Biomedical subjects

B D Li

Publications and source records attributed to B D Li.

At least 19 recordsLinked to original sources

PubMed2001

Free insulin-like growth factor-I and breast cancer risk.

Insulin-like growth factor-I (IGF-I) has mitogenic and anti-apoptotic effects on breast cancer cells. Epidemiologic studies have shown that high plasma levels of IGF-I and low levels of IGF binding protein (BP)-3 are associated with increased risk of breast cancer in premenopausal women. The actions of IGF-I are mediated through the IGF-I receptor (IGF-IR) and are regulated by IGFBPs. In circulation, most of the IGF-I binds to IGFBP-3, and binding of IGF-I to IGFBP-3 inhibits the actions of IGF-I. Since free IGF-I, which does not bind to IGFBPs, can readily cross the endothelial barrier to interact with IGF-IR, circulating free IGF-I is thought to be more relevant to the biologic activity of IGF-I. To examine the association of free IGF-I with breast cancer, we compared free IGF-I levels between 40 newly diagnosed breast cancer patients and 40 age- and race-matched healthy controls. Plasma levels of free IGF-I, total IGF-I and IGF-II, as well as total, intact and fragment IGFBP-3, were measured using commercial immunoassay kits. The association between IGF-I and breast cancer was examined using the conditional logistic regression analysis. Analysis of correlation (Spearman) showed that free IGF-I was correlated with total IGF-I and IGFBP-3 but not with IGF-II. The odds ratios for breast cancer patients having high plasma IGF-I (> or = median) after adjusting for menopausal status and IGFBP-3 were 2.00 (p < o r = 0.376) for total IGF-I and 6.31 (p < or = 0.047) for free IGF-I. A high ratio of IGF-I to IGFBP-3 was also associated with breast cancer (p < 0.05). No association was found for IGF-II, nor for total, intact and fragment IGFBP-3. The findings of this study suggest that measuring free IGF-I in circulation is more useful than measuring total IGF-I with respect to evaluation of an association between IGF-I and breast cancer risk.

Adult↗

PubMed2001

Polymorphic CA repeats in the IGF-I gene and breast cancer.

Insulin-like growth factor (IGF)-I is a potent mitogen for breast cancer cells and may play a role in the disease. Although the involvement of IGF-I phenotype in breast cancer has been studied extensively, little is known about IGF-I genotype in relation to the disease. The IGF-I gene contains a polymorphic region composed of multiple cytosine-adenine dinucleotides (CA repeats). Studies of other genes indicate that the CA-repeat region in the promoter of a gene may affect transcription activity and that the length of the repeat is inversely correlated with transactivation. To examine if the IGF-I polymorphism is associated with breast cancer, we compared the length of CA repeats in the IGF-I gene between 53 breast cancer patients and 53 controls. Genomic DNA extracted from peripheral blood was used to determine the number of CA repeats through PCR amplification and DNA sequencing. Associations between CA repeats and breast cancer were assessed using unconditional logistic regression analysis. The results showed that the median number of CA repeats was 19, ranging from 15 to 23, and that compared to women without 19 CA repeats, women with 19 CA repeats were more likely to be breast cancer patients (OR = 2.87, 95%CI: 1.16-7.06) after adjusting for age, race, menopausal status, age at menopause, and alcohol use. The study also suggested possible synergistic interplay between IGF-I genotype and phenotype as women with 19 CA repeats and high plasma IGF-I had a much higher odds ratio for breast cancer (OR = 5.12, 95%CI: 1.42-18.5) than those with only one of the conditions. If our observations can be confirmed in larger studies, the findings will provide further evidence to support the role of IGF-I in breast cancer and the link between genetic polymorphism and cancer susceptibility.

Adult↗

PubMed2000

Progression of eIF4e gene amplification and overexpression in benign and malignant tumors of the head and neck.

BACKGROUND: The overexpression of eukaryotic initiation factor 4E (eIF4E) results in the up-regulation of gene products of mRNAs with long 5' untranslated regions (5' UTRs). The degree of gene amplification increases from the tumor free zone to the tumor core. This led the authors to hypothesize that the degree of eIF4E gene amplification and oncoprotein overexpression is progressive in the cells from normal head and neck tissue, to benign tumors, and eventually to invasive carcinomas (HNCA). METHODS: Using competitive polymerase chain reaction (PCR) and Western blot analysis, benign specimens from similar sites of 10 noncancer patients, 8 pleomorphic adenoma specimens, and 18 HNCA specimens were studied. DNA and protein extracts from each specimen were quantified for eIF4E gene copy number and level of eIF4E protein expression. RESULTS: There was no detectable eIF4E gene amplification and oncoprotein overexpression in benign tissue from noncancer patients (1.1 +/- 0.5 gene copy number [mean +/- standard deviation] and 0.9 +/- 0.5-fold protein elevation, respectively). Four of the eight pleomorphic adenomas analyzed showed eIF4E gene amplification of at least twofold, but none demonstrated protein elevation of any significance. In contrast, all HNCA specimens had detectable eIF4E gene amplification and protein overexpression. Furthermore, the mean degree of eIF4E gene amplification and overexpression was found to increase as cells from benign head and neck tissues (1.1 +/- 0.5 and 0.9 +/- 0.5), benign tumors (2.2 +/- 1.3 and 1.02 +/- 0.19), and HNCA (4.3 +/- 1.2 and 15.5 +/- 9.3) were compared. CONCLUSIONS: Progressive eIF4E gene amplification and overexpression were detected when normal tissues, benign tumors, and HNCA were compared. The degree of gene amplification and overexpression is variable within each tissue category. However, progression to malignant phenotype appears to be associated with an increasing degree of eIF4E gene amplification and overexpression.

Adenoma, Pleomorphic↗

PubMed2000

Patient compliance is critical for equivalent clinical outcomes for breast cancer treated by breast-conservation therapy.

OBJECTIVE: To determine the compliance with a standard breast-conservation therapy (BCT) program in a predominantly indigent, minority population of patients with early breast cancer (stage I and II) served by a rural state institution in the South; to compare the clinical outcomes of this group with those reported in clinical trials; and to examine the socioeconomic factors that may have contributed to the rate of compliance. SUMMARY BACKGROUND DATA: Disease-free survival and overall survival in early breast cancer treated by BCT versus modified radical mastectomy are reported to be equivalent in prospective randomized trials. However, patients enrolled in clinical trials may not be representative of patients living in the various diverse communities that make up the United States. The authors' hypothesis is that patients enrolled in clinical trials at the national level may not be representative of indigent patients in the rural South and that clinical trial results may not be directly applicable. METHODS: A retrospective review of 55 women with early-stage breast cancer treated from 1990 to 1995 was performed. Clinical data, compliance with treatment and clinical follow-up, and recurrence rates were examined. Statistical analysis performed include the Fisher exact test, Kaplan-Meier survival analysis, and log-rank test. RESULTS: Full compliance (defined as completion of the entire course of radiation therapy and clinical follow-up) with the BCT program was observed in only 36% of patients. Fifteen of the 35 noncompliant patients did not complete radiation therapy. A significantly higher local failure rate was observed: 8 of these 15 patients (53%) have had local failure. In contrast, patients who were either in full compliance with the BCT program or were deficient only in that they missed part of their clinical follow-up had local failure rates of 5% (1/20) and 10% (2/20), respectively. Age, race, stage of cancer, economic status (measured by availability of medical insurance), distance of patient's residence from the hospital, and education level were evaluated as potential predictors of compliance. None predicted patient compliance, although a trend toward higher compliance was noted in patients with a higher education level, as determined by literacy testing. CONCLUSIONS: Compliance with the BCT protocol at the authors' institution was worse than reported in clinical trials, and noncompliance translated into a significant increase in the local failure rate. Factors examined suggest that literacy may play a role in predicting compliance. Although BCT should be discussed with all breast cancer patients, the judicious application of clinical trial data to an institution's local population is warranted.

Breast Neoplasms↗

PubMed1999

Elevated expression of eIF4E in confined early breast cancer lesions: possible role of hypoxia.

The translation-initiation factor eIF4E is rate-limiting for protein synthesis, and its over-expression results in oncogenic transformation of mammalian cells. eIF4E facilitates the synthesis of several powerful tumor angiogenic factors (FGF-2 and VEGF) by selectively enhancing their translation. In breast carcinomas, eIF4E is commonly over-expressed, but the pathology where this elevation is initially manifested is presently unknown. To probe whether the elevation of eIF4E marks an early stage of cancer development, we focused our research on early cancerous lesions. We have analyzed 70 invasive ductal carcinomas (IDCs), 78 ductal carcinomas in situ (DCIS), 51 benign lesions and 4 model cell lines for elevated expression of eIF4E by several different methods: Northern/Western blots, immuno-histochemistry and in situ RT-PCR. eIF4E expression was markedly increased in IDC and in islets of viable cells in the center of poorly vascularized DCIS, which are not easily identifiable by standard histological stains. We also show that expression of eIF4E is increased by hypoxia and, presumably, in hypoxic areas of these lesions. We propose that clonal expansion of cancer cells, permanently over-expressing eIF4E, gives them a critical advantage to survive hypoxia and marks the transition toward the vascular phase of cancer progression. Hence, eIF4E may be useful in stratifying DCIS lesions according to their malignant stage.

Blotting, Western↗

PubMed1999

Potential utility of sentinel node biopsy in the original surgical assessment of Hürthle cell tumors of the thyroid: 23-year institutional review of Hürthle cell neoplasms.

BACKGROUND AND OBJECTIVES: Great difficulty still exists in determining the potential malignancy of Hürthle cell tumors of the thyroid gland. Indications for the extent of resection vary greatly in the reported literature. Sentinel node biopsy has shown its usefulness as a prognostic indicator in both melanoma and breast cancer. The feasibility of using it as an integral part of Hürthle cell tumor surgery was investigated and is discussed. METHODS: Eleven patients diagnosed with Hürthle cell tumors between the years of 1975 and 1998 were reviewed. The last three patients had sentinel node biopsy with isosulfan blue dye as an integral part of their procedure. RESULTS: Sentinel node biopsy was accomplished without difficulty or complication in our last three patients. Two patients were considered to be benign by frozen section and final pathology. Their sentinel nodes were benign. One patient was considered malignant on both frozen and final pathology. His sentinel nodes as well as central node dissection revealed no lymphatic spread. CONCLUSIONS: Malignancy of Hürthle cell tumors of the thyroid is difficult to determine even on final pathological examination. The addition of nodal sampling may add valuable prognostic information. Sentinel node biopsy with isosulfan blue dye, although not previously reported for these tumors, appears to be a logical next step in the evolution of surgical management.

Adenoma, Oxyphilic↗

PubMed1999

Competitive PCR to detect eIF4E gene amplification in head and neck cancer.

BACKGROUND: The protein eukaryotic initiation factor 4E (elF4E) binds to messenger ribonucleic acid (mRNA) as the initial step in protein synthesis. Overexpression of elF4E results in upregulation of specific proteins essential to cell growth and division. Overexpression of elF4E has been found in head and neck squamous cell carcinoma (HNSCC) and breast carcinoma. This study's purpose is to determine whether elF4E overexpression is present and associated with elF4E gene amplification in HNSCC. METHODS: Competitive polymerase chain reaction (PCR) was performed on eight HNSCC and seven intraoral benign lesions to determine the copy number of elF4E relative to a reference gene, gastrin. Western blots were performed to quantify elF4E protein expression. RESULTS: All eight HNSCC specimens demonstrated significant (p < .005) overexpression of elF4E protein (14.1+/-10.4) and elF4E gene amplification (4.5+/-1.2). Benign tissue did not exhibit elF4E protein overexpression or gene amplification. CONCLUSIONS: Overexpression and associated gene amplification of elF4E were present in HNSCC but not in benign tissue. Gene amplification of elF4E may be an important mechanism for elF4E overexpression.

Blotting, Western↗

PubMed1999

Pattern of amplification and overexpression of the eukaryotic initiation factor 4E gene in solid tumor.

BACKGROUND: An abundance of eukaryotic initiation factor 4E (eIF4E), a rate-limiting initiation component in protein synthesis of mRNAs with long 5'-UTRs, has been shown to upregulate a number of oncogene products. Elevation of eIF4E protein has been detected both in infiltrating ductal carcinoma of the breast (IDCA) and in head and neck squamous cell carcinoma (HNSCC) specimens. We hypothesized that malignant progression in solid tumor is associated with progressive eIF4E gene amplification and protein overexpression in cells sampled from the tumor-free resection margin, transition zone (area adjacent to cancer), and tumor core (center of tumor). MATERIALS AND METHODS: Thirty-eight resected specimens were evaluated: 10 IDCA, 13 HNSCC, and 15 benign specimens from similar sites of noncancer patients. IDCA and HNSCC specimens were divided into three different zones: (1) tumor core, (2) transition zone, and (3) tumor-free zone. Quantitative PCR for the eIF4E gene and Western blots for the eIF4E protein were performed on each of these zones and on the normal controls of benign tissue. Immunohistochemical staining was performed to localize the eIF4E protein overexpression in situ. RESULTS: The eIF4E gene was amplified in the tumor core of both IDCA (3.8 +/- 1.4, P < 0.05, Student's t test) and HNSCC (4.3 +/- 1.4, P < 0.05) specimens. Similarly, the eIF4E protein was overexpressed in the cells from these same sites (17.4 +/- 7.3- and 14.0 +/- 9.7-fold elevation, respectively, P < 0.0001). In the transition zone of IDCA and HNSCC, the degrees of eIF4E gene amplification (4.2 +/- 1.0 and 3.7 +/- 1.2, respectively) and overexpression (4.0 +/- 1.0 and 4.4 +/- 4.6, respectively) were intermediate. In contrast, the eIF4E gene copy number and protein level were near baseline in the tumor-free zone. CONCLUSIONS: Progressive eIF4E gene amplification and protein overexpression were present in cells sampled from the microscopically tumor-free margin to tumor core in surgical specimens of both HNSCC and IDCA. In this study, eIF4E gene amplification and protein overexpression appear to be associated with malignant progression in these two solid tumors.

Blotting, Western↗

PubMed1999

Progressive amplification and overexpression of the eukaryotic initiation factor 4E gene in different zones of head and neck cancers.

PURPOSE: Eukaryotic initiation factor 4E (eIF4E) binds to mRNA as the initial rate-limiting step in protein synthesis. Amplification and overexpression of the eIF4E gene has been associated with malignant transformation. The objectives of this study were to 1) quantify the eIF4E gene in head and neck squamous cell carcinoma (HNSCC) specimens, 2) quantify eIF4E protein elevation and examine its association with eIF4E gene amplification, and 3) determine whether there is progression in eIF4E gene amplification and protein overexpression in the tumor-free resection margin, the transition zone, and the tumor core of HNSCC specimens. MATERIALS AND METHODS: Eighteen HNSCC specimens were divided into three zones: 1) tumor core; 2) transition zone; and 3) "tumor-free" margin. Competitive polymerase chain reaction was performed to determine eIF4E gene copy number. eIF4E protein expression was quantified using Western blot analysis. RESULTS: All 18 HNSCC specimens tested had significant eIF4E gene amplification (4.3+/-1.2; P < .05). In contrast, none of the 10 benign specimens from noncancer patients had any eIF4E gene amplification (1.1+/-0.5). In the 12 HNSCC specimens examined for the three zones, the tumor core and transition zone showed eIF4E gene amplification (5.2+/-1.1 and 3.5+/-0.9, respectively) compared with the "tumor-free" margin (2.1+/-1.1; P < .05). The tumor core and transition zone showed significant efF4E protein elevation (15.5+/-9.3, 4.4+/-4.6, respectively) compared with the "tumor-free" margin (0.9+/-0.5, P < .05). CONCLUSIONS: The eIF4E gene is amplified and overexpressed in HNSCC. Amplification and elevation of eIF4E were highest in the tumor core, intermediate in the transition zone, and lowest in the tumor-free margin. There appears to be progression of eIF4E gene amplification and overexpression from the "tumor-free" margin to the tumor core.

Blotting, Western↗

PubMed1999

Radiotherapy with and without chemotherapy after breast conservation surgery for early stage breast cancer: a review of timing.

PURPOSE: To evaluate the effects in women of the timing of breast irradiation (BI) in relation to the application or non-application of adjuvant chemotherapy after breast conservation surgery (BCS) for early stage cancer. METHODS: Between October 1981 and June 1995, 47 women with stage I and II breast cancer underwent BCS. Twenty-six patients did not receive adjuvant chemotherapy (NAC) and 21 women did (AC). In the NAC group, BI commenced within (n = 9) or after (n = 17) seven weeks following BCS; in the AC group, 18 women received BI more than 24 weeks after BCS and three patients within 24 weeks. RESULTS: In the NAC group, there was a trend toward more local and systemic failures plus a definite correlation with poorer survival (p = 0.05) when BI was initiated more than 7 weeks after BCS. In the AC group, the locoregional and systemic failures occurred only in women with a delay of BI exceeding 24 weeks; survival was not different between the subgroups. CONCLUSION: An undue delay of BI should be avoided in patients after BCS whether they require adjuvant chemotherapy for early stage breast cancer or not.

Age Factors↗

PubMed1998

Clinical outcome in stage I to III breast carcinoma and eIF4E overexpression.

OBJECTIVE: The objective of this study is to determine if high eukaryotic initiation factor 4E (eIF4E) overexpression (sevenfold elevation or more over benign breast tissue) is associated with a worse clinical outcome. SUMMARY BACKGROUND DATA: Dysregulation of cellular functions by selective overexpression of specific proteins can lead to malignant transformation. The overexpression of eIF4E preferentially increases translation of mRNAs with long, G-C rich 5'-untranslated regions. Selective gene products, such as tumor neoangiogenic factors, ornithine decarboxylase, and cyclin D1, are upregulated. METHODS: One hundred fourteen breast specimens were analyzed and eIF4E overexpression was quantified by Western blot analysis. Quantification for eIF4E protein level was accomplished using a rabbit anti-eIF4E antibody and colorimetric development of Western blots using nitro blue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate. The blots were scanned and analyzed by densitometry. Treatment, pathologic, and clinical outcome data variables were analyzed. Statistical analysis was performed to determine if eIF4E overexpression is associated with breast cancer clinical outcome. RESULTS: In the 55 benign specimens, the mean eIF4E expression was 1.1+/-0.4 fold (mean +/- standard deviation). All 59 malignant breast carcinoma specimens were noted to have eIF4E overexpression (range, 1.9-fold to 30.6-fold), with a mean overexpression of 10.8+/-6.3-fold. The mean level of eIF4E expression in malignant specimens was higher than benign specimens (p < 0.05, unpaired t test). The degree of eIF4E overexpression appears to be independent of T and N stage. In the 21 patients with eIF4E overexpression of less than sevenfold, there was one cancer recurrence but no cancer-related deaths. In the 38 patients with high eIF4E overexpression (sevenfold or more), 14 patients had breast cancer recurrences (p = 0.03, log rank test), of whom 11 have died from the disease (p = 0.04, log rank test). The average follow-up interval in this study was 40 months. CONCLUSIONS: Patients with stage I to III breast cancer and high eIF4E overexpression had a higher rate of cancer recurrence and a higher rate of cancer-related death when compared to similar-stage breast cancer patients with low eIF4E overexpression. Therefore, eIF4E protein overexpression may be of prognostic value in stage I to III breast carcinoma.

Blotting, Western↗

PubMed1998

Cystic neoplasms of the pancreas--a review.

Cystic neoplasms of the pancreas are rare entities, representing approximately 5% to 10% of all pancreatic malignancies. Seventy-five percent to 90% of all cystic lesions of the pancreas are pancreatic pseudocysts. Thus cystic neoplasms of the pancreas can be easily misdiagnosed and inappropriately treated by drainage. A persistent cystic lesion in the pancreas may pose a considerable diagnostic and therapeutic dilemma for the practicing clinician. This article reviews the various cystic neoplasms of the pancreas and their distinction from pancreatic pseudocysts.

Cystadenocarcinoma, Mucinous↗

PubMed1997

Elevated expression of eIF4E and FGF-2 isoforms during vascularization of breast carcinomas.

The translation initiation factor eIF4E is a novel protooncogene found over expressed in most breast carcinomas (Kerekatte et al., 1995), but the pathology where this elevation is initially manifested and its possible role in cancer progression are unknown. We report that eIF4E is markedly increased in vascularized malignant ductules of invasive carcinomas, whereas necrotic and avascular ductal carcinomas in situ display significantly lower levels. eIF4E facilitates the synthesis of FGF-2, a powerful tumor angiogenic factor. Conversely, reducing eIF4E with antisense RNA in MDA-435 cells suppresses their tumorigenic and angiogenic properties, consistent with loss of FGF-2 synthesis. These findings suggest a causal role for eIF4E in tumor vascularization.

Animals↗

PubMed1997

Detection of the proto-oncogene eIF4E in surgical margins may predict recurrence in head and neck cancer.

Head and neck squamous cell cancers (HNSCC) have a high local recurrence rate due to incomplete tumor resection. The use of molecular markers to establish surgical margins may decrease local recurrence. Surgical margins are determined by histopathologic analysis on frozen sections. We postulate that genetic and molecular changes precede gross histologic alterations. Tumor markers may improve the reliability of pathology examination, but those evaluated to date lack the sensitivity needed for routine clinical use. Western blot analysis showed elevated eIF4E in all 26 HNSCC in contrast to its low expression in benign lesions. Surgical margins were analysed for eIF4E in 23 patients. Twelve patients showed elevated eIF4E in histologically negative margins. Cancer has recurred in 5 of the 12 patients as opposed to none of the 11 patients with eIF4E negative margins (P= 0.02, Log rank test). This is the first report of eIF4E in HNSCC, as a sensitive and specific marker for HNSCC, with potential for defining clear resection margins. The correlation between elevated levels of eIF4E at the margins and recurrence highlights its ability to detect malignant cells prior to clear-cut alterations in morphology. The accuracy and simplicity of these assays underscore the usefulness of eIF4E in managing HNSCC.

Aged↗

PubMed1997

Overexpression of eukaryotic initiation factor 4E (eIF4E) in breast carcinoma.

BACKGROUND: Eukaryotic initiation factor 4E (eIF-4E) is a 25-kilodalton phosphoprotein that binds specifically to mRNA as the initial step for mRNA translation. An elevated level of eIF4E has been associated with the up-regulation of various protooncogene products. Transfection of cell lines by viral vectors with eIF4E overexpression has resulted in malignant transformation. The objective in this study was twofold: to examine benign and malignant breast specimens for eIF4E expression, and to determine whether eIF4E overexpression may have prognostic potential. METHODS: Western blot analysis was performed on benign and malignant breast specimens using anti-eIF4E rabbit antiserum. Quantification was accomplished by developing blots with nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate and densitometry. Confirmation of eIF4E overexpression at the cellular level was performed using immunohistologic staining in situ. RESULTS: The authors examined 112 breast specimens for eIF4E protein expression. Of the 52 benign breast specimens examined, none showed eIF4E overexpression. All 12 ductal carcinoma in situ specimens were found to overexpress eIF4E in the intermediate range (mean elevation: 2.5-fold). Of the 48 breast carcinoma specimens examined, all had eIF4E elevation at levels of 3-30-fold (mean: 10.5 +/- 0.9-fold). Charts from 39 patients with Stage I, II, and III breast carcinoma were reviewed. In ten patients with eIF4E overexpression of < sevenfold, there was no recurrence or death from breast carcinoma. In the 29 breast carcinoma patients with > or = 7-fold eIF4E overexpression, 9 patients had breast carcinoma recurrences and 5 had died from disease at last follow-up. The median follow-up in this study was 34.5 months. CONCLUSIONS: Overexpression of eIF4E was observed in malignant breast specimens but not in normal or benign breast tissues. In patients with breast carcinoma, the group with high eIF4E overexpression (> or = 7-fold) experienced a worse clinical outcome (higher recurrences and death) compared with the group with low eIF4E overexpression (< 7-fold).

Blotting, Western↗

PubMed1997

Management of the incidentally discovered adrenal mass or "incidentaloma".

The prevalence of an incidentally discovered adrenal mass or "incidentaloma" by abdominal computerized tomography (CT) scan is 1% to 2%. The majority of patients with incidentalomas do not have clinical manifestations nor require further treatments of their incidentalomas. Thus the goal for their management is two-fold: 1) To identify and treat the hormonally hyperactive adrenal adenoma and the rare adrenal carcinoma, and 2) To avoid creating an iatrogenic disease of medical progress. An adrenal mass > or = 6 cm, excluding metastatic malignant disease, needs to be surgically resected due to the risk for carcinoma. The risk of primary adrenal cancer for a hormonally inactive lesion < or = 3 cm is extremely low and can be safely observed. Treatment for the hormonally inactive lesion between 3 and 6 cm must be individualized, based on age, specific scan characteristics (irregular border, local invasion, metastasis), and clinical status of the patient. All hormonally active adrenal adenomas should be surgically resected. In this article, we review the data to support the above recommendations.

Adenoma↗

PubMed1995

Quantifying c-myc expression in c-myc antisense phosphorothioate oligodeoxynucleotide-treated leukemic and colon cancer cell lines.

Antisense oligodeoxynucleotides (oligo) have been used to inhibit oncogene expression and have potential therapeutic applications. Using a 15-mer antisense phosphorothioate oligo (S-oligo), inhibition of c-myc oncogene expression and cellular proliferation is studied in two cell lines with c-myc overexpression: a colon cancer cell line (Colo 320 DM) and a promyelocytic leukemic cell line(HL-60). Quantitative analysis of c-myc mRNA transcript is performed by competitive reverse transcription-polymerase chain reaction (RT-PCR). This utilizes an RNA competitive reference standard (CRS RNA) template that is identical to the native c-myc mRNA except for a short segment deletion to allow for differentiation of the two by gel electrophoresis. A fixed quantity of test mRNA and a series of known concentrations of CRS RNA template placed in the same test tubes under identical conditions are reverse transcribed and amplified by PCR. Since the reaction is competitive, the ratio of the PCR products reflects the ratio of the initial concentrations of the two templates. After gel electrophoresis, the two PCR products are quantified densitometrically. Treating Colo 320 DM and HL-60 cells with c-myc antisense oligo and S-oligo results in a 20- to 100-fold decrease in c-myc mRNA transcripts, respectively. This inhibition is dose dependent and sequence specific (c-myc sense and missense oligo have no effects). The quantitative decrease in c-myc mRNA is associated with corresponding inhibition of c-myc oncoprotein synthesis as demonstrated by flow cytometry and Western blots. Furthermore, there is inhibition of cellular proliferation of the respective cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗

PubMed1994

Detection of HER-2/neu oncogene amplification in flow cytometry-sorted breast ductal cells by competitive polymerase chain reaction.

BACKGROUND: The amplification and/or overexpression of the HER-2/neu oncogene has been proposed as an important prognostic marker in breast cancer. However, contradictory results from various groups regarding whether there is statistical significance in HER-2 amplification or overexpression in predicting overall and disease free survival in node positive versus node negative patients exist in the literature. Current assays on quantifying the HER-2 oncogene rely on DNA extracted from homogenized breast tissue. Not only is a large amount of tissue required, but also, the DNA extract is contaminated with DNA from stromal cells and leukocytes, leading to decreased specificity and sensitivity of the HER-2 assay. Improving the specificity (DNA from breast ductal cells) and the sensitivity (competitive polymerase chain reaction [PCR]) of the HER-2 amplification detection assay will help resolve some of these controversies. METHODS: Using multiparameter flow cytometry (FCM), ductal cells from breast biopsies and fine needle aspirations (FNAs) are identified and selectively sorted using anti-cytokeratin, anti-HER-2 antibody labeling and DNA staining. HER-2 amplification in these sorted cells is then quantified by competitive DNA PCR using a competitive reference standard mutant template that is susceptible to the restriction enzyme Sma-1. RESULTS: Applying this strategy, SK-BR-3, an HER-2 amplified breast cancer cell line, was found to have approximately 9x baseline HER-2 oncogene copies. In addition, MCF-7, a known HER-2 nonamplified breast cancer cell line, was found to have baseline HER-2 oncogene copies. In the 10 clinical breast samples tested, 4 of the 10 breast cancers were HER-2 amplified using as few as 1000 cells. The cytokeratin positive cells of these cancers, in contrast to the cytokeratin negative cells, have detectably higher HER-2 amplification (7.2 +/- 2.8x versus 3.2 +/- 1.1x, respectively). Hence, HER-2 gene amplification would have been underestimated if unsorted cells were used because of stromal dilution. In the cytokeratin positive cells that were HER-2 oncogene amplified, corresponding HER-2 oncoprotein overexpression was detected by FCM. CONCLUSIONS: Using FCM, the ductal cell subpopulation of a breast specimen can be successfully sorted from breast biopsy and FNA specimens. Moreover, by applying the technique of competitive PCR, improved specificity and sensitivity in HER-2 oncogene amplification detection is achieved. The entire procedure can be accomplished in 1 day, allowing for a cost-effective assay and rapid turnaround time.

Base Sequence↗