The cellular origins of cancer with particular reference to the gastrointestinal tract

Mutant GNAS drives a pyloric metaplasia with tumor suppressive glycans in intraductal papillary mucinous neoplasia

BACKGROUND & AIMS

Intraductal Papillary Mucinous Neoplasms (IPMNs) are cystic lesions and bona fide precursors for pancreatic ductal adenocarcinoma (PDAC). Recent studies have shown that pancreatic precancer is characterized by a transcriptomic program similar to gastric metaplasia. The aims of this study were to assay IPMN for pyloric markers, to identify molecular drivers, and to determine a functional role for this program in the pancreas.

METHODS

Pyloric marker expression was evaluated by RNA-seq and multiplex immunostaining in patient samples. Cell lines and organoids expressing KrasG12D +/- GNASR201C underwent RNA sequencing. A PyScenic-based regulon analysis was performed to identify molecular drivers, and candidates were evaluated by RNA-seq, immunostaining, and small interfering RNA knockdown. Glycosylation profiling was performed to identify GNASR201C-driven changes. Glycan abundance was evaluated in patient samples.

RESULTS

Pyloric markers were identified in human IPMN. GNASR201C drove expression of this program as well as an indolent phenotype characterized by distinct glycosyltransferase changes. Glycan profiling identified an increase in LacdiNAcs and loss of pro-tumorigenic Lewis antigens. Knockdown of transcription factors Spdef or Creb3l1 or chitinase treatment reduced LacdiNAc deposition and reversed the indolent phenotype. LacdiNAc and 3-sulfoLeA/C abundance discriminated low from high grade patient IPMN.

CONCLUSION

GNASR201C drives an indolent phenotype in IPMN by amplifying a differentiated, pyloric phenotype through SPDEF/CREB3L1 which is characterized by distinct glycans. Acting as a glycan rheostat, mutant GNAS elevates LacdiNAcs at the expense of pro-tumorigenic acidic Lewis epitopes, inhibiting cancer cell invasion and disease progression. LacdiNAc and 3-Sulfo-LeA/C are mutually exclusive and may serve as markers of disease progression.

Ion channels in acinar cells in acute pancreatitis: crosstalk of calcium, iron, and copper signals

The initial stages of acute pancreatitis (AP) are characterized by a significant event - acinar ductal metaplasia (ADM). This process is a crucial feature of both acute and chronic pancreatitis, serving as the first step in the development of pancreatic cancer. Ion channels are integral transmembrane proteins that play a pivotal role in numerous biological processes by modulating ion flux. In many diseases, the expression and activity of ion channels are often dysregulated. Metal ions, including calcium ions (Ca2+), ferrous ions (Fe2+), and Copper ions (Cu2+), assume a distinctive role in cellular metabolism. These ions possess specific biological properties relevant to cellular function. However, the interactions among these ions exacerbate the imbalance within the intracellular environment, resulting in cellular damage and influencing the progression of AP. A more in-depth investigation into the mechanisms by which these ions interact with acinar cells is essential for elucidating AP's pathogenesis and identifying novel therapeutic strategies. Currently, treatment for AP primarily focuses on pain relief, complications prevention, and prognosis improvement. There are limited specific treatments targeting acinous cell dedifferentiation or ion imbalance. This study aims to investigate potential therapeutic strategies by examining ion crosstalk within acinar cells in the context of acute pancreatitis.

Screening and validating the optimal panel of housekeeping genes for 4T1 breast carcinoma and metastasis studies in mice

The 4T1 model is extensively employed in murine studies to elucidate the mechanisms underlying the carcinogenesis of triple-negative breast cancer. Molecular biology serves as a cornerstone in these investigations. However, accurate gene expression analyses necessitate data normalization employing housekeeping genes (HKGs) to avert spurious results. Here, we initially delve into the characteristics of the tumor evolution induced by 4T1 in mice, underscoring the imperative for additional tools for tumor monitoring and assessment methods for tracking the animals, thereby facilitating prospective studies employing this methodology. Subsequently, leveraging various software platforms, we assessed ten distinct HKGs (GAPDH, 18 S, ACTB, HPRT1, B2M, GUSB, PGK1, CCSER2, SYMPK, ANKRD17) not hitherto evaluated in the 4T1 breast cancer model, across tumors and diverse tissues afflicted by metastasis. Our principal findings underscore GAPDH as the optimal HKG for gene expression analyses in tumors, while HPRT1 emerged as the most stable in the liver and CCSER2 in the lung. These genes demonstrated consistent expression and minimal variation among experimental groups. Furthermore, employing these HKGs for normalization, we assessed TNF-α and VEGF expression in tissues and discerned significant disparities among groups. We posit that this constitutes the inaugural delineation of an ideal HKG for experiments utilizing the 4T1 model, particularly in vivo settings.

Mitochondrial function and gastrointestinal diseases

Mitochondria are dynamic organelles that function in cellular energy metabolism, intracellular and extracellular signalling, cellular fate and stress responses. Mitochondria of the intestinal epithelium, the cellular interface between self and enteric microbiota, have emerged as crucial in intestinal health. Mitochondrial dysfunction occurs in gastrointestinal diseases, including inflammatory bowel diseases and colorectal cancer. In this Review, we provide an overview of the current understanding of intestinal epithelial cell mitochondrial metabolism, function and signalling to affect tissue homeostasis, including gut microbiota composition. We also discuss mitochondrial-targeted therapeutics for inflammatory bowel diseases and colorectal cancer and the evolving concept of mitochondrial impairment as a consequence versus initiator of the disease.

Cell of Origin of Pancreatic cancer: Novel Findings and Current Understanding

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) stands as one of the most lethal diseases globally, boasting a grim 5-year survival prognosis. The origin cell and the molecular signaling pathways that drive PDAC progression are not entirely understood. This review comprehensively outlines the categorization of PDAC and its precursor lesions, expounds on the creation and utility of genetically engineered mouse models used in PDAC research, compiles a roster of commonly used markers for pancreatic progenitors, duct cells, and acinar cells, and briefly addresses the mechanisms involved in the progression of PDAC. We acknowledge the value of precise markers and suitable tracing tools to discern the cell of origin, as it can facilitate the creation of more effective models for PDAC exploration. These conclusions shed light on our existing understanding of foundational genetically engineered mouse models and focus on the origin and development of PDAC.

Acinar cell carcinoma of gastric ectopic pancreas origin: a case report and literature review

BACKGROUND

Primary pancreatic-type acinar cell carcinoma of the stomach is extremely rare, often misdiagnosed, and of unclear origin.

CASE PRESENTATION

We report the case of a primary pure pancreatic-type acinar cell carcinoma of the stomach in a 58-year-old woman. This is the first reported case to exhibit residual ectopic pancreatic tissue adjacent to the tumor serving as evidence for the origin of the carcinoma. Furthermore, we summarized the clinicopathological features of pancreatic-type acinar cell carcinoma of the stomach in order to further understand this solid tumor.

CONCLUSIONS

Primary pancreatic-type acinar cell carcinoma of the stomach is rare. Data on tumors of this histological type are still relatively scarce, and more in-depth research is needed to elucidate their molecular biological characteristics and prognosis.

COOBoostR: An Extreme Gradient Boosting-Based Tool for Robust Tissue or Cell-of-Origin Prediction of Tumors

We present here COOBoostR, a computational method designed for the putative prediction of the tissue- or cell-of-origin of various cancer types. COOBoostR leverages regional somatic mutation density information and chromatin mark features to be applied to an extreme gradient boosting-based machine-learning algorithm. COOBoostR ranks chromatin marks from various tissue and cell types, which best explain the somatic mutation density landscape of any sample of interest. A specific tissue or cell type matching the chromatin mark feature with highest explanatory power is designated as a potential tissue- or cell-of-origin. Through integrating either ChIP-seq based chromatin data, along with regional somatic mutation density data derived from normal cells/tissue, precancerous lesions, and cancer types, we show that COOBoostR outperforms existing random forest-based methods in prediction speed, with comparable or better tissue or cell-of-origin prediction performance (prediction accuracy-normal cells/tissue: 76.99%, precancerous lesions: 95.65%, cancer cells: 89.39%). In addition, our results suggest a dynamic somatic mutation accumulation at the normal tissue or cell stage which could be intertwined with the changes in open chromatin marks and enhancer sites. These results further represent chromatin marks shaping the somatic mutation landscape at the early stage of mutation accumulation, possibly even before the initiation of precancerous lesions or neoplasia.

A framework for fibrolamellar carcinoma research and clinical trials

Fibrolamellar carcinoma (FLC), a rare, lethal hepatic cancer, occurs primarily in adolescents and young adults. Unlike hepatocellular carcinoma, FLC has no known association with viral, metabolic or chemical agents that cause cirrhosis. Currently, surgical resection is the only treatment demonstrated to achieve cure, and no standard of care exists for systemic therapy. Progress in FLC research illuminates a transition from an obscure cancer to one for which an interactive community seems poised to uncover fundamental mechanisms and initiate translation towards novel therapies. In this Roadmap, we review advances since the seminal discovery in 2014 that nearly all FLC tumours express a signature oncogene (DNAJB1-PRKACA) encoding a fusion protein (DNAJ-PKAc) in which the J-domain of a heat shock protein 40 (HSP40) co-chaperone replaces an amino-terminal segment of the catalytic subunit of the cyclic AMP-dependent protein kinase (PKA). Important gains include increased understanding of oncogenic pathways driven by DNAJ-PKAc; identification of potential therapeutic targets; development of research models; elucidation of immune mechanisms with potential for the development of immunotherapies; and completion of the first multicentre clinical trials of targeted therapy for FLC. In each of these key areas we propose a Roadmap for future progress.

EPHA2-dependent outcompetition of KRASG12D mutant cells by wild-type neighbors in the adult pancreas

As we age, our tissues are repeatedly challenged by mutational insult, yet cancer occurrence is a relatively rare event. Cells carrying cancer-causing genetic mutations compete with normal neighbors for space and survival in tissues. However, the mechanisms underlying mutant-normal competition in adult tissues and the relevance of this process to cancer remain incompletely understood. Here, we investigate how the adult pancreas maintains tissue health in vivo following sporadic expression of oncogenic Kras (KrasG12D), the key driver mutation in human pancreatic cancer. We find that when present in tissues in low numbers, KrasG12D mutant cells are outcompeted and cleared from exocrine and endocrine compartments in vivo. Using quantitative 3D tissue imaging, we show that before being cleared, KrasG12D cells lose cell volume, pack into round clusters, and E-cadherin-based cell-cell adhesions decrease at boundaries with normal neighbors. We identify EphA2 receptor as an essential signal in the clearance of KrasG12D cells from exocrine and endocrine tissues in vivo. In the absence of functional EphA2, KrasG12D cells do not alter cell volume or shape, E-cadherin-based cell-cell adhesions increase and KrasG12D cells are retained in tissues. The retention of KRasG12D cells leads to the early appearance of premalignant pancreatic intraepithelial neoplasia (PanINs) in tissues. Our data show that adult pancreas tissues remodel to clear KrasG12D cells and maintain tissue health. This study provides evidence to support a conserved functional role of EphA2 in Ras-driven cell competition in epithelial tissues and suggests that EphA2 is a novel tumor suppressor in pancreatic cancer.

Expression Analysis of MIST1 and EMT Markers in Primary Tumor Samples Points to MIST1 as a Biomarker of Cervical Cancer

Background

Mist1 is a basic transcription factor, which plays an important role in the development of multiple organs, and may also regulate tumor progression by mediating epithelial-mesenchymal transformation. However, there is lack of research on its role of squamous cell carcinoma, especially in cervical squamous cell carcinoma.

Methods

Bioinformatic methods were used to analyze gene expression, correlation, and patient survival according to the TCGA database. Thirty pairs of cancer tissues and distal cancer tissues from cervical cancer patients who received radical surgery were enrolled in the study. The expression of Mist1 was analyzed using Western blot. Furthermore, the potential associations among Mist1 expression, EMT biomarkers and various clinicopathological characteristics were investigated. All statistical tests employed in this study were two-sided, and P values <0.05 were deemed statistically significant.

Results

Overall survival data were obtained from TCGA-CESC dataset, containing 3 control samples and 305 tumor samples. The expression of Mist1 was significantly higher in primary tumor than in normal tissues (P<0.001). The samples were divided into a low Mist1 expression group (n=144) and a high Mist1 expression group (n=146) according to the median expression level. Kaplan–Meier survival analysis revealed that high expression of Mist1 was significantly correlated with poor overall survival (P=0.032). We further explored the relationships between Mist1 and EMT. Among the 30 primary cervical cancer specimens investigated, the difference in Mist1 expressed statuses between cervical cancer tissues and distal noncancerous cervical tissues was significant (P=0.001). And the epithelial cell marker E-cadherin was downregulated in Mist1 overexpressed cervical cancer cells; however, the mesenchymal marker N-Cadherin and Twist was upregulated.

Conclusion

Our study found that Mist1 seemed to play the role of oncogene in cervical squamous cell carcinoma and could be a potential biomarker.

Models to evaluate the barrier properties of mucus during drug diffusion

Mucus is widely disseminated in the nasal cavity, oral cavity, respiratory tract, eyes, gastrointestinal tract, and reproductive tract to prevent the invasion of pathogenic bacteria and toxins. The mucus layer through its continuous secretion can prevent the passage of macromolecular substances such as pathogenic bacteria and toxins, thereby reducing the occurrence of inflammation. Without a doubt, mucus also hinders oral absorption. The physiological and biochemical properties of intestinal mucus and the different types of mucus barrier models need to be predominated. To find ways to increase the bioavailability of drugs in the future, this article summarizes mucus composition, barrier properties, mucus models, and mucoadhesive/mucopenetrating particles to highlight the information they can afford. Collectively, the review seeks to provide a state-of-the-art roadmap for researchers who must contend with this critical barrier to drug delivery.

The cellular origins of cancer with particular reference to the gastrointestinal tract

Stem cells or their closely related committed progenitor cells are the likely founder cells of most neoplasms. In the continually renewing and hierarchically organized epithelia of the oesophagus, stomach and intestine, homeostatic stem cells are located at the beginning of the cell flux, in the basal layer of the oesophagus, the isthmic region of gastric oxyntic glands and at the bottom of gastric pyloric-antral glands and colonic crypts. The introduction of mutant oncogenes such as KrasG12D or loss of Tp53 or Apc to specific cell types expressing the likes of Lgr5 and Mist1 can be readily accomplished in genetically engineered mouse models to initiate tumorigenesis. Other origins of cancer are discussed including 'reserve' stem cells that may be activated by damage or through disruption of morphogen gradients along the crypt axis. In the liver and pancreas, with little cell turnover and no obvious stem cell markers, the importance of regenerative hyperplasia associated with chronic inflammation to tumour initiation is vividly apparent, though inflammatory conditions in the renewing populations are also permissive for tumour induction. In the liver, hepatocytes, biliary epithelial cells and hepatic progenitor cells are embryologically related, and all can give rise to hepatocellular carcinoma and cholangiocarcinoma. In the exocrine pancreas, both acinar and ductal cells can give rise to pancreatic ductal adenocarcinoma (PDAC), although the preceding preneoplastic states are quite different: acinar-ductal metaplasia gives rise to pancreatic intraepithelial neoplasia culminating in PDAC, while ducts give rise to PDAC via. mucinous cell metaplasia that may have a polyclonal origin.