Am J Physiol Regul Integr Comp Physiol
May 2008
Unlike calorie restriction, exercise fails to extend maximum life span, but the mechanisms that explain this disparate effect are unknown. We used a 24-wk protocol of treadmill running, weight matching, and pair feeding to compare the effects of exercise and calorie restriction on biomarkers related to aging. This study consisted of young controls, an ad libitum-fed sedentary group, two groups that were weight matched by exercise or 9% calorie restriction, and two groups that were weight matched by 9% calorie restriction + exercise or 18% calorie restriction.
View Article and Find Full Text PDFLamprey and hagfish, the living representatives of jawless vertebrates, use genomic leucine-rich-repeat cassettes for the combinatorial assembly of diverse antigen receptor genes encoding variable lymphocyte receptors of two types: VLRA and VLRB. We describe here the VLRB-bearing lineage of lymphocytes in sea lamprey. These cells responded to repetitive carbohydrate or protein determinants on bacteria or mammalian cells with lymphoblastoid transformation, proliferation and differentiation into plasmacytes that secreted multimeric antigen-specific VLRB antibodies.
View Article and Find Full Text PDFObjectives: To investigate the cytotoxicity of TRA-8, an antibody that specifically binds death receptor 5 (DR5), alone and in combination with cisplatin, using an ex vivo human cervical cancer model.
Methods: Fifteen cervical cancer specimens were obtained at the time of radical hysterectomy and tumor slices were prepared with the Krumdieck tissue slicer. Tumor slices were exposed to varying concentrations of TRA-8, cisplatin, or the combination of TRA-8 and cisplatin.
Tissue resources have become an important component of the infrastructure of institutions as well as companies performing biomedical research. Such tissue resources may be in the model of a bank, collecting a limited type of tissues and processing and storing them following a specific protocol. Such banks or archives may be associated with a clinical study or may function indepedently.
View Article and Find Full Text PDFWe have isolated cDNAs encoding PDE4A8 (phosphodiesterase 4 isoform A8), a new human cAMP-specific PDE4 isoform encoded by the PDE4A gene. PDE4A8 has a novel N-terminal region of 85 amino acids that differs from those of the related 'long' PDE4A4, PDE4A10 and PDE4A11 isoforms. The human PDE4A8 N-terminal region has diverged substantially from the corresponding isoforms in the rat and other mammals, consistent with rapid evolutionary change in this region of the protein.
View Article and Find Full Text PDFPurpose: To evaluate agonistic TRA-8 monoclonal antibody to human death receptor 5 (DR5) and gemcitabine in vitro and in an orthotopic pancreatic cancer model.
Experimental Design: Pancreatic cancer cell lines were screened for DR5 expression, cytotoxicity, and apoptosis induced by TRA-8, gemcitabine, or gemcitabine and TRA-8. An orthotopic model of pancreatic cancer was established in severe combined immunodeficient mice.
For subsets of colorectal adenocarcinoma (CRC) patients, nuclear accumulation of p53 (p53(nac)) and Bcl-2 expression are prognostic indicators. To understand their role in the progression of CRC we evaluated 90 CRCs and their contiguous adenomatous components (CAdCs) for immunohistochemical expression of these markers. In general, p53(nac) and Bcl-2 expression was significantly increased when comparing normal colonic epithelia to CAdCs and CRCs.
View Article and Find Full Text PDFObjective: The objective of this study was to evaluate whether mandatory fortification of grain products with folic acid in the United States is associated with changes in DNA methyltransferase-1 (Dnmt-1) expression in cells involved in cervical carcinogenesis.
Methods: Archived specimens of cervical intraepithelial neoplasia (CIN) diagnosed before (1990-1992) and after (2000-2002) mandatory folic acid fortification were used to examine the expression of Dnmt-1 in specific lesions involved in cervical carcinogenesis by immunohistochemistry. The total number of lesions examined was 101 in the prefortification period and 96 in the postfortification period.
Over the past four decades in the United States, there has been a divergent trend in mortality rates between African-Americans and Caucasians with colorectal cancer (CRC). Rates among Caucasians have been steadily declining, whereas rates among African-Americans have only started a gradual decline in recent years. We reviewed epidemiologic studies of CRC racial disparities between African-Americans and Caucasians, including studies from SEER and population-based cancer registries, Veterans Affairs (VA) databases, healthcare coverage databases, and university and other medical center data sources.
View Article and Find Full Text PDFRecent studies suggest that hedgehog (HH)-pathway signaling is required for the initiation and continued growth of pancreatic adenocarcinoma (PAC). Definitive gene expression analysis of PAC remains difficult, owing to the host desmoplastic stromal interaction and subsequent tumor heterogeneity. The primary goal of this study was to evaluate the effect of heterogeneity within a series (n=5) of matched clinical PAC biopsies [snap-frozen, formalin-fixed paraffin-embedded (FPE), endoscopic ultrasound-guided fine-needle aspirate (EUS-FNA)].
View Article and Find Full Text PDFIn this study, our data show that in young BXD12 mice, the implanted TS/A tumor regressed in 4 weeks after implantation, and this regression was associated with extensive T cell infiltration. In contrast, in old BXD12 mice, it was observed that there was rapid tumor growth by 7 weeks. T cell cytotoxicity against TS/A tumor cells exhibited a significant age-related decline, which was correlated with a decline in CD3(+) T cell infiltration of the tumor.
View Article and Find Full Text PDFBackground: The analysis of bodily fluids using SELDI-TOF MS has been reported to identify signatures of spectral peaks that can be used to differentiate patients with a specific disease from normal or control patients. This report is the 2nd of 2 companion articles describing a validation study of a SELDI-TOF MS approach with IMAC surface sample processing to identify prostatic adenocarcinoma.
Methods: We sought to derive a decision algorithm for classification of prostate cancer from SELDI-TOF MS spectral data from a new retrospective sample cohort of 400 specimens.
LIM kinases (LIMK1 and LIMK2) are LIM domain containing serine/threonine kinases that modulate reorganization of actin cytoskeleton through inactivating phosphorylation of cofilin. The Rho family of small GTPases regulates the catalytic activity of LIMK1 and LIMK2 through activating phosphorylation by ROCK or by p21 kinase. Recent studies have suggested that LIMK1 could play a role in modulation of cellular growth by alteration of the cell cycle in breast and prostate tumor cells; however, the direct mitogenic effects of LIMK1 in these tumor cells is yet to be elucidated.
View Article and Find Full Text PDFBackground: This report and a companion report describe a validation of the ability of serum proteomic profiling via SELDI-TOF mass spectrometry to detect prostatic cancer. Details of this 3-stage process have been described. This report describes the development of the algorithm and results of the blinded test for stage 1.
View Article and Find Full Text PDFThe recently identified human ortholog of the Rabphillin-3A-Like (RPH3AL) gene, located at the 17p13.3 locus, has been assessed for its mutational status and clinical significance in colorectal adenocarcinoma (CRC). Prospectively collected 95 frozen CRCs and their matching benign colonic epithelial tissues were evaluated for mutations and mRNA expression.
View Article and Find Full Text PDFObjectives: Sestamibi scans for localization of abnormal parathyroid glands in patients with hyperparathyroidism are widely used at many institutions. Minimally invasive parathyroid surgery demands accurate preoperative localization imaging; however, nonlocalizing sestamibi scans occur in 15% of patients with primary hyperparathyroidism. It remains unknown why some sestamibi scans fail to localize.
View Article and Find Full Text PDFPancreatic cancer is highly resistant to current chemotherapy agents. We therefore examined the effects of triptolide (a diterpenoid triepoxide) on pancreatic cancer growth and local-regional tumor spread using an orthotopic model of pancreatic cancer. We have recently shown that an increased level of HSP70 in pancreatic cancer cells confers resistance to apoptosis and that inhibiting HSP70 induces apoptosis in these cells.
View Article and Find Full Text PDFPurpose: Evaluate the response of human pancreatic cancer cell lines and orthotopic tumors to TRA-8, an agonistic antibody to death receptor 5, in combination with irinotecan (CPT-11).
Experimental Design: MIA PaCa-2 and S2VP10 cells were treated with TRA-8 and/or CPT 11. Cell viability was determined by ATP assay.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human malignancies, with an overall 5-year survival rate of <5%. Genetic analysis of PDAC patient samples has shown that specific disease-associated mutations are correlated with histologically defined stages of neoplastic progression in the ductal epithelium. Activating mutations in KRAS are almost uniformly present in early-stage disease, with subsequent inactivating mutations in p16(INK4A), p53, and SMAD4 occurring in more advanced lesions.
View Article and Find Full Text PDFEvidence suggests that the histone deacetylase, SIRT1, is a mediator of life span extension by calorie restriction; however, SIRT1 may paradoxically increase the risk of cancer. To better understand the relationship among SIRT1, energy balance, and cancer, two experiments were done. First, a transgenic mouse model of prostate cancer (transgenic adenocarcinoma of mouse prostate; TRAMP) was used to determine the role of energy balance on SIRT1 expression and the effect of cancer stage on SIRT1 and hypermethylated in cancer-1 (HIC-1).
View Article and Find Full Text PDFBackground: LIM kinase 1 (LIMK1), a LIM domain containing serine/threonine kinase, modulates actin dynamics through inactivation of the actin depolymerizing protein cofilin. Recent studies have indicated an important role of LIMK1 in growth and invasion of prostate and breast cancer cells; however, the molecular mechanism whereby LIMK1 induces tumor progression is unknown. In this study, we investigated the effects of ectopic expression of LIMK1 on cellular morphology, cell cycle progression and expression profile of LIMK1 in prostate tumors.
View Article and Find Full Text PDFAn important characteristic of tumors is that they at some point in their development overcome the surveillance of the immune system. Tumors secrete exosomes, multivesicular bodies containing a distinct set of proteins that can fuse with cells of the circulating immune system. Purified exosomes from TS/A breast cancer cells, but not non-exosomal fractions, inhibit (at concentrations of nanograms per ml protein) IL-2-induced natural killer (NK) cell cytotoxicity.
View Article and Find Full Text PDFThe production of exosomes by tumor cells has been implicated in tumor-associated immune suppression. In this study, we show that, in mice, exosomes produced by TS/A murine mammary tumor cells target CD11b(+) myeloid precursors in the bone marrow (BM) in vivo, and that this is associated with an accumulation of myeloid precursors in the spleen. Moreover, we demonstrate that TS/A exosomes block the differentiation of murine myeloid precursor cells into dendritic cells (DC) in vitro.
View Article and Find Full Text PDFDefective receptor editing or defective B cell checkpoints have been associated with increased frequency of multireactive autoantibodies in autoimmune disease. However, Ig somatic hypermutation and/or class switch recombination may be mechanisms enabling the development of pathogenic multireactive autoantibodies. In this study, we report that, in the BXD2 mouse model of autoimmune disease, elevated expression of activation-induced cytidine deaminase (AID) in recirculating follicular CD86(+) subsets of B cells and increased germinal center B cell activity are associated with the production of pathogenic multireactive autoantibodies.
View Article and Find Full Text PDF