Tumorigenicity and genotoxicity of an environmental pollutant 2,7-dinitrofluorene after systemic administration at a low dose level to female rats.

Environmental pollution with nitroaromatic compounds may pose health hazards. We have examined the tumorigenicity in female Sprague-Dawley rats of 2,7-dinitrofluorene (2,7-diNF) and 9-oxo-2,7-diNF administered by intraperitoneal (i.p.) and oral routes at 10 micromol/kg body weight, 3 times per week for 4 weeks. After i.p. treatment, the estimated median latency for the combined malignant and benign mammary tumors was decreased in 2,7-diNF- (p = 0.003) or 9-oxo-2,7-diNF-treated (p = 0.007), relative to vehicle-treated rats (42 or 64 vs. 80 weeks, respectively), whereas after oral dosing, there were no significant differences. At 90 weeks, the malignant mammary tumor incidence in 2,7-diNF-, 9-oxo-2,7-diNF- and vehicle-i.p. treated rats was 44 (p = 0.02 vs. vehicle-treated), 25 and 6%, respectively. Liver and mammary gland DNA was analyzed by HPLC combined with electrospray tandem mass spectrometry for the presence of a deoxyguanosine (dG-2,7-diNF) adduct and a deoxyadenosine (dA-2,7-diNF) adduct derived from 2,7-diNF, and a deoxyguanosine (dG-9-oxo-2,7-diNF) adduct derived from 9-oxo-2,7-diNF. Both dG-2,7-diNF and dA-2,7-diNF were detected in DNA of 2,7-diNF-treated rats, whereas only very low levels of dG-9-oxo-2,7-diNF were detected in DNA of 9-oxo-2,7-diNF-treated rats. After i.p. treatment, the dA-2,7-diNF level was higher (p < 0.01) in the mammary gland than liver (13.6 vs. 7.8 adducts/10(8) nucleotides). In the mammary gland, the dG-2,7-diNF level was higher (p < 0.05) after i.p. than oral dosing and also higher (p < 0.05) than in the liver (36 vs. 8.6 and vs. 9.1 adducts/10(8) nucleotides, respectively). The preferential display of carcinogenicity and genotoxicity in the mammary gland by low doses of 2,7-diNF signifies its potential relevance for environmental breast cancer.

Plaque-type syringoma: two cases misdiagnosed as microcystic adnexal carcinoma.

BACKGROUND: Plaque-type syringoma is a rare variant of syringoma. This benign neoplasm may be easily misdiagnosed as microcystic adnexal carcinoma (MAC), potentially resulting in unnecessary surgery with disfiguring consequences. METHODS: We report two cases of plaque-type syringoma that were initially diagnosed as MAC. Microscopically, these lesions were composed of nests of cuboidal cells arrayed within sclerotic collagen in the upper dermis. The deep reticular dermis was spared. No perineural involvement was observed. RESULTS AND CONCLUSIONS: Our cases are discussed in the context of histopathologic diagnosis. Detailed histopathologic findings of syringoma, as well as other considerations in the differential diagnosis, are reviewed. We also include a review of all cases of plaque-type syringoma published to date.

Suppression of mammary gland carcinogenesis by post-initiation treatment of rats with tamoxifen or indole-3-carbinol or their combination.

This study examined whether suppression of mammary gland carcinogenesis elicited by low doses of tamoxifen (TAM) can be enhanced by concomitant treatment of rats with indole-3-carbinol (I3C), a component of cruciferous vegetables and a dietary supplement used for its putative antiestrogenicity. Two weeks after one oral dose of 7,12-dimethylbenz[a]anthracene (DMBA) at 65 mg/kg body weight, female Sprague-Dawley rats started treatment with TAM (10 microg/rat) by subcutaneous injection, I3C (250 mg/kg body weight) by oral gavage, TAM+I3C or their respective vehicles three times per week, for up to 20 weeks. Significant increases in the median latency of malignant mammary tumors and decreases in the mean tumor mass per rat were due to TAM. Significant decreases in the mean tumor number per rat in TAM, I3C and TAM+I3C-treated rats indicated a cooperative effect of the two compounds. In both DMBA-initiated and uninitiated rats, significant increases in the ratios of liver to body weight in I3C and TAM+I3C-treated groups coincided with I3C-dependent increases of hepatic cytochrome P450 levels and activities (1A1, 1A2 and 2B1/2). The ratios of uterus to body weight decreased with the number of treatments and the decreases effected by TAM were greater than those by I3C. The levels of circulating estrone were increased in response to I3C treatment and were greater in DMBA-initiated rats than in uninitiated rats, which may contribute to the preventive effect of I3C. Chemoprevention may be accomplished through up-regulation of apoptotic enzyme (caspase) activities in the mammary gland or mammary tumors. Treatment with TAM, I3C or TAM+I3C had no effect on caspase-3&7, caspase-6, caspase-8 and caspase-9 activities in the mammary tumors or mammary gland of tumor-bearing rats or that of uninitiated rats. In the mammary gland of DMBA-initiated tumor-free rats, however, I3C treatment increased the levels of caspase-3&7 and caspase-9 activities, suggesting an I3C-mediated protective effect. Even though I3C alone is a much less effective suppressing agent of mammary carcinogenesis than TAM, I3C in combination with TAM does not weaken but may foster the benefits of chemoprevention with TAM.

Gefitinib in patients with malignant mesothelioma: a phase II study by the Cancer and Leukemia Group B.

PURPOSE: The Cancer and Leukemia Group B conducted a phase II study of gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, in patients with previously untreated malignant mesothelioma. EXPERIMENTAL DESIGN: Eligible patients had unresectable pleural or peritoneal mesothelioma, measurable disease, no prior therapy, and performance status 0-1 by Cancer and Leukemia Group B criteria. Gefitinib (500 mg p.o.) was administered once a day for 21 days. Patients underwent restaging after every two cycles. Therapy was continued until disease progression or unacceptable toxicity. RESULTS: The most common grade 3 toxicities were diarrhea (16%) and nausea (12%). Of 43 patients enrolled, 1 patient (2%) had a complete response, 1 patient (2%) had a partial response, 21 (49%) had stable disease lasting two to eight cycles, 15 (35%) had progressive disease, and 5 (12%) had early deaths. One-year survival was 32% [95% confidence interval (CI), 21-50%]. Median survival and failure-free survival were 6.8% (95% CI, 3.5-10.3) and 2.6 months (95% CI, 1.5-4.0), respectively. The 3-month failure-free survival was 40% (95% CI, 25-56%). EGFR expression score by immunohistochemistry done in 28 patients was categorized as low (EGFR 1+ or 2+) or high (EGFR 3+) expression: 97% had EGFR overexpression (2+ or 3+). The median and 3-month failure-free survival were 3.6 months and 40% for those patients with low EGFR expression compared with 8.1 and 40% for those with high EGFR expression. CONCLUSIONS: Although 97% of patients with mesothelioma had EGFR overexpression, gefitinib was not active in malignant mesothelioma. EGFR expression does not correlate with failure-free survival.

CK2 targeted RNAi therapeutic delivered via malignant cell-directed tenfibgen nanocapsule: dose and molecular mechanisms of response in xenograft prostate tumors.

CK2, a protein serine/threonine kinase, promotes cell proliferation and suppresses cell death. This essential-for-survival signal demonstrates elevated expression and activity in all cancers examined, and is considered an attractive target for cancer therapy. Here, we present data on the efficacy of a tenfibgen (TBG) coated nanocapsule which delivers its cargo of siRNA (siCK2) or single stranded RNA/DNA oligomers (RNAi-CK2) simultaneously targeting CK2α and α' catalytic subunits. Intravenous administration of TBG-siCK2 or TBG-RNAi-CK2 resulted in significant xenograft tumor reduction at low doses in PC3-LN4 and 22Rv1 models of prostate cancer. Malignant cell uptake and specificity in vivo was verified by FACS analysis and immunofluorescent detection of nanocapsules and PCR detection of released oligomers. Dose response was concordant with CK2αα' RNA transcript levels and the tumors demonstrated changes in CK2 protein and in markers of proliferation and cell death. Therapeutic response corresponded to expression levels for argonaute and GW proteins, which function in oligomer processing and translational repression. No toxicity was detected in non-tumor tissues or by serum chemistry. Tumor specific delivery of anti-CK2 RNAi via the TBG nanoencapsulation technology warrants further consideration of translational potential.

Quantification of colorectal cancer micrometastases in lymph nodes by nested and real-time reverse transcriptase-PCR analysis for carcinoembryonic antigen.

PURPOSE: Reverse-transcriptase PCR (RT-PCR) assays for carcinoembryonic antigen (CEA) have been described to identify lymph node micrometastases. These assays are not quantitative and can be confounded by false-positive results. The purpose of this study was to determine whether quantification of CEA in lymph nodes could more readily identify clinically relevant groups. EXPERIMENTAL DESIGN: Specimens included 400 lymph nodes from 64 patients undergoing colon resections. Specimens were tested by immunohistochemistry and by RT-PCR using nested primers for CEA. Specimens from 59 patients that were positive by nested RT-PCR were further quantified by detection of CEA mRNA fluorescence increase at a threshold PCR cycle. RESULTS: CEA was detected by nested RT-PCR analysis in 4 of 34 (12%) nodes of nonneoplastic disease, 2 of 13 (15%) nodes from T(1)N(0) patients, 32 of 81 (40%) nodes of T(2)N(0) patients, 49 of 109 (45%) nodes from T(3)N0 patients, and 92 of 163 (56%) nodes from T(1-4)N(1-2) patients. The overall presence of any RT-PCR-detectable CEA in nodes did not differentiate patient groups. Immunohistochemistry was positive in nodes from 7% of T(3)N(0) patients and 100% of T(1-3)N(1-2) patients. CEA quantification revealed that 0 of 7 patients with nonneoplastic disease and 2 of 17 (12%) patients with stage I T(1-2)N(0) cancers had one or more lymph nodes with >/=1.0 x 10(2) CEA transcripts per sample. In contrast, 4 of 13 (31%) patients with stage II T(3)N(0) cancer and 10 of 22 (45%) stage III patients with known metastases had lymph nodes with >/=1.0 x 10(2) CEA transcripts. CONCLUSIONS: These data suggest that quantification of CEA levels in lymph nodes may more accurately identify patients at risk for cancer recurrence than does routine nested RT-PCR or immunohistochemistry.

The pattern of CD10 expression in selected pathologic entities of the prostate gland.

There is increasing evidence that neuropeptides, including bombesin, may influence growth, angiogenesis, invasiveness, and metastasis in prostate cancer. One of the molecules tightly involved in the regulation of neuropeptide activity is the integral membrane glycoprotein CD10, or neutral endopeptidase 24.11. The pattern of CD10 expression in hyperplastic and neoplastic conditions of the prostate gland has not been previously described. Immunohistochemical staining for CD10 and high-molecular-weight cytokeratin was performed on 92 cases of paraffin-embedded tissue from needle-core biopsy specimens and prostatectomy specimens. Normal and hyperplastic acini showed strong and distinct membrane (apical and intercellular) and cytoplasmic CD10 expression in basal and secretory cells. In contrast, no intercellular membrane or cytoplasmic staining of secretory cells was seen in any cases of adenocarcinoma with Gleason patterns 2 or 3. A subset of high-Gleason grade adenocarcinoma (patterns 4 and 5) displayed CD10 expression in the secretory cells; those cases shared a distinct morphological pattern. Prostatic intraepithelial neoplasia (PIN) showed consistent absence of intercellular membrane and cytoplasmic CD10 expression in the secretory cells, with preserved expression in basal cells. Interestingly, the basal cells in basal cell hyperplasia lacked CD10 expression, and no expression was noted in the secretory cells in all cases examined. Atrophic acini and those associated with acute and chronic inflammation retained CD10 expression. In conclusion, a consistent differential pattern of CD10 expression was seen in basal cell hyperplasia, PIN, and adenocarcinoma, suggesting a role for CD10 in the pathobiology of the prostate gland.

"Burned out" testicular seminoma presenting as a primary gastric malignancy.

In contrast to primary gastric adenocarcinomas, germ cell tumors are potentially curable even when metastatic. It is therefore essential for clinicians and pathologists to be aware of the spectrum of unusual manifestations of germ cell malignancies. Here we report on a 55-year-old man who presented with clinical and endoscopic features indicative of a primary gastric carcinoma. Surprisingly, the ulcerative mucosal lesion was found to be due to a metastasis from an occult, "burned-out" testicular seminoma. This case describes the radiological and pathological features that helped differentiate this rare situation from the much more common gastric adenocarcinoma, and extends the diagnostic possibilities that must be considered in patients presenting with gastric ulcers.