Cyclic AMP-mediated growth arrest is associated with increased expression of human T cell leukemia virus type I structural and transforming genes.

The effect of increased intracellular cyclic AMP levels on gene expression of the human T cell leukemia virus type I (HTLV-I) provirus was examined. Induction of infected cells to produce elevated levels of cyclic AMP was associated with specific increases in viral surface antigen expression, protein synthesis, p24 release into the supernatant, and RNA levels. The patterns of HTLV-I proviral gene expression observed support results from transfection experiments regarding the function of Tax, Rex, and cyclic AMP in HTLV-I gene regulation. As evidenced by thymidine incorporation, treatment of the infected cells to produce cyclic AMP caused reversible growth arrest. The data indicate that HTLV-I RNA and protein synthesis can proceed at an elevated level in the absence of cell growth. Sustained increases in the intracellular level of cyclic AMP may represent a method for enriching cell cultures in HTLV-I proteins.

The utility of patient age in evaluating prostate cancer.

The utility of age in examining patients for prostate cancer was assessed. Of the 462 patients in the study, 138 had prostate cancer. The age distribution of the patients with cancer was similar to that found in patients with prostate cancer in the US population, and a correlation between age and the serum prostate-specific antigen (PSA) value was noted (r = .4, P < .002). Selection of reference intervals had a significant effect on test performance. Using an interval of 0 to 4.0 ng/mL, sensitivity of the PSA assay was 90% overall and varied from 78% (patients aged 50-59 years) to 94% (patients aged 70-79 years). In contrast, age-adjusted reference ranges yielded corresponding sensitivities of 84%, 78%, and 88%. With a single, fixed reference range, specificity decreased with advancing patient age (P < .001). This trend was eliminated by adjusting the cutoff in different age groups. In addition, age-adjusted reference ranges improved specificity by 10%, and by using the results of examination of a biopsy specimen as the "gold standard," the total number of patients classified correctly by PSA increased from 226 to 250 (49%-54%). For staging before treatment, patient age, clinical stage, and Gleason score were combined to yield a single probability estimate for organ-confined disease (P < .001). The use of age-adjusted reference ranges is supported by this study, which demonstrates that assay efficiency and specificity improve and sensitivity, although decreased overall, becomes more uniform across age groups. In this patient population, age was useful in determining the probability of organ-confined prostate cancer. Use of this model in clinical decision making should await evaluation in a prospective trial.

Appropriateness of prostate-specific antigen testing.

We established criteria for appropriate use of the prostate-specific antigen (PSA) assay and used them to evaluate PSA test utilization at 1 tertiary care institution. During a 6-month period, 2,330 PSA results were reported for outpatients and 95 for inpatients. We reviewed medical records for a random sample of 338 outpatient results (14.51%) and all 95 inpatient results, of which 21% (71/338) of outpatient and 17% (16/95) of inpatient results were inappropriate according to our test utilization criteria. Among outpatients, 52% of tests were done for screening and 19% for monitoring for cancer recurrence. For inpatients, workup for cancer (53/95 [56%]) was the most frequent indication for testing and screening the second (24/95 [25%]). Of tests failing the criteria, 66 (76%) of 87 resulted from excessively frequent and age-inappropriate screening. We assessed the potential effect on clinical outcome if these tests were not performed. Of the 87 tests considered inappropriate, only 1 test result influenced clinical management for patients younger than 75 years. By instituting simple limits on age and frequency, we estimate that 74% (64/87) of the inappropriate tests could have been eliminated.

A simplified polymerase chain reaction assay for detection of chromosomal translocations in hematologic malignancies.

The polymerase chain reaction (PCR) is a rapid and highly sensitive method for detection of a variety of chromosomal translocations in malignant tissues. Detection of each different type of translocation, or even DNA rearrangements at different breakpoint cluster regions within the same type of translocation, usually requires separate thermocycling parameters and/or buffer conditions. In this report, we describe a single set of reaction conditions, making use of progressively decreasing annealing temperatures and a standardized reaction buffer, that permits the detection of several different translocations simultaneously. Specificity equal to or better than current procedures and sensitivity equivalent to one malignant cell in 1 x 10(5) normal cells was achieved for translocations t(14;18)(q32;q21), t(9;22)(q34;q11), and t(4;11)(q21;q23). For PCRs formerly requiring different, fixed annealing temperatures, the new technology allows batching or multiplexing of PCR samples. Thus, shorter turnaround time, decreased cost per sample, and simplified mechanization of PCR may be attainable using this assay.

Detection of chromosome 18 rearrangement in synovial sarcoma by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) evaluations of chromosome 18 were performed in synovial sarcoma, hemangiopericytoma, and mesothelioma. Each case was evaluated with centromeric and whole chromosome paint probes. The synovial sarcomas had t(X;18) cytogenetically, but the FISH evaluator was blinded to the cytogenetic results and to the histopathologic diagnosis. The FISH analyses were consistent with chromosome 18 translocation in 6 of 7 synovial sarcomas, 0 of 3 hemangiopericytomas, and 0 of 1 mesothelioma. These findings support the use of FISH in the diagnosis of synovial sarcoma.

Improved screening for breast cancer associated with a telephone-based risk assessment.

BACKGROUND: Our objective was to develop and field-test a telephone-based breast cancer risk assessment and to assess its efficacy in improving screening behavior. The study was performed at a financial institution and a manufacturing corporation with main offices in Boston, Massachusetts, and branch offices in various regions of the United States. METHODS: A longitudinal study consisting of an initial health risk assessment administered by telephone, with a subsequent follow-up study initiated 8 months later, was performed. Study design was influenced by some of the suggestions made by the benefits departments of the corporate sponsors. A voice-response, telephone system collected risk information from callers and gave real-time risk assessment. These callers could receive a risk assessment over the phone and remain completely anonymous or furnish name and address to receive a more detailed written report. Main outcome measures included the response rate and demographics of the respondents, risk profiles of the callers, and breast cancer screening statuses. RESULTS: There were 343 participants of whom 189 relinquished anonymity to receive more detailed information by mail and were available for a follow-up study. Sixty-three women (18%) reported a family history of breast cancer, with 34 women (10%) responding that one first-degree blood relative had been diagnosed before the age of 50. A strong positive correlation between the level of familial risk and the decision to remain anonymous existed (P < 0.0001). There was an increase in compliance with breast self-examination from 34% (40/119) at time of use of the system to 62% (74/119) at follow-up, P < 0.0001. Clinical breast exams showed similar improvements, from 82 (98/119) to 92% (110/119), P < 0.0137. Paired and unpaired data of women 40 years of age and older indicate an improvement in mammography compliance from time of system use to follow-up, 76 (22/29) to 93% (27/29), P < 0.0572, and 79 (33/42) to 93% (27/29), P < 0.0129, respectively. CONCLUSIONS: A population of women with a risk profile higher than that of the U.S. population called the survey. System use is associated with an improvement in breast cancer screening habits. Self-reported, increased genetic risk for breast cancer was strongly correlated with a decision to remain anonymous.

Protein kinase A-dependent binding of a nuclear factor to the 21-base-pair repeat of the human T-cell leukemia virus type I long terminal repeat.

The long terminal repeat (LTR) of the human T-cell leukemia virus type I (HTLV-I) contains an imperfect repeat of 21 nucleotides which governs the response to the virus trans-activator protein tax and to cyclic AMP. In a murine thymocyte cell line defective in the catalytic subunit of protein kinase A, the response of the HTLV-I LTR to cyclic AMP is abolished and the response to tax is substantially diminished. This report shows that a factor present in nuclear extracts of wild-type cells binds to the HTLV-I 21-nucleotide sequence and that this binding activity is missing from the extracts of protein kinase A-defective cells. Treatment of nuclear extracts of protein kinase A-defective cells with the bovine protein kinase A catalytic subunit restores the binding activity, whereas treatment of wild-type nuclear extracts with a protein phosphatase destroys the binding activity. The binding factor is referred to as protein kinase A-dependent factor (PKAF). These results indicate that in murine thymocytes the response of the HTLV-I LTR to cyclic AMP depends upon the binding of a phosphorylated protein to the 21-nucleotide repeat sequence and that the response to tax is partially dependent upon binding of the phosphorylated protein. The results suggest a model in which the phosphorylation of a transcription factor by protein kinase A regulates HTLV-I gene expression.

Role of protein kinase A in tax transactivation of the human T-cell leukemia virus type I long terminal repeat.

The human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR) is inducible both by the retroviral tax gene product and by cyclic AMP in the murine thymoma S49 cell line. The cis-acting sequences that control transcriptional induction by tax and by cyclic AMP are in close proximity within the HTLV-I promoter. By using a protein kinase A (PKA)-deficient S49 mutant cell line, the response of the viral promoter to cyclic AMP was shown to depend on PKA, whereas the response to tax did not require the activity of this enzyme. Transactivation of the HTLV-I LTR by tax, however, decreased in PKA-deficient and adenylate cyclase-deficient cells. The evidence presented supports largely independent mechanisms of promoter induction by cyclic AMP and tax but also suggests a role for PKA-mediated phosphorylation in the regulation of HTLV-I LTR-driven gene expression by tax.

Response of the human T-cell leukemia virus type 1 long terminal repeat to cyclic AMP.

The sequences that control transcriptional initiation of the provirus of the human T-cell leukemia virus type 1 (HTLV-1) are shown to be responsive to intracellular levels of cyclic AMP. A heptanucleotide sequence present within the 21-nucleotide repeat sequence that is similar to the cyclic AMP-responsive consensus (CRE) sequence was required for cyclic AMP-mediated increase in gene expression. Although the CRE-like sequences were contained within sequences that were responsive to the virally encoded trans-activator (tax), the evidence presented indicates that the mechanisms of promoter induction by the tax product and cyclic AMP are independent. The implication of cyclic AMP stimulation of HTLV-1 provirus gene expression for long-term persistence of infected T cells and for virus-induced transformation is discussed.