Liquid biopsy assay for lung carcinoma using centrifuged supernatants from fine-needle aspiration specimens

INTRODUCTION

Tumor mutation profiling is standard-of-care in lung carcinoma patients. However, comprehensive molecular profiling of small specimens, including core needle biopsy (CNB) and fine-needle aspiration (FNA) specimens, may often be inadequate due to limited tissue. Centrifuged FNA supernatants, which are typically discarded, have emerged recently as a novel liquid-based biopsy for molecular testing. In this study, we evaluate the use of lung carcinoma FNA supernatants for detecting clinically relevant mutations.

METHODS

Supernatants from lung carcinoma FNA samples (n = 150) were evaluated. Samples were further analyzed using next-generation sequencing (NGS) and ultrasensitive droplet digital PCR (ddPCR). Mutation profiles in a subset of samples were compared with results derived from paired tissue samples from the same patient (n = 67) and available plasma liquid biopsy assay (n = 45).

RESULTS

All 150 samples yielded adequate DNA and NGS were carried out successfully on 104 (90%) of 116 selected samples. Somatic mutations were detected in 82% of the samples and in 50% of these patients a clinically relevant mutation was identified that would qualify them for targeted therapy or a clinical trial. There was high overall concordance between the mutation profiles of supernatants and the corresponding tissue samples, with 100% concordance with concurrent FNA and 96% with concurrent CNB samples. Comparison of actionable driver mutations detected in supernatant versus plasma samples showed 84% concordance.

CONCLUSIONS

FNA supernatants can provide a valuable specimen source for genotyping lung carcinoma especially in patients with insufficient tumor tissue, thereby reducing multigene mutation profiling failure rates, improving turnaround times, and avoiding repeat biopsies.

Suppressed immune microenvironment and repertoire in brain metastases from patients with resected non-small-cell lung cancer

BACKGROUND

The tumor immune microenvironment (TIME) of lung cancer brain metastasis is largely unexplored. We carried out immune profiling and sequencing analysis of paired resected primary tumors and brain metastases of non-small-cell lung carcinoma (NSCLC).

PATIENTS AND METHODS

TIME profiling of archival formalin-fixed and paraffin-embedded specimens of paired primary tumors and brain metastases from 39 patients with surgically resected NSCLCs was carried out using a 770 immune gene expression panel and by T-cell receptor beta repertoire (TCRβ) sequencing. Immunohistochemistry was carried out for validation. Targeted sequencing was carried out to catalog hot spot mutations in cancer genes.

RESULTS

Somatic hot spot mutations were mostly shared between both tumor sites (28/39 patients; 71%). We identified 161 differentially expressed genes, indicating inhibition of dendritic cell maturation, Th1, and leukocyte extravasation signaling pathways, in brain metastases compared with primary tumors (P < 0.01). The proinflammatory cell adhesion molecule vascular cell adhesion protein 1 was significantly suppressed in brain metastases compared with primary tumors. Brain metastases exhibited lower T cell and elevated macrophage infiltration compared with primary tumors (P < 0.001). T-cell clones were expanded in 64% of brain metastases compared with their corresponding primary tumors. Furthermore, while TCR repertoires were largely shared between paired brain metastases and primary tumors, T-cell densities were sparse in the metastases.

CONCLUSION

We present findings that suggest that the TIME in brain metastases from NSCLC is immunosuppressed and comprises immune phenotypes (e.g. immunosuppressive tumor-associated macrophages) that may help guide immunotherapeutic strategies for NSCLC brain metastases.

An insight into current concepts and techniques in resin bonding to high strength ceramics

BACKGROUND

Reliable bonding between high strength ceramics and resin composite cement is difficult to achieve because of their chemical inertness and lack of silica content. The aim of this review was to assess the current literature describing methods for resin bonding to ceramics with high flexural strength such as glass-infiltrated alumina and zirconia, densely sintered alumina and yttria-partially stabilized tetragonal zirconia polycrystalline ceramic (Y-TZP) with respect to bond strength and bond durability.

METHODS

Suitable peer reviewed publications in the English language were identified through searches performed in PubMed, Google Search and handsearches. The keywords or phrases used were 'resin-ceramic bond', 'silane coupling agents', 'air particle abrasion', 'zirconia ceramic' and 'resin composite cements'. Studies from January 1989 to June 2015 were included.

RESULTS

The literature demonstrated that there are multiple techniques available for surface treatments but bond strength testing under different investigations have produced conflicting results.

CONCLUSIONS

Within the scope of this review, there is no evidence to support a universal technique of ceramic surface treatment for adhesive cementation. A combination of chemical and mechanical treatments might be the recommended solution. The hydrolytic stability of the resin ceramic bond should be enhanced.

Multiplex KRASG12/G13 mutation testing of unamplified cell-free DNA from the plasma of patients with advanced cancers using droplet digital polymerase chain reaction

Background

Cell-free DNA (cfDNA) from plasma offers easily obtainable material for KRAS mutation analysis. Novel, multiplex, and accurate diagnostic systems using small amounts of DNA are needed to further the use of plasma cfDNA testing in personalized therapy.

Patients and methods

Samples of 16 ng of unamplified plasma cfDNA from 121 patients with diverse progressing advanced cancers were tested with a KRASG12/G13 multiplex assay to detect the seven most common mutations in the hotspot of exon 2 using droplet digital polymerase chain reaction (ddPCR). The results were retrospectively compared to mutation analysis of archival primary or metastatic tumor tissue obtained at different points of clinical care.

Results

Eighty-eight patients (73%) had KRASG12/G13 mutations in archival tumor specimens collected on average 18.5 months before plasma analysis, and 78 patients (64%) had KRASG12/G13 mutations in plasma cfDNA samples. The two methods had initial overall agreement in 103 (85%) patients (kappa, 0.66; ddPCR sensitivity, 84%; ddPCR specificity, 88%). Of the 18 discordant cases, 12 (67%) were resolved by increasing the amount of cfDNA, using mutation-specific probes, or re-testing the tumor tissue, yielding overall agreement in 115 patients (95%; kappa 0.87; ddPCR sensitivity, 96%; ddPCR specificity, 94%). The presence of ≥ 6.2% of KRASG12/G13 cfDNA in the wild-type background was associated with shorter survival (P = 0.001).

Conclusion(s)

Multiplex detection of KRASG12/G13 mutations in a small amount of unamplified plasma cfDNA using ddPCR has good sensitivity and specificity and good concordance with conventional clinical mutation testing of archival specimens. A higher percentage of mutant KRASG12/G13 in cfDNA corresponded with shorter survival.

Pediatric Ventriculoperitoneal Shunts and their Complications: An Analysis

Introduction:

Ventriculoperitoneal (VP) shunt is the most commonly utilized shunting procedure because of the capacity of the peritoneum to resorb fluid. Initial and subsequent peritoneal catheter placements can be done with relative ease. They are associated with a variety of complications.

Materials and Methods:

The total number of patients operated in the study period was 96. We studied 41 operated patients of VP shunt who had various shunt-related complications and analyzed the predisposing risk factors and spectrum of complications.

Results:

The mean age was 28 ± 32 months out of which 28 were males and 13 females. The etiology of hydrocephalus was aqueductal stenosis in 18, Arnold Chiari malformation in 10, Dandy–Walker malformation in 2, postmeningitis in 8 (pyogenic in 5 and tubercular in 3), postintraventricular hemorrhage in 2 patients and postencephalocele surgery in 1.

Conclusion:

With this retrospective review of complications of VP shunts, age at initial shunt insertion and the interval between the age of initial shunt placement and onset of complications were the most important patient-related predictors of shunt failure. The different predominant etiological factors responsible for early and late shunt failure were infective and mechanical complications, respectively.

Clinicopathologic characteristics and gene expression analyses of non-KRAS 12/13, RAS-mutated metastatic colorectal cancer

BACKGROUND

KRAS mutations in codons 12 and 13 are present in ∼40% of all colorectal cancers (CRC). Activating mutations in codons 61 and 146 of KRAS and in codons 12, 13, and 61 of NRAS also occur but are less frequent. The clinicopathologic features and gene expression profiles of this latter subpopulation of RAS-mutant colorectal tumors have not yet been clearly defined but in general are treated similarly to those with KRAS 12 or 13 mutations.

PATIENTS AND METHODS

Records of patients with metastatic CRC (mCRC) treated at MD Anderson Cancer Center between December 2000 and August 2012 were reviewed for RAS (KRAS or NRAS) and BRAF mutation status, clinical characteristics, and survival outcomes. To study further with an independent cohort, data from The Cancer Genome Atlas were analyzed to define a gene expression signature for patients whose tumors feature these atypical RAS mutations and explore differences with KRAS 12/13-mutated colorectal tumors.

RESULTS

Among the 484 patients reviewed, KRAS 12/13, KRAS 61/146, NRAS, and BRAF mutations were detected in 47.7%, 3.0%, 4.1%, and 7.4%, respectively, of patients who were tested for each of these aberrations. Lung metastases were more common in both the KRAS 12/13-mutated and atypical RAS-mutated cohorts relative to patients with RAS/BRAF wild-type tumors. Gene expression analyses revealed similar patterns regardless of the site of RAS mutation, and in silico functional algorithms predicted that KRAS and NRAS mutations in codons 12, 13, 61, and 146 alter the protein function and drive tumorgenesis.

CONCLUSIONS

Clinicopathologic characteristics, survival outcomes, functional impact, and gene expression profiling were similar between patients with KRAS 12/13 and those with NRAS or KRAS 61/146-mutated mCRC. These clinical and bioinformatic findings support the notion that colorectal tumors driven by these RAS mutations are phenotypically similar.

Abstract P1-02-05: Identification of HER-2/neu amplification using amplicon based benchtop next generation sequencing

Introduction

Aplicon based next generation sequencing (NGS) assays have the potential to incorporate simultaneous assessment of somatic mutations and copy number variation into a single platform. Although not specifically designed for this purpose, we noted numerous examples of apparent HER-2/neu gene amplification in analyzing results from our mutation profiling 46-gene cancer NGS panel (Life Technologies, South San Francisco, CA).

Material and Methods

Existing amplicon coverage data from the TorrentSuite 2.0 (Life Technologies) pipeline was accessed and used to generate a HER-2/neu coverage proportion (ratio between all HER-2/neu amplicon reads and all other amplicon reads). This ratio was calculated for 170 unique cases of breast carcinoma. A total of 4 cases were eliminated from analysis due to indeterminate IHC/FISH results. Using a total of 166 cases, we performed ROC curve analysis to determine the sensitivity and specificity of NGS based HER-2/neu amplification compared to that of traditional IHC and FISH testing (MedCalc v8.0).

Results

The NGS based HER-2/neu coverage proportions in the 166 cases showed a clearly non-normal distribution with an outlier cluster of cases with an elevated NGS HER-2/neu ratio (6 cases with ratios &gt;0.045). The distribution of NGS based HER-2/neu ratios for the entire population ranged from 0.01 to a maximum of 0.34. ROC curve analysis of NGS HER-2/neu proportions compared to IHC/FISH data showed a maximal sensitivity of 75.0% and specificity of 100% at an NGS ratio cut off of ≥0.045.

In the 166 cases, 6 showed a HER-2/neu coverage proportion of &gt; 0.045 (range 0.045-0.34). Utilizing the 0.045 NGS ratio cut off value, the population frequency of cases positive for HER2 expression was 3.4%. Of the 160 samples with NGS coverage proportion &lt; 0.045, only two cases were positive by IHC/FISH testing.

The correlation between NGS HER-2/neu coverage proportion and IHC/FISH testing was highly significant (Spearman rank correlation r = 0.67, p &lt; 0.0001 CI: 0.58-0.75).

Conclusions

Even utilizing a limited somatic cancer panel that includes less than 200 amplicons in 46 genes, clinically significant HER-2/neu amplification can be readily identified. This is the first study to describe the functional utility of HER-2/neu amplification detection using a NGS based amplicon assay. This study shows that in addition to mutation analysis, amplification data can be simultaneously obtained, which has striking implications for potential clinical utility and HER-2/neu amplification detection outside of traditional IHC and HER2 testing modalities. Furthermore, utilizing this assay as a primary screening modality could limit the additional expense of multiple single gene testing.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-02-05.

Abstract P1-06-07: Immune-induced epithelial to mesenchymal transition in inflammatory breast cancer induces unique increases in E-cadherin, adhesion and migration through TNF-a, IL-6 and TGF-b

BACKGROUND AND RATIONALE

Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer and patients frequently present with metastases at the time of their diagnosis. Although a robust IBC-specific molecular signature remains elusive, the disease is frequently characterized by persistent expression of the adhesion molecule, E-cadherin. This is highly counterintuitive as epithelial to mesenchymal transition (EMT), frequently associated with metastasis, results in decreased E-cadherin expression and highly aggressive cancers frequently express low levels of E-cadherin.

We hypothesized that persistent inflammation, mediated by immune activation, increases the plasticity of IBC cells, inducing EMT and allowing the re-acquisition of epithelia characteristics once removed from the inflammatory foci. In support of this hypothesis, previous in vitro work showed that soluble factors from activated immune cells induce EMT-related transcripts in both IBC and non-IBC cell lines. However, uniquely in 3 of 4 IBC cell lines but none of the non-IBC cell lines, this program included an increase of E-cadherin expression.

RESULTS

We used real-time cell analysis (RTCA) from Acea Biosciences (San Diego, CA) to probe the effect of immune conditioned media, produced by stimulating healthy donor peripheral blood mononuclear cells through the T-cell receptor or through toll-like receptor-4, on SUM149 inflammatory breast cancer cells. Consistent with the increased expression of E-cadherin, we observed rapid and strong increases in cellular adhesion as measured by the RCTA cell-index following culture with immune inflammatory factors. However, using the CIM chip, the same cells also showed strong increases in invasion and migration.

To determine the inflammatory factors involved in this process, we screened the immune conditioned media using a Luminex array (Millipore, Billerica, MA). TGF-b, TNF-α, and IL-6, previously shown to induce EMT, were all found at elevated levels. In 5 culture supernatants of healthy donor PBMC activated for 48h with anti-CD3 antibody, TGF-β had a modest 1.6-fold increase; TNF-α had an average 101-fold increase; while IL-6 had an average 347-fold increase. When added to cultures of SUM149 cells, these factors recapitulated the EMT gene expression signature in SUM149 including the increase in E-cadherin expression. Furthermore, the addition of neutralizing antibodies against TNF-α, TGF-β, and IL-6 to immune conditioned media prior to exposure to SUM149 cells resulted in less EMT.

CONCLUSIONS

Inflammatory factors may induce both the migratory ability and the characteristic persistent E-cadherin expression of IBC cells. This is mediated in part by TNF-α, TGF-β, and IL-6. However, the molecular basis for this unique IBC response requires further study hindering the development of optimal therapies. Ongoing studies at MD Anderson are exploring both the tumor and stromal components of inflammatory breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-06-07.

Abstract P5-04-06: Soluble factors from activated immune cells induce epithelial mesenchymal transition in inflammatory breast cancer cells

Rationale: Inflammatory breast cancer (IBC) is the most insidious form of locally advanced disease. Emerging evidence suggests that host factors in the microenviromement may interact with underlying IBC genetics to promote the aggressive nature of the tumor. An integral part of the metastatic process involves epithelial to mesenchymal transition (EMT) where primary breast cancer cells gain motility and stem cell features that allow distant seeding. Interestingly, the IBC consortium microarray data found no clear evidence for EMT in IBC tumor tissues. However, it is unknown if soluble factors secreted by activated immune cells mediate EMT in the IBC microenvironment that may account for the absence of EMT in studies of the tumor cells themselves. Therefore, we tested whether the conditioned media of activated immune cells were capable of inducing EMT in IBC cells.

Methods: Conditioned media (CM) were generated using healthy donor peripheral blood mononuclear cells that were activated with anti-CD3 antibody immobilized to plastic and soluble anti-CD28 antibody to activate T cells through the T-cell receptor (TCR) or left unstimulated for 48 hours. Thereafter, CM from each of the cultures was harvested and filtered. Next, 48-hour pre-seeded SUM149 IBC cells were grown in culture medium consisting of 25% CM and 75% IBC culture medium for an additional 2 days. Unconditioned media and TGF-β were used as negative and positive controls, respectively for EMT. Following treatment with CM, RNA was extracted from the target cells and analyzed for the presence of EMT-related transcription factors (EMT-TF) and markers of epithelial and mesenchymal states by TaqMan® qRT-PCR. Subsequently, a panel of 24 genes was tested on 4 IBC cell lines (SUM149, SUM190, KPL4 and IBC-3) and 5 non-IBC cell lines (MCF-10a, MCF-7, MDA-231, and MDA-453) treated with immune-activated CM using the Fluidigm® Dynamic Array integrated fluidic circuit (“chip”) gene expression platform which allows for the simultaneous quantification of 2,304 data points using TaqMan® assays. Formalin-fixed, paraffin embedded blocks were prepared from trypsinized cells for immunohistochemical (IHC) staining to detect E-cadherin and vimentin expression.

Results: SUM149 cells cultured in the presence of TCR-activated CM for two days showed upregulation in EMT-TFs (SNAIL1, ZEB1, and TG2), vimentin and fibronectin by qRT-PCR. IHC staining showed increases in both vimentin and E-cadherin expression after 48-hour exposure to anti-TCR CM. Fluidigm® gene expression analysis of multiple cell lines exposed to anti-TCR CM showed that E-cadherin expression was unchanged or slightly decreased in non-IBC cell lines, whereas 3 of 4 IBC cell lines showed an increase in E-cadherin.

Discussion: These data suggest that soluble factors secreted by activated immune cells are capable of inducing EMT in IBC cells and may mediate the persistent E-cadherin expression observed in IBC. Such processes may contribute to the highly aggressive nature of the disease; however, an immune competent in vivo model is warranted to fully understand the implications of these findings.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-06.

PD09-01: Target-Based Therapeutic Matching in Early-Phase Clinical Trials in Patients with Advanced Breast Cancer and PIK3CA Mutations

Background: Therapeutic matching based on underlying molecular abnormalities showed promising results in early-phase clinical trials. PIK3CA mutations may predict response to therapies with PI3K/AKT/mTOR inhibitors.

Methods: Tumors from patients with breast cancer referred to the Clinical Center for Targeted Therapy (Phase I Program) were analyzed for PIK3CA mutations. Patients with PIK3CA mutations were treated, whenever feasible, with agents targeting the PI3K/AKT/mTOR pathway.

Results: Of 54 patients analyzed, 15 (28%) had PIK3CA mutations. PIK3CA mutations were found in 5/9 (56%) metaplastic, 3/8 (38%) HER2−positive, 7/29 (24%) hormone receptor-positive, and 0/8 (0%) triple negative (excluding metaplastic) breast cancers (P=0.07). Of the 15 patients with PIK3CA mutations, 12 (80%) were treated in clinical trials containing a PI3K/AKT/mTOR pathway inhibitor (median age, 54; median number of prior therapies, 3). Of these 12 patients, 3 (25%, 95% CI 0.09−0.53) had stable disease for more than 6 months (SD≥6 months; n=1) or a partial response (PR; n=2). Breast cancer patients without PIK3CA mutations treated on the same protocols had a rate of SD≥6 months/PR of 8% (1/12; 95% CI 0.01−0.35, p=0.6). Of the 4 patients with a H1047R mutation treated with agents targeting the PI3K/AKT/mTOR pathway, 3 (75%) had SD≥6 months (n=1) or a PR (n=2) compared to 0 of 8 patients (0%) with other PIK3CA mutations (P=0.045). Patients with H1047R mutations had a median progression-free survival (PFS) of 8.5 months compared to 2 months in patients with other PIK3CA mutations (p=0.13).

Conclusion: Heavily pretreated patients with PIK3CA-mutant advanced breast cancer had a SD≥6 months/PR rate of 25% on protocols incorporating PI3K/AKT/mTOR. Patients with mutation H1047R had significantly longer SD≥6 months/PR rate compared to those with other PIK3CA mutations. Our observations suggest that screening for PIK3CA mutations is warranted in larger numbers of patients with advanced breast cancer when treatment with PI3K/AKT/mTOR pathway inhibitors is planned.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD09-01.

Personalized medicine in a phase I clinical trials program: The M. D. Anderson Cancer Center Initiative

CRA2500

Background: We initiated a personalized medicine program hypothesizing that tumor molecular analysis and use of targeted therapy to counteract the effects of specific aberrations would improve the outcomes of affected patients. Methods: Molecular analysis was performed in the M. D. Anderson CLIA-certified pathology laboratory. Patients whose tumors had an aberration were treated in the Phase I Program with a matched targeted agent, when available. Results: Tumor molecular analysis was feasible in 852 (89%) of 955 consecutive patients with advanced cancer. Of 852 patients (median, age 56 yrs; prior therapies 4), 354 (41.5%) had ≥ 1 aberration: 10% of patients had a PIK3CA mutation; 19% KRAS; 8% NRAS; 19% BRAF; 3% EGFR; and 2% had a CKIT mutation; 21% had PTEN loss. Results are shown in the table. Median time to treatment failure (TTF) in 161 patients with 1 aberration treated with matched targeted therapy was 5.3 months (95%CI: 4.1, 6.6) vs 3.2 months (95%CI: 2.9 – 4.0) for their prior systemic antitumor therapy (prior to referral to phase I) (p= .0003). For patients with 1 aberration, the CR+PR rate was 29% with matched targeted therapy vs. 8% without matching (p = .0001). The CR+PR rate was 6% in 438 patients without molecular testing treated on the same studies. Conclusions: Preliminary results suggest that in early clinical trials matching patients with targeted drugs based on their molecular profile results in (a) longer TTF compared to their prior therapy and (b) higher rates of response, survival and TTF compared to those seen in patients treated without molecular matching. Support: 3UL1 RR024148 04 S1 and IPCT.

[Table: see text]

A nine-gene predictor of therapy response in adult Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+ ALL)

7014

Background: Ph+ ALL in adults shows a poor response to therapy and high frequency of relapse. This study utilized a meta-analysis of previous genome-wide gene expression studies to define and validate a nine-gene predictor of outcome in Ph+ ALL patients. Methods: Normalized gene expression data from previously published studies of 672 ALL patients were analyzed to identify genes associated with therapy response. Expression of the selected genes was assessed using Applied Biosystems low density reverse transcription quantitative PCR (RT-qPCR) arrays in bone marrow (BM) samples from 27 adult Ph+ ALL patients treated with standard chemotherapy plus a tyrosine kinase inhibitor. Therapy responses were defined at the molecular level by monitoring BCR/ABL1 levels, and categorized into 3 groups: optimal, persistent and relapse. Median follow up was 6 months (range 4–15). Median disease-free survival among the optimal and relapse groups were 12 and 5 months respectively (p = 0.002). There was no statistical difference in age, initial peripheral blood white cell and BM blast counts, and initial normalized BCR/ABL1 levels between groups. Differentially expressed genes were selected using the significance analysis of microarrays (SAM). Hierarchical clustering and principal component analysis were applied to assess the correlation between gene expression pattern and therapy response. A predictive model was built using support vector machines. Differences in survival among groups were compared by Kaplan-Meier analysis. Results: Data mining and pathway analysis of the published data identified 46 genes in 7 pathways potentially associated with therapy response (p < 0.001). RT-qPCR results from a 15 case training set, 5 in each outcome group, identified 9 genes that classified the cases with 100% accuracy. Validation using an additional 12 cases showed 91.7% prediction accuracy (ROC error = 0.056). Compared with the initial diagnostic samples, gene expression pattern in relapsed samples shifted to that resembling the persistent group. Conclusions: Using data-trimming of whole genome expression studies, we defined and validated a nine-gene signature that is an independent predictive marker for therapy response in adult Ph+ ALL patients.

No significant financial relationships to disclose.

MYC translocation in chronic lymphocytic leukaemia is associated with increased prolymphocytes and a poor prognosis

Chromosomal translocations that involve MYC, characteristic of Burkitt lymphoma, are rare in chronic lymphocytic leukaemia (CLL). We report the clinical, morphological, immunophenotypic, cytogenetic and molecular genetic features of eight CLL cases with MYC rearrangement. The patients, five men and three women (median age, 71 years) had bone marrow involvement and an absolute peripheral blood lymphocytosis; five had lymphadenopathy; seven had splenomegaly. Prolymphocytes were increased (>/=10%) in all cases. Six cases were classified as CLL with increased prolymphocytes (CLL/PL; prolymphocytes 10-55%), and two were classified as CLL in prolymphocytic transformation (CLL/PT; prolymphocytes >55%). All cases co-expressed CD5, CD19, and CD23; five of eight expressed ZAP-70. Of seven cases tested, four had mutated and three had unmutated IGHV genes. Conventional cytogenetic studies demonstrated t(8;14)(q24.1;q32) in five cases, t(8;22)(q24.1;q11) in two cases, and t(2;8)(p12;q24.1) in one case. Seven cases contained additional chromosomal abnormalities. All patients received combination chemotherapy. Two developed Epstein-Barr virus (EBV)-associated diffuse large B-cell lymphomas (DLBCL) that were clonally unrelated to the CLL. At follow-up, two patients are alive, four died of underlying disease, one died of EBV-associated DLBCL, and one died of an unrelated cancer. In summary, MYC rearrangement, which occurs rarely in CLL patients, is associated with increased prolymphocytes, complex cytogenetic abnormalities, and a poor prognosis.

Frequency and clinical significance of BCR-ABL mutations in patients with chronic myeloid leukemia treated with imatinib mesylate

Mutations of the BCR-ABL kinase domain are a common mechanism of resistance to imatinib in chronic myeloid leukemia. We screened for mutations 171 patients failing imatinib therapy. Sixty-six mutations in 23 amino acids were identified in 62 (36%) patients not responding to imatinib. Phosphate-binding loop (P-loop) mutations were the most frequent (n=24; 36%). By multivariate analysis, factors associated with development of mutations were older age (P=0.026) prior interferon therapy (P=0.026), and accelerated phase or blast phase at time of imatinib failure (P=0.001). After a median follow-up of 38 months (range, 4-68 months) from the start of imatinib therapy, seven patients with non-P-loop and two with P-loop mutation died. By multivariate analysis, development of clonal evolution and higher percentage of peripheral blood basophils were associated with worse survival from the time of imatinib failure. Mutation status had no impact on survival. When survival was measured from the time therapy started, non-P-loop mutations together with duration of response and transformation at the time of failure to imatinib were associated with shorter survival. In conclusion, P-loop mutations were not associated with poor outcome, suggesting that the prognosis of patients who fail imatinib is multifactorial.

High-dose imatinib mesylate treatment in patients (Pts) with untreated early chronic phase (CP) chronic myeloid leukemia (CML): 2.5-year follow-up

6535

Background: The standard dose (SD) of imatinib for CP CML is currently 400 mg daily, but higher doses (HD) may be more effective. We conducted 2 consecutive trials using HD imatinib (i.e., 400mg twice daily) in previously untreated early CP CML pts. This is an updated analysis of the longer follow-up. Methods: A total of 175 previously untreated pts received HD imatinib. We compared the results with a previous study using SD imatinib (400mg/day) in untreated pts with early CP CML (N=50). Results: Cytogenetic and molecular responses were evaluable in 222 pts (N=49 at SD, 173 at HD) and 217 pts (N=46 at SD, 171 at HD), respectively. In HD group, Sokal risk classification was good in 69%, intermediate in 29%, and poor in 11% of pts. There were no differences in pre-treatment characteristics between two groups. The median age was 48 years in both groups. Median follow-up is 53 months for SD and 30 months for HD group. Patients treated with HD had a higher rate of complete cytogenetic responses (90% vs 78% with SD, p=0.03) and these occurred earlier, with 69% achieving this response after 6 months of therapy vs 45% with SD (p=0.001). The cumulative incidence of major molecular response was significantly better in HD group (p=0.03), and this response was also observed earlier in HD group: at 12 months 54% in HD and 24% in SD group had achieved this response (p=0.001). At 24 months, 19/70 (27%) evaluable pts with HD versus 3/31 (10%) of pts in SD group achieved complete molecular remission. Four pts (2%) in HD group and 4 pts (8%) in SD group have progressed to advanced phases (p=0.05). There was a trend in favor of the HD group for transformation-free-survival but it was not statistically significant (p=0.07). Overall survival is excellent in both groups (24 month survival, 99% with HD vs 98% with SD; p=0.24). Grade 3 or 4 hematologic toxicity was more frequent in HD group whereas extramedullary toxicity was similar in two groups. The median actual dose in HD group was 800 mg at 12 months, with 39% patients requiring dose reduction at some point. Conclusions: High-dose imatinib provides higher rates of complete cytogenetic responses and earlier molecular responses with some increase myelosupression. The long-term benefit of earlier responses remains to be demonstrated.

[Table: see text]

Dynamics of molecular response to dasatinib (BMS-354825) in patients (pts) with chronic myelogenous leukemia (CML) resistant or intolerant to imatinib

6525

Background: Mutations in the BCR-ABL kinase domain are a common mechanism (40%) of imatinib-resistance. Dasatinib is 300-fold more potent than imatinib against Abl and has activity against all BCR-ABL mutants, except T315I. We investigated the molecular response to dasatinib in pts with CML intolerant or resistant to imatinib. Methods: Fifty-three pts in chronic (CP) (n=29), accelerated (AP) (n=14) and blast (BP) (n=10) phase CML received dasatinib for a median of 22 wks (range, 7 to 42). Pts had received a median of 4 therapies (range, 1 to 8) including imatinib (n=53), IFN (n=32), and AMN107 (n=9). Imatinib was stopped (41 resistant and 12 intolerant) after a median of 34 mo (range, 2.5 to 82). Quantitative reverse transcription PCR in peripheral blood samples was performed prior to dasatinib and every 3 mo thereafter. Median BCR-ABL/ABL ratio (%) at dasatinib start was 78.34 (range, 0.009 to 100). Twenty-four of 42 assessed pts harbored 16 different BCR-ABL mutants. The most common mutations were H396R (n=5), G250E (n=4), and M351T (n=3). Results: BCR-ABL reductions occurred in 48 (90%) pts: <1-log in 12 (23%) pts (7 CP, 2 AP, 3 BP) after a median of 12 wks (range, 4 to 38); >1-log in 15 (28%) pts (5 CP, 6 AP, 4 BP) after a median of 12 wks (range, 4 to 35); >2-logs in 10 (19%) pts (7 CP, 2 AP, 1 BP) after a median of 14.5 wks (range, 4 to 36) and >3-logs in 9 (17%) pts (5CP, 3 AP, 1 BP) after a median of 16 wks (range, 4 to 36). BCR-ABL/ABL ratio <0.05 was seen in 5 (9.5%) CP pts. After a median follow-up of 26 wks (range, 6 to 41), 12 (23%) pts stopped dasatinib due to death (n=2), disease progression (n=6), BMT (n=1), or intolerance (n=3). Dose reductions (31/53, 58%) were associated with BCR-ABL increments in 13 pts (>1 log in 10). Twenty-nine (55%) pts had at least 1 follow-up PCR analysis after their lowest transcript level, and in 9 pts the BCR-ABL/ABL ratio increased >1 log (F359V, Y253H, S348L, H396P, F317L, G250E, F359C), in 4 pts >2 logs (E255V/K, V299L) and in 2 pts >3 logs (F359V, H396R). T315 mutants have not been detected. Conclusion: Dasatinib is associated with significant molecular responses in imatinib-resistant/intolerant CML across multiple BCR-ABL mutants. Longer follow-up is needed to define the stability and durability of these responses.

[Table: see text]

Transcription factor NFkB a potential molecular marker for predicting and improving treatment efficacy in esophageal cancer

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Background: Esophageal/gastroesophageal junction adenocarcinoma (E/GEJAC) remains one of the most aggressive malignancies. Chemoradiotherapy (CTXRT) followed by surgery has been used for localized E/GEJAC. Patients (pts) achieving pathologic complete response (pathCR) have an improved survival, but ≈70% of pts exhibit at surgery resistant residual, highly aggressive tumors despite CTXRT. There is a need to identify this high-risk population and target molecular pathways associated with cancer resistance. We have shown that nuclear NFκB was associated with poor clinical outcome of E/GEJAC pts undergoing 5FU, Docetaxel and Cisplatinum therapy. To validate our findings, we examined the impact of nuclear NFκB on clinical outcome of pts undergoing diverse CTXRT regimens. Methods: Pre- treatment tumor biopsies and post-treatment resected residual tumors were analyzed from pts receiving neo-adjuvant CT or CTXRT. NFκB protein expression was assessed by immunochemistry and correlated to pathCR and clinical outcome. Tumors were considered NFκB positive (pos) when ≥5% of cells expressed nuclear NFκB. Results: 80 pts, clinically staged II, III and IVA, were studied. All pts received antifolates, and 80%, 65% & 31% received taxanes, topo-1 inhibitors and/or platinum analogues, respectively. Radiation therapy was 50.4 Gy at 1.8 Gy once a day to all pts. 75/80 pts had available pre-treatment biopsies, all 58 pts with <pathCR had available residual tumors. Pre-treatment NFκB was predictive for lack of response to CTXRT [NFκB pos: 2/22 pathCR vs 27/53 <pathCR; P=.006]. In multivariate analysis, including clinical stage, tumor histology, pathCR and lymph nodes metastasis, pre-treatment NFκB was an independent prognostic factor of progression-free (P=.0029, HR=2.90, 95%CI:1.44–5.86) and overall (P=.0073,HR=2.70, 95%CI:1.30–5.60) survivals. NFκB was associated with recurrent disease [pre-treatment NFκB pos 14/29 (48%) vs NFκB negative11/46 (24%), P=.04; pre- or post- NFκB pos 22/47 (47%) vs NFκB neg 4/33 (12%), P=.003]. Conclusions: our data suggest that NFκB defines cancer biology and patterns to therapy response irrespective of the type of chemoradiation used. NFκB may serve as potential molecular target to improve treatment efficacy.

No significant financial relationships to disclose.

Discordant genetic changes in ovarian and endometrial endometrioid carcinomas: a potential pitfall in molecular diagnosis

Endometrioid carcinoma simultaneously involving ovaries as well as the uterine corpus may present a diagnostic dilemma because of the difficulty in determining whether the lesions are separate primary tumors or metastases. It has been reported that the detection of clonality using microsatellite markers may be useful in solving this dilemma. To determine the usefulness of this technique, we compared the genetic alterations in microsatellite markers present in matched pairs of ovarian tumors from 12 patients. The study includes four ovarian cancer FIGO stage I and eight stage III/IV patients, and four patients also with independent endometrial carcinoma of the uterus. DNA from paraffin-embedded tissue was extracted and amplified using a multiplex polymerase chain reaction, after which the status of microsatellite instability and loss of heterozygosity in four microsatellite loci (BAT25, BAT26, D17S250, and D5S346) were determined. In the four patients with stage I ovarian cancer, four microsatellite markers were identical in one patient and three were identical in the remaining three patients. In high-stage patients, three markers were identical in at least 4/8 cases. In three of four patients with uterine involvement, three of the four markers were identical in the uterine tumor and one of the corresponding ovarian tumors. These results suggest that genetic discordance does not indicate independent origin or metastasis of the tumor but instead a progression of genetic changes at separate sites probably due to the marked genetic instability existing in these tumors. Because of these discordant genetic changes, great caution should be taken when distinguishing between primary and metastatic tumors on the basis of microsatellite markers.

Reattachment of fractured fragments of maxillary central incisors--report of a case

Reattachment of the original tooth fragment to the fractured tooth helps in maintaining the tooth's colour, wear resistance, morphology and translucency in the restoration. This paper describes the reattachment of fractured fragments using metallic post and core in case of a 12 year old patients who suffered a complicated facture of maxillary central incisors.

Salt-tolerant mutants in glycophytic salinity response (GSR) genes in Catharanthus roseus

The periwinkle Catharanthus roseus shares glycophytic properties of crop plants. To contribute towards an understanding of the glycophytic response to salinity, large populations of M(2) seeds having an origin in nitroso-methyl urea and ethyl methane sulphonate treatments were screened for germination with 250 mM of NaCl. Out of the nine mutant lines so recovered, which tolerated salt stress due to loss of the normal glycophytic salinity response ( GSR), the characteristics of six gsr mutants are reported here. All six, gsr-1 to gsr-6, differed from the wild-type in both seedling and adult-plant morphological characters beside being salt tolerant. The mutations in them were inherited as monogenic recessive alleles at the corresponding wild-type loci. The trans-complementation tests revealed that the gsr-1 to gsr-6 mutants specified six complementation groups. The mutant seedlings generally accumulated more proline and glycine betaine, constitutively, than the wild-type. The mutant plants transpired lower amounts of water and accumulated higher amounts of proline under drought stress. It was inferred that the products of the six GSR genes defined here are involved in the regulation of salt stress, as well as cell division, developmental and/or morphogenetic pathway(s), in C. roseus.

Frequency and risk factors for pterygium in the Barbados Eye Study

OBJECTIVE

To describe the distribution and risk factors for pterygium in the predominantly black population of the Barbados Eye Study, which was based on a random sample of Barbadian-born citizens between the ages of 40 and 84 years.

METHODS

The standardized protocol included ophthalmic and other measurements, automated perimetry, lens gradings, fundus photography, and a detailed interview. A 10% systematic sample of participants and those meeting specific criteria also received a comprehensive ophthalmologic evaluation.

RESULTS

The Barbados Eye Study included 4709 participants, of whom 2978 were referred for an ophthalmologic evaluation and 2781 (93%) completed the examination. Cases of pterygium were found among 23.4% of 2617 black, 23.7% of 97 mixed (black and white), and 10.2% of 59 white participants examined. In addition to African ancestry, logistic regression analyses indicated a positive association between pterygium and age (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.00-1.02), fewer years of education (OR, 1.43; 95% CI, 1.01-2.03), and an outdoor job location (OR, 1.87; 95% CI, 1.52-2.29). Having a darker skin complexion (OR, 0.66; 95% CI, 0.52-0.83), always using sunglasses outdoors (OR, 0.18; 95% CI, 0.06-0.59), and the use of prescription glasses (OR, 0.75; 95% CI, 0.60-0.93) were protective factors.

CONCLUSIONS

Approximately one quarter of the black participants examined had pterygia, a frequency that was 2.5 to 3 times higher than among whites in the Barbados Eye Study and elsewhere. Pterygium was almost twice as frequent among persons who worked outdoors but was only one fifth as likely among those who always used sunglasses outdoors. Educational interventions to modify these potential exposures may assist in preventing pterygium.

Hepatosplenic gamma/delta T-cell lymphoma in bone marrow. A sinusoidal neoplasm with blastic cytologic features

We report 8 cases of hepatosplenic T-cell lymphoma (HSTCL) involving bone marrow and correlate histologic findings with disease progression. Immunophenotypic analysis demonstrated mature, aberrant gamma/delta T-cell immunophenotypes. Isochromosome 7q was identified in 4 cases; 1 case showed the t(7;14)(q34;q13). Seven of 7 cases tested had monoclonal TCR gamma gene rearrangements. The initial diagnostic bone marrow biopsy specimens were hypercellular with a frequently subtle, predominantly sinusoidal infiltrate of atypical small to medium-sized lymphoid cells. In all cases, aspirate smears at diagnosis and in subsequent specimens contained malignant cells that resembled blasts, some with fine cytoplasmic granules. With progression, the pattern of HSTCL in bone marrow biopsy specimens became increasingly interstitial, and the neoplastic cells became larger. In aspirate smears, the proportion of blasts increased. Seven patients died; 1 was lost to follow-up. Autopsy performed on 1 patient demonstrated malignant cells within vascular channels in all organs sampled, with relatively little tumor formation, resembling intravascular lymphoma at these sites. HSTCL often can be recognized in bone marrow by its unique combination of a sinusoidal pattern in core biopsy specimens and blastic cytology in aspirate smears.

A novel four-color PCR assay to assess T-cell receptor gamma gene rearrangements in lymphoproliferative lesions

We describe a novel 4-color polymerase chain reaction (PCR) assay combined with GeneScan analysis to assess for T-cell receptor gamma chain gene (TCRgamma) rearrangements and evaluate its usefulness in 86 lymphoproliferative lesions. In this assay, each variable region (Vgamma) family primer is 5' end-labeled with a different fluorescent dye, allowing determination of the Vgamma family involved in each TCRgamma rearrangement. PCR products were analyzed by capillary electrophoresis. We detected clonal TCRgamma rearrangements in 60 (98%) of 61 T-cell lymphomas, 2 (15%) of 13 B-cell lymphomas, and 3 (25%) of 12 reactive lesions. These results compared favorably with conventional PCR methods using denaturing gradient gel electrophoresis, which revealed clonal TCRgamma rearrangements in 37 (90%) of 41 T-cell lymphomas, 1 (25%) of 4 B-cell lymphomas, and 2 (25%) of 8 reactive lesions. This 4-color PCR assay is at least equivalent to conventional PCR methods and is convenient, allows accurate size determination of TCRgamma rearrangements, and identifies the specific Vgamma family involved, providing more specific information about TCRgamma rearrangement.

Biotransformation of geranyl acetate to geraniol during palmarosa (Cymbopogon martinii, Roxb. wats. var. motia) inflorescence development

Only immature palmarosa (Cymbopogon martinii, Roxb. wats. var. motia) inflorescence with unopened spikelets accumulated essential oil substantially. Geraniol and geranyl acetate together constituted about 90% of the palmarosa oil. The proportion of geranyl acetate in the oil decreased significantly with a corresponding increase of geraniol, during inflorescence development. An esterase enzyme activity, involved in the transformation of geranyl acetate to geraniol, was detected from the immature inflorescence using a gas chromatographic procedure. The enzyme, termed as geranyl acetate cleaving esterase (GAE), was found to be active in the alkaline pH range with the optimum at pH 8.5. The catalysis of geranyl acetate was linear up to 6 h, and after 24 h of incubation, 75% of the geranyl acetate incubated was hydrolyzed. The GAE enzymic preparation, when stored at 4 degrees C for a week, was quite stable with only 40% loss of activity. The physiological role of GAE in the production of geraniol during palmarosa inflorescence development has been discussed.

Acute, short-term, and subchronic oral toxicity of 1,1,1-trichloroethane in rats

1,1,1-Trichloroethane (TRI) is a widely used solvent that has become a frequent contaminant of drinking water supplies in the U.S. There is very little information available on the potential for oral TRI to damage the liver or to alter its P450 metabolic capacity. Thus, a major objective of this investigation was to assess the acute, short-term, and subchronic hepatotoxicity of oral TRI. In the acute study, male Sprague-Dawley (S-D) rats were gavaged with 0, 0.5, 1, 2, or 4 g TRI/kg bw and killed 24 h later. No acute effects were apparent other than CNS depression. Other male S-D rats received 0, 0.5, 5, or 10 g TRI/kg po once daily for 5 consecutive days, rested for 2 days, and were dosed for 4 additional days. Groups of the animals were sacrificed for evaluation of hepatotoxicity 1, 5, and 12 days after initiation of the short-term experiment. This dosage regimen caused numerous fatalities at 5 and 10 g/kg, but no increases in serum enzymes or histopathological changes in the liver. For the subchronic study, male S-D rats were gavaged 5 times weekly with 0, 0.5, 2.5, or 5.0 g TRI/kg for 50 days. The 0 and 0.5 g/kg groups were dosed for 13 weeks. A substantial number of rats receiving 2.5 and 5.0 g/kg died, apparently due to effects of repeated, protracted CNS depression. There was evidence of slight hepatocytotoxicity at 10 g/kg, but no progression of injury nor appearance of adverse effects were seen during acute or short-term exposure. Ingestion of 0.5 g/kg over 13 weeks did not cause apparent CNS depression, body or organ weight changes, clinical chemistry abnormalities, histopathological changes in the liver, or fatalities. Additional experiments did reveal that 0.5 g/kg and higher doses induced hepatic microsomal cytochrome P450IIE1 (CYP2E1) in a dose- and time-dependent manner. Induction of CYP2E1 activity occurred sooner, but was of shorter duration than CYP2B1/2 induction. CYP1A1 activity was not enhanced. In summary, 0.5 g/kg po was the acute, short-term, and subchronic NOAEL for TRI, for effects other than transient CYP2E1 induction, under the conditions of this investigation. Oral TRI appears to have very limited capacity to induce P450s or to cause liver injury in male S-D rats, even when administered repeatedly by gavage in near-lethal or lethal dosages under conditions intended to maximize hepatic effects.

Pleiotropic morphological and abiotic stress resistance phenotypes of the hyper-abscisic acid producing Abo- mutant in the periwinkle Catharanthus roseus

The pleiotropic properties of a abo abo (Abo-) gamma-ray induced mutant of Catharanthus roseus cv. Nirmal, selected among the M2 generation seeds for ability to germinate at 45 degrees C, are described. The mutant produced seeds possessing tricotyledonous embryos, unlike the typically dicotyledonous embryos present in the wild type Abo+ seeds. In comparison to Abo+ adults, the mutant plants had short stature and lanceolate leaves. The vascular bundles in the leaves and stem were poorly developed. Leaf surfaces were highly trichomatous, epidermal, cortex and mesophyll cells were small sized and a large majority of stomata were closed. Besides high temperature, the mutant was salinity and water-stress tolerant. The abscisic acid (ABA) content in the leaves was about 500-fold higher. The genetic lesion abo responsible for the above pleiotropy was recessive and inherited in Mendelian fashion. The seedlings and adult plants of the mutant accumulated higher proline than Abo+ plants. The phenotypes of abo abo mutants permitted the conclusions that (i) the mutant synthesizes ABA constitutively, (ii) both ABA-dependent and ABA independent pathways for proline and betaine accumulation are functional in the mutant, and (iii) cell division, elongation and differentiation processes in embryo and adult plant stages are affected in the mutant

The T-cell chemokine receptor CXCR3 is expressed highly in low-grade mycosis fungoides

Three chemokines, Mig, IP-10, and I-TAC, are expressed highly in the epidermis. We examined the expression of the receptor for these chemokines, CXCR3, in cutaneous T-cell lymphoma. We compared CXCR3 expression with that of cutaneous lymphocyte antigen (CLA) and the activation marker CD30. CXCR3 was expressed by at least a subset of tumor lymphocytes in all 25 cases of low-grade mycosis fungoides (MF), with most cells positive in 20 cases. In progressed or transformed MF, CXCR3 expression was noted in 5 of 22 cases. In 4 of 5 MF cases with sequential biopsy specimens, large cell transformation was accompanied by loss of CXCR3 expression. In contrast, CLA was expressed in 35 of 42 MF cases with no significant differences in expression level between low-grade and transformed cases. In other lymphomas, CXCR3 was expressed in 4 of 4 cases of lymphomatoid papulosis, 3 of 4 cases of CD8+ cutaneous T-cell lymphoma, and 3 of 6 cases of systemic T-cell lymphoma in skin, but not in 10 cases of cutaneous anaplastic large cell lymphoma. CXCR3 expression was associated with epidermotropic T-cell tumors but was largely absent in dermal-based tumors. This phenotypic change likely influences the loss of epidermal localization.

Age-associated risk of cancer among individuals with N-acetyltransferase 2 (NAT2) mutations and mutations in DNA mismatch repair genes

Mutations in N-acetyltransferase 2 (NAT2), a highly polymorphic enzyme involved in the metabolism of xenobiotics and carcinogens, may affect risk for colorectal cancer (CRC), especially among individuals with germ-line mutations in DNA mismatch repair genes. We determined the NAT2 genotypes and allele frequencies for 86 individuals with CRC who had mutations in hMLH1, hMSH2, or hPMS1. No significant difference in time to onset was observed between rapid (NAT2*4) and slow (NAT2*5, NAT2*6, and NAT2*7) acetylators. However, when individuals were stratified separately by NAT2 polymorphism (NAT2*5, NAT2*6, and NAT2*7), those who were heterozygous at the mutant locus NAT2*7 after adjustment for the NAT2 mutant loci NAT2*5 and NAT2*6 had a significantly higher risk of CRC (hazard ratio, 2.96; P = 0.012) and all of the cancers (hazard ratio, 3.37; P = 0.00004) than individuals homozygous for wild type at the NAT2*7 allele. These findings suggest that NAT2 genotype may be an important factor in tumorigenesis of CRC and cancers related to hereditary nonpolyposis CRC among individuals with mismatch repair defects.

Detection of chromosome 11q13 breakpoints by interphase fluorescence in situ hybridization. A useful ancillary method for the diagnosis of mantle cell lymphoma

We assessed cytologic specimens from 11 mantle cell lymphomas (MCLs) and 32 other B-cell non-Hodgkin lymphomas (NHLs) for 11q13 breakpoints using a 2-color fluorescence in situ hybridization (FISH) assay that uses an 11q13 probe centered on the CCND1 gene and a centromeric chromosome 11 probe (CEP11). The number of nuclei in 200 cells were counted, and results were expressed as an 11q13/CEP11 ratio. All MCLs showed a high percentage of interphase nuclei with 3 or more 11q13 signals (mean, 74.8%; range 57%-90%). In contrast, in other B-cell NHLs the mean percentage of cells with 3 or more 11q13 signals was 9.2%. All MCLs had an elevated 11q13/CEP11 ratio (mean, 1.38). The mean ratio for other B-cell NHLs was 0.99. Two non-MCL cases, 1 large B-cell and 1 B-cell unclassified NHL, had high 11q13/CEP11 ratios of 1.15 and 1.30, respectively. Conventional cytogenetic analysis performed on the former case revealed a t(5;11)(q31;q13). Interphase FISH analysis using 11q13 and CEP11 probes is a convenient ancillary method for assisting in the diagnosis of MCL. This commercially available assay is simple to use on cytology or imprint specimens, and results can be obtained within 24 hours.

5'-->3' exonuclease-based real-time PCR assays for detecting the t(14;18)(q32;21): a survey of 162 malignant lymphomas and reactive specimens

We describe our experience using two real-time polymerase chain reaction (PCR) assays for detecting the t(14;18)(q32;q21) in a large series of non-Hodgkin's lymphomas (NHLs). These assays utilize the 5'-->3' exonuclease activity of Taq polymerase, which cleaves a probe labeled with a fluorescent reporter dye at its 5' end and a quencher dye at its 3' end during the extension phase of PCR. In a previous study, Luthra and colleagues developed these real-time PCR assays for detecting the t(14;18) involving the major and minor breakpoint cluster regions of the bcl-2 gene and assessed a small number of NHLs. In this larger study, we analyzed 135 NHLs, 6 Hodgkin's disease, 10 reactive biopsy specimens, and 11 peripheral blood specimens. The NHL group included 46 of 70 (65.7%) follicular NHLs, 1 of 2 (50%) diffuse small cleaved cell NHLs, and 13 of 24 (54.2%) diffuse large B-cell NHLs with the t(14;18) detected by conventional PCR methods. There was excellent agreement between the real-time and conventional PCR assays with overall concordance in 160 of 162 (98.8%) specimens. For the NHLs, concordance was found in 134 of 135 (99.3%) specimens. Disagreement was observed in one case of follicular NHL in which the real-time PCR assay detected bcl-2 minor breakpoint cluster region/JH DNA fusion sequences and the conventional method was negative. The overall concordance for 10 benign biopsy specimens and 11 normal peripheral blood samples was 20 of 21 (95.2%). One lymph node biopsy specimen that showed reactive follicular hyperplasia was positive for the bcl-2 minor breakpoint cluster region/JH DNA fusion sequences detected by the real-time PCR assay but was negative by conventional PCR methods. This patient had no clinical evidence of NHL. We conclude that real-time PCR assays for detecting the t(14;18) are sensitive, specific, and more convenient than conventional PCR methods.

TabBO: a model reflecting common molecular features of androgen-independent prostate cancer

We established two human prostate cancer cell lines, MDA PCa 2a and MDA PCa 2b, the TabBO model system, that reflect common features of human androgen-independent prostate cancer that are not present in other model systems: bone origin, prostate-specific antigen production, androgen receptor expression, and androgen sensitivity. We therefore hypothesized that molecular pathways in our model system reflect common alterations responsible for the progression of a subset of human prostate cancer. Progression to androgen independence has been hypothesized to be largely associated with impairment of the regulation of cell growth or apoptosis of prostate cancer cells. Therefore, in this study, we examined molecular markers known or suspected to be important in prostate cancer progression and key regulators of cell growth and apoptosis: p53, p21WAF1/CIP1, Bcl-2, Bax, retinoblastoma (Rb), and p16INK4A/MITS1. We analyzed the expression of these markers in the cell lines, their tumor of origin, and tumors derived from the cell lines by s.c. inoculation into nude mice. DNA sequencing of the entire open reading frames of the p53 and p21 genes revealed no mutations. Additionally, accumulation of the p53 protein was not found by Western blot analysis, nor was overexpression of the Bcl-2 oncoprotein detected. Bax expression was detected in MDA PCa 2a cells, whereas it was absent in MDA PCa 2b. Rb and p16 protein expression was normal as measured by both Western blot and immunochemical analyses. Immunohistochemical studies of p53, p21, Bcl-2, and Rb in both samples from the original human cancer from which the lines were derived and mouse xenografts derived from the lines revealed similar levels of protein. These results are consistent with reports indicating that 40-50% of bone metastases of prostate cancer have wild-type p53, 50-70% do not overexpress the Bcl-2 protein, and mutations in the p21 gene are rare. Therefore, we conclude that MDA PCa 2a and MDA PCa 2b reflect molecular pathways in a common subset of human androgen-independent prostate cancer and that important molecular players in apoptosis (namely, p53 and Bcl-2) seem to be intact in this subset of androgen-independent prostate cancer. Understanding the signal-transduction pathways operating in these cell lines may help to identify therapeutic targets for prostate cancer.

Effects of cyclin D1 polymorphism on age of onset of hereditary nonpolyposis colorectal cancer

A common polymorphism in the cyclin D1 gene enhances the gene's alternate splicing. The alternatively spliced product encodes an altered protein that does not contain sequences involved in the turnover of the protein. We found that hereditary nonpolyposis colorectal carcinoma patients who were homozygous or heterozygous for the mutant allele developed colorectal cancer an average of 11 years earlier than patients who were homozygous for the normal alleles. This is the first report indicating that the cyclin D1 polymorphism influences age of onset of cancer. Because cyclin D1 plays an important role in the G1 to S phase transition of the cell cycle, our findings suggest that cells with the mutant allele accumulate mutations as a result of defective mismatch repair and may also bypass the G1-S checkpoint of the cell cycle more easily than in cells not carrying the polymorphism. The polymorphism has a dominant phenotype.

Real-time 5'-->3' exonuclease-based PCR assay for detection of the t(11;14)(q13;q32)

We describe the usefulness of a real-time polymerase chain reaction (PCR) assay for detection of the t(11;14)(q13;q32), most commonly present in mantle cell lymphoma (MCL). This assay is based on the 5'-->3' exonuclease activity of Taq polymerase, which cleaves an internal probe labeled with a reporter dye at its 5' end and a quencher dye at its 3' end during PCR. The real-time t(11;14) PCR assay was established using DNA from a case of MCL with the t(11;14), amplifiable using conventional PCR and primers specific for the major translocation cluster (MTC) region of the bcl-1 locus and the immunoglobulin heavy chain joining region gene (JH). The specificity was determined by analyzing DNA from 82 cases: 50 MCL, 27 other types of non-Hodgkin lymphoma (NHL), and 5 reactive lymphoid proliferations. The real-time t(11;14) PCR results were correlated with data obtained by a conventional PCR assay. By using the real-time assay, bcl-1 MTC/JH DNA fusion sequences were detected in 25 of 50 MCLs but not in other NHLs or reactive lymphoid proliferations. Concordance between real-time and conventional PCR methods for MCL was 96% and for all samples was 98%. The results demonstrate that this real-time PCR method to detect bcl-1 MTC/JH DNA fusion sequences is specific and reliable. In addition, the results are available immediately following amplification, without standard post-PCR manipulations.