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W J Mooi

Publications and source records attributed to W J Mooi.

At least 19 recordsLinked to original sources
PubMed1995

Comparative analysis of p53 gene mutations and protein accumulation in human non-small-cell lung cancer.

A series of 54 resected primary non-small-cell lung carcinomas was analyzed for p53 gene mutations and for p53 protein accumulation and the findings were correlated with clinical parameters. Mutations in exons 5 through 8 of the p53 gene were identified by a denaturing gradient gel electrophoresis (DGGE) assay and cycle sequencing, whereas p53 protein accumulation was detected in paraffin-embedded tissue by immunostaining using 2 different murine monoclonal antibodies (MAbs) (BP53-12 and DO7). A p53 gene mutation and/or p53 protein accumulation was found in 37 of 54 tumors. Mis-sense mutations were closely associated with positive immunostaining, which was intense in 15 out of 17 cases with a mutation. In 10 tumors, obvious p53 accumulation was detected in the absence of mutations in exons 5 through 8. Conversely, only one of 8 p53 non-sense mutations led to detectable p53 accumulation. The most frequent single base changes were G --> T transversions and C --> T transitions. The presence of a p53 alteration was not related to age, tumor size, stage or histology. However, we found a significant inverse correlation between p53 alterations and the presence of a K-ras mutation. This was reflected in the overall postoperative survival data: patients with p53 alterations in their tumors tended to have a better prognosis than those without a p53 alteration; however, this difference was lost when cases with a K-ras mutation were omitted from the analysis.

Adult↗
PubMed1995

Radioimmunotherapy of small-cell lung cancer xenografts using 131I-labelled anti-NCAM monoclonal antibody 123C3.

We have studied the therapeutic efficacy of 131I-labelled monoclonal antibody 123C3 in human small-cell lung carcinoma xenografts established from the NCI-H69 cell line in nude mice. Several radiation doses were administered intraperitoneally and different treatment schedules were tested. The maximal tolerated dose, 2 x 500 microCi, resulted in complete remission of tumours smaller than 200 mm3 and long-lasting remission (more than 135 days) of the larger tumours. In control experiments, treatment with unlabelled monoclonal antibody 123C3 did not affect the tumour growth rate, while the effect of radiolabelled non-relevant, isotype-matched, monoclonal antibody M6/1 was minor and transient. Regrowth of the tumours occurred in all cases and could not be attributed to loss of neural cell adhesion molecule (NCAM) expression. Tumour recurrence is probably caused by insufficient radiation dosage. Radiation-induced toxicity was monitored by assessment of weight and bone marrow examination. Weight loss was observed in all treatment groups, but the mice regained their initial weight within 14 days, except for the group receiving the highest radiation dose (3 x 600 microCi). In this group all mice died as a result of radiotoxicity. Of the mice injected with 600 microCi radiolabelled control antibody, 50% died within 2 weeks after administration. Apparently the higher uptake of the radiolabelled monoclonal antibody in the tumour reduced systemic radiation toxicity.

Animals↗
PubMed1995

Prognostic factors in NSCLC. Recent experiences.

In recent years, a group of new prognostic factors have been added to the list of well-known clinical prognostic factors of non-small cell lung cancer. Among these are mutations in the K-ras oncogene, abnormalities in p53, the presence of N-CAM expression as measured by Mab immunostaining and elevated serum levels of NSE. These factors have provided important clinical insights into the biology of lung cancer and prospective studies using these biomarkers are now warranted to provide further important clues about their potential significance in treatment selection of patients.

Biomarkers, Tumor↗
PubMed1994

Intraperitoneal photodynamic therapy in the rat: comparison of toxicity profiles for photofrin and MTHPC.

Toxicity studies for intraperitoneal photodynamic therapy (IPPDT) were performed in Wag/RijA rats, using specially designed light delivery blocks for proper light distribution and light dosimetry. A recently developed photosensitizer mesotetrahydroxyphenylchlorin (mTHPC), excited at 652-nm wave-length, was compared with Photofrin (630 nm). Toxicity profiles for various sensitizer doses, light fluences and time intervals were investigated. A light fluence of 15 J.cm-2 delivered to the entire peritoneum 24 hr after 5 mg Photofrin per kg i.v. induced reversible impairment of intestinal, liver and kidney function. A dose of 0.2 mg mTHPC per kg i.v. followed by 6 J.cm-2 at 72 hr appeared to be equitoxic to the intestines; however, functional tests revealed little effect for this mTHPC-mediated IPPDT regime on liver or kidney. Histology demonstrated focal irreversible damage to the kidneys for both photosensitizers, not reflected in functional impairment. Light doses of 25 to 30 J.cm-2 at 24 hr after Photofrin or 8-12 J.cm-2, 72 hr after mTHPC caused lethal toxicity in the first 2 weeks due to intestinal damage. Higher light doses caused a shock syndrome and rhabdomyolysis resulting in death within 20 hr for both photosensitizers. In conclusion, maximum tolerable schedules for whole-abdomen IPPDT were defined for Photofrin and mTHPC. Both photosensitizers caused similar toxicity profiles depending on drug dose, light fluence and time interval.

Animals↗
PubMed1994

Tissue distribution of the human MDR3 P-glycoprotein.

BACKGROUND: P-glycoproteins (Pgps) belong to a family of well conserved plasma membrane proteins with two members in humans: MDR1 and MDR3. The MDR1 Pgp can transport drugs; the murine homologue of MDR3, mdr2, was recently shown by us to be involved in transport of the phospholipid phosphatidylcholine (lecithin) into bile. EXPERIMENTAL DESIGN: We have determined the MDR3 mRNA levels in a panel of human tissues by RNase protection. We have also generated polyclonal antibodies specific for the MDR3 Pgp. Detection of the MDR3 Pgp in human tissues with these antibodies was by a streptavidin-ABC procedure. RESULTS: The RNase protection results show that expression of the MDR3 gene has a more restricted distribution than that of MDR1. A high level of MDR3 mRNA was detected in the liver and in low levels in the adrenal gland, heart, striated muscle, spleen, and tonsil. In all of these tissues, some of the previously described splice variants of MDR3 were abundantly expressed. No indications were found for a tissue-specific regulation of alternative splicing of the MDR3 pre-mRNA. Two MDR3 Pgp-specific antibodies stained the bile canalicular membrane of hepatocytes across the entire liver lobule. No staining was found in the epithelial cells of the bile ductules and gall bladder, indicating that the staining at these sites with C219, a monoclonal antibody that recognizes both MDR1 and MDR3 Pgp, (mainly) represents the MDR1 Pgp. No MDR3 was detected by specific antibodies in the adrenal gland, spleen, and muscle. Since no staining was reported with MDR1-specific antibodies in muscle either, our results indicate that the C219 staining in some fibers of striated muscle represents a cross-reaction with another protein. One of the human MDR3-specific antibodies cross-reacted with the highly homologous mouse mdr2 Pgp. Staining with this antibody showed that the distribution of this protein in mouse liver and striated muscle is very similar to that of MDR3 Pgp in human tissues. CONCLUSIONS: The highest expression of the MDR3 Pgp was found in liver in the canalicular membranes of hepatocytes. This is in agreement with a role for MDR3 in the transport of phospholipid into bile.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Report of a symposium on: diagnosis and treatment of cutaneous head and neck melanoma.

A series of presentations and discussions was held during a symposium on the diagnosis and treatment of cutaneous head and neck melanoma. The purpose of this meeting was to define certain guidelines on diagnosis and treatment of head and neck melanoma. The results of this symposium are summarized and condensed in this report. Recommendations are made for diagnostic strategies and for treatment. It is indicated that research efforts in immunology need to be expanded to develop rational immunotherapy.

Head and Neck Neoplasms↗
PubMed1992

Amplification of genes within the chromosome 11q13 region is indicative of poor prognosis in patients with operable breast cancer.

Amplification of the chromosome 11q13 region, which harbors the BCL1 region and the PRAD1, EMS1, HSTF1, and INT2 genes, was found in 36 (16%) of a series of 226 breast carcinomas. In the 153 patients with stage I-IIIa disease who had received no therapy prior to surgery and who were treated with curative intent, 11q13 amplification was associated with the presence of lymph node metastases (P less than 0.002). The presence of an 11q13 amplification was associated with a significantly shorter relapse-free survival (P less than 0.002) and a higher breast cancer-specific mortality (P less than 0.003). Stepwise multivariate analysis showed that, in addition to lymph node status, 11q13 amplification was the best predictor for short survival. Stratified log-rank analysis indicated that, within the group of lymph node-positive breast cancer patients, 11q13 amplification identifies a subgroup at high risk.

Breast Neoplasms↗
PubMed1992

Alternative splicing of neural-cell-adhesion molecule mRNA in human small-cell lung-cancer cell line H69.

The neural-cell-adhesion molecule (NCAM) is expressed in all small-cell lung cancers (SCLC) and in approximately 20% of non-small-cell lung tumors (non-SCLC). These NCAM-positive lung tumors have a poor prognosis compared with NCAM-negative tumors. Multiple NCAM protein isoforms are expressed from a single-copy gene as a result of alternative splicing and/or post-translational modifications. Therefore, we studied the NCAM isoforms expressed in a human small-cell lung-cancer cell line, H69. NCAM mRNA transcripts of 7.2, 6.7, 4.3 and 4.0 were detected in these cells on Northern blots. Since the various NCAM isoforms may have different biological properties, we performed a more precise examination of NCAM mRNAs, using polymerase chain reactions (PCR) with primers flanking the various NCAM exon boundaries. The shortest alternatively spliced sequence that we found was the trinucleotide AAG located between exon 12 and 13 in the so-called hinge region of the NCAM protein. This AAG trinucleotide was present in the majority of the NCAM mRNAs. A second alternatively spliced 30 nt-exon VASE (immunoglobulin-variable domain-like alternatively spliced exon) was present in all NCAM transcript isoforms at the exon 7/exon 8 junction. VASE resulted in the insertion of 10 amino acids into the 4th immunoglobulin-like loop of the NCAM protein. Within the limits of the PCR methodology, no evidence for the presence of mRNA containing exon 15, encoding the glycosyl-phosphatidylinositol-linked (GPI-linked) NCAM isoform in H69 cells was obtained. Considering that H69 cells express 2 major NCAM protein classes (NCAM-180 and NCAM-140), and that the VASE and AAG alternative mRNA splice variants result in minor differences in protein sizes, at least 8 polypeptide isoforms of NCAM might be expressed in H69 cells that contribute to the binding interactions of NCAM.

Amino Acid Sequence↗
PubMed1992

DNA-flow cytometry of head and neck carcinoma: the importance of uniform tissue sampling and tumor sites.

Flow cytometric DNA ploidy measurements using deparaffinized tumor specimens were performed on 46 squamous cell carcinomas of the head and neck, including 22 carcinomas of the oropharynx, 18 carcinomas of the larynx and six carcinomas of the oral cavity. Aneuploidy was found in 14 of these tumors with carcinomas of the larynx and oral cavity showing almost equal percentages of DNA aneuploidy (10/18 and 3/6, respectively). In contrast, only 1 of the oropharyngeal carcinomas was aneuploid. Accurate microscopy-controlled sampling of tumor tissue from the histological tissue blocks was found to be mandatory in order to obtain reliable ploidy measurements.

Carcinoma, Squamous Cell↗
PubMed1992

Functional and histological damage in the mouse bladder after photodynamic therapy.

Bladders of anaesthetised mice were illuminated with laser light of 630 nm at 24 h after intraperitoneal administration of the photosensitiser Photofrin II (10 mg kg-1). A range of light doses, at a power setting of 100 mW, was delivered intravesically by a fibre optic inserted into the centre of the bladder via the urethra. Functional bladder damage was assessed from increases in urination frequency and the presence of urethra. Functional bladder damage was assessed from increases in urination frequency and the presence of haematuria at 1 to 26 weeks after treatment. Whole bladder illumination with incident light doses exceeding 18.75 J cm-2 caused extensive oedema, haemorrhage and necrosis of the bladder wall and mice had to be sacrificed within 24 h. PDT with incident light doses of 3.75 to 15.0 J cm-2 caused haematuria and increased urination frequency during the first week in nearly all mice, but there was complete functional recovery by 6 to 10 weeks after doses of up to 7.5 J cm-2. Recovery was slower after higher doses and up to 50% of mice still had some increased urination frequency at 10 weeks after greater than or equal to 11.25 J cm-2, although haematuria was rare at this time. Histologically, early damage (one day after PDT) consisted of epithelial sloughing, submucosal oedema, fibrin imbibition, vascular ectasia and, rarely, thrombosis. Doses exceeding 7.5 J cm-2 were often associated with foci of necrosis. In some instances, necrosis was complicated by bacterial infection, resulting in an acute transmural inflammation with a tendency to suppuration. After doses of up to 11.25 J cm-2 there was a gradual recovery and only a mild degree of fibrosis of the bladder wall (with some increase in vascularity) remained at 6 months.

Animals↗
PubMed1992

Serum neuron-specific enolase and lactate dehydrogenase as predictors of response to chemotherapy and survival in non-small cell lung cancer.

The prognostic value of serum neuron-specific enolase (NSE) and lactate dehydrogenase (LDH) was prospectively assessed in 42 patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) treated within two chemotherapy trials. Pretreatment NSE levels ranged from 4.6 to 34.6 ng/mL (median value, 7.5) and were above 10 ng/mL in ten patients (23.8%). LDH levels varied between 85 U/L and 2,484 U/L (median value, 220) and were above 250 U/L in 12 patients (29.3%). Elevated levels of both enzymes were significantly more common in patients with metastatic disease than in those with locoregional disease (40% v 9% for NSE and 40% v 18% for LDH, respectively). Strong positive correlation (correlation factor 0.693) was found between NSE and LDH serum levels. The levels of both markers did not correlate with age, sex, previous therapy, performance status, or histology. Responses to chemotherapy were seen more frequently in patients with elevated NSE levels (six of ten, 60%) than in those with normal values (seven of 32, 22%; P = .02). Similar correlation was found for LDH: Response was seen in seven of 12 patients with elevated levels (58%) and in six of 29 (21%) of those with normal values (P = .02). In a logistic regression analysis, both markers considered individually remained significant when adjusted by sex, age, performance status, prior therapy, histology, and extent of disease. Three pretreatment characteristics, high levels of NSE and LDH (both considered as continuous variables) and metastatic disease, were found to be associated with shorter survival; with adjustment for extent of disease, however, NSE and LDH were no longer correlated with shorter survival. These data suggest potential clinical value of NSE and LDH determination in treatment selection of NSCLC patients.

Adult↗
PubMed1992

A rapid and simple procedure for the routine detection of ras point mutations in formalin-fixed, paraffin-embedded tissues.

The use of the polymerase chain reaction (PCR) to detect specific DNA sequences in small amounts of tissues or cells has become a widespread tool in the field of molecular biology. With the better understanding of the clinical significance of oncogene activations in human tumors, the application of PCR in a routine setting is rapidly gaining importance. We have developed a rapid and simple procedure for the detection of mutated ras oncogenes in routinely fixed, paraffin-embedded tissue samples. DNA is isolated from three 10 microns tissue sections by incubation with a nonionic detergent and proteinase K, and can be directly used for amplification by PCR. The amplified DNA fragments are then dot-blotted onto nylon membranes and are hybridized to radioactively labeled oligodeoxynucleotides, specific for each of the mutated ras sequences. After a selective washing procedure, only fully matched oligodeoxynucleotides remain bound to the membrane, thus revealing the nature of the sequences that were present in the starting material. With this method, the detection of point mutations in ras genes can be performed in a routine setting, and the results of the analyses can be available in as few as 3-4 days.

Base Sequence↗
PubMed1992

Identification and cloning of two overexpressed genes, U21B31/PRAD1 and EMS1, within the amplified chromosome 11q13 region in human carcinomas.

Amplification of the chromosome 11q13 region is frequently found in human breast cancer and in squamous cell carcinomas of the head and neck, and has been associated with an unfavourable clinical course of disease. The known oncogenes within the amplified 11q13 region, INT2 and HSTF1, are rarely expressed in these tumours, indicating that another, hitherto unidentified, gene or genes confer(s) the biological (prognostic) significance to the amplification of the 11q13 region. To identify the gene or genes, we have constructed a cDNA library from a cell line with an 11q13 amplification and have performed differential cDNA cloning using [32P]dCTP-labelled cDNAs from human squamous cell carcinoma cell lines with and without an 11q13 amplification. We isolated two cDNA clones, U21B31 and U21C8, which recognize two genes amplified and overexpressed in cell lines harbouring an 11q13 amplification. In breast carcinomas and in squamous cell carcinomas amplification of both the U21B31 and the U21C8 gene was found in most tumours with an amplification of the 11q13 region, despite the large distance between both genes. Sequence analysis of the U21C8 cDNA clone revealed no homology to known genes; we call this gene EMS1. The U21B31 cDNA clone corresponded to the 3' end of the PRAD1 proto-oncogene, recently cloned from a parathyroid adenoma. Both gene products are of interest as potential markers to identify tumours with an 11q13 amplification.

Breast Neoplasms↗
PubMed1991

Differential activation of ras genes by point mutation in human colon cancer with metastases to either lung or liver.

To study the possible role of ras oncogene activation in the dissemination of colon cancer, we determined point mutations in codons 12, 13 and 61 in K- and N-ras in 3 groups of tumors: (A) primary tumors of patients who had undergone surgery for Dukes' B (early-stage) colon cancer, (B) primary tumors and metastases from patients undergoing resection of isolated lung metastases and (C) primary tumors and metastases from patients undergoing resection of isolated liver metastases. In 129 samples from 93 patients, 54 (42%) were positive for point mutations in either K- or N-ras. Most mutations (89%) were found in the K-ras gene. In group A (n = 50) ras point mutations were detected in 16 cases (32%) (15 in K-ras and 1 in N-ras). Thirteen out of 23 cases in group B (57%) were positive for a ras point mutation: 10 in K-ras and 3 in N-ras. In group C (n = 20), point mutations in codon 12 of K-ras, but none in H- or N-ras, were found in 10 cases (50%). In 31 cases the primary tumors from the metastases in groups B and C were available for analysis and 15 contained a ras point mutation (48%). Not all mutations were present in both the primary tumor and the metastasis. In 3 instances, a mutation was detected in the metastasis but not in the primary tumor, whereas in 1 case a mutation was found in the primary tumor.

Adenocarcinoma↗
PubMed1991

Relationship between K-ras oncogene activation and smoking in adenocarcinoma of the human lung.

To investigate a possible relationship between the exposure to tobacco smoke and the presence of ras point mutations, we examined lung adenocarcinoma samples from 27 smokers and from 27 nonsmokers. Activating point mutations in K-ras (also known as KRAS2) and N-ras (also known as NRAS) were determined by using the polymerase chain reaction and oligonucleotide hybridization to detect the mutated sequences. Mutations were more often found in adenocarcinomas obtained from smokers (eight of 27) than in adenocarcinomas obtained from nonsmokers (two of 27) (P = .044, Fisher's exact test). All mutations were present in K-ras codon 12. None of the other parameters examined differed significantly between the ras-positive and ras-negative groups. We conclude that exposure to carcinogenic agents in tobacco smoke is an important factor in the induction of point mutations in K-ras in human lung adenocarcinomas, but that K-ras mutations may also infrequently occur in tumors of non-smokers.

Adenocarcinoma↗