Updated survival results of the randomized phase II study comparing cisplatin/capecitabine (CX) with epirubicin plus CX (ECX) in advanced gastric cancer (AGC)

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Background: We previously reported results of a randomized study showing that CX is equally active to ECX in terms of progression-free survival (PFS) (Yun et al. Eur J Cancer. 2010). Here we report updated overall survival (OS) results with an additional 12 months' follow-up.

Methods: Ninety-one chemotherapy-naïve patients with histologically-confirmed, measurable AGC were randomized to receive CX (cisplatin 75 mg/m2 iv on day 1 and capecitabine 1,000 mg/m2 bid po on days 1-14, n=45) or ECX (epirubicin 50 mg/m2 plus CX, n=44) every 3 weeks. After CX or ECX had failed, second-line chemotherapy (SLC) was recommended for all patients if their performance status was preserved.

Results: Treatment duration was similar for both arms (4.4 for CX v 4.2 months for ECX). There was no relevant difference in the occurrence of overall grade 3 or 4 toxicities between the CX and ECX arms (80% v 78%, respectively; p=0.516). However, none in the CX and 12% in the ECX arm discontinued treatment because of toxicity. There were no significant differences in therapeutic efficacy between CX and ECX with respect to the response rate (38% v 37%, respectively), PFS (6.4 v 6.5 months), as well as OS (12.7 v 13.8 months; p=0.51). After failure, 60% of patients (26 CX and 28 ECX patients) received SLC. However, OS was not differed whether a patient was treated with SLC or not (13.1 v 11.2 months; p=0.94).

Conclusions: The present analysis confirms previous findings that both CX and ECX appear to be comparatively active as first-line chemotherapy for AGC. Furthermore, the role of SLC in AGC warrants further evaluation.

No significant financial relationships to disclose.

Elevated LDH and paranasal sinus involvement are risk factors for central nervous system involvement in patients with peripheral T-cell lymphoma

Background: The incidence and risk factors of central nervous system (CNS) involvement in peripheral T-cell lymphomas (PTCLs) are still unclear.

Patients and methods: We analyzed 228 patients with PTCLs, excluding cases of extranodal natural killer/T-cell lymphoma and primary cutaneous T-cell lymphoma, by retrospectively collecting the clinical features and outcomes of the patients.

Results: Twenty events (8.77%, 20/228) of CNS involvement were observed during a median follow-up period of 13.9 months (range 0.03–159.43). Based on univariate analysis, elevated serum lactate dehydrogenase (LDH) level [P = 0.019, relative risk (RR) 5.904, 95% confidence interval (CI) 1.334–26.123] and involvement of the paranasal sinus (P = 0.032, RR 3.137, 95% CI 1.105–8.908) adversely affect CNS involvement. In multivariate analysis, both were independently poor prognostic factors for CNS relapse [elevated LDH level: P = 0.011, hazard ratio (HR) 6.716, 95% CI 1.548–29.131; involvement of the paranasal sinus: P = 0.008, HR 3.784, 95% CI 1.420–10.083]. The survival duration of patients with CNS involvement was significantly shorter than that of the patients without CNS involvement (P = 0.009), with median overall survival of 7.60 months (95% CI of 4.92–10.28) versus 27.43 months (95% CI of 0.00–57.38), respectively.

Conclusions: Elevated LDH level and involvement of the paranasal sinus are two risk factors for CNS involvement in patients with PTCLs. Considering the poor prognoses after CNS relapse, prophylaxis should be considered with the presence of any risk factor.

Warm water vapour in the sooty outflow from a luminous carbon star

The detection of circumstellar water vapour around the ageing carbon star IRC +10216 challenged the current understanding of chemistry in old stars, because water was predicted to be almost absent in carbon-rich stars. Several explanations for the water were postulated, including the vaporization of icy bodies (comets or dwarf planets) in orbit around the star, grain surface reactions, and photochemistry in the outer circumstellar envelope. With a single water line detected so far from this one carbon-rich evolved star, it is difficult to discriminate between the different mechanisms proposed. Here we report the detection of dozens of water vapour lines in the far-infrared and sub-millimetre spectrum of IRC +10216 using the Herschel satellite. This includes some high-excitation lines with energies corresponding to approximately 1,000 K, which can be explained only if water is present in the warm inner sooty region of the envelope. A plausible explanation for the warm water appears to be the penetration of ultraviolet photons deep into a clumpy circumstellar envelope. This mechanism also triggers the formation of other molecules, such as ammonia, whose observed abundances are much higher than hitherto predicted.

Pro-apoptotic activity of mBNIP-21 depends on its BNIP-2 and Cdc42GAP homology (BCH) domain and is enhanced by coxsackievirus B3 infection

Our previous study reported that mouse BNIP-21 (mBNIP-21) induces apoptosis through a mitochondria-dependent pathway. To map the functional domains of mBNIP-21, we performed mutational analyses and demonstrated that the BNIP-2 and Cdc42GAP homology (BCH) domain is required for apoptosis induction by mBNIP-21 targeting the mitochondria and inducing cytochrome c release. This pro-apoptotic activity was enhanced by coxsackievirus infection. However, deletion of the Bcl-2 homology 3 (BH3)-like domain, a well-known cell 'death domain' in proapoptotic Bcl-2 family proteins, did not affect the activity of mBNIP-21. These data were further supported by transfection of a mouse Bax (mBax) mutant, whose BH3 was replaced by the mBNIP-21 BH3-like domain. This replacement significantly reduced the pro-apoptotic activity of mBax. We also found that the predicted calcium binding domain has no contribution to the mBNIP-21-induced apoptosis. Further mapping of the motifs of BCH domain demonstrated that deletion of the hydrophobic motif proximal to the C-terminal of the BCH significantly reduced its proapoptotic activity. These findings suggest that mBNIP-21, as a member of the BNIP subgroup of the Bcl-2-related proteins, functions without need of BH3 but its BCH domain is critical for its activity in inducing cell elongation, membrane protrusions and apoptotic cell death.

Targeted delivery of anti-coxsackievirus siRNAs using ligand-conjugated packaging RNAs

Coxsackievirus B3 (CVB3) is a common pathogen of myocarditis. We previously synthesized a siRNA targeting the CVB3 protease 2A (siRNA/2A) gene and achieved reduction of CVB3 replication by 92% in vitro. However, like other drugs under development, CVB3 siRNA faces a major challenge of targeted delivery. In this study, we investigated a novel approach to deliver CVB3 siRNAs to a specific cell population (e.g. HeLa cells containing folate receptor) using receptor ligand (folate)-linked packaging RNA (pRNA) from bacterial phage phi29. pRNA monomers can spontaneously form dimers and multimers under optimal conditions by base-pairing between their stem loops. By covalently linking a fluorescence-tag to folate, we delivered the conjugate specifically to HeLa cells without the need of transfection. We further demonstrated that pRNA covalently conjugated to siRNA/2A achieved an equivalent antiviral effect to that of the siRNA/2A alone. Finally, the drug targeted delivery was further evaluated by using pRNA monomers or dimers, which carried both the siRNA/2A and folate ligand and demonstrated that both of them strongly inhibited CVB3 replication. These data indicate that pRNA as a siRNA carrier can specifically deliver the drug to target cells via its ligand and specific receptor interaction and inhibit virus replication effectively.

Phase I study of SIR-sphere plus sorafenib as first-line treatment in patients with nonresectable hepatocellular carcinoma: The Asia-Pacific Hepatocellular Carcinoma Trials Group protocol 05 (AHCC05)

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Background: Sorafenib has been shown to significantly prolong survival in patients with nonresectable hepatocellular carcinoma (HCC) without however significant tumour regression. The addition of radio-ablative therapy could confer additional survival benefit. This phase I trial was carried out to ascertain the toxicities and safety of this combination and was designed as a prelude to a phase II trial. Methods: Eligible patients were administered SIR-sphere (max dose 3 GBq) and subsequently given Sorafenib therapy (400mg bd) either 14 days (Cohort 1: first 3 patients) or 11 days (Cohort 2: subsequent patients) later. Assessment was carried out for 30 days after commencement of Sorafenib. Results: 10 patients were recruited into this phase I trial. The second patient became ineligible for sorafenib therapy after SIR-sphere due to pulmonary bleeding not related to radio-therapy and was excluded from assessment. The characteristics of the patients are in the Table. At the end of the study period, there was no adverse events (AE) of grade 3 or 4 for Cohort 1 and 3 for Cohort 2. The only serious adverse event (SAE) recorded was from Cohort 2. Conclusions: Starting sorafenib 14 days after SIR-sphere therapy is associated fewer AEs and SAEs. The phase II trial has commenced withsorafenib starting 14 days after SIR-sphere. [Table: see text]

[Table: see text]

The atypical protein kinase C in Aplysia can form a protein kinase M by cleavage

In vertebrates, a brain-specific transcript from the atypical protein kinase C (PKC) zeta gene encodes protein kinase M (PKM) zeta, a constitutively active kinase implicated in the maintenance of synaptic plasticity and memory. We have cloned the atypical PKC from Aplysia, PKC Apl III. We did not find a transcript in Aplysia encoding PKMzeta, and evolutionary analysis of atypical PKCs suggests formation of this transcript is restricted to vertebrates. Instead, over-expression of PKC Apl III in Aplysia sensory neurons leads to production of a PKM fragment of PKC Apl III. This cleavage was induced by calcium and blocked by calpain inhibitors. Moreover, nervous system enriched spliced forms of PKC Apl III show enhanced cleavage. PKC Apl III could also be activated through phosphorylation downstream of phosphoinositide 3-kinase. We suggest that PKM forms of atypical PKCs play a conserved role in memory formation, but the mechanism of formation of these kinases has changed over evolution.

CXCL10 inhibits viral replication through recruitment of natural killer cells in coxsackievirus B3-induced myocarditis

Coxsackievirus (CV)B3 is the primary cause of viral myocarditis. We previously observed CXC chemokine ligand 10 (CXCL10) upregulation in the myocardium early in infection. However, the impact of CXCL10 in CVB3-induced myocarditis is unknown. Using isolated primary mouse cardiomyocytes we demonstrated for the first time that cardiomyocytes can express CXCL10 on interferon-gamma stimulation. To explore the role of CXCL10 in CVB3-induced myocarditis, both CXCL10 transgenic and knockout mice were used. Following CVB3 challenges, the viral titer in the hearts inversely correlated with the levels of CXCL10 at early phase of infection before visible immune infiltration. Furthermore, as compared with the control mice, the decreased virus titers in the CXCL10 transgenic mouse hearts led to less cardiac damage and better cardiac function and vice verse in the knockout mice. This antiviral ability of CXCL10 might be through recruitment of natural killer (NK) cells to the heart and increased interferon-gamma expression early in infection. At day 7 postinfection, with massive influx of mononuclear cells the expression of CXCL10 enhanced the infiltration of CXCR3(+) cells, CD4(+), and CD8(+) T cells, as well as the expression of associated inflammatory cytokines. However, the augmented accumulation of these immune cells and associated cytokines failed to alter the viral clearance and mice survival. These results suggest the protective role of CXCL10 during the early course of CVB3 infection, which is attributed to the recruitment of NK cells. Nonetheless, CXCL10-directed chemoattractant effect is not sufficient for host to clear the virus in the heart.

MicroRNAs-based therapeutic strategy for virally induced diseases

MicroRNAs (miRNAs) are endogenous, short, double-stranded and noncoding RNA molecules that have been identified in a variety of organisms and certain viruses. This group of new molecules is transcribed mainly from the introns and/or exons or intergenic regions and plays important regulatory roles in development and gene expression. Mature miRNAs are typically 20-24 nucleotides in length and regulate target mRNAs post transcriptionally by interactions with partially mismatched sequences in the 3'untraslated regions of these messengers. These interactions result in the suppression of translation or degradation of target mRNAs. At the present, although the biological functions of miRNAs are not completely revealed, a growing body of evidence implicates that miRNA pathway is a new mechanism of gene regulation in both normal and diseased conditions and therefore investigation of miRNA biogenesis and function may add new tools for gene functional study and drug development. In this article, we will briefly review the structure, biogenesis and basic mechanism of action of miRNAs identified in higher organisms and viruses and then focus on the recent progress in research for drug development using the miRNA pathway as a strategy. Particularly, we will discuss the advance, challenge and future directions on antiviral drug development using miRNA as a target or a gene silencing tool for the treatment of viral infections.

Antisense DNA and RNA agents against picornaviruses

Anti-picornaviral antisense agents are part of a broader group of nucleic acid-based molecules developed for sequence-specific inhibition of translation and/or transcription of the target sequence through induced nuclease activity or physical hindrance. Three types of nucleic acid-based gene silencing molecules can be distinguished, including DNA-base antisense oligonucleotides (ASO), nucleic acid enzymes (ribozyme and DNAzyme) and double-stranded small interfering RNA (siRNA or microRNA). These antisense DNA and RNA molecules have been widely studied for gene functional studies and therapeutic purposes. In this review, we focus on drug development using ASO and siRNA strategies to inhibit picornavirus infections. The picornavirus genome organization and life cycle is described, followed by discussion of design considerations, chemical modifications and drug delivery approaches. Recent studies using antisense against picornavirus are reviewed. Finally, we compare the advantages and disadvantages of the antisense agents with those of other therapeutics, taking into consideration their limitations which need to be overcome to achieve the final goal of clinical application.

Focal adhesion kinase mediates the interferon-gamma-inducible GTPase-induced phosphatidylinositol 3-kinase/Akt survival pathway and further initiates a positive feedback loop of NF-kappaB activation

Interferon-gamma-inducible GTPase (IGTP) expression is upregulated in coxsackievirus B3 (CVB3)-infected murine heart and inhibits CVB3-induced apoptosis through activation of the PI3 kinase/Akt pathway. However, the mechanism of this pathway activation is unknown. In this study, using doxcycycline-inducible Tet-On HeLa cells that overexpress IGTP, we have demonstrated that focal adhesion kinase (FAK) is phosphorylated in response to IGTP expression and that transfection of the Tet-On HeLa cells with a dominant negative FAK (FRNK) blocks Akt activation. Furthermore, induction of IGTP also promoted the NF-kappaB activation as evidenced by its enhanced nuclear translocation, binding to transcriptional promoters and increased transcriptional activity. However, FRNK transfection and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 both blocked the IGTP-induced translocation and NF-kappaB activation. Furthermore, silencing NF-kappaB with siRNAs significantly inhibited the phosphorylation of FAK and Akt, but not their total expression levels, indicating that NF-kappaB activation is required for the IGTP-induced activation of FAK and PI3K/Akt. Finally, blocking this survival pathway by transfection of FRNK or silencing of NF-kappaB reduced CVB3 replication and enhanced cell death during CVB3 infection. Taken together, these results suggest that FAK is a mediator upstream of PI3K/Akt and NF-kappaB functions as a downstream effector and also positively regulates the activity of upstream kinases.

Specific interaction of HeLa cell proteins with coxsackievirus B3 3'UTR: La autoantigen binds the 3' and 5'UTR independently of the poly(A) tail

Coxsackievirus B3 (CVB3) is a positive, single-stranded RNA virus. The secondary structure of the 3' untranslated region (3'UTR) of CVB3 RNA consists of three stem-loops and is followed by a poly(A) tail sequence. These stem-loop structures have been suggested to participate in the regulation of viral replication through interaction with cellular proteins that are yet to be identified. In this study, by competitive UV cross-linking using mutated 3'UTR probes we have demonstrated that the poly(A) tail is essential for promoting HeLa cell protein interactions with the 3'UTR because deletion of this sequence abolished most of the protein interactions. Unexpectedly, mutations that disrupted the tertiary loop-loop interactions without affecting the stem-loops did not apparently affect these protein interactions, indicating that secondary structure rather than the high-order structure may play a major role in recruiting these RNA binding proteins. Among the observed 3'UTR RNA binding proteins, we have confirmed a 52 kDa protein as the human La autoantigen by using purified recombinant protein and a polyclonal La antibody. This protein can interact with both the 3' and 5'UTRs independently of the poly(A) tail. Further analysis by two-stage UV cross-linking, we found that the 3' and 5'UTR sequences may share the same binding site on the La protein.

Deposition of tetracene on GaSe passivated Si(111)

The growth of tetracene on GaSe half-sheet passivated Si(111) is investigated under ultrahigh vacuum (UHV) using low-energy electron diffraction (LEED) and photoelectron spectroscopy (PS). A highly ordered thin-film growth was observed in the initial stages of the deposition process. All proposed structures form a coincidence lattice with the underlying substrate, due to the influence of the molecule-substrate interactions and are built up by either flat lying tetracene molecules at low coverage or tilted molecules at higher coverages. Photoelectron spectroscopy (XPS/UPS) shows that the deposited tetracene molecules induce band bending in the silicon substrate. No band bending was observed in the tetracene film, and an interface dipole potential of 0.45 eV was measured between the GaSe passivated Si(111) surface and the tetracene film.

Coxsackievirus B3 proteases 2A and 3C induce apoptotic cell death through mitochondrial injury and cleavage of eIF4GI but not DAP5/p97/NAT1

By transfection of Coxsackievirus B3 (CVB3) individual protease gene into HeLa cells, we demonstrated that 2A(pro) and 3C(pro) induced apoptosis through multiple converging pathways. Firstly, both 2A(pro) and 3C(pro) induced caspase-8-mediated activation of caspase-3 and dramatically reduced cell viability. Secondly, they both activated the intrinsic mitochondria-mediated apoptosis pathway leading to cytochrome c release from mitochondria and activation of caspase-9. However, 3C(pro) induced these events via both up-regulation of Bax and cleavage of Bid, and 2A(pro) induced these events via cleavage of Bid only. Nevertheless, neither altered Bcl-2 expression. Thirdly, both proteases induced cell death through cleavage or down regulation of cellular factors for translation and transcription: both 2A(pro) and 3C(pro) cleaved eukaryotic translation initiation factor 4GI but their cleavage products are different, indicating different cleavage sites; further, both 2A(pro) and 3C(pro) down-regulated cyclic AMP responsive element binding protein, a transcription factor, with 2A(pro) exhibiting a stronger effect than 3C(pro). Surprisingly, neither could cleave DAP5/p97/NAT1, a translation regulator, although this cleavage was observed during CVB3 infection and could not be blocked by caspase inhibitor z-VAD-fmk. Taken together, these data suggest that 2A(pro) and 3C(pro) induce apoptosis through both activation of proapoptotic mediators and suppression of translation and transcription.

Prognostic model to predict survival following first-line chemotherapy in patients with metastatic gastric adenocarcinoma

BACKGROUND

This study was to devise a prognostic model for metastatic gastric cancer patients undergoing first-line chemotherapy.

PATIENTS AND METHODS

A retrospective analysis was carried out on 1455 gastric cancer patients, who received first-line chemotherapy from September 1994 to February 2005.

RESULTS

At multivariate level, poor prognostic factors were no previous gastrectomy [P = 0.003; relative risk (RR), 1.191; 95% confidence interval (CI) 1.061-1.338], albumin < 3.6 g/dl (P = or <0.001; RR, 1.245; 95% CI 1.106-1.402), alkaline phosphatase > 85 U/l (P = or <0.001; RR, 1.224; 95% CI 1.092-1.371), Eastern Cooperative Oncology Group performance status of two or more (P = or <0.001; RR, 1.690; 95% CI 1.458-1.959), the presence of bone metastases (P = 0.001; RR, 1.460; 95% CI 1.616-1.836), and the presence of ascites (P = or < 0.001; RR, 1.452; 95% CI 1.295-1.628). Of 1434 patients, 489 patients (34.1%) were categorized as low-risk group (zero to one factors), 889 patients (62.0%) as intermediate-risk group (two to four factors), and 56 patients (3.9%) as high-risk group (five to six factors). Median survival durations for low, intermediate, and high-risk groups were 12.5 months, 7.0 months, and 2.7 months, respectively.

CONCLUSIONS

This model should facilitate the individual patient risk stratification and thus, more appropriate therapies for each metastatic gastric cancer patient.