer biology, to develop prognostic biomarkers and treatments. Considering the recent advances in single-cell proteomics, herein we review several novel technologies with particular focus on single-cell mass spectrometry analysis, and summarize their advantages and practical applications in the diagnosis and treatment for cancer. Technological development in single-cell proteomics will bring a paradigm shift in cancer detection, intervention, and therapy.

Time - The fourth dimension of immune cells

Deciphering the intricate cell-state transitions orchestrating immune adaptation over time stands as a cornerstone for advancing biological understanding. However, the lack of empirical in vivo genomic technologies capable of capturing cellular dynamics has posed a significant challenge. In response to this gap, a groundbreaking study introduces Zman-seq, a single-cell technology that records transcriptomic dynamics across time by incorporating time stamps into circulating immune cells, enabling their tracking in tissues for extended periods. The application of Zman-seq in glioblastoma research has successfully unraveled the cell state and molecular trajectories underlying the dysfunctional immune microenvironment. Understanding the temporal aspects of cell-state transitions during immune responses is pivotal for advancing our knowledge in biology. The emergence of Zman-seq addresses the current limitations in empirical in vivo genomic technologies, offering a revolutionary approach to studying the dynamics of immune cells over time. This highlight comprehensively explores the implications of Zman-seq in resolving cell-state transitions and molecular trajectories within the dysfunctional immune microenvironment in different types of immunotherapy. This technique has particular potential for chimeric antigen receptor T-cell therapy, overriding drug resistance, clinical medication optimization, and facilitating drug development. In particular, this article discusses potential strategies for improving the efficacy of clinical treatments.

A Novel AMPK Inhibitor Sensitizes Pancreatic Cancer Cells to Ferroptosis Induction

Cancer cells must develop strategies to adapt to the dynamically changing stresses caused by intrinsic or extrinsic processes, or therapeutic agents. Metabolic adaptability is crucial to mitigate such challenges. Considering metabolism as a central node of adaptability, it is focused on an energy sensor, the AMP-activated protein kinase (AMPK). In a subtype of pancreatic ductal adenocarcinoma (PDAC) elevated AMPK expression and phosphorylation is identified. Using drug repurposing that combined screening experiments and chemoproteomic affinity profiling, it is identified and characterized PF-3758309, initially developed as an inhibitor of PAK4, as an AMPK inhibitor. PF-3758309 shows activity in pre-clinical PDAC models, including primary patient-derived organoids. Genetic loss-of-function experiments showed that AMPK limits the induction of ferroptosis, and consequently, PF-3758309 treatment restores the sensitivity toward ferroptosis inducers. The work established a chemical scaffold for the development of specific AMPK-targeting compounds and deciphered the framework for the development of AMPK inhibitor-based combination therapies tailored for PDAC.

Understanding the Conundrum of Pancreatic Cancer in the Omics Sciences Era

Pancreatic cancer (PC) is an increasing cause of cancer-related death, with a dismal prognosis caused by its aggressive biology, the lack of clinical symptoms in the early phases of the disease, and the inefficacy of treatments. PC is characterized by a complex tumor microenvironment. The interaction of its cellular components plays a crucial role in tumor development and progression, contributing to the alteration of metabolism and cellular hyperproliferation, as well as to metastatic evolution and abnormal tumor-associated immunity. Furthermore, in response to intrinsic oncogenic alterations and the influence of the tumor microenvironment, cancer cells undergo a complex oncogene-directed metabolic reprogramming that includes changes in glucose utilization, lipid and amino acid metabolism, redox balance, and activation of recycling and scavenging pathways. The advent of omics sciences is revolutionizing the comprehension of the pathogenetic conundrum of pancreatic carcinogenesis. In particular, metabolomics and genomics has led to a more precise classification of PC into subtypes that show different biological behaviors and responses to treatments. The identification of molecular targets through the pharmacogenomic approach may help to personalize treatments. Novel specific biomarkers have been discovered using proteomics and metabolomics analyses. Radiomics allows for an earlier diagnosis through the computational analysis of imaging. However, the complexity, high expertise required, and costs of the omics approach are the main limitations for its use in clinical practice at present. In addition, the studies of extracellular vesicles (EVs), the use of organoids, the understanding of host-microbiota interactions, and more recently the advent of artificial intelligence are helping to make further steps towards precision and personalized medicine. This present review summarizes the main evidence for the application of omics sciences to the study of PC and the identification of future perspectives.

PA28γ coordinates the cross-talk between cancer-associated fibroblasts and tumor cells to promote OSCC progression via HDAC1/E2F3/IGF2 signaling

PA28γ overexpression is aberrant and accompanied by poor patient prognosis in various cancers, the precise regulatory mechanism of this crucial gene in the tumor microenvironment remains incompletely understood. In this study, using oral squamous cell carcinoma as a model, we demonstrated that PA28γ exhibits high expression in cancer-associated fibroblasts (CAFs), and its expression significantly correlates with the severity of clinical indicators of malignancy. Remarkably, we found that elevated levels of secreted IGF2 from PA28γ+ CAFs can enhance stemness maintenance and promote tumor cell aggressiveness through the activation of the MAPK/AKT pathway in a paracrine manner. Mechanistically, PA28γ upregulates IGF2 expression by stabilizing the E2F3 protein, a transcription factor of IGF2. Further mechanistic insights reveal that HDAC1 predominantly mediates the deacetylation and subsequent ubiquitination and degradation of E2F3. Notably, PA28γ interacts with HDAC1 and accelerates its degradation via a 20S proteasome-dependent pathway. Additionally, PA28γ+ CAFs exert an impact on the tumor immune microenvironment by secreting IGF2. Excitingly, our study suggests that targeting PA28γ+ CAFs or secreted IGF2 could increase the efficacy of PD-L1 therapy. Thus, our findings reveal the pivotal role of PA28γ in cell interactions in the tumor microenvironment and propose novel strategies for augmenting the effectiveness of immune checkpoint blockade in oral squamous cell carcinoma.

Role of vascular endothelial growth factor D in lung adenocarcinoma immunotherapy response

OBJECTIVE

To identify key genes associated with tumor-associated macrophages (TAMs), tumor immunotherapy, in the prognosis of lung adenocarcinoma (LUAD).

METHODS

The mRNA expression profiles of LUAD samples were obtained from The Cancer Genome Atlas (TCGA) database. The "CIBERSORT" R package was employed to calculate the proportion of innate immune cell infiltration in both tumor and adjacent normal tissues. TAM-associated genes in LUAD were identified to construct a prognostic risk model using weighted gene correlation network analysis (WGCNA), Least Absolute Shrinkage and Selection Operator (LASSO), and multivariate Cox regression analyses (COX). The IMvigor210 cohort was utilized to validate the roles of these genes as predictors of immunotherapy response. Tissue microarrays, immunofluorescence staining, and mRNA level detection methods were used to determine the correlation of risk factors in LUAD tissues.

RESULTS

CIBERSORT analysis revealed significant differences in innate immune cells between tumor and adjacent tissues. Seventy-four differential genes linked to these cells were identified from WGCNA. Four hub genes (endothelin receptor type B, vascular endothelial growth factor D (VEGFD), latent transforming growth factor beta binding protein 4 (LTBP4), and fibroblast growth factor receptor 4 (FGFR4)) in the TAM prognostic model were identified as independent prognostic risk factors (P < 0.05). VEGFD expression was identified as a low-risk factor for LUAD prognosis prediction (P < 0.05). Moreover, low-risk patients exhibited higher sensitivity to anti-PD-L1 therapy compared to high-risk patients (P < 0.05). VEGFD levels were negatively correlated with programmed cell death 1 (PD-1) levels (r = -0.363; P < 0.05), suggesting that VEGFD may serve as a predictor for anti-PD-1 treatment.

CONCLUSIONS

VEGFD is associated with innate immunity in LUAD, it can predict LUAD prognosis, and therefor may be a potential predictor for anti-PD-1 treatment in patients with LUAD.

First-line penpulimab (an anti-PD1 antibody) and anlotinib (an angiogenesis inhibitor) with nab-paclitaxel/gemcitabine (PAAG) in metastatic pancreatic cancer: a prospective, multicentre, biomolecular exploratory, phase II trial

Metastatic pancreatic cancer (mPC) has a dismal prognosis. Herein, we conducted a prospective, multicentre, single-arm, phase II trial evaluating the efficacy and safety of penpulimab and anlotinib in combination with nab-paclitaxel/gemcitabine (PAAG) in patients with first-line mPC (NCT05493995). The primary endpoints included the objective response rate (ORR) and disease control rate (DCR), while secondary endpoints encompassed progression-free survival (PFS), overall survival (OS), and safety. In 66 patients analysed for efficacy, the best response, indicated by the ORR, was recorded at 50.0% (33/66) (95% CI, 37.4-62.6%), with 33 patients achieving partial response (PR). Notably, the DCR was 95.5% (63/66, 95% CI, 87.3-99.1%). The median PFS (mPFS) and OS (mOS) were 8.8 (95% CI, 8.1-11.6), and 13.7 (95% CI, 12.4 to not reached) months, respectively. Grade 3/4 treatment-related adverse events (TRAEs) were reported in 39.4% of patients (26/66). In prespecified exploratory analysis, patients with altered SWI/SNF complex had a poorer PFS. Additionally, low serum CA724 level, high T-cell recruitment, low Th17 cell recruitment, and high NK CD56dim cell scores at baseline were potential predicative biomarkers for more favourable efficacy. In conclusion, PAAG as a first-line therapy demonstrated tolerability with promising clinical efficacy for mPC. The biomolecular findings identified in this study possess the potential to guide the precise clinical application of the triple-combo regimen.

A Hypoxia-Epigenetics Axis Drives EMT in Pancreatic Cancer

Epithelial-to-mesenchymal transition (EMT) is a classical cellular plasticity process induced by various cell-intrinsic and -extrinsic triggers. Although prominent factors, such as TGFβ, mediate EMT via well-characterized pathways, alternative avenues are less well understood. Transcriptomic subtyping of pancreatic ductal adenocarcinoma (PDAC) has demonstrated that basal-like PDACs enrich a mesenchymal-like expression program, emphasizing the relevance of EMT in the disease. In this issue of Cancer Research, Brown and colleagues demonstrate the tight connection of EMT to hypoxia. Through a detailed mechanistic analysis, the authors deciphered that hypoxia-induced signals are integrated by the histone H3 lysine 36 di-methylation (H3K36me2) mark. On the one hand, hypoxia decreased activity of the H3K36me2 eraser KDM2A, while on the other hand promoting stabilization of the H3K36me2 writer NSD2. Hypoxia diminished the expression of a set of serine-threonine phosphatases, subsequently resulting in SRC kinase family-dependent activation of canonical MEK, ERK, and JNK signaling to impinge on NSD2 expression. In addition, reduced expression of the protein phosphatase PP2Cδ was linked to increased NSD2 protein expression. These discoveries illuminate the close relationship of hypoxia signaling to the epigenetic machinery and cellular plasticity processes. See related article by Brown et al., p. 1764.

PI3Kγ inhibition combined with DNA vaccination unleashes a B-cell-dependent antitumor immunity that hampers pancreatic cancer

Phosphoinositide-3-kinase γ (PI3Kγ) plays a critical role in pancreatic ductal adenocarcinoma (PDA) by driving the recruitment of myeloid-derived suppressor cells (MDSC) into tumor tissues, leading to tumor growth and metastasis. MDSC also impair the efficacy of immunotherapy. In this study we verify the hypothesis that MDSC targeting, via PI3Kγ inhibition, synergizes with α-enolase (ENO1) DNA vaccination in counteracting tumor growth.Mice that received ENO1 vaccination followed by PI3Kγ inhibition had significantly smaller tumors compared to those treated with ENO1 alone or the control group, and correlated with i) increased circulating anti-ENO1 specific IgG and IFNγ secretion by T cells, ii) increased tumor infiltration of CD8+ T cells and M1-like macrophages, as well as up-modulation of T cell activation and M1-like related transcripts, iii) decreased infiltration of Treg FoxP3+ T cells, endothelial cells and pericytes, and down-modulation of the stromal compartment and T cell exhaustion gene transcription, iv) reduction of mature and neo-formed vessels, v) increased follicular helper T cell activation and vi) increased "antigen spreading", as many other tumor-associated antigens were recognized by IgG2c "cytotoxic" antibodies. PDA mouse models genetically devoid of PI3Kγ showed an increased survival and a pattern of transcripts in the tumor area similar to that of pharmacologically-inhibited PI3Kγ-proficient mice. Notably, tumor reduction was abrogated in ENO1 + PI3Kγ inhibition-treated mice in which B cells were depleted.These data highlight a novel role of PI3Kγ in B cell-dependent immunity, suggesting that PI3Kγ depletion strengthens the anti-tumor response elicited by the ENO1 DNA vaccine.

Synergistic induction of autophagy in gastric cancer by targeting CDK4/6 and MEK through AMPK/mTOR pathway

KRAS is a commonly mutated oncogene in human gastric cancer and is often associated with drug resistance and poor prognosis. Co-clinical trial of combined MEK-CDK4/6 inhibition in KRAS mutated cancers demonstrated therapeutic efficacy in patient-derived xenografts and safety in patients. Here, present research focuses on targeting CDK4/6 and MEK synergistically block the proliferation of KRAS-mutated gastric cancer cells in vitro and in vivo and induced autophagy through the AMPK/mTOR pathway. Furthermore, autophagy inhibitor combined with targeting CDK4/6 and MEK therapy had significant antitumor effects on KRAS mutant gastric cancer cells. Clinical trials are needed to determine the mechanism behind this finding and its clinical utility. In conclusion, our results demonstrate autophagy inhibitor combined targeting MEK and CDK4/6 that concurrently block multiple metabolic processes may be an effective therapeutic approach for gastric cancer.

Frontiers and future of immunotherapy for pancreatic cancer: from molecular mechanisms to clinical application

Pancreatic cancer is a highly aggressive malignant tumor, that is becoming increasingly common in recent years. Despite advances in intensive treatment modalities including surgery, radiotherapy, biological therapy, and targeted therapy, the overall survival rate has not significantly improved in patients with pancreatic cancer. This may be attributed to the insidious onset, unknown pathophysiology, and poor prognosis of the disease. It is therefore essential to identify and develop more effective and safer treatments for pancreatic cancer. Tumor immunotherapy is the new and fourth pillar of anti-tumor therapy after surgery, radiotherapy, and chemotherapy. Significant progress has made in the use of immunotherapy for a wide variety of malignant tumors in recent years; a breakthrough has also been made in the treatment of pancreatic cancer. This review describes the advances in immune checkpoint inhibitors, cancer vaccines, adoptive cell therapy, oncolytic virus, and matrix-depletion therapies for the treatment of pancreatic cancer. At the same time, some new potential biomarkers and potential immunotherapy combinations for pancreatic cancer are discussed. The molecular mechanisms of various immunotherapies have also been elucidated, and their clinical applications have been highlighted. The current challenges associated with immunotherapy and proposed strategies that hold promise in overcoming these limitations have also been discussed, with the aim of offering new insights into immunotherapy for pancreatic cancer.

Activation of endogenous retroviruses and induction of viral mimicry by MEK1/2 inhibition in pancreatic cancer

While pancreatic ductal adenocarcinomas (PDACs) are addicted to KRAS-activating mutations, inhibitors of downstream KRAS effectors, such as the MEK1/2 kinase inhibitor trametinib, are devoid of therapeutic effects. However, the extensive rewiring of regulatory circuits driven by the attenuation of the KRAS pathway may induce vulnerabilities of therapeutic relevance. An in-depth molecular analysis of the transcriptional and epigenomic alterations occurring in PDAC cells in the initial hours after MEK1/2 inhibition by trametinib unveiled the induction of endogenous retroviruses (ERVs) escaping epigenetic silencing, leading to the production of double-stranded RNAs and the increased expression of interferon (IFN) genes. We tracked ERV activation to the early induction of the transcription factor ELF3, which extensively bound and activated nonsilenced retroelements and synergized with IRF1 (interferon regulatory factor 1) in the activation of IFNs and IFN-stimulated genes. Trametinib-induced viral mimicry in PDAC may be exploited in the rational design of combination therapies in immuno-oncology.

Pancreatic Cancer Treatment Targeting the HGF/c-MET Pathway: The MEK Inhibitor Trametinib

Pancreatic cancer is characterized by fibrosis/desmoplasia in the tumor microenvironment, which is primarily mediated by pancreatic stellate cells and cancer-associated fibroblasts. HGF/c-MET signaling, which is instrumental in embryonic development and wound healing, is also implicated for its mitogenic and motogenic properties. In pancreatic cancer, this pathway, along with its downstream signaling pathways, is associated with disease progression, prognosis, metastasis, chemoresistance, and other tumor-related factors. Other features of the microenvironment in pancreatic cancer with the HGF/c-MET pathway include hypoxia, angiogenesis, metastasis, and the urokinase plasminogen activator positive feed-forward loop. All these attributes critically influence the initiation, progression, and metastasis of pancreatic cancer. Therefore, targeting the HGF/c-MET signaling pathway appears promising for the development of innovative drugs for pancreatic cancer treatment. One of the primary downstream effects of c-MET activation is the MAPK/ERK (Ras, Ras/Raf/MEK/ERK) signaling cascade, and MEK (Mitogen-activated protein kinase kinase) inhibitors have demonstrated therapeutic value in RAS-mutant melanoma and lung cancer. Trametinib is a selective MEK1 and MEK2 inhibitor, and it has evolved as a pivotal therapeutic agent targeting the MAPK/ERK pathway in various malignancies, including BRAF-mutated melanoma, non-small cell lung cancer and thyroid cancer. The drug's effectiveness increases when combined with agents like BRAF inhibitors. However, resistance remains a challenge, necessitating ongoing research to counteract the resistance mechanisms. This review offers an in-depth exploration of the HGF/c-MET signaling pathway, trametinib's mechanism, clinical applications, combination strategies, and future directions in the context of pancreatic cancer.

Proteomic study on nintedanib in gastric cancer cells

Background

Gastric cancer is a very common gastrointestinal tumor with a high mortality rate. Nintedanib has been shown to significantly reduce tumor cell proliferation and increase apoptosis in gastric cancer cells in vitro. However, its systemic action mechanism on gastric cancer cells remains unclear. A high-throughput proteomic approach should help identify the potential mechanisms and targets of nintedanib on gastric cancer cells.

Methods

The effects of nintedanib on the biological behavior of gastric cancer cells were evaluated. A cytotoxic proliferation assay was performed to estimate the half maximal inhibitory concentration (IC50). AGS cells were divided into control, and nintedanib-treated groups (5 µM, 48 h), and differential protein expression was investigated using tandem mass tags (TMT) proteomics. The molecular mechanisms of these differentially expressed proteins and their network interactions were then analyzed using bioinformatics, and potential nintedanib targets were identified.

Results

This study identified 845 differentially expressed proteins in the nintedanib-treated group (compared to the control group), comprising 526 up-regulated and 319 down-regulated proteins. Bioinformatics analysis revealed that the differentially expressed proteins were primarily enriched in biological pathways for branched-chain amino acid metabolism, steroid biosynthesis, propionate metabolism, fatty acid metabolism, lysosome, peroxisome, and ferroptosis. Key driver analysis revealed that proteins, such as enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH), isocitrate dehydrogenase 1 (IDH1), acyl-CoA oxidase 1 (ACOX1), acyl-CoA oxidase 2 (ACOX2), acyl-CoA oxidase 3 (ACOX3), and acetyl-CoA acyltransferase 1 (ACAA1) could be linked with nintedanib action.

Conclusion

Nintedanib inhibits the proliferation, invasion, and metastasis of gastric cancer cells. The crossover pathways and protein networks predicted by proteomics should provide more detailed molecular information enabling the use of nintedanib against gastric cancer.

A prognostic marker LTBP1 is associated with epithelial mesenchymal transition and can promote the progression of gastric cancer

LTBP1 is closely related to TGF-β1 function as an essential component, which was unclear in gastric cancer (GC). Harbin Medical University (HMU)-GC cohort and The Cancer Genome Atlas (TCGA) dataset were combined to form a training cohort to calculate the connection between LTBP1 mRNA expression, prognosis and clinicopathological features. The training cohort was also used to verify the biological function of LTBP1 and its relationship with immune microenvironment and chemosensitivity. In the tissue microarrays (TMAs), immunohistochemical (IHC) staining was performed to observe LTBP1 protein expression. The correlation between LTBP1 protein expression level and prognosis was also analyzed, and a nomogram model was constructed. Western blotting (WB) was used in cell lines to assess LTBP1 expression. Transwell assays and CCK-8 were employed to assess LTBP1's biological roles. In compared to normal gastric tissues, LTBP1 expression was upregulated in GC tissues, and high expression was linked to a bad prognosis for GC patients. Based on a gene enrichment analysis, LTBP1 was primarily enriched in the TGF-β and EMT signaling pathways. Furthermore, high expression of LTBP1 in the tumor microenvironment was positively correlated with an immunosuppressive response. We also found that LTBP1 expression (p = 0.006) and metastatic lymph node ratio (p = 0.044) were independent prognostic risk factors for GC patients. The prognostic model combining LTBP1 expression and lymph node metastasis ratio reliably predicted the prognosis of GC patients. In vitro proliferation and invasion of MKN-45 GC cells were inhibited and their viability was decreased by LTBP1 knockout. LTBP1 plays an essential role in the development and progression of GC, and is a potential prognostic biomarker and therapeutic target for GC.

CRISPRing KRAS: A Winding Road with a Bright Future in Basic and Translational Cancer Research

Once considered "undruggable" due to the strong affinity of RAS proteins for GTP and the structural lack of a hydrophobic "pocket" for drug binding, the development of proprietary therapies for KRAS-mutant tumors has long been a challenging area of research. CRISPR technology, the most successful gene-editing tool to date, is increasingly being utilized in cancer research. Here, we provide a comprehensive review of the application of the CRISPR system in basic and translational research in KRAS-mutant cancer, summarizing recent advances in the mechanistic understanding of KRAS biology and the underlying principles of drug resistance, anti-tumor immunity, epigenetic regulatory networks, and synthetic lethality co-opted by mutant KRAS.

Tumor immune microenvironment-based therapies in pancreatic ductal adenocarcinoma: time to update the concept

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal solid tumors. The tumor immune microenvironment (TIME) formed by interactions among cancer cells, immune cells, cancer-associated fibroblasts (CAF), and extracellular matrix (ECM) components drives PDAC in a more immunosuppressive direction: this is a major cause of therapy resistance and poor prognosis. In recent years, research has advanced our understanding of the signaling mechanism by which TIME components interact with the tumor and the evolution of immunophenotyping. Through revolutionary technologies such as single-cell sequencing, we have gone from simply classifying PDACs as "cold" and "hot" to a more comprehensive approach of immunophenotyping that considers all the cells and matrix components. This is key to improving the clinical efficacy of PDAC treatments. In this review, we elaborate on various TIME components in PDAC, the signaling mechanisms underlying their interactions, and the latest research into PDAC immunophenotyping. A deep understanding of these network interactions will contribute to the effective combination of TIME-based therapeutic approaches, such as immune checkpoint inhibitors (ICI), adoptive cell therapy, therapies targeting myeloid cells, CAF reprogramming, and stromal normalization. By selecting the appropriate integrated therapies based on precise immunophenotyping, significant advances in the future treatment of PDAC are possible.

How does TCR-T cell therapy exhibit a superior anti-tumor efficacy

TCR-engineered T cells have achieved great progress in solid tumor therapy, some of which have been applicated in clinical trials. Deep knowledge about the current progress of TCR-T in tumor therapy would be beneficial to understand the direction. Here, we classify tumor antigens into tumor-associated antigens, tumor-specific antigens, tumor antigens expressed by oncogenic viruses, and tumor antigens caused by abnormal protein modification; Then we detail the TCR-T cell therapy effects targeting those tumor antigens in clinical or preclinical trials, and propose that neoantigen specific TCR-T cell therapy is expected to be a promising approach for solid tumors; Furthermore, we summarize the optimization strategies, such as tumor microenvironment, TCR pairing and affinity, to improve the therapeutic effect of TCR-T. Overall, this review provides inspiration for the antigen selection and therapy strategies of TCR-T in the future.

Single-cell sequencing in pancreatic cancer research: A deeper understanding of heterogeneity and therapy

Pancreatic cancer, including pancreatic ductal adenocarcinomas (PDACs), is a malignant tumor with characteristics of tumor-stroma interactions. Patients often have a poor prognosis and a poor long-term survival rate. In recent years, rapidly-developing single-cell sequencing techniques have been used to analyze cell populations at a single-cell resolution, so that it is now possible to have a more in-depth and clearer understanding of the genetic composition of pancreatic cancer. In this review, we provide an overview of the current single-cell sequencing techniques and their applications in the exploration of intratumoral heterogeneity, the tumor microenvironment, therapy resistance, and novel treatments. Our hope is to provide new insight into the potential of precision therapy, which will perhaps one day lead to significant advances in PDAC treatment.

Sono-Activatable Semiconducting Polymer Nanoreshapers Multiply Remodel Tumor Microenvironment for Potent Immunotherapy of Orthotopic Pancreatic Cancer

Due to the complicated tumor microenvironment that compromises the efficacies of various therapies, the effective treatment of pancreatic cancer remains a big challenge. Sono-activatable semiconducting polymer nanoreshapers (SPNDN H) are constructed to multiply remodel tumor microenvironment of orthotopic pancreatic cancer for potent immunotherapy. SPNDN H contain a semiconducting polymer, hydrogen sulfide (H2 S) donor, and indoleamine 2,3-dioxygenase (IDO) inhibitor (NLG919), which are encapsulated by singlet oxygen (1 O2 )-responsive shells with modification of hyaluronidase (HAase). After accumulation in orthotopic pancreatic tumor sites, SPNDN H degrade the major content of tumor microenvironment hyaluronic acid to promote nanoparticle enrichment and immune cell infiltration, and also release H2 S to relieve tumor hypoxia via inhibiting mitochondrion functions. Moreover, the relieved hypoxia enables amplified sonodynamic therapy (SDT) under ultrasound (US) irradiation with generation of 1 O2 , which leads to immunogenic cell death (ICD) and destruction of 1 O2 -responsive components to realize sono-activatable NLG919 release for reversing IDO-based immunosuppression. Through such a multiple remodeling mechanism, a potent antitumor immunological effect is triggered after SPNDN H-based treatment. Therefore, the growths of orthotopic pancreatic tumors in mouse models are almost inhibited and tumor metastases are effectively restricted. This study offers a sono-activatable nanoplatform to multiply remodel tumor microenvironment for effective and precise immunotherapy of deep-tissue orthotopic tumors.

Breaking the mold: Overcoming resistance to immune checkpoint inhibitors

Immune checkpoint blockade-based therapies are effective against a sorts of cancers. However, drug resistance is a problem that cannot be ignored. This review intends to elucidate the mechanisms underlying drug tolerance induced by PD-1/PD-L1 inhibitors, as well as to outline proposed mechanism-based combination therapies and small molecule drugs that target intrinsic immunity and immune checkpoints. According to the differences of patients and types of cancer, the optimization of individualized combination therapy will help to enhance PD-1/PD-L1-mediated immunoregulation, reduce chemotherapy resistance, and provide new ideas for chemotherapy-resistant cancer.

Hydrogel-Based Therapeutics for Pancreatic Ductal Adenocarcinoma Treatment

Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest malignancies worldwide, is characteristic of the tumor microenvironments (TME) comprising numerous fibroblasts and immunosuppressive cells. Conventional therapies for PDAC are often restricted by limited drug delivery efficiency, immunosuppressive TME, and adverse effects. Thus, effective and safe therapeutics are urgently required for PDAC treatment. In recent years, hydrogels, with their excellent biocompatibility, high drug load capacity, and sustainable release profiles, have been developed as effective drug-delivery systems, offering potential therapeutic options for PDAC. This review summarizes the distinctive features of the immunosuppressive TME of PDAC and discusses the application of hydrogel-based therapies in PDAC, with a focus on how these hydrogels remodel the TME and deliver different types of cargoes in a controlled manner. Furthermore, we also discuss potential drug candidates and the challenges and prospects for hydrogel-based therapeutics for PDAC. By providing a comprehensive overview of hydrogel-based therapeutics for PDAC treatment, this review seeks to serve as a reference for researchers and clinicians involved in developing therapeutic strategies targeting the PDAC microenvironment.

RAS signaling and immune cells: a sinister crosstalk in the tumor microenvironment

The rat sarcoma virus (RAS) gene is the most commonly mutated oncogene in cancer, with about 19% of cancer patients carrying RAS mutations. Studies on the interaction between RAS mutation and tumor immune microenvironment (TIM) have been flourishing in recent years. More and more evidence has proved that RAS signals regulate immune cells' recruitment, activation, and differentiation while assisting tumor cells to evade immune surveillance. This review concluded the direct and indirect treatment strategies for RAS mutations. In addition, we updated the underlying mechanisms by which RAS signaling modulated immune infiltration and immune escape. Finally, we discussed advances in RAS-targeted immunotherapies, including cancer vaccines and adoptive cell therapies, with a particular focus on combination strategies with personalized therapy and great potential to achieve lasting clinical benefits.

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.

Dual Recombinase-Based Mouse Models Help Decipher Cancer Biology and Targets for Therapy

The advent of next-generation sequencing (NGS) and single-cell profiling technologies has revealed the complex and heterogenous ecosystem of human tumors under steady-state and therapeutic perturbation. Breakthroughs in the development of genetically engineered mouse models (GEMM) of human cancers that are based on the combination of two site-specific recombinase systems [dual-recombinase system (DRS)] offer fundamental new possibilities to elucidate and understand critical drivers of the diverse tumor phenotypes and validate potential targets for therapy. Here, we discuss opportunities DRS-based cancer GEMMs offer to model, trace, manipulate, and functionally investigate established cancers, their interactions with the host, and their response to therapy.

Potential drug-drug interactions with mitogen-activated protein kinase (MEK) inhibitors used to treat melanoma

INTRODUCTION

The management of patients with BRAF-mutated advanced melanoma who are undergoing targeted therapy with MEK inhibitors can be complicated by the co-administration of multiple medications, which can give rise to drug-drug interactions of clinical significance.

COVERED AREAS

Our review presents a comprehensive analysis of the pharmacokinetic and pharmacodynamic interactions of the three approved for advanced melanoma MEK inhibitor drugs - binimetinib, cobimetinib, and trametinib. MEDLINE (PubMed) was utilized for the literature search, comprising clinical studies, observational studies, and preclinical research. The review discusses the impact of these interactions on efficacy and safety of the treatments and differentiates between interactions supported by pharmacokinetic or pharmacodynamic mechanisms, those encountered in clinical practice, and those observed in preclinical studies.

EXPERT OPINION

Physicians should be aware about potential benefits, but also increased toxicity caused by drug interactions between MEK inhibitors and other drugs in the management of patients with metastatic melanoma.

Therapy-associated remodeling of pancreatic cancer revealed by single-cell spatial transcriptomics and optimal transport analysis

In combination with cell intrinsic properties, interactions in the tumor microenvironment modulate therapeutic response. We leveraged high-plex single-cell spatial transcriptomics to dissect the remodeling of multicellular neighborhoods and cell-cell interactions in human pancreatic cancer associated with specific malignant subtypes and neoadjuvant chemotherapy/radiotherapy. We developed Spatially Constrained Optimal Transport Interaction Analysis (SCOTIA), an optimal transport model with a cost function that includes both spatial distance and ligand-receptor gene expression. Our results uncovered a marked change in ligand-receptor interactions between cancer-associated fibroblasts and malignant cells in response to treatment, which was supported by orthogonal datasets, including an ex vivo tumoroid co-culture system. Overall, this study demonstrates that characterization of the tumor microenvironment using high-plex single-cell spatial transcriptomics allows for identification of molecular interactions that may play a role in the emergence of chemoresistance and establishes a translational spatial biology paradigm that can be broadly applied to other malignancies, diseases, and treatments.

Phosphoproteomics guides effective low-dose drug combinations against pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a limited set of known driver mutations but considerable cancer cell heterogeneity. Phosphoproteomics provides a readout of aberrant signaling and has the potential to identify new targets and guide treatment decisions. Using two-step sequential phosphopeptide enrichment, we generate a comprehensive phosphoproteome and proteome of nine PDAC cell lines, encompassing more than 20,000 phosphosites on 5,763 phospho-proteins, including 316 protein kinases. By using integrative inferred kinase activity (INKA) scoring, we identify multiple (parallel) activated kinases that are subsequently matched to kinase inhibitors. Compared with high-dose single-drug treatments, INKA-tailored low-dose 3-drug combinations against multiple targets demonstrate superior efficacy against PDAC cell lines, organoid cultures, and patient-derived xenografts. Overall, this approach is particularly more effective against the aggressive mesenchymal PDAC model compared with the epithelial model in both preclinical settings and may contribute to improved treatment outcomes in PDAC patients.

Gradient Tumor Microenvironment-Promoted Penetrating Micelles for Hypoxia Relief and Immunosuppression Reversion in Pancreatic Cancer Treatment

The tumor microenvironment of pancreatic ductal adenocarcinoma (PDAC) is the main block for the penetration of chemotherapy. In the tumor microenvironment, a dense matrix composed of fibrin is formed on the exterior, while the interior is featured by high reduction, hypoxia and low pH. How to match the special microenvironment to on-demand drug release is the key to improve chemotherapeutic efficacy. Herein, a microenvironment-responsive micellar system is developed to deepen tumoral penetration. Briefly, the conjugation of a fibrin-targeting peptide to PEG-poly amino acid has been utilized to achieve accumulation of micelles in the tumor stroma. By modification of micelles with hypoxia-reducible nitroimidazole which becomes protonated under acidic conditions, their surface charge is more positive, facilitating deeper penetration into tumors. Paclitaxel was loaded onto the micelles via a disulfide bond to enable glutathione (GSH)-responsive release. Therefore, the immunosuppressive microenvironment is relived through the alleviation of hypoxia and depletion of GSH. Hopefully, this work could establish paradigms by designing sophisticated drug-delivery systems to tactfully employ and retroact the tamed tumoral microenvironment to improve the therapeutic efficacy based on understanding the multiple hallmarks and learning the mutual regulation. STATEMENT OF SIGNIFICANCE: : Tumor microenvironment(TME) is an unique pathological feature of pancreatic cancer and an inherent barrier to chemotherapy. Numerous studies regard TME as the targets for drug delivery. In this work, we propose a hypoxia-responsive nanomicellar drug delivery system that aiming hypoxia TME of pancreatic cancer. The nanodrug delivery system could respond to the hypoxic microenvironment and enhance the penetration of the inner tumor at the same time preserving the outer tumor stroma, thus achieving targeted treatment of PDAC by preserving the integrity of the outer stroma. Simultaneously, the responsive group can reverse the degree of hypoxia in TME by disrupting the redox balance in the tumor region, thus achieving precise treatment of PDAC by matching the pathological characteristics of TME. We believe our article would provide new design ideas for the future treatments for pancreatic cancer.

Nano-Econazole Enhanced PD-L1 Checkpoint Blockade for Synergistic Antitumor Immunotherapy against Pancreatic Ductal Adenocarcinoma

Insufficienct T lymphocyte infiltration and unresponsiveness to immune checkpoint blockade therapy are still major difficulties for the clinical treatment of pancreatic ductal adenocarcinoma (PDAC). Although econazole has shown promise in inhibiting PDAC growth, its poor bioavailability and water solubility limit its potential as a clinical therapy for PDAC. Furthermore, the synergistic role of econazole and biliverdin in immune checkpoint blockade therapy in PDAC remains elusive and challenging. Herein, a chemo-phototherapy nanoplatform is designed by which econazole and biliverdin can be co-assembled (defined as FBE NPs), which significantly improve the poor water solubility of econazole and enhance the efficacy of PD-L1 checkpoint blockade therapy against PDAC. Mechanistically, econazole and biliverdin are directly released into the acidic cancer microenvironment, to activate immunogenic cell death via biliverdin-induced PTT/PDT and boost the immunotherapeutic response of PD-L1 blockade. In addition, econazole simultaneously enhances PD-L1 expression to sensitize anti-PD-L1 therapy, leading to suppression of distant tumors, long-term immune memory effects, improved dendritic cell maturation, and tumor infiltration of CD8⁺ T lymphocytes. The combined FBE NPs and α-PDL1 show synergistic antitumor efficacy. Collectively, FBE NPs show excellent biosafety and antitumor efficacy by combining chemo-phototherapy with PD-L1 blockade, which has promising potential in a precision medicine approach as a PDAC treatment strategy.

Targeting MFAP5 in cancer-associated fibroblasts sensitizes pancreatic cancer to PD-L1-based immunochemotherapy via remodeling the matrix

Highly desmoplastic and immunosuppressive tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) contributes to tumor progression and resistance to current therapies. Clues targeting the notorious stromal environment have offered hope for improving therapeutic response whereas the underlying mechanism remains unclear. Here, we find that prognostic microfibril associated protein 5 (MFAP5) is involved in activation of cancer-associated fibroblasts (CAFs). Inhibition of MFAP5^highCAFs shows synergistic effect with gemcitabine-based chemotherapy and PD-L1-based immunotherapy. Mechanistically, MFAP5 deficiency in CAFs downregulates HAS2 and CXCL10 via MFAP5/RCN2/ERK/STAT1 axis, leading to angiogenesis, hyaluronic acid (HA) and collagens deposition reduction, cytotoxic T cells infiltration, and tumor cells apoptosis. Additionally, in vivo blockade of CXCL10 with AMG487 could partially reverse the pro-tumor effect from MFAP5 overexpression in CAFs and synergize with anti-PD-L1 antibody to enhance the immunotherapeutic effect. Therefore, targeting MFAP5^highCAFs might be a potential adjuvant therapy to enhance the immunochemotherapy effect in PDAC via remodeling the desmoplastic and immunosuppressive microenvironment.

Cell-selective proteomics segregates pancreatic cancer subtypes by extracellular proteins in tumors and circulation

Cell-selective proteomics is a powerful emerging concept to study heterocellular processes in tissues. However, its high potential to identify non-cell-autonomous disease mechanisms and biomarkers has been hindered by low proteome coverage. Here, we address this limitation and devise a comprehensive azidonorleucine labeling, click chemistry enrichment, and mass spectrometry-based proteomics and secretomics strategy to dissect aberrant signals in pancreatic ductal adenocarcinoma (PDAC). Our in-depth co-culture and in vivo analyses cover more than 10,000 cancer cell-derived proteins and reveal systematic differences between molecular PDAC subtypes. Secreted proteins, such as chemokines and EMT-promoting matrisome proteins, associated with distinct macrophage polarization and tumor stromal composition, differentiate classical and mesenchymal PDAC. Intriguingly, more than 1,600 cancer cell-derived proteins including cytokines and pre-metastatic niche formation-associated factors in mouse serum reflect tumor activity in circulation. Our findings highlight how cell-selective proteomics can accelerate the discovery of diagnostic markers and therapeutic targets in cancer.

Tumor and Stromal Cell Targeting with Nintedanib and Alpelisib Overcomes Intrinsic Bladder Cancer Resistance

Bladder cancer is a highly prevalent tumor, requiring the urgent development of novel therapies, especially for locally advanced and metastatic disease. Nintedanib is a potent antifibrotic angio-kinase inhibitor, which has shown clinical efficacy in combination with chemotherapy in patients with locally advanced muscle-invasive bladder cancer. Nintedanib inhibits fibroblast growth factor receptors (FGFRs), validated targets in patients with bladder cancer harboring FGFR3/2 genetic alterations. Here, we aimed at studying its mechanisms of action to understand therapy resistance, identify markers predictive of response, and improve the design of future clinical trials. We have used a panel of genetically well-characterized human bladder cancer cells to identify the molecular and transcriptomic changes induced upon treatment with nintedanib, in vitro and in vivo, at the tumor and stroma cell levels. We showed that bladder cancer cells display an intrinsic resistance to nintedanib treatment in vitro, independently of their FGFR3 status. However, nintedanib has higher antitumor activity on mouse xenografts. We have identified PI3K activation as a resistance mechanism against nintedanib in bladder cancer and evidenced that the combination of nintedanib with the PI3K inhibitor alpelisib has synergistic antitumor activity. Treatment with this combination is associated with cell-cycle inhibition at the tumoral and stromal levels and potent nontumor cell autonomous effects on α-smooth muscle actin-positive tumor infiltrating cells and tumor vasculature. The combination of nintedanib with PI3K inhibitors not only reversed bladder cancer resistance to nintedanib but also enhanced its antiangiogenic effects.

Single-cell profiling to explore pancreatic cancer heterogeneity, plasticity and response to therapy

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer entity characterized by a heterogeneous genetic landscape and an immunosuppressive tumor microenvironment. Recent advances in high-resolution single-cell sequencing and spatial transcriptomics technologies have enabled an in-depth characterization of both malignant and host cell types and increased our understanding of the heterogeneity and plasticity of PDAC in the steady state and under therapeutic perturbation. In this Review we outline single-cell analyses in PDAC, discuss their implications on our understanding of the disease and present future perspectives of multimodal approaches to elucidate its biology and response to therapy at the single-cell level.

The Network Zoo: a multilingual package for the inference and analysis of gene regulatory networks

Inference and analysis of gene regulatory networks (GRNs) require software that integrates multi-omic data from various sources. The Network Zoo (netZoo; netzoo.github.io) is a collection of open-source methods to infer GRNs, conduct differential network analyses, estimate community structure, and explore the transitions between biological states. The netZoo builds on our ongoing development of network methods, harmonizing the implementations in various computing languages and between methods to allow better integration of these tools into analytical pipelines. We demonstrate the utility using multi-omic data from the Cancer Cell Line Encyclopedia. We will continue to expand the netZoo to incorporate additional methods.