Homocysteine induces blood vessel global hypomethylation mediated by LOX-1.

Homocysteine (Hcy) is an independent risk factor of atherosclerosis through its involvement with the methionine cycle. In this study, we aimed to determine the blood vessel global methylation rate in Hcy-induced atherosclerosis in apolipoprotein-E-deficient (ApoE-/-) mice, and to explore the possible mechanism of this change in endothelial cells. ApoE-/- mice were divided into a hyperlipidemia (HLP) group, a hyperhomocysteinemia (HHcy) group, and an HHcy + folate + vitamin B12 (HHcy+FA+VB) group. Wild-type C57BL/6J mice were prepared as controls. Total Hcy, lipids, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) contents in serum were measured with an automatic biochemistry analyzer and high-performance liquid chromatography. Methylation of B1 repetitive elements in blood vessels was tested using nested methylation-specific-polymerase chain reaction (nMS-PCR). Endothelial cells (ECs) were pretreated with Hcy or by adding FA and VB. Lectin-like oxidized LDL receptor-1 (LOX-1) expressions were determined by quantitative PCR, Western blot, and nMS-PCR. The HHcy group displayed severe HLP and HHcy. SAM and SAH contents were also elevated in the HHcy group compared with other groups. Methylation of B1 repetitive elements was significantly increased in the HHcy group (0.5050 ± 0.0182) compared to the HLP (0.5158 ± 0.0163) and control (0.5589 ± 0.0236) groups. mRNA and protein expressions of LOX-1 increased (0.2877 ± 0.0341, 0.6090 ± 0.0547), whereas methylation expression decreased (0.5527 ± 0.0148) after 100 µM Hcy stimulation in ECs. In conclusion, Hcy-induced atherosclerosis was closely associated with induced hypomethylation status in the blood vessel, and this process was partially mediated by LOX-1 DNA methylation.

SOX2-associated signaling pathways regulate biological phenotypes of cancers.

SOX2 is a transcription factor involved in multiple stages of embryonic development. In related reports, SOX2 was found to be abnormally expressed in tumor tissues and correlated with clinical features such as TNM staging, tumor grade, and prognosis in patients with various cancer types. In most cancer types, SOX2 is a tumor-promoting factor that regulates tumor progression and metastasis primarily by maintaining the stemness of cancer cells. In addition, SOX2 also regulates the proliferation, apoptosis, invasion, migration, ferroptosis and drug resistance of cancer cells. However, SOX2 acts as a tumor suppressor in some cases in certain cancer types, such as gastric and lung cancer. These key regulatory functions of SOX2 involve complex regulatory networks, including protein-protein and protein-nucleic acid interactions through signaling pathways and noncoding RNA interactions, modulating SOX2 expression may be a potential therapeutic strategy for clinical cancer patients. Therefore, we sorted out the phenotypes related to SOX2 in cancer, hoping to provide a basis for further clinical translation.

Molecular cloning of HSP70 in Mycoplasma ovipneumoniae and comparison with that of other mycoplasmas.

Mycoplasma ovipneumoniae, a bacterial species that specifically affects ovine and goat, is the cause of ovine infectious pleuropneumonia. We cloned, sequenced and analyzed heat shock protein 70 (HSP70) (dnaK) gene of M. ovipneumoniae. The full length open reading frame of the M. ovipneumoniae HSP70 gene consists of 1812 nucleotides, with a G+C content of 34.16%, encoding 604 amino acids. Comparative analysis with the HSP70 sequences of 15 Mycoplasma species revealed 59 to 87% DNA sequence identity, with an amino acid sequence identity range of 58 to 94%. M. ovipneumoniae and M. hyopneumoniae shared the highest DNA and amino acid sequence identity (87 and 94%, respectively). Based on phylogenetic analysis, both the DNA and amino acid identities of M. ovipneumoniae with other mycoplasmal HSP70 were correlated with the degree of relationship between the species. The C-terminus of the HSP70 was cloned into a bacterial expression vector and expressed in Escherichia coli cells. The recombinant C-terminal portion of HSP70 protein strongly reacted with convalescent sera from M. ovipneumoniae-infected sheep, based on an immunoblotting assay. This indicates that HSP70 is immunogenic in a natural M. ovipneumoniae infection and may be a relevant antigen for vaccine development.

Prospective analysis of KRAS wild-type patients with metastatic colorectal cancer using cetuximab plus FOLFIRI or FOLFOX4 treatment regimens.

Cetuximab, a monoclonal antibody targeting epidermal growth factor receptor, has proven to be efficient in the treatment of metastatic colorectal cancer. We made a prospective study of the efficacy and toxicities of cetuximab-combination first-line (FOLFOX4) versus second/third-line (FOLFIRI) chemotherapy in 98 KRAS wild-type patients who had metastatic colorectal cancer. Wild-type KRAS had been identified by direct sequencing. Associations between clinical response/progression-free survival/overall survival/toxicities and cetuximab-combination chemotherapy timing were evaluated. The overall response rate was significantly higher for first-line treatment than for second/third-line treatment (relative risk = 1.707, 95% confidence interval = 1.121-2.598). Both progression-free survival and overall survival indicated significantly longer survival of first-line treatment than second/third-line treatment patients. This study is a validation of a molecular analysis of KRAS wild-type status for the prediction of response to cetuximab-combination chemotherapy for metastatic colorectal cancer patients; its predictive role was less prominent in the second/third-line than in the first-line treatment patients.

A dramatic shift in CO and CH4 levels at urban locations in Korea after the implementation of the Natural Gas Vehicle Supply (NGVS) program.

Concentrations of carbon monoxide (CO) and methane (CH(4)) in air were measured at both urban roadside (U-RS) and urban background (U-BG) stations in Seoul, Korea over an 11 yr period (1996-2006). The overall mean values of CO were 1.16+/-0.63 (U-RS) and 1.08+/-0.77 ppm (U-BG), while those of CH(4) were 2.24+/-0.42 (U-RS) and 2.06+/-0.31 ppm (U-BG). The diurnal patterns of CO tended to peak near rush hour, while those of CH(4) showed increases at night. An examination of the seasonal data showed that the CO values were consistently higher during winter, while CH(4) values were highly variable across seasons with relatively large spatial variations. Because of the noticeable change in air quality parameters after the year 2000, the mean data for both compounds were examined between 1996-2000 (period I) and 2001-2006 (period II). The analysis of long-term trends revealed that the concentrations of both compounds decreased very rapidly during period I, while changes were not significant during period II. The results of this comparative study confirm that both urban locations have experienced dramatic changes in the major pollutant levels, particularly in CO after the implementation of the Natural Gas Vehicle Supply (NGVS) program.

Polycyclic aromatic hydrocarbon concentration levels on the Korean peninsula between 2006 and 2008.

Concentrations of seven polycyclic aromatic hydrocarbon (PAH) compounds - benzo(a)anthracene (BaA), chrysene (CHRY), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), dibenz(a,h)anthracene (DahA), indeno(1,2,3-cd)pyrene (I123P), and benzo(a)pyrene (BaP) - in air were measured as the sum of gas and particle fractions at 32 monitoring stations dispersed across Korea during a 2-year period (February 2006 to January 2008). The data sets were collected at intervals of 1 day (24 h) per month from each monitoring station. According to our analysis, the spatial distribution of PAH is distinguished by manmade activities between different land use types. Evaluation of total PAH (T-PAH) concentration levels, which were derived by summing up all individual compounds, revealed that the T-PAH value varied on the order of commercial (4.85 + or - 4.40 ng m(-3)) rural (4.42 + or - 2.73 ng m(-3)), industrial (4.27 + or - 1.79 ng m(-3)), greenland (3.09 + or - 3.86 ng m(-3)), and background (2.60 + or - 2.54 ng m(-3)) areas. The PAH values, when compared across seasons, tend to peak consistently during the winter (or spring) due to the active consumption of fossil fuels. The overall results of this study confirm that the pollution status of PAH compounds are clearly discernible not only between areas with different levels of anthropogenic activities, but also between periods with changes in environmental conditions.

Carcinoembryonic antigen in monitoring of response to cetuximab plus FOLFIRI or FOLFOX-4 in patients with metastatic colorectal cancer.

First-line treatment of metastatic colorectal cancer with combinations of cetuximab and irinotecan-based or oxaliplatin-based chemotherapy has shown promising efficacy. The clinical response to such treatment is generally assessed by tumor measurement through imaging. This study was performed to evaluate the correlation between serial changes in imaging results and carcinoembryonic antigen (CEA) levels. In 64 patients with metastatic colorectal cancer receiving cetuximab plus FOLFIRI or FOLFOX-4 chemotherapy we retrospectively analyzed the relationship between changes in serum CEA and changes in imaging results throughout the treatment course. Response in terms of serum CEA change was defined as a >/=50% drop in CEA level for more than 4 weeks. The sensitivity and specificity of serum CEA changes after targeted chemotherapy in relation to imaging results were 80.5% (33/41) and 73.9% (17/23), respectively, with a diagnostic accuracy of 78.1% (50/64). The progression-free survival time of responders assessed by serum CEA change was significantly longer than that of nonresponders (p=0.0091). Our results highlight the importance of serum CEA monitoring in assessing the response to targeted chemotherapy and in predicting the prognosis of patients with metastatic colorectal cancer.

Malignant mixed müllerian tumor of primary mesenteric origin associated with a synchronous ovarian cancer: case report and literature review.

Malignant mixed müllerian tumor (MMMT) is a rare tumor in females and extragenital MMMT is even more so. We report a patient with MMMT primarily in the mesentery with synchronous ovarian cancer. In the English literature, 42 cases of extragenital MMMT have been reported other than the presented case, and this is only the second MMMT arising from the mesentery. Furthermore, among the cases reviewed, MMMTs tend to be associated with synchronous or metachronous colonic cancer or gynecologic tumors originating from the müllerian duct, including ovarian tumors, fallopian tube cancer, endometrial cancer, cervical cancer, and serous carcinoma of the peritoneum (14 out of 43 patients; 32.6%). The risk factors for MMMT include obesity, nulliparity, exogenous estrogen, and long-term tamoxifen use. The prognosis of MMMT is catastrophic and the treatment is based on the experience of those of uterine sarcomas, which is composed of operation, radiotherapy and chemotherapy.

Prognostic significance of pre- and postoperative serum carcinoembryonic antigen levels in patients with colorectal cancer.

BACKGROUND: To evaluate the prognostic significance of pre- and postoperative serum carcinoembryonic antigen(CEA) levels in colorectal cancer (CRC) patients. METHODS: 425 CRC patients underwent curative resection at our institution. Their pre- and postoperative serum CEA level was classified into two groups according to concentration: normal CEA (<5.0 ng/ml) and abnormal CEA (> or =5.0 ng/ml). RESULTS: Of all patients, abnormal pre- and postoperative serum CEA levels were observed in 181 (42.6%) and 48 (11.3%) patients, respectively. Abnormal preoperative serum CEA level was significantly correlated with the tumor located in the colon, the depth of tumor invasion, the status of lymph node metastasis, UICC stage, and the presence of postoperative relapse (p < 0.05). Concurrently, an abnormal postoperative serum CEA level was also prominently related to the above corresponding parameters (p < 0.05), except for the tumor location. Patients with a failed conversion of abnormal preoperative value to normal postoperative concentration were found to have the worst overall survival rate. Abnormal pre- and postoperative serum CEA levels were single independent predictors for survival and postoperative relapse, respectively. CONCLUSIONS: The identification of abnormal pre- and postoperative serum CEA levels may be useful in the auxiliary cancer prognosis or postoperative surveillance of CRC patients.

Single-Stranded DNA Curtains for Studying Homologous Recombination.

Homologous recombination is an important pathway involved in the repair of double-stranded DNA breaks. Genetic studies form the foundation of our knowledge on homologous recombination. Significant progress has also been made toward understanding the biochemical and biophysical properties of the proteins, complexes, and reaction intermediates involved in this essential DNA repair pathway. However, heterogeneous or transient recombination intermediates remain extremely difficult to assess through traditional ensemble methods, leaving an incomplete mechanistic picture of many steps that take place during homologous recombination. To help overcome some of these limitations, we have established DNA curtain methodologies as an experimental platform for studying homologous DNA recombination in real-time at the single-molecule level. Here, we present a detailed overview describing the preparation and use of single-stranded DNA curtains in applications related to the study of homologous DNA recombination with emphasis on recent work related to the study of the eukaryotic recombinase Rad51.