RP11-81H3.2 Acts as an Oncogene via microRNA-490-3p Inhibition and Consequential Tankyrase 2 Up-Regulation in Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a serious threat to human lives and is usually diagnosed at the late stages. Recently, there has been a rapid advancement in the treatment options for HCC, but novel therapeutic targets are still needed, especially for precision medicine. AIMS: We aimed to investigate the involvement of non-coding RNA RP11-81H3.2 in HCC. METHODS: The expression of RP11-81H3.2 was examined in the blood samples of HCC patients, and in the human HCC cell lines, including HepG2, Smmc-7721, and Huh7. Cell proliferation was determined using the CCK-8 and EdU assay, and cell invasion and migration were determined using the transwell/wound healing assay. The effects of RP11-81H3.2 knockdown on in vivo tumor growth were evaluated utilizing the nude mice HepG2 tumor xenograft model. RESULTS: Here, we have identified a long non-coding RNA, RP11-81H3.2, which is enriched in HCC and can promote its proliferation, migration, and invasion both in vitro and in vivo. In addition, our results showed that RP11-81H3.2 binds to and regulate miR-490-3p expression in the HCC cells. Moreover, we found that RP11-81H3.2 regulates the expression of TNKS2 via miR-490-3p. Further, we found that RP11-81H3.2 and miR-490-3p form a regulatory loop; the release of RP11-81H3.2 leads to the suppression of miR-490-3p expression, thus, further enhancing the expression of RP11-81H3.2. CONCLUSIONS: Our data have provided a novel target for the diagnosis and treatment of HCC, and sheds light on the lncRNA-miRNA regulatory nexus that can control the HCC related pathogenesis.

Upregulated long-non-coding RNA DLEU2 exon 9 expression was an independent indicator of unfavorable overall survival in patients with esophageal adenocarcinoma.

In this study, we aimed to explore the expression profiles of some known functional lncRNAs in esophageal adenocarcinoma (EAD) and to screening the potential prognostic makers, using data from The Cancer Genome Atlas (TCGA)-esophageal carcinoma (ESCA). Results showed that DLEU2 is a high potential OS related marker among 73 functional lncRNAs. DLEU2 and its intronic miR-15a and miR-16-1 expression were significantly upregulated in EAD compared with adjacent normal tissues. However, miR-15a and miR-16-1 expression were only weakly correlated with DLEU2 expression. Univariate and multivariate analysis confirmed that DLEU2 expression, but not miR-15a or miR-16-1 expression is an independent prognostic marker in terms of OS (HR:1.688, 95%CI: 1.085-2.627, p = 0.020) in EAD patients. The exon 9 of DLEU2 is very strongly co-expressed with DLEU2 (Pearson's r = 0.96) and showed better predictive value than total DLEU2 expression in predicting the OS of EAD patients. Multivariate analysis confirmed its independent prognostic value (HR:1.970, 95%CI: 1.266-3.067, p = 0.003), after adjustment of histologic grade, pathological stages and the presence of residual tumor. By checking the methylation status of DLEU2 gene, we excluded the possibility of the influence of two CpG sites near the DLEU2 exon 9 locus on its expression. In addition, although copy number alterations (CNAs) were observed DLEU2 gene, heterozygous loss (-1), low-level copy gain (+1) and high-level amplification (+2) had no significant association with DLEU2 transcription. Based on these findings, we infer that DLEU2 exon 9 expression might serve as a valuable biomarker of unfavorable OS in EAD patients.

Downregulation of microRNA-4295 enhances cisplatin-induced gastric cancer cell apoptosis through the EGFR/PI3K/Akt signaling pathway by targeting LRIG1.

Gastric cancer (GC) is one of the leading causes of cancer-associated mortality worldwide. The aim of the present study was to investigate the mechanism of microRNA-4295 (miR-4295), which regulates cisplatin (DDP)-induced apoptosis in GC cells through the leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1)-mediated epidermal growth factor receptor (EGFR)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Two cell lines were selected, one with the highest expression of miR-4295 and one with the lowest expression of LRIG1, for the experiments. The half maximal inhibitory concentration of DDP in the human GC MKN-28 and MKN-45 cell lines was calculated, and mitochondrial membrane potentials of the GC cells were detected by tetramethylrhodamine, ethyl ester, perchlorate staining. The proliferation and apoptosis of GC cells with or without DDP treatment were assessed by MTT assay and plate colony formation, as well as flow cytometry and TUNEL staining. Western blot analysis and reverse transcription-quantitative polymerase chain reaction were employed to determine the expression of EGFR/PI3K/Akt signaling pathway-related genes and apoptosis-related genes. LRIG1 was identified as a target gene of miR-4295. The expression of miR-4295 was upregulated, and the expression of LRIG1 was downregulated in GC cells. Furthermore, DDP enhanced the decrease in miR-4295 expression and the increase in LRIG1 expression in GC cells. miR-4295 promoted the proliferation and inhibited the DDP-induced apoptosis of GC cells without DDP treatment. In addition, miR-4295 increased the expression levels of EGFR, PI3K, Akt, p-PI3K and p-Akt, suggesting that miR-4295 promotes the activation of the EGFR/PI3K/Akt signaling pathway by targeting LRIG1. miR-4295 targeted and negatively regulated LRIG1 expression to activate the EGFR/PI3K/Akt signaling pathway, thereby promoting the proliferation of the GC cells and inhibiting the apoptosis of the GC cells induced by DDP. Therefore, miR-4295 may be a novel therapeutic target in patients with GC.

Clinicopathological and Prognostic Significance of Expression of B-Cell-Specific Moloney Murine Leukemia Virus Insertion Site 1 (BMI-1) Gene and Protein in Gastrointestinal Stromal Tumors.

BACKGROUND Gastrointestinal stromal tumor (GIST) is an uncommon visceral sarcoma that arises predominantly in the gastrointestinal tract. Since GISTs are encountered infrequently and inflexible to traditional therapy, the aim of the present study was to explore the correlation of B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI-1) mRNA and BMI-1 protein levels with the clinicopathological characteristics and prognosis significance of GISTs. MATERIAL AND METHODS GIST tissues and normal tissues were collected from 156 patients who had undergone surgical treatment. RT-qPCR and immunohistochemistry were used to measure the BMI-1 mRNA and protein levels in GIST tissues and normal tissues. Univariate survival analysis was used for determination of the factors that affect prognosis of GIST patients. Cox proportional hazards model was plotted to determine the independent risk factors for prognosis of GIST patients. RESULTS The BMI-1 mRNA and protein levels in GIST tissues were higher than those in normal tissues. BMI-1 mRNA and positive protein levels were correlated with the National Institutes of Health (NIH) risk grade, tumor diameter and infiltration, and metastasis. There was a short survival period for the patients with a positive protein level and a high mRNA level of BMI-1. The site of primary tumor, tumor diameter, NIH risk grade, infiltration, and metastasis, as well as BMI-1 mRNA and protein levels were independent risk factors for prognosis of GIST patients. CONCLUSIONS Taken together, these findings suggest there might be a relationship between BMI-1 mRNA and protein levels, and clinicopathological characteristics, including NIH risk grade, tumor size as well as infiltration and metastasis, of GIST patients. In addition, BMI-1 mRNA and protein levels were identified as independent risk factors for prognosis of GIST patients.

Overexpression of Contactin 1 promotes growth, migration and invasion in Hs578T breast cancer cells.

BACKGROUND: Contactin1 (CNTN1) has been shown to play an important role in the invasion and metastasis of several tumors; however, the role of CNTN1 in breast cancer has not been fully studied. The purpose of this study is to investigate the role of CNTN1 in regulating tumor growth, migration and invasion in breast cancer. RESULTS: To investigate its function, CNTN1 was expressed in Hs578T cells. CNTN1 expression was confirmed by western blot, immunohistochemistry and real-time RT-PCR. The effect of CNTN1 overexpression on proliferation, migration and invasion of Hs578T breast cancer cells was assessed in vitro and in vivo. Our results showed that CNTN1 overexpression promoted Hs578T cell proliferation, cell cycle progression, colony formation, invasion and migration. Notably, overexpression of CNTN1 in Hs578T cells enhanced the growth of mouse xenograft tumors. CONCLUSIONS: CNTN1 promotes growth, metastasis and invasion of Hs578T breast cancer cell line. Thus, therapies targeting CNTN1 may prove efficacious for breast cancer. However, further investigation is required to understand the mechanism by which CNTN1 influences proliferation, metastasis and invasion in breast cancer.

Clinicopathology and Survival in Patients with Gastroesophageal Reflux After Radical Surgery of Proximal Gastric Cancer.

BACKGROUND: Gastroesophageal reflux (GR) after radical resection of proximal gastric cancer (PGC) may influence survival; however, few studies have investigated survival in PGC patients who develop GR following radical resection. This study aimed to correlate the occurrence of GR after proximal gastrectomy (PG) and total gastrectomy (TG) with clinicopathological factors and long-term survival. METHODS: The PGC patient cohort was retrospectively grouped as follows: postoperative patients with and without GR (NGR). Clinicopathological characteristics and survival data were compared between the two groups. RESULTS: A total of 88 patients who underwent PG (53%) experienced postoperative GR; however, only 30 patients who underwent TG (14%) experienced GR (P = 0.000). The incidence of GR was significantly associated with surgical procedure (P < 0.01), tumor size (P < 0.01), infiltration depth (P < 0.01), lymph node metastasis (P = 0.018), postoperative distant metastasis (P < 0.01) and recurrence (P = 0.001). The 5-year overall survival of the GR group was significantly worse than that of the NGR group (39.3 vs. 46.5%, respectively; P = 0.046). The PG and TG groups had significantly different 5-year overall survival (45.2 vs. 50.9%, respectively; P = 0.047), and multivariate analysis revealed GR as an independent risk factor associated with poor overall survival. CONCLUSIONS: Patients who experienced GR after radical resection for PGC were more likely to develop recurrence and metastasis, leading to shorter survival. TG for PGC was associated with a more favorable 5-year overall survival than was PG. Thus, TG should be performed for PGC patients with tumors larger than 5 cm, T3/T4 disease or lymph node metastasis to improve their long-term survival.

MiR-143-3p controls TGF-ß1-induced cell proliferation and extracellular matrix production in airway smooth muscle via negative regulation of the nuclear factor of activated T cells 1.

MicroRNAs (miRNAs) are small noncoding RNAs that function in diverse biological processes. However, little is known about the precise role of microRNAs in the functioning of airway smooth muscle cells (ASMCs). Here, we investigated the potential role and mechanisms of the miR-143 -3p on proliferation and the extracellular matrix (ECM) protein production of ASMCs. We demonstrated that miR-143-3p was aberrantly lower in ASMCs isolated from individuals with asthma than in individuals without asthma. Meanwhile, TGF-ß1 caused a marked decrease in a time-dependent manner in miR-143-3p expression in ASMCs from asthmatics. Additionally, the overexpression of miR- 143-3p robustly reduced TGF-ß1-induced ASMCs proliferation and downregulated CDK and cyclin expression, whereas the inhibition of miR-143-3p significantly enhanced ASMCs proliferation and upregulated the level of CDKs and cyclins. Re-expression of miR-143-3p attenuated ECM protein deposition reflected as a marked decrease in the expression of type I collagen and fibronectin, whereas miR-143-3p downregulation caused an opposite effect on the expression of type I collagen and fibronectin. Moreover, qRT-PCR and western blot analysis indicated that miR-143-3p negatively regulated the expression of nuclear factor of activated T cells 1 (NFATc1). Subsequent analyses demonstrated that NFATc1 was a direct and functional target of miR-143-3p, which was validated by the dual luciferase reporter assay. Most importantly, the overexpression of NFATc1 effectively reversed the inhibition of miR-143-3p on TGF-ß1-induced proliferation, and strikingly abrogated the effect of miR-143-3p on the expression of CDK4 and Cyclin D1. Together, miR-143-3p may function as an inhibitor of asthma airway remodeling by suppressing proliferation and ECM protein deposition in TGF-ß1-mediated ASMCs via the negative regulation of NFATc1 signaling, suggesting miR-143-3p as a potential therapeutic target for asthma.

Detection of SNCA and FBN1 methylation in the stool as a biomarker for colorectal cancer.

AIM: We examined the methylation status of SNCA and FBN1 genes in patients' paired tissue and stool samples for detection of colorectal cancer (CRC). PATIENTS AND METHODS: 89 DNA tissue samples (normal/cancer) and corresponding stool samples were analyzed in our study. In addition, 30 stool samples were collected as healthy controls. RESULTS: The methylation level of those samples was measured by methylation-specific polymerase chain reaction (MSP). The result shows that compared with the paired controls, both SNCA and FBN1 were significantly hypermethylated in CRC patients in tissue samples (P < 0.001). In the stool samples, hypermethylated SNCA and FBN1 were detected to be significantly higher than that in normal stool samples (P < 0.001). The combined sensitivity of at least one positive among the two markers in stool samples was 84.3%, with a specificity of 93.3%. In addition, our experiment suggested that the positive rates of SNCA and FBN1 in Dukes A stage were significantly higher than that of FOBT (P = 0.039; P = 0.006, resp.). CONCLUSION: We concluded that methylation testing of SNCA and FBN1 genes in stool sample may offer a good alternative in a simple, promising, and noninvasive detection of colorectal cancer.

Detection of miR-34a and miR-34b/c in stool sample as potential screening biomarkers for noninvasive diagnosis of colorectal cancer.

Explore potential screening biomarkers for noninvasive diagnosis of colorectal cancer (CRC) by testing methylation of the miR-34a and miR-34b/c promoter in CRC patients' tissue and stool samples. Methylation-specific PCR analyses were performed on sample DNAs: 82 pairs of normal/cancer samples, 82 CRC patients' stool samples, 40 healthy volunteer stool samples, and 20 healthy volunteer blood samples were recruited. miR-34a has been found methylated in 65 of 82 (79.3%) the CRC tissue samples, but only 36 of 82 (43.9%) in corresponding normal samples. And when testing miR-34a in stool, 63 of 82 (76.8 %) CRC stool samples were observed methylated, and 2 of 40 (5%) healthy samples were observed methylated. The methylation for miR-34b/c has been found in 80 of 82 (97.5%) CRC tissue samples, 49 of 82 (59.8%) corresponding CRC normal samples, and 74 of 79 (93.6%) CRC stool samples. Yet we did not detect any methylation from healthy volunteers stool samples or healthy adult blood samples. Results indicated 76.8 % sensitivity and 93.6% specificity of the miR-34a methylation test for detecting CRC using stool samples. Meanwhile, the sensitivity and specificity of miR-34b/c were 95 and 100%, respectively. Moreover, our results revealed that abnormal DNA methylation of miR-34a was correlated with lymph metastasis (P = 0.010). Abnormal methylation of miR-34a and miR-34b/c genes might be regarded as potential biomarkers for noninvasive screening and diagnosis of colorectal cancer.

Proliferation enhanced by NGF-NTRK1 signaling makes pancreatic cancer cells more sensitive to 2DG-induced apoptosis.

Rapidly proliferating cancer cells rely on increased glucose consumption for survival. The glucose analog 2-deoxy-D-glucose (2DG) cannot complete glycolysis and inhibits the growth of many types of cancers. It is unknown whether reduced glycolysis inhibits the growth of pancreatic cancer. Activation of nerve growth factor (NGF)-neurotrophic tyrosine kinase receptor type 1 (NTRK1) signaling leads to enhanced proliferation of these cells. We investigated the effect of 2DG treatment on the viability of NTRK1-transfected pancreatic cancer cells. After treatment with 2DG, the viability of pancreatic cancer cells was evaluated by MTT assay. SB203580 (a specific inhibitor of the p38-MAPK pathway) and PD98059 (an MAP2K1 [mitogen-activated protein kinase kinase 1, previously, MEK1] inhibitor) were used to inhibit p38-MAPK and ERKs, respectively. The percentage of apoptotic cells was determined by flow cytometry. Overexpression of NTRK1 in pancreatic cancer cells resulted in increased cell proliferation, which was reduced by PD98059-mediated inhibition of ERKs but not by suppression of p38-MAPK with SB203580. After treatment with 2DG, the percentage of apoptotic cells was greater in those with high expression of NTRK1 than in cells with low NTRK1 expression. Blocking the p38-MAPK pathway with SB203580 effectively abolished the apoptosis induced by 2DG. We conclude that pancreatic cancer cells with a high expression of NTRK1 are more sensitive to 2DG-induced apoptosis, through the p38-MAPK pathway.

Detection of hypermethylated spastic paraplegia-20 in stool samples of patients with colorectal cancer.

BACKGROUND: Analysis of aberrant hypermethylation in stool DNA might provide a novel strategy for noninvasive detection of colorectal cancer. AIMS: To explore the feasibility of detecting hypermethylation in Spastic paraplegia-20 promoter as a stool-based DNA marker for detection of colorectal cancer. METHODS: We collected 96 tissue and stool samples from patients with colorectal cancer and 30 stool samples healthy individuals. RESULTS: Hypermethylated Spastic paraplegia-20 occurs in 85.4% (82/96) of patients with colorectal cancer in the tissue samples. In the stool samples, the results indicate 80.2% (77/96) sensitivity and 100% (30/30) specificity of the test for detecting colorectal cancer by using the stool samples as a noninvasive method. CONCLUSIONS: The study reveals that hypermethylation in Spastic paraplegia-20 promoter is a highly specific and sensitive biomarker for screening colorectal cancer in stool samples as a noninvasive method.

Identification of novel low molecular weight serum peptidome biomarkers for non-small cell lung cancer (NSCLC).

AIM: To identify discriminating protein patterns in serum samples among non-small cell lung cancer (NSCLC), chronic obstructive pulmonary disease (COPD), pneumonia, and healthy controls. To discover specific low molecular weight (LMW) serum peptidome biomarkers and establish a diagnostic pattern for NSCLCby using proteomic technology. METHODS: We used magnetic bead-based separation followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify patients with NSCLC, COPD, and pneumonia. A total of 154 serum samples were analyzed in this study, among which there were 60 serum samples from NSCLC patients, 30 from patients with other lung-related diseases (16 pneumonia patients and 14 patients with COPD) as disease controls, and 64 from healthy volunteers as healthy control. The mass spectra, analyzed using ClinProTools software, distinguished between cancer patients and healthy individuals based on GA algorithm model. RESULTS: In this study, we generated numerous discriminating m/z peaks as well as disease-specific discrimination peaks. A set of five potential biomarkers (m/z: 7,763.24, 1,012.61, 4,153.16, 1,450.55, and 2,878.89) could be used as the diagnostic biomarkers to distinguish NSCLCpatients from healthy controls. In the training set, patients with NSCLC could be identified with sensitivity of 97.5% and specificity of 98.8%. Similar results were obtained in the testing set, showing 80.7% sensitivity and 91.2% specificity. CONCLUSION: Our study demonstrated that a combined application of magnetic beads with MALDI-TOF MS technique was suitable for identification of serum biomarkers for NSCLC.

[Biological behaviour of colon cancer cells transfected with C-erbB2 shRNA plasmid].

AIM: To study the changes of the cell growth, cell cycle distribution and cell apoptosis of colon cancer cell, HT-29, when C-erbB2 gene was knockdown by shRNA against C-erbB2. METHODS: Cell growth, cell cycle distribution and cell apoptosis were compared among three groups including plasmid experimental group(PEG), transfected reagent control group(TRCG)and negative plasmid control group(NPCG). Cell growth was measured by MTT assay. Cell cycle distribution and cell apoptosis were detected by flow cytometry. RESULTS: The inhibition rate of cell growth of PEG, TRCG and NPCG were 39.65%, 7.23% and 8.05% respectively. The cell growth was significantly inhibited in PEG(P<0.01). The cells of G0/G1 phase were 74.93%, 67.19%, 68.05% respectively in PEG, TRCG and NPCG. The cells of G0/G1 phase in PEG were significantly more than those in TRCG and NPCG(P<0.05).While the cells of S phase were 7.81%, 14.02%, 13.70% in PEG, TRCG and NPCG respectively. The cells of S phase in PEG were significantly less than those in TRCG or NPCG(P<0.05).The cell apoptosis rate were 19.21%, 3.13%, 4.08% in PEG, TRCG and NPCG respectively. The cell apoptosis rate in PEG was significantly higher than those in TRCG or NPCG(P<0.01). CONCLUSION: Cell growth was inhibited by shRNA against C-erbB2 gene. Cell cycle was blocked in G0/G1 phase and apoptosis was induced by C-erbB2 shRNA. This indicates C-erbB2 gene plays important roles in the carcinogenesis and development of colon cancer.

[Responses of pancreatic cancer cells to stimulations by nerve growth factor and the role of Trk-A expression].

OBJECTIVE: To study the responses of different pancreatic cancer cells to stimulations by nerve growth factor (NGF) and explore the role of Trk-A in such responses. METHODS: Five pancreatic cancer cell lines (MIA-PaCa-2, PANC-1, SW-1990, AsPC-1, and BxPC-3) were exposed to different concentrations of NGF (0, 4, 20, 100, and 500 ng/ml). MTT and Matrigel invasion method were used to observe the changes in the cell proliferation and invasion ability. Trk-A expression in these cells was detected by PCR and Western blotting, and the relations of Trk-A expression to the cell proliferative and invasive abilities following NGF treatment were analyzed. RESULTS: NGF at 100 ng/ml most obviously stimulated the cell proliferation, and PANC-1 cells showed the highest while AsPC-1 cells showed the least sensitivity to 100 ng/ml NGF stimulation. Matrigel invasion test showed that NGF enhanced the invasiveness of PANC-1 and MIA-PaCa-2 cells but produced only limited effect on AsPC-1 cells; the effect of NGF was completely inhibited by the Trk-A inhibitor CEP701. The expression levels of Trk-A mRNA and protein were the highest in PANC-1 cells and the lowest in AsPC-1 cells. CONCLUSION: NGF can enhance the proliferation and invasiveness of pancreatic cancer cells, and this effect is possibly mediated by Trk-A protein.

Serum peptidome profiling in patients with gastric cancer.

To identify discriminating protein patterns in serum samples between gastric cancer patients (early and advanced stages) and healthy controls. We used magnetic bead-based separation followed by matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) to identify patients with gastric cancer. In total, serum samples from 62 gastric cancer patients (32 in the training set and 30 in the test set; 19 of which had early-stage tumors and 43 of which had advanced-stage tumors) and 64 healthy controls (32 in the training set and 32 in the test set) were analyzed. The mass spectra, analyzed using ClinProTools software, distinguished between cancer patients and healthy individuals based on three different algorithm models. In the training set, patients with gastric cancer could be identified with a mean sensitivity of 94.7% and a mean specificity of 99%. Similar results were obtained with the test set, showing 79.3% sensitivity and 86.5% specificity. Our study demonstrates the high sensitivity and specificity of screening serum protein patterns using MALDI-TOF MS for the identification of patients with gastric cancer.

RNAi-mediated ERBB2 gene knockdown sensitizes human colorectal cancer cells to radiation.

This study aimed to investigate the involvement of c-erbB-2, encoded by the receptor tyrosine kinase ERBB2 gene, in the pathogenesis of colorectal cancer and to validate its potential as an anticancer target. Immunohistochemical and histopathological analyses were applied in tissue samples derived from 80 colorectal cancer patients. ERBB2 stable small hairpin RNA (shRNA) knockdown in HT29 human colorectal cancer cells was confirmed by RT-PCR and western blotting. Cell cycle profile and apoptosis were measured using PI or Annexin V-PI dual staining. A significant correlation between ERBB2 levels and Dukes' stage of colorectal cancer, in both the primary malignancy and lymph node metastatic tissues, was observed. ERBB2-depleted HT-29 cells exhibited increased sensitivity to radiation compared to control cells, likely due to enhanced G0/G1 phase cell cycle arrest and apoptosis. ERBB2 may be involved in the malignancy and metastasis of colorectal cancer. Overexpressed ERBB2 may constitute a potential target for colorectal cancer therapy.

[Vitexicarpin affects proliferation and apoptosis in mutated p53 breast cancer cell].

OBJECTIVE: To elucidate the effect of proliferation and apoptosis induced by vitexicarpin in mutated p53 Hs578T cell line and study the expression of c-Myc, p21 and Bcl-2 protein in Hs578T and wild p53 MCF-7 cell pre-treated with vitexicarpin. METHODS: Cells were treated with various concentrations of vitexicarpin (0, 0.1, 0.2, 0.5, 1.0 micromol/L). MTT assays were used to detect cell proliferation at different time points with different doses of vitexicarpin. TUNEL assays were performed to examine apoptosis in cells pretreated with vitexicarpin. The authors detected three main proteins involved in apoptosis: c-Myc, bcl-2 and p21 protein in various concentrations of vitexicarpin-treated cells. To understand the function of c-Myc protein in the effect of vitexicarpin, the authors transiently transfected c-Myc protein in Hs578T cell and detected the cellular effect of vitexicarpin. RESULTS: Proliferation of Hs578T and MCF-7 cells were inhibited markedly by vitexicarpin at concentrations above 0.2 micromol/L (IC50 = 0.25 micromol/L and 0.53 micromol/L at 72 h respectively). TUNEL assays revealed that the rates of TUNEL positive cells were 10.15%, 27.33% and 35.34% when exposing Hs578T cells to 0.1, 0.2 and 0.5 micromol/L of vitexicarpin respectively. In control cells, the rates of TUNEL positive cells were 4.65%. Cells pretreated with higher concentrations of vitexicarpin expressed less c-Myc and Bcl-2 in Hs578T cells.In contrast, p21 decreased when cells were treated with the same conditions. When c-Myc transient transfection was performed in vitexicarpin-treated cells, the effect of p21 and Bcl-2 disappeared. The proliferative function of vitexicarpin declined in Hs578T/c-Myc cells. When treated with 0.5 micromol/L vitexicarpin, A value increased 1.53 times at 72 h. Conversely, A value decreased 48% at the same condition in MCF-7/c-Myc cells. CONCLUSION: The suppressing mechanism of vitexicarpin for malignant tumors is through c-Myc in p53 mutated Hs578T cells. And it is multi-directional and varies in different cells.

Decreased mitochondrial DNA content in blood samples of patients with stage I breast cancer.

BACKGROUND: Alterations of mitochondrial DNA (mtDNA) have been implicated in carcinogenesis. We developed an accurate multiplex quantitative real-time PCR for synchronized determination of mtDNA and nuclear DNA (nDNA). We sought to investigate whether mtDNA content in the peripheral blood of breast cancer patients is associated with clinical and pathological parameters. METHODS: Peripheral blood samples were collected from 60 patients with breast cancer and 51 age-matched healthy individuals as control. DNA was extracted from peripheral blood for the quantification of mtDNA and nDNA, using a one-step multiplex real-time PCR. A FAM labeled MGB probe and primers were used to amplify the mtDNA sequence of the ATP 8 gene, and a VIC labeled MGB probe and primers were employed to amplify the glyceraldehyde-3-phosphate-dehydrogenase gene. mtDNA content was correlated with tumor stage, menstruation status, and age of patients as well as lymph node status and the expression of estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu protein. RESULTS: The content of mtDNA in stage I breast cancer patients was significantly lower than in other stages (overall P = 0.023). Reduced mtDNA was found often in post menopausal cancer group (P = 0.024). No difference in mtDNA content, in regards to age (p = 0.564), lymph node involvement (p = 0.673), ER (p = 0.877), PR (p = 0.763), and Her-2/neu expression (p = 0.335), was observed. CONCLUSION: Early detection of breast cancer has proved difficult and current detection methods are inadequate. In the present study, decreased mtDNA content in the peripheral blood of patients with breast cancer was strongly associated with stage I. The use of mtDNA may have diagnostic value and further studies are required to validate it as a potential biomarker for early detection of breast cancer.

[Construction and identification of CerbB-2 siRNA expression plasmid and its transfer into human colon cancer cell lines HT-29].

OBJECTIVE: To construct a plasmid carrying small interfering RNA (siRNA) targeting human C-erbB2 gene (pGenesil- erbB2) and test its effect on Her-2 expression at the post-transcriptional level in human colon cancer cell lines HT-29 cells that highly express erbB2. METHODS: A HT-29 cell line that highly expressed CerbB-2 was selected using immunohistochemical method. The double-stranded siRNA targeting human CerbB-2 cDNA and the negative control fragment were cloned into pGenesil-1 vector, and after identification and sequence analysis, the constructed pGenesil-erbB2 plasmid was transfected into the selected HT-29 cell line. RESULTS: The pGenesil-erbB2 plasmid was successfully constructed and stably transferred into HT-29 cells. The transfection resulted in significant inhibition of Her-2 protein expression in the HT-29 cells, as shown by Western blotting. CONCLUSION: The pGenesil-erbB plasmid we constructed can be stably transfected into HT-29 cells to inhibit the expression of Her-2 protein, and can be useful in further studies of increasing the radiosensitivity of HT-29 cell lines.