In vitro chemosensitivity against enzastaurin correlates with gene expression of IL8 and GSK3-beta

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Background: Enzastaurin (E) is an active antitumoral agent which selectively inhibits the β-isoform of protein kinase C (PKC-β). The compound blocks the enzyme’s ATP-binding site and signal transmission is abrogated resulting in the inhibition of neovascularization. The aim of the present study was to correlate gene expression with in vitro chemosensitivity of freshly explanted human tumor specimens. Such correlations in tumors taken directly from patients will help to rationally design subsequent clinical trials. Methods: Soft-agar colony forming assays were performed on freshly biopsied tumor cells exposed to various concentrations of E. Corresponding pieces of tumor specimens were shock-frozen and prepared for RNA isolation and cDNA generation followed by multiplex real-time PCR experiments. Gene expression data were correlated against cloning assay results. Results: Gene expression data of PKC-β1, PKC-β2, IL8RA, IL8RB, IL8, GSK3-β, and TGF-β were correlated against in vitro chemosensitivity pattern of E from 66 samples. After 1h-drug exposure gene expressions in sensitive versus resistant specimens were statistically significant with p = 0.013 for IL8 [median copy number (mcn): 1881 vs. 694; n = 66] and p = 0.012 for GSK3-beta (mcn: 1.6 vs. 7.0; n = 66). No correlation was detected for PKC-β1, PKC-β2, IL8RA, and IL8RB. Detection of TGF-β failed in most samples. Conclusions: Low expression of GSK3-β and high expression of IL8 correlate statistically significantly with increased in vitro sensitivity to E in freshly explanted human tumors. These findings may help direct further clinical development of this compound.

No significant financial relationships to disclose.

Oncolytic adenovirus-mediated transfer of the antisense chk2 selectively inhibits tumor growth in vitro and in vivo

Screening and identifying molecules target to checkpoint pathways has fostered the development of checkpoint-based anticancer strategies. Among these targets, inhibition of chk2 may induce cell death for tumors whose growth depends on enhanced chk2 activity. However, improvement of the potency and specificity of such therapeutics remains a major challenge. To resolve this problem, we constructed M3, a novel recombinant adenovirus with a 27-bp deletion in E1A CR2 region by which to realize tumor-specific replication, and an 829-bp of antisense chk2 fragment inserted into the E3 coding region. In this design, M3 exploited the native adenovirus E3 promoters to express antisense chk2 cDNA in a viral replication-dependent fashion, and preferentially silenced the chk2 gene in tumor cells. In vitro and in vivo assays confirmed that downregulated chk2 expression induced by M3 infection was tumor-specific and virus replication-dependent. Furthermore, systemic administration of M3 combined with a low dose of cisplatin cured 75% (9/12) of orthotopic hepatic carcinoma mouse models that were otherwise resistant to cisplatin. Our results indicated that the upcoming development in this field would improve the antitumor efficacy and maximize the synergistic effect of oncolytic viruses administered with traditional chemotherapy or radiotherapy.

Procaspase-3 enhances the in vitro effect of cytosine deaminase-thymidine kinase disuicide gene therapy on human ovarian cancer

Because the efficacy of genetic prodrug activation therapy (GPAT) using herpes simplex virus thymidine kinase (tk)/ganciclovir (GCV) or Escherichia coli cytosine deaminase (cd)/5-fluorocytosine (5-FC) is not satisfied in early clinical trials and the mechanism of both the GPATs have been shown to lead to the activation of cell apoptotic pathway, we hypothesized that coexpression of procaspase-3, a central downstream executioner of apoptotic pathways, with cd-tk gene leads to enhanced cell death in ovarian cancer cells in vitro. Following transfection with the vectors encoding cd and tk, 5-FC and GCV treatments lead to greater cell death in procaspase-3-expressing clones of 3AO (3AO-caspase-3) than control cells (3AO-pcDNA3), as well as more rapid activation of caspase-3 and more rapid cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP). There is a greater degree of cell apoptotic rate in the procaspase-3-expressing clones than in control cells following the treatment with cd-tk/5-FC + GCV, and apoptosis is the main cell death form. None of these effects is seen following transfection with a control vector that does not encode tk and cd (pBTdel-279). The results strongly suggest that coexpression of procaspase-3 may lead to a significant enhancement of the efficacy of cd-tk/5-FC + GCV, and this strategy would be a novel and promising approach for the treatment of ovarian cancer.

Inhibition of ovarian cancer metastasis by adeno-associated virus-mediated gene transfer of nm23H1 in an orthotopic implantation model

Ovarian cancer is one of the most threatening malignant tumors in females due to the frequent occurrence of metastasis that precedes diagnosis. The present study explored the possibility of preventing ovarian cancer metastasis by promoting nm23H1 expression through adeno-associated virus (AAV)-mediated gene transfer. A cell line of high metastatic potential, SW626-M4, was derived by in vivo selection and used to establish an ovarian cancer metastasis model in the mouse. Liver metastasis and animal survival time were measured after transfer of a recombinant adeno-associated viral vector expressing nm23H1 (AAV-nm23H1) into the aforementioned model. Intraperitoneal injection of AAV-nm23H1 into this orthotopic implantation model of ovarian cancer resulted in (1) expression of the exogenous gene in more than 95% of tumor cells in situ in nude mice; (2) a 60% reduction in the number of animals developing liver metastases; and (3) a 35-day prolongation of median survival time compared with the untreated host group. In conclusion, the results support the feasibility of induction of nm23H1 expression through gene transfer as a therapeutic strategy for preventing metastases and prolonging host survival time, and indicate that AAV vectors deserve attention in the design of future gene therapy approaches to achieving long-term expression of curative genes in vivo.

Inhibition of telomerase enhances apoptosis induced by sodium butyrate via mitochondrial pathway

Telomerase activation represents an early step in carcinogenesis. Increased telomerase activity in cervical cancer suggests a potential target for the development of novel therapeutic drugs. The aim of this study is to investigate the impact of telomerase activity on the biological features of HeLa cells and the possible mechanisms of enhanced apoptosis rate induced by sodium butyrate after telomerase inhibition. We introduced vectors encoding dominate negative (DN)-hTERT, wild-type (WT)-hTERT, or a control vector expressing only a drug-resistance marker into HeLa cells. Thus we assessed the biological effects of telomerase activity on telomere length, cell proliferation, chemosensitivity and radiosensitivity. In order to understand the mechanisms in which DN-hTERT enhances the apoptosis induced by sodium butyrate, we detected the release status of cytochrome c and apoptosis inducing factor (AIF) from mitochondria. Ectopic expression of DN-hTERT resulted in inhibition of telomerase activity, reduction of telomere length, decreased colony formation ability, and loss of tumorigenicity in nude mice. Moreover, DN-hTERT transfected HeLa cells with shortened telomeres were more susceptible to multiple chemotherapeutic agents and radiation. WT-hTERT transfected HeLa cells with longer telomeres exhibited resistance to radiation and chemotherapeutic agents. Our data demonstrate that elevated release level of cytochrome c and AIF from mitochondria might contribute to the enhanced apoptosis in DN-hTERT transfected HeLa cells after treatment with sodium butyrate. Inhibition of telomerase might serve as a promising adjunctive therapy combined with conventional therapy in cervical cancer.

Breast cancer resistance protein-mediated topotecan resistance in ovarian cancer cells

Overexpression of breast cancer resistance protein (BCRP) and mitoxantrone (MX) resistance protein can confer resistance to a variety of cytostatic drugs, such as MX, topotecan (TPT), doxorubicin, and daunorubicin. This study investigates the role of BCRP in resistance of ovarian cancer to TPT treatment. We have developed TPT-resistant human ovarian cancer cell line. Intracellular concentration of fluorescent dye rhodamine 123 (Rh123) was measured by flow cytometry. The expression of several membrane transporter proteins including P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and BCRP were determined by reverse transcription-polymerase chain reaction and Western blotting. The Rh123 concentration in parental cells was approximately three times of those in TPT-resistant cells. In contrast to undetectable level of P-gp messenger RNA (mRNA) and minimal level of MRP1 expression in TPT-resistant cells, overexpression of both the BCRP mRNA and the protein was detected in these cells. Introduction of antisense-phosphorothioate oligonucleotide derived from BCRP mRNA into TPT-resistant cells resulted in a significant increase in the concentration of intracellular Rh123. These results suggested a novel mechanism in which a reduced intracellular drug concentration may be mediated by BCRP gene products in human ovarian cancer cells.

Arsenic trioxide induces apoptosis in cisplatin-sensitive and -resistant ovarian cancer cell lines

Arsenic trioxide (As(2)O(3)), has been used for centuries in traditional Chinese medicine; it has considerable efficacy in the treatment of relapsed acute promyelocytic leukemia, inducing partial differentiation and promoting apoptosis of malignant promyelocytes. Although a number of studies have demonstrated that As(2)O(3) has potent activity against cell growth in a series of leukemia cell lines, little information is available regarding this compound's effect on cell growth in solid tumor cell lines. In this study, we investigated the effects of As(2)O(3)in vitro on ovarian cancer cell lines sensitive (3AO) and resistant (3AO/CDDP) to cisplatin. The 3-(4,5-dimethy-thiazoyl-2-yl)-2,5-diphenyl-tetrazolium bromide assay was used to evaluate cytotoxicity. Flow cytometric analysis was used to determine the apoptosis, cell cycle distribution. We clearly demonstrated that As(2)O(3) induced cell apoptosis and inhibition of cell growth in both the cell lines. Furthermore, we identified that As(2)O(3)-induced apoptosis involved Fas pathway. As(2)O(3) is an active agent against ovarian cancer cells and could be effective in the clinical treatment of ovarian cancer.

Isoflurane exerts antinociceptive and hypnotic properties at all ages in Fischer rats

BACKGROUND

Some anaesthetic agents exhibit an age-dependent analgesic effect, for example nitrous oxide, which is ineffective in newborn rats. We investigated whether a similar time dependency existed for the responses to the volatile anaesthetic isoflurane.

METHODS

The analgesic and hypnotic properties of isoflurane at various ages was assessed using four cohorts of Fischer rats aged approximately 7, 16, and 28 days and adults (11-12 weeks old). Intraplantar administration of formalin mimicked inflammatory pain, and its effects were assessed using immunohistochemical (c-Fos staining) and behavioural paradigms. The hypnotic properties of isoflurane were assessed using loss of righting reflex.

RESULTS

Formalin administration produced a typical nociceptive response observed both behaviourally and immunohistochemically in all age groups; these nociceptive responses were significantly attenuated by isoflurane 0.5% at each age (P<0.05). Interestingly 7-day-old animals showed a significantly more potent hypnotic response than older animals (P<0.01): with adult rats being most resistant to isoflurane induced hypnosis (P<0.05).

CONCLUSION

In contrast to nitrous oxide, isoflurane is an effective antinociceptive agent in neonatal rats. If the data can be extrapolated to clinical scenarios these results suggest that isoflurane may be analgesic in newborns as well as adult humans. In addition, isoflurane is a potent hypnotic, especially in the very young, which is in contrast to the neonate's relative resistance to anaesthesia as assessed by minimum alveolar concentration.

MRI findings of eosinophilic myelomeningoencephalitis due to Angiostrongylus cantonensis

AIM

To study the imaging characteristics of eosinophilic myelomeningoencephalitis due to Angiostrongylus cantonensis using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Seventeen MRI examinations of the brain and spinal cord in five patients with angiostrongyliasis cantonensis of the central nervous system were performed. The final diagnosis was based on typical clinical symptoms, results of blood and cerebrospinal fluid (CSF) tests, and the presence of nematode larvae in the CSF. The sequential MRI follow-up examinations were carried out at a different stage for every patient from 1 to 28 weeks after the onset of symptoms. The features of the lesions in the brain, spinal cord, meninges and nerve roots on MRI were studied, moreover, the development of the lesions was analysed on follow-up MRI.

RESULTS

Abnormalities were demonstrated on MRI in all five cases. They included three cases of meningoencephalitis, one case of encephalitis and one myelomeningitis. The locations and appearances of the lesions were as follows: (1) brain involvement in four cases (including cerebrum in four, cerebellum in two and brain stem in three), and spinal cord involvement in one case. These lesions were diffuse or scattered and appeared as similar or slightly reduced signal intensity on T1-weighted images (T1WI), high signal intensity on T2-weighted images (T2WI) and turbo fluid attenuated inversion recovery pulse sequence (FLAIR) images. After administration of gadolinium chelate (Gd-DTPA), multiple round or oval enhancing nodules, with diameters ranging from 3 to 10 mm, were seen on T1WI, a few lesions appeared as stick-shaped enhancement whose longest measurement was 14 mm. Diffuse or local oedema around the lesion could be seen. (2) Meningeal involvement in four cases, a case of ependymal involvement and a case of nerve root involvement were among them. These lesions appeared as linear or nodular enhancement of the leptomeninges and ependyma, as well as nerve root enhancement. (3) There was a mild ventricular enlargement in two cases. On follow-up MRI lesions were most severe from the 5th week to the 8th week and it took at least 4-8 weeks (1-2 months) for a lesion to resolve completely, the resolution of larger lesion needed more than 22 weeks.

CONCLUSION

Multiple enhancing nodules in the brain and linear enhancement in the leptomeninges were the main features; stick-shaped enhancement was the characteristic sign of the disease on Gd-DTPA enhanced-T1 weighted images.

Soft drink and milk consumption, physical activity, bone mass, and upper limb fractures in children: a population-based case-control study

Carbonated beverages have been reported to increase fracture risk in children but the mechanism is unclear. The aim of this population-based case-control study was to investigate the association between soft drink and milk consumption, physical activity, bone mass, and upper limb fractures in children aged 9-16 years. A total of 206 fracture cases and 206 randomly selected individually matched controls were studied. There were 47 hand fractures; 128 wrist and forearm fractures, and 31 upper arm fractures. An interviewer-administered questionnaire was utilized to retrospectively assess last-year physical activity (including television, computer, and video watching) and to recall the average weekly consumption of milk, colas, and total carbonated drinks. Bone mass at the spine, hip, and total body was assessed by dual-energy X-ray absorptiometry (DXA) and metacarpal morphometry. For total fractures, none of the above drink types was significantly different between cases and controls. For wrist and forearm fractures, there was a positive association between cola drink consumption and fracture risk (OR 1.39/unit, 95% CI: 1.01, 1.91). Cola consumption was significantly correlated with television, computer, and video watching (r = 0.20, P = 0.001) but not bone mineral density or milk drinks. After adjustment for television, computer, and video watching and bone mineral density, the association between cola drinks and fracture risk became nonsignificant (OR 1.31/unit, 95% CI: 0.94, 1.83). No association with other fracture sites was observed. In conclusion, cola, but not total carbonated beverage consumption, is associated with increased wrist and forearm fracture risk in children. However, this association is not independent of other factors and appears to be mediated by television watching and bone mineral density but not by decreased milk intake.

A phase II study of Rituximab in rheumatoid arthritis patients with recurrent disease following haematopoietic stem cell transplantation

Haematopoietic stem cell transplantation (HSCT) has been used recently as an effective therapy in patients with resistant rheumatoid arthritis (RA). Although disease control occurs in the majority of cases, recurrence is common, often coinciding with B-cell reconstitution. We hypothesized that Rituximab, a monoclonal anti-CD20 antibody, would have activity in this group of patients. We treated 10 RA patients (8F:2M, median age 46.5 years), who had recurrent disease post HSCT. All patients received two doses of Rituximab 1 g, 2 weeks apart with no major adverse sequelae and were followed for 12 months. A total of eight out of 10 patients experienced major clinical responses as measured by the American College of Rheumatology (ACR) criteria, with 50-70% improvement in disease parameters. Responses were equivalent to previous responses attained with HSCT. Disease responses were maximal at 4-8 months post Rituximab and correlated with B-cell lymphopenia and a reduction of rheumatoid factor titre. Disease recurrence occurred in 6/9 responders within 12 months and four patients were subsequently retreated, with major responses again attained. This study provides further evidence that B-cell depletion leads to a significant improvement in disease activity in patients with severe RA and provides data for future trials of HSCT and Rituximab therapy.

Analysis of lectin receptors in normal nasal mucosa, nasal polyp, inverted papilloma and papillary adenocarcinoma

In order to investigate the changes in glycoprotein structure in the process of cellular differentiation of the nasal mucosa, formalin-fixed, paraffin-embedded biopsy specimens of normal nasal mucosae, nasal polyps, inverted papillomas and papillary adenocarcinomas were analysed by the Avidin Biotin-Peroxidase Complex technique for the demonstration of peanut agglutinin (PNA) receptors, concanavalin ensifomis agglutinin (ConA) receptors, ulex europeaus agglutinin (UEA-I) receptors, wheat germ agglutinin (WGA) receptors, carcino-embryonic antigen (CEA) and keratin. The quantity and distribution of PNA receptors, ConA receptors, UEA-I receptors and CEA were different, in relation to the varying pathological changes. The results suggest that the glycoprotein structure in the cells of the nasal mucosa will change following their differentiation and malignant transformation, which may be helpful in establishing the diagnosis.

The role of protein kinase C-alpha (PKC-alpha) in malignancies of the gastrointestinal tract

Drugs specifically designed to block cellular signalling proteins are currently evaluated as a new way to treat gastrointestinal tumours. One such "new targeted agent" is aprinocarsen, an antisense oligonucleotide that specifically blocks the mRNA of protein kinase C-alpha (PKC-alpha). Blocking PKC-alpha, an important cellular signalling molecule associated with tumour growth, is anticipated to result in tumour cell arrest and achieve clinical benefits. However, it is not known which patients may benefit most from a specific inhibition of PKC-alpha. Past experience with other novel targeted agents suggests that expression of the target molecule is an important factor for the success of such a specific therapy. Therefore, reviewing the specific role of PKC-alpha in various gastrointestinal tumours may contribute to focus the clinical development of selective or specific PKC-alpha inhibitors, such as aprinocarsen, on those patients with a distinctive PKC-alpha expression pattern.

Imatinib produces significantly superior molecular responses compared to interferon alfa plus cytarabine in patients with newly diagnosed chronic myeloid leukemia in chronic phase

We analyzed molecular responses in 55 newly diagnosed chronic-phase chronic myeloid leukemia (CML) patients enrolled in a phase 3 study (the IRIS trial) comparing imatinib to interferon-alfa plus cytarabine (IFN+AraC). BCR-ABL/BCR% levels were measured by real-time quantitative RT-PCR and were significantly lower for the imatinib-treated patients at all time points up to 18 months, P<0.0001. The median levels for imatinib-treated patients continued to decrease and had not reached a plateau by 24 months. A total of 24 IFN+AraC-treated patients crossed over to imatinib. Once imatinib commenced, the median BCR-ABL/BCR% levels in these patients were not significantly different to those on first-line imatinib for the equivalent number of months. The incidence of progression in imatinib-treated patients, defined by hematologic, cytogenetic or quantitative PCR criteria, was significantly higher in the patients who failed to achieve a 1 log reduction by 3 months or a 2 log reduction by 6 months, P=0.002. A total of 49 patients were screened for BCR-ABL kinase domain mutations. Mutations were detected in two imatinib-treated patients who crossed over from IFN+AraC and both lost their imatinib response. In conclusion, first-line imatinib-treated patients had profound reductions in BCR-ABL/BCR%, which significantly exceeded those of IFN+AraC-treated patients and early measurements were predictive of subsequent response.