316 research outputs found
Mapping of neurokinin b in the cat brainstem
Abstract We studied the distribution of neurokinin B-immunoreactive cell bodies and fibers in the cat brainstem using an indirect immunoperoxidase technique. The highest density of immunoreactive fibers was found in the motor trigeminal nucleus, the laminar and alaminar spinal trigeminal nuclei, the facial nucleus, the marginal nucleus of the brachium conjunctivum, the locus coeruleus, the cuneiform nucleus, the dorsal motor nucleus of the vagus, the postpyramidal nucleus of the raphe, the lateral tegmental field, the Ko¨lliker-Fuse nucleus, the inferior central nucleus, the periaqueductal gray, the nucleus of the solitary tract, and in the inferior vestibular nucleus. Immunoreactive cell bodies containing neurokinin B were observed, for example, in the locus coeruleus, the dorsal motor nucleus of the vagus, the median division of the dorsal nucleus of the raphe, the lateral tegmental field, the pericentral nucleus of the inferior colliculus, the internal division of the lateral reticular nucleus, the inferior central nucleus, the periaqueductal gray, the postpyramidal nucleus of the raphe, and in the medial nucleus of the solitary tract. This widespread distribution of neurokinin B in the cat brainstem suggests that the neuropeptide could be involved in many different physiological functions. In comparison with previous studies carried out in the rat brainstem on the distribution of neurokinin B, our results point to a more widespread distribution of this neuropeptide in the cat brainstem. Keywords Neurokinin B AE Brainstem AE Cat AE Immunocytochemistry AE Mapping AE Tachykini
Intra-anal imiquimod cream against human papillomavirus infection in men who have sex with men living with hiv: A single-arm, open-label pilot study
Men who have sex with men (MSM) living with HIV have a high prevalence and incidence of anal high-risk human papillomavirus (hrHPV) and anal cancer. We conducted an open-label, single-arm pilot study to examine the tolerability of imiquimod cream among MSM aged ≥18 years, living with HIV, who tested positive for anal hrHPV at Melbourne Sexual Health Centre between April 2018 and June 2020. We instructed men to apply 6.25 mg imiquimod intra-anally and peri-anally 3 doses per week for 16 weeks (period 1) and then one dose per week for a further 48 weeks (period 2). Twenty-seven MSM enrolled in period 1 and 24 (86%) applied at least 50% of doses. All men reported adverse events (AEs), including 39.5% grade 1, 39.5% grade 2, and 21% grade 3 AEs on at least one occasion. Eighteen MSM (67%) temporarily stopped using imiquimod during period 1, most commonly due to local AEs (n = 11) such as irritation and itching. Eighteen MSM continued in period 2 and all applied at least 50% of doses with no treatment-limiting AEs reported. Imiquimod 3 doses per week caused local AEs in most men and was not well tolerated. In contrast, once-a-week application was well tolerated over 48-weeks with no treatment-limiting AEs
Stemness of the Organ of Corti Relates to the Epigenetic Status of Sox2 Enhancers
In the adult mammalian auditory epithelium, the organ of Corti, loss of sensory hair cells results in permanent hearing loss. The underlying cause for the lack of regenerative response is the depletion of otic progenitors in the cell pool of the sensory epithelium. Here, we show that an increase in the sequence-specific methylation of the otic Sox2 enhancers NOP1 and NOP2 is correlated with a reduced self-renewal potential in vivo and in vitro; additionally, the degree of methylation of NOP1 and NOP2 is correlated with the dedifferentiation potential of postmitotic supporting cells into otic stem cells. Thus, the stemness the organ of Corti is related to the epigenetic status of the otic Sox2 enhancers. These observations validate the continued exploration of treatment strategies for dedifferentiating or reprogramming of differentiated supporting cells into progenitors to regenerate the damaged organ of Corti
Genomic Profiling Identifies GATA6 as a Candidate Oncogene Amplified in Pancreatobiliary Cancer
Pancreatobiliary cancers have among the highest mortality rates of any cancer type. Discovering the full spectrum of molecular genetic alterations may suggest new avenues for therapy. To catalogue genomic alterations, we carried out array-based genomic profiling of 31 exocrine pancreatic cancers and 6 distal bile duct cancers, expanded as xenografts to enrich the tumor cell fraction. We identified numerous focal DNA amplifications and deletions, including in 19% of pancreatobiliary cases gain at cytoband 18q11.2, a locus uncommonly amplified in other tumor types. The smallest shared amplification at 18q11.2 included GATA6, a transcriptional regulator previously linked to normal pancreas development. When amplified, GATA6 was overexpressed at both the mRNA and protein levels, and strong immunostaining was observed in 25 of 54 (46%) primary pancreatic cancers compared to 0 of 33 normal pancreas specimens surveyed. GATA6 expression in xenografts was associated with specific microarray gene-expression patterns, enriched for GATA binding sites and mitochondrial oxidative phosphorylation activity. siRNA mediated knockdown of GATA6 in pancreatic cancer cell lines with amplification led to reduced cell proliferation, cell cycle progression, and colony formation. Our findings indicate that GATA6 amplification and overexpression contribute to the oncogenic phenotypes of pancreatic cancer cells, and identify GATA6 as a candidate lineage-specific oncogene in pancreatobiliary cancer, with implications for novel treatment strategies
Indirect Effects of Wnt3a/β-Catenin Signalling Support Mouse Spermatogonial Stem Cells In Vitro
Proper regulation of spermatogonial stem cells (SSCs) is crucial for sustaining steady-state spermatogenesis. Previous work has identified several paracrine factors involved in this regulation, in particular, glial cell line-derived neurotrophic factor and fibroblast growth factor 2, which promote long-term SSC self-renewal. Using a SSC culture system, we have recently reported that Wnt5a promotes SSC self-renewal through a β-catenin-independent Wnt mechanism whereas the β-catenin-dependent Wnt pathway is not active in SSCs. In contrast, another study has reported that Wnt3a promotes SSC self-renewal through the β-catenin-dependent pathway, as it can stimulate the proliferation of a spermatogonia cell line. To reconcile these two contradictory reports, we assessed Wnt3a effects on SSCs and progenitor cells, rather than a cell line, in vitro. We observed that Wnt3a induced β-catenin-dependent signalling in a large subset of germ cells and increased SSC numbers. However, further investigation revealed that cell populations with greater β-catenin-signalling activity contained fewer SSCs. The increased maintenance of SSCs by Wnt3a coincided with more active cell cycling and the formation of germ cell aggregates, or communities, under feeder-free conditions. Therefore, the results of this study suggest that Wnt3a selectively stimulates proliferation of progenitors that are committed to differentiation or are in the process of exiting the SSC state, leading to enhanced formation of germ cell communities, which indirectly support SSCs and act as an in vitro niche
Downregulation of urokinase plasminogen activator receptor expression inhibits Erk signalling with concomitant suppression of invasiveness due to loss of uPAR–β1 integrin complex in colon cancer cells
Cancer invasion is regulated by cell surface proteinases and adhesion molecules. Interaction between specific cell surface molecules such as urokinase plasminogen activator receptor (uPAR) and integrins is crucial for tumour invasion and metastasis. In this study, we examined whether uPAR and beta1 integrin form a functional complex to mediate signalling required for tumour invasion. We assessed the expression of uPAR/beta1 integrin complex, Erk signalling pathway, adhesion, uPA and matrix metalloproteinase (MMP) expression, migration/invasion and matrix degradation in a colon cancer cell line in which uPAR expression was modified. Antisense inhibition of the cell surface expression of uPAR by 50% in human colon carcinoma HCT116 cells (A/S) suppressed Erk-MAP kinase activity by two-fold. Urokinase plasminogen activator receptor antisense treatment of HCT116 cells was associated with a 1.3-fold inhibition of adhesion, approximately four-fold suppression of HMW-uPA secretion and inhibition of pro-MMP-9 secretion. At a functional level, uPAR antisense resulted in a four-fold decline in migration/invasion and abatement of plasmin-mediated matrix degradation. In empty vector-transfected cells (mock), uPA strongly elevated basal Erk activation. In contrast, in A/S cells, uPA induction of Erk activation was not observed. Urokinase plasminogen activator receptor associated with beta1 integrin in mock-transfected cells. Disruption of uPAR-beta1 integrin complex in mock-transfected cells with a specific peptide (P25) inhibited uPA-mediated Erk-MAP kinase pathway and inhibited migration/invasion and plasmin-dependent matrix degradation through suppression of pro-MMP-9/MMP-2 expression. This novel paradigm of uPAR-integrin signalling may afford opportunities for alternative therapeutic strategies for the treatment of cancer
Effects of body weight and alcohol consumption on insulin sensitivity
<p>Abstract</p> <p>Background</p> <p>Obesity is a risk factor for the development of insulin resistance, which can eventually lead to type-2 diabetes. Alcohol consumption is a protective factor against insulin resistance, and thus protects against the development of type-2 diabetes. The mechanism by which alcohol protects against the development of type-2 diabetes is not well known. To determine the mechanism by which alcohol improves insulin sensitivity, we fed water or alcohol to lean, control, and obese mice. The aim of this study was to determine whether alcohol consumption and body weights affect overlapping metabolic pathways and to identify specific target genes that are regulated in these pathways.</p> <p>Method</p> <p>Adipose tissue dysfunction has been associated with the development of type-2 diabetes. We assessed possible gene expression alterations in epididymal white adipose tissue (WAT). We obtained WAT from mice fed a calorie restricted (CR), low fat (LF Control) or high fat (HF) diets and either water or 20% ethanol in the drinking water. We screened the expression of genes related to the regulation of energy homeostasis and insulin regulation using a gene array composed of 384 genes.</p> <p>Results</p> <p>Obesity induced insulin resistance and calorie restriction and alcohol improved insulin sensitivity. The insulin resistance in obese mice was associated with the increased expression of inflammatory markers Cd68, Il-6 and Il-1α; in contrast, most of these genes were down-regulated in CR mice. Anti-inflammatory factors such as Il-10 and adrenergic beta receptor kinase 1 (Adrbk1) were decreased in obese mice and increased by CR and alcohol. Also, we report a direct correlation between body weight and the expression of the following genes: Kcnj11 (potassium inwardly-rectifying channel, subfamily J, member 11), Lpin2 (lipin2), and Dusp9 (dual-specificity MAP kinase phosphatase 9).</p> <p>Conclusion</p> <p>We show that alcohol consumption increased insulin sensitivity. Additionally, alterations in insulin sensitivity related with obesity were coupled with alterations in inflammatory genes. We provide evidence that alcohol may improve insulin sensitivity by up-regulating anti-inflammatory genes. Moreover, we have indentified potential gene targets in energy metabolic pathways and signal transducers that may contribute to obesity-related insulin resistance as well as calorie restriction and alcohol-induced insulin sensitivity.</p
Vandetanib (ZD6474), an inhibitor of VEGFR and EGFR signalling, as a novel molecular-targeted therapy against cholangiocarcinoma
Cholangiocarcinoma is an intractable cancer, with no effective therapy other than surgical resection. Elevated vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) expressions are associated with the progression of cholangiocarcinoma. We therefore examined whether inhibition of VEGFR and EGFR could be a potential therapeutic target for cholangiocarcinoma. Vandetanib (ZD6474, ZACTIMA), a VEGFR-2/EGFR inhibitor, was evaluated. Four human cholangiocarcinoma cell lines were molecularly characterised and investigated for their response to vandetanib. In vitro, two cell lines (OZ and HuCCT1), both of which harboured KRAS mutation, were refractory to vandetanib, one cell line (TGBC24TKB) was somewhat resistant, and another cell line (TKKK) was sensitive. The most sensitive cell line (TKKK) had EGFR amplification. Vandetanib significantly inhibited the growth of TKKK xenografts at doses ⩾12.5 mg kg−1 day−1 (P<0.05), but higher doses (50 mg kg−1 day−1, P<0.05) of vandetanib were required to inhibit the growth of OZ xenografts. Vandetanib (25 mg kg−1 day−1) also significantly (P=0.006) prolonged the time to metastasis in an intravenous model of TKKK metastasis. Inhibiting both VEGFR and EGFR signalling appears a promising therapeutic approach for cholangiocarcinoma. The absence of KRAS mutation and the presence of EGFR amplification may be potential predictive molecular marker of sensitivity to EGFR-targeted therapy in cholangiocarcinoma
Gene expression profile of circulating tumor cells in breast cancer by RT-qPCR
<p>Abstract</p> <p>Background</p> <p>Circulating tumor cells (CTCs) have been associated with prognosis especially in breast cancer and have been proposed as a liquid biopsy for repeated follow up examinations. Molecular characterization of CTCs is difficult to address since they are very rare and the amount of available sample is very limited.</p> <p>Methods</p> <p>We quantified by RT-qPCR <it>CK-19, MAGE-A3, HER-2, TWIST1, hTERT α+β+</it>, and <it>mammaglobin </it>gene transcripts in immunomagnetically positively selected CTCs from 92 breast cancer patients, and 28 healthy individuals. We also compared our results with the CellSearch system in 33 of these patients with early breast cancer.</p> <p>Results</p> <p>RT-qPCR is highly sensitive and specific and can detect the expression of each individual gene at the one cell level. None of the genes tested was detected in the group of healthy donors. In 66 operable breast cancer patients, <it>CK-19 </it>was detected in 42.4%, <it>HER-2 </it>in 13.6%, <it>MAGE-A3 </it>in 21.2%, <it>hMAM </it>in 13.6%, <it>TWIST-1 </it>in 42.4%, and <it>hTERT α+β+ </it>in 10.2%. In 26 patients with verified metastasis, <it>CK-19 </it>was detected in 53.8%, <it>HER-2 </it>in 19.2%, <it>MAGE-A3 </it>in 15.4%, <it>hMAM </it>in 30.8%, <it>TWIST-1 </it>in 38.5% and <it>hTERT </it>α<sup>+</sup>β<sup>+</sup>in 19.2%. Our preliminary data on the comparison between RT-qPCR and CellSearch in 33 early breast cancer patients showed that RT-qPCR gives more positive results in respect to CellSearch.</p> <p>Conclusions</p> <p>Molecular characterization of CTCs has revealed a remarkable heterogeneity of gene expression between breast cancer patients. In a small percentage of patients, CTCs were positive for all six genes tested, while in some patients only one of these genes was expressed. The clinical significance of these findings in early breast cancer remains to be elucidated when the clinical outcome for these patients is known.</p
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