Induction of KIFC1 expression in gastric cancer spheroids

Abstract

Gastric cancer (GC) is one of the most common human cancers. Spheroid colony formation is an effective model for characterization of cancer stem cells. However, gene expression profiles of spheroid colonies obtained from GC cells have not been examined. We performed microarray analyses by Human Genome U133 Plus 2.0 Array in spheroid body-forming and parental cells from MKN-45 and MKN-74 GC cell lines. Kinesin family member C1 (KIFC1) was expressed >2-fold higher in spheroid body-forming cells than in parental cells in both GC lines. Both the number and size of spheres from MKN-45 cells were significantly reduced upon KIFC1 siRNA-transfection compared with negative control siRNA-transfection. Immunohistochemical analysis of 114 GC tissue samples revealed that 42 (37%) of GC cases were positive for KIFC1 expression. GC cases positive for KIFC1 were found more frequently in stage III/IV cases than in stage I/II cases. GC cases positive for KIFC1 were found more frequently in intestinal type GC cases than in diffuse type GC cases. Furthermore, KIFC1-positive GC cases showed high Ki-67 labeling index. Kaplan-Meier analysis demonstrated that KIFC1 expression was not associated with survival. We found positive expression of KIFC1 in CD44‑positive GC and aldehyde dehydrogenase 1 (ALDH1)-positive GC cells. Our results showed that KIFC1 is overexpressed in GC. Since knockdown of KIFC1 inhibited sphere formation, KIFC1 likely plays an important role in cancer stem cells.

Overexpression of the Transmembrane Protein IQGAP3 Is Associated with Poor Survival of Patients with Gastric Cancer

“…Previously, we identified several genes that were upregulated in spheroid body-forming GC cells compared with parental cells [6]. Among these, we reported the upregulation of KIFC1 and KIF11 proteins in GC cases [6, 7], and showed that both the number and size of spheres from GC cell lines were significantly reduced by knockdown of KIFC1 and KIF11 .…”

“…In the present study, we focused on the IQ motif containing the GTPase-activating protein 3 gene (IQGAP3) , because we previously observed it to be upregulated in spheroid body-forming cells compared with parental cells [6]. Moreover, because IQGAP3 is a transmembrane protein, it has the potential to be a therapeutic target [8].…”

“…Previously, we reported on the upregulation of genes in spheroid body-forming GC cell lines compared with parental cells [6]. We showed that KIFC1 and KIF11 protein expression is upregulated in 37 and 72%, respectively, of GC cases, and that both the number and size of spheres from GC cell lines are significantly reduced in KIFC1 and KIF11 small interfering (si)RNA-transfected cells compared with negative control siRNA-transfected cells [6, 7]. However, the expression of many genes remains unconfirmed, and their role in GC is unclear.…”

KIF11 Is Required for Spheroid Formation by Oesophageal and Colorectal Cancer Cells

“…We previously demonstrated that KIF11 and KIFC1 genes are more highly expressed in spheroid-forming cells than in parental GC cells (5). We also reported that KIF11 likely plays an important role in gastric CSCs (6).…”

“…One useful method for characterizing CSCs is spheroid colony formation. We previously showed that KIF11 and kinesin family C1 (KIFC1) genes are more highly expressed, by more than two-fold, in spheroid-forming cells than in the parental cells of GC cell lines (5). We also showed that KIF11 protein expression is upregulated in GC tissue samples, and that both the number and size of spheres produced by GC cells are significantly reduced by inhibition of KIF11 (6).…”