Microcrystalline Silicon in a-SI:H Based Multljunction Solar Cells

Materials issues central to the application of microcrystalline silicon (μc-Si) doped layers in a-Si:H based solar cells are discussed, which include: (1) characterization of ultra-thin layers to be incorporated in the device, and (2) methods to promote nucleation of μc-Si on desired substrates within a thickness on the order of ∼100Å. Successful application of (μc-Si) in multijunction a-Si:H based solar cells are demonstrated.

Expression and prognostic role of pan-Ras, Raf-1, pMEK1 and pERK1/2 in patients with hepatocellular carcinoma

AIMS

Ras/Raf/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling cascades play important roles in the transmission of signals involved in apoptosis. Importantly, components of these pathways are aberrantly expressed in human cancer. However, there is limited data linking clinical outcomes with the aberrant expression of this pathway. The present study analyzed the prognostic values of pan-Ras, Raf-1, phosphorylated MEK1 (pMEK1) and phosphorylated ERK1/2 (pERK1/2) in hepatocellular carcinoma (HCC).

METHODS

Expression of pan-Ras, Raf-1, pMEK1 and pERK1/2 in 81 HCC patients who underwent curative resection was examined by immunohistochemical staining. Long-term survival after resection of patients according to the expression of pan-Ras, Raf-1, pMEK1 and pERK1/2 was assessed using univariate analysis and multiple Cox proportional hazards model.

RESULTS

In univariate analysis, patients with Raf-1 or pMEK1 overexpression had shorter disease-free survival (DFS) (P<0.05) and poorer overall survival (OS) (P<0.05) than groups with weak-expression of Raf-1 or pMEK1, respectively. Patients with pan-Ras overexpression had poorer overall survival (OS) (P<0.05) than the group with weak-expression of pan-Ras. Importantly, Raf-1 overexpression was a promising prognostic marker for poor survival according to multivariate Cox regression analysis (DFS, Hazard Ratio 1.807, P = 0.035; OS, Hazard Ratio 1.959, P = 0.044).

CONCLUSIONS

Raf-1 overexpression could be considered as an independent prognostic biomarker in HCC and may predict early tumor recurrence and death for HCC patients. It can be used to stratify patients at higher risk for poor prognosis and help to select the appropriate therapeutic regime of HCC.

Local delivery of recombinant human bone morphogenetic protein-2 increases axonal regeneration and the expression of tau protein after facial nerve injury

This study explored the function and possible mechanism of bone morphogenetic protein-2 (BMP-2) in the healing of injured peripheral nerves in vivo. Rabbit facial nerves were injured by clamping and then treated with recombinant human BMP-2 (rhBMP-2) or phosphate-buffered saline (control) by injecting once during surgery and twice a day post-injury for 7 days. Facial nerve fragments within 5 mm of the clamping point were examined at different times post-surgery. Axon structures visualized by Bielschowsky staining were similar in experimental and control nerves 2 and 6 weeks post-injury. At 4 weeks post-injury, cross-section images of facial nerves showed that axons treated with rhBMP-2 were denser and thicker, and levels of tau protein were increased. It is concluded from these data that rhBMP-2 may affect injured facial nerve regeneration by inducing more neurons to return to embryonic patterns of tau gene expression.

Spectroscopic Characterization of Ion-Implanted GaN

We investigate implantation of high purity HVPE GaN with Mg, Be, C, Zn, Cd, Ca, N, O, P, As, Ne, and Ar. After annealing at 1300 °C, the material is characterized using low temperature photoluminescence (PL). The Mg acceptors exhibit much better optical activation than Be, C, Zn, Cd, or Ca acceptors implanted and annealed under the same conditions. Acceptor-bound exciton peaks and well-resolved donor-acceptor pair bands are observed for both Mg and Zn. A broad peak centered near 2.78 eV is obtained for Cd, confirming that it is deeper than Zn. Isoelectronic As or P exhibit sharp no-phonon bound exciton lines at 2.952 and 3.200 eV, respectively. Defect-related bands centered at 2.2 and 2.35 eV are studied. Both Be and C strongly enhance the yellow (2.2 eV) PL band, but no other impurities do so, including O.

Technological Development for Commercialization of Amorphous Silicon Based Multijunction Modules

Some of the significant steps in technological development for large-scale commercialization of amorphous silicon (a-Si:H) based multijunction photovoltaic modules are presented. These developments are establishing a high quality baseline process for manufacturing large-area ( ˜ 8 ft2) a-Si:H/a-SiGe:H tandem junction modules with improved stabilized conversion efficiency, throughput, yield, and reduced materials usage.

DMP1 processing is essential to dentin and jaw formation

Dentin matrix protein 1 (DMP1), an acidic protein that is essential to the mineralization of bone and dentin, exists as proteolytically processed fragments in the mineralized tissues. In this study, we characterized the tooth and jaw phenotypes in transgenic mice containing no wild-type DMP1, but expressing a mutant DMP1 in which Asp(213), a residue at one cleavage site, was replaced by Ala(213) (named "Dmp1-KO/D213A-Tg" mice). The teeth and mandible of Dmp1-KO/D213A-Tg mice were compared with those of wild-type, Dmp1-knockout (Dmp1-KO), and Dmp1-KO mice expressing the normal Dmp1 transgene. The results showed that D213A-DMP1 was not cleaved in dentin, and the expression of D213A-DMP1 failed to rescue the defects in the dentin, cementum, and alveolar bones in the Dmp1-KO mice. These findings indicate that the proteolytic processing of DMP1 is essential to the formation and mineralization of dentin, cementum, and jaw bones.

Effect of inhibition of heat-shock protein 90 on mutant c-Kit protein as modulated by mRNA expression and protein degradation through both proteasome and autophagy-mediated pathways

54

Background: c-Kit is a known client protein of heat-shock protein 90 (Hsp90). Inhibition of Hsp90 can reduce the expression of c-Kit protein in human mastocytoma and gastrointestinal stromal tumor (GIST) cells, which is conceived through the proteasome degradation pathway.

Methods: COS-1 cells transfected with vectors containing CMV promoter-driven various c-Kit mutants (imatinib- sensitive or imatinib-resistant) and human GIST882 cells (with endogenous exon 13 mutant c-Kit) were used to investigate the efficacy NVP-AUY922, a new class of Hsp90 inhibitor, on suppressing the constitutive activation of mutated c-Kit. Detail mechanisms of protein regulation, as RNA transcription, RNA stability, and protein degradation were studied.

Results: NVP-AUY922 is more potent than 17-AAG to inhibit the proliferation of imatinib-sensitive GIST882 cells. Further study showed that NVP-AUY922 down-regulated both total and phosphorylated c-Kit proteins in dose- and time-dependent manners in both GIST882 cells and mutant c-Kit (including imatinib-resistant exon11/17 double mutants) expressed in COS-1 cells. Surprisingly, the NVP-AUY922-induced c-Kit degradation in both cell models could be reversed by proteasome-degradation inhibitor and autophagy inhibitor. The involvement of autophagy in NVP-AUY922-induced c-Kit protein degradation was further confirmed by co-localization of c-Kit and autophagosome by immuno-staining. In addition, NVP-AUY922 treatment resulted in a reduction of c-Kit mRNA level in GIST882 cells but not c-Kit expressing COS-1 cells, which could be explained by the use of CMV promoter in artificial COS-1 cell model.

Conclusions: Taken together, these findings provide the first evidence that down-regulation of mutant c-Kit protein by Hsp90 inhibitor involved both transcription and post-translation levels. Of the latter, autophagy- as well as proteasome-mediated degradation pathways were involved. These observations highlight the use of NVP-AUY922 either alone or in combination with autophagy modulators in imatinib-refractory, c-Kit-expressing GIST. Supported by 99D1-TC-CADOH03.

[Table: see text]

A multinational phase II study of liposome irinotecan (PEP02) for patients with gemcitabine-refractory metastatic pancreatic cancer

237

Background: PEP02 is a novel nanoparticle liposome formulation of irinotecan (CPT-11) that has improved pharmacokinetics and tumor biodistribution of both CPT-11 and its active metabolite-SN38 compared to the free form drug. PEP02 has showed encouraging safety and efficacy in various tumor types, including significant antitumor activity in a human pancreatic cancer L3.6pl orthotopic nude mouse xenograft model. In previous phase I studies, PEP02 either alone or in combination with 5-FU/LV demonstrated prolonged disease control in 5 of 7 (71%) patients (pts) with gemcitabine (GEM)-refractory advanced pancreatic cancer (PC). This phase II study aims to evaluate PEP02 monotherapy as 2nd-line treatment in pts with metastatic, GEM-refractory PC.

Methods: Pts were eligible if they had metastatic pancreatic adenocarcinoma, KPS ≥ 70, and progressed following one line of GEM-based therapy. Treatment consisted of PEP02 120 mg/m2 administered as a 90-minute infusion every 3 weeks. A Simon's 2-stage design was used with 16 pts in the first stage and 39 pts in total; primary objective was 3-month survival rate (OS3-month).

Results: Between March 2009 and August 2010, 37 pts were enrolled at 3 centers in the U.S. and Taiwan. Characteristics for the first 31 evaluable pts: 13 M/18 F; age 39-82 yrs; 19 Asian/12 Caucasian, KPS 100/90/80/70: 5/14/4/8. Mean number of treatment cycles is 5 (range, 1-22). Disease control rate (minor response + stable disease >2 cycles) is 52%. 8 of 24 pts (33%) with elevated baseline CA19-9 have had >50% biomarker decline. To date, 23/31 pts (74%) have survived > 3 months, with 4 pts still alive after 1 year. Reasons for study discontinuation: 74% progressive disease, 9% drug-related toxicity, 17% other. Preliminary safety data is available for the first stage. Most common G3/4 adverse events included: fatigue (31%), neutropenia (25%), nausea/vomiting (19%), and diarrhea (13%).

Conclusions: This study has already met its primary endpoint (predicted OS3-month >65%). PEP02 appears to have both activity and tolerable side effects for pts with metastatic, GEM-refractory PC, and represents a promising option for this pt population with few standard options.

[Table: see text]

Randomized phase II study of PEP02, irinotecan, or docetaxel as a second-line therapy in gastric or gastroesophageal junction adenocarcinoma

6

Background: PEP02 is a novel nanoparticle liposome formulation of irinotecan (CPT-11). In phase I studies, PEP02 has improved pharmacokinetics (PK) of CPT-11 and its active metabolite-SN38 with encouraging safety and tumor response in several cancer types including gastric cancer. This study evaluated the efficacy and safety of PEP02 (P), irinotecan (I) or docetaxel (D) as a single agent in gastric or gastroesophageal junction (GEJ) adenocarcinoma.

Methods: A randomized, 3 arms (1:1:1), Simon's 2-stage (2/21, 5/41 based on tumor response) study was conducted in Europe and Asia. Patients (pts) with locally advanced or metastatic disease, failed to one prior chemotherapy, ECOG PS ≤ 2, at least 1 measurable lesion, no prior CPT-11 or taxane, were treated with P - 120 mg/m2, I - 300 mg/m2, or D - 75 mg/m2 every 3 weeks. PK and pharmacogenetics (PGx) samples were collected for pts in P and I arms.

Results: A total of 135 pts were randomized with 132 (44 per arm) treated between Jan 2008 and Jun 2010. Pts demographics (P/I/D): median age: 56/62/58, male (%): 79.5/77.3/77.3, Pts from Europe (%): 54.6/52.3/56.8, metastatic (%): 97.7/90.9/97.7, gastric adenocarcinoma (%): 84.1/79.6/68.2, and ECOG 0 + 1 (%): 93.2/93.2/90.9. The confirmed responders of P/I/D were 6 (13.6%)/3 (6.8%)/7 (15.9%) and disease control were 27 (61.4%)/27 (61.4%)/24 (54.6%). These three arms have similar progression free survival and overall survival. If stratified by region, Asian pts had longer survival than European pts. Toxicities of P/I/D were: grade 3/4 neutropenia (%): 9.1/13.6/15.9. grade 3/4 diarrhea (%): 27.3/18.2/2.3, hand-foot syndromes (%): 0.0/6.8/18.2. It was notable that symptoms related to acute cholinergic syndrome were less reported in P arm than in I arm. The PK data showed the mean T1/2, Cmax and AUC0→∞ of SN-38 in P/I arms were 88.8/22.8 hr, 8.79/44.1 ng/mL and 879/440 hr x ng/mL.

Conclusions: This randomized phase II study suggests that PEP02 improves the PK profile and tumor response over irinotecan, and it is as efficacious as docetaxel in the 2nd-line treatment for gastric or GEJ adenocarcinoma. PEP02 is worthy of further evaluation as either 1st- or 2nd-line setting in future gastric cancer studies.

[Table: see text]

Pooled safety results from SPIRITT: A multicenter, open-label, randomized, phase II study of FOLFIRI with panitumumab (pmab) or bevacizumab (bev) as second-line treatment (tx) in patients (pts) with metastatic colorectal cancer (mCRC)

477

Background: Pmab is a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR) approved as monotherapy in pts with chemorefractory mCRC. Many pts with mCRC who have progressed on a bev-containing regimen receive second-line bev + chemotherapy despite the lack of prospective, randomized data supporting this approach. A phase III study recently showed that pmab + second-line FOLFIRI improved progression-free survival (PFS) in pts with wild-type (WT) KRAS tumors vs chemotherapy alone. This study was amended after enrollment began to focus hypothesis testing on the WT KRAS population and is evaluating the safety and efficacy of pmab + FOLFIRI vs bev + FOLFIRI in pts who received first-line therapy with an oxaliplatin-based regimen + bev.

Methods: This is a randomized, phase II, open-label study in pts with mCRC with disease progression or intolerability after ≥ 4 doses of first-line oxaliplatin-based chemotherapy + bev. Pts are randomized 1:1 to receive either 6 mg/kg pmab Q2W + FOLFIRI or bev (given at institutional standard dose Q2W) + FOLFIRI. Tx is administered until disease progression (PD), death, or withdrawal from study. The primary endpoint is PFS in patients with WT KRAS tumors. Other endpoints include objective response rate, overall survival, safety, and patient-reported outcomes.

Results: At the time of data cutoff, 216 of 277 planned pts were enrolled. 175 (81%) pts discontinued study tx and 39 (18%) pts remain on tx. Any grade adverse events (AEs) were reported in 197 (92%) pts. 38 (18%) pts had AEs that led to withdrawal from tx or study. Serious AEs were reported in 66 (31%) pts and included gastrointestinal disorders (13%), infections and infestations (8%), respiratory disorders (7%), and metabolism and nutrition disorders (7%). Fatal AEs were reported in 18 (8%) pts of which 9 (4%) were related to disease progression.

Conclusions: The aggregate safety profile is consistent with expected toxicities of FOLFIRI in combination with an anti-EGFR or an anti-VEGF targeted therapy in second-line mCRC. Detailed pooled safety results will be presented at the meeting.

[Table: see text]

A randomized, phase I/II trial of AMG 102 or AMG 479 in combination with panitumumab (pmab) compared with pmab alone in patients (pts) with wild-type (WT) KRAS metastatic colorectal cancer (mCRC): Safety and efficacy results

366

Background: Pmab is a fully human anti-epidermal growth factor receptor monoclonal antibody (mAb) approved as monotherapy for pts with mCRC. AMG 102 and AMG 479 are investigational, fully human mAbs against hepatocyte growth factor (HGF) and insulin-like growth factor receptor 1 (IGF1R), respectively. This 3-part study evaluated the safety and efficacy of AMG 102 or AMG 479 in combination with pmab.

Methods: Part 1 was a phase 1b, open-label, dose-finding study to determine a tolerable dose of AMG 102 in combination with pmab. Part 2 was a phase II, randomized, blinded, placebo-controlled trial that explored pmab + the dose of AMG 102 selected in Part 1 vs pmab + AMG 479 vs pmab + placebo. Part 3 is a 2-arm randomized extension study for pts who developed disease progression (PD) or intolerability to pmab + placebo in part 2. Eligible pts were ≥ 18 years old with WT KRAS mCRC and ECOG PS 0/1. In part 1, all pts received 6 mg/kg pmab + 10 mg/kg AMG 102 Q2W IV until PD or intolerability. The primary endpoint of part 1 was the incidence of dose-limiting toxicities (DLTs). The primary endpoint for part 2 is objective response rate (ORR).

Results: In part 1, no DLTs were reported for the first 6 DLT-evaluable pts. A total of 11 pts were enrolled in part 1 prior to the decision to use the 10 mg/kg Q2W AMG 102 dose in part 2; 5 pts were men; mean (range) age was 56 (37-75) yrs; ECOG 0/1 was 55%/45%. Grade 3 treatment-related adverse events (AEs) were acneiform dermatitis or rash (55%), paronychia (18%), infection (9%), capillary leak syndrome (9%), erythema (9%), nail disorder (9%), and pruritus (9%). There were no grade 4 or 5 treatment-related AEs. Serious AEs included acneiform dermatitis (n = 1), intestinal obstruction (n = 1), cerebrovascular accident (n = 1), capillary leak syndrome (n = 1), and anemia/general health deterioration (n = 1). One pt died on study from PD. In part 2, 142 pts received at least one dose of study drug; enrollment is complete, and data analyses are ongoing.

Conclusions: In part 1, 6 mg/kg pmab + 10 mg/kg AMG 102 Q2W was well tolerated. Primary efficacy results from part 2, including ORR and progression-free survival, will be presented.

[Table: see text]

Phase II study of weekly low-dose everolimus plus weekly 24-hour infusions of cisplatin and high-dose 5-fluorouracil and leucovorin for first-line treatment in patients with advanced gastric cancers

86

Background: Cisplatin-HDFL, consisting of weekly 24-hour infusions of cisplatin and high-dose 5-fluorouracil (5-FU) and leucovorin (LV), is an effective and low-toxicity regimen for patients with advanced gastric cancer (GC) in Taiwan (J Clin Oncol. 1994;12(4):875; J Clin Oncol. 2006;24(18S):A14063). Everolimus (RAD001), a derivative of rapamycin, is an orally bioavailable mTOR inhibitor. We have demonstrated that low-dose everolimus (0.5-5.0 nM) sensitizes cytotoxic effects of cisplatin and 5-FU in GC cells (Proc Am Assoc Cancer Res. 2007;48:A4043).

Methods: Patients who had pathologically confirmed chemonaive advanced GC, at least 1 measurable lesion, a fasting serum triglyceride level > 70 mg/dl, ECOG PS 0-2, and adequate organ functions were treated with everolimus 10 mg po on days 1, 8, and 15 concurrently with the initiation of chemotherapy; cisplatin 35 mg/m2 iv 24h infusion on days 1 and 8; 5-FU 2,000 mg/m2 and LV 300 mg/m2 (HDFL) iv 24h infusion on days 1, 8, and 15, in a every 28-day cycle. Response assessment was performed every 2 cycles. The primary endpoint was confirmed objective response rate (RR) by RECIST.

Results: Between March 2008 and July 2010, 24 patients (M:11, F:13) with a median age of 53 (range: 33-69) were evaluable for response. The overall RR was 50% (95% CI: 29-71%) with 12 partial responders. Among a total of 162 cycles (median: 7, range: 1-13) given, grade (Gr) 3/4 toxicities included neutropenia (4.3%), infection (2.5%), nausea (3.1%) and vomiting (3.1%). Gr 1/2 nausea, vomiting, stomatitis, and diarrhea developed in 19.2%, 15.4%, 14.8%, and 5.5% of cycles, respectively. Skin rash and hand-foot syndrome were mild. One patient developed reversible HDFL-related hyperammonemic encephalopathy. Median progression-free survival was 8.4 months (range: 1.3-15.4+) and median overall survival was 14.8 months (range: 4.0-21.6+).

Conclusions: Weekly low-dose everolimus plus weekly cisplatin-HDFL is an effective first-line regimen for patients with advanced GC. Addition of weekly low-dose everolimus to infusional cisplatin-HDFL did not add gastrointestinal toxicities.

No significant financial relationships to disclose.

Phase II trial of S-1 combined with oxaliplatin (SOX) as neoadjuvant chemotherapy for locally advanced gastric cancer

122

Background: Previous phase II trial with combination therapy of S-1 plus oxaliplatin (SOX) demonstrated high response rate and well tolerability in patients with untreated advanced gastric cancer. The aim of this phase II trial was to evaluate the efficacy and safety of SOX as neoadjuvant chemotherapy for locally advanced gastric cancer (AGC).

Methods: Eligibility criteria included a histologically proven AGC with stage IIIb, IIIc (AJCC 7th edition), at least 1 measurable lesion, no prior chemotherapy, ECOG 0∼2, adequate hepatic, renal, and bone marrow function. Enrolled patients were staged by EUS and CT. The neoadjuvant chemotherapy consisted of 3-4 cycles of oxaliplatin (130 mg/m2) on day 1 and S-1 (80 mg/m2/day) for 14 days with 7 days rest. After chemotherapy, the patients underwent surgery.

Results: From Dec 2009 to Sep 2010, 35 patients (IIIb; 19pts, IIIc; 16pts) were enrolled. The median age of the patients was 54.6 years (range; 20-72 y). All patients were available for evaluating the clinical responese and adverse events. The overall response rate was 68.5% (1CR, 23 PR, 9 SD, 2 PD). 32 patients underwent surgical resection. Of them, 27 patients underwent standard D2 surgery and 5 patients had palliative surgery. 25 patients had R0 resection. Postoperative pathological examination showed that most of the surgical patients were in T4a stage. According to Lauren classification, 71.9% patiens (23/32pts) were diffuse type, SOX showed higher respons rate (1CR, 20 PR, 2 SD, RR: 91.3%) among these patients. Major grade 3/4 hematological toxicities were anemia (5.7%), neutropenia (5.7%) and liver dysfunction (8.6%) and non-hematological toxicities were anorexia (5.7%) and vomiting (11.4%). But most of the adverse events were managable.

Conclusions: Neoadjuvant chemotherapy with S-1 plus oxaliplatin (SOX) showed high response rate and and R0 resection rate for locally advanced GC, especially for diffuse type patients. All the patients did not have severe toxicity during the process of chemotherapy. This is the preliminary results, and the survival benefit in locally advanced GC patients that respond to SOX neoadjuvant chemotherapy needs to be addressed by a randomized-controlled trial.

No significant financial relationships to disclose.

Excitation and dissociation of tungsten hexacarbonyl W(CO)6: statistical and nonstatistical dissociation processes

We have studied the excitation and dissociation processes of the molecule W(CO)(6) in collisions with low kinetic energy (3 keV) protons, monocharged fluorine, and chlorine ions using double charge transfer spectroscopy. By analyzing the kinetic energy loss of the projectile anions, we measured the excitation energy distribution of the produced transient dications W(CO)(6)(2+). By coincidence measurements between the anions and the stable or fragments of W(CO)(6)(2+), we determined the energy distribution for each dissociation channel. Based on the experimental data, the emission of the first CO was tentatively attributed to a nonstatistical direct dissociation process and the emission of the second or more CO ligands was attributed to the statistical dissociation processes. The dissociation energies for the successive breaking of the W-CO bond were estimated using a cascade model. The ratio between charge separation and evaporation (by the loss of CO(+) and CO, respectively) channels was estimated to be 6% in the case of Cl(+) impact.

hSSB1 binds and protects p21 from ubiquitin-mediated degradation and positively correlates with p21 in human hepatocellular carcinomas

Downregulation of hSSB1, a single-stranded DNA-binding protein, causes increased radiosensitivity, defective checkpoint activation and genomic instability. However, the mechanisms of hSSB1 function in these responses remain to be uncovered. Here, we present evidence that hSSB1 directly binds p21 and this interaction may prevent p21 from ubiquitin-mediated degradation. Furthermore, both promotion of the G1/S transition and abrogation of the G2/M checkpoints induced by hSSB1 knockdown are partially dependent on p21. Most importantly, hSSB1 and p21 levels are positively correlated in human hepatocellular carcinomas (HCC), as determined by immunostaining. Therefore, hSSB1 may positively modulate p21 to regulate cell cycle progression and DNA damage response, implicating hSSB1 as a novel, promising therapeutic target for cancers such as HCC.