All Optical Implementation of Multi-Spin Entanglement in a Semiconductor Quantum Well

We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange interaction between localized excitons and paramagnetic impurities, can in principle be applied to entangle a large number of spins.Comment: 17 pages, 3 figure

Assessment of the role of transcript for GATA-4 as a marker of unfavorable outcome in human adrenocortical neoplasms

BACKGROUND: Malignant neoplasia of the adrenal cortex is usually associated with very poor prognosis. When adrenocortical neoplasms are diagnosed in the early stages, distinction between carcinoma and adenoma can be very difficult to accomplish, since there is yet no reliable marker to predict tumor recurrence or dissemination. GATA transcription factors play an essential role in the developmental control of cell fate, cell proliferation and differentiation, organ morphogenesis, and tissue-specific gene expression. Normal mouse adrenal cortex expresses GATA-6 while its malignant counterpart only expresses GATA-4. The goal of the present study was to assess whether this reciprocal change in the expression of GATA factors might be relevant for predicting the prognosis of human adrenocortical neoplasms. Since human adrenal cortices express luteinizing hormone (LH/hCG) receptor and the gonadotropins are known to up-regulate GATA-4 in gonadal tumor cell lines, we also studied the expression of LH/hCG receptor. METHODS: We conducted a study on 13 non-metastasizing (NM) and 10 metastasizing/recurrent (MR) tumors obtained from a group of twenty-two adult and pediatric patients. The expression of GATA-4, GATA-6, and LH/hCG receptor (LHR) in normal and tumoral human adrenal cortices was analysed using reverse transcriptase-polymerase chain reaction (RT-PCR) complemented by dot blot hybridization. RESULTS: Messenger RNA for GATA-6 was detected in normal adrenal tissue, as well as in the totality of NM and MR tumors. GATA-4, by its turn, was detected in normal adrenal tissue, in 11 out of 13 NM tumors, and in 9 of the 10 MR tumors, with larger amounts of mRNA found among those presenting aggressive clinical behavior. Transcripts for LH receptor were observed both in normal tissue and neoplasms. A more intense LHR transcript accumulation was observed on those tumors with better clinical outcome. CONCLUSION: Our data suggest that the expression of GATA-6 in human adrenal cortex is not affected by tumorigenesis. GATA-4 expression is more abundant in MR tumors, while NM tumors express more intensely LHR. Further studies with larger cohorts are needed to test whether relative expression levels of LHR or GATA-4 might be used as prognosis predictors

Apoptosis control and proliferation marker in human normal and neoplastic adrenocortical tissues

We evaluated by immunohistochemistry the expression of the Bcl-2 and p53 proteins, as markers of apoptosis control, and of MIB-1, as a marker of cell proliferation, in a series of normal and neoplastic adrenocortical tissues. The specimens were 13 normal adrenals, 13 aldosterone-producing adenomas, 13 non-functioning adenomas and 16 carcinomas. Results were calculated as percentage of immunostained cells by using specific antibodies. No p53 protein was detected in any of the adrenocortical adenomas (functioning and non functioning) or normal adrenals, while p53 was overexpressed in 15 out of 16 carcinomas. In particular, 10 adrenal cancer specimens (62.5%) showed strong staining in a high percentage (range 10–50%) of the malignant cells. The percentage of Bcl-2 positive cells was higher (P<0.05 or less) in non-functioning adenomas (8.1±1.9%) and in carcinomas (14.9±5.6%) than in normals (2.9±0.9%) and aldosterone-producing adenomas (5.3±1.3%) since four specimens of the non-functioning adenomas-group (30.7%) and six of the carcinomas-group (37.5%) showed over 10% positivity (cut-off for normal values, set at 90th percentile of our controls). MIB-1 positivity was 0.50±0.36% in normals, 0.54±0.08% in non-functioning adenomas and 0.54±0.08% in aldosterone-producing adenomas. MIB-1 was expressed in all carcinomas with values (13.7±3.1%) significantly (P<0.0006) higher than in the other groups. In conclusion, the present data indicate that the apoptosis control and proliferation activity evaluated by the p53 and MIB-1 proteins are impaired in adrenal carcinomas but preserved in adenomas, independently of their functional status. Therefore, these immunohistochemical markers, overexpressed in carcinomas only, may be useful in the diagnosis of malignancy in adrenocortical tumours. Whether Bcl-2 positivity found in some carcinomas and non-functioning adenomas may constitute, in the latter, a negative prognostic marker is still unknown

Thymidylate synthase polymorphisms, folate and B-vitamin intake, and risk of colorectal adenoma

The effects of polymorphisms in genes coding for key folate metabolism enzymes such as thymidylate synthetase (TS) on colorectal neoplasia risk are likely to be influenced by gene–gene and gene–nutrient interactions. We investigated the combined effects of three polymorphisms in the TS gene region, TSER, TS 3R G>C, and TS 1494del6, dietary intakes of folate and other B vitamins, and genotype for other folate metabolism variants, in a colorectal adenoma (CRA) case–control study. Individuals homozygous for TS 1494del6 del/del were at significantly reduced CRA risk compared to those with either ins/del or ins/ins genotypes (odds ratio 0.52; 95% confidence interval: 0.31–0.85, P=0.009). We also observed evidence of interactions between TS 1494del6 genotype and intake of folate, and vitamins B6 and B12, and MTHFR C677T genotype, with the reduction in risk in del/del homozygotes being largely confined to individuals with high nutrient intakes and MTHFR 677CC genotype (Pinteraction=0.01, 0.006, 0.03, and 0.07, respectively). TSER genotype, when considered either alone or in combination with TS 3R G>C genotype, did not significantly influence CRA risk. These findings support a role for TS in colorectal carcinogenesis, and provide further evidence that functional polymorphisms in folate metabolism genes act as low-risk alleles for colorectal neoplasia and participate in complex gene–gene and gene–nutrient interactions

Metastatic Colorectal Cancer Treatment Response Evaluation by Ultra-Deep Sequencing of Cell-Free DNA and Matched White Blood Cells

Purpose: Circulating tumor DNA (ctDNA) has the potential to guide therapy selection and monitor treatment response in patients with metastatic cancer. However, germline and clonal hematopoiesis- associated alterations can confound identification of tumorspecific mutations in cell-free DNA (cfDNA), often requiring additional sequencing of tumor tissue. The current study assessed whether ctDNA-based treatment response monitoring could be performed in a tumor tissue-independent manner by combining ultra-deep targeted sequencing analyses of cfDNA with patientmatched white blood cell (WBC)-derived DNA. Experimental Design: In total, 183 cfDNA and 49WBCsamples, along with 28 tissue samples, from 52 patients with metastatic colorectal cancer participating in the prospective phase III CAIRO5 clinical trial were analyzed using an ultra-deep targeted sequencing liquid biopsy assay. Results: The combined cfDNA and WBC analysis prevented false-positives due to germline or hematopoietic variants in 40% of patients. Patient-matched tumor tissue sequencing did not provide additional information. Longitudinal analyses of ctDNA were more predictive of overall survival than standard-of-care radiological response evaluation. ctDNA mutations related to primary or acquired resistance to panitumumab were identified in 42% of patients. Conclusions: Accurate calling of ctDNA mutations for treatment response monitoring is feasible in a tumor tissue-independent manner by combined cfDNA and patient-matched WBC genomic DNA analysis. This tissue biopsy-independent approach simplifies sample logistics and facilitates the application of liquid biopsy ctDNA testing for evaluation of emerging therapy resistance, opening new avenues for early adaptation of treatment regimens

SHMT1 1420 and MTHFR 677 variants are associated with rectal but not colon cancer

<p>Abstract</p> <p>Background</p> <p>Association between rectal or colon cancer risk and serine hydroxymethyltransferase 1 (<it>SHMT1</it>) C1420T or methylenetetrahydrofolate reductase (<it>MTHFR</it>) C677T polymorphisms was assessed. The serum total homocysteine (HCY), marker of folate metabolism was also investigated.</p> <p>Methods</p> <p>The <it>SHMT1 </it>and <it>MTHFR </it>genotypes were determined by real-time PCR and PCR-RFLP, respectively in 476 patients with rectal, 479 patients with colon cancer and in 461 and 478, respective controls matched for age and sex. Homocysteine levels were determined by HPLC kit. The association between polymorphisms and cancer risk was evaluated by logistic regression analysis adjusted for age, sex and body mass index. The population stratification bias was also estimated.</p> <p>Results</p> <p>There was no association of genotypes or diplotypes with colon cancer. The rectal cancer risk was significantly lower for <it>SHMT1 </it>TT (OR = 0.57, 95% confidence interval (CI) 0.36-0.89) and higher for <it>MTHFR </it>CT genotypes (OR = 1.4, 95%CI 1.06-1.84). A gene-dosage effect was observed for <it>SHMT1 </it>with progressively decreasing risk with increasing number of T allele (p = 0.014). The stratified analysis according to age and sex revealed that the association is mainly present in the younger (< 60 years) or male subgroup. As expected from genotype analysis, the <it>SHMT1 </it>T allele/<it>MTHFR </it>CC diplotype was associated with reduced rectal cancer risk (OR 0.56, 95%CI 0.42-0.77 vs all other diplotypes together). The above results are unlikely to suffer from population stratification bias. In controls HCY was influenced by <it>SHMT1 </it>polymorphism, while in patients it was affected only by Dukes' stage. In patients with Dukes' stage C or D HCY can be considered as a tumor marker only in case of <it>SHMT1 </it>1420CC genotypes.</p> <p>Conclusions</p> <p>A protective effect of <it>SHMT1 </it>1420T allele or <it>SHMT1 </it>1420 T allele/<it>MTHFR </it>677 CC diplotype against rectal but not colon cancer risk was demonstrated. The presence of <it>SHMT1 </it>1420 T allele significantly increases the HCY levels in controls but not in patients. Homocysteine could be considered as a tumor marker in <it>SHMT1 </it>1420 wild-type (CC) CRC patients in Dukes' stage C and D. Further studies need to clarify why <it>SHMT1 </it>and <it>MTHFR </it>polymorphisms are associated only with rectal and not colon cancer risk.</p

Toxic encephalopathy and delayed MTX clearance after high-dose methotrexate therapy in a child homozygous for the MTHFR C677T polymorphism.

BACKGROUND: High-dose methotrexate (HD-MTX) is one of the most important agents in the therapy of osteosarcoma (OSC). Acute and delayed toxicities still constitute clinical problems. Methylenetetrahydrofolate reductase (MTHFR) has a key role in the folate cycle. In case of homozygosity of the 677C-->T polymorphism, treatment with antimetabolites, such as MTX, can cause additional toxicity. CASE REPORT: In the present work, we describe the case of a 10-year-old boy with OSC. After the first HD-MTX infusion (12 g/m2/6 h) acute neurological disturbances were detected followed by severe hepatotoxicity. Plasma concentrations of MTX and 7-OH-MTX showed delayed clearance. Calcium folinate was administered to the patient until +186 hours. Tha patient was homozygous for the 677 polymorphism and wild-type for the 1298 polymorphism of the MTHFR gene. CONCLUSION: We hypothesize that MTX toxicity can be explained by the association between homozygosity of the MTHFR C677T polymorphism causing disturbances in the folate status and thus an enhanced vulnerability of the central nervous system to antimetabolites and to the prolonged MTX exposure due to delayed MTX clearance