Biomarkers of NAFLD progression: a lipidomics approach to an epidemic.

The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. Recognition and timely diagnosis of these different stages, particularly NASH, is important for both potential reversibility and limitation of complications. Liver biopsy remains the clinical standard for definitive diagnosis. Diagnostic tools minimizing the need for invasive procedures or that add information to histologic data are important in novel management strategies for the growing epidemic of NAFLD. We describe an "omics" approach to detecting a reproducible signature of lipid metabolites, aqueous intracellular metabolites, SNPs, and mRNA transcripts in a double-blinded study of patients with different stages of NAFLD that involves profiling liver biopsies, plasma, and urine samples. Using linear discriminant analysis, a panel of 20 plasma metabolites that includes glycerophospholipids, sphingolipids, sterols, and various aqueous small molecular weight components involved in cellular metabolic pathways, can be used to differentiate between NASH and steatosis. This identification of differential biomolecular signatures has the potential to improve clinical diagnosis and facilitate therapeutic intervention of NAFLD.

Increased metastases are associated with inflammation and matrix metalloproteinase-9 activity at incision sites in a murine model of peritoneal dissemination of colorectal cancer.

BACKGROUND: Pro-inflammatory processes associated with the early postoperative state are known to contribute to peritoneal metastases in patients with advanced diseases. This study aimed to determine whether the wound healing response after an abdominal incision leads to increased matrix metalloproteinase (MMP)-9 activity locally, contributing to peritoneal metastasis. MATERIALS AND METHODS: Metastatic tumors were initiated in C57bl/6J male mice (8wk of age) using a peritoneal injection model with syngeneic MC38 murine colon cancer cells; appropriate control mice also were studied. Injections were performed into the peritoneum in the right lower quadrant. We then observed the occurrence and rate of peritoneal metastasis for each group. RESULTS: By making an incision into the abdominal wall of mice, an inflammatory response was induced at the wound site. The inflammatory response initiated by the wound, in turn, increased the proliferation of mesothelial cells and increased inflammatory cell numbers locally, which contributed to an increase in parietal peritoneal metastases. In addition, the wound healing process increased the expression of pro-inflammatory cytokines and the number of inflammatory cells in the peritoneum. Moreover, MMP-9 in the modeled postoperative injury setting increased the number and severity of peritoneal metastases. CONCLUSIONS: Thus, we conclude that wound-associated inflammation enhances pro-MMP-9 expression, which plays a key role in the growth and progression of cancer cells associated with peritoneal metastases.

Diagnostic and therapeutic challenges in hepatic epithelioid hemangioendothelioma.

BACKGROUND: Epithelioid hemangioendothelioma is a very rare, low-grade vascular tumor known to arise in soft tissues and visceral organs. Clinical diagnosis of hepatic epithelioid hemangioendothelioma remains a challenge, and although it is frequently managed with a liver transplant due to its multifocal nature, recurrence is a common complication. METHODS: We review recent advances in the diagnosis of hepatic epithelioid hemangioendothelioma, including major genetic breakthroughs, and discuss efforts to reduce post-liver transplant recurrence of hepatic epithelioid hemangioendothelioma.

Increased diacylglycerols characterize hepatic lipid changes in progression of human nonalcoholic fatty liver disease; comparison to a murine model.

BACKGROUND AND AIMS: The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and progression to cirrhosis. While differences in liver lipids between disease states have been reported, precise composition of phospholipids and diacylglycerols (DAG) at a lipid species level has not been previously described. The goal of this study was to characterize changes in lipid species through progression of human NAFLD using advanced lipidomic technology and compare this with a murine model of early and advanced NAFLD. METHODS: Utilizing mass spectrometry lipidomics, over 250 phospholipid and diacylglycerol species (DAGs) were identified in normal and diseased human and murine liver extracts. RESULTS: Significant differences between phospholipid composition of normal and diseased livers were demonstrated, notably among DAG species, consistent with previous reports that DAG transferases are involved in the progression of NAFLD and liver fibrosis. In addition, a novel phospholipid species (ether linked phosphatidylinositol) was identified in human cirrhotic liver extracts. CONCLUSIONS: Using parallel lipidomics analysis of murine and human liver tissues it was determined that mice maintained on a high-fat diet provide a reproducible model of NAFLD in regards to specificity of lipid species in the liver. These studies demonstrated that novel lipid species may serve as markers of advanced liver disease and importantly, marked increases in DAG species are a hallmark of NAFLD. Elevated DAGs may contribute to altered triglyceride, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) levels characteristic of the disease and specific DAG species might be important lipid signaling molecules in the progression of NAFLD.

Intraoperative blood loss predicts hemorrhage-related reoperation after orthotopic liver transplantation.

Postoperative hemorrhage after orthotopic liver transplantation (OLT) may require early reoperative intervention. Previous studies have shown intraoperative transfusion requirement as a main determinant of reoperative intervention after OLT. The goal of this study was to develop an intraoperative hemorrhage model predicting need for reoperation after OLT. A single institution, retrospective review of adult primary OLT patients from January 2002 to 2008 was conducted. Multivariate logistical regression analysis was performed to identify predictors of reoperation due to postoperative hemorrhage. Secondary analysis was conducted on patients in the reoperation group managed with temporary open abdomen techniques. Four hundred and ten primary transplantations were performed with 59 patients (14.4%) requiring reoperation. The adjusted odds of reoperation when intraoperative blood loss (IBL) increases from 1.5 L to 10.0 L is 2.48 [95% confidence interval: (1.18, 5.31)]. IBL of 10.0 L predicts a 19.4 per cent probability of reoperation. Patients managed with open abdomen (n = 8) exhibited a significant IBL difference (16.0 L vs. 6.0 L, P < 0.001) when compared with the closed abdomen cohort. Our results indicate that intraoperative blood loss is the primary predictor of reoperation after OLT and provide a hemorrhage threshold to guide postoperative management of complicated OLT patients.

Rapid extravasation and establishment of breast cancer micrometastases in the liver microenvironment.

To examine the interplay between tumor cells and the microenvironment during early breast cancer metastasis, we developed a technique for ex vivo imaging of murine tissue explants using two-photon microscopy. Cancer cells in the liver and the lung were compared by imaging both organs at specific time points after the injection of the same polyomavirus middle T-initiated murine mammary tumor cell line. Extravasation was greatly reduced in the lung compared with the liver, with 56% of tumor cells in the liver having extravasated by 24 hours, compared with only 22% of tumor cells in the lung that have extravasated. In the liver, imaged cells continually transitioned from an intravascular location to an extravascular site, whereas in the lung, extravasation rates slowed after 6 hours. Within the liver microenvironment, the average size of the imaged micrometastatic lesions increased 4-fold between days 5 and 12. Histologic analysis of these lesions determined that by day 12, the micrometastases were heterogeneous, consisting of both tumor cells and von Willebrand factor-positive endothelial cells. Further analysis with intravenously administered lectin indicated that vessels within the micrometastatic tumor foci were patent by day 12. These data present the use of two-photon microscopy to directly compare extravasation times in metastatic sites using the same tumor cell line and highlight the differences in early events and metastatic patterns between two important secondary sites of breast cancer progression with implications for future therapy.

Laparoscopic and open surgery for right colonic diverticulitis.

The purpose of this study is to evaluate the safety and effectiveness of laparoscopic surgery by comparing laparoscopic and conventional surgery of right colonic diverticulitis (RCD). Among 124 patients who were treated for RCD from January 1997 to July 2007, we enrolled 54 patients who received resection therapy of RCD. Patients were divided into two groups: laparoscopic (LAP; n=19) and conventional (CON; n=35) surgery groups according to the respective surgical modality. The diverticulectomy (DIV; n=46) and right colectomy (COL; n=8) groups were also compared according to operative methods. There were significant differences between preoperative diagnosis and selection of the operative method and between RCD type and selection of operative method. However, there were no significant differences between preoperative diagnosis and selection of laparoscopic surgery and between RCD type and selection of laparoscopic surgery. The Kaplan-Meier estimated recurrence risk for all patients also showed no significant differences between LAP and CON and DIV and COL (P = 0.413). The Kaplan-Meier-estimated RCD-free period after surgery was 92.7 months (limited to 100 months). Laparoscopic surgery of RCD is an effective and safety method as a result of no differences in clinical data between conventional and laparoscopic surgery.

Selective visualization of cyclooxygenase-2 in inflammation and cancer by targeted fluorescent imaging agents.

Effective diagnosis of inflammation and cancer by molecular imaging is challenging because of interference from nonselective accumulation of the contrast agents in normal tissues. Here, we report a series of novel fluorescence imaging agents that efficiently target cyclooxygenase-2 (COX-2), which is normally absent from cells, but is found at high levels in inflammatory lesions and in many premalignant and malignant tumors. After either i.p. or i.v. injection, these reagents become highly enriched in inflamed or tumor tissue compared with normal tissue and this accumulation provides sufficient signal for in vivo fluorescence imaging. Further, we show that only the intact parent compound is found in the region of interest. COX-2-specific delivery was unambiguously confirmed using animals bearing targeted deletions of COX-2 and by blocking the COX-2 active site with high-affinity inhibitors in both in vitro and in vivo models. Because of their high specificity, contrast, and detectability, these fluorocoxibs are ideal candidates for detection of inflammatory lesions or early-stage COX-2-expressing human cancers, such as those in the esophagus, oropharynx, and colon.

Antimetastatic role of Smad4 signaling in colorectal cancer.

BACKGROUND & AIMS: Transforming growth factor (TGF)-beta signaling occurs through Smads 2/3/4, which translocate to the nucleus to regulate transcription; TGF-beta has tumor-suppressive effects in some tumor models and pro-metastatic effects in others. In patients with colorectal cancer (CRC), mutations or reduced levels of Smad4 have been correlated with reduced survival. However, the function of Smad signaling and the effects of TGF-beta-receptor kinase inhibitors have not been analyzed during CRC metastasis. We investigated the role of TGF-beta/Smad signaling in CRC progression. METHODS: We evaluated the role of TGF-beta/Smad signaling on cell proliferation, migration, invasion, tumorigenicity, and metastasis in Smad4-null colon carcinoma cell lines (MC38 and SW620) and in those that transgenically express Smad4. We also determined the effects of a TGF-beta-receptor kinase inhibitor (LY2109761) in CRC tumor progression and metastasis in mice. RESULTS: TGF-beta induced migration/invasion, tumorigenicity, and metastasis of Smad4-null MC38 and SW620 cells; incubation with LY2109761 reversed these effects. In mice, LY2109761 blocked metastasis of CRC cells to liver, inducing cancer cell expression of E-cadherin and reducing the expression of the tumorigenic proteins matrix metalloproteinase-9, nm23, urokinase plasminogen activator, and cyclooxygenase-2. Transgenic expression of Smad4 significantly reduced the oncogenic potential of MC38 and SW620 cells; in these transgenic cells, TGF-beta had tumor suppressor, rather than tumorigenic, effects. CONCLUSIONS: TGF-beta/Smad signaling suppresses progression and metastasis of CRC cells and tumors in mice. Loss of Smad4 might underlie the functional shift of TGF-beta from a tumor suppressor to a tumor promoter; inhibitors of TGF-beta signaling might be developed as CRC therapeutics.

Selective laparoscopic management of adhesive small bowel obstruction using CT guidance.

Small bowel obstruction after intra-abdominal surgery is a common cause of morbidity necessitating reoperation. The aim of this study was to determine the feasibility of and indications for laparoscopic surgery for acute adhesive small bowel obstruction (AASBO). We conducted a retrospective review of all patients with AASBO who underwent laparoscopic adhesiolysis at a major university medical center. Laparoscopic treatment was performed successfully in 16 patients, and conventional treatment was performed in 13 patients. The rate of conversion from laparoscopic to open was 16.7 per cent. In 15 of 16 total patients who underwent laparoscopic surgery, laparoscopic bandlysis was performed and one patient underwent laparoscopic adhesiolysis. Laparoscopic surgery was performed successfully in nine who had a single adhesive band demonstrated on an abdominal CT, and conventional surgery was performed in all 10 patients without a single adhesive band identified radiographically. Abdominal CT scans facilitate the selection of operative approach for AASBO based on preoperative identification of the obstruction site. Laparoscopic adhesiolysis is a safe and effective treatment modality for patients with AASBO with a single band or single transition zone identified by preoperative imaging.

Prognostic value of CEA and CA 19-9 tumor markers combined with cytology from peritoneal fluid in colorectal cancer.

BACKGROUND: Early diagnosis and management of peritoneal metastases from colorectal cancer patients are difficult clinical challenges. The aims of this study were to evaluate the clinical significance of tumor markers and cytology in peritoneal effusions (PE) and peritoneal irrigation fluid (PI) and to determine their value as prognostic indicators in this disease. METHODS: Two hundred thirty-four consecutive patients who underwent abdominal surgery for colorectal cancer from January 2006 to December 2007 were included, and tumor markers and cytology in PE and PI were analyzed prospectively. RESULTS: The incidence of free cancer cells retrieved from peritoneal samples was 7.9%. Cytology was positive in 40.0% by Papanicolaou and Giemsa staining, 73.3% by hematoxylin and eosin staining of cell blocks, and 66.7% by carcinoembryonic antigen (CEA) and calretinin immunohistochemistry. Multivariate analysis revealed that peritoneal CEA and cancer antigen (CA) 19-9 in PI were correlated with peritoneal metastasis and cytology. Level of peritoneal fluid CEA was statistically significantly correlated with recurrence and peritoneal metastatic recurrence in patients with negative peritoneal cytology. Cytology, peritoneal CEA, and peritoneal CA 19-9 showed correlations with cancer-free survival and overall survival. CONCLUSIONS: These correlations demonstrate the importance of continuous follow-up of peritoneal metastasis if there is positive cytology or an increase in CEA and CA 19-9 in peritoneal fluid.

Previously unreported high-grade complications of adrenalectomy.

BACKGROUND: Serious complications of adrenalectomy are rare but the incidence may be underestimated if they occur outside major referral centers. We report five cases of high-grade complications after adrenalectomy that have not been previously described. METHODS: The records of five cases of adrenalectomy performed at outside hospitals were reviewed. Four cases were referred for management of complications and one for medical-legal review. The nature of the adrenal lesion, operative approach, complication(s), and subsequent clinical course and complication management were assessed. Both open adrenalectomy (OA) and laparoscopic adrenalectomy (LA) cases were included. RESULTS: Operative indications were pheochromocytoma (N = 3), aldosteronoma (N = 1), and a nonfunctioning 6-cm hypervascular mass (N = 1). Complications of adrenalectomy included: case 1--complete transection of the porta hepatitis during right LA resulting in hepatic failure requiring emergent liver transplantation; case 2--ligation of the hepatic artery during right OA resulting in recurrent cholangitis and bile duct sclerosis requiring liver transplantation; case 3--ligation of the left ureter during LA resulting in postoperative hydronephrosis and loss of renal function; case 4--loss of left kidney function after OA, likely secondary to renal artery ligation ultimately requiring laparoscopic nephrectomy; case 5--LA of a normal adrenal gland for a 6-cm hypervascular mass thought to be arising from the adrenal gland. Three-month postoperative imaging demonstrated a persistent mass and the patient underwent hand-assisted laparoscopic nephrectomy for a left upper pole renal cell carcinoma that was missed at the time of LA. CONCLUSION: Despite the generally low morbidity of adrenalectomy, serious and potentially life-threatening complications can occur. Surgeon inexperience may be a factor in the occurrence of some of these complications which have not been previously described.

A clinical comparative analysis of crush/clamp, stapler, and dissecting sealer hepatic transection methods.

INTRODUCTION: Several methods for hepatic parenchymal division exist. The primary aim was to assess differences in postoperative bile leaks, operative blood loss, and margin status between three transection methods: crush/clamp (CC), stapler (SP), or dissecting sealer (DS). METHODS: A single institution, retrospective cohort study was performed on data collected over a three-year period in patients undergoing elective liver resection using the CC, SP, or DS. Patients were excluded if multiple methods of transection were used or for intraoperative death. The association of bile leak with transection type was assessed. A logistic regression model was tested to assess if blood loss was associated with the covariates of transection method, use of portal inflow occlusion, extent of liver resection, and other concurrent major operations. RESULTS: Analyses included 141 patients. The stapler method was quicker than the other methods (p=0.01). The risk of postoperative bile leak was no different between CC, SP, and DS transection methods (p=0.23). There was no difference in mean blood loss or transfusions; however, hepatectomies performed with DS were associated with an increased risk of blood loss > or = 1000 mL compared to CC (p=0.04). There were no differences in mean surgical margin between the three methods. CONCLUSION: The risk of bile leaks was not different between the three methods. While mean blood loss was similar, hepatectomy performed with the DS was associated with an increased risk of having operative blood loss > or = 1000 mL compared to CC. Margins were equal by all methods. The stapler method was quicker.

The diagnostic criteria for right colonic diverticulitis: prospective evaluation of 100 patients.

BACKGROUND AND AIMS: In this study, we evaluate prospective diagnostic criteria and propose a clinical scoring system for the evaluation of patients suspected to have right colonic diverticulitis (RCD) prospectively. PATIENTS AND METHODS: One hundred adult patients, who were clinically suspected to have appendicitis or RCD, and in whom we were not able to preoperatively rule out appendicitis, were examined prospectively. Patients were scored upon clinical presentation based on major diagnostic criteria included (1) no migration pain to the right lower quadrant; (2) a leukocyte count <10,000/mm(3); (3) lateralized abdominal pain, and (4) a history of right colonic diverticulum (two points each). Minor diagnostic criteria (one point each) included (1) a history of right lower quadrant abdominal pain; (2) no symptoms of nausea or vomiting; (3) symptoms of constipation or diarrhea, and (4) abdominal pain for at least seven days. For patients in whom the diagnostic score exceeded two points, a contrast enhanced computed tomography (CT) scan of the abdomen was performed. RESULTS: Thirteen patients had a final diagnosis of RCD. These diagnostic criteria demonstrated a sensitivity of 85%, a specificity of 68%, a positive predictive value of 28%, a negative predictive value of 97%, and a diagnostic accuracy of 70%. Among the 38 patients examined with CT, diagnoses for acute diverticulitis included nine true positives, 26 true negatives, two false positives, and one false negative. CONCLUSION: Performing CT scans after application of these diagnostic criteria gave a superior preoperative diagnostic rate for patients with RCD.

Functional colonography of Min mice using dark lumen dynamic contrast-enhanced MRI.

Dark lumen MRI colonography detects colonic polyps by minimization of the intestinal lumen signal intensity. Here we validate the use of perfluorinated oil as an intestinal-filling agent for dark lumen MRI studies in mice, enabling the physiological characterization of colonic polyps by dynamic contrast-enhanced MRI. In control and Min (multiple intestinal neoplasia) mice with and without pretreatment with oral dextran sodium sulfate (DSS), polyps as small as 0.94 mm diameter were consistently identified using standard 2D gradient echo imaging (voxel size, 0.23 x 0.16 x 0.5 mm). In serial studies, polyp growth rates were heterogeneous with an average approximately 5% increase in polyp volume per day. In DSS-treated control mice the colon wall contrast agent extravasation rate constant, K(trans), and extravascular extracellular space volume fraction, v(e), values were measured for the first time and found to be 0.10 +/- 0.03 min(-1) and 0.23 +/- 0.09, respectively. In DSS-treated Min mice, polyp K(trans) values (0.09 +/- 0.04 min(-1)) were similar to those in the colon wall but the v(e) values were substantially lower (0.16 +/- 0.03), suggesting increased cellular density. The functional dark-lumen colonography approach described herein provides new opportunities for the noninvasive assessment of gastrointestinal disease pathology and treatment response in mouse models.

Liver transplantation for hepatocellular carcinoma: current role and future opportunities.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. It represents the fifth most common cancer worldwide, and one whose incidence is on the rise. Liver cancer is the third most common cause of cancer mortality globally and thus a major health concern worldwide. Therapeutic options for this tumor include surgical resection, local ablative therapies, and systemic treatment. Liver transplantation has emerged as a highly effective treatment for patients with HCC, particularly in the setting of significant underlying liver disease. Current protocols in transplantation for this tumor utilize strict size criteria and staging (TNM classification) to select patients for this therapy. Selection criteria for liver transplantation for HCC that are accepted in the U.S. include: 1 tumor < 5cm, no greater than three tumor nodules, each less than 3cm in diameter 3) no macroscopic invasion of blood vessels or lymph nodes, and no extra-hepatic spread of tumor. Eligibility criteria and immunosuppression strategies are continuing to evolve in this field. Nonetheless, in appropriately selected patients, liver transplantation may provide a cure for HCC with survival rates equal to that of liver transplantation for end-stage liver disease (ESLD) from other causes. Liver transplantation has been established as one of the principal treatment modalities for this difficult disease.

Resident stromal cell-derived MMP-9 promotes the growth of colorectal metastases in the liver microenvironment.

Colorectal cancer, the second leading cause of cancer deaths in the United States, has a high probability of metastasizing to the liver. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases that are implicated in cancer metastasis and many aspects of tumor progression. Using a splenic injection experimental metastasis model, mice that are genetically deficient in MMP-9 demonstrated a nearly 2-fold decrease in liver weight compared with wild type (WT) mice following injection with MC38 syngeneic colorectal cancer cells. Bioluminesence imaging data demonstrates an early negative effect on tumor growth in MMP-9 null mice when compared with WT controls. Reconstitution of the bone marrow in MMP-9-/- mice with cells competent to produce MMP-9 did not recapitulate the WT phenotype of overwhelming burden of metastatic disease in the liver. In situ hybridization revealed the presence of MMP-9 mRNA in both MC38 tumor cells and in surrounding stromal cells, and immunostaining with anti MMP-9 was consistent with MMP-9 expression by resident liver Kupffer cells. Stromal-derived MMP-9 contributes to the establishment and growth of colorectal metastases in the liver. Stromal MMP-9 was derived from resident cells, most likely Kupffer cells, as opposed to infiltrating bone marrow-derived cells and the effect of stromal MMP-9 was independent of expression of MMP-9 by tumor cells. Stromal-derived MMP-9 may represent an important target for selective inhibition in the treatment of metastases. (c) 2007 Wiley-Liss, Inc.

Serum sickness following rabbit antithymocyte-globulin induction in a liver transplant recipient: case report and literature review.

Thymoglobulin (Genzyme, Cambridge, MA) is an antithymocyte globulin preparation used for induction immunosuppression therapy in solid organ transplantation. It is being utilized with increasing frequency in orthotopic liver transplantation (OLT) in an effort to minimize or delay the use of calcineurin inhibitors due to their inherent nephrotoxicity. Experience with thymoglobulin in OLT remains limited. We report a case of serum sickness in a patient who received thymoglobulin following OLT. The patient experienced intermittent fevers, polyarthralgia, and acute renal failure 9 days after completion of thymoglobulin administration. The patient's symptoms resolved rapidly and completely with a course of intravenous steroids. We review a set of diagnostic criteria for serum sickness and emphasize the importance of early recognition of the process. Early treatment of serum sickness with steroids or plasmapheresis is highly effective and can reduce unnecessary morbidity from this unusual sequela of induction immunosuppression with antithymocyte globulin.

Warm hepatic ischemia-reperfusion promotes growth of colorectal carcinoma micrometastases in mouse liver via matrix metalloproteinase-9 induction.

Surgical resection remains the best treatment for colorectal metastases isolated to the liver; however, 5-year survival rates following liver resection are only 40% to 50%, with liver recurrence being a significant reason for treatment failure. The ischemia-reperfusion (I/R) injury incurred during liver surgery can lead to cellular dysfunction and elevations in proinflammatory cytokines and matrix metalloproteinases (MMP). In rodents, I/R injury to the liver has been shown to accelerate the outgrowth of implanted tumors. The mechanism for increased tumor growth in the setting of liver I/R injury is unknown. To investigate the effect of I/R on tumor growth, an experimental model was used whereby small hepatic metastases form after 28 days. Mice subjected to 30 min of 70% liver ischemia at the time of tumor inoculation had significantly larger tumor number and volume, and had elevated MMP9 serum and liver tissue MMP9 as evidenced by zymography and quantitative real-time PCR. Mice treated with doxycycline, a broad-spectrum MMP inhibitor, had reduced MMP9 levels and significantly smaller tumor number and volume in the liver. MMP9-null mice were used to determine if the effects of doxycycline were due to the absence of stromal-derived MMP9. The MMP9-null mice, with or without doxycycline treatment, had reduced tumor number and volume that was equivalent to wild-type mice treated with doxycycline. These findings indicate that hepatic I/R-induced elevations in MMP9 contribute to the growth of metastatic colorectal carcinoma in the liver and that postresection MMP9 inhibition may be clinically beneficial in preventing recurrence following hepatic surgery.