Molecular Network Pathway Of ERBB In Diffuse-Type Gastric Cancer, Mesenchymal Stem Cells And Epithelial-Mesenchymal Transition

Abstract

Epithelial-mesenchymal transition (EMT) is related to malignancy and metastasis in cancer. The molecular networks including tyrosine kinases are altered in gastric cancer (GC). This study aims to reveal the role of ERBBs (erb-b2 receptor tyrosine kinases) in EMT, and generate the molecular network pathway of ERBBs in diffusetype GC and mesenchymal stem cells (MSCs). The expression of ERBB genes was analyzed in MSCs and diffuse-type GC which has mesenchymal characteristics compared to intestinal-type GC. The signaling and molecular network of ERBB was analyzed using several databases, including cBioPortal for Cancer Genomics, Kyoto Encyclopedia of Genes and Genomes (KEGG), BioGRID and VaProS. ERBB2 and ERBB3 gene expression were up-regulated in diffuse-type GC compared to MSCs. The ERBB3 molecular network includes epidermal growth factor receptor (EGFR), cadherin 1 (CDH1), catenin beta 1 (CTNNB1) and EPH receptor A5 (EPHA5). These results demonstrate the importance of the ERBB network in cancer signaling, and revealed a ERBB3 network pathway model in diffuse-type GC and MSCs, and EMT.Keywords: Epithelial-mesenchymal transition; Gastric cancer; Mesenchymal stem cell; ERBB; Stem cell cancer (GC) [7]. Mutations in extracellular domains of ERBB2 are suggested to be oncogenic in lung cancer [8].Since previous reports have demonstrated that the ERBB members are involved in cancer and stem cell networks, it is important to elucidate the role of ERBBs in EMT and cancer resistance. To further reveal the mechanism of EMT in cancer and stem cells, we investigated the expression of ERBB genes in mesenchymal stem cells (MSCs) and diffuse-type GC, and generated ERBB network pathway model. Materials and Methods Gene expression analysis of MSCs and GCGene expression in MSCs (6 early-and 6 late-stage cultures, n=12) and diffuse-type GC (n=5) was analyzed with GeneChip® Human Genome U133 Plus 2.0 microarray (Affymetrix, Santa Clara, California, USA), as previously described [1,9,10]. Briefly, total purified cellular RNA was biotinylated and hybridized to the microarray. Cell cultureHuman MSCs from bone marrow (Lonza, Walkersville, MD, USA) were cultured in MSC growth medium (MSCGM; Lonza #PT-3001; MSC basal medium supplemented with mesenchymal cell growth supplement, L-glutamine and penicillin/streptomycin) at 37°C in a CO 2 (5%) incubator. Cells were passaged according to the manufacturer's protocol, however a slight modification was made to use trypsin-EDTA solution (Lonza #CC-3232). Lot numbers of the human MSC batches were as follows: #4F1127, #4F0312, #5F0138, #4F1560, #4F0591 and #4F0760. Informed consent was obtained for Poietics human MSC systems (Lonza) [10]. Passage numbers of MSC cultures were #4 and #22 for #4F1127, #4 and #28 for #4F0312, #4 and #24 for #5F0138, #5 and #28 for #4F1560, #4 and #28 for #4F0591, and #4 and #28 for #4F0760. Diffuse-Type GC tissuesDiffuse-type GC tissues were originally provided by the National Cancer Center Hospital after obtaining written informed consent from each patient and ...