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Induction of tumor initiation is dependent on CD44s in c-Met⁺ hepatocellular carcinoma.

Dang H, Steinway SN, Ding W, Rountree CB - BMC Cancer (2015)

Bottom Line: The knockdown of c-Met in MHCC97-H cells decreased CD44s, reduced TISC characteristics and decreased tumorsphere formation.The down-regulation of CD44s leads to a significant loss of a TISC and mesenchymal phenotype.Finally, the down-regulation of CD44s in MHCC97-H cells decreased tumor initiation in vivo compared with the scrambled control.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics and Pharmacology, The Pennsylvania State University, College of Medicine, Penn State Children's Hospital, Hershey, PA, USA. danghi@mail.nih.gov.

ABSTRACT

Background: Hepatocellular carcinoma (HCC) patients with active hepatocyte growth factor (HGF)/c-Met signaling have a significantly worse prognosis. c-Met, a high affinity receptor for HGF, plays a critical role in cancer growth, invasion and metastasis. c-Met and CD44 have been utilized as cell surface markers to identify mesenchymal tumor-initiating stem-like cells (TISC) in several cancers including HCC. In this work, we examine the complex relationship between c-Met and CD44s (standard form), and investigate the specific role of CD44s as a tumor initiator and stemness marker in HCC.

Methods: Gene and protein expression assays were utilized to investigate the relationship between CD44s and c-Met in HCC cell lines. Tumor-sphere assays and in vivo tumor assays were performed to investigate the role of CD44+ cells as TISCs. Student's t-test or one-way ANOVA with Tukeys post-hoc test was performed to test for differences amongst groups with a p < .05 as significant.

Results: In an immunohistochemical and immunoblot analysis of human HCC samples, we observed that more than 39% of human HCC samples express c-Met and CD44. To study the relationship between c-Met and CD44, we used MHCC97-H cells, which are CD44(+)/c-Met(+). The knockdown of c-Met in MHCC97-H cells decreased CD44s, reduced TISC characteristics and decreased tumorsphere formation. Furthermore, we demonstrate that the inhibition of PI3K/AKT signaling decreased CD44s expression and subsequently decreased tumorsphere formation. The down-regulation of CD44s leads to a significant loss of a TISC and mesenchymal phenotype. Finally, the down-regulation of CD44s in MHCC97-H cells decreased tumor initiation in vivo compared with the scrambled control.

Conclusions: In summary, our data suggest that CD44s is modulated by the c-Met-PI3K-AKT signaling cascade to support a mesenchymal and TISC phenotype in HCC cells. Moreover, c-Met could be a potential therapeutic drug for targeting HCC cells with TISC and mesenchymal phenotypes.

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CD44s correlates with c-Met expression in human HCC samples. (A) Representative western blot in which 7 out of 33 human clinical HCC samples demonstrating c-Met, CD44v6 and CD44s co-expression. See Additional file 1: Figure S1 for all 33 samples. (B) Representative images of CD44 and c-Met immunohistochemistry performed on 68 human HCC tissues using anti-CD44 and c-Met antibodies (400X).
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Fig1: CD44s correlates with c-Met expression in human HCC samples. (A) Representative western blot in which 7 out of 33 human clinical HCC samples demonstrating c-Met, CD44v6 and CD44s co-expression. See Additional file 1: Figure S1 for all 33 samples. (B) Representative images of CD44 and c-Met immunohistochemistry performed on 68 human HCC tissues using anti-CD44 and c-Met antibodies (400X).

Mentions: To investigate the correlation between c-Met and CD44, we performed immunohistochemistry staining on 68 HCC tumors (Figure 1B) and immnoblotted 33 HCC tumors (Figure 1A). Immunohistochemical analysis demonstrated that 39% (27/68) of the human HCC samples are c-Met+ CD44+ (Figure 1B). Immunoblot analysis of an additional 33 HCC samples demonstrated a similar correlation between c-Met and CD44s in 45% (15/33) of the samples (Figure 1A and Additional file 1: Figure S1).Figure 1


Induction of tumor initiation is dependent on CD44s in c-Met⁺ hepatocellular carcinoma.

Dang H, Steinway SN, Ding W, Rountree CB - BMC Cancer (2015)

CD44s correlates with c-Met expression in human HCC samples. (A) Representative western blot in which 7 out of 33 human clinical HCC samples demonstrating c-Met, CD44v6 and CD44s co-expression. See Additional file 1: Figure S1 for all 33 samples. (B) Representative images of CD44 and c-Met immunohistochemistry performed on 68 human HCC tissues using anti-CD44 and c-Met antibodies (400X).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4380258&req=5

Fig1: CD44s correlates with c-Met expression in human HCC samples. (A) Representative western blot in which 7 out of 33 human clinical HCC samples demonstrating c-Met, CD44v6 and CD44s co-expression. See Additional file 1: Figure S1 for all 33 samples. (B) Representative images of CD44 and c-Met immunohistochemistry performed on 68 human HCC tissues using anti-CD44 and c-Met antibodies (400X).
Mentions: To investigate the correlation between c-Met and CD44, we performed immunohistochemistry staining on 68 HCC tumors (Figure 1B) and immnoblotted 33 HCC tumors (Figure 1A). Immunohistochemical analysis demonstrated that 39% (27/68) of the human HCC samples are c-Met+ CD44+ (Figure 1B). Immunoblot analysis of an additional 33 HCC samples demonstrated a similar correlation between c-Met and CD44s in 45% (15/33) of the samples (Figure 1A and Additional file 1: Figure S1).Figure 1

Bottom Line: The knockdown of c-Met in MHCC97-H cells decreased CD44s, reduced TISC characteristics and decreased tumorsphere formation.The down-regulation of CD44s leads to a significant loss of a TISC and mesenchymal phenotype.Finally, the down-regulation of CD44s in MHCC97-H cells decreased tumor initiation in vivo compared with the scrambled control.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics and Pharmacology, The Pennsylvania State University, College of Medicine, Penn State Children's Hospital, Hershey, PA, USA. danghi@mail.nih.gov.

ABSTRACT

Background: Hepatocellular carcinoma (HCC) patients with active hepatocyte growth factor (HGF)/c-Met signaling have a significantly worse prognosis. c-Met, a high affinity receptor for HGF, plays a critical role in cancer growth, invasion and metastasis. c-Met and CD44 have been utilized as cell surface markers to identify mesenchymal tumor-initiating stem-like cells (TISC) in several cancers including HCC. In this work, we examine the complex relationship between c-Met and CD44s (standard form), and investigate the specific role of CD44s as a tumor initiator and stemness marker in HCC.

Methods: Gene and protein expression assays were utilized to investigate the relationship between CD44s and c-Met in HCC cell lines. Tumor-sphere assays and in vivo tumor assays were performed to investigate the role of CD44+ cells as TISCs. Student's t-test or one-way ANOVA with Tukeys post-hoc test was performed to test for differences amongst groups with a p < .05 as significant.

Results: In an immunohistochemical and immunoblot analysis of human HCC samples, we observed that more than 39% of human HCC samples express c-Met and CD44. To study the relationship between c-Met and CD44, we used MHCC97-H cells, which are CD44(+)/c-Met(+). The knockdown of c-Met in MHCC97-H cells decreased CD44s, reduced TISC characteristics and decreased tumorsphere formation. Furthermore, we demonstrate that the inhibition of PI3K/AKT signaling decreased CD44s expression and subsequently decreased tumorsphere formation. The down-regulation of CD44s leads to a significant loss of a TISC and mesenchymal phenotype. Finally, the down-regulation of CD44s in MHCC97-H cells decreased tumor initiation in vivo compared with the scrambled control.

Conclusions: In summary, our data suggest that CD44s is modulated by the c-Met-PI3K-AKT signaling cascade to support a mesenchymal and TISC phenotype in HCC cells. Moreover, c-Met could be a potential therapeutic drug for targeting HCC cells with TISC and mesenchymal phenotypes.

Show MeSH
Related in: MedlinePlus