Avidin targeting of intraperitoneal tumor xenografts.
Yao Z. Zhang M. Sakahara H. Saga T. Arano Y. Konishi J.
Department of Nuclear Medicine, Faculty of Medicine, Kyoto University, Japan. email@example.com
BACKGROUND: Lectins (proteins that bind specific sugar molecules on glycoproteins and glycolipids) are expressed at various levels on the surface of tumor cells. Conjugation of cytotoxic agents to glycoproteins recognized by lectins could be useful in the treatment of tumors. Avidin (a highly glycosylated, positively charged protein found in egg white) contains terminal N-acetylglucosamine and mannose residues that bind to some lectins. In this study, we tested the ability of avidin, labeled through conjugation to radioactive biotin (a B vitamin), to target intraperitoneal tumors. METHODS: Biotin was radioactively labeled with 111In. Four tumor models (one ovarian, one lung, and two colon) were established in nude mice by intraperitoneal injection of cultured cancer cells. The following two approaches were used in the intraperitoneal administration of avidin: 1) radioactive biotin-avidin conjugates were injected and 2) avidin was injected 1-24 hours before the injection of radioactive biotin (avidin pretargeting; avidin-biotin conjugates formed in vivo). The distribution of injected radioactivity in the tissues of treated animals was assessed. RESULTS: Radiolabeled avidin localized highly and rapidly in the tumors. More than 50% of the administered dose of avidin-biotin conjugate accumulated per gram of tumor tissue 2 hours after injection; high tumor uptake of radioactivity was observed up to 24 hours after conjugate injection. In contrast, accumulation of radioactivity in normal tissues was low, yielding high tumor to nontumor ratios. With avidin pretargeting, accumulation of radioactivity in the liver, kidney, and spleen was reduced to a greater extent than that in the tumor, and tumor to nontumor ratios were increased. CONCLUSIONS: Avidin may be a promising vehicle for the delivery of radioisotopes, drugs, toxins, or therapeutic genes to intraperitoneal tumors.
Folate intake, alcohol consumption, cigarette smoking, and risk of colorectal adenomas.
Baron JA. Sandler RS. Haile RW. Mandel JS. Mott LA. Greenberg ER.
Department of Community and Family Medicine, Dartmouth Medical School, and the Norris Cotton Cancer Center, Hanover, NH, USA. John.Baron@dartmouth.edu
BACKGROUND: Recent evidence suggests that folic acid (and derivatives) could contribute to the protective effect of fruits and vegetables against the risk of large-bowel cancer. Other evidence indicates that alcohol drinking and cigarette smoking may impair the biologic actions of folate. We used data from an adenoma prevention trial to investigate the occurrence of colorectal adenomas (possible precursors of colorectal cancer) in association with folate intake, alcohol consumption, and cigarette smoking. METHODS: Patients with at least one recent large-bowel adenoma were followed with colonoscopy 1 year and 4 years after their qualifying colon examinations. Adenomas detected after the year 1 examination were used as end points. A food-frequency questionnaire was administered at study entry and at study completion; nutrient intake at study entry was used in this analysis. All statistical tests were two-sided. RESULTS: After adjustment for caloric intake, dietary folate had a significant protective association with the risk of recurrence of large-bowel adenoma (P for trend = .04). However, this inverse association was attenuated by further adjustment for intake of dietary fiber and fat. Use of folate supplements was not associated with a reduction in risk. Alcohol intake (seven or more drinks/week) was associated with increased risk (odds ratio = 2.04; 95% confidence interval = 1.28-3.26). Cigarette smoking, even smoking for long duration, was not related to adenoma recurrence. CONCLUSIONS: These data provide only modest support for previous findings suggesting beneficial effects of folate on colorectal adenoma risk. We find no evidence that cigarette smoking increases risk. These findings do suggest a substantial increase in risk with alcohol consumption.
Body mass index and risk of adenocarcinomas of the esophagus and gastric cardia.
Chow WH. Blot WJ. Vaughan TL. Risch HA. Gammon MD. Stanford JL. Dubrow R. Schoenberg JB. Mayne ST. Farrow DC. Ahsan H. West AB. Rotterdam H. Niwa S. Fraumeni JF Jr.
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA.
BACKGROUND: Incidence rates have risen rapidly for esophageal adenocarcinoma and moderately for gastric cardia adenocarcinoma, while rates have remained stable for esophageal squamous cell carcinoma and have declined steadily for noncardia gastric adenocarcinoma. We examined anthropometric risk factors in a population-based case-control study of esophageal and gastric cancers in Connecticut, New Jersey, and western Washington. METHODS: Healthy control subjects (n = 695) and case patients with esophageal squamous cell carcinoma or noncardia gastric adenocarcinoma (n = 589) were frequency-matched to case patients with adenocarcinomas of esophagus or gastric cardia (n = 554) by 5-year age groups, sex, and race (New Jersey only). Classification of cases by tumor site of origin and histology was determined by review of pathology materials and hospital records. Data were collected using in-person structured interviews. Associations with obesity, measured by body mass index (BMI), were estimated by odds ratios (ORs). All ORs were adjusted for geographic location, age, sex, race, cigarette smoking, and proxy response status. RESULTS: The ORs for esophageal adenocarcinoma rose with increasing adult BMI. The magnitude of association with BMI was greater among the younger age groups and among nonsmokers. The ORs for gastric cardia adenocarcinoma rose moderately with increasing BMI. Adult BMI was not associated with risk of esophageal squamous cell carcinoma or noncardia gastric adenocarcinoma. CONCLUSIONS: Increasing prevalence of obesity in the United States population may have contributed to the upward trends in esophageal and gastric cardia adenocarcinomas.
Possible role of telomerase activation in the cancer predisposition of patients with hereditary nonpolyposis colorectal cancers.
Cheng AJ. Tang R. Wang JY. See LC. Wang TC.
Department of Molecular and Cellular Biology, College of Medicine, Chang Gung University, Taiwan, Republic of China.
BACKGROUND: Hereditary nonpolyposis colorectal cancer syndrome (HNPCC syndrome; also called Lynch syndrome) is one of the most common cancer predisposition syndromes. Most cases of cancer associated with this syndrome are due to the inheritance of germline mutations in genes that encode proteins required for DNA mismatch repair; defects in these proteins allow mutations to accumulate more rapidly in the DNA and influence the rate of cancer development. Recent studies indicate that the reactivation of the activity of telomerase, an enzyme involved in the synthesis of chromosomal ends, in somatic cells may play a role in carcinogenesis. In this study, we evaluated the expression of telomerase in normal and cancerous colorectal tissue specimens from HNPCC and non-HNPCC patients. METHODS: The polymerase chain reaction-based telomeric repeat amplification protocol was used to assay telomerase activity in colorectal tissue specimens from 33 non-HNPCC patients (23 normal, 26 polyps, and 37 cancer specimens) and from 24 HNPCC patients (24 normal, 0 polyps, and 28 cancer specimens). RESULTS: Thirty-one of 37 carcinoma samples from 18 non-HNPCC patients and 27 of 28 carcinoma samples from 24 HNPCC patients were found to be positive for telomerase activity. Whereas only one of 23 normal mucosa samples from 23 non-HNPCC patients was found to have (weak) telomerase activity, eight of 24 normal mucosa samples from 24 HNPCC patients were positive for telomerase; the difference between the two groups was statistically significant (two-sided P = .0226). IMPLICATION: This study generates the hypothesis that genetic defects in individuals with HNPCC syndrome facilitate the reactivation of telomerase activity, a process which may be associated with their predisposition to develop cancer.
Trends and outcomes of outpatient mastectomy in elderly women.
Warren JL. Riley GF. Potosky AL. Klabunde CN. Richter E. Ballard-Barbash R.
Applied Research Branch, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD 20892-7344, USA.
BACKGROUND: Considerable public attention has focused on the use of outpatient mastectomy and has resulted in numerous legislative proposals to mandate a minimum hospital stay following mastectomy. To date, only limited scientific data are available regarding the use and the outcomes of outpatient mastectomy. The purpose of this study was to provide population-based information on trends and outcomes for outpatient mastectomy in elderly women. METHODS: Medicare data for elderly women with fee-for-service coverage were examined for trends and regional variation in the use of outpatient mastectomy. Logistic regression was used to identify patient and provider characteristics associated with having an outpatient mastectomy, and outcomes were assessed by calculating the risk of being rehospitalized and the reasons for rehospitalization. RESULTS: From 1986 through 1995, the proportion of mastectomies performed on an outpatient basis increased from virtually 0% to 10.8%. Outpatient mastectomies were more likely to be performed on women with no coexisting health problems in hospitals that were for-profit or non-teaching or in large metropolitan statistical areas. Women undergoing outpatient mastectomy had substantially higher rates of rehospitalization within 30 days than women with a 1-day stay in the hospital. Both groups had comparable rates of rehospitalization for complications definitely related to their surgery. The percentage of women who required rehospitalization was low, and the actual number of women rehospitalized was relatively small. CONCLUSIONS: We conclude that the risks from outpatient mastectomy are modest, although ongoing monitoring of outcomes and assessment of patient satisfaction are needed.
Molecular evidence for multifocal papillary serous carcinoma of the peritoneum in patients with germline BRCA1 mutations.
Schorge JO. Muto MG. Welch WR. Bandera CA. Rubin SC. Bell DA. Berkowitz RS. Mok SC.
Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. JOSCHORGE@BICS.BWH.HARVARD.EDU
BACKGROUND: Papillary serous carcinoma of the peritoneum (PSCP) diffusely involves peritoneal surfaces, while it spares or only superficially involves the ovaries. PSCP is histologically indistinguishable from serous epithelial ovarian carcinoma, and it may develop years after oophorectomy. The molecular pathogenesis of PSCP remains unresolved, although preliminary data suggest a multifocal origin in some cases. Patients with germline BRCA1 mutations may develop PSCP in addition to breast and ovarian carcinomas. The purpose of this study was to utilize the androgen receptor (AR) gene locus to test the hypothesis that some cases of PSCP have a multifocal origin and to determine if patients with germline BRCA1 mutations develop multifocal PSCP. METHODS: Specimens of normal and tumor tissues from 22 women with PSCP were obtained, and DNA was extracted. The AR gene locus was evaluated for patterns of loss of heterozygosity (LOH) and X-chromosome inactivation. The methylation-sensitive Hpa II restriction enzyme was used to differentiate the active and inactive X chromosomes. Germline BRCA1 mutation status of the patients was determined previously. RESULTS: Genetic analysis of tumor specimens indicated that five (23%) of 22 case subjects had patterns of selective LOH at the AR locus, consistent with multifocal, polyclonal disease origin. Two patients with selective LOH also had alternating X-chromosome inactivation patterns. Patients with germline BRCA1 mutations were more likely to have evidence of multifocal disease (two-sided Fisher's exact test, P = .01). CONCLUSIONS: Our results show that PSCP has a multifocal origin in at least some cases. Furthermore, patients with germline BRCA1 mutations are more likely to develop multifocal PSCP than are patients without BRCA1 mutations.
Kirsten ras mutations in patients with colorectal cancer: the multicenter RASCAL study.
Andreyev HJ. Norman AR. Cunningham D. Oates JR. Clarke PA.
Department of Medicine, Royal Marsden Hospital, Institute of Cancer Research, Sutton, Surrey, UK.
BACKGROUND: Kirsten ras (Ki-ras) gene mutations occur early in the progression of colorectal adenoma to carcinoma. The aim of this collaborative study was to clarify the association between Ki-ras mutations, patient outcome, and tumor characteristics by use of data from colorectal cancer patients worldwide. METHODS: Investigators who had published data on Ki-ras and colorectal cancer were invited to complete a questionnaire for each patient entered into a database. Two-sided statistical tests were used to analyze data. RESULTS: Patients (n = 2721) were recruited from 22 groups in 13 countries. Mutations of Ki-ras codon 12 (wild type = GGT = glycine) or codon 13 (wild type = GGC = glycine) were detected in 37.7% of the tumors; 80.8% (584 of 723) of all the specified mutations occurred in codon 12, and 78.1% (565 of 723) of all the specified mutations were at the second base of either codon. Mutations were not associated with sex, age, tumor site, or Dukes' stage. Mutation rates seen in patients with sporadic tumors were comparable to those observed in patients with a predisposing cause for their cancer. Poorly differentiated tumors were less frequently mutated (P = .002). Multivariate analysis suggested that the presence of a mutation increased risk of recurrence (P
Colorectal carcinoma invasion inhibition by CO17-1A/GA733 antigen and its murine homologue.
Basak S. Speicher D. Eck S. Wunner W. Maul G. Simmons MS. Herlyn D.
The Wistar Institute, Philadelphia, PA 19104, USA.
BACKGROUND: The gastrointestinal carcinoma antigen GA733 is a potential target for passive and active immunotherapy for patients with colorectal carcinoma. This antigen has been characterized previously as a homophilic adhesion (i.e., adhesion to self) protein, but the functional consequences of homophilic adhesion for tumor growth and invasion are unknown. The availability of a murine homologue of GA733, i.e., murine epithelial glycoprotein (mEGP), allows for functional analysis of cell adhesion as it relates to tumor growth and invasion, both in vitro and in vivo. METHODS: CT-26 murine colorectal carcinoma cells were transfected with complementary DNAs encoding either the human or the murine antigen. GA733- or mEGP-producing cells were evaluated for homophilic adhesion, growth on plastic surfaces, colony formation in soft agar, and invasion through a reconstructed basement membrane (Matrigel). mEGP-producing cells were also examined for their capacity to metastasize in mice. Reported P values are two-sided. RESULTS: Compared with control cells, mEGP-producing cells showed significantly lower growth rates, colony formation, and invasion through Matrigel in vitro (all P values