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Carlos Cordon-Cardo

Publications and source records attributed to Carlos Cordon-Cardo.

At least 55 records · Page 3Linked to original sources
PubMed2004

Survival signalling by Akt and eIF4E in oncogenesis and cancer therapy.

Evading apoptosis is considered to be a hallmark of cancer, because mutations in apoptotic regulators invariably accompany tumorigenesis. Many chemotherapeutic agents induce apoptosis, and so disruption of apoptosis during tumour evolution can promote drug resistance. For example, Akt is an apoptotic regulator that is activated in many cancers and may promote drug resistance in vitro. Nevertheless, how Akt disables apoptosis and its contribution to clinical drug resistance are unclear. Using a murine lymphoma model, we show that Akt promotes tumorigenesis and drug resistance by disrupting apoptosis, and that disruption of Akt signalling using the mTOR inhibitor rapamycin reverses chemoresistance in lymphomas expressing Akt, but not in those with other apoptotic defects. eIF4E, a translational regulator that acts downstream of Akt and mTOR, recapitulates Akt's action in tumorigenesis and drug resistance, but is unable to confer sensitivity to rapamycin and chemotherapy. These results establish Akt signalling through mTOR and eIF4E as an important mechanism of oncogenesis and drug resistance in vivo, and reveal how targeting apoptotic programmes can restore drug sensitivity in a genotype-dependent manner.

Animals↗
PubMed2004

Inhibition of orthotopic human bladder tumor growth by lentiviral gene transfer of endostatin.

PURPOSE: Inhibitors of endothelial cell proliferation, such as endostatin, result in suppression of tumor-associated angiogenesis and can achieve growth-inhibitory effects depending on the type of tumor treated. The purpose of this study was to investigate whether local overexpression of endostatin could serve to diminish tumor growth of bladder cancer in vivo. EXPERIMENTAL DESIGN: We examined the capability of lentiviral-mediated gene transfer in vitro and therapeutic effects of lentivirus-based vectors expressing endostatin on tumor growth using an orthotopic human bladder tumor model. RESULTS: We found that self-inactivating lentivirus vectors containing green fluorescent protein, alone or in combination with endostatin, were capable of efficient and stable gene transfer to a variety of human bladder tumor cell lines. The production and secretion of endostatin from lentivirus-transduced KU-7 human bladder cancer cells was confirmed by Western blot and competitive enzyme immunoassay. Intravesical instillation of untransduced, green fluorescent protein control lentivirus-transduced, and endostatin-transduced KU-7 cells was performed in murine models to establish orthotopic tumors. Sustained long-term expression of endostatin was achieved in lentivirus-transduced orthotopic bladder tumors, and it was associated with decreased vascularization and inhibition of tumor growth. Lentivirus vector-mediated overexpression of endostatin did not affect the intrinsic production of basic fibroblast growth factor and vascular endothelial growth factor. CONCLUSIONS: These findings suggest that lentivirus-mediated gene transfer might represent an effective strategy for expression of angioinhibitory peptides to achieve inhibition of human bladder cancer proliferation and tumor progression.

Animals↗
PubMed2004

Loss of the tumor suppressor PML in human cancers of multiple histologic origins.

BACKGROUND: The PML gene is fused to the RARalpha gene in the vast majority of acute promyelocytic leukemias (APL) and has been implicated in the control of key tumor-suppressive pathways. However, its role in the pathogenesis of human cancers other than APL is still unclear. We therefore assessed the status and expression of the PML gene in solid tumors of multiple histologic origins. METHODS: We created tumor tissue microarrays (TTMs) with samples from patients with colon adenocarcinoma (n = 109), lung carcinoma (n = 19), prostate adenocarcinoma (n = 36), breast carcinoma (n = 38), central nervous system (CNS) tumors (n = 51), germ cell tumors (n = 60), thyroid carcinoma (n = 32), adrenal cortical carcinoma (n = 12), and non-Hodgkin's lymphoma (n = 251) and from normal tissue corresponding to each histotype and analyzed PML protein and mRNA expression by immunohistochemistry and in situ hybridization, respectively. Tumor cell lines (n = 64) of various histologic origins were analyzed for PML protein and mRNA expression by immunofluorescence and northern blotting, respectively. DNA from microdissected tumor samples and cell lines was analyzed for PML mutations and loss of heterozygosity (LOH). For some tumor types, the association between PML expression and tumor stage and grade was analyzed. Statistical tests were two-sided. RESULTS: All normal tissues expressed PML protein. PML protein expression was reduced or abolished in prostate adenocarcinomas (63% [95% confidence interval [CI] = 48% to 78%] and 28% [95% CI = 13% to 43%], respectively), colon adenocarcinomas (31% [95% CI = 22% to 40%] and 17% [95% CI = 10% to 24%]), breast carcinomas (21% [95% CI = 8% to 34%] and 31% [95% CI = 16% to 46%]), lung carcinomas (36% [95% CI = 15% to 57%] and 21% [95% = 3% to 39%]), lymphomas (14% [95% CI = 10% to 18%] and 69% [95% CI = 63% to 75%]), CNS tumors (24% [95% CI = 13% to 35%] and 49% [95% CI = 36% to 62%]), and germ cell tumors (36% [95% CI = 24% to 48%] and 48% [95% CI = 36% to 60%]) but not in thyroid or adrenal carcinomas. Loss of PML protein expression was associated with tumor progression in prostate cancer (the progression from prostatic intraepithelial neoplasia to invasive carcinoma was associated with complete PML loss; P<.001), breast cancer (complete PML loss was associated with lymph node metastasis; P =.01), and CNS tumors (complete PML loss was associated with high-grade tumors; P =.003). PML mRNA was expressed in all tumor and cell line samples. The PML gene was rarely mutated and was not subject to LOH. CONCLUSIONS: PML protein expression is frequently lost in human cancers of various histologic origins, and its loss associates with tumor grade and progression in some tumor histotypes.

Adenocarcinoma↗
PubMed2004

Hyperphosphorylation of pRb: a mechanism for RB tumour suppressor pathway inactivation in bladder cancer.

Loss of heterozygosity, mutations or deletions of the RB1 gene usually result in loss of pRb expression, which has been regarded as an indicator of loss of pRb function in human tumours. It has previously been shown that in addition to loss of pRb expression, aberrantly high (pRb2+) pRb expression also indicates loss of pRb function in bladder tumours compared with moderate (normal, pRb1+) pRb expression. The aim of this study was to elucidate the mechanism by which pRb is functionally inactivated in bladder tumours expressing aberrantly high levels of pRb. Constitutive phosphorylation was therefore investigated as a mechanism of pRb inactivation in bladder tumours. Of 28 bladder tumours examined, western blotting demonstrated pRb hyperphosphorylation in 5/7 (71%) pRb2+ bladder tumours compared with only 4/11 (36%) pRb1+ tumours (p = 0.002). All cases with undetectable pRb showed moderate to high p16 expression and none showed cyclin D1 expression by immunohistochemistry. All pRb1+ tumours with underphosphorylated pRb showed p16 but not cyclin D1 expression. All pRb2+ tumours with hyperphosphorylated pRb showed loss of p16 expression and/or cyclin D1 overexpression. Thus, elevated pRb expression was associated with pRb hyperphosphorylation, which, in turn, was associated with loss of p16 expression and/or increased cyclin D1 expression. In order to analyse this association in vitro, T24 cells, which express high levels of pRb, were transfected with p16 cDNA. Transfection with p16 cDNA resulted in a marked decrease in pRb phosphorylation, decreased cell proliferation, and a change in expression of pRb from high to moderate phenotype as assessed by immunohistochemistry. This paper gives the biological basis for constitutive alteration of pRb function in human tumours in the presence of an intact, expressed pRb protein; the mechanism of pRb inactivation is through hyperphosphorylation, which results from loss of p16 expression and/or cyclin D1 overexpression. Immunohistochemical expression of pRb appears to be a reliable indicator of pRb function.

Blotting, Western↗
PubMed2004

Glutathione S-transferase P1 Ile105Val polymorphism, cigarette smoking and prostate cancer.

The enzyme glutathione S-transferase P1 (GSTP1) detoxifies carcinogenic products of tobacco smoke. This exploratory case-control study evaluates the possible effect modification by the GSTP1 Ile105Val polymorphism (replacement of isoleucine by valine at codon 105) on smoking and prostate cancer. Because the Val variant possesses up to a five-fold greater enzymatic activity towards the carcinogenic metabolites of tobacco smoke, the Ile allele is expected to be related to an increase in the risk of prostate cancer among smokers. GSTP1 genotype and epidemiological data were obtained from 122 cases of prostate cancer and 135 healthy males as controls. A logistic regression model was used to estimate odds ratios and 95% confidence intervals. The adjusted OR of homozygous Ile compared to other genotypes for prostate cancer was 1.21 (95% CI: 0.61-2.83). Smoking was not significantly associated with prostate cancer with an adjusted OR of 1.56 (95% CI: 0.78-3.12). However, among individuals with the Ile/Ile genotype, smoking was strongly associated with an increased risk of prostate cancer with an adjusted odds ratio of 4.09 (95% CI: 1.25-13.35). A potential multiplicative interaction was suggested between GSTP1 and smoking on the risk of prostate cancer with the adjusted OR for the interaction of 4.52 (95% CI: 1.07-19.17). To our knowledge, this is the first time that a potential effect modification by the GSTP1 Ile/Ile genotype on smoking and the risk of prostate cancer is suggested.

Adult↗
PubMed2004

Application of new in situ hybridization probes for Ku70 and Ku80 in tissue microarrays of paraffin-embedded malignant melanomas: correlation with immunohistochemical analysis.

Ku70 and Ku80 proteins are responsible for the repair of DNA double-strand breaks and function as a regulatory subunit of the DNA-dependent protein kinase. In this study we analyzed expression of both genes in malignant melanoma tissue arrays applying in situ hybridization probes produced by our research group and using immunohistochemical analysis. Expression of both genes was down-regulated as melanoma progressed. In situ hybridization demonstrated more Ku70- and Ku80-positive cells than immunohistochemical methods, but the correlation between the two methods was highly significant (P <0.01). We conclude that the in situ hybridization assay for the detection of Ku70 and Ku80 expression used in this study is also suitable for tissue microarray analysis of paraffin-embedded melanoma samples. The laboratory procedure is much more complicated than the immunohistochemical method, however.

Adult↗
PubMed2004

Comparison of DNA ploidy status and DNA ploidy-related parameters in malignant melanoma tissue microarrays and full sections.

A new high-throughput tissue-arraying technique, now frequently used in tumor pathology, requires standardization of methods of DNA analysis, previously applied in full histological sections. The main objectives of this study were to evaluate DNA ploidy status and DNA ploidy-related parameters using the CAS200 image analyzer in malignant melanoma tissue microarrays and to compare them with full histological sections. Comparison of DNA ploidy-related parameters, including percentage of diploid cells, percentage of aneuploid cells between 2c and 4c, percentage of tetraploid cells, percentage of aneuploid cells between 4c and 8c, percentage of octaploid cells, percentage of 16-ploid cells, and 5c exceeding rate, did not reveal any significant differences between malignant melanoma tissue microarrays and full sections. The DNA ploidy status according to Auer differed in 1 out of 59 cases investigated. Our study demonstrated that it is possible to evaluate DNA ploidy status and DNA ploidy-related parameters in tissue microarrays, which is of practical relevance to tumor pathology.

Adult↗
PubMed2004

Application of in situ hybridization probes for MLH-1 and MSH-2 in tissue microarrays of paraffin-embedded malignant melanomas: correlation with immunohistochemistry and tumor stage.

Defects in DNA mismatch-repair genes MLH1 and MSH2 reported primarily in hereditary nonpolyposis colorectal carcinoma are present in many sporadic tumors, including malignant melanomas. The main aim of this study was to investigate the expression of these genes in malignant melanomas in relation to tumor stage. An experiment was performed on paraffin-embedded tissue microarrays of malignant melanomas applying in situ hybridization with probes produced by our research group and immunohistochemical techniques. In situ hybridization demonstrated MLH1 expression in 45 of 59 melanomas and MSH2 expression in 51 of 59 melanomas. Immunohistochemistry detected MLH1 expression in 46 of 59 melanomas and MSH2 expression in 50 of 59 melanomas. Down-regulation of expression of both DNA mismatch repair genes in malignant melanomas was observed. The findings obtained by in situ hybridization and immunohistochemistry correlated significantly. Our study demonstrates the suitability of in situ hybridization with MLH1 and MSH2 probes for paraffin-embedded tissue. Tissue microarrays can be used successfully in both in situ hybridization and immunohistochemistry to analyze the expression of DNA mismatch-repair genes.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Analysis of adenomatous polyposis coli gene expression, APC locus-microsatellite instability and APC promoter methylation in the progression of melanocytic tumours.

Adenomatous polyposis coli gene (APC) defects have been demonstrated for the first time in familial adenomatous polyposis. Recent reports indicate that the APC gene is an intermediary between cell adhesion molecules and the cytoskeleton and that it may function as a gatekeeper of colonic epithelial proliferation. The objective of this study was to analyse APC's presence in lentigos, primary melanomas and melanoma metastases. By immunohistochemistry, APC was demonstrated in all lentigos, in 75 out of 88 primary melanomas and in 16 out of 28 melanoma lymphatic metastases. The percentage of immunolabelled tumour cells (APC index) in lentigos ranged between 5 and 69%, in primary melanomas between 0 and 98% and in melanoma metastases between 0 and 52%. Statistically significant differences between lentigos and primary melanomas and between lentigos and metastases in APC expression were found. In a multivariate analysis, APC showed an independent prognostic impact. Analysis of microsatellite instability in the APC locus was performed on 29 melanomas. Microsatellite instability was found in 5/29 melanomas and loss of heterozygosity in 1/29 melanomas. Promoter methylation of APC was found in 6/10 APC-negative primary melanomas and in 9/10 APC-negative melanoma lymphatic metastases investigated. We conclude about important role of APC alterations for melanoma progression.

Adenomatous Polyposis Coli Protein↗
PubMed2004

Genetic and immunophenotype analyses of TP53 in bladder cancer: TP53 alterations are associated with tumor progression.

Altered p53 status is a frequent event in bladder cancer and reported to have prognostic significance. We studied the TP53 gene and its product in 76 patients affected with urinary bladder carcinomas by immunohistochemistry (mAb DO-7), polymerase chain reaction single-strand conformational polymorphism (exons 4-8) followed by direct sequencing of shifted bands, and loss of heterozygosity in 17p (p53CA). H-RAS mutations were also studied. The receiver operating characteristic curve and the logistic-regression analysis were used to evaluate the validity of immunohistochemistry in predicting TP53 mutations. A p53-positive nuclear phenotype was defined by a cutoff of 20% tumor cells being immunoreactive and was found in 23 cases, while TP53 mutations were detected in 22 cases, four of them with a negative p53 phenotype. TP53 deletions were identified in 23 cases. No H-RAS gene mutations were observed. There was a significant association between phenotype and genotype results. Moreover, a significant association was observed between p53 status and tumor stage and grade, being alterations more common in high-stage and high-grade tumors (both chi2 test; P < .01). Deletion of 17p significantly correlated with tumor stage (P < .01) and grade (P = .01), allelic losses being more common in advanced disease. Data from these studies suggest that genetic assays are necessary for the optimal determination of TP53 alterations, mainly in tumors with a p53 negative phenotype, and especially in early stage tumors for which p53 status may assist in determining its progression to invasive disease. Since p53 alterations are significantly associated to clinicopathological features of poor prognosis, the inclusion of both p53 phenotype and TP53 mutation status into a predictive panel of tumor markers for bladder cancer is recommended.

Adult↗
PubMed2004

MDM2 and prognosis.

The cellular stress response pathway regulated by the p53 tumor suppressor is critical to the maintenance of genomic integrity and to the prevention of oncogenic transformation. Intracellular levels of p53 are tightly regulated by an autoregulatory feedback loop comprised of p53 and MDM2. It might be predicted that disruption of this loop, either through p53 mutation or overexpression of MDM2, would be a negative prognostic marker for cancer development, likelihood of relapse, or response to therapy. In fact, although MDM2 overexpression is common in cancer, it can be both a positive and a negative predictor of outcome in different tumors, and its significance as a biomarker remains controversial. Data from a number of different tumor types are reviewed for the predictive significance of MDM2 expression, along with evidence for different mechanisms of MDM2 overexpression in these different tumors. In light of the biological complexities underlying the p53-MDM2 loop, it is, perhaps, not surprising that no simple paradigm exists that is generally applicable. Much work remains to be done to elucidate the basic mechanisms underlying the physical interactions between the two proteins, the role of protein modifications in altering those interactions, and also the genetic and transcriptional deregulations by which protein levels are altered in human cancers. Only in this way will truly biologically relevant predictive factors emerge.

Animals↗
PubMed2004

Decreased retinoid X receptor-alpha protein expression in basal cells occurs in the early stage of human prostate cancer development.

The development of prostatic intraepithelial neoplasia (PIN)-like lesions in the prostate-specific retinoid X receptor-alpha (RXRalpha) null mouse suggests that RXRalpha may protect against neoplasia. The purpose of this study was to characterize RXRalpha protein expression in human prostate to determine if RXRalpha is altered in early stages of tumor progression. Immunohistochemistry with anti-RXRalpha antibody was performed on 138 fresh frozen prostate specimens collected from 27 noncarcinomatous prostates and 111 radical prostatectomy samples of prostate adenocarcinoma (CA). The RXRalpha signal intensity was scored using a scale of 0-3. In normal glands, RXRalpha was expressed strongly in basal cells and only weakly in secretory epithelial cells. This finding was confirmed by double immunofluorescence labeling of RXRalpha and Keratin-903, a basal cell marker, followed by confocal microscopic examination. In basal cells, a gradual decrease of RXRalpha expression was noted from normal glands of noncarcinomatous prostate (3.0 +/- 0) to "normal" glands distant to CA (2.13 +/- 0.44) to "normal" glands adjacent to CA (1.25 +/- 0.53) and high-grade PIN (0.56 +/- 0.58). While nearly all "normal" glands from 138 specimens were positive for RXRalpha in basal cells, only 48% (13 of 27) of the high-grade PIN glands appeared positive. Moreover, basal cell expression of RXRalpha in "normal" tissue was less in specimens with poorly differentiated tumor (Gleason score >/= 8; 1.83 +/- 0.36) compared with well-differentiated tumor (Gleason score < 6; 2.35 +/- 0.34; P = 0.04). Thus, a decrease of RXRalpha in the basal cells may serve as a marker for prostate CA-associated field change, which may represent an early event in the prostate carcinogenic process. These findings suggest that chemoprevention strategies with retinoids may be most effective if applied during the early stages of transformation.

Adenocarcinoma↗
PubMed2004

Preclinical validation of anti-TMEFF2-auristatin E-conjugated antibodies in the treatment of prostate cancer.

Current treatments for advanced stage, hormone-resistant prostate cancer are largely ineffective, leading to high patient mortality and morbidity. To fulfill this unmet medical need, we used global gene expression profiling to identify new potential antibody-drug conjugate (ADC) targets that showed maximal prostate cancer-specific expression. TMEFF2, a gene encoding a plasma membrane protein with two follistatin-like domains and one epidermal growth factor-like domain, had limited normal tissue distribution and was highly overexpressed in prostate cancer. Immunohistochemistry analysis using a specific monoclonal antibody (mAb) to human TMEFF2 showed significant protein expression in 74% of primary prostate cancers and 42% of metastatic lesions from lymph nodes and bone that represented both hormone-naïve and hormone-resistant disease. To evaluate anti-TMEFF2 mAbs as potential ADCs, one mAb was conjugated to the cytotoxic agent auristatin E via a cathepsin B-sensitive valine-citrulline linker. This ADC, Pr1-vcMMAE, was used to treat male severe combined immunodeficient mice bearing xenografted LNCaP and CWR22 prostate cancers expressing TMEFF2. Doses of 3 to 10 mg/kg of this specific ADC resulted in significant and sustained tumor growth inhibition, whereas an isotype control ADC had no significant effect. Similar efficacy and specificity was shown with huPr1-vcMMAE, a humanized anti-TMEFF2 ADC. No overt in vivo toxicity was observed with either murine or human ADC, despite significant cross-reactivity of anti-TMEFF2 mAb with the murine TMEFF2 protein, implying minimal toxicity to other body tissues. These data support the further evaluation and clinical testing of huPr1-vcMMAE as a novel therapeutic for the treatment of metastatic and hormone-resistant prostate cancer.

Amino Acid Sequence↗
PubMed2003

Mutations of the PML tumor suppressor gene in acute promyelocytic leukemia.

The promyelocytic leukemia (PML) tumor suppressor of acute promyelocytic leukemia (APL) is essential for a number of proapoptotic and growth-suppressive pathways as well as for the activity of differentiating agents such as retinoic acid (RA). In human APL, the dose of PML is reduced to heterozygosity given that one allele is involved in the chromosomal translocation while the status of the remaining PML allele is unknown. We have therefore used single-strand conformational polymorphism (SSCP) and sequencing analysis to screen DNA from APL patients for mutations at the PML locus. We identified DNA sequence variations resulting in a truncated PML protein in APL cases that displayed RA resistance and a very poor prognosis. Mutation analysis also led to the identification of aberrant PML sequence variations in other hematopoietic malignancies. Complete functional loss of PML is therefore selected by the APL phenotype and associates with poor prognosis and RA unresponsiveness.

Animals↗
PubMed2003

p73 Expression in human normal and tumor tissues: loss of p73alpha expression is associated with tumor progression in bladder cancer.

PURPOSE: To characterize the expression profile of p73 in human normal tissues by immunohistochemistry (IHC) and to analyze the correlation between p73 expression and bladder cancer progression. EXPERIMENTAL DESIGN: CJDp73 was characterized for p73alpha detection in Western blot and IHC through its application to isoform-transfected 293 cells. Normal tissues were analyzed by IHC with the CJDp73 antiserum. Transitional cell carcinoma (TCC)-derived cell lines were subjected to reverse transcription-PCR and Western blot. TCC tissue microarrays were analyzed for p73alpha expression by IHC, and the results were statistically analyzed. RESULTS: p73 immunostaining was nuclear and restricted to epithelial cells of certain organs such as squamous epithelium of the epidermis and transitional epithelium of the bladder. The expression was also observed in certain specialized glandular epithelia such as acinar cells of breast and parotid gland. Four of seven TCC-derived cell lines had low to undetectable p73alpha protein levels. We found undetectable or low p73alpha expression in 104 of 154 (68%) TCC cases, this phenotype being more frequently observed in invasive tumors when compared with superficial lesions. This association was statistically significant (P < 0.0001). We also observed a significant association between p53, p63, and p73alpha alterations with bladder cancer progression (P < 0.0001). CONCLUSIONS: p73alpha plays a tumor suppressor role in bladder cancer, and its inactivation occurs through an epigenetic mechanism, most probably involving protein degradation.

Cell Line↗
PubMed2003

Pten dose dictates cancer progression in the prostate.

Complete inactivation of the PTEN tumor suppressor gene is extremely common in advanced cancer, including prostate cancer (CaP). However, one PTEN allele is already lost in the vast majority of CaPs at presentation. To determine the consequence of PTEN dose variations on cancer progression, we have generated by homologous recombination a hypomorphic Pten mouse mutant series with decreasing Pten activity: Pten(hy/+) > Pten(+/-) > Pten(hy/-) (mutants in which we have rescued the embryonic lethality due to complete Pten inactivation) > Pten prostate conditional knockout (Pten(pc)) mutants. In addition, we have generated and comparatively analyzed two distinct Pten(pc) mutants in which Pten is inactivated focally or throughout the entire prostatic epithelium. We find that the extent of Pten inactivation dictate in an exquisite dose-dependent fashion CaP progression, its incidence, latency, and biology. The dose of Pten affects key downstream targets such as Akt, p27(Kip1), mTOR, and FOXO3. Our results provide conclusive genetic support for the notion that PTEN is haploinsufficient in tumor suppression and that its dose is a key determinant in cancer progression.

Alleles↗