The overexpression of RHAMM, a hyaluronan-binding protein that regulates ras signaling, correlates with overexpression of mitogen-activated protein kinase and is a significant parameter in breast cancer progression.

RHAMM is an oncogene that regulates signaling through ras and controls mitogen-activated protein kinase [extracellular signal-regulated protein kinase (ERK)] expression in embryonic murine fibroblasts. ERK is a dual-specificity kinase that controls expression of proteins relevant to tumorigenesis, proliferation, and motility. To assess whether RHAMM and ERK are involved in human breast tumor progression, we examined RHAMM, ras, and ERK expression in two cohorts of breast cancer patients using reverse transcription-PCR and immunocytochemistry. We show that overexpression of RHAMM in primary tumors of two patient cohorts was significantly prognostic of poor outcome in breast cancer progression. Furthermore, RHAMM overexpression occurred within subsets of tumor cells in the primary tumor, and this staining pattern was associated with lymph node metastases. The metastases exhibited a significantly higher level of staining for RHAMM than did the primary tumor. RHAMM expression strongly correlated with overexpression of both ras and ERK, although overexpression of either of these two signaling molecules was not by itself a prognostic indicator. These results identify a new parameter that is involved in lymph node metastasis of primary breast cancers and suggest that quantification of RHAMM overexpression may be a useful prognostic indicator for breast carcinoma progression.

Pulmonary aspergillosis in acquired immune deficiency syndrome: autopsy study of an emerging pulmonary complication of human immunodeficiency virus infection.

Pulmonary aspergillosis has recently been described as an emerging infection in patients with acquired immune deficiency syndrome (AIDS), but the pathological changes have not been well documented. In this autopsy study, 17 cases of AIDS-related pulmonary aspergillosis were identified from the files of two institutions. With the exception of hypersensitivity reactions, the entire spectrum of pulmonary aspergillosis was represented. Thirteen patients exhibited acute invasive aspergillosis, and seven patients had evidence of subacute or chronic invasive infection, four of whom also had areas of acute invasion. One patient had necrotizing bronchial aspergillosis as well as acute invasive infection, and one individual had saprophytic colonization of a cavity caused by previous Pneumocystis carinii pneumonia (PCP) without evidence of invasive aspergillosis. The same conditions known to predispose immunocompromised individuals without human immunodeficiency virus (HIV) infection to invasive pulmonary aspergillosis were also identified in these patients with AIDS and included neutropenia, steroid therapy, and underlying lung disease. Additional pulmonary conditions were identified in all but one case and consisted mainly of infection or some form of chronic lung disease. In particular, half of the cases were associated with pulmonary fibrosis related to prior PCP. All cases occurred in or after 1990, confirming the perception of the recent emergence of aspergillosis in AIDS. As suggested by this study, one reason for this may be that patients with AIDS are now living long enough to develop one or more of the predisposing conditions for pulmonary aspergillosis.

Quantitative differences in the production and toxicity of CF2=BrCl versus CH2F-O-C(=CF2)(CF3) (compound A): the safety of halothane does not indicate the safety of sevoflurane.

UNLABELLED: Carbon dioxide absorbents degrade both halothane and sevoflurane to toxic unsaturated compounds (CF2=CBrCl and CH2F-O-C[=CF2][CF3] [i.e., Compound A], respectively). Given the long history of safe administration of halothane, comparable toxicities of these degradation products would imply a similar safety of sevoflurane. We therefore examined CF2=CBrCl in the context of four issues relevant to previous studies of the toxicity of Compound A: 1) reactivity of the degradation product in vitro; 2) rate of its production in vitro; 3) its in vivo toxicity; 4) importance of the beta-lyase pathway to the toxicity in vivo. We found the following. 1) CF2=CBrCl is less reactive than Compound A, degrading in human serum albumin at one-fifth the rate of Compound A. 2) Over a 3-h period of "anesthesia," a standard circle system containing Baralyme (Allied Healthcare Products, Inc., St. Louis, MO) produces 30 times as much Compound A from a minimum alveolar anesthetic concentration (MAC) concentration of sevoflurane as CF2=CBrCl from a MAC concentration of halothane; with soda lime, the difference is 60-fold. Correcting for differences in uptake of halothane versus sevoflurane decreases the differences to 20-40 times. 3) For a 3-h administration to rats, the partial pressure of Compound A causing minimal renal injury or necrosis of half the affected tubule cells exceeds the partial pressure of CF2=CBrCl causing minimal injury or necrosis of half the affected tubule cells by a factor of approximately 4-6. Thus, the ratio of production (Item 2 above) to the partial pressure causing injury with CF2=CBrCl is approximately a quarter of that ratio for Compound A. 4) Compounds that block the beta-lyase pathway either do not change (acivicin) or decrease (aminooxyacetic acid; AOAA) renal injury from CF2=CBrCl in rats, whereas these compounds increase (acivicin) or do not change (AOAA) injury from Compound A. We conclude that the safety of halothane cannot be used to support the safety of sevoflurane. IMPLICATIONS: Carbon dioxide absorbents degrade halothane and sevoflurane to unsaturated compounds nephrotoxic to rats. Relative to sevoflurane's degradation product, halothane's degradation product has less toxicity relative to production, less reactivity, and a different mechanism of injury. The clinical absence of halothane nephrotoxicity does not necessarily indicate a similar absence for sevoflurane.

Frequent homozygous deletion of cyclin-dependent kinase inhibitor 2 (MTS1, p16) in superficial bladder cancer detected by fluorescence in situ hybridization.

Deletion of all or part of chromosome 9 is a well-described genetic alteration in bladder tumors. It has been proposed that inactivation of a tumor-suppressor gene on chromosome 9 is an important event in tumor development. Recent reports have supported cyclin-dependent kinase inhibitor 2 (CDKN2, also known as MTS1, INK4, p16) at 9p21 as a candidate tumor-suppressor gene in solid tumors. However, the prevalence of CDKN2 mutations in primary bladder tumors has been controversial. Therefore, we applied gene-specific probes for CDKN2 and the interferon alpha gene (IFNA), also located at 9p21, to characterize further the genomic deletions at this locus in bladder cancer. Seventeen superficial (pTa or pT1) bladder tumor specimens were examined for gene deletion by fluorescence in situ hybridization. Dual-labeling hybridization with a repetitive pericentromeric probe for chromosome 9 and a gene-specific probe for CDKN2 was performed to characterize the gene copy number in relation to the chromosome 9 copy number on a cell-by-cell basis. Homozygous deletion for CDKN2 without homozygous IFNA deletion was found in 5 of 17 tumors tested. Both genes were deleted in one additional case, and one tumor showed deletion of IFNA without deletion of CDKN2. Homozygous deletion at the 9p21 locus was found only in tumors having monosomy for the chromosome 9 centromeric signal. These results indicate that the homozygous deletion of the CDKN2 gene is a frequent and early event in superficial bladder cancer.

Cutaneous squamous cell carcinoma in human immunodeficiency virus-infected patients. A study of epidemiologic risk factors, human papillomavirus, and p53 expression.

OBJECTIVE: To examine risk factors for the development of cutaneous squamous cell carcinoma (SCC) in a group of human immunodeficiency virus (HIV)-infected patients, including evaluation and detection of epidemiologic risk factors of human papillomavirus (HPV) and p53 expression. DESIGN: Case-control study during a 3-year period. SETTING: Dermatologic referral center. PATIENTS: Thirty-three HIV-infected patients who had 97 SCCs were compared with 24 HIV-infected patients who had 70 basal cell carcinomas (BCCs). MAIN OUTCOME MEASURES: Age, skin type, amount of sun exposure, actinic damage, family history of skin cancer and history of smoking and warts. Specimens of SCC and BCC were examined for HPV using polymerase chain reaction. Presence of p53 was examined using immunohistochemical analysis. Specimens from tumor-free, non-sun-exposed areas from these same patients were used as controls. RESULTS: Risk factors for the development of both types of carcinoma included fair skin type and excessive sun exposure (> 6 h/d during the previous 10 years). The HIV-infected patients with SCCs tended to have outdoor occupations. The location of SCCs favored the head and neck; BCCs were located on the trunk. Patients with SCCs had later-stage HIV disease than did patients with BCCs. Half of the patients with SCC had a history of genital or nongenital warts. Seventy-one percent (17/24) had a smoking history. No statistical difference existed between patients with SCCs and BCCs for history of smoking or warts. Human papillomavirus was not found in most of our SCC, BCC, or control specimens. However, 92% (22/24) of the SCC specimens and 90% (18/20) of the BCC specimens stained for p53. Control specimens from non-sun-exposed skin of HIV-infected patients did not stain for p53. Epidermal staining was present in 95% (17/20) of tissue adjacent to SCCs and 47% (7/15) of tissue adjacent to BCCs. A significantly positive correlation existed between the amount of sun exposure and the amount of p53 staining seen in adjacent epidermal tissue (r = 0.07; P = .01). CONCLUSIONS: Risk factors for the development of SCCs and BCCs in HIV-infected patients are similar: fair skin type and excessive sun exposure. Our study does not support that HPV is an oncogenic factor in the development of these cutaneous tumors but provides evidence that p53 overexpression may play a role.

Acetaminophen predisposes to renal and hepatic injury from compound A in the fasting rat.

Results of previous studies of Compound A, a degradation product of sevoflurane, suggested that decreases in glutathione stores may increase potential Compound A nephrotoxicity. By depleting these stores, fasting and various drugs may augment such nephrotoxicity. To test this possibility, we pretreated fasted Fisher rats with intraperitoneal 0 (vehicle only), 250, 500, or 1000 mg/kg of acetaminophen, a commonly used drug that depletes glutathione stores. After pretreatment, we administered Compound A for 3 h at concentrations ranging from 0 to 200 ppm. The larger doses of acetaminophen predisposed to greater renal and hepatic injury. For example, at 100 ppm Compound A, no rats had renal cortical injury when given vehicle only or 250 mg/kg acetaminophen, but 90% (9 of 10 rats) had injury at 500 mg/kg and 100% (13 of 13) at 1000 mg/kg. Similarly, at 100 ppm Compound A, hepatic injury was not evident with vehicle only or 250 mg/kg, but occurred in 30% of rats at 500 mg/kg, and in 69% at 1000 mg/kg. Given the considerable differences between humans and rats, and given the large doses of acetaminophen required, the clinical relevance of these findings is unclear. If clinically relevant, circumstances producing glutathione depletion (e.g., ingestion of drugs such as acetaminophen, or nutritional deficiencies) may predispose to renal or hepatic injury from Compound A in patients given sevoflurane at low fresh gas flow rates.

Lack of p53 protein immunoreactivity in bilateral diffuse uveal melanocytic proliferation.

BACKGROUND: Bilateral diffuse uveal melanocytic proliferation is a poorly understood disorder characterized by the progressive proliferation of uveal melanocytes associated with a systemic nonocular malignancy. Overexpression of p53 protein plays a role in the loss of regulatory control of normal cell proliferation, and p53 is the most commonly identified oncogenic protein in human malignancies. We tested the hypothesis that the aberrant cellular activity in bilateral diffuse uveal melanocytic proliferation involves the overexpression of p53 protein. METHODS: Eight eyes from four patients with bilateral diffuse uveal melanocytic proliferation were tested for p53 protein using an immunoperoxidase technique with an anti-p53 protein monoclonal antibody sensitive for normal and mutant p53 protein. RESULTS: The p53 protein could not be detected in any of the eight eyes. CONCLUSIONS: The proliferation of uveal melanocytes in bilateral diffuse uveal melanocytic proliferation does not depend on the overexpression of p53 protein. The loss of cellular regulatory control in bilateral diffuse uveal melanocytic proliferation is probably mediated through another mechanism.

Studies of the mechanism of nephrotoxicity of compound A in rats.

CO2 absorbents acting on sevoflurane produce compound A [CF2=C(CF3)OCH2F]. Rats breathing 25-50 ppm of compound A for 3-12 h demonstrate corticomedullary renal injury. Several halogenated alkenes also produce a well described corticomedullary lesion by conversion of glutathione conjugates of these alkenes to cysteine s-conjugates and subsequent metabolism by renal cysteine conjugate ß-lyase to nephrotoxic halothionoacetyl halides. We tested whether a similar mechanism explained the nephrotoxicity of compound A or whether an oxidative metabolism of compound A by cytochrome P-450 was required for the induction of nephrotoxicity. A closed rebreathing system was used and male Wistar rats were exposed for 1 h to: (1) oxygen alone; (2) 800 ppm compound A; (3) 800 ppm compound A after pretreatment with intraperitoneal aminooxyacetic acid (AOAA), 0.5 mmoles/kg, an inhibitor of renal cysteine conjugate ß-lyase; (4) 600 ppm compound A; (5) 600 ppm compound A after pretreatment with intraperitoneal AOAA, 0.50 mmoles/kg plus acivicin (AT-125), 0.25 mmoles/kg, an inhibitor of gamma glutamyl transpeptidase; (6) 600 ppm compound A after pretreatment with 1600 mg/kg piperonyl butoxide (PB) subcutaneously, and (7) 600 ppm compound A after pretreatment with 100 mg/kg 1-aminobenzotriazole (ABT) by intraperitoneal injection (both PB and ABT inhibit cytochrome P-450s). All rats were killed 24 h following exposure to compound A or oxygen, or to pretreatments without compound A, and the kidneys were collected for histological analysis. Pretreatments given without compound A did not cause renal injury. Necrosis was found in 20.9±16.7% (mean±SD) of corticomedullary tubule cells following exposure of Wistar rats to 600 ppm compound A. Pretreatment with AOAA plus AT-125 increased necrosis to 57.9±32.6%, (P<0.005). PB or ABT given prior to compound A increased corticomedullary injury to 39.0±31.4% (P<0.02) and 51.2±31.8% (P<0.025), respectively. In rats exposed to 800 ppm compound A, pretreatment with AOAA increased necrosis from 63.8±30.1% to 81.2±27.7% (P<0.1). Unlike many other halogenated alkenes, compound A does not appear to produce renal injury by conversion of a cysteine S-conjugate to a toxic thiol, nor does injury require metabolism mediaited by cytochrome P-450. Injury may result from direct toxicity of compound A or by an undetermined metabolic pathway.

High resolution radiography of cadaveric kidneys: unraveling the mystery of Randall's plaque formation.

PURPOSE: We used high resolution radiography to identify and characterize Randall's plaques in cadaveric kidneys. MATERIALS AND METHODS: A total of 50 consecutive sets of cadaveric kidneys was fixed, bivalved and imaged with micro-focal spot magnification radiography. Papillary calcifications were identified, localized and processed for light microscopy. Special immunohistochemical stains were implemented to aid localization of ectopic calcifications. Patient medical records and autopsy results were retrospectively evaluated and correlated with radiographic papillary calcifications. RESULTS: Of the 92 renal units with complete data 52 (57%) had radiographic evidence of renal medullary calcifications consistent with Randall's plaques. Unlike the original description of this condition, calcifications extended deep into the papilla. A history of hypertension was the only clinical parameter correlating with papillary calcifications. Calcium deposition was localized to the basement membrane of collecting tubules and vasa recta, and papillary interstitium. CONCLUSIONS: Randall's plaques are not merely subepithelial deposits. Rather, they appear to extend deep within the papilla, and are intimately associated with collecting tubules and vasa recta. An association between papillary calcifications and urinary stone formation has yet to be proved but is under investigation.

Cutaneous Cryptococcus infection and AIDS. Report of 12 cases and review of the literature.

BACKGROUND: Cryptococcal infections occur in 6% to 13% of patients with acquired immunodeficiency syndrome (AIDS), most commonly infecting the central nervous system. Cutaneous lesions have been described morphologically as umbilicated papules, nodules, and violaceous plaques and can mimic molluscum contagiosum and Kaposi's sarcoma. Cutaneous lesions can present months prior to other signs of systemic infection. OBSERVATIONS: Cases of infection with cutaneous Cryptococcus and AIDS were reviewed and compared with cases reported in the literature. Among patients with Cryptococcus infection and AIDS seen at our institutions, 5.9% had skin lesions. All patients with cutaneous lesions had systemic involvement. Women were less commonly infected than men. There was no apparent predisposition associated with age, race, or human immunodeficiency virus infection risk factors. The median CD4 helper T-cell count was 0.024 X 10(9)/L (24/microL), and 44% (16/36) of the patients had previous opportunistic infections. Lesions were most commonly seen on the head and neck (78% [36/46]) and often mimicked molluscum contagiosum (54% [25/46]). The median serum and cerebrospinal fluid cryptococcal antigen titers were 1:32,768 and 1:512, respectively. Patients in our group did well with therapy (one death at 6 weeks, compared with 38% [13/34] mortality in the literature). There was no correlation between onset of lesions, number of lesions, CD4 helper T-cell count, or histopathologic characteristics. CONCLUSIONS: Disseminated Cryptococcus infection in AIDS presents with cutaneous lesions in up to 6% of cases. Clinicians need to be aware of the varied morphologic characteristics, since cutaneous lesions may present well in advance of other signs of systemic infection.

Metabolism of compound A by renal cysteine-S-conjugate beta-lyase is not the mechanism of compound A-induced renal injury in the rat.

Compound A [CF2 = C(CF3)OCH2F], a vinyl ether produced by CO2 absorbents acting on sevoflurane, can produce corticomedullary junction necrosis (injury to the outer stripe of the outer medullary layer, i.e., corticomedullary junction) in rats. Several halogenated alkenes produce a histologically similar corticomedullary necrosis by converting glutathione conjugates of these alkenes to halothionoacetyl halides. To test whether this mechanism explained the nephrotoxicity of Compound A, we blocked three metabolic steps which would lead to formation of a halothionoacetyl halide: 1) we depleted glutathione by administering dl-buthionine-S, R-sulfoximine (BSO); 2) we blocked cysteine S-conjugate formation by administering acivicin (AT-125); and 3) we inhibited subsequent metabolism by renal cysteine conjugate beta-lyase to the nephrotoxic halothionoacetyl halides by administering aminooxyacetic acid (AOAA). These treatments were given alone or in combination to separate groups of 10 or 20 Wistar rats before their exposure to Compound A. We hypothesized that blocking these metabolic steps should decrease the injury produced by breathing 150 ppm of Compound A for 3 h. However, we found either no change or an increase in renal injury, suggesting that this pathway mediates detoxification rather than toxicity. Our findings suggest that the cysteine-S-conjugate-mediated pathway is not the mechanism of Compound A nephrotoxicity and, therefore, observed interspecies differences in the activity of this activating pathway may not be relevant in the prediction of the nephrotoxic potential of Compound A in clinical practice.

Eccrine or apocrine poroma? Six poromas with divergent adnexal differentiation.

We describe six cases of benign eccrine poroma-like neoplasms with divergent adnexal differentiation. Four cases exhibited sebaceous differentiation in the form of individual or clustered sebocytes with or without sebaceous ducts. One case showed both sebaceous and hair follicle differentiation, and one case showed sebaceous and possible apocrine secretory differentiation. Clinically, most were skin-colored, red, or purple papules or nodules. One patient had a preoperative diagnosis of Bowen's disease, with an erythematous plaque. None recurred following biopsy. Previous reports of similar lesions have suggested a possible role for human papilloma virus (HPV) in their pathogenesis; however, immunohistochemical staining for HPV structural antigens was negative in all six of these cases. Similarities to previously reported cases of eccrine poroma-like neoplasms with sebaceous differentiation are discussed. Given the evidence of sebaceous and follicular differentiation seen in this study and the common embryologic origin of follicular, sebaceous, and apocrine structures, it follows that at least some benign neoplastic proliferations with histopathologic features of "eccrine" poroma could be of apocrine origin.

Cutaneous presentations of lymphoma in human immunodeficiency virus disease. Predominance of T cell lineage.

BACKGROUND AND DESIGN: Most non-Hodgkin's lymphomas in patients with human immunodeficiency virus infection are of B-cell lineage. Cutaneous lymphoma in the human immunodeficiency virus disease has not been systematically reviewed. We studied 25 patients with both human immunodeficiency virus infection and cutaneous presentations of lymphoma, using immunohistochemistry and in situ hybridization for Epstein-Barr virus. RESULTS: Two groups of patients were discerned: (1) those with conditions similar to mycosis fungoides or Sézary syndrome with an indolent course (n = 8) and (2) those with nodules or papules, greater immunosuppression, a rapid clinical course, and large cell lymphoma seen on biopsy specimens (n = 17). The epidermotropic lymphomas were T-cell lineage and CD30-. Thirteen of the large cell lymphomas were also of the T-cell type, and 71% were CD30+. Epstein-Barr virus was absent in the epidermotropic lymphomas, but it was present in 73% of the nonepidermotropic cases. CONCLUSIONS: Two forms of human immunodeficiency virus-associated cutaneous lymphoma were found: indolent disease resembling mycosis fungoides or Sézary syndrome and large cell lymphomas with a poor prognosis, whose cells often had a CD30+ T-cell phenotype and harbored the Epstein-Barr virus.

Nephrotoxicity in rats undergoing a one-hour exposure to compound A.

We previously demonstrated that rats experienced renal injury when exposed for 3-12 h to 50 ppm or more of a vinyl ether called Compound A [CF2 = C(CF3)OCH2F], a compound produced by CO2 absorbents acting on sevoflurane. These durations of exposure exceed the average duration of clinical anesthesia. We now report the effect of a 1-h exposure to 0, 100, 150, 200, 400, 600, or 800 ppm of Compound A in oxygen in 145 Wistar rats. Twenty-four hours after exposure, we obtained kidney and liver specimens for microscopic examination, applying hematoxylin and eosin, and (separately) an immunochemical marker (PCNA) for cell proliferation (regeneration). Compared with results from control rats (those breathing oxygen for 1 h), renal injury (defined as necrosis of the outer strip of the outer medullary layer or "corticomedullary junction necrosis") occurred at and above 200 ppm. Exposure to 150 ppm produced cell regeneration (i.e., stimulated cell proliferation). We conclude that the threshold concentrations for nephrotoxicity (i.e., minimal toxicity) for a 1-h exposure to Compound A exceed the maximum concentrations (particularly those at low inflow rates) reported in clinical practice by a factor of 2-3. If these threshold effects in rats apply to humans, one 1-h exposure to sevoflurane probably would not alter usual measures of renal function.

Normal vestibular function in chicks after partial exposure to microgravity during development.

Sixty-four fertilized chicken eggs, half at developmental Day 2 and half at Day 9, were exposed to micro-gravity for 5 days aboard the shuttle. Postflight examination showed that none of the Day 2 flight embryos had survived, whereas the Day 9 flight group and both groups of synchronous ground control embryos appeared viable. One-half of the Day 9 flight and ground control embryos were dissected and the temporal bones preserved in acetone for morphological examination. The other half was allowed to hatch to examine vestibularly related behavioral changes. Morphology of the lagenar otoconia was evaluated by scanning electron microscopy. Behavioral changes were accessed by a battery of reflex tests and recordings of spontaneous and vestibularly driven head movements. The results from both the morphological and behavioral studies showed no consistent difference between the flight and the control animals. Several hypotheses may account for this negative result. Because all the Day 2 embryos failed to survive, the remaining Day 9 chicks may have passed the critical developmental period of the chick's vestibular system. Also, the reexposure of the developing chick embryo to earth's 1-g environment may have masked any adverse behavioral effects that exposure to Microgravity may have caused.

Tumor angiogenesis correlates with lymph node metastases in invasive bladder cancer.

Neovascularization of tumor tissue (tumor angiogenesis) is considered essential for tumor growth, proliferation and eventually metastasis. Microvessel density or count, a measure of tumor angiogenesis, correlates with clinical outcome in skin, breast, lung and prostate carcinomas. To determine whether an association of tumor angiogenesis and nodal metastasis exists in invasive bladder cancer, microvessel counts in 41 primary invasive stages (T2 to 4,NX,M0) bladder cancers were assessed. Microvessels were identified by immunostaining of endothelial cells for factor VIII-related antigen. Microvessels were scored in selected areas showing active neovascularization, either counting a 200 x field (0.74 mm.2) or by using a 10 x 10 square ocular grid (0.16 mm.2). The microvessel count correlated with the presence of occult lymph node metastases (p < 0.0001) by both techniques. The mean microvessel count in 27 patients without lymph node metastases was 56.2 microvessels per 200 x field (standard deviation [SD] 29.5, range 7 to 130) or 28.6 microvessels per grid (SD 14.4, range 4 to 65). The 14 patients with histologically proved lymph node metastases showed mean 138.1 microvessels per 200 x fields (SD 37.9, range 82 to 202) or 74.7 microvessels per grid (SD 14.4, range 43 to 115). Good correlation was noted between area and grid counting (r = 0.97). Tumor T stage, grade and the presence of vascular or lymphatic invasion did not correlate with the presence of lymph node metastases (p = 0.41, 0.59 and 0.26, respectively). Microvessel count may provide important information regarding the risk of occult metastasis in patients with invasive bladder carcinomas.

c-myc copy number gains in bladder cancer detected by fluorescence in situ hybridization.

Amplification and overexpression of c-myc have been suggested as prognostic markers in human cancer. To assess the role of c-myc gene copy number alterations in bladder cancer, 87 bladder tumors were examined for c-myc aberrations by fluorescence in situ hybridization. Dual labeling hybridization with a repetitive pericentromeric probe specific for chromosome 8 and a probe for the c-myc locus (at 8q24) was performed to analyze c-myc copy number in relation to chromosome 8 copy number on a cell by cell basis. A clear-cut c-myc amplification (up to 40 to 150 copies per cell) was found in 3 tumors. There was a low level c-myc copy number increase in 32 of the remaining 84 tumors. There was no association of low level c-myc copy number increase with c-myc protein overexpression. This suggests that a c-myc gene copy number gain as detected by fluorescence in situ hybridization does not necessarily reflect a disturbed c-myc gene function but may indicate a structural chromosome 8 abnormality including gain of distal 8q. The strong association of low level c-myc (8q) gains with tumor grade (P < 0.0001), stage (P < 0.0001), chromosome polysomy (P < 0.0001), p53 protein expression (P = 0.0019), p53 deletion (P = 0.0403), and tumor cell proliferation (Ki67 labeling index; P = 0.0021) is consistent with a role of chromosome 8 alterations in bladder cancer progression.