Comparative lipidomics of 5-Fluorouracil-sensitive and -resistant colorectal cancer cells reveals altered sphingomyelin and ceramide controlled by acid sphingomyelinase (SMPD1).

5-Fluorouracil (5-FU) is a chemotherapeutic drug widely used to treat colorectal cancer. 5-FU is known to gradually lose its efficacy in treating colorectal cancer following the acquisition of resistance. We investigated the mechanism of 5-FU resistance using comprehensive lipidomic approaches. We performed lipidomic analysis on 5-FU-resistant (DLD-1/5-FU) and -sensitive (DLD-1) colorectal cancer cells using MALDI-MS and LC-MRM-MS. In particular, sphingomyelin (SM) species were significantly up-regulated in 5-FU-resistant cells in MALDI-TOF analysis. Further, we quantified sphingolipids including SM and Ceramide (Cer) using Multiple Reaction Monitoring (MRM), as they play a vital role in drug resistance. We found that 5-FU resistance in DLD-1/5-FU colorectal cancer cells was mainly associated with SM increase and Cer decrease, which are controlled by acid sphingomyelinase (SMPD1). In addition, reduction of SMPD1 expression was confirmed by LC-MRM-MS analysis and the effect of SMPD1 in drug resistance was assessed by treating DLD-1 cells with siRNA-SMPD1. Furthermore, clinical colorectal cancer data set analysis showed that down-regulation of SMPD1 was associated with resistance to chemotherapy regimens that include 5-FU. Thus, from our study, we propose that SM/Cer and SMPD1 are new potential target molecules for therapeutic strategies to overcome 5-FU resistance

Activation of spleen tyrosine kinase is required for TNF-α-induced endothelin-1 upregulation in human aortic endothelial cells

AbstractEndothelin-1 (ET-1) promotes atherosclerosis. We tested whether spleen tyrosine kinase (Syk) mediates tumor necrosis factor-α (TNF-α)-induced ET-1 upregulation in human aortic endothelial cells (HAECs) and sought to identify the signal pathways involved. TNF-α-induced reactive oxygen species (ROS) activated Syk and phosphatidylinositol 3-kinase (PI3K), which was required for the activation of AP-1 and subsequent ET-1 gene transcription. ROS mediated c-Jun NH2-terminal kinase (JNK) is also required for AP-1 activation, but Syk and PI3K regulated AP-1 activation independently of JNK. Through regulation of ET-1 production, Syk could be implicated in atherosclerosis

Impact of hypothyroidism on the development of non-alcoholic fatty liver disease: A 4-year retrospective cohort study

Background/AimsHypothyroidism is reported to contribute to the development of nonalcoholic fatty liver disease (NAFLD). We compared the risk of the development of NAFLD among three groups with different thyroid hormonal statuses (control, subclinical hypothyroidism, and overt hypothyroidism) in a 4-year retrospective cohort of Korean subjects.MethodsApparently healthy Korean subjects without NAFLD and aged 20-65 years were recruited (n=18,544) at health checkups performed in 2008. Annual health checkups were applied to the cohort for 4 consecutive years until December 2012. Based on their initial serum-free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels, they were classified into control, subclinical hypothyroidism (TSH >4.2 mIU/L, normal fT4), and overt hypothyroidism (TSH >4.2 mIU/L, fT4 <0.97 ng/dL) groups. NAFLD was diagnosed on the basis of ultrasonography findings.ResultsNAFLD developed in 2,348 of the 18,544 subjects, representing an overall incidence of 12.7%: 12.8%, 11.0%, 12.7% in the control, subclinical hypothyroidism, and overt hypothyroidism groups, respectively. The incidence of NAFLD did not differ significantly with the baseline thyroid hormonal status, even after multivariate adjustment (subclinical hypothyroidism group: hazard ratio [HR]=0.965, 95% confidence interval [CI]=0.814-1.143, P=0.67; overt hypothyroidism group: HR=1.255, 95% CI=0.830-1.899, P=0.28).ConclusionsOur results suggest that the subclinical and overt types of hypothyroidism are not related to an increased incidence of NAFLD

Trans-1,3-diphenyl-2,3-epoxypropan-1-one, a chalcone derivative, induces apoptosis via ROS-mediated down-regulation of Bcl-xL in human leukemia HL-60 cells

The anticancer effects of trans-1,3-diphenyl-2,3-epoxypropan-1-one (DPEP), a chalcone derivative, were investigated in human leukemia HL-60 cells. Treatment of HL-60 cells with various concentration of DPEP resulted in a sequence of events characteristic of apoptosis, including loss of cell viability, morphological changes, and increased sub-G1 DNA content. We demonstrated that DPEP elevates reactive oxygen species (ROS) levels in HL-60 cells, and that the ROS scavenger N-acetylcysteine (NAC) could block DPEP-induced ROS generation and apoptosis. Western blot analysis revealed that DPEP inhibits Bcl-xL expression, leading to caspase-3 activation and poly-ADP-ribose polymerase (PARP) cleavage, thereby inducing apoptosis. However, NAC pretreatment significantly inhibited the activation of caspase-3 and PARP cleavage and reduced Bcl-xL levels. These findings provide the first evidence that DPEP may inhibit the growth of HL-60 cells and induce apoptosis through a ROS-mediated Bcl-xL pathway

A study on the measurement of the nucleated red blood cell (nRBC) count based on birth weight and its correlation with perinatal prognosis in infants with very low birth weights

PurposeThe aim of this study was conducted to investigate the mean nRBC count in very low births weight infants (VLBWIs) and to determine the usefulness of the nRBC as an independent prognostic factors of perinatal complications in VLBWIs.MethodsThis study was conducted on 112 VLBWIs who were hospitalized in the neonatal intensive care unit (NICU) of the author's hospital within the period from March 2003 to and May 2008. Based on the infants' nucleated red blood cells (nRBC) counts at birth, on the third day after birth, on the seventh day after birth, in the second week after birth, and in the fourth week after birth in the medical records, the correlation between nRBC or absolute nRBC counts with birth weight, gestational age, and other perinatal outcomes were retrospectively investigated.ResultsIn VLBWIs, their mean nRBC and absolute nRBC counts were showing a gradual decrease after birth, and they were consisteantly kept at low values since one week after and inversely proportional to the birth weights. The mean nRBC counts based on the stage after birth showed a significant correlation with perinatal death, necrotizing enterocolitis, and severe intraventricular hemorrhage.ConclusionThe increase in the nRBC count showed a significant correlation with having a severe intraventricular hemorrhage, necrotizing enterocolitis, and perinatal death in VLBWIs. If an increase or no decrease in the nRBC count after birth is observed, newborn-infant care precautions should be required