Relevance of proliferative and pro-apoptotic factors in non-small-cell lung cancer for patient survival

Bioinformatic Identification of Hub Genes and Analysis of Prognostic Values in Colorectal Cancer

The purpose of this study is to discover novel hub genes which are helpful for diagnosis, prognosis, and targeted therapy in colorectal cancer (CRC) by using bioinformatics analysis. GSE74602, GSE110225, and GSE113513 were extracted from the gene expression omnibus (GEO). Differentially expressed genes (DEGs) in expression profiles were identified by GEO2R. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses of the DEGs were carried out in the Database for Annotation, Visualization, and Integrated Discovery (DAVID). String database and cytoscape were used for building protein-protein interaction (PPI) network and module analysis. The UALCAN was used for in-depth analysis of data of CRC patients from The Cancer Genome Atlas (TCGA) to identify expression levels and overall survival rates of hub genes. The DEGs included 107 up-regulation genes and 232 down-regulation genes. Twenty-nine (29) hub genes and two significant modules were screened from PPI network. The expression levels of hub genes in TCGA were verified. Survival analysis curve indicated high expression of CCNA2, CCNB1, DLGAP5, were related to high survival rates, and low expression of TIMP1 were associated with high survival rates. These results suggest that DEGs may be the hub genes of CRC, and CCNA2, CCNB1, DLGAP5, TIMP1 may be the potential prognostic markers of CRC.

The Histone Deacetylase Inhibitor Entinostat/Syndax 275 in Osteosarcoma

The prognosis for metastatic osteosarcoma (OS) is poor and has not changed in several decades. Therapeutic paradigms that target and exploit novel molecular pathways are desperately needed. Recent preclinical data suggests that modulation of the Fas/FasL pathway may offer benefit in the treatment of refractory osteosarcoma. Fas and FasL are complimentary receptor-ligand proteins. Fas is expressed in multiple tissues, whereas FasL is restricted to privilege organs, such as the lung. Fas expression has been shown to inversely correlate with the metastatic potential of OS cells; tumor cells which express high levels of Fas have decreased metastatic potential and the ones that reach the lung undergo cell death upon interaction with constitutive FasL in the lung. Agents such as gemcitabine and the HDAC inhibitor, entinostat/Syndax 275, have been shown to upregulate Fas expression on OS cells, potentially leading to decreased OS pulmonary metastasis and improved outcome. Clinical trials are in development to evaluate this combination as a potential treatment option for patients with refractory OS.

Decoding molecular mechanism of inhibitor bindings to CDK2 using molecular dynamics simulations and binding free energy calculations

CDK2 can be used as an attractive target for development of efficient inhibitors curing multiple disease relating with CDK2. In this work, molecular dynamics (MD) simulations and binding free energy calculations were coupled to probe conformational changes of CDK2 due to inhibitor associations and binding mechanisms of inhibitors PM1, FMD and X64 to CDK2. The results suggest that the binding strength of FMD and X64 to CDK2 is stronger than that of PM1. Principal component (PC) analysis and cross-correlation map calculations based on the equilibrated MD trajectories demonstrate that the structural difference in inhibitors exerts important impact on motion modes and dynamics behavior of CDK2. Residue-based free energy decomposition method was adopted to estimate the inhibitor-residue spectrum. The results not only efficiently identify the hot interaction spot of inhibitors with CDK2 but also show that the hydrophobic rings R1, R2 and R3 as well as polar groups of three inhibitors play key roles in favorably binding of inhibitors to CDK2. This work is expected to contribute energetic basis and dynamics information to development of promising inhibitors toward CDK2.Communicated by Ramaswamy H. Sarma.

Expression and prognostic relevance of STAT3 and cyclin D1 in non-small cell lung cancer

Aim

To guide clinicians in selecting treatment options for patients with non-small cell lung cancer (NSCLC), it is desirable to have reliable markers predicting clinical outcome. This study analyzed the correlation between signal transducer and activator of transcription 3 (STAT3) and cyclin D1 in NSCLC and their association with clinicopathological features and survival.

Methods

We investigated 65 specimens of NSCLC tissues by immunohistochemistry using STAT3 and cyclin D1 antibodies. First we determined the correlation between STAT3 and cyclin D1 expression and the clinicopathological features of the tumor. Then we assessed the prognostic relevance of STAT3 and cyclin D1.

Results

A significant correlation was found between high levels of STAT3 expression and the degree of tumor differentiation. Additionally, a significant positive correlation was found between the expression of STAT3 and cyclin D1 (r=0.405, p=0.001). The overexpression of STAT3 and the presence of metastasis were significantly associated with shorter overall survival in univariate analysis (p=0.028 and p=0.036, respectively). Multivariate analysis confirmed that STAT3 expression was an independent prognostic factor (p=0.001).

Conclusions

STAT3 might be correlated with tumor differentiation, and its elevated expression may be an adverse prognostic indicator for patients with NSCLC. Activation of the STAT3/cyclin D1 signaling pathway may be attributed to the malignant transformation of NSCLC and may represent a possible target for therapy.

Prognostic markers in lung cancer: is it ready for prime time?

Non-small cell lung cancer (NSCLC) is a heterogeneity disease and to date, specific clinical factors and tumor stage are established as prognostic markers. Nevertheless, prognosis within stage may vary significantly. During the last 3 decades, genes/proteins that drive tumor initiation and progression, such as oncogenes and tumor suppressor genes have been studied as additional potential prognostic markers. The protein markers as evaluated by immunohistochemistry (IHC) have previously dominated these studies. However, with the development of high-throughput techniques to interrogate genome wide genetic or gene expression changes, DNA (copy number and mutation) and RNA (mRNA and microRNA) based markers have more recently been studied as prognostic markers. Largely due to the heterogeneity and complexity of NSCLC, single gene markers including KRAS mutation has not been validated as strong prognostic markers. In contrast, several gene expression signatures representing mRNA levels of multiple genes have been developed and validated in multiple microarray datasets of independent patient cohorts. The salient features of these gene signatures and their potential value to predict benefit from adjuvant chemotherapy is discussed.

Identification of HLA ligands and T-cell epitopes for immunotherapy of lung cancer

INTRODUCTION

Lung cancer is the most common cancer worldwide. Every year, as many people die of lung cancer as of breast, colon and rectum cancers combined. Because most patients are being diagnosed in advanced, not resectable stages and therefore have a poor prognosis, there is an urgent need for alternative therapies. Since it has been demonstrated that a high number of tumor- and stromal-infiltrating cytotoxic T cells (CTLs) is associated with an increased disease-specific survival in lung cancer patients, it can be assumed that immunotherapy, e.g. peptide vaccines that are able to induce a CTL response against the tumor, might be a promising approach.

METHODS

We analyzed surgically resected lung cancer tissues with respect to HLA class I- and II-presented peptides and gene expression profiles, aiming at the identification of (novel) tumor antigens. In addition, we tested the ability of HLA ligands derived from such antigens to generate a CTL response in healthy donors.

RESULTS

Among 170 HLA ligands characterized, we were able to identify several potential targets for specific CTL recognition and to generate CD8+ T cells which were specific for peptides derived from cyclin D1 or protein-kinase, DNA-activated, catalytic polypeptide and lysed tumor cells loaded with peptide.

CONCLUSIONS

This is the first molecular analysis of HLA class I and II ligands ex vivo from human lung cancer tissues which reveals known and novel tumor antigens able to elicit a CTL response.

FAS/FASL expression profile as a prognostic marker in squamous cell carcinoma of the oral cavity

FAS/FASL altered expression may cause tumor protecting immunomodulation, with a direct impact on patient prognosis. FAS expression was studied in 60 squamous cell carcinomas of the oral cavity. FAS expression did not show a significant association with tumor histopathological characteristics, but was significantly associated with lymph node positivity. FAS expression was significantly associated with disease specific death and negative FAS expression was an independent risk factor, increasing risk 4 times when compared to positive expression. When FAS and FASL expression results were combined, we were able to define high, intermediate and low risk profiles. Disease-free and disease-specific survival were significantly correlated with FAS/FASL expression profiles. The high risk category was an independent marker for earlier disease relapse and disease-specific death, with approximately 4- and 6-fold increased risk, respectively, when compared to the low risk profile. Risk profiles based on FAS/FASL expression showed that high risk was significantly associated with increased disease relapse and death, as well as shorter disease-free or disease-specific survival. This categorization, added to patient clinical data, may facilitate the choice of therapy, minimizing treatment failure and increasing disease control.

Prognostic assessment of apoptotic gene polymorphisms in non-small cell lung cancer in Chinese

Apoptosis plays a key role in inhibiting tumor growth, progression and resistance to anti-tumor therapy. We hypothesized that genetic variants in apoptotic genes may affect the prognosis of lung cancer. To test this hypothesis, we selected 38 potentially functional single nucleotide polymorphisms (SNPs) from 12 genes (BAX, BCL2, BID, CASP3, CASP6, CASP7, CASP8, CASP9, CASP10, FAS, FASLG and MCL1) involved in apoptosis to assess their prognostic significance in lung cancer in a Chinese case cohort with 568 non-small cell lung cancer (NSCLC) patients. Thirty-five SNPs passing quality control underwent association analyses, 11 of which were shown to be significantly associated with NSCLC survival (P < 0.05). After Cox stepwise regression analyses, 3 SNPs were independently associated with the outcome of NSCLC (BID rs8190315: P = 0.003; CASP9 rs4645981: P = 0.007 and FAS rs1800682: P = 0.016). A favorable survival of NSCLC was significantly associated with the genotypes of BID rs8190315 AG/GG (adjusted HR = 0.65, 95% CI: 0.49-0.88), CASP9 rs4645981 AA (HR = 0.22, 95% CI: 0.07-0.69) and FAS rs1800682 GG (adjusted HR = 0.67, 95% CI: 0.46-0.97). Time-dependent receptor operation curve (ROC) analysis revealed that the area under curve (AUC) at year 5 was significantly increased from 0.762 to 0.819 after adding the risk score of these 3 SNPs to the clinical risk score. The remaining 32 SNPs were not significantly associated with NSCLC prognosis after adjustment for these 3 SNPs. These findings indicate that BID rs8190315, CASP9 rs4645981 and FAS rs1800682 polymorphisms in the apoptotic pathway may be involved in the prognosis of NSCLC in the Chinese population.

Lipid metabolic pathways as lung cancer therapeutic targets: a computational study

Inhibitors of lipid metabolic pathways, particularly drugs targeting the mevalonate pathway, have been suggested to be valuable in enhancing the effectiveness of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and these compounds may also be effective in patients with inherent or acquired resistance to EGFR-TKIs. The present study examined gene expression profiles in lung adenocarcinoma to characterize the interaction between growth factor signals and lipid metabolic pathways at the transcriptional level. Gene expression correlation analysis showed that genes involved in the mevalonate pathway and unsaturated fatty acid synthesis were negatively correlated with the expression of EGFR, MET and other growth factor receptor genes, as well as with the expression of genes involved in cell migration and adhesion. On the other hand, the expression of genes related to cell cycle progression, DNA repair and DNA replication were positively correlated with the metabolic pathway genes mentioned above, and a significant number of such genes had promoter domains for nuclear factor Y (NFY). Genes whose expression showed a positive correlation with NFY expression and mevalonate pathway genes were found to exhibit protein-protein interactions with several 'hub' genes, including BRCA1, that have been associated with both lung cancer and cell division. These results support the idea that inhibition of lipid metabolic pathways may be valuable as an alternative therapeutic option for the treatment of lung adenocarcinoma, and suggest that NFY is a possible molecular target for such efforts.

Assessment of promising protein markers for vulva cancer

OBJECTIVES

To validate the results of a previous study with the tissue microarray technology showing that cyclooxygenase 2 (COX-2) overexpression and absent caspase 3 expression are associated with poor disease-specific survival in univariate analysis.

METHODS

The study group comprised 80 consecutive patients with vulva cancer treated in the period from 1999 to 2003 in a university hospital. A tissue microarray with 3 tumor tissue cores per patient was constructed and stained with antibodies against COX-2, caspase 3, epidermal growth factor receptor, p16 INK4, cyclin D1, and Ki-67. The impact of the expression of these protein markers and selected clinicopathologic variables on disease-specific as well as disease-free survival was measured. Cox proportional hazard model was used for both univariate and multivariate analyses.

RESULTS

In multivariate analysis, lymph node metastases and strong COX-2 expression were related to disease-free (hazard ratio [HR], 8.33, 95% confidence interval [CI], 2.97-23.36; P < 0.001; and HR, 6.42; 95% CI, 2.33-17.72; P < 0.001) and disease-specific survival (HR, 6.04; 95% CI, 2.12-17.19; P = 0.001; and HR, 5.11; 95% CI, 1.82-14.36; P = 0.002). In the present series, no association was found between caspase 3 expression and survival.

CONCLUSION

The prognostic significance of COX-2 overexpression was confirmed. In contrast, in the present series, no relation was found between caspase 3 expression and survival.

Immunohistochemical markers associated with brain metastases in patients with nonsmall cell lung carcinoma

BACKGROUND

To the authors' knowledge, there are no reliable markers able to identify patients with nonsmall cell lung cancer (NSCLC) that will develop metastases to the brain. The authors investigated associations between immunohistochemical markers and the development of brain metastases in patients with NSCLC.

METHODS

This was a hospital-based, case-control study of patients who were newly diagnosed with NSCLC between 1989 and 2003, developed brain metastases, and had pathology material available from both the primary NSCLC and the brain metastases. These patients were compared with a control group of patients who had NSCLC and no evidence of brain metastases. NSCLC was examined for expression levels of Ki-67, caspase-3, vascular endothelial growth factor A (VEGF-A), VEGF-C, E-cadherin, and epidermal growth factor receptor (EGFR) in 54 surgical pathology specimens using immunohistochemistry, and associations were evaluated between those markers and the development of brain metastases.

RESULTS

Brain metastases developed after a median of 12.5 months (range, 1.7-89.4 months) after the diagnosis of NSCLC. A significantly increased risk of developing brain metastases was associated with patients with NSCLC who had primary tumors with high Ki-67 levels (adjusted odds ratio [OR] of 12.2; 95% confidence interval [95% CI], 2.4-70.4 [P < .001]), low caspase-3 expression (adjusted OR of 43; 95% CI, 5.3 to >100 [P < .001]), high VEGF-C expression (adjusted OR of 14.6; 95% CI, 2.0 to >100 [P < .001]), and low E-cadherin (adjusted OR of 3.6; 95% CI, 0.9-16.4 [P = .05]). No significant risk was associated with VEGF-A or EGFR expression. High Ki-67 expression also was associated with a shorter overall survival (P = .04).

CONCLUSIONS

The results of the current study indicated that patients with NSCLC who had high Ki-67 expression, low caspase-3 expression, high VEGF-C expression, and low E-cadherin expression in their tumors may benefit from close surveillance because they may have an increased risk of developing brain metastases.

Identification of polymorphisms in the Caspase-3 gene and their association with lung cancer risk

Caspase-3 (CASP-3) is a primary effector CASP that executes programmed cell death, and it plays an important role in the development and progression of cancer. Polymorphisms in the CASP-3 gene may influence CASP-3 production and/or activity, thereby modulating the susceptibility to lung cancer. To test this hypothesis, we first screened for polymorphisms in the CASP-3 gene by direct sequencing of genomic DNA samples from 27 healthy Koreans, and then evaluated their associations with lung cancer in a case-control study that consisted of 582 lung cancer patients and 582 healthy controls. Individuals with at least one variant allele of the -928A > G, 77G > A, and 17532A > C polymorphisms were at a significantly decreased risk for lung cancer in comparison to the carriers with each homozygous wild-type allele [adjusted odds ratio (OR) = 0.79, 95% confidence interval (CI) = 0.62-1.00, P = 0.05; adjusted OR = 0.78, 95% CI = 0.61-0.99, P = 0.04; and adjusted OR = 0.74, 95% CI = 0.58-0.95, P = 0.02, respectively]. Consistent with the results of genotyping analysis, the GAGC haplotype carrying the variant allele at all of the -928A > G, 77G > A, and 17532A > C loci was associated with a significantly decreased risk of lung cancer compared to the AGGA haplotype carrying no variant alleles at the three loci (adjusted OR = 0.66, 95% CI = 0.51-0.86, P = 0.002 and Bonferroni corrected P = 0.008). These results suggest that the CASP-3 polymorphisms and their haplotypes contribute to the genetic susceptibility to lung cancer.

Prognostic value of fluorine-18 fluorodeoxyglucose positron emission tomography imaging in patients with advanced-stage non-small-cell lung carcinoma

PURPOSE

To determine whether the amount of fluorine-18 fluorodeoxyglucose (FDG) uptake in the primary lung cancer on positron emission tomography (PET) imaging at the time of presentation has prognostic significance in patients with advanced-stage non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A retrospective review identified 214 patients with advanced-stage NSCLC (stage IIIA, IIIB, and IV) who underwent FDG PET study at the time of diagnosis. Extensive clinical data, including tumor histologic cell type, pathologic stage at presentation, and treatment, were recorded. The maximum standardized uptake value (SUV(max)) in the primary tumor on FDG PET on survival was examined using Cox proportional hazards regression.

RESULTS

One hundred fifty-eight (74%) of the 214 patients died and 56 patients were reported alive at 27 months (range, 3 to 140 months) after the diagnosis of NSCLC. Using the median SUV(max) of 11.1, the patient population was subdivided. The median survival of the 106 patients with the primary tumor having an SUV(max) less than 11.1 was 16 months (95% CI, 12 to 21 months), whereas the median survival of the 108 patients with the primary tumor having an SUV(max) > or = 11.1 was 12 months (95% CI, 10 to 15 months). Univariate and multivariate analysis did not provide evidence that survival for patient subgroups defined by the median SUV(max) were significantly different (univariate P = .11; multivariate P = .45).

CONCLUSION

FDG uptake of the primary lesions in patients with a new diagnosis of advanced-stage NSCLC does not have a significant relationship with survival.

Intratumoral CRH modulates immuno-escape of ovarian cancer cells through FasL regulation

Although corticotropin-releasing hormone (CRH) and Fas ligand (FasL) have been documented in ovarian carcinoma, a clear association with tumour progression and immuno-escape has not been established. FasL plays an important role in promoting tumour cells' ability to counterattack immune cells. Here, we examined immunohistochemically the expression of CRH, CRHR1, CRHR2 and FasL in 47 human ovarian cancer cases. The ovarian cancer cell lines OvCa3 and A2780 were further used to test the hypothesis that CRH might contribute to the immune privilege of ovarian tumours, by modulating FasL expression on the cancer cells. We found that CRH, CRHR1, CRHR2 and FasL were expressed in 68.1, 70.2, 63.8 and 63.8% of the cases respectively. Positivity for CRH or FasL expression was associated with higher tumour stage. Finally, CRH increased the expression of FasL in OvCa3 and A2780 cells through CRHR1 thereby potentiated their ability to induce apoptosis of activated peripheral blood lymphocytes. Corticotropin-releasing hormone produced by human ovarian cancer might favour survival and progression of the tumour by promoting its immune privilege. These findings support the hypothesis that CRHR1 antagonists could potentially be used against ovarian cancer.

Immunohistochemical markers of prognosis in non-small cell lung cancer: a review and proposal for a multiphase approach to marker evaluation

Characteristics of the tumour that affect and predict the survival outcome of patients with cancer are prognostic markers for cancer. In non-small cell lung carcinoma (NSCLC), stage is the main determinant of prognosis and the basis for deciding options for treatment. Patients with early-stage tumour are treated by complete surgical resection, which is curative in 40-70% of patients. That there are other factors important in determining the biology of these tumours, especially genes that have a role in metastasis, is indicated. Such factors could potentially be used to further classify patients into groups according to substages that may be treated differently. During the past decade, a large number of proteins that are putatively important in carcinogenesis and cancer biology have been studied for their prognostic value in NSCLC, but none of them have been proved to be sufficiently useful in clinical diagnosis. Several markers (epidermal growth factor receptor, human epidermal growth factor receptor 2, Ki-67, p53 and Bcl-2) have been studied exhaustively. Ki-67, p53 and Bcl-2 are suggested to be important but weak prognostic markers, by meta-analyses of the results. Cyclin E, vascular endothelial growth factor A, p16(INK4A), p27(kip1) and beta-catenin are promising candidates, but require further study in large randomised clinical trial samples by using standardised assays and scoring systems. Some issues and inconsistencies in the reported studies to date are highlighted and discussed. A guideline for a multi-phase approach for conducting future studies on prognostic immunohistochemistry markers is proposed here.

Regulation of the G1/S phase of the cell cycle and alterations in the RB pathway in human lung cancer

The retinoblastoma (RB)-Cyclin (CCN)D1-p16 cell cycle pathway has a crucial role in lung tumorigenesis. Impairment of the RB pathway has been shown to occur in almost all lung tumors. A deregulation at any level of this core RB pathway seems to make cells insensitive to the mitogenic signaling that is required for cell cycle progression. To date, almost all participants in this pathway have been shown to be altered to a various degree in lung tumors. Some of the alterations are mutually exclusive, including RB and p16INK4A . In small cell lung cancer, the RB tumor suppressor gene is inactivated in almost 90% of the tumors, whereas in non-small cell lung cancer, the cyclin-dependent kinase (CDK)4 inhibitor p16INK4A is inactivated in 40-60% of the tumors. Many mechanisms may be responsible for activating the RB-Cyclin D1 pathway, including activating (CDK4) and inactivating mutations (p16INK4A ), deletions (RB and p16INK4A ), amplifications (CCND1 and CDK4), silencing methylation (p16INK4A and RB), and hyper-phosphorylation (RB). As some of these alterations, such as p16INK4A methylation, can also be detected in bronchial lavage and serum, they could potentially serve as useful markers for the early detection of lung cancer. This review summarizes recent experiments describing the variable roles of key-player molecules of the RB pathway and different mechanisms by which the RB pathway can be altered in lung cancer.

A critical appraisal of prognostic and predictive factors for common lung cancers

The outlook for patients with lung cancer remains poor despite advances in the understanding of the pathology and biology of this disease. To optimize treatment protocols prognostic data are essential. The current era with molecular research on mRNA expression analysis and proteomics will lead to a plethora of new molecular markers, which are likely to be correlated, at least in part, with each other and with disease activity, progression and survival. However, although the number of prognostic factors analysed in published systematic reviews on lung cancer is large, the scope of these factors in individual studies is often narrow. In daily practice prognostic factors other than general TNM staging are not implemented. To assess the efficacy of new prognostic factors for the management of individual patients with non-small cell lung cancer, studies with clinically relevant modelling are required. In this review arguments are provided to use a model combining radiological and histopathological growth rate, histopathological diagnosis and molecular characteristics as markers for metastatic capacity, tumour volume doubling time and expected response to targeted therapy. This may reveal time-related predictive information useful for treatment guidance of the individual patient.

Prognostic value of cyclin D1 overexpression in correlation with pRb and p53 status in non-small cell lung cancer (NSCLC)

PURPOSE

The aim of this study was to assess the impact of cyclin D1 overexpression (considered separately or jointly with previously assessed p53 and pRb statuses) on survival in a group of 111 surgically treated non-small cell lung cancer patients (NSCLC).

METHODS

Cyclin D1 accumulation was assessed immunohistochemically, with the use of monoclonal antibody (DCS-6, DakoCytomation) and the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique.

RESULTS

Overexpression of cyclin D1 was found in 55 samples (49%), whereas the altered phenotypes cyclin D1+/p53+ or cyclin D1+/pRb- were found in 23 (22%) and 9 samples (9%), respectively. Statistical analysis was performed for different cut-off values and the only significant differences were found if samples with some expression of each protein were considered positive. There was no relationship between cyclin D1 overexpression and major clinicopathological factors, including p53 expression; however, there was a direct correlation between cyclin D1 and pRb protein expression (p=0.007). Cyclin D1 accumulation did not influence patients' survival. Of all possible cyclin D1/p53, cyclin D1/pRb and cyclin D1/p53/pRb phenotypes, patients with cyclin D1-/p53+ phenotype had shortened overall survival compared to other patients (p=0.027, HR=1.8). In the multivariate analysis, the only variable associated with shortened overall and disease-free survival was the stage of disease (p<0.001).

CONCLUSIONS

These results suggest the lack of prognostic value of cyclin D1 overexpression in NSCLC patients.

Aminoimidazo[1,2-a]pyridines as a new structural class of cyclin-dependent kinase inhibitors. Part 1: Design, synthesis, and biological evaluation

We have identified a novel structural class of protein serine/threonine kinase inhibitors comprised of an aminoimidazo[1,2-a]pyridine nucleus. Compounds from this family are shown to potently inhibit cyclin-dependent kinases by competing with ATP for binding to a catalytic subunit of the protein. Structure-based design approach was used to direct this chemical scaffold toward generating potent and selective CDK2 inhibitors. The discovery of this new class of ATP-site directed protein kinase inhibitors, aminoimidazo[1,2-a]pyridines, provides the basis of new medicinal chemistry tool in search for an effective treatment of cancer and other diseases that involve protein kinase signaling pathways.

Prognostic implications of Fas-ligand expression in nasopharyngeal carcinoma

BACKGROUND

In nasopharyngeal carcinoma (NPC), Fas-ligand (Fas-L)-mediated apoptosis might contribute to the immune privilege of tumors. In some cancers, dysregulation of Fas-L protein in tumors might lead to disease progression. The purpose of this study was to evaluate the correlations between Fas-L expression and the clinical outcomes in patients with NPC.

METHODS

We recruited 78 patients with primary NPC, classified clinical stages according to the 1997 American Joint Committee on Cancer staging system, and assessed Fas-L with immunohistochemical methods.

RESULTS

Forty-one (53%) of 78 patients were Fas-L-positive. The prevalence was 0%, 57%, 58%, and 82% from stages I to IV, respectively (p <.001). Fas-L expression was associated with the N classification (p=.05) but not the T classification. Patients with positive Fas-L expression had a lower rate of disease-free survival and overall survival (p=.01 for all log-rank tests).

CONCLUSION

Patients with NPC with Fas-L-positive tumors had higher clinical stages and lymph node metastasis at diagnosis and poorer disease-free survival and overall survival; therefore, Fas-L expression may be a potential biomarker of prognosis.

Expression of caspase-3 and c-myc in non-small cell lung cancer

PURPOSE

Caspase-3 is a cysteine protease that plays an important role in the process of apoptotic cell death, but little has been studied clinically on caspase-3 in lung cancer. Increased c-myc expression can result in mitosis or apoptosis, and its contribution to the pathogenesis and prognosis of lung cancer has gained interest. In the present study, the expressions of caspase-3 and c-myc, along with their possible correlations with prognostic variables, were analyzed in resected non-small cell lung carcinomas (NSCLC).

MATERIALS AND METHODS

Archival tumor tissues from 147 previously untreated NSCLC patients were examined by immunohistochemistry for the expressions of caspase-3 and c-myc proteins. Clinical information was obtained through the computerized retrospective database from the tumor registry.

RESULTS

The expressions of caspase-3 and c-myc were detected in 60 (88/147) and 16% (24/147) of tumors, respectively. No association was found between caspase-3 and c-myc expressions. A multivariate analysis demonstrated the N status and pathologic stage to be significantly correlated with poor survival (p-value=.018 and .002, respectively), but positive expression of caspase-3 was associated with a good prognosis (p=.03).

CONCLUSION

Our data suggest the involvement of caspase-3 in the tumorigenesis of NSCLC. It is also noteworthy that caspase-3 expression might be a favorable prognostic indicator in these tumors.

pRB2/p130 target genes in non-small lung cancer cells identified by microarray analysis

The retinoblastoma gene family consisting of RB/p105, p107, and RB2/p130 cooperate to regulate cell-cycle progression through the G1 phase of the cell cycle. Previous data demonstrated an independent role for the reduction or loss of pRb2/p130 expression in the formation and/or progression of lung carcinoma. Rb2/p130 is mutated in a human cell line of lung small cell carcinoma as well as in primary lung tumors. To identify potential pRb2/p130 target genes in an unbiased manner, we have utilized an adenovirus-mediated expression system of pRb2/p130 in a non-small lung cancer cell line to identify specific genes that are regulated by pRb2/p130. Using oligonucleotide arrays, a number of Rb2/p130 downregulated genes were identified and their regulation was confirmed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. As a result, 40 genes showed greater than 2.0-fold modification in their expression level after the RB2/p130 viral transduction. In conclusion, coupling adenoviral overexpression with microarray and semiquantitative RT-PCR analyses proved to be a versatile strategy for identifying pRb2/p130 target genes and for better understanding the expression profiles of these genes. Our results may also contribute to identifying novel therapeutic biomarkers in lung carcinoma.

Prognostic relevance of Fas (APO-1/CD95) ligand in human colorectal cancer

OBJECTIVE

Fas ligand (FasL) is an important mediator of immune function and induces apoptosis by binding to its receptor Fas on sensitized cells. It has recently been shown that malignancies may express FasL and acquire immune privilege by inducing apoptosis of lymphocytes. Acquired resistance to Fas mediated apoptosis is known to be an early event in carcinogenesis. The aim of this study was to determine the extent of FasL expression in patients with colorectal cancer and examine its relationship with several prognostic pathological features and survival.

DESIGN AND METHODS

Sixty-eight patients (median age 66 years) with colorectal cancer, whose diagnosis was made between 1988 and 1991 and in whom long-term follow-up was available, were evaluated. The tumours were of varying stages at diagnosis (eight Dukes' A, 28 Dukes' B, 23 Dukes' C and nine Dukes' D). The expression of FasL was detected immunohistochemically with a rabbit polyclonal IgG using the DAKO EnVision+ System. The specificity of FasL binding was confirmed by pre-incubation of the antibody with the immunizing peptide prior to staining. The relationship with several pathological features was determined using Kendall's tau-b correlation. Overall survival was estimated using the Kaplan-Meier product limit curves. Differences in observed survival were tested for statistical significance using the Mantel-Haenszel log rank test. Both the extent and intensity of staining were graded by a blinded observer.

RESULTS

FasL was predominantly expressed in tumour epithelial cells in 88% of the cases. The positive staining of tumours varied in extent. FasL staining was higher in earlier Dukes' stage tumours in that the extent of FasL staining negatively correlated with Dukes' stage (Kendall tau-b = -0.22, P = 0.038). Consistent with this, the overall survival was better with a greater extent of FasL expression (log rank chi2 = 5.68, P = 0.017). There was a lower extent of FasL expression in mucinous adenocarcinomas (Kendall tau-b = 0.288, P = 0.01) and in those tumours with neural invasion (Kendall tau-b = -0.26, P = 0.03). No relationship was detected between FasL and tumour site, size, margin, differentiation, vascular invasion, necrosis or Crohn's-like reaction.

CONCLUSIONS

FasL is widely expressed in colorectal cancers. This finding suggests that the extent of FasL expression in colorectal tumours is directly related to patients' survival.

Infiltrating immune cells, but not tumour cells, express FasL in non-small cell lung cancer: No association with prognosis identified in 3-year follow-up

Non-small cell lung cancer (NSCLC) remains a difficult disease to treat and independent prognostic markers other than tumour stage and histology have not emerged. The immune cell content of solid tumours has been associated with tumour regression and at times, tumour progression. The involvement of immune cells in prognosis of NSCLC is poorly described. Poor immune responses within solid tumours have been linked with tumour production of immunosuppressive cytokines. Tumour expression of FasL is thought to disarm responses through the transduction of a death signal in Fas-expressing T cells. The existence of the 'tumour counterattack' in vivo has been questioned. We undertook to measure T cell and macrophage infiltration of the tumour bed in NSCLC and report the association between immune cell content and prognosis in a limited, 3-year analysis of survival (n = 113). In addition we investigated FasL expression (n = 45). T cells and macrophages were found to frequently infiltrate lung tumours, albeit in small numbers. Generally there were more T cells infiltrating than macrophages. T cell and macrophage numbers were not associated with prognosis. Lung tumours were found not to express FasL, although occasional immune cells surrounding tumour cells were strongly positive. FasL expression was not associated with prognosis in this series. Thus, immune cells infiltrating NSCLC are not capable of suppressing tumour growth, nor are they associated with tumour progression. We report that lung tumours do not express the FasL, and that although some immune cells are FasL positive, this is not a reflection of general immune cell activation.

Differentially expressed genes associated with mouse lung tumor progression

To detect altered gene expression associated with mouse lung tumor progression, we compared the gene expression profile of lung adenocarcinomas with that of lung adenomas and normal lungs. Autoradiographic analysis showed that among the 588 genes surveyed, 152 genes were detected and the remaining 436 genes did not give any signals. A gene-specific semiquantitative reverse transcription polymerase chain reaction method was used to confirm the expression profile. A total of 29 genes was found to be differentially expressed in mouse lung tumors when compared to normal lungs. The pattern of expression, either underexpression or overexpression, was the same for 10 genes between adenocarcinomas and adenomas. Among them, seven genes were overexpressed, two genes were underexpressed and one gene was lost. Interestingly, 19 genes showed differential expression or increased incidence or difference in level of change between lung adenomas and adenocarcinomas, including Stat1, ADAP, IGFBP-6, PDGF-A, TGF-beta2, Int-3, VEGFR2, BAX, BAG-1, c-Jun, FasL, TRAIL, YB-1, CD31, Cdc42, B-raf, Rab-2, Abi-1, and ACE. These genes can be designated as candidate 'lung tumor progression' (LTP) genes because their expression changes may specifically affect lung tumor progression in mice. Further analyses of these candidate LTP genes may provide new leads for elucidation of lung tumor progression in mice.

Differential regulation of hydrogen peroxide and Fas-dependent apoptosis pathways by dehydroascorbate, the oxidized form of vitamin C

Dehydroascorbate (DHA), the oxidized form of vitamin C (ascorbate), enhanced antioxidant defenses of human T cells preferentially importing DHA over ascorbate. In itself, DHA did not affect cytosolic or mitochondrial reactive oxygen intermediate levels as monitored by flow cytometry using oxidation-sensitive fluorescent probes. DHA at 200-1,000 microM stimulated activity of pentose phosphate pathway enzymes glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and transaldolase, elevated intracellular glutathione levels, and inhibited H(2)O(2)-induced changes in mitochondrial transmembrane potential and cell death. With respect to the CD4 antigen, DHA selectively enhanced cell-surface expression of the Fas receptor and increased susceptibility of Jurkat and H9 human T cells to Fas-mediated cell death. The data identify DHA as a selective regulator of H(2)O(2)- and Fas-dependent apoptosis pathways.

Immune privilege or inflammation? Insights into the Fas ligand enigma

Fas ligand (FasL) has become an enigmatic molecule: some evidence indicates that it contributes to immune privilege in tissues and tumors, whereas other data demonstrates that FasL can elicit inflammation. New findings may begin to reconcile the paradoxical effects of FasL.