RNA-seq profiling of a radiation resistant and radiation sensitive prostate cancer cell line highlights opposing regulation of DNA repair and targets for radiosensitization

BACKGROUND

Radiotherapy is a chosen treatment option for prostate cancer patients and while some tumours respond well, up to 50% of patients may experience tumour recurrence. Identification of functionally relevant predictive biomarkers for radioresponse in prostate cancer would enable radioresistant patients to be directed to more appropriate treatment options, avoiding the side-effects of radiotherapy.

METHODS

Using an in vitro model to screen for novel biomarkers of radioresistance, transcriptome analysis of a radioresistant (PC-3) and radiosensitive (LNCaP) prostate cancer cell line was performed. Following pathway analysis candidate genes were validated using qRT-PCR. The DNA repair pathway in radioresistant PC-3 cells was then targeted for radiation sensitization using the PARP inhibitor, niacinimide.

RESULTS

Opposing regulation of a DNA repair and replication pathway was observed between PC-3 and LNCaP cells from RNA-seq analysis. Candidate genes BRCA1, RAD51, FANCG, MCM7, CDC6 and ORC1 were identified as being significantly differentially regulated post-irradiation. qRT-PCR validation confirmed BRCA1, RAD51 and FANCG as being significantly differentially regulated at 24 hours post radiotherapy (p-value =0.003, 0.045 and 0.003 respectively). While the radiosensitive LNCaP cells down-regulated BRCA1, FANCG and RAD51, the radioresistant PC-3 cell line up-regulated these candidates to promote cell survival post-radiotherapy and a similar trend was observed for MCM7, CDC6 and ORC1. Inhibition of DNA repair using niacinamide sensitised the radioresistant cells to irradiation, reducing cell survival at 2 Gy from 66% to 44.3% (p-value =0.02).

CONCLUSIONS

These findings suggest that the DNA repair candidates identified via RNA-seq hold potential as both targets for radiation sensitization and predictive biomarkers in prostate cancer.

Benzimidazoisoquinolines: a new class of rapidly metabolized aryl hydrocarbon receptor (AhR) ligands that induce AhR-dependent Tregs and prevent murine graft-versus-host disease

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that plays multiple roles in regulation of immune and inflammatory responses. The ability of certain AhR ligands to induce regulatory T cells (Tregs) has generated interest in developing AhR ligands for therapeutic treatment of immune-mediated diseases. To this end, we designed a screen for novel Treg-inducing compounds based on our understanding of the mechanisms of Treg induction by the well-characterized immunosuppressive AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We screened a ChemBridge small molecule library and identified 10-chloro-7H-benzimidazo[2,1-a]benzo[de]Iso-quinolin-7-one (10-Cl-BBQ) as a potent AhR ligand that was rapidly metabolized and not cytotoxic to proliferating T cells. Like TCDD,10-Cl-BBQ altered donor CD4⁺ T cell differentiation during the early stages of a graft versus host (GVH) response resulting in expression of high levels of CD25, CTLA-4 and ICOS, as well as several genes associated with Treg function. The Treg phenotype required AhR expression in the donor CD4⁺ T cells. Foxp3 was not expressed in the AhR-induced Tregs implicating AhR as an independent transcription factor for Treg induction. Structure-activity studies showed that unsubstituted BBQ as well as 4, 11-dichloro-BBQ were capable of inducing AhR-Tregs. Other substitutions reduced activation of AhR. Daily treatment with 10-Cl-BBQ during the GVH response prevented development of GVH disease in an AhR-dependent manner with no overt toxicity. Together, our data provide strong support for development of select BBQs that activate the AhR to induce Tregs for treatment of immune-mediated diseases.

Systemic bias in the medical literature on androgen deprivation therapy and its implication to clinical practice

BACKGROUND

LHRH agonists are used for androgen deprivation therapy (ADT) to treat prostate cancer, but have many side effects that reduce of the quality of life of prostate cancer patients and their partners. Patients are poorly informed about the side effects of these drugs and how to manage them.

AIM

To test the hypothesis that there is bias in the peer-reviewed literature on ADT that correlates with an association between authors and the luteinising hormone-releasing hormone (LHRH) agonists pharmaceutical industry.

METHODS

We assessed 155 articles on ADT published in English-language peer-reviewed journals in terms of how comprehensive they were in acknowledging LHRH agonists' side effects.

RESULTS

Although the literature regarding ADT is substantial, the vast majority of articles failed to acknowledge many of the more stressful side effects of ADT for patients and their partners. Articles most likely to acknowledge the psychosocial impact of ADT were significantly less likely to have had industrial support than those articles that did not mention those side effects. Alternative treatments to the LHRH agonists were rarely mentioned. Authors who indicated some association with a pharmaceutical company tended to minimise the side effects of LHRH agonists and not acknowledge alternatives to the LHRH agonists for ADT.

CONCLUSION

Industrial support is associated with a proliferation of articles published in the peer-reviewed literature directed at practising physicians. Such flooding of the literature may, in part, limit physicians' knowledge of the side effects of these drugs and, in turn, account for the poor knowledge that patients on LHRH agonists have about the drugs they are taking and ways to manage their side effects.

Hormones and honest signals: males with larger ornaments elevate testosterone more when challenged

When male investment in mating varies with quality, reliable sexual signals may evolve. In many songbirds, testosterone mediates mating investment, suggesting that signals should be linked to testosterone production. However, because testosterone may change rapidly during behaviour such as territorial aggression and courtship, efforts to establish such a relationship have proved challenging. In a population of dark-eyed juncos, we measured individual variation in the production of short-term testosterone increases by injecting gonadotropin-releasing hormone (GnRH). We found a positive correlation between the magnitude of these increases and the size of a plumage ornament ('tail white') previously shown to be important for female choice and male-male competition. We then measured naturally elevated testosterone levels produced during male-male competition and found that they covaried with those induced by GnRH. We suggest that the association between tail white and testosterone increases may allow conspecifics to assess potential mates and competitors reliably using tail white.

Comment on "The Brain of LB1, Homo floresiensis"

Endocast analysis of the brain Homo floresiensis by Falk et al. (Reports, 8 April 2005, p. 242) implies that the hominid is an insular dwarf derived from H. erectus, but its tiny cranial capacity cannot result from normal dwarfing. Consideration of more appropriate microcephalic syndromes and specimens supports the hypothesis of modern human microcephaly.

The consequences of chromosomal aneuploidy on gene expression profiles in a cell line model for prostate carcinogenesis

Here we report the genetic characterization of immortalized prostate epithelial cells before and after conversion to tumorigenicity using molecular cytogenetics and microarray technology. We were particularly interested to analyze the consequences of acquired chromosomal aneuploidies with respect to modifications of gene expression profiles. Compared with nontumorigenic but immortalized prostate epithelium, prostate tumor cell lines showed high levels of chromosomal rearrangements that led to gains of 1p, 5, 11q, 12p, 16q, and 20q and losses of 1pter, 11p, 17, 20p, 21, 22, and Y. Of 5700 unique targets on a 6.5K cDNA microarray, approximately 3% were subject to modification in expression levels; these included GRO-1, -2, IAP-1,- 2, MMP-9, and cyclin D1, which showed increased expression, and TRAIL, BRCA1, and CTNNA, which showed decreased expression. Thirty % of expression changes occurred in regions the genomic copy number of which remained balanced. Of the remainder, 42% of down-regulated and 51% of up-regulated genes mapped to regions present in decreased or increased genomic copy numbers, respectively. A relative gain or loss of a chromosome or chromosomal arm usually resulted in a statistically significant increase or decrease, respectively, in the average expression level of all of the genes on the chromosome. However, of these genes, very few (e.g., 5 of 101 genes on chromosome 11q), and in some instances only two genes (MMP-9 and PROCR on chromosome 20q), were overexpressed by > or =1.7-fold when scored individually. Cluster analysis by gene function suggests that prostate tumorigenesis in these cell line models involves alterations in gene expression that may favor invasion, prevent apoptosis, and promote growth.

The genetic basis of renal epithelial tumors: advances in research and its impact on prognosis and therapy

The genetics of renal cell carcinoma continues to elucidate the pathways of kidney tumorigenesis. The relationship between the VHL gene and clear cell carcinoma, MET and papillary carcinoma, and the families of genes that they regulate, continues to be unraveled. New hereditary kidney cancer syndromes, like familial oncocytoma and the Birt-Hogg-Dubé syndrome, have been identified and the search for the genes that cause them is under way. Researching the genetics of these disorders is essential for an understanding of sporadic kidney cancer genetics. This chapter will review the current knowledge of the hereditary kidney cancer syndromes, the genes that cause them, new advances in genetic research and techniques, and how this information impacts upon diagnostic, prognostic, and therapeutic methods of the future.

Molecular cytogenetic characterization of early and late renal cell carcinomas in von Hippel-Lindau disease

Deletions of 3p25, gains of chromosomes 7 and 10, and isochromosome 17q are known cytogenetic aberrations in sporadic renal cell carcinoma (RCC). In addition, a majority of RCCs have loss of heterozygosity (LOH) of the Von Hippel-Lindau (VHL) gene located at chromosome band 3p25. Patients who inherit a germline mutation of the VHL gene can develop multifocal RCCs and other solid tumors, including malignancies of the pancreas, adrenal medulla, and brain. VHL tumors follow the two-hit model of tumorigenesis, as LOH of VHL, a classic tumor suppressor gene, is the critical event in the development of the neoplastic phenotype. In an attempt to define the cytogenetic aberrations from early tumors to late RCC further, we applied spectral karyotyping (SKY) to 23 renal tumors harvested from 6 unrelated VHL patients undergoing surgery. Cysts and low-grade solid lesions were near-diploid and contained 1-2 reciprocal translocations, dicentric chromosomes, and/or isochromosomes. A variety of sole numerical aberrations included gains of chromosomes 1, 2, 4, 7, 10, 13, 21, and the X chromosome, although no tumors had sole numerical losses. Three patients shared a breakpoint at 2p21-22, and three others shared a dicentric chromosome 9 or an isochromosome 9q. In contrast to the near-diploidy of the low-grade lesions, a high-grade lesion and its nodal metastasis were markedly aneuploid, revealed loss of VHL by fluorescence in situ hybridization (FISH), and contained recurrent unbalanced translocations and losses of chromosome arms 2q, 3p, 4q, 9p, 14q, and 19p as demonstrated by comparative genomic hybridization (CGH). By combining SKY, CGH, and FISH of multiple tumors from the same VHL kidney, we have begun to identify chromosomal aberrations in the earliest stages of VHL-related renal cell tumors. Our current findings illustrate the cytogenetic heterogeneity of different VHL lesions from the same kidney, which supports the multiclonal origins of hereditary RCCs. Published 2001 Wiley-Liss, Inc.

Predictive value of preoperative tests in discriminating bilateral adrenal hyperplasia from an aldosterone-producing adrenal adenoma

In primary hyperaldosteronism, discriminating bilateral adrenal hyperplasia (BAH) from an aldosterone-producing adenoma (APA) is important because adrenalectomy, which is usually curative in APA, is seldom effective in BAH. We analyzed the results from our most recent 7-yr series to evaluate the predictive value of preoperative noninvasive tests compared with adrenal vein sampling (AVS). Forty-eight patients with hypertensive hyperaldosteronism underwent bedside testing, computed tomography (CT) imaging, and AVS. Those in whom the results of AVS indicated APA underwent adrenalectomy. Twelve (30%) and 14 (34%) of 41 patients with APA had paradoxical falls with ambulation in plasma aldosterone concentration (PAC) and 18-hydroxycorticosterone (18-OH-B), respectively. Twenty-nine (70%) and 26 (65%) APA patients had a rise in PAC and 18-OH-B, respectively, as did all 8 BAH patients. Significant identifiers of BAH were supine PAC values less than 15 ng/dL (P: = 0.04), an increase greater than 60% (P: = 0.02) in PAC with ambulation, and supine 18-OH-B values less than 60 ng/dL (P: = 0.04). CT imaging alone was not predictive for BAH or APA. In our population, patients with a positive bedside test result (e.g. a fall in PAC and/or 18-OH-B) and a unilateral adrenal nodule on CT (10 of 41 patients) could have proceeded directly to adrenalectomy for APA. However, a positive bedside test result with a negative CT or a negative bedside test result regardless of CT findings required AVS to confirm the diagnosis and site of disease.

Exposure of nerve growth factor-treated PC12 rat pheochromocytoma cells to a modulated radiofrequency field at 836.55 MHz: effects on c-jun and c-fos expression

Rat PC12 pheochromocytoma cells have been treated with nerve growth factor and then exposed to athermal levels of a packet-modulated radiofrequency field at 836.55 MHz. This signal was produced by a prototype time-domain multiple-access (TDMA) transmitter that conforms to the North American digital cellular telephone standard. Three slot average power densities were used: 0.09, 0.9, and 9 mW/cm2. Exposures were for 20, 40, and 60 min and included an intermittent exposure regimen (20 min on/20 min off), resulting in total incubation times of 20, 60, and 100 min, respectively. Concurrent controls were sham exposed. After extracting total cellular RNA, Northern blot analysis was used to assess the expression of the immediate early genes, c-fos and c-jun, in all cell populations. No change in c-fos transcript levels were detected after 20 min exposure at each field intensity (20 min was the only time period at which c-fos message could be detected consistently). Transcript levels for c-jun were altered only after 20 min exposure to 9 mW/cm2 (average 38% decrease).

The National Cancer Data Base Report on poor survival of U.S. gastric carcinoma patients treated with gastrectomy: Fifth Edition American Joint Committee on Cancer staging, proximal disease, and the "different disease" hypothesis

BACKGROUND

A high proportion of U.S. patients with gastric carcinoma do not receive surgical treatment. To sharpen staging criteria and facilitate comparisons with surgical series, an analysis of patients whose treatment included gastrectomy was undertaken. In addition, to evaluate the "different disease" hypothesis as an explanation for superior Japanese results, outcomes for Japanese Americans were examined.

METHODS

Data were obtained from National Cancer Data Base (NCDB) reports of 50,169 gastric carcinoma cases diagnosed during the years 1985-1996 and treated with gastrectomy. In addition to demographic and treatment information, 5-year and 10-year relative survival rates are presented, with stage defined according to fifth edition American Joint Committee on Cancer (AJCC) staging procedures.

RESULTS

Stage-stratified 5-year and 10-year relative survival rates were as follows: Stage IA, 78%/65%; Stage IB, 58%/42%; Stage II, 34%/26%; Stage IIIA, 20%/14%; Stage IIIB, 8%/3%; and Stage IV, 7%/5%. Stage-stratified survival for Japanese Americans was higher. Males had a poorer prognosis than females, and the male-to-female ratio for Japanese Americans was lower. Proximal tumors were associated with a worse prognosis than distal tumors; the proportion of Japanese Americans with proximal disease was less than in the overall patient group. Japanese Americans underwent resection of adjacent organs less frequently. In this series, adjuvant therapy did not substantially affect survival. Overall, 20% were 10-year survivors; of these, 67% were lymph node negative and 98% had </= 8 involved lymph nodes. Five-year stage-stratified survival increased for cases with >/= 15 lymph nodes analyzed. Stage migration was evident in cases with </= 15 nodes examined.

CONCLUSIONS

The current AJCC/International Union Against Cancer TNM staging system fails to accommodate the effect of proximal location on prognosis. Largely because Japanese Americans present with fewer proximal tumors, have a lower male-to-female ratio, and undergo adjacent organ resection less frequently, stage- stratified survival for Japanese Americans appears to be superior. In the U.S., surgical undertreatment of patients with this disease appears to be a problem.

The National Cancer Data Base Report on poor survival of U.S. gastric carcinoma patients treated with gastrectomy: Fifth Edition American Joint Committee on Cancer staging, proximal disease, and the "different disease" hypothesis

BACKGROUND

A high proportion of U.S. patients with gastric carcinoma do not receive surgical treatment. To sharpen staging criteria and facilitate comparisons with surgical series, an analysis of patients whose treatment included gastrectomy was undertaken. In addition, to evaluate the "different disease" hypothesis as an explanation for superior Japanese results, outcomes for Japanese Americans were examined.

METHODS

Data were obtained from National Cancer Data Base (NCDB) reports of 50,169 gastric carcinoma cases diagnosed during the years 1985-1996 and treated with gastrectomy. In addition to demographic and treatment information, 5-year and 10-year relative survival rates are presented, with stage defined according to fifth edition American Joint Committee on Cancer (AJCC) staging procedures.

RESULTS

Stage-stratified 5-year and 10-year relative survival rates were as follows: Stage IA, 78%/65%; Stage IB, 58%/42%; Stage II, 34%/26%; Stage IIIA, 20%/14%; Stage IIIB, 8%/3%; and Stage IV, 7%/5%. Stage-stratified survival for Japanese Americans was higher. Males had a poorer prognosis than females, and the male-to-female ratio for Japanese Americans was lower. Proximal tumors were associated with a worse prognosis than distal tumors; the proportion of Japanese Americans with proximal disease was less than in the overall patient group. Japanese Americans underwent resection of adjacent organs less frequently. In this series, adjuvant therapy did not substantially affect survival. Overall, 20% were 10-year survivors; of these, 67% were lymph node negative and 98% had </= 8 involved lymph nodes. Five-year stage-stratified survival increased for cases with >/= 15 lymph nodes analyzed. Stage migration was evident in cases with </= 15 nodes examined.

CONCLUSIONS

The current AJCC/International Union Against Cancer TNM staging system fails to accommodate the effect of proximal location on prognosis. Largely because Japanese Americans present with fewer proximal tumors, have a lower male-to-female ratio, and undergo adjacent organ resection less frequently, stage- stratified survival for Japanese Americans appears to be superior. In the U.S., surgical undertreatment of patients with this disease appears to be a problem.

Ten-year survey of lung cancer treatment and survival in hospitals in the United States: a national cancer data base report

BACKGROUND

Primary lung cancer accounts for approximately 14% of all new cancers and 28% of cancer deaths in the U.S. Previous reviews have shown limited progress in the management or outcome of this devastating disease.

METHODS

Reports described in the current study were 713,043 primary lung malignancies diagnosed between 1985 and 1995 and submitted to the National Cancer Data Base. Demographic, tumor, and treatment patterns for 1995 were compared with those for 1985-1987, 1988-1991, and 1992-1994. Ten-year relative survival rates were presented for selected demographic and histologic groups and 5-year relative survival rates were presented by stage and dominant treatment modalities for major carcinoma histologies.

RESULTS

Previously observed demographic trends were evident, with increasing proportions of patients being older, female, and African American, and more cases reported to be adenocarcinomas. There was a substantial shift toward more complete staging but no change in the distribution of staged cases. Compared with earlier patients, fewer 1995 patients received cancer-directed treatment. More surgical patients underwent lymph node dissection, and radiation treatment was supplemented more often with chemotherapy. The overall 10-year relative survival rate was 7%. The 5-year survival for American Joint Committee on Cancer Stage I surgical patients was >50% for all nonsmall cell histologic groups.

CONCLUSIONS

Recent shifts in treatment, although minimal, are consistent with current literature concerning the effectiveness of lung carcinoma treatment. The authors believe that the overall poor survival of lung carcinoma patients points to a continuing need for improved prevention and treatment measures. The comparatively superior survival of Stage I nonsmall cell lung carcinoma surgical patients indicates that a substantial number of patients have the potential to be treated successfully.

Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats chronically exposed to 836 MHz modulated microwaves

We have tested an 836.55 MHz field with North American Digital Cellular (NADC) modulation in a 2-year animal bioassay that included fetal exposure. In offspring of pregnant Fischer 344 rats, we tested both spontaneous tumorigenicity and the incidence of induced central nervous system (CNS) tumors after a single dose of the carcinogen ethylnitrosourea (ENU) in utero, followed by intermittent digital-phone field exposure for 24 months. Far-field exposures began on gestational day 19 and continued until weaning at age 21 days. Near-field exposures began at 35 days and continued for the next 22 months, 4 consecutive days weekly, 2 h/day. SAR levels simulated localized peak brain exposures of a cell phone user. Of the 236 original rats, 182 (77%) survived to the termination of the whole experiment and were sacrificed at age 709-712 days. The 54 rats (23%) that died during the study ("preterm rats") formed a separate group for some statistical analyses. There was no evidence of tumorigenic effects in the CNS from exposure to the TDMA field. However, some evidence of tumor-inhibiting effects of TDMA exposure was apparent. Overall, the TDMA field-exposed animals exhibited trends toward a reduced incidence of spontaneous CNS tumors (P < 0. 16, two-tailed) and ENU-induced CNS tumors (P < 0.16, two-tailed). In preterm rats, where primary neural tumors were determined to be the cause of death, fields decreased the incidence of ENU-induced tumors (P < 0.03, two-tailed). We discuss a possible approach to evaluating with greater certainty the possible inhibitory effects of TDMA-field exposure on tumorigenesis in the CNS.

A survey of hospital management practices for vulvar melanoma

BACKGROUND

Vulvar melanoma is a very rare form of cancer. The purpose of this study was to describe practice patterns for the management of vulvar melanoma.

STUDY DESIGN

The National Cancer Data Base was reviewed from 1985 through 1994 for patient reports submitted with a diagnosis of vulvar melanoma.

RESULTS

Five hundred sixty-nine patients with vulvar melanoma were identified. A substantial number of patients were older; during the latter period of this study (1990 to 1994), 50% were 70 years old or older. Surgery was used in more than 90% of patients with stages 0 to III. Local excision was used mainly in early-stage (0 and I) disease. Adjuvant therapy was used infrequently. Lymph node evaluation was performed in more than half of the patients, with greater frequency for patients who had advanced disease. The overall 5-year relative survival rate was 62%. If the lymph nodes contained metastases, survival was poor. Patients with recurrent disease also had poor survival.

CONCLUSIONS

Surgery remains the mainstay of therapy for vulvar melanoma. The use of excision and radical operations remained constant during the 10 years of the study.

The effect of nutritional and hormonal supplementation on protein synthesis immediately after liver transplantation

We have previously shown that immediately after liver transplantation (LT) the porcine recipient exhibits elevated plasma glucagon, increased fractional synthetic rate (FSR) of fibrinogen, and decreased FSR of fixed or structural liver proteins. The purpose of this study was to evaluate the effect of nutritional and hormonal supplementation on these observations 24 h after LT. Two groups of nine pigs were studied 1 day after LT using radioisotopic and arteriovenous difference techniques. A control group underwent LT with saline infusion and a supplemented group underwent LT with infusion of glucose, amino acids (6 and 1.06 mg/kg. min, respectively), and intraportal insulin (0.6 mU/kg. min) and glucagon (1.3 ng/kg. min). Primed constant infusions of [3H]leucine were used to determine leucine flux, an estimate of whole body protein breakdown, and fractional synthetic rates (FSR). The following changes were noted with supplementation: elevated plasma insulin (6 +/- 1 versus 29 +/- 4 microU/ml, control versus supplemented, respectively, P < 0.05), decreased glucagon to normal levels (323 +/- 65 versus 102 +/- 12 pg/ml, P < 0.05), decreased fibrinogen FSR (108 +/- 15 versus 70 +/- 6%/day, P < 0.025), and increased fixed liver protein FSR (8 +/- 1 versus 13 +/- 2%/day, P < 0.05, respectively). Albumin FSR was unaltered by supplementation (8 +/- 2 versus 6 +/- 1%/day, respectively). Nutritional and hormonal supplementation immediately after LT restored the measured protein synthesis in the allograft to near normal levels 1 day after transplantation.

The National Cancer Data Base report on endometrial carcinoma in African-American women

BACKGROUND

Although the incidence of uterine carcinoma is lower among African-American women compared with white women, the mortality rates are higher for African-American patients. This report is part of an ongoing series on gynecologic malignancies in African-American women.

METHODS

Hospital registry reports collected by the National Cancer Data Base were used to describe some of the differences in case presentation and management characteristics of endometrial carcinoma in these two groups. The cases represented 52,307 Non-Hispanic white and 3226 African-American women diagnosed with primary carcinoma of the endometrium between 1988-1994.

RESULTS

More African-American patients were diagnosed with less favorable histologies than white patients, at more advanced stages of disease, and with less tumor differentiation. Income had no effect on stage or grade. African-American patients were treated less often for their tumor at every stage of diagnosis compared with white women. Income generally had no effect on whether treatment was provided, but limited income was associated with a lack of treatment in African-American patients with American Joint Committee on Cancer Stage IV tumors. African-American women were less frequently treated surgically and, among surgically treated patients at advanced stages of disease, they received adjuvant radiotherapy less often and chemotherapy more often than white patients. Five-year survival was poorer for African-American women, even for patients with the more favorable Stage I adenocarcinoma who were treated surgically.

CONCLUSIONS

All patients, regardless of race, should be treated appropriately as dictated by medical and prognostic factors and not by race. Although no screening methods currently exist for endometrial carcinoma, the development of procedures for identifying patients at risk for the prognostic factors that lead to a poor outcome should be a primary focus.

Effect of 60 Hz magnetic field exposure on c-fos expression in stimulated PC12 cells

Rat pheochromocytoma PC12 cells have been treated with nerve growth factor (NGF) at final concentrations of 2, 4, 8, and 16 ng/ml, and then were exposed to 60-Hz, sinusoidal magnetic fields (MF) of 12.5, 25, 50, and 100 microT (rms) for 30 min. Transcript levels for both c-fos and glyceraldehyde-3 -phosphate dehydrogenase were determined by Northern blot analysis using 32P-labeled cDNA probes. No change in c-fos expression was measured at any condition employed. Treatment of PC12 cells with a combination of agents (NGF, forskolin, and tetradecanoylphorbol acetate [TPA]) increased c-fos expression over that detected with NGF alone. MF exposure of cells treated with the three-agent regimen produced two outcomes, either no change or a doubling of c-fos expression. In subsequent experiments, cells were treated with NGF, NGF + forskolin + TPA, or pre-treated with anisomycin and then treated with NGF + forskolin + TPA. It was determined that MF exposure, like superinduction with anisomycin, increased c-fos expression only in cultures which were not yet exhibiting maximal c-fos expression. It is hypothesized that MF exposure, like anisomycin, may alter the activity of key intracellular protein kinases.

Biologic effects of low-level electromagnetic fields: current issues and controversies

There is uncertainty and controversy about the extent to which low level electromagnetic fields may cause deleterious effects, but even experts who are skeptical about many supposed hazards are willing to agree that electromagnetic fields even weaker than those in the MR environment can have effects under certain conditions. In order that readers can familiarize themselves enough with the subject to make an informed independent assessment, discuss it knowledgeably in public, and have the means with which to evaluate new developments and avoid experimental pitfalls if planning their own research in the area, they are provided with some of the most recent finding of in vitro and in vivo research from outside the MR literature as well as some of the results and controversies coming from recent epidemiological studies.

The National Cancer Data Base report on cancer of the vagina

BACKGROUND

This study was conducted to determine practice patterns in the management of vaginal malignancy.

METHODS

The National Cancer Data Base (NCDB), a large central registry of hospital case data, was reviewed for the 10-year period 1985-1994 for patients registered with a primary diagnosis of vaginal cancer. Patients with a prior history of malignancy were excluded.

RESULTS

Between 1985-1994 4885 cases of vaginal cancer were submitted to NCDB. More than 90% were epithelial neoplasia with approximately 25% of these in situ lesions only. Squamous carcinoma was more common as the age of the patient progressed. Adenocarcinomas represented nearly all the carcinomas in the group of patients age < 20 years and were observed less frequently with advanced age. Relative survival at 5 years was stage-related: Stage 0: 96%; Stage I: 73%; Stage II: 58%; and Stages III-IV: 36%. Melanoma had an extremely poor prognosis with a 5-year survival rate of only 14%. A significant number of sarcomas occurred in children for whom chemotherapy played a major role in treatment. Chemotherapy was used less frequently in the older patients. Survival was better in the younger patients (90% vs. 30% in the older patients).

CONCLUSIONS

Although vaginal cancer is the rarest of genital malignancies, it appears that treatment and results from the NCDB reported from multiple institutions followed prescribed treatment guidelines.

The National Cancer Data Base report on the relationship of race and national origin to the histology of nasopharyngeal carcinoma

BACKGROUND

The development of nasopharyngeal carcinoma reflects interactions of genetics, diet, and viral agents. It is more common in Asians than non-Asians, with different characteristic histologic types. This study examined nasopharyngeal carcinoma in the U.S. as a function of patient origin and histology.

METHODS

The data were from the National Cancer Data Base (NCDB). The 5069 nasopharyngeal carcinoma cases were grouped by histologic type: keratinizing squamous cell, nonkeratinizing, and undifferentiated carcinoma. Patient origin was derived from race, Hispanic ethnicity, and place of birth.

RESULTS

World Health Organization (WHO) type 1 keratinizing squamous cell carcinomas comprised 75% of the U.S. nasopharyngeal carcinoma cases and were found most often in U.S.-born, non-Hispanic whites. WHO-2 nonkeratinizing and WHO-3 undifferentiated carcinomas of the nasopharnyx comprised the remaining 25% of nasopharyngeal carcinomas and were more common in Asians. Histologic composition varied for each of the 12 patient origin groups in the study and correlated with survival after treatment with ionizing radiation. Asians had the highest proportion of radioresponsive WHO-2 nonkeratinizing and WHO-3 undifferentiated carcinomas of the nasopharynx and better survival than African-Americans and Hispanic and non-Hispanic whites, who had the greatest number of the less radioresponsive keratinizing squamous cell carcinomas of the nasopharynx. The 5-year relative survival was 65% for the nonkeratinizing and undifferentiated carcinomas of the nasopharynx and 37% for the keratinizing variety.

CONCLUSIONS

The survival rate of the patient origin groups correlated with the histologic composition of their nasopharyngeal carcinomas. Those with the highest proportion of radioresponsive nonkeratinizing and undifferentiated carcinomas had the best survival.

Mitochondrial membrane potential and nuclear changes in apoptosis caused by serum and nerve growth factor withdrawal: time course and modification by (-)-deprenyl

Studies in non-neural cells have suggested that a fall in mitochondrial membrane potential (DeltaPsiM) is one of the earliest events in apoptosis. It is not known whether neural apoptosis caused by nerve growth factor (NGF) and serum withdrawal involves a decrease in DeltaPsiM. We used epifluorescence and laser confocal microscopy with the mitochondrial potentiometric dyes chloromethyl-tetramethylrosamine methyl ester and 5,5',6, 6'-tetrachloro-1,1',3,3'-tetraethybenzimidazol carbocyanine iodide to estimate DeltaPsiM. PC12 cells were differentiated in media containing serum and NGF for 6 d before withdrawal of trophic support. After washing, the cells were incubated with media containing serum and NGF (M/S+N), media without serum and NGF, or media with the "trophic-like" monoamine oxidase B inhibitor, (-)-deprenyl. Mitochondria in cells without trophic support underwent a progressive shift to lower DeltaPsiM values that was significant by 3 hr after washing. The percentages of cells with nuclear chromatin condensation or nuclear DNA fragmentation were not significantly increased above those for cells in M/S+N until 6 hr after washing. Replacement of cells into M/S+N or treatment with (-)-deprenyl markedly reduced the proportion of mitochondria with decreased DeltaPsiM. Measurements of cytoplasmic peroxyl radical levels with 2',7'-dihydrodichlorofluorescein fluorescence and intramitochondrial Ca2+ with dihydro-rhodamine-2-acetylmethyl ester indicated that cytoplasmic peroxyl radical levels were not increased until after 6 hr, whereas increases in intramitochondrial Ca2+ paralleled the decreases in DeltaPsiM. (-)-Deprenyl appeared to alter the relationship between intramitochondrial Ca2+ levels and DeltaPsiM, possibly through its reported capacity to increase the synthesis of proteins such as BCL-2.

Developmental localization of retina cognin synthesis by in situ hybridization

Retina cognin (R-cognin) is a 50 kDa protein involved in cell recognition and neuronal differentiation during development of the embryonic chick retina. Initial characterization of a partial cDNA encoding R-cognin revealed a striking similarity to the cDNA encoding protein disulfide isomerase (PDI), a 57 kDa multifunctional protein. The exact nature of the relationship between R-cognin and PDI is not known; however, both proteins appear to be encoded by the same gene. In the present study, we developed cRNA probes to examine the expression of R-cognin and PDI transcripts in embryonic chick retina and liver. In the retina, the amount of transcript decreased with embryonic age, in parallel to a similar decrease in R-cognin protein. In the liver, where PDI is prominently expressed, the amount of transcript was not developmentally regulated. The spatial and temporal pattern of expression of the R-cognin-encoding retinal transcript was examined by in situ hybridization. R-cognin mRNA was expressed in cells across the retina early in retinogenesis, but became restricted to the cells of the inner retina later in development. This pattern of expression was the same as the developmental pattern of R-cognin protein [Dobi et al., Invest. Ophthalmol. Vis. Sci. 27, (1986) p. 323-329], thus, demonstrating that this secreted protein functions at the surface of the cells where it is transcribed.

The National Cancer Data Base report on recent hospital cancer program progress toward complete American Joint Committee on Cancer/TNM staging

BACKGROUND

American Joint Committee on Cancer (AJCC) staging procedures were first published in 1977. Since 1991 the Commission on Cancer (COC) has required AJCC staging of all nonpediatric cancers. The National Cancer Data Base (NCDB) encouraged recording of AJCC staging through analyses of selected aspects of staging completeness. We reviewed the trend toward the adoption of routine AJCC staging by hospitals for the 5-year period 1990-1994.

METHODS

NCDB reports for nearly 2 million stageable cancers diagnosed from 1990 through 1994 were examined with emphasis on the hospital cancer program environment. Staging was complete if the hospital submitted stage codes for > or =90% of stageable cases or absent if stage codes were submitted for <5%. Hospitals were classified by ownership and type of cancer program. Regional staging practices also were reviewed.

RESULTS

Overall staging increased from 78% to 88%, with increases for every site except carcinomas of the skin, cancers of the extrahepatic bile ducts and urethra, melanoma of the eyelid, and retinoblastoma The percent of hospitals staging completely increased from 49% to 61%, and the percent not routinely staging decreased from 6% to 3%. Complete staging increased in all hospital categories except For-Profit. The trend toward complete staging was uneven among states and regions.

CONCLUSIONS

Hospital staging policies were affected by activities of the AJCC, COC, NCDB, clinical protocol procedures, and state policies. The varied completeness of staging at the hospital level by state, region, and type of hospital indicates that the adoption of routine staging is ongoing.