[A Method for Isolating Tumor Cells from Large Volume of Malignant Pleural 
Effusion and Its Efficacy Evaluation].

BACKGROUND: Malignant plural effusion (MPE) is one of the most common specimen for liquid biopsy gene detection. This study aims to explore a method for isolating tumor cells from large volume of MPE and evaluate its efficacy and application prospect in gene detection. METHODS: Pleural effusions (>500 mL) from 20 advanced lung cancer patients were obtained by effusion drainage and used to isolate tumor cells with cell separation media Percoll and Ficoll. Cell number and purity were calculated. DNA was extracted from the supernatant (etDNA), total cells and isolated tumor cells of pleural effusion (ETC-DNA) to detect the mutation of tumor-related genes by next-generation sequencing. RESULTS: The median number of cells isolated from malignant pleural effusion was 8.50×104 (interquel range: 9.25×10³-3.75×105), 85.50%±5.80% of the cells were identified as tumor cells. The detection rates of epidermal growth factor receptor (EGFR) gene mutation of etDNA, total cell DNA and ETC-DNA were 70.00%, 50.00% and 70.00%, reseparately, while the median EGFR mutation abundance in 3 components was 16.05% (4.78%-43.06%), 1.09% (0.00%-2.39%), and 33.02% (18.50%-76.70%), respectively. ETC-DNA had good consistency with tissue DNA (P>0.999, kappa=1.000) and etDNA (P>0.999, kappa=1.000). ETC-DNA inclined to have higher EGFR mutation than etDNA, but the result was not statistically significant. CONCLUSIONS: Our method can isolate large amount of tumor cells from a large volume of malignant pleural effusion with high purity. Using ETC-DNA as specimen improves the efficacy of gene detection, thus is worth further study.

Lung Cancer Combination Treatment: Evaluation of the Synergistic Effect of Cisplatin Prodrug, Vinorelbine and Retinoic Acid When Co-Encapsulated in a Multi-Layered Nano-Platform.

PURPOSE: Lung cancer remains the leading cancer-associated deaths worldwide. Cisplatin (CIS) was often used in combination with other drugs for the treatment of non-small cell lung cancer (NSCLC). Prodrug is an effective strategy to improve the efficiency of drugs and reduce the toxicity. The aim of this study was to prepare and characterize CIS prodrug, vinorelbine (VNR), and all-trans retinoic acid (ATRA) co-delivered multi-layered nano-platform, evaluating their antitumor activity in vitro and in vivo. METHODS: Cisplatin prodrug (CISP) was synthesized. A multi-layered nano-platform contained CISP, VNR and ATRA were prepared and named CISP/VNR/ATRA MLNP. The physicochemical properties of CISP/VNR/ATRA MLNP were investigated. In vitro cytotoxicity against CIS-resistant NSCLC cells (A549/CIS cells) and Human normal lung epithelial cells (BEAS-2B cells) was investigated, and in vivo anti-tumor efficiency was evaluated on mice bearing A549/CIS cells xenografts. RESULTS: CISP/VNR/ATRA MLNP were spherical particles with particle size and zeta potential of 158 nm and 12.3 mV. CISP/VNR/ATRA MLNP (81.36%) was uptake by cancer cells in vitro. CISP/VNR/ATRA MLNP could significantly inhibit the in vivo antitumor growth and suspended the tumor volume from 1440 mm3 to 220 mm3. CONCLUSION: It could be concluded that the CISP/VNR/ATRA MLNP may be used as a promising system for lung cancer combination treatment.

Critical evaluation of Cbx7 downregulation in primary colon carcinomas and its clinical significance in Chinese patients.

BACKGROUND: CBX7 is a Polycomb group protein that shows variable expression changes in various cancers that are often contradictive. A mouse knockout experiment has validated the tumor suppressor role in carcinogenesis. The purpose of this study is to verify the tumor suppressor role of Cbx7 in human colon carcinomas (CC). METHODS: Frozen CC and the surgical margin (SM) tissue samples from patients (n = 97) were obtained from the Peking University Cancer Hospital. All patients had follow-up data for at least three years. The level of Cbx7 mRNA and protein was determined by quantitative RT-PCR, immunohistochemistry and Western blot, respectively. The association between Cbx7 mRNA level and clinicopathological characteristics of CC patients was then statistically analyzed. RESULTS: CBX7 expression changes detected through immunohistochemistry and Western blot in 10 pairs of representative CC samples significantly correlated with their corresponding mRNA levels when Alu, but not GAPDH, was used as the endogenous reference control in quantitative RT-PCR. The Alu-normalized Cbx7 mRNA levels were significantly increased in SM tissues when compared with CC tissues or colon biopsies taken from non-cancer patients (Student's t-test, P < 0.036 or 0.007). Furthermore, decreased levels of Cbx7 mRNA positively correlated with lymph metastasis (P = 0.029). Overall survival (OS) of CC patients classified as Cbx7 expression-low was considerably shorter than those classified as Cbx7 expression-high (Hazard ratio = 2.97, 95% CI [1.68 ~ 5.25]; P <0.001). Multiple variant analyses showed that the Cbx7 expression-low was an independent predictor of short OS (Hazard ratio = 3.16, 95% CI [1.58-6.30]; P < 0.001). CONCLUSION: Cbx7 is downregulated in CCs, and Cbx7 expression-low tumors correlated with lymph metastasis and poor overall survival of CC patients.

Large-scale characterization of DNA methylation changes in human gastric carcinomas with and without metastasis.

PURPOSE: Metastasis is the leading cause of death for gastric carcinoma. An epigenetic biomarker panel for predicting gastric carcinoma metastasis could have significant clinical impact on the care of patients with gastric carcinoma. The main purpose of this study is to characterize the methylation differences between gastric carcinomas with and without metastasis. EXPERIMENTAL DESIGN: Genome-wide DNA methylation profiles between 4 metastatic and 4 nonmetastatic gastric carcinomas and their surgical margins (SM) were analyzed using methylated-CpG island amplification with microarray. The methylation states of 73 candidate genes were further analyzed in patients with gastric carcinoma in a discovery cohort (n=108) using denatured high performance liquid chromatography, bisulfite-sequencing, and MethyLight. The predictive values of potential metastasis-methylation biomarkers were validated in cohorts of patients with gastric carcinoma in China (n=330), Japan (n=129), and Korea (n=153). RESULTS: The gastric carcinoma genome showed significantly higher proportions of hypomethylation in the promoter and exon-1 regions, as well as increased hypermethylation of intragenic fragments when compared with SMs. Significant differential methylation was validated in the CpG islands of 15 genes (P<0.05) and confirmed using bisulfite sequencing. These genes included BMP3, BNIP3, CDKN2A, ECEL1, ELK1, GFRA1, HOXD10, KCNH1, PSMD10, PTPRT, SIGIRR, SRF, TBX5, TFPI2, and ZNF382. Methylation changes of GFRA1, SRF, and ZNF382 resulted in up- or downregulation of their transcription. Most importantly, the prevalence of GFRA1, SRF, and ZNF382 methylation alterations was consistently and coordinately associated with gastric carcinoma metastasis and the patients' overall survival throughout discovery and validation cohorts in China, Japan, and Korea. CONCLUSION: Methylation changes of GFRA1, SRF, and ZNF382 may be a potential biomarker set for prediction of gastric carcinoma metastasis.

Characterization of human gastric carcinoma-related methylation of 9 miR CpG islands and repression of their expressions in vitro and in vivo.

BACKGROUND: Many miR genes are located within or around CpG islands. It is unclear whether methylation of these CpG islands represses miR transcription regularly. The aims of this study are to characterize gastric carcinoma (GC)-related methylation of miR CpG islands and its relationship with miRNA expression. METHODS: Methylation status of 9 representative miR CpG islands in a panel of cell lines and human gastric samples (including 13 normal biopsies, 38 gastritis biopsies, 112 pairs of GCs and their surgical margin samples) was analyzed by bisulfite-DHPLC and sequencing. Mature miRNA levels were determined with quantitative RT-PCR. Relationships between miR methylation, transcription, GC development, and clinicopathological characteristics were statistically analyzed. RESULTS: Methylation frequency of 5 miR CpG islands (miR-9-1, miR-9-3, miR-137, miR-34b, and miR-210) gradually increased while the proportion of methylated miR-200b gradually decreased during gastric carcinogenesis (Ps < 0.01). More miR-9-1 methylation was detected in 62%-64% of the GC samples and 4% of the normal or gastritis samples (18/28 versus 2/48; Odds ratio, 41.4; P < 0.01). miR-210 methylation showed high correlation with H. pylori infection. miR-375, miR-203, and miR-193b methylation might be host adaptation to the development of GCs. Methylation of these miR CpG islands was consistently shown to significantly decrease the corresponding miRNA levels presented in human cell lines. The inverse relationship was also observed for miR-9-1, miR-9-3, miR-137, and miR-200b in gastric samples. Among 112 GC patients, miR-9-1 methylation was an independent favourable predictor of overall survival of GC patients in both univariate and multivariate analysis (P < 0.02). CONCLUSIONS: In conclusion, alteration of methylation status of 6 of 9 tested miR CpG islands was characterized in gastric carcinogenesis. miR-210 methylation correlated with H. pylori infection. miR-9-1 methylation may be a GC-specific event. Methylation of miR CpG islands may significantly down-regulate their transcription regularly.

Pharmacogenetic assessment of clinical outcome in patients with metastatic breast cancer treated with docetaxel plus capecitabine.

PURPOSE: Docetaxel plus capecitabine, a commonly used chemotherapeutic regimen for metastatic breast cancer (MBC), is highly variable in its effectiveness. We aimed to investigate whether allelic variants of cytochrome P450 (CYP450) affected objective response, progression-free survival (PFS), and overall survival (OS) in MBC. PATIENTS AND METHODS: 79 SNPs in CYP450, whose minor allele frequency were ≥ 10%, were genotyped in 69 MBC patients who were treated with docetaxel plus capecitabine. Pearson's χ(2) test or Fisher's exact test was used to investigate the influence of SNPs on objective response as appropriate. Log-rank test was used to assess the association between SNPs and survival outcomes. RESULTS: There is no significant association between polymorphisms and both objective response and OS. Only one SNP, CYP1A1 rs1048943 A>G (Ile462Val), was significantly associated with PFS (P = 0.0003). Multivariate analysis confirmed its prognostic significance for PFS (P = 0.004). CONCLUSION: CYP1A1 rs1048943 A>G (Ile462Val) polymorphism is a potential prognostic marker for survival outcome after docetaxel plus capecitabine chemotherapy in MBC patients. However, confirmatory study is needed to validate this finding.

Polycomb CBX7 directly controls trimethylation of histone H3 at lysine 9 at the p16 locus.

BACKGROUND: H3K9 trimethylation (H3K9me3) and binding of PcG repressor complex-1 (PRC1) may play crucial roles in the epigenetic silencing of the p16 gene. However, the mechanism of the initiation of this trimethylation is unknown. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we found that upregulating the expression of PRC1 component Cbx7 in gastric cancer cell lines MGC803 and BGC823 led to significantly suppress the expression of genes within the p16-Arf-p15 locus. H3K9me3 formation was observed at the p16 promoter and Regulatory Domain (RD). CBX7 and SUV39H2 binding to these regions were also detectable in the CBX7-stably upregulated cells. CBX7-SUV39H2 complexes were observed within nucleus in bimolecular fluorescence complementation assay (BiFC). Mutations of the chromodomain or deletion of Pc-box abolished the CBX7-binding and H3K9me3 formation, and thus partially repressed the function of CBX7. SiRNA-knockdown of Suv39h2 blocked the repressive effect of CBX7 on p16 transcription. Moreover, we found that expression of CBX7 in gastric carcinoma tissues with p16 methylation was significantly lower than that in their corresponding normal tissues, which showed a negative correlation with transcription of p16 in gastric mucosa. CONCLUSION/SIGNIFICANCE: These results demonstrated for the first time, to our knowledge, that CBX7 could initiate H3K9me3 formation at the p16 promoter.

Involvement of hepatopoietin Cn in the development of human hepatocellular carcinoma.

Hepatopoietin Cn (HPPCn) is a novel nuclear protein with the ability to promote liver regeneration. In the present study, we investigated the expression profile of HPPCn and its functional activity in human hepatocellular carcinoma (HCC) cell line and tissue samples. HPPCn expression was detected in HCC cell lines and 54 paired HCC carcinomas by immunochemical staining and Western blotting. The functional activity of HPPCn in cell lines was evaluated by MTT and colony formation assays and with nude mouse model. The correlation of HPPCn expression with clinicopathological characteristics of 54 HCC patients was also analyzed. Our results showed that HPPCn protein was prominently located within the nuclei of hepatocytes and the expression level was evidently increased in HepG2 and Bel7402 cell lines compared with L02 normal hepatocytes. HPPCn silencing by small interfering RNA greatly suppressed HepG2 cell proliferation and colony formation capacity and the inhibitory effect was also observed in a Balb/c-null mouse model. The silencing HPPCn expression effectively enhanced the apoptosis of HepG2 cells. In addition, HPPCn expression was detected in 48 of 54 (89%) human HCC tissues in sharp contrast with the corresponding non-tumor liver tissues. HPPCn protein was mainly accumulated in the tumor nucleus. The elevated expression of HPPCn protein in tumors was significantly associated with poor tumor cellular differentiation and present of vascular invasion. Patients with higher HPPCn expression in tumors had significantly shorter overall survival (OS) of both all of patients and the patients at the early stage. On multivariate Cox analysis, elevated expression of HPPCn in tumors was found to be an independent prognostic factor for OS. Therefore, these data suggest that HPPCn expression might be involved in the development of HCC and could be served as a promising biomarker.

Methylation of GATA-4 and GATA-5 and development of sporadic gastric carcinomas.

AIM: To understand the implication of GATA-4 and GATA-5 methylation in gastric carcinogenesis. METHODS: Methylation status of GATA-4 and GATA-5 CpG islands in human gastric mucosa samples, including normal gastric biopsies from 45 outpatients, gastric dysplasia [low-grade gastric intraepithelial neoplasia (GIN), n = 30; indefinite, n = 77], and 80 paired sporadic gastric carcinomas (SGC) as well as the adjacent non-neoplastic gastric tissues was analyzed by methylation specific polymerase chain reaction (MSP) and confirmed by denatured high performance liquid chromatography (DHPLC). Immunohistochemical staining was used to detect protein expression. The correlation between GATA-4 and GATA-5 methylation and clinicopathological characteristics of patients including Helicobacter pylori (H. pylori) infection was analyzed. RESULTS: GATA-4 and GATA-5 methylation was frequently observed in SGCs (53.8% and 61.3%, respectively) and their corresponding normal tissues (41.3% and 46.3%) by MSP. The result of MSP was consistent with that of DHPLC. Loss of both GATA-4 and GATA-5 proteins was associated with their methylation in SGCs (P = 0.01). Moreover, a high frequency of GATA-4 and GATA-5 methylation was found in both gastric low-grade GIN (57.1% and 69.0%) and indefinite for dysplasia (42.9% and 46.7%), respectively. However, GATA-4 and GATA-5 methylation was detected only in 4/32 (12.5%) and 3/39 (7.7%) of normal gastric biopsies. GATA-4 methylation in both normal gastric mucosa and low-grade GIN was also significantly associated with H. pylori infection (P = 0.023 and 0.027, two-sides). CONCLUSION: Epigenetic inactivation of GATA-4 (and GATA-5) by methylation of CpG islands is an early frequent event during gastric carcinogenesis and is significantly correlated with H. pylori infection.

Methylation status of individual CpG sites within Alu elements in the human genome and Alu hypomethylation in gastric carcinomas.

BACKGROUND: Alu methylation is correlated with the overall level of DNA methylation and recombination activity of the genome. However, the maintenance and methylation status of each CpG site within Alu elements (Alu) and its methylation status have not well characterized. This information is useful for understanding natural status of Alu in the genome and helpful for developing an optimal assay to quantify Alu hypomethylation. METHODS: Bisulfite clone sequencing was carried out in 14 human gastric samples initially. A Cac8I COBRA-DHPLC assay was developed to detect methylated-Alu proportion in cell lines and 48 paired gastric carcinomas and 55 gastritis samples. DHPLC data were statistically interpreted using SPSS version 16.0. RESULTS: From the results of 427 Alu bisulfite clone sequences, we found that only 27.2% of CpG sites within Alu elements were preserved (4.6 of 17 analyzed CpGs, A approximately Q) and that 86.6% of remaining-CpGs were methylated. Deamination was the main reason for low preservation of methylation targets. A high correlation coefficient of methylation was observed between Alu clones and CpG site J (0.963), A (0.950), H (0.946), D (0.945). Comethylation of the sites H and J were used as an indicator of the proportion of methylated-Alu in a Cac8I COBRA-DHPLC assay. Validation studies showed that hypermethylation or hypomethylation of Alu elements in human cell lines could be detected sensitively by the assay after treatment with 5-aza-dC and M.SssI, respectively. The proportion of methylated-Alu copies in gastric carcinomas (3.01%) was significantly lower than that in the corresponding normal samples (3.19%) and gastritis biopsies (3.23%). CONCLUSIONS: Most Alu CpG sites are deaminated in the genome. 27% of Alu CpG sites represented in our amplification products. 87% of the remaining CpG sites are methylated. Alu hypomethylation in primary gastric carcinomas could be detected with the Cac8I COBRA-DHPLC assay quantitatively.

[Biological properties of mesenchymal stem cells derived from bone marrow of patients with multiple myeloma].

The study was purposed to explore the role of mesenchymal stem cells (MSCs) in the pathogenesis of bone disease particularly observed in multiple myeloma (MM), the biological features of marrow derived MSCs from patients with MM have been investigated. Marrow aspirates were harvested from 11 newly diagnosed patients with MM and 5 normal adults and MSCs were isolated and culture-expanded by the cell properties of adherence to plastic flasks, The phenotype was analyzed by flow cytometric technique. The proliferation of MSCs was observed by MTT assay and their differentiation capacities into osteoblasts and adipoblasts were assessed with lineage-specific histochemical staining. The concentrations of IL-6 and SCF in the culture supernatant were detected by enzyme-linked immunosorbent assay (ELISA). MSC culture supernatants were collected and MTT assay was performed to evaluate their support on the proliferation of an MM cell line SKO007 cells. The results showed that bone marrow-derived MSCs from MM patients were homogeneously positive for CD29, CD73, CD166 and HLA-ABC and negative for hematopoietic cell marker CD45 and endothelial cell marker CD31, the phenotype of which was similar to that of marrow counterparts from normal adults. MTT assay indicated that MSCs from MM patients or normal adults proliferated at similar rates. MSCs from MM patients occupied in vitro osteogenic and adipogenic capacity as those from normal adults. The levels of IL-6 and SCF in culture supernatant were greatly up-regulated in MM patients by ELISA assay. Furthermore, MSC culture supernatants from MM bone marrow displayed enhanced activity to promote the proliferation of SKO007 cells. It is concluded that marrow-derived MSCs from bone marrow of MM patients are normal in their proliferation and differentiation capacities, and myeloma bone disease may not be ascribed to the differentiation of MSCs while the elevated secretion of IL-6 and SCF may provide necessary cues for the survival of malignant myeloma cells.

[Prognostic value of thymidylate synthase, topoisomerase-1 and Ki-67 in advanced colorectal cancer patients on irinotecan and fluorouracil treatment].

OBJECTIVE: To investigate the prognostic value of thymidylate synthase (TS), topoisomerase-1 (Topo-1), and proliferating index Ki-67 in advanced colorectal cancer patients on irinotecan (CPT-11) in combination with fluorouracil treatment (5-Fu). METHODS: The biomarker expression of TS, Topo-1 and Ki-67 in 78 patients detected immunohistochemically were correlated with the clinical outcome. RESULTS: The expressions of those biomarkers were not correlated with clinical therapeutic response, but with time to progression (TTP) and/or overall survival (OS). Patients with low expression of TS had significantly longer TTP (P < 0.05) and in OS (P < 0.05). The low expression of Ki-67 was also significantly predictive of longer survival (P < 0.05). As compared with any biomarker, the combination of any two biomarkers still possessed no predictive value to therapeutic response, but an enhanced predictive value to prognosis. The median time to progression in patients with low expression of TS, or Ki-67, or both were 9, 8 and 17 months, respectively; in patients with low expression of TS, or Topo-1, or both were 9, 9 and 13 months; in patients with low expression of Topo-1, or Ki-67, or both were 8, 9 and 11 months. TTP was significantly longer in patients with low expression of two biomarkers as compared with those with high expression (P = 0.031). CONCLUSION: TS, Topo-1, and Ki-67 are not predictive for chemotherapy response to CPT-11 combined with 5-Fu, but valuable in predicting prognosis. The combination of any two biomarkers can provide more powerful prognostic information for advanced colorectal cancer patients.

Antitumor effect of Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, combined with cytotoxic agent on murine hepatocellular carcinoma.

AIM: To investigate the inhibitory effect of gefitinib combined with cytotoxic agent cisplatin (CDDP) on hepatocellular carcinoma (HCC). METHODS: Female Kunming mice and H22 hepatocarcinoma cells were used. Gefitinib at daily dose of 100 mg/kg body weight (BW) or lecithin liquid was given by gastrogavage once a day for 5 or 10 successive days. CDDP or normal saline (NS) was administered intraperitoneally (i.p.) once a day for 5 successive days. Mice were randomly divided into control group (lecithin, or NS, i.p.), CDDP group (daily dose, 1.2 mg/kg BW; d1-5, or d6-10), Gefitinib (d1-5, or d6-10, or d1-10), and Gefitinib combined with CDDP groups. The inhibitory rate (IR) of tumor, net BW, spleen index (SI), thymus index (TI) and the amount of peripheral blood cells of mice were detected on the 12th experiment day. RESULTS: The growth of HCC in mice was inhibited by Gefitinib alone (IR: 41% in d1-10 group and 30% in d1-5 group, respectively) or CDDP alone (IR: 32-54% in d1-5 group or d6-10 group). The highest inhibitory effect (IR: 56%) on HCC growth was observed in Gefitinib (d1-10) combined with CDDP (d1-5) group. Higher inhibition was also observed in CDDP (d1-5) followed by Gefitinib (d6-10) group than that in Gefitinib (d1-5) followed by CDDP (d6-10) group (IR: 61% vs 36%, P < 0.01) in the independent study. Net BW, SI, TI and the amount of blood cells of mice in Gefitinib alone group were not significantly different from those in control groups. CONCLUSION: Gefitinib can significantly inhibit the growth of murine H22 hepatocellular carcinoma. If Gefitinib is used after CDDP treatment in animal experiments, the inhibitory effect could be enhanced.

[The effect of IRESSA on H22 mouse hepatocellular carcinoma].

OBJECTIVE: To investigate the effect of IRESSA (gefitinib, ZD1839) on H22 murine hepatocellular carcinoma. METHODS: Mice bearing H22 hepatocellular carcinoma were randomly divided into oral control group, Normal saline (NS) control group, cisplatin (CDDP) d1-5 group, CDDP d6-10 group, IRESSA group, IRESSA combined with CDDP early (IRESSA + CDDP d1-5) group, and IRESSA combined with CDDP lately (IRESSA + CDDP d6-10) group. IRESSA was given by daily gastrogavage for 10 days (day 1-day 10) at 100 mg/kg in body weight (BW). CDDP was given by daily intraperitoneal injection for 5 days (day 1-day 5, or day 6-day 10) at 1.2 mg/kg in BW. The growth inhibiting rate (IR) of tumor, change of BW, spleen index (SI), and amounts of blood leucocyte or hemoglobin were detected. RESULTS: IR of tumor in IRESSA group was not significantly difference with that in CDDP d1-5 group, CDDP d6-10 group, IRESSA + CDDP d1-5 group (P > 0.05). IR of tumor in IRESSA group, CDDP d1-5 group, CDDP d6-10 group, IRESSA and IRESSA + CDDP d1-5 group were 41%, 54%, 46%, and 56%, respectively. IR of tumor in IRESSA + CDDP d6-10 group (26%) was significantly lower than that in CDDP d6-10 group (P < 0.05) or in IRESSA + CDDP d1-5 group (P < 0.01). Compared with oral or NS control groups, SI and net BW in IRESSA group was not significantly difference (P > 0.05). SI and net BW in both IRESSA + CDDP d1-5 group and IRESSA + CDDP d6-10 group were lower markedly than those in IRESSA group (P < 0.01). CONCLUSION: Tumor growth of H22 bearing mice was markedly inhibited by IRESSA.

[Enhancement of antioxidant capability of cancer patients during chemotherapy by reduced glutathione].

BACKGROUND & OBJECTIVE: It is unknown how administration of reduced glutathione (GSH) affects chemotherapy of cancer patients. This study was designed to investigate the effect of GSH on lipid peroxidation, and activities of antioxidant enzyme among cancer patients with chemotherapy. METHODS: Sixty-two cancer patients with chemotherapy were enrolled randomly into AB or BA group in cross-over pattern. In AB group, combination of chemotherapy and GSH was administrated first, then following chemotherapy alone was given 21 or 28 days later. In group BA, chemotherapy alone was administrated first, then the combination therapy was given. Duration of chemotherapy was 2-5 days, 21-28 days for a cycle, depended on chemotherapy strategies. GSH was given as a 15 minute intravenous infusion at the dose of 1 500 mgx(m(2)xd)(-1) for 7 days from day 1. Serum samples were collected from the patients on the day just before the chemotherapy, the 7(th) day, and the 21(st) (if 21 days per cycle of the chemotherapy) or 28(th) day of treatment. Concentration of malondialdehyde (MDA), activity of glutathione peroxidase (GSH-Px), and total superoxide dismutase (T-SOD) of serum samples were analyzed biochemically. RESULTS: (1)Administration of chemotherapy significantly increased serum MDA level on the 7(th) day compared with that before chemotherapy (mean+/-SD,6.12+/-1.94 micromol/L versus 4.63+/-1.87 micromol/L,P< 0.01). The increased serum MDA level was restored partially (5.05+/-2.07)micromol/L on the 21(th) or 28(th) day, but still higher than that before chemotherapy (P< 0.05). (2)Serum activity of T-SOD and GSH-Px decreased on the 7(th) day (P< 0.01) and restored partially on the 21(th) or 28th day, but still lower than that before chemotherapy (T-SOD, P< 0.05;GSH-Px,P< 0.01).(3)Co-treatment of GSH prevents lipid peroxidation and depletion of antioxidant enzymes by chemotherapy partially but significantly (P< 0.01). (4)Similar results were obtained in both AB group and BA group. CONCLUSION: Chemotherapy depletes antioxidant capability of cancer patients and co- treatment of GSH might prevent such depletion.

Hypermethylation of metallothionein-3 CpG island in gastric carcinoma.

The expression of metallothionein (MT)-3 is often markedly reduced in gastric carcinoma (GC). The molecular mechanism of this MT-3 downregulation is unknown. Transcriptional silencing of MT-3 by methylation of CpG island was investigated by nucleotide sequencing and denaturing high performance liquid chromatography (DHPLC) analyses. We found that normal brain tissue and a xenografted GC that expressed MT-3 mRNA had unmethylated regions of the CpG island in intron1 of this gene. On the other hand, gastric cancer cell lines AGS and MKN445, a xenografted GC, and a representative primary gastric cancer that had no expression of MT-3 mRNA demonstrated hypermethylation of the MT-3 intron1 CpG island. Treatment of the gastric cancer cell lines with 5-azacytidine resulted in new expression of MT-3 mRNA in these cells. A quantifying DHPLC assay was developed to determine the methylation status of this specific region of the MT-3 gene. Fifty-eight primary GC and their corresponding normal gastric epithelial tissues, and 34 normal gastric mucosa were analyzed for MT-3 methylation by DHPLC in the region of methylation abnormalities initially identified. Our DHPLC analyses of the methylated MT-3 product demonstrated that the primary gastric cancers have an average methylation percentage of 6.3% per tumor compared with 2.4% in normal gastric tissues (P < 0.05). The MT-3 was not methylated in all of eight P53-positive GCs and hypermethylated in eight of 13 P53-negative cases by immunohistochemistry staining (P = 0.007). In conclusion, the CpG island in the MT-3 intron1 are abnormally hypermethylated in many gastric carcinomas and may account for the downregulation of MT-3 in gastric carcinogenesis.

Silencing-specific methylation and single nucleotide polymorphism of hMLH1 promoter in gastric carcinomas.

AIM: To investigate CpG methylation and single nucleotide polymorphism (SNP) of a specific promoter region of hMLH1 in primary gastric carcinoma. METHODS: Primary gastric carcinomas (n=80), their corresponding normal mucosal samples, and gastric mucosal biopsies from normal/gastritis control patients (n=54) were used. Hypermethylation at -253 nt and -251 nt in relation with the translational start site and SNP of a silencing specific region (-339 nt-46 nt) in the hMLH1 promoter were analyzed by Bst UI-combined bisulfite assay (COBRA), denaturing high performance liquid chromatogram (DHPLC), and sequencing. RESULTS: (A) The specific methylation at -253 nt and -251 nt was observed in 2 of 60 primary gastric carcinomas, but neither in all of the corresponding mucosa nor in normal/gastritis samples, by Bst UI-COBRA and DHPLC. (B) The hMLH1 promoter was methylated homogeneously in the xenograft of the primary gastric carcinoma with the methylated and unmethylated hMLH1. (C) The pattern of SNP at -93 nt of the hMLH1 promoter in 54 Chinese patients with gastric carcinoma was the same as that in the control patients: 51 % was A/G heteroalleles, 34 % and 15 % were A/A and G/G homoalleles, respectively. CONCLUSION: Biallelic inactivation of hMLH1 by epigenetic silencing existed in human primary gastric carcinoma homogeneously. Hypermethylation of hMLH1 may play a role in the early stage of development of a few gastric carcinomas. The SNP at -93 nt is not related to the susceptibility of gastric carcinomas.

[Effect of serum leptin on nutritional status of patients with cancer].

In order to investigate the effect of serum leptin and its potential as a parameter for the accessment of nutritional status of patients with cancer, serum leptin concentration, body mass index (BMI), blood erythrocyte, hemoglobin, serum albumin, lipid and lipoprotein concentration of 325 cancer patients and 66 healthy controls are meatured. The incidence of patients with BMI < 18.5, hypoalbumia, anemia, hypercholesterolemia, and hypertriglyceridemia is 23%, 14%, 42%, 17.2%, and 21.4% respectively. The incidence of patients with BMI < 18.5 in pulmonary carcinoma is obviously lower than that of those with gastric carcinoma (P = 0.022). The incidence of patients with hyperglycosemia and hypertriglyceridemia in pulmonary carcinoma is obviously higher than that of those with gastric carcinoma (P = 0.003 and P = 0.029 respectively). Serum leptin concentration in the patients with malnutrition is significantly lower than that of those with no malnutrition and that of those obese patients (P = 0.000). There is no significant difference in serum leptin concentration between patients with cancer and healthy control persons with same gender and with BMI value ranged from 18.5 to 25. It is shown that the BMI, gender and serum albumin concentration are all influencing factors to the serum leptin concentration and the serum leptin concentration is significantly correlated with BMI, gender and serum albumin concentrations (r = 0.599-0.698, P = 0.000). The above mentioned results from this study indicate that there is a high anemia incidence of patients with cancer. Serum leptin concentration can reflect the changes in BMI and nutritional status of the patients with cancer. The serum leptin concentration has the potential of being a parameter for assessing nutritional status of the patients with cancer.