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Kenneth A Iczkowski

Publications and source records attributed to Kenneth A Iczkowski.

32 records · Page 2Linked to original sources
PubMed2004

Metafectene is superior to lipofectamine in the transfection of G(s) alpha prostate cancer cells.

Transfection efficiency of the novel reagent metafectene has not been compared with that of lipofectamine in the published English literature. We used these agents to transfect two prostate cancer cell lines, PC3 and G(s) alpha, with a deoxyribonucleic acid (DNA) expression vector that generates double-stranded ribonucleic acid (RNA) for RNA interference (RNAi). Cotransfection of the green fluorescent protein (GFP) reporter gene revealed that the mean (+/- standard deviation) transfection efficiencies with lipofectamine were 5.8+/-0.4% for PC3 cells and 3.6+/-1.5% for G(s) alpha cells. Mean transfection efficiency with metafectene declined to 0.1+/-0% for PC3 cells but improved to 54.6+/-5.5% for G(s) alpha cells. With G(s) alpha cells, metafectene transfection of GFP plasmid alone yielded 46.9% positive cells, and cotransfection with CD44v9 expression vector yielded 45.9% positive cells. The visual impact of the transfected RNAi construct was detectable at the protein level 4 to 6 d posttransfection and was more dramatic after using metafectene than after using lipofectamine. Thus, in vitro, metafectene transfection efficiency was sufficient to allow us to assess the functional significance of our RNAi construct, suggesting metafectene as an excellent candidate for RNAi-mediated anticancer gene therapy.

Biotechnology↗
PubMed2003

Intraepithelial and stromal lymphocytes in the normal human prostate.

BACKGROUND: The distribution and significance of lymphocytes in the normal human prostate is uncertain. It may be important as a determinant of the immune response, playing a role in hyperplasia and carcinogenesis. METHODS: We studied 28 normal autopsy prostates from patients between 1 and 64 years of age. Cases with nodular hyperplasia, intraepithelial neoplasia, cancer, and florid prostatitis were excluded. Each prostate was routinely processed to paraffin and immunohistochemically stained for CD20, CD45, and CD45RO. Three frozen samples obtained from these cases were stained for CD8 and CD4. One low power field (25 x magnification, 50 mm(2)) was randomly chosen for examination from each anatomic zone of the prostate, namely the peripheral, transition, and central zone. Lymphocytes were visually counted in the stroma and epithelium of each zone. Lymphocyte counts were converted to number of cells per square millimeter based on the area of the slide per field and the percentage of field that was glandular. RESULTS: Stromal lymphocytes were more numerous than epithelial lymphocytes (mean, 7.32 and 2.04 cells/mm(2), respectively). They were mostly T cells (stromal lymphocytes: 93% CD45RO +; epithelial lymphocytes: 99% CD45RO +). Helper/inducer (CD4 +) T cells predominated in the stroma, whereas those in epithelium were chiefly cytotoxic/suppressor (CD8 +). No difference was found in the number of stromal and epithelial T or B cells according to patient age, race, or location within the prostate (peripheral, central, and transition zones) (all P > 0.05), although the number of lymphocytes in the peripheral zone tended to exceed that in the other zones after correcting for gland:stroma ratio. CONCLUSIONS: The immune response in the prostate is primarily cell-mediated. Cell distribution is constant according to patient age, race, and anatomic zonal location within the prostate. The greatest concentration is in the stroma with a small but significant number of intraepithelial cells. The inverted CD4/CD8 ratio in the intraepithelial compartment suggests that cytotoxic/suppressor T cells are the first line of defense against luminal foreign agents reaching the prostate through retrograde flow.

Adolescent↗
PubMed2003

Adenoid cystic/basal cell carcinoma of the prostate: clinicopathologic findings in 19 cases.

Adenoid cystic/basal cell carcinoma (ACBCC) of the prostate has been considered to have indolent biologic potential. However, outcome data are scant, with only one documented metastasis and death. We describe clinicopathologic features of ACBCC in 19 patients and document outcome in 15. Patients ranged in age from 43 to 83 years. All but one presented with urinary obstruction. ACBCC was diagnosed by transurethral resection in 15 cases, by needle biopsy in 3 cases, and unexpected in 1 case. Four patients had concurrent acinar adenocarcinoma. Histologically, cribriform or adenoid cystic patterns predominated in 12 cases and basal cell carcinoma pattern in 7. Five cases had prominent perineural invasion. ACBCC was immunoreactive for p63 and cytokeratins 7 and 34 beta E12 but not cytokeratin 20. After diagnosis, 5 patients underwent radical prostatectomy, 2 underwent pelvic exenteration, and the rest had no treatment. ACBCC showed extraprostatic extension in 5 cases and involved the bladder margin in 3. Metastases developed in 4 (21%) patients: liver (2), lung (2), bowel (1), and corpus cavernosum (1). In 15 cases with follow-up (0.3-11.8 years), two patients died of cancer (at 1.5 and 3 years after diagnosis), 3 remain alive with cancer, and 10 have no evidence of cancer. Thus, ACBCC of the prostate is a potentially aggressive neoplasm requiring ablative therapy.

Adult↗
PubMed2003

Overexpression of NSAID-activated gene product in prostate cancer.

NSAID-activated gene (NAG-1) protein was previously identified by microarray analysis as overexpressed in prostate cancer. We performed immunohistochemistry and Western blotting with rabbit polyclonal antibody to NAG-1. Fifty malignant tissues obtained by prostatectomy and 17 from benign cases were compiled. Cancer tissues included Gleason scores 3-6, 3+4=7, 4+3=7, and 8-10. Cancer and high-grade prostatic intraepithelial neoplasia (PIN) consistently showed moderate to intense cytoplasmic reactivity in 95-100% of epithelium. Staining intensity inversely correlated with preoperative serum prostate-specific antigen (PSA) (p=0.005) and with grade, averaging (on a 0 to 3+ scale) 2.3 +/- 0.6 in the lowest grade group, and 2.0 +/- 0.7, 1.8 +/- 0.5, and 1.5 +/- 0.6 as grade increased (p<0.008). Benign epithelium was nonreactive in 17/17 specimens without concurrent cancer (11 transurethral resection, 2 enucleation, 4 biopsy, p=0.002). Decreased NAG-1 expression in higher grade cancer is consistent with its known antitumorigenic, proapoptotic activities.

Biomarkers, Tumor↗
PubMed2002

Telomerase reverse transcriptase subunit immunoreactivity: a marker for high-grade prostate carcinoma.

BACKGROUND: Telomerase, a ribonucleoprotein complex that maintains telomeric DNA, has been detected in 67-93% of prostate carcinomas by telomeric repeat-amplification protocol assay (involving polymerase chain reaction). One study used in situ hybridization in nine patients; however, to date, no immunohistochemical results have been published. METHODS: From two hospitals, the authors compiled data on 62 patients who underwent prostatectomy from January 1996 to May 2001. Representative tissue sections were immunostained with a polyclonal antibody to telomerase reverse transcriptase (TERT), the catalytic subunit of telomerase. Staining was evaluated by two observers and was correlated with grade, stage, and biochemical failure. There were 28 sections from low-grade to intermediate-grade tumors (Gleason score, 3-6), 14 sections with a Gleason score of 3 + 4 = 7, 9 sections with a Gleason score of 4 + 3 = 7, and 11 sections from high-grade tumors (Gleason score, 8-10). RESULTS: From low-grade to high-grade tumors, the four groups described above disclosed nuclear reactivity in 64%, 100%, 100%, and 100% of sections, respectively. Mean percentages of 5%, 15%, 40%, and 51% of nuclei were reactive in the respective groups (P < 0.0001) with intratumoral heterogeneity. The percent of reactive tumor nuclei was not correlated with pathologic stage (P = 0.32) or margin status (P = 0.35). The basal cell layer in sections of high-grade prostatic intraepithelial neoplasia (HGPIN) and benign/atrophic acini was reactive; secretory cells were reactive in 13 of 34 HGPIN foci (38%) in 1-20% of nuclei and were never reactive in benign acini. Lymphocytes and skeletal muscle were reactive. Weak, nonspecific, cytoplasmic staining was noted in benign and tumor acini. CONCLUSIONS: Like cytokeratin 34betaE12, nuclear anti-TERT reactivity is a basal cell marker in nonneoplastic prostatic acini. Anti-TERT reactivity is acquired by secretory cells in tumorigenesis, but consistent reactivity is restricted to high-grade carcinoma (Gleason primary pattern >or=4). This histologic evidence suggests that higher grade tumors have maximally activated telomerase and may be most responsive to antitelomerase therapy.

Adenocarcinoma↗
PubMed2002

Needle core length in sextant biopsy influences prostate cancer detection rate.

OBJECTIVES: Prostate cancer detection in biopsies increases with the number of sites and total tissue sampled. Its dependence on needle core fragment length is uncertain. METHODS: We surveyed two consecutive series of sextant needle biopsies from two practices in 1998 to 2000: 251 patients from Pennsylvania (group P) and 1596 from Virginia (group V). We tabulated the gross needle core lengths per sextant site and classified the diagnoses as benign or into four nonbenign categories: high-grade prostatic intraepithelial neoplasia; atypical small acinar proliferation, suspicious; atypical small acinar proliferation, suspicious plus high-grade prostatic intraepithelial neoplasia; and cancer. Logistic regression analysis was used to correlate cancer or a nonbenign diagnosis with the total length (sum of six sites) and, after excluding the sites with more than one core, with the length per single core, and the anatomic site of origin (apex, mid-gland, base). RESULTS: The mean total tissue length sampled was 108 +/- 27 mm (range 30 to 275) in group P and 81 +/- 22 mm (range 30 to 228) in group V. Sextant sites with a single core contained a mean of 12.8 +/- 3.5 mm tissue, with a 3.6-fold variation among the middle 95%. Group V core lengths at the apex averaged 11.8 mm, shorter (P = 0.0001) than mid (13.3 mm) or base (12.7 mm). A predictive value of longer length for a nonbenign diagnosis was noted in four of six sextants (P <0.04), with trend strongest at the apex, for which detection was influenced by abnormal digital rectal examination (P = 0.02) or ultrasound (P = 0.04) findings. CONCLUSIONS: The length of single cores sampled by sextant biopsy can vary more than 3.6-fold and represents a quality assurance consideration. The effect of length on cancer or nonbenign detection was maximal at the prostatic apex where the cores were shortest.

Biopsy, Needle↗
PubMed2002

Prostate cancer diagnosed after initial biopsy with atypical small acinar proliferation suspicious for malignancy is similar to cancer found on initial biopsy.

OBJECTIVES: To compare matched clinical and prostatectomy data between (a) men with an initial biopsy diagnosis of atypical small acinar proliferation (ASAP) suspicious for malignancy whose cancer was diagnosed subsequently, and (b) men with a cancer diagnosis not preceded by an ASAP diagnosis. ASAP diagnoses apply to 1.5%-9.0% of prostatic biopsies and predict definite cancer in about 45% of repeat biopsies. METHODS: At our hospitals, during overlapping intervals from 1990 to 2001, 7081 men underwent prostate biopsy, and 227 (3.2%) had an overall diagnosis (based on all cores sampled) of ASAP. We concurred with the ASAP diagnosis in 184 cases (81%). Repeat biopsy was performed in 129 (57%), with 22 again having ASAP and 51 (40%) adenocarcinoma. Nineteen men underwent prostatectomy at our hospitals. The controls comprised men who underwent prostatectomy before and after each man with an initial ASAP diagnosis (2:1 match with cases). Findings included grade, pathologic stage, measured maximum dimension of tumor, resection margin status, patient age, and latest preoperative serum prostate-specific antigen. RESULTS: Men in the initial-ASAP group did not differ significantly from controls with respect to age (63 vs. 61, P = 0.08). Initial-ASAP and control groups had serum prostate-specific antigen levels of 5.9 and 7.4 ng/mL (P = 0.32), respectively; mean Gleason scores were 6.2 and 6.6 (P = 0.11); mean stages were pT2b and pT2b; and tumor size averaged 0.9 and 1.2 cm (P = 0.36). Fewer men with initial-ASAP diagnosis on biopsy had positive margins (5%) than did those in the control group (30%, P < 0.05). CONCLUSIONS: An ASAP diagnosis represents undersampled cancer in at least 40% of cases and places men at risk of prostate cancer with similar clinicopathologic findings as in other men with cancer.

Adenocarcinoma↗
PubMedDate not supplied

Comamonas (Pseudomonas) testosteroni endocarditis.

Comamonas testosteroni has rarely been implicated as a human pathogen. We report a case of infectious endocarditis due to this organism, occurring in a 49-year-old man. The posterior leaflet of the mitral valve contained a 1 x 1 cm vegetation and showed myxoid degeneration and acute inflammation. The patient had no evidence of reinfection after 32 months. The infection was almost certainly community acquired, as is usually true for this organism.

Anti-Bacterial Agents↗
PubMedDate not supplied

Lobular carcinoma of the breast metastatic to the epidural space: a potential mimic of giant cell bone tumor.

We report the case of a 64-year-old woman with a spinal epidural mass. Tissue from a decompression laminectomy disclosed a tumor with numerous osteoclast-like giant cells separated by small, moderately atypical tumor cells. The osteoclast-like giant cells were immunoreactive for vimentin, but negative for epithelial membrane antigen and broad-pectrum cytokeratin. Subsequent breast biopsy revealed a lobular carcinoma of classic type without osteoclast-like giant cells. This is the first reported case in which metastatic breast carcinoma was accompanied by these giant cells but the giant cells were not present at the primary tumor site.

Breast Neoplasms↗
PubMedDate not supplied

Postoperative bladder washing cytology after transurethral resection. Can it predict the recurrence of urothelial carcinoma?

OBJECTIVE: To assess the ability of postoperative bladder washing cytology, performed immediately after transurethral resection of mostly stage Ta or T1 papillary urothelial carcinoma, to predict early recurrence. STUDY DESIGN: In a 1-year period, preoperative and postoperative bladder washing cytology specimens were sampled from patients undergoing transurethral resections in which all visible tumor was removed. There were 38 resections in 32 patients. RESULTS: Postoperative cytology was satisfactory in 35 of 38 cases and positive in 17 (49%) after a mean of 6.9 months. Follow-up of these 35 transurethral resections disclosed a 15/17 (88%) recurrence rate after positive cytology and a 4/18 (22%) recurrence rate after negative cytology (P < .001). Postoperative cytology demonstrated a sensitivity for recurrence of 79%, specificity of 88%, positive predictive value of 88% and negative predictive value of 77%. In contrast, tumor in the transurethral resection specimen had a positive predictive value of 54% for recurrence, and its grade and stage were inferior to cytology in predicting recurrence. CONCLUSION: Postoperative bladder washing cytology is a useful adjunct to the management of papillary urothelial carcinoma. A positive result, signifying residual tumor, should encourage prompt follow-up and possibly repeat transurethral resection.

Aged↗
PubMedDate not supplied

Prostate cancer overexpresses CD44 variants 7-9 at the messenger RNA and protein level.

BACKGROUND: In prostate cancer, prior data show down-regulated immunohistochemical expression of cell adhesion protein CD44 standard (CD44s) and most variants (CD44v). MATERIALS AND METHODS: Expression of CD44 mRNA was studied by RT-PCR and cDNA sequencing in 19 prostate cancers and 10 benign controls. Immunohistochemical staining was performed with anti-CD44v7/8 in 80 prostatectomy specimens, and 12 were used for in situ hybridization for CD44v7 (exon 12). Western blotting with monoclonal antibody to CD44 standard, v6, v7/8, or v9 was performed using cancerous and benign prostate. RESULTS: Sequencing of RT-PCR products showed that benign tissue and cancer express CD44 standard and v10 mRNA at 482 base pairs (bp). In contrast, cancer tissues also overexpressed 800-1000 bp bands corresponding to v7-9 isoforms. In situ hybridization revealed increased CD44v7 signal in cancer compared to benign acini. Immunostaining for CD44v7/8 was increased, proportional to Gleason grade. By Western blot, cancer and benign tissue disclosed major bands of reactivity at 75-100 kD consistent with intact standard and variant isoforms. Tumors, however, had 6-45 kD bands for CD44 standard, v7/8 and v9, consistent with cleavage products. CONCLUSION: CD44 v7-9 isoform messenger RNA is increased in prostate cancer, and translation yields low molecular weight polypeptides of probable cleavage origin.

Blotting, Western↗
PubMedDate not supplied

Paracrine calcitonin in prostate cancer is linked to CD44 variant expression and invasion.

BACKGROUND: Calcitonin (CT) exerts an autocrine/paracrine influence on prostatic tumor invasion through coupling to transduction protein Gsalpha. Cell adhesion glycoprotein CD44 variant v7-v10 also faciliates invasion, but its modulation by the CT-Gsalpha system was unexplored. MATERIALS AND METHODS: LnCaP, PC-3 and metastasis-derived PC-3M cell lines were studied, including cells modified therefrom: Gsalpha-QL, expressing mutant constitutively active Gsalpha protein, and CT+, overexpressing CT. CD44 variant expression was evaluated in vivo after orthotopic implantion into nude mice, and in vitro by real-time RT-PCR and Western blotting. RESULTS: Both mRNA and protein levels of the CD44 variant were minimal in PC-3M tumor implants, but elevated in Gsalpha-QL. Exogenous CT stimulated invasion into Matrigel strongly in LnCaP and CT+, and less in PC-3 and Gsalpha-QL. By Western blot analysis, untreated Gsalpha-QL and CT+ cells overexpressed CD44 variant compared with LnCaP or PC-3. By quantitative RT-PCR, exogenous CT dose-dependently increased CD44 variant mRNA to seven-fold. Pharmacologic agents that stimulated or inhibited Gsalpha activity or stimulated adenylyl cyclase produced proportionate dose-dependent effects on both CD44 variant expression and Matrigel invasion. CONCLUSION: This paracrine factor, acting though cyclic AMP, regulates the expression of CD44v7-10, which modulates the tumor phenotype.

Adenylyl Cyclases↗
PubMedDate not supplied

The predominant CD44 splice variant in prostate cancer binds fibronectin, and calcitonin stimulates its expression.

BACKGROUND: Prostate cancer (PC) consistently overexpresses variant the (v) isoform of the cell adhesion protein CD44, and loses expression of the standard (s) isoform. MATERIALS AND METHODS: We re-expressed CD44 full-length (exons 1-20) or standard (exons 1-5 + 16-20) or enforced stable RNAi against CD44v, and the examined functional effects on PC. The effect of stable knockout of calcitonin, a paracrine factor, or its receptor, on CD44 was assessed. RESULTS: Re-expression of full-length CD44 or CD44s increased the total CD44 mRNA and CD44s protein while suppressing CD44v. These approaches, and RNAi to CD44v, decreased invasion. In adhesion assays, benign prostate cells bound mainly to hyaluronan, whereas PC lost affinity for hyaluronan but bound more strongly to fibronectin. Re-expressing CD44s restored predominant hyaluronan binding. Knockout of the calcitonin receptor in PC-3 derived cells caused marked loss of CD44v expression and reversion to CD44s expression. CONCLUSION: Calcitonin influenced PC's balance between CD44s and CD44v. CD44v controlled invasiveness, altered ligand binding, and provides a target for therapeutic intervention.

Alternative Splicing↗