Ronald P. DeMatteo

Butyrate inhibits seeding and growth of colorectal metastases to the liver in mice

BACKGROUNDnThe short-chain fatty acid butyrate inhibits growth of colorectal carcinoma cells in vitro. Mevalonate, a short-chain fatty acid structurally and metabolically related to butyrate, is important in signal transduction and is essential for cell growth. We investigated butyrates effects on seeding and growth of colorectal tumor cells metastatic to the liver in vivo and hypothesized that butyrates antiproliferative effects are associated with inhibition of mevalonate-mediated cell growth.nnnMETHODSnHepatic metastases were induced by injecting 1 x 10(5) MC-26 (N-methyl-N-nitrosourea-induced murine colorectal carcinoma) cells into the spleen of BALB/c mice. Mice were treated with a continuous intravenous infusion of butyrate (2 gm/kg/day) for 7 days starting 24 hours before tumor cells were injected. Study variables included liver weight and number of hepatic surface metastases. Proliferation studies on MC-26 cells were performed in vitro to examine the effects of butyrate alone or combined with mevalonate or mevastatin (an inhibitor of mevalonate synthesis).nnnRESULTSnButyrate reduced seeding and growth of colorectal tumor cells in vivo. Mevalonate diminished butyrates antiproliferative action in vitro, whereas mevastatin potentiated this effect.nnnCONCLUSIONSnThese studies (1) show that butyrate inhibits seeding and growth of hepatic colorectal metastases in vivo, (2) associate butyrates antiproliferative effects with inhibition of mevalonate-mediated cell growth, and (3) indicate that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors may have synergistic antiproliferative effects when combined with butyrate.

Cellular Immunity Delimits Adenoviral Gene Therapy Strategies for the Treatment of Neoplastic Diseases

AbstractBackground: Adenoviral gene therapy is a promising new approach for the treatment of neoplastic diseases. To design rational clinical trials and distinguish the effects of therapeutic transgene expression from those caused by viral infection alone, the immune response to the vector must be understood. In these experiments, we further define cellular immunity to recombinant adenovirus.n Methods: The immune response to hepatic adenoviral gene transfer was studied in infected mice by depleting T cells with an anti-CD3 antibody, measuring splenocyte cytokine production, determining the impact of transgene expression on inflammation, and assessing liver MHC protein expression.n Results: The cellular immune response to recombinant adenovirus is (1) averted by T lymphocyte depletion, (2) marked by a TH1 response with increased IL-2 production, (3) directed against both the transgene product and viral proteins, and (4) associated with increased hepatocyte MHC Class I expression.n Conclusions: It is necessary to take into consideration the constraints imposed by the immunogenicity of recombinant adenovirus and its transient transgene expression in the clinical application of adenoviral gene transfer for the treatment of cancer.

Adenoviral-mediated gene transfer to murine small intestine is more efficient in neonates than adults

PURPOSEnThe authors sought to assess the feasibility of in vivo gene transfer to the small intestine using recombinant adenovirus in neonatal and adult mice.nnnMETHODSnH5.010CMVlacZ is a replication-defective, E1-deleted human type 5 adenovirus, which contains the lacZ gene under the control of a cytomegalovirus promoter and enhancer. The lacZ gene was used as a marker because its gene product, beta-galactosidase, is readily detected by X-gal histochemistry. Sixty neonatal (3 to 5 days old) and 45 adult (6 to 8 weeks old) C57BL/6 mice were investigated. Intestinal gene transfer was attempted with H5.010CMVlacZ by intraperitoneal (i.p.), intraluminal (IL), and intramural (i.m.) injection. Based on prior studies, the optimal dose of H5.010CMVlacZ was 1 x 10(8) plaque forming units (pfu/mL). Control animals received saline injections. Gene transfer on repeat administration of adenovirus has been shown to be prevented by neutralizing antibody. To determine if neonatal inoculation induced a humoral immune response, neonates (n = 5) that received i.p. injections were rechallenged with intravenous H5.010CMV alkphos, a similar adenoviral construct containing the alkaline phosphatase marker gene. Serum samples were analyzed by Western blot to detect the presence of adenoviral-specific antibody.nnnRESULTSnGene transfer to neonatal small intestine was successful by IL gastric (n = 8/10), IL jejunal (n = 9/10) and i.p. (n = 10/10) routes 2 days after injection. Macroscopic staining was present in 90% of standardized 2-cm small bowel segments. Transgene expression was identified in intestinal smooth muscle, serosa, and epithelium. Gene transfer to the adult small intestine was successful by IL jejunal (n = 4/5), i.m. (n = 5/5), and i.p. (n = 1/5) injection of adenoviruslacZ with focal staining (< 5% of 2-cm segments) in epithelium including crypts, muscle, and serosa. Three weeks after i.p. H5.010CMVlacZ in neonates, intravenous injection with H5.010CMValkphos resulted in hepatic transgene expression (n = 4/5) that was indistinguishable from a primary intravenous inoculation; persistent, lacZ expression was not detectable in the liver or intestine (n = 0/5). Western blot analysis detected adenoviral-specific antibodies after adult IM but not after neonatal i.p. injection. Furthermore, 3 weeks after neonatal i.p. injection repeat administration by the i.m. route was successful (n = 4/ 4).nnnCONCLUSIONnGene transfer to neonatal and adult small intestine is feasible using recombinant adenovirus and is more efficient in neonates as indicated by increased surface area of marker gene expression, effectiveness of intraperitoneal delivery, and the ability to readminister recombinant adenovirus.

Divergent mechanisms of insulin-like growth factor I and II on rat hepatocyte proliferation

Insulin-like growth factors I and II are peptides with a structural homology for proinsulin, and are involved in hepatocyte proliferation. IGF-I and IGF-II, however, have different metabolic roles, and their mechanisms of action are incompletely known. We hypothesized that IGF-I and IGF-II act by different signal transduction pathways. To test this hypothesis, hepatocytes from 200 g male Sprague-Dawley rats were isolated by a two-step collagenase perfusion technique and plated at a density of 10(5) cells/16 mm Primaria plate. Proliferation was measured by [3H]thymidine ([3H]thy) incorporation into DNA, and an autoradiographic nuclear labeling index (LI). To analyze signal transduction, cyclic AMP (cAMP) levels were measured 5 min after addition of reagents by a radioimmunoassay. Reagents (doses) used were: IGF-I (2 nM), IGF-II (2 nM), the inhibitory peptide somatostatin-14 (SS14) (10 nM), and the adenylyl cyclase antagonist dideoxyadenosine (DDA) (10 microM). A summary of the findings is as follows: (1) IGF-I stimulates [3H]thy, LI and cAMP accumulation. (2) IGF-II stimulates [3H]thy and LI but not cAMP; (3) IGF-I but not IGF-II effects are inhibited by SS14 and DDA. We conclude that the hepatotrophic effects of IGF-I and IGF-II occur by different mechanisms: IGF-I is cAMP-dependent, IGF-II is cAMP-independent.

Safe and Successful Yttrium-90 Resin Microsphere Radioembolization in a Heavily Pretreated Patient with Chemorefractory Colorectal Liver Metastases after Biliary Stent Placement above the Papilla

We report a case of safe and successful yttrium-90 resin microsphere radioembolization in a patient with a long history of multiple recurrent colon cancer hepatic metastases progressing after hepatic resections, hepatic arterial chemotherapy, and multiple regimens of systemic chemotherapy. One month prior to radioembolization, a biliary stent was placed above the level of the ampulla to relieve tumor-related biliary obstruction and normalize bilirubin levels.

A preoperative prognostic model to predict surgical success in patients with perihilar cholangiocarcinoma: GASPERSZ et al.

Patients with resectable perihilar cholangiocarcinoma (PHC) on imaging have a substantial risk of metastatic or locally advanced disease, incomplete (R1) resection, and 90‐day mortality. Our aim was to develop a preoperative prognostic model to predict surgical success, defined as a complete (R0) resection without 90‐day mortality, in patients with resectable PHC on imaging.