Progressive multifocal fibrosing neuropathy: description of a novel disease

Entrapment peripheral neuropathies are clinically characterized by sensory impairment and motor deficits. They are usually caused by mechanical injuries, but they are also a frequent manifestation of metabolic diseases, toxic agent exposure, or systemic fibrotic disorders. Here we describe the clinical, radiological, and histopathological features of a novel progressive fibrotic disorder characterized by progressive multifocal fibrosing neuropathy. We identified two patients who presented with severe and progressive peripheral neuropathic symptoms sequentially affecting multiple sites. These patients presented with severe and progressive multifocal, sequentially additive peripheral neuropathic symptoms. Extensive nerve conduction and radiological studies showed the sequential development of multifocal motor and sensory peripheral neuropathy in the absence of any exposure to known infectious, inflammatory, or fibrotic triggers and the lack of family history of compression neuropathies. Extensive clinical and laboratory test evaluation failed to support the diagnosis of any primary inflammatory or genetic peripheral neuropathy and there was no evidence of any systemic fibrosing disorder including Systemic Sclerosis, lacking cutaneous fibrotic changes and cardiopulmonary abnormalities. The clinical course was progressive with sequential development of motor and sensory deficits of upper and lower extremities displaying proximal predominance. Histopathological study of tissues obtained during nerve release surgeries showed severe perineural fibrosis with marked accumulation of thick collagen bundles encroaching the peripheral nerves. There was no evidence of vasculitic, inflammatory, or vascular fibroproliferative lesions. We suggest that the clinical findings described here represent a previously undescribed fibrotic disorder affecting peripheral nerves, and we propose the descriptive term "Progressive Multifocal Fibrosing Neuropathy" to refer to this novel disorder. Despite the inherent limitations of this early description, we hope this is would contribute to the identification of additional cases.

Thrombotic Microangiopathy, an Unusual Form of Monoclonal Gammopathy of Renal Significance: Report of 3 Cases and Literature Review

Monoclonal gammopathies result from neoplastic clones of the B-cell lineage and may cause kidney disease by various mechanisms. When the underlying clone does not meet criteria for a malignancy requiring treatment, the paraprotein is called a monoclonal gammopathy of renal significance (MGRS). One rarely reported kidney lesion associated with benign paraproteins is thrombotic microangiopathy (TMA), provisionally considered as a combination signifying MGRS. Such cases may lack systemic features of TMA, such as a microangiopathic hemolytic anemia, and the disease may be kidney limited. There is no direct deposition of the paraprotein in the kidney, and the presumed mechanism is disordered complement regulation. We report three cases of kidney limited TMA associated with benign paraproteins that had no other detectable cause for the TMA, representing cases of MGRS. Two of the cases are receiving clone directed therapy, and none are receiving eculizumab. We discuss in detail the pathophysiological basis for this possible association. Our approach to therapy involves first ruling out other causes of TMA as well as an underlying B-cell malignancy that would necessitate direct treatment. Otherwise, clone directed therapy should be considered. If refractory to such therapy or the disease is severe and multisystemic, C5 inhibition (eculizumab or ravulizumab) may be indicated as well.

Noninvasive Assessment of the Alloimmune Response in Kidney Transplantation

Transplantation remains the optimal mode of kidney replacement therapy, but unfortunately long-term graft survival after 1 year remains suboptimal. The main mechanism of chronic allograft injury is alloimmune, and current clinical monitoring of kidney transplants includes measuring serum creatinine, proteinuria, and immunosuppressive drug levels. The most important biomarker routinely monitored is human leukocyte antigen (HLA) donor-specific antibodies (DSAs) with the frequency based on underlying immunologic risk. HLA-DSA should be measured if there is graft dysfunction, immunosuppression minimization, or nonadherence. Antibody strength is semiquantitatively estimated as mean fluorescence intensity, with titration studies for equivocal cases and for following response to treatment. Determination of in vitro C1q or C3d positivity or HLA-DSA IgG subclass analysis remains of uncertain significance, but we do not recommend these for routine use. Current evidence does not support routine monitoring of non-HLA antibodies except anti-angiotensin II type 1 receptor antibodies when the phenotype is appropriate. The monitoring of both donor-derived cell-free DNA in blood or gene expression profiling of serum and/or urine may detect subclinical rejection, although mainly as a supplement and not as a replacement for biopsy. The optimal frequency and cost-effectiveness of using these noninvasive assays remain to be determined. We review the available literature and make recommendations.

Abrogation of esophageal carcinoma development in miR-31 knockout rats

MicroRNA-31 (miR-31) is overexpressed in esophageal squamous cell carcinoma (ESCC), a deadly disease associated with dietary Zn deficiency and inflammation. In a Zn deficiency-promoted rat ESCC model with miR-31 up-regulation, cancer-associated inflammation, and a high ESCC burden following N-nitrosomethylbenzylamine (NMBA) exposure, systemic antimiR-31 delivery reduced ESCC incidence from 85 to 45% (P = 0.038) and miR-31 gene knockout abrogated development of ESCC (P = 1 × 10-6). Transcriptomics, genome sequencing, and metabolomics analyses in these Zn-deficient rats revealed the molecular basis of ESCC abrogation by miR-31 knockout. Our identification of EGLN3, a known negative regulator of nuclear factor κB (NF-κB), as a direct target of miR-31 establishes a functional link between oncomiR-31, tumor suppressor target EGLN3, and up-regulated NF-κB-controlled inflammation signaling. Interaction among oncogenic miR-31, EGLN3 down-regulation, and inflammation was also documented in human ESCCs. miR-31 deletion resulted in suppression of miR-31-associated EGLN3/NF-κB-controlled inflammatory pathways. ESCC-free, Zn-deficient miR-31-/- rat esophagus displayed no genome instability and limited metabolic activity changes vs. the pronounced mutational burden and ESCC-associated metabolic changes of Zn-deficient wild-type rats. These results provide conclusive evidence that miR-31 expression is necessary for ESCC development.

Human-like hyperplastic prostate with low ZIP1 induced solely by Zn deficiency in rats

Prostate cancer is a leading cause of cancer death in men over 50 years of age, and there is a characteristic marked decrease in Zn content in the malignant prostate cells. The cause and consequences of this loss have thus far been unknown. We found that in middle-aged rats a Zn-deficient diet reduces prostatic Zn levels (P = 0.025), increases cellular proliferation, and induces an inflammatory phenotype with COX-2 overexpression. This hyperplastic/inflammatory prostate has a human prostate cancer-like microRNA profile, with up-regulation of the Zn-homeostasis-regulating miR-183-96-182 cluster (fold change = 1.41-2.38; P = 0.029-0.0003) and down-regulation of the Zn importer ZIP1 (target of miR-182), leading to a reduction of prostatic Zn. This inverse relationship between miR-182 and ZIP1 also occurs in human prostate cancer tissue, which is known for Zn loss. The discovery that the Zn-depleted middle-aged rat prostate has a metabolic phenotype resembling that of human prostate cancer, with a 10-fold down-regulation of citric acid (P = 0.0003), links citrate reduction directly to prostatic Zn loss, providing the underlying mechanism linking dietary Zn deficiency with miR-183-96-182 overexpression, ZIP1 down-regulation, prostatic Zn loss, and the resultant citrate down-regulation, changes mimicking features of human prostate cancer. Thus, dietary Zn deficiency during rat middle age produces changes that mimic those of human prostate carcinoma and may increase the risk for prostate cancer, supporting the need for assessment of Zn supplementation in its prevention.

MicroRNA dysregulation and esophageal cancer development depend on the extent of zinc dietary deficiency

Zinc deficiency (ZD) increases the risk of esophageal squamous cell carcinoma (ESCC), and marginal ZD is prevalent in humans. In rats, marked-ZD (3 mg Zn/kg diet) induces a proliferative esophagus with a 5-microRNA signature (miR-31, -223, -21, -146b, -146a) and promotes ESCC. Here we report that moderate and mild-ZD (6 and 12 mg Zn/kg diet) also induced esophageal hyperplasia, albeit less pronounced than induced by marked-ZD, with a 2-microRNA signature (miR-31, -146a). On exposure to an environmental carcinogen, ∼16% of moderate/mild-ZD rats developed ESCC, a cancer incidence significantly greater than for Zn-sufficient rats (0%) (P ≤ 0.05), but lower than marked-ZD rats (68%) (P < 0.001). Importantly, the high ESCC, marked-ZD esophagus had a 15-microRNA signature, resembling the human ESCC miRNAome, with miR-223, miR-21, and miR-31 as the top-up-regulated species. This signature discriminated it from the low ESCC, moderate/mild-ZD esophagus, with a 2-microRNA signature (miR-31, miR-223). Additionally, Fbxw7, Pdcd4, and Stk40 (tumor-suppressor targets of miR-223, -21, and -31) were downregulated in marked-ZD cohort. Bioinformatics analysis predicted functional relationships of the 3 tumor-suppressors with other cancer-related genes. Thus, microRNA dysregulation and ESCC progression depend on the extent of dietary Zn deficiency. Our findings suggest that even moderate ZD may promote esophageal cancer and dietary Zn has preventive properties against ESCC. Additionally, the deficiency-associated miR-223, miR-21, and miR-31 may be useful therapeutic targets in ESCC.

Integration of metabolomics, transcriptomics, and microRNA expression profiling reveals a miR-143-HK2-glucose network underlying zinc-deficiency-associated esophageal neoplasia

Esophageal squamous cell carcinoma (ESCC) in humans is a deadly disease associated with dietary zinc (Zn)-deficiency. In the rat esophagus, Zn-deficiency induces cell proliferation, alters mRNA and microRNA gene expression, and promotes ESCC. We investigated whether Zn-deficiency alters cell metabolism by evaluating metabolomic profiles of esophageal epithelia from Zn-deficient and replenished rats vs sufficient rats, using untargeted gas chromatography time-of-flight mass spectrometry (n = 8/group). The Zn-deficient proliferative esophagus exhibits a distinct metabolic profile with glucose down 153-fold and lactic acid up 1.7-fold (P < 0.0001), indicating aerobic glycolysis (the “Warburg effect”), a hallmark of cancer cells. Zn-replenishment rapidly increases glucose content, restores deregulated metabolites to control levels, and reverses the hyperplastic phenotype. Integration of metabolomics and our reported transcriptomic data for this tissue unveils a link between glucose down-regulation and overexpression of HK2, an enzyme that catalyzes the first step of glycolysis and is overexpressed in cancer cells. Searching our published microRNA profile, we find that the tumor-suppressor miR-143, a negative regulator of HK2, is down-regulated in Zn-deficient esophagus. Using in situ hybridization and immunohistochemical analysis, the inverse correlation between miR-143 down-regulation and HK2 overexpression is documented in hyperplastic Zn-deficient esophagus, archived ESCC-bearing Zn-deficient esophagus, and human ESCC tissues. Thus, to sustain uncontrolled cell proliferation, Zn-deficiency reprograms glucose metabolism by modulating expression of miR-143 and its target HK2. Our work provides new insight into critical roles of Zn in ESCC development and prevention.

The Nephrotoxicity of Vancomycin

Vancomycin use is often associated with nephrotoxicity. It remains uncertain, however, to what extent vancomycin is directly responsible, as numerous potential risk factors for acute kidney injury frequently coexist. Herein, we critically examine available data in adult patients pertinent to this question. We review the pharmacokinetics/pharmacodynamics of vancomycin metabolism. Efficacy and safety data are discussed. The pathophysiology of vancomycin nephrotoxicity is considered. Risk factors for nephrotoxicity are enumerated, including the potential synergistic nephrotoxicity of vancomycin and piperacillin‐tazobactam. Suggestions for clinical practice and future research are given.

Rapidly Fatal Hemophagocytic Lymphohistiocytosis Developing Within Six Days Following Deceased-Donor Renal Transplantation: Case Report

Hemophagocytic lymphohistiocytosis (HLH) is an often fatal hyperinflammatory syndrome that may complicate malignancy, infection, rheumatic disease, or immunosuppression. HLH after kidney transplantation is most often triggered by infection, usually Herpes viruses such as cytomegalovirus and Epstein-Barr virus (EBV). It usually occurs early after transplantation. We present a case of HLH triggered by reactivation of EBV that pursued a rapidly fatal course within 6 days of receiving a deceased-donor kidney transplant. This case serves to remind transplant clinicians to consider HLH when cytopenias and hyperinflammation are atypical for the usual post-transplantation course. We discuss pitfalls in diagnosis and suggestions for treatment in this setting.

Correlation of acute tubular injury in reperfusion biopsy with renal transplant outcomes

Acute tubular injury (ATI) is common at reperfusion, but its relationship to graft outcomes is unclear. Prior studies lack standardization of morphological assessments and included elements of acute and chronic tubular injury. This study aimed to evaluate the impact of ATI on graft outcomes. Reperfusion biopsies from 2004 to 2009 were retrospectively reviewed. ATI was assessed by a new standardized scoring system. We also assessed chronic injury (CI) by the Banff criteria. Outcomes evaluated included glomerular filtration rate (GFR) at 1 and 5 years and delayed graft function (DGF), acute rejection (AR), graft and patient survival. ATI did not correlate with DGF, AR, graft or overall survival. Mild-moderate ATI was not predictive of GFR post-transplant. Moderate-severe CI was associated with lower GFR at 5 years with a mean difference of -7.14 mL/min/1.73 m(2) (P=.04) and overall survival (HR 2.44, P=.01). Other predictors of graft function included donor age, DGF, and AR. Histologic criteria of ATI at implantation in the absence of donor demographics or clinical information do not provide sufficient predictability in outcomes after transplantation. On the other hand, histologic assessment of CI correlates with GFR and overall survival.

Endothelial Cells Expressing Endothelial and Mesenchymal Cell Gene Products in Lung Tissue From Patients With Systemic Sclerosis-Associated Interstitial Lung Disease

OBJECTIVE

To examine whether lung endothelial cells (ECs) from patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD) express mesenchymal cell-specific proteins and gene transcripts, indicative of the occurrence of endothelial-to-mesenchymal phenotypic transition (EndoMT).

METHODS

Lung tissue from 6 patients with SSc-associated pulmonary fibrosis was examined by histopathology and immunohistochemistry. Confocal laser microscopy was utilized to assess the simultaneous expression of EC and myofibroblast molecular markers. CD31+CD102+ ECs were isolated from the lung tissue of 2 patients with SSc-associated ILD and 2 normal control subjects, and the expression of EC and mesenchymal cell markers and other relevant genes was analyzed by quantitative polymerase chain reaction, immunofluorescence microscopy, and Western blotting.

RESULTS

Immunohistochemical staining revealed cells expressing the EC-specific marker CD31 in the subendothelial, perivascular, and parenchymal regions of the lungs from all SSc patients. Confocal microscopy identified cells displaying simultaneous expression of von Willebrand factor and α-smooth muscle actin in small and medium-sized arterioles in the SSc lung tissue but not in normal control lungs. CD31+CD102+ ECs isolated from SSc lungs expressed high levels of mesenchymal cell-specific genes (type I collagen, type III collagen, and fibronectin), EC-specific genes (type IV collagen and VE-cadherin), profibrotic genes (transforming growth factor β1 and connective tissue growth factor), and genes encoding EndoMT-related transcription factors (TWIST1 and SNAI2).

CONCLUSION

Cells coexpressing EC- and mesenchymal cell-specific molecules are present in the lungs of patients with SSc-associated ILD. CD31+CD102+ ECs isolated from SSc lungs simultaneously expressed mesenchymal cell- and EC-specific transcripts and proteins. Collectively, these observations demonstrate the occurrence of EndoMT in the lungs of patients with SSc-associated ILD.

Repression of Esophageal Neoplasia and Inflammatory Signaling by Anti-miR-31 Delivery In Vivo

BACKGROUND

Overexpression of microRNA-31 (miR-31) is implicated in the pathogenesis of esophageal squamous cell carcinoma (ESCC), a deadly disease associated with dietary zinc deficiency. Using a rat model that recapitulates features of human ESCC, the mechanism whereby Zn regulates miR-31 expression to promote ESCC is examined.

METHODS

To inhibit in vivo esophageal miR-31 overexpression in Zn-deficient rats (n = 12-20 per group), locked nucleic acid-modified anti-miR-31 oligonucleotides were administered over five weeks. miR-31 expression was determined by northern blotting, quantitative polymerase chain reaction, and in situ hybridization. Physiological miR-31 targets were identified by microarray analysis and verified by luciferase reporter assay. Cellular proliferation, apoptosis, and expression of inflammation genes were determined by immunoblotting, caspase assays, and immunohistochemistry. The miR-31 promoter in Zn-deficient esophagus was identified by ChIP-seq using an antibody for histone mark H3K4me3. Data were analyzed with t test and analysis of variance. All statistical tests were two-sided.

RESULTS

In vivo, anti-miR-31 reduced miR-31 overexpression (P = .002) and suppressed the esophageal preneoplasia in Zn-deficient rats. At the same time, the miR-31 target Stk40 was derepressed, thereby inhibiting the STK40-NF-κΒ-controlled inflammatory pathway, with resultant decreased cellular proliferation and activated apoptosis (caspase 3/7 activities, fold change = 10.7, P = .005). This same connection between miR-31 overexpression and STK40/NF-κΒ expression was also documented in human ESCC cell lines. In Zn-deficient esophagus, the miR-31 promoter region and NF-κΒ binding site were activated. Zn replenishment restored the regulation of this genomic region and a normal esophageal phenotype.

CONCLUSIONS

The data define the in vivo signaling pathway underlying interaction of Zn deficiency and miR-31 overexpression in esophageal neoplasia and provide a mechanistic rationale for miR-31 as a therapeutic target for ESCC.

Humoral Immune Response and Allograft Function in Kidney Transplantation

HLA antibodies can damage a kidney transplant. In January 2013, consensus guidelines from The Transplantation Society were published regarding technical aspects of HLA antibody determination, as well as their potential significance in the pre- and posttransplantation periods. During the past 2 years, new studies have been reported, but controversies remain. In this article, these new data related to HLA antibodies in kidney transplantation are reviewed and compared to relevant prior research. Pretransplantation sensitization issues are discussed, including the new more sensitive assays (flow cytometry and solid-phase immunoassays such as Luminex single-antigen bead assays). A positive complement-dependent cytotoxicity crossmatch remains an absolute contraindication to transplantation, although a positive flow cytometry crossmatch is only a relative contraindication. Positivity only by solid-phase assays increases the risk for acute rejection and transplant loss, but acceptable cutoffs are not defined. The sensitizing effect of red blood cell transfusions is substantiated. Following allograft failure, continued immunosuppression decreases the risk of sensitization, whereas overall, the effect of nephrectomy remains uncertain. Regarding the posttransplantation period, new data are available concerning the timing and significance of donor-specific antibodies (DSA). Whereas some centers report DSA appearance after years, others detect DSA within months. The prominence of class II DSA, especially DQ, in the posttransplantation period is noted. The relevance of non-HLA antibodies is discussed, including anti-endothelial cell antibodies, major histocompatibility complex class I chain-related protein A antibodies, and angiotensin II type 1 receptor autoantibodies.

Posttransplantation normoglycemic diabetic nephropathy: the role of the allograft insulin resistance--a case report

BACKGROUND

The pathogenesis of diabetic nephropathy is incompletely understood. Although the role of hyperglycemia is well-established, the participation of insulin resistance is increasingly appreciated. Podocytes are insulin responsive cells and require normal insulin signaling for sustained viability.

CASE REPORT

We have presented a renal transplant recipient with lupus nephritis who received a deceased donor kidney from a patient with diabetes mellitus (DM). The kidney functioned well initially. Within 2 years, however, nephrotic range proteinuria developed, and a biopsy revealed diabetic nephropathy that had clearly evolved in comparison with the implantation biopsy. The recipient was repeatedly normoglycemic with normal glycated hemoglobin and glucose tolerance, and she was found to be quite insulin sensitive on the basis of a low homeostasis model assessment of insulin resistance.

CONCLUSIONS

We argue that the nephropathy developed in the allograft owing to impaired insulin signaling from intrinsic donor-derived insulin resistance that was exacerbated by low insulin levels in the insulin-sensitive recipient. This case has implications for the most appropriate utilization of kidneys from donors with DM.

Normoglycemic diabetic nephropathy: the role of insulin resistance

The pathophysiology of diabetic nephropathy (DN) is complex and incompletely understood. Whereas hyperglycemia is clearly important, the role of insulin resistance (IR) is increasingly recognized. We present the case of a normotensive non-smoking obese woman with nephrotic syndrome who was found to have DN by biopsy. All measures of glucose metabolism, including fasting glucose, glycosylated hemoglobin, and oral glucose tolerance testing, were repeatedly normal with little exception. IR was documented, however, based on the presence of the metabolic syndrome and an elevated homeostasis model assessment of IR. We posit that this IR is central to the pathogenesis of our patient's lesion, and this may explain other cases of DN with normoglycemia. The literature supporting this concept is discussed.

The specificity of acute and chronic microvascular alterations in renal allografts

The diagnosis of an antibody-mediated rejection (AMR) is made when there is evident histologic injury in the presence of detectable donor-specific alloantibodies (DSA) and diffuse peritubular capillary C4d staining (C4d-pos). In the presence of only detectable DSA or C4d-pos, the tissue injury is currently considered "presumptive" for antibody causation. In acute antibody-mediated rejection (AAMR), diagnostic morphologic features include microvascular inflammation (MVI), specifically glomerulitis and peritubular capillaritis. In the case of chronic active AMR (CAAMR), these inflammatory lesions have progressed to chronic microvascular injury, transplant glomerulopathy (TG) and peritubular capillary basement membrane multilayering (PTCBMML). Either TG or PTCBMML is sufficient morphological evidence for a diagnosis of CAAMR. Unfortunately, these lesions are not specific. MVI, TG, and PTCBMML are found in the setting of cell-mediated immunity, as well as in association with non-alloimmune mechanisms. The available treatments for AMR and CMR are different, and it is important to ascertain the dominant mechanism when approaching an individual patient. At present, no gold standard exists to establish the specific pathogenesis in the more ambiguous cases. We detail here the differential diagnosis of MVI, TG, and PTCBMML.

Secondary membranous nephropathy associated with guillain-barré syndrome

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome (NS) in adults. It may be primary, usually mediated by IgG4 anti-phospholipase A2 autoantibodies or secondary to various other conditions. Guillain- Barré syndrome (GBS) has been associated with MN, but a cause and effect relation has not been proven. We present a case of concurrent development of GBS and severe NS, with renal biopsy demonstrating MN. IgG4 stain was negative, indicating that most likely, the MN was secondary and probably caused by the underlying GBS.

Abstract LB-241: Silencing of microRNA-31 prevents esophageal neoplasia in zinc deficient rats

Dietary zinc deficiency (ZD) is implicated in the pathogenesis of human esophageal squamous cell carcinoma (ESCC). microRNA-31 (miR-31) is overexpressed in human ESCC. In the rat a ZD diet promotes esophageal carcinogenesis by inducing cellular proliferation and changes in the expression of microRNA and mRNA, including overexpression of miR-31 and cancer-related proinflammation genes. Here we report that treatment of ZD rats with locked nucleic acid (LNA)-modified inhibitor of miR-31 (LNA-antimiR) prevents the development of a precancerous esophageal phenotype. Weanling rats were fed ZD or zinc-sufficient (ZS) diet for 5 weeks. Simultaneously, ZD rats were administered intravenously (twice a week) LNA-antimiR, LNA-scramble miR-31 or the vehicle saline. ZS rats received saline. Compared to ZS rats, LNA-scramble miR-31-treated or saline-treated ZD rats overexpressed miR-31 and displayed a highly proliferative and inflammatory esophageal phenotype. Treatment of ZD rats with LNA-antimiR reduced miR-31 expression in esophageal epithelia and circulating blood by ~60% and reversed the ZD-induced esophageal pathology, as evidenced by a thinned esophageal epithelium with reduced cell proliferation by PCNA immunohistochemistry and increased apoptosis by caspase-3/7 activity. Transcriptome analyses of esophageal epithelia demonstrated derepression of target mRNAs with miR-31 seed sites. In particular, Stk40 (a negative regulator of NF-κ? signaling) was demonstrated to be a bona fide miR-31 target. Using in situ hybridization and immunohistochemistry, miR-31 overexpression in ZD esophageal sections correlated with downregulation of STK40 protein, as well as with upregulation of an NF-κ? p65 - RAGE-S100A9 inflammatory pathway that in turn, was normalized by miR-31 silencing. Thus, silencing miR-31 prevents esophageal neoplasia. Overexpression of miR-31 promotes ESCC initiation by enhancing inflammation via STK40 - NF-κ? signaling. The data indicate that miR-31 may be a promising therapeutic target for improved ESCC diagnosis and prevention. Funding: National Institutes of Health grants U01 CA152758 to CMC and R01CA118560 & R21CA152505 to LYYF.

Citation Format: Cristian Taccioli, Hongping Chen, Michela Garofalo, Yubao Jiang, Gianpiero Di Leva, Hansjuerg Alder, Justin Middleton, Karl J. Smalley, Arianna Bottoni, Stefan Costinean, John L. Farber, Carlo M. Croce, Louise Y Y Fong. Silencing of microRNA-31 prevents esophageal neoplasia in zinc deficient rats. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-241. doi:10.1158/1538-7445.AM2013-LB-241

CDK4/6 inhibition antagonizes the cytotoxic response to anthracycline therapy

Triple-negative breast cancer (TNBC) is an aggressive disease that lacks established markers to direct therapeutic intervention. Thus, these tumors are routinely treated with cytotoxic chemotherapies (e.g., anthracyclines), which can cause severe side effects that impact quality of life. Recent studies indicate that the retinoblastoma tumor suppressor (RB) pathway is an important determinant in TNBC disease progression and therapeutic outcome. Furthermore, new therapeutic agents have been developed that specifically target the RB pathway, potentially positioning RB as a novel molecular marker for directing treatment. The current study evaluates the efficacy of pharmacological CDK4/6 inhibition in combination with the widely used genotoxic agent doxorubicin in the treatment of TNBC. Results demonstrate that in RB-proficient TNBC models, pharmacological CDK4/6 inhibition yields a cooperative cytostatic effect with doxorubicin but ultimately protects RB-proficient cells from doxorubicin-mediated cytotoxicity. In contrast, CDK4/6 inhibition does not alter the therapeutic response of RB-deficient TNBC cells to doxorubicin-mediated cytotoxicity, indicating that the effects of doxorubicin are indeed dependent on RB-mediated cell cycle control. Finally, the ability of CDK4/6 inhibition to protect TNBC cells from doxorubicin-mediated cytotoxicity resulted in recurrent populations of cells specifically in RB-proficient cell models, indicating that CDK4/6 inhibition can preserve cell viability in the presence of genotoxic agents. Combined, these studies suggest that while targeting the RB pathway represents a novel means of treatment in aggressive diseases such as TNBC, there should be a certain degree of caution when considering combination regimens of CDK4/6 inhibitors with genotoxic compounds that rely heavily on cell proliferation for their cytotoxic effects.

Dysregulation of miR-31 and miR-21 induced by zinc deficiency promotes esophageal cancer

Zinc deficiency (ZD) increases the risk of esophageal squamous cell carcinoma (ESCC). In a rat model, chronic ZD induces an inflammatory gene signature that fuels ESCC development. microRNAs regulate gene expression and are aberrantly expressed in cancers. Here we investigated whether chronic ZD (23 weeks) also induces a protumorigenic microRNA signature. Using the nanoString technology, we evaluated microRNA profiles in ZD esophagus and six additional tissues (skin, lung, pancreas, liver, prostate and peripheral blood mononuclear cells [PBMC]). ZD caused overexpression of inflammation genes and altered microRNA expression across all tissues analyzed, predictive of disease development. Importantly, the inflammatory ZD esophagus had a distinct microRNA signature resembling human ESCC or tongue SCC miRNAomes with miR-31 and miR-21 as the top-up-regulated species. Circulating miR-31 was also the top-up-regulated species in PBMCs. In ZD esophagus and tongue, oncogenic miR-31 and miR-21 overexpression was accompanied by down-regulation of their respective tumor-suppressor targets PPP2R2A and PDCD4. Importantly, esophageal miR-31 and miR-21 levels were directly associated with the appearance of ESCC in ZD rats, as compared with their cancer-free Zn-sufficient or Zn-replenished counterparts. In situ hybridization analysis in rat and human tongue SCCs localized miR-31 to tumor cells and miR-21 to stromal cells. In regressing tongue SCCs from Zn-supplemented rats, miR-31 and miR-21 expression was concomitantly reduced, establishing their responsiveness to Zn therapy. A search for putative microRNA targets revealed a bias toward genes in inflammatory pathways. Our finding that ZD causes miR-31 and miR-21 dysregulation associated with inflammation provides insight into mechanisms whereby ZD promotes ESCC.

Peritransplant kidney biopsies: comparison of pathologic interpretations and practice patterns of organ procurement organizations

The preimplantation kidney biopsy affects utilization by diagnosing glomerulosclerosis, interstitial fibrosis (IF), arteriosclerosis, and arteriolar hyalinosis. Organ procurement organizations (OPOs) determine whether a donor warrants this biopsy and the donor hospital pathologists (DHPs) report on an OPO-specific pathology interpretation form. Biopsy slides from 40 deceased donor kidneys transplanted at our institution were used to compare interpretations between our transplant pathologist and the DHPs. Thirty-three of these kidneys also had post-perfusion biopsies (PPB). All 58 OPOs were queried for criteria used to request a preimplantation biopsy, and their pathology interpretation forms were also analyzed. The transplant and DHPs had substantial agreement for percent glomerulosclerosis with 75% of biopsies being interpreted within five percentage points. Concordance for IF was poor. The DHP rarely reported arterial pathology. Seventy percent of preimplantation and PPB were read similarly for glomerulosclerosis; concordance for other lesions was weaker. There were no cues for arterial disease on our OPO's pathology interpretation form. Criteria for obtaining a preimplantation biopsy lacked uniformity for the 21 OPOs with a self-generated policy. The pathology interpretation forms varied widely among the OPOs. Current OPO practices with regard to the preimplantation biopsy should be improved.

Sirolimus-induced pneumonitis complicated by pentamidine-induced phospholipidosis in a renal transplant recipient: a case report

The proliferation signal inhibitors (PSIs)-sirolimus, everolimus, and temsirolimus-have been associated with a noninfectious pneumonitis characterized by lymphocytic alveolitis and bronciolitis obliterans with organizing pneumonia (BOOP). This condition usually occurs within the first year. Herein we presented a case of a deceased donor renal transplant with interstitial pneumonitis developing 6 years after a switch from tacrolimus to sirolimus due to chronic graft dysfunction. After the addition of intravenous pentamidine due to the suspicion of Pneumocystis pneumonia, there was marked clinical deterioration requiring intubation. Open lung biopsy revealed sirolimus-induced pulmonary toxicity (BOOP) with the additional finding of a drug-induced phospholipidosis (DIPL) that we ascribe to pentamidine treatment. After cessation of both drugs and application of corticosteroid therapy, there was only partial improvement. Eight months later the residual interstitial fibrosis demands supplemental home oxygen. We review the literature on PSI-induced pneumonitis and discuss the pathophysiology of a potential interaction with pentamidine. We caution against its use in the setting of PSI-induced pneumonitis. It is currently unknown whether these concerns also apply to prescription of other more commonly used medications associated with DIPL, eg, amiodarone and aminoglycosides.

Segmental arterial mediolysis: report of 2 cases and review of the literature

Segmental arterial mediolysis (SAM) is an idiopathic noninflammatory vasculopathy involving small to medium arteries, usually in the abdomen, although arteries in the cerebral and coronary circulations also may be affected. Some cases present as abdominal apoplexy due to aneurysmal rupture, but ischemia and infarction also occur. Not uncommonly, SAM may be misdiagnosed as a systemic necrotizing vasculitis. We present 2 patients with bilateral renal infarctions, cerebral arterial dissections, and visceral artery microaneurysms. Both were diagnosed initially as polyarteritis nodosa. The diagnosis was changed to SAM, in one case based on clinical and radiologic features, and in the other, on an open wedge kidney biopsy. We discuss the differential diagnosis and review the literature on SAM.

Zinc supplementation suppresses 4-nitroquinoline 1-oxide-induced rat oral carcinogenesis

Dietary zinc (Zn) deficiency is implicated in the pathogenesis of human oral-esophageal cancers. In rats, Zn deficiency causes increased cell proliferation and cyclooxygenase-2 (COX-2) overexpression and enhances oral carcinogenesis by 4-nitroquinoline 1-oxide (NQO). Zn replenishment reverses all these effects. We questioned whether Zn has antitumor efficacy in a Zn-sufficient animal by investigating in Zn-sufficient rats (i) the efficacy of Zn supplementation on the progression of tongue squamous cell carcinogenesis induced by drinking water exposure to high (20-30 p.p.m.) and low (10 p.p.m.) doses of NQO and (ii) the modulating effects of Zn supplementation on biomarker expression in tongue lesions by immunohistochemistry. In rats exposed to high doses of NQO, Zn supplementation significantly reduced the incidence of papillomas from 100 to 64.7% (P=0.018) and invasive carcinomas from 93.8 to 52.9% (P=0.017). In rats exposed to low doses of NQO, where only minimally invasive carcinomas developed, Zn supplementation significantly reduced tumor multiplicity, incidence of tumors (1-2 mm), hyperplasia, dysplasia, papillomas and progression to carcinoma. Immunohistochemical analysis of carcinomas showed that Zn supplementation caused a shift to a less proliferative/aggressive cancer phenotype by reducing cell proliferation, stimulating apoptosis and decreasing expression of the key tumor markers cyclin D1, p53 and COX-2. Additionally, Zn supplementation significantly reduced cell proliferation in non-lesional tongue squamous epithelia, thereby suppressing tumor development. Together, the results demonstrate that Zn supplementation has chemopreventive efficacy against oral carcinogenesis in nutritionally complete animals. Our data suggest that Zn supplementation may be efficacious in the chemoprevention of human oral cancer.

Abstract B64: Zinc supplementation has antitumor effects in 4-nitroquinoline 1-oxide-induced rat oral carcinogenesis

Zinc (Zn)-deficiency promotes esophageal/tongue tumorigenesis in rats by causing cell proliferation and changes in gene expression and Zn-replenishment inhibits tumorigenesis by attenuating cell proliferation and abnormal gene expression. Whether Zn has antitumor activities in a Zn-sufficient animal, however, is unknown. Here we examined the effects of Zn supplementation on tongue carcinogenesis in Zn-sufficient male Sprague-Dawley rats formerly exposed for 8 weeks to the carcinogen 4-nitroquinoline 1-oxide (NQO) at 10 and 20-30 ppm dose levels. Immediately after the cessation of NQO exposure, Zn gluconate (0, 20 ppm) was administered in the drinking water and continued for 10-13 weeks. At both NQO levels, Zn-supplemented rats had fewer tongue lesions than respective controls (10 ppm NQO: 5.2 ± 0.4 vs 8.6 ± 0.7, P&lt;0.001; 20-30 ppm NQO: 10.6 ± 1.1 vs. 18.4 ± 1.2, P&lt;0.01). Additionally, Zn-supplementation reduced the incidence of early tongue squamous cell carcinomas (SCC) from 40% [10/25] to 11.5% [3/26] (P=0.027) and that of invasive SCC from 93.8% [15/16] to 47.1% [8/17] (P=0.007) in rats exposed to 10 and 20-30 ppm NQO, respectively. The cell proliferative activity, as measured by quantitative proliferating cell nuclear antigen (PCNA)-immunohistochemistry, was significantly lower in the nontumorous tongue epithelia from Zn-supplemented rats than untreated controls (P&lt;0.001). Compared with invasive tongue SCC from controls, Zn treatment led to less proliferative tongue SCCs with reduced immunostaining of cyclin D1, COX-2, NF-kB p65, and p53 proteins but increased apoptotic index. Thus, our finding that Zn inhibits tongue cancer progression in Zn-sufficient as in Zn-deficient animals should lead to prevention and therapeutic possibilities for oral cancer. Supported by National Institute of Health Grants R01CA118560 (LYYF) and R01 CA115965 (CMC).

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B64.

Zinc deficiency activates S100A8 inflammation in the absence of COX-2 and promotes murine oral-esophageal tumor progression

Zinc (Zn)-deficiency (ZD) is implicated in the pathogenesis of human oral-esophageal cancers. Previously, we showed that in ZD mice genetic deletion of cyclooxygenase-2 (Cox-2) enhances N-nitrosomethylbenzylamine-induced forestomach carcinogenesis. By contrast, Cox-2 deletion offers protection in Zn-sufficient (ZS) mice. We hypothesize that ZD activates pathways insensitive to COX-2 inhibition, thereby promoting carcinogenesis. This hypothesis is tested in a Cox-2^−/− mouse tongue cancer model that mimics pharmacologic blockade of COX-2 by firstly examining transcriptome profiles of forestomach mucosa from Cox-2^−/− and wild-type mice on a ZD vs. ZS diet, and secondly investigating the roles of identified markers in mouse forestomach/tongue preneoplasia and carcinomas. In Cox-2^−/− mice exposed to the tongue carcinogen 4-nitroquinoline 1-oxide, dietary ZD elicited tongue/esophagus/forestomach carcinomas that were prevented by ZS. The precancerous ZD:Cox-2^−/−vs. ZS:Cox-2^−/− forestomach had an inflammatory signature with upregulation of the proinflammation genes S100a8 and S100a9. Bioinformatics analysis revealed overrepresentation of inflammation processes comprising S100a8/a9 and an nuclear factor (NF)-κB network with connectivity to S100A8. Immunohistochemistry revealed co-overexpression of S100A8, its heterodimeric partner S100A9, the receptor for advanced glycation end-products (RAGE), NF-κB p65, and cyclin D1, in ZD:Cox-2^−/− forestomach/tongue preneoplasia and carcinomas, evidence for the activation of a RAGE-S100A8/A9 inflammatory pathway. Accumulation of p53 in these carcinomas indicated activation of additional inflammatory pathways. Zn-replenishment in ZD:Cox-2^−/−mice reversed the inflammation and inhibited carcinogenesis. Thus, ZD activates alternative inflammation-associated cancer pathways that fuel tumor progression and bypass the antitumor effect of Cox-2 ablation. These findings have important clinical implications, as combination cancer therapy that includes Zn may improve efficacy.

ERK-1 MAP kinase prevents TNF-induced apoptosis through bad phosphorylation and inhibition of Bax translocation in HeLa Cells

Extracellular signal-regulated kinase (ERK) 1/2 signaling is involved in tumor cell survival through the regulation of Bcl-2 family members. To explore this further and to demonstrate the central role of the mitochondria in the ERK1/2 pathway we used the HeLa cellular model where apoptosis was induced by tumor necrosis factor (TNF) and cycloheximide (CHX). We show that HeLa cells overexpressing ERK-1 displayed resistance to TNF and CHX. HeLa cells overexpressing a kinase-deficient form of ERK-1 (K71R) were more sensitive to TNF and CHX. In the ERK-1 cells, Bad was phosphorylated during TNF + CHX treatment. In the HeLa wt cells and in the K71R clones TNF and CHX decreased Bad phosphorylation. ERK-1 cells treated with TNF and CHX did not release cytochrome c from the mitochondria. By contrast, HeLa wt and K71R clones released cytochrome c. Bax did not translocate to the mitochondria in ERK-1 cells treated with TNF + CHX. Conversely, HeLa wt and K71R clones accumulated Bax in the mitochondria. In the HeLa wt cells and in both ERK-1 transfectants Bid was cleaved and accumulated in the mitochondria. The caspase-8 inhibitor IETD-FMK and the mitochondrial membrane permeabilization inhibitor bongkrekic acid (BK), partially prevented cell death by TNF + CHX. Anisomycin, a c-Jun N-terminal kinases activator, increased TNF-killing. The ERK-1 cells were resistant to TNF and anisomycin, whereas K71R clones resulted more sensitive. Our study demonstrates that in HeLa cells the ERK-1 kinase prevents TNF + CHX apoptosis by regulating the intrinsic mitochondrial pathway through different mechanisms. Inhibition of the intrinsic pathway is sufficient to almost completely prevent cell death.

Abstract 4174: Cxcl5 and Cxcl2 overexpression in esophageal carcinogenesis is associated with rapid tumor formation in zinc-deficient rats

Objectives: Zinc-deficiency (ZD) is implicated in the pathogenesis of human esophageal cancer. It induces cell proliferation, modulates genetic expression, and enhances carcinogenesis. Zinc-replenishment (ZR) reverses proliferation and inhibits carcinogenesis. Recently, we showed that a ZD diet induces overexpression of the proinflammation mediators S100a8/a9 in hyperplastic rat esophagus, providing evidence that zinc regulates an inflammatory pathway in early esophageal carcinogenesis (Gastroenterology, 136: 953-966, 2009). Here we determined the biological processes affected by zinc nutrition during rapid N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumor development and its prevention. Methods: We evaluated gene expression profiles of esophageal mucosa from zinc-modulated rats at 5 weeks after an NMBA dose and at 15 weeks (endpoint) with 3 NMBA doses, using Affymetrix Rat Genome GeneChip. Here, ZD rats documented a significantly higher tumorigenic outcome than control zinc-sufficient (ZS) rats (tumor incidence, 100% vs 16.6%; multiplicity, 11 ± 3.8 vs 0.5 ± 0.3, P&lt;0.001). Replenishing zinc after the first NMBA dose led to a low tumorigenic outcome in ZR vs ZD rats (incidence, 28.9% vs 100%; multiplicity, 0.6 ± 0.4 vs 11 ± 3.8, P&lt;0.001). Results: The ZD esophagi have a distinct expression signature versus ZS esophagi at both time points. At 5 weeks, in addition to S100a8/a9 overexpression (up 2.5-fold), the dysplastic ZD esophagi showed up-regulation of several cancer-related inflammation genes, including CXC chemokines Cxcl5 and Cxcl2 (up &gt;25-fold); Ptgs2 (up 26-fold); and Il17f (up 2.7 fold). At endpoint, the tumor-bearing ZD esophagus displayed a neoplastic gene signature, with increased up-regulation of Cxcl5 and Cxcl2 (up 84- and 38-fold), Cxcl3 (up 9-fold), Cxcl1 (up 7-fold), Ptgs2 (up 41-fold), Il1b (up 12-fold), Il17f (up 7.5-fold), and S100a8/a9 (up 2.1-fold). Replenishing zinc led to a global reversal of abnormal gene expression, resulting in an expression profile similar to that of ZS esophagi. In parallel to mRNA expression, CXCL5, CXCL2, COX-2, and S100A8/A9 protein expression was similarly modulated by ZD and ZR, as shown by ELISA, immunoblotting, and immunohistochemistry assays. Ingenuity Pathway Analysis predicted an Il1b-centric network, with direct connections to many up-regulated genes. Conclusions: ZD fuels inflammation and drives carcinogenesis by inducing overexpression of several cancer-related inflammation genes, including Cxcl5 and Cxcl2. ZR modulates inflammatory responses and inhibits tumor growth. The data provide a new understanding of the molecular role of zinc in esophageal carcinogenesis/prevention and suggest that zinc supplementation should be more thoroughly explored in human prevention clinical trials for upper aerodigestive tract cancer. Supported by NIH grant CA118560.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4174.

Foxp3-expressing T regulatory cells and mast cells in acute graft-versus-host disease of the skin

Acute graft-versus-host disease (aGVHD) limits the effectiveness of allogeneic hematopoietic stem cell transplantation. Foxp3 is required for the development and function of CD4(+)/CD25(+) regulatory T cells (T-regs). Foxp3-expressing T-regs are thought to protect against GVHD. Mast cells are thought to be essential in CD4(+)/CD25(+) regulatory T cell-dependent peripheral tolerance. Twenty biopsies of skin with grades I-III aGVHD were stained for Foxp3 and CD117. Inflammation was quantified by a 4 point scale, 0 = no inflammation, 1 = <25% of 20x field, 2 = 25-50%, and 3 = >50%. T-regs and mast cells were quantified by a 4 point scale, 0 = no cells per 20x field, 1 = <5 cells per 20x field, 2 = 5-10 cells, and 3 = >10 cells. T-regs were positively correlated with both inflammation and aGVHD grade. Twelve cases with low T-regs had mild inflammation and lower grades of aGVHD and 6 cases with high T-regs had dense inflammatory infiltrate and higher grades of aGVHD. The number of T-regs, mast cells and density of the inflammatory infiltrate were positively correlated only in cases with mild inflammation. In aGVHD of the skin, T-regs increased with the degree of inflammation and GVHD grade. Mast cells were present at the same density whether aGVHD was of lower or higher grade.

Zinc replenishment reverses overexpression of the proinflammatory mediator S100A8 and esophageal preneoplasia in the rat

BACKGROUND & AIMS

Zinc deficiency is implicated in the pathogenesis of human esophageal cancer. In the rat esophagus, it induces cell proliferation, modulates genetic expression, and enhances carcinogenesis. Zinc-replenishment reverses proliferation and inhibits carcinogenesis. The zinc-deficient rat model allows the identification of biological differences affected by zinc during early esophageal carcinogenesis.

METHODS

We evaluated gene expression profiles of esophageal epithelia from zinc-deficient and replenished rats vs zinc-sufficient rats using microarray analysis. We characterized the role of the top-up-regulated gene S100A8 in esophageal hyperplasia/reversal and in chemically induced esophageal carcinogenesis in zinc-modulated animals by immunohistochemistry and real-time quantitative polymerase chain reaction.

RESULTS

The hyperplastic-deficient esophagus has a distinct expression signature with the proinflammation genes S100 calcium binding protein A8 (S100A8) and A9 (S100A9) up-regulated 57-fold and 5-fold, respectively. Zinc replenishment rapidly restored to control levels the expression of S100A8/A9 and 27 other genes and reversed the hyperplastic phenotype. With its receptor for advanced glycation end products (RAGE), colocalization and overexpression of S100A8 protein occurred in the deficient esophagus that overexpressed nuclear factor kappaBeta p65 and cyclooxygenase-2 (COX-2) protein. Zinc replenishment, but not a COX-2 inhibitor, reduced the overexpression of these 4 proteins. Additionally, esophageal S100A8/A9 messenger RNA levels were associated directly with the diverse tumorigenic outcome in zinc-deficient and zinc-replenished rats.

CONCLUSIONS

In vivo zinc regulates S100A8 expression and modulates the link between S100A8-RAGE interaction and downstream nuclear factor kappaBeta/COX-2 signaling. The finding that zinc regulates an inflammatory pathway in esophageal carcinogenesis may lead to prevention and therapy for this cancer.

Detailing the role of Bax translocation, cytochrome c release, and perinuclear clustering of the mitochondria in the killing of HeLa cells by TNF

Induction of cell death in HeLa cells with TNF and cycloheximide (CHX) required an adequate ATP supply and was accompanied by decrease in intracellular pH, translocation of Bax, perinuclear clustering of the mitochondria, and cytochrome c release. The chloride channel inhibitor furosemide prevented the intracellular acidification, the translocation of Bax and the cell death. Cyclosporin A (CyA) or bongkrekic acid (BK) inhibited the induction of the MPT, the release of cytochrome c and the cell death without affecting the perinuclear clustering of the mitochondria or the translocation of Bax. Energy depletion with the ATP synthase inhibitor oligomycin or the uncoupler FCCP in the presence of 2-deoxy-glucose prevented the perinuclear clustering of the mitochondria and the cell killing. However, mitochondrial translocation of Bax was still observed. By contrast, cytochrome c was released in the oligomycin-treated cells but not in the same cells treated with FCCP. The data demonstrate that apoptosis in HeLa cells is ATP dependent and requires the translocation of Bax. The movement of Bax to the mitochondria occurs before and during the perinuclear clustering of these organelles and does not require the presence of ATP. The release of cytochrome c depends on the induction of the mitochondrial permeability transition but not ATP content.

Prevention of upper aerodigestive tract cancer in zinc-deficient rodents: inefficacy of genetic or pharmacological disruption of COX-2

Zinc deficiency in humans is associated with an increased risk of upper aerodigestive tract (UADT) cancer. In rodents, zinc deficiency predisposes to carcinogenesis by causing proliferation and alterations in gene expression. We examined whether in zinc-deficient rodents, targeted disruption of the cyclooxygenase (COX)-2 pathway by the COX-2 selective inhibitor celecoxib or by genetic deletion prevent UADT carcinogenesis. Tongue cancer prevention studies were conducted in zinc-deficient rats previously exposed to a tongue carcinogen by celecoxib treatment with or without zinc replenishment, or by zinc replenishment alone. The ability of genetic COX-2 deletion to protect against chemically-induced forestomach tumorigenesis was examined in mice on zinc-deficient versus zinc-sufficient diet. The expression of 3 predictive biomarkers COX-2, nuclear factor (NF)-kappa B p65 and leukotriene A(4) hydrolase (LTA(4)H) was examined by immunohistochemistry. In zinc-deficient rats, celecoxib without zinc replenishment reduced lingual tumor multiplicity but not progression to malignancy. Celecoxib with zinc replenishment or zinc replenishment alone significantly lowered lingual squamous cell carcinoma incidence, as well as tumor multiplicity. Celecoxib alone reduced overexpression of the 3 biomarkers in tumors slightly, compared with intervention with zinc replenishment. Instead of being protected, zinc-deficient COX-2 null mice developed significantly greater tumor multiplicity and forestomach carcinoma incidence than wild-type controls. Additionally, zinc-deficient COX-2-/- forestomachs displayed strong LTA(4)H immunostaining, indicating activation of an alternative pathway under zinc deficiency when the COX-2 pathway is blocked. Thus, targeting only the COX-2 pathway in zinc-deficient animals did not prevent UADT carcinogenesis. Our data suggest zinc supplementation should be more thoroughly explored in human prevention clinical trials for UADT cancer.

c-Kit-positive mast cells in portal tracts cannot be used to distinguish acute cellular rejection from recurrent hepatitis C infection in liver allografts

Cirrhosis secondary to chronic hepatitis C virus (HCV) is the most common indication for liver transplantation. Recurrence of HCV infection in the liver allograft occurs at a high rate. The differentiation of recurrent HCV infection from acute cellular rejection (ACR) represents a difficult challenge in transplantation pathology. The c-Kit receptor is a tyrosine kinase membrane protein encoded by the c-Kit proto-oncogene, which is expressed on mast cells and on hematopoietic stem and progenitor cells. Mast cells are important effector cells of a broad range of immune responses. Recently, c-Kit+ mast cells were shown to form part of the inflammatory infiltrate in acute liver allograft rejection. A strong relationship was found between c-Kit+ cell densities and increasingly severe rejection. The present study sought to determine whether the presence of c-Kit+ cells could be used to distinguish between ACR and recurrent HCV in liver allografts. Immunohistochemical staining for c-Kit was performed on 20 transplant biopsy specimens from 10 patients with mild to moderate ACR and 10 other patients with recurrent hepatitis C. The number of c-Kit+ cells per portal tract varied with the density of the overall inflammatory infiltrate. There was no significant difference between the number of c-Kit+ cells in the biopsy specimens that carried a diagnosis of ACR and those from patients who had been diagnosed as having recurrent HCV. It was concluded that immunohistochemical staining for the presence of c-Kit+ mast cells cannot be used to differentiate between ACR and recurrent HCV infection in liver allograft biopsy specimens.

Fez1/Lzts1 absence impairs Cdk1/Cdc25C interaction during mitosis and predisposes mice to cancer development

The FEZ1/LZTS1 (LZTS1) protein is frequently downregulated in human cancers of different histotypes. LZTS1 is expressed in normal tissues, and its introduction in cancer cells inhibits cell growth and suppresses tumorigenicity, owing to an accumulation of cells in G2/M. Here, we define its role in cell cycle regulation and tumor progression by generating Lzts1 knockout mice. In Lzts1(-/-) mouse embryo fibroblasts (MEFs), Cdc25C degradation was increased during M phase, resulting in decreased Cdk1 activity. As a consequence, Lzts1(-/-) MEFs showed accelerated mitotic progression, resistance to taxol- and nocodazole-induced M phase arrest, and improper chromosome segregation. Accordingly, Lzts1 deficiency was associated with an increased incidence of both spontaneous and carcinogen-induced cancers in mice.

The Presence of B-Cell Nodules Does Not Necessarily Portend a Less Favorable Outcome to Therapy in Patients With Acute Cellular Rejection of a Renal Allograft

The presence of B-cell nodules in kidney biopsies of patients undergoing acute renal allograft rejection has been reported to be associated with glucocorticoid resistance and a high risk of graft failure. In an attempt to corroborate this observation, biopsies of renal transplants that evidenced Banff grade I A acute rejection were examined for the presence of B- or T-cell nodules, the detection of which was correlated with the therapeutic response. Biopsies from 14 consecutive renal transplant recipients with a diagnosis of acute cellular rejection were examined for the presence of T (CD3-positive) or B (CD20-positive) cells by immunohistochemistry. All patients were biopsied because of a rise in serum creatinine. No biopsy showed evidence of acute humoral rejection. Immunofluorescence microscopy was negative for C4d deposition in peritubular capillaries. There were no neutrophils in the peritubular or glomerular capillaries. Five patients had T-cell nodules; four had B-cell nodules; three had both T- and B-cell nodules; two had no nodules. All biopsies contained CD3-positive cells in the tubules and in the interstitium. In all but one of the patients, episodes of acute rejection were treated with steroids (one received thymoglobulin). Furthermore two patients received mycophenolate mofetil and one, sirolimus. There were no significant differences among the groups in either the initial creatinine or the creatinine after therapy. The presence of B-cell nodules in renal allograft biopsies of patients experiencing acute cellular rejection did not portend a less favorable outcome.

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.

Acute respiratory distress syndrome due to pulmonary involvement by neoplastic plasma cells in multiple myeloma

Pulmonary involvement with multiple myeloma occurs infrequently and may be difficult to distinguish from more common primary lung tumours, metastatic disease, or other pleural and parenchymal abnormalities. A patient who developed acute respiratory distress syndrome (ARDS) was subsequently found to have multiple myeloma with involvement of lung parenchyma by neoplastic plasma cells. Only one other report of ARDS in association with multiple myeloma was found, and there are no previous reports where the appearance of ARDS antedated a diagnosis of multiple myeloma. In patients with ARDS, parenchymal involvement from multiple myeloma should be included in the differential diagnosis.

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.

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.

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.

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.

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.

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.