MUC1 and HIF-1alpha Signaling Crosstalk Induces Anabolic Glucose Metabolism to Impart Gemcitabine Resistance to Pancreatic Cancer

Poor response to cancer therapy due to resistance remains a clinical challenge. The present study establishes a widely prevalent mechanism of resistance to gemcitabine in pancreatic cancer, whereby increased glycolytic flux leads to glucose addiction in cancer cells and a corresponding increase in pyrimidine biosynthesis to enhance the intrinsic levels of deoxycytidine triphosphate (dCTP). Increased levels of dCTP diminish the effective levels of gemcitabine through molecular competition. We also demonstrate that MUC1-regulated stabilization of hypoxia inducible factor-1α (HIF-1α) mediates such metabolic reprogramming. Targeting HIF-1α or de novo pyrimidine biosynthesis, in combination with gemcitabine, strongly diminishes tumor burden. Finally, reduced expression of TKT and CTPS, which regulate flux into pyrimidine biosynthesis, correlates with better prognosis in pancreatic cancer patients on fluoropyrimidine analogs.

Effects of estrogens and progestins on the biochemistry and morphology of the postmenopausal endometrium

To study the effects of exogenous estrogens on the postmenopausal endometrium, and to determine the time course and minimum dosage of added progestins necessary to oppose estrogen stimulation, we obtained endometrial specimens from symptomatic postmenopausal women being treated with various preparations of estrogens and progestins. Morphologic changes were assessed with light and electron microscopy, and biochemical effects through measurement of DNA synthesis, estradiol and progesterone receptors, and isocitric and estradiol dehydrogenase activity. For comparison, identical studies were carried out on specimens from premenopausal women in the proliferative and secretory phases of their cycle. All the estrogens exerted stimulatory effects in the postmenopausal specimens that were comparable to those observed in the premenopausal proliferative-phase specimens. Estropipate, subcutaneous estradiol, and conjugated estrogens had some hyperphysiologic effects. Maximal progestational effects occurred in the postmenopausal specimens only after norethindrone was administered for six days, and a constant level of activity equal to that in premenopausal secretory-phase specimens was then observed until the 10th day of exposure. Similar maximal effects occurred after six days of treatment with D/L-norgestrel (150 and 5 mg daily [10 mg daily produced less complete changes]). We conclude that many estrogen preparations subject the endometrium to a potent stimulus. Norethindrone and norgestrel are protective because they counteract the proliferative effects of estrogens, but the currently recommended daily dosages of these progestins can be greatly reduced without loss of response.

Role of lung injury in the pathogenesis of hyaline membrane disease in premature baboons

To test the hypothesis that hyaline membrane disease (HMD) has a multifactorial etiology in which barotrauma plays a major role, we compared the immediate institution of high-frequency oscillatory ventilation (HFOV; 15 Hz, n = 5) with positive-pressure ventilation with positive end-expiratory pressure (PPV; n = 7) in premature baboons (140-days gestation) with HMD. Measurements of ventilation settings and physiological parameters were obtained and arterial-to-alveolar O2 (PaO2-to-PAO2) ratio and oxygenation index [(PaO2/PAO2)-to-mean airway pressure ratio (IO2)] were calculated. At death (24 h), static pressure-volume (PV) curves were performed, and phospholipids (PL) and platelet-activating factor (PAF) were measured in lung lavage fluid. Morphological inflation patterns were analyzed using a panel of standards. By design, mean airway pressure was initially higher (19 vs. 13 cmH2O) in the HFOV animals. PaO2-to-PAO2 ratio and IO2 progressively deteriorated in the PPV animals and then stabilized at significantly lower levels than with HFOV. PV curves from HFOV animals had significant increases in lung volume at maximum distending pressure, deflation volume at 10 cmH2O, and hysteresis area compared with PPV, which showed no hysteresis. Seven of seven PPV and only one of five HFOV animals had morphological findings of HMD. PL amount and composition in both groups were consistent with immaturity, even though the quantity was significantly greater in the PPV group. PAF was present (greater than or equal to 0.10 pmol) in six of seven PPV and in the only HFOV animal with HMD. We conclude that HFOV protected PL-deficient premature baboons from changes in gas exchange, lung mechanics, and morphology typical of HMD in this model.(ABSTRACT TRUNCATED AT 250 WORDS)

Hormonal regulation of human endometrial stromal cells in culture: an in vitro model for decidualization

Stromal cells derived from proliferative or secretory human endometria, cultured in the absence of steroid hormones, grew as monolayers that showed only occasional areas of immunoreactive fibronectin and did not produce detectable levels of prolactin (PRL) or laminin. Treatment with physiological doses of estradiol and progesterone induced PRL production and stimulated cell proliferation, resulting in multilayering with an increase of the saturation density. Electron microscopy showed the development of gap junctions, whereas immunofluorescence revealed a dense pericellular matrix containing fibronectin and laminin. These findings show that human endometrial stromal cells in culture respond to physiological doses of ovarian hormones with ultrastructural, proliferative, and biochemical changes that are characteristic of decidualization in vivo. This culture system thus provides an in vitro model for human decidualization.

De Novo Lipid Synthesis Facilitates Gemcitabine Resistance through Endoplasmic Reticulum Stress in Pancreatic Cancer

Pancreatic adenocarcinoma is moderately responsive to gemcitabine-based chemotherapy, the most widely used single-agent therapy for pancreatic cancer. Although the prognosis in pancreatic cancer remains grim in part due to poor response to therapy, previous attempts at identifying and targeting the resistance mechanisms have not been very successful. By leveraging The Cancer Genome Atlas dataset, we identified lipid metabolism as the metabolic pathway that most significantly correlated with poor gemcitabine response in pancreatic cancer patients. Furthermore, we investigated the relationship between alterations in lipogenesis pathway and gemcitabine resistance by utilizing tissues from the genetically engineered mouse model and human pancreatic cancer patients. We observed a significant increase in fatty acid synthase (FASN) expression with increasing disease progression in spontaneous pancreatic cancer mouse model, and a correlation of high FASN expression with poor survival in patients and poor gemcitabine responsiveness in cell lines. We observed a synergistic effect of FASN inhibitors with gemcitabine in pancreatic cancer cells in culture and orthotopic implantation models. Combination of gemcitabine and the FASN inhibitor orlistat significantly diminished stemness, in part due to induction of endoplasmic reticulum (ER) stress that resulted in apoptosis. Moreover, direct induction of ER stress with thapsigargin caused a similar decrease in stemness and showed synergistic activity with gemcitabine. Our in vivo studies with orthotopic implantation models demonstrated a robust increase in gemcitabine responsiveness upon inhibition of fatty acid biosynthesis with orlistat. Altogether, we demonstrate that fatty acid biosynthesis pathway manipulation can help overcome the gemcitabine resistance in pancreatic cancer by regulating ER stress and stemness. Cancer Res; 77(20); 5503-17. ©2017 AACR.

Oral contraceptive use influences resting breast proliferation

The controversy that surrounds oral contraceptive use and breast cancer risk has arisen from epidemiologic studies, yet the direct effect of such use on breast tissue remains undefined. Breast epithelial proliferation was assessed by 3H-thymidine labeling of normal lobular units dissected from benign biopsies of 347 females aged 14 to 48 years. Factors shown to influence this response included cycle phase, time since menarche (breast age), and parity status. Multivariate analysis allowing for these influences was used to compare activity of natural cycles and those artificially regulated by oral contraceptives (OC). The increased activity in nulliparous OC users was highly significant (P less than .005). Comparing the effect of differences in OC type, whether combined, triphasic, progestin only, or according to estrogen or progestin content, showed a heterogeneity in response that was significant (P less than .01). Examined specifically, the formulation of OC according to progestin content did not have a significant influence, although progestin-only OC was most active, while the influence of increasing estrogen content was significant (P less than .05). However, emphasis is given to acknowledging the multiple factors and interactive processes responsible for breast epithelial stimulation when considering strategies of intervention.

A mitochondrial marker for red algal intraspecific relationships

Intraspecific studies of red algae have relied on nuclear or plastid markers rather than mitochondrial data to address questions of systematics, biogeography or population genetics. In this study, primers were developed that spanned the noncoding intergenic region between the mitochondrial cytochrome oxidase subunit 2 and cytochrome oxidase subunit 3 genes. These primers were demonstrated to be successful on a variety of red algae in different orders: Gracilariales, Bonnemaisoniales and Ceramiales (families: Delesseriaceae, Ceramiaceae and Rhodomelaceae). Amplification products were between 450 and 320 bp in length, with variation in length shown among geographically distant isolates within a species. The region was variable within a single species, as shown for Bostrychia moritziana and B. radicans, and within populations of Caloglossa leprieurii. In the latter species, four mitochondrial haplotypes were observed in isolates from a single locality in Woolooware Bay, New South Wales, Australia. Analysis of hybrids between different mitochondrial haplotypes of B. moritziana revealed that the mitochondria are maternally inherited in this species. This is the first report of a mitochondrial marker that is variable within red algal populations and may lead to a better understanding of the population ecology of these important marine organisms.

The use of protamine to study [6,7-3H] oestradiol-17-beta binding in rat uterus

1. The binding of [6,7-(3)H]oestradiol-17beta to uteri has been studied by using sucrose-gradient analysis and also the property of oestradiol receptors to form insoluble complexes with protamine. 2. Protamine precipitates the 8S and part of the 4S oestradiol-binding proteins in uterine cytoplasm from mature rats. It does not precipitate the oestradiol-17beta-binding proteins present in cytoplasm from non-target tissues or serum. No tritium-labelled material was precipitated by protamine after equilibration of [6,7-(3)H]oestradiol-17beta with either serum albumin or phosvitin. 3. Protamine precipitated a small amount of progesterone but not testosterone or cortisol that had been equilibrated with uterine cytoplasm. It did not precipitate any tritium radioactivity from muscle cytoplasm that had been equilibrated with either [1,2-(3)H]testosterone sulphate or [1,2-(3)H]dehydroepiandrosterone. 4. A simple method has been devised for measuring binding constants of tissue extracts for [6,7-(3)H]oestradiol-17beta, based on precipitation with protamine. Reasonable agreement was obtained between the values obtained by this method and those obtained by sucrose-gradient analysis. 5. This method has been used to study the effect of maturity, ovariectomy, adrenalectomy and hypophysectomy on the cytoplasmic binding of [6,7-(3)H]oestradiol-17beta. None of these procedures affected the dissociation constant K(d) or the number of binding sites/mg of cytoplasmic protein. When measured per uterus or per mg of DNA, ovariectomy and hypophysectomy decreased the number of binding sites. Adrenalectomy had no effect. 6. The properties of the 4S oestradiol-binding protein present in cytoplasm from mature uteri have been studied. It is not present in uteri from immature, ovariectomized, or hypophysectomized rats and it does not bind testosterone or cortisol. Unlabelled oestradiol-17beta, U-11,100A, N-ethylmaleimide and N-bromosuccinimide all decrease the binding of [6,7-(3)H]oestradiol-17beta to both 8S and 4S receptors. Binding to both 8S and 4S receptors decreases when oestradiol is transported to the nucleus. The 4S receptor is not the same as the 4S binding component formed by salt dissociation of the 8S receptor.

Pulmonary surfactant

Pulmonary surfactant reduces the surface tension of the alveolar air-liquid interface, thereby providing mechanical stability and preventing alveolar atelectasis. More than 50% of surfactant is dipalmitoyl phosphatidylcholine, a material that is capable of reducing the surface tension of the alveolar interface to uniquely low values. The functions of the remaining 25% unsaturated phosphatidylcholines, 5-10% phosphatidylglycerol, 5% cholesterol, and 8-10% protein are unknown. Surfactant is synthesized by alveolar epithelial type II cells and is probably secreted as a lipoprotein complex. Lamellar bodies, which distinguish type II cells, are likely to be intracellular sites of transport of processing. The catabolism of surfactant after it is secreted into the alveolar lumen is complicated and involves different turnover times for the phosphatidylcholines, phosphatidylglycerol, and the proteins. The metabolic events are under hormonal control and may involve an interplay between beta-adrenergic agonists cAMP, and prostaglandins. In disease, such as the neonatal and adult respiratory distress syndromes, derangements in the metabolic processes may produce surfactant that is abnormal with respect to its chemical and physical properties.

Pathophysiologic, morphometric, and biochemical studies of the premature baboon with bronchopulmonary dysplasia

Pathophysiologic, morphometric, and biochemical (surfactant and coagulation-fibrinolytic parameters) features were studied in premature baboons with and without bronchopulmonary dysplasia (BPD). A total of 22 baboons were delivered by hysterotomy at 75% of gestation and randomized into two groups. Group 1 (PRN) animals were ventilated with high-frequency oscillation for 48 to 72 h and then changed to positive-pressure ventilation (PPV) while maintained on clinically appropriate oxygen for the 21-day experimental period. Group 2 (BPD) animals were ventilated with PPV and 1.0 FlO2 for 7 days followed by 0.8 FlO2 for 14 days. Group 3 (control) animals were delivered and immediately killed at 140 days gestation. Group 1 animals showed no significant airway or saccular lesions, and alveolarization of the saccules was present. Group 2 animals showed metaplastic or hyperplastic epithelial lesions in airways and an alternating pattern of atelectatic but more normal appearing saccules and alveoli interposed between foci of thickened overexpanded saccular walls with no alveolarization. Differences within and between the three study groups were analyzed morphometrically. When numerical densities were examined by comparing control, PRN, BPD-atelectatic areas, and BPD-overexpanded areas. Type II cells were significantly increased in the BPD-overexpanded sites above those of control and PRN values. The interstitial cells were significantly more numerous in the BPD-atelectatic blocks compared with control and BPD-overexpanded blocks. Endothelial cell numerical densities were significantly decreased in the overexpanded sites of the BPD animals compared with the control, PRN, and BPD-atelectatic values. Volume density data showed that the interstitial compartment of the BPD group was significantly larger than those of the control and PRN groups. This was seen as significant increases in the cellular, noncellular, and connective tissue fiber components. Vascular endothelium or lumen volume densities were not different between the BPD and PRN animals, but did differ from those of the 140-day gestation controls. Comparable levels of lavage plasminogen-dependent fibrinolytic activity, were detectable at the 21-day study interval. The phospholipid composition of pulmonary surfactant, including disaturated PC and total PG, was similar between BPD and PRN groups at 21 days. The pathologic, morphometric, and biochemical patterns in this study probably represent those seen in human neonates with mild to moderate clinical BPD who survive. At this time, it is not known if the destructive endothelial lesion and the lack of alveolarization in the overexpanded and fibrotic lesions will resolve over time in long-term BPD survivors.

Tumor-intrinsic CD47 signal regulates glycolysis and promotes colorectal cancer cell growth and metastasis

Rationale: CD47 plays a vital role in the immune escape of tumor cells, but its role in regulating immune-unrelated biological processes such as proliferation and metastasis remains unclear. We seek to explore the immune-independent functions of CD47 in colorectal cancer (CRC). Methods: The expression of CD47 in CRC was determined by immunohistochemistry. The biological effect of CD47 signaling on tumor cell proliferation and metastasis was evaluated in vitro and in vivo. RNA sequencing analysis was performed to identify pivotal signaling pathways modulated by CD47. The interaction between CD47 and ENO1 was verified by co-immunoprecipitation (co-IP). The effect of CD47 on glycolytic metabolites was analyzed by seahorse XF and targeted metabolomics. Results: The expression of CD47 was upregulated and correlated to poor prognosis in CRC patients. Functional assays revealed that CD47 promoted CRC cell growth and metastasis in vitro and in vivo. Our mechanistic investigations demonstrated that CD47 interacted with ENO1 and protected it from ubiquitin-mediated degradation, subsequently promoting glycolytic activity and phosphorylation of ERK in CRC cells. Inhibition of ENO1 diminished CD47-mediated cell growth and migration. Clinically, the combined expression of CD47 and ENO1 provided reliable predictive biomarkers for the prognosis of CRC patients. Conclusions: CD47 is overexpressed in CRC, and its expression is associated with poor prognosis. Through stabilizing ENO1, CD47 enhances the aerobic glycolysis and ERK activity in CRC cells, thereby promoting the progression of CRC. Our studies reveal an unconventional role of CD47, suggesting that targeting the CD47-ENO1 axis may provide a novel therapeutic avenue for CRC.

The cholesterol pathway: impact on immunity and cancer

Cholesterol is a multifaceted metabolite that is known to modulate processes in cancer, atherosclerosis, and autoimmunity. A common denominator between these diseases appears to be the immune system, in which many cholesterol-associated metabolites impact both adaptive and innate immunity. Many cancers display altered cholesterol metabolism, and recent studies demonstrate that manipulating systemic cholesterol metabolism may be useful in improving immunotherapy responses. However, cholesterol can have both proinflammatory and anti-inflammatory roles in mammals, acting via multiple immune cell types, and depending on context. Gaining mechanistic insights into various cholesterol-related metabolites can improve our understanding of their functions and extensive effects on the immune system, and ideally will inform the design of future therapeutic strategies against cancer and/or other pathologies.

Influence of menstrual cycle, parity and oral contraceptive use on steroid hormone receptors in normal breast

Steroid receptor was assessed immunohistochemically in 158 samples of normal breast for variation through the menstrual cycle. Patterns and intensity of reaction were used in a semi-quantitative scoring system to examine the influence of cycle phase, cycle type, parity and age. The changes in oestrogen receptor for natural cycle and oral contraceptive (OC) cycles indicated down-regulation by progestins. Progesterone receptor did not vary significantly in natural cycles, but increased steadily through OC cycles. This study provides strong evidence that both oestrogen and progesterone influence breast epithelium, but dissimilarities from the endometrium are apparent. The interval since pregnancy had a significant negative effect on frequency and score of oestrogen receptor and score of progesterone receptor. Multivariate analysis established the phase of cycle and OC use as independent significant influences on oestrogen receptor. The interval since pregnancy was an independent significant factor for both oestrogen and progesterone receptor presence.

Progression to steroid insensitivity can occur irrespective of the presence of functional steroid receptors

A major problem in treatment of cancers arising in steroid-sensitive cells is their inevitable progression to a steroid-insensitive state; current therapies are based on the assumption that hormone insensitivity is associated with loss of receptor. We demonstrate for the first time that breast tumor cells can progress to steroid insensitivity in spite of functional steroid receptors. Transfection of the steroid-inducible LTR-C3 gene into unresponsive S115 mouse mammary tumor cells results in full inducibility of that gene with both androgen and glucocorticoid. Thus, although all known endogenous inducible parameters are lost, the steroid sensitivity of a transfected exogenous gene demonstrates that the machinery for steroid responsiveness is still fully functional. Furthermore, these transfected genes retain steroid sensitivity only while steroid is present; on prolonged withdrawal of steroid, they lose responsiveness, implying an epigenetic mechanism is involved.

Psychiatric disability in female carriers of the fragile X chromosome

Fragile X syndrome, an X-linked genetic condition, is an important genetic cause of mental retardation in males. In addition to mental retardation, hemizygous males with fragile X syndrome appear to have a greater likelihood of displaying behaviors classified under the diagnostic category of pervasive developmental disorder than would be expected on the basis of mental retardation alone. Although the majority of female heterozygotes with the fragile X genetic defect are of normal intelligence, our clinical work with this population and a recent case report have suggested that females with fragile X syndrome have an increased rate of schizophrenia spectrum and affective disorders. In this study, the relationship of the fragile X genetic defect to psychopathology in female heterozygotes is investigated by psychiatric evaluation of 35 obligate female carriers of the fragile X chromosome and a comparison group of 24 fragile X-negative controls. Female fragile X carriers were found to have a greater frequency of psychopathology associated with schizophrenia spectrum diagnoses, particularly schizotypal features. A weaker association between the fragile X genetic defect and chronic affective disorders was detected. The specificity of the neuropsychiatric phenotype occurring in particular genetic conditions such as the fragile X syndrome adds a potentially valuable tool to the study of psychopathology in the general population.

Physicochemical properties of dipalmitoyl phosphatidylcholine after interaction with an apolipoprotein of pulmonary surfactant

We studied the interaction between an apolipoprotein of pulmonary surfactant and the principal lipid found in this material, dipalmitoyl phosphatidylcholine. The apolipoprotein was extracted from canine surfactant and purified to greater than 90% homogeneity. The apolipoprotein was mixed for 16 h at room temperature with dipalmitoyl phosphatidylcholine dispersed in a buffer containing 0.1 M NaCl and 3mM CaCl2. Unbound lipid, unbound protein, and recombinants of lipid and protein were separated by density gradient centrifugation. 71% of the apolipoprotein was found associated with dipalmitoyl phosphatidylcholine. In comparable experiments using bovine plasma albumin about 13% of the albumin was recovered with the lipid. The physicochemical state of the lipid in the apolipoprotein-lipid complex was modified after binding of the protein. A distinct phase transition at 42 degrees C could no longer be detected, and the rate of adsorption to an air-liquid interface of the apolipoprotein-lipid complex was greater than that of the lipid alone. Surface tension vs. surface area isotherms of the dipalmitoyl phosphatidylcholine-apolipoprotein materials, however, were similar to those exhibited by pure dipalmitoyl phosphatidylcholine. The results suggest a physiological role for this apolipoprotein. It may bind to dipalmitoyl phosphatidylcholine under conditions expected in vivo, and may modify the physical properties of the aggregated dipalmitoyl phosphatidylcholine to form domains of lipid in a liquid-crystalline array. The complex dipalmitoyl phosphatidylcholine and apolipoprotein would have the physical properties necessary for its physiological function, allowing it to absorb to the alveolar interface and reduce its surface tension to less than 10 dynes/cm. Dipalmitoyl phosphatidylcholine, by itself, is in a gel-crystalline array below its phase transition temperature (42 degrees C) and would be incapable of effecting these actions.

Appearance of paoproteins of pulmonary surfactant in human amniotic fluid

We have isolated and partially characterized the protein found in surface-active material from adult human lungs, and have determined the time of appearance of this protein in amniotic fluid. Fluids were drawn at gestational ages from 12 to 44 wk, and were assayed for their concentration of apoprotein by an agglutination immunoassay. Surfactant apoprotein ((defined as that protein which is reproducibly found in purified preparations of surface active material) was usually first detected from 30 to 32 wk gestation, and its concentration increased almost fivefold to a maximum at 37 wk. The change in apoprotein concentration was approximately paralleled by the change in phospholipid concentration. At all gestational ages there was wide variability in both phospholipid and apoprotein concentrations, and the time of appearance of the apoprotein in amniotic fluid differed among fetuses. The results suggest that the presence of surfactant apoprotein in amniotic fluid is coincident with the biochemical and morphological maturation of the fetal lung, and are additional evidence that this apoprotein is cosecreted with the lipids of surface-active material.

Dose dependent effects of oral progesterone on the oestrogenised postmenopausal endometrium

Oral progesterone 100, 200, or 300 mg daily was given for the first 10 days of each calendar month to postmenopausal women also receiving conjugated oestrogens 1.25 mg daily continuously. Endometrial biopsy specimens were taken on the sixth day of the third or subsequent cycle of combined treatment for histological, ultrastructural, and biochemical evaluation. Secretory histological changes were induced within the endometrium in a dose dependent manner, as were progesterone sensitive ultrastructural features such as nucleolar channel systems, giant mitochondria, and subnuclear accumulations of glycogen. Dose response relations were also observed for suppression of DNA synthesis and nuclear oestrogen receptor, and for induction of the activities of oestradiol and isocitric dehydrogenases. Progesterone administered by mouth clearly provokes an end organ response within the endometrium. Suboptimal effects were observed with the lower doses but progesterone 300 mg daily achieved responses approaching and within the physiological range. This dose may therefore be effective as an alternative to synthetic progestogens for therapeutic purposes.