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The dietary intake of methyl donors is favorably associated with many diseases, but the findings regarding primary liver cancer (PLC) risk are limited. This study investigated the association between the intake of choline, betaine and methionine and PLC risk in adults. This 1:1 matched case-control study enrolled 644 hospital-based PLC patients and 644 community-based controls who were matched by sex and age, in Guangzhou, China. An interviewer-administered questionnaire and a food-frequency questionnaire were used to collect general information and dietary intake information. Conditional logistic regression showed a significantly inverse association between total choline and betaine intakes and PLC risk. The multivariable-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for PLC for the top (vs. bottom) tertile were 0.34 (0.24–0.49; P -trend P -trend = 0.011) for betaine. No significant association was observed between the intake of methionine and PLC risk (P > 0.05). For individual choline compounds, higher consumptions of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin were associated with a lower PLC risk (all P-trend P-interactions: 0.488–0.890). Our findings suggest that higher choline and betaine intakes may be associated with a lower risk of PLC.

Osteosarcoma is a type of malignant bone tumor with high metastasis and poor prognosis. Previous studies have demonstrated the involvement of LIM kinase 1 (LIMK1) in the proliferation of osteosarcoma cells. LIMK1 is overexpressed in human osteosarcoma tissues and cell lines. To further study LIMK1-associated mechanisms, we used shRNA targeted to the LIMK1 gene to block its expression in the osteosarcoma cell lines MG63 and U2OS. Insulin promoted the proliferation of MG63 cells in a time- and dose-dependent manner, however, this insulin induced proliferation was significantly inhibited by transfection of shRNA targeted to the LIMK1 gene, as well as by the PI3K inhibitor LY294002, but not by the mitogen‑activated protein kinase (MAPK) inhibitor PD98059. The level of cofilin phosphorylation was increased significantly following stimulation of insulin for 24 h, indicating the activation of LIMK1. MG63 cell proliferation was also significantly inhibited by 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in a time-dependent manner. Furthermore, 1,25(OH)2D3 negated the inhibitory effect of LIMK1 shRNA, indicating that LIMK1 is important in the inhibitory pathway of 1,25(OH)2D3. The present study confirms that LIMK1 is important in regulating osteosarcoma cell proliferation via the insulin/PI3K/LIMK1 signaling pathway, thus the development of gene therapy for osteosarcoma targeting LIMK1 is warranted.

Multidrug resistance (MDR) is a challenge for the treatment of cancer and the underlying molecular mechanisms remain elusive. The current study exposed MG63 osteosarcoma cells to increasing concentrations of vincristine (VCR) to establish four VCR‑resistant MG63/VCR cell sublines (MG63/VCR1, 2, 3 and 4). The drug resistance indices (RI) of these sublines was detected with the CCK‑8 assay and determined to be163, 476, 1,247, and 2,707‑fold higher than that of parental cells, respectively. These sublines also exhibited cross‑resistance to doxorubicin, paclitaxel and pirarubicin. With increased RI, the proliferative capacity of these sublines was gradually reduced and cell morphology was also altered, characterized by increased formation of pseudopodia and long cytoplasmic processes at opposite poles. However, the migration capacity and expression of certain drug resistance‑associated genes were not in accordance with the increased RI; multidrug resistance protein 1 (MDR1) expression was significantly increased in these sublines compared with parental cells. However, in the highly resistant MG63/VCR3 and MG63/VCR4 cells, MDR‑associated protein 1, topoisomerase II and LIM domain kinase 1 levels were significantly reduced compared with the moderately resistant MG63/VCR2 cells. Expression of glutathione S‑transferase‑π mRNA was determined using reverse transcription‑quantitative polymerase chain reaction and determined that it was not changed between MG63 and MG63/VCR cells. The data of the present study demonstrated that the molecular alterations of drug resistance may change with the degree of drug resistance. Taking cell morphology into consideration, the intratumor clonal and phenotypic heterogeneity may be responsible for drug resistance. These MG63/VCR sublines may be a valuable tool to assess drug resistance and the underlying mechanisms, and to identify novel drug resistance‑associated genes or strategies to overcome MDR in human osteosarcoma.

Since the 1990s, a number of terminal alkynyl residue-containing cyclic/acyclic peptides have been identified from marine organisms, especially cyanobacteria and marine mollusks. This review has presented 66 peptides, which covers over 90% marine peptides with terminal alkynyl fatty acyl units. In fact, more than 90% of these peptides described in the literature are of cyanobacterial origin. Interestingly, all the linear peptides featured with terminal alkyne were solely discovered from marine cyanobacteria. The objective of this article is to provide an overview on the types, structural characterization of these unusual terminal alkynyl fatty acyl units, as well as the sources and biological functions of their composed peptides. Many of these peptides have a variety of biological activities, including antitumor, antibacterial, antimalarial, etc. Further, we have also discussed the evident biosynthetic origin responsible for formation of terminal alkynes of natural PKS (polyketide synthase)/NRPS (nonribosome peptide synthetase) hybrids.

SUMMARY Cytoglobin (Cygb) is a novel tissue hemoprotein relatively similar to myoglobin (Mb). Because Cygb shares several structural features with Mb, we hypothesized that Cygb functions in the modulation of oxygen and nitric oxide metabolism or in scavenging free radicals within a cell. In the present study we examined the spatial and temporal expression pattern of Cygb during murine embryogenesis. Using in situ hybridization, RT-PCR, and Northern blot analyses, limited Cygb expression was observed during embryogenesis compared with Mb expression. Cygb expression was primarily restricted to the central nervous system and neural crest derivatives during the latter stages of development. In the adult mouse, Cygb is expressed in distinct regions of the brain as compared with neuroglobin (Ngb), another globin protein, and these regions are responsive to oxidative stress (i.e., hippocampus, thalamus, and hypothalamus). In contrast to Ngb, Cygb expression in the brain is induced in response to chronic hypoxia (10% oxygen). These results support the hypothesis that Cygb is an oxygen-responsive tissue hemoglobin expressed in distinct regions of the normoxic and hypoxic brain and may play a key role in the response of the brain to a hypoxic insult. (J Histochem Cytochem 54:1349–1361, 2006)