Identification of a unique anti-Ro60 subset with restricted serological and molecular profiles

Anti-Ro60 is one of the most common and clinically important serum autoantibodies that has a number of diagnostic and predictive capabilities. Most diagnostic laboratories report this simply as a qualitative positive/negative result. The objective of this study was to examine the clinical and serological relevance of a novel subset of anti-Ro60 in patients who display low levels of anti-Ro60 (anti-Ro60^low ). We retrospectively identified anti-Ro60 sera during a 12-month period at a major immunopathology diagnostic laboratory in Australia. These all were anti-Ro60-precipitin-positive on the diagnostic gold standard counter-immuno-electrophoresis (CIEP). Lineblot immunoassay was used to stratify patients into either anti-Ro60^low or anti-Ro60^high subsets. We compared the medical and laboratory parameters associated with each group. Enzyme-linked immunosorbent assay (ELISA) and mass spectrometry techniques were used to analyse the serological and molecular basis behind the two subsets. Anti-Ro60^low patients displayed less serological activity than anti-Ro60^high patients with less intermolecular spreading, hypergammaglobulinaemia and less tendency to undergo anti-Ro60 isotype-switching than anti-Ro60^high patients. Mass spectrometric typing of the anti-Ro60^low subset showed restricted variable heavy chain subfamily usage and amino acid point mutations. This subset also displayed clinical relevance, being present in a number of patients with systemic autoimmune rheumatic diseases (SARD). We identify a novel anti-Ro60^low patient subset that is distinct from anti-Ro60^high patients serologically and molecularly. It is not clear whether they arise from common or separate origins; however, they probably have different developmental pathways to account for the stark difference in immunological maturity. We hence demonstrate significance to anti-Ro60^low and justify accurate detection in the diagnostic laboratory.

CHK1 inhibition in soft-tissue sarcomas: biological and clinical implications

Background

Inhibition of ChK1 appears as a promising strategy for selectively potentiate the efficacy of chemotherapeutic agents in G1 checkpoint-defective tumor cells such as those that lack functional p53 protein. The p53 pathway is commonly dysregulated in soft-tissue sarcomas (STS) through mutations affecting TP53 or MDM2 amplification. GDC-0575 is a selective ATP-competitive inhibitor of CHK1.

Methods

We have performed a systematic screening of a panel of 10 STS cell lines by combining the treatment of GDC-0575 with chemotherapy. Cell proliferation, cell death and cell cycle analysis were evaluated with high throughput assay. In vivo experiments were carried out by using TP53-mutated and TP53 wild-type patient-derived xenograft models of STS. Clinical activity of GDC-0575 combined with chemotherapy in patients with TP53-mutated and TP53 wild-type STS was also assessed.

Results

We found that GDC-0575 abrogated DNA damage-induced S and G2-M checkpoints, exacerbated DNA double-strand breaks and induced apoptosis in STS cells. Moreover, we observed a synergistic or additive effect of GDC-0575 together with gemcitabine in vitro and in vivo in TP53-proficient but not TP53-deficient sarcoma models. In a phase I study of GDC-0575 in combination with gemcitabine, two patients with metastatic TP53-mutated STS had an exceptional, long-lasting response despite administration of a very low dose of gemcitabine whereas one patient with wild-type TP53 STS had no clinical benefit. Genetic profiling of samples from a patient displaying secondary resistance after 1 year showed loss of one preexisting loss-of-function mutation in the helical domain of DNA2.

Conclusion

We provide the first preclinical and clinical evidence that potentiation of chemotherapy activity with a CHK1 inhibitor is a promising strategy in TP53-deficient STS and deserves further investigation in the phase II setting.

High-depth sequencing of paired primary and metastatic tumours: Implications for personalised medicine

BACKGROUND

Next-generation sequencing of large panel of genes had been associated with clinical benefit in a significant proportion of patients with advanced cancer. However, the molecular profile of the primary tumour from the initial surgical specimen might significantly differ from the molecular profile in a tumour sample obtained from a biopsy of a metastatic site.

PATIENTS AND METHODS

We compare the genetic profile of primary tumours and paired metastases by using a large panel of cancer genes. Training and validation set including a total of 152 primary and metastatic tumour pairs were sequenced (up to 429 genes) focussing on variants described in the Catalogue of Somatic Mutations in Cancer (COSMIC).

RESULTS

Training and validation set including a total of 152 primary and metastatic tumour pairs were sequenced focussing on variants described in COSMIC. Agreement rate between the couples of primary and metastasis on COSMIC variants was 65% (24/37) and 43% (49/115) in the training and validation cohort, respectively. That rose to 74% (20/27) and 58% (42/73) when focussing on targetable mutations. In five cases, the discordance was related to appearance of secondary resistance mutation, giving a targetable refined agreement rate of 67% (67/100).

CONCLUSION

Up to 40% of paired primary tumour/metastases have discordant molecular profile. Liquid biopsies may overcome, in the near future, the limits of tumour tissue genotyping.

Negative regulation of RNA-binding protein HuR by tumor-suppressor ECRG2

Esophageal cancer-related gene 2 (ECRG2) is a newer tumor suppressor whose function in the regulation of cell growth and apoptosis remains to be elucidated. Here we show that ECRG2 expression was upregulated in response to DNA damage, and increased ECRG2 expression induced growth suppression in cancer cells but not in non-cancerous epithelial cells. ECRG2-mediated growth suppression was associated with activation of caspases and marked reduction in the levels of apoptosis inhibitor, X chromosome-linked inhibitor of apoptosis protein (XIAP). ECRG2, via RNA-binding protein human antigen R (HuR), regulated XIAP mRNA stability and expression. Furthermore, ECRG2 increased HuR ubiquitination and degradation but was unable to modulate the non-ubiquitinable mutant form of HuR. We also identified missense and frame-shift ECRG2 mutations in various human malignancies and noted that, unlike wild-type ECRG2, one cancer-derived ECRG2 mutant harboring glutamic acid instead of valine at position 30 (V30E) failed to induce cell death and activation of caspases. This naturally occurring V30E mutant also did not suppress XIAP and HuR. Importantly, the V30E mutant overexpressing cancer cells acquired resistance against multiple anticancer drugs, thus suggesting that ECRG2 mutations appear to have an important role in the acquisition of anticancer drug resistance in a subset of human malignancies.

Supplementation of collagen scaffolds with SPARC to facilitate mineralization

The extracellular matrix-associated protein, SPARC (Secreted Protein Acidic and Rich in Cysteine) is known to play a role in the mineralization of collagen in bone formation. The objectives of this study were to determine: 1) if SPARC supplementation of type 1 collagen scaffolds in vitro facilitated the binding of pre-formed HA nanoparticles added to the scaffolds; 2) if SPARC supplementation of the scaffolds enhanced the uptake of calcium and phosphorus from calcium phosphate solutions; and 3) if pretreatment in a calcium phosphate solution enhanced the subsequent binding of the nanoparticles. A related objective was to begin to determine the behavior of mesenchymal stem cells in the scaffolds when the constructs were grown in osteogenic medium. The calcium and phosphorus contents of the scaffolds were evaluated by inductively coupled plasma analysis, and the elastic modulus of the scaffolds determined by unconfined compression testing. Scaffolds were seeded with goat bone marrow-derived mesenchymal stem cells and the cell-seeded constructs grown in osteogenic medium. Supplementation of the scaffolds with as little as 0.008 % SPARC (by wt. of collagen) resulted in an increase in the binding of hydroxyapatite nanoparticles to the scaffold, but had no effect on incorporation of calcium or phosphorus from a calcium phosphate solution. The incorporation of hydroxyapatite nanoparticles into the scaffolds did not result in an increase in modulus. Supplementation of the scaffolds with SPARC and the increase in the binding of hydroxyapatite nanoparticles did not affect the proliferation of mesenchymal stem cells.

Inter-critical and critical excessive daily sleepiness in episodic migraine patients

The objective of this study was to determine the relationship between sleepiness and migraine in the intercritical period and to evaluate the time course of critical drowsiness during the attacks. One hundred patients fulfilling IHCD 2nd (2004) criteria for migraine without aura were compared to 100 healthy subjects. Habitual excessive daily sleepiness, evaluated by means of Epworth Sleepiness Scale, was not more frequent in patients with episodic migraine than in controls (12% migraineurs vs. 8% controls, NS). The analysis of critical sleepiness by means of Stanford Sleepiness Scale (SSS) revealed a beginning of sleepiness increase before the attack onset, starting 12 h before, a peak of SSS values at the migraine attack onset and then a gradual decrease to reach baseline values only 12-24 h later. Moreover, patients responding to symptomatic drugs showed a greater and faster decrease of critical sleepiness in comparison with non-responder migraineurs; this finding allows excluding the role of medications in promoting critical somnolence and together with critical drowsiness time-course supports the hypothesis that vigilance impairment could be related to migraine pathogenesis.

Genomic and transcriptomic differences between lobular and luminal ductal invasive carcinoma

Abstract #2039

Background: Invasive lobular carcinomas (ILCs) of the breast are characterized by morphological and phenotypical features such as small, non cohesive, estrogens receptors positive cells, low proliferation rates with a metastatic spreading in numerous and different unusual metastatic sites as compared to invasive ductal carcinomas (IDCs) (Ferlicot et al, 2004). We have previously shown that ILCs presented the same outcome than IDCs (Sastre-Garau et al, 1996). Beyond E-cadherin genomic inactivation, little is known about the underlying genomic and transcriptomic alterations that may discriminate both subtypes.
 Aims of the study: To get an insight into ILC biological specificities, we performed a combined genomic (aCGH), transcriptomic (Affymetrix U133A+B) and phenotypic analysis of a series of 24 lobular carcinomas and compared it to a series of 41 ER-positive IDCs.
 Results: Analysis of genomic copy number showed that ILCs and IDCs shared gains of the 1q11-q43 region and losses of 16q12.1-q24.2 and 17pter-p13.1 regions. ILCs presented the 22q12-q13 loss but not the 16pter-p11.2 gain and 11q23-q24 loss as observed in IDCs. Eight different regions of high level amplifications were found in 29% of ILC cases (7/24 cases). Only one region of amplification was recurrent and observed in 5 out of 24 tumors (21% of the cases). This recurrent region of amplification was localized on the 11q13.2 region and encompassed the Cyclin D1 (CCND1) and Cortactin (CTTN) genes. ILCs and IDCs had comparable overall survival rates, however, unsupervised hierarchical clustering of transcriptomic data showed that ILCs and IDCs clustered apart. Genes involved in cell adhesion and motility, lipid/fatty transport and metabolism and electron transport were differentially expressed between the two groups.
 Conclusions: This integrated analysis emphasized the biological differences between ILC and IDC and highlighted genes of interest that could be useful for diagnosis, and could be new putative therapeutical targets.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2039.

Conversion to rapamycin immunosuppression for malignancy after kidney transplantation: case reports

INTRODUCTION

Malignancies are a well-known complication of immunosuppressive therapy among renal transplant recipients, representing an important cause of long-term morbidity and mortality. Rapamycin has been shown to limit the proliferation of a number of malignant cell lines in vivo and in vitro.

METHODS

Eight patients developed the following malignancies after kidney transplantation (mean 102.6 months; range 12 to 252): metastatic gastric cancer (n = 1), metastatic colon cancer (n = 1), bilateral nephrourothelioma (n = 1), skin cancer (n = 1), Kaposi's sarcoma (n = 2), posttransplant lymphoproliferative disorder (PTLD) (n = 2). After the diagnosis of malignancy, the patients were switched from calcineurin inhibitor-based immunosuppression to rapamycin (monotherapy, n = 2), associated with steroids (n = 4) or mycophenolate mofetil (n = 2).

RESULTS

Both patients with metastatic cancer underwent chemotherapy and then succummbed after 6 and 13 months. After a mean follow-up of 20.3 months (range 2 to 47), the remaining six patients are free from cancer disease. Renal graft function was unchanged from diagnosis throughout the follow-up.

CONCLUSION

Our observations suggested that rapamycin-based immunosuppression offered the possibility of regression of nonmetastatic tumors. Nevertheless, it is difficult to assess whether tumor regression was attributed to Rapamycin treatment or to the reduced immunosuppression.

Graft failure due to hemolytic uremic syndrome recurrence

The hemolytic uremic syndrome (HUS) is a severe disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. We herein report our experience with a 43-year-old female patient who underwent a second cadaveric kidney transplantation in February 2005, for adult-onset HUS. The first renal transplantation, which was performed in 1996, required removal after 3 weeks for probable recurrence of HUS. The immunosuppressive regimen for the second transplant included basiliximab, tacrolimus, mycophenolate mofetil, and steroids. On postoperative day (POD) 7, she received steroid treatment for an acute rejection episode with improved renal function. On POD 19 due to worsening renal function, a graft biopsy showed HUS recurrence, thus we instituted hemodialysis and then plasmapheresis treatments. At two months after transplantation, the patient continued under plasmapheresis treatment due to clinical evidence of HUS. On POD 80, cytomegalovirus infection was diagnosed and intravenous gancyclovir treatment started for 3 weeks. After 110 days from transplant, a deterioration in renal function was evident: the graft was swollen and painful with Doppler ultrasound showing patency of both the renal artery and vein but, low blood flow. After 2 weeks of hemodialysis, the patient underwent transplantectomy. In adult-onset HUS the recurrence rate reduces graft survival, particularly among patients undergoing second transplantation.

Long-Term Results of Kidney Transplantation With Cyclosporine- and Everolimus-Based Immunosuppression

The aim of the study was to evaluate safety and efficacy of everolimus with cyclosporine (CsA) in de novo renal transplant recipients. The immunosuppressive regimen, including basiliximab, everolimus (3 mg), and low-dose CsA, was administered to 17 patients, of whom 15 were part of a multicenter randomized study that stipulated cessation of steroids at 7 days posttransplantation in 5 recipients. Five patients underwent dialysis after transplantation for delayed graft function (DGF; 29%), all of whom showed a good recovery within 3 weeks. The mean follow-up was 45.7 months (SD +/- 13). The 1-year graft survival was 100%. We observed one acute rejection episode. No patient experienced a cytomegalovirus infection. Increased cholesterol and triglyceride levels were reported in almost all patients. Severe arthralgia (n = 3) was treated by everolimus dose reduction to maintain trough levels at 3 ng/mL. We noted a high rate of switch to mycophenolate mofetil (MMF) throughout follow-up (n = 7), due to everolimus-induced side effects. However, we did not observe normalization of lipids after the switch: patients always required stain treatment, resulting in slightly lower serum cholesterol and triglycerides. Everolimus plus CsA was effective to prevent acute rejection after kidney transplantation. To manage the induced side effects of the drugs C(2) monitoring is mandatory, targeting 350 ng/mL during 1 year and 200 to 250 ng/mL thereafter. Careful reduction of everolimus trough levels to 3 ng/mL is recommended for patients with arthralgia.

DNA microarray allows molecular profiling of rheumatoid arthritis and identification of pathophysiological targets

This study was undertaken to evaluate the possibility to obtain a molecular signature of rheumatoid arthritis (RA) comparatively osteoarthritis (OA), and to lay the bases to develop new diagnostic tools and identify new targets. Microarray technology was used for such an analysis. The gene expression profiles of synovial tissues from patients with confirmed RA, and patients with OA were established and compared. A set of 63 genes was selected, based, more specifically, on their overexpression or underexpression in RA samples compared to OA. Results for six of these genes have been verified by quantitative PCR using both samples identical to those used in the microarray experiments and entirely separate samples. Expression profile of the 48 known genes allowed the correct classification of additional RA and OA patients. Furthermore, the distinct expression of three of the selected genes was also studied by quantitative RT-PCR in cultured synovial cells. Detailed analysis of the expression profile of the selected genes provided evidence for dysregulated biological pathways, pointed out to chromosomal location and revealed novel genes potentially involved in RA. It is proposed that such an approach allows valuable diagnosis/prognostics tools in RA to be established and potential targets for combating the disease to be identified.

Cranio-cervical necrotizing fascitiis: case report and review of the literature

Necrotising fascitiis is a rapidly progressive bacterial infection of the soft tissues and generally attacks the walls of the abdomen, the perineum, the limbs or, to a lesser degree, the cranio-cervical area. In the latter region, the infection involves the soft tissues of the neck, in a more or less extensive manner, and causes diffuse necrosis. Crepitation, areas with linear infiltration and others with fluctuation are detected on manual examination. Systemic symptoms such as fever, tachycardia, tachypnoea and signs of septic shock are always present, at least during the more advanced stages of the disease. Computed tomography may prove fundamental since it reveals an increase in the thickness and degree of impregnation of the cervical soft tissues, as well as the presence of liquid or gaseous infiltration in the thoracic areas, especially in cases of mediastinitis. Personal experience in a case is described which led to a review of the literature. The best approach in the management of this devastating condition is early diagnosis, adequate antibiotic treatment and radical surgical procedures, which may often need to be repeated several times.

Automatic classification of HITS into artifacts or solid or gaseous emboli by a wavelet representation combined with dual-gate TCD

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) can detect high-intensity transient signals (HITS) in the cerebral circulation. HITS may correspond to artifacts or solid or gaseous emboli. The aim of this study was to develop an offline automated Doppler system allowing the classification of HITS.

METHODS

We studied 600 HITS in vivo, including 200 artifacts from normal subjects, 200 solid emboli from patients with symptomatic internal carotid artery stenosis, and 200 gaseous emboli in stroke patients with patent foramen ovale. The study was 2-fold, each part involving 300 HITS (100 of each type). The first 300 HITS (learning set) were used to construct an automated classification algorithm. The remaining 300 HITS (validation set) were used to check the validity of this algorithm. To classify HITS, we combined dual-gate TCD with a wavelet representation and compared it with the current "gold standard," the human experts.

RESULTS

A combination of the peak frequency of HITS and the time delay makes it possible to separate artifacts from emboli. On the validation set, we achieved a sensitivity of 97%, a specificity of 98%, a positive predictive value (PPV) of 99%, and a negative predictive value (NPV) of 94%. To distinguish between solid and gaseous emboli, where positive refers now to the solid emboli, we used the peak frequency, the relative power, and the envelope symmetry of HITS. On the validation set, we achieved a sensitivity of 89%, a specificity of 86%, a conditional PPV of 89%, and a conditional NPV of 89%.

CONCLUSIONS

An automated wavelet representation combined with dual-gate TCD can reliably reject artifacts from emboli. From a clinical standpoint, however, this approach has only a fair accuracy in differentiating between solid and gaseous emboli.

Opportunities for control of hospital costs for total joint arthroplasty after initial cost containment

Financial analysis of 391 joint replacement operations performed during 1996 determined that almost 80% of the hospital cost for joint replacement procedures was generated in the operating room, nursing units, recovery room, and pharmacy during the first 48 hours of hospitalization. Attempts to control or reduce the hospital cost of joint replacement operations should focus on these specific areas of opportunity.