[Research progress in regional odontodysplasia]

Regional odontodysplasia (ROD) is a rare localized dental developmental anomaly. The typical clinical manifestations of ROD are abnormal tooth eruption, abnormal development of enamel and dentin. The radiographic characteristic is "ghost teeth". Its etiology still remains unknown. The care and treatment of a patient with ROD needs a multidisciplinary approach. And the treatment should be taken after the assessment of each individual case of ROD. This paper reviews the definition, etiology, epidemiological features, clinical manifestations, imaging features, dental microstructure and treatment strategies of ROD to provide reference for clinical diagnosis and treatment.

[Short-term prognostic predictive value of the neutrophil/lymphocyte ratio combined with prognostic nutritional index in hepatitis B virus-related acute-on-chronic liver failure]

Objective: To explore the prognostic predictive value of neutrophil/lymphocyte ratio (NLR) combined with prognostic nutritional index (PNI) in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). Methods: Clinical data from 149 HBV-ACLF patients admitted to the infectious diseases Department of the General Hospital of Ningxia Medical University were retrospectively analyzed. Demographic data of the enrolled patients and the initial clinical-related data after admission were collected. Patients were divided into survival (93 cases) and death groups (56 cases) according to their prognostic condition 90 days after discharge. Demographic and clinical differences were compared between the two groups data. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cutoff values for NLR and PNI in predicting the 90-day mortality rate of HBV-ACLF patients. The COX regression model was used to conduct univariate and multivariate analyses to investigate the correlation between NLR and PNI and the prognosis of HBV-ACLF patients. Kaplan-Meier survival analysis was used to explore the effects of NLR and PNI on the survival of HBV-ACLF patients. Results: The death group NLR was higher than that of the survival group, while the PNI was lower than that of the survival group, with a statistically significant difference. The area under the receiver operating characteristic curve (0.842, 95% CI: 0.779-0.906) showed patients with adverse prognosis assessed by NLR combined with PNI had a superior prognosis than that of the Model for End-Stage Liver Disease (MELD) and its combined serum sodium (MELD-Na) and Child-Turcotte-Pugh (CTP) scores. COX regression analysis showed that NLR≥3.03 and MELD score were independent risk factors affecting the prognosis of HBV-ACLF patients. PNI > 36.13 was a protective factor for evaluating the prognosis of HBV-ACLF patients. Conclusion: NLR combined with PNI can enhance the prognostic predictive value of HBV-ACLF.

Regulations of Tumor Microenvironment by Prostaglandins

Prostaglandins, the bioactive lipids generated from the metabolism of arachidonic acid through cyclooxygenases, have potent effects on many constituents of tumor microenvironments. In this review, we will describe the formation and activities of prostaglandins in the context of the tumor microenvironment. We will discuss the regulation of cancer-associated fibroblasts and immune constituents by prostaglandins and their roles in immune escapes during tumor progression. The review concludes with future perspectives on improving the efficacy of immunotherapy through repurposing non-steroid anti-inflammatory drugs and other prostaglandin modulators.

[The meaning and indication of "Rou Ji"]

"Rou Ji", as a name of disease syndrome, played an important role with its relevant theories and clinical experiences in historical recordings. However, it was treasured neither in modern archives nor by clinical physicians. The concept of "Rou Ji" started in the Spring and Autumn Period and the Warring States Period (770 B.C. - 221 B.C.), and its name was first found in Shan Fan Fang in the Southern and Northern Dynasties (420-589). The symptoms of this disease mainly suggested weakness of limbs caused by exogenous factors. It was gradually developed into following symptoms, such like emaciation or muscle atrophy, fatigue, skin color change, abnormal skin sensation, poor digestion and absorption function of spleen and stomach. Its etiology was changed from exogenous factors into internal injuries and deficiency of congenital Qi. Its treatment was also changed with the change of the understanding of diseases. The dialectical thinking in its treatment in ancient medical materials may have reference value for current clinical diagnosis and treatment.

[A multicenter randomized controlled study of bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang in the treatment of patients newly diagnosed with Helicobacter pylori infection and dyspepsia]

Objective: To investigate the Helicobacter pylori (H. pylori) eradication rate and improvement of dyspepsia in patients who were newly diagnosed with H. pylori infection and dyspepsia and treated by bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang(JHWK). Methods: Patients who were newly diagnosed with dyspepsia and H. pylori infection and treated in 16 medical centers in China between December 1, 2017 and September 30, 2019 were randomly divided into two groups. The experimental group received bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days), followed by JHWK (30 days), and the course of treatment was 44 days in total. In the control group, the administration regimen was bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days). The main outcome measure was H. pylori eradication rate, while the secondary outcome measures were dyspepsia symptom changes and adverse events during the treatment and the 1st month after treatment. Results: A total of 1 054 patients were included in the study. There were 522 cases enrolled in the experimental group, including 224(42.91%) men and 298(57.09%) women, and the age was 53(26, 73) years old; 532 cases enrolled in the control group, including 221(41.54%) men and 311(58.46%) women, and the age was 46(22, 71) years old. Based on PP analysis, it was found that the H. pylori eradication rate in the experimental group was significantly higher than those in the control group (93.85% vs 87.88%, P=0.001). In the group of all enrolled patients, the symptom dyspepsia after H. pylori eradication was significantly improved compared with that before treatment [4(4, 7) vs 15(10, 22), P<0.001], so was the superior and middle abdominal pain [1(1, 4) vs 4(1, 8), P<0.001], the postprandial fullness [1(1, 4) vs 4(4, 9), P<0.001], the early satiety [1(1, 1) vs 4(1, 4), P<0.001], and the heartburn [1(1, 1) vs 1(1, 4), P<0.001]. The symptom dyspepsia after treatment was significantly improved compared with that before treatment in the experimental, the control groups, the successful and the unsuccessful H. pylori eradication groups. The superior and middle abdominal pain after treatment was signifcantly improved than that before treatment [1(1, 2) vs 1(1, 4), P<0.001], so were the postprandial fullness [1(1, 3) vs 1(1, 4), P=0.002] and the dyspepsia[4(4, 7) VS 7(4, 10), P<0.001]. There was no statistically significant difference in the incidence of adverse events between the experimental group and the control group (1.34% vs 0.38%, P=0.09). Conclusions: Compared with bismuth-containing quadruple therapy, bismuth-containing quadruple therapy followed by JHWK significantly improves the H. pylori eradication rate without increasing the incidence of adverse events. H. pylori eradication therapy can improve symptoms of patients with H. pylori infection and dyspepsia.

Rendezvous endovascular common carotid artery stenting (RECCAS) technique for symptomatic steno-occlusive disease

This report describes a patient who presented with acute but transient right arm weakness and altered sensation secondary to severe stenosis of the left common carotid artery (CCA) origin. Endovascular stenting of the stenosed origin was achieved utilising a novel rendezvous technique through combined retrograde common carotid artery and anterograde transfemoral approaches. This technique has numerous potential advantages over traditional transfemoral endovascular and open retrograde common carotid artery approaches. It allows increased procedural control and success in traversing the stenosis and provides a smooth transition for the stent delivery catheter. An open cutdown procedure or open surgical technique is not required. Our patient recovered well from the procedure with no complications within the three-month follow up period.

Abstract 2277: Machine learning to identify prostate cancer mutations for screening cell-free DNA (cfDNA)

Cell free DNA (cfDNA), a form of ‘liquid biopsy', has recently emerged as a promising technology to screen, diagnose, and monitor many types of disease. However, in the context of cancer, one unfortunate complication of cfDNA's use as a biomarker is the weak signal-to-noise ratio that arises primarily due to DNA contamination from healthy tissue DNA. To circumvent this, many researchers have focused on a limited set of frequently observed coding variants within a single gene or a small panel of hand selected genes, trading breadth for depth to improve signal. This approach, while sensible, can lead to detection issues in highly heterogeneous diseases— such as prostate cancer— in which variants may not be universally present at high proportion across all patients. Furthermore, many of these panels ignore regions that are non-coding but functional, and possibly even crucial in tumorigenesis.

This project proposes a different, agnostic, and machine-learning based approach for panel generation. Using public whole genome sequence (WGS) datasets containing single nucleotide polymorphisms (SNPs) and copy variant information from the International Cancer Genome Consortium (ICGC) as training data and a large number of annotation features collected from a dozen biological databases, we've developed an open source push-button tool called orchid to build cancer variant prediction models. After training a Support Vector Machine (SVM) on known prostate cancer mutations in patients with few mutations (putatively driver enriched) and those in patients with many mutations (putatively passenger enriched), the model was used to suggest a set of mutations most “prostate cancer like”. Mutations furthest from the classifying hyperplane are then selected to form the SVM panel.

Compared to manually curated panels, the SVM panel demonstrates superior in silico patient detection in both untrained ICGC data and in tumor/normal sequence data from a pilot study of 13 prostate cancer patients with multiple heterogeneous tumor foci. Moving forward, the SVM generated panel will be used to screen cfDNA from patients in the pilot study and 100 additional UCSF prostate cancer patients.

This research has clinical implications in creating diagnostic, prognostic, and predictive tools for prostate cancer. In particular, the SVM panel may be used to screen cfDNA for cancer mutations and to assess tumor heterogeneity and residual disease. Additionally, the published software tool orchid can be used for other tumor mutation classification tasks, such as determining tissue-of-origin from cfDNA fragments using only the locations of mutations in the fragments.

Citation Format: Clinton L. Cario, Lancelote Leong, Man-Tzu Wang, John Witte. Machine learning to identify prostate cancer mutations for screening cell-free DNA (cfDNA) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2277.

Abstract 435: Regulation of macropinocytosis-dependent cell survival in pancreatic cancer cells

Cancer cells utilize multiple scavenging mechanisms to support growth in nutrient-poor, hypoxic environments. Signaling pathways to accommodate these mechanisms may not be required for oncogenesis per se but are crucial for cancer cell survival. These processes, known as non-oncogene addiction, can be conferred by specific oncogenes that reprogram metabolism or by the tumor microenvironment. Understanding how these pathways are regulated can provide novel opportunities for therapeutic intervention.

Studies showed that KRAS-mutant cancer cells, including pancreatic ductal adenocarcinoma (PDAC), upregulate macropinocytosis, a caveolin- and clathrin-independent endocytic process, to import extracellular protein to support growth upon nutrient depletion. Similarly, high levels of macropinocytic uptake are observed in PDAC murine models and also in human PDAC specimens. This process serves as a scavenging mechanism for cancer cells to survive and proliferate in nutrient-deprived tumor microenvironments. Thus, uncovering the key players of this pathway and the mechanisms underlying their regulation will be important to find potential therapeutic targets.

Here, we used the Informer set of small molecules to screen regulators of survival in culture conditions supplemented with either glutamine or extracellular protein. The Informer set drug library consists of small molecules including FDA-approved drugs and clinical candidates that have high selectivity for their targets and regulate many cellular pathways. We find that survival of cells grown in conditions supplemented with glutamine or exogenous protein is differentially regulated by distinct drug subsets. This suggests that different pathways of nutrient uptake, processing, and utilization are used in cells depending on the nutrient source. Further examination to determine the mechanism of pathway inhibition and applicability may unravel potential uses for therapeutics.

Citation Format: Sung Eun Kim, Man-Tzu Wang, Frank McCormick. Regulation of macropinocytosis-dependent cell survival in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 435. doi:10.1158/1538-7445.AM2017-435

K-Ras Promotes Tumorigenicity through Suppression of Non-canonical Wnt Signaling

K-Ras and H-Ras share identical effectors and have similar properties; however, the high degree of tumor-type specificity associated with K-Ras and H-Ras mutations suggests that they have unique roles in oncogenesis. Here, we report that oncogenic K-Ras, but not H-Ras, suppresses non-canonical Wnt/Ca(2+) signaling, an effect that contributes strongly to its tumorigenic properties. K-Ras does this by binding to calmodulin and so reducing CaMKii activity and expression of Fzd8. Restoring Fzd8 in K-Ras mutant pancreatic cells suppresses malignancy, whereas depletion of Fzd8 in H-Ras(V12)-transformed cells enhances their tumor initiating capacity. Interrupting K-Ras-calmodulin binding using genetic means or by treatment with an orally active protein kinase C (PKC)-activator, prostratin, represses tumorigenesis in K-Ras mutant pancreatic cancer cells. These findings provide an alternative way to selectively target this "undruggable" protein.

Abstract 690: In vivo modeling identifies RB1 suppression and inactivation as being responsible for acquired PD0332991 resistance in glioblastoma

The observation of glioblastoma (GBM) acquiring resistance to treatment is a well-established clinical reality. Increased understanding of GBM adaptive mechanisms to specific therapies is important for achieving improved treatment outcomes for patients, by targeting adaptive responses of tumors. Herein, we investigated GBM xenograft adaptation to sustained cdk4/6 inhibition, which we have previously shown to inhibit the growth of p16 deficient GBM xenografts. To understand GBM adaptation to sustained cdk4/6 inhibition, mice with intracranial U87 xenografts were administered daily PD0332991. Resected tumors from three mice, at time of required euthanasia from tumor burden, were transplanted subcutaneously into the flanks of mice that continued to receive daily PD0332991. At 34 to 145 days of continuously daily treatment, subcutaneous tumors began to grow rapidly, suggesting tumor adaptation to sustained treatment. One of the subcutaneous tumors, beginning to grow rapidly while being subjected to daily PD0332991 treatment, was resected and used in developing a cell suspension that was intracranially injected in a series of mice for analysis of tumor response to PD0332991 by bioluminescence imaging and survival analysis. Cells from resected, PD0332991-resistant tumor were used for in vitro propagation and associated analysis of cell cycle distributions, and for the activation state of cell proliferation. Mice intracranially injected with PD0332991-resistant U87 cells, and receiving continued daily treatment with PD0332991, experienced no survival benefit relative to untreated mice bearing the same tumors, supporting our development of a PD0332991 resistant derivative of U87. Interestingly, tumors established from PD0332991 resistant cells showed more rapid intracranial growth than tumors established from previously untreated U87 cells, resulting in significantly reduced survival of mice bearing PD0332991 resistant tumors. In vitro, PD0332991-resistant cells did not exhibit growth arrest upon exposure to PD0332991, whereas previously untreated U87 cells arrested when treated with PD0332991. Expression analysis of cell cycle regulatory proteins by western blotting revealed that PD0332991 resistant cells were deficient in Rb protein expression, in contrast to control U87, being positive for Rb expression. FISH and PCR revealed deletion of RB gene as being responsible for the lack of Rb protein in PD0332991 resistant U87. Furthermore, PD0332991 resistant cells were examined using RTK arrays, revealing PD0332991 resistance as being accompanied by increased activation of Akt signaling. Our results suggest the potential of p16 deficient tumors to adapt to sustained PD0332991 treatment by genetic inactivation of RB. Moreover, concurrent inhibition of Akt, in treating p16 deficient tumors, could possibly prevent tumor adaptation to cdk4/6 inhibitor therapy.

Citation Format: Yu-Jen Lu, Man-Tzu Wang, Todd Waldman, Tomoko Ozawa, David James. In vivo modeling identifies RB1 suppression and inactivation as being responsible for acquired PD0332991 resistance in glioblastoma. [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 690. doi:10.1158/1538-7445.AM2014-690

Abstract 4970: The role of POU5F1B in prostate cancer

POU5F1B is the one of the pseudogenes of POU5F1 (also known as Oct3, Oct4) with protein-coding potential. It is localized on chromosome 8q24.21, inside of the 1.2 Mb “gene desert” between the FAM84B and the c-MYC gene, which is closely associated with prostate cancer risk. Recent studies shown that POU5F1B, but not POU5F1, is expressed in prostate tissue and is overexpressed in prostatic carcinoma, compared to normal prostatic tissue surrounding the carcinoma. However, the role of POU5F1B in prostate cancer is still unknown. Through in silico analysis of dataset HG-U95A, we found that POU5F1B expression is increased in prostate tumor and markedly increased in metastatic tumors. Western blot analysis revealed a marked increase in POU5F1B expression in prostate cancer cells when compared to non-tumorigenic RWPE-1 cells. To study the role of POU5F1B in prostate cancer, we cloned POU5F1B from prostate cancer cells, sequenced the amplicons, and found several polymorphism. We made pCDH-myc-POU5F1B constructs and expressed POU5F1B in prostate cancer cell lines LNCaP, DU145, and PC-3. Prostate cancer cell lines that ectopically overexpress POU5F1B form dramatically fewer cell-cell junctions and exhibit significantly increased invasiveness in vitro. Further, we found that E-Cadherin expression is downregulated in DU145-POU5F1B cells. Methylation of the E- Cadherin locus is increased in DU145-POU5F1B cells and methyltransferase inhibitors can partially restore E-Cadherin expression. These data collectively suggest an important role of POU5F1B in prostate tumor progression and metastasis.

Citation Format: Hongmei Jiang, Man-Tzu Wang, Daotai Nie. The role of POU5F1B in prostate cancer. [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 4970. doi:10.1158/1538-7445.AM2014-4970

Abstract 2327: Oncogenic K-Ras and H-Ras differentially regulate cancer stem cell-like properties via repression of non-canonical Wnt signaling

Cancer stem cells (CSCs) can cause cancer treatment failures and tumor recurrence due to their stem cell-like properties, such as the unlimited self-renewal, tumorigenicity, and chemo-resistance. Ras is the most common oncogene in human cancers, but its roles in stem cell-like properties have not been convincingly demonstrated. With a high degree of sequence homology as well as common sets of downstream effectors and upstream affecters, the three isoforms of Ras, N-, H- and K-Ras, have long been assumed to be functionally redundant. However, knockout of K-Ras, not N- or H-Ras, in mice leads to embryonic lethality, suggesting a non-redundant role of K-Ras in embryonic development. Herein, we report that oncogenic K-Ras, differentially from H-Ras, causes CSC-like properties in transformed mouse fibroblast and pancreatic cancer cells. When compared to the NIH3T3 cells with H-RasV12, the cells transformed with K-RasV12 demonstrated significantly enhanced sphere forming efficiency, elevated resistance toward cisplatin, and heightened sensitivity to the CSC inhibitor, salinomycin, while the RasGTPase, p-Erk and p-Akt activities are comparable. In the comparison with H-RasV12 transformed cells, K-RasV12 transformed NIH3T3 cells possessed significantly increased tumor initiating frequency in limited cell transplantation and in vivo serial transplantation assays. Through stem cell signaling-related genes focusing PCRarray, we further identified Frizzled 8 (Fzd8), a Wnt receptor and potential activator of non-canonical Wnt/Ca2+ signaling, was significantly down-regulated in K-RasV12 transformed NIH3T3 cells when compared to normal cells or H-RasV12- transformed cells. In clinical human pancreatic tissues, Fzd8 was dramatically reduced in malignant specimens, whereas normal tissue showed high expressions of Fzd8. Knockdown of K-Ras in pancreatic cancer cells led to significant increases in Fzd8 at RNA and protein levels, suggesting oncogenic K-Ras repress the expression of Fzd8. TOPFlash assay revealed that K-RasV12 transformed NIH3T3 had dramatically enhanced canonical beta-catenin activity when compared to normal or H-RasV12- transformed cells. Human pancreatic cancer cells with K-Ras knocked down showed significantly reduced canonical beta-catenin activity. In a syngenic mouse model, over-expression of Fzd8 in oncogenic K-Ras driven mouse pancreatic cancer cells delayed the orthotropic tumor formation, and further decreased peritoneal metastatic spreads. Our data collectively suggest that oncogenic K-Ras regulates the stem cell-like properties of cancer cells, differentially from oncogenic H-Ras, through repression of Fzd8-mediated non-canonical Wnt/Ca2+ signaling. Restoration of Fzd8 suppressed oncogenic K-Ras induced pancreatic tumorigenesis, providing an alternative way to target this “undruggable” oncogene.

Citation Format: Man-Tzu Wang, Jacqueline Galeas, Cayde Ritchie, Frank McCormick. Oncogenic K-Ras and H-Ras differentially regulate cancer stem cell-like properties via repression of non-canonical Wnt signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2327. doi:10.1158/1538-7445.AM2013-2327

Abstract LB-281: The role of POU5F1B in prostate cancer

POU5F1B is the one of the pseudogenes of POU5F1 (also known as Oct3, Oct4) with protein-coding potential. It is localized on chromosome 8q24.21, inside of the 1.2 Mb “gene desert” between the FAM84B and the c-MYC gene, which is closely associated with prostate cancer risk. Recent studies showed that POU5F1B, but not POU5F1, is expressed in prostate tissue and is overexpressed in prostatic carcinoma, compared to normal prostatic tissue surrounding the carcinoma. However, the role of POU5F1B in prostate cancer is still unknown. Through in silico analysis of dataset HG-U95A, we found that POU5F1B expression is increased in prostate tumor and markedly increased in metastatic tumors. Western blot analysis revealed a marked increase in POU5F1B expression in prostate cancer cells when compared to non-tumorigenic RWPE-1 cells. To study the role of POU5F1B in prostate cancer, we cloned POU5F1B from prostate cancer cells, sequenced the amplicons, and found several polymorphism. We made pCDH-myc-POU5F1B constructs and expressed POU5F1B in prostate cancer cell lines LNCaP, DU145, and PC-3. Overexpression of POU5F1B in LNCaP, DU145 and PC3 cells can increase cell invasion using Boyden chamber assay. Overexpression of POU5F1B in LNCaP cells also promotes colony formation in soft agar. We also found that DU145 cells with POU5F1B overexpression lost cell-cell contact, compared to DU145-pCDH vector cells, and further found that CDH1 expression is downregulated in DU145-POU5F1B cells. Depletion of POU5F1B reduced the tumor forming ability of LNCaP cells in vivo. The data collectively suggest an important role of POU5F1B in prostate tumor formation and progression.

Citation Format: Hongmei Jiang, Man-Tzu Wang, Daotai Nie. The role of POU5F1B in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-281. doi:10.1158/1538-7445.AM2013-LB-281

Abstract 5006: SOX2 inhibits Wnt driven colon cancer cell proliferation

APC mutation/s resulting in aberrant Wnt signaling, initiates intestinal polyposis and drives adenoma to carcinoma progression in human colon. This represents a target for specific therapeutic intervention and has generated extreme interest among the scientific community. However, it is becoming increasingly apparent that though Wnt signaling may cause robust proliferation, it is the quiescent cell population, defined by stem-ness related gene signatures, that evades chemo-radio therapy targeted at rapidly dividing cells, and perpetuates self-renewal ultimately causing relapse at local site and/or recurrence as distant metastases. We report that SOX2, an embryonic stem cell transcription factor, counteracts Wnt driven tumor cell proliferation and maintains quiescence in colo-rectal cancers (CRC).

SOX2 expression increases with progressive staging of colon cancer patients. Using colon cancer cell lines transduced with Wnt reporter constructs, we identified distinct sub-populations with varying degrees of Wnt activity and found that SOX2 expression and Wnt activity are mutually exclusive in SW480 primary CRC cell line, but co-expressed in the isogenic SW620 metastatic CRC cell line. Knockdown of SOX2 in SW620 cell increased anchorage independence in vitro and tumor growth in xenograft models. This was accompanied by an increase of cells in S-phase and increased Ki67 index in IHC of xenograft tissue. Over-expression of SOX2 in SW480 cells resulted in decreased colony formation in soft agar and primary tumor growth in mice. Over-expression also caused increased fraction of cells in G0-G1 phase and decreased Ki67 staining in tumor tissue.

In SW620 cell line, SOX2 knockdown not only increased basal Wnt activity, but also caused acquisition of Wnt activity in hitherto Wnt negative cells. Intriguingly, over-expression of SOX2 in SW480 cells, reversed the enhanced Wnt activity gained by loss-of-function APC mutation. Experiments conducted with both SOX2 silenced and over-expressed cell lines revealed that SOX2 inhibits phosphorylation of

β-catenin at Serine 552 and 675 thereby decreasing its nuclear sequestration and activation. Screening with protein kinase and phosphatase inhibitors identified PHLPP and PHLPPL as candidate genes that are controlled by SOX2 and are responsible for its effects on β-catenin. Western Blot and qPCR analyses showed that SOX2 enhances PHLPP/L expression. Reporter assays demonstrated that SOX2 controls PHLPP/L promoter activity while ChIP assays confirmed binding of SOX2 to various regions of the respective promoters. IHC of SOX2 silenced xenograft tissue showed decreased PHLPP/L and increased pβ-catenin staining while SOX2 over-expression showed reciprocal changes.

Our findings delineate the mechanism by which CRC cells suppress Wnt activity thereby maintaining a pool of quiescent cancer cells, and lay the basis for further research to identify and target these cells.

Citation Format: Debasish Boral, Man-Tzu Wang, Daotai Nie. SOX2 inhibits Wnt driven colon cancer cell proliferation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5006. doi:10.1158/1538-7445.AM2013-5006

Abstract 3059: Pseudokinase Trb3 inhibits tumor cell growth and promotes a G2/M phase cell cycle arrest in prostate cancer

INTRODUCTION Mammalian homolog Tribbles (Trbs) is a newly characterized protein family that includes three different isoforms: Trb1, Trb2, and Trb3.Tribbles are serine/threonine kinases lacking catalytic activity, thus their classification as pseudokinases. Despite their catalytic inactivity, Tribbles can interact with different proteins and regulate different biological functions. The most studied tribble family member, Trb3, was reported to play a major role in Drosophila's ventral furrow formation. Further studies revealed that Trb3 is also involved in diabetes, stress-response, and development. Previously, Trb3 upregulation was detected in certain types of cancer but its function remains unknown. The goal of this study is to gain a better understanding of the biological function of Trb3 in cancer, including the molecular mechanism of action. METHODS To determine the role of Trb3 in tumorigenesis, Trb3 expression was compared in normal, primary and metastatic tissue using cohort GSE-6919. Small hairpin RNA GIPZ construct was used to deplete Trb3 in prostate cancer DU145 cell line. Conversely, Trb3 was ectopically overexpressed in prostate cancer PC-3 cells using CMV-driven Trb3 expression vector. Then subsequent effects on cell proliferation and cell cycle progression were studied. The MTS and Brdu incorporation assays were used to assess cell proliferation. Cell cycle analysis was performed using flow cytometry of propidium iodide stained cells. Western blot analysis was used to identify proteins regulated post silencing or overexpression of Trb3. RESULTS Using the cohort analysis, we identified higher levels of Trb3 in the primary tumor compared to the normal tissue. Silencing of Trb3 in DU145 promoted cell growth and higher colony formation ability. Cell cycle analysis revealed an increase in S phase in Trb3 silenced DU145. Furthermore, the cell proliferation protein Ki67 was increased in DU145 cells with Trb3 silenced. Cyclin D1 levels were reduced. However, active cdc25c, a phosphatase that promotes cell entry into mitosis, was increased. On the other hand, overexpression of Trb3 in prostate cancer PC-3 inhibited tumor cell proliferation, reduced colony formation, and induced cell cycle arrest at G2/M phase. CONCLUSION In this study, we found that knocking down of Trb3 in prostate cancer promotes cell proliferation and colony formation ability by increasing proliferation protein KI67, while reducing cyclin D1 levels. Furthermore, the phosphatase cdc25c is activated resulting in an enhanced entry into mitosis. Conversely, Trb3 overexpression has an antiproliferative effect and inhibits colony formation ability. Trb3 also promotes a G2/M phase arrest in prostate cancer PC-3 cells. Our results suggest that Trb3 is activated in the primary tumor to prevent tumor growth by promoting cell cycle arrest.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3059. doi:1538-7445.AM2012-3059

Abstract LB-292: NANOG promotes chemoresistance in prostate carcinoma cells

NANOG promotes chemoresistance in prostate carcinoma cells Hongmei Jiang, Man-Tzu Wang, Daotai Nie The emergence of drug resistant prostate cancer cells is a leading cause of chemotherapy failure in patients with prostate cancer. The mechanisms behind the acquisition of chemoresistance in prostate cancers are, however, poorly understood. NANOG is a transcription factor associated with the self-renewal of embryonic stem cells. Expression of NANOG has been detected in a number of cancer cells, and its expression linked with those positive for stem/progenitor markers. In the present studies, several lines of evidence are presented to suggest that NANOG regulates tumor responses to chemotherapy. First, in the surviving fractions of tumor cells after chemotherapy, there was an elevated level of NANOG expression and activities. Second, prospective enrichment of tumor cells with endogenous NANOG expression led to enrichment of tumor cells resistant to taxol, vinblastine, and doxorubicin. Knockdown of NANOG expression via small hairpin RNAs (shRNAs) sensitized tumor cells toward chemotherapeutics. Real-time PCR array identified an enhanced expression of the ATP-binding cassette efflux transporter B1 (ABCB1) and G2 (ABCG2) in tumor cells enriched with endogenous NANOG expression. Inhibition of ABCB1 activities or knockdown of ABCB1 expression attenuated, but not abolished, the increased resistance in NANOG expressing cells toward taxol and vinblastine. Knockdown of ABCG2 attenuated the resistance of NANOG-expressing tumor cells toward doxorubicin. Together, our results suggest that NANOG confers tumor cells with increased resistance to chemotherapy partially through regulating the expression of ABC transporters.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-292. doi:1538-7445.AM2012-LB-292

Abstract 4379: Role of Nanog in resistance of prostate cancer cells toward chemotherapy

Drug resistance is a major barrier to efficacious chemotherapy. Cancer stem cells (CSCs) may pose resistance to chemo- or radio-therapy, but the mechanism remains unknown. Nanog is a transcription factor essential for self-renewal of embryonic stem cells. The expression of Nanog has been reported in some cancer cells but its role in resistance to chemotherapy has not been convincingly demonstrated. Herein, we report that Nanog is expressed in tumorigenic prostate cancer cells and further it contributes to chemoresistance.

Nanog expression was detected in prostate cancer cells by Western blot and RT-PCR and confirmed by sequencing. In the surviving fractions of prostate cancer cells after chemo-treatments, we found increased levels of Nanog expression and activities when compared to vehicle control-treated group. To determine the role of Nanog in resistance of prostate cancer cells, we marked and enriched Nanog-expressing prostate cancer DU145 using a reporter gene under control of 2.5 kb hNanog1 promoter. When compared to the control, the prospectively enriched Nanog-expressing cells had enhanced endogenous Nanog expression, increased positivity for stem/progenitor markers (CD44 and CD133), and presented increased resistance to Taxol, vinblastine, and doxorubicin, but not camptothecin (CPT). In addition, Nanog-enriched DU145 cells showed reduced apoptosis in the response to Taxol treatment, whereas control cells had increased activation of effector caspases after treatment with Taxol. Colony formation assay revealed that prostate tumor cells with enriched Nanog expression displayed increased recurrent ability after chemotherapy. Knockdown of Nanog by tet-inducible shRNA sensitized prostate tumor cells to multiple drug treatments, suggesting its essential role in prostate cancer chemo-resistance. Profiling of genes in drug resistance and metabolism revealed a marked increase in the mRNA levels of ATP-binding cassette (ABC) efflux transporters B1 and G2 in tumor cells enriched with endogenous Nanog expression. The increased expression of ABCB1 and ABCG2 in Nanog expressing cells was confirmed by Western blot and immunocytochemistry. Inhibition of ABCB1 activities or knockdown of ABCB1 expression sensitized Nanog expressing cells toward Taxol and vinblastine, but not doxorubicin. Knockdown of ABCG2 sensitized Nanog expressing cells toward doxorubicin, and to lesser extent, vinblastine, but not Taxol. Knockdown of Nanog reduced the expression of ABCB1 and ABCG2 and reduced the resistance of tumor cells toward chemotherapy.

In summary, Nanog expression is associated with tumor cells positive for stem/progenitor markers and resistant to chemotherapy. The gain-of-function and loss-of-function studies suggest an essential role of Nanog for prostate cancer cells to resist chemotherapy via regulating the expression of ABC transporters.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4379. doi:10.1158/1538-7445.AM2011-4379

Abstract 3330: Nanog, cancer stem cells, and resistance to chemotherapy

It has been increasingly appreciated that cancer stem cells are responsible for initiating tumor formation as well as resistance to chemoradiotherapy, but the mechanisms involved remain unknown. Nanog is a transcription factor essential for self-renewal of embryonic stem cells. The expression of Nanog has been reported in some cancer cells but its role in tumor initiation and resistance to chemotherapy has not been convincingly demonstrated. Herein, we report that Nanog is expressed in tumorigenic prostate cancer cells and further it plays an essential role of Nanog in tumor formation and resistance to chemotherapy. Enrichment for Nanog-expressing tumor cells led to an increase in the number of cells positive for stem/progenitor markers, increased clonogenic growth, and increased ability to form prostaspheres. When injected into mice, enriched Nanog-expressing cells formed tumors earlier and formed larger tumors than the vector control cells did. Knockdown of Nanog in tumorigenic cancer cells, via small hairpin RNAs, reduced clonogenic growth, stimulated epithelial differentiation, and significantly compromised their tumor initiating ability. Prospective enrichment of tumor cells with endogenous Nanog expression also led to enrichment of tumor cells resistant to Taxol, vinblastine, and doxorubicin, but not camptothecin (CPT). The increased resistance in Nanog expressing cells was attenuated, but not abolished, by inhibitors of p-glycoprotein, the ATP-bind cassette efflux transporter B1 (ABCB1), or by knockdown of ABCB1 via small hairpin RNAs (shRNAs). Expression of ABCB1 was increased in tumor cells enriched with endogenous Nanog expression while knockdown of Nanog reduced the expression of ABCB1 and sensitized tumor cells toward chemotherapeutics. Taken together, the data from gain-of-function and loss-of-function studies suggest an essential role of Nanog for prostate cancer cells to self-renew or propagate, to initiate tumor formation, and to resist chemotherapy via regulating the expression of ABC transporters.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3330.

Impairment of mitochondrial respiration in mouse fibroblasts by oncogenic H-RAS(Q61L)

A common metabolic change in cancer is the acquisition of glycolytic phenotypes. Increased expression of glycolytic enzymes is considered as one contributing factor. The role of mitochondrial defects in acquisition of glycolytic phenotypes has been postulated but remains controversial. Here we show that functional defects in mitochondrial respiration could be induced by oncogenic H-Ras(Q61L) transformation, even though the mitochondrial contents or mass was not reduced in the transformed cells. First, mitochondrial respiration, as measured by mitochondrial oxygen consumption, was suppressed in NIH-3T3 cells transformed with H-Ras(Q61L). Second, oligomycin or rotenone did not reduce the cellular ATP levels in the H-Ras(Q61L) transformed cells, suggesting a diminished role of mitochondrial respiration in the cellular energy metabolism. Third, inhibition of glycolysis with iodoacetic acid reduced ATP levels at a much faster rate in H-Ras(Q61L) transformed cells than in the vector control cells. The reduction of cellular ATP levels was reversed by exogenously added pyruvate in the vector control cells but not in H-Ras(Q61L) transformed cells. Finally when compared to the HRas(Q61L) transformed cells, the vector control cells had increased resistance toward glucose deprivation. The increased resistance was dependent on mitochondrial oxidative phosphorylation since rotenone or oligomycin abolished the increased survival of the vector control cells under glucose deprivation. The results also suggest an inability of the H-Ras(Q61L) transformed cells to reactivate mitochondrial respiration under glucose deprivation. Taken together, the data suggest that mitochondrial respiration can be impaired during transformation of NIH-3T3 cells by oncogeneic H-Ras(Q61L).

Abstract A160: Regulation of resistance of prostate cancer cells to chemotherapy by nanog, a transcription factor for self-renewal of stem cells

Nanog is a transcription factor usually expressed in embryonic stem cells that plays essential role in the stem cell self-renewal. Expression of Nanog has been detected in a number of cancer cells, especially in those positive for stem/progenitor markers. In the present studies, it was found that there was elevated expression of Nanog in the surviving fractions of tumor cells after chemotherapy. Prospective enrichment of tumor cells with endogenous Nanog expression led to enrichment of tumor cells resistant to Taxol, vinblastine, and doxorubicin, but not camptothecin (CPT). The increased resistance in Nanog expressing cells was attenuated, but not abolished, by inhibitors of p-glycoprotein, the ATP-bind cassette efflux transporter B1 (ABCB1), or by knockdown of ABCB1 via small hairpin RNAs (shRNAs). Expression of ABCB1 was increased in tumor cells enriched with endogenous Nanog expression while knockdown of Nanog reduced the expression of ABCB1 and sensitized tumor cells toward chemotherapeutics. Together, our results suggest that Nanog confers tumor cells with increased resistance to chemotherapy via regulating the expression of ABC transporters.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A160.

Downregulation of vascular endothelial growth factor and induction of tumor dormancy by 15-lipoxygenase-2 in prostate cancer

The enzyme 15-lipoxygenase-2 (15-LOX-2) utilizes arachidonic acid, a polyunsaturated fatty acid, to synthesize 15(S)-hydroxyeicosatetraenoic acid. Abundantly expressed in normal prostate epithelium but frequently suppressed in the cancerous tissues, 15-LOX-2 has been suggested as a functional suppressor of prostate cancer, but the mechanism(s) involved remains unknown. To study the functional role of 15-LOX-2 in prostate cancer, we expressed 15-LOX-2 as a fusion protein with GFP in DU145 and PC-3 cells and found that 15-LOX-2 increased cell cycle arrest at G0/G1 phase. When injected into athymic nu/nu mice, prostate cancer cells with 15-LOX-2 expression could still form palpable tumors without significant changes in tumorigenicity. But, the tumors with 15-LOX-2 expression grew significantly slower than those derived from vector controls and were kept dormant for a long period of time. Histological evaluation revealed an increase in cell death in tumors derived from prostate cancer cells with 15-LOX-2 expression, while in vitro cell culture conditions, no such increase in apoptosis was observed. Further studies found that the expression of vascular endothelial growth factor A (VEGF-A) was significantly reduced in prostate cancer cells with 15-LOX-2 expression restored. Our studies suggest that 15-LOX-2 suppresses VEGF gene expression and sustains tumor dormancy in prostate cancer. Loss of 15-LOX-2 functionalities, therefore, represents a key step for prostate cancer cells to exit from dormancy and embark on malignant progression in vivo.

Thromboxane A2 receptors in prostate carcinoma: expression and its role in regulating cell motility via small GTPase Rho

Thromboxane A(2) (TxA(2)) is a prostanoid formed by thromboxane synthase using the cyclooxygenase product prostaglandin H(2) as the substrate. Previously, increased expression of thromboxane synthase was found in prostate tumors, and tumor cell motility was attenuated by inhibitors of thromboxane synthase. This study was undertaken to elucidate how tumor motility is regulated by TxA(2). Here, we report that human prostate cancer cells express functional receptors for TxA(2) (TP). Ligand binding assay found that PC-3 cells binded to SQ29548, a high-affinity TP antagonist, in a saturable manner with K(d) of 3.64 nmol/L and B(max) of 120.4 fmol per million cells. Treatment of PC-3 cells by U46619, a TP agonist, induced PC-3 cell contraction, which was blocked by pretreatment with the TP antagonist SQ29548 or pinane TxA(2). The migration of prostate cancer cells was significantly inhibited either by sustained activation of TP or by blockade of TP activation, suggesting that TP activation must be tightly controlled during cell migration. Further studies found that small GTPase RhoA was activated by TP activation, and pretreatment of PC-3 cells with Y27632, a Rho kinase (ROCK) inhibitor, blocked U46619-induced cell contraction. A dominant-negative mutant of RhoA also blocked U46619-induced cell contraction. Taken together, the data suggest that TPs are expressed in prostate cancer and activation of TPs regulates prostate cancer cell motility and cytoskeleton reorganization through activation of Rho.

Cyclooxygenases, prostanoids, and tumor progression

In response to various growth factors, hormones or cytokines, arachidonic acid can be mobilized from phospholipids pools and converted to bioactive eicosanoids through cyclooxygenase (COX), lipoxygenase (LOX) or P-450 epoxygenase pathway. The COX pathway generates five major prostanoids (prostaglandin D(2), prostaglandin E(2), prostaglandin F(2)alpha, prostaglandin I(2) and thromboxane A(2)) that play important roles in diverse biological processes. Studies suggest that different prostanoids and their own synthase can play distinct roles in tumor progression and cancer metastasis. COX-2 and PGE(2) synthase have been most well documented in the regulation of various aspects of tumor progression and metastasis. PGE(2), for example, can stimulate angiogenesis or other signaling pathways by binding to its receptors termed EPs. Therefore, targeting downstream prostanoids may provide a new avenue to impede tumor progression. In this review, aberrant expression and functions of several prostanoid synthetic enzymes in cancer will be discussed. The possible regulation of tumor progression by prostaglandins and their receptors will also be discussed.

Role of Rho GTPases in breast cancer

Small GTPase Rho signaling pathways regulate the growth, motility, invasion and metastasis of breast cancer cells. Aberrant Rho signaling, as results from alterations in the levels of Rho GTPase proteins, the status of activation, and the abundance of effector proteins, is found in breast cancers. Alterations of Rho signaling particularly impact the cytoskeleton, whose organization and reorganization underpin the motility of breast cancer cells during the invasive growth and metastasis of breast cancer. Progress is being made to elucidate the underlying mechanisms by which Rho GTPases activate the downstream signaling effectors. Further investigations are required for development of novel tumor therapeutic strategies targeting the Rho GTPase signaling pathways to treat breast cancer.

Human pregnane X receptor and resistance to chemotherapy in prostate cancer

Resistance to chemotherapy is a significant barrier to the effective management of prostate cancer. Human pregnane X receptor (hPXR), an orphan nuclear receptor known for its activation by many important clinical drugs, interacts with many cellular signaling pathways during carcinogenesis and is a major transcription factor regulating the expression of drug metabolism enzymes, including transporters. It is unknown whether hPXR is a determinant of drug resistance in prostate cancer. In this study, we first detected the expression of hPXR in both normal and cancerous prostate tissues. Pretreatment with SR12813, a potent and selective agonist of hPXR, led to nuclear translocation of PXR in PC-3 cells and increased expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance 1 (MDR1). SR12813 pretreatment increased resistance of PC-3 cells to Taxol and vinblastine, as assessed by viability and clonogenic survival. To further study the role of hPXR in prostate cancer drug resistance, hPXR expression was knocked down using PXR-targeting short hairpin RNAs. The activities of hPXR toward the promoter of CYP3A4 in hPXR-ablated clones decreased when compared with that of wild-type PC-3 cells. Their sensitivities to Taxol and vinblastine were enhanced by hPXR ablation. Our data here suggest that hPXR may play an important role in prostate cancer resistance to chemotherapeutics.

Human LBP-32/MGR is a repressor of the P450scc in human choriocarcinoma cell line JEG-3

Steroid hormones regulate a wide range of physiologic functions in humans. The cholesterol side-chain cleavage enzyme P450scc regulates the initial step of biosynthesis of all steroid hormones. We investigated the expression of P450scc by studying a potential regulator of P450scc, LBP-32/MGR. Using a Northern blot, we found that LBP-32/MGR mRNA was expressed mainly in the human placenta. Using radiation hybrid mapping, we identified LBP-32/MGR on human chromosome 2p25. Recombinant LBP-32/MGR protein bound preferentially to a DNA fragment from the promoter of P450scc in vitro and exhibited clear nuclear localization in transfected cells. Luciferase reporter gene assays showed that LBP-32/MGR specifically repressed transcriptional activation of the human P450scc promoter. Because placental P450scc expression is essential for pregnancy and steroid biosynthesis, the placental expression and transcriptional repressor activity of LBP-32/MGR in JEG-3 cells suggest it has a role as a transcriptional modulator of steroid biosynthesis.

Stability of 4-DMAP in solution

A stability-indicating reversed-phase performance liquid chromatographic method was developed for the detection of 4-(N,N-dimethylamino)phenol (4-DMAP) and its degradation products under accelerated degradation conditions. The degradation kinetics of 4-DMAP in aqueous solution over a pH range of 1.12-6.05 and its stability in solutions based on propylene glycol or polyethylene glycol 400 were investigated. The observed rate constants were shown to follow, apparent first-order kinetics in all cases. The pH rate profile shows that maximum stability of 4-DMAP was observed in the pH range 2.0 to 3.0. Acid/base catalysis of 4-DMAP was not affected by systems of various ionic strengths. Incorporation of nonaqueous propylene glycol or polyethylene glycol 400 in the pH 3.05 solution of 4-DMAP showed an increase in the stability at 55 degrees C +/- 0.5 degrees C.

Effects of hypoxia on granulocytic-monocytic progenitors in rats. Role of bone marrow stroma

Hemorrhagic shock leads to hypoxia and is associated with bone marrow (BM) failure. Hemorrhagic shock is also a predisposing factor in immune dysregulation. Since the BM is the major organ of immune cells in the adult, its failure following hemorrhagic shock may explain the increased susceptibility to infection. The in vitro evidence indicates that hypoxia mediates altered functions in BM stroma. Since similar hematopoietic alterations are reported in hypoxia and hemorrhagic shock, hypoxia alone could be a representative model to study BM responses during hemorrhagic shock. In this study, we use an animal model to dissect the hematopoietic effects of hypoxia. We subjected rats to hypoxia, and at days 1 and 5 post-hypoxia we determined the numbers of granulocytic-monocytic progenitors (CFU-GM) in the BM. We found significant increase (P < 0.05) in CFU-GM at day 1 and a downward trend by day 5. Enhanced BM cellularity could not explain the increase in CFU-GM by day 1. BM stromal cells mediated most of the stimulatory effects by hypoxia. CFU-GM was inversely proportional to bioactive TGF-beta and directly proportional to IL-1. Compared to normoxic rats, IL-6 production was suppressed in BM cells from hypoxic rats. The results show that hypoxia alone initiate a stimulatory response in CFU-GM progenitors. These effects are at least partially mediated through the BM stroma. In the absence of a second insult, CFU-GM reverts to baseline. The data also suggest that hypoxia mediates complex responses that include cytokine production. These results add to the current understanding of hematopoietic responses by hypoxia and adds to the mechanisms of immune dysfunctions following hemorrhagic shock.

Formulation optimization of controlled-release pellets of metoclopramide hydrochloride using dissolution fit factor approach

The purpose of this study was to optimize the formulation variables for the preparation of ethyl cellulose-coated nonpareils loaded with metoclopramide hydrochloride (MCL). The approach to evaluate the effectiveness of formulation parameters was monitored by release rate testing using dissolution fit factors as a tool. The content of ethyl cellulose used in the formulation was based on the drug-loaded weight. The interrelationship of each developed formulation and the reference formulation Gastro-Timelets and their respective dissolution curves were evaluated using Moore's equation: [equation: see text]. The relationship between the ethyl cellulose content in the formulation and the dissolution fit factor f2 can be described as the following regression equation: Y = -0.054X2 + 3.347X - 1.915 (r2 = 0.99). The optimum ethyl cellulose content obtained from the equation was 30.8%. The type and content of plasticizer used in the formulation to achieve the greatest f2 were determined to be Myvacet 9-40 at the concentration of 25%. Results indicated that using the release rate testing approach with the dissolution fit factor as a tool could provide valuable information for formulation optimization.

Percutaneous transport of diclofenac sodium from mixtures of fatty alcohol (or fatty acid) and propylene glycol through the rabbit abdominal skin

Diclofenac sodium is a nonsteroidal anti-inflammatory drug with analgesic, antipyretic, and anti-inflammatory activity. When used in a topical application, diclofenac can diffuse through the skin and into the subcutaneous tissue to effect the anti-inflammatory action. In this study, in vitro evaluations of the percutaneous transport of diclofenac sodium in various bases containing fatty alcohols/propylene glycol or fatty acid/propylene glycol mixtures through the abdominal skin of the rabbit were investigated. Results show that the transdermal flux of diclofenac sodium in the fatty alcohol/propylene glycol bases of the same ratio is affected by the chain length of the fatty alcohol, and its effect is in the order of C10 > C12 > C14 > C18. However, the transdermal flux of diclofenac sodium in the fatty acid/propylene glycol bases of the same ratio is also affected by the chain length of the fatty acid, but no absolute relationship was found. For the same chain length of fatty acid and fatty alcohol used in the formulation base that was otherwise the same, the transdermal flux of diclofenac sodium is higher in the formula containing fatty alcohol than that containing fatty acid.

Dermatoses in cement workers in southern Taiwan

Construction workers are known to have occupational dermatoses. The prevalence of such dermatoses was unknown in Taiwanese construction workers. The objective of this study was to determine the work exposure, prevalence of skin manifestations, and sensitivity to common contact allergens in cement workers of southern Taiwan. A total of 1147 current regular cement workers were telephone-interviewed about skin problems during the past 12 months, work exposure, and personal protection. Among those interviewed, 166 were examined and patch tested with common contact allergens. A high % of cement workers reported skin problems in the past 12 months. More men (13.9%) reported skin problems possibly related to work than women (5.4%). Prevalence was associated with lower use of gloves, duration of work as cement worker, and more time in jobs involving direct manual handling of cement, especially tiling. A high % of dermatitis was noted in the 166 workers examined, which correlated with reported skin problems. On patch testing, construction workers had a high frequency of sensitivity to chromate. Sensitivity to chromate or cobalt was associated with reported skin problems, or dorsal hand dermatitis on examination. These workers' dermatitis was under-diagnosed and inadequately managed. It is concluded that cement workers in southern Taiwan had a high prevalence of skin problems related to cement use. Protective measures, work practice, and physician education should be improved to prevent or manage such problems.

Preliminary study of dose equivalent evaluation for residents in radioactivity contaminated rebar buildings

It has recently been found that several resident and office buildings in Taiwan were constructed with 60Co-contaminated reinforcing steel bar (rebar). Both governmental officials and the residents of such buildings have been concerned about this finding. In order to respond to the situation, the government has adopted a number of remedial measures, including full-scale radiation survey, dose evaluation and physical examinations of residents. This article presents three methods for evaluating the dose equivalents of the residents living in the contaminated rebar buildings by means of gamma-ray survey, necklace-type thermoluminescence dosimeters (TLDs) and the human lymphocyte chromosome aberration analyses. The results reveal that the dose evaluation by gamma-ray survey is rather conservative. Generally for the residents whose annual dose equivalents are greater than 5 mSv (0.5 rem) by gamma-ray survey, the dose equivalents from necklace-type TLDs are only within the range of 20 to 50% of the evaluated values mentioned above. For chromosome analyses, at least 500 lymphocyte cells were scored and analyzed for each resident. Most of the chromosome analysis data show that the dose equivalents received by residents are lower than the detection limit of the method (100 mSv) and quite different from the estimated dose obtained from either gamma-ray survey or necklace-type TLD measurements.

Compatibility of vancomycin hydrochloride and famotidine 5% dextrose injection

The compatibility of vancomycin hydrochloride and famotidine in 5% dextrose injection stored at two temperatures was studied. Vancomycin hydrochloride and famotidine were reconstituted and diluted with 5% dextrose injection to form an admixture with a famotidine concentration of 0.2 mg/mL and a vancomycin concentration of 5 mg/mL. The admixture was stored in 100-mL vented intravenous containers in the dark at 4 and 25 deg C; three containers were stored at each temperature. A 2-mL sample was taken from each container after six and 12 hours and 1, 3, 5, 7, 10, 12, and 14 days of storage and visually inspected, tested for pH and assayed by a developed stability-indicating high performance liquid chromatographic method. Triplicate samples were prepared for each storage condition. No color change, precipitation or cloudiness was observed in any sample at any time during the study. Vancomycin 5 mg/mL and famotidine 0.2 mg/mL in admixtures in 5% dextrose injections are stable for 14 days at 4 and 25 deg C.

Differential effects of acute hypoxia and endotoxin on the secretion and expression of bone marrow interleukin-1 and interleukin-6

Hemorrhagic shock induces tissue hypoxia and has been demonstrated to alter the myelopoietic response to bacterial lipopolysaccharide (LPS). Interleukin-1 and interleukin-6 are important mediators of immunologic events after hemorrhagic shock. Bone marrow stroma release inflammatory cytokines, which may play a role in the regulation of myelopoiesis after injury. The aim of this study was to correlate cytokine gene expression with protein release and myelopoiesis by total bone marrow cells. The role of bone marrow stroma after exposure to hypoxia and lipopolysaccharide was also examined. BALB/c mice were designated as normoxia or hypoxia and total bone marrow cells were harvested. Hypoxia mice were exposed to 2 h of 5% O2/95% N2, and then returned to room air. Additional groups of mice were given LPS intraperitoneally. Bone marrow stroma, from BALB/c mice, was similarly designated. Myelopoiesis was assessed by growth of granulocyte-macrophage progenitor cells (CFU-GM). Interleukin-1 and interleukin-6 protein activity was assessed by bioassay. RNA was extracted from both total bone marrow cells and bone marrow stroma. By day 5, LPS alone resulted in a 93% increase in CFU-GM versus normoxia. Hypoxia and LPS exposure significantly decreased CFU-GM on days 1, 3, and 5. LPS alone induced an increase in interleukin-6. At 2, 6, and 24 h, hypoxia blunted interleukin-6 release in response to LPS. Hypoxia alone could not induce interleukin-6. However, hypoxia did induce interleukin-1 mRNA without the release of bioactive protein. In the remainder of groups, interleukin-1 protein levels and mRNA levels were correlated. Bone marrow stroma interleukin-1 and interleukin-6 protein activity was consistently correlated with that of total bone marrow. These data demonstrate that bone marrow cytokine production is differentially regulated by hypoxia. Hypoxia impairs interleukin-6 protein and mRNA in response to LPS, which may play a role in the suppression of myelopoiesis after shock. Also, bone marrow stroma plays an integral role in regulating myelopoiesis.

Hemorrhagic shock abolishes the myelopoietic response to turpentine-induced soft tissue injury

Hemorrhagic shock has been shown to alter bone marrow (BM) myelopoiesis. Isolated hemorrhagic shock is uncommon after trauma and the combined effect of tissue injury and shock on myelopoiesis is unknown. We studied the growth of BM granulocyte-macrophage colony forming units (CFU-GM) following shock and soft tissue injury. Rats were anesthetized and allocated into one of four groups: CONTROL, sham neck dissection; SHOCK, rats were bled to a mean BP of 45 mmHG for 45 min and resuscitated with shed blood and saline; TURP, soft tissue injury was induced by turpentine 0.5 ml/100 g SQ into the hindquarter; SHOCK + TURP, rats received TURP just before SHOCK as described above. Groups (n = 6) were sacrificed 1, 3, and 5 days after treatment. BM cells plated for CFU-GM and splenic macrophages were cultured for IL-1 production. Unstimulated splenic macrophage production of IL-1 alpha was not different for any group except Day 5 turpentine animals. TURP induced a significant increase in CFU-GM on Day 1 compared to that in control (47 +/- 22 vs 21 +/- 11; P < 0.05). SHOCK completely abolished this response to TURP. Both the SHOCK and TURP alone increased CFU-GM on Day 5 compared to that in CONTROL but there was no additive effect in the SHOCK + TURP group. These data show that the BM response to combined soft tissue injury and shock (TURP + SHOCK) appears similar to that of SHOCK alone and that hemorrhagic shock appears to be a significant immunosuppressive factor in the regulation of myelopoiesis following injury.

Clinical significance of multiple hypothalamic-pituitary functions assessment in patients with Turner's syndrome

Hypothalamic-pituitary functions in 26 cases of Turner syndrome were assessed with a combined stimulation test. The results showed that the peak GH levels of 12 cases were less than 10 micrograms/L; 3 patients were demonstrated as having an even TSH response, while another one with a delayed TSH peak, and other 4 had high basal values and consistent exaggerated TSH responses to TRH; all patients showed increased basal and peak LH and FSH levels but 5, whose LH and FSH secretion patterns were similar to normal. 12 cases have been treated with individualized protocols and followed up for 12 months or more, of them the growth velocity all increased, especially those with hypothyroidism or with a BA less than 13. It is suggested that multiple functions of hypothalamic-pituitary axis in Turner patients be evaluated as early as possible, in order that proper treatment could be adopted and their growth and development improved.

Excess cancer mortality among children and adolescents in residential districts polluted by petrochemical manufacturing plants in Taiwan

We have collected data on the cancer deaths of children and adolescents 0-19 yr old living in a residential area near 3 large petroleum and petrochemical complexes in and near Kaohsiung city (petrochemical industrial districts, PIDs) in the period of 1971-1990 and compared these with the cancer deaths of children and adolescents 0-19 yr old among the entire population of Taiwan (national reference) and among the residents of 26 administrative districts, comprising all of Kaohsiung city and Kaohsiung county (local reference), except for 8 sparsely populated, rural districts. Having scrutinized all cancer death certificates, we have identified various statistically significant excess deaths, as compared with the national and local reference, due to cancers at all sites. Cancer of the bone, brain, and bladder in boys and girls 0-9 yr and 10-19 yr of age in the 1981-1990 decade that followed the establishment of petrochemical production in the PIDs was studied. However, excess cancer deaths seemed to have clustered in the 10-19 yr age group, who had been potentially exposed to the petrochemical pollutants for the longest period of time from the youngest age. Almost all bone, brain, and bladder cancer deaths registered were within 3 km of the 3 complexes. Bone and brain cancers in particular occurred in girls in the PIDs more frequently than in boys, even though these are believed to occur more in males than females elsewhere.

Development of 124 sequence-tagged sites and cytogenetic localization of 217 cosmids for human chromosome 10

A total of 124 new chromosome 10-specific sequence-tagged sites (STSs) were derived from two sources: (1) DNA sequences obtained from anonymous clones in new libraries enriched for human chromosome 10 inserts, and (2) published sequences of genes and other loci already known to map to chromosome 10. Libraries were constructed from a somatic cell hybrid carrying human chromosomes 10 and Y. A cosmid library was made from total DNA of the hybrid and probed with labeled total human DNA to identify clones with human DNA inserts. Two hundred seventeen cosmids were mapped to regions of human chromosome 10 by fluorescence in situ hybridization. Twenty-five cosmids represent probes that have been placed on the genetic map previously. One hundred ninety-two cosmids represent new probes that have not been mapped previously. Cosmids carrying inserts with CA repeats were identified by hybridization with a labeled poly(dC-dA)-poly(dG-dT) probe and subcloned to yield microsatellite STS markers. Two small insert plasmid libraries were made, the first by subcloning inserts from a chromosome 10-enriched lambda phage library (LL10NS01) and the second by cloning Alu element-mediated PCR products amplified from hybrid DNA. STSs were generated from the DNA sequences of clone inserts. Chromosome 10-specific STSs were distinguished from Y chromosome STSs by one or both of the following criteria: (1) successful PCR amplification from a template consisting of DNA from another chromosome 10-containing cell line, NA10926B, or (2) FISH localization to chromosome 10 of the source cosmid or of YACs isolated by PCR screening with the STS. These libraries were the source of 90 new chromosome 10-specific STSs, 42 of which contain CA repeats.

Toward a physical map of human chromosome 10: isolation of 183 YACs representing 80 loci and regional assignment of 94 YACs by fluorescence in situ hybridization

One hundred eighty-three YACs carrying human chromosome 10 sequences were isolated from multigenome equivalent libraries by PCR-based screening for the presence of 80 different chromosome 10-specific STSs. Ninety-four of the isolated YACs, representing 52 genes and DNA segments, were mapped to regions of chromosome 10 by fluorescence in situ hybridization. The results localized 26 DNA segments to cytogenetic bands for the first time. About 37% (35/94) of the YACs hybridized to more than one chromosomal location: 31 to other chromosomes in addition to chromosome 10 and 4 to 2 distinct locations on chromosome 10. These results are consistent with the number of chimeric YACs expected from these libraries but may also reflect the presence of 2 or more YACs within a single clone or the presence of low copy repeated elements within the genome. This STS anchor screening effort resulted in the identification of 69 contigs, with 7 contigs consisting of 2 anchors each and 1 contig consisting of 5 anchors. All linked STSs were multiply linked by at least 2 independent YACs. These anchored YACs span the entire chromosome and appear to cover 15% of chromosome 10.

Study on blackfoot disease: with special reference to evaluating its cutaneous microcirculatory status

We evaluated the microcirculatory status of blackfoot disease by skin temperature measurement, laser Doppler flowmetry and capillary microscopy. The results of these assessments revealed a good correlation between the disease stage and the microcirculatory status. No effective therapy other than surgical amputation was recommended before. In this study, we treated this endemic disease with prostaglandin E1 (PGE1) infusion therapy. PGE1 was most effective in the erythematous stage and some minor ulcer with an improvement of microcirculatory status. However, PGE1 had no effect in severe ulcerative (ulcer > 0.5 cm) and gangrenous stages. These microcirculatory improvements foreshadowed the improvement of clinical manifestations. The microcirculatory status after PGE1 treatment demonstrated the effectiveness of the therapy.

Detection of dengue virus antigens in cultured cells by using protein A-gold-silver staining (pAgs) method

A protein A-gold-silver (pAgs) staining was developed to detect dengue virus antigens in cultured cells. The method can be carried out in either newly-subcultured or monolayered cells. Dengue virus-inoculated C6/36 clone of Aedes albopictus cells and human endothelial cells appeared brown-yellowish color on the peripheral membrane of the infected cells. In many cases, the infected C6/36 cells appeared darker than that of the infected endothelial cells. The positive results from the inoculated C6/36 cells usually appeared as early as 2 days post-inoculation for types 1, 2, and 4 of dengue viruses and 3 days for the dengue 3 virus. The same batch of specimens detected by direct immunofluorescence antibody test (DFA) showed positive 4 days post-inoculation for the types 2, 3, and 4 of dengue viruses and 6 days for the dengue 1 virus. The result also showed that all pAgs-positive specimens were also DFA-positive, but not vice versa. It suggested that pAgs is not only sensitive but also specific for dengue virus detection from inoculated cultured cells.

Continuous infusion of cefazolin is superior to intermittent dosing in decreasing infection after hemorrhagic shock

Standard doses of antibiotic administered by intermittent infusions after hemorrhagic shock have decreased efficacy in combating infection. This study compared identical quantities of cefazolin administered after shock as intermittent doses or as continuous infusions in a subcutaneous abscess model. One hour after resuscitation from shock, rats were inoculated with 2 x 10(8) Staphylococcus aureus subcutaneously on the dorsum and divided into three groups: (1) control rats, which received no drug treatment; (2) rats in the intermittent group, which received cefazolin at either 30 or 60 mg/kg intraperitoneally, 30 minutes prior to inoculation, then every 8 hours for three doses, and (3) rats in the continuous infusion group, which received cefazolin at either 30 or 60 mg/kg intraperitoneally, 30 minutes prior to inoculation, followed by cefazolin, 90 or 180 mg/kg, intraperitoneally by continuous infusion more than 24 hours after inoculation. Seven days after the inoculation, abscess number, diameter, and weight were measured. Rats that received either dosage of cefazolin intermittently had the same abscess rate after shock as control rats. Rats that received a continuous infusion of cefazolin at either dose had 56% fewer abscesses than control rats. Abscess diameter and weight decreased with increasing quantities of cefazolin, and abscesses were always smaller in rats receiving the continuous infusion. There were no differences in peak subcutaneous cefazolin levels between the intermittent and continuous groups. Continuous infusion provided significantly more cefazolin to the tissue than an equivalent quantity of cefazolin delivered as intermittent doses. These data demonstrate that continuous infusion of cefazolin provided more antibiotic to the tissue and was superior to intermittent injection in reducing infection after hemorrhagic shock.

Hypothalamic-pituitary function assessment in children by a combined stimulation test

We utilized a combined stimulation test using insulin, thyrotropin-releasing hormone, gonadotropin-releasing hormone and levodopa to assess multiple pituitary hormones including growth hormone, thyrotropin, prolactin and gonadotropins in 32 children of short stature and 18 girls with early appearance of puberty. It was found that this combined stimulation test can assess multiple hormone responses with satisfactory results in a single 90-min test. Compared with any of those laborious classic stimulation tests alone, it is easier to be carried out and willingly accepted by children.

Hemorrhagic shock inhibits lipopolysaccharide-induced myelopoiesis in both germ-free and conventional rats

BACKGROUND

Bacterial translocation has been implicated in the alteration of the immune response after shock and trauma. This study examined the effect of bacterial translocation on myelopoiesis after hemorrhagic shock in germ-free and conventional rats.

METHODS

Awake, unrestrained germ-free and conventional rats were bled to a mean arterial pressure of 30 mm Hg until the animal required infusion of 10% of the shed blood. Rats were resuscitated with shed blood and crystalloid. Sham rats were catheterized but not bled. Twenty-four hours after shock or sham, rats were administered lipopolysaccharide 100 micrograms or saline intraperitoneally. Twenty-four hours later, bone marrow cells were cultured for growth of granulocyte-macrophage colony-stimulating factor (CFU-GM).

RESULTS

Lipopolysaccharide increased the number of CFU-GM/femur in sham germ-free rats (801 +/- 129 versus 455 +/- 110; p less than 0.05) and conventional rats (1458 +/- 200 versus 492 +/- 59; p less than 0.05) compared with saline-treated rats. In contrast, hemorrhagic shock inhibited lipopolysaccharide-induced CFU-GM growth in both germ-free and conventional rats. Shock, itself, was a stimulus for CFU-GM growth in germ-free but not conventional rats. Bone marrow white blood cell counts were unaffected by shock, lipopolysaccharide administration, or the germ-free state.

CONCLUSIONS

Hemorrhagic shock inhibited lipopolysaccharide-induced CFU-GM proliferation independent of the germ-bearing status of the rat, and bacterial translocation exerted no influence on myelopoietic dysfunction after hemorrhagic shock.

The screening diagnosis of tetrahydrobiopterin deficient phenylketonuria

Since 1990, 20 diagnostically confirmed phenylketonuria (PKU) patients have been screened with a tetrahydrobiopterin (BH4) loading test, in which plasma phenylalanine and urinary pterin metabolites were investigated, ind activity of dihydropteridine reductase (DHPR) was determined as well. The results showed that there was no statistical difference between the concentrations of plasma phenylalanine before and after BH4 (20mg/kg) administration in all patients, and values of urinary neopterin and biopterin were within the range of classic PKU. All patients but one had normal activity of DHPR in red cells. This suggests that incidence of BH4 deficiency in PKU patients amounts to five percent (1/20) which is almost the same as reported abroad.

Regulation of the cytoplasmic accumulation of 5-methyltetrahydrofolate in MA104 cells is independent of folate receptor regulation

To better understand how the folate receptor (also known as the membrane folate binder) is able to deliver 5-methyltetrahydrofolic acid to the cytoplasm of folate-depleted MA104 cells, we have examined the kinetics of movement from the cell surface into the cytoplasm. Bound 5-methyltetrahydrofolic acid was transferred into an acid-resistant membrane compartment at the rate of 0.9-1.0 pmol/10(6) cells per h. This folate appeared in the cytoplasm at the same rate. Furthermore, cytoplasmic 5-methyltetrahydrofolic acid became polyglutamated at the rate of 0.6-0.7 pmol/10(6) cells per h. As soon as intracellular 5-methyltetrahydrofolate reached 5-7 pmol/10(6) cells, however, cytoplasmic accumulation was markedly inhibited even though the folate receptor remained functional. Therefore, the acute regulation of 5-methyltetrahydrofolic acid accumulation appears to be achieved by controlling the movement of the vitamin from the receptor into the cytoplasm of the cell.