A novel mutant-enriched liquidchip for detection of circulating EGFR mutations in advanced non-small cell lung cancer patients

e14526

Background: We developed a novel technology, Mutant-enriched liquidchip (MEL), which integrates the sensitive mutant enriched PCR and quantitative high throughput liquidchip (suspension array), to detect circulating EGFR mutations (Exon 19 deletion and exon 21 L858R mutation) in patients with advanced non-small cell lung cancer (NSCLC). Methods: To enrich mutant EGFR, a unique restriction site is introduced into the mutation alleles so that the wild type sequence can be selectively removed by restriction digestion, and the undigested mutated DNA is amplified by PCR. The product is then hybridized to complementary probes (including 15 types of exon 19 deletion and exon 21 L858R mutation) which had been conjugated to beads coding with different fluorescent dye, followed by measuring through Luminex 200 system. Plasmid DNA mixture with different EGFR genotypes was applied to determine the sensitivity and accuracy of MEL. Afterwards, the MEL was validated in 49 patients whose EGFR genotypes of tissue specimen had been tested with direct sequencing The circulating genomic DNA was obtained from serum sample of other 201 Chinese stage IIIB or IV NSCLC patients without EGFR-TKI administration, and the EGFR mutation status was analyzed by using of MEL. Results: The results shows that MEL is capable of detecting as few as 20 copies of mutant EGFR alleles with a sensitivity limit of at least mutant/wild-type ratio of 0.1%. It also shows that MEL can not only confirm EGFR mutations status in tissue specimens already known by direct sequencing (13/49), but also detect mutations in some of those showing wild type by sequencing (16/49). Overall, 54% of patients had circulating EGFR mutation. 34% of patients had an exon 19 deletion and 29.6% had L858R. 63.1% of mutations were found in females and 67.6% in never-smokers. Conclusions: This novel MEL method allows for highly sensitive and reproducible detection of human somatic mutations in heterogeneous specimens, and could be applicable to test EGFR mutations non-invasively in advanced NSCLC patients for predicting response to targeted therapy.

No significant financial relationships to disclose.

Phase I study of chidamide (CS055/HBI-8000), a novel histone deacetylase inhibitor, in patients with advanced solid tumors and lymphomas

3529

Background: Chidamide (CS055/HBI-8000) is a new benzamide type of histone deacetylase (HDAC) inhibitor with low nanomolar activity against HDAC1, 2, 3 and 10. This Phase I study evaluated the safety and tolerability of chidamide in patients (pts) with advanced solid tumors and lymphomas. Methods: 31 pts with refractory or relapsed advanced solid tumors (22) and lymphomas (9) were enrolled in this study. Escalating doses of 5, 10, 17.5, 25, 32.5 and 50 mg Chidamide (each with 3 to 7 pts) were administered orally either twice or three times per week for 4 consecutive weeks every 6 weeks. Results: No dose limiting toxicities (DLTs) were identified in the 2 x per week cohorts (22 pts) up to 50 mg; G2 and G3 hematological toxicities (leukopenia/neutropenia and thrombocytopenia) were observed at 50 mg. DLTs were reported as G3 diarrhea or vomiting in 2 pts in the 3 x per week cohort at 50 mg. Common adverse events were G1/G2, fatigue (n = 11), thrombocytopenia (n = 9), anorexia (n = 8), nausea/vomiting (n = 7), leukopenia/neutropenia (n = 6), hypochromia (n = 6), and diarrhea (n = 5). No cystitis, pericarditis, pericardial effusion or prolonged QTc intervals were observed. Single dose PK analysis in pts with 25, 32.5 and 50 mg revealed T1/2 of 16.8–18.3 h, Tmax of 1–2 h in most cases, and a dose-related increase in Cmax and AUC. Multiple dose PK analysis in pts with 32.5 mg 3 x per week suggested drug accumulation with this regimen. Significant induction of histone (H3) acetylation was observed in peripheral white blood cells, which lasted for 2–3 days in most pts after single dosing. 25 pts with total treatment cycles of 49 (range 1–6) were evaluable for efficacy. 4 pts with T-cell lymphomas (4/5 evaluable) and 1 pt with submandibular adenoid cystic carcinoma achieved PR, and 11 pts (2 B-cell lymphomas and 9 solid tumors) experienced SD. Conclusions: Chidamide was well-tolerated in pts with advanced solid tumors and lymphomas in the tested regimens. In addition, the compound exhibited a relatively long half-life, a long-lasting biomarker response and encouraging antitumor activity at well-tolerated doses. The overall phase I results recommend the 2 x per week regimen for phase II studies.

[Table: see text]

Preoperative hepatic and regional arterial chemotherapy in the prevention of liver metastasis after colorectal cancer surgery

4090

Background: To investigate whether preoperative hepatic and regional arterial chemotherapy are able to prevent liver metastasis and improve overall survival in patients receiving curative colorectal cancer resection. Methods: Patients with Stage II or Stage III colorectal cancer (CRC) were randomly assigned to receive preoperative hepatic and regional arterial chemotherapy (PHRAC group, n=256) or surgery alone (control group, n=253). The primary endpoint was disease-free survival, whereas the secondary endpoints included liver metastasis-free survival and overall survival. Results: There were no significant differences in overall morbidity between PHRAC and Control groups. During the follow-up period (median, 42 months), the median liver metastasis time for patients with stage III CRC was significantly longer in the PHRAC group (16±3 months v.s. 8±1 months, P=0.01). In stage III patients, there was also significant difference between the two groups with regard to the incidence of liver metastasis (18.9% vs 27.3%, P=0.01), 5-year disease-free survival (70.2% vs 52.0%, P=0.0076), 5-year overall survival (80.3% vs 69.5%, P=0.020) and the median survival time (40.1± 4.6 months vs 36.3 ± 3.2 months, P=0.03). In the PHRAC arm, the risk ratio of recurrence was 0.63 (95% CI, 0.51–0.79, P=0.0001), of death was 0.50(95% CI, 0.32–0.67; P=0.005), and of liver metastasis was 0.70 (95% CI, 0.52–0.86; p=0.01). In contrast, PHRAC seemed to be no benefit for stage II patients. Toxicities, such as hepatic toxicity and leucocyte decreasing, were mild and could be cured with medicine. Conclusions: Preoperative hepatic and regional arterial chemotherapy, in combination with surgical resection, could be able to reduce and delay the occurrence of liver metastasis and therefore improve survival rate in patients with stage III colorectal cancer.

No significant financial relationships to disclose.

Pathological features of advanced gastric cancer (GC): Relationship to human epidermal growth factor receptor 2 (HER2) positivity in the global screening programme of the ToGA trial

4556

Background: HER2 positivity is thought to be a negative prognostic factor in GC, correlating with poor survival rates. Reported HER2-positivity rates in GC have varied widely (6–35%). The ToGA trial is evaluating the addition of trastuzumab (Herceptin) to chemotherapy in HER2-positive advanced GC. It is the first randomised Phase III trial to provide prospective information on HER2-positivity rates in GC. Enrollment is complete, with 3,883 patients screened in 24 countries. The pathological features of GC and the relationship with HER2 positivity will be examined. Methods: Advanced GC tumour samples were centrally screened by immunohistochemistry (IHC; HercepTest) and fluorescence in situ hybridisation (FISH; PharmDx) in parallel. A HER2-scoring system modified from the protocol in breast cancer (BC) was used: a score of IHC 3+ and/or FISH positive was defined as HER2 positive. Results: Final data showed an overall HER2-positivity rate of 22.1% evaluated from 3807 patients. The HER2-positivity rate was similar between Europe (23.6%) and Asia (23.5%). HER2-positivity rates were higher in gastro-oesophageal junction (GEJ) than stomach cancer (33.2% vs 20.9%; p<0.001) and in intestinal than diffuse/mixed cancer (32.2% vs 6.1%/20.4%; p<0.001). This is reflected in above-average HER2-positivity rates in countries with the highest GEJ:stomach cancer ratios (France 0.56 [HER2 positivity 26.9%]; Germany 0.53 [23.7%]; UK 0.33 [25.8%]) and intestinal:diffuse cancer ratios (UK 3.4 [HER2 positivity 25.8%]; Australia 2.6 [32.8%]; Japan 2.8 [27.8%]). The modified HER2-scoring system showed concordance between IHC and FISH results of 87.5%. In BC most IHC 0/1 samples are FISH negative but, in ToGA, the frequency of IHC 0/1 samples testing FISH positive was almost as high as IHC 2/FISH-positive samples (23% vs 26%). Conclusions: The overall HER2-positivity rate in advanced GC in ToGA is 22.1%. Variations in tumour location and type mostly explain the difference in HER2-positivity rates between countries. Efficacy data will enable further evaluation of the clinical significance of HER2 IHC and FISH scoring patterns.

[Table: see text]

Analysis of signal pathway activation in hepatocellular carcinoma: Association with clinical outcomes to sorafenib in Chinese patients

e15529

Background: The pathogenesis of hepatocellular carcinoma invovles multi-stage development of molecular aberrations affecting signaling pathways that regulate cancer growth and progression. Treatment strategies have focused on inhibition of the Ras effector pathway with inhibitors of Raf, such as sorafenib in HCC. Greater understanding of the cellular response to sorafenib is needed to tailor targeted therapy for individual patients and identify those more likely to benefit. Methods: We performed immunohistochemistry on a tissue microarray of tumor and adjacent liver tissue from 40 HBV-infected HCC patients who were treated with sorafenib, and 20 normal liver. We compared the levels of 8 signaling proteins including growth factor receptors (PDGFRa, VEGFR1, VEGFR2, VEGFR3, c-kit, c-met, IGF-R, EGFR), tumor suppressors (PTEN) and their downstream phosphorylated (p-) signal transducers (p-RAF, p-MEK1/2, p-ERK1/2; PI3K, p-AKT, NFkB, axin, β-catenin,p-GSK3β, p-mTOR, p-S6, p-70S6K, p-JNK, p-SRC, p-STAT3, c-fos, c-jun) in cancer cells and endothelial cells of HCC to those in non-neoplastic liver. Results: The overall profiles of signalling protein expression levels, activation states and subcellular distribution in HCC cells and endothelial cells were distinguishable from non-neoplastic hepatocytes. The ERK pathway activation was correlated with low level of nuclear β-cat and high level of p-mTOR (p<0.05). Long survival (>6m) patients were characterized by high level of nuclear pERK and low level of p-AKT, p-GSK3β (p<0.05) in tumor cells. The high microvessel density and the presence of micrometastases correlated with high level of VEGFR, p-ERK and p-SRC in endothelial cells. Conclusions: Sorafenib may affect signalling through the Ras/Raf/MAPK/ERK pathway. HBV-related HCC patients with. overactivation of signal transduction cascade MAPK/ERK and PI3K/AKT pathways in tumor cells and/or endothelial cells may benefit from the targeted treatment.

No significant financial relationships to disclose.

Retinal nerve fibre layer thickness measurement reproducibility improved with spectral domain optical coherence tomography

BACKGROUND/AIMS

To investigate retinal nerve fibre layer (RNFL) thickness measurement reproducibility using conventional time-domain optical coherence tomography (TD-OCT) and spectral-domain OCT (SD-OCT), and to evaluate two methods defining the optic nerve head (ONH) centring: Centred Each Time (CET) vs Centred Once (CO), in terms of RNFL thickness measurement variability on SD-OCT.

METHODS

Twenty-seven eyes (14 healthy subjects) had three circumpapillary scans with TD-OCT and three raster scans (three-dimensional or 3D image data) around ONH with SD-OCT. SD-OCT images were analysed in two ways: (1) CET: ONH centre was defined on each image separately and (2) CO: ONH centre was defined on one image and exported to other images after scan registration. After defining the ONH centre, a 3.4 mm diameter virtual circular OCT was resampled on SD-OCT images to mimic the conventional circumpapillary RNFL thickness measurements taken with TD-OCT.

RESULTS

CET and CO showed statistically significantly better reproducibility than TD-OCT except for 11:00 with CET. CET and CO methods showed similar reproducibility.

CONCLUSIONS

SD-OCT 3D cube data generally showed better RNFL measurement reproducibility than TD-OCT. The choice of ONH centring methods did not affect RNFL measurement reproducibility.

Endoscopic decompression using a transanal drainage tube for acute obstruction of the rectum and left colon as a bridge to curative surgery

OBJECTIVE

The aim of this study was to clarify the usefulness of the management of acute left colon and rectum obstruction because of colorectal carcinoma using a transanal ileus drainage tube before curative surgery.

METHOD

Forty-six patients (24 males and 22 females, aged 24-94 years, mean = 56.2) treated between September 2005 and March 2007 for acute left colon and rectal obstruction were identified in a colorectal obstruction database, and their clinical and radiological features were reviewed. After a cleaning enema was administered, urgent colonoscopy was performed. Subsequently, endoscopic decompression using a ileus tube was attempted.

RESULTS

Endoscopic decompression using the ileus tube was technically successful in 45 of 46 patients (97.8%). Perforation occurred in one patient 3 days later and emergent operation was performed. The site of obstruction was the rectum in 15 patients, the sigmoid colon in 18, the descending colon in 13. Following adequate cleansing of the colon, patients' abdominal girth were decreased from 91 +/- 4 cm before drainage to 82 +/- 2 cm 7 days later, and one-stage surgery after 8 +/- 1 days (SD; range 7-10 days) were performed. No anastomotic leakage or postoperative stenosis occurred after operation.

CONCLUSION

Management of acute left colon and rectum obstruction because of colorectal carcinoma using the ileus tube was found to be effective and safe, considered as a bridged method before curative surgery.

Endogenous activated protein C signaling is critical to protection of mice from lipopolysaccaride-induced septic shock

SUMMARY BACKGROUND

Activated protein C (APC) is known to protect animals from sepsis. Endogenous protein C is important in protection. It is unknown whether the cytoprotective or anticoagulant properties of protein C (PC) are responsible for the protective effect of endogenous PC.

OBJECTIVE

To determine if signaling by endogenous activated protein C contributes to survival in sepsis.

METHODS

We used an immunochemical approach to either block all of the known activities of protein C using mAb MPC1609 or, alternatively, selectively block the anticoagulant activity of activated protein C while sparing some of its cytoprotective activities using mAb MAPC1591.

RESULTS

MPC1609 blocked APC binding to endothelium whereas MAPC1591 enhanced binding. MPC1609 prevented APC protection of endothelial barrier function whereas MAPC1591 did not. Injection of MPC1609, but not MAPC1591, with a sublethal dose of lipopolysaccharide (LPS) caused lethality. At 18 h, the mice injected with MPC1609 plus LPS had much higher interleukin-6 (IL-6) levels than mice injected with LPS alone or LPS plus MPC1591. In these mice treated with LPS plus MPC1609, higher blood urea nitrogen (BUN) and creatinine levels suggested that an acute renal failure might contribute to a slow clearance of IL-6.

CONCLUSIONS

These studies demonstrate for the first time that cytoprotective activities of APC, and not the anticoagulant activity, is required for protection in this sepsis model. Similar anti-human antibodies may prove useful in clinical conditions such as trauma and hemophilia where cytoprotection is desirable, but the anticoagulant activity of endogenous activated protein C may contribute to bleeding.

[Cloning and sequencing of the genes coding for the histidine-rich protein II of Plasmodium falciparum]

AIM

To compare and analyze the homology of genes encoding histidine-rich proteinII (HRPII) of different Plasmodium falciparum isolates.

METHODS

Using PCR technique, the complete genes coding for HRPII of P. falciparum isolates FCC1/HN and VN isolates were amplified. PCR products were digested by HindIII/BamHI and cloned into plasmid pUC19. The recombinant plasmid HRPII/pUC19 was screened and identified by PCR and restriction analysis. The cloned HRPII genes were sequenced by Sanger's method.

RESULTS

HRPII genes of FCC1/HN and VN isolates were successfully amplified and cloned into pUC19. DNA sequencing showed that the coding length of HRPII gene was 1,020 bp without introns in FCC1/HN and VN isolates, however, there were ten points mutations between them. FCC1/HN isolate exhibited 98.8%, 92.2% and 98.7% homology in amino acids with isolates VN, IMTM22, and Itg2, respectively. Though the numbers of repeat sequences were different in four isolates, they had the same hydrophobic leader sequence and a single putative glycosylation site. The secondary structure analysis showed that the main antigenic determinants of four isolates were located on 5' end non-repeat region (amino acids 1-60).

CONCLUSION

FCC1/HN isolate was highly homologous in the coding region of HRPII with VN, IMTM22, and Itg2 isolate. Four isolates exhibited similar structural characteristics and antigenic determinants in HRPII.

Mitogenic effect contributes to increased virulence of Streptococcus suis sequence type 7 to cause streptococcal toxic shock-like syndrome

Streptococcus suis serotype 2 sequence type 7 strains emerged in 1996 and caused a streptococcal toxic shock-like syndrome in 1998 and 2005 in China. Evidence indicated that the virulence of S. suis sequence type 7 had increased, but the mechanism was unknown. The sequence type 7 strain SC84, isolated from a patient with streptococcal toxic shock-like syndrome during the Sichuan outbreak, and the sequence type 1 strain 31533, a typical highly pathogenic strain isolated from a diseased pig, were used in comparative studies. In this study we show the mechanisms underlying cytokine production differed between the two types of strains. The S. suis sequence type 7 strain SC84 possesses a stronger capacity to stimulate T cells, naive T cells and peripheral blood mononuclear cell proliferation than does S. suis sequence type 1 strain 31533. The T cell response to both strains was dependent upon the presence of antigen-presenting cells. Histo-incompatible antigen-presenting cells were sufficient to provide the accessory signals to naive T cell stimulated by the two strains, indicating that both sequence type 7 and 1 strains possess mitogens; however, the mitogenic effect was different. Therefore, we propose that the difference in the mitogenic effect of sequence type 7 strain SC84 compared with the sequence type 1 strain 31533 of S. suis may be associated with the clinical, epidemiological and microbiological difference, where the ST 7 strains have a larger mitogenic effect.

Signal transduction in electrically stimulated articular chondrocytes involves translocation of extracellular calcium through voltage-gated channels

OBJECTIVE

To ascertain, using specific inhibitors, the potential role of calcium-related signal transduction pathways in the mechanism of cartilage matrix protein gene induction and metalloproteinase gene suppression by capacitively coupled electric fields.

METHODS

Articular chondrocytes were isolated from adult bovine patellae and cultured in high density for 7 days. To study matrix protein expression, cells cultured in the absence or presence of specific calcium pathway inhibitors were exposed to a capacitively coupled electrical field (60 kHz, 20 mV/cm): for aggrecan 1h at 50% duty cycle and for type II collagen 6h at 8.3% duty cycle. To study metalloproteinase expression in the presence of interleukin 1 beta (IL-1beta), cells were cultured as above but exposed for only 30 min to a 100% duty cycle signal. At harvest, total mRNA was isolated and aggrecan, type II collagen, matrix metalloproteinase (MMP-1, -3 and -13) and aggrecanase [a disintegrin and metalloproteinase with thrombospondin repeats (ADAMTS-4 and -5)] mRNA expression were measured by quantitative real-time polymerase chain reaction (qPCR).

RESULTS

(1) In the absence of inhibitors, appropriate electrical stimulation induces a 3-4-fold up-regulation of both aggrecan and type II collagen mRNA and a 3.7-9.6-fold down-regulation of IL-1beta-induced metalloproteinases; (2) the presence of inhibitors alone does not affect any target mRNA levels; (3) inhibitors of intracellular calcium regulation and inositol 1,4,5-triphosphate (IP(3)) formation [8-(diethylamino)octyl-3,4,5,-trimethoxybenzoate hydrochloride (TMB-8) and neomycin, respectively] have no effect on regulation of target mRNA levels by electrical stimulation; and (4) inhibitors of voltage-gated calcium channels (verapamil), calmodulin activation (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride, W-7), calcineurin activity (cyclosporin A), phospholipase C activity (bromophenacyl bromide, BPB) and prostaglandin E(2) (PGE(2)) synthesis (indomethacin) completely inhibit the effects of electrical stimulation.

CONCLUSIONS

The results are consistent with the effects of electrical stimulation involving a pathway of extracellular Ca(2+) influx via voltage-gated calcium channels rather than from intracellular Ca(2+) repositories; and with downstream roles for calmodulin, calcineurin and nuclear factor of activated T-cells (NF-AT) rather than for phospholipase C and IP(3).

Trichosanthin, an extract of Trichosanthes kirilowii, effectively prevents acute rejection of major histocompatibility complex-mismatched mouse skin allograft

Trichosanthin is an active component extracted from the root tuber of the Chinese medicinal herb Trichosanthes kirilowii. Trichosanthin has abortifacient, anti-tumor, anti-HIV, and immunoregulatory functions. In the current study, we explored its potential effect on allograft rejection in a murine skin transplantation model across a fully mismatched major histocompatibility complex. It was found that treatment of recipient mice with trichosanthin (0.25 or 1 mg/kg, IP) significantly delayed allograft rejection. T cells that originated from recipients treated with trichosanthin were restimulated with donor-specific splenocytes showed a significantly reduced response compared with that of control recipients. In line with these results, the mRNA levels for interleukin (IL)-2 and interferon-gamma were decreased and the levels of IL-4 and IL-10 were increased in splenic T cells originating from trichosanthin-treated recipients. These results indicated that trichosanthin may have potential therapeutic value for transplantation rejection and other inflammatory diseases.

Heat-stress-induced damage to porcine small intestinal epithelium associated with downregulation of epithelial growth factor signaling

Extreme heat during certain days of the summer renders pigs susceptible to severe heat stress, which negatively affects their growth performance. We hypothesized that such heat stress impaired the small intestinal mucosa, a site responsible for nutrient absorption. To simulate heat stress, Chinese experimental mini-pigs were treated with 5 h of continual 40 degrees C temperature each day for 10 d in succession. Pigs were killed at 1, 3, 6 and 10 d after treatment, and small intestinal epithelia were sampled for histochemical examination and biochemical analyses. The duodenum and jejunum were seriously damaged within 3 d of initiation of treatment. Subsequent study of the process of jejunum recovery showed that the initiation of recovery started within 6 d following heat stress. Such damage was associated with the downregulation of epithelial growth factor signaling. In conclusion, heat stress induced short-term damage to the epithelium of porcine intestine. Because the intestinal epithelium is crucial for nutrient uptake, such damage should partially account for the impairment of growth performance of pigs under heat stress.

Fabrication of oriented ZnO nanorod arrays and their optical performances

The well-aligned ZnO nanorod arrays were fabricated through a simple chemical process under low temperature. The nanorod arrays were characterized by XRD, SEM, TEM, HRTEM and SAED, and their optical performances were investigated with Raman and PL spectroscopy. The results show that the as-prepared ZnO nanorod arrays are dense, the individual ZnO nanorod is hexagonal shape and grows along c-axis perpendicular to the substrate surface with good single crystal in nature. The Raman property of nanorod arrays displays change with the altering the preparation conditions. Moreover, the PL performances of ZnO nanorod arrays exhibit tunable character with adjusting the synthesis conditions.

Ethnic variation in the correlation between random serum glucose concentration and glycated haemoglobin

AIMS

To determine if the relationship between serum glucose concentration and glycated haemoglobin is different between African-Americans and whites.

METHODS

Retrospective cross-sectional study comparing the association between glycated haemoglobin and serum glucose levels, based upon ethnicity. Two databases were evaluated: (i) 4215 African-American and 6359 white outpatients who had simultaneous glycated haemoglobin, random serum glucose and creatinine concentration measurements between 2000 and 2007 at the North Carolina Baptist Hospital and (ii) 1021 white and 312 African-American Diabetes Heart Study (DHS) participants.

RESULTS

In North Carolina Baptist Hospital clinic attendees, a given glycated haemoglobin was associated with higher serum glucose concentrations in African-Americans compared with whites. In a multivariate model with glycated haemoglobin as the outcome variable, racial differences remained significant after adjustment for serum glucose, age, gender and kidney function. For individuals with a serum glucose between 5.6 and 8.3 mmol/l, the glucose : glycated haemoglobin ratio was 1.03 +/- 0.16 mmol/l/% in white individuals and 0.99 +/- 0.17 mmol/l/% in African-Americans (P < 0.0001). For a glycated haemoglobin value of 7.0%, there was a 0.98-mmol/l difference in predicted serum glucose concentration in 50-year-old African-American men, relative to white. Results were replicated in the DHS, where in a best-fit linear model, after adjustment for glucose, African-American race was a significant predictor of glycated haemoglobin (P < 0.0001).

CONCLUSIONS

African-Americans have higher glycated haemoglobin values at given serum glucose concentrations relative to whites. This finding may contribute to the observed difference in glycated haemoglobin values reported between these race groups.