Comparison of the utility of Cocaine- and Amphetamine-Regulated Transcript (CART), chromogranin A, and chromogranin B in neuroendocrine tumor diagnosis and assessment of disease progression

CONTEXT

Prognosis in patients with neuroendocrine tumors (NETs) is often poor, frequently reflecting delayed diagnosis. Hence, accurate and practical NET markers are needed. Cocaine- and amphetamine-regulated transcript (CART) peptide is a potential novel NET marker.

DESIGN AND PARTICIPANTS

Circulating levels of CART peptide and the established NET markers chromogranin A (CgA) and chromogranin B (CgB) were measured using RIA in 353 patients with NET (normal renal function) and in controls. Clinical data were collected retrospectively.

MAIN OUTCOME MEASURE(S)

The comparative and combined utility of CART, CgA, and CgB for diagnosis and assessment of disease progression was measured in different NET subtypes.

RESULTS

CgA and CgB in combination improved diagnostic accuracy in patients with gut NETs, nongastroenteropancreatic NETs, and NETs with an unknown primary origin compared with each biomarker alone. Measuring CART did not further improve diagnosis in these NET subtypes. For pancreatic NETs, CgB was superior to CgA and CART in detecting stable disease (P < .007), whereas CgA and CART in combination were most effective in identifying progressive disease. In phaeochromocytomas/paragangliomas (PCC/PGL), CART was the most useful biomarker for identifying stable (P < .001) and progressive (P = .001) disease. Consistent with this, plasma CART decreased following PCC/PGL tumor resection, remaining low in all patients in remission, but increasing in those with progressive disease.

CONCLUSIONS

CART is a useful marker for identifying progressive pancreatic NETs. CART is superior to CgA and CgB in detecting stable and progressive PCC/PGLs, and may have a role as a surveillance marker for PCC/PGL patients.

Beery-Buktenica Developmental Test of Visual-Motor Integration (Beery-VMI): lessons from exploration of cultural variations in visual-motor integration performance of preschoolers

BACKGROUND

Visual-motor integration (VMI) is important in children's development because it is associated with the performance of many functional skills. Deficits in VMI have been linked to difficulties in academic performance and functional tasks. Clinical assessment experience of occupational therapists in Singapore suggested that there is a potential difference between the VMI performance of Singaporean and American children. Cross-cultural studies also implied that culture has an influence on a child's VMI performance, as it shapes the activities that a child participates in. The purpose of this study was to (1) explore if there was a difference between the VMI performance of Singaporean and American preschoolers, and (2) determine if there were ethnic differences in the VMI performance of Singaporean preschoolers.

METHODS

The Beery-VMI, which was standardized in America, is commonly used by occupational therapists in Singapore to assess the VMI ability of children. We administered the Beery-VMI (fifth edition) full form test (excluding the supplemental tests) to 385 preschoolers (mean age = 63.3 months) from randomly selected schools in Singapore. We compared the scores of Singaporean preschoolers with those of the American standardization norms using the one-sample t-test. Scores of different ethnic groups among the Singapore population were also compared using a one-way anova, followed by the Bonferroni post-hoc test.

RESULTS

Singaporean preschoolers and the standardization sample of American children performed significantly differently in all age groups (P < 0.05). Among the Singapore population, the scores were also significantly different (P < 0.05) between the (i) Chinese and Malay and (ii) Chinese and Indians ethnic groups.

CONCLUSION

Preschoolers from different cultural and ethnic groups had different VMI performance. Certain cultural beliefs and practices may affect VMI performance. Clinicians should exercise caution when using an assessment in communities and cultures outside the ones on which it was standardized.

Alteration of regulatory T cells in type 1 diabetes mellitus: a comprehensive review

Type 1 diabetes mellitus (T1DM) is a T cell-mediated autoimmune disease characterized by the destruction of pancreatic β cells. Numerous studies have demonstrated the key role of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) in the development of T1DM. However, the changes in Treg expression and function as well as the regulation of these activities are not clearly elucidated. Most studies on the role of Tregs in T1DM were performed on peripheral blood rather than pancreas or pancreatic lymph nodes. Tissue-based studies are more difficult to perform, and there is a lack of histological data to support the role of Tregs in T1DM. In spite of this, strategies to increase Treg cell number and/or function have been viewed as potential therapeutic approaches in treating T1DM, and several clinical trials using these strategies have already emerged. Notably, many trials fail to demonstrate clinical response even when Treg treatment successfully boosts Tregs. In view of this, whether a failure of Tregs does exist and contribute to the development of T1DM and whether more Tregs would be clinically beneficial to patients should be carefully taken into consideration before applying Tregs as treatments in T1DM.

Abstract 1212: Studying cancer drug resistance in patient derived xenograft tumor models

Anti-cancer drugs, either targeted therapies or cytotoxic chemotherapies, have proven to be effective in treating certain cancer patients. However, in most cases, tumors recur and become resistant to the treatment after a period of time. There are urgent needs to understand the underlying drug resistance mechanisms, to discover drug resistance targets and drug resistance biomarkers and to develop new therapies or combination therapies to tackle this widely occurring clinical problem. Currently the main approaches to study cancer drug resistance include analyzing clinical samples and developing drug resistance models in vitro. Numerous potential resistance mechanisms have been revealed. However, validation of these findings in a clinical-like setting and to test therapies in preclinical studies requires in vivo tumor models of drug resistance.

At GenenDesign, we have developed cancer drug resistance PDX tumor models through short term drug testing or long term treatment of xenograft tumor mice. Cancer drugs investigated in our studies include major classes of targeted therapeutic modalities such as Her2 inhibitors, EGFR inhibitors, FGFR inhibitors and cMet/ALK inhibitors, as well as several standard of care (SoC) chemotherapies. From these studies, we have identified de novo resistance models, acquired resistance models and reversible resistance models in multiple cancer types including lung cancer and gastric cancer.

In analyzing more than a dozen of Her2 positive but Herceptin resistance PDX models, we have uncovered molecular abnormalities such as Pten deletion, PI3K mutation, amplification of EGFR, cMet and cyclin E, which have been reported previously to be associated with Herceptin resistance in early studies. Studies are on-going to test whether combination therapies will be effective in overcoming Herceptin resistance.

In drug response profiling of our PDX models, we also found wide spread phenotypical and functional heterogeneity in individual tumors. The heterogeneity within each tumor, in some cases, contributed to evolving of drug resistance from initially responsive tumors.

Citation Format: Tengfei Yu, Ying Yan, Wei Du, Yuefei Yang, Tingting Tan, Xuqin Yang, Jiali Gu, Liang Hua, Xin K. Ye, Zhenyu Gu. Studying cancer drug resistance in patient derived xenograft tumor models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1212. doi:10.1158/1538-7445.AM2014-1212

A novel aptamer-based competition strategy for ultrasensitive electrochemical detection of leukemia cells

A robust, nanobiotechnology-based electrochemical cytosensing platform for the detection of acute leukemia cells was developed with high sensitivity, selectivity, acceptable rapidity and excellent extensibility. It utilized the competitive binding of cell-specific aptamers to acute leukemia cells and subsequent voltammetric quantification of the metal signature. Greatly enhanced sensitivity was achieved with dual signal amplification by using Fe3O4 magnetic nanoparticles (MNPs) as carriers to load a large amount of gold nanoparticles (AuNPs) and AuNP-catalyzed silver deposition. The proposed competitive cytosensor showed high sensitivity with a detection limit down to 10 cells. This simple and low-cost electrochemical cytosensing approach offers great promise to extend its application to early detection of human leukemia and possibly to other cancer cells.

Design of embedded-hybrid antimicrobial peptides with enhanced cell selectivity and anti-biofilm activity

Antimicrobial peptides have attracted considerable attention because of their broad-spectrum antimicrobial activity and their low prognostic to induce antibiotic resistance which is the most common source of failure in bacterial infection treatment along with biofilms. The method to design hybrid peptide integrating different functional domains of peptides has many advantages. In this study, we designed an embedded-hybrid peptide R-FV-I16 by replacing a functional defective sequence RR7 with the anti-biofilm sequence FV7 embedded in the middle position of peptide RI16. The results demonstrated that the synthetic hybrid the peptide R-FV-I16 had potent antimicrobial activity over a wide range of Gram-negative and Gram-positive bacteria, as well as anti-biofilm activity. More importantly, R-FV-I16 showed lower hemolytic activity and cytotoxicity. Fluorescent assays demonstrated that R-FV-I16 depolarized the outer and the inner bacterial membranes, while scanning electron microscopy and transmission electron microscopy further indicated that this peptide killed bacterial cells by disrupting the cell membrane, thereby damaging membrane integrity. Results from SEM also provided evidence that R-FV-I16 inherited anti-biofilm activity from the functional peptide sequence FV7. Embedded-hybrid peptides could provide a new pattern for combining different functional domains and showing an effective avenue to screen for novel antimicrobial agents.

A phase I study of temsirolimus and bryostatin-1 in patients with metastatic renal cell carcinoma and soft tissue sarcoma

BACKGROUND

Temsirolimus, an inhibitor of mammalian target of rapamycin (mTOR) complex 1, is approved for the treatment of metastatic renal cell carcinoma (RCC). Bryostatin-1 inhibits protein kinase C, a downstream effector of mTOR complex 2. We observed antitumor effects with the combination of temsirolimus and bryostatin-1 in RCC cell lines. METHODS. Four cohorts of patients received weekly bryostatin-1 (20 μg/m²) with temsirolimus (10, 15, 25, or 37.5 mg) in 28-day cycles.

RESULTS

Thirty patients received a total of 138 cycles across four dose levels. Twenty-five patients had RCC (17 clear cell, 7 papillary, and 1 unclassified). Two sarcoma patients with prior cytotoxic therapy experienced dose-limiting toxicity at 15 mg of temsirolimus (grade 3 neutropenia and grade 3 hypophosphatemia). Subsequently, patients with prior cytotoxic therapy were excluded. Two additional dose-limiting toxicities were noted with 37.5 mg of temsirolimus (grade 3 neutropenia and grade 3 creatinine elevation). Consequently, the maximum tolerated dose was defined as temsirolimus at 25 mg and bryostatin-1 at 20 μg/m² every 28 days. Of the 25 RCC patients, 3 patients had partial responses that lasted for 14 months, 28 months, and ≥ 80 months, respectively. Partial responses were seen in both clear cell and papillary histology.

CONCLUSION

This combination of 37.5 mg of temsirolimus with 20 μg/m² of bryostatin-1 was reasonably safe and well tolerated. Durable responses were observed in 3 of 25 patients with RCC.

Multiplex acute leukemia cytosensing using multifunctional hybrid electrochemical nanoprobes at a hierarchically nanoarchitectured electrode interface

We have developed a robust, nanobiotechnology-based electrochemical cytosensing approach with high sensitivity, selectivity, and reproducibility toward the simultaneous multiplex detection and classification of both acute myeloid leukemia and acute lymphocytic leukemia cells. The construction of the electrochemical cytosensor involves the hierarchical assembly of dual aptamer-functionalized, multilayered graphene-Au nanoparticle electrode interface and the utilization of hybrid electrochemical nanoprobes co-functionalized with redox tags, horseradish peroxidase, and cell-targeting nucleic acid aptamers. The hybrid nanoprobes are multifunctional, capable of specifically targeting the cells of interest, amplifying the electrochemical signals, and generating distinguishable signals for multiplex cytosensing. The as-assembled electrode interface not only greatly facilitates the interfacial electron transfer process due to its high conductivity and surface area but also exhibits excellent biocompatibility and specificity for cell recognition and adhesion. A superstructured sandwich-type sensor geometry is adopted for electrochemical cytosensing, with the cells of interest sandwiched between the nanoprobes and the electrode interface. Such an electrochemical sensing strategy allows for ultrasensitive, multiplex acute leukemia cytosensing with a detection limit as low as ~350 cells per mL and a wide linear response range from 5 × 10(2) to 1 × 10(7) cells per mL for HL-60 and CEM cells, with minimal cross-reactivity and interference from non-targeting cells. This electrochemical cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection and classification of human acute leukemia and may be readily expanded to multiplex cytosensing of other cancer cells.

Characterization of plasma cytokines in an infant population cohort of challenge-proven food allergy

BACKGROUND

Sensitization to food allergens indicates the production of food-specific IgE; however, sensitization is not a definite indicator of allergic reaction upon ingestion (N Engl J Med, 344, 2001, 30: J Allergy Clin Immunol, 120, 2007, 491). Currently, food challenge is the best approach to identify the presence or absence of allergy. While 95% positive predictive values (PPVs) thresholds for sIgE can assist with identifying increased likelihood of allergy among those who are sensitized, there are no specific biological markers that differentiate between allergic and sensitized individuals.

OBJECTIVES

To determine whether plasma serum cytokine profiles predict (i) sensitization to peanut and egg and (ii) food allergy among sensitized infants.

METHODS

Peanut-sensitized (PT) and egg-sensitized 14-month-old infants and nonsensitized controls enrolled in HealthNuts, a population-based study of food allergy, underwent an oral food challenge (OFC). Blood was collected within 1 h after OFC. Serum levels of Th1, Th2 and regulatory cytokines were determined in allergic (n = 79), sensitized (n = 40) and nonsensitized, nonallergic (n = 37) infants by multiplex assay.

RESULTS

Food-sensitized infants had significantly higher plasma IL-4, IL-13, IL-12p70 and lower IL-10 levels compared to nonsensitized infants. IL-10 and IL-6 levels were significantly higher in sensitized compared with allergic infants. Egg-allergic infants had significantly higher IL-13 and IL-12p70 levels compared to peanut-allergic (PA) infants.

CONCLUSION

Levels of Th2-related cytokines in plasma are higher in food-sensitized infants, irrespective of clinical food allergy status. In contrast, IL-10 levels appear to predict food allergy among sensitized infants. Differences in IL-13 and IL-12p70 between egg- and peanut-allergic infants could help explain the different resolution rates of the allergies.

Ultrasensitive dual-channel detection of matrix metalloproteinase-2 in human serum using gold-quantum dot core-satellite nanoprobes

We have developed a robust enzymatic peptide cleavage-based assay for the ultrasensitive dual-channel detection of matrix metalloproteinase-2 (MMP-2) in human serum using gold-quantum dot (Au-QD) core-satellite nanoprobes.

Changes of intestinal tight junctions in rat ileums after partial hepatectomy

BACKGROUND

Increased intestinal permeability and bacterial translocation have been observed after partial hepatectomy (PH).

METHODS

Rats (n = 40) were randomly divided into four groups: control; PH 1d, PH 3d and PH 5d. PH animals underwent two-thirds partial hepatectomy before sacrifice at 1, 3, or 5 days thereafter. The intestinal tight junction (TJ) morphology was observed by transmission electron microscopy. Distribution of TJ protein occludin in lipid raft microdomains was examined using Western blot analysis.

RESULTS

Intestinal TJ structures revealed significant changes at 1 day after PH that had partly recovered by 5 days. During this period, occludin protein decreased significantly in lipid raft microdomains, increasing partially by 5 days.

CONCLUSION

PH induced disruption of TJ structures in rat ilea, which was associated with redistribution of occludin protein in lipid raft microdomains.