Utilization of Drosophila eye to probe the functions of two mammalian serine/threonine kinases, Snk and HsHPK

Here we report a quick functional analysis of two mammalian serine/threonine kinases, a serum inducible kinase (Snk) and Homo sapiens hepatoma protein kinase (HsHPK), using Drosophila eye as a model system. We generated transgenic fly lines carrying constructs of both kinases under control of the GAL upstream activating sequence (UAS). Each UAS line was then crossed to a line in which GAL4 expression was driven by one of the following promoters, eyeless (ey), glass or decapentaplegic. Thus, different kinase mutants can be ectopically expressed in a promoter-dependent manner. We observed that the ectopic expression of either the wild-type or active form of Snk driven by the glass promoter resulted in a rough-eye phenotype. Nevertheless, the ectopic expression of HsHPK under the control of the ey promoter resulted in a small-eye phenotype. The results of this study demonstrated that ectopic expression of these two mammalian genes could be achieved by the regulation of Drosophila promoters. In addition, the effects of these ectopically expressed genes on eye development could be an implication of their functions with respect to cell proliferation and differentiation. Thus, Drosophila eye, with the powerful genetic tools and vast information on eye development available, can be a useful system to probe the functions of mammalian genes in the postgenome era.

Ischaemic change of the human intestine after total portal occlusion during liver resection

This is a clinical study of the use of several monitoring techniques to evaluate the effect of total hepatic inflow occlusion on intestinal ischaemia during liver resection. A total of 8 patients was studied. Parameters measured included intestinal oxygen extraction ratio, portal venous and arterial lactate levels and intestinal intramucosal pH (pHi), measured by an intraluminal tonometer. When venous outflow of the intestine was occluded, intestinal oxygen extraction ratio increased and portal venous lactate increased significantly, but arterial lactate did not increase significantly until after 60 minutes of occlusion. Intestinal pHi decreased significantly after 60 minutes. Following release of the occlusion, oxygen extraction and pHi returned to normal in 7 out of 8 patients. The 1 patient who had a persistent decrease in pHi died postoperatively. These findings indicate that a marked drop in pHi after total portal occlusion and persistent low pHi following the release of a portal occlusion are associated with the development of complications and mortality during liver resection.

Tie-1 tyrosine kinase is an independent prognostic indicator for invasive breast cancer

Receptor tyrosine kinases are known to be involved in the growth, progression and metastasis of solid tumors. We investigated the relationship between tie-1 expression and progression of invasive ductal breast carcinoma with immunohistochemical analysis. Tie-1 protein was detected in the microvessel endothelial cells and cytoplasm of tumor cells. The tumor size and stage were significantly associated with the expression of tie-1, which portends a worse 5-year disease-free status (39.3% v 59.2%, p = 0.07) and overall survival rate (67.3% v 93%, p = 0.02) than those without tie-1 expression. Multivariate analysis demonstrated that larger tumor size, presence of lymph node metastasis and tie-1 expression were independent prognostic parameters, both in 5-year disease-free survival and overall survival. Patients with lymph node metastases and tie-1 expression had the worst 5-year disease-free survival (0%) and overall survival (42.4%) compared to those without tie-1 expression (50.2%, 85%). In lymph node negative patients, those without tie-1 expression had better 5-year disease-free survival and overall survival (72.9%, 100%) compared to those with tie-1 expression (65.5%, 87.7%). We conclude that tie-1 expression is an independent prognostic factor for invasive ductal breast carcinoma, adversely affecting survival of breast cancer patients with positive nodes to a significant extent.

Peptoid oligomers with alpha-chiral, aromatic side chains: effects of chain length on secondary structure

Oligomeric N-substituted glycines or "peptoids" with alpha-chiral, aromatic side chains can adopt stable helices in organic or aqueous solution, despite their lack of backbone chirality and their inability to form intrachain hydrogen bonds. Helical ordering appears to be stabilized by avoidance of steric clash as well as by electrostatic repulsion between backbone carbonyls and pi clouds of aromatic rings in the side chains. Interestingly, these peptoid helices exhibit intense circular dichroism (CD) spectra that closely resemble those of peptide alpha-helices. Here, we have utilized CD to systematically study the effects of oligomer length, concentration, and temperature on the chiral secondary structure of organosoluble peptoid homooligomers ranging from 3 to 20 (R)-N-(1-phenylethyl)glycine (Nrpe) monomers in length. We find that a striking evolution in CD spectral features occurs for Nrpe oligomers between 4 and 12 residues in length, which we attribute to a chain length-dependent population of alternate structured conformers having cis versus trans amide bonds. No significant changes are observed in CD spectra of oligomers between 13 and 20 monomers in length, suggesting a minimal chain length of about 13 residues for the formation of stable poly(Nrpe) helices. Moreover, no dependence of circular dichroism on concentration is observed for an Nrpe hexamer, providing evidence that these helices remain monomeric in solution. In light of these new data, we discuss chain length-related factors that stabilize organosoluble peptoid helices of this class, which are important for the design of helical, biomimetic peptoids sharing this structural motif.

Reappraisal of surgical risk and prognosis for periampullary lesions after pancreaticoduodenectomy

BACKGROUND

Pancreaticoduodenectomy remains a high-risk and formidable challenge to many surgeons. This study reappraised the surgical risk and prognosis for periampullary lesions in patients undergoing pancreaticoduodenectomy before and after 1990.

METHODS

Data on 308 patients with periampullary lesions undergoing pancreaticoduodenectomy were analyzed. The surgical risk was assessed by a variety of factors. Prognoses for periampullary cancers were determined and compared.

RESULTS

The overall surgical mortality, morbidity and pancreatic leakage were 12.7%, 47.7% and 14.9% respectively. Surgical morbidity (43.5% vs. 51.6%) and pancreatic leakage (12.9% vs. 16.8%) did not change significantly before 1990 and after 1990. Surgical mortality significantly decreased from 17.1% before 1990 to 8.7% after 1990 (p = 0.043). Surgeons having more experience in performing pancreaticoduodenectomy (count > 20) made significantly lowest rates of surgical mortality, pancreatic leakage and bile leakage, as compared with those having performed this surgery with medium count (10-20) or low count (< 10). Statistically, pancreatic leakage was highly associated with operative mortality, (p < 0.001). As analysed by multivariate logistic regression, the most independent risk factor of surgical mortality after pancreaticoduodenectomy was pancreatic leakage (odds ratio = 12.1), followed by date of operation (odds ratio = 2.5). The 5-year survival rate for overall periampullary cancers was 23.0%, with the highest in ampulla of Vater cancer (32.7%), followed by duodenal cancer (18.0%), distal common bile duct cancer (12.3%) and pancreatic head cancer (5.5%) (p < 0.001).

CONCLUSIONS

Surgical morbidity following pancreaticoduodenectomy remains high and unchanged while surgical mortality has significantly reduced. Pancreatic leakage is the most independent risk factor of surgical mortality. Patients with periampullary lesions appear to benefit from the experience of surgeons. The overall 5-year survival is most favorable for ampulla of Vater cancer and worst for pancreatic head cancer.

p53 amino acids 339-346 represent the minimal p53 repression domain

The p53 tumor suppressor protein functions as an activator and also as a repressor of gene transcription. Currently, the mechanism of transcriptional repression by p53 remains poorly understood. To help clarify this mechanism, we carried out studies designed to identify the minimal repression domain that inhibits p53 transcriptional activities. We found only eight amino acids (339) of the COOH-terminal domain (termed P53MRD) that possess activities of repression. The exact location of this minimal domain is on the E6-binding region, and it lacks the ability of tetramerization. P53MRD is able to repress the transcription of p53 while not affecting VP16. The mutants (amino acids M340P and F341D) of native p53 also lost transcriptional repression of the thymidine kinase chloramphenicol acetyltransferase promoter. These results suggest that this eight-amino acid element is required for the repression of p53.

Comparison of the UICC/AJCC 1992 and 1997 pN categories for gastric cancer patients after surgery

BACKGROUND/AIMS

UICC/AJCC 1997 classification changes pN category. We evaluated its prognostic impact.

METHODOLOGY

A total of 710 patients who underwent a > or = D2 gastrectomy were recruited. Among them, the data of 319 patients who had involved regional lymph nodes and no evidence of distant metastases were used for comparing the 1992 and 1997 pN categories.

RESULTS

For 1997 category, 201 patients (64%) were pN1, 75 (23.5%) pN2, and 43 (13.5%) pN3. For 1992 category, 143 patients (44.8%) were pN1, and 147(46.1%) pN2. 29 patients (9.1%) with lymph node metastasis to the hepatoduodenal ligament were distant metastasis. The 1997 pN category was a more powerful prognostic discriminant (relative risk: 2.086) than the 1992 category. Compared to the 1992 stage classification, the 1997 one had a skewed distribution of patients with marked shift of patients of stage IIIA (105-126 patients), IIIB (116-58 patients), and IV (100-122 patients). The survival difference between stage IIIA and IIIB for the 1997 stage classification is narrower than for 1992.

CONCLUSIONS

The 1997 pN category allows for estimation of prognosis superior to the 1992 category.

Arginine modulated cyclosporine-induced immune suppression in rats transplanted with gastric cancer cells

BACKGROUND

The incidence of cancer is significantly increased in kidney transplant patients receiving cyclosporine treatment. It has been reported that arginine can modify cyclosporine-induced nephrotoxicity in rats. Whether arginine interfered with cyclosporine-induced immune suppression in tumor transplant is not clear.

MATERIALS AND METHODS

Male Wistar rats were inoculated subcutaneously with human gastric cancer SC-M1 cells and separated into 4 groups; control, cyclosporine, cyclosporine plus arginine and cyclosporine plus glycine groups. The growth of SC-M1 tumor was monitored on 4, 7, 10, 14 and 21 days after tumor implant. In another set of experiments, the rats were separated into control, cyclosporine, arginine and cyclosporine plus arginine groups. After treatment for one week, mononuclear cells were collected and stained with anti-rat CD3 antibody followed by flowcytometric analysis. On the other hand, splenocytes from each group of rats were stimulated with phyto-hemaglutinin (PHA) to determine their DNA synthesis by 3H-thymidine uptake assay.

RESULTS

The SC-M1 tumors in the cyclosporine-treated rats were larger than that of the arginine plus cyclosporine group. Although SC-M1 tumors were eventually rejected in Wistar rats, the duration of detectable SC-M1 tumors in cyclosporine-treated rats was longer than that of rats treated with arginine plus cyclosporine. More infiltrating inflammatory cells were detected at an early stage of tumor rejection in rats treated with arginine plus cyclosporine than in cyclosporine-treated rats. In vitro analysis of PHA-stimulated splenocyte proliferation showed that arginine activated lymphocyte proliferation while cyclosporine inhibited lymphocyte proliferation. Arginine significantly interfered with cyclosporine-induced growth inhibition of PHA stimulated lymphocytes (p = 0.0039).

CONCLUSION

Using a tumor transplant model, we have found that dietary supplements of arginine interfered with cyclosporine-induced immunosuppression in rats. The antagonistic effect between arginine and cyclosporine on immune suppression is worthy of further investigation in organ transplant patients.

Spinal cord atrophy and reorganization of motoneuron connections following long-standing limb loss in primates

Primates with long-standing therapeutic amputations of a limb at a young age were used to investigate the possibility that deefferented motor nerves sprout to new muscle targets. Injections of anatomical tracers into the muscles proximal to the amputated stump labeled a larger extent of motoneurons than matched injections on the intact side or in normal animals, including motoneurons that would normally supply only the missing limb muscles. Although the total numbers of distal limb motoneurons remained normal, some distal limb motoneurons on the amputated side were smaller in size and simpler in form. These results suggest that deprived motoneurons survive and retain function by reinnervating new muscle targets. The sprouted motor efferents may account for some of the reorganization of primary motor cortex that follows long-standing amputation.

Stability and peptide binding specificity of Btk SH2 domain: molecular basis for X-linked agammaglobulinemia

X-linked agammaglobulinemia (XLA) is caused by mutations in the Bruton's tyrosine kinase (Btk). The absence of functional Btk leads to failure of B-cell development that incapacitates antibody production in XLA patients leading to recurrent bacterial infections. Btk SH2 domain is essential for phospholipase C-gamma phosphorylation, and mutations in this domain were shown to cause XLA. Recently, the B-cell linker protein (BLNK) was found to interact with the SH2 domain of Btk, and this association is required for the activation of phospholipase C-gamma. However, the molecular basis for the interaction between the Btk SH2 domain and BLNK and the cause of XLA remain unclear. To understand the role of Btk in B-cell development, we have determined the stability and peptide binding affinity of the Btk SH2 domain. Our results indicate that both the structure and stability of Btk SH2 domain closely resemble with other SH2 domains, and it binds with phosphopeptides in the order pYEEI > pYDEP > pYMEM > pYLDL > pYIIP. We expressed the R288Q, R288W, L295P, R307G, R307T, Y334S, Y361C, L369F, and 1370M mutants of the Btk SH2 domain identified from XLA patients and measured their binding affinity with the phosphopeptides. Our studies revealed that mutation of R288 and R307 located in the phosphotyrosine binding site resulted in a more than 200-fold decrease in the peptide binding compared to L295, Y334, Y361, L369, and 1370 mutations in the pY + 3 hydrophobic binding pocket (approximately 3- to 17-folds). Furthermore, mutation of the Tyr residue at the betaD5 position reverses the binding order of Btk SH2 domain to pYIIP > pYLDL > pYDEP > pYMEM > pYEEI. This altered binding behavior of mutant Btk SH2 domain likely leads to XLA.

Tyrosine kinases and gastric cancer

Carcinoma of the stomach is one of the most prevalent cancer types in the world today. Two major forms of gastric cancer are distinguished according to their morphological and clinicopathological classifications (well differentiated/intestinal type and poorly differentiated/diffuse type), characteristics that could also be attributed to the altered expression of different types of oncogenes or tumor suppressor genes. Significant differences exist for gastric cancer incidence comparing people of different ethnic origins, implicating various genetic and epigenetic factors for gastric oncogenesis. There are only a limited number of molecular markers available for gastric cancer detection and prognostic evaluation, among which are tyrosine kinases. There is convincing evidence that tyrosine kinases are involved in oncogenesis and disease progression for many human cancers. Amplifications of certain tyrosine kinases (c-met, k-sam and erbB2/neu) have been associated with human gastric cancer progression. Alternatively spliced transcripts and enhanced protein-expression levels for some of these tyrosine kinases are correlated with clinical outcomes for gastric cancer patients. With advent of high throughput techniques, it is now possible to detect nearly all expressed tyrosine kinases in a single screen. This increases the chance to identify additional tyrosine kinases as predictive markers for gastric cancers. In this article, we will first review the literature data concerning certain tyrosine kinases implicated in gastric carcinogenesis and then summarize more recent work which provide comprehensive tyrosine kinase profiles for gastric cancer specimens and cell lines. Two new gastric cancer molecular markers (tie-1 and mkk4) have been identified through the use of these profiles and demonstrated effective as clinical prognostic indicators.

Tissue-specific cancer-related serpin gene cluster at human chromosome band 3q26

Approximately one quarter of the identified human serpin genes are cancer-related and clustered mainly at two distinct loci: 6p25 and 18q21. We have studied a novel serpin gene cluster at 3q26 containing at least two recently identified members: the pancreas-specific protease inhibitor, pancpin (PI14), and the brain-associated protease inhibitor, neuroserpin (PI12). In this, unlike a previous study, both PI14 and PI12 at 3q26 were found to consist of 9 exons and 8 introns and to share a perfectly conserved gene organization whose pattern is very different from that of the ov-serpin family. This distinct pattern appears identical in the genomic structures of human plasminogen activator inhibitor-1 (PAI1) at 7q21 and protease nexin 1 (PI7) at 2q33-35, confirming that these four genes in three different chromosomes form a discrete subset within the serpin superfamily. As in the other three members whose gene expression is altered during tumorigenesis, PI12 expression was found to be down-regulated in tumor brain tissues and in two brain cancer cell lines: U-87 MG and H4. By screening genomic libraries, we isolated two overlapping clones showing that the marker SGC32223 (centromere) is located within intron F of PI12 and the marker WI-10077 (telomere) is located downstream of the 3'-flanking region of PI14. This finding indicates that the distance between human PI14 and PI12 is approximately 100 kb, and hence we speculate that other tissue-specific cancer-related serpin genes are likely to reside within this 3q26.1 cluster region.

Protein-tyrosine kinase and protein-serine/threonine kinase expression in human gastric cancer cell lines

Protein kinases play key roles in cellular functions. They are involved in many cellular functions including; signal transduction, cell cycle regulation, cell division, and cell differentiation. Alterations of protein kinase by gene amplification, mutation or viral factors often induce tumor formation and tumor progression toward malignancy. The identification and cloning of kinase genes can provide a better understanding of the mechanisms of tumorigenesis as well as diagnostic tools for tumor staging. In this study, we have used degenerated polymerase-chain-reaction primers according to the consensus catalytic domain motifs to amplify protein kinase genes (protein-tyrosine kinase, PTK, and protein-serine/threonine kinase, PSK) from human stomach cancer cells. Following amplification, the protein kinase molecules expressed in the gastric cancer cells were cloned into plasmid vectors for cloning and sequencing. Sequence analysis of polymerase-chain-reaction products resulted in the identification of 25 protein kinases, including two novel ones. Expression of several relevant PTK/PSK genes in gastric cancer cells and tissues was further substantiated by RT-PCR using gene-specific primers. The identification of protein kinases expressed or activated in the gastric cancer cells provide the framework to understand the oncogenic process of stomach cancer.

Physical association between the EBV protein EBNA-1 and P32/TAP/hyaluronectin

Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA-1) is a protein expressed constitutively during EBV latency. It is required to support the replication of the EBV genome once per cell cycle via the latent origin of replication, oriP. EBNA-1 also can activate transcription through binding to the family repeats of oriP. We wished to identify candidate cellular protein(s) that may interact with EBNA-1 and mediate these functions. A 32-kd protein was co-immunoprecipitated with EBNA-1 from 293 cells using a monoclonal antibody EBNA.OT1x. The regions of EBNA-1 which interact with this protein were studied using two deletion clones and mapped to EBNA-1 residues 1-102 and 325-357. Deletion of this region was shown previously in a mutant of EBNA-1 which had dominant-negative effects on both DNA replication and transactivation assays. The 32-kd protein was found to react with a polyclonal antiserum against P32/TAP (HIV Tat associated protein), which is known to interact with other RNA binding proteins and the RNA splicing factor SF2. The function of P32 was therefore proposed to involve RNA processing. In addition, this molecule was recently identified as hyaluronectin, which binds hyaluronic acid. Because several reports documented that intracellular hyaluronic acid can potentially affect cell proliferation, the association between EBNA-1 and P32/TAP/hyaluronectin may help the maintenance of episomal viral DNA within proliferating cells.

Left main coronary artery aneurysm: sealing by stent graft and long-term follow-up

We describe the implantation of a stent graft to seal off the left main coronary artery aneurysm of a 64-year-old man with guidance by intravascular ultrasound. The aneurysm was successfully sealed off. At 6-month and 1-year follow-up, a small residual aneurysm reappeared, which was treated conservatively. The technical issues in closing this aneurysm and the management of the residual aneurysm are discussed.

Binding of a de novo designed peptide to specific glycosaminoglycans

The binding of glycosaminoglycans to a synthetic peptide (SKAQKAQAKQAKQAQKAQKAQAKQAKQW-CONH(2)), consisting of a hybrid consensus heparin binding sequence, is studied using circular dichroism, fluorescence anisotropy and nuclear magnetic resonance techniques. The results unveil certain novel features, most importantly, the peptide binds preferentially to iduronic acid containing glycosaminoglycans and the dissociation constant for the peptide-heparin complex was found to be 30 nM. Interestingly, higher order intermolecular association(s)/aggregation was not observed, especially at saturating concentrations of the ligand. The helical structure of the peptide backbone, induced upon binding to a particular glycosaminoglycan is directly related to their binding affinity. In our opinion, studies on such unconventional hybrid peptide sequences containing low density basic amino acid residues would lead to the design of sequence specific glycosaminoglycan binding peptides.

Prognostic significance of heat shock protein-27 expression in hepatocellular carcinoma and its relation to histologic grading and survival

BACKGROUND

The expression of heat shock protein-27 (HSP-27) has been detected in some human tumors. In this study the authors investigated HSP-27 expression in patients with hepatocellular carcinoma (HCC) and examined its prognostic significance.

METHODS

Expression of HSP-27 was studied in 58 HCC and adjacent noncancerous liver tissues by immunohistochemical stain. The relation between its expression and eight known prognostic factors was evaluated.

RESULTS

Of the 58 HCC tissues studied, the presence of HSP-27 was demonstrated in 45 tissues (77.6%); low expression (</= 25%) was demonstrated in 17 tissues and high expression (> 25%) was demonstrated in 28 tissues. A significantly higher distribution of HSP-27 expression in HCC tissues compared with adjacent noncancerous liver tissues was obtained (P < 0.0001). Patients with high HSP-27 expression had a significantly higher histologic tumor grade than those with low HSP-27 expression (P = 0.001). The 5-year disease free survival rate of patients with high HSP-27 expression was 21.4% versus 59.3% for patients with low HSP-27 expression (P < 0.001). A similar relation was observed with overall survival (33.3% vs. 64. 8%; P = 0.009). HSP-27 expression was also identified to be a significant and powerful prognostic indicator for disease free survival (odds ratio = 2.25; P = 0.034) and for overall survival (odds ratio = 2.72; P = 0.015).

CONCLUSIONS

The current study data suggest that HSP-27 expression is a powerful prognostic indicator and is related to histologic grade and survival of patients with HCC.

Prognostic significance of heat shock protein-27 expression in hepatocellular carcinoma and its relation to histologic grading and survival

BACKGROUND

The expression of heat shock protein-27 (HSP-27) has been detected in some human tumors. In this study the authors investigated HSP-27 expression in patients with hepatocellular carcinoma (HCC) and examined its prognostic significance.

METHODS

Expression of HSP-27 was studied in 58 HCC and adjacent noncancerous liver tissues by immunohistochemical stain. The relation between its expression and eight known prognostic factors was evaluated.

RESULTS

Of the 58 HCC tissues studied, the presence of HSP-27 was demonstrated in 45 tissues (77.6%); low expression (</= 25%) was demonstrated in 17 tissues and high expression (> 25%) was demonstrated in 28 tissues. A significantly higher distribution of HSP-27 expression in HCC tissues compared with adjacent noncancerous liver tissues was obtained (P < 0.0001). Patients with high HSP-27 expression had a significantly higher histologic tumor grade than those with low HSP-27 expression (P = 0.001). The 5-year disease free survival rate of patients with high HSP-27 expression was 21.4% versus 59.3% for patients with low HSP-27 expression (P < 0.001). A similar relation was observed with overall survival (33.3% vs. 64. 8%; P = 0.009). HSP-27 expression was also identified to be a significant and powerful prognostic indicator for disease free survival (odds ratio = 2.25; P = 0.034) and for overall survival (odds ratio = 2.72; P = 0.015).

CONCLUSIONS

The current study data suggest that HSP-27 expression is a powerful prognostic indicator and is related to histologic grade and survival of patients with HCC.

Adamantyl maleimide induced changes in adhesion molecules and ROS are involved in apoptosis of human gastric cancer cells

BACKGROUND

We have previously found that N-1-adamantyl maleimide (AMI) inhibited the growth of SC-M1 tumors in vitro and in vivo. The cytotoxicity of AMI on SC-M1 was accompanied by a decrease of adherent cells and the suppressive effect was associated with conformational changes in cell membrane protein. In order to determine the cellular targets of AMI in human gastric cancer SC-M1 cells, we examined AMI-induced changes in the levels of adhesion molecules CD29 (beta 1 integrin) and CD54 (ICAM-1) and GSH. In addition, we also analyzed changes of apoptosis markers such as annexin V binding to membrane and caspase 3 activity in SC-M1 cells after treatment with AMI.

MATERIALS AND METHODS

Changes in CD29, CD54, annexin V binding and GSH levels were examined using FITC-conjugated antibodies or fluorescence probes and flowcytometry. Caspase 3 activity was assayed with spectrofluorometry.

RESULTS

We found that the expression of CD29 and CD54 on SC-M1 was decreased and the caspase 3 activity was increased during the early apoptosis induced by AMI. Moreover, it was found that the GSH content of the cell was depleted within 30 minutes and then recovered.

CONCLUSION

These results suggest that the cell membrane proteins, such as adhesion molecules (CD29, CD54) and intracellular GSH, were the targets of AMI on SC-M1 cells. Since these membrane alterations were prior to apoptosis they may have transduced a death signal to SC-M1 cells.

Profiling the downstream genes of tumor suppressor PTEN in lung cancer cells by complementary DNA microarray

The phosphatase and tensin homology deleted on chromosome 10 (PTEN) is a tumor suppressor gene with sequence homology to tyrosine phosphatases and the cytoskeletal proteins tensin and auxilin. PTEN has recently been shown to inhibit cell migration and the spreading and formation of focal adhesions. This study investigated the role of PTEN in carcinoma invasion in a lung-cancer cell line and examined the downstream genes regulated by PTEN. We have previously established a cell-line model in human lung adenocarcinoma with different invasive abilities and metastatic potentials. Examining PTEN gene expression in these cell lines, we found that a homozygous deletion in exon 5 is associated with high invasive ability. We then constructed stable constitutive and inducible wild-type PTEN-overexpressed transfectants in the highly invasive cell line CL(1-5). We found that an overexpression of PTEN can inhibit invasion in lung cancer cells. To further explore the downstream genes regulated by PTEN, a high-density complementary DNA (cDNA) microarray technique was used to profile gene changes after PTEN overexpression. Our results indicate a panel of genes that can be modulated by PTEN. PTEN overexpression downregulated genes, including integrin alpha(6), laminin beta(3), heparin-binding epidermal growth factor-like growth factor, urokinase-type plasminogen activator, myb protein B, Akt2, and some expressed sequence tag (EST) clones. In contrast, PTEN overexpression upregulated protein phosphatase 2A1B, ubiquitin protease (unph), secreted phosphoprotein 1, leukocyte elastase inhibitor, nuclear factor-kappaB, cyclic adenosine monophosphate response element binding protein, DNA ligase 1, heat shock protein 90, and some EST genes. Northern hybridization and flow cytometry analysis also confirmed that PTEN overexpression results in the reduced expression of the integrin alpha(6) subunit. The results of this study indicate that PTEN overexpression may inhibit lung cancer invasion by downregulation of a panel of genes including integrin alpha(6). The cDNA microarray technique may be an effective tool to study the downstream function of a tumor suppressor gene.

Tumor necrosis factor gene polymorphism and septic shock in surgical infection

OBJECTIVES

To evaluate the relationship of the genotype distribution of the tumor necrosis factor (TNF)-alpha polymorphism with regard to the plasma TNF-alpha concentration and the development of septic shock as well as mortality of infected patients in a surgical intensive care unit (SICU).

DESIGN

A total of 112 postoperative critically ill infected patients were prospectively enrolled.

SETTING

SICU of a tertiary university-affiliated medical center.

PATIENTS

Patients who were consecutively admitted to the SICU because of surgical infection with sepsis.

INTERVENTION

Blood sampling.

MEASUREMENTS AND MAIN RESULTS

Blood sample was obtained 24 hrs after intensive care unit (ICU) admission or within 2 hrs after the onset of septic shock to determine the plasma TNF-alpha level and to analyze the genotype of the biallelic polymorphism of the TNF-alpha.

RESULTS

The allele frequency of the TNF2 in our infected ICU patients was 12%. Forty-two (37.5%) patients admitted fulfilled the criteria of septic shock during their ICU stay. Patients carrying the TNF2 allele were not more likely to develop septic shock, nor did they have a higher mortality rate. In the patients with septic shock, those carrying the TNF2 allele had a significantly higher mortality rate than those with the homozygous TNF1 genotype (92% vs. 62%, p < .05). In those who developed septic shock, the TNF2 allele was significantly associated with higher TNF levels.

CONCLUSION

In patients admitted to SICU with surgical infection, the frequency of TNF2 allele was higher than in the general population. SICU patients with TNF2 allele did not show a higher incidence of developing septic shock, nor was there a higher baseline TNF-alpha level after infection. However, once septic shock had developed, the mortality rate was higher in those patients carrying the TNF2 allele.

Binary/ternary combined effects of vitamin K3 with other antitumor agents in nasopharyngeal carcinoma CG1 cells

Nasopharyngeal carcinoma (NPC) is a prevalent cancer in Taiwan. To improve the treatment of NPC, we have extensively searched for effective combination chemotherapies. Our previous studies indicated that vitamin K3 (VK3) inhibits the growth of NPC CG1 cells in vitro. In this study, we further studied the binary/ternary combined effects of VK3 with other anticancer drugs against NPC cells. The antitumor effects of different VK3 combinations against CG1 cells were determined by using MTT assay, and the combined effects were evaluated by a taibologram, a modified isobolographic method being developed in our laboratory for the analyses of binary/ternary combinations of anticancer agents. Binary combinations of VK3 with doxorubicin (DOX), vinblastine (VBL), or 5-fluorouracil (5-FU) result in synergistic effects. For three-drug combinations, a remarkable synergy was found in the combination of VK3, VBL, and 5-FU. These in vitro results will provide useful information not only for further mechanistic studies and but also for future clinical trials of VK3-based cancer chemotherapy of NPC.

Splenic abscess--a changing trend in treatment

Fifteen patients with splenic abscesses were evaluated between 1985 and 1995. The most common predisposing factors were remote infection, diabetes mellitus and heart disease. Common clinical presentations included leucocytosis, fever, left upper quadrant abdominal pain and left pleural effusion. Four patients with splenic abscesses smaller than 4 cm in diameter were treated with antibiotics alone, and 1 in this treatment group died. Among the 10 patients with splenic abscesses larger than 4 cm in diameter receiving percutaneous drainage, 9 (90%) were successfully cured, including 8 with unilocular abscesses and 1 with multilocular abscesses. Two patients underwent splenectomy. In conclusion, percutaneous drainage using ultrasound or computed tomography guidance may be recommended as the treatment of choice for splenic abscess larger than 4 cm in diameter. Antibiotics alone may sometimes be considered for splenic abscesses smaller than 4 cm in diameter. Splenectomy is reserved for those cases where medical treatment has failed.

Converging evidence from microstimulation, architecture, and connections for multiple motor areas in the frontal and cingulate cortex of prosimian primates

In the present study, somatotopic organization, architectonic features, and patterns of connections were used to define motor areas in the frontal and cingulate cortex of the prosimian primate Galago garnetti. Sites throughout portions of the motor cortex were electrically stimulated with microelectrodes at the approximate depth of layer V. In some of the same animals, injections in primary motor cortex (M1), and in the spinal cord, revealed patterns of connections with physiologically identified motor areas. Results were related to cortical architecture in brain sections processed for Nissl, myelin, cytochrome oxidase, acetylcholinesterase, or neurofilaments. Evidence was obtained for a number of fields previously identified in simian primates, including M1, dorsal premotor field with caudal (PMDc) and rostral (PMDr) divisions, ventral premotor area (PMV), supplementary motor area (SMA), presupplementary motor area (pre-SMA), frontal eye field (FEF), and cingulate motor areas, CMAr and CMAc located rostrally and caudally, respectively. In addition, we distinguished area 6Ds of Preuss and Goldman-Rakic (1991a) between PMV and PMDc, and a more posterior cingulate sensorimotor area (CSMA) with motor connections that may correspond to the supplementary sensory area of monkeys. Areas M1, SMA, PMDc, PMV, CMAr, CMAc, and CSMA projected to the spinal cord, while all of these areas and 6Ds projected to M1. Although area M1 had the lowest stimulation thresholds for evoked movements, movements were also evoked from the other motor areas, as well as from somatosensory areas 3a and 3b. These results indicate that prosimian galagos have a complex of motor areas that closely resembles that in monkeys and suggest that at least 10 motor fields emerged early in primate evolution.