Histamine regulation of pancreatitis and pancreatic cancer: a review of recent findings

Putative function and prognostic molecular marker of mast cells in colorectal cancer

BACKGROUND

The increased demand for markers for colorectal cancer (CRC) highlights the importance of investigating immune cells involved in CRC progression. This study aims to dissect the mast cells in CRC, characterize the role of mast cells in CRC development, coordinate molecular communication between mast cells and malignant cells, and construct and validate a prognostic classification model based on mast cell markers.

METHODS

Single-cell transcriptome data of CRC patients were extracted from GSE146771 for cell classification and annotation. The malignant cells were identified by copykat and the communication between mast cells and malignant cells was analyzed by CellChat. Least absolute shrinkage and selection operator (LASSO) regression analysis and Cox regression analysis of mast cell markers were performed in the TCGA-COAD cohort to construct a prognostic classification model. qRT-PCR was performed to detect the mRNA expression of the molecules in the classification model in P815 and MC-9 cells. The co-culture experiment of MC38 and P815 cells were performed in 12-well transwell dish. Wound healing assay and Transwell assay were performed to detect cell migration and invasion.

RESULTS

10,186 high-quality cells in GSE146771 were annotated to 9 cell types. Six markers in mast cells (HDC, GATA2, ASAH1, BTBD19, TIMP1, FAM110A) were selected to construct a classification model. The high-risk score defined showed high infiltration of immunosuppressive cells, including endothelial cells, CAFs, Tregs and high angiogenesis and epithelial-mesenchymal transition (EMT) activities. In the model, HDC were abnormally low expressed in P815 cells, while BTBD19, FAM110A, GATA2, ASAH1 and TIMP1 showed excessive expression in P815 cells. Knockdown of GATA2 in the co-culture system of P815 and MC38 cells blocked cell migration and invasion.

CONCLUSION

This study identified the cell types within CRC, elaborated the cellular functions of mast cells in CRC development and their molecular communication to coordinate malignant cells, and highlighted the molecular components and biological features that constitute promising prognostic classification model.

Machine learning model reveals the risk, prognosis, and drug response of histamine-related signatures in pancreatic cancer

BACKGROUND

Histamine, a critical inflammatory mediator, is generated by both mast cells and specific tumor cells, and it plays a fundamental role in inflammatory and immune responses. In the current scientific landscape, histamine-related genes (HRGs) and their associated pathways have been validated to be implicated in the development and advancement of cancer. However, the precise role of HRGs in gauging the risk and predicting the prognosis of pancreatic adenocarcinoma (PAAD) remains nebulous.

METHODS

We carried out an elaborate data collection endeavor. Transcriptome data along with pertinent clinical information were obtained from the GSE28735, GSE62452, and TCGA-PAAD cohorts. GWAS data were retrieved from the FinnGen Release 11 and eQTLGen databases. For the drug-target Mendelian randomization (MR) analysis, the "TwoSampleMR" (version 0.5.6) R package was employed. The random survival forest (RSF) model was analyzed using the "randomForestSRC (rfsrc)" R package and further elucidated with the help of the "mlr3" package. Somatic mutation analysis and immune infiltration investigations were conducted by means of the "maftools" (v. 2.12.0) R package and "pRRophetic" R software package, respectively. Targeted drug sensitivity analysis was executed using the "oncopredict" and "parallel" packages.

RESULTS

Through a meticulous drug-targeted MR analysis and an exhaustive exploration of transcriptome databases (including 2 GSE combat and TCGA cohort), 20 upregulated differentially expressed genes (DEGs) were identified. The RSF model emerged as the optimal choice, and a 9-HRGs signature was selected to construct a prognostic model that boasted an average C-index of 0.777. In the training and validation cohorts, the model exhibited remarkable predictive prowess, with 1-, 2-, and 3-year prediction accuracies of 0.898, 0.932, and 0.922 in the training set, and 0.909, 0.974, and 0.962 in the validation set, respectively. A higher HRG score was found to correlate with adverse events and the N1 stage. Additionally, it was associated with an increase in M0 macrophages and a decline in CD8 + T cell function. For patients with a low HRG score, several commonly used chemotherapeutic agents, namely Gemcitabine, Carboplatin, Sorafenib, and Oxaliplatin, were more efficacious.

CONCLUSION

The HRG signature holds the potential to serve as effective biomarkers for diagnosing, predicting the prognosis, and assessing the sensitivity to chemotherapy in PAAD.

H1 Antihistamines-Promising Candidates for Repurposing in the Context of the Development of New Therapeutic Approaches to Cancer Treatment

Despite significant progress in the field of clinical oncology in terms of diagnostic and treatment methods, the results of anticancer therapy are still not fully satisfactory, especially due to limited response and high toxicity. This has forced the need for further research to finding alternative ways to improve success rates in oncological treatment. A good solution to this problem in the context of rapidly obtaining an effective drug that works on multiple levels of cancer and is also safe is the global strategy of repurposing an existing drug. Research into other applications of an existing drug enables a precise assessment of its possible mechanisms of action and, consequently, the broadening of therapeutic indications. This strategy is also supported by the fact that most non-oncological drugs have pleiotropic effects, and most of the diseases for which they were originally intended are multifactorial, which in turn is a very desirable phenomenon due to the heterogeneous and multifaceted biology of cancer. In this review, we will mainly focus on the anticancer potential of H1 antihistamines, especially the new generation that were not originally intended for cancer therapy, to highlight the relevant signaling pathways and discuss the properties of these agents for their judicious use based on the characteristic features of cancer.

Synergistic effects of agonists and two-pore-domain potassium channels on secretory responses of human pancreatic duct cells Capan-1

Mechanisms of synergistic agonist stimulation and modulation of the electrochemical driving force for anion secretion are still not fully explored in human pancreatic duct epithelial cells. The first objective of this study was therefore to test whether combined agonist stimulation augments anion transport responses in the Capan-1 monolayer model of human pancreatic duct epithelium. The second objective was to test the influence of H⁺,K⁺-ATPase inhibition on anion transport in Capan-1 monolayers. The third objective was to analyze the expression and function of K⁺ channels in Capan-1, which could support anion secretion and cooperate with H⁺,K⁺-ATPases in pH and potassium homeostasis. The human pancreatic adenocarcinoma cell line Capan-1 was cultured conventionally or as polarized monolayers that were analyzed by Ussing chamber electrophysiological recordings. Single-cell intracellular calcium was assayed with Fura-2. mRNA isolated from Capan-1 was analyzed by use of the nCounter assay or RT-PCR. Protein expression was assessed by immunofluorescence and western blot analyses. Combined stimulation with different physiological agonists enhanced anion transport responses compared to single agonist stimulation. The responsiveness of Capan-1 cells to histamine was also revealed in these experiments. The H⁺,K⁺-ATPase inhibitor omeprazole reduced carbachol- and riluzole-induced anion transport responses. Transcript analyses revealed abundant TASK-2, TWIK-1, TWIK-2, TASK-5, K_Ca3.1, and KCNQ1 mRNA expression. KCNE1 mRNA and TREK-1, TREK-2, TASK-2, and KCNQ1 protein expression were also shown. This study shows that the Capan-1 model recapitulates key physiological aspects of a bicarbonate-secreting epithelium and constitutes a valuable model for functional studies on human pancreatic duct epithelium.

Shedding Light on the Role of Neurotransmitters in the Microenvironment of Pancreatic Cancer

Pancreatic cancer (PC) is a highly lethal malignancy with a 5-year survival rate of less than 8%. The fate of PC is determined not only by the malignant behavior of the cancer cells, but also by the surrounding tumor microenvironment (TME), consisting of various cellular (cancer cells, immune cells, stromal cells, endothelial cells, and neurons) and non-cellular (cytokines, neurotransmitters, and extracellular matrix) components. The pancreatic TME has the unique characteristic of exhibiting increased neural density and altered microenvironmental concentration of neurotransmitters. The neurotransmitters, produced by both neuron and non-neuronal cells, can directly regulate the biological behavior of PC cells via binding to their corresponding receptors on tumor cells and activating the intracellular downstream signals. On the other hand, the neurotransmitters can also communicate with other cellular components such as the immune cells in the TME to promote cancer growth. In this review, we will summarize the pleiotropic effects of neurotransmitters on the initiation and progression of PC, and particularly discuss the emerging mechanisms of how neurotransmitters influence the innate and adaptive immune responses in the TME in an autocrine or paracrine manner. A better understanding of the interplay between neurotransmitters and the immune cells in the TME might facilitate the development of new effective therapies for PC.

MicroRNA-221 induces autophagy through suppressing HDAC6 expression and promoting apoptosis in pancreatic cancer

Pancreatic cancer is an aggressive type of cancer with a poor prognosis, short survival rate and high mortality. Therefore, understanding the molecular mechanism underlying the aggressive growth of pancreatic cancer is of importance. An increasing number of studies suggest that numerous microRNAs (miRNAs/miRs) are associated with the tumorigenesis, progression and prognosis of tumors. In a recent study by the present authors, it was revealed that the expression of miR-221 was significantly downregulated in highly aggressive pancreatic cancer cells compared with weakly aggressive pancreatic cancer cells. In addition, miR-221 has been suggested as a novel tumor-associated miRNA, as it is involved in apoptosis, invasion, metastasis and autophagy of tumor cells. However, the function of miR-221 in pancreatic cancer remains yet to be investigated. In the present study, it was revealed that transfection with miR-221 mimic was able to significantly induce apoptosis and autophagy in pancreatic cancer cells compared with the negative control. The protein deacetylase histone deacetylase-6 (HDAC6) has emerged to be an important component in the cellular management of protein aggregates. Studies suggest that HDAC6 serves a function in the clearance of aggresomes, thereby implying a functional association between HDAC6 and autophagy. In the present study, it was revealed that transfection with miR-221 mimic was able to suppress the protein expression of HDAC6 in pancreatic cancer cells compared with the negative control. Immunofluorescence data suggested that the inhibition of HDAC6 was able to induce autophagy in pancreatic cancer cells. Additionally, the results of the present study suggest that the downregulation of miR-221 expression may serve an oncogenic function in the apoptosis and autophagy of pancreatic cancer cells by inducing the expression of HDAC6.

Mast cells and angiogenesis in pancreatic ductal adenocarcinoma

Mast cells are recognized as critical components of the tumor stromal microenvironment in several solid and hematological malignancies, promoting angiogenesis and tumor growth. A correlation between mast cells infiltration, angiogenesis and tumor progression has been reported for pancreatic ductal adenocarcinoma as well. Mast cells contribute to the aggressiveness of the pancreatic ductal carcinoma enhancing the expression of several pro-angiogenic factors such as vascular endothelial growth factor, fibroblast growth factor-2, platelet-derived growth factor and angiopoietin-1 as well as stimulating the pancreatic cancer cells proliferation by IL-13 and tryptase. The disruption of this pro-angiogenic and proliferative stimulation by inhibiting the mast cells migration and degranulation is under investigation as a potential therapeutic approach in pancreatic ductal adenocarcinoma patients. This review will summarize the literature concerning the mast cells infiltration in the pancreatic ductal adenocarcinoma analyzing its role in angiogenesis and tumor progression.

microRNA-218 promotes gemcitabine sensitivity in human pancreatic cancer cells by regulating HMGB1 expression

OBJECTIVE

The purpose of this study was to examine the effect of gemcitabine (GEM) on microRNA-218 (miR-218) expression in human pancreatic cancer cells.

METHODS

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to examine the differences in miR-218 expression between the GEM-sensitive BxPC-3 pancreatic cancer cells and GEM-resistant PANC-1 cells. The effect of GEM on the expression of miR-218 in PANC-1 cells was also investigated. PANC-1 cells were transfected either with HMGB1 siRNA to knock down the expression of HMGB1 or with the recombinant HMGB1 expression vector (pcDNA3.1-HMGB1) to overexpress HMGB1. The effect of ectopic expression of HMGB1 on the apoptosis of miR-218-transfected and GEM-treated PANC-1 cells was examined by flow cytometric analysis.

RESULTS

The miR-218 expression level was lower in GEM-resistant PANC-1 cells compared to GEM-sensitive BxPC-3 cells (P<0.05). The percentage of apoptotic PANC-1 cells was significantly increased in the miR-218 mimic + GEM group compared to the mimic ctrl + GEM group and the normal control group (P<0.01). The HMGB1 expression level was markedly decreased in PANC-1 cells transfected with HMGB1 siRNA but was significantly increased in PANC-1 cells transfected with the recombinant HMGB1 expression vector, pcDNA3.1-HMGB1 (P<0.01). The proportion of apoptotic PANC-1 cells was significantly lower in the miR-218 mimic + GEM + pcDNA3.1-HMGB1 group compared to the miR-218 mimic + GEM + HMGB1 siRNA group (P<0.01).

CONCLUSIONS

The expression level of miR-218 was downregulated in the GEM-resistant cell line. miR-218 promoted the sensitivity of PANC-1 cells to GEM, which was achieved mainly through regulating the expression of HMGB1 in PANC-1 cells.

microRNA-218 suppresses the proliferation, invasion and promotes apoptosis of pancreatic cancer cells by targeting HMGB1

OBJECTIVE

To detect the expression profiles of microRNA-218 (miR-218) in human pancreatic cancer tissue (PCT) and cells and their effects on the biological features of human pancreatic cancer cell line PANC-1 and observe the effect of miR-218 on the expression of the target gene high mobility group box 1 (HMGB1), with an attempt to provide new treatment methods and strategies for pancreatic cancer.

METHODS

The expressions of miR-218 in PCT and normal pancreas tissue as well as in various pancreatic cancer cell lines including AsPC-1, BxPC-3, and PANC-1 were determined with quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The change of miR-218 expression in PANC-1 cells was detected using qRT-PCT after the transfection of miR-218 mimic for 48 h. Cell Counting Kit-8 (CCK-8) was applied for detecting the effect of miR-218 on the activity of PANC-1 cells. The effects of miR-218 on the proliferation and apoptosis of PANC-1 cells were analyzed using the flow cytometry. The effect of miR-218 on the migration of PANC-1 cells was detected using the Trans-well migration assay. The HMGB1 was found to be a target gene of miR-218 by luciferase reporter assay, and the effect of miR-218 on the expression of HMGB1 protein in cells were determined using Western blotting.

RESULTS

As shown by qRT-PCR, the expressions of miR-218 in PCT and in pancreatic cancer cell line significantly decreased when compared with the normal pancreatic tissue (NPT) (P<0.01). Compared with the control group, the miR-218 expression significantly increased in the PANC-1 group after the transfection of miR-218 mimic for 48 h (P<0.01). Growth curve showed that the cell viability significantly dropped after the overexpression of miR-218 in the PANC-1 cells for two days (P<0.05). Flow cytometry showed that the S-phase fraction significantly dropped after the overexpression of miR-218 (P<0.01) and the percentage of apoptotic cells significantly increased (P<0.01). As shown by the Trans-well migration assay, the enhanced miR-218 expression was associated with a significantly lower number of cells that passed through a Transwell chamber (P<0.01). Luciferase reporter assay showed that, compared with the control group, the relative luciferase activity significantly decreased in the miR-218 mimic group (P<0.01). As shown by the Western blotting, compared with the control group, the HMGB1 protein expression significantly decreased in the PANC-1 group after the transfection of miR-218 mimic for 48 h (P<0.01).

CONCLUSIONS

The miR-218 expression decreases in human PCT and cell lines. miR-218 can negatively regulate the HMGB1 protein expression and inhibit the proliferation and invasion of pancreatic cancer cells. A treatment strategy by enhancing the miR-218 expression may benefit the patients with pancreatic cancer.