The differential effects of metronomic gemcitabine and antiangiogenic treatment in patient-derived xenografts of pancreatic cancer: treatment effects on metabolism, vascular function, cell proliferation, and tumor growth.

BACKGROUND: Metronomic chemotherapy has shown promising activity against solid tumors and is believed to act in an antiangiogenic manner. The current study describes and quantifies the therapeutic efficacy, and mode of activity, of metronomic gemcitabine and a dedicated antiangiogenic agent (DC101) in patient-derived xenografts of pancreatic cancer. METHODS: Two primary human pancreatic cancer xenograft lines were dosed metronomically with gemcitabine or DC101 weekly. Changes in tumor growth, vascular function, and metabolism over time were measured with magnetic resonance imaging, positron emission tomography, and immunofluorescence microscopy to determine the anti-tumor effects of the respective treatments. RESULTS: Tumors treated with metronomic gemcitabine were 10-fold smaller than those in the control and DC101 groups. Metronomic gemcitabine, but not DC101, reduced the tumors' avidity for glucose, proliferation, and apoptosis. Metronomic gemcitabine-treated tumors had higher perfusion rates and uniformly distributed blood flow within the tumor, whereas perfusion rates in DC101-treated tumors were lower and confined to the periphery. DC101 treatment reduced the tumor's vascular density, but did not change their function. In contrast, metronomic gemcitabine increased vessel density, improved tumor perfusion transiently, and decreased hypoxia. CONCLUSION: The aggregate data suggest that metronomic gemcitabine treatment affects both tumor vasculature and tumor cells continuously, and the overall effect is to significantly slow tumor growth. The observed increase in tumor perfusion induced by metronomic gemcitabine may be used as a therapeutic window for the administration of a second drug or radiation therapy. Non-invasive imaging could be used to detect early changes in tumor physiology before reductions in tumor volume were evident.

Inhibition of VEGF induces cellular senescence in colorectal cancer cells.

Vascular endothelial growth factor (VEGF) inhibitors, such as bevacizumab, have improved outcomes in metastatic colorectal cancer (CRC). Recent studies have suggested that VEGF can delay the onset of cellular senescence in human endothelial cells. As VEGF receptors are known to be upregulated in CRC, we hypothesized that VEGF inhibition may directly influence cellular senescence in this disease. In our study, we observed that treatment with bevacizumab caused a significant increase (p < 0.05) in cellular senescence in vitro in several CRC cells, such as MIP101, RKO, SW620 and SW480 cells, compared to untreated or human IgG-treated control cells. Similar results were also obtained from cells treated with a VEGFR2 kinase inhibitor Ki8751. In vivo, cellular senescence was detected in MIP101 tumor xenografts from 75% of mice treated with bevacizumab, while cellular senescence was undetectable in xenografts from mice treated with saline or human IgG (p < 0.05). Interestingly, we also observed that the proportion of senescent cells in colon cancer tissues obtained from patients treated with bevacizumab was 4.4-fold higher (p < 0.01) than those of untreated patients. To understand how VEGF inhibitors may regulate cellular senescence, we noted that among the two important regulators of senescent growth arrest of tumor cells, bevacizumab-associated increase in cellular senescence coincided with an upregulation of p16 but appeared to be independent of p53. siRNA silencing of p16 gene in MIP101 cells suppressed bevacizumab-induced cellular senescence, while silencing of p53 had no effect. These findings demonstrate a novel antitumor activity of VEGF inhibitors in CRC, involving p16.

Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) overexpression in pancreatic ductal adenocarcinoma correlates with poor survival.

BACKGROUND: Pancreatic ductal adenocarcinoma is a lethal disease with a 5-year survival rate of 4% and typically presents in an advanced stage. In this setting, prognostic markers identifying the more aggressive tumors could aid in management decisions. Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3, also known as IMP3 or KOC) is an oncofetal RNA-binding protein that regulates targets such as insulin-like growth factor-2 (IGF-2) and ACTB (beta-actin). METHODS: We evaluated the expression of IGF2BP3 by immunohistochemistry using a tissue microarray of 127 pancreatic ductal adenocarcinomas with tumor grade 1, 2 and 3 according to WHO criteria, and the prognostic value of IGF2BP3 expression. RESULTS: IGF2BP3 was found to be selectively overexpressed in pancreatic ductal adenocarcinoma tissues but not in benign pancreatic tissues. Nine (38%) patient samples of tumor grade 1 (n = 24) and 27 (44%) of tumor grade 2 (n = 61) showed expression of IGF2BP3. The highest rate of expression was seen in poorly differentiated specimen (grade 3, n = 42) with 26 (62%) positive samples. Overall survival was found to be significantly shorter in patients with IGF2BP3 expressing tumors (P = 0.024; RR 2.3, 95% CI 1.2-4.8). CONCLUSIONS: Our data suggest that IGF2BP3 overexpression identifies a subset of pancreatic ductal adenocarcinomas with an extremely poor outcome and supports the rationale for developing therapies to target the IGF pathway in this cancer.

CXCR3 antagonist NBI-74330 attenuates atherosclerotic plaque formation in LDL receptor-deficient mice.

OBJECTIVE: The chemokine receptor CXCR3 is implicated in migration of leukocytes to sites of inflammation. Antagonizing CXCR3 may be a strategy to inhibit inflammation-induced leukocyte migration and subsequently reduce atherosclerosis. We used the CXCR3 specific antagonist NBI-74330 to block CXCR3-mediated signaling in peritonitis and diet-induced atherosclerosis. METHODS AND RESULTS: Antagonizing CXCR3 with NBI-74330 resulted in a significant reduction in CD4+ T cell and macrophage migration to the peritoneal cavity, which was as shown in ex vivo migration studies totally CXCR3 dependent. Atherosclerotic lesion formation in the aortic valve leaflet area and the entire aorta was significantly inhibited in NBI-74330 treated mice. Lymph nodes draining from the aortic arch were significantly smaller in treated mice and were enriched in regulatory T cells and contained fewer activated T cells, whereas the markers for regulatory T cells within the lesion were enhanced after NBI-74330 treatment. CONCLUSIONS: This study shows for the first time that treatment with a CXCR3 antagonist results in attenuating atherosclerotic lesion formation by blocking direct migration of CXCR3+ effector cells from the circulation into the atherosclerotic plaque and by beneficially modulating the inflammatory response in the lesion and the lymph nodes draining from the atherosclerotic lesion.

Genome-wide expression analysis of therapy-resistant tumors reveals SPARC as a novel target for cancer therapy.

Overcoming resistance to chemotherapy and radiation therapy has been a difficult but important goal in the effort to cure cancer. We used gene-expression microarrays to identify differentially expressed genes involved in colorectal cancer resistance to chemotherapy and identified secreted protein, acidic and rich in cysteine (osteonectin) (SPARC) as a putative resistance-reversal gene by demonstrating low SPARC expression in refractory human MIP101 colon cancer cells. We were able to achieve restoration of their radiosensitivity and sensitivity to 5-fluorouracil and irinotecan by reexpression of SPARC in tumor xenografts. Moreover, treatment of mice with SPARC conferred increased sensitivity to chemotherapy and led to significant regression of xenografted tumors. The results show that modulation of SPARC expression affects colorectal cancer sensitivity to radiation and chemotherapy. SPARC-based gene or protein therapy may ameliorate the emergence of resistant clones and eradicate existing refractory clones and offers a novel approach to treating cancer.

Chronic advanced gastric cancer: clinicopathologic analysis of survival data.

Patients with advanced gastric cancer who survived 5 years or more were studied. They were divided into 2 groups: 31 who later died of their disease (chronic patients) and 33 who were apparently cured (cured patients). Each survivor was matched with a patient who died within 5 years (control patients). The clinical and pathologic features of each group were compared. The 5-year survivors were easily distinguished from the controls by histologic stage, size of neoplasm, intratumoral eosinophil counts, extent of fibrosis; and by most histologic classifications. Chronic patients resembled cured patients in mean age (56 years), stage, size, site, percentage with lymphatic and neural invasion, eosinophil counts, extent of fibrosis, and characteristics in most histologic classifications. Chronic cancers differed from cured cancers by having less venous invasion, fewer solid tumors, more mucinous carcinomas, a lesser proportion of intestinal to diffuse cancers (World Health Organization), and more intracellular mucin production (Goseki). Chronic cancers were lower stage and smaller with less lymphatic, venous, and neural invasion than controls. Their superior overall survival time was largely because of longer progression-free survival. We conclude that chronic advanced gastric cancer patients differ both from cured patients and control patients. The use of pathologic features in addition to the standard Lauren classification better separated the chronic cancers from the cured cancers and showed differences in behavior between histologic types.

Synthesis and structure-activity relationship of aminopyrimidine IKK2 inhibitors.

The synthesis and structure-activity relationship of a novel series of aminopyrimidines are exemplified. Results of key compounds from within this series in the E-selectin reporter cell assay are also reported.

Development of CXCR3 antagonists. Part 4: discovery of 2-amino-(4-tropinyl)quinolines.

The synthesis and biological evaluation of a novel series of 2-aminoquinoline substituted piperidines and tropanes incorporating a homotropene moiety is herein described. The series exhibits potent antagonism of the CXCR3 receptor and superior physicochemical properties. Compound 24d was found to be orally bioavailable, and PK/PD studies suggested it as a suitable tool for studying the role of CXCR3 in models of disease.

Development of CXCR3 antagonists. Part 3: Tropenyl and homotropenyl-piperidine urea derivatives.

The optimization of a series of 1-aryl-3-piperidinyl urea derivatives is described in which incorporation of tropenyl and homotropenyl moieties has led to significant improvements in activity and drug-like properties. Replacement of the central piperidine with an exo-tropanyl unit led to the identification of compound 15 which provides a combination of excellent potency against human and murine receptors, drug-like properties and pharmacokinetics, thus providing a valuable tool for the evaluation of CXCR3 antagonists in models of human disease.

Celiac Disease and Other Causes of Duodenitis.

CONTEXT: - Patients who receive an upper gastrointestinal endoscopic examination frequently have biopsies taken from the duodenum. Accurate interpretation of duodenal biopsies is essential for patient care. Celiac disease is a common clinical concern, but pathologists need to be aware of other conditions of the duodenum that mimic celiac disease. OBJECTIVE: - To review the normal histologic features of duodenal mucosa and describe the clinical and histologic findings in celiac disease and its mimics, listing the differentiating features of biopsies with villous atrophy and epithelial lymphocytosis. DATA SOURCES: - The study comprises a literature review of pertinent publications as of November 30, 2016. CONCLUSIONS: - Celiac disease is a common cause of abnormal duodenal histology. However, many of the histologic features found in the duodenal biopsy of patients with celiac disease are also present in other conditions that affect the small bowel. Diagnostic precision may be enhanced by obtaining a careful patient history and by ancillary laboratory testing, particularly for the presence of antitissue transglutaminase antibodies.

Development of CXCR3 antagonists. Part 2: Identification of 2-amino(4-piperidinyl)azoles as potent CXCR3 antagonists.

Development of a lead series of piperidinylurea CXCR3 antagonists has led to the identification of molecules with alternative linkages which retain good potency. A novel 5-(piperidin-4-yl)amino-1,2,4-thiadiazole derivative was found to have satisfactory in vitro metabolic stability and to be orally bioavailable in mice, giving high plasma concentrations and a half life of 5.4h.

Expression of integrin-linked kinase is not a useful prognostic marker in resected hepatocellular cancer.

BACKGROUND: Hepatocellular cancer (HCC) is one of the most common malignancies worldwide, and is known to be associated with a poor prognosis. Unfortunately there are no available reliable markers of prognosis. The aim of this study was to determine whether integrin-linked kinase (ILK) expression correlates with post-resection survival from HCC. PATIENTS AND METHODS: A tissue microarray was constructed using HCC samples, and immunohistochemical analysis for ILK was then carried out and scored by three independent observers. Clinical chart review was performed to determine survival parameters. RESULTS: Of the 52 cases of HCC, 22 cases were associated with hepatitis B (HBV), 18 with hepatitis C (HCV), 2 with HBV and HCV co-infection; 81% of all patients were male and 19% female. Western immunoblotting showed a highly significant correlation between levels of expression of ILK and ser473-PKBphosphorylation, both in control and tumor sections (Spearman rank correlation, r=0.8155, p=0.0004), however, there was no direct correlation between the levels of expression of ILK with patient survival (log-rank test, p= 0.864). CONCLUSION: ILK expression does not appear to have a role in predicting outcome in patients with resected HCC.

Malignant Colorectal Polyps; Pathological Consideration (A review).

BACKGROUND: Routine screening colonoscopy is on the rise and pathologists have to deal with the ever larger numbers of excised colonic polyps. It is very important to optimize the patients' individual treatment and further surveillance. Pathologists play a critical role in management, as most of the clinical decisions concerning colonic polyp management are based on pathologic findings. One of the most important clinical issues in colonic adenomas is the diagnosis of malignancy and reporting its different aspects by the pathologist. The histologic type and the extent of carcinoma within a malignant polyp have considerable impact on the decisions of gastroenterologists and surgeons for further management. Therefore, the most recent literature regarding the diagnosis and reporting of the different features of malignant polyps was reviewed. DATA ACQUISITION: There is growing literature regarding the different pathologic features and reporting of malignant colonic polyps, and in this review, published articles that are listed on Google Scholar and Pub Med are discussed. CONCLUSION: Diagnosis of malignant colon polyp requires the presence of tumor cells that are penetrating beyond the muscular mucosa into submucosa (pT1). As well as establishing a diagnosis of malignant polyp, it is very important to report the size of the invasive component, the presence or absence of lymphovascular invasion, the degree of tumor differentiation and the distance of the carcinoma from the line of resection. Other important features that may be reported include: the presence or absence of tumor budding, the depth of tumor cell penetration into the submucosa, and results of immunohistochemistry for mismatch repair proteins and BRAF.

Handling and Pathology Reporting of Gastrointestinal Endoscopic Mucosal Resection.

Endoscopic mucosal resection (EMR) is a non-invasive alternative to surgery that is now frequently used for resection of early lesions in both upper and lower parts of the gastrointestinal (GI) tract. One of the main advantages of these techniques is providing tissue for histopathological examination. Pathological examination of endoscopically resected specimens of GI tract is a crucial component of these procedures and is useful for prediction of both the risk of metastasis and lymph node involvement. As the first step, it is very important for the pathologist to handle the EMR gross specimen in the correct way: it should be oriented, and then the margins should be labeled and inked accurately before fixation. In the second step, the EMR pathological report should include all the detailed information about the diagnosis, grading, depth of invasion (mucosa only or submucosal involvement), status of the margins, and the presence or absence of lymphovascular invasion. The current literature (PubMed and Google Scholar) was searched for the words "endoscopic mucosal resection" to find all relevant publications about this technique with emphasis on the pathologist responsibilities.

Multidisciplinary management of ruptured hepatocellular carcinoma.

Spontaneous rupture of hepatocellular carcinoma (HCC) is a dramatic presentation of the disease. Most published studies are from Asian centers, and North American experience is limited. This study was undertaken to review the experience of ruptured HCC at a North American multidisciplinary unit. Thirty patients presenting with ruptured HCC at a tertiary care center from 1985 to 2004 were studied retrospectively and analyzed according to the demographics, clinical presentation, tumor characteristics, treatment, and outcome in four treatment groups: emergency resection, delayed resection (resection after angiographic embolization), transcatheter arterial embolization (TAE), and conservative management. Ten, 10, 7, and 3 patients underwent emergency resection, delayed resection, TAE, and conservative treatment, respectively. The mean age of all patients was 57 years, and the mean Child-Turcotte-Pugh score was 7 +/- 2. Cirrhosis was present in 57% of the patients. Seventy percent of tumors were greater than 5 cm in diameter, and 68% of patients had multiple tumors. There was a trend toward higher 30-day mortality in the emergency resection group than in the delayed resection group. One-year survival was significantly better in the delayed resection group. In selected patients, the multidisciplinary approach of angiographic embolization and delayed resection affords better short-term survival than emergency resection.

Immunophenotyping of ampullary carcinomata allows for stratification of treatment specific subgroups.

BACKGROUND: Ampullary carcinomata (AC) can be separated into intestinal (IT) or pancreatobiliary (PB) subtypes. Although morphological, immunohistochemical and molecular differentiation of IT and PB have been well documented; the prognostic significance of histological subtype and whether patients with either subtype benefit from differential chemotherapeutic regimens remains unclear. METHODS: As part of a larger cohort study, patients who underwent resection for AC or pancreatic ductal adenocarcinoma (PDAC) were retrospectively identified. Clinicopathological covariates and outcome were obtained and MUC1, MUC2, CDX2 and CK20 were assessed with immunohistochemistry. RESULTS: Of 99 ACs, the resultant immunophenotypes indicated 48% and 22% were IT and PB, respectively. Thirty (30%) cases were quadruple negative (QN). Within the PDAC cohort (N = 257), the most prevalent immunophenotype was QN (53%). Subsequently, all QN ACs were classified as PB immunohistochemically yielding 47.5% and 52.5% classified as IT and PB, respectively. Involved regional lymph nodes and elevated T-stage were significantly associated with PB compared with IT AC (p = 0.0032 and 0.0396, respectively). Progression-free survival revealed inferior survival for PB versus IT AC (p = 0.0156). CONCLUSIONS: AC can be classified into prognostic groups with unique clinicopathological characteristics using immunohistochemistry. Immunophenotypical similarity of PB and PDAC suggests that treatment regimens similar to those used in PDAC should be explored.

A Therapeutic Uricase with Reduced Immunogenicity Risk and Improved Development Properties.

Humans and higher primates are unique in that they lack uricase, the enzyme capable of oxidizing uric acid. As a consequence of this enzyme deficiency, humans have high serum uric acid levels. In some people, uric acid levels rise above the solubility limit resulting in crystallization in joints, acute inflammation in response to those crystals causes severe pain; a condition known as gout. Treatment for severe gout includes injection of non-human uricase to reduce serum uric acid levels. Krystexxa® is a hyper-PEGylated pig-baboon chimeric uricase indicated for chronic refractory gout that induces an immunogenic response in 91% of treated patients, including infusion reactions (26%) and anaphylaxis (6.5%). These properties limit its use and effectiveness. An innovative approach has been used to develop a therapeutic uricase with improved properties such as: soluble expression, neutral pH solubility, high E. coli expression level, thermal stability, and excellent activity. More than 200 diverse uricase sequences were aligned to guide protein engineering and reduce putative sequence liabilities. A single uricase lead candidate was identified, which showed low potential for immunogenicity in >200 human donor samples selected to represent diverse HLA haplotypes. Cysteines were engineered into the lead sequence for site specific PEGylation and studies demonstrated >95% PEGylation efficiency. PEGylated uricase retains enzymatic activity in vitro at neutral pH, in human serum and in vivo (rats and canines) and has an extended half-life. In canines, an 85% reduction in serum uric acid levels was observed with a single subcutaneous injection. This PEGylated, non-immunogenic uricase has the potential to provide meaningful benefits to patients with gout.

Primary peritoneal ependymoma.

Extra-axial ependymomas are exceedingly rare neuroectodermal tumors that arise outside the central nervous system. The majority behave in a benign clinical fashion. In this case, an elderly woman developed an intraperitoneal ependymoma that after surgical excision recurred twice over a period of twenty four years. At each presentation, the tumor demonstrated identical histologic appearances with prominent rosettes as well as perivascular pseudorosettes. Immunohistochemistry showed strong positivity for glial fibrilary acidic protein, estrogen receptors, CAM 5.2 and CD99 with weak staining for pankeratin. Staining was negative for epithelial membrane antigen (EMA) and S-100. Ultrastructurally, the neoplasm showed neuroectodermal features, including filamentous cytoplasm and abundant intercellular bridges. The patient had no lesions in the central nervous system or the para-spinal region, suggesting that this tumor arose spontaneously within the abdominal cavity.

Tumor budding is an independent adverse prognostic factor in pancreatic ductal adenocarcinoma.

Tumor budding is a well-established adverse prognostic factor in colorectal cancer. However, the significance and diagnostic reproducibility of budding in pancreatic carcinoma requires further study. We aimed to assess the prognostic significance of tumor budding in pancreatic ductal adenocarcinoma, determine its relationship with other clinicopathologic features, and assess interobserver variability in its diagnosis. Tumor budding was assessed in 192 archival cases of pancreatic ductal adenocarcinoma using hematoxylin and eosin (H&E) sections; tumor buds were defined as single cells or nonglandular clusters composed of <5 cells. The presence of budding was determined through assessment of all tumor-containing slides, and associations with clinicopathologic features and outcomes were analyzed. Six gastrointestinal pathologists participated in an interobserver variability study of 120 images of consecutive tumor slides stained with H&E and cytokeratin. Budding was present in 168 of 192 cases and was associated with decreased overall survival (P=0.001). On multivariable analysis, tumor budding was prognostically significantly independent of stage, grade, tumor size, nodal status, lymphovascular invasion, and perineural invasion. There was substantial agreement among pathologists in assessing the presence of tumor budding using both H&E (K=0.63) and cytokeratin (K=0.63) stains. The presence of tumor budding is an independent adverse prognostic factor in pancreatic ductal carcinoma. The assessment of budding with H&E is reliable and could be used to better risk stratify patients with pancreatic ductal adenocarcinoma.

Regression of cirrhosis associated with hepatitis B e (HBe) antigen-negative chronic hepatitis B infection with prolonged lamivudine therapy.

In theory, hepatic fibrosis should be a dynamic process with the potential for remodelling after the injury-provoking stimulus has been removed. Clinically, there has been an accumulation of a small number of cases, including hepatitis B e (HBe) antigen-positive chronic hepatitis B infection, in which cirrhosis regressed after successful treatment. We report a 42-year-old HBe antigen-negative Chinese man with detectable serum hepatitis B virus DNA and histologically established cirrhosis (Ludwig score 4) who, after 4 years of successful lamivudine therapy, was found to have regression of cirrhosis on repeat liver biopsy. The repeat biopsy revealed normal liver architecture with fibrosis confined to the portal tracts and short fibrosis septae extending into the lobule without bridging (Ludwig score 1-2). Although cirrhosis may take many years to develop, our experience suggests that successful treatment may reverse the process within a relatively short time.