Establishment of Primary Colorectal and Paired Liver Metastatic Cancer Cell Lines from the Same Patients and Analysis of Differential Expressed Genes

Abstract

Introduction: Liver is the predominant metastatic site in colorectal cancer and it is important to understand the molecular alteration of liver metastasis. The paired primary/liver metastatic tumor cell lines from the same patient may provides better understanding of molecular biology for tumor homogeneity. Thus, we established the same patient-derived paired cancer cell lines from primary tumor and liver metastasis and further investigated the molecular alterations in liver metastatic tumors, compared to primary colorectal cancer by using RNA microarray. Methods: The primary colorectal cancer cell lines and the paired liver metastatic cell lines were successfully established

SNU-2337A/B, SNU-2536B/C, and SNU-2600A/B. We investigated distinct genes which were consistently up-regulated or down-regulated in three paired cell lines by using RNA microarray and selected genes to yield similar results in the paired lymph node metastatic cell lines (SW480/620, SNU-769B/A) from the same patients. We further evaluated these genes by RT-PCR (reverse transcription-polymerase chain reaction) and western blot analysis. Results: Twenty-three genes were up-regulated and thirty-seven were down-regulated in 3 liver metastatic cell lines simultaneously. Based on confirmation of paired lymph node metastatic cell lines, L-plastin was conserved increased expression and MUC12 and phospholipase C ε-1 (PLCE1) were conserved decreased expression. The results of RT-PCR and western blot supported the expression patterns of these genes. Conclusions: These newly established paired cancer cell lines from the same patients may provide further information for complex process of liver metastasis. Additionally, we found that L-plastin was also up-regulated in the liver metatastic cell lines, besides the lymph node metastatic cell lines.