Cytokeratin 18-associated Histone 3 Modulation in Hepatocellular Carcinoma: A Mini Review

Identification of T-cell exhaustion-related genes and prediction of their immunotherapeutic role in lung adenocarcinoma

Background: Lung adenocarcinoma ranks as the second most widespread form of cancer globally, accompanied by a significant mortality rate. Several studies have shown that T cell exhaustion is associated with immunotherapy of tumours. Consequently, it is essential to comprehend the possible impact of T cell exhaustion on the tumor microenvironment. The purpose of this research was to create a TEX-based model that would use single-cell RNA-seq (scRNA-seq) and bulk-RNA sequencing to explore new possibilities for assessing the prognosis and immunotherapeutic response of LUAD patients. Methods: RNA-seq data from LUAD patients was downloaded from the Cancer Genome Atlas (TCGA) database and the National Center for Biotechnology Information (GEO). 10X scRNA sequencing data, as reported by Bischoff P et al., was utilized for down-sampling clustering and subgroup identification using TSNE. TEX-associated genes were identified through gene set variance analysis (GSVA) and weighted gene correlation network analysis (WGCNA). We utilized LASSO-Cox analysis to establish predicted TEX features. External validation was conducted in GSE31210 and GSE30219 cohorts. Immunotherapeutic response was assessed in IMvigor210, GSE78220, GSE35640 and GSE100797 cohorts. Furthermore, we investigated differences in mutational profiles and immune microenvironment between various risk groups. We then screened TEXRS key regulatory genes using ROC diagnostic curves and KM survival curves. Finally, we verified the differential expression of key regulatory genes through RT-qPCR. Results: Nine TEX genes were identified as highly predictive of LUAD prognosis and strongly correlated with disease outcome. Univariate and multivariate analysis revealed that patients in the low-risk group had significantly better overall survival rates compared with those in the high-risk group, highlighting the model's ability to independently predict LUAD prognosis. Our analysis revealed significant variation in the biological function, mutational landscape, and immune cell infiltration within the tumor microenvironment of both high-risk and low-risk groups. Additionally, immunotherapy was found to have a significant impact on both groups, indicating strong predictive efficacy of the model. Conclusions: The TEX model showed good predictive performance and provided a new perspective for evaluating the efficacy of preimmunization, which provides a new strategy for the future treatment of lung adenocarcinoma.

A pancreatic adenocarcinoma mimicking hepatoid carcinoma of uncertain histogenesis: A case report and literature review

In rare cases, metastatic adenocarcinomas of different origin may exhibit the features of hepatoid carcinoma (HC), a rare malignant epithelial tumor, most commonly occurring in the ovaries and stomach, as well as in the pancreas and biliary ducts. A case of a 72-year-old female patient who developed a highly aggressive, poorly differentiated pancreatic ductal adenocarcinoma with peritoneal carcinomatosis, demonstrating hepatoid differentiation upon conventional hematoxylin and eosin staining is reported in the present study. The patient presented with severe abdominal pain, and the radiological investigations performed revealed ovarian and hepatic tumor masses and peritoneal lesions, which were surgically removed. The gross examination of the peritoneum and omentum revealed multiple solid, firm, grey-white nodules, diffusely infiltrating the adipose tissue. The microscopic examination revealed a malignant epithelial proliferation, composed of polygonal cells with abundant eosinophilic cytoplasm and irregular, pleomorphic nuclei. Certain cells presented with intracytoplasmic mucus inclusions, raising suspicion of a HC with an uncertain histogenesis. Immunohistochemical staining was performed, and the tumor cells were found to be positive for cytokeratin (CK)7, CK18 and mucin 5AC, whereas negative staining for CK20, caudal-type homeobox transcription factor 2, α-fetoprotein, paired box gene 8, GATA-binding protein 3 and Wilms tumor 1 were documented. Thus, the diagnosis of metastatic pancreatic adenocarcinoma was established. The main aim of the present study was to provide further knowledge concerning poorly differentiated metastatic adenocarcinoma resembling HC, emphasizing the histopathological and immunohistochemical features of these malignant lesions and raising awareness of the diagnostic difficulties that may arise, as well as the importance of the use immunohistochemistry in differentiating carcinomas of uncertain histogenesis.

Molecular Characterization of the Tumor Microenvironment in Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a highly aggressive disease associated with sickle hemoglobinopathies and universal loss of the tumor suppressor gene SMARCB1. RMC has a relatively low rate of incidence compared with other renal cell carcinomas (RCCs) that has hitherto made molecular profiling difficult. To probe this rare disease in detail we performed an in-depth characterization of the RMC tumor microenvironment using a combination of genomic, metabolic and single-cell RNA-sequencing experiments on tissue from a representative untreated RMC patient, complemented by retrospective analyses of archival tissue and existing published data. Our study of the tumor identifies a heterogenous population of malignant cell states originating from the thick ascending limb of the Loop of Henle within the renal medulla. Transformed RMC cells displayed the hallmarks of increased resistance to cell death by ferroptosis and proteotoxic stress driven by MYC-induced proliferative signals. Specifically, genomic characterization of RMC tumors provides substantiating evidence for the recently proposed dependence of SMARCB1-difficient cancers on proteostasis modulated by an intact CDKN2A-p53 pathway. We also provide evidence that increased cystine-mTORC-GPX4 signaling plays a role in protecting transformed RMC cells against ferroptosis. We further propose that RMC has an immune landscape comparable to that of untreated RCCs, including heterogenous expression of the immune ligand CD70 within a sub-population of tumor cells. The latter could provide an immune-modulatory role that serves as a viable candidate for therapeutic targeting.

Evaluation of the Cytotoxic Activity and Anti-Migratory Effect of Berberine–Phytantriol Liquid Crystalline Nanoparticle Formulation on Non-Small-Cell Lung Cancer In Vitro

Non-small-cell lung cancer (NSCLC) is the most common form of lung cancer, which is a leading cause of cancer-related deaths worldwide. Berberine is an isoquinoline alkaloid that is commercially available for use as a supplement for the treatment of diabetes and cardiovascular diseases. However, the therapeutic benefits of berberine are limited by its extremely low bioavailability and toxicity at higher doses. Increasing evidence suggests that the incorporation of drug compounds in liquid crystal nanoparticles provides a new platform for the safe, effective, stable, and controlled delivery of the drug molecules. This study aimed to formulate an optimized formulation of berberine–phytantriol-loaded liquid crystalline nanoparticles (BP-LCNs) and to investigate the in vitro anti-cancer activity in a human lung adenocarcinoma A549 cell line. The BP-LCN formulation possessing optimal characteristics that was used in this study had a favorable particle size and entrapment efficiency rate (75.31%) and a superior drug release profile. The potential mechanism of action of the formulation was determined by measuring the mRNA levels of the tumor-associated genes PTEN, P53, and KRT18 and the protein expression levels with a human oncology protein array. BP-LCNs decreased the proliferation, migration, and colony-forming activity of A549 cells in a dose-dependent manner by upregulating the mRNA expression of PTEN and P53 and downregulating the mRNA expression of KRT18. Similarly, BP-LCNs also decreased the expression of proteins related to cancer cell proliferation and migration. This study highlights the utility of phytantriol-based LCNs in incorporating drug molecules with low GI absorption and bioavailability to increase their pharmacological effectiveness and potency in NSCLC.

Novel Diagnostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is still a leading cause of cancer death worldwide. Less than half of cases are diagnosed when the cancer is locally advanced. CRC is a heterogenous disease associated with a number of genetic or somatic mutations. Diagnostic markers are used for risk stratification and early detection, which might prolong overall survival. Nowadays, the widespread use of semi-invasive endoscopic methods and feacal blood tests characterised by suboptimal accuracy of diagnostic results has led to the detection of cases at later stages. New molecular noninvasive tests based on the detection of CRC alterations seem to be more sensitive and specific then the current methods. Therefore, research aiming at identifying molecular markers, such as DNA, RNA and proteins, would improve survival rates and contribute to the development of personalized medicine. The identification of “ideal” diagnostic biomarkers, having high sensitivity and specificity, being safe, cheap and easy to measure, remains a challenge. The purpose of this review is to discuss recent advances in novel diagnostic biomarkers for tumor tissue, blood and stool samples in CRC patients.

Aspects of the Epigenetic Regulation of EMT Related to Cancer Metastasis

Epithelial to mesenchymal transition (EMT) occurs during the pathological process associated with tumor progression and is considered to influence and promote the metastatic cascade. Characterized by loss of cell adhesion and apex base polarity, EMT enhances cell motility and metastasis. The key markers of the epithelial to mesenchymal transition are proteins characteristic of the epithelial phenotype, e.g., E-cadherin, cytokeratins, occludin, or desmoplakin, the concentration and activity of which are reduced during this process. On the other hand, as a result of acquiring the characteristics of mesenchymal cells, an increased amount of N-cadherin, vimentin, fibronectin, or vitronectin is observed. Importantly, epithelial cells undergo partial EMT where some of the cells show both epithelial and mesenchymal characteristics. The significant influence of epigenetic regulatory mechanisms is observed in the gene expression involved in EMT. Among the epigenetic modifications accompanying incorrect genetic reprogramming in cancer are changes in the level of DNA methylation within the CpG islands and posttranslational covalent changes of histone proteins. All observed modifications, which are stable but reversible changes, affect the level of gene expression leading to the development and progression of the disease, and consequently affect the uncontrolled growth of the population of cancer cells.

Transitions in lineage specification and gene regulatory networks in hematopoietic stem/progenitor cells over human development

Human hematopoiesis is a dynamic process that starts in utero 18-21 days post-conception. Understanding the site- and stage-specific variation in hematopoiesis is important if we are to understand the origin of hematological disorders, many of which occur at specific points in the human lifespan. To unravel how the hematopoietic stem/progenitor cell (HSPC) compartment changes during human ontogeny and the underlying gene regulatory mechanisms, we compare 57,489 HSPCs from 5 different tissues spanning 4 developmental stages through the human lifetime. Single-cell transcriptomic analysis identifies significant site- and developmental stage-specific transitions in cellular architecture and gene regulatory networks. Hematopoietic stem cells show progression from cycling to quiescence and increased inflammatory signaling during ontogeny. We demonstrate the utility of this dataset for understanding aberrant hematopoiesis through comparison to two cancers that present at distinct time points in postnatal life-juvenile myelomonocytic leukemia, a childhood cancer, and myelofibrosis, which classically presents in older adults.

Development of metastasis-associated seven gene signature for predicting lung adenocarcinoma prognosis using single-cell RNA sequencing data

Metastasis is the primary cause of lung adenocarcinoma (LUAD)-related death. This study evaluated the metastasis-associated genes (MAGs) in single-cell RNA sequencing (scRNA-seq) data from LUAD tissues and developed a MAG signature to predict overall survival (OS) of LUAD patients. The LUAD scRNA-seq data was downloaded from the Gene Expression Omnibus (GEO) Database and MAGs were identified from LUAD scRNA-seq data. The LUAD transcriptomic and clinical data were obtained from The Cancer Genome Atlas (TCGA). Cox and LASSO regression analyses were performed to identify differentially expressed MAGs (DEMAGs) with prognostic value that were then used to construct a MAG signature and MAG-nomogram model. Finally, a functional enrichment analysis was performed via Gene Set Enrichment Analysis (GSEA). 414 MAGs and 22 prognostic DEMAGs were revealed in the study. Multivariate Cox proportional hazards regression analysis was utilized to construct a 7-MAG signature for predicting the OS of LUAD patients. Patients with high risk scores had a significantly worse OS than those with low risk scores in the training group (n = 236), and the 7-MAG signature was successfully confirmed in the testing group (n = 232) and the entire TCGA-LUAD cohort (n = 468). Furthermore, univariate and multivariate Cox regression suggested that the 7-MAG signature was an independent prognostic indicator. Additionally, based on the 7-MAG signature, a nomogram was established that could more intuitively help to predict the OS of LUAD patients. The GSEA revealed the underlying molecular mechanisms of the 7-MAG signature in LUAD metastasis. In conclusion, a 7-MAG signature was developed based on LUAD scRNA-seq data that could effectively predict LUAD patient prognosis and provide novel insights for therapeutic targets and the potential molecular mechanism of metastatic LUAD.

Keratin 18 induces proliferation, migration, and invasion in gastric cancer via the MAPK signalling pathway

PURPOSE

Keratin 18 (KRT18) is a cytoskeleton protein that plays a key role in multiple cancers. The present study aims to further investigate the roles of KRT18 in gastric cancer (GC) tissues and cells.

METHODS

The KRT18 protein expression levels of GC tissues and cells were detected using immunohistochemistry and western blot. The relationship between KRT18 expression levels and the prognosis of GC patients was further analyzed. To explore this relationship, small interfering RNA (siRNA) was used to inhibit the endogenous expression of KRT18 in GC cells. Furthermore, the effects of KRT18 on the proliferation, invasion, migration, and apoptosis of GC cells were analyzed in vitro. In addition, the role of KRT18 in GC-specific processes was investigated.

RESULTS

Keratin 18 expression was shown to be up-regulated in GC tissues and associated with poor prognosis. Following KRT18 silencing with siRNA, the proliferation, invasion, and migration ability of GC cells were significantly inhibited, while the apoptotic process was promoted. Furthermore, the activation of the MAPK signalling pathway was identified as the potential mechanism through which KRT18 influenced GC processes.

CONCLUSIONS

Keratin 18 plays a cancer-promoting role and might be a potential therapeutic target in the treatment of GC.

KRT18 is correlated with the malignant status and acts as an oncogene in colorectal cancer

Keratin 18 (KRT18) has been suggested to be overexpressed in most types of human tumor, but the expression pattern of KRT18 in colorectal cancer (CRC) remained unknown. In our research, KRT18 protein expression was markedly increased in CRC cancer tissues and cell lines compared with adjacent normal colorectal tissues and normal colonic epithelial cell line, respectively. Meanwhile, we observed high KRT18 expression was associated with advanced clinical stage, deep tumor invasion, lymph node metastasis, distant metastasis, poor differentiation and unfavorable prognosis in CRC patients. Multivariate Cox regression analysis showed high expression of KRT18 was an unfavorable independent predictor for overall survival in CRC patients. The in vitro studies indicated down-regulation of KRT18 expression depressed CRC cell viability, migration and invasion. In conclusion, KRT18 serves as an oncogenic role in CRC progression and may be a therapeutic target for promoting CRC patients' prognosis.

Cytokeratin 18 regulates the transcription and alternative splicing of apoptotic‑related genes and pathways in HeLa cells

Cytokeratin 18 (CK18), one of the major components of intermediate filaments (IF) in simple epithelial cells, undergoes caspase-mediated cleavage upon epithelial cell necrosis and apoptosis. CK18 has been used as a biomarker of several cancers and has been reported to be dysregulated in cervical cancers. The effects of dysregulated expression of CK18 at a molecular level are, however, unclear. In the present study, the function of CK18 in HeLa cells, a cell line derived from a cervical cancer cells, was investigated using shRNA knockdown. Reduced levels of CK18 led to a significant decrease in cell apoptosis, compared with control cells. Notably, RNA-seq analysis of the transcriptomes of HeLa cells, with or without CK18 knockdown, revealed that genes in the NF-κB pathway, and certain apoptosis pathways, were under global transcriptional and alternative splicing regulation. Quantitative RT-PCR confirmed the CK18-regulated transcription of apoptotic genes FAS and FADD, as well as immune genes CXCL2 and CD79B, in addition to alternative splicing of FAS and CTNNB1. Western blot analysis further revealed that CK18 knockdown led to reduced expression of CASP8. In conclusion, the present study indicated that CK18 played a role in apoptosis, which may be mediated via a feed-back regulation loop and may involve regulation of transcription and alternative splicing of a number of genes in apoptotic pathways.

Epigenetic alterations caused by aflatoxin b1: a public health risk in the induction of hepatocellular carcinoma

Aflatoxin B1 (AFB1) is currently the most commonly studied mycotoxin due to its great toxicity, its distribution in a wide variety of foods such as grains and cereals and its involvement in the development of + (hepatocellular carcinoma; HCC). HCC is one of the main types of liver cancer, and has become a serious public health problem, due to its high incidence mainly in Southeast Asia and Africa. Studies show that AFB1 acts in synergy with other risk factors such as hepatitis B and C virus leading to the development of HCC through genetic and epigenetic modifications. The genetic modifications begin in the liver through the biomorphic AFB1, the AFB1-exo-8.9-Epoxy active, which interacts with DNA to form adducts of AFB1-DNA. These adducts induce mutation in codon 249, mediated by a transversion of G-T in the p53 tumor suppressor gene, causing HCC. Thus, this review provides an overview of the evidence for AFB1-induced epigenetic alterations and the potential mechanisms involved in the development of HCC, focusing on a critical analysis of the importance of severe legislation in the detection of aflatoxins.