Interaction of tetraspan(in) TM4SF5 with CD44 promotes self‐renewal and circulating capacities of hepatocarcinoma cells

Abstract

Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Epithelial-mesenchymal transition (EMT) is related to self-renewal capacity and circulating tumor cell (CTC) characteristics for tumor metastasis. Although tumor metastasis is a life-threatening, complicated process that occurs through circulation of tumor cells, mechanistic aspects of self-renewal and circulating capacities have been largely unknown. Hepatic transmembrane 4 L six family member 5 (TM4SF5) promotes EMT for malignant growth and migration, so it was rationalized that TM4SF5, as a hepatocellular carcinoma (HCC) biomarker, might be important for metastatic potential. Here, self-renewal capacity by TM4SF5 was mechanistically explored using hepatocarcinoma cells with or without TM4SF5 expression, and we explored whether they became CTCs using mouse liverorthotopic model systems. We found that TM4SF5-dependent sphere growth correlated with CD242 , aldehyde dehydrogenase (ALDH) activity, as well as a physical association between CD44 and TM4SF5. Interaction between TM4SF5 and CD44 was through their extracellular domains with N-glycosylation modifications. TM4SF5/CD44 interaction activated proto-oncogene tyrosine-protein kinase Src (c-Src)/signal transducer and activator of transcription 3 (STAT3)/Twist-related protein 1 (Twist1)/B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi1) signaling for spheroid formation, whereas disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts using 2005,000 cells per injection, TM4SF5-positive tumors exhibited subpopulations with locally increased CD44 expressions, supporting for tumor cell differentiation. TM4SF5-positive, but not TM4SF5-or CD44-knocked-down, cells were identified circulating in blood 4-6 weeks after orthotopic liver injection using in vivo laser scanning endomicroscopy. Anti-TM4SF5 reagent blocked their metastasis to distal intestinal organs. Conclusion: TM4SF5 promotes self-renewal and CTC properties supported by TM4SF5 1 /CD442 markers during HCC metastasis. (HEPATOLOGY 2015;61:1978-1997 H epatocellular carcinoma (HCC) is the thirdmost common cause of mortality resulting from cancer.1 Although hepatic resection and liver transplantation represent first-line treatments for HCC, 2 the second-line treatment for HCC patients in advanced stages has shown limited efficacy.3 Moreover, metastatic recurrence renders this carcinoma resistant to any significant chemopreventive effects.

Anti-metastatic effect of the TM4SF5-specific peptide vaccine and humanized monoclonal antibody on colon cancer in a mouse lung metastasis model

“…TM4SF5-mediated focal adhesion kinase (FAK) activation seems to contribute to alteration of integrin-mediated cell adhesion and metastasis of HCC [11]. Recently, involvement of TM4SF5 and CD44 in the increase of circulating tumor cells has been suggested in HCC [12, 13]. Therefore, TM4SF5 has been proposed to be a reasonable target in management of HCC metastasis.…”

Bidirectional signaling between TM4SF5 and IGF1R promotes resistance to EGFR kinase inhibitors

“…Amplification of the c-MET gene, which encodes an RTK for hepatocyte growth factor (HGF), leading to cell scattering or EMT phenotypes, also leads to EGFR-TKI resistance [10,11]. Furthermore, TM4SF5 mediated-EMT phenotypes have even been correlated with resistance of HCC to paclitaxel [23].…”

Stem-like plasticity and heterogeneity of circulating tumor cells: current status and prospect challenges in liver cancer

“…After the binding of TM4SF5 to CD44, an activation of c-Src/STAT3/Twist1/Bmi1 signaling pathway promoted the release of metastatic stem-like CTCs in the blood of orthotopic mouse model. Interestingly, the knockdown of either TM4SF5 or CD44 or the disruption of their interaction abolished the presence of CTCs and metastatic properties [156]. …”