Abstract 693: Evaluating the role of CXCR2 receptor and its ligand in breast cancer therapy resistance

Breast cancer is the second leading cause of cancer deaths among women after lung cancer, accounting for more than 40,000 deaths each year. Although there has been advancement in the treatment and diagnosis of breast cancer, therapy resistance and relapse are still big hurdles in the way. Recent reports and our preliminary studies suggest that malignant cells that survive the initial chemo- and radiation therapy express higher levels of CXCR2 ligands which might provide a survival benefit to malignant tumors leading to therapy resistance. The specific objective for this study involves targeting CXCR2 receptor and its ligands mediated signaling for therapy resistance in mammary tumor cells. Our hypothesis is that CXCR2 along with its ligands plays an important role in therapy resistance and that targeting this signaling pathway will provide an effective strategy to overcome the problem. We used mammary tumor cells expressing different levels of CXCR2 (Cl66-wt and Cl66-shCXCR2) and examined their response to Paclitaxel and Doxorubicin. We observed significant enhancement of paclitaxel and doxorubicin-mediated toxicity at lower concentrations in Cl66-shCXCR2 cells as compared to Cl66-wt cells. Moreover, we observed an increase in the expression of CXCL1, a CXCR2 ligand, with increasing doses of drugs. However, paclitaxel and doxorubicin induced CXCL-1 levels was significantly lower in Cl66-shCXCR2 cells as compared to Cl66-wt cells. To further validate our findings we selected Cl66 against paclitaxel and doxorubicin resistant cells by treating with increasing doses of these drugs. Cells were maintained in 500nM doxorubicin and 400nM paclitaxel. We analyzed the sensitivity of these cells to doxorubicin and paclitaxel in comparison to wild type parent cells. We observed that resistant cells survive even at higher concentrations (higher than at which they are maintained) of drugs. Although, paclitaxel resistant cells appears to be sensitive at higher doses of paclitaxel when compared to doxorubicin resistant cells in the same set of experiments. Further studies showed an increase in the expression of CXCL1 in the supernatant of these cells after drug treatment. The expression of CXCL1 was higher even at the basal level in the resistant cells in comparison to the parent cells. As it has been shown that expression of CXCR2 ligands increase after chemotherapy, we examined the expression profile of various CXCR2 ligands in these cells at the mRNA level. We observed that these cells express higher levels of CXCL5, CXCL3 and CXCL7, in comparison to parent Cl66 cells. Together, these results demonstrate that i) CXCR2 and its ligand-mediated signaling plays an important role in the drug resistance of mammary tumors cells; ii) that paclitaxel seems to be more effective against mammary tumor cells in comparison to doxorubicin; and iii) targeting CXCR2 expression enhanced chemotherapeutic responses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 693. doi:10.1158/1538-7445.AM2011-693

Abstract 312: Disruption of chromosomal locus 1p36 differentially modulates TAp73 and ΔNp73 expression and aggressiveness in non-Hodgkin's lymphoma

Consistent cytogenetic aberrations and the consequent molecular alterations have considerably facilitated the classification of non-Hodgkin's lymphoma (NHL). A cytogenetic abnormality involving chromosome region 1p36 is frequently detected in NHL cases and is associated with a poor prognosis and high risk of transformation from an indolent to a more aggressive NHL subtype. However, the molecular events mediating the biological consequences of this cytogenetic abnormality are poorly understood. TP73 is one of the most distally located candidate genes at the 1p36 locus, and is likely to be disrupted or deleted. Furthermore, we have observed frequent loss of heterozygosity in the P73 locus using fluorescence in situ hybridization (FISH) in NHL cases with the 1p36 abnormality. TP73 gene function is controlled by harmony between two isoforms with opposing functions, the full length TAp73 protein (pro-apoptotic) and the NH2-terminally truncated ΔNp73 protein (anti-apoptotic through antagonizing both TAp73 and p53). To determine whether 1p36 abnormalities alter p73 expression, we measured the mRNA expression of TAp73 and ΔNp73 by real-time PCR in diagnostic specimens of cytogenetically characterized NHL cases with and without 1p36 disruption. We observed a down-regulation of TAp73 in NHL cases with and without 1p36 disruption. However, there was a significant increase in the ΔNp73 expression (p<0.01) resulting in a significantly up-regulated (p<0.01) ΔNp73:TAp73 ratio among NHL cases harboring 1p36 abnormalities compared to NHL cases without 1p36 abnormalities. To evaluate the functional significance of this imbalance, we performed immmunohistochemical analysis on diagnostic biopsy specimens from NHL cases with and without 1p36 abnormalities using TAp73, ΔNp73, cleaved caspase 3 (an apoptosis marker), and PCNA (a proliferation marker) antibodies on a tissue microarray. We observed a statistically-significant negative correlation between the ΔNp73:TAp73 ratio and the apoptosis marker cleaved caspase 3 (r=−0.614; p=0.015); and a significant positive correlation between ΔNp73 and the proliferation marker PCNA (r=0.532; p=0.041), indicating increased proliferation and decreased apoptosis with up-regulated ΔNp73. Additionally, we observed a significant positive correlation between TAp73 and cleaved caspase 3 (r=0.772; p=0.001), thus associating the TAp73 isoform with apoptosis. Together, our data demonstrates that 1p36 disruption leads to differential regulation of p73 gene expression, resulting in an imbalance in TP73 isoform expression (gain of ΔNp73 and loss of TAp73), with diminished apoptosis and increased proliferation, thus explaining the prognostic effect of 1p36 disruption. These findings provide new insight into the differential regulation of p73 gene expression that is mediated by this cytogenetic abnormality.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 312. doi:10.1158/1538-7445.AM2011-312

Abstract 1507: Ectopic expresion of cathepsin G in mammary tumor cells and its role in tumor growth and osteolytic bone metastasis

Breast cancer has a high predilection to metastasize to the bone microenvironment. The resulting lesions are predominantly osteolytic and are associated with the resulting morbidity and mortality. We have demonstrated that tumor bone interaction plays an important role in osteolytic bone metastasis mediated by dysregulation of a unique set of genes. Among these genes several proteases have been found to be up-regulated at the tumor-bone interface, one of these is Cathepsin G, a serine protease. These proteases act as modulators between the tumor and stroma. Previously, we have shown that both malignant cells and osteoclasts at the TB-interface express higher levels of Cathepsin G, which is critical for osteolytic bone metastasis. The precise role of tumor and/or host-derived Cathepsin G in osteolytic bone metastasis is not known. In this report, we examined the contribution of tumor-derived Cathepsin G by testing the hypothesis that ectopic expression of Cathepsin G modulates malignant cell phenotype, osteoclast recruitment and activation, and osteolytic metastasis. We generated stable mammary tumor cell lines constitutively expressing Cathepsin G (Cl66-CTSG). Cathepsin G-expressing tumor cells showed diminished in vitro cell proliferative potential and in vivo mammary fat pad tumor growth as compared to vector control transfected Cl66-CMV cells. We demonstrated that Cathepsin G-overexpressing tumor cells induced osteoclast activation and differentiation in vitro and tumor-induced osteolysis in vivo. Our data suggest that tumor-derived Cathepsin G might have distinct tumor modulating activities in the bone microenvironment by regulating cell proliferation and osteoclast recruitment and activation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1507. doi:10.1158/1538-7445.AM2011-1507

Abstract 733: A therapeutic opportunity in melanoma: Targeting CXCR1/2-dependent signaling attenuates therapy resistance

Advanced melanoma is one of the most intractable tumors, due to its insensitivity to all current treatment. Systemic chemotherapy is still considered the mainstay of treatment for advanced melanoma with limited survival impact. Failure of most agents is attributed to development of therapy resistance. Our previous findings demonstrate that CXCL-8 is a critical mediator in tumor growth, invasion, and angiogenesis. Two high affinity receptors for CXCL-8, CXCR1 and CXCR2, are differentially expressed on melanoma and endothelial cells. Based on these observations, we hypothesize that targeting CXCR1/2-dependent signaling will attenuate chemotherapy resistance and will synergistically enhance chemotherapeutic response for malignant melanoma. We used human melanoma cell lines A375P (low metastatic) and A375SM (highly metastatic), which express low and high levels of CXCL-8 respectively. First, we evaluated the role of CXCR1/2 ligands in chemo-resistance. CXCL-1 and -8 mRNA and protein expression was analyzed by quantitative realtime PCR and enzyme-linked immunosorbant assay, following treatment of dacarbazine and temozolomide. A significant increase in the CXCL-1 and -8 levels was observed in A375P and A375SM cells which was dependent on concentration and duration of chemotherapeutic treatment. In order to test whether blocking CXCR1/2 expression using genetic knock-down modulates chemotherapeutic responses, we used A375SM cells expressing different levels of CXCR1 and CXCR2. Our data suggest that knockdown of CXCR1 significantly enhanced the cytotoxic effect of dacarbazine in vitro. However, we did not observe a similar response in melanoma cells knocked down for CXCR2. Taken together, our preliminary data demonstrate that melanoma cells that survive chemotherapy express higher levels of CXCR1/2 ligands and targeting the CXCR1/2-dependent pathway might be a potential therapeutic approach to be combined with chemotherapy in advanced melanoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 733. doi:10.1158/1538-7445.AM2011-733

Awareness, perception and myths towards swine flu in school children of Bareilly, Uttar Pradesh

The deadly disease swine flu is, without a speck of doubt, causing a massive havoc among the common people of India and has created fear across the various strata of the society. The objective was to find out the awareness, perception, and myths of school going children of class 9 th to 12 th toward swine flu. The present cross-sectional study was carried out in two randomly selected (using random number table) senior secondary schools of Bareilly among 400 students of class 9 th to 12 th . A total of 200 students were selected from each school. Chi-square test was applied for statistical analysis. Almost all the students (97.75%) have heard about of swine flu and are aware of it as a disease entity. Fever was found to be the main symptom while coughing and sneezing were main way of spread of swine flu known to them. About 97% of the students mention use of mask as most effective way to prevent them from swine flu. Knowledge of availability of medicine was present in less than half of the students. TV was found to be the main source from which they get knowledge (79%), and they are trying to get knowledge (53.2%) of swine flu. Among them, 74% students were taking precaution against swine flu.

Zoonotic infections of buffalopox in India

Four outbreaks of buffalopox in domestic buffaloes, with considerable mortality with high case fatality rates in young buffalo calves and high morbidity with significant productivity loss in terms of reduction in milk yield in adult animals along with severe zoonotic infection in milk attendants were recorded at various places in India, during 2006-2008. In buffaloes, the pox lesions were confined to udder and teats of the majority of the affected animals, and in few animals the lesions were appeared on the hindquarters, indicating generalized infection. The overall disease morbidity, mortality and case fatality rate were 6.8%, 0.7% and 11.4% respectively. Milkers developed pox-like lesions on the hands, forearms and forehead accompanied by fever, axillary lymphadenopathy and general malaise. The causative agent of the outbreaks, buffalopox virus (BPXV), was confirmed upon virus isolation in cell culture, electron microscopy, A-type inclusion (ATI) and ankyrin repeat protein (C18L) gene-specific polymerase chain reactions (PCR). Further, sequence analysis of the BPXV isolates from human and buffalo showed more identity of ATI and C18L genes sequences with that of other orthopoxviruses at nucleotide and amino acid levels and confirmed a close relationship of BPXV with Vaccinia virus (VACV) or VACV-like viruses. Considering the zoonotic impact and productivity losses of buffalopox infection, the control measures are imperative in curtailing economic and public health impact of the disease.

Autoimmune pancreatitis presenting as a pancreatic mass mimicking malignancy

Autoimmune pancreatitis is a rare cause of chronic pancreatitis and pancreatic mass. We describe a case of focal autoimmune pancreatitis in a 51-year-old man presenting with obstructive jaundice and pancreatic mass, mimicking malignancy. The immunological test was suggestive of autoimmune pancreatitis, and the patient responded well to a course of steroids, with complete resolution of the pancreatic mass. Autoimmune pancreatitis, therefore, must be kept in mind as a differential diagnosis of pancreatic mass. Recognition of this disease by its typical radiological and serological findings may help to avoid unnecessary surgical resection.

Left-ventricular noncompaction in a pediatric population: predictors of survival

Left-ventricular noncompaction (LVNC) is an echocardiographic finding of increasing frequency in pediatrics; however, predictors of outcomes have been difficult to identify. We conducted a retrospective review of pediatric patients at the Morgan Stanley Children's Hospital of New York from January of 1993 to September of 2009 to identify predictors of the primary outcome of death or heart transplantation. LVNC was identified in 50 patients, 34 of them < 1 year of age. Death or transplantation occurred in 26 patients, with a median survival of 1.17 years after presentation. Patients surviving 1 year after presentation had 75% conditional survival, and patients surviving 2 years after presentation had 92% conditional survival. Hemodynamic instability, poor ventricular function, and LV dilatation were each independent predictors of poor outcome. Of the 21 patients who presented with hemodynamic instability, 17 died or underwent transplantation at a median of 0.08 years after presentation. In conclusion, LVNC is recognized more in younger patients; however, age is not a predictor of outcome. Patients who present with hemodynamic instability and poor ventricular function have decreased transplant-free survival, and most poor outcomes occur within the first year after presentation. Therefore, early listing for transplant may lead to better outcomes in this population.

Optimizing tillage schedule for maintaining activity of the arbuscular mycorrhizal fungal population in a rainfed upland rice (Oryza sativa L.) agro-ecosystem

Rainfed uplands in India are predominantly mono-cropped with rice (Oryza sativa L.) in the wet season (June/July to September/October) and grown under aerobic soil conditions. The remaining fallow period (winter followed by summer) of about 8-9 months leads to natural crash in the population of native arbuscular mycorrhizal fungi (AMF) in the soil. Attempts have been made to minimize this population crash by reducing soil disturbance-induced deleterious effects on native AMF activity of improperly scheduled off-season tillage, an agronomic recommendation for weed and disease (soil-borne) management, practiced by the upland farmers. On-farm (farmers' field) evaluation of effects of all suitable off-season tillage schedule combinations on rice during wet seasons of 2004, 2005, and 2006 revealed that a maximum of two off-season tillage schedules with a minimum gap of 13 weeks between them minimized the population crash of native AMF with a concomitant increase in phosphorus (P) uptake and grain yield of upland rice (variety "Vandana").

Prevalence of classical swine fever virus in India: a 6-year study (2004-2010)

A study was undertaken regarding the prevalence of classical swine fever virus (CSFV) antibodies and antigens in sera and suspected tissue samples of domestic pigs. The samples were received between January 2004 and September 2010. A total of 594 serum samples from 12 states and 287 tissue samples from 13 states of India were tested using commercial enzyme-linked immunosorbent assay (ELISA) kits. The mean prevalence of CSFV antibodies in suspected sera was 63.3% (376/594), whereas 76.7% (220/287) of the suspected samples were found to contain CSFV antigen. The high prevalence of CSFV antibodies suggests that the disease is endemic in the country. This baseline data will be of use in the formulation of control and eradication programmes.

Antitumor activity of nifurtimox is enhanced with tetrathiomolybdate in medulloblastoma

Medulloblastoma, a neuroectodermal tumor arising in the cerebellum, is the most common brain tumor found in children. We recently showed that nifurtimox induces production of reactive oxygen species (ROS) and subsequent apoptosis in neuroblastoma cells both in vitro and in vivo. Tetrathiomolybdate (TM) has been shown to decrease cell proliferation by inhibition of superoxide dismutase-1 (SOD1). Since both nifurtimox and TM increase ROS levels in cells, we investigated whether the combination of nifurtimox and TM would act synergistically in medulloblastoma cell lines (D283, DAOY). Genome-wide transcriptional analysis, by hybridizing RNA isolated from nifurtimox and TM alone or in combination treated and control cells (D283) on Affymetrix exon array gene chips was carried out to further confirm synergy. We show that nifurtimox and TM alone and in combination decreased cell viability and increased ROS levels synergistically. Examination of cell morphology following drug treatment (nifurtimox + TM) and detection of caspase-3 activation via Western blotting indicated that cell death was primarily due to apoptosis. Microarray data from cells treated with nifurtimox and TM validated the induction of oxidative stress, as many Nrf2 target genes (HMOX1, GCLM, SLC7A11 and SRXN1) (p<10(-5)) were upregulated. Other genes related to apoptosis, oxidative stress, DNA damage, protein folding and nucleosome formation were differentially involved in cells following treatment with nifurtimox + TM. Taken together, our results suggest nifurtimox and TM act synergistically in medulloblastoma cells in vitro, and that this combination warrants further studies as a new treatment for medulloblastoma.

Phenotypic and genotypic methods for the detection of methicillin resistant coagulase negative staphylococci: a comparative study

CONS are the major cause of nosocomial infection in last decade and methicillin resistant CoNS has emerged as a major clinical problem. The present study was to compare different phenotypic methods with genotypic method PCR, for the detection of methicillin resistance in CoNS. 100 CoNS isolates from different samples were studied for the detection of mecA gene. PCR was considered as "gold standard". Oxacillin and cefoxitin antibiotics were used for different phenotypic tests (DD, Agar dilution and MHOX). The sensitivities of oxacillin and cefoxitin disks for all CONS were found to be 92.30% and 88.46% respectively and the specificities were 87.5% and 100% respectively. The sensitivities of the agar dilution test for oxacillin and cefoxitin were 86.53% and 80.76%, respectively, where as the specificities were 79.16% and 85.41%, respectively. The sensitivity of MHOX was observed to be 96.16% and specificity 72.91%. Cefoxitin D.D and oxacillin AD methods could be used as initial test for the determination of methicillin resistance in CoNS isolates. The result of MHOX shows that it could be the best single method for the evaluation of oxacillin resistance mediated by the mecA gene for all CoNS species.

Cloning and phylogenetic analysis of Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) from Indian dromedaries (Camelus dromedarius)

The cDNAs of two proinflammatory cytokines viz., IL-6 and TNF-α from dromedarian camels were amplified by PCR using bactrian camel sequences and subsequently cloned for sequence analysis. Relationship based on amino acid revealed that dromedarian camel IL-6 shared 99.5% identity both at nucleotide and amino acid level with bactrian camel IL-6 and in case of TNF-α, the identity of dromedarian camel was 99.4% and 99.1% at nucleotide and amino acid level, respectively with that of bactrian camel. Phylogenetic analysis based on their amino acid sequences indicated the close relationship in these cytokine genes between dromedarian camel and other members of camelids.

Prospective randomized clinical trial comparing bite force in 2-mm locking plates versus 2-mm standard plates in treatment of mandibular fractures

PURPOSE

To compare the efficacy of the 2-mm locking miniplates to 2-mm standard miniplates in the osteosynthesis of mandibular fractures on the basis of clinical parameters and bite force recording.

PATIENTS AND METHODS

A prospective randomized clinical trial was conducted at the Faculty of Dental Science, CSMMU (formerly King Georges Medical College), Lucknow, India, from January 1, 2007, to January 31, 2008, to treat consecutive mandible fractures. The patients were randomly divided into 2 groups. The patients underwent osteosynthesis--group 1 with Synthes 2-mm locking titanium miniplates and group 2 with Synthes 2-mm nonlocking titanium miniplates. The cause of trauma, the number of days from injury to surgery, average age, gender, and site distribution were all reviewed. The assessment of the patients was done at 1, 3, and 6 weeks and 3 months using the clinical parameters and bite force recording.

RESULTS

A total of 20 patients with 32 fractures met the inclusion criteria. In our study, a statistically significant difference was not found in the clinical parameters such as pain, swelling, infection, paresthesia, hardware failure, and mobility between the fracture segments. A statistically significant difference was found between the change in bite force from the previous follow-up visit in groups 1 and 2. From 1 week to 3 months, the change in the incisor bite force was significantly greater for group 1 than for group 2. At 6 weeks and 3 months, the change in right molar bite force from the previous follow-up visit was significantly greater for group 1 than for group 2. At the 1-, 3-, 6-week and 3-month follow-up visits, the change in left molar bite force from the previous follow-up visit was significantly greater for group 1 than for group 2.

CONCLUSION

These findings show that the use of locking miniplates plate in mandibular fracture was efficacious enough to bear the masticatory loads during osteosynthesis of the fracture. The locking miniplates provide the advantage of a greater bite force, with clinical results almost similar to those seen with nonlocking miniplate osteosynthesis.

Ossicular chain status in chronic suppurative otitis media in adults

This study was conducted to find out the status of the ossicles in cases of chronic suppurative otitis media (CSOM). One hundred and fifty cases of CSOM, who underwent surgery, were included and their intra-operative ossicular chain findings noted. Ossicular erosion was found to be much more common in unsafe CSOM than in safe CSOM. Malleus was found to be the most resistant ossicle to erosion whereas incus was found to be the most susceptible.

Single miniplate osteosynthesis in angle fracture

Aim:

The present study was designed to study the feasibility of single miniplate osteosynthesis in the fracture of angle of mandible.

Materials and Methods:

in this study 110 patient were included and treated with single miniplate osteosynthesis at upper border along champy's line of osteosynthesis.

Results:

All the cases were treated successfully, common complications which we have observed in this study, cosmetic disfigurement, delayed union, infection, wound dehiscence and paresthesia.

Conclusion:

Single miniplate fixation in unfavorable fracture is questionable and hence these fracture require some alternative method (locking plate, etc.) for fixation.

The modification of siRNA with 3' cholesterol to increase nuclease protection and suppression of native mRNA by select siRNA polyplexes

Polymer-siRNA complexes (siRNA polyplexes) are being actively developed to improve the therapeutic application of siRNA. A major limitation for many siRNA polyplexes, however, is insufficient mRNA suppression. Given that modifying the sense strand of siRNA with 3' cholesterol (chol-siRNA) increases the activity of free nuclease-resistant siRNA in vitro and in vivo, we hypothesized that complexation of chol-siRNA can increase mRNA suppression by siRNA polyplexes. In this study, the characteristics and siRNA activity of self assembled polyplexes formed with chol-siRNA or unmodified siRNA were compared using three types of conventional, positively charged polymers: (i) biodegradable, cross-linked nanogels (BDNG) (ii) graft copolymers (PEI-PEG), and (iii) linear block copolymers (PLL10-PEG, and PLL50-PEG). Chol-siRNA did not alter complex formation or the resistance of polyplexes to siRNA displacement by heparin but increased nuclease protection by BDNG, PLL10-PEG, and PLL50-PEG polyplexes over polyplexes with unmodified siRNA. Chol-CYPB siRNA increased suppression of native CYPB mRNA in mammary microvascular endothelial cells (MVEC) by BDNG polyplexes (35%) and PLL10-PEG polyplexes (69%) over comparable CYPB siRNA polyplexes but had no effect on PEI-PEG or PLL50-PEG polyplexes. Overall, these results indicate that complexation of chol-siRNA increases nuclease protection and mRNA suppression by select siRNA polyplexes. These results also suggest that polycationic block length is an important factor in increasing mRNA suppression by PLL-PEG chol-siRNA polyplexes in mammary MVEC.

Small molecule antagonists for CXCR2 and CXCR1 inhibit human colon cancer liver metastases

CXCR1 and CXCR2 are G-protein coupled receptors, that have been shown to play important role in tumor growth and metastasis, and are prime targets for the development of novel therapeutics. Here, we report that targeting CXCR2 and CXCR1 activity using orally active small molecule antagonist (SCH-527123, SCH-479833) inhibits human colon cancer liver metastasis mediated by decreased neovascularization and enhanced malignant cell apoptosis. There were no differences in primary tumor growth. These studies demonstrate the important role of CXCR2/1 in colon cancer metastasis and that inhibition of CXCR2 and CXCR1, small molecule antagonists provides a novel therapeutic strategy.

Anterior craniofacial resection - for paranasal sinus tumors involving anterior skull base

Management of anterior skull base tumors is complex due to the anatomic detail of the region and the variety of tumors that occur in this area. Currently, the "gold standard" for surgery is the anterior craniofacial approach. Craniofacial resection represents a major advance in the surgical treatment of tumors of the paranasal sinuses involving anterior skull base. It allows wide exposure of the complex anatomical structures at the base of skull permitting monobloc tumor resection. This study presents a series of 18 patients with anterior skull base tumors, treated by a team of head-neck surgeons and neurosurgeons. The series included 15 malignant tumors of the nose and paranasal sinuses and 3 extensive benign lesions. All tumors were resected by a combined bi-frontal craniotomy and rhinotomy. The skull base was closed with a pediculated pericranial flap and a split-thickness free skin graft underneath. There were no postoperative problems of wound infection, cerebrospinal fluid-leakage or meningitis. Recurrent tumor growth or systemic metastasis occurred in 3 out of 15 patients with malignant tumors, 6 months to 2 years postoperatively. Craniofacial resection was thus found to give excellent results with low morbidity in malignant lesions and can also be adapted for benign tumors of anterior skull base.

Multifunctional peptide-PEG intercalating conjugates: programmatic of gene delivery to the blood-brain barrier

PURPOSE

To enhance transfection efficacy of pDNA through the application of multifunctional peptide-PEG-tris-acridine conjugates (pPAC) and the formation of biodegradable core-shell polyplexes for gene delivery to the blood-brain barrier (BBB).

METHODS

pPAC-mediated transfection was compositionally optimized in mouse BBB cells (bEnd.3). Cellular uptake and trafficking, and brain accumulation of pDNA was evaluated by fluorescent imaging and histochemistry. We constructed anti-MRP4 siRNA-producing vectors and evaluated the efficacy of MRP4 down-regulation of MRP4 by Western blot and qPCR, and its effect on the uptake of (3)H-AZT, an MRP4 substrate.

RESULTS

A core-shell gene delivery system (GDS) was assembled from pDNA and pPAC, carrying multifunctional peptides with NLS, TAT, and brain-specific BH, or ApoE sequences, and biodegradable pLPEI polyamine. This GDS demonstrated better cellular and nuclear accumulation, and a 25-fold higher transfection efficacy in slow-dividing bEnd.3 cells compared to ExGen500. Inclusion of brain-targeting pPAC enhanced in vivo accumulation of functional pDNA in brain capillaries. Treatment by encapsulated anti-MRP4 siRNA-producing pDNA caused transient down-regulation of MRP4, and, after intravenous injection in Balb/c mice, enhanced AZT uptake in the brain by 230-270%.

CONCLUSIONS

The pPAC represent novel efficient components of GDS that could find various gene therapy applications, including genetic modulation of the BBB.

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice

This study characterized Pokkali-derived quantitative trait loci (QTLs) for seedling stage salinity tolerance in preparation for use in marker-assisted breeding. An analysis of 100 SSR markers on 140 IR29/Pokkali recombinant inbred lines (RILs) confirmed the location of the Saltol QTL on chromosome 1 and identified additional QTLs associated with tolerance. Analysis of a series of backcross lines and near-isogenic lines (NILs) developed to better characterize the effect of the Saltol locus revealed that Saltol mainly acted to control shoot Na+/K+ homeostasis. Multiple QTLs were required to acquire a high level of tolerance. Unexpectedly, multiple Pokkali alleles at Saltol were detected within the RIL population and between backcross lines, and representative lines were compared with seven Pokkali accessions to better characterize this allelic variation. Thus, while the Saltol locus presents a complex scenario, it provides an opportunity for marker-assisted backcrossing to improve salt tolerance of popular varieties followed by targeting multiple loci through QTL pyramiding for areas with higher salt stress.