Interleukin-1beta expression in the pineal gland of the rat

Increasing evidence of the neuroimmunomodulatory role of the pineal gland prompted the present study of pineal gland expression of the immunoregulatory cytokine, interleukin (IL)-1beta. IL-1beta was constitutively expressed in the adult gland, with mRNA levels higher in glands collected during the photophase than in those collected during the scotophase of the light:dark cycle. IL-1beta was up-regulated in pineal cultures, after treatment with either norepinephrine (NE) or interferon (IFN)/lipopolysaccharide (LPS). Although both astrocytes and microglia expressed IL-1beta, important differences were found in the cellular expression of this cytokine under in vivo and in vitro conditions. Increased IL-1beta expression by NE ex vivo and the decline in IL-1 expression at night, when NE levels are elevated, can be explained by immunocytochemical data showing that astrocytes are the predominant cell type expressing this cytokine in vivo, whereas IL-1beta-positive cells are predominantly microglia in pineal explants and dispersed cell cultures. These results are consistent with the hypothesis that cytokines secreted by pineal glia (astrocytes and microglia) may have an important regulatory role in the pineal gland.

Psychiatric co-morbidity among male heroin addicts: differences between hospital and incarcerated subjects in Taiwan

AIMS

To examine the differences in psychiatric co-morbidity between hospital and incarcerated groups of heroin addicts in Taiwan.

DESIGN

Life-time prevalence of DSM-III-R-based coexisting psychiatric disorders, including personality disorders, were surveyed.

SETTINGS

A psychiatric hospital and two prisons.

PARTICIPANTS

Two hundred and sixty heroin users who were incarcerated in prisons, and 47 heroin users who voluntarily sought help in a psychiatric hospital were interviewed by board-certified psychiatrists.

MEASUREMENTS

Using two psychometric instruments, the Psychiatric Diagnostic Assessment (PDA) and the Structured Interview for DSM-III-R Personality Disorders (SIPD-R), psychiatric co-morbidity was assessed.

FINDINGS

Different life-time rates of coexisting psychiatric disorders among heroin addicts in different settings were found: 83% of hospital subjects and 66% of incarcerated subjects were diagnosed as having at least one coexisting axis I or II disorder. The most prevalent coexisting DSM-III-R defined axis I disorders were additional substance use disorders (alcohol and methamphetamine), while the axis II disorder was antisocial personality disorder. The hospital group had a significantly higher prevalence rate of mood disorder (p < 0.001), paranoid personality disorder (p < 0.05) and antisocial personality disorder (p < 0.001) than the incarcerated group.

CONCLUSIONS

We suggest that heroin addicts with coexisting psychiatric disorders receive relevant psychiatric treatment. Those with personality disorders, especially the antisocial type, should be considered for specialized therapeutic community programmes instead of incarceration.

The orphan nuclear receptor COUP-TFII is required for angiogenesis and heart development

The embryonic expression of COUP-TFII, an orphan nuclear receptor, suggests that it may participate in mesenchymal-epithelial interactions required for organogenesis. Targeted deletion of the COUP-TFII gene results in embryonic lethality with defects in angiogenesis and heart development. COUP-TFII mutants are defective in remodeling the primitive capillary plexus into large and small microcapillaries. In the COUP-TFII mutant heart, the atria and sinus venosus fail to develop past the primitive tube stage. Reciprocal interactions between the endothelium and the mesenchyme in the vascular system and heart are essential for normal development of these systems. In fact, the expression of Angiopoietin-1, a proangiogenic soluble factor thought to mediate the mesenchymal-endothelial interactions during heart development and vascular remodeling, is down-regulated in COUP-TFII mutants. This down-regulation suggests that COUP-TFII may be required for bidirectional signaling between the endothelial and mesenchymal compartments essential for proper angiogenesis and heart development.

Activation of indices of cell-mediated immunity in bipolar mania

BACKGROUND

Evidence supports that macrophages as well as lymphocytes and their products may be involved in the pathophysiology of psychiatric disorders. Whether patients with bipolar disorder have activation or reduction of immunity during a manic episode remains unclear.

METHODS

The purpose of this case-control study was to investigate the lymphocyte proliferation to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen, and plasma levels of soluble interleukin-2 receptor (sIL-2R) and sIL-6R in patients with bipolar mania (DSM-III-R). The subjects were 23 physically healthy patients with Young Mania Rating Scale (YMRS) scores > or = 26 as well as aged < or = 45 years and 23 age- and gender-matched normal control subjects. The above immune variables were measured in acute mania and consequent remission (YMRS scores < or = 12) among bipolar patients.

RESULTS

The lymphocyte proliferation to PHA and the plasma sIL-2R levels, but not sIL-6R, of bipolar patients were significantly higher in acute mania than in consequent remission. These elevations were not due to differences in medication status. Only in acute mania were the plasma sIL-2R levels of patients significantly higher than control subjects. A positive correlation between the changes of manic severity and plasma sIL-2R levels was observed. Remitted bipolar patients and normal control subjects did not differ in any of these measures.

CONCLUSIONS

Cell-mediated immunity activation in bipolar mania was demonstrated and may be through a specifically state-dependent immune response.

A steroid receptor coactivator, SRA, functions as an RNA and is present in an SRC-1 complex

Nuclear receptors play critical roles in the regulation of eukaryotic gene expression. We report the isolation and functional characterization of a novel transcriptional coactivator, termed steroid receptor RNA activator (SRA). SRA is selective for steroid hormone receptors and mediates transactivation via their amino-terminal activation function. We provide functional and mechanistic evidence that SRA acts as an RNA transcript; transfected SRA, unlike other steroid receptor coregulators, functions in the presence of cycloheximide, and SRA mutants containing multiple translational stop signals retain their ability to activate steroid receptor-dependent gene expression. Biochemical fractionation shows that SRA exists in distinct ribonucleoprotein complexes, one of which contains the nuclear receptor coactivator steroid receptor coactivator 1. We suggest that SRA may act to confer functional specificity upon multiprotein complexes recruited by liganded receptors during transcriptional activation.

Suppression of gene expression by tethering KRAB domain to promoter of ER target genes

Estrogens play an important role in the development and progression of breast cancer. Although estrogen antagonist treatment often results in the arrest or remission of breast cancer growth, most breast cancers recur and become resistant to estrogen ablative therapy. The molecular mechanisms underlying these actions remain largely undefined. It is hypothesized that tumor cells of an advanced stage may develop compensatory pathways to stimulate the expression of estrogen receptor (ER) target genes or downstream events, independent of estrogen action. In this study, we developed a chimeric repressor to turn off ER target genes with the aim of directly investigating the role of ER target genes in tumor progression. The chimeric repressor contains the ER DNA-binding domain that recognizes estrogen response elements (EREs), a Krupple-associated box (KRAB) repressor domain which silences target genes when tethered to their promoter regions and a truncated progesterone ligand-binding domain which responds only to the exogenous synthetic ligand, RU486. The ability of the chimeric repressor to block ER mediated transcription was assessed in transient transfection assays. ER-induced reporter activity was inhibited by the repressor in a dose-dependent manner, with the maximum effect of more than 80% reduction. The inhibitory activity of the chimeric repressor was tightly under the control of RU486. Effective suppression by the repressor on the natural promoter of ER target gene, complement factor 3 (C3), was also observed. The inhibitory activity was specific to ER, since the repressor has no effect on other nuclear receptor systems tested. Furthermore, the repressor could inhibit the 4-hydroxy-tamoxifen (4OH-T)-induced ER activity. Taken together, our results demonstrate that the inducible repressor we have designed could specifically inhibit ER target gene expression in response to an exogenous synthetic ligand. This repressor will provide a useful tool to study the role of ER target genes in breast cancer progression and it may be potentially useful for gene therapy of breast cancer.

Nuclear receptor coactivators: multiple enzymes, multiple complexes, multiple functions

Nuclear receptors are ligand-inducible transcription factors which mediate the physiological effects of steroid, thyroid and retinoid hormones. By regulating the assembly of a transcriptional preinitiation complex at the promoter of target genes, they enhance the expression of these genes in response to hormone. Recent evidence suggests that nuclear receptors act in part by recruiting multiple coregulator proteins which may have specific functions during transcriptional initiation. Liganded receptors recruit members of the SRC family, a group of structurally and functionally related transcriptional coactivators. Receptors also interact with the transcriptional cointegrators p300 and CBP, which are proposed to integrate diverse afferent signals at hormone-regulated promoters. p300/CBP and members of the SRC coactivator family have intrinsic histone acetyltransferase activity which is believed to disrupt the nucleosomal structure at these promoters. Other nuclear receptor coactivators include a member of the SWI/SNF complex, BRG-1, which couples ATP hydrolysis to chromatin remodelling, and the E3 ubiquitin-protein ligases E6-AP and RPF-1. Finally, nuclear receptor coactivators appear to be organized into preformed subcomplexes, an arrangement that may facilitate their efficient assembly into diverse higher order configurations.

COUP-TF upregulates NGFI-A gene expression through an Sp1 binding site

The formation of various tissues requires close communication between two groups of cells, epithelial and mesenchymal cells. COUP-TFs are transcription factors which have been shown to have functions in embryonic development. COUP-TFI is expressed mainly in the nervous system, and its targeted deletion leads to defects in the central and peripheral nervous systems. COUP-TFII is highly expressed in the mesenchymal component of the developing organs. A null mutation of COUP-TFII results in the malformation of the heart and blood vessels. From their expression pattern, we proposed that COUP-TFs regulate paracrine signals important for mesenchymal cell-epithelial cell interactions. In order to identify genes regulated by COUP-TF in this process, a rat urogenital mesenchymal cell line was stably transfected with a COUP-TFI expression vector. We found that NGFI-A, a gene with important functions in brain, organ, and vasculature development, has elevated mRNA and protein levels upon overexpression of COUP-TFI in these cells. A study of the promoter region of this gene identified a COUP-TF-responsive element between positions -64 and -46. Surprisingly, this region includes binding sites for members of the Sp1 family of transcription factors but no COUP-TF binding site. Mutations that abolish the Sp1 binding activity also impair the transactivation of the NGFI-A promoter by COUP-TF. Two regions of the COUP-TF molecule are shown to be important for NGFI-A activation: the DNA binding domain and the extreme C terminus of the putative ligand binding domain. The C-terminal region is likely to be important for interaction with coactivators. In fact, the coactivators p300 and steroid receptor activator 1 can enhance the transactivation of the NGFI-A promoter induced by COUP-TFI. Finally, we demonstrated that COUP-TF can directly interact with Sp1. Taken together, these results suggest that NGFI-A is a target gene for COUP-TFs and that the Sp1 family of transcription factors mediates its regulation by COUP-TFs.

Androgen regulation of the cyclin-dependent kinase inhibitor p21 gene through an androgen response element in the proximal promoter

Androgen is essential for the physiological maintenance of the integrity of prostatic epithelial cells, and castration causes the cells to undergo apoptosis. To study the molecular mechanism of androgen-dependent cell growth, we showed that androgen up-regulates the expression of the cyclin-dependent kinase inhibitor p21 (WAF1, CIP1, SDI1, CAP20) gene at both the mRNA and protein levels. Nuclear run-on assays demonstrated that androgen stimulates endogenous p21 gene expression at the transcriptional level. Transient transfection experiments showed that androgen can enhance the activity of a 2.4-kb promoter of the p21 gene linked to a luciferase reporter. These results suggested that a putative androgen response element (ARE), which mediates androgen response to enhance the p21 transcription, is included in the 2.4-kb promoter fragment. Deletion analysis of the promoter revealed a functional ARE (AGCACGCGAGGTTCC) located at -200 bp of the p21 gene proximal to the promoter region. Electrophoretic mobility shift assay further demonstrated that the androgen receptor specifically binds to this element. Wild-type ARE, but not mutant ARE, confers androgen responsiveness to a heterologous promoter. The up-regulation of p21 gene expression by androgen suggests that p21 may have an antiapoptotic function in prostatic epithelial cells. However, this hypothesis will need to be tested in future experiments.

The Angelman syndrome-associated protein, E6-AP, is a coactivator for the nuclear hormone receptor superfamily

In this study, we found that the E6-associated protein (E6-AP/UBE3A) directly interacts with and coactivates the transcriptional activity of the human progesterone receptor (PR) in a hormone-dependent manner. E6-AP also coactivates the hormone-dependent transcriptional activities of the other members of the nuclear hormone receptor superfamily. Previously, it was shown that E6-AP serves the role of a ubiquitin-protein ligase (E3) in the presence of the E6 protein from human papillomavirus types 16 and 18. Our data show that the ubiquitin-protein ligase function of E6-AP is dispensable for its ability to coactivate nuclear hormone receptors, showing that E6-AP possesses two separable independent functions, as both a coactivator and a ubiquitin-protein ligase. Disruption of the maternal copy of E6-AP is correlated with Angelman syndrome (AS), a genetic neurological disorder characterized by severe mental retardation, seizures, speech impairment, and other symptoms. However, the exact mechanism by which the defective E6-AP gene causes AS remains unknown. To correlate the E6-AP coactivator function and ubiquitin-protein ligase functions with the AS phenotype, we expressed mutant forms of E6-AP isolated from AS patients and assessed the ability of each of these mutant proteins to coactivate PR or provide ubiquitin-protein ligase activity. This analysis revealed that in the majority of the AS patients examined, the ubiquitin-protein ligase function of E6-AP was defective whereas the coactivator function was intact. This finding suggests that the AS phenotype results from a defect in the ubiquitin-proteosome protein degradation pathway.

Adenovirus-mediated regulable target gene expression in vivo

To regulate expression of a transferred gene in response to an exogenous compound, we have combined a high capacity adenoviral vector devoid of all viral coding sequences with a regulatory system that can be used to express a target gene in vivo in a selected site and at a desired time. This system uses a chimeric transactivator, GLp65, which consists of a mutated progesterone receptor-ligand binding domain fused to the GAL4 DNA binding domain and part of the activation domain of the human p65 protein, a component of the NF-kappaB complex. In the presence of the antiprogestin mifepristone, this chimeric regulator binds to a target gene containing the 17-mer GAL4 binding site, resulting in an efficient ligand-inducible transactivation of the target gene. We inserted the regulator GLp65 and a regulable human growth hormone target gene containing the 17-mer GAL4 binding site into the same adenoviral vector. To obtain tissue-specific expression of the target gene, we coupled the regulator to a liver-specific promoter. Infection of HepG2 cells and experimental mice with the adenovirus resulted in consistently high induction levels of human growth hormone in the presence of mifepristone whereas the transgene expression was undetectable in the absence of the ligand. Taken together, our regulable adenoviral vector represents an important tool for transgene regulation that can be used for potentially diverse applications, ranging from tissue-specific gene expression in transgenic animals to human gene therapy.

Characteristics and psychosocial problems of patients with bipolar disorder at high risk for suicide attempt

BACKGROUND

Bipolar disorder with a history of substance abuse or suicide attempt is a strong predictor of suicide. A high comorbidity of substance use disorders may obscure the specificity of findings about suicide behaviors in Western patients with bipolar disorder.

METHODS

The clinical data of Chinese bipolar patients (DSM-III-R) in Taiwan who had been naturalistically followed up for at least 15 years were obtained by a combination of chart reviews and interviews with patients and family members. The national identity numbers were used to search for deceased subjects.

RESULTS

There were 158 patients originally included for chart review; 4 of them died from suicide. A 9.9% lifetime prevalence of alcohol use disorders was found in 101 final subjects who accepting interview. Multiple logistic regression showed that subjects with a history of suicide attempt (n = 53, 52.5%) were more likely to have interpersonal problems with spouse or romantic partner (adjusted odds ratio = 2.85, 95% C.I. = 0.69-11.51), occupational problems mainly maladjustment and frequently changing job (adjusted odds ratio = 3.08, 95% C.I. = 1.12-10.49), and an earlier age (< or = 22 years) of onset (adjusted odds ratio = 0.96, 95% C.I. = 0.90-1.02).

LIMITATION

To use an interview schedule for assessing the psychosocial problems of clinical population limits the interpretation and generalisability of the data.

CONCLUSION

Despite low comorbidity of alcohol/drug use disorders in Chinese bipolar patients, a consistently high rate of suicide attempts reinforces that bipolar disorder is a high-risk group of suicide. An earlier age of onset, interpersonal problems with spouse or romantic partner, and occupational maladjustment rather than demographic characteristics may collectively identify those at high risk of suicide attempt in bipolar disorder.

Distinct steady-state nuclear receptor coregulator complexes exist in vivo

Transcriptional regulation by members of the nuclear hormone receptor superfamily is a modular process requiring the mediation of distinct subclasses of coregulators. These subclasses include members of the steroid receptor coactivator-1 (SRC-1) coactivator family, p300/CBP and their associated proteins, such as p300/CBP-associated factor, human homologs of SWI/SNF proteins such as BRG-1, and the less well-characterized E3 ubiquitin-protein ligases E6 papillomavirus protein-associated protein and receptor-potentiating factor-1. Because functional studies indicate that these coregulators may form higher order complexes, we analyzed steady-state complexes of different coregulator subclasses in vivo. T47D and HeLa cell lysates were subjected to biochemical fractionation and screened by immunoblotting using coregulator-specific antibodies. We show that different subclasses of nuclear receptor coregulators exhibit distinct fractionation profiles. Furthermore, evidence is provided that SRC-1 family members may exist in vivo in heteromultimeric forms with each other. In addition, we demonstrate that liganded PR is present in stable complexes containing SRC-1 and transcription intermediary factor 2 (TIF2) in vivo. Our results suggest that the assembly of large, modular transcriptional complexes by recruitment of distinct subclasses of preformed coregulator subcomplexes may be involved in transcriptional regulation by activated nuclear receptors.

Immunogenicity and safety of Haemophilus influenzae type b conjugate vaccine (HibTITER) and a combination vaccine of diphtheria, tetanus, pertussis and HibTITER (TETRAMUNE) in two-month-old infants

A study was undertaken to evaluate the safety and immunogenicity of a combination vaccine (TETRAMUNE) of conjugate Haemophilus influenzae type b (Hib) vaccine (HibTITER) and DTP (Diphtheria, Tetanus and Pertussis) vaccine. A total of 93 healthy children were randomized to receive either TETRAMUNE (combined group), or DTP and HibTITER administered concurrently (separate group) in separate syringes at approximately 2, 4 and 6 months of age in Taiwan. Serologic responses were largely comparable between the two vaccine groups; almost all subjects were seropositive to Hib PRP (polyribosylribitol phosphate) and were protected against diphtheria and tetanus after 2 doses of vaccine and mounted prominent responses to the components of Bordetella pertussis. Subjects in the combined group did not experience more adverse reactions compared with those in the separate group. We concluded that HibTITER was highly immunogenic and safe when administered concurrently with DTP vaccine to Taiwanese children. TETRAMUNE was also safe and immunogenic and might reduce the number of injections to achieve the same protection.

Prognostic features and treatment outcome in locoregionally advanced nasopharyngeal carcinoma following concurrent chemotherapy and radiotherapy

PURPOSE

Concurrent chemotherapy and radiotherapy (CCRT) are effective in treatment of locoregionally advanced nasopharyngeal carcinoma (NPC). However, the prognostic factors after CCRT have not been evaluated. We therefore attempt to evaluate factors that influence treatment outcomes following CCRT.

METHODS AND MATERIALS

Seventy-four (5 in stage III and 69 in stage IV) patients with locoregionally advanced NPC were treated with CCRT. Radiotherapy was delivered either at 2 Gray (Gy) per fraction per day up to 70 Gy or 1.2 Gy, 2 fractions per day, up to 74.4 Gy. Concurrent chemotherapy consisted of cisplatin and 5-fluorouracil. Cox proportional-hazards model was used to analyze the prognostic factors which included age, gender, pathologic type, T, N, lactate dehydrogenase (LDH), and infiltration of the clivus.

RESULTS

The primary tumor control rate at 3 years was 96.7% (95% confidence interval [CI]: 92.5-100), distant metastasis-free survival 81.1% (95% CI: 70.6-91.6), disease-free survival 77.0% (95% CI: 65.3-88.7), and overall survival 79.8% (95% CI: 69.2-90.4) with a median follow-up interval of 29 months (range 15-74 months). Cox proportional-hazards model revealed that infiltration of the clivus and serum level of LDH before treatment were the most two important factors that predict distant metastases. Infiltration of the clivus and the serum LDH level greater than 410 U/L were strongly associated with distant metastasis-free survival (p = 0.0004 and p = 0.0002, respectively). When these two risk factors were considered together, no distant metastasis was observed in 40 patients with both intact clivus and LDH < or = 410 U/L. On the contrary, 13 of the remaining 34 patients with at least one risk factor developed distant metastasis (p = 0.0001).

CONCLUSION

Our study demonstrates that CCRT can improve the primary tumor control of 96.7% and disease-free survival of 77.0% at 3-year follow-up. Distant metastasis, however, is the major cause of failure. Infiltration of the clivus by the tumor and LDH greater than 410 U/L are the two independent and useful prognostic factors in patients with locoregionally advanced NPC who were treated with CCRT. Good- and poor-risk patients can be distinguished by virtue of their having both conditions.

The steroid receptor coactivator-1 contains multiple receptor interacting and activation domains that cooperatively enhance the activation function 1 (AF1) and AF2 domains of steroid receptors

Steroid receptors are ligand-inducible transcription factors, and their association with steroid receptor coactivators (SRCs) upon binding to DNA is necessary for them to achieve full transcriptional potential. To understand the mechanism of SRC-1 action, its ability to interact and enhance the transcriptional activity of steroid receptors was analyzed. First, we show that SRC-1 is a modular coactivator that possesses intrinsic transcriptional activity when tethered to DNA and that it harbors two distinct activation domains, AD1 and AD2, needed for the maximum coactivation function of steroid receptors. We also demonstrate that SRC-1 interacts with both the amino-terminal A/B or AF1-containing domain and the carboxyl-terminal D/E or AF2-containing domain of the steroid receptors. These interactions are carried out by multiple regions of SRC-1, and they are relevant for transactivation. In addition to the inherent histone acetyltransferase activity of SRC-1, the presence of multiple receptor-coactivator interaction sites in SRC-1 and its ability to interact with components of the basic transcriptional machinery appears to be, at least in part, the mechanism by which the individual activation functions of the steroid receptors act cooperatively to achieve full transcriptional activity.

Drug inducible transgene expression in brain using a herpes simplex virus vector

The ability to regulate transgene expression is likely to be important in the use of gene transfer to treat diseases of the central nervous system (CNS). In order to achieve regulatable gene expression we created a replication-incompetent genomic herpes simplex vector containing a RU486-inducible transactivator and a lacZ reporter gene under transcriptional control of a minimal promoter. Reporter gene expression from the vector was regulated by administration of RU486 in vitro and in vivo. In cell culture half maximal expression was achieved with 10(-8) M RU486, and maximal expression was achieved by 24 h. Following stereotactic inoculation of the vector into rat hippocampus, expression was increased 150-fold by i.p. administration of RU486. This demonstrates that the RU486 system functions as a tight on/off switch for regulating expression of a transgene delivered to the brain via an HSV vector.

Partial hormone resistance in mice with disruption of the steroid receptor coactivator-1 (SRC-1) gene

The in vivo biological function of a steroid receptor coactivator was assessed in mice in which the SRC-1 gene was inactivated by gene targeting. Although in both sexes the homozygous mutants were viable and fertile, target organs such as uterus, prostate, testis, and mammary gland exhibited decreased growth and development in response to steroid hormones. Expression of RNA encoding TIF2, a member of the SRC-1 family, was increased in the SRC-1 null mutant, perhaps compensating partially for the loss of SRC-1 function in target tissues. The results indicate that SRC-1 mediates steroid hormone responses in vivo and that loss of its coactivator function results in partial resistance to hormone.

A novel RU486 inducible system for the activation and repression of genes

We have developed an inducible system that consists of a transactivator and a target gene. The transactivator encodes a chimeric regulator that is responsive to RU486 (mifepristone, a progesterone receptor antagonist) but not to progestins and other hormones or endogenous ligands for activation. The target gene can be any gene under the control of Gal4 DNA binding sites. When the regulator is activated by RU486, it induces target gene expression by binding to the Gal4 recognition sequences upstream of the target. To verify this concept, we have successfully demonstrated the functionality of this system in tissue culture and in transgenic mice. Furthermore, for applications that require higher levels of a target gene, we also have generated regulators that can induce greater target gene expression. In addition, we also have constructed a modified regulator which can repress gene expression. The versatility of our system should prove useful for many applications in biology and gene therapy.

The benefit and risk of postmastectomy radiation therapy in patients with high-risk breast cancer

To evaluate the efficacy of postmastectomy radiation therapy (PMRT) for prophylaxis against locoregional recurrence in high-risk breast cancer patients, and the rate of complication associated with such treatment, we retrospectively reviewed 79 breast cancers in 78 patients, who were given therapy (PMRT) between April 1990 and March 1995. Radiation doses were 46-50 Gy in 2-Gy fractions. High-risk factors included primary tumor (> or = 5 cm) in 19 (24.1%) patients, positive axillary lymph nodes (> or = 4) in 56 (70.9%) patients, positive or close (< or = 2 mm) surgical margins in 14 (17.7%) patients, and central or inner quadrant tumor with positive axillary nodes and lymphovascular invasion in seven (8.9%) patients. Adjuvant chemotherapy was also given to 69 of 78 (88.5%), patients and hormonal therapy to 41 of 78 (53.7%) patients. The median follow-up time was 25 months (range, 7-66 months) after mastectomy. Our study revealed that locoregional failure as the first site of failure occurred in only one of 78 (1.3%) patients. Relapse-free survival at 3 years was 67.7% [95% confidence interval (CI), 52.0-81.3], and overall survival was 76.9% (95% CI, 63.3-90.6). The incidence of radiological evidence of lung fibrosis increased significantly in patients whose internal mammary chain was included in the radiation field. The occurrence of lung fibrosis can be reduced by changing radiation treatment technique and keeping central lung distance (CLD) of tangential field to < or = 2.8 cm in tangential field technique or < or = 1.4 cm in tangential with a separate internal mammary field technique. We concluded that the risk of locoregional recurrence in high-risk breast cancer patients can be much reduced by PMRT. With careful selection of radiation treatment fields, radiotherapy technique, and limitation of CLD to < or = 2.8 cm in tangential technique or < or = 1.4 cm in separate technique, the risk of symptomatic radiation pneumonitis is minimal. PMRT should be recommended for breast cancer patients who are at high risk for locoregional recurrence.

T classification and clivus margin as risk factors for determining locoregional control by radiotherapy of nasopharyngeal carcinoma

BACKGROUND

The purpose of this study was to determine risk factors that affect locoregional control of nasopharyngeal carcinoma (NPC) after radiotherapy. Computed tomography (CT) is utilized for radiotherapy planning and for identifying high risk anatomic areas.

METHODS

Between April 1990 and December 1993, 40 consecutive patients (1 in Stage I, 3 in Stage II, 5 in Stage III, and 31 in Stage IV) who had locoregional NPC were given definitive radiotherapy at the Koo Foundation Sun Yat-Sen Cancer Center in Taipei, Taiwan. All patients had individualized CT treatment planning. The dimension of each tumor as shown on the treatment planning CT were mapped on conventional simulation films. The extent of each tumor was further affirmed by magnetic resonance imaging (MRI) and the tumor map revised as necessary. The primary radiation fields were designed to include the primary tumor and potential spread areas with appropriate margins. Concurrent chemotherapy was also given to 35 patients (87.5%) who had positive cervical lymph nodes or primary tumors extending beyond the nasopharynx.

RESULTS

By the end of December 1995, after a median follow-up of 42 months and minimal follow-up of 24 months, the locoregional control rate at 4 years was 84.8% (95% confidence interval [CI], 72.3-97.3), disease free survival 68.4% (95% CI, 52. 1-84.7), and overall survival 76.7% (95% CI, 63.4-90.0). The radiation field margin near the sphenoid sinus averaged 1.9 cm, the clivus margin 1.1 cm, the pterygoid fossa margin 2.0 cm, and the oral cavity margin 1.7 cm. Risk factor analysis revealed that T classification and the radiation field margin at the clivus were the most important factors for locoregional control of the tumor. The locoregional control rates were 92.6% (25/27) for T1-T3 patients and 76.9% (10/13) for T4 patients (P = 0.03). The locoregional control rates were 71.4% (5/7) for patients with a clivus margin < 1 cm and 90.6% (29/32) for patients with a clivus margin > or = 1 cm (P = 0.08).

CONCLUSIONS

The excellent locoregional control observed in this series may be attributed to the concurrent chemotherapy and radiotherapy as well as meticulous treatment planning with CT and MRI. The precise delineation of the involved area with the aid of CT, which is taken while the patient is in the position for irradiation, serves to define the necessary safety margin of the radiation field. T classification and clivus margin are the most important factors in determining locoregional control of radiotherapy of NPC. The statistical trend observed in this study indicated that the clivus margin should be adequate to reduce the failure around the clivus, as all local recurrences were observed in this area.

A regulatory system for target gene expression

Temporally-regulated expression of endogenous genes is a desirable goal in stable cell line and transgenic animal systems, as well as in clinical gene therapy. Protocols for introducing genes into stable cell lines and experimental animals are often unsatisfactory due to the constitutive expression of such transgenes. To circumvent this problem we have demonstrated specific and temporally regulable expression of a target gene in vivo effected by a chimeric regulator in response to an orally-administered, non-toxic chemical. This regulatory system utilizes a chimeric regulator GLVP, consisting of a mutated human progesterone receptor ligand binding domain (PRLBD-delta) fused to the yeast GAL4 DNA binding domain (DBD) and the HSV VP16 transcriptional activation domain and whose activity is solely regulable by non-physiological doses of RU486 but not by progesterone or other endogenous progestins. Replacing the activation domain of the chimeric regulator with a transcriptional repression domain results in inducible repression of target gene expression in vitro. Our regulatory system functions in transient and stable transfections as well as in transgenic animals, and will have a wide variety of potential applications.

Preoperative concurrent chemotherapy and radiotherapy in rectal cancer patients

The management of rectal cancer has changed significantly in recent years. The key end-point is no longer survival but rather preservation of sphincter function with improved quality of life. Preoperative radiation can not only render a low-lying rectal tumor amenable to sphincter-preserving surgery but has also been reported to give better local control and lower toxicity than postoperative radiotherapy. From October 1991 through July 1996, 46 patients with local advanced or low-lying rectal cancer were treated with preoperative high-dose radiotherapy and concurrent chemotherapy. All patients underwent pelvic radiotherapy with 5,000 to 5,400 cGy in 25 to 27 fractions. Chemotherapy was given concomitantly and consisted of two courses of 5-fluorouracil (5-FU) at 1,000 mg/m2 for 4 days in week 1 and week 5 plus mitomycin C 10 mg/m2 single bolus on day 1 of week 1. In 30 patients, postoperative adjuvant chemotherapy with 5-FU and levamisole weekly was also given, for a total of 12 months. The most common acute toxicity was grade 1 to 2 diarrhea and tenesmus during radiation or soon afterward. Only five of the 46 patients experienced symptomatic grade 3 acute toxicity. Forty-two patients underwent subsequent surgery 6 to 8 weeks after concurrent chemoradiotherapy. Pathologic examination disclosed complete tumor regression in eight patients and microscopic residual disease in 13 patients after preoperative chemoradiation. Of the 42 patients who completed the intended treatments, only one had local recurrence. The sphincter was preserved in 21 of the 26 patients in whom the tumor was located within 5 cm above the anal verge. Twelve of the 16 evaluable patients had good to excellent sphincter function. The 2-year overall survival rate was 93% and the disease-free survival was 81%. Our findings indicate that preoperative concurrent chemoradiotherapy not only allows low-lying rectal tumors to be resected while preserving sphincter function but also results in good local control and acceptable toxicity.

Mediation of Sonic hedgehog-induced expression of COUP-TFII by a protein phosphatase

A Sonic hedgehog (Shh) response element was identified in the chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) promoter that binds to a factor distinct from Gli, a gene known to mediate Shh signaling. Although this binding activity is specifically stimulated by Shh-N (amino-terminal signaling domain), it can also be unmasked with protein phosphatase treatment in the mouse cell line P19, and induction by Shh-N can be blocked by phosphatase inhibitors. Thus, Shh-N signaling may result in dephosphorylation of a target factor that is required for activation of COUP-TFII-, Islet1-, and Gli response element-dependent gene expression. This finding identifies another step in the Shh-N signaling pathway.