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Massimo Loda

Publications and source records attributed to Massimo Loda.

At least 73 records · Page 4Linked to original sources
PubMed2003

Elevated serum periostin levels in patients with bone metastases from breast but not lung cancer.

Periostin is a recently identified gene that is preferentially expressed in periosteum, indicating a potential role in bone formation and maintenance of structure. We independently identified and isolated periostin from cancer tissue, using the palindromic PCR-driven cDNA Differential Display technique. For the present work, we developed a novel sandwich chemiluminescence assay to detect serum periostin level using newly developed monoclonal and polyclonal antibodies. We investigated serum periostin levels in breast cancer and small cell lung cancer patients, especially in patients with bone metastasis. The study included 58 breast cancer and 44 small cell lung cancer patients. Serum periostin levels were elevated in breast cancer patients presenting with bone metastases (92.0 +/- 28.6 ng/ml) compared to similar breast cancer patients without evidence of bone metastasis (55.0 +/- 16.6 ng/ml, p = 0.04). No correlation was found between the serum periostin level and any other prognostic factors, such as clinical stage and lymph node metastasis in breast cancer. Serum periostin levels thus appear to serve as a marker of bone metastasis from breast cancer. In contrast, serum periostin levels were similar in samples from patients with small cell lung cancer who did or did not have bone metastasis. However, increasing T-stage and N-stage of patients with small cell lung cancer were correlated with higher periostin levels (T4, 126.5 +/- 29.7 ng/ml v.s. T2, 64.9 +/- 16.1 ng/ml, p = 0.03; and T4 v.s. T1, 36.3+/- 7.5 ng/ml, p = 0.01; N3, 108.7 +/- 17.3 ng/ml v.s. N2, 49.7+/- 10.9 ng/ml, p = 0.01). Periostin has a substantial homology with the insect cell adhesion molecule, fasciclin I. Thus, expression of periostin may facilitate tumor cell adhesion to the bone surface. In fact, we found by in situ RNA hybridization, that the periostin gene was highly expressed in the stromal cells immediately surrounding the tumor, but not within the breast cancer cells themselves.

Adult↗
PubMed2003

Reciprocal Cdc25A and p27 expression in B-cell non-Hodgkin lymphomas.

Cell cycle regulation is often altered in cancer and deregulation of the cell cycle checkpoints is common in human neoplasia. The dual-specificity phosphatase Cdc25A and the cell cycle inhibitor p27 both play an important role in the regulation of the G1-S transition. We evaluated Cdc25A mRNA expression by in situ hybridization and p27 protein expression by immunohistochemistry in 42 histologically indolent B-cell non-Hodgkin lymphoma (NHL and 51 histologically aggressive B-cell NHL. Overexpression of Cdc25A (>50% tumor cells positive) was detected in 5 of 42 cases (12%) of histologically indolent B-cell NHL and in 29 of 51 (57%) of histologically aggressive B-cell NHL (P < 0.001). In contrast, high p27 protein expression (>50% tumor cells positive) was observed in 29 (69%) cases of indolent but in only one case (2%) of aggressive B-cell NHL (P < 0.0001). Thus, overexpression of Cdc25A and concomitant loss of p27 expression are associated with high grade B-cell NHL and may contribute to their aggressive biologic behavior.

Cell Count↗
PubMed2003

p27 and cyclin E/D2 associations in testicular germ cell tumors: implications for tumorigenesis.

The cyclins are key regulators of cell cycle progression and cellular proliferation. We have previously shown that in testicular germ cell tumors, cyclin E expression correlates with more aggressive tumors, higher clinical stage, and the presence of pulmonary metastases. Here, we have examined the association between cyclin activation and the proliferative rate of the pluripotential testicular tumor cell. We have shown that in a panel of 30 testicular germ cell tumors, 15 cases (50%) expressed the cyclin dependent kinase inhibitor p27; of note, 13 of 14 embryonal carcinomas (93%) coexpressed cyclin E and p27, suggesting inhibition of this cyclin. We show that 25 of 30 (83%) of the testicular germ cell tumors express cyclin D2. Using immunoprecipitation assays from the embryonal carcinoma cell line NTera2 or from tumor cell extracts, we have shown that cyclin D2 is complexed with p27, consistent with its known ability to sequester and block the cyclin E inhibitory function of p27. From these results, we propose a model in testicular germ cell tumors, in particular embryonal carcinomas, whereby the overexpression of cyclin D2, a gene localized on chromosome 12p--a region of DNA amplification in germ cell tumors--leads to the functional sequestration of p27 in the presence of cyclin E and cyclin D2, thus favoring cellular proliferation.

Biopsy↗
PubMed2003

Sensitivity of non-small-cell lung cancer cell lines established from patients treated with prolonged infusions of Paclitaxel.

OBJECTIVE: Regimens with prolonged infusions of taxanes have been developed for patients with cancer to overcome drug resistance. Our objective of the present study was to examine the impact of prolonged exposure on the cytotoxicity of taxanes against non-small-cell lung carcinoma (NSCLC) cell lines and the clinical response and outcome of the patients. METHODS: Five cell lines (NCI-H2882, -H2887, -H2973, -H3122, -H3255) were derived from previously untreated patients with NSCLC who participated in clinical trials of continuous 96-hour infusions of paclitaxel followed by bolus cisplatin. Two additional cell lines (NCI-H838, -H1299) with previously published data were used as controls. Drug sensitivities were assessed by the MTS (Promega) assay. Multidrug resistance (MDR) phenotypes were assessed by quantitative real-time PCR and HER-2/NEU by both immunohistochemistry and ELISA. RESULTS: The median of mean IC(50) values of docetaxel at the exposure durations of 3, 24, 72 and 120 h were 0.52, 0.06, 0.03 and 0.06 microM, respectively. The median of mean IC(50) values of paclitaxel at the exposure duration of 3, 24, 72 and 120 h were 0.48, 0.13, 0.03 and 0.02 microM, respectively. In all cell lines studied, there was a less than 4-fold difference in the IC(50) values between docetaxel and paclitaxel at 3-, 72-, and 120-hour exposure times. The single cell line with moderate MDR1 expression (NCI-H2887) was the only cell line established from a patient with progressive disease when treated with paclitaxel. CONCLUSIONS: This study demonstrates prolonged exposure to both docetaxel and paclitaxel inhibits the growth of NSCLC cell lines in similar fashion.

Adult↗
PubMed2003

Fatty acid synthase expression defines distinct molecular signatures in prostate cancer.

The androgen-regulated enzyme fatty acid synthase (FAS), required for de novo lipogenesis, is overexpressed in several cancers including prostate carcinoma and has been associated with aggressive disease. FAS expression was assessed in 81 prostate carcinomas, both by immunohistochemistry in tissue microarrays and by Affymetrix Hu95Av2 oligonucleotide arrays. Both FAS mRNA and protein were significantly overexpressed in prostate carcinomas compared with the corresponding normal tissue. FAS mRNA and protein expression increased substantially from normal to prostatic intraepithelial neoplasia, to low grade, to high grade, and to androgen-independent bone metastases. A significant correlation between FAS mRNA and protein expression was found in two thirds of the cases. In 17% of the cases, FAS protein levels were high despite low mRNA levels, and these tumors exhibited a distinct molecular signature when compared with tumors that did not express FAS protein. Whereas the latter group of tumors expressed some proapoptotic genes, tumors with high FAS levels overexpressed, among other genes, its transcriptional regulator, steroid regulator binding protein, and apolipoprotein E. These data demonstrate (1) the consistent overexpression of FAS in prostate carcinoma compared with the adjacent normal tissue, (2) a strong association between FAS and prostate tumor initiation and progression, (3) the highest FAS expression occurring in androgen-independent bone metastases, (4) the transcriptional and posttranscriptional regulation of FAS in the majority and in a subset of prostate cancers, respectively, and (5) most importantly, the identification by FAS expression of prostate tumors with unique molecular signatures and potentially diverse biologic behavior.

Androgens↗
PubMed2003

Heregulin targets gamma-catenin to the nucleolus by a mechanism dependent on the DF3/MUC1 oncoprotein.

The DF3/MUC1 transmembrane oncoprotein is aberrantly overexpressed in most human breast carcinomas and interacts with the Wnt effector gamma-catenin. Here, we demonstrate that MUC1 associates constitutively with ErbB2 in human breast cancer cells and that treatment with heregulin/neuregulin-1 (HRG) increases the formation of MUC1-ErbB2 complexes. The importance of the MUC1-ErbB2 interaction is supported by the demonstration that HRG induces binding of MUC1 and gamma-catenin and targeting of the MUC1-gamma-catenin complex to the nucleolus. Significantly, nucleolar localization of gamma-catenin in response to HRG is dependent on MUC1 expression. Moreover, mutation of a RRK motif in the MUC1 cytoplasmic domain abrogates HRG-induced nucleolar localization of MUC1 and gamma-catenin. In concert with these results, we show nucleolar localization of MUC1 and gamma-catenin in human breast carcinomas but not in normal mammary ductal epithelium. These findings demonstrate that MUC1 functions in cross talk between ErbB2 and Wnt pathways by acting as a shuttle for HRG-induced nucleolar targeting of gamma-catenin.

Active Transport, Cell Nucleus↗
PubMed2002

The role of the ubiquitination-proteasome pathway in breast cancer: use of mouse models for analyzing ubiquitination processes.

Turnover of several regulatory proteins results from targeted destruction via ubiquitination and subsequent degradation through the proteosome. The timely and irreversible degradation of critical regulators is essential for normal cellular function. The precise biochemical mechanisms that are involved in protein turnover by ubiquitin-mediated degradation have been elucidated using in vitro assays and cell culture systems. However, pathways that lead to ubiquitination of critical regulatory proteins in vivo are more complex, and have both temporal and tissue-specific differences. In vivo models will allow identification of substrates and enzymes of the ubiquitin-proteosome pathway that play important roles in selected tissues and diseases. In addition, assessment of the therapeutic efficacy of drugs designed to inhibit or enhance protein turnover by ubiquitination requires in vivo models. In the present review we describe selected examples of transgenic and knockout models of proteins that are known either to be regulated by ubiquitin-mediated degradation or to have a catalytic function in this process, and to play an important role in breast cancer. We outline the functions of these proteins in vivo and focus on knowledge gained in the comparison of in vivo behavior predicted from cell-free in vitro data or from experiments conducted in cell culture systems.

Animals↗
PubMed2002

Loss of the Lkb1 tumour suppressor provokes intestinal polyposis but resistance to transformation.

Germline mutations in LKB1 (also known as STK11) are associated with Peutz-Jeghers syndrome (PJS), a disorder with predisposition to gastrointestinal polyposis and cancer. PJS polyps are unusual neoplasms characterized by marked epithelial and stromal overgrowth but have limited malignant potential. Here we show that Lkb1(+/-) mice develop intestinal polyps identical to those seen in individuals affected with PJS. Consistent with this in vivo tumour suppressor function, Lkb1 deficiency prevents culture-induced senescence without loss of Ink4a/Arf or p53. Despite compromised mortality, Lkb1(-/-) mouse embryonic fibroblasts show resistance to transformation by activated Ha-Ras either alone or with immortalizing oncogenes. This phenotype is in agreement with the paucity of mutations in Ras seen in PJS polyps and suggests that loss of Lkb1 function as an early neoplastic event renders cells resistant to subsequent oncogene-induced transformation. In addition, the Lkb1 transcriptome shows modulation of factors linked to angiogenesis, extracellular matrix remodelling, cell adhesion and inhibition of Ras transformation. Together, our data rationalize several features of PJS polyposis--notably its peculiar histopathological presentation and limited malignant potential--and place Lkb1 in a distinct class of tumour suppressors.

AMP-Activated Protein Kinases↗
PubMed2002

A hereditary nonpolyposis colorectal carcinoma case associated with hypermethylation of the MLH1 gene in normal tissue and loss of heterozygosity of the unmethylated allele in the resulting microsatellite instability-high tumor.

Fourteen suspected hereditary nonpolyposis colorectal carcinoma cases with microsatellite unstable(microsatellite instability-high; MSI-H) tumors but no germ-line MSH2, MSH6, or MLH1 mutations were examined for hypermethylation of CpG sites in the critical promoter region of MLH1. The methylation patterns were determined using methylation-specific PCR and by sequence analysis of sodium bisulfite-treated genomic DNA. In one case, DNA hypermethylation of one allele was detected in DNA isolated from blood. In the MSI-H tumor from this case, the unmethylated MLH1 allele was eliminated by loss of heterozygosity, and the methylated allele was retained. This biallelic inactivation resulted in loss of expression of MLH1 in the tumor as confirmed by immunohistochemistry. These results suggest a novel mode of germ-line inactivation of a cancer susceptibility gene.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Molecular cloning and characterization of STAMP1, a highly prostate-specific six transmembrane protein that is overexpressed in prostate cancer.

We have identified a novel gene, six transmembrane protein of prostate 1 (STAMP1), which is largely specific to prostate for expression and is predicted to code for a 490-amino acid six transmembrane protein. Using a form of STAMP1 labeled with green fluorescent protein in quantitative time-lapse and immunofluorescence confocal microscopy, we show that STAMP1 is localized to the Golgi complex, predominantly to the trans-Golgi network, and to the plasma membrane. STAMP1 also localizes to vesicular tubular structures in the cytosol and colocalizes with the early endosome antigen 1 (EEA1), suggesting that it may be involved in the secretory/endocytic pathways. STAMP1 is highly expressed in the androgen-sensitive, androgen receptor-positive prostate cancer cell line LNCaP, but not in androgen receptor-negative prostate cancer cell lines PC-3 and DU145. Furthermore, STAMP1 expression is significantly lower in the androgen-dependent human prostate xenograft CWR22 compared with the relapsed derivative CWR22R, suggesting that its expression may be deregulated during prostate cancer progression. Consistent with this notion, in situ analysis of human prostate cancer specimens indicated that STAMP1 is expressed exclusively in the epithelial cells of the prostate and its expression is significantly increased in prostate tumors compared with normal glands. Taken together, these data suggest that STAMP1 may have an important role in the normal prostate cell as well as in prostate cancer progression.

Amino Acid Sequence↗
PubMed2002

Evaluation of microsatellite instability and immunohistochemistry for the prediction of germ-line MSH2 and MLH1 mutations in hereditary nonpolyposis colon cancer families.

Forty-eight hereditary nonpolyposis colorectal carcinoma (HNPCC) families for which a tumor sample was available were evaluated for the presence of germ-line mutations in MSH2 and MLH1, tumor microsatellite instability (MSI), and where possible, expression of MSH2 and MLH1 in tumors by immunohistochemistry. Fourteen of 48 of the families had a germ-line mutation in either MSH2 or MLH1 that could be detected by genomic DNA sequencing, and 28 of 48 of the families had MSI-H tumors. Four additional families showed loss of expression of MSH2, and one additional family showed loss of expression of MLH1 but did not have germ-line mutations in MSH2 or MLH1 that could be detected by DNA sequencing. MSI-H, as defined using the National Cancer Institute recommended five-microsatellite panel, had a 100% sensitivity for identifying samples having MSH2 or MLH1 mutations or loss of expression. In contrast, loss of MSH2 and MLH1 expression did not identify all samples having germ-line mutations in MSH2 or MLH1, because in five cases, a mutant protein product was expressed that could be detected by IHC. A combination of the Bethesda criteria for HNPCC and an MSI-H phenotype defined the smallest number of cases having all of the germ-line MSH2 and MLH1 mutations that could be detected by DNA sequencing.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Growth factor requirements and basal phenotype of an immortalized mammary epithelial cell line.

Carcinogenesis involves a multistep process whereby a normal healthy cell undergoes both immortalization and oncogenesis to become fully transformed. Immortalization results from the subversion of critical cell cycle regulatory checkpoints, thereby allowing a cell to extend its finite life span and to maintain telomeric length. Oncogenesis is the manifestation of additional genetic events that are capable of conferring upon the cell an actual growth advantage. Such an advantage may relieve a cell of its normal requirements for a particular growth factor or may enhance the ability of a cell to proliferate outside of its normal microenvironment. To further investigate this multistep process, we developed an immortalized mammary epithelial cell line by overexpressing the catalytic subunit of telomerase (human telomerase reverse transcriptase) in primary human mammary epithelial cell lines. We present evidence that the overexpression of human telomerase reverse transcriptase was sufficient to extend the life span of the cells and allow for additional events that lead to immortalization. The result was the establishment of an IMEC line. Biochemical analysis of these cells indicates a basal epithelial phenotype with expression of high molecular weight cytokeratins. We show that continued growth of the IMECs is rigorously dependent upon both insulin and epidermal growth factor, and that the mitogenic effects of these factors on the IMECs are mediated in part by AKT. In addition, IMECs express the p53 family member DeltaN-p63-alpha, which is found in basal epithelial cells of many tissues and has been implicated as playing an essential role in normal epithelial development. Our studies suggest that the immortalization of basal epithelial cells of the mammary gland may be an early step in the initiation of a subset of breast cancers with a basal epithelial phenotype.

Breast↗
PubMed2002

Gene expression correlates of clinical prostate cancer behavior.

Prostate tumors are among the most heterogeneous of cancers, both histologically and clinically. Microarray expression analysis was used to determine whether global biological differences underlie common pathological features of prostate cancer and to identify genes that might anticipate the clinical behavior of this disease. While no expression correlates of age, serum prostate specific antigen (PSA), and measures of local invasion were found, a set of genes was identified that strongly correlated with the state of tumor differentiation as measured by Gleason score. Moreover, a model using gene expression data alone accurately predicted patient outcome following prostatectomy. These results support the notion that the clinical behavior of prostate cancer is linked to underlying gene expression differences that are detectable at the time of diagnosis.

Adult↗
PubMed2002

Gene transcript quantitation by real-time RT-PCR in cells selected by immunohistochemistry-laser capture microdissection.

Studying tissue-based gene expression in different cell populations often requires immunohistochemistry-guided microdissection. However, mRNA degradation occurs during long staining procedures. We combined a novel rapid immunoperoxidase technique with laser capture microdissection (LCM) and real-time quantitative RT-PCR to compare p27 mRNA expression in prostatic basal/secretory cells. Eight frozen prostate sections were immunostained with antibody 34betaE12 (high-molecular-weight keratin). Secretory and basal cells were separately collected by LCM. p27 transcripts from each cell group were quantitated by real-time RT-PCR, with GAPDH as standard. Immunostaining took 22 minutes, with RNA extraction from approximately 40 dissected cells from each compartment initiated within 40 minutes. Qualitative RT-PCR gave a product of the expected size from each sample. Quantitative RT-PCR gave basal/secretory p27/GAPDH ratios of 0.99-16.24 (mean 5.53 +/- 0.643). Immunostaining for keratin 34betaE12 can be done on frozen sections in approximately 20 minutes, and mRNA from pure cell populations can be quantitated by RT-PCR. We used this technique to show that p27 transcript levels are greater in basal than in secretory prostate cells, suggesting, when combined with prior studies, that regulation of p27 occurs at the protein level in normal cells. This technique may have wide applicability to studies of gene expression in distinct cell populations in heterogeneous tissues.

Dissection↗
PubMed2002

Expression of p27 and VHL in renal tumors.

Renal tumors, in particular clear cell renal cell carcinomas, have an unclear prognosis and metastatic potential. Cell cycle regulators play a key role in cellular proliferation and have been implicated in neoplasia. The cell cycle inhibitor p27 has been associated with prognosis in various tumor types. Recently a reported association between p27 and Von Hippel-Lindau (VHL) gene function has also been noted. We have examined p27 and VHL expression by immunohistochemistry in a panel of kidney tumors and have noted specific and unique patterns of p27 expression in various tumor types. In addition, we have analyzed p27 expression in clear cell type renal cell carcinomas and have noted a significant association between decreasing p27 expression and increasing tumor size, suggesting a relation between renal cell proliferation and loss of p27 function. These findings suggest a role for p27 in the development of various types of renal tumors.

Adenoma, Oxyphilic↗
PubMed2002

Diagnostic utility of immunohistochemical staining for p63, a sensitive marker of prostatic basal cells.

Diagnostically reliable identification of prostatic basal cells has depended on staining for high molecular weight cytokeratin. The diagnosis of malignancy is often based on the absence of basal cells. False-negative staining is occasionally observed. Thus, a second method of identifying basal cells might prove useful. Selective expression of p63, a homologue of p53, has been demonstrated in prostatic basal cells. We investigated the diagnostic utility of p63 staining in 70 consecutive specimens for which the differential diagnosis included prostatic adenocarcinoma: 68 needle biopsies and 2 transurethral resection blocks. High molecular weight cytokeratin staining was the gold standard when material was available. A total of 61 specimens were diagnosed as carcinoma, 4 as atrophy, 2 as high-grade prostatic intraepithelial neoplasia, 2 as unclassified collections of benign glands, and 1 as carcinoma versus high-grade prostatic intraepithelial neoplasia. Sections mounted on charged slides were used for p63 staining for 14 specimens. Sections previously hematoxylin and eosin stained on uncharged slides were used for 56 specimens. In every case in which there was successful p63 staining (55 specimens), basal cells in benign lesions were properly marked and other cell types were not stained. Uninformative staining in the remaining 15 specimens was due to failure of tissue adherence in 14 specimens in which sections were on uncharged slides and, in 1 specimen, to poor positive internal control staining of benign glands. Thus, p63 staining was informative in 55 of 56 specimens (98%) for which there was material for examination. No case with satisfactory p63 and high molecular weight staining showed disagreement between the two stains. An additional group of 21 transurethral resection specimens was stained (p63 and high molecular weight cytokeratin). There was less false-negative staining for p63 compared with the case of high molecular weight cytokeratin. No false-positive staining was seen. We conclude that p63 staining is at least as sensitive and specific for the identification of basal cells in diagnostic prostate specimens as is high molecular weight cytokeratin staining.

Adenocarcinoma↗
PubMed2002

Obligate roles for p16(Ink4a) and p19(Arf)-p53 in the suppression of murine pancreatic neoplasia.

Epithelial tumors of the pancreas exhibit a wide spectrum of histologies with varying propensities for metastasis and tissue invasion. The histogenic relationship among these tumor types is not well established; moreover, the specific role of genetic lesions in the progression of these malignancies is largely undefined. Transgenic mice with ectopic expression of transforming growth factor alpha (TGF-alpha) in the pancreatic acinar cells develop tubular metaplasia, a potential premalignant lesion of the pancreatic ductal epithelium. To evaluate the cooperative interactions between TGF-alpha and signature mutations in pancreatic tumor genesis and progression, TGFalpha transgenic mice were crossed onto Ink4a/Arf and/or p53 mutant backgrounds. These compound mutant mice developed a novel pancreatic neoplasm, serous cystadenoma (SCA), presenting as large epithelial tumors bearing conspicuous gross and histological resemblances to their human counterpart. TGFalpha animals heterozygous for both the Ink4a/Arf and the p53 mutation showed a dramatically increased incidence of SCA, indicating synergistic interaction of these alleles. Inactivation of p16(Ink4a) by loss of heterozygosity, intragenic mutation, or promoter hypermethylation was a common feature in these SCAs, and correspondingly, none of the tumors expressed wild-type p16(Ink4a). All tumors sustained loss of p53 or Arf, generally in a mutually exclusive fashion. The tumor incidence data and molecular profiles establish a pathogenic role for the dual inactivation of p16(Ink4a) and p19(Arf)-p53 in the development of SCA in mice, demonstrating that p16(Ink4a) is a murine tumor suppressor. This genetically defined model provides insights into the molecular pathogenesis of SCA and serves as a platform for dissection of cell-specific programs of epithelial tumor suppression.

Animals↗