Subcutaneous preconditioning increases invasion and metastatic dissemination in mouse colorectal cancer models.
Mouse colorectal cancer (CRC) models generated by orthotopic microinjection of human CRC cell lines reproduce the pattern of lymphatic, haematological and transcoelomic spread but generate low metastatic efficiency. Our aim was to develop a new strategy that could increase the metastatic efficiency of these models. We used subcutaneous implantation of the human CRC cell lines HCT116 or SW48 prior to their orthotopic microinjection in the cecum of nude mice (SC+ORT). This subcutaneous preconditioning significantly enhanced metastatic dissemination. In the HCT116 model it increased the number and size of metastatic foci in lymph nodes, lung, liver and peritoneum, whereas, in the SW48 model, it induced a shift from non-metastatic to metastatic. In both models the number of apoptotic bodies in the primary tumour in the SC+ORT group was significantly reduced compared with that in the direct orthotopic injection (ORT) group. Moreover, in HCT116 tumours the number of keratin-positive tumour buddings and single epithelial cells increased at the invasion front in SC+ORT mice. In the SW48 tumour model, we observed a trend towards a higher number of tumour buds and single cells in the SC+ORT group but this did not reach statistical significance. At a molecular level, the enhanced metastatic efficiency observed in the HCT116 SC+ORT model was associated with an increase in AKT activation, VEGF-A overexpression and downregulation of β1 integrin in primary tumour tissue, whereas, in SW48 SC+ORT mice, the level of expression of these proteins remained unchanged. In summary, subcutaneous preconditioning increased the metastatic dissemination of both orthotopic CRC models by increasing tumour cell survival and invasion at the tumour invasion front. This approach could be useful to simultaneously study the mechanisms of metastases and to evaluate anti-metastatic drugs against CRC.
Oncogenesis and Antitumour Drug Group, Biomedical Research Institute Sant Pau (IIB-SantPau), Hospital de la Santa Creu i Sant Pau, C/Sant Antoni Maria Claret, 167, 08025 Barcelona, Spain.
Patricia
P
Alamo
Alberto
A
Gallardo
Miguel A
MA
Pavón
Isolda
I
Casanova
Manuel
M
Trias
Maria A
MA
Mangues
Esther
E
Vázquez
Antonio
A
Villaverde
Ramon
R
Mangues
Maria V
MV
Céspedes
D000818:Animals; D017209:Apoptosis; D002449:Cell Aggregation; D002452:Cell Count; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D051379:Mice; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D040521:Subcutaneous Tissue / Q000473:pathology*; D023041:Xenograft Model Antitumor Assays
D009363:Neoplasm Proteins
Collective invasion; Colorectal cancer model; Metastasis; Orthotopic injection; Single tumour cell; Subcutaneous preconditioning