[Claudin-3 expression in gastric cancer]

HKDC1 Silencing Inhibits Proliferation and Glycolysis of Gastric Cancer Cells

Gastric cancer (GC) is the third most lethal and fifth most common cancer in the world. In a variety of cancers, the hexokinase domain component 1 (HKDC1) is carcinogenic. This study was to investigate into how HKDC1 contributes to the development and progression of GC. Three different datasets (GSE103236, GSE13861, and GSE55696) were extracted from the Gene Expression Omnibus (GEO) database and then analyzed using the sva package. The R software was used to identify 411 differentially expressed genes (DEGs) in the pooled dataset. We discovered 326 glycolysis-related genes (glyGenes) in the cancer genome atlas-stomach adenocarcinoma (TCGA-STAD) cohort using gene set enrichment analysis set (GSEA). HKDC1 is one of the most prevalent glyGenes in GC tumor tissues and cells, as seen in the Venn diagram. According to the results of the Cell Count Kit-8 assay, the proliferation of AGS and MKN-45 cells decreased when HKDC1 was knocked down. Lack of HKDC1 in cells enhanced oxygen consumption and decreased glycolytic protein expression while suppressing glucose absorption, lactate production, ATP level, and extracellular acidification ratio. As an oncogene in gastric cancer development, HKDC1 influences cell proliferation and glycolysis.

Application of C-Terminal Clostridium Perfringens Enterotoxin in Treatment of Brain Metastasis from Breast Cancer

Claudin-4 is part of the Claudin family of transmembrane tight junction (TJ) proteins found in almost all tissues and, together with adherens junctions and desmosomes, forms epithelial and endothelial junctional complexes. Although the distribution of Claudin-4 occurs in many cell types, the level of expression is cell-specific. Claudin proteins regulate cell proliferation and differentiation by binding cell-signaling ligands, and its expression is upregulated in several cancers. As a result, alterations in Claudin expression patterns or distribution are vital in the pathology of cancer. Profiling the genetic expression of Claudin-4 showed that Claudin-4 is also a receptor for the clostridium perfringens enterotoxin (CPE) and that Claudin-4 has a high sequence similarity with CPE's high-affinity receptor. CPE is cytolytic due to its ability to form pores in cellular membranes, and CPE treatment in breast cancer cells have shown promising results due to the high expression of Claudin-4. The C-terminal fragment of CPE (c-CPE) provides a less toxic alternative for drug delivery into breast cancer cells, particularly metastatic tumors in the brain, especially as Claudin-4 expression in the central nervous system (CNS) is low. Therefore, c-CPE provides a unique avenue for the treatment of breast-brain metastatic tumors.

Claudin 6: Therapeutic prospects for tumours, and mechanisms of expression and regulation (Review)

Tight junctions (TJs) are an important component of cell connectivity; they maintain cell polarity, permeability and adhesion, and participate in the regulation of cell proliferation and differentiation. The claudin (CLDN) family is integral to TJs, and CLDN6 is an important member of this family. Abnormal expression of CLDN6 can destroy the integrity of TJs through various mechanisms and can serve multiple roles in the occurrence and development of tumours. CLDN6 is widely expressed in various tumours but rarely expressed in healthy adult tissues. The aim of this review is to critically examine the recent literature on CLDN6, including its structure, expression in different tumours, regulatory mechanisms and therapeutic prospects. Although some conclusions are controversial, in certain tumours, such as liver, ovarian, endometrial and oesophageal cancer, and atypical teratoid/rhabdoid tumours, research consistently shows that CLDN6 is expressed in tumour tissues but is not expressed or is expressed at low levels in surrounding tissues. In these tumours, CLDN6 has potential as a carcinoembryonic antigen and a therapeutic target.