Biomedical subjects

John L Farber

Publications and source records attributed to John L Farber.

13 recordsLinked to original sources

PubMed2006

Zinc deficiency potentiates induction and progression of lingual and esophageal tumors in p53-deficient mice.

Upper aerodigestive tract (UADT) cancer, including oral and esophageal cancer, is an important cause of cancer deaths worldwide. Patients with UADT cancer are frequently zinc deficient (ZD) and show a loss of function of the pivotal tumor suppressor gene p53. The present study examined whether zinc deficiency in collaboration with p53 insufficiency (p53+/-) promotes lingual and esophageal tumorigenesis in mice exposed to low doses of the carcinogen 4-nitroquinoline 1-oxide. In wild-type mice, ZD significantly increased the incidence of lingual and esophageal tumors from 0% in zinc sufficient (ZS) ZS:p53+/+ mice to approximately 40%. On the p53+/- background, ZD:p53+/- mice had significantly greater tumor incidence and multiplicity than ZS:p53+/- and ZD:p53+/+ mice, with a high frequency of progression to malignancy. Sixty-nine and 31% of ZD:p53+/- lingual and esophageal tumors, respectively, were squamous cell carcinoma versus 19 and 0% of ZS:p53+/- tumors (tongue, P = 0.003; esophagus, P = 0.005). Immunohistochemical analysis revealed that the increased cellular proliferation observed in preneoplastic lingual and esophageal lesions, as well as invasive carcinomas, was accompanied by overexpression of cytokeratin 14, cyclooxygenase-2 and metallothionein. In summary, a new UADT cancer model is developed in ZD:p53+/- mouse that recapitulates aspects of the human cancer and provides opportunities to probe the genetic changes intrinsic to UADT carcinogenesis and to test strategies for prevention and reversal of this deadly cancer.

4-Nitroquinoline-1-oxide↗

PubMed2006

The course of etoposide-induced apoptosis in Jurkat cells lacking p53 and Bax.

Jurkat T-lymphocytes lack p53 and Bax but contain p73 and Bid and are killed by etoposide (ETO). With ETO c-abl is phosphorylated and phosphorylated p73 increased. Translocation of full-length Bid to mitochondria follows, with induction of the mitochondrial permeability transition (MPT) and release of cytochrome c into the cytosol. Pronounced swelling of mitochondria was evident ultrastructurally, and the MPT inhibitor cyclosporin A prevented the release of cytochrome c. Overexpression of Bcl-2 prevented the translocation of Bid, the release of cytochrome c, and cell death. The pan-caspase inhibitor ZVAD-FMK prevented the cell killing, but not the initial release of cytochrome c. An accumulation of tBid occurred at later times in association with Bid degradation. A sequence is proposed that couples DNA damage to Bid translocation via activation of c-abl and p73. Bid translocation induces the MPT, the event that causes release of cytochrome c, activation of caspases, and cell death.

Amino Acid Chloromethyl Ketones↗

PubMed2006

Re-evaluation of the distinction between type I and type II cells: the necessary role of the mitochondria in both the extrinsic and intrinsic signaling pathways upon Fas receptor activation.

Cyclosporin A (CyA) and bongkrekic acid (BK) prevented Fas-induced apoptosis in two type I cell lines (H9 and SKW6.4) and two type II cell lines (Jurkat and CEM). CyA and BK inhibited the release of cytochrome c in all four cell lines. In type I cells and in CEM cells, CyA and BK did not prevent the translocation of Bax to the mitochondria. In these same cells, full-length Bid decreased in the mitochondria and cytosol. The cleavage product of Bid, tBid, appeared in the cytosol and to a lesser extent in the mitochondria. In Jurkat cells, Bid also decreased in the cytosol, but increased in the mitochondria. Similar to the other cells, tBid appeared in the mitochondria and cytosol. In the type I H9 and SKW6.4 cells and type II Jurkat cells, the caspase-8 inhibitor Z-Ile-Glu(OMe)-Thr-Asp(OMe)-CH2F (IETD) prevented the cell killing. In the type I cells, IETD prevented the translocation of Bax, the degradation of Bid and the accumulation of tBid. By contrast, IETD only marginally protected the type II CEM cells. In these cells in the presence of IETD, Bax translocated to the mitochondria, in the absence of any degradation of Bid or accumulation of tBid. In the type I H9 cells, IETD produced a depletion of ATP, an effect that did not occur in the type II CEM cells. It is concluded that in type I cells the extrinsic signaling pathway is mitochondrial dependent to the same extent as is the intrinsic pathway in type II cells.

Antibodies, Monoclonal↗

PubMed2006

Characterization of rejection episodes in patients following positive crossmatch and ABO-incompatible live donor renal transplantation.

For kidney transplant recipients with donor-specific antibody (DSA) to HLA- (+XM) or ABO-antigens (ABOI), there is a need to improve detection and treatment of antibody-mediated rejection (AMR). The methods included a retrospective review of consecutive patients that received plasmapheresis and immune globulin (PPIVIg) to abrogate +XM or ABOI. Twelve patients were transplanted after PPIVIg (+XM = 9, ABOI = 2, +XM/ABOI = 1). No hyperacute rejections occurred. Rejection occurred in seven patients [four AMR, three acute cellular rejection (ACR)]. In four +XM patients, DSA was detected during graft dysfunction despite lack of histologic and C4d features of AMR. In one patient, DSA preceded the histologic and immunofluorescent features of AMR. In another patient with borderline changes and DSA, graft function improved after PPIVIg, despite lack of histologic or immunofluorescent evidence of AMR. One patient with Banff IIA ACR and DSA treated with antithymocyte antibody but not PPIVIg had recurrent rejections and poor graft function. In +XM and ABOI recipients with graft dysfunction: (i) DSA may represent AMR in the absence of C4d or histologic features of AMR; (ii) DSA can precede C4d or light microscopic features of AMR; (iii) A poor outcome may result if DSA or continued allograft dysfunction is present and not treated despite a negative biopsy.

ABO Blood-Group System↗

PubMed2005

Knockout mice reveal a tumor suppressor function for Testin.

The Testin (TES) gene was previously identified as a putative human tumor suppressor gene at 7q31.2, a region that is frequently deleted in hematopoietic malignancies, as well as in epithelial tumors. To determine whether TES acts as a tumor suppressor in vivo, we generated a Tes knockout mouse and then used it in an established model of carcinogen-induced gastric cancer. In mice a zinc-deficient (ZD) diet enhances cellular proliferation in the forestomach and susceptibility to N-nitrosomethylbenzylamine (NMBA)-induced carcinogenesis. Five-week-old Tes wild-type (+/+), heterozygous (+/-), and homozygous (-/-) mice were divided into four groups: mice fed a zinc-sufficient diet (ZS); mice fed a ZD diet; ZS fed plus NMBA-treated mice (ZS+NMBA), and ZD fed plus NMBA-treated mice (ZD+NMBA). After 4 weeks, the ZS+NMBA and ZD+NMBA groups were treated with three intragastric doses of NMBA. Animals were killed 8 weeks after NMBA administration: 25% of +/+ mice developed benign lesions; 88% of +/- showed multiple papillomas, atypical glandular metaplasia, and squamous cell carcinomasl; and 81% of -/- mice displayed very large papillomas, squamous cell carcinomas, and adenocarcinomas. A statistically significant difference in tumor incidence was found between +/- versus +/+ and -/- versus +/+ (P < 0.0001). These data suggest that Tes functions as a tumor suppressor gene in vivo.

Adenocarcinoma↗

PubMed2005

Dietary zinc modulation of COX-2 expression and lingual and esophageal carcinogenesis in rats.

BACKGROUND: Cancer of the upper aerodigestive tract, including esophageal and tongue carcinomas, is a major cause of cancer deaths worldwide. Esophageal and tongue cancers have both been associated with dietary zinc deficiency (ZD), and cyclooxygenase (COX-2) is often overexpressed in these cancers. Using rat models, we examined whether zinc regulates COX-2 expression in these cancers. METHOD: Expression of COX-2 protein and mRNA in rat lingual and esophageal epithelia in control (zinc sufficient [ZS]) rats, during ZD, and after intragastric zinc replenishment (ZR) were determined by immunoblotting, immunohistochemistry, and real-time quantitative polymerase chain reaction. COX-2 gene expression, cell proliferation, and apoptosis were analyzed in ZD, ZR, and ZD rats treated with the COX-2 inhibitors celecoxib and indomethacin. Tumor development in ZD rats treated by continuous exposure to the carcinogen 4-nitroquinoline 1 oxide (NQO), which causes tongue tumors in rats, was compared with those in NQO-treated ZS rats. Statistical tests were two-sided. RESULTS: The esophagus and tongue of ZD rats were hyperplastic and expressed COX-2 protein and mRNA at 8- to 14.7-fold higher levels than control rats. Within hours ZR reduced COX-2 overexpression to threefold that in control rats and reversed the hyperplastic phenotypes. The esophagus of ZD rats treated with celecoxib or indomethacin showed a reduction in cell proliferation and stimulation of apoptosis. NQO treatment resulted in greater incidence of lingual squamous cell carcinomas (74% versus 22%, difference = 52%, 95% confidence interval [CI] = 20% to 80%, P = .015) and greater tumor multiplicity (13.1 versus 4.3, difference = 8.8, 95% CI = 7.0 to 10.6, P = .018) in ZD than ZS rats. Of 23 NQO-treated ZD rats, 39% (9) and 61% (14) harbored esophageal and forestomach tumors, respectively, whereas none of the NQO-treated ZS rats did. CONCLUSIONS: COX-2 overexpression accompanies hyperplasia in ZD rats. Increased cell proliferation in NQO-treated ZD rats facilitates the development of tumors at multiple sites. The finding that zinc regulates COX-2 expression in vivo in an animal model may lead to prevention or therapeutic possibilities for upper aerodigestive tract cancer.

4-Nitroquinoline-1-oxide↗

PubMed2004

Arterial invasion predicts early mortality in stage I non-small cell lung cancer.

BACKGROUND: A retrospective study was performed to evaluate the association between arterial invasion and survival in patients with stage I non-small cell lung cancer. METHODS: One hundred patients were identified who had undergone complete anatomic resection as definitive treatment for stage I non-small cell lung cancer. The tumors were reviewed for the presence or absence of arterial invasion. Five-year survival data were obtained for all patients. RESULTS: The 100 patients had an overall 5-year survival of 61%. There were 64 stage IA patients with a 62% 5-year survival and 36 stage IB patients with a 58% 5-year survival. The 39 patients identified with arterial invasion had a 38% 5-year survival compared with a 73% 5-year survival in the 61 patients without arterial invasion (p < 0.001), with an unadjusted hazard ratio of 3.5 (p < 0.001). Multivariate analysis by stage IA versus IB and by size greater or less than 2 cm demonstrated hazard ratios of 3.5 and 4.0, respectively (p < 0.001). This difference was independent of demographic characteristics, tumor type, or grade. Subgroup analysis revealed a hazard ratio of 5.8 in patients with stage IA non-small cell lung cancer (p < 0.001) and 19.8 in patients with tumors < or = 2 cm (p = 0.006). CONCLUSIONS: Arterial invasion is present in a substantial percentage of patients with stage I non-small cell lung cancer and is adversely associated with survival.

Aged↗

PubMed2004

Successful living donor renal transplantation despite ABO incompatibility and a positive crossmatch.

Potential live kidney donors have been rejected when the prospective recipients are blood type or crossmatch incompatible. By utilizing plasmapheresis combined with intravenous immune globulin (PP/IVIg) prior to surgery, donor-specific antibodies against blood group or human leukocyte antigens (HLA) have been removed, thereby allowing successful renal transplantation. A 26-yr-old male with a panel reactive antibody level of 100% and repeated positive crossmatches against deceased donor kidney offers, including zero HLA mismatched donors, successfully underwent ABO-incompatible kidney transplantation from his HLA-identical but nevertheless crossmatch-incompatible sister. The initial anti-A blood group isoagglutinin titers were 128, 256, and 1024 at room temperature, 37 degrees C, and 37 degrees C anti-IgG enhanced, respectively. With an individualized PP/IVIg regimen based on donor-specific antibody titer, however, the relevant antibodies were adequately reduced and hyperacute rejection avoided. Subsequent antibody-mediated rejection, likely directed against a minor histocompatibility antigen, was diagnosed on postoperative day 7 and successfully treated. Neither ABO, or crossmatch incompatibility, or both in combination prohibit kidney transplantation.

ABO Blood-Group System↗

PubMed2003

p53 deficiency accelerates induction and progression of esophageal and forestomach tumors in zinc-deficient mice.

The p53 tumor suppressor protein plays a pivotal role in preventing uncontrolled cellular proliferation. By contrast, zinc deprivation enhances esophageal cell proliferation and the induction of esophageal tumors in rodents by N-nitrosomethylbenzylamine (NMBA). We investigated whether p53 deficiency rendered zinc-deficient (ZD) mice more susceptible to NMBA-induced esophageal/forestomach carcinogenesis. At 6-7 weeks of age, p53 null (-/-), heterozygous (+/-), and wild-type (+/+) mice were placed on ZD or zinc-sufficient (ZS) diets to form six experimental groups: ZD:p53-/-; ZD:p53+/-; ZD:p53+/+; ZS:p53-/-; ZS:p53+/-; and ZS:p53+/+. After 3 weeks, 15-23 mice in each group were treated once with NMBA (2 mg/kg body weight). Control animals were untreated. Zinc deficiency alone induced unrestrained cellular proliferation in the esophagus and forestomach of p53-/- mice. Forestomach tumors were first detected in a ZD:p53-/- mouse at 13 days. By 30 days, 100% (21 of 21) of ZD:p53-/- mice developed forestomach tumors and 38% showed esophageal tumors versus 42 and 0% in ZS:p53-/- mice (P < 0.004, esophagus; P < 0.001, forestomach). ZD:p53-/- mice showed an accelerated progression to malignancy, with 10% of esophageal tumors and 38% of forestomach tumors presenting as carcinomas. Nearly 20% of ZD:p53-/- mice developed esophageal Barrett's metaplasia, a lesion not previously seen in NMBA-induced neoplasia. ZD:p53+/- mice had significantly higher tumor incidence than ZS:p53+/- mice. The order of tumor incidence in forestomach was as follows: naught incidence in ZS:p53+/+ mice; ZD:p53-/- > ZD:p53+/- > ZS:p53-/- > ZD:p53+/+ >/= ZS:p53+/- > ZS:p53+/+. The rapid rate of tumor induction/progression in ZD:p53-/- mice was accompanied by an increase in the rate of cell proliferation and a decrease in apoptosis. cDNA array expression analysis of known genes identified a 5-fold up-regulation of cytokeratin 14 mRNA expression in ZD:p53-/- versus ZS:p53-/- forestomach, a result showing gene-modulating effects of zinc deficiency. Cytokeratin 14 is a biomarker in human esophageal carcinogenesis. Our findings provide in vivo evidence for the collaboration of a deficiency of both p53 and zinc in esophageal carcinogenesis and reveal molecular targets of this collaboration.

Animals↗

PubMed2003

Crescentic glomerulonephritis and subepidermal blisters with autoantibodies to alpha5 and alpha6 chains of type IV collagen.

We describe a novel autoimmune disease characterized by severe subepidermal bullous eruption and crescentic glomerulonephritis with autoantibodies directed against the noncollagenous domain of the alpha5 and alpha6 chains of type IV collagen. Biopsy of perilesional skin revealed a subepidermal blister with marked polymorphonuclear infiltrate with linear deposits of IgA and C3. Light microscopy of a kidney biopsy specimen revealed a crescentic glomerulonephritis, and immunofluorescence microscopy showed linear basement membrane staining for IgA (3+), C3 (1+), and IgG (1+). No electron-dense deposits were observed by transmission electron microscopy. The patient's autoantibodies reacted with normal human skin and kidney: IgA (3+) and IgG (1+) antibodies stained the basement membrane zones of skin, renal glomerulus, and some tubules. The identity of the target antigen was determined by immunochemical analyses of candidate antigens using the patient's autoantibodies. The patient's IgA and IgG autoantibodies reacted with a 185- to 190-kDa antigen from a human dermal extract that was distinguished from the other dermal or epidermal antigens, including the 145- to 290-kDa (type VII collagen) epidermolysis bullosa acquisita antigen, the 165- to 200-kDa alpha3 laminin mucous membrane cicatricial pemphigoid antigen, and the 230-kDa and the 180-kDa bullous pemphigoid antigens. Patient's IgA and IgG autoantibodies further reacted with the alpha5(IV) and weakly with the alpha6(IV) chains of type IV collagen by Western blot and ELISA. This report expands the repertoire of bullous skin disorders and provides an explanation for the association of anti-type IV collagen autoantibodies and glomerulonephritis with subepidermal blisters.

Aged↗

PubMed2002

Regulation of intracellular pH mediates Bax activation in HeLa cells treated with staurosporine or tumor necrosis factor-alpha.

Induction of apoptosis in HeLa cells with staurosporine produced a rise in the intracellular pH (pH(i)). Intracellular alkalinization was accompanied by translocation of Bax to the mitochondria, cytochrome c release, and cell death. The chloride channel inhibitor furosemide prevented intracellular alkalinization, Bax translocation, cytochrome c release, and cell death. Translocation of full-length Bid to the mitochondria was also prevented by furosemide. The cleavage product of Bid degradation (truncated Bid, tBid) was not detectable in the mitochondria. Its accumulation in the cytosol was prevented by furosemide. Apoptosis induced by tumor necrosis factor-alpha (TNF) lowered pH(i), an effect also accompanied by Bax translocation, cytochrome c release, and cell killing. Furosemide prevented all of these events. TNF induced a depletion of full-length Bid from the mitochondria and the cytosol but induced an accumulation of mitochondrial tBid. Furosemide only delayed full-length Bid depletion and tBid accumulation. The caspase 8 inhibitor IETD did not prevent the translocation of Bax. Although IETD did inhibit the cleavage of Bid and the accumulation of tBid, cell killing was reduced only slightly. It is concluded that with either staurosporine or TNF a furosemide-sensitive change in pH(i) is linked to Bax translocation, cytochrome c release, and cell killing. With TNF Bax translocation occurs as Bid is depleted and can be dissociated from the accumulation of tBid. With staurosporine a role for full-length Bid in Bax translocation cannot be excluded but is not necessary as evidenced by the data with TNF.

Apoptosis↗

PubMed2002

The course of etoposide-induced apoptosis from damage to DNA and p53 activation to mitochondrial release of cytochrome c.

Treatment of L929 fibroblasts by the topoisomerase II inhibitor etoposide killed 50% of the cells within 72 h. The cell killing was preceded by the release of cytochrome c from the mitochondria. Simultaneous treatment of the cells with wortmannin, cycloheximide, furosemide, cyclosporin A, or decylubiquinone prevented the release of cytochrome c and significantly reduced the loss of viability. Etoposide caused the phosphorylation of p53 within 6 h, an effect prevented by wortmannin, an inhibitor of DNA-dependent protein kinase (DNA-PK). The activation of p53 by etoposide resulted in the up-regulation of the pro-apoptotic protein Bax, a result that was prevented by the protein synthesis inhibitor cycloheximide. The increase in the content of Bax was followed by the translocation of this protein from the cytosol to the mitochondria, an event that was inhibited by furosemide, a chloride channel inhibitor. Stably transfected L929 fibroblasts that overexpress Akt were resistant to etoposide and did not translocate Bax to the mitochondria or release cytochrome c. Bax levels in these transfected cells were comparable with the wild-type cells. The release of cytochrome c upon translocation of Bax has been attributed to induction of the mitochondrial permeability transition (MPT). Cyclosporin A and decylubiquinone, inhibitors of MPT, prevented the release of cytochrome c without affecting Bax translocation. These data define a sequence of biochemical events that mediates the apoptosis induced by etoposide. This cascade proceeds by coupling DNA damage to p53 phosphorylation through the action of DNA-PK. The activation of p53 increases Bax synthesis. The translocation of Bax to the mitochondria induces the MPT, the event that releases cytochrome c and culminates in the death of the cells.

Androstadienes↗

PubMed2002

Cytochrome c release upon Fas receptor activation depends on translocation of full-length bid and the induction of the mitochondrial permeability transition.

In Jurkat cells Bid was cleaved upon activation of the Fas receptor with an anti-Fas antibody. The caspase-8 inhibitor benzyloxycarbonyl-Ile-Glu(OMe)-Thr-Asp(OMe)-CH(2)F (IETD) prevented the cleavage of Bid and the loss of viability. The nuclear enzyme poly(ADP-ribose)polymerase (PARP) was also cleaved upon the activation of caspases, and IETD similarly prevented PARP cleavage. The PARP inhibitor 3-aminobenzamide (3-AB) restored the cell killing in the presence of IETD, an effect that occurred without restoration of the cleavage of Bid or PARP. In the presence of 3-AB and IETD, translocation occurred of full-length Bid to the mitochondria. The induction of the mitochondrial permeability transition (MPT) was documented by the cyclosporin A (CyA) sensitivity of the release of cytochrome c, the release of malate dehydrogenase from the mitochondrial matrix, the loss of the mitochondrial membrane potential, and the pronounced swelling of these organelles, as assessed by electron microscopy. In addition to preventing all evidence of the MPT, CyA prevented the loss of cell viability, without effect on the cleavage of either Bid or PARP. The prevention of PARP cleavage by inhibition of caspase-3 resulted in a 10-fold activation of the enzyme and a resultant depletion of NAD and ATP. The PARP inhibitor 3-AB prevented the loss of NAD and ATP. Depletion of ATP by metabolic inhibitors similarly prevented the cell killing. It is concluded that the cleaving of PARP in Fas-mediated apoptosis allowed expression of an energy-dependent cell death program that included the translocation of full-length Bid to the mitochondria with induction of the MPT.

Actins↗