Subcutaneous preconditioning increases invasion and metastatic dissemination in colorectal cancer models

Abstract

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.

The combined use of EFS, GPX2, and SPRR1A expression could distinguish favorable from poor clinical outcome among epithelial‐like head and neck carcinoma subtypes

“…Mice were sacrificed by cervical dislocation when tumors reached an approximate volume of 500 mm (measured using a caliper). Tumors were excised, embedded, and paraffinized as previously described . The study was approved by the Animal Ethics Committee at Hospital de la Santa Creu i Sant Pau (HSCSP) and conducted in accordance with the European Communities Council Directive of November 24, 1986 (86/609/EEC).…”

CKMT1 and NCOA1 expression as a predictor of clinical outcome in patients with advanced‐stage head and neck squamous cell carcinoma

“…Samples were incubated with monoclonal creatine kinase mitochondrial 1 (CKMT1; 1:500, anti‐CKMT1, NBP2‐13840; Novus Biologicals, UK) and nuclear receptor coactivator 1 (NCOA1; 1:500, anti‐KAT13A; Abcam, Cambridge, UK) antibodies for 1 hour. EnVision FLEX and FLEX + Visualization System was used for primary antibody detection, as previously described . We used colon tissue as a positive control for CKMT1 and NCOA1 expression in the IHC study.…”

Higher metastatic efficiency of KRas G12V than KRas G13D in a colorectal cancer model

“…Due to the low metastatic rate, we used subcutaneous preconditioning before orthotopic injection. This procedure was developed for CRC models and increases the metastatic rate without changing the pattern of metastases (11). This approach provides a sufficient rate of metastasis to compare metastatic development and regulation between KRas G12V‐ and KRas G13D‐derived models.…”