title: Host and tumor derived MMP13 regulate extravasation and establishment of colorectal metastases in the liver.
abstract: BACKGROUND
  Non alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases in the United States and worldwide. Our studies have previously shown an increase in metastatic burden in steatotic vs. normal livers using a mouse model of diet induced steatosis. In the present study we aim to identify and evaluate the molecular factors responsible for this increase in tumor burden.
  
  
  METHODS
  We assessed changes in expression of a panel of matrix metalloproteinases (MMPs) using qRT-PCR between normal and steatotic livers and validated them with western blot analysis of protein levels. To evaluate the role of MMP13 on tumor development, we utilized a splenic injection model of liver metastasis in Wildtype and Mmp13 deficient mice, using either parental or stable Mmp13 knockdown cell lines. Further, to evaluate changes in the ability of tumor cells to extravasate we utilized whole organ confocal microscopy to identify individual tumor cells relative to the vasculature. MTT, migration and invasion assays were performed to evaluate the role of tumor derived MMP13 on hallmarks of cancer in vitro.
  
  
  RESULTS
  We found that MMP13 was significantly upregulated in the steatotic liver both in mice as well as human patients with NAFLD. We showed a decrease in metastatic tumor burden in Mmp13-/- mice compared to wildtype mice, explained in part by a reduction in the number of tumor cells extravasating from the hepatic vasculature in the Mmp13-/- mice compared to wildtype mice. Additionally, loss of tumor derived MMP13 through stable knockdown in tumor cell lines lead to decreased migratory and invasive properties in vitro and metastatic burden in vivo.
  
  
  CONCLUSIONS
  This study demonstrates that stromal as well as tumor derived MMP13 contribute to tumor cell extravasation and establishment of metastases in the liver microenvironment.
authors.affiliation: Department of Cancer Biology, Vanderbilt University, 2220 Pierce Ave S, Nashville, TN, 37232, USA. alisha.m.mendonsa@vanderbilt.edu.
authors.forename: Alisha M
authors.initials: AM
authors.lastname: Mendonsa
authors.affiliation: Department of Cancer Biology, Vanderbilt University, 2220 Pierce Ave S, Nashville, TN, 37232, USA. michael.n.vansaun@vanderbilt.edu.|Department of Surgery, Vanderbilt University, 801 Oxford House, 1313 21st Ave. S, Nashville, TN, 37212, USA. michael.n.vansaun@vanderbilt.edu.
authors.forename: Michael N
authors.initials: MN
authors.lastname: VanSaun
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University, 702 Light Hall 21st Avenue South, Nashville, TN, 37232, USA. alessandro.ustione@vanderbilt.edu.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ustione
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University, 702 Light Hall 21st Avenue South, Nashville, TN, 37232, USA. dave.piston@vanderbilt.edu.
authors.forename: David W
authors.initials: DW
authors.lastname: Piston
authors.affiliation: Department of Cancer Biology, Vanderbilt University, 2220 Pierce Ave S, Nashville, TN, 37232, USA. barbara.fingleton@vanderbilt.edu.
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Fingleton
authors.affiliation: Department of Cancer Biology, Vanderbilt University, 2220 Pierce Ave S, Nashville, TN, 37232, USA. lee.gorden@vanderbilt.edu.|Department of Surgery, Vanderbilt University, 801 Oxford House, 1313 21st Ave. S, Nashville, TN, 37212, USA. lee.gorden@vanderbilt.edu.
authors.forename: David Lee
authors.initials: DL
authors.lastname: Gorden
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary*; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009361:Neoplasm Invasiveness; D017154:Stromal Cells / Q000378:metabolism
chemical_list: D053509:Matrix Metalloproteinase 13