The role of EGFR MAbs C225 in breast cancer stem cells

e22093

Background: The epithermal growth factor receptor(EGFR) signaling pathways has been implicated in self-renewal of breast cancer stem cells. It has been proved that the EGFR tyrosine kinase inhibitor-gefitinib significantly decreased the mammosphere- forming efficiency(MFE) in ductal carcinoma in situ (DCIS) derived cancer cells. We investigated the response of breast cancer stem cells in breast cancer cell line MCF-7 to EGFR MAbs C225(cetuximab). Methods: Cells were used for nonadherent (i.e.,mammosphere) culture and were divided into four groups according to the different culture medium whether or not including exogenous EGF and MAbs C225. MFE was calculated as the number of mammospheres (≥60um) and was expressed as a percentage. We Compared the percentage of CD44+/CD24- cells from the four groups, and measured the levels of the Wnt and Notch-3 gene expression of the four groups. Results: There was no significant difference of MFE between groups. In the presence of exogenous EGF, MAbs C225 significantly decreased the MFE and the percentage of CD44+/CD24- cells of mammospheres compared with exogenous EGF alone(0.7% versus 1.5%, P < 0.001 and 4% versus 11%P < 0.001;respectively). In the absence of exogenous EGF, MAbs C225 aslo statistically decreased the MFE and the percentage of CD44+/CD24- cells of mammospheres compared with that of lacking exogenous EGF and MAbs C225(0.53% versus 1.3%,P = 0.003 and 9% versus 3%, P < 0.01;respectively). And we observed that the Notch-3 gene expression was compensativly increased in the two groups of addition of MAb C225. No significant differences of Wnt gene expression were observed between groups. Conclusions: EGFR MAbs C225 could disrupt mammoshpere formation and decrease the percentage of CD44+/CD24- cells of mammoshpere cells. The expression of Notch-3 is increased with the EGFR antagonistics in breast cancer stem cells.

No significant financial relationships to disclose.

Gefitinib versus platinum contained doublet chemotherapy in chemotherapy-naive patients with stage IIIb or IV non-small cell lung cancer of adenocarcinoma histology: A retrospective case control study

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Background: The results of the ISEL study in non-small cell lung cancer (NSCLC) suggest greater benefit of gefitinib among Asian patients and non-smokers compared with the overall trial population. Methods: We conducted a retrospective case-control study to compare outcomes for gefitinib versus platinum doublet chemotherapy as first line treatment in selected NSCLC patients (stage IIIB/IV adenocarcinoma, PS 0–2). Patient receiving platinum chemotherapy were selected on the basis of disease stage (IIIB or IV), gender, smoking history, WHO performance status (PS) (0–1, or 2) and age (< 60ys or ≥ 60ys) being matched to patients receiving gefitinib. Gefitinib and chemotherapy arm patients were selected by 1:2 ratio in order to increase statistical power. The study was approved by local institute review board. Results: 99 chemo-naïve adenocarcinoma patients treated in our institute from January 2006 to December 2007 were collected: 33 received gefitinib and 66 received chemotherapy. The baseline characteristics are listed in table 1 . The median duration of follow-up was 10 months. Patients receiving gefitinib experienced significantly higher ORR and DCR, and prolonged PFS ( table 1 ). Patients receiving chemotherapy experienced more frequent grade 3–4 neutropenia (42.4% vs 0%), thrombocytopenia (21.2% Vs 0%), febrile neutropenia (7.5% vs 0%) and nausea (24.2% vs 3.0%). The most commonly recorded adverse events in the gefitinib arm were rash/acne (9.1%), diarrhea (3.0%), nausea (3.0%) and anemia (3.0%). Conclusions: The limitations of case-control studies are acknowledged, yet these results were supported by IPASS. Gefitinib as first-line treatment confers clinically relevant benefit in Asian NSCLC patients with adenocarcinoma histology versus platinum based chemotherapy.

[Table: see text]

[Table: see text]

Role of E1B protein-dificient oncolytic virus in breast cancer stem cells

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Background: Cancer stem cells have been indicated in the initiation of tumors and are even found to be responsible for relapses after apparently curative therapies have been undertaken. In breast cancer, they may reside in the CD44+CD24−/low population. Oncolytic adenoviruses enter cells through infection and can kill both proliferating and quiescent cells. We investigated the role of E1B protein- dificient oncolytic adenovirus in breast cancer stem cells. Methods: MCF-7 cells were infected by E1B protein-dificient oncolytic adenovirus as infected group (MOI=100) and cultured routinely as control group simultaneously. The proportion of CD44+CD24- cells was assessed by flow cytometry (FCM) in two groups respectively. Meanwhile, mammosphere culture was done in two groups' cells to observe the size and number of mammospheres, calculate the mammosphere- forming efficiency (MFE). The proportion of CD44+CD24- cells in two groups' mammospheres was assessed by FCM. Results: The percentages of CD24-,CD44+, CD44+CD24- in the infected gruop were 43.9%, 63.26%, 22.19%, respectively. While in the control group, the percentages were 6.74%, 88.30%, 2.30%. In the infected group, the time of mammosphere's formation was earlier, the volumes of mammospheres were bigger and the MFE was higher than the control group (1.26%:0.9%). In two mammospheres' groups, the proportion of CD44+CD24- cells in experiment group and control group was 38.08% and 23.35%, respectively. Conclusions: E1B protein-dificient oncolytic adenovirus can kill MCF-7 cells in short time, mainly breast cancer differentiated cells. It maybe promote the growth of the breast cancer stem cells. It maybe accelerate the speed of self-renewed and differentiation of the breast cancer stem cells.

No significant financial relationships to disclose.

The biological characteristics of human third trimester amniotic fluid stem cells

Third trimester amniotic fluid (AF)-derived human mesenchymal stem cells (MSCs) can be greatly expanded in vitro and induced to differentiate into multiple mesenchymal cell types. This study aimed to investigate the biological characteristics of MSCs from third trimester AF as a new source of therapeutic stem cells. Forty third trimester AF samples were obtained from healthy women who underwent elective caesarean section for breech presentation. A simple culture protocol for MSCs was used. A cell growth curve was drawn, and cell surface antigens and cytokines were analysed by immunofluorescent staining, reverse transcription-polymerase chain reaction and flow cytometry. MSCs from third-trimester AF were successfully isolated, cultured and enriched. MSCs expanded extensively without feeders, they were not tumourigenic and were induced to differentiate into osteocytes. Surface antigens were analysed and found to express the pluripotency marker Oct-4. Considering the great feasibility of biomedical engineering using MSCs, third trimester AF may provide a rich source for investigation of human MSCs.

Pre-transplantation glucose testing for predicting new-onset diabetes mellitus after renal transplantation

AIM

New-onset diabetes after renal transplantation (NODAT) adversely affects graft and patient survival. However, NODAT risk based on pre-transplant blood glucose (BG) levels has not been defined. Our goal was to identify the best pre-transplant testing method and cut-off values.

MATERIALS AND METHODS

We performed a case-control analysis of non-diabetic recipients who received a live donor allograft with at least 6 months post-transplant survival. Pre-transplant glucose abnormalities were excluded through 75 g oral glucose tolerance testing (OGTT) and random BG (RBG) measurement. NODAT was defined based on 2003 Canadian Diabetes Association criteria. Multivariate logistic and Cox regression analysis was performed to determine independent predictor variables for NODAT. Receiver-operating-characteristic (ROC) curves were constructed to determine threshold BG values for diabetes risk.

RESULTS

151 recipients met initial entry criteria. 12 had pre-transplant impaired fasting glucose and/or impaired glucose tolerance, among who 7 (58%) developed NODAT. In the remaining 139, 24 (17%) developed NODAT. NODAT risk exceeded 25% for those with pre-transplant RBG > 6.0 mmol/l and 50% if > 7.2 mmol/l. Pre-transplant RBG provided the highest AUC (0.69, p = 0.002) by ROC analysis. Increasing age (p = 0.025), acute rejection (p = 0.011), and RBG > 6.0 mmol/l (p = 0.001) were independent predictors of NODAT.

CONCLUSION

Pre-transplant glucose testing is a specific marker for NODAT. Patients can be counseled of their incremental risk even within the normal BG range if the OGTT is normal.

Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

A nonlinear mixed-effect mixture model for functional mapping of dynamic traits

Functional mapping has emerged as a next-generation statistical tool for mapping quantitative trait loci (QTL) that affect complex dynamic traits. In this article, we incorporated the idea of nonlinear mixed-effect (NLME) models into the mixture-based framework of functional mapping, aimed to generalize the spectrum of applications for functional mapping. NLME-based functional mapping, implemented with the linearization algorithm based on the first-order Taylor expansion, can provide reasonable estimates of QTL genotypic-specific curve parameters (fixed effect) and the between-individual variation of these parameters (random effect). Results from simulation studies suggest that the NLME-based model is more general than traditional functional mapping. The new model can be useful for the identification of the ontogenetic patterns of QTL genetic effects during time course.

Molecular characterization of drug-resistant mycobacterium tuberculosis isolates from Sichuan Province in china

Tuberculosis is still a severe public health issue in eastern Asia, and Sichuan is the key area for tuberculosis control in China. To determine the phenotypic and mutation patterns of drug resistance in Mycobacterium tuberculosis isolates from Sichuan, the drug susceptibility of 198 clinical isolates was examined. Among these isolates, 76 drug-resistant and 20 susceptible isolates were analyzed for the rpoB, embB, and katG and inhA regulatory regions. These are mutations believed to associate with rifampin (RIF), ethambutol (EMB), and isoniazid (INH) resistance, respectively. Of the 60 RIF-resistant isolates, 54 (90.0%) carried mutations on the amplified fragment of the rpoB gene, and the most common one (64.8%, 35/54) was at codon 531. Two new mutation patterns were recognized: one isolate harbored three mutations at codons 511, 516, and 518, and the other carried the dual mutation GAChACC at codon 516. A total of 30 INH-resistant isolates (60.0%, 30/50) had mutations at codon 315, whereas 4 (8.0%) had mutations at the inhA regulatory region. Among the 46 EMB-resistant isolates, 22 harbored the Met306 mutation. The results showed geographical variation in the mutation types of drug-resistant genes in M. tuberculosis isolates from Sichuan; this finding is valuable for the development of targeted and rapid molecular diagnostic methods suitable for specific regions.

Second-trimester fetal growth and the risk of poor obstetric and neonatal outcomes

OBJECTIVE

To compare outcomes of fetuses with an estimated fetal weight (EFW) < 25(th) percentile in the second trimester to those in fetuses with EFW >or= 25(th) percentile in the second trimester.

METHODS

We compared outcomes of 252 pregnancies with an EFW < 25(th) percentile at 18-24 weeks' gestation with those of 265 controls. All pregnancies had early dating by ultrasonography. We excluded fetuses with aneuploidy, major malformations, second-trimester rupture of membranes, and multiple pregnancies.

RESULTS

Second-trimester EFW < 25(th) percentile was significantly associated with higher rates of fetal or neonatal death, third-trimester small for gestational age (SGA), Doppler abnormalities, indicated preterm birth, gestational hypertension or pre-eclampsia before labor, lower birth weight, birth weight < 10(th) percentile, birth weight < 5(th) percentile, and admission to the neonatal intensive care unit. Many of these associations remained even after excluding patients with oligohydramnios, fetal echogenic bowel, and growth asymmetry.

CONCLUSION

Second-trimester SGA, as defined by an EFW < 25(th) percentile using current growth curves, is associated with poor obstetric and neonatal outcomes. Increased surveillance of such pregnancies may be necessary.

Pharmacokinetic characterization of hydroxylpropyl-beta-cyclodextrin-included complex of cryptotanshinone, an investigational cardiovascular drug purified from Danshen (Salvia miltiorrhiza)

1. The study aimed to investigate the pharmacokinetics of cryptotanshinone in a hydroxylpropyl-beta-cyclodextrin-included complex in dogs and rats. 2. Animals were administrated the inclusion complex of cryptotanshinone and the concentrations of cryptotanshinone and its major metabolite tanshinone IIA were determined by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. 3. Cryptotanshinone in inclusion complex was absorbed slowly after an oral dose, and the C(max) and AUC(0-)(t) were dose-proportional. The bioavailability of cryptotanshinone in rats was (6.9% +/- 1.9%) at 60 mg kg(-1) and (11.1% +/- 1.8%) in dogs at 53.4 mg kg(-1). The t(1/2) of the compound in rats and dogs was 5.3-7.4 and 6.0-10.0 h, respectively. Cryptotanshinone showed a high accumulation in the intestine, lung and liver after oral administration, while the lung, liver and heart had the highest level following intravenous dose. Excretion data in rats showed that cryptotanshinone and its metabolites were mainly eliminated from faeces and bile, and the dose recovery rate was 0.02, 2.2, and 14.9% in urine, bile, and faeces, respectively. 4. The disposition of cryptotanshinone in an inclusion complex was dose-independent and the bioavailability was increased compared with that without cyclodextrin used to formulate the drug. Cryptotanshinone was distributed extensively into different organs. Excretion of cryptotanshinone and its metabolites into urine was extremely low, and they were mainly excreted into faeces and bile.

Preclinical factors affecting the pharmacokinetic behaviour of tanshinone IIA, an investigational new drug isolated from Salvia miltiorrhiza for the treatment of ischaemic heart diseases

Tanshinone IIA (TSIIA) is a major active triterpenoid isolated from Salvia miltiorrhiza. The purposes of this study were to investigate various preclinical factors that determined the pharmacokinetics of TSIIA. After oral dosing at 6.7, 20, and 60 mg kg(-1), TSIIA was detected mainly as glucuronidated conjugate (TSIIAG) with only small amounts of the unchanged in the plasma. TSIIA was predominantly excreted into the bile and faeces as TSIIAG, and urine to a minor extent. The C(max) and AUC(0-)(t) of TSIIAG after i.p. administration were significantly lower than those after intragastric administration. The plasma concentration-time profiles of TSIIA following oral dosing of TSIIA showed multiple peaks. The C(max) and AUC(0-)(t) of TSIIA and its glucuronides in rats with intact bile duct were significantly lower than those of rats with bile duct cannulation. Studies from the linked-rat model and intraduodenal injection of bile containing TSIIA and its metabolites indicate that TSIIA glucuronides underwent hydrolysis and the aglycone was reabsorbed from the gut and excreted into the bile as conjugates. TSIIA had a wide tissue distribution, with a very high accumulation in the lung, but very limited penetration into the brain and testes. TSIIA was metabolized by rat CYP2C, 3A and 2D, as ticlopidine, ketoconazole and quinidine all inhibited TSIIA metabolism in rat liver microsomes. Taken collectively, these findings indicate that multiple factors play important roles in determining the pharmacokinetics of TSIIA.

Systemic hemodynamic and regional blood flow changes in response to chronic reductions in uterine perfusion pressure in pregnant rats

Preeclampsia (PE) is associated with increased total peripheral resistance (TPR), reduced cardiac output (CO), and diminished uterine and placental blood flow. We have developed an animal model that employs chronic reductions in uterine perfusion pressure (RUPP) in pregnant rats to generate a “preeclamptic-like” state during late gestation that is characterized by hypertension, proteinuria, and endothelial dysfunction. Although this animal model has many characteristics of human PE, the systemic hemodynamic and regional changes in blood flow that occur in response to chronic RUPP remains unknown. Therefore, we hypothesized that RUPP would decrease uteroplacental blood flow and CO, and increase TPR. Mean arterial pressure (MAP), CO, cardiac index (CI), TPR, and regional blood flow to various tissues were measured using radiolabeled microspheres in the following two groups of conscious rats: normal pregnant rats (NP; n = 8) and RUPP rats ( n = 8). MAP was increased (132 ± 4 vs. 99 ± 3 mmHg) in the RUPP rats compared with the NP dams. The hypertension in RUPP rats was associated with increased TPR (2.15 ± 0.02 vs. 0.98 ± 0.08 mmHg·ml−1·min−1) and decreased CI (246 ± 20 vs. 348 ± 19 ml·min−1·kg−1, P < 0.002) when contrasted with NP dams. Furthermore, uterine (0.16 ± 0.03 vs. 0.38 ± 0.09 ml·min−1·g tissue−1 ) and placental blood flow (0.30 ± 0.08 vs. 0.70 ± 0.10 ml·min−1·g tissue−1) were decreased in RUPP compared with the NP dams. These data demonstrate that the RUPP model of pregnancy-induced hypertension has systemic hemodynamic and regional blood flow alterations that are strikingly similar to those observed in women with PE.

Retrospective analysis of phosphorylation status of the estrogen receptor in patients with early stage disease

21034

Background: The AKT kinase, when phosphorylated to its activated form (pAKT), mediates many proliferative and survival effects of growth factor receptors such as members of the epidermal growth factor receptor (EGFR) family. Overexpression of AKT in breast neoplasms suggests that AKT activation is involved in breast cancer development and/or progression, and contributes to poor outcome. pAKT is frequently upregulated in Her-2/neu positive breast cancers. Activated AKT is able to phosphorylate in vitro serine 167 (pS167) of estrogen receptor alpha (ERa), resulting in ER-mediated transcriptional activity in the absence of estrogen and possibly contributing to tamoxifen resistance in ERa positive breast cancers. In addition, ERa is phosphorylated at S118 (pS118) by MAPK. Thus, it is possible that pAKT- mediated ERa phosphorylation is implicated in tumorigenesis and resistance to treatment with hormonal therapy in patients with breast cancer. Methods: Utilizing commercially available antibodies, IHC analysis of 125 paraffin-embedded, ERa positive, early breast cancer cases, stratified for stage, were tested for pAKT, PTEN, pS167, and pS118. Staining intensity and number of positive cells were assessed by 4 independent graders. Fisher's exact test was used to determine the significance of associations with a two-sided type I error of 5%. Results: Phosphorylation of AKT occurred in approximately one-half of cases. pS167 was phosphorylated in 66% of pAKT positive cases compared to 35% of pAKT negative cases (p<0.0001). When we analyzed nuclear pAKT staining, this association was more pronounced: 76% of pAKT(+) vs. 37% of pAKT(-) (p<0.0001). 69% of pS118(+) cases were pS167(+) compared to only 15% pS167(+) when pS118 was negative (p<0.0001). In approx. 32% of cases pAKT was present in both the cytoplasm and nucleus. 20% of samples had only cytoplasmic pAKT, while in 4% of cases pAKT was nuclear only, supporting the hypothesis that cytoplasmic phosphorylation of AKT may precede nuclear accumulation. Conclusions: Phosphorylation of pS167ERa is significantly associated with AKT activation (especially in the nucleus) in early breast cancer, supporting the hypothesis that these two events may be causally linked and contribute to breast cancer pathogenesis.

No significant financial relationships to disclose.

Mast cell deficient W/Wv mice have lower serum IL-6 and less cardiac tissue necrosis than their normal littermates following myocardial ischemia-reperfusion

Myocardial ischemia-reperfusion (IR) injury complicates all forms of coronary artery revascularization. Circulating interleukin-6 (IL-6) has been implicated in cell death following a variety of stimuli. Macrophages, platelets, neutrophils and the endothelium have been shown to release IL-6 after IR injury. Cardiac mast cells have been implicated in IR; however, their involvement has never been quantified. In this randomized, prospective study, we compared cardiac tissue susceptibility and serum IL-6 changes between mast cell deficient (W/Wv) mice and their normal littermates (+/+). Twenty-eight male W/Wv mice (n=14) and their +/+ littermates (n=14) were anaesthetized with 2.5% isoflurane. The left coronary artery (LCA) was ligated for 30 minutes or a sham procedure was performed. After 6 hours of reperfusion, the animals were sacrificed. The muscle viability was assessed on fresh whole-mount slices by nitroblue tetrazolium (NBT) histochemical assay and serum IL-6 concentrations measured by ELISA. Cardiac muscle viability was significantly higher in W/Wv mice than the +/+ mice. Serum IL-6 levels were higher in the +/+ sham mice (465 +/- 32 pg/ml, n=6) than the W/Wv mice (185 +/- 31 pg/ml, n=6), p < 0.001. The IL-6 levels increased significantly after reperfusion only in the +/+ mice (698 +/- 41 pg/ml, n=8, p = 0.001), while it remained similar in the W/Wv mice (202 +/- 48 pg/ml, n=8, p = 0.783). These results show that the absence of mast cells reduces the myocardial damage associated with IR injury. Furthermore, there is an attenuation in the inflammatory response, as measured by serum IL-6 levels, following this local insult. This finding entertains the prospect of developing prophylactic therapy--targeting selective inhibition of cardiac mast cell activation, in clinical situations involving medical or surgical myocardial revascularization.