Prediction of cancer recurrence based on compact graphs of whole slide images

Cancer recurrence is one of the primary causes of patient mortality following treatment, indicating increased aggressiveness of cancer cells and difficulties in achieving a cure. A critical step to improve patients' survival is accurately predicting recurrence status and giving appropriate treatment. Whole Slide Images (WSIs) are a common type of image data in the field of digital pathology, containing high-resolution tissue information. Furthermore, WSIs of primary tumors contain microenvironmental information directly associated with the growth of tumor cells. To effectively utilize this microenvironmental information. Firstly, we represented microenvironmental features of histopathological images as compact graphs. Secondly, this work aims to develop an enhanced lightweight graph neural network called the Adaptive Graph Clustering Network (AGCNet) for predicting cancer recurrence. Experiments are conducted on three cancer datasets from The Cancer Genome Atlas (TCGA), and AGCNet achieved an accuracy of 81.81% in BLCA, 69.66% in PAAD, and 81.96% in STAD. These results indicated that AGCNet is an effective model for predicting cancer recurrence and is expected to be applied in clinical applications.

Knockdown of Long Noncoding RNA CCAT2 Suppresses Malignant Phenotype in Human Laryngeal Squamous Cell Carcinoma

This study aimed to explore the biological role and mechanism underlying the effects of colon cancer-associated transcript 2 (CCAT2), a long noncoding RNA (lncRNA) in human laryngeal squamous cell carcinoma (LSCC). CCAT2 expression levels in clinical LSCC samples and TU-212 cell line were evaluated by quantitative real-time PCR. The correlation of CCAT2 expression level with clinical-pathological characteristics of patients and their prognosis was analyzed. The functional role of CCAT2 in human LSCC was assessed by Cell Counting Kit-8, Transwell assay, flow cytometric analysis, and LSCC xenograft experiment in vivo. The expression of potential targeted proteins was detected by Western blotting and immunohistochemistry. We found that expression of CCAT2 was significantly elevated in LSCC tissues and TU-212 cells (p<0.05). Survival analysis showed that LSCC patients with high expression of CCAT2 had a shorter 5-year overall survival rate than those with low expression (p<0.05). In addition, CCAT2 silencing with short hairpin RNA significantly decreased the proliferative and invasive potential of TU-212 cells (p<0.05) and promoted their apoptosis. In Nude mice, CCAT2 knockdown suppressed the growth of tumor and decreased its volume and weight in comparison with the controls (p<0.05). In TU-212 cells, CCAT2 silencing with short hairpin RNA significantly down-regulated the expression of β-catenin and CDK8 (p<0.05). Thus, knockdown of CCAT2 suppresses proliferation and invasion of the cells and inhibits Wnt/β-catenin signaling pathway in LSCC, which indicates novel therapeutic targets and prognostic indicators in patients with LSCC.

Passion fruit peel and its zymolyte enhance gut function in Sanhuang broilers by improving antioxidation and short-chain fatty acids and decreasing inflammatory cytokines

The passion fruit peel (PFP) is the by-product of juice processing and is rich in phenolic compounds and dietary fibers. As the high ADF content in PFP (34.20%), we proceeded to treat PFP with cellulase. The ADF decreased to 16.70% after enzymatic processing, and we supposed that enzymolytic passion fruit peel (EPF) should have a greater growth performance than PFP to broilers. Two trials were conducted to evaluate the effects of dietary PFP or EPF supplementation on growth performance, serum biochemical indices, meat quality, and cecal short-chain fatty acids, microbiota, and metabolites in broilers. In Exp. 1, 180 1-day-old Sanhuang broilers (male, 36.17 ± 2.47 g) were randomly allocated into 3 treatments, with 6 replicates in each treatment. The 3 experimental diets included 1 basal diet (control) and 2 PFP-added diets supplemented with 1 and 2% PFP, respectively. The trial lasted for 42 d. In Exp. 2, 144 Sanhuang broilers (male, 112-day-old, 1.62 ± 0.21 kg) were randomly allocated to 3 treatments. Each treatment was distributed among 6 pens, and each pen contained 8 broilers. The 3 treatment diets included: a control diet, a positive control diet supplementing 75 mg/kg chlortetracycline, and the experimental diet supplementing 3% EPF. The trial lasted for 56 d. Results showed that dietary 1 and 2% PFP addition did not affect growth performance in Exp. 1, and the 3% EPF supplementation had a negative effect on ADFI (P < 0.05) in Exp. 2. A decreased serum triglyceride (P < 0.05) in broilers was observed in Exp. 1. Broilers fed EPF had a higher glutathione peroxidase (GSH-Px) (P < 0.05), and lower levels of tumor necrosis factor-α (TNF-α) (P < 0.05) and glucose (P < 0.05) in Exp. 2. We also found that broilers from PFP or EPF-treated treatments had an increased butyrate content and higher microbial diversity in the cecum. The effects of antioxidation, anti-inflammatory function, and elevated SCFAs were confirmed after the microbe and untargeted metabolomic analysis. Dietary EPF supplementation significantly increased the SCFA-generating bacteria, anti-inflammatory-related bacteria, the antioxidant-related and anti-inflammatory-related metabolites. Moreover, dietary 3% EPF addition positively affects the biosynthesis of phenylpropanoids, which strongly correlate with the antioxidant and anti-inflammatory properties. In conclusion, the proper addition level did not affect the growth performance, and the PFP and EPF could improve the antioxidation state, anti-inflammatory activity, and intestinal functions of Sanhuang broilers to some extent.

Pancreatic cancer prognosis is predicted by an ATAC-array technology for assessing chromatin accessibility

Unlike other malignancies, therapeutic options in pancreatic ductal adenocarcinoma (PDAC) are largely limited to cytotoxic chemotherapy without the benefit of molecular markers predicting response. Here we report tumor-cell-intrinsic chromatin accessibility patterns of treatment-naïve surgically resected PDAC tumors that were subsequently treated with (Gem)/Abraxane adjuvant chemotherapy. By ATAC-seq analyses of EpCAM+ PDAC malignant epithelial cells sorted from 54 freshly resected human tumors, we show here the discovery of a signature of 1092 chromatin loci displaying differential accessibility between patients with disease free survival (DFS) < 1 year and patients with DFS > 1 year. Analyzing transcription factor (TF) binding motifs within these loci, we identify two TFs (ZKSCAN1 and HNF1b) displaying differential nuclear localization between patients with short vs. long DFS. We further develop a chromatin accessibility microarray methodology termed "ATAC-array", an easy-to-use platform obviating the time and cost of next generation sequencing. Applying this methodology to the original ATAC-seq libraries as well as independent libraries generated from patient-derived organoids, we validate ATAC-array technology in both the original ATAC-seq cohort as well as in an independent validation cohort. We conclude that PDAC prognosis can be predicted by ATAC-array, which represents a low-cost, clinically feasible technology for assessing chromatin accessibility profiles.

Abstract P3-04-11: ER is required for mTORC1 inhibitor-induced feedback activation of PI3K/AKT in ER+ breast cancer cells and patients' tumors

The mTORC1 inhibitor everolimus (afinitor) is approved for the treatment of patients with advanced/metastatic ER+/HER2- breast cancer in combination with the steroidal aromatase inhibitor exemestane following progression on a non-steroidal aromatase inhibitor. The BOLERO-2 and TAMRAD studies demonstrated that combined everolimus/anti-estrogen therapy provided longer PFS compared to anti-estrogen alone. However, it has not been clarified whether continued treatment with an anti-estrogen backbone is beneficial in the setting of mTORC1 inhibition.

Upon activation by mTORC1, p70S6K phosphorylates the insulin-like growth factor-1 receptor (IGF-1R)/insulin receptor (InsR) effector IRS-1 to promote IRS-1 degradation, which in turn decreases activation of phosphatidylinositol 3-kinase (PI3K), AKT, and mTORC1. IGF1R, IRS1, and IRS2 are ER-inducible genes, and crosstalk between the ER and IGF-1R pathways has been described. We hypothesized that mTORC1 inhibition with everolimus will upregulate IGF-1R/InsR/IRS-1/2 signaling to activate PI3K/AKT and promote cancer cell survival, while combined inhibition of ER and mTORC1 will block PI3K/AKT activation by decreasing IGF-1R and IRS-1/2, providing rationale for combined targeting of ER and mTORC1.

In 3 ER+ breast cancer cell lines, everolimus treatment increased phospho-AKT levels. ER inhibition with fulvestrant suppressed the induction of P-AKT by everolimus. IGF-1R/InsR inhibition with OSI-906, and RNAi-mediated knockdown of IGF-1R, InsR, or IRS-1/2, decreased everolimus-induced P-AKT. Everolimus sensitized IGF-1R/InsR to IGF-1 that was suppressed by fulvestrant but enhanced by 17b-estradiol. Although fulvestrant decreased IGF-1R and InsR protein levels, phospho-receptor tyrosine kinase profiling showed that fulvestrant increased P-IGF-1R and P-InsR. Acting downstream of IGF-1R/InsR, fulvestrant prevented everolimus-induced PI3K/AKT activation by blocking binding between the p85 regulatory subunit of PI3K and IRS-1, possibly by decreasing IRS-1/2 levels. In summary, everolimus-induced activation of PI3K/AKT requires IGF-1R/InsR/IRS-1/2 signaling facilitated by ER. Combined treatment with fulvestrant and everolimus synergistically inhibited growth in 4 ER+ cell lines.

To determine whether ER promotes PI3K/AKT activation induced by mTORC1 inhibition in patients' tumors without exposing patients to everolimus, we analyzed live tumor tissues from post-menopausal patients with ER+/HER2- breast cancer treated +/- letrozole for 10-21 d before surgical tumor resection. Tumor cores (1 mm diameter) were used for ex vivo culture in DMEM +/- everolimus +/- OSI-906 for 1 h, and lysates were analyzed by immunoblot. Everolimus significantly increased P-AKT in tumors from untreated patients (n=10). OSI-906 did not affect P-AKT, but OSI-906 suppressed everolimus-induced P-AKT. In tumors from letrozole-treated patients (n=7), neither everolimus nor OSI-906 affected P-AKT. These data collectively suggest that ER activation is required for activation of PI3K/AKT induced by mTORC1 inhibition, and provide rationale for therapeutic combinations of anti-estrogens and mTORC1 inhibitors.

Citation Format: Yang W, Chen VS, Schwartz GN, Marotti JD, Rosenkranz KM, Gui J, Miller TW. ER is required for mTORC1 inhibitor-induced feedback activation of PI3K/AKT in ER+ breast cancer cells and patients' tumors [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-11.

Abstract P4-09-20: Plasma DNA as a surrogate for tumor biopsy to identify genetic alterations in patients with metastatic breast cancer

Precision medicine requires that a patient's tumor be accurately genotyped to identify a potentially effective targeted therapy. However, genotyping a tumor in patients with oligometastatic disease is complicated by the potential for intratumor and intertumor heterogeneity, and the requirement for sufficient tumor tissue obtained by invasive biopsy for genetic profiling. We sought to determine whether circulating tumor DNA in plasma provides a surrogate for solid tumor biopsy, and captures the genetic heterogeneity of tumors in patients with metastatic breast cancer. We hypothesized that genetic mutations detected in plasma DNA are reflective of the genetic mutations present in all tumors within a patient.

Eight patients with advanced/metastatic breast cancer have thus far been enrolled in an ongoing clinical study (NCT01836640). Tumor specimens from two (n=4) or three (n=4) tumor sites and blood were obtained with one month. Blood was separated into plasma and buffy coat fractions. DNA extracted from tissue, buffy coat, and plasma samples was used for massively parallel DNA sequencing using the Ion Proton platform with a custom TargetSeq capture probe set covering all exons of 196 genes (4.1 Mb). All tumor and buffy coat samples, and plasma samples from three patients have thus far been analyzed. Tumor mutations were identified by comparison to buffy coat DNA sequences. We achieved sequencing coverage of ∼100-fold for tumor and buffy coat DNA samples, and ∼1,000-fold for plasma DNA samples. In Patient #1, we obtained 14 tumor nodules from a mastectomy specimen and used 3 nodules for DNA sequencing; Among the 73 point mutations detected in DNA from at least one tumor nodule, 29 mutations (40%) were detected in plasma DNA, and 10 mutations were found in plasma but not in tumors. In Patient #5, we analyzed bilateral breast tumors and a brain metastasis; among 151 mutations detected in at least one tumor, 80 (53%) were found in plasma, and an additional 18 mutations were found in plasma but not tumors; mutations specific to the brain tumor were less likely to be found in plasma; interestingly, the bilateral breast tumors showed genetic and histologic similarity, and so were likely derived from a single clone. Patient #6 had only one lung metastasis evaluable by DNA sequencing; 64/125 (51%) tumor-derived mutations were detected in plasma, and an additional 26 mutations were found in plasma but not the tumor.

Preliminary ResultsMutationsTumorPlasma (Plasma only)TotalPlasma concordance with tumorPlasma concordance with totalTumor concordance with totalPatient #17329 (10)8339.7%46.9%87.9%Patient #515180 (18)16952.9%57.9%89.3%Patient #612564 (26)15151.2%59.6%82.8%

These data suggest that, although challenging to get multiple biopsies for comparison, plasma is a promising surrogate for solid tumor biopsy to identify potentially targetable mutations. However, the ability of plasma DNA to genetically reflect all tumors in a patient with oligometastatic disease remains to be clarified through further analysis.

Citation Format: Chamberlin MD, Shee K, Varn FS, Bean JR, Marotti JD, Gui J, Gemery JM, Barth RJ, Rosenkranz KM, Tsapakos MJ, McNulty NJ, Cheng C, Miller TW. Plasma DNA as a surrogate for tumor biopsy to identify genetic alterations in patients with metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-20.

Vitamin D rescues dysfunction of fetal endothelial colony forming cells from individuals with gestational diabetes

INTRODUCTION

Gestational diabetes (GDM) is associated with long-term cardiovascular and metabolic diseases in offspring. However, the mechanisms are not well understood. We explored whether fetal exposure to a diabetic environment is associated with fetal endothelial progenitor cell dysfunction, and whether vitamin D can reverse the impairment.

METHODS

Nineteen women with uncomplicated pregnancies and 18 women with GDM were recruited before delivery. Time to first appearance of endothelial colony forming cell (ECFC) colonies and number of ECFC colonies formed from culture of cord peripheral blood mononuclear cells were determined. Angiogenesis-related functions of ECFCs in vitro were tested in the presence or absence of vitamin D.

RESULTS

Fetal ECFCs from GDM pregnancies formed fewer colonies in culture (P = 0.04) and displayed reduced proliferation (P = 0.02), migration (P = 0.04) and tubule formation (P = 0.03) compared to uncomplicated pregnancies. Fetal ECFCs exposed to hyperglycemia in vitro exhibited less migration (P < 0.05) and less tubule formation (P < 0.05) than normoglycemic control. Vitamin D significantly improved the dysfunction of fetal ECFCs from pregnancies complicated by GDM or after exposure of healthy ECFCs to hyperglycemia.

DISCUSSION

Fetal ECFCs from GDM pregnancies or ECFCs exposed to hyperglycemia in vitro exhibit reduced quantity and impaired angiogenesis-related functions. Vitamin D significantly rescues these functions. These findings may have implications for vascular function of infants exposed to a diabetic intrauterine environment.

Medaka piwi is essential for primordial germ cell migration

Piwi controls the number of primordial germ cells (PGCs) via protecting maternal mRNA from decay and adult germ stem cell division in Drosophila. In mouse and zebrafish, piwi controls maintenance and differentiation of adult germ stem cell during gametogenesis. Whether piwi plays a role in PGC development of vertebrates remains unsolved. We addressed this issue by using medaka (Oryzias latipes) as a vertebrate model. Molecular cloning, sequence comparison and analyses of genomic organization and chromosome synteny led to the identification in this fish of a single piwi gene, called Opiwi. By RT-PCR analyses and in situ hybridization, the Opiwi transcript is maternally supplied and becomes restricted to PGCs and the central nervous system (CNS). Opiwi knockdown did not prevent PGC formation even in the absence of any somatic structures but did significantly reduce the number of PGCs in vivo and in vitro and affect the distribution of PGCs in developing embryos. Surprisingly, depletion of zygotic Opiwi severely and specifically affected PGC migration. We conclude that Opiwi is required not only for determining the PGC number but also for controlling PGC migration. Our results demonstrate that piwi plays a generally conserved role in germ cell development from Drosophila to vertebrate and a specific role in PGC migration.

Gene-viro-therapy targeting liver cancer by a dual-regulated oncolytic adenoviral vector harboring IL-24 and TRAIL

Cancer-targeting gene-viro-therapy is a promising cancer therapeutic strategy that strengthens the antitumor effect of oncolytic viruses by expressing an inserted foreign antitumor gene. To achieve liver cancer targeting and to improve the safety of the ZD55 vector (a widely-used E1B55KD gene-deleted oncolytic adenoviral vector (OV), we previously constructed), we designed a novel OV named Ad·AFP·D55 that selectively replicates in hepatocellular carcinoma (HCC) cells by replacing the E1A promoter with the liver-cancer specific α-Fetoprotein (AFP) promoter based on the ZD55 vector. We found that the oncolytic adenoviruses Ad·AFP·D55-IL-24 and Ad·AFP·D55-TRAIL express tumor-suppressor gene interleukin-24 (IL-24) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), respectively, significantly suppressed the HCC cell growth in vitro by inducing apoptosis by the caspase-8 and mitochondria-dependent caspase-9 signaling pathways. Furthermore, the combined treatment of Ad·AFP·D55-IL-24 and Ad·AFP·D55-TRAIL showed strong antitumor effects in vivo by significantly inhibiting the tumor growth in HCC HuH-7 cell xenograft mice, and markedly increasing animal survival rate. Therefore, this novel HCC cell-targeting OV carrying tumor-suppressor genes may provide a promising approach for liver cancer gene therapy.

Extracellular proteases in renal cell carcinoma

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Background: Tumor growth and metastasis relies on extracellular matrix remodeling, which is primarily mediated by the matrix metalloproteinase (MMP) family of enzymes. Extracellular matrix metalloprotease inducer (EMMPRIN, E) is a glycoprotein also implicated in tumor progression and has been shown to function in concert with MMPs. MMPs and E are highly expressed on the surface of many malignant tumors, including renal cell carcinoma (RCC). We investigated whether MMPs and E represent molecular prognostic factors in RCC.

Methods: Protein expression was evaluated in 77 patients with immunohistochemical analysis of a tissue microarray (TMA) consisting of two tumor samples and an adjacent normal renal sample from each patient. Tumors represented on the TMA were clear cell (57), chromophobe (9), papillary (4), oncocytomas (3), clear cell with sarcomatoid differentiation (2), and metastatic (2). Protein expression scores were correlated with clinical outcomes to determine prognostic significance by univariate and multivariate analyses.

Results: Using univariate analysis of all RCC tumors, membranous E correlated with overall survival (OS), metastasis-free survival (MFS), size, stage and overall 5-yr survival. Cytoplasmic E correlated with OS, MFS, size, grade, stage and 5-yr survival. Membranous MT1-MMP correlated with MFS, and endothelial MMP-2 correlated with grade. In multivariate analysis, membranous E was an independent indicator of stage, whereas cytoplasmic E was an independent indicator for size, stage, grade and MFS. In the clear cell population, membranous MT1-MMP correlated with OS and MFS, and endothelial MMP-2 correlated with grade in univariate analysis. In multivariate analysis, membranous MT1-MMP was an independent indicator for MFS.

Conclusions: We identified EMMPRIN as an independent prognostic indicator for size, grade, stage, and MFS in RCC. While MT1-MMP and MMP-2 both significantly correlated with disease outcome in the clear cell RCC population, only MT1-MMP was an independent prognostic factor for MFS. We conclude that MMPs and E mediate important steps in RCC progression. Further investigation is warranted using larger datasets and a prospective study to determine the strength of the prognostic significance of these findings.

No significant financial relationships to disclose.

Correlations between clinical and physiological consequences of the novel mutation R878C in a highly conserved pore residue in the cardiac Na+ channel

Aim:

We compared the clinical and physiological consequences of the novel mutation R878C in a highly conserved pore residue in domain II (S5-S6) of human, hNa_v1.5, cardiac Na⁺ channels.

Methods:

Full clinical evaluation of pedigree members through three generations of a Chinese family combined with SCN5A sequencing from genomic DNA was compared with patch and voltage-clamp results from two independent expression systems.

Results:

The four mutation carriers showed bradycardia, and slowed sino-atrial, atrioventricular and intraventricular conduction. Two also showed sick sinus syndrome; two had ST elevation in leads V1 and V2. Unlike WT-hNa_v1.5, whole-cell patch-clamped HEK293 cells expressing R878C-hNa_v1.5 showed no detectable Na⁺ currents (i_Na), even with substitution of a similarly charged lysine residue. Voltage-clamped Xenopus oocytes injected with either 0.04 or 1.5 μg μL⁻¹ R878C-hNa_v1.5 cRNA similarly showed no i_Na, yet WT-hNa_v1.5 cRNA diluted to 0.0004–0.0008 ng μL⁻¹resulted in expression of detectable i_Na. i_Na was simply determined by the amount of injected WT-hNa_v1.5: doubling the dose of WT-hNa_v1.5 cRNA doubled i_Na. i_Na amplitudes and activation and inactivation characteristics were similar irrespective of whether WT-hNa_v1.5 cRNA was given alone or combined with equal doses of R878C-hNa_v1.5 cRNA therefore excluding dominant negative phenotypic effects. Na⁺ channel function in HEK293 cells transfected with R878C-hNa_v1.5 was not restored by exposure to mexiletine (200 μm) and lidocaine (100 μm). Fluorescence confocal microscopy using E3-Nav1.5 antibody demonstrated persistent membrane expression of both WT and R878C-hNa_v1.5. Modelling studies confirmed that such i_Na reductions reproduced the SSS phenotype.

Conclusion:

Clinical consequences of the novel R878C mutation correlate with results of physiological studies.

Threshold gradient descent method for censored data regression with applications in pharmacogenomics

An important area of research in pharmacogenomics is to relate high-dimensional genetic or genomic data to various clinical phenotypes of patients. Due to large variability in time to certain clinical event among patients, studying possibly censored survival phenotypes can be more informative than treating the phenotypes as categorical variables. In this paper, we develop a threshold gradient descent (TGD) method for the Cox model to select genes that are relevant to patients' survival and to build a predictive model for the risk of a future patient. The computational difficulty associated with the estimation in the high-dimensional and low-sample size settings can be efficiently solved by the gradient descent iterations. Results from application to real data set on predicting survival after chemotherapy for patients with diffuse large B-cell lymphoma demonstrate that the proposed method can be used for identifying important genes that are related to time to death due to cancer and for building a parsimonious model for predicting the survival of future patients. The TGD based Cox regression gives better predictive performance than the L2 penalized regression and can select more relevant genes than the L1 penalized regression.

Monte Carlo simulations of liquid spreading on a solid surface: effect of end-group functionality

The spreading of liquid droplets composed of molecules with or without reactive end groups over a solid surface has been studied using Monte Carlo simulations. For molecules without reactive end groups, a molecular layering in the spreading profiles is predicted, depending on the ratio of the magnitude of intermolecular interactions to thermal energy. As intermolecular interactions become smaller than thermal energy, the layered structure vanishes. For molecules with reactive end groups, interactions between end groups and between end groups and the surface complicate the situation. By assuming an end-to-end interaction between molecules and the pinning of end groups to the surface, a complex layered structure is obtained. Our simulation predicts spreading profiles that accurately describe the broad spectrum of data obtained from scanning microellipsometry for perfluoropolyalkylethers with and without reactive end groups.

Cocaine sensitization can accelerate the onset of peak cocaine behavioral effects

The development of sensitization to the behavioral effects of cocaine occurs with repeated intermittent usage. In the present study rats were given five daily i.p. injections of cocaine (10 mg/kg) immediately prior to placement in an open-field environment for 20 min to induce cocaine sensitization. Control groups received saline injections or cocaine injections (10 mg/kg) 30 min after testing in the home cage. One week later the animals were given a challenge test with 10 mg/kg cocaine. The animals that had received cocaine in the test environment exhibited a more rapid onset of cocaine-induced behavioral effects than either animals previously treated with saline or animals that had received cocaine in the home cage. In a second experiment, the same sensitization protocol was followed except that during the interval between the end of the cocaine/saline treatments and the challenge test, the animals were given six daily 20-min saline tests to assess the contribution of differential habituation and/or Pavlovian conditioning to the sensitization effect. Neither habituation or Pavlovian conditioning altered the more rapid onset of cocaine stimulant effects induced by repeated cocaine treatments. It is suggested that the faster onset of cocaine effects is another way in which cocaine sensitization contributes to cocaine abuse liability.

Effects of dizocilpine (MK-801) on motor activity and memory

The effects of MK-801 upon motor activity and memory were assessed in a novel use of open-field behavior testing. In this study, rats were treated with different doses of MK-801 (0.025, 0.05, 0.1 and 0.2 mg/kg) and given a brief 10-min exposure to an open-field in which locomotor activity and within-session habituation were measured. Doses of MK-801 < or =0.1 mg/kg had no effect upon locomotor activity or within-session habituation. MK-801 0.2 mg/kg produced a marked hyperlocomotion and completely prevented within-session habituation. One day later, the animals were tested for their retention of habituation to evaluate the effects of MK-801 on memory processes. In that animals treated with 0.2 mg/kg MK-801 failed to habituate to the novel environment under the influence of 0.2 mg/kg MK-801, it was not surprising that these animals were impaired on the retention test for the novel environment. Importantly, however, the 0.1 mg/kg MK-801 treatment, which did not affect locomotor activity or within-session habitation to the novel environment, severely interfered with retention of the novel environment. Additional experiments indicated that this result could not be accounted for by drug conditioning or drug state-dependent effects. Thus, the results indicated that MK-801 can produce profound effects upon motor activity and memory and that these two effects can be disassociated.

Cocaine conditioning and cocaine sensitization: what is the relationship?

With repeated cocaine use, cocaine conditioned behavior develops to associated stimuli, and in addition, sensitization can occur to the unconditioned stimulant effects of cocaine. To investigate the relationship between the conditioned and unconditioned behavioral effects of repeated cocaine use, two groups of rats (n = 7) were given five daily paired cocaine treatments (10 mg/kg i.p.) immediately before a 20-min placement in an open-field environment. Other groups received either saline before testing or cocaine unpaired which was administered 30 min after testing in the homecage. When tested in the open-field with saline for conditioned effects, the two cocaine paired groups selectively exhibited substantial and equivalent cocaine conditioned responses. One of these groups was subjected to an extinction procedure which was effective in eliminating the cocaine conditioned responses. Subsequently, all the rats which had received cocaine in the first phase of the experiment, paired and unpaired, along with a subset of saline animals were given a cocaine (10 mg/kg i.p.) challenge test. The paired cocaine animals exhibited an earlier onset of the cocaine induced behavioral response (sensitization) as compared with the saline and the unpaired cocaine animals. Critically, the sensitization effects were unaffected by extinction, and in addition, the conditioned response did not contribute to the sensitization effect. It is suggested that the cocaine drug response occludes the cocaine conditioned response. Subsequent to this sensitization test, the animals were retested for conditioning. In this test, the paired cocaine animals which had not been subjected to the extinction procedure still exhibited a conditioned cocaine response, whereas, the paired cocaine group subjected to extinction was indistinguishable from saline controls. Although the present results show that Pavlovian conditioned responses to exteroceptive contextual cues do not directly contribute to cocaine induced behavioral sensitization effects, the sensitization effects were context-specific, and therefore, were tied to associative processes. It is suggested that context specificity is mediated by a compound stimulus complex comprised of exteroceptive stimuli and interoceptive cocaine drug cues. Furthermore, these exteroceptive and interoceptive cues associated with cocaine effectively expedite the onset of cocaine effects, and thereby, facilitate the addictive potency of cocaine.

[Senility-preventing effect of erlingcankang decoction]

Experiments with Erlingcankang Decoction showed that when given to silk worms it could noticeably prolong the growth period of larvae and raise an average of 10-day survival of the male moths; when given to mice it could prolong their life; and when given to on old rats it could markedly raise the contents of SOD in the liver and red cells, lower the content of MAO-B in the brain, LF in the brain and adrenal gland and also LPO in the liver.

A simple and reliable method for the positive identification of pavlovian conditioned cocaine effects in open-field behavior

The identification of the Pavlovian conditioning of the behavioral effects of cocaine using open-field behavior is often confounded by the concurrent occurrence of behavioral habituation in control animals. Thus, differences in spontaneous activity between cocaine conditioned animals vs. control can be explained either by Pavlovian conditioning of the psychostimulant effects of cocaine or by anti-habituation effects of cocaine. In a series of experiments we demonstrate that location of the animal within the open-field permits a positive identification of cocaine conditioning independent from habituation factors. In three separate experiments, five daily paired 10 mg/kg cocaine treatments induced both increased locomotion as well as increased entries into the central zone in the open-field as compared with saline and cocaine unpaired control groups. Critically, in three experimental replications, animals which received the paired cocaine treatment exhibited statistically significant increases in central zone entries in non-drug tests for conditioning both with respect to the saline and cocaine unpaired groups as well as to pre-conditioning levels. In contrast, the spontaneous locomotor behavior in the cocaine paired group on the conditioning test did not reliably increase above pre-conditioning levels but rather was only increased when compared with the reduced habituated activity levels in the saline and cocaine unpaired groups. The conditioned increase in central zone entries induced by cocaine was equally robust at 4 and 9 days post-conditioning but yet could be extinguished with repeated non-cocaine exposures to the open-field environment.

Identification of a decapeptide with the binding reactivity for tumor-associated TAG72 antigen from a phage displayed library

Peptide ligands for tumor-associated TAG72 antigen were identified by screening a large, diverse decapeptide library expressed on the surface of filamentous phages. Fifty-eight clones of phages were selected from the eluates after the third round of biopanning and their DNA inserts were sequenced. A dominant decapeptide HYVSIELPDH (14/58) was found with the binding reactivity for TAG72 antigen in the TAG72-binding ELISA and Western dot blotting. It also showed a preferential binding to colonic adenocarcinomatous cells expressing the TAG72 antigen in the histochemical study. Therefore, this anti-TAG72 decapeptide may be useful in serving as the starting point with regard to further designing peptidomimetics for potential pharmaceuticals.

Selection of a peptide with affinity for the tumor-associated TAG72 antigen from a phage-displayed library

A hexapeptide phage library was used to select peptides with affinity for the tumor-associated TAG72 antigen. Twenty-one phage clones were selected after the third round of biopanning. Three phage clones with the same DNA insert of ARTLRF were found to bind more strongly to the TAG72 antigen than other phage clones and the wild-type phage. A synthetic decapeptide GAARTLRFGA with two conjunctive amino acid residues of the phage coat protein III on each side of the selected peptide was found to bind more strongly to the TAG72 antigen than to other antigens such as the mouse metallothionein. Furthermore, immunohistochemical studies revealed that this peptide displayed preferential binding to colonic adenocarcinomatous cells expressing the TAG72 antigen. Therefore, this anti-TAG72 peptide may be useful in serving as the starting point with regard to further designing peptidomimetics as potential pharmaceuticals.

In situ localization and chromosomal mapping of the AG1 (Dmp1) gene

Dentinogenesis is being used as a model for understanding the biomineralization process. The odontoblasts synthesize a structural matrix comprised of Type I collagen fibrils which define the basic architecture of the tissue. The odontoblasts also synthesize and deliver a number of dentin-specific acidic macromolecules into the extracellular compartment. These acidic macromolecules may be involved in regulating the ordered deposition of hydroxyapatite crystals within the matrix. AG1 is the first tooth-specific acidic macromolecule to have been cloned and sequenced. To identify which cells of the rat incisor pulp/odontoblast complex were responsible for synthesis of AG1, in situ hybridization was used. Digoxigenin labeled sense and anti-sense AG1 riboprobes were prepared. The AG1 mRNA was found to be expressed in the mature secretory odontoblasts. Neither pulp cells nor pre-odontoblasts showed any staining with the anti-sense probes. Chromosomal localization studies placed the AG1 gene on mouse chromosome 5q21, in tight linkage with Fgf5. AG1 has been renamed Dmp1 (dentin matrix protein 1) in accordance with present chromosomal nomenclature. Mouse 5q21 corresponds to the 4q21 locus in humans. This is the locus for the human tooth mineralization disorder dentinogenesis imperfecta Type II (DI-II). These data suggest that the Dmp1 gene is involved in mineralization and is a candidate gene for DI-II.