P5369Alpha-V integrin regulates the contribution of PW1+ cells to cardiac fibrosis

Background

Activated cardiac fibroblasts produce extracellular matrix proteins that accumulate during cardiac fibrosis. We have recently shown that PW1 is expressed in a subset of cardiac stromal cells and that cardiac PW1+ cells represent a cellular source of fibroblasts in the ischemic hearts.

Purpose

We aimed to further identify new cell surface markers expressed by cardiac PW1+ cells and to investigate their role in the fibrogenic behavior of these cells.

Methods and results

We first performed transcriptomic and proteomic profiling of FACS-isolated cardiac PW1+ from normal and ischemic hearts. RNA-sequencing output files were processed with bioinformatics algorithms to identify 378 specific cell-surface markers for cardiac PW1+ cells. By comparing these candidates with the proteomic profile, we then cross-identified 9 cell surface proteins primarily involved in cell motility, adhesion to the matrix, inflammatory response and response to wounding. One of these candidates (i.e., aV-integrin or CD51) was expressed in almost all cardiac PW1+ cells (93±1%), and was predominantly found in cells expressing PW1 in the myocardium. Cardiac PW1+ cells showed a predominant expression of aVβ1 complex which is known to mediate fibrosis through TGF-beta activation in a number of tissues. The transfer of isolated cardiac PW1+CD51+ cells into ischemic hearts was associated with fibrosis development. We further demonstrated that inhibition of aV-integrin in cardiac PW1+ cells reduces their profibrotic gene expression profile and their ability to differentiate into fibroblasts. Lastly, a pharmacological blockade of aV-integrin improved cardiac function and animal survival following myocardial infarction coupled with a reduced infarct size and fibrotic lesion.

Conclusions

These data identify a targetable pathway that regulates cardiac fibrosis in response to an ischemic injury and demonstrate that pharmacological inhibition of aV-integrin leads to reduced pathological outcomes following cardiac ischemia.

Acknowledgement/Funding

Fondation Leducq (grant 13CVD01, CardioStemNet project), Fédération Française de Cardiologie and Era-CVD (ANR-16-ECVD-0011-03, Clarify project)

Humidity-enhanced sub-ppm sensitivity to ammonia of covalently functionalized single-wall carbon nanotube bundle layers

A low-cost method for carbon nanotubes (CNTs) network production from solutions on flexible polyethylene naphthalate substrates has been adopted to prepare high quality and well characterized SWCNT bundle layers to be used as the active layer in chemiresistor gas sensors. Two types of SWCNTs have been tested: pristine SWCNTs, deposited from a surfactant solution, and covalently functionalized SWCNTs, deposited from a dimethyl-acetamide solution. The humidity effects on the sensitivity of the SWCNTs network to NH₃ have been investigated. The results show that relative humidity favors the response to NH₃, confirming recent theoretical predictions. The COOH-functionalized sample displays the largest response owing to both its hydrophilic nature, favoring the interaction with H₂O molecules, and its largest surface area. Compared to data available in the literature, the present sensors display a remarkable sensitivity well below the ppm range, which makes them quite promising for environmental and medical applications, where NH₃ concentrations (mostly of the order of tens of ppb) have to be detected.

OBP-401-GFP telomerase-dependent adenovirus illuminates and kills high-metastatic more effectively than low-metastatic triple-negative breast cancer in vitro

We previously described the development of a highly-invasive, triple-negative breast cancer (TNBC) variant using serial orthotopic implantation of MDA-MB-231 human breast cancer in nude mice. The isolated variant is highly invasive in the mammary gland and metastasized to lymph nodes in 10 of 12 mice compared with 2 of 12 of the parental cell line. OBP-401 is a telomerase-dependent cancer-specific, green fluorescent protein (GFP)-expressing adenovirus. OBP-401 was used to infect parental MDA-MB-231P cells and high-metastatic MDA-MB-231H and MDA-MB-231HLN isolated from a lymph node metastasis and MDA-MB-231HLM isolated from a lung metastasis. Time-course imaging showed that OBP-401 labeled MDA-MB-231HP, MDA-MB-231HLN, and MDA-MB-231HLM cells more brightly than MDA-MB-231 parental cells. OBP-401 killed MDA-MB-231H, MDA-MB-231HLN, and MDA-MB-231HLM cells more efficiently than MDA-MB-231P parental cells. These results indicate that OBP-401 could infect, label and then kill high-metastatic MDA-MB-231 more efficiently than low-metastatic MDA-MB-231.

Simple preoperative risk scale accurately predicts perioperative mortality following esophagectomy for malignancy

Surgery remains one of the major treatment options available to patients with esophageal cancer, with high mortality in certain cohorts. The aim of this study was to develop a simple preoperative risk scale based on patient factors, hospital factors, and tumor pathology to predict the risk of perioperative mortality following esophagectomy for malignancy. The Nationwide Inpatient Sample database was used to create the risk scale. Patients who underwent open or laparoscopic transhiatal and transthoracic esophageal resection were identified using International Classification of Diseases, 9th edition codes. Patients <18 years and those with peritoneal disease were excluded. Multivariate logistic regressions were used to define a predictive model of perioperative mortality and to create a simple risk scale. From 1998 to 2011, a total of 23 751 patients underwent esophagectomy. The observed overall perioperative mortality rate for this cohort was 7.7%. Minimally invasive techniques, and operations performed in higher volume centers were protective, whereas increasing age, comorbidities and diagnosis of squamous cell carcinoma were independent predictors of mortality. Based on this population, a risk scale from 0-16 was created. The calibration revealed a good agreement between the observed and risk scale-predicted probabilities. A set of sensitivity/specificity analyses was then performed to define normal (score 0-7) and high risk (score 8-16) patients for clinical practice. Mortality in patients with a score of 0-7 ranged from 1.3-7.6%, compared with 10.5-34.5% in patients with a score of 8-16. This simple preoperative risk scale may accurately predict the risk of perioperative mortality following esophagectomy for malignancy and can be used as a clinical tool for preoperative counseling.

Maternal perinatal undernutrition modifies lactose and serotranferrin in milk: relevance to the programming of metabolic diseases?

A close link between intrauterine growth restriction and development of chronic adult diseases such as obesity, diabetes, and hypertension has been established both in humans and animals. Modification of growth velocity during the early postnatal period (i.e., lactation) may also sensitize to the development of metabolic syndrome in adulthood. This suggests that milk composition may have long-lasting programming/deprogramming metabolic effects in the offspring. We therefore assess the effects of maternal perinatal denutrition on breast milk composition in a food-restricted 50% (FR50) rat model. Monosaccharides and fatty acids were characterized by gas chromatography, and proteins were profiled by surface-enhanced laser desorption/ionization-time-of-flight analysis in milk samples from FR50 and control rat dams. Milk analysis of FR50 rats demonstrated that maternal undernutrition decreases lactose concentration and modulates lipid profile at postnatal day 10 by increasing the unsaturated fatty acids/saturated fatty acids and diminishes serotransferrin levels at postnatal day 21. Our data indicate that maternal perinatal undernutrition modifies milk composition both quantitatively and qualitatively. These modifications by maternal nutrition open new perspectives to identify molecules that could be used in artificial milk to protect from the subsequent development of metabolic diseases.

P5-02-05: Real-Time Subcellular Imaging of Breast Cancer Cell Attachment in Blood Vessels Using GFP-Labeled Paxillin in Live Mice

Background: Paxillin is involved in the assembly of focal adhesions. We wish to visualize paxillin behavior in breast cancer cells in vivo, as well as in vitro.

Materials and Methods: Dual-photon confocal microscopy was used to image paxillin behavior by linking it to GFP. MDA-MB-231 human breast cancer cells expressing paxillin-GFP were imaged in vitro and in vivo adhering and trafficking in blood vessels in mice. 106 paxillin-GFP expressing breast cancer cells were injected in the epigastric cranialis vein.

Results: In vitro, round breast cancer cells had greater paxillin movement than stretched cancer cells as seen by fluorescence imaging. Paxillin-GFP breast cancer cells in the epigastric cranialis vein were initially rounded and had GFP-expressing protrusions. At later timepoints, many paxillin-GFP-expressing breast cancer cells stretched. The breast cancer cells then extravasated and subsequently grew around the outer surface of the blood vessel after one week. Two weeks after injection, paxillin-GFP expressing breast cancer cells were imaged migrating along the vessel wall. Most of the paxillin-GFP expressing breast cancer cells were stretched and were not mobile. With anti-VEGF treatment, paxillin was observed in round structures within the cells rather than stretched structures and paxillin movement within the cell was arrested.

Discussion: These results demonstrate that breast cancer cells brightly expressing paxillin-GFP and two-photon confocal microscopy can allow the visualization of the behavior of paxillin within breast cancer cells during adhesion and migration along the walls of blood vessels, as well as during anti-angiogenesis therapy.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-02-05.

Breast carcinoma metastatic to the gallbladder and urinary bladder

We present a patient with a history of infiltrating lobular breast carcinoma that metastasized to both the biliary and urinary tract after a ten year disease-free period following mastectomy and chemoradiotherapy. The patient presented with acute cholecystitis; imaging and histopathology revealed infiltrating lobular carcinoma of the gallbladder and urinary bladder. This report emphasizes the importance of long-term follow up in patients with a history of breast cancer and maintaining a high degree of suspicion for diagnosis of metastatic disease.

Targeted therapy of spinal cord glioma with a genetically modified Salmonella typhimurium

OBJECTIVE

Spinal cord tumours are highly malignant and often lead to paralysis and death due to their infiltrative nature, high recurrence rate and limited treatment options. In this study, we measured antitumour efficacy of the Salmonella typhimurium A1-R tumour-targeting bacterium strain, administered systemically or intrathecally, to spinal cord cancer in orthotopic mouse models.

MATERIALS AND METHODS

Tumour fragments of U87-RFP were implanted by surgical orthotopic implantation into the dorsal site of the spinal cord. Five and 10 days after transplantation, eight mice in each group were treated with A1-R (2 x 10(7) CFU/200 microL i.v. injection or 2 x 10(6) CFU/10 microL intrathecal injection).

RESULTS

Untreated mice showed progressive paralysis beginning at day 6 after tumour transplantation and developed complete paralysis between 18 and 25 days. Mice treated i.v. with A1-R had onset of paralysis at approximately 11 days and at 30 days; five mice developed complete paralysis, while the other three mice had partial paralysis. Mice treated by intrathecal injection of A1-R had onset of paralysis at approximately 18 days and one mouse was still not paralysed at day 30. Only one mouse developed complete paralysis at day 30 in this group. Intrathecally treated animals had a significantly better survival than the i.v. treated group as well as over the control group.

CONCLUSIONS

These results suggest that S. typhimurium A1-R monotherapy can effectively treat spinal cord glioma.

Clinically-relevent orthotopic metastatic models of pancreatic cancer imageable with fluorescent genetic reporters

This article describes authors' cumulative experience with the development and preclinical application of clinically-relevant, metastatic orthotopic mouse models of pancreatic cancer made imageable with genetic reporters. These models utilize the human pancreatic cancer cell lines which have been genetically engineered to selectively express high levels of green fluorescent protein (GFP) or red fluorescent protein (RFP). Tumors with fluorescent genetic reporters are established subcutaneously in nude mice, and fragments of the subcutaneous tumors are then surgically transplanted onto the pancreas. Loco-regional tumor growth and distant metastasis of these orthotopic implants occurs spontaneously and rapidly throughout the abdo-men in a manner consistent with clinical human disease. Highly specific, high-resolution, real-time quantitative fluorescence imaging of tumor growth and metastasis may be achieved in vivo without the need for contrast agents, invasive techniques, or expensive imaging equipment. A high correlation between florescence optical imaging, magnetic resonance imaging, and ultrasound in these models has been demonstrated. Transplantation of RFP-expressing tumor fragments onto the pancreas of GFP- or cyan fluorescent protein-expressing transgenic mice was used to facilitate visualization of tumor-host interaction between the pancreatic cancer cells and host-derived stroma and vasculature. Such in vivo models have enabled visualization in real time and acquisition of images of the progression of pancreatic cancer in the live animal, the models also demonstrate the real-time antitumor and antimetastatic effects of several novel therapeutic strategies on pancreatic malignancy. These fluorescent models are therefore powerful and reliable tools with which to investigate metastatic human pancreatic cancer and novel therapeutic strategies directed against it.

A color-coded orthotopic nude-mouse treatment model of brain-metastatic paralyzing spinal cord cancer that induces angiogenesis and neurogenesis

OBJECTIVE

Cancer of the spinal cord is highly malignant and often leads to paralysis and death. A realistic mouse model would be an important benefit for the better understanding and treatment of spinal cord glioma.

MATERIALS AND METHODS

To develop an imageable, patient-like model of this disease, U87 human glioma tumour fragments (expressing red fluorescent protein), were transplanted by surgical orthotopic implantation into the spinal cord of nontransgenic nude mice or transgenic nude mice expressing nestin-driven green fluorescent protein (ND-GFP). In ND-GFP mice, GFP is expressed in nascent blood vessels and neural stem cells. The animals were treated with temozolomide or vehicle control.

RESULTS

The intramedullary spinal cord tumour grew at the primary site, caused hind-limb paralysis and also metastasized to the brain. Temozolomide inhibited tumour growth (P<0.01) and prevented metastasis, as well as prevented paralysis in four mice and delayed paralysis in two mice of the six tested (P=0.005). In the ND-GFP-expressing host, ND-GFP cells staining positively for neuronal class III-beta-tubulin or CD31, surrounded the tumour. These results suggest that the tumour stimulated both neurogenesis and angiogenesis, respectively.

CONCLUSION

A patient-like model of spinal cord glioma was thus developed, which can be used for the discovery of new agents, including those that inhibit invasion and metastasis of the disease as well as those that prevent paralysis.

Road soil retention of Pb leached from MSWI bottom ash

Municipal solid waste incinerator (MSWI) bottom ash may be used as a road construction material; it potentially contains however a sizable quantity of heavy metals, which under the effect of rainfall infiltration through the road structure can be leached out from the material and infiltrate into the underlying soil. An eco-compatibility assessment of MSWI bottom ash reuse in road construction applications necessitates examining the solubility and retention of heavy metals in road soils. This study is dedicated to Pb transfer, sorption and desorption (NEN 7341 standard test) within various soils. These experiments yield results relative to the interaction between road soils and an MSWI bottom ash leachate representative of a "fresh" product, with a high leaching potential. For the soils investigated, the sorption of lead varies between 90% and 99%. For an extraction at pH 7, Pb release is very low (<2%) for all soils, while at pH 4 leaching varies between 4% and 47%. This work shows that Pb may be fixed by some types of road soil in mostly stable forms.

The alpha2beta1 integrin mediates the malignant phenotype on type I collagen in pancreatic cancer cell lines

Pancreatic cancer is characterised by a hallmark desmoplastic response that includes upregulated expression of the extracellular matrix, and type I collagen in particular. Recent studies indicate that pancreatic cancer cells stimulate type I collagen synthesis in adjacent stellate cells, and that this upregulated type I collagen expression promotes the malignant phenotype in tumour cells as defined by increased proliferation, resistance to chemically induced apoptosis, and increased tumorigenesis. The integrin specificity of this interaction between type I collagen and tumour cells was not identified, however. In the present study, we examined eight pancreatic cancer cell lines for adhesion, proliferation, and migration, on types I and IV collagen, fibronectin, laminin, and vitronectin, as well as integrin expression. Our results indicate, for the overwhelming majority of cell lines, that type I collagen promotes the strongest adhesion, proliferation, and migration relative to the other substrates tested. Utilising function-blocking monoclonal antibodies directed against particular integrin subunits in cell adhesion and migration inhibition assays, we demonstrate further that the malignant phenotype on type I collagen is mediated specifically by the α₂β₁ integrin. These results identify α₂β₁ integrin-mediated adhesion to type I collagen as a potential therapeutic target in the treatment of pancreatic cancer.

Physiological characterisation of Arabidopsis mutants affected in the expression of the putative regulatory protein PII

The PII signal transducing protein is involved in carbon/nitrogen (C/N) sensing in bacteria and cyanobacteria. In higher plants the function of the PII homolog GLB1 is not known. GLB1 transcripts were found in all plant organs tested, while in Arabidopsis leaves GLB1 expression and PII protein levels were not significantly affected by either the day/night cycle or N-nutrition. Its putative regulatory role in plants has been studied by analysing Arabidopsis thaliana T-DNA insertion lines in the GLB1 gene. These PII mutants showed an 80% (PIIV1 mutant) and 100% (PIIS2 mutant) reduced AtGLB1 transcript level and no detectable PII protein. They did not display an altered growth or developmental phenotype when grown under non-limiting conditions suggesting that the PII protein does not play a crucial role in plants. However, in vitro grown PII mutants did show a higher sensitivity to nitrite (NO (2) (-) ) compared to the wild-type plants. This observation is reminiscent of the role of PII in the regulation of NO (2) (-) metabolism in cyanobacteria. Furthermore, when grown hydroponically, the PII mutants displayed a slight increase in carbohydrate (starch and sugars) levels in response to N starvation and a slight decrease in the levels of ammonium (NH (4) (+) ) and amino acids (mainly Gln) in response to NH (4) (+) resupply. Although the phenotypic changes are rather small in the mutant lines, these data support the hypothesis of a subtle involvement of the PII protein in the regulation of some steps of primary C and N metabolism.

Methioninase cancer gene therapy with selenomethionine as suicide prodrug substrate

In this study, we report a novel approach to gene-directed enzyme prodrug therapy for cancer. This gene therapy strategy exploits the toxic pro-oxidant property of methylselenol, which is released from selenomethionine (SeMET) by cancer cells with the adenoviral-delivered methionine alpha,gamma-lyase (MET) gene cloned from Pseudomonas putida. In MET-transduced tumor cells, the cytotoxicity of SeMET is increased up to 1000-fold compared with nontransduced cells. A strong bystander effect occurred because of methylselenol release from MET gene-transduced cells and uptake by surrounding tumor cells. Methylselenol damaged the mitochondria via oxidative stress and caused cytochrome c release into the cytosol, thereby activating the caspase cascade and apoptosis. Adenoviral MET-gene/SeMET treatment also inhibited tumor growth in rodents and significantly prolonged their survival. Recombinant adenovirus-encoding MET gene-SeMET treatment thereby offers a new paradigm for cancer gene therapy.

Antimetastatic efficacy of adjuvant gemcitabine in a pancreatic cancer orthotopic model

Gemcitabine is a promising new agent that has been recently studied for palliation of advanced (stage IV) unresectable pancreatic cancer. We hypothesized that adjuvant gemcitabine would reduce recurrence and metastases following surgical resection of pancreatic cancer. To test this hypothesis, we evaluated gemcitabine on a green fluorescent protein (GFP) transductant of the human pancreatic cancer cell line BxPC-3 (BxPC-3-GFP) using surgical orthotopic implantation (SOI) in nude mice. GFP enabled high resolution fluorescent visualization of primary and metastatic growth. Five weeks after SOI, the mice were randomized into three groups: Group I received exploratory laparotomy only. Group II underwent surgical resection of the pancreatic tumor without further treatment. Group III underwent tumor resection followed by adjuvant treatment with gemcitabine, 100 mg/kg every three days for a total of four doses, starting two days after resection. The mice were sacrificed at thirteen weeks following implantation and the presence and location of recurrent tumor was recorded. Gemcitabine reduced the recurrence rate to 28.6% compared to 70.6% with resection only (P = 0.02) and reduced metastatic events 58% in the adjuvant group compared to resection only. This study, demonstrating that gemcitabine is effective as adjuvant chemotherapy post-pancreatectomy, suggests this new indication of the drug clinically.

Chronologically-specific metastatic targeting of human pancreatic tumors in orthotopic models

Pancreatic cancer is a highly metastatic disease that responds poorly to currently-available treatment. In order to better visualize and understand the chronology and specificity of metastatic targeting of pancreatic cancer, two human pancreatic cancer cell lines, expressing green fluorescent protein (GFP), were studied in orthotopic models. MIA-PaCa2-GFP and BxPC-3-GFP tumor fragments were transplanted by surgical orthotopic implantation (SOI) to the nude mouse pancreas for fluorescence visualization of the chronology of pancreatic tumor growth and metastatic targeting. BxPC-3-GFP tumors developed rapidly in the pancreas and spread regionally to the spleen and retroperitoneum as early as six weeks. Distant metastases in BxPC-3-GFP were rare. In contrast, MIA-PaCa-2-GFP grew more slowly in the pancreas but rapidly metastasized to distant sites including liver and portal lymph nodes. Regional metastases in MIA-PaCa-2-GFP were rare. These studies demonstrate that pancreatic cancers have highly specific and individual 'seed-soil' interactions governing the chronology and sites of metastatic targeting.

Value of three-dimensional US for optimizing guidance for ablating focal liver tumors

PURPOSE

To determine if three-dimensional ultrasound (3D US), by nature of its ability to simultaneously evaluate structures in three orthogonal planes and to study relationships of devices to tumor(s) and surrounding anatomic structures from any desired orientation, adds significant additional information to real-time 2D US used for placement of devices for ablation of focal liver tumors.

MATERIALS AND METHODS

Sixteen patients underwent focal ablation of 23 liver tumors during two intraoperative cryoablation (CA) procedures, three intraoperative radiofrequency ablation (RFA) procedures, 11 percutaneous ethanol injections (PEI) procedures, and six percutaneous RFA procedures. After satisfactory placement of the ablative device(s) with 2D US guidance, 3D US was used to reevaluate adequacy to device position. Information added by 3D US and resultant alterations in device deployment were tabulated.

RESULTS

3D US added information in 20 of 22 (91%) procedures and caused the operator to readjust the number or position of ablative devices in 10 of 22 (45%) of procedures. Specifically, 3D US improved visualization and confident localization of devices in 13 of 22 (59%) procedures, detected unacceptable device placement in 10 of 22 (45%), and determined that 2D US had incorrectly predicted device orientation to a tumor in three of 22 (14%).

CONCLUSIONS

Compared to conventional 2D US, 3D US provides additional relationship information for improved placement and optimal distribution of ablative agents for treatment of focal liver malignancy.

Human pancreatic adenocarcinomas express parathyroid hormone-related protein

PTH-related protein (PTHrP) is expressed in many common malignancies such as breast and prostate cancer and can regulate their growth. Little is known, however, about the role of PTHrP in pancreatic adenocarcinoma. To study PTHrP in pancreatic exocrine cancer, we studied its expression in pancreatic cancer cell lines and surgical specimens. Eight human pancreatic adenocarcinoma cell lines were evaluated: AsPC-1, BxPC-3, Capan-1, CFPAC-1, MIA PaCa-2, PANC-1, PANC-28, and PANC-48. Murine monoclonal antibodies to the amino-terminal (1-34), mid-region (38-64), and carboxyl-terminal peptides (109-141) of PTHrP were used to identify cellular PTHrP and secreted PTHrP, including Western blotting and immunocytochemical staining for PTHrP from each cell line. Cellular PTHrP was detected in all cell line extracts by both Western blotting and immunoassay. CFPAC-1, derived from a pancreatic liver metastasis, had the highest concentration of PTHrP, and MIA PaCa-2, derived from primary pancreatic adenocarcinoma, had the lowest. PTHrP was localized by immunocytochemical staining in the cytoplasm in all but one cell line, and both nuclear and cytoplasmic immunostaining were observed in the MIA PaCa-2 and PANC-1 cells. Secretion of PTHrP into cell medium was also observed for each cell line and paralleled intracellular PTHrP levels. Evidence for differential processing of PTHrP expression was provided by studies demonstrating different patterns of PTHrP among the cell lines when assessed by PTHrP immunoassays directed against different PTHrP peptides. In specific, PTHrP secretion measured by a PTHrP-(38-64) assay was highest for BxPC-3, whereas the highest levels of secreted PTHrP-(109-141) occurred in CFPAC-1 and PANC-1. Growth of AsPC-1 cells was stimulated in a dose-dependent manner by PTHrP-(1-34). Immunostaining from archival tissue of patients with pancreatic adenocarcinoma revealed strong PTHrP expression in all 14 specimens. All patients were eucalcemic preoperatively. These results demonstrate that PTHrP is commonly expressed in pancreatic cancer. Our data suggest that PTHrP may have growth-regulating properties in pancreatic adenocarcinoma cells, but further studies are required.

Cytotoxicity, apoptosis, and viral replication in tumor cells treated with oncolytic ribonucleotide reductase-defective herpes simplex type 1 virus (hrR3) combined with ionizing radiation

The viral ribonucleotide reductase (rR)-defective herpes simplex type-1 (HSV-1) virus (hrR3) has been shown previously to preferentially replicate in and kill tumor cells. This selectivity is associated with tumor cell up-regulation of mammalian rR. Ionizing radiation (IR) is currently used in the therapy of many malignancies, including glioblastoma, cervical carcinoma, and pancreatic carcinoma. IR has been shown to up-regulate mammalian rR in tumor cells and appears to increase the efficacy of at least one non-rR-deleted HSV-1 strain in an in vivo tumor model. Here, we test the hypothesis that a single therapeutic radiation fraction will increase the replication and toxicity of hrR3 for malignant cell lines in vitro. PANC-1 pancreatic carcinoma, U-87 glioblastoma, and CaSki cervical carcinoma cell lines were treated with varying doses of IR and subsequently infected with hrR3 or KOS (wild-type HSV-1 strain). Cell survival was then measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and trypan blue exclusion cytometry. At 72 hours posttreatment, irradiation with 2 Gy reduced survival from 100% to 76% in noninfected cells, from 61% to 48% in KOS-infected cells, and from 39% to 27% in hrR3-infected PANC-1 cells. As such, analysis of variance indicated that the toxicity of the two modalities was additive. Similar additivity was seen in U-87 MG and CaSki cells. Absolute survival of hrR3-infected or KOS-infected PANC-1 cells decreased as a function of time after treatment (24-72 hours) and multiplicity of infection (MOI) (0.05-5.0). However, the relative decrease in survival with the addition of IR to hrR3 or KOS in PANC-1 cells was not markedly affected by altering MOI (0.05-5.0), time (24-72 hours), radiation dose (2-20 Gy), or cell culture conditions (confluent/growth arrested). We used fluorescence-activated cell sorter analysis with the cationic lipophilic dye DiOC6 to quantify a reduction in mitochondrial membrane potential that'is associated with apoptosis. Fluorescence-activated cell sorter analysis indicated increased apoptosis in both hrR3- and IR-treated cells at 48-72 hours, with hrR3 alone producing the most induction. Viral yields from PANC-1 cells after irradiation and infection were examined. No significant differences were seen between irradiated and nonirradiated cells in viral replication, with hrR3 producing single-step titers of 3.1 +/- 0.9 x 10(5) and 4.0 +/- 1.2 x 10(5) plaque-forming units/mL in nonirradiated and irradiated cells. Thus, complementary toxicity was seen between IR and hrR3 or KOS, regardless of cell type, time, MOI, IR dose, or culture conditions, without evidence of augmented apoptosis or viral replication.

Factors influencing survival after resection for periampullary neoplasms

BACKGROUND

The purpose of this study was to determine predictors of survival after resection for periampullary neoplasms.

METHODS

Over a 15-year period, 208 patients underwent laparotomy for periampullary neoplasms. Data were analyzed to assess predictors of survival.

RESULTS

Pathologic examination showed pancreatic cancer (n = 136; 65%), ampullary cancer (n = 28; 13%), distal common bile duct cancer (n = 10; 5%), duodenal cancer (n = 4; 2%), neuroendocrine tumor (n = 11; 5%), cystadenocarcinoma (n = 4; 2%), cystadenoma (n = 5; 2%), and other (n = 10; 5%). A total of 129 patients underwent pancreatic resection (71 Whipples, 35 total pancreatectomies, 21 distal pancreatectomies, and 2 partial pancreatectomies) whereas 79 patients were found to be unresectable and underwent palliative bypass and/or biopsy. Median survival was 20.4 months for resectable patients versus 4.5 months for unresectable patients (P<0.001). Of the 129 resected patients, factors significantly (P<0.05) favoring long-term survival on univariate analysis included well-differentiated histology, common bile duct or ampullary adenocarcinoma, early stage, tumor diameter <2 cm, negative margins, and absence of lymph node metastases, perineural, or vascular invasion. Age, sex, race, and type of procedure had no influence on survival. On multivariate analysis, only tumor differentiation appeared independently related to survival. Using Kendall's tau analysis, tumor type and grade correlated significantly with all other predictors.

CONCLUSIONS

Of all variables studied, tumor type and poor tumor differentiation in periampullary neoplasms appear to be markers that predict a constellation of other adverse findings.

Methioninase gene therapy of human cancer cells is synergistic with recombinant methioninase treatment

Results obtained over the past 40 years have demonstrated that tumor cells of all types tested have an elevated growth requirement for methioninase compared with normal cells. Recombinant methioninase (rMETase) cloned from Pseudomonas putida has been found previously to be an effective antitumor agent attributable to deprivation of the extracellular methionine source of the tumor. To degrade intracellular methioninase, we have now developed an adenoviral vector inserted with the P. putida methioninase (MET) gene (rAd-MET). The in vitro efficacy of rAd-MET was tested on the OVCAR-8 human ovarian cancer cell line, the HT1080 human fibrosarcoma cell line, and human normal fibroblasts. rAd-MET transduction of OVACAR-8 and HT1080 resulted in high levels of methioninase expression up to 10% or more of the total protein of the cells, depending on the multiplicity of infection. The IC50 of rAd-MET for OVCAR-8 cells in 96-well plates was approximately 2 x 106 plaque-forming units (pfu)/well. The IC50 of control adenovirus (control-rAd) was 4 x 10(7) pfu/well, 20 times higher than rAd-MET. In the presence of the IC50 of 2 x 10(6) pfu/well of rAd-MET, the addition of 0.025 units/ml of rMETase, which is 25% of the IC50, resulted in a 90% inhibition of tumor cell number. This indicated that rAd-MET enhanced the efficacy of rMETase. In contrast, 2 x 10(6) pfu/well of control-rAd in combination with 0.025 units/ml of rMETase had an efficacy of only 10% inhibition of cell number. The synergistic effect of the combination of rMETase and rAd-MET was quantitated by calculating the combination index (CI). The CIs for all combinations of rAd-MET and rMETase tested on OVCAR-8 were <0.7 with a mean of 0.5, indicating synergy. Similar synergy of rAd-MET and rMETase was seen on HT1080 human fibrosarcoma cells with a mean of 0.74. In contrast, the CIs of all combinations of rMETase and control adenovirus concentrations tested on both cell lines had a mean CI of approximately 1, which indicated that this combination had only an additive effect. The normal fibroblasts, on the other hand, appeared relatively resistant to the MET gene because in the presence of rMETase, 2.5 x 10(7) pfu/well of rAd-MET or control rAd had almost an identical effect on cell survival. The selectively strong synergy of rAd-MET and rMETase on cancer cells allows reduced levels of each agent to be used, thus decreasing potential side effects.

Whole-body optical imaging of green fluorescent protein-expressing tumors and metastases

We have imaged, in real time, fluorescent tumors growing and metastasizing in live mice. The whole-body optical imaging system is external and noninvasive. It affords unprecedented continuous visual monitoring of malignant growth and spread within intact animals. We have established new human and rodent tumors that stably express very high levels of the Aequorea victoria green fluorescent protein (GFP) and transplanted these to appropriate animals. B16F0-GFP mouse melanoma cells were injected into the tail vein or portal vein of 6-week-old C57BL/6 and nude mice. Whole-body optical images showed metastatic lesions in the brain, liver, and bone of B16F0-GFP that were used for real time, quantitative measurement of tumor growth in each of these organs. The AC3488-GFP human colon cancer was surgically implanted orthotopically into nude mice. Whole-body optical images showed, in real time, growth of the primary colon tumor and its metastatic lesions in the liver and skeleton. Imaging was with either a trans-illuminated epifluorescence microscope or a fluorescence light box and thermoelectrically cooled color charge-coupled device camera. The depth to which metastasis and micrometastasis could be imaged depended on their size. A 60-microm diameter tumor was detectable at a depth of 0.5 mm whereas a 1, 800-microm tumor could be visualized at 2.2-mm depth. The simple, noninvasive, and highly selective imaging of growing tumors, made possible by strong GFP fluorescence, enables the detailed imaging of tumor growth and metastasis formation. This should facilitate studies of modulators of cancer growth including inhibition by potential chemotherapeutic agents.

Surgical strategy for the treatment of medullary thyroid carcinoma

OBJECTIVE

To evaluate surgical complications, patterns of lymph node metastases, and calcitonin response to compartment-oriented lymphadenectomy in patients with primary or recurrent medullary thyroid carcinoma (MTC).

SUMMARY BACKGROUND DATA

The majority of patients with invasive MTC have metastasis to regional lymph nodes at the time of diagnosis, as evidenced by the frequent finding of persistently elevated calcitonin levels after thyroidectomy and the high rates of recurrence in the cervical lymph nodes reported in retrospective studies. These data have provided the rationale for surgeons to perform a more extensive lymphadenectomy at the time of initial thyroidectomy and to consider reoperative cervical lymphadenectomy in patients with persistently elevated calcitonin levels after thyroidectomy.

METHODS

Forty patients underwent surgery for MTC from 1991 to 1997 (23 sporadic cases, 17 familial cases). Patients were divided into three groups based on whether they had undergone previous thyroidectomy and on the results of standardized staging studies performed after referral to the authors' institution. Group 1 (11 patients) had received no previous surgery; group 2 (13) underwent thyroidectomy before referral and had an elevated calcitonin level without radiologic evidence of local regional or distant metastases; and group 3 (16) underwent thyroidectomy before referral and had an elevated calcitonin level with radiologic evidence of local-regional recurrence. The central neck compartment was dissected in all patients; preoperative staging and the extent of previous surgery dictated the need for lateral (modified radical) neck dissection. After primary or reoperative surgery, calcitonin levels were assessed.

RESULTS

All patients had major reductions in postoperative calcitonin levels. Seven (29%) of 24 patients in groups 1 and 2 achieved normal calcitonin values compared with only 1 (6%) of 16 in group 3. Postoperative complications included seven cases (17%) of permanent hypoparathyroidism; five (71%) of these occurred in group 3. There were no iatrogenic recurrent laryngeal nerve injuries; one patient required recurrent nerve resection to achieve complete tumor extirpation. At a median follow up of 35 months, local recurrence was documented in 5 (13%) of 40 patients.

CONCLUSIONS

Compartment-oriented lymphadenectomy performed early in the course of MTC is safe and may return calcitonin levels to normal in up to 25% of carefully selected patients. However, reoperation for bulky cervical disease (group 3) rarely results in normal calcitonin levels and is associated with a high incidence of permanent hypoparathyroidism.

Recombinant adenovirus expressing wild-type p53 is antiangiogenic: a proposed mechanism for bystander effect

Angiogenesis is required for the growth and progression of malignancies. Recent studies have demonstrated that genetic alterations may accompany acquisition of the angiogenic phenotype. The tumor suppressor gene p53 is most frequently mutated in human cancers and is also known to be a transcriptional regulator of a variety of genes. Here, we investigated the antiangiogenic effect of the wild-type p53 (wt-p53) gene transfer on a human non-small cell lung cancer cell line. Mutant p53-expressing H226Br non-small cell lung cancer cells were transduced with the wt-p53 gene using a recombinant adenoviral vector (Ad5CMVp53) and applied to semiquantitative reverse transcription-PCRs for the detection of altered mRNA expression of angiogenic and/or antiangiogenic factors. In vivo neovascularization assay of Ad5CMVp53-infected cells was then performed using a membrane-diffusion chamber system s.c. transplanted in nu/nu mice. We also evaluated the effect of Ad5CMVp53-infected H226Br cells on nontransduced tumor cells in vivo by s.c. inoculating mixture of cells into nu/nu mice. Ad5CMVp53 infection markedly inhibited the expression of an angiogenic factor, vascular endothelial growth factor, and increased the expression of a novel antiangiogenic factor, brain-specific angiogenesis inhibitor 1, resulting in reduced neovascularization in vivo. Mixing experiments showed that tumor cells transduced with the wt-p53 gene inhibited the in vivo tumor growth of adjacent nontransduced cells. Our data suggest that a recombinant adenovirus expressing the wt-p53 gene is antiangiogenic, which may explain, in part, the mechanism of the bystander effect induced by the wt-p53 gene transfer on adjacent tumor cells.

Reduced toxicity, attenuated immunogenicity and efficient mediation of human p53 gene expression in vivo by an adenovirus vector with deleted E1-E3 and inactivated E4 by GAL4-TATA promoter replacement

A recombinant adenovirus with deleted E1 and E3, and E4-inactivated by replacing the E4 promoter with a synthetic promoter composed of a minimal TATA box and five consensus yeast GAL4-binding site elements was developed and used to express the human tumor suppresser gene p53. The toxicity and immunogenicity of this vector and vector-mediated p53 gene expression in vivo were studied in immunocompetent C3H and C57BL/6 mice. Expression of the late viral gene product, hexon protein, was observed in C3H and C57BL/6 mice injected with E4 wild-type adenovirus constructs Adv-cmv-beta-Gal (BG), Adv-cmv-hp53 (WT), and empty E1- vector Adv-E4 (EW) 3 to 28 days after injection, but was undetectable in mice treated with E4 modified empty E1- vector Adv-GAL4 (EG) or Adv-cmv-hp53-GAL4 (G4). Expression of the p53 gene was observed in both WT- and G4-injected C3H and C57BL/6 mouse livers from days 3 to 28. Ten weeks after injection, p53 gene expression was still detected in G4-treated C57BL/6 mice at similar levels, but was not detectable in WT-treated mice. Vector-induced liver toxicity was evaluated by analyzing serum transaminases (SGOT and SGPT) activities. In all cases, SGOT and SGPT activities were markedly decreased in EG-treated C3H and C57BL/6 mice compared with those in EW-treated mice on days 3, 7 and 14 after injection. In C57BL/6 mice, the total anti-adenoviral CTL activities were two- to three-fold higher in animals treated with EW vector than in those treated with EG vector. These results suggest that inactivation of the E4 promoter efficiently diminished the viral replication and the late viral gene expression, reduced host immune response and consequently reduced toxicity and prolonged the duration of transgene expression in vivo.

Predictors of recurrence after local excision and postoperative chemoradiation therapy of adenocarcinoma of the rectum

BACKGROUND

Local excision of rectal cancer preserves anal continence, bladder function, and normal sexual function. However, local recurrence after excision remains a significant problem. To further define the indications for local excision, we analyzed possible factors predictive of recurrence after local excision of rectal cancer.

METHODS

The charts of all patients undergoing local excision of adenocarcinoma of the rectum between 1985 and 1995 at a single institution were reviewed. Patients with metastatic disease at the time of excision and patients treated preoperatively with chemoradiation therapy were excluded. All available slides were reviewed by a single pathologist, who assessed the depth of invasion; the presence or absence of vascular invasion, lymphatic invasion, perineural invasion, and lymphocytic infiltrate; the mucinous status; and the degree of differentiation. Using the log-rank test and Cox proportional hazards model, univariate and multivariate analyses were performed to identify predictors of recurrence.

RESULTS

Ninety patients underwent local excision, 46 transanally and 44 using a Kraske approach. The breakdown of patients by tumor stage was as follows: Tis, 13%; T1, 41%; T2, 30%; T3, 15%; and Tx, 1%. Sixty-eight percent of patients with T1 tumors were treated with postoperative radiotherapy; all patients with T2 or T3 tumors were treated postoperatively with or without 5-fluorouracil. The median duration of follow-up was 51 months. The median tumor diameter was 2.5 cm (range, 0.4 to 7 cm), and the median distance of the tumor from the anal verge was 4.5 cm (range, 1 to 10 cm). The 4-year actuarial local disease-free survival rate broken down by tumor stage was as follows: Tis, 100%; T1, 95%; T2, 80%; and T3, 73%. The median time to local recurrence was 23 months (range, 7 to 61 months). Multivariate analysis showed that only tumor stage and margin status were predictors of local recurrence.

CONCLUSIONS

Local excision and postoperative radiotherapy result in adequate local control of early stage (Tis and T1) adenocarcinoma of the rectum. Higher rates of recurrence were seen in patients with T2 and T3 tumors, especially in those with positive margins.

Adenovirus-mediated wild-type p53 tumor suppressor gene therapy induces apoptosis and suppresses growth of human pancreatic cancer [seecomments]

BACKGROUND

The p53 tumor suppressor gene is mutated in up to 70% of pancreatic adenocarcinomas. We determined the effect of reintroduction of the wild-type p53 gene on proliferation and apoptosis in human pancreatic cancer cells using an adenoviral vector containing the wild-type p53 tumor suppressor gene.

METHODS

Transduction efficiencies of six p53-mutant pancreatic cancer cell lines (AsPC-1, BxPC-3, Capan-1, CFPAC-1, MIA PaCa-2, and PANC-1) were determined using the reporter gene construct Ad5/CMV/beta-gal. Cell proliferation was monitored using a 3H-thymidine incorporation assay, Western blot analysis for p53 expression was performed, and DNA laddering and fluorescence-activated cell sorter analysis were used to assess apoptosis. p53 gene therapy was tested in vivo in a subcutaneous tumor model.

RESULTS

The cell lines varied in transduction efficiency. The MIA PaCa-2 cells had the highest transduction efficiency, with 65% of pancreatic tumor cells staining positive for beta-galactosidase (beta-gal) at a multiplicity of infection (MOI) of 50. At the same MOI, only 15% of the CFPAC-1 cells expressed the beta-gal gene. Adenovirus-mediated p53 gene transfer suppressed growth of all human pancreatic cancer cell lines in a dose-dependent manner. Western blot analysis confirmed the presence of the p53 protein product at 48 hours after infection. DNA ladders demonstrated increased chromatin degradation, and fluorescence-activated cell sorter analysis demonstrated a four-fold increase in apoptotic cells at 48 and 72 hours following infection with Ad5/CMV/p53 in the MIA PaCa-2 and PANC-1 cells. Suppression of tumor growth mediated by induction of apoptosis was observed in vivo in an established nude mouse subcutaneous tumor model following intratumoral injections of Ad5/CMV/p53.

CONCLUSIONS

Introduction of the wild-type p53 gene using an adenoviral vector in pancreatic cancer with p53 mutations induces apoptosis and inhibits cell growth. These data provide preliminary support for adenoviral mediated p53 tumor suppressor gene therapy of human pancreatic cancer.

Clinical, pathologic, and economic parameters of laparoscopic colon resection for cancer

BACKGROUND

The appropriateness of laparoscopic colon resection (LCR) as treatment for malignancy has been questioned.

METHODS

From 1992 to 1997, 91 patients were entered into a prospective study of LCR for cancer. Clinical, pathologic, and economic parameters of LCR were compared in a cohort of patients matched for age, tumor stage, and type of colectomy who underwent open colon resection (OCR) during the same time period.

RESULTS

With a median follow-up of 26 months, there were no significant differences in survival rate for patients in the LCR, converted colon resection, and OCR groups. There were no port-site recurrences and the number of lymph nodes harvested was similar among the procedures. Hospital stay was significantly shorter if laparoscopic resection was successful. Total hospital costs were similar for LCR and OCR; however, the costs were significantly higher for converted colon resection.

CONCLUSIONS

LCR is a sound oncologic procedure that can be performed with costs similar to OCR.

Gene therapy and pancreatic cancer

Adenocarcinoma of the pancreas is associated with a short survival due to frequent delays in diagnosis and the lack of effective systemic therapies. Advances in understanding the molecular basis of pancreatic cancer have allowed identification of molecular targets which are amenable to therapeutic intervention. Such targets include p53, K-ras, p16, and DPC-4. Gene therapy involves the transfer of genetic constructs which alter the neoplastic potential of the cancer cell. Vectors used in gene transfer include viral and non-viral methods. Presently, gene therapy of pancreatic cancer is limited to pre-clinical studies using in vitro and in vivo models. However, the initial results from these pre-clinical studies have been encouraging and will form the basis for clinical studies of gene transfer in patients with pancreatic cancer.

Reduction mammaplasty: its role in breast conservation surgery for early-stage breast cancer

Segmental resection and radiotherapy is an accepted alternative over mastectomy for small, staged breast malignancies. However, women with large, pendulous breasts have been documented to have poorer cosmetic outcomes when undergoing irradiation after breast conservative surgery compared with women with small- or medium-size breasts, thought to be caused by dose inhomogeneity. The purpose of this study was to evaluate the efficacy of combining reduction mammaplasty with breast conservative surgery to facilitate postoperative irradiation. Between 1988 and 1996, 10 women have undergone bilateral reduction mammaplasty for breast malignancy followed by radiation therapy at our center. All women wished to avoid mastectomy (average age, 59 years). All lesions were detected preoperatively on mammography. The average amount of tissue removed was 945 g per breast. A variety of reduction techniques were employed to include the malignant lesions. All patients received 50 Gy of radiation therapy delivered in 25 fractions following reduction mammaplasty during a 5-week period. Radiation therapy was usually initiated within 4 weeks following surgery. Follow-up is currently 37 months, with all patients being followed for at least 8 months. No patients have had complications from the surgery or radiation therapy. No local recurrent malignancies have been detected. Cosmesis has been good to excellent in all patients. Despite equivalent survival outcomes for mastectomy for early-stage breast cancer, certain women are not good candidates for breast conservation and radiation therapy. An alternative for women with large, pendulous breasts that combines breast conservation therapy and concurrent bilateral reduction mammaplasty should be considered. This combination, in selected women, provides good functional and cosmetic results, and at the same time minimizes the potential difficulties of radiation therapy.

Improved sentinel lymph node localization in patients with primary melanoma with the use of radiolabeled colloid

BACKGROUND

The purpose of this study was to determine whether the sentinel lymph node (SLN) localization technique, which uses blue dye and 99mTc-labeled sulfur colloid, provides advantages over blue dye alone in the management of patients with stages I and II cutaneous melanoma.

METHODS

The records of 626 consecutive patients with melanoma who underwent lymphatic mapping and SLN biopsy between 1991 and 1997 at the M.D. Anderson Cancer Center were reviewed. Lymphatic mapping was performed with isosulfan blue dye alone (n = 252) or in combination with 99mTc-labeled sulfur colloid accompanied by a hand-held gamma probe (n = 374). SLNs were defined as those that stained blue or demonstrated increased focal radiotracer uptake.

RESULTS

SLN identification rates improved from 87% (dye alone) to 99% (dye and colloid) (P < .0001) with the combined technique in all anatomic sites examined. The mean number of SLNs harvested from each basin was significantly greater in the patients mapped with dye and colloid (1.74 vs 1.31; P < .0001). Occult metastatic disease was identified in 17.5% of all patients and did not significantly differ between groups. In 92% of patients who had at least one positive SLN and were mapped with both agents, lymphatic metastases were identified in the SLN that contained the greatest radiotracer uptake.

CONCLUSIONS

SLN identification is enhanced by the addition of radiolabeled sulfur colloid and intraoperative use of the hand-held gamma probe and may identify SLNs missed by the blue dye alone. These data support the combined use of radiolabeled sulfur colloid and blue dye in lymphatic mapping procedures to improve the nodal staging of stages I and II melanoma.