Regulation of two key nuclear enzymatic activities by the 7SK small nuclear RNA

7SK is a highly conserved small nuclear RNA (snRNA) in vertebrates. Since its discovery in 1968, little had been known about its function until recently, when 7SK was found to associate with the general transcription elongation factor P-TEFb. Together with the HEXIM1 protein, 7SK sequesters P-TEFb into a kinase-inactive complex, where it mediates HEXIM1's inhibition of P-TEFb. This helps maintain P-TEFb in a functional equilibrium to control transcription, cell growth, and differentiation. Although highly abundant, only a small fraction of 7SK is P-TEFb-bound. Using affinity purification, we have identified APOBEC3C as another 7SK-associated protein. As a member of the APOBEC family that functions in diverse processes through deaminating cytosine in DNA, it is unclear how APOBEC3C's activity is controlled to prevent its mutations of genomic DNA. We show that most of APOBEC3C interact with about half of nuclear 7SK, which suppresses APOBEC3C's deaminase activity and sequesters APOBEC3C in the nucleolus where it could be at a safe distance from most genomic sequences. Because the DNA substrate-binding site in APOBEC3C differs from the region for 7SK binding, 7SK does not act as a substrate competitor in inhibiting APOBEC3C. The demonstration of 7SK's suppression of yet another enzyme besides P-TEFb suggests a general role for this RNA in regulating key nuclear functions.

Pemetrexed (P) in relapsed small cell lung cancer (SCLC): Preliminary results of a phase II trial

7716

Background: Pts with relapsed SCLC have a poor prognosis and few effective treatment options. P is a novel multitargeted antifolate that is active and well-tolerated as a single agent in lung cancer. We undertook a trial to assess the efficacy and safety of single- agent P in both chemosensitive (S) and chemorefractory (R) relapsed SCLC pts. Methods: Eligible pts had limited or extensive- stage SCLC, PS 0 to 2, and only 1 prior chemo regimen. S pts were defined as having had a prior response with disease progression >2 mos from end of 1st-line chemo. R pts were those who progressed while on 1st-line therapy, or had any response but progression <2 mos from end of 1st-line chemo. The initial P dose tested was 500 mg/m2 q 21 d. Planned sample sizes were 36 S pts in a 2-stage sequential fashion with potential early stopping for lack of efficacy or unacceptable toxicity, and 25 R pts in a single-stage design with no stopping rule. The stopping rule was invoked when <3 of 14 qualified S pts responded. The protocol was then amended to evaluate P at 900 mg/m2 in additional cohorts of 40 S and 40 R pts. Pts were to receive folic acid and Vitamin B12 prior to treatment with P. The primary outcome measure was response rate. Results: From 7/04 to 3/06, 121 pts were enrolled, with 116 pts treated. S and R pts were analyzed separately at both dose levels. S pts (n=56): M/F, 29/27; median age 65 (range 43–82); PS 0/1/2, 25/23/8. R pts (n=65): M/F, 31/34; median age 64 (range, 35–85); PS 0/1/2, 16/37/12. *3 S pts treated with P 900 mg/m2 remain with disease control after a minimum of 11 mos of follow-up. Conclusions: Preliminary clinical benefit rates (CR+PR+SD) of 20% and 17.4% achieved respectively in S and R pts treated with P 500 mg/m2 suggest modest activity of single-agent P in relapsed SCLC. P can be given at a dose of 900 mg/m2 without a significant increase in Grades 3–4 toxicities, although this does not appear to increase efficacy.

[Table: see text] [Table: see text]

Portal vein and systemic thromboses in hepatocellular carcinoma

15048

Background: Hemostatic activation may be important for tumor growth and metastasis. Hepatocellular carcinoma (HCC) is commonly associated with portal vein thrombosis (PVT). Very little is known about factors predictive for PVT in patients with HCC or its correlation with systemic venous thromboembolism (VTE). Methods: We conducted a retrospective chart review of 194 patients diagnosed with HCC at the University of Rochester between 1998 and 2004. The primary endpoints of this study were presence of PVT and any systemic VTE. The secondary endpoint was overall survival calculated from time of diagnosis. Univariate and multivariate logistic regression analyses were conducted to assess the association of PVT with a set of clinical covariates, and the survival curve was estimated using the method of Kaplan-Meier. Results: The mean age of the total population was 60.4 ± 11.9, and one-third of the patients underwent liver transplant. The incidence of PVT in the total population was 31% (60/194) with a higher incidence in the non-transplant group compared to transplanted patients (34% vs. 24%; p= 0.08). In univariate analysis, advanced stage, major vessel involvement, higher MELD score, higher Child-Turcotte-Pugh (CTP) classification, lower serum albumin, elevated serum bilirubin, elevated serum alpha-fetoprotein (AFP) level, and elevated INR were associated with development of PVT (p <0.05 for each). In multivariate analysis CTP class, stage, major vessel involvement, serum albumin, and serum AFP were independently and significantly associated with PVT (p <0.05 for each). The presence of PVT was associated with reduced survival (median survival 4.61 months for those with PVT versus 17.55 months for those without PVT, HR 2.01, p <0.001). The incidence of systemic VTE in the total population was 6.7%, and patients with PVT had a higher rate of systemic VTE compared to patients without PVT (11.5% vs. 4.4%; p 0.044). Conclusions: PVT is common in patients with HCC and is associated with worse outcomes. The correlation between PVT and systemic VTE suggests a common mechanism of hemostatic activation. Advanced stage, higher CTP class, major vessel involvement, and serum albumin and AFP levels are predictive of PVT. Identifying patients at high-risk for PVT and instituting prophylaxis may affect HCC outcomes.

No significant financial relationships to disclose.

Clinical validation of a self-organizing map (SOM)-based quantitative prediction algorithm to determine the site of origin of cancers of unknown primary (CUP)

21064

Background: As many as 100,000 new cases of CUP are diagnosed each year in the United States. Identifying the site of origin of the CUP is critical for effective cancer management, and several genomic assays have been developed to facilitate this process. The genomic profile generated does not always fit into a discrete classification, however, and communicating results in a simple, easily understood format is important to clinical practice. Methods: We created a novel algorithm that combines SOMs for qualitative visualization with a quantitative clustering algorithm to predict the site of origin of metastatic cancers. We trained the algorithm on a dataset of 231 tumor-bank samples from 9 primary sites. After fixing all thresholds and algorithm settings, we evaluated the algorithm's performance in making a correct first or second prediction on a second blinded and independent dataset of 63 samples. Results: The algorithm correctly predicted the primary site in 82% of cases with the first prediction, and 89% with either the first or second prediction. The map visualization component helped to reduce the biological and mathematical complexity of the test into an easy to understand format for practicing physicians. The map- based approach allowed a fuzzy prediction that complements a class-based prediction and provides substantial additional information on the relationship between an unknown specimen and other related specimens of known provenance. Conclusion: CUP is a formidable clinical problem; correctly identifying the primary site and rendering specific treatment translates into improved patient outcomes. The use of an SOM to depict the genomic profile of the tumor specimen makes it easier for the clinician or pathologist to understand what tumor type the CUP most closely resembles and facilitates further diagnostic or therapeutic decisions.

No significant financial relationships to disclose.

Phase III study of immediate versus delayed docetaxel after induction therapy with gemcitabine plus carboplatin in advanced non-small cell lung cancer: Updated report with survival

LBA7516

Background: Gemcitabine (G) plus carboplatin (C) therapy is active in patients with advanced non-small-cell lung cancer (NSCLC). For nonprogressing patients, optimal timing of second-line therapy with a non-cross-resistant agent is unclear. This Phase III, randomized trial assessed the efficacy and safety of docetaxel (D) administered either immediately after GC induction therapy or upon disease progression (PD). Methods: Patients having either Stage IIIB with pleural effusion or Stage IV NSCLC were enrolled. Prior chemotherapy for NSCLC was not permitted. For GC induction, G 1000 mg/m2 was administered on Days 1, 8 followed by C AUC 5 on Day 1. After four 21-day cycles, nonprogressors were randomized to either the immediate D group (D 75 mg/m2 administered on Day 1 every 21 days, for a maximum of 6 cycles) or the delayed D group (patients given best supportive care after randomization and the same D regimen after first evidence of PD) treatment arms. Primary endpoint was overall survival (OS). Additional analyses included response rates, toxicity and progression-free survival (PFS). Results: Results are summarized in the table below. OS was not statistically different (p=0.071) between the two D arms. However, 31 patients (20.1%) in the delayed D arm and 38 patients (24.8%) in the immediate D arm were censored for OS analysis. PFS analysis (from randomization to first evidence of PD or death) showed a statistically significant (p=<0.0001) improvement in the immediate D arm. D given to NSCLS patients immediately after GC induction did not increase toxicity. Conclusions: Comparison of PFS for each D arm suggests a possible clinical benefit for immediate D therapy. However, even though OS trended in favor of immediate D therapy, the OS result did not reach statistical significance. The implications of these results will be discussed.

[Table: see text] [Table: see text]

The impact of shortened vitamin supplementation lead-in time before pemetrexed (P) in patients with relapsed small cell lung cancer (SCLC)

7726

Background: Clinical studies of P have shown less overall toxicity and reductions in Grades 3–4 hematologic and nonhematologic toxicities when pts are pretreated with folic acid and vitamin B12. Current recommendations are to give folic acid 350 μg - 1,000 μg by mouth for at least 5 of 7 days prior to the 1st dose of P, and 1 injection of vitamin B12 1000 μg during the week preceding the 1st P dose. Treatment delay to allow this supplementation may be clinically undesirable, particularly in pts with aggressive malignancies. A trial evaluating single-agent P for the treatment of relapsed SCLC gave us opportunity to observe the effects of a shortened lead-in time for vitamin supplementation. Methods: We reviewed data from a U.S. trial designed to assess the safety and efficacy of single-agent P in chemosensitive and chemorefractory relapsed SCLC pts. Eligible pts had limited or extensive-stage SCLC, PS 0 to 2, and 1 prior chemo regimen. Pts received P doses of 500 mg/m2 or 900 mg/m2 q 21 d. The protocol required the administration of folic acid for at least 5 of 7 days prior to the 1st P dose, and vitamin B12 administration on Day 1, Cycle 1, or up to 14 days prior to the 1st P dose. Included in the analysis were pts who received at least 1 dose of folic acid prior to 1st P dose. We then analyzed preliminary toxicity results for pts receiving vitamin B12 for 0–3, 4–6 and =7 days prior to 1st P dose. Results: From 7/2004 to 3/2006, 116 pts were treated with P. At baseline M/F 57%/59%; median age 64.5 years (range 35–85); PS 0/1/2 was 39%/57%/20%. Cycle 1 vitamin administration timing data is available for 109 pts. Data for all 116 pts will be reported at time of meeting. Because toxicities observed between the 2 P doses were not significantly different, the combined toxicities for both dosing groups are reported here. Conclusions: Based on this data, Vitamin B12 given less than 7 days prior to P does not appear to be associated with increased serious toxicities.

No significant financial relationships to disclose.

[Table: see text]

MicroRNA regulation in mantle cell lymphoma

8056

Mantle Cell Lymphoma (MCL) represents only 5–10% of all non-Hodgkins lymphomas, making it an uncommon but difficult form of lymphoma to treat. It has the worst prognosis among the B cell lymphomas with median survival of three years. The genetic hallmark of MCL is a t(11;14) q32 translocation which results in ectopic and dysregulated expression of cyclin D1. Recent comparative genomic hybridization studies have identied Syk as another gene important in the pathogenesis of MCL. Previous studies have suggested that post transcriptional regulation of Cyclin D1 and Syk may be important the pathogenesis of in MCL. MicroRNAs are a new class of abundant small RNAs that play important regulatory roles at the post transcriptional level by binding to the 3’ untranslated region (UTR) of mRNAs blocking either their translation or initiating their degradation. There have been numerous reports of misregulation of microRNAs and their targets in human cancers. We hypothesized that altered microRNA regulation of cyclin D1 and/or Syk may be present in MCL. Based on bioinformatics, we identified 8 microRNAs and their putative docking sites in either Cyclin D1 and Syk. We then examined their integrity in MCL cell lines, and identified a mutation in the 3’UTR of Syk at the docking site of 1 mir-452* and a SNP in mir-458. Using a GFP reporter construct with the mutated Syk 3’UTR we demonstrated that this mutation resulted in altered microRNA function. We also show that mimics of the microRNA leads to down regulation of Syk protein. This data suggests that microRNA regulation of important genes in MCL may be compromised and play a role in the development and progression of this disease.

No significant financial relationships to disclose.

MICROSURGICAL TREATMENT OF SYMPTOMATIC SACRAL PERINEURIAL CYSTS

OBJECTIVE

The aim of this study was to investigate the microsurgical results of symptomatic sacral perineurial cysts of 11 patients and to discuss the treatment options of the past 10 years.

METHODS

We retrospectively reviewed the records of 11 patients with symptomatic sacral perineurial cysts who underwent microsurgical treatment at Tongji Hospital, Huazhong University of Science and Technology from 1993 through 2006. The philosophy was to perform total or partial cyst wall removal, to imbricate the remaining nerve sheath if possible, and to repair local defect with muscle, Gelfoam (Pharmacia & Upjohn, Kalamazoo, MI), and fibrin glue. Patient outcomes were assessed by comparing the preoperative and postoperative examination results. The average follow-up time obtained from return visits to the neurosurgery clinic or by telephone questionnaires ranged from 2 months to 13 years. A literature search and analysis of current treatment options were performed.

RESULTS

Nine of the 11 patients (82%) experienced complete or substantial relief of their preoperative symptoms. One patient (Patient 4) experienced worsening of bladder dysfunction after surgery and recovered slowly to subnormal function during the subsequent 2 months. The symptoms of Patient 9 did not resolve, and magnetic resonance imaging showed that the cyst had reoccurred. The patient underwent reoperation 3 months later without any improvement. One patient (Patient 11) experience a cerebrospinal fluid leakage complication. Neither new postoperative neurological defects nor infection were observed in our series. In the literature, there are six different treatment options under debate and controversially discussed.

CONCLUSION

Microsurgical treatment yielded the best long-term resolution of patient symptoms to date and should be recommended to appropriately selected patients.

Dual EGFR and mTOR targeting in squamous cell carcinoma models, and development of early markers of efficacy

The epidermal growth factor receptor (EGFR) is a validated target in squamous cell carcinoma (SCC) of the head and neck. Most patients, however, do not respond or develop resistance to this agent. Mammalian target of rapamycin (mTOR) is involved in the pathogenesis of SCC of the head and neck (SCCHN). This study aimed to determine if targeting mTOR in combination with EGFR is effective in SCC, and to develop early pharmacodynamic markers of efficacy. Two SCC cell lines, one resistant (HEP2) and one of intermediate susceptibility (Detroit 562) to EGFR inhibitors, were xenografted in vivo and treated with an mTOR inhibitor (temsirolimus), an EGFR inhibitor (erlotinib) or a combination of both. Temsirolimus exerted superior growth arrest in both cell lines than erlotinib. The combined treatment resulted in synergistic antitumor effects in the Detroit 562 cell line. Immunohistochemical assessment of pharmacodynamic effects in fine-needle aspiration (FNA) biopsies early after treatment using phospho MAPK, Phospho-P70 and Ki67 as end points demonstrated pathway abrogation in the Detroit 562 tumours treated with the combination, the only group where regressions were seen. In conclusion, an mTOR inhibitor showed antitumor activity in EGFR-resistant SCC cell lines. Marked antitumor effects were associated with dual pathway inhibition, which were detected by early FNA biopsies.

Subthalamic nucleus stimulation modulates afferent inhibition in Parkinson disease

BACKGROUND

Peripheral sensory stimulation at the wrist inhibits the motor cortex as measured by transcranial magnetic stimulation at interstimulus intervals of approximately 20 ms (short latency afferent inhibition [SAI]) and 200 ms (long latency afferent inhibition [LAI]). Previous studies suggested that reduced SAI in Parkinson disease (PD) reflects adverse effect of dopaminergic medications and reduced LAI may be related to nondopaminergic manifestations of PD. We hypothesize that subthalamic nucleus (STN) deep brain stimulation (DBS) may correct these deficiencies.

METHODS

We studied the effects of STN DBS on SAI and LAI in seven PD patients and age-matched controls. PD patients were studied in an off medication followed by an on medication session, with the stimulator switched on or off in random order in each session.

RESULTS

In the on medication session, SAI was reduced in the stimulator off condition and was restored by STN DBS. LAI was partially normalized by STN DBS in the medication on condition.

CONCLUSIONS

Subthalamic nucleus (STN) stimulation improves short latency afferent inhibition, suggesting that it could normalize pathways that are adversely affected by dopaminergic medications. The effect of STN stimulation on long latency afferent inhibition suggests that it may influence nondopaminergic pathways involved in sensorimotor integration.

Trophoblast?Macrophage Interactions: a Regulatory Network for the Protection of Pregnancy

PROBLEM

Macrophages are one of the first immune cells observed at the implantation site. Their presence has been explained as the result of an immune response toward paternal antigens. The mechanisms regulating monocyte migration and differentiation at the implantation site are largely unknown. In the present study, we demonstrate that trophoblast cells regulate monocyte migration and differentiation. We propose that trophoblast cells 'educate' monocytes/macrophages to create an adequate environment that promote trophoblast survival.

METHOD OF STUDY

CD14(+) monocytes were isolated from peripheral blood using magnetic beads. Co-culture experiments were conducted using a two-chamber system. Monocytes were stimulated with lipopolysaccharide (LPS) and cytokine levels were determined using multiplex cytokine detecting assay.

RESULTS

Trophoblast cells increase monocyte migration and induce a significant increase in the secretion and production of the pro-inflammatory cytokines [interleukin-6 (IL-6), IL-8, tumor necrosis factor-alpha] and chemokines (growth-related oncogen-alpha, monocyte chemoattractant protein-1, macrophage inflammatory protein-1beta, RANTES). Furthermore, the response of monocytes to LPS was different in monocytes pre-exposed to trophoblast cells.

CONCLUSION

The results of this study suggest that trophoblast cells are able to recruit and successfully educate monocytes to produce and secrete a pro-inflammatory cytokine and chemokine profile supporting its growth and survival. Furthermore we demonstrate that trophoblast cells can modulate monocytes response to bacterial stimuli.

Effect of over-expression of neuropathy target esterase on mammalian cell proliferation

Neuropathy target esterase (NTE), the human homologue of a protein required for brain development in Drosophila, is expressed primarily in neural cells but is also detected in non-neural cells. Although NTE has been proposed to play a role in neurite outgrowth and process elongation during neurodifferentiation, the function of NTE has not been defined in neural cells. In this study we have investigated the possible role of NTE in neuroblastoma cells and non-neural cells using an over-expression strategy. Over-expression of NTE in human neuroblastoma SH-SY5Y cells and monkey kidney COS7 cells led to an accumulation of NTE on the cytoplasmic surface of the endoplasmic reticulum and inhibition of cell proliferation. In particular, high levels of NTE arrested COS7 cells at G2/M stage yet was not associated with arrest at a particular phase of the cell cycle in SH-SY5Y cells. Moreover, over-expression of NTE did not induce apoptosis in two kinds of cell lines as assessed by flow cytometry. These results suggest that the role of NTE over-expression in cell proliferation is associated with different mechanisms in different cells.

Depot-specific messenger RNA expression of 11β-hydroxysteroid dehydrogenase type 1 and leptin in adipose tissue of children and adults

OBJECTIVE

To compare expression of messenger RNA (mRNA) coding for the cortisol regenerating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), and the adipocytokines leptin and resistin in paired biopsies of subcutaneous adipose tissue (SC) and omental adipose tissue (OM) from children.

DESIGN

Paired biopsies (SC and OM) were obtained from 54 children (age 0.17-16 years, body mass index (BMI) 12.5-28.3 kg/m(2), BMI standard deviation score (SDS) -2.5-4.5) and 16 adults (age 27-79 years, BMI 19-46 kg/m(2)) undergoing open abdominal surgery. mRNA levels of 11beta-HSD1, leptin and resistin were measured using quantitative real-time polymerase chain reaction (PCR).

RESULTS

11beta-HSD1 mRNA level was higher in OM than in SC (P<0.05), whereas leptin mRNA was higher in SC than in OM (P<0.001). There was no difference in the resistin mRNA level between SC and OM. These results were consistent in children and adults. In children, 11beta-HSD1 mRNA in SC was positively associated with BMI SDS (P<0.05), whereas in OM it was positively associated with age (P<0.05). The association between 11beta-HSD1 expression and age remained significant after adjustment for BMI SDS and gender. Leptin mRNA was positively associated with BMI SDS (SC: P<0.001, OM: P<0.001) but not with age in children. In multiple regression analyses, including anthropometric variables and age, BMI SDS was independently associated with mRNA levels of 11beta-HSD1 (P<0.05) and leptin (P<0.001) in SC. When normal weight and overweight children were analyzed separately, 11beta-HSD1 mRNA levels were positively associated with leptin in OM in the overweight group (P<0.05).

CONCLUSION

There are depot-specific differences in mRNA levels of 11beta-HSD1 and leptin in children and adults. The positive association of 11beta-HSD1 mRNA in OM with age may reflect a causal role in visceral fat accumulation during growth. Increasing 11beta-HSD1 and leptin mRNA in SC with increasing BMI SDS could suggest that the risk of metabolic consequences of obesity may be established early in life.

Reduced semen quality in chronic prostatitis patients that induce the release of apoptotic protein Omi/HtrA2 from spermatozoa

The relationship between chronic prostatitis and fertility has been disputed for many years. Several groups have shown infection and autoimmune response against prostate antigens could have a deleterious effect on semen quality and fertility. This study was conducted to test the hypothesis that Omi/HtrA2-induced apoptosis in chronic prostatitis could be a mechanism underlying the observed clinical benefit. The Omi/HtrA2 serine protease is a nuclear-encoded mitochondrial protein, which can be released from mitochondria into the cytosol after apoptosis stimuli, inducing apoptosis in caspase-dependent and independent manners. Forty-one patients diagnosed as suffering from chronic prostatitis were included. Healthy normal individuals were included as controls. Human spermatozoa in the semen were purified by Percoll-gradient technique to separate the seminal plasma and other round cells. Measurements for sperm concentration, motility, morphology, proinflammatory cytokines, Omi/HtrA2 mRNA and protein levels in spermatozoa of chronic protatitis patients, were performed accordingly. Significantly increased levels of proinflammatory cytokines were detected in seminal plasma from these prostatitis patients. Omi/HtrA2 mRNA and protein levels were significantly higher in prostatitis men than in normal men. This study shows that chronic prostatitis patients present important alterations in their semen quality parameters, Omi/HtrA2 mRNA and protein levels of spermatozoa. We speculate that the inflammatory process involved may affect male fertility by release of proapoptotic protein Omi/HtrA2.