Dialysate Lavage: An Alternative Solution for Reducing the Peritoneal Implantation of Poorly Differentiated Gastric Cancer Cells.

BACKGROUND: Peritoneal lavage after cancer surgery is performed to reduce microscopic residual tumors in the peritoneum. This study evaluated the effects and mechanism of dialysate lavage in reducing the peritoneal implantation of gastric cancer cells. METHODS: Gastric cancer cells (MKN45 or AGS) were cultured with 1.5% peritoneal dialysate (PD) or normal saline (NS) for 30 min. The in vitro cell susceptibility to dialysate, including cell proliferation, cell death, cleaved PARP expression, and mitochondrial membrane potential, was evaluated. A murine model for gastric cancer cell peritoneal seeding was established to test the effects of PD and NS lavage on animal survival and tumor growth. RESULTS: A significant decrease in cell proliferation in PD and NS (75.2 ± 0.1 vs. 12.4 ± 0.2% in MKN45, p = 0.009; 58.2 ± 0.01 vs. 28.0 ± 0.01% in AGS, p = 0.008), an increase in mitochondrial permeability transition (93.0 ± 2.6 vs. 18.0 ± 2.9% in MKN45, p = 0.021; 86.8 ± 4.6 vs. 47.7 ± 10.2% in AGS, p < 0.001), and an increase in the expression of cleaved PARP and increased death (25.6 ± 9.4 vs. 16.9 ± 5.3% in MKN45, p = 0.031; 39.5 ± 5.1 vs. 20.9 ± 3.9% in AGS, p = 0.008) were recorded for gastric cancer cells separately exposed to PD and NS. Twenty-four days after inoculating MKN45 cells (5 × 10(6)/0.1 ml) in the peritoneal cavity, the average number of seeded tumors was 67.3 ± 10.8, 92.3 ± 6.0, and 29.2 ± 16.7 (p = 0.032), and the total weight of tumors was 0.98 ± 0.21, 0.58 ± 0.12, and 0.31 ± 0.17 g (p = 0.008), respectively, for mice receiving sham operation, NS lavage, and PD lavage. The 45-day survival rate for the PD lavage group was 22% compared to 0% for the sham injection and NS lavage groups (p = 0.034). CONCLUSION: PD induced significant cytotoxicity in gastric cancer cells that was related to mitochondrial perturbation. The use of PD lavage was effective in reducing the peritoneal implantation of gastric cancers in a murine model.

Prediction consistency and clinical presentations of breast cancer molecular subtypes for Han Chinese population.

BACKGROUND: Breast cancer is a heterogeneous disease in terms of transcriptional aberrations; moreover, microarray gene expression profiles had defined 5 molecular subtypes based on certain intrinsic genes. This study aimed to evaluate the prediction consistency of breast cancer molecular subtypes from 3 distinct intrinsic gene sets (Sørlie 500, Hu 306 and PAM50) as well as clinical presentations of each molecualr subtype in Han Chinese population. METHODS: In all, 169 breast cancer samples (44 from Taiwan and 125 from China) of Han Chinese population were gathered, and the gene expression features corresponding to 3 distinct intrinsic gene sets (Sørlie 500, Hu 306 and PAM50) were retrieved for molecular subtype prediction. RESULTS: For Sørlie 500 and Hu 306 intrinsic gene set, mean-centring of genes and distance-weighted discrimination (DWD) remarkably reduced the number of unclassified cases. Regarding pairwise agreement, the highest predictive consistency was found between Hu 306 and PAM50. In all, 150 and 126 samples were assigned into identical subtypes by both Hu 306 and PAM50 genes, under mean-centring and DWD. Luminal B tended to show a higher nuclear grade and have more HER2 over-expression status than luminal A did. No basal-like breast tumours were ER positive, and most HER2-enriched breast tumours showed HER2 over-expression, whereas, only two-thirds of ER negativity/HER2 over-expression tumros were predicted as HER2-enriched molecular subtype. For 44 Taiwanese breast cancers with survival data, a better prognosis of luminal A than luminal B subtype in ER-postive breast cancers and a better prognosis of basal-like than HER2-enriched subtype in ER-negative breast cancers was observed. CONCLUSIONS: We suggest that the intrinsic signature Hu 306 or PAM50 be used for breast cancers in the Han Chinese population during molecular subtyping. For the prognostic value and decision making based on intrinsic subtypes, further prospective study with longer survival data is needed.

Quality of life in Taiwanese breast cancer survivors with breast-conserving therapy.

BACKGROUND/PURPOSE: Breast cancer is the most common female malignancy in Taiwan; however, quality of life (QOL) following breast cancer therapy remains rarely studied. The aim of the present study was to evaluate QOL among Taiwanese breast cancer patients with and without breast-conserving therapy. METHODS: A total of 130 women with breast cancer (37 with breast-conserving therapy and 93 with modified radical mastectomy) were enrolled between August, 2004 and December, 2007 in a single center. Patients who underwent breast-conserving therapy were younger, less likely to be married, had a higher educational level, and were at an earlier clinical stage than those who underwent modified radical mastectomy. The traditional Chinese version of the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 questionnaires were used as measuring instruments. Structural equation modeling with mean structural analysis, which evaluates configuration invariance and compares groups for latent functional/symptomatic factors, was constructed using a multi-indicators approach. RESULTS: Patients with breast-conserving therapy reported worse global QOL status and role function scores and higher symptomatic scores for fatigue, pain, dyspnea, insomnia, appetite loss, breast and arm problem subscales than those without conserving therapy. In addition, age, marital status, hormone manipulation and postoperative adjuvant therapy were significant confounders for QOL. Measurement invariance was ascertained and the same QOL construct could be applied to Taiwanese subjects with and without breast-conserving therapy. CONCLUSION: Our study suggests that breast-conserving therapy might be associated with worse perceived QOL for Taiwanese breast cancer survivors.

Linoleic acid promotes mitochondrial biogenesis and maintains mitochondrial structure for prevention of streptozotocin damage in RIN-m5F cells.

Linoleic acid (LA) improves insulin resistance and prevents diabetes. To investigate whether linoleic acid could protect against streptozotocin (STZ)-induced cell death, rat RIN-m5F cells were exposed to STZ. SL and SO groups consisted of cells treated with STZ and then LA or oleic acid (OA) respectively. STZ treatment decreased the mitochondrial membrane potential in the STZ, SO, and SL groups. Cells of the SL group had more intact mitochondria. Increased mRNA expression of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA), as well as of the mitochondrial biogenesis regulators peroxisome proliferator activated receptor gamma coactivator-1alpha (PGC-1alpha), and mitochondrial transcription factor A (Tfam), were found in the LA group. The insulin content was significantly decreased in all three groups. These results suggest that the effects of LA on cell viability after STZ damage occur through maintenance of mitochondrial structure and increased mitochondrial biogenesis.

Maintenance of mitochondrial DNA copy number and expression are essential for preservation of mitochondrial function and cell growth.

To examine whether a reduction in the mtDNA level will compromise mitochondrial biogenesis and mitochondrial function, we created a cell model with depleted mtDNA. Stable transfection of small interfering (si)RNA of mitochondrial transcription factor A (Tfam) was used to interfere with Tfam gene expression. Selected stable clones showed 60-95% reduction in Tfam gene expression and 50-90% reduction in cytochrome b (Cyt b) gene expression. Tfam gene knockdown clones also showed decreased mtDNA-encoded cytochrome c oxidase subunit I (COX I) protein expression. However, no significant differences in protein expression were observed in nuclear DNA (nDNA)-encoded mitochondrial respiratory enzyme subunits. The cell morphology changed from a rhombus-like to a spindle-like form as determined in clones with decreased expressions of Tfam, mtRNA, and mitochondrial proteins. The mitochondrial respiratory enzyme activities and ATP production in such clones were significantly lower. The proportions of mtDNA mutations including 8-hydroxy-2'-deoxyguanosine (8-OHdG), a 4,977-bp deletion, and a 3,243-point mutation were also examined in these clones. No obvious increase in mtDNA mutations was observed in mitochondrial dysfunctional cell clones. The mitochondrial respiratory activity and ATP production ability recovered in cells with increased mtDNA levels after removal of the specific siRNA treatment. These experimental results provide direct evidence to substantiate that downregulation of mtDNA copy number and expression may compromise mitochondrial function and subsequent cell growth and morphology.

Quality of life of inguinal hernia patients in Taiwan: The application of the hernia-specific quality of life assessment instrument.

BACKGROUND: With the development of prosthetic mesh and tension free techniques, the recurrence rate following inguinal hernia repair has been reduced, and hernia outcomes research should focus on post-operative quality of life and potential complications. STUDY DESIGN: A novel hernia quality of life assessment instrument, HERQL, was developed. The HERQL questionnaire comprises a 4-item summative pain score measuring pain and discomfort resulting from various strenuous activities. Symptomatic and functional domains, as well as post-operative satisfaction are evaluated as well. RESULTS: A total of 386 HERQL surveys were completed by 183 patients with inguinal hernias. Internal consistency reliability of the summative pain score was satisfactory, with a Cronbach's alpha of 0.85. Criterion validity was examined by concomitant assessment of the pain/discomfort and health impact subscales of the EQ-5D questionnaire, with substantial to moderate correlations. Pre-operative patients reported more severe hernia protrusion, more pain during mild to heavy exercise, and worse activity restriction and health impairment than the follow-up patients, indicating clinical validity. The conceptual structure of the HERQL demostrated the causal relationship between the formative symptomatic subscales and the reflective functional status indicators. Repeated measurement of the summative pain scores revealed an estimated time effect of -1.63, which was the rate of change in the summative pain score across the pre-operative, immediately post-operative, and follow-up 3-month periods suggesting the clinical responsiveness of the HERQL. CONCLUSIONS: This study will facilitate inguinal hernia outcomes research and enhance the quality of care for this common disease by providing a validated HERQL instrument with enhanced sensitivity.

Estrogen receptor status prediction by gene component regression: a comparative study.

The aim of the study is to evaluate gene component analysis for microarray studies. Three dimensional reduction strategies, Principle Component Regression (PCR), Partial Least Square (PLS) and Reduced Rank Regression (RRR) were applied to publicly available breast cancer microarray dataset and the derived gene components were used for tumor classification by Logistic Regression (LR) and Linear Discriminative Analysis (LDA). The impact of gene selection/filtration was evaluated as well. We demonstrated that gene component classifiers could reduce the high-dimensionality of gene expression data and the collinearity problem inherited in most modern microarray experiments. In our study gene component analysis could discriminate Estrogen Receptor (ER) positive breast cancers from negative cancers and the proposed classifiers were successfully reproduced and projected into independent microarray dataset with high predictive accuracy.

Concurrent gene signatures for han chinese breast cancers.

The interplay between copy number variation (CNV) and differential gene expression may be able to shed light on molecular process underlying breast cancer and lead to the discovery of cancer-related genes. In the current study, genes concurrently identified in array comparative genomic hybridization (CGH) and gene expression microarrays were used to derive gene signatures for Han Chinese breast cancers. We performed 23 array CGHs and 81 gene expression microarrays in breast cancer samples from Taiwanese women. Genes with coherent patterns of both CNV and differential gene expression were identified from the 21 samples assayed using both platforms. We used these genes to derive signatures associated with clinical ER and HER2 status and disease-free survival. DISTRIBUTIONS OF SIGNATURE GENES WERE STRONGLY ASSOCIATED WITH CHROMOSOMAL LOCATION: chromosome 16 for ER and 17 for HER2. A breast cancer risk predictive model was built based on the first supervised principal component from 16 genes (RCAN3, MCOLN2, DENND2D, RWDD3, ZMYM6, CAPZA1, GPR18, WARS2, TRIM45, SCRN1, CSNK1E, HBXIP, CSDE1, MRPL20, IKZF1, and COL20A1), and distinct survival patterns were observed between the high- and low-risk groups from the combined dataset of 408 microarrays. The risk score was significantly higher in breast cancer patients with recurrence, metastasis, or mortality than in relapse-free individuals (0.241 versus 0, P<0.001). The concurrent gene risk predictive model remained discriminative across distinct clinical ER and HER2 statuses in subgroup analysis. Prognostic comparisons with published gene expression signatures showed a better discerning ability of concurrent genes, many of which were rarely identifiable if expression data were pre-selected by phenotype correlations or variability of individual genes. We conclude that parallel analysis of CGH and microarray data, in conjunction with known gene expression patterns, can be used to identify biomarkers with prognostic values in breast cancer.

Functional modulation of mitochondria by eicosapentaenoic acid provides protection against ceramide toxicity to C6 glioma cells.

Mitochondrial dysfunction and associated apoptosis have been reported in the pathogenesis of neuron degeneration. The effects of eicosapentaenoic acid (EPA) and arachidonic acid (AA) on the mitochondrial membrane potential, mitochondrial biogenesis, and mitochondrial function of rat C6 glioma cells were determined in this study. Increased cytochrome c release and activated caspase-3 expression were determined in cells treated with >20 microM C(2) ceramide. There were significant repressive effects on ceramide-induced cell death with 25-100 microM EPA and 25 microM AA pretreatment. However, significantly increased membrane potentials were detected in cells pretreated with 25 and 50 microM EPA compared to ceramide-treated cells, but not in AA pretreatment groups. In cells pretreated with EPA, ATP production loss was prevented from ceramide-induced mitochondrial dysfunction. In mitochondrial biogenesis related assay, both EPA and AA enhanced peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1alpha) and mitochondrial transcription factor A (Tfam) transcriptional activities. However, elevated PGC-1alpha transcriptional activities in groups pretreated with 25, 50, and 100 microM EPA and only in the 100 microM AA group were analyzed. The Tfam transcriptional activities were enhanced in groups pretreated with 25 and 50 microM EPA and AA. Increased NADH dehydrogenase subunit 6 (ND6) mRNA expression was determined in cells pretreated with 25 and 50 microM EPA and 25 microM AA. Elevated protein levels of Tfam, flavoprotein, and cytochrome oxidase subunit III (COX III) were determined in cells pretreated with 25 and 50 microM EPA. The EPA-provided a more protective effect than AA against ceramide-induced cell death, which might mainly be due to maintaining the membrane potential and sustaining the mitochondrial ATP production function. EPA has more potential to elevate mitochondrial biogenesis through enhanced PGC-1alpha, and Tfam transcriptional activities may provide partial protection against ceramide cytotoxicity.