Proteomic analysis of CD44(+) and CD44(−) gastric cancer cells

Abstract

CD44 is a cell surface protein and it is widely used as a cancer stem cell marker in various cancer types including gastric cancer. We conducted proteomic analysis in CD44(+) and CD44(-) gastric cancer cells to understand characteristics of CD44(+) and CD44(-) cells. In the present study, we sorted cells from the gastric cancer cell line MKN45 according to CD44 expression to separate out CD44(+) and CD44(-) cells. And we conducted RT-PCR to identify mRNA expression of cancer stem cell markers in CD44(+) and CD44(-) cells. Cancer stem cell markers showed upregulated expression in CD44(+) cells. Next, we performed two-dimensional electrophoresis analysis to determine the differential expression pattern of proteins in each group; control, CD44(+), and CD44(-) MKN45 cells. We found a total of 113 spots that varied in expression between CD44(+) and CD44(-) cells, and subjected 20 of those protein spots to MALDI-MS. We selected the three proteins (HSPA8; heat shock cognate 71 kDa protein isoform 1, ezrin, α-enolase) upregulated in CD44(+) cells than CD44(-) cells and one protein (prohibitin) showed increased expression in CD44(-) cells. We validated the protein expression levels of four selected proteins by Western blot. We suggest that our study could be a helpful background to study CD44(+) cancer stem-like cells and differences between CD44(+) and CD44(-) cells in gastric cancer.

miR‐26b‐5p helps in EpCAM+cancer stem cells maintenance via HSC71/HSPA8 and augments malignant features in HCC

“…For instance, global proteome profiling in pancreatic CSCs of xenograft mice tumours highlighted the involvement of signalling pathways related to apoptosis, cell proliferation, inflammation and metastasis in CSC regulation . Proteomic studies using cancer cell lines revealed the overexpression of Heat shock protein beta‐1 (HSPB1), Annexin A3 in breast CSCs and HSPA8, Ezrin, α‐enolase in gastric CSCs . However, there is paucity of data on differential proteomic analysis of primary hepatic CSCs.…”

“…15 Proteomic studies using cancer cell lines revealed the overexpression of Heat shock protein beta-1 (HSPB1), Annexin A3 in breast CSCs 16 and HSPA8, Ezrin, α-enolase in gastric CSCs. 17 However, there is paucity of data on differential proteomic analysis of primary hepatic CSCs.…”

Ring finger protein 43 associates with gastric cancer progression and attenuates the stemness of gastric cancer stem-like cells via the Wnt-β/catenin signaling pathway

“…All tumorspheres were maintained in culture for at least 14 days and passed three times to assure self-renewal ability. Stemness associated protein Sox-2 (SRY-box 2) [22] was also measured (Fig. 2a) to confirm sphere stem-like properties.…”

Cancer stem cells in human digestive tract malignancies

“…Besides introduced markers listed in Table 1 Apart from in vitro studies, analyzing clinical samples revealed that CD44 could be used in combination with clinicopathological information to improve the OSCC prognosis, since its overexpression, in tumor samples and peripheral blood of OSCC patients, was correlated to poor prognosis LGR5 [152,153] EpCAM [120] BMI1 [119,218] CD24 [122,125] OCT4 [118,119] SOX2 [118,119,[149][150][151] NANOG [118,119] Colon and rectum CD44 [166,[180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198]200] CD133 [161-165, 171-178, 186-188, 232] ABCG2 [75,158,159] ALDH1 [198,[222][223][224]…”

“…For example, it has been reported that CD44 + GC cells were highly proliferative, invasive, therapy resistant, and tumorigenic [115][116][117], and expressed SC markers OCT4, SOX2, and NANOG [118,119]. In other studies, GC cells, with the main in vitro and in vivo properties of CSCs, were isolated from GC cell lines and patient tissues and characterized as CD44 + EpCAM + [120], CD44 + CD54 + [121], CD44 + CD24 + [122], CD44 + CD26 + [123], CD44 + ABCG2 + [124], and CD44 + CD24 + ALDH1 + [125] cells.…”