TY - JOUR
T1 - Co-expression of laminin β3 and γ2 chains and epigenetic inactivation of laminin α3 chain in gastric cancer
AU - Ii, Masanori
AU - Yamamoto, Hiroyuki
AU - Taniguchi, Hiroaki
AU - Adachi, Yasushi
AU - Nakazawa, Mayumi
AU - Ohashi, Hirokazu
AU - Tanuma, Tokuma
AU - Sukawa, Yasutaka
AU - Suzuki, Hiromu
AU - Sasaki, Shigeru
AU - Imai, Kohzoh
AU - Shinomura, Yasuhisa
PY - 2011/9
Y1 - 2011/9
N2 - Laminin-332 (LM-332, formerly termed laminin-5) is a heterotrimeric glycoprotein that regulates cell adhesion and migration. Molecular alterations of LM-332 are involved in cancer progression. The aim of this study was to clarify alterations of LM-332 in gastric carcinoma. The expression of LM-332 subunits in 10 gastric carcinoma cell lines was investigated by RT-PCR, Western blotting, and immunocytochemical/immunofluorescent analyses. The promoter methylation status of LM-332-encoding genes (LAMA3, LAMB3 and LAMC2) was analyzed by methylation-specific PCR (MSP). The relationship between cell migration and LM-332 expression was assessed by the scratch assay. The expression of LM-332 was analyzed immunohistochemically in 90 gastric cancer tissues. Co-expression of laminin β3 and γ2 chains was often observed in gastric carcinoma cell lines at mRNA and protein levels. In contrast, there was no expression of laminin α3 at either the mRNA or protein levels. Extra-cellular secretion of laminin β3 and γ2 chains was found in 2 of the 10 cell lines. The LAMA3 gene was transcriptionally silenced by methylation of the promoter CpG islands in all of the cell lines, while the LAMB3 and LAMC2 genes were silenced in several cell lines. Treatment with a demethylating agent, 5-aza-2′-deoxycytidine (5-aza-dC), restored expression of the LM-332-encoding genes. Methylation frequency of LAMA3 was higher than those of the LAMB2 and LAMC2 genes in gastric cancer tissues. Migration distances were significantly correlated with cytoplasmic laminin γ2 chain expression. Immunohistochemistry showed frequent co-expression of laminin β3 and γ2 chains in gastric carcinoma cells, which was significantly correlated with depth of invasion and advanced tumor stage. The results suggest that the laminin β3 and γ2 chains accumulate intracellularly and play a role in gastric cancer progression, while epigenetic silencing of the laminin α3 chain may lead to inability to synthesize the basement membrane and may affect cancer cell invasion. Cancer cell motility appears to be associated with the cytoplasmic laminin γ2 chain in vitro.
AB - Laminin-332 (LM-332, formerly termed laminin-5) is a heterotrimeric glycoprotein that regulates cell adhesion and migration. Molecular alterations of LM-332 are involved in cancer progression. The aim of this study was to clarify alterations of LM-332 in gastric carcinoma. The expression of LM-332 subunits in 10 gastric carcinoma cell lines was investigated by RT-PCR, Western blotting, and immunocytochemical/immunofluorescent analyses. The promoter methylation status of LM-332-encoding genes (LAMA3, LAMB3 and LAMC2) was analyzed by methylation-specific PCR (MSP). The relationship between cell migration and LM-332 expression was assessed by the scratch assay. The expression of LM-332 was analyzed immunohistochemically in 90 gastric cancer tissues. Co-expression of laminin β3 and γ2 chains was often observed in gastric carcinoma cell lines at mRNA and protein levels. In contrast, there was no expression of laminin α3 at either the mRNA or protein levels. Extra-cellular secretion of laminin β3 and γ2 chains was found in 2 of the 10 cell lines. The LAMA3 gene was transcriptionally silenced by methylation of the promoter CpG islands in all of the cell lines, while the LAMB3 and LAMC2 genes were silenced in several cell lines. Treatment with a demethylating agent, 5-aza-2′-deoxycytidine (5-aza-dC), restored expression of the LM-332-encoding genes. Methylation frequency of LAMA3 was higher than those of the LAMB2 and LAMC2 genes in gastric cancer tissues. Migration distances were significantly correlated with cytoplasmic laminin γ2 chain expression. Immunohistochemistry showed frequent co-expression of laminin β3 and γ2 chains in gastric carcinoma cells, which was significantly correlated with depth of invasion and advanced tumor stage. The results suggest that the laminin β3 and γ2 chains accumulate intracellularly and play a role in gastric cancer progression, while epigenetic silencing of the laminin α3 chain may lead to inability to synthesize the basement membrane and may affect cancer cell invasion. Cancer cell motility appears to be associated with the cytoplasmic laminin γ2 chain in vitro.
KW - Cell motility
KW - Gastric cancer
KW - Laminin γ2
KW - Laminin-332
KW - Methylation
UR - http://www.scopus.com/inward/record.url?scp=79959920814&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79959920814&partnerID=8YFLogxK
U2 - 10.3892/ijo.2011.1048
DO - 10.3892/ijo.2011.1048
M3 - Article
C2 - 21617852
AN - SCOPUS:79959920814
SN - 1019-6439
VL - 39
SP - 593
EP - 599
JO - International Journal of Oncology
JF - International Journal of Oncology
IS - 3
ER -
