Proteomic analysis reveals that 14-3-3 sigma in downregulated in human breast cancer cells

The class of molecular chaperones known as 14-3-3 is involved in the control of cellular growth by virtue of its apparent regulation of various signaling pathways, including the Raf/mitogen-activated protein kinase pathway. In breast cancer cells, the sigma form of 14-3-3 has been shown to interact with cyclin-dependent kinases and to control the rate of entry into mitosis. To test for a direct role for 14-3-3 in breast epithelial cell neoplasia, me have quantitated 14-3-3 protein levels using a proteomic approach based on two-dimensional electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF). We show here that 14-3-3 sigma protein is strongly down-regulated in the prototypic breast cancer cell lines MCF-7 and MDA-MB-231 and in primary breast carcinomas as compared with normal breast epithelial cells. In contrast, levels of the alpha, beta, delta, or zeta isoforms of 14-3-3 mere the same in both normal and transformed cells. The data support the idea that 14-3-3 sigma is involved in the neoplastic transition of breast epithelial cells by virtue of its role as a tumor suppressor; as such, it may constitute a robust marker with clinical efficacy for this pathology.

Proteomics of breast cancer for marker discovery and signal pathway profiling

Breast cancer is the most common form of cancer among women and the identification of markers to discriminate tumorigenic from normal cells, as well as the different stages of this pathology, is of critical importance. Two-dimensional electrophoresis has been used before for studying breast cancer, but the progressive completion of human genomic sequencing and the introduction of mass spectrometry, combined with advanced bioinformatics for protein identification, have considerably increased the possibilities for characterizing new markers and therapeutic targets. Breast cancer proteomics has already identified markers of potential clinical interest (such as the molecular chaperone 14-3-3 sigma) and technological innovations such as large scale and high throughput analysis are now driving the field. Methods in functional proteomics have also been developed to study the intracellular signaling pathways that underlie the development of breast cancer. As illustrated with fibroblast growth factor-2, a mitogen and motogen factor for breast cancer cells, proteomics is a powerful approach to identify signaling proteins and to decipher the complex signaling circuitry involved in tumor growth. Together with genomics, proteomics is well on the way to molecularly characterizing the different types of breast tumor, and thus defining new therapeutic targets for future treatment.

Young patients with colorectal cancer: How do they fare?

Background: Younger patients with colorectal cancer (CRC) have long been thought to have a poorer prognosis than older patients. Recent overseas reports, however, have disputed this. The aim of the present study was to conduct a review of data on patients with colorectal cancer collected over a 29-year period at Princess Alexandra Hospital (PAH) to ascertain the outcome of a younger subset of patients at this hospital. Methods: The PAH Colorectal Project records on 2495 patients with malignancies of the colon, rectum and anus who were treated and followed since 1971, were analysed to determine clinical presentation, treatment and outcome. A group of 61 patients with colo-rectal adenocarcinoma was identified who were aged less than 40 years at presentation. Their clinical data were then compared with the larger group of older patients. Results: There were 30 male and 31 female patients in the younger group. A positive family history was the most consistent risk factor, present in 34% of patients. Despite this, only one patient out of 61 had been diagnosed as a result of a screening programme. The Australian Clinico-Pathological Stage (ACPS), histology and distribution of tumours corresponded to that of the older patients. The overall 5-year survival among younger patients was 53%. The 5-year survival rates in younger patients were better than that for older patients for ACPS A and B, reaching statistical significance for both of these stages. Conclusions: Our results indicate that younger patients with colorectal cancer have the potential to do just as well as older ones. With the influence of a family history of colorectal cancer being very apparent in this group, greater emphasis should be placed on an adequate screening programme for them.

Human trypsinogen in colorectal cancer

Trypsinogen (TRY), the precursor to the serine protease trypsin, is found in the pancreas and mediates digestive proteolysis in the small intestine. Differential display of cDNAs expressed by human colorectal tumor tissues compared with adjacent normal colonic mucosa identified an isoform of TRY (TRY2) up-regulated in colorectal cancers. Northern blot analysis of RNA isolated from a series of 28 malignant colon tumors and corresponding normal mucosa showed that TRY transcripts were up-regulated 2- to 33-fold in 29% of tumors. Further, TRY mRNA was expressed in 6 colorectal cancer cell lines, with highest levels detected in the metastatic tumor lines SW620 and HT29. Immunostaining for TRY protein expression showed intense immunoreactivity in the supranuclear cytoplasm of colon tumors in 16% of tissue specimens. To evaluate the relative contributions of 2 isoforms of TRY, TRY1 and TRY2, to total TRY mRNA expression, a semiquantitative multiplex RT-PCR assay was developed. TRY2 mRNA was detected in all 6 colorectal tumor cell lines, whereas TRY1 mRNA was expressed only in the metastatic tumor lines, showing that the high levels of TRY expression in the metastatic tumor lines are likely due to up-regulation of TRY1. Evaluation of TRY1 and TRY2 mRNA expression by multiplex RT-PCR in a series of 20 colon tumor tissues representative of the range of tumor progression showed that TRY2 mRNA was expressed much more commonly than TRY1 mRNA in normal mucosa (26% vs. 6%) as well as in primary tumor tissues (65% vs. 15%). These data demonstrate that TRY2 is the dominant TRY in colon tissue and suggest that up-regulation of TRY1 expression in colon tumors may be associated with a metastatic phenotype. (C) 2001 Wiley-Liss, Inc.

TTYH2, a human homologue of the Drosophila melanogaster gene tweety, is located on 17q24 and upregulated in renal cell carcinoma

Using differential display PCR, we identified a novel gene upregulated in renal cell carcinoma. Characterization of the full-length cDNA and gene revealed that the encoded protein is a human homologue of the Drosophila melanogaster Tweety protein, and so we have termed the novel protein TTYH2. The orthologous mouse cDNA was also identified and the predicted mouse protein is 81% identical to the human protein. The encoded human TTYH2 protein is 534 amino acids and, like the other members of the tweety-related protein family, is a putative cell surface protein with five transmembrane regions. TTYH2 is located at 17q24; it is expressed most highly in brain and testis and at lower levels in heart, ovary, spleen, and peripheral blood leukocytes. Expression of this gene is upregulated in 13 of 16 (81%) renal cell carcinoma samples examined. In addition to a putative role in brain and testis, the overexpression of TTYH2 in renal cell carcinoma suggests that it may have an important role in kidney tumorigenesis.

Molecular genetics of schizophrenia

1. Schizophrenia is a chronic, disabling brain disease that affects approxmately 1% of the world's population. It is characterized by delusions, hallucinations and formal thought disorder, together with a decline in socio-occupational functioning. While the causes for schizophrenia remain unknown, evidence from family, twin and adoption studies clearly demonstrates that it aggregates in families, with this clustering largely attributable to genetic rather than cultural or environmental factors. Identifying the genes involved, however, has proven to be a difficult task because schizophrenia is a complex trait characterized by an imprecise phenotype, the existence of phenocopies and the presence of low disease penetrance, 2. The current working hypothesis for schizophrenia causation is that multiple genes of small to moderate effect confer compounding risk through interactions with each other and with non-genetic risk factors, The same genes may be commonly involved in conferring risk across populations or they may vary in number and strength between different populations. To search for evidence of such genetic loci, both candidate gene and genome-wide linkage studies have been used in clinical cohorts collected from a variety of populations. Collectively, these works provide some evidence for the involvement of a number of specific genes (e.g. the 5-hydroxytryptamine (5-HT) type 2a receptor (5-HT2a) gene and the dopamine D-3 receptor gene) and as yet unidentified factors localized to specific chromosomal regions, including 6p, 6q, 8p, 13q and 22q, These data provide suggestive, but no conclusive, evidence for causative genes. 3. To enable further progress there is a need to: (i) collect fine-grained clinical datasets while searching the schizophrenia phenotype for subgroups or dimensions that may provide a more direct route to causative genes; and (ii) integrate recent refinements in molecular genetic technology, including modern composite marker maps, DNA expression assays and relevant animal models, while using the latest analytical techniques to extract maximum information in order to help distinguish a true result from a false-positive finding.

Safety and efficacy of low anterior en bloc resection as part of cytoreductive surgery for patients with ovarian cancer

Objective. To examine the feasibility and safety of a low anterior resection of the rectosigmoid plus adjacent pelvic tumour as part of primary cytoreduction for ovarian cancer. Methods. This study included 65 consecutive patients with primary ovarian cancer who had debulking surgery from 1996 through 2000. All patients underwent an en bloc resection of ovarian cancer and a rectosigmoid resection followed by an end-to-end anastomosis. Parameters for safety and efficacy were considered as primary statistical endpoints for the aim of this analysis. Results. Postoperative residual tumour was nil, 1 cm in 14, 34, and 14 patients, respectively. The median postoperative hospital stay was 11 days (range, 6 to 50 days). Intraoperative complications included an injury to the urinary bladder in one patient. Postoperative complications included wound complications (n=14, 21.5%), septicemia (n=9, 13.8%), cardiac complications (n=7, 10.8%), thromboembolic complications (n=5, 7.7%) ileus (n=2, 3.1%) anastomotic leak (n=2, 3.1%) and fistula (n=1, 1.5%). Reasons for a reoperation during the same admission included repair of an anastomotic leak (n=1), postoperative hemorrhage (n=1), and wound debridement (n=1). Wound complications, septicemia, and anastomotic leak formation were more frequent in patients who had a serum albumin level of less than or equal to 30 g/L preoperatively. There was one surgically related mortality in a patient who died from a cerebral vascular accident 2 days postoperatively. Conclusions. An en bloc resection as part of primary cytoreductive surgery for ovarian cancer is effective and its morbidity is acceptably low. (C) 2001 Academic Press.

Accuracy of frozen section for the operative management of endometrial cancer

Objective To assess the accuracy of intra-operative frozen section reports at identifying the features of high risk uterine disease compared with final histopathology. Design Retrospective study. Methods The records, of 460 patients with uterine cancer registered with the Queensland Centre for Gynaecological Cancer between January 1, 1996 and December 31, 1998 were reviewed. Intra-operative frozen section was undertaken in 260 patients with endometrial adenocarcinoma. Frozen section pathology was compared with the final histopathology reports. Inter-observer reliability was assessed using percentage agreement and kappa statistics. Clinical notes were also reviewed to determine if errors resulted in sub-optimal patient care. Results Respectively, tumour grade and depth of myometrial invasion were accurately reported in 88.6% of cases (expected 61.5%, Kappa 0.70) and 94.7% (expected 53.8%, Kappa 0.89). Errors were predominantly attributable to difficulties with respect to the interpretation of tumour grade. The error resulted in the patient receiving sub-optimal surgical management in only I I cases (5.3%) Conclusion Frozen section is accurate at identifying the features of high risk uterine disease in the setting of endometrial cancer and can play an important role in directing primary operative management.

The progesterone receptor exon 4 Va1660Leu G/T polymorphism and risk of breast cancer in Australian women

An Alu insertion polymorphism of the progesterone receptor (PR) was reported recently to be associated with a reduced risk of breast cancer, with risks of 0.8- and 0.3-fold associated with the heterozygote and homozygote genotypes, respectively. This intronic variant is considered to be in linkage disequilibrium with an exon 4 hinge region G to T Val660Leu polymorphism. We investigated whether the exon 4 PR polymorphism was associated with breast cancer in Australian women, using a population-based study of 1452 cases and 793 controls, half of whom were